| 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 |
#if 0 /* not in BasiliskII */ |
| 15 |
#include "includes.h" |
| 16 |
RCSID("$OpenBSD: sshpty.c,v 1.4 2001/12/19 07:18:56 deraadt Exp $"); |
| 17 |
#else /* not in BasiliskII */ |
| 18 |
/* Selections from openssh's "includes.h" */ |
| 19 |
#include "config.h" |
| 20 |
|
| 21 |
#include <stdio.h> |
| 22 |
#include <ctype.h> |
| 23 |
#include <errno.h> |
| 24 |
#include <fcntl.h> /* For O_NONBLOCK */ |
| 25 |
#include <stdlib.h> |
| 26 |
#include <string.h> |
| 27 |
#include <pwd.h> |
| 28 |
|
| 29 |
#include <unistd.h> /* For STDIN_FILENO, etc */ |
| 30 |
#include <termios.h> /* Struct winsize */ |
| 31 |
|
| 32 |
/* |
| 33 |
*-*-nto-qnx needs these headers for strcasecmp and LASTLOG_FILE respectively |
| 34 |
*/ |
| 35 |
#ifdef HAVE_STRINGS_H |
| 36 |
# include <strings.h> |
| 37 |
#endif |
| 38 |
#ifdef HAVE_LOGIN_H |
| 39 |
# include <login.h> |
| 40 |
#endif |
| 41 |
|
| 42 |
#include <sys/ioctl.h> |
| 43 |
|
| 44 |
#ifdef HAVE_SYS_BSDTTY_H |
| 45 |
# include <sys/bsdtty.h> |
| 46 |
#endif |
| 47 |
|
| 48 |
#ifdef HAVE_SYS_STAT_H |
| 49 |
# include <sys/stat.h> /* For S_* constants and macros */ |
| 50 |
#endif |
| 51 |
|
| 52 |
#ifndef _PATH_TTY |
| 53 |
# define _PATH_TTY "/dev/tty" |
| 54 |
#endif |
| 55 |
|
| 56 |
#include "strlcpy.h" |
| 57 |
|
| 58 |
#define debug(x) ; |
| 59 |
|
| 60 |
#endif /* not in BasiliskII */ |
| 61 |
|
| 62 |
#ifdef HAVE_UTIL_H |
| 63 |
# include <util.h> |
| 64 |
#endif /* HAVE_UTIL_H */ |
| 65 |
|
| 66 |
#include "sshpty.h" |
| 67 |
#if 0 /* not in BasiliskII */ |
| 68 |
#include "log.h" |
| 69 |
#include "misc.h" |
| 70 |
#else /* stubs for BasiliskII */ |
| 71 |
#define log printf |
| 72 |
#define error printf |
| 73 |
#define fatal(x) {printf("Fatal error: %s", x); return 0} |
| 74 |
#endif /* not in BasiliskII */ |
| 75 |
|
| 76 |
/* Pty allocated with _getpty gets broken if we do I_PUSH:es to it. */ |
| 77 |
#if defined(HAVE__GETPTY) || defined(HAVE_OPENPTY) |
| 78 |
#undef HAVE_DEV_PTMX |
| 79 |
#endif |
| 80 |
|
| 81 |
#ifdef HAVE_PTY_H |
| 82 |
# include <pty.h> |
| 83 |
#endif |
| 84 |
#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H) |
| 85 |
# include <sys/stropts.h> |
| 86 |
#endif |
| 87 |
|
| 88 |
#ifndef O_NOCTTY |
| 89 |
#define O_NOCTTY 0 |
| 90 |
#endif |
| 91 |
|
| 92 |
/* |
| 93 |
* Allocates and opens a pty. Returns 0 if no pty could be allocated, or |
| 94 |
* nonzero if a pty was successfully allocated. On success, open file |
| 95 |
* descriptors for the pty and tty sides and the name of the tty side are |
| 96 |
* returned (the buffer must be able to hold at least 64 characters). |
| 97 |
*/ |
| 98 |
|
| 99 |
int |
| 100 |
pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, int namebuflen) |
| 101 |
{ |
| 102 |
#if defined(HAVE_OPENPTY) || defined(BSD4_4) |
| 103 |
/* openpty(3) exists in OSF/1 and some other os'es */ |
| 104 |
char *name; |
| 105 |
int i; |
| 106 |
|
| 107 |
i = openpty(ptyfd, ttyfd, NULL, NULL, NULL); |
| 108 |
if (i < 0) { |
| 109 |
error("openpty: %.100s", strerror(errno)); |
