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authorAndy Gospodarek <andy@greyhouse.net>2012-03-22 20:14:29 +0400
committerDavid S. Miller <davem@davemloft.net>2012-03-23 06:36:17 +0400
commiteaddcd76903c28e84bb452a35835babb0800a2c4 (patch)
tree97e512e21955da69d434a34b4e073ba880ec7d3d /net/ipv4
parent523f610e1be2a4afca605962e137064378883c5f (diff)
downloadlinux-eaddcd76903c28e84bb452a35835babb0800a2c4.tar.xz
bonding: remove entries for master_ip and vlan_ip and query devices instead
The following patch aimed to resolve an issue where secondary, tertiary, etc. addresses added to bond interfaces could overwrite the bond->master_ip and vlan_ip values. commit 917fbdb32f37e9a93b00bb12ee83532982982df3 Author: Henrik Saavedra Persson <henrik.e.persson@ericsson.com> Date: Wed Nov 23 23:37:15 2011 +0000 bonding: only use primary address for ARP That patch was good because it prevented bonds using ARP monitoring from sending frames with an invalid source IP address. Unfortunately, it didn't always work as expected. When using an ioctl (like ifconfig does) to set the IP address and netmask, 2 separate ioctls are actually called to set the IP and netmask if the mask chosen doesn't match the standard mask for that class of address. The first ioctl did not have a mask that matched the one in the primary address and would still cause the device address to be overwritten. The second ioctl that was called to set the mask would then detect as secondary and ignored, but the damage was already done. This was not an issue when using an application that used netlink sockets as the setting of IP and netmask came down at once. The inconsistent behavior between those two interfaces was something that needed to be resolved. While I was thinking about how I wanted to resolve this, Ralf Zeidler came with a patch that resolved this on a RHEL kernel by keeping a full shadow of the entries in dev->ifa_list for the bonding device and vlan devices in the bonding driver. I didn't like the duplication of the list as I want to see the 'bonding' struct and code shrink rather than grow, but liked the general idea. As the Subject indicates this patch drops the master_ip and vlan_ip elements from the 'bonding' and 'vlan_entry' structs, respectively. This can be done because a device's address-list is now traversed to determine the optimal source IP address for ARP requests and for checks to see if the bonding device has a particular IP address. This code could have all be contained inside the bonding driver, but it made more sense to me to EXPORT and call inet_confirm_addr since it did exactly what was needed. I tested this and a backported patch and everything works as expected. Ralf also helped with verification of the backported patch. Thanks to Ralf for all his help on this. v2: Whitespace and organizational changes based on suggestions from Jay Vosburgh and Dave Miller. v3: Fixup incorrect usage of rcu_read_unlock based on Dave Miller's suggestion. Signed-off-by: Andy Gospodarek <andy@greyhouse.net> CC: Ralf Zeidler <ralf.zeidler@nsn.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/devinet.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index e41c40f48cfe..d4fad5c77447 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1079,6 +1079,7 @@ __be32 inet_confirm_addr(struct in_device *in_dev,
return addr;
}
+EXPORT_SYMBOL(inet_confirm_addr);
/*
* Device notifier