* Add rib_<add|del|change>_route() functions to manipulate the routing table.

The main driver for the change is the need to improve notification mechanism.
Currently callers guess the operation data based on the rtentry structure
 returned in case of successful operation result. There are two problems with
 this appoach. First is that it doesn't provide enough information for the
 upcoming multipath changes, where rtentry refers to a new nexthop group,
 and there is no way of guessing which paths were added during the change.
 Second is that some rtentry fields can change during notification and
 protecting from it by requiring customers to unlock rtentry is not desired.

Additionally, as the consumers such as rtsock do know which operation they
 request in advance, making explicit add/change/del versions of the functions
 makes sense, especially given the functions don't share a lot of code.

With that in mind, introduce rib_cmd_info notification structure and
 rib_<add|del|change>_route() functions, with mandatory rib_cmd_info pointer.
 It will be used in upcoming generalized notifications.

* Move definitions of the new functions and some other functions/structures
 used for the routing table manipulation to a separate header file,
 net/route/route_ctl.h. net/route.h is a frequently used file included in
 ~140 places in kernel, and 90% of the users don't need these definitions.

Reviewed by:	ae
Differential Revision: https://reviews.freebsd.org/D25067

1 files changed, 6 insertions, 3 deletions

diff --git a/sys/net/route/route_var.h b/sys/net/route/route_var.h
index 176084372609..4427ac046ee8 100644
--- a/sys/net/route/route_var.h
+++ b/sys/net/route/route_var.h
@@ -35,6 +35,7 @@
 #ifndef RNF_NORMAL
 #include <net/radix.h>
 #endif
+#include <sys/ck.h>
 #include <sys/epoch.h>
 #include <netinet/in.h>		/* struct sockaddr_in */
 #include <sys/counter.h>
@@ -63,6 +64,7 @@ struct rib_head {
 	struct callout		expire_callout;	/* Callout for expiring dynamic routes */
 	time_t			next_expire;	/* Next expire run ts */
 	struct nh_control	*nh_control;	/* nexthop subsystem data */
+	CK_STAILQ_HEAD(, rib_subscription)	rnh_subscribers;/* notification subscribers */
 };
 
 #define	RIB_RLOCK_TRACKER	struct rm_priotracker _rib_tracker
@@ -110,12 +112,13 @@ void rt_setmetrics(const struct rt_addrinfo *info, struct rtentry *rt);
 struct radix_node *rt_mpath_unlink(struct rib_head *rnh,
     struct rt_addrinfo *info, struct rtentry *rto, int *perror);
 #endif
+struct rib_cmd_info;
 int add_route(struct rib_head *rnh, struct rt_addrinfo *info,
-    struct rtentry **ret_nrt);
+    struct rib_cmd_info *rc);
 int del_route(struct rib_head *rnh, struct rt_addrinfo *info,
-    struct rtentry **ret_nrt);
+    struct rib_cmd_info *rc);
 int change_route(struct rib_head *, struct rt_addrinfo *,
-    struct rtentry **);
+    struct rib_cmd_info *rc);
 
 VNET_PCPUSTAT_DECLARE(struct rtstat, rtstat);
 #define	RTSTAT_ADD(name, val)	\