nfs-utils: add and use nfs_authsys_create

The current mount, umount and showmount code uses
authunix_create_default to get an auth handle. The one provided by glibc
returned a truncated list of groups when there were more than 16 groups.
libtirpc however currently does an abort() in this case, which causes
the program to crash and dump core.

nfs-utils just uses these auth handles for the MNT protocol, so the
group list doesn't make a lot of difference here. Add a new function
that creates an auth handle with a supplemental gids list that consists
only of the primary gid. Have nfs-utils use that function anywhere that
it currently uses authunix_create_default. Also, have the caller
properly check for a NULL return from that function.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/support/include/nfsrpc.h b/support/include/nfsrpc.h
index 4db35abf8d1a1df32c81db758c7cfc7b5f43968f..6ebefcac530ba1b55ea2a3d192d96e889b15d2e7 100644 (file)
--- a/support/include/nfsrpc.h
+++ b/support/include/nfsrpc.h
@@ -160,4 +160,7 @@ extern int          nfs_rpc_ping(const struct sockaddr *sap,
                                const unsigned short protocol,
                                const struct timeval *timeout);
 
+/* create AUTH_SYS handle with no supplemental groups */
+extern AUTH *                   nfs_authsys_create(void);
+
 #endif /* !__NFS_UTILS_NFSRPC_H */

diff --git a/support/nfs/rpc_socket.c b/support/nfs/rpc_socket.c
index 0e20824cb614e4a23e69799a05a52adbdce6b58b..aa6a2055772a2fe2f178be8340fe2f6b1683b2c8 100644 (file)
--- a/support/nfs/rpc_socket.c
+++ b/support/nfs/rpc_socket.c
@@ -557,3 +557,24 @@ rpcprog_t nfs_getrpcbyname(const rpcprog_t program, const char *table[])
 
        return program;
 }
+
+/*
+ * AUTH_SYS doesn't allow more than 16 gids in the supplemental group list.
+ * If there are more than that, trying to determine which ones to include
+ * in the list is problematic. This function creates an auth handle that
+ * only has the primary gid in the supplemental gids list. It's intended to
+ * be used for protocols where credentials really don't matter much (the MNT
+ * protocol, for instance).
+ */
+AUTH *
+nfs_authsys_create(void)
+{
+       char machname[MAXHOSTNAMELEN + 1];
+       uid_t   uid = geteuid();
+       gid_t   gid = getegid();
+
+       if (gethostname(machname, sizeof(machname)) == -1)
+               return NULL;
+
+       return authsys_create(machname, uid, gid, 1, &gid);
+}

diff --git a/utils/mount/network.c b/utils/mount/network.c
index 8dc183a16e78983ef8fcf8f79506275b1c635763..c5412574a1e2b1b642d3a52ce656e1aec941f5a4 100644 (file)
--- a/utils/mount/network.c
+++ b/utils/mount/network.c
@@ -857,7 +857,14 @@ int nfs_advise_umount(const struct sockaddr *sap, const socklen_t salen,
                return 0;
        }
 
-       client->cl_auth = authunix_create_default();
+       client->cl_auth = nfs_authsys_create();
+       if (client->cl_auth == NULL) {
+               if (verbose)
+                       nfs_error(_("%s: Failed to create RPC auth handle"),
+                               progname);
+               CLNT_DESTROY(client);
+               return 0;
+       }
 
        res = CLNT_CALL(client, MOUNTPROC_UMNT,
                        (xdrproc_t)xdr_dirpath, (caddr_t)argp,
@@ -957,8 +964,10 @@ CLIENT *mnt_openclnt(clnt_addr_t *mnt_server, int *msock)
        }
        if (clnt) {
                /* try to mount hostname:dirname */
-               clnt->cl_auth = authunix_create_default();
-               return clnt;
+               clnt->cl_auth = nfs_authsys_create();
+               if (clnt->cl_auth)
+                       return clnt;
+               CLNT_DESTROY(clnt);
        }
        return NULL;
 }

diff --git a/utils/showmount/showmount.c b/utils/showmount/showmount.c
index f567093c7dafd8a6afa34ab894ed028b8833984c..394f5284a219d04c134fe54d59dfb40150925fc1 100644 (file)
--- a/utils/showmount/showmount.c
+++ b/utils/showmount/showmount.c
@@ -194,7 +194,13 @@ int main(int argc, char **argv)
        }
 
        mclient = nfs_get_mount_client(hostname, mount_vers_tbl[vers]);
-       mclient->cl_auth = authunix_create_default();
+       mclient->cl_auth = nfs_authsys_create();
+       if (mclient->cl_auth == NULL) {
+               fprintf(stderr, "%s: unable to create RPC auth handle.\n",
+                               program_name);
+               clnt_destroy(mclient);
+               exit(1);
+       }
        total_timeout.tv_sec = TOTAL_TIMEOUT;
        total_timeout.tv_usec = 0;