pcap-int.h 16 KB

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  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. #ifndef pcap_int_h
  34. #define pcap_int_h
  35. #include <signal.h>
  36. #include <pcap/pcap.h>
  37. #include "varattrs.h"
  38. #include "fmtutils.h"
  39. /*
  40. * Version string.
  41. * Uses PACKAGE_VERSION from config.h.
  42. */
  43. #define PCAP_VERSION_STRING "libpcap version " PACKAGE_VERSION
  44. #ifdef __cplusplus
  45. extern "C" {
  46. #endif
  47. #ifdef MSDOS
  48. #include <fcntl.h>
  49. #include <io.h>
  50. #endif
  51. /*
  52. * Swap byte ordering of unsigned long long timestamp on a big endian
  53. * machine.
  54. */
  55. #define SWAPLL(ull) ((ull & 0xff00000000000000ULL) >> 56) | \
  56. ((ull & 0x00ff000000000000ULL) >> 40) | \
  57. ((ull & 0x0000ff0000000000ULL) >> 24) | \
  58. ((ull & 0x000000ff00000000ULL) >> 8) | \
  59. ((ull & 0x00000000ff000000ULL) << 8) | \
  60. ((ull & 0x0000000000ff0000ULL) << 24) | \
  61. ((ull & 0x000000000000ff00ULL) << 40) | \
  62. ((ull & 0x00000000000000ffULL) << 56)
  63. /*
  64. * Maximum snapshot length.
  65. *
  66. * Somewhat arbitrary, but chosen to be:
  67. *
  68. * 1) big enough for maximum-size Linux loopback packets (65549)
  69. * and some USB packets captured with USBPcap:
  70. *
  71. * http://desowin.org/usbpcap/
  72. *
  73. * (> 131072, < 262144)
  74. *
  75. * and
  76. *
  77. * 2) small enough not to cause attempts to allocate huge amounts of
  78. * memory; some applications might use the snapshot length in a
  79. * savefile header to control the size of the buffer they allocate,
  80. * so a size of, say, 2^31-1 might not work well.
  81. *
  82. * We don't enforce this in pcap_set_snaplen(), but we use it internally.
  83. */
  84. #define MAXIMUM_SNAPLEN 262144
  85. struct pcap_opt {
  86. char *device;
  87. int timeout; /* timeout for buffering */
  88. u_int buffer_size;
  89. int promisc;
  90. int rfmon; /* monitor mode */
  91. int immediate; /* immediate mode - deliver packets as soon as they arrive */
  92. int nonblock; /* non-blocking mode - don't wait for packets to be delivered, return "no packets available" */
  93. int tstamp_type;
  94. int tstamp_precision;
  95. /*
  96. * Platform-dependent options.
  97. */
  98. #ifdef __linux__
  99. int protocol; /* protocol to use when creating PF_PACKET socket */
  100. #endif
  101. #ifdef _WIN32
  102. int nocapture_local;/* disable NPF loopback */
  103. #endif
  104. };
  105. typedef int (*activate_op_t)(pcap_t *);
  106. typedef int (*can_set_rfmon_op_t)(pcap_t *);
  107. typedef int (*read_op_t)(pcap_t *, int cnt, pcap_handler, u_char *);
  108. typedef int (*next_packet_op_t)(pcap_t *, struct pcap_pkthdr *, u_char **);
  109. typedef int (*inject_op_t)(pcap_t *, const void *, size_t);
  110. typedef void (*save_current_filter_op_t)(pcap_t *, const char *);
  111. typedef int (*setfilter_op_t)(pcap_t *, struct bpf_program *);
  112. typedef int (*setdirection_op_t)(pcap_t *, pcap_direction_t);
  113. typedef int (*set_datalink_op_t)(pcap_t *, int);
  114. typedef int (*getnonblock_op_t)(pcap_t *);
  115. typedef int (*setnonblock_op_t)(pcap_t *, int);
  116. typedef int (*stats_op_t)(pcap_t *, struct pcap_stat *);
  117. #ifdef _WIN32
  118. typedef struct pcap_stat *(*stats_ex_op_t)(pcap_t *, int *);
  119. typedef int (*setbuff_op_t)(pcap_t *, int);
  120. typedef int (*setmode_op_t)(pcap_t *, int);
  121. typedef int (*setmintocopy_op_t)(pcap_t *, int);
  122. typedef HANDLE (*getevent_op_t)(pcap_t *);
  123. typedef int (*oid_get_request_op_t)(pcap_t *, bpf_u_int32, void *, size_t *);
  124. typedef int (*oid_set_request_op_t)(pcap_t *, bpf_u_int32, const void *, size_t *);
  125. typedef u_int (*sendqueue_transmit_op_t)(pcap_t *, pcap_send_queue *, int);
  126. typedef int (*setuserbuffer_op_t)(pcap_t *, int);
  127. typedef int (*live_dump_op_t)(pcap_t *, char *, int, int);
  128. typedef int (*live_dump_ended_op_t)(pcap_t *, int);
  129. typedef PAirpcapHandle (*get_airpcap_handle_op_t)(pcap_t *);
  130. #endif
  131. typedef void (*cleanup_op_t)(pcap_t *);
  132. /*
  133. * We put all the stuff used in the read code path at the beginning,
  134. * to try to keep it together in the same cache line or lines.
