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 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
22 /* All Rights Reserved */
23
24
25 /*
26 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
27 * Use is subject to license terms.
28 */
29
30
31 /*
32 * Clone Driver.
33 */
34
35 #include <sys/types.h>
36 #include <sys/param.h>
37 #include <sys/errno.h>
38 #include <sys/signal.h>
39 #include <sys/vfs.h>
40 #include <sys/vnode.h>
41 #include <sys/pcb.h>
42 #include <sys/user.h>
43 #include <sys/stropts.h>
44 #include <sys/stream.h>
45 #include <sys/errno.h>
46 #include <sys/sysinfo.h>
47 #include <sys/systm.h>
48 #include <sys/conf.h>
49 #include <sys/debug.h>
50 #include <sys/cred.h>
51 #include <sys/mkdev.h>
52 #include <sys/open.h>
53 #include <sys/strsubr.h>
54 #include <sys/ddi.h>
55 #include <sys/sunddi.h>
56 #include <sys/modctl.h>
57 #include <sys/policy.h>
58
59 int clnopen(queue_t *rq, dev_t *devp, int flag, int sflag, cred_t *crp);
60
61 static struct module_info clnm_info = { 0, "CLONE", 0, 0, 0, 0 };
62 static struct qinit clnrinit = { NULL, NULL, clnopen, NULL, NULL, &clnm_info,
63 NULL };
64 static struct qinit clnwinit = { NULL, NULL, NULL, NULL, NULL, &clnm_info,
65 NULL };
66 struct streamtab clninfo = { &clnrinit, &clnwinit };
67
68 static int cln_info(dev_info_t *, ddi_info_cmd_t, void *, void **);
69 static int cln_attach(dev_info_t *, ddi_attach_cmd_t);
70 static dev_info_t *cln_dip; /* private copy of devinfo pointer */
71
72 #define CLONE_CONF_FLAG (D_NEW|D_MP)
73
74 DDI_DEFINE_STREAM_OPS(clone_ops, nulldev, nulldev, cln_attach, nodev, nodev, \
75 cln_info, CLONE_CONF_FLAG, &clninfo, ddi_quiesce_not_needed);
76
77 /*
78 * Module linkage information for the kernel.
79 */
80
81 static struct modldrv modldrv = {
82 &mod_driverops, /* Type of module. This one is a pseudo driver */
83 "Clone Pseudodriver 'clone'",
84 &clone_ops, /* driver ops */
85 };
86
87 static struct modlinkage modlinkage = {
88 MODREV_1,
89 (void *)&modldrv,
90 NULL
91 };
92
93
94 int
95 _init(void)
96 {
97 return (mod_install(&modlinkage));
98 }
99
100 int
101 _fini(void)
102 {
103 /*
104 * Since the clone driver's reference count is unreliable,
105 * make sure we are never unloaded.
106 */
107 return (EBUSY);
108 }
109
110 int
111 _info(struct modinfo *modinfop)
112 {
113 return (mod_info(&modlinkage, modinfop));
114 }
115
116 /* ARGSUSED */
117 static int
118 cln_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
119 {
120 cln_dip = devi;
121 return (DDI_SUCCESS);
122 }
123
124 /* ARGSUSED */
125 static int
126 cln_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
127 void **result)
128 {
129 int error;
130
131 switch (infocmd) {
132 case DDI_INFO_DEVT2DEVINFO:
133 if (cln_dip == NULL) {
134 error = DDI_FAILURE;
135 } else {
136 *result = (void *)cln_dip;
137 error = DDI_SUCCESS;
138 }
139 break;
140 case DDI_INFO_DEVT2INSTANCE:
141 *result = (void *)0;
142 error = DDI_SUCCESS;
143 break;
144 default:
145 error = DDI_FAILURE;
146 }
147 return (error);
148 }
149
150 /*
151 * Clone open. Maj is the major device number of the streams
152 * device to open. Look up the device in the cdevsw[]. Attach
153 * its qinit structures to the read and write queues and call its
154 * open with the sflag set to CLONEOPEN. Swap in a new vnode with
155 * the real device number constructed from either
156 * a) for old-style drivers:
157 * maj and the minor returned by the device open, or
158 * b) for new-style drivers:
159 * the whole dev passed back as a reference parameter
160 * from the device open.
161 */
162 int
163 clnopen(queue_t *rq, dev_t *devp, int flag, int sflag, cred_t *crp)
164 {
165 struct streamtab *str;
166 dev_t newdev;
167 int error = 0;
168 major_t maj;
169 minor_t emaj;
170 struct qinit *rinit, *winit;
171 cdevsw_impl_t *dp;
172 uint32_t qflag;
173 uint32_t sqtype;
174 perdm_t *dmp;
175 vnode_t *vp;
176
177 if (sflag)
178 return (ENXIO);
179
180 /*
181 * Get the device to open.
182 */
183 emaj = getminor(*devp); /* minor is major for a cloned driver */
184 maj = etoimajor(emaj); /* get internal major of cloned driver */
185
186 if (maj >= devcnt)
187 return (ENXIO);
188
189 /*
190 * NOTE We call ddi_hold_installed_driver() here to attach
191 * all instances of the driver, since we do not know
192 * a priori which instance the Stream is associated with.
