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1141 lines
30 KiB
C
1141 lines
30 KiB
C
/*
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* Copyright (c) 1993, 1994, 1995, 1996, 1998
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that: (1) source code distributions
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* retain the above copyright notice and this paragraph in its entirety, (2)
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* distributions including binary code include the above copyright notice and
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* this paragraph in its entirety in the documentation or other materials
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* provided with the distribution, and (3) all advertising materials mentioning
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* features or use of this software display the following acknowledgement:
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* ``This product includes software developed by the University of California,
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* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
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* the University nor the names of its contributors may be used to endorse
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* or promote products derived from this software without specific prior
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* written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*/
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#ifndef lint
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static const char rcsid[] _U_ =
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"@(#) $Header: /tcpdump/master/libpcap/pcap-bpf.c,v 1.86.2.4 2005/06/04 02:53:16 guy Exp $ (LBL)";
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#endif
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <sys/param.h> /* optionally get BSD define */
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#include <sys/time.h>
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#include <sys/timeb.h>
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#include <sys/socket.h>
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#include <sys/file.h>
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#include <sys/ioctl.h>
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#include <sys/utsname.h>
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#include <net/if.h>
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#ifdef _AIX
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/*
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* Make "pcap.h" not include "pcap-bpf.h"; we are going to include the
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* native OS version, as we need "struct bpf_config" from it.
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*/
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#define PCAP_DONT_INCLUDE_PCAP_BPF_H
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#include <sys/types.h>
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/*
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* Prevent bpf.h from redefining the DLT_ values to their
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* IFT_ values, as we're going to return the standard libpcap
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* values, not IBM's non-standard IFT_ values.
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*/
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#undef _AIX
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#include <net/bpf.h>
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#define _AIX
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#include <net/if_types.h> /* for IFT_ values */
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#include <sys/sysconfig.h>
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#include <sys/device.h>
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#include <sys/cfgodm.h>
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#include <cf.h>
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#ifdef __64BIT__
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#define domakedev makedev64
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#define getmajor major64
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#define bpf_hdr bpf_hdr32
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#else /* __64BIT__ */
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#define domakedev makedev
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#define getmajor major
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#endif /* __64BIT__ */
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#define BPF_NAME "bpf"
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#define BPF_MINORS 4
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#define DRIVER_PATH "/usr/lib/drivers"
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#define BPF_NODE "/dev/bpf"
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static int bpfloadedflag = 0;
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static int odmlockid = 0;
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#else /* _AIX */
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#include <net/bpf.h>
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#endif /* _AIX */
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#include <ctype.h>
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#include <errno.h>
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#include <netdb.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "pcap-int.h"
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#ifdef HAVE_DAG_API
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#include "pcap-dag.h"
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#endif /* HAVE_DAG_API */
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#ifdef HAVE_OS_PROTO_H
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#include "os-proto.h"
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#endif
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#include "gencode.h" /* for "no_optimize" */
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static int pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp);
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static int pcap_setdirection_bpf(pcap_t *, direction_t);
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static int pcap_set_datalink_bpf(pcap_t *p, int dlt);
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static int
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pcap_stats_bpf(pcap_t *p, struct pcap_stat *ps)
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{
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struct bpf_stat s;
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/*
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* "ps_recv" counts packets handed to the filter, not packets
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* that passed the filter. This includes packets later dropped
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* because we ran out of buffer space.
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*
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* "ps_drop" counts packets dropped inside the BPF device
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* because we ran out of buffer space. It doesn't count
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* packets dropped by the interface driver. It counts
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* only packets that passed the filter.
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*
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* Both statistics include packets not yet read from the kernel
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* by libpcap, and thus not yet seen by the application.
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*/
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if (ioctl(p->fd, BIOCGSTATS, (caddr_t)&s) < 0) {
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snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGSTATS: %s",
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pcap_strerror(errno));
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return (-1);
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}
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ps->ps_recv = s.bs_recv;
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ps->ps_drop = s.bs_drop;
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return (0);
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}
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static int
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pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
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{
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int cc;
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int n = 0;
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register u_char *bp, *ep;
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u_char *datap;
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struct bpf_insn *fcode;
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#ifdef PCAP_FDDIPAD
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register int pad;
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#endif
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fcode = p->md.use_bpf ? NULL : p->fcode.bf_insns;
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again:
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/*
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* Has "pcap_breakloop()" been called?
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*/
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if (p->break_loop) {
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/*
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* Yes - clear the flag that indicates that it
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* has, and return -2 to indicate that we were
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* told to break out of the loop.
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*/
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p->break_loop = 0;
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return (-2);
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}
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cc = p->cc;
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if (p->cc == 0) {
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cc = read(p->fd, (char *)p->buffer, p->bufsize);
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if (cc < 0) {
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/* Don't choke when we get ptraced */
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switch (errno) {
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case EINTR:
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goto again;
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#ifdef _AIX
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case EFAULT:
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/*
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* Sigh. More AIX wonderfulness.
