xref: /freebsd/sys/net/vnet.h (revision d8b878873e7aa8df1972cc6a642804b17eb61087)
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  * Location of the kernel's 'set_vnet' linker set.
96  */
97 extern uintptr_t	*__start_set_vnet;
98 extern uintptr_t	*__stop_set_vnet;
99 
100 #define	VNET_START	(uintptr_t)&__start_set_vnet
101 #define	VNET_STOP	(uintptr_t)&__stop_set_vnet
102 
103 /*
104  * Functions to allocate and destroy virtual network stacks.
105  */
106 struct vnet *vnet_alloc(void);
107 void	vnet_destroy(struct vnet *vnet);
108 
109 /*
110  * The current virtual network stack -- we may wish to move this to struct
111  * pcpu in the future.
112  */
113 #define	curvnet	curthread->td_vnet
114 
115 /*
116  * Various macros -- get and set the current network stack, but also
117  * assertions.
118  */
119 #ifdef VNET_DEBUG
120 void vnet_log_recursion(struct vnet *, const char *, int);
121 
122 #define	VNET_ASSERT(condition)						\
123 	if (!(condition)) {						\
124 		printf("VNET_ASSERT @ %s:%d %s():\n",			\
125 			__FILE__, __LINE__, __FUNCTION__);		\
126 		panic(#condition);					\
127 	}
128 
129 #define	CURVNET_SET_QUIET(arg)						\
130 	VNET_ASSERT((arg)->vnet_magic_n == VNET_MAGIC_N);		\
131 	struct vnet *saved_vnet = curvnet;				\
132 	const char *saved_vnet_lpush = curthread->td_vnet_lpush;	\
133 	curvnet = arg;							\
134 	curthread->td_vnet_lpush = __FUNCTION__;
135 
136 #define	CURVNET_SET_VERBOSE(arg)					\
137 	CURVNET_SET_QUIET(arg)						\
138 	if (saved_vnet)							\
139 		vnet_log_recursion(saved_vnet, saved_vnet_lpush, __LINE__);
140 
141 #define	CURVNET_SET(arg)	CURVNET_SET_VERBOSE(arg)
142 
143 #define	CURVNET_RESTORE()						\
144 	VNET_ASSERT(saved_vnet == NULL ||				\
145 		    saved_vnet->vnet_magic_n == VNET_MAGIC_N);		\
146 	curvnet = saved_vnet;						\
147 	curthread->td_vnet_lpush = saved_vnet_lpush;
148 #else /* !VNET_DEBUG */
149 #define	VNET_ASSERT(condition)
150 
151 #define	CURVNET_SET(arg)						\
152 	struct vnet *saved_vnet = curvnet;				\
153 	curvnet = arg;
154 
155 #define	CURVNET_SET_VERBOSE(arg)	CURVNET_SET(arg)
156 #define	CURVNET_SET_QUIET(arg)		CURVNET_SET(arg)
157 
158 #define	CURVNET_RESTORE()						\
159 	curvnet = saved_vnet;
160 #endif /* VNET_DEBUG */
161 
162 extern struct vnet *vnet0;
163 #define	IS_DEFAULT_VNET(arg)	((arg) == vnet0)
164 
165 #define	CRED_TO_VNET(cr)	(cr)->cr_prison->pr_vnet
166 #define	TD_TO_VNET(td)		CRED_TO_VNET((td)->td_ucred)
167 #define	P_TO_VNET(p)		CRED_TO_VNET((p)->p_ucred)
168 
169 /*
170  * Global linked list of all virtual network stacks, along with read locks to
171  * access it.  If a caller may sleep while accessing the list, it must use
172  * the sleepable lock macros.
