release/src/router/iptables/extensions/libip6t_rt.c

   1 /* Shared library add-on to ip6tables to add Routing header support. */
   2 #include <stdio.h>
   3 #include <netdb.h>
   4 #include <string.h>
   5 #include <stdlib.h>
   6 #include <getopt.h>
   7 #include <errno.h>
   8 #include <ip6tables.h>
   9 /*#include <linux/in6.h>*/
  10 #include <linux/netfilter_ipv6/ip6t_rt.h>
  11 #include <sys/types.h>
  12 #include <sys/socket.h>
  13 #include <arpa/inet.h>
  14
  15 /*#define DEBUG 1*/
  16
  17 /* Function which prints out usage message. */
  18 static void
  19 help(void)
  20 {
  21         printf(
  22 "RT v%s options:\n"
  23 " --rt-type [!] type            match the type\n"
  24 " --rt-segsleft [!] num[:num]   match the Segments Left field (range)\n"
  25 " --rt-len [!] length           total length of this header\n"
  26 " --rt-0-res                    check the reserved filed, too (type 0)\n"
  27 " --rt-0-addrs ADDR[,ADDR...]   Type=0 addresses (list, max: %d)\n"
  28 " --rt-0-not-strict             List of Type=0 addresses not a strict list\n",
  29 IPTABLES_VERSION, IP6T_RT_HOPS);
  30 }
  31
  32 static struct option opts[] = {
  33         { "rt-type", 1, 0, '1' },
  34         { "rt-segsleft", 1, 0, '2' },
  35         { "rt-len", 1, 0, '3' },
  36         { "rt-0-res", 0, 0, '4' },
  37         { "rt-0-addrs", 1, 0, '5' },
  38         { "rt-0-not-strict", 0, 0, '6' },
  39         {0}
  40 };
  41
  42 static u_int32_t
  43 parse_rt_num(const char *idstr, const char *typestr)
  44 {
  45         unsigned long int id;
  46         char* ep;
  47
  48         id =  strtoul(idstr,&ep,0) ;
  49
  50         if ( idstr == ep ) {
  51                 exit_error(PARAMETER_PROBLEM,
  52                            "RT no valid digits in %s `%s'", typestr, idstr);
  53         }
  54         if ( id == ULONG_MAX  && errno == ERANGE ) {
  55                 exit_error(PARAMETER_PROBLEM,
  56                            "%s `%s' specified too big: would overflow",
  57                            typestr, idstr);
  58         }
  59         if ( *idstr != '\0'  && *ep != '\0' ) {
  60                 exit_error(PARAMETER_PROBLEM,
  61                            "RT error parsing %s `%s'", typestr, idstr);
  62         }
  63         return (u_int32_t) id;
  64 }
  65
  66 static void
  67 parse_rt_segsleft(const char *idstring, u_int32_t *ids)
  68 {
  69         char *buffer;
  70         char *cp;
  71
  72         buffer = strdup(idstring);
  73         if ((cp = strchr(buffer, ':')) == NULL)
  74                 ids[0] = ids[1] = parse_rt_num(buffer,"segsleft");
  75         else {
  76                 *cp = '\0';
  77                 cp++;
  78
  79                 ids[0] = buffer[0] ? parse_rt_num(buffer,"segsleft") : 0;
  80                 ids[1] = cp[0] ? parse_rt_num(cp,"segsleft") : 0xFFFFFFFF;
  81         }
  82         free(buffer);
  83 }
  84
  85 static char *
  86 addr_to_numeric(const struct in6_addr *addrp)
  87 {
  88         static char buf[50+1];
  89         return (char *)inet_ntop(AF_INET6, addrp, buf, sizeof(buf));
  90 }
  91
  92 static struct in6_addr *
  93 numeric_to_addr(const char *num)
  94 {
  95         static struct in6_addr ap;
  96         int err;
  97
  98         if ((err=inet_pton(AF_INET6, num, &ap)) == 1)
  99                 return &ap;
 100 #ifdef DEBUG
 101         fprintf(stderr, "\nnumeric2addr: %d\n", err);
 102 #endif