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*
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* For some unknown reason the uiomove()
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* operation in the bpf kernel extension
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* used to copy the buffer into user
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* space sometimes returns EFAULT. I have
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* no idea why this is the case given that
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* a kernel debugger shows the user buffer
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* is correct. This problem appears to
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* be mostly mitigated by the memset of
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* the buffer before it is first used.
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* Very strange.... Shaun Clowes
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*
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* In any case this means that we shouldn't
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* treat EFAULT as a fatal error; as we
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* don't have an API for returning
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* a "some packets were dropped since
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* the last packet you saw" indication,
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* we just ignore EFAULT and keep reading.
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*/
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goto again;
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#endif
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case EWOULDBLOCK:
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return (0);
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#if defined(sun) && !defined(BSD)
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/*
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* Due to a SunOS bug, after 2^31 bytes, the kernel
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* file offset overflows and read fails with EINVAL.
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* The lseek() to 0 will fix things.
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*/
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case EINVAL:
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if (lseek(p->fd, 0L, SEEK_CUR) +
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p->bufsize < 0) {
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(void)lseek(p->fd, 0L, SEEK_SET);
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goto again;
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}
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/* fall through */
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#endif
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}
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snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read: %s",
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pcap_strerror(errno));
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return (-1);
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}
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bp = p->buffer;
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} else
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bp = p->bp;
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/*
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* Loop through each packet.
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*/
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#define bhp ((struct bpf_hdr *)bp)
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ep = bp + cc;
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#ifdef PCAP_FDDIPAD
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pad = p->fddipad;
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#endif
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while (bp < ep) {
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register int caplen, hdrlen;
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/*
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* Has "pcap_breakloop()" been called?
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* If so, return immediately - if we haven't read any
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* packets, clear the flag and return -2 to indicate
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* that we were told to break out of the loop, otherwise
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* leave the flag set, so that the *next* call will break
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* out of the loop without having read any packets, and
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* return the number of packets we've processed so far.
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*/
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if (p->break_loop) {
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if (n == 0) {
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p->break_loop = 0;
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return (-2);
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} else {
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p->bp = bp;
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p->cc = ep - bp;
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return (n);
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}
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}
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caplen = bhp->bh_caplen;
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hdrlen = bhp->bh_hdrlen;
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datap = bp + hdrlen;
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/*
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* Short-circuit evaluation: if using BPF filter
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* in kernel, no need to do it now.
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*
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#ifdef PCAP_FDDIPAD
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* Note: the filter code was generated assuming
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* that p->fddipad was the amount of padding
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* before the header, as that's what's required
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* in the kernel, so we run the filter before
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* skipping that padding.
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#endif
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*/
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if (fcode == NULL ||
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bpf_filter(fcode, datap, bhp->bh_datalen, caplen)) {
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struct pcap_pkthdr pkthdr;
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pkthdr.ts.tv_sec = bhp->bh_tstamp.tv_sec;
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#ifdef _AIX
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/*
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* AIX's BPF returns seconds/nanoseconds time
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* stamps, not seconds/microseconds time stamps.
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*/
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pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec/1000;
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#else
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pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec;
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#endif
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#ifdef PCAP_FDDIPAD
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if (caplen > pad)
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pkthdr.caplen = caplen - pad;
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else
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pkthdr.caplen = 0;
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if (bhp->bh_datalen > pad)
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pkthdr.len = bhp->bh_datalen - pad;
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else
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pkthdr.len = 0;
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datap += pad;
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#else
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pkthdr.caplen = caplen;
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pkthdr.len = bhp->bh_datalen;
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#endif
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(*callback)(user, &pkthdr, datap);
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bp += BPF_WORDALIGN(caplen + hdrlen);
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if (++n >= cnt && cnt > 0) {
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p->bp = bp;
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p->cc = ep - bp;
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return (n);
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}
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} else {
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/*
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* Skip this packet.
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*/
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bp += BPF_WORDALIGN(caplen + hdrlen);
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}
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}
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#undef bhp
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p->cc = 0;
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return (n);
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}
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static int
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pcap_inject_bpf(pcap_t *p, const void *buf, size_t size)
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{
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int ret;
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ret = write(p->fd, buf, size);
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#ifdef __APPLE__
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if (ret == -1 && errno == EAFNOSUPPORT) {
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/*
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* In Mac OS X, there's a bug wherein setting the
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* BIOCSHDRCMPLT flag causes writes to fail; see,
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* for example:
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*
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* http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/BIOCSHDRCMPLT-10.3.3.patch
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*
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* So, if, on OS X, we get EAFNOSUPPORT from the write, we
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* assume it's due to that bug, and turn off that flag
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* and try again. If we succeed, it either means that
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* somebody applied the fix from that URL, or other patches
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* for that bug from
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*
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* http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/
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*
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* and are running a Darwin kernel with those fixes, or
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* that Apple fixed the problem in some OS X release.
