/* 

   Unix SMB/CIFS implementation.

   multiple interface handling

   Copyright (C) Andrew Tridgell 1992-2005

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "includes.h"

#include "system/network.h"

#include "param/param.h"

#include "lib/socket/netif.h"

#include "../lib/util/util_net.h"

#include "../lib/util/dlinklist.h"

#include "lib/util/smb_strtox.h"

/* used for network interfaces */

struct interface {

  struct interface *next, *prev;

  char *name;

  int flags;

  struct sockaddr_storage ip;

  struct sockaddr_storage netmask;

  struct sockaddr_storage bcast;

  const char *ip_s;

  const char *bcast_s;

  const char *nmask_s;

};

#define ALLONES  ((uint32_t)0xFFFFFFFF)

/*

  address construction based on a patch from fred@datalync.com

*/

#define MKBCADDR(_IP, _NM) ((_IP & _NM) | (_NM ^ ALLONES))

#define MKNETADDR(_IP, _NM) (_IP & _NM)

/****************************************************************************

Try and find an interface that matches an ip. If we cannot, return NULL

  **************************************************************************/

static struct interface *iface_list_find(struct interface *interfaces,

           const struct sockaddr *ip,

           bool check_mask)

{

  struct interface *i;

  if (is_address_any(ip)) {

    return interfaces;

  }

  for (i=interfaces;i;i=i->next) {

    if (check_mask) {

      if (same_net(ip, (struct sockaddr *)&i->ip, (struct sockaddr *)&i->netmask)) {

        return i;

      }

    } else if (sockaddr_equal((struct sockaddr *)&i->ip, ip)) {

      return i;

    }

  }

  return NULL;

}

/****************************************************************************

add an interface to the linked list of interfaces

****************************************************************************/

static void add_interface(TALLOC_CTX *mem_ctx, const struct iface_struct *ifs, struct interface **interfaces)

{

  char addr[INET6_ADDRSTRLEN];

  struct interface *iface;

  if (iface_list_find(*interfaces, (const struct sockaddr *)&ifs->ip, false)) {

    DEBUG(3,("add_interface: not adding duplicate interface %s\n",

      print_sockaddr(addr, sizeof(addr), &ifs->ip) ));

    return;

  }

  if (ifs->ip.ss_family == AF_INET &&

    !(ifs->flags & (IFF_BROADCAST|IFF_LOOPBACK))) {

    DEBUG(3,("not adding non-broadcast interface %s\n",

          ifs->name ));

    return;

  }

  if (*interfaces != NULL) {

    mem_ctx = *interfaces;

  }

  iface = talloc_zero(mem_ctx, struct interface);

  if (iface == NULL) {

    return;

  }

  iface->name = talloc_strdup(iface, ifs->name);

  if (!iface->name) {

    SAFE_FREE(iface);

    return;

  }

  iface->flags = ifs->flags;

  iface->ip = ifs->ip;

  iface->netmask = ifs->netmask;

  iface->bcast = ifs->bcast;

  /* keep string versions too, to avoid people tripping over the implied

     static in inet_ntoa() */

  print_sockaddr(addr, sizeof(addr), &iface->ip);

  DEBUG(4,("added interface %s ip=%s ",

     iface->name, addr));

  iface->ip_s = talloc_strdup(iface, addr);

  print_sockaddr(addr, sizeof(addr),

           &iface->bcast);

  DEBUG(4,("bcast=%s ", addr));

  iface->bcast_s = talloc_strdup(iface, addr);

  print_sockaddr(addr, sizeof(addr),

           &iface->netmask);

  DEBUG(4,("netmask=%s\n", addr));

  iface->nmask_s = talloc_strdup(iface, addr);

  /*

     this needs to be a ADD_END, as some tests (such as the

     spoolss notify test) depend on the interfaces ordering

  */

  DLIST_ADD_END(*interfaces, iface);

}

/**

interpret a single element from a interfaces= config line 

This handles the following different forms:

1) wildcard interface name

2) DNS name

3) IP/masklen

4) ip/mask

5) bcast/mask

**/

static void interpret_interface(TALLOC_CTX *mem_ctx, 

        const char *token, 

        struct iface_struct *probed_ifaces, 

        int total_probed,

        struct interface **local_interfaces)

{

  struct sockaddr_storage ss;

  struct sockaddr_storage ss_mask;

  struct sockaddr_storage ss_net;

  struct sockaddr_storage ss_bcast;

  struct iface_struct ifs;

  char *p;

  int i;

  bool added=false;

  bool goodaddr = false;

  /* first check if it is an interface name */

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

    if (gen_fnmatch(token, probed_ifaces[i].name) == 0) {

      add_interface(mem_ctx, &probed_ifaces[i],

              local_interfaces);

      added = true;

