Pull the handling of trailers in Ethernet (as opposed to 802.3) frames

into "ethertype()".

svn path=/trunk/; revision=2915

7 files changed, 142 insertions, 185 deletions

diff --git a/epan/packet.h b/epan/packet.h
index 6b5f55e130..f472ea9d39 100644
--- a/epan/packet.h
+++ b/epan/packet.h
@@ -1,7 +1,7 @@
 /* packet.h
  * Definitions for packet disassembly structures and routines
  *
- * $Id: packet.h,v 1.19 2001/01/13 06:34:33 guy Exp $
+ * $Id: packet.h,v 1.20 2001/01/18 07:44:41 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -363,12 +363,12 @@ void old_dissect_data(const u_char *, int, frame_data *, proto_tree *);
 void dissect_data(tvbuff_t *tvb, int, packet_info *pinfo, proto_tree *tree);
 
 
-/* These functions are in ethertype.c */
+/* These functions are in packet-ethertype.c */
 void capture_ethertype(guint16 etype, int offset,
 		const u_char *pd, packet_counts *ld);
-guint ethertype(guint16 etype, tvbuff_t*, int offset_after_ethertype,
-		packet_info *pinfo, proto_tree *tree,
-		proto_tree *fh_tree, int item_id);
+void ethertype(guint16 etype, tvbuff_t *tvb, int offset_after_ethertype,
+		packet_info *pinfo, proto_tree *tree, proto_tree *fh_tree,
+		int etype_id, int trailer_id);
 extern const value_string etype_vals[];
 
 /* ipproto.c */
diff --git a/packet-eth.c b/packet-eth.c
index 0370982d27..8051248e6d 100644
--- a/packet-eth.c
+++ b/packet-eth.c
@@ -1,7 +1,7 @@
 /* packet-eth.c
  * Routines for ethernet packet disassembly
  *
- * $Id: packet-eth.c,v 1.55 2001/01/09 09:59:28 guy Exp $
+ * $Id: packet-eth.c,v 1.56 2001/01/18 07:44:39 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -150,14 +150,13 @@ dissect_eth(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
   guint8		*dst, *src;
   const guint8		*pd;
 
-  volatile guint16	etype;
+  guint16		etype;
   volatile int		ethhdr_type;	/* the type of Ethernet frame */
-  volatile int		eth_offset;
+  int			eth_offset;
   volatile guint16  	length;
   tvbuff_t		*volatile next_tvb;
   tvbuff_t		*volatile trailer_tvb;
   proto_tree		*volatile fh_tree;
-  guint			length_before;
 
   CHECK_DISPLAY_AS_DATA(proto_eth, tvb, pinfo, tree);
 
@@ -218,20 +217,19 @@ dissect_eth(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 		(ethhdr_type == ETHERNET_802_3 ? "Raw " : ""));
     }
     if (tree) {
-
-	ti = proto_tree_add_protocol_format(tree, proto_eth, tvb, 0, ETH_HEADER_SIZE,
+      ti = proto_tree_add_protocol_format(tree, proto_eth, tvb, 0, ETH_HEADER_SIZE,
 		"IEEE 802.3 %s", (ethhdr_type == ETHERNET_802_3 ? "Raw " : ""));
 
-	fh_tree = proto_item_add_subtree(ti, ett_ieee8023);
+      fh_tree = proto_item_add_subtree(ti, ett_ieee8023);
 
-	proto_tree_add_ether(fh_tree, hf_eth_dst, tvb, 0, 6, dst);
-	proto_tree_add_ether(fh_tree, hf_eth_src, tvb, 6, 6, src);
+      proto_tree_add_ether(fh_tree, hf_eth_dst, tvb, 0, 6, dst);
+      proto_tree_add_ether(fh_tree, hf_eth_src, tvb, 6, 6, src);
 
 /* add items for eth.addr filter */
-	proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 0, 6, dst);
-	proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 6, 6, src);
+      proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 0, 6, dst);
+      proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 6, 6, src);
 
-	proto_tree_add_uint(fh_tree, hf_eth_len, tvb, 12, 2, length);
+      proto_tree_add_uint(fh_tree, hf_eth_len, tvb, 12, 2, length);
     }
 
