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 1.10 2024/09/02 16:15:33 christos Exp $");
20 #endif
21
22 /* \summary: Syslog protocol printer */
23 /* specification: RFC 3164 (not RFC 5424) */
24
25 #include <config.h>
26
27 #include "netdissect-stdinc.h"
28
29 #include "netdissect.h"
30 #include "extract.h"
31
32
33 /*
34 * tokenlists and #defines taken from Ethereal - Network traffic analyzer
35 * by Gerald Combs <gerald@ethereal.com>
36 */
37
38 #define SYSLOG_SEVERITY_MASK 0x0007 /* 0000 0000 0000 0111 */
39 #define SYSLOG_FACILITY_MASK 0x03f8 /* 0000 0011 1111 1000 */
40 #define SYSLOG_MAX_DIGITS 3 /* The maximum number of priority digits to read in. */
41
42 static const struct tok syslog_severity_values[] = {
43 { 0, "emergency" },
44 { 1, "alert" },
45 { 2, "critical" },
46 { 3, "error" },
47 { 4, "warning" },
48 { 5, "notice" },
49 { 6, "info" },
50 { 7, "debug" },
51 { 0, NULL },
52 };
53
54 static const struct tok syslog_facility_values[] = {
55 { 0, "kernel" },
56 { 1, "user" },
57 { 2, "mail" },
58 { 3, "daemon" },
59 { 4, "auth" },
60 { 5, "syslog" },
61 { 6, "lpr" },
62 { 7, "news" },
63 { 8, "uucp" },
64 { 9, "cron" },
65 { 10, "authpriv" },
66 { 11, "ftp" },
67 { 12, "ntp" },
68 { 13, "security" },
69 { 14, "console" },
70 { 15, "cron" },
71 { 16, "local0" },
72 { 17, "local1" },
73 { 18, "local2" },
74 { 19, "local3" },
75 { 20, "local4" },
76 { 21, "local5" },
77 { 22, "local6" },
78 { 23, "local7" },
79 { 0, NULL },
80 };
81
82 void
syslog_print(netdissect_options * ndo,const u_char * pptr,u_int len)83 syslog_print(netdissect_options *ndo,
84 const u_char *pptr, u_int len)
85 {
86 uint16_t msg_off = 0;
87 uint16_t pri = 0;
88 uint16_t facility,severity;
89
90 ndo->ndo_protocol = "syslog";
91 /* extract decimal figures that are
92 * encapsulated within < > tags
93 * based on this decimal figure extract the
94 * severity and facility values
95 */
96
97 if (GET_U_1(pptr) != '<')
98 goto invalid;
99 msg_off++;
100
101 while (msg_off <= SYSLOG_MAX_DIGITS &&
102 GET_U_1(pptr + msg_off) >= '0' &&
103 GET_U_1(pptr + msg_off) <= '9') {
104 pri = pri * 10 + (GET_U_1(pptr + msg_off) - '0');
105 msg_off++;
106 }
107
108 if (GET_U_1(pptr + msg_off) != '>')
109 goto invalid;
110 msg_off++;
111
112 facility = (pri & SYSLOG_FACILITY_MASK) >> 3;
113 severity = pri & SYSLOG_SEVERITY_MASK;
114
115 if (ndo->ndo_vflag < 1 ) {
116 ND_PRINT("SYSLOG %s.%s, length: %u",
117 tok2str(syslog_facility_values, "unknown (%u)", facility),
118 tok2str(syslog_severity_values, "unknown (%u)", severity),
119 len);
120 return;
121 }
122
123 ND_PRINT("SYSLOG, length: %u\n\tFacility %s (%u), Severity %s (%u)\n\tMsg: ",
124 len,
125 tok2str(syslog_facility_values, "unknown (%u)", facility),
126 facility,
127 tok2str(syslog_severity_values, "unknown (%u)", severity),
128 severity);
129
130 /* print the syslog text in verbose mode */
131 /*
132 * RFC 3164 Section 4.1.3: "There is no ending delimiter to this part.
133 * The MSG part of the syslog packet MUST contain visible (printing)
134 * characters."
135 *
136 * RFC 5424 Section 8.2: "This document does not impose any mandatory
137 * restrictions on the MSG or PARAM-VALUE content. As such, they MAY
138 * contain control characters, including the NUL character."
139 *
140 * Hence, to aid in protocol debugging, print the full MSG without
141 * beautification to make it clear what was transmitted on the wire.
142 */
143 if (len > msg_off)
144 (void)nd_printn(ndo, pptr + msg_off, len - msg_off, NULL);
145
146 if (ndo->ndo_vflag > 1)
147 print_unknown_data(ndo, pptr, "\n\t", len);
148 return;
149
150 invalid:
151 nd_print_invalid(ndo);
152 }
153