1 /*
2 * Copyright (c) 2012-2024 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29 #include <string.h>
30 #include <sys/types.h>
31 #include <sys/syslog.h>
32 #include <sys/queue.h>
33 #include <sys/malloc.h>
34 #include <sys/socket.h>
35 #include <sys/kpi_mbuf.h>
36 #include <sys/mbuf.h>
37 #include <sys/domain.h>
38 #include <sys/protosw.h>
39 #include <sys/socketvar.h>
40 #include <sys/kernel.h>
41 #include <sys/systm.h>
42 #include <sys/kern_control.h>
43 #include <sys/ubc.h>
44 #include <sys/codesign.h>
45 #include <sys/file_internal.h>
46 #include <sys/kauth.h>
47 #include <libkern/tree.h>
48 #include <kern/locks.h>
49 #include <kern/debug.h>
50 #include <kern/task.h>
51 #include <mach/task_info.h>
52 #include <net/if_var.h>
53 #include <net/route.h>
54 #include <net/flowhash.h>
55 #include <net/ntstat.h>
56 #include <net/content_filter.h>
57 #include <net/necp.h>
58 #include <netinet/in.h>
59 #include <netinet/in_var.h>
60 #include <netinet/tcp.h>
61 #include <netinet/tcp_var.h>
62 #include <netinet/tcp_fsm.h>
63 #include <netinet/flow_divert.h>
64 #include <netinet/flow_divert_proto.h>
65 #include <netinet6/in6_pcb.h>
66 #include <netinet6/ip6protosw.h>
67 #include <dev/random/randomdev.h>
68 #include <libkern/crypto/sha1.h>
69 #include <libkern/crypto/crypto_internal.h>
70 #include <os/log.h>
71 #include <corecrypto/cc.h>
72 #if CONTENT_FILTER
73 #include <net/content_filter.h>
74 #endif /* CONTENT_FILTER */
75
76 #define FLOW_DIVERT_CONNECT_STARTED 0x00000001
77 #define FLOW_DIVERT_READ_CLOSED 0x00000002
78 #define FLOW_DIVERT_WRITE_CLOSED 0x00000004
79 #define FLOW_DIVERT_TUNNEL_RD_CLOSED 0x00000008
80 #define FLOW_DIVERT_TUNNEL_WR_CLOSED 0x00000010
81 #define FLOW_DIVERT_HAS_HMAC 0x00000040
82 #define FLOW_DIVERT_NOTIFY_ON_RECEIVED 0x00000080
83 #define FLOW_DIVERT_IMPLICIT_CONNECT 0x00000100
84 #define FLOW_DIVERT_DID_SET_LOCAL_ADDR 0x00000200
85 #define FLOW_DIVERT_HAS_TOKEN 0x00000400
86 #define FLOW_DIVERT_SHOULD_SET_LOCAL_ADDR 0x00000800
87 #define FLOW_DIVERT_FLOW_IS_TRANSPARENT 0x00001000
88
89 #define FDLOG(level, pcb, format, ...) \
90 os_log_with_type(OS_LOG_DEFAULT, flow_divert_syslog_type_to_oslog_type(level), "(%u): " format "\n", (pcb)->hash, __VA_ARGS__)
91
92 #define FDLOG0(level, pcb, msg) \
93 os_log_with_type(OS_LOG_DEFAULT, flow_divert_syslog_type_to_oslog_type(level), "(%u): " msg "\n", (pcb)->hash)
94
95 #define FDRETAIN(pcb) if ((pcb) != NULL) OSIncrementAtomic(&(pcb)->ref_count)
96 #define FDRELEASE(pcb) \
97 do { \
98 if ((pcb) != NULL && 1 == OSDecrementAtomic(&(pcb)->ref_count)) { \
99 flow_divert_pcb_destroy(pcb); \
100 } \
101 } while (0)
102
103 #define FDGRP_RETAIN(grp) if ((grp) != NULL) OSIncrementAtomic(&(grp)->ref_count)
104 #define FDGRP_RELEASE(grp) if ((grp) != NULL && 1 == OSDecrementAtomic(&(grp)->ref_count)) flow_divert_group_destroy(grp)
105
106 #define FDLOCK(pcb) lck_mtx_lock(&(pcb)->mtx)
107 #define FDUNLOCK(pcb) lck_mtx_unlock(&(pcb)->mtx)
108
109 #define FD_CTL_SENDBUFF_SIZE (128 * 1024)
110
111 #define GROUP_BIT_CTL_ENQUEUE_BLOCKED 0
112
113 #define GROUP_COUNT_MAX 31
114 #define FLOW_DIVERT_MAX_NAME_SIZE 4096
115 #define FLOW_DIVERT_MAX_KEY_SIZE 1024
116 #define FLOW_DIVERT_MAX_TRIE_MEMORY (1024 * 1024)
117
118 struct flow_divert_trie_node {
119 uint16_t start;
120 uint16_t length;
121 uint16_t child_map;
122 };
123
124 #define CHILD_MAP_SIZE 256
125 #define NULL_TRIE_IDX 0xffff
126 #define TRIE_NODE(t, i) ((t)->nodes[(i)])
127 #define TRIE_CHILD(t, i, b) (((t)->child_maps + (CHILD_MAP_SIZE * TRIE_NODE(t, i).child_map))[(b)])
128 #define TRIE_BYTE(t, i) ((t)->bytes[(i)])
129
130 #define SO_IS_DIVERTED(s) (((s)->so_flags & SOF_FLOW_DIVERT) && (s)->so_fd_pcb != NULL)
131
132 static struct flow_divert_pcb nil_pcb;
133
134 static LCK_ATTR_DECLARE(flow_divert_mtx_attr, 0, 0);
135 static LCK_GRP_DECLARE(flow_divert_mtx_grp, FLOW_DIVERT_CONTROL_NAME);
136 static LCK_RW_DECLARE_ATTR(g_flow_divert_group_lck, &flow_divert_mtx_grp,
137 &flow_divert_mtx_attr);
138
139 static TAILQ_HEAD(_flow_divert_group_list, flow_divert_group) g_flow_divert_in_process_group_list;
140
141 static struct flow_divert_group **g_flow_divert_groups = NULL;
142 static uint32_t g_active_group_count = 0;
143
144 static errno_t g_init_result = 0;
145
146 static kern_ctl_ref g_flow_divert_kctl_ref = NULL;
147
148 static struct protosw g_flow_divert_in_protosw;
149 static struct pr_usrreqs g_flow_divert_in_usrreqs;
150 static struct protosw g_flow_divert_in_udp_protosw;
151 static struct pr_usrreqs g_flow_divert_in_udp_usrreqs;
152 static struct ip6protosw g_flow_divert_in6_protosw;
153 static struct pr_usrreqs g_flow_divert_in6_usrreqs;
154 static struct ip6protosw g_flow_divert_in6_udp_protosw;
155 static struct pr_usrreqs g_flow_divert_in6_udp_usrreqs;
156
157 static struct protosw *g_tcp_protosw = NULL;
158 static struct ip6protosw *g_tcp6_protosw = NULL;
159 static struct protosw *g_udp_protosw = NULL;
160 static struct ip6protosw *g_udp6_protosw = NULL;
161
162 static KALLOC_TYPE_DEFINE(flow_divert_group_zone, struct flow_divert_group,
163 NET_KT_DEFAULT);
164 static KALLOC_TYPE_DEFINE(flow_divert_pcb_zone, struct flow_divert_pcb,
165 NET_KT_DEFAULT);
166
167 static errno_t
168 flow_divert_dup_addr(sa_family_t family, struct sockaddr *addr, struct sockaddr **dup);
169
170 static boolean_t
171 flow_divert_is_sockaddr_valid(struct sockaddr *addr);
172
173 static int
174 flow_divert_append_target_endpoint_tlv(mbuf_t connect_packet, struct sockaddr *toaddr);
175
176 struct sockaddr *
177 flow_divert_get_buffered_target_address(mbuf_t buffer);
178
179 static void
180 flow_divert_disconnect_socket(struct socket *so, bool is_connected, bool delay_if_needed);
181
182 static void flow_divert_group_destroy(struct flow_divert_group *group);
183
184 static inline uint8_t
flow_divert_syslog_type_to_oslog_type(int syslog_type)185 flow_divert_syslog_type_to_oslog_type(int syslog_type)
186 {
187 switch (syslog_type) {
188 case LOG_ERR: return OS_LOG_TYPE_ERROR;
189 case LOG_INFO: return OS_LOG_TYPE_INFO;
190 case LOG_DEBUG: return OS_LOG_TYPE_DEBUG;
191 default: return OS_LOG_TYPE_DEFAULT;
192 }
193 }
194
195 static inline int
flow_divert_pcb_cmp(const struct flow_divert_pcb * pcb_a,const struct flow_divert_pcb * pcb_b)196 flow_divert_pcb_cmp(const struct flow_divert_pcb *pcb_a, const struct flow_divert_pcb *pcb_b)
197 {
198 return memcmp(&pcb_a->hash, &pcb_b->hash, sizeof(pcb_a->hash));
199 }
200
201 RB_PROTOTYPE(fd_pcb_tree, flow_divert_pcb, rb_link, flow_divert_pcb_cmp);
202 RB_GENERATE(fd_pcb_tree, flow_divert_pcb, rb_link, flow_divert_pcb_cmp);
203
204 static const char *
flow_divert_packet_type2str(uint8_t packet_type)205 flow_divert_packet_type2str(uint8_t packet_type)
206 {
207 switch (packet_type) {
208 case FLOW_DIVERT_PKT_CONNECT:
209 return "connect";
210 case FLOW_DIVERT_PKT_CONNECT_RESULT:
211 return "connect result";
212 case FLOW_DIVERT_PKT_DATA:
213 return "data";
214 case FLOW_DIVERT_PKT_CLOSE:
215 return "close";
216 case FLOW_DIVERT_PKT_READ_NOTIFY:
217 return "read notification";
218 case FLOW_DIVERT_PKT_PROPERTIES_UPDATE:
219 return "properties update";
220 case FLOW_DIVERT_PKT_APP_MAP_CREATE:
221 return "app map create";
222 default:
223 return "unknown";
224 }
225 }
226
227 static struct flow_divert_pcb *
flow_divert_pcb_lookup(uint32_t hash,struct flow_divert_group * group)228 flow_divert_pcb_lookup(uint32_t hash, struct flow_divert_group *group)
229 {
230 struct flow_divert_pcb key_item;
231 struct flow_divert_pcb *fd_cb = NULL;
232
233 key_item.hash = hash;
234
235 lck_rw_lock_shared(&group->lck);
236 fd_cb = RB_FIND(fd_pcb_tree, &group->pcb_tree, &key_item);
237 FDRETAIN(fd_cb);
238 lck_rw_done(&group->lck);
239
240 return fd_cb;
241 }
242
243 static struct flow_divert_group *
flow_divert_group_lookup(uint32_t ctl_unit,struct flow_divert_pcb * fd_cb)244 flow_divert_group_lookup(uint32_t ctl_unit, struct flow_divert_pcb *fd_cb)
245 {
246 struct flow_divert_group *group = NULL;
247 lck_rw_lock_shared(&g_flow_divert_group_lck);
248 if (g_active_group_count == 0) {
249 if (fd_cb != NULL) {
250 FDLOG0(LOG_ERR, fd_cb, "No active groups, flow divert cannot be used for this socket");
251 }
252 } else if (ctl_unit == 0 || (ctl_unit >= GROUP_COUNT_MAX && ctl_unit < FLOW_DIVERT_IN_PROCESS_UNIT_MIN)) {
253 FDLOG(LOG_ERR, fd_cb, "Cannot lookup group with invalid control unit (%u)", ctl_unit);
254 } else if (ctl_unit < FLOW_DIVERT_IN_PROCESS_UNIT_MIN) {
255 if (g_flow_divert_groups == NULL) {
256 if (fd_cb != NULL) {
257 FDLOG0(LOG_ERR, fd_cb, "No active non-in-process groups, flow divert cannot be used for this socket");
258 }
259 } else {
260 group = g_flow_divert_groups[ctl_unit];
261 if (group == NULL) {
262 if (fd_cb != NULL) {
263 FDLOG(LOG_ERR, fd_cb, "Group for control unit %u is NULL, flow divert cannot be used for this socket", ctl_unit);
264 }
265 } else {
266 FDGRP_RETAIN(group);
267 }
268 }
269 } else {
270 if (TAILQ_EMPTY(&g_flow_divert_in_process_group_list)) {
271 if (fd_cb != NULL) {
272 FDLOG0(LOG_ERR, fd_cb, "No active in-process groups, flow divert cannot be used for this socket");
273 }
274 } else {
275 struct flow_divert_group *group_cursor = NULL;
276 TAILQ_FOREACH(group_cursor, &g_flow_divert_in_process_group_list, chain) {
277 if (group_cursor->ctl_unit == ctl_unit) {
278 group = group_cursor;
279 break;
280 }
281 }
282 if (group == NULL) {
283 if (fd_cb != NULL) {
284 FDLOG(LOG_ERR, fd_cb, "Group for control unit %u not found, flow divert cannot be used for this socket", ctl_unit);
285 }
286 } else if (fd_cb != NULL &&
287 (fd_cb->so == NULL ||
288 group_cursor->in_process_pid != fd_cb->so->last_pid)) {
289 FDLOG(LOG_ERR, fd_cb, "Cannot access group for control unit %u, mismatched PID (%u != %u)",
290 ctl_unit, group_cursor->in_process_pid, fd_cb->so ? fd_cb->so->last_pid : 0);
291 group = NULL;
292 } else {
293 FDGRP_RETAIN(group);
294 }
295 }
296 }
297 lck_rw_done(&g_flow_divert_group_lck);
298 return group;
299 }
300
301 static errno_t
flow_divert_pcb_insert(struct flow_divert_pcb * fd_cb,struct flow_divert_group * group)302 flow_divert_pcb_insert(struct flow_divert_pcb *fd_cb, struct flow_divert_group *group)
303 {
304 int error = 0;
305 lck_rw_lock_exclusive(&group->lck);
306 if (!(group->flags & FLOW_DIVERT_GROUP_FLAG_DEFUNCT)) {
307 if (NULL == RB_INSERT(fd_pcb_tree, &group->pcb_tree, fd_cb)) {
308 fd_cb->group = group;
309 fd_cb->control_group_unit = group->ctl_unit;
310 FDRETAIN(fd_cb); /* The group now has a reference */
311 } else {
312 FDLOG(LOG_ERR, fd_cb, "Group %u already contains a PCB with hash %u", group->ctl_unit, fd_cb->hash);
313 error = EEXIST;
314 }
315 } else {
316 FDLOG(LOG_ERR, fd_cb, "Group %u is defunct, cannot insert", group->ctl_unit);
317 error = ENOENT;
318 }
319 lck_rw_done(&group->lck);
320 return error;
321 }
322
323 static errno_t
flow_divert_add_to_group(struct flow_divert_pcb * fd_cb,uint32_t ctl_unit)324 flow_divert_add_to_group(struct flow_divert_pcb *fd_cb, uint32_t ctl_unit)
325 {
326 errno_t error = 0;
327 struct flow_divert_group *group = NULL;
328 static uint32_t g_nextkey = 1;
329 static uint32_t g_hash_seed = 0;
330 int try_count = 0;
331
332 group = flow_divert_group_lookup(ctl_unit, fd_cb);
333 if (group == NULL) {
334 return ENOENT;
335 }
336
337 do {
338 uint32_t key[2];
339 uint32_t idx;
340
341 key[0] = g_nextkey++;
342 key[1] = RandomULong();
343
344 if (g_hash_seed == 0) {
345 g_hash_seed = RandomULong();
346 }
347
348 error = 0;
349 fd_cb->hash = net_flowhash(key, sizeof(key), g_hash_seed);
350
351 for (idx = 1; idx < GROUP_COUNT_MAX && error == 0; idx++) {
352 if (idx == ctl_unit) {
353 continue;
354 }
355 struct flow_divert_group *curr_group = flow_divert_group_lookup(idx, NULL);
356 if (curr_group != NULL) {
357 lck_rw_lock_shared(&curr_group->lck);
358 if (NULL != RB_FIND(fd_pcb_tree, &curr_group->pcb_tree, fd_cb)) {
359 error = EEXIST;
360 }
361 lck_rw_done(&curr_group->lck);
362 FDGRP_RELEASE(curr_group);
363 }
364 }
365
366 if (error == 0) {
367 error = flow_divert_pcb_insert(fd_cb, group);
368 }
369 } while (error == EEXIST && try_count++ < 3);
370
371 if (error == EEXIST) {
372 FDLOG0(LOG_ERR, fd_cb, "Failed to create a unique hash");
373 fd_cb->hash = 0;
374 }
375
376 FDGRP_RELEASE(group);
377 return error;
378 }
379
380 static struct flow_divert_pcb *
flow_divert_pcb_create(socket_t so)381 flow_divert_pcb_create(socket_t so)
382 {
383 struct flow_divert_pcb *new_pcb = NULL;
384
385 new_pcb = zalloc_flags(flow_divert_pcb_zone, Z_WAITOK | Z_ZERO);
386 lck_mtx_init(&new_pcb->mtx, &flow_divert_mtx_grp, &flow_divert_mtx_attr);
387 new_pcb->so = so;
388 new_pcb->log_level = nil_pcb.log_level;
389
390 FDRETAIN(new_pcb); /* Represents the socket's reference */
391
392 return new_pcb;
393 }
394
395 static void
flow_divert_pcb_destroy(struct flow_divert_pcb * fd_cb)396 flow_divert_pcb_destroy(struct flow_divert_pcb *fd_cb)
397 {
398 FDLOG(LOG_INFO, fd_cb, "Destroying, app tx %llu, tunnel tx %llu, tunnel rx %llu",
399 fd_cb->bytes_written_by_app, fd_cb->bytes_sent, fd_cb->bytes_received);
400
401 if (fd_cb->connect_token != NULL) {
402 mbuf_freem(fd_cb->connect_token);
403 }
404 if (fd_cb->connect_packet != NULL) {
405 mbuf_freem(fd_cb->connect_packet);
406 }
407 if (fd_cb->app_data != NULL) {
408 kfree_data(fd_cb->app_data, fd_cb->app_data_length);
409 }
410 if (fd_cb->original_remote_endpoint != NULL) {
411 free_sockaddr(fd_cb->original_remote_endpoint);
412 }
413 zfree(flow_divert_pcb_zone, fd_cb);
414 }
415
416 static void
flow_divert_pcb_remove(struct flow_divert_pcb * fd_cb)417 flow_divert_pcb_remove(struct flow_divert_pcb *fd_cb)
418 {
419 if (fd_cb->group != NULL) {
420 struct flow_divert_group *group = fd_cb->group;
421 lck_rw_lock_exclusive(&group->lck);
422 FDLOG(LOG_INFO, fd_cb, "Removing from group %d, ref count = %d", group->ctl_unit, fd_cb->ref_count);
423 RB_REMOVE(fd_pcb_tree, &group->pcb_tree, fd_cb);
424 fd_cb->group = NULL;
425 FDRELEASE(fd_cb); /* Release the group's reference */
426 lck_rw_done(&group->lck);
427 }
428 }
429
430 static int
flow_divert_packet_init(struct flow_divert_pcb * fd_cb,uint8_t packet_type,mbuf_t * packet)431 flow_divert_packet_init(struct flow_divert_pcb *fd_cb, uint8_t packet_type, mbuf_t *packet)
432 {
433 struct flow_divert_packet_header hdr;
434 int error = 0;
435
436 error = mbuf_gethdr(MBUF_DONTWAIT, MBUF_TYPE_HEADER, packet);
437 if (error) {
438 FDLOG(LOG_ERR, fd_cb, "failed to allocate the header mbuf: %d", error);
439 return error;
440 }
441
442 hdr.packet_type = packet_type;
443 hdr.conn_id = htonl(fd_cb->hash);
444
445 /* Lay down the header */
446 error = mbuf_copyback(*packet, 0, sizeof(hdr), &hdr, MBUF_DONTWAIT);
447 if (error) {
448 FDLOG(LOG_ERR, fd_cb, "mbuf_copyback(hdr) failed: %d", error);
449 mbuf_freem(*packet);
450 *packet = NULL;
451 return error;
452 }
453
454 return 0;
455 }
456
457 static int
flow_divert_packet_append_tlv(mbuf_t packet,uint8_t type,uint32_t length,const void * value)458 flow_divert_packet_append_tlv(mbuf_t packet, uint8_t type, uint32_t length, const void *value)
459 {
460 uint32_t net_length = htonl(length);
461 int error = 0;
462
463 error = mbuf_copyback(packet, mbuf_pkthdr_len(packet), sizeof(type), &type, MBUF_DONTWAIT);
464 if (error) {
465 FDLOG(LOG_ERR, &nil_pcb, "failed to append the type (%d)", type);
466 return error;
467 }
468
469 error = mbuf_copyback(packet, mbuf_pkthdr_len(packet), sizeof(net_length), &net_length, MBUF_DONTWAIT);
470 if (error) {
471 FDLOG(LOG_ERR, &nil_pcb, "failed to append the length (%u)", length);
472 return error;
473 }
474
475 error = mbuf_copyback(packet, mbuf_pkthdr_len(packet), length, value, MBUF_DONTWAIT);
476 if (error) {
477 FDLOG0(LOG_ERR, &nil_pcb, "failed to append the value");
478 return error;
479 }
480
481 return error;
482 }
483
484 static int
flow_divert_packet_find_tlv(mbuf_t packet,int offset,uint8_t type,int * err,int next)485 flow_divert_packet_find_tlv(mbuf_t packet, int offset, uint8_t type, int *err, int next)
486 {
487 size_t cursor = offset;
488 int error = 0;
489 uint32_t curr_length;
490 uint8_t curr_type;
491
492 *err = 0;
493
494 do {
495 if (!next) {
496 error = mbuf_copydata(packet, cursor, sizeof(curr_type), &curr_type);
497 if (error) {
498 *err = ENOENT;
499 return -1;
500 }
501 } else {
502 next = 0;
503 curr_type = FLOW_DIVERT_TLV_NIL;
504 }
505
506 if (curr_type != type) {
507 cursor += sizeof(curr_type);
508 error = mbuf_copydata(packet, cursor, sizeof(curr_length), &curr_length);
509 if (error) {
510 *err = error;
511 return -1;
512 }
513
514 cursor += (sizeof(curr_length) + ntohl(curr_length));
515 }
516 } while (curr_type != type);
517
518 return (int)cursor;
519 }
520
521 static int
flow_divert_packet_get_tlv(mbuf_t packet,int offset,uint8_t type,size_t buff_len,void * buff,uint32_t * val_size)522 flow_divert_packet_get_tlv(mbuf_t packet, int offset, uint8_t type, size_t buff_len, void *buff, uint32_t *val_size)
523 {
524 int error = 0;
525 uint32_t length;
526 int tlv_offset;
527
528 tlv_offset = flow_divert_packet_find_tlv(packet, offset, type, &error, 0);
529 if (tlv_offset < 0) {
530 return error;
531 }
532
533 error = mbuf_copydata(packet, tlv_offset + sizeof(type), sizeof(length), &length);
534 if (error) {
535 return error;
536 }
537
538 length = ntohl(length);
539
540 uint32_t data_offset = tlv_offset + sizeof(type) + sizeof(length);
541
542 if (length > (mbuf_pkthdr_len(packet) - data_offset)) {
543 FDLOG(LOG_ERR, &nil_pcb, "Length of %u TLV (%u) is larger than remaining packet data (%lu)", type, length, (mbuf_pkthdr_len(packet) - data_offset));
544 return EINVAL;
545 }
546
547 if (val_size != NULL) {
548 *val_size = length;
549 }
