tty_ptm.c revision 1.27 1 1.27 hannken /* $NetBSD: tty_ptm.c,v 1.27 2010/06/24 13:03:11 hannken Exp $ */
2 1.1 christos
3 1.1 christos /*-
4 1.1 christos * Copyright (c) 2004 The NetBSD Foundation, Inc.
5 1.1 christos * All rights reserved.
6 1.1 christos *
7 1.1 christos * Redistribution and use in source and binary forms, with or without
8 1.1 christos * modification, are permitted provided that the following conditions
9 1.1 christos * are met:
10 1.1 christos * 1. Redistributions of source code must retain the above copyright
11 1.1 christos * notice, this list of conditions and the following disclaimer.
12 1.1 christos * 2. Redistributions in binary form must reproduce the above copyright
13 1.1 christos * notice, this list of conditions and the following disclaimer in the
14 1.1 christos * documentation and/or other materials provided with the distribution.
15 1.1 christos *
16 1.1 christos * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 1.1 christos * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 1.1 christos * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 1.1 christos * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 1.1 christos * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 1.1 christos * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 1.1 christos * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 1.1 christos * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 1.1 christos * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 1.1 christos * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 1.1 christos * POSSIBILITY OF SUCH DAMAGE.
27 1.1 christos */
28 1.1 christos
29 1.1 christos #include <sys/cdefs.h>
30 1.27 hannken __KERNEL_RCSID(0, "$NetBSD: tty_ptm.c,v 1.27 2010/06/24 13:03:11 hannken Exp $");
31 1.1 christos
32 1.1 christos #include "opt_ptm.h"
33 1.1 christos
34 1.1 christos /* pty multiplexor driver /dev/ptm{,x} */
35 1.1 christos
36 1.1 christos #include <sys/param.h>
37 1.1 christos #include <sys/systm.h>
38 1.1 christos #include <sys/ioctl.h>
39 1.1 christos #include <sys/proc.h>
40 1.1 christos #include <sys/tty.h>
41 1.1 christos #include <sys/stat.h>
42 1.1 christos #include <sys/file.h>
43 1.1 christos #include <sys/uio.h>
44 1.1 christos #include <sys/kernel.h>
45 1.1 christos #include <sys/vnode.h>
46 1.1 christos #include <sys/namei.h>
47 1.1 christos #include <sys/signalvar.h>
48 1.1 christos #include <sys/filedesc.h>
49 1.1 christos #include <sys/conf.h>
50 1.1 christos #include <sys/poll.h>
51 1.1 christos #include <sys/pty.h>
52 1.9 elad #include <sys/kauth.h>
53 1.1 christos
54 1.23 ad #include <miscfs/specfs/specdev.h>
55 1.23 ad
56 1.1 christos #ifdef DEBUG_PTM
57 1.1 christos #define DPRINTF(a) printf a
58 1.1 christos #else
59 1.1 christos #define DPRINTF(a)
60 1.1 christos #endif
61 1.1 christos
62 1.1 christos #ifdef NO_DEV_PTM
63 1.1 christos const struct cdevsw ptm_cdevsw = {
64 1.1 christos noopen, noclose, noread, nowrite, noioctl,
65 1.1 christos nostop, notty, nopoll, nommap, nokqfilter, D_TTY
66 1.1 christos };
67 1.1 christos #else
68 1.1 christos
69 1.1 christos static struct ptm_pty *ptm;
70 1.1 christos int pts_major, ptc_major;
71 1.1 christos
72 1.1 christos static dev_t pty_getfree(void);
73 1.7 christos static int pty_alloc_master(struct lwp *, int *, dev_t *);
74 1.7 christos static int pty_alloc_slave(struct lwp *, int *, dev_t);
75 1.1 christos
76 1.1 christos void ptmattach(int);
77 1.1 christos
78 1.1 christos dev_t
79 1.1 christos pty_makedev(char ms, int minor)
80 1.1 christos {
81 1.1 christos return makedev(ms == 't' ? pts_major : ptc_major, minor);
82 1.1 christos }
83 1.1 christos
84 1.5 thorpej
85 1.1 christos static dev_t
86 1.1 christos pty_getfree(void)
87 1.1 christos {
88 1.18 ad extern kmutex_t pt_softc_mutex;
89 1.1 christos int i;
90 1.1 christos
91 1.18 ad mutex_enter(&pt_softc_mutex);
92 1.1 christos for (i = 0; i < npty; i++) {
93 1.1 christos if (pty_isfree(i, 0))
94 1.1 christos break;
95 1.1 christos }
96 1.18 ad mutex_exit(&pt_softc_mutex);
97 1.1 christos return pty_makedev('t', i);
98 1.1 christos }
99 1.1 christos
100 1.1 christos /*
101 1.1 christos * Hacked up version of vn_open. We _only_ handle ptys and only open
102 1.1 christos * them with FREAD|FWRITE and never deal with creat or stuff like that.
