1 /* 2 * Copyright (c) 2013-2019, 2022 Apple Inc. All rights reserved. 3 * 4 * @APPLE_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. Please obtain a copy of the License at 10 * http://www.opensource.apple.com/apsl/ and read it before using this 11 * file. 12 * 13 * The Original Code and all software distributed under the License are 14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 18 * Please see the License for the specific language governing rights and 19 * limitations under the License. 20 * 21 * @APPLE_LICENSE_HEADER_END@ 22 */ 23 24 #ifndef __CONTENT_FILTER_H__ 25 #define __CONTENT_FILTER_H__ 26 27 #include <sys/param.h> 28 #include <sys/types.h> 29 #include <sys/_types/_timeval64.h> 30 #include <sys/socket.h> 31 #include <sys/syslog.h> 32 #include <netinet/in.h> 33 #include <stdint.h> 34 #include <corecrypto/ccsha2.h> 35 36 #ifdef BSD_KERNEL_PRIVATE 37 #include <sys/mbuf.h> 38 #include <sys/socketvar.h> 39 #endif /* BSD_KERNEL_PRIVATE */ 40 41 #ifndef XNU_KERNEL_PRIVATE 42 #include <TargetConditionals.h> 43 #endif 44 45 __BEGIN_DECLS 46 47 #ifdef PRIVATE 48 49 /* 50 * Kernel control name for an instance of a Content Filter 51 * Use CTLIOCGINFO to find out the corresponding kernel control id 52 * to be set in the sc_id field of sockaddr_ctl for connect(2) 53 * Note: the sc_unit is ephemeral 54 */ 55 #define CONTENT_FILTER_CONTROL_NAME "com.apple.content-filter" 56 57 /* 58 * Opaque socket identifier 59 */ 60 typedef uint64_t cfil_sock_id_t; 61 62 #define CFIL_SOCK_ID_NONE UINT64_MAX 63 64 65 /* 66 * CFIL_OPT_NECP_CONTROL_UNIT 67 * To set or get the NECP filter control unit for the kernel control socket 68 * The option level is SYSPROTO_CONTROL 69 */ 70 #define CFIL_OPT_NECP_CONTROL_UNIT 1 /* uint32_t */ 71 72 /* 73 * CFIL_OPT_GET_SOCKET_INFO 74 * To get information about a given socket that is being filtered. 75 */ 76 #define CFIL_OPT_GET_SOCKET_INFO 2 /* uint32_t */ 77 78 /* 79 * CFIL_OPT_PRESERVE_CONNECTIONS 80 * To set or get the preserve-connections setting for the filter 81 */ 82 #define CFIL_OPT_PRESERVE_CONNECTIONS 3 /* uint32_t */ 83 84 /* 85 * struct cfil_opt_sock_info 86 * 87 * Contains information about a socket that is being filtered. 88 */ 89 struct cfil_opt_sock_info { 90 cfil_sock_id_t cfs_sock_id; 91 int cfs_sock_family; /* e.g. PF_INET */ 92 int cfs_sock_type; /* e.g. SOCK_STREAM */ 93 int cfs_sock_protocol; /* e.g. IPPROTO_TCP */ 94 union sockaddr_in_4_6 cfs_local; 95 union sockaddr_in_4_6 cfs_remote; 96 pid_t cfs_pid; 97 pid_t cfs_e_pid; 98 uuid_t cfs_uuid; 99 uuid_t cfs_e_uuid; 100 }; 101 102 /* 103 * How many filter may be active simultaneously 104 */ 105 106 #define CFIL_MAX_FILTER_COUNT 8 107 108 /* 109 * Crypto Support 110 */ 111 #define CFIL_CRYPTO 1 112 #define CFIL_CRYPTO_SIGNATURE_SIZE 32 113 #define CFIL_CRYPTO_DATA_EVENT 1 114 115 typedef uint8_t cfil_crypto_key[CCSHA256_OUTPUT_SIZE]; 116 typedef uint8_t cfil_crypto_signature[CFIL_CRYPTO_SIGNATURE_SIZE]; 117 118 typedef struct cfil_crypto_state { 119 const struct ccdigest_info *digest_info; 120 cfil_crypto_key key; 121 } *cfil_crypto_state_t; 122 123 typedef struct cfil_crypto_data { 124 uuid_t flow_id; 125 u_int64_t sock_id; 126 u_int32_t direction; 127 union sockaddr_in_4_6 remote; 128 union sockaddr_in_4_6 local; 129 u_int32_t socketProtocol; 130 pid_t pid; 131 pid_t effective_pid; 132 uuid_t uuid; 133 uuid_t effective_uuid; 134 u_int64_t byte_count_in; 135 u_int64_t byte_count_out; 136 } *cfil_crypto_data_t; 137 138 /* 139 * Types of messages 140 * 141 * Event messages flow from kernel to user space while action 142 * messages flow in the reverse direction. 