[PATCH net-next 3/8] rxrpc: Break MTU determination from ICMP into its own function
From: David Howells <dhowells@redhat.com>
Date: 2016-06-15 16:42:05
Also in:
lkml
Subsystem:
networking [general], rxrpc sockets (af_rxrpc), the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Howells, Marc Dionne, Linus Torvalds
Break MTU determination from ICMP out into its own function to reduce the complexity of the error report handler. Signed-off-by: David Howells <dhowells@redhat.com> --- net/rxrpc/peer_event.c | 93 ++++++++++++++++++++++++++++-------------------- 1 file changed, 54 insertions(+), 39 deletions(-)
diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c
index 2c2df3a5d1b9..80de84257227 100644
--- a/net/rxrpc/peer_event.c
+++ b/net/rxrpc/peer_event.c@@ -72,6 +72,45 @@ static struct rxrpc_peer *rxrpc_lookup_peer_icmp_rcu(struct rxrpc_local *local, } /* + * Handle an MTU/fragmentation problem. + */ +static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, struct sock_exterr_skb *serr) +{ + u32 mtu = serr->ee.ee_info; + + _net("Rx ICMP Fragmentation Needed (%d)", mtu); + + /* wind down the local interface MTU */ + if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) { + peer->if_mtu = mtu; + _net("I/F MTU %u", mtu); + } + + if (mtu == 0) { + /* they didn't give us a size, estimate one */ + mtu = peer->if_mtu; + if (mtu > 1500) { + mtu >>= 1; + if (mtu < 1500) + mtu = 1500; + } else { + mtu -= 100; + if (mtu < peer->hdrsize) + mtu = peer->hdrsize + 4; + } + } + + if (mtu < peer->mtu) { + spin_lock_bh(&peer->lock); + peer->mtu = mtu; + peer->maxdata = peer->mtu - peer->hdrsize; + spin_unlock_bh(&peer->lock); + _net("Net MTU %u (maxdata %u)", + peer->mtu, peer->maxdata); + } +} + +/* * handle an error received on the local endpoint */ void rxrpc_error_report(struct sock *sk)
@@ -126,50 +165,26 @@ void rxrpc_error_report(struct sock *sk) return; } - if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP && - serr->ee.ee_type == ICMP_DEST_UNREACH && - serr->ee.ee_code == ICMP_FRAG_NEEDED - ) { - u32 mtu = serr->ee.ee_info; - - _net("Rx Received ICMP Fragmentation Needed (%d)", mtu); - - /* wind down the local interface MTU */ - if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) { - peer->if_mtu = mtu; - _net("I/F MTU %u", mtu); - } - - if (mtu == 0) { - /* they didn't give us a size, estimate one */ - mtu = peer->if_mtu; - if (mtu > 1500) { - mtu >>= 1; - if (mtu < 1500) - mtu = 1500; - } else { - mtu -= 100; - if (mtu < peer->hdrsize) - mtu = peer->hdrsize + 4; - } - } - - if (mtu < peer->mtu) { - spin_lock_bh(&peer->lock); - peer->mtu = mtu; - peer->maxdata = peer->mtu - peer->hdrsize; - spin_unlock_bh(&peer->lock); - _net("Net MTU %u (maxdata %u)", - peer->mtu, peer->maxdata); - } + if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP && + serr->ee.ee_type == ICMP_DEST_UNREACH && + serr->ee.ee_code == ICMP_FRAG_NEEDED)) { + rxrpc_adjust_mtu(peer, serr); + rxrpc_free_skb(skb); + skb = NULL; + goto out; } +out: rcu_read_unlock(); rxrpc_put_peer(peer); - /* pass the transport ref to error_handler to release */ - skb_queue_tail(&trans->error_queue, skb); - rxrpc_queue_work(&trans->error_handler); + if (skb) { + /* pass the transport ref to error_handler to release */ + skb_queue_tail(&trans->error_queue, skb); + rxrpc_queue_work(&trans->error_handler); + } else { + rxrpc_put_transport(trans); + } _leave(""); }