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 22 /* 23 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 /* 30 * Indirect console driver for Sun. 31 * 32 * Redirects all I/O to the device designated as the underlying "hardware" 33 * console, as given by the value of rconsvp. The implementation assumes that 34 * rconsvp denotes a STREAMS device; the assumption is justified since 35 * consoles must be capable of effecting tty semantics. 36 * 37 * rconsvp is set in autoconf.c:consconfig(), based on information obtained 38 * from the EEPROM. 39 * 40 * XXX: The driver still needs to be converted to use ANSI C consistently 41 * throughout. 42 */ 43 44 #include <sys/types.h> 45 #include <sys/open.h> 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/signal.h> 49 #include <sys/cred.h> 50 #include <sys/user.h> 51 #include <sys/proc.h> 52 #include <sys/disp.h> 53 #include <sys/file.h> 54 #include <sys/taskq.h> 55 #include <sys/log.h> 56 #include <sys/vnode.h> 57 #include <sys/uio.h> 58 #include <sys/stat.h> 59 60 #include <sys/console.h> 61 #include <sys/consdev.h> 62 63 #include <sys/stream.h> 64 #include <sys/strsubr.h> 65 #include <sys/poll.h> 66 67 #include <sys/debug.h> 68 69 #include <sys/conf.h> 70 #include <sys/ddi.h> 71 #include <sys/sunddi.h> 72 73 static int cnopen(dev_t *, int, int, struct cred *); 74 static int cnclose(dev_t, int, int, struct cred *); 75 static int cnread(dev_t, struct uio *, struct cred *); 76 static int cnwrite(dev_t, struct uio *, struct cred *); 77 static int cnioctl(dev_t, int, intptr_t, int, struct cred *, int *); 78 static int cnpoll(dev_t, short, int, short *, struct pollhead **); 79 static int cn_info(dev_info_t *, ddi_info_cmd_t, void *, void **); 80 static int cn_attach(dev_info_t *, ddi_attach_cmd_t); 81 static int cn_detach(dev_info_t *, ddi_detach_cmd_t); 82 83 static dev_info_t *cn_dip; /* private copy of devinfo pointer */ 84 85 static struct cb_ops cn_cb_ops = { 86 87 cnopen, /* open */ 88 cnclose, /* close */ 89 nodev, /* strategy */ 90 nodev, /* print */ 91 nodev, /* dump */ 92 cnread, /* read */ 93 cnwrite, /* write */ 94 cnioctl, /* ioctl */ 95 nodev, /* devmap */ 96 nodev, /* mmap */ 97 nodev, /* segmap */ 98 cnpoll, /* poll */ 99 ddi_prop_op, /* cb_prop_op */ 100 0, /* streamtab */ 101 D_NEW | D_MP /* Driver compatibility flag */ 102 103 }; 104 105 static struct dev_ops cn_ops = { 106 107 DEVO_REV, /* devo_rev, */ 108 0, /* refcnt */ 109 cn_info, /* info */ 110 nulldev, /* identify */ 111 nulldev, /* probe */ 112 cn_attach, /* attach */ 113 cn_detach, /* detach */ 114 nodev, /* reset */ 115 &cn_cb_ops, /* driver operations */ 116 (struct bus_ops *)0 /* bus operations */ 117 118 }; 119 120 /* 121 * Global variables associated with the console device: 122 * 123 * XXX: There are too many of these! 124 * moved to space.c to becone resident in the kernel so that cons 125 * can be loadable. 126 */ 127 128 extern dev_t rconsdev; /* "hardware" console */ 129 extern vnode_t *rconsvp; /* pointer to vnode for that device */ 130 131 /* 132 * XXX: consulted in prsubr.c, for /proc entry point for obtaining ps info. 133 */ 134 extern dev_t uconsdev; /* What the user thinks is the console device */ 135 136 /* 137 * Private driver state: 138 */ 139 140 /* 141 * The underlying console device potentially can be opened through (at least) 142 * two paths: through this driver and through the underlying device's driver. 143 * To ensure that reference counts are meaningful and therefore that close 144 * routines are called at the right time, it's important to make sure that 145 * rconsvp's s_count field (i.e., the count on the underlying device) never 146 * has a contribution of more than one through this driver, regardless of how 147 * many times this driver's been opened. rconsopen keeps track of the 148 * necessary information to ensure this property. 