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 #define CFIL_DATA_HAS_DELEGATED_PID 1 231 /* 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 pid_t cfd_delegated_pid; 256 unsigned int cfd_delegated_audit_token[8]; 257 /* Actual content data immediatly follows */ 258 }; 259 260 #define CFI_MAX_TIME_LOG_ENTRY 6 261 /* 262 * struct cfil_msg_sock_closed 263 * 264 * Information about a socket being closed to the content filter 265 * 266 * Action: No reply is expected as this does not block the closing of the 267 * TCP/IP. 268 * 269 * Valid Types: CFM_TYPE_EVENT 270 * 271 * Valid Op: CFM_OP_SOCKET_CLOSED 272 */ 273 struct cfil_msg_sock_closed { 274 struct cfil_msg_hdr cfc_msghdr; 275 struct timeval64 cfc_first_event; 276 uint32_t cfc_op_list_ctr; 277 uint32_t cfc_op_time[CFI_MAX_TIME_LOG_ENTRY]; /* time interval in microseconds since first event */ 278 unsigned char cfc_op_list[CFI_MAX_TIME_LOG_ENTRY]; 279 uint64_t cfc_byte_inbound_count; 280 uint64_t cfc_byte_outbound_count; 281 #define CFC_CLOSED_EVENT_LADDR 1 282 union sockaddr_in_4_6 cfc_laddr; 283 cfil_crypto_signature cfc_signature; 284 uint32_t cfc_signature_length; 285 } __attribute__((aligned(8))); 286 287 /* 288 * struct cfil_msg_stats_report 289 * 290 * Statistics report for flow(s). 291 * 292 * Action: No reply is expected. 293 * 294 * Valid Types: CFM_TYPE_EVENT 295 * 296 * Valid Op: CFM_OP_STATS 297 */ 298 struct cfil_msg_sock_stats { 299 cfil_sock_id_t cfs_sock_id; 300 uint64_t cfs_byte_inbound_count; 301 uint64_t cfs_byte_outbound_count; 302 union sockaddr_in_4_6 cfs_laddr; 303 } __attribute__((aligned(8))); 304 305 struct cfil_msg_stats_report { 306 struct cfil_msg_hdr cfr_msghdr; 307 uint32_t cfr_count; 308 struct cfil_msg_sock_stats cfr_stats[]; 309 } __attribute__((aligned(8))); 310 311 /* 312 * struct cfil_msg_action 313 * 314 * Valid Type: CFM_TYPE_ACTION 315 * 316 * Valid Ops: CFM_OP_DATA_UPDATE, CFM_OP_DROP 317 * 318 * For CFM_OP_DATA_UPDATE: 319 * 320 * cfa_in_pass_offset and cfa_out_pass_offset indicates how much data is 321 * allowed to pass. A zero value does not modify the corresponding pass offset. 322 * 323 * cfa_in_peek_offset and cfa_out_peek_offset lets the filter specify how much 324 * data it needs to make a decision: the kernel will deliver data up to that 325 * offset (if less than cfa_pass_offset it is ignored). Use CFM_MAX_OFFSET 326 * if you don't value the corresponding peek offset to be updated. 327 */ 328 struct cfil_msg_action { 329 struct cfil_msg_hdr cfa_msghdr; 330 uint64_t cfa_in_pass_offset; 331 uint64_t cfa_in_peek_offset; 332 uint64_t cfa_out_pass_offset; 333 uint64_t cfa_out_peek_offset; 334 uint32_t cfa_stats_frequency; // Statistics frequency in milliseconds 335 }; 336 337 /* 338 * struct cfil_msg_bless_client 339 * 340 * Marks a client UUID as already filtered at a higher level. 