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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 | 15 | RCSID("$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 | 48 | int |
a408af76 | 49 | pty_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 | |
68187931 | 171 | highpty = sysconf(_SC_CRAY_NPTY); |
172 | if (highpty == -1) | |
173 | highpty = 128; | |
1a23ac2c | 174 | #else |
68187931 | 175 | highpty = 128; |
1a23ac2c | 176 | #endif |
177 | ||
68187931 | 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) | |
182 | continue; | |
183 | snprintf(namebuf, namebuflen, "/dev/ttyp%03d", i); | |
184 | /* Open the slave side. */ | |
185 | *ttyfd = open(namebuf, O_RDWR|O_NOCTTY); | |
186 | if (*ttyfd < 0) { | |
1a23ac2c | 187 | error("%.100s: %.100s", namebuf, strerror(errno)); |
68187931 | 188 | close(*ptyfd); |
5bd6962b | 189 | return 0; |
68187931 | 190 | } |
191 | return 1; | |
192 | } | |
193 | return 0; | |
1a23ac2c | 194 | #else |
5260325f | 195 | /* BSD-style pty code. */ |
196 | char buf[64]; | |
197 | int i; | |
aa3378df | 198 | const char *ptymajors = "pqrstuvwxyzabcdefghijklmnoABCDEFGHIJKLMNOPQRSTUVWXYZ"; |
5260325f | 199 | const char *ptyminors = "0123456789abcdef"; |
200 | int num_minors = strlen(ptyminors); | |
201 | int num_ptys = strlen(ptymajors) * num_minors; | |
202 | ||
203 | for (i = 0; i < num_ptys; i++) { | |
204 | snprintf(buf, sizeof buf, "/dev/pty%c%c", ptymajors[i / num_minors], | |
205 | ptyminors[i % num_minors]); | |
95f1eccc | 206 | snprintf(namebuf, namebuflen, "/dev/tty%c%c", |
a408af76 | 207 | ptymajors[i / num_minors], ptyminors[i % num_minors]); |
5260325f | 208 | |
b5f90139 | 209 | *ptyfd = open(buf, O_RDWR | O_NOCTTY); |
210 | if (*ptyfd < 0) { | |
211 | /* Try SCO style naming */ | |
212 | snprintf(buf, sizeof buf, "/dev/ptyp%d", i); | |
213 | snprintf(namebuf, namebuflen, "/dev/ttyp%d", i); | |
214 | *ptyfd = open(buf, O_RDWR | O_NOCTTY); | |
215 | if (*ptyfd < 0) | |
216 | continue; | |
2b87da3b | 217 | } |
218 | ||
5260325f | 219 | /* Open the slave side. */ |
220 | *ttyfd = open(namebuf, O_RDWR | O_NOCTTY); | |
221 | if (*ttyfd < 0) { | |
222 | error("%.100s: %.100s", namebuf, strerror(errno)); | |
223 | close(*ptyfd); | |
224 | return 0; | |
225 | } | |
226 | return 1; | |
8efc0c15 | 227 | } |
5260325f | 228 | return 0; |
1a23ac2c | 229 | #endif /* CRAY */ |
8efc0c15 | 230 | #endif /* HAVE_DEV_PTS_AND_PTC */ |
231 | #endif /* HAVE_DEV_PTMX */ | |
232 | #endif /* HAVE__GETPTY */ | |
233 | #endif /* HAVE_OPENPTY */ | |
234 | } | |
235 | ||
5260325f | 236 | /* Releases the tty. Its ownership is returned to root, and permissions to 0666. */ |
8efc0c15 | 237 | |
6ae2364d | 238 | void |
5260325f | 239 | pty_release(const char *ttyname) |
8efc0c15 | 240 | { |
3276571c | 241 | if (chown(ttyname, (uid_t) 0, (gid_t) 0) < 0) |
817175bc | 242 | error("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno)); |
3276571c | 243 | if (chmod(ttyname, (mode_t) 0666) < 0) |
