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tcpdump/tcpdump.c
Guy Harris 0d8f07921a Clean up pcap_findalldevs() call to find the first interface. 
If it returns -1, it's an error; report the error.

If it returns 0, but the list is empty, that's not an error in
pcap_findalldevs(); report it explicitly as "no interfaces available for
capture".
2017-09-09 10:39:50 -07:00

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/*
* Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
* 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.
*
* Support for splitting captures into multiple files with a maximum
* file size:
*
* Copyright (c) 2001
* Seth Webster <swebster@sst.ll.mit.edu>
*/
#ifndef lint
static const char copyright[] _U_ =
"@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
The Regents of the University of California. All rights reserved.\n";
#endif
/*
* tcpdump - dump traffic on a network
*
* First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
* Mercilessly hacked and occasionally improved since then via the
* combined efforts of Van, Steve McCanne and Craig Leres of LBL.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
/*
* Some older versions of Mac OS X may ship pcap.h from libpcap 0.6 with a
* libpcap based on 0.8. That means it has pcap_findalldevs() but the
* header doesn't define pcap_if_t, meaning that we can't actually *use*
* pcap_findalldevs().
*/
#ifdef HAVE_PCAP_FINDALLDEVS
#ifndef HAVE_PCAP_IF_T
#undef HAVE_PCAP_FINDALLDEVS
#endif
#endif
#include <netdissect-stdinc.h>
#include <sys/stat.h>
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_LIBCRYPTO
#include <openssl/crypto.h>
#endif
#ifdef HAVE_GETOPT_LONG
#include <getopt.h>
#else
#include "getopt_long.h"
#endif
/* Capsicum-specific code requires macros from <net/bpf.h>, which will fail
* to compile if <pcap.h> has already been included; including the headers
* in the opposite order works fine.
*/
#ifdef HAVE_CAPSICUM
#include <sys/capability.h>
#include <sys/ioccom.h>
#include <net/bpf.h>
#include <libgen.h>
#ifdef HAVE_CASPER
#include <libcasper.h>
#include <casper/cap_dns.h>
#include <sys/nv.h>
#endif /* HAVE_CASPER */
#endif /* HAVE_CAPSICUM */
#include <pcap.h>
#include <signal.h>
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#ifndef _WIN32
#include <sys/wait.h>
#include <sys/resource.h>
#include <pwd.h>
#include <grp.h>
#endif /* _WIN32 */
/* capabilities convenience library */
/* If a code depends on HAVE_LIBCAP_NG, it depends also on HAVE_CAP_NG_H.
* If HAVE_CAP_NG_H is not defined, undefine HAVE_LIBCAP_NG.
* Thus, the later tests are done only on HAVE_LIBCAP_NG.
*/
#ifdef HAVE_LIBCAP_NG
#ifdef HAVE_CAP_NG_H
#include <cap-ng.h>
#else
#undef HAVE_LIBCAP_NG
#endif /* HAVE_CAP_NG_H */
#endif /* HAVE_LIBCAP_NG */
#ifdef __FreeBSD__
#include <sys/sysctl.h>
#endif /* __FreeBSD__ */
#include "netdissect.h"
#include "interface.h"
#include "addrtoname.h"
#include "machdep.h"
#include "setsignal.h"
#include "gmt2local.h"
#include "pcap-missing.h"
#include "ascii_strcasecmp.h"
#include "print.h"
#ifndef PATH_MAX
#define PATH_MAX 1024
#endif
#ifdef SIGINFO
#define SIGNAL_REQ_INFO SIGINFO
#elif SIGUSR1
#define SIGNAL_REQ_INFO SIGUSR1
#endif
static int Bflag; /* buffer size */
static long Cflag; /* rotate dump files after this many bytes */
static int Cflag_count; /* Keep track of which file number we're writing */
static int Dflag; /* list available devices and exit */
/*
* This is exported because, in some versions of libpcap, if libpcap
* is built with optimizer debugging code (which is *NOT* the default
* configuration!), the library *imports*(!) a variable named dflag,
* under the expectation that tcpdump is exporting it, to govern
* how much debugging information to print when optimizing
* the generated BPF code.
*
* This is a horrible hack; newer versions of libpcap don't import
* dflag but, instead, *if* built with optimizer debugging code,
* *export* a routine to set that flag.
*/
int dflag; /* print filter code */
static int Gflag; /* rotate dump files after this many seconds */
static int Gflag_count; /* number of files created with Gflag rotation */
static time_t Gflag_time; /* The last time_t the dump file was rotated. */
static int Lflag; /* list available data link types and exit */
static int Iflag; /* rfmon (monitor) mode */
#ifdef HAVE_PCAP_SET_TSTAMP_TYPE
static int Jflag; /* list available time stamp types */
#endif
static int jflag = -1; /* packet time stamp source */
static int pflag; /* don't go promiscuous */
#ifdef HAVE_PCAP_SETDIRECTION
static int Qflag = -1; /* restrict captured packet by send/receive direction */
#endif
static int Uflag; /* "unbuffered" output of dump files */
static int Wflag; /* recycle output files after this number of files */
static int WflagChars;
static char *zflag = NULL; /* compress each savefile using a specified command (like gzip or bzip2) */
static int immediate_mode;
static int infodelay;
static int infoprint;
char *program_name;
#ifdef HAVE_CASPER
cap_channel_t *capdns;
#endif
/* Forwards */
static NORETURN void error(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
static void warning(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
static NORETURN void exit_tcpdump(int);
static RETSIGTYPE cleanup(int);
static RETSIGTYPE child_cleanup(int);
static void print_version(void);
static void print_usage(void);
static NORETURN void show_tstamp_types_and_exit(pcap_t *, const char *device);
static NORETURN void show_dlts_and_exit(pcap_t *, const char *device);
#ifdef HAVE_PCAP_FINDALLDEVS
static NORETURN void show_devices_and_exit(void);
#endif
static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
static void droproot(const char *, const char *);
#ifdef SIGNAL_REQ_INFO
RETSIGTYPE requestinfo(int);
#endif
#if defined(USE_WIN32_MM_TIMER)
#include <MMsystem.h>
static UINT timer_id;
static void CALLBACK verbose_stats_dump(UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR);
#elif defined(HAVE_ALARM)
static void verbose_stats_dump(int sig);
#endif
static void info(int);
static u_int packets_captured;
#ifdef HAVE_PCAP_FINDALLDEVS
static const struct tok status_flags[] = {
#ifdef PCAP_IF_UP
{ PCAP_IF_UP, "Up" },
#endif
#ifdef PCAP_IF_RUNNING
{ PCAP_IF_RUNNING, "Running" },
#endif
{ PCAP_IF_LOOPBACK, "Loopback" },
{ 0, NULL }
};
#endif
static pcap_t *pd;
static int supports_monitor_mode;
extern int optind;
extern int opterr;
extern char *optarg;
struct dump_info {
char *WFileName;
char *CurrentFileName;
pcap_t *pd;
pcap_dumper_t *p;
#ifdef HAVE_CAPSICUM
int dirfd;
#endif
};
#if defined(HAVE_PCAP_SET_PARSER_DEBUG)
/*
* We have pcap_set_parser_debug() in libpcap; declare it (it's not declared
* by any libpcap header, because it's a special hack, only available if
* libpcap was configured to include it, and only intended for use by
* libpcap developers trying to debug the parser for filter expressions).
*/
#ifdef _WIN32
__declspec(dllimport)
#else /* _WIN32 */
extern
#endif /* _WIN32 */
void pcap_set_parser_debug(int);
#elif defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
/*
* We don't have pcap_set_parser_debug() in libpcap, but we do have
* pcap_debug or yydebug. Make a local version of pcap_set_parser_debug()
* to set the flag, and define HAVE_PCAP_SET_PARSER_DEBUG.
*/
static void
pcap_set_parser_debug(int value)
{
#ifdef HAVE_PCAP_DEBUG
extern int pcap_debug;
pcap_debug = value;
#else /* HAVE_PCAP_DEBUG */
extern int yydebug;
yydebug = value;
#endif /* HAVE_PCAP_DEBUG */
}
#define HAVE_PCAP_SET_PARSER_DEBUG
#endif
#if defined(HAVE_PCAP_SET_OPTIMIZER_DEBUG)
/*
* We have pcap_set_optimizer_debug() in libpcap; declare it (it's not declared
* by any libpcap header, because it's a special hack, only available if
* libpcap was configured to include it, and only intended for use by
* libpcap developers trying to debug the optimizer for filter expressions).
*/
#ifdef _WIN32
__declspec(dllimport)
#else /* _WIN32 */
extern
#endif /* _WIN32 */
void pcap_set_optimizer_debug(int);
#endif
/* VARARGS */
static void
error(const char *fmt, ...)
{
va_list ap;
(void)fprintf(stderr, "%s: ", program_name);
va_start(ap, fmt);
(void)vfprintf(stderr, fmt, ap);
va_end(ap);
if (*fmt) {
fmt += strlen(fmt);
if (fmt[-1] != '\n')
(void)fputc('\n', stderr);
}
exit_tcpdump(1);
/* NOTREACHED */
}
/* VARARGS */
static void
warning(const char *fmt, ...)
