DoS protection policy that deletes connections to avoid out of memory is
currently not effective for SIP-pe plus OPS-mode for two reasons:
1) connection templates (holding SIP call-id) are always skipped in
ip_vs_random_dropentry()
2) in_pkts counter (used by drop_entry algorithm) is not incremented
for connection templates
This patch addresses such problems with the following changes:
a) connection templates associated (via their dest) to virtual-services
configured in OPS mode are included in ip_vs_random_dropentry()
monitoring. This applies to SIP-pe over UDP (which requires OPS mode),
but is more general principle: when OPS is controlled by templates
memory can be used only by templates themselves, since OPS conns are
deleted after packet is forwarded.
b) OPS connections, if controlled by a template, cause increment of
in_pkts counter of their template. This is already happening but only
in case director is in master-slave mode (see ip_vs_sync_conn()).
Signed-off-by: Marco Angaroni <marcoangaroni@xxxxxxxxx>
---
net/netfilter/ipvs/ip_vs_conn.c | 22 +++++++++++++++++++---
net/netfilter/ipvs/ip_vs_core.c | 8 +++++++-
2 files changed, 26 insertions(+), 4 deletions(-)
diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c
index 292365f..2cb3c62 100644
--- a/net/netfilter/ipvs/ip_vs_conn.c
+++ b/net/netfilter/ipvs/ip_vs_conn.c
@@ -1261,6 +1261,16 @@ static inline int todrop_entry(struct ip_vs_conn *cp)
return 1;
}
+static inline bool ip_vs_conn_ops_mode(struct ip_vs_conn *cp)
+{
+ struct ip_vs_service *svc;
+
+ if (!cp->dest)
+ return false;
+ svc = rcu_dereference(cp->dest->svc);
+ return svc && (svc->flags & IP_VS_SVC_F_ONEPACKET);
+}
+
/* Called from keventd and must protect itself from softirqs */
void ip_vs_random_dropentry(struct netns_ipvs *ipvs)
{
@@ -1275,11 +1285,16 @@ void ip_vs_random_dropentry(struct netns_ipvs *ipvs)
unsigned int hash = prandom_u32() & ip_vs_conn_tab_mask;
hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
- if (cp->flags & IP_VS_CONN_F_TEMPLATE)
- /* connection template */
- continue;
if (cp->ipvs != ipvs)
continue;
+ if (cp->flags & IP_VS_CONN_F_TEMPLATE) {
+ if (atomic_read(&cp->n_control) ||
+ !ip_vs_conn_ops_mode(cp))
+ continue;
+ else
+ /* connection template of OPS */
+ goto try_drop;
+ }
if (cp->protocol == IPPROTO_TCP) {
switch(cp->state) {
case IP_VS_TCP_S_SYN_RECV:
@@ -1307,6 +1322,7 @@ void ip_vs_random_dropentry(struct netns_ipvs *ipvs)
continue;
}
} else {
+try_drop:
if (!todrop_entry(cp))
continue;
}
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index 398ccb5..a97de51 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -612,7 +612,10 @@ int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
ret = cp->packet_xmit(skb, cp, pd->pp, iph);
/* do not touch skb anymore */
- atomic_inc(&cp->in_pkts);
+ if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) && cp->control)
+ atomic_inc(&cp->control->in_pkts);
+ else
+ atomic_inc(&cp->in_pkts);
ip_vs_conn_put(cp);
return ret;
}
@@ -1971,6 +1974,9 @@ ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int
if (ipvs->sync_state & IP_VS_STATE_MASTER)
ip_vs_sync_conn(ipvs, cp, pkts);
+ else if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) && cp->control)
+ /* increment is done inside ip_vs_sync_conn too */
+ atomic_inc(&cp->control->in_pkts);
ip_vs_conn_put(cp);
return ret;
--
1.8.3.1
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