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Diffstat (limited to 'net/ipv6/ip6_offload.c')
-rw-r--r--net/ipv6/ip6_offload.c317
1 files changed, 317 insertions, 0 deletions
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
new file mode 100644
index 000000000..e893cd186
--- /dev/null
+++ b/net/ipv6/ip6_offload.c
@@ -0,0 +1,317 @@
+/*
+ * 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 <linux/printk.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;
+
+ opth = (void *)skb->data;
+ proto = opth->nexthdr;
+ __skb_pull(skb, len);
+ }
+
+ return proto;
+}
+
+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;
+ bool encap, udpfrag;
+ int nhoff;
+
+ if (unlikely(skb_shinfo(skb)->gso_type &
+ ~(SKB_GSO_TCPV4 |
+ SKB_GSO_UDP |
+ SKB_GSO_DODGY |
+ SKB_GSO_TCP_ECN |
+ SKB_GSO_GRE |
+ SKB_GSO_GRE_CSUM |
+ SKB_GSO_IPIP |
+ SKB_GSO_SIT |
+ SKB_GSO_UDP_TUNNEL |
+ SKB_GSO_UDP_TUNNEL_CSUM |
+ SKB_GSO_TUNNEL_REMCSUM |
+ SKB_GSO_TCPV6 |
+ 0)))
+ goto out;
+
+ skb_reset_network_header(skb);
+ nhoff = skb_network_header(skb) - skb_mac_header(skb);
+ if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
+ goto out;
+
+ encap = SKB_GSO_CB(skb)->encap_level > 0;
+ if (encap)
+ features &= skb->dev->hw_enc_features;
+ SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h);
+
+ ipv6h = ipv6_hdr(skb);
+ __skb_pull(skb, sizeof(*ipv6h));
+ segs = ERR_PTR(-EPROTONOSUPPORT);
+
+ proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
+
+ if (skb->encapsulation &&
+ skb_shinfo(skb)->gso_type & (SKB_GSO_SIT|SKB_GSO_IPIP))
+ udpfrag = proto == IPPROTO_UDP && encap;
+ else
+ udpfrag = proto == IPPROTO_UDP && !skb->encapsulation;
+
+ ops = rcu_dereference(inet6_offloads[proto]);
+ if (likely(ops && ops->callbacks.gso_segment)) {
+ skb_reset_transport_header(skb);
+ segs = ops->callbacks.gso_segment(skb, features);
+ }
+
+ if (IS_ERR(segs))
+ goto out;
+
+ for (skb = segs; skb; skb = skb->next) {
+ ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff);
+ ipv6h->payload_len = htons(skb->len - nhoff - sizeof(*ipv6h));
+ skb->network_header = (u8 *)ipv6h - skb->head;
+
+ if (udpfrag) {
+ unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
+ fptr = (struct frag_hdr *)((u8 *)ipv6h + unfrag_ip6hlen);
+ fptr->frag_off = htons(offset);
+ if (skb->next)
+ fptr->frag_off |= htons(IP6_MF);
+ offset += (ntohs(ipv6h->payload_len) -
+ sizeof(struct frag_hdr));
+ }
+ if (encap)
+ skb_reset_inner_headers(skb);
+ }
+
+out:
+ return segs;
+}
+
+/* Return the total length of all the extension hdrs, following the same
+ * logic in ipv6_gso_pull_exthdrs() when parsing ext-hdrs.
+ */
+static int ipv6_exthdrs_len(struct ipv6hdr *iph,
+ const struct net_offload **opps)
+{
+ struct ipv6_opt_hdr *opth = (void *)iph;
+ int len = 0, proto, optlen = sizeof(*iph);
+
+ proto = iph->nexthdr;
+ for (;;) {
+ if (proto != NEXTHDR_HOP) {
+ *opps = rcu_dereference(inet6_offloads[proto]);
+ if (unlikely(!(*opps)))
+ break;
+ if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))
+ break;
+ }
+ opth = (void *)opth + optlen;
+ optlen = ipv6_optlen(opth);
+ len += optlen;
+ proto = opth->nexthdr;
+ }
+ return len;
+}
+
+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;
+ u16 flush = 1;
+ int proto;
+
+ 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_set_network_header(skb, off);
+ 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->callbacks.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->callbacks.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 = (struct ipv6hdr *)(p->data + off);
+ first_word = *(__be32 *)iph ^ *(__be32 *)iph2;
+
+ /* All fields must match except length and Traffic Class.
+ * XXX skbs on the gro_list have all been parsed and pulled
+ * already so we don't need to compare nlen
+ * (nlen != (sizeof(*iph2) + ipv6_exthdrs_len(iph2, &ops)))
+ * memcmp() alone below is suffcient, right?
+ */
+ if ((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;
+
+ /* Clear flush_id, there's really no concept of ID in IPv6. */
+ NAPI_GRO_CB(p)->flush_id = 0;
+ }
+
+ NAPI_GRO_CB(skb)->flush |= flush;
+
+ skb_gro_postpull_rcsum(skb, iph, nlen);
+
+ pp = ops->callbacks.gro_receive(head, skb);
+
+out_unlock:
+ rcu_read_unlock();
+
+out:
+ NAPI_GRO_CB(skb)->flush |= flush;
+
+ return pp;
+}
+
+static int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
+{
+ const struct net_offload *ops;
+ struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + nhoff);
+ int err = -ENOSYS;
+
+ iph->payload_len = htons(skb->len - nhoff - sizeof(*iph));
+
+ rcu_read_lock();
+
+ nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops);
+ if (WARN_ON(!ops || !ops->callbacks.gro_complete))
+ goto out_unlock;
+
+ err = ops->callbacks.gro_complete(skb, nhoff);
+
+out_unlock:
+ rcu_read_unlock();
+
+ return err;
+}
+
+static struct packet_offload ipv6_packet_offload __read_mostly = {
+ .type = cpu_to_be16(ETH_P_IPV6),
+ .callbacks = {
+ .gso_segment = ipv6_gso_segment,
+ .gro_receive = ipv6_gro_receive,
+ .gro_complete = ipv6_gro_complete,
+ },
+};
+
+static const struct net_offload sit_offload = {
+ .callbacks = {
+ .gso_segment = ipv6_gso_segment,
+ .gro_receive = ipv6_gro_receive,
+ .gro_complete = ipv6_gro_complete,
+ },
+};
+
+static int __init ipv6_offload_init(void)
+{
+
+ if (tcpv6_offload_init() < 0)
+ pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
+ if (udp_offload_init() < 0)
+ pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
+ if (ipv6_exthdrs_offload_init() < 0)
+ pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__);
+
+ dev_add_offload(&ipv6_packet_offload);
+
+ inet_add_offload(&sit_offload, IPPROTO_IPV6);
+
+ return 0;
+}
+
+fs_initcall(ipv6_offload_init);