{
va_list ap;
(void)fprintf(stderr, "%s: WARNING: ", program_name);
va_start(ap, fmt);
(void)vfprintf(stderr, fmt, ap);
va_end(ap);
if (*fmt) {
fmt += strlen(fmt);
if (fmt[-1] != '\n')
(void)fputc('\n', stderr);
}
}
static void
exit_tcpdump(int status)
{
nd_cleanup();
exit(status);
}
#ifdef HAVE_PCAP_SET_TSTAMP_TYPE
static void
show_tstamp_types_and_exit(pcap_t *pc, const char *device)
{
int n_tstamp_types;
int *tstamp_types = 0;
const char *tstamp_type_name;
int i;
n_tstamp_types = pcap_list_tstamp_types(pc, &tstamp_types);
if (n_tstamp_types < 0)
error("%s", pcap_geterr(pc));
if (n_tstamp_types == 0) {
fprintf(stderr, "Time stamp type cannot be set for %s\n",
device);
exit_tcpdump(0);
}
fprintf(stderr, "Time stamp types for %s (use option -j to set):\n",
device);
for (i = 0; i < n_tstamp_types; i++) {
tstamp_type_name = pcap_tstamp_type_val_to_name(tstamp_types[i]);
if (tstamp_type_name != NULL) {
(void) fprintf(stderr, " %s (%s)\n", tstamp_type_name,
pcap_tstamp_type_val_to_description(tstamp_types[i]));
} else {
(void) fprintf(stderr, " %d\n", tstamp_types[i]);
}
}
pcap_free_tstamp_types(tstamp_types);
exit_tcpdump(0);
}
#endif
static void
show_dlts_and_exit(pcap_t *pc, const char *device)
{
int n_dlts, i;
int *dlts = 0;
const char *dlt_name;
n_dlts = pcap_list_datalinks(pc, &dlts);
if (n_dlts < 0)
error("%s", pcap_geterr(pc));
else if (n_dlts == 0 || !dlts)
error("No data link types.");
/*
* If the interface is known to support monitor mode, indicate
* whether these are the data link types available when not in
* monitor mode, if -I wasn't specified, or when in monitor mode,
* when -I was specified (the link-layer types available in
* monitor mode might be different from the ones available when
* not in monitor mode).
*/
if (supports_monitor_mode)
(void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n",
device,
Iflag ? "when in monitor mode" : "when not in monitor mode");
else
(void) fprintf(stderr, "Data link types for %s (use option -y to set):\n",
device);
for (i = 0; i < n_dlts; i++) {
dlt_name = pcap_datalink_val_to_name(dlts[i]);
if (dlt_name != NULL) {
(void) fprintf(stderr, " %s (%s)", dlt_name,
pcap_datalink_val_to_description(dlts[i]));
/*
* OK, does tcpdump handle that type?
*/
if (!has_printer(dlts[i]))
(void) fprintf(stderr, " (printing not supported)");
fprintf(stderr, "\n");
} else {
(void) fprintf(stderr, " DLT %d (printing not supported)\n",
dlts[i]);
}
}
#ifdef HAVE_PCAP_FREE_DATALINKS
pcap_free_datalinks(dlts);
#endif
exit_tcpdump(0);
}
#ifdef HAVE_PCAP_FINDALLDEVS
static void
show_devices_and_exit (void)
{
pcap_if_t *dev, *devlist;
char ebuf[PCAP_ERRBUF_SIZE];
int i;
if (pcap_findalldevs(&devlist, ebuf) < 0)
error("%s", ebuf);
for (i = 0, dev = devlist; dev != NULL; i++, dev = dev->next) {
printf("%d.%s", i+1, dev->name);
if (dev->description != NULL)
printf(" (%s)", dev->description);
if (dev->flags != 0)
printf(" [%s]", bittok2str(status_flags, "none", dev->flags));
printf("\n");
}
pcap_freealldevs(devlist);
exit_tcpdump(0);
}
#endif /* HAVE_PCAP_FINDALLDEVS */
/*
* Short options.
*
* Note that there we use all letters for short options except for g, k,
* o, and P, and those are used by other versions of tcpdump, and we should
* only use them for the same purposes that the other versions of tcpdump
* use them:
*
* OS X tcpdump uses -g to force non--v output for IP to be on one
* line, making it more "g"repable;
*
* OS X tcpdump uses -k to specify that packet comments in pcap-ng files
* should be printed;
*
* OpenBSD tcpdump uses -o to indicate that OS fingerprinting should be done
* for hosts sending TCP SYN packets;
*
* OS X tcpdump uses -P to indicate that -w should write pcap-ng rather
* than pcap files.
*
* OS X tcpdump also uses -Q to specify expressions that match packet
* metadata, including but not limited to the packet direction.
* The expression syntax is different from a simple "in|out|inout",
* and those expressions aren't accepted by OS X tcpdump, but the
* equivalents would be "in" = "dir=in", "out" = "dir=out", and
* "inout" = "dir=in or dir=out", and the parser could conceivably
* special-case "in", "out", and "inout" as expressions for backwards
* compatibility, so all is not (yet) lost.
*/
/*
* Set up flags that might or might not be supported depending on the
* version of libpcap we're using.
*/
#if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
#define B_FLAG "B:"
#define B_FLAG_USAGE " [ -B size ]"
#else /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
#define B_FLAG
#define B_FLAG_USAGE
#endif /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
#ifdef HAVE_PCAP_CREATE
#define I_FLAG "I"
#else /* HAVE_PCAP_CREATE */
#define I_FLAG
#endif /* HAVE_PCAP_CREATE */
#ifdef HAVE_PCAP_SET_TSTAMP_TYPE
#define j_FLAG "j:"
#define j_FLAG_USAGE " [ -j tstamptype ]"
#define J_FLAG "J"
#else /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
#define j_FLAG
#define j_FLAG_USAGE
#define J_FLAG
#endif /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
#ifdef HAVE_PCAP_FINDALLDEVS
#define D_FLAG "D"
#else
#define D_FLAG
#endif
#ifdef HAVE_PCAP_DUMP_FLUSH
#define U_FLAG "U"
#else
#define U_FLAG
#endif
#ifdef HAVE_PCAP_SETDIRECTION
#define Q_FLAG "Q:"
#else
#define Q_FLAG
#endif
#define SHORTOPTS "aAb" B_FLAG "c:C:d" D_FLAG "eE:fF:G:hHi:" I_FLAG j_FLAG J_FLAG "KlLm:M:nNOpq" Q_FLAG "r:s:StT:u" U_FLAG "vV:w:W:xXy:Yz:Z:#"
/*
* Long options.
*
* We do not currently have long options corresponding to all short
* options; we should probably pick appropriate option names for them.
*
* However, the short options where the number of times the option is
* specified matters, such as -v and -d and -t, should probably not
* just map to a long option, as saying
*
* tcpdump --verbose --verbose
*
* doesn't make sense; it should be --verbosity={N} or something such
* as that.
*
* For long options with no corresponding short options, we define values
* outside the range of ASCII graphic characters, make that the last
* component of the entry for the long option, and have a case for that
* option in the switch statement.
*/
#define OPTION_VERSION 128
#define OPTION_TSTAMP_PRECISION 129
#define OPTION_IMMEDIATE_MODE 130
static const struct option longopts[] = {
#if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
{ "buffer-size", required_argument, NULL, 'B' },
#endif
{ "list-interfaces", no_argument, NULL, 'D' },
{ "help", no_argument, NULL, 'h' },
{ "interface", required_argument, NULL, 'i' },
#ifdef HAVE_PCAP_CREATE
{ "monitor-mode", no_argument, NULL, 'I' },
#endif
#ifdef HAVE_PCAP_SET_TSTAMP_TYPE
{ "time-stamp-type", required_argument, NULL, 'j' },
{ "list-time-stamp-types", no_argument, NULL, 'J' },
#endif
#ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
{ "time-stamp-precision", required_argument, NULL, OPTION_TSTAMP_PRECISION},
#endif
{ "dont-verify-checksums", no_argument, NULL, 'K' },
{ "list-data-link-types", no_argument, NULL, 'L' },
{ "no-optimize", no_argument, NULL, 'O' },
{ "no-promiscuous-mode", no_argument, NULL, 'p' },
#ifdef HAVE_PCAP_SETDIRECTION
{ "direction", required_argument, NULL, 'Q' },
#endif
{ "snapshot-length", required_argument, NULL, 's' },
{ "absolute-tcp-sequence-numbers", no_argument, NULL, 'S' },
#ifdef HAVE_PCAP_DUMP_FLUSH
{ "packet-buffered", no_argument, NULL, 'U' },
#endif
{ "linktype", required_argument, NULL, 'y' },
#ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
{ "immediate-mode", no_argument, NULL, OPTION_IMMEDIATE_MODE },
#endif
#ifdef HAVE_PCAP_SET_PARSER_DEBUG
{ "debug-filter-parser", no_argument, NULL, 'Y' },
#endif
{ "relinquish-privileges", required_argument, NULL, 'Z' },
{ "number", no_argument, NULL, '#' },
{ "version", no_argument, NULL, OPTION_VERSION },
{ NULL, 0, NULL, 0 }
};
#ifndef _WIN32
/* Drop root privileges and chroot if necessary */
static void
droproot(const char *username, const char *chroot_dir)
{
struct passwd *pw = NULL;
if (chroot_dir && !username) {
fprintf(stderr, "%s: Chroot without dropping root is insecure\n",
program_name);
exit_tcpdump(1);
}
pw = getpwnam(username);
if (pw) {
if (chroot_dir) {
if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
fprintf(stderr, "%s: Couldn't chroot/chdir to '%.64s': %s\n",
program_name, chroot_dir, pcap_strerror(errno));
exit_tcpdump(1);
}
}
#ifdef HAVE_LIBCAP_NG
{
int ret = capng_change_id(pw->pw_uid, pw->pw_gid, CAPNG_NO_FLAG);
if (ret < 0) {
fprintf(stderr, "error : ret %d\n", ret);
} else {
fprintf(stderr, "dropped privs to %s\n", username);
}
}
#else
if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) {
fprintf(stderr, "%s: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
program_name, username,
(unsigned long)pw->pw_uid,
(unsigned long)pw->pw_gid,
pcap_strerror(errno));
exit_tcpdump(1);
}
else {
fprintf(stderr, "dropped privs to %s\n", username);
}
#endif /* HAVE_LIBCAP_NG */
}
else {
fprintf(stderr, "%s: Couldn't find user '%.32s'\n",
program_name, username);
exit_tcpdump(1);
}
#ifdef HAVE_LIBCAP_NG
/* We don't need CAP_SETUID, CAP_SETGID and CAP_SYS_CHROOT any more. */
capng_updatev(
CAPNG_DROP,
CAPNG_EFFECTIVE | CAPNG_PERMITTED,
CAP_SETUID,
CAP_SETGID,
CAP_SYS_CHROOT,
-1);
capng_apply(CAPNG_SELECT_BOTH);
#endif /* HAVE_LIBCAP_NG */
}
#endif /* _WIN32 */
static int
getWflagChars(int x)
{
int c = 0;
x -= 1;
while (x > 0) {
c += 1;
x /= 10;
}
return c;
}
static void
MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
{
char *filename = malloc(PATH_MAX + 1);
if (filename == NULL)
error("Makefilename: malloc");
/* Process with strftime if Gflag is set. */
if (Gflag != 0) {
struct tm *local_tm;
/* Convert Gflag_time to a usable format */
if ((local_tm = localtime(&Gflag_time)) == NULL) {
error("MakeTimedFilename: localtime");
}
/* There's no good way to detect an error in strftime since a return
* value of 0 isn't necessarily failure.
