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Sourcecode: postgresql-8.4 version File versions

ip.c

/*-------------------------------------------------------------------------
 *
 * 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
 *
 *
 * IDENTIFICATION
 *      $PostgreSQL: pgsql/src/backend/libpq/ip.c,v 1.45 2009/04/23 23:25:13 tgl 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 "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 "libpq/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

#ifdef      HAVE_UNIX_SOCKETS
static int getaddrinfo_unix(const char *path,
                         const struct addrinfo * hintsp,
                         struct addrinfo ** result);

static int getnameinfo_unix(const struct sockaddr_un * sa, int salen,
                         char *node, int nodelen,
                         char *service, int servicelen,
                         int flags);
#endif


/*
 *    pg_getaddrinfo_all - get address info for Unix, IPv4 and IPv6 sockets
 */
int
pg_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;

#ifdef HAVE_UNIX_SOCKETS
      if (hintp->ai_family == AF_UNIX)
            return getaddrinfo_unix(servname, hintp, result);
#endif

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

#else /* _AIX */

      /*
       * Various versions of AIX have various bugs in getaddrinfo()'s handling
       * of the servname parameter, including failing entirely if it's not NULL
       * and failing to zero sin_port when it is NULL :-(.  Avoid these by
       * always passing NULL and handling the port number for ourselves.
       */
      rc = getaddrinfo((!hostname || hostname[0] == '\0') ? NULL : hostname,
                               NULL, hintp, result);

      if (rc == 0)
      {
            struct addrinfo *addr;
            unsigned short port = 0;

            if (servname && *servname)
                  port = atoi(servname);

            for (addr = *result; addr; addr = addr->ai_next)
            {
                  switch (addr->ai_family)
                  {
                        case AF_INET:
                              ((struct sockaddr_in *) addr->ai_addr)->sin_port = htons(port);
                              break;
#ifdef HAVE_IPV6
                        case AF_INET6:
                              ((struct sockaddr_in6 *) addr->ai_addr)->sin6_port = htons(port);
                              break;
#endif
                  }
            }
      }
#endif /* _AIX */

      return rc;
}


/*
 *    pg_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
pg_freeaddrinfo_all(int hint_ai_family, struct addrinfo * ai)
{
#ifdef HAVE_UNIX_SOCKETS
      if (hint_ai_family == AF_UNIX)
      {
            /* struct was built by getaddrinfo_unix (see pg_getaddrinfo_all) */
            while (ai != NULL)
            {
                  struct addrinfo *p = ai;

                  ai = ai->ai_next;
                  free(p->ai_addr);
                  free(p);
            }
      }
      else
#endif   /* HAVE_UNIX_SOCKETS */
      {
            /* struct was built by getaddrinfo() */
            if (ai != NULL)
                  freeaddrinfo(ai);
      }
}


/*
 *    pg_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
pg_getnameinfo_all(const struct sockaddr_storage * addr, int salen,
                           char *node, int nodelen,
                           char *service, int servicelen,
                           int flags)
{
      int               rc;

#ifdef HAVE_UNIX_SOCKETS
      if (addr && addr->ss_family == AF_UNIX)
            rc = getnameinfo_unix((const struct sockaddr_un *) addr, salen,
                                            node, nodelen,
                                            service, servicelen,
                                            flags);
      else
#endif
            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;
}


#if defined(HAVE_UNIX_SOCKETS)

/* -------
 *    getaddrinfo_unix - get unix socket info using IPv6-compatible API
 *
 *    Bugs: only one addrinfo is set even though hintsp is NULL or
 *            ai_socktype is 0
 *            AI_CANONNAME is not supported.
 * -------
 */
static int
getaddrinfo_unix(const char *path, const struct addrinfo * hintsp,
                         struct addrinfo ** result)
{
      struct addrinfo hints;
      struct addrinfo *aip;
      struct sockaddr_un *unp;

      *result = NULL;

