mirror of
https://github.com/the-tcpdump-group/tcpdump.git
synced 2024-11-24 02:23:27 +08:00
71eb51233f
live captures with a "cooked" (SOCK_DGRAM) rather than a "raw" (SOCK_RAW) PF_PACKET socket; it includes a bunch of the fields from the "struct sockaddr_ll" you get in a "recvfrom()", including the Ethernet protocol field.
512 lines
11 KiB
C
512 lines
11 KiB
C
/*
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* Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
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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 copyright[] =
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"@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997\n\
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The Regents of the University of California. All rights reserved.\n";
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static const char rcsid[] =
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"@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.158 2000-12-21 10:43:24 guy Exp $ (LBL)";
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#endif
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/*
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* tcpdump - monitor tcp/ip traffic on an ethernet.
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*
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* First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
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* Mercilessly hacked and occasionally improved since then via the
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* combined efforts of Van, Steve McCanne and Craig Leres of LBL.
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*/
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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/types.h>
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#include <sys/time.h>
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#include <netinet/in.h>
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#include <pcap.h>
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#include <signal.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 <ctype.h>
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#include "interface.h"
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#include "addrtoname.h"
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#include "machdep.h"
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#include "setsignal.h"
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#include "gmt2local.h"
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int aflag; /* translate network and broadcast addresses */
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int dflag; /* print filter code */
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int eflag; /* print ethernet header */
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int fflag; /* don't translate "foreign" IP address */
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int nflag; /* leave addresses as numbers */
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int Nflag; /* remove domains from printed host names */
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int Oflag = 1; /* run filter code optimizer */
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int pflag; /* don't go promiscuous */
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int qflag; /* quick (shorter) output */
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int Rflag = 1; /* print sequence # field in AH/ESP*/
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int sflag = 0; /* use the libsmi to translate OIDs */
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int Sflag; /* print raw TCP sequence numbers */
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int tflag = 1; /* print packet arrival time */
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int uflag = 0; /* Print undecoded NFS handles */
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int vflag; /* verbose */
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int xflag; /* print packet in hex */
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int Xflag; /* print packet in ascii as well as hex */
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char *espsecret = NULL; /* ESP secret key */
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int packettype;
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char *program_name;
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int32_t thiszone; /* seconds offset from gmt to local time */
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/* Forwards */
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static RETSIGTYPE cleanup(int);
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static void usage(void) __attribute__((noreturn));
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/* Length of saved portion of packet. */
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int snaplen = DEFAULT_SNAPLEN;
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struct printer {
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pcap_handler f;
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int type;
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};
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static struct printer printers[] = {
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{ ether_if_print, DLT_EN10MB },
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{ token_if_print, DLT_IEEE802 },
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#ifdef DLT_LANE8023
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{ lane_if_print, DLT_LANE8023 },
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#endif
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#ifdef DLT_CIP
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{ cip_if_print, DLT_CIP },
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#endif
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#ifdef DLT_ATM_CLIP
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{ cip_if_print, DLT_ATM_CLIP },
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#endif
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{ sl_if_print, DLT_SLIP },
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{ sl_bsdos_if_print, DLT_SLIP_BSDOS },
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{ ppp_if_print, DLT_PPP },
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{ ppp_bsdos_if_print, DLT_PPP_BSDOS },
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{ fddi_if_print, DLT_FDDI },
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{ null_if_print, DLT_NULL },
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#ifdef DLT_LOOP
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{ null_if_print, DLT_LOOP },
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#endif
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{ raw_if_print, DLT_RAW },
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{ atm_if_print, DLT_ATM_RFC1483 },
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#ifdef DLT_C_HDLC
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{ chdlc_if_print, DLT_C_HDLC },
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#endif
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#ifdef DLT_PPP_SERIAL
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{ ppp_hdlc_if_print, DLT_PPP_SERIAL },
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#endif
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#ifdef DLT_LINUX_SLL
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{ sll_if_print, DLT_LINUX_SLL },
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#endif
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{ NULL, 0 },
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};
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static pcap_handler
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lookup_printer(int type)
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{
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struct printer *p;
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for (p = printers; p->f; ++p)
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if (type == p->type)
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return p->f;
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error("unknown data link type %d", type);
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/* NOTREACHED */
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}
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static pcap_t *pd;
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extern int optind;
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extern int opterr;
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extern char *optarg;
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int
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main(int argc, char **argv)
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{
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register int cnt, op, i;
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bpf_u_int32 localnet, netmask;
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register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName;
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pcap_handler printer;
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struct bpf_program fcode;
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RETSIGTYPE (*oldhandler)(int);
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u_char *pcap_userdata;
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char ebuf[PCAP_ERRBUF_SIZE];
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cnt = -1;
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device = NULL;
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infile = NULL;
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RFileName = NULL;
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WFileName = NULL;
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if ((cp = strrchr(argv[0], '/')) != NULL)
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program_name = cp + 1;
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else
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program_name = argv[0];
