]> The Tcpdump Group git mirrors - tcpdump/blobdiff - tcpdump.c
Hoist a bunch of stuff that should be done by all if_print routines into
[tcpdump] / tcpdump.c
index 4fd5c6a791f834c62f0d49d1cc399e6fe2d2c97a..a4dde2f34ec35c027b31c73cd8dd7e24d7598172 100644 (file)
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -30,7 +30,7 @@ static const char copyright[] =
     "@(#) 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[] =
-    "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.191 2002-12-19 05:44:47 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.193 2002-12-19 09:39:17 guy Exp $ (LBL)";
 #endif
 
 /*
@@ -62,17 +62,18 @@ extern int SIZE_BUF;
 #include <stdlib.h>
 #include <string.h>
 
-
 #include "interface.h"
 #include "addrtoname.h"
 #include "machdep.h"
 #include "setsignal.h"
 #include "gmt2local.h"
+#include "pcap-missing.h"
 
 int aflag;                     /* translate network and broadcast addresses */
 int dflag;                     /* print filter code */
 int eflag;                     /* print ethernet header */
 int fflag;                     /* don't translate "foreign" IP address */
+int Lflag;                     /* list available data link types and exit */
 int nflag;                     /* leave addresses as numbers */
 int Nflag;                     /* remove domains from printed host names */
 int Oflag = 1;                 /* run filter code optimizer */
@@ -88,13 +89,16 @@ int xflag;                  /* print packet in hex */
 int Xflag;                     /* print packet in ascii as well as hex */
 off_t Cflag = 0;                /* rotate dump files after this many bytes */
 int Aflag = 0;                  /* print packet only in ascii observing LF, CR, TAB, SPACE */
+int dlt = -1;          /* if != -1, ask libpcap for the DLT it names */
+
+const char *dlt_name = NULL;
 
 char *espsecret = NULL;                /* ESP secret key */
 
 int packettype;
 
-int infodelay;
-int infoprint;
+static int infodelay;
+static int infoprint;
 
 char *program_name;
 
@@ -103,7 +107,9 @@ int32_t thiszone;           /* seconds offset from gmt to local time */
 /* Forwards */
 static RETSIGTYPE cleanup(int);
 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 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 *);
 
@@ -111,11 +117,15 @@ static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 RETSIGTYPE requestinfo(int);
 #endif
 
+static void info(int);
+
 /* Length of saved portion of packet. */
 int snaplen = DEFAULT_SNAPLEN;
 
+typedef u_int (*if_printer)(const struct pcap_pkthdr *, const u_char *);
+
 struct printer {
-       pcap_handler f;
+       if_printer f;
        int type;
 };
 
@@ -188,7 +198,7 @@ static struct printer printers[] = {
        { NULL,                 0 },
 };
 
-static pcap_handler
+static if_printer
 lookup_printer(int type)
 {
        struct printer *p;
@@ -197,7 +207,7 @@ lookup_printer(int type)
                if (type == p->type)
                        return p->f;
 
-       error("unknown data link type %d", type);
+       return NULL;
        /* NOTREACHED */
 }
 
@@ -207,23 +217,64 @@ extern int optind;
 extern int opterr;
 extern char *optarg;
 
+struct print_info {
+       if_printer printer;
+};
+
 struct dump_info {
        char    *WFileName;
        pcap_t  *pd;
        pcap_dumper_t *p;
 };
 
