/*

 * Copyright (C) 2004, 2005, 2007, 2008, 2012  Internet Systems Consortium, Inc. ("ISC")

 * Copyright (C) 1999-2003  Internet Software Consortium.

 *

 * Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH

 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY

 * AND FITNESS.  IN NO EVENT SHALL ISC 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.

 */

/* $Id$ */

#include <config.h>

#include <sys/types.h>

#if defined(HAVE_SYS_SYSCTL_H)

#if defined(HAVE_SYS_PARAM_H)

#include <sys/param.h>

#endif

#include <sys/sysctl.h>

#endif

#include <errno.h>

#include <unistd.h>

#include <isc/log.h>

#include <isc/msgs.h>

#include <isc/net.h>

#include <isc/once.h>

#include <isc/strerror.h>

#include <isc/string.h>

#include <isc/util.h>

/*%

 * Definitions about UDP port range specification.  This is a total mess of

 * portability variants: some use sysctl (but the sysctl names vary), some use

 * system-specific interfaces, some have the same interface for IPv4 and IPv6,

 * some separate them, etc...

 */

/*%

 * The last resort defaults: use all non well known port space

 */

#ifndef ISC_NET_PORTRANGELOW

#define ISC_NET_PORTRANGELOW 1024

#endif  /* ISC_NET_PORTRANGELOW */

#ifndef ISC_NET_PORTRANGEHIGH

#define ISC_NET_PORTRANGEHIGH 65535

#endif  /* ISC_NET_PORTRANGEHIGH */

#ifdef HAVE_SYSCTLBYNAME

/*%

 * sysctl variants

 */

#if defined(__FreeBSD__) || defined(__APPLE__) || defined(__DragonFly__)

#define USE_SYSCTL_PORTRANGE

#define SYSCTL_V4PORTRANGE_LOW  "net.inet.ip.portrange.hifirst"

#define SYSCTL_V4PORTRANGE_HIGH "net.inet.ip.portrange.hilast"

#define SYSCTL_V6PORTRANGE_LOW  "net.inet.ip.portrange.hifirst"

#define SYSCTL_V6PORTRANGE_HIGH "net.inet.ip.portrange.hilast"

#endif

#ifdef __NetBSD__

#define USE_SYSCTL_PORTRANGE

#define SYSCTL_V4PORTRANGE_LOW  "net.inet.ip.anonportmin"

#define SYSCTL_V4PORTRANGE_HIGH "net.inet.ip.anonportmax"

#define SYSCTL_V6PORTRANGE_LOW  "net.inet6.ip6.anonportmin"

#define SYSCTL_V6PORTRANGE_HIGH "net.inet6.ip6.anonportmax"

#endif

#else /* !HAVE_SYSCTLBYNAME */

#ifdef __OpenBSD__

#define USE_SYSCTL_PORTRANGE

#define SYSCTL_V4PORTRANGE_LOW  { CTL_NET, PF_INET, IPPROTO_IP, \

          IPCTL_IPPORT_HIFIRSTAUTO }

#define SYSCTL_V4PORTRANGE_HIGH { CTL_NET, PF_INET, IPPROTO_IP, \

          IPCTL_IPPORT_HILASTAUTO }

/* Same for IPv6 */

#define SYSCTL_V6PORTRANGE_LOW  SYSCTL_V4PORTRANGE_LOW

#define SYSCTL_V6PORTRANGE_HIGH SYSCTL_V4PORTRANGE_HIGH

#endif

#endif /* HAVE_SYSCTLBYNAME */

#if defined(ISC_PLATFORM_NEEDIN6ADDRANY)

const struct in6_addr isc_net_in6addrany = IN6ADDR_ANY_INIT;

#endif

#if defined(ISC_PLATFORM_HAVEIPV6)

# if defined(ISC_PLATFORM_NEEDIN6ADDRLOOPBACK)

const struct in6_addr isc_net_in6addrloop = IN6ADDR_LOOPBACK_INIT;

# endif

# if defined(WANT_IPV6)

static isc_once_t   once_ipv6only = ISC_ONCE_INIT;

# endif

# if defined(ISC_PLATFORM_HAVEIPV6) && \

     defined(WANT_IPV6) && defined(ISC_PLATFORM_HAVEIN6PKTINFO)

static isc_once_t   once_ipv6pktinfo = ISC_ONCE_INIT;