341 * 342 * Valid Type: CFM_TYPE_ACTION 343 * 344 * Valid Ops: CFM_OP_BLESS_CLIENT 345 */ 346 struct cfil_msg_bless_client { 347 struct cfil_msg_hdr cfb_msghdr; 348 uuid_t cfb_client_uuid; 349 }; 350 351 /* 352 * struct cfil_msg_set_crypto_key 353 * 354 * Filter assigning client crypto key to CFIL for message signing 355 * 356 * Valid Type: CFM_TYPE_ACTION 357 * 358 * Valid Ops: CFM_OP_SET_CRYPTO_KEY 359 */ 360 struct cfil_msg_set_crypto_key { 361 struct cfil_msg_hdr cfb_msghdr; 362 cfil_crypto_key crypto_key; 363 }; 364 365 #define CFM_MAX_OFFSET UINT64_MAX 366 367 /* 368 * Statistics retrieved via sysctl(3) 369 */ 370 struct cfil_filter_stat { 371 uint32_t cfs_len; 372 uint32_t cfs_filter_id; 373 uint32_t cfs_flags; 374 uint32_t cfs_sock_count; 375 uint32_t cfs_necp_control_unit; 376 }; 377 378 struct cfil_entry_stat { 379 uint32_t ces_len; 380 uint32_t ces_filter_id; 381 uint32_t ces_flags; 382 uint32_t ces_necp_control_unit; 383 struct timeval64 ces_last_event; 384 struct timeval64 ces_last_action; 385 struct cfe_buf_stat { 386 uint64_t cbs_pending_first; 387 uint64_t cbs_pending_last; 388 uint64_t cbs_ctl_first; 389 uint64_t cbs_ctl_last; 390 uint64_t cbs_pass_offset; 391 uint64_t cbs_peek_offset; 392 uint64_t cbs_peeked; 393 } ces_snd, ces_rcv; 394 }; 395 396 struct cfil_sock_stat { 397 uint32_t cfs_len; 398 int cfs_sock_family; 399 int cfs_sock_type; 400 int cfs_sock_protocol; 401 cfil_sock_id_t cfs_sock_id; 402 uint64_t cfs_flags; 403 pid_t cfs_pid; 404 pid_t cfs_e_pid; 405 uuid_t cfs_uuid; 406 uuid_t cfs_e_uuid; 407 struct cfi_buf_stat { 408 uint64_t cbs_pending_first; 409 uint64_t cbs_pending_last; 410 uint64_t cbs_pass_offset; 411 uint64_t cbs_inject_q_len; 412 } cfs_snd, cfs_rcv; 413 struct cfil_entry_stat ces_entries[CFIL_MAX_FILTER_COUNT]; 414 }; 415 416 /* 417 * Global statistics 418 */ 419 struct cfil_stats { 420 int32_t cfs_ctl_connect_ok; 421 int32_t cfs_ctl_connect_fail; 422 int32_t cfs_ctl_disconnect_ok; 423 int32_t cfs_ctl_disconnect_fail; 424 int32_t cfs_ctl_send_ok; 425 int32_t cfs_ctl_send_bad; 426 int32_t cfs_ctl_rcvd_ok; 427 int32_t cfs_ctl_rcvd_bad; 428 int32_t cfs_ctl_rcvd_flow_lift; 429 int32_t cfs_ctl_action_data_update; 430 int32_t cfs_ctl_action_drop; 431 int32_t cfs_ctl_action_bad_op; 432 int32_t cfs_ctl_action_bad_len; 433 434 int32_t cfs_sock_id_not_found; 435 436 int32_t cfs_cfi_alloc_ok; 437 int32_t cfs_cfi_alloc_fail; 438 439 int32_t cfs_sock_userspace_only; 440 int32_t cfs_sock_attach_in_vain; 441 int32_t cfs_sock_attach_already; 442 int32_t cfs_sock_attach_no_mem; 443 int32_t cfs_sock_attach_failed; 444 int32_t cfs_sock_attached; 445 int32_t cfs_sock_detached; 446 447 int32_t cfs_attach_event_ok; 448 int32_t cfs_attach_event_flow_control; 449 int32_t cfs_attach_event_fail; 450 451 int32_t cfs_closed_event_ok; 452 int32_t cfs_closed_event_flow_control; 453 int32_t cfs_closed_event_fail; 454 455 int32_t cfs_data_event_ok; 456 int32_t cfs_data_event_flow_control; 457 int32_t cfs_data_event_fail; 458 459 int32_t cfs_stats_event_ok; 460 int32_t cfs_stats_event_flow_control; 461 int32_t cfs_stats_event_fail; 462 463 int32_t cfs_disconnect_in_event_ok; 464 int32_t cfs_disconnect_out_event_ok; 465 int32_t cfs_disconnect_event_flow_control; 466 int32_t cfs_disconnect_event_fail; 467 468 int32_t cfs_ctl_q_not_started; 469 470 int32_t cfs_close_wait; 471 int32_t cfs_close_wait_timeout; 472 473 int32_t cfs_flush_in_drop; 474 int32_t cfs_flush_out_drop; 475 int32_t cfs_flush_in_close; 476 int32_t cfs_flush_out_close; 477 int32_t cfs_flush_in_free; 478 int32_t cfs_flush_out_free; 479 480 int32_t cfs_inject_q_nomem; 481 int32_t cfs_inject_q_nobufs; 482 int32_t cfs_inject_q_detached; 483 int32_t cfs_inject_q_in_fail; 484 int32_t cfs_inject_q_out_fail; 485 486 int32_t cfs_inject_q_in_retry; 487 int32_t cfs_inject_q_out_retry; 488 489 int32_t