openssh-portable/sshpty.c

419 lines
10 KiB
C
Raw Normal View History

1999-10-27 05:42:43 +02:00
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Allocating a pseudo-terminal, and making it the controlling tty.
*
- (djm) Merge OpenBSD changes: - markus@cvs.openbsd.org 2000/09/05 02:59:57 [session.c] print hostname (not hushlogin) - markus@cvs.openbsd.org 2000/09/05 13:18:48 [authfile.c ssh-add.c] enable ssh-add -d for DSA keys - markus@cvs.openbsd.org 2000/09/05 13:20:49 [sftp-server.c] cleanup - markus@cvs.openbsd.org 2000/09/06 03:46:41 [authfile.h] prototype - deraadt@cvs.openbsd.org 2000/09/07 14:27:56 [ALL] cleanup copyright notices on all files. I have attempted to be accurate with the details. everything is now under Tatu's licence (which I copied from his readme), and/or the core-sdi bsd-ish thing for deattack, or various openbsd developers under a 2-term bsd licence. We're not changing any rules, just being accurate. - markus@cvs.openbsd.org 2000/09/07 14:40:30 [channels.c channels.h clientloop.c serverloop.c ssh.c] cleanup window and packet sizes for ssh2 flow control; ok niels - markus@cvs.openbsd.org 2000/09/07 14:53:00 [scp.c] typo - markus@cvs.openbsd.org 2000/09/07 15:13:37 [auth-options.c auth-options.h auth-rh-rsa.c auth-rsa.c auth.c] [authfile.h canohost.c channels.h compat.c hostfile.h log.c match.h] [pty.c readconf.c] some more Copyright fixes - markus@cvs.openbsd.org 2000/09/08 03:02:51 [README.openssh2] bye bye - deraadt@cvs.openbsd.org 2000/09/11 18:38:33 [LICENCE cipher.c] a few more comments about it being ARC4 not RC4 - markus@cvs.openbsd.org 2000/09/12 14:53:11 [log-client.c log-server.c log.c ssh.1 ssh.c ssh.h sshd.8 sshd.c] multiple debug levels - markus@cvs.openbsd.org 2000/09/14 14:25:15 [clientloop.c] typo - deraadt@cvs.openbsd.org 2000/09/15 01:13:51 [ssh-agent.c] check return value for setenv(3) for failure, and deal appropriately
2000-09-16 04:29:08 +02:00
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
1999-10-27 05:42:43 +02:00
#include "includes.h"
RCSID("$OpenBSD: sshpty.c,v 1.4 2001/12/19 07:18:56 deraadt Exp $");
1999-12-14 00:54:47 +01:00
#ifdef HAVE_UTIL_H
# include <util.h>
#endif /* HAVE_UTIL_H */
#include "sshpty.h"
Hopefully things did not get mixed around too much. It compiles under Linux and works. So that is at least a good sign. =) 20010122 - (bal) OpenBSD Resync - markus@cvs.openbsd.org 2001/01/19 12:45:26 GMT 2001 by markus [servconf.c ssh.h sshd.c] only auth-chall.c needs #ifdef SKEY - markus@cvs.openbsd.org 2001/01/19 15:55:10 GMT 2001 by markus [auth-krb4.c auth-options.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth1.c auth2.c channels.c clientloop.c dh.c dispatch.c nchan.c packet.c pathname.h readconf.c scp.c servconf.c serverloop.c session.c ssh-add.c ssh-keygen.c ssh-keyscan.c ssh.c ssh.h ssh1.h sshconnect1.c sshd.c ttymodes.c] move ssh1 definitions to ssh1.h, pathnames to pathnames.h - markus@cvs.openbsd.org 2001/01/19 16:48:14 [sshd.8] fix typo; from stevesk@ - markus@cvs.openbsd.org 2001/01/19 16:50:58 [ssh-dss.c] clear and free digest, make consistent with other code (use dlen); from stevesk@ - markus@cvs.openbsd.org 2001/01/20 15:55:20 GMT 2001 by markus [auth-options.c auth-options.h auth-rsa.c auth2.c] pass the filename to auth_parse_options() - markus@cvs.openbsd.org 2001/01/20 17:59:40 GMT 2001 [readconf.c] fix SIGSEGV from -o ""; problem noted by jehsom@togetherweb.com - stevesk@cvs.openbsd.org 2001/01/20 18:20:29 [sshconnect2.c] dh_new_group() does not return NULL. ok markus@ - markus@cvs.openbsd.org 2001/01/20 21:33:42 [ssh-add.c] do not loop forever if askpass does not exist; from andrew@pimlott.ne.mediaone.net - djm@cvs.openbsd.org 2001/01/20 23:00:56 [servconf.c] Check for NULL return from strdelim; ok markus - djm@cvs.openbsd.org 2001/01/20 23:02:07 [readconf.c] KNF; ok markus - jakob@cvs.openbsd.org 2001/01/21 9:00:33 [ssh-keygen.1] remove -R flag; ok markus@ - markus@cvs.openbsd.org 2001/01/21 19:05:40 [atomicio.c automicio.h auth-chall.c auth-krb4.c auth-options.c auth-options.h auth-passwd.