netdev - [IFGROUPv4 1/3] rtnetlink: setlink changes atomic with single notification

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <11933245922165-git-send-email-panther@balabit.hu>
Date:	Thu, 25 Oct 2007 17:03:07 +0200
From:	Laszlo Attila Toth <panther@...abit.hu>
To:	David Miller <davem@...emloft.net>, netdev@...r.kernel.org
Cc:	Laszlo Attila Toth <panther@...abit.hu>
Subject: [IFGROUPv4 1/3] rtnetlink: setlink changes atomic with single notification

In do_setlink the device changes are atomic and notifications will be sent
at the end of the function once if any modification occured and once if
address has been changed.

Signed-off-by: Laszlo Attila Toth <panther@...abit.hu>
---
 net/core/rtnetlink.c |   34 ++++++++++++++++++++++++----------
 1 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 4a2640d..ecf4dc5 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -537,7 +537,7 @@ int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id,
 
 EXPORT_SYMBOL_GPL(rtnl_put_cacheinfo);
 
-static void set_operstate(struct net_device *dev, unsigned char transition)
+static int set_operstate(struct net_device *dev, unsigned char transition)
 {
 	unsigned char operstate = dev->operstate;
 
@@ -560,8 +560,9 @@ static void set_operstate(struct net_device *dev, unsigned char transition)
 		write_lock_bh(&dev_base_lock);
 		dev->operstate = operstate;
 		write_unlock_bh(&dev_base_lock);
-		netdev_state_change(dev);
-	}
+		return 1;
+	} else
+		return 0;
 }
 
 static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
@@ -855,6 +856,7 @@ static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
 	if (tb[IFLA_BROADCAST]) {
 		nla_memcpy(dev->broadcast, tb[IFLA_BROADCAST], dev->addr_len);
 		send_addr_notify = 1;
+		modified = 1;
 	}
 
 	if (ifm->ifi_flags || ifm->ifi_change) {
@@ -867,16 +869,26 @@ static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
 		dev_change_flags(dev, flags);
 	}
 
-	if (tb[IFLA_TXQLEN])
-		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
+	if (tb[IFLA_TXQLEN]) {
+		if (dev->tx_queue_len != nla_get_u32(tb[IFLA_TXQLEN])) {
+			write_lock_bh(&dev_base_lock);
+			dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
+			write_unlock_bh(&dev_base_lock);
+			modified = 1;
+		}
+	}
 
-	if (tb[IFLA_OPERSTATE])
-		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
+	if (tb[IFLA_OPERSTATE]) {
+		modified |= set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
+	}
 
 	if (tb[IFLA_LINKMODE]) {
-		write_lock_bh(&dev_base_lock);
-		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
-		write_unlock_bh(&dev_base_lock);
+		if (dev->link_mode != nla_get_u8(tb[IFLA_LINKMODE])) {
+			write_lock_bh(&dev_base_lock);
+			dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
+			write_unlock_bh(&dev_base_lock);
+			modified = 1;
+		}
 	}
 
 	err = 0;
@@ -890,6 +902,8 @@ errout:
 
 	if (send_addr_notify)
 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
+	if (modified)
+		netdev_state_change(dev);
 	return err;
 }
 
-- 
1.5.2.5

-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html