Harald Welte | e40b11d | 2005-08-06 21:13:04 +0000 | [diff] [blame] | 1 | /* Shared library add-on to iptables for DCCP matching |
| 2 | * |
| 3 | * (C) 2005 by Harald Welte <laforge@netfilter.org> |
| 4 | * |
| 5 | * This program is distributed under the terms of GNU GPL v2, 1991 |
| 6 | * |
| 7 | */ |
| 8 | #include <stdio.h> |
| 9 | #include <string.h> |
| 10 | #include <stdlib.h> |
| 11 | #include <getopt.h> |
| 12 | #include <netdb.h> |
| 13 | #include <ctype.h> |
| 14 | |
| 15 | #include <iptables.h> |
| 16 | #include <linux/dccp.h> |
| 17 | #include <linux/netfilter_ipv4/ip_tables.h> |
| 18 | #include <linux/netfilter_ipv4/ipt_dccp.h> |
| 19 | |
| 20 | #if 0 |
| 21 | #define DEBUGP(format, first...) printf(format, ##first) |
| 22 | #define static |
| 23 | #else |
| 24 | #define DEBUGP(format, fist...) |
| 25 | #endif |
| 26 | |
| 27 | /* Initialize the match. */ |
| 28 | static void |
| 29 | init(struct ipt_entry_match *m, |
| 30 | unsigned int *nfcache) |
| 31 | { |
| 32 | struct ipt_dccp_info *einfo = (struct ipt_dccp_info *)m->data; |
| 33 | |
| 34 | memset(einfo, 0, sizeof(struct ipt_dccp_info)); |
| 35 | } |
| 36 | |
| 37 | static void help(void) |
| 38 | { |
| 39 | printf( |
| 40 | "DCCP match v%s options\n" |
| 41 | " --source-port [!] port[:port] match source port(s)\n" |
| 42 | " --sport ...\n" |
| 43 | " --destination-port [!] port[:port] match destination port(s)\n" |
| 44 | " --dport ...\n" |
| 45 | , |
| 46 | IPTABLES_VERSION); |
| 47 | } |
| 48 | |
| 49 | static struct option opts[] = { |
| 50 | { .name = "source-port", .has_arg = 1, .flag = 0, .val = '1' }, |
| 51 | { .name = "sport", .has_arg = 1, .flag = 0, .val = '1' }, |
| 52 | { .name = "destination-port", .has_arg = 1, .flag = 0, .val = '2' }, |
| 53 | { .name = "dport", .has_arg = 1, .flag = 0, .val = '2' }, |
| 54 | { .name = "dccp-types", .has_arg = 1, .flag = 0, .val = '3' }, |
| 55 | { .name = "dccp-option", .has_arg = 1, .flag = 0, .val = '4' }, |
| 56 | { .name = 0 } |
| 57 | }; |
| 58 | |
Harald Welte | e40b11d | 2005-08-06 21:13:04 +0000 | [diff] [blame] | 59 | static void |
| 60 | parse_dccp_ports(const char *portstring, |
| 61 | u_int16_t *ports) |
| 62 | { |
| 63 | char *buffer; |
| 64 | char *cp; |
| 65 | |
| 66 | buffer = strdup(portstring); |
| 67 | DEBUGP("%s\n", portstring); |
| 68 | if ((cp = strchr(buffer, ':')) == NULL) { |
Phil Oester | dbac8ad | 2006-07-20 17:01:54 +0000 | [diff] [blame] | 69 | ports[0] = ports[1] = parse_port(buffer, "dccp"); |
Harald Welte | e40b11d | 2005-08-06 21:13:04 +0000 | [diff] [blame] | 70 | } |
| 71 | else { |
| 72 | *cp = '\0'; |
| 73 | cp++; |
| 74 | |
Phil Oester | dbac8ad | 2006-07-20 17:01:54 +0000 | [diff] [blame] | 75 | ports[0] = buffer[0] ? parse_port(buffer, "dccp") : 0; |
| 76 | ports[1] = cp[0] ? parse_port(cp, "dccp") : 0xFFFF; |
Harald Welte | e40b11d | 2005-08-06 21:13:04 +0000 | [diff] [blame] | 77 | |
| 78 | if (ports[0] > ports[1]) |
| 79 | exit_error(PARAMETER_PROBLEM, |