# endif

#endif /* ISC_PLATFORM_HAVEIPV6 */

static isc_once_t   once = ISC_ONCE_INIT;

static isc_result_t ipv4_result = ISC_R_NOTFOUND;

static isc_result_t ipv6_result = ISC_R_NOTFOUND;

static isc_result_t unix_result = ISC_R_NOTFOUND;

static isc_result_t ipv6only_result = ISC_R_NOTFOUND;

static isc_result_t ipv6pktinfo_result = ISC_R_NOTFOUND;

static isc_result_t

try_proto(int domain) {

  int s;

  isc_result_t result = ISC_R_SUCCESS;

  char strbuf[ISC_STRERRORSIZE];

  s = socket(domain, SOCK_STREAM, 0);

  if (s == -1) {

    switch (errno) {

#ifdef EAFNOSUPPORT

    case EAFNOSUPPORT:

#endif

#ifdef EPROTONOSUPPORT

    case EPROTONOSUPPORT:

#endif

#ifdef EINVAL

    case EINVAL:

#endif

      return (ISC_R_NOTFOUND);

    default:

      isc__strerror(errno, strbuf, sizeof(strbuf));

      UNEXPECTED_ERROR(__FILE__, __LINE__,

           "socket() %s: %s",

           isc_msgcat_get(isc_msgcat,

              ISC_MSGSET_GENERAL,

              ISC_MSG_FAILED,

              "failed"),

           strbuf);

      return (ISC_R_UNEXPECTED);

    }

  }

#ifdef ISC_PLATFORM_HAVEIPV6

#ifdef WANT_IPV6

#ifdef ISC_PLATFORM_HAVEIN6PKTINFO

  if (domain == PF_INET6) {

    struct sockaddr_in6 sin6;

    GETSOCKNAME_SOCKLEN_TYPE len; /* NTP local change */

    /*

     * Check to see if IPv6 is broken, as is common on Linux.

     */

    len = sizeof(sin6);

    if (getsockname(s, (struct sockaddr *)&sin6, &len) < 0)

    {

      isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,

              ISC_LOGMODULE_SOCKET, ISC_LOG_ERROR,

              "retrieving the address of an IPv6 "

              "socket from the kernel failed.");

      isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,

              ISC_LOGMODULE_SOCKET, ISC_LOG_ERROR,

              "IPv6 is not supported.");

      result = ISC_R_NOTFOUND;

    } else {

      if (len == sizeof(struct sockaddr_in6))

        result = ISC_R_SUCCESS;

      else {

        isc_log_write(isc_lctx,

                ISC_LOGCATEGORY_GENERAL,

                ISC_LOGMODULE_SOCKET,

                ISC_LOG_ERROR,

                "IPv6 structures in kernel and "

                "user space do not match.");

        isc_log_write(isc_lctx,

                ISC_LOGCATEGORY_GENERAL,

                ISC_LOGMODULE_SOCKET,

                ISC_LOG_ERROR,

                "IPv6 is not supported.");

        result = ISC_R_NOTFOUND;

      }

    }

  }

#endif

#endif

#endif

  (void)close(s);

  return (result);

}

static void

initialize_action(void) {

  ipv4_result = try_proto(PF_INET);

#ifdef ISC_PLATFORM_HAVEIPV6

#ifdef WANT_IPV6

#ifdef ISC_PLATFORM_HAVEIN6PKTINFO

  ipv6_result = try_proto(PF_INET6);

#endif

#endif

#endif

#ifdef ISC_PLATFORM_HAVESYSUNH

  unix_result = try_proto(PF_UNIX);

#endif

}

static void

initialize(void) {

  RUNTIME_CHECK(isc_once_do(&once, initialize_action) == ISC_R_SUCCESS);

}

isc_result_t

isc_net_probeipv4(void) {

  initialize();

  return (ipv4_result);

}

isc_result_t

isc_net_probeipv6(void) {

  initialize();

  return (ipv6_result);

}

isc_result_t

isc_net_probeunix(void) {

  initialize();

  return (unix_result);

}

#ifdef ISC_PLATFORM_HAVEIPV6

#ifdef WANT_IPV6

static void

try_ipv6only(void) {

#ifdef IPV6_V6ONLY

  int s, on;

  char strbuf[ISC_STRERRORSIZE];

#endif

  isc_result_t result;

  result = isc_net_probeipv6();

  if (result != ISC_R_SUCCESS) {

    ipv6only_result = result;

    return;

