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, 1 deletions

diff --git a/sunrpc/Makefile b/sunrpc/Makefile
index da6dffac39..f7c593aab5 100644
--- a/sunrpc/Makefile
+++ b/sunrpc/Makefile
@@ -78,7 +78,8 @@ routines := auth_none authuxprot bindrsvprt clnt_raw clnt_simp \
 	    des_crypt des_impl des_soft key_prot openchild rtime svcauth_des \
 	    getrpcent getrpcbyname getrpcbynumber \
 	    getrpcent_r getrpcbyname_r getrpcbynumber_r \
-	    clnt_unix svc_unix create_xid $(need-export-routines)
+	    clnt_unix svc_unix create_xid $(need-export-routines) \
+	    rpc_gethostbyname
 ifneq ($(link-obsolete-rpc),yes)
 # We only add the RPC for compatibility to libc.so.
 shared-only-routines = $(routines)