From 698e2a8dca98e4de32f3f630e6d9cd93753c52e1 Mon Sep 17 00:00:00 2001 From: Marco Angaroni Date: Tue, 26 Apr 2016 21:20:22 +0200 Subject: [PATCH] ipvs: make drop_entry protection effective for SIP-pe 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 Acked-by: Julian Anastasov Signed-off-by: Simon Horman --- 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 292365ffa4f0..2cb3c626cd43 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 f3bac2e9a25a..1207f20d24e4 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; } @@ -1991,6 +1994,9 @@ 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; -- 2.20.1