1 #include <stdio.h>
2 #include <string.h>
3 #include <syslog.h>
4 #include <xtables.h>
5 #include <linux/netfilter_ipv4/ipt_LOG.h>
6
7 #define LOG_DEFAULT_LEVEL LOG_WARNING
8
9 #ifndef IPT_LOG_UID /* Old kernel */
10 #define IPT_LOG_UID 0x08 /* Log UID owning local socket */
11 #undef IPT_LOG_MASK
12 #define IPT_LOG_MASK 0x0f
13 #endif
14
15 enum {
16 O_LOG_LEVEL = 0,
17 O_LOG_PREFIX,
18 O_LOG_TCPSEQ,
19 O_LOG_TCPOPTS,
20 O_LOG_IPOPTS,
21 O_LOG_UID,
22 O_LOG_MAC,
23 };
24
LOG_help(void)25 static void LOG_help(void)
26 {
27 printf(
28 "LOG target options:\n"
29 " --log-level level Level of logging (numeric or see syslog.conf)\n"
30 " --log-prefix prefix Prefix log messages with this prefix.\n\n"
31 " --log-tcp-sequence Log TCP sequence numbers.\n\n"
32 " --log-tcp-options Log TCP options.\n\n"
33 " --log-ip-options Log IP options.\n\n"
34 " --log-uid Log UID owning the local socket.\n\n"
35 " --log-macdecode Decode MAC addresses and protocol.\n\n");
36 }
37
38 #define s struct ipt_log_info
39 static const struct xt_option_entry LOG_opts[] = {
40 {.name = "log-level", .id = O_LOG_LEVEL, .type = XTTYPE_SYSLOGLEVEL,
41 .flags = XTOPT_PUT, XTOPT_POINTER(s, level)},
42 {.name = "log-prefix", .id = O_LOG_PREFIX, .type = XTTYPE_STRING,
43 .flags = XTOPT_PUT, XTOPT_POINTER(s, prefix), .min = 1},
44 {.name = "log-tcp-sequence", .id = O_LOG_TCPSEQ, .type = XTTYPE_NONE},
45 {.name = "log-tcp-options", .id = O_LOG_TCPOPTS, .type = XTTYPE_NONE},
46 {.name = "log-ip-options", .id = O_LOG_IPOPTS, .type = XTTYPE_NONE},
47 {.name = "log-uid", .id = O_LOG_UID, .type = XTTYPE_NONE},
48 {.name = "log-macdecode", .id = O_LOG_MAC, .type = XTTYPE_NONE},
49 XTOPT_TABLEEND,
50 };
51 #undef s
52
LOG_init(struct xt_entry_target * t)53 static void LOG_init(struct xt_entry_target *t)
54 {
55 struct ipt_log_info *loginfo = (struct ipt_log_info *)t->data;
56
57 loginfo->level = LOG_DEFAULT_LEVEL;
58
59 }
60
61 struct ipt_log_names {
62 const char *name;
63 unsigned int level;
64 };
65
66 struct ipt_log_xlate {
67 const char *name;
68 unsigned int level;
69 };
70
71 static const struct ipt_log_names ipt_log_names[]
72 = { { .name = "alert", .level = LOG_ALERT },
73 { .name = "crit", .level = LOG_CRIT },
74 { .name = "debug", .level = LOG_DEBUG },
75 { .name = "emerg", .level = LOG_EMERG },
76 { .name = "error", .level = LOG_ERR }, /* DEPRECATED */
77 { .name = "info", .level = LOG_INFO },
78 { .name = "notice", .level = LOG_NOTICE },
79 { .name = "panic", .level = LOG_EMERG }, /* DEPRECATED */
80 { .name = "warning", .level = LOG_WARNING }
81 };
82
LOG_parse(struct xt_option_call * cb)83 static void LOG_parse(struct xt_option_call *cb)
84 {
85 struct ipt_log_info *info = cb->data;
86
87 xtables_option_parse(cb);
88 switch (cb->entry->id) {
89 case O_LOG_PREFIX:
90 if (strchr(cb->arg, '\n') != NULL)
91 xtables_error(PARAMETER_PROBLEM,
92 "Newlines not allowed in --log-prefix");
93 break;
94 case O_LOG_TCPSEQ:
95 info->logflags |= IPT_LOG_TCPSEQ;
96 break;
97 case O_LOG_TCPOPTS:
98 info->logflags |= IPT_LOG_TCPOPT;
99 break;
100 case O_LOG_IPOPTS:
101 info->logflags |= IPT_LOG_IPOPT;
102 break;
103 case O_LOG_UID:
104 info->logflags |= IPT_LOG_UID;
105 break;
106 case O_LOG_MAC:
107 info->logflags |= IPT_LOG_MACDECODE;
108 break;
109 }
110 }
111
LOG_print(const void * ip,const struct xt_entry_target * target,int numeric)112 static void LOG_print(const void *ip, const struct xt_entry_target *target,
113 int numeric)
114 {
115 const struct ipt_log_info *loginfo
116 = (const struct ipt_log_info *)target->data;
117 unsigned int i = 0;
118
119 printf(" LOG");
120 if (numeric)
121 printf(" flags %u level %u",
122 loginfo->logflags, loginfo->level);
123 else {
124 for (i = 0; i < ARRAY_SIZE(ipt_log_names); ++i)
125 if (loginfo->level == ipt_log_names[i].level) {
