xref: /freebsd/sys/net/vnet.h (revision 9517e866259191fcd39434a97ad849a9b59b9b9f)
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 #ifdef VIMAGE
89 #include <sys/lock.h>
90 #include <sys/proc.h>			/* for struct thread */
91 #include <sys/rwlock.h>
92 #include <sys/sx.h>
93 
94 /*
95  * Functions to allocate and destroy virtual network stacks.
96  */
97 struct vnet *vnet_alloc(void);
98 void	vnet_destroy(struct vnet *vnet);
99 
100 /*
101  * The current virtual network stack -- we may wish to move this to struct
102  * pcpu in the future.
103  */
104 #define	curvnet	curthread->td_vnet
105 
106 /*
107  * Various macros -- get and set the current network stack, but also
108  * assertions.
109  */
110 #ifdef INVARIANTS
111 #define	VNET_DEBUG
112 #endif
113 #ifdef VNET_DEBUG
114 #define	VNET_ASSERT(condition)						\
115 	if (!(condition)) {						\
116 		printf("VNET_ASSERT @ %s:%d %s():\n",			\
117 			__FILE__, __LINE__, __FUNCTION__);		\
118 		panic(#condition);					\
119 	}
120 
121 #define	CURVNET_SET_QUIET(arg)						\
122 	VNET_ASSERT((arg)->vnet_magic_n == VNET_MAGIC_N);		\
123 	struct vnet *saved_vnet = curvnet;				\
124 	const char *saved_vnet_lpush = curthread->td_vnet_lpush;	\
125 	curvnet = arg;							\
126 	curthread->td_vnet_lpush = __FUNCTION__;
127 
128 #define	CURVNET_SET_VERBOSE(arg)					\
129 	CURVNET_SET_QUIET(arg)						\
130 	if (saved_vnet)							\
131 		printf("CURVNET_SET(%p) in %s() on cpu %d, prev %p in %s()\n", \
132 		       curvnet,	curthread->td_vnet_lpush, curcpu,	\
133 		       saved_vnet, saved_vnet_lpush);
134 
135 #define	CURVNET_SET(arg)	CURVNET_SET_VERBOSE(arg)
136 
137 #define	CURVNET_RESTORE()						\
138 	VNET_ASSERT(saved_vnet == NULL ||				\
139 		    saved_vnet->vnet_magic_n == VNET_MAGIC_N);		\
140 	curvnet = saved_vnet;						\
141 	curthread->td_vnet_lpush = saved_vnet_lpush;
142 #else /* !VNET_DEBUG */
143 #define	VNET_ASSERT(condition)
144 
145 #define	CURVNET_SET(arg)						\
146 	struct vnet *saved_vnet = curvnet;				\
147 	curvnet = arg;
148 
149 #define	CURVNET_SET_VERBOSE(arg)	CURVNET_SET(arg)
150 #define	CURVNET_SET_QUIET(arg)		CURVNET_SET(arg)
151 
152 #define	CURVNET_RESTORE()						\
153 	curvnet = saved_vnet;
154 #endif /* VNET_DEBUG */
155 
156 extern struct vnet *vnet0;
157 #define	IS_DEFAULT_VNET(arg)	((arg) == vnet0)
158 
159 #define	CRED_TO_VNET(cr)	(cr)->cr_prison->pr_vnet
160 #define	TD_TO_VNET(td)		CRED_TO_VNET((td)->td_ucred)
161 #define	P_TO_VNET(p)		CRED_TO_VNET((p)->p_ucred)
162 
163 /*
164  * Global linked list of all virtual network stacks, along with read locks to
165  * access it.  If a caller may sleep while accessing the list, it must use
166  * the sleepable lock macros.
167  */
168 LIST_HEAD(vnet_list_head, vnet);
169 extern struct vnet_list_head vnet_head;
170 extern struct rwlock vnet_rwlock;
171 extern struct sx vnet_sxlock;
172 
173 #define	VNET_LIST_RLOCK()		sx_slock(&vnet_sxlock)
174 #define	VNET_LIST_RLOCK_NOSLEEP()	rw_rlock(&vnet_rwlock)
175 #define	VNET_LIST_RUNLOCK()		sx_sunlock(&vnet_sxlock)
176 #define	VNET_LIST_RUNLOCK_NOSLEEP()	rw_runlock(&vnet_rwlock)
177 
178 /*
179  * Iteration macros to walk the global list of virtual network stacks.
180  */
181 #define	VNET_ITERATOR_DECL(arg)	struct vnet *arg
182 #define	VNET_FOREACH(arg)	LIST_FOREACH((arg), &vnet_head, vnet_le)
183 
184 /*
185  * Virtual network stack memory allocator, which allows global variables to
186  * be automatically instantiated for each network stack instance.
