xref: /freebsd/sys/net/vnet.h (revision 3c4ba5f55438f7afd4f4b0b56f88f2bb505fd6a6)
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 <machine/param.h>	/* for CACHE_LINE_SIZE */
69 #include <sys/queue.h>
70 
71 struct vnet {
72 	LIST_ENTRY(vnet)	 vnet_le;	/* all vnets list */
73 	u_int			 vnet_magic_n;
74 	u_int			 vnet_ifcnt;
75 	u_int			 vnet_sockcnt;
76 	u_int			 vnet_state;	/* SI_SUB_* */
77 	void			*vnet_data_mem;
78 	uintptr_t		 vnet_data_base;
79 	bool			 vnet_shutdown;	/* Shutdown in progress. */
80 } __aligned(CACHE_LINE_SIZE);
81 #define	VNET_MAGIC_N	0x5e4a6f28
82 
83 /*
84  * These two virtual network stack allocator definitions are also required
85  * for libkvm so that it can evaluate virtualized global variables.
86  */
87 #define	VNET_SETNAME		"set_vnet"
88 #define	VNET_SYMPREFIX		"vnet_entry_"
89 #endif
90 
91 #ifdef _KERNEL
92 
93 #define	VNET_PCPUSTAT_DECLARE(type, name)	\
94     VNET_DECLARE(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
95 
96 #define	VNET_PCPUSTAT_DEFINE(type, name)	\
97     VNET_DEFINE(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
98 #define	VNET_PCPUSTAT_DEFINE_STATIC(type, name)	\
99     VNET_DEFINE_STATIC(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
100 
101 #define	VNET_PCPUSTAT_ALLOC(name, wait)	\
102     COUNTER_ARRAY_ALLOC(VNET(name), \
103 	sizeof(VNET(name)) / sizeof(counter_u64_t), (wait))
104 
105 #define	VNET_PCPUSTAT_FREE(name)	\
106     COUNTER_ARRAY_FREE(VNET(name), sizeof(VNET(name)) / sizeof(counter_u64_t))
107 
108 #define	VNET_PCPUSTAT_ADD(type, name, f, v)	\
109     counter_u64_add(VNET(name)[offsetof(type, f) / sizeof(uint64_t)], (v))
110 
111 #define	VNET_PCPUSTAT_FETCH(type, name, f)	\
112     counter_u64_fetch(VNET(name)[offsetof(type, f) / sizeof(uint64_t)])
113 
114 #define	VNET_PCPUSTAT_SYSINIT(name)	\
115 static void				\
116 vnet_##name##_init(const void *unused)	\
117 {					\
118 	VNET_PCPUSTAT_ALLOC(name, M_WAITOK);	\
119 }					\
120 VNET_SYSINIT(vnet_ ## name ## _init, SI_SUB_INIT_IF,			\
121     SI_ORDER_FIRST, vnet_ ## name ## _init, NULL)
122 
123 #define	VNET_PCPUSTAT_SYSUNINIT(name)					\
124 static void								\
125 vnet_##name##_uninit(const void *unused)				\
126 {									\
127 	VNET_PCPUSTAT_FREE(name);					\
128 }									\
129 VNET_SYSUNINIT(vnet_ ## name ## _uninit, SI_SUB_INIT_IF,		\
130     SI_ORDER_FIRST, vnet_ ## name ## _uninit, NULL)
131 
132 #ifdef SYSCTL_OID
133 #define	SYSCTL_VNET_PCPUSTAT(parent, nbr, name, type, array, desc)	\
134 static int								\
135 array##_sysctl(SYSCTL_HANDLER_ARGS)					\
136 {									\
137 	type s;								\
138 	CTASSERT((sizeof(type) / sizeof(uint64_t)) ==			\
139 	    (sizeof(VNET(array)) / sizeof(counter_u64_t)));		\
140 	COUNTER_ARRAY_COPY(VNET(array), &s, sizeof(type) / sizeof(uint64_t));\
141 	if (req->newptr)						\
142 		COUNTER_ARRAY_ZERO(VNET(array),				\
143 		    sizeof(type) / sizeof(uint64_t));			\
144 	return (SYSCTL_OUT(req, &s, sizeof(type)));			\
145 }									\
146 SYSCTL_PROC(parent, nbr, name,						\
147     CTLFLAG_VNET | CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_NEEDGIANT,	\
148     NULL, 0, array ## _sysctl, "I", desc)
149 #endif /* SYSCTL_OID */
150 
151 #ifdef VIMAGE
152 #include <sys/lock.h>
153 #include <sys/proc.h>			/* for struct thread */
154 #include <sys/rwlock.h>
155 #include <sys/sx.h>
156 
157 /*
158  * Location of the kernel's 'set_vnet' linker set.
