6.6-stable review patch. If anyone has any objections, please let me know.
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From: Richard Gobert richardbgobert@gmail.com
[ Upstream commit dff0b0161ad571f888d37f5e7163a07dcafdef60 ]
The existing code always pulls the IPv6 header and sets the transport offset initially. Then optionally again pulls any extension headers in ipv6_gso_pull_exthdrs and sets the transport offset again on return from that call. skb->data is set at the start of the first extension header before calling ipv6_gso_pull_exthdrs, and must disable the frag0 optimization because that function uses pskb_may_pull/pskb_pull instead of skb_gro_ helpers. It sets the GRO offset to the TCP header with skb_gro_pull and sets the transport header. Then returns skb->data to its position before this block.
This commit introduces a new helper function - ipv6_gro_pull_exthdrs - which is used in ipv6_gro_receive to pull ipv6 ext headers instead of ipv6_gso_pull_exthdrs. Thus, there is no modification of skb->data, all operations use skb_gro_* helpers, and the frag0 fast path can be taken for IPv6 packets with ext headers.
Signed-off-by: Richard Gobert richardbgobert@gmail.com Reviewed-by: Willem de Bruijn willemb@google.com Reviewed-by: David Ahern dsahern@kernel.org Reviewed-by: Eric Dumazet edumazet@google.com Link: https://lore.kernel.org/r/504130f6-b56c-4dcc-882c-97942c59f5b7@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: 5ef31ea5d053 ("net: gro: fix udp bad offset in socket lookup by adding {inner_}network_offset to napi_gro_cb") Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv6/ip6_offload.c | 51 +++++++++++++++++++++++++++++++++--------- 1 file changed, 41 insertions(+), 10 deletions(-)
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c index d6314287338da..f6e5fcdf041d1 100644 --- a/net/ipv6/ip6_offload.c +++ b/net/ipv6/ip6_offload.c @@ -37,6 +37,40 @@ INDIRECT_CALL_L4(cb, f2, f1, head, skb); \ })
+static int ipv6_gro_pull_exthdrs(struct sk_buff *skb, int off, int proto) +{ + const struct net_offload *ops = NULL; + struct ipv6_opt_hdr *opth; + + for (;;) { + int len; + + ops = rcu_dereference(inet6_offloads[proto]); + + if (unlikely(!ops)) + break; + + if (!(ops->flags & INET6_PROTO_GSO_EXTHDR)) + break; + + opth = skb_gro_header(skb, off + sizeof(*opth), off); + if (unlikely(!opth)) + break; + + len = ipv6_optlen(opth); + + opth = skb_gro_header(skb, off + len, off); + if (unlikely(!opth)) + break; + proto = opth->nexthdr; + + off += len; + } + + skb_gro_pull(skb, off - skb_network_offset(skb)); + return proto; +} + static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto) { const struct net_offload *ops = NULL; @@ -206,28 +240,25 @@ INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head, 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); + flush += ntohs(iph->payload_len) != skb->len - hlen;
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)); + proto = ipv6_gro_pull_exthdrs(skb, hlen, proto);
ops = rcu_dereference(inet6_offloads[proto]); if (!ops || !ops->callbacks.gro_receive) goto out;
- iph = ipv6_hdr(skb); + iph = skb_gro_network_header(skb); + } else { + skb_gro_pull(skb, sizeof(*iph)); }
+ skb_set_transport_header(skb, skb_gro_offset(skb)); + NAPI_GRO_CB(skb)->proto = proto;
flush--;