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth.c auth.h auth1.c auth2-chall.c auth2.c authfd.c authfile.c bufaux.c bufaux.h buffer.c canahost.c canahost.h channels.c cipher.c cli.c clientloop.c clientloop.h compat.c compress.c deattack.c dh.c dispatch.c groupaccess.c hmac.c hostfile.c kex.c key.c key.h log-client.c log-server.c log.c log.h login.c login.h match.c misc.c misc.h nchan.c packet.c pty.c radix.h readconf.c readpass.c readpass.h rsa.c scp.c servconf.c serverloop.c serverloop.h session.c sftp-server.c ssh-add.c ssh-agent.c ssh-dss.c ssh-keygen.c ssh-keyscan.c ssh-rsa.c ssh.c ssh.h sshconnect.c sshconnect.h sshconnect1.c sshconnect2.c sshd.c tildexpand.c tildexpand.h ttysmodes.c uidswap.c xmalloc.c] split ssh.h and try to cleanup the #include mess. remove unnecessary #includes. rename util.[ch] -> misc.[ch] - (bal) renamed 'PIDDIR' to '_PATH_SSH_PIDDIR' to match OpenBSD tree - (bal) Moved #ifdef KRB4 in auth-krb4.c above the #include to resolve conflict when compiling for non-kerb install - (bal) removed the #ifdef SKEY in auth1.c to match Markus' changes on 1/19.
2001-01-22 06:34:40 +01:00
#include "log.h"
#include "misc.h"
1999-10-27 05:42:43 +02:00
/* Pty allocated with _getpty gets broken if we do I_PUSH:es to it. */
#if defined(HAVE__GETPTY) || defined(HAVE_OPENPTY)
#undef HAVE_DEV_PTMX
#endif
#ifdef HAVE_PTY_H
# include <pty.h>
#endif
#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
# include <sys/stropts.h>
#endif
1999-10-27 05:42:43 +02:00
#ifndef O_NOCTTY
#define O_NOCTTY 0
#endif
/*
* Allocates and opens a pty. Returns 0 if no pty could be allocated, or
* nonzero if a pty was successfully allocated. On success, open file
* descriptors for the pty and tty sides and the name of the tty side are
* returned (the buffer must be able to hold at least 64 characters).
*/
1999-10-27 05:42:43 +02:00
int
pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, int namebuflen)
1999-10-27 05:42:43 +02:00
{
#if defined(HAVE_OPENPTY) || defined(BSD4_4)
/* openpty(3) exists in OSF/1 and some other os'es */
char *name;
int i;
1999-10-27 05:42:43 +02:00
i = openpty(ptyfd, ttyfd, NULL, NULL, NULL);
if (i < 0) {
error("openpty: %.100s", strerror(errno));
return 0;
}
name = ttyname(*ttyfd);
if (!name)
fatal("openpty returns device for which ttyname fails.");
strlcpy(namebuf, name, namebuflen); /* possible truncation */
return 1;
1999-10-27 05:42:43 +02:00
#else /* HAVE_OPENPTY */
#ifdef HAVE__GETPTY
/*
* _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more
* pty's automagically when needed
*/
char *slave;
slave = _getpty(ptyfd, O_RDWR, 0622, 0);
if (slave == NULL) {
error("_getpty: %.100s", strerror(errno));
return 0;
}
strlcpy(namebuf, slave, namebuflen);
/* Open the slave side. */
*ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
if (*ttyfd < 0) {
error("%.200s: %.100s", namebuf, strerror(errno));
close(*ptyfd);
return 0;
}
return 1;
1999-10-27 05:42:43 +02:00
#else /* HAVE__GETPTY */
#if defined(HAVE_DEV_PTMX)
/*
* This code is used e.g. on Solaris 2.x. (Note that Solaris 2.3
* also has bsd-style ptys, but they simply do not work.)
