sbin/ipfw/ipv6.c

   1 /*
   2  * Copyright (c) 2002-2003 Luigi Rizzo
   3  * Copyright (c) 1996 Alex Nash, Paul Traina, Poul-Henning Kamp
   4  * Copyright (c) 1994 Ugen J.S.Antsilevich
   5  *
   6  * Idea and grammar partially left from:
   7  * Copyright (c) 1993 Daniel Boulet
   8  *
   9  * Redistribution and use in source forms, with and without modification,
  10  * are permitted provided that this entire comment appears intact.
  11  *
  12  * Redistribution in binary form may occur without any restrictions.
  13  * Obviously, it would be nice if you gave credit where credit is due
  14  * but requiring it would be too onerous.
  15  *
  16  * This software is provided ``AS IS'' without any warranties of any kind.
  17  *
  18  * NEW command line interface for IP firewall facility
  19  *
  20  * $FreeBSD$
  21  *
  22  * ipv6 support
  23  */
  24
  25 #include <sys/types.h>
  26 #include <sys/socket.h>
  27
  28 #include "ipfw2.h"
  29
  30 #include <err.h>
  31 #include <netdb.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <sysexits.h>
  36
  37 #include <net/if.h>
  38 #include <netinet/in.h>
  39 #include <netinet/in_systm.h>
  40 #include <netinet/ip.h>
  41 #include <netinet/icmp6.h>
  42 #include <netinet/ip_fw.h>
  43 #include <arpa/inet.h>
  44
  45 #define CHECK_LENGTH(v, len) do {                       \
  46         if ((v) < (len))                                \
  47                 errx(EX_DATAERR, "Rule too long");      \
  48         } while (0)
  49
  50 static struct _s_x icmp6codes[] = {
  51       { "no-route",             ICMP6_DST_UNREACH_NOROUTE },
  52       { "admin-prohib",         ICMP6_DST_UNREACH_ADMIN },
  53       { "address",              ICMP6_DST_UNREACH_ADDR },
  54       { "port",                 ICMP6_DST_UNREACH_NOPORT },
  55       { NULL, 0 }
  56 };
  57
  58 void
  59 fill_unreach6_code(u_short *codep, char *str)
  60 {
  61         int val;
  62         char *s;
  63
  64         val = strtoul(str, &s, 0);
  65         if (s == str || *s != '\0' || val >= 0x100)
  66                 val = match_token(icmp6codes, str);
  67         if (val < 0)
  68                 errx(EX_DATAERR, "unknown ICMPv6 unreachable code ``%s''", str);
  69         *codep = val;
  70         return;
  71 }
  72
  73 void
  74 print_unreach6_code(struct buf_pr *bp, uint16_t code)
  75 {
  76         char const *s = match_value(icmp6codes, code);
  77
  78         if (s != NULL)
  79                 bprintf(bp, "unreach6 %s", s);
  80         else
  81                 bprintf(bp, "unreach6 %u", code);
  82 }
  83
  84 /*
  85  * Print the ip address contained in a command.
  86  */
  87 void
  88 print_ip6(struct buf_pr *bp, ipfw_insn_ip6 *cmd, char const *s)
  89 {
  90        struct hostent *he = NULL;
  91        int len = F_LEN((ipfw_insn *) cmd) - 1;
  92        struct in6_addr *a = &(cmd->addr6);
  93        char trad[255];
  94
  95        bprintf(bp, "%s%s ", cmd->o.len & F_NOT ? " not": "", s);
  96
  97        if (cmd->o.opcode == O_IP6_SRC_ME || cmd->o.opcode == O_IP6_DST_ME) {
  98                bprintf(bp, "me6");
  99                return;
 100        }
 101        if (cmd->o.opcode == O_IP6) {
 102                bprintf(bp, " ip6");
 103                return;
 104        }
 105
 106        /*
 107         * len == 4 indicates a single IP, whereas lists of 1 or more
 108         * addr/mask pairs have len = (2n+1). We convert len to n so we
 109         * use that to count the number of entries.
 110         */
 111
 112        for (len = len / 4; len > 0; len -= 2, a += 2) {
 113            int mb =     /* mask length */
 114                (cmd->o.opcode == O_IP6_SRC || cmd->o.opcode == O_IP6_DST) ?
