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authorLorenzo Bianconi <lorenzo.bianconi@redhat.com>2019-02-06 19:18:04 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-02-23 09:05:59 +0100
commit575880f2d42b7c16669f0fc9ca4ae6ed718d4b90 (patch)
tree02e018a4764cd6104931b18b42769198b841839a /net
parent2a3c68987c698bf0a12e34fa0e76674ed8cc91c9 (diff)
net: ipv4: use a dedicated counter for icmp_v4 redirect packets
[ Upstream commit c09551c6ff7fe16a79a42133bcecba5fc2fc3291 ] According to the algorithm described in the comment block at the beginning of ip_rt_send_redirect, the host should try to send 'ip_rt_redirect_number' ICMP redirect packets with an exponential backoff and then stop sending them at all assuming that the destination ignores redirects. If the device has previously sent some ICMP error packets that are rate-limited (e.g TTL expired) and continues to receive traffic, the redirect packets will never be transmitted. This happens since peer->rate_tokens will be typically greater than 'ip_rt_redirect_number' and so it will never be reset even if the redirect silence timeout (ip_rt_redirect_silence) has elapsed without receiving any packet requiring redirects. Fix it by using a dedicated counter for the number of ICMP redirect packets that has been sent by the host I have not been able to identify a given commit that introduced the issue since ip_rt_send_redirect implements the same rate-limiting algorithm from commit 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/inetpeer.c1
-rw-r--r--net/ipv4/route.c7
2 files changed, 6 insertions, 2 deletions
diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c
index 86fa45809540..0c5862914f05 100644
--- a/net/ipv4/inetpeer.c
+++ b/net/ipv4/inetpeer.c
@@ -448,6 +448,7 @@ relookup:
atomic_set(&p->rid, 0);
p->metrics[RTAX_LOCK-1] = INETPEER_METRICS_NEW;
p->rate_tokens = 0;
+ p->n_redirects = 0;
/* 60*HZ is arbitrary, but chosen enough high so that the first
* calculation of tokens is at its maximum.
*/
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 890141d32ab9..d606de65e2d0 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -882,13 +882,15 @@ void ip_rt_send_redirect(struct sk_buff *skb)
/* No redirected packets during ip_rt_redirect_silence;
* reset the algorithm.
*/
- if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
+ if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) {
peer->rate_tokens = 0;
+ peer->n_redirects = 0;
+ }
/* Too many ignored redirects; do not send anything
* set dst.rate_last to the last seen redirected packet.
*/
- if (peer->rate_tokens >= ip_rt_redirect_number) {
+ if (peer->n_redirects >= ip_rt_redirect_number) {
peer->rate_last = jiffies;
goto out_put_peer;
}
@@ -905,6 +907,7 @@ void ip_rt_send_redirect(struct sk_buff *skb)
icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
peer->rate_last = jiffies;
++peer->rate_tokens;
+ ++peer->n_redirects;
#ifdef CONFIG_IP_ROUTE_VERBOSE
if (log_martians &&
peer->rate_tokens == ip_rt_redirect_number)