  135. */
  136. struct pcap {
  137. /*
  138. * Method to call to read packets on a live capture.
  139. */
  140. read_op_t read_op;
  141. /*
  142. * Method to call to read the next packet from a savefile.
  143. */
  144. next_packet_op_t next_packet_op;
  145. #ifdef _WIN32
  146. HANDLE handle;
  147. #else
  148. int fd;
  149. #endif /* _WIN32 */
  150. /*
  151. * Read buffer.
  152. */
  153. u_int bufsize;
  154. void *buffer;
  155. u_char *bp;
  156. int cc;
  157. sig_atomic_t break_loop; /* flag set to force break from packet-reading loop */
  158. void *priv; /* private data for methods */
  159. #ifdef ENABLE_REMOTE
  160. struct pcap_samp rmt_samp; /* parameters related to the sampling process. */
  161. #endif
  162. int swapped;
  163. FILE *rfile; /* null if live capture, non-null if savefile */
  164. u_int fddipad;
  165. struct pcap *next; /* list of open pcaps that need stuff cleared on close */
  166. /*
  167. * File version number; meaningful only for a savefile, but we
  168. * keep it here so that apps that (mistakenly) ask for the
  169. * version numbers will get the same zero values that they
  170. * always did.
  171. */
  172. int version_major;
  173. int version_minor;
  174. int snapshot;
  175. int linktype; /* Network linktype */
  176. int linktype_ext; /* Extended information stored in the linktype field of a file */
  177. int tzoff; /* timezone offset */
  178. int offset; /* offset for proper alignment */
  179. int activated; /* true if the capture is really started */
  180. int oldstyle; /* if we're opening with pcap_open_live() */
  181. struct pcap_opt opt;
  182. /*
  183. * Place holder for pcap_next().
  184. */
  185. u_char *pkt;
  186. #ifdef _WIN32
  187. struct pcap_stat stat; /* used for pcap_stats_ex() */
  188. #endif
  189. /* We're accepting only packets in this direction/these directions. */
  190. pcap_direction_t direction;
  191. /*
  192. * Flags to affect BPF code generation.
  193. */
  194. int bpf_codegen_flags;
  195. #if !defined(_WIN32) && !defined(MSDOS)
  196. int selectable_fd; /* FD on which select()/poll()/epoll_wait()/kevent()/etc. can be done */
  197. /*
  198. * In case there either is no selectable FD, or there is but
  199. * it doesn't necessarily work (e.g., if it doesn't get notified
  200. * if the packet capture timeout expires before the buffer
  201. * fills up), this points to a timeout that should be used
  202. * in select()/poll()/epoll_wait()/kevent() call. The pcap_t should
  203. * be put into non-blocking mode, and, if the timeout expires on
  204. * the call, an attempt should be made to read packets from all
  205. * pcap_t's with a required timeout, and the code must be
  206. * prepared not to see any packets from the attempt.
  207. */
  208. struct timeval *required_select_timeout;
  209. #endif
  210. /*
  211. * Placeholder for filter code if bpf not in kernel.
  212. */
  213. struct bpf_program fcode;
  214. char errbuf[PCAP_ERRBUF_SIZE + 1];
  215. int dlt_count;
  216. u_int *dlt_list;
  217. int tstamp_type_count;
  218. u_int *tstamp_type_list;
  219. int tstamp_precision_count;
  220. u_int *tstamp_precision_list;
  221. struct pcap_pkthdr pcap_header; /* This is needed for the pcap_next_ex() to work */
  222. /*
  223. * More methods.
  224. */
  225. activate_op_t activate_op;
  226. can_set_rfmon_op_t can_set_rfmon_op;
  227. inject_op_t inject_op;
  228. save_current_filter_op_t save_current_filter_op;
  229. setfilter_op_t setfilter_op;
  230. setdirection_op_t setdirection_op;
  231. set_datalink_op_t set_datalink_op;
  232. getnonblock_op_t getnonblock_op;
  233. setnonblock_op_t setnonblock_op;
  234. stats_op_t stats_op;
  235. /*
  236. * Routine to use as callback for pcap_next()/pcap_next_ex().
  237. */
  238. pcap_handler oneshot_callback;
  239. #ifdef _WIN32
  240. /*
  241. * These are, at least currently, specific to the Win32 NPF
  242. * driver.
