Only propose decoding PPID 0 if that PPID is in the currently-selected frame.

(I used PPID 0xffffffff as an end-of-list marker so that PPID can no longer
be used in this dialog; if someone starts using that PPID then we'll have
to put a count of PPIDs in pinfo.)

svn path=/trunk/; revision=42991

3 files changed, 38 insertions, 35 deletions

diff --git a/epan/dissectors/packet-sctp.c b/epan/dissectors/packet-sctp.c
index 537b717457..e03bf4138f 100644
--- a/epan/dissectors/packet-sctp.c
+++ b/epan/dissectors/packet-sctp.c
@@ -2414,7 +2414,7 @@ fragment_reassembly(tvbuff_t *tvb, sctp_fragment* fragment,
                                      frag_i->frame_num, offset, offset + frag_i->len - 1, frag_i->len);
           offset += frag_i->len;
 
-	  mark_frame_as_depended_upon(pinfo, frag_i->frame_num);
+          mark_frame_as_depended_upon(pinfo, frag_i->frame_num);
         }
 
         for (frag_i = msg->fragments;
@@ -2426,7 +2426,7 @@ fragment_reassembly(tvbuff_t *tvb, sctp_fragment* fragment,
                                      frag_i->frame_num, offset, offset + frag_i->len - 1, frag_i->len);
           offset += frag_i->len;
 
-	  mark_frame_as_depended_upon(pinfo, frag_i->frame_num);
+          mark_frame_as_depended_upon(pinfo, frag_i->frame_num);
         }
       } else {
         for (frag_i = find_fragment(message->begin, stream_id, stream_seq_num);
@@ -2438,7 +2438,7 @@ fragment_reassembly(tvbuff_t *tvb, sctp_fragment* fragment,
                                      frag_i->frame_num, offset, offset + frag_i->len - 1, frag_i->len);
           offset += frag_i->len;
 
-	  mark_frame_as_depended_upon(pinfo, frag_i->frame_num);
+          mark_frame_as_depended_upon(pinfo, frag_i->frame_num);
         }
       }
 
@@ -2760,14 +2760,12 @@ dissect_data_chunk(tvbuff_t *chunk_tvb,
 
   payload_proto_id  = tvb_get_ntohl(chunk_tvb, DATA_CHUNK_PAYLOAD_PROTOCOL_ID_OFFSET);
 
-  /* insert the PPID in the pinfo structure if it is non-zero, not already there and there is still room */
-  if (payload_proto_id) {
-    for(number_of_ppid = 0; number_of_ppid < MAX_NUMBER_OF_PPIDS; number_of_ppid++)
-      if ((pinfo->ppids[number_of_ppid] == 0) || (pinfo->ppids[number_of_ppid] == payload_proto_id))
-        break;
-    if ((number_of_ppid < MAX_NUMBER_OF_PPIDS) && (pinfo->ppids[number_of_ppid] == 0))
-      pinfo->ppids[number_of_ppid] = payload_proto_id;
-  }
+  /* insert the PPID in the pinfo structure if it is not already there and there is still room */
+  for(number_of_ppid = 0; number_of_ppid < MAX_NUMBER_OF_PPIDS; number_of_ppid++)
+    if ((pinfo->ppids[number_of_ppid] == LAST_PPID) || (pinfo->ppids[number_of_ppid] == payload_proto_id))
+      break;
+  if ((number_of_ppid < MAX_NUMBER_OF_PPIDS) && (pinfo->ppids[number_of_ppid] == LAST_PPID))
+    pinfo->ppids[number_of_ppid] = payload_proto_id;
 
   e_bit = tvb_get_guint8(chunk_tvb, CHUNK_FLAGS_OFFSET) & SCTP_DATA_CHUNK_E_BIT;
   b_bit = tvb_get_guint8(chunk_tvb, CHUNK_FLAGS_OFFSET) & SCTP_DATA_CHUNK_B_BIT;
@@ -4019,6 +4017,7 @@ static void
 dissect_sctp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
   guint16 source_port, destination_port;
+  guint      number_of_ppid;
 
   /* Extract the common header */
   source_port      = tvb_get_ntohs(tvb, SOURCE_PORT_OFFSET);
@@ -4035,7 +4034,10 @@ dissect_sctp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
   /* Clear entries in Info column on summary display */
   col_set_str(pinfo->cinfo, COL_INFO, "");
 
-  memset(&pinfo->ppids, 0, sizeof(pinfo->ppids));
+
+  for(number_of_ppid = 0; number_of_ppid < MAX_NUMBER_OF_PPIDS; number_of_ppid++) {
+    pinfo->ppids[number_of_ppid] = LAST_PPID;
+  }
 
