| /* |
| * 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 = call_gro_receive(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, |
| }, |
| }; |
| |
| 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); |