+static void
+show_dlts_and_exit(pcap_t *pd)
+{
+       int n_dlts;
+       int *dlts = 0;
+       const char *dlt_name;
+
+       n_dlts = pcap_list_datalinks(pd, &dlts);
+       if (n_dlts < 0)
+               error("%s", pcap_geterr(pd));
+       else if (n_dlts == 0 || !dlts)
+               error("No data link types.");
+
+       (void) fprintf(stderr, "Data link types (use option -y to set):\n");
+
+       while (--n_dlts >= 0) {
+               dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
+               if (dlt_name != NULL) {
+                       (void) fprintf(stderr, "  %s", dlt_name);
+
+                       /*
+                        * OK, does tcpdump handle that type?
+                        */
+                       if (lookup_printer(dlts[n_dlts]) == NULL)
+                               (void) fprintf(stderr, " (not supported)");
+                       putchar('\n');
+               } else {
+                       (void) fprintf(stderr, "  DLT %d (not supported)\n",
+                           dlts[n_dlts]);
+               }
+       }
+       free(dlts);
+       exit(0);
+}
+
 int
 main(int argc, char **argv)
 {
        register int cnt, op, i;
        bpf_u_int32 localnet, netmask;
        register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName;
-       pcap_handler printer;
+       pcap_handler callback;
+       int type;
        struct bpf_program fcode;
 #ifndef WIN32
        RETSIGTYPE (*oldhandler)(int);
 #endif
+       struct print_info printinfo;
        struct dump_info dumpinfo;
        u_char *pcap_userdata;
        char ebuf[PCAP_ERRBUF_SIZE];
@@ -263,12 +314,12 @@ main(int argc, char **argv)
        opterr = 0;
        while (
 #ifdef WIN32
-           (op = getopt(argc, argv, "aAB:c:C:dDeE:fF:i:lm:nNOpqr:Rs:StT:uvw:xXY")) != -1)
+           (op = getopt(argc, argv, "aAB:c:C:dDeE:fF:i:lLm:nNOpqr:Rs:StT:uvw:xXy:Y")) != -1)
 #else /* WIN32 */
 #ifdef HAVE_PCAP_FINDALLDEVS
-           (op = getopt(argc, argv, "aAc:C:dDeE:fF:i:lm:nNOpqr:Rs:StT:uvw:xXY")) != -1)
+           (op = getopt(argc, argv, "aAc:C:dDeE:fF:i:lLm:nNOpqr:Rs:StT:uvw:xXy:Y")) != -1)
 #else /* HAVE_PCAP_FINDALLDEVS */
-           (op = getopt(argc, argv, "aAc:C:deE:fF:i:lm:nNOpqr:Rs:StT:uvw:xXY")) != -1)
+           (op = getopt(argc, argv, "aAc:C:deE:fF:i:lLm:nNOpqr:Rs:StT:uvw:xXy:Y")) != -1)
 #endif /* HAVE_PCAP_FINDALLDEVS */
 #endif /* WIN32 */
                switch (op) {
@@ -277,11 +328,11 @@ main(int argc, char **argv)
                        ++aflag;
                        break;
 
-               case 'A':
-                       ++xflag;
-                       ++Xflag;
-                       ++Aflag;
-                       break;
+               case 'A':
+                       ++xflag;
+                       ++Xflag;
+                       ++Aflag;
+                       break;
 
 #ifdef WIN32
                case 'B':
@@ -323,6 +374,10 @@ main(int argc, char **argv)
                        return 0;
 #endif /* HAVE_PCAP_FINDALLDEVS */
 
+               case 'L':
+                       Lflag++;
+                       break;
+
                case 'e':
                        ++eflag;
                        break;
@@ -485,6 +540,13 @@ main(int argc, char **argv)
                        ++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);
+                       break;
+
 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
                case 'Y':
                        {
@@ -548,6 +610,27 @@ main(int argc, char **argv)
                                error("%s", pcap_geterr(pd));
                        }
 #endif /* WIN32 */
+               if (Lflag)
+                       show_dlts_and_exit(pd);
+               if (dlt >= 0) {
+#ifdef HAVE_PCAP_SET_DATALINK
+                       if (pcap_set_datalink(pd, 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 (dlt != pcap_datalink(pd)) {
+                               error("%s is not one of the DLTs supported by this device\n",
+                                   dlt_name);
+                       }
+#endif
+                       (void)fprintf(stderr, "%s: data link type %s\n",
+                                     program_name, dlt_name);
+                       (void)fflush(stderr);
+               }
                i = pcap_snapshot(pd);
                if (snaplen < i) {
                        warning("snaplen raised from %d to %d", snaplen, i);
@@ -594,18 +677,27 @@ main(int argc, char **argv)
                if (p == NULL)
                        error("%s", pcap_geterr(pd));
                if (Cflag != 0) {
-                       printer = dump_packet_and_trunc;
+                       callback = dump_packet_and_trunc;
                        dumpinfo.WFileName = WFileName;
                        dumpinfo.pd = pd;
                        dumpinfo.p = p;
                        pcap_userdata = (u_char *)&dumpinfo;
                } else {
-                       printer = dump_packet;
+                       callback = dump_packet;
                        pcap_userdata = (u_char *)p;
                }
        } else {
-               printer = lookup_printer(pcap_datalink(pd));
-               pcap_userdata = 0;
+               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);
+                       else
+                               error("unsupported data link type %d", type);
+               }
+               callback = print_packet;
+               pcap_userdata = (u_char *)&printinfo;
        }
 #ifdef SIGINFO
        (void)setsignal(SIGINFO, requestinfo);
@@ -617,7 +709,7 @@ main(int argc, char **argv)
                (void)fflush(stderr);
        }
 #endif /* WIN32 */
-       if (pcap_loop(pd, cnt, printer, pcap_userdata) < 0) {
+       if (pcap_loop(pd, cnt, callback, pcap_userdata) < 0) {
                (void)fprintf(stderr, "%s: pcap_loop: %s\n",
                    program_name, pcap_geterr(pd));
                cleanup(0);
@@ -645,7 +737,7 @@ cleanup(int signo)
                exit(0);
 }
 
