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 <signal.h> 38 39 #include <pcap/pcap.h> 40 41 #include "varattrs.h" 42 #include "fmtutils.h" 43 44 /* 45 * Version string. 46 * Uses PACKAGE_VERSION from config.h. 47 */ 48 #define PCAP_VERSION_STRING "libpcap version " PACKAGE_VERSION 49 50 #ifdef __cplusplus 51 extern "C" { 52 #endif 53 54 #ifdef MSDOS 55 #include <fcntl.h> 56 #include <io.h> 57 #endif 58 59 /* 60 * Swap byte ordering of unsigned long long timestamp on a big endian 61 * machine. 62 */ 63 #define SWAPLL(ull) ((ull & 0xff00000000000000ULL) >> 56) | \ 64 ((ull & 0x00ff000000000000ULL) >> 40) | \ 65 ((ull & 0x0000ff0000000000ULL) >> 24) | \ 66 ((ull & 0x000000ff00000000ULL) >> 8) | \ 67 ((ull & 0x00000000ff000000ULL) << 8) | \ 68 ((ull & 0x0000000000ff0000ULL) << 24) | \ 69 ((ull & 0x000000000000ff00ULL) << 40) | \ 70 ((ull & 0x00000000000000ffULL) << 56) 71 72 /* 73 * Maximum snapshot length. 74 * 75 * Somewhat arbitrary, but chosen to be: 76 * 77 * 1) big enough for maximum-size Linux loopback packets (65549) 78 * and some USB packets captured with USBPcap: 79 * 80 * http://desowin.org/usbpcap/ 81 * 82 * (> 131072, < 262144) 83 * 84 * and 85 * 86 * 2) small enough not to cause attempts to allocate huge amounts of 87 * memory; some applications might use the snapshot length in a 88 * savefile header to control the size of the buffer they allocate, 89 * so a size of, say, 2^31-1 might not work well. 90 * 91 * We don't enforce this in pcap_set_snaplen(), but we use it internally. 92 */ 93 #define MAXIMUM_SNAPLEN 262144 94 95 struct pcap_opt { 96 char *device; 97 int timeout; /* timeout for buffering */ 98 u_int buffer_size; 99 int promisc; 100 int rfmon; /* monitor mode */ 101 int immediate; /* immediate mode - deliver packets as soon as they arrive */ 102 int nonblock; /* non-blocking mode - don't wait for packets to be delivered, return "no packets available" */ 103 int tstamp_type; 104 int tstamp_precision; 105 106 /* 107 * Platform-dependent options. 108 */ 109 #ifdef __linux__ 110 int protocol; /* protocol to use when creating PF_PACKET socket */ 111 #endif 112 #ifdef _WIN32 113 int nocapture_local;/* disable NPF loopback */ 114 #endif 115 }; 116 117 typedef int (*activate_op_t)(pcap_t *); 118 typedef int (*can_set_rfmon_op_t)(pcap_t *); 119 typedef int (*read_op_t)(pcap_t *, int cnt, pcap_handler, u_char *); 120 typedef int (*next_packet_op_t)(pcap_t *, struct pcap_pkthdr *, u_char **); 121 typedef int (*inject_op_t)(pcap_t *, const void *, size_t); 122 typedef void (*save_current_filter_op_t)(pcap_t *, const char *); 123 typedef int (*setfilter_op_t)(pcap_t *, struct bpf_program *); 124 typedef int (*setdirection_op_t)(pcap_t *, pcap_direction_t); 125 typedef int (*set_datalink_op_t)(pcap_t *, int); 126 typedef int (*getnonblock_op_t)(pcap_t *); 127 typedef int (*setnonblock_op_t)(pcap_t *, int); 128 typedef int (*stats_op_t)(pcap_t *, struct pcap_stat *); 129 #ifdef _WIN32 130 typedef struct pcap_stat *(*stats_ex_op_t)(pcap_t *, int *); 131 typedef int (*setbuff_op_t)(pcap_t *, int); 132 typedef int (*setmode_op_t)(pcap_t *, int); 133 typedef int (*setmintocopy_op_t)(pcap_t *, int); 134 typedef HANDLE (*getevent_op_t)(pcap_t *); 135 typedef int (*oid_get_request_op_t)(pcap_t *, bpf_u_int32, void *, size_t *); 136 typedef int (*oid_set_request_op_t)(pcap_t *, bpf_u_int32, const void *, size_t *); 137 typedef u_int (*sendqueue_transmit_op_t)(pcap_t *, pcap_send_queue *, int); 138 typedef int (*setuserbuffer_op_t)(pcap_t *, int); 139 typedef int (*live_dump_op_t)(pcap_t *, char *, int, int); 140 typedef int (*live_dump_ended_op_t)(pcap_t *, int); 141 typedef PAirpcapHandle (*get_airpcap_handle_op_t)(pcap_t *); 142 #endif 143 typedef void (*cleanup_op_t)(pcap_t *); 144 145 /* 146 * We put all the stuff used in the read code path at the beginning, 147 * to try to keep it together in the same cache line or lines. 