| 110 |
return 0; |
| 111 |
} |
| 112 |
name = ttyname(*ttyfd); |
| 113 |
if (!name) |
| 114 |
fatal("openpty returns device for which ttyname fails."); |
| 115 |
|
| 116 |
strlcpy(namebuf, name, namebuflen); /* possible truncation */ |
| 117 |
return 1; |
| 118 |
#else /* HAVE_OPENPTY */ |
| 119 |
#ifdef HAVE__GETPTY |
| 120 |
/* |
| 121 |
* _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more |
| 122 |
* pty's automagically when needed |
| 123 |
*/ |
| 124 |
char *slave; |
| 125 |
|
| 126 |
slave = _getpty(ptyfd, O_RDWR, 0622, 0); |
| 127 |
if (slave == NULL) { |
| 128 |
error("_getpty: %.100s", strerror(errno)); |
| 129 |
return 0; |
| 130 |
} |
| 131 |
strlcpy(namebuf, slave, namebuflen); |
| 132 |
/* Open the slave side. */ |
| 133 |
*ttyfd = open(namebuf, O_RDWR | O_NOCTTY); |
| 134 |
if (*ttyfd < 0) { |
| 135 |
error("%.200s: %.100s", namebuf, strerror(errno)); |
| 136 |
close(*ptyfd); |
| 137 |
return 0; |
| 138 |
} |
| 139 |
return 1; |
| 140 |
#else /* HAVE__GETPTY */ |
| 141 |
#if defined(HAVE_DEV_PTMX) |
| 142 |
/* |
| 143 |
* This code is used e.g. on Solaris 2.x. (Note that Solaris 2.3 |
| 144 |
* also has bsd-style ptys, but they simply do not work.) |
| 145 |
*/ |
| 146 |
int ptm; |
| 147 |
char *pts; |
| 148 |
mysig_t old_signal; |
| 149 |
|
| 150 |
ptm = open("/dev/ptmx", O_RDWR | O_NOCTTY); |
| 151 |
if (ptm < 0) { |
| 152 |
error("/dev/ptmx: %.100s", strerror(errno)); |
| 153 |
return 0; |
| 154 |
} |
| 155 |
old_signal = mysignal(SIGCHLD, SIG_DFL); |
| 156 |
if (grantpt(ptm) < 0) { |
| 157 |
error("grantpt: %.100s", strerror(errno)); |
| 158 |
return 0; |
| 159 |
} |
| 160 |
mysignal(SIGCHLD, old_signal); |
| 161 |
if (unlockpt(ptm) < 0) { |
| 162 |
error("unlockpt: %.100s", strerror(errno)); |
| 163 |
return 0; |
| 164 |
} |
| 165 |
pts = ptsname(ptm); |
| 166 |
if (pts == NULL) |
| 167 |
error("Slave pty side name could not be obtained."); |
| 168 |
strlcpy(namebuf, pts, namebuflen); |
| 169 |
*ptyfd = ptm; |
| 170 |
|
| 171 |
/* Open the slave side. */ |
| 172 |
*ttyfd = open(namebuf, O_RDWR | O_NOCTTY); |
| 173 |
if (*ttyfd < 0) { |
| 174 |
error("%.100s: %.100s", namebuf, strerror(errno)); |
| 175 |
close(*ptyfd); |
| 176 |
return 0; |
| 177 |
} |
| 178 |
#ifndef HAVE_CYGWIN |
| 179 |
/* |
| 180 |
* Push the appropriate streams modules, as described in Solaris pts(7). |
| 181 |
* HP-UX pts(7) doesn't have ttcompat module. |
| 182 |
*/ |
| 183 |
if (ioctl(*ttyfd, I_PUSH, "ptem") < 0) |
| 184 |
error("ioctl I_PUSH ptem: %.100s", strerror(errno)); |
| 185 |
if (ioctl(*ttyfd, I_PUSH, "ldterm") < 0) |
| 186 |
error("ioctl I_PUSH ldterm: %.100s", strerror(errno)); |
| 187 |
#ifndef __hpux |
| 188 |
if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0) |
| 189 |
error("ioctl I_PUSH ttcompat: %.100s", strerror(errno)); |
| 190 |
#endif |
| 191 |
#endif |
| 192 |
return 1; |
| 193 |
#else /* HAVE_DEV_PTMX */ |
| 194 |
#ifdef HAVE_DEV_PTS_AND_PTC |
| 195 |
/* AIX-style pty code. */ |
| 196 |
const char *name; |
| 197 |
|
| 198 |
*ptyfd = open("/dev/ptc", O_RDWR | O_NOCTTY); |
