xref: /freebsd/sys/net/vnet.h (revision 3cbb4cc200f8a0ad7ed08233425ea54524a21f1c)
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,						\
146     CTLFLAG_VNET | CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_NEEDGIANT,	\
147     NULL, 0, array ## _sysctl, "I", desc)
148 #endif /* SYSCTL_OID */
149 
150 #ifdef VIMAGE
151 #include <sys/lock.h>
152 #include <sys/proc.h>			/* for struct thread */
153 #include <sys/rwlock.h>
154 #include <sys/sx.h>
155 
156 /*
157  * Location of the kernel's 'set_vnet' linker set.
158  */
159 extern uintptr_t	*__start_set_vnet;
160 __GLOBL(__start_set_vnet);
161 extern uintptr_t	*__stop_set_vnet;
162 __GLOBL(__stop_set_vnet);
163 
164 #define	VNET_START	(uintptr_t)&__start_set_vnet
165 #define	VNET_STOP	(uintptr_t)&__stop_set_vnet
166 
167 /*
168  * Functions to allocate and destroy virtual network stacks.
169  */
170 struct vnet *vnet_alloc(void);
171 void	vnet_destroy(struct vnet *vnet);
172 
173 /*
174  * The current virtual network stack -- we may wish to move this to struct
175  * pcpu in the future.
176  */
177 #define	curvnet	curthread->td_vnet
178 
179 /*
180  * Various macros -- get and set the current network stack, but also
181  * assertions.
182  */
183 #if defined(INVARIANTS) || defined(VNET_DEBUG)
184 #define	VNET_ASSERT(exp, msg)	do {					\
185 	if (!(exp))							\
186 		panic msg;						\
187 } while (0)
188 #else
189 #define	VNET_ASSERT(exp, msg)	do {					\
190 } while (0)
191 #endif
192 
193 #ifdef VNET_DEBUG
194 void vnet_log_recursion(struct vnet *, const char *, int);
195 
196 #define	CURVNET_SET_QUIET(arg)						\
197 	VNET_ASSERT((arg) != NULL && (arg)->vnet_magic_n == VNET_MAGIC_N, \
198 	    ("CURVNET_SET at %s:%d %s() curvnet=%p vnet=%p",		\
199 	    __FILE__, __LINE__, __func__, curvnet, (arg)));		\
200 	struct vnet *saved_vnet = curvnet;				\
201 	const char *saved_vnet_lpush = curthread->td_vnet_lpush;	\
202 	curvnet = arg;							\
203 	curthread->td_vnet_lpush = __func__;
204 
205 #define	CURVNET_SET_VERBOSE(arg)					\
206 	CURVNET_SET_QUIET(arg)						\
207 	if (saved_vnet)							\
208 		vnet_log_recursion(saved_vnet, saved_vnet_lpush, __LINE__);
209 
210 #define	CURVNET_SET(arg)	CURVNET_SET_VERBOSE(arg)
211 
212 #define	CURVNET_RESTORE()						\
213 	VNET_ASSERT(curvnet != NULL && (saved_vnet == NULL ||		\
214 	    saved_vnet->vnet_magic_n == VNET_MAGIC_N),			\
215 	    ("CURVNET_RESTORE at %s:%d %s() curvnet=%p saved_vnet=%p",	\
216 	    __FILE__, __LINE__, __func__, curvnet, saved_vnet));	\
217 	curvnet = saved_vnet;						\
218 	curthread->td_vnet_lpush = saved_vnet_lpush;
219 #else /* !VNET_DEBUG */
220 
221 #define	CURVNET_SET_QUIET(arg)						\
222 	VNET_ASSERT((arg) != NULL && (arg)->vnet_magic_n == VNET_MAGIC_N, \
223 	    ("CURVNET_SET at %s:%d %s() curvnet=%p vnet=%p",		\
224 	    __FILE__, __LINE__, __func__, curvnet, (arg)));		\
225 	struct vnet *saved_vnet = curvnet;				\
226 	curvnet = arg;
227 
228 #define	CURVNET_SET_VERBOSE(arg)					\
