[PATCH 0/2] Netfilter/IPVS fixes for net

[PATCH 0/2] Netfilter/IPVS fixes for net

[Pablo Neira Ayuso]

Hi David,

The following patchset contains two Netfilter/IPVS fixes for your net
tree, they are:

1) Fix missing alignment in next offset calculation for standard
   targets, introduced in the previous merge window, patch from
   Florian Westphal.

2) Fix to correct the handling of outgoing connections which use the
   SIP-pe such that the binding of a real-server is updated when needed.
   This was an omission from changes introduced by Marco Angaroni in
   the previous merge window too, to allow handling of outgoing
   connections by the SIP-pe. Patch and report came via Simon Horman.

You can pull these changes from:

  git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git

Thanks!

----------------------------------------------------------------

The following changes since commit 14b84e8654c89ed59f433654e6bb64c886d095cd:

  qed: fix qed_fill_link() error handling (2016-06-01 22:04:54 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git HEAD

for you to fetch changes up to 3ec10d3a2ba591c87da94219c1e46b02ae97757a:

  ipvs: update real-server binding of outgoing connections in SIP-pe (2016-06-06 09:47:25 +0900)

----------------------------------------------------------------
Florian Westphal (1):
      netfilter: x_tables: don't reject valid target size on some architectures

Marco Angaroni (1):
      ipvs: update real-server binding of outgoing connections in SIP-pe

 include/net/ip_vs.h             | 2 +-
 net/netfilter/ipvs/ip_vs_conn.c | 5 +++--
 net/netfilter/ipvs/ip_vs_core.c | 5 +++--
 net/netfilter/x_tables.c        | 4 ++--
 4 files changed, 9 insertions(+), 7 deletions(-)

[PATCH 1/2] netfilter: x_tables: don't reject valid target size on some architectures

[Pablo Neira Ayuso]

From: Florian Westphal <fw@strlen.de>

Quoting John Stultz:
  In updating a 32bit arm device from 4.6 to Linus' current HEAD, I
  noticed I was having some trouble with networking, and realized that
  /proc/net/ip_tables_names was suddenly empty.
  Digging through the registration process, it seems we're catching on the:

   if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0 &&
       target_offset + sizeof(struct xt_standard_target) != next_offset)
         return -EINVAL;

  Where next_offset seems to be 4 bytes larger then the
  offset + standard_target struct size.

next_offset needs to be aligned via XT_ALIGN (so we can access all members
of ip(6)t_entry struct).

This problem didn't show up on i686 as it only needs 4-byte alignment for
u64, but iptables userspace on other 32bit arches does insert extra padding.

Reported-by: John Stultz <john.stultz@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Fixes: 7ed2abddd20cf ("netfilter: x_tables: check standard target size too")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/x_tables.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index c69c892..2675d58 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -612,7 +612,7 @@ int xt_compat_check_entry_offsets(const void *base, const char *elems,
 		return -EINVAL;
 
 	if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0 &&
-	    target_offset + sizeof(struct compat_xt_standard_target) != next_offset)
+	    COMPAT_XT_ALIGN(target_offset + sizeof(struct compat_xt_standard_target)) != next_offset)
 		return -EINVAL;
 
 	/* compat_xt_entry match has less strict aligment requirements,
@@ -694,7 +694,7 @@ int xt_check_entry_offsets(const void *base,
 		return -EINVAL;
 
 	if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0 &&
-	    target_offset + sizeof(struct xt_standard_target) != next_offset)
+	    XT_ALIGN(target_offset + sizeof(struct xt_standard_target)) != next_offset)
 		return -EINVAL;
 
 	return xt_check_entry_match(elems, base + target_offset,
-- 
2.1.4

[PATCH 2/2] ipvs: update real-server binding of outgoing connections in SIP-pe

[Pablo Neira Ayuso]

From: Marco Angaroni <marcoangaroni@gmail.com>

Previous patch that introduced handling of outgoing packets in SIP
persistent-engine did not call ip_vs_check_template() in case packet was
matching a connection template. Assumption was that real-server was
healthy, since it was sending a packet just in that moment.

There are however real-server fault conditions requiring that association
between call-id and real-server (represented by connection template)
gets updated. Here is an example of the sequence of events:
  1) RS1 is a back2back user agent that handled call-id1 and call-id2
  2) RS1 is down and was marked as unavailable
  3) new message from outside comes to IPVS with call-id1
  4) IPVS reschedules the message to RS2, which becomes new call handler
  5) RS2 forwards the message outside, translating call-id1 to call-id2
  6) inside pe->conn_out() IPVS matches call-id2 with existing template
  7) IPVS does not change association call-id2 <-> RS1
  8) new message comes from client with call-id2
  9) IPVS reschedules the message to a real-server potentially different
     from RS2, which is now the correct destination

This patch introduces ip_vs_check_template() call in the handling of
outgoing packets for SIP-pe. And also introduces a second optional
argument for ip_vs_check_template() that allows to check if dest
associated to a connection template is the same dest that was identified
as the source of the packet. This is to change the real-server bound to a
particular call-id independently from its availability status: the idea
is that it's more reliable, for in->out direction (where internal
network can be considered trusted), to always associate a call-id with
the last real-server that used it in one of its messages. Think about
above sequence of events where, just after step 5, RS1 returns instead
to be available.

Comparison of dests is done by simply comparing pointers to struct
ip_vs_dest; there should be no cases where struct ip_vs_dest keeps its
memory address, but represent a different real-server in terms of
ip-address / port.

Fixes: 39b972231536 ("ipvs: handle connections started by real-servers")
Signed-off-by: Marco Angaroni <marcoangaroni@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
---
 include/net/ip_vs.h             | 2 +-
 net/netfilter/ipvs/ip_vs_conn.c | 5 +++--
 net/netfilter/ipvs/ip_vs_core.c | 5 +++--
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index af4c10e..cd6018a 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -1232,7 +1232,7 @@ void ip_vs_conn_expire_now(struct ip_vs_conn *cp);
 const char *ip_vs_state_name(__u16 proto, int state);
 
 void ip_vs_tcp_conn_listen(struct ip_vs_conn *cp);
-int ip_vs_check_template(struct ip_vs_conn *ct);
+int ip_vs_check_template(struct ip_vs_conn *ct, struct ip_vs_dest *cdest);
 void ip_vs_random_dropentry(struct netns_ipvs *ipvs);
 int ip_vs_conn_init(void);
 void ip_vs_conn_cleanup(void);
diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c
index 2cb3c62..096a451 100644
--- a/net/netfilter/ipvs/ip_vs_conn.c
+++ b/net/netfilter/ipvs/ip_vs_conn.c
@@ -762,7 +762,7 @@ static int expire_quiescent_template(struct netns_ipvs *ipvs,
  *	If available, return 1, otherwise invalidate this connection
  *	template and return 0.
  */
-int ip_vs_check_template(struct ip_vs_conn *ct)
+int ip_vs_check_template(struct ip_vs_conn *ct, struct ip_vs_dest *cdest)
 {
 	struct ip_vs_dest *dest = ct->dest;
 	struct netns_ipvs *ipvs = ct->ipvs;
@@ -772,7 +772,8 @@ int ip_vs_check_template(struct ip_vs_conn *ct)
 	 */
 	if ((dest == NULL) ||
 	    !(dest->flags & IP_VS_DEST_F_AVAILABLE) ||
-	    expire_quiescent_template(ipvs, dest)) {
+	    expire_quiescent_template(ipvs, dest) ||
+	    (cdest && (dest != cdest))) {
 		IP_VS_DBG_BUF(9, "check_template: dest not available for "
 			      "protocol %s s:%s:%d v:%s:%d "
 			      "-> d:%s:%d\n",
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index 1207f20..2c1b498 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -321,7 +321,7 @@ ip_vs_sched_persist(struct ip_vs_service *svc,
 
 	/* Check if a template already exists */
 	ct = ip_vs_ct_in_get(&param);
-	if (!ct || !ip_vs_check_template(ct)) {
+	if (!ct || !ip_vs_check_template(ct, NULL)) {
 		struct ip_vs_scheduler *sched;
 
 		/*
@@ -1154,7 +1154,8 @@ struct ip_vs_conn *ip_vs_new_conn_out(struct ip_vs_service *svc,
 						  vport, &param) < 0)
 			return NULL;
 		ct = ip_vs_ct_in_get(&param);
-		if (!ct) {
+		/* check if template exists and points to the same dest */
+		if (!ct || !ip_vs_check_template(ct, dest)) {
 			ct = ip_vs_conn_new(&param, dest->af, daddr, dport,
 					    IP_VS_CONN_F_TEMPLATE, dest, 0);
 			if (!ct) {
-- 
2.1.4

Re: [PATCH 0/2] Netfilter/IPVS fixes for net

[David Miller]

From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Tue,  7 Jun 2016 00:38:15 +0200

> The following patchset contains two Netfilter/IPVS fixes for your net
> tree, they are:
> 
> 1) Fix missing alignment in next offset calculation for standard
>    targets, introduced in the previous merge window, patch from
>    Florian Westphal.
> 
> 2) Fix to correct the handling of outgoing connections which use the
>    SIP-pe such that the binding of a real-server is updated when needed.
>    This was an omission from changes introduced by Marco Angaroni in
>    the previous merge window too, to allow handling of outgoing
>    connections by the SIP-pe. Patch and report came via Simon Horman.

Pulled, thanks Pablo.