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if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
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error("%s", ebuf);
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#ifdef LIBSMI
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smiInit("tcpdump");
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#endif
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opterr = 0;
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while (
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(op = getopt(argc, argv, "ac:deE:fF:i:lm:nNOpqr:Rs:StT:uvw:xXY")) != -1)
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switch (op) {
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case 'a':
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++aflag;
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break;
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case 'c':
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cnt = atoi(optarg);
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if (cnt <= 0)
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error("invalid packet count %s", optarg);
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break;
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case 'd':
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++dflag;
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break;
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case 'e':
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++eflag;
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break;
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case 'E':
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#ifndef HAVE_LIBCRYPTO
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warning("crypto code not compiled in");
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#endif
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espsecret = optarg;
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break;
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case 'f':
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++fflag;
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break;
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case 'F':
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infile = optarg;
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break;
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case 'i':
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device = optarg;
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break;
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case 'l':
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#ifdef HAVE_SETLINEBUF
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setlinebuf(stdout);
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#else
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setvbuf(stdout, NULL, _IOLBF, 0);
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#endif
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break;
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case 'n':
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++nflag;
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break;
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case 'N':
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++Nflag;
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break;
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case 'm':
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#ifdef LIBSMI
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if (smiLoadModule(optarg) == 0) {
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error("could not load MIB module %s", optarg);
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}
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sflag = 1;
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#else
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(void)fprintf(stderr, "%s: ignoring option `-m %s' ",
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program_name, optarg);
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(void)fprintf(stderr, "(no libsmi support)\n");
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#endif
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case 'O':
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Oflag = 0;
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break;
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case 'p':
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++pflag;
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break;
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case 'q':
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++qflag;
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break;
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case 'r':
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RFileName = optarg;
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break;
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case 'R':
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Rflag = 0;
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break;
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case 's': {
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char *end;
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snaplen = strtol(optarg, &end, 0);
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if (optarg == end || *end != '\0'
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|| snaplen < 0 || snaplen > 65535)
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error("invalid snaplen %s", optarg);
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else if (snaplen == 0)
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snaplen = 65535;
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break;
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}
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case 'S':
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++Sflag;
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break;
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case 't':
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--tflag;
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break;
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case 'T':
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if (strcasecmp(optarg, "vat") == 0)
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packettype = PT_VAT;
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else if (strcasecmp(optarg, "wb") == 0)
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packettype = PT_WB;
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else if (strcasecmp(optarg, "rpc") == 0)
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packettype = PT_RPC;
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else if (strcasecmp(optarg, "rtp") == 0)
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packettype = PT_RTP;
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else if (strcasecmp(optarg, "rtcp") == 0)
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packettype = PT_RTCP;
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else if (strcasecmp(optarg, "snmp") == 0)
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packettype = PT_SNMP;
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else if (strcasecmp(optarg, "cnfp") == 0)
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packettype = PT_CNFP;
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else
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error("unknown packet type `%s'", optarg);
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break;
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case 'u':
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++uflag;
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break;
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case 'v':
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++vflag;
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break;
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case 'w':
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WFileName = optarg;
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break;
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case 'x':
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++xflag;
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break;
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case 'X':
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++xflag;
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++Xflag;
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break;
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#ifdef YYDEBUG
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case 'Y':
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{
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/* Undocumented flag */
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extern int yydebug;
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yydebug = 1;
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}
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break;
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#endif
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default:
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usage();
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/* NOTREACHED */
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}
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if (aflag && nflag)
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error("-a and -n options are incompatible");
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if (tflag > 0)
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thiszone = gmt2local(0);
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if (RFileName != NULL) {
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/*
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* We don't need network access, so set it back to the user id.
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* Also, this prevents the user from reading anyone's
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* trace file.
