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Date: Thu, 25 Nov 2010 10:46:54 +0900
From: Simon Horman <horms@...ge.net.au>
To: lvs-devel@...r.kernel.org, netdev@...r.kernel.org,
netfilter@...r.kernel.org, netfilter-devel@...r.kernel.org
Cc: Hans Schillstrom <hans.schillstrom@...csson.com>,
Julian Anastasov <ja@....bg>,
Patrick McHardy <kaber@...sh.net>,
Simon Horman <horms@...ge.net.au>
Subject: [PATCH 4/8] IPVS: Handle Scheduling errors.
From: Hans Schillstrom <hans.schillstrom@...csson.com>
If ip_vs_conn_fill_param_persist return an error to ip_vs_sched_persist,
this error must propagate as ignored=-1 to ip_vs_schedule().
Errors from ip_vs_conn_new() in ip_vs_sched_persist() and ip_vs_schedule()
should also return *ignored=-1;
This patch just relies on the fact that ignored is 1 before calling
ip_vs_sched_persist().
Sent from Julian:
"The new case when ip_vs_conn_fill_param_persist fails
should set *ignored = -1, so that we can use NF_DROP,
see below. *ignored = -1 should be also used for ip_vs_conn_new
failure in ip_vs_sched_persist() and ip_vs_schedule().
The new negative value should be handled in tcp,udp,sctp"
"To summarize:
- *ignored = 1:
protocol tried to schedule (eg. on SYN), found svc but the
svc/scheduler decides that this packet should be accepted with
NF_ACCEPT because it must not be scheduled.
- *ignored = 0:
scheduler can not find destination, so try bypass or
return ICMP and then NF_DROP (ip_vs_leave).
- *ignored = -1:
scheduler tried to schedule but fatal error occurred, eg.
ip_vs_conn_new failure (ENOMEM) or ip_vs_sip_fill_param
failure such as missing Call-ID, ENOMEM on skb_linearize
or pe_data. In this case we should return NF_DROP without
any attempts to send ICMP with ip_vs_leave."
More or less all ideas and input to this patch is work from
Julian Anastasov
Signed-off-by: Hans Schillstrom <hans.schillstrom@...csson.com>
Acked-by: Julian Anastasov <ja@....bg>
Signed-off-by: Simon Horman <horms@...ge.net.au>
---
net/netfilter/ipvs/ip_vs_core.c | 56 +++++++++++++++++++++++---------
net/netfilter/ipvs/ip_vs_proto_sctp.c | 11 +++++--
net/netfilter/ipvs/ip_vs_proto_tcp.c | 10 +++++-
net/netfilter/ipvs/ip_vs_proto_udp.c | 10 +++++-
4 files changed, 64 insertions(+), 23 deletions(-)
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index 9acdd79..3445da6 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -177,7 +177,7 @@ ip_vs_set_state(struct ip_vs_conn *cp, int direction,
return pp->state_transition(cp, direction, skb, pp);
}
-static inline void
+static inline int
ip_vs_conn_fill_param_persist(const struct ip_vs_service *svc,
struct sk_buff *skb, int protocol,
const union nf_inet_addr *caddr, __be16 cport,
@@ -187,7 +187,9 @@ ip_vs_conn_fill_param_persist(const struct ip_vs_service *svc,
ip_vs_conn_fill_param(svc->af, protocol, caddr, cport, vaddr, vport, p);
p->pe = svc->pe;
if (p->pe && p->pe->fill_param)
- p->pe->fill_param(p, skb);
+ return p->pe->fill_param(p, skb);
+
+ return 0;
}
/*
@@ -200,7 +202,7 @@ ip_vs_conn_fill_param_persist(const struct ip_vs_service *svc,
static struct ip_vs_conn *
ip_vs_sched_persist(struct ip_vs_service *svc,
struct sk_buff *skb,
- __be16 src_port, __be16 dst_port)
+ __be16 src_port, __be16 dst_port, int *ignored)
{
struct ip_vs_conn *cp = NULL;
struct ip_vs_iphdr iph;
@@ -268,20 +270,27 @@ ip_vs_sched_persist(struct ip_vs_service *svc,
vaddr = &fwmark;
}
}
- ip_vs_conn_fill_param_persist(svc, skb, protocol, &snet, 0,
- vaddr, vport, ¶m);
+ /* return *ignored = -1 so NF_DROP can be used */
+ if (ip_vs_conn_fill_param_persist(svc, skb, protocol, &snet, 0,
+ vaddr, vport, ¶m) < 0) {
+ *ignored = -1;
+ return NULL;
+ }
}
/* Check if a template already exists */
ct = ip_vs_ct_in_get(¶m);
if (!ct || !ip_vs_check_template(ct)) {
- /* No template found or the dest of the connection
+ /*
+ * No template found or the dest of the connection
* template is not available.
+ * return *ignored=0 i.e. ICMP and NF_DROP
*/
dest = svc->scheduler->schedule(svc, skb);
if (!dest) {
IP_VS_DBG(1, "p-schedule: no dest found.\n");
kfree(param.pe_data);
+ *ignored = 0;
return NULL;
}
@@ -296,6 +305,7 @@ ip_vs_sched_persist(struct ip_vs_service *svc,
IP_VS_CONN_F_TEMPLATE, dest, skb->mark);
if (ct == NULL) {
kfree(param.pe_data);
+ *ignored = -1;
return NULL;
}
@@ -323,6 +333,7 @@ ip_vs_sched_persist(struct ip_vs_service *svc,
cp = ip_vs_conn_new(¶m, &dest->addr, dport, flags, dest, skb->mark);
if (cp == NULL) {
ip_vs_conn_put(ct);
+ *ignored = -1;
return NULL;
}
@@ -342,6 +353,21 @@ ip_vs_sched_persist(struct ip_vs_service *svc,
* It selects a server according to the virtual service, and
* creates a connection entry.
