ipv6: Separate ipv6 offload support
Separate IPv6 offload functionality into its own file
in preparation for the move out of the module
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
new file mode 100644
index 0000000..01cf983
--- /dev/null
+++ b/net/ipv6/ip6_offload.c
@@ -0,0 +1,273 @@
+/*
+ * IPV6 GSO/GRO offload support
+ * Linux INET6 implementation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/socket.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+
+#include <net/protocol.h>
+#include <net/ipv6.h>
+
+#include "ip6_offload.h"
+
+static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
+{
+ const struct net_offload *ops = NULL;
+
+ for (;;) {
+ struct ipv6_opt_hdr *opth;
+ int len;
+
+ if (proto != NEXTHDR_HOP) {
+ ops = rcu_dereference(inet6_offloads[proto]);
+
+ if (unlikely(!ops))
+ break;
+
+ if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
+ break;
+ }
+
+ if (unlikely(!pskb_may_pull(skb, 8)))
+ break;
+
+ opth = (void *)skb->data;
+ len = ipv6_optlen(opth);
+
+ if (unlikely(!pskb_may_pull(skb, len)))
+ break;
+
+ proto = opth->nexthdr;
+ __skb_pull(skb, len);
+ }
+
+ return proto;
+}
+
+static int ipv6_gso_send_check(struct sk_buff *skb)
+{
+ const struct ipv6hdr *ipv6h;
+ const struct net_offload *ops;
+ int err = -EINVAL;
+
+ if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
+ goto out;
+
+ ipv6h = ipv6_hdr(skb);
+ __skb_pull(skb, sizeof(*ipv6h));
+ err = -EPROTONOSUPPORT;
+
+ rcu_read_lock();
+ ops = rcu_dereference(inet6_offloads[
+ ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr)]);
+
+ if (likely(ops && ops->gso_send_check)) {
+ skb_reset_transport_header(skb);
+ err = ops->gso_send_check(skb);
+ }
+ rcu_read_unlock();
+
+out:
+ return err;
+}
+
+static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
+ netdev_features_t features)
+{
+ struct sk_buff *segs = ERR_PTR(-EINVAL);
+ struct ipv6hdr *ipv6h;
+ const struct net_offload *ops;
+ int proto;
+ struct frag_hdr *fptr;
+ unsigned int unfrag_ip6hlen;
+ u8 *prevhdr;
+ int offset = 0;
+
+ if (!(features & NETIF_F_V6_CSUM))
+ features &= ~NETIF_F_SG;
+
+ if (unlikely(skb_shinfo(skb)->gso_type &
+ ~(SKB_GSO_UDP |
+ SKB_GSO_DODGY |
+ SKB_GSO_TCP_ECN |
+ SKB_GSO_TCPV6 |
+ 0)))
+ goto out;
+
+ if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
+ goto out;
+
+ ipv6h = ipv6_hdr(skb);
+ __skb_pull(skb, sizeof(*ipv6h));
+ segs = ERR_PTR(-EPROTONOSUPPORT);
+
+ proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
+ rcu_read_lock();
+ ops = rcu_dereference(inet6_offloads[proto]);
+ if (likely(ops && ops->gso_segment)) {
+ skb_reset_transport_header(skb);
+ segs = ops->gso_segment(skb, features);
+ }
+ rcu_read_unlock();
+
+ if (IS_ERR(segs))
+ goto out;
+
+ for (skb = segs; skb; skb = skb->next) {
+ ipv6h = ipv6_hdr(skb);
+ ipv6h->payload_len = htons(skb->len - skb->mac_len -
+ sizeof(*ipv6h));
+ if (proto == IPPROTO_UDP) {
+ unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
+ fptr = (struct frag_hdr *)(skb_network_header(skb) +
+ unfrag_ip6hlen);
+ fptr->frag_off = htons(offset);
+ if (skb->next != NULL)
+ fptr->frag_off |= htons(IP6_MF);
+ offset += (ntohs(ipv6h->payload_len) -
