27 files changed, 335 insertions, 30 deletions

diff --git a/sys/net/bpf.c b/sys/net/bpf.c
index 5a2ab19160ee..08c9a5eee26b 100644
--- a/sys/net/bpf.c
+++ b/sys/net/bpf.c
@@ -56,7 +56,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/sockio.h>
 #include <sys/ttycom.h>
 #include <sys/uio.h>
-#include <sys/vimage.h>
 
 #include <sys/event.h>
 #include <sys/file.h>
@@ -73,6 +72,7 @@ __FBSDID("$FreeBSD$");
 #endif
 #include <net/bpf_zerocopy.h>
 #include <net/bpfdesc.h>
+#include <net/vnet.h>
 
 #include <netinet/in.h>
 #include <netinet/if_ether.h>
diff --git a/sys/net/bridgestp.c b/sys/net/bridgestp.c
index 9349be44b767..3e65113c2d56 100644
--- a/sys/net/bridgestp.c
+++ b/sys/net/bridgestp.c
@@ -49,7 +49,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/taskqueue.h>
-#include <sys/vimage.h>
 
 #include <net/if.h>
 #include <net/if_dl.h>
diff --git a/sys/net/flowtable.c b/sys/net/flowtable.c
index 1fe2bbe69b8d..4078ae9138e1 100644
--- a/sys/net/flowtable.c
+++ b/sys/net/flowtable.c
@@ -48,7 +48,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/socket.h>
 #include <sys/syslog.h>
 #include <sys/sysctl.h>
-#include <sys/vimage.h>
 
 #include <net/if.h>
 #include <net/if_llatbl.h>
diff --git a/sys/net/if.c b/sys/net/if.c
index 02796cbcf6c0..3ac7db05c14b 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -59,7 +59,6 @@
 #include <sys/taskqueue.h>
 #include <sys/domain.h>
 #include <sys/jail.h>
-#include <sys/vimage.h>
 #include <machine/stdarg.h>
 #include <vm/uma.h>
 
diff --git a/sys/net/if_bridge.c b/sys/net/if_bridge.c
index 945bc5f2e661..ced953a52f0f 100644
--- a/sys/net/if_bridge.c
+++ b/sys/net/if_bridge.c
@@ -101,7 +101,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/rwlock.h>
-#include <sys/vimage.h>
 
 #include <net/bpf.h>
 #include <net/if.h>
diff --git a/sys/net/if_clone.c b/sys/net/if_clone.c
index 95c07b731d0c..0dd20fb36108 100644
--- a/sys/net/if_clone.c
+++ b/sys/net/if_clone.c
@@ -39,7 +39,6 @@
 #include <sys/systm.h>
 #include <sys/types.h>
 #include <sys/socket.h>
-#include <sys/vimage.h>
 
 #include <net/if.h>
 #include <net/if_clone.h>
diff --git a/sys/net/if_ef.c b/sys/net/if_ef.c
index c0b2d671759a..7a5fca916d7f 100644
--- a/sys/net/if_ef.c
+++ b/sys/net/if_ef.c
@@ -39,7 +39,6 @@
 #include <sys/syslog.h>
 #include <sys/kernel.h>
 #include <sys/module.h>
-#include <sys/vimage.h>
 
 #include <net/ethernet.h>
 #include <net/if_llc.h>
diff --git a/sys/net/if_enc.c b/sys/net/if_enc.c
index 7b62734d14c7..a49c5dc5b236 100644
--- a/sys/net/if_enc.c
+++ b/sys/net/if_enc.c
@@ -38,7 +38,6 @@
 #include <sys/socket.h>
 #include <sys/sockio.h>
 #include <sys/sysctl.h>
-#include <sys/vimage.h>
 
 #include <net/if.h>
 #include <net/if_clone.h>
diff --git a/sys/net/if_epair.c b/sys/net/if_epair.c
index e299d972bb2d..00f99fdfa5c0 100644
--- a/sys/net/if_epair.c
+++ b/sys/net/if_epair.c
@@ -38,7 +38,7 @@
 /*
  * Things to re-think once we have more experience:
  * - ifp->if_reassign function once we can test with vimage. Depending on
- *   how if_vomve() is going to be improved.
+ *   how if_vmove() is going to be improved.
  * - Real random etheraddrs that are checked to be uniquish; we would need
  *   to re-do them in case we move the interface between network stacks
  *   in a private if_reassign function.
@@ -61,7 +61,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/sockio.h>
 #include <sys/sysctl.h>
 #include <sys/types.h>
-#include <sys/vimage.h>
 
