xref: /freebsd/sys/net/vnet.h (revision 0f27aaf940f2fa5a6540285537b33115a96161a4)
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 __GLOBL(__start_set_vnet);
99 extern uintptr_t	*__stop_set_vnet;
100 __GLOBL(__stop_set_vnet);
101 
102 #define	VNET_START	(uintptr_t)&__start_set_vnet
103 #define	VNET_STOP	(uintptr_t)&__stop_set_vnet
104 
105 /*
106  * Functions to allocate and destroy virtual network stacks.
107  */
108 struct vnet *vnet_alloc(void);
109 void	vnet_destroy(struct vnet *vnet);
110 
111 /*
112  * The current virtual network stack -- we may wish to move this to struct
113  * pcpu in the future.
114  */
115 #define	curvnet	curthread->td_vnet
116 
117 /*
118  * Various macros -- get and set the current network stack, but also
119  * assertions.
120  */
121 #ifdef VNET_DEBUG
122 void vnet_log_recursion(struct vnet *, const char *, int);
123 
124 #define	VNET_ASSERT(condition)						\
125 	if (!(condition)) {						\
126 		printf("VNET_ASSERT @ %s:%d %s():\n",			\
127 			__FILE__, __LINE__, __FUNCTION__);		\
128 		panic(#condition);					\
129 	}
130 
131 #define	CURVNET_SET_QUIET(arg)						\
132 	VNET_ASSERT((arg)->vnet_magic_n == VNET_MAGIC_N);		\
133 	struct vnet *saved_vnet = curvnet;				\
134 	const char *saved_vnet_lpush = curthread->td_vnet_lpush;	\
135 	curvnet = arg;							\
136 	curthread->td_vnet_lpush = __FUNCTION__;
137 
138 #define	CURVNET_SET_VERBOSE(arg)					\
139 	CURVNET_SET_QUIET(arg)						\
140 	if (saved_vnet)							\
141 		vnet_log_recursion(saved_vnet, saved_vnet_lpush, __LINE__);
142 
143 #define	CURVNET_SET(arg)	CURVNET_SET_VERBOSE(arg)
144 
145 #define	CURVNET_RESTORE()						\
146 	VNET_ASSERT(saved_vnet == NULL ||				\
147 		    saved_vnet->vnet_magic_n == VNET_MAGIC_N);		\
148 	curvnet = saved_vnet;						\
149 	curthread->td_vnet_lpush = saved_vnet_lpush;
150 #else /* !VNET_DEBUG */
151 #define	VNET_ASSERT(condition)
152 
153 #define	CURVNET_SET(arg)						\
154 	struct vnet *saved_vnet = curvnet;				\
155 	curvnet = arg;
156 
157 #define	CURVNET_SET_VERBOSE(arg)	CURVNET_SET(arg)
158 #define	CURVNET_SET_QUIET(arg)		CURVNET_SET(arg)
159 
160 #define	CURVNET_RESTORE()						\
161 	curvnet = saved_vnet;
162 #endif /* VNET_DEBUG */
163 
164 extern struct vnet *vnet0;
165 #define	IS_DEFAULT_VNET(arg)	((arg) == vnet0)
166 
167 #define	CRED_TO_VNET(cr)	(cr)->cr_prison->pr_vnet
168 #define	TD_TO_VNET(td)		CRED_TO_VNET((td)->td_ucred)
169 #define	P_TO_VNET(p)		CRED_TO_VNET((p)->p_ucred)
170 
171 /*
172  * Global linked list of all virtual network stacks, along with read locks to
173  * access it.  If a caller may sleep while accessing the list, it must use
174  * the sleepable lock macros.
175  */
176 LIST_HEAD(vnet_list_head, vnet);
177 extern struct vnet_list_head vnet_head;
178 extern struct rwlock vnet_rwlock;
179 extern struct sx vnet_sxlock;
180 
181 #define	VNET_LIST_RLOCK()		sx_slock(&vnet_sxlock)
182 #define	VNET_LIST_RLOCK_NOSLEEP()	rw_rlock(&vnet_rwlock)
183 #define	VNET_LIST_RUNLOCK()		sx_sunlock(&vnet_sxlock)
184 #define	VNET_LIST_RUNLOCK_NOSLEEP()	rw_runlock(&vnet_rwlock)
185 
186 /*
187  * Iteration macros to walk the global list of virtual network stacks.
