xref: /freebsd/sys/net/vnet.h (revision ff0ba87247820afbdfdc1b307c803f7923d0e4d3)
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 #define	VNET_PCPUSTAT_DECLARE(type, name)	\
89     VNET_DECLARE(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
90 
91 #define	VNET_PCPUSTAT_DEFINE(type, name)	\
92     VNET_DEFINE(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
93 
94 #define	VNET_PCPUSTAT_ALLOC(name, wait)	\
95     COUNTER_ARRAY_ALLOC(VNET(name), \
96 	sizeof(VNET(name)) / sizeof(counter_u64_t), (wait))
97 
98 #define	VNET_PCPUSTAT_FREE(name)	\
99     COUNTER_ARRAY_FREE(VNET(name), sizeof(VNET(name)) / sizeof(counter_u64_t))
100 
101 #define	VNET_PCPUSTAT_ADD(type, name, f, v)	\
102     counter_u64_add(VNET(name)[offsetof(type, f) / sizeof(uint64_t)], (v))
103 
104 #define	VNET_PCPUSTAT_SYSINIT(name)	\
105 static void				\
106 vnet_##name##_init(const void *unused)	\
107 {					\
108 	VNET_PCPUSTAT_ALLOC(name, M_WAITOK);	\
109 }					\
110 VNET_SYSINIT(vnet_ ## name ## _init, SI_SUB_PROTO_IFATTACHDOMAIN,	\
111     SI_ORDER_ANY, vnet_ ## name ## _init, NULL)
112 
113 #define	VNET_PCPUSTAT_SYSUNINIT(name)					\
114 static void								\
115 vnet_##name##_uninit(const void *unused)				\
116 {									\
117 	VNET_PCPUSTAT_FREE(name);					\
118 }									\
119 VNET_SYSUNINIT(vnet_ ## name ## _uninit, SI_SUB_PROTO_IFATTACHDOMAIN,	\
120     SI_ORDER_ANY, vnet_ ## name ## _uninit, NULL)
121 
122 #ifdef SYSCTL_OID
123 #define	SYSCTL_VNET_PCPUSTAT(parent, nbr, name, type, array, desc)	\
124 static int								\
125 array##_sysctl(SYSCTL_HANDLER_ARGS)					\
126 {									\
127 	type s;								\
128 	CTASSERT((sizeof(type) / sizeof(uint64_t)) ==			\
129 	    (sizeof(VNET(array)) / sizeof(counter_u64_t)));		\
130 	COUNTER_ARRAY_COPY(VNET(array), &s, sizeof(type) / sizeof(uint64_t));\
131 	if (req->newptr)						\
132 		COUNTER_ARRAY_ZERO(VNET(array),				\
133 		    sizeof(type) / sizeof(uint64_t));			\
134 	return (SYSCTL_OUT(req, &s, sizeof(type)));			\
135 }									\
136 SYSCTL_PROC(parent, nbr, name, CTLFLAG_VNET | CTLTYPE_OPAQUE | CTLFLAG_RW, \
137     NULL, 0, array ## _sysctl, "I", desc)
138 #endif /* SYSCTL_OID */
139 
140 #ifdef VIMAGE
141 #include <sys/lock.h>
142 #include <sys/proc.h>			/* for struct thread */
143 #include <sys/rwlock.h>
144 #include <sys/sx.h>
145 
146 /*
147  * Location of the kernel's 'set_vnet' linker set.
148  */
149 extern uintptr_t	*__start_set_vnet;
150 __GLOBL(__start_set_vnet);
151 extern uintptr_t	*__stop_set_vnet;
152 __GLOBL(__stop_set_vnet);
153 
154 #define	VNET_START	(uintptr_t)&__start_set_vnet
155 #define	VNET_STOP	(uintptr_t)&__stop_set_vnet
156 
157 /*
158  * Functions to allocate and destroy virtual network stacks.
159  */
160 struct vnet *vnet_alloc(void);
161 void	vnet_destroy(struct vnet *vnet);
162 
163 /*
164  * The current virtual network stack -- we may wish to move this to struct
165  * pcpu in the future.
