diff options
Diffstat (limited to 'pty.c')
| -rw-r--r-- | pty.c | 264 |
1 files changed, 264 insertions, 0 deletions
@@ -0,0 +1,264 @@ +/* + +pty.c + +Author: Tatu Ylonen <ylo@cs.hut.fi> + +Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland + All rights reserved + +Created: Fri Mar 17 04:37:25 1995 ylo + +Allocating a pseudo-terminal, and making it the controlling tty. + +*/ + +#include "includes.h" +RCSID("$Id: pty.c,v 1.1 1999/10/27 03:42:44 damien Exp $"); + +#include "pty.h" +#include "ssh.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 + +#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) +{ +#ifdef HAVE_OPENPTY + + /* openpty(3) exists in OSF/1 and some other os'es */ + + int i; + + i = openpty(ptyfd, ttyfd, namebuf, NULL, NULL); + + if (i < 0) + { + error("openpty: %.100s", strerror(errno)); + return 0; + } + + 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) + { + error("_getpty: %.100s", strerror(errno)); + return 0; + } + strcpy(namebuf, slave); + /* 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; + +#else /* HAVE__GETPTY */ +#ifdef 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; + + ptm = open("/dev/ptmx", O_RDWR|O_NOCTTY); + if (ptm < 0) + { + error("/dev/ptmx: %.100s", strerror(errno)); + return 0; + } + if (grantpt(ptm) < 0) + { + error("grantpt: %.100s", strerror(errno)); + return 0; + } + 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."); + strcpy(namebuf, pts); + *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; + } + /* Push the appropriate streams modules, as described in Solaris pts(7). */ + 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)); + if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0) + error("ioctl I_PUSH ttcompat: %.100s", strerror(errno)); + return 1; + +#else /* HAVE_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) + { + 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."); + strcpy(namebuf, name); + *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; + +#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; + + for (i = 0; i < num_ptys; i++) + { + snprintf(buf, sizeof buf, "/dev/pty%c%c", ptymajors[i / num_minors], + ptyminors[i % num_minors]); + *ptyfd = open(buf, O_RDWR|O_NOCTTY); + if (*ptyfd < 0) + continue; + snprintf(namebuf, sizeof buf, "/dev/tty%c%c", ptymajors[i / num_minors], + ptyminors[i % num_minors]); + + /* 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; +#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. */ + +void pty_release(const char *ttyname) +{ + if (chown(ttyname, (uid_t)0, (gid_t)0) < 0) + debug("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno)); + if (chmod(ttyname, (mode_t)0666) < 0) + debug("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno)); +} + +/* Makes the tty the processes controlling tty and sets it to sane modes. */ + +void pty_make_controlling_tty(int *ttyfd, const char *ttyname) +{ + int fd; + + /* First disconnect from the old controlling tty. */ +#ifdef TIOCNOTTY + fd = open("/dev/tty", O_RDWR|O_NOCTTY); + if (fd >= 0) + { + (void)ioctl(fd, TIOCNOTTY, NULL); + close(fd); + } +#endif /* TIOCNOTTY */ + if (setsid() < 0) + error("setsid: %.100s", strerror(errno)); + + /* Verify that we are successfully disconnected from the controlling tty. */ + fd = open("/dev/tty", O_RDWR|O_NOCTTY); + if (fd >= 0) + { + error("Failed to disconnect from controlling tty."); + close(fd); + } + + /* Make it our controlling tty. */ +#ifdef TIOCSCTTY + debug("Setting controlling tty using TIOCSCTTY."); + /* We ignore errors from this, because HPSUX defines TIOCSCTTY, but returns + EINVAL with these arguments, and there is absolutely no documentation. */ + ioctl(*ttyfd, TIOCSCTTY, NULL); +#endif /* TIOCSCTTY */ + fd = open(ttyname, O_RDWR); + if (fd < 0) + error("%.100s: %.100s", ttyname, strerror(errno)); + else + close(fd); + + /* Verify that we now have a controlling tty. */ + fd = open("/dev/tty", O_WRONLY); + if (fd < 0) + error("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); +} + |