  243. */
  244. stats_ex_op_t stats_ex_op;
  245. setbuff_op_t setbuff_op;
  246. setmode_op_t setmode_op;
  247. setmintocopy_op_t setmintocopy_op;
  248. getevent_op_t getevent_op;
  249. oid_get_request_op_t oid_get_request_op;
  250. oid_set_request_op_t oid_set_request_op;
  251. sendqueue_transmit_op_t sendqueue_transmit_op;
  252. setuserbuffer_op_t setuserbuffer_op;
  253. live_dump_op_t live_dump_op;
  254. live_dump_ended_op_t live_dump_ended_op;
  255. get_airpcap_handle_op_t get_airpcap_handle_op;
  256. #endif
  257. cleanup_op_t cleanup_op;
  258. };
  259. /*
  260. * BPF code generation flags.
  261. */
  262. #define BPF_SPECIAL_VLAN_HANDLING 0x00000001 /* special VLAN handling for Linux */
  263. /*
  264. * This is a timeval as stored in a savefile.
  265. * It has to use the same types everywhere, independent of the actual
  266. * `struct timeval'; `struct timeval' has 32-bit tv_sec values on some
  267. * platforms and 64-bit tv_sec values on other platforms, and writing
  268. * out native `struct timeval' values would mean files could only be
  269. * read on systems with the same tv_sec size as the system on which
  270. * the file was written.
  271. */
  272. struct pcap_timeval {
  273. bpf_int32 tv_sec; /* seconds */
  274. bpf_int32 tv_usec; /* microseconds */
  275. };
  276. /*
  277. * This is a `pcap_pkthdr' as actually stored in a savefile.
  278. *
  279. * Do not change the format of this structure, in any way (this includes
  280. * changes that only affect the length of fields in this structure),
  281. * and do not make the time stamp anything other than seconds and
  282. * microseconds (e.g., seconds and nanoseconds). Instead:
  283. *
  284. * introduce a new structure for the new format;
  285. *
  286. * send mail to "tcpdump-workers@lists.tcpdump.org", requesting
  287. * a new magic number for your new capture file format, and, when
  288. * you get the new magic number, put it in "savefile.c";
  289. *
  290. * use that magic number for save files with the changed record
  291. * header;
  292. *
  293. * make the code in "savefile.c" capable of reading files with
  294. * the old record header as well as files with the new record header
  295. * (using the magic number to determine the header format).
  296. *
  297. * Then supply the changes by forking the branch at
  298. *
  299. * https://github.com/the-tcpdump-group/libpcap/issues
  300. *
  301. * and issuing a pull request, so that future versions of libpcap and
  302. * programs that use it (such as tcpdump) will be able to read your new
  303. * capture file format.
  304. */
  305. struct pcap_sf_pkthdr {
  306. struct pcap_timeval ts; /* time stamp */
  307. bpf_u_int32 caplen; /* length of portion present */
  308. bpf_u_int32 len; /* length this packet (off wire) */
  309. };
  310. /*
  311. * How a `pcap_pkthdr' is actually stored in savefiles written
  312. * by some patched versions of libpcap (e.g. the ones in Red
  313. * Hat Linux 6.1 and 6.2).
  314. *
  315. * Do not change the format of this structure, in any way (this includes
  316. * changes that only affect the length of fields in this structure).
  317. * Instead, introduce a new structure, as per the above.
  318. */
  319. struct pcap_sf_patched_pkthdr {
  320. struct pcap_timeval ts; /* time stamp */
  321. bpf_u_int32 caplen; /* length of portion present */
  322. bpf_u_int32 len; /* length this packet (off wire) */
  323. int index;
  324. unsigned short protocol;
  325. unsigned char pkt_type;
  326. };
  327. /*
  328. * User data structure for the one-shot callback used for pcap_next()
  329. * and pcap_next_ex().
  330. */
  331. struct oneshot_userdata {
  332. struct pcap_pkthdr *hdr;
  333. const u_char **pkt;
  334. pcap_t *pd;
  335. };
  336. #ifndef min
  337. #define min(a, b) ((a) > (b) ? (b) : (a))
  338. #endif
  339. int pcap_offline_read(pcap_t *, int, pcap_handler, u_char *);
  340. #include <stdarg.h>
  341. #include "portability.h"
  342. /*
  343. * Does the packet count argument to a module's read routine say
  344. * "supply packets until you run out of packets"?
  345. */
  346. #define PACKET_COUNT_IS_UNLIMITED(count) ((count) <= 0)
  347. /*
  348. * Routines that most pcap implementations can use for non-blocking mode.
  349. */
  350. #if !defined(_WIN32) && !defined(MSDOS)
  351. int pcap_getnonblock_fd(pcap_t *);
  352. int pcap_setnonblock_fd(pcap_t *p, int);
  353. #endif
  354. /*
  355. * Internal interfaces for "pcap_create()".
