]> The Tcpdump Group git mirrors - tcpdump/blobdiff - tcpdump.c
add support for printing Multi-Link Frame Relay
[tcpdump] / tcpdump.c
index 7f751f0e95d5ca19e342781a5680896c28575e9d..9be35c297807abb7a4bab44b64c050a0111e6130 100644 (file)
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -30,7 +30,7 @@ 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";
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.231 2004-02-24 08:12:18 hannes Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.252 2005-01-27 10:17:59 hannes Exp $ (LBL)";
 #endif
 
 /*
@@ -65,9 +65,13 @@ extern int SIZE_BUF;
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifndef WIN32
 #include <pwd.h>
 #include <grp.h>
+#include <errno.h>
+#endif /* WIN32 */
 
+#include "netdissect.h"
 #include "interface.h"
 #include "addrtoname.h"
 #include "machdep.h"
@@ -75,30 +79,8 @@ extern int SIZE_BUF;
 #include "gmt2local.h"
 #include "pcap-missing.h"
 
-int dflag;                     /* print filter code */
-int eflag;                     /* print ethernet header */
-int fflag;                     /* don't translate "foreign" IP address */
-static int Lflag;              /* list available data link types and exit */
-int nflag;                     /* leave addresses as numbers */
-int Nflag;                     /* remove domains from printed host names */
-static int Oflag = 1;          /* run filter code optimizer */
-static int pflag;              /* don't go promiscuous */
-int qflag;                     /* quick (shorter) output */
-int Rflag = 1;                 /* print sequence # field in AH/ESP*/
-int sflag = 0;                 /* use the libsmi to translate OIDs */
-int Sflag;                     /* print raw TCP sequence numbers */
-int tflag = 1;                 /* print packet arrival time */
-int Uflag = 0;                 /* "unbuffered" output of dump files */
-int uflag = 0;                 /* Print undecoded NFS handles */
-int vflag;                     /* verbose */
-int xflag;                     /* print packet in hex */
-int Xflag;                     /* print packet in ascii as well as hex */
-static off_t Cflag = 0;                /* rotate dump files after this many bytes */
-int Aflag = 0;                  /* print packet only in ascii observing LF, CR, TAB, SPACE */
-static int dlt = -1;           /* if != -1, ask libpcap for the DLT it names */
-static int Cflag_count = 0;    /* Keep track of which file number we're writing */
-static int Wflag = 0;          /* recycle output files after this number of files */
-static int WflagChars = 0;
+netdissect_options Gndo;
+netdissect_options *gndo = &Gndo;
 
 /*
  * Define the maximum number of files for the -C flag, and how many
@@ -108,11 +90,8 @@ static int WflagChars = 0;
 #define MAX_CFLAG      1000000
 #define MAX_CFLAG_CHARS        6
 
-const char *dlt_name = NULL;
-
-char *espsecret = NULL;                /* ESP secret key */
-
-int packettype;
+int dflag;                     /* print filter code */
+int Lflag;                     /* list available data link types and exit */
 
 static int infodelay;
 static int infoprint;
@@ -127,9 +106,12 @@ static void usage(void) __attribute__((noreturn));
 static void show_dlts_and_exit(pcap_t *pd) __attribute__((noreturn));
 
 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
+static void ndo_default_print(netdissect_options *, const u_char *, u_int);
 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 *);
+static void droproot(const char *, const char *);
+static void ndo_error(netdissect_options *ndo, const char *fmt, ...);
+static void ndo_warning(netdissect_options *ndo, const char *fmt, ...);
 
 #ifdef SIGINFO
 RETSIGTYPE requestinfo(int);
@@ -146,9 +128,6 @@ RETSIGTYPE requestinfo(int);
 static void info(int);
 static u_int packets_captured;
 
-/* Length of saved portion of packet. */
-int snaplen = DEFAULT_SNAPLEN;
-
 typedef u_int (*if_printer)(const struct pcap_pkthdr *, const u_char *);
 
