This set contains a set of small improvements found in IPv4 code during
preparations to support ARP in the network namespace. These fixes are
mostly independent except 2 last ones.

Signed-off-by: Denis V. Lunev <den@openvz.org>

The neighbour entry will be destroyed in the case of error, so it is pointless
to perform constly routing table lookup in this case.

Signed-off-by: Denis V. Lunev <den@openvz.org>
---
 net/ipv4/arp.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index b715ec0..49c24ff 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -235,8 +235,6 @@ static int arp_constructor(struct neighbour *neigh)
 	struct in_device *in_dev;
 	struct neigh_parms *parms;
 
-	neigh->type = inet_addr_type(&init_net, addr);
-
 	rcu_read_lock();
 	in_dev = __in_dev_get_rcu(dev);
 	if (in_dev == NULL) {
@@ -244,6 +242,8 @@ static int arp_constructor(struct neighbour *neigh)
 		return -EINVAL;
 	}
 
+	neigh->type = inet_addr_type(&init_net, addr);
+
 	parms = in_dev->arp_parms;
 	__neigh_parms_put(neigh->parms);
 	neigh->parms = neigh_parms_clone(parms);
-- 
1.5.3.rc5

Some calls in the arp.c have network namespace as an argument. Getting
init_net inside these functions is simply inconsistent. Fix this.

Signed-off-by: Denis V. Lunev <den@openvz.org>
---
 net/ipv4/arp.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 49c24ff..0db7d49 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -969,13 +969,13 @@ static int arp_req_set_public(struct net *net, struct arpreq *r,
 	if (mask && mask != htonl(0xFFFFFFFF))
 		return -EINVAL;
 	if (!dev && (r->arp_flags & ATF_COM)) {
-		dev = dev_getbyhwaddr(&init_net, r->arp_ha.sa_family,
+		dev = dev_getbyhwaddr(net, r->arp_ha.sa_family,
 				r->arp_ha.sa_data);
 		if (!dev)
 			return -ENODEV;
 	}
 	if (mask) {
-		if (pneigh_lookup(&arp_tbl, &init_net, &ip, dev, 1) == NULL)
+		if (pneigh_lookup(&arp_tbl, net, &ip, dev, 1) == NULL)
 			return -ENOBUFS;
 		return 0;
 	}
@@ -1084,7 +1084,7 @@ static int arp_req_delete_public(struct net *net, struct arpreq *r,
 	__be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
 
 	if (mask == htonl(0xFFFFFFFF))
-		return pneigh_delete(&arp_tbl, &init_net, &ip, dev);
+		return pneigh_delete(&arp_tbl, net, &ip, dev);
 
 	if (mask)
 		return -EINVAL;
@@ -1162,7 +1162,7 @@ int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 	rtnl_lock();
 	if (r.arp_dev[0]) {
 		err = -ENODEV;
-		if ((dev = __dev_get_by_name(&init_net, r.arp_dev)) == NULL)
+		if ((dev = __dev_get_by_name(net, r.arp_dev)) == NULL)
 			goto out;
 
 		/* Mmmm... It is wrong... ARPHRD_NETROM==0 */
-- 
1.5.3.rc5

No need for this. It is declared in the neighbour.h

Signed-off-by: Denis V. Lunev <den@openvz.org>
---
 net/core/neighbour.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 2eab6a5..9b0b773 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -59,7 +59,6 @@ static void neigh_timer_handler(unsigned long arg);
 static void __neigh_notify(struct neighbour *n, int type, int flags);
 static void neigh_update_notify(struct neighbour *neigh);
 static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
-void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
 
 static struct neigh_table *neigh_tables;
 #ifdef CONFIG_PROC_FS
-- 
1.5.3.rc5

inet_confirm_addr can be called with NULL in_dev from arp_ignore iff
scope is RT_SCOPE_LINK.

Lets always pass the device and check for RT_SCOPE_LINK scope inside
inet_confirm_addr. This let us take network namespace from in_device a
need for an additional argument.