173  */
174 LIST_HEAD(vnet_list_head, vnet);
175 extern struct vnet_list_head vnet_head;
176 extern struct rwlock vnet_rwlock;
177 extern struct sx vnet_sxlock;
178 
179 #define	VNET_LIST_RLOCK()		sx_slock(&vnet_sxlock)
180 #define	VNET_LIST_RLOCK_NOSLEEP()	rw_rlock(&vnet_rwlock)
181 #define	VNET_LIST_RUNLOCK()		sx_sunlock(&vnet_sxlock)
182 #define	VNET_LIST_RUNLOCK_NOSLEEP()	rw_runlock(&vnet_rwlock)
183 
184 /*
185  * Iteration macros to walk the global list of virtual network stacks.
186  */
187 #define	VNET_ITERATOR_DECL(arg)	struct vnet *arg
188 #define	VNET_FOREACH(arg)	LIST_FOREACH((arg), &vnet_head, vnet_le)
189 
190 /*
191  * Virtual network stack memory allocator, which allows global variables to
192  * be automatically instantiated for each network stack instance.
193  */
194 __asm__(
195 #if defined(__arm__)
196 	".section " VNET_SETNAME ", \"aw\", %progbits\n"
197 #else
198 	".section " VNET_SETNAME ", \"aw\", @progbits\n"
199 #endif
200 	"\t.p2align " __XSTRING(CACHE_LINE_SHIFT) "\n"
201 	"\t.previous");
202 
203 #define	VNET_NAME(n)		vnet_entry_##n
204 #define	VNET_DECLARE(t, n)	extern t VNET_NAME(n)
205 #define	VNET_DEFINE(t, n)	t VNET_NAME(n) __section(VNET_SETNAME) __used
206 #define	_VNET_PTR(b, n)		(__typeof(VNET_NAME(n))*)		\
207 				    ((b) + (uintptr_t)&VNET_NAME(n))
208 
209 #define	_VNET(b, n)		(*_VNET_PTR(b, n))
210 
211 /*
212  * Virtualized global variable accessor macros.
213  */
214 #define	VNET_VNET_PTR(vnet, n)		_VNET_PTR((vnet)->vnet_data_base, n)
215 #define	VNET_VNET(vnet, n)		(*VNET_VNET_PTR((vnet), n))
216 
217 #define	VNET_PTR(n)		VNET_VNET_PTR(curvnet, n)
218 #define	VNET(n)			VNET_VNET(curvnet, n)
219 
220 /*
221  * Virtual network stack allocator interfaces from the kernel linker.
222  */
223 void	*vnet_data_alloc(int size);
224 void	 vnet_data_copy(void *start, int size);
225 void	 vnet_data_free(void *start_arg, int size);
226 
227 /*
228  * Sysctl variants for vnet-virtualized global variables.  Include
229  * <sys/sysctl.h> to expose these definitions.
230  *
231  * Note: SYSCTL_PROC() handler functions will need to resolve pointer
232  * arguments themselves, if required.
233  */
234 #ifdef SYSCTL_OID
235 int	vnet_sysctl_handle_int(SYSCTL_HANDLER_ARGS);
236 int	vnet_sysctl_handle_opaque(SYSCTL_HANDLER_ARGS);
237 int	vnet_sysctl_handle_string(SYSCTL_HANDLER_ARGS);
238 int	vnet_sysctl_handle_uint(SYSCTL_HANDLER_ARGS);
239 
240 #define	SYSCTL_VNET_INT(parent, nbr, name, access, ptr, val, descr)	\
241 	SYSCTL_OID(parent, nbr, name,					\
242 	    CTLTYPE_INT|CTLFLAG_MPSAFE|CTLFLAG_VNET|(access),		\
243 	    ptr, val, vnet_sysctl_handle_int, "I", descr)
244 #define	SYSCTL_VNET_PROC(parent, nbr, name, access, ptr, arg, handler,	\
245 	    fmt, descr)							\
246 	SYSCTL_OID(parent, nbr, name, CTLFLAG_VNET|(access), ptr, arg, 	\
247 	    handler, fmt, descr)
248 #define	SYSCTL_VNET_STRING(parent, nbr, name, access, arg, len, descr)	\
249 	SYSCTL_OID(parent, nbr, name,					\
250 	    CTLTYPE_STRING|CTLFLAG_VNET|(access),			\
251 	    arg, len, vnet_sysctl_handle_string, "A", descr)
252 #define	SYSCTL_VNET_STRUCT(parent, nbr, name, access, ptr, type, descr)	\
253 	SYSCTL_OID(parent, nbr, name,					\
254 	    CTLTYPE_OPAQUE|CTLFLAG_VNET|(access), ptr,			\
255 	    sizeof(struct type), vnet_sysctl_handle_opaque, "S," #type,	\
