xref: /freebsd/sys/net/vnet.h (revision 604d0dd551fa7d275cdf69911c9df4595a42f49f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2006-2009 University of Zagreb
5  * Copyright (c) 2006-2009 FreeBSD Foundation
6  * All rights reserved.
7  *
8  * This software was developed by the University of Zagreb and the
9  * FreeBSD Foundation under sponsorship by the Stichting NLnet and the
10  * FreeBSD Foundation.
11  *
12  * Copyright (c) 2009 Jeffrey Roberson <jeff@freebsd.org>
13  * Copyright (c) 2009 Robert N. M. Watson
14  * All rights reserved.
15  *
16  * Redistribution and use in source and binary forms, with or without
17  * modification, are permitted provided that the following conditions
18  * are met:
19  * 1. Redistributions of source code must retain the above copyright
20  *    notice, this list of conditions and the following disclaimer.
21  * 2. Redistributions in binary form must reproduce the above copyright
22  *    notice, this list of conditions and the following disclaimer in the
23  *    documentation and/or other materials provided with the distribution.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  * $FreeBSD$
38  */
39 
40 /*-
41  * This header file defines several sets of interfaces supporting virtualized
42  * network stacks:
43  *
44  * - Definition of 'struct vnet' and functions and macros to allocate/free/
45  *   manipulate it.
46  *
47  * - A virtual network stack memory allocator, which provides support for
48  *   virtualized global variables via a special linker set, set_vnet.
49  *
50  * - Virtualized sysinits/sysuninits, which allow constructors and
51  *   destructors to be run for each network stack subsystem as virtual
52  *   instances are created and destroyed.
53  *
54  * If VIMAGE isn't compiled into the kernel, virtualized global variables
55  * compile to normal global variables, and virtualized sysinits to regular
56  * sysinits.
57  */
58 
59 #ifndef _NET_VNET_H_
60 #define	_NET_VNET_H_
61 
62 /*
63  * struct vnet describes a virtualized network stack, and is primarily a
64  * pointer to storage for virtualized global variables.  Expose to userspace
65  * as required for libkvm.
66  */
67 #if defined(_KERNEL) || defined(_WANT_VNET)
68 #include <sys/queue.h>
69 
70 struct vnet {
71 	LIST_ENTRY(vnet)	 vnet_le;	/* all vnets list */
72 	u_int			 vnet_magic_n;
73 	u_int			 vnet_ifcnt;
74 	u_int			 vnet_sockcnt;
75 	u_int			 vnet_state;	/* SI_SUB_* */
76 	void			*vnet_data_mem;
77 	uintptr_t		 vnet_data_base;
78 	bool			 vnet_shutdown;	/* Shutdown in progress. */
79 } __aligned(CACHE_LINE_SIZE);
80 #define	VNET_MAGIC_N	0x5e4a6f28
81 
82 /*
83  * These two virtual network stack allocator definitions are also required
84  * for libkvm so that it can evaluate virtualized global variables.
