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- (bal) Second around of UNICOS patches. A few other things left.
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8efc0c15 1/*
5260325f 2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
5260325f 3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 * All rights reserved
5260325f 5 * Allocating a pseudo-terminal, and making it the controlling tty.
6ae2364d 6 *
bcbf86ec 7 * As far as I am concerned, the code I have written for this software
8 * can be used freely for any purpose. Any derived versions of this
9 * software must be clearly marked as such, and if the derived work is
10 * incompatible with the protocol description in the RFC file, it must be
11 * called by a name other than "ssh" or "Secure Shell".
5260325f 12 */
8efc0c15 13
14#include "includes.h"
4f7893dc 15RCSID("$OpenBSD: sshpty.c,v 1.3 2001/07/22 21:32:27 markus Exp $");
8efc0c15 16
884bcb37 17#ifdef HAVE_UTIL_H
18# include <util.h>
19#endif /* HAVE_UTIL_H */
20
1729c161 21#include "sshpty.h"
42f11eb2 22#include "log.h"
5ad9f968 23#include "misc.h"
5260325f 24
8efc0c15 25/* Pty allocated with _getpty gets broken if we do I_PUSH:es to it. */
26#if defined(HAVE__GETPTY) || defined(HAVE_OPENPTY)
27#undef HAVE_DEV_PTMX
28#endif
29
6d8c4ea4 30#ifdef HAVE_PTY_H
31# include <pty.h>
32#endif
33#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
34# include <sys/stropts.h>
35#endif
36
8efc0c15 37#ifndef O_NOCTTY
38#define O_NOCTTY 0
39#endif
40
aa3378df 41/*
42 * Allocates and opens a pty. Returns 0 if no pty could be allocated, or
43 * nonzero if a pty was successfully allocated. On success, open file
44 * descriptors for the pty and tty sides and the name of the tty side are
45 * returned (the buffer must be able to hold at least 64 characters).
46 */
8efc0c15 47
6ae2364d 48int
a408af76 49pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, int namebuflen)
8efc0c15 50{
a408af76 51#if defined(HAVE_OPENPTY) || defined(BSD4_4)
5260325f 52 /* openpty(3) exists in OSF/1 and some other os'es */
b82f1310 53 char *name;
5260325f 54 int i;
8efc0c15 55
b82f1310 56 i = openpty(ptyfd, ttyfd, NULL, NULL, NULL);
5260325f 57 if (i < 0) {
58 error("openpty: %.100s", strerror(errno));
59 return 0;
60 }
b82f1310 61 name = ttyname(*ttyfd);
62 if (!name)
63 fatal("openpty returns device for which ttyname fails.");
64
65 strlcpy(namebuf, name, namebuflen); /* possible truncation */
5260325f 66 return 1;
8efc0c15 67#else /* HAVE_OPENPTY */
68#ifdef HAVE__GETPTY
aa3378df 69 /*
70 * _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more
71 * pty's automagically when needed
72 */
5260325f 73 char *slave;
74
75 slave = _getpty(ptyfd, O_RDWR, 0622, 0);
76 if (slave == NULL) {
77 error("_getpty: %.100s", strerror(errno));
78 return 0;
79 }
a408af76 80 strlcpy(namebuf, slave, namebuflen);
5260325f 81 /* Open the slave side. */
82 *ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
83 if (*ttyfd < 0) {
84 error("%.200s: %.100s", namebuf, strerror(errno));
85 close(*ptyfd);
86 return 0;
87 }
88 return 1;
8efc0c15 89#else /* HAVE__GETPTY */
a7effaac 90#if defined(HAVE_DEV_PTMX)
aa3378df 91 /*
92 * This code is used e.g. on Solaris 2.x. (Note that Solaris 2.3
93 * also has bsd-style ptys, but they simply do not work.)