148 */ 149 struct pcap { 150 /* 151 * Method to call to read packets on a live capture. 152 */ 153 read_op_t read_op; 154 155 /* 156 * Method to call to read the next packet from a savefile. 157 */ 158 next_packet_op_t next_packet_op; 159 160 #ifdef _WIN32 161 HANDLE handle; 162 #else 163 int fd; 164 #endif /* _WIN32 */ 165 166 /* 167 * Read buffer. 168 */ 169 u_int bufsize; 170 void *buffer; 171 u_char *bp; 172 int cc; 173 174 sig_atomic_t break_loop; /* flag set to force break from packet-reading loop */ 175 176 void *priv; /* private data for methods */ 177 178 #ifdef ENABLE_REMOTE 179 struct pcap_samp rmt_samp; /* parameters related to the sampling process. */ 180 #endif 181 182 int swapped; 183 FILE *rfile; /* null if live capture, non-null if savefile */ 184 u_int fddipad; 185 struct pcap *next; /* list of open pcaps that need stuff cleared on close */ 186 187 /* 188 * File version number; meaningful only for a savefile, but we 189 * keep it here so that apps that (mistakenly) ask for the 190 * version numbers will get the same zero values that they 191 * always did. 192 */ 193 int version_major; 194 int version_minor; 195 196 int snapshot; 197 int linktype; /* Network linktype */ 198 int linktype_ext; /* Extended information stored in the linktype field of a file */ 199 int tzoff; /* timezone offset */ 200 int offset; /* offset for proper alignment */ 201 int activated; /* true if the capture is really started */ 202 int oldstyle; /* if we're opening with pcap_open_live() */ 203 204 struct pcap_opt opt; 205 206 /* 207 * Place holder for pcap_next(). 208 */ 209 u_char *pkt; 210 211 #ifdef _WIN32 212 struct pcap_stat stat; /* used for pcap_stats_ex() */ 213 #endif 214 215 /* We're accepting only packets in this direction/these directions. */ 216 pcap_direction_t direction; 217 218 /* 219 * Flags to affect BPF code generation. 220 */ 221 int bpf_codegen_flags; 222 223 #if !defined(_WIN32) && !defined(MSDOS) 224 int selectable_fd; /* FD on which select()/poll()/epoll_wait()/kevent()/etc. can be done */ 225 226 /* 227 * In case there either is no selectable FD, or there is but 228 * it doesn't necessarily work (e.g., if it doesn't get notified 229 * if the packet capture timeout expires before the buffer 230 * fills up), this points to a timeout that should be used 231 * in select()/poll()/epoll_wait()/kevent() call. The pcap_t should 232 * be put into non-blocking mode, and, if the timeout expires on 233 * the call, an attempt should be made to read packets from all 234 * pcap_t's with a required timeout, and the code must be 235 * prepared not to see any packets from the attempt. 236 */ 237 struct timeval *required_select_timeout; 238 #endif 239 240 /* 241 * Placeholder for filter code if bpf not in kernel. 242 */ 243 struct bpf_program fcode; 244 245 char errbuf[PCAP_ERRBUF_SIZE + 1]; 246 int dlt_count; 247 u_int *dlt_list; 248 int tstamp_type_count; 249 u_int *tstamp_type_list; 250 int tstamp_precision_count; 251 u_int *tstamp_precision_list; 252 253 struct pcap_pkthdr pcap_header; /* This is needed for the pcap_next_ex() to work */ 254 255 /* 256 * More methods. 257 */ 258 activate_op_t activate_op; 259 can_set_rfmon_op_t can_set_rfmon_op; 260 inject_op_t inject_op; 261 save_current_filter_op_t save_current_filter_op; 262 setfilter_op_t setfilter_op; 263 setdirection_op_t setdirection_op; 264 set_datalink_op_t set_datalink_op; 265 getnonblock_op_t getnonblock_op; 266 setnonblock_op_t setnonblock_op; 267 stats_op_t stats_op; 268 269 /* 270 * Routine to use as callback for pcap_next()/pcap_next_ex(). 271 */ 272 pcap_handler oneshot_callback; 273 274 #ifdef _WIN32 275 /* 276 * These are, at least currently, specific to the Win32 NPF 277 * driver. 