Local changes: - In contrib/libpcap/pcap/bpf.h, do not include pcap/dlt.h. Our system net/dlt.h is pulled in from net/bpf.h. - sys/net/dlt.h: Incorporate changes from libpcap 1.10.3. - lib/libpcap/Makefile: Update for libpcap 1.10.3. Changelog: https://git.tcpdump.org/libpcap/blob/95691ebe7564afa3faa5c6ba0dbd17e351be455a:/CHANGES Reviewed by: emaste Obtained from: https://www.tcpdump.org/release/libpcap-1.10.3.tar.gz Sponsored by: The FreeBSD Foundation
682 lines
18 KiB
C
682 lines
18 KiB
C
/*
|
|
* Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that: (1) source code distributions
|
|
* retain the above copyright notice and this paragraph in its entirety, (2)
|
|
* distributions including binary code include the above copyright notice and
|
|
* this paragraph in its entirety in the documentation or other materials
|
|
* provided with the distribution, and (3) all advertising materials mentioning
|
|
* features or use of this software display the following acknowledgement:
|
|
* ``This product includes software developed by the University of California,
|
|
* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
|
|
* the University nor the names of its contributors may be used to endorse
|
|
* or promote products derived from this software without specific prior
|
|
* written permission.
|
|
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
|
|
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
|
|
*
|
|
* packet filter subroutines for tcpdump
|
|
* Extraction/creation by Jeffrey Mogul, DECWRL
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
#include <config.h>
|
|
#endif
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/time.h>
|
|
#include <sys/timeb.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/file.h>
|
|
#include <sys/ioctl.h>
|
|
#include <net/pfilt.h>
|
|
|
|
struct mbuf;
|
|
struct rtentry;
|
|
#include <net/if.h>
|
|
|
|
#include <netinet/in.h>
|
|
#include <netinet/in_systm.h>
|
|
#include <netinet/ip.h>
|
|
#include <netinet/if_ether.h>
|
|
#include <netinet/ip_var.h>
|
|
#include <netinet/udp.h>
|
|
#include <netinet/udp_var.h>
|
|
#include <netinet/tcp.h>
|
|
#include <netinet/tcpip.h>
|
|
|
|
#include <errno.h>
|
|
#include <netdb.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
/*
|
|
* Make "pcap.h" not include "pcap/bpf.h"; we are going to include the
|
|
* native OS version, as we need various BPF ioctls from it.
|
|
*/
|
|
#define PCAP_DONT_INCLUDE_PCAP_BPF_H
|
|
#include <net/bpf.h>
|
|
|
|
#include "pcap-int.h"
|
|
|
|
#ifdef HAVE_OS_PROTO_H
|
|
#include "os-proto.h"
|
|
#endif
|
|
|
|
/*
|
|
* FDDI packets are padded to make everything line up on a nice boundary.
|
|
*/
|
|
#define PCAP_FDDIPAD 3
|
|
|
|
/*
|
|
* Private data for capturing on Ultrix and DEC OSF/1^WDigital UNIX^W^W
|
|
* Tru64 UNIX packetfilter devices.
|
|
*/
|
|
struct pcap_pf {
|
|
int filtering_in_kernel; /* using kernel filter */
|
|
u_long TotPkts; /* can't oflow for 79 hrs on ether */
|
|
u_long TotAccepted; /* count accepted by filter */
|
|
u_long TotDrops; /* count of dropped packets */
|
|
long TotMissed; /* missed by i/f during this run */
|
|
long OrigMissed; /* missed by i/f before this run */
|
|
};
|
|
|
|
static int pcap_setfilter_pf(pcap_t *, struct bpf_program *);
|
|
|
|
/*
|
|
* BUFSPACE is the size in bytes of the packet read buffer. Most tcpdump
|
|
* applications aren't going to need more than 200 bytes of packet header
|
|
* and the read shouldn't return more packets than packetfilter's internal
|
|
* queue limit (bounded at 256).
