xref: /freebsd/sys/net/vnet.h (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
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 <machine/param.h>	/* for CACHE_LINE_SIZE */
67 #include <sys/queue.h>
68 
69 struct vnet {
70 	LIST_ENTRY(vnet)	 vnet_le;	/* all vnets list */
71 	u_int			 vnet_magic_n;
72 	u_int			 vnet_ifcnt;
73 	u_int			 vnet_sockcnt;
74 	u_int			 vnet_state;	/* SI_SUB_* */
75 	void			*vnet_data_mem;
76 	uintptr_t		 vnet_data_base;
77 	bool			 vnet_shutdown;	/* Shutdown in progress. */
78 } __aligned(CACHE_LINE_SIZE);
79 #define	VNET_MAGIC_N	0x5e4a6f28
80 
81 /*
82  * These two virtual network stack allocator definitions are also required
83  * for libkvm so that it can evaluate virtualized global variables.
84  */
85 #define	VNET_SETNAME		"set_vnet"
86 #define	VNET_SYMPREFIX		"vnet_entry_"
87 #endif
88 
89 #ifdef _KERNEL
90 
91 #define	VNET_PCPUSTAT_DECLARE(type, name)	\
92     VNET_DECLARE(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
93 
94 #define	VNET_PCPUSTAT_DEFINE(type, name)	\
95     VNET_DEFINE(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
96 #define	VNET_PCPUSTAT_DEFINE_STATIC(type, name)	\
97     VNET_DEFINE_STATIC(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
98 
99 #define	VNET_PCPUSTAT_ALLOC(name, wait)	\
100     COUNTER_ARRAY_ALLOC(VNET(name), \
101 	sizeof(VNET(name)) / sizeof(counter_u64_t), (wait))
102 
103 #define	VNET_PCPUSTAT_FREE(name)	\
104     COUNTER_ARRAY_FREE(VNET(name), sizeof(VNET(name)) / sizeof(counter_u64_t))
105 
106 #define	VNET_PCPUSTAT_ADD(type, name, f, v)	\
107     counter_u64_add(VNET(name)[offsetof(type, f) / sizeof(uint64_t)], (v))
108 
109 #define	VNET_PCPUSTAT_FETCH(type, name, f)	\
110     counter_u64_fetch(VNET(name)[offsetof(type, f) / sizeof(uint64_t)])
111 
112 #define	VNET_PCPUSTAT_SYSINIT(name)	\
113 static void				\
114 vnet_##name##_init(const void *unused)	\
115 {					\
116 	VNET_PCPUSTAT_ALLOC(name, M_WAITOK);	\
117 }					\
118 VNET_SYSINIT(vnet_ ## name ## _init, SI_SUB_INIT_IF,			\
119     SI_ORDER_FIRST, vnet_ ## name ## _init, NULL)
120 
121 #define	VNET_PCPUSTAT_SYSUNINIT(name)					\
122 static void								\
123 vnet_##name##_uninit(const void *unused)				\
124 {									\
125 	VNET_PCPUSTAT_FREE(name);					\
126 }									\
127 VNET_SYSUNINIT(vnet_ ## name ## _uninit, SI_SUB_INIT_IF,		\
128     SI_ORDER_FIRST, vnet_ ## name ## _uninit, NULL)
129 
130 #ifdef SYSCTL_OID
131 #define	SYSCTL_VNET_PCPUSTAT(parent, nbr, name, type, array, desc)	\
132 static int								\
133 array##_sysctl(SYSCTL_HANDLER_ARGS)					\
134 {									\
135 	type s;								\
136 	CTASSERT((sizeof(type) / sizeof(uint64_t)) ==			\
137 	    (sizeof(VNET(array)) / sizeof(counter_u64_t)));		\
138 	COUNTER_ARRAY_COPY(VNET(array), &s, sizeof(type) / sizeof(uint64_t));\
139 	if (req->newptr)						\
140 		COUNTER_ARRAY_ZERO(VNET(array),				\
141 		    sizeof(type) / sizeof(uint64_t));			\
142 	return (SYSCTL_OUT(req, &s, sizeof(type)));			\
143 }									\
144 SYSCTL_PROC(parent, nbr, name,						\
145     CTLFLAG_VNET | CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_NEEDGIANT,	\
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 #define	CURVNET_ASSERT_SET()						\
241 	VNET_ASSERT(curvnet != NULL, ("vnet is not set at %s:%d %s()",  \
242 	    __FILE__, __LINE__, __func__))
243 
244 extern struct vnet *vnet0;
245 #define	IS_DEFAULT_VNET(arg)	((arg) == vnet0)
246 
247 #define	CRED_TO_VNET(cr)	(cr)->cr_prison->pr_vnet
248 #define	TD_TO_VNET(td)		CRED_TO_VNET((td)->td_ucred)
249 #define	P_TO_VNET(p)		CRED_TO_VNET((p)->p_ucred)
250 
251 /*
252  * Global linked list of all virtual network stacks, along with read locks to
253  * access it.  If a caller may sleep while accessing the list, it must use
254  * the sleepable lock macros.