     /* Convert the LLC length from the 802.3 header to a total
@@ -247,99 +245,78 @@ dissect_eth(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
       pinfo->len = length;
     if (pinfo->captured_len > length)
       pinfo->captured_len = length;
+
+    /* Give the next dissector only 'length' number of bytes */
+    TRY {
+      next_tvb = tvb_new_subset(tvb, ETH_HEADER_SIZE, etype, etype);
+      trailer_tvb = tvb_new_subset(tvb, ETH_HEADER_SIZE + etype, -1, -1);
+    }
+    CATCH2(BoundsError, ReportedBoundsError) {
+      /* Either:
+
+	    the packet doesn't have "etype" bytes worth of
+	    captured data left in it - or it may not even have
+	    "etype" bytes worth of data in it, period -
+	    so the "tvb_new_subset()" creating "next_tvb"
+	    threw an exception
+
+	 or
+
+	    the packet has exactly "etype" bytes worth of
+	    captured data left in it, so the "tvb_new_subset()"
+	    creating "trailer_tvb" threw an exception.
+
+	 In either case, this means that all the data in the frame
+	 is within the length value, so we give all the data to the
+	 next protocol and have no trailer. */
+      next_tvb = tvb_new_subset(tvb, ETH_HEADER_SIZE, -1, etype);
+      trailer_tvb = NULL;
+    }
+    ENDTRY;
+
+    /* Dissect the payload either as IPX or as an LLC frame. */
+    switch (ethhdr_type) {
+      case ETHERNET_802_3:
+        call_dissector(ipx_handle, next_tvb, pinfo, tree);
+        break;
+      case ETHERNET_802_2:
+        call_dissector(llc_handle, next_tvb, pinfo, tree);
+        break;
+    }
+
+    /* If there's some bytes left over, mark them. */
+    if (trailer_tvb && tree) {
+      guint trailer_length;
+
+      trailer_length = tvb_length(trailer_tvb);
+      if (trailer_length != 0) {
+	proto_tree_add_item(fh_tree, hf_eth_trailer, trailer_tvb, 0,
+			    trailer_length, FALSE);
+      }
+    }
   } else {
     ethhdr_type = ETHERNET_II;
     if (check_col(pinfo->fd, COL_INFO))
       col_set_str(pinfo->fd, COL_INFO, "Ethernet II");
     if (tree) {
-
-	ti = proto_tree_add_protocol_format(tree, proto_eth, tvb, 0, ETH_HEADER_SIZE,
+      ti = proto_tree_add_protocol_format(tree, proto_eth, tvb, 0, ETH_HEADER_SIZE,
 		"Ethernet II");
 
-	fh_tree = proto_item_add_subtree(ti, ett_ether2);
+      fh_tree = proto_item_add_subtree(ti, ett_ether2);
 
-	proto_tree_add_ether(fh_tree, hf_eth_dst, tvb, 0, 6, dst);
-	proto_tree_add_ether(fh_tree, hf_eth_src, tvb, 6, 6, src);
+      proto_tree_add_ether(fh_tree, hf_eth_dst, tvb, 0, 6, dst);
+      proto_tree_add_ether(fh_tree, hf_eth_src, tvb, 6, 6, src);
 /* add items for eth.addr filter */
-	proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 0, 6, dst);
-	proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 6, 6, src);
+      proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 0, 6, dst);
+      proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 6, 6, src);
     }
-  }
-  eth_offset += ETH_HEADER_SIZE;
-
-  if (etype <= IEEE_802_3_MAX_LEN) {
-	  /* Give the next dissector only 'length' number of bytes */
-	  TRY {
-	    next_tvb = tvb_new_subset(tvb, ETH_HEADER_SIZE, etype, etype);
-	    trailer_tvb = tvb_new_subset(tvb, ETH_HEADER_SIZE + etype, -1, -1);
-	  }
-	  CATCH2(BoundsError, ReportedBoundsError) {
-	    /* Either:
-
-		 the packet doesn't have "etype" bytes worth of
-		 captured data left in it - or it may not even have
-		 "etype" bytes worth of data in it, period -
-		 so the "tvb_new_subset()" creating "next_tvb"
-		 threw an exception
-
-	       or
-
-		 the packet has exactly "etype" bytes worth of
-		 captured data left in it, so the "tvb_new_subset()"
-		 creating "trailer_tvb" threw an exception.
-
-	      In either case, this means that all the data in the frame
-	      is within the length value, so we give all the data to the
-	      next protocol and have no trailer. */
-	    next_tvb = tvb_new_subset(tvb, ETH_HEADER_SIZE, -1, etype);
-	    trailer_tvb = NULL;
-	  }
-	  ENDTRY;
-  }
-  else {
-     next_tvb = NULL;	/* "ethertype()" will create the next tvb for us */
-     trailer_tvb = NULL;	/* we don't know how big the trailer is */
-  }
-
-  switch (ethhdr_type) {
-    case ETHERNET_802_3:
-      call_dissector(ipx_handle, next_tvb, pinfo, tree);
-      break;
-    case ETHERNET_802_2:
-      call_dissector(llc_handle, next_tvb, pinfo, tree);
-      break;
-    case ETHERNET_II:
-      length_before = tvb_reported_length(tvb);
-      length = ethertype(etype, tvb, ETH_HEADER_SIZE, pinfo, tree, fh_tree,
-          hf_eth_type) + ETH_HEADER_SIZE;
-      if (length < length_before) {
-	/*
-	 * Create a tvbuff for the padding.
-	 */
-	TRY {
-	  trailer_tvb = tvb_new_subset(tvb, length, -1, -1);
-	}
-	CATCH2(BoundsError, ReportedBoundsError) {
-	  /* The packet doesn't have "length" bytes worth of captured
-	     data left in it.  No trailer to display. */
-	  trailer_tvb = NULL;
-	}
-	ENDTRY;
-      }
-      break;
-  }
 
