diff options
| -rw-r--r-- | net/ipv4/route.c | 78 |
1 files changed, 44 insertions, 34 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 52b0b956508..045f0ec6a4a 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1316,6 +1316,23 @@ reject_redirect: ; } +static bool peer_pmtu_expired(struct inet_peer *peer) +{ + unsigned long orig = ACCESS_ONCE(peer->pmtu_expires); + + return orig && + time_after_eq(jiffies, orig) && + cmpxchg(&peer->pmtu_expires, orig, 0) == orig; +} + +static bool peer_pmtu_cleaned(struct inet_peer *peer) +{ + unsigned long orig = ACCESS_ONCE(peer->pmtu_expires); + + return orig && + cmpxchg(&peer->pmtu_expires, orig, 0) == orig; +} + static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) { struct rtable *rt = (struct rtable *)dst; @@ -1331,14 +1348,8 @@ static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) rt_genid(dev_net(dst->dev))); rt_del(hash, rt); ret = NULL; - } else if (rt->peer && - rt->peer->pmtu_expires && - time_after_eq(jiffies, rt->peer->pmtu_expires)) { - unsigned long orig = rt->peer->pmtu_expires; - - if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig) - dst_metric_set(dst, RTAX_MTU, - rt->peer->pmtu_orig); + } else if (rt->peer && peer_pmtu_expired(rt->peer)) { + dst_metric_set(dst, RTAX_MTU, rt->peer->pmtu_orig); } } return ret; @@ -1531,8 +1542,10 @@ unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph, static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer) { - unsigned long expires = peer->pmtu_expires; + unsigned long expires = ACCESS_ONCE(peer->pmtu_expires); + if (!expires) + return; if (time_before(jiffies, expires)) { u32 orig_dst_mtu = dst_mtu(dst); if (peer->pmtu_learned < orig_dst_mtu) { @@ -1555,10 +1568,11 @@ static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu) rt_bind_peer(rt, rt->rt_dst, 1); peer = rt->peer; if (peer) { + unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires); + if (mtu < ip_rt_min_pmtu) mtu = ip_rt_min_pmtu; - if (!peer->pmtu_expires || mtu < peer->pmtu_learned) { - unsigned long pmtu_expires; + if (!pmtu_expires || mtu < peer->pmtu_learned) { pmtu_expires = jiffies + ip_rt_mtu_expires; if (!pmtu_expires) @@ -1612,13 +1626,14 @@ static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) rt_bind_peer(rt, rt->rt_dst, 0); peer = rt->peer; - if (peer && peer->pmtu_expires) + if (peer) { check_peer_pmtu(dst, peer); - if (peer && peer->redirect_learned.a4 && - peer->redirect_learned.a4 != rt->rt_gateway) { - if (check_peer_redir(dst, peer)) - return NULL; + if (peer->redirect_learned.a4 && + peer->redirect_learned.a4 != rt->rt_gateway) { + if (check_peer_redir(dst, peer)) + return NULL; + } } rt->rt_peer_genid = rt_peer_genid(); @@ -1649,14 +1664,8 @@ static void ipv4_link_failure(struct sk_buff *skb) icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); rt = skb_rtable(skb); - if (rt && - rt->peer && - rt->peer->pmtu_expires) { - unsigned long orig = rt->peer->pmtu_expires; - - if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig) - dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig); - } + if (rt && rt->peer && peer_pmtu_cleaned(rt->peer)) + dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig); } static int ip_rt_bug(struct sk_buff *skb) @@ -1770,8 +1779,7 @@ static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4, sizeof(u32) * RTAX_MAX); dst_init_metrics(&rt->dst, peer->metrics, false); - if (peer->pmtu_expires) - check_peer_pmtu(&rt->dst, peer); + check_peer_pmtu(&rt->dst, peer); if (peer->redirect_learned.a4 && peer->redirect_learned.a4 != rt->rt_gateway) { rt->rt_gateway = peer->redirect_learned.a4; @@ -2775,7 +2783,8 @@ static int rt_fill_info(struct net *net, struct rtable *rt = skb_rtable(skb); struct rtmsg *r; struct nlmsghdr *nlh; - long expires; + long expires = 0; + const struct inet_peer *peer = rt->peer; u32 id = 0, ts = 0, tsage = 0, error; nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags); @@ -2823,15 +2832,16 @@ static int rt_fill_info(struct net *net, NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark); error = rt->dst.error; - expires = (rt->peer && rt->peer->pmtu_expires) ? - rt->peer->pmtu_expires - jiffies : 0; - if (rt->peer) { + if (peer) { inet_peer_refcheck(rt->peer); - id = atomic_read(&rt->peer->ip_id_count) & 0xffff; - if (rt->peer->tcp_ts_stamp) { - ts = rt->peer->tcp_ts; - tsage = get_seconds() - rt->peer->tcp_ts_stamp; + id = atomic_read(&peer->ip_id_count) & 0xffff; + if (peer->tcp_ts_stamp) { + ts = peer->tcp_ts; + tsage = get_seconds() - peer->tcp_ts_stamp; } + expires = ACCESS_ONCE(peer->pmtu_expires); + if (expires) + expires -= jiffies; } if (rt_is_input_route(rt)) { |