126 printf(" level %s", ipt_log_names[i].name);
127 break;
128 }
129 if (i == ARRAY_SIZE(ipt_log_names))
130 printf(" UNKNOWN level %u", loginfo->level);
131 if (loginfo->logflags & IPT_LOG_TCPSEQ)
132 printf(" tcp-sequence");
133 if (loginfo->logflags & IPT_LOG_TCPOPT)
134 printf(" tcp-options");
135 if (loginfo->logflags & IPT_LOG_IPOPT)
136 printf(" ip-options");
137 if (loginfo->logflags & IPT_LOG_UID)
138 printf(" uid");
139 if (loginfo->logflags & IPT_LOG_MACDECODE)
140 printf(" macdecode");
141 if (loginfo->logflags & ~(IPT_LOG_MASK))
142 printf(" unknown-flags");
143 }
144
145 if (strcmp(loginfo->prefix, "") != 0)
146 printf(" prefix \"%s\"", loginfo->prefix);
147 }
148
LOG_save(const void * ip,const struct xt_entry_target * target)149 static void LOG_save(const void *ip, const struct xt_entry_target *target)
150 {
151 const struct ipt_log_info *loginfo
152 = (const struct ipt_log_info *)target->data;
153
154 if (strcmp(loginfo->prefix, "") != 0) {
155 printf(" --log-prefix");
156 xtables_save_string(loginfo->prefix);
157 }
158
159 if (loginfo->level != LOG_DEFAULT_LEVEL)
160 printf(" --log-level %d", loginfo->level);
161
162 if (loginfo->logflags & IPT_LOG_TCPSEQ)
163 printf(" --log-tcp-sequence");
164 if (loginfo->logflags & IPT_LOG_TCPOPT)
165 printf(" --log-tcp-options");
166 if (loginfo->logflags & IPT_LOG_IPOPT)
167 printf(" --log-ip-options");
168 if (loginfo->logflags & IPT_LOG_UID)
169 printf(" --log-uid");
170 if (loginfo->logflags & IPT_LOG_MACDECODE)
171 printf(" --log-macdecode");
172 }
173
174 static const struct ipt_log_xlate ipt_log_xlate_names[] = {
175 {"alert", LOG_ALERT },
176 {"crit", LOG_CRIT },
177 {"debug", LOG_DEBUG },
178 {"emerg", LOG_EMERG },
179 {"err", LOG_ERR },
180 {"info", LOG_INFO },
181 {"notice", LOG_NOTICE },
182 {"warn", LOG_WARNING }
183 };
184
LOG_xlate(struct xt_xlate * xl,const struct xt_xlate_tg_params * params)185 static int LOG_xlate(struct xt_xlate *xl,
186 const struct xt_xlate_tg_params *params)
187 {
188 const struct ipt_log_info *loginfo =
189 (const struct ipt_log_info *)params->target->data;
190 unsigned int i = 0;
191
192 xt_xlate_add(xl, "log");
193 if (strcmp(loginfo->prefix, "") != 0) {
194 if (params->escape_quotes)
195 xt_xlate_add(xl, " prefix \\\"%s\\\"", loginfo->prefix);
196 else
197 xt_xlate_add(xl, " prefix \"%s\"", loginfo->prefix);
198 }
199
200 for (i = 0; i < ARRAY_SIZE(ipt_log_xlate_names); ++i)
201 if (loginfo->level != LOG_DEFAULT_LEVEL &&
202 loginfo->level == ipt_log_xlate_names[i].level) {
203 xt_xlate_add(xl, " level %s",
204 ipt_log_xlate_names[i].name);
205 break;
206 }
207
208 if ((loginfo->logflags & IPT_LOG_MASK) == IPT_LOG_MASK) {
209 xt_xlate_add(xl, " flags all");
210 } else {
211 if (loginfo->logflags & (IPT_LOG_TCPSEQ | IPT_LOG_TCPOPT)) {
212 const char *delim = " ";
213
214 xt_xlate_add(xl, " flags tcp");
215 if (loginfo->logflags & IPT_LOG_TCPSEQ) {
216 xt_xlate_add(xl, " sequence");
217 delim = ",";
218 }
219 if (loginfo->logflags & IPT_LOG_TCPOPT)
220 xt_xlate_add(xl, "%soptions", delim);
221 }
222 if (loginfo->logflags & IPT_LOG_IPOPT)
223 xt_xlate_add(xl, " flags ip options");
224 if (loginfo->logflags & IPT_LOG_UID)
225 xt_xlate_add(xl, " flags skuid");
226 if (loginfo->logflags & IPT_LOG_MACDECODE)
227 xt_xlate_add(xl, " flags ether");
228 }
229
230 return 1;
231 }
232 static struct xtables_target log_tg_reg = {
233 .name = "LOG",
234 .version = XTABLES_VERSION,
235 .family = NFPROTO_IPV4,
236 .size = XT_ALIGN(sizeof(struct ipt_log_info)),
237 .userspacesize = XT_ALIGN(sizeof(struct ipt_log_info)),
238 .help = LOG_help,
239 .init = LOG_init,
240 .print = LOG_print,
241 .save = LOG_save,
242 .x6_parse = LOG_parse,
243 .x6_options = LOG_opts,
244 .xlate = LOG_xlate,
245 };
246
_init(void)247 void _init(void)
248 {
249 xtables_register_target(&log_tg_reg);
250 }
251