550
551 if (buff != NULL && buff_len > 0) {
552 memset(buff, 0, buff_len);
553 size_t to_copy = (length < buff_len) ? length : buff_len;
554 error = mbuf_copydata(packet, data_offset, to_copy, buff);
555 if (error) {
556 return error;
557 }
558 }
559
560 return 0;
561 }
562
563 static int
flow_divert_packet_compute_hmac(mbuf_t packet,struct flow_divert_group * group,uint8_t * hmac)564 flow_divert_packet_compute_hmac(mbuf_t packet, struct flow_divert_group *group, uint8_t *hmac)
565 {
566 mbuf_t curr_mbuf = packet;
567
568 if (g_crypto_funcs == NULL || group->token_key == NULL) {
569 return ENOPROTOOPT;
570 }
571
572 cchmac_di_decl(g_crypto_funcs->ccsha1_di, hmac_ctx);
573 g_crypto_funcs->cchmac_init_fn(g_crypto_funcs->ccsha1_di, hmac_ctx, group->token_key_size, group->token_key);
574
575 while (curr_mbuf != NULL) {
576 g_crypto_funcs->cchmac_update_fn(g_crypto_funcs->ccsha1_di, hmac_ctx, mbuf_len(curr_mbuf), mbuf_data(curr_mbuf));
577 curr_mbuf = mbuf_next(curr_mbuf);
578 }
579
580 g_crypto_funcs->cchmac_final_fn(g_crypto_funcs->ccsha1_di, hmac_ctx, hmac);
581
582 return 0;
583 }
584
585 static int
flow_divert_packet_verify_hmac(mbuf_t packet,uint32_t ctl_unit)586 flow_divert_packet_verify_hmac(mbuf_t packet, uint32_t ctl_unit)
587 {
588 int error = 0;
589 struct flow_divert_group *group = NULL;
590 int hmac_offset;
591 uint8_t packet_hmac[SHA_DIGEST_LENGTH];
592 uint8_t computed_hmac[SHA_DIGEST_LENGTH];
593 mbuf_t tail;
594
595 group = flow_divert_group_lookup(ctl_unit, NULL);
596 if (group == NULL) {
597 FDLOG(LOG_ERR, &nil_pcb, "Failed to lookup group for control unit %u", ctl_unit);
598 return ENOPROTOOPT;
599 }
600
601 lck_rw_lock_shared(&group->lck);
602
603 if (group->token_key == NULL) {
604 error = ENOPROTOOPT;
605 goto done;
606 }
607
608 hmac_offset = flow_divert_packet_find_tlv(packet, 0, FLOW_DIVERT_TLV_HMAC, &error, 0);
609 if (hmac_offset < 0) {
610 goto done;
611 }
612
613 error = flow_divert_packet_get_tlv(packet, hmac_offset, FLOW_DIVERT_TLV_HMAC, sizeof(packet_hmac), packet_hmac, NULL);
614 if (error) {
615 goto done;
616 }
617
618 /* Chop off the HMAC TLV */
619 error = mbuf_split(packet, hmac_offset, MBUF_WAITOK, &tail);
620 if (error) {
621 goto done;
622 }
623
624 mbuf_free(tail);
625
626 error = flow_divert_packet_compute_hmac(packet, group, computed_hmac);
627 if (error) {
628 goto done;
629 }
630
631 if (cc_cmp_safe(sizeof(packet_hmac), packet_hmac, computed_hmac)) {
632 FDLOG0(LOG_WARNING, &nil_pcb, "HMAC in token does not match computed HMAC");
633 error = EINVAL;
634 goto done;
635 }
636
637 done:
638 if (group != NULL) {
639 lck_rw_done(&group->lck);
640 FDGRP_RELEASE(group);
641 }
642 return error;
643 }
644
645 static void
flow_divert_add_data_statistics(struct flow_divert_pcb * fd_cb,size_t data_len,Boolean send)646 flow_divert_add_data_statistics(struct flow_divert_pcb *fd_cb, size_t data_len, Boolean send)
647 {
648 struct inpcb *inp = NULL;
649 struct ifnet *ifp = NULL;
650 Boolean cell = FALSE;
651 Boolean wifi = FALSE;
652 Boolean wired = FALSE;
653
654 inp = sotoinpcb(fd_cb->so);
655 if (inp == NULL) {
656 return;
657 }
658
659 if (inp->inp_vflag & INP_IPV4) {
660 ifp = inp->inp_last_outifp;
661 } else if (inp->inp_vflag & INP_IPV6) {
662 ifp = inp->in6p_last_outifp;
663 }
664 if (ifp != NULL) {
665 cell = IFNET_IS_CELLULAR(ifp);
666 wifi = (!cell && IFNET_IS_WIFI(ifp));
667 wired = (!wifi && IFNET_IS_WIRED(ifp));
668 }
669
670 if (send) {
671 INP_ADD_STAT(inp, cell, wifi, wired, txpackets, 1);
672 INP_ADD_STAT(inp, cell, wifi, wired, txbytes, data_len);
673 } else {
674 INP_ADD_STAT(inp, cell, wifi, wired, rxpackets, 1);
675 INP_ADD_STAT(inp, cell, wifi, wired, rxbytes, data_len);
676 }
677 inp_set_activity_bitmap(inp);
678 }
679
680 static errno_t
flow_divert_check_no_cellular(struct flow_divert_pcb * fd_cb)681 flow_divert_check_no_cellular(struct flow_divert_pcb *fd_cb)
682 {
683 struct inpcb *inp = sotoinpcb(fd_cb->so);
684 if (INP_NO_CELLULAR(inp)) {
685 struct ifnet *ifp = NULL;
686 if (inp->inp_vflag & INP_IPV4) {
687 ifp = inp->inp_last_outifp;
688 } else if (inp->inp_vflag & INP_IPV6) {
689 ifp = inp->in6p_last_outifp;
690 }
691 if (ifp != NULL && IFNET_IS_CELLULAR(ifp)) {
692 FDLOG0(LOG_ERR, fd_cb, "Cellular is denied");
693 return EHOSTUNREACH;
694 }
695 }
696 return 0;
697 }
698
699 static errno_t
flow_divert_check_no_expensive(struct flow_divert_pcb * fd_cb)700 flow_divert_check_no_expensive(struct flow_divert_pcb *fd_cb)
701 {
702 struct inpcb *inp = sotoinpcb(fd_cb->so);
703 if (INP_NO_EXPENSIVE(inp)) {
704 struct ifnet *ifp = NULL;
705 if (inp->inp_vflag & INP_IPV4) {
706 ifp = inp->inp_last_outifp;
707 } else if (inp->inp_vflag & INP_IPV6) {
708 ifp = inp->in6p_last_outifp;
709 }
710 if (ifp != NULL && IFNET_IS_EXPENSIVE(ifp)) {
711 FDLOG0(LOG_ERR, fd_cb, "Expensive is denied");
712 return EHOSTUNREACH;
713 }
714 }
715 return 0;
716 }
717
718 static errno_t
flow_divert_check_no_constrained(struct flow_divert_pcb * fd_cb)719 flow_divert_check_no_constrained(struct flow_divert_pcb *fd_cb)
720 {
721 struct inpcb *inp = sotoinpcb(fd_cb->so);
722 if (INP_NO_CONSTRAINED(inp)) {
723 struct ifnet *ifp = NULL;
724 if (inp->inp_vflag & INP_IPV4) {
725 ifp = inp->inp_last_outifp;
726 } else if (inp->inp_vflag & INP_IPV6) {
727 ifp = inp->in6p_last_outifp;
728 }
729 if (ifp != NULL && IFNET_IS_CONSTRAINED(ifp)) {
730 FDLOG0(LOG_ERR, fd_cb, "Constrained is denied");
731 return EHOSTUNREACH;
732 }
733 }
734 return 0;
735 }
736
737 static void
flow_divert_update_closed_state(struct flow_divert_pcb * fd_cb,int how,bool tunnel,bool flush_snd)738 flow_divert_update_closed_state(struct flow_divert_pcb *fd_cb, int how, bool tunnel, bool flush_snd)
739 {
740 if (how != SHUT_RD) {
741 fd_cb->flags |= FLOW_DIVERT_WRITE_CLOSED;
742 if (tunnel || !(fd_cb->flags & FLOW_DIVERT_CONNECT_STARTED)) {
743 fd_cb->flags |= FLOW_DIVERT_TUNNEL_WR_CLOSED;
744 if (flush_snd) {
745 /* If the tunnel is not accepting writes any more, then flush the send buffer */
746 sbflush(&fd_cb->so->so_snd);
747 }
748 }
749 }
750 if (how != SHUT_WR) {
751 fd_cb->flags |= FLOW_DIVERT_READ_CLOSED;
752 if (tunnel || !(fd_cb->flags & FLOW_DIVERT_CONNECT_STARTED)) {
753 fd_cb->flags |= FLOW_DIVERT_TUNNEL_RD_CLOSED;
754 }
755 }
756 }
757
758 static uint16_t
trie_node_alloc(struct flow_divert_trie * trie)759 trie_node_alloc(struct flow_divert_trie *trie)
760 {
761 if (trie->nodes_free_next < trie->nodes_count) {
762 uint16_t node_idx = trie->nodes_free_next++;
763 TRIE_NODE(trie, node_idx).child_map = NULL_TRIE_IDX;
764 return node_idx;
765 } else {
766 return NULL_TRIE_IDX;
767 }
768 }
769
770 static uint16_t
trie_child_map_alloc(struct flow_divert_trie * trie)771 trie_child_map_alloc(struct flow_divert_trie *trie)
772 {
773 if (trie->child_maps_free_next < trie->child_maps_count) {
774 return trie->child_maps_free_next++;
775 } else {
776 return NULL_TRIE_IDX;
777 }
778 }
779
780 static uint16_t
trie_bytes_move(struct flow_divert_trie * trie,uint16_t bytes_idx,size_t bytes_size)781 trie_bytes_move(struct flow_divert_trie *trie, uint16_t bytes_idx, size_t bytes_size)
782 {
783 uint16_t start = trie->bytes_free_next;
784 if (start + bytes_size <= trie->bytes_count) {
785 if (start != bytes_idx) {
786 memmove(&TRIE_BYTE(trie, start), &TRIE_BYTE(trie, bytes_idx), bytes_size);
787 }
788 trie->bytes_free_next += bytes_size;
789 return start;
790 } else {
791 return NULL_TRIE_IDX;
792 }
793 }
794
795 static uint16_t
flow_divert_trie_insert(struct flow_divert_trie * trie,uint16_t string_start,size_t string_len)796 flow_divert_trie_insert(struct flow_divert_trie *trie, uint16_t string_start, size_t string_len)
797 {
798 uint16_t current = trie->root;
799 uint16_t child = trie->root;
800 uint16_t string_end = string_start + (uint16_t)string_len;
801 uint16_t string_idx = string_start;
802 uint16_t string_remainder = (uint16_t)string_len;
803
804 while (child != NULL_TRIE_IDX) {
805 uint16_t parent = current;
806 uint16_t node_idx;
807 uint16_t current_end;
808
809 current = child;
810 child = NULL_TRIE_IDX;
811
812 current_end = TRIE_NODE(trie, current).start + TRIE_NODE(trie, current).length;
813
814 for (node_idx = TRIE_NODE(trie, current).start;
815 node_idx < current_end &&
816 string_idx < string_end &&
817 TRIE_BYTE(trie, node_idx) == TRIE_BYTE(trie, string_idx);
818 node_idx++, string_idx++) {
819 ;
820 }
821
822 string_remainder = string_end - string_idx;
823
824 if (node_idx < (TRIE_NODE(trie, current).start + TRIE_NODE(trie, current).length)) {
825 /*
826 * We did not reach the end of the current node's string.
827 * We need to split the current node into two:
828 * 1. A new node that contains the prefix of the node that matches
829 * the prefix of the string being inserted.
830 * 2. The current node modified to point to the remainder
831 * of the current node's string.
832 */
833 uint16_t prefix = trie_node_alloc(trie);
834 if (prefix == NULL_TRIE_IDX) {
835 FDLOG0(LOG_ERR, &nil_pcb, "Ran out of trie nodes while splitting an existing node");
836 return NULL_TRIE_IDX;
837 }
838
839 /*
840 * Prefix points to the portion of the current nodes's string that has matched
841 * the input string thus far.
842 */
843 TRIE_NODE(trie, prefix).start = TRIE_NODE(trie, current).start;
844 TRIE_NODE(trie, prefix).length = (node_idx - TRIE_NODE(trie, current).start);
845
846 /*
847 * Prefix has the current node as the child corresponding to the first byte
848 * after the split.
849 */
850 TRIE_NODE(trie, prefix).child_map = trie_child_map_alloc(trie);
851 if (TRIE_NODE(trie, prefix).child_map == NULL_TRIE_IDX) {
852 FDLOG0(LOG_ERR, &nil_pcb, "Ran out of child maps while splitting an existing node");
853 return NULL_TRIE_IDX;
854 }
855 TRIE_CHILD(trie, prefix, TRIE_BYTE(trie, node_idx)) = current;
856
857 /* Parent has the prefix as the child correspoding to the first byte in the prefix */
858 TRIE_CHILD(trie, parent, TRIE_BYTE(trie, TRIE_NODE(trie, prefix).start)) = prefix;
859
860 /* Current node is adjusted to point to the remainder */
861 TRIE_NODE(trie, current).start = node_idx;
862 TRIE_NODE(trie, current).length -= TRIE_NODE(trie, prefix).length;
863
864 /* We want to insert the new leaf (if any) as a child of the prefix */
865 current = prefix;
866 }
867
868 if (string_remainder > 0) {
869 /*
870 * We still have bytes in the string that have not been matched yet.
871 * If the current node has children, iterate to the child corresponding
872 * to the next byte in the string.
873 */
874 if (TRIE_NODE(trie, current).child_map != NULL_TRIE_IDX) {
875 child = TRIE_CHILD(trie, current, TRIE_BYTE(trie, string_idx));
876 }
877 }
878 } /* while (child != NULL_TRIE_IDX) */
879
880 if (string_remainder > 0) {
881 /* Add a new leaf containing the remainder of the string */
882 uint16_t leaf = trie_node_alloc(trie);
883 if (leaf == NULL_TRIE_IDX) {
884 FDLOG0(LOG_ERR, &nil_pcb, "Ran out of trie nodes while inserting a new leaf");
885 return NULL_TRIE_IDX;
886 }
887
888 TRIE_NODE(trie, leaf).start = trie_bytes_move(trie, string_idx, string_remainder);
889 if (TRIE_NODE(trie, leaf).start == NULL_TRIE_IDX) {
890 FDLOG0(LOG_ERR, &nil_pcb, "Ran out of bytes while inserting a new leaf");
891 return NULL_TRIE_IDX;
892 }
893 TRIE_NODE(trie, leaf).length = string_remainder;
894
895 /* Set the new leaf as the child of the current node */
896 if (TRIE_NODE(trie, current).child_map == NULL_TRIE_IDX) {
897 TRIE_NODE(trie, current).child_map = trie_child_map_alloc(trie);
898 if (TRIE_NODE(trie, current).child_map == NULL_TRIE_IDX) {
899 FDLOG0(LOG_ERR, &nil_pcb, "Ran out of child maps while inserting a new leaf");
900 return NULL_TRIE_IDX;
901 }
902 }
903 TRIE_CHILD(trie, current, TRIE_BYTE(trie, TRIE_NODE(trie, leaf).start)) = leaf;
904 current = leaf;
905 } /* else duplicate or this string is a prefix of one of the existing strings */
906
907 return current;
908 }
909
910 #define APPLE_WEBCLIP_ID_PREFIX "com.apple.webapp"
911 static uint16_t
flow_divert_trie_search(struct flow_divert_trie * trie,const uint8_t * string_bytes)912 flow_divert_trie_search(struct flow_divert_trie *trie, const uint8_t *string_bytes)
913 {
914 uint16_t current = trie->root;
915 uint16_t string_idx = 0;
916
917 while (current != NULL_TRIE_IDX) {
918 uint16_t next = NULL_TRIE_IDX;
919 uint16_t node_end = TRIE_NODE(trie, current).start + TRIE_NODE(trie, current).length;
920 uint16_t node_idx;
921
922 for (node_idx = TRIE_NODE(trie, current).start;
923 node_idx < node_end && string_bytes[string_idx] != '\0' && string_bytes[string_idx] == TRIE_BYTE(trie, node_idx);
924 node_idx++, string_idx++) {
925 ;
926 }
927
928 if (node_idx == node_end) {
929 if (string_bytes[string_idx] == '\0') {
930 return current; /* Got an exact match */
931 } else if (string_idx == strlen(APPLE_WEBCLIP_ID_PREFIX) &&
932 0 == strncmp((const char *)string_bytes, APPLE_WEBCLIP_ID_PREFIX, string_idx)) {
933 return current; /* Got an apple webclip id prefix match */
934 } else if (TRIE_NODE(trie, current).child_map != NULL_TRIE_IDX) {
935 next = TRIE_CHILD(trie, current, string_bytes[string_idx]);
936 }
937 }
938 current = next;
939 }
940
941 return NULL_TRIE_IDX;
942 }
943
944 struct uuid_search_info {
945 uuid_t target_uuid;
946 char *found_signing_id;
947 boolean_t found_multiple_signing_ids;
948 proc_t found_proc;
949 };
950
951 static int
flow_divert_find_proc_by_uuid_callout(proc_t p,void * arg)952 flow_divert_find_proc_by_uuid_callout(proc_t p, void *arg)
953 {
954 struct uuid_search_info *info = (struct uuid_search_info *)arg;
955 int result = PROC_RETURNED_DONE; /* By default, we didn't find the process */
956
957 if (info->found_signing_id != NULL) {
958 if (!info->found_multiple_signing_ids) {
959 /* All processes that were found had the same signing identifier, so just claim this first one and be done. */
960 info->found_proc = p;
961 result = PROC_CLAIMED_DONE;
962 } else {
963 uuid_string_t uuid_str;
964 uuid_unparse(info->target_uuid, uuid_str);
965 FDLOG(LOG_WARNING, &nil_pcb, "Found multiple processes with UUID %s with different signing identifiers", uuid_str);
966 }
967 kfree_data(info->found_signing_id, strlen(info->found_signing_id) + 1);
968 info->found_signing_id = NULL;
969 }
970
971 if (result == PROC_RETURNED_DONE) {
972 uuid_string_t uuid_str;
973 uuid_unparse(info->target_uuid, uuid_str);
974 FDLOG(LOG_WARNING, &nil_pcb, "Failed to find a process with UUID %s", uuid_str);
975 }
976
977 return result;
978 }
979
980 static int
flow_divert_find_proc_by_uuid_filter(proc_t p,void * arg)981 flow_divert_find_proc_by_uuid_filter(proc_t p, void *arg)
982 {
983 struct uuid_search_info *info = (struct uuid_search_info *)arg;
984 int include = 0;
985
986 if (info->found_multiple_signing_ids) {
987 return include;
988 }
989
990 include = (uuid_compare(proc_executableuuid_addr(p), info->target_uuid) == 0);
991 if (include) {
992 const char *signing_id = cs_identity_get(p);
993 if (signing_id != NULL) {
994 FDLOG(LOG_INFO, &nil_pcb, "Found process %d with signing identifier %s", proc_getpid(p), signing_id);
995 size_t signing_id_size = strlen(signing_id) + 1;
996 if (info->found_signing_id == NULL) {
997 info->found_signing_id = kalloc_data(signing_id_size, Z_WAITOK);
998 memcpy(info->found_signing_id, signing_id, signing_id_size);
999 } else if (memcmp(signing_id, info->found_signing_id, signing_id_size)) {
1000 info->found_multiple_signing_ids = TRUE;
1001 }
1002 } else {
1003 info->found_multiple_signing_ids = TRUE;
1004 }
1005 include = !info->found_multiple_signing_ids;
1006 }
1007
1008 return include;
1009 }
1010
1011 static proc_t
flow_divert_find_proc_by_uuid(uuid_t uuid)1012 flow_divert_find_proc_by_uuid(uuid_t uuid)
1013 {
1014 struct uuid_search_info info;
1015
1016 if (LOG_INFO <= nil_pcb.log_level) {
1017 uuid_string_t uuid_str;
1018 uuid_unparse(uuid, uuid_str);
1019 FDLOG(LOG_INFO, &nil_pcb, "Looking for process with UUID %s", uuid_str);
1020 }
1021
1022 memset(&info, 0, sizeof(info));
1023 info.found_proc = PROC_NULL;
1024 uuid_copy(info.target_uuid, uuid);
1025
1026 proc_iterate(PROC_ALLPROCLIST, flow_divert_find_proc_by_uuid_callout, &info, flow_divert_find_proc_by_uuid_filter, &info);
1027
1028 return info.found_proc;
1029 }
1030
1031 static int
flow_divert_add_proc_info(struct flow_divert_pcb * fd_cb,proc_t proc,const char * signing_id,mbuf_t connect_packet,bool is_effective)1032 flow_divert_add_proc_info(struct flow_divert_pcb *fd_cb, proc_t proc, const char *signing_id, mbuf_t connect_packet, bool is_effective)
1033 {
1034 int error = 0;
1035 uint8_t *cdhash = NULL;
1036 audit_token_t audit_token = {};
1037 const char *proc_cs_id = signing_id;
1038
1039 proc_lock(proc);
1040
1041 if (proc_cs_id == NULL) {
1042 if (proc_getcsflags(proc) & (CS_VALID | CS_DEBUGGED)) {
1043 proc_cs_id = cs_identity_get(proc);
1044 } else {
1045 FDLOG0(LOG_ERR, fd_cb, "Signature of proc is invalid");
1046 }
1047 }
1048
1049 if (is_effective) {
1050 lck_rw_lock_shared(&fd_cb->group->lck);
1051 if (!(fd_cb->group->flags & FLOW_DIVERT_GROUP_FLAG_NO_APP_MAP)) {
1052 if (proc_cs_id != NULL) {
1053 uint16_t result = flow_divert_trie_search(&fd_cb->group->signing_id_trie, (const uint8_t *)proc_cs_id);
1054 if (result == NULL_TRIE_IDX) {
1055 FDLOG(LOG_WARNING, fd_cb, "%s did not match", proc_cs_id);
1056 error = EPERM;
1057 } else {
1058 FDLOG(LOG_INFO, fd_cb, "%s matched", proc_cs_id);
1059 }
1060 } else {
1061 error = EPERM;
1062 }
1063 }
1064 lck_rw_done(&fd_cb->group->lck);
1065 }
1066
1067 if (error != 0) {
1068 goto done;
1069 }
1070
1071 /*
1072 * If signing_id is not NULL then it came from the flow divert token and will be added
1073 * as part of the token, so there is no need to add it here.