193 *
194 * For Style-2 network drivers, we know that the association
195 * happens at DL_ATTACH time. For other types of drivers,
196 * open probably requires attaching instance 0 (pseudo dip).
197 *
198 * To eliminate ddi_hold_installed_driver(), the following
199 * should happen:
200 *
201 * - GLD be modified to include gld_init(). The driver will
202 * register information for gld_open() to succeed. It will
203 * also inform framework if driver assigns instance=PPA.
204 * - ddi_hold_devi_by_instance() be modified to actively
205 * attach the instance via top-down enumeration.
206 */
207 if (ddi_hold_installed_driver(maj) == NULL)
208 return (ENXIO);
209
210 if ((str = STREAMSTAB(maj)) == NULL) {
211 ddi_rele_driver(maj);
212 return (ENXIO);
213 }
214
215 newdev = makedevice(emaj, 0); /* create new style device number */
216
217 /*
218 * Check for security here. For DLPI style 2 network
219 * drivers, we need to apply the default network policy.
220 * Clone is weird in that the network driver isn't loaded
221 * and attached at spec_open() time, we need to load the
222 * driver to see if it is a network driver. Hence, we
223 * check security here (after ddi_hold_installed_driver
224 * call above).
225 */
226 vp = makespecvp(newdev, VCHR);
227 error = secpolicy_spec_open(crp, vp, flag);
228 VN_RELE(vp);
229 if (error) {
230 ddi_rele_driver(maj);
231 return (error);
232 }
233
234 /*
235 * Save so that we can restore the q on failure.
236 */
237 rinit = rq->q_qinfo;
238 winit = WR(rq)->q_qinfo;
239 ASSERT(rq->q_syncq->sq_type == (SQ_CI|SQ_CO));
240 ASSERT((rq->q_flag & QMT_TYPEMASK) == QMTSAFE);
241
242 dp = &devimpl[maj];
243 ASSERT(str == dp->d_str);
244
245 qflag = dp->d_qflag;
246 sqtype = dp->d_sqtype;
247
248 /* create perdm_t if needed */
249 if (NEED_DM(dp->d_dmp, qflag))
250 dp->d_dmp = hold_dm(str, qflag, sqtype);
251
252 dmp = dp->d_dmp;
253
254 /*
255 * Set the syncq state what qattach started off with. This is safe
256 * since no other thread can access this queue at this point
257 * (stream open, close, push, and pop are single threaded
258 * by the framework.)
259 */
260 leavesq(rq->q_syncq, SQ_OPENCLOSE);
261
262 /*
263 * Substitute the real qinit values for the current ones.
264 */
265 /* setq might sleep in kmem_alloc - avoid holding locks. */
266 setq(rq, str->st_rdinit, str->st_wrinit, dmp, qflag, sqtype, B_FALSE);
267
268 /*
269 * Open the attached module or driver.
270 *
271 * If there is an outer perimeter get exclusive access during
272 * the open procedure.
273 * Bump up the reference count on the queue.
274 */
275 entersq(rq->q_syncq, SQ_OPENCLOSE);
276
277 /*
278 * Call the device open with the stream flag CLONEOPEN. The device
279 * will either fail this or return the device number.
280 */
281 error = (*rq->q_qinfo->qi_qopen)(rq, &newdev, flag, CLONEOPEN, crp);
282 if (error != 0)
283 goto failed;
284
285 *devp = newdev;
286 if (getmajor(newdev) != emaj)
287 goto bad_major;
288
289 return (0);
290
291 bad_major:
292 /*
293 * Close the device
294 */
295 (*rq->q_qinfo->qi_qclose)(rq, flag, crp);
296
297 #ifdef DEBUG
298 cmn_err(CE_NOTE, "cannot clone major number %d(%s)->%d", emaj,
299 ddi_major_to_name(emaj), getmajor(newdev));
300 #endif
301 error = ENXIO;
302
303 failed:
304 /*
305 * open failed; pretty up to look like original
306 * queue.
307 */
308 if (backq(WR(rq)) && backq(WR(rq))->q_next == WR(rq))
309 qprocsoff(rq);
310 leavesq(rq->q_syncq, SQ_OPENCLOSE);
311 rq->q_next = WR(rq)->q_next = NULL;
312 ASSERT(flush_syncq(rq->q_syncq, rq) == 0);
313 ASSERT(flush_syncq(WR(rq)->q_syncq, WR(rq)) == 0);
314 rq->q_ptr = WR(rq)->q_ptr = NULL;
315 /* setq might sleep in kmem_alloc - avoid holding locks. */
316 setq(rq, rinit, winit, NULL, QMTSAFE, SQ_CI|SQ_CO,
317 B_FALSE);
318
319 /* Restore back to what qattach will expect */
320 entersq(rq->q_syncq, SQ_OPENCLOSE);
321
322 ddi_rele_driver(maj);
323 return (error);
324 }