*/
strftime(filename, PATH_MAX, orig_name, local_tm);
} else {
strncpy(filename, orig_name, PATH_MAX);
}
if (cnt == 0 && max_chars == 0)
strncpy(buffer, filename, PATH_MAX + 1);
else
if (snprintf(buffer, PATH_MAX + 1, "%s%0*d", filename, max_chars, cnt) > PATH_MAX)
/* Report an error if the filename is too large */
error("too many output files or filename is too long (> %d)", PATH_MAX);
free(filename);
}
static char *
get_next_file(FILE *VFile, char *ptr)
{
char *ret;
ret = fgets(ptr, PATH_MAX, VFile);
if (!ret)
return NULL;
if (ptr[strlen(ptr) - 1] == '\n')
ptr[strlen(ptr) - 1] = '\0';
return ret;
}
#ifdef HAVE_CASPER
static cap_channel_t *
capdns_setup(void)
{
cap_channel_t *capcas, *capdnsloc;
const char *types[1];
int families[2];
capcas = cap_init();
if (capcas == NULL)
error("unable to create casper process");
capdnsloc = cap_service_open(capcas, "system.dns");
/* Casper capability no longer needed. */
cap_close(capcas);
if (capdnsloc == NULL)
error("unable to open system.dns service");
/* Limit system.dns to reverse DNS lookups. */
types[0] = "ADDR";
if (cap_dns_type_limit(capdnsloc, types, 1) < 0)
error("unable to limit access to system.dns service");
families[0] = AF_INET;
families[1] = AF_INET6;
if (cap_dns_family_limit(capdnsloc, families, 2) < 0)
error("unable to limit access to system.dns service");
return (capdnsloc);
}
#endif /* HAVE_CASPER */
#ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
static int
tstamp_precision_from_string(const char *precision)
{
if (strncmp(precision, "nano", strlen("nano")) == 0)
return PCAP_TSTAMP_PRECISION_NANO;
if (strncmp(precision, "micro", strlen("micro")) == 0)
return PCAP_TSTAMP_PRECISION_MICRO;
return -EINVAL;
}
static const char *
tstamp_precision_to_string(int precision)
{
switch (precision) {
case PCAP_TSTAMP_PRECISION_MICRO:
return "micro";
case PCAP_TSTAMP_PRECISION_NANO:
return "nano";
default:
return "unknown";
}
}
#endif
#ifdef HAVE_CAPSICUM
/*
* Ensure that, on a dump file's descriptor, we have all the rights
* necessary to make the standard I/O library work with an fdopen()ed
* FILE * from that descriptor.
*
* A long time ago, in a galaxy far far away, AT&T decided that, instead
* of providing separate APIs for getting and setting the FD_ flags on a
* descriptor, getting and setting the O_ flags on a descriptor, and
* locking files, they'd throw them all into a kitchen-sink fcntl() call
* along the lines of ioctl(), the fact that ioctl() operations are
* largely specific to particular character devices but fcntl() operations
* are either generic to all descriptors or generic to all descriptors for
* regular files nonwithstanding.
*
* The Capsicum people decided that fine-grained control of descriptor
* operations was required, so that you need to grant permission for
* reading, writing, seeking, and fcntl-ing. The latter, courtesy of
* AT&T's decision, means that "fcntl-ing" isn't a thing, but a motley
* collection of things, so there are *individual* fcntls for which
* permission needs to be granted.
*
* The FreeBSD standard I/O people implemented some optimizations that
* requires that the standard I/O routines be able to determine whether
* the descriptor for the FILE * is open append-only or not; as that
* descriptor could have come from an open() rather than an fopen(),
* that requires that it be able to do an F_GETFL fcntl() to read
* the O_ flags.
*
* Tcpdump uses ftell() to determine how much data has been written
* to a file in order to, when used with -C, determine when it's time
* to rotate capture files. ftell() therefore needs to do an lseek()
* to find out the file offset and must, thanks to the aforementioned
* optimization, also know whether the descriptor is open append-only
* or not.
*
* The net result of all the above is that we need to grant CAP_SEEK,
* CAP_WRITE, and CAP_FCNTL with the CAP_FCNTL_GETFL subcapability.
*
* Perhaps this is the universe's way of saying that either
*
* 1) there needs to be an fopenat() call and a pcap_dump_openat() call
* using it, so that Capsicum-capable tcpdump wouldn't need to do
* an fdopen()
*
* or
*
* 2) there needs to be a cap_fdopen() call in the FreeBSD standard
* I/O library that knows what rights are needed by the standard
* I/O library, based on the open mode, and assigns them, perhaps
* with an additional argument indicating, for example, whether
* seeking should be allowed, so that tcpdump doesn't need to know
* what the standard I/O library happens to require this week.
*/
static void
set_dumper_capsicum_rights(pcap_dumper_t *p)
{
int fd = fileno(pcap_dump_file(p));
cap_rights_t rights;
cap_rights_init(&rights, CAP_SEEK, CAP_WRITE, CAP_FCNTL);
if (cap_rights_limit(fd, &rights) < 0 && errno != ENOSYS) {
error("unable to limit dump descriptor");
}
if (cap_fcntls_limit(fd, CAP_FCNTL_GETFL) < 0 && errno != ENOSYS) {
error("unable to limit dump descriptor fcntls");
}
}
#endif
/*
* Copy arg vector into a new buffer, concatenating arguments with spaces.
*/
static char *
copy_argv(register char **argv)
{
register char **p;
register u_int len = 0;
char *buf;
char *src, *dst;
p = argv;
if (*p == NULL)
return 0;
while (*p)
len += strlen(*p++) + 1;
buf = (char *)malloc(len);
if (buf == NULL)
error("copy_argv: malloc");
p = argv;
dst = buf;
while ((src = *p++) != NULL) {
while ((*dst++ = *src++) != '\0')
;
dst[-1] = ' ';
}
dst[-1] = '\0';
return buf;
}
/*
* On Windows, we need to open the file in binary mode, so that
* we get all the bytes specified by the size we get from "fstat()".
* On UNIX, that's not necessary. O_BINARY is defined on Windows;
* we define it as 0 if it's not defined, so it does nothing.
*/
#ifndef O_BINARY
#define O_BINARY 0
#endif
static char *
read_infile(char *fname)
{
register int i, fd, cc;
register char *cp;
struct stat buf;
fd = open(fname, O_RDONLY|O_BINARY);
if (fd < 0)
error("can't open %s: %s", fname, pcap_strerror(errno));
if (fstat(fd, &buf) < 0)
error("can't stat %s: %s", fname, pcap_strerror(errno));
cp = malloc((u_int)buf.st_size + 1);
if (cp == NULL)
error("malloc(%d) for %s: %s", (u_int)buf.st_size + 1,
fname, pcap_strerror(errno));
cc = read(fd, cp, (u_int)buf.st_size);
if (cc < 0)
error("read %s: %s", fname, pcap_strerror(errno));
if (cc != buf.st_size)
error("short read %s (%d != %d)", fname, cc, (int)buf.st_size);
close(fd);
/* replace "# comment" with spaces */
for (i = 0; i < cc; i++) {
if (cp[i] == '#')
while (i < cc && cp[i] != '\n')
cp[i++] = ' ';
}
cp[cc] = '\0';
return (cp);
}
#ifdef HAVE_PCAP_FINDALLDEVS
static long
parse_interface_number(const char *device)
{
long devnum;
char *end;
devnum = strtol(device, &end, 10);
if (device != end && *end == '\0') {
/*
* It's all-numeric, but is it a valid number?
*/
if (devnum <= 0) {
/*
* No, it's not an ordinal.
*/
error("Invalid adapter index");
}
return (devnum);
} else {
/*
* It's not all-numeric; return -1, so our caller
* knows that.
*/
return (-1);
}
}
static char *
find_interface_by_number(long devnum)
{
pcap_if_t *dev, *devlist;
long i;
char ebuf[PCAP_ERRBUF_SIZE];
char *device;
if (pcap_findalldevs(&devlist, ebuf) < 0)
error("%s", ebuf);
/*
* Look for the devnum-th entry in the list of devices (1-based).
*/
for (i = 0, dev = devlist; i < devnum-1 && dev != NULL;
i++, dev = dev->next)
;
if (dev == NULL)
error("Invalid adapter index");
device = strdup(dev->name);
pcap_freealldevs(devlist);
return (device);
}
#endif
static pcap_t *
open_interface(const char *device, netdissect_options *ndo, char *ebuf)
{
pcap_t *pc;
#ifdef HAVE_PCAP_CREATE
int status;
char *cp;
#endif
#ifdef HAVE_PCAP_CREATE
pc = pcap_create(device, ebuf);
if (pc == NULL) {
/*
* If this failed with "No such device", that means
* the interface doesn't exist; return NULL, so that
* the caller can see whether the device name is
* actually an interface index.