|
|
*/
|
|
#define BUFSPACE (200 * 256)
|
|
|
|
static int
|
|
pcap_read_pf(pcap_t *pc, int cnt, pcap_handler callback, u_char *user)
|
|
{
|
|
struct pcap_pf *pf = pc->priv;
|
|
register u_char *p, *bp;
|
|
register int cc, n, buflen, inc;
|
|
register struct enstamp *sp;
|
|
struct enstamp stamp;
|
|
register u_int pad;
|
|
|
|
again:
|
|
cc = pc->cc;
|
|
if (cc == 0) {
|
|
cc = read(pc->fd, (char *)pc->buffer + pc->offset, pc->bufsize);
|
|
if (cc < 0) {
|
|
if (errno == EWOULDBLOCK)
|
|
return (0);
|
|
if (errno == EINVAL &&
|
|
lseek(pc->fd, 0L, SEEK_CUR) + pc->bufsize < 0) {
|
|
/*
|
|
* Due to a kernel bug, after 2^31 bytes,
|
|
* the kernel file offset overflows and
|
|
* read fails with EINVAL. The lseek()
|
|
* to 0 will fix things.
|
|
*/
|
|
(void)lseek(pc->fd, 0L, SEEK_SET);
|
|
goto again;
|
|
}
|
|
pcap_fmt_errmsg_for_errno(pc->errbuf,
|
|
sizeof(pc->errbuf), errno, "pf read");
|
|
return (-1);
|
|
}
|
|
bp = (u_char *)pc->buffer + pc->offset;
|
|
} else
|
|
bp = pc->bp;
|
|
/*
|
|
* Loop through each packet.
|
|
*
|
|
* This assumes that a single buffer of packets will have
|
|
* <= INT_MAX packets, so the packet count doesn't overflow.
|
|
*/
|
|
n = 0;
|
|
pad = pc->fddipad;
|
|
while (cc > 0) {
|
|
/*
|
|
* Has "pcap_breakloop()" been called?
|
|
* If so, return immediately - if we haven't read any
|
|
* packets, clear the flag and return -2 to indicate
|
|
* that we were told to break out of the loop, otherwise
|
|
* leave the flag set, so that the *next* call will break
|
|
* out of the loop without having read any packets, and
|
|
* return the number of packets we've processed so far.
|
|
*/
|
|
if (pc->break_loop) {
|
|
if (n == 0) {
|
|
pc->break_loop = 0;
|
|
return (-2);
|
|
} else {
|
|
pc->cc = cc;
|
|
pc->bp = bp;
|
|
return (n);
|
|
}
|
|
}
|
|
if (cc < sizeof(*sp)) {
|
|
snprintf(pc->errbuf, sizeof(pc->errbuf),
|
|
"pf short read (%d)", cc);
|
|
return (-1);
|
|
}
|
|
if ((long)bp & 3) {
|
|
sp = &stamp;
|
|
memcpy((char *)sp, (char *)bp, sizeof(*sp));
|
|
} else
|
|
sp = (struct enstamp *)bp;
|
|
if (sp->ens_stamplen != sizeof(*sp)) {
|
|
snprintf(pc->errbuf, sizeof(pc->errbuf),
|
|
"pf short stamplen (%d)",
|
|
sp->ens_stamplen);
|
|
return (-1);
|
|
}
|
|
|
|
p = bp + sp->ens_stamplen;
|
|
buflen = sp->ens_count;
|
|
if (buflen > pc->snapshot)
|
|
buflen = pc->snapshot;
|
|
|
|
/* Calculate inc before possible pad update */
|
|
inc = ENALIGN(buflen + sp->ens_stamplen);
|
|
cc -= inc;
|
|
bp += inc;
|
|
pf->TotPkts++;
|
|
pf->TotDrops += sp->ens_dropped;
|
|
pf->TotMissed = sp->ens_ifoverflows;
|
|
if (pf->OrigMissed < 0)
|
|
pf->OrigMissed = pf->TotMissed;
|
|
|
|
/*
|
|
* Short-circuit evaluation: if using BPF filter
|
|
* in kernel, no need to do it now - we already know
|
|
* the packet passed the filter.
|
|
*
|
|
* Note: the filter code was generated assuming
|
|
* that pc->fddipad was the amount of padding
|
|
* before the header, as that's what's required
|
|
* in the kernel, so we run the filter before
|
|
* skipping that padding.
