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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" | |
5ca51e19 | 15 | RCSID("$OpenBSD: pty.c,v 1.22 2001/02/08 19:30:52 itojun 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" |
5260325f | 23 | |
8efc0c15 | 24 | /* Pty allocated with _getpty gets broken if we do I_PUSH:es to it. */ |
25 | #if defined(HAVE__GETPTY) || defined(HAVE_OPENPTY) | |
26 | #undef HAVE_DEV_PTMX | |
27 | #endif | |
28 | ||
6d8c4ea4 | 29 | #ifdef HAVE_PTY_H |
30 | # include <pty.h> | |
31 | #endif | |
32 | #if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H) | |
33 | # include <sys/stropts.h> | |
34 | #endif | |
35 | ||
8efc0c15 | 36 | #ifndef O_NOCTTY |
37 | #define O_NOCTTY 0 | |
38 | #endif | |
39 | ||
aa3378df | 40 | /* |
41 | * Allocates and opens a pty. Returns 0 if no pty could be allocated, or | |
42 | * nonzero if a pty was successfully allocated. On success, open file | |
43 | * descriptors for the pty and tty sides and the name of the tty side are | |
44 | * returned (the buffer must be able to hold at least 64 characters). | |
45 | */ | |
8efc0c15 | 46 | |
6ae2364d | 47 | int |
a408af76 | 48 | pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, int namebuflen) |
8efc0c15 | 49 | { |
a408af76 | 50 | #if defined(HAVE_OPENPTY) || defined(BSD4_4) |
5260325f | 51 | /* openpty(3) exists in OSF/1 and some other os'es */ |
b82f1310 | 52 | char *name; |
5260325f | 53 | int i; |
8efc0c15 | 54 | |
b82f1310 | 55 | i = openpty(ptyfd, ttyfd, NULL, NULL, NULL); |
5260325f | 56 | if (i < 0) { |
57 | error("openpty: %.100s", strerror(errno)); | |
58 | return 0; | |
59 | } | |
b82f1310 | 60 | name = ttyname(*ttyfd); |
61 | if (!name) | |
62 | fatal("openpty returns device for which ttyname fails."); | |
63 | ||
64 | strlcpy(namebuf, name, namebuflen); /* possible truncation */ | |
5260325f | 65 | return 1; |
8efc0c15 | 66 | #else /* HAVE_OPENPTY */ |
67 | #ifdef HAVE__GETPTY | |
aa3378df | 68 | /* |
69 | * _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more | |
70 | * pty's automagically when needed | |
71 | */ | |
5260325f | 72 | char *slave; |
73 | ||
74 | slave = _getpty(ptyfd, O_RDWR, 0622, 0); | |
75 | if (slave == NULL) { | |
76 | error("_getpty: %.100s", strerror(errno)); | |
77 | return 0; | |
78 | } | |
a408af76 | 79 | strlcpy(namebuf, slave, namebuflen); |
5260325f | 80 | /* Open the slave side. */ |
81 | *ttyfd = open(namebuf, O_RDWR | O_NOCTTY); | |
82 | if (*ttyfd < 0) { | |
83 | error("%.200s: %.100s", namebuf, strerror(errno)); | |
84 | close(*ptyfd); | |
85 | return 0; | |
86 | } | |
87 | return 1; | |
8efc0c15 | 88 | #else /* HAVE__GETPTY */ |
a7effaac | 89 | #if defined(HAVE_DEV_PTMX) |
aa3378df | 90 | /* |
91 | * This code is used e.g. on Solaris 2.x. (Note that Solaris 2.3 | |
92 | * also has bsd-style ptys, but they simply do not work.) | |
93 | */ | |
5260325f | 94 | int ptm; |
95 | char *pts; | |
96 | ||
97 | ptm = open("/dev/ptmx", O_RDWR | O_NOCTTY); | |
98 | if (ptm < 0) { | |
99 | error("/dev/ptmx: %.100s", strerror(errno)); | |
