xref: /freebsd/sys/net/vnet.h (revision 941e286383714ef25f1ffe9ba6ae5040afdd7060)
1 /*-
2  * Copyright (c) 2006-2009 University of Zagreb
3  * Copyright (c) 2006-2009 FreeBSD Foundation
4  * All rights reserved.
5  *
6  * This software was developed by the University of Zagreb and the
7  * FreeBSD Foundation under sponsorship by the Stichting NLnet and the
8  * FreeBSD Foundation.
9  *
10  * Copyright (c) 2009 Jeffrey Roberson <jeff@freebsd.org>
11  * Copyright (c) 2009 Robert N. M. Watson
12  * All rights reserved.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  * $FreeBSD$
36  */
37 
38 /*-
39  * This header file defines several sets of interfaces supporting virtualized
40  * network stacks:
41  *
42  * - Definition of 'struct vnet' and functions and macros to allocate/free/
43  *   manipulate it.
44  *
45  * - A virtual network stack memory allocator, which provides support for
46  *   virtualized global variables via a special linker set, set_vnet.
47  *
48  * - Virtualized sysinits/sysuninits, which allow constructors and
49  *   destructors to be run for each network stack subsystem as virtual
50  *   instances are created and destroyed.
51  *
52  * If VIMAGE isn't compiled into the kernel, virtualized global variables
53  * compile to normal global variables, and virtualized sysinits to regular
54  * sysinits.
55  */
56 
57 #ifndef _NET_VNET_H_
58 #define	_NET_VNET_H_
59 
60 /*
61  * struct vnet describes a virtualized network stack, and is primarily a
62  * pointer to storage for virtualized global variables.  Expose to userspace
63  * as required for libkvm.
64  */
65 #if defined(_KERNEL) || defined(_WANT_VNET)
66 #include <sys/queue.h>
67 
68 struct vnet {
69 	LIST_ENTRY(vnet)	 vnet_le;	/* all vnets list */
70 	u_int			 vnet_magic_n;
71 	u_int			 vnet_ifcnt;
72 	u_int			 vnet_sockcnt;
73 	void			*vnet_data_mem;
74 	uintptr_t		 vnet_data_base;
75 };
76 #define	VNET_MAGIC_N	0x3e0d8f29
77 
78 /*
79  * These two virtual network stack allocator definitions are also required
80  * for libkvm so that it can evaluate virtualized global variables.
81  */
82 #define	VNET_SETNAME		"set_vnet"
83 #define	VNET_SYMPREFIX		"vnet_entry_"
84 #endif
85 
86 #ifdef _KERNEL
87 
88 #ifdef VIMAGE
89 #include <sys/lock.h>
90 #include <sys/proc.h>			/* for struct thread */
91 #include <sys/rwlock.h>
92 #include <sys/sx.h>
93 
94 /*
95  * Functions to allocate and destroy virtual network stacks.
96  */
97 struct vnet *vnet_alloc(void);
98 void	vnet_destroy(struct vnet *vnet);
99 
100 /*
101  * The current virtual network stack -- we may wish to move this to struct
102  * pcpu in the future.
103  */
104 #define	curvnet	curthread->td_vnet
105 
106 /*
107  * Various macros -- get and set the current network stack, but also
108  * assertions.
