The Tcpdump Group git mirrors - tcpdump/blob - print-syslog.c

   1 /*
   2  * Copyright (c) 1998-2004  Hannes Gredler <hannes@gredler.at>
   3  *      The TCPDUMP project
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code
   7  * distributions retain the above copyright notice and this paragraph
   8  * in its entirety, and (2) distributions including binary code include
   9  * the above copyright notice and this paragraph in its entirety in
  10  * the documentation or other materials provided with the distribution.
  11  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
  12  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
  13  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  14  * FOR A PARTICULAR PURPOSE.
  15  */
  16
  17 /* \summary: Syslog protocol printer */
  18 /* specification: RFC 3164 (not RFC 5424) */
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include <config.h>
  22 #endif
  23
  24 #include "netdissect-stdinc.h"
  25
  26 #include "netdissect.h"
  27 #include "extract.h"
  28
  29
  30 /*
  31  * tokenlists and #defines taken from Ethereal - Network traffic analyzer
  32  * by Gerald Combs <gerald@ethereal.com>
  33  */
  34
  35 #define SYSLOG_SEVERITY_MASK 0x0007  /* 0000 0000 0000 0111 */
  36 #define SYSLOG_FACILITY_MASK 0x03f8  /* 0000 0011 1111 1000 */
  37 #define SYSLOG_MAX_DIGITS 3 /* The maximum number of priority digits to read in. */
  38
  39 static const struct tok syslog_severity_values[] = {
  40   { 0,      "emergency" },
  41   { 1,      "alert" },
  42   { 2,      "critical" },
  43   { 3,      "error" },
  44   { 4,      "warning" },
  45   { 5,      "notice" },
  46   { 6,      "info" },
  47   { 7,      "debug" },
  48   { 0, NULL },
  49 };
  50
  51 static const struct tok syslog_facility_values[] = {
  52   { 0,     "kernel" },
  53   { 1,     "user" },
  54   { 2,     "mail" },
  55   { 3,     "daemon" },
  56   { 4,     "auth" },
  57   { 5,     "syslog" },
  58   { 6,     "lpr" },
  59   { 7,     "news" },
  60   { 8,     "uucp" },
  61   { 9,     "cron" },
  62   { 10,    "authpriv" },
  63   { 11,    "ftp" },
  64   { 12,    "ntp" },
  65   { 13,    "security" },
  66   { 14,    "console" },
  67   { 15,    "cron" },
  68   { 16,    "local0" },
  69   { 17,    "local1" },
  70   { 18,    "local2" },
  71   { 19,    "local3" },
  72   { 20,    "local4" },
  73   { 21,    "local5" },
  74   { 22,    "local6" },
  75   { 23,    "local7" },
  76   { 0, NULL },
  77 };
  78
  79 void
  80 syslog_print(netdissect_options *ndo,
  81              const u_char *pptr, u_int len)
  82 {
  83     uint16_t msg_off = 0;
  84     uint16_t pri = 0;
  85     uint16_t facility,severity;
  86
  87     ndo->ndo_protocol = "syslog";
  88     /* extract decimal figures that are
  89      * encapsulated within < > tags
  90      * based on this decimal figure extract the
  91      * severity and facility values
  92      */
  93
  94     if (GET_U_1(pptr) != '<')
  95         goto invalid;
  96     msg_off++;
  97
  98     while (msg_off <= SYSLOG_MAX_DIGITS &&
  99            GET_U_1(pptr + msg_off) >= '0' &&
 100            GET_U_1(pptr + msg_off) <= '9') {
 101         pri = pri * 10 + (GET_U_1(pptr + msg_off) - '0');
 102         msg_off++;
 103     }
 104
 105     if (GET_U_1(pptr + msg_off) != '>')
 106         goto invalid;
 107     msg_off++;
 108
 109     facility = (pri & SYSLOG_FACILITY_MASK) >> 3;
 110     severity = pri & SYSLOG_SEVERITY_MASK;
 111
 112     if (ndo->ndo_vflag < 1 )
 113     {
 114         ND_PRINT("SYSLOG %s.%s, length: %u",
 115                tok2str(syslog_facility_values, "unknown (%u)", facility),
 116                tok2str(syslog_severity_values, "unknown (%u)", severity),
 117                len);
 118         return;
 119     }
 120
 121     ND_PRINT("SYSLOG, length: %u\n\tFacility %s (%u), Severity %s (%u)\n\tMsg: ",
 122            len,
 123            tok2str(syslog_facility_values, "unknown (%u)", facility),
 124            facility,
 125            tok2str(syslog_severity_values, "unknown (%u)", severity),
 126            severity);
 127
 128     /* print the syslog text in verbose mode */
 129     /*
 130      * RFC 3164 Section 4.1.3: "There is no ending delimiter to this part.
 131      * The MSG part of the syslog packet MUST contain visible (printing)
 132      * characters."
 133      *
 134      * RFC 5424 Section 8.2: "This document does not impose any mandatory
 135      * restrictions on the MSG or PARAM-VALUE content.  As such, they MAY
 136      * contain control characters, including the NUL character."
 137      *
 138      * Hence, to aid in protocol debugging, print the full MSG without
 139      * beautification to make it clear what was transmitted on the wire.
 140      */
 141     if (len > msg_off)
 142         nd_printjn(ndo, pptr + msg_off, len - msg_off);
 143
 144     if (ndo->ndo_vflag > 1)
 145         print_unknown_data(ndo, pptr, "\n\t", len);
 146     return;
 147
 148 invalid:
 149     nd_print_invalid(ndo);
 150 }