94 */
5260325f 95 int ptm;
96 char *pts;
5ad9f968 97 mysig_t old_signal;
5260325f 98
99 ptm = open("/dev/ptmx", O_RDWR | O_NOCTTY);
100 if (ptm < 0) {
101 error("/dev/ptmx: %.100s", strerror(errno));
102 return 0;
103 }
5ad9f968 104 old_signal = mysignal(SIGCHLD, SIG_DFL);
5260325f 105 if (grantpt(ptm) < 0) {
106 error("grantpt: %.100s", strerror(errno));
107 return 0;
108 }
5ad9f968 109 mysignal(SIGCHLD, old_signal);
5260325f 110 if (unlockpt(ptm) < 0) {
111 error("unlockpt: %.100s", strerror(errno));
112 return 0;
113 }
114 pts = ptsname(ptm);
115 if (pts == NULL)
116 error("Slave pty side name could not be obtained.");
a408af76 117 strlcpy(namebuf, pts, namebuflen);
5260325f 118 *ptyfd = ptm;
119
120 /* Open the slave side. */
121 *ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
122 if (*ttyfd < 0) {
123 error("%.100s: %.100s", namebuf, strerror(errno));
124 close(*ptyfd);
125 return 0;
126 }
3c62e7eb 127#ifndef HAVE_CYGWIN
96054e6f 128 /*
129 * Push the appropriate streams modules, as described in Solaris pts(7).
130 * HP-UX pts(7) doesn't have ttcompat module.
131 */
5260325f 132 if (ioctl(*ttyfd, I_PUSH, "ptem") < 0)
133 error("ioctl I_PUSH ptem: %.100s", strerror(errno));
134 if (ioctl(*ttyfd, I_PUSH, "ldterm") < 0)
135 error("ioctl I_PUSH ldterm: %.100s", strerror(errno));
96054e6f 136#ifndef __hpux
5260325f 137 if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0)
138 error("ioctl I_PUSH ttcompat: %.100s", strerror(errno));
3c62e7eb 139#endif
be48d23c 140#endif
5260325f 141 return 1;
8efc0c15 142#else /* HAVE_DEV_PTMX */
143#ifdef HAVE_DEV_PTS_AND_PTC
5260325f 144 /* AIX-style pty code. */
145 const char *name;
8efc0c15 146
5260325f 147 *ptyfd = open("/dev/ptc", O_RDWR | O_NOCTTY);
148 if (*ptyfd < 0) {
149 error("Could not open /dev/ptc: %.100s", strerror(errno));
150 return 0;
151 }
152 name = ttyname(*ptyfd);
153 if (!name)
154 fatal("Open of /dev/ptc returns device for which ttyname fails.");
a408af76 155 strlcpy(namebuf, name, namebuflen);
5260325f 156 *ttyfd = open(name, O_RDWR | O_NOCTTY);
157 if (*ttyfd < 0) {
158 error("Could not open pty slave side %.100s: %.100s",
159 name, strerror(errno));
160 close(*ptyfd);
161 return 0;
162 }
163 return 1;
8efc0c15 164#else /* HAVE_DEV_PTS_AND_PTC */
1a23ac2c 165#ifdef _CRAY
166 char buf[64];
167 int i;
168 int highpty;
169
170#ifdef _SC_CRAY_NPTY
171 highpty = sysconf(_SC_CRAY_NPTY);
172 if (highpty == -1)
173 highpty = 128;
174#else
175 highpty = 128;
176#endif
177
178 for (i = 0; i < highpty; i++) {
179 snprintf(buf, sizeof(buf), "/dev/pty/%03d", i);
180 *ptyfd = open(buf, O_RDWR|O_NOCTTY);
181 if (*ptyfd < 0) continue;
182 snprintf(namebuf, namebuflen, "/dev/ttyp%03d", i);
183 /* Open the slave side. */
184 *ttyfd = open(namebuf, O_RDWR|O_NOCTTY);
185 if (*ttyfd < 0) {
186 error("%.100s: %.100s", namebuf, strerror(errno));
187 close(*ptyfd);
188 }
189 return 1;
190 }
191 return 0;
192#else
5260325f 193 /* BSD-style pty code. */
194 char buf[64];
195 int i;
aa3378df 196 const char *ptymajors = "pqrstuvwxyzabcdefghijklmnoABCDEFGHIJKLMNOPQRSTUVWXYZ";
