9 #include <linux/netfilter/xt_statistic.h>
11 static void statistic_help(void)
14 "statistic match options:\n"
15 " --mode mode Match mode (random, nth)\n"
17 " --probability p Probability\n"
19 " --every n Match every nth packet\n"
20 " --packet p Initial counter value (0 <= p <= n-1, default 0)\n");
23 static const struct option statistic_opts[] = {
24 { "mode", 1, NULL, '1' },
25 { "probability", 1, NULL, '2' },
26 { "every", 1, NULL, '3' },
27 { "packet", 1, NULL, '4' },
31 static struct xt_statistic_info *global_info;
33 static void statistic_mt_init(struct xt_entry_match *match)
35 global_info = (void *)match->data;
39 statistic_parse(int c, char **argv, int invert, unsigned int *flags,
40 const void *entry, struct xt_entry_match **match)
42 struct xt_statistic_info *info = (void *)(*match)->data;
46 info->flags |= XT_STATISTIC_INVERT;
51 exit_error(PARAMETER_PROBLEM, "double --mode");
52 if (!strcmp(optarg, "random"))
53 info->mode = XT_STATISTIC_MODE_RANDOM;
54 else if (!strcmp(optarg, "nth"))
55 info->mode = XT_STATISTIC_MODE_NTH;
57 exit_error(PARAMETER_PROBLEM, "Bad mode `%s'", optarg);
62 exit_error(PARAMETER_PROBLEM, "double --probability");
64 if (prob < 0 || prob > 1)
65 exit_error(PARAMETER_PROBLEM,
66 "--probability must be between 0 and 1");
67 info->u.random.probability = 0x80000000 * prob;
72 exit_error(PARAMETER_PROBLEM, "double --every");
73 if (string_to_number(optarg, 0, 0xFFFFFFFF,
74 &info->u.nth.every) == -1)
75 exit_error(PARAMETER_PROBLEM,
76 "cannot parse --every `%s'", optarg);
77 if (info->u.nth.every == 0)
78 exit_error(PARAMETER_PROBLEM, "--every cannot be 0");
84 exit_error(PARAMETER_PROBLEM, "double --packet");
85 if (string_to_number(optarg, 0, 0xFFFFFFFF,
86 &info->u.nth.packet) == -1)
87 exit_error(PARAMETER_PROBLEM,
88 "cannot parse --packet `%s'", optarg);
97 /* Final check; must have specified --mark. */
98 static void statistic_check(unsigned int flags)
101 exit_error(PARAMETER_PROBLEM, "no mode specified");
102 if ((flags & 0x2) && (flags & (0x4 | 0x8)))
103 exit_error(PARAMETER_PROBLEM,
104 "both nth and random parameters given");
105 if (flags & 0x2 && global_info->mode != XT_STATISTIC_MODE_RANDOM)
106 exit_error(PARAMETER_PROBLEM,
107 "--probability can only be used in random mode");
108 if (flags & 0x4 && global_info->mode != XT_STATISTIC_MODE_NTH)
109 exit_error(PARAMETER_PROBLEM,
110 "--every can only be used in nth mode");
111 if (flags & 0x8 && global_info->mode != XT_STATISTIC_MODE_NTH)
112 exit_error(PARAMETER_PROBLEM,
113 "--packet can only be used in nth mode");
114 if ((flags & 0x8) && !(flags & 0x4))
115 exit_error(PARAMETER_PROBLEM,
116 "--packet can only be used with --every");
117 /* at this point, info->u.nth.every have been decreased. */
118 if (global_info->u.nth.packet > global_info->u.nth.every)
119 exit_error(PARAMETER_PROBLEM,
120 "the --packet p must be 0 <= p <= n-1");
123 global_info->u.nth.count = global_info->u.nth.every -
124 global_info->u.nth.packet;
127 /* Prints out the matchinfo. */
128 static void print_match(const struct xt_statistic_info *info, char *prefix)
130 if (info->flags & XT_STATISTIC_INVERT)
133 switch (info->mode) {
134 case XT_STATISTIC_MODE_RANDOM:
135 printf("%smode random %sprobability %f ", prefix, prefix,
136 1.0 * info->u.random.probability / 0x80000000);
138 case XT_STATISTIC_MODE_NTH:
139 printf("%smode nth %severy %u ", prefix, prefix,
140 info->u.nth.every + 1);
141 if (info->u.nth.packet)
142 printf("%spacket %u ", prefix, info->u.nth.packet);
148 statistic_print(const void *ip, const struct xt_entry_match *match, int numeric)
150 struct xt_statistic_info *info = (struct xt_statistic_info *)match->data;
152 printf("statistic ");
153 print_match(info, "");
156 /* Saves the union ipt_matchinfo in parsable form to stdout. */
157 static void statistic_save(const void *ip, const struct xt_entry_match *match)
159 struct xt_statistic_info *info = (struct xt_statistic_info *)match->data;
161 print_match(info, "--");
164 static struct xtables_match statistic_match = {
167 .version = XTABLES_VERSION,
168 .size = XT_ALIGN(sizeof(struct xt_statistic_info)),
169 .userspacesize = offsetof(struct xt_statistic_info, u.nth.count),
170 .init = statistic_mt_init,
171 .help = statistic_help,
172 .parse = statistic_parse,
173 .final_check = statistic_check,
174 .print = statistic_print,
175 .save = statistic_save,
176 .extra_opts = statistic_opts,
181 xtables_register_match(&statistic_match);