1 /* Shared library add-on to iptables to add ICMP support. */ 2 #include <stdio.h> 3 #include <netdb.h> 4 #include <string.h> 5 #include <stdlib.h> 6 #include <getopt.h> 7 #include <ip6tables.h> 8 #include <linux/netfilter_ipv6/ip6_tables.h> 9 10 struct icmpv6_names { 11 const char *name; 12 u_int8_t type; 13 u_int8_t code_min, code_max; 14 }; 15 16 static const struct icmpv6_names icmpv6_codes[] = { 17 { "destination-unreachable", 1, 0, 0xFF }, 18 { "no-route", 1, 0, 0 }, 19 { "communication-prohibited", 1, 1, 1 }, 20 { "address-unreachable", 1, 3, 3 }, 21 { "port-unreachable", 1, 4, 4 }, 22 23 { "packet-too-big", 2, 0, 0xFF }, 24 25 { "time-exceeded", 3, 0, 0xFF }, 26 /* Alias */ { "ttl-exceeded", 3, 0, 0xFF }, 27 { "ttl-zero-during-transit", 3, 0, 0 }, 28 { "ttl-zero-during-reassembly", 3, 1, 1 }, 29 30 { "parameter-problem", 4, 0, 0xFF }, 31 { "bad-header", 4, 0, 0 }, 32 { "unknown-header-type", 4, 1, 1 }, 33 { "unknown-option", 4, 2, 2 }, 34 35 { "echo-request", 128, 0, 0xFF }, 36 /* Alias */ { "ping", 128, 0, 0xFF }, 37 38 { "echo-reply", 129, 0, 0xFF }, 39 /* Alias */ { "pong", 129, 0, 0xFF }, 40 41 { "router-solicitation", 133, 0, 0xFF }, 42 43 { "router-advertisement", 134, 0, 0xFF }, 44 45 { "neighbour-solicitation", 135, 0, 0xFF }, 46 /* Alias */ { "neighbor-solicitation", 135, 0, 0xFF }, 47 48 { "neighbour-advertisement", 136, 0, 0xFF }, 49 /* Alias */ { "neighbor-advertisement", 136, 0, 0xFF }, 50 51 { "redirect", 137, 0, 0xFF }, 52 53 }; 54 55 static void 56 print_icmpv6types() 57 { 58 unsigned int i; 59 printf("Valid ICMPv6 Types:"); 60 61 for (i = 0; i < sizeof(icmpv6_codes)/sizeof(struct icmpv6_names); i++) { 62 if (i && icmpv6_codes[i].type == icmpv6_codes[i-1].type) { 63 if (icmpv6_codes[i].code_min == icmpv6_codes[i-1].code_min 64 && (icmpv6_codes[i].code_max 65 == icmpv6_codes[i-1].code_max)) 66 printf(" (%s)", icmpv6_codes[i].name); 67 else 68 printf("\n %s", icmpv6_codes[i].name); 69 } 70 else 71 printf("\n%s", icmpv6_codes[i].name); 72 } 73 printf("\n"); 74 } 75 76 /* Function which prints out usage message. */ 77 static void 78 help(void) 79 { 80 printf( 81 "ICMPv6 v%s options:\n" 82 " --icmpv6-type [!] typename match icmpv6 type\n" 83 " (or numeric type or type/code)\n" 84 "\n", IPTABLES_VERSION); 85 print_icmpv6types(); 86 } 87 88 static struct option opts[] = { 89 { "icmpv6-type", 1, 0, '1' }, 90 {0} 91 }; 92 93 static void 94 parse_icmpv6(const char *icmpv6type, u_int8_t *type, u_int8_t code[]) 95 { 96 unsigned int limit = sizeof(icmpv6_codes)/sizeof(struct icmpv6_names); 97 unsigned int match = limit; 98 unsigned int i; 99 100 for (i = 0; i < limit; i++) { 101 if (strncasecmp(icmpv6_codes[i].name, icmpv6type, strlen(icmpv6type)) 102 == 0) { 103 if (match != limit) 104 exit_error(PARAMETER_PROBLEM, 105 "Ambiguous ICMPv6 type `%s':" 106 " `%s' or `%s'?", 107 icmpv6type, 108 icmpv6_codes[match].name, 109 icmpv6_codes[i].name); 110 match = i; 111 } 112 } 113 114 if (match != limit) { 115 *type = icmpv6_codes[match].type; 116 code[0] = icmpv6_codes[match].code_min; 117 code[1] = icmpv6_codes[match].code_max; 118 } else { 119 char *slash; 120 char buffer[strlen(icmpv6type) + 1]; 121 unsigned int number; 122 123 strcpy(buffer, icmpv6type); 124 slash = strchr(buffer, '/'); 125 126 if (slash) 127 *slash = '\0'; 128 129 if (string_to_number(buffer, 0, 255, &number) == -1) 130 exit_error(PARAMETER_PROBLEM, 131 "Invalid ICMPv6 type `%s'\n", buffer); 132 *type = number; 133 if (slash) { 134 if (string_to_number(slash+1, 0, 255, &number) == -1) 135 exit_error(PARAMETER_PROBLEM, 