| 80 | "invalid portrange (min > max)"); |
| 81 | } |
| 82 | free(buffer); |
| 83 | } |
| 84 | |
| 85 | static char *dccp_pkt_types[] = { |
| 86 | [DCCP_PKT_REQUEST] = "REQUEST", |
| 87 | [DCCP_PKT_RESPONSE] = "RESPONSE", |
| 88 | [DCCP_PKT_DATA] = "DATA", |
| 89 | [DCCP_PKT_ACK] = "ACK", |
| 90 | [DCCP_PKT_DATAACK] = "DATAACK", |
| 91 | [DCCP_PKT_CLOSEREQ] = "CLOSEREQ", |
| 92 | [DCCP_PKT_CLOSE] = "CLOSE", |
| 93 | [DCCP_PKT_RESET] = "RESET", |
| 94 | [DCCP_PKT_SYNC] = "SYNC", |
| 95 | [DCCP_PKT_SYNCACK] = "SYNCACK", |
| 96 | [DCCP_PKT_INVALID] = "INVALID", |
| 97 | }; |
| 98 | |
| 99 | static u_int16_t |
| 100 | parse_dccp_types(const char *typestring) |
| 101 | { |
| 102 | u_int16_t typemask = 0; |
| 103 | char *ptr, *buffer; |
| 104 | |
| 105 | buffer = strdup(typestring); |
| 106 | |
| 107 | for (ptr = strtok(buffer, ","); ptr; ptr = strtok(NULL, ",")) { |
| 108 | unsigned int i; |
| 109 | for (i = 0; i < sizeof(dccp_pkt_types)/sizeof(char *); i++) { |
| 110 | if (!strcasecmp(dccp_pkt_types[i], ptr)) { |
| 111 | typemask |= (1 << i); |
| 112 | break; |
| 113 | } |
| 114 | } |
| 115 | if (i == sizeof(dccp_pkt_types)/sizeof(char *)) |
| 116 | exit_error(PARAMETER_PROBLEM, |
| 117 | "Unknown DCCP type `%s'", ptr); |
| 118 | } |
| 119 | |
| 120 | free(buffer); |
| 121 | return typemask; |
| 122 | } |
| 123 | |
| 124 | static u_int8_t parse_dccp_option(char *optstring) |
| 125 | { |
| 126 | unsigned int ret; |
| 127 | |
| 128 | if (string_to_number(optstring, 1, 255, &ret) == -1) |
| 129 | exit_error(PARAMETER_PROBLEM, "Bad DCCP option `%s'", |
| 130 | optstring); |
| 131 | |
| 132 | return (u_int8_t)ret; |
| 133 | } |
| 134 | |
| 135 | static int |
| 136 | parse(int c, char **argv, int invert, unsigned int *flags, |
| 137 | const struct ipt_entry *entry, |
| 138 | unsigned int *nfcache, |
| 139 | struct ipt_entry_match **match) |
| 140 | { |
| 141 | struct ipt_dccp_info *einfo |
| 142 | = (struct ipt_dccp_info *)(*match)->data; |
| 143 | |
| 144 | switch (c) { |
| 145 | case '1': |
| 146 | if (*flags & IPT_DCCP_SRC_PORTS) |
| 147 | exit_error(PARAMETER_PROBLEM, |
| 148 | "Only one `--source-port' allowed"); |
| 149 | einfo->flags |= IPT_DCCP_SRC_PORTS; |
| 150 | check_inverse(optarg, &invert, &optind, 0); |
| 151 | parse_dccp_ports(argv[optind-1], einfo->spts); |
| 152 | if (invert) |
| 153 | einfo->invflags |= IPT_DCCP_SRC_PORTS; |
| 154 | *flags |= IPT_DCCP_SRC_PORTS; |
| 155 | break; |
| 156 | |
| 157 | case '2': |
| 158 | if (*flags & IPT_DCCP_DEST_PORTS) |
| 159 | exit_error(PARAMETER_PROBLEM, |
| 160 | "Only one `--destination-port' allowed"); |
| 161 | einfo->flags |= IPT_DCCP_DEST_PORTS; |
| 162 | check_inverse(optarg, &invert, &optind, 0); |
| 163 | parse_dccp_ports(argv[optind-1], einfo->dpts); |
| 164 | if (invert) |
| 165 | einfo->invflags |= IPT_DCCP_DEST_PORTS; |
| 166 | *flags |= IPT_DCCP_DEST_PORTS; |
| 167 | break; |
| 168 | |
| 169 | case '3': |
| 170 | if (*flags & IPT_DCCP_TYPE) |