109  */
110 #ifdef VNET_DEBUG
111 #define	VNET_ASSERT(condition)						\
112 	if (!(condition)) {						\
113 		printf("VNET_ASSERT @ %s:%d %s():\n",			\
114 			__FILE__, __LINE__, __FUNCTION__);		\
115 		panic(#condition);					\
116 	}
117 
118 #define	CURVNET_SET_QUIET(arg)						\
119 	VNET_ASSERT((arg)->vnet_magic_n == VNET_MAGIC_N);		\
120 	struct vnet *saved_vnet = curvnet;				\
121 	const char *saved_vnet_lpush = curthread->td_vnet_lpush;	\
122 	curvnet = arg;							\
123 	curthread->td_vnet_lpush = __FUNCTION__;
124 
125 #define	CURVNET_SET_VERBOSE(arg)					\
126 	CURVNET_SET_QUIET(arg)						\
127 	if (saved_vnet)							\
128 		printf("CURVNET_SET(%p) in %s() on cpu %d, prev %p in %s()\n", \
129 		       curvnet,	curthread->td_vnet_lpush, curcpu,	\
130 		       saved_vnet, saved_vnet_lpush);
131 
132 #define	CURVNET_SET(arg)	CURVNET_SET_VERBOSE(arg)
133 
134 #define	CURVNET_RESTORE()						\
135 	VNET_ASSERT(saved_vnet == NULL ||				\
136 		    saved_vnet->vnet_magic_n == VNET_MAGIC_N);		\
137 	curvnet = saved_vnet;						\
138 	curthread->td_vnet_lpush = saved_vnet_lpush;
139 #else /* !VNET_DEBUG */
140 #define	VNET_ASSERT(condition)
141 
142 #define	CURVNET_SET(arg)						\
143 	struct vnet *saved_vnet = curvnet;				\
144 	curvnet = arg;
145 
146 #define	CURVNET_SET_VERBOSE(arg)	CURVNET_SET(arg)
147 #define	CURVNET_SET_QUIET(arg)		CURVNET_SET(arg)
148 
149 #define	CURVNET_RESTORE()						\
150 	curvnet = saved_vnet;
151 #endif /* VNET_DEBUG */
152 
153 extern struct vnet *vnet0;
154 #define	IS_DEFAULT_VNET(arg)	((arg) == vnet0)
155 
156 #define	CRED_TO_VNET(cr)	(cr)->cr_prison->pr_vnet
157 #define	TD_TO_VNET(td)		CRED_TO_VNET((td)->td_ucred)
158 #define	P_TO_VNET(p)		CRED_TO_VNET((p)->p_ucred)
159 
160 /*
161  * Global linked list of all virtual network stacks, along with read locks to
162  * access it.  If a caller may sleep while accessing the list, it must use
163  * the sleepable lock macros.
164  */
165 LIST_HEAD(vnet_list_head, vnet);
166 extern struct vnet_list_head vnet_head;
167 extern struct rwlock vnet_rwlock;
168 extern struct sx vnet_sxlock;
169 
170 #define	VNET_LIST_RLOCK()		sx_slock(&vnet_sxlock)
171 #define	VNET_LIST_RLOCK_NOSLEEP()	rw_rlock(&vnet_rwlock)
172 #define	VNET_LIST_RUNLOCK()		sx_sunlock(&vnet_sxlock)
173 #define	VNET_LIST_RUNLOCK_NOSLEEP()	rw_runlock(&vnet_rwlock)
174 
175 /*
176  * Iteration macros to walk the global list of virtual network stacks.
177  */
178 #define	VNET_ITERATOR_DECL(arg)	struct vnet *arg
179 #define	VNET_FOREACH(arg)	LIST_FOREACH((arg), &vnet_head, vnet_le)
180 
181 /*
182  * Virtual network stack memory allocator, which allows global variables to
183  * be automatically instantiated for each network stack instance.
184  */
185 __asm__(
186 #if defined(__arm__)
187 	".section " VNET_SETNAME ", \"aw\", %progbits\n"
188 #else
189 	".section " VNET_SETNAME ", \"aw\", @progbits\n"
190 #endif
191 	"\t.p2align " __XSTRING(CACHE_LINE_SHIFT) "\n"
192 	"\t.previous");
193 
194 #define	VNET_NAME(n)		vnet_entry_##n
195 #define	VNET_DECLARE(t, n)	extern t VNET_NAME(n)
196 #define	VNET_DEFINE(t, n)	t VNET_NAME(n) __section(VNET_SETNAME) __used
197 #define	_VNET_PTR(b, n)		(__typeof(VNET_NAME(n))*)		\
198 				    ((b) + (uintptr_t)&VNET_NAME(n))
199 
200 #define	_VNET(b, n)		(*_VNET_PTR(b, n))
201 
202 /*
203  * Virtualized global variable accessor macros.
204  */
205 #define	VNET_VNET_PTR(vnet, n)		_VNET_PTR((vnet)->vnet_data_base, n)
206 #define	VNET_VNET(vnet, n)		(*VNET_VNET_PTR((vnet), n))
207 
208 #define	VNET_PTR(n)		VNET_VNET_PTR(curvnet, n)
209 #define	VNET(n)			VNET_VNET(curvnet, n)
210 
211 /*
212  * Virtual network stack allocator interfaces from the kernel linker.
