1PCAP(3PCAP) PCAP(3PCAP)
2
6 pcap - Packet Capture library
7
9 #include <pcap/pcap.h>
10
12 The Packet Capture library provides a high level interface to packet
13 capture systems. All packets on the network, even those destined for
14 other hosts, are accessible through this mechanism. It also supports
15 saving captured packets to a ``savefile'', and reading packets from a
16 ``savefile''.
17 Opening a capture handle for reading
19 To open a handle for a live capture, given the name of the network or
20 other interface on which the capture should be done, call pcap_cre‐
21 ate(), set the appropriate options on the handle, and then activate it
22 with pcap_activate().
23 To obtain a list of devices that can be opened for a live capture, call
25 pcap_findalldevs(); to free the list returned by pcap_findalldevs(),
26 call pcap_freealldevs(). pcap_lookupdev() will return the first device
27 on that list that is not a ``loopback`` network interface.
28 To open a handle for a ``savefile'' from which to read packets, given
30 the pathname of the ``savefile'', call pcap_open_offline(); to set up a
31 handle for a ``savefile'', given a FILE * referring to a file already
32 opened for reading, call pcap_fopen_offline().
33 In order to get a ``fake'' pcap_t for use in routines that require a
35 pcap_t as an argument, such as routines to open a ``savefile'' for
36 writing and to compile a filter expression, call pcap_open_dead().
37 pcap_create(), pcap_open_offline(), pcap_fopen_offline(), and
39 pcap_open_dead() return a pointer to a pcap_t, which is the handle used
40 for reading packets from the capture stream or the ``savefile'', and
41 for finding out information about the capture stream or ``savefile''.
42 To close a handle, use pcap_close().
43 The options that can be set on a capture handle include
45 snapshot length
47 If, when capturing, you capture the entire contents of the
48 packet, that requires more CPU time to copy the packet to your
49 application, more disk and possibly network bandwidth to write
50 the packet data to a file, and more disk space to save the
51 packet. If you don't need the entire contents of the packet -
52 for example, if you are only interested in the TCP headers of
53 packets - you can set the "snapshot length" for the capture to
54 an appropriate value. If the snapshot length is set to snaplen,
55 and snaplen is less than the size of a packet that is captured,
56 only the first snaplen bytes of that packet will be captured and
57 provided as packet data.
58 A snapshot length of 65535 should be sufficient, on most if not
60 all networks, to capture all the data available from the packet.
61 The snapshot length is set with pcap_set_snaplen().
63 promiscuous mode
65 On broadcast LANs such as Ethernet, if the network isn't
66 switched, or if the adapter is connected to a "mirror port" on a
67 switch to which all packets passing through the switch are sent,
68 a network adapter receives all packets on the LAN, including
69 unicast or multicast packets not sent to a network address that
70 the network adapter isn't configured to recognize.
71 Normally, the adapter will discard those packets; however, many
73 network adapters support "promiscuous mode", which is a mode in
74 which all packets, even if they are not sent to an address that
75 the adapter recognizes, are provided to the host. This is use‐
76 ful for passively capturing traffic between two or more other
77 hosts for analysis.
78 Note that even if an application does not set promiscuous mode,
80 the adapter could well be in promiscuous mode for some other
81 reason.
82 For now, this doesn't work on the "any" device; if an argument
84 of "any" or NULL is supplied, the setting of promiscuous mode is
85 ignored.
86 Promiscuous mode is set with pcap_set_promisc().
88 monitor mode
90 On IEEE 802.11 wireless LANs, even if an adapter is in promiscu‐
91 ous mode, it will supply to the host only frames for the network
92 with which it's associated. It might also supply only data
93 frames, not management or control frames, and might not provide
94 the 802.11 header or radio information pseudo-header for those
95 frames.
96 In "monitor mode", sometimes also called "rfmon mode" (for
98 "Radio Frequency MONitor"), the adapter will supply all frames
99 that it receives, with 802.11 headers, and might supply a
100 pseudo-header with radio information about the frame as well.
101 Note that in monitor mode the adapter might disassociate from
103 the network with which it's associated, so that you will not be
104 able to use any wireless networks with that adapter. This could
105 prevent accessing files on a network server, or resolving host
106 names or network addresses, if you are capturing in monitor mode
107 and are not connected to another network with another adapter.
108 Monitor mode is set with pcap_set_rfmon(), and
110 pcap_can_set_rfmon() can be used to determine whether an adapter
111 can be put into monitor mode.