159  */
160 extern uintptr_t	*__start_set_vnet;
161 __GLOBL(__start_set_vnet);
162 extern uintptr_t	*__stop_set_vnet;
163 __GLOBL(__stop_set_vnet);
164 
165 #define	VNET_START	(uintptr_t)&__start_set_vnet
166 #define	VNET_STOP	(uintptr_t)&__stop_set_vnet
167 
168 /*
169  * Functions to allocate and destroy virtual network stacks.
170  */
171 struct vnet *vnet_alloc(void);
172 void	vnet_destroy(struct vnet *vnet);
173 
174 /*
175  * The current virtual network stack -- we may wish to move this to struct
176  * pcpu in the future.
177  */
178 #define	curvnet	curthread->td_vnet
179 
180 /*
181  * Various macros -- get and set the current network stack, but also
182  * assertions.
183  */
184 #if defined(INVARIANTS) || defined(VNET_DEBUG)
185 #define	VNET_ASSERT(exp, msg)	do {					\
186 	if (!(exp))							\
187 		panic msg;						\
188 } while (0)
189 #else
190 #define	VNET_ASSERT(exp, msg)	do {					\
191 } while (0)
192 #endif
193 
194 #ifdef VNET_DEBUG
195 void vnet_log_recursion(struct vnet *, const char *, int);
196 
197 #define	CURVNET_SET_QUIET(arg)						\
198 	VNET_ASSERT((arg) != NULL && (arg)->vnet_magic_n == VNET_MAGIC_N, \
199 	    ("CURVNET_SET at %s:%d %s() curvnet=%p vnet=%p",		\
200 	    __FILE__, __LINE__, __func__, curvnet, (arg)));		\
201 	struct vnet *saved_vnet = curvnet;				\
202 	const char *saved_vnet_lpush = curthread->td_vnet_lpush;	\
203 	curvnet = arg;							\
204 	curthread->td_vnet_lpush = __func__;
205 
206 #define	CURVNET_SET_VERBOSE(arg)					\
207 	CURVNET_SET_QUIET(arg)						\
208 	if (saved_vnet)							\
209 		vnet_log_recursion(saved_vnet, saved_vnet_lpush, __LINE__);
210 
211 #define	CURVNET_SET(arg)	CURVNET_SET_VERBOSE(arg)
212 
213 #define	CURVNET_RESTORE()						\
214 	VNET_ASSERT(curvnet != NULL && (saved_vnet == NULL ||		\
215 	    saved_vnet->vnet_magic_n == VNET_MAGIC_N),			\
216 	    ("CURVNET_RESTORE at %s:%d %s() curvnet=%p saved_vnet=%p",	\
217 	    __FILE__, __LINE__, __func__, curvnet, saved_vnet));	\
218 	curvnet = saved_vnet;						\
219 	curthread->td_vnet_lpush = saved_vnet_lpush;
220 #else /* !VNET_DEBUG */
221 
222 #define	CURVNET_SET_QUIET(arg)						\
223 	VNET_ASSERT((arg) != NULL && (arg)->vnet_magic_n == VNET_MAGIC_N, \
224 	    ("CURVNET_SET at %s:%d %s() curvnet=%p vnet=%p",		\
225 	    __FILE__, __LINE__, __func__, curvnet, (arg)));		\
226 	struct vnet *saved_vnet = curvnet;				\
227 	curvnet = arg;
228 
229 #define	CURVNET_SET_VERBOSE(arg)					\
230 	CURVNET_SET_QUIET(arg)
231 
232 #define	CURVNET_SET(arg)	CURVNET_SET_VERBOSE(arg)
233 
234 #define	CURVNET_RESTORE()						\
235 	VNET_ASSERT(curvnet != NULL && (saved_vnet == NULL ||		\
236 	    saved_vnet->vnet_magic_n == VNET_MAGIC_N),			\
237 	    ("CURVNET_RESTORE at %s:%d %s() curvnet=%p saved_vnet=%p",	\
238 	    __FILE__, __LINE__, __func__, curvnet, saved_vnet));	\
239 	curvnet = saved_vnet;
240 #endif /* VNET_DEBUG */
241 
242 #define	CURVNET_ASSERT_SET()						\
243 	VNET_ASSERT(curvnet != NULL, ("vnet is not set at %s:%d %s()",  \
244 	    __FILE__, __LINE__, __func__))
245 
246 extern struct vnet *vnet0;
247 #define	IS_DEFAULT_VNET(arg)	((arg) == vnet0)
248 
249 #define	CRED_TO_VNET(cr)	(cr)->cr_prison->pr_vnet
250 #define	TD_TO_VNET(td)		CRED_TO_VNET((td)->td_ucred)
251 #define	P_TO_VNET(p)		CRED_TO_VNET((p)->p_ucred)
252 
253 /*
254  * Global linked list of all virtual network stacks, along with read locks to
255  * access it.  If a caller may sleep while accessing the list, it must use
256  * the sleepable lock macros.