278 */ 279 stats_ex_op_t stats_ex_op; 280 setbuff_op_t setbuff_op; 281 setmode_op_t setmode_op; 282 setmintocopy_op_t setmintocopy_op; 283 getevent_op_t getevent_op; 284 oid_get_request_op_t oid_get_request_op; 285 oid_set_request_op_t oid_set_request_op; 286 sendqueue_transmit_op_t sendqueue_transmit_op; 287 setuserbuffer_op_t setuserbuffer_op; 288 live_dump_op_t live_dump_op; 289 live_dump_ended_op_t live_dump_ended_op; 290 get_airpcap_handle_op_t get_airpcap_handle_op; 291 #endif 292 cleanup_op_t cleanup_op; 293 }; 294 295 /* 296 * BPF code generation flags. 297 */ 298 #define BPF_SPECIAL_VLAN_HANDLING 0x00000001 /* special VLAN handling for Linux */ 299 300 /* 301 * This is a timeval as stored in a savefile. 302 * It has to use the same types everywhere, independent of the actual 303 * `struct timeval'; `struct timeval' has 32-bit tv_sec values on some 304 * platforms and 64-bit tv_sec values on other platforms, and writing 305 * out native `struct timeval' values would mean files could only be 306 * read on systems with the same tv_sec size as the system on which 307 * the file was written. 308 */ 309 310 struct pcap_timeval { 311 bpf_int32 tv_sec; /* seconds */ 312 bpf_int32 tv_usec; /* microseconds */ 313 }; 314 315 /* 316 * This is a `pcap_pkthdr' as actually stored in a savefile. 317 * 318 * Do not change the format of this structure, in any way (this includes 319 * changes that only affect the length of fields in this structure), 320 * and do not make the time stamp anything other than seconds and 321 * microseconds (e.g., seconds and nanoseconds). Instead: 322 * 323 * introduce a new structure for the new format; 324 * 325 * send mail to "tcpdump-workers (at) lists.tcpdump.org", requesting 326 * a new magic number for your new capture file format, and, when 327 * you get the new magic number, put it in "savefile.c"; 328 * 329 * use that magic number for save files with the changed record 330 * header; 331 * 332 * make the code in "savefile.c" capable of reading files with 333 * the old record header as well as files with the new record header 334 * (using the magic number to determine the header format). 335 * 336 * Then supply the changes by forking the branch at 337 * 338 * https://github.com/the-tcpdump-group/libpcap/issues 339 * 340 * and issuing a pull request, so that future versions of libpcap and 341 * programs that use it (such as tcpdump) will be able to read your new 342 * capture file format. 343 */ 344 345 struct pcap_sf_pkthdr { 346 struct pcap_timeval ts; /* time stamp */ 347 bpf_u_int32 caplen; /* length of portion present */ 348 bpf_u_int32 len; /* length this packet (off wire) */ 349 }; 350 351 /* 352 * How a `pcap_pkthdr' is actually stored in savefiles written 353 * by some patched versions of libpcap (e.g. the ones in Red 354 * Hat Linux 6.1 and 6.2). 355 * 356 * Do not change the format of this structure, in any way (this includes 357 * changes that only affect the length of fields in this structure). 358 * Instead, introduce a new structure, as per the above. 359 */ 360 361 struct pcap_sf_patched_pkthdr { 362 struct pcap_timeval ts; /* time stamp */ 363 bpf_u_int32 caplen; /* length of portion present */ 364 bpf_u_int32 len; /* length this packet (off wire) */ 365 int index; 366 unsigned short protocol; 367 unsigned char pkt_type; 368 }; 369 370 /* 371 * User data structure for the one-shot callback used for pcap_next() 372 * and pcap_next_ex(). 373 */ 374 struct oneshot_userdata { 375 struct pcap_pkthdr *hdr; 376 const u_char **pkt; 377 pcap_t *pd; 378 }; 379 380 #ifndef min 381 #define min(a, b) ((a) > (b) ? (b) : (a)) 382 #endif 383 384 int pcap_offline_read(pcap_t *, int, pcap_handler, u_char *); 385 386 #include <stdarg.h> 387 388 #include "portability.h" 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 pcap_getnonblock_fd(pcap_t *); 401 int pcap_setnonblock_fd(pcap_t *p, int); 402 #endif 403 404 /* 405 * Internal interfaces for "pcap_create()". 