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Diffstat (limited to 'net/ipv4/ip_fragment.c')
-rw-r--r--net/ipv4/ip_fragment.c34
1 files changed, 30 insertions, 4 deletions
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 891c72aea52..9f41bd31175 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -32,6 +32,8 @@
#include <linux/netdevice.h>
#include <linux/jhash.h>
#include <linux/random.h>
+#include <net/route.h>
+#include <net/dst.h>
#include <net/sock.h>
#include <net/ip.h>
#include <net/icmp.h>
@@ -205,13 +207,37 @@ static void ip_expire(unsigned long arg)
if ((qp->q.last_in & INET_FRAG_FIRST_IN) && qp->q.fragments != NULL) {
struct sk_buff *head = qp->q.fragments;
- /* Send an ICMP "Fragment Reassembly Timeout" message. */
rcu_read_lock();
head->dev = dev_get_by_index_rcu(net, qp->iif);
- if (head->dev)
- icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
- rcu_read_unlock();
+ if (!head->dev)
+ goto out_rcu_unlock;
+
+ /*
+ * Only search router table for the head fragment,
+ * when defraging timeout at PRE_ROUTING HOOK.
+ */
+ if (qp->user == IP_DEFRAG_CONNTRACK_IN && !skb_dst(head)) {
+ const struct iphdr *iph = ip_hdr(head);
+ int err = ip_route_input(head, iph->daddr, iph->saddr,
+ iph->tos, head->dev);
+ if (unlikely(err))
+ goto out_rcu_unlock;
+
+ /*
+ * Only an end host needs to send an ICMP
+ * "Fragment Reassembly Timeout" message, per RFC792.
+ */
+ if (skb_rtable(head)->rt_type != RTN_LOCAL)
+ goto out_rcu_unlock;
+
+ }
+
+ /* Send an ICMP "Fragment Reassembly Timeout" message. */
+ icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
}
+
+out_rcu_unlock:
+ rcu_read_unlock();
out:
spin_unlock(&qp->q.lock);
ipq_put(qp);