/*

 * Copyright (c) 2002-2003 Luigi Rizzo

 * Copyright (c) 1996 Alex Nash, Paul Traina, Poul-Henning Kamp

 * Copyright (c) 1994 Ugen J.S.Antsilevich

 *

 * Idea and grammar partially left from:

 * Copyright (c) 1993 Daniel Boulet

 *

 * Redistribution and use in source forms, with and without modification,

 * are permitted provided that this entire comment appears intact.

 *

 * Redistribution in binary form may occur without any restrictions.

 * Obviously, it would be nice if you gave credit where credit is due

 * but requiring it would be too onerous.

 *

 * This software is provided ``AS IS'' without any warranties of any kind.

 *

 * NEW command line interface for IP firewall facility

 *

 * $FreeBSD: head/sbin/ipfw/ipv6.c 270424 2014-08-23 17:37:18Z melifaro $

 *

 * ipv6 support

 */

#include <sys/types.h>

#include <sys/socket.h>

#include "ipfw2.h"

#include <err.h>

#include <netdb.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sysexits.h>

#include <net/if.h>

#include <netinet/in.h>

#include <netinet/in_systm.h>

#include <netinet/ip.h>

#include <netinet/icmp6.h>

#include <netinet/ip_fw.h>

#include <arpa/inet.h>

#define CHECK_LENGTH(v, len) do {     \

  if ((v) < (len))       \

    errx(EX_DATAERR, "Rule too long"); \

  } while (0)

static struct _s_x icmp6codes[] = {

      { "no-route",   ICMP6_DST_UNREACH_NOROUTE },

      { "admin-prohib",   ICMP6_DST_UNREACH_ADMIN },

      { "address",    ICMP6_DST_UNREACH_ADDR },

      { "port",     ICMP6_DST_UNREACH_NOPORT },

      { NULL, 0 }

};

void

fill_unreach6_code(u_short *codep, char *str)

{

  int val;

  char *s;

  val = strtoul(str, &s, 0);

  if (s == str || *s != '\0' || val >= 0x100)

    val = match_token(icmp6codes, str);

  if (val < 0)

    errx(EX_DATAERR, "unknown ICMPv6 unreachable code ``%s''", str);

  *codep = val;

  return;

}

void

print_unreach6_code(uint16_t code)

{

  char const *s = match_value(icmp6codes, code);

  if (s != NULL)

    printf("unreach6 %s", s);

  else

    printf("unreach6 %u", code);

}

/*

 * Print the ip address contained in a command.

 */

void

print_ip6(struct buf_pr *bp, ipfw_insn_ip6 *cmd, char const *s)

{

       struct hostent *he = NULL;

       int len = F_LEN((ipfw_insn *) cmd) - 1;

       struct in6_addr *a = &(cmd->addr6);

       char trad[255];

       bprintf(bp, "%s%s ", cmd->o.len & F_NOT ? " not": "", s);

       if (cmd->o.opcode == O_IP6_SRC_ME || cmd->o.opcode == O_IP6_DST_ME) {

         bprintf(bp, "me6");

         return;

       }

       if (cmd->o.opcode == O_IP6) {

         bprintf(bp, " ip6");

         return;

       }

       /*

  * len == 4 indicates a single IP, whereas lists of 1 or more

  * addr/mask pairs have len = (2n+1). We convert len to n so we

  * use that to count the number of entries.

  */

       for (len = len / 4; len > 0; len -= 2, a += 2) {

     int mb = /* mask length */

         (cmd->o.opcode == O_IP6_SRC || cmd->o.opcode == O_IP6_DST) ?

         128 : contigmask((uint8_t *)&(a[1]), 128);

     if (mb == 128 && co.do_resolv)

         he = gethostbyaddr((char *)a, sizeof(*a), AF_INET6);

     if (he != NULL)      /* resolved to name */

         bprintf(bp, "%s", he->h_name);

     else if (mb == 0)    /* any */

         bprintf(bp, "any");

     else {   /* numeric IP followed by some kind of mask */

         if (inet_ntop(AF_INET6,  a, trad, sizeof( trad ) ) == NULL)

       bprintf(bp, "Error ntop in print_ip6\n");

         bprintf(bp, "%s",  trad );

         if (mb < 0)     /* XXX not really legal... */

       bprintf(bp, ":%s",

           inet_ntop(AF_INET6, &a[1], trad, sizeof(trad)));

         else if (mb < 128)

       bprintf(bp, "/%d", mb);

