int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask) { int err; if (likely(!skb->encapsulation)) { skb_reset_inner_headers(skb); skb->encapsulation = 1; } if (skb_is_gso(skb)) { err = skb_header_unclone(skb, GFP_ATOMIC); if (unlikely(err)) return err; skb_shinfo(skb)->gso_type |= gso_type_mask; return 0; } if (skb->ip_summed != CHECKSUM_PARTIAL) { skb->ip_summed = CHECKSUM_NONE; /* We clear encapsulation here to prevent badly-written * drivers potentially deciding to offload an inner checksum * if we set CHECKSUM_PARTIAL on the outer header. * This should go away when the drivers are all fixed. */ skb->encapsulation = 0; } return 0; }
struct sk_buff *gre_handle_offloads(struct sk_buff *skb, bool gre_csum) { int err; if (likely(!skb->encapsulation)) { skb_reset_inner_headers(skb); skb->encapsulation = 1; } if (skb_is_gso(skb)) { err = skb_unclone(skb, GFP_ATOMIC); if (unlikely(err)) goto error; skb_shinfo(skb)->gso_type |= SKB_GSO_GRE; return skb; } else if (skb->ip_summed == CHECKSUM_PARTIAL && gre_csum) { err = skb_checksum_help(skb); if (unlikely(err)) goto error; } else if (skb->ip_summed != CHECKSUM_PARTIAL) skb->ip_summed = CHECKSUM_NONE; return skb; error: kfree_skb(skb); return ERR_PTR(err); }
static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, const struct iphdr *tnl_params, __be16 proto) { struct ip_tunnel *tunnel = netdev_priv(dev); struct tnl_ptk_info tpi; if (likely(!skb->encapsulation)) { skb_reset_inner_headers(skb); skb->encapsulation = 1; } tpi.flags = tunnel->parms.o_flags; tpi.proto = proto; tpi.key = tunnel->parms.o_key; if (tunnel->parms.o_flags & TUNNEL_SEQ) tunnel->o_seqno++; tpi.seq = htonl(tunnel->o_seqno); /* Push GRE header. */ skb = gre_build_header(skb, &tpi, tunnel->hlen); if (unlikely(!skb)) { dev->stats.tx_dropped++; return; } ip_tunnel_xmit(skb, dev, tnl_params); }
int vxlan_xmit_skb(struct vxlan_sock *vs, struct rtable *rt, struct sk_buff *skb, __be32 src, __be32 dst, __u8 tos, __u8 ttl, __be16 df, __be16 src_port, __be16 dst_port, __be32 vni) { struct vxlanhdr *vxh; struct udphdr *uh; int min_headroom; int err; min_headroom = LL_RESERVED_SPACE(rt_dst(rt).dev) + rt_dst(rt).header_len + VXLAN_HLEN + sizeof(struct iphdr) + (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0); /* Need space for new headers (invalidates iph ptr) */ err = skb_cow_head(skb, min_headroom); if (unlikely(err)) { kfree_skb(skb); return err; } if (vlan_tx_tag_present(skb)) { if (unlikely(!vlan_insert_tag_set_proto(skb, skb->vlan_proto, vlan_tx_tag_get(skb)))) return -ENOMEM; vlan_set_tci(skb, 0); } skb_reset_inner_headers(skb); vxh = (struct vxlanhdr *) __skb_push(skb, sizeof(*vxh)); vxh->vx_flags = htonl(VXLAN_FLAGS); vxh->vx_vni = vni; __skb_push(skb, sizeof(*uh)); skb_reset_transport_header(skb); uh = udp_hdr(skb); uh->dest = dst_port; uh->source = src_port; uh->len = htons(skb->len); uh->check = 0; vxlan_set_owner(vs->sock->sk, skb); skb = handle_offloads(skb); if (IS_ERR(skb)) return PTR_ERR(skb); return iptunnel_xmit(vs->sock->sk, rt, skb, src, dst, IPPROTO_UDP, tos, ttl, df, false); }
int ovs_iptunnel_handle_offloads(struct sk_buff *skb, bool csum_help, int gso_type_mask, void (*fix_segment)(struct sk_buff *)) { int err; if (likely(!skb_is_encapsulated(skb))) { skb_reset_inner_headers(skb); #if LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0) skb->encapsulation = 1; #endif } else if (skb_is_gso(skb)) { err = -ENOSYS; goto error; } #if LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0) if (gso_type_mask) fix_segment = NULL; OVS_GSO_CB(skb)->fix_segment = fix_segment; #endif if (skb_is_gso(skb)) { err = skb_unclone(skb, GFP_ATOMIC); if (unlikely(err)) goto error; skb_shinfo(skb)->gso_type |= gso_type_mask; return 0; } #if LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0) /* If packet is not gso and we are resolving any partial checksum, * clear encapsulation flag. This allows setting CHECKSUM_PARTIAL * on the outer header without confusing devices that implement * NETIF_F_IP_CSUM with encapsulation. */ if (csum_help) skb->encapsulation = 0; #endif if (skb->ip_summed == CHECKSUM_PARTIAL && csum_help) { err = skb_checksum_help(skb); if (unlikely(err)) goto error; } else if (skb->ip_summed != CHECKSUM_PARTIAL) skb->ip_summed = CHECKSUM_NONE; return 0; error: return err; }
