First pass at separating per-vnet initializer functions

        from existing functions for initializing global state.

        At this stage, the new per-vnet initializer functions are
	directly called from the existing global initialization code,
	which should in most cases result in compiler inlining those
	new functions, hence yielding a near-zero functional change.

        Modify the existing initializer functions which are invoked via
        protosw, like ip_init() et. al., to allow them to be invoked
	multiple times, i.e. per each vnet.  Global state, if any,
	is initialized only if such functions are called within the
	context of vnet0, which will be determined via the
	IS_DEFAULT_VNET(curvnet) check (currently always true).

        While here, V_irtualize a few remaining global UMA zones
        used by net/netinet/netipsec networking code.  While it is
        not yet clear to me or anybody else whether this is the right
        thing to do, at this stage this makes the code more readable,
        and makes it easier to track uncollected UMA-zone-backed
        objects on vnet removal.  In the long run, it's quite possible
        that some form of shared use of UMA zone pools among multiple
        vnets should be considered.

	Bump __FreeBSD_version due to changes in layout of structs
	vnet_ipfw, vnet_inet and vnet_net.

Approved by:	julian (mentor)

1 files changed, 16 insertions, 5 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index d9af711..20627d3 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -150,6 +150,8 @@ static int	if_getgroupmembers(struct ifgroupreq *);
 extern void	nd6_setmtu(struct ifnet *);
 #endif
 
+static int	vnet_net_iattach(const void *);
+
 #ifdef VIMAGE_GLOBALS
 struct	ifnethead ifnet;	/* depend on static init XXX */
 struct	ifgrouphead ifg_head;
@@ -391,24 +393,33 @@ filt_netdev(struct knote *kn, long hint)
 static void
 if_init(void *dummy __unused)
 {
-	INIT_VNET_NET(curvnet);
 
 #ifndef VIMAGE_GLOBALS
 	vnet_mod_register(&vnet_net_modinfo);
 #endif
+	vnet_net_iattach(NULL);
+
+	IFNET_LOCK_INIT();
+	ifdev_setbyindex(0, make_dev(&net_cdevsw, 0, UID_ROOT, GID_WHEEL,
+	    0600, "network"));
+	if_clone_init();
+}
+
+static int
+vnet_net_iattach(const void *unused __unused)
+{
+	INIT_VNET_NET(curvnet);
 
 	V_if_index = 0;
 	V_ifindex_table = NULL;
 	V_if_indexlim = 8;
 
-	IFNET_LOCK_INIT();
 	TAILQ_INIT(&V_ifnet);
 	TAILQ_INIT(&V_ifg_head);
 	knlist_init(&V_ifklist, NULL, NULL, NULL, NULL);
 	if_grow();				/* create initial table */
-	ifdev_setbyindex(0, make_dev(&net_cdevsw, 0, UID_ROOT, GID_WHEEL,
-	    0600, "network"));
-	if_clone_init();
+
+	return (0);
 }
 
 static void