diff mbox series

[v4,net-next,06/12] ipv6/gro: insert temporary HBH/jumbo header

Message ID 20220506153048.3695721-7-eric.dumazet@gmail.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series tcp: BIG TCP implementation | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/cc_maintainers warning 2 maintainers not CCed: yoshfuji@linux-ipv6.org dsahern@kernel.org
netdev/build_clang success Errors and warnings before: 9 this patch: 9
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 45 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Eric Dumazet May 6, 2022, 3:30 p.m. UTC 
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 mbox series

Patch

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))