85  */
86 #define	VNET_SETNAME		"set_vnet"
87 #define	VNET_SYMPREFIX		"vnet_entry_"
88 #endif
89 
90 #ifdef _KERNEL
91 
92 #define	VNET_PCPUSTAT_DECLARE(type, name)	\
93     VNET_DECLARE(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
94 
95 #define	VNET_PCPUSTAT_DEFINE(type, name)	\
96     VNET_DEFINE(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
97 #define	VNET_PCPUSTAT_DEFINE_STATIC(type, name)	\
98     VNET_DEFINE_STATIC(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
99 
100 #define	VNET_PCPUSTAT_ALLOC(name, wait)	\
101     COUNTER_ARRAY_ALLOC(VNET(name), \
102 	sizeof(VNET(name)) / sizeof(counter_u64_t), (wait))
103 
104 #define	VNET_PCPUSTAT_FREE(name)	\
105     COUNTER_ARRAY_FREE(VNET(name), sizeof(VNET(name)) / sizeof(counter_u64_t))
106 
107 #define	VNET_PCPUSTAT_ADD(type, name, f, v)	\
108     counter_u64_add(VNET(name)[offsetof(type, f) / sizeof(uint64_t)], (v))
109 
110 #define	VNET_PCPUSTAT_FETCH(type, name, f)	\
111     counter_u64_fetch(VNET(name)[offsetof(type, f) / sizeof(uint64_t)])
112 
113 #define	VNET_PCPUSTAT_SYSINIT(name)	\
114 static void				\
115 vnet_##name##_init(const void *unused)	\
116 {					\
117 	VNET_PCPUSTAT_ALLOC(name, M_WAITOK);	\
118 }					\
119 VNET_SYSINIT(vnet_ ## name ## _init, SI_SUB_INIT_IF,			\
120     SI_ORDER_FIRST, vnet_ ## name ## _init, NULL)
121 
122 #define	VNET_PCPUSTAT_SYSUNINIT(name)					\
123 static void								\
124 vnet_##name##_uninit(const void *unused)				\
125 {									\
126 	VNET_PCPUSTAT_FREE(name);					\
127 }									\
128 VNET_SYSUNINIT(vnet_ ## name ## _uninit, SI_SUB_INIT_IF,		\
129     SI_ORDER_FIRST, vnet_ ## name ## _uninit, NULL)
130 
131 #ifdef SYSCTL_OID
132 #define	SYSCTL_VNET_PCPUSTAT(parent, nbr, name, type, array, desc)	\
133 static int								\
134 array##_sysctl(SYSCTL_HANDLER_ARGS)					\
135 {									\
136 	type s;								\
137 	CTASSERT((sizeof(type) / sizeof(uint64_t)) ==			\
138 	    (sizeof(VNET(array)) / sizeof(counter_u64_t)));		\
139 	COUNTER_ARRAY_COPY(VNET(array), &s, sizeof(type) / sizeof(uint64_t));\
140 	if (req->newptr)						\
141 		COUNTER_ARRAY_ZERO(VNET(array),				\
142 		    sizeof(type) / sizeof(uint64_t));			\
143 	return (SYSCTL_OUT(req, &s, sizeof(type)));			\
144 }									\
145 SYSCTL_PROC(parent, nbr, name, CTLFLAG_VNET | CTLTYPE_OPAQUE | CTLFLAG_RW, \
146     NULL, 0, array ## _sysctl, "I", desc)
147 #endif /* SYSCTL_OID */
148 
149 #ifdef VIMAGE
150 #include <sys/lock.h>
151 #include <sys/proc.h>			/* for struct thread */
152 #include <sys/rwlock.h>
153 #include <sys/sx.h>
154 
155 /*
156  * Location of the kernel's 'set_vnet' linker set.
157  */
158 extern uintptr_t	*__start_set_vnet;
159 __GLOBL(__start_set_vnet);
160 extern uintptr_t	*__stop_set_vnet;
161 __GLOBL(__stop_set_vnet);
162 
163 #define	VNET_START	(uintptr_t)&__start_set_vnet
164 #define	VNET_STOP	(uintptr_t)&__stop_set_vnet
165 
166 /*
167  * Functions to allocate and destroy virtual network stacks.
168  */
169 struct vnet *vnet_alloc(void);
170 void	vnet_destroy(struct vnet *vnet);
171 
172 /*
173  * The current virtual network stack -- we may wish to move this to struct
174  * pcpu in the future.
175  */
176 #define	curvnet	curthread->td_vnet
177 
178 /*
179  * Various macros -- get and set the current network stack, but also
180  * assertions.
