| /* Shared library add-on to ip6tables to add ICMP support. */ |
| #include <stdio.h> |
| #include <netdb.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <getopt.h> |
| #include <ip6tables.h> |
| #include <linux/netfilter_ipv6/ip6_tables.h> |
| |
| 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"); |
| } |
| |
| static void icmp6_help(void) |
| { |
| printf( |
| "icmpv6 match options:\n" |
| "[!] --icmpv6-type typename match icmpv6 type\n" |
| " (or numeric type or type/code)\n"); |
| print_icmpv6types(); |
| } |
| |
| static const struct option icmp6_opts[] = { |
| { "icmpv6-type", 1, NULL, '1' }, |
| { .name = NULL } |
| }; |
| |
| 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; |
| } |
| } |
| } |
| |
| static void icmp6_init(struct xt_entry_match *m) |
| { |
| struct ip6t_icmp *icmpv6info = (struct ip6t_icmp *)m->data; |
| |
| icmpv6info->code[1] = 0xFF; |
| } |
| |
| 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); |
| } |
| |
| 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); |
| } |
| |
| 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 xtables_match icmp6_mt6_reg = { |
| .name = "icmp6", |
| .version = XTABLES_VERSION, |
| .family = NFPROTO_IPV6, |
| .size = XT_ALIGN(sizeof(struct ip6t_icmp)), |
| .userspacesize = XT_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) |
| { |
| xtables_register_match(&icmp6_mt6_reg); |
| } |