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