print-syslog.c revision 1.8 
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#include <sys/cdefs.h>
18#ifndef lint
19__RCSID("$NetBSD: print-syslog.c,v 1.8 2017/09/08 14:01:13 christos Exp $");
20#endif
21
22/* \summary: Syslog protocol printer */
23
24#ifdef HAVE_CONFIG_H
25#include "config.h"
26#endif
27
28#include <netdissect-stdinc.h>
29
30#include "netdissect.h"
31#include "extract.h"
32
33static const char tstr[] = "[|syslog]";
34
35/*
36 * tokenlists and #defines taken from Ethereal - Network traffic analyzer
37 * by Gerald Combs <gerald@ethereal.com>
38 */
39
40#define SYSLOG_SEVERITY_MASK 0x0007  /* 0000 0000 0000 0111 */
41#define SYSLOG_FACILITY_MASK 0x03f8  /* 0000 0011 1111 1000 */
42#define SYSLOG_MAX_DIGITS 3 /* The maximum number if priority digits to read in. */
43
44static const struct tok syslog_severity_values[] = {
45  { 0,      "emergency" },
46  { 1,      "alert" },
47  { 2,      "critical" },
48  { 3,      "error" },
49  { 4,      "warning" },
50  { 5,      "notice" },
51  { 6,      "info" },
52  { 7,      "debug" },
53  { 0, NULL },
54};
55
56static const struct tok syslog_facility_values[] = {
57  { 0,     "kernel" },
58  { 1,     "user" },
59  { 2,     "mail" },
60  { 3,     "daemon" },
61  { 4,     "auth" },
62  { 5,     "syslog" },
63  { 6,     "lpr" },
64  { 7,     "news" },
65  { 8,     "uucp" },
66  { 9,     "cron" },
67  { 10,    "authpriv" },
68  { 11,    "ftp" },
69  { 12,    "ntp" },
70  { 13,    "security" },
71  { 14,    "console" },
72  { 15,    "cron" },
73  { 16,    "local0" },
74  { 17,    "local1" },
75  { 18,    "local2" },
76  { 19,    "local3" },
77  { 20,    "local4" },
78  { 21,    "local5" },
79  { 22,    "local6" },
80  { 23,    "local7" },
81  { 0, NULL },
82};
83
84void
85syslog_print(netdissect_options *ndo,
86             register const u_char *pptr, register u_int len)
87{
88    uint16_t msg_off = 0;
89    uint16_t pri = 0;
90    uint16_t facility,severity;
91
92    /* extract decimal figures that are
93     * encapsulated within < > tags
94     * based on this decimal figure extract the
95     * severity and facility values
96     */
97
98    ND_TCHECK2(*pptr, 1);
99    if (*(pptr+msg_off) == '<') {
100        msg_off++;
101        ND_TCHECK2(*(pptr + msg_off), 1);
102        while ( *(pptr+msg_off) >= '0' &&
103                *(pptr+msg_off) <= '9' &&
104                msg_off <= SYSLOG_MAX_DIGITS) {
105            pri = pri * 10 + (*(pptr+msg_off) - '0');
106            msg_off++;
107            ND_TCHECK2(*(pptr + msg_off), 1);
108        }
109        if (*(pptr+msg_off) != '>') {
110            ND_PRINT((ndo, "%s", tstr));
111            return;
112        }
113        msg_off++;
114    } else {
115        ND_PRINT((ndo, "%s", tstr));
116        return;
117    }
118
119    facility = (pri & SYSLOG_FACILITY_MASK) >> 3;
120    severity = pri & SYSLOG_SEVERITY_MASK;
121
122    if (ndo->ndo_vflag < 1 )
123    {
124        ND_PRINT((ndo, "SYSLOG %s.%s, length: %u",
125               tok2str(syslog_facility_values, "unknown (%u)", facility),
126               tok2str(syslog_severity_values, "unknown (%u)", severity),
127               len));
128        return;
129    }
130
131    ND_PRINT((ndo, "SYSLOG, length: %u\n\tFacility %s (%u), Severity %s (%u)\n\tMsg: ",
132           len,
133           tok2str(syslog_facility_values, "unknown (%u)", facility),
134           facility,
135           tok2str(syslog_severity_values, "unknown (%u)", severity),
136           severity));
137
138    /* print the syslog text in verbose mode */
139    for (; msg_off < len; msg_off++) {
140        ND_TCHECK2(*(pptr + msg_off), 1);
141        safeputchar(ndo, *(pptr + msg_off));
142    }
143
144    if (ndo->ndo_vflag > 1)
145        print_unknown_data(ndo, pptr, "\n\t", len);
146
147    return;
148
149trunc:
150    ND_PRINT((ndo, "%s", tstr));
151}
152