/* Shared library add-on to iptables to add ICMP support. */ #include #include #include #include #include #include #include struct icmpv6_names { const char *name; u_int8_t type; u_int8_t code_min, code_max; }; static const struct icmpv6_names icmpv6_codes[] = { { "destination-unreachable", 1, 0, 0xFF }, { "no-route", 1, 0, 0 }, { "communication-prohibited", 1, 1, 1 }, { "address-unreachable", 1, 3, 3 }, { "port-unreachable", 1, 4, 4 }, { "packet-too-big", 2, 0, 0xFF }, { "time-exceeded", 3, 0, 0xFF }, /* Alias */ { "ttl-exceeded", 3, 0, 0xFF }, { "ttl-zero-during-transit", 3, 0, 0 }, { "ttl-zero-during-reassembly", 3, 1, 1 }, { "parameter-problem", 4, 0, 0xFF }, { "bad-header", 4, 0, 0 }, { "unknown-header-type", 4, 1, 1 }, { "unknown-option", 4, 2, 2 }, { "echo-request", 128, 0, 0xFF }, /* Alias */ { "ping", 128, 0, 0xFF }, { "echo-reply", 129, 0, 0xFF }, /* Alias */ { "pong", 129, 0, 0xFF }, { "router-solicitation", 133, 0, 0xFF }, { "router-advertisement", 134, 0, 0xFF }, { "neighbour-solicitation", 135, 0, 0xFF }, /* Alias */ { "neighbor-solicitation", 135, 0, 0xFF }, { "neighbour-advertisement", 136, 0, 0xFF }, /* Alias */ { "neighbor-advertisement", 136, 0, 0xFF }, { "redirect", 137, 0, 0xFF }, }; static void print_icmpv6types(void) { unsigned int i; printf("Valid ICMPv6 Types:"); for (i = 0; i < sizeof(icmpv6_codes)/sizeof(struct icmpv6_names); i++) { if (i && icmpv6_codes[i].type == icmpv6_codes[i-1].type) { if (icmpv6_codes[i].code_min == icmpv6_codes[i-1].code_min && (icmpv6_codes[i].code_max == icmpv6_codes[i-1].code_max)) printf(" (%s)", icmpv6_codes[i].name); else printf("\n %s", icmpv6_codes[i].name); } else printf("\n%s", icmpv6_codes[i].name); } printf("\n"); } /* Function which prints out usage message. */ static void icmp6_help(void) { printf( "ICMPv6 v%s options:\n" " --icmpv6-type [!] typename match icmpv6 type\n" " (or numeric type or type/code)\n" "\n", IPTABLES_VERSION); print_icmpv6types(); } static const struct option icmp6_opts[] = { { "icmpv6-type", 1, NULL, '1' }, { } }; static void parse_icmpv6(const char *icmpv6type, u_int8_t *type, u_int8_t code[]) { unsigned int limit = sizeof(icmpv6_codes)/sizeof(struct icmpv6_names); unsigned int match = limit; unsigned int i; for (i = 0; i < limit; i++) { if (strncasecmp(icmpv6_codes[i].name, icmpv6type, strlen(icmpv6type)) == 0) { if (match != limit) exit_error(PARAMETER_PROBLEM, "Ambiguous ICMPv6 type `%s':" " `%s' or `%s'?", icmpv6type, icmpv6_codes[match].name, icmpv6_codes[i].name); match = i; } } if (match != limit) { *type = icmpv6_codes[match].type; code[0] = icmpv6_codes[match].code_min; code[1] = icmpv6_codes[match].code_max; } else { char *slash; char buffer[strlen(icmpv6type) + 1]; unsigned int number; strcpy(buffer, icmpv6type); slash = strchr(buffer, '/'); if (slash) *slash = '\0'; if (string_to_number(buffer, 0, 255, &number) == -1) exit_error(PARAMETER_PROBLEM, "Invalid ICMPv6 type `%s'\n", buffer); *type = number; if (slash) { if (string_to_number(slash+1, 