1 /* Shared library add-on to iptables to add recent matching support. */
9 #include <linux/netfilter_ipv4/ipt_recent.h>
11 /* Need these in order to not fail when compiling against an older kernel. */
13 #define RECENT_NAME "ipt_recent"
14 #endif /* RECENT_NAME */
17 #define RECENT_VER "unknown"
18 #endif /* RECENT_VER */
20 #ifndef IPT_RECENT_NAME_LEN
21 #define IPT_RECENT_NAME_LEN 200
22 #endif /* IPT_RECENT_NAME_LEN */
24 /* Options for this module */
25 static struct option opts[] = {
26 { .name = "set", .has_arg = 0, .flag = 0, .val = 201 },
27 { .name = "rcheck", .has_arg = 0, .flag = 0, .val = 202 },
28 { .name = "update", .has_arg = 0, .flag = 0, .val = 203 },
29 { .name = "seconds", .has_arg = 1, .flag = 0, .val = 204 },
30 { .name = "hitcount", .has_arg = 1, .flag = 0, .val = 205 },
31 { .name = "remove", .has_arg = 0, .flag = 0, .val = 206 },
32 { .name = "rttl", .has_arg = 0, .flag = 0, .val = 207 },
33 { .name = "name", .has_arg = 1, .flag = 0, .val = 208 },
34 { .name = "rsource", .has_arg = 0, .flag = 0, .val = 209 },
35 { .name = "rdest", .has_arg = 0, .flag = 0, .val = 210 },
36 { .name = 0, .has_arg = 0, .flag = 0, .val = 0 }
39 /* Function which prints out usage message. */
44 "recent v%s options:\n"
45 "[!] --set Add source address to list, always matches.\n"
46 "[!] --rcheck Match if source address in list.\n"
47 "[!] --update Match if source address in list, also update last-seen time.\n"
48 "[!] --remove Match if source address in list, also removes that address from list.\n"
49 " --seconds seconds For check and update commands above.\n"
50 " Specifies that the match will only occur if source address last seen within\n"
51 " the last 'seconds' seconds.\n"
52 " --hitcount hits For check and update commands above.\n"
53 " Specifies that the match will only occur if source address seen hits times.\n"
54 " May be used in conjunction with the seconds option.\n"
55 " --rttl For check and update commands above.\n"
56 " Specifies that the match will only occur if the source address and the TTL\n"
57 " match between this packet and the one which was set.\n"
58 " Useful if you have problems with people spoofing their source address in order\n"
59 " to DoS you via this module.\n"
60 " --name name Name of the recent list to be used. DEFAULT used if none given.\n"
61 " --rsource Match/Save the source address of each packet in the recent list table (default).\n"
62 " --rdest Match/Save the destination address of each packet in the recent list table.\n"
63 RECENT_NAME " " RECENT_VER ": Stephen Frost <sfrost@snowman.net>. http://snowman.net/projects/ipt_recent/\n"
69 /* Initialize the match. */
71 init(struct ipt_entry_match *match, unsigned int *nfcache)
73 struct ipt_recent_info *info = (struct ipt_recent_info *)(match)->data;
76 strncpy(info->name,"DEFAULT",IPT_RECENT_NAME_LEN);
77 /* eventhough IPT_RECENT_NAME_LEN is currently defined as 200,
78 * better be safe, than sorry */
79 info->name[IPT_RECENT_NAME_LEN-1] = '\0';
80 info->side = IPT_RECENT_SOURCE;
83 /* Function which parses command options; returns true if it
86 parse(int c, char **argv, int invert, unsigned int *flags,
87 const struct ipt_entry *entry,
88 unsigned int *nfcache,
89 struct ipt_entry_match **match)
91 struct ipt_recent_info *info = (struct ipt_recent_info *)(*match)->data;
94 if (*flags) exit_error(PARAMETER_PROBLEM,
95 "recent: only one of `--set', `--rcheck' "