103 1.1 christos *
104 1.1 christos * We need it because we have to fake up root credentials to open the pty.
105 1.1 christos */
106 1.1 christos int
107 1.7 christos pty_vn_open(struct vnode *vp, struct lwp *l)
108 1.1 christos {
109 1.1 christos int error;
110 1.1 christos
111 1.1 christos if (vp->v_type != VCHR) {
112 1.1 christos vput(vp);
113 1.1 christos return EINVAL;
114 1.1 christos }
115 1.1 christos
116 1.21 pooka error = VOP_OPEN(vp, FREAD|FWRITE, lwp0.l_cred);
117 1.1 christos
118 1.1 christos if (error) {
119 1.1 christos vput(vp);
120 1.1 christos return error;
121 1.1 christos }
122 1.1 christos
123 1.1 christos vp->v_writecount++;
124 1.1 christos
125 1.1 christos return 0;
126 1.1 christos }
127 1.1 christos
128 1.1 christos static int
129 1.7 christos pty_alloc_master(struct lwp *l, int *fd, dev_t *dev)
130 1.1 christos {
131 1.1 christos int error;
132 1.1 christos struct file *fp;
133 1.1 christos struct vnode *vp;
134 1.1 christos int md;
135 1.1 christos
136 1.24 ad if ((error = fd_allocfile(&fp, fd)) != 0) {
137 1.24 ad DPRINTF(("fd_allocfile %d\n", error));
138 1.1 christos return error;
139 1.1 christos }
140 1.1 christos retry:
141 1.1 christos /* Find and open a free master pty. */
142 1.1 christos *dev = pty_getfree();
143 1.1 christos md = minor(*dev);
144 1.1 christos if ((error = pty_check(md)) != 0) {
145 1.1 christos DPRINTF(("pty_check %d\n", error));
146 1.1 christos goto bad;
147 1.1 christos }
148 1.1 christos if (ptm == NULL) {
149 1.13 christos DPRINTF(("no ptm\n"));
150 1.1 christos error = EOPNOTSUPP;
151 1.1 christos goto bad;
152 1.1 christos }
153 1.13 christos if ((error = (*ptm->allocvp)(ptm, l, &vp, *dev, 'p')) != 0) {
154 1.13 christos DPRINTF(("pty_allocvp %d\n", error));
155 1.1 christos goto bad;
156 1.13 christos }
157 1.1 christos
158 1.7 christos if ((error = pty_vn_open(vp, l)) != 0) {
159 1.13 christos DPRINTF(("pty_vn_open %d\n", error));
160 1.1 christos /*
161 1.1 christos * Check if the master open failed because we lost
162 1.1 christos * the race to grab it.
163 1.1 christos */
164 1.1 christos if (error != EIO)
165 1.1 christos goto bad;
166 1.1 christos error = !pty_isfree(md, 1);
167 1.13 christos DPRINTF(("pty_isfree %d\n", error));
168 1.1 christos if (error)
169 1.1 christos goto retry;
170 1.1 christos else
171 1.1 christos goto bad;
172 1.1 christos }
173 1.1 christos fp->f_flag = FREAD|FWRITE;
174 1.1 christos fp->f_type = DTYPE_VNODE;
175 1.1 christos fp->f_ops = &vnops;
176 1.1 christos fp->f_data = vp;
177 1.27 hannken VOP_UNLOCK(vp);
178 1.24 ad fd_affix(curproc, fp, *fd);
179 1.1 christos return 0;
180 1.1 christos bad:
181 1.24 ad fd_abort(curproc, fp, *fd);
182 1.1 christos return error;
183 1.1 christos }
184 1.1 christos
185 1.1 christos int
186 1.7 christos pty_grant_slave(struct lwp *l, dev_t dev)
187 1.1 christos {
188 1.1 christos int error;
189 1.1 christos struct vnode *vp;
190 1.1 christos
191 1.1 christos /*
192 1.1 christos * Open the slave.
193 1.1 christos * namei -> setattr -> unlock -> revoke -> vrele ->
194 1.1 christos * namei -> open -> unlock
195 1.1 christos * Three stage rocket:
196 1.1 christos * 1. Change the owner and permissions on the slave.