int rpl_iptunnel_handle_offloads(struct sk_buff *skb, bool csum_help, int gso_type_mask) #endif { int err; if (likely(!skb->encapsulation)) { skb_reset_inner_headers(skb); skb->encapsulation = 1; } if (skb_is_gso(skb)) { err = skb_unclone(skb, GFP_ATOMIC); if (unlikely(err)) goto error; skb_shinfo(skb)->gso_type |= gso_type_mask; goto out; } /* If packet is not gso and we are resolving any partial checksum, * clear encapsulation flag. This allows setting CHECKSUM_PARTIAL * on the outer header without confusing devices that implement * NETIF_F_IP_CSUM with encapsulation. */ if (csum_help) skb->encapsulation = 0; if (skb->ip_summed == CHECKSUM_PARTIAL && csum_help) { err = skb_checksum_help(skb); if (unlikely(err)) goto error; } else if (skb->ip_summed != CHECKSUM_PARTIAL) skb->ip_summed = CHECKSUM_NONE; #if LINUX_VERSION_CODE < KERNEL_VERSION(4,7,0) out: return skb; error: kfree_skb(skb); return ERR_PTR(err); #else out: error: return 0; #endif }
/* * This function assumes it is being called from dev_queue_xmit() * and that skb is filled properly by that function. */ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) { struct ip_tunnel *tunnel = netdev_priv(dev); const struct iphdr *tiph = &tunnel->parms.iph; if (unlikely(skb->protocol != htons(ETH_P_IP))) goto tx_error; if (likely(!skb->encapsulation)) { skb_reset_inner_headers(skb); skb->encapsulation = 1; } ip_tunnel_xmit(skb, dev, tiph, tiph->protocol); return NETDEV_TX_OK; tx_error: dev->stats.tx_errors++; dev_kfree_skb(skb); return NETDEV_TX_OK; }
int ovs_iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask, void (*fix_segment)(struct sk_buff *)) { int err; if (likely(!skb_is_encapsulated(skb))) { skb_reset_inner_headers(skb); skb->encapsulation = 1; } else if (skb_is_gso(skb)) { err = -ENOSYS; goto error; } if (skb_is_gso(skb)) { err = skb_unclone(skb, GFP_ATOMIC); if (unlikely(err)) goto error; skb_shinfo(skb)->gso_type |= gso_type_mask; #ifndef USE_UPSTREAM_TUNNEL_GSO if (gso_type_mask) fix_segment = NULL; OVS_GSO_CB(skb)->fix_segment = fix_segment; #endif return 0; } if (skb->ip_summed != CHECKSUM_PARTIAL) { skb->ip_summed = CHECKSUM_NONE; skb->encapsulation = 0; } return 0; error: return err; }
struct sk_buff *gre_handle_offloads(struct sk_buff *skb, bool gre_csum) { int err; skb_reset_inner_headers(skb); if (skb_is_gso(skb)) { if (gre_csum) OVS_GSO_CB(skb)->fix_segment = gre_csum_fix; } else { if (skb->ip_summed == CHECKSUM_PARTIAL && gre_csum) { err = skb_checksum_help(skb); if (err) goto error; } else if (skb->ip_summed != CHECKSUM_PARTIAL) skb->ip_summed = CHECKSUM_NONE; } return skb; error: kfree_skb(skb); return ERR_PTR(err); }
static struct sk_buff *gre_gso_segment(struct sk_buff *skb, netdev_features_t features) { struct sk_buff *segs = ERR_PTR(-EINVAL); netdev_features_t enc_features; int ghl = GRE_HEADER_SECTION; struct gre_base_hdr *greh; u16 mac_offset = skb->mac_header; int mac_len = skb->mac_len; __be16 protocol = skb->protocol; int tnl_hlen; bool csum; if (unlikely(skb_shinfo(skb)->gso_type & ~(SKB_GSO_TCPV4 | SKB_GSO_TCPV6 | SKB_GSO_UDP | SKB_GSO_DODGY | SKB_GSO_TCP_ECN | SKB_GSO_GRE | SKB_GSO_IPIP))) goto out; if (unlikely(!pskb_may_pull(skb, sizeof(*greh)))) goto out; greh = (struct gre_base_hdr *)skb_transport_header(skb); if (greh->flags & GRE_KEY) ghl += GRE_HEADER_SECTION; if (greh->flags & GRE_SEQ) ghl += GRE_HEADER_SECTION; if (greh->flags & GRE_CSUM) { ghl += GRE_HEADER_SECTION; csum = true; } else csum = false; if (unlikely(!pskb_may_pull(skb, ghl))) goto out; /* setup inner skb. */ skb->protocol = greh->protocol; skb->encapsulation = 0; __skb_pull(skb, ghl); skb_reset_mac_header(skb); skb_set_network_header(skb, skb_inner_network_offset(skb)); skb->mac_len = skb_inner_network_offset(skb); /* segment inner packet. */ enc_features = skb->dev->hw_enc_features & netif_skb_features(skb); segs = skb_mac_gso_segment(skb, enc_features); if (!segs || IS_ERR(segs)) { skb_gso_error_unwind(skb, protocol, ghl, mac_offset, mac_len); goto out; } skb = segs; tnl_hlen = skb_tnl_header_len(skb); do { __skb_push(skb, ghl); if (csum) { __be32 *pcsum; if (skb_has_shared_frag(skb)) { int err; err = __skb_linearize(skb); if (err) { kfree_skb_list(segs); segs = ERR_PTR(err); goto out; } } greh = (struct gre_base_hdr *)(skb->data); pcsum = (__be32 *)(greh + 1); *pcsum = 0; *(__sum16 *)pcsum = csum_fold(skb_checksum(skb, 0, skb->len, 0)); } __skb_push(skb, tnl_hlen - ghl); skb_reset_inner_headers(skb); skb->encapsulation = 1; skb_reset_mac_header(skb); skb_set_network_header(skb, mac_len); skb->mac_len = mac_len; skb->protocol = protocol; } while ((skb = skb->next)); out: return segs; }
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_MPLS | 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 != NULL) 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; }
static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, netdev_features_t features, struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, netdev_features_t features), __be16 new_protocol, bool is_ipv6) { int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); bool remcsum, need_csum, offload_csum, gso_partial; struct sk_buff *segs = ERR_PTR(-EINVAL); struct udphdr *uh = udp_hdr(skb); u16 mac_offset = skb->mac_header; __be16 protocol = skb->protocol; u16 mac_len = skb->mac_len; int udp_offset, outer_hlen; __wsum partial; bool need_ipsec; if (unlikely(!pskb_may_pull(skb, tnl_hlen))) goto out; /* Adjust partial header checksum to negate old length. * We cannot rely on the value contained in uh->len as it is * possible that the actual value exceeds the boundaries of the * 16 bit length field due to the header being added outside of an * IP or IPv6 frame that was already limited to 64K - 1. */ if (skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL) partial = (__force __wsum)uh->len; else partial = (__force __wsum)htonl(skb->len); partial = csum_sub(csum_unfold(uh->check), partial); /* setup inner skb. */ skb->encapsulation = 0; SKB_GSO_CB(skb)->encap_level = 0; __skb_pull(skb, tnl_hlen); skb_reset_mac_header(skb); skb_set_network_header(skb, skb_inner_network_offset(skb)); skb->mac_len = skb_inner_network_offset(skb); skb->protocol = new_protocol; need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM); skb->encap_hdr_csum = need_csum; remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM); skb->remcsum_offload = remcsum; need_ipsec = skb_dst(skb) && dst_xfrm(skb_dst(skb)); /* Try to offload checksum if possible */ offload_csum = !!(need_csum && !need_ipsec && (skb->dev->features & (is_ipv6 ? (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM) : (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM)))); features &= skb->dev->hw_enc_features; /* The only checksum offload we care about from here on out is the * outer one so strip the existing checksum feature flags and * instead set the flag based on our outer checksum offload value. */ if (remcsum) { features &= ~NETIF_F_CSUM_MASK; if (!need_csum || offload_csum) features |= NETIF_F_HW_CSUM; } /* segment inner packet. */ segs = gso_inner_segment(skb, features); if (IS_ERR_OR_NULL(segs)) { skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset, mac_len); goto out; } gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL); outer_hlen = skb_tnl_header_len(skb); udp_offset = outer_hlen - tnl_hlen; skb = segs; do { unsigned int len; if (remcsum) skb->ip_summed = CHECKSUM_NONE; /* Set up inner headers if we are offloading inner checksum */ if (skb->ip_summed == CHECKSUM_PARTIAL) { skb_reset_inner_headers(skb); skb->encapsulation = 1; } skb->mac_len = mac_len; skb->protocol = protocol; __skb_push(skb, outer_hlen); skb_reset_mac_header(skb); skb_set_network_header(skb, mac_len); skb_set_transport_header(skb, udp_offset); len = skb->len - udp_offset; uh = udp_hdr(skb); /* If we are only performing partial GSO the inner header * will be using a length value equal to only one MSS sized * segment instead of the entire frame. */ if (gso_partial && skb_is_gso(skb)) { uh->len = htons(skb_shinfo(skb)->gso_size + SKB_GSO_CB(skb)->data_offset + skb->head - (unsigned char *)uh); } else { uh->len = htons(len); } if (!need_csum) continue; uh->check = ~csum_fold(csum_add(partial, (__force __wsum)htonl(len))); if (skb->encapsulation || !offload_csum) { uh->check = gso_make_checksum(skb, ~uh->check); if (uh->check == 0) uh->check = CSUM_MANGLED_0; } else { skb->ip_summed = CHECKSUM_PARTIAL; skb->csum_start = skb_transport_header(skb) - skb->head; skb->csum_offset = offsetof(struct udphdr, check); } } while ((skb = skb->next)); out: return segs; }
static struct sk_buff *gre_gso_segment(struct sk_buff *skb, netdev_features_t features) { int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); struct sk_buff *segs = ERR_PTR(-EINVAL); u16 mac_offset = skb->mac_header; __be16 protocol = skb->protocol; u16 mac_len = skb->mac_len; int gre_offset, outer_hlen; bool need_csum, ufo; if (unlikely(skb_shinfo(skb)->gso_type & ~(SKB_GSO_TCPV4 | SKB_GSO_TCPV6 | SKB_GSO_UDP | SKB_GSO_DODGY | SKB_GSO_TCP_ECN | SKB_GSO_TCP_FIXEDID | SKB_GSO_GRE | SKB_GSO_GRE_CSUM | SKB_GSO_IPIP | SKB_GSO_SIT | SKB_GSO_PARTIAL))) goto out; if (!skb->encapsulation) goto out; if (unlikely(tnl_hlen < sizeof(struct gre_base_hdr))) goto out; if (unlikely(!pskb_may_pull(skb, tnl_hlen))) goto out; /* setup inner skb. */ skb->encapsulation = 0; SKB_GSO_CB(skb)->encap_level = 0; __skb_pull(skb, tnl_hlen); skb_reset_mac_header(skb); skb_set_network_header(skb, skb_inner_network_offset(skb)); skb->mac_len = skb_inner_network_offset(skb); skb->protocol = skb->inner_protocol; need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_GRE_CSUM); skb->encap_hdr_csum = need_csum; ufo = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP); features &= skb->dev->hw_enc_features; /* The only checksum offload we care about from here on out is the * outer one so strip the existing checksum feature flags based * on the fact that we will be computing our checksum in software. */ if (ufo) { features &= ~NETIF_F_CSUM_MASK; if (!need_csum) features |= NETIF_F_HW_CSUM; } /* segment inner packet. */ segs = skb_mac_gso_segment(skb, features); if (IS_ERR_OR_NULL(segs)) { skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset, mac_len); goto out; } outer_hlen = skb_tnl_header_len(skb); gre_offset = outer_hlen - tnl_hlen; skb = segs; do { struct gre_base_hdr *greh; __sum16 *pcsum; /* Set up inner headers if we are offloading inner checksum */ if (skb->ip_summed == CHECKSUM_PARTIAL) { skb_reset_inner_headers(skb); skb->encapsulation = 1; } skb->mac_len = mac_len; skb->protocol = protocol; __skb_push(skb, outer_hlen); skb_reset_mac_header(skb); skb_set_network_header(skb, mac_len); skb_set_transport_header(skb, gre_offset); if (!need_csum) continue; greh = (struct gre_base_hdr *)skb_transport_header(skb); pcsum = (__sum16 *)(greh + 1); if (skb_is_gso(skb)) { unsigned int partial_adj; /* Adjust checksum to account for the fact that * the partial checksum is based on actual size * whereas headers should be based on MSS size. */ partial_adj = skb->len + skb_headroom(skb) - SKB_GSO_CB(skb)->data_offset - skb_shinfo(skb)->gso_size; *pcsum = ~csum_fold((__force __wsum)htonl(partial_adj)); } else { *pcsum = 0; } *(pcsum + 1) = 0; *pcsum = gso_make_checksum(skb, 0); } while ((skb = skb->next)); out: return segs; }
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 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) { int err = ip6_find_1stfragopt(skb, &prevhdr); if (err < 0) { kfree_skb_list(segs); return ERR_PTR(err); } fptr = (struct frag_hdr *)((u8 *)ipv6h + err); 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; }