188  */
189 #define	VNET_ITERATOR_DECL(arg)	struct vnet *arg
190 #define	VNET_FOREACH(arg)	LIST_FOREACH((arg), &vnet_head, vnet_le)
191 
192 /*
193  * Virtual network stack memory allocator, which allows global variables to
194  * be automatically instantiated for each network stack instance.
195  */
196 #define	VNET_NAME(n)		vnet_entry_##n
197 #define	VNET_DECLARE(t, n)	extern t VNET_NAME(n)
198 #define	VNET_DEFINE(t, n)	t VNET_NAME(n) __section(VNET_SETNAME) __used
199 #define	_VNET_PTR(b, n)		(__typeof(VNET_NAME(n))*)		\
200 				    ((b) + (uintptr_t)&VNET_NAME(n))
201 
202 #define	_VNET(b, n)		(*_VNET_PTR(b, n))
203 
204 /*
205  * Virtualized global variable accessor macros.
206  */
207 #define	VNET_VNET_PTR(vnet, n)		_VNET_PTR((vnet)->vnet_data_base, n)
208 #define	VNET_VNET(vnet, n)		(*VNET_VNET_PTR((vnet), n))
209 
210 #define	VNET_PTR(n)		VNET_VNET_PTR(curvnet, n)
211 #define	VNET(n)			VNET_VNET(curvnet, n)
212 
213 /*
214  * Virtual network stack allocator interfaces from the kernel linker.
215  */
216 void	*vnet_data_alloc(int size);
217 void	 vnet_data_copy(void *start, int size);
218 void	 vnet_data_free(void *start_arg, int size);
219 
220 /*
221  * Sysctl variants for vnet-virtualized global variables.  Include
222  * <sys/sysctl.h> to expose these definitions.
223  *
224  * Note: SYSCTL_PROC() handler functions will need to resolve pointer
225  * arguments themselves, if required.
226  */
227 #ifdef SYSCTL_OID
228 int	vnet_sysctl_handle_int(SYSCTL_HANDLER_ARGS);
229 int	vnet_sysctl_handle_opaque(SYSCTL_HANDLER_ARGS);
230 int	vnet_sysctl_handle_string(SYSCTL_HANDLER_ARGS);
231 int	vnet_sysctl_handle_uint(SYSCTL_HANDLER_ARGS);
232 
233 #define	SYSCTL_VNET_INT(parent, nbr, name, access, ptr, val, descr)	\
234 	SYSCTL_OID(parent, nbr, name,					\
235 	    CTLTYPE_INT|CTLFLAG_MPSAFE|CTLFLAG_VNET|(access),		\
236 	    ptr, val, vnet_sysctl_handle_int, "I", descr)
237 #define	SYSCTL_VNET_PROC(parent, nbr, name, access, ptr, arg, handler,	\
238 	    fmt, descr)							\
239 	CTASSERT(((access) & CTLTYPE) != 0);				\
240 	SYSCTL_OID(parent, nbr, name, CTLFLAG_VNET|(access), ptr, arg, 	\
241 	    handler, fmt, descr)
242 #define	SYSCTL_VNET_OPAQUE(parent, nbr, name, access, ptr, len, fmt,    \
243 	    descr)							\
244 	SYSCTL_OID(parent, nbr, name,					\
245 	    CTLTYPE_OPAQUE|CTLFLAG_VNET|(access), ptr, len, 		\
246 	    vnet_sysctl_handle_opaque, fmt, descr)
247 #define	SYSCTL_VNET_STRING(parent, nbr, name, access, arg, len, descr)	\
248 	SYSCTL_OID(parent, nbr, name,					\
249 	    CTLTYPE_STRING|CTLFLAG_VNET|(access),			\
250 	    arg, len, vnet_sysctl_handle_string, "A", descr)
251 #define	SYSCTL_VNET_STRUCT(parent, nbr, name, access, ptr, type, descr)	\
252 	SYSCTL_OID(parent, nbr, name,					\
253 	    CTLTYPE_OPAQUE|CTLFLAG_VNET|(access), ptr,			\
254 	    sizeof(struct type), vnet_sysctl_handle_opaque, "S," #type,	\
255 	    descr)
256 #define	SYSCTL_VNET_UINT(parent, nbr, name, access, ptr, val, descr)	\
257 	SYSCTL_OID(parent, nbr, name,					\
258 	    CTLTYPE_UINT|CTLFLAG_MPSAFE|CTLFLAG_VNET|(access),		\
