/*

 *

 *   Authors:

 *    Lars Fenneberg    <lf@elemental.net>

 *

 *   This software is Copyright 1996,1997 by the above mentioned author(s),

 *   All Rights Reserved.

 *

 *   The license which is distributed with this software in the file COPYRIGHT

 *   applies to this software. If your distribution is missing this file, you

 *   may request it from <reubenhwk@gmail.com>.

 *

 */

#include "config.h"

#include "defaults.h"

#include "includes.h"

#include "pathnames.h"

#include "radvd.h"

int check_device(int sock, struct Interface *iface)

{

  struct ifreq ifr;

  memset(&ifr, 0, sizeof(ifr));

  strlcpy(ifr.ifr_name, iface->props.name, sizeof(ifr.ifr_name));

  if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {

    flog(LOG_ERR, "ioctl(SIOCGIFFLAGS) failed on %s: %s", iface->props.name, strerror(errno));

    return -1;

  } else {

    dlog(LOG_ERR, 5, "ioctl(SIOCGIFFLAGS) succeeded on %s", iface->props.name);

  }

  if (!(ifr.ifr_flags & IFF_UP)) {

    dlog(LOG_ERR, 4, "%s is not up", iface->props.name);

    return -1;

  } else {

    dlog(LOG_ERR, 4, "%s is up", iface->props.name);

  }

  if (!(ifr.ifr_flags & IFF_RUNNING)) {

    dlog(LOG_ERR, 4, "%s is not running", iface->props.name);

    return -1;

  } else {

    dlog(LOG_ERR, 4, "%s is running", iface->props.name);

  }

  if (!iface->UnicastOnly &&

      !(ifr.ifr_flags & (IFF_MULTICAST | IFF_POINTOPOINT))) {

    flog(LOG_INFO,

         "%s does not support multicast or point-to-point, forcing UnicastOnly",

         iface->props.name);

    iface->UnicastOnly = 1;

  } else {

    dlog(LOG_ERR, 4, "%s supports multicast or is point-to-point",

         iface->props.name);

  }

  return 0;

}

int get_v4addr(const char *ifn, unsigned int *dst)

{

  int fd = socket(AF_INET, SOCK_DGRAM, 0);

  if (fd < 0) {

    flog(LOG_ERR, "create socket for IPv4 ioctl failed on %s: %s", ifn, strerror(errno));

    return -1;

  }

  struct ifreq ifr;

  memset(&ifr, 0, sizeof(ifr));

  strlcpy(ifr.ifr_name, ifn, sizeof(ifr.ifr_name));

  ifr.ifr_addr.sa_family = AF_INET;

  if (ioctl(fd, SIOCGIFADDR, &ifr) < 0) {

    flog(LOG_ERR, "ioctl(SIOCGIFADDR) failed on %s: %s", ifn, strerror(errno));

    close(fd);

    return -1;

  }

  struct sockaddr_in *addr = (struct sockaddr_in *)(&ifr.ifr_addr);

  dlog(LOG_DEBUG, 3, "%s IPv4 address is: %s", ifn, inet_ntoa(addr->sin_addr));

  *dst = addr->sin_addr.s_addr;

  close(fd);

  return 0;

}

static int cmp_iface_addrs(void const *a, void const *b) { return memcmp(a, b, sizeof(struct in6_addr)); }

/*

 * Return first IPv6 link local addr in if_addr.

 * Return all the IPv6 addresses in if_addrs in ascending

 * order.

 * Return value is -1 if there was no link local addr.

 * otherwise return value is count of addres in if_addrs

 * not including the all zero (unspecified) addr at the

 * end of the list.

