1 /* 2 * Copyright (c) 1994, 1995, 1996 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the Computer Systems 16 * Engineering Group at Lawrence Berkeley Laboratory. 17 * 4. Neither the name of the University nor of the Laboratory may be used 18 * to endorse or promote products derived from this software without 19 * specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef pcap_int_h 35 #define pcap_int_h 36 37 #include <stddef.h> 38 39 #include <signal.h> 40 41 #include <pcap/pcap.h> 42 43 #ifdef MSDOS 44 #include <fcntl.h> 45 #include <io.h> 46 #endif 47 48 #include "varattrs.h" 49 #include "fmtutils.h" 50 51 #include <stdarg.h> 52 53 #include "portability.h" 54 55 #define PCAP_DEBUG {printf(" [%s:%d %s] ", __FILE__, __LINE__, __func__); fflush(stdout);} 56 57 /* 58 * If we're compiling with Visual Studio, make sure we have at least 59 * VS 2015 or later, so we have sufficient C99 support. 60 * 61 * XXX - verify that we have at least C99 support on UN*Xes? 62 * 63 * What about MinGW or various DOS toolchains? We're currently assuming 64 * sufficient C99 support there. 65 */ 66 #if defined(_MSC_VER) 67 /* 68 * Compiler is MSVC. Make sure we have VS 2015 or later. 69 */ 70 #if _MSC_VER < 1900 71 #error "Building libpcap requires VS 2015 or later" 72 #endif 73 #endif 74 75 /* 76 * Version string. 77 * Uses PACKAGE_VERSION from config.h. 78 */ 79 #define PCAP_VERSION_STRING "libpcap version " PACKAGE_VERSION 80 81 #ifdef __cplusplus 82 extern "C" { 83 #endif 84 85 /* 86 * If pcapint_new_api is set, we disable pcap_lookupdev(), because: 87 * 88 * it's not thread-safe, and is marked as deprecated, on all 89 * platforms; 90 * 91 * on Windows, it may return UTF-16LE strings, which the program 92 * might then pass to pcap_create() (or to pcap_open_live(), which 93 * then passes them to pcap_create()), requiring pcap_create() to 94 * check for UTF-16LE strings using a hack, and that hack 1) 95 * *cannot* be 100% reliable and 2) runs the risk of going past the 96 * end of the string. 97 * 98 * We keep it around in legacy mode for compatibility. 99 * 100 * We also disable the aforementioned hack in pcap_create(). 101 */ 102 extern int pcapint_new_api; 103 104 /* 105 * If pcapint_utf_8_mode is set, on Windows we treat strings as UTF-8. 106 * 107 * On UN*Xes, we assume all strings are and should be in UTF-8, regardless 108 * of the setting of this flag. 109 */ 110 extern int pcapint_utf_8_mode; 111 112 /* 113 * Swap byte ordering of unsigned long long timestamp on a big endian 114 * machine. 115 */ 116 #define SWAPLL(ull) ((ull & 0xff00000000000000ULL) >> 56) | \ 117 ((ull & 0x00ff000000000000ULL) >> 40) | \ 118 ((ull & 0x0000ff0000000000ULL) >> 24) | \ 119 ((ull & 0x000000ff00000000ULL) >> 8) | \ 120 ((ull & 0x00000000ff000000ULL) << 8) | \ 121 ((ull & 0x0000000000ff0000ULL) << 24) | \ 122 ((ull & 0x000000000000ff00ULL) << 40) | \ 123 ((ull & 0x00000000000000ffULL) << 56) 124 125 /* 126 * Maximum snapshot length. 