]>
Commit | Line | Data |
---|---|---|
1 | /* | |
2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
4 | * All rights reserved | |
5 | * Allocating a pseudo-terminal, and making it the controlling tty. | |
6 | * | |
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". | |
12 | */ | |
13 | ||
14 | #include "includes.h" | |
15 | RCSID("$OpenBSD: pty.c,v 1.22 2001/02/08 19:30:52 itojun Exp $"); | |
16 | ||
17 | #ifdef HAVE_UTIL_H | |
18 | # include <util.h> | |
19 | #endif /* HAVE_UTIL_H */ | |
20 | ||
21 | #include "pty.h" | |
22 | #include "log.h" | |
23 | ||
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 | ||
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 | ||
36 | #ifndef O_NOCTTY | |
37 | #define O_NOCTTY 0 | |
38 | #endif | |
39 | ||
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 | */ | |
46 | ||
47 | int | |
48 | pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, int namebuflen) | |
49 | { | |
50 | #if defined(HAVE_OPENPTY) || defined(BSD4_4) | |
51 | /* openpty(3) exists in OSF/1 and some other os'es */ | |
52 | char buf[64]; | |
53 | int i; | |
54 | ||
55 | i = openpty(ptyfd, ttyfd, buf, NULL, NULL); | |
56 | if (i < 0) { | |
57 | error("openpty: %.100s", strerror(errno)); | |
58 | return 0; | |
59 | } | |
60 | strlcpy(namebuf, buf, namebuflen); /* possible truncation */ | |
61 | return 1; | |
62 | #else /* HAVE_OPENPTY */ | |
63 | #ifdef HAVE__GETPTY | |
64 | /* | |
65 | * _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more | |
66 | * pty's automagically when needed | |
67 | */ | |
68 | char *slave; | |
69 | ||
70 | slave = _getpty(ptyfd, O_RDWR, 0622, 0); | |
71 | if (slave == NULL) { | |
72 | error("_getpty: %.100s", strerror(errno)); | |
73 | return 0; | |
74 | } | |
75 | strlcpy(namebuf, slave, namebuflen); | |
76 | /* Open the slave side. */ | |
77 | *ttyfd = open(namebuf, O_RDWR | O_NOCTTY); | |
78 | if (*ttyfd < 0) { | |
79 | error("%.200s: %.100s", namebuf, strerror(errno)); | |
80 | close(*ptyfd); | |
81 | return 0; | |
82 | } | |
83 | return 1; | |
84 | #else /* HAVE__GETPTY */ | |
85 | #if defined(HAVE_DEV_PTMX) | |
86 | /* | |
87 | * This code is used e.g. on Solaris 2.x. (Note that Solaris 2.3 | |
88 | * also has bsd-style ptys, but they simply do not work.) | |
89 | */ | |
90 | int ptm; | |
91 | char *pts; | |
92 | ||
93 | ptm = open("/dev/ptmx", O_RDWR | O_NOCTTY); | |
94 | if (ptm < 0) { | |
95 | error("/dev/ptmx: %.100s", strerror(errno)); | |
96 | return 0; | |
97 | } | |
98 | if (grantpt(ptm) < 0) { | |
99 | error("grantpt: %.100s", strerror(errno)); | |
100 | return 0; | |
101 | } | |
102 | if (unlockpt(ptm) < 0) { | |
103 | error("unlockpt: %.100s", strerror(errno)); | |
104 | return 0; | |
105 | } | |
106 | pts = ptsname(ptm); | |
107 | if (pts == NULL) | |
108 | error("Slave pty side name could not be obtained."); | |
109 | strlcpy(namebuf, pts, namebuflen); | |
110 | *ptyfd = ptm; | |
111 | ||
112 | /* Open the slave side. */ | |
113 | *ttyfd = open(namebuf, O_RDWR | O_NOCTTY); | |
114 | if (*ttyfd < 0) { | |
115 | error("%.100s: %.100s", namebuf, strerror(errno)); | |
116 | close(*ptyfd); | |
117 | return 0; | |
118 | } | |
119 | #ifndef HAVE_CYGWIN | |
120 | /* | |
121 | * Push the appropriate streams modules, as described in Solaris pts(7). | |
122 | * HP-UX pts(7) doesn't have ttcompat module. | |
123 | */ | |
124 | if (ioctl(*ttyfd, I_PUSH, "ptem") < 0) | |
125 | error("ioctl I_PUSH ptem: %.100s", strerror(errno)); | |
126 | if (ioctl(*ttyfd, I_PUSH, "ldterm") < 0) | |
127 | error("ioctl I_PUSH ldterm: %.100s", strerror(errno)); | |
128 | #ifndef __hpux | |
