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 | |
67 | extern int evh_debug; |
68 | extern lck_grp_t el_lock_grp; |
69 | extern lck_attr_t el_lock_attr; |
70 | extern struct eventhandler_entry_arg eventhandler_entry_dummy_arg; |
71 | |
72 | struct eventhandler_lists_ctxt { |
73 | TAILQ_HEAD(, eventhandler_list) eventhandler_lists; |
74 | int eventhandler_lists_initted; |
75 | decl_lck_mtx_data(, eventhandler_mutex); |
76 | }; |
77 | |
78 | struct eventhandler_entry_arg { |
79 | uuid_t ee_fm_uuid; /* Flow manager UUID */ |
80 | uuid_t ee_fr_uuid; /* Flow route UUID */ |
81 | }; |
82 | |
83 | struct 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 | |
92 | struct 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 | |
102 | typedef 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) \ |
153 | struct eventhandler_entry_ ## name \ |
154 | { \ |
155 | struct eventhandler_entry ee; \ |
156 | type eh_func; \ |
157 | }; \ |
158 | struct __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, ...) \ |
178 | do { \ |
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) \ |
189 | do { \ |
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 | |
196 | void eventhandler_init(void); |
197 | eventhandler_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); |
199 | void eventhandler_deregister(struct eventhandler_list *list, |
200 | eventhandler_tag tag); |
201 | struct eventhandler_list *eventhandler_find_list( |
202 | struct eventhandler_lists_ctxt *evthdlr_lists_ctxt, const char *name); |
203 | void eventhandler_prune_list(struct eventhandler_list *list); |
204 | void eventhandler_lists_ctxt_init(struct eventhandler_lists_ctxt *evthdlr_lists_ctxt); |
205 | void 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 | |