ipmr: Add FIB notification access functions

Make the ipmr module register as a FIB notifier. To do that, implement both
the ipmr_seq_read and ipmr_dump ops.

The ipmr_seq_read op returns a sequence counter that is incremented on
every notification related operation done by the ipmr. To implement that,
add a sequence counter in the netns_ipv4 struct and increment it whenever a
new MFC route or VIF are added or deleted. The sequence operations are
protected by the RTNL lock.

The ipmr_dump iterates the list of MFC routes and the list of VIF entries
and sends notifications about them. The entries dump is done under RCU
where the VIF dump uses the mrt_lock too, as the vif->dev field can change
under RCU.

Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/mroute.h b/include/linux/mroute.h
index 10028f208efb..54c5cb82ddcb 100644
--- a/include/linux/mroute.h
+++ b/include/linux/mroute.h
@@ -5,6 +5,7 @@
 #include <linux/pim.h>
 #include <linux/rhashtable.h>
 #include <net/sock.h>
+#include <net/fib_notifier.h>
 #include <uapi/linux/mroute.h>
 
 #ifdef CONFIG_IP_MROUTE
@@ -58,6 +59,14 @@ struct vif_device {
 	int		link;			/* Physical interface index	*/
 };
 
+struct vif_entry_notifier_info {
+	struct fib_notifier_info info;
+	struct net_device *dev;
+	vifi_t vif_index;
+	unsigned short vif_flags;
+	u32 tb_id;
+};
+
 #define VIFF_STATIC 0x8000
 
 #define VIF_EXISTS(_mrt, _idx) ((_mrt)->vif_table[_idx].dev != NULL)
@@ -146,6 +155,12 @@ struct mfc_cache {
 	struct rcu_head	rcu;
 };
 
+struct mfc_entry_notifier_info {
+	struct fib_notifier_info info;
+	struct mfc_cache *mfc;
+	u32 tb_id;
+};
+
 struct rtmsg;
 int ipmr_get_route(struct net *net, struct sk_buff *skb,
 		   __be32 saddr, __be32 daddr,