Signed-off-by: Denis V. Lunev <den@openvz.org>
---
 net/ipv4/arp.c     |    1 -
 net/ipv4/devinet.c |    6 ++++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index f38e1a9..b715ec0 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -402,7 +400,6 @@ static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip)
 	case 3:	/* Do not reply for scope host addresses */
 		sip = 0;
 		scope = RT_SCOPE_LINK;
-		in_dev = NULL;
 		break;
 	case 4:	/* Reserved */
 	case 5:
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index dc1665a..4569c69 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -978,13 +978,15 @@ __be32 inet_confirm_addr(struct in_device *in_dev,
 {
 	__be32 addr = 0;
 	struct net_device *dev;
+	struct net *net;
 
-	if (in_dev != NULL)
+	if (scope != RT_SCOPE_LINK)
 		return confirm_addr_indev(in_dev, dst, local, scope);
 
+	net = in_dev->dev->nd_net;
 	read_lock(&dev_base_lock);
 	rcu_read_lock();
-	for_each_netdev(&init_net, dev) {
+	for_each_netdev(net, dev) {
 		if ((in_dev = __in_dev_get_rcu(dev))) {
 			addr = confirm_addr_indev(in_dev, dst, local, scope);
 			if (addr)
-- 
1.5.3.rc5

fib_rules_unregister is called only after successful register and the return
code is never checked.

Signed-off-by: Denis V. Lunev <den@openvz.org>
---
 include/net/fib_rules.h |    2 +-
 net/core/fib_rules.c    |   21 ++++-----------------
 2 files changed, 5 insertions(+), 18 deletions(-)

diff --git a/include/net/fib_rules.h b/include/net/fib_rules.h
index 88f870f..34349f9 100644
--- a/include/net/fib_rules.h
+++ b/include/net/fib_rules.h
@@ -104,7 +104,7 @@ static inline u32 frh_get_table(struct fib_rule_hdr *frh, struct nlattr **nla)
 }
 
 extern int fib_rules_register(struct net *, struct fib_rules_ops *);
-extern int fib_rules_unregister(struct net *, struct fib_rules_ops *);
+extern void fib_rules_unregister(struct net *, struct fib_rules_ops *);
 extern void                     fib_rules_cleanup_ops(struct fib_rules_ops *);
 
 extern int			fib_rules_lookup(struct fib_rules_ops *,
diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 0eecf4c..42ccaf5 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -115,29 +115,16 @@ void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
 }
 EXPORT_SYMBOL_GPL(fib_rules_cleanup_ops);
 
-int fib_rules_unregister(struct net *net, struct fib_rules_ops *ops)
+void fib_rules_unregister(struct net *net, struct fib_rules_ops *ops)
 {
-	int err = 0;
-	struct fib_rules_ops *o;
 
 	spin_lock(&net->rules_mod_lock);
-	list_for_each_entry(o, &net->rules_ops, list) {
-		if (o == ops) {
-			list_del_rcu(&o->list);
-			fib_rules_cleanup_ops(ops);
-			goto out;
-		}
-	}
-
-	err = -ENOENT;
-out:
+	list_del_rcu(&ops->list);
+	fib_rules_cleanup_ops(ops);
 	spin_unlock(&net->rules_mod_lock);
 
 	synchronize_rcu();
-	if (!err)
-		release_net(net);
-
-	return err;
+	release_net(net);
 }
 
 EXPORT_SYMBOL_GPL(fib_rules_unregister);
-- 
1.5.3.rc5

Make them static.

Signed-off-by: Denis V. Lunev <den@openvz.org>
---
 include/net/neighbour.h |    7 -------
 net/core/neighbour.c    |   11 ++++++++++-
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index a0d42a5..ebbfb50 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -213,7 +213,6 @@ extern struct neighbour 	*neigh_event_ns(struct neigh_table *tbl,
 
 extern struct neigh_parms	*neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
 extern void			neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
-extern void			neigh_parms_destroy(struct neigh_parms *parms);
 extern unsigned long		neigh_rand_reach_time(unsigned long base);
 
 extern void			pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
@@ -254,12 +253,6 @@ static inline void __neigh_parms_put(struct neigh_parms *parms)
 	atomic_dec(&parms->refcnt);
 }
 
-static inline void neigh_parms_put(struct neigh_parms *parms)
-{
-	if (atomic_dec_and_test(&parms->refcnt))
-		neigh_parms_destroy(parms);
-}
-
 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
 {
 	atomic_inc(&parms->refcnt);
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 9b0b773..41394db 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -55,6 +55,8 @@
 
 #define PNEIGH_HASHMASK		0xF
 
+static inline void neigh_parms_put(struct neigh_parms *parms);
+
 static void neigh_timer_handler(unsigned long arg);
 static void __neigh_notify(struct neighbour *n, int type, int flags);
 static void neigh_update_notify(struct neighbour *neigh);
@@ -1348,7 +1350,7 @@ void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms)
 	NEIGH_PRINTK1("neigh_parms_release: not found\n");
 }
 