149 */ 150 static uint_t rconsopen; 151 152 153 #include <sys/types.h> 154 #include <sys/conf.h> 155 #include <sys/param.h> 156 #include <sys/systm.h> 157 #include <sys/errno.h> 158 #include <sys/modctl.h> 159 160 161 extern int nodev(), nulldev(); 162 extern int dseekneg_flag; 163 extern struct mod_ops mod_driverops; 164 extern struct dev_ops cn_ops; 165 166 /* 167 * Module linkage information for the kernel. 168 */ 169 170 static struct modldrv modldrv = { 171 &mod_driverops, /* Type of module. This one is a pseudo driver */ 172 "Console redirection driver %I%", 173 &cn_ops, /* driver ops */ 174 }; 175 176 static struct modlinkage modlinkage = { 177 MODREV_1, 178 &modldrv, 179 NULL 180 }; 181 182 int 183 _init(void) 184 { 185 return (mod_install(&modlinkage)); 186 } 187 188 int 189 _fini(void) 190 { 191 return (EBUSY); 192 } 193 194 int 195 _info(struct modinfo *modinfop) 196 { 197 return (mod_info(&modlinkage, modinfop)); 198 } 199 200 /* 201 * DDI glue routines 202 */ 203 static int 204 cn_attach(dev_info_t *devi, ddi_attach_cmd_t cmd) 205 { 206 if (cmd != DDI_ATTACH) 207 return (DDI_FAILURE); 208 209 if (ddi_create_minor_node(devi, "syscon", S_IFCHR, 210 0, DDI_PSEUDO, NULL) == DDI_FAILURE) { 211 return (DDI_FAILURE); 212 } 213 if (ddi_create_minor_node(devi, "systty", S_IFCHR, 214 0, DDI_PSEUDO, NULL) == DDI_FAILURE) { 215 ddi_remove_minor_node(devi, NULL); 216 return (DDI_FAILURE); 217 } 218 if (ddi_create_minor_node(devi, "console", S_IFCHR, 219 0, DDI_PSEUDO, NULL) == DDI_FAILURE) { 220 ddi_remove_minor_node(devi, NULL); 221 return (DDI_FAILURE); 222 } 223 cn_dip = devi; 224 return (DDI_SUCCESS); 225 } 226 227 static int 228 cn_detach(dev_info_t *devi, ddi_detach_cmd_t cmd) 229 { 230 if (cmd != DDI_DETACH) 231 return (DDI_FAILURE); 232 ddi_remove_minor_node(devi, NULL); 233 uconsdev = NODEV; 234 return (DDI_SUCCESS); 235 } 236 237 /* ARGSUSED */ 238 static int 239 cn_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result) 240 { 241 int error = DDI_FAILURE; 242 243 switch (infocmd) { 244 case DDI_INFO_DEVT2DEVINFO: 245 if (getminor((dev_t)arg) == 0 && cn_dip != NULL) { 246 *result = (void *) cn_dip; 247 error = DDI_SUCCESS; 248 } 249 break; 250 251 case DDI_INFO_DEVT2INSTANCE: 252 if (getminor((dev_t)arg) == 0) { 253 *result = (void *)0; 254 error = DDI_SUCCESS; 255 } 256 break; 257 258 default: 259 break; 260 } 261 262 return (error); 263 } 264 265 /* 266 * XXX Caution: before allowing more than 256 minor devices on the 267 * console, make sure you understand the 'compatibility' hack 268 * in ufs_iget() that translates old dev_t's to new dev_t's. 269 * See bugid 1098104 for the sordid details. 270 */ 271 272 /* ARGSUSED */ 273 static int 274 cnopen(dev_t *dev, int flag, int state, struct cred *cred) 275 { 276 int err; 277 static int been_here; 278 vnode_t *vp = rconsvp; 279 280 ASSERT(cred != NULL); 281 282 if (rconsvp == NULL) 283 return (0); 284 285 286 /* 287 * XXX: Clean up inactive PIDs from previous opens if any. 288 * These would have been created as a result of an I_SETSIG 289 * issued against console. This is a workaround, and 290 * console driver must be correctly redesigned not to need 291 * this hook. 292 */ 293 if (vp->v_stream) { 294 str_cn_clean(vp); 295 } 296 297 /* 298 * XXX: Set hook to tell /proc about underlying console. (There's 299 * gotta be a better way...) 300 */ 301 if (state != OTYP_CHR || getminor(*dev) != 0) 302 return (ENXIO); 303 if (been_here == 0) { 304 uconsdev = *dev; 305 been_here = 1; 306 if (vn_open("/dev/console", UIO_SYSSPACE, FWRITE | FNOCTTY, 307 0, &console_vnode, 0, 0) == 0) 308 console_taskq = taskq_create("console_taskq", 309 1, maxclsyspri - 1, LOG_LOWAT / LOG_MSGSIZE, 310 LOG_HIWAT / LOG_MSGSIZE, TASKQ_PREPOPULATE); 311 } 312 313 if ((err = VOP_OPEN(&vp, flag, cred)) != 0) 314 return (err); 315 316 /* 317 * The underlying driver is not allowed