Major overhaul of pseudo-interface cloning. Highlights include:

 - Split the code out into if_clone.[ch].
 - Locked struct if_clone. [1]
 - Add a per-cloner match function rather then simply matching names of
   the form <name><unit> and <name>.
 - Use the match function to allow creation of <interface>.<tag>
   vlan interfaces.  The old way is preserved unchanged!
 - Also the match function to allow creation of stf(4) interfaces named
   stf0, stf, or 6to4.  This is the only major user visible change in
   that "ifconfig stf" creates the interface stf rather then stf0 and
   does not print "stf0" to stdout.
 - Allow destroy functions to fail so they can refuse to delete
   interfaces.  Currently, we forbid the deletion of interfaces which
   were created in the init function, particularly lo0, pflog0, and
   pfsync0.  In the case of lo0 this was a panic implementation so it
   does not count as a user visiable change. :-)
 - Since most interfaces do not need the new functionality, an family of
   wrapper functions, ifc_simple_*(), were created to wrap old style
   cloner functions.
 - The IF_CLONE_INITIALIZER macro is replaced with a new incompatible
   IFC_CLONE_INITIALIZER and ifc_simple consumers use IFC_SIMPLE_DECLARE
   instead.

Submitted by:   Maurycy Pawlowski-Wieronski <maurycy at fouk.org> [1]
Reviewed by:    andre, mlaier
Discussed on:	net

1 files changed, 113 insertions, 0 deletions

diff --git a/sys/net/if_clone.h b/sys/net/if_clone.h
new file mode 100644
index 0000000..61f1f1f
--- /dev/null
+++ b/sys/net/if_clone.h
@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 1982, 1986, 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	From: @(#)if.h	8.1 (Berkeley) 6/10/93
+ * $FreeBSD$
+ */
+
+#ifndef	_NET_IF_CLONE_H_
+#define	_NET_IF_CLONE_H_
+
+#ifdef _KERNEL
+
+#define IFC_CLONE_INITIALIZER(name, data, maxunit,			\
+    attach, match, create, destroy)					\
+    { { 0 }, name, maxunit, NULL, 0, data, attach, match, create, destroy }
+
+/*
+ * Structure describing a `cloning' interface.
+ *
+ * List of locks
+ * (c)		const until freeing
+ * (d)		driver specific data, may need external protection.
+ * (e)		locked by if_cloners_mtx
+ * (i)		locked by ifc_mtx mtx
+ */
+struct if_clone {
+	LIST_ENTRY(if_clone) ifc_list;	/* (e) On list of cloners */
+	const char *ifc_name;		/* (c) Name of device, e.g. `gif' */
+	int ifc_maxunit;		/* (c) Maximum unit number */
+	unsigned char *ifc_units;	/* (i) Bitmap to handle units. */
+					/*     Considered private, access */
+					/*     via ifc_(alloc|free)_unit(). */
+	int ifc_bmlen;			/* (c) Bitmap length. */
+	void *ifc_data;			/* (*) Data for ifc_* functions. */
+
+	/* (c) Driver specific cloning functions.  Called with no locks held. */
+	void	(*ifc_attach)(struct if_clone *);
+	int	(*ifc_match)(struct if_clone *, const char *);
+	int	(*ifc_create)(struct if_clone *, char *, size_t);
+	int	(*ifc_destroy)(struct if_clone *, struct ifnet *);
+
+	long ifc_refcnt;		/* (i) Refrence count. */
+	struct mtx ifc_mtx;		/* Muted to protect members. */
+};
+
+void	if_clone_init(void);
+void	if_clone_attach(struct if_clone *);
+void	if_clone_detach(struct if_clone *);
+
+int	if_clone_create(char *, size_t);
+int	if_clone_destroy(const char *);
+int	if_clone_list(struct if_clonereq *);
+
+int	ifc_name2unit(const char *name, int *unit);
+int	ifc_alloc_unit(struct if_clone *, int *);
+void	ifc_free_unit(struct if_clone *, int);
+
+/*
+ * The ifc_simple functions, structures, and macros implement basic
+ * cloning as in 5.[012].
+ */
+
+struct ifc_simple_data {
+	int ifcs_minifs;		/* minimum number of interfaces */
+
+	int	(*ifcs_create)(struct if_clone *, int);
+	void	(*ifcs_destroy)(struct ifnet *);
+};
+
+/* interface clone event */
+typedef void (*if_clone_event_handler_t)(void *, struct if_clone *);
+EVENTHANDLER_DECLARE(if_clone_event, if_clone_event_handler_t);
+
+#define IFC_SIMPLE_DECLARE(name, minifs)				\
+struct ifc_simple_data name##_cloner_data =				\
+    {minifs, name##_clone_create, name##_clone_destroy};		\
+struct if_clone name##_cloner =						\
+    IFC_CLONE_INITIALIZER(#name, &name##_cloner_data, IF_MAXUNIT,	\
+    ifc_simple_attach, ifc_simple_match, ifc_simple_create, ifc_simple_destroy)
+
+void	ifc_simple_attach(struct if_clone *);
+int	ifc_simple_match(struct if_clone *, const char *);
+int	ifc_simple_create(struct if_clone *, char *, size_t);
+int	ifc_simple_destroy(struct if_clone *, struct ifnet *);
+
+#endif /* _KERNEL */
+
+#endif /* !_NET_IF_CLONE_H_ */