-void neigh_parms_destroy(struct neigh_parms *parms)
+static void neigh_parms_destroy(struct neigh_parms *parms)
 {
 	release_net(parms->net);
 	if (parms->dev)
@@ -1356,6 +1358,13 @@ void neigh_parms_destroy(struct neigh_parms *parms)
 	kfree(parms);
 }
 
+static inline void neigh_parms_put(struct neigh_parms *parms)
+{
+	if (atomic_dec_and_test(&parms->refcnt))
+		neigh_parms_destroy(parms);
+}
+
+
 static struct lock_class_key neigh_table_proxy_queue_class;
 
 void neigh_table_init_no_netlink(struct neigh_table *tbl)
-- 
1.5.3.rc5

Valid network device is always passed into neigh_param_alloc, so remove
extra checking for dev == NULL. Additionally, cleanup bogus netns assignment.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
---
 net/core/neighbour.c |   18 +++++++-----------
 1 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index af49137..32f1a23 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1301,10 +1301,7 @@ struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
 	struct neigh_parms *p, *ref;
 	struct net *net;
 
-	net = &init_net;
-	if (dev)
-		net = dev->nd_net;
-
+	net = dev->nd_net;
 	ref = lookup_neigh_params(tbl, net, 0);
 	if (!ref)
 		return NULL;
@@ -1316,15 +1313,14 @@ struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
 		INIT_RCU_HEAD(&p->rcu_head);
 		p->reachable_time =
 				neigh_rand_reach_time(p->base_reachable_time);
-		if (dev) {
-			if (dev->neigh_setup && dev->neigh_setup(dev, p)) {
-				kfree(p);
-				return NULL;
-			}
 
-			dev_hold(dev);
-			p->dev = dev;
+		if (dev->neigh_setup && dev->neigh_setup(dev, p)) {
+			kfree(p);
+			return NULL;
 		}
+
+		dev_hold(dev);
+		p->dev = dev;
 		p->net = hold_net(net);
 		p->sysctl_table = NULL;
 		write_lock_bh(&tbl->lock);
-- 
1.5.3.rc5

arp_ignore has two arguments: dev & in_dev. dev is used for inet_confirm_addr
calling only.

inet_confirm_addr, in turn, either gets in_dev from the device passed or
iterates over all network devices if the device passed is NULL. It seems
logical to directly pass in_dev into inet_confirm_addr.

Signed-off-by: Denis V. Lunev <den@openvz.org>
---
 include/linux/inetdevice.h |    2 +-
 net/ipv4/arp.c             |   11 +++++------
 net/ipv4/devinet.c         |   17 ++++++-----------
 3 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index b3c5081..45f3731 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -135,7 +135,7 @@ extern int		devinet_ioctl(unsigned int cmd, void __user *);
 extern void		devinet_init(void);
 extern struct in_device	*inetdev_by_index(int);
 extern __be32		inet_select_addr(const struct net_device *dev, __be32 dst, int scope);
-extern __be32		inet_confirm_addr(const struct net_device *dev, __be32 dst, __be32 local, int scope);
+extern __be32		inet_confirm_addr(struct in_device *in_dev, __be32 dst, __be32 local, int scope);
 extern struct in_ifaddr *inet_ifa_byprefix(struct in_device *in_dev, __be32 prefix, __be32 mask);
 
 static __inline__ int inet_ifa_match(__be32 addr, struct in_ifaddr *ifa)
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index e944d98..f38e1a9 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -382,8 +382,7 @@ static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
 		read_unlock_bh(&neigh->lock);
 }
 
-static int arp_ignore(struct in_device *in_dev, struct net_device *dev,
-		      __be32 sip, __be32 tip)
+static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip)
 {
 	int scope;
 
@@ -403,7 +402,7 @@ static int arp_ignore(struct in_device *in_dev, struct net_device *dev,
 	case 3:	/* Do not reply for scope host addresses */
 		sip = 0;
 		scope = RT_SCOPE_LINK;
-		dev = NULL;
+		in_dev = NULL;
 		break;
 	case 4:	/* Reserved */
 	case 5:
@@ -415,7 +414,7 @@ static int arp_ignore(struct in_device *in_dev, struct net_device *dev,
 	default:
 		return 0;
 	}
-	return !inet_confirm_addr(dev, sip, tip, scope);
+	return !inet_confirm_addr(in_dev, sip, tip, scope);
 }
 