*/
int ptm;
char *pts;
mysig_t old_signal;
ptm = open("/dev/ptmx", O_RDWR | O_NOCTTY);
if (ptm < 0) {
error("/dev/ptmx: %.100s", strerror(errno));
return 0;
}
old_signal = mysignal(SIGCHLD, SIG_DFL);
if (grantpt(ptm) < 0) {
error("grantpt: %.100s", strerror(errno));
return 0;
}
mysignal(SIGCHLD, old_signal);
if (unlockpt(ptm) < 0) {
error("unlockpt: %.100s", strerror(errno));
return 0;
}
pts = ptsname(ptm);
if (pts == NULL)
error("Slave pty side name could not be obtained.");
strlcpy(namebuf, pts, namebuflen);
*ptyfd = ptm;
/* Open the slave side. */
*ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
if (*ttyfd < 0) {
error("%.100s: %.100s", namebuf, strerror(errno));
close(*ptyfd);
return 0;
}
#ifndef HAVE_CYGWIN
/*
* Push the appropriate streams modules, as described in Solaris pts(7).
* HP-UX pts(7) doesn't have ttcompat module.
*/
if (ioctl(*ttyfd, I_PUSH, "ptem") < 0)
error("ioctl I_PUSH ptem: %.100s", strerror(errno));
if (ioctl(*ttyfd, I_PUSH, "ldterm") < 0)
error("ioctl I_PUSH ldterm: %.100s", strerror(errno));
#ifndef __hpux
if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0)
error("ioctl I_PUSH ttcompat: %.100s", strerror(errno));
#endif
#endif
return 1;
1999-10-27 05:42:43 +02:00
#else /* HAVE_DEV_PTMX */
#ifdef HAVE_DEV_PTS_AND_PTC
/* AIX-style pty code. */
const char *name;
1999-10-27 05:42:43 +02:00
*ptyfd = open("/dev/ptc", O_RDWR | O_NOCTTY);
if (*ptyfd < 0) {
error("Could not open /dev/ptc: %.100s", strerror(errno));
return 0;
}
name = ttyname(*ptyfd);
if (!name)
fatal("Open of /dev/ptc returns device for which ttyname fails.");
strlcpy(namebuf, name, namebuflen);
*ttyfd = open(name, O_RDWR | O_NOCTTY);
if (*ttyfd < 0) {
error("Could not open pty slave side %.100s: %.100s",
name, strerror(errno));
close(*ptyfd);
return 0;
}
return 1;
1999-10-27 05:42:43 +02:00
#else /* HAVE_DEV_PTS_AND_PTC */
#ifdef _CRAY
char buf[64];
int i;
int highpty;
#ifdef _SC_CRAY_NPTY
highpty = sysconf(_SC_CRAY_NPTY);
if (highpty == -1)
highpty = 128;
#else
highpty = 128;
#endif
for (i = 0; i < highpty; i++) {
snprintf(buf, sizeof(buf), "/dev/pty/%03d", i);
*ptyfd = open(buf, O_RDWR|O_NOCTTY);
if (*ptyfd < 0)
continue;
snprintf(namebuf, namebuflen, "/dev/ttyp%03d", i);
/* Open the slave side. */
*ttyfd = open(namebuf, O_RDWR|O_NOCTTY);
if (*ttyfd < 0) {
error("%.100s: %.100s", namebuf, strerror(errno));
close(*ptyfd);
return 0;
}
return 1;
}
return 0;
#else
/* BSD-style pty code. */
char buf[64];
int i;
const char *ptymajors = "pqrstuvwxyzabcdefghijklmnoABCDEFGHIJKLMNOPQRSTUVWXYZ";
const char *ptyminors = "0123456789abcdef";
int num_minors = strlen(ptyminors);
int num_ptys = strlen(ptymajors) * num_minors;
struct termios tio;
for (i = 0; i < num_ptys; i++) {
snprintf(buf, sizeof buf, "/dev/pty%c%c", ptymajors[i / num_minors],
ptyminors[i % num_minors]);
snprintf(namebuf, namebuflen, "/dev/tty%c%c",