-void
+static void
 info(register int verbose)
 {
        struct pcap_stat stat;
@@ -743,6 +835,53 @@ dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
                info(0);
 }
 
+static void
+print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
+{
+       struct print_info *print_info;
+       u_int hdrlen;
+
+       ++infodelay;
+       ts_print(&h->ts);
+
+       print_info = (struct print_info *)user;
+
+       /*
+        * Some printers want to check that they're not walking off the
+        * end of the packet.
+        * Rather than pass it all the way down, we set this global.
+        */
+       snapend = sp + h->caplen;
+
+       hdrlen = (*print_info->printer)(h, sp);
+       if (xflag) {
+               /*
+                * Print the raw packet data.
+                */
+               if (xflag > 1) {
+                       /*
+                        * Include the link-layer header.
+                        */
+                       default_print_unaligned(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)
+                               default_print_unaligned(sp + hdrlen,
+                                   h->caplen - hdrlen);
+               }
+       }
+
+       putchar('\n');
+
+       --infodelay;
+       if (infoprint)
+               info(0);
+}
+
 /* Like default_print() but data need not be aligned */
 void
 default_print_unaligned(register const u_char *cp, register u_int length)
@@ -803,31 +942,6 @@ default_print(register const u_char *bp, register u_int length)
        default_print_unaligned(bp, length);
 }
 
-/*
- * By default, print the packet out in hex; if eflag is set, print
- * everything, otherwise print everything except for the link-layer
- * header.
- */
-void
-default_print_packet(register const u_char *bp, register u_int length,
-    u_int hdr_length)
-{
-       if (xflag > 1) {
-               /*
-                * Include the link-layer header.
-                */
-               default_print_unaligned(bp, length);
-       } else {
-               /*
-                * Don't include the link-layer header - and if we have
-                * nothing past the link-layer header, print nothing.
-                */
-               if (length > hdr_length)
-                       default_print_unaligned(bp + hdr_length,
-                           length - hdr_length);
-       }
-}
-
 #ifdef SIGINFO
 RETSIGTYPE requestinfo(int signo _U_)
 {
@@ -857,17 +971,19 @@ usage(void)
 #endif /* WIN32 */
        (void)fprintf(stderr,
 #ifdef WIN32
-"Usage: %s [-aAdDeflnNOpqRStuvxX] [-B size] [-c count] [ -C file_size ]\n", program_name);
+"Usage: %s [-aAdDeflLnNOpqRStuvxX] [-B size] [-c count] [ -C file_size ]\n", program_name);
 #else /* WIN32 */
 #ifdef HAVE_PCAP_FINDALLDEVS
-"Usage: %s [-aAdDeflnNOpqRStuvxX] [-c count] [ -C file_size ]\n", program_name);
+"Usage: %s [-aAdDeflLnNOpqRStuvxX] [-c count] [ -C file_size ]\n", program_name);
 #else /* HAVE_PCAP_FINDALLDEVS */
-"Usage: %s [-aAdeflnNOpqRStuvxX] [-c count] [ -C file_size ]\n", program_name);
+"Usage: %s [-aAdeflLnNOpqRStuvxX] [-c count] [ -C file_size ]\n", program_name);
 #endif /* HAVE_PCAP_FINDALLDEVS */
 #endif /* WIN32 */
        (void)fprintf(stderr,
-"\t\t[ -F file ] [ -i interface ] [ -r file ] [ -s snaplen ]\n");
+"\t\t[ -E algo:secret ] [ -F file ] [ -i interface ] [ -r file ]\n");
+       (void)fprintf(stderr,
+"\t\t[ -s snaplen ] [ -T type ] [ -w file ] [ -y datalinktype ]\n");
        (void)fprintf(stderr,
-"\t\t[ -T type ] [ -w file ] [ -E algo:secret ] [ expression ]\n");
+"\t\t[ expression ]\n");
        exit(1);
 }