cfs_data_in_control; 490 int32_t cfs_data_in_oob; 491 int32_t cfs_data_out_control; 492 int32_t cfs_data_out_oob; 493 494 int64_t cfs_ctl_q_in_enqueued __attribute__((aligned(8))); 495 int64_t cfs_ctl_q_out_enqueued __attribute__((aligned(8))); 496 int64_t cfs_ctl_q_in_peeked __attribute__((aligned(8))); 497 int64_t cfs_ctl_q_out_peeked __attribute__((aligned(8))); 498 499 int64_t cfs_pending_q_in_enqueued __attribute__((aligned(8))); 500 int64_t cfs_pending_q_out_enqueued __attribute__((aligned(8))); 501 502 int64_t cfs_inject_q_in_enqueued __attribute__((aligned(8))); 503 int64_t cfs_inject_q_out_enqueued __attribute__((aligned(8))); 504 int64_t cfs_inject_q_in_passed __attribute__((aligned(8))); 505 int64_t cfs_inject_q_out_passed __attribute__((aligned(8))); 506 }; 507 #endif /* PRIVATE */ 508 509 #ifdef BSD_KERNEL_PRIVATE 510 511 #define M_SKIPCFIL M_PROTO5 512 513 extern uint32_t cfil_active_count; 514 /* 515 * Check if flows on socket should be filtered 516 */ 517 #define CFIL_DGRAM_HAS_FILTERED_FLOWS(so) ((so->so_flags & SOF_CONTENT_FILTER) && (so->so_flow_db != NULL)) 518 #define CFIL_DGRAM_FILTERED(so) (!IS_TCP(so) && (cfil_active_count > 0) && (CFIL_DGRAM_HAS_FILTERED_FLOWS(so) || necp_socket_get_content_filter_control_unit(so))) 519 520 extern int cfil_log_level; 521 522 #define CFIL_LOG(level, fmt, ...) \ 523 do { \ 524 if (cfil_log_level >= level) \ 525 printf("%s:%d " fmt "\n",\ 526 __FUNCTION__, __LINE__, ##__VA_ARGS__); \ 527 } while (0) 528 529 530 extern void cfil_register_m_tag(void); 531 532 extern void cfil_init(void); 533 534 extern boolean_t cfil_filter_present(void); 535 extern boolean_t cfil_sock_connected_pending_verdict(struct socket *so); 536 extern boolean_t cfil_sock_is_dead(struct socket *so); 537 extern boolean_t cfil_sock_tcp_add_time_wait(struct socket *so); 538 extern errno_t cfil_sock_attach(struct socket *so, 539 struct sockaddr *local, struct sockaddr *remote, int dir); 540 extern errno_t cfil_sock_detach(struct socket *so); 541 542 extern int cfil_sock_data_out(struct socket *so, struct sockaddr *to, 543 struct mbuf *data, struct mbuf *control, 544 uint32_t flags, struct soflow_hash_entry *); 545 extern int cfil_sock_data_in(struct socket *so, struct sockaddr *from, 546 struct mbuf *data, struct mbuf *control, 547 uint32_t flags, struct soflow_hash_entry *); 548 549 extern int cfil_sock_shutdown(struct socket *so, int *how); 550 extern void cfil_sock_is_closed(struct socket *so); 551 extern void cfil_sock_notify_shutdown(struct socket *so, int how); 552 extern void cfil_sock_close_wait(struct socket *so); 553 554 extern boolean_t cfil_sock_data_pending(struct sockbuf *sb); 555 extern int cfil_sock_data_space(struct sockbuf *sb); 556 extern void cfil_sock_buf_update(struct sockbuf *sb); 557 558 extern cfil_sock_id_t cfil_sock_id_from_socket(struct socket *so); 559 extern cfil_sock_id_t cfil_sock_id_from_datagram_socket(struct socket *so, struct sockaddr *local, struct sockaddr *remote); 560 561 extern struct m_tag *cfil_dgram_get_socket_state(struct mbuf *m, uint32_t *state_change_cnt, 562 uint32_t *options, struct sockaddr **faddr, int *inp_flags); 563 extern boolean_t cfil_dgram_peek_socket_state(struct mbuf *m, int *inp_flags); 564 565 #endif /* BSD_KERNEL_PRIVATE */ 566 567 __END_DECLS 568 569 #endif /* __CONTENT_FILTER_H__ */ 570