100 | return 0; | |
101 | } | |
102 | if (grantpt(ptm) < 0) { | |
103 | error("grantpt: %.100s", strerror(errno)); | |
104 | return 0; | |
105 | } | |
106 | if (unlockpt(ptm) < 0) { | |
107 | error("unlockpt: %.100s", strerror(errno)); | |
108 | return 0; | |
109 | } | |
110 | pts = ptsname(ptm); | |
111 | if (pts == NULL) | |
112 | error("Slave pty side name could not be obtained."); | |
a408af76 | 113 | strlcpy(namebuf, pts, namebuflen); |
5260325f | 114 | *ptyfd = ptm; |
115 | ||
116 | /* Open the slave side. */ | |
117 | *ttyfd = open(namebuf, O_RDWR | O_NOCTTY); | |
118 | if (*ttyfd < 0) { | |
119 | error("%.100s: %.100s", namebuf, strerror(errno)); | |
120 | close(*ptyfd); | |
121 | return 0; | |
122 | } | |
3c62e7eb | 123 | #ifndef HAVE_CYGWIN |
96054e6f | 124 | /* |
125 | * Push the appropriate streams modules, as described in Solaris pts(7). | |
126 | * HP-UX pts(7) doesn't have ttcompat module. | |
127 | */ | |
5260325f | 128 | if (ioctl(*ttyfd, I_PUSH, "ptem") < 0) |
129 | error("ioctl I_PUSH ptem: %.100s", strerror(errno)); | |
130 | if (ioctl(*ttyfd, I_PUSH, "ldterm") < 0) | |
131 | error("ioctl I_PUSH ldterm: %.100s", strerror(errno)); | |
96054e6f | 132 | #ifndef __hpux |
5260325f | 133 | if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0) |
134 | error("ioctl I_PUSH ttcompat: %.100s", strerror(errno)); | |
3c62e7eb | 135 | #endif |
be48d23c | 136 | #endif |
5260325f | 137 | return 1; |
8efc0c15 | 138 | #else /* HAVE_DEV_PTMX */ |
139 | #ifdef HAVE_DEV_PTS_AND_PTC | |
5260325f | 140 | /* AIX-style pty code. */ |
141 | const char *name; | |
8efc0c15 | 142 | |
5260325f | 143 | *ptyfd = open("/dev/ptc", O_RDWR | O_NOCTTY); |
144 | if (*ptyfd < 0) { | |
145 | error("Could not open /dev/ptc: %.100s", strerror(errno)); | |
146 | return 0; | |
147 | } | |
148 | name = ttyname(*ptyfd); | |
149 | if (!name) | |
150 | fatal("Open of /dev/ptc returns device for which ttyname fails."); | |
a408af76 | 151 | strlcpy(namebuf, name, namebuflen); |
5260325f | 152 | *ttyfd = open(name, O_RDWR | O_NOCTTY); |
153 | if (*ttyfd < 0) { | |
154 | error("Could not open pty slave side %.100s: %.100s", | |
155 | name, strerror(errno)); | |
156 | close(*ptyfd); | |
157 | return 0; | |
158 | } | |
159 | return 1; | |
8efc0c15 | 160 | #else /* HAVE_DEV_PTS_AND_PTC */ |
5260325f | 161 | /* BSD-style pty code. */ |
162 | char buf[64]; | |
163 | int i; | |
aa3378df | 164 | const char *ptymajors = "pqrstuvwxyzabcdefghijklmnoABCDEFGHIJKLMNOPQRSTUVWXYZ"; |
5260325f | 165 | const char *ptyminors = "0123456789abcdef"; |
166 | int num_minors = strlen(ptyminors); | |
167 | int num_ptys = strlen(ptymajors) * num_minors; | |
168 | ||
169 | for (i = 0; i < num_ptys; i++) { | |
170 | snprintf(buf, sizeof buf, "/dev/pty%c%c", ptymajors[i / num_minors], | |
171 | ptyminors[i % num_minors]); | |
95f1eccc | 172 | snprintf(namebuf, namebuflen, "/dev/tty%c%c", |
a408af76 | 173 | ptymajors[i / num_minors], ptyminors[i % num_minors]); |
5260325f | 174 | |
b5f90139 | 175 | *ptyfd = open(buf, O_RDWR | O_NOCTTY); |
176 | if (*ptyfd < 0) { | |