-  /* If there's some bytes left over, mark them. */
-  if (trailer_tvb && tree) {
-	  guint           trailer_length;
+    next_tvb = NULL;	/* "ethertype()" will create the next tvb for us */
+    trailer_tvb = NULL;	/* we don't know how big the trailer is */
 
-	  trailer_length = tvb_length(trailer_tvb);
-	  if (trailer_length != 0) {
-		  proto_tree_add_item(fh_tree, hf_eth_trailer, trailer_tvb, 0,
-			  trailer_length, FALSE);
-	  }
+    ethertype(etype, tvb, ETH_HEADER_SIZE, pinfo, tree, fh_tree, hf_eth_type,
+          hf_eth_trailer);
   }
-
 }
 
 void
diff --git a/packet-ethertype.c b/packet-ethertype.c
index 454c58fbfa..ffe3682fb3 100644
--- a/packet-ethertype.c
+++ b/packet-ethertype.c
@@ -1,7 +1,7 @@
 /* ethertype.c
  * Routines for calling the right protocol for the ethertype.
  *
- * $Id: packet-ethertype.c,v 1.9 2000/11/18 10:38:24 guy Exp $
+ * $Id: packet-ethertype.c,v 1.10 2001/01/18 07:44:39 guy Exp $
  *
  * Gilbert Ramirez <gram@xiexie.org>
  *
@@ -95,21 +95,28 @@ capture_ethertype(guint16 etype, int offset,
   }
 }
 
-guint
-ethertype(guint16 etype, tvbuff_t *tvb, int offset_after_etype, packet_info *pinfo,
-		proto_tree *tree, proto_tree *fh_tree, int item_id)
+void
+ethertype(guint16 etype, tvbuff_t *tvb, int offset_after_etype,
+		packet_info *pinfo, proto_tree *tree, proto_tree *fh_tree,
+		int etype_id, int trailer_id)
 {
 	char		*description;
 	tvbuff_t	*next_tvb;
+	guint		length_before, length;
+	tvbuff_t	*volatile trailer_tvb;
 	
 	/* Add to proto_tree */
 	if (tree) {
-		proto_tree_add_uint(fh_tree, item_id, tvb, offset_after_etype - 2, 2, etype);
+		proto_tree_add_uint(fh_tree, etype_id, tvb,
+		    offset_after_etype - 2, 2, etype);
 	}
 
 	/* Tvbuff for the payload after the Ethernet type. */
 	next_tvb = tvb_new_subset(tvb, offset_after_etype, -1, -1);
 
+	/* Remember how much data there is in it. */
+	length_before = tvb_reported_length(next_tvb);
+
 	/* Look for sub-dissector */
 	if (!dissector_try_port(ethertype_dissector_table, etype,
 	    next_tvb, pinfo, tree)) {
@@ -139,10 +146,39 @@ ethertype(guint16 etype, tvbuff_t *tvb, int offset_after_etype, packet_info *pin
 		}
 	}
 