*/
if (strstr(ebuf, "No such device") != NULL)
return (NULL);
error("%s", ebuf);
}
#ifdef HAVE_PCAP_SET_TSTAMP_TYPE
if (Jflag)
show_tstamp_types_and_exit(pc, device);
#endif
#ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
status = pcap_set_tstamp_precision(pc, ndo->ndo_tstamp_precision);
if (status != 0)
error("%s: Can't set %ssecond time stamp precision: %s",
device,
tstamp_precision_to_string(ndo->ndo_tstamp_precision),
pcap_statustostr(status));
#endif
#ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
if (immediate_mode) {
status = pcap_set_immediate_mode(pc, 1);
if (status != 0)
error("%s: Can't set immediate mode: %s",
device,
pcap_statustostr(status));
}
#endif
/*
* Is this an interface that supports monitor mode?
*/
if (pcap_can_set_rfmon(pc) == 1)
supports_monitor_mode = 1;
else
supports_monitor_mode = 0;
if (ndo->ndo_snaplen != 0) {
/*
* A snapshot length was explicitly specified;
* use it.
*/
status = pcap_set_snaplen(pc, ndo->ndo_snaplen);
if (status != 0)
error("%s: Can't set snapshot length: %s",
device, pcap_statustostr(status));
}
status = pcap_set_promisc(pc, !pflag);
if (status != 0)
error("%s: Can't set promiscuous mode: %s",
device, pcap_statustostr(status));
if (Iflag) {
status = pcap_set_rfmon(pc, 1);
if (status != 0)
error("%s: Can't set monitor mode: %s",
device, pcap_statustostr(status));
}
status = pcap_set_timeout(pc, 1000);
if (status != 0)
error("%s: pcap_set_timeout failed: %s",
device, pcap_statustostr(status));
if (Bflag != 0) {
status = pcap_set_buffer_size(pc, Bflag);
if (status != 0)
error("%s: Can't set buffer size: %s",
device, pcap_statustostr(status));
}
#ifdef HAVE_PCAP_SET_TSTAMP_TYPE
if (jflag != -1) {
status = pcap_set_tstamp_type(pc, jflag);
if (status < 0)
error("%s: Can't set time stamp type: %s",
device, pcap_statustostr(status));
}
#endif
status = pcap_activate(pc);
if (status < 0) {
/*
* pcap_activate() failed.
*/
cp = pcap_geterr(pc);
if (status == PCAP_ERROR)
error("%s", cp);
else if (status == PCAP_ERROR_NO_SUCH_DEVICE) {
/*
* Return an error for our caller to handle.
*/
snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s\n(%s)",
device, pcap_statustostr(status), cp);
pcap_close(pc);
return (NULL);
} else if (status == PCAP_ERROR_PERM_DENIED && *cp != '\0')
error("%s: %s\n(%s)", device,
pcap_statustostr(status), cp);
#ifdef __FreeBSD__
else if (status == PCAP_ERROR_RFMON_NOTSUP &&
strncmp(device, "wlan", 4) == 0) {
char parent[8], newdev[8];
char sysctl[32];
size_t s = sizeof(parent);
snprintf(sysctl, sizeof(sysctl),
"net.wlan.%d.%%parent", atoi(device + 4));
sysctlbyname(sysctl, parent, &s, NULL, 0);
strlcpy(newdev, device, sizeof(newdev));
/* Suggest a new wlan device. */
/* FIXME: incrementing the index this way is not going to work well
* when the index is 9 or greater but the only consequence in this
* specific case would be an error message that looks a bit odd.
*/
newdev[strlen(newdev)-1]++;
error("%s is not a monitor mode VAP\n"
"To create a new monitor mode VAP use:\n"
" ifconfig %s create wlandev %s wlanmode monitor\n"
"and use %s as the tcpdump interface",
device, newdev, parent, newdev);
}
#endif
else
error("%s: %s", device,
pcap_statustostr(status));
} else if (status > 0) {
/*
* pcap_activate() succeeded, but it's warning us
* of a problem it had.
*/
cp = pcap_geterr(pc);
if (status == PCAP_WARNING)
warning("%s", cp);
else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
*cp != '\0')
warning("%s: %s\n(%s)", device,
pcap_statustostr(status), cp);
else
warning("%s: %s", device,
pcap_statustostr(status));
}
#ifdef HAVE_PCAP_SETDIRECTION
if (Qflag != -1) {
status = pcap_setdirection(pc, Qflag);
if (status != 0)
error("%s: pcap_setdirection() failed: %s",
device, pcap_geterr(pc));
}
#endif /* HAVE_PCAP_SETDIRECTION */
#else /* HAVE_PCAP_CREATE */
*ebuf = '\0';
/*
* If no snapshot length was specified, or a length of 0 was
* specified, default to 256KB.
*/
if (ndo->ndo_snaplen == 0)
ndo->ndo_snaplen = 262144;
pc = pcap_open_live(device, ndo->ndo_snaplen, !pflag, 1000, ebuf);
if (pc == NULL) {
/*
* If this failed with "No such device", that means
* the interface doesn't exist; return NULL, so that
* the caller can see whether the device name is
* actually an interface index.
*/
if (strstr(ebuf, "No such device") != NULL)
return (NULL);
error("%s", ebuf);
}
if (*ebuf)
warning("%s", ebuf);
#endif /* HAVE_PCAP_CREATE */
return (pc);
}
int
main(int argc, char **argv)
{
register int cnt, op, i;
bpf_u_int32 localnet =0 , netmask = 0;
int timezone_offset = 0;
register char *cp, *infile, *cmdbuf, *device, *RFileName, *VFileName, *WFileName;
pcap_handler callback;
int dlt;
const char *dlt_name;
struct bpf_program fcode;
#ifndef _WIN32
RETSIGTYPE (*oldhandler)(int);
#endif
struct dump_info dumpinfo;
u_char *pcap_userdata;
char ebuf[PCAP_ERRBUF_SIZE];
char VFileLine[PATH_MAX + 1];
char *username = NULL;
char *chroot_dir = NULL;
char *ret = NULL;
char *end;
#ifdef HAVE_PCAP_FINDALLDEVS
pcap_if_t *devlist;
long devnum;
#endif
int status;
FILE *VFile;
#ifdef HAVE_CAPSICUM
cap_rights_t rights;
int cansandbox;
#endif /* HAVE_CAPSICUM */
int Oflag = 1; /* run filter code optimizer */
int yflag_dlt = -1;
const char *yflag_dlt_name = NULL;
netdissect_options Ndo;
netdissect_options *ndo = &Ndo;
/*
* Initialize the netdissect code.
*/
if (nd_init(ebuf, sizeof ebuf) == -1)
error("%s", ebuf);
memset(ndo, 0, sizeof(*ndo));
ndo_set_function_pointers(ndo);
cnt = -1;
device = NULL;
infile = NULL;
RFileName = NULL;
VFileName = NULL;
VFile = NULL;
WFileName = NULL;
dlt = -1;
if ((cp = strrchr(argv[0], '/')) != NULL)
ndo->program_name = program_name = cp + 1;
else
ndo->program_name = program_name = argv[0];
#ifdef _WIN32
if (pcap_wsockinit() != 0)
error("Attempting to initialize Winsock failed");
#endif /* _WIN32 */
/*
* On platforms where the CPU doesn't support unaligned loads,
* force unaligned accesses to abort with SIGBUS, rather than
* being fixed up (slowly) by the OS kernel; on those platforms,
* misaligned accesses are bugs, and we want tcpdump to crash so
* that the bugs are reported.
*/
if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
error("%s", ebuf);
while (
(op = getopt_long(argc, argv, SHORTOPTS, longopts, NULL)) != -1)
switch (op) {
case 'a':
/* compatibility for old -a */
break;
case 'A':
++ndo->ndo_Aflag;
break;
case 'b':
++ndo->ndo_bflag;
break;
#if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
case 'B':
Bflag = atoi(optarg)*1024;
if (Bflag <= 0)
error("invalid packet buffer size %s", optarg);
break;
#endif /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
case 'c':
cnt = atoi(optarg);
if (cnt <= 0)
error("invalid packet count %s", optarg);
break;
case 'C':
Cflag = atoi(optarg) * 1000000;
if (Cflag <= 0)
error("invalid file size %s", optarg);
break;
case 'd':
++dflag;
break;
case 'D':
Dflag++;
break;
case 'L':
Lflag++;
break;
case 'e':
++ndo->ndo_eflag;
break;
case 'E':
#ifndef HAVE_LIBCRYPTO
warning("crypto code not compiled in");
#endif
ndo->ndo_espsecret = optarg;
break;
case 'f':
++ndo->ndo_fflag;
break;
case 'F':
infile = optarg;
break;
case 'G':
Gflag = atoi(optarg);
if (Gflag < 0)
error("invalid number of seconds %s", optarg);
/* We will create one file initially. */
Gflag_count = 0;
/* Grab the current time for rotation use. */
if ((Gflag_time = time(NULL)) == (time_t)-1) {
error("main: can't get current time: %s",
pcap_strerror(errno));
}
break;
case 'h':
print_usage();
exit_tcpdump(0);
break;
case 'H':
++ndo->ndo_Hflag;
break;
case 'i':
device = optarg;
break;
#ifdef HAVE_PCAP_CREATE
case 'I':
++Iflag;
break;
#endif /* HAVE_PCAP_CREATE */
#ifdef HAVE_PCAP_SET_TSTAMP_TYPE
case 'j':
jflag = pcap_tstamp_type_name_to_val(optarg);
if (jflag < 0)
error("invalid time stamp type %s", optarg);
break;
case 'J':
Jflag++;
break;
#endif
case 'l':
#ifdef _WIN32
/*
* _IOLBF is the same as _IOFBF in Microsoft's C
* libraries; the only alternative they offer
* is _IONBF.
*
* XXX - this should really be checking for MSVC++,
* not _WIN32, if, for example, MinGW has its own
* C library that is more UNIX-compatible.