    }

  }

  if (added) {

    return;

  }

  p = discard_const_p(char, strchr_m(token, ';'));

  if (p != NULL) {

    /*

     * skip smbd-specific extra data:

     * link speed, capabilities, and interface index

     */

    *p = 0;

  }

  /* maybe it is a DNS name */

  p = discard_const_p(char, strchr_m(token, '/'));

  if (p == NULL) {

    if (!interpret_string_addr(&ss, token, 0)) {

      DEBUG(2, ("interpret_interface: Can't find address "

          "for %s\n", token));

      return;

    }

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

      if (sockaddr_equal((struct sockaddr *)&ss, (struct sockaddr *)&probed_ifaces[i].ip)) {

        add_interface(mem_ctx, &probed_ifaces[i],

                local_interfaces);

        return;

      }

    }

    DEBUG(2,("interpret_interface: "

      "can't determine interface for %s\n",

      token));

    return;

  }

  /* parse it into an IP address/netmasklength pair */

  *p = 0;

  goodaddr = interpret_string_addr(&ss, token, 0);

  *p++ = '/';

  if (!goodaddr) {

    DEBUG(2,("interpret_interface: "

      "can't determine interface for %s\n",

      token));

    return;

  }

  if (strlen(p) > 2) {

    goodaddr = interpret_string_addr(&ss_mask, p, 0);

    if (!goodaddr) {

      DEBUG(2,("interpret_interface: "

        "can't determine netmask from %s\n",

        p));

      return;

    }

  } else {

    int error = 0;

    unsigned long val = smb_strtoul(p,

            NULL,

            0,

            &error,

            SMB_STR_FULL_STR_CONV);

    if (error != 0) {

      DEBUG(2,("interpret_interface: "

        "can't determine netmask value from %s\n",

        p));

      return;

    }

    if (!make_netmask(&ss_mask, &ss, val)) {

      DEBUG(2,("interpret_interface: "

        "can't apply netmask value %lu from %s\n",

        val,

        p));

      return;

    }

  }

  make_bcast(&ss_bcast, &ss, &ss_mask);

  make_net(&ss_net, &ss, &ss_mask);

  /* Maybe the first component was a broadcast address. */

  if (sockaddr_equal((struct sockaddr *)&ss_bcast, (struct sockaddr *)&ss) ||

    sockaddr_equal((struct sockaddr *)&ss_net, (struct sockaddr *)&ss)) {

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

      if (same_net((struct sockaddr *)&ss,

             (struct sockaddr *)&probed_ifaces[i].ip,

             (struct sockaddr *)&ss_mask)) {

        /* Temporarily replace netmask on

         * the detected interface - user knows

         * best.... */

        struct sockaddr_storage saved_mask =

          probed_ifaces[i].netmask;

        probed_ifaces[i].netmask = ss_mask;

        DEBUG(2,("interpret_interface: "

          "using netmask value %s from "

          "config file on interface %s\n",

          p,

          probed_ifaces[i].name));

        add_interface(mem_ctx, &probed_ifaces[i],

                local_interfaces);

        probed_ifaces[i].netmask = saved_mask;

        return;

      }

    }

    DEBUG(2,("interpret_interface: Can't determine ip for "

      "broadcast address %s\n",

      token));

    return;

  }

  /* Just fake up the interface definition. User knows best. */

  DEBUG(2,("interpret_interface: Adding interface %s\n",

    token));

  ZERO_STRUCT(ifs);

  (void)strlcpy(ifs.name, token, sizeof(ifs.name));

  ifs.flags = IFF_BROADCAST;

  ifs.ip = ss;

  ifs.netmask = ss_mask;

  ifs.bcast = ss_bcast;

  add_interface(mem_ctx, &ifs, local_interfaces);

}

/**

load the list of network interfaces

**/

void load_interface_list(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx, struct interface **local_interfaces)

{

  const char **ptr = lpcfg_interfaces(lp_ctx);

  int i;

  struct iface_struct *ifaces = NULL;

  int total_probed;

  *local_interfaces = NULL;

  /* probe the kernel for interfaces */

  total_probed = get_interfaces(mem_ctx, &ifaces);

  /* if we don't have a interfaces line then use all interfaces

     except loopback */

  if (!ptr || !*ptr || !**ptr) {

    if (total_probed <= 0) {

      DEBUG(0,("ERROR: Could not determine network interfaces, you must use a interfaces config line\n"));

    }

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

      if (!is_loopback_addr((struct sockaddr *)&ifaces[i].ip)) {

        add_interface(mem_ctx, &ifaces[i], local_interfaces);

      }

    }

  }

  while (ptr && *ptr) {

    interpret_interface(mem_ctx, *ptr, ifaces, total_probed, local_interfaces);

    ptr++;