 struct printer {
@@ -177,6 +156,9 @@ static struct printer printers[] = {
        { sl_bsdos_if_print,    DLT_SLIP_BSDOS },
 #endif
        { ppp_if_print,         DLT_PPP },
+#ifdef DLT_PPP_WITHDIRECTION
+       { ppp_if_print,         DLT_PPP_WITHDIRECTION },
+#endif
 #ifdef DLT_PPP_BSDOS
        { ppp_bsdos_if_print,   DLT_PPP_BSDOS },
 #endif
@@ -231,6 +213,21 @@ static struct printer printers[] = {
 #endif
 #ifdef DLT_ENC
        { enc_if_print,         DLT_ENC },
+#endif
+#ifdef DLT_SYMANTEC_FIREWALL
+       { symantec_if_print,    DLT_SYMANTEC_FIREWALL },
+#endif
+#ifdef DLT_APPLE_IP_OVER_IEEE1394
+       { ap1394_if_print,      DLT_APPLE_IP_OVER_IEEE1394 },
+#endif
+#ifdef DLT_JUNIPER_ATM1
+       { juniper_atm1_print,   DLT_JUNIPER_ATM1 },
+#endif
+#ifdef DLT_JUNIPER_ATM2
+       { juniper_atm2_print,   DLT_JUNIPER_ATM2 },
+#endif
+#ifdef DLT_JUNIPER_MLFR
+       { juniper_mlfr_print,   DLT_JUNIPER_MLFR },
 #endif
        { NULL,                 0 },
 };
@@ -312,6 +309,12 @@ show_dlts_and_exit(pcap_t *pd)
 #define B_FLAG_USAGE
 #endif /* WIN32 */
 
+#ifdef HAVE_PCAP_FINDALLDEVS
+#ifndef HAVE_PCAP_IF_T
+#undef HAVE_PCAP_FINDALLDEVS
+#endif
+#endif
+
 #ifdef HAVE_PCAP_FINDALLDEVS
 #define D_FLAG "D"
 #else
@@ -324,26 +327,44 @@ show_dlts_and_exit(pcap_t *pd)
 #define U_FLAG
 #endif
 
-/* Drop root privileges */
+#ifndef WIN32
+/* Drop root privileges and chroot if necessary */
 static void
-droproot(const char *username)
+droproot(const char *username, const char *chroot_dir)
 {
        struct passwd *pw = NULL;
 
+       if (chroot_dir && !username) {
+               fprintf(stderr, "tcpdump: Chroot without dropping root is insecure\n");
+               exit(1);
+       }
+       
        pw = getpwnam(username);
        if (pw) {
-               if (initgroups(pw->pw_name, 0) != 0 || setgid(pw->pw_gid) != 0 ||
-                                setuid(pw->pw_uid) != 0) {
-                       fprintf(stderr, "Couldn't change to '%.32s' uid=%d gid=%d\n", username, 
-                                                       pw->pw_uid, pw->pw_gid);
+               if (chroot_dir) {
+                       if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
+                               fprintf(stderr, "tcpdump: Couldn't chroot/chdir to '%.64s': %s\n",
+                                   chroot_dir, pcap_strerror(errno));
+                               exit(1);
+                       }
+               }
+               if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
+                   setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) {
+                       fprintf(stderr, "tcpdump: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
+                           username, 
+                           (unsigned long)pw->pw_uid,
+                           (unsigned long)pw->pw_gid,
+                           pcap_strerror(errno));
                        exit(1);
                }
        }
        else {
-               fprintf(stderr, "Couldn't find user '%.32s'\n", username);
+               fprintf(stderr, "tcpdump: Couldn't find user '%.32s'\n",
+                   username);
                exit(1);
        }
 }
+#endif /* WIN32 */
 
 static int
 getWflagChars(int x)
@@ -369,6 +390,20 @@ MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
                sprintf(buffer, "%s%0*d", orig_name, max_chars, cnt);
 }
 
+static int tcpdump_printf(netdissect_options *ndo _U_,
+                         const char *fmt, ...)
+{
+  
+  va_list args;
+  int ret;
+
+  va_start(args, fmt);
+  ret=vfprintf(stdout, fmt, args);
+  va_end(args);
+
+  return ret;
+}
+
 int
 main(int argc, char **argv)
 {
@@ -386,6 +421,7 @@ main(int argc, char **argv)
        u_char *pcap_userdata;
        char ebuf[PCAP_ERRBUF_SIZE];
        char *username = NULL;
+       char *chroot_dir = NULL;
 #ifdef HAVE_PCAP_FINDALLDEVS
        pcap_if_t *devpointer;
        int devnum;
@@ -396,6 +432,15 @@ main(int argc, char **argv)
        if(wsockinit() != 0) return 1;
 #endif /* WIN32 */
 