*/
setvbuf(stdout, NULL, _IONBF, 0);
#else /* _WIN32 */
#ifdef HAVE_SETLINEBUF
setlinebuf(stdout);
#else
setvbuf(stdout, NULL, _IOLBF, 0);
#endif
#endif /* _WIN32 */
break;
case 'K':
++ndo->ndo_Kflag;
break;
case 'm':
if (nd_have_smi_support()) {
if (nd_load_smi_module(optarg, ebuf, sizeof ebuf) == -1)
error("%s", ebuf);
} else {
(void)fprintf(stderr, "%s: ignoring option `-m %s' ",
program_name, optarg);
(void)fprintf(stderr, "(no libsmi support)\n");
}
break;
case 'M':
/* TCP-MD5 shared secret */
#ifndef HAVE_LIBCRYPTO
warning("crypto code not compiled in");
#endif
ndo->ndo_sigsecret = optarg;
break;
case 'n':
++ndo->ndo_nflag;
break;
case 'N':
++ndo->ndo_Nflag;
break;
case 'O':
Oflag = 0;
break;
case 'p':
++pflag;
break;
case 'q':
++ndo->ndo_qflag;
++ndo->ndo_suppress_default_print;
break;
#ifdef HAVE_PCAP_SETDIRECTION
case 'Q':
if (ascii_strcasecmp(optarg, "in") == 0)
Qflag = PCAP_D_IN;
else if (ascii_strcasecmp(optarg, "out") == 0)
Qflag = PCAP_D_OUT;
else if (ascii_strcasecmp(optarg, "inout") == 0)
Qflag = PCAP_D_INOUT;
else
error("unknown capture direction `%s'", optarg);
break;
#endif /* HAVE_PCAP_SETDIRECTION */
case 'r':
RFileName = optarg;
break;
case 's':
ndo->ndo_snaplen = strtol(optarg, &end, 0);
if (optarg == end || *end != '\0'
|| ndo->ndo_snaplen < 0 || ndo->ndo_snaplen > MAXIMUM_SNAPLEN)
error("invalid snaplen %s", optarg);
break;
case 'S':
++ndo->ndo_Sflag;
break;
case 't':
++ndo->ndo_tflag;
break;
case 'T':
if (ascii_strcasecmp(optarg, "vat") == 0)
ndo->ndo_packettype = PT_VAT;
else if (ascii_strcasecmp(optarg, "wb") == 0)
ndo->ndo_packettype = PT_WB;
else if (ascii_strcasecmp(optarg, "rpc") == 0)
ndo->ndo_packettype = PT_RPC;
else if (ascii_strcasecmp(optarg, "rtp") == 0)
ndo->ndo_packettype = PT_RTP;
else if (ascii_strcasecmp(optarg, "rtcp") == 0)
ndo->ndo_packettype = PT_RTCP;
else if (ascii_strcasecmp(optarg, "snmp") == 0)
ndo->ndo_packettype = PT_SNMP;
else if (ascii_strcasecmp(optarg, "cnfp") == 0)
ndo->ndo_packettype = PT_CNFP;
else if (ascii_strcasecmp(optarg, "tftp") == 0)
ndo->ndo_packettype = PT_TFTP;
else if (ascii_strcasecmp(optarg, "aodv") == 0)
ndo->ndo_packettype = PT_AODV;
else if (ascii_strcasecmp(optarg, "carp") == 0)
ndo->ndo_packettype = PT_CARP;
else if (ascii_strcasecmp(optarg, "radius") == 0)
ndo->ndo_packettype = PT_RADIUS;
else if (ascii_strcasecmp(optarg, "zmtp1") == 0)
ndo->ndo_packettype = PT_ZMTP1;
else if (ascii_strcasecmp(optarg, "vxlan") == 0)
ndo->ndo_packettype = PT_VXLAN;
else if (ascii_strcasecmp(optarg, "pgm") == 0)
ndo->ndo_packettype = PT_PGM;
else if (ascii_strcasecmp(optarg, "pgm_zmtp1") == 0)
ndo->ndo_packettype = PT_PGM_ZMTP1;
else if (ascii_strcasecmp(optarg, "lmp") == 0)
ndo->ndo_packettype = PT_LMP;
else if (ascii_strcasecmp(optarg, "resp") == 0)
ndo->ndo_packettype = PT_RESP;
else
error("unknown packet type `%s'", optarg);
break;
case 'u':
++ndo->ndo_uflag;
break;
#ifdef HAVE_PCAP_DUMP_FLUSH
case 'U':
++Uflag;
break;
#endif
case 'v':
++ndo->ndo_vflag;
break;
case 'V':
VFileName = optarg;
break;
case 'w':
WFileName = optarg;
break;
case 'W':
Wflag = atoi(optarg);
if (Wflag <= 0)
error("invalid number of output files %s", optarg);
WflagChars = getWflagChars(Wflag);
break;
case 'x':
++ndo->ndo_xflag;
++ndo->ndo_suppress_default_print;
break;
case 'X':
++ndo->ndo_Xflag;
++ndo->ndo_suppress_default_print;
break;
case 'y':
yflag_dlt_name = optarg;
yflag_dlt =
pcap_datalink_name_to_val(yflag_dlt_name);
if (yflag_dlt < 0)
error("invalid data link type %s", yflag_dlt_name);
break;
#ifdef HAVE_PCAP_SET_PARSER_DEBUG
case 'Y':
{
/* Undocumented flag */
pcap_set_parser_debug(1);
}
break;
#endif
case 'z':
zflag = optarg;
break;
case 'Z':
username = optarg;
break;
case '#':
ndo->ndo_packet_number = 1;
break;
case OPTION_VERSION:
print_version();
exit_tcpdump(0);
break;
#ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
case OPTION_TSTAMP_PRECISION:
ndo->ndo_tstamp_precision = tstamp_precision_from_string(optarg);
if (ndo->ndo_tstamp_precision < 0)
error("unsupported time stamp precision");
break;
#endif
#ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
case OPTION_IMMEDIATE_MODE:
immediate_mode = 1;
break;
#endif
default:
print_usage();
exit_tcpdump(1);
/* NOTREACHED */
}
#ifdef HAVE_PCAP_FINDALLDEVS
if (Dflag)
show_devices_and_exit();
#endif
switch (ndo->ndo_tflag) {
case 0: /* Default */
case 4: /* Default + Date*/
timezone_offset = gmt2local(0);
break;
case 1: /* No time stamp */
case 2: /* Unix timeval style */
case 3: /* Microseconds since previous packet */
case 5: /* Microseconds since first packet */
break;
default: /* Not supported */
error("only -t, -tt, -ttt, -tttt and -ttttt are supported");
break;
}
if (ndo->ndo_fflag != 0 && (VFileName != NULL || RFileName != NULL))
error("-f can not be used with -V or -r");
if (VFileName != NULL && RFileName != NULL)
error("-V and -r are mutually exclusive.");
#ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
/*
* If we're printing dissected packets to the standard output
* rather than saving raw packets to a file, and the standard
* output is a terminal, use immediate mode, as the user's
* probably expecting to see packets pop up immediately.
*/
if (WFileName == NULL && isatty(1))
immediate_mode = 1;
#endif
#ifdef WITH_CHROOT
/* if run as root, prepare for chrooting */
if (getuid() == 0 || geteuid() == 0) {
/* future extensibility for cmd-line arguments */
if (!chroot_dir)
chroot_dir = WITH_CHROOT;
}
#endif
#ifdef WITH_USER
/* if run as root, prepare for dropping root privileges */
if (getuid() == 0 || geteuid() == 0) {
/* Run with '-Z root' to restore old behaviour */
if (!username)
username = WITH_USER;
}
#endif
if (RFileName != NULL || VFileName != NULL) {
/*
* If RFileName is non-null, it's the pathname of a
* savefile to read. If VFileName is non-null, it's
* the pathname of a file containing a list of pathnames
* (one per line) of savefiles to read.
*
* In either case, we're reading a savefile, not doing
* a live capture.
*/
#ifndef _WIN32
/*
* We don't need network access, so relinquish any set-UID
* or set-GID privileges we have (if any).
*
* We do *not* want set-UID privileges when opening a
* trace file, as that might let the user read other
* people's trace files (especially if we're set-UID
* root).
*/
if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
fprintf(stderr, "Warning: setgid/setuid failed !\n");
#endif /* _WIN32 */
if (VFileName != NULL) {
if (VFileName[0] == '-' && VFileName[1] == '\0')
VFile = stdin;
else
VFile = fopen(VFileName, "r");
if (VFile == NULL)
error("Unable to open file: %s\n", pcap_strerror(errno));
ret = get_next_file(VFile, VFileLine);
if (!ret)
error("Nothing in %s\n", VFileName);
RFileName = VFileLine;
}
#ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
pd = pcap_open_offline_with_tstamp_precision(RFileName,
ndo->ndo_tstamp_precision, ebuf);
#else
pd = pcap_open_offline(RFileName, ebuf);
#endif
if (pd == NULL)
error("%s", ebuf);
#ifdef HAVE_CAPSICUM
cap_rights_init(&rights, CAP_READ);
if (cap_rights_limit(fileno(pcap_file(pd)), &rights) < 0 &&
errno != ENOSYS) {
error("unable to limit pcap descriptor");
}
#endif
dlt = pcap_datalink(pd);
dlt_name = pcap_datalink_val_to_name(dlt);
if (dlt_name == NULL) {
fprintf(stderr, "reading from file %s, link-type %u\n",
RFileName, dlt);
} else {
fprintf(stderr,
"reading from file %s, link-type %s (%s)\n",
RFileName, dlt_name,
pcap_datalink_val_to_description(dlt));
}
} else {
/*
* We're doing a live capture.
*/
if (device == NULL) {
/*
* No interface was specified. Pick one.
*/
#ifdef HAVE_PCAP_FINDALLDEVS
/*
* Find the list of interfaces, and pick
* the first interface.
