Merge branch 'net-Kernel-side-filtering-for-route-dumps'

David Ahern says:

====================
net: Kernel side filtering for route dumps

Implement kernel side filtering of route dumps by protocol (e.g., which
routing daemon installed the route), route type (e.g., unicast), table
id and nexthop device.

iproute2 has been doing this filtering in userspace for years; pushing
the filters to the kernel side reduces the amount of data the kernel
sends and reduces wasted cycles on both sides processing unwanted data.
These initial options provide a huge improvement for efficiently
examining routes on large scale systems.

v2
- better handling of requests for a specific table. Rather than walking
  the hash of all tables, lookup the specific table and dump it
- refactor mr_rtm_dumproute moving the loop over the table into a
  helper that can be invoked directly
- add hook to return NLM_F_DUMP_FILTERED in DONE message to ensure
  it is returned even when the dump returns nothing
====================

Signed-off-by: David S. Miller <[email protected]>

2 files changed, 10 insertions, 2 deletions

diff --git a/include/linux/mroute_base.h b/include/linux/mroute_base.h
index 6675b9f81979..34de06b426ef 100644
--- a/include/linux/mroute_base.h
+++ b/include/linux/mroute_base.h
@@ -7,6 +7,7 @@
 #include <net/net_namespace.h>
 #include <net/sock.h>
 #include <net/fib_notifier.h>
+#include <net/ip_fib.h>
 
 /**
  * struct vif_device - interface representor for multicast routing
@@ -283,6 +284,12 @@ void *mr_mfc_find_any(struct mr_table *mrt, int vifi, void *hasharg);
 
 int mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
 		   struct mr_mfc *c, struct rtmsg *rtm);
+int mr_table_dump(struct mr_table *mrt, struct sk_buff *skb,
+		  struct netlink_callback *cb,
+		  int (*fill)(struct mr_table *mrt, struct sk_buff *skb,
+			      u32 portid, u32 seq, struct mr_mfc *c,
+			      int cmd, int flags),
+		  spinlock_t *lock, struct fib_dump_filter *filter);
 int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
 		     struct mr_table *(*iter)(struct net *net,
 					      struct mr_table *mrt),
@@ -290,7 +297,7 @@ int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
 				 struct sk_buff *skb,
 				 u32 portid, u32 seq, struct mr_mfc *c,
 				 int cmd, int flags),
-		     spinlock_t *lock);
+		     spinlock_t *lock, struct fib_dump_filter *filter);
 
 int mr_dump(struct net *net, struct notifier_block *nb, unsigned short family,
 	    int (*rules_dump)(struct net *net,
@@ -340,7 +347,7 @@ mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
 			     struct sk_buff *skb,
 			     u32 portid, u32 seq, struct mr_mfc *c,
 			     int cmd, int flags),
-		 spinlock_t *lock)
+		 spinlock_t *lock, struct fib_dump_filter *filter)
 {
 	return -EINVAL;
 }
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 72580f1a72a2..4da90a6ab536 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -180,6 +180,7 @@ struct netlink_callback {
 	u16			family;
 	u16			min_dump_alloc;
 	bool			strict_check;
+	u16			answer_flags;
 	unsigned int		prev_seq, seq;
 	long			args[6];
 };