1074 */
1075 if (signing_id == NULL && proc_cs_id != NULL) {
1076 error = flow_divert_packet_append_tlv(connect_packet,
1077 (is_effective ? FLOW_DIVERT_TLV_SIGNING_ID : FLOW_DIVERT_TLV_APP_REAL_SIGNING_ID),
1078 (uint32_t)strlen(proc_cs_id),
1079 proc_cs_id);
1080 if (error != 0) {
1081 FDLOG(LOG_ERR, fd_cb, "failed to append the signing ID: %d", error);
1082 goto done;
1083 }
1084 }
1085
1086 cdhash = cs_get_cdhash(proc);
1087 if (cdhash != NULL) {
1088 error = flow_divert_packet_append_tlv(connect_packet,
1089 (is_effective ? FLOW_DIVERT_TLV_CDHASH : FLOW_DIVERT_TLV_APP_REAL_CDHASH),
1090 SHA1_RESULTLEN,
1091 cdhash);
1092 if (error) {
1093 FDLOG(LOG_ERR, fd_cb, "failed to append the cdhash: %d", error);
1094 goto done;
1095 }
1096 } else {
1097 FDLOG0(LOG_ERR, fd_cb, "failed to get the cdhash");
1098 }
1099
1100 task_t task = proc_task(proc);
1101 if (task != TASK_NULL) {
1102 mach_msg_type_number_t count = TASK_AUDIT_TOKEN_COUNT;
1103 kern_return_t rc = task_info(task, TASK_AUDIT_TOKEN, (task_info_t)&audit_token, &count);
1104 if (rc == KERN_SUCCESS) {
1105 int append_error = flow_divert_packet_append_tlv(connect_packet,
1106 (is_effective ? FLOW_DIVERT_TLV_APP_AUDIT_TOKEN : FLOW_DIVERT_TLV_APP_REAL_AUDIT_TOKEN),
1107 sizeof(audit_token_t),
1108 &audit_token);
1109 if (append_error) {
1110 FDLOG(LOG_ERR, fd_cb, "failed to append app audit token: %d", append_error);
1111 }
1112 }
1113 }
1114
1115 done:
1116 proc_unlock(proc);
1117
1118 return error;
1119 }
1120
1121 static int
flow_divert_add_all_proc_info(struct flow_divert_pcb * fd_cb,struct socket * so,proc_t proc,const char * signing_id,mbuf_t connect_packet)1122 flow_divert_add_all_proc_info(struct flow_divert_pcb *fd_cb, struct socket *so, proc_t proc, const char *signing_id, mbuf_t connect_packet)
1123 {
1124 int error = 0;
1125 proc_t effective_proc = PROC_NULL;
1126 proc_t responsible_proc = PROC_NULL;
1127 proc_t real_proc = proc_find(so->last_pid);
1128 bool release_real_proc = true;
1129
1130 proc_t src_proc = PROC_NULL;
1131 proc_t real_src_proc = PROC_NULL;
1132
1133 if (real_proc == PROC_NULL) {
1134 FDLOG(LOG_ERR, fd_cb, "failed to find the real proc record for %d", so->last_pid);
1135 release_real_proc = false;
1136 real_proc = proc;
1137 if (real_proc == PROC_NULL) {
1138 real_proc = current_proc();
1139 }
1140 }
1141
1142 if (so->so_flags & SOF_DELEGATED) {
1143 if (proc_getpid(real_proc) != so->e_pid) {
1144 effective_proc = proc_find(so->e_pid);
1145 } else if (uuid_compare(proc_executableuuid_addr(real_proc), so->e_uuid)) {
1146 effective_proc = flow_divert_find_proc_by_uuid(so->e_uuid);
1147 }
1148 }
1149
1150 #if defined(XNU_TARGET_OS_OSX)
1151 lck_rw_lock_shared(&fd_cb->group->lck);
1152 if (!(fd_cb->group->flags & FLOW_DIVERT_GROUP_FLAG_NO_APP_MAP)) {
1153 if (so->so_rpid > 0) {
1154 responsible_proc = proc_find(so->so_rpid);
1155 }
1156 }
1157 lck_rw_done(&fd_cb->group->lck);
1158 #endif
1159
1160 real_src_proc = real_proc;
1161
1162 if (responsible_proc != PROC_NULL) {
1163 src_proc = responsible_proc;
1164 if (effective_proc != NULL) {
1165 real_src_proc = effective_proc;
1166 }
1167 } else if (effective_proc != PROC_NULL) {
1168 src_proc = effective_proc;
1169 } else {
1170 src_proc = real_proc;
1171 }
1172
1173 error = flow_divert_add_proc_info(fd_cb, src_proc, signing_id, connect_packet, true);
1174 if (error != 0) {
1175 goto done;
1176 }
1177
1178 if (real_src_proc != NULL && real_src_proc != src_proc) {
1179 error = flow_divert_add_proc_info(fd_cb, real_src_proc, NULL, connect_packet, false);
1180 if (error != 0) {
1181 goto done;
1182 }
1183 }
1184
1185 done:
1186 if (responsible_proc != PROC_NULL) {
1187 proc_rele(responsible_proc);
1188 }
1189
1190 if (effective_proc != PROC_NULL) {
1191 proc_rele(effective_proc);
1192 }
1193
1194 if (real_proc != PROC_NULL && release_real_proc) {
1195 proc_rele(real_proc);
1196 }
1197
1198 return error;
1199 }
1200
1201 static int
flow_divert_send_packet(struct flow_divert_pcb * fd_cb,mbuf_t packet)1202 flow_divert_send_packet(struct flow_divert_pcb *fd_cb, mbuf_t packet)
1203 {
1204 int error;
1205
1206 if (fd_cb->group == NULL) {
1207 FDLOG0(LOG_INFO, fd_cb, "no provider, cannot send packet");
1208 flow_divert_update_closed_state(fd_cb, SHUT_RDWR, true, false);
1209 flow_divert_disconnect_socket(fd_cb->so, !(fd_cb->flags & FLOW_DIVERT_IMPLICIT_CONNECT), false);
1210 if (SOCK_TYPE(fd_cb->so) == SOCK_STREAM) {
1211 error = ECONNABORTED;
1212 } else {
1213 error = EHOSTUNREACH;
1214 }
1215 fd_cb->so->so_error = (uint16_t)error;
1216 return error;
1217 }
1218
1219 lck_rw_lock_shared(&fd_cb->group->lck);
1220
1221 if (MBUFQ_EMPTY(&fd_cb->group->send_queue)) {
1222 error = ctl_enqueuembuf(g_flow_divert_kctl_ref, fd_cb->group->ctl_unit, packet, CTL_DATA_EOR);
1223 if (error) {
1224 FDLOG(LOG_NOTICE, &nil_pcb, "flow_divert_send_packet: ctl_enqueuembuf returned an error: %d", error);
1225 }
1226 } else {
1227 error = ENOBUFS;
1228 }
1229
1230 if (error == ENOBUFS) {
1231 if (!lck_rw_lock_shared_to_exclusive(&fd_cb->group->lck)) {
1232 lck_rw_lock_exclusive(&fd_cb->group->lck);
1233 }
1234 MBUFQ_ENQUEUE(&fd_cb->group->send_queue, packet);
1235 error = 0;
1236 OSTestAndSet(GROUP_BIT_CTL_ENQUEUE_BLOCKED, &fd_cb->group->atomic_bits);
1237 }
1238
1239 lck_rw_done(&fd_cb->group->lck);
1240
1241 return error;
1242 }
1243
1244 static void
flow_divert_append_domain_name(char * domain_name,void * ctx)1245 flow_divert_append_domain_name(char *domain_name, void *ctx)
1246 {
1247 mbuf_t packet = (mbuf_t)ctx;
1248 size_t domain_name_length = 0;
1249
1250 if (packet == NULL || domain_name == NULL) {
1251 return;
1252 }
1253
1254 domain_name_length = strlen(domain_name);
1255 if (domain_name_length > 0 && domain_name_length < FLOW_DIVERT_MAX_NAME_SIZE) {
1256 int error = flow_divert_packet_append_tlv(packet, FLOW_DIVERT_TLV_TARGET_HOSTNAME, (uint32_t)domain_name_length, domain_name);
1257 if (error) {
1258 FDLOG(LOG_ERR, &nil_pcb, "Failed to append %s: %d", domain_name, error);
1259 }
1260 }
1261 }
1262
1263 static int
flow_divert_create_connect_packet(struct flow_divert_pcb * fd_cb,struct sockaddr * to,struct socket * so,proc_t p,mbuf_t * out_connect_packet)1264 flow_divert_create_connect_packet(struct flow_divert_pcb *fd_cb, struct sockaddr *to, struct socket *so, proc_t p, mbuf_t *out_connect_packet)
1265 {
1266 int error = 0;
1267 int flow_type = 0;
1268 char *signing_id = NULL;
1269 uint32_t sid_size = 0;
1270 mbuf_t connect_packet = NULL;
1271 cfil_sock_id_t cfil_sock_id = CFIL_SOCK_ID_NONE;
1272 const void *cfil_id = NULL;
1273 size_t cfil_id_size = 0;
1274 struct inpcb *inp = sotoinpcb(so);
1275 struct ifnet *ifp = NULL;
1276 uint32_t flags = 0;
1277
1278 error = flow_divert_packet_init(fd_cb, FLOW_DIVERT_PKT_CONNECT, &connect_packet);
1279 if (error) {
1280 goto done;
1281 }
1282
1283 if (fd_cb->connect_token != NULL && (fd_cb->flags & FLOW_DIVERT_HAS_HMAC)) {
1284 int find_error = flow_divert_packet_get_tlv(fd_cb->connect_token, 0, FLOW_DIVERT_TLV_SIGNING_ID, 0, NULL, &sid_size);
1285 if (find_error == 0 && sid_size > 0) {
1286 signing_id = kalloc_data(sid_size + 1, Z_WAITOK | Z_ZERO);
1287 if (signing_id != NULL) {
1288 flow_divert_packet_get_tlv(fd_cb->connect_token, 0, FLOW_DIVERT_TLV_SIGNING_ID, sid_size, signing_id, NULL);
1289 FDLOG(LOG_INFO, fd_cb, "Got %s from token", signing_id);
1290 }
1291 }
1292 }
1293
1294 error = flow_divert_add_all_proc_info(fd_cb, so, p, signing_id, connect_packet);
1295
1296 if (signing_id != NULL) {
1297 kfree_data(signing_id, sid_size + 1);
1298 }
1299
1300 if (error) {
1301 FDLOG(LOG_ERR, fd_cb, "Failed to add source proc info: %d", error);
1302 goto done;
1303 }
1304
1305 error = flow_divert_packet_append_tlv(connect_packet,
1306 FLOW_DIVERT_TLV_TRAFFIC_CLASS,
1307 sizeof(fd_cb->so->so_traffic_class),
1308 &fd_cb->so->so_traffic_class);
1309 if (error) {
1310 goto done;
1311 }
1312
1313 if (SOCK_TYPE(fd_cb->so) == SOCK_STREAM) {
1314 flow_type = FLOW_DIVERT_FLOW_TYPE_TCP;
1315 } else if (SOCK_TYPE(fd_cb->so) == SOCK_DGRAM) {
1316 flow_type = FLOW_DIVERT_FLOW_TYPE_UDP;
1317 } else {
1318 error = EINVAL;
1319 goto done;
1320 }
1321 error = flow_divert_packet_append_tlv(connect_packet,
1322 FLOW_DIVERT_TLV_FLOW_TYPE,
1323 sizeof(flow_type),
1324 &flow_type);
1325
1326 if (error) {
1327 goto done;
1328 }
1329
1330 if (fd_cb->connect_token != NULL) {
1331 unsigned int token_len = m_length(fd_cb->connect_token);
1332 mbuf_concatenate(connect_packet, fd_cb->connect_token);
1333 mbuf_pkthdr_adjustlen(connect_packet, token_len);
1334 fd_cb->connect_token = NULL;
1335 } else {
1336 error = flow_divert_append_target_endpoint_tlv(connect_packet, to);
1337 if (error) {
1338 goto done;
1339 }
1340
1341 necp_with_inp_domain_name(so, connect_packet, flow_divert_append_domain_name);
1342 }
1343
1344 if (fd_cb->local_endpoint.sa.sa_family == AF_INET || fd_cb->local_endpoint.sa.sa_family == AF_INET6) {
1345 error = flow_divert_packet_append_tlv(connect_packet, FLOW_DIVERT_TLV_LOCAL_ADDR, fd_cb->local_endpoint.sa.sa_len, &(fd_cb->local_endpoint.sa));
1346 if (error) {
1347 goto done;
1348 }
1349 }
1350
1351 if (inp->inp_vflag & INP_IPV4) {
1352 ifp = inp->inp_last_outifp;
1353 } else if (inp->inp_vflag & INP_IPV6) {
1354 ifp = inp->in6p_last_outifp;
1355 }
1356 if (ifp != NULL) {
1357 uint32_t flow_if_index = ifp->if_index;
1358 error = flow_divert_packet_append_tlv(connect_packet, FLOW_DIVERT_TLV_OUT_IF_INDEX,
1359 sizeof(flow_if_index), &flow_if_index);
1360 if (error) {
1361 goto done;
1362 }
1363 }
1364
1365 if (so->so_flags1 & SOF1_DATA_IDEMPOTENT) {
1366 flags |= FLOW_DIVERT_TOKEN_FLAG_TFO;
1367 }
1368
1369 if ((inp->inp_flags & INP_BOUND_IF) ||
1370 ((inp->inp_vflag & INP_IPV6) && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) ||
1371 ((inp->inp_vflag & INP_IPV4) && inp->inp_laddr.s_addr != INADDR_ANY)) {
1372 flags |= FLOW_DIVERT_TOKEN_FLAG_BOUND;
1373 }
1374
1375 if (flags != 0) {
1376 error = flow_divert_packet_append_tlv(connect_packet, FLOW_DIVERT_TLV_FLAGS, sizeof(flags), &flags);
1377 if (error) {
1378 goto done;
1379 }
1380 }
1381
1382 if (SOCK_TYPE(so) == SOCK_DGRAM) {
1383 cfil_sock_id = cfil_sock_id_from_datagram_socket(so, NULL, to);
1384 } else {
1385 cfil_sock_id = cfil_sock_id_from_socket(so);
1386 }
1387
1388 if (cfil_sock_id != CFIL_SOCK_ID_NONE) {
1389 cfil_id = &cfil_sock_id;
1390 cfil_id_size = sizeof(cfil_sock_id);
1391 } else if (so->so_flags1 & SOF1_CONTENT_FILTER_SKIP) {
1392 cfil_id = &inp->necp_client_uuid;
1393 cfil_id_size = sizeof(inp->necp_client_uuid);
1394 }
1395
1396 if (cfil_id != NULL && cfil_id_size > 0 && cfil_id_size <= sizeof(uuid_t)) {
1397 error = flow_divert_packet_append_tlv(connect_packet, FLOW_DIVERT_TLV_CFIL_ID, (uint32_t)cfil_id_size, cfil_id);
1398 if (error) {
1399 goto done;
1400 }
1401 }
1402
1403 done:
1404 if (!error) {
1405 *out_connect_packet = connect_packet;
1406 } else if (connect_packet != NULL) {
1407 mbuf_freem(connect_packet);
1408 }
1409
1410 return error;
1411 }
1412
1413 static int
flow_divert_send_connect_packet(struct flow_divert_pcb * fd_cb)1414 flow_divert_send_connect_packet(struct flow_divert_pcb *fd_cb)
1415 {
1416 int error = 0;
1417 mbuf_t connect_packet = fd_cb->connect_packet;
1418 mbuf_t saved_connect_packet = NULL;
1419
1420 if (connect_packet != NULL) {
1421 error = mbuf_copym(connect_packet, 0, mbuf_pkthdr_len(connect_packet), MBUF_DONTWAIT, &saved_connect_packet);
1422 if (error) {
1423 FDLOG0(LOG_ERR, fd_cb, "Failed to copy the connect packet");
1424 goto done;
1425 }
1426
1427 error = flow_divert_send_packet(fd_cb, connect_packet);
1428 if (error) {
1429 goto done;
1430 }
1431
1432 fd_cb->connect_packet = saved_connect_packet;
1433 saved_connect_packet = NULL;
1434 } else {
1435 error = ENOENT;
1436 }
1437 done:
1438 if (saved_connect_packet != NULL) {
1439 mbuf_freem(saved_connect_packet);
1440 }
1441
1442 return error;
1443 }
1444
1445 static int
flow_divert_send_connect_result(struct flow_divert_pcb * fd_cb)1446 flow_divert_send_connect_result(struct flow_divert_pcb *fd_cb)
1447 {
1448 int error = 0;
1449 mbuf_t packet = NULL;
1450 int rbuff_space = 0;
1451
1452 error = flow_divert_packet_init(fd_cb, FLOW_DIVERT_PKT_CONNECT_RESULT, &packet);
1453 if (error) {
1454 FDLOG(LOG_ERR, fd_cb, "failed to create a connect result packet: %d", error);
1455 goto done;
1456 }
1457
1458 rbuff_space = fd_cb->so->so_rcv.sb_hiwat;
1459 if (rbuff_space < 0) {
1460 rbuff_space = 0;
1461 }
1462 rbuff_space = htonl(rbuff_space);
1463 error = flow_divert_packet_append_tlv(packet,
1464 FLOW_DIVERT_TLV_SPACE_AVAILABLE,
1465 sizeof(rbuff_space),
1466 &rbuff_space);
1467 if (error) {
1468 goto done;
1469 }
1470
1471 if (fd_cb->local_endpoint.sa.sa_family == AF_INET || fd_cb->local_endpoint.sa.sa_family == AF_INET6) {
1472 error = flow_divert_packet_append_tlv(packet, FLOW_DIVERT_TLV_LOCAL_ADDR, fd_cb->local_endpoint.sa.sa_len, &(fd_cb->local_endpoint.sa));
1473 if (error) {
1474 goto done;
1475 }
1476 }
1477
1478 error = flow_divert_send_packet(fd_cb, packet);
1479 if (error) {
1480 goto done;
1481 }
1482
1483 done:
1484 if (error && packet != NULL) {
1485 mbuf_freem(packet);
1486 }
1487
1488 return error;
1489 }
1490
1491 static int
flow_divert_send_close(struct flow_divert_pcb * fd_cb,int how)1492 flow_divert_send_close(struct flow_divert_pcb *fd_cb, int how)
1493 {
1494 int error = 0;
1495 mbuf_t packet = NULL;
1496 uint32_t zero = 0;
1497
1498 error = flow_divert_packet_init(fd_cb, FLOW_DIVERT_PKT_CLOSE, &packet);
1499 if (error) {
1500 FDLOG(LOG_ERR, fd_cb, "failed to create a close packet: %d", error);
1501 goto done;
1502 }
1503
1504 error = flow_divert_packet_append_tlv(packet, FLOW_DIVERT_TLV_ERROR_CODE, sizeof(zero), &zero);
1505 if (error) {
1506 FDLOG(LOG_ERR, fd_cb, "failed to add the error code TLV: %d", error);
1507 goto done;
1508 }
1509
1510 how = htonl(how);
1511 error = flow_divert_packet_append_tlv(packet, FLOW_DIVERT_TLV_HOW, sizeof(how), &how);
1512 if (error) {
1513 FDLOG(LOG_ERR, fd_cb, "failed to add the how flag: %d", error);
1514 goto done;
1515 }
1516
1517 error = flow_divert_send_packet(fd_cb, packet);
1518 if (error) {
1519 goto done;
1520 }
1521
1522 done:
1523 if (error && packet != NULL) {
1524 mbuf_free(packet);
1525 }
1526
1527 return error;
1528 }
1529
1530 static int
flow_divert_tunnel_how_closed(struct flow_divert_pcb * fd_cb)1531 flow_divert_tunnel_how_closed(struct flow_divert_pcb *fd_cb)
1532 {
1533 if ((fd_cb->flags & (FLOW_DIVERT_TUNNEL_RD_CLOSED | FLOW_DIVERT_TUNNEL_WR_CLOSED)) ==
1534 (FLOW_DIVERT_TUNNEL_RD_CLOSED | FLOW_DIVERT_TUNNEL_WR_CLOSED)) {
1535 return SHUT_RDWR;
1536 } else if (fd_cb->flags & FLOW_DIVERT_TUNNEL_RD_CLOSED) {
1537 return SHUT_RD;
1538 } else if (fd_cb->flags & FLOW_DIVERT_TUNNEL_WR_CLOSED) {
1539 return SHUT_WR;
1540 }
1541
1542 return -1;
1543 }
1544
1545 /*
1546 * Determine what close messages if any need to be sent to the tunnel. Returns TRUE if the tunnel is closed for both reads and
1547 * writes. Returns FALSE otherwise.
1548 */
1549 static void
flow_divert_send_close_if_needed(struct flow_divert_pcb * fd_cb)1550 flow_divert_send_close_if_needed(struct flow_divert_pcb *fd_cb)
1551 {
1552 int how = -1;
1553
1554 /* Do not send any close messages if there is still data in the send buffer */
1555 if (fd_cb->so->so_snd.sb_cc == 0) {
1556 if ((fd_cb->flags & (FLOW_DIVERT_READ_CLOSED | FLOW_DIVERT_TUNNEL_RD_CLOSED)) == FLOW_DIVERT_READ_CLOSED) {
1557 /* Socket closed reads, but tunnel did not. Tell tunnel to close reads */
1558 how = SHUT_RD;
1559 }
1560 if ((fd_cb->flags & (FLOW_DIVERT_WRITE_CLOSED | FLOW_DIVERT_TUNNEL_WR_CLOSED)) == FLOW_DIVERT_WRITE_CLOSED) {
1561 /* Socket closed writes, but tunnel did not. Tell tunnel to close writes */
1562 if (how == SHUT_RD) {
1563 how = SHUT_RDWR;
1564 } else {
1565 how = SHUT_WR;
1566 }
1567 }
1568 }
1569
1570 if (how != -1) {
1571 FDLOG(LOG_INFO, fd_cb, "sending close, how = %d", how);
1572 if (flow_divert_send_close(fd_cb, how) != ENOBUFS) {
1573 /* Successfully sent the close packet. Record the ways in which the tunnel has been closed */
1574 if (how != SHUT_RD) {
1575 fd_cb->flags |= FLOW_DIVERT_TUNNEL_WR_CLOSED;
1576 }
1577 if (how != SHUT_WR) {
1578 fd_cb->flags |= FLOW_DIVERT_TUNNEL_RD_CLOSED;
1579 }
1580 }
1581 }
1582
1583 if (flow_divert_tunnel_how_closed(fd_cb) == SHUT_RDWR) {
1584 flow_divert_disconnect_socket(fd_cb->so, !(fd_cb->flags & FLOW_DIVERT_IMPLICIT_CONNECT), false);
1585 }
1586 }
1587
1588 static errno_t
flow_divert_send_data_packet(struct flow_divert_pcb * fd_cb,mbuf_t data,size_t data_len)1589 flow_divert_send_data_packet(struct flow_divert_pcb *fd_cb, mbuf_t data, size_t data_len)
1590 {
1591 mbuf_t packet = NULL;
1592 mbuf_t last = NULL;
1593 int error = 0;
1594
1595 error = flow_divert_packet_init(fd_cb, FLOW_DIVERT_PKT_DATA, &packet);
1596 if (error || packet == NULL) {
1597 FDLOG(LOG_ERR, fd_cb, "flow_divert_packet_init failed: %d", error);
1598 goto done;
1599 }
1600
1601 if (data_len > 0 && data_len <= INT_MAX && data != NULL) {
1602 last = m_last(packet);
1603 mbuf_setnext(last, data);
1604 mbuf_pkthdr_adjustlen(packet, (int)data_len);
1605 } else {
1606 data_len = 0;
1607 }
1608 error = flow_divert_send_packet(fd_cb, packet);
1609 if (error == 0 && data_len > 0) {
1610 fd_cb->bytes_sent += data_len;
1611 flow_divert_add_data_statistics(fd_cb, data_len, TRUE);
1612 }
1613
1614 done:
1615 if (error) {
1616 if (last != NULL) {
1617 mbuf_setnext(last, NULL);
1618 }
1619 if (packet != NULL) {
1620 mbuf_freem(packet);
1621 }
1622 }
1623
1624 return error;
1625 }
1626
1627 static errno_t
flow_divert_send_datagram_packet(struct flow_divert_pcb * fd_cb,mbuf_t data,size_t data_len,struct sockaddr * toaddr,Boolean is_fragment,size_t datagram_size)1628 flow_divert_send_datagram_packet(struct flow_divert_pcb *fd_cb, mbuf_t data, size_t data_len, struct sockaddr *toaddr, Boolean is_fragment, size_t datagram_size)
1629 {
1630 mbuf_t packet = NULL;
1631 mbuf_t last = NULL;
1632 int error = 0;
1633
1634 error = flow_divert_packet_init(fd_cb, FLOW_DIVERT_PKT_DATA, &packet);
1635 if (error || packet == NULL) {
1636 FDLOG(LOG_ERR, fd_cb, "flow_divert_packet_init failed: %d", error);
1637 goto done;
1638 }
1639
1640 if (toaddr != NULL) {
1641 error = flow_divert_append_target_endpoint_tlv(packet, toaddr);
1642 if (error) {
1643 FDLOG(LOG_ERR, fd_cb, "flow_divert_append_target_endpoint_tlv() failed: %d", error);
1644 goto done;
1645 }
1646 }
1647 if (is_fragment) {
1648 error = flow_divert_packet_append_tlv(packet, FLOW_DIVERT_TLV_IS_FRAGMENT, sizeof(is_fragment), &is_fragment);
1649 if (error) {
1650 FDLOG(LOG_ERR, fd_cb, "flow_divert_packet_append_tlv(FLOW_DIVERT_TLV_IS_FRAGMENT) failed: %d", error);
1651 goto done;
1652 }
1653 }
1654
1655 error = flow_divert_packet_append_tlv(packet, FLOW_DIVERT_TLV_DATAGRAM_SIZE, sizeof(datagram_size), &datagram_size);
1656 if (error) {
1657 FDLOG(LOG_ERR, fd_cb, "flow_divert_packet_append_tlv(FLOW_DIVERT_TLV_DATAGRAM_SIZE) failed: %d", error);
1658 goto done;
1659 }
1660
1661 if (data_len > 0 && data_len <= INT_MAX && data != NULL) {
1662 last = m_last(packet);
1663 mbuf_setnext(last, data);
1664 mbuf_pkthdr_adjustlen(packet, (int)data_len);
1665 } else {
1666 data_len = 0;
1667 }
1668 error = flow_divert_send_packet(fd_cb, packet);
1669 if (error == 0 && data_len > 0) {
1670 fd_cb->bytes_sent += data_len;
1671 flow_divert_add_data_statistics(fd_cb, data_len, TRUE);
1672 }
1673
1674 done:
1675 if (error) {
1676 if (last != NULL) {
1677 mbuf_setnext(last, NULL);
1678 }
1679 if (packet != NULL) {
1680 mbuf_freem(packet);
1681 }
1682 }
1683
1684 return error;
1685 }
1686
1687 static errno_t
flow_divert_send_fragmented_datagram(struct flow_divert_pcb * fd_cb,mbuf_t datagram,size_t datagram_len,struct sockaddr * toaddr)1688 flow_divert_send_fragmented_datagram(struct flow_divert_pcb *fd_cb, mbuf_t datagram, size_t datagram_len, struct sockaddr *toaddr)
1689 {
1690 mbuf_t next_data = datagram;
1691 size_t remaining_len = datagram_len;
1692 mbuf_t remaining_data = NULL;
1693 int error = 0;
1694 bool first = true;
1695
1696 while (remaining_len > 0 && next_data != NULL) {
1697 size_t to_send = remaining_len;
1698 remaining_data = NULL;
1699
1700 if (to_send > FLOW_DIVERT_CHUNK_SIZE) {
1701 to_send = FLOW_DIVERT_CHUNK_SIZE;
1702 error = mbuf_split(next_data, to_send, MBUF_DONTWAIT, &remaining_data);
1703 if (error) {
1704 break;
1705 }
1706 }
1707
1708 error = flow_divert_send_datagram_packet(fd_cb, next_data, to_send, (first ? toaddr : NULL), TRUE, (first ? datagram_len : 0));
1709 if (error) {
1710 break;
1711 }
1712
1713 first = false;
1714 remaining_len -= to_send;
1715 next_data = remaining_data;
1716 }
1717
1718 if (error) {
1719 if (next_data != NULL) {
1720 mbuf_freem(next_data);
1721 }
1722 if (remaining_data != NULL) {
1723 mbuf_freem(remaining_data);
1724 }
1725 }
1726 return error;
1727 }
1728
1729 static void