406 * 407 * "pcap_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 * "pcap_create_common()" allocates and fills in a pcap_t, for use 413 * by pcap_create routines. 414 */ 415 pcap_t *pcap_create_interface(const char *, char *); 416 pcap_t *pcap_create_common(char *, size_t); 417 int pcap_do_addexit(pcap_t *); 418 void pcap_add_to_pcaps_to_close(pcap_t *); 419 void pcap_remove_from_pcaps_to_close(pcap_t *); 420 void pcap_cleanup_live_common(pcap_t *); 421 int pcap_check_activated(pcap_t *); 422 423 /* 424 * Internal interfaces for "pcap_findalldevs()". 425 * 426 * A pcap_if_list_t * is a reference to a list of devices. 427 * 428 * A get_if_flags_func is a platform-dependent function called to get 429 * additional interface flags. 430 * 431 * "pcap_platform_finddevs()" is the platform-dependent routine to 432 * find local network interfaces. 433 * 434 * "pcap_findalldevs_interfaces()" is a helper to find those interfaces 435 * using the "standard" mechanisms (SIOCGIFCONF, "getifaddrs()", etc.). 436 * 437 * "add_dev()" adds an entry to a pcap_if_list_t. 438 * 439 * "find_dev()" tries to find a device, by name, in a pcap_if_list_t. 440 * 441 * "find_or_add_dev()" checks whether a device is already in a pcap_if_list_t 442 * and, if not, adds an entry for it. 443 */ 444 struct pcap_if_list; 445 typedef struct pcap_if_list pcap_if_list_t; 446 typedef int (*get_if_flags_func)(const char *, bpf_u_int32 *, char *); 447 int pcap_platform_finddevs(pcap_if_list_t *, char *); 448 #if !defined(_WIN32) && !defined(MSDOS) 449 int pcap_findalldevs_interfaces(pcap_if_list_t *, char *, 450 int (*)(const char *), get_if_flags_func); 451 #endif 452 pcap_if_t *find_or_add_dev(pcap_if_list_t *, const char *, bpf_u_int32, 453 get_if_flags_func, const char *, char *); 454 pcap_if_t *find_dev(pcap_if_list_t *, const char *); 455 pcap_if_t *add_dev(pcap_if_list_t *, const char *, bpf_u_int32, const char *, 456 char *); 457 int add_addr_to_dev(pcap_if_t *, struct sockaddr *, size_t, 458 struct sockaddr *, size_t, struct sockaddr *, size_t, 459 struct sockaddr *dstaddr, size_t, char *errbuf); 460 #ifndef _WIN32 461 pcap_if_t *find_or_add_if(pcap_if_list_t *, const char *, bpf_u_int32, 462 get_if_flags_func, char *); 463 int add_addr_to_if(pcap_if_list_t *, const char *, bpf_u_int32, 464 get_if_flags_func, 465 struct sockaddr *, size_t, struct sockaddr *, size_t, 466 struct sockaddr *, size_t, struct sockaddr *, size_t, char *); 467 #endif 468 469 /* 470 * Internal interfaces for "pcap_open_offline()". 471 * 472 * "pcap_open_offline_common()" allocates and fills in a pcap_t, for use 473 * by pcap_open_offline routines. 474 * 475 * "sf_cleanup()" closes the file handle associated with a pcap_t, if 476 * appropriate, and frees all data common to all modules for handling 477 * savefile types. 478 */ 479 pcap_t *pcap_open_offline_common(char *ebuf, size_t size); 480 void sf_cleanup(pcap_t *p); 481 482 /* 483 * Internal interfaces for both "pcap_create()" and routines that 484 * open savefiles. 485 * 486 * "pcap_oneshot()" is the standard one-shot callback for "pcap_next()" 487 * and "pcap_next_ex()". 488 */ 489 void pcap_oneshot(u_char *, const struct pcap_pkthdr *, const u_char *); 490 491 #ifdef _WIN32 492 void pcap_win32_err_to_str(DWORD, char *); 493 #endif 494 495 int install_bpf_program(pcap_t *, struct bpf_program *); 496 497 int pcap_strcasecmp(const char *, const char *); 498 499 #ifdef YYDEBUG 500 extern int pcap_debug; 501 #endif 502 503 #ifdef __cplusplus 504 } 505 #endif 506 507 #endif 508