 115                128 : contigmask((uint8_t *)&(a[1]), 128);
 116
 117            if (mb == 128 && co.do_resolv)
 118                he = gethostbyaddr((char *)a, sizeof(*a), AF_INET6);
 119            if (he != NULL)           /* resolved to name */
 120                bprintf(bp, "%s", he->h_name);
 121            else if (mb == 0)       /* any */
 122                bprintf(bp, "any");
 123            else {         /* numeric IP followed by some kind of mask */
 124                if (inet_ntop(AF_INET6,  a, trad, sizeof( trad ) ) == NULL)
 125                    bprintf(bp, "Error ntop in print_ip6\n");
 126                bprintf(bp, "%s",  trad );
 127                if (mb < 0)     /* XXX not really legal... */
 128                    bprintf(bp, ":%s",
 129                        inet_ntop(AF_INET6, &a[1], trad, sizeof(trad)));
 130                else if (mb < 128)
 131                    bprintf(bp, "/%d", mb);
 132            }
 133            if (len > 2)
 134                bprintf(bp, ",");
 135        }
 136 }
 137
 138 void
 139 fill_icmp6types(ipfw_insn_icmp6 *cmd, char *av, int cblen)
 140 {
 141        uint8_t type;
 142
 143        CHECK_LENGTH(cblen, F_INSN_SIZE(ipfw_insn_icmp6));
 144
 145        bzero(cmd, sizeof(*cmd));
 146        while (*av) {
 147            if (*av == ',')
 148                av++;
 149            type = strtoul(av, &av, 0);
 150            if (*av != ',' && *av != '\0')
 151                errx(EX_DATAERR, "invalid ICMP6 type");
 152            /*
 153             * XXX: shouldn't this be 0xFF?  I can't see any reason why
 154             * we shouldn't be able to filter all possiable values
 155             * regardless of the ability of the rest of the kernel to do
 156             * anything useful with them.
 157             */
 158            if (type > ICMP6_MAXTYPE)
 159                errx(EX_DATAERR, "ICMP6 type out of range");
 160            cmd->d[type / 32] |= ( 1 << (type % 32));
 161        }
 162        cmd->o.opcode = O_ICMP6TYPE;
 163        cmd->o.len |= F_INSN_SIZE(ipfw_insn_icmp6);
 164 }
 165
 166
 167 void
 168 print_icmp6types(struct buf_pr *bp, ipfw_insn_u32 *cmd)
 169 {
 170        int i, j;
 171        char sep= ' ';
 172
 173        bprintf(bp, " ip6 icmp6types");
 174        for (i = 0; i < 7; i++)
 175                for (j=0; j < 32; ++j) {
 176                        if ( (cmd->d[i] & (1 << (j))) == 0)
 177                                continue;
 178                        bprintf(bp, "%c%d", sep, (i*32 + j));
 179                        sep = ',';
 180                }
 181 }
 182
 183 void
 184 print_flow6id(struct buf_pr *bp, ipfw_insn_u32 *cmd)
 185 {
 186        uint16_t i, limit = cmd->o.arg1;
 187        char sep = ',';
 188
 189        bprintf(bp, " flow-id ");
 190        for( i=0; i < limit; ++i) {
 191                if (i == limit - 1)
 192                        sep = ' ';
 193                bprintf(bp, "%d%c", cmd->d[i], sep);
 194        }
 195 }
 196
 197 /* structure and define for the extension header in ipv6 */
 198 static struct _s_x ext6hdrcodes[] = {
 199        { "frag",       EXT_FRAGMENT },
 200        { "hopopt",     EXT_HOPOPTS },
 201        { "route",      EXT_ROUTING },
 202        { "dstopt",     EXT_DSTOPTS },
 203        { "ah",   EXT_AH },
 204        { "esp", EXT_ESP },
 205        { "rthdr0",     EXT_RTHDR0 },
 206        { "rthdr2",     EXT_RTHDR2 },
 207        { NULL,   0 }
 208 };
 209
 210 /* fills command for the extension header filtering */
 211 int
 212 fill_ext6hdr( ipfw_insn *cmd, char *av)
 213 {
 214        int tok;
 215        char *s = av;
 216
 217        cmd->arg1 = 0;
 218
 219        while(s) {