112 packet buffer timeout
114 If, when capturing, packets are delivered as soon as they
115 arrive, the application capturing the packets will be woken up
116 for each packet as it arrives, and might have to make one or
117 more calls to the operating system to fetch each packet.
118 If, instead, packets are not delivered as soon as they arrive,
120 but are delivered after a short delay (called a "packet buffer
121 timeout"), more than one packet can be accumulated before the
122 packets are delivered, so that a single wakeup would be done for
123 multiple packets, and each set of calls made to the operating
124 system would supply multiple packets, rather than a single
125 packet. This reduces the per-packet CPU overhead if packets are
126 arriving at a high rate, increasing the number of packets per
127 second that can be captured.
128 The packet buffer timeout is required so that an application
130 won't wait for the operating system's capture buffer to fill up
131 before packets are delivered; if packets are arriving slowly,
132 that wait could take an arbitrarily long period of time.
133 Not all platforms support a packet buffer timeout; on platforms
135 that don't, the packet buffer timeout is ignored. A zero value
136 for the timeout, on platforms that support a packet buffer time‐
137 out, will cause a read to wait forever to allow enough packets
138 to arrive, with no timeout. A negative value is invalid; the
139 result of setting the timeout to a negative value is unpre‐
140 dictable.
141 NOTE: the packet buffer timeout cannot be used to cause calls
143 that read packets to return within a limited period of time,
144 because, on some platforms, the packet buffer timeout isn't sup‐
145 ported, and, on other platforms, the timer doesn't start until
146 at least one packet arrives. This means that the packet buffer
147 timeout should NOT be used, for example, in an interactive
148 application to allow the packet capture loop to ``poll'' for
149 user input periodically, as there's no guarantee that a call
150 reading packets will return after the timeout expires even if no
151 packets have arrived.
152 The packet buffer timeout is set with pcap_set_timeout().
154 buffer size
156 Packets that arrive for a capture are stored in a buffer, so
157 that they do not have to be read by the application as soon as
158 they arrive. On some platforms, the buffer's size can be set; a
159 size that's too small could mean that, if too many packets are
160 being captured and the snapshot length doesn't limit the amount
161 of data that's buffered, packets could be dropped if the buffer
162 fills up before the application can read packets from it, while
163 a size that's too large could use more non-pageable operating
164 system memory than is necessary to prevent packets from being
165 dropped.
166 The buffer size is set with pcap_set_buffer_size().
168 timestamp type
170 On some platforms, the time stamp given to packets on live cap‐
171 tures can come from different sources that can have different
172 resolutions or that can have different relationships to the time
173 values for the current time supplied by routines on the native
174 operating system. See pcap-tstamp(7) for a list of time stamp
175 types.
176 The time stamp type is set with pcap_set_tstamp_type().
178 Reading packets from a network interface may require that you have spe‐
180 cial privileges:
181 Under SunOS 3.x or 4.x with NIT or BPF:
183 You must have read access to /dev/nit or /dev/bpf*.
184 Under Solaris with DLPI:
186 You must have read/write access to the network pseudo device,
187 e.g. /dev/le. On at least some versions of Solaris, however,
188 this is not sufficient to allow tcpdump to capture in promiscu‐
189 ous mode; on those versions of Solaris, you must be root, or the
190 application capturing packets must be installed setuid to root,
191 in order to capture in promiscuous mode. Note that, on many
192 (perhaps all) interfaces, if you don't capture in promiscuous
193 mode, you will not see any outgoing packets, so a capture not
194 done in promiscuous mode may not be very useful.
195 In newer versions of Solaris, you must have been given the
197 net_rawaccess privilege; this is both necessary and sufficient
198 to give you access to the network pseudo-device - there is no
199 need to change the privileges on that device. A user can be
200 given that privilege by, for example, adding that privilege to
201 the user's defaultpriv key with the usermod (8) command.
202 Under HP-UX with DLPI:
204 You must be root or the application capturing packets must be
205 installed setuid to root.
206 Under IRIX with snoop:
208 You must be root or the application capturing packets must be
209 installed setuid to root.
210 Under Linux:
212 You must be root or the application capturing packets must be
213 installed setuid to root (unless your distribution has a kernel
214 that supports capability bits such as CAP_NET_RAW and code to
215 allow those capability bits to be given to particular accounts
216 and to cause those bits to be set on a user's initial processes
217 when they log in, in which case you must have CAP_NET_RAW in
218 order to capture and CAP_NET_ADMIN to enumerate network devices
219 with, for example, the -D flag).