143 * A message in entirely represented by a packet sent or received 144 * on a Content Filter kernel control socket. 145 */ 146 #define CFM_TYPE_EVENT 1 /* message from kernel */ 147 #define CFM_TYPE_ACTION 2 /* message to kernel */ 148 149 /* 150 * Operations associated with events from kernel 151 */ 152 #define CFM_OP_SOCKET_ATTACHED 1 /* a socket has been attached */ 153 #define CFM_OP_SOCKET_CLOSED 2 /* a socket is being closed */ 154 #define CFM_OP_DATA_OUT 3 /* data being sent */ 155 #define CFM_OP_DATA_IN 4 /* data being received */ 156 #define CFM_OP_DISCONNECT_OUT 5 /* no more outgoing data */ 157 #define CFM_OP_DISCONNECT_IN 6 /* no more incoming data */ 158 #define CFM_OP_STATS 7 /* periodic stats report(s) */ 159 160 /* 161 * Operations associated with action from filter to kernel 162 */ 163 #define CFM_OP_DATA_UPDATE 16 /* update pass or peek offsets */ 164 #define CFM_OP_DROP 17 /* shutdown socket, no more data */ 165 #define CFM_OP_BLESS_CLIENT 18 /* mark a client flow as already filtered, passes a uuid */ 166 #define CFM_OP_SET_CRYPTO_KEY 19 /* assign client crypto key for message signing */ 167 168 /* 169 * struct cfil_msg_hdr 170 * 171 * Header common to all messages 172 */ 173 struct cfil_msg_hdr { 174 uint32_t cfm_len; /* total length */ 175 uint32_t cfm_version; 176 uint32_t cfm_type; 177 uint32_t cfm_op; 178 cfil_sock_id_t cfm_sock_id; 179 }; 180 181 #define CFM_VERSION_CURRENT 1 182 183 /* 184 * Connection Direction 185 */ 186 #define CFS_CONNECTION_DIR_IN 0 187 #define CFS_CONNECTION_DIR_OUT 1 188 189 #define CFS_REAL_AUDIT_TOKEN 1 190 191 #define CFS_MAX_DOMAIN_NAME_LENGTH 256 192 193 194 /* 195 * struct cfil_msg_sock_attached 196 * 197 * Information about a new socket being attached to the content filter 198 * 199 * Action: No reply is expected as this does not block the creation of the 200 * TCP/IP but timely action must be taken to avoid user noticeable delays. 201 * 202 * Valid Types: CFM_TYPE_EVENT 203 * 204 * Valid Op: CFM_OP_SOCKET_ATTACHED 205 */ 206 struct cfil_msg_sock_attached { 207 struct cfil_msg_hdr cfs_msghdr; 208 int cfs_sock_family; /* e.g. PF_INET */ 209 int cfs_sock_type; /* e.g. SOCK_STREAM */ 210 int cfs_sock_protocol; /* e.g. IPPROTO_TCP */ 211 int cfs_unused; /* padding */ 212 pid_t cfs_pid; 213 pid_t cfs_e_pid; 214 uuid_t cfs_uuid; 215 uuid_t cfs_e_uuid; 216 union sockaddr_in_4_6 cfs_src; 217 union sockaddr_in_4_6 cfs_dst; 218 int cfs_conn_dir; 219 unsigned int cfs_audit_token[8]; /* Must match audit_token_t */ 220 unsigned int cfs_real_audit_token[8]; /* Must match audit_token_t */ 221 cfil_crypto_signature cfs_signature; 222 uint32_t cfs_signature_length; 223 char cfs_remote_domain_name[CFS_MAX_DOMAIN_NAME_LENGTH]; 224 }; 225 226 /* 227 * CFIL data flags 228 */ 229 #define CFD_DATA_FLAG_IP_HEADER 0x00000001 /* Data includes IP header */ 230 231 /* 232 * struct cfil_msg_data_event 233 * 234 * Event for the content fiter to act on a span of data 235 * A data span is described by a pair of offsets over the cumulative 236 * number of bytes sent or received on the socket. 