177 | /* Try SCO style naming */ | |
178 | snprintf(buf, sizeof buf, "/dev/ptyp%d", i); | |
179 | snprintf(namebuf, namebuflen, "/dev/ttyp%d", i); | |
180 | *ptyfd = open(buf, O_RDWR | O_NOCTTY); | |
181 | if (*ptyfd < 0) | |
182 | continue; | |
2b87da3b | 183 | } |
184 | ||
5260325f | 185 | /* Open the slave side. */ |
186 | *ttyfd = open(namebuf, O_RDWR | O_NOCTTY); | |
187 | if (*ttyfd < 0) { | |
188 | error("%.100s: %.100s", namebuf, strerror(errno)); | |
189 | close(*ptyfd); | |
190 | return 0; | |
191 | } | |
192 | return 1; | |
8efc0c15 | 193 | } |
5260325f | 194 | return 0; |
8efc0c15 | 195 | #endif /* HAVE_DEV_PTS_AND_PTC */ |
196 | #endif /* HAVE_DEV_PTMX */ | |
197 | #endif /* HAVE__GETPTY */ | |
198 | #endif /* HAVE_OPENPTY */ | |
199 | } | |
200 | ||
5260325f | 201 | /* Releases the tty. Its ownership is returned to root, and permissions to 0666. */ |
8efc0c15 | 202 | |
6ae2364d | 203 | void |
5260325f | 204 | pty_release(const char *ttyname) |
8efc0c15 | 205 | { |
3276571c | 206 | if (chown(ttyname, (uid_t) 0, (gid_t) 0) < 0) |
817175bc | 207 | error("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno)); |
3276571c | 208 | if (chmod(ttyname, (mode_t) 0666) < 0) |
817175bc | 209 | error("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno)); |
8efc0c15 | 210 | } |
211 | ||
212 | /* Makes the tty the processes controlling tty and sets it to sane modes. */ | |
213 | ||
6ae2364d | 214 | void |
5260325f | 215 | pty_make_controlling_tty(int *ttyfd, const char *ttyname) |
8efc0c15 | 216 | { |
5260325f | 217 | int fd; |
3c62e7eb | 218 | #ifdef USE_VHANGUP |
4e577b89 | 219 | void *old; |
3c62e7eb | 220 | #endif /* USE_VHANGUP */ |
8efc0c15 | 221 | |
5260325f | 222 | /* First disconnect from the old controlling tty. */ |
8efc0c15 | 223 | #ifdef TIOCNOTTY |
5ca51e19 | 224 | fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); |
5260325f | 225 | if (fd >= 0) { |
226 | (void) ioctl(fd, TIOCNOTTY, NULL); | |
227 | close(fd); | |
228 | } | |
8efc0c15 | 229 | #endif /* TIOCNOTTY */ |
5260325f | 230 | if (setsid() < 0) |
231 | error("setsid: %.100s", strerror(errno)); | |
232 | ||
aa3378df | 233 | /* |
234 | * Verify that we are successfully disconnected from the controlling | |
235 | * tty. | |
236 | */ | |
5ca51e19 | 237 | fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); |
5260325f | 238 | if (fd >= 0) { |
239 | error("Failed to disconnect from controlling tty."); | |
240 | close(fd); | |
241 | } | |
242 | /* Make it our controlling tty. */ | |
8efc0c15 | 243 | #ifdef TIOCSCTTY |
5260325f | 244 | debug("Setting controlling tty using TIOCSCTTY."); |
a3bf38d0 | 245 | if (ioctl(*ttyfd, TIOCSCTTY, NULL) < 0) |
246 | error("ioctl(TIOCSCTTY): %.100s", strerror(errno)); | |
8efc0c15 | 247 | #endif /* TIOCSCTTY */ |
66d6c27e | 248 | #ifdef HAVE_NEWS4 |
249 | if (setpgrp(0,0) < 0) | |
250 | error("SETPGRP %s",strerror(errno)); | |
251 | #endif /* HAVE_NEWS4 */ | |
3c62e7eb | 252 | #ifdef USE_VHANGUP |
4e577b89 | 253 | old = signal(SIGHUP, SIG_IGN); |
254 | vhangup(); | |
255 | signal(SIGHUP, old); | |