129 | if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0) | |
130 | error("ioctl I_PUSH ttcompat: %.100s", strerror(errno)); | |
131 | #endif | |
132 | #endif | |
133 | return 1; | |
134 | #else /* HAVE_DEV_PTMX */ | |
135 | #ifdef HAVE_DEV_PTS_AND_PTC | |
136 | /* AIX-style pty code. */ | |
137 | const char *name; | |
138 | ||
139 | *ptyfd = open("/dev/ptc", O_RDWR | O_NOCTTY); | |
140 | if (*ptyfd < 0) { | |
141 | error("Could not open /dev/ptc: %.100s", strerror(errno)); | |
142 | return 0; | |
143 | } | |
144 | name = ttyname(*ptyfd); | |
145 | if (!name) | |
146 | fatal("Open of /dev/ptc returns device for which ttyname fails."); | |
147 | strlcpy(namebuf, name, namebuflen); | |
148 | *ttyfd = open(name, O_RDWR | O_NOCTTY); | |
149 | if (*ttyfd < 0) { | |
150 | error("Could not open pty slave side %.100s: %.100s", | |
151 | name, strerror(errno)); | |
152 | close(*ptyfd); | |
153 | return 0; | |
154 | } | |
155 | return 1; | |
156 | #else /* HAVE_DEV_PTS_AND_PTC */ | |
157 | /* BSD-style pty code. */ | |
158 | char buf[64]; | |
159 | int i; | |
160 | const char *ptymajors = "pqrstuvwxyzabcdefghijklmnoABCDEFGHIJKLMNOPQRSTUVWXYZ"; | |
161 | const char *ptyminors = "0123456789abcdef"; | |
162 | int num_minors = strlen(ptyminors); | |
163 | int num_ptys = strlen(ptymajors) * num_minors; | |
164 | ||
165 | for (i = 0; i < num_ptys; i++) { | |
166 | snprintf(buf, sizeof buf, "/dev/pty%c%c", ptymajors[i / num_minors], | |
167 | ptyminors[i % num_minors]); | |
168 | snprintf(namebuf, namebuflen, "/dev/tty%c%c", | |
169 | ptymajors[i / num_minors], ptyminors[i % num_minors]); | |
170 | ||
171 | *ptyfd = open(buf, O_RDWR | O_NOCTTY); | |
172 | if (*ptyfd < 0) { | |
173 | /* Try SCO style naming */ | |
174 | snprintf(buf, sizeof buf, "/dev/ptyp%d", i); | |
175 | snprintf(namebuf, namebuflen, "/dev/ttyp%d", i); | |
176 | *ptyfd = open(buf, O_RDWR | O_NOCTTY); | |
177 | if (*ptyfd < 0) | |
178 | continue; | |
179 | } | |
180 | ||
181 | /* Open the slave side. */ | |
182 | *ttyfd = open(namebuf, O_RDWR | O_NOCTTY); | |
183 | if (*ttyfd < 0) { | |
184 | error("%.100s: %.100s", namebuf, strerror(errno)); | |
185 | close(*ptyfd); | |
186 | return 0; | |
187 | } | |
188 | return 1; | |
189 | } | |
190 | return 0; | |
191 | #endif /* HAVE_DEV_PTS_AND_PTC */ | |
192 | #endif /* HAVE_DEV_PTMX */ | |
193 | #endif /* HAVE__GETPTY */ | |
194 | #endif /* HAVE_OPENPTY */ | |
195 | } | |
196 | ||
197 | /* Releases the tty. Its ownership is returned to root, and permissions to 0666. */ | |
198 | ||
199 | void | |
200 | pty_release(const char *ttyname) | |
201 | { | |
202 | if (chown(ttyname, (uid_t) 0, (gid_t) 0) < 0) | |
203 | error("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno)); | |
204 | if (chmod(ttyname, (mode_t) 0666) < 0) | |
205 | error("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno)); | |
206 | } | |
207 | ||
208 | /* Makes the tty the processes controlling tty and sets it to sane modes. */ | |
209 | ||
210 | void | |
211 | pty_make_controlling_tty(int *ttyfd, const char *ttyname) | |
212 | { | |
213 | int fd; | |
214 | #ifdef USE_VHANGUP | |
215 | void *old; | |
216 | #endif /* USE_VHANGUP */ | |
217 | ||
218 | /* First disconnect from the old controlling tty. */ | |
219 | #ifdef TIOCNOTTY | |
220 | fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); | |
221 | if (fd >= 0) { | |
222 | (void) ioctl(fd, TIOCNOTTY, NULL); | |
223 | close(fd); | |
224 | } | |
225 | #endif /* TIOCNOTTY */ | |
226 | if (setsid() < 0) | |
227 | error("setsid: %.100s", strerror(errno)); | |
228 | ||
229 | /* | |