flow_divert_send_buffered_data(struct flow_divert_pcb * fd_cb,Boolean force)1730 flow_divert_send_buffered_data(struct flow_divert_pcb *fd_cb, Boolean force)
1731 {
1732 size_t to_send;
1733 size_t sent = 0;
1734 int error = 0;
1735 mbuf_t buffer;
1736
1737 to_send = fd_cb->so->so_snd.sb_cc;
1738 buffer = fd_cb->so->so_snd.sb_mb;
1739
1740 if (buffer == NULL && to_send > 0) {
1741 FDLOG(LOG_ERR, fd_cb, "Send buffer is NULL, but size is supposed to be %lu", to_send);
1742 return;
1743 }
1744
1745 /* Ignore the send window if force is enabled */
1746 if (!force && (to_send > fd_cb->send_window)) {
1747 to_send = fd_cb->send_window;
1748 }
1749
1750 if (SOCK_TYPE(fd_cb->so) == SOCK_STREAM) {
1751 while (sent < to_send) {
1752 mbuf_t data;
1753 size_t data_len;
1754
1755 data_len = to_send - sent;
1756 if (data_len > FLOW_DIVERT_CHUNK_SIZE) {
1757 data_len = FLOW_DIVERT_CHUNK_SIZE;
1758 }
1759
1760 error = mbuf_copym(buffer, sent, data_len, MBUF_DONTWAIT, &data);
1761 if (error) {
1762 FDLOG(LOG_ERR, fd_cb, "mbuf_copym failed: %d", error);
1763 break;
1764 }
1765
1766 error = flow_divert_send_data_packet(fd_cb, data, data_len);
1767 if (error) {
1768 if (data != NULL) {
1769 mbuf_freem(data);
1770 }
1771 break;
1772 }
1773
1774 sent += data_len;
1775 }
1776 sbdrop(&fd_cb->so->so_snd, (int)sent);
1777 sowwakeup(fd_cb->so);
1778 } else if (SOCK_TYPE(fd_cb->so) == SOCK_DGRAM) {
1779 mbuf_t data;
1780 mbuf_t m;
1781 size_t data_len;
1782
1783 while (buffer) {
1784 struct sockaddr *toaddr = flow_divert_get_buffered_target_address(buffer);
1785
1786 m = buffer;
1787 if (toaddr != NULL) {
1788 /* look for data in the chain */
1789 do {
1790 m = m->m_next;
1791 if (m != NULL && m->m_type == MT_DATA) {
1792 break;
1793 }
1794 } while (m);
1795 if (m == NULL) {
1796 /* unexpected */
1797 FDLOG0(LOG_ERR, fd_cb, "failed to find type MT_DATA in the mbuf chain.");
1798 goto move_on;
1799 }
1800 }
1801 data_len = mbuf_pkthdr_len(m);
1802 if (data_len > 0) {
1803 FDLOG(LOG_DEBUG, fd_cb, "mbuf_copym() data_len = %lu", data_len);
1804 error = mbuf_copym(m, 0, data_len, MBUF_DONTWAIT, &data);
1805 if (error) {
1806 FDLOG(LOG_ERR, fd_cb, "mbuf_copym failed: %d", error);
1807 break;
1808 }
1809 } else {
1810 data = NULL;
1811 }
1812 if (data_len <= FLOW_DIVERT_CHUNK_SIZE) {
1813 error = flow_divert_send_datagram_packet(fd_cb, data, data_len, toaddr, FALSE, 0);
1814 } else {
1815 error = flow_divert_send_fragmented_datagram(fd_cb, data, data_len, toaddr);
1816 data = NULL;
1817 }
1818 if (error) {
1819 if (data != NULL) {
1820 mbuf_freem(data);
1821 }
1822 break;
1823 }
1824 sent += data_len;
1825 move_on:
1826 buffer = buffer->m_nextpkt;
1827 (void) sbdroprecord(&(fd_cb->so->so_snd));
1828 }
1829 }
1830
1831 if (sent > 0) {
1832 FDLOG(LOG_DEBUG, fd_cb, "sent %lu bytes of buffered data", sent);
1833 if (fd_cb->send_window >= sent) {
1834 fd_cb->send_window -= sent;
1835 } else {
1836 fd_cb->send_window = 0;
1837 }
1838 }
1839 }
1840
1841 static int
flow_divert_send_app_data(struct flow_divert_pcb * fd_cb,mbuf_t data,size_t data_size,struct sockaddr * toaddr)1842 flow_divert_send_app_data(struct flow_divert_pcb *fd_cb, mbuf_t data, size_t data_size, struct sockaddr *toaddr)
1843 {
1844 size_t to_send = data_size;
1845 int error = 0;
1846
1847 if (to_send > fd_cb->send_window) {
1848 to_send = fd_cb->send_window;
1849 }
1850
1851 if (fd_cb->so->so_snd.sb_cc > 0) {
1852 to_send = 0; /* If the send buffer is non-empty, then we can't send anything */
1853 }
1854
1855 if (SOCK_TYPE(fd_cb->so) == SOCK_STREAM) {
1856 size_t sent = 0;
1857 mbuf_t remaining_data = data;
1858 size_t remaining_size = data_size;
1859 mbuf_t pkt_data = NULL;
1860
1861 while (sent < to_send && remaining_data != NULL && remaining_size > 0) {
1862 size_t pkt_data_len;
1863
1864 pkt_data = remaining_data;
1865
1866 if ((to_send - sent) > FLOW_DIVERT_CHUNK_SIZE) {
1867 pkt_data_len = FLOW_DIVERT_CHUNK_SIZE;
1868 } else {
1869 pkt_data_len = to_send - sent;
1870 }
1871
1872 if (pkt_data_len < remaining_size) {
1873 error = mbuf_split(pkt_data, pkt_data_len, MBUF_DONTWAIT, &remaining_data);
1874 if (error) {
1875 FDLOG(LOG_ERR, fd_cb, "mbuf_split failed: %d", error);
1876 pkt_data = NULL;
1877 break;
1878 }
1879 remaining_size -= pkt_data_len;
1880 } else {
1881 remaining_data = NULL;
1882 remaining_size = 0;
1883 }
1884
1885 error = flow_divert_send_data_packet(fd_cb, pkt_data, pkt_data_len);
1886 if (error) {
1887 break;
1888 }
1889
1890 pkt_data = NULL;
1891 sent += pkt_data_len;
1892 }
1893
1894 if (fd_cb->send_window >= sent) {
1895 fd_cb->send_window -= sent;
1896 } else {
1897 fd_cb->send_window = 0;
1898 }
1899
1900 error = 0;
1901
1902 if (pkt_data != NULL) {
1903 if (sbspace(&fd_cb->so->so_snd) > 0) {
1904 if (!sbappendstream(&fd_cb->so->so_snd, pkt_data)) {
1905 FDLOG(LOG_ERR, fd_cb, "sbappendstream failed with pkt_data, send buffer size = %u, send_window = %u\n",
1906 fd_cb->so->so_snd.sb_cc, fd_cb->send_window);
1907 }
1908 } else {
1909 mbuf_freem(pkt_data);
1910 error = ENOBUFS;
1911 }
1912 }
1913
1914 if (remaining_data != NULL) {
1915 if (sbspace(&fd_cb->so->so_snd) > 0) {
1916 if (!sbappendstream(&fd_cb->so->so_snd, remaining_data)) {
1917 FDLOG(LOG_ERR, fd_cb, "sbappendstream failed with remaining_data, send buffer size = %u, send_window = %u\n",
1918 fd_cb->so->so_snd.sb_cc, fd_cb->send_window);
1919 }
1920 } else {
1921 mbuf_freem(remaining_data);
1922 error = ENOBUFS;
1923 }
1924 }
1925 } else if (SOCK_TYPE(fd_cb->so) == SOCK_DGRAM) {
1926 int send_dgram_error = 0;
1927 if (to_send || data_size == 0) {
1928 if (data_size <= FLOW_DIVERT_CHUNK_SIZE) {
1929 send_dgram_error = flow_divert_send_datagram_packet(fd_cb, data, data_size, toaddr, FALSE, 0);
1930 } else {
1931 send_dgram_error = flow_divert_send_fragmented_datagram(fd_cb, data, data_size, toaddr);
1932 data = NULL;
1933 }
1934 if (send_dgram_error) {
1935 FDLOG(LOG_NOTICE, fd_cb, "flow_divert_send_datagram_packet failed with error %d, send data size = %lu", send_dgram_error, data_size);
1936 } else {
1937 if (data_size >= fd_cb->send_window) {
1938 fd_cb->send_window = 0;
1939 } else {
1940 fd_cb->send_window -= data_size;
1941 }
1942 data = NULL;
1943 }
1944 }
1945
1946 if (data != NULL) {
1947 /* buffer it */
1948 if (sbspace(&fd_cb->so->so_snd) > 0) {
1949 if (toaddr != NULL) {
1950 int append_error = 0;
1951 if (!sbappendaddr(&fd_cb->so->so_snd, toaddr, data, NULL, &append_error)) {
1952 FDLOG(LOG_ERR, fd_cb,
1953 "sbappendaddr failed. send buffer size = %u, send_window = %u, error = %d",
1954 fd_cb->so->so_snd.sb_cc, fd_cb->send_window, append_error);
1955 }
1956 } else {
1957 if (!sbappendrecord(&fd_cb->so->so_snd, data)) {
1958 FDLOG(LOG_ERR, fd_cb,
1959 "sbappendrecord failed. send buffer size = %u, send_window = %u",
1960 fd_cb->so->so_snd.sb_cc, fd_cb->send_window);
1961 }
1962 }
1963 } else {
1964 FDLOG(LOG_ERR, fd_cb, "flow_divert_send_datagram_packet failed with error %d, send data size = %lu, dropping the datagram", error, data_size);
1965 mbuf_freem(data);
1966 }
1967 }
1968 }
1969
1970 return error;
1971 }
1972
1973 static int
flow_divert_send_read_notification(struct flow_divert_pcb * fd_cb)1974 flow_divert_send_read_notification(struct flow_divert_pcb *fd_cb)
1975 {
1976 int error = 0;
1977 mbuf_t packet = NULL;
1978
1979 error = flow_divert_packet_init(fd_cb, FLOW_DIVERT_PKT_READ_NOTIFY, &packet);
1980 if (error) {
1981 FDLOG(LOG_ERR, fd_cb, "failed to create a read notification packet: %d", error);
1982 goto done;
1983 }
1984
1985 error = flow_divert_send_packet(fd_cb, packet);
1986 if (error) {
1987 goto done;
1988 }
1989
1990 done:
1991 if (error && packet != NULL) {
1992 mbuf_free(packet);
1993 }
1994
1995 return error;
1996 }
1997
1998 static int
flow_divert_send_traffic_class_update(struct flow_divert_pcb * fd_cb,int traffic_class)1999 flow_divert_send_traffic_class_update(struct flow_divert_pcb *fd_cb, int traffic_class)
2000 {
2001 int error = 0;
2002 mbuf_t packet = NULL;
2003
2004 error = flow_divert_packet_init(fd_cb, FLOW_DIVERT_PKT_PROPERTIES_UPDATE, &packet);
2005 if (error) {
2006 FDLOG(LOG_ERR, fd_cb, "failed to create a properties update packet: %d", error);
2007 goto done;
2008 }
2009
2010 error = flow_divert_packet_append_tlv(packet, FLOW_DIVERT_TLV_TRAFFIC_CLASS, sizeof(traffic_class), &traffic_class);
2011 if (error) {
2012 FDLOG(LOG_ERR, fd_cb, "failed to add the traffic class: %d", error);
2013 goto done;
2014 }
2015
2016 error = flow_divert_send_packet(fd_cb, packet);
2017 if (error) {
2018 goto done;
2019 }
2020
2021 done:
2022 if (error && packet != NULL) {
2023 mbuf_free(packet);
2024 }
2025
2026 return error;
2027 }
2028
2029 static void
flow_divert_set_local_endpoint(struct flow_divert_pcb * fd_cb,struct sockaddr * local_endpoint)2030 flow_divert_set_local_endpoint(struct flow_divert_pcb *fd_cb, struct sockaddr *local_endpoint)
2031 {
2032 struct inpcb *inp = sotoinpcb(fd_cb->so);
2033
2034 if (local_endpoint->sa_family == AF_INET6) {
2035 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && (fd_cb->flags & FLOW_DIVERT_SHOULD_SET_LOCAL_ADDR)) {
2036 fd_cb->flags |= FLOW_DIVERT_DID_SET_LOCAL_ADDR;
2037 inp->in6p_laddr = (satosin6(local_endpoint))->sin6_addr;
2038 inp->inp_lifscope = (satosin6(local_endpoint))->sin6_scope_id;
2039 in6_verify_ifscope(&inp->in6p_laddr, inp->inp_lifscope);
2040 }
2041 if (inp->inp_lport == 0) {
2042 inp->inp_lport = (satosin6(local_endpoint))->sin6_port;
2043 }
2044 } else if (local_endpoint->sa_family == AF_INET) {
2045 if (inp->inp_laddr.s_addr == INADDR_ANY && (fd_cb->flags & FLOW_DIVERT_SHOULD_SET_LOCAL_ADDR)) {
2046 fd_cb->flags |= FLOW_DIVERT_DID_SET_LOCAL_ADDR;
2047 inp->inp_laddr = (satosin(local_endpoint))->sin_addr;
2048 }
2049 if (inp->inp_lport == 0) {
2050 inp->inp_lport = (satosin(local_endpoint))->sin_port;
2051 }
2052 }
2053 }
2054
2055 static void
flow_divert_set_remote_endpoint(struct flow_divert_pcb * fd_cb,struct sockaddr * remote_endpoint)2056 flow_divert_set_remote_endpoint(struct flow_divert_pcb *fd_cb, struct sockaddr *remote_endpoint)
2057 {
2058 struct inpcb *inp = sotoinpcb(fd_cb->so);
2059
2060 if (remote_endpoint->sa_family == AF_INET6) {
2061 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
2062 inp->in6p_faddr = (satosin6(remote_endpoint))->sin6_addr;
2063 inp->inp_fifscope = (satosin6(remote_endpoint))->sin6_scope_id;
2064 in6_verify_ifscope(&inp->in6p_faddr, inp->inp_fifscope);
2065 }
2066 if (inp->inp_fport == 0) {
2067 inp->inp_fport = (satosin6(remote_endpoint))->sin6_port;
2068 }
2069 } else if (remote_endpoint->sa_family == AF_INET) {
2070 if (inp->inp_faddr.s_addr == INADDR_ANY) {
2071 inp->inp_faddr = (satosin(remote_endpoint))->sin_addr;
2072 }
2073 if (inp->inp_fport == 0) {
2074 inp->inp_fport = (satosin(remote_endpoint))->sin_port;
2075 }
2076 }
2077 }
2078
2079 static uint32_t
flow_divert_derive_kernel_control_unit(pid_t pid,uint32_t * ctl_unit,uint32_t * aggregate_unit,bool * is_aggregate)2080 flow_divert_derive_kernel_control_unit(pid_t pid, uint32_t *ctl_unit, uint32_t *aggregate_unit, bool *is_aggregate)
2081 {
2082 uint32_t result = *ctl_unit;
2083
2084 // There are two models supported for deriving control units:
2085 // 1. A series of flow divert units that allow "transparently" failing
2086 // over to the next unit. For this model, the aggregate_unit contains list
2087 // of all control units (between 1 and 30) masked over each other.
2088 // 2. An indication that in-process flow divert should be preferred, with
2089 // an out of process flow divert to fail over to. For this model, the
2090 // ctl_unit is FLOW_DIVERT_IN_PROCESS_UNIT. In this case, that unit
2091 // is returned first, with the unpacked aggregate unit returned as a
2092 // fallback.
2093 *is_aggregate = false;
2094 if (*ctl_unit == FLOW_DIVERT_IN_PROCESS_UNIT) {
2095 bool found_unit = false;
2096 if (pid != 0) {
2097 // Look for an in-process group that is already open, and use that unit
2098 struct flow_divert_group *group = NULL;
2099 TAILQ_FOREACH(group, &g_flow_divert_in_process_group_list, chain) {
2100 if (group->in_process_pid == pid) {
2101 // Found an in-process group for our same PID, use it
2102 found_unit = true;
2103 result = group->ctl_unit;
2104 break;
2105 }
2106 }
2107
2108 // If an in-process group isn't open yet, send a signal up through NECP to request one
2109 if (!found_unit) {
2110 necp_client_request_in_process_flow_divert(pid);
2111 }
2112 }
2113
2114 // If a unit was found, return it
2115 if (found_unit) {
2116 if (aggregate_unit != NULL && *aggregate_unit != 0) {
2117 *is_aggregate = true;
2118 }
2119 // The next time around, the aggregate unit values will be picked up
2120 *ctl_unit = 0;
2121 return result;
2122 }
2123
2124 // If no unit was found, fall through and clear out the ctl_unit
2125 result = 0;
2126 *ctl_unit = 0;
2127 }
2128
2129 if (aggregate_unit != NULL && *aggregate_unit != 0) {
2130 uint32_t counter;
2131 struct flow_divert_group *lower_order_group = NULL;
2132
2133 for (counter = 0; counter < (GROUP_COUNT_MAX - 1); counter++) {
2134 if ((*aggregate_unit) & (1 << counter)) {
2135 struct flow_divert_group *group = NULL;
2136 group = flow_divert_group_lookup(counter + 1, NULL);
2137
2138 if (group != NULL) {
2139 if (lower_order_group == NULL) {
2140 lower_order_group = group;
2141 } else if ((group->order < lower_order_group->order)) {
2142 lower_order_group = group;
2143 }
2144 }
2145 }
2146 }
2147
2148 if (lower_order_group != NULL) {
2149 *aggregate_unit &= ~(1 << (lower_order_group->ctl_unit - 1));
2150 *is_aggregate = true;
2151 return lower_order_group->ctl_unit;
2152 } else {
2153 *ctl_unit = 0;
2154 return result;
2155 }
2156 } else {
2157 *ctl_unit = 0;
2158 return result;
2159 }
2160 }
2161
2162 static int
flow_divert_try_next_group(struct flow_divert_pcb * fd_cb)2163 flow_divert_try_next_group(struct flow_divert_pcb *fd_cb)
2164 {
2165 int error = 0;
2166 uint32_t policy_control_unit = fd_cb->policy_control_unit;
2167
2168 flow_divert_pcb_remove(fd_cb);
2169
2170 do {
2171 struct flow_divert_group *next_group = NULL;
2172 bool is_aggregate = false;
2173 uint32_t next_ctl_unit = flow_divert_derive_kernel_control_unit(0, &policy_control_unit, &(fd_cb->aggregate_unit), &is_aggregate);
2174
2175 if (fd_cb->control_group_unit == next_ctl_unit) {
2176 FDLOG0(LOG_NOTICE, fd_cb, "Next control unit is the same as the current control unit, disabling flow divert");
2177 error = EALREADY;
2178 break;
2179 }
2180
2181 if (next_ctl_unit == 0 || next_ctl_unit >= GROUP_COUNT_MAX) {
2182 FDLOG0(LOG_NOTICE, fd_cb, "No more valid control units, disabling flow divert");
2183 error = ENOENT;
2184 break;
2185 }
2186
2187 next_group = flow_divert_group_lookup(next_ctl_unit, fd_cb);
2188 if (next_group == NULL) {
2189 FDLOG(LOG_NOTICE, fd_cb, "Group for control unit %u does not exist", next_ctl_unit);
2190 continue;
2191 }
2192
2193 FDLOG(LOG_NOTICE, fd_cb, "Moving from %u to %u", fd_cb->control_group_unit, next_ctl_unit);
2194
2195 error = flow_divert_pcb_insert(fd_cb, next_group);
2196 if (error == 0) {
2197 if (is_aggregate) {
2198 fd_cb->flags |= FLOW_DIVERT_FLOW_IS_TRANSPARENT;
2199 } else {
2200 fd_cb->flags &= ~FLOW_DIVERT_FLOW_IS_TRANSPARENT;
2201 }
2202 }
2203 FDGRP_RELEASE(next_group);
2204 } while (fd_cb->group == NULL);
2205
2206 if (fd_cb->group == NULL) {
2207 return error ? error : ENOENT;
2208 }
2209
2210 error = flow_divert_send_connect_packet(fd_cb);
2211 if (error) {
2212 FDLOG(LOG_NOTICE, fd_cb, "Failed to send the connect packet to %u, disabling flow divert", fd_cb->control_group_unit);
2213 flow_divert_pcb_remove(fd_cb);
2214 error = ENOENT;
2215 }
2216
2217 return error;
2218 }
2219
2220 static void
flow_divert_disable(struct flow_divert_pcb * fd_cb)2221 flow_divert_disable(struct flow_divert_pcb *fd_cb)
2222 {
2223 struct socket *so = NULL;
2224 mbuf_t buffer;
2225 int error = 0;
2226 proc_t last_proc = NULL;
2227 struct sockaddr *remote_endpoint = fd_cb->original_remote_endpoint;
2228 bool do_connect = !(fd_cb->flags & FLOW_DIVERT_IMPLICIT_CONNECT);
2229 struct inpcb *inp = NULL;
2230
2231 so = fd_cb->so;
2232 if (so == NULL) {
2233 goto done;
2234 }
2235
2236 FDLOG0(LOG_NOTICE, fd_cb, "Skipped all flow divert services, disabling flow divert");
2237
2238 /* Restore the IP state */
2239 inp = sotoinpcb(so);
2240 inp->inp_vflag = fd_cb->original_vflag;
2241 inp->inp_faddr.s_addr = INADDR_ANY;
2242 inp->inp_fport = 0;
2243 memset(&(inp->in6p_faddr), 0, sizeof(inp->in6p_faddr));
2244 inp->inp_fifscope = IFSCOPE_NONE;
2245 inp->in6p_fport = 0;
2246 /* If flow divert set the local address, clear it out */
2247 if (fd_cb->flags & FLOW_DIVERT_DID_SET_LOCAL_ADDR) {
2248 inp->inp_laddr.s_addr = INADDR_ANY;
2249 memset(&(inp->in6p_laddr), 0, sizeof(inp->in6p_laddr));
2250 inp->inp_lifscope = IFSCOPE_NONE;
2251 }
2252 inp->inp_last_outifp = fd_cb->original_last_outifp;
2253 inp->in6p_last_outifp = fd_cb->original_last_outifp6;
2254
2255 /* Dis-associate the socket */
2256 so->so_flags &= ~SOF_FLOW_DIVERT;
2257 so->so_flags1 |= SOF1_FLOW_DIVERT_SKIP;
2258 so->so_fd_pcb = NULL;
2259 fd_cb->so = NULL;
2260
2261 FDRELEASE(fd_cb); /* Release the socket's reference */
2262
2263 /* Revert back to the original protocol */
2264 so->so_proto = pffindproto(SOCK_DOM(so), SOCK_PROTO(so), SOCK_TYPE(so));
2265
2266 /* Reset the socket state to avoid confusing NECP */
2267 so->so_state &= ~(SS_ISCONNECTING | SS_ISCONNECTED);
2268
2269 last_proc = proc_find(so->last_pid);
2270
2271 if (do_connect) {
2272 /* Connect using the original protocol */
2273 error = (*so->so_proto->pr_usrreqs->pru_connect)(so, remote_endpoint, (last_proc != NULL ? last_proc : current_proc()));
2274 if (error) {
2275 FDLOG(LOG_ERR, fd_cb, "Failed to connect using the socket's original protocol: %d", error);
2276 goto done;
2277 }
2278 }
2279
2280 buffer = so->so_snd.sb_mb;
2281 if (buffer == NULL) {
2282 /* No buffered data, done */
2283 goto done;
2284 }
2285
2286 /* Send any buffered data using the original protocol */
2287 if (SOCK_TYPE(so) == SOCK_STREAM) {
2288 mbuf_t data_to_send = NULL;
2289 size_t data_len = so->so_snd.sb_cc;
2290
2291 error = mbuf_copym(buffer, 0, data_len, MBUF_DONTWAIT, &data_to_send);
2292 if (error) {
2293 FDLOG0(LOG_ERR, fd_cb, "Failed to copy the mbuf chain in the socket's send buffer");
2294 goto done;
2295 }
2296
2297 sbflush(&so->so_snd);
2298
2299 if (data_to_send->m_flags & M_PKTHDR) {
2300 mbuf_pkthdr_setlen(data_to_send, data_len);
2301 }
2302
2303 error = (*so->so_proto->pr_usrreqs->pru_send)(so,
2304 0,
2305 data_to_send,
2306 NULL,
2307 NULL,
2308 (last_proc != NULL ? last_proc : current_proc()));
2309
2310 if (error && error != EWOULDBLOCK) {
2311 FDLOG(LOG_ERR, fd_cb, "Failed to send queued TCP data using the socket's original protocol: %d", error);
2312 } else {
2313 error = 0;
2314 }
2315 } else if (SOCK_TYPE(so) == SOCK_DGRAM) {
2316 struct sockbuf *sb = &so->so_snd;
2317 MBUFQ_HEAD(send_queue_head) send_queue;
2318 MBUFQ_INIT(&send_queue);
2319
2320 /* Flush the send buffer, moving all records to a temporary queue */
2321 while (sb->sb_mb != NULL) {
2322 mbuf_t record = sb->sb_mb;
2323 mbuf_t m = record;
2324 sb->sb_mb = sb->sb_mb->m_nextpkt;
2325 while (m != NULL) {
2326 sbfree(sb, m);
2327 m = m->m_next;
2328 }
2329 record->m_nextpkt = NULL;
2330 MBUFQ_ENQUEUE(&send_queue, record);
2331 }
2332 SB_EMPTY_FIXUP(sb);
2333
2334 while (!MBUFQ_EMPTY(&send_queue)) {
2335 mbuf_t next_record = MBUFQ_FIRST(&send_queue);
2336 mbuf_t addr = NULL;
2337 mbuf_t control = NULL;
2338 mbuf_t last_control = NULL;
2339 mbuf_t data = NULL;
2340 mbuf_t m = next_record;
2341 struct sockaddr *to_endpoint = NULL;
2342
2343 MBUFQ_DEQUEUE(&send_queue, next_record);
2344
2345 while (m != NULL) {
2346 if (m->m_type == MT_SONAME) {
2347 addr = m;
2348 } else if (m->m_type == MT_CONTROL) {
2349 if (control == NULL) {
2350 control = m;
2351 }
2352 last_control = m;
2353 } else if (m->m_type == MT_DATA) {
2354 data = m;
2355 break;
2356 }
2357 m = m->m_next;
2358 }
2359
2360 if (addr != NULL && !do_connect) {
2361 to_endpoint = flow_divert_get_buffered_target_address(addr);
2362 if (to_endpoint == NULL) {
2363 FDLOG0(LOG_NOTICE, fd_cb, "Failed to get the remote address from the buffer");
2364 }
2365 }
2366
2367 if (data == NULL) {
2368 FDLOG0(LOG_ERR, fd_cb, "Buffered record does not contain any data");
2369 mbuf_freem(next_record);
2370 continue;
2371 }
2372
2373 if (!(data->m_flags & M_PKTHDR)) {
2374 FDLOG0(LOG_ERR, fd_cb, "Buffered data does not have a packet header");
2375 mbuf_freem(next_record);
2376 continue;
2377 }
2378
2379 if (addr != NULL) {
2380 addr->m_next = NULL;
2381 }
2382
2383 if (last_control != NULL) {
2384 last_control->m_next = NULL;
2385 }
2386
2387 error = (*so->so_proto->pr_usrreqs->pru_send)(so,
2388 0,
2389 data,
2390 to_endpoint,
2391 control,
2392 (last_proc != NULL ? last_proc : current_proc()));
2393
2394 if (addr != NULL) {
2395 mbuf_freem(addr);
