--- /dev/null
+/*
+ * Copyright (c) 2002 The FreeBSD Project, Inc.
+ * All rights reserved.
+ *
+ * This software includes code contributed to the FreeBSD Project
+ * by Ryan Younce of North Carolina State University.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the FreeBSD Project nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE FREEBSD PROJECT AND CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE FREEBSD PROJECT OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#ifndef lint
+__FBSDID("$FreeBSD: src/lib/libc/stdlib/grantpt.c,v 1.2 2003/01/04 08:10:55 tjr Exp $");
+#endif /* not lint */
+
+#include "namespace.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <paths.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sysexits.h>
+#include <unistd.h>
+#include "un-namespace.h"
+
+#define PTM_MAJOR 6 /* pseudo tty master major */
+#define PTS_MAJOR 5 /* pseudo tty slave major */
+#define PTM_PREFIX "pty" /* pseudo tty master naming convention */
+#define PTS_PREFIX "tty" /* pseudo tty slave naming convention */
+
+/*
+ * The following are range values for pseudo TTY devices. Pseudo TTYs have a
+ * name of /dev/[pt]ty[p-sP-S][0-9a-v], yielding 256 combinations per major.
+ */
+#define PT_MAX 256
+#define PT_DEV1 "pqrsPQRS"
+#define PT_DEV2 "0123456789abcdefghijklmnopqrstuv"
+
+/*
+ * grantpt(3) support utility.
+ */
+#define _PATH_PTCHOWN "/usr/libexec/pt_chown"
+
+/*
+ * ISPTM(x) returns 0 for struct stat x if x is not a pty master.
+ * The bounds checking may be unnecessary but it does eliminate doubt.
+ */
+#define ISPTM(x) (S_ISCHR((x).st_mode) && \
+ major((x).st_rdev) == PTM_MAJOR && \
+ minor((x).st_rdev) >= 0 && \
+ minor((x).st_rdev) < PT_MAX)
+
+/*
+ * grantpt(): grant ownership of a slave pseudo-terminal device to the
+ * current user.
+ */
+
+int
+grantpt(int fildes)
+{
+ int retval, serrno, status;
+ pid_t pid, spid;
+ gid_t gid;
+ char *slave;
+ sigset_t oblock, nblock;
+ struct group *grp;
+
+ retval = -1;
+ serrno = errno;
+
+ if ((slave = ptsname(fildes)) != NULL) {
+ /*
+ * Block SIGCHLD.
+ */
+ (void)sigemptyset(&nblock);
+ (void)sigaddset(&nblock, SIGCHLD);
+ (void)_sigprocmask(SIG_BLOCK, &nblock, &oblock);
+
+ switch (pid = fork()) {
+ case -1:
+ break;
+ case 0: /* child */
+ /*
+ * pt_chown expects the master pseudo TTