libip6t_icmp6.c revision e917bca09924435f3fca23c01042543b1826c81e
1/* Shared library add-on to ip6tables 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 <xtables.h> 8#include <linux/netfilter_ipv6/ip6_tables.h> 9 10struct icmpv6_names { 11 const char *name; 12 u_int8_t type; 13 u_int8_t code_min, code_max; 14}; 15 16static 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 55static void 56print_icmpv6types(void) 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 76static void icmp6_help(void) 77{ 78 printf( 79"icmpv6 match options:\n" 80"[!] --icmpv6-type typename match icmpv6 type\n" 81" (or numeric type or type/code)\n"); 82 print_icmpv6types(); 83} 84 85static const struct option icmp6_opts[] = { 86 { "icmpv6-type", 1, NULL, '1' }, 87 { .name = NULL } 88}; 89 90static void 91parse_icmpv6(const char *icmpv6type, u_int8_t *type, u_int8_t code[]) 92{ 93 unsigned int limit = sizeof(icmpv6_codes)/sizeof(struct icmpv6_names); 94 unsigned int match = limit; 95 unsigned int i; 96 97 for (i = 0; i < limit; i++) { 98 if (strncasecmp(icmpv6_codes[i].name, icmpv6type, strlen(icmpv6type)) 99 == 0) { 100 if (match != limit) 101 exit_error(PARAMETER_PROBLEM, 102 "Ambiguous ICMPv6 type `%s':" 103 " `%s' or `%s'?", 104 icmpv6type, 105 icmpv6_codes[match].name, 106 icmpv6_codes[i].name); 107 match = i; 108 } 109 } 110 111 if (match != limit) { 112 *type = icmpv6_codes[match].type; 113 code[0] = icmpv6_codes[match].code_min; 114 code[1] = icmpv6_codes[match].code_max; 115 } else { 116 char *slash; 117 char buffer[strlen(icmpv6type) + 1]; 118 unsigned int number; 119 120 strcpy(buffer, icmpv6type); 121 slash = strchr(buffer, '/'); 122 123 if (slash) 124 *slash = '\0'; 125 126 if (string_to_number(buffer, 0, UINT8_MAX, &number) == -1) 127 exit_error(PARAMETER_PROBLEM, 128 "Invalid ICMPv6 type `%s'\n", buffer); 129 *type = number; 130 if (slash) { 131 if (string_to_number(slash+1, 0, UINT8_MAX, &number) == -1) 132 exit_error(PARAMETER_PROBLEM, 133 "Invalid ICMPv6 code `%s'\n", 134 slash+1); 135 code[0] = code[1] = number; 136 } else { 137 code[0] = 0; 138 code[1] = 0xFF; 139 } 140 } 141} 142 143static void icmp6_init(struct xt_entry_match *m) 144{ 145 struct ip6t_icmp *icmpv6info = (struct ip6t_icmp *)m->data; 146 147 icmpv6info->code[1] = 0xFF; 148} 149 150static int icmp6_parse(int c, char **argv, int invert, unsigned int *flags, 151 const void *entry, struct xt_entry_match **match) 152{ 153 struct ip6t_icmp *icmpv6info = (struct ip6t_icmp *)(*match)->data; 154 155 switch (c) { 156 case '1': 157 if (*flags == 1) 158 exit_error(PARAMETER_PROBLEM, 159 "icmpv6 match: only use --icmpv6-type once!"); 160 check_inverse(optarg, &invert, &optind, 0); 161 parse_icmpv6(argv[optind-1], &icmpv6info->type, 162 icmpv6info->code); 163 if (invert) 164 icmpv6info->invflags |= IP6T_ICMP_INV; 165 *flags = 1; 166 break; 167 168 default: 169 return 0; 170 } 171 172 return 1; 173} 174 175static void print_icmpv6type(u_int8_t type, 176 u_int8_t code_min, u_int8_t code_max, 177 int invert, 178 int numeric) 179{ 180 if (!numeric) { 181 unsigned int i; 182 183 for (i = 0; 184 i < sizeof(icmpv6_codes)/sizeof(struct icmpv6_names); 185 i++) { 186 if (icmpv6_codes[i].type == type 187 && icmpv6_codes[i].code_min == code_min 188 && icmpv6_codes[i].code_max == code_max) 189 break; 190 } 191 192 if (i != sizeof(icmpv6_codes)/sizeof(struct icmpv6_names)) { 193 printf("%s%s ", 194 invert ? "!" : "", 195 icmpv6_codes[i].name); 196 return; 197 } 198 } 199 200 if (invert) 201 printf("!"); 202 203 printf("type %u", type); 204 if (code_min == 0 && code_max == 0xFF) 205 printf(" "); 206 else if (code_min == code_max) 207 printf(" code %u ", code_min); 208 else 209 printf(" codes %u-%u ", code_min, code_max); 210} 211 212static void icmp6_print(const void *ip, const struct xt_entry_match *match, 213 int numeric) 214{ 215 const struct ip6t_icmp *icmpv6 = (struct ip6t_icmp *)match->data; 216 217 printf("ipv6-icmp "); 218 print_icmpv6type(icmpv6->type, icmpv6->code[0], icmpv6->code[1], 219 icmpv6->invflags & IP6T_ICMP_INV, 220 numeric); 221 222 if (icmpv6->invflags & ~IP6T_ICMP_INV) 223 printf("Unknown invflags: 0x%X ", 224 icmpv6->invflags & ~IP6T_ICMP_INV); 225} 226 227static void icmp6_save(const void *ip, const struct xt_entry_match *match) 228{ 229 const struct ip6t_icmp *icmpv6 = (struct ip6t_icmp *)match->data; 230 231 if (icmpv6->invflags & IP6T_ICMP_INV) 232 printf("! "); 233 234 printf("--icmpv6-type %u", icmpv6->type); 235 if (icmpv6->code[0] != 0 || icmpv6->code[1] != 0xFF) 236 printf("/%u", icmpv6->code[0]); 237 printf(" "); 238} 239 240static void icmp6_check(unsigned int flags) 241{ 242 if (!flags) 243 exit_error(PARAMETER_PROBLEM, 244 "icmpv6 match: You must specify `--icmpv6-type'"); 245} 246 247static struct xtables_match icmp6_mt6_reg = { 248 .name = "icmp6", 249 .version = XTABLES_VERSION, 250 .family = NFPROTO_IPV6, 251 .size = XT_ALIGN(sizeof(struct ip6t_icmp)), 252 .userspacesize = XT_ALIGN(sizeof(struct ip6t_icmp)), 253 .help = icmp6_help, 254 .init = icmp6_init, 255 .parse = icmp6_parse, 256 .final_check = icmp6_check, 257 .print = icmp6_print, 258 .save = icmp6_save, 259 .extra_opts = icmp6_opts, 260}; 261 262void _init(void) 263{ 264 xtables_register_match(&icmp6_mt6_reg); 265} 266