| 1 | /* $NetBSD: cons.c,v 1.75 2015/05/29 16:26:45 macallan Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 1988 University of Utah. |
| 5 | * Copyright (c) 1990, 1993 |
| 6 | * The Regents of the University of California. All rights reserved. |
| 7 | * |
| 8 | * This code is derived from software contributed to Berkeley by |
| 9 | * the Systems Programming Group of the University of Utah Computer |
| 10 | * Science Department. |
| 11 | * |
| 12 | * Redistribution and use in source and binary forms, with or without |
| 13 | * modification, are permitted provided that the following conditions |
| 14 | * are met: |
| 15 | * 1. Redistributions of source code must retain the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer. |
| 17 | * 2. Redistributions in binary form must reproduce the above copyright |
| 18 | * notice, this list of conditions and the following disclaimer in the |
| 19 | * documentation and/or other materials provided with the distribution. |
| 20 | * 3. Neither the name of the University nor the names of its contributors |
| 21 | * may be used to endorse or promote products derived from this software |
| 22 | * without specific prior written permission. |
| 23 | * |
| 24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 34 | * SUCH DAMAGE. |
| 35 | * |
| 36 | * from: Utah $Hdr: cons.c 1.7 92/01/21$ |
| 37 | * |
| 38 | * @(#)cons.c 8.2 (Berkeley) 1/12/94 |
| 39 | */ |
| 40 | |
| 41 | #include <sys/cdefs.h> |
| 42 | __KERNEL_RCSID(0, "$NetBSD: cons.c,v 1.75 2015/05/29 16:26:45 macallan Exp $" ); |
| 43 | |
| 44 | #include <sys/param.h> |
| 45 | #include <sys/proc.h> |
| 46 | #include <sys/systm.h> |
| 47 | #include <sys/buf.h> |
| 48 | #include <sys/ioctl.h> |
| 49 | #include <sys/poll.h> |
| 50 | #include <sys/tty.h> |
| 51 | #include <sys/file.h> |
| 52 | #include <sys/conf.h> |
| 53 | #include <sys/vnode.h> |
| 54 | #include <sys/kauth.h> |
| 55 | #include <sys/mutex.h> |
| 56 | |
| 57 | #include <dev/cons.h> |
| 58 | |
| 59 | #include "nullcons.h" |
| 60 | |
| 61 | dev_type_open(cnopen); |
| 62 | dev_type_close(cnclose); |
| 63 | dev_type_read(cnread); |
| 64 | dev_type_write(cnwrite); |
| 65 | dev_type_ioctl(cnioctl); |
| 66 | dev_type_poll(cnpoll); |
| 67 | dev_type_kqfilter(cnkqfilter); |
| 68 | |
| 69 | static bool cn_redirect(dev_t *, int, int *); |
| 70 | |
| 71 | const struct cdevsw cons_cdevsw = { |
| 72 | .d_open = cnopen, |
| 73 | .d_close = cnclose, |
| 74 | .d_read = cnread, |
| 75 | .d_write = cnwrite, |
| 76 | .d_ioctl = cnioctl, |
| 77 | .d_stop = nostop, |
| 78 | .d_tty = notty, |
| 79 | .d_poll = cnpoll, |
| 80 | .d_mmap = nommap, |
| 81 | .d_kqfilter = cnkqfilter, |
| 82 | .d_discard = nodiscard, |
| 83 | .d_flag = D_TTY |
| 84 | }; |
| 85 | |
| 86 | struct tty *constty = NULL; /* virtual console output device */ |
| 87 | struct consdev *cn_tab; /* physical console device info */ |
| 88 | struct vnode *cn_devvp[2]; /* vnode for underlying device. */ |
| 89 | |
| 90 | int |