| 199 |
if (*ptyfd < 0) { |
| 200 |
error("Could not open /dev/ptc: %.100s", strerror(errno)); |
| 201 |
return 0; |
| 202 |
} |
| 203 |
name = ttyname(*ptyfd); |
| 204 |
if (!name) |
| 205 |
fatal("Open of /dev/ptc returns device for which ttyname fails."); |
| 206 |
strlcpy(namebuf, name, namebuflen); |
| 207 |
*ttyfd = open(name, O_RDWR | O_NOCTTY); |
| 208 |
if (*ttyfd < 0) { |
| 209 |
error("Could not open pty slave side %.100s: %.100s", |
| 210 |
name, strerror(errno)); |
| 211 |
close(*ptyfd); |
| 212 |
return 0; |
| 213 |
} |
| 214 |
return 1; |
| 215 |
#else /* HAVE_DEV_PTS_AND_PTC */ |
| 216 |
#ifdef _CRAY |
| 217 |
char buf[64]; |
| 218 |
int i; |
| 219 |
int highpty; |
| 220 |
|
| 221 |
#ifdef _SC_CRAY_NPTY |
| 222 |
highpty = sysconf(_SC_CRAY_NPTY); |
| 223 |
if (highpty == -1) |
| 224 |
highpty = 128; |
| 225 |
#else |
| 226 |
highpty = 128; |
| 227 |
#endif |
| 228 |
|
| 229 |
for (i = 0; i < highpty; i++) { |
| 230 |
snprintf(buf, sizeof(buf), "/dev/pty/%03d", i); |
| 231 |
*ptyfd = open(buf, O_RDWR|O_NOCTTY); |
| 232 |
if (*ptyfd < 0) |
| 233 |
continue; |
| 234 |
snprintf(namebuf, namebuflen, "/dev/ttyp%03d", i); |
| 235 |
/* Open the slave side. */ |
| 236 |
*ttyfd = open(namebuf, O_RDWR|O_NOCTTY); |
| 237 |
if (*ttyfd < 0) { |
| 238 |
error("%.100s: %.100s", namebuf, strerror(errno)); |
| 239 |
close(*ptyfd); |
| 240 |
return 0; |
| 241 |
} |
| 242 |
return 1; |
| 243 |
} |
| 244 |
return 0; |
| 245 |
#else |
| 246 |
/* BSD-style pty code. */ |
| 247 |
char buf[64]; |
| 248 |
int i; |
| 249 |
const char *ptymajors = "pqrstuvwxyzabcdefghijklmnoABCDEFGHIJKLMNOPQRSTUVWXYZ"; |
| 250 |
const char *ptyminors = "0123456789abcdef"; |
| 251 |
int num_minors = strlen(ptyminors); |
| 252 |
int num_ptys = strlen(ptymajors) * num_minors; |
| 253 |
struct termios tio; |
| 254 |
|
| 255 |
for (i = 0; i < num_ptys; i++) { |
| 256 |
snprintf(buf, sizeof buf, "/dev/pty%c%c", ptymajors[i / num_minors], |
| 257 |
ptyminors[i % num_minors]); |
| 258 |
snprintf(namebuf, namebuflen, "/dev/tty%c%c", |
| 259 |
ptymajors[i / num_minors], ptyminors[i % num_minors]); |
| 260 |
|
| 261 |
*ptyfd = open(buf, O_RDWR | O_NOCTTY); |
| 262 |
if (*ptyfd < 0) { |
| 263 |
/* Try SCO style naming */ |
| 264 |
snprintf(buf, sizeof buf, "/dev/ptyp%d", i); |
| 265 |
snprintf(namebuf, namebuflen, "/dev/ttyp%d", i); |
| 266 |
*ptyfd = open(buf, O_RDWR | O_NOCTTY); |
| 267 |
if (*ptyfd < 0) |
| 268 |
continue; |
| 269 |
} |
| 270 |
|
| 271 |
/* Open the slave side. */ |
| 272 |
*ttyfd = open(namebuf, O_RDWR | O_NOCTTY); |
| 273 |
if (*ttyfd < 0) { |
| 274 |
error("%.100s: %.100s", namebuf, strerror(errno)); |
| 275 |
close(*ptyfd); |
| 276 |
return 0; |
| 277 |
} |
| 278 |
/* set tty modes to a sane state for broken clients */ |
| 279 |
if (tcgetattr(*ptyfd, &tio) < 0) |
| 280 |
log("Getting tty modes for pty failed: %.100s", strerror(errno)); |
| 281 |
else { |
| 282 |
tio.c_lflag |= (ECHO | ISIG | ICANON); |
| 283 |
tio.c_oflag |= (OPOST | ONLCR); |
| 284 |
tio.c_iflag |= ICRNL; |
| 285 |
|
| 286 |
/* Set the new modes for the terminal. */ |
