/* * 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 <net/inet_common.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; unsigned int payload_len; u8 *prevhdr; int offset = 0; bool encap, udpfrag; int nhoff; bool gso_partial; 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_IPXIP4 | SKB_GSO_IPXIP6)) 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_OR_NULL(segs)) goto out; gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL); for (skb = segs; skb; skb = skb->next) { ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff); if (gso_partial) payload_len = skb_shinfo(skb)->gso_size + SKB_GSO_CB(skb)->data_offset + skb->head - (unsigned char *)(ipv6h + 1); else payload_len = skb->len - nhoff - sizeof(*ipv6h); ipv6h->payload_len = htons(payload_len); 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)); skb_gro_frag0_invalidate(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; /* If the previous IP ID value was based on an atomic * datagram we can overwrite the value and ignore it. */ if (NAPI_GRO_CB(skb)->is_atomic) NAPI_GRO_CB(p)->flush_id = 0; } NAPI_GRO_CB(skb)->is_atomic = true; 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 struct sk_buff **sit_ip6ip6_gro_receive(struct sk_buff **head, struct sk_buff *skb) { /* Common GRO receive for SIT and IP6IP6 */ if (NAPI_GRO_CB(skb)->encap_mark) { NAPI_GRO_CB(skb)->flush = 1; return NULL; } NAPI_GRO_CB(skb)->encap_mark = 1; return ipv6_gro_receive(head, skb); } static struct sk_buff **ip4ip6_gro_receive(struct sk_buff **head, struct sk_buff *skb) { /* Common GRO receive for SIT and IP6IP6 */ if (NAPI_GRO_CB(skb)->encap_mark) { NAPI_GRO_CB(skb)->flush = 1; return NULL; } NAPI_GRO_CB(skb)->encap_mark = 1; return inet_gro_receive(head, skb); } 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; if (skb->encapsulation) skb_set_inner_network_header(skb, nhoff); 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 int sit_gro_complete(struct sk_buff *skb, int nhoff) { skb->encapsulation = 1; skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4; return ipv6_gro_complete(skb, nhoff); } static int ip6ip6_gro_complete(struct sk_buff *skb, int nhoff) { skb->encapsulation = 1; skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6; return ipv6_gro_complete(skb, nhoff); } static int ip4ip6_gro_complete(struct sk_buff *skb, int nhoff) { skb->encapsulation = 1; skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6; return inet_gro_complete(skb, nhoff); } 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 = sit_ip6ip6_gro_receive, .gro_complete = sit_gro_complete, }, }; static const struct net_offload ip4ip6_offload = { .callbacks = { .gso_segment = inet_gso_segment, .gro_receive = ip4ip6_gro_receive, .gro_complete = ip4ip6_gro_complete, }, }; static const struct net_offload ip6ip6_offload = { .callbacks = { .gso_segment = ipv6_gso_segment, .gro_receive = sit_ip6ip6_gro_receive, .gro_complete = ip6ip6_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 (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); inet6_add_offload(&ip6ip6_offload, IPPROTO_IPV6); inet6_add_offload(&ip4ip6_offload, IPPROTO_IPIP); return 0; } fs_initcall(ipv6_offload_init);