ipv4: ip_ptr cleanups

dev->ip_ptr is protected by rtnl and rcu.

Yet some places dont use appropriate primitives and/or locking rules.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/plip.c b/drivers/net/plip.c
index 7e82a82..ca4df7f 100644 (file)
--- a/drivers/net/plip.c
+++ b/drivers/net/plip.c
@@ -995,8 +995,10 @@ plip_tx_packet(struct sk_buff *skb, struct net_device *dev)
 static void
 plip_rewrite_address(const struct net_device *dev, struct ethhdr *eth)
 {
-       const struct in_device *in_dev = dev->ip_ptr;
+       const struct in_device *in_dev;
 
+       rcu_read_lock();
+       in_dev = __in_dev_get_rcu(dev);
        if (in_dev) {
                /* Any address will do - we take the first */
                const struct in_ifaddr *ifa = in_dev->ifa_list;
@@ -1006,6 +1008,7 @@ plip_rewrite_address(const struct net_device *dev, struct ethhdr *eth)
                        memcpy(eth->h_dest+2, &ifa->ifa_address, 4);
                }
        }
+       rcu_read_unlock();
 }
 
 static int
@@ -1088,7 +1091,8 @@ plip_open(struct net_device *dev)
           when the device address isn't identical to the address of a
           received frame, the kernel incorrectly drops it).             */
 
-       if ((in_dev=dev->ip_ptr) != NULL) {
+       in_dev=__in_dev_get_rtnl(dev);
+       if (in_dev) {
                /* Any address will do - we take the first. We already
                   have the first two bytes filled with 0xfc, from
                   plip_init_dev(). */

diff --git a/drivers/net/via-velocity.h b/drivers/net/via-velocity.h
index f7b33ae..b5e120b 100644 (file)
--- a/drivers/net/via-velocity.h
+++ b/drivers/net/via-velocity.h
@@ -1504,22 +1504,25 @@ struct velocity_info {
  *     addresses on this chain then we use the first - multi-IP WOL is not
  *     supported.
  *
- *     CHECK ME: locking
  */
 
 static inline int velocity_get_ip(struct velocity_info *vptr)
 {
-       struct in_device *in_dev = (struct in_device *) vptr->dev->ip_ptr;
+       struct in_device *in_dev;
        struct in_ifaddr *ifa;
+       int res = -ENOENT;
 
+       rcu_read_lock();
+       in_dev = __in_dev_get_rcu(vptr->dev);
        if (in_dev != NULL) {
                ifa = (struct in_ifaddr *) in_dev->ifa_list;
                if (ifa != NULL) {
                        memcpy(vptr->ip_addr, &ifa->ifa_address, 4);
-                       return 0;
+                       res = 0;
                }
        }
-       return -ENOENT;
+       rcu_read_unlock();
+       return res;
 }
 
 /**

diff --git a/drivers/net/wan/hdlc_cisco.c b/drivers/net/wan/hdlc_cisco.c
index b38ffa1..b1e5e5b 100644 (file)
--- a/drivers/net/wan/hdlc_cisco.c
+++ b/drivers/net/wan/hdlc_cisco.c
@@ -191,7 +191,8 @@ static int cisco_rx(struct sk_buff *skb)
 
                switch (ntohl (cisco_data->type)) {
                case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */
-                       in_dev = dev->ip_ptr;
+                       rcu_read_lock();
+                       in_dev = __in_dev_get_rcu(dev);
                        addr = 0;
                        mask = ~cpu_to_be32(0); /* is the mask correct? */
 