 103         exit_error(PARAMETER_PROBLEM, "bad address: %s", num);
 104
 105         return (struct in6_addr *)NULL;
 106 }
 107
 108
 109 static int
 110 parse_addresses(const char *addrstr, struct in6_addr *addrp)
 111 {
 112         char *buffer, *cp, *next;
 113         unsigned int i;
 114
 115         buffer = strdup(addrstr);
 116         if (!buffer) exit_error(OTHER_PROBLEM, "strdup failed");
 117
 118         for (cp=buffer, i=0; cp && i<IP6T_RT_HOPS; cp=next,i++)
 119         {
 120                 next=strchr(cp, ',');
 121                 if (next) *next++='\0';
 122                 memcpy(&(addrp[i]), numeric_to_addr(cp), sizeof(struct in6_addr));
 123 #if DEBUG
 124                 printf("addr str: %s\n", cp);
 125                 printf("addr ip6: %s\n", addr_to_numeric((numeric_to_addr(cp))));
 126                 printf("addr [%d]: %s\n", i, addr_to_numeric(&(addrp[i])));
 127 #endif
 128         }
 129         if (cp) exit_error(PARAMETER_PROBLEM, "too many addresses specified");
 130
 131         free(buffer);
 132
 133 #if DEBUG
 134         printf("addr nr: %d\n", i);
 135 #endif
 136
 137         return i;
 138 }
 139
 140 /* Initialize the match. */
 141 static void
 142 init(struct ip6t_entry_match *m, unsigned int *nfcache)
 143 {
 144         struct ip6t_rt *rtinfo = (struct ip6t_rt *)m->data;
 145
 146         rtinfo->rt_type = 0x0L;
 147         rtinfo->segsleft[0] = 0x0L;
 148         rtinfo->segsleft[1] = 0xFFFFFFFF;
 149         rtinfo->hdrlen = 0;
 150         rtinfo->flags = 0;
 151         rtinfo->invflags = 0;
 152         rtinfo->addrnr = 0;
 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_rt *rtinfo = (struct ip6t_rt *)(*match)->data;
 164
 165         switch (c) {
 166         case '1':
 167                 if (*flags & IP6T_RT_TYP)
 168                         exit_error(PARAMETER_PROBLEM,
 169                                    "Only one `--rt-type' allowed");
 170                 check_inverse(optarg, &invert, &optind, 0);
 171                 rtinfo->rt_type = parse_rt_num(argv[optind-1], "type");
 172                 if (invert)
 173                         rtinfo->invflags |= IP6T_RT_INV_TYP;
 174                 rtinfo->flags |= IP6T_RT_TYP;
 175                 *flags |= IP6T_RT_TYP;
 176                 break;
 177         case '2':
 178                 if (*flags & IP6T_RT_SGS)
 179                         exit_error(PARAMETER_PROBLEM,
 180                                    "Only one `--rt-segsleft' allowed");
 181                 check_inverse(optarg, &invert, &optind, 0);
 182                 parse_rt_segsleft(argv[optind-1], rtinfo->segsleft);
 183                 if (invert)
 184                         rtinfo->invflags |= IP6T_RT_INV_SGS;
 185                 rtinfo->flags |= IP6T_RT_SGS;
 186                 *flags |= IP6T_RT_SGS;
 187                 break;
 188         case '3':
 189                 if (*flags & IP6T_RT_LEN)
 190                         exit_error(PARAMETER_PROBLEM,
 191                                    "Only one `--rt-len' allowed");
 192                 check_inverse(optarg, &invert, &optind, 0);
 193                 rtinfo->hdrlen = parse_rt_num(argv[optind-1], "length");
 194                 if (invert)
 195                         rtinfo->invflags |= IP6T_RT_INV_LEN;
 196                 rtinfo->flags |= IP6T_RT_LEN;
 197                 *flags |= IP6T_RT_LEN;
 198                 break;
 199         case '4':