2396 }
2397
2398 if (error) {
2399 FDLOG(LOG_ERR, fd_cb, "Failed to send queued UDP data using the socket's original protocol: %d", error);
2400 }
2401 }
2402 }
2403 done:
2404 if (last_proc != NULL) {
2405 proc_rele(last_proc);
2406 }
2407
2408 if (error && so != NULL) {
2409 so->so_error = (uint16_t)error;
2410 flow_divert_disconnect_socket(so, do_connect, false);
2411 }
2412 }
2413
2414 static void
flow_divert_scope(struct flow_divert_pcb * fd_cb,int out_if_index,bool derive_new_address)2415 flow_divert_scope(struct flow_divert_pcb *fd_cb, int out_if_index, bool derive_new_address)
2416 {
2417 struct socket *so = NULL;
2418 struct inpcb *inp = NULL;
2419 struct ifnet *current_ifp = NULL;
2420 struct ifnet *new_ifp = NULL;
2421 int error = 0;
2422
2423 so = fd_cb->so;
2424 if (so == NULL) {
2425 return;
2426 }
2427
2428 inp = sotoinpcb(so);
2429
2430 if (out_if_index <= 0) {
2431 return;
2432 }
2433
2434 if (inp->inp_vflag & INP_IPV6) {
2435 current_ifp = inp->in6p_last_outifp;
2436 } else {
2437 current_ifp = inp->inp_last_outifp;
2438 }
2439
2440 if (current_ifp != NULL) {
2441 if (current_ifp->if_index == out_if_index) {
2442 /* No change */
2443 return;
2444 }
2445
2446 /* Scope the socket to the given interface */
2447 error = inp_bindif(inp, out_if_index, &new_ifp);
2448 if (error != 0) {
2449 FDLOG(LOG_ERR, fd_cb, "failed to scope to %d because inp_bindif returned %d", out_if_index, error);
2450 return;
2451 }
2452
2453 if (derive_new_address && fd_cb->original_remote_endpoint != NULL) {
2454 /* Get the appropriate address for the given interface */
2455 if (inp->inp_vflag & INP_IPV6) {
2456 inp->in6p_laddr = sa6_any.sin6_addr;
2457 error = in6_pcbladdr(inp, fd_cb->original_remote_endpoint, &(fd_cb->local_endpoint.sin6.sin6_addr), NULL);
2458 } else {
2459 inp->inp_laddr.s_addr = INADDR_ANY;
2460 error = in_pcbladdr(inp, fd_cb->original_remote_endpoint, &(fd_cb->local_endpoint.sin.sin_addr), IFSCOPE_NONE, NULL, 0);
2461 }
2462
2463 if (error != 0) {
2464 FDLOG(LOG_WARNING, fd_cb, "failed to derive a new local address from %d because in_pcbladdr returned %d", out_if_index, error);
2465 }
2466 }
2467 } else {
2468 ifnet_head_lock_shared();
2469 if (IF_INDEX_IN_RANGE(out_if_index)) {
2470 new_ifp = ifindex2ifnet[out_if_index];
2471 }
2472 ifnet_head_done();
2473 }
2474
2475 /* Update the "last interface" of the socket */
2476 if (new_ifp != NULL) {
2477 if (inp->inp_vflag & INP_IPV6) {
2478 inp->in6p_last_outifp = new_ifp;
2479 } else {
2480 inp->inp_last_outifp = new_ifp;
2481 }
2482
2483 #if SKYWALK
2484 if (NETNS_TOKEN_VALID(&inp->inp_netns_token)) {
2485 netns_set_ifnet(&inp->inp_netns_token, new_ifp);
2486 }
2487 #endif /* SKYWALK */
2488 }
2489 }
2490
2491 static void
flow_divert_handle_connect_result(struct flow_divert_pcb * fd_cb,mbuf_t packet,int offset)2492 flow_divert_handle_connect_result(struct flow_divert_pcb *fd_cb, mbuf_t packet, int offset)
2493 {
2494 uint32_t connect_error = 0;
2495 uint32_t ctl_unit = 0;
2496 int error = 0;
2497 union sockaddr_in_4_6 local_endpoint = {};
2498 union sockaddr_in_4_6 remote_endpoint = {};
2499 int out_if_index = 0;
2500 uint32_t send_window;
2501 uint32_t app_data_length = 0;
2502
2503 memset(&local_endpoint, 0, sizeof(local_endpoint));
2504 memset(&remote_endpoint, 0, sizeof(remote_endpoint));
2505
2506 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_ERROR_CODE, sizeof(connect_error), &connect_error, NULL);
2507 if (error) {
2508 FDLOG(LOG_ERR, fd_cb, "failed to get the connect result: %d", error);
2509 return;
2510 }
2511
2512 connect_error = ntohl(connect_error);
2513 FDLOG(LOG_INFO, fd_cb, "received connect result %u", connect_error);
2514
2515 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_SPACE_AVAILABLE, sizeof(send_window), &send_window, NULL);
2516 if (error) {
2517 FDLOG(LOG_ERR, fd_cb, "failed to get the send window: %d", error);
2518 return;
2519 }
2520
2521 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_CTL_UNIT, sizeof(ctl_unit), &ctl_unit, NULL);
2522 if (error) {
2523 FDLOG0(LOG_INFO, fd_cb, "No control unit provided in the connect result");
2524 }
2525
2526 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_LOCAL_ADDR, sizeof(local_endpoint), &(local_endpoint.sa), NULL);
2527 if (error) {
2528 FDLOG0(LOG_INFO, fd_cb, "No local address provided");
2529 }
2530
2531 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_REMOTE_ADDR, sizeof(remote_endpoint), &(remote_endpoint.sa), NULL);
2532 if (error) {
2533 FDLOG0(LOG_INFO, fd_cb, "No remote address provided");
2534 }
2535
2536 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_OUT_IF_INDEX, sizeof(out_if_index), &out_if_index, NULL);
2537 if (error) {
2538 FDLOG0(LOG_INFO, fd_cb, "No output if index provided");
2539 }
2540
2541 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_APP_DATA, 0, NULL, &app_data_length);
2542 if (error) {
2543 FDLOG0(LOG_INFO, fd_cb, "No application data provided in connect result");
2544 }
2545
2546 error = 0;
2547
2548 FDLOCK(fd_cb);
2549 if (fd_cb->so != NULL) {
2550 struct inpcb *inp = NULL;
2551 struct socket *so = fd_cb->so;
2552 bool local_address_is_valid = false;
2553
2554 socket_lock(so, 1);
2555
2556 if (!(so->so_flags & SOF_FLOW_DIVERT)) {
2557 FDLOG0(LOG_NOTICE, fd_cb, "socket is not attached any more, ignoring connect result");
2558 goto done;
2559 }
2560
2561 if (SOCK_TYPE(so) == SOCK_STREAM && !(so->so_state & SS_ISCONNECTING)) {
2562 FDLOG0(LOG_ERR, fd_cb, "TCP socket is not in the connecting state, ignoring connect result");
2563 goto done;
2564 }
2565
2566 inp = sotoinpcb(so);
2567
2568 if (connect_error || error) {
2569 goto set_socket_state;
2570 }
2571
2572 if (flow_divert_is_sockaddr_valid(SA(&local_endpoint))) {
2573 if (local_endpoint.sa.sa_family == AF_INET) {
2574 local_endpoint.sa.sa_len = sizeof(struct sockaddr_in);
2575 if ((inp->inp_vflag & INP_IPV4) && local_endpoint.sin.sin_addr.s_addr != INADDR_ANY) {
2576 local_address_is_valid = true;
2577 fd_cb->local_endpoint = local_endpoint;
2578 inp->inp_laddr.s_addr = INADDR_ANY;
2579 } else {
2580 fd_cb->local_endpoint.sin.sin_port = local_endpoint.sin.sin_port;
2581 }
2582 } else if (local_endpoint.sa.sa_family == AF_INET6) {
2583 local_endpoint.sa.sa_len = sizeof(struct sockaddr_in6);
2584 if ((inp->inp_vflag & INP_IPV6) && !IN6_IS_ADDR_UNSPECIFIED(&local_endpoint.sin6.sin6_addr)) {
2585 local_address_is_valid = true;
2586 fd_cb->local_endpoint = local_endpoint;
2587 inp->in6p_laddr = sa6_any.sin6_addr;
2588 } else {
2589 fd_cb->local_endpoint.sin6.sin6_port = local_endpoint.sin6.sin6_port;
2590 }
2591 }
2592 }
2593
2594 flow_divert_scope(fd_cb, out_if_index, !local_address_is_valid);
2595 flow_divert_set_local_endpoint(fd_cb, SA(&fd_cb->local_endpoint));
2596
2597 if (flow_divert_is_sockaddr_valid(SA(&remote_endpoint)) && SOCK_TYPE(so) == SOCK_STREAM) {
2598 if (remote_endpoint.sa.sa_family == AF_INET) {
2599 remote_endpoint.sa.sa_len = sizeof(struct sockaddr_in);
2600 } else if (remote_endpoint.sa.sa_family == AF_INET6) {
2601 remote_endpoint.sa.sa_len = sizeof(struct sockaddr_in6);
2602 }
2603 flow_divert_set_remote_endpoint(fd_cb, SA(&remote_endpoint));
2604 }
2605
2606 if (app_data_length > 0) {
2607 uint8_t *app_data = NULL;
2608 app_data = kalloc_data(app_data_length, Z_WAITOK);
2609 if (app_data != NULL) {
2610 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_APP_DATA, app_data_length, app_data, NULL);
2611 if (error == 0) {
2612 FDLOG(LOG_INFO, fd_cb, "Got %u bytes of app data from the connect result", app_data_length);
2613 if (fd_cb->app_data != NULL) {
2614 kfree_data(fd_cb->app_data, fd_cb->app_data_length);
2615 }
2616 fd_cb->app_data = app_data;
2617 fd_cb->app_data_length = app_data_length;
2618 } else {
2619 FDLOG(LOG_ERR, fd_cb, "Failed to copy %u bytes of application data from the connect result packet", app_data_length);
2620 kfree_data(app_data, app_data_length);
2621 }
2622 } else {
2623 FDLOG(LOG_ERR, fd_cb, "Failed to allocate a buffer of size %u to hold the application data from the connect result", app_data_length);
2624 }
2625 }
2626
2627 if (error) {
2628 goto set_socket_state;
2629 }
2630
2631 if (fd_cb->group == NULL) {
2632 error = EINVAL;
2633 goto set_socket_state;
2634 }
2635
2636 ctl_unit = ntohl(ctl_unit);
2637 if (ctl_unit > 0) {
2638 int insert_error = 0;
2639 struct flow_divert_group *grp = NULL;
2640
2641 if (ctl_unit >= GROUP_COUNT_MAX) {
2642 FDLOG(LOG_ERR, fd_cb, "Connect result contains an invalid control unit: %u", ctl_unit);
2643 error = EINVAL;
2644 goto set_socket_state;
2645 }
2646
2647 grp = flow_divert_group_lookup(ctl_unit, fd_cb);
2648 if (grp == NULL) {
2649 error = ECONNRESET;
2650 goto set_socket_state;
2651 }
2652
2653 flow_divert_pcb_remove(fd_cb);
2654 insert_error = flow_divert_pcb_insert(fd_cb, grp);
2655 FDGRP_RELEASE(grp);
2656
2657 if (insert_error != 0) {
2658 error = ECONNRESET;
2659 goto set_socket_state;
2660 }
2661 }
2662
2663 fd_cb->send_window = ntohl(send_window);
2664
2665 set_socket_state:
2666 if (!connect_error && !error) {
2667 FDLOG0(LOG_INFO, fd_cb, "sending connect result");
2668 error = flow_divert_send_connect_result(fd_cb);
2669 }
2670
2671 if (connect_error || error) {
2672 if (connect_error && fd_cb->control_group_unit != fd_cb->policy_control_unit) {
2673 error = flow_divert_try_next_group(fd_cb);
2674 if (error && fd_cb->policy_control_unit == 0) {
2675 flow_divert_disable(fd_cb);
2676 goto done;
2677 } else if (error == 0) {
2678 goto done;
2679 }
2680 }
2681
2682 if (!connect_error) {
2683 flow_divert_update_closed_state(fd_cb, SHUT_RDWR, false, true);
2684 so->so_error = (uint16_t)error;
2685 flow_divert_send_close_if_needed(fd_cb);
2686 } else {
2687 flow_divert_update_closed_state(fd_cb, SHUT_RDWR, true, true);
2688 so->so_error = (uint16_t)connect_error;
2689 }
2690 flow_divert_disconnect_socket(so, !(fd_cb->flags & FLOW_DIVERT_IMPLICIT_CONNECT), false);
2691 } else {
2692 #if NECP
2693 /* Update NECP client with connected five-tuple */
2694 if (!uuid_is_null(inp->necp_client_uuid)) {
2695 socket_unlock(so, 0);
2696 necp_client_assign_from_socket(so->last_pid, inp->necp_client_uuid, inp);
2697 socket_lock(so, 0);
2698 if (!(so->so_flags & SOF_FLOW_DIVERT)) {
2699 /* The socket was closed while it was unlocked */
2700 goto done;
2701 }
2702 }
2703 #endif /* NECP */
2704
2705 flow_divert_send_buffered_data(fd_cb, FALSE);
2706 soisconnected(so);
2707 }
2708
2709 /* We don't need the connect packet any more */
2710 if (fd_cb->connect_packet != NULL) {
2711 mbuf_freem(fd_cb->connect_packet);
2712 fd_cb->connect_packet = NULL;
2713 }
2714
2715 /* We don't need the original remote endpoint any more */
2716 free_sockaddr(fd_cb->original_remote_endpoint);
2717 done:
2718 socket_unlock(so, 1);
2719 }
2720 FDUNLOCK(fd_cb);
2721 }
2722
2723 static void
flow_divert_handle_close(struct flow_divert_pcb * fd_cb,mbuf_t packet,int offset)2724 flow_divert_handle_close(struct flow_divert_pcb *fd_cb, mbuf_t packet, int offset)
2725 {
2726 uint32_t close_error = 0;
2727 int error = 0;
2728 int how = 0;
2729
2730 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_ERROR_CODE, sizeof(close_error), &close_error, NULL);
2731 if (error) {
2732 FDLOG(LOG_ERR, fd_cb, "failed to get the close error: %d", error);
2733 return;
2734 }
2735
2736 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_HOW, sizeof(how), &how, NULL);
2737 if (error) {
2738 FDLOG(LOG_ERR, fd_cb, "failed to get the close how flag: %d", error);
2739 return;
2740 }
2741
2742 how = ntohl(how);
2743
2744 FDLOG(LOG_INFO, fd_cb, "close received, how = %d", how);
2745
2746 FDLOCK(fd_cb);
2747 if (fd_cb->so != NULL) {
2748 bool is_connected = (SOCK_TYPE(fd_cb->so) == SOCK_STREAM || !(fd_cb->flags & FLOW_DIVERT_IMPLICIT_CONNECT));
2749 socket_lock(fd_cb->so, 0);
2750
2751 if (!(fd_cb->so->so_flags & SOF_FLOW_DIVERT)) {
2752 FDLOG0(LOG_NOTICE, fd_cb, "socket is not attached any more, ignoring close from provider");
2753 goto done;
2754 }
2755
2756 fd_cb->so->so_error = (uint16_t)ntohl(close_error);
2757
2758 flow_divert_update_closed_state(fd_cb, how, true, true);
2759
2760 /* Only do this for stream flows because "shutdown by peer" doesn't make sense for datagram flows */
2761 how = flow_divert_tunnel_how_closed(fd_cb);
2762 if (how == SHUT_RDWR) {
2763 flow_divert_disconnect_socket(fd_cb->so, is_connected, true);
2764 } else if (how == SHUT_RD && is_connected) {
2765 socantrcvmore(fd_cb->so);
2766 } else if (how == SHUT_WR && is_connected) {
2767 socantsendmore(fd_cb->so);
2768 }
2769 done:
2770 socket_unlock(fd_cb->so, 0);
2771 }
2772 FDUNLOCK(fd_cb);
2773 }
2774
2775 static mbuf_t
flow_divert_create_control_mbuf(struct flow_divert_pcb * fd_cb)2776 flow_divert_create_control_mbuf(struct flow_divert_pcb *fd_cb)
2777 {
2778 struct inpcb *inp = sotoinpcb(fd_cb->so);
2779 bool need_recvdstaddr = false;
2780 /* Socket flow tracking needs to see the local address */
2781 need_recvdstaddr = SOFLOW_ENABLED(inp->inp_socket);
2782 if ((inp->inp_vflag & INP_IPV4) &&
2783 fd_cb->local_endpoint.sa.sa_family == AF_INET &&
2784 ((inp->inp_flags & INP_RECVDSTADDR) || need_recvdstaddr)) {
2785 return sbcreatecontrol((caddr_t)&(fd_cb->local_endpoint.sin.sin_addr), sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
2786 } else if ((inp->inp_vflag & INP_IPV6) &&
2787 fd_cb->local_endpoint.sa.sa_family == AF_INET6 &&
2788 ((inp->inp_flags & IN6P_PKTINFO) || need_recvdstaddr)) {
2789 struct in6_pktinfo pi6;
2790 memset(&pi6, 0, sizeof(pi6));
2791 pi6.ipi6_addr = fd_cb->local_endpoint.sin6.sin6_addr;
2792
2793 return sbcreatecontrol((caddr_t)&pi6, sizeof(pi6), IPV6_PKTINFO, IPPROTO_IPV6);
2794 }
2795 return NULL;
2796 }
2797
2798 static int
flow_divert_handle_data(struct flow_divert_pcb * fd_cb,mbuf_t packet,size_t offset)2799 flow_divert_handle_data(struct flow_divert_pcb *fd_cb, mbuf_t packet, size_t offset)
2800 {
2801 int error = 0;
2802
2803 FDLOCK(fd_cb);
2804 if (fd_cb->so != NULL) {
2805 mbuf_t data = NULL;
2806 size_t data_size;
2807 struct sockaddr_storage remote_address;
2808 boolean_t got_remote_sa = FALSE;
2809 boolean_t appended = FALSE;
2810 boolean_t append_success = FALSE;
2811
2812 socket_lock(fd_cb->so, 0);
2813
2814 if (!(fd_cb->so->so_flags & SOF_FLOW_DIVERT)) {
2815 FDLOG0(LOG_NOTICE, fd_cb, "socket is not attached any more, ignoring inbound data");
2816 goto done;
2817 }
2818
2819 if (sbspace(&fd_cb->so->so_rcv) == 0) {
2820 error = ENOBUFS;
2821 fd_cb->flags |= FLOW_DIVERT_NOTIFY_ON_RECEIVED;
2822 FDLOG0(LOG_INFO, fd_cb, "Receive buffer is full, will send read notification when app reads some data");
2823 goto done;
2824 }
2825
2826 if (SOCK_TYPE(fd_cb->so) == SOCK_DGRAM) {
2827 uint32_t val_size = 0;
2828
2829 /* check if we got remote address with data */
2830 memset(&remote_address, 0, sizeof(remote_address));
2831 error = flow_divert_packet_get_tlv(packet, (int)offset, FLOW_DIVERT_TLV_REMOTE_ADDR, sizeof(remote_address), &remote_address, &val_size);
2832 if (error || val_size > sizeof(remote_address)) {
2833 FDLOG0(LOG_INFO, fd_cb, "No remote address provided");
2834 error = 0;
2835 } else {
2836 if (remote_address.ss_len > sizeof(remote_address)) {
2837 remote_address.ss_len = sizeof(remote_address);
2838 }
2839 /* validate the address */
2840 if (flow_divert_is_sockaddr_valid((struct sockaddr *)&remote_address)) {
2841 got_remote_sa = TRUE;
2842 } else {
2843 FDLOG0(LOG_INFO, fd_cb, "Remote address is invalid");
2844 }
2845 offset += (sizeof(uint8_t) + sizeof(uint32_t) + val_size);
2846 }
2847 }
2848
2849 data_size = (mbuf_pkthdr_len(packet) - offset);
2850
2851 if (fd_cb->so->so_state & SS_CANTRCVMORE) {
2852 FDLOG(LOG_NOTICE, fd_cb, "app cannot receive any more data, dropping %lu bytes of data", data_size);
2853 goto done;
2854 }
2855
2856 if (SOCK_TYPE(fd_cb->so) != SOCK_STREAM && SOCK_TYPE(fd_cb->so) != SOCK_DGRAM) {
2857 FDLOG(LOG_ERR, fd_cb, "socket has an unsupported type: %d", SOCK_TYPE(fd_cb->so));
2858 goto done;
2859 }
2860
2861 FDLOG(LOG_DEBUG, fd_cb, "received %lu bytes of data", data_size);
2862
2863 error = mbuf_split(packet, offset, MBUF_DONTWAIT, &data);
2864 if (error || data == NULL) {
2865 FDLOG(LOG_ERR, fd_cb, "mbuf_split failed: %d", error);
2866 goto done;
2867 }
2868
2869 if (SOCK_TYPE(fd_cb->so) == SOCK_STREAM) {
2870 appended = (sbappendstream(&fd_cb->so->so_rcv, data) != 0);
2871 append_success = TRUE;
2872 } else {
2873 struct sockaddr *append_sa = NULL;
2874 mbuf_t mctl;
2875
2876 if (got_remote_sa == TRUE) {
2877 error = flow_divert_dup_addr(remote_address.ss_family, (struct sockaddr *)&remote_address, &append_sa);
2878 } else {
2879 if (SOCK_CHECK_DOM(fd_cb->so, AF_INET6)) {
2880 error = in6_mapped_peeraddr(fd_cb->so, &append_sa);
2881 } else {
2882 error = in_getpeeraddr(fd_cb->so, &append_sa);
2883 }
2884 }
2885 if (error) {
2886 FDLOG0(LOG_ERR, fd_cb, "failed to dup the socket address.");
2887 }
2888
2889 mctl = flow_divert_create_control_mbuf(fd_cb);
2890 int append_error = 0;
2891 appended = sbappendaddr(&fd_cb->so->so_rcv, append_sa, data, mctl, &append_error);
2892 if (appended || append_error == 0) {
2893 append_success = TRUE;
2894 } else {
2895 FDLOG(LOG_ERR, fd_cb, "failed to append %lu bytes of data: %d", data_size, append_error);
2896 }
2897
2898 free_sockaddr(append_sa);
2899 }
2900
2901 if (append_success) {
2902 fd_cb->bytes_received += data_size;
2903 flow_divert_add_data_statistics(fd_cb, data_size, FALSE);
2904 }
2905
2906 if (appended) {
2907 sorwakeup(fd_cb->so);
2908 }
2909 done:
2910 socket_unlock(fd_cb->so, 0);
2911 }
2912 FDUNLOCK(fd_cb);
2913
2914 return error;
2915 }
2916
2917 static void
flow_divert_handle_read_notification(struct flow_divert_pcb * fd_cb,mbuf_t packet,int offset)2918 flow_divert_handle_read_notification(struct flow_divert_pcb *fd_cb, mbuf_t packet, int offset)
2919 {
2920 uint32_t read_count = 0;
2921 int error = 0;
2922
2923 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_READ_COUNT, sizeof(read_count), &read_count, NULL);
2924 if (error) {
2925 FDLOG(LOG_ERR, fd_cb, "failed to get the read count: %d", error);
2926 return;
2927 }
2928
2929 FDLOG(LOG_DEBUG, fd_cb, "received a read notification for %u bytes", ntohl(read_count));
2930
2931 FDLOCK(fd_cb);
2932 if (fd_cb->so != NULL) {
2933 socket_lock(fd_cb->so, 0);
2934
2935 if (!(fd_cb->so->so_flags & SOF_FLOW_DIVERT)) {
2936 FDLOG0(LOG_NOTICE, fd_cb, "socket is not attached any more, ignoring read notification");
2937 goto done;
2938 }
2939
2940 fd_cb->send_window += ntohl(read_count);
2941 flow_divert_send_buffered_data(fd_cb, FALSE);
2942 done:
2943 socket_unlock(fd_cb->so, 0);
2944 }
2945 FDUNLOCK(fd_cb);
2946 }
2947
2948 static void
flow_divert_handle_group_init(struct flow_divert_group * group,mbuf_t packet,int offset)2949 flow_divert_handle_group_init(struct flow_divert_group *group, mbuf_t packet, int offset)
2950 {
2951 int error = 0;
2952 uint32_t key_size = 0;
2953 int log_level = 0;
2954 uint32_t flags = 0;
2955 int32_t order = FLOW_DIVERT_ORDER_LAST;
2956
2957 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_TOKEN_KEY, 0, NULL, &key_size);
2958 if (error) {
2959 FDLOG(LOG_ERR, &nil_pcb, "failed to get the key size: %d", error);
2960 return;
2961 }
2962
2963 if (key_size == 0 || key_size > FLOW_DIVERT_MAX_KEY_SIZE) {
2964 FDLOG(LOG_ERR, &nil_pcb, "Invalid key size: %u", key_size);
2965 return;
2966 }
2967
2968 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_LOG_LEVEL, sizeof(log_level), &log_level, NULL);
2969 if (!error) {
2970 nil_pcb.log_level = (uint8_t)log_level;
2971 }
2972
2973 lck_rw_lock_exclusive(&group->lck);
2974
2975 if (group->flags & FLOW_DIVERT_GROUP_FLAG_DEFUNCT) {
2976 FDLOG(LOG_ERR, &nil_pcb, "Skipping (re)initialization of defunct group %u", group->ctl_unit);
2977 lck_rw_done(&group->lck);
2978 return;
2979 }
2980
2981 if (group->token_key != NULL) {
2982 kfree_data(group->token_key, group->token_key_size);
2983 group->token_key = NULL;
2984 }
2985
2986 group->token_key = kalloc_data(key_size, Z_WAITOK);
2987 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_TOKEN_KEY, key_size, group->token_key, NULL);
2988 if (error) {
2989 FDLOG(LOG_ERR, &nil_pcb, "failed to get the token key: %d", error);
2990 kfree_data(group->token_key, key_size);
2991 group->token_key = NULL;
2992 lck_rw_done(&group->lck);
2993 return;
2994 }
2995
2996 group->token_key_size = key_size;
2997
2998 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_FLAGS, sizeof(flags), &flags, NULL);
2999 if (!error) {
3000 group->flags = flags;
3001 }
3002
3003 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_ORDER, sizeof(order), &order, NULL);
3004 if (!error) {
3005 FDLOG(LOG_INFO, &nil_pcb, "group %u order is %u", group->ctl_unit, order);
3006 group->order = order;
3007 }
3008
3009 lck_rw_done(&group->lck);
3010 }
3011
3012 static void
flow_divert_handle_properties_update(struct flow_divert_pcb * fd_cb,mbuf_t packet,int offset)3013 flow_divert_handle_properties_update(struct flow_divert_pcb *fd_cb, mbuf_t packet, int offset)