-	/* Return the length of that tvbuff; the subdissector may have
-	   reduced the length to a value specified by a length field
-	   in its header, meaning what remains is padding. */
-	return tvb_reported_length(next_tvb);
+	/* OK, how much is there in that tvbuff now? */
+	length = tvb_reported_length(next_tvb);
+
+	/* If there's less than there was before, what's left is
+	   a trailer. */
+	if (length < length_before) {
+		/*
+		 * Create a tvbuff for the padding.
+		 */
+		TRY {
+			trailer_tvb = tvb_new_subset(tvb,
+			    offset_after_etype + length, -1, -1);
+		}
+		CATCH2(BoundsError, ReportedBoundsError) {
+			/* The packet doesn't have "length" bytes worth of
+			   captured data left in it.  No trailer to display. */
+			trailer_tvb = NULL;
+		}
+		ENDTRY;
+	} else
+		trailer_tvb = NULL;	/* no trailer */
+
+	/* If there's some bytes left over, and we were given an item ID
+	   for a trailer, mark those bytes as a trailer. */
+	if (trailer_tvb && tree && trailer_id != -1) {
+		guint	trailer_length;
+
+		trailer_length = tvb_length(trailer_tvb);
+		if (trailer_length != 0) {
+			proto_tree_add_item(fh_tree, trailer_id, trailer_tvb, 0,
+			    trailer_length, FALSE);
+		}
+	}
 }
 
 
diff --git a/packet-llc.c b/packet-llc.c
index f6b6a5cbf0..c517b19f74 100644
--- a/packet-llc.c
+++ b/packet-llc.c
@@ -2,7 +2,7 @@
  * Routines for IEEE 802.2 LLC layer
  * Gilbert Ramirez <gram@xiexie.org>
  *
- * $Id: packet-llc.c,v 1.80 2001/01/11 07:24:17 guy Exp $
+ * $Id: packet-llc.c,v 1.81 2001/01/18 07:44:39 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -398,7 +398,7 @@ dissect_snap(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree,
 		   packet type for AARP packets. */
 		if (XDLC_IS_INFORMATION(control)) {
 			ethertype(etype, tvb, offset+5,
-			    pinfo, tree, snap_tree, hf_type);
+			    pinfo, tree, snap_tree, hf_type, -1);
 		} else {
 			next_tvb = tvb_new_subset(tvb, offset+5, -1, -1);
 			dissect_data(next_tvb, 0, pinfo, tree);
diff --git a/packet-null.c b/packet-null.c
index 7d334aad81..b2559a6524 100644
--- a/packet-null.c
+++ b/packet-null.c
@@ -1,7 +1,7 @@
 /* packet-null.c
  * Routines for null packet disassembly
  *
- * $Id: packet-null.c,v 1.38 2001/01/09 06:31:39 guy Exp $
+ * $Id: packet-null.c,v 1.39 2001/01/18 07:44:39 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -269,7 +269,7 @@ dissect_null(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
         fh_tree = proto_item_add_subtree(ti, ett_null);
       } else
       	fh_tree = NULL;
-      ethertype(null_header, tvb, 4, pinfo, tree, fh_tree, hf_null_etype);
+      ethertype(null_header, tvb, 4, pinfo, tree, fh_tree, hf_null_etype, -1);
     } else {
       /* populate a tree in the second pane with the status of the link
          layer (ie none) */
diff --git a/packet-sll.c b/packet-sll.c
index 2e82af1d62..78bec6f64c 100644
--- a/packet-sll.c
+++ b/packet-sll.c
@@ -1,7 +1,7 @@
 /* packet-sll.c
  * Routines for disassembly of packets from Linux "cooked mode" captures
  *
- * $Id: packet-sll.c,v 1.5 2001/01/09 09:59:28 guy Exp $
+ * $Id: packet-sll.c,v 1.6 2001/01/18 07:44:39 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -138,11 +138,8 @@ dissect_sll(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 	guint16 hatype, halen;
 	guint8 *src;
 	proto_item *ti;
-	volatile guint16 length;
-	tvbuff_t *volatile next_tvb;
-	tvbuff_t *volatile trailer_tvb;
-	proto_tree *volatile fh_tree = NULL;
-	guint length_before;
+	tvbuff_t *next_tvb;
+	proto_tree *fh_tree = NULL;
 
 	CHECK_DISPLAY_AS_DATA(proto_sll, tvb, pinfo, tree);
 
