network.c

/*
 * network.c: network helper APIs for libvirt
 *
 * Copyright (C) 2009-2009 Red Hat, Inc.
 *
 * See COPYING.LIB for the License of this software
 *
 * Daniel Veillard <veillard@redhat.com>
 */

#include <config.h>

#include "memory.h"
#include "network.h"

/*
 * Helpers to extract the IP arrays from the virSocketAddrPtr
 * That part is the less portable of the module
 */
typedef unsigned char virIPv4Addr[4];
typedef virIPv4Addr *virIPv4AddrPtr;
typedef unsigned short virIPv6Addr[8];
typedef virIPv6Addr *virIPv6AddrPtr;

static int getIPv4Addr(virSocketAddrPtr addr, virIPv4AddrPtr tab) {
    unsigned long val;
    int i;

    if ((addr == NULL) || (tab == NULL) || (addr->stor.ss_family != AF_INET))
        return(-1);

    val = ntohl(addr->inet4.sin_addr.s_addr);

    for (i = 0;i < 4;i++) {
        (*tab)[i] = val & 0xFF;
        val >>= 8;
    }

    return(0);
}

static int getIPv6Addr(virSocketAddrPtr addr, virIPv6AddrPtr tab) {
    virIPv6AddrPtr val;
    int i;

    if ((addr == NULL) || (tab == NULL) || (addr->stor.ss_family != AF_INET6))
        return(-1);

    val = (virIPv6AddrPtr) &(addr->inet6.sin6_addr.__in6_u.__u6_addr16);

    for (i = 0;i < 8;i++) {
        (*tab)[i] = ntohs((*val)[i]);
    }

    return(0);
}

/**
 * virSocketParseAddr:
 * @val: a numeric network address IPv4 or IPv6
 * @addr: where to store the return value.
 * @hint: optional hint to pass down to getaddrinfo
 *
 * Mostly a wrapper for getaddrinfo() extracting the address storage
 * from the numeric string like 1.2.3.4 or 2001:db8:85a3:0:0:8a2e:370:7334
 *
 * Returns the lenght of the network address or -1 in case of error.
 */
int
virSocketParseAddr(const char *val, virSocketAddrPtr addr, int hint) {
    int len;
    struct addrinfo hints;
    struct addrinfo *res = NULL;

    if ((val == NULL) || (addr == NULL))
        return(-1);

    memset(&hints, 0, sizeof(hints));
    hints.ai_flags = AI_NUMERICHOST | hint;
    if ((getaddrinfo(val, NULL, &hints, &res) != 0) || (res ==  NULL)) {
        return(-1);
    }

    len = res->ai_addrlen;
    memcpy(&addr->stor, res->ai_addr, len);

    freeaddrinfo(res);
    return(len);
}

/*
 * virSocketParseIpv4Addr:
 * @val: an IPv4 numeric address
 * @addr: the loacation to store the result
 *
 * Extract the address storage from an IPv4 numeric address
 *
 * Returns the lenght of the network address or -1 in case of error.
 */
int
virSocketParseIpv4Addr(const char *val, virSocketAddrPtr addr) {
    return(virSocketParseAddr(val, addr, AF_INET));
}

/*
 * virSocketParseIpv6Addr:
 * @val: an IPv6 numeric address
 * @addr: the loacation to store the result
 *
 * Extract the address storage from an IPv6 numeric address
 *
 * Returns the lenght of the network address or -1 in case of error.
 */
int
virSocketParseIpv6Addr(const char *val, virSocketAddrPtr addr) {
    return(virSocketParseAddr(val, addr, AF_INET6));
}

/**
 * virSocketAddrIsNetmask:
 * @netmask: the netmask address
 *
 * Check that @netmask is a proper network mask
 *
 * Returns 0 in case of success and -1 in case of error
 */
int virSocketAddrIsNetmask(virSocketAddrPtr netmask) {
    int i;

    if (netmask == NULL)
        return(-1);

    if (netmask->stor.ss_family == AF_INET) {
        virIPv4Addr tm;
        unsigned char tmp;
        int ok = 0;

        if (getIPv4Addr(netmask, &tm) < 0)
            return(-1);

        for (i = 0;i < 4;i++) {
           if (tm[i] != 0)
               break;
        }

        if (i >= 4)
            return(0);

        tmp = 0xFF;
        do {
            if (tm[i] == tmp) {
                ok = 1;
                break;
            }
            tmp <<= 1;
        } while (tmp != 0);
        if (ok == 0)
            return(-1);
        i++;

        if (i >= 4)
            return(0);

        for (;i < 4;i++) {
            if (tm[i] != 0xFF)
                return(-1);
        }
    } else if (netmask->stor.ss_family == AF_INET6) {
        virIPv6Addr tm;
        unsigned short tmp;
        int ok = 0;

