/* * Please note: this implementation of openpty() is far from complete. * it is just enough for portable OpenSSH's needs. */ /* * Copyright (c) 2004 Damien Miller * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , 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". */ #include "includes.h" #if !defined(HAVE_OPENPTY) #include #include #ifdef HAVE_SYS_STAT_H # include #endif #ifdef HAVE_SYS_IOCTL_H # include #endif #ifdef HAVE_FCNTL_H # include #endif #ifdef HAVE_UTIL_H # include #endif /* HAVE_UTIL_H */ #ifdef HAVE_PTY_H # include #endif #if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H) # include #endif #include #include #include #include "misc.h" #include "log.h" #ifndef O_NOCTTY #define O_NOCTTY 0 #endif #if defined(HAVE_DEV_PTMX) && !defined(HAVE__GETPTY) static int openpty_streams(int *amaster, int *aslave) { /* * 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; sshsig_t old_signal; if ((ptm = open("/dev/ptmx", O_RDWR | O_NOCTTY)) == -1) return (-1); /* XXX: need to close ptm on error? */ old_signal = ssh_signal(SIGCHLD, SIG_DFL); if (grantpt(ptm) < 0) return (-1); ssh_signal(SIGCHLD, old_signal); if (unlockpt(ptm) < 0) return (-1); if ((pts = ptsname(ptm)) == NULL) return (-1); *amaster = ptm; /* Open the slave side. */ if ((*aslave = open(pts, O_RDWR | O_NOCTTY)) == -1) { close(*amaster); return (-1); } # if defined(I_FIND) && defined(__SVR4) /* * If the streams modules have already been pushed then there * is no more work to do here. */ if (ioctl(*aslave, I_FIND, "ptem") != 0) return 0; # endif /* * Try to push the appropriate streams modules, as described * in Solaris pts(7). */ ioctl(*aslave, I_PUSH, "ptem"); ioctl(*aslave, I_PUSH, "ldterm"); # ifndef __hpux ioctl(*aslave, I_PUSH, "ttcompat"); # endif /* __hpux */ return (0); } #endif int openpty(int *amaster, int *aslave, char *name, struct termios *termp, struct winsize *winp) { #if defined(HAVE__GETPTY) /* * _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more * pty's automagically when needed */ char *slave; if ((slave = _getpty(amaster, O_RDWR, 0622, 0)) == NULL) return (-1); /* Open the slave side. */ if ((*aslave = open(slave, O_RDWR | O_NOCTTY)) == -1) { close(*amaster); return (-1); } return (0); #elif defined(HAVE_DEV_PTMX) #ifdef SSHD_ACQUIRES_CTTY /* * On some (most? all?) SysV based systems with STREAMS based terminals, * sshd will acquire a controlling terminal when it pushes the "ptem" * module. On such platforms, first allocate a sacrificial pty so * that sshd already has a controlling terminal before allocating the * one that will be passed back to the user process. This ensures * the second pty is not already the controlling terminal for a * different session and is available to become controlling terminal * for the client's subprocess. See bugzilla #245 for details. */ int r, fd; static int junk_ptyfd = -1, junk_ttyfd; r = openpty_streams(amaster, aslave); if (junk_ptyfd == -1 && (fd = open(_PATH_TTY, O_RDWR|O_NOCTTY)) >= 0) { close(fd); junk_ptyfd = *amaster; junk_ttyfd = *aslave; debug("STREAMS bug workaround pty %d tty %d name %s", junk_ptyfd, junk_ttyfd, ttyname(junk_ttyfd)); } else return r; #endif return openpty_streams(amaster, aslave); #elif defined(HAVE_DEV_PTS_AND_PTC) /* AIX-style pty code. */ const char *ttname; if ((*amaster = open("/dev/ptc", O_RDWR | O_NOCTTY)) == -1) return (-1); if ((ttname = ttyname(*amaster)) == NULL) return (-1); if ((*aslave = open(ttname, O_RDWR | O_NOCTTY)) == -1) { close(*amaster); return (-1); } return (0); #else /* BSD-style pty code. */ char ptbuf[64], ttbuf[64]; int i; const char *ptymajors = "pqrstuvwxyzabcdefghijklmno" "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; 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(ptbuf, sizeof(ptbuf), "/dev/pty%c%c", ptymajors[i / num_minors], ptyminors[i % num_minors]); snprintf(ttbuf, sizeof(ttbuf), "/dev/tty%c%c", ptymajors[i / num_minors], ptyminors[i % num_minors]); if ((*amaster = open(ptbuf, O_RDWR | O_NOCTTY)) == -1) { /* Try SCO style naming */ snprintf(ptbuf, sizeof(ptbuf), "/dev/ptyp%d", i); snprintf(ttbuf, sizeof(ttbuf), "/dev/ttyp%d", i); if ((*amaster = open(ptbuf, O_RDWR | O_NOCTTY)) == -1) continue; } /* Open the slave side. */ if ((*aslave = open(ttbuf, O_RDWR | O_NOCTTY)) == -1) { close(*amaster); return (-1); } /* set tty modes to a sane state for broken clients */ if (tcgetattr(*amaster, &tio) != -1) { tio.c_lflag |= (ECHO | ISIG | ICANON); tio.c_oflag |= (OPOST | ONLCR); tio.c_iflag |= ICRNL; tcsetattr(*amaster, TCSANOW, &tio); } return (0); } return (-1); #endif } #endif /* !defined(HAVE_OPENPTY) */