 #include <net/bpf.h>
 #include <net/ethernet.h>
@@ -70,6 +69,7 @@ __FBSDID("$FreeBSD$");
 #include <net/if_var.h>
 #include <net/if_types.h>
 #include <net/netisr.h>
+#include <net/vnet.h>
 
 #define	EPAIRNAME	"epair"
 
diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index 545d9ee1a481..bac204449230 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -50,7 +50,6 @@
 #include <sys/socket.h>
 #include <sys/sockio.h>
 #include <sys/sysctl.h>
-#include <sys/vimage.h>
 
 #include <net/if.h>
 #include <net/if_arp.h>
diff --git a/sys/net/if_faith.c b/sys/net/if_faith.c
index cbca740ed5db..ca8088362a96 100644
--- a/sys/net/if_faith.c
+++ b/sys/net/if_faith.c
@@ -54,7 +54,6 @@
 #include <sys/queue.h>
 #include <sys/types.h>
 #include <sys/malloc.h>
-#include <sys/vimage.h>
 
 #include <net/if.h>
 #include <net/if_clone.h>
@@ -62,6 +61,7 @@
 #include <net/netisr.h>
 #include <net/route.h>
 #include <net/bpf.h>
+#include <net/vnet.h>
 
 #ifdef	INET
 #include <netinet/in.h>
diff --git a/sys/net/if_gif.c b/sys/net/if_gif.c
index 3d75dd46e42e..6abc8071e021 100644
--- a/sys/net/if_gif.c
+++ b/sys/net/if_gif.c
@@ -49,7 +49,6 @@
 #include <sys/proc.h>
 #include <sys/protosw.h>
 #include <sys/conf.h>
-#include <sys/vimage.h>
 #include <machine/cpu.h>
 
 #include <net/if.h>
@@ -58,6 +57,7 @@
 #include <net/netisr.h>
 #include <net/route.h>
 #include <net/bpf.h>
+#include <net/vnet.h>
 
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
diff --git a/sys/net/if_gre.c b/sys/net/if_gre.c
index 4ed2a9ef13f5..2b283d69e3d7 100644
--- a/sys/net/if_gre.c
+++ b/sys/net/if_gre.c
@@ -64,13 +64,13 @@
 #include <sys/sockio.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
-#include <sys/vimage.h>
 
 #include <net/ethernet.h>
 #include <net/if.h>
 #include <net/if_clone.h>
 #include <net/if_types.h>
 #include <net/route.h>
+#include <net/vnet.h>
 
 #ifdef INET
 #include <netinet/in.h>
diff --git a/sys/net/if_llatbl.c b/sys/net/if_llatbl.c
index b5da1ea44360..a1b574f9f371 100644
--- a/sys/net/if_llatbl.c
+++ b/sys/net/if_llatbl.c
@@ -41,7 +41,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/rwlock.h>
-#include <sys/vimage.h>
 
 #include <vm/uma.h>
 
@@ -51,6 +50,7 @@ __FBSDID("$FreeBSD$");
 #include <net/if_dl.h>
 #include <net/if_var.h>
 #include <net/route.h>
+#include <net/vnet.h>
 #include <netinet/if_ether.h>
 #include <netinet6/in6_var.h>
 #include <netinet6/nd6.h>
diff --git a/sys/net/if_loop.c b/sys/net/if_loop.c
index 043c808f7f0c..056b2f93a353 100644
--- a/sys/net/if_loop.c
+++ b/sys/net/if_loop.c
@@ -49,7 +49,6 @@
 #include <sys/socket.h>
 #include <sys/sockio.h>
 #include <sys/sysctl.h>
-#include <sys/vimage.h>
 