3014 {
3015 int error = 0;
3016 int out_if_index = 0;
3017 uint32_t app_data_length = 0;
3018
3019 FDLOG0(LOG_INFO, fd_cb, "received a properties update");
3020
3021 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_OUT_IF_INDEX, sizeof(out_if_index), &out_if_index, NULL);
3022 if (error) {
3023 FDLOG0(LOG_INFO, fd_cb, "No output if index provided in properties update");
3024 }
3025
3026 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_APP_DATA, 0, NULL, &app_data_length);
3027 if (error) {
3028 FDLOG0(LOG_INFO, fd_cb, "No application data provided in properties update");
3029 }
3030
3031 FDLOCK(fd_cb);
3032 if (fd_cb->so != NULL) {
3033 socket_lock(fd_cb->so, 0);
3034
3035 if (!(fd_cb->so->so_flags & SOF_FLOW_DIVERT)) {
3036 FDLOG0(LOG_NOTICE, fd_cb, "socket is not attached any more, ignoring properties update");
3037 goto done;
3038 }
3039
3040 if (out_if_index > 0) {
3041 flow_divert_scope(fd_cb, out_if_index, true);
3042 flow_divert_set_local_endpoint(fd_cb, SA(&fd_cb->local_endpoint));
3043 }
3044
3045 if (app_data_length > 0) {
3046 uint8_t *app_data = NULL;
3047 app_data = kalloc_data(app_data_length, Z_WAITOK);
3048 if (app_data != NULL) {
3049 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_APP_DATA, app_data_length, app_data, NULL);
3050 if (error == 0) {
3051 if (fd_cb->app_data != NULL) {
3052 kfree_data(fd_cb->app_data, fd_cb->app_data_length);
3053 }
3054 fd_cb->app_data = app_data;
3055 fd_cb->app_data_length = app_data_length;
3056 } else {
3057 FDLOG(LOG_ERR, fd_cb, "Failed to copy %u bytes of application data from the properties update packet", app_data_length);
3058 kfree_data(app_data, app_data_length);
3059 }
3060 } else {
3061 FDLOG(LOG_ERR, fd_cb, "Failed to allocate a buffer of size %u to hold the application data from the properties update", app_data_length);
3062 }
3063 }
3064 done:
3065 socket_unlock(fd_cb->so, 0);
3066 }
3067 FDUNLOCK(fd_cb);
3068 }
3069
3070 static void
flow_divert_handle_app_map_create(struct flow_divert_group * group,mbuf_t packet,int offset)3071 flow_divert_handle_app_map_create(struct flow_divert_group *group, mbuf_t packet, int offset)
3072 {
3073 size_t bytes_mem_size;
3074 size_t child_maps_mem_size;
3075 size_t nodes_mem_size;
3076 size_t trie_memory_size = 0;
3077 int cursor;
3078 int error = 0;
3079 struct flow_divert_trie new_trie;
3080 int insert_error = 0;
3081 int prefix_count = -1;
3082 int signing_id_count = 0;
3083 size_t bytes_count = 0;
3084 size_t nodes_count = 0;
3085 size_t maps_count = 0;
3086
3087 lck_rw_lock_exclusive(&group->lck);
3088
3089 /* Re-set the current trie */
3090 if (group->signing_id_trie.memory != NULL) {
3091 kfree_data_addr(group->signing_id_trie.memory);
3092 }
3093 memset(&group->signing_id_trie, 0, sizeof(group->signing_id_trie));
3094 group->signing_id_trie.root = NULL_TRIE_IDX;
3095
3096 memset(&new_trie, 0, sizeof(new_trie));
3097
3098 /* Get the number of shared prefixes in the new set of signing ID strings */
3099 error = flow_divert_packet_get_tlv(packet, offset, FLOW_DIVERT_TLV_PREFIX_COUNT, sizeof(prefix_count), &prefix_count, NULL);
3100
3101 if (prefix_count < 0 || error) {
3102 FDLOG(LOG_ERR, &nil_pcb, "Invalid prefix count (%d) or an error occurred while reading the prefix count: %d", prefix_count, error);
3103 lck_rw_done(&group->lck);
3104 return;
3105 }
3106
3107 /* Compute the number of signing IDs and the total amount of bytes needed to store them */
3108 for (cursor = flow_divert_packet_find_tlv(packet, offset, FLOW_DIVERT_TLV_SIGNING_ID, &error, 0);
3109 cursor >= 0;
3110 cursor = flow_divert_packet_find_tlv(packet, cursor, FLOW_DIVERT_TLV_SIGNING_ID, &error, 1)) {
3111 uint32_t sid_size = 0;
3112 error = flow_divert_packet_get_tlv(packet, cursor, FLOW_DIVERT_TLV_SIGNING_ID, 0, NULL, &sid_size);
3113 if (error || sid_size == 0) {
3114 FDLOG(LOG_ERR, &nil_pcb, "Failed to get the length of the signing identifier at offset %d: %d", cursor, error);
3115 signing_id_count = 0;
3116 break;
3117 }
3118 if (os_add_overflow(bytes_count, sid_size, &bytes_count)) {
3119 FDLOG0(LOG_ERR, &nil_pcb, "Overflow while incrementing number of bytes");
3120 signing_id_count = 0;
3121 break;
3122 }
3123 signing_id_count++;
3124 }
3125
3126 if (signing_id_count == 0) {
3127 lck_rw_done(&group->lck);
3128 FDLOG0(LOG_NOTICE, &nil_pcb, "No signing identifiers");
3129 return;
3130 }
3131
3132 if (os_add3_overflow(prefix_count, signing_id_count, 1, &nodes_count)) { /* + 1 for the root node */
3133 lck_rw_done(&group->lck);
3134 FDLOG0(LOG_ERR, &nil_pcb, "Overflow while computing the number of nodes");
3135 return;
3136 }
3137
3138 if (os_add_overflow(prefix_count, 1, &maps_count)) { /* + 1 for the root node */
3139 lck_rw_done(&group->lck);
3140 FDLOG0(LOG_ERR, &nil_pcb, "Overflow while computing the number of maps");
3141 return;
3142 }
3143
3144 if (bytes_count > UINT16_MAX || nodes_count > UINT16_MAX || maps_count > UINT16_MAX) {
3145 lck_rw_done(&group->lck);
3146 FDLOG(LOG_NOTICE, &nil_pcb, "Invalid bytes count (%lu), nodes count (%lu) or maps count (%lu)", bytes_count, nodes_count, maps_count);
3147 return;
3148 }
3149
3150 FDLOG(LOG_INFO, &nil_pcb, "Nodes count = %lu, child maps count = %lu, bytes_count = %lu",
3151 nodes_count, maps_count, bytes_count);
3152
3153 if (os_mul_overflow(sizeof(*new_trie.nodes), (size_t)nodes_count, &nodes_mem_size) ||
3154 os_mul3_overflow(sizeof(*new_trie.child_maps), CHILD_MAP_SIZE, (size_t)maps_count, &child_maps_mem_size) ||
3155 os_mul_overflow(sizeof(*new_trie.bytes), (size_t)bytes_count, &bytes_mem_size) ||
3156 os_add3_overflow(nodes_mem_size, child_maps_mem_size, bytes_mem_size, &trie_memory_size)) {
3157 FDLOG0(LOG_ERR, &nil_pcb, "Overflow while computing trie memory sizes");
3158 lck_rw_done(&group->lck);
3159 return;
3160 }
3161
3162 if (trie_memory_size > FLOW_DIVERT_MAX_TRIE_MEMORY) {
3163 FDLOG(LOG_ERR, &nil_pcb, "Trie memory size (%lu) is too big (maximum is %u)", trie_memory_size, FLOW_DIVERT_MAX_TRIE_MEMORY);
3164 lck_rw_done(&group->lck);
3165 return;
3166 }
3167
3168 new_trie.memory = kalloc_data(trie_memory_size, Z_WAITOK);
3169 if (new_trie.memory == NULL) {
3170 FDLOG(LOG_ERR, &nil_pcb, "Failed to allocate %lu bytes of memory for the signing ID trie",
3171 nodes_mem_size + child_maps_mem_size + bytes_mem_size);
3172 lck_rw_done(&group->lck);
3173 return;
3174 }
3175
3176 new_trie.bytes_count = (uint16_t)bytes_count;
3177 new_trie.nodes_count = (uint16_t)nodes_count;
3178 new_trie.child_maps_count = (uint16_t)maps_count;
3179
3180 /* Initialize the free lists */
3181 new_trie.nodes = (struct flow_divert_trie_node *)new_trie.memory;
3182 new_trie.nodes_free_next = 0;
3183 memset(new_trie.nodes, 0, nodes_mem_size);
3184
3185 new_trie.child_maps = (uint16_t *)(void *)((uint8_t *)new_trie.memory + nodes_mem_size);
3186 new_trie.child_maps_free_next = 0;
3187 memset(new_trie.child_maps, 0xff, child_maps_mem_size);
3188
3189 new_trie.bytes = (uint8_t *)(void *)((uint8_t *)new_trie.memory + nodes_mem_size + child_maps_mem_size);
3190 new_trie.bytes_free_next = 0;
3191 memset(new_trie.bytes, 0, bytes_mem_size);
3192
3193 /* The root is an empty node */
3194 new_trie.root = trie_node_alloc(&new_trie);
3195
3196 /* Add each signing ID to the trie */
3197 for (cursor = flow_divert_packet_find_tlv(packet, offset, FLOW_DIVERT_TLV_SIGNING_ID, &error, 0);
3198 cursor >= 0;
3199 cursor = flow_divert_packet_find_tlv(packet, cursor, FLOW_DIVERT_TLV_SIGNING_ID, &error, 1)) {
3200 uint32_t sid_size = 0;
3201 error = flow_divert_packet_get_tlv(packet, cursor, FLOW_DIVERT_TLV_SIGNING_ID, 0, NULL, &sid_size);
3202 if (error || sid_size == 0) {
3203 FDLOG(LOG_ERR, &nil_pcb, "Failed to get the length of the signing identifier at offset %d while building: %d", cursor, error);
3204 insert_error = EINVAL;
3205 break;
3206 }
3207 if (sid_size <= UINT16_MAX && new_trie.bytes_free_next + (uint16_t)sid_size <= new_trie.bytes_count) {
3208 uint16_t new_node_idx;
3209 error = flow_divert_packet_get_tlv(packet, cursor, FLOW_DIVERT_TLV_SIGNING_ID, sid_size, &TRIE_BYTE(&new_trie, new_trie.bytes_free_next), NULL);
3210 if (error) {
3211 FDLOG(LOG_ERR, &nil_pcb, "Failed to read the signing identifier at offset %d: %d", cursor, error);
3212 insert_error = EINVAL;
3213 break;
3214 }
3215 new_node_idx = flow_divert_trie_insert(&new_trie, new_trie.bytes_free_next, sid_size);
3216 if (new_node_idx == NULL_TRIE_IDX) {
3217 insert_error = EINVAL;
3218 break;
3219 }
3220 } else {
3221 FDLOG0(LOG_ERR, &nil_pcb, "No place to put signing ID for insertion");
3222 insert_error = ENOBUFS;
3223 break;
3224 }
3225 }
3226
3227 if (!insert_error) {
3228 group->signing_id_trie = new_trie;
3229 } else {
3230 kfree_data(new_trie.memory, trie_memory_size);
3231 }
3232
3233 lck_rw_done(&group->lck);
3234 }
3235
3236 static void
flow_divert_handle_flow_states_request(struct flow_divert_group * group)3237 flow_divert_handle_flow_states_request(struct flow_divert_group *group)
3238 {
3239 struct flow_divert_pcb *fd_cb;
3240 mbuf_t packet = NULL;
3241 SLIST_HEAD(, flow_divert_pcb) tmp_list;
3242 int error = 0;
3243 uint32_t ctl_unit = 0;
3244
3245 SLIST_INIT(&tmp_list);
3246
3247 error = flow_divert_packet_init(&nil_pcb, FLOW_DIVERT_PKT_FLOW_STATES, &packet);
3248 if (error || packet == NULL) {
3249 FDLOG(LOG_ERR, &nil_pcb, "flow_divert_packet_init failed: %d, cannot send flow states", error);
3250 return;
3251 }
3252
3253 lck_rw_lock_shared(&group->lck);
3254
3255 if (!MBUFQ_EMPTY(&group->send_queue)) {
3256 FDLOG0(LOG_WARNING, &nil_pcb, "flow_divert_handle_flow_states_request: group send queue is not empty");
3257 }
3258
3259 ctl_unit = group->ctl_unit;
3260
3261 RB_FOREACH(fd_cb, fd_pcb_tree, &group->pcb_tree) {
3262 FDRETAIN(fd_cb);
3263 SLIST_INSERT_HEAD(&tmp_list, fd_cb, tmp_list_entry);
3264 }
3265
3266 lck_rw_done(&group->lck);
3267
3268 SLIST_FOREACH(fd_cb, &tmp_list, tmp_list_entry) {
3269 FDLOCK(fd_cb);
3270 if (fd_cb->so != NULL) {
3271 struct flow_divert_flow_state state = {};
3272 socket_lock(fd_cb->so, 0);
3273
3274 state.conn_id = fd_cb->hash;
3275 state.bytes_written_by_app = fd_cb->bytes_written_by_app;
3276 state.bytes_sent = fd_cb->bytes_sent;
3277 state.bytes_received = fd_cb->bytes_received;
3278 state.send_window = fd_cb->send_window;
3279 state.send_buffer_bytes = fd_cb->so->so_snd.sb_cc;
3280
3281 error = flow_divert_packet_append_tlv(packet, FLOW_DIVERT_TLV_FLOW_STATE, sizeof(state), &state);
3282 if (error) {
3283 FDLOG(LOG_ERR, fd_cb, "Failed to add a flow state: %d", error);
3284 }
3285
3286 socket_unlock(fd_cb->so, 0);
3287 }
3288 FDUNLOCK(fd_cb);
3289 FDRELEASE(fd_cb);
3290 }
3291
3292 error = ctl_enqueuembuf(g_flow_divert_kctl_ref, ctl_unit, packet, CTL_DATA_EOR);
3293 if (error) {
3294 FDLOG(LOG_NOTICE, &nil_pcb, "flow_divert_handle_flow_states_request: ctl_enqueuembuf returned an error: %d", error);
3295 mbuf_freem(packet);
3296 }
3297 }
3298
3299 static int
flow_divert_input(mbuf_t packet,struct flow_divert_group * group)3300 flow_divert_input(mbuf_t packet, struct flow_divert_group *group)
3301 {
3302 struct flow_divert_packet_header hdr;
3303 int error = 0;
3304 struct flow_divert_pcb *fd_cb;
3305
3306 if (mbuf_pkthdr_len(packet) < sizeof(hdr)) {
3307 FDLOG(LOG_ERR, &nil_pcb, "got a bad packet, length (%lu) < sizeof hdr (%lu)", mbuf_pkthdr_len(packet), sizeof(hdr));
3308 error = EINVAL;
3309 goto done;
3310 }
3311
3312 error = mbuf_copydata(packet, 0, sizeof(hdr), &hdr);
3313 if (error) {
3314 FDLOG(LOG_ERR, &nil_pcb, "mbuf_copydata failed for the header: %d", error);
3315 error = ENOBUFS;
3316 goto done;
3317 }
3318
3319 hdr.conn_id = ntohl(hdr.conn_id);
3320
3321 if (hdr.conn_id == 0) {
3322 switch (hdr.packet_type) {
3323 case FLOW_DIVERT_PKT_GROUP_INIT:
3324 flow_divert_handle_group_init(group, packet, sizeof(hdr));
3325 break;
3326 case FLOW_DIVERT_PKT_APP_MAP_CREATE:
3327 flow_divert_handle_app_map_create(group, packet, sizeof(hdr));
3328 break;
3329 case FLOW_DIVERT_PKT_FLOW_STATES_REQUEST:
3330 flow_divert_handle_flow_states_request(group);
3331 break;
3332 default:
3333 FDLOG(LOG_WARNING, &nil_pcb, "got an unknown message type: %d", hdr.packet_type);
3334 break;
3335 }
3336 goto done;
3337 }
3338
3339 fd_cb = flow_divert_pcb_lookup(hdr.conn_id, group); /* This retains the PCB */
3340 if (fd_cb == NULL) {
3341 if (hdr.packet_type != FLOW_DIVERT_PKT_CLOSE && hdr.packet_type != FLOW_DIVERT_PKT_READ_NOTIFY) {
3342 FDLOG(LOG_NOTICE, &nil_pcb, "got a %s message from group %d for an unknown pcb: %u", flow_divert_packet_type2str(hdr.packet_type), group->ctl_unit, hdr.conn_id);
3343 }
3344 goto done;
3345 }
3346
3347 switch (hdr.packet_type) {
3348 case FLOW_DIVERT_PKT_CONNECT_RESULT:
3349 flow_divert_handle_connect_result(fd_cb, packet, sizeof(hdr));
3350 break;
3351 case FLOW_DIVERT_PKT_CLOSE:
3352 flow_divert_handle_close(fd_cb, packet, sizeof(hdr));
3353 break;
3354 case FLOW_DIVERT_PKT_DATA:
3355 error = flow_divert_handle_data(fd_cb, packet, sizeof(hdr));
3356 break;
3357 case FLOW_DIVERT_PKT_READ_NOTIFY:
3358 flow_divert_handle_read_notification(fd_cb, packet, sizeof(hdr));
3359 break;
3360 case FLOW_DIVERT_PKT_PROPERTIES_UPDATE:
3361 flow_divert_handle_properties_update(fd_cb, packet, sizeof(hdr));
3362 break;
3363 default:
3364 FDLOG(LOG_WARNING, fd_cb, "got an unknown message type: %d", hdr.packet_type);
3365 break;
3366 }
3367
3368 FDRELEASE(fd_cb);
3369
3370 done:
3371 mbuf_freem(packet);
3372 return error;
3373 }
3374
3375 static void
flow_divert_close_all(struct flow_divert_group * group)3376 flow_divert_close_all(struct flow_divert_group *group)
3377 {
3378 struct flow_divert_pcb *fd_cb;
3379 SLIST_HEAD(, flow_divert_pcb) tmp_list;
3380
3381 SLIST_INIT(&tmp_list);
3382
3383 lck_rw_lock_exclusive(&group->lck);
3384
3385 MBUFQ_DRAIN(&group->send_queue);
3386
3387 RB_FOREACH(fd_cb, fd_pcb_tree, &group->pcb_tree) {
3388 FDRETAIN(fd_cb);
3389 SLIST_INSERT_HEAD(&tmp_list, fd_cb, tmp_list_entry);
3390 }
3391
3392 group->flags |= FLOW_DIVERT_GROUP_FLAG_DEFUNCT;
3393
3394 lck_rw_done(&group->lck);
3395
3396 while (!SLIST_EMPTY(&tmp_list)) {
3397 fd_cb = SLIST_FIRST(&tmp_list);
3398 FDLOCK(fd_cb);
3399 SLIST_REMOVE_HEAD(&tmp_list, tmp_list_entry);
3400 if (fd_cb->so != NULL) {
3401 socket_lock(fd_cb->so, 0);
3402 flow_divert_pcb_remove(fd_cb);
3403 flow_divert_update_closed_state(fd_cb, SHUT_RDWR, true, true);
3404 fd_cb->so->so_error = ECONNABORTED;
3405 flow_divert_disconnect_socket(fd_cb->so, !(fd_cb->flags & FLOW_DIVERT_IMPLICIT_CONNECT), false);
3406 socket_unlock(fd_cb->so, 0);
3407 }
3408 FDUNLOCK(fd_cb);
3409 FDRELEASE(fd_cb);
3410 }
3411 }
3412
3413 void
flow_divert_detach(struct socket * so)3414 flow_divert_detach(struct socket *so)
3415 {
3416 struct flow_divert_pcb *fd_cb = so->so_fd_pcb;
3417
3418 if (!SO_IS_DIVERTED(so)) {
3419 return;
3420 }
3421
3422 so->so_flags &= ~SOF_FLOW_DIVERT;
3423 so->so_fd_pcb = NULL;
3424
3425 FDLOG(LOG_INFO, fd_cb, "Detaching, ref count = %d", fd_cb->ref_count);
3426
3427 if (fd_cb->group != NULL) {
3428 /* Last-ditch effort to send any buffered data */
3429 flow_divert_send_buffered_data(fd_cb, TRUE);
3430
3431 flow_divert_update_closed_state(fd_cb, SHUT_RDWR, false, true);
3432 flow_divert_send_close_if_needed(fd_cb);
3433 /* Remove from the group */
3434 flow_divert_pcb_remove(fd_cb);
3435 }
3436
3437 socket_unlock(so, 0);
3438 FDLOCK(fd_cb);
3439 fd_cb->so = NULL;
3440 FDUNLOCK(fd_cb);
3441 socket_lock(so, 0);
3442
3443 FDRELEASE(fd_cb); /* Release the socket's reference */
3444 }
3445
3446 static int
flow_divert_close(struct socket * so)3447 flow_divert_close(struct socket *so)
3448 {
3449 struct flow_divert_pcb *fd_cb = so->so_fd_pcb;
3450
3451 if (!SO_IS_DIVERTED(so)) {
3452 return EINVAL;
3453 }
3454
3455 FDLOG0(LOG_INFO, fd_cb, "Closing");
3456
3457 if (SOCK_TYPE(so) == SOCK_STREAM) {
3458 soisdisconnecting(so);
3459 sbflush(&so->so_rcv);
3460 }
3461
3462 flow_divert_send_buffered_data(fd_cb, TRUE);
3463 flow_divert_update_closed_state(fd_cb, SHUT_RDWR, false, true);
3464 flow_divert_send_close_if_needed(fd_cb);
3465
3466 /* Remove from the group */
3467 flow_divert_pcb_remove(fd_cb);
3468
3469 return 0;
3470 }
3471
3472 static int
flow_divert_disconnectx(struct socket * so,sae_associd_t aid,sae_connid_t cid __unused)3473 flow_divert_disconnectx(struct socket *so, sae_associd_t aid,
3474 sae_connid_t cid __unused)
3475 {
3476 if (aid != SAE_ASSOCID_ANY && aid != SAE_ASSOCID_ALL) {
3477 return EINVAL;
3478 }
3479
3480 return flow_divert_close(so);
3481 }
3482
3483 static int
flow_divert_shutdown(struct socket * so)3484 flow_divert_shutdown(struct socket *so)
3485 {
3486 struct flow_divert_pcb *fd_cb = so->so_fd_pcb;
3487
3488 if (!SO_IS_DIVERTED(so)) {
3489 return EINVAL;
3490 }
3491
3492 FDLOG0(LOG_INFO, fd_cb, "Can't send more");
3493
3494 socantsendmore(so);
3495
3496 flow_divert_update_closed_state(fd_cb, SHUT_WR, false, true);
3497 flow_divert_send_close_if_needed(fd_cb);
3498
3499 return 0;
3500 }
3501
3502 static int
flow_divert_rcvd(struct socket * so,int flags __unused)3503 flow_divert_rcvd(struct socket *so, int flags __unused)
3504 {
3505 struct flow_divert_pcb *fd_cb = so->so_fd_pcb;
3506 int space = 0;
3507
3508 if (!SO_IS_DIVERTED(so)) {
3509 return EINVAL;
3510 }
3511
3512 space = sbspace(&so->so_rcv);
3513 FDLOG(LOG_DEBUG, fd_cb, "app read bytes, space = %d", space);
3514 if ((fd_cb->flags & FLOW_DIVERT_NOTIFY_ON_RECEIVED) &&
3515 (space > 0) &&
3516 flow_divert_send_read_notification(fd_cb) == 0) {
3517 FDLOG0(LOG_INFO, fd_cb, "Sent a read notification");
3518 fd_cb->flags &= ~FLOW_DIVERT_NOTIFY_ON_RECEIVED;
3519 }
3520
3521 return 0;
3522 }
3523
3524 static int
flow_divert_append_target_endpoint_tlv(mbuf_t connect_packet,struct sockaddr * toaddr)3525 flow_divert_append_target_endpoint_tlv(mbuf_t connect_packet, struct sockaddr *toaddr)
3526 {
3527 int error = 0;
3528 int port = 0;
3529
3530 if (!flow_divert_is_sockaddr_valid(toaddr)) {
3531 FDLOG(LOG_ERR, &nil_pcb, "Invalid target address, family = %u, length = %u", toaddr->sa_family, toaddr->sa_len);
3532 error = EINVAL;
3533 goto done;
3534 }
3535
3536 error = flow_divert_packet_append_tlv(connect_packet, FLOW_DIVERT_TLV_TARGET_ADDRESS, toaddr->sa_len, toaddr);
3537 if (error) {
3538 goto done;
3539 }
3540
3541 if (toaddr->sa_family == AF_INET) {
3542 port = ntohs((satosin(toaddr))->sin_port);
3543 } else {
3544 port = ntohs((satosin6(toaddr))->sin6_port);
3545 }
3546
3547 error = flow_divert_packet_append_tlv(connect_packet, FLOW_DIVERT_TLV_TARGET_PORT, sizeof(port), &port);
3548 if (error) {
3549 goto done;
3550 }
3551
3552 done:
3553 return error;
3554 }
3555
3556 struct sockaddr *
flow_divert_get_buffered_target_address(mbuf_t buffer)3557 flow_divert_get_buffered_target_address(mbuf_t buffer)
3558 {
3559 if (buffer != NULL && buffer->m_type == MT_SONAME) {
3560 struct sockaddr *toaddr = mtod(buffer, struct sockaddr *);
3561 if (toaddr != NULL && flow_divert_is_sockaddr_valid(toaddr)) {
3562 return toaddr;
3563 }
3564 }
3565 return NULL;
3566 }
3567
3568 static boolean_t
flow_divert_is_sockaddr_valid(struct sockaddr * addr)3569 flow_divert_is_sockaddr_valid(struct sockaddr *addr)
3570 {
3571 switch (addr->sa_family) {
3572 case AF_INET:
3573 if (addr->sa_len < sizeof(struct sockaddr_in)) {
3574 return FALSE;
3575 }
3576 break;
3577 case AF_INET6:
3578 if (addr->sa_len < sizeof(struct sockaddr_in6)) {
3579 return FALSE;
3580 }
3581 break;
3582 default:
3583 return FALSE;
3584 }
3585 return TRUE;
3586 }
3587
3588 static errno_t
flow_divert_dup_addr(sa_family_t family,struct sockaddr * addr,struct sockaddr ** dup)3589 flow_divert_dup_addr(sa_family_t family, struct sockaddr *addr,
3590 struct sockaddr **dup)
3591 {
3592 int error = 0;
3593 struct sockaddr *result;
3594 struct sockaddr_storage ss;
3595
3596 if (addr != NULL) {
3597 result = addr;
3598 } else {
3599 memset(&ss, 0, sizeof(ss));
3600 ss.ss_family = family;
3601 if (ss.ss_family == AF_INET) {
3602 ss.ss_len = sizeof(struct sockaddr_in);
3603 } else if (ss.ss_family == AF_INET6) {
3604 ss.ss_len = sizeof(struct sockaddr_in6);
3605 } else {
3606 error = EINVAL;
3607 }
3608 result = (struct sockaddr *)&ss;
3609 }
3610
3611 if (!error) {
3612 *dup = dup_sockaddr(result, 1);
3613 if (*dup == NULL) {
3614 error = ENOBUFS;
3615 }
3616 }
3617
3618 return error;
3619 }
3620
3621 static void
flow_divert_disconnect_socket(struct socket * so,bool is_connected,bool delay_if_needed)3622 flow_divert_disconnect_socket(struct socket *so, bool is_connected, bool delay_if_needed)
3623 {
3624 if (SOCK_TYPE(so) == SOCK_STREAM || is_connected) {
3625 soisdisconnected(so);
3626 }
3627 if (SOCK_TYPE(so) == SOCK_DGRAM) {
3628 struct inpcb *inp = sotoinpcb(so);
3629 if (inp != NULL && !(so->so_flags & SOF_PCBCLEARING)) {
3630 /*
3631 * Let NetworkStatistics know this PCB is going away
3632 * before we detach it.
