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 static const struct ipt_log_names ipt_log_names[]
67 = { { .name = "alert", .level = LOG_ALERT },
68 { .name = "crit", .level = LOG_CRIT },
69 { .name = "debug", .level = LOG_DEBUG },
70 { .name = "emerg", .level = LOG_EMERG },
71 { .name = "error", .level = LOG_ERR }, /* DEPRECATED */
72 { .name = "info", .level = LOG_INFO },
73 { .name = "notice", .level = LOG_NOTICE },
74 { .name = "panic", .level = LOG_EMERG }, /* DEPRECATED */
75 { .name = "warning", .level = LOG_WARNING }
76 };
77
LOG_parse(struct xt_option_call * cb)78 static void LOG_parse(struct xt_option_call *cb)
79 {
80 struct ipt_log_info *info = cb->data;
81
82 xtables_option_parse(cb);
83 switch (cb->entry->id) {
84 case O_LOG_PREFIX:
85 if (strchr(cb->arg, '\n') != NULL)
86 xtables_error(PARAMETER_PROBLEM,
87 "Newlines not allowed in --log-prefix");
88 break;
89 case O_LOG_TCPSEQ:
90 info->logflags |= IPT_LOG_TCPSEQ;
91 break;
92 case O_LOG_TCPOPTS:
93 info->logflags |= IPT_LOG_TCPOPT;
94 break;
95 case O_LOG_IPOPTS:
96 info->logflags |= IPT_LOG_IPOPT;
97 break;
98 case O_LOG_UID:
99 info->logflags |= IPT_LOG_UID;
100 break;
101 case O_LOG_MAC:
102 info->logflags |= IPT_LOG_MACDECODE;
103 break;
104 }
105 }
106
LOG_print(const void * ip,const struct xt_entry_target * target,int numeric)107 static void LOG_print(const void *ip, const struct xt_entry_target *target,
108 int numeric)
109 {
110 const struct ipt_log_info *loginfo
111 = (const struct ipt_log_info *)target->data;
112 unsigned int i = 0;
113
114 printf(" LOG");
115 if (numeric)
116 printf(" flags %u level %u",
117 loginfo->logflags, loginfo->level);
118 else {
119 for (i = 0; i < ARRAY_SIZE(ipt_log_names); ++i)
120 if (loginfo->level == ipt_log_names[i].level) {
121 printf(" level %s", ipt_log_names[i].name);
122 break;
123 }
124 if (i == ARRAY_SIZE(ipt_log_names))
125 printf(" UNKNOWN level %u", loginfo->level);
126 if (loginfo->logflags & IPT_LOG_TCPSEQ)
127 printf(" tcp-sequence");
128 if (loginfo->logflags & IPT_LOG_TCPOPT)
129 printf(" tcp-options");
130 if (loginfo->logflags & IPT_LOG_IPOPT)
131 printf(" ip-options");
132 if (loginfo->logflags & IPT_LOG_UID)
133 printf(" uid");
134 if (loginfo->logflags & IPT_LOG_MACDECODE)
135 printf(" macdecode");
136 if (loginfo->logflags & ~(IPT_LOG_MASK))
137 printf(" unknown-flags");
138 }
139
140 if (strcmp(loginfo->prefix, "") != 0)
141 printf(" prefix \"%s\"", loginfo->prefix);
142 }
143
LOG_save(const void * ip,const struct xt_entry_target * target)144 static void LOG_save(const void *ip, const struct xt_entry_target *target)
145 {
146 const struct ipt_log_info *loginfo
147 = (const struct ipt_log_info *)target->data;
148
149 if (strcmp(loginfo->prefix, "") != 0) {
150 printf(" --log-prefix");
151 xtables_save_string(loginfo->prefix);
152 }
153
154 if (loginfo->level != LOG_DEFAULT_LEVEL)
155 printf(" --log-level %d", loginfo->level);
156
157 if (loginfo->logflags & IPT_LOG_TCPSEQ)
158 printf(" --log-tcp-sequence");
159 if (loginfo->logflags & IPT_LOG_TCPOPT)
160 printf(" --log-tcp-options");
161 if (loginfo->logflags & IPT_LOG_IPOPT)
162 printf(" --log-ip-options");
163 if (loginfo->logflags & IPT_LOG_UID)
164 printf(" --log-uid");
165 if (loginfo->logflags & IPT_LOG_MACDECODE)
166 printf(" --log-macdecode");
167 }
168
169 static struct xtables_target log_tg_reg = {
170 .name = "LOG",
171 .version = XTABLES_VERSION,
172 .family = NFPROTO_IPV4,
173 .size = XT_ALIGN(sizeof(struct ipt_log_info)),
174 .userspacesize = XT_ALIGN(sizeof(struct ipt_log_info)),
175 .help = LOG_help,
176 .init = LOG_init,
177 .print = LOG_print,
178 .save = LOG_save,
179 .x6_parse = LOG_parse,
180 .x6_options = LOG_opts,
181 };
182
_init(void)183 void _init(void)
184 {
185 xtables_register_target(&log_tg_reg);
186 }
187