  }

#ifndef IPV6_V6ONLY

  ipv6only_result = ISC_R_NOTFOUND;

  return;

#else

  /* check for TCP sockets */

  s = socket(PF_INET6, SOCK_STREAM, 0);

  if (s == -1) {

    isc__strerror(errno, strbuf, sizeof(strbuf));

    UNEXPECTED_ERROR(__FILE__, __LINE__,

         "socket() %s: %s",

         isc_msgcat_get(isc_msgcat,

            ISC_MSGSET_GENERAL,

            ISC_MSG_FAILED,

            "failed"),

         strbuf);

    ipv6only_result = ISC_R_UNEXPECTED;

    return;

  }

  on = 1;

  if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) {

    ipv6only_result = ISC_R_NOTFOUND;

    goto close;

  }

  close(s);

  /* check for UDP sockets */

  s = socket(PF_INET6, SOCK_DGRAM, 0);

  if (s == -1) {

    isc__strerror(errno, strbuf, sizeof(strbuf));

    UNEXPECTED_ERROR(__FILE__, __LINE__,

         "socket() %s: %s",

         isc_msgcat_get(isc_msgcat,

            ISC_MSGSET_GENERAL,

            ISC_MSG_FAILED,

            "failed"),

         strbuf);

    ipv6only_result = ISC_R_UNEXPECTED;

    return;

  }

  on = 1;

  if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) {

    ipv6only_result = ISC_R_NOTFOUND;

    goto close;

  }

  ipv6only_result = ISC_R_SUCCESS;

close:

  close(s);

  return;

#endif /* IPV6_V6ONLY */

}

static void

initialize_ipv6only(void) {

  RUNTIME_CHECK(isc_once_do(&once_ipv6only,

          try_ipv6only) == ISC_R_SUCCESS);

}

#ifdef ISC_PLATFORM_HAVEIN6PKTINFO

static void

try_ipv6pktinfo(void) {

  int s, on;

  char strbuf[ISC_STRERRORSIZE];

  isc_result_t result;

  int optname;

  result = isc_net_probeipv6();

  if (result != ISC_R_SUCCESS) {

    ipv6pktinfo_result = result;

    return;

  }

  /* we only use this for UDP sockets */

  s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);

  if (s == -1) {

    isc__strerror(errno, strbuf, sizeof(strbuf));

    UNEXPECTED_ERROR(__FILE__, __LINE__,

         "socket() %s: %s",

         isc_msgcat_get(isc_msgcat,

            ISC_MSGSET_GENERAL,

            ISC_MSG_FAILED,

            "failed"),

         strbuf);

    ipv6pktinfo_result = ISC_R_UNEXPECTED;

    return;

  }

#ifdef IPV6_RECVPKTINFO

  optname = IPV6_RECVPKTINFO;

#else

  optname = IPV6_PKTINFO;

#endif

  on = 1;

  if (setsockopt(s, IPPROTO_IPV6, optname, &on, sizeof(on)) < 0) {

    ipv6pktinfo_result = ISC_R_NOTFOUND;

    goto close;

  }

  ipv6pktinfo_result = ISC_R_SUCCESS;

close:

  close(s);

  return;

}

static void

initialize_ipv6pktinfo(void) {

  RUNTIME_CHECK(isc_once_do(&once_ipv6pktinfo,

          try_ipv6pktinfo) == ISC_R_SUCCESS);

}

#endif /* ISC_PLATFORM_HAVEIN6PKTINFO */

#endif /* WANT_IPV6 */

#endif /* ISC_PLATFORM_HAVEIPV6 */

isc_result_t

isc_net_probe_ipv6only(void) {

#ifdef ISC_PLATFORM_HAVEIPV6

#ifdef WANT_IPV6

  initialize_ipv6only();

#else

  ipv6only_result = ISC_R_NOTFOUND;

#endif

#endif

  return (ipv6only_result);

}

isc_result_t

isc_net_probe_ipv6pktinfo(void) {

#ifdef ISC_PLATFORM_HAVEIPV6

#ifdef ISC_PLATFORM_HAVEIN6PKTINFO

#ifdef WANT_IPV6

  initialize_ipv6pktinfo();

#else

  ipv6pktinfo_result = ISC_R_NOTFOUND;

#endif

#endif

#endif

  return (ipv6pktinfo_result);

}

#if defined(USE_SYSCTL_PORTRANGE)

