sunrpc: Always obtain AF_INET addresses from NSS [BZ #20964]

The new __libc_rpc_gethostbyname function calls gethostbyname2_r
with an AF_INET argument and is therefore not affected by the
RES_USE_INET6 flag.

Validated with the following test program, with and without
RES_OPTIONS=inet6, against a NFS server.  (Link with -lrpcsvc.)

#include <rpc/clnt.h>
#include <rpcsvc/mount.h>
#include <stdio.h>
#include <string.h>

static void
usage (char **argv)
{
  printf ("usage:\n"
          "  %1$s HOST getrpcport\n"
          "  %1$s HOST callrpc\n"
          "  %1$s HOST clnt_create\n",
          argv[0]);
}

static void
dump_exports (struct exportnode *exports)
{
  while (exports != NULL)
    {
      printf ("%s\n", exports->ex_dir);
      exports = exports->ex_next;
    }
}

int
main (int argc, char **argv)
{
  if (argc != 3)
    {
      usage (argv);
      return 1;
    }

  const char *host = argv[1];
  const char *command = argv[2];

  if (strcmp (command, "getrpcport") == 0)
    {
      int port = getrpcport (host, MOUNTPROG, MOUNTVERS, IPPROTO_UDP);
      printf ("getrpcport: %d\n", port);
    }
  else if (strcmp (command, "callrpc") == 0)
    {
      struct exportnode *exports = NULL;
      int ret = callrpc (host, MOUNTPROG, MOUNTVERS, MOUNTPROC_EXPORT,
                         (xdrproc_t) xdr_void, NULL,
                         (xdrproc_t) xdr_exports, (char *)&exports);
      if (ret != 0)
        {
          clnt_perrno (ret);
          puts ("");
          return 1;
        }
      dump_exports (exports);
    }
  else if (strcmp (command, "clnt_create") == 0)
    {
      CLIENT *client = clnt_create
        (host, MOUNTPROG, MOUNTVERS, "udp");
      if (client == NULL)
        {
          printf ("error: clnt_create failed\n");
          return 1;
        }
      struct exportnode *exports = NULL;
      int ret = CLNT_CALL (client, MOUNTPROC_EXPORT,
                           (xdrproc_t) xdr_void, NULL,
                           (xdrproc_t) xdr_exports, (char *)&exports,
                           ((struct timeval) {15, 0}));
      if (ret != 0)
        {
          clnt_perrno (ret);
          puts ("");
          return 1;
        }
      dump_exports (exports);
    }
  else
    {
      usage (argv);
      return 1;
    }

  return 0;
}

1 files changed, 2 insertions, 35 deletions

diff --git a/sunrpc/clnt_gen.c b/sunrpc/clnt_gen.c
index df34672..8dffaa9 100644
--- a/sunrpc/clnt_gen.c
+++ b/sunrpc/clnt_gen.c
@@ -45,9 +45,6 @@ CLIENT *
 clnt_create (const char *hostname, u_long prog, u_long vers,
 	     const char *proto)
 {
-  struct hostent hostbuf, *h;
-  size_t hstbuflen;
-  char *hsttmpbuf;
   struct protoent protobuf, *p;
   size_t prtbuflen;
   char *prttmpbuf;
@@ -56,7 +53,6 @@ clnt_create (const char *hostname, u_long prog, u_long vers,
   int sock;
   struct timeval tv;
   CLIENT *client;
-  int herr;
 
   if (strcmp (proto, "unix") == 0)
     {
@@ -78,37 +74,8 @@ clnt_create (const char *hostname, u_long prog, u_long vers,
       return client;
     }
 
-  hstbuflen = 1024;
-  hsttmpbuf = __alloca (hstbuflen);
-  while (__gethostbyname_r (hostname, &hostbuf, hsttmpbuf, hstbuflen,
-			    &h, &herr) != 0
-	 || h == NULL)
-    if (herr != NETDB_INTERNAL || errno != ERANGE)
-      {
-	get_rpc_createerr().cf_stat = RPC_UNKNOWNHOST;
-	return NULL;
-      }
-    else
-      {
-	/* Enlarge the buffer.  */
-	hstbuflen *= 2;
-	hsttmpbuf = __alloca (hstbuflen);
-      }
-
-  if (h->h_addrtype != AF_INET)
-    {
-      /*
-       * Only support INET for now
-       */
-      struct rpc_createerr *ce = &get_rpc_createerr ();
-      ce->cf_stat = RPC_SYSTEMERROR;
-      ce->cf_error.re_errno = EAFNOSUPPORT;
-      return NULL;
-    }
-  sin.sin_family = h->h_addrtype;
-  sin.sin_port = 0;
-  __bzero (sin.sin_zero, sizeof (sin.sin_zero));
-  memcpy ((char *) &sin.sin_addr, h->h_addr, h->h_length);
+  if (__libc_rpc_gethostbyname (hostname, &sin) != 0)
+    return NULL;
 
   prtbuflen = 1024;
   prttmpbuf = __alloca (prtbuflen);