817175bc | 244 | error("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno)); |
8efc0c15 | 245 | } |
246 | ||
247 | /* Makes the tty the processes controlling tty and sets it to sane modes. */ | |
248 | ||
6ae2364d | 249 | void |
5260325f | 250 | pty_make_controlling_tty(int *ttyfd, const char *ttyname) |
8efc0c15 | 251 | { |
1a23ac2c | 252 | #ifdef _CRAY |
253 | int fd; | |
254 | ||
68187931 | 255 | if (setsid() < 0) |
256 | error("setsid: %.100s", strerror(errno)); | |
1a23ac2c | 257 | |
68187931 | 258 | fd = open(ttyname, O_RDWR|O_NOCTTY); |
259 | if (fd != -1) { | |
260 | signal(SIGHUP, SIG_IGN); | |
261 | ioctl(fd, TCVHUP, (char *)NULL); | |
262 | signal(SIGHUP, SIG_DFL); | |
263 | setpgid(0, 0); | |
264 | close(fd); | |
1a23ac2c | 265 | } else { |
68187931 | 266 | error("Failed to disconnect from controlling tty."); |
1a23ac2c | 267 | } |
1a23ac2c | 268 | |
68187931 | 269 | debug("Setting controlling tty using TCSETCTTY."); |
270 | ioctl(*ttyfd, TCSETCTTY, NULL); | |
271 | fd = open("/dev/tty", O_RDWR); | |
272 | if (fd < 0) | |
273 | error("%.100s: %.100s", ttyname, strerror(errno)); | |
1a23ac2c | 274 | close(*ttyfd); |
275 | *ttyfd = fd; | |
276 | #else | |
5260325f | 277 | int fd; |
3c62e7eb | 278 | #ifdef USE_VHANGUP |
4e577b89 | 279 | void *old; |
3c62e7eb | 280 | #endif /* USE_VHANGUP */ |
8efc0c15 | 281 | |
5260325f | 282 | /* First disconnect from the old controlling tty. */ |
8efc0c15 | 283 | #ifdef TIOCNOTTY |
5ca51e19 | 284 | fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); |
5260325f | 285 | if (fd >= 0) { |
286 | (void) ioctl(fd, TIOCNOTTY, NULL); | |
287 | close(fd); | |
288 | } | |
8efc0c15 | 289 | #endif /* TIOCNOTTY */ |
5260325f | 290 | if (setsid() < 0) |
291 | error("setsid: %.100s", strerror(errno)); | |
292 | ||
aa3378df | 293 | /* |
294 | * Verify that we are successfully disconnected from the controlling | |
295 | * tty. | |
296 | */ | |
5ca51e19 | 297 | fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); |
5260325f | 298 | if (fd >= 0) { |
299 | error("Failed to disconnect from controlling tty."); | |
300 | close(fd); | |
301 | } | |
302 | /* Make it our controlling tty. */ | |
8efc0c15 | 303 | #ifdef TIOCSCTTY |
5260325f | 304 | debug("Setting controlling tty using TIOCSCTTY."); |
a3bf38d0 | 305 | if (ioctl(*ttyfd, TIOCSCTTY, NULL) < 0) |
306 | error("ioctl(TIOCSCTTY): %.100s", strerror(errno)); | |
8efc0c15 | 307 | #endif /* TIOCSCTTY */ |
66d6c27e | 308 | #ifdef HAVE_NEWS4 |
309 | if (setpgrp(0,0) < 0) | |
310 | error("SETPGRP %s",strerror(errno)); | |
311 | #endif /* HAVE_NEWS4 */ | |
3c62e7eb | 312 | #ifdef USE_VHANGUP |
4e577b89 | 313 | old = signal(SIGHUP, SIG_IGN); |
314 | vhangup(); | |
315 | signal(SIGHUP, old); | |
3c62e7eb | 316 | #endif /* USE_VHANGUP */ |
5260325f | 317 | fd = open(ttyname, O_RDWR); |
4e577b89 | 318 | if (fd < 0) { |
5260325f | 319 | error("%.100s: %.100s", ttyname, strerror(errno)); |
4e577b89 | 320 | } else { |