3c62e7eb | 256 | #endif /* USE_VHANGUP */ |
5260325f | 257 | fd = open(ttyname, O_RDWR); |
4e577b89 | 258 | if (fd < 0) { |
5260325f | 259 | error("%.100s: %.100s", ttyname, strerror(errno)); |
4e577b89 | 260 | } else { |
3c62e7eb | 261 | #ifdef USE_VHANGUP |
4e577b89 | 262 | close(*ttyfd); |
263 | *ttyfd = fd; | |
3c62e7eb | 264 | #else /* USE_VHANGUP */ |
5260325f | 265 | close(fd); |
3c62e7eb | 266 | #endif /* USE_VHANGUP */ |
4e577b89 | 267 | } |
5260325f | 268 | /* Verify that we now have a controlling tty. */ |
5ca51e19 | 269 | fd = open(_PATH_TTY, O_WRONLY); |
5260325f | 270 | if (fd < 0) |
271 | error("open /dev/tty failed - could not set controlling tty: %.100s", | |
272 | strerror(errno)); | |
273 | else { | |
274 | close(fd); | |
275 | } | |
8efc0c15 | 276 | } |
277 | ||
278 | /* Changes the window size associated with the pty. */ | |
279 | ||
6ae2364d | 280 | void |
5260325f | 281 | pty_change_window_size(int ptyfd, int row, int col, |
282 | int xpixel, int ypixel) | |
8efc0c15 | 283 | { |
5260325f | 284 | struct winsize w; |
285 | w.ws_row = row; | |
286 | w.ws_col = col; | |
287 | w.ws_xpixel = xpixel; | |
288 | w.ws_ypixel = ypixel; | |
289 | (void) ioctl(ptyfd, TIOCSWINSZ, &w); | |
8efc0c15 | 290 | } |
817175bc | 291 | |
292 | void | |
293 | pty_setowner(struct passwd *pw, const char *ttyname) | |
294 | { | |
295 | struct group *grp; | |
296 | gid_t gid; | |
297 | mode_t mode; | |
227e8e86 | 298 | struct stat st; |
817175bc | 299 | |
300 | /* Determine the group to make the owner of the tty. */ | |
301 | grp = getgrnam("tty"); | |
302 | if (grp) { | |
303 | gid = grp->gr_gid; | |
304 | mode = S_IRUSR | S_IWUSR | S_IWGRP; | |
305 | } else { | |
306 | gid = pw->pw_gid; | |
307 | mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH; | |
308 | } | |
309 | ||
227e8e86 | 310 | /* |
311 | * Change owner and mode of the tty as required. | |
312 | * Warn but continue if filesystem is read-only and the uids match. | |
313 | */ | |
314 | if (stat(ttyname, &st)) | |
315 | fatal("stat(%.100s) failed: %.100s", ttyname, | |
316 | strerror(errno)); | |
317 | ||
318 | if (st.st_uid != pw->pw_uid || st.st_gid != gid) { | |
319 | if (chown(ttyname, pw->pw_uid, gid) < 0) { | |
320 | if (errno == EROFS && st.st_uid == pw->pw_uid) | |
321 | error("chown(%.100s, %d, %d) failed: %.100s", | |
2b87da3b | 322 | ttyname, pw->pw_uid, gid, |
227e8e86 | 323 | strerror(errno)); |
324 | else | |
325 | fatal("chown(%.100s, %d, %d) failed: %.100s", | |
2b87da3b | 326 | ttyname, pw->pw_uid, gid, |
227e8e86 | 327 | strerror(errno)); |
328 | } | |
329 | } | |
330 | ||
331 | if ((st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) != mode) { | |
332 | if (chmod(ttyname, mode) < 0) { | |
333 | if (errno == EROFS && | |
334 | (st.st_mode & (S_IRGRP | S_IROTH)) == 0) | |
335 | error("chmod(%.100s, 0%o) failed: %.100s", | |
336 | ttyname, mode, strerror(errno)); | |
337 | else | |
338 | fatal("chmod(%.100s, 0%o) failed: %.100s", | |
339 | ttyname, mode, strerror(errno)); | |
340 | } | |
341 | } | |
817175bc | 342 | } |