127 * 128 * Somewhat arbitrary, but chosen to be: 129 * 130 * 1) big enough for maximum-size Linux loopback packets (65549) 131 * and some USB packets captured with USBPcap: 132 * 133 * https://desowin.org/usbpcap/ 134 * 135 * (> 131072, < 262144) 136 * 137 * and 138 * 139 * 2) small enough not to cause attempts to allocate huge amounts of 140 * memory; some applications might use the snapshot length in a 141 * savefile header to control the size of the buffer they allocate, 142 * so a size of, say, 2^31-1 might not work well. (libpcap uses it 143 * as a hint, but doesn't start out allocating a buffer bigger than 144 * 2 KiB, and grows the buffer as necessary, but not beyond the 145 * per-linktype maximum snapshot length. Other code might naively 146 * use it; we want to avoid writing a too-large snapshot length, 147 * in order not to cause that code problems.) 148 * 149 * We don't enforce this in pcap_set_snaplen(), but we use it internally. 150 */ 151 #define MAXIMUM_SNAPLEN 262144 152 153 /* 154 * Locale-independent macros for testing character types. 155 * These can be passed any integral value, without worrying about, for 156 * example, sign-extending char values, unlike the C macros. 157 */ 158 #define PCAP_ISDIGIT(c) \ 159 ((c) >= '0' && (c) <= '9') 160 #define PCAP_ISXDIGIT(c) \ 161 (((c) >= '0' && (c) <= '9') || \ 162 ((c) >= 'A' && (c) <= 'F') || \ 163 ((c) >= 'a' && (c) <= 'f')) 164 165 struct pcap_opt { 166 char *device; 167 int timeout; /* timeout for buffering */ 168 u_int buffer_size; 169 int promisc; 170 int rfmon; /* monitor mode */ 171 int immediate; /* immediate mode - deliver packets as soon as they arrive */ 172 int nonblock; /* non-blocking mode - don't wait for packets to be delivered, return "no packets available" */ 173 int tstamp_type; 174 int tstamp_precision; 175 176 /* 177 * Platform-dependent options. 178 */ 179 #ifdef __linux__ 180 int protocol; /* protocol to use when creating PF_PACKET socket */ 181 #endif 182 #ifdef _WIN32 183 int nocapture_local;/* disable NPF loopback */ 184 #endif 185 }; 186 187 typedef int (*activate_op_t)(pcap_t *); 188 typedef int (*can_set_rfmon_op_t)(pcap_t *); 189 typedef int (*read_op_t)(pcap_t *, int cnt, pcap_handler, u_char *); 190 typedef int (*next_packet_op_t)(pcap_t *, struct pcap_pkthdr *, u_char **); 191 typedef int (*inject_op_t)(pcap_t *, const void *, int); 192 typedef void (*save_current_filter_op_t)(pcap_t *, const char *); 193 typedef int (*setfilter_op_t)(pcap_t *, struct bpf_program *); 194 typedef int (*setdirection_op_t)(pcap_t *, pcap_direction_t); 195 typedef int (*set_datalink_op_t)(pcap_t *, int); 196 typedef int (*getnonblock_op_t)(pcap_t *); 197 typedef int (*setnonblock_op_t)(pcap_t *, int); 198 typedef int (*stats_op_t)(pcap_t *, struct pcap_stat *); 199 typedef void (*breakloop_op_t)(pcap_t *); 200 #ifdef _WIN32 201 typedef struct pcap_stat *(*stats_ex_op_t)(pcap_t *, int *); 202 typedef int (*setbuff_op_t)(pcap_t *, int); 203 typedef int (*setmode_op_t)(pcap_t *, int); 204 typedef int (*setmintocopy_op_t)(pcap_t *, int); 205 typedef HANDLE (*getevent_op_t)(pcap_t *); 206 typedef int (*oid_get_request_op_t)(pcap_t *, bpf_u_int32, void *, size_t *); 207 typedef int (*oid_set_request_op_t)(pcap_t *, bpf_u_int32, const void *, size_t *); 208 typedef u_int (*sendqueue_transmit_op_t)(pcap_t *, pcap_send_queue *, int); 209 typedef int (*setuserbuffer_op_t)(pcap_t *, int); 210 typedef int (*live_dump_op_t)(pcap_t *, char *, int, int); 211 typedef int (*live_dump_ended_op_t)(pcap_t *, int); 212 typedef PAirpcapHandle (*get_airpcap_handle_op_t)(pcap_t *); 213 #endif 214 typedef void (*cleanup_op_t)(pcap_t *); 215 216 /* 217 * We put all the stuff used in the read code path at the beginning, 218 * to try to keep it together in the same cache line or lines. 