     }

     if (len > 2)

         bprintf(bp, ",");

       }

}

void

fill_icmp6types(ipfw_insn_icmp6 *cmd, char *av, int cblen)

{

       uint8_t type;

       CHECK_LENGTH(cblen, F_INSN_SIZE(ipfw_insn_icmp6));

       bzero(cmd, sizeof(*cmd));

       while (*av) {

     if (*av == ',')

         av++;

     type = strtoul(av, &av, 0);

     if (*av != ',' && *av != '\0')

         errx(EX_DATAERR, "invalid ICMP6 type");

     /*

      * XXX: shouldn't this be 0xFF?  I can't see any reason why

      * we shouldn't be able to filter all possiable values

      * regardless of the ability of the rest of the kernel to do

      * anything useful with them.

      */

     if (type > ICMP6_MAXTYPE)

         errx(EX_DATAERR, "ICMP6 type out of range");

     cmd->d[type / 32] |= ( 1 << (type % 32));

       }

       cmd->o.opcode = O_ICMP6TYPE;

       cmd->o.len |= F_INSN_SIZE(ipfw_insn_icmp6);

}

void

print_icmp6types(struct buf_pr *bp, ipfw_insn_u32 *cmd)

{

       int i, j;

       char sep= ' ';

       bprintf(bp, " ip6 icmp6types");

       for (i = 0; i < 7; i++)

         for (j=0; j < 32; ++j) {

           if ( (cmd->d[i] & (1 << (j))) == 0)

             continue;

           bprintf(bp, "%c%d", sep, (i*32 + j));

           sep = ',';

         }

}

void

print_flow6id(struct buf_pr *bp, ipfw_insn_u32 *cmd)

{

       uint16_t i, limit = cmd->o.arg1;

       char sep = ',';

       bprintf(bp, " flow-id ");

       for( i=0; i < limit; ++i) {

         if (i == limit - 1)

           sep = ' ';

         bprintf(bp, "%d%c", cmd->d[i], sep);

       }

}

/* structure and define for the extension header in ipv6 */

static struct _s_x ext6hdrcodes[] = {

       { "frag",       EXT_FRAGMENT },

       { "hopopt",     EXT_HOPOPTS },

       { "route",      EXT_ROUTING },

       { "dstopt",     EXT_DSTOPTS },

       { "ah",   EXT_AH },

       { "esp", EXT_ESP },

       { "rthdr0",     EXT_RTHDR0 },

       { "rthdr2",     EXT_RTHDR2 },

       { NULL,   0 }

};

/* fills command for the extension header filtering */

int

fill_ext6hdr( ipfw_insn *cmd, char *av)

{

       int tok;

       char *s = av;

       cmd->arg1 = 0;

       while(s) {

     av = strsep( &s, ",") ;

     tok = match_token(ext6hdrcodes, av);

     switch (tok) {

     case EXT_FRAGMENT:

         cmd->arg1 |= EXT_FRAGMENT;

         break;

     case EXT_HOPOPTS:

         cmd->arg1 |= EXT_HOPOPTS;

         break;

     case EXT_ROUTING:

         cmd->arg1 |= EXT_ROUTING;

         break;

     case EXT_DSTOPTS:

         cmd->arg1 |= EXT_DSTOPTS;

         break;

     case EXT_AH:

         cmd->arg1 |= EXT_AH;

         break;

     case EXT_ESP:

         cmd->arg1 |= EXT_ESP;

         break;

     case EXT_RTHDR0:

         cmd->arg1 |= EXT_RTHDR0;

         break;

     case EXT_RTHDR2:

         cmd->arg1 |= EXT_RTHDR2;

         break;

     default:

         errx( EX_DATAERR, "invalid option for ipv6 exten header" );

         break;

     }

       }

       if (cmd->arg1 == 0 )

     return 0;

       cmd->opcode = O_EXT_HDR;

       cmd->len |= F_INSN_SIZE( ipfw_insn );

       return 1;

}

void

print_ext6hdr(struct buf_pr *bp, ipfw_insn *cmd )

{

       char sep = ' ';

       bprintf(bp, " extension header:");

       if (cmd->arg1 & EXT_FRAGMENT ) {

     bprintf(bp, "%cfragmentation", sep);

     sep = ',';