3633 */
3634 if (nstat_collect && (SOCK_PROTO(so) == IPPROTO_TCP || SOCK_PROTO(so) == IPPROTO_UDP)) {
3635 nstat_pcb_detach(inp);
3636 }
3637
3638 if (SOCK_DOM(so) == PF_INET6) {
3639 ROUTE_RELEASE(&inp->in6p_route);
3640 } else {
3641 ROUTE_RELEASE(&inp->inp_route);
3642 }
3643 if (delay_if_needed) {
3644 (void) cfil_sock_is_dead(so);
3645 } else {
3646 inp->inp_state = INPCB_STATE_DEAD;
3647 inpcb_gc_sched(inp->inp_pcbinfo, INPCB_TIMER_FAST);
3648 }
3649 /* makes sure we're not called twice from so_close */
3650 so->so_flags |= SOF_PCBCLEARING;
3651 }
3652 }
3653 }
3654
3655 static errno_t
flow_divert_ctloutput(struct socket * so,struct sockopt * sopt)3656 flow_divert_ctloutput(struct socket *so, struct sockopt *sopt)
3657 {
3658 struct flow_divert_pcb *fd_cb = so->so_fd_pcb;
3659
3660 if (!SO_IS_DIVERTED(so)) {
3661 return EINVAL;
3662 }
3663
3664 if (sopt->sopt_name == SO_TRAFFIC_CLASS) {
3665 if (sopt->sopt_dir == SOPT_SET && fd_cb->flags & FLOW_DIVERT_CONNECT_STARTED) {
3666 flow_divert_send_traffic_class_update(fd_cb, so->so_traffic_class);
3667 }
3668 }
3669
3670 if (SOCK_DOM(so) == PF_INET) {
3671 return g_tcp_protosw->pr_ctloutput(so, sopt);
3672 } else if (SOCK_DOM(so) == PF_INET6) {
3673 return g_tcp6_protosw->pr_ctloutput(so, sopt);
3674 }
3675 return 0;
3676 }
3677
3678 static errno_t
flow_divert_connect_out_internal(struct socket * so,struct sockaddr * to,proc_t p,bool implicit)3679 flow_divert_connect_out_internal(struct socket *so, struct sockaddr *to, proc_t p, bool implicit)
3680 {
3681 struct flow_divert_pcb *fd_cb = so->so_fd_pcb;
3682 int error = 0;
3683 struct inpcb *inp = sotoinpcb(so);
3684 struct sockaddr_in *sinp;
3685 mbuf_t connect_packet = NULL;
3686 int do_send = 1;
3687
3688 if (!SO_IS_DIVERTED(so)) {
3689 return EINVAL;
3690 }
3691
3692 if (fd_cb->group == NULL) {
3693 error = ENETUNREACH;
3694 goto done;
3695 }
3696
3697 if (inp == NULL) {
3698 error = EINVAL;
3699 goto done;
3700 } else if (inp->inp_state == INPCB_STATE_DEAD) {
3701 if (so->so_error) {
3702 error = so->so_error;
3703 so->so_error = 0;
3704 } else {
3705 error = EINVAL;
3706 }
3707 goto done;
3708 }
3709
3710 if (fd_cb->flags & FLOW_DIVERT_CONNECT_STARTED) {
3711 error = EALREADY;
3712 goto done;
3713 }
3714
3715 FDLOG0(LOG_INFO, fd_cb, "Connecting");
3716
3717 if (fd_cb->connect_packet == NULL) {
3718 struct sockaddr_in sin = {};
3719 struct ifnet *ifp = NULL;
3720
3721 if (to == NULL) {
3722 FDLOG0(LOG_ERR, fd_cb, "No destination address available when creating connect packet");
3723 error = EINVAL;
3724 goto done;
3725 }
3726
3727 if (!flow_divert_is_sockaddr_valid(to)) {
3728 FDLOG0(LOG_ERR, fd_cb, "Destination address is not valid when creating connect packet");
3729 error = EINVAL;
3730 goto done;
3731 }
3732
3733 fd_cb->original_remote_endpoint = dup_sockaddr(to, 0);
3734 if (fd_cb->original_remote_endpoint == NULL) {
3735 FDLOG0(LOG_ERR, fd_cb, "Failed to dup the remote endpoint");
3736 error = ENOMEM;
3737 goto done;
3738 }
3739 fd_cb->original_vflag = inp->inp_vflag;
3740 fd_cb->original_last_outifp = inp->inp_last_outifp;
3741 fd_cb->original_last_outifp6 = inp->in6p_last_outifp;
3742
3743 sinp = (struct sockaddr_in *)(void *)to;
3744 if (sinp->sin_family == AF_INET && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
3745 error = EAFNOSUPPORT;
3746 goto done;
3747 }
3748
3749 if (to->sa_family == AF_INET6 && !(inp->inp_flags & IN6P_IPV6_V6ONLY)) {
3750 struct sockaddr_in6 sin6 = {};
3751 sin6.sin6_family = AF_INET6;
3752 sin6.sin6_len = sizeof(struct sockaddr_in6);
3753 sin6.sin6_port = satosin6(to)->sin6_port;
3754 sin6.sin6_addr = satosin6(to)->sin6_addr;
3755 if (IN6_IS_ADDR_V4MAPPED(&(sin6.sin6_addr))) {
3756 in6_sin6_2_sin(&sin, &sin6);
3757 to = (struct sockaddr *)&sin;
3758 }
3759 }
3760
3761 if (to->sa_family == AF_INET6) {
3762 struct sockaddr_in6 *to6 = satosin6(to);
3763
3764 inp->inp_vflag &= ~INP_IPV4;
3765 inp->inp_vflag |= INP_IPV6;
3766 fd_cb->local_endpoint.sin6.sin6_len = sizeof(struct sockaddr_in6);
3767 fd_cb->local_endpoint.sin6.sin6_family = AF_INET6;
3768 fd_cb->local_endpoint.sin6.sin6_port = inp->inp_lport;
3769 error = in6_pcbladdr(inp, to, &(fd_cb->local_endpoint.sin6.sin6_addr), &ifp);
3770 if (error) {
3771 FDLOG(LOG_WARNING, fd_cb, "failed to get a local IPv6 address: %d", error);
3772 if (!(fd_cb->flags & FLOW_DIVERT_FLOW_IS_TRANSPARENT) || IN6_IS_ADDR_UNSPECIFIED(&(satosin6(to)->sin6_addr))) {
3773 error = 0;
3774 } else {
3775 goto done;
3776 }
3777 }
3778 if (ifp != NULL) {
3779 inp->in6p_last_outifp = ifp;
3780 ifnet_release(ifp);
3781 }
3782
3783 if (IN6_IS_SCOPE_EMBED(&(fd_cb->local_endpoint.sin6.sin6_addr)) &&
3784 in6_embedded_scope &&
3785 fd_cb->local_endpoint.sin6.sin6_addr.s6_addr16[1] != 0) {
3786 fd_cb->local_endpoint.sin6.sin6_scope_id = ntohs(fd_cb->local_endpoint.sin6.sin6_addr.s6_addr16[1]);
3787 fd_cb->local_endpoint.sin6.sin6_addr.s6_addr16[1] = 0;
3788 }
3789
3790 if (IN6_IS_SCOPE_EMBED(&(to6->sin6_addr)) &&
3791 in6_embedded_scope &&
3792 to6->sin6_addr.s6_addr16[1] != 0) {
3793 to6->sin6_scope_id = ntohs(to6->sin6_addr.s6_addr16[1]);
3794 to6->sin6_addr.s6_addr16[1] = 0;
3795 }
3796 } else if (to->sa_family == AF_INET) {
3797 inp->inp_vflag |= INP_IPV4;
3798 inp->inp_vflag &= ~INP_IPV6;
3799 fd_cb->local_endpoint.sin.sin_len = sizeof(struct sockaddr_in);
3800 fd_cb->local_endpoint.sin.sin_family = AF_INET;
3801 fd_cb->local_endpoint.sin.sin_port = inp->inp_lport;
3802 error = in_pcbladdr(inp, to, &(fd_cb->local_endpoint.sin.sin_addr), IFSCOPE_NONE, &ifp, 0);
3803 if (error) {
3804 FDLOG(LOG_WARNING, fd_cb, "failed to get a local IPv4 address: %d", error);
3805 if (!(fd_cb->flags & FLOW_DIVERT_FLOW_IS_TRANSPARENT) || satosin(to)->sin_addr.s_addr == INADDR_ANY) {
3806 error = 0;
3807 } else {
3808 goto done;
3809 }
3810 }
3811 if (ifp != NULL) {
3812 inp->inp_last_outifp = ifp;
3813 ifnet_release(ifp);
3814 }
3815 } else {
3816 FDLOG(LOG_WARNING, fd_cb, "target address has an unsupported family: %d", to->sa_family);
3817 }
3818
3819 error = flow_divert_check_no_cellular(fd_cb) ||
3820 flow_divert_check_no_expensive(fd_cb) ||
3821 flow_divert_check_no_constrained(fd_cb);
3822 if (error) {
3823 goto done;
3824 }
3825
3826 if (SOCK_TYPE(so) == SOCK_STREAM || /* TCP or */
3827 !implicit || /* connect() was called or */
3828 ((inp->inp_vflag & INP_IPV6) && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) || /* local address is not un-specified */
3829 ((inp->inp_vflag & INP_IPV4) && inp->inp_laddr.s_addr != INADDR_ANY)) {
3830 fd_cb->flags |= FLOW_DIVERT_SHOULD_SET_LOCAL_ADDR;
3831 }
3832
3833 error = flow_divert_create_connect_packet(fd_cb, to, so, p, &connect_packet);
3834 if (error) {
3835 goto done;
3836 }
3837
3838 if (!implicit || SOCK_TYPE(so) == SOCK_STREAM) {
3839 flow_divert_set_remote_endpoint(fd_cb, to);
3840 flow_divert_set_local_endpoint(fd_cb, SA(&fd_cb->local_endpoint));
3841 }
3842
3843 if (implicit) {
3844 fd_cb->flags |= FLOW_DIVERT_IMPLICIT_CONNECT;
3845 }
3846
3847 if (so->so_flags1 & SOF1_PRECONNECT_DATA) {
3848 FDLOG0(LOG_INFO, fd_cb, "Delaying sending the connect packet until send or receive");
3849 do_send = 0;
3850 }
3851
3852 fd_cb->connect_packet = connect_packet;
3853 connect_packet = NULL;
3854 } else {
3855 FDLOG0(LOG_INFO, fd_cb, "Sending saved connect packet");
3856 }
3857
3858 if (do_send) {
3859 error = flow_divert_send_connect_packet(fd_cb);
3860 if (error) {
3861 goto done;
3862 }
3863
3864 fd_cb->flags |= FLOW_DIVERT_CONNECT_STARTED;
3865 }
3866
3867 if (SOCK_TYPE(so) == SOCK_DGRAM && !(fd_cb->flags & FLOW_DIVERT_HAS_TOKEN)) {
3868 soisconnected(so);
3869 } else {
3870 soisconnecting(so);
3871 }
3872
3873 done:
3874 return error;
3875 }
3876
3877 errno_t
flow_divert_connect_out(struct socket * so,struct sockaddr * to,proc_t p)3878 flow_divert_connect_out(struct socket *so, struct sockaddr *to, proc_t p)
3879 {
3880 #if CONTENT_FILTER
3881 if (SOCK_TYPE(so) == SOCK_STREAM && !(so->so_flags & SOF_CONTENT_FILTER)) {
3882 int error = cfil_sock_attach(so, NULL, to, CFS_CONNECTION_DIR_OUT);
3883 if (error != 0) {
3884 struct flow_divert_pcb *fd_cb = so->so_fd_pcb;
3885 FDLOG(LOG_ERR, fd_cb, "Failed to attach cfil: %d", error);
3886 return error;
3887 }
3888 }
3889 #endif /* CONTENT_FILTER */
3890
3891 return flow_divert_connect_out_internal(so, to, p, false);
3892 }
3893
3894 static int
flow_divert_connectx_out_common(struct socket * so,struct sockaddr * dst,struct proc * p,uint32_t ifscope,sae_connid_t * pcid,struct uio * auio,user_ssize_t * bytes_written)3895 flow_divert_connectx_out_common(struct socket *so, struct sockaddr *dst,
3896 struct proc *p, uint32_t ifscope, sae_connid_t *pcid, struct uio *auio, user_ssize_t *bytes_written)
3897 {
3898 struct inpcb *inp = sotoinpcb(so);
3899 int error;
3900
3901 if (inp == NULL) {
3902 return EINVAL;
3903 }
3904
3905 VERIFY(dst != NULL);
3906
3907 #if CONTENT_FILTER && NECP
3908 struct flow_divert_pcb *fd_cb = so->so_fd_pcb;
3909 if (fd_cb != NULL && (fd_cb->flags & FLOW_DIVERT_HAS_TOKEN) &&
3910 SOCK_TYPE(so) == SOCK_STREAM && !(so->so_flags & SOF_CONTENT_FILTER)) {
3911 inp_update_necp_policy(sotoinpcb(so), NULL, dst, 0);
3912 }
3913 #endif /* CONTENT_FILTER */
3914
3915 /* bind socket to the specified interface, if requested */
3916 if (ifscope != IFSCOPE_NONE &&
3917 (error = inp_bindif(inp, ifscope, NULL)) != 0) {
3918 return error;
3919 }
3920
3921 error = flow_divert_connect_out(so, dst, p);
3922
3923 if (error != 0) {
3924 return error;
3925 }
3926
3927 /* if there is data, send it */
3928 if (auio != NULL) {
3929 user_ssize_t datalen = 0;
3930
3931 socket_unlock(so, 0);
3932
3933 VERIFY(bytes_written != NULL);
3934
3935 datalen = uio_resid(auio);
3936 error = so->so_proto->pr_usrreqs->pru_sosend(so, NULL, (uio_t)auio, NULL, NULL, 0);
3937 socket_lock(so, 0);
3938
3939 if (error == 0 || error == EWOULDBLOCK) {
3940 *bytes_written = datalen - uio_resid(auio);
3941 }
3942
3943 /*
3944 * sosend returns EWOULDBLOCK if it's a non-blocking
3945 * socket or a timeout occured (this allows to return
3946 * the amount of queued data through sendit()).
3947 *
3948 * However, connectx() returns EINPROGRESS in case of a
3949 * blocking socket. So we change the return value here.
3950 */
3951 if (error == EWOULDBLOCK) {
3952 error = EINPROGRESS;
3953 }
3954 }
3955
3956 if (error == 0 && pcid != NULL) {
3957 *pcid = 1; /* there is only 1 connection for a TCP */
3958 }
3959
3960 return error;
3961 }
3962
3963 static int
flow_divert_connectx_out(struct socket * so,struct sockaddr * src __unused,struct sockaddr * dst,struct proc * p,uint32_t ifscope,sae_associd_t aid __unused,sae_connid_t * pcid,uint32_t flags __unused,void * arg __unused,uint32_t arglen __unused,struct uio * uio,user_ssize_t * bytes_written)3964 flow_divert_connectx_out(struct socket *so, struct sockaddr *src __unused,
3965 struct sockaddr *dst, struct proc *p, uint32_t ifscope,
3966 sae_associd_t aid __unused, sae_connid_t *pcid, uint32_t flags __unused, void *arg __unused,
3967 uint32_t arglen __unused, struct uio *uio, user_ssize_t *bytes_written)
3968 {
3969 return flow_divert_connectx_out_common(so, dst, p, ifscope, pcid, uio, bytes_written);
3970 }
3971
3972 static int
flow_divert_connectx6_out(struct socket * so,struct sockaddr * src __unused,struct sockaddr * dst,struct proc * p,uint32_t ifscope,sae_associd_t aid __unused,sae_connid_t * pcid,uint32_t flags __unused,void * arg __unused,uint32_t arglen __unused,struct uio * uio,user_ssize_t * bytes_written)3973 flow_divert_connectx6_out(struct socket *so, struct sockaddr *src __unused,
3974 struct sockaddr *dst, struct proc *p, uint32_t ifscope,
3975 sae_associd_t aid __unused, sae_connid_t *pcid, uint32_t flags __unused, void *arg __unused,
3976 uint32_t arglen __unused, struct uio *uio, user_ssize_t *bytes_written)
3977 {
3978 return flow_divert_connectx_out_common(so, dst, p, ifscope, pcid, uio, bytes_written);
3979 }
3980
3981 static errno_t
flow_divert_data_out(struct socket * so,int flags,mbuf_t data,struct sockaddr * to,mbuf_t control,struct proc * p)3982 flow_divert_data_out(struct socket *so, int flags, mbuf_t data, struct sockaddr *to, mbuf_t control, struct proc *p)
3983 {
3984 struct flow_divert_pcb *fd_cb = so->so_fd_pcb;
3985 int error = 0;
3986 struct inpcb *inp;
3987 #if CONTENT_FILTER
3988 struct m_tag *cfil_tag = NULL;
3989 #endif
3990
3991 if (!SO_IS_DIVERTED(so)) {
3992 return EINVAL;
3993 }
3994
3995 inp = sotoinpcb(so);
3996 if (inp == NULL || inp->inp_state == INPCB_STATE_DEAD) {
3997 error = ECONNRESET;
3998 goto done;
3999 }
4000
4001 if ((fd_cb->flags & FLOW_DIVERT_TUNNEL_WR_CLOSED) && SOCK_TYPE(so) == SOCK_DGRAM) {
4002 /* The provider considers this datagram flow to be closed, so no data can be sent */
4003 FDLOG0(LOG_INFO, fd_cb, "provider is no longer accepting writes, cannot send data");
4004 error = EHOSTUNREACH;
4005 goto done;
4006 }
4007
4008 #if CONTENT_FILTER
4009 /*
4010 * If the socket is subject to a UDP Content Filter and no remote address is passed in,
4011 * retrieve the CFIL saved remote address from the mbuf and use it.
4012 */
4013 if (to == NULL && CFIL_DGRAM_FILTERED(so)) {
4014 struct sockaddr *cfil_faddr = NULL;
4015 cfil_tag = cfil_dgram_get_socket_state(data, NULL, NULL, &cfil_faddr, NULL);
4016 if (cfil_tag) {
4017 to = (struct sockaddr *)(void *)cfil_faddr;
4018 }
4019 FDLOG(LOG_INFO, fd_cb, "Using remote address from CFIL saved state: %p", to);
4020 }
4021 #endif
4022
4023 /* Implicit connect */
4024 if (!(fd_cb->flags & FLOW_DIVERT_CONNECT_STARTED)) {
4025 FDLOG0(LOG_INFO, fd_cb, "implicit connect");
4026
4027 error = flow_divert_connect_out_internal(so, to, p, true);
4028 if (error) {
4029 goto done;
4030 }
4031 } else {
4032 error = flow_divert_check_no_cellular(fd_cb) ||
4033 flow_divert_check_no_expensive(fd_cb) ||
4034 flow_divert_check_no_constrained(fd_cb);
4035 if (error) {
4036 goto done;
4037 }
4038 }
4039
4040 if (data != NULL) {
4041 size_t data_size = 0;
4042 if (mbuf_flags(data) & M_PKTHDR) {
4043 data_size = mbuf_pkthdr_len(data);
4044 } else {
4045 for (mbuf_t blob = data; blob != NULL; blob = mbuf_next(blob)) {
4046 data_size += mbuf_len(blob);
4047 }
4048 }
4049
4050 FDLOG(LOG_DEBUG, fd_cb, "app wrote %lu bytes", data_size);
4051 fd_cb->bytes_written_by_app += data_size;
4052
4053 error = flow_divert_send_app_data(fd_cb, data, data_size, to);
4054
4055 data = NULL;
4056
4057 if (error) {
4058 goto done;
4059 }
4060 }
4061
4062 if (flags & PRUS_EOF) {
4063 flow_divert_shutdown(so);
4064 }
4065
4066 done:
4067 if (data) {
4068 mbuf_freem(data);
4069 }
4070 if (control) {
4071 mbuf_free(control);
4072 }
4073 #if CONTENT_FILTER
4074 if (cfil_tag) {
4075 m_tag_free(cfil_tag);
4076 }
4077 #endif
4078
4079 return error;
4080 }
4081
4082 static int
flow_divert_preconnect(struct socket * so)4083 flow_divert_preconnect(struct socket *so)
4084 {
4085 int error = 0;
4086 struct flow_divert_pcb *fd_cb = so->so_fd_pcb;
4087
4088 if (!SO_IS_DIVERTED(so)) {
4089 return EINVAL;
4090 }
4091
4092 if (!(fd_cb->flags & FLOW_DIVERT_CONNECT_STARTED)) {
4093 FDLOG0(LOG_INFO, fd_cb, "Pre-connect read: sending saved connect packet");
4094 error = flow_divert_send_connect_packet(so->so_fd_pcb);
4095 if (error) {
4096 return error;
4097 }
4098
4099 fd_cb->flags |= FLOW_DIVERT_CONNECT_STARTED;
4100 }
4101
4102 soclearfastopen(so);
4103
4104 return error;
4105 }
4106
4107 static void
flow_divert_set_protosw(struct socket * so)4108 flow_divert_set_protosw(struct socket *so)
4109 {
4110 if (SOCK_DOM(so) == PF_INET) {
4111 so->so_proto = &g_flow_divert_in_protosw;
4112 } else {
4113 so->so_proto = (struct protosw *)&g_flow_divert_in6_protosw;
4114 }
4115 }
4116
4117 static void
flow_divert_set_udp_protosw(struct socket * so)4118 flow_divert_set_udp_protosw(struct socket *so)
4119 {
4120 if (SOCK_DOM(so) == PF_INET) {
4121 so->so_proto = &g_flow_divert_in_udp_protosw;
4122 } else {
4123 so->so_proto = (struct protosw *)&g_flow_divert_in6_udp_protosw;
4124 }
4125 }
4126
4127 errno_t
flow_divert_implicit_data_out(struct socket * so,int flags,mbuf_t data,struct sockaddr * to,mbuf_t control,struct proc * p)4128 flow_divert_implicit_data_out(struct socket *so, int flags, mbuf_t data, struct sockaddr *to, mbuf_t control, struct proc *p)
4129 {
4130 struct flow_divert_pcb *fd_cb = so->so_fd_pcb;
4131 struct inpcb *inp;
4132 int error = 0;
4133
4134 inp = sotoinpcb(so);
4135 if (inp == NULL) {
4136 return EINVAL;
4137 }
4138
4139 if (fd_cb == NULL) {
4140 error = flow_divert_pcb_init(so);
4141 fd_cb = so->so_fd_pcb;
4142 if (error != 0 || fd_cb == NULL) {
4143 goto done;
4144 }
4145 }
4146 return flow_divert_data_out(so, flags, data, to, control, p);
4147
4148 done:
4149 if (data) {
4150 mbuf_freem(data);
4151 }
4152 if (control) {
4153 mbuf_free(control);
4154 }
4155
4156 return error;
4157 }
4158
4159 static errno_t
flow_divert_pcb_init_internal(struct socket * so,uint32_t ctl_unit,uint32_t aggregate_unit)4160 flow_divert_pcb_init_internal(struct socket *so, uint32_t ctl_unit, uint32_t aggregate_unit)
4161 {
4162 errno_t error = 0;
4163 struct flow_divert_pcb *fd_cb = NULL;
4164 uint32_t agg_unit = aggregate_unit;
4165 uint32_t policy_control_unit = ctl_unit;
4166 bool is_aggregate = false;
4167
4168 if (so->so_flags & SOF_FLOW_DIVERT) {
4169 return EALREADY;
4170 }
4171
4172 fd_cb = flow_divert_pcb_create(so);
4173 if (fd_cb == NULL) {
4174 return ENOMEM;
4175 }
4176
4177 do {
4178 uint32_t group_unit = flow_divert_derive_kernel_control_unit(so->last_pid, &policy_control_unit, &agg_unit, &is_aggregate);
4179 if (group_unit == 0 || (group_unit >= GROUP_COUNT_MAX && group_unit < FLOW_DIVERT_IN_PROCESS_UNIT_MIN)) {
4180 FDLOG0(LOG_ERR, fd_cb, "No valid group is available, cannot init flow divert");
4181 error = EINVAL;
4182 break;
4183 }
4184
4185 error = flow_divert_add_to_group(fd_cb, group_unit);
4186 if (error == 0) {
4187 so->so_fd_pcb = fd_cb;
4188 so->so_flags |= SOF_FLOW_DIVERT;
4189 fd_cb->control_group_unit = group_unit;
4190 fd_cb->policy_control_unit = ctl_unit;
4191 fd_cb->aggregate_unit = agg_unit;
4192 if (is_aggregate) {
4193 fd_cb->flags |= FLOW_DIVERT_FLOW_IS_TRANSPARENT;
4194 } else {
4195 fd_cb->flags &= ~FLOW_DIVERT_FLOW_IS_TRANSPARENT;
4196 }
4197
4198 if (SOCK_TYPE(so) == SOCK_STREAM) {
4199 flow_divert_set_protosw(so);
4200 } else if (SOCK_TYPE(so) == SOCK_DGRAM) {
4201 flow_divert_set_udp_protosw(so);
4202 }
4203
4204 FDLOG0(LOG_INFO, fd_cb, "Created");
4205 } else if (error != ENOENT) {
4206 FDLOG(LOG_ERR, fd_cb, "pcb insert failed: %d", error);
4207 }
4208 } while (error == ENOENT);
4209
4210 if (error != 0) {
4211 FDRELEASE(fd_cb);
4212 }
4213
4214 return error;
4215 }
4216
4217 errno_t
flow_divert_pcb_init(struct socket * so)4218 flow_divert_pcb_init(struct socket *so)
4219 {
4220 struct inpcb *inp = sotoinpcb(so);
4221 uint32_t aggregate_units = 0;
4222 uint32_t ctl_unit = necp_socket_get_flow_divert_control_unit(inp, &aggregate_units);
4223 return flow_divert_pcb_init_internal(so, ctl_unit, aggregate_units);
4224 }
4225
4226 errno_t
flow_divert_token_set(struct socket * so,struct sockopt * sopt)4227 flow_divert_token_set(struct socket *so, struct sockopt *sopt)
4228 {
4229 uint32_t ctl_unit = 0;
4230 uint32_t key_unit = 0;
4231 uint32_t aggregate_unit = 0;
4232 int error = 0;
4233 int hmac_error = 0;
4234 mbuf_t token = NULL;
4235
4236 if (so->so_flags & SOF_FLOW_DIVERT) {
4237 error = EALREADY;
4238 goto done;
4239 }
4240
4241 if (g_init_result) {
4242 FDLOG(LOG_ERR, &nil_pcb, "flow_divert_init failed (%d), cannot use flow divert", g_init_result);
4243 error = ENOPROTOOPT;
4244 goto done;
4245 }
4246
4247 if ((SOCK_TYPE(so) != SOCK_STREAM && SOCK_TYPE(so) != SOCK_DGRAM) ||
4248 (SOCK_PROTO(so) != IPPROTO_TCP && SOCK_PROTO(so) != IPPROTO_UDP) ||
4249 (SOCK_DOM(so) != PF_INET && SOCK_DOM(so) != PF_INET6)) {
4250 error = EINVAL;
4251 goto done;
4252 } else {
4253 if (SOCK_TYPE(so) == SOCK_STREAM && SOCK_PROTO(so) == IPPROTO_TCP) {
4254 struct tcpcb *tp = sototcpcb(so);
4255 if (tp == NULL || tp->t_state != TCPS_CLOSED) {
4256 error = EINVAL;
4257 goto done;
4258 }
4259 }
4260 }
4261
4262 error = soopt_getm(sopt, &token);
4263 if (error) {
4264 token = NULL;
4265 goto done;
4266 }
4267
4268 error = soopt_mcopyin(sopt, token);
4269 if (error) {
4270 token = NULL;
4271 goto done;
4272 }
4273
4274 error = flow_divert_packet_get_tlv(token, 0, FLOW_DIVERT_TLV_KEY_UNIT, sizeof(key_unit), (void *)&key_unit, NULL);
4275 if (!error) {
4276 key_unit = ntohl(key_unit);
4277 if (key_unit >= GROUP_COUNT_MAX) {
4278 key_unit = 0;
4279 }
4280 } else if (error != ENOENT) {
4281 FDLOG(LOG_ERR, &nil_pcb, "Failed to get the key unit from the token: %d", error);
4282 goto done;
4283 } else {
4284 key_unit = 0;
4285 }
4286