237 * 238 * Action: The event must be acted upon but the filter may buffer 239 * data spans until it has enough content to make a decision. 240 * The action must be timely to avoid user noticeable delays. 241 * 242 * Valid Type: CFM_TYPE_EVENT 243 * 244 * Valid Ops: CFM_OP_DATA_OUT, CFM_OP_DATA_IN 245 */ 246 struct cfil_msg_data_event { 247 struct cfil_msg_hdr cfd_msghdr; 248 union sockaddr_in_4_6 cfc_src; 249 union sockaddr_in_4_6 cfc_dst; 250 uint64_t cfd_start_offset; 251 uint64_t cfd_end_offset; 252 cfil_crypto_signature cfd_signature; 253 uint32_t cfd_signature_length; 254 uint32_t cfd_flags; 255 /* Actual content data immediatly follows */ 256 }; 257 258 #define CFI_MAX_TIME_LOG_ENTRY 6 259 /* 260 * struct cfil_msg_sock_closed 261 * 262 * Information about a socket being closed to the content filter 263 * 264 * Action: No reply is expected as this does not block the closing of the 265 * TCP/IP. 266 * 267 * Valid Types: CFM_TYPE_EVENT 268 * 269 * Valid Op: CFM_OP_SOCKET_CLOSED 270 */ 271 struct cfil_msg_sock_closed { 272 struct cfil_msg_hdr cfc_msghdr; 273 struct timeval64 cfc_first_event; 274 uint32_t cfc_op_list_ctr; 275 uint32_t cfc_op_time[CFI_MAX_TIME_LOG_ENTRY]; /* time interval in microseconds since first event */ 276 unsigned char cfc_op_list[CFI_MAX_TIME_LOG_ENTRY]; 277 uint64_t cfc_byte_inbound_count; 278 uint64_t cfc_byte_outbound_count; 279 #define CFC_CLOSED_EVENT_LADDR 1 280 union sockaddr_in_4_6 cfc_laddr; 281 cfil_crypto_signature cfc_signature; 282 uint32_t cfc_signature_length; 283 } __attribute__((aligned(8))); 284 285 /* 286 * struct cfil_msg_stats_report 287 * 288 * Statistics report for flow(s). 289 * 290 * Action: No reply is expected. 291 * 292 * Valid Types: CFM_TYPE_EVENT 293 * 294 * Valid Op: CFM_OP_STATS 295 */ 296 struct cfil_msg_sock_stats { 297 cfil_sock_id_t cfs_sock_id; 298 uint64_t cfs_byte_inbound_count; 299 uint64_t cfs_byte_outbound_count; 300 union sockaddr_in_4_6 cfs_laddr; 301 } __attribute__((aligned(8))); 302 303 struct cfil_msg_stats_report { 304 struct cfil_msg_hdr cfr_msghdr; 305 uint32_t cfr_count; 306 struct cfil_msg_sock_stats cfr_stats[]; 307 } __attribute__((aligned(8))); 308 309 /* 310 * struct cfil_msg_action 311 * 312 * Valid Type: CFM_TYPE_ACTION 313 * 314 * Valid Ops: CFM_OP_DATA_UPDATE, CFM_OP_DROP 315 * 316 * For CFM_OP_DATA_UPDATE: 317 * 318 * cfa_in_pass_offset and cfa_out_pass_offset indicates how much data is 319 * allowed to pass. A zero value does not modify the corresponding pass offset. 320 * 321 * cfa_in_peek_offset and cfa_out_peek_offset lets the filter specify how much 322 * data it needs to make a decision: the kernel will deliver data up to that 323 * offset (if less than cfa_pass_offset it is ignored). Use CFM_MAX_OFFSET 324 * if you don't value the corresponding peek offset to be updated. 325 */ 326 struct cfil_msg_action { 327 struct cfil_msg_hdr cfa_msghdr; 328 uint64_t cfa_in_pass_offset; 329 uint64_t cfa_in_peek_offset; 330 uint64_t cfa_out_pass_offset; 331 uint64_t cfa_out_peek_offset; 332 uint32_t cfa_stats_frequency; // Statistics frequency in milliseconds 333 }; 334 335 /* 336 * struct cfil_msg_bless_client 337 * 338 * Marks a client UUID as already filtered at a higher level. 