 */

int get_iface_addrs(char const *name, struct in6_addr *if_addr, struct in6_addr **if_addrs)

{

  struct ifaddrs *addresses = 0;

  int link_local_set = 0;

  int i = 0;

  if (getifaddrs(&addresses) != 0) {

    flog(LOG_ERR, "getifaddrs failed on %s: %s", name, strerror(errno));

  } else {

    for (struct ifaddrs *ifa = addresses; ifa != NULL; ifa = ifa->ifa_next) {

      if (!ifa->ifa_addr)

        continue;

      if (ifa->ifa_addr->sa_family != AF_INET6)

        continue;

      struct sockaddr_in6 *a6 = (struct sockaddr_in6 *)ifa->ifa_addr;

      /* Skip if it is not the interface we're looking for. */

      if (strcmp(ifa->ifa_name, name) != 0)

        continue;

      *if_addrs = realloc(*if_addrs, (i + 1) * sizeof(struct in6_addr));

      (*if_addrs)[i++] = a6->sin6_addr;

      /* Skip if it is not a linklocal address or link locak address already found*/

      uint8_t const ll_prefix[] = {0xfe, 0x80, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0};

      if (link_local_set || 0 != memcmp(&(a6->sin6_addr), ll_prefix, sizeof(ll_prefix)))

        continue;

      if (if_addr)

        memcpy(if_addr, &(a6->sin6_addr), sizeof(struct in6_addr));

      link_local_set = 1;

    }

  }

  if (addresses)

    freeifaddrs(addresses);

  /* last item in the list is all zero (unspecified) address */

  *if_addrs = realloc(*if_addrs, (i + 1) * sizeof(struct in6_addr));

  memset(&(*if_addrs)[i], 0, sizeof(struct in6_addr));

  /* Sort the addresses so the output is predictable. */

  qsort(*if_addrs, i, sizeof(struct in6_addr), cmp_iface_addrs);

  if (!link_local_set)

    return -1;

  return i;

}

/*

 * Saves the first link local address seen on the specified interface to iface->if_addr

 * and builds a list of all the other addrs.

 */

int setup_iface_addrs(struct Interface *iface)

{

  int rc = get_iface_addrs(iface->props.name, &iface->props.if_addr, &iface->props.if_addrs);

  if (-1 != rc) {

    iface->props.addrs_count = rc;

    char addr_str[INET6_ADDRSTRLEN];

    addrtostr(&iface->props.if_addr, addr_str, sizeof(addr_str));

    dlog(LOG_DEBUG, 4, "%s linklocal address: %s", iface->props.name, addr_str);

    for (int i = 0; i < rc; ++i) {

      addrtostr(&iface->props.if_addrs[i], addr_str, sizeof(addr_str));

      dlog(LOG_DEBUG, 4, "%s address: %s", iface->props.name, addr_str);

    }

    /* AdvRASrcAddress: allow operator selection of RA source address */

    if (iface->AdvRASrcAddressList != NULL) {

      iface->props.if_addr_rasrc = NULL;

      for (struct AdvRASrcAddress *current = iface->AdvRASrcAddressList; current; current = current->next) {

        for (int i = 0; i < iface->props.addrs_count; i++) {

          struct in6_addr cmp_addr = iface->props.if_addrs[i];

          if (0 == memcmp(&cmp_addr, &current->address, sizeof(struct in6_addr))) {

            addrtostr(&(cmp_addr), addr_str, sizeof(addr_str));

            dlog(LOG_DEBUG, 4, "AdvRASrcAddress selecting: %s", addr_str);

            iface->props.if_addr_rasrc = &iface->props.if_addrs[i];

            break;

          }

        }

        if (NULL != iface->props.if_addr_rasrc)

          break;

      }

    } else {

      /* AdvRASrcAddress default: Just take the first link-local */

      iface->props.if_addr_rasrc = &iface->props.if_addr;

    }

  } else {

    if (iface->IgnoreIfMissing)

      dlog(LOG_DEBUG, 4, "no linklocal address configured on %s", iface->props.name);

    else

      flog(LOG_ERR, "no linklocal address configured on %s", iface->props.name);

  }

  return rc;

}

int update_device_index(struct Interface *iface)

{

  int index = if_nametoindex(iface->props.name);

  if (0 == index) {

    /* Yes, if_nametoindex returns zero on failure.  2014/01/16 */

    flog(LOG_ERR, "%s not found: %s", iface->props.name, strerror(errno));

    return -1;

  }

  if (iface->props.if_index != index) {

    dlog(LOG_DEBUG, 4, "%s if_index changed from %d to %d", iface->props.name, iface->props.if_index, index);

    iface->props.if_index = index;

  }

  return 0;

}