213  */
214 void	*vnet_data_alloc(int size);
215 void	 vnet_data_copy(void *start, int size);
216 void	 vnet_data_free(void *start_arg, int size);
217 
218 /*
219  * Sysctl variants for vnet-virtualized global variables.  Include
220  * <sys/sysctl.h> to expose these definitions.
221  *
222  * Note: SYSCTL_PROC() handler functions will need to resolve pointer
223  * arguments themselves, if required.
224  */
225 #ifdef SYSCTL_OID
226 int	vnet_sysctl_handle_int(SYSCTL_HANDLER_ARGS);
227 int	vnet_sysctl_handle_opaque(SYSCTL_HANDLER_ARGS);
228 int	vnet_sysctl_handle_string(SYSCTL_HANDLER_ARGS);
229 int	vnet_sysctl_handle_uint(SYSCTL_HANDLER_ARGS);
230 
231 #define	SYSCTL_VNET_INT(parent, nbr, name, access, ptr, val, descr)	\
232 	SYSCTL_OID(parent, nbr, name,					\
233 	    CTLTYPE_INT|CTLFLAG_MPSAFE|CTLFLAG_VNET|(access),		\
234 	    ptr, val, vnet_sysctl_handle_int, "I", descr)
235 #define	SYSCTL_VNET_PROC(parent, nbr, name, access, ptr, arg, handler,	\
236 	    fmt, descr)							\
237 	SYSCTL_OID(parent, nbr, name, CTLFLAG_VNET|(access), ptr, arg, 	\
238 	    handler, fmt, descr)
239 #define	SYSCTL_VNET_STRING(parent, nbr, name, access, arg, len, descr)	\
240 	SYSCTL_OID(parent, nbr, name,					\
241 	    CTLTYPE_STRING|CTLFLAG_VNET|(access),			\
242 	    arg, len, vnet_sysctl_handle_string, "A", descr)
243 #define	SYSCTL_VNET_STRUCT(parent, nbr, name, access, ptr, type, descr)	\
244 	SYSCTL_OID(parent, nbr, name,					\
245 	    CTLTYPE_OPAQUE|CTLFLAG_VNET|(access), ptr,			\
246 	    sizeof(struct type), vnet_sysctl_handle_opaque, "S," #type,	\
247 	    descr)
248 #define	SYSCTL_VNET_UINT(parent, nbr, name, access, ptr, val, descr)	\
249 	SYSCTL_OID(parent, nbr, name,					\
250 	    CTLTYPE_UINT|CTLFLAG_MPSAFE|CTLFLAG_VNET|(access),		\
251 	    ptr, val, vnet_sysctl_handle_uint, "IU", descr)
252 #define	VNET_SYSCTL_ARG(req, arg1) do {					\
253 	if (arg1 != NULL)						\
254 		arg1 = (void *)(TD_TO_VNET((req)->td)->vnet_data_base +	\
255 		    (uintptr_t)(arg1));					\
256 } while (0)
257 #endif /* SYSCTL_OID */
258 
259 /*
260  * Virtual sysinit mechanism, allowing network stack components to declare
261  * startup and shutdown methods to be run when virtual network stack
262  * instances are created and destroyed.
263  */
264 #include <sys/kernel.h>
265 
266 /*
267  * SYSINIT/SYSUNINIT variants that provide per-vnet constructors and
268  * destructors.
269  */
270 struct vnet_sysinit {
271 	enum sysinit_sub_id	subsystem;
272 	enum sysinit_elem_order	order;
273 	sysinit_cfunc_t		func;
274 	const void		*arg;
275 	TAILQ_ENTRY(vnet_sysinit) link;
276 };
277 
278 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
279 	static struct vnet_sysinit ident ## _vnet_init = {		\
280 		subsystem,						\
281 		order,							\
282 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
283 		(arg)							\
284 	};								\
285 	SYSINIT(vnet_init_ ## ident, subsystem, order,			\
286 	    vnet_register_sysinit, &ident ## _vnet_init);		\
287 	SYSUNINIT(vnet_init_ ## ident, subsystem, order,		\
288 	    vnet_deregister_sysinit, &ident ## _vnet_init)
289 
290 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
291 	static struct vnet_sysinit ident ## _vnet_uninit = {		\
292 		subsystem,						\
293 		order,							\
294 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
295 		(arg)							\
296 	};								\
297 	SYSINIT(vnet_uninit_ ## ident, subsystem, order,		\
298 	    vnet_register_sysuninit, &ident ## _vnet_uninit);		\
299 	SYSUNINIT(vnet_uninit_ ## ident, subsystem, order,		\
300 	    vnet_deregister_sysuninit, &ident ## _vnet_uninit)
301 
302 /*
303  * Run per-vnet sysinits or sysuninits during vnet creation/destruction.