220 Under ULTRIX and Digital UNIX/Tru64 UNIX:
222 Any user may capture network traffic. However, no user (not
223 even the super-user) can capture in promiscuous mode on an
224 interface unless the super-user has enabled promiscuous-mode
225 operation on that interface using pfconfig(8), and no user (not
226 even the super-user) can capture unicast traffic received by or
227 sent by the machine on an interface unless the super-user has
228 enabled copy-all-mode operation on that interface using pfcon‐
229 fig, so useful packet capture on an interface probably requires
230 that either promiscuous-mode or copy-all-mode operation, or both
231 modes of operation, be enabled on that interface.
232 Under BSD (this includes macOS):
234 You must have read access to /dev/bpf* on systems that don't
235 have a cloning BPF device, or to /dev/bpf on systems that do.
236 On BSDs with a devfs (this includes macOS), this might involve
237 more than just having somebody with super-user access setting
238 the ownership or permissions on the BPF devices - it might
239 involve configuring devfs to set the ownership or permissions
240 every time the system is booted, if the system even supports
241 that; if it doesn't support that, you might have to find some
242 other way to make that happen at boot time.
243 Reading a saved packet file doesn't require special privileges.
245 The packets read from the handle may include a ``pseudo-header'' con‐
247 taining various forms of packet meta-data, and probably includes a
248 link-layer header whose contents can differ for different network
249 interfaces. To determine the format of the packets supplied by the
250 handle, call pcap_datalink(); https://www.tcpdump.org/linktypes.html
251 lists the values it returns and describes the packet formats that cor‐
252 respond to those values.
253 Do NOT assume that the packets for a given capture or ``savefile`` will
255 have any given link-layer header type, such as DLT_EN10MB for Ethernet.
256 For example, the "any" device on Linux will have a link-layer header
257 type of DLT_LINUX_SLL even if all devices on the system at the time the
258 "any" device is opened have some other data link type, such as
259 DLT_EN10MB for Ethernet.
260 To obtain the FILE * corresponding to a pcap_t opened for a ``save‐
262 file'', call pcap_file().
263 Routines
265 pcap_create(3PCAP)
267 get a pcap_t for live capture
268 pcap_activate(3PCAP)
270 activate a pcap_t for live capture
271 pcap_findalldevs(3PCAP)
273 get a list of devices that can be opened for a live cap‐
274 ture
275 pcap_freealldevs(3PCAP)
277 free list of devices
278 pcap_lookupdev(3PCAP)
280 get first non-loopback device on that list
281 pcap_open_offline(3PCAP)
283 open a pcap_t for a ``savefile'', given a pathname
284 pcap_open_offline_with_tstamp_precision(3PCAP)
286 open a pcap_t for a ``savefile'', given a pathname, and
287 specify the precision to provide for packet time stamps
288 pcap_fopen_offline(3PCAP)
290 open a pcap_t for a ``savefile'', given a FILE *
291 pcap_fopen_offline_with_tstamp_precision(3PCAP)
293 open a pcap_t for a ``savefile'', given a FILE *, and
294 specify the precision to provide for packet time stamps
295 pcap_open_dead(3PCAP)
297 create a ``fake'' pcap_t
298 pcap_close(3PCAP)
300 close a pcap_t
301 pcap_set_snaplen(3PCAP)
303 set the snapshot length for a not-yet-activated pcap_t
304 for live capture
305 pcap_snapshot(3PCAP)
307 get the snapshot length for a pcap_t
308 pcap_set_promisc(3PCAP)
310 set promiscuous mode for a not-yet-activated pcap_t for
311 live capture
312 pcap_set_protocol_linux(3PCAP)
314 set capture protocol for a not-yet-activated pcap_t for
315 live capture (Linux only)
316 pcap_set_rfmon(3PCAP)
318 set monitor mode for a not-yet-activated pcap_t for live
319 capture
320 pcap_can_set_rfmon(3PCAP)
322 determine whether monitor mode can be set for a pcap_t
323 for live capture
324 pcap_set_timeout(3PCAP)
326 set packet buffer timeout for a not-yet-activated pcap_t
327 for live capture
328 pcap_set_buffer_size(3PCAP)
330 set buffer size for a not-yet-activated pcap_t for live
331 capture
332 pcap_set_tstamp_type(3PCAP)
334 set time stamp type for a not-yet-activated pcap_t for
335 live capture
336 pcap_list_tstamp_types(3PCAP)