 #include <net/if.h>
 #include <net/if_clone.h>
diff --git a/sys/net/if_mib.c b/sys/net/if_mib.c
index c0018efae9ba..c334ac7f1a44 100644
--- a/sys/net/if_mib.c
+++ b/sys/net/if_mib.c
@@ -34,7 +34,6 @@
 #include <sys/kernel.h>
 #include <sys/socket.h>
 #include <sys/sysctl.h>
-#include <sys/vimage.h>
 
 #include <net/if.h>
 #include <net/if_mib.h>
diff --git a/sys/net/if_spppsubr.c b/sys/net/if_spppsubr.c
index 2c325eea9bdd..3f0faafa3d6c 100644
--- a/sys/net/if_spppsubr.c
+++ b/sys/net/if_spppsubr.c
@@ -36,7 +36,6 @@
 #include <sys/random.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
-#include <sys/vimage.h>
 
 #include <sys/md5.h>
 
@@ -44,6 +43,7 @@
 #include <net/netisr.h>
 #include <net/if_types.h>
 #include <net/route.h>
+#include <net/vnet.h>
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
 #include <netinet/ip.h>
diff --git a/sys/net/if_stf.c b/sys/net/if_stf.c
index ddc56629b2aa..5c082c4926a6 100644
--- a/sys/net/if_stf.c
+++ b/sys/net/if_stf.c
@@ -92,7 +92,6 @@
 #include <machine/cpu.h>
 
 #include <sys/malloc.h>
-#include <sys/vimage.h>
 
 #include <net/if.h>
 #include <net/if_clone.h>
@@ -100,6 +99,7 @@
 #include <net/netisr.h>
 #include <net/if_types.h>
 #include <net/if_stf.h>
+#include <net/vnet.h>
 
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
diff --git a/sys/net/if_tun.c b/sys/net/if_tun.c
index a9a1c62d0810..37b5e70302c1 100644
--- a/sys/net/if_tun.c
+++ b/sys/net/if_tun.c
@@ -43,13 +43,13 @@
 #include <sys/uio.h>
 #include <sys/malloc.h>
 #include <sys/random.h>
-#include <sys/vimage.h>
 
 #include <net/if.h>
 #include <net/if_clone.h>
 #include <net/if_types.h>
 #include <net/netisr.h>
 #include <net/route.h>
+#include <net/vnet.h>
 #ifdef INET
 #include <netinet/in.h>
 #endif
diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c
index ac7287006d12..04c2c0dc6448 100644
--- a/sys/net/if_vlan.c
+++ b/sys/net/if_vlan.c
@@ -55,7 +55,6 @@
 #include <sys/sockio.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
-#include <sys/vimage.h>
 
 #include <net/bpf.h>
 #include <net/ethernet.h>
diff --git a/sys/net/netisr.c b/sys/net/netisr.c
index b2db8c153aec..c8da579834e3 100644
--- a/sys/net/netisr.c
+++ b/sys/net/netisr.c
@@ -78,7 +78,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/socket.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
-#include <sys/vimage.h>
 
 #ifdef DDB
 #include <ddb/ddb.h>
@@ -87,6 +86,7 @@ __FBSDID("$FreeBSD$");
 #include <net/if.h>
 #include <net/if_var.h>
 #include <net/netisr.h>
+#include <net/vnet.h>
 
 /*-
  * Synchronize use and modification of the registered netisr data structures;
diff --git a/sys/net/raw_cb.c b/sys/net/raw_cb.c
index 30a526fbbeab..c430d973d84a 100644
--- a/sys/net/raw_cb.c
+++ b/sys/net/raw_cb.c
@@ -42,7 +42,6 @@
 #include <sys/socketvar.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
-#include <sys/vimage.h>
 
 #include <net/if.h>
 #include <net/raw_cb.h>
diff --git a/sys/net/raw_usrreq.c b/sys/net/raw_usrreq.c
index 0759e427483a..2de3d692163a 100644
--- a/sys/net/raw_usrreq.c
+++ b/sys/net/raw_usrreq.c
@@ -44,7 +44,6 @@
 #include <sys/socketvar.h>
 #include <sys/sx.h>
 #include <sys/systm.h>
-#include <sys/vimage.h>
 