5260325f 197 const char *ptyminors = "0123456789abcdef";
198 int num_minors = strlen(ptyminors);
199 int num_ptys = strlen(ptymajors) * num_minors;
200
201 for (i = 0; i < num_ptys; i++) {
202 snprintf(buf, sizeof buf, "/dev/pty%c%c", ptymajors[i / num_minors],
203 ptyminors[i % num_minors]);
95f1eccc 204 snprintf(namebuf, namebuflen, "/dev/tty%c%c",
a408af76 205 ptymajors[i / num_minors], ptyminors[i % num_minors]);
5260325f 206
b5f90139 207 *ptyfd = open(buf, O_RDWR | O_NOCTTY);
208 if (*ptyfd < 0) {
209 /* Try SCO style naming */
210 snprintf(buf, sizeof buf, "/dev/ptyp%d", i);
211 snprintf(namebuf, namebuflen, "/dev/ttyp%d", i);
212 *ptyfd = open(buf, O_RDWR | O_NOCTTY);
213 if (*ptyfd < 0)
214 continue;
2b87da3b 215 }
216
5260325f 217 /* Open the slave side. */
218 *ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
219 if (*ttyfd < 0) {
220 error("%.100s: %.100s", namebuf, strerror(errno));
221 close(*ptyfd);
222 return 0;
223 }
224 return 1;
8efc0c15 225 }
5260325f 226 return 0;
1a23ac2c 227#endif /* CRAY */
8efc0c15 228#endif /* HAVE_DEV_PTS_AND_PTC */
229#endif /* HAVE_DEV_PTMX */
230#endif /* HAVE__GETPTY */
231#endif /* HAVE_OPENPTY */
232}
233
5260325f 234/* Releases the tty. Its ownership is returned to root, and permissions to 0666. */
8efc0c15 235
6ae2364d 236void
5260325f 237pty_release(const char *ttyname)
8efc0c15 238{
3276571c 239 if (chown(ttyname, (uid_t) 0, (gid_t) 0) < 0)
817175bc 240 error("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno));
3276571c 241 if (chmod(ttyname, (mode_t) 0666) < 0)
817175bc 242 error("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno));
8efc0c15 243}
244
245/* Makes the tty the processes controlling tty and sets it to sane modes. */
246
6ae2364d 247void
5260325f 248pty_make_controlling_tty(int *ttyfd, const char *ttyname)
8efc0c15 249{
1a23ac2c 250#ifdef _CRAY
251 int fd;
252
253 if (setsid() < 0)
254 error("setsid: %.100s", strerror(errno));
255
256 fd = open(ttyname, O_RDWR|O_NOCTTY);
257 if (fd >= 0) {
258 signal(SIGHUP, SIG_IGN);
259 ioctl(fd, TCVHUP, (char *)0);
260 signal(SIGHUP, SIG_DFL);
261 setpgid(0,0);
262 close(fd);
263 } else {
264 error("Failed to disconnect from controlling tty.");
265 }
266
267
268 debug("Setting controlling tty using TCSETCTTY.\n");
269 ioctl(*ttyfd, TCSETCTTY, NULL);
270
271 fd = open("/dev/tty", O_RDWR);
272
273 if (fd < 0)
274 error("%.100s: %.100s", ttyname, strerror(errno));
275
276 close(*ttyfd);
277 *ttyfd = fd;
278#else
5260325f 279 int fd;
3c62e7eb 280#ifdef USE_VHANGUP
4e577b89 281 void *old;
3c62e7eb 282#endif /* USE_VHANGUP */
8efc0c15 283
5260325f 284 /* First disconnect from the old controlling tty. */
8efc0c15 285#ifdef TIOCNOTTY
5ca51e19 286 fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
5260325f 287 if (fd >= 0) {
288 (void) ioctl(fd, TIOCNOTTY, NULL);
289 close(fd);
290 }
8efc0c15 291#endif /* TIOCNOTTY */
5260325f 292 if (setsid() < 0)
293 error("setsid: %.100s", strerror(errno));
294
aa3378df 295 /*
296 * Verify that we are successfully disconnected from the controlling
297 * tty.
