Add checks to address setting routines.

Fail if:

	1) you have an AT_NONE address with data;

	2) you have a non-AT_NONE address with a zero length and a
	   non-null data pointer, or with a non-zero length and a null
	   data pointer.

When comparing addresses for equality, just make sure the types are the
same, the lengths are the same and, if the lengths are non-zero, the
data is the same; don't treat AT_NONE specially - the "lengths are
non-zero" check will make sure we do the right thing.

Make sure when we create an AT_NONE address it has a zero length and
null data pointer.

Change-Id: I5c452ef0d140c2d9aef3004f1cfd124a95b78fb2
Reviewed-on: https://code.wireshark.org/review/15839
Reviewed-by: Guy Harris <guy@alum.mit.edu>

1 files changed, 5 insertions, 7 deletions

diff --git a/epan/dissectors/packet-sflow.c b/epan/dissectors/packet-sflow.c
index f9a0047200..991f283e8c 100644
--- a/epan/dissectors/packet-sflow.c
+++ b/epan/dissectors/packet-sflow.c
@@ -765,7 +765,7 @@ dissect_sflow_245_address_type(tvbuff_t *tvb, packet_info *pinfo,
         break;
     default:
         /* Invalid address type, or a type we don't understand; we don't
-           know the length. W e treat it as having no contents; that
+           know the length. We treat it as having no contents; that
            doesn't trap us in an endless loop, as we at least include
            the address type and thus at least advance the offset by 4.
            Note that we have a problem, though. */
@@ -776,6 +776,9 @@ dissect_sflow_245_address_type(tvbuff_t *tvb, packet_info *pinfo,
 
     if (addr) {
         switch (len) {
+        default:
+            clear_address(addr);
+            break;
         case 4:
             set_address_tvb(addr, AT_IPv4, len, tvb, offset);
             break;
@@ -2346,16 +2349,12 @@ dissect_sflow_245(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *dat
        /* Unknown version; assume it's not an sFlow packet. */
        return 0;
     }
+
     sflow_addr_type = tvb_get_ntohl(tvb, offset + 4);
     switch (sflow_addr_type) {
         case ADDR_TYPE_UNKNOWN:
-            addr_details.type = AT_NONE;
-            break;
         case ADDR_TYPE_IPV4:
-            addr_details.type = AT_IPv4;
-            break;
         case ADDR_TYPE_IPV6:
-            addr_details.type = AT_IPv6;
             break;
 
         default:
@@ -2365,7 +2364,6 @@ dissect_sflow_245(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *dat
              */
             return 0;
     }
-
     /* Make entries in Protocol column and Info column on summary display */
     col_set_str(pinfo->cinfo, COL_PROTOCOL, "sFlow");