  356. *
  357. * "pcap_create_interface()" is the routine to do a pcap_create on
  358. * a regular network interface. There are multiple implementations
  359. * of this, one for each platform type (Linux, BPF, DLPI, etc.),
  360. * with the one used chosen by the configure script.
  361. *
  362. * "pcap_create_common()" allocates and fills in a pcap_t, for use
  363. * by pcap_create routines.
  364. */
  365. pcap_t *pcap_create_interface(const char *, char *);
  366. pcap_t *pcap_create_common(char *, size_t);
  367. int pcap_do_addexit(pcap_t *);
  368. void pcap_add_to_pcaps_to_close(pcap_t *);
  369. void pcap_remove_from_pcaps_to_close(pcap_t *);
  370. void pcap_cleanup_live_common(pcap_t *);
  371. int pcap_check_activated(pcap_t *);
  372. /*
  373. * Internal interfaces for "pcap_findalldevs()".
  374. *
  375. * A pcap_if_list_t * is a reference to a list of devices.
  376. *
  377. * A get_if_flags_func is a platform-dependent function called to get
  378. * additional interface flags.
  379. *
  380. * "pcap_platform_finddevs()" is the platform-dependent routine to
  381. * find local network interfaces.
  382. *
  383. * "pcap_findalldevs_interfaces()" is a helper to find those interfaces
  384. * using the "standard" mechanisms (SIOCGIFCONF, "getifaddrs()", etc.).
  385. *
  386. * "add_dev()" adds an entry to a pcap_if_list_t.
  387. *
  388. * "find_dev()" tries to find a device, by name, in a pcap_if_list_t.
  389. *
  390. * "find_or_add_dev()" checks whether a device is already in a pcap_if_list_t
  391. * and, if not, adds an entry for it.
  392. */
  393. struct pcap_if_list;
  394. typedef struct pcap_if_list pcap_if_list_t;
  395. typedef int (*get_if_flags_func)(const char *, bpf_u_int32 *, char *);
  396. int pcap_platform_finddevs(pcap_if_list_t *, char *);
  397. #if !defined(_WIN32) && !defined(MSDOS)
  398. int pcap_findalldevs_interfaces(pcap_if_list_t *, char *,
  399. int (*)(const char *), get_if_flags_func);
  400. #endif
  401. pcap_if_t *find_or_add_dev(pcap_if_list_t *, const char *, bpf_u_int32,
  402. get_if_flags_func, const char *, char *);
  403. pcap_if_t *find_dev(pcap_if_list_t *, const char *);
  404. pcap_if_t *add_dev(pcap_if_list_t *, const char *, bpf_u_int32, const char *,
  405. char *);
  406. int add_addr_to_dev(pcap_if_t *, struct sockaddr *, size_t,
  407. struct sockaddr *, size_t, struct sockaddr *, size_t,
  408. struct sockaddr *dstaddr, size_t, char *errbuf);
  409. #ifndef _WIN32
  410. pcap_if_t *find_or_add_if(pcap_if_list_t *, const char *, bpf_u_int32,
  411. get_if_flags_func, char *);
  412. int add_addr_to_if(pcap_if_list_t *, const char *, bpf_u_int32,
  413. get_if_flags_func,
  414. struct sockaddr *, size_t, struct sockaddr *, size_t,
  415. struct sockaddr *, size_t, struct sockaddr *, size_t, char *);
  416. #endif
  417. /*
  418. * Internal interfaces for "pcap_open_offline()".
  419. *
  420. * "pcap_open_offline_common()" allocates and fills in a pcap_t, for use
  421. * by pcap_open_offline routines.
  422. *
  423. * "sf_cleanup()" closes the file handle associated with a pcap_t, if
  424. * appropriate, and frees all data common to all modules for handling
  425. * savefile types.
  426. */
  427. pcap_t *pcap_open_offline_common(char *ebuf, size_t size);
  428. void sf_cleanup(pcap_t *p);
  429. /*
  430. * Internal interfaces for both "pcap_create()" and routines that
  431. * open savefiles.
  432. *
  433. * "pcap_oneshot()" is the standard one-shot callback for "pcap_next()"
  434. * and "pcap_next_ex()".
  435. */
  436. void pcap_oneshot(u_char *, const struct pcap_pkthdr *, const u_char *);
  437. #ifdef _WIN32
  438. void pcap_win32_err_to_str(DWORD, char *);
  439. #endif
  440. int install_bpf_program(pcap_t *, struct bpf_program *);
  441. int pcap_strcasecmp(const char *, const char *);
  442. #ifdef YYDEBUG
  443. extern int pcap_debug;
  444. #endif
  445. #ifdef __cplusplus
  446. }
  447. #endif
  448. #endif