Merging upstream version 4.4.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 130 insertions, 31 deletions

diff --git a/epan/dissectors/packet-pw-eth.c b/epan/dissectors/packet-pw-eth.c
index aec7b662..524dbe69 100644
--- a/epan/dissectors/packet-pw-eth.c
+++ b/epan/dissectors/packet-pw-eth.c
@@ -16,21 +16,23 @@
 
 #include <epan/packet.h>
 #include <epan/addr_resolv.h>
+#include <epan/etypes.h>
+#include <epan/dissectors/packet-llc.h>
 
 #include "packet-mpls.h"
 
 void proto_register_pw_eth(void);
 void proto_reg_handoff_pw_eth(void);
 
-static gint proto_pw_eth_cw = -1;
-static gint proto_pw_eth_nocw = -1;
-static gint proto_pw_eth_heuristic = -1;
+static int proto_pw_eth_cw;
+static int proto_pw_eth_nocw;
+static int proto_pw_eth_heuristic;
 
-static gint ett_pw_eth = -1;
+static int ett_pw_eth;
 
-static int hf_pw_eth = -1;
-static int hf_pw_eth_cw = -1;
-static int hf_pw_eth_cw_sequence_number = -1;
+static int hf_pw_eth;
+static int hf_pw_eth_cw;
+static int hf_pw_eth_cw_sequence_number;
 
 static dissector_handle_t eth_withoutfcs_handle;
 static dissector_handle_t pw_eth_handle_cw;
@@ -41,7 +43,7 @@ static int
 dissect_pw_eth_cw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
 {
     tvbuff_t *next_tvb;
-    guint16   sequence_number;
+    uint16_t  sequence_number;
 
     if (tvb_reported_length_remaining(tvb, 0) < 4) {
         return 0;
@@ -57,7 +59,7 @@ dissect_pw_eth_cw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* dat
         proto_item *ti;
 
         ti = proto_tree_add_boolean(tree, hf_pw_eth_cw,
-                                    tvb, 0, 0, TRUE);
+                                    tvb, 0, 0, true);
         proto_item_set_hidden(ti);
         ti = proto_tree_add_item(tree, proto_pw_eth_cw,
                                  tvb, 0, 4, ENC_NA);
@@ -85,7 +87,7 @@ dissect_pw_eth_nocw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* d
 
     if (tree) {
         proto_item *ti;
-        ti = proto_tree_add_boolean(tree, hf_pw_eth, tvb, 0, 0, TRUE);
+        ti = proto_tree_add_boolean(tree, hf_pw_eth, tvb, 0, 0, true);
         proto_item_set_hidden(ti);
     }
 
@@ -96,43 +98,134 @@ dissect_pw_eth_nocw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* d
 }
 
 /*
- * FF: this function returns TRUE if the first 12 bytes in tvb looks like
- *     two valid ethernet addresses.  FALSE otherwise.
+ * FF: this function returns true if the first 12 bytes in tvb looks like
+ *     two valid ethernet addresses.  false otherwise.
  */
-static gboolean
-looks_like_plain_eth(tvbuff_t *tvb _U_)
+static int
+looks_like_plain_eth(tvbuff_t *tvb, int offset)
 {
-    const gchar *manuf_name_da;
-    const gchar *manuf_name_sa;
+    const char *manuf_name_da;
+    const char *manuf_name_sa;
+    uint16_t etype;
+    int ret = 2;
+
+    /* Don't throw an exception. If the packet is truncated, you lose. */
+    if (tvb_captured_length_remaining(tvb, offset) < 14) {
+        return 0;
+    }
+
+    /* Copy the source and destination addresses, as tvb_get_manuf_name_if_known
+     * only uses the first three bytes (it's for an OUI in, e.g., IEEE 802.11),
+     * and returns NULL for MA-M and MA-S.
+     */
+    uint8_t da[6], sa[6];
+    tvb_memcpy(tvb, da, offset, 6);
+    /* da[0] & 0x2 is the U/L bit; if it's set, none of this helps. (#13039) */
+    if (da[0] & 0x2) {
+        // U/L bit; locally assigned addresses are a less solid heuristic
+        ret = 1;
+    } else {
+        manuf_name_da = get_manuf_name_if_known(da, 6);
+        if (!manuf_name_da) {
+            /* Try looking for an exact match in the ethers file. */
+            manuf_name_da = get_ether_name_if_known(da);
+            if (!manuf_name_da) {
+                return 0;
+            }
+        }
+    }
+    offset += 6;
 