* Protocols supported: TCP, UDP
+ *
+ * Usage of *ignored
+ *
+ * 1 : protocol tried to schedule (eg. on SYN), found svc but the
+ * svc/scheduler decides that this packet should be accepted with
+ * NF_ACCEPT because it must not be scheduled.
+ *
+ * 0 : scheduler can not find destination, so try bypass or
+ * return ICMP and then NF_DROP (ip_vs_leave).
+ *
+ * -1 : scheduler tried to schedule but fatal error occurred, eg.
+ * ip_vs_conn_new failure (ENOMEM) or ip_vs_sip_fill_param
+ * failure such as missing Call-ID, ENOMEM on skb_linearize
+ * or pe_data. In this case we should return NF_DROP without
+ * any attempts to send ICMP with ip_vs_leave.
*/
struct ip_vs_conn *
ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
@@ -372,11 +398,9 @@ ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
}
/*
- * Do not schedule replies from local real server. It is risky
- * for fwmark services but mostly for persistent services.
+ * Do not schedule replies from local real server.
*/
if ((!skb->dev || skb->dev->flags & IFF_LOOPBACK) &&
- (svc->flags & IP_VS_SVC_F_PERSISTENT || svc->fwmark) &&
(cp = pp->conn_in_get(svc->af, skb, pp, &iph, iph.len, 1))) {
IP_VS_DBG_PKT(12, svc->af, pp, skb, 0,
"Not scheduling reply for existing connection");
@@ -387,10 +411,10 @@ ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
/*
* Persistent service
*/
- if (svc->flags & IP_VS_SVC_F_PERSISTENT) {
- *ignored = 0;
- return ip_vs_sched_persist(svc, skb, pptr[0], pptr[1]);
- }
+ if (svc->flags & IP_VS_SVC_F_PERSISTENT)
+ return ip_vs_sched_persist(svc, skb, pptr[0], pptr[1], ignored);
+
+ *ignored = 0;
/*
* Non-persistent service
@@ -403,8 +427,6 @@ ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
return NULL;
}
- *ignored = 0;
-
dest = svc->scheduler->schedule(svc, skb);
if (dest == NULL) {
IP_VS_DBG(1, "Schedule: no dest found.\n");
@@ -425,8 +447,10 @@ ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
cp = ip_vs_conn_new(&p, &dest->addr,
dest->port ? dest->port : pptr[1],
flags, dest, skb->mark);
- if (!cp)
+ if (!cp) {
+ *ignored = -1;
return NULL;
+ }
}
IP_VS_DBG_BUF(6, "Schedule fwd:%c c:%s:%u v:%s:%u "
diff --git a/net/netfilter/ipvs/ip_vs_proto_sctp.c b/net/netfilter/ipvs/ip_vs_proto_sctp.c
index 1ea96bc..a315159 100644
--- a/net/netfilter/ipvs/ip_vs_proto_sctp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_sctp.c
@@ -47,13 +47,18 @@ sctp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_protocol *pp,
* incoming connection, and create a connection entry.
*/
*cpp = ip_vs_schedule(svc, skb, pp, &ignored);
- if (!*cpp && !ignored) {
- *verdict = ip_vs_leave(svc, skb, pp);
+ if (!*cpp && ignored <= 0) {
+ if (!ignored)
+ *verdict = ip_vs_leave(svc, skb, pp);
+ else {
+ ip_vs_service_put(svc);
+ *verdict = NF_DROP;
+ }
return 0;
}
ip_vs_service_put(svc);
}
-
+ /* NF_ACCEPT */
return 1;
}
diff --git a/net/netfilter/ipvs/ip_vs_proto_tcp.c b/net/netfilter/ipvs/ip_vs_proto_tcp.c
index f6c5200..1cdab12 100644
--- a/net/netfilter/ipvs/ip_vs_proto_tcp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_tcp.c
@@ -64,12 +64,18 @@ tcp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_protocol *pp,
* incoming connection, and create a connection entry.
*/
*cpp = ip_vs_schedule(svc, skb, pp, &ignored);
- if (!*cpp && !ignored) {
- *verdict = ip_vs_leave(svc, skb, pp);
+ if (!*cpp && ignored <= 0) {
+ if (!ignored)
+ *verdict = ip_vs_leave(svc, skb, pp);
+ else {
+ ip_vs_service_put(svc);
+ *verdict = NF_DROP;
+ }
return 0;
}
ip_vs_service_put(svc);
}
+ /* NF_ACCEPT */
return 1;
}
diff --git a/net/netfilter/ipvs/ip_vs_proto_udp.c b/net/netfilter/ipvs/ip_vs_proto_udp.c
index 9d106a0..cd398de 100644
--- a/net/netfilter/ipvs/ip_vs_proto_udp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_udp.c
@@ -63,12 +63,18 @@ udp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_protocol *pp,
* incoming connection, and create a connection entry.
*/
*cpp = ip_vs_schedule(svc, skb, pp, &ignored);
- if (!*cpp && !ignored) {
- *verdict = ip_vs_leave(svc, skb, pp);
+ if (!*cpp && ignored <= 0) {
+ if (!ignored)
+ *verdict = ip_vs_leave(svc, skb, pp);
+ else {
+ ip_vs_service_put(svc);
+ *verdict = NF_DROP;
+ }
return 0;
}
ip_vs_service_put(svc);
}
+ /* NF_ACCEPT */
return 1;
}
--
1.7.2.3
--
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