diff options
author | Eric Dumazet <edumazet@google.com> | 2018-10-10 12:29:58 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-08 11:25:31 +0100 |
commit | b047c796dedca591d1a3dc1ba8166d5082c337ef (patch) | |
tree | 296736ae6d4de9724bb6f9768061cbcc961b39aa /net/ipv4 | |
parent | cf2b9e68a684bf8dd6c1a7671f59faaab8e4ca2c (diff) |
inet: frags: get rif of inet_frag_evicting()
commit 399d1404be660d355192ff4df5ccc3f4159ec1e4 upstream.
This refactors ip_expire() since one indentation level is removed.
Note: in the future, we should try hard to avoid the skb_clone()
since this is a serious performance cost.
Under DDOS, the ICMP message wont be sent because of rate limits.
Fact that ip6_expire_frag_queue() does not use skb_clone() is
disturbing too. Presumably IPv6 should have the same
issue than the one we fixed in commit ec4fbd64751d
("inet: frag: release spinlock before calling icmp_send()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv4')
-rw-r--r-- | net/ipv4/ip_fragment.c | 65 |
1 files changed, 32 insertions, 33 deletions
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index 44a3982563cc..e0465ad21868 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -143,8 +143,11 @@ static bool frag_expire_skip_icmp(u32 user) */ static void ip_expire(unsigned long arg) { - struct ipq *qp; + struct sk_buff *clone, *head; + const struct iphdr *iph; struct net *net; + struct ipq *qp; + int err; qp = container_of((struct inet_frag_queue *) arg, struct ipq, q); net = container_of(qp->q.net, struct net, ipv4.frags); @@ -158,45 +161,41 @@ static void ip_expire(unsigned long arg) ipq_kill(qp); IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS); - if (!inet_frag_evicting(&qp->q)) { - struct sk_buff *clone, *head = qp->q.fragments; - const struct iphdr *iph; - int err; + head = qp->q.fragments; - IP_INC_STATS_BH(net, IPSTATS_MIB_REASMTIMEOUT); + IP_INC_STATS_BH(net, IPSTATS_MIB_REASMTIMEOUT); - if (!(qp->q.flags & INET_FRAG_FIRST_IN) || !qp->q.fragments) - goto out; + if (!(qp->q.flags & INET_FRAG_FIRST_IN) || !head) + goto out; - head->dev = dev_get_by_index_rcu(net, qp->iif); - if (!head->dev) - goto out; + head->dev = dev_get_by_index_rcu(net, qp->iif); + if (!head->dev) + goto out; - /* skb has no dst, perform route lookup again */ - iph = ip_hdr(head); - err = ip_route_input_noref(head, iph->daddr, iph->saddr, + /* skb has no dst, perform route lookup again */ + iph = ip_hdr(head); + err = ip_route_input_noref(head, iph->daddr, iph->saddr, iph->tos, head->dev); - if (err) - goto out; + if (err) + goto out; - /* Only an end host needs to send an ICMP - * "Fragment Reassembly Timeout" message, per RFC792. - */ - if (frag_expire_skip_icmp(qp->q.key.v4.user) && - (skb_rtable(head)->rt_type != RTN_LOCAL)) - goto out; - - clone = skb_clone(head, GFP_ATOMIC); - - /* Send an ICMP "Fragment Reassembly Timeout" message. */ - if (clone) { - spin_unlock(&qp->q.lock); - icmp_send(clone, ICMP_TIME_EXCEEDED, - ICMP_EXC_FRAGTIME, 0); - consume_skb(clone); - goto out_rcu_unlock; - } + /* Only an end host needs to send an ICMP + * "Fragment Reassembly Timeout" message, per RFC792. + */ + if (frag_expire_skip_icmp(qp->q.key.v4.user) && + (skb_rtable(head)->rt_type != RTN_LOCAL)) + goto out; + + clone = skb_clone(head, GFP_ATOMIC); + + /* Send an ICMP "Fragment Reassembly Timeout" message. */ + if (clone) { + spin_unlock(&qp->q.lock); + icmp_send(clone, ICMP_TIME_EXCEEDED, + ICMP_EXC_FRAGTIME, 0); + consume_skb(clone); + goto out_rcu_unlock; } out: spin_unlock(&qp->q.lock); |