|
|
*/
|
|
if (pf->filtering_in_kernel ||
|
|
pcap_filter(pc->fcode.bf_insns, p, sp->ens_count, buflen)) {
|
|
struct pcap_pkthdr h;
|
|
pf->TotAccepted++;
|
|
h.ts = sp->ens_tstamp;
|
|
h.len = sp->ens_count - pad;
|
|
p += pad;
|
|
buflen -= pad;
|
|
h.caplen = buflen;
|
|
(*callback)(user, &h, p);
|
|
if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) {
|
|
pc->cc = cc;
|
|
pc->bp = bp;
|
|
return (n);
|
|
}
|
|
}
|
|
}
|
|
pc->cc = 0;
|
|
return (n);
|
|
}
|
|
|
|
static int
|
|
pcap_inject_pf(pcap_t *p, const void *buf, int size)
|
|
{
|
|
int ret;
|
|
|
|
ret = write(p->fd, buf, size);
|
|
if (ret == -1) {
|
|
pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
errno, "send");
|
|
return (-1);
|
|
}
|
|
return (ret);
|
|
}
|
|
|
|
static int
|
|
pcap_stats_pf(pcap_t *p, struct pcap_stat *ps)
|
|
{
|
|
struct pcap_pf *pf = p->priv;
|
|
|
|
/*
|
|
* If packet filtering is being done in the kernel:
|
|
*
|
|
* "ps_recv" counts only packets that passed the filter.
|
|
* This does not include packets dropped because we
|
|
* ran out of buffer space. (XXX - perhaps it should,
|
|
* by adding "ps_drop" to "ps_recv", for compatibility
|
|
* with some other platforms. On the other hand, on
|
|
* some platforms "ps_recv" counts only packets that
|
|
* passed the filter, and on others it counts packets
|
|
* that didn't pass the filter....)
|
|
*
|
|
* "ps_drop" counts packets that passed the kernel filter
|
|
* (if any) but were dropped because the input queue was
|
|
* full.
|
|
*
|
|
* "ps_ifdrop" counts packets dropped by the network
|
|
* interface (regardless of whether they would have passed
|
|
* the input filter, of course).
|
|
*
|
|
* If packet filtering is not being done in the kernel:
|
|
*
|
|
* "ps_recv" counts only packets that passed the filter.
|
|
*
|
|
* "ps_drop" counts packets that were dropped because the
|
|
* input queue was full, regardless of whether they passed
|
|
* the userland filter.
|
|
*
|
|
* "ps_ifdrop" counts packets dropped by the network
|
|
* interface (regardless of whether they would have passed
|
|
* the input filter, of course).
|
|
*
|
|
* These statistics don't include packets not yet read from
|
|
* the kernel by libpcap, but they may include packets not
|
|
* yet read from libpcap by the application.
|
|
*/
|
|
ps->ps_recv = pf->TotAccepted;
|
|
ps->ps_drop = pf->TotDrops;
|
|
ps->ps_ifdrop = pf->TotMissed - pf->OrigMissed;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* We include the OS's <net/bpf.h>, not our "pcap/bpf.h", so we probably
|
|
* don't get DLT_DOCSIS defined.
|
|
*/
|
|
#ifndef DLT_DOCSIS
|
|
#define DLT_DOCSIS 143
|
|
#endif
|
|
|
|
static int
|
|
pcap_activate_pf(pcap_t *p)
|
|
{
|
|
struct pcap_pf *pf = p->priv;
|
|
short enmode;
|
|
int backlog = -1; /* request the most */
|
|
struct enfilter Filter;
|
|
struct endevp devparams;
|
|
int err;
|
|
|
|
/*
|
|
* Initially try a read/write open (to allow the inject
|
|
* method to work). If that fails due to permission
|
|
* issues, fall back to read-only. This allows a
|
|
* non-root user to be granted specific access to pcap
|
|
* capabilities via file permissions.
|
|
*
|
|
* XXX - we should have an API that has a flag that
|
|
* controls whether to open read-only or read-write,
|
|
* so that denial of permission to send (or inability
|
|
* to send, if sending packets isn't supported on
|
|
* the device in question) can be indicated at open
|
|
* time.
|
|
*
|
|
* XXX - we assume here that "pfopen()" does not, in fact, modify
|
|
* its argument, even though it takes a "char *" rather than a
|
|
* "const char *" as its first argument. That appears to be
|
|
* the case, at least on Digital UNIX 4.0.
|
|
*
|
|
* XXX - is there an error that means "no such device"? Is
|
|
* there one that means "that device doesn't support pf"?