166  */
167 #define	curvnet	curthread->td_vnet
168 
169 /*
170  * Various macros -- get and set the current network stack, but also
171  * assertions.
172  */
173 #if defined(INVARIANTS) || defined(VNET_DEBUG)
174 #define	VNET_ASSERT(exp, msg)	do {					\
175 	if (!(exp))							\
176 		panic msg;						\
177 } while (0)
178 #else
179 #define	VNET_ASSERT(exp, msg)	do {					\
180 } while (0)
181 #endif
182 
183 #ifdef VNET_DEBUG
184 void vnet_log_recursion(struct vnet *, const char *, int);
185 
186 #define	CURVNET_SET_QUIET(arg)						\
187 	VNET_ASSERT((arg) != NULL && (arg)->vnet_magic_n == VNET_MAGIC_N, \
188 	    ("CURVNET_SET at %s:%d %s() curvnet=%p vnet=%p",		\
189 	    __FILE__, __LINE__, __func__, curvnet, (arg)));		\
190 	struct vnet *saved_vnet = curvnet;				\
191 	const char *saved_vnet_lpush = curthread->td_vnet_lpush;	\
192 	curvnet = arg;							\
193 	curthread->td_vnet_lpush = __func__;
194 
195 #define	CURVNET_SET_VERBOSE(arg)					\
196 	CURVNET_SET_QUIET(arg)						\
197 	if (saved_vnet)							\
198 		vnet_log_recursion(saved_vnet, saved_vnet_lpush, __LINE__);
199 
200 #define	CURVNET_SET(arg)	CURVNET_SET_VERBOSE(arg)
201 
202 #define	CURVNET_RESTORE()						\
203 	VNET_ASSERT(curvnet != NULL && (saved_vnet == NULL ||		\
204 	    saved_vnet->vnet_magic_n == VNET_MAGIC_N),			\
205 	    ("CURVNET_RESTORE at %s:%d %s() curvnet=%p saved_vnet=%p",	\
206 	    __FILE__, __LINE__, __func__, curvnet, saved_vnet));	\
207 	curvnet = saved_vnet;						\
208 	curthread->td_vnet_lpush = saved_vnet_lpush;
209 #else /* !VNET_DEBUG */
210 
211 #define	CURVNET_SET_QUIET(arg)						\
212 	VNET_ASSERT((arg) != NULL && (arg)->vnet_magic_n == VNET_MAGIC_N, \
213 	    ("CURVNET_SET at %s:%d %s() curvnet=%p vnet=%p",		\
214 	    __FILE__, __LINE__, __func__, curvnet, (arg)));		\
215 	struct vnet *saved_vnet = curvnet;				\
216 	curvnet = arg;
217 
218 #define	CURVNET_SET_VERBOSE(arg)					\
219 	CURVNET_SET_QUIET(arg)
220 
221 #define	CURVNET_SET(arg)	CURVNET_SET_VERBOSE(arg)
222 
223 #define	CURVNET_RESTORE()						\
224 	VNET_ASSERT(curvnet != NULL && (saved_vnet == NULL ||		\
225 	    saved_vnet->vnet_magic_n == VNET_MAGIC_N),			\
226 	    ("CURVNET_RESTORE at %s:%d %s() curvnet=%p saved_vnet=%p",	\
227 	    __FILE__, __LINE__, __func__, curvnet, saved_vnet));	\
228 	curvnet = saved_vnet;
229 #endif /* VNET_DEBUG */
230 
231 extern struct vnet *vnet0;
232 #define	IS_DEFAULT_VNET(arg)	((arg) == vnet0)
233 
234 #define	CRED_TO_VNET(cr)	(cr)->cr_prison->pr_vnet
235 #define	TD_TO_VNET(td)		CRED_TO_VNET((td)->td_ucred)
236 #define	P_TO_VNET(p)		CRED_TO_VNET((p)->p_ucred)
237 
238 /*
239  * Global linked list of all virtual network stacks, along with read locks to
240  * access it.  If a caller may sleep while accessing the list, it must use
241  * the sleepable lock macros.