 #include <net/if.h>
 #include <net/raw_cb.h>
diff --git a/sys/net/route.c b/sys/net/route.c
index 544c3b643629..fc76c924c66e 100644
--- a/sys/net/route.c
+++ b/sys/net/route.c
@@ -51,11 +51,11 @@
 #include <sys/proc.h>
 #include <sys/domain.h>
 #include <sys/kernel.h>
-#include <sys/vimage.h>
 
 #include <net/if.h>
 #include <net/if_dl.h>
 #include <net/route.h>
+#include <net/vnet.h>
 
 #ifdef RADIX_MPATH
 #include <net/radix_mpath.h>
diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index 88c980703065..645cf7e54eb8 100644
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -50,7 +50,6 @@
 #include <sys/socketvar.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
-#include <sys/vimage.h>
 
 #include <net/if.h>
 #include <net/if_dl.h>
diff --git a/sys/net/vnet.c b/sys/net/vnet.c
index eed353e644b6..a34270a3eea6 100644
--- a/sys/net/vnet.c
+++ b/sys/net/vnet.c
@@ -1,4 +1,12 @@
 /*-
+ * Copyright (c) 2004-2009 University of Zagreb
+ * Copyright (c) 2006-2009 FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by the University of Zagreb and the
+ * FreeBSD Foundation under sponsorship by the Stichting NLnet and the
+ * FreeBSD Foundation.
+ *
  * Copyright (c) 2009 Jeffrey Roberson <jeff@freebsd.org>
  * Copyright (c) 2009 Robert N. M. Watson
  * All rights reserved.
@@ -28,30 +36,67 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include "opt_ddb.h"
+
 #include <sys/param.h>
 #include <sys/kernel.h>
+#include <sys/jail.h>
 #include <sys/systm.h>
 #include <sys/sysctl.h>
 #include <sys/linker_set.h>
 #include <sys/lock.h>
 #include <sys/malloc.h>
 #include <sys/proc.h>
+#include <sys/socket.h>
 #include <sys/sx.h>
 #include <sys/sysctl.h>
-#include <sys/vimage.h>
 
+#ifdef DDB
+#include <ddb/ddb.h>
+#endif
+
+#include <net/if.h>
+#include <net/if_var.h>
 #include <net/vnet.h>
 
 /*-
  * This file implements core functions for virtual network stacks:
  *
+ * - Core virtual network stack management functions.
+ *
  * - Virtual network stack memory allocator, which virtualized global
  *   variables in the network stack
  *
  * - Virtualized SYSINIT's/SYSUNINIT's, which allow network stack subsystems
  *   to register startup/shutdown events to be run for each virtual network
  *   stack instance.
- *
+ */
+
+MALLOC_DEFINE(M_VNET, "vnet", "network stack control block");
+
+/*
+ * The virtual network stack list has two read-write locks, one sleepable and
+ * the other not, so that the list can be stablized and walked in a variety
+ * of network stack contexts.  Both must be acquired exclusively to modify
+ * the list.
+ */
+struct rwlock		vnet_rwlock;
+struct sx		vnet_sxlock;
+
+#define	VNET_LIST_WLOCK() do {						\
+	sx_xlock(&vnet_sxlock);						\
+	rw_wlock(&vnet_rwlock);						\
+} while (0)
+
+#define	VNET_LIST_WUNLOCK() do {					\
+	rw_wunlock(&vnet_rwlock);					\
+	sx_xunlock(&vnet_sxlock);					\
+} while (0)
+
+struct vnet_list_head vnet_head;
+struct vnet *vnet0;
+
+/*
  * The virtual network stack allocator provides storage for virtualized
  * global variables.  These variables are defined/declared using the
  * VNET_DEFINE()/VNET_DECLARE() macros, which place them in the 'set_vnet'
@@ -157,6 +202,114 @@ static TAILQ_HEAD(, vnet_data_free) vnet_data_free_head =
 static struct sx vnet_data_free_lock;
 