259 	    ptr, val, vnet_sysctl_handle_uint, "IU", descr)
260 #define	VNET_SYSCTL_ARG(req, arg1) do {					\
261 	if (arg1 != NULL)						\
262 		arg1 = (void *)(TD_TO_VNET((req)->td)->vnet_data_base +	\
263 		    (uintptr_t)(arg1));					\
264 } while (0)
265 #endif /* SYSCTL_OID */
266 
267 /*
268  * Virtual sysinit mechanism, allowing network stack components to declare
269  * startup and shutdown methods to be run when virtual network stack
270  * instances are created and destroyed.
271  */
272 #include <sys/kernel.h>
273 
274 /*
275  * SYSINIT/SYSUNINIT variants that provide per-vnet constructors and
276  * destructors.
277  */
278 struct vnet_sysinit {
279 	enum sysinit_sub_id	subsystem;
280 	enum sysinit_elem_order	order;
281 	sysinit_cfunc_t		func;
282 	const void		*arg;
283 	TAILQ_ENTRY(vnet_sysinit) link;
284 };
285 
286 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
287 	static struct vnet_sysinit ident ## _vnet_init = {		\
288 		subsystem,						\
289 		order,							\
290 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
291 		(arg)							\
292 	};								\
293 	SYSINIT(vnet_init_ ## ident, subsystem, order,			\
294 	    vnet_register_sysinit, &ident ## _vnet_init);		\
295 	SYSUNINIT(vnet_init_ ## ident, subsystem, order,		\
296 	    vnet_deregister_sysinit, &ident ## _vnet_init)
297 
298 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
299 	static struct vnet_sysinit ident ## _vnet_uninit = {		\
300 		subsystem,						\
301 		order,							\
302 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
303 		(arg)							\
304 	};								\
305 	SYSINIT(vnet_uninit_ ## ident, subsystem, order,		\
306 	    vnet_register_sysuninit, &ident ## _vnet_uninit);		\
307 	SYSUNINIT(vnet_uninit_ ## ident, subsystem, order,		\
308 	    vnet_deregister_sysuninit, &ident ## _vnet_uninit)
309 
310 /*
311  * Run per-vnet sysinits or sysuninits during vnet creation/destruction.
312  */
313 void	 vnet_sysinit(void);
314 void	 vnet_sysuninit(void);
315 
316 /*
317  * Interfaces for managing per-vnet constructors and destructors.
318  */
319 void	vnet_register_sysinit(void *arg);
320 void	vnet_register_sysuninit(void *arg);
321 void	vnet_deregister_sysinit(void *arg);
322 void	vnet_deregister_sysuninit(void *arg);
323 
324 /*
325  * EVENTHANDLER(9) extensions.
326  */
327 #include <sys/eventhandler.h>
328 
329 void	vnet_global_eventhandler_iterator_func(void *, ...);
330 #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
331 do {									\
332 	if (IS_DEFAULT_VNET(curvnet)) {					\
333 		(tag) = vimage_eventhandler_register(NULL, #name, func,	\
334 		    arg, priority,					\
335 		    vnet_global_eventhandler_iterator_func);		\
336 	}								\
337 } while(0)
338 #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)	\
339 do {									\
340 	if (IS_DEFAULT_VNET(curvnet)) {					\
341 		vimage_eventhandler_register(NULL, #name, func,		\
342 		    arg, priority,					\
343 		    vnet_global_eventhandler_iterator_func);		\
344 	}								\
345 } while(0)
346 
347 #else /* !VIMAGE */
348 
349 /*
350  * Various virtual network stack macros compile to no-ops without VIMAGE.