3c62e7eb | 321 | #ifdef USE_VHANGUP |
4e577b89 | 322 | close(*ttyfd); |
323 | *ttyfd = fd; | |
3c62e7eb | 324 | #else /* USE_VHANGUP */ |
5260325f | 325 | close(fd); |
3c62e7eb | 326 | #endif /* USE_VHANGUP */ |
4e577b89 | 327 | } |
5260325f | 328 | /* Verify that we now have a controlling tty. */ |
5ca51e19 | 329 | fd = open(_PATH_TTY, O_WRONLY); |
5260325f | 330 | if (fd < 0) |
331 | error("open /dev/tty failed - could not set controlling tty: %.100s", | |
332 | strerror(errno)); | |
333 | else { | |
334 | close(fd); | |
335 | } | |
1a23ac2c | 336 | #endif |
8efc0c15 | 337 | } |
338 | ||
339 | /* Changes the window size associated with the pty. */ | |
340 | ||
6ae2364d | 341 | void |
5260325f | 342 | pty_change_window_size(int ptyfd, int row, int col, |
343 | int xpixel, int ypixel) | |
8efc0c15 | 344 | { |
5260325f | 345 | struct winsize w; |
346 | w.ws_row = row; | |
347 | w.ws_col = col; | |
348 | w.ws_xpixel = xpixel; | |
349 | w.ws_ypixel = ypixel; | |
350 | (void) ioctl(ptyfd, TIOCSWINSZ, &w); | |
8efc0c15 | 351 | } |
817175bc | 352 | |
353 | void | |
354 | pty_setowner(struct passwd *pw, const char *ttyname) | |
355 | { | |
356 | struct group *grp; | |
357 | gid_t gid; | |
358 | mode_t mode; | |
227e8e86 | 359 | struct stat st; |
817175bc | 360 | |
361 | /* Determine the group to make the owner of the tty. */ | |
362 | grp = getgrnam("tty"); | |
363 | if (grp) { | |
364 | gid = grp->gr_gid; | |
365 | mode = S_IRUSR | S_IWUSR | S_IWGRP; | |
366 | } else { | |
367 | gid = pw->pw_gid; | |
368 | mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH; | |
369 | } | |
370 | ||
227e8e86 | 371 | /* |
372 | * Change owner and mode of the tty as required. | |
4f7893dc | 373 | * Warn but continue if filesystem is read-only and the uids match/ |
374 | * tty is owned by root. | |
227e8e86 | 375 | */ |
376 | if (stat(ttyname, &st)) | |
377 | fatal("stat(%.100s) failed: %.100s", ttyname, | |
378 | strerror(errno)); | |
379 | ||
380 | if (st.st_uid != pw->pw_uid || st.st_gid != gid) { | |
381 | if (chown(ttyname, pw->pw_uid, gid) < 0) { | |
7458aff1 | 382 | if (errno == EROFS && |
383 | (st.st_uid == pw->pw_uid || st.st_uid == 0)) | |
227e8e86 | 384 | error("chown(%.100s, %d, %d) failed: %.100s", |
2b87da3b | 385 | ttyname, pw->pw_uid, gid, |
227e8e86 | 386 | strerror(errno)); |
387 | else | |
388 | fatal("chown(%.100s, %d, %d) failed: %.100s", | |
2b87da3b | 389 | ttyname, pw->pw_uid, gid, |
227e8e86 | 390 | strerror(errno)); |
391 | } | |
392 | } | |
393 | ||
394 | if ((st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) != mode) { | |
395 | if (chmod(ttyname, mode) < 0) { | |
396 | if (errno == EROFS && | |
397 | (st.st_mode & (S_IRGRP | S_IROTH)) == 0) | |
398 | error("chmod(%.100s, 0%o) failed: %.100s", | |
399 | ttyname, mode, strerror(errno)); | |
400 | else | |
401 | fatal("chmod(%.100s, 0%o) failed: %.100s", | |
402 | ttyname, mode, strerror(errno)); | |
403 | } | |
404 | } | |
817175bc | 405 | } |