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*/
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u_int spoof_eth_src = 0;
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if (ioctl(p->fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) {
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(void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
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"send: can't turn off BIOCSHDRCMPLT: %s",
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pcap_strerror(errno));
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return (-1);
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}
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/*
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* Now try the write again.
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*/
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ret = write(p->fd, buf, size);
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}
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#endif /* __APPLE__ */
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if (ret == -1) {
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snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s",
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pcap_strerror(errno));
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return (-1);
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}
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return (ret);
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}
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#ifdef _AIX
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static int
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bpf_odminit(char *errbuf)
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{
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char *errstr;
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if (odm_initialize() == -1) {
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if (odm_err_msg(odmerrno, &errstr) == -1)
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errstr = "Unknown error";
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
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"bpf_load: odm_initialize failed: %s",
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errstr);
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return (-1);
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}
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if ((odmlockid = odm_lock("/etc/objrepos/config_lock", ODM_WAIT)) == -1) {
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if (odm_err_msg(odmerrno, &errstr) == -1)
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errstr = "Unknown error";
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
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"bpf_load: odm_lock of /etc/objrepos/config_lock failed: %s",
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errstr);
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return (-1);
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}
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return (0);
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}
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|
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static int
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bpf_odmcleanup(char *errbuf)
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{
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char *errstr;
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|
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if (odm_unlock(odmlockid) == -1) {
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if (odm_err_msg(odmerrno, &errstr) == -1)
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errstr = "Unknown error";
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
|
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"bpf_load: odm_unlock failed: %s",
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errstr);
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return (-1);
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}
|
|
|
|
if (odm_terminate() == -1) {
|
|
if (odm_err_msg(odmerrno, &errstr) == -1)
|
|
errstr = "Unknown error";
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
|
|
"bpf_load: odm_terminate failed: %s",
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errstr);
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return (-1);
|
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}
|
|
|
|
return (0);
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}
|
|
|
|
static int
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bpf_load(char *errbuf)
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|
{
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long major;
|
|
int *minors;
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|
int numminors, i, rc;
|
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char buf[1024];
|
|
struct stat sbuf;
|
|
struct bpf_config cfg_bpf;
|