+ sizeof(struct frag_hdr));
+ }
+ }
+
+out:
+ return segs;
+}
+
+static struct sk_buff **ipv6_gro_receive(struct sk_buff **head,
+ struct sk_buff *skb)
+{
+ const struct net_offload *ops;
+ struct sk_buff **pp = NULL;
+ struct sk_buff *p;
+ struct ipv6hdr *iph;
+ unsigned int nlen;
+ unsigned int hlen;
+ unsigned int off;
+ int flush = 1;
+ int proto;
+ __wsum csum;
+
+ off = skb_gro_offset(skb);
+ hlen = off + sizeof(*iph);
+ iph = skb_gro_header_fast(skb, off);
+ if (skb_gro_header_hard(skb, hlen)) {
+ iph = skb_gro_header_slow(skb, hlen, off);
+ if (unlikely(!iph))
+ goto out;
+ }
+
+ skb_gro_pull(skb, sizeof(*iph));
+ skb_set_transport_header(skb, skb_gro_offset(skb));
+
+ flush += ntohs(iph->payload_len) != skb_gro_len(skb);
+
+ rcu_read_lock();
+ proto = iph->nexthdr;
+ ops = rcu_dereference(inet6_offloads[proto]);
+ if (!ops || !ops->gro_receive) {
+ __pskb_pull(skb, skb_gro_offset(skb));
+ proto = ipv6_gso_pull_exthdrs(skb, proto);
+ skb_gro_pull(skb, -skb_transport_offset(skb));
+ skb_reset_transport_header(skb);
+ __skb_push(skb, skb_gro_offset(skb));
+
+ ops = rcu_dereference(inet6_offloads[proto]);
+ if (!ops || !ops->gro_receive)
+ goto out_unlock;
+
+ iph = ipv6_hdr(skb);
+ }
+
+ NAPI_GRO_CB(skb)->proto = proto;
+
+ flush--;
+ nlen = skb_network_header_len(skb);
+
+ for (p = *head; p; p = p->next) {
+ const struct ipv6hdr *iph2;
+ __be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */
+
+ if (!NAPI_GRO_CB(p)->same_flow)
+ continue;
+
+ iph2 = ipv6_hdr(p);
+ first_word = *(__be32 *)iph ^ *(__be32 *)iph2 ;
+
+ /* All fields must match except length and Traffic Class. */
+ if (nlen != skb_network_header_len(p) ||
+ (first_word & htonl(0xF00FFFFF)) ||
+ memcmp(&iph->nexthdr, &iph2->nexthdr,
+ nlen - offsetof(struct ipv6hdr, nexthdr))) {
+ NAPI_GRO_CB(p)->same_flow = 0;
+ continue;
+ }
+ /* flush if Traffic Class fields are different */
+ NAPI_GRO_CB(p)->flush |= !!(first_word & htonl(0x0FF00000));
+ NAPI_GRO_CB(p)->flush |= flush;
+ }
+
+ NAPI_GRO_CB(skb)->flush |= flush;
+
+ csum = skb->csum;
+ skb_postpull_rcsum(skb, iph, skb_network_header_len(skb));
+
+ pp = ops->gro_receive(head, skb);
+
+ skb->csum = csum;
+
+out_unlock:
+ rcu_read_unlock();
+
+out:
+ NAPI_GRO_CB(skb)->flush |= flush;
+
+ return pp;
+}
+
+static int ipv6_gro_complete(struct sk_buff *skb)
+{
+ const struct net_offload *ops;
+ struct ipv6hdr *iph = ipv6_hdr(skb);
+ int err = -ENOSYS;
+
+ iph->payload_len = htons(skb->len - skb_network_offset(skb) -
+ sizeof(*iph));
+
+ rcu_read_lock();
+ ops = rcu_dereference(inet6_offloads[NAPI_GRO_CB(skb)->proto]);
+ if (WARN_ON(!ops || !ops->gro_complete))
+ goto out_unlock;
+
+ err = ops->gro_complete(skb);
+
+out_unlock:
+ rcu_read_unlock();
+
+ return err;
+}
+
+static struct packet_offload ipv6_packet_offload __read_mostly = {
+ .type = cpu_to_be16(ETH_P_IPV6),
+ .gso_send_check = ipv6_gso_send_check,
+ .gso_segment = ipv6_gso_segment,
+ .gro_receive = ipv6_gro_receive,
+ .gro_complete = ipv6_gro_complete,
+};
+
+void __init ipv6_offload_init(void)
+{
+ dev_add_offload(&ipv6_packet_offload);
+}
+
+void ipv6_offload_cleanup(void)
+{
+ dev_remove_offload(&ipv6_packet_offload);
+}