Require dissectors for all ONC RPC calls and replies.

Either there's a known body for the call or reply, in which case we
already have a dissector for it, or the body is empty, in which case we
now have dissect_rpc_void() to dissect it, or the body is unknown or
nobody's bothered writing it, in which case we use dissect_rpc_unknown()
for now.

This means that an attempt to look up the dissector for a known
procedure will always succeed, so we can label it with the name rather
than with "proc-N".

It also means that we distinguish between "it's void" and "it's
unknown", so that unknown values will get flagged as such.

Change-Id: I748580c1dca61d1f0972396db1a3b0885fc0a541
Reviewed-on: https://code.wireshark.org/review/9699
Reviewed-by: Guy Harris <guy@alum.mit.edu>

1 files changed, 28 insertions, 25 deletions

diff --git a/epan/dissectors/packet-mount.c b/epan/dissectors/packet-mount.c
index 3ffdeba210..988c1aa11d 100644
--- a/epan/dissectors/packet-mount.c
+++ b/epan/dissectors/packet-mount.c
@@ -670,23 +670,23 @@ dissect_mount_statvfs_reply(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *t
 }
 
 /* proc number, "proc name", dissect_request, dissect_reply */
-/* NULL as function pointer means: type of arguments is "void". */
 
 /* Mount protocol version 1, RFC 1094 */
 static const vsff mount1_proc[] = {
-	{ 0, "NULL", NULL, NULL },
+	{ 0, "NULL",
+	  dissect_rpc_void, dissect_rpc_void },
 	{ MOUNTPROC_MNT,        "MNT",
 	  dissect_mount_dirpath_call, dissect_mount1_mnt_reply },
 	{ MOUNTPROC_DUMP,       "DUMP",
-	  NULL, dissect_mount_dump_reply },
+	  dissect_rpc_void, dissect_mount_dump_reply },
 	{ MOUNTPROC_UMNT,      "UMNT",
-	  dissect_mount_dirpath_call, NULL },
+	  dissect_mount_dirpath_call, dissect_rpc_void },
 	{ MOUNTPROC_UMNTALL,   "UMNTALL",
-	  NULL, NULL },
+	  dissect_rpc_void, dissect_rpc_void },
 	{ MOUNTPROC_EXPORT,    "EXPORT",
-	  NULL, dissect_mount_export_reply },
+	  dissect_rpc_void, dissect_mount_export_reply },
 	{ MOUNTPROC_EXPORTALL, "EXPORTALL",
-	  NULL, dissect_mount_export_reply },
+	  dissect_rpc_void, dissect_mount_export_reply },
 	{ 0, NULL, NULL, NULL }
 };
 static const value_string mount1_proc_vals[] = {
@@ -706,19 +706,20 @@ static const value_string mount1_proc_vals[] = {
    mount V2 is V1 plus MOUNTPROC_PATHCONF to fetch information for the
    POSIX "pathconf()" call. */
 static const vsff mount2_proc[] = {
-	{ 0, "NULL", NULL, NULL },
+	{ 0,                    "NULL",
+	  dissect_rpc_void, dissect_rpc_void },
 	{ MOUNTPROC_MNT,        "MNT",
 	  dissect_mount_dirpath_call, dissect_mount1_mnt_reply },
 	{ MOUNTPROC_DUMP,       "DUMP",
-	  NULL, dissect_mount_dump_reply },
+	  dissect_rpc_void, dissect_mount_dump_reply },
 	{ MOUNTPROC_UMNT,      "UMNT",
-	  dissect_mount_dirpath_call, NULL },
+	  dissect_mount_dirpath_call, dissect_rpc_void },
 	{ MOUNTPROC_UMNTALL,   "UMNTALL",
-	  NULL, NULL },
+	  dissect_rpc_void, dissect_rpc_void },
 	{ MOUNTPROC_EXPORT,    "EXPORT",
-	  NULL, dissect_mount_export_reply },
+	  dissect_rpc_void, dissect_mount_export_reply },
 	{ MOUNTPROC_EXPORTALL, "EXPORTALL",
-	  NULL, dissect_mount_export_reply },
+	  dissect_rpc_void, dissect_mount_export_reply },
 	{ MOUNTPROC_PATHCONF,  "PATHCONF",
 	  dissect_mount_dirpath_call, dissect_mount_pathconf_reply },
 	{ 0, NULL, NULL, NULL }
@@ -739,17 +740,18 @@ static const value_string mount2_proc_vals[] = {
 
 /* Mount protocol version 3, RFC 1813 */
 static const vsff mount3_proc[] = {
-	{ 0, "NULL", NULL, NULL },
+	{ 0, "NULL",
+		dissect_rpc_void, dissect_rpc_void },
 	{ MOUNTPROC_MNT, "MNT",
 		dissect_mount_dirpath_call, dissect_mount3_mnt_reply },
 	{ MOUNTPROC_DUMP, "DUMP",
-		NULL, dissect_mount_dump_reply },
+		dissect_rpc_void, dissect_mount_dump_reply },
 	{ MOUNTPROC_UMNT, "UMNT",
-		dissect_mount_dirpath_call, NULL },
+		dissect_mount_dirpath_call, dissect_rpc_void },
 	{ MOUNTPROC_UMNTALL, "UMNTALL",
-		NULL, NULL },
+		dissect_rpc_void, dissect_rpc_void },
 	{ MOUNTPROC_EXPORT, "EXPORT",
-		NULL, dissect_mount_export_reply },
+		dissect_rpc_void, dissect_mount_export_reply },
 	{ 0, NULL, NULL, NULL }
 };
 static const value_string mount3_proc_vals[] = {
@@ -767,21 +769,22 @@ static const value_string mount3_proc_vals[] = {
    MOUNTPROC_EXPORTLIST and MOUNTPROC_STATVFS */
 
 static const vsff sgi_mount1_proc[] = {
-	{ 0, "NULL", NULL, NULL },
+	{ 0, "NULL",
+	  dissect_rpc_void, dissect_rpc_void },
 	{ MOUNTPROC_MNT,        "MNT",
 	  dissect_mount_dirpath_call, dissect_mount1_mnt_reply },
 	{ MOUNTPROC_DUMP,       "DUMP",
-	  NULL, dissect_mount_dump_reply },
+	  dissect_rpc_void, dissect_mount_dump_reply },
 	{ MOUNTPROC_UMNT,      "UMNT",
-	  dissect_mount_dirpath_call, NULL },
+	  dissect_mount_dirpath_call, dissect_rpc_void },
 	{ MOUNTPROC_UMNTALL,   "UMNTALL",
-	  NULL, NULL },
+	  dissect_rpc_void, dissect_rpc_void },
 	{ MOUNTPROC_EXPORT,    "EXPORT",
-	  NULL, dissect_mount_export_reply },
+	  dissect_rpc_void, dissect_mount_export_reply },
 	{ MOUNTPROC_EXPORTALL, "EXPORTALL",
-	  NULL, dissect_mount_export_reply },
+	  dissect_rpc_void, dissect_mount_export_reply },
 	{ MOUNTPROC_EXPORTLIST,"EXPORTLIST",
-	  NULL, dissect_mount_exportlist_reply },
+	  dissect_rpc_void, dissect_mount_exportlist_reply },
 	{ MOUNTPROC_STATVFS,   "STATVFS",
 	  dissect_mount_dirpath_call, dissect_mount_statvfs_reply },
 	{ 0, NULL, NULL, NULL }