sys/net/vnet.h

   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 #define VNET_PCPUSTAT_DECLARE(type, name)       \
  89     VNET_DECLARE(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
  90
  91 #define VNET_PCPUSTAT_DEFINE(type, name)        \
  92     VNET_DEFINE(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
  93
  94 #define VNET_PCPUSTAT_ALLOC(name, wait) \
  95     COUNTER_ARRAY_ALLOC(VNET(name), \
  96         sizeof(VNET(name)) / sizeof(counter_u64_t), (wait))
  97
  98 #define VNET_PCPUSTAT_FREE(name)        \
  99     COUNTER_ARRAY_FREE(VNET(name), sizeof(VNET(name)) / sizeof(counter_u64_t))
 100
 101 #define VNET_PCPUSTAT_ADD(type, name, f, v)     \
 102     counter_u64_add(VNET(name)[offsetof(type, f) / sizeof(uint64_t)], (v))
 103
 104 #define VNET_PCPUSTAT_SYSINIT(name)     \
 105 static void                             \
 106 vnet_##name##_init(const void *unused)  \
 107 {                                       \
 108         VNET_PCPUSTAT_ALLOC(name, M_WAITOK);    \
 109 }                                       \
 110 VNET_SYSINIT(vnet_ ## name ## _init, SI_SUB_PROTO_IFATTACHDOMAIN,       \
 111     SI_ORDER_ANY, vnet_ ## name ## _init, NULL)
 112
 113 #define VNET_PCPUSTAT_SYSUNINIT(name)                                   \
 114 static void                                                             \
 115 vnet_##name##_uninit(const void *unused)                                \
 116 {                                                                       \
 117         VNET_PCPUSTAT_FREE(name);                                       \
 118 }                                                                       \
 119 VNET_SYSUNINIT(vnet_ ## name ## _uninit, SI_SUB_PROTO_IFATTACHDOMAIN,   \
 120     SI_ORDER_ANY, vnet_ ## name ## _uninit, NULL)
 121
 122 #define SYSCTL_VNET_PCPUSTAT(parent, nbr, name, type, array, desc)      \
 123 static int                                                              \
 124 array##_sysctl(SYSCTL_HANDLER_ARGS)                                     \
 125 {                                                                       \
 126         type s;                                                         \
 127         CTASSERT((sizeof(type) / sizeof(uint64_t)) ==                   \
 128             (sizeof(VNET(array)) / sizeof(counter_u64_t)));             \
 129         COUNTER_ARRAY_COPY(VNET(array), &s, sizeof(type) / sizeof(uint64_t));\
 130         if (req->newptr)                                                \
 131                 COUNTER_ARRAY_ZERO(VNET(array),                         \
 132                     sizeof(type) / sizeof(uint64_t));                   \
 133         return (SYSCTL_OUT(req, &s, sizeof(type)));                     \
 134 }                                                                       \
 135 SYSCTL_VNET_PROC(parent, nbr, name, CTLTYPE_OPAQUE | CTLFLAG_RW, NULL,  \
 136     0, array ## _sysctl, "I", desc)
 137
 138 #ifdef VIMAGE
 139 #include <sys/lock.h>
 140 #include <sys/proc.h>                   /* for struct thread */
 141 #include <sys/rwlock.h>
 142 #include <sys/sx.h>
 143
 144 /*
 145  * Location of the kernel's 'set_vnet' linker set.
 146  */
 147 extern uintptr_t        *__start_set_vnet;
 148 __GLOBL(__start_set_vnet);
 149 extern uintptr_t        *__stop_set_vnet;
 150 __GLOBL(__stop_set_vnet);
 151
 152 #define VNET_START      (uintptr_t)&__start_set_vnet
 153 #define VNET_STOP       (uintptr_t)&__stop_set_vnet
 154
 155 /*
 156  * Functions to allocate and destroy virtual network stacks.
 157  */
 158 struct vnet *vnet_alloc(void);
 159 void    vnet_destroy(struct vnet *vnet);
 160
 161 /*
 162  * The current virtual network stack -- we may wish to move this to struct
 163  * pcpu in the future.
 164  */
 165 #define curvnet curthread->td_vnet
 166
 167 /*
 168  * Various macros -- get and set the current network stack, but also
 169  * assertions.