219 */ 220 struct pcap { 221 /* 222 * Method to call to read packets on a live capture. 223 */ 224 read_op_t read_op; 225 226 /* 227 * Method to call to read the next packet from a savefile. 228 */ 229 next_packet_op_t next_packet_op; 230 231 #ifdef _WIN32 232 HANDLE handle; 233 #else 234 int fd; 235 #endif /* _WIN32 */ 236 237 /* 238 * Read buffer. 239 */ 240 u_int bufsize; 241 void *buffer; 242 u_char *bp; 243 int cc; 244 245 sig_atomic_t break_loop; /* flag set to force break from packet-reading loop */ 246 247 void *priv; /* private data for methods */ 248 249 #ifdef ENABLE_REMOTE 250 struct pcap_samp rmt_samp; /* parameters related to the sampling process. */ 251 #endif 252 253 int swapped; 254 FILE *rfile; /* null if live capture, non-null if savefile */ 255 u_int fddipad; 256 struct pcap *next; /* list of open pcaps that need stuff cleared on close */ 257 258 /* 259 * File version number; meaningful only for a savefile, but we 260 * keep it here so that apps that (mistakenly) ask for the 261 * version numbers will get the same zero values that they 262 * always did. 263 */ 264 int version_major; 265 int version_minor; 266 267 int snapshot; 268 int linktype; /* Network linktype */ 269 int linktype_ext; /* Extended information stored in the linktype field of a file */ 270 int offset; /* offset for proper alignment */ 271 int activated; /* true if the capture is really started */ 272 int oldstyle; /* if we're opening with pcap_open_live() */ 273 274 struct pcap_opt opt; 275 276 /* 277 * Place holder for pcap_next(). 278 */ 279 u_char *pkt; 280 281 #ifdef _WIN32 282 struct pcap_stat stat; /* used for pcap_stats_ex() */ 283 #endif 284 285 /* We're accepting only packets in this direction/these directions. */ 286 pcap_direction_t direction; 287 288 /* 289 * Flags to affect BPF code generation. 290 */ 291 int bpf_codegen_flags; 292 293 #if !defined(_WIN32) && !defined(MSDOS) 294 int selectable_fd; /* FD on which select()/poll()/epoll_wait()/kevent()/etc. can be done */ 295 296 /* 297 * In case there either is no selectable FD, or there is but 298 * it doesn't necessarily work (e.g., if it doesn't get notified 299 * if the packet capture timeout expires before the buffer 300 * fills up), this points to a timeout that should be used 301 * in select()/poll()/epoll_wait()/kevent() call. The pcap_t should 302 * be put into non-blocking mode, and, if the timeout expires on 303 * the call, an attempt should be made to read packets from all 304 * pcap_t's with a required timeout, and the code must be 305 * prepared not to see any packets from the attempt. 306 */ 307 const struct timeval *required_select_timeout; 308 #endif 309 310 /* 311 * Placeholder for filter code if bpf not in kernel. 312 */ 313 struct bpf_program fcode; 314 315 char errbuf[PCAP_ERRBUF_SIZE + 1]; 316 #ifdef _WIN32 317 char acp_errbuf[PCAP_ERRBUF_SIZE + 1]; /* buffer for local code page error strings */ 318 #endif 319 int dlt_count; 320 u_int *dlt_list; 321 int tstamp_type_count; 322 u_int *tstamp_type_list; 323 int tstamp_precision_count; 324 u_int *tstamp_precision_list; 325 326 struct pcap_pkthdr pcap_header; /* This is needed for the pcap_next_ex() to work */ 327 328 /* 329 * More methods. 