X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fpackets.c;h=8fb7f6b0320fac2a7fabcb02f6bd820420a91e8a;hb=6e492d81450217a5c90cbb4ad31d81b1e611989b;hp=eaf3e43f4c1cb86d5bbe1f10cfbc7135b9674ecd;hpb=c97664b30f65d3a087076cb33242ffe2cc52a814;p=openvswitch

diff --git a/lib/packets.c b/lib/packets.c
index eaf3e43f..8fb7f6b0 100644
--- a/lib/packets.c
+++ b/lib/packets.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2009, 2010, 2011, 2012 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,7 @@
 #include <stdlib.h>
 #include "byte-order.h"
 #include "csum.h"
+#include "flow.h"
 #include "dynamic-string.h"
 #include "ofpbuf.h"
 
@@ -478,3 +479,20 @@ packet_set_udp_port(struct ofpbuf *packet, ovs_be16 src, ovs_be16 dst)
         uh->udp_dst = dst;
     }
 }
+
+/* If 'packet' is a TCP packet, returns the TCP flags.  Otherwise, returns 0.
+ *
+ * 'flow' must be the flow corresponding to 'packet' and 'packet''s header
+ * pointers must be properly initialized (e.g. with flow_extract()). */
+uint8_t
+packet_get_tcp_flags(const struct ofpbuf *packet, const struct flow *flow)
+{
+    if ((flow->dl_type == htons(ETH_TYPE_IP) ||
+         flow->dl_type == htons(ETH_TYPE_IPV6)) &&
+        flow->nw_proto == IPPROTO_TCP && packet->l7) {
+        const struct tcp_header *tcp = packet->l4;
+        return TCP_FLAGS(tcp->tcp_ctl);
+    } else {
+        return 0;
+    }
+}