xref: /netbsd-src/sys/dev/bio.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: bio.c,v 1.4 2007/12/05 07:06:50 ad Exp $ */
2 /*	$OpenBSD: bio.c,v 1.9 2007/03/20 02:35:55 marco Exp $	*/
3 
4 /*
5  * Copyright (c) 2002 Niklas Hallqvist.  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  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 /* A device controller ioctl tunnelling device.  */
29 
30 #include <sys/cdefs.h>
31 __KERNEL_RCSID(0, "$NetBSD: bio.c,v 1.4 2007/12/05 07:06:50 ad Exp $");
32 
33 #include <sys/param.h>
34 #include <sys/conf.h>
35 #include <sys/device.h>
36 #include <sys/event.h>
37 #include <sys/ioctl.h>
38 #include <sys/malloc.h>
39 #include <sys/queue.h>
40 #include <sys/systm.h>
41 #include <sys/mutex.h>
42 #include <sys/proc.h>
43 #include <sys/kauth.h>
44 
45 #include <dev/biovar.h>
46 
47 struct bio_mapping {
48 	LIST_ENTRY(bio_mapping) bm_link;
49 	struct device *bm_dev;
50 	int (*bm_ioctl)(struct device *, u_long, void *);
51 };
52 
53 LIST_HEAD(, bio_mapping) bios = LIST_HEAD_INITIALIZER(bios);
54 static kmutex_t bio_lock;
55 static bool bio_lock_initialized = false;
56 
57 static void bio_initialize(void);
58 void	bioattach(int);
59 int	bioclose(dev_t, int, int, struct lwp *);
60 int	bioioctl(dev_t, u_long, void *, int, struct lwp *);
61 int	bioopen(dev_t, int, int, struct lwp *);
62 
63 int	bio_delegate_ioctl(struct bio_mapping *, u_long, void *);
64 struct	bio_mapping *bio_lookup(char *);
65 int	bio_validate(void *);
66 
67 const struct cdevsw bio_cdevsw = {
68         bioopen, bioclose, noread, nowrite, bioioctl,
69         nostop, notty, nopoll, nommap, nokqfilter, 0
70 };
71 
72 
73 void
74 bio_initialize(void)
75 {
76 	if (bio_lock_initialized)
77 		return;
78 
79 	mutex_init(&bio_lock, MUTEX_DEFAULT, IPL_VM);
80 	bio_lock_initialized = true;
81 }
82 
83 void
84 bioattach(int nunits)
85 {
86 	if (!bio_lock_initialized)
87 		bio_initialize();
88 }
89 
90 int
91 bioopen(dev_t dev, int flags, int mode, struct lwp *l)
92 {
93 	return 0;
94 }
95 
96 int
97 bioclose(dev_t dev, int flags, int mode, struct lwp *l)
98 {
99 	return 0;
100 }
101 
102 int
103 bioioctl(dev_t dev, u_long cmd, void *addr, int flag, struct  lwp *l)
104 {
105 	struct bio_locate *locate;
106 	struct bio_common *common;
107 	char name[16];
108 	int error;
109 
110 	switch(cmd) {
111 	case BIOCLOCATE:
112 	case BIOCINQ:
113 	case BIOCDISK:
114 	case BIOCVOL:
115 		error = kauth_authorize_device_passthru(l->l_cred, dev,
116 		    KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_READCONF, addr);
117 		if (error)
118 			return error;
119 		break;
120 	case BIOCBLINK:
121 	case BIOCSETSTATE:
122 		error = kauth_authorize_device_passthru(l->l_cred, dev,
123 		    KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_WRITECONF, addr);
124 		if (error)
125 			return error;
126 		break;
127 	case BIOCALARM: {
128 		struct bioc_alarm *alarm = (struct bioc_alarm *)addr;
129 		switch (alarm->ba_opcode) {
130 		case BIOC_SADISABLE:
131 		case BIOC_SAENABLE:
132 		case BIOC_SASILENCE:
133 		case BIOC_SATEST:
134 			error = kauth_authorize_device_passthru(l->l_cred, dev,
135 			    KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_WRITECONF, addr);
136 			if (error)
137 				return error;
138 			break;
139 		case BIOC_GASTATUS:
140 			error = kauth_authorize_device_passthru(l->l_cred, dev,
141 			    KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_READCONF, addr);
142 			if (error)
143 				return error;
144 			break;
145 		default:
146 			return EINVAL;
147 		}
148 		break;
149 	}
150 	default:
151 		return ENOTTY;
152 	}
153 
154 	switch (cmd) {
155 	case BIOCLOCATE:
156 		locate = (struct bio_locate *)addr;
157 		error = copyinstr(locate->bl_name, name, 16, NULL);
158 		if (error != 0)
159 			return error;
160 		locate->bl_cookie = bio_lookup(name);
161 		if (locate->bl_cookie == NULL)
162 			return ENOENT;
163 		break;
164 
165 	default:
166 		common = (struct bio_common *)addr;
167 		mutex_enter(&bio_lock);
168 		if (!bio_validate(common->bc_cookie)) {
169 			mutex_exit(&bio_lock);
170 			return ENOENT;
171 		}
172 		mutex_exit(&bio_lock);
173 		error = bio_delegate_ioctl(
174 		    (struct bio_mapping *)common->bc_cookie, cmd, addr);
175 		return error;
176 	}
177 	return 0;
178 }
179 
180 int
181 bio_register(struct device *dev, int (*ioctl)(struct device *, u_long, void *))
182 {
183 	struct bio_mapping *bm;
184 
185 	if (!bio_lock_initialized)
186 		bio_initialize();
187 
188 	bm = (struct bio_mapping *)malloc(sizeof(*bm), M_DEVBUF,
189 	    M_NOWAIT|M_ZERO);
190 	if (bm == NULL)
191 		return ENOMEM;
192 	bm->bm_dev = dev;
193 	bm->bm_ioctl = ioctl;
194 	mutex_enter(&bio_lock);
195 	LIST_INSERT_HEAD(&bios, bm, bm_link);
196 	mutex_exit(&bio_lock);
197 	return 0;
198 }
199 
200 void
201 bio_unregister(struct device *dev)
202 {
203 	struct bio_mapping *bm, *next;
204 
205 	mutex_enter(&bio_lock);
206 	for (bm = LIST_FIRST(&bios); bm != NULL; bm = next) {
207 		next = LIST_NEXT(bm, bm_link);
208 
209 		if (dev == bm->bm_dev) {
210 			LIST_REMOVE(bm, bm_link);
211 			free(bm, M_DEVBUF);
212 		}
213 	}
214 	mutex_exit(&bio_lock);
215 }
216 
217 struct bio_mapping *
218 bio_lookup(char *name)
219 {
220 	struct bio_mapping *bm;
221 
222 	mutex_enter(&bio_lock);
223 	LIST_FOREACH(bm, &bios, bm_link) {
224 		if (strcmp(name, bm->bm_dev->dv_xname) == 0) {
225 			mutex_exit(&bio_lock);
226 			return bm;
227 		}
228 	}
229 	mutex_exit(&bio_lock);
230 	return NULL;
231 }
232 
233 int
234 bio_validate(void *cookie)
235 {
236 	struct bio_mapping *bm;
237 
238 	LIST_FOREACH(bm, &bios, bm_link)
239 		if (bm == cookie)
240 			return 1;
241 
242 	return 0;
243 }
244 
245 int
246 bio_delegate_ioctl(struct bio_mapping *bm, u_long cmd, void *addr)
247 {
248 
249 	return bm->bm_ioctl(bm->bm_dev, cmd, addr);
250 }
251