230 | * Verify that we are successfully disconnected from the controlling | |
231 | * tty. | |
232 | */ | |
233 | fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); | |
234 | if (fd >= 0) { | |
235 | error("Failed to disconnect from controlling tty."); | |
236 | close(fd); | |
237 | } | |
238 | /* Make it our controlling tty. */ | |
239 | #ifdef TIOCSCTTY | |
240 | debug("Setting controlling tty using TIOCSCTTY."); | |
241 | if (ioctl(*ttyfd, TIOCSCTTY, NULL) < 0) | |
242 | error("ioctl(TIOCSCTTY): %.100s", strerror(errno)); | |
243 | #endif /* TIOCSCTTY */ | |
244 | #ifdef HAVE_NEWS4 | |
245 | if (setpgrp(0,0) < 0) | |
246 | error("SETPGRP %s",strerror(errno)); | |
247 | #endif /* HAVE_NEWS4 */ | |
248 | #ifdef USE_VHANGUP | |
249 | old = signal(SIGHUP, SIG_IGN); | |
250 | vhangup(); | |
251 | signal(SIGHUP, old); | |
252 | #endif /* USE_VHANGUP */ | |
253 | fd = open(ttyname, O_RDWR); | |
254 | if (fd < 0) { | |
255 | error("%.100s: %.100s", ttyname, strerror(errno)); | |
256 | } else { | |
257 | #ifdef USE_VHANGUP | |
258 | close(*ttyfd); | |
259 | *ttyfd = fd; | |
260 | #else /* USE_VHANGUP */ | |
261 | close(fd); | |
262 | #endif /* USE_VHANGUP */ | |
263 | } | |
264 | /* Verify that we now have a controlling tty. */ | |
265 | fd = open(_PATH_TTY, O_WRONLY); | |
266 | if (fd < 0) | |
267 | error("open /dev/tty failed - could not set controlling tty: %.100s", | |
268 | strerror(errno)); | |
269 | else { | |
270 | close(fd); | |
271 | } | |
272 | } | |
273 | ||
274 | /* Changes the window size associated with the pty. */ | |
275 | ||
276 | void | |
277 | pty_change_window_size(int ptyfd, int row, int col, | |
278 | int xpixel, int ypixel) | |
279 | { | |
280 | struct winsize w; | |
281 | w.ws_row = row; | |
282 | w.ws_col = col; | |
283 | w.ws_xpixel = xpixel; | |
284 | w.ws_ypixel = ypixel; | |
285 | (void) ioctl(ptyfd, TIOCSWINSZ, &w); | |
286 | } | |
287 | ||
288 | void | |
289 | pty_setowner(struct passwd *pw, const char *ttyname) | |
290 | { | |
291 | struct group *grp; | |
292 | gid_t gid; | |
293 | mode_t mode; | |
294 | struct stat st; | |
295 | ||
296 | /* Determine the group to make the owner of the tty. */ | |
297 | grp = getgrnam("tty"); | |
298 | if (grp) { | |
299 | gid = grp->gr_gid; | |
300 | mode = S_IRUSR | S_IWUSR | S_IWGRP; | |
301 | } else { | |
302 | gid = pw->pw_gid; | |
303 | mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH; | |
304 | } | |
305 | ||
306 | /* | |
307 | * Change owner and mode of the tty as required. | |
308 | * Warn but continue if filesystem is read-only and the uids match. | |
309 | */ | |
310 | if (stat(ttyname, &st)) | |
311 | fatal("stat(%.100s) failed: %.100s", ttyname, | |
312 | strerror(errno)); | |
313 | ||
314 | if (st.st_uid != pw->pw_uid || st.st_gid != gid) { | |
315 | if (chown(ttyname, pw->pw_uid, gid) < 0) { | |
316 | if (errno == EROFS && st.st_uid == pw->pw_uid) | |
317 | error("chown(%.100s, %d, %d) failed: %.100s", | |
318 | ttyname, pw->pw_uid, gid, | |
319 | strerror(errno)); | |
320 | else | |
321 | fatal("chown(%.100s, %d, %d) failed: %.100s", | |
322 | ttyname, pw->pw_uid, gid, | |
323 | strerror(errno)); | |
324 | } | |
325 | } | |
326 | ||
327 | if ((st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) != mode) { | |
328 | if (chmod(ttyname, mode) < 0) { | |
329 | if (errno == EROFS && | |
330 | (st.st_mode & (S_IRGRP | S_IROTH)) == 0) | |
331 | error("chmod(%.100s, 0%o) failed: %.100s", | |
332 | ttyname, mode, strerror(errno)); | |
333 | else | |
334 | fatal("chmod(%.100s, 0%o) failed: %.100s", | |
335 | ttyname, mode, strerror(errno)); | |
336 | } | |
337 | } | |
338 | } |