/* -------------------------------------------------------------------------
 *
 * ip.c
 *	  IPv6-aware network access.
 *
 * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 * Portions Copyright (c) 2010-2012 Postgres-XC Development Group
 *
 *
 * IDENTIFICATION
 *	  $PostgreSQL: pgsql/src/backend/libpq/ip.c,v 1.43 2009/01/01 17:23:42 momjian Exp $
 *
 * This file and the IPV6 implementation were initially provided by
 * Nigel Kukard <nkukard@lbsd.net>, Linux Based Systems Design
 * http://www.lbsd.net.
 *
 * -------------------------------------------------------------------------
 */

/* This is intended to be used in both frontend and backend, so use c.h */
#include "gtm/gtm_c.h"

#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#ifdef HAVE_NETINET_TCP_H
#include <netinet/tcp.h>
#endif
#include <arpa/inet.h>
#include <sys/file.h>

#include "gtm/gtm_ip.h"

static int range_sockaddr_AF_INET(
    const struct sockaddr_in* addr, const struct sockaddr_in* netaddr, const struct sockaddr_in* netmask);

#ifdef HAVE_IPV6
static int range_sockaddr_AF_INET6(
    const struct sockaddr_in6* addr, const struct sockaddr_in6* netaddr, const struct sockaddr_in6* netmask);
#endif

/*
 *	gtm_getaddrinfo_all - get address info for Unix, IPv4 and IPv6 sockets
 */
int gtm_getaddrinfo_all(
    const char* hostname, const char* servname, const struct addrinfo* hintp, struct addrinfo** result)
{
    int rc;

    /* not all versions of getaddrinfo() zero *result on failure */
    *result = NULL;

    /* NULL has special meaning to getaddrinfo(). */
    rc = getaddrinfo((!hostname || hostname[0] == '\0') ? NULL : hostname, servname, hintp, result);

    return rc;
}

/*
 *	gtm_freeaddrinfo_all - free addrinfo structures for IPv4, IPv6, or Unix
 *
 * Note: the ai_family field of the original hint structure must be passed
 * so that we can tell whether the addrinfo struct was built by the system's
 * getaddrinfo() routine or our own getaddrinfo_unix() routine.  Some versions
 * of getaddrinfo() might be willing to return AF_UNIX addresses, so it's
 * not safe to look at ai_family in the addrinfo itself.
 */
void gtm_freeaddrinfo_all(int hint_ai_family, struct addrinfo* ai)
{
    {
        /* struct was built by getaddrinfo() */
        if (ai != NULL) {
            freeaddrinfo(ai);
        }
    }
}

/*
 *	gtm_getnameinfo_all - get name info for Unix, IPv4 and IPv6 sockets
 *
 * The API of this routine differs from the standard getnameinfo() definition
 * in two ways: first, the addr parameter is declared as sockaddr_storage
 * rather than struct sockaddr, and second, the node and service fields are
 * guaranteed to be filled with something even on failure return.
 */
int gtm_getnameinfo_all(
    const struct sockaddr_storage* addr, int salen, char* node, int nodelen, char* service, int servicelen, int flags)
{
    int rc;

    rc = getnameinfo((const struct sockaddr*)addr, salen, node, nodelen, service, servicelen, flags);

    if (rc != 0) {
        if (node) {
            strlcpy(node, "???", nodelen);
        }

        if (service) {
            strlcpy(service, "???", servicelen);
        }
    }

    return rc;
}

/*
 * gtm_range_sockaddr - is addr within the subnet specified by netaddr/netmask ?
 *
 * Note: caller must already have verified that all three addresses are
 * in the same address family; and AF_UNIX addresses are not supported.
 */
int gtm_range_sockaddr(
    const struct sockaddr_storage* addr, const struct sockaddr_storage* netaddr, const struct sockaddr_storage* netmask)
{
    if (addr->ss_family == AF_INET) {
        return range_sockaddr_AF_INET(
            (struct sockaddr_in*)addr, (struct sockaddr_in*)netaddr, (struct sockaddr_in*)netmask);

#ifdef HAVE_IPV6
    else if (addr->ss_family == AF_INET6) {
        return range_sockaddr_AF_INET6(
            (struct sockaddr_in6*)addr, (struct sockaddr_in6*)netaddr, (struct sockaddr_in6*)netmask);
#endif

    } else {
        return 0;
    }
}

static int range_sockaddr_AF_INET(
    const struct sockaddr_in* addr, const struct sockaddr_in* netaddr, const struct sockaddr_in* netmask)
{
    if (((addr->sin_addr.s_addr ^ netaddr->sin_addr.s_addr) & netmask->sin_addr.s_addr) == 0) {
        return 1;
    } else {
        return 0;
    }
}

