net: ensure correct skb->tstamp in various fragmenters

Thomas found that some forwarded packets would be stuck
in FQ packet scheduler because their skb->tstamp contained
timestamps far in the future.

We thought we addressed this point in commit 7a510a5f3de3
("net: clear skb->tstamp in forwarding paths") but there
is still an issue when/if a packet needs to be fragmented.

In order to meet EDT requirements, we have to make sure all
fragments get the original skb->tstamp.

Note that this original skb->tstamp should be zero in
forwarding path, but might have a non zero value in
output path if user decided so.

Fixes: 8932dea156bd ("tcp/fq: move back to CLOCK_MONOTONIC")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Thomas Bartschies <Thomas.Bartschies@cvk.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/bridge/netfilter/nf_conntrack_bridge.c b/net/bridge/netfilter/nf_conntrack_bridge.c
index 8842798c29e636ac2dbfe01f0bf2ba2f2d398c44..506d6141e44eea67ccc34123ad4250a19bcc7ab7 100644 (file)
--- a/net/bridge/netfilter/nf_conntrack_bridge.c
+++ b/net/bridge/netfilter/nf_conntrack_bridge.c
@@ -33,6 +33,7 @@ static int nf_br_ip_fragment(struct net *net, struct sock *sk,
 {
        int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
        unsigned int hlen, ll_rs, mtu;
+       ktime_t tstamp = skb->tstamp;
        struct ip_frag_state state;
        struct iphdr *iph;
        int err;
@@ -80,6 +81,7 @@ static int nf_br_ip_fragment(struct net *net, struct sock *sk,
                        if (iter.frag)
                                ip_fraglist_prepare(skb, &iter);
 
+                       skb->tstamp = tstamp;
                        err = output(net, sk, data, skb);
                        if (err || !iter.frag)
                                break;
@@ -104,6 +106,7 @@ slow_path:
                        goto blackhole;
                }
 
+               skb2->tstamp = tstamp;
                err = output(net, sk, data, skb2);
                if (err)
                        goto blackhole;

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 28fca408812c5576fc4ea957c1c4dec97ec8faf3..814b9b8882a0237bffd869cb13739e03af227f30 100644 (file)
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -771,6 +771,7 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
        struct rtable *rt = skb_rtable(skb);
        unsigned int mtu, hlen, ll_rs;
        struct ip_fraglist_iter iter;
+       ktime_t tstamp = skb->tstamp;
        struct ip_frag_state state;
        int err = 0;
 
@@ -846,6 +847,7 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
                                ip_fraglist_prepare(skb, &iter);
                        }
 
+                       skb->tstamp = tstamp;
                        err = output(net, sk, skb);
 
                        if (!err)
@@ -900,6 +902,7 @@ slow_path:
                /*
                 *      Put this fragment into the sending queue.
                 */
+               skb2->tstamp = tstamp;
                err = output(net, sk, skb2);
                if (err)
                        goto fail;

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index edadee4a7e76105f737d705052db8f5bbc6c0152..71827b56c0063b56bcfbef4bd8910ddcec035824 100644 (file)
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -768,6 +768,7 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
                                inet6_sk(skb->sk) : NULL;
        struct ip6_frag_state state;
        unsigned int mtu, hlen, nexthdr_offset;
+       ktime_t tstamp = skb->tstamp;
        int hroom, err = 0;
        __be32 frag_id;
        u8 *prevhdr, nexthdr = 0;
@@ -855,6 +856,7 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
                        if (iter.frag)
                                ip6_fraglist_prepare(skb, &iter);
 
+                       skb->tstamp = tstamp;
                        err = output(net, sk, skb);
                        if (!err)
                                IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
@@ -913,6 +915,7 @@ slow_path:
                /*
                 *      Put this fragment into the sending queue.
                 */
+               frag->tstamp = tstamp;
                err = output(net, sk, frag);
                if (err)
                        goto fail;

diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
index a9bff556d3b2ddd5334d20a63210bad0dfa6cd2d..409e79b84a830dd22ffe7728f45d9dc65ec01df4 100644 (file)
--- a/net/ipv6/netfilter.c
+++ b/net/ipv6/netfilter.c
@@ -119,6 +119,7 @@ int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
                                  struct sk_buff *))
 {
        int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
+       ktime_t tstamp = skb->tstamp;
        struct ip6_frag_state state;
        u8 *prevhdr, nexthdr = 0;
        unsigned int mtu, hlen;
@@ -183,6 +184,7 @@ int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
                        if (iter.frag)
                                ip6_fraglist_prepare(skb, &iter);
 
+                       skb->tstamp = tstamp;
                        err = output(net, sk, data, skb);
                        if (err || !iter.frag)
                                break;
@@ -215,6 +217,7 @@ slow_path:
                        goto blackhole;
                }
 
+               skb2->tstamp = tstamp;
                err = output(net, sk, data, skb2);
                if (err)
                        goto blackhole;