|
struct cfg_load cfg_ld;
|
|
struct cfg_kmod cfg_km;
|
|
|
|
/*
|
|
* This is very very close to what happens in the real implementation
|
|
* but I've fixed some (unlikely) bug situations.
|
|
*/
|
|
if (bpfloadedflag)
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|
return (0);
|
|
|
|
if (bpf_odminit(errbuf) != 0)
|
|
return (-1);
|
|
|
|
major = genmajor(BPF_NAME);
|
|
if (major == -1) {
|
|
snprintf(errbuf, PCAP_ERRBUF_SIZE,
|
|
"bpf_load: genmajor failed: %s", pcap_strerror(errno));
|
|
return (-1);
|
|
}
|
|
|
|
minors = getminor(major, &numminors, BPF_NAME);
|
|
if (!minors) {
|
|
minors = genminor("bpf", major, 0, BPF_MINORS, 1, 1);
|
|
if (!minors) {
|
|
snprintf(errbuf, PCAP_ERRBUF_SIZE,
|
|
"bpf_load: genminor failed: %s",
|
|
pcap_strerror(errno));
|
|
return (-1);
|
|
}
|
|
}
|
|
|
|
if (bpf_odmcleanup(errbuf))
|
|
return (-1);
|
|
|
|
rc = stat(BPF_NODE "0", &sbuf);
|
|
if (rc == -1 && errno != ENOENT) {
|
|
snprintf(errbuf, PCAP_ERRBUF_SIZE,
|
|
"bpf_load: can't stat %s: %s",
|
|
BPF_NODE "0", pcap_strerror(errno));
|
|
return (-1);
|
|
}
|
|
|
|
if (rc == -1 || getmajor(sbuf.st_rdev) != major) {
|
|
for (i = 0; i < BPF_MINORS; i++) {
|
|
sprintf(buf, "%s%d", BPF_NODE, i);
|
|
unlink(buf);
|
|
if (mknod(buf, S_IRUSR | S_IFCHR, domakedev(major, i)) == -1) {
|
|
snprintf(errbuf, PCAP_ERRBUF_SIZE,
|
|
"bpf_load: can't mknod %s: %s",
|
|
buf, pcap_strerror(errno));
|
|
return (-1);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Check if the driver is loaded */
|
|
memset(&cfg_ld, 0x0, sizeof(cfg_ld));
|
|
cfg_ld.path = buf;
|
|
sprintf(cfg_ld.path, "%s/%s", DRIVER_PATH, BPF_NAME);
|
|
if ((sysconfig(SYS_QUERYLOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) ||
|
|
(cfg_ld.kmid == 0)) {
|
|
/* Driver isn't loaded, load it now */
|
|
if (sysconfig(SYS_SINGLELOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) {
|
|
snprintf(errbuf, PCAP_ERRBUF_SIZE,
|
|
"bpf_load: could not load driver: %s",
|
|
strerror(errno));
|
|
return (-1);
|
|
}
|
|
}
|
|
|
|
/* Configure the driver */
|
|
cfg_km.cmd = CFG_INIT;
|
|
cfg_km.kmid = cfg_ld.kmid;
|
|
cfg_km.mdilen = sizeof(cfg_bpf);
|
|
cfg_km.mdiptr = (void *)&cfg_bpf;
|
|
for (i = 0; i < BPF_MINORS; i++) {
|
|
cfg_bpf.devno = domakedev(major, i);
|
|
if (sysconfig(SYS_CFGKMOD, (void *)&cfg_km, sizeof(cfg_km)) == -1) {
|
|
snprintf(errbuf, PCAP_ERRBUF_SIZE,
|
|
"bpf_load: could not configure driver: %s",
|
|
strerror(errno));
|
|
return (-1);
|
|
}
|
|
}
|
|
|
|
bpfloadedflag = 1;
|
|
|
|
return (0);
|
|
}
|
|
#endif
|
|
|
|
static inline int
|
|
bpf_open(pcap_t *p, char *errbuf)
|
|
{
|
|
int fd;
|
|
int n = 0;
|
|
char device[sizeof "/dev/bpf0000000000"];
|
|
|
|
#ifdef _AIX
|
|
/*
|
|
* Load the bpf driver, if it isn't already loaded,
|
|
* and create the BPF device entries, if they don't
|
|
* already exist.
|
|
*/
|
|
if (bpf_load(errbuf) == -1)
|
|
return (-1);
|
|
#endif
|
|
|
|
/*
|
|
* Go through all the minors and find one that isn't in use.
|
|
*/
|
|
do {
|
|
(void)snprintf(device, sizeof(device), "/dev/bpf%d", n++);
|
|
/*
|
|
* 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.
|
|
*/
|
|
fd = open(device, O_RDWR);
|
|
if (fd == -1 && errno == EACCES)
|
|
fd = open(device, O_RDONLY);
|
|
} while (fd < 0 && errno == EBUSY);
|
|
|
|
/*
|
|
* XXX better message for all minors used
|
|
*/
|
|
if (fd < 0)
|
|
snprintf(errbuf, PCAP_ERRBUF_SIZE, "(no devices found) %s: %s",
|
|
device, pcap_strerror(errno));
|
|
|
|
return (fd);
|
|
}
|
|
|
|
/*
|
|
* 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
|
|
|
|
pcap_t *
|
|
pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
|
|
char *ebuf)
|
|
{
|
|
int fd;
|
|
struct ifreq ifr;
|
|
struct bpf_version bv;
|
|
#ifdef BIOCGDLTLIST
|
|
struct bpf_dltlist bdl;
|
|
#endif
|
|
#if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT)
|
|
u_int spoof_eth_src = 1;
|
|
#endif
|
|
u_int v;
|
|
pcap_t *p;
|
|
struct bpf_insn total_insn;
|
|
struct bpf_program total_prog;
|
|
struct utsname osinfo;
|
|
|
|
#ifdef HAVE_DAG_API
|
|
if (strstr(device, "dag")) {
|
|
return dag_open_live(device, snaplen, promisc, to_ms, ebuf);
|
|
}
|
|
#endif /* HAVE_DAG_API */
|
|
|
|
#ifdef BIOCGDLTLIST
|
|
memset(&bdl, 0, sizeof(bdl));
|
|
#endif
|
|
|
|
p = (pcap_t *)malloc(sizeof(*p));
|
|
if (p == NULL) {
|
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
|
|
pcap_strerror(errno));
|
|
return (NULL);
|
|
}
|
|
memset(p, 0, sizeof(*p));
|
|
fd = bpf_open(p, ebuf);
|
|
if (fd < 0)
|
|
goto bad;
|
|
|
|
p->fd = fd;
|
|
p->snapshot = snaplen;
|
|
|
|
if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0) {
|
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCVERSION: %s",
|
|
pcap_strerror(errno));
|
|
goto bad;
|
|
}
|
|
if (bv.bv_major != BPF_MAJOR_VERSION ||
|
|
bv.bv_minor < BPF_MINOR_VERSION) {
|
|
snprintf(ebuf, PCAP_ERRBUF_SIZE,
|
|
"kernel bpf filter out of date");
|
|
goto bad;
|
|
}
|
|
|
|
/*
|
|
* Try finding a good size for the buffer; 32768 may be too
|
|
* big, so keep cutting it in half until we find a size
|
|
* that works, or run out of sizes to try. If the default
|
|
* is larger, don't make it smaller.