|
|
*/
|
|
p->fd = pfopen(p->opt.device, O_RDWR);
|
|
if (p->fd == -1 && errno == EACCES)
|
|
p->fd = pfopen(p->opt.device, O_RDONLY);
|
|
if (p->fd < 0) {
|
|
if (errno == EACCES) {
|
|
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"pf open: %s: Permission denied\n"
|
|
"your system may not be properly configured; see the packetfilter(4) man page",
|
|
p->opt.device);
|
|
err = PCAP_ERROR_PERM_DENIED;
|
|
} else {
|
|
pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
errno, "pf open: %s", p->opt.device);
|
|
err = PCAP_ERROR;
|
|
}
|
|
goto bad;
|
|
}
|
|
|
|
/*
|
|
* Turn a negative snapshot value (invalid), a snapshot value of
|
|
* 0 (unspecified), or a value bigger than the normal maximum
|
|
* value, into the maximum allowed value.
|
|
*
|
|
* If some application really *needs* a bigger snapshot
|
|
* length, we should just increase MAXIMUM_SNAPLEN.
|
|
*/
|
|
if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN)
|
|
p->snapshot = MAXIMUM_SNAPLEN;
|
|
|
|
pf->OrigMissed = -1;
|
|
enmode = ENTSTAMP|ENNONEXCL;
|
|
if (!p->opt.immediate)
|
|
enmode |= ENBATCH;
|
|
if (p->opt.promisc)
|
|
enmode |= ENPROMISC;
|
|
if (ioctl(p->fd, EIOCMBIS, (caddr_t)&enmode) < 0) {
|
|
pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
errno, "EIOCMBIS");
|
|
err = PCAP_ERROR;
|
|
goto bad;
|
|
}
|
|
#ifdef ENCOPYALL
|
|
/* Try to set COPYALL mode so that we see packets to ourself */
|
|
enmode = ENCOPYALL;
|
|
(void)ioctl(p->fd, EIOCMBIS, (caddr_t)&enmode);/* OK if this fails */
|
|
#endif
|
|
/* set the backlog */
|
|
if (ioctl(p->fd, EIOCSETW, (caddr_t)&backlog) < 0) {
|
|
pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
errno, "EIOCSETW");
|
|
err = PCAP_ERROR;
|
|
goto bad;
|
|
}
|
|
/* discover interface type */
|
|
if (ioctl(p->fd, EIOCDEVP, (caddr_t)&devparams) < 0) {
|
|
pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
errno, "EIOCDEVP");
|
|
err = PCAP_ERROR;
|
|
goto bad;
|
|
}
|
|
/* HACK: to compile prior to Ultrix 4.2 */
|
|
#ifndef ENDT_FDDI
|
|
#define ENDT_FDDI 4
|
|
#endif
|
|
switch (devparams.end_dev_type) {
|
|
|
|
case ENDT_10MB:
|
|
p->linktype = DLT_EN10MB;
|
|
p->offset = 2;
|
|
/*
|
|
* This is (presumably) a real Ethernet capture; give it a
|
|
* link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
|
|
* that an application can let you choose it, in case you're
|
|
* capturing DOCSIS traffic that a Cisco Cable Modem
|
|
* Termination System is putting out onto an Ethernet (it
|
|
* doesn't put an Ethernet header onto the wire, it puts raw
|
|
* DOCSIS frames out on the wire inside the low-level
|
|
* Ethernet framing).
|
|
*/
|
|
p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
|
|
/*
|
|
* If that fails, just leave the list empty.
|
|
*/
|
|
if (p->dlt_list != NULL) {
|
|
p->dlt_list[0] = DLT_EN10MB;
|
|
p->dlt_list[1] = DLT_DOCSIS;
|
|
p->dlt_count = 2;
|
|
}
|
|
break;
|
|
|
|
case ENDT_FDDI:
|
|
p->linktype = DLT_FDDI;
|
|
break;
|
|
|
|
#ifdef ENDT_SLIP
|
|
case ENDT_SLIP:
|
|
p->linktype = DLT_SLIP;
|
|
break;
|
|
#endif
|
|
|
|
#ifdef ENDT_PPP
|
|
case ENDT_PPP:
|
|
p->linktype = DLT_PPP;
|
|
break;
|
|
#endif
|
|
|
|
#ifdef ENDT_LOOPBACK
|
|
case ENDT_LOOPBACK:
|
|
/*
|
|
* It appears to use Ethernet framing, at least on
|
|
* Digital UNIX 4.0.