ptymajors[i / num_minors], ptyminors[i % num_minors]);
*ptyfd = open(buf, O_RDWR | O_NOCTTY);
if (*ptyfd < 0) {
/* Try SCO style naming */
snprintf(buf, sizeof buf, "/dev/ptyp%d", i);
snprintf(namebuf, namebuflen, "/dev/ttyp%d", i);
*ptyfd = open(buf, O_RDWR | O_NOCTTY);
if (*ptyfd < 0)
continue;
}
/* Open the slave side. */
*ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
if (*ttyfd < 0) {
error("%.100s: %.100s", namebuf, strerror(errno));
close(*ptyfd);
return 0;
}
/* set tty modes to a sane state for broken clients */
if (tcgetattr(*ptyfd, &tio) < 0)
log("Getting tty modes for pty failed: %.100s", strerror(errno));
else {
tio.c_lflag |= (ECHO | ISIG | ICANON);
tio.c_oflag |= (OPOST | ONLCR);
tio.c_iflag |= ICRNL;
/* Set the new modes for the terminal. */
if (tcsetattr(*ptyfd, TCSANOW, &tio) < 0)
log("Setting tty modes for pty failed: %.100s", strerror(errno));
}
return 1;
1999-10-27 05:42:43 +02:00
}
return 0;
#endif /* CRAY */
1999-10-27 05:42:43 +02:00
#endif /* HAVE_DEV_PTS_AND_PTC */
#endif /* HAVE_DEV_PTMX */
#endif /* HAVE__GETPTY */
#endif /* HAVE_OPENPTY */
}
/* Releases the tty. Its ownership is returned to root, and permissions to 0666. */
1999-10-27 05:42:43 +02:00
void
pty_release(const char *ttyname)
1999-10-27 05:42:43 +02:00
{
if (chown(ttyname, (uid_t) 0, (gid_t) 0) < 0)
error("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno));
if (chmod(ttyname, (mode_t) 0666) < 0)
error("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno));
1999-10-27 05:42:43 +02:00
}
/* Makes the tty the processes controlling tty and sets it to sane modes. */
void
pty_make_controlling_tty(int *ttyfd, const char *ttyname)
1999-10-27 05:42:43 +02:00
{
int fd;
2001-10-12 11:15:48 +02:00
#ifdef USE_VHANGUP
void *old;
#endif /* USE_VHANGUP */
2001-10-12 11:15:48 +02:00
#ifdef _CRAY
if (setsid() < 0)
error("setsid: %.100s", strerror(errno));
fd = open(ttyname, O_RDWR|O_NOCTTY);
if (fd != -1) {
2001-10-12 11:15:48 +02:00
mysignal(SIGHUP, SIG_IGN);
ioctl(fd, TCVHUP, (char *)NULL);
2001-10-12 11:15:48 +02:00
mysignal(SIGHUP, SIG_DFL);
setpgid(0, 0);
close(fd);
} else {
error("Failed to disconnect from controlling tty.");
}
debug("Setting controlling tty using TCSETCTTY.");
ioctl(*ttyfd, TCSETCTTY, NULL);
fd = open("/dev/tty", O_RDWR);
if (fd < 0)
error("%.100s: %.100s", ttyname, strerror(errno));
close(*ttyfd);
*ttyfd = fd;
2001-10-12 11:15:48 +02:00
#else /* _CRAY */
1999-10-27 05:42:43 +02:00
/* First disconnect from the old controlling tty. */
1999-10-27 05:42:43 +02:00
#ifdef TIOCNOTTY
fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
if (fd >= 0) {
(void) ioctl(fd, TIOCNOTTY, NULL);
close(fd);
}
1999-10-27 05:42:43 +02:00
#endif /* TIOCNOTTY */
if (setsid() < 0)
error("setsid: %.100s", strerror(errno));
/*
* Verify that we are successfully disconnected from the controlling
* tty.