339 * 340 * Valid Type: CFM_TYPE_ACTION 341 * 342 * Valid Ops: CFM_OP_BLESS_CLIENT 343 */ 344 struct cfil_msg_bless_client { 345 struct cfil_msg_hdr cfb_msghdr; 346 uuid_t cfb_client_uuid; 347 }; 348 349 /* 350 * struct cfil_msg_set_crypto_key 351 * 352 * Filter assigning client crypto key to CFIL for message signing 353 * 354 * Valid Type: CFM_TYPE_ACTION 355 * 356 * Valid Ops: CFM_OP_SET_CRYPTO_KEY 357 */ 358 struct cfil_msg_set_crypto_key { 359 struct cfil_msg_hdr cfb_msghdr; 360 cfil_crypto_key crypto_key; 361 }; 362 363 #define CFM_MAX_OFFSET UINT64_MAX 364 365 /* 366 * Statistics retrieved via sysctl(3) 367 */ 368 struct cfil_filter_stat { 369 uint32_t cfs_len; 370 uint32_t cfs_filter_id; 371 uint32_t cfs_flags; 372 uint32_t cfs_sock_count; 373 uint32_t cfs_necp_control_unit; 374 }; 375 376 struct cfil_entry_stat { 377 uint32_t ces_len; 378 uint32_t ces_filter_id; 379 uint32_t ces_flags; 380 uint32_t ces_necp_control_unit; 381 struct timeval64 ces_last_event; 382 struct timeval64 ces_last_action; 383 struct cfe_buf_stat { 384 uint64_t cbs_pending_first; 385 uint64_t cbs_pending_last; 386 uint64_t cbs_ctl_first; 387 uint64_t cbs_ctl_last; 388 uint64_t cbs_pass_offset; 389 uint64_t cbs_peek_offset; 390 uint64_t cbs_peeked; 391 } ces_snd, ces_rcv; 392 }; 393 394 struct cfil_sock_stat { 395 uint32_t cfs_len; 396 int cfs_sock_family; 397 int cfs_sock_type; 398 int cfs_sock_protocol; 399 cfil_sock_id_t cfs_sock_id; 400 uint64_t cfs_flags; 401 pid_t cfs_pid; 402 pid_t cfs_e_pid; 403 uuid_t cfs_uuid; 404 uuid_t cfs_e_uuid; 405 struct cfi_buf_stat { 406 uint64_t cbs_pending_first; 407 uint64_t cbs_pending_last; 408 uint64_t cbs_pass_offset; 409 uint64_t cbs_inject_q_len; 410 } cfs_snd, cfs_rcv; 411 struct cfil_entry_stat ces_entries[CFIL_MAX_FILTER_COUNT]; 412 }; 413 414 /* 415 * Global statistics 416 */ 417 struct cfil_stats { 418 int32_t cfs_ctl_connect_ok; 419 int32_t cfs_ctl_connect_fail; 420 int32_t cfs_ctl_disconnect_ok; 421 int32_t cfs_ctl_disconnect_fail; 422 int32_t cfs_ctl_send_ok; 423 int32_t cfs_ctl_send_bad; 424 int32_t cfs_ctl_rcvd_ok; 425 int32_t cfs_ctl_rcvd_bad; 426 int32_t cfs_ctl_rcvd_flow_lift; 427 int32_t cfs_ctl_action_data_update; 428 int32_t cfs_ctl_action_drop; 429 int32_t cfs_ctl_action_bad_op; 430 int32_t cfs_ctl_action_bad_len; 431 432 int32_t cfs_sock_id_not_found; 433 434 int32_t cfs_cfi_alloc_ok; 435 int32_t cfs_cfi_alloc_fail; 436 437 int32_t cfs_sock_userspace_only; 438 int32_t cfs_sock_attach_in_vain; 439 int32_t cfs_sock_attach_already; 440 int32_t cfs_sock_attach_no_mem; 441 int32_t cfs_sock_attach_failed; 442 int32_t cfs_sock_attached; 443 int32_t cfs_sock_detached; 444 445 int32_t cfs_attach_event_ok; 446 int32_t cfs_attach_event_flow_control; 447 int32_t cfs_attach_event_fail; 448 449 int32_t cfs_closed_event_ok; 450 int32_t cfs_closed_event_flow_control; 451 int32_t cfs_closed_event_fail; 452 453 int32_t cfs_data_event_ok; 454 int32_t cfs_data_event_flow_control; 455 int32_t cfs_data_event_fail; 456 457 int32_t cfs_stats_event_ok; 458 int32_t cfs_stats_event_flow_control; 459 int32_t cfs_stats_event_fail; 460 461 int32_t cfs_disconnect_in_event_ok; 462 int32_t cfs_disconnect_out_event_ok; 463 int32_t cfs_disconnect_event_flow_control; 464 int32_t cfs_disconnect_event_fail; 465 466 int32_t cfs_ctl_q_not_started; 467 468 int32_t cfs_close_wait; 469 int32_t cfs_close_wait_timeout; 470 471 int32_t cfs_flush_in_drop; 472 int32_t cfs_flush_out_drop; 473 int32_t cfs_flush_in_close; 474 int32_t cfs_flush_out_close; 475 int32_t