src/vlib/init.h

/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * init.h: mechanism for functions to be called at init/exit.
 *
 * Copyright (c) 2008 Eliot Dresselhaus
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef included_vlib_init_h
#define included_vlib_init_h

#include <vppinfra/error.h>
#include <vppinfra/format.h>
#include <vppinfra/hash.h>

/* Init/exit functions: called at start/end of main routine.  Init
   functions are typically used to register and setup packet
   processing nodes.  */

typedef clib_error_t *(vlib_init_function_t) (struct vlib_main_t * vm);

typedef struct _vlib_init_function_list_elt
{
  struct _vlib_init_function_list_elt *next_init_function;
  vlib_init_function_t *f;
} _vlib_init_function_list_elt_t;

/* Configuration functions: called with configuration input just before
   main polling loop starts. */
typedef clib_error_t *(vlib_config_function_t) (struct vlib_main_t * vm,
						unformat_input_t * input);

typedef struct vlib_config_function_runtime_t
{
  /* Function to call.  Set to null once function has already been called. */
  vlib_config_function_t *function;

  /* Input for function. */
  unformat_input_t input;

  /* next config function registration */
  struct vlib_config_function_runtime_t *next_registration;

  /* To be invoked as soon as the clib heap is available */
  u8 is_early;

  /* Name used to distinguish input on command line. */
  char name[32];
} vlib_config_function_runtime_t;

#define VLIB_REMOVE_FROM_LINKED_LIST(first,p,next)              \
{                                                               \
  if (first == p)                                               \
      first = (p)->next;                                        \
  else                                                          \
    {                                                           \
      __typeof__ (p) current = first;                           \
	while (current->next)                                   \
	  {                                                     \
	    if (current->next == p)                             \
	      {                                                 \
		current->next = current->next->next;            \
		break;                                          \
	      }                                                 \
	    current = current->next;                            \
	  }                                                     \
    }                                                           \
}

#define _VLIB_INIT_FUNCTION_SYMBOL(x, type)	\
  _vlib_##type##_function_##x

#define VLIB_INIT_FUNCTION_SYMBOL(x)		\
  _VLIB_INIT_FUNCTION_SYMBOL(x, init)
#define VLIB_MAIN_LOOP_ENTER_FUNCTION_SYMBOL(x)		\
  _VLIB_INIT_FUNCTION_SYMBOL(x, main_loop_enter)
#define VLIB_MAIN_LOOP_EXIT_FUNCTION_SYMBOL(x)	\
  _VLIB_INIT_FUNCTION_SYMBOL(x, main_loop_exit)
#define VLIB_CONFIG_FUNCTION_SYMBOL(x)		\
  _VLIB_INIT_FUNCTION_SYMBOL(x, config)

/* Declaration is global (e.g. not static) so that init functions can
   be called from other modules to resolve init function depend. */

#define VLIB_DECLARE_INIT_FUNCTION(x, tag)                      \
vlib_init_function_t * _VLIB_INIT_FUNCTION_SYMBOL (x, tag) = x; \
static void __vlib_add_##tag##_function_##x (void)              \
    __attribute__((__constructor__)) ;                          \
static void __vlib_add_##tag##_function_##x (void)              \
{                                                               \
 vlib_main_t * vm = vlib_get_main();                            \
 static _vlib_init_function_list_elt_t _vlib_init_function;     \
 _vlib_init_function.next_init_function                         \
    = vm->tag##_function_registrations;                         \
  vm->tag##_function_registrations = &_vlib_init_function;      \
 _vlib_init_function.f = &x;                                    \
}                                                               \
static void __vlib_rm_##tag##_function_##x (void)               \
    __attribute__((__destructor__)) ;                           \
static void __vlib_rm_##tag##_function_##x (void)               \
{                                                               \
  vlib_main_t * vm = vlib_get_main();                           \
  _vlib_init_function_list_elt_t *next;                         \
  if (vm->tag##_function_registrations->f == &x)                \
    {                                                           \
      vm->tag##_function_registrations =                        \
        vm->tag##_function_registrations->next_init_function;   \
      return;                                                   \
    }                                                           \
  next = vm->tag##_function_registrations;                      \
  while (next->next_init_function)                              \
    {                                                           \
      if (next->next_init_function->f == &x)                    \
        {                                                       \
          next->next_init_function =                            \
            next->next_init_function->next_init_function;       \
          return;                                               \
        }                                                       \
      next = next->next_init_function;                          \
    }                                                           \
}

#define VLIB_INIT_FUNCTION(x) VLIB_DECLARE_INIT_FUNCTION(x,init)
#define VLIB_WORKER_INIT_FUNCTION(x) VLIB_DECLARE_INIT_FUNCTION(x,worker_init)

#define VLIB_MAIN_LOOP_ENTER_FUNCTION(x) \
  VLIB_DECLARE_INIT_FUNCTION(x,main_loop_enter)
#define VLIB_MAIN_LOOP_EXIT_FUNCTION(x) \
VLIB_DECLARE_INIT_FUNCTION(x,main_loop_exit)

