/* Shared library add-on to iptables to add ESP support. */ #include #include #include #include #include #include #include #include /* Function which prints out usage message. */ static void help(void) { printf( "ESP v%s options:\n" " --espspi [!] spi[:spi]\n" " match spi (range)\n", IPTABLES_VERSION); } static struct option opts[] = { { "espspi", 1, 0, '1' }, {0} }; static u_int32_t parse_esp_spi(const char *spistr) { unsigned long int spi; char* ep; spi = strtoul(spistr,&ep,0) ; if ( spistr == ep ) { exit_error(PARAMETER_PROBLEM, "ESP no valid digits in spi `%s'", spistr); } if ( spi == ULONG_MAX && errno == ERANGE ) { exit_error(PARAMETER_PROBLEM, "spi `%s' specified too big: would overflow", spistr); } if ( *spistr != '\0' && *ep != '\0' ) { exit_error(PARAMETER_PROBLEM, "ESP error parsing spi `%s'", spistr); } return (u_int32_t) spi; } static void parse_esp_spis(const char *spistring, u_int32_t *spis) { char *buffer; char *cp; buffer = strdup(spistring); if ((cp = strchr(buffer, ':')) == NULL) spis[0] = spis[1] = parse_esp_spi(buffer); else { *cp = '\0'; cp++; spis[0] = buffer[0] ? parse_esp_spi(buffer) : 0; spis[1] = cp[0] ? parse_esp_spi(cp) : 0xFFFFFFFF; } free(buffer); } /* Initialize the match. */ static void init(struct ipt_entry_match *m, unsigned int *nfcache) { struct ipt_esp *espinfo = (struct ipt_esp *)m->data; espinfo->spis[1] = 0xFFFFFFFF; } #define ESP_SPI 0x01 /* Function which parses command options; returns true if it ate an option */ static int parse(int c, char **argv, int invert, unsigned int *flags, const struct ipt_entry *entry, unsigned int *nfcache, struct ipt_entry_match **match) { struct ipt_esp *espinfo = (struct ipt_esp *)(*match)->data; switch (c) { case '1': if (*flags & ESP_SPI) exit_error(PARAMETER_PROBLEM, "Only one `--espspi' allowed"); check_inverse(optarg, &invert, &optind, 0); parse_esp_spis(argv[optind-1], espinfo->spis); if (invert) espinfo->invflags |= IPT_ESP_INV_SPI; *flags |= ESP_SPI; break; default: return 0; } return 1; } /* Final check; we don't care. */ static void final_check(unsigned int flags) { } static void print_spis(const char *name, u_int32_t min, u_int32_t max, int invert) { const char *inv = invert ? "!" : ""; if (min != 0 || max != 0xFFFFFFFF || invert) { printf("%s", name); if (min == max) { printf(":%s", inv); printf("%u", min); } else { printf("s:%s", inv); printf("%u",min); printf(":"); printf("%u",max); } printf(" "); } } /* Prints out the union ipt_matchinfo. */ static void print(const struct ipt_ip *ip, const struct ipt_entry_match *match, int numeric) { const struct ipt_esp *esp = (struct ipt_esp *)match->data; printf("esp "); print_spis("spi", esp->spis[0], esp->spis[1], esp->invflags & IPT_ESP_INV_SPI); if (esp->invflags & ~IPT_ESP_INV_MASK) printf("Unknown invflags: 0x%X ", esp->invflags & ~IPT_ESP_INV_MASK); } /* Saves the union ipt_matchinfo in parsable form to stdout. */ static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match) { const struct ipt_esp *espinfo = (struct ipt_esp *)match->data; if (!(espinfo->spis[0] == 0 && espinfo->spis[1] == 0xFFFFFFFF)) { printf("--espspi %s", (espinfo->invflags & IPT_ESP_INV_SPI) ? "! " : ""); if (espinfo->spis[0] != espinfo->spis[1]) printf("%u:%u ", espinfo->spis[0], espinfo->spis[1]); else printf("%u ", espinfo->spis[0]); } } static struct iptables_match esp = { NULL, "esp", IPTABLES_VERSION, IPT_ALIGN(sizeof(struct ipt_esp)), IPT_ALIGN(sizeof(struct ipt_esp)), &help, &init, &parse, &final_check, &print, &save, opts }; void _init(void) { register_match(&esp); }