*/
if (pcap_findalldevs(&devlist, ebuf) == -1)
error("%s", ebuf);
if (devlist == NULL)
error("no interfaces available for capture");
device = strdup(devlist->name);
pcap_freealldevs(devlist);
#else /* HAVE_PCAP_FINDALLDEVS */
/*
* Use whatever interface pcap_lookupdev()
* chooses.
*/
device = pcap_lookupdev(ebuf);
if (device == NULL)
error("%s", ebuf);
#endif
}
/*
* Try to open the interface with the specified name.
*/
pd = open_interface(device, ndo, ebuf);
if (pd == NULL) {
/*
* That failed. If we can get a list of
* interfaces, and the interface name
* is purely numeric, try to use it as
* a 1-based index in the list of
* interfaces.
*/
#ifdef HAVE_PCAP_FINDALLDEVS
devnum = parse_interface_number(device);
if (devnum == -1) {
/*
* It's not a number; just report
* the open error and fail.
*/
error("%s", ebuf);
}
/*
* OK, it's a number; try to find the
* interface with that index, and try
* to open it.
*
* find_interface_by_number() exits if it
* couldn't be found.
*/
device = find_interface_by_number(devnum);
pd = open_interface(device, ndo, ebuf);
if (pd == NULL)
error("%s", ebuf);
#else /* HAVE_PCAP_FINDALLDEVS */
/*
* We can't get a list of interfaces; just
* fail.
*/
error("%s", ebuf);
#endif /* HAVE_PCAP_FINDALLDEVS */
}
/*
* Let user own process after capture device has
* been opened.
*/
#ifndef _WIN32
if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
fprintf(stderr, "Warning: setgid/setuid failed !\n");
#endif /* _WIN32 */
#if !defined(HAVE_PCAP_CREATE) && defined(_WIN32)
if(Bflag != 0)
if(pcap_setbuff(pd, Bflag)==-1){
error("%s", pcap_geterr(pd));
}
#endif /* !defined(HAVE_PCAP_CREATE) && defined(_WIN32) */
if (Lflag)
show_dlts_and_exit(pd, device);
if (yflag_dlt >= 0) {
#ifdef HAVE_PCAP_SET_DATALINK
if (pcap_set_datalink(pd, yflag_dlt) < 0)
error("%s", pcap_geterr(pd));
#else
/*
* We don't actually support changing the
* data link type, so we only let them
* set it to what it already is.
*/
if (yflag_dlt != pcap_datalink(pd)) {
error("%s is not one of the DLTs supported by this device\n",
yflag_dlt_name);
}
#endif
(void)fprintf(stderr, "%s: data link type %s\n",
program_name, yflag_dlt_name);
(void)fflush(stderr);
}
i = pcap_snapshot(pd);
if (ndo->ndo_snaplen < i) {
if (ndo->ndo_snaplen != 0)
warning("snaplen raised from %d to %d", ndo->ndo_snaplen, i);
ndo->ndo_snaplen = i;
} else if (ndo->ndo_snaplen > i) {
warning("snaplen lowered from %d to %d", ndo->ndo_snaplen, i);
ndo->ndo_snaplen = i;
}
if(ndo->ndo_fflag != 0) {
if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
warning("foreign (-f) flag used but: %s", ebuf);
}
}
}
if (infile)
cmdbuf = read_infile(infile);
else
cmdbuf = copy_argv(&argv[optind]);
#ifdef HAVE_PCAP_SET_OPTIMIZER_DEBUG
pcap_set_optimizer_debug(dflag);
#endif
if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
error("%s", pcap_geterr(pd));
if (dflag) {
bpf_dump(&fcode, dflag);
pcap_close(pd);
free(cmdbuf);
pcap_freecode(&fcode);
exit_tcpdump(0);
}
#ifdef HAVE_CASPER
if (!ndo->ndo_nflag)
capdns = capdns_setup();
#endif /* HAVE_CASPER */
init_print(ndo, localnet, netmask, timezone_offset);
#ifndef _WIN32
(void)setsignal(SIGPIPE, cleanup);
(void)setsignal(SIGTERM, cleanup);
(void)setsignal(SIGINT, cleanup);
#endif /* _WIN32 */
#if defined(HAVE_FORK) || defined(HAVE_VFORK)
(void)setsignal(SIGCHLD, child_cleanup);
#endif
/* Cooperate with nohup(1) */
#ifndef _WIN32
if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
(void)setsignal(SIGHUP, oldhandler);
#endif /* _WIN32 */
#ifndef _WIN32
/*
* If a user name was specified with "-Z", attempt to switch to
* that user's UID. This would probably be used with sudo,
* to allow tcpdump to be run in a special restricted
* account (if you just want to allow users to open capture
* devices, and can't just give users that permission,
* you'd make tcpdump set-UID or set-GID).
*
* Tcpdump doesn't necessarily write only to one savefile;
* the general only way to allow a -Z instance to write to
* savefiles as the user under whose UID it's run, rather
* than as the user specified with -Z, would thus be to switch
* to the original user ID before opening a capture file and
* then switch back to the -Z user ID after opening the savefile.
* Switching to the -Z user ID only after opening the first
* savefile doesn't handle the general case.
*/
if (getuid() == 0 || geteuid() == 0) {
#ifdef HAVE_LIBCAP_NG
/* Initialize capng */
capng_clear(CAPNG_SELECT_BOTH);
if (username) {
capng_updatev(
CAPNG_ADD,
CAPNG_PERMITTED | CAPNG_EFFECTIVE,
CAP_SETUID,
CAP_SETGID,
-1);
}
if (chroot_dir) {
capng_update(
CAPNG_ADD,
CAPNG_PERMITTED | CAPNG_EFFECTIVE,
CAP_SYS_CHROOT
);
}
if (WFileName) {
capng_update(
CAPNG_ADD,
CAPNG_PERMITTED | CAPNG_EFFECTIVE,
CAP_DAC_OVERRIDE
);
}
capng_apply(CAPNG_SELECT_BOTH);
#endif /* HAVE_LIBCAP_NG */
if (username || chroot_dir)
droproot(username, chroot_dir);
}
#endif /* _WIN32 */
if (pcap_setfilter(pd, &fcode) < 0)
error("%s", pcap_geterr(pd));
#ifdef HAVE_CAPSICUM
if (RFileName == NULL && VFileName == NULL) {
static const unsigned long cmds[] = { BIOCGSTATS, BIOCROTZBUF };
/*
* The various libpcap devices use a combination of
* read (bpf), ioctl (bpf, netmap), poll (netmap)
* so we add the relevant access rights.
*/
cap_rights_init(&rights, CAP_IOCTL, CAP_READ, CAP_EVENT);
if (cap_rights_limit(pcap_fileno(pd), &rights) < 0 &&
errno != ENOSYS) {
error("unable to limit pcap descriptor");
}
if (cap_ioctls_limit(pcap_fileno(pd), cmds,
sizeof(cmds) / sizeof(cmds[0])) < 0 && errno != ENOSYS) {
error("unable to limit ioctls on pcap descriptor");
}
}
#endif
if (WFileName) {
pcap_dumper_t *p;
/* Do not exceed the default PATH_MAX for files. */
dumpinfo.CurrentFileName = (char *)malloc(PATH_MAX + 1);
if (dumpinfo.CurrentFileName == NULL)
error("malloc of dumpinfo.CurrentFileName");
/* We do not need numbering for dumpfiles if Cflag isn't set. */
if (Cflag != 0)
MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars);
else
MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0);
p = pcap_dump_open(pd, dumpinfo.CurrentFileName);
#ifdef HAVE_LIBCAP_NG
/* Give up CAP_DAC_OVERRIDE capability.
* Only allow it to be restored if the -C or -G flag have been
* set since we may need to create more files later on.
*/
capng_update(
CAPNG_DROP,
(Cflag || Gflag ? 0 : CAPNG_PERMITTED)
| CAPNG_EFFECTIVE,
CAP_DAC_OVERRIDE
);
capng_apply(CAPNG_SELECT_BOTH);
#endif /* HAVE_LIBCAP_NG */
if (p == NULL)
error("%s", pcap_geterr(pd));
#ifdef HAVE_CAPSICUM
set_dumper_capsicum_rights(p);
#endif
if (Cflag != 0 || Gflag != 0) {
#ifdef HAVE_CAPSICUM
dumpinfo.WFileName = strdup(basename(WFileName));
if (dumpinfo.WFileName == NULL) {
error("Unable to allocate memory for file %s",
WFileName);
}
dumpinfo.dirfd = open(dirname(WFileName),
O_DIRECTORY | O_RDONLY);
if (dumpinfo.dirfd < 0) {
error("unable to open directory %s",
dirname(WFileName));
}
cap_rights_init(&rights, CAP_CREATE, CAP_FCNTL,
CAP_FTRUNCATE, CAP_LOOKUP, CAP_SEEK, CAP_WRITE);
if (cap_rights_limit(dumpinfo.dirfd, &rights) < 0 &&
errno != ENOSYS) {
error("unable to limit directory rights");
}
if (cap_fcntls_limit(dumpinfo.dirfd, CAP_FCNTL_GETFL) < 0 &&
errno != ENOSYS) {
error("unable to limit dump descriptor fcntls");
}
#else /* !HAVE_CAPSICUM */
dumpinfo.WFileName = WFileName;
#endif
callback = dump_packet_and_trunc;
dumpinfo.pd = pd;
dumpinfo.p = p;
pcap_userdata = (u_char *)&dumpinfo;
} else {
callback = dump_packet;
pcap_userdata = (u_char *)p;
}
#ifdef HAVE_PCAP_DUMP_FLUSH
if (Uflag)
pcap_dump_flush(p);
#endif
} else {
dlt = pcap_datalink(pd);
ndo->ndo_if_printer = get_if_printer(ndo, dlt);
callback = print_packet;
pcap_userdata = (u_char *)ndo;
}
#ifdef SIGNAL_REQ_INFO
/*
* We can't get statistics when reading from a file rather
* than capturing from a device.
