ofp-util: Ignore invalid bitmaps in ofputil_decode_hello_bitmap().

[openvswitch] / lib / ofp-util.c

diff --git a/lib/ofp-util.c b/lib/ofp-util.c
index ae54477ee567f50317db0ea6ac1bb3c0d1ac6664..14ac7c13d1ad5076afaf911c611459b6895f2935 100644 (file)
--- a/lib/ofp-util.c
+++ b/lib/ofp-util.c
@@ -1080,10 +1080,11 @@ ofputil_format_version_bitmap_names(struct ds *msg, uint32_t bitmap)
 
 static bool
 ofputil_decode_hello_bitmap(const struct ofp_hello_elem_header *oheh,
-                            uint32_t *allowed_versions)
+                            uint32_t *allowed_versionsp)
 {
     uint16_t bitmap_len = ntohs(oheh->length) - sizeof *oheh;
     const ovs_be32 *bitmap = (const ovs_be32 *) (oheh + 1);
+    uint32_t allowed_versions;
 
     if (!bitmap_len || bitmap_len % sizeof *bitmap) {
         return false;
@@ -1094,21 +1095,22 @@ ofputil_decode_hello_bitmap(const struct ofp_hello_elem_header *oheh,
      * should have no effect on session negotiation until Open vSwtich supports
      * wire-protocol versions greater than 31.
      */
-    *allowed_versions = ntohl(bitmap[0]);
+    allowed_versions = ntohl(bitmap[0]);
 
-    if (*allowed_versions & 1) {
+    if (allowed_versions & 1) {
         /* There's no OpenFlow version 0. */
         VLOG_WARN_RL(&bad_ofmsg_rl, "peer claims to support invalid OpenFlow "
                      "version 0x00");
-        *allowed_versions &= ~1u;
+        allowed_versions &= ~1u;
     }
 
-    if (!*allowed_versions) {
+    if (!allowed_versions) {
         VLOG_WARN_RL(&bad_ofmsg_rl, "peer does not support any OpenFlow "
                      "version (between 0x01 and 0x1f)");
         return false;
     }
 
+    *allowed_versionsp = allowed_versions;
     return true;
 }
 
@@ -1181,7 +1183,7 @@ ofputil_encode_hello(uint32_t allowed_versions)
         struct ofp_hello_elem_header *oheh;
         uint16_t map_len;
 
-        map_len = sizeof(uint32_t) / CHAR_BIT;
+        map_len = sizeof allowed_versions;
         oheh = ofpbuf_put_zeros(msg, ROUND_UP(map_len + sizeof *oheh, 8));
         oheh->type = htons(OFPHET_VERSIONBITMAP);
         oheh->length = htons(map_len + sizeof *oheh);