 /*
+ * Allocate a virtual network stack.
+ */
+struct vnet *
+vnet_alloc(void)
+{
+	struct vnet *vnet;
+
+	vnet = malloc(sizeof(struct vnet), M_VNET, M_WAITOK | M_ZERO);
+	vnet->vnet_magic_n = VNET_MAGIC_N;
+	vnet_data_init(vnet);
+
+	/* Initialize / attach vnet module instances. */
+	CURVNET_SET_QUIET(vnet);
+
+	sx_xlock(&vnet_sxlock);
+	vnet_sysinit();
+	CURVNET_RESTORE();
+
+	rw_wlock(&vnet_rwlock);
+	LIST_INSERT_HEAD(&vnet_head, vnet, vnet_le);
+	VNET_LIST_WUNLOCK();
+
+	return (vnet);
+}
+
+/*
+ * Destroy a virtual network stack.
+ */
+void
+vnet_destroy(struct vnet *vnet)
+{
+	struct ifnet *ifp, *nifp;
+
+	KASSERT(vnet->vnet_sockcnt == 0,
+	    ("%s: vnet still has sockets", __func__));
+
+	VNET_LIST_WLOCK();
+	LIST_REMOVE(vnet, vnet_le);
+	rw_wunlock(&vnet_rwlock);
+
+	CURVNET_SET_QUIET(vnet);
+
+	/* Return all inherited interfaces to their parent vnets. */
+	TAILQ_FOREACH_SAFE(ifp, &V_ifnet, if_link, nifp) {
+		if (ifp->if_home_vnet != ifp->if_vnet)
+			if_vmove(ifp, ifp->if_home_vnet);
+	}
+
+	vnet_sysuninit();
+	sx_xunlock(&vnet_sxlock);
+
+	CURVNET_RESTORE();
+
+	/* Hopefully, we are OK to free the vnet container itself. */
+	vnet_data_destroy(vnet);
+	vnet->vnet_magic_n = 0xdeadbeef;
+	free(vnet, M_VNET);
+}
+
+static void
+vnet_foreach(void (*vnet_foreach_fn)(struct vnet *, void *), void *arg)
+{
+	struct vnet *vnet;
+
+	VNET_LIST_RLOCK();
+	LIST_FOREACH(vnet, &vnet_head, vnet_le)
+		vnet_foreach_fn(vnet, arg);
+	VNET_LIST_RUNLOCK();
+}
+
+/*
+ * Boot time initialization and allocation of virtual network stacks.
+ */
+static void
+vnet_init_prelink(void *arg)
+{
+
+	rw_init(&vnet_rwlock, "vnet_rwlock");
+	sx_init(&vnet_sxlock, "vnet_sxlock");
+	LIST_INIT(&vnet_head);
+}
+SYSINIT(vnet_init_prelink, SI_SUB_VNET_PRELINK, SI_ORDER_FIRST,
+    vnet_init_prelink, NULL);
+
+static void
+vnet0_init(void *arg)
+{
+
+	/*
+	 * We MUST clear curvnet in vi_init_done() before going SMP,
+	 * otherwise CURVNET_SET() macros would scream about unnecessary
+	 * curvnet recursions.
+	 */
+	curvnet = prison0.pr_vnet = vnet0 = vnet_alloc();
+}
+SYSINIT(vnet0_init, SI_SUB_VNET, SI_ORDER_FIRST, vnet0_init, NULL);
+
+static void
+vnet_init_done(void *unused)
+{
+
+	curvnet = NULL;
+}
+
+SYSINIT(vnet_init_done, SI_SUB_VNET_DONE, SI_ORDER_FIRST, vnet_init_done,
+    NULL);
+
+/*
  * Allocate storage for virtualized global variables in a new virtual network
  * stack instance, and copy in initial values from our 'master' copy.
  */
@@ -490,3 +643,20 @@ vnet_sysuninit(void)
 		vs->func(vs->arg);
 	}
 }
+
+#ifdef DDB
+DB_SHOW_COMMAND(vnets, db_show_vnets)
+{
+	VNET_ITERATOR_DECL(vnet_iter);
+
+#if SIZE_MAX == UINT32_MAX /* 32-bit arch */
+	db_printf("      vnet ifs socks\n");
+#else /* 64-bit arch, most probaly... */
+	db_printf("              vnet ifs socks\n");
+#endif
+	VNET_FOREACH(vnet_iter) {
+		db_printf("%p %3d %5d\n", vnet_iter, vnet_iter->vnet_ifcnt,
+		    vnet_iter->vnet_sockcnt);
+	}
+}
+#endif
diff --git a/sys/net/vnet.h b/sys/net/vnet.h
index 08ee21a8d871..47dc7ac03b46 100644
--- a/sys/net/vnet.h
+++ b/sys/net/vnet.h
@@ -1,4 +1,12 @@
 /*-
+ * Copyright (c) 2006-2009 University of Zagreb
+ * Copyright (c) 2006-2009 FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by the University of Zagreb and the
+ * FreeBSD Foundation under sponsorship by the Stichting NLnet and the
+ * FreeBSD Foundation.
+ *
  * Copyright (c) 2009 Jeffrey Roberson <jeff@freebsd.org>
  * Copyright (c) 2009 Robert N. M. Watson
  * All rights reserved.
@@ -31,6 +39,9 @@
  * This header file defines several sets of interfaces supporting virtualized
  * network stacks:
  *
+ * - Definition of 'struct vnet' and functions and macros to allocate/free/
+ *   manipulate it.
+ *
  * - A virtual network stack memory allocator, which provides support for
  *   virtualized global variables via a special linker set, set_vnet.
  *
@@ -47,17 +58,133 @@
 #define	_NET_VNET_H_
 