 170  */
 171 #if defined(INVARIANTS) || defined(VNET_DEBUG)
 172 #define VNET_ASSERT(exp, msg)   do {                                    \
 173         if (!(exp))                                                     \
 174                 panic msg;                                              \
 175 } while (0)
 176 #else
 177 #define VNET_ASSERT(exp, msg)   do {                                    \
 178 } while (0)
 179 #endif
 180
 181 #ifdef VNET_DEBUG
 182 void vnet_log_recursion(struct vnet *, const char *, int);
 183
 184 #define CURVNET_SET_QUIET(arg)                                          \
 185         VNET_ASSERT((arg) != NULL && (arg)->vnet_magic_n == VNET_MAGIC_N, \
 186             ("CURVNET_SET at %s:%d %s() curvnet=%p vnet=%p",            \
 187             __FILE__, __LINE__, __func__, curvnet, (arg)));             \
 188         struct vnet *saved_vnet = curvnet;                              \
 189         const char *saved_vnet_lpush = curthread->td_vnet_lpush;        \
 190         curvnet = arg;                                                  \
 191         curthread->td_vnet_lpush = __func__;
 192
 193 #define CURVNET_SET_VERBOSE(arg)                                        \
 194         CURVNET_SET_QUIET(arg)                                          \
 195         if (saved_vnet)                                                 \
 196                 vnet_log_recursion(saved_vnet, saved_vnet_lpush, __LINE__);
 197
 198 #define CURVNET_SET(arg)        CURVNET_SET_VERBOSE(arg)
 199
 200 #define CURVNET_RESTORE()                                               \
 201         VNET_ASSERT(curvnet != NULL && (saved_vnet == NULL ||           \
 202             saved_vnet->vnet_magic_n == VNET_MAGIC_N),                  \
 203             ("CURVNET_RESTORE at %s:%d %s() curvnet=%p saved_vnet=%p",  \
 204             __FILE__, __LINE__, __func__, curvnet, saved_vnet));        \
 205         curvnet = saved_vnet;                                           \
 206         curthread->td_vnet_lpush = saved_vnet_lpush;
 207 #else /* !VNET_DEBUG */
 208
 209 #define CURVNET_SET_QUIET(arg)                                          \
 210         VNET_ASSERT((arg) != NULL && (arg)->vnet_magic_n == VNET_MAGIC_N, \
 211             ("CURVNET_SET at %s:%d %s() curvnet=%p vnet=%p",            \
 212             __FILE__, __LINE__, __func__, curvnet, (arg)));             \
 213         struct vnet *saved_vnet = curvnet;                              \
 214         curvnet = arg;
 215
 216 #define CURVNET_SET_VERBOSE(arg)                                        \
 217         CURVNET_SET_QUIET(arg)
 218
 219 #define CURVNET_SET(arg)        CURVNET_SET_VERBOSE(arg)
 220
 221 #define CURVNET_RESTORE()                                               \
 222         VNET_ASSERT(curvnet != NULL && (saved_vnet == NULL ||           \
 223             saved_vnet->vnet_magic_n == VNET_MAGIC_N),                  \
 224             ("CURVNET_RESTORE at %s:%d %s() curvnet=%p saved_vnet=%p",  \
 225             __FILE__, __LINE__, __func__, curvnet, saved_vnet));        \
 226         curvnet = saved_vnet;
 227 #endif /* VNET_DEBUG */
 228
 229 extern struct vnet *vnet0;
 230 #define IS_DEFAULT_VNET(arg)    ((arg) == vnet0)
 231
 232 #define CRED_TO_VNET(cr)        (cr)->cr_prison->pr_vnet
 233 #define TD_TO_VNET(td)          CRED_TO_VNET((td)->td_ucred)
 234 #define P_TO_VNET(p)            CRED_TO_VNET((p)->p_ucred)
 235
 236 /*
 237  * Global linked list of all virtual network stacks, along with read locks to
 238  * access it.  If a caller may sleep while accessing the list, it must use
 239  * the sleepable lock macros.
