[PATCH v5 net-next 07/13] ipv6/gro: insert temporary HBH/jumbo header
From: Eric Dumazet <hidden>
Date: 2022-05-09 22:24:07
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
From: Eric Dumazet <edumazet@google.com> Following patch will add GRO_IPV6_MAX_SIZE, allowing gro to build BIG TCP ipv6 packets (bigger than 64K). This patch changes ipv6_gro_complete() to insert a HBH/jumbo header so that resulting packet can go through IPv6/TCP stacks. Signed-off-by: Eric Dumazet <edumazet@google.com> --- net/ipv6/ip6_offload.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-)
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index a6a6c1539c28d242ef8c35fcd5ce900512ce912d..d12dba2dd5354dbb79bb80df4038dec2544cddeb 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c@@ -342,15 +342,43 @@ static struct sk_buff *ip4ip6_gro_receive(struct list_head *head, INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff) { const struct net_offload *ops; - struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + nhoff); + struct ipv6hdr *iph; int err = -ENOSYS; + u32 payload_len; if (skb->encapsulation) { skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6)); skb_set_inner_network_header(skb, nhoff); } - iph->payload_len = htons(skb->len - nhoff - sizeof(*iph)); + payload_len = skb->len - nhoff - sizeof(*iph); + if (unlikely(payload_len > IPV6_MAXPLEN)) { + struct hop_jumbo_hdr *hop_jumbo; + int hoplen = sizeof(*hop_jumbo); + + /* Move network header left */ + memmove(skb_mac_header(skb) - hoplen, skb_mac_header(skb), + skb->transport_header - skb->mac_header); + skb->data -= hoplen; + skb->len += hoplen; + skb->mac_header -= hoplen; + skb->network_header -= hoplen; + iph = (struct ipv6hdr *)(skb->data + nhoff); + hop_jumbo = (struct hop_jumbo_hdr *)(iph + 1); + + /* Build hop-by-hop options */ + hop_jumbo->nexthdr = iph->nexthdr; + hop_jumbo->hdrlen = 0; + hop_jumbo->tlv_type = IPV6_TLV_JUMBO; + hop_jumbo->tlv_len = 4; + hop_jumbo->jumbo_payload_len = htonl(payload_len + hoplen); + + iph->nexthdr = NEXTHDR_HOP; + iph->payload_len = 0; + } else { + iph = (struct ipv6hdr *)(skb->data + nhoff); + iph->payload_len = htons(payload_len); + } nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops); if (WARN_ON(!ops || !ops->callbacks.gro_complete))
--
2.36.0.512.ge40c2bad7a-goog