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authorMatt Johnston <matt@ucc.asn.au>2004-06-01 02:46:09 +0000
committerMatt Johnston <matt@ucc.asn.au>2004-06-01 02:46:09 +0000
commitd53c6e53ee09a98198f57c5dfa18416040d3ce99 (patch)
tree3b5a173c356f867b94df3873b57ff36d33129ea7 /sshpty.c
downloaddropbear-d53c6e53ee09a98198f57c5dfa18416040d3ce99.tar.gz
Makefile.in contains updated files required
Diffstat (limited to 'sshpty.c')
-rw-r--r--sshpty.c412
1 files changed, 412 insertions, 0 deletions
diff --git a/sshpty.c b/sshpty.c
new file mode 100644
index 0000000..799a92c
--- /dev/null
+++ b/sshpty.c
@@ -0,0 +1,412 @@
+/*
+ * Dropbear - a SSH2 server
+ *
+ * Copied from OpenSSH-3.5p1 source, modified by Matt Johnston 2003
+ *
+ * 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.
+ *
+ * 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".
+ */
+
+/*RCSID("$OpenBSD: sshpty.c,v 1.7 2002/06/24 17:57:20 deraadt Exp $");*/
+
+#include "includes.h"
+#include "dbutil.h"
+#include "errno.h"
+#include "sshpty.h"
+
+/* 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(USE_DEV_PTMX) && defined(HAVE_STROPTS_H)
+# include <stropts.h>
+#endif
+
+#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).
+ */
+
+int
+pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, int namebuflen)
+{
+#if defined(HAVE_OPENPTY)
+ /* exists in recent (4.4) BSDs and OSF/1 */
+ char *name;
+ int i;
+
+ i = openpty(ptyfd, ttyfd, NULL, NULL, NULL);
+ if (i < 0) {
+ dropbear_log(LOG_WARNING,
+ "pty_allocate: openpty: %.100s", strerror(errno));
+ return 0;
+ }
+ name = ttyname(*ttyfd);
+ if (!name) {
+ dropbear_exit("ttyname fails for openpty device");
+ }
+
+ strlcpy(namebuf, name, namebuflen); /* possible truncation */
+ return 1;
+#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) {
+ dropbear_log(LOG_WARNING,
+ "pty_allocate: _getpty: %.100s", strerror(errno));
+ return 0;
+ }
+ strlcpy(namebuf, slave, namebuflen);
+ /* Open the slave side. */
+ *ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
+ if (*ttyfd < 0) {
+ dropbear_log(LOG_WARNING,
+ "pty_allocate error: ttyftd open error");
+ close(*ptyfd);
+ return 0;
+ }
+ return 1;
+#else /* HAVE__GETPTY */
+#if defined(USE_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.)
+ *
+ * Linux systems may have the /dev/ptmx device, but this code won't work.
+ */
+ int ptm;
+ char *pts;
+
+ ptm = open("/dev/ptmx", O_RDWR | O_NOCTTY);
+ if (ptm < 0) {
+ dropbear_log(LOG_WARNING,
+ "pty_allocate: /dev/ptmx: %.100s", strerror(errno));
+ return 0;
+ }
+ if (grantpt(ptm) < 0) {
+ dropbear_log(LOG_WARNING,
+ "grantpt: %.100s", strerror(errno));
+ return 0;
+ }
+ if (unlockpt(ptm) < 0) {
+ dropbear_log(LOG_WARNING,
+ "unlockpt: %.100s", strerror(errno));
+ return 0;
+ }
+ pts = ptsname(ptm);
+ if (pts == NULL) {
+ dropbear_log(LOG_WARNING,
+ "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) {
+ dropbear_log(LOG_ERR,
+ "error opening pts %.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) {
+ dropbear_log(LOG_WARNING,
+ "ioctl I_PUSH ptem: %.100s", strerror(errno));
+ }
+ if (ioctl(*ttyfd, I_PUSH, "ldterm") < 0) {
+ dropbear_log(LOG_WARNING,
+ "ioctl I_PUSH ldterm: %.100s", strerror(errno));
+ }
+#ifndef __hpux
+ if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0) {
+ dropbear_log(LOG_WARNING,
+ "ioctl I_PUSH ttcompat: %.100s", strerror(errno));
+ }
+#endif
+#endif
+ return 1;
+#else /* USE_DEV_PTMX */
+#ifdef HAVE_DEV_PTS_AND_PTC
+ /* AIX-style pty code. */
+ const char *name;
+
+ *ptyfd = open("/dev/ptc", O_RDWR | O_NOCTTY);
+ if (*ptyfd < 0) {
+ dropbear_log(LOG_ERR,
+ "Could not open /dev/ptc: %.100s", strerror(errno));
+ return 0;
+ }
+ name = ttyname(*ptyfd);
+ if (!name) {
+ dropbear_exit("ttyname fails for /dev/ptc device");
+ }
+ strlcpy(namebuf, name, namebuflen);
+ *ttyfd = open(name, O_RDWR | O_NOCTTY);
+ if (*ttyfd < 0) {
+ dropbear_log(LOG_ERR,
+ "Could not open pty slave side %.100s: %.100s",
+ name, strerror(errno));
+ close(*ptyfd);
+ return 0;
+ }
+ return 1;
+#else /* HAVE_DEV_PTS_AND_PTC */
+
+ /* 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) {
