diff options
| -rw-r--r-- | net/ipv4/ip_fragment.c | 34 |
1 files changed, 30 insertions, 4 deletions
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index 891c72a..9f41bd3 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); |