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
39static 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
51static 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
79void
80syslog_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        (void)nd_printn(ndo, pptr + msg_off, len - msg_off, NULL);
143
144    if (ndo->ndo_vflag > 1)
145        print_unknown_data(ndo, pptr, "\n\t", len);
146    return;
147
148invalid:
149    nd_print_invalid(ndo);
150}
151