cfs_flush_in_free; 476 int32_t cfs_flush_out_free; 477 478 int32_t cfs_inject_q_nomem; 479 int32_t cfs_inject_q_nobufs; 480 int32_t cfs_inject_q_detached; 481 int32_t cfs_inject_q_in_fail; 482 int32_t cfs_inject_q_out_fail; 483 484 int32_t cfs_inject_q_in_retry; 485 int32_t cfs_inject_q_out_retry; 486 487 int32_t cfs_data_in_control; 488 int32_t cfs_data_in_oob; 489 int32_t cfs_data_out_control; 490 int32_t cfs_data_out_oob; 491 492 int64_t cfs_ctl_q_in_enqueued __attribute__((aligned(8))); 493 int64_t cfs_ctl_q_out_enqueued __attribute__((aligned(8))); 494 int64_t cfs_ctl_q_in_peeked __attribute__((aligned(8))); 495 int64_t cfs_ctl_q_out_peeked __attribute__((aligned(8))); 496 497 int64_t cfs_pending_q_in_enqueued __attribute__((aligned(8))); 498 int64_t cfs_pending_q_out_enqueued __attribute__((aligned(8))); 499 500 int64_t cfs_inject_q_in_enqueued __attribute__((aligned(8))); 501 int64_t cfs_inject_q_out_enqueued __attribute__((aligned(8))); 502 int64_t cfs_inject_q_in_passed __attribute__((aligned(8))); 503 int64_t cfs_inject_q_out_passed __attribute__((aligned(8))); 504 }; 505 #endif /* PRIVATE */ 506 507 #ifdef BSD_KERNEL_PRIVATE 508 509 #define M_SKIPCFIL M_PROTO5 510 511 #define CFIL_DGRAM_FILTERED(so) ((so->so_flags & SOF_CONTENT_FILTER) && (so->so_flow_db != NULL)) 512 513 extern int cfil_log_level; 514 515 #define CFIL_LOG(level, fmt, ...) \ 516 do { \ 517 if (cfil_log_level >= level) \ 518 printf("%s:%d " fmt "\n",\ 519 __FUNCTION__, __LINE__, ##__VA_ARGS__); \ 520 } while (0) 521 522 523 extern void cfil_register_m_tag(void); 524 525 extern void cfil_init(void); 526 527 extern boolean_t cfil_filter_present(void); 528 extern boolean_t cfil_sock_connected_pending_verdict(struct socket *so); 529 extern boolean_t cfil_sock_is_dead(struct socket *so); 530 extern boolean_t cfil_sock_tcp_add_time_wait(struct socket *so); 531 extern errno_t cfil_sock_attach(struct socket *so, 532 struct sockaddr *local, struct sockaddr *remote, int dir); 533 extern errno_t cfil_sock_detach(struct socket *so); 534 535 extern int cfil_sock_data_out(struct socket *so, struct sockaddr *to, 536 struct mbuf *data, struct mbuf *control, 537 uint32_t flags, struct soflow_hash_entry *); 538 extern int cfil_sock_data_in(struct socket *so, struct sockaddr *from, 539 struct mbuf *data, struct mbuf *control, 540 uint32_t flags, struct soflow_hash_entry *); 541 542 extern int cfil_sock_shutdown(struct socket *so, int *how); 543 extern void cfil_sock_is_closed(struct socket *so); 544 extern void cfil_sock_notify_shutdown(struct socket *so, int how); 545 extern void cfil_sock_close_wait(struct socket *so); 546 547 extern boolean_t cfil_sock_data_pending(struct sockbuf *sb); 548 extern int cfil_sock_data_space(struct sockbuf *sb); 549 extern void cfil_sock_buf_update(struct sockbuf *sb); 550 551 extern cfil_sock_id_t cfil_sock_id_from_socket(struct socket *so); 552 extern cfil_sock_id_t cfil_sock_id_from_datagram_socket(struct socket *so, struct sockaddr *local, struct sockaddr *remote); 553 554 extern struct m_tag *cfil_dgram_get_socket_state(struct mbuf *m, uint32_t *state_change_cnt, 555 uint32_t *options, struct sockaddr **faddr, int *inp_flags); 556 extern boolean_t cfil_dgram_peek_socket_state(struct mbuf *m, int *inp_flags); 557 558 #endif /* BSD_KERNEL_PRIVATE */ 559 560 __END_DECLS 561 562 #endif /* __CONTENT_FILTER_H__ */ 563