|
|
*/
|
|
p->linktype = DLT_EN10MB;
|
|
p->offset = 2;
|
|
break;
|
|
#endif
|
|
|
|
#ifdef ENDT_TRN
|
|
case ENDT_TRN:
|
|
p->linktype = DLT_IEEE802;
|
|
break;
|
|
#endif
|
|
|
|
default:
|
|
/*
|
|
* XXX - what about ENDT_IEEE802? The pfilt.h header
|
|
* file calls this "IEEE 802 networks (non-Ethernet)",
|
|
* but that doesn't specify a specific link layer type;
|
|
* it could be 802.4, or 802.5 (except that 802.5 is
|
|
* ENDT_TRN), or 802.6, or 802.11, or.... That's why
|
|
* DLT_IEEE802 was hijacked to mean Token Ring in various
|
|
* BSDs, and why we went along with that hijacking.
|
|
*
|
|
* XXX - what about ENDT_HDLC and ENDT_NULL?
|
|
* Presumably, as ENDT_OTHER is just "Miscellaneous
|
|
* framing", there's not much we can do, as that
|
|
* doesn't specify a particular type of header.
|
|
*/
|
|
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"unknown data-link type %u", devparams.end_dev_type);
|
|
err = PCAP_ERROR;
|
|
goto bad;
|
|
}
|
|
/* set truncation */
|
|
if (p->linktype == DLT_FDDI) {
|
|
p->fddipad = PCAP_FDDIPAD;
|
|
|
|
/* packetfilter includes the padding in the snapshot */
|
|
p->snapshot += PCAP_FDDIPAD;
|
|
} else
|
|
p->fddipad = 0;
|
|
if (ioctl(p->fd, EIOCTRUNCATE, (caddr_t)&p->snapshot) < 0) {
|
|
pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
errno, "EIOCTRUNCATE");
|
|
err = PCAP_ERROR;
|
|
goto bad;
|
|
}
|
|
/* accept all packets */
|
|
memset(&Filter, 0, sizeof(Filter));
|
|
Filter.enf_Priority = 37; /* anything > 2 */
|
|
Filter.enf_FilterLen = 0; /* means "always true" */
|
|
if (ioctl(p->fd, EIOCSETF, (caddr_t)&Filter) < 0) {
|
|
pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
errno, "EIOCSETF");
|
|
err = PCAP_ERROR;
|
|
goto bad;
|
|
}
|
|
|
|
if (p->opt.timeout != 0) {
|
|
struct timeval timeout;
|
|
timeout.tv_sec = p->opt.timeout / 1000;
|
|
timeout.tv_usec = (p->opt.timeout * 1000) % 1000000;
|
|
if (ioctl(p->fd, EIOCSRTIMEOUT, (caddr_t)&timeout) < 0) {
|
|
pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
errno, "EIOCSRTIMEOUT");
|
|
err = PCAP_ERROR;
|
|
goto bad;
|
|
}
|
|
}
|
|
|
|
p->bufsize = BUFSPACE;
|
|
p->buffer = malloc(p->bufsize + p->offset);
|
|
if (p->buffer == NULL) {
|
|
pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
errno, "malloc");
|
|
err = PCAP_ERROR;
|
|
goto bad;
|
|
}
|
|
|
|
/*
|
|
* "select()" and "poll()" work on packetfilter devices.
|
|
*/
|
|
p->selectable_fd = p->fd;
|
|
|
|
p->read_op = pcap_read_pf;
|
|
p->inject_op = pcap_inject_pf;
|
|
p->setfilter_op = pcap_setfilter_pf;
|
|
p->setdirection_op = NULL; /* Not implemented. */
|
|
p->set_datalink_op = NULL; /* can't change data link type */
|
|
p->getnonblock_op = pcap_getnonblock_fd;
|
|
p->setnonblock_op = pcap_setnonblock_fd;
|
|
p->stats_op = pcap_stats_pf;
|
|
|
|
return (0);
|
|
bad:
|
|
pcap_cleanup_live_common(p);
|
|
return (err);
|
|
}
|
|
|
|
pcap_t *
|
|
pcap_create_interface(const char *device _U_, char *ebuf)
|
|
{
|
|
pcap_t *p;
|
|
|
|
p = PCAP_CREATE_COMMON(ebuf, struct pcap_pf);
|
|
if (p == NULL)
|
|
return (NULL);
|
|
|
|
p->activate_op = pcap_activate_pf;
|
|
return (p);
|
|
}
|
|
|
|
/*
|
|
* XXX - is there an error from pfopen() that means "no such device"?
|
|
* Is there one that means "that device doesn't support pf"?