+ dropbear_log(LOG_ERR,
+ "pty_allocate: %.100s: %.100s", namebuf, strerror(errno));
+ close(*ptyfd);
+ return 0;
+ }
+ /* set tty modes to a sane state for broken clients */
+ if (tcgetattr(*ptyfd, &tio) < 0) {
+ dropbear_log(LOG_WARNING,
+ "ptyallocate: tty modes 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) {
+ dropbear_log(LOG_WARNING,
+ "Setting tty modes for pty failed: %.100s",
+ strerror(errno));
+ }
+ }
+
+ return 1;
+ }
+ dropbear_log(LOG_WARNING, "failed to open any /dev/pty?? devices");
+ return 0;
+#endif /* HAVE_DEV_PTS_AND_PTC */
+#endif /* USE_DEV_PTMX */
+#endif /* HAVE__GETPTY */
+#endif /* HAVE_OPENPTY */
+}
+
+/* Releases the tty. Its ownership is returned to root, and permissions to 0666. */
+
+void
+pty_release(const char *tty_name)
+{
+ if (chown(tty_name, (uid_t) 0, (gid_t) 0) < 0
+ && (errno != ENOENT)) {
+ dropbear_log(LOG_ERR,
+ "chown %.100s 0 0 failed: %.100s", tty_name, strerror(errno));
+ }
+ if (chmod(tty_name, (mode_t) 0666) < 0
+ && (errno != ENOENT)) {
+ dropbear_log(LOG_ERR,
+ "chmod %.100s 0666 failed: %.100s", tty_name, strerror(errno));
+ }
+}
+
+/* Makes the tty the processes controlling tty and sets it to sane modes. */
+
+void
+pty_make_controlling_tty(int *ttyfd, const char *tty_name)
+{
+ int fd;
+#ifdef USE_VHANGUP
+ void *old;
+#endif /* USE_VHANGUP */
+
+ /* Solaris has a problem with TIOCNOTTY for a bg process, so
+ * we disable the signal which would STOP the process - matt */
+ signal(SIGTTOU, SIG_IGN);
+
+ /* First disconnect from the old controlling tty. */
+#ifdef TIOCNOTTY
+ fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
+ if (fd >= 0) {
+ (void) ioctl(fd, TIOCNOTTY, NULL);
+ close(fd);
+ }
+#endif /* TIOCNOTTY */
+ if (setsid() < 0) {
+ dropbear_log(LOG_ERR,
+ "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) {
+ dropbear_log(LOG_ERR,
+ "Failed to disconnect from controlling tty.\n");
+ close(fd);
+ }
+ /* Make it our controlling tty. */
+#ifdef TIOCSCTTY
+ if (ioctl(*ttyfd, TIOCSCTTY, NULL) < 0) {
+ dropbear_log(LOG_ERR,
+ "ioctl(TIOCSCTTY): %.100s", strerror(errno));
+ }
+#endif /* TIOCSCTTY */
+#ifdef HAVE_NEWS4
+ if (setpgrp(0,0) < 0) {
+ dropbear_log(LOG_ERR,
+ error("SETPGRP %s",strerror(errno)));
+ }
+#endif /* HAVE_NEWS4 */
+#ifdef USE_VHANGUP
+ old = mysignal(SIGHUP, SIG_IGN);
+ vhangup();
+ mysignal(SIGHUP, old);
+#endif /* USE_VHANGUP */
+ fd = open(tty_name, O_RDWR);
+ if (fd < 0) {
+ dropbear_log(LOG_ERR,
+ "%.100s: %.100s", tty_name, 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) {
+ dropbear_log(LOG_ERR,
+ "open /dev/tty failed - could not set controlling tty: %.100s",
+ strerror(errno));
+ } else {
+ close(fd);
+ }
+}
+
+/* Changes the window size associated with the pty. */
+
+void
+pty_change_window_size(int ptyfd, int row, int col,
+ int xpixel, int ypixel)
+{
+ struct winsize w;
+
+ w.ws_row = row;
+ w.ws_col = col;
+ w.ws_xpixel = xpixel;
+ w.ws_ypixel = ypixel;
+ (void) ioctl(ptyfd, TIOCSWINSZ, &w);
+}
+
+void
+pty_setowner(struct passwd *pw, const char *tty_name)
+{
+ 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(tty_name, &st)) {
+ dropbear_exit("pty_setowner: stat(%.101s) failed: %.100s",
+ tty_name, strerror(errno));
+ }
+
+ if (st.st_uid != pw->pw_uid || st.st_gid != gid) {
+ if (chown(tty_name, pw->pw_uid, gid) < 0) {
+ if (errno == EROFS &&
+ (st.st_uid == pw->pw_uid || st.st_uid == 0)) {
+ dropbear_log(LOG_ERR,
+ "chown(%.100s, %u, %u) failed: %.100s",
+ tty_name, (unsigned int)pw->pw_uid, (unsigned int)gid,
+ strerror(errno));
+ } else {
+ dropbear_exit("chown(%.100s, %u, %u) failed: %.100s",
+ tty_name, (unsigned int)pw->pw_uid, (unsigned int)gid,
+ strerror(errno));
+ }
+ }
+ }
+
+ if ((st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) != mode) {
+ if (chmod(tty_name, mode) < 0) {
+ if (errno == EROFS &&
+ (st.st_mode & (S_IRGRP | S_IROTH)) == 0) {
+ dropbear_log(LOG_ERR,
+ "chmod(%.100s, 0%o) failed: %.100s",
+ tty_name, mode, strerror(errno));
+ } else {
+ dropbear_exit("chmod(%.100s, 0%o) failed: %.100s",
+ tty_name, mode, strerror(errno));
+ }
+ }
+ }
+}