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*/
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setuid(getuid());
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pd = pcap_open_offline(RFileName, ebuf);
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if (pd == NULL)
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error("%s", ebuf);
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localnet = 0;
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netmask = 0;
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if (fflag != 0)
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error("-f and -r options are incompatible");
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} else {
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if (device == NULL) {
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device = pcap_lookupdev(ebuf);
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if (device == NULL)
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error("%s", ebuf);
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}
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pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
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if (pd == NULL)
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error("%s", ebuf);
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i = pcap_snapshot(pd);
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if (snaplen < i) {
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warning("snaplen raised from %d to %d", snaplen, i);
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snaplen = i;
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}
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if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
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localnet = 0;
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netmask = 0;
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warning("%s", ebuf);
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}
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/*
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* Let user own process after socket has been opened.
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*/
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setuid(getuid());
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}
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if (infile)
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cmdbuf = read_infile(infile);
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else
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cmdbuf = copy_argv(&argv[optind]);
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if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
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error("%s", pcap_geterr(pd));
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if (dflag) {
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bpf_dump(&fcode, dflag);
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exit(0);
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}
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init_addrtoname(localnet, netmask);
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(void)setsignal(SIGTERM, cleanup);
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(void)setsignal(SIGINT, cleanup);
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/* Cooperate with nohup(1) */
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if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
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(void)setsignal(SIGHUP, oldhandler);
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if (pcap_setfilter(pd, &fcode) < 0)
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error("%s", pcap_geterr(pd));
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if (WFileName) {
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pcap_dumper_t *p = pcap_dump_open(pd, WFileName);
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if (p == NULL)
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error("%s", pcap_geterr(pd));
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printer = pcap_dump;
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pcap_userdata = (u_char *)p;
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} else {
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printer = lookup_printer(pcap_datalink(pd));
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pcap_userdata = 0;
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}
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if (RFileName == NULL) {
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(void)fprintf(stderr, "%s: listening on %s\n",
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program_name, device);
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(void)fflush(stderr);
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}
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if (pcap_loop(pd, cnt, printer, pcap_userdata) < 0) {
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(void)fprintf(stderr, "%s: pcap_loop: %s\n",
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program_name, pcap_geterr(pd));
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exit(1);
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}
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pcap_close(pd);
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exit(0);
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}
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/* make a clean exit on interrupts */
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static RETSIGTYPE
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cleanup(int signo)
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{
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struct pcap_stat stat;
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/* Can't print the summary if reading from a savefile */
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if (pd != NULL && pcap_file(pd) == NULL) {
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(void)fflush(stdout);
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putc('\n', stderr);
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if (pcap_stats(pd, &stat) < 0)
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(void)fprintf(stderr, "pcap_stats: %s\n",
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pcap_geterr(pd));
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else {
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(void)fprintf(stderr, "%d packets received by filter\n",
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stat.ps_recv);
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(void)fprintf(stderr, "%d packets dropped by kernel\n",
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stat.ps_drop);
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}
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}
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exit(0);
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}
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/* Like default_print() but data need not be aligned */
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void
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default_print_unaligned(register const u_char *cp, register u_int length)
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{
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register u_int i, s;
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register int nshorts;
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if (Xflag) {
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ascii_print(cp, length);
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return;
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}
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nshorts = (u_int) length / sizeof(u_short);
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i = 0;
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while (--nshorts >= 0) {
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if ((i++ % 8) == 0)
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(void)printf("\n\t\t\t");
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s = *cp++;
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(void)printf(" %02x%02x", s, *cp++);
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}
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if (length & 1) {
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if ((i % 8) == 0)
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(void)printf("\n\t\t\t");
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(void)printf(" %02x", *cp);
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}
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}
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/*
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* By default, print the packet out in hex.
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*/
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void
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default_print(register const u_char *bp, register u_int length)
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{
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default_print_unaligned(bp, length);
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}
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static void
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usage(void)
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{
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extern char version[];
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extern char pcap_version[];
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(void)fprintf(stderr, "%s version %s\n", program_name, version);
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(void)fprintf(stderr, "libpcap version %s\n", pcap_version);
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(void)fprintf(stderr,
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"Usage: %s [-adeflnNOpqStuvxX] [-c count] [ -F file ]\n", program_name);
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(void)fprintf(stderr,
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"\t\t[ -i interface ] [ -r file ] [ -s snaplen ]\n");
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(void)fprintf(stderr,
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"\t\t[ -T type ] [ -w file ] [ expression ]\n");
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exit(-1);
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}
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