   /*  The tvb array in struct _sctp_info is huge: currently 2k pointers.
    *  We know (by the value of 'number_of_tvbs') which of these entries have
diff --git a/epan/packet_info.h b/epan/packet_info.h
index 49f444e76f..5a52555788 100644
--- a/epan/packet_info.h
+++ b/epan/packet_info.h
@@ -174,9 +174,11 @@ typedef struct _packet_info {
   gboolean gssapi_data_encrypted;
 
   guint32 ppid;  /* SCTP PPI of current DATA chunk */
+/* This is a valid PPID, but we use it to mark the end of the list */
+#define LAST_PPID 0xffffffff
   guint32 ppids[MAX_NUMBER_OF_PPIDS]; /* The first NUMBER_OF_PPIDS PPIDS which are present
-                                      * in the SCTP packet
-                                      */
+                                       * in the SCTP packet
+                                       */
   void    *private_data;	/* pointer to data passed from one dissector to another */
   GHashTable *private_table;	/* a hash table passed from one dissector to another */
   /* TODO: Use emem_strbuf_t instead */
diff --git a/ui/gtk/decode_as_dlg.c b/ui/gtk/decode_as_dlg.c
index 6af95d0c9e..9bba61eba0 100644
--- a/ui/gtk/decode_as_dlg.c
+++ b/ui/gtk/decode_as_dlg.c
@@ -1305,19 +1305,18 @@ decode_add_ppid_combo_box (GtkWidget *page)
 
     combo_box = ws_combo_box_new_text_and_pointer();
 
-    g_snprintf(tmp, sizeof(tmp), "PPID (%u)", 0);
-    ws_combo_box_append_text_and_pointer(GTK_COMBO_BOX(combo_box),
-                                         tmp, GINT_TO_POINTER(E_DECODE_PPID));
-    ws_combo_box_set_active(GTK_COMBO_BOX(combo_box), 0);  /* default */
-
     for(number_of_ppid = 0; number_of_ppid < MAX_NUMBER_OF_PPIDS; number_of_ppid++) {
-      if (cfile.edt->pi.ppids[number_of_ppid] != 0) {
-          g_snprintf(tmp, sizeof(tmp), "PPID (%u)", cfile.edt->pi.ppids[number_of_ppid]);
-          ws_combo_box_append_text_and_pointer(GTK_COMBO_BOX(combo_box),
-                                               tmp, GINT_TO_POINTER(E_DECODE_PPID + 1 + number_of_ppid));
-      } else
-          break;
+        if (cfile.edt->pi.ppids[number_of_ppid] != LAST_PPID) {
+            g_snprintf(tmp, sizeof(tmp), "PPID (%u)", cfile.edt->pi.ppids[number_of_ppid]);
+            ws_combo_box_append_text_and_pointer(GTK_COMBO_BOX(combo_box),
+                                                 tmp, GINT_TO_POINTER(E_DECODE_PPID + 1 + number_of_ppid));
+        } else
+            break;
     }
+
+    if (number_of_ppid)
+        ws_combo_box_set_active(GTK_COMBO_BOX(combo_box), 0);  /* default */
+
     g_object_set_data(G_OBJECT(page), E_COMBO_BOX_SRCDST, combo_box);
     return(combo_box);
 }
@@ -1703,18 +1702,18 @@ decode_sctp_update_ppid_combo_box(GtkWidget *w _U_, GtkWidget *page)
     sctp_combo_box = g_object_get_data(G_OBJECT(page), E_COMBO_BOX_SRCDST);
     ws_combo_box_clear_text_and_pointer(GTK_COMBO_BOX(sctp_combo_box));
 
-    g_snprintf(tmp, sizeof(tmp), "PPID (%u)", 0);
-    ws_combo_box_append_text_and_pointer(GTK_COMBO_BOX(sctp_combo_box), tmp, GINT_TO_POINTER(E_DECODE_PPID));
-    ws_combo_box_set_active(GTK_COMBO_BOX(sctp_combo_box), 0); /* default */
-
     for(number_of_ppid = 0; number_of_ppid < MAX_NUMBER_OF_PPIDS; number_of_ppid++) {
-      if (cfile.edt->pi.ppids[number_of_ppid] != 0) {
-        g_snprintf(tmp, sizeof(tmp), "PPID (%u)", cfile.edt->pi.ppids[number_of_ppid]);
-        ws_combo_box_append_text_and_pointer(GTK_COMBO_BOX(sctp_combo_box),
-                                             tmp, GINT_TO_POINTER(E_DECODE_PPID + 1 + number_of_ppid));
-      }
+        if (cfile.edt->pi.ppids[number_of_ppid] != LAST_PPID) {
+            g_snprintf(tmp, sizeof(tmp), "PPID (%u)", cfile.edt->pi.ppids[number_of_ppid]);
+            ws_combo_box_append_text_and_pointer(GTK_COMBO_BOX(sctp_combo_box),
+                                                 tmp, GINT_TO_POINTER(E_DECODE_PPID + 1 + number_of_ppid));
+        } else
+            break;
     }
 
+    if (number_of_ppid)
+        ws_combo_box_set_active(GTK_COMBO_BOX(sctp_combo_box), 0); /* default */
+
     g_object_set_data(G_OBJECT(page), E_PAGE_TABLE, "sctp.ppi");
 
     sctp_store = g_object_get_data(G_OBJECT(G_OBJECT(decode_w)), "sctp_data");
@@ -1977,7 +1976,7 @@ decode_as_cb (GtkWidget * w _U_, gpointer user_data _U_)
     GTK_WIDGET_SET_FLAGS(button, GTK_CAN_DEFAULT);
 #endif
     gtk_box_pack_start(GTK_BOX(button_vb), button, FALSE, FALSE, 0);
-	gtk_widget_set_tooltip_text(button, "Open a dialog showing the current settings.\n" 
+	gtk_widget_set_tooltip_text(button, "Open a dialog showing the current settings.\n"
 		"Note you need to select and press apply first to be able to save the current setting");
 
     button = gtk_button_new_from_stock(GTK_STOCK_CLEAR);