#ifdef HAVE_IPV6

static int range_sockaddr_AF_INET6(
    const struct sockaddr_in6* addr, const struct sockaddr_in6* netaddr, const struct sockaddr_in6* netmask)
{
    int i;

    for (i = 0; i < 16; i++) {
        if (((addr->sin6_addr.s6_addr[i] ^ netaddr->sin6_addr.s6_addr[i]) & netmask->sin6_addr.s6_addr[i]) != 0)
            return 0;
    }

    return 1;
}
#endif /* HAVE_IPV6 */

/*
 *	gtm_sockaddr_cidr_mask - make a network mask of the appropriate family
 *	  and required number of significant bits
 *
 * The resulting mask is placed in *mask, which had better be big enough.
 *
 * Return value is 0 if okay, -1 if not.
 */
int gtm_sockaddr_cidr_mask(struct sockaddr_storage* mask, char* numbits, int family)
{
    long bits;
    char* endptr;
    errno_t rc = EOK;

    bits = strtol(numbits, &endptr, 10);

    if (*numbits == '\0' || *endptr != '\0') {
        return -1;
    }

    switch (family) {
        case AF_INET: {
            struct sockaddr_in mask4;
            long maskl;

            if (bits < 0 || bits > 32) {
                return -1;
            }

            /* avoid "x << 32", which is not portable */
            if (bits > 0) {
                maskl = (0xffffffffUL << (32 - (int)bits)) & 0xffffffffUL;
            } else {
                maskl = 0;
            }

            mask4.sin_addr.s_addr = htonl(maskl);
            rc = memcpy_s(mask, sizeof(mask4), &mask4, sizeof(mask4));
            securec_check(rc, "\0", "\0");

            break;
        }

#ifdef HAVE_IPV6
        case AF_INET6: {
            struct sockaddr_in6 mask6;
            int i;

            if (bits < 0 || bits > 128) {
                return -1;
            }

            for (i = 0; i < 16; i++) {
                if (bits <= 0) {
                    mask6.sin6_addr.s6_addr[i] = 0;
                } else if (bits >= 8) {
                    mask6.sin6_addr.s6_addr[i] = 0xff;
                } else {
                    mask6.sin6_addr.s6_addr[i] = (0xff << (8 - (int)bits)) & 0xff;
                }
                bits -= 8;
            }
            rc = memcpy_s(mask, sizeof(mask6), &mask6, sizeof(mask6));
            securec_check(rc, "\0", "\0");
            break;
        }
#endif
        default:
            return -1;
    }

    mask->ss_family = family;
    return 0;
}

#ifdef HAVE_IPV6

/*
 * gtm_promote_v4_to_v6_addr --- convert an AF_INET addr to AF_INET6, using
 *		the standard convention for IPv4 addresses mapped into IPv6 world
 *
 * The passed addr is modified in place; be sure it is large enough to
 * hold the result!  Note that we only worry about setting the fields
 * that gtm_range_sockaddr will look at.
 */
void gtm_promote_v4_to_v6_addr(struct sockaddr_storage* addr)
{
    struct sockaddr_in addr4;
    struct sockaddr_in6 addr6;
    uint32 ip4addr;
    errno_t rc = EOK;

    rc = memcpy_s(&addr4, sizeof(addr4), addr, sizeof(addr4));
    securec_check(rc, "\0", "\0");
    ip4addr = ntohl(addr4.sin_addr.s_addr);

    rc = memset_s(&addr6, sizeof(addr6), 0, sizeof(addr6));
    securec_check(rc, "\0", "\0");

    addr6.sin6_family = AF_INET6;

    addr6.sin6_addr.s6_addr[10] = 0xff;
    addr6.sin6_addr.s6_addr[11] = 0xff;
    addr6.sin6_addr.s6_addr[12] = (ip4addr >> 24) & 0xFF;
    addr6.sin6_addr.s6_addr[13] = (ip4addr >> 16) & 0xFF;
    addr6.sin6_addr.s6_addr[14] = (ip4addr >> 8) & 0xFF;
    addr6.sin6_addr.s6_addr[15] = (ip4addr)&0xFF;

    rc = memcpy_s(addr, sizeof(addr6), &addr6, sizeof(addr6));
    securec_check(rc, "\0", "\0");
}

/*
 * gtm_promote_v4_to_v6_mask --- convert an AF_INET netmask to AF_INET6, using
 *		the standard convention for IPv4 addresses mapped into IPv6 world
 *
 * This must be different from gtm_promote_v4_to_v6_addr because we want to
 * set the high-order bits to 1's not 0's.
 *
 * The passed addr is modified in place; be sure it is large enough to
 * hold the result!  Note that we only worry about setting the fields
 * that gtm_range_sockaddr will look at.
 */
void gtm_promote_v4_to_v6_mask(struct sockaddr_storage* addr)
{
    struct sockaddr_in addr4;
    struct sockaddr_in6 addr6;
    uint32 ip4addr;
    int i;
    errno_t rc = EOK;

    rc = memcpy_s(&addr4, sizeof(addr4), addr, sizeof(addr4));
    securec_check(rc, "\0", "\0");
    ip4addr = ntohl(addr4.sin_addr.s_addr);

    rc = memset_s(&addr6, sizeof(addr6), 0, sizeof(addr6));
    securec_check(rc, "\0", "\0");

    addr6.sin6_family = AF_INET6;

    for (i = 0; i < 12; i++) {
        addr6.sin6_addr.s6_addr[i] = 0xff;
    }

    addr6.sin6_addr.s6_addr[12] = (ip4addr >> 24) & 0xFF;
    addr6.sin6_addr.s6_addr[13] = (ip4addr >> 16) & 0xFF;
    addr6.sin6_addr.s6_addr[14] = (ip4addr >> 8) & 0xFF;
    addr6.sin6_addr.s6_addr[15] = (ip4addr)&0xFF;

    rc = memcpy_s(addr, sizeof(addr6), &addr6, sizeof(addr6));
    securec_check(rc, "\0", "\0");
}

#endif /* HAVE_IPV6 */