       }

       if (cmd->arg1 & EXT_HOPOPTS ) {

     bprintf(bp, "%chop options", sep);

     sep = ',';

       }

       if (cmd->arg1 & EXT_ROUTING ) {

     bprintf(bp, "%crouting options", sep);

     sep = ',';

       }

       if (cmd->arg1 & EXT_RTHDR0 ) {

     bprintf(bp, "%crthdr0", sep);

     sep = ',';

       }

       if (cmd->arg1 & EXT_RTHDR2 ) {

     bprintf(bp, "%crthdr2", sep);

     sep = ',';

       }

       if (cmd->arg1 & EXT_DSTOPTS ) {

     bprintf(bp, "%cdestination options", sep);

     sep = ',';

       }

       if (cmd->arg1 & EXT_AH ) {

     bprintf(bp, "%cauthentication header", sep);

     sep = ',';

       }

       if (cmd->arg1 & EXT_ESP ) {

     bprintf(bp, "%cencapsulated security payload", sep);

       }

}

/* Try to find ipv6 address by hostname */

static int

lookup_host6 (char *host, struct in6_addr *ip6addr)

{

  struct hostent *he;

  if (!inet_pton(AF_INET6, host, ip6addr)) {

    if ((he = gethostbyname2(host, AF_INET6)) == NULL)

      return(-1);

    memcpy(ip6addr, he->h_addr_list[0], sizeof( struct in6_addr));

  }

  return(0);

}

/*

 * fill the addr and mask fields in the instruction as appropriate from av.

 * Update length as appropriate.

 * The following formats are allowed:

 *     any     matches any IP6. Actually returns an empty instruction.

 *     me      returns O_IP6_*_ME

 *

 *     03f1::234:123:0342   single IP6 addres

 *     03f1::234:123:0342/24      address/mask

 *     03f1::234:123:0342/24,03f1::234:123:0343/         List of address

 *

 * Set of address (as in ipv6) not supported because ipv6 address

 * are typically random past the initial prefix.

 * Return 1 on success, 0 on failure.

 */

static int

fill_ip6(ipfw_insn_ip6 *cmd, char *av, int cblen)

{

  int len = 0;

  struct in6_addr *d = &(cmd->addr6);

  char *av1;

  /*

   * Needed for multiple address.

   * Note d[1] points to struct in6_add r mask6 of cmd

   */

  cmd->o.len &= ~F_LEN_MASK; /* zero len */

  if (strcmp(av, "any") == 0)

    return (1);

  if (strcmp(av, "me") == 0) { /* Set the data for "me" opt*/

    cmd->o.len |= F_INSN_SIZE(ipfw_insn);

    return (1);

  }

  if (strcmp(av, "me6") == 0) { /* Set the data for "me" opt*/

    cmd->o.len |= F_INSN_SIZE(ipfw_insn);

    return (1);

  }

  if (strncmp(av, "table(", 6) == 0) {

    char *p = strchr(av + 6, ',');

    uint32_t *dm = ((ipfw_insn_u32 *)cmd)->d;

    if (p)

      *p++ = '\0';

    cmd->o.opcode = O_IP_DST_LOOKUP;

    cmd->o.arg1 = strtoul(av + 6, NULL, 0);

    if (p) {

      cmd->o.len |= F_INSN_SIZE(ipfw_insn_u32);

      dm[0] = strtoul(p, NULL, 0);

    } else

      cmd->o.len |= F_INSN_SIZE(ipfw_insn);

    return (1);

  }

  av1 = av = strdup(av);

  while (av) {

    /*

     * After the address we can have '/' indicating a mask,

     * or ',' indicating another address follows.

     */

    char *p;

    int masklen;

    char md = '\0';

    CHECK_LENGTH(cblen, 1 + len + 2 * F_INSN_SIZE(struct in6_addr));

    if ((p = strpbrk(av, "/,")) ) {

      md = *p;  /* save the separator */

      *p = '\0';  /* terminate address string */

      p++;    /* and skip past it */

    }

    /* now p points to NULL, mask or next entry */

    /* lookup stores address in *d as a side effect */

    if (lookup_host6(av, d) != 0) {

      /* XXX: failed. Free memory and go */

      errx(EX_DATAERR, "bad address \"%s\"", av);

    }

    /* next, look at the mask, if any */

    masklen = (md == '/') ? atoi(p) : 128;

    if (masklen > 128 || masklen < 0)

      errx(EX_DATAERR, "bad width \"%s\''", p);

    else

      n2mask(&d[1], masklen);

    APPLY_MASK(d, &d[1])   /* mask base address with mask */

    /* find next separator */

    if (md == '/') { /* find separator past the mask */

      p = strpbrk(p, ",");

      if (p != NULL)

        p++;

    }

    av = p;

    /* Check this entry */

    if (masklen == 0) {

      /*

       * 'any' turns the entire list into a NOP.

