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| author | Hiroaki SHIMODA <shimoda.hiroaki@gmail.com> | 2011-03-09 20:09:58 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-03-13 18:37:49 -0700 |
| commit | 46af31800b6916c92fffa529dc3c357008da957d (patch) | |
| tree | 2c66ee7b78527da504a294f1bd8a2a899623fead | |
| parent | bef55aebd560c5a6f8883c421abccee39978c58c (diff) | |
| download | linux-stable-46af31800b6916c92fffa529dc3c357008da957d.tar.gz linux-stable-46af31800b6916c92fffa529dc3c357008da957d.tar.bz2 linux-stable-46af31800b6916c92fffa529dc3c357008da957d.zip | |
ipv4: Fix PMTU update.
On current net-next-2.6, when Linux receives ICMP Type: 3, Code: 4
(Destination unreachable (Fragmentation needed)),
icmp_unreach
-> ip_rt_frag_needed
(peer->pmtu_expires is set here)
-> tcp_v4_err
-> do_pmtu_discovery
-> ip_rt_update_pmtu
(peer->pmtu_expires is already set,
so check_peer_pmtu is skipped.)
-> check_peer_pmtu
check_peer_pmtu is skipped and MTU is not updated.
To fix this, let check_peer_pmtu execute unconditionally.
And some minor fixes
1) Avoid potential peer->pmtu_expires set to be zero.
2) In check_peer_pmtu, argument of time_before is reversed.
3) check_peer_pmtu expects peer->pmtu_orig is initialized as zero,
but not initialized.
Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/inetpeer.c | 1 | ||||
| -rw-r--r-- | net/ipv4/route.c | 22 |
2 files changed, 18 insertions, 5 deletions
diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c index 6442c35edb0b..86b1d0878dff 100644 --- a/net/ipv4/inetpeer.c +++ b/net/ipv4/inetpeer.c @@ -511,6 +511,7 @@ struct inet_peer *inet_getpeer(struct inetpeer_addr *daddr, int create) p->rate_tokens = 0; p->rate_last = 0; p->pmtu_expires = 0; + p->pmtu_orig = 0; memset(&p->redirect_learned, 0, sizeof(p->redirect_learned)); INIT_LIST_HEAD(&p->unused); diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 5655095a89e0..209989cf7d1b 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1533,9 +1533,15 @@ unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph, if (mtu < ip_rt_min_pmtu) mtu = ip_rt_min_pmtu; if (!peer->pmtu_expires || mtu < peer->pmtu_learned) { + unsigned long pmtu_expires; + + pmtu_expires = jiffies + ip_rt_mtu_expires; + if (!pmtu_expires) + pmtu_expires = 1UL; + est_mtu = mtu; peer->pmtu_learned = mtu; - peer->pmtu_expires = jiffies + ip_rt_mtu_expires; + peer->pmtu_expires = pmtu_expires; } inet_putpeer(peer); @@ -1549,7 +1555,7 @@ static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer) { unsigned long expires = peer->pmtu_expires; - if (time_before(expires, jiffies)) { + if (time_before(jiffies, expires)) { u32 orig_dst_mtu = dst_mtu(dst); if (peer->pmtu_learned < orig_dst_mtu) { if (!peer->pmtu_orig) @@ -1574,14 +1580,20 @@ static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu) if (mtu < ip_rt_min_pmtu) mtu = ip_rt_min_pmtu; if (!peer->pmtu_expires || mtu < peer->pmtu_learned) { + unsigned long pmtu_expires; + + pmtu_expires = jiffies + ip_rt_mtu_expires; + if (!pmtu_expires) + pmtu_expires = 1UL; + peer->pmtu_learned = mtu; - peer->pmtu_expires = jiffies + ip_rt_mtu_expires; + peer->pmtu_expires = pmtu_expires; atomic_inc(&__rt_peer_genid); rt->rt_peer_genid = rt_peer_genid(); - - check_peer_pmtu(dst, peer); } + check_peer_pmtu(dst, peer); + inet_putpeer(peer); } } |