351  */
352 #define	curvnet			NULL
353 
354 #define	VNET_ASSERT(condition)
355 #define	CURVNET_SET(arg)
356 #define	CURVNET_SET_QUIET(arg)
357 #define	CURVNET_RESTORE()
358 
359 #define	VNET_LIST_RLOCK()
360 #define	VNET_LIST_RLOCK_NOSLEEP()
361 #define	VNET_LIST_RUNLOCK()
362 #define	VNET_LIST_RUNLOCK_NOSLEEP()
363 #define	VNET_ITERATOR_DECL(arg)
364 #define	VNET_FOREACH(arg)
365 
366 #define	IS_DEFAULT_VNET(arg)	1
367 #define	CRED_TO_VNET(cr)	NULL
368 #define	TD_TO_VNET(td)		NULL
369 #define	P_TO_VNET(p)		NULL
370 
371 /*
372  * Versions of the VNET macros that compile to normal global variables and
373  * standard sysctl definitions.
374  */
375 #define	VNET_NAME(n)		n
376 #define	VNET_DECLARE(t, n)	extern t n
377 #define	VNET_DEFINE(t, n)	t n
378 #define	_VNET_PTR(b, n)		&VNET_NAME(n)
379 
380 /*
381  * Virtualized global variable accessor macros.
382  */
383 #define	VNET_VNET_PTR(vnet, n)		(&(n))
384 #define	VNET_VNET(vnet, n)		(n)
385 
386 #define	VNET_PTR(n)		(&(n))
387 #define	VNET(n)			(n)
388 
389 /*
390  * When VIMAGE isn't compiled into the kernel, virtaulized SYSCTLs simply
391  * become normal SYSCTLs.
392  */
393 #ifdef SYSCTL_OID
394 #define	SYSCTL_VNET_INT(parent, nbr, name, access, ptr, val, descr)	\
395 	SYSCTL_INT(parent, nbr, name, access, ptr, val, descr)
396 #define	SYSCTL_VNET_PROC(parent, nbr, name, access, ptr, arg, handler,	\
397 	    fmt, descr)							\
398 	SYSCTL_PROC(parent, nbr, name, access, ptr, arg, handler, fmt,	\
399 	    descr)
400 #define	SYSCTL_VNET_OPAQUE(parent, nbr, name, access, ptr, len, fmt,    \
401 	    descr)							\
402 	SYSCTL_OPAQUE(parent, nbr, name, access, ptr, len, fmt, descr)
403 #define	SYSCTL_VNET_STRING(parent, nbr, name, access, arg, len, descr)	\
404 	SYSCTL_STRING(parent, nbr, name, access, arg, len, descr)
405 #define	SYSCTL_VNET_STRUCT(parent, nbr, name, access, ptr, type, descr)	\
406 	SYSCTL_STRUCT(parent, nbr, name, access, ptr, type, descr)
407 #define	SYSCTL_VNET_UINT(parent, nbr, name, access, ptr, val, descr)	\
408 	SYSCTL_UINT(parent, nbr, name, access, ptr, val, descr)
409 #define	VNET_SYSCTL_ARG(req, arg1)
410 #endif /* SYSCTL_OID */
411 
412 /*
413  * When VIMAGE isn't compiled into the kernel, VNET_SYSINIT/VNET_SYSUNINIT
414  * map into normal sysinits, which have the same ordering properties.
415  */
416 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
417 	SYSINIT(ident, subsystem, order, func, arg)
418 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
419 	SYSUNINIT(ident, subsystem, order, func, arg)
420 
421 /*
422  * Without VIMAGE revert to the default implementation.
423  */
424 #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
425 	(tag) = eventhandler_register(NULL, #name, func, arg, priority)
426 #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)	\
427 	eventhandler_register(NULL, #name, func, arg, priority)
428 #endif /* VIMAGE */
429 #endif /* _KERNEL */
430 
431 #endif /* !_NET_VNET_H_ */
432