to have cloned itself 318 * for this open. 319 */ 320 if (vp != rconsvp) { 321 /* 322 * It might happen that someone set rconsvp to NULL 323 * whilst we were in the middle of the open. 324 */ 325 if (rconsvp == NULL) { 326 (void) VOP_CLOSE(vp, flag, 1, (offset_t)0, cred); 327 return (0); 328 } 329 cmn_err(CE_PANIC, "cnopen: cloned open"); 330 } 331 332 rconsopen++; 333 334 return (0); 335 } 336 337 /* ARGSUSED */ 338 static int 339 cnclose(dev_t dev, int flag, int state, struct cred *cred) 340 { 341 int err = 0; 342 vnode_t *vp; 343 344 /* 345 * Since this is the _last_ close, it's our last chance to close the 346 * underlying device. (Note that if someone else has the underlying 347 * hardware console device open, we won't get here, since spec_close 348 * will see s_count > 1.) 349 */ 350 if (state != OTYP_CHR) 351 return (ENXIO); 352 353 if (rconsvp == NULL) 354 return (0); 355 356 while ((rconsopen != 0) && ((vp = rconsvp) != NULL)) { 357 err = VOP_CLOSE(vp, flag, 1, (offset_t)0, cred); 358 if (!err) { 359 vp->v_stream = NULL; 360 rconsopen--; 361 } 362 } 363 return (err); 364 } 365 366 /* ARGSUSED */ 367 static int 368 cnread(dev_t dev, struct uio *uio, struct cred *cred) 369 { 370 kcondvar_t sleep_forever; 371 kmutex_t sleep_forever_mutex; 372 373 if (rconsvp == NULL) { 374 /* 375 * Go to sleep forever. This seems like the least 376 * harmful thing to do if there's no console. 377 * EOF might be better if we're ending up single-user 378 * mode. 379 */ 380 cv_init(&sleep_forever, NULL, CV_DRIVER, NULL); 381 mutex_init(&sleep_forever_mutex, NULL, MUTEX_DRIVER, NULL); 382 mutex_enter(&sleep_forever_mutex); 383 (void) cv_wait_sig(&sleep_forever, &sleep_forever_mutex); 384 mutex_exit(&sleep_forever_mutex); 385 return (EIO); 386 } 387 388 if (rconsvp->v_stream != NULL) 389 return (strread(rconsvp, uio, cred)); 390 else 391 return (cdev_read(rconsdev, uio, cred)); 392 } 393 394 /* ARGSUSED */ 395 static int 396 cnwrite(dev_t dev, struct uio *uio, struct cred *cred) 397 { 398 if (rconsvp == NULL) { 399 uio->uio_resid = 0; 400 return (0); 401 } 402 403 if (rconsvp->v_stream != NULL) 404 return (strwrite(rconsvp, uio, cred)); 405 else 406 return (cdev_write(rconsdev, uio, cred)); 407 } 408 409 /* ARGSUSED */ 410 static int 411 cnprivateioc(dev_t dev, int cmd, intptr_t arg, int flag, struct cred *cred, 412 int *rvalp) 413 { 414 415 /* currently we only support one ioctl */ 416 if (cmd != CONS_GETTERM) 417 return (EINVAL); 418 419 /* Confirm iwscn is immediate target of cn redirection */ 420 if (rconsvp != wsconsvp) 421 return (ENODEV); 422 423 /* 424 * If the redirection client is not wc, it should return 425 * error upon receiving the CONS_GETTERM ioctl. 426 * 427 * if it is wc, we know that the target supports the CONS_GETTERM 428 * ioctl, which very conviently has the exact same data 429 * format as this ioctl... so let's just pass it on. 430 */ 431 return (cdev_ioctl(rconsdev, CONS_GETTERM, arg, flag, cred, rvalp)); 432 } 433 434 /* ARGSUSED */ 435 static int 436 cnioctl(dev_t dev, int cmd, intptr_t arg, int flag, struct cred *cred, 437 int *rvalp) 438 { 439 if (rconsvp == NULL) 440 return (0); 441 442 if ((cmd & _CNIOC_MASK) == _CNIOC) 443 return (cnprivateioc(dev, cmd, arg, flag, cred, rvalp)); 444 else if (rconsvp->v_stream != NULL) 445 return (strioctl(rconsvp, cmd, arg, flag, U_TO_K, cred, 446 rvalp)); 447 else 448 return (cdev_ioctl(rconsdev, cmd, arg, flag, cred, rvalp)); 449 } 450 451 /* ARGSUSED */ 452 static int 453 cnpoll(dev_t dev, short events, int anyyet, short *reventsp, 454 struct pollhead **phpp) 455 { 456 if (rconsvp == NULL) 457 return (nochpoll(dev, events, anyyet, reventsp, phpp)); 458 459 if (rconsvp->v_stream != NULL) 460 return (strpoll(rconsvp->v_stream, events, anyyet, reventsp, 461 phpp)); 462 else 463 return (cdev_poll(rconsdev, events, anyyet, reventsp, phpp)); 464 } 465