242  */
243 LIST_HEAD(vnet_list_head, vnet);
244 extern struct vnet_list_head vnet_head;
245 extern struct rwlock vnet_rwlock;
246 extern struct sx vnet_sxlock;
247 
248 #define	VNET_LIST_RLOCK()		sx_slock(&vnet_sxlock)
249 #define	VNET_LIST_RLOCK_NOSLEEP()	rw_rlock(&vnet_rwlock)
250 #define	VNET_LIST_RUNLOCK()		sx_sunlock(&vnet_sxlock)
251 #define	VNET_LIST_RUNLOCK_NOSLEEP()	rw_runlock(&vnet_rwlock)
252 
253 /*
254  * Iteration macros to walk the global list of virtual network stacks.
255  */
256 #define	VNET_ITERATOR_DECL(arg)	struct vnet *arg
257 #define	VNET_FOREACH(arg)	LIST_FOREACH((arg), &vnet_head, vnet_le)
258 
259 /*
260  * Virtual network stack memory allocator, which allows global variables to
261  * be automatically instantiated for each network stack instance.
262  */
263 #define	VNET_NAME(n)		vnet_entry_##n
264 #define	VNET_DECLARE(t, n)	extern t VNET_NAME(n)
265 #define	VNET_DEFINE(t, n)	t VNET_NAME(n) __section(VNET_SETNAME) __used
266 #define	_VNET_PTR(b, n)		(__typeof(VNET_NAME(n))*)		\
267 				    ((b) + (uintptr_t)&VNET_NAME(n))
268 
269 #define	_VNET(b, n)		(*_VNET_PTR(b, n))
270 
271 /*
272  * Virtualized global variable accessor macros.
273  */
274 #define	VNET_VNET_PTR(vnet, n)		_VNET_PTR((vnet)->vnet_data_base, n)
275 #define	VNET_VNET(vnet, n)		(*VNET_VNET_PTR((vnet), n))
276 
277 #define	VNET_PTR(n)		VNET_VNET_PTR(curvnet, n)
278 #define	VNET(n)			VNET_VNET(curvnet, n)
279 
280 /*
281  * Virtual network stack allocator interfaces from the kernel linker.
282  */
283 void	*vnet_data_alloc(int size);
284 void	 vnet_data_copy(void *start, int size);
285 void	 vnet_data_free(void *start_arg, int size);
286 
287 /*
288  * Virtual sysinit mechanism, allowing network stack components to declare
289  * startup and shutdown methods to be run when virtual network stack
290  * instances are created and destroyed.
291  */
292 #include <sys/kernel.h>
293 
294 /*
295  * SYSINIT/SYSUNINIT variants that provide per-vnet constructors and
296  * destructors.
297  */
298 struct vnet_sysinit {
299 	enum sysinit_sub_id	subsystem;
300 	enum sysinit_elem_order	order;
301 	sysinit_cfunc_t		func;
302 	const void		*arg;
303 	TAILQ_ENTRY(vnet_sysinit) link;
304 };
305 
306 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
307 	static struct vnet_sysinit ident ## _vnet_init = {		\
308 		subsystem,						\
309 		order,							\
310 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
311 		(arg)							\
312 	};								\
313 	SYSINIT(vnet_init_ ## ident, subsystem, order,			\
314 	    vnet_register_sysinit, &ident ## _vnet_init);		\
315 	SYSUNINIT(vnet_init_ ## ident, subsystem, order,		\
316 	    vnet_deregister_sysinit, &ident ## _vnet_init)
317 
318 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
319 	static struct vnet_sysinit ident ## _vnet_uninit = {		\
320 		subsystem,						\
321 		order,							\
322 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
323 		(arg)							\
324 	};								\
325 	SYSINIT(vnet_uninit_ ## ident, subsystem, order,		\
326 	    vnet_register_sysuninit, &ident ## _vnet_uninit);		\
327 	SYSUNINIT(vnet_uninit_ ## ident, subsystem, order,		\
328 	    vnet_deregister_sysuninit, &ident ## _vnet_uninit)
329 
330 /*
331  * Run per-vnet sysinits or sysuninits during vnet creation/destruction.