      MemSet(&hints, 0, sizeof(hints));

      if (strlen(path) >= sizeof(unp->sun_path))
            return EAI_FAIL;

      if (hintsp == NULL)
      {
            hints.ai_family = AF_UNIX;
            hints.ai_socktype = SOCK_STREAM;
      }
      else
            memcpy(&hints, hintsp, sizeof(hints));

      if (hints.ai_socktype == 0)
            hints.ai_socktype = SOCK_STREAM;

      if (hints.ai_family != AF_UNIX)
      {
            /* shouldn't have been called */
            return EAI_FAIL;
      }

      aip = calloc(1, sizeof(struct addrinfo));
      if (aip == NULL)
            return EAI_MEMORY;

      unp = calloc(1, sizeof(struct sockaddr_un));
      if (unp == NULL)
      {
            free(aip);
            return EAI_MEMORY;
      }

      aip->ai_family = AF_UNIX;
      aip->ai_socktype = hints.ai_socktype;
      aip->ai_protocol = hints.ai_protocol;
      aip->ai_next = NULL;
      aip->ai_canonname = NULL;
      *result = aip;

      unp->sun_family = AF_UNIX;
      aip->ai_addr = (struct sockaddr *) unp;
      aip->ai_addrlen = sizeof(struct sockaddr_un);

      strcpy(unp->sun_path, path);

#ifdef HAVE_STRUCT_SOCKADDR_STORAGE_SS_LEN
      unp->sun_len = sizeof(struct sockaddr_un);
#endif

      return 0;
}

/*
 * Convert an address to a hostname.
 */
static int
getnameinfo_unix(const struct sockaddr_un * sa, int salen,
                         char *node, int nodelen,
                         char *service, int servicelen,
                         int flags)
{
      int               ret = -1;

      /* Invalid arguments. */
      if (sa == NULL || sa->sun_family != AF_UNIX ||
            (node == NULL && service == NULL))
            return EAI_FAIL;

      /* We don't support those. */
      if ((node && !(flags & NI_NUMERICHOST))
            || (service && !(flags & NI_NUMERICSERV)))
            return EAI_FAIL;

      if (node)
      {
            ret = snprintf(node, nodelen, "%s", "[local]");
            if (ret == -1 || ret > nodelen)
                  return EAI_MEMORY;
      }

      if (service)
      {
            ret = snprintf(service, servicelen, "%s", sa->sun_path);
            if (ret == -1 || ret > servicelen)
                  return EAI_MEMORY;
      }

      return 0;
}
#endif   /* HAVE_UNIX_SOCKETS */


/*
 * pg_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
pg_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 */

/*
 *    pg_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
pg_sockaddr_cidr_mask(struct sockaddr_storage * mask, char *numbits, int family)
{
      long        bits;
      char     *endptr;

      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;
                        memset(&mask4, 0, sizeof(mask4));
                        /* 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);
                        memcpy(mask, &mask4, sizeof(mask4));
                        break;
                  }

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

                        if (bits < 0 || bits > 128)
                              return -1;
                        memset(&mask6, 0, sizeof(mask6));
                        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;
                        }
                        memcpy(mask, &mask6, sizeof(mask6));
                        break;
                  }
#endif
            default:
                  return -1;
      }

      mask->ss_family = family;
      return 0;
}


#ifdef HAVE_IPV6

/*
 * pg_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 pg_range_sockaddr will look at.
 */
void
pg_promote_v4_to_v6_addr(struct sockaddr_storage * addr)
{
      struct sockaddr_in addr4;
      struct sockaddr_in6 addr6;
      uint32            ip4addr;

      memcpy(&addr4, addr, sizeof(addr4));
      ip4addr = ntohl(addr4.sin_addr.s_addr);

      memset(&addr6, 0, sizeof(addr6));

      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;

      memcpy(addr, &addr6, sizeof(addr6));
}

/*
 * pg_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 pg_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 pg_range_sockaddr will look at.
 */
void
pg_promote_v4_to_v6_mask(struct sockaddr_storage * addr)
{
      struct sockaddr_in addr4;
      struct sockaddr_in6 addr6;
      uint32            ip4addr;
      int               i;

      memcpy(&addr4, addr, sizeof(addr4));
      ip4addr = ntohl(addr4.sin_addr.s_addr);

      memset(&addr6, 0, sizeof(addr6));

      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;

      memcpy(addr, &addr6, sizeof(addr6));
}

#endif   /* HAVE_IPV6 */

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