 240  */
 241 LIST_HEAD(vnet_list_head, vnet);
 242 extern struct vnet_list_head vnet_head;
 243 extern struct rwlock vnet_rwlock;
 244 extern struct sx vnet_sxlock;
 245
 246 #define VNET_LIST_RLOCK()               sx_slock(&vnet_sxlock)
 247 #define VNET_LIST_RLOCK_NOSLEEP()       rw_rlock(&vnet_rwlock)
 248 #define VNET_LIST_RUNLOCK()             sx_sunlock(&vnet_sxlock)
 249 #define VNET_LIST_RUNLOCK_NOSLEEP()     rw_runlock(&vnet_rwlock)
 250
 251 /*
 252  * Iteration macros to walk the global list of virtual network stacks.
 253  */
 254 #define VNET_ITERATOR_DECL(arg) struct vnet *arg
 255 #define VNET_FOREACH(arg)       LIST_FOREACH((arg), &vnet_head, vnet_le)
 256
 257 /*
 258  * Virtual network stack memory allocator, which allows global variables to
 259  * be automatically instantiated for each network stack instance.
 260  */
 261 #define VNET_NAME(n)            vnet_entry_##n
 262 #define VNET_DECLARE(t, n)      extern t VNET_NAME(n)
 263 #define VNET_DEFINE(t, n)       t VNET_NAME(n) __section(VNET_SETNAME) __used
 264 #define _VNET_PTR(b, n)         (__typeof(VNET_NAME(n))*)               \
 265                                     ((b) + (uintptr_t)&VNET_NAME(n))
 266
 267 #define _VNET(b, n)             (*_VNET_PTR(b, n))
 268
 269 /*
 270  * Virtualized global variable accessor macros.
 271  */
 272 #define VNET_VNET_PTR(vnet, n)          _VNET_PTR((vnet)->vnet_data_base, n)
 273 #define VNET_VNET(vnet, n)              (*VNET_VNET_PTR((vnet), n))
 274
 275 #define VNET_PTR(n)             VNET_VNET_PTR(curvnet, n)
 276 #define VNET(n)                 VNET_VNET(curvnet, n)
 277
 278 /*
 279  * Virtual network stack allocator interfaces from the kernel linker.
 280  */
 281 void    *vnet_data_alloc(int size);
 282 void     vnet_data_copy(void *start, int size);
 283 void     vnet_data_free(void *start_arg, int size);
 284
 285 /*
 286  * Sysctl variants for vnet-virtualized global variables.  Include
 287  * <sys/sysctl.h> to expose these definitions.
 288  *
 289  * Note: SYSCTL_PROC() handler functions will need to resolve pointer
 290  * arguments themselves, if required.
 291  */
 292 #ifdef SYSCTL_OID
 293 #define SYSCTL_VNET_INT(parent, nbr, name, access, ptr, val, descr)     \
 294         SYSCTL_OID(parent, nbr, name,                                   \
 295             CTLTYPE_INT|CTLFLAG_MPSAFE|CTLFLAG_VNET|(access),           \
 296             ptr, val, sysctl_handle_int, "I", descr)
 297 #define SYSCTL_VNET_PROC(parent, nbr, name, access, ptr, arg, handler,  \
 298             fmt, descr)                                                 \
 299         CTASSERT(((access) & CTLTYPE) != 0);                            \
 300         SYSCTL_OID(parent, nbr, name, CTLFLAG_VNET|(access), ptr, arg,  \
 301             handler, fmt, descr)
 302 #define SYSCTL_VNET_OPAQUE(parent, nbr, name, access, ptr, len, fmt,    \
 303             descr)                                                      \
 304         SYSCTL_OID(parent, nbr, name,                                   \
 305             CTLTYPE_OPAQUE|CTLFLAG_VNET|(access), ptr, len,             \
 306             sysctl_handle_opaque, fmt, descr)
 307 #define SYSCTL_VNET_STRING(parent, nbr, name, access, arg, len, descr)  \
 308         SYSCTL_OID(parent, nbr, name,                                   \
 309             CTLTYPE_STRING|CTLFLAG_VNET|(access),                       \
 310             arg, len, sysctl_handle_string, "A", descr)
 311 #define SYSCTL_VNET_STRUCT(parent, nbr, name, access, ptr, type, descr) \
 312         SYSCTL_OID(parent, nbr, name,                                   \
 313             CTLTYPE_OPAQUE|CTLFLAG_VNET|(access), ptr,                  \
 314             sizeof(struct type), sysctl_handle_opaque, "S," #type,      \
 315             descr)
 316 #define SYSCTL_VNET_UINT(parent, nbr, name, access, ptr, val, descr)    \
 317         SYSCTL_OID(parent, nbr, name,                                   \
 318             CTLTYPE_UINT|CTLFLAG_MPSAFE|CTLFLAG_VNET|(access),          \
 319             ptr, val, sysctl_handle_int, "IU", descr)
 320 #define VNET_SYSCTL_ARG(req, arg1) do {                                 \
 321         if (arg1 != NULL)                                               \
 322                 arg1 = (void *)(TD_TO_VNET((req)->td)->vnet_data_base + \
 323                     (uintptr_t)(arg1));                                 \
 324 } while (0)
 325 #endif /* SYSCTL_OID */
 326
 327 /*
 328  * Virtual sysinit mechanism, allowing network stack components to declare
 329  * startup and shutdown methods to be run when virtual network stack
 330  * instances are created and destroyed.