256 	    descr)
257 #define	SYSCTL_VNET_UINT(parent, nbr, name, access, ptr, val, descr)	\
258 	SYSCTL_OID(parent, nbr, name,					\
259 	    CTLTYPE_UINT|CTLFLAG_MPSAFE|CTLFLAG_VNET|(access),		\
260 	    ptr, val, vnet_sysctl_handle_uint, "IU", descr)
261 #define	VNET_SYSCTL_ARG(req, arg1) do {					\
262 	if (arg1 != NULL)						\
263 		arg1 = (void *)(TD_TO_VNET((req)->td)->vnet_data_base +	\
264 		    (uintptr_t)(arg1));					\
265 } while (0)
266 #endif /* SYSCTL_OID */
267 
268 /*
269  * Virtual sysinit mechanism, allowing network stack components to declare
270  * startup and shutdown methods to be run when virtual network stack
271  * instances are created and destroyed.
272  */
273 #include <sys/kernel.h>
274 
275 /*
276  * SYSINIT/SYSUNINIT variants that provide per-vnet constructors and
277  * destructors.
278  */
279 struct vnet_sysinit {
280 	enum sysinit_sub_id	subsystem;
281 	enum sysinit_elem_order	order;
282 	sysinit_cfunc_t		func;
283 	const void		*arg;
284 	TAILQ_ENTRY(vnet_sysinit) link;
285 };
286 
287 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
288 	static struct vnet_sysinit ident ## _vnet_init = {		\
289 		subsystem,						\
290 		order,							\
291 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
292 		(arg)							\
293 	};								\
294 	SYSINIT(vnet_init_ ## ident, subsystem, order,			\
295 	    vnet_register_sysinit, &ident ## _vnet_init);		\
296 	SYSUNINIT(vnet_init_ ## ident, subsystem, order,		\
297 	    vnet_deregister_sysinit, &ident ## _vnet_init)
298 
299 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
300 	static struct vnet_sysinit ident ## _vnet_uninit = {		\
301 		subsystem,						\
302 		order,							\
303 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
304 		(arg)							\
305 	};								\
306 	SYSINIT(vnet_uninit_ ## ident, subsystem, order,		\
307 	    vnet_register_sysuninit, &ident ## _vnet_uninit);		\
308 	SYSUNINIT(vnet_uninit_ ## ident, subsystem, order,		\
309 	    vnet_deregister_sysuninit, &ident ## _vnet_uninit)
310 
311 /*
312  * Run per-vnet sysinits or sysuninits during vnet creation/destruction.
313  */
314 void	 vnet_sysinit(void);
315 void	 vnet_sysuninit(void);
316 
317 /*
318  * Interfaces for managing per-vnet constructors and destructors.
319  */
320 void	vnet_register_sysinit(void *arg);
321 void	vnet_register_sysuninit(void *arg);
322 void	vnet_deregister_sysinit(void *arg);
323 void	vnet_deregister_sysuninit(void *arg);
324 
325 /*
326  * EVENTHANDLER(9) extensions.
327  */
328 #include <sys/eventhandler.h>
329 
330 void	vnet_global_eventhandler_iterator_func(void *, ...);
331 #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
332 do {									\
333 	if (IS_DEFAULT_VNET(curvnet)) {					\
334 		(tag) = vimage_eventhandler_register(NULL, #name, func,	\
335 		    arg, priority,					\
336 		    vnet_global_eventhandler_iterator_func);		\
337 	}								\
338 } while(0)
339 #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)	\
340 do {									\
341 	if (IS_DEFAULT_VNET(curvnet)) {					\
342 		vimage_eventhandler_register(NULL, #name, func,		\
343 		    arg, priority,					\
344 		    vnet_global_eventhandler_iterator_func);		\
345 	}								\
346 } while(0)
347 
348 #else /* !VIMAGE */
349 
350 /*
351  * Various virtual network stack macros compile to no-ops without VIMAGE.