197 1.1 christos * 2. Revoke all the users of the slave.
198 1.1 christos * 3. open the slave.
199 1.1 christos */
200 1.1 christos if (ptm == NULL)
201 1.1 christos return EOPNOTSUPP;
202 1.7 christos if ((error = (*ptm->allocvp)(ptm, l, &vp, dev, 't')) != 0)
203 1.1 christos return error;
204 1.1 christos
205 1.1 christos if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
206 1.1 christos struct vattr vattr;
207 1.11 ad (*ptm->getvattr)(ptm, l, &vattr);
208 1.10 ad /* Do the VOP_SETATTR() as root. */
209 1.21 pooka error = VOP_SETATTR(vp, &vattr, lwp0.l_cred);
210 1.1 christos if (error) {
211 1.1 christos DPRINTF(("setattr %d\n", error));
212 1.27 hannken VOP_UNLOCK(vp);
213 1.1 christos vrele(vp);
214 1.1 christos return error;
215 1.1 christos }
216 1.1 christos }
217 1.27 hannken VOP_UNLOCK(vp);
218 1.23 ad VOP_REVOKE(vp, REVOKEALL);
219 1.1 christos
220 1.1 christos /*
221 1.1 christos * The vnode is useless after the revoke, we need to get it again.
222 1.1 christos */
223 1.1 christos vrele(vp);
224 1.1 christos return 0;
225 1.1 christos }
226 1.1 christos
227 1.1 christos static int
228 1.7 christos pty_alloc_slave(struct lwp *l, int *fd, dev_t dev)
229 1.1 christos {
230 1.1 christos int error;
231 1.1 christos struct file *fp;
232 1.1 christos struct vnode *vp;
233 1.1 christos
234 1.1 christos /* Grab a filedescriptor for the slave */
235 1.24 ad if ((error = fd_allocfile(&fp, fd)) != 0) {
236 1.24 ad DPRINTF(("fd_allocfile %d\n", error));
237 1.1 christos return error;
238 1.1 christos }
239 1.1 christos
240 1.1 christos if (ptm == NULL) {
241 1.1 christos error = EOPNOTSUPP;
242 1.1 christos goto bad;
243 1.1 christos }
244 1.1 christos
245 1.7 christos if ((error = (*ptm->allocvp)(ptm, l, &vp, dev, 't')) != 0)
246 1.1 christos goto bad;
247 1.7 christos if ((error = pty_vn_open(vp, l)) != 0)
248 1.1 christos goto bad;
249 1.1 christos
250 1.1 christos fp->f_flag = FREAD|FWRITE;
251 1.1 christos fp->f_type = DTYPE_VNODE;
252 1.1 christos fp->f_ops = &vnops;
253 1.1 christos fp->f_data = vp;
254 1.27 hannken VOP_UNLOCK(vp);
255 1.24 ad fd_affix(curproc, fp, *fd);
256 1.1 christos return 0;
257 1.1 christos bad:
258 1.24 ad fd_abort(curproc, fp, *fd);
259 1.1 christos return error;
260 1.1 christos }
261 1.1 christos
262 1.1 christos struct ptm_pty *
263 1.1 christos pty_sethandler(struct ptm_pty *nptm)
264 1.1 christos {
265 1.1 christos struct ptm_pty *optm = ptm;
266 1.1 christos ptm = nptm;
267 1.1 christos return optm;
268 1.1 christos }
269 1.1 christos
270 1.1 christos int
271 1.8 christos pty_fill_ptmget(struct lwp *l, dev_t dev, int cfd, int sfd, void *data)
272 1.1 christos {
273 1.1 christos struct ptmget *ptmg = data;
274 1.1 christos int error;
275 1.1 christos
276 1.1 christos if (ptm == NULL)
277 1.1 christos return EOPNOTSUPP;
278 1.1 christos
279 1.2 christos ptmg->cfd = cfd == -1 ? minor(dev) : cfd;
280 1.2 christos ptmg->sfd = sfd == -1 ? minor(dev) : sfd;
281 1.1 christos
282 1.8 christos error = (*ptm->makename)(ptm, l, ptmg->cn, sizeof(ptmg->cn), dev, 'p');
283 1.1 christos if (error)
284 1.1 christos return error;
285 1.1 christos
286 1.8 christos return (*ptm->makename)(ptm, l, ptmg->sn, sizeof(ptmg->sn), dev, 't');
287 1.1 christos }
288 1.1 christos
289 1.1 christos void
290 1.1 christos /*ARGSUSED*/
291 1.15 yamt ptmattach(int n)
292 1.1 christos {