 331  */
 332 #include <sys/kernel.h>
 333
 334 /*
 335  * SYSINIT/SYSUNINIT variants that provide per-vnet constructors and
 336  * destructors.
 337  */
 338 struct vnet_sysinit {
 339         enum sysinit_sub_id     subsystem;
 340         enum sysinit_elem_order order;
 341         sysinit_cfunc_t         func;
 342         const void              *arg;
 343         TAILQ_ENTRY(vnet_sysinit) link;
 344 };
 345
 346 #define VNET_SYSINIT(ident, subsystem, order, func, arg)                \
 347         static struct vnet_sysinit ident ## _vnet_init = {              \
 348                 subsystem,                                              \
 349                 order,                                                  \
 350                 (sysinit_cfunc_t)(sysinit_nfunc_t)func,                 \
 351                 (arg)                                                   \
 352         };                                                              \
 353         SYSINIT(vnet_init_ ## ident, subsystem, order,                  \
 354             vnet_register_sysinit, &ident ## _vnet_init);               \
 355         SYSUNINIT(vnet_init_ ## ident, subsystem, order,                \
 356             vnet_deregister_sysinit, &ident ## _vnet_init)
 357
 358 #define VNET_SYSUNINIT(ident, subsystem, order, func, arg)              \
 359         static struct vnet_sysinit ident ## _vnet_uninit = {            \
 360                 subsystem,                                              \
 361                 order,                                                  \
 362                 (sysinit_cfunc_t)(sysinit_nfunc_t)func,                 \
 363                 (arg)                                                   \
 364         };                                                              \
 365         SYSINIT(vnet_uninit_ ## ident, subsystem, order,                \
 366             vnet_register_sysuninit, &ident ## _vnet_uninit);           \
 367         SYSUNINIT(vnet_uninit_ ## ident, subsystem, order,              \
 368             vnet_deregister_sysuninit, &ident ## _vnet_uninit)
 369
 370 /*
 371  * Run per-vnet sysinits or sysuninits during vnet creation/destruction.
 372  */
 373 void     vnet_sysinit(void);
 374 void     vnet_sysuninit(void);
 375
 376 /*
 377  * Interfaces for managing per-vnet constructors and destructors.
 378  */
 379 void    vnet_register_sysinit(void *arg);
 380 void    vnet_register_sysuninit(void *arg);
 381 void    vnet_deregister_sysinit(void *arg);
 382 void    vnet_deregister_sysuninit(void *arg);
 383
 384 /*
 385  * EVENTHANDLER(9) extensions.
 386  */
 387 #include <sys/eventhandler.h>
 388
 389 void    vnet_global_eventhandler_iterator_func(void *, ...);
 390 #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
 391 do {                                                                    \
 392         if (IS_DEFAULT_VNET(curvnet)) {                                 \
 393                 (tag) = vimage_eventhandler_register(NULL, #name, func, \
 394                     arg, priority,                                      \
 395                     vnet_global_eventhandler_iterator_func);            \
 396         }                                                               \
 397 } while(0)
 398 #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)    \
 399 do {                                                                    \
 400         if (IS_DEFAULT_VNET(curvnet)) {                                 \
 401                 vimage_eventhandler_register(NULL, #name, func,         \
 402                     arg, priority,                                      \
 403                     vnet_global_eventhandler_iterator_func);            \
 404         }                                                               \
 405 } while(0)
 406
 407 #else /* !VIMAGE */
 408
 409 /*
 410  * Various virtual network stack macros compile to no-ops without VIMAGE.
