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author | 2012-12-03 20:08:33 +0000 | |
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committer | 2012-12-03 20:08:33 +0000 | |
commit | 8d2ec7ea7a3162017cc514cbd61e13ebc357af44 (patch) | |
tree | a719c1a18bcfc0cde90eaae03b55b823ea9630d8 /lib/libc/stdlib/posix_pty.c | |
parent | Close disk images if the client disconnects. This makes it possible to (diff) | |
download | wireguard-openbsd-8d2ec7ea7a3162017cc514cbd61e13ebc357af44.tar.xz wireguard-openbsd-8d2ec7ea7a3162017cc514cbd61e13ebc357af44.zip |
Simple emulation of POSIX pty APIs posix_openpt(), ptsname(),
grantpt() and unlockpt() using /dev/ptm. Man pages from FreeBSD.
OK kettenis@ deraadt@ beck@ ajacoutot@ naddy@
Diffstat (limited to 'lib/libc/stdlib/posix_pty.c')
-rw-r--r-- | lib/libc/stdlib/posix_pty.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/lib/libc/stdlib/posix_pty.c b/lib/libc/stdlib/posix_pty.c new file mode 100644 index 00000000000..a2025ddbb61 --- /dev/null +++ b/lib/libc/stdlib/posix_pty.c @@ -0,0 +1,119 @@ +/* $OpenBSD: posix_pty.c,v 1.1 2012/12/03 20:08:33 millert Exp $ */ + +/* + * Copyright (c) 2012 Todd C. Miller <Todd.Miller@courtesan.com> + * + * 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. + */ + +#include <sys/types.h> +#include <sys/ioctl.h> +#include <sys/stat.h> +#include <sys/tty.h> +#include <errno.h> +#include <fcntl.h> +#include <paths.h> +#include <stddef.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +int +posix_openpt(int oflag) +{ + struct ptmget ptm; + int fd, mfd = -1; + + /* User must specify O_RDWR in oflag. */ + if (!(oflag & O_RDWR)) { + errno = EINVAL; + return -1; + } + + /* Get pty master and slave (this API only uses the master). */ + fd = open(PATH_PTMDEV, O_RDWR); + if (fd != -1) { + if (ioctl(fd, PTMGET, &ptm) != -1) { + close(ptm.sfd); + mfd = ptm.cfd; + } + close(fd); + } + + return mfd; +} + +/* + * Look up the name of the specified pty master fd. + * Note that the name returned does *not* include the /dev/ prefix. + * Returns the name on success and NULL on error, setting errno. + */ +static const char * +ptmname(int mfd) +{ + struct stat sb; + const char *name; + + /* Make sure it is a pty master. */ + if (fstat(mfd, &sb) != 0) + return NULL; + if (!S_ISCHR(sb.st_mode)) { + errno = EINVAL; + return NULL; + } + name = devname(sb.st_rdev, S_IFCHR); + if (strncmp(name, "pty", 3) != 0) { + errno = EINVAL; + return NULL; + } + return name; +} + +/* + * The PTMGET ioctl handles the mode and owner for us. + */ +int +grantpt(int mfd) +{ + return ptmname(mfd) ? 0 : -1; +} + +/* + * The PTMGET ioctl unlocks the pty master and slave for us. + */ +int +unlockpt(int mfd) +{ + return ptmname(mfd) ? 0 : -1; +} + +/* + * Look up the path of the slave pty that corresponds to the master fd. + * Returns the path if successful or NULL on error. + */ +char * +ptsname(int mfd) +{ + const char *master; + static char slave[sizeof(((struct ptmget *)NULL)->sn)]; + + if ((master = ptmname(mfd)) == NULL) + return NULL; + + /* Add /dev/ prefix and convert "pty" to "tty". */ + strlcpy(slave, _PATH_DEV, sizeof(slave)); + strlcat(slave, master, sizeof(slave)); + slave[sizeof(_PATH_DEV) - 1] = 't'; + + return slave; +} |