229 	CURVNET_SET_QUIET(arg)
230 
231 #define	CURVNET_SET(arg)	CURVNET_SET_VERBOSE(arg)
232 
233 #define	CURVNET_RESTORE()						\
234 	VNET_ASSERT(curvnet != NULL && (saved_vnet == NULL ||		\
235 	    saved_vnet->vnet_magic_n == VNET_MAGIC_N),			\
236 	    ("CURVNET_RESTORE at %s:%d %s() curvnet=%p saved_vnet=%p",	\
237 	    __FILE__, __LINE__, __func__, curvnet, saved_vnet));	\
238 	curvnet = saved_vnet;
239 #endif /* VNET_DEBUG */
240 
241 extern struct vnet *vnet0;
242 #define	IS_DEFAULT_VNET(arg)	((arg) == vnet0)
243 
244 #define	CRED_TO_VNET(cr)	(cr)->cr_prison->pr_vnet
245 #define	TD_TO_VNET(td)		CRED_TO_VNET((td)->td_ucred)
246 #define	P_TO_VNET(p)		CRED_TO_VNET((p)->p_ucred)
247 
248 /*
249  * Global linked list of all virtual network stacks, along with read locks to
250  * access it.  If a caller may sleep while accessing the list, it must use
251  * the sleepable lock macros.
252  */
253 LIST_HEAD(vnet_list_head, vnet);
254 extern struct vnet_list_head vnet_head;
255 extern struct rwlock vnet_rwlock;
256 extern struct sx vnet_sxlock;
257 
258 #define	VNET_LIST_RLOCK()		sx_slock(&vnet_sxlock)
259 #define	VNET_LIST_RLOCK_NOSLEEP()	rw_rlock(&vnet_rwlock)
260 #define	VNET_LIST_RUNLOCK()		sx_sunlock(&vnet_sxlock)
261 #define	VNET_LIST_RUNLOCK_NOSLEEP()	rw_runlock(&vnet_rwlock)
262 
263 /*
264  * Iteration macros to walk the global list of virtual network stacks.
265  */
266 #define	VNET_ITERATOR_DECL(arg)	struct vnet *arg
267 #define	VNET_FOREACH(arg)	LIST_FOREACH((arg), &vnet_head, vnet_le)
268 
269 /*
270  * Virtual network stack memory allocator, which allows global variables to
271  * be automatically instantiated for each network stack instance.
272  */
273 #define	VNET_NAME(n)		vnet_entry_##n
274 #define	VNET_DECLARE(t, n)	extern t VNET_NAME(n)
275 /* struct _hack is to stop this from being used with static data */
276 #define	VNET_DEFINE(t, n)	\
277     struct _hack; t VNET_NAME(n) __section(VNET_SETNAME) __used
278 #if defined(KLD_MODULE) && (defined(__aarch64__) || defined(__riscv) \
279 		|| defined(__powerpc64__))
280 /*
281  * As with DPCPU_DEFINE_STATIC we are unable to mark this data as static
282  * in modules on some architectures.
283  */
284 #define	VNET_DEFINE_STATIC(t, n) \
285     t VNET_NAME(n) __section(VNET_SETNAME) __used
286 #else
287 #define	VNET_DEFINE_STATIC(t, n) \
288     static t VNET_NAME(n) __section(VNET_SETNAME) __used
289 #endif
290 #define	_VNET_PTR(b, n)		(__typeof(VNET_NAME(n))*)		\
291 				    ((b) + (uintptr_t)&VNET_NAME(n))
292 
293 #define	_VNET(b, n)		(*_VNET_PTR(b, n))
294 
295 /*
296  * Virtualized global variable accessor macros.
297  */
298 #define	VNET_VNET_PTR(vnet, n)		_VNET_PTR((vnet)->vnet_data_base, n)
299 #define	VNET_VNET(vnet, n)		(*VNET_VNET_PTR((vnet), n))
300 
301 #define	VNET_PTR(n)		VNET_VNET_PTR(curvnet, n)
302 #define	VNET(n)			VNET_VNET(curvnet, n)
303 
304 /*
305  * Virtual network stack allocator interfaces from the kernel linker.