@@ -201,7 +198,6 @@ dissect_sll(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 		    protocol);
 
 		next_tvb = tvb_new_subset(tvb, SLL_HEADER_SIZE, -1, -1);
-		trailer_tvb = NULL;
 		switch (protocol) {
 
 		case LINUX_SLL_P_802_2:
@@ -224,41 +220,8 @@ dissect_sll(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 			break;
 		}
 	} else {
-		length_before = tvb_reported_length(tvb);
-		length = ethertype(protocol, tvb, SLL_HEADER_SIZE, pinfo, tree,
-		    fh_tree, hf_sll_etype) + SLL_HEADER_SIZE;
-		if (length < length_before) {
-			/*
-			 * Create a tvbuff for the padding.
-			 */
-			TRY {
-				trailer_tvb = tvb_new_subset(tvb, length, -1,
-				    -1);
-			}
-			CATCH2(BoundsError, ReportedBoundsError) {
-				/* The packet doesn't have "length" bytes
-				   worth of captured data left in it.  No
-				   trailer to display. */
-				trailer_tvb = NULL;
-			}
-			ENDTRY;
-		} else {
-			/*
-			 * There is no padding.
-			 */
-			trailer_tvb = NULL;
-		}
-	}
-
-	/* If there's some bytes left over, mark them. */
-	if (trailer_tvb && tree) {
-		guint trailer_length;
-
-		trailer_length = tvb_length(trailer_tvb);
-		if (trailer_length != 0) {
-			proto_tree_add_item(fh_tree, hf_sll_trailer,
-			    trailer_tvb, 0, trailer_length, FALSE);
-		}
+		ethertype(protocol, tvb, SLL_HEADER_SIZE, pinfo, tree,
+		    fh_tree, hf_sll_etype, hf_sll_trailer);
 	}
 }
 
diff --git a/packet-vlan.c b/packet-vlan.c
index 173f14bfd4..595ec8f8e9 100644
--- a/packet-vlan.c
+++ b/packet-vlan.c
@@ -1,7 +1,7 @@
 /* packet-vlan.c
  * Routines for VLAN 802.1Q ethernet header disassembly
  *
- * $Id: packet-vlan.c,v 1.29 2001/01/09 09:59:28 guy Exp $
+ * $Id: packet-vlan.c,v 1.30 2001/01/18 07:44:39 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -82,7 +82,6 @@ dissect_vlan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
   tvbuff_t *volatile next_tvb;
   tvbuff_t *volatile trailer_tvb;
   proto_tree *volatile vlan_tree;
-  guint	length_before, length;
 
   CHECK_DISPLAY_AS_DATA(proto_vlan, tvb, pinfo, tree);
 
@@ -164,40 +163,22 @@ dissect_vlan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
     } else {
       call_dissector(ipx_handle, next_tvb, pinfo, tree);
     }
-  } else {
-    length_before = tvb_reported_length(tvb);
-    length = ethertype(encap_proto, tvb, 4, pinfo, tree, vlan_tree,
-		       hf_vlan_etype) + 4;
-    if (length < length_before) {
-      /*
-       * Create a tvbuff for the padding.
-       */
-      TRY {
-	trailer_tvb = tvb_new_subset(tvb, length, -1, -1);
-      }
-      CATCH2(BoundsError, ReportedBoundsError) {
-	/* The packet doesn't have "length" bytes worth of captured
-	   data left in it.  No trailer to display. */
-	trailer_tvb = NULL;
-      }
-      ENDTRY;
-    } else {
-      /* No padding. */
-      trailer_tvb = NULL;
-    }
-  }
 
-  /* If there's some bytes left over, mark them. */
-  if (trailer_tvb && tree) {
-    int trailer_length;
-    const guint8    *ptr;
+    /* If there's some bytes left over, mark them. */
+    if (trailer_tvb && tree) {
+      int trailer_length;
+      const guint8    *ptr;
 
-    trailer_length = tvb_length(trailer_tvb);
-    if (trailer_length > 0) {
-      ptr = tvb_get_ptr(trailer_tvb, 0, trailer_length);
-      proto_tree_add_bytes(vlan_tree, hf_vlan_trailer, trailer_tvb, 0,
-			   trailer_length, ptr);
+      trailer_length = tvb_length(trailer_tvb);
+      if (trailer_length > 0) {
+        ptr = tvb_get_ptr(trailer_tvb, 0, trailer_length);
+        proto_tree_add_bytes(vlan_tree, hf_vlan_trailer, trailer_tvb, 0,
+			     trailer_length, ptr);
+      }
     }
+  } else {
+    ethertype(encap_proto, tvb, 4, pinfo, tree, vlan_tree,
+		       hf_vlan_etype, hf_vlan_trailer);
   }
 }