  }

  if (*local_interfaces == NULL) {

    const char **first_ptr = lpcfg_interfaces(lp_ctx);

    if (first_ptr != NULL && *first_ptr != NULL) {

      DBG_ERR("None of the interfaces listed in smb.conf "

        "'interfaces = ...' seem to exist\n");

    }

    DBG_ERR("WARNING: no network interfaces found\n");

  }

  talloc_free(ifaces);

}

/**

  how many interfaces do we have

  **/

int iface_list_count(struct interface *ifaces)

{

  int ret = 0;

  struct interface *i;

  for (i=ifaces;i;i=i->next)

    ret++;

  return ret;

}

/**

  return IP of the Nth interface

  **/

const char *iface_list_n_ip(struct interface *ifaces, int n)

{

  struct interface *i;

  for (i=ifaces;i && n;i=i->next)

    n--;

  if (i) {

    return i->ip_s;

  }

  return NULL;

}

/**

  return the first IPv4 interface address we have registered

  **/

const char *iface_list_first_v4(struct interface *ifaces)

{

  struct interface *i;

  for (i=ifaces; i; i=i->next) {

    if (i->ip.ss_family == AF_INET) {

      return i->ip_s;

    }

  }

  return NULL;

}

/**

  return the first IPv6 interface address we have registered

  **/

static const char *iface_list_first_v6(struct interface *ifaces)

{

  struct interface *i;

#ifdef HAVE_IPV6

  for (i=ifaces; i; i=i->next) {

    if (i->ip.ss_family == AF_INET6) {

      return i->ip_s;

    }

  }

#endif

  return NULL;

}

/**

   check if an interface is IPv4

  **/

bool iface_list_n_is_v4(struct interface *ifaces, int n)

{

  struct interface *i;

  for (i=ifaces;i && n;i=i->next)

    n--;

  if (i) {

    return i->ip.ss_family == AF_INET;

  }

  return false;

}

/**

  return bcast of the Nth interface

  **/

const char *iface_list_n_bcast(struct interface *ifaces, int n)

{

  struct interface *i;

  for (i=ifaces;i && n;i=i->next)

    n--;

  if (i) {

    return i->bcast_s;

  }

  return NULL;

}

/**

  return netmask of the Nth interface

  **/

const char *iface_list_n_netmask(struct interface *ifaces, int n)

{

  struct interface *i;

  for (i=ifaces;i && n;i=i->next)

    n--;

  if (i) {

    return i->nmask_s;

  }

  return NULL;

}

/**

  return the local IP address that best matches a destination IP, or

  our first interface if none match

*/

const char *iface_list_best_ip(struct interface *ifaces, const char *dest)

{

  struct interface *iface;

  struct sockaddr_storage ss;

  if (!interpret_string_addr(&ss, dest, AI_NUMERICHOST)) {

    return iface_list_n_ip(ifaces, 0);

  }

  iface = iface_list_find(ifaces, (const struct sockaddr *)&ss, true);

  if (iface) {

    return iface->ip_s;

  }

#ifdef HAVE_IPV6

  if (ss.ss_family == AF_INET6) {

    return iface_list_first_v6(ifaces);

  }

#endif

  return iface_list_first_v4(ifaces);

}

/**

  return true if an IP is one one of our local networks

*/

bool iface_list_is_local(struct interface *ifaces, const char *dest)

{

  struct sockaddr_storage ss;

  if (!interpret_string_addr(&ss, dest, AI_NUMERICHOST)) {

    return false;

  }

  if (iface_list_find(ifaces, (const struct sockaddr *)&ss, true)) {

    return true;

  }

  return false;

}

/**

  return true if a IP matches a IP/netmask pair

*/

bool iface_list_same_net(const char *ip1, const char *ip2, const char *netmask)

{

  struct sockaddr_storage ip1_ss, ip2_ss, nm_ss;

  if (!interpret_string_addr(&ip1_ss, ip1, AI_NUMERICHOST)) {

    return false;

  }

  if (!interpret_string_addr(&ip2_ss, ip2, AI_NUMERICHOST)) {

    return false;

  }

  if (!interpret_string_addr(&nm_ss, netmask, AI_NUMERICHOST)) {

    return false;

  }

  return same_net((struct sockaddr *)&ip1_ss,

      (struct sockaddr *)&ip2_ss,

      (struct sockaddr *)&nm_ss);

}

/**

   return the list of wildcard interfaces

   this will include the IPv4 0.0.0.0, and may include IPv6 ::

*/

char **iface_list_wildcard(TALLOC_CTX *mem_ctx)

{

  char **ret;

#ifdef HAVE_IPV6

  ret = str_list_make(mem_ctx, "::,0.0.0.0", NULL);

#else

  ret = str_list_make(mem_ctx, "0.0.0.0", NULL);

#endif

  return ret;

}