|
|
*/
|
|
static int
|
|
can_be_bound(const char *name _U_)
|
|
{
|
|
return (1);
|
|
}
|
|
|
|
static int
|
|
get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_)
|
|
{
|
|
/*
|
|
* Nothing we can do other than mark loopback devices as "the
|
|
* connected/disconnected status doesn't apply".
|
|
*
|
|
* XXX - is there a way to find out whether an adapter has
|
|
* something plugged into it?
|
|
*/
|
|
if (*flags & PCAP_IF_LOOPBACK) {
|
|
/*
|
|
* Loopback devices aren't wireless, and "connected"/
|
|
* "disconnected" doesn't apply to them.
|
|
*/
|
|
*flags |= PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE;
|
|
return (0);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
|
|
{
|
|
return (pcap_findalldevs_interfaces(devlistp, errbuf, can_be_bound,
|
|
get_if_flags));
|
|
}
|
|
|
|
static int
|
|
pcap_setfilter_pf(pcap_t *p, struct bpf_program *fp)
|
|
{
|
|
struct pcap_pf *pf = p->priv;
|
|
struct bpf_version bv;
|
|
|
|
/*
|
|
* See if BIOCVERSION works. If not, we assume the kernel doesn't
|
|
* support BPF-style filters (it's not documented in the bpf(7)
|
|
* or packetfiler(7) man pages, but the code used to fail if
|
|
* BIOCSETF worked but BIOCVERSION didn't, and I've seen it do
|
|
* kernel filtering in DU 4.0, so presumably BIOCVERSION works
|
|
* there, at least).
|
|
*/
|
|
if (ioctl(p->fd, BIOCVERSION, (caddr_t)&bv) >= 0) {
|
|
/*
|
|
* OK, we have the version of the BPF interpreter;
|
|
* is it the same major version as us, and the same
|
|
* or better minor version?
|
|
*/
|
|
if (bv.bv_major == BPF_MAJOR_VERSION &&
|
|
bv.bv_minor >= BPF_MINOR_VERSION) {
|
|
/*
|
|
* Yes. Try to install the filter.
|
|
*/
|
|
if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) < 0) {
|
|
pcap_fmt_errmsg_for_errno(p->errbuf,
|
|
sizeof(p->errbuf), errno, "BIOCSETF");
|
|
return (-1);
|
|
}
|
|
|
|
/*
|
|
* OK, that succeeded. We're doing filtering in
|
|
* the kernel. (We assume we don't have a
|
|
* userland filter installed - that'd require
|
|
* a previous version check to have failed but
|
|
* this one to succeed.)
|
|
*
|
|
* XXX - this message should be supplied to the
|
|
* application as a warning of some sort,
|
|
* except that if it's a GUI application, it's
|
|
* not clear that it should be displayed in
|
|
* a window to annoy the user.
|
|
*/
|
|
fprintf(stderr, "tcpdump: Using kernel BPF filter\n");
|
|
pf->filtering_in_kernel = 1;
|
|
|
|
/*
|
|
* Discard any previously-received packets,
|
|
* as they might have passed whatever filter
|
|
* was formerly in effect, but might not pass
|
|
* this filter (BIOCSETF discards packets buffered
|
|
* in the kernel, so you can lose packets in any
|
|
* case).
|
|
*/
|
|
p->cc = 0;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* We can't use the kernel's BPF interpreter; don't give
|
|
* up, just log a message and be inefficient.
|
|
*
|
|
* XXX - this should really be supplied to the application
|
|
* as a warning of some sort.
|
|
*/
|
|
fprintf(stderr,
|
|
"tcpdump: Requires BPF language %d.%d or higher; kernel is %d.%d\n",
|
|
BPF_MAJOR_VERSION, BPF_MINOR_VERSION,
|
|
bv.bv_major, bv.bv_minor);
|
|
}
|
|
|
|
/*
|
|
* We couldn't do filtering in the kernel; do it in userland.
|
|
*/
|
|
if (install_bpf_program(p, fp) < 0)
|
|
return (-1);
|
|
|
|
/*
|
|
* XXX - this message should be supplied by the application as
|
|
* a warning of some sort.
|
|
*/
|
|
fprintf(stderr, "tcpdump: Filtering in user process\n");
|
|
pf->filtering_in_kernel = 0;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Libpcap version string.
|
|
*/
|
|
const char *
|
|
pcap_lib_version(void)
|
|
{
|
|
return (PCAP_VERSION_STRING);
|
|
}
|