@@ -211,6 +212,7 @@ static int cisco_rx(struct sk_buff *skb)
                                cisco_keepalive_send(dev, CISCO_ADDR_REPLY,
                                                     addr, mask);
                        }
+                       rcu_read_unlock();
                        dev_kfree_skb_any(skb);
                        return NET_RX_SUCCESS;
 

diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index 2be1a1a..1ec09bb 100644 (file)
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -9,6 +9,7 @@
 #include <linux/rcupdate.h>
 #include <linux/timer.h>
 #include <linux/sysctl.h>
+#include <linux/rtnetlink.h>
 
 enum
 {
@@ -198,14 +199,10 @@ static __inline__ int bad_mask(__be32 mask, __be32 addr)
 
 static inline struct in_device *__in_dev_get_rcu(const struct net_device *dev)
 {
-       struct in_device *in_dev = dev->ip_ptr;
-       if (in_dev)
-               in_dev = rcu_dereference(in_dev);
-       return in_dev;
+       return rcu_dereference(dev->ip_ptr);
 }
 
-static __inline__ struct in_device *
-in_dev_get(const struct net_device *dev)
+static inline struct in_device *in_dev_get(const struct net_device *dev)
 {
        struct in_device *in_dev;
 
@@ -217,10 +214,9 @@ in_dev_get(const struct net_device *dev)
        return in_dev;
 }
 
-static __inline__ struct in_device *
-__in_dev_get_rtnl(const struct net_device *dev)
+static inline struct in_device *__in_dev_get_rtnl(const struct net_device *dev)
 {
-       return (struct in_device*)dev->ip_ptr;
+       return rcu_dereference_check(dev->ip_ptr, lockdep_rtnl_is_held());
 }
 
 extern void in_dev_finish_destroy(struct in_device *idev);

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index af05186..8992fff 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -942,7 +942,7 @@ struct net_device {
        void                    *dsa_ptr;       /* dsa specific data */
 #endif
        void                    *atalk_ptr;     /* AppleTalk link       */
-       void                    *ip_ptr;        /* IPv4 specific data   */
+       struct in_device __rcu  *ip_ptr;        /* IPv4 specific data   */
        void                    *dn_ptr;        /* DECnet specific data */
        void                    *ip6_ptr;       /* IPv6 specific data */
        void                    *ec_ptr;        /* Econet specific data */

diff --git a/net/core/dev.c b/net/core/dev.c
index fc2dc93..5bdce97 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5286,7 +5286,7 @@ void netdev_run_todo(void)
 
                /* paranoia */
                BUG_ON(atomic_read(&dev->refcnt));
-               WARN_ON(dev->ip_ptr);
+               WARN_ON(rcu_dereference_raw(dev->ip_ptr));
                WARN_ON(dev->ip6_ptr);
                WARN_ON(dev->dn_ptr);
 

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index da14c49..c2ff48f 100644 (file)
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -209,7 +209,7 @@ static void inetdev_destroy(struct in_device *in_dev)
                inet_free_ifa(ifa);
        }
 
-       dev->ip_ptr = NULL;
+       rcu_assign_pointer(dev->ip_ptr, NULL);
 
        devinet_sysctl_unregister(in_dev);
        neigh_parms_release(&arp_tbl, in_dev->arp_parms);
@@ -1059,7 +1059,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
        switch (event) {
        case NETDEV_REGISTER:
                printk(KERN_DEBUG "inetdev_event: bug\n");
-               dev->ip_ptr = NULL;
+               rcu_assign_pointer(dev->ip_ptr, NULL);
                break;
        case NETDEV_UP:
                if (!inetdev_valid_mtu(dev->mtu))

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 179fcab..10b24c0 100644 (file)
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -724,7 +724,7 @@ static int vif_add(struct net *net, struct mr_table *mrt,
        case 0:
                if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
                        dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
-                       if (dev && dev->ip_ptr == NULL) {
+                       if (dev && __in_dev_get_rtnl(dev) == NULL) {
                                dev_put(dev);
                                return -EADDRNOTAVAIL;
                        }

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 4935b84..b8cf282 100644 (file)
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -362,7 +362,7 @@ static int ieee80211_ifa_changed(struct notifier_block *nb,
        if (sdata->vif.type != NL80211_IFTYPE_STATION)
                return NOTIFY_DONE;
 
-       idev = sdata->dev->ip_ptr;
+       idev = __in_dev_get_rtnl(sdata->dev);
        if (!idev)
                return NOTIFY_DONE;