1/*
2 * Copyright (c) 2016-2018 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*-
29 * Copyright (c) 1999 Michael Smith <msmith@freebsd.org>
30 * All rights reserved.
31 *
32 * Redistribution and use in source and binary forms, with or without
33 * modification, are permitted provided that the following conditions
34 * are met:
35 * 1. Redistributions of source code must retain the above copyright
36 * notice, this list of conditions and the following disclaimer.
37 * 2. Redistributions in binary form must reproduce the above copyright
38 * notice, this list of conditions and the following disclaimer in the
39 * documentation and/or other materials provided with the distribution.
40 *
41 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * $FreeBSD$
54 */
55
56#ifndef _SYS_EVENTHANDLER_H_
57#define _SYS_EVENTHANDLER_H_
58
59#include <ptrauth.h>
60
61#include <kern/locks.h>
62#include <sys/queue.h>
63#include <sys/cdefs.h>
64#include <sys/syslog.h>
65#include <uuid/uuid.h>
66
67extern int evh_debug;
68extern lck_grp_t el_lock_grp;
69extern lck_attr_t el_lock_attr;
70extern struct eventhandler_entry_arg eventhandler_entry_dummy_arg;
71
72struct eventhandler_lists_ctxt {
73 TAILQ_HEAD(, eventhandler_list) eventhandler_lists;
74 int eventhandler_lists_initted;
75 decl_lck_mtx_data(, eventhandler_mutex);
76};
77
78struct eventhandler_entry_arg {
79 uuid_t ee_fm_uuid; /* Flow manager UUID */
80 uuid_t ee_fr_uuid; /* Flow route UUID */
81};
82
83struct eventhandler_entry {
84 TAILQ_ENTRY(eventhandler_entry) ee_link;
85 int ee_priority;
86#define EHE_DEAD_PRIORITY (-1)
87 struct eventhandler_entry_arg ee_arg;
88};
89
90#define EVENTHANDLER_MAX_NAME 32
91
92struct eventhandler_list {
93 char el_name[EVENTHANDLER_MAX_NAME];
94 int el_flags;
95#define EHL_INITTED (1<<0)
96 u_int el_runcount;
97 decl_lck_mtx_data(, el_lock);
98 TAILQ_ENTRY(eventhandler_list) el_link;
99 TAILQ_HEAD(, eventhandler_entry) el_entries;
100};
101
102typedef struct eventhandler_entry *eventhandler_tag;
103
104#define EHL_LOCK_INIT(p) lck_mtx_init(&(p)->el_lock, &el_lock_grp, &el_lock_attr)
105#define EHL_LOCK(p) lck_mtx_lock(&(p)->el_lock)
106#define EHL_LOCK_SPIN(p) lck_mtx_lock_spin(&(p)->el_lock)
107#define EHL_LOCK_CONVERT(p) lck_mtx_convert_spin(&(p)->el_lock)
108#define EHL_UNLOCK(p) lck_mtx_unlock(&(p)->el_lock)
109#define EHL_LOCK_ASSERT(p, x) LCK_MTX_ASSERT(&(p)->el_lock, x)
110#define EHL_LOCK_DESTROY(p) lck_mtx_destroy(&(p)->el_lock, &el_lock_grp)
111
112#define evhlog(x) do { if (evh_debug >= 1) log x; } while (0)
113
114/*
115 * Macro to invoke the handlers for a given event.
