If the VCI and payload type indicate that a cell is an OAM cell, dissect

it as such.

Clear the Info column when dissecting cells for an AAL we handle before
dissecting the cell, and set the Info column for OAM cells.

svn path=/trunk/; revision=13222

1 files changed, 30 insertions, 2 deletions

diff --git a/epan/dissectors/packet-atm.c b/epan/dissectors/packet-atm.c
index 820643c62e..a87207d575 100644
--- a/epan/dissectors/packet-atm.c
+++ b/epan/dissectors/packet-atm.c
@@ -1332,6 +1332,8 @@ dissect_atm_cell(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
   int          err;
   guint8       vpi;
   guint16      vci;
+  guint8       pt;
+  guint8       aal;
   guint16      aal3_4_hdr, aal3_4_trlr;
   guint16      oam_crc;
   gint         length;
@@ -1350,8 +1352,9 @@ dissect_atm_cell(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
   octet = tvb_get_guint8(tvb, 3);
   vci |= octet >> 4;
   proto_tree_add_uint(atm_tree, hf_atm_vci, tvb, 1, 3, vci);
+  pt = (octet >> 1) & 0x7;
   proto_tree_add_text(atm_tree, tvb, 3, 1, "Payload Type: %s",
-        val_to_str((octet >> 1) & 0x7, pt_vals, "Unknown (%u)"));
+        val_to_str(pt, pt_vals, "Unknown (%u)"));
   proto_tree_add_text(atm_tree, tvb, 3, 1, "Cell Loss Priority: %s",
 	(octet & 0x01) ? "Low priority" : "High priority");
   ti = proto_tree_add_text(atm_tree, tvb, 4, 1, "Header Error Check: 0x%02x",
@@ -1365,11 +1368,29 @@ dissect_atm_cell(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
     proto_item_append_text(ti, " (error in bit %d)", err);
   offset = 5;
 
-  switch (pinfo->pseudo_header->atm.aal) {
+  /*
+   * Check for OAM cells.
+   * XXX - do this for all AAL values, overriding whatever information
+   * Wiretap got from the file?
+   */
+  aal = pinfo->pseudo_header->atm.aal;
+  if (aal == AAL_USER) {
+	/*
+	 * OAM F4 is VCI 3 or 4 and PT 0X0.
+	 * OAM F5 is PT 10X.
+	 */
+	if (((vci == 3 || vci == 4) && ((pt & 0x5) == 0)) ||
+	    ((pt & 0x6) == 0x4))
+		aal = AAL_OAMCELL;
+  }
+
+  switch (aal) {
 
   case AAL_1:
     if (check_col(pinfo->cinfo, COL_PROTOCOL))
       col_set_str(pinfo->cinfo, COL_PROTOCOL, "AAL1");
+    if (check_col(pinfo->cinfo, COL_INFO))
+      col_clear(pinfo->cinfo, COL_INFO);
     ti = proto_tree_add_item(tree, proto_aal1, tvb, offset, -1, FALSE);
     aal_tree = proto_item_add_subtree(ti, ett_aal1);
     octet = tvb_get_guint8(tvb, offset);
@@ -1395,6 +1416,8 @@ dissect_atm_cell(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
      */
     if (check_col(pinfo->cinfo, COL_PROTOCOL))
       col_set_str(pinfo->cinfo, COL_PROTOCOL, "AAL3/4");
+    if (check_col(pinfo->cinfo, COL_INFO))
+      col_clear(pinfo->cinfo, COL_INFO);
     ti = proto_tree_add_item(tree, proto_aal3_4, tvb, offset, -1, FALSE);
     aal_tree = proto_item_add_subtree(ti, ett_aal3_4);
     aal3_4_hdr = tvb_get_ntohs(tvb, offset);
@@ -1428,9 +1451,14 @@ dissect_atm_cell(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
   case AAL_OAMCELL:
     if (check_col(pinfo->cinfo, COL_PROTOCOL))
       col_set_str(pinfo->cinfo, COL_PROTOCOL, "OAM AAL");
+    if (check_col(pinfo->cinfo, COL_INFO))
+      col_clear(pinfo->cinfo, COL_INFO);
     ti = proto_tree_add_item(tree, proto_oamaal, tvb, offset, -1, FALSE);
     aal_tree = proto_item_add_subtree(ti, ett_oamaal);
     octet = tvb_get_guint8(tvb, offset);
+    if (check_col(pinfo->cinfo, COL_INFO))
+      col_add_fstr(pinfo->cinfo, COL_INFO, "%s",
+		val_to_str(octet >> 4, oam_type_vals, "Unknown (%u)"));
     proto_tree_add_text(aal_tree, tvb, offset, 1, "OAM Type: %s",
 		val_to_str(octet >> 4, oam_type_vals, "Unknown (%u)"));
     switch (octet >> 4) {