*/
if (RFileName == NULL)
(void)setsignal(SIGNAL_REQ_INFO, requestinfo);
#endif
if (ndo->ndo_vflag > 0 && WFileName) {
/*
* When capturing to a file, "-v" means tcpdump should,
* every 10 seconds, "v"erbosely report the number of
* packets captured.
*/
#ifdef USE_WIN32_MM_TIMER
/* call verbose_stats_dump() each 1000 +/-100msec */
timer_id = timeSetEvent(1000, 100, verbose_stats_dump, 0, TIME_PERIODIC);
setvbuf(stderr, NULL, _IONBF, 0);
#elif defined(HAVE_ALARM)
(void)setsignal(SIGALRM, verbose_stats_dump);
alarm(1);
#endif
}
if (RFileName == NULL) {
/*
* Live capture (if -V was specified, we set RFileName
* to a file from the -V file). Print a message to
* the standard error on UN*X.
*/
if (!ndo->ndo_vflag && !WFileName) {
(void)fprintf(stderr,
"%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
program_name);
} else
(void)fprintf(stderr, "%s: ", program_name);
dlt = pcap_datalink(pd);
dlt_name = pcap_datalink_val_to_name(dlt);
if (dlt_name == NULL) {
(void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
device, dlt, ndo->ndo_snaplen);
} else {
(void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
device, dlt_name,
pcap_datalink_val_to_description(dlt), ndo->ndo_snaplen);
}
(void)fflush(stderr);
}
#ifdef HAVE_CAPSICUM
cansandbox = (VFileName == NULL && zflag == NULL);
#ifdef HAVE_CASPER
cansandbox = (cansandbox && (ndo->ndo_nflag || capdns != NULL));
#else
cansandbox = (cansandbox && ndo->ndo_nflag);
#endif /* HAVE_CASPER */
if (cansandbox && cap_enter() < 0 && errno != ENOSYS)
error("unable to enter the capability mode");
#endif /* HAVE_CAPSICUM */
do {
status = pcap_loop(pd, cnt, callback, pcap_userdata);
if (WFileName == NULL) {
/*
* We're printing packets. Flush the printed output,
* so it doesn't get intermingled with error output.
*/
if (status == -2) {
/*
* We got interrupted, so perhaps we didn't
* manage to finish a line we were printing.
* Print an extra newline, just in case.
*/
putchar('\n');
}
(void)fflush(stdout);
}
if (status == -2) {
/*
* We got interrupted. If we are reading multiple
* files (via -V) set these so that we stop.
*/
VFileName = NULL;
ret = NULL;
}
if (status == -1) {
/*
* Error. Report it.
*/
(void)fprintf(stderr, "%s: pcap_loop: %s\n",
program_name, pcap_geterr(pd));
}
if (RFileName == NULL) {
/*
* We're doing a live capture. Report the capture
* statistics.
*/
info(1);
}
pcap_close(pd);
if (VFileName != NULL) {
ret = get_next_file(VFile, VFileLine);
if (ret) {
int new_dlt;
RFileName = VFileLine;
pd = pcap_open_offline(RFileName, ebuf);
if (pd == NULL)
error("%s", ebuf);
#ifdef HAVE_CAPSICUM
cap_rights_init(&rights, CAP_READ);
if (cap_rights_limit(fileno(pcap_file(pd)),
&rights) < 0 && errno != ENOSYS) {
error("unable to limit pcap descriptor");
}
#endif
new_dlt = pcap_datalink(pd);
if (new_dlt != dlt) {
/*
* The new file has a different
* link-layer header type from the
* previous one.
*/
if (WFileName != NULL) {
/*
* We're writing raw packets
* that match the filter to
* a pcap file. pcap files
* don't support multiple
* different link-layer
* header types, so we fail
* here.
*/
error("%s: new dlt does not match original", RFileName);
}
/*
* We're printing the decoded packets;
* switch to the new DLT.
*
* To do that, we need to change
* the printer, change the DLT name,
* and recompile the filter with
* the new DLT.
*/
dlt = new_dlt;
ndo->ndo_if_printer = get_if_printer(ndo, dlt);
if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
error("%s", pcap_geterr(pd));
}
/*
* Set the filter on the new file.
*/
if (pcap_setfilter(pd, &fcode) < 0)
error("%s", pcap_geterr(pd));
/*
* Report the new file.
*/
dlt_name = pcap_datalink_val_to_name(dlt);
if (dlt_name == NULL) {
fprintf(stderr, "reading from file %s, link-type %u\n",
RFileName, dlt);
} else {
fprintf(stderr,
"reading from file %s, link-type %s (%s)\n",
RFileName, dlt_name,
pcap_datalink_val_to_description(dlt));
}
}
}
}
while (ret != NULL);
free(cmdbuf);
pcap_freecode(&fcode);
exit_tcpdump(status == -1 ? 1 : 0);
}
/* make a clean exit on interrupts */
static RETSIGTYPE
cleanup(int signo _U_)
{
#ifdef USE_WIN32_MM_TIMER
if (timer_id)
timeKillEvent(timer_id);
timer_id = 0;
#elif defined(HAVE_ALARM)
alarm(0);
#endif
#ifdef HAVE_PCAP_BREAKLOOP
/*
* We have "pcap_breakloop()"; use it, so that we do as little
* as possible in the signal handler (it's probably not safe
* to do anything with standard I/O streams in a signal handler -
* the ANSI C standard doesn't say it is).
*/
pcap_breakloop(pd);
#else
/*
* We don't have "pcap_breakloop()"; this isn't safe, but
* it's the best we can do. Print the summary if we're
* not reading from a savefile - i.e., if we're doing a
* live capture - and exit.
*/
if (pd != NULL && pcap_file(pd) == NULL) {
/*
* We got interrupted, so perhaps we didn't
* manage to finish a line we were printing.
* Print an extra newline, just in case.
*/
putchar('\n');
(void)fflush(stdout);
info(1);
}
exit_tcpdump(0);
#endif
}
/*
On windows, we do not use a fork, so we do not care less about
waiting a child processes to die
*/
#if defined(HAVE_FORK) || defined(HAVE_VFORK)
static RETSIGTYPE
child_cleanup(int signo _U_)
{
wait(NULL);
}
#endif /* HAVE_FORK && HAVE_VFORK */
static void
info(register int verbose)
{
struct pcap_stat stats;
/*
* Older versions of libpcap didn't set ps_ifdrop on some
* platforms; initialize it to 0 to handle that.
*/
stats.ps_ifdrop = 0;
if (pcap_stats(pd, &stats) < 0) {
(void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
infoprint = 0;
return;
}
if (!verbose)
fprintf(stderr, "%s: ", program_name);
(void)fprintf(stderr, "%u packet%s captured", packets_captured,
PLURAL_SUFFIX(packets_captured));
if (!verbose)
fputs(", ", stderr);
else
putc('\n', stderr);
(void)fprintf(stderr, "%u packet%s received by filter", stats.ps_recv,
PLURAL_SUFFIX(stats.ps_recv));
if (!verbose)
fputs(", ", stderr);
else
putc('\n', stderr);
(void)fprintf(stderr, "%u packet%s dropped by kernel", stats.ps_drop,
PLURAL_SUFFIX(stats.ps_drop));
if (stats.ps_ifdrop != 0) {
if (!verbose)
fputs(", ", stderr);
else
putc('\n', stderr);
(void)fprintf(stderr, "%u packet%s dropped by interface\n",
stats.ps_ifdrop, PLURAL_SUFFIX(stats.ps_ifdrop));
} else
putc('\n', stderr);
infoprint = 0;
}
#if defined(HAVE_FORK) || defined(HAVE_VFORK)
#ifdef HAVE_FORK
#define fork_subprocess() fork()
#else
#define fork_subprocess() vfork()
#endif
static void
compress_savefile(const char *filename)
{
pid_t child;
child = fork_subprocess();
if (child == -1) {
fprintf(stderr,
"compress_savefile: fork failed: %s\n",
pcap_strerror(errno));
return;
}
if (child != 0) {
/* Parent process. */
return;
}
/*
* Child process.
* Set to lowest priority so that this doesn't disturb the capture.
*/
#ifdef NZERO
setpriority(PRIO_PROCESS, 0, NZERO - 1);
#else
setpriority(PRIO_PROCESS, 0, 19);
#endif
if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
fprintf(stderr,
"compress_savefile: execlp(%s, %s) failed: %s\n",
zflag,
filename,
pcap_strerror(errno));
#ifdef HAVE_FORK
exit(1);
#else
_exit(1);
#endif
}
#else /* HAVE_FORK && HAVE_VFORK */
static void
compress_savefile(const char *filename)
{
fprintf(stderr,
"compress_savefile failed. Functionality not implemented under your system\n");
}
#endif /* HAVE_FORK && HAVE_VFORK */
static void
dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
{
struct dump_info *dump_info;
++packets_captured;
++infodelay;
dump_info = (struct dump_info *)user;
/*
* XXX - this won't force the file to rotate on the specified time
* boundary, but it will rotate on the first packet received after the
* specified Gflag number of seconds. Note: if a Gflag time boundary
* and a Cflag size boundary coincide, the time rotation will occur
* first thereby cancelling the Cflag boundary (since the file should
* be 0).
*/
if (Gflag != 0) {
/* Check if it is time to rotate */
time_t t;
/* Get the current time */
if ((t = time(NULL)) == (time_t)-1) {
error("dump_and_trunc_packet: can't get current_time: %s",
pcap_strerror(errno));
}
/* If the time is greater than the specified window, rotate */
if (t - Gflag_time >= Gflag) {
#ifdef HAVE_CAPSICUM
FILE *fp;
int fd;
#endif
/* Update the Gflag_time */
Gflag_time = t;
/* Update Gflag_count */
Gflag_count++;
/*
* Close the current file and open a new one.