332  */
333 void	 vnet_sysinit(void);
334 void	 vnet_sysuninit(void);
335 
336 /*
337  * Interfaces for managing per-vnet constructors and destructors.
338  */
339 void	vnet_register_sysinit(void *arg);
340 void	vnet_register_sysuninit(void *arg);
341 void	vnet_deregister_sysinit(void *arg);
342 void	vnet_deregister_sysuninit(void *arg);
343 
344 /*
345  * EVENTHANDLER(9) extensions.
346  */
347 #include <sys/eventhandler.h>
348 
349 void	vnet_global_eventhandler_iterator_func(void *, ...);
350 #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
351 do {									\
352 	if (IS_DEFAULT_VNET(curvnet)) {					\
353 		(tag) = vimage_eventhandler_register(NULL, #name, func,	\
354 		    arg, priority,					\
355 		    vnet_global_eventhandler_iterator_func);		\
356 	}								\
357 } while(0)
358 #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)	\
359 do {									\
360 	if (IS_DEFAULT_VNET(curvnet)) {					\
361 		vimage_eventhandler_register(NULL, #name, func,		\
362 		    arg, priority,					\
363 		    vnet_global_eventhandler_iterator_func);		\
364 	}								\
365 } while(0)
366 
367 #else /* !VIMAGE */
368 
369 /*
370  * Various virtual network stack macros compile to no-ops without VIMAGE.
371  */
372 #define	curvnet			NULL
373 
374 #define	VNET_ASSERT(exp, msg)
375 #define	CURVNET_SET(arg)
376 #define	CURVNET_SET_QUIET(arg)
377 #define	CURVNET_RESTORE()
378 
379 #define	VNET_LIST_RLOCK()
380 #define	VNET_LIST_RLOCK_NOSLEEP()
381 #define	VNET_LIST_RUNLOCK()
382 #define	VNET_LIST_RUNLOCK_NOSLEEP()
383 #define	VNET_ITERATOR_DECL(arg)
384 #define	VNET_FOREACH(arg)
385 
386 #define	IS_DEFAULT_VNET(arg)	1
387 #define	CRED_TO_VNET(cr)	NULL
388 #define	TD_TO_VNET(td)		NULL
389 #define	P_TO_VNET(p)		NULL
390 
391 /*
392  * Versions of the VNET macros that compile to normal global variables and
393  * standard sysctl definitions.
394  */
395 #define	VNET_NAME(n)		n
396 #define	VNET_DECLARE(t, n)	extern t n
397 #define	VNET_DEFINE(t, n)	t n
398 #define	_VNET_PTR(b, n)		&VNET_NAME(n)
399 
400 /*
401  * Virtualized global variable accessor macros.
402  */
403 #define	VNET_VNET_PTR(vnet, n)		(&(n))
404 #define	VNET_VNET(vnet, n)		(n)
405 
406 #define	VNET_PTR(n)		(&(n))
407 #define	VNET(n)			(n)
408 
409 /*
410  * When VIMAGE isn't compiled into the kernel, VNET_SYSINIT/VNET_SYSUNINIT
411  * map into normal sysinits, which have the same ordering properties.
412  */
413 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
414 	SYSINIT(ident, subsystem, order, func, arg)
415 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
416 	SYSUNINIT(ident, subsystem, order, func, arg)
417 
418 /*
419  * Without VIMAGE revert to the default implementation.
420  */
421 #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
422 	(tag) = eventhandler_register(NULL, #name, func, arg, priority)
423 #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)	\
424 	eventhandler_register(NULL, #name, func, arg, priority)
425 #endif /* VIMAGE */
426 #endif /* _KERNEL */
427 
428 #endif /* !_NET_VNET_H_ */
429