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
syslog_print(netdissect_options * ndo,const u_char * pptr,u_int len)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 (void)nd_printn(ndo, pptr + msg_off, len - msg_off, NULL);
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 }
148