306  */
307 void	*vnet_data_alloc(int size);
308 void	 vnet_data_copy(void *start, int size);
309 void	 vnet_data_free(void *start_arg, int size);
310 
311 /*
312  * Virtual sysinit mechanism, allowing network stack components to declare
313  * startup and shutdown methods to be run when virtual network stack
314  * instances are created and destroyed.
315  */
316 #include <sys/kernel.h>
317 
318 /*
319  * SYSINIT/SYSUNINIT variants that provide per-vnet constructors and
320  * destructors.
321  */
322 struct vnet_sysinit {
323 	enum sysinit_sub_id	subsystem;
324 	enum sysinit_elem_order	order;
325 	sysinit_cfunc_t		func;
326 	const void		*arg;
327 	TAILQ_ENTRY(vnet_sysinit) link;
328 };
329 
330 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
331 	CTASSERT((subsystem) > SI_SUB_VNET &&				\
332 	    (subsystem) <= SI_SUB_VNET_DONE);				\
333 	static struct vnet_sysinit ident ## _vnet_init = {		\
334 		subsystem,						\
335 		order,							\
336 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
337 		(arg)							\
338 	};								\
339 	SYSINIT(vnet_init_ ## ident, subsystem, order,			\
340 	    vnet_register_sysinit, &ident ## _vnet_init);		\
341 	SYSUNINIT(vnet_init_ ## ident, subsystem, order,		\
342 	    vnet_deregister_sysinit, &ident ## _vnet_init)
343 
344 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
345 	CTASSERT((subsystem) > SI_SUB_VNET &&				\
346 	    (subsystem) <= SI_SUB_VNET_DONE);				\
347 	static struct vnet_sysinit ident ## _vnet_uninit = {		\
348 		subsystem,						\
349 		order,							\
350 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
351 		(arg)							\
352 	};								\
353 	SYSINIT(vnet_uninit_ ## ident, subsystem, order,		\
354 	    vnet_register_sysuninit, &ident ## _vnet_uninit);		\
355 	SYSUNINIT(vnet_uninit_ ## ident, subsystem, order,		\
356 	    vnet_deregister_sysuninit, &ident ## _vnet_uninit)
357 
358 /*
359  * Run per-vnet sysinits or sysuninits during vnet creation/destruction.
360  */
361 void	 vnet_sysinit(void);
362 void	 vnet_sysuninit(void);
363 
364 /*
365  * Interfaces for managing per-vnet constructors and destructors.
366  */
367 void	vnet_register_sysinit(void *arg);
368 void	vnet_register_sysuninit(void *arg);
369 void	vnet_deregister_sysinit(void *arg);
370 void	vnet_deregister_sysuninit(void *arg);
371 
372 /*
373  * EVENTHANDLER(9) extensions.
374  */
375 #include <sys/eventhandler.h>
376 
377 void	vnet_global_eventhandler_iterator_func(void *, ...);
378 #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
379 do {									\
380 	if (IS_DEFAULT_VNET(curvnet)) {					\
381 		(tag) = vimage_eventhandler_register(NULL, #name, func,	\
382 		    arg, priority,					\
383 		    vnet_global_eventhandler_iterator_func);		\
384 	}								\
385 } while(0)
386 #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)	\
387 do {									\
388 	if (IS_DEFAULT_VNET(curvnet)) {					\
389 		vimage_eventhandler_register(NULL, #name, func,		\
390 		    arg, priority,					\
391 		    vnet_global_eventhandler_iterator_func);		\
392 	}								\
393 } while(0)
394 
395 #else /* !VIMAGE */
396 
397 /*
398  * Various virtual network stack macros compile to no-ops without VIMAGE.
399  */
400 #define	curvnet			NULL
401 
402 #define	VNET_ASSERT(exp, msg)
403 #define	CURVNET_SET(arg)
404 #define	CURVNET_SET_QUIET(arg)
405 #define	CURVNET_RESTORE()
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)
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