| 91 | cnopen(dev_t dev, int flag, int mode, struct lwp *l) |
| 92 | { |
| 93 | dev_t cndev; |
| 94 | int unit, error; |
| 95 | |
| 96 | unit = minor(dev); |
| 97 | if (unit > 1) |
| 98 | return ENODEV; |
| 99 | |
| 100 | if (cn_tab == NULL) |
| 101 | return (0); |
| 102 | |
| 103 | /* |
| 104 | * always open the 'real' console device, so we don't get nailed |
| 105 | * later. This follows normal device semantics; they always get |
| 106 | * open() calls. |
| 107 | */ |
| 108 | cndev = cn_tab->cn_dev; |
| 109 | #if NNULLCONS > 0 |
| 110 | if (cndev == NODEV) { |
| 111 | nullconsattach(0); |
| 112 | } |
| 113 | #else /* NNULLCONS > 0 */ |
| 114 | if (cndev == NODEV) { |
| 115 | /* |
| 116 | * This is most likely an error in the console attach |
| 117 | * code. Panicking looks better than jumping into nowhere |
| 118 | * through cdevsw below.... |
| 119 | */ |
| 120 | panic("cnopen: no console device" ); |
| 121 | } |
| 122 | #endif /* NNULLCONS > 0 */ |
| 123 | if (dev == cndev) { |
| 124 | /* |
| 125 | * This causes cnopen() to be called recursively, which |
| 126 | * is generally a bad thing. It is often caused when |
| 127 | * dev == 0 and cn_dev has not been set, but was probably |
| 128 | * initialised to 0. |
| 129 | */ |
| 130 | panic("cnopen: cn_tab->cn_dev == dev" ); |
| 131 | } |
| 132 | if (cn_devvp[unit] != NULLVP) |
| 133 | return 0; |
| 134 | if ((error = cdevvp(cndev, &cn_devvp[unit])) != 0) |
| 135 | printf("cnopen: unable to get vnode reference\n" ); |
| 136 | error = vn_lock(cn_devvp[unit], LK_EXCLUSIVE | LK_RETRY); |
| 137 | if (error == 0) { |
| 138 | error = VOP_OPEN(cn_devvp[unit], flag, kauth_cred_get()); |
| 139 | VOP_UNLOCK(cn_devvp[unit]); |
| 140 | } |
| 141 | return error; |
| 142 | } |
| 143 | |
| 144 | int |
| 145 | cnclose(dev_t dev, int flag, int mode, struct lwp *l) |
| 146 | { |
| 147 | struct vnode *vp; |
| 148 | int unit, error; |
| 149 | |
| 150 | unit = minor(dev); |
| 151 | |
| 152 | if (cn_tab == NULL) |
| 153 | return (0); |
| 154 | |
| 155 | vp = cn_devvp[unit]; |
| 156 | cn_devvp[unit] = NULL; |
| 157 | error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
| 158 | if (error == 0) { |
| 159 | error = VOP_CLOSE(vp, flag, kauth_cred_get()); |
| 160 | VOP_UNLOCK(vp); |
| 161 | } |
| 162 | return error; |
| 163 | } |
| 164 | |
| 165 | int |
| 166 | cnread(dev_t dev, struct uio *uio, int flag) |
| 167 | { |
| 168 | int error; |
| 169 | |
| 170 | /* |
| 171 | * If we would redirect input, punt. This will keep strange |
| 172 | * things from happening to people who are using the real |
| 173 | * console. Nothing should be using /dev/console for |
| 174 | * input (except a shell in single-user mode, but then, |
| 175 | * one wouldn't TIOCCONS then). |
| 176 | */ |
| 177 | if (!cn_redirect(&dev, 1, &error)) |
| 178 | return error; |
| 179 | return cdev_read(dev, uio, flag); |
| 180 | } |
| 181 | |
| 182 | int |
| 183 | cnwrite(dev_t dev, struct uio *uio, int flag) |
| 184 | { |
| 185 | int error; |
| 186 | |
| 187 | /* Redirect output, if that's appropriate. */ |