4287 error = flow_divert_packet_get_tlv(token, 0, FLOW_DIVERT_TLV_CTL_UNIT, sizeof(ctl_unit), (void *)&ctl_unit, NULL);
4288 if (error) {
4289 FDLOG(LOG_ERR, &nil_pcb, "Failed to get the control socket unit from the token: %d", error);
4290 goto done;
4291 }
4292
4293 error = flow_divert_packet_get_tlv(token, 0, FLOW_DIVERT_TLV_AGGREGATE_UNIT, sizeof(aggregate_unit), (void *)&aggregate_unit, NULL);
4294 if (error && error != ENOENT) {
4295 FDLOG(LOG_ERR, &nil_pcb, "Failed to get the aggregate unit from the token: %d", error);
4296 goto done;
4297 }
4298
4299 /* A valid kernel control unit is required */
4300 ctl_unit = ntohl(ctl_unit);
4301 aggregate_unit = ntohl(aggregate_unit);
4302
4303 if (ctl_unit > 0 && ctl_unit < GROUP_COUNT_MAX) {
4304 hmac_error = flow_divert_packet_verify_hmac(token, (key_unit != 0 ? key_unit : ctl_unit));
4305 if (hmac_error && hmac_error != ENOENT) {
4306 FDLOG(LOG_ERR, &nil_pcb, "HMAC verfication failed: %d", hmac_error);
4307 error = hmac_error;
4308 goto done;
4309 }
4310 }
4311
4312 error = flow_divert_pcb_init_internal(so, ctl_unit, aggregate_unit);
4313 if (error == 0) {
4314 struct flow_divert_pcb *fd_cb = so->so_fd_pcb;
4315 int log_level = LOG_NOTICE;
4316
4317 error = flow_divert_packet_get_tlv(token, 0, FLOW_DIVERT_TLV_LOG_LEVEL, sizeof(log_level), &log_level, NULL);
4318 if (error == 0) {
4319 fd_cb->log_level = (uint8_t)log_level;
4320 }
4321 error = 0;
4322
4323 fd_cb->connect_token = token;
4324 token = NULL;
4325
4326 fd_cb->flags |= FLOW_DIVERT_HAS_TOKEN;
4327 }
4328
4329 if (hmac_error == 0) {
4330 struct flow_divert_pcb *fd_cb = so->so_fd_pcb;
4331 if (fd_cb != NULL) {
4332 fd_cb->flags |= FLOW_DIVERT_HAS_HMAC;
4333 }
4334 }
4335
4336 done:
4337 if (token != NULL) {
4338 mbuf_freem(token);
4339 }
4340
4341 return error;
4342 }
4343
4344 errno_t
flow_divert_token_get(struct socket * so,struct sockopt * sopt)4345 flow_divert_token_get(struct socket *so, struct sockopt *sopt)
4346 {
4347 uint32_t ctl_unit;
4348 int error = 0;
4349 uint8_t hmac[SHA_DIGEST_LENGTH];
4350 struct flow_divert_pcb *fd_cb = so->so_fd_pcb;
4351 mbuf_t token = NULL;
4352 struct flow_divert_group *control_group = NULL;
4353
4354 if (!SO_IS_DIVERTED(so)) {
4355 error = EINVAL;
4356 goto done;
4357 }
4358
4359 if (fd_cb->group == NULL) {
4360 error = EINVAL;
4361 goto done;
4362 }
4363
4364 error = mbuf_gethdr(MBUF_DONTWAIT, MBUF_TYPE_HEADER, &token);
4365 if (error) {
4366 FDLOG(LOG_ERR, fd_cb, "failed to allocate the header mbuf: %d", error);
4367 goto done;
4368 }
4369
4370 ctl_unit = htonl(fd_cb->group->ctl_unit);
4371
4372 error = flow_divert_packet_append_tlv(token, FLOW_DIVERT_TLV_CTL_UNIT, sizeof(ctl_unit), &ctl_unit);
4373 if (error) {
4374 goto done;
4375 }
4376
4377 error = flow_divert_packet_append_tlv(token, FLOW_DIVERT_TLV_FLOW_ID, sizeof(fd_cb->hash), &fd_cb->hash);
4378 if (error) {
4379 goto done;
4380 }
4381
4382 if (fd_cb->app_data != NULL) {
4383 error = flow_divert_packet_append_tlv(token, FLOW_DIVERT_TLV_APP_DATA, (uint32_t)fd_cb->app_data_length, fd_cb->app_data);
4384 if (error) {
4385 goto done;
4386 }
4387 }
4388
4389 control_group = flow_divert_group_lookup(fd_cb->control_group_unit, fd_cb);
4390 if (control_group != NULL) {
4391 lck_rw_lock_shared(&control_group->lck);
4392 ctl_unit = htonl(control_group->ctl_unit);
4393 error = flow_divert_packet_append_tlv(token, FLOW_DIVERT_TLV_KEY_UNIT, sizeof(ctl_unit), &ctl_unit);
4394 if (!error) {
4395 error = flow_divert_packet_compute_hmac(token, control_group, hmac);
4396 }
4397 lck_rw_done(&control_group->lck);
4398 FDGRP_RELEASE(control_group);
4399 } else {
4400 error = ENOPROTOOPT;
4401 }
4402
4403 if (error) {
4404 goto done;
4405 }
4406
4407 error = flow_divert_packet_append_tlv(token, FLOW_DIVERT_TLV_HMAC, sizeof(hmac), hmac);
4408 if (error) {
4409 goto done;
4410 }
4411
4412 if (sopt->sopt_val == USER_ADDR_NULL) {
4413 /* If the caller passed NULL to getsockopt, just set the size of the token and return */
4414 sopt->sopt_valsize = mbuf_pkthdr_len(token);
4415 goto done;
4416 }
4417
4418 error = soopt_mcopyout(sopt, token);
4419 if (error) {
4420 token = NULL; /* For some reason, soopt_mcopyout() frees the mbuf if it fails */
4421 goto done;
4422 }
4423
4424 done:
4425 if (token != NULL) {
4426 mbuf_freem(token);
4427 }
4428
4429 return error;
4430 }
4431
4432 void
flow_divert_group_destroy(struct flow_divert_group * group)4433 flow_divert_group_destroy(struct flow_divert_group *group)
4434 {
4435 lck_rw_lock_exclusive(&group->lck);
4436
4437 FDLOG(LOG_NOTICE, &nil_pcb, "Destroying group %u", group->ctl_unit);
4438
4439 if (group->token_key != NULL) {
4440 memset(group->token_key, 0, group->token_key_size);
4441 kfree_data(group->token_key, group->token_key_size);
4442 group->token_key = NULL;
4443 group->token_key_size = 0;
4444 }
4445
4446 /* Re-set the current trie */
4447 if (group->signing_id_trie.memory != NULL) {
4448 kfree_data_addr(group->signing_id_trie.memory);
4449 }
4450 memset(&group->signing_id_trie, 0, sizeof(group->signing_id_trie));
4451 group->signing_id_trie.root = NULL_TRIE_IDX;
4452
4453 lck_rw_done(&group->lck);
4454
4455 zfree(flow_divert_group_zone, group);
4456 }
4457
4458 static struct flow_divert_group *
flow_divert_allocate_group(u_int32_t unit,pid_t pid)4459 flow_divert_allocate_group(u_int32_t unit, pid_t pid)
4460 {
4461 struct flow_divert_group *new_group = NULL;
4462 new_group = zalloc_flags(flow_divert_group_zone, Z_WAITOK | Z_ZERO);
4463 lck_rw_init(&new_group->lck, &flow_divert_mtx_grp, &flow_divert_mtx_attr);
4464 RB_INIT(&new_group->pcb_tree);
4465 new_group->ctl_unit = unit;
4466 new_group->in_process_pid = pid;
4467 MBUFQ_INIT(&new_group->send_queue);
4468 new_group->signing_id_trie.root = NULL_TRIE_IDX;
4469 new_group->ref_count = 1;
4470 new_group->order = FLOW_DIVERT_ORDER_LAST;
4471 return new_group;
4472 }
4473
4474 static errno_t
flow_divert_kctl_setup(u_int32_t * unit,void ** unitinfo)4475 flow_divert_kctl_setup(u_int32_t *unit, void **unitinfo)
4476 {
4477 if (unit == NULL || unitinfo == NULL) {
4478 return EINVAL;
4479 }
4480
4481 struct flow_divert_group *new_group = NULL;
4482 errno_t error = 0;
4483 lck_rw_lock_shared(&g_flow_divert_group_lck);
4484 if (*unit == FLOW_DIVERT_IN_PROCESS_UNIT) {
4485 // Return next unused in-process unit
4486 u_int32_t unit_cursor = FLOW_DIVERT_IN_PROCESS_UNIT_MIN;
4487 struct flow_divert_group *group_next = NULL;
4488 TAILQ_FOREACH(group_next, &g_flow_divert_in_process_group_list, chain) {
4489 if (group_next->ctl_unit > unit_cursor) {
4490 // Found a gap, lets fill it in
4491 break;
4492 }
4493 unit_cursor = group_next->ctl_unit + 1;
4494 if (unit_cursor == FLOW_DIVERT_IN_PROCESS_UNIT_MAX) {
4495 break;
4496 }
4497 }
4498 if (unit_cursor == FLOW_DIVERT_IN_PROCESS_UNIT_MAX) {
4499 error = EBUSY;
4500 } else {
4501 *unit = unit_cursor;
4502 new_group = flow_divert_allocate_group(*unit, proc_pid(current_proc()));
4503 if (group_next != NULL) {
4504 TAILQ_INSERT_BEFORE(group_next, new_group, chain);
4505 } else {
4506 TAILQ_INSERT_TAIL(&g_flow_divert_in_process_group_list, new_group, chain);
4507 }
4508 g_active_group_count++;
4509 }
4510 } else {
4511 if (kauth_cred_issuser(kauth_cred_get()) == 0) {
4512 error = EPERM;
4513 } else {
4514 if (g_flow_divert_groups == NULL) {
4515 g_flow_divert_groups = kalloc_type(struct flow_divert_group *,
4516 GROUP_COUNT_MAX, Z_WAITOK | Z_ZERO | Z_NOFAIL);
4517 }
4518
4519 // Return next unused group unit
4520 bool found_unused_unit = false;
4521 u_int32_t unit_cursor;
4522 for (unit_cursor = 1; unit_cursor < GROUP_COUNT_MAX; unit_cursor++) {
4523 struct flow_divert_group *group = g_flow_divert_groups[unit_cursor];
4524 if (group == NULL) {
4525 // Open slot, assign this one
4526 *unit = unit_cursor;
4527 new_group = flow_divert_allocate_group(*unit, 0);
4528 g_flow_divert_groups[*unit] = new_group;
4529 found_unused_unit = true;
4530 g_active_group_count++;
4531 break;
4532 }
4533 }
4534 if (!found_unused_unit) {
4535 error = EBUSY;
4536 }
4537 }
4538 }
4539 lck_rw_done(&g_flow_divert_group_lck);
4540
4541 *unitinfo = new_group;
4542
4543 return error;
4544 }
4545
4546 static errno_t
flow_divert_kctl_connect(kern_ctl_ref kctlref __unused,struct sockaddr_ctl * sac,void ** unitinfo)4547 flow_divert_kctl_connect(kern_ctl_ref kctlref __unused, struct sockaddr_ctl *sac, void **unitinfo)
4548 {
4549 if (unitinfo == NULL) {
4550 return EINVAL;
4551 }
4552
4553 // Just validate. The group will already have been allocated.
4554 struct flow_divert_group *group = (struct flow_divert_group *)*unitinfo;
4555 if (group == NULL || sac->sc_unit != group->ctl_unit) {
4556 FDLOG(LOG_ERR, &nil_pcb, "Flow divert connect fail, unit mismatch %u != %u",
4557 sac->sc_unit, group ? group->ctl_unit : 0);
4558 return EINVAL;
4559 }
4560
4561 return 0;
4562 }
4563
4564 static errno_t
flow_divert_kctl_disconnect(kern_ctl_ref kctlref __unused,uint32_t unit,void * unitinfo)4565 flow_divert_kctl_disconnect(kern_ctl_ref kctlref __unused, uint32_t unit, void *unitinfo)
4566 {
4567 struct flow_divert_group *group = NULL;
4568 errno_t error = 0;
4569
4570 if (unitinfo == NULL) {
4571 return 0;
4572 }
4573
4574 FDLOG(LOG_INFO, &nil_pcb, "disconnecting group %d", unit);
4575
4576 lck_rw_lock_exclusive(&g_flow_divert_group_lck);
4577
4578 if (g_active_group_count == 0) {
4579 panic("flow divert group %u is disconnecting, but no groups are active (active count = %u)",
4580 unit, g_active_group_count);
4581 }
4582
4583 if (unit < FLOW_DIVERT_IN_PROCESS_UNIT_MIN) {
4584 if (unit >= GROUP_COUNT_MAX) {
4585 return EINVAL;
4586 }
4587
4588 if (g_flow_divert_groups == NULL) {
4589 panic("flow divert group %u is disconnecting, but groups array is NULL",
4590 unit);
4591 }
4592 group = g_flow_divert_groups[unit];
4593
4594 if (group != (struct flow_divert_group *)unitinfo) {
4595 panic("group with unit %d (%p) != unit info (%p)", unit, group, unitinfo);
4596 }
4597
4598 g_flow_divert_groups[unit] = NULL;
4599 } else {
4600 group = (struct flow_divert_group *)unitinfo;
4601 if (TAILQ_EMPTY(&g_flow_divert_in_process_group_list)) {
4602 panic("flow divert group %u is disconnecting, but in-process group list is empty",
4603 unit);
4604 }
4605
4606 TAILQ_REMOVE(&g_flow_divert_in_process_group_list, group, chain);
4607 }
4608
4609 g_active_group_count--;
4610
4611 if (g_active_group_count == 0) {
4612 kfree_type(struct flow_divert_group *,
4613 GROUP_COUNT_MAX, g_flow_divert_groups);
4614 g_flow_divert_groups = NULL;
4615 }
4616
4617 lck_rw_done(&g_flow_divert_group_lck);
4618
4619 if (group != NULL) {
4620 flow_divert_close_all(group);
4621 FDGRP_RELEASE(group);
4622 } else {
4623 error = EINVAL;
4624 }
4625
4626 return error;
4627 }
4628
4629 static errno_t
flow_divert_kctl_send(__unused kern_ctl_ref kctlref,uint32_t unit,__unused void * unitinfo,mbuf_t m,__unused int flags)4630 flow_divert_kctl_send(__unused kern_ctl_ref kctlref, uint32_t unit, __unused void *unitinfo, mbuf_t m, __unused int flags)
4631 {
4632 errno_t error = 0;
4633 struct flow_divert_group *group = flow_divert_group_lookup(unit, NULL);
4634 if (group != NULL) {
4635 error = flow_divert_input(m, group);
4636 FDGRP_RELEASE(group);
4637 } else {
4638 error = ENOENT;
4639 }
4640 return error;
4641 }
4642
4643 static void
flow_divert_kctl_rcvd(__unused kern_ctl_ref kctlref,uint32_t unit,__unused void * unitinfo,__unused int flags)4644 flow_divert_kctl_rcvd(__unused kern_ctl_ref kctlref, uint32_t unit, __unused void *unitinfo, __unused int flags)
4645 {
4646 struct flow_divert_group *group = flow_divert_group_lookup(unit, NULL);
4647 if (group == NULL) {
4648 return;
4649 }
4650
4651 if (!OSTestAndClear(GROUP_BIT_CTL_ENQUEUE_BLOCKED, &group->atomic_bits)) {
4652 struct flow_divert_pcb *fd_cb;
4653 SLIST_HEAD(, flow_divert_pcb) tmp_list;
4654
4655 lck_rw_lock_exclusive(&group->lck);
4656
4657 while (!MBUFQ_EMPTY(&group->send_queue)) {
4658 mbuf_t next_packet;
4659 FDLOG0(LOG_DEBUG, &nil_pcb, "trying ctl_enqueuembuf again");
4660 next_packet = MBUFQ_FIRST(&group->send_queue);
4661 int error = ctl_enqueuembuf(g_flow_divert_kctl_ref, group->ctl_unit, next_packet, CTL_DATA_EOR);
4662 if (error) {
4663 FDLOG(LOG_NOTICE, &nil_pcb, "flow_divert_kctl_rcvd: ctl_enqueuembuf returned an error: %d", error);
4664 OSTestAndSet(GROUP_BIT_CTL_ENQUEUE_BLOCKED, &group->atomic_bits);
4665 lck_rw_done(&group->lck);
4666 return;
4667 }
4668 MBUFQ_DEQUEUE(&group->send_queue, next_packet);
4669 }
4670
4671 SLIST_INIT(&tmp_list);
4672
4673 RB_FOREACH(fd_cb, fd_pcb_tree, &group->pcb_tree) {
4674 FDRETAIN(fd_cb);
4675 SLIST_INSERT_HEAD(&tmp_list, fd_cb, tmp_list_entry);
4676 }
4677
4678 lck_rw_done(&group->lck);
4679
4680 SLIST_FOREACH(fd_cb, &tmp_list, tmp_list_entry) {
4681 FDLOCK(fd_cb);
4682 if (fd_cb->so != NULL) {
4683 socket_lock(fd_cb->so, 0);
4684 if (fd_cb->group != NULL) {
4685 flow_divert_send_buffered_data(fd_cb, FALSE);
4686 }
4687 socket_unlock(fd_cb->so, 0);
4688 }
4689 FDUNLOCK(fd_cb);
4690 FDRELEASE(fd_cb);
4691 }
4692 }
4693
4694 FDGRP_RELEASE(group);
4695 }
4696
4697 static int
flow_divert_kctl_init(void)4698 flow_divert_kctl_init(void)
4699 {
4700 struct kern_ctl_reg ctl_reg;
4701 int result;
4702
4703 memset(&ctl_reg, 0, sizeof(ctl_reg));
4704
4705 strlcpy(ctl_reg.ctl_name, FLOW_DIVERT_CONTROL_NAME, sizeof(ctl_reg.ctl_name));
4706 ctl_reg.ctl_name[sizeof(ctl_reg.ctl_name) - 1] = '\0';
4707
4708 // Do not restrict to privileged processes. flow_divert_kctl_setup checks
4709 // permissions separately.
4710 ctl_reg.ctl_flags = CTL_FLAG_REG_EXTENDED | CTL_FLAG_REG_SETUP;
4711 ctl_reg.ctl_sendsize = FD_CTL_SENDBUFF_SIZE;
4712
4713 ctl_reg.ctl_connect = flow_divert_kctl_connect;
4714 ctl_reg.ctl_disconnect = flow_divert_kctl_disconnect;
4715 ctl_reg.ctl_send = flow_divert_kctl_send;
4716 ctl_reg.ctl_rcvd = flow_divert_kctl_rcvd;
4717 ctl_reg.ctl_setup = flow_divert_kctl_setup;
4718
4719 result = ctl_register(&ctl_reg, &g_flow_divert_kctl_ref);
4720
4721 if (result) {
4722 FDLOG(LOG_ERR, &nil_pcb, "flow_divert_kctl_init - ctl_register failed: %d\n", result);
4723 return result;
4724 }
4725
4726 return 0;
4727 }
4728
4729 void
flow_divert_init(void)4730 flow_divert_init(void)
4731 {
4732 memset(&nil_pcb, 0, sizeof(nil_pcb));
4733 nil_pcb.log_level = LOG_NOTICE;
4734
4735 g_tcp_protosw = pffindproto(AF_INET, IPPROTO_TCP, SOCK_STREAM);
4736
4737 VERIFY(g_tcp_protosw != NULL);
4738
4739 memcpy(&g_flow_divert_in_protosw, g_tcp_protosw, sizeof(g_flow_divert_in_protosw));
4740 memcpy(&g_flow_divert_in_usrreqs, g_tcp_protosw->pr_usrreqs, sizeof(g_flow_divert_in_usrreqs));
4741
4742 g_flow_divert_in_usrreqs.pru_connect = flow_divert_connect_out;
4743 g_flow_divert_in_usrreqs.pru_connectx = flow_divert_connectx_out;
4744 g_flow_divert_in_usrreqs.pru_disconnect = flow_divert_close;
4745 g_flow_divert_in_usrreqs.pru_disconnectx = flow_divert_disconnectx;
4746 g_flow_divert_in_usrreqs.pru_rcvd = flow_divert_rcvd;
4747 g_flow_divert_in_usrreqs.pru_send = flow_divert_data_out;
4748 g_flow_divert_in_usrreqs.pru_shutdown = flow_divert_shutdown;
4749 g_flow_divert_in_usrreqs.pru_preconnect = flow_divert_preconnect;
4750
4751 g_flow_divert_in_protosw.pr_usrreqs = &g_flow_divert_in_usrreqs;
4752 g_flow_divert_in_protosw.pr_ctloutput = flow_divert_ctloutput;
4753
4754 /*
4755 * Socket filters shouldn't attach/detach to/from this protosw
4756 * since pr_protosw is to be used instead, which points to the
4757 * real protocol; if they do, it is a bug and we should panic.
4758 */
4759 g_flow_divert_in_protosw.pr_filter_head.tqh_first =
4760 (struct socket_filter *)(uintptr_t)0xdeadbeefdeadbeef;
4761 g_flow_divert_in_protosw.pr_filter_head.tqh_last =
4762 (struct socket_filter **)(uintptr_t)0xdeadbeefdeadbeef;
4763
4764 /* UDP */
4765 g_udp_protosw = pffindproto(AF_INET, IPPROTO_UDP, SOCK_DGRAM);
4766 VERIFY(g_udp_protosw != NULL);
4767
4768 memcpy(&g_flow_divert_in_udp_protosw, g_udp_protosw, sizeof(g_flow_divert_in_udp_protosw));
4769 memcpy(&g_flow_divert_in_udp_usrreqs, g_udp_protosw->pr_usrreqs, sizeof(g_flow_divert_in_udp_usrreqs));
4770
4771 g_flow_divert_in_udp_usrreqs.pru_connect = flow_divert_connect_out;
4772 g_flow_divert_in_udp_usrreqs.pru_connectx = flow_divert_connectx_out;
4773 g_flow_divert_in_udp_usrreqs.pru_disconnect = flow_divert_close;
4774 g_flow_divert_in_udp_usrreqs.pru_disconnectx = flow_divert_disconnectx;
4775 g_flow_divert_in_udp_usrreqs.pru_rcvd = flow_divert_rcvd;
4776 g_flow_divert_in_udp_usrreqs.pru_send = flow_divert_data_out;
4777 g_flow_divert_in_udp_usrreqs.pru_shutdown = flow_divert_shutdown;
4778 g_flow_divert_in_udp_usrreqs.pru_sosend_list = pru_sosend_list_notsupp;
4779 g_flow_divert_in_udp_usrreqs.pru_preconnect = flow_divert_preconnect;
4780
4781 g_flow_divert_in_udp_protosw.pr_usrreqs = &g_flow_divert_in_usrreqs;
4782 g_flow_divert_in_udp_protosw.pr_ctloutput = flow_divert_ctloutput;
4783
4784 /*
4785 * Socket filters shouldn't attach/detach to/from this protosw
4786 * since pr_protosw is to be used instead, which points to the
4787 * real protocol; if they do, it is a bug and we should panic.
4788 */
4789 g_flow_divert_in_udp_protosw.pr_filter_head.tqh_first =
4790 (struct socket_filter *)(uintptr_t)0xdeadbeefdeadbeef;
4791 g_flow_divert_in_udp_protosw.pr_filter_head.tqh_last =
4792 (struct socket_filter **)(uintptr_t)0xdeadbeefdeadbeef;
4793
4794 g_tcp6_protosw = (struct ip6protosw *)pffindproto(AF_INET6, IPPROTO_TCP, SOCK_STREAM);
4795
4796 VERIFY(g_tcp6_protosw != NULL);
4797
4798 memcpy(&g_flow_divert_in6_protosw, g_tcp6_protosw, sizeof(g_flow_divert_in6_protosw));
4799 memcpy(&g_flow_divert_in6_usrreqs, g_tcp6_protosw->pr_usrreqs, sizeof(g_flow_divert_in6_usrreqs));
4800
4801 g_flow_divert_in6_usrreqs.pru_connect = flow_divert_connect_out;
4802 g_flow_divert_in6_usrreqs.pru_connectx = flow_divert_connectx6_out;
4803 g_flow_divert_in6_usrreqs.pru_disconnect = flow_divert_close;
4804 g_flow_divert_in6_usrreqs.pru_disconnectx = flow_divert_disconnectx;
4805 g_flow_divert_in6_usrreqs.pru_rcvd = flow_divert_rcvd;
4806 g_flow_divert_in6_usrreqs.pru_send = flow_divert_data_out;
4807 g_flow_divert_in6_usrreqs.pru_shutdown = flow_divert_shutdown;
4808 g_flow_divert_in6_usrreqs.pru_preconnect = flow_divert_preconnect;
4809
4810 g_flow_divert_in6_protosw.pr_usrreqs = &g_flow_divert_in6_usrreqs;
4811 g_flow_divert_in6_protosw.pr_ctloutput = flow_divert_ctloutput;
4812 /*
4813 * Socket filters shouldn't attach/detach to/from this protosw
4814 * since pr_protosw is to be used instead, which points to the
4815 * real protocol; if they do, it is a bug and we should panic.
4816 */
4817 g_flow_divert_in6_protosw.pr_filter_head.tqh_first =
4818 (struct socket_filter *)(uintptr_t)0xdeadbeefdeadbeef;
4819 g_flow_divert_in6_protosw.pr_filter_head.tqh_last =
4820 (struct socket_filter **)(uintptr_t)0xdeadbeefdeadbeef;
4821
4822 /* UDP6 */
4823 g_udp6_protosw = (struct ip6protosw *)pffindproto(AF_INET6, IPPROTO_UDP, SOCK_DGRAM);
4824
4825 VERIFY(g_udp6_protosw != NULL);
4826
4827 memcpy(&g_flow_divert_in6_udp_protosw, g_udp6_protosw, sizeof(g_flow_divert_in6_udp_protosw));
4828 memcpy(&g_flow_divert_in6_udp_usrreqs, g_udp6_protosw->pr_usrreqs, sizeof(g_flow_divert_in6_udp_usrreqs));
4829
4830 g_flow_divert_in6_udp_usrreqs.pru_connect = flow_divert_connect_out;
4831 g_flow_divert_in6_udp_usrreqs.pru_connectx = flow_divert_connectx6_out;
4832 g_flow_divert_in6_udp_usrreqs.pru_disconnect = flow_divert_close;
4833 g_flow_divert_in6_udp_usrreqs.pru_disconnectx = flow_divert_disconnectx;
4834 g_flow_divert_in6_udp_usrreqs.pru_rcvd = flow_divert_rcvd;
4835 g_flow_divert_in6_udp_usrreqs.pru_send = flow_divert_data_out;
4836 g_flow_divert_in6_udp_usrreqs.pru_shutdown = flow_divert_shutdown;
4837 g_flow_divert_in6_udp_usrreqs.pru_sosend_list = pru_sosend_list_notsupp;
4838 g_flow_divert_in6_udp_usrreqs.pru_preconnect = flow_divert_preconnect;
4839
4840 g_flow_divert_in6_udp_protosw.pr_usrreqs = &g_flow_divert_in6_udp_usrreqs;
4841 g_flow_divert_in6_udp_protosw.pr_ctloutput = flow_divert_ctloutput;
4842 /*
4843 * Socket filters shouldn't attach/detach to/from this protosw
4844 * since pr_protosw is to be used instead, which points to the
4845 * real protocol; if they do, it is a bug and we should panic.
4846 */
4847 g_flow_divert_in6_udp_protosw.pr_filter_head.tqh_first =
4848 (struct socket_filter *)(uintptr_t)0xdeadbeefdeadbeef;
4849 g_flow_divert_in6_udp_protosw.pr_filter_head.tqh_last =
4850 (struct socket_filter **)(uintptr_t)0xdeadbeefdeadbeef;
4851
4852 TAILQ_INIT(&g_flow_divert_in_process_group_list);
4853
4854 g_init_result = flow_divert_kctl_init();
4855 if (g_init_result) {
4856 goto done;
4857 }
4858
4859 done:
4860 if (g_init_result != 0) {
4861 if (g_flow_divert_kctl_ref != NULL) {
4862 ctl_deregister(g_flow_divert_kctl_ref);
4863 g_flow_divert_kctl_ref = NULL;
4864 }
4865 }
4866 }
4867