|
|
*
|
|
* XXX - there should be a user-accessible hook to set the
|
|
* initial buffer size.
|
|
*/
|
|
if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || v < 32768)
|
|
v = 32768;
|
|
for ( ; v != 0; v >>= 1) {
|
|
/* Ignore the return value - this is because the call fails
|
|
* on BPF systems that don't have kernel malloc. And if
|
|
* the call fails, it's no big deal, we just continue to
|
|
* use the standard buffer size.
|
|
*/
|
|
(void) ioctl(fd, BIOCSBLEN, (caddr_t)&v);
|
|
|
|
(void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
|
|
if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) >= 0)
|
|
break; /* that size worked; we're done */
|
|
|
|
if (errno != ENOBUFS) {
|
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s",
|
|
device, pcap_strerror(errno));
|
|
goto bad;
|
|
}
|
|
}
|
|
|
|
if (v == 0) {
|
|
snprintf(ebuf, PCAP_ERRBUF_SIZE,
|
|
"BIOCSBLEN: %s: No buffer size worked", device);
|
|
goto bad;
|
|
}
|
|
|
|
/* Get the data link layer type. */
|
|
if (ioctl(fd, BIOCGDLT, (caddr_t)&v) < 0) {
|
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCGDLT: %s",
|
|
pcap_strerror(errno));
|
|
goto bad;
|
|
}
|
|
#ifdef _AIX
|
|
/*
|
|
* AIX's BPF returns IFF_ types, not DLT_ types, in BIOCGDLT.
|
|
*/
|
|
switch (v) {
|
|
|
|
case IFT_ETHER:
|
|
case IFT_ISO88023:
|
|
v = DLT_EN10MB;
|
|
break;
|
|
|
|
case IFT_FDDI:
|
|
v = DLT_FDDI;
|
|
break;
|
|
|
|
case IFT_ISO88025:
|
|
v = DLT_IEEE802;
|
|
break;
|
|
|
|
case IFT_LOOP:
|
|
v = DLT_NULL;
|
|
break;
|
|
|
|
default:
|
|
/*
|
|
* We don't know what to map this to yet.
|
|
*/
|
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "unknown interface type %u",
|
|
v);
|
|
goto bad;
|
|
}
|
|
#endif
|
|
#if _BSDI_VERSION - 0 >= 199510
|
|
/* The SLIP and PPP link layer header changed in BSD/OS 2.1 */
|
|
switch (v) {
|
|
|
|
case DLT_SLIP:
|
|
v = DLT_SLIP_BSDOS;
|
|
break;
|
|
|
|
case DLT_PPP:
|
|
v = DLT_PPP_BSDOS;
|
|
break;
|
|
|
|
case 11: /*DLT_FR*/
|
|
v = DLT_FRELAY;
|
|
break;
|
|
|
|
case 12: /*DLT_C_HDLC*/
|
|
v = DLT_CHDLC;
|
|
break;
|
|
}
|
|
#endif
|
|
#ifdef PCAP_FDDIPAD
|
|
if (v == DLT_FDDI)
|
|
p->fddipad = PCAP_FDDIPAD;
|
|
else
|
|
p->fddipad = 0;
|
|
#endif
|
|
p->linktype = v;
|
|
|
|
#ifdef BIOCGDLTLIST
|
|
/*
|
|
* We know the default link type -- now determine all the DLTs
|
|
* this interface supports. If this fails with EINVAL, it's
|
|
* not fatal; we just don't get to use the feature later.
|
|
*/
|
|
if (ioctl(fd, BIOCGDLTLIST, (caddr_t)&bdl) == 0) {
|
|
u_int i;
|
|
int is_ethernet;
|
|
|
|
bdl.bfl_list = (u_int *) malloc(sizeof(u_int) * (bdl.bfl_len + 1));
|
|
if (bdl.bfl_list == NULL) {
|
|
(void)snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
|
|
pcap_strerror(errno));
|
|
goto bad;
|
|
}
|
|
|
|
if (ioctl(fd, BIOCGDLTLIST, (caddr_t)&bdl) < 0) {
|
|
(void)snprintf(ebuf, PCAP_ERRBUF_SIZE,
|
|
"BIOCGDLTLIST: %s", pcap_strerror(errno));
|
|
free(bdl.bfl_list);
|
|
goto bad;
|
|
}
|
|
|
|
/*
|
|
* OK, for real Ethernet devices, add DLT_DOCSIS to the
|
|
* list, 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).