| 171 | exit_error(PARAMETER_PROBLEM, |
| 172 | "Only one `--dccp-types' allowed"); |
| 173 | einfo->flags |= IPT_DCCP_TYPE; |
| 174 | check_inverse(optarg, &invert, &optind, 0); |
| 175 | einfo->typemask = parse_dccp_types(argv[optind-1]); |
| 176 | if (invert) |
| 177 | einfo->invflags |= IPT_DCCP_TYPE; |
| 178 | *flags |= IPT_DCCP_TYPE; |
| 179 | break; |
| 180 | |
| 181 | case '4': |
| 182 | if (*flags & IPT_DCCP_OPTION) |
| 183 | exit_error(PARAMETER_PROBLEM, |
| 184 | "Only one `--dccp-option' allowed"); |
| 185 | einfo->flags |= IPT_DCCP_OPTION; |
| 186 | check_inverse(optarg, &invert, &optind, 0); |
| 187 | einfo->option = parse_dccp_option(argv[optind-1]); |
| 188 | if (invert) |
| 189 | einfo->invflags |= IPT_DCCP_OPTION; |
| 190 | *flags |= IPT_DCCP_OPTION; |
| 191 | break; |
| 192 | default: |
| 193 | return 0; |
| 194 | } |
| 195 | return 1; |
| 196 | } |
| 197 | |
| 198 | static void |
| 199 | final_check(unsigned int flags) |
| 200 | { |
| 201 | } |
| 202 | |
| 203 | static char * |
| 204 | port_to_service(int port) |
| 205 | { |
| 206 | struct servent *service; |
| 207 | |
| 208 | if ((service = getservbyport(htons(port), "dccp"))) |
| 209 | return service->s_name; |
| 210 | |
| 211 | return NULL; |
| 212 | } |
| 213 | |
| 214 | static void |
| 215 | print_port(u_int16_t port, int numeric) |
| 216 | { |
| 217 | char *service; |
| 218 | |
| 219 | if (numeric || (service = port_to_service(port)) == NULL) |
| 220 | printf("%u", port); |
| 221 | else |
| 222 | printf("%s", service); |
| 223 | } |
| 224 | |
| 225 | static void |
| 226 | print_ports(const char *name, u_int16_t min, u_int16_t max, |
| 227 | int invert, int numeric) |
| 228 | { |
| 229 | const char *inv = invert ? "!" : ""; |
| 230 | |
| 231 | if (min != 0 || max != 0xFFFF || invert) { |
| 232 | printf("%s", name); |
| 233 | if (min == max) { |
| 234 | printf(":%s", inv); |
| 235 | print_port(min, numeric); |
| 236 | } else { |
| 237 | printf("s:%s", inv); |
| 238 | print_port(min, numeric); |
| 239 | printf(":"); |
| 240 | print_port(max, numeric); |
| 241 | } |
| 242 | printf(" "); |
| 243 | } |
| 244 | } |
| 245 | |
| 246 | static void |
| 247 | print_types(u_int16_t types, int inverted, int numeric) |
| 248 | { |
| 249 | int have_type = 0; |
| 250 | |
| 251 | if (inverted) |
| 252 | printf("! "); |
| 253 | |
| 254 | while (types) { |
| 255 | unsigned int i; |
| 256 | |
| 257 | for (i = 0; !(types & (1 << i)); i++); |
| 258 | |
| 259 | if (have_type) |
| 260 | printf(","); |
| 261 | else |
| 262 | have_type = 1; |
| 263 | |
| 264 | if (numeric) |
| 265 | printf("%u", i); |
| 266 | else |
| 267 | printf("%s", dccp_pkt_types[i]); |
| 268 | |
| 269 | types &= ~(1 << i); |
| 270 | } |
| 271 | } |
| 272 | |
| 273 | static void |
| 274 | print_option(u_int8_t option, int invert, int numeric) |
| 275 | { |
| 276 | if (option || invert) |
| 277 | printf("option=%s%u ", invert ? "!" : "", option); |
| 278 | } |
| 279 | |
| 280 | /* Prints out the matchinfo. */ |