 220            av = strsep( &s, ",") ;
 221            tok = match_token(ext6hdrcodes, av);
 222            switch (tok) {
 223            case EXT_FRAGMENT:
 224                cmd->arg1 |= EXT_FRAGMENT;
 225                break;
 226
 227            case EXT_HOPOPTS:
 228                cmd->arg1 |= EXT_HOPOPTS;
 229                break;
 230
 231            case EXT_ROUTING:
 232                cmd->arg1 |= EXT_ROUTING;
 233                break;
 234
 235            case EXT_DSTOPTS:
 236                cmd->arg1 |= EXT_DSTOPTS;
 237                break;
 238
 239            case EXT_AH:
 240                cmd->arg1 |= EXT_AH;
 241                break;
 242
 243            case EXT_ESP:
 244                cmd->arg1 |= EXT_ESP;
 245                break;
 246
 247            case EXT_RTHDR0:
 248                cmd->arg1 |= EXT_RTHDR0;
 249                break;
 250
 251            case EXT_RTHDR2:
 252                cmd->arg1 |= EXT_RTHDR2;
 253                break;
 254
 255            default:
 256                errx( EX_DATAERR, "invalid option for ipv6 exten header" );
 257                break;
 258            }
 259        }
 260        if (cmd->arg1 == 0 )
 261            return 0;
 262        cmd->opcode = O_EXT_HDR;
 263        cmd->len |= F_INSN_SIZE( ipfw_insn );
 264        return 1;
 265 }
 266
 267 void
 268 print_ext6hdr(struct buf_pr *bp, ipfw_insn *cmd )
 269 {
 270        char sep = ' ';
 271
 272        bprintf(bp, " extension header:");
 273        if (cmd->arg1 & EXT_FRAGMENT ) {
 274            bprintf(bp, "%cfragmentation", sep);
 275            sep = ',';
 276        }
 277        if (cmd->arg1 & EXT_HOPOPTS ) {
 278            bprintf(bp, "%chop options", sep);
 279            sep = ',';
 280        }
 281        if (cmd->arg1 & EXT_ROUTING ) {
 282            bprintf(bp, "%crouting options", sep);
 283            sep = ',';
 284        }
 285        if (cmd->arg1 & EXT_RTHDR0 ) {
 286            bprintf(bp, "%crthdr0", sep);
 287            sep = ',';
 288        }
 289        if (cmd->arg1 & EXT_RTHDR2 ) {
 290            bprintf(bp, "%crthdr2", sep);
 291            sep = ',';
 292        }
 293        if (cmd->arg1 & EXT_DSTOPTS ) {
 294            bprintf(bp, "%cdestination options", sep);
 295            sep = ',';
 296        }
 297        if (cmd->arg1 & EXT_AH ) {
 298            bprintf(bp, "%cauthentication header", sep);
 299            sep = ',';
 300        }
 301        if (cmd->arg1 & EXT_ESP ) {
 302            bprintf(bp, "%cencapsulated security payload", sep);
 303        }
 304 }
 305
 306 /* Try to find ipv6 address by hostname */
 307 static int
 308 lookup_host6 (char *host, struct in6_addr *ip6addr)
 309 {
 310         struct hostent *he;
 311
 312         if (!inet_pton(AF_INET6, host, ip6addr)) {
 313                 if ((he = gethostbyname2(host, AF_INET6)) == NULL)
 314                         return(-1);
 315                 memcpy(ip6addr, he->h_addr_list[0], sizeof( struct in6_addr));
 316         }
 317         return(0);
 318 }
 319
 320
 321 /*
 322  * fill the addr and mask fields in the instruction as appropriate from av.
 323  * Update length as appropriate.
 324  * The following formats are allowed:
 325  *     any     matches any IP6. Actually returns an empty instruction.
 326  *     me      returns O_IP6_*_ME
 327  *
 328  *     03f1::234:123:0342               single IP6 address
 329  *     03f1::234:123:0342/24        address/mask
 330  *     03f1::234:123:0342/24,03f1::234:123:0343/               List of address
 331  *
 332  * Set of address (as in ipv6) not supported because ipv6 address
 333  * are typically random past the initial prefix.