255  */
256 LIST_HEAD(vnet_list_head, vnet);
257 extern struct vnet_list_head vnet_head;
258 extern struct rwlock vnet_rwlock;
259 extern struct sx vnet_sxlock;
260 
261 #define	VNET_LIST_RLOCK()		sx_slock(&vnet_sxlock)
262 #define	VNET_LIST_RLOCK_NOSLEEP()	rw_rlock(&vnet_rwlock)
263 #define	VNET_LIST_RUNLOCK()		sx_sunlock(&vnet_sxlock)
264 #define	VNET_LIST_RUNLOCK_NOSLEEP()	rw_runlock(&vnet_rwlock)
265 
266 /*
267  * Iteration macros to walk the global list of virtual network stacks.
268  */
269 #define	VNET_ITERATOR_DECL(arg)	struct vnet *arg
270 #define	VNET_FOREACH(arg)	LIST_FOREACH((arg), &vnet_head, vnet_le)
271 
272 /*
273  * Virtual network stack memory allocator, which allows global variables to
274  * be automatically instantiated for each network stack instance.
275  */
276 #define	VNET_NAME(n)		vnet_entry_##n
277 #define	VNET_DECLARE(t, n)	extern t VNET_NAME(n)
278 /* struct _hack is to stop this from being used with static data */
279 #define	VNET_DEFINE(t, n)	\
280     struct _hack; t VNET_NAME(n) __section(VNET_SETNAME) __used
281 #if defined(KLD_MODULE) && (defined(__aarch64__) || defined(__riscv) \
282 		|| defined(__powerpc64__) || defined(__i386__))
283 /*
284  * As with DPCPU_DEFINE_STATIC we are unable to mark this data as static
285  * in modules on some architectures.
286  */
287 #define	VNET_DEFINE_STATIC(t, n) \
288     t VNET_NAME(n) __section(VNET_SETNAME) __used
289 #else
290 #define	VNET_DEFINE_STATIC(t, n) \
291     static t VNET_NAME(n) __section(VNET_SETNAME) __used
292 #endif
293 #define	_VNET_PTR(b, n)		(__typeof(VNET_NAME(n))*)		\
294 				    ((b) + (uintptr_t)&VNET_NAME(n))
295 
296 #define	_VNET(b, n)		(*_VNET_PTR(b, n))
297 
298 /*
299  * Virtualized global variable accessor macros.
300  */
301 #define	VNET_VNET_PTR(vnet, n)		_VNET_PTR((vnet)->vnet_data_base, n)
302 #define	VNET_VNET(vnet, n)		(*VNET_VNET_PTR((vnet), n))
303 
304 #define	VNET_PTR(n)		VNET_VNET_PTR(curvnet, n)
305 #define	VNET(n)			VNET_VNET(curvnet, n)
306 
307 /*
308  * Virtual network stack allocator interfaces from the kernel linker.
309  */
310 void	*vnet_data_alloc(int size);
311 void	 vnet_data_copy(void *start, int size);
312 void	 vnet_data_free(void *start_arg, int size);
313 
314 /*
315  * Interfaces to manipulate the initial values of virtualized global variables.
316  */
317 void    vnet_save_init(void *, size_t);
318 void    vnet_restore_init(void *, size_t);
319 
320 /*
321  * Virtual sysinit mechanism, allowing network stack components to declare
322  * startup and shutdown methods to be run when virtual network stack
323  * instances are created and destroyed.
324  */
325 #include <sys/kernel.h>
326 
327 /*
328  * SYSINIT/SYSUNINIT variants that provide per-vnet constructors and
329  * destructors.
