isc/unix/net.c

/*
 * 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: net.c,v 1.40 2008/07/04 05:52:31 each Exp $ */

#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_HAVEIPV6)
# if defined(ISC_PLATFORM_NEEDIN6ADDRANY)
const struct in6_addr isc_net_in6addrany = IN6ADDR_ANY_INIT;
# endif

# 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_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;
        unsigned int len;

        /*
         * Check to see if IPv6 is broken, as is common on Linux.
         */
        len = sizeof(sin6);
        if (getsockname(s, (struct sockaddr *)&sin6, (void *)&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);
}
#endif /* WANT_IPV6 */

#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 /* 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;
}