338 get list of available time stamp types for a not-yet-
339 activated pcap_t for live capture
340 pcap_free_tstamp_types(3PCAP)
342 free list of available time stamp types
343 pcap_tstamp_type_val_to_name(3PCAP)
345 get name for a time stamp type
346 pcap_tstamp_type_val_to_description(3PCAP)
348 get description for a time stamp type
349 pcap_tstamp_type_name_to_val(3PCAP)
351 get time stamp type corresponding to a name
352 pcap_set_tstamp_precision(3PCAP)
354 set time stamp precision for a not-yet-activated pcap_t
355 for live capture
356 pcap_get_tstamp_precision(3PCAP)
358 get the time stamp precision of a pcap_t for live capture
359 pcap_datalink(3PCAP)
361 get link-layer header type for a pcap_t
362 pcap_file(3PCAP)
364 get the FILE * for a pcap_t opened for a ``savefile''
365 pcap_is_swapped(3PCAP)
367 determine whether a ``savefile'' being read came from a
368 machine with the opposite byte order
369 pcap_major_version(3PCAP)
371 pcap_minor_version(3PCAP)
372 get the major and minor version of the file format ver‐
373 sion for a ``savefile''
374 Selecting a link-layer header type for a live capture
376 Some devices may provide more than one link-layer header type. To
377 obtain a list of all link-layer header types provided by a device, call
378 pcap_list_datalinks() on an activated pcap_t for the device. To free a
379 list of link-layer header types, call pcap_free_datalinks(). To set
380 the link-layer header type for a device, call pcap_set_datalink().
381 This should be done after the device has been activated but before any
382 packets are read and before any filters are compiled or installed.
383 Routines
385 pcap_list_datalinks(3PCAP)
387 get a list of link-layer header types for a device
388 pcap_free_datalinks(3PCAP)
390 free list of link-layer header types
391 pcap_set_datalink(3PCAP)
393 set link-layer header type for a device
394 pcap_datalink_val_to_name(3PCAP)
396 get name for a link-layer header type
397 pcap_datalink_val_to_description(3PCAP)
399 get description for a link-layer header type
400 pcap_datalink_name_to_val(3PCAP)
402 get link-layer header type corresponding to a name
403 Reading packets
405 Packets are read with pcap_dispatch() or pcap_loop(), which process one
406 or more packets, calling a callback routine for each packet, or with
407 pcap_next() or pcap_next_ex(), which return the next packet. The call‐
408 back for pcap_dispatch() and pcap_loop() is supplied a pointer to a
409 struct pcap_pkthdr, which includes the following members:
410 ts a struct timeval containing the time when the packet was
412 captured
413 caplen a bpf_u_int32 giving the number of bytes of the packet
415 that are available from the capture
416 len a bpf_u_int32 giving the length of the packet, in bytes
418 (which might be more than the number of bytes available
419 from the capture, if the length of the packet is larger
420 than the maximum number of bytes to capture).
421 The callback is also supplied a const u_char pointer to the first
423 caplen (as given in the struct pcap_pkthdr mentioned above) bytes of
424 data from the packet. This won't necessarily be the entire packet; to
425 capture the entire packet, you will have to provide a value for snaplen
426 in your call to pcap_set_snaplen() that is sufficiently large to get
427 all of the packet's data - a value of 65535 should be sufficient on
428 most if not all networks). When reading from a ``savefile'', the snap‐
429 shot length specified when the capture was performed will limit the
430 amount of packet data available.
431 pcap_next() is passed an argument that points to a struct pcap_pkthdr
433 structure, and fills it in with the time stamp and length values for
434 the packet. It returns a const u_char to the first caplen bytes of the
435 packet on success, and NULL on error.
436 pcap_next_ex() is passed two pointer arguments, one of which points to
438 a structpcap_pkthdr* and one of which points to a const u_char*. It
439 sets the first pointer to point to a struct pcap_pkthdr structure with
440 the time stamp and length values for the packet, and sets the second
441 pointer to point to the first caplen bytes of the packet.
442 To force the loop in pcap_dispatch() or pcap_loop() to terminate, call
444 pcap_breakloop().