 /*
- * Virtual network stack memory allocator, which allows global variables to
- * be automatically instantiated for each network stack instance.
+ * struct vnet describes a virtualized network stack, and is primarily a
+ * pointer to storage for virtualized global variables.  Expose to userspace
+ * as required for libkvm.
  */
 #if defined(_KERNEL) || defined(_WANT_VNET)
+#include <sys/queue.h>
+
+struct vnet {
+	LIST_ENTRY(vnet)	 vnet_le;	/* all vnets list */
+	u_int			 vnet_magic_n;
+	u_int			 vnet_ifcnt;
+	u_int			 vnet_sockcnt;
+	void			*vnet_data_mem;
+	uintptr_t		 vnet_data_base;
+};
+#define	VNET_MAGIC_N	0x3e0d8f29
+
+/*
+ * These two virtual network stack allocator definitions are also required
+ * for libkvm so that it can evaluate virtualized global variables.
+ */
 #define	VNET_SETNAME		"set_vnet"
 #define	VNET_SYMPREFIX		"vnet_entry_"
 #endif
 
 #ifdef _KERNEL
+
 #ifdef VIMAGE
+#include <sys/lock.h>
+#include <sys/proc.h>			/* for struct thread */
+#include <sys/rwlock.h>
+#include <sys/sx.h>
+
+/*
+ * Functions to allocate and destroy virtual network stacks.
+ */
+struct vnet *vnet_alloc(void);
+void	vnet_destroy(struct vnet *vnet);
+
+/*
+ * The current virtual network stack -- we may wish to move this to struct
+ * pcpu in the future.
+ */
+#define	curvnet	curthread->td_vnet
+
+/*
+ * Various macros -- get and set the current network stack, but also
+ * assertions.
+ */
+#ifdef INVARIANTS
+#define	VNET_DEBUG
+#endif
+#ifdef VNET_DEBUG
+#define	VNET_ASSERT(condition)						\
+	if (!(condition)) {						\
+		printf("VNET_ASSERT @ %s:%d %s():\n",			\
+			__FILE__, __LINE__, __FUNCTION__);		\
+		panic(#condition);					\
+	}
 
