/*

 * SPDX-License-Identifier: ISC

 *

 * Copyright (c) 1996, 1998-2005, 2007-2015

 *  Todd C. Miller <Todd.Miller@sudo.ws>

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 *

 * Sponsored in part by the Defense Advanced Research Projects

 * Agency (DARPA) and Air Force Research Laboratory, Air Force

 * Materiel Command, USAF, under agreement number F39502-99-1-0512.

 */

/*

 * This is an open source non-commercial project. Dear PVS-Studio, please check it.

 * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com

 */

#include <config.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#ifdef NEED_RESOLV_H

# include <arpa/nameser.h>

# include <resolv.h>

#endif /* NEED_RESOLV_H */

#include <sudoers.h>

#include <interfaces.h>

static int

addr_matches_if(const char *n)

{

    union sudo_in_addr_un addr;

    struct interface *ifp;

#ifdef HAVE_STRUCT_IN6_ADDR

    size_t j;

#endif

    unsigned int family;

    debug_decl(addr_matches_if, SUDOERS_DEBUG_MATCH);

#ifdef HAVE_STRUCT_IN6_ADDR

    if (inet_pton(AF_INET6, n, &addr.ip6) == 1) {

  family = AF_INET6;

    } else

#endif /* HAVE_STRUCT_IN6_ADDR */

    if (inet_pton(AF_INET, n, &addr.ip4) == 1) {

  family = AF_INET;

    } else {

  debug_return_int(DENY);

    }

    SLIST_FOREACH(ifp, get_interfaces(), entries) {

  if (ifp->family != family)

      continue;

  switch (family) {

      case AF_INET:

    if (ifp->addr.ip4.s_addr == addr.ip4.s_addr ||

        (ifp->addr.ip4.s_addr & ifp->netmask.ip4.s_addr)

        == addr.ip4.s_addr)

        debug_return_int(ALLOW);

    break;

#ifdef HAVE_STRUCT_IN6_ADDR

      case AF_INET6:

    if (memcmp(ifp->addr.ip6.s6_addr, addr.ip6.s6_addr,

        sizeof(addr.ip6.s6_addr)) == 0)

        debug_return_int(ALLOW);

    for (j = 0; j < sizeof(addr.ip6.s6_addr); j++) {

        if ((ifp->addr.ip6.s6_addr[j] & ifp->netmask.ip6.s6_addr[j]) != addr.ip6.s6_addr[j])

      break;

    }

    if (j == sizeof(addr.ip6.s6_addr))

        debug_return_int(ALLOW);

    break;

#endif /* HAVE_STRUCT_IN6_ADDR */

  }

    }

    debug_return_int(DENY);

}

static int

addr_matches_if_netmask(const char *n, const char *m)

{

    size_t i;

    union sudo_in_addr_un addr, mask;

    struct interface *ifp;

#ifdef HAVE_STRUCT_IN6_ADDR

    size_t j;

#endif

    unsigned int family;

    const char *errstr;

    debug_decl(addr_matches_if, SUDOERS_DEBUG_MATCH);

#ifdef HAVE_STRUCT_IN6_ADDR

    if (inet_pton(AF_INET6, n, &addr.ip6) == 1)

  family = AF_INET6;

    else

#endif /* HAVE_STRUCT_IN6_ADDR */

    if (inet_pton(AF_INET, n, &addr.ip4) == 1) {

  family = AF_INET;

    } else {

  debug_return_int(DENY);

    }

    if (family == AF_INET) {

  if (strchr(m, '.')) {

      if (inet_pton(AF_INET, m, &mask.ip4) != 1) {

    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

        "IPv4 netmask %s: %s", m, "invalid value");

    debug_return_int(DENY);

      }

  } else {

      i = (size_t)sudo_strtonum(m, 1, 32, &errstr);

      if (errstr != NULL) {

    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

        "IPv4 netmask %s: %s", m, errstr);

    debug_return_int(DENY);

      }

      mask.ip4.s_addr = htonl(0xffffffffU << (32 - i));

  }

  addr.ip4.s_addr &= mask.ip4.s_addr;

    }

#ifdef HAVE_STRUCT_IN6_ADDR

    else {

  if (inet_pton(AF_INET6, m, &mask.ip6) != 1) {

      j = (size_t)sudo_strtonum(m, 1, 128, &errstr);

      if (errstr != NULL) {

    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

        "IPv6 netmask %s: %s", m, errstr);

    debug_return_int(DENY);

      }

      for (i = 0; i < sizeof(addr.ip6.s6_addr); i++) {

    if (j < i * 8)

        mask.ip6.s6_addr[i] = 0;

    else if (i * 8 + 8 <= j)

        mask.ip6.s6_addr[i] = 0xff;

    else

        mask.ip6.s6_addr[i] = 0xff00 >> (j - i * 8);

    addr.ip6.s6_addr[i] &= mask.ip6.s6_addr[i];

      }

  }

    }

#endif /* HAVE_STRUCT_IN6_ADDR */

    SLIST_FOREACH(ifp, get_interfaces(), entries) {

  if (ifp->family != family)

      continue;

  switch (family) {

      case AF_INET:

    if ((ifp->addr.ip4.s_addr & mask.ip4.s_addr) == addr.ip4.s_addr)

        debug_return_int(ALLOW);

    break;

#ifdef HAVE_STRUCT_IN6_ADDR

      case AF_INET6:

    for (j = 0; j < sizeof(addr.ip6.s6_addr); j++) {

        if ((ifp->addr.ip6.s6_addr[j] & mask.ip6.s6_addr[j]) != addr.ip6.s6_addr[j])

      break;

    }

    if (j == sizeof(addr.ip6.s6_addr))

        debug_return_int(ALLOW);

    break;

#endif /* HAVE_STRUCT_IN6_ADDR */

  }

    }

    debug_return_int(DENY);

}

/*

 * Returns ALLOW if "n" is one of our ip addresses or if

 * "n" is a network that we are on, else returns DENY.

 */

int

addr_matches(char *n)

{

    char *m;

    int ret;

    debug_decl(addr_matches, SUDOERS_DEBUG_MATCH);

    /* If there's an explicit netmask, use it. */

    if ((m = strchr(n, '/'))) {

  *m++ = '\0';

  ret = addr_matches_if_netmask(n, m);

  *(m - 1) = '/';

    } else

  ret = addr_matches_if(n);

    sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO,

  "IP address %s matches local host: %s", n,

  ret == ALLOW ? "ALLOW" : "DENY");

    debug_return_int(ret);

}