       * 'not any' never matches, so it is removed from the

       * list unless it is the only item, in which case we

       * report an error.

       */

      if (cmd->o.len & F_NOT && av == NULL && len == 0)

        errx(EX_DATAERR, "not any never matches");

      continue;

    }

    /*

     * A single IP can be stored alone

     */

    if (masklen == 128 && av == NULL && len == 0) {

      len = F_INSN_SIZE(struct in6_addr);

      break;

    }

    /* Update length and pointer to arguments */

    len += F_INSN_SIZE(struct in6_addr)*2;

    d += 2;

  } /* end while */

  /*

   * Total length of the command, remember that 1 is the size of

   * the base command.

   */

  if (len + 1 > F_LEN_MASK)

    errx(EX_DATAERR, "address list too long");

  cmd->o.len |= len+1;

  free(av1);

  return (1);

}

/*

 * fills command for ipv6 flow-id filtering

 * note that the 20 bit flow number is stored in a array of u_int32_t

 * it's supported lists of flow-id, so in the o.arg1 we store how many

 * additional flow-id we want to filter, the basic is 1

 */

void

fill_flow6( ipfw_insn_u32 *cmd, char *av, int cblen)

{

  u_int32_t type;  /* Current flow number */

  u_int16_t nflow = 0;    /* Current flow index */

  char *s = av;

  cmd->d[0] = 0;    /* Initializing the base number*/

  while (s) {

    CHECK_LENGTH(cblen, F_INSN_SIZE(ipfw_insn_u32) + nflow + 1);

    av = strsep( &s, ",") ;

    type = strtoul(av, &av, 0);

    if (*av != ',' && *av != '\0')

      errx(EX_DATAERR, "invalid ipv6 flow number %s", av);

    if (type > 0xfffff)

      errx(EX_DATAERR, "flow number out of range %s", av);

    cmd->d[nflow] |= type;

    nflow++;

  }

  if( nflow > 0 ) {

    cmd->o.opcode = O_FLOW6ID;

    cmd->o.len |= F_INSN_SIZE(ipfw_insn_u32) + nflow;

    cmd->o.arg1 = nflow;

  }

  else {

    errx(EX_DATAERR, "invalid ipv6 flow number %s", av);

  }

}

ipfw_insn *

add_srcip6(ipfw_insn *cmd, char *av, int cblen)

{

  fill_ip6((ipfw_insn_ip6 *)cmd, av, cblen);

  if (cmd->opcode == O_IP_DST_SET)      /* set */

    cmd->opcode = O_IP_SRC_SET;

  else if (cmd->opcode == O_IP_DST_LOOKUP)    /* table */

    cmd->opcode = O_IP_SRC_LOOKUP;

  else if (F_LEN(cmd) == 0) {       /* any */

  } else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) { /* "me" */

    cmd->opcode = O_IP6_SRC_ME;

  } else if (F_LEN(cmd) ==

      (F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {

    /* single IP, no mask*/

    cmd->opcode = O_IP6_SRC;

  } else {         /* addr/mask opt */

    cmd->opcode = O_IP6_SRC_MASK;

  }

  return cmd;

}

ipfw_insn *

add_dstip6(ipfw_insn *cmd, char *av, int cblen)

{

  fill_ip6((ipfw_insn_ip6 *)cmd, av, cblen);

  if (cmd->opcode == O_IP_DST_SET)      /* set */

    ;

  else if (cmd->opcode == O_IP_DST_LOOKUP)    /* table */

    ;

  else if (F_LEN(cmd) == 0) {       /* any */

  } else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) { /* "me" */

    cmd->opcode = O_IP6_DST_ME;

  } else if (F_LEN(cmd) ==

      (F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {

    /* single IP, no mask*/

    cmd->opcode = O_IP6_DST;

  } else {         /* addr/mask opt */

    cmd->opcode = O_IP6_DST_MASK;

  }

  return cmd;

}