|
|
*
|
|
* A "real Ethernet device" is defined here as a device
|
|
* that has a link-layer type of DLT_EN10MB and that has
|
|
* no alternate link-layer types; that's done to exclude
|
|
* 802.11 interfaces (which might or might not be the
|
|
* right thing to do, but I suspect it is - Ethernet <->
|
|
* 802.11 bridges would probably badly mishandle frames
|
|
* that don't have Ethernet headers).
|
|
*/
|
|
if (p->linktype == DLT_EN10MB) {
|
|
is_ethernet = 1;
|
|
for (i = 0; i < bdl.bfl_len; i++) {
|
|
if (bdl.bfl_list[i] != DLT_EN10MB) {
|
|
is_ethernet = 0;
|
|
break;
|
|
}
|
|
}
|
|
if (is_ethernet) {
|
|
/*
|
|
* We reserved one more slot at the end of
|
|
* the list.
|
|
*/
|
|
bdl.bfl_list[bdl.bfl_len] = DLT_DOCSIS;
|
|
bdl.bfl_len++;
|
|
}
|
|
}
|
|
p->dlt_count = bdl.bfl_len;
|
|
p->dlt_list = bdl.bfl_list;
|
|
} else {
|
|
if (errno != EINVAL) {
|
|
(void)snprintf(ebuf, PCAP_ERRBUF_SIZE,
|
|
"BIOCGDLTLIST: %s", pcap_strerror(errno));
|
|
goto bad;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* If this is an Ethernet device, and we don't have a DLT_ list,
|
|
* give it a list with DLT_EN10MB and DLT_DOCSIS. (That'd give
|
|
* 802.11 interfaces DLT_DOCSIS, which isn't the right thing to
|
|
* do, but there's not much we can do about that without finding
|
|
* some other way of determining whether it's an Ethernet or 802.11
|
|
* device.)
|
|
*/
|
|
if (p->linktype == DLT_EN10MB && p->dlt_count == 0) {
|
|
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;
|
|
}
|
|
}
|
|
|
|
#if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT)
|
|
/*
|
|
* Do a BIOCSHDRCMPLT, if defined, to turn that flag on, so
|
|
* the link-layer source address isn't forcibly overwritten.
|
|
* (Should we ignore errors? Should we do this only if
|
|
* we're open for writing?)
|
|
*
|
|
* XXX - I seem to remember some packet-sending bug in some
|
|
* BSDs - check CVS log for "bpf.c"?
|
|
*/
|
|
if (ioctl(fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) {
|
|
(void)snprintf(ebuf, PCAP_ERRBUF_SIZE,
|
|
"BIOCSHDRCMPLT: %s", pcap_strerror(errno));
|
|
goto bad;
|
|
}
|
|
#endif
|
|
/* set timeout */
|
|
if (to_ms != 0) {
|
|
/*
|
|
* XXX - is this seconds/nanoseconds in AIX?
|
|
* (Treating it as such doesn't fix the timeout
|
|
* problem described below.)
|
|
*/
|
|
struct timeval to;
|
|
to.tv_sec = to_ms / 1000;
|
|
to.tv_usec = (to_ms * 1000) % 1000000;
|
|
if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&to) < 0) {
|
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCSRTIMEOUT: %s",
|
|
pcap_strerror(errno));
|
|
goto bad;
|
|
}
|
|
}
|
|
|
|
#ifdef _AIX
|
|
#ifdef BIOCIMMEDIATE
|
|
/*
|
|
* Darren Reed notes that
|
|
*
|
|
* On AIX (4.2 at least), if BIOCIMMEDIATE is not set, the
|
|
* timeout appears to be ignored and it waits until the buffer
|
|
* is filled before returning. The result of not having it
|
|
* set is almost worse than useless if your BPF filter
|
|
* is reducing things to only a few packets (i.e. one every
|
|
* second or so).
|
|
*
|
|
* so we turn BIOCIMMEDIATE mode on if this is AIX.
|
|
*
|
|
* We don't turn it on for other platforms, as that means we
|
|
* get woken up for every packet, which may not be what we want;
|
|
* in the Winter 1993 USENIX paper on BPF, they say:
|
|
*
|
|
* Since a process might want to look at every packet on a
|
|
* network and the time between packets can be only a few
|
|
* microseconds, it is not possible to do a read system call
|
|
* per packet and BPF must collect the data from several
|
|
* packets and return it as a unit when the monitoring
|
|
* application does a read.
|
|
*
|
|
* which I infer is the reason for the timeout - it means we
|
|
* wait that amount of time, in the hopes that more packets
|
|
* will arrive and we'll get them all with one read.
|
|
*
|
|
* Setting BIOCIMMEDIATE mode on FreeBSD (and probably other
|
|
* BSDs) causes the timeout to be ignored.
|
|
*
|
|
* On the other hand, some platforms (e.g., Linux) don't support
|
|
* timeouts, they just hand stuff to you as soon as it arrives;
|
|
* if that doesn't cause a problem on those platforms, it may
|
|
* be OK to have BIOCIMMEDIATE mode on BSD as well.