181  */
182 #if defined(INVARIANTS) || defined(VNET_DEBUG)
183 #define	VNET_ASSERT(exp, msg)	do {					\
184 	if (!(exp))							\
185 		panic msg;						\
186 } while (0)
187 #else
188 #define	VNET_ASSERT(exp, msg)	do {					\
189 } while (0)
190 #endif
191 
192 #ifdef VNET_DEBUG
193 void vnet_log_recursion(struct vnet *, const char *, int);
194 
195 #define	CURVNET_SET_QUIET(arg)						\
196 	VNET_ASSERT((arg) != NULL && (arg)->vnet_magic_n == VNET_MAGIC_N, \
197 	    ("CURVNET_SET at %s:%d %s() curvnet=%p vnet=%p",		\
198 	    __FILE__, __LINE__, __func__, curvnet, (arg)));		\
199 	struct vnet *saved_vnet = curvnet;				\
200 	const char *saved_vnet_lpush = curthread->td_vnet_lpush;	\
201 	curvnet = arg;							\
202 	curthread->td_vnet_lpush = __func__;
203 
204 #define	CURVNET_SET_VERBOSE(arg)					\
205 	CURVNET_SET_QUIET(arg)						\
206 	if (saved_vnet)							\
207 		vnet_log_recursion(saved_vnet, saved_vnet_lpush, __LINE__);
208 
209 #define	CURVNET_SET(arg)	CURVNET_SET_VERBOSE(arg)
210 
211 #define	CURVNET_RESTORE()						\
212 	VNET_ASSERT(curvnet != NULL && (saved_vnet == NULL ||		\
213 	    saved_vnet->vnet_magic_n == VNET_MAGIC_N),			\
214 	    ("CURVNET_RESTORE at %s:%d %s() curvnet=%p saved_vnet=%p",	\
215 	    __FILE__, __LINE__, __func__, curvnet, saved_vnet));	\
216 	curvnet = saved_vnet;						\
217 	curthread->td_vnet_lpush = saved_vnet_lpush;
218 #else /* !VNET_DEBUG */
219 
220 #define	CURVNET_SET_QUIET(arg)						\
221 	VNET_ASSERT((arg) != NULL && (arg)->vnet_magic_n == VNET_MAGIC_N, \
222 	    ("CURVNET_SET at %s:%d %s() curvnet=%p vnet=%p",		\
223 	    __FILE__, __LINE__, __func__, curvnet, (arg)));		\
224 	struct vnet *saved_vnet = curvnet;				\
225 	curvnet = arg;
226 
227 #define	CURVNET_SET_VERBOSE(arg)					\
228 	CURVNET_SET_QUIET(arg)
229 
230 #define	CURVNET_SET(arg)	CURVNET_SET_VERBOSE(arg)
231 
232 #define	CURVNET_RESTORE()						\
233 	VNET_ASSERT(curvnet != NULL && (saved_vnet == NULL ||		\
234 	    saved_vnet->vnet_magic_n == VNET_MAGIC_N),			\
235 	    ("CURVNET_RESTORE at %s:%d %s() curvnet=%p saved_vnet=%p",	\
236 	    __FILE__, __LINE__, __func__, curvnet, saved_vnet));	\
237 	curvnet = saved_vnet;
238 #endif /* VNET_DEBUG */
239 
240 extern struct vnet *vnet0;
241 #define	IS_DEFAULT_VNET(arg)	((arg) == vnet0)
242 
243 #define	CRED_TO_VNET(cr)	(cr)->cr_prison->pr_vnet
244 #define	TD_TO_VNET(td)		CRED_TO_VNET((td)->td_ucred)
245 #define	P_TO_VNET(p)		CRED_TO_VNET((p)->p_ucred)
246 
247 /*
248  * Global linked list of all virtual network stacks, along with read locks to
249  * access it.  If a caller may sleep while accessing the list, it must use
250  * the sleepable lock macros.
251  */
252 LIST_HEAD(vnet_list_head, vnet);
253 extern struct vnet_list_head vnet_head;
254 extern struct rwlock vnet_rwlock;
255 extern struct sx vnet_sxlock;
256 
257 #define	VNET_LIST_RLOCK()		sx_slock(&vnet_sxlock)
258 #define	VNET_LIST_RLOCK_NOSLEEP()	rw_rlock(&vnet_rwlock)
259 #define	VNET_LIST_RUNLOCK()		sx_sunlock(&vnet_sxlock)
260 #define	VNET_LIST_RUNLOCK_NOSLEEP()	rw_runlock(&vnet_rwlock)
261 
262 /*
263  * Iteration macros to walk the global list of virtual network stacks.
