This patch postpones the delivery_time clearing until the stack knows the skb is being delivered locally. That will allow other kernel forwarding path (e.g. ip[6]_forward) to keep the delivery_time also. An earlier attempt was to do skb_clear_delivery_time() in ip_local_deliver() and ip6_input(). The discussion [0] requested to move it one step later into ip_local_deliver_finish() and ip6_input_finish() so that the delivery_time can be kept for the ip_vs forwarding path also. To do that, this patch also needs to take care of the (rcv) timestamp usecase in ip_is_fragment(). It needs to expect delivery_time in the skb->tstamp, so it needs to save the mono_delivery_time bit in inet_frag_queue such that the delivery_time (if any) can be restored in the final defragmented skb. The ipv6 defrag is done in ip6_protocol_deliver_rcu() when figuring out how to handle nexthdr and IPPROTO_FRAGMENT (44) is one of the ipv6 extension header. ip6_protocol_deliver_rcu() is after ip6_input_finish() where the skb_clear_delivery_time() has already been done, so change is not needed. [0]: https://lore.kernel.org/netdev/ca728d81-80e8-3767-d5e-d44f6ad96e43@xxxxxx/ Signed-off-by: Martin KaFai Lau <kafai@xxxxxx> --- include/net/inet_frag.h | 1 + net/core/dev.c | 1 - net/ipv4/inet_fragment.c | 1 + net/ipv4/ip_fragment.c | 1 + net/ipv4/ip_input.c | 1 + net/ipv6/ip6_input.c | 1 + 6 files changed, 5 insertions(+), 1 deletion(-) diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h index 63540be0fc34..c0e517f31d82 100644 --- a/include/net/inet_frag.h +++ b/include/net/inet_frag.h @@ -90,6 +90,7 @@ struct inet_frag_queue { ktime_t stamp; int len; int meat; + bool mono_delivery_time; __u8 flags; u16 max_size; struct fqdir *fqdir; diff --git a/net/core/dev.c b/net/core/dev.c index f41707ab2fb9..041cef7473fd 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5222,7 +5222,6 @@ static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc, goto out; } #endif - skb_clear_delivery_time(skb); skb_reset_redirect(skb); skip_classify: if (pfmemalloc && !skb_pfmemalloc_protocol(skb)) diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c index 341096807100..63948f6aeca0 100644 --- a/net/ipv4/inet_fragment.c +++ b/net/ipv4/inet_fragment.c @@ -572,6 +572,7 @@ void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head, skb_mark_not_on_list(head); head->prev = NULL; head->tstamp = q->stamp; + head->mono_delivery_time = q->mono_delivery_time; } EXPORT_SYMBOL(inet_frag_reasm_finish); diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index fad803d2d711..fb153569889e 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -349,6 +349,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) qp->iif = dev->ifindex; qp->q.stamp = skb->tstamp; + qp->q.mono_delivery_time = skb->mono_delivery_time; qp->q.meat += skb->len; qp->ecn |= ecn; add_frag_mem_limit(qp->q.fqdir, skb->truesize); diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c index d94f9f7e60c3..95f7bb052784 100644 --- a/net/ipv4/ip_input.c +++ b/net/ipv4/ip_input.c @@ -226,6 +226,7 @@ void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int protocol) static int ip_local_deliver_finish(struct net *net, struct sock *sk, struct sk_buff *skb) { + skb_clear_delivery_time(skb); __skb_pull(skb, skb_network_header_len(skb)); rcu_read_lock(); diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c index d4b1e2c5aa76..5b5ea35635f9 100644 --- a/net/ipv6/ip6_input.c +++ b/net/ipv6/ip6_input.c @@ -459,6 +459,7 @@ void ip6_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int nexthdr, static int ip6_input_finish(struct net *net, struct sock *sk, struct sk_buff *skb) { + skb_clear_delivery_time(skb); rcu_read_lock(); ip6_protocol_deliver_rcu(net, skb, 0, false); rcu_read_unlock(); -- 2.30.2