+        gndo->ndo_Oflag=1;
+       gndo->ndo_Rflag=1;
+       gndo->ndo_dlt=-1;
+       gndo->ndo_default_print=ndo_default_print;
+       gndo->ndo_printf=tcpdump_printf;
+       gndo->ndo_error=ndo_error;
+       gndo->ndo_warning=ndo_warning;
+       gndo->ndo_snaplen = DEFAULT_SNAPLEN;
+  
        cnt = -1;
        device = NULL;
        infile = NULL;
@@ -415,7 +460,7 @@ main(int argc, char **argv)
 
        opterr = 0;
        while (
-           (op = getopt(argc, argv, "aA" B_FLAG "c:C:d" D_FLAG "eE:fF:i:lLm:nNOpqr:Rs:StT:u" U_FLAG "vw:W:xXy:YZ:")) != -1)
+           (op = getopt(argc, argv, "aA" B_FLAG "c:C:d" D_FLAG "eE:fF:i:lLm:M:nNOpqr:Rs:StT:u" U_FLAG "vw:W:xXy:YZ:")) != -1)
                switch (op) {
 
                case 'a':
@@ -480,7 +525,7 @@ main(int argc, char **argv)
 #ifndef HAVE_LIBCRYPTO
                        warning("crypto code not compiled in");
 #endif
-                       espsecret = optarg;
+                       gndo->ndo_espsecret = optarg;
                        break;
 
                case 'f':
@@ -568,6 +613,14 @@ main(int argc, char **argv)
 #endif
                        break;
 
+               case 'M':
+                       /* TCP-MD5 shared secret */
+#ifndef HAVE_LIBCRYPTO
+                       warning("crypto code not compiled in");
+#endif
+                       tcpmd5secret = optarg;
+                       break;
+
                case 'O':
                        Oflag = 0;
                        break;
@@ -605,7 +658,7 @@ main(int argc, char **argv)
                        break;
 
                case 't':
-                       --tflag;
+                       ++tflag;
                        break;
 
                case 'T':
@@ -661,15 +714,15 @@ main(int argc, char **argv)
                        break;
 
                case 'X':
-                       ++xflag;
                        ++Xflag;
                        break;
 
                case 'y':
-                       dlt_name = optarg;
-                       dlt = pcap_datalink_name_to_val(dlt_name);
-                       if (dlt < 0)
-                               error("invalid data link type %s", dlt_name);
+                       gndo->ndo_dltname = optarg;
+                       gndo->ndo_dlt =
+                         pcap_datalink_name_to_val(gndo->ndo_dltname);
+                       if (gndo->ndo_dlt < 0)
+                               error("invalid data link type %s", gndo->ndo_dltname);
                        break;
 
 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
@@ -701,8 +754,31 @@ main(int argc, char **argv)
                        /* NOTREACHED */
                }
 
