| /* |
| * 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; |
| |
| 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, |
| }; |
| |
| 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); |
| return 0; |
| } |
| |
| fs_initcall(ipv6_offload_init); |