| 188 | if (!cn_redirect(&dev, 0, &error)) |
| 189 | return error; |
| 190 | return cdev_write(dev, uio, flag); |
| 191 | } |
| 192 | |
| 193 | int |
| 194 | cnioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) |
| 195 | { |
| 196 | int error; |
| 197 | |
| 198 | error = 0; |
| 199 | |
| 200 | /* |
| 201 | * Superuser can always use this to wrest control of console |
| 202 | * output from the "virtual" console. |
| 203 | */ |
| 204 | if (cmd == TIOCCONS && constty != NULL) { |
| 205 | error = kauth_authorize_device_tty(l->l_cred, |
| 206 | KAUTH_DEVICE_TTY_VIRTUAL, constty); |
| 207 | if (!error) |
| 208 | constty = NULL; |
| 209 | return (error); |
| 210 | } |
| 211 | |
| 212 | /* |
| 213 | * Redirect the ioctl, if that's appropriate. |
| 214 | * Note that strange things can happen, if a program does |
| 215 | * ioctls on /dev/console, then the console is redirected |
| 216 | * out from under it. |
| 217 | */ |
| 218 | if (!cn_redirect(&dev, 0, &error)) |
| 219 | return error; |
| 220 | return cdev_ioctl(dev, cmd, data, flag, l); |
| 221 | } |
| 222 | |
| 223 | /*ARGSUSED*/ |
| 224 | int |
| 225 | cnpoll(dev_t dev, int events, struct lwp *l) |
| 226 | { |
| 227 | int error; |
| 228 | |
| 229 | /* |
| 230 | * Redirect the poll, if that's appropriate. |
| 231 | * I don't want to think of the possible side effects |
| 232 | * of console redirection here. |
| 233 | */ |
| 234 | if (!cn_redirect(&dev, 0, &error)) |
| 235 | return POLLHUP; |
| 236 | return cdev_poll(dev, events, l); |
| 237 | } |
| 238 | |
| 239 | /*ARGSUSED*/ |
| 240 | int |
| 241 | cnkqfilter(dev_t dev, struct knote *kn) |
| 242 | { |
| 243 | int error; |
| 244 | |
| 245 | /* |
| 246 | * Redirect the kqfilter, if that's appropriate. |
| 247 | * I don't want to think of the possible side effects |
| 248 | * of console redirection here. |
| 249 | */ |
| 250 | if (!cn_redirect(&dev, 0, &error)) |
| 251 | return error; |
| 252 | return cdev_kqfilter(dev, kn); |
| 253 | } |
| 254 | |
| 255 | int |
| 256 | cngetc(void) |
| 257 | { |
| 258 | if (cn_tab == NULL) |
| 259 | return (0); |
| 260 | int s = splhigh(); |
| 261 | for (;;) { |
| 262 | const int rv = (*cn_tab->cn_getc)(cn_tab->cn_dev); |
| 263 | if (rv >= 0) { |
| 264 | splx(s); |
| 265 | return rv; |
| 266 | } |
| 267 | docritpollhooks(); |
| 268 | } |
| 269 | } |
| 270 | |
| 271 | int |
| 272 | cngetsn(char *cp, int size) |
| 273 | { |
| 274 | char *lp; |
| 275 | int c, len; |
| 276 | |
| 277 | cnpollc(1); |
| 278 | |
| 279 | lp = cp; |
| 280 | len = 0; |
| 281 | for (;;) { |
| 282 | c = cngetc(); |
| 283 | switch (c) { |
| 284 | case '\n': |
| 285 | case '\r': |
| 286 | printf("\n" ); |
| 287 | *lp++ = '\0'; |
| 288 | cnpollc(0); |
| 289 | return (len); |
| 290 | case '\b': |
| 291 | case '\177': |
| 292 | case '#': |
| 293 | if (len) { |
| 294 | --len; |
| 295 | --lp; |
| 296 | printf("\b \b" ); |
| 297 | } |
| 298 | continue; |
| 299 | case '@': |
| 300 | case 'u'&037: /* CTRL-u */ |
| 301 | len = 0; |