330  */
331 struct vnet_sysinit {
332 	enum sysinit_sub_id	subsystem;
333 	enum sysinit_elem_order	order;
334 	sysinit_cfunc_t		func;
335 	const void		*arg;
336 	TAILQ_ENTRY(vnet_sysinit) link;
337 };
338 
339 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
340 	CTASSERT((subsystem) > SI_SUB_VNET &&				\
341 	    (subsystem) <= SI_SUB_VNET_DONE);				\
342 	static struct vnet_sysinit ident ## _vnet_init = {		\
343 		subsystem,						\
344 		order,							\
345 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
346 		(arg)							\
347 	};								\
348 	SYSINIT(vnet_init_ ## ident, subsystem, order,			\
349 	    vnet_register_sysinit, &ident ## _vnet_init);		\
350 	SYSUNINIT(vnet_init_ ## ident, subsystem, order,		\
351 	    vnet_deregister_sysinit, &ident ## _vnet_init)
352 
353 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
354 	CTASSERT((subsystem) > SI_SUB_VNET &&				\
355 	    (subsystem) <= SI_SUB_VNET_DONE);				\
356 	static struct vnet_sysinit ident ## _vnet_uninit = {		\
357 		subsystem,						\
358 		order,							\
359 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
360 		(arg)							\
361 	};								\
362 	SYSINIT(vnet_uninit_ ## ident, subsystem, order,		\
363 	    vnet_register_sysuninit, &ident ## _vnet_uninit);		\
364 	SYSUNINIT(vnet_uninit_ ## ident, subsystem, order,		\
365 	    vnet_deregister_sysuninit, &ident ## _vnet_uninit)
366 
367 /*
368  * Interfaces for managing per-vnet constructors and destructors.
369  */
370 void	vnet_register_sysinit(void *arg);
371 void	vnet_register_sysuninit(void *arg);
372 void	vnet_deregister_sysinit(void *arg);
373 void	vnet_deregister_sysuninit(void *arg);
374 
375 /*
376  * EVENTHANDLER(9) extensions.
377  */
378 #include <sys/eventhandler.h>
379 
380 void	vnet_global_eventhandler_iterator_func(void *, ...);
381 #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
382 do {									\
383 	if (IS_DEFAULT_VNET(curvnet)) {					\
384 		(tag) = vimage_eventhandler_register(NULL, #name, func,	\
385 		    arg, priority,					\
386 		    vnet_global_eventhandler_iterator_func);		\
387 	}								\
388 } while(0)
389 #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)	\
390 do {									\
391 	if (IS_DEFAULT_VNET(curvnet)) {					\
392 		vimage_eventhandler_register(NULL, #name, func,		\
393 		    arg, priority,					\
394 		    vnet_global_eventhandler_iterator_func);		\
395 	}								\
396 } while(0)
397 
398 #else /* !VIMAGE */
399 
400 /*
401  * Various virtual network stack macros compile to no-ops without VIMAGE.
402  */
403 #define	curvnet			NULL
404 
405 #define	VNET_ASSERT(exp, msg)
406 #define	CURVNET_SET(arg)
407 #define	CURVNET_SET_QUIET(arg)
408 #define	CURVNET_RESTORE()
409 #define	CURVNET_ASSERT_SET()						\
410 
411 #define	VNET_LIST_RLOCK()
412 #define	VNET_LIST_RLOCK_NOSLEEP()
413 #define	VNET_LIST_RUNLOCK()
414 #define	VNET_LIST_RUNLOCK_NOSLEEP()
415 #define	VNET_ITERATOR_DECL(arg)
416 #define	VNET_FOREACH(arg)	for (int _vn = 0; _vn == 0; _vn++)
417 
418 #define	IS_DEFAULT_VNET(arg)	1
419 #define	CRED_TO_VNET(cr)	NULL
420 #define	TD_TO_VNET(td)		NULL
421 #define	P_TO_VNET(p)		NULL
422 
423 /*
424  * Versions of the VNET macros that compile to normal global variables and
425  * standard sysctl definitions.
426  */
427 #define	VNET_NAME(n)		n
428 #define	VNET_DECLARE(t, n)	extern t n
429 #define	VNET_DEFINE(t, n)	struct _hack; t n
430 #define	VNET_DEFINE_STATIC(t, n)	static t n
431 #define	_VNET_PTR(b, n)		&VNET_NAME(n)
432 
433 /*
434  * Virtualized global variable accessor macros.
435  */
436 #define	VNET_VNET_PTR(vnet, n)		(&(n))
437 #define	VNET_VNET(vnet, n)		(n)
438 
439 #define	VNET_PTR(n)		(&(n))
440 #define	VNET(n)			(n)
441 
442 /*
443  * When VIMAGE isn't compiled into the kernel, VNET_SYSINIT/VNET_SYSUNINIT
444  * map into normal sysinits, which have the same ordering properties.
445  */
446 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
447 	SYSINIT(ident, subsystem, order, func, arg)
448 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
449 	SYSUNINIT(ident, subsystem, order, func, arg)
450 
451 /*
452  * Without VIMAGE revert to the default implementation.
453  */
454 #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
455 	(tag) = eventhandler_register(NULL, #name, func, arg, priority)
456 #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)	\
457 	eventhandler_register(NULL, #name, func, arg, priority)
458 #endif /* VIMAGE */
459 #endif /* _KERNEL */
460 
461 #endif /* !_NET_VNET_H_ */
462