+#define	CURVNET_SET_QUIET(arg)						\
+	VNET_ASSERT((arg)->vnet_magic_n == VNET_MAGIC_N);		\
+	struct vnet *saved_vnet = curvnet;				\
+	const char *saved_vnet_lpush = curthread->td_vnet_lpush;	\
+	curvnet = arg;							\
+	curthread->td_vnet_lpush = __FUNCTION__;
+ 
+#define	CURVNET_SET_VERBOSE(arg)					\
+	CURVNET_SET_QUIET(arg)						\
+	if (saved_vnet)							\
+		printf("CURVNET_SET(%p) in %s() on cpu %d, prev %p in %s()\n", \
+		       curvnet,	curthread->td_vnet_lpush, curcpu,	\
+		       saved_vnet, saved_vnet_lpush);
+
+#define	CURVNET_SET(arg)	CURVNET_SET_VERBOSE(arg)
+ 
+#define	CURVNET_RESTORE()						\
+	VNET_ASSERT(saved_vnet == NULL ||				\
+		    saved_vnet->vnet_magic_n == VNET_MAGIC_N);		\
+	curvnet = saved_vnet;						\
+	curthread->td_vnet_lpush = saved_vnet_lpush;
+#else /* !VNET_DEBUG */
+#define	VNET_ASSERT(condition)
+
+#define	CURVNET_SET(arg)						\
+	struct vnet *saved_vnet = curvnet;				\
+	curvnet = arg;	
+ 
+#define	CURVNET_SET_VERBOSE(arg)	CURVNET_SET(arg)
+#define	CURVNET_SET_QUIET(arg)		CURVNET_SET(arg)
+ 
+#define	CURVNET_RESTORE()						\
+	curvnet = saved_vnet;
+#endif /* VNET_DEBUG */
+
+extern struct vnet *vnet0;
+#define	IS_DEFAULT_VNET(arg)	((arg) == vnet0)
+
+#define	CRED_TO_VNET(cr)	(cr)->cr_prison->pr_vnet
+#define	TD_TO_VNET(td)		CRED_TO_VNET((td)->td_ucred)
+#define	P_TO_VNET(p)		CRED_TO_VNET((p)->p_ucred)
+
+/*
+ * Global linked list of all virtual network stacks, along with read locks to
+ * access it.  If a caller may sleep while accessing the list, it must use
+ * the sleepable lock macros.
+ */
+LIST_HEAD(vnet_list_head, vnet);
+extern struct vnet_list_head vnet_head;
+extern struct rwlock vnet_rwlock;
+extern struct sx vnet_sxlock;
+
+#define	VNET_LIST_RLOCK()		sx_slock(&vnet_sxlock)
+#define	VNET_LIST_RLOCK_NOSLEEP()	rw_rlock(&vnet_rwlock)
+#define	VNET_LIST_RUNLOCK()		sx_sunlock(&vnet_sxlock)
+#define	VNET_LIST_RUNLOCK_NOSLEEP()	rw_runlock(&vnet_rwlock)
+
+/*
+ * Iteration macros to walk the global list of virtual network stacks.
+ */
+#define	VNET_ITERATOR_DECL(arg)	struct vnet *arg
+#define	VNET_FOREACH(arg)	LIST_FOREACH((arg), &vnet_head, vnet_le)
+
+/*
+ * Virtual network stack memory allocator, which allows global variables to
+ * be automatically instantiated for each network stack instance.
+ */
 #if defined(__arm__)
 __asm__(".section " VNET_SETNAME ", \"aw\", %progbits");
 #else
@@ -193,6 +320,28 @@ void	vnet_deregister_sysuninit(void *arg);
 #else /* !VIMAGE */
 
 /*
+ * Various virtual network stack macros compile to no-ops without VIMAGE.
+ */
+#define	curvnet			NULL
+
+#define	VNET_ASSERT(condition)
+#define	CURVNET_SET(arg)
+#define	CURVNET_SET_QUIET(arg)
+#define	CURVNET_RESTORE()
+
+#define	VNET_LIST_RLOCK()
+#define	VNET_LIST_RLOCK_NOSLEEP()
+#define	VNET_LIST_RUNLOCK()
+#define	VNET_LIST_RUNLOCK_NOSLEEP()
+#define	VNET_ITERATOR_DECL(arg)
+#define	VNET_FOREACH(arg)
+
+#define	IS_DEFAULT_VNET(arg)	1
+#define	CRED_TO_VNET(cr)	NULL
+#define	TD_TO_VNET(td)		NULL
+#define	P_TO_VNET(p)		NULL
+
+/*
  * Versions of the VNET macros that compile to normal global variables and
  * standard sysctl definitions.
  */