-       if (tflag > 0)
+       switch (tflag) {
+
+       case 0: /* Default */
+       case 4: /* Default + Date*/
                thiszone = gmt2local(0);
+               break;
+
+       case 1: /* No time stamp */
+       case 2: /* Unix timeval style */
+       case 3: /* Microseconds since previous packet */
+               break;
+
+       default: /* Not supported */
+               error("only -t, -tt, -ttt, and -tttt are supported");
+               break;
+       }
+
+#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 */
@@ -755,11 +831,8 @@ main(int argc, char **argv)
                                error("%s", ebuf);
                }
 #ifdef WIN32
-               if(IsTextUnicode(device,  
-                       wcslen((short*)device),                // Device always ends with a double \0, so this way to determine its 
-                                                                                                       // length should be always valid
-                       NULL))
-               {
+               if(strlen(device) == 1) //we assume that an ASCII string is always longer than 1 char
+               {                                               //a Unicode string has a \0 as second byte (so strlen() is 1)
                        fprintf(stderr, "%s: listening on %ws\n", program_name, device);
                }
                else
@@ -790,9 +863,9 @@ main(int argc, char **argv)
 #endif /* WIN32 */
                if (Lflag)
                        show_dlts_and_exit(pd);
-               if (dlt >= 0) {
+               if (gndo->ndo_dlt >= 0) {
 #ifdef HAVE_PCAP_SET_DATALINK
-                       if (pcap_set_datalink(pd, dlt) < 0)
+                       if (pcap_set_datalink(pd, gndo->ndo_dlt) < 0)
                                error("%s", pcap_geterr(pd));
 #else
                        /*
@@ -800,13 +873,13 @@ main(int argc, char **argv)
                         * data link type, so we only let them
                         * set it to what it already is.
                         */
-                       if (dlt != pcap_datalink(pd)) {
+                       if (gndo->ndo_dlt != pcap_datalink(pd)) {
                                error("%s is not one of the DLTs supported by this device\n",
-                                   dlt_name);
+                                     gndo->ndo_dltname);
                        }
 #endif
                        (void)fprintf(stderr, "%s: data link type %s\n",
-                                     program_name, dlt_name);
+                                     program_name, gndo->ndo_dltname);
                        (void)fflush(stderr);
                }
                i = pcap_snapshot(pd);
@@ -871,9 +944,10 @@ main(int argc, char **argv)
                type = pcap_datalink(pd);
                printinfo.printer = lookup_printer(type);
                if (printinfo.printer == NULL) {
-                       dlt_name = pcap_datalink_val_to_name(type);
-                       if (dlt_name != NULL)
-                               error("unsupported data link type %s", dlt_name);
+                       gndo->ndo_dltname = pcap_datalink_val_to_name(type);
+                       if (gndo->ndo_dltname != NULL)
+                               error("unsupported data link type %s",
+                                     gndo->ndo_dltname);
                        else
                                error("unsupported data link type %d", type);
                }
@@ -885,8 +959,9 @@ main(int argc, char **argv)
         * We cannot do this earlier, because we want to be able to open
         * the file (if done) for writing before giving up permissions.
         */
-       if (username) {
-               droproot(username);
+       if (getuid() == 0 || geteuid() == 0) {
+               if (username || chroot_dir)
+                       droproot(username, chroot_dir);
        }
 #endif /* WIN32 */
 #ifdef SIGINFO
@@ -1133,7 +1208,26 @@ print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
                        /*
                         * Include the link-layer header.
                         */
-                       default_print(sp, h->caplen);
+                       hex_print("\n\t", sp, h->caplen);
+               } else {
+                       /*
+                        * Don't include the link-layer header - and if
+                        * we have nothing past the link-layer header,
+                        * print nothing.
+                        */
+                       if (h->caplen > hdrlen)
+                               hex_print("\n\t", sp + hdrlen,
+                                   h->caplen - hdrlen);
+               }
+       } else if (Xflag) {
+               /*
+                * Print the raw packet data.
+                */
+               if (Xflag > 1) {
+                       /*
+                        * Include the link-layer header.
+                        */
+                       ascii_print("\n\t", sp, h->caplen);
                } else {
                        /*
                         * Don't include the link-layer header - and if
@@ -1141,7 +1235,7 @@ print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
                         * print nothing.
                         */
                        if (h->caplen > hdrlen)
-                               default_print(sp + hdrlen,
+                               ascii_print("\n\t", sp + hdrlen,
                                    h->caplen - hdrlen);
                }
        }
@@ -1177,16 +1271,22 @@ print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
        char version[]="current-cvs.tcpdump.org";
 #endif
        char pcap_version[]="current-cvs.tcpdump.org";
-       char Wpcap_version[]="3.0 alpha";
+       char Wpcap_version[]="3.1";
 #endif
 
 /*
  * By default, print the specified data out in hex.
  */
+static void
+ndo_default_print(netdissect_options *ndo _U_, const u_char *bp, u_int length)
+{
+       ascii_print("\n\t", bp, length); /* pass on lf and identation string */
+}
+
 void
-default_print(register const u_char *bp, register u_int length)
+default_print(const u_char *bp, u_int length)
 {
-    ascii_print("\n\t", bp, length); /* pass on lf and identation string */
+       ndo_default_print(gndo, bp, length);
 }
 
 #ifdef SIGINFO
@@ -1235,8 +1335,12 @@ usage(void)
 #endif /* HAVE_PCAP_LIB_VERSION */
 
 #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);
-       (void)fprintf(stderr, "%s\n", pcap_lib_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);
@@ -1249,12 +1353,51 @@ usage(void)
        (void)fprintf(stderr,
 "Usage: %s [-aAd" D_FLAG "eflLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [-c count] [ -C file_size ]\n", program_name);
        (void)fprintf(stderr,
-"\t\t[ -E algo:secret ] [ -F file ] [ -i interface ] [ -r file ]\n");
+"\t\t[ -E algo:secret ] [ -F file ] [ -i interface ] [ -M secret ]\n");
        (void)fprintf(stderr,
-"\t\t[ -s snaplen ] [ -T type ] [ -w file ] [ -W filecount ]\n");
+"\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ -w file ]\n");
        (void)fprintf(stderr,
-"\t\t[ -y datalinktype ] [ -Z user ]\n");
+"\t\t[ -W filecount ] [ -y datalinktype ] [ -Z user ]\n");
        (void)fprintf(stderr,
 "\t\t[ expression ]\n");
        exit(1);
 }
+
+
+
+/* VARARGS */
+static void
+ndo_error(netdissect_options *ndo _U_, 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(1);
+       /* NOTREACHED */
+}
+
+/* VARARGS */
+static void
+ndo_warning(netdissect_options *ndo _U_, 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);
+       }
+}
+