 200                 if (*flags & IP6T_RT_RES)
 201                         exit_error(PARAMETER_PROBLEM,
 202                                    "Only one `--rt-0-res' allowed");
 203                 if ( !(*flags & IP6T_RT_TYP) || (rtinfo->rt_type != 0) || (rtinfo->invflags & IP6T_RT_INV_TYP) )
 204                         exit_error(PARAMETER_PROBLEM,
 205                                    "`--rt-type 0' required before `--rt-0-res'");
 206                 rtinfo->flags |= IP6T_RT_RES;
 207                 *flags |= IP6T_RT_RES;
 208                 break;
 209         case '5':
 210                 if (*flags & IP6T_RT_FST)
 211                         exit_error(PARAMETER_PROBLEM,
 212                                    "Only one `--rt-0-addrs' allowed");
 213                 if ( !(*flags & IP6T_RT_TYP) || (rtinfo->rt_type != 0) || (rtinfo->invflags & IP6T_RT_INV_TYP) )
 214                         exit_error(PARAMETER_PROBLEM,
 215                                    "`--rt-type 0' required before `--rt-0-addrs'");
 216                 check_inverse(optarg, &invert, &optind, 0);
 217                 if (invert)
 218                         exit_error(PARAMETER_PROBLEM,
 219                                    " '!' not allowed with `--rt-0-addrs'");
 220                 rtinfo->addrnr = parse_addresses(argv[optind-1], rtinfo->addrs);
 221                 rtinfo->flags |= IP6T_RT_FST;
 222                 *flags |= IP6T_RT_FST;
 223                 break;
 224         case '6':
 225                 if (*flags & IP6T_RT_FST_NSTRICT)
 226                         exit_error(PARAMETER_PROBLEM,
 227                                    "Only one `--rt-0-not-strict' allowed");
 228                 if ( !(*flags & IP6T_RT_FST) )
 229                         exit_error(PARAMETER_PROBLEM,
 230                                    "`--rt-0-addr ...' required before `--rt-0-not-strict'");
 231                 rtinfo->flags |= IP6T_RT_FST_NSTRICT;
 232                 *flags |= IP6T_RT_FST_NSTRICT;
 233                 break;
 234         default:
 235                 return 0;
 236         }
 237
 238         return 1;
 239 }
 240
 241 /* Final check; we don't care. */
 242 static void
 243 final_check(unsigned int flags)
 244 {
 245 }
 246
 247 static void
 248 print_nums(const char *name, u_int32_t min, u_int32_t max,
 249             int invert)
 250 {
 251         const char *inv = invert ? "!" : "";
 252
 253         if (min != 0 || max != 0xFFFFFFFF || invert) {
 254                 printf("%s", name);
 255                 if (min == max) {
 256                         printf(":%s", inv);
 257                         printf("%u", min);
 258                 } else {
 259                         printf("s:%s", inv);
 260                         printf("%u",min);
 261                         printf(":");
 262                         printf("%u",max);
 263                 }
 264                 printf(" ");
 265         }
 266 }
 267
 268 static void
 269 print_addresses(int addrnr, struct in6_addr *addrp)
 270 {
 271         unsigned int i;
 272
 273         for(i=0; i<addrnr; i++){
 274                 printf("%s%c", addr_to_numeric(&(addrp[i])), (i!=addrnr-1)?',':' ');
 275         }
 276 }
 277
 278 /* Prints out the union ip6t_matchinfo. */
 279 static void
 280 print(const struct ip6t_ip6 *ip,
 281       const struct ip6t_entry_match *match, int numeric)
 282 {