| 287 |
if (tcsetattr(*ptyfd, TCSANOW, &tio) < 0) |
| 288 |
log("Setting tty modes for pty failed: %.100s", strerror(errno)); |
| 289 |
} |
| 290 |
|
| 291 |
return 1; |
| 292 |
} |
| 293 |
return 0; |
| 294 |
#endif /* CRAY */ |
| 295 |
#endif /* HAVE_DEV_PTS_AND_PTC */ |
| 296 |
#endif /* HAVE_DEV_PTMX */ |
| 297 |
#endif /* HAVE__GETPTY */ |
| 298 |
#endif /* HAVE_OPENPTY */ |
| 299 |
} |
| 300 |
|
| 301 |
/* Releases the tty. Its ownership is returned to root, and permissions to 0666. */ |
| 302 |
|
| 303 |
void |
| 304 |
pty_release(const char *ttyname) |
| 305 |
{ |
| 306 |
if (chown(ttyname, (uid_t) 0, (gid_t) 0) < 0) |
| 307 |
error("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno)); |
| 308 |
if (chmod(ttyname, (mode_t) 0666) < 0) |
| 309 |
error("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno)); |
| 310 |
} |
| 311 |
|
| 312 |
/* Makes the tty the processes controlling tty and sets it to sane modes. */ |
| 313 |
|
| 314 |
void |
| 315 |
pty_make_controlling_tty(int *ttyfd, const char *ttyname) |
| 316 |
{ |
| 317 |
int fd; |
| 318 |
#ifdef USE_VHANGUP |
| 319 |
void *old; |
| 320 |
#endif /* USE_VHANGUP */ |
| 321 |
|
| 322 |
#ifdef _CRAY |
| 323 |
if (setsid() < 0) |
| 324 |
error("setsid: %.100s", strerror(errno)); |
| 325 |
|
| 326 |
fd = open(ttyname, O_RDWR|O_NOCTTY); |
| 327 |
if (fd != -1) { |
| 328 |
mysignal(SIGHUP, SIG_IGN); |
| 329 |
ioctl(fd, TCVHUP, (char *)NULL); |
| 330 |
mysignal(SIGHUP, SIG_DFL); |
| 331 |
setpgid(0, 0); |
| 332 |
close(fd); |
| 333 |
} else { |
| 334 |
error("Failed to disconnect from controlling tty."); |
| 335 |
} |
| 336 |
|
| 337 |
debug("Setting controlling tty using TCSETCTTY."); |
| 338 |
ioctl(*ttyfd, TCSETCTTY, NULL); |
| 339 |
fd = open("/dev/tty", O_RDWR); |
| 340 |
if (fd < 0) |
| 341 |
error("%.100s: %.100s", ttyname, strerror(errno)); |
| 342 |
close(*ttyfd); |
| 343 |
*ttyfd = fd; |
| 344 |
#else /* _CRAY */ |
| 345 |
|
| 346 |
/* First disconnect from the old controlling tty. */ |
| 347 |
#ifdef TIOCNOTTY |
| 348 |
fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); |
| 349 |
if (fd >= 0) { |
| 350 |
(void) ioctl(fd, TIOCNOTTY, NULL); |
| 351 |
close(fd); |
| 352 |
} |
| 353 |
#endif /* TIOCNOTTY */ |
| 354 |
if (setsid() < 0) |
| 355 |
error("setsid: %.100s", strerror(errno)); |
| 356 |
|
| 357 |
/* |
| 358 |
* Verify that we are successfully disconnected from the controlling |
| 359 |
* tty. |
| 360 |
*/ |
| 361 |
fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); |
| 362 |
if (fd >= 0) { |
| 363 |
error("Failed to disconnect from controlling tty."); |
| 364 |
close(fd); |
| 365 |
} |
| 366 |
/* Make it our controlling tty. */ |
| 367 |
#ifdef TIOCSCTTY |
| 368 |
debug("Setting controlling tty using TIOCSCTTY."); |
| 369 |
if (ioctl(*ttyfd, TIOCSCTTY, NULL) < 0) |
| 370 |
error("ioctl(TIOCSCTTY): %.100s", strerror(errno)); |
| 371 |
#endif /* TIOCSCTTY */ |
| 372 |
#ifdef HAVE_NEWS4 |
| 373 |
if (setpgrp(0,0) < 0) |
| 374 |
error("SETPGRP %s",strerror(errno)); |
| 375 |
#endif /* HAVE_NEWS4 */ |
| 376 |
#ifdef USE_VHANGUP |