293 1.1 christos extern const struct cdevsw pts_cdevsw, ptc_cdevsw;
294 1.1 christos /* find the major and minor of the pty devices */
295 1.1 christos if ((pts_major = cdevsw_lookup_major(&pts_cdevsw)) == -1)
296 1.1 christos panic("ptmattach: Can't find pty slave in cdevsw");
297 1.1 christos if ((ptc_major = cdevsw_lookup_major(&ptc_cdevsw)) == -1)
298 1.1 christos panic("ptmattach: Can't find pty master in cdevsw");
299 1.1 christos #ifdef COMPAT_BSDPTY
300 1.1 christos ptm = &ptm_bsdpty;
301 1.1 christos #endif
302 1.1 christos }
303 1.1 christos
304 1.5 thorpej static int
305 1.1 christos /*ARGSUSED*/
306 1.15 yamt ptmopen(dev_t dev, int flag, int mode, struct lwp *l)
307 1.1 christos {
308 1.1 christos int error;
309 1.1 christos int fd;
310 1.13 christos dev_t ttydev;
311 1.1 christos
312 1.1 christos switch(minor(dev)) {
313 1.1 christos case 0: /* /dev/ptmx */
314 1.12 christos case 2: /* /emul/linux/dev/ptmx */
315 1.13 christos if ((error = pty_alloc_master(l, &fd, &ttydev)) != 0)
316 1.1 christos return error;
317 1.12 christos if (minor(dev) == 2) {
318 1.12 christos /*
319 1.12 christos * Linux ptyfs grants the pty right here.
320 1.12 christos * Handle this case here, instead of writing
321 1.12 christos * a new linux module.
322 1.12 christos */
323 1.13 christos if ((error = pty_grant_slave(l, ttydev)) != 0) {
324 1.24 ad file_t *fp = fd_getfile(fd);
325 1.16 alc if (fp != NULL) {
326 1.24 ad fd_close(fd);
327 1.16 alc }
328 1.12 christos return error;
329 1.12 christos }
330 1.12 christos }
331 1.1 christos curlwp->l_dupfd = fd;
332 1.4 christos return EMOVEFD;
333 1.1 christos case 1: /* /dev/ptm */
334 1.1 christos return 0;
335 1.1 christos default:
336 1.1 christos return ENODEV;
337 1.1 christos }
338 1.1 christos }
339 1.1 christos
340 1.5 thorpej static int
341 1.1 christos /*ARGSUSED*/
342 1.15 yamt ptmclose(dev_t dev, int flag, int mode, struct lwp *l)
343 1.1 christos {
344 1.15 yamt
345 1.1 christos return (0);
346 1.1 christos }
347 1.1 christos
348 1.5 thorpej static int
349 1.1 christos /*ARGSUSED*/
350 1.17 christos ptmioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
351 1.1 christos {
352 1.1 christos int error;
353 1.1 christos dev_t newdev;
354 1.1 christos int cfd, sfd;
355 1.24 ad file_t *fp;
356 1.1 christos
357 1.1 christos error = 0;
358 1.1 christos switch (cmd) {
359 1.1 christos case TIOCPTMGET:
360 1.7 christos if ((error = pty_alloc_master(l, &cfd, &newdev)) != 0)
361 1.1 christos return error;
362 1.1 christos
363 1.7 christos if ((error = pty_grant_slave(l, newdev)) != 0)
364 1.1 christos goto bad;
365 1.1 christos
366 1.7 christos if ((error = pty_alloc_slave(l, &sfd, newdev)) != 0)
367 1.1 christos goto bad;
368 1.1 christos
369 1.1 christos /* now, put the indices and names into struct ptmget */
370 1.8 christos return pty_fill_ptmget(l, newdev, cfd, sfd, data);
371 1.1 christos default:
372 1.1 christos DPRINTF(("ptmioctl EINVAL\n"));
373 1.1 christos return EINVAL;
374 1.1 christos }
375 1.24 ad bad:
376 1.24 ad fp = fd_getfile(cfd);
377 1.16 alc if (fp != NULL) {
378 1.24 ad fd_close(cfd);
379 1.16 alc }
380 1.1 christos return error;
381 1.1 christos }
382 1.5 thorpej
383 1.5 thorpej const struct cdevsw ptm_cdevsw = {
384 1.5 thorpej ptmopen, ptmclose, noread, nowrite, ptmioctl,
385 1.5 thorpej nullstop, notty, nopoll, nommap, nokqfilter, D_TTY
386 1.5 thorpej };
387 1.6 he #endif
388