264  */
265 #define	VNET_ITERATOR_DECL(arg)	struct vnet *arg
266 #define	VNET_FOREACH(arg)	LIST_FOREACH((arg), &vnet_head, vnet_le)
267 
268 /*
269  * Virtual network stack memory allocator, which allows global variables to
270  * be automatically instantiated for each network stack instance.
271  */
272 #define	VNET_NAME(n)		vnet_entry_##n
273 #define	VNET_DECLARE(t, n)	extern t VNET_NAME(n)
274 /* struct _hack is to stop this from being used with static data */
275 #define	VNET_DEFINE(t, n)	\
276     struct _hack; t VNET_NAME(n) __section(VNET_SETNAME) __used
277 #if defined(KLD_MODULE) && (defined(__aarch64__) || defined(__riscv) \
278 		|| defined(__powerpc64__))
279 /*
280  * As with DPCPU_DEFINE_STATIC we are unable to mark this data as static
281  * in modules on some architectures.
282  */
283 #define	VNET_DEFINE_STATIC(t, n) \
284     t VNET_NAME(n) __section(VNET_SETNAME) __used
285 #else
286 #define	VNET_DEFINE_STATIC(t, n) \
287     static t VNET_NAME(n) __section(VNET_SETNAME) __used
288 #endif
289 #define	_VNET_PTR(b, n)		(__typeof(VNET_NAME(n))*)		\
290 				    ((b) + (uintptr_t)&VNET_NAME(n))
291 
292 #define	_VNET(b, n)		(*_VNET_PTR(b, n))
293 
294 /*
295  * Virtualized global variable accessor macros.
296  */
297 #define	VNET_VNET_PTR(vnet, n)		_VNET_PTR((vnet)->vnet_data_base, n)
298 #define	VNET_VNET(vnet, n)		(*VNET_VNET_PTR((vnet), n))
299 
300 #define	VNET_PTR(n)		VNET_VNET_PTR(curvnet, n)
301 #define	VNET(n)			VNET_VNET(curvnet, n)
302 
303 /*
304  * Virtual network stack allocator interfaces from the kernel linker.
305  */
306 void	*vnet_data_alloc(int size);
307 void	 vnet_data_copy(void *start, int size);
308 void	 vnet_data_free(void *start_arg, int size);
309 
310 /*
311  * Virtual sysinit mechanism, allowing network stack components to declare
312  * startup and shutdown methods to be run when virtual network stack
313  * instances are created and destroyed.
314  */
315 #include <sys/kernel.h>
316 
317 /*
318  * SYSINIT/SYSUNINIT variants that provide per-vnet constructors and
319  * destructors.
320  */
321 struct vnet_sysinit {
322 	enum sysinit_sub_id	subsystem;
323 	enum sysinit_elem_order	order;
324 	sysinit_cfunc_t		func;
325 	const void		*arg;
326 	TAILQ_ENTRY(vnet_sysinit) link;
327 };
328 
329 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
330 	CTASSERT((subsystem) > SI_SUB_VNET &&				\
331 	    (subsystem) <= SI_SUB_VNET_DONE);				\
332 	static struct vnet_sysinit ident ## _vnet_init = {		\
333 		subsystem,						\
334 		order,							\
335 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
336 		(arg)							\
337 	};								\
338 	SYSINIT(vnet_init_ ## ident, subsystem, order,			\
339 	    vnet_register_sysinit, &ident ## _vnet_init);		\
340 	SYSUNINIT(vnet_init_ ## ident, subsystem, order,		\
341 	    vnet_deregister_sysinit, &ident ## _vnet_init)
342 
343 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
344 	CTASSERT((subsystem) > SI_SUB_VNET &&				\
345 	    (subsystem) <= SI_SUB_VNET_DONE);				\
346 	static struct vnet_sysinit ident ## _vnet_uninit = {		\
347 		subsystem,						\
348 		order,							\
349 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
350 		(arg)							\
351 	};								\
352 	SYSINIT(vnet_uninit_ ## ident, subsystem, order,		\
353 	    vnet_register_sysuninit, &ident ## _vnet_uninit);		\
354 	SYSUNINIT(vnet_uninit_ ## ident, subsystem, order,		\
355 	    vnet_deregister_sysuninit, &ident ## _vnet_uninit)
356 
357 /*
358  * Run per-vnet sysinits or sysuninits during vnet creation/destruction.