257  */
258 LIST_HEAD(vnet_list_head, vnet);
259 extern struct vnet_list_head vnet_head;
260 extern struct rwlock vnet_rwlock;
261 extern struct sx vnet_sxlock;
262 
263 #define	VNET_LIST_RLOCK()		sx_slock(&vnet_sxlock)
264 #define	VNET_LIST_RLOCK_NOSLEEP()	rw_rlock(&vnet_rwlock)
265 #define	VNET_LIST_RUNLOCK()		sx_sunlock(&vnet_sxlock)
266 #define	VNET_LIST_RUNLOCK_NOSLEEP()	rw_runlock(&vnet_rwlock)
267 
268 /*
269  * Iteration macros to walk the global list of virtual network stacks.
270  */
271 #define	VNET_ITERATOR_DECL(arg)	struct vnet *arg
272 #define	VNET_FOREACH(arg)	LIST_FOREACH((arg), &vnet_head, vnet_le)
273 
274 /*
275  * Virtual network stack memory allocator, which allows global variables to
276  * be automatically instantiated for each network stack instance.
277  */
278 #define	VNET_NAME(n)		vnet_entry_##n
279 #define	VNET_DECLARE(t, n)	extern t VNET_NAME(n)
280 /* struct _hack is to stop this from being used with static data */
281 #define	VNET_DEFINE(t, n)	\
282     struct _hack; t VNET_NAME(n) __section(VNET_SETNAME) __used
283 #if defined(KLD_MODULE) && (defined(__aarch64__) || defined(__riscv) \
284 		|| defined(__powerpc64__))
285 /*
286  * As with DPCPU_DEFINE_STATIC we are unable to mark this data as static
287  * in modules on some architectures.
288  */
289 #define	VNET_DEFINE_STATIC(t, n) \
290     t VNET_NAME(n) __section(VNET_SETNAME) __used
291 #else
292 #define	VNET_DEFINE_STATIC(t, n) \
293     static t VNET_NAME(n) __section(VNET_SETNAME) __used
294 #endif
295 #define	_VNET_PTR(b, n)		(__typeof(VNET_NAME(n))*)		\
296 				    ((b) + (uintptr_t)&VNET_NAME(n))
297 
298 #define	_VNET(b, n)		(*_VNET_PTR(b, n))
299 
300 /*
301  * Virtualized global variable accessor macros.
302  */
303 #define	VNET_VNET_PTR(vnet, n)		_VNET_PTR((vnet)->vnet_data_base, n)
304 #define	VNET_VNET(vnet, n)		(*VNET_VNET_PTR((vnet), n))
305 
306 #define	VNET_PTR(n)		VNET_VNET_PTR(curvnet, n)
307 #define	VNET(n)			VNET_VNET(curvnet, n)
308 
309 /*
310  * Virtual network stack allocator interfaces from the kernel linker.
311  */
312 void	*vnet_data_alloc(int size);
313 void	 vnet_data_copy(void *start, int size);
314 void	 vnet_data_free(void *start_arg, int size);
315 
316 /*
317  * Virtual sysinit mechanism, allowing network stack components to declare
318  * startup and shutdown methods to be run when virtual network stack
319  * instances are created and destroyed.
