[PATCH 1/2] netfilter: ipvs: avoid unused variable warnings

The proc_create() and remove_proc_entry() functions do not reference
their arguments when CONFIG_PROC_FS is disabled, so we get a couple
of warnings about unused variables in IPVS:

ipvs/ip_vs_app.c:608:14: warning: unused variable 'net' [-Wunused-variable]
ipvs/ip_vs_ctl.c:3950:14: warning: unused variable 'net' [-Wunused-variable]
ipvs/ip_vs_ctl.c:3994:14: warning: unused variable 'net' [-Wunused-variable]

This removes the local variables and instead looks them up separately
for each use, which obviously avoids the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 4c50a8ce2b63 ("netfilter: ipvs: avoid unused variable warning")
---
 net/netfilter/ipvs/ip_vs_app.c |  8 ++------
 net/netfilter/ipvs/ip_vs_ctl.c | 15 ++++++---------
 2 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_app.c b/net/netfilter/ipvs/ip_vs_app.c
index 0328f7250693..299edc6add5a 100644
--- a/net/netfilter/ipvs/ip_vs_app.c
+++ b/net/netfilter/ipvs/ip_vs_app.c

@@ -605,17 +605,13 @@ static const struct file_operations ip_vs_app_fops = {
 
 int __net_init ip_vs_app_net_init(struct netns_ipvs *ipvs)
 {
-	struct net *net = ipvs->net;
-
 	INIT_LIST_HEAD(&ipvs->app_list);
-	proc_create("ip_vs_app", 0, net->proc_net, &ip_vs_app_fops);
+	proc_create("ip_vs_app", 0, ipvs->net->proc_net, &ip_vs_app_fops);
 	return 0;
 }
 
 void __net_exit ip_vs_app_net_cleanup(struct netns_ipvs *ipvs)
 {
-	struct net *net = ipvs->net;
-
 	unregister_ip_vs_app(ipvs, NULL /* all */);
-	remove_proc_entry("ip_vs_app", net->proc_net);
+	remove_proc_entry("ip_vs_app", ipvs->net->proc_net);
 }

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index e7c1b052c2a3..bfb4f8372b83 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c

@@ -3947,7 +3947,6 @@ static struct notifier_block ip_vs_dst_notifier = {
 
 int __net_init ip_vs_control_net_init(struct netns_ipvs *ipvs)
 {
-	struct net *net = ipvs->net;
 	int i, idx;
 
 	/* Initialize rs_table */

@@ -3974,9 +3973,9 @@ int __net_init ip_vs_control_net_init(struct netns_ipvs *ipvs)
 
 	spin_lock_init(&ipvs->tot_stats.lock);
 
-	proc_create("ip_vs", 0, net->proc_net, &ip_vs_info_fops);
-	proc_create("ip_vs_stats", 0, net->proc_net, &ip_vs_stats_fops);
-	proc_create("ip_vs_stats_percpu", 0, net->proc_net,
+	proc_create("ip_vs", 0, ipvs->net->proc_net, &ip_vs_info_fops);
+	proc_create("ip_vs_stats", 0, ipvs->net->proc_net, &ip_vs_stats_fops);
+	proc_create("ip_vs_stats_percpu", 0, ipvs->net->proc_net,
 		    &ip_vs_stats_percpu_fops);
 
 	if (ip_vs_control_net_init_sysctl(ipvs))

@@ -3991,13 +3990,11 @@ err:
 
 void __net_exit ip_vs_control_net_cleanup(struct netns_ipvs *ipvs)
 {
-	struct net *net = ipvs->net;
-
 	ip_vs_trash_cleanup(ipvs);
 	ip_vs_control_net_cleanup_sysctl(ipvs);
-	remove_proc_entry("ip_vs_stats_percpu", net->proc_net);
-	remove_proc_entry("ip_vs_stats", net->proc_net);
-	remove_proc_entry("ip_vs", net->proc_net);
+	remove_proc_entry("ip_vs_stats_percpu", ipvs->net->proc_net);
+	remove_proc_entry("ip_vs_stats", ipvs->net->proc_net);
+	remove_proc_entry("ip_vs", ipvs->net->proc_net);
 	free_percpu(ipvs->tot_stats.cpustats);
 }
 

-- 
2.7.0

ip_vs_fill_iph_skb_off() may not find an IP header, and gcc has
determined that ip_vs_sip_fill_param() then incorrectly accesses
the protocol fields:

net/netfilter/ipvs/ip_vs_pe_sip.c: In function 'ip_vs_sip_fill_param':
net/netfilter/ipvs/ip_vs_pe_sip.c:76:5: error: 'iph.protocol' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  if (iph.protocol != IPPROTO_UDP)
     ^
net/netfilter/ipvs/ip_vs_pe_sip.c:81:10: error: 'iph.len' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  dataoff = iph.len + sizeof(struct udphdr);
          ^