 283         const struct ip6t_rt *rtinfo = (struct ip6t_rt *)match->data;
 284
 285         printf("rt ");
 286         if (rtinfo->flags & IP6T_RT_TYP)
 287             printf("type:%s%d ", rtinfo->invflags & IP6T_RT_INV_TYP ? "!" : "",
 288                     rtinfo->rt_type);
 289         print_nums("segsleft", rtinfo->segsleft[0], rtinfo->segsleft[1],
 290                     rtinfo->invflags & IP6T_RT_INV_SGS);
 291         if (rtinfo->flags & IP6T_RT_LEN) {
 292                 printf("length");
 293                 printf(":%s", rtinfo->invflags & IP6T_RT_INV_LEN ? "!" : "");
 294                 printf("%u", rtinfo->hdrlen);
 295                 printf(" ");
 296         }
 297         if (rtinfo->flags & IP6T_RT_RES) printf("reserved ");
 298         if (rtinfo->flags & IP6T_RT_FST) printf("0-addrs ");
 299         print_addresses(rtinfo->addrnr, (struct in6_addr *)rtinfo->addrs);
 300         if (rtinfo->flags & IP6T_RT_FST_NSTRICT) printf("0-not-strict ");
 301         if (rtinfo->invflags & ~IP6T_RT_INV_MASK)
 302                 printf("Unknown invflags: 0x%X ",
 303                        rtinfo->invflags & ~IP6T_RT_INV_MASK);
 304 }
 305
 306 /* Saves the union ip6t_matchinfo in parsable form to stdout. */
 307 static void save(const struct ip6t_ip6 *ip, const struct ip6t_entry_match *match)
 308 {
 309         const struct ip6t_rt *rtinfo = (struct ip6t_rt *)match->data;
 310
 311         if (rtinfo->flags & IP6T_RT_TYP) {
 312                 printf("--rt-type %s%u ",
 313                         (rtinfo->invflags & IP6T_RT_INV_TYP) ? "! " : "",
 314                         rtinfo->rt_type);
 315         }
 316
 317         if (!(rtinfo->segsleft[0] == 0
 318             && rtinfo->segsleft[1] == 0xFFFFFFFF)) {
 319                 printf("--rt-segsleft %s",
 320                         (rtinfo->invflags & IP6T_RT_INV_SGS) ? "! " : "");
 321                 if (rtinfo->segsleft[0]
 322                     != rtinfo->segsleft[1])
 323                         printf("%u:%u ",
 324                                rtinfo->segsleft[0],
 325                                rtinfo->segsleft[1]);
 326                 else
 327                         printf("%u ",
 328                                rtinfo->segsleft[0]);
 329         }
 330
 331         if (rtinfo->flags & IP6T_RT_LEN) {
 332                 printf("--rt-len %s%u ",
 333                         (rtinfo->invflags & IP6T_RT_INV_LEN) ? "! " : "",
 334                         rtinfo->hdrlen);
 335         }
 336
 337         if (rtinfo->flags & IP6T_RT_RES) printf("--rt-0-res ");
 338         if (rtinfo->flags & IP6T_RT_FST) printf("--rt-0-addrs ");
 339         print_addresses(rtinfo->addrnr, (struct in6_addr *)rtinfo->addrs);
 340         if (rtinfo->flags & IP6T_RT_FST_NSTRICT) printf("--rt-0-not-strict ");
 341
 342 }
 343
 344 static struct ip6tables_match rt = {
 345         .name           = "rt",
 346         .version        = IPTABLES_VERSION,
 347         .size           = IP6T_ALIGN(sizeof(struct ip6t_rt)),
 348         .userspacesize  = IP6T_ALIGN(sizeof(struct ip6t_rt)),
 349         .help           = &help,
 350         .init           = &init,
 351         .parse          = &parse,
 352         .final_check    = &final_check,
 353         .print          = &print,
 354         .save           = &save,
 355         .extra_opts     = opts,
 356 };
 357
 358 void
 359 _init(void)
 360 {
 361         register_match6(&rt);
 362 }