 334  * Return 1 on success, 0 on failure.
 335  */
 336 static int
 337 fill_ip6(ipfw_insn_ip6 *cmd, char *av, int cblen)
 338 {
 339         int len = 0;
 340         struct in6_addr *d = &(cmd->addr6);
 341         /*
 342          * Needed for multiple address.
 343          * Note d[1] points to struct in6_add r mask6 of cmd
 344          */
 345
 346         cmd->o.len &= ~F_LEN_MASK;      /* zero len */
 347
 348         if (strcmp(av, "any") == 0)
 349                 return (1);
 350
 351
 352         if (strcmp(av, "me") == 0) {    /* Set the data for "me" opt*/
 353                 cmd->o.len |= F_INSN_SIZE(ipfw_insn);
 354                 return (1);
 355         }
 356
 357         if (strcmp(av, "me6") == 0) {   /* Set the data for "me" opt*/
 358                 cmd->o.len |= F_INSN_SIZE(ipfw_insn);
 359                 return (1);
 360         }
 361
 362         if (strncmp(av, "table(", 6) == 0) {
 363                 char *p = strchr(av + 6, ',');
 364                 uint32_t *dm = ((ipfw_insn_u32 *)cmd)->d;
 365
 366                 if (p)
 367                         *p++ = '\0';
 368                 cmd->o.opcode = O_IP_DST_LOOKUP;
 369                 cmd->o.arg1 = strtoul(av + 6, NULL, 0);
 370                 if (p) {
 371                         cmd->o.len |= F_INSN_SIZE(ipfw_insn_u32);
 372                         dm[0] = strtoul(p, NULL, 0);
 373                 } else
 374                         cmd->o.len |= F_INSN_SIZE(ipfw_insn);
 375                 return (1);
 376         }
 377
 378         av = strdup(av);
 379         while (av) {
 380                 /*
 381                  * After the address we can have '/' indicating a mask,
 382                  * or ',' indicating another address follows.
 383                  */
 384
 385                 char *p;
 386                 int masklen;
 387                 char md = '\0';
 388
 389                 CHECK_LENGTH(cblen, 1 + len + 2 * F_INSN_SIZE(struct in6_addr));
 390
 391                 if ((p = strpbrk(av, "/,")) ) {
 392                         md = *p;        /* save the separator */
 393                         *p = '\0';      /* terminate address string */
 394                         p++;            /* and skip past it */
 395                 }
 396                 /* now p points to NULL, mask or next entry */
 397
 398                 /* lookup stores address in *d as a side effect */
 399                 if (lookup_host6(av, d) != 0) {
 400                         /* XXX: failed. Free memory and go */
 401                         errx(EX_DATAERR, "bad address \"%s\"", av);
 402                 }
 403                 /* next, look at the mask, if any */
 404                 masklen = (md == '/') ? atoi(p) : 128;
 405                 if (masklen > 128 || masklen < 0)
 406                         errx(EX_DATAERR, "bad width \"%s\''", p);
 407                 else
 408                         n2mask(&d[1], masklen);
 409
 410                 APPLY_MASK(d, &d[1])   /* mask base address with mask */
 411
 412                 /* find next separator */
 413
 414                 if (md == '/') {        /* find separator past the mask */
 415                         p = strpbrk(p, ",");
 416                         if (p != NULL)
 417                                 p++;
 418                 }
 419                 av = p;
 420
 421                 /* Check this entry */
 422                 if (masklen == 0) {
 423                         /*
 424                          * 'any' turns the entire list into a NOP.
 425                          * 'not any' never matches, so it is removed from the
 426                          * list unless it is the only item, in which case we
 427                          * report an error.