320  */
321 #include <sys/kernel.h>
322 
323 /*
324  * SYSINIT/SYSUNINIT variants that provide per-vnet constructors and
325  * destructors.
326  */
327 struct vnet_sysinit {
328 	enum sysinit_sub_id	subsystem;
329 	enum sysinit_elem_order	order;
330 	sysinit_cfunc_t		func;
331 	const void		*arg;
332 	TAILQ_ENTRY(vnet_sysinit) link;
333 };
334 
335 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
336 	CTASSERT((subsystem) > SI_SUB_VNET &&				\
337 	    (subsystem) <= SI_SUB_VNET_DONE);				\
338 	static struct vnet_sysinit ident ## _vnet_init = {		\
339 		subsystem,						\
340 		order,							\
341 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
342 		(arg)							\
343 	};								\
344 	SYSINIT(vnet_init_ ## ident, subsystem, order,			\
345 	    vnet_register_sysinit, &ident ## _vnet_init);		\
346 	SYSUNINIT(vnet_init_ ## ident, subsystem, order,		\
347 	    vnet_deregister_sysinit, &ident ## _vnet_init)
348 
349 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
350 	CTASSERT((subsystem) > SI_SUB_VNET &&				\
351 	    (subsystem) <= SI_SUB_VNET_DONE);				\
352 	static struct vnet_sysinit ident ## _vnet_uninit = {		\
353 		subsystem,						\
354 		order,							\
355 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
356 		(arg)							\
357 	};								\
358 	SYSINIT(vnet_uninit_ ## ident, subsystem, order,		\
359 	    vnet_register_sysuninit, &ident ## _vnet_uninit);		\
360 	SYSUNINIT(vnet_uninit_ ## ident, subsystem, order,		\
361 	    vnet_deregister_sysuninit, &ident ## _vnet_uninit)
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 #define	CURVNET_ASSERT_SET()						\
406 
407 #define	VNET_LIST_RLOCK()
408 #define	VNET_LIST_RLOCK_NOSLEEP()
409 #define	VNET_LIST_RUNLOCK()
410 #define	VNET_LIST_RUNLOCK_NOSLEEP()
411 #define	VNET_ITERATOR_DECL(arg)
412 #define	VNET_FOREACH(arg)	for (int _vn = 0; _vn == 0; _vn++)
413 
414 #define	IS_DEFAULT_VNET(arg)	1
415 #define	CRED_TO_VNET(cr)	NULL
416 #define	TD_TO_VNET(td)		NULL
417 #define	P_TO_VNET(p)		NULL
418 
419 /*
420  * Versions of the VNET macros that compile to normal global variables and
421  * standard sysctl definitions.
422  */
423 #define	VNET_NAME(n)		n
424 #define	VNET_DECLARE(t, n)	extern t n
425 #define	VNET_DEFINE(t, n)	struct _hack; t n
426 #define	VNET_DEFINE_STATIC(t, n)	static t n
427 #define	_VNET_PTR(b, n)		&VNET_NAME(n)
428 
429 /*
430  * Virtualized global variable accessor macros.
431  */
432 #define	VNET_VNET_PTR(vnet, n)		(&(n))
433 #define	VNET_VNET(vnet, n)		(n)
434 
435 #define	VNET_PTR(n)		(&(n))
436 #define	VNET(n)			(n)
437 
438 /*
439  * When VIMAGE isn't compiled into the kernel, VNET_SYSINIT/VNET_SYSUNINIT
440  * map into normal sysinits, which have the same ordering properties.
441  */
442 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
443 	SYSINIT(ident, subsystem, order, func, arg)
444 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
445 	SYSUNINIT(ident, subsystem, order, func, arg)
446 
447 /*
448  * Without VIMAGE revert to the default implementation.
449  */
450 #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
451 	(tag) = eventhandler_register(NULL, #name, func, arg, priority)
452 #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)	\
453 	eventhandler_register(NULL, #name, func, arg, priority)
454 #endif /* VIMAGE */
455 #endif /* _KERNEL */
456 
457 #endif /* !_NET_VNET_H_ */
458