Fix Decode As for protocols that may use tunneling.

Dissectors that rely on pinfo structure information may have the
data overwritten if the data is tunneled.  Address it by using
proto data that is based on pinfo->curr_layer_num.

Bug: 13746
Change-Id: I1c29f26a3c49f368876f0e96908705bc9c099ce1
Reviewed-on: https://code.wireshark.org/review/21559
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
Reviewed-by: Michael Mann <mmann78@netscape.net>

1 files changed, 17 insertions, 13 deletions

diff --git a/epan/dissectors/packet-sctp.c b/epan/dissectors/packet-sctp.c
index 7b150a5ba6..11ee2e85d4 100644
--- a/epan/dissectors/packet-sctp.c
+++ b/epan/dissectors/packet-sctp.c
@@ -740,40 +740,44 @@ find_assoc_index(assoc_info_t* tmpinfo, gboolean visited)
 static void
 sctp_src_prompt(packet_info *pinfo, gchar *result)
 {
-    g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "source (%s%u)", UTF8_RIGHTWARDS_ARROW, pinfo->srcport);
+    guint32 port = GPOINTER_TO_UINT(p_get_proto_data(pinfo->pool, pinfo, hf_source_port, pinfo->curr_layer_num));
+
+    g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "source (%s%u)", UTF8_RIGHTWARDS_ARROW, port);
 }
 
 static gpointer
 sctp_src_value(packet_info *pinfo)
 {
-    return GUINT_TO_POINTER(pinfo->srcport);
+    return p_get_proto_data(pinfo->pool, pinfo, hf_source_port, pinfo->curr_layer_num);
 }
 
 static void
 sctp_dst_prompt(packet_info *pinfo, gchar *result)
 {
-    g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "destination (%s%u)", UTF8_RIGHTWARDS_ARROW, pinfo->destport);
+    guint32 port = GPOINTER_TO_UINT(p_get_proto_data(pinfo->pool, pinfo, hf_destination_port, pinfo->curr_layer_num));
+
+    g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "destination (%s%u)", UTF8_RIGHTWARDS_ARROW, port);
 }
 
 static gpointer
 sctp_dst_value(packet_info *pinfo)
 {
-    return GUINT_TO_POINTER(pinfo->destport);
+    return p_get_proto_data(pinfo->pool, pinfo, hf_destination_port, pinfo->curr_layer_num);
 }
 
 static void
 sctp_both_prompt(packet_info *pinfo, gchar *result)
 {
-    g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "both (%u%s%u)", pinfo->srcport, UTF8_LEFT_RIGHT_ARROW, pinfo->destport);
+    guint32 srcport = GPOINTER_TO_UINT(p_get_proto_data(pinfo->pool, pinfo, hf_source_port, pinfo->curr_layer_num)),
+            destport = GPOINTER_TO_UINT(p_get_proto_data(pinfo->pool, pinfo, hf_destination_port, pinfo->curr_layer_num));
+
+    g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "both (%u%s%u)", srcport, UTF8_LEFT_RIGHT_ARROW, destport);
 }
 
 static void
 sctp_ppi_prompt1(packet_info *pinfo _U_, gchar* result)
 {
-    guint32 ppid;
-    void *tmp = p_get_proto_data(pinfo->pool, pinfo, proto_sctp, 0);
-
-    ppid = GPOINTER_TO_UINT(tmp);
+    guint32 ppid = GPOINTER_TO_UINT(p_get_proto_data(pinfo->pool, pinfo, proto_sctp, 0));
 
     if (ppid == LAST_PPID) {
         g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "PPID (none)");
@@ -785,10 +789,7 @@ sctp_ppi_prompt1(packet_info *pinfo _U_, gchar* result)
 static void
 sctp_ppi_prompt2(packet_info *pinfo _U_, gchar* result)
 {
-    guint32 ppid;
-    void *tmp = p_get_proto_data(pinfo->pool, pinfo, proto_sctp, 1);
-
-    ppid = GPOINTER_TO_UINT(tmp);
+    guint32 ppid = GPOINTER_TO_UINT(p_get_proto_data(pinfo->pool, pinfo, proto_sctp, 1));
 
     if (ppid == LAST_PPID) {
         g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "PPID (none)");
@@ -4783,6 +4784,9 @@ dissect_sctp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_
   set_address(&sctp_info.ip_src, pinfo->src.type, pinfo->src.len, pinfo->src.data);
   set_address(&sctp_info.ip_dst, pinfo->dst.type, pinfo->dst.len, pinfo->dst.data);
 
+  p_add_proto_data(pinfo->pool, pinfo, hf_source_port, pinfo->curr_layer_num, GUINT_TO_POINTER(pinfo->srcport));
+  p_add_proto_data(pinfo->pool, pinfo, hf_destination_port, pinfo->curr_layer_num, GUINT_TO_POINTER(pinfo->destport));
+
   dissect_sctp_packet(tvb, pinfo, tree, FALSE);
   if (!pinfo->flags.in_error_pkt && sctp_info.number_of_tvbs > 0)
     tap_queue_packet(sctp_tap, pinfo, &sctp_info);