352  */
353 #define	curvnet			NULL
354 
355 #define	VNET_ASSERT(condition)
356 #define	CURVNET_SET(arg)
357 #define	CURVNET_SET_QUIET(arg)
358 #define	CURVNET_RESTORE()
359 
360 #define	VNET_LIST_RLOCK()
361 #define	VNET_LIST_RLOCK_NOSLEEP()
362 #define	VNET_LIST_RUNLOCK()
363 #define	VNET_LIST_RUNLOCK_NOSLEEP()
364 #define	VNET_ITERATOR_DECL(arg)
365 #define	VNET_FOREACH(arg)
366 
367 #define	IS_DEFAULT_VNET(arg)	1
368 #define	CRED_TO_VNET(cr)	NULL
369 #define	TD_TO_VNET(td)		NULL
370 #define	P_TO_VNET(p)		NULL
371 
372 /*
373  * Versions of the VNET macros that compile to normal global variables and
374  * standard sysctl definitions.
375  */
376 #define	VNET_NAME(n)		n
377 #define	VNET_DECLARE(t, n)	extern t n
378 #define	VNET_DEFINE(t, n)	t n
379 #define	_VNET_PTR(b, n)		&VNET_NAME(n)
380 
381 /*
382  * Virtualized global variable accessor macros.
383  */
384 #define	VNET_VNET_PTR(vnet, n)		(&(n))
385 #define	VNET_VNET(vnet, n)		(n)
386 
387 #define	VNET_PTR(n)		(&(n))
388 #define	VNET(n)			(n)
389 
390 /*
391  * When VIMAGE isn't compiled into the kernel, virtaulized SYSCTLs simply
392  * become normal SYSCTLs.
393  */
394 #ifdef SYSCTL_OID
395 #define	SYSCTL_VNET_INT(parent, nbr, name, access, ptr, val, descr)	\
396 	SYSCTL_INT(parent, nbr, name, access, ptr, val, descr)
397 #define	SYSCTL_VNET_PROC(parent, nbr, name, access, ptr, arg, handler,	\
398 	    fmt, descr)							\
399 	SYSCTL_PROC(parent, nbr, name, access, ptr, arg, handler, fmt,	\
400 	    descr)
401 #define	SYSCTL_VNET_STRING(parent, nbr, name, access, arg, len, descr)	\
402 	SYSCTL_STRING(parent, nbr, name, access, arg, len, descr)
403 #define	SYSCTL_VNET_STRUCT(parent, nbr, name, access, ptr, type, descr)	\
404 	SYSCTL_STRUCT(parent, nbr, name, access, ptr, type, descr)
405 #define	SYSCTL_VNET_UINT(parent, nbr, name, access, ptr, val, descr)	\
406 	SYSCTL_UINT(parent, nbr, name, access, ptr, val, descr)
407 #define	VNET_SYSCTL_ARG(req, arg1)
408 #endif /* SYSCTL_OID */
409 
410 /*
411  * When VIMAGE isn't compiled into the kernel, VNET_SYSINIT/VNET_SYSUNINIT
412  * map into normal sysinits, which have the same ordering properties.
413  */
414 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
415 	SYSINIT(ident, subsystem, order, func, arg)
416 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
417 	SYSUNINIT(ident, subsystem, order, func, arg)
418 
419 /*
420  * Without VIMAGE revert to the default implementation.
421  */
422 #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
423 	(tag) = eventhandler_register(NULL, #name, func, arg, priority)
424 #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)	\
425 	eventhandler_register(NULL, #name, func, arg, priority)
426 #endif /* VIMAGE */
427 #endif /* _KERNEL */
428 
429 #endif /* !_NET_VNET_H_ */
430