0, 255, &number) == -1) exit_error(PARAMETER_PROBLEM, "Invalid ICMPv6 code `%s'\n", slash+1); code[0] = code[1] = number; } else { code[0] = 0; code[1] = 0xFF; } } } /* Initialize the match. */ static void icmp6_init(struct xt_entry_match *m) { struct ip6t_icmp *icmpv6info = (struct ip6t_icmp *)m->data; icmpv6info->code[1] = 0xFF; } /* Function which parses command options; returns true if it ate an option */ static int icmp6_parse(int c, char **argv, int invert, unsigned int *flags, const void *entry, struct xt_entry_match **match) { struct ip6t_icmp *icmpv6info = (struct ip6t_icmp *)(*match)->data; switch (c) { case '1': if (*flags == 1) exit_error(PARAMETER_PROBLEM, "icmpv6 match: only use --icmpv6-type once!"); check_inverse(optarg, &invert, &optind, 0); parse_icmpv6(argv[optind-1], &icmpv6info->type, icmpv6info->code); if (invert) icmpv6info->invflags |= IP6T_ICMP_INV; *flags = 1; break; default: return 0; } return 1; } static void print_icmpv6type(u_int8_t type, u_int8_t code_min, u_int8_t code_max, int invert, int numeric) { if (!numeric) { unsigned int i; for (i = 0; i < sizeof(icmpv6_codes)/sizeof(struct icmpv6_names); i++) { if (icmpv6_codes[i].type == type && icmpv6_codes[i].code_min == code_min && icmpv6_codes[i].code_max == code_max) break; } if (i != sizeof(icmpv6_codes)/sizeof(struct icmpv6_names)) { printf("%s%s ", invert ? "!" : "", icmpv6_codes[i].name); return; } } if (invert) printf("!"); printf("type %u", type); if (code_min == 0 && code_max == 0xFF) printf(" "); else if (code_min == code_max) printf(" code %u ", code_min); else printf(" codes %u-%u ", code_min, code_max); } /* Prints out the union ipt_matchinfo. */ static void icmp6_print(const void *ip, const struct xt_entry_match *match, int numeric) { const struct ip6t_icmp *icmpv6 = (struct ip6t_icmp *)match->data; printf("ipv6-icmp "); print_icmpv6type(icmpv6->type, icmpv6->code[0], icmpv6->code[1], icmpv6->invflags & IP6T_ICMP_INV, numeric); if (icmpv6->invflags & ~IP6T_ICMP_INV) printf("Unknown invflags: 0x%X ", icmpv6->invflags & ~IP6T_ICMP_INV); } /* Saves the match in parsable form to stdout. */ static void icmp6_save(const void *ip, const struct xt_entry_match *match) { const struct ip6t_icmp *icmpv6 = (struct ip6t_icmp *)match->data; if (icmpv6->invflags & IP6T_ICMP_INV) printf("! "); printf("--icmpv6-type %u", icmpv6->type); if (icmpv6->code[0] != 0 || icmpv6->code[1] != 0xFF) printf("/%u", icmpv6->code[0]); printf(" "); } static void icmp6_check(unsigned int flags) { if (!flags) exit_error(PARAMETER_PROBLEM, "icmpv6 match: You must specify `--icmpv6-type'"); } static struct ip6tables_match icmp6_match6 = { .name = "icmp6", .version = IPTABLES_VERSION, .size = IP6T_ALIGN(sizeof(struct ip6t_icmp)), .userspacesize = IP6T_ALIGN(sizeof(struct ip6t_icmp)), .help = icmp6_help, .init = icmp6_init, .parse = icmp6_parse, .final_check = icmp6_check, .print = icmp6_print, .save = icmp6_save, .extra_opts = icmp6_opts, }; void _init(void) { register_match6(&icmp6_match6); }