359  */
360 void	 vnet_sysinit(void);
361 void	 vnet_sysuninit(void);
362 
363 /*
364  * Interfaces for managing per-vnet constructors and destructors.
365  */
366 void	vnet_register_sysinit(void *arg);
367 void	vnet_register_sysuninit(void *arg);
368 void	vnet_deregister_sysinit(void *arg);
369 void	vnet_deregister_sysuninit(void *arg);
370 
371 /*
372  * EVENTHANDLER(9) extensions.
373  */
374 #include <sys/eventhandler.h>
375 
376 void	vnet_global_eventhandler_iterator_func(void *, ...);
377 #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
378 do {									\
379 	if (IS_DEFAULT_VNET(curvnet)) {					\
380 		(tag) = vimage_eventhandler_register(NULL, #name, func,	\
381 		    arg, priority,					\
382 		    vnet_global_eventhandler_iterator_func);		\
383 	}								\
384 } while(0)
385 #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)	\
386 do {									\
387 	if (IS_DEFAULT_VNET(curvnet)) {					\
388 		vimage_eventhandler_register(NULL, #name, func,		\
389 		    arg, priority,					\
390 		    vnet_global_eventhandler_iterator_func);		\
391 	}								\
392 } while(0)
393 
394 #else /* !VIMAGE */
395 
396 /*
397  * Various virtual network stack macros compile to no-ops without VIMAGE.
398  */
399 #define	curvnet			NULL
400 
401 #define	VNET_ASSERT(exp, msg)
402 #define	CURVNET_SET(arg)
403 #define	CURVNET_SET_QUIET(arg)
404 #define	CURVNET_RESTORE()
405 
406 #define	VNET_LIST_RLOCK()
407 #define	VNET_LIST_RLOCK_NOSLEEP()
408 #define	VNET_LIST_RUNLOCK()
409 #define	VNET_LIST_RUNLOCK_NOSLEEP()
410 #define	VNET_ITERATOR_DECL(arg)
411 #define	VNET_FOREACH(arg)
412 
413 #define	IS_DEFAULT_VNET(arg)	1
414 #define	CRED_TO_VNET(cr)	NULL
415 #define	TD_TO_VNET(td)		NULL
416 #define	P_TO_VNET(p)		NULL
417 
418 /*
419  * Versions of the VNET macros that compile to normal global variables and
420  * standard sysctl definitions.
421  */
422 #define	VNET_NAME(n)		n
423 #define	VNET_DECLARE(t, n)	extern t n
424 #define	VNET_DEFINE(t, n)	struct _hack; t n
425 #define	VNET_DEFINE_STATIC(t, n)	static t n
426 #define	_VNET_PTR(b, n)		&VNET_NAME(n)
427 
428 /*
429  * Virtualized global variable accessor macros.
430  */
431 #define	VNET_VNET_PTR(vnet, n)		(&(n))
432 #define	VNET_VNET(vnet, n)		(n)
433 
434 #define	VNET_PTR(n)		(&(n))
435 #define	VNET(n)			(n)
436 
437 /*
438  * When VIMAGE isn't compiled into the kernel, VNET_SYSINIT/VNET_SYSUNINIT
439  * map into normal sysinits, which have the same ordering properties.
440  */
441 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
442 	SYSINIT(ident, subsystem, order, func, arg)
443 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
444 	SYSUNINIT(ident, subsystem, order, func, arg)
445 
446 /*
447  * Without VIMAGE revert to the default implementation.
448  */
449 #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
450 	(tag) = eventhandler_register(NULL, #name, func, arg, priority)
451 #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)	\
452 	eventhandler_register(NULL, #name, func, arg, priority)
453 #endif /* VIMAGE */
454 #endif /* _KERNEL */
455 
456 #endif /* !_NET_VNET_H_ */
457