2 * Copyright (c) 1994, 1995, 1996
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 #include <pcap/pcap.h>
45 * Make sure Packet32.h doesn't define BPF structures that we've
46 * probably already defined as a result of including <pcap/pcap.h>.
48 #define BPF_MAJOR_VERSION
55 #if (defined(_MSC_VER) && (_MSC_VER <= 1200)) /* we are compiling with Visual Studio 6, that doesn't support the LL suffix*/
58 * Swap byte ordering of unsigned long long timestamp on a big endian
61 #define SWAPLL(ull) ((ull & 0xff00000000000000) >> 56) | \
62 ((ull & 0x00ff000000000000) >> 40) | \
63 ((ull & 0x0000ff0000000000) >> 24) | \
64 ((ull & 0x000000ff00000000) >> 8) | \
65 ((ull & 0x00000000ff000000) << 8) | \
66 ((ull & 0x0000000000ff0000) << 24) | \
67 ((ull & 0x000000000000ff00) << 40) | \
68 ((ull & 0x00000000000000ff) << 56)
70 #else /* A recent Visual studio compiler or not VC */
73 * Swap byte ordering of unsigned long long timestamp on a big endian
76 #define SWAPLL(ull) ((ull & 0xff00000000000000LL) >> 56) | \
77 ((ull & 0x00ff000000000000LL) >> 40) | \
78 ((ull & 0x0000ff0000000000LL) >> 24) | \
79 ((ull & 0x000000ff00000000LL) >> 8) | \
80 ((ull & 0x00000000ff000000LL) << 8) | \
81 ((ull & 0x0000000000ff0000LL) << 24) | \
82 ((ull & 0x000000000000ff00LL) << 40) | \
83 ((ull & 0x00000000000000ffLL) << 56)
88 * Maximum snapshot length.
90 * Somewhat arbitrary, but chosen to be:
92 * 1) big enough for maximum-size Linux loopback packets (65549)
93 * and some USB packets captured with USBPcap:
95 * http://desowin.org/usbpcap/
97 * (> 131072, < 262144)
101 * 2) small enough not to cause attempts to allocate huge amounts of
102 * memory; some applications might use the snapshot length in a
103 * savefile header to control the size of the buffer they allocate,
104 * so a size of, say, 2^31-1 might not work well.
106 * We don't enforce this in pcap_set_snaplen(), but we use it internally.
108 #define MAXIMUM_SNAPLEN 262144
112 int timeout
; /* timeout for buffering */
115 int rfmon
; /* monitor mode */
116 int immediate
; /* immediate mode - deliver packets as soon as they arrive */
118 int tstamp_precision
;
121 typedef int (*activate_op_t
)(pcap_t
*);
122 typedef int (*can_set_rfmon_op_t
)(pcap_t
*);
123 typedef int (*read_op_t
)(pcap_t
*, int cnt
, pcap_handler
, u_char
*);
124 typedef int (*inject_op_t
)(pcap_t
*, const void *, size_t);
125 typedef int (*setfilter_op_t
)(pcap_t
*, struct bpf_program
*);
126 typedef int (*setdirection_op_t
)(pcap_t
*, pcap_direction_t
);
127 typedef int (*set_datalink_op_t
)(pcap_t
*, int);
128 typedef int (*getnonblock_op_t
)(pcap_t
*, char *);
129 typedef int (*setnonblock_op_t
)(pcap_t
*, int, char *);
130 typedef int (*stats_op_t
)(pcap_t
*, struct pcap_stat
*);
132 typedef struct pcap_stat
*(*stats_ex_op_t
)(pcap_t
*, int *);
133 typedef int (*setbuff_op_t
)(pcap_t
*, int);
134 typedef int (*setmode_op_t
)(pcap_t
*, int);
135 typedef int (*setmintocopy_op_t
)(pcap_t
*, int);
136 typedef HANDLE (*getevent_op_t
)(pcap_t
*);
137 typedef int (*oid_get_request_op_t
)(pcap_t
*, bpf_u_int32
, void *, size_t *);
138 typedef int (*oid_set_request_op_t
)(pcap_t
*, bpf_u_int32
, const void *, size_t *);
139 typedef u_int (*sendqueue_transmit_op_t
)(pcap_t
*, pcap_send_queue
*, int);
140 typedef int (*setuserbuffer_op_t
)(pcap_t
*, int);
141 typedef int (*live_dump_op_t
)(pcap_t
*, char *, int, int);
142 typedef int (*live_dump_ended_op_t
)(pcap_t
*, int);
143 typedef PAirpcapHandle (*get_airpcap_handle_op_t
)(pcap_t
*);
145 typedef void (*cleanup_op_t
)(pcap_t
*);
148 * We put all the stuff used in the read code path at the beginning,
149 * to try to keep it together in the same cache line or lines.
153 * Method to call to read packets on a live capture.