136 "Invalid ICMPv6 code `%s'\n", 137 slash+1); 138 code[0] = code[1] = number; 139 } else { 140 code[0] = 0; 141 code[1] = 0xFF; 142 } 143 } 144 } 145 146 /* Initialize the match. */ 147 static void 148 init(struct ip6t_entry_match *m, unsigned int *nfcache) 149 { 150 struct ip6t_icmp *icmpv6info = (struct ip6t_icmp *)m->data; 151 152 icmpv6info->code[1] = 0xFF; 153 } 154 155 /* Function which parses command options; returns true if it 156 ate an option */ 157 static int 158 parse(int c, char **argv, int invert, unsigned int *flags, 159 const struct ip6t_entry *entry, 160 unsigned int *nfcache, 161 struct ip6t_entry_match **match) 162 { 163 struct ip6t_icmp *icmpv6info = (struct ip6t_icmp *)(*match)->data; 164 165 switch (c) { 166 case '1': 167 if (*flags == 1) 168 exit_error(PARAMETER_PROBLEM, 169 "icmpv6 match: only use --icmpv6-type once!"); 170 check_inverse(optarg, &invert, &optind, 0); 171 parse_icmpv6(argv[optind-1], &icmpv6info->type, 172 icmpv6info->code); 173 if (invert) 174 icmpv6info->invflags |= IP6T_ICMP_INV; 175 *flags = 1; 176 break; 177 178 default: 179 return 0; 180 } 181 182 return 1; 183 } 184 185 static void print_icmpv6type(u_int8_t type, 186 u_int8_t code_min, u_int8_t code_max, 187 int invert, 188 int numeric) 189 { 190 if (!numeric) { 191 unsigned int i; 192 193 for (i = 0; 194 i < sizeof(icmpv6_codes)/sizeof(struct icmpv6_names); 195 i++) { 196 if (icmpv6_codes[i].type == type 197 && icmpv6_codes[i].code_min == code_min 198 && icmpv6_codes[i].code_max == code_max) 199 break; 200 } 201 202 if (i != sizeof(icmpv6_codes)/sizeof(struct icmpv6_names)) { 203 printf("%s%s ", 204 invert ? "!" : "", 205 icmpv6_codes[i].name); 206 return; 207 } 208 } 209 210 if (invert) 211 printf("!"); 212 213 printf("type %u", type); 214 if (code_min == 0 && code_max == 0xFF) 215 printf(" "); 216 else if (code_min == code_max) 217 printf(" code %u ", code_min); 218 else 219 printf(" codes %u-%u ", code_min, code_max); 220 } 221 222 /* Prints out the union ipt_matchinfo. */ 223 static void 224 print(const struct ip6t_ip6 *ip, 225 const struct ip6t_entry_match *match, 226 int numeric) 227 { 228 const struct ip6t_icmp *icmpv6 = (struct ip6t_icmp *)match->data; 229 230 printf("ipv6-icmp "); 231 print_icmpv6type(icmpv6->type, icmpv6->code[0], icmpv6->code[1], 232 icmpv6->invflags & IP6T_ICMP_INV, 233 numeric); 234 235 if (icmpv6->invflags & ~IP6T_ICMP_INV) 236 printf("Unknown invflags: 0x%X ", 237 icmpv6->invflags & ~IP6T_ICMP_INV); 238 } 239 240 /* Saves the match in parsable form to stdout. */ 241 static void save(const struct ip6t_ip6 *ip, const struct ip6t_entry_match *match) 242 { 243 const struct ip6t_icmp *icmpv6 = (struct ip6t_icmp *)match->data; 244 245 if (icmpv6->invflags & IP6T_ICMP_INV) 246 printf("! "); 247 248 printf("--icmpv6-type %u", icmpv6->type); 249 if (icmpv6->code[0] != 0 || icmpv6->code[1] != 0xFF) 250 printf("/%u", icmpv6->code[0]); 251 printf(" "); 252 } 253 254 static void final_check(unsigned int flags) 255 { 256 if (!flags) 257 exit_error(PARAMETER_PROBLEM, 258 "icmpv6 match: You must specify `--icmpv6-type'"); 259 } 260 261 static struct ip6tables_match icmpv6 = { 262 .name = "icmp6", 263 .version = IPTABLES_VERSION, 264 .size = IP6T_ALIGN(sizeof(struct ip6t_icmp)), 265 .userspacesize = IP6T_ALIGN(sizeof(struct ip6t_icmp)), 266 .help = &help, 267 .init = &init, 268 .parse = &parse, 269 .final_check = &final_check, 270 .print = &print, 271 .save = &save, 272 .extra_opts = opts, 273 }; 274 275 void _init(void) 276 { 277 register_match6(&icmpv6); 278 } 279