#if defined(HAVE_SYSCTLBYNAME)

static isc_result_t

getudpportrange_sysctl(int af, in_port_t *low, in_port_t *high) {

  int port_low, port_high;

  size_t portlen;

  const char *sysctlname_lowport, *sysctlname_hiport;

  if (af == AF_INET) {

    sysctlname_lowport = SYSCTL_V4PORTRANGE_LOW;

    sysctlname_hiport = SYSCTL_V4PORTRANGE_HIGH;

  } else {

    sysctlname_lowport = SYSCTL_V6PORTRANGE_LOW;

    sysctlname_hiport = SYSCTL_V6PORTRANGE_HIGH;

  }

  portlen = sizeof(portlen);

  if (sysctlbyname(sysctlname_lowport, &port_low, &portlen,

       NULL, 0) < 0) {

    return (ISC_R_FAILURE);

  }

  portlen = sizeof(portlen);

  if (sysctlbyname(sysctlname_hiport, &port_high, &portlen,

       NULL, 0) < 0) {

    return (ISC_R_FAILURE);

  }

  if ((port_low & ~0xffff) != 0 || (port_high & ~0xffff) != 0)

    return (ISC_R_RANGE);

  *low = (in_port_t)port_low;

  *high = (in_port_t)port_high;

  return (ISC_R_SUCCESS);

}

#else /* !HAVE_SYSCTLBYNAME */

static isc_result_t

getudpportrange_sysctl(int af, in_port_t *low, in_port_t *high) {

  int mib_lo4[4] = SYSCTL_V4PORTRANGE_LOW;

  int mib_hi4[4] = SYSCTL_V4PORTRANGE_HIGH;

  int mib_lo6[4] = SYSCTL_V6PORTRANGE_LOW;

  int mib_hi6[4] = SYSCTL_V6PORTRANGE_HIGH;

  int *mib_lo, *mib_hi, miblen;

  int port_low, port_high;

  size_t portlen;

  if (af == AF_INET) {

    mib_lo = mib_lo4;

    mib_hi = mib_hi4;

    miblen = sizeof(mib_lo4) / sizeof(mib_lo4[0]);

  } else {

    mib_lo = mib_lo6;

    mib_hi = mib_hi6;

    miblen = sizeof(mib_lo6) / sizeof(mib_lo6[0]);

  }

  portlen = sizeof(portlen);

  if (sysctl(mib_lo, miblen, &port_low, &portlen, NULL, 0) < 0) {

    return (ISC_R_FAILURE);

  }

  portlen = sizeof(portlen);

  if (sysctl(mib_hi, miblen, &port_high, &portlen, NULL, 0) < 0) {

    return (ISC_R_FAILURE);

  }

  if ((port_low & ~0xffff) != 0 || (port_high & ~0xffff) != 0)

    return (ISC_R_RANGE);

  *low = (in_port_t) port_low;

  *high = (in_port_t) port_high;

  return (ISC_R_SUCCESS);

}

#endif /* HAVE_SYSCTLBYNAME */

#endif /* USE_SYSCTL_PORTRANGE */

isc_result_t

isc_net_getudpportrange(int af, in_port_t *low, in_port_t *high) {

  int result = ISC_R_FAILURE;

  REQUIRE(low != NULL && high != NULL);

#if defined(USE_SYSCTL_PORTRANGE)

  result = getudpportrange_sysctl(af, low, high);

#else

  UNUSED(af);

#endif

  if (result != ISC_R_SUCCESS) {

    *low = ISC_NET_PORTRANGELOW;

    *high = ISC_NET_PORTRANGEHIGH;

  }

  return (ISC_R_SUCCESS);  /* we currently never fail in this function */

}

void

isc_net_disableipv4(void) {

  initialize();

  if (ipv4_result == ISC_R_SUCCESS)

    ipv4_result = ISC_R_DISABLED;

}

void

isc_net_disableipv6(void) {

  initialize();

  if (ipv6_result == ISC_R_SUCCESS)

    ipv6_result = ISC_R_DISABLED;

}

void

isc_net_enableipv4(void) {

  initialize();

  if (ipv4_result == ISC_R_DISABLED)

    ipv4_result = ISC_R_SUCCESS;

}

void

isc_net_enableipv6(void) {

  initialize();

  if (ipv6_result == ISC_R_DISABLED)

    ipv6_result = ISC_R_SUCCESS;

}