/* * 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 #include #include #include #include #include #include #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->callbacks.gso_send_check)) { skb_reset_transport_header(skb); err = ops->callbacks.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_GRE | 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->callbacks.gso_segment)) { skb_reset_transport_header(skb); segs = ops->callbacks.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->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; /* */ 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->callbacks.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->callbacks.gro_complete)) goto out_unlock; err = ops->callbacks.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), .callbacks = { .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);