        /*
         * Hum, on IPv6 people use prefixes instead of netmask
         */
        if (getIPv6Addr(netmask, &tm) < 0)
            return(-1);

        for (i = 0;i < 8;i++) {
           if (tm[i] != 0)
               break;
        }

        if (i >= 8)
            return(0);

        tmp = 0xFFFF;
        do {
            if (tm[i] == tmp) {
                ok = 1;
                break;
            }
            tmp <<= 1;
        } while (tmp != 0);
        if (ok == 0)
            return(-1);
        i++;

        if (i >= 8)
            return(0);

        for (;i < 8;i++) {
            if (tm[i] != 0xFFFF)
                return(-1);
        }
    } else {
        return(-1);
    }
    return(0);
}

/**
 * virSocketCheckNetmask:
 * @addr1: a first network address
 * @addr2: a second network address
 * @netmask: the netmask address
 *
 * Check that @addr1 and @addr2 pertain to the same @netmask address
 * range and returns the size of the range
 *
 * Returns 1 in case of success and 0 in case of failure and
 *         -1 in case of error
 */
int virSocketCheckNetmask(virSocketAddrPtr addr1, virSocketAddrPtr addr2,
                          virSocketAddrPtr netmask) {
    int i;

    if ((addr1 == NULL) || (addr2 == NULL) || (netmask == NULL))
        return(-1);
    if ((addr1->stor.ss_family != addr2->stor.ss_family) ||
        (addr1->stor.ss_family != netmask->stor.ss_family))
        return(-1);

    if (virSocketAddrIsNetmask(netmask) != 0)
        return(-1);

    if (addr1->stor.ss_family == AF_INET) {
        virIPv4Addr t1, t2, tm;

        if ((getIPv4Addr(addr1, &t1) < 0) ||
            (getIPv4Addr(addr2, &t2) < 0) ||
            (getIPv4Addr(netmask, &tm) < 0))
            return(-1);

        for (i = 0;i < 4;i++) {
            if ((t1[i] & tm[i]) != (t2[i] & tm[i]))
                return(0);
        }

    } else if (addr1->stor.ss_family == AF_INET) {
        virIPv6Addr t1, t2, tm;

        if ((getIPv6Addr(addr1, &t1) < 0) ||
            (getIPv6Addr(addr2, &t2) < 0) ||
            (getIPv6Addr(netmask, &tm) < 0))
            return(-1);

        for (i = 0;i < 8;i++) {
            if ((t1[i] & tm[i]) != (t2[i] & tm[i]))
                return(0);
        }

    } else {
        return(-1);
    }
    return(1);
}

/**
 * virSocketGetRange:
 * @start: start of an IP range
 * @end: end of an IP range
 *
 * Check the order of the 2 addresses and compute the range, this
 * will return 1 for identical addresses. Errors can come from incompatible
 * addresses type, excessive range (>= 2^^16) where the two addresses are
 * unrelated or inverted start and end.
 *
 * Returns the size of the range or -1 in case of failure
 */
int virSocketGetRange(virSocketAddrPtr start, virSocketAddrPtr end) {
    int ret = 0, i;

    if ((start == NULL) || (end == NULL))
        return(-1);
    if (start->stor.ss_family != end->stor.ss_family)
        return(-1);

    if (start->stor.ss_family == AF_INET) {
        virIPv4Addr t1, t2;

        if ((getIPv4Addr(start, &t1) < 0) ||
            (getIPv4Addr(end, &t2) < 0))
            return(-1);

        for (i = 0;i < 2;i++) {
            if (t1[i] != t2[i])
                return(-1);
        }
        ret = (t2[2] - t1[2]) * 256 + (t2[3] - t1[3]);
        if (ret < 0)
            return(-1);
        ret++;
    } else if (start->stor.ss_family == AF_INET6) {
        virIPv6Addr t1, t2;

        if ((getIPv6Addr(start, &t1) < 0) ||
            (getIPv6Addr(end, &t2) < 0))
            return(-1);

        for (i = 0;i < 7;i++) {
            if (t1[i] != t2[i])
                return(-1);
        }
        ret = t2[7] - t1[7];
        if (ret < 0)
            return(-1);
        ret++;
    } else {
        return(-1);
    }
    return(ret);
}