include/sys/hook.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 /*
  27  * This file includes definitions of kernel hook framework components
  28  */
  29
  30 #ifndef _SYS_HOOK_H
  31 #define _SYS_HOOK_H
  32
  33 #include <sys/queue.h>
  34 #include <sys/netstack.h>
  35
  36 #ifdef  __cplusplus
  37 extern "C" {
  38 #endif
  39
  40 /*
  41  * Definition exposed to hook provider and consumer
  42  */
  43
  44 #define HOOK_VERSION    1
  45
  46 typedef uintptr_t hook_data_t;
  47
  48 struct hook_event_int;
  49 typedef struct hook_event_int *hook_event_token_t;
  50 struct hook_int;
  51 typedef struct hook_int *hook_token_t;
  52
  53 typedef int (* hook_func_t)(hook_event_token_t, hook_data_t, void *);
  54
  55 /*
  56  * A hook_notify_cmd_t is given as an argument to functions called as part of
  57  * the notify callbacks that have been registered firing.
  58  */
  59 typedef enum hook_notify_cmd_e {
  60         HN_NONE = 0,
  61         HN_REGISTER = 1,
  62         HN_UNREGISTER = 2
  63 } hook_notify_cmd_t;
  64
  65 /*
  66  *
  67  */
  68 typedef enum hook_hint_e {
  69         HH_NONE = 0,
  70         HH_FIRST,
  71         HH_LAST,
  72         HH_BEFORE,
  73         HH_AFTER
  74 } hook_hint_t;
  75
  76 /*
  77  * Hook
  78  */
  79 typedef struct hook_s {
  80         int             h_version;
  81         hook_func_t     h_func;         /* callback func */
  82         char            *h_name;        /* name of this hook */
  83         uint_t          h_flags;        /* extra hook properties */
  84         hook_hint_t     h_hint;         /* What type of hint is hintvalue */
  85         uintptr_t       h_hintvalue;
  86         void            *h_arg;         /* value to pass back into the hook */
  87 } hook_t;
  88
  89 #define HOOK_INIT(x, fn, r, a)          \
  90         do {                                    \
  91                 (x) = hook_alloc(HOOK_VERSION); \
  92                 (x)->h_func = (fn);             \
  93                 (x)->h_name = (r);              \
  94                 (x)->h_flags = 0;               \
  95                 (x)->h_hint = HH_NONE;          \
  96                 (x)->h_hintvalue = 0;           \
  97                 (x)->h_arg = (a);               \
  98                 _NOTE(CONSTCOND)                \
  99         } while (0)
 100
 101 /*
 102  * Family
 103  */
 104 typedef struct hook_family_s {
 105         int             hf_version;     /* version number */
 106         char            *hf_name;       /* family name */
 107 } hook_family_t;
 108
 109 #define HOOK_FAMILY_INIT(x, y)                  \
 110         do {                                    \
 111                 (x)->hf_version = HOOK_VERSION; \
 112                 (x)->hf_name = (y);             \
 113                 _NOTE(CONSTCOND)                \
 114         } while (0)
 115
 116 /*
 117  * Event
 118  */
 119 typedef struct hook_event_s {
 120         int             he_version;
 121         char            *he_name;       /* name of this hook list */
 122         int             he_flags;       /* 1 = multiple entries allowed */
 123         boolean_t       he_interested;  /* true if callback exist */
 124 } hook_event_t;
 125
 126 #define HOOK_RDONLY     0x1             /* Callbacks must not change data */
 127                                         /* Multiple callbacks are allowed */
 128
 129 #define HOOK_EVENT_INIT(x, y)                   \
 130         do {                                    \
 131                 (x)->he_version = HOOK_VERSION; \
 132                 (x)->he_name = (y);             \
 133                 (x)->he_flags = 0;              \
 134                 (x)->he_interested = B_FALSE;   \
 135                 _NOTE(CONSTCOND)                \
 136         } while (0)
 137
 138 typedef int (* hook_notify_fn_t)(hook_notify_cmd_t, void *, const char *,
 139     const char *, const char *);
 140
 141 extern  hook_t          *hook_alloc(const int version);
 142 extern  void            hook_free(hook_t *);
 143
 144 #ifdef  __cplusplus
 145 }
 146 #endif
 147
 148 #endif /* _SYS_HOOK_H */