rtl8139: check IP Header Length field

The IP Header Length field was only checked in the IP checksum case, but
is used in other cases too.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
[Backport to qemu-xen-tradition]
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

diff --git a/hw/rtl8139.c b/hw/rtl8139.c
index 75ef9b4039486b451f991cfc151c81e5f32f5a51..b71ea62a4ade136b8be559d45b7355d48b249e8b 100644 (file)
--- a/hw/rtl8139.c
+++ b/hw/rtl8139.c
@@ -2139,6 +2139,10 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
             }
 
             hlen = IP_HEADER_LENGTH(ip);
+            if (hlen < sizeof(ip_header) || hlen > eth_payload_len) {
+                goto skip_offload;
+            }
+
             ip_protocol = ip->ip_p;
             ip_data_len = be16_to_cpu(ip->ip_len) - hlen;
 
@@ -2146,16 +2150,10 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
             {
                 DEBUG_PRINT(("RTL8139: +++ C+ mode need IP checksum\n"));
 
-                if (hlen<sizeof(ip_header) || hlen>eth_payload_len) {/* min header length */
-                    /* bad packet header len */
-                    /* or packet too short */
-                }
-                else
-                {
-                    ip->ip_sum = 0;
-                    ip->ip_sum = ip_checksum(ip, hlen);
-                    DEBUG_PRINT(("RTL8139: +++ C+ mode IP header len=%d checksum=%04x\n", hlen, ip->ip_sum));
-                }
+                ip->ip_sum = 0;
+                ip->ip_sum = ip_checksum(ip, hlen);
+                DEBUG_PRINT(("RTL8139: +++ C+ mode IP header len=%d checksum=%04x\n",
+                             hlen, ip->ip_sum));
             }
 
             if ((txdw0 & CP_TX_LGSEN) && ip_protocol == IP_PROTO_TCP)