 static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev)
@@ -807,7 +806,7 @@ static int arp_process(struct sk_buff *skb)
 	if (sip == 0) {
 		if (arp->ar_op == htons(ARPOP_REQUEST) &&
 		    inet_addr_type(&init_net, tip) == RTN_LOCAL &&
-		    !arp_ignore(in_dev,dev,sip,tip))
+		    !arp_ignore(in_dev, sip, tip))
 			arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha,
 				 dev->dev_addr, sha);
 		goto out;
@@ -825,7 +824,7 @@ static int arp_process(struct sk_buff *skb)
 				int dont_send = 0;
 
 				if (!dont_send)
-					dont_send |= arp_ignore(in_dev,dev,sip,tip);
+					dont_send |= arp_ignore(in_dev,sip,tip);
 				if (!dont_send && IN_DEV_ARPFILTER(in_dev))
 					dont_send |= arp_filter(sip,tip,dev);
 				if (!dont_send)
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 03db15b..dc1665a 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -968,24 +968,19 @@ static __be32 confirm_addr_indev(struct in_device *in_dev, __be32 dst,
 
 /*
  * Confirm that local IP address exists using wildcards:
- * - dev: only on this interface, 0=any interface
+ * - in_dev: only on this interface, 0=any interface
  * - dst: only in the same subnet as dst, 0=any dst
  * - local: address, 0=autoselect the local address
  * - scope: maximum allowed scope value for the local address
  */
-__be32 inet_confirm_addr(const struct net_device *dev, __be32 dst, __be32 local, int scope)
+__be32 inet_confirm_addr(struct in_device *in_dev,
+			 __be32 dst, __be32 local, int scope)
 {
 	__be32 addr = 0;
-	struct in_device *in_dev;
-
-	if (dev) {
-		rcu_read_lock();
-		if ((in_dev = __in_dev_get_rcu(dev)))
-			addr = confirm_addr_indev(in_dev, dst, local, scope);
-		rcu_read_unlock();
+	struct net_device *dev;
 
-		return addr;
-	}
+	if (in_dev != NULL)
+		return confirm_addr_indev(in_dev, dst, local, scope);
 
 	read_lock(&dev_base_lock);
 	rcu_read_lock();
-- 
1.5.3.rc5

From: "Denis V. Lunev" <den@openvz.org>
Date: Mon, 14 Jan 2008 17:59:59 +0300

> Make them static.
> 
> Signed-off-by: Denis V. Lunev <den@openvz.org>

It's completely awkward to put the inline after all
the call sites.  A non-global-optimizing compiler
won't be able to even inline it.

I've reworked this patch as follows when applying
it.

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index a0d42a5..ebbfb50 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -213,7 +213,6 @@ extern struct neighbour 	*neigh_event_ns(struct neigh_table *tbl,
 
 extern struct neigh_parms	*neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
 extern void			neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
-extern void			neigh_parms_destroy(struct neigh_parms *parms);
 extern unsigned long		neigh_rand_reach_time(unsigned long base);
 
 extern void			pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
@@ -254,12 +253,6 @@ static inline void __neigh_parms_put(struct neigh_parms *parms)
 	atomic_dec(&parms->refcnt);
 }
 
-static inline void neigh_parms_put(struct neigh_parms *parms)
-{
-	if (atomic_dec_and_test(&parms->refcnt))
-		neigh_parms_destroy(parms);
-}
-
 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
 {
 	atomic_inc(&parms->refcnt);
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 9b0b773..7cc772a 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -577,6 +577,13 @@ static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev)
 	return -ENOENT;
 }
 
+static void neigh_parms_destroy(struct neigh_parms *parms);
+
+static inline void neigh_parms_put(struct neigh_parms *parms)
+{
+	if (atomic_dec_and_test(&parms->refcnt))
+		neigh_parms_destroy(parms);
+}
 
 /*
  *	neighbour must already be out of the table;
@@ -1348,7 +1355,7 @@ void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms)
 	NEIGH_PRINTK1("neigh_parms_release: not found\n");
 }
 
-void neigh_parms_destroy(struct neigh_parms *parms)
+static void neigh_parms_destroy(struct neigh_parms *parms)
 {
 	release_net(parms->net);
 	if (parms->dev)

From: "Denis V. Lunev" <den@openvz.org>
Date: Mon, 14 Jan 2008 17:59:23 +0300

> This set contains a set of small improvements found in IPv4 code during
> preparations to support ARP in the network namespace. These fixes are
> mostly independent except 2 last ones.
> 
> Signed-off-by: Denis V. Lunev <den@openvz.org>

All applied, thanks Denis.