158 * Method to call to read packets from a savefile.
160 int (*next_packet_op
)(pcap_t
*, struct pcap_pkthdr
*, u_char
**);
177 int break_loop
; /* flag set to force break from packet-reading loop */
179 void *priv
; /* private data for methods */
182 FILE *rfile
; /* null if live capture, non-null if savefile */
184 struct pcap
*next
; /* list of open pcaps that need stuff cleared on close */
187 * File version number; meaningful only for a savefile, but we
188 * keep it here so that apps that (mistakenly) ask for the
189 * version numbers will get the same zero values that they
196 int linktype
; /* Network linktype */
197 int linktype_ext
; /* Extended information stored in the linktype field of a file */
198 int tzoff
; /* timezone offset */
199 int offset
; /* offset for proper alignment */
200 int activated
; /* true if the capture is really started */
201 int oldstyle
; /* if we're opening with pcap_open_live() */
206 * Place holder for pcap_next().
211 struct pcap_stat stat
; /* used for pcap_stats_ex() */
214 /* We're accepting only packets in this direction/these directions. */
215 pcap_direction_t direction
;
218 * Flags to affect BPF code generation.
220 int bpf_codegen_flags
;
223 * Placeholder for filter code if bpf not in kernel.
225 struct bpf_program fcode
;
227 char errbuf
[PCAP_ERRBUF_SIZE
+ 1];
230 int tstamp_type_count
;
231 u_int
*tstamp_type_list
;
232 int tstamp_precision_count
;
233 u_int
*tstamp_precision_list
;
235 struct pcap_pkthdr pcap_header
; /* This is needed for the pcap_next_ex() to work */
240 activate_op_t activate_op
;
241 can_set_rfmon_op_t can_set_rfmon_op
;
242 inject_op_t inject_op
;
243 setfilter_op_t setfilter_op
;
244 setdirection_op_t setdirection_op
;
245 set_datalink_op_t set_datalink_op
;
246 getnonblock_op_t getnonblock_op
;
247 setnonblock_op_t setnonblock_op
;
251 * Routine to use as callback for pcap_next()/pcap_next_ex().
253 pcap_handler oneshot_callback
;
257 * These are, at least currently, specific to the Win32 NPF
260 stats_ex_op_t stats_ex_op
;
261 setbuff_op_t setbuff_op
;
262 setmode_op_t setmode_op
;
263 setmintocopy_op_t setmintocopy_op
;
264 getevent_op_t getevent_op
;
265 oid_get_request_op_t oid_get_request_op
;
266 oid_set_request_op_t oid_set_request_op
;
267 sendqueue_transmit_op_t sendqueue_transmit_op
;
268 setuserbuffer_op_t setuserbuffer_op
;
269 live_dump_op_t live_dump_op
;
270 live_dump_ended_op_t live_dump_ended_op
;
271 get_airpcap_handle_op_t get_airpcap_handle_op
;
273 cleanup_op_t cleanup_op
;
277 * BPF code generation flags.
279 #define BPF_SPECIAL_VLAN_HANDLING 0x00000001 /* special VLAN handling for Linux */
282 * This is a timeval as stored in a savefile.
283 * It has to use the same types everywhere, independent of the actual
284 * `struct timeval'; `struct timeval' has 32-bit tv_sec values on some
285 * platforms and 64-bit tv_sec values on other platforms, and writing
286 * out native `struct timeval' values would mean files could only be
287 * read on systems with the same tv_sec size as the system on which
288 * the file was written.
291 struct pcap_timeval
{
292 bpf_int32 tv_sec
; /* seconds */
293 bpf_int32 tv_usec
; /* microseconds */
297 * This is a `pcap_pkthdr' as actually stored in a savefile.
299 * Do not change the format of this structure, in any way (this includes
300 * changes that only affect the length of fields in this structure),
301 * and do not make the time stamp anything other than seconds and
302 * microseconds (e.g., seconds and nanoseconds). Instead:
304 * introduce a new structure for the new format;
306 * send mail to "tcpdump-workers@lists.tcpdump.org", requesting
307 * a new magic number for your new capture file format, and, when
308 * you get the new magic number, put it in "savefile.c";
310 * use that magic number for save files with the changed record
313 * make the code in "savefile.c" capable of reading files with
314 * the old record header as well as files with the new record header
315 * (using the magic number to determine the header format).
317 * Then supply the changes by forking the branch at
319 * https://github.com/the-tcpdump-group/libpcap/issues
321 * and issuing a pull request, so that future versions of libpcap and
322 * programs that use it (such as tcpdump) will be able to read your new
323 * capture file format.
326 struct pcap_sf_pkthdr
{
327 struct pcap_timeval ts
; /* time stamp */
328 bpf_u_int32 caplen
; /* length of portion present */
329 bpf_u_int32 len
; /* length this packet (off wire) */
333 * How a `pcap_pkthdr' is actually stored in savefiles written
334 * by some patched versions of libpcap (e.g. the ones in Red
335 * Hat Linux 6.1 and 6.2).