|
|
*
|
|
* (Note, though, that applications may depend on the read
|
|
* completing, even if no packets have arrived, when the timeout
|
|
* expires, e.g. GUI applications that have to check for input
|
|
* while waiting for packets to arrive; a non-zero timeout
|
|
* prevents "select()" from working right on FreeBSD and
|
|
* possibly other BSDs, as the timer doesn't start until a
|
|
* "read()" is done, so the timer isn't in effect if the
|
|
* application is blocked on a "select()", and the "select()"
|
|
* doesn't get woken up for a BPF device until the buffer
|
|
* fills up.)
|
|
*/
|
|
v = 1;
|
|
if (ioctl(p->fd, BIOCIMMEDIATE, &v) < 0) {
|
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCIMMEDIATE: %s",
|
|
pcap_strerror(errno));
|
|
goto bad;
|
|
}
|
|
#endif /* BIOCIMMEDIATE */
|
|
#endif /* _AIX */
|
|
|
|
if (promisc) {
|
|
/* set promiscuous mode, okay if it fails */
|
|
if (ioctl(p->fd, BIOCPROMISC, NULL) < 0) {
|
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCPROMISC: %s",
|
|
pcap_strerror(errno));
|
|
}
|
|
}
|
|
|
|
if (ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) {
|
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCGBLEN: %s",
|
|
pcap_strerror(errno));
|
|
goto bad;
|
|
}
|
|
p->bufsize = v;
|
|
p->buffer = (u_char *)malloc(p->bufsize);
|
|
if (p->buffer == NULL) {
|
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
|
|
pcap_strerror(errno));
|
|
goto bad;
|
|
}
|
|
#ifdef _AIX
|
|
/* For some strange reason this seems to prevent the EFAULT
|
|
* problems we have experienced from AIX BPF. */
|
|
memset(p->buffer, 0x0, p->bufsize);
|
|
#endif
|
|
|
|
/*
|
|
* If there's no filter program installed, there's
|
|
* no indication to the kernel of what the snapshot
|
|
* length should be, so no snapshotting is done.
|
|
*
|
|
* Therefore, when we open the device, we install
|
|
* an "accept everything" filter with the specified
|
|
* snapshot length.
|
|
*/
|
|
total_insn.code = (u_short)(BPF_RET | BPF_K);
|
|
total_insn.jt = 0;
|
|
total_insn.jf = 0;
|
|
total_insn.k = snaplen;
|
|
|
|
total_prog.bf_len = 1;
|
|
total_prog.bf_insns = &total_insn;
|
|
if (ioctl(p->fd, BIOCSETF, (caddr_t)&total_prog) < 0) {
|
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s",
|
|
pcap_strerror(errno));
|
|
goto bad;
|
|
}
|
|
|
|
/*
|
|
* On most BPF platforms, either you can do a "select()" or
|
|
* "poll()" on a BPF file descriptor and it works correctly,
|
|
* or you can do it and it will return "readable" if the
|
|
* hold buffer is full but not if the timeout expires *and*
|
|
* a non-blocking read will, if the hold buffer is empty
|
|
* but the store buffer isn't empty, rotate the buffers
|
|
* and return what packets are available.
|
|
*
|
|
* In the latter case, the fact that a non-blocking read
|
|
* will give you the available packets means you can work
|
|
* around the failure of "select()" and "poll()" to wake up
|
|
* and return "readable" when the timeout expires by using
|
|
* the timeout as the "select()" or "poll()" timeout, putting
|
|
* the BPF descriptor into non-blocking mode, and read from
|
|
* it regardless of whether "select()" reports it as readable
|
|
* or not.
|
|
*
|
|
* However, in FreeBSD 4.3 and 4.4, "select()" and "poll()"
|
|
* won't wake up and return "readable" if the timer expires
|
|
* and non-blocking reads return EWOULDBLOCK if the hold
|
|
* buffer is empty, even if the store buffer is non-empty.
|
|
*
|
|
* This means the workaround in question won't work.
|
|
*
|
|
* Therefore, on FreeBSD 4.3 and 4.4, we set "p->selectable_fd"
|
|
* to -1, which means "sorry, you can't use 'select()' or 'poll()'
|
|
* here". On all other BPF platforms, we set it to the FD for
|
|
* the BPF device; in NetBSD, OpenBSD, and Darwin, a non-blocking
|
|
* read will, if the hold buffer is empty and the store buffer
|
|
* isn't empty, rotate the buffers and return what packets are
|
|
* there (and in sufficiently recent versions of OpenBSD
|
|
* "select()" and "poll()" should work correctly).
|
|
*
|
|
* In addition, in Mac OS X 10.4, "select()" and "poll()" don't
|
|
* work on *any* character devices, including BPF devices.