445 By default, when reading packets from an interface opened for a live
447 capture, pcap_dispatch(), pcap_next(), and pcap_next_ex() will, if no
448 packets are currently available to be read, block waiting for packets
449 to become available. On some, but not all, platforms, if a packet buf‐
450 fer timeout was specified, the wait will terminate after the packet
451 buffer timeout expires; applications should be prepared for this, as it
452 happens on some platforms, but should not rely on it, as it does not
453 happen on other platforms. Note that the wait might, or might not,
454 terminate even if no packets are available; applications should be pre‐
455 pared for this to happen, but must not rely on it happening.
456 A handle can be put into ``non-blocking mode'', so that those routines
458 will, rather than blocking, return an indication that no packets are
459 available to read. Call pcap_setnonblock() to put a handle into non-
460 blocking mode or to take it out of non-blocking mode; call pcap_getnon‐
461 block() to determine whether a handle is in non-blocking mode. Note
462 that non-blocking mode does not work correctly in Mac OS X 10.6.
463 Non-blocking mode is often combined with routines such as select(2) or
465 poll(2) or other routines a platform offers to wait for any of a set of
466 descriptors to be ready to read. To obtain, for a handle, a descriptor
467 that can be used in those routines, call pcap_get_selectable_fd(). Not
468 all handles have such a descriptor available; pcap_get_selectable_fd()
469 will return -1 if no such descriptor exists. In addition, for various
470 reasons, one or more of those routines will not work properly with the
471 descriptor; the documentation for pcap_get_selectable_fd() gives
472 details. Note that, just as an attempt to read packets from a pcap_t
473 may not return any packets if the packet buffer timeout expires, a
474 select(), poll(), or other such call may, if the packet buffer timeout
475 expires, indicate that a descriptor is ready to read even if there are
476 no packets available to read.
477 Routines
479 pcap_dispatch(3PCAP)
481 read a bufferful of packets from a pcap_t open for a live
482 capture or the full set of packets from a pcap_t open for
483 a ``savefile''
484 pcap_loop(3PCAP)
486 read packets from a pcap_t until an interrupt or error
487 occurs
488 pcap_next(3PCAP)
490 read the next packet from a pcap_t without an indication
491 whether an error occurred
492 pcap_next_ex(3PCAP)
494 read the next packet from a pcap_t with an error indica‐
495 tion on an error
496 pcap_breakloop(3PCAP)
498 prematurely terminate the loop in pcap_dispatch() or
499 pcap_loop()
500 pcap_setnonblock(3PCAP)
502 set or clear non-blocking mode on a pcap_t
503 pcap_getnonblock(3PCAP)
505 get the state of non-blocking mode for a pcap_t
506 pcap_get_selectable_fd(3PCAP)
508 attempt to get a descriptor for a pcap_t that can be used
509 in calls such as select(2) and poll(2)
510 Filters
512 In order to cause only certain packets to be returned when reading
513 packets, a filter can be set on a handle. For a live capture, the fil‐
514 tering will be performed in kernel mode, if possible, to avoid copying
515 ``uninteresting'' packets from the kernel to user mode.
516 A filter can be specified as a text string; the syntax and semantics of
518 the string are as described by pcap-filter(7). A filter string is com‐
519 piled into a program in a pseudo-machine-language by pcap_compile() and
520 the resulting program can be made a filter for a handle with pcap_set‐
521 filter(). The result of pcap_compile() can be freed with a call to
522 pcap_freecode(). pcap_compile() may require a network mask for certain
523 expressions in the filter string; pcap_lookupnet() can be used to find
524 the network address and network mask for a given capture device.
525 A compiled filter can also be applied directly to a packet that has
527 been read using pcap_offline_filter().
528 Routines
530 pcap_compile(3PCAP)
532 compile filter expression to a pseudo-machine-language
533 code program
534 pcap_freecode(3PCAP)
536 free a filter program
537 pcap_setfilter(3PCAP)
539 set filter for a pcap_t
540 pcap_lookupnet(3PCAP)
542 get network address and network mask for a capture device
543 pcap_offline_filter(3PCAP)
545 apply a filter program to a packet
546 Incoming and outgoing packets
548 By default, libpcap will attempt to capture both packets sent by the
549 machine and packets received by the machine. To limit it to capturing
550 only packets received by the machine or, if possible, only packets sent
551 by the machine, call pcap_setdirection().
552 Routines
554 pcap_setdirection(3PCAP)
556 specify whether to capture incoming packets, outgoing
557 packets, or both
558 Capture statistics
560 To get statistics about packets received and dropped in a live capture,
561 call pcap_stats().