 411  */
 412 #define curvnet                 NULL
 413
 414 #define VNET_ASSERT(exp, msg)
 415 #define CURVNET_SET(arg)
 416 #define CURVNET_SET_QUIET(arg)
 417 #define CURVNET_RESTORE()
 418
 419 #define VNET_LIST_RLOCK()
 420 #define VNET_LIST_RLOCK_NOSLEEP()
 421 #define VNET_LIST_RUNLOCK()
 422 #define VNET_LIST_RUNLOCK_NOSLEEP()
 423 #define VNET_ITERATOR_DECL(arg)
 424 #define VNET_FOREACH(arg)
 425
 426 #define IS_DEFAULT_VNET(arg)    1
 427 #define CRED_TO_VNET(cr)        NULL
 428 #define TD_TO_VNET(td)          NULL
 429 #define P_TO_VNET(p)            NULL
 430
 431 /*
 432  * Versions of the VNET macros that compile to normal global variables and
 433  * standard sysctl definitions.
 434  */
 435 #define VNET_NAME(n)            n
 436 #define VNET_DECLARE(t, n)      extern t n
 437 #define VNET_DEFINE(t, n)       t n
 438 #define _VNET_PTR(b, n)         &VNET_NAME(n)
 439
 440 /*
 441  * Virtualized global variable accessor macros.
 442  */
 443 #define VNET_VNET_PTR(vnet, n)          (&(n))
 444 #define VNET_VNET(vnet, n)              (n)
 445
 446 #define VNET_PTR(n)             (&(n))
 447 #define VNET(n)                 (n)
 448
 449 /*
 450  * When VIMAGE isn't compiled into the kernel, virtaulized SYSCTLs simply
 451  * become normal SYSCTLs.
 452  */
 453 #ifdef SYSCTL_OID
 454 #define SYSCTL_VNET_INT(parent, nbr, name, access, ptr, val, descr)     \
 455         SYSCTL_INT(parent, nbr, name, access, ptr, val, descr)
 456 #define SYSCTL_VNET_PROC(parent, nbr, name, access, ptr, arg, handler,  \
 457             fmt, descr)                                                 \
 458         SYSCTL_PROC(parent, nbr, name, access, ptr, arg, handler, fmt,  \
 459             descr)
 460 #define SYSCTL_VNET_OPAQUE(parent, nbr, name, access, ptr, len, fmt,    \
 461             descr)                                                      \
 462         SYSCTL_OPAQUE(parent, nbr, name, access, ptr, len, fmt, descr)
 463 #define SYSCTL_VNET_STRING(parent, nbr, name, access, arg, len, descr)  \
 464         SYSCTL_STRING(parent, nbr, name, access, arg, len, descr)
 465 #define SYSCTL_VNET_STRUCT(parent, nbr, name, access, ptr, type, descr) \
 466         SYSCTL_STRUCT(parent, nbr, name, access, ptr, type, descr)
 467 #define SYSCTL_VNET_UINT(parent, nbr, name, access, ptr, val, descr)    \
 468         SYSCTL_UINT(parent, nbr, name, access, ptr, val, descr)
 469 #define VNET_SYSCTL_ARG(req, arg1)
 470 #endif /* SYSCTL_OID */
 471
 472 /*
 473  * When VIMAGE isn't compiled into the kernel, VNET_SYSINIT/VNET_SYSUNINIT
 474  * map into normal sysinits, which have the same ordering properties.
 475  */
 476 #define VNET_SYSINIT(ident, subsystem, order, func, arg)                \
 477         SYSINIT(ident, subsystem, order, func, arg)
 478 #define VNET_SYSUNINIT(ident, subsystem, order, func, arg)              \
 479         SYSUNINIT(ident, subsystem, order, func, arg)
 480
 481 /*
 482  * Without VIMAGE revert to the default implementation.
 483  */
 484 #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
 485         (tag) = eventhandler_register(NULL, #name, func, arg, priority)
 486 #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)    \
 487         eventhandler_register(NULL, #name, func, arg, priority)
 488 #endif /* VIMAGE */
 489 #endif /* _KERNEL */
 490
 491 #endif /* !_NET_VNET_H_ */