 428                          */
 429                         if (cmd->o.len & F_NOT && av == NULL && len == 0)
 430                                 errx(EX_DATAERR, "not any never matches");
 431                         continue;
 432                 }
 433
 434                 /*
 435                  * A single IP can be stored alone
 436                  */
 437                 if (masklen == 128 && av == NULL && len == 0) {
 438                         len = F_INSN_SIZE(struct in6_addr);
 439                         break;
 440                 }
 441
 442                 /* Update length and pointer to arguments */
 443                 len += F_INSN_SIZE(struct in6_addr)*2;
 444                 d += 2;
 445         } /* end while */
 446
 447         /*
 448          * Total length of the command, remember that 1 is the size of
 449          * the base command.
 450          */
 451         if (len + 1 > F_LEN_MASK)
 452                 errx(EX_DATAERR, "address list too long");
 453         cmd->o.len |= len+1;
 454         free(av);
 455         return (1);
 456 }
 457
 458 /*
 459  * fills command for ipv6 flow-id filtering
 460  * note that the 20 bit flow number is stored in a array of u_int32_t
 461  * it's supported lists of flow-id, so in the o.arg1 we store how many
 462  * additional flow-id we want to filter, the basic is 1
 463  */
 464 void
 465 fill_flow6( ipfw_insn_u32 *cmd, char *av, int cblen)
 466 {
 467         u_int32_t type;  /* Current flow number */
 468         u_int16_t nflow = 0;    /* Current flow index */
 469         char *s = av;
 470         cmd->d[0] = 0;    /* Initializing the base number*/
 471
 472         while (s) {
 473                 CHECK_LENGTH(cblen, F_INSN_SIZE(ipfw_insn_u32) + nflow + 1);
 474
 475                 av = strsep( &s, ",") ;
 476                 type = strtoul(av, &av, 0);
 477                 if (*av != ',' && *av != '\0')
 478                         errx(EX_DATAERR, "invalid ipv6 flow number %s", av);
 479                 if (type > 0xfffff)
 480                         errx(EX_DATAERR, "flow number out of range %s", av);
 481                 cmd->d[nflow] |= type;
 482                 nflow++;
 483         }
 484         if( nflow > 0 ) {
 485                 cmd->o.opcode = O_FLOW6ID;
 486                 cmd->o.len |= F_INSN_SIZE(ipfw_insn_u32) + nflow;
 487                 cmd->o.arg1 = nflow;
 488         }
 489         else {
 490                 errx(EX_DATAERR, "invalid ipv6 flow number %s", av);
 491         }
 492 }
 493
 494 ipfw_insn *
 495 add_srcip6(ipfw_insn *cmd, char *av, int cblen)
 496 {
 497
 498         fill_ip6((ipfw_insn_ip6 *)cmd, av, cblen);
 499         if (cmd->opcode == O_IP_DST_SET)                        /* set */
 500                 cmd->opcode = O_IP_SRC_SET;
 501         else if (cmd->opcode == O_IP_DST_LOOKUP)                /* table */
 502                 cmd->opcode = O_IP_SRC_LOOKUP;
 503         else if (F_LEN(cmd) == 0) {                             /* any */
 504         } else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) {      /* "me" */
 505                 cmd->opcode = O_IP6_SRC_ME;
 506         } else if (F_LEN(cmd) ==
 507             (F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {
 508                 /* single IP, no mask*/
 509                 cmd->opcode = O_IP6_SRC;
 510         } else {                                        /* addr/mask opt */
 511                 cmd->opcode = O_IP6_SRC_MASK;
 512         }
 513         return cmd;
 514 }
 515
 516 ipfw_insn *
 517 add_dstip6(ipfw_insn *cmd, char *av, int cblen)
 518 {
 519
 520         fill_ip6((ipfw_insn_ip6 *)cmd, av, cblen);
 521         if (cmd->opcode == O_IP_DST_SET)                        /* set */
 522                 ;
 523         else if (cmd->opcode == O_IP_DST_LOOKUP)                /* table */
 524                 ;
 525         else if (F_LEN(cmd) == 0) {                             /* any */
 526         } else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) {      /* "me" */
 527                 cmd->opcode = O_IP6_DST_ME;
 528         } else if (F_LEN(cmd) ==
 529             (F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {
 530                 /* single IP, no mask*/
 531                 cmd->opcode = O_IP6_DST;
 532         } else {                                        /* addr/mask opt */
 533                 cmd->opcode = O_IP6_DST_MASK;
 534         }
 535         return cmd;
 536 }