330 */ 331 activate_op_t activate_op; 332 can_set_rfmon_op_t can_set_rfmon_op; 333 inject_op_t inject_op; 334 save_current_filter_op_t save_current_filter_op; 335 setfilter_op_t setfilter_op; 336 setdirection_op_t setdirection_op; 337 set_datalink_op_t set_datalink_op; 338 getnonblock_op_t getnonblock_op; 339 setnonblock_op_t setnonblock_op; 340 stats_op_t stats_op; 341 breakloop_op_t breakloop_op; 342 343 /* 344 * Routine to use as callback for pcap_next()/pcap_next_ex(). 345 */ 346 pcap_handler oneshot_callback; 347 348 #ifdef _WIN32 349 /* 350 * These are, at least currently, specific to the Win32 NPF 351 * driver. 352 */ 353 stats_ex_op_t stats_ex_op; 354 setbuff_op_t setbuff_op; 355 setmode_op_t setmode_op; 356 setmintocopy_op_t setmintocopy_op; 357 getevent_op_t getevent_op; 358 oid_get_request_op_t oid_get_request_op; 359 oid_set_request_op_t oid_set_request_op; 360 sendqueue_transmit_op_t sendqueue_transmit_op; 361 setuserbuffer_op_t setuserbuffer_op; 362 live_dump_op_t live_dump_op; 363 live_dump_ended_op_t live_dump_ended_op; 364 get_airpcap_handle_op_t get_airpcap_handle_op; 365 #endif 366 cleanup_op_t cleanup_op; 367 }; 368 369 /* 370 * BPF code generation flags. 371 */ 372 #define BPF_SPECIAL_VLAN_HANDLING 0x00000001 /* special VLAN handling for Linux */ 373 374 /* 375 * User data structure for the one-shot callback used for pcap_next() 376 * and pcap_next_ex(). 377 */ 378 struct oneshot_userdata { 379 struct pcap_pkthdr *hdr; 380 const u_char **pkt; 381 pcap_t *pd; 382 }; 383 384 #ifndef min 385 #define min(a, b) ((a) > (b) ? (b) : (a)) 386 #endif 387 388 int pcapint_offline_read(pcap_t *, int, pcap_handler, u_char *); 389 390 /* 391 * Does the packet count argument to a module's read routine say 392 * "supply packets until you run out of packets"? 393 */ 394 #define PACKET_COUNT_IS_UNLIMITED(count) ((count) <= 0) 395 396 /* 397 * Routines that most pcap implementations can use for non-blocking mode. 398 */ 399 #if !defined(_WIN32) && !defined(MSDOS) 400 int pcapint_getnonblock_fd(pcap_t *); 401 int pcapint_setnonblock_fd(pcap_t *p, int); 402 #endif 403 404 /* 405 * Internal interfaces for "pcap_create()". 406 * 407 * "pcapint_create_interface()" is the routine to do a pcap_create on 408 * a regular network interface. There are multiple implementations 409 * of this, one for each platform type (Linux, BPF, DLPI, etc.), 410 * with the one used chosen by the configure script. 411 * 412 * "pcapint_create_common()" allocates and fills in a pcap_t, for use 413 * by pcap_create routines. 414 */ 415 pcap_t *pcapint_create_interface(const char *, char *); 416 417 /* 418 * This wrapper takes an error buffer pointer and a type to use for the 419 * private data, and calls pcapint_create_common(), passing it the error 420 * buffer pointer, the size for the private data type, in bytes, and the 421 * offset of the private data from the beginning of the structure, in 422 * bytes. 