This adds a check for the ip_vs_fill_iph_skb_off() return code
before looking at the ip header data returned from it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: b0e010c527de ("ipvs: replace ip_vs_fill_ip4hdr with ip_vs_fill_iph_skb_off")
---
 net/netfilter/ipvs/ip_vs_pe_sip.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_pe_sip.c b/net/netfilter/ipvs/ip_vs_pe_sip.c
index 1b8d594e493a..c4e9ca016a88 100644
--- a/net/netfilter/ipvs/ip_vs_pe_sip.c
+++ b/net/netfilter/ipvs/ip_vs_pe_sip.c

@@ -70,10 +70,10 @@ ip_vs_sip_fill_param(struct ip_vs_conn_param *p, struct sk_buff *skb)
 	const char *dptr;
 	int retc;
 
-	ip_vs_fill_iph_skb(p->af, skb, false, &iph);
+	retc = ip_vs_fill_iph_skb(p->af, skb, false, &iph);
 
 	/* Only useful with UDP */
-	if (iph.protocol != IPPROTO_UDP)
+	if (!retc || iph.protocol != IPPROTO_UDP)
 		return -EINVAL;
 	/* todo: IPv6 fragments:
 	 *       I think this only should be done for the first fragment. /HS

-- 
2.7.0

	Hello,

On Wed, 27 Jan 2016, Arnd Bergmann wrote:

The proc_create() and remove_proc_entry() functions do not reference
their arguments when CONFIG_PROC_FS is disabled, so we get a couple
of warnings about unused variables in IPVS:

ipvs/ip_vs_app.c:608:14: warning: unused variable 'net' [-Wunused-variable]
ipvs/ip_vs_ctl.c:3950:14: warning: unused variable 'net' [-Wunused-variable]
ipvs/ip_vs_ctl.c:3994:14: warning: unused variable 'net' [-Wunused-variable]

This removes the local variables and instead looks them up separately
for each use, which obviously avoids the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 4c50a8ce2b63 ("netfilter: ipvs: avoid unused variable warning")

	Looks like your previous patch for ip_vs_app_net_cleanup
was delayed in ipvs-next tree. I guess, Simon should drop it and
use this one instead when net-next opens:

Acked-by: Julian Anastasov <ja@ssi.bg>

Regards

--
Julian Anastasov [off-list ref]

	Hello,

On Wed, 27 Jan 2016, Arnd Bergmann wrote:

ip_vs_fill_iph_skb_off() may not find an IP header, and gcc has
determined that ip_vs_sip_fill_param() then incorrectly accesses
the protocol fields:

net/netfilter/ipvs/ip_vs_pe_sip.c: In function 'ip_vs_sip_fill_param':
net/netfilter/ipvs/ip_vs_pe_sip.c:76:5: error: 'iph.protocol' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  if (iph.protocol != IPPROTO_UDP)
     ^
net/netfilter/ipvs/ip_vs_pe_sip.c:81:10: error: 'iph.len' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  dataoff = iph.len + sizeof(struct udphdr);
          ^

This adds a check for the ip_vs_fill_iph_skb_off() return code
before looking at the ip header data returned from it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: b0e010c527de ("ipvs: replace ip_vs_fill_ip4hdr with ip_vs_fill_iph_skb_off")

	Looks ok to me,

Acked-by: Julian Anastasov <ja@ssi.bg>

	but see below...

	There are other places like this where result is not
checked because there is always a guarding skb_header_pointer
check, i.e. ip_vs_fill_iph_skb* should not fail at such point.

	Let us know you want to extend this patch with other such
calls (including ip_vs_fill_iph_skb_icmp)? May be they will
need return NF_ACCEPT. I guess, all such changes should be
for the ipvs-next/net-next tree when it opens.

Regards

--
Julian Anastasov [off-list ref]

On Wed, Jan 27, 2016 at 10:56:08PM +0200, Julian Anastasov wrote:

	Hello,

On Wed, 27 Jan 2016, Arnd Bergmann wrote:

quoted

ip_vs_fill_iph_skb_off() may not find an IP header, and gcc has
determined that ip_vs_sip_fill_param() then incorrectly accesses
the protocol fields:

net/netfilter/ipvs/ip_vs_pe_sip.c: In function 'ip_vs_sip_fill_param':
net/netfilter/ipvs/ip_vs_pe_sip.c:76:5: error: 'iph.protocol' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  if (iph.protocol != IPPROTO_UDP)
     ^
net/netfilter/ipvs/ip_vs_pe_sip.c:81:10: error: 'iph.len' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  dataoff = iph.len + sizeof(struct udphdr);
          ^