187  */
188 __asm__(
189 #if defined(__arm__)
190 	".section " VNET_SETNAME ", \"aw\", %progbits\n"
191 #else
192 	".section " VNET_SETNAME ", \"aw\", @progbits\n"
193 #endif
194 	"\t.p2align " __XSTRING(CACHE_LINE_SHIFT) "\n"
195 	"\t.previous");
196 
197 #define	VNET_NAME(n)		vnet_entry_##n
198 #define	VNET_DECLARE(t, n)	extern t VNET_NAME(n)
199 #define	VNET_DEFINE(t, n)	t VNET_NAME(n) __section(VNET_SETNAME) __used
200 #define	_VNET_PTR(b, n)		(__typeof(VNET_NAME(n))*)		\
201 				    ((b) + (uintptr_t)&VNET_NAME(n))
202 
203 #define	_VNET(b, n)		(*_VNET_PTR(b, n))
204 
205 /*
206  * Virtualized global variable accessor macros.
207  */
208 #define	VNET_VNET_PTR(vnet, n)		_VNET_PTR((vnet)->vnet_data_base, n)
209 #define	VNET_VNET(vnet, n)		(*VNET_VNET_PTR((vnet), n))
210 
211 #define	VNET_PTR(n)		VNET_VNET_PTR(curvnet, n)
212 #define	VNET(n)			VNET_VNET(curvnet, n)
213 
214 /*
215  * Virtual network stack allocator interfaces from the kernel linker.
216  */
217 void	*vnet_data_alloc(int size);
218 void	 vnet_data_copy(void *start, int size);
219 void	 vnet_data_free(void *start_arg, int size);
220 
221 /*
222  * Sysctl variants for vnet-virtualized global variables.  Include
223  * <sys/sysctl.h> to expose these definitions.
224  *
225  * Note: SYSCTL_PROC() handler functions will need to resolve pointer
226  * arguments themselves, if required.
227  */
228 #ifdef SYSCTL_OID
229 int	vnet_sysctl_handle_int(SYSCTL_HANDLER_ARGS);
230 int	vnet_sysctl_handle_opaque(SYSCTL_HANDLER_ARGS);
231 int	vnet_sysctl_handle_string(SYSCTL_HANDLER_ARGS);
232 int	vnet_sysctl_handle_uint(SYSCTL_HANDLER_ARGS);
233 
234 #define	SYSCTL_VNET_INT(parent, nbr, name, access, ptr, val, descr)	\
235 	SYSCTL_OID(parent, nbr, name, CTLTYPE_INT|CTLFLAG_MPSAFE|(access), \
236 	    ptr, val, vnet_sysctl_handle_int, "I", descr)
237 #define	SYSCTL_VNET_PROC(parent, nbr, name, access, ptr, arg, handler,	\
238 	    fmt, descr)							\
239 	SYSCTL_OID(parent, nbr, name, access, ptr, arg, handler, fmt,	\
240 	    descr)
241 #define	SYSCTL_VNET_STRING(parent, nbr, name, access, arg, len, descr)	\
242 	SYSCTL_OID(parent, nbr, name, CTLTYPE_STRING|(access), arg,	\
243 	    len, vnet_sysctl_handle_string, "A", descr)
244 #define	SYSCTL_VNET_STRUCT(parent, nbr, name, access, ptr, type, descr)	\
245 	SYSCTL_OID(parent, nbr, name, CTLTYPE_OPAQUE|(access), ptr,	\
246 	    sizeof(struct type), vnet_sysctl_handle_opaque, "S," #type,	\
247 	    descr)
248 #define	SYSCTL_VNET_UINT(parent, nbr, name, access, ptr, val, descr)	\
249 	SYSCTL_OID(parent, nbr, name, CTLTYPE_UINT|CTLFLAG_MPSAFE|(access), \
250 	    ptr, val, vnet_sysctl_handle_uint, "IU", descr)
251 #define	VNET_SYSCTL_ARG(req, arg1) do {					\
252 	if (arg1 != NULL)						\
253 		arg1 = (void *)(TD_TO_VNET((req)->td)->vnet_data_base +	\
254 		    (uintptr_t)(arg1));					\
255 } while (0)
256 #endif /* SYSCTL_OID */
257 
258 /*
259  * Virtual sysinit mechanism, allowing network stack components to declare
260  * startup and shutdown methods to be run when virtual network stack
261  * instances are created and destroyed.
262  */
263 #include <sys/kernel.h>
264 
265 /*
266  * SYSINIT/SYSUNINIT variants that provide per-vnet constructors and
267  * destructors.