298 */
5ca51e19 299 fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
5260325f 300 if (fd >= 0) {
301 error("Failed to disconnect from controlling tty.");
302 close(fd);
303 }
304 /* Make it our controlling tty. */
8efc0c15 305#ifdef TIOCSCTTY
5260325f 306 debug("Setting controlling tty using TIOCSCTTY.");
a3bf38d0 307 if (ioctl(*ttyfd, TIOCSCTTY, NULL) < 0)
308 error("ioctl(TIOCSCTTY): %.100s", strerror(errno));
8efc0c15 309#endif /* TIOCSCTTY */
66d6c27e 310#ifdef HAVE_NEWS4
311 if (setpgrp(0,0) < 0)
312 error("SETPGRP %s",strerror(errno));
313#endif /* HAVE_NEWS4 */
3c62e7eb 314#ifdef USE_VHANGUP
4e577b89 315 old = signal(SIGHUP, SIG_IGN);
316 vhangup();
317 signal(SIGHUP, old);
3c62e7eb 318#endif /* USE_VHANGUP */
5260325f 319 fd = open(ttyname, O_RDWR);
4e577b89 320 if (fd < 0) {
5260325f 321 error("%.100s: %.100s", ttyname, strerror(errno));
4e577b89 322 } else {
3c62e7eb 323#ifdef USE_VHANGUP
4e577b89 324 close(*ttyfd);
325 *ttyfd = fd;
3c62e7eb 326#else /* USE_VHANGUP */
5260325f 327 close(fd);
3c62e7eb 328#endif /* USE_VHANGUP */
4e577b89 329 }
5260325f 330 /* Verify that we now have a controlling tty. */
5ca51e19 331 fd = open(_PATH_TTY, O_WRONLY);
5260325f 332 if (fd < 0)
333 error("open /dev/tty failed - could not set controlling tty: %.100s",
334 strerror(errno));
335 else {
336 close(fd);
337 }
1a23ac2c 338#endif
8efc0c15 339}
340
341/* Changes the window size associated with the pty. */
342
6ae2364d 343void
5260325f 344pty_change_window_size(int ptyfd, int row, int col,
345 int xpixel, int ypixel)
8efc0c15 346{
5260325f 347 struct winsize w;
348 w.ws_row = row;
349 w.ws_col = col;
350 w.ws_xpixel = xpixel;
351 w.ws_ypixel = ypixel;
352 (void) ioctl(ptyfd, TIOCSWINSZ, &w);
8efc0c15 353}
817175bc 354
355void
356pty_setowner(struct passwd *pw, const char *ttyname)
357{
358 struct group *grp;
359 gid_t gid;
360 mode_t mode;
227e8e86 361 struct stat st;
817175bc 362
363 /* Determine the group to make the owner of the tty. */
364 grp = getgrnam("tty");
365 if (grp) {
366 gid = grp->gr_gid;
367 mode = S_IRUSR | S_IWUSR | S_IWGRP;
368 } else {
369 gid = pw->pw_gid;
370 mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH;
371 }
372
227e8e86 373 /*
374 * Change owner and mode of the tty as required.
4f7893dc 375 * Warn but continue if filesystem is read-only and the uids match/
376 * tty is owned by root.
227e8e86 377 */
378 if (stat(ttyname, &st))
379 fatal("stat(%.100s) failed: %.100s", ttyname,
380 strerror(errno));
381
382 if (st.st_uid != pw->pw_uid || st.st_gid != gid) {
383 if (chown(ttyname, pw->pw_uid, gid) < 0) {
7458aff1 384 if (errno == EROFS &&
385 (st.st_uid == pw->pw_uid || st.st_uid == 0))
227e8e86 386 error("chown(%.100s, %d, %d) failed: %.100s",
2b87da3b 387 ttyname, pw->pw_uid, gid,
227e8e86 388 strerror(errno));
389 else
390 fatal("chown(%.100s, %d, %d) failed: %.100s",
2b87da3b 391 ttyname, pw->pw_uid, gid,
227e8e86 392 strerror(errno));
393 }
394 }
395
396 if ((st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) != mode) {
397 if (chmod(ttyname, mode) < 0) {
398 if (errno == EROFS &&
399 (st.st_mode & (S_IRGRP | S_IROTH)) == 0)
400 error("chmod(%.100s, 0%o) failed: %.100s",
401 ttyname, mode, strerror(errno));
402 else
403 fatal("chmod(%.100s, 0%o) failed: %.100s",
404 ttyname, mode, strerror(errno));
405 }
406 }
817175bc 407}
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