|
|
*
|
|
* XXX - what about AIX?
|
|
*/
|
|
p->selectable_fd = p->fd; /* assume select() works until we know otherwise */
|
|
if (uname(&osinfo) == 0) {
|
|
/*
|
|
* We can check what OS this is.
|
|
*/
|
|
if (strcmp(osinfo.sysname, "FreeBSD") == 0) {
|
|
if (strncmp(osinfo.release, "4.3-", 4) == 0 ||
|
|
strncmp(osinfo.release, "4.4-", 4) == 0)
|
|
p->selectable_fd = -1;
|
|
} else if (strcmp(osinfo.sysname, "Darwin") == 0) {
|
|
if (strncmp(osinfo.release, "8.", 2) == 0)
|
|
p->selectable_fd = -1;
|
|
}
|
|
}
|
|
|
|
p->read_op = pcap_read_bpf;
|
|
p->inject_op = pcap_inject_bpf;
|
|
p->setfilter_op = pcap_setfilter_bpf;
|
|
p->setdirection_op = pcap_setdirection_bpf;
|
|
p->set_datalink_op = pcap_set_datalink_bpf;
|
|
p->getnonblock_op = pcap_getnonblock_fd;
|
|
p->setnonblock_op = pcap_setnonblock_fd;
|
|
p->stats_op = pcap_stats_bpf;
|
|
p->close_op = pcap_close_common;
|
|
|
|
return (p);
|
|
bad:
|
|
(void)close(fd);
|
|
if (p->dlt_list != NULL)
|
|
free(p->dlt_list);
|
|
free(p);
|
|
return (NULL);
|
|
}
|
|
|
|
int
|
|
pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
|
|
{
|
|
#ifdef HAVE_DAG_API
|
|
if (dag_platform_finddevs(alldevsp, errbuf) < 0)
|
|
return (-1);
|
|
#endif /* HAVE_DAG_API */
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp)
|
|
{
|
|
/*
|
|
* It looks that BPF code generated by gen_protochain() is not
|
|
* compatible with some of kernel BPF code (for example BSD/OS 3.1).
|
|
* Take a safer side for now.
|
|
*/
|
|
if (no_optimize) {
|
|
/*
|
|
* XXX - what if we already have a filter in the kernel?
|
|
*/
|
|
if (install_bpf_program(p, fp) < 0)
|
|
return (-1);
|
|
p->md.use_bpf = 0; /* filtering in userland */
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Free any user-mode filter we might happen to have installed.
|
|
*/
|
|
pcap_freecode(&p->fcode);
|
|
|
|
/*
|
|
* Try to install the kernel filter.
|
|
*/
|
|
if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) < 0) {
|
|
snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s",
|
|
pcap_strerror(errno));
|
|
return (-1);
|
|
}
|
|
p->md.use_bpf = 1; /* filtering in the kernel */
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
|
|
/*
|
|
* Set direction flag: Which packets do we accept on a forwarding
|
|
* single device? IN, OUT or both?
|
|
*/
|
|
static int
|
|
pcap_setdirection_bpf(pcap_t *p, direction_t d)
|
|
{
|
|
#ifdef BIOCSSEESENT
|
|
u_int seesent;
|
|
#endif
|
|
|
|
/*
|
|
* We don't support D_OUT.
|
|
*/
|
|
if (d == D_OUT) {
|
|
snprintf(p->errbuf, sizeof(p->errbuf),
|
|
"Setting direction to D_OUT is not supported on BPF");
|
|
return -1;
|
|
}
|
|
#ifdef BIOCSSEESENT
|
|
seesent = (d == D_INOUT);
|
|
if (ioctl(p->fd, BIOCSSEESENT, &seesent) == -1) {
|
|
(void) snprintf(p->errbuf, sizeof(p->errbuf),
|
|
"Cannot set direction to %s: %s",
|
|
(d == D_INOUT) ? "D_INOUT" : "D_IN",
|
|
strerror(errno));
|
|
return (-1);
|
|
}
|
|
return (0);
|
|
#else
|
|
(void) snprintf(p->errbuf, sizeof(p->errbuf),
|
|
"This system doesn't support BIOCSSEESENT, so the direction can't be set");
|
|
return (-1);
|
|
#endif
|
|
}
|
|
|
|
static int
|
|
pcap_set_datalink_bpf(pcap_t *p, int dlt)
|
|
{
|
|
#ifdef BIOCSDLT
|
|
if (ioctl(p->fd, BIOCSDLT, &dlt) == -1) {
|
|
(void) snprintf(p->errbuf, sizeof(p->errbuf),
|
|
"Cannot set DLT %d: %s", dlt, strerror(errno));
|
|
return (-1);
|
|
}
|
|
#endif
|
|
return (0);
|
|
}
|