96 "`--update' or `--remove' may be set");
97 check_inverse(optarg, &invert, &optind, 0);
98 info->check_set |= IPT_RECENT_SET;
99 if (invert) info->invert = 1;
104 if (*flags) exit_error(PARAMETER_PROBLEM,
105 "recent: only one of `--set', `--rcheck' "
106 "`--update' or `--remove' may be set");
107 check_inverse(optarg, &invert, &optind, 0);
108 info->check_set |= IPT_RECENT_CHECK;
109 if(invert) info->invert = 1;
114 if (*flags) exit_error(PARAMETER_PROBLEM,
115 "recent: only one of `--set', `--rcheck' "
116 "`--update' or `--remove' may be set");
117 check_inverse(optarg, &invert, &optind, 0);
118 info->check_set |= IPT_RECENT_UPDATE;
119 if (invert) info->invert = 1;
124 if (*flags) exit_error(PARAMETER_PROBLEM,
125 "recent: only one of `--set', `--rcheck' "
126 "`--update' or `--remove' may be set");
127 check_inverse(optarg, &invert, &optind, 0);
128 info->check_set |= IPT_RECENT_REMOVE;
129 if (invert) info->invert = 1;
134 info->seconds = atoi(optarg);
138 info->hit_count = atoi(optarg);
142 info->check_set |= IPT_RECENT_TTL;
146 strncpy(info->name,optarg,IPT_RECENT_NAME_LEN);
147 info->name[IPT_RECENT_NAME_LEN-1] = '\0';
151 info->side = IPT_RECENT_SOURCE;
155 info->side = IPT_RECENT_DEST;
165 /* Final check; must have specified a specific option. */
167 final_check(unsigned int flags)
171 exit_error(PARAMETER_PROBLEM,
172 "recent: you must specify one of `--set', `--rcheck' "
173 "`--update' or `--remove'");
176 /* Prints out the matchinfo. */
178 print(const struct ipt_ip *ip,
179 const struct ipt_entry_match *match,
182 struct ipt_recent_info *info = (struct ipt_recent_info *)match->data;
188 if(info->check_set & IPT_RECENT_SET) printf("SET ");
189 if(info->check_set & IPT_RECENT_CHECK) printf("CHECK ");
190 if(info->check_set & IPT_RECENT_UPDATE) printf("UPDATE ");
191 if(info->check_set & IPT_RECENT_REMOVE) printf("REMOVE ");
192 if(info->seconds) printf("seconds: %d ",info->seconds);
193 if(info->hit_count) printf("hit_count: %d ",info->hit_count);
194 if(info->check_set & IPT_RECENT_TTL) printf("TTL-Match ");
195 if(info->name) printf("name: %s ",info->name);
196 if(info->side == IPT_RECENT_SOURCE) printf("side: source ");
197 if(info->side == IPT_RECENT_DEST) printf("side: dest");
200 /* Saves the union ipt_matchinfo in parsable form to stdout. */
202 save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
204 struct ipt_recent_info *info = (struct ipt_recent_info *)match->data;
209 if(info->check_set & IPT_RECENT_SET) printf("--set ");
210 if(info->check_set & IPT_RECENT_CHECK) printf("--rcheck ");
211 if(info->check_set & IPT_RECENT_UPDATE) printf("--update ");
212 if(info->check_set & IPT_RECENT_REMOVE) printf("--remove ");
213 if(info->seconds) printf("--seconds %d ",info->seconds);
214 if(info->hit_count) printf("--hitcount %d ",info->hit_count);
215 if(info->check_set & IPT_RECENT_TTL) printf("--rttl ");
216 if(info->name) printf("--name %s ",info->name);
217 if(info->side == IPT_RECENT_SOURCE) printf("--rsource ");
218 if(info->side == IPT_RECENT_DEST) printf("--rdest ");
221 /* Structure for iptables to use to communicate with module */
222 static struct iptables_match recent = {
225 .version = IPTABLES_VERSION,
226 .size = IPT_ALIGN(sizeof(struct ipt_recent_info)),
227 .userspacesize = IPT_ALIGN(sizeof(struct ipt_recent_info)),
231 .final_check = &final_check,
239 register_match(&recent);