268  */
269 struct vnet_sysinit {
270 	enum sysinit_sub_id	subsystem;
271 	enum sysinit_elem_order	order;
272 	sysinit_cfunc_t		func;
273 	const void		*arg;
274 	TAILQ_ENTRY(vnet_sysinit) link;
275 };
276 
277 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
278 	static struct vnet_sysinit ident ## _vnet_init = {		\
279 		subsystem,						\
280 		order,							\
281 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
282 		(arg)							\
283 	};								\
284 	SYSINIT(vnet_init_ ## ident, subsystem, order,			\
285 	    vnet_register_sysinit, &ident ## _vnet_init);		\
286 	SYSUNINIT(vnet_init_ ## ident, subsystem, order,		\
287 	    vnet_deregister_sysinit, &ident ## _vnet_init)
288 
289 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
290 	static struct vnet_sysinit ident ## _vnet_uninit = {		\
291 		subsystem,						\
292 		order,							\
293 		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
294 		(arg)							\
295 	};								\
296 	SYSINIT(vnet_uninit_ ## ident, subsystem, order,		\
297 	    vnet_register_sysuninit, &ident ## _vnet_uninit);		\
298 	SYSUNINIT(vnet_uninit_ ## ident, subsystem, order,		\
299 	    vnet_deregister_sysuninit, &ident ## _vnet_uninit)
300 
301 /*
302  * Run per-vnet sysinits or sysuninits during vnet creation/destruction.
303  */
304 void	 vnet_sysinit(void);
305 void	 vnet_sysuninit(void);
306 
307 /*
308  * Interfaces for managing per-vnet constructors and destructors.
309  */
310 void	vnet_register_sysinit(void *arg);
311 void	vnet_register_sysuninit(void *arg);
312 void	vnet_deregister_sysinit(void *arg);
313 void	vnet_deregister_sysuninit(void *arg);
314 
315 #else /* !VIMAGE */
316 
317 /*
318  * Various virtual network stack macros compile to no-ops without VIMAGE.
319  */
320 #define	curvnet			NULL
321 
322 #define	VNET_ASSERT(condition)
323 #define	CURVNET_SET(arg)
324 #define	CURVNET_SET_QUIET(arg)
325 #define	CURVNET_RESTORE()
326 
327 #define	VNET_LIST_RLOCK()
328 #define	VNET_LIST_RLOCK_NOSLEEP()
329 #define	VNET_LIST_RUNLOCK()
330 #define	VNET_LIST_RUNLOCK_NOSLEEP()
331 #define	VNET_ITERATOR_DECL(arg)
332 #define	VNET_FOREACH(arg)
333 
334 #define	IS_DEFAULT_VNET(arg)	1
335 #define	CRED_TO_VNET(cr)	NULL
336 #define	TD_TO_VNET(td)		NULL
337 #define	P_TO_VNET(p)		NULL
338 
339 /*
340  * Versions of the VNET macros that compile to normal global variables and
341  * standard sysctl definitions.
342  */
343 #define	VNET_NAME(n)		n
344 #define	VNET_DECLARE(t, n)	extern t n
345 #define	VNET_DEFINE(t, n)	t n
346 #define	_VNET_PTR(b, n)		&VNET_NAME(n)
347 
348 /*
349  * Virtualized global variable accessor macros.
350  */
351 #define	VNET_VNET_PTR(vnet, n)		(&(n))
352 #define	VNET_VNET(vnet, n)		(n)
353 
354 #define	VNET_PTR(n)		(&(n))
355 #define	VNET(n)			(n)
356 
357 /*
358  * When VIMAGE isn't compiled into the kernel, virtaulized SYSCTLs simply
359  * become normal SYSCTLs.
360  */
361 #ifdef SYSCTL_OID
362 #define	SYSCTL_VNET_INT(parent, nbr, name, access, ptr, val, descr)	\
363 	SYSCTL_INT(parent, nbr, name, access, ptr, val, descr)
364 #define	SYSCTL_VNET_PROC(parent, nbr, name, access, ptr, arg, handler,	\
365 	    fmt, descr)							\
366 	SYSCTL_PROC(parent, nbr, name, access, ptr, arg, handler, fmt,	\
367 	    descr)
368 #define	SYSCTL_VNET_STRING(parent, nbr, name, access, arg, len, descr)	\
369 	SYSCTL_STRING(parent, nbr, name, access, arg, len, descr)
370 #define	SYSCTL_VNET_STRUCT(parent, nbr, name, access, ptr, type, descr)	\
371 	SYSCTL_STRUCT(parent, nbr, name, access, ptr, type, descr)
372 #define	SYSCTL_VNET_UINT(parent, nbr, name, access, ptr, val, descr)	\
373 	SYSCTL_UINT(parent, nbr, name, access, ptr, val, descr)
374 #define	VNET_SYSCTL_ARG(req, arg1)
375 #endif /* SYSCTL_OID */
376 
377 /*
378  * When VIMAGE isn't compiled into the kernel, VNET_SYSINIT/VNET_SYSUNINIT
379  * map into normal sysinits, which have the same ordering properties.
380  */
381 #define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
382 	SYSINIT(ident, subsystem, order, func, arg)
383 #define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
384 	SYSUNINIT(ident, subsystem, order, func, arg)
385 
386 #endif /* VIMAGE */
387 #endif /* _KERNEL */
388 
389 #endif /* !_NET_VNET_H_ */
390