-    if (tvb_reported_length_remaining(tvb, 0) < 14) {
-        return FALSE;
+    tvb_memcpy(tvb, sa, offset, 6);
+    if (sa[0] & 0x1) {
+        // Group bit should not be set on source
+        return 0;
     }
+    if (sa[0] & 0x2) {
+        // U/L bit; locally assigned addresses are a less solid heuristic
+        ret = 1;
+    } else {
+        manuf_name_sa = get_manuf_name_if_known(sa, 6);
+        if (!manuf_name_sa) {
+            manuf_name_sa = get_ether_name_if_known(sa);
+            if (!manuf_name_sa) {
+                return 0;
+            }
+        }
+    }
+    offset += 6;
+    etype = tvb_get_ntohs(tvb, offset);
+
+    if (etype > IEEE_802_3_MAX_LEN) {
+        if (etype < ETHERNET_II_MIN_LEN) {
+            return 0;
+        }
 
-    manuf_name_da = tvb_get_manuf_name_if_known(tvb, 0);
-    manuf_name_sa = tvb_get_manuf_name_if_known(tvb, 6);
+        if (!try_val_to_str(etype, etype_vals)) {
+            return 0;
+        }
+    } else {
+        offset += 2;
+        /* XXX - There are unusual cases like Cisco ISL, Novell raw 802.3
+         * for IPX/SPX, etc. See packet-eth capture_eth()
+         */
+        if (tvb_reported_length_remaining(tvb, offset) < etype) {
+            return 0;
+        }
 
-    if (manuf_name_da && manuf_name_sa) {
-        return TRUE;
+        if (tvb_captured_length_remaining(tvb, offset) < 3) {
+            return 0;
+        }
+        uint8_t sap;
+        sap = tvb_get_uint8(tvb, offset);
+        if (!try_val_to_str(sap, sap_vals)) {
+            return 0;
+        }
+        offset += 1;
+        sap = tvb_get_uint8(tvb, offset);
+        if (!try_val_to_str(sap, sap_vals)) {
+            return 0;
+        }
+        /* We could go deeper, and see if this looks like SNAP if the dsap
+         * and ssap are both 0xAA (the common case).
+         */
     }
 
-    return FALSE;
+    return ret;
 }
 
 static int
 dissect_pw_eth_heuristic(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
 {
-    guint8 first_nibble = (tvb_get_guint8(tvb, 0) >> 4) & 0x0F;
-
-    if (looks_like_plain_eth(tvb))
-        call_dissector(pw_eth_handle_nocw, tvb, pinfo, tree);
-    else if (first_nibble == 0)
-        call_dissector(pw_eth_handle_cw, tvb, pinfo, tree);
-    else
+    /*
+     * RFC 8469 states that that both ingress and egress SHOULD support the PW
+     * CW, and if they do, the CW MUST be used. So it looks equally likely to
+     * have the CW as not, assume CW.
+     */
+    uint8_t first_nibble = (tvb_get_uint8(tvb, 0) >> 4) & 0x0F;
+
+    if (first_nibble == 0) {
+        if (looks_like_plain_eth(tvb, 4) >= looks_like_plain_eth(tvb, 0)) {
+            call_dissector(pw_eth_handle_cw, tvb, pinfo, tree);
+        } else {
+            call_dissector(pw_eth_handle_nocw, tvb, pinfo, tree);
+        }
+    } else {
         call_dissector(pw_eth_handle_nocw, tvb, pinfo, tree);
+    }
     return tvb_captured_length(tvb);
 }
 
+static bool
+dissect_pw_eth_nocw_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
+{
+    if (!looks_like_plain_eth(tvb, 0)) {
+        return false;
+    }
+    dissect_pw_eth_nocw(tvb, pinfo, tree, data);
+    return true;
+}
+
 void
 proto_register_pw_eth(void)
 {
@@ -163,7 +256,7 @@ proto_register_pw_eth(void)
         }
     };
 
-    static gint *ett[] = {
+    static int *ett[] = {
         &ett_pw_eth
     };
 
@@ -190,12 +283,18 @@ proto_register_pw_eth(void)
 void
 proto_reg_handoff_pw_eth(void)
 {
+    heur_dissector_add("mpls", dissect_pw_eth_nocw_heur,
+        "Ethernet PW (no CW)", "pwethnocw", proto_pw_eth_nocw,
+        HEURISTIC_ENABLE);
     eth_withoutfcs_handle = find_dissector_add_dependency("eth_withoutfcs", proto_pw_eth_cw);
 
     dissector_add_for_decode_as("mpls.label", pw_eth_handle_cw);
     dissector_add_for_decode_as("mpls.label", pw_eth_handle_nocw);
 
     dissector_add_for_decode_as("mpls.label", pw_eth_handle_heuristic);
+
+    dissector_add_for_decode_as("mpls.pfn", pw_eth_handle_cw);
+    dissector_add_for_decode_as("mpls.pfn", pw_eth_handle_nocw);
 }
 
 /*