Merge tag 'mac80211-next-for-davem-2015-01-15' of git://git.kernel.org/pub/scm/linux...

[cascardo/linux.git] / net / ipv6 / ip6_checksum.c

diff --git a/net/ipv6/ip6_checksum.c b/net/ipv6/ip6_checksum.c
index ee7a97f..9a4d732 100644 (file)
--- a/net/ipv6/ip6_checksum.c
+++ b/net/ipv6/ip6_checksum.c
@@ -75,25 +75,50 @@ int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto)
                        return err;
        }
 
-       if (uh->check == 0) {
-               /* RFC 2460 section 8.1 says that we SHOULD log
-                  this error. Well, it is reasonable.
-                */
-               LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
-                              &ipv6_hdr(skb)->saddr, ntohs(uh->source),
-                              &ipv6_hdr(skb)->daddr, ntohs(uh->dest));
-               return 1;
-       }
-       if (skb->ip_summed == CHECKSUM_COMPLETE &&
-           !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
-                            skb->len, proto, skb->csum))
-               skb->ip_summed = CHECKSUM_UNNECESSARY;
+       /* To support RFC 6936 (allow zero checksum in UDP/IPV6 for tunnels)
+        * we accept a checksum of zero here. When we find the socket
+        * for the UDP packet we'll check if that socket allows zero checksum
+        * for IPv6 (set by socket option).
+        */
+       return skb_checksum_init_zero_check(skb, proto, uh->check,
+                                          ip6_compute_pseudo);
+}
+EXPORT_SYMBOL(udp6_csum_init);
+
+/* Function to set UDP checksum for an IPv6 UDP packet. This is intended
+ * for the simple case like when setting the checksum for a UDP tunnel.
+ */
+void udp6_set_csum(bool nocheck, struct sk_buff *skb,
+                  const struct in6_addr *saddr,
+                  const struct in6_addr *daddr, int len)
+{
+       struct udphdr *uh = udp_hdr(skb);
+
+       if (nocheck)
+               uh->check = 0;
+       else if (skb_is_gso(skb))
+               uh->check = ~udp_v6_check(len, saddr, daddr, 0);
+       else if (skb_dst(skb) && skb_dst(skb)->dev &&
+                (skb_dst(skb)->dev->features & NETIF_F_IPV6_CSUM)) {
 
-       if (!skb_csum_unnecessary(skb))
-               skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
-                                                        &ipv6_hdr(skb)->daddr,
-                                                        skb->len, proto, 0));
+               BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);
 
-       return 0;
+               skb->ip_summed = CHECKSUM_PARTIAL;
+               skb->csum_start = skb_transport_header(skb) - skb->head;
+               skb->csum_offset = offsetof(struct udphdr, check);
+               uh->check = ~udp_v6_check(len, saddr, daddr, 0);
+       } else {
+               __wsum csum;
+
+               BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);
+
+               uh->check = 0;
+               csum = skb_checksum(skb, 0, len, 0);
+               uh->check = udp_v6_check(len, saddr, daddr, csum);
+               if (uh->check == 0)
+                       uh->check = CSUM_MANGLED_0;
+
+               skb->ip_summed = CHECKSUM_UNNECESSARY;
+       }
 }
-EXPORT_SYMBOL(udp6_csum_init);
+EXPORT_SYMBOL(udp6_set_csum);