423 */ 424 #define PCAP_CREATE_COMMON(ebuf, type) \ 425 pcapint_create_common(ebuf, \ 426 sizeof (struct { pcap_t __common; type __private; }), \ 427 offsetof (struct { pcap_t __common; type __private; }, __private)) 428 pcap_t *pcapint_create_common(char *, size_t, size_t); 429 int pcapint_do_addexit(pcap_t *); 430 void pcapint_add_to_pcaps_to_close(pcap_t *); 431 void pcapint_remove_from_pcaps_to_close(pcap_t *); 432 void pcapint_cleanup_live_common(pcap_t *); 433 int pcapint_check_activated(pcap_t *); 434 void pcapint_breakloop_common(pcap_t *); 435 436 /* 437 * Internal interfaces for "pcap_findalldevs()". 438 * 439 * A pcap_if_list_t * is a reference to a list of devices. 440 * 441 * A get_if_flags_func is a platform-dependent function called to get 442 * additional interface flags. 443 * 444 * "pcapint_platform_finddevs()" is the platform-dependent routine to 445 * find local network interfaces. 446 * 447 * "pcapint_findalldevs_interfaces()" is a helper to find those interfaces 448 * using the "standard" mechanisms (SIOCGIFCONF, "getifaddrs()", etc.). 449 * 450 * "pcapint_add_dev()" adds an entry to a pcap_if_list_t. 451 * 452 * "pcap_add_any_dev()" adds an entry for the "any" device to a pcap_if_list_t. 453 * 454 * "pcapint_find_dev()" tries to find a device, by name, in a pcap_if_list_t. 455 * 456 * "pcapint_find_or_add_dev()" checks whether a device is already in a 457 * pcap_if_list_t and, if not, adds an entry for it. 458 */ 459 struct pcap_if_list; 460 typedef struct pcap_if_list pcap_if_list_t; 461 typedef int (*get_if_flags_func)(const char *, bpf_u_int32 *, char *); 462 int pcapint_platform_finddevs(pcap_if_list_t *, char *); 463 #if !defined(_WIN32) && !defined(MSDOS) 464 int pcapint_findalldevs_interfaces(pcap_if_list_t *, char *, 465 int (*)(const char *), get_if_flags_func); 466 #endif 467 pcap_if_t *pcapint_find_or_add_dev(pcap_if_list_t *, const char *, bpf_u_int32, 468 get_if_flags_func, const char *, char *); 469 pcap_if_t *pcapint_find_dev(pcap_if_list_t *, const char *); 470 pcap_if_t *pcapint_add_dev(pcap_if_list_t *, const char *, bpf_u_int32, 471 const char *, char *); 472 pcap_if_t *pcap_add_any_dev(pcap_if_list_t *, char *); 473 int pcapint_add_addr_to_dev(pcap_if_t *, struct sockaddr *, size_t, 474 struct sockaddr *, size_t, struct sockaddr *, size_t, 475 struct sockaddr *dstaddr, size_t, char *errbuf); 476 #ifndef _WIN32 477 pcap_if_t *pcapint_find_or_add_if(pcap_if_list_t *, const char *, uint64_t, 478 get_if_flags_func, char *); 479 int pcapint_add_addr_to_if(pcap_if_list_t *, const char *, uint64_t, 480 get_if_flags_func, 481 struct sockaddr *, size_t, struct sockaddr *, size_t, 482 struct sockaddr *, size_t, struct sockaddr *, size_t, char *); 483 #endif 484 485 /* 486 * Internal interfaces for "pcap_open_offline()" and other savefile 487 * I/O routines. 488 * 489 * "pcapint_open_offline_common()" allocates and fills in a pcap_t, for use 490 * by pcap_open_offline routines. 491 * 492 * "pcapint_adjust_snapshot()" adjusts the snapshot to be non-zero and 493 * fit within an int. 494 * 495 * "pcapint_sf_cleanup()" closes the file handle associated with a pcap_t, if 496 * appropriate, and frees all data common to all modules for handling 497 * savefile types. 498 * 499 * "pcapint_charset_fopen()", in UTF-8 mode on Windows, does an fopen() that 500 * treats the pathname as being in UTF-8, rather than the local 501 * code page, on Windows. 