| 281 | static void |
| 282 | print(const struct ipt_ip *ip, |
| 283 | const struct ipt_entry_match *match, |
| 284 | int numeric) |
| 285 | { |
| 286 | const struct ipt_dccp_info *einfo = |
| 287 | (const struct ipt_dccp_info *)match->data; |
| 288 | |
| 289 | printf("dccp "); |
| 290 | |
| 291 | if (einfo->flags & IPT_DCCP_SRC_PORTS) { |
| 292 | print_ports("spt", einfo->spts[0], einfo->spts[1], |
| 293 | einfo->invflags & IPT_DCCP_SRC_PORTS, |
| 294 | numeric); |
| 295 | } |
| 296 | |
| 297 | if (einfo->flags & IPT_DCCP_DEST_PORTS) { |
| 298 | print_ports("dpt", einfo->dpts[0], einfo->dpts[1], |
| 299 | einfo->invflags & IPT_DCCP_DEST_PORTS, |
| 300 | numeric); |
| 301 | } |
| 302 | |
| 303 | if (einfo->flags & IPT_DCCP_TYPE) { |
| 304 | print_types(einfo->typemask, |
| 305 | einfo->invflags & IPT_DCCP_TYPE, |
| 306 | numeric); |
| 307 | } |
| 308 | |
| 309 | if (einfo->flags & IPT_DCCP_OPTION) { |
| 310 | print_option(einfo->option, |
| 311 | einfo->invflags & IPT_DCCP_OPTION, numeric); |
| 312 | } |
| 313 | } |
| 314 | |
| 315 | /* Saves the union ipt_matchinfo in parsable form to stdout. */ |
| 316 | static void |
| 317 | save(const struct ipt_ip *ip, |
| 318 | const struct ipt_entry_match *match) |
| 319 | { |
| 320 | const struct ipt_dccp_info *einfo = |
| 321 | (const struct ipt_dccp_info *)match->data; |
| 322 | |
| 323 | if (einfo->flags & IPT_DCCP_SRC_PORTS) { |
| 324 | if (einfo->invflags & IPT_DCCP_SRC_PORTS) |
| 325 | printf("! "); |
| 326 | if (einfo->spts[0] != einfo->spts[1]) |
| 327 | printf("--sport %u:%u ", |
| 328 | einfo->spts[0], einfo->spts[1]); |
| 329 | else |
| 330 | printf("--sport %u ", einfo->spts[0]); |
| 331 | } |
| 332 | |
| 333 | if (einfo->flags & IPT_DCCP_DEST_PORTS) { |
| 334 | if (einfo->invflags & IPT_DCCP_DEST_PORTS) |
| 335 | printf("! "); |
| 336 | if (einfo->dpts[0] != einfo->dpts[1]) |
| 337 | printf("--dport %u:%u ", |
| 338 | einfo->dpts[0], einfo->dpts[1]); |
| 339 | else |
| 340 | printf("--dport %u ", einfo->dpts[0]); |
| 341 | } |
| 342 | |
| 343 | if (einfo->flags & IPT_DCCP_TYPE) { |
| 344 | printf("--dccp-type "); |
| 345 | print_types(einfo->typemask, einfo->invflags & IPT_DCCP_TYPE,0); |
| 346 | } |
| 347 | |
| 348 | if (einfo->flags & IPT_DCCP_OPTION) { |
| 349 | printf("--dccp-option %s%u ", |
| 350 | einfo->typemask & IPT_DCCP_OPTION ? "! " : "", |
| 351 | einfo->option); |
| 352 | } |
| 353 | } |
| 354 | |
| 355 | static |
| 356 | struct iptables_match dccp |
| 357 | = { .name = "dccp", |
| 358 | .version = IPTABLES_VERSION, |
| 359 | .size = IPT_ALIGN(sizeof(struct ipt_dccp_info)), |
| 360 | .userspacesize = IPT_ALIGN(sizeof(struct ipt_dccp_info)), |
| 361 | .help = &help, |
| 362 | .init = &init, |
| 363 | .parse = &parse, |
| 364 | .final_check = &final_check, |
| 365 | .print = &print, |
| 366 | .save = &save, |
| 367 | .extra_opts = opts |
| 368 | }; |
| 369 | |
| 370 | void _init(void) |
| 371 | { |
| 372 | register_match(&dccp); |
| 373 | } |
| 374 | |