*/
pcap_dump_close(dump_info->p);
/*
* Compress the file we just closed, if the user asked for it
*/
if (zflag != NULL)
compress_savefile(dump_info->CurrentFileName);
/*
* Check to see if we've exceeded the Wflag (when
* not using Cflag).
*/
if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
(void)fprintf(stderr, "Maximum file limit reached: %d\n",
Wflag);
info(1);
exit_tcpdump(0);
/* NOTREACHED */
}
if (dump_info->CurrentFileName != NULL)
free(dump_info->CurrentFileName);
/* Allocate space for max filename + \0. */
dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
if (dump_info->CurrentFileName == NULL)
error("dump_packet_and_trunc: malloc");
/*
* Gflag was set otherwise we wouldn't be here. Reset the count
* so multiple files would end with 1,2,3 in the filename.
* The counting is handled with the -C flow after this.
*/
Cflag_count = 0;
/*
* This is always the first file in the Cflag
* rotation: e.g. 0
* We also don't need numbering if Cflag is not set.
*/
if (Cflag != 0)
MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0,
WflagChars);
else
MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0);
#ifdef HAVE_LIBCAP_NG
capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
capng_apply(CAPNG_SELECT_BOTH);
#endif /* HAVE_LIBCAP_NG */
#ifdef HAVE_CAPSICUM
fd = openat(dump_info->dirfd,
dump_info->CurrentFileName,
O_CREAT | O_WRONLY | O_TRUNC, 0644);
if (fd < 0) {
error("unable to open file %s",
dump_info->CurrentFileName);
}
fp = fdopen(fd, "w");
if (fp == NULL) {
error("unable to fdopen file %s",
dump_info->CurrentFileName);
}
dump_info->p = pcap_dump_fopen(dump_info->pd, fp);
#else /* !HAVE_CAPSICUM */
dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
#endif
#ifdef HAVE_LIBCAP_NG
capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
capng_apply(CAPNG_SELECT_BOTH);
#endif /* HAVE_LIBCAP_NG */
if (dump_info->p == NULL)
error("%s", pcap_geterr(pd));
#ifdef HAVE_CAPSICUM
set_dumper_capsicum_rights(dump_info->p);
#endif
}
}
/*
* XXX - this won't prevent capture files from getting
* larger than Cflag - the last packet written to the
* file could put it over Cflag.
*/
if (Cflag != 0) {
long size = pcap_dump_ftell(dump_info->p);
if (size == -1)
error("ftell fails on output file");
if (size > Cflag) {
#ifdef HAVE_CAPSICUM
FILE *fp;
int fd;
#endif
/*
* Close the current file and open a new one.
*/
pcap_dump_close(dump_info->p);
/*
* Compress the file we just closed, if the user
* asked for it.
*/
if (zflag != NULL)
compress_savefile(dump_info->CurrentFileName);
Cflag_count++;
if (Wflag > 0) {
if (Cflag_count >= Wflag)
Cflag_count = 0;
}
if (dump_info->CurrentFileName != NULL)
free(dump_info->CurrentFileName);
dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
if (dump_info->CurrentFileName == NULL)
error("dump_packet_and_trunc: malloc");
MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars);
#ifdef HAVE_LIBCAP_NG
capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
capng_apply(CAPNG_SELECT_BOTH);
#endif /* HAVE_LIBCAP_NG */
#ifdef HAVE_CAPSICUM
fd = openat(dump_info->dirfd, dump_info->CurrentFileName,
O_CREAT | O_WRONLY | O_TRUNC, 0644);
if (fd < 0) {
error("unable to open file %s",
dump_info->CurrentFileName);
}
fp = fdopen(fd, "w");
if (fp == NULL) {
error("unable to fdopen file %s",
dump_info->CurrentFileName);
}
dump_info->p = pcap_dump_fopen(dump_info->pd, fp);
#else /* !HAVE_CAPSICUM */
dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
#endif
#ifdef HAVE_LIBCAP_NG
capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
capng_apply(CAPNG_SELECT_BOTH);
#endif /* HAVE_LIBCAP_NG */
if (dump_info->p == NULL)
error("%s", pcap_geterr(pd));
#ifdef HAVE_CAPSICUM
set_dumper_capsicum_rights(dump_info->p);
#endif
}
}
pcap_dump((u_char *)dump_info->p, h, sp);
#ifdef HAVE_PCAP_DUMP_FLUSH
if (Uflag)
pcap_dump_flush(dump_info->p);
#endif
--infodelay;
if (infoprint)
info(0);
}
static void
dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
{
++packets_captured;
++infodelay;
pcap_dump(user, h, sp);
#ifdef HAVE_PCAP_DUMP_FLUSH
if (Uflag)
pcap_dump_flush((pcap_dumper_t *)user);
#endif
--infodelay;
if (infoprint)
info(0);
}
static void
print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
{
++packets_captured;
++infodelay;
pretty_print_packet((netdissect_options *)user, h, sp, packets_captured);
--infodelay;
if (infoprint)
info(0);
}
#ifdef _WIN32
/*
* XXX - there should really be libpcap calls to get the version
* number as a string (the string would be generated from #defines
* at run time, so that it's not generated from string constants
* in the library, as, on many UNIX systems, those constants would
* be statically linked into the application executable image, and
* would thus reflect the version of libpcap on the system on
* which the application was *linked*, not the system on which it's
* *running*.
*
* That routine should be documented, unlike the "version[]"
* string, so that UNIX vendors providing their own libpcaps
* don't omit it (as a couple of vendors have...).
*
* Packet.dll should perhaps also export a routine to return the
* version number of the Packet.dll code, to supply the
* "Wpcap_version" information on Windows.
*/
char WDversion[]="current-git.tcpdump.org";
#if !defined(HAVE_GENERATED_VERSION)
char version[]="current-git.tcpdump.org";
#endif
char pcap_version[]="current-git.tcpdump.org";
char Wpcap_version[]="3.1";
#endif
#ifdef SIGNAL_REQ_INFO
RETSIGTYPE requestinfo(int signo _U_)
{
if (infodelay)
++infoprint;
else
info(0);
}
#endif
/*
* Called once each second in verbose mode while dumping to file
*/
#ifdef USE_WIN32_MM_TIMER
void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
{
if (infodelay == 0)
fprintf(stderr, "Got %u\r", packets_captured);
}
#elif defined(HAVE_ALARM)
static void verbose_stats_dump(int sig _U_)
{
if (infodelay == 0)
fprintf(stderr, "Got %u\r", packets_captured);
alarm(1);
}
#endif
USES_APPLE_DEPRECATED_API
static void
print_version(void)
{
extern char version[];
#ifndef HAVE_PCAP_LIB_VERSION
#if defined(_WIN32) || defined(HAVE_PCAP_VERSION)
extern char pcap_version[];
#else /* defined(_WIN32) || defined(HAVE_PCAP_VERSION) */
static char pcap_version[] = "unknown";
#endif /* defined(_WIN32) || defined(HAVE_PCAP_VERSION) */
#endif /* HAVE_PCAP_LIB_VERSION */
const char *smi_version_string;
#ifdef HAVE_PCAP_LIB_VERSION
#ifdef _WIN32
(void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
#else /* _WIN32 */
(void)fprintf(stderr, "%s version %s\n", program_name, version);
#endif /* _WIN32 */
(void)fprintf(stderr, "%s\n",pcap_lib_version());
#else /* HAVE_PCAP_LIB_VERSION */
#ifdef _WIN32
(void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
(void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
#else /* _WIN32 */
(void)fprintf(stderr, "%s version %s\n", program_name, version);
(void)fprintf(stderr, "libpcap version %s\n", pcap_version);
#endif /* _WIN32 */
#endif /* HAVE_PCAP_LIB_VERSION */
#if defined(HAVE_LIBCRYPTO) && defined(SSLEAY_VERSION)
(void)fprintf (stderr, "%s\n", SSLeay_version(SSLEAY_VERSION));
#endif
smi_version_string = nd_smi_version_string();
if (smi_version_string != NULL)
(void)fprintf (stderr, "SMI-library: %s\n", smi_version_string);
#if defined(__SANITIZE_ADDRESS__)
(void)fprintf (stderr, "Compiled with AddressSanitizer/GCC.\n");
#elif defined(__has_feature)
# if __has_feature(address_sanitizer)
(void)fprintf (stderr, "Compiled with AddressSanitizer/CLang.\n");
# endif
#endif /* __SANITIZE_ADDRESS__ or __has_feature */
}
USES_APPLE_RST
static void
print_usage(void)
{
print_version();
(void)fprintf(stderr,
"Usage: %s [-aAbd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqStu" U_FLAG "vxX#]" B_FLAG_USAGE " [ -c count ]\n", program_name);
(void)fprintf(stderr,
"\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
(void)fprintf(stderr,
"\t\t[ -i interface ]" j_FLAG_USAGE " [ -M secret ] [ --number ]\n");
#ifdef HAVE_PCAP_SETDIRECTION
(void)fprintf(stderr,
"\t\t[ -Q in|out|inout ]\n");
#endif
(void)fprintf(stderr,
"\t\t[ -r file ] [ -s snaplen ] ");
#ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
(void)fprintf(stderr, "[ --time-stamp-precision precision ]\n");
(void)fprintf(stderr,
"\t\t");
#endif
#ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
(void)fprintf(stderr, "[ --immediate-mode ] ");
#endif
(void)fprintf(stderr, "[ -T type ] [ --version ] [ -V file ]\n");
(void)fprintf(stderr,
"\t\t[ -w file ] [ -W filecount ] [ -y datalinktype ] [ -z postrotate-command ]\n");
(void)fprintf(stderr,
"\t\t[ -Z user ] [ expression ]\n");
}
/*
* Local Variables:
* c-style: whitesmith
* c-basic-offset: 8
* End:
*/
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