*/
fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
if (fd >= 0) {
error("Failed to disconnect from controlling tty.");
close(fd);
}
/* Make it our controlling tty. */
1999-10-27 05:42:43 +02:00
#ifdef TIOCSCTTY
debug("Setting controlling tty using TIOCSCTTY.");
if (ioctl(*ttyfd, TIOCSCTTY, NULL) < 0)
error("ioctl(TIOCSCTTY): %.100s", strerror(errno));
1999-10-27 05:42:43 +02:00
#endif /* TIOCSCTTY */
#ifdef HAVE_NEWS4
if (setpgrp(0,0) < 0)
error("SETPGRP %s",strerror(errno));
#endif /* HAVE_NEWS4 */
#ifdef USE_VHANGUP
2001-10-12 11:15:48 +02:00
old = mysignal(SIGHUP, SIG_IGN);
vhangup();
2001-10-12 11:15:48 +02:00
mysignal(SIGHUP, old);
#endif /* USE_VHANGUP */
fd = open(ttyname, O_RDWR);
if (fd < 0) {
error("%.100s: %.100s", ttyname, strerror(errno));
} else {
#ifdef USE_VHANGUP
close(*ttyfd);
*ttyfd = fd;
#else /* USE_VHANGUP */
close(fd);
#endif /* USE_VHANGUP */
}
/* Verify that we now have a controlling tty. */
fd = open(_PATH_TTY, O_WRONLY);
if (fd < 0)
error("open /dev/tty failed - could not set controlling tty: %.100s",
strerror(errno));
else {
close(fd);
}
2001-10-12 11:15:48 +02:00
#endif /* _CRAY */
1999-10-27 05:42:43 +02:00
}
/* Changes the window size associated with the pty. */
void
pty_change_window_size(int ptyfd, int row, int col,
int xpixel, int ypixel)
1999-10-27 05:42:43 +02:00
{
struct winsize w;
w.ws_row = row;
w.ws_col = col;
w.ws_xpixel = xpixel;
w.ws_ypixel = ypixel;
(void) ioctl(ptyfd, TIOCSWINSZ, &w);
1999-10-27 05:42:43 +02:00
}
void
pty_setowner(struct passwd *pw, const char *ttyname)
{
struct group *grp;
gid_t gid;
mode_t mode;
struct stat st;
/* Determine the group to make the owner of the tty. */
grp = getgrnam("tty");
if (grp) {
gid = grp->gr_gid;
mode = S_IRUSR | S_IWUSR | S_IWGRP;
} else {
gid = pw->pw_gid;
mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH;
}
/*
* Change owner and mode of the tty as required.
* Warn but continue if filesystem is read-only and the uids match/
* tty is owned by root.
*/
if (stat(ttyname, &st))
fatal("stat(%.100s) failed: %.100s", ttyname,
strerror(errno));
if (st.st_uid != pw->pw_uid || st.st_gid != gid) {
if (chown(ttyname, pw->pw_uid, gid) < 0) {
if (errno == EROFS &&
(st.st_uid == pw->pw_uid || st.st_uid == 0))
error("chown(%.100s, %d, %d) failed: %.100s",
ttyname, pw->pw_uid, gid,
strerror(errno));
else
fatal("chown(%.100s, %d, %d) failed: %.100s",
ttyname, pw->pw_uid, gid,
strerror(errno));
}
}
if ((st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) != mode) {
if (chmod(ttyname, mode) < 0) {
if (errno == EROFS &&
(st.st_mode & (S_IRGRP | S_IROTH)) == 0)
error("chmod(%.100s, 0%o) failed: %.100s",
ttyname, mode, strerror(errno));
else
fatal("chmod(%.100s, 0%o) failed: %.100s",
ttyname, mode, strerror(errno));
}
}
}