304  */
305 void	 vnet_sysinit(void);
306 void	 vnet_sysuninit(void);
307 
308 /*
309  * Interfaces for managing per-vnet constructors and destructors.
310  */
311 void	vnet_register_sysinit(void *arg);
312 void	vnet_register_sysuninit(void *arg);
313 void	vnet_deregister_sysinit(void *arg);
314 void	vnet_deregister_sysuninit(void *arg);
315 
316 #else /* !VIMAGE */
317 
318 /*
319  * Various virtual network stack macros compile to no-ops without VIMAGE.
320  */
321 #define	curvnet			NULL
322 
323 #define	VNET_ASSERT(condition)
324 #define	CURVNET_SET(arg)
325 #define	CURVNET_SET_QUIET(arg)
326 #define	CURVNET_RESTORE()
327 
328 #define	VNET_LIST_RLOCK()
329 #define	VNET_LIST_RLOCK_NOSLEEP()
330 #define	VNET_LIST_RUNLOCK()
331 #define	VNET_LIST_RUNLOCK_NOSLEEP()
332 #define	VNET_ITERATOR_DECL(arg)
333 #define	VNET_FOREACH(arg)
334 
335 #define	IS_DEFAULT_VNET(arg)	1
336 #define	CRED_TO_VNET(cr)	NULL
337 #define	TD_TO_VNET(td)		NULL
338 #define	P_TO_VNET(p)		NULL
339 
340 /*
341  * Versions of the VNET macros that compile to normal global variables and
342  * standard sysctl definitions.
343  */
344 #define	VNET_NAME(n)		n
345 #define	VNET_DECLARE(t, n)	extern t n
346 #define	VNET_DEFINE(t, n)	t n
347 #define	_VNET_PTR(b, n)		&VNET_NAME(n)
348 
349 /*
350  * Virtualized global variable accessor macros.
351  */
352 #define	VNET_VNET_PTR(vnet, n)		(&(n))
353 #define	VNET_VNET(vnet, n)		(n)
354 
355 #define	VNET_PTR(n)		(&(n))
356 #define	VNET(n)			(n)
357 
358 /*
359  * When VIMAGE isn't compiled into the kernel, virtaulized SYSCTLs simply
360  * become normal SYSCTLs.
361  */
362 #ifdef SYSCTL_OID
363 #define	SYSCTL_VNET_INT(parent, nbr, name, access, ptr, val, descr)	\
364 	SYSCTL_INT(parent, nbr, name, access, ptr, val, descr)
365 #define	SYSCTL_VNET_PROC(parent, nbr, name, access, ptr, arg, handler,	\
366 	    fmt, descr)							\
367 	SYSCTL_PROC(parent, nbr, name, access, ptr, arg, handler, fmt,	\
368 	    descr)
369 #define	SYSCTL_VNET_STRING(parent, nbr, name, access, arg, len, descr)	\
370 	SYSCTL_STRING(parent, nbr, name, access, arg, len, descr)
371 #define	SYSCTL_VNET_STRUCT(parent, nbr, name, access, ptr, type, descr)	\
372 	SYSCTL_STRUCT(parent, nbr, name, access, ptr, type, descr)
373 #define	SYSCTL_VNET_UINT(parent, nbr, name, access, ptr, val, descr)	\
374 	SYSCTL_UINT(parent, nbr, name, access, ptr, val, descr)
375 #define	VNET_SYSCTL_ARG(req, arg1)
376 #endif /* SYSCTL_OID */
377 
378 /*
379  * When VIMAGE isn't compiled into the kernel, VNET_SYSINIT/VNET_SYSUNINIT
380  * map into normal sysinits, which have the same ordering properties.
381  */
382 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
383 	SYSINIT(ident, subsystem, order, func, arg)
384 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
385 	SYSUNINIT(ident, subsystem, order, func, arg)
386 
387 #endif /* VIMAGE */
388 #endif /* _KERNEL */
389 
390 #endif /* !_NET_VNET_H_ */
391