[IPV6]: Added GSO support for TCPv6

This patch adds GSO support for IPv6 and TCPv6.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 72 insertions, 2 deletions

diff --git a/include/net/protocol.h b/include/net/protocol.h
index 40b6b9c9973f..a225d6371cb1 100644
--- a/include/net/protocol.h
+++ b/include/net/protocol.h
@@ -50,11 +50,17 @@ struct inet6_protocol
                                struct inet6_skb_parm *opt,
                                int type, int code, int offset,
                                __u32 info);
+
+        struct sk_buff *(*gso_segment)(struct sk_buff *skb,
+                                       int features);
+
         unsigned int    flags;  /* INET6_PROTO_xxx */
 };
 
 #define INET6_PROTO_NOPOLICY    0x1
 #define INET6_PROTO_FINAL       0x2
+/* This should be set for any extension header which is compatible with GSO. */
+#define INET6_PROTO_GSO_EXTHDR  0x4
 #endif
 
 /* This is used to register socket interfaces for IP protocols.  */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 0bb0ac96d675..b7cf26e0e5c2 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2215,6 +2215,7 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features)
 out:
         return segs;
 }
+EXPORT_SYMBOL(tcp_tso_segment);
 
 extern void __skb_cb_too_small_for_tcp(int, int);
 extern struct tcp_congestion_ops tcp_reno;
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index a18d4256372c..9d0ee7f0eeb5 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -179,7 +179,7 @@ static int ipv6_destopt_rcv(struct sk_buff **skbp)
 
 static struct inet6_protocol destopt_protocol = {
         .handler        =       ipv6_destopt_rcv,
-        .flags          =       INET6_PROTO_NOPOLICY,
+        .flags          =       INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
 };
 
 void __init ipv6_destopt_init(void)
@@ -340,7 +340,7 @@ looped_back:
 
 static struct inet6_protocol rthdr_protocol = {
         .handler        =       ipv6_rthdr_rcv,
-        .flags          =       INET6_PROTO_NOPOLICY,
+        .flags          =       INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
 };
 
 void __init ipv6_rthdr_init(void)
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 4c20eeb3d568..25f8bf8ac49b 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -58,9 +58,71 @@
 
 DEFINE_SNMP_STAT(struct ipstats_mib, ipv6_statistics) __read_mostly;
 
+static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb, int features)
+{
+        struct sk_buff *segs = ERR_PTR(-EINVAL);
+        struct ipv6hdr *ipv6h;
+        struct inet6_protocol *ops;
+        int proto;
+
+        if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
+                goto out;
+
+        ipv6h = skb->nh.ipv6h;
+        proto = ipv6h->nexthdr;
+        __skb_pull(skb, sizeof(*ipv6h));
+
+        rcu_read_lock();
+        for (;;) {
+                struct ipv6_opt_hdr *opth;
+                int len;
+
+                if (proto != NEXTHDR_HOP) {
+                        ops = rcu_dereference(inet6_protos[proto]);
+
+                        if (unlikely(!ops))
+                                goto unlock;
+
+                        if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
+                                break;
+                }
+
+                if (unlikely(!pskb_may_pull(skb, 8)))
+                        goto unlock;
+
+                opth = (void *)skb->data;
+                len = opth->hdrlen * 8 + 8;
+
+                if (unlikely(!pskb_may_pull(skb, len)))
+                        goto unlock;
+
+                proto = opth->nexthdr;
+                __skb_pull(skb, len);
+        }
+
+        skb->h.raw = skb->data;
+        if (likely(ops->gso_segment))
+                segs = ops->gso_segment(skb, features);
+
+unlock:
+        rcu_read_unlock();
+
+        if (unlikely(IS_ERR(segs)))
+                goto out;
+
+        for (skb = segs; skb; skb = skb->next) {
+                ipv6h = skb->nh.ipv6h;
+                ipv6h->payload_len = htons(skb->len - skb->mac_len);
+        }
+
+out:
+        return segs;
+}
+
 static struct packet_type ipv6_packet_type = {
         .type = __constant_htons(ETH_P_IPV6), 
         .func = ipv6_rcv,
+        .gso_segment = ipv6_gso_segment,
 };
 
 struct ip6_ra_chain *ip6_ra_chain;
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index b36d5b2e7c30..bf7f8c26c488 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1606,6 +1606,7 @@ struct proto tcpv6_prot = {
 static struct inet6_protocol tcpv6_protocol = {
         .handler        =       tcp_v6_rcv,
         .err_handler    =       tcp_v6_err,
+        .gso_segment    =       tcp_tso_segment,
         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
 };