1 /* $NetBSD: config_hook.c,v 1.12 2020/11/21 21:08:32 thorpej Exp $ */ 2 3 /*- 4 * Copyright (c) 1999-2001 5 * Shin Takemura and PocketBSD Project. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the PocketBSD project 18 * and its contributors. 19 * 4. Neither the name of the project nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 */ 36 37 #include <sys/cdefs.h> 38 __KERNEL_RCSID(0, "$NetBSD: config_hook.c,v 1.12 2020/11/21 21:08:32 thorpej Exp $"); 39 40 #include <sys/param.h> 41 #include <sys/device.h> 42 #include <sys/kmem.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 46 #include <machine/config_hook.h> 47 48 struct hook_rec { 49 TAILQ_ENTRY(hook_rec) hr_link; 50 void *hr_ctx; 51 int hr_type; 52 long hr_id; 53 enum config_hook_mode hr_mode; 54 int (*hr_func)(void *, int, long, void *); 55 }; 56 57 TAILQ_HEAD(hook_list, hook_rec); 58 struct hook_list hook_lists[CONFIG_HOOK_NTYPES]; 59 struct hook_list call_list; 60 61 void 62 config_hook_init(void) 63 { 64 int i; 65 66 for (i = 0; i < CONFIG_HOOK_NTYPES; i++) { 67 TAILQ_INIT(&hook_lists[i]); 68 } 69 TAILQ_INIT(&call_list); 70 } 71 72 config_hook_tag 73 config_hook(int type, long id, enum config_hook_mode mode, 74 int (*func)(void *, int, long, void *), void *ctx) 75 { 76 struct hook_rec *hr, *cr, *prev_hr; 77 int s; 78 79 /* check type value */ 80 if (type < 0 || CONFIG_HOOK_NTYPES <= type) { 81 panic("config_hook: invalid hook type"); 82 } 83 84 /* check mode compatibility */ 85 prev_hr = NULL; 86 TAILQ_FOREACH(hr, &hook_lists[type], hr_link) { 87 if (hr->hr_id == id) { 88 if (hr->hr_mode != mode) { 89 panic("config_hook: incompatible mode on " 90 "type=%d/id=%ld != %d", 91 type, id, hr->hr_mode); 92 } 93 prev_hr = hr; 94 } 95 } 96 switch (mode) { 97 case CONFIG_HOOK_SHARE: 98 /* nothing to do */ 99 break; 100 case CONFIG_HOOK_REPLACE: 101 if (prev_hr != NULL) { 102 printf("config_hook: type=%d/id=%ld is replaced", 103 type, id); 104 s = splhigh(); 105 TAILQ_REMOVE(&hook_lists[type], prev_hr, hr_link); 106 TAILQ_NEXT(prev_hr, hr_link) = NULL; 107 splx(s); 108 } 109 break; 110 case CONFIG_HOOK_EXCLUSIVE: 111 if (prev_hr != NULL) { 112 panic("config_hook: type=%d/id=%ld is already " 113 "hooked(%p)", type, id, prev_hr); 114 } 115 break; 116 default: 117 break; 118 } 119 120 /* allocate new record */ 121 hr = kmem_alloc(sizeof(*hr), KM_SLEEP); 122 hr->hr_ctx = ctx; 123 hr->hr_type = type; 124 hr->hr_id = id; 125 hr->hr_func = func; 126 hr->hr_mode = mode; 127 128 s = splhigh(); 129 TAILQ_INSERT_HEAD(&hook_lists[type], hr, hr_link); 130 131 /* update call list */ 132 TAILQ_FOREACH(cr, &call_list, hr_link) { 133 if (cr->hr_type == type && cr->hr_id == id) { 134 if (cr->hr_func != NULL && 135 cr->hr_mode != mode) { 136 panic("config_hook: incompatible mode on " 137 "type=%d/id=%ld != %d", 138 type, id, cr->hr_mode); 139 } 140 cr->hr_ctx = ctx; 141 cr->hr_func = func; 142 cr->hr_mode = mode; 143 } 144 } 145 splx(s); 146 147 return (hr); 148 } 149 150 void 151 config_unhook(config_hook_tag hrx) 152 { 153 int s; 154 struct hook_rec *hr = (struct hook_rec*)hrx, *cr; 155 156 if (TAILQ_NEXT(hr, hr_link) != NULL) { 157 s = splhigh(); 158 TAILQ_REMOVE(&hook_lists[hr->hr_type], hr, hr_link); 159 TAILQ_NEXT(hr, hr_link) = NULL; 160 /* update call list */ 161 TAILQ_FOREACH(cr, &call_list, hr_link) { 162 if (cr->hr_type == hr->hr_type && 163 cr->hr_id == hr->hr_id) 164 cr->hr_func = NULL; 165 } 166 splx(s); 167 } 168 kmem_free(hr, sizeof(*hr)); 169 } 170 171 int 172 __config_hook_call(int type, long id, void *msg, int reverse) 173 { 174 int res; 175 struct hook_rec *hr; 176 177 /* Check type value. */ 178 if (type < 0 || CONFIG_HOOK_NTYPES <= type) { 179 panic("config_hook: invalid hook type"); 180 } 181 182 res = -1; 183 if (reverse) { 184 TAILQ_FOREACH_REVERSE(hr, &hook_lists[type], hook_list, 185 hr_link) { 186 if (hr->hr_id == id) 187 res = (*hr->hr_func)(hr->hr_ctx, type, id,msg); 188 } 189 } else { 190 TAILQ_FOREACH(hr, &hook_lists[type], hr_link) { 191 if (hr->hr_id == id) 192 res = (*hr->hr_func)(hr->hr_ctx, type, id,msg); 193 } 194 } 195 196 return (res); 197 } 198 199 config_hook_tag 200 config_connect(int type, long id) 201 { 202 int s; 203 struct hook_rec *cr, *hr; 204 205 /* check type value */ 206 if (type < 0 || CONFIG_HOOK_NTYPES <= type) { 207 panic("config_hook: invalid hook type"); 208 } 209 210 /* allocate new record */ 211 cr = kmem_alloc(sizeof(*hr), KM_SLEEP); 212 cr->hr_func = NULL; 213 cr->hr_type = type; 214 cr->hr_id = id; 215 216 s = splhigh(); 217 /* insert the record into the call list */ 218 TAILQ_INSERT_HEAD(&call_list, cr, hr_link); 219 220 /* scan hook list */ 221 TAILQ_FOREACH(hr, &hook_lists[type], hr_link) { 222 if (hr->hr_id == id) { 223 if (hr->hr_mode == CONFIG_HOOK_SHARE) 224 panic("config_connect: can't connect with " 225 "shared hook, type=%d id=%ld", type, id); 226 cr->hr_ctx = hr->hr_ctx; 227 cr->hr_func = hr->hr_func; 228 cr->hr_mode = hr->hr_mode; 229 } 230 } 231 splx(s); 232 233 return (cr); 234 } 235 236 void 237 config_disconnect(config_call_tag crx) 238 { 239 int s; 240 struct hook_rec *cr = (struct hook_rec*)crx; 241 242 s = splhigh(); 243 TAILQ_REMOVE(&call_list, cr, hr_link); 244 splx(s); 245 246 kmem_free(cr, sizeof(*cr)); 247 } 248 249 int 250 config_connected_call(config_call_tag crx, void *msg) 251 { 252 int res; 253 struct hook_rec *cr = (struct hook_rec*)crx; 254 255 if (cr->hr_func != NULL) 256 res = (*cr->hr_func)(cr->hr_ctx, cr->hr_type, cr->hr_id, msg); 257 else 258 res = -1; 259 260 return (res); 261 } 262
Indexes created Sat Sep 20 22:09:52 GMT 2025