502 */ 503 504 /* 505 * This wrapper takes an error buffer pointer and a type to use for the 506 * private data, and calls pcapint_create_common(), passing it the error 507 * buffer pointer, the size for the private data type, in bytes, and the 508 * offset of the private data from the beginning of the structure, in 509 * bytes. 510 */ 511 #define PCAP_OPEN_OFFLINE_COMMON(ebuf, type) \ 512 pcapint_open_offline_common(ebuf, \ 513 sizeof (struct { pcap_t __common; type __private; }), \ 514 offsetof (struct { pcap_t __common; type __private; }, __private)) 515 pcap_t *pcapint_open_offline_common(char *ebuf, size_t total_size, 516 size_t private_data); 517 bpf_u_int32 pcapint_adjust_snapshot(bpf_u_int32 linktype, bpf_u_int32 snaplen); 518 void pcapint_sf_cleanup(pcap_t *p); 519 #ifdef _WIN32 520 FILE *pcapint_charset_fopen(const char *path, const char *mode); 521 #else 522 /* 523 * On other OSes, just use Boring Old fopen(). 524 */ 525 #define pcapint_charset_fopen(path, mode) fopen((path), (mode)) 526 #endif 527 528 /* 529 * Internal interfaces for loading code at run time. 530 */ 531 #ifdef _WIN32 532 #define pcap_code_handle_t HMODULE 533 #define pcap_funcptr_t FARPROC 534 535 pcap_code_handle_t pcapint_load_code(const char *); 536 pcap_funcptr_t pcapint_find_function(pcap_code_handle_t, const char *); 537 #endif 538 539 /* 540 * Internal interfaces for doing user-mode filtering of packets and 541 * validating filter programs. 542 */ 543 /* 544 * Auxiliary data, for use when interpreting a filter intended for the 545 * Linux kernel when the kernel rejects the filter (requiring us to 546 * run it in userland). It contains VLAN tag information. 547 */ 548 struct pcap_bpf_aux_data { 549 u_short vlan_tag_present; 550 u_short vlan_tag; 551 }; 552 553 /* 554 * Filtering routine that takes the auxiliary data as an additional 555 * argument. 556 */ 557 u_int pcapint_filter_with_aux_data(const struct bpf_insn *, 558 const u_char *, u_int, u_int, const struct pcap_bpf_aux_data *); 559 560 /* 561 * Filtering routine that doesn't. 562 */ 563 u_int pcapint_filter(const struct bpf_insn *, const u_char *, u_int, u_int); 564 565 /* 566 * Routine to validate a BPF program. 567 */ 568 int pcapint_validate_filter(const struct bpf_insn *, int); 569 570 /* 571 * Internal interfaces for both "pcap_create()" and routines that 572 * open savefiles. 573 * 574 * "pcapint_oneshot()" is the standard one-shot callback for "pcap_next()" 575 * and "pcap_next_ex()". 576 */ 577 void pcapint_oneshot(u_char *, const struct pcap_pkthdr *, const u_char *); 578 579 int pcapint_install_bpf_program(pcap_t *, struct bpf_program *); 580 581 int pcapint_strcasecmp(const char *, const char *); 582 583 /* 584 * Internal interfaces for pcap_createsrcstr and pcap_parsesrcstr with 585 * the additional bit of information regarding SSL support (rpcap:// vs. 586 * rpcaps://). 587 */ 588 int pcapint_createsrcstr_ex(char *, int, const char *, const char *, 589 const char *, unsigned char, char *); 590 int pcapint_parsesrcstr_ex(const char *, int *, char *, char *, 591 char *, unsigned char *, char *); 592 593 #ifdef YYDEBUG 594 extern int pcap_debug; 595 #endif 596 597 #ifdef __cplusplus 598 } 599 #endif 600 601 #endif 602