| 377 |
old = mysignal(SIGHUP, SIG_IGN); |
| 378 |
vhangup(); |
| 379 |
mysignal(SIGHUP, old); |
| 380 |
#endif /* USE_VHANGUP */ |
| 381 |
fd = open(ttyname, O_RDWR); |
| 382 |
if (fd < 0) { |
| 383 |
error("%.100s: %.100s", ttyname, strerror(errno)); |
| 384 |
} else { |
| 385 |
#ifdef USE_VHANGUP |
| 386 |
close(*ttyfd); |
| 387 |
*ttyfd = fd; |
| 388 |
#else /* USE_VHANGUP */ |
| 389 |
close(fd); |
| 390 |
#endif /* USE_VHANGUP */ |
| 391 |
} |
| 392 |
/* Verify that we now have a controlling tty. */ |
| 393 |
fd = open(_PATH_TTY, O_WRONLY); |
| 394 |
if (fd < 0) |
| 395 |
error("open /dev/tty failed - could not set controlling tty: %.100s", |
| 396 |
strerror(errno)); |
| 397 |
else { |
| 398 |
close(fd); |
| 399 |
} |
| 400 |
#endif /* _CRAY */ |
| 401 |
} |
| 402 |
|
| 403 |
#if 0 /* not in BasiliskII */ |
| 404 |
/* Changes the window size associated with the pty. */ |
| 405 |
|
| 406 |
void |
| 407 |
pty_change_window_size(int ptyfd, int row, int col, |
| 408 |
int xpixel, int ypixel) |
| 409 |
{ |
| 410 |
struct winsize w; |
| 411 |
w.ws_row = row; |
| 412 |
w.ws_col = col; |
| 413 |
w.ws_xpixel = xpixel; |
| 414 |
w.ws_ypixel = ypixel; |
| 415 |
(void) ioctl(ptyfd, TIOCSWINSZ, &w); |
| 416 |
} |
| 417 |
|
| 418 |
void |
| 419 |
pty_setowner(struct passwd *pw, const char *ttyname) |
| 420 |
{ |
| 421 |
struct group *grp; |
| 422 |
gid_t gid; |
| 423 |
mode_t mode; |
| 424 |
struct stat st; |
| 425 |
|
| 426 |
/* Determine the group to make the owner of the tty. */ |
| 427 |
grp = getgrnam("tty"); |
| 428 |
if (grp) { |
| 429 |
gid = grp->gr_gid; |
| 430 |
mode = S_IRUSR | S_IWUSR | S_IWGRP; |
| 431 |
} else { |
| 432 |
gid = pw->pw_gid; |
| 433 |
mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH; |
| 434 |
} |
| 435 |
|
| 436 |
/* |
| 437 |
* Change owner and mode of the tty as required. |
| 438 |
* Warn but continue if filesystem is read-only and the uids match/ |
| 439 |
* tty is owned by root. |
| 440 |
*/ |
| 441 |
if (stat(ttyname, &st)) |
| 442 |
fatal("stat(%.100s) failed: %.100s", ttyname, |
| 443 |
strerror(errno)); |
| 444 |
|
| 445 |
if (st.st_uid != pw->pw_uid || st.st_gid != gid) { |
| 446 |
if (chown(ttyname, pw->pw_uid, gid) < 0) { |
| 447 |
if (errno == EROFS && |
| 448 |
(st.st_uid == pw->pw_uid || st.st_uid == 0)) |
| 449 |
error("chown(%.100s, %d, %d) failed: %.100s", |
| 450 |
ttyname, pw->pw_uid, gid, |
| 451 |
strerror(errno)); |
| 452 |
else |
| 453 |
fatal("chown(%.100s, %d, %d) failed: %.100s", |
| 454 |
ttyname, pw->pw_uid, gid, |
| 455 |
strerror(errno)); |
| 456 |
} |
| 457 |
} |
| 458 |
|
| 459 |
if ((st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) != mode) { |
| 460 |
if (chmod(ttyname, mode) < 0) { |
| 461 |
if (errno == EROFS && |
| 462 |
(st.st_mode & (S_IRGRP | S_IROTH)) == 0) |
| 463 |
error("chmod(%.100s, 0%o) failed: %.100s", |
| 464 |
ttyname, mode, strerror(errno)); |
| 465 |
else |
| 466 |
fatal("chmod(%.100s, 0%o) failed: %.100s", |
| 467 |
ttyname, mode, strerror(errno)); |
| 468 |
} |
| 469 |
} |
| 470 |
} |
| 471 |
#endif /* not in BasiliskII */ |