337 * Do not change the format of this structure, in any way (this includes
338 * changes that only affect the length of fields in this structure).
339 * Instead, introduce a new structure, as per the above.
342 struct pcap_sf_patched_pkthdr
{
343 struct pcap_timeval ts
; /* time stamp */
344 bpf_u_int32 caplen
; /* length of portion present */
345 bpf_u_int32 len
; /* length this packet (off wire) */
347 unsigned short protocol
;
348 unsigned char pkt_type
;
352 * User data structure for the one-shot callback used for pcap_next()
353 * and pcap_next_ex().
355 struct oneshot_userdata
{
356 struct pcap_pkthdr
*hdr
;
362 #define min(a, b) ((a) > (b) ? (b) : (a))
365 int pcap_offline_read(pcap_t
*, int, pcap_handler
, u_char
*);
369 #include "portability.h"
372 * Does the packet count argument to a module's read routine say
373 * "supply packets until you run out of packets"?
375 #define PACKET_COUNT_IS_UNLIMITED(count) ((count) <= 0)
378 * Routines that most pcap implementations can use for non-blocking mode.
380 #if !defined(_WIN32) && !defined(MSDOS)
381 int pcap_getnonblock_fd(pcap_t
*, char *);
382 int pcap_setnonblock_fd(pcap_t
*p
, int, char *);
386 * Internal interfaces for "pcap_create()".
388 * "pcap_create_interface()" is the routine to do a pcap_create on
389 * a regular network interface. There are multiple implementations
390 * of this, one for each platform type (Linux, BPF, DLPI, etc.),
391 * with the one used chosen by the configure script.
393 * "pcap_create_common()" allocates and fills in a pcap_t, for use
394 * by pcap_create routines.
396 pcap_t
*pcap_create_interface(const char *, char *);
397 pcap_t
*pcap_create_common(char *, size_t);
398 int pcap_do_addexit(pcap_t
*);
399 void pcap_add_to_pcaps_to_close(pcap_t
*);
400 void pcap_remove_from_pcaps_to_close(pcap_t
*);
401 void pcap_cleanup_live_common(pcap_t
*);
402 int pcap_check_activated(pcap_t
*);
405 * Internal interfaces for "pcap_findalldevs()".
407 * "pcap_platform_finddevs()" is a platform-dependent routine to
408 * find local network interfaces.
410 * "pcap_findalldevs_interfaces()" is a helper to find those interfaces
411 * using the "standard" mechanisms (SIOCGIFCONF, "getifaddrs()", etc.).
413 * "pcap_add_if()" adds an interface to the list of interfaces, for
414 * use by various "find interfaces" routines.
416 int pcap_platform_finddevs(pcap_if_t
**, char *);
417 #if !defined(_WIN32) && !defined(MSDOS)
418 int pcap_findalldevs_interfaces(pcap_if_t
**, char *,
419 int (*)(const char *));
421 int add_addr_to_iflist(pcap_if_t
**, const char *, bpf_u_int32
,
422 struct sockaddr
*, size_t, struct sockaddr
*, size_t,
423 struct sockaddr
*, size_t, struct sockaddr
*, size_t, char *);
424 int add_addr_to_dev(pcap_if_t
*, struct sockaddr
*, size_t,
425 struct sockaddr
*, size_t, struct sockaddr
*, size_t,
426 struct sockaddr
*dstaddr
, size_t, char *errbuf
);
427 int pcap_add_if(pcap_if_t
**, const char *, bpf_u_int32
, const char *,
429 int add_or_find_if(pcap_if_t
**, pcap_if_t
**, const char *, bpf_u_int32
,
430 const char *, char *);
432 bpf_u_int32
if_flags_to_pcap_flags(const char *, u_int
);
436 * Internal interfaces for "pcap_open_offline()".
438 * "pcap_open_offline_common()" allocates and fills in a pcap_t, for use
439 * by pcap_open_offline routines.
441 * "sf_cleanup()" closes the file handle associated with a pcap_t, if
442 * appropriate, and frees all data common to all modules for handling
445 pcap_t
*pcap_open_offline_common(char *ebuf
, size_t size
);
446 void sf_cleanup(pcap_t
*p
);
449 * Internal interfaces for both "pcap_create()" and routines that
452 * "pcap_oneshot()" is the standard one-shot callback for "pcap_next()"
453 * and "pcap_next_ex()".
455 void pcap_oneshot(u_char
*, const struct pcap_pkthdr
*, const u_char
*);
458 void pcap_win32_err_to_str(DWORD
, char *);
461 int install_bpf_program(pcap_t
*, struct bpf_program
*);
463 int pcap_strcasecmp(const char *, const char *);