| 302 | lp = cp; |
| 303 | printf("\n" ); |
| 304 | continue; |
| 305 | default: |
| 306 | if (len + 1 >= size || c < ' ') { |
| 307 | printf("\007" ); |
| 308 | continue; |
| 309 | } |
| 310 | printf("%c" , c); |
| 311 | ++len; |
| 312 | *lp++ = c; |
| 313 | } |
| 314 | } |
| 315 | } |
| 316 | |
| 317 | void |
| 318 | cnputc(int c) |
| 319 | { |
| 320 | |
| 321 | if (cn_tab == NULL) |
| 322 | return; |
| 323 | |
| 324 | /* |
| 325 | * XXX |
| 326 | * for some reason this causes ARCS firmware to output an endless stream of |
| 327 | * whitespaces with n32 kernels, so use the pre-1.74 code for now until I can |
| 328 | * figure out why this happens |
| 329 | */ |
| 330 | #ifndef sgimips |
| 331 | if (c) { |
| 332 | if (c == '\n') { |
| 333 | (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); |
| 334 | docritpollhooks(); |
| 335 | } |
| 336 | (*cn_tab->cn_putc)(cn_tab->cn_dev, c); |
| 337 | } |
| 338 | #else |
| 339 | if (c) { |
| 340 | (*cn_tab->cn_putc)(cn_tab->cn_dev, c); |
| 341 | if (c == '\n') { |
| 342 | docritpollhooks(); |
| 343 | (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); |
| 344 | } |
| 345 | } |
| 346 | #endif |
| 347 | } |
| 348 | |
| 349 | void |
| 350 | cnpollc(int on) |
| 351 | { |
| 352 | static int refcount = 0; |
| 353 | |
| 354 | if (cn_tab == NULL) |
| 355 | return; |
| 356 | if (!on) |
| 357 | --refcount; |
| 358 | if (refcount == 0) |
| 359 | (*cn_tab->cn_pollc)(cn_tab->cn_dev, on); |
| 360 | if (on) |
| 361 | ++refcount; |
| 362 | } |
| 363 | |
| 364 | void |
| 365 | nullcnpollc(dev_t dev, int on) |
| 366 | { |
| 367 | |
| 368 | } |
| 369 | |
| 370 | void |
| 371 | cnbell(u_int pitch, u_int period, u_int volume) |
| 372 | { |
| 373 | |
| 374 | if (cn_tab == NULL || cn_tab->cn_bell == NULL) |
| 375 | return; |
| 376 | (*cn_tab->cn_bell)(cn_tab->cn_dev, pitch, period, volume); |
| 377 | } |
| 378 | |
| 379 | void |
| 380 | cnflush(void) |
| 381 | { |
| 382 | if (cn_tab == NULL || cn_tab->cn_flush == NULL) |
| 383 | return; |
| 384 | (*cn_tab->cn_flush)(cn_tab->cn_dev); |
| 385 | } |
| 386 | |
| 387 | void |
| 388 | cnhalt(void) |
| 389 | { |
| 390 | if (cn_tab == NULL || cn_tab->cn_halt == NULL) |
| 391 | return; |
| 392 | (*cn_tab->cn_halt)(cn_tab->cn_dev); |
| 393 | } |
| 394 | |
| 395 | /* |
| 396 | * Redirect output, if that's appropriate. If there's no real console, |
| 397 | * return ENXIO. |
| 398 | * |
| 399 | * Call with tty_mutex held. |
| 400 | */ |
| 401 | static bool |
| 402 | cn_redirect(dev_t *devp, int is_read, int *error) |
| 403 | { |
| 404 | dev_t dev = *devp; |
| 405 | |
| 406 | *error = ENXIO; |
| 407 | if (constty != NULL && minor(dev) == 0 && |
| 408 | (cn_tab == NULL || (cn_tab->cn_pri != CN_REMOTE))) { |
| 409 | if (is_read) { |
| 410 | *error = 0; |
| 411 | return false; |
| 412 | } |
| 413 | dev = constty->t_dev; |
| 414 | } else if (cn_tab == NULL) |
| 415 | return false; |
| 416 | else |
| 417 | dev = cn_tab->cn_dev; |
| 418 | *devp = dev; |
| 419 | return true; |
| 420 | } |
| 421 | |