#define VLIB_CONFIG_FUNCTION(x,n,...)                           \
    __VA_ARGS__ vlib_config_function_runtime_t                  \
    VLIB_CONFIG_FUNCTION_SYMBOL(x);                             \
static void __vlib_add_config_function_##x (void)               \
    __attribute__((__constructor__)) ;                          \
static void __vlib_add_config_function_##x (void)               \
{                                                               \
    vlib_main_t * vm = vlib_get_main();                         \
    VLIB_CONFIG_FUNCTION_SYMBOL(x).next_registration            \
       = vm->config_function_registrations;                     \
    vm->config_function_registrations                           \
       = &VLIB_CONFIG_FUNCTION_SYMBOL(x);                       \
}                                                               \
static void __vlib_rm_config_function_##x (void)                \
    __attribute__((__destructor__)) ;                           \
static void __vlib_rm_config_function_##x (void)                \
{                                                               \
    vlib_main_t * vm = vlib_get_main();                         \
    vlib_config_function_runtime_t *p =                         \
       & VLIB_CONFIG_FUNCTION_SYMBOL (x);                       \
    VLIB_REMOVE_FROM_LINKED_LIST                                \
      (vm->config_function_registrations, p, next_registration);\
}                                                               \
  vlib_config_function_runtime_t                                \
    VLIB_CONFIG_FUNCTION_SYMBOL (x)                             \
  = {                                                           \
    .name = n,                                                  \
    .function = x,                                              \
    .is_early = 0,						\
  }

#define VLIB_EARLY_CONFIG_FUNCTION(x,n,...)                     \
    __VA_ARGS__ vlib_config_function_runtime_t                  \
    VLIB_CONFIG_FUNCTION_SYMBOL(x);                             \
static void __vlib_add_config_function_##x (void)               \
    __attribute__((__constructor__)) ;                          \
static void __vlib_add_config_function_##x (void)               \
{                                                               \
    vlib_main_t * vm = vlib_get_main();                         \
    VLIB_CONFIG_FUNCTION_SYMBOL(x).next_registration            \
       = vm->config_function_registrations;                     \
    vm->config_function_registrations                           \
       = &VLIB_CONFIG_FUNCTION_SYMBOL(x);                       \
}                                                               \
static void __vlib_rm_config_function_##x (void)                \
    __attribute__((__destructor__)) ;                           \
static void __vlib_rm_config_function_##x (void)                \
{                                                               \
    vlib_main_t * vm = vlib_get_main();                         \
    vlib_config_function_runtime_t *p =                         \
       & VLIB_CONFIG_FUNCTION_SYMBOL (x);                       \
    VLIB_REMOVE_FROM_LINKED_LIST                                \
      (vm->config_function_registrations, p, next_registration);\
}                                                               \
  vlib_config_function_runtime_t                                \
    VLIB_CONFIG_FUNCTION_SYMBOL (x)                             \
  = {                                                           \
    .name = n,                                                  \
    .function = x,                                              \
    .is_early = 1,						\
  }

/* Call given init function: used for init function dependencies. */
#define vlib_call_init_function(vm, x)					\
  ({									\
    extern vlib_init_function_t * VLIB_INIT_FUNCTION_SYMBOL (x);	\
    vlib_init_function_t * _f = VLIB_INIT_FUNCTION_SYMBOL (x);		\
    clib_error_t * _error = 0;						\
    if (! hash_get (vm->init_functions_called, _f))			\
      {									\
	hash_set1 (vm->init_functions_called, _f);			\
	_error = _f (vm);						\
      }									\
    _error;								\
  })

/* Don't call given init function: used to suppress parts of the netstack */
#define vlib_mark_init_function_complete(vm, x)				\
  ({									\
    extern vlib_init_function_t * VLIB_INIT_FUNCTION_SYMBOL (x);	\
    vlib_init_function_t * _f = VLIB_INIT_FUNCTION_SYMBOL (x);		\
    hash_set1 (vm->init_functions_called, _f);				\
  })

#define vlib_call_post_graph_init_function(vm, x)			\
  ({									\
    extern vlib_init_function_t * VLIB_POST_GRAPH_INIT_FUNCTION_SYMBOL (x); \
    vlib_init_function_t * _f = VLIB_POST_GRAPH_INIT_FUNCTION_SYMBOL (x); \
    clib_error_t * _error = 0;						\
    if (! hash_get (vm->init_functions_called, _f))			\
      {									\
	hash_set1 (vm->init_functions_called, _f);			\
	_error = _f (vm);						\
      }									\
    _error;								\
  })

#define vlib_call_config_function(vm, x)			\
  ({								\
    vlib_config_function_runtime_t * _r;			\
    clib_error_t * _error = 0;					\
    extern vlib_config_function_runtime_t			\
      VLIB_CONFIG_FUNCTION_SYMBOL (x);				\
								\
    _r = &VLIB_CONFIG_FUNCTION_SYMBOL (x);			\
    if (! hash_get (vm->init_functions_called, _r->function))	\
      {								\
        hash_set1 (vm->init_functions_called, _r->function);	\
	_error = _r->function (vm, &_r->input);			\
      }								\
    _error;							\
  })

/* External functions. */
clib_error_t *vlib_call_all_init_functions (struct vlib_main_t *vm);
clib_error_t *vlib_call_all_config_functions (struct vlib_main_t *vm,
					      unformat_input_t * input,
					      int is_early);
clib_error_t *vlib_call_all_main_loop_enter_functions (struct vlib_main_t
						       *vm);
clib_error_t *vlib_call_all_main_loop_exit_functions (struct vlib_main_t *vm);
clib_error_t *vlib_call_init_exit_functions (struct vlib_main_t *vm,
					     _vlib_init_function_list_elt_t *
					     head, int call_once);

#define foreach_vlib_module_reference		\
  _ (node_cli)					\
  _ (trace_cli)

/* Dummy function to get node_cli.c linked in. */
#define _(x) void vlib_##x##_reference (void);
foreach_vlib_module_reference
#undef _
#endif /* included_vlib_init_h */
/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */