[PATCH] mount.nfs: Don't fail mounts when /etc/netconfig is nonexistent

[Steve Dickson <SteveD@redhat.com>]

During some recent testing, mounts were mysteriously failing to some 
servers but not to others. The mounts that were failure were in a very sparse 
environment. Meaning very little in any supporting utilities, like
/bin/cat, /bin/ls or system-wide configuration files.

The reason the mounts were failing was /etc/netconfig did not exist. 
Even in the cases when all the information that would have been pulled
from /etc/netconfig already existed or was easily attainable 

So the patch tries to recover from when system files are inaccessible 
and the need information already exists or is well known. 
 
steved.

Author: Steve Dickson <steved@redhat.com>
Date:   Wed Jan 27 11:19:00 2010 -0500
    
    In a very sparse environments certain system files (like
    /etc/netconfig) may not exist. In these environments don't
    fail mount if all the need information (like network protocols)
    exist and are well known.
    
    Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/support/nfs/getport.c b/support/nfs/getport.c
index c930539..e490dd4 100644
--- a/support/nfs/getport.c
+++ b/support/nfs/getport.c
@@ -277,7 +277,7 @@ nfs_get_proto(const char *netid, sa_family_t *family, unsigned long *protocol)
 #ifdef HAVE_LIBTIRPC
 char *nfs_get_netid(const sa_family_t family, const unsigned long protocol)
 {
-	char *nc_protofmly, *nc_proto, *nc_netid;
+	char *nc_protofmly, *nc_proto, *nc_netid = NULL;
 	struct netconfig *nconf;
 	struct protoent *proto;
 	void *handle;
@@ -319,6 +319,19 @@ char *nfs_get_netid(const sa_family_t family, const unsigned long protocol)
 	endnetconfig(handle);
 
 out:
+	/*
+	 * The system configuration files are inaccessible 
+	 * so see if these are well known protocols
+	 */
+	if (protocol == IPPROTO_TCP)
+		nc_netid = (family == AF_INET6 ? 
+			strdup("tcp6") : strdup("tcp"));
+	else if (protocol == IPPROTO_UDP)
+		nc_netid = (family == AF_INET6 ? 
+			strdup("udp6") : strdup("udp"));
+	if (nc_netid != NULL)
+		return nc_netid;
+
 	rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
 	return NULL;
 }
diff --git a/utils/mount/network.c b/utils/mount/network.c
index 06cab6a..fa99bc1 100644
--- a/utils/mount/network.c
+++ b/utils/mount/network.c
@@ -1270,7 +1270,26 @@ nfs_nfs_version(struct mount_options *options, unsigned long *version)
 	*version = 0;
 	return 1;
 }
-
+/*
+ * Returns TRUE if the option string is a well known protocol
+ */
+int 
+nfs_set_proto(char *option,  unsigned long *protocol)
+{
+	if (strcmp(option, "tcp") == 0 || 
+			strcmp(option, "tcp6") == 0) {
+		*protocol = IPPROTO_TCP;
+		return 1;
+	}
+	if (strcmp(option, "udp") == 0 ||
+			strcmp(option, "udp6") == 0) {
+		*protocol = IPPROTO_UDP;
+		return 1;
+	}
+	if (verbose)
+		nfs_error(_("%s: unkown protocol: '%s'"), progname, option);
+	return 0;
+}
 /*
  * Returns TRUE if @protocol contains a valid value for this option,
  * or FALSE if the option was specified with an invalid value.
@@ -1290,8 +1309,13 @@ nfs_nfs_protocol(struct mount_options *options, unsigned long *protocol)
 		return 1;
 	case 2: /* proto */
 		option = po_get(options, "proto");
-		if (option != NULL)
-			return nfs_get_proto(option, &family, protocol);
+		if (option != NULL) {
+			if (nfs_get_proto(option, &family, protocol))
+				return 1;
+			if (nfs_set_proto(option, protocol))
+				return 1;
+			return 0;
+		}
 	}
 
 	/*
@@ -1438,8 +1462,13 @@ nfs_mount_protocol(struct mount_options *options, unsigned long *protocol)
 	char *option;
 
 	option = po_get(options, "mountproto");
-	if (option != NULL)
-		return nfs_get_proto(option, &family, protocol);
+	if (option != NULL) {
+		if (nfs_get_proto(option, &family, protocol))
+			return 1;
+		if (nfs_set_proto(option, protocol))
+			return 1;
+		return 0;
+	}
 
 	/*
 	 * MNT transport protocol wasn't specified.  If the NFS