562 Routines
564 pcap_stats(3PCAP)
566 get capture statistics
567 Opening a handle for writing captured packets
569 To open a ``savefile`` to which to write packets, given the pathname
570 the ``savefile'' should have, call pcap_dump_open(). To open a ``save‐
571 file`` to which to write packets, given the pathname the ``savefile''
572 should have, call pcap_dump_open(); to set up a handle for a ``save‐
573 file'', given a FILE * referring to a file already opened for writing,
574 call pcap_dump_fopen(). They each return pointers to a pcap_dumper_t,
575 which is the handle used for writing packets to the ``savefile''. If
576 it succeeds, it will have created the file if it doesn't exist and
577 truncated the file if it does exist. To close a pcap_dumper_t, call
578 pcap_dump_close().
579 Routines
581 pcap_dump_open(3PCAP)
583 open a pcap_dumper_t for a ``savefile``, given a pathname
584 pcap_dump_fopen(3PCAP)
586 open a pcap_dumper_t for a ``savefile``, given a FILE *
587 pcap_dump_close(3PCAP)
589 close a pcap_dumper_t
590 pcap_dump_file(3PCAP)
592 get the FILE * for a pcap_dumper_t opened for a ``save‐
593 file''
594 Writing packets
596 To write a packet to a pcap_dumper_t, call pcap_dump(). Packets writ‐
597 ten with pcap_dump() may be buffered, rather than being immediately
598 written to the ``savefile''. Closing the pcap_dumper_t will cause all
599 buffered-but-not-yet-written packets to be written to the ``savefile''.
600 To force all packets written to the pcap_dumper_t, and not yet written
601 to the ``savefile'' because they're buffered by the pcap_dumper_t, to
602 be written to the ``savefile'', without closing the pcap_dumper_t, call
603 pcap_dump_flush().
604 Routines
606 pcap_dump(3PCAP)
608 write packet to a pcap_dumper_t
609 pcap_dump_flush(3PCAP)
611 flush buffered packets written to a pcap_dumper_t to the
612 ``savefile''
613 pcap_dump_ftell(3PCAP)
615 get current file position for a pcap_dumper_t
616 Injecting packets
618 If you have the required privileges, you can inject packets onto a net‐
619 work with a pcap_t for a live capture, using pcap_inject() or
620 pcap_sendpacket(). (The two routines exist for compatibility with both
621 OpenBSD and WinPcap; they perform the same function, but have different
622 return values.)
623 Routines
625 pcap_inject(3PCAP)
627 pcap_sendpacket(3PCAP)
628 transmit a packet
629 Reporting errors
631 Some routines return error or warning status codes; to convert them to
632 a string, use pcap_statustostr().
633 Routines
635 pcap_statustostr(3PCAP)
637 get a string for an error or warning status code
638 Getting library version information
640 To get a string giving version information about libpcap, call
641 pcap_lib_version().
642 Routines
644 pcap_lib_version(3PCAP)
646 get library version string
647
649 In versions of libpcap prior to 1.0, the pcap.h header file was not in
650 a pcap directory on most platforms; if you are writing an application
651 that must work on versions of libpcap prior to 1.0, include <pcap.h>,
652 which will include <pcap/pcap.h> for you, rather than including
653 <pcap/pcap.h>.
654 pcap_create() and pcap_activate() were not available in versions of
656 libpcap prior to 1.0; if you are writing an application that must work
657 on versions of libpcap prior to 1.0, either use pcap_open_live() to get
658 a handle for a live capture or, if you want to be able to use the addi‐
659 tional capabilities offered by using pcap_create() and pcap_activate(),
660 use an autoconf(1) script or some other configuration script to check
661 whether the libpcap 1.0 APIs are available and use them only if they
662 are.
663
665 autoconf(1), tcpdump(8), tcpslice(8), pcap-filter(7), pfconfig(8),
666 usermod(8)
667
669 The original authors of libpcap are:
670 Van Jacobson, Craig Leres and Steven McCanne, all of the Lawrence
672 Berkeley National Laboratory, University of California, Berkeley, CA.
673 The current version is available from "The Tcpdump Group"'s Web site at
675 https://www.tcpdump.org/
677
679 To report a security issue please send an e-mail to security@tcp‐
680 dump.org.
681 To report bugs and other problems, contribute patches, request a fea‐
683 ture, provide generic feedback etc please see the file CONTRIBUTING in
684 the libpcap source tree root.
685 20 April 2018 PCAP(3PCAP)