+++ /dev/null
-/*
- * 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 overflow 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;
- }
- pcapint_fmt_errmsg_for_errno(pc->errbuf,
- sizeof(pc->errbuf), errno, "pf read");
- return (-1);
- }
- bp = 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 ||
- pcapint_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) {
- pcapint_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 {
- pcapint_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) {
- pcapint_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) {
- pcapint_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) {
- pcapint_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 (p->dlt_list == NULL) {
- pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
- errno, "malloc");
- err = PCAP_ERROR;
- goto bad;
- }
- 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) {
- pcapint_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) {
- pcapint_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) {
- pcapint_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) {
- pcapint_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 = pcapint_getnonblock_fd;
- p->setnonblock_op = pcapint_setnonblock_fd;
- p->stats_op = pcap_stats_pf;
-
- return (0);
- bad:
- pcapint_cleanup_live_common(p);
- return (err);
-}
-
-pcap_t *
-pcapint_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
-pcapint_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
-{
- return (pcapint_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 packetfilter(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) {
- pcapint_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 (pcapint_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);
-}
projects / libpcap / commitdiff