116 */
117#define _EVENTHANDLER_INVOKE(name, list, ...) do { \
118 struct eventhandler_entry * _ep __single; \
119 struct eventhandler_entry_ ## name * _t __single; \
120 \
121 VERIFY((list)->el_flags & EHL_INITTED); \
122 EHL_LOCK_ASSERT((list), LCK_MTX_ASSERT_OWNED); \
123 (list)->el_runcount++; \
124 VERIFY((list)->el_runcount > 0); \
125 evhlog((LOG_DEBUG, "eventhandler_invoke(\"" __STRING(name) "\")")); \
126 TAILQ_FOREACH(_ep, &((list)->el_entries), ee_link) { \
127 if (_ep->ee_priority != EHE_DEAD_PRIORITY) { \
128 EHL_UNLOCK((list)); \
129 _t = (struct eventhandler_entry_ ## name *)_ep; \
130 evhlog((LOG_DEBUG, "eventhandler_invoke: executing %p", \
131 (void *)VM_KERNEL_UNSLIDE((uint64_t)(_t->eh_func)))); \
132 _t->eh_func(_ep->ee_arg , ## __VA_ARGS__); \
133 EHL_LOCK_SPIN((list)); \
134 } \
135 } \
136 VERIFY((list)->el_runcount > 0); \
137 (list)->el_runcount--; \
138 if ((list)->el_runcount == 0) { \
139 EHL_LOCK_CONVERT((list)); \
140 eventhandler_prune_list(list); \
141 } \
142 EHL_UNLOCK((list)); \
143} while (0)
144
145/*
146 * Slow handlers are entirely dynamic; lists are created
147 * when entries are added to them, and thus have no concept of "owner",
148 *
149 * Slow handlers need to be declared, but do not need to be defined. The
150 * declaration must be in scope wherever the handler is to be invoked.
151 */
152#define EVENTHANDLER_DECLARE(name, type) \
153struct eventhandler_entry_ ## name \
154{ \
155 struct eventhandler_entry ee; \
156 type eh_func; \
157}; \
158struct __hack
159
160/*
161 * XXX EVENTHANDLER_DEFINE by itself doesn't do much on XNU
162 * All it does is that it declares the static eventhandler_tag
163 * and defines an init routine that still needs to called to put the
164 * event and callback on the list.
165 */
166#define EVENTHANDLER_DEFINE(evthdlr_ref, name, func, arg, priority) \
167 static eventhandler_tag name ## _tag; \
168 static void name ## _evh_init(void *ctx) \
169 { \
170 name ## _tag = EVENTHANDLER_REGISTER(evthdlr_ref, name, func, ctx, \
171 priority); \
172 } \
173 SYSINIT(name ## _evh_init, SI_SUB_CONFIGURE, SI_ORDER_ANY, \
174 name ## _evh_init, arg); \
175 struct __hack
176
177#define EVENTHANDLER_INVOKE(evthdlr_ref, name, ...) \
178do { \
179 struct eventhandler_list *__single _el; \
180 \
181 if ((_el = eventhandler_find_list(evthdlr_ref, #name)) != NULL) \
182 _EVENTHANDLER_INVOKE(name, _el , ## __VA_ARGS__); \
183} while (0)
184
185#define EVENTHANDLER_REGISTER(evthdlr_ref, name, func, arg, priority) \
186 eventhandler_register(evthdlr_ref, NULL, #name, ptrauth_nop_cast(void * __single, &func), arg, priority)
187
188#define EVENTHANDLER_DEREGISTER(evthdlr_ref, name, tag) \
189do { \
190 struct eventhandler_list *__single _el; \
191 \
192 if ((_el = eventhandler_find_list(evthdlr_ref, #name)) != NULL) \
193 eventhandler_deregister(_el, tag); \
194} while(0)
195
196void eventhandler_init(void);
197eventhandler_tag eventhandler_register(struct eventhandler_lists_ctxt *evthdlr_lists_ctxt,
198 struct eventhandler_list *list, const char *name, void *func, struct eventhandler_entry_arg arg, int priority);
199void eventhandler_deregister(struct eventhandler_list *list,
200 eventhandler_tag tag);
201struct eventhandler_list *eventhandler_find_list(
202 struct eventhandler_lists_ctxt *evthdlr_lists_ctxt, const char *name);
203void eventhandler_prune_list(struct eventhandler_list *list);
204void eventhandler_lists_ctxt_init(struct eventhandler_lists_ctxt *evthdlr_lists_ctxt);
205void eventhandler_lists_ctxt_destroy(struct eventhandler_lists_ctxt *evthdlr_lists_ctxt);
206
207/* Generic priority levels */
208#define EVENTHANDLER_PRI_FIRST 0
209#define EVENTHANDLER_PRI_ANY 10000
210#define EVENTHANDLER_PRI_LAST 20000
211
212#endif /* _SYS_EVENTHANDLER_H_ */
213