This adds a check for the ip_vs_fill_iph_skb_off() return code
before looking at the ip header data returned from it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: b0e010c527de ("ipvs: replace ip_vs_fill_ip4hdr with ip_vs_fill_iph_skb_off")

	Looks ok to me,

Acked-by: Julian Anastasov <ja@ssi.bg>

Thanks, I have queued this up.

	but see below...

quoted

---
 net/netfilter/ipvs/ip_vs_pe_sip.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_pe_sip.c b/net/netfilter/ipvs/ip_vs_pe_sip.c
index 1b8d594e493a..c4e9ca016a88 100644
--- a/net/netfilter/ipvs/ip_vs_pe_sip.c
+++ b/net/netfilter/ipvs/ip_vs_pe_sip.c

@@ -70,10 +70,10 @@ ip_vs_sip_fill_param(struct ip_vs_conn_param *p, struct sk_buff *skb)
 	const char *dptr;
 	int retc;
 
-	ip_vs_fill_iph_skb(p->af, skb, false, &iph);
+	retc = ip_vs_fill_iph_skb(p->af, skb, false, &iph);
 
 	/* Only useful with UDP */
-	if (iph.protocol != IPPROTO_UDP)
+	if (!retc || iph.protocol != IPPROTO_UDP)
 		return -EINVAL;
 	/* todo: IPv6 fragments:
 	 *       I think this only should be done for the first fragment. /HS

	There are other places like this where result is not
checked because there is always a guarding skb_header_pointer
check, i.e. ip_vs_fill_iph_skb* should not fail at such point.

	Let us know you want to extend this patch with other such
calls (including ip_vs_fill_iph_skb_icmp)? May be they will
need return NF_ACCEPT. I guess, all such changes should be
for the ipvs-next/net-next tree when it opens.

I would suggest making such changes incrementally on top of this one.

On Wed, Jan 27, 2016 at 10:01:42PM +0200, Julian Anastasov wrote:

	Hello,

On Wed, 27 Jan 2016, Arnd Bergmann wrote:

quoted

The proc_create() and remove_proc_entry() functions do not reference
their arguments when CONFIG_PROC_FS is disabled, so we get a couple
of warnings about unused variables in IPVS:

ipvs/ip_vs_app.c:608:14: warning: unused variable 'net' [-Wunused-variable]
ipvs/ip_vs_ctl.c:3950:14: warning: unused variable 'net' [-Wunused-variable]
ipvs/ip_vs_ctl.c:3994:14: warning: unused variable 'net' [-Wunused-variable]

This removes the local variables and instead looks them up separately
for each use, which obviously avoids the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 4c50a8ce2b63 ("netfilter: ipvs: avoid unused variable warning")

	Looks like your previous patch for ip_vs_app_net_cleanup
was delayed in ipvs-next tree. I guess, Simon should drop it and
use this one instead when net-next opens:

Acked-by: Julian Anastasov <ja@ssi.bg>

Thanks, and sorry about not pushing the other patch to net-next.
I have dropped it and queued up this one in its place.

On Thursday 28 January 2016 08:39:53 Simon Horman wrote:

On Wed, Jan 27, 2016 at 10:01:42PM +0200, Julian Anastasov wrote:

quoted

      Hello,

On Wed, 27 Jan 2016, Arnd Bergmann wrote:

quoted

The proc_create() and remove_proc_entry() functions do not reference
their arguments when CONFIG_PROC_FS is disabled, so we get a couple
of warnings about unused variables in IPVS:

ipvs/ip_vs_app.c:608:14: warning: unused variable 'net' [-Wunused-variable]
ipvs/ip_vs_ctl.c:3950:14: warning: unused variable 'net' [-Wunused-variable]
ipvs/ip_vs_ctl.c:3994:14: warning: unused variable 'net' [-Wunused-variable]

This removes the local variables and instead looks them up separately
for each use, which obviously avoids the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 4c50a8ce2b63 ("netfilter: ipvs: avoid unused variable warning")

      Looks like your previous patch for ip_vs_app_net_cleanup
was delayed in ipvs-next tree. I guess, Simon should drop it and
use this one instead when net-next opens:

Acked-by: Julian Anastasov <ja@ssi.bg>

Thanks, and sorry about not pushing the other patch to net-next.
I have dropped it and queued up this one in its place.

Ah, I had not realized that the other patch was still in ipvs-next
and not merged in mainline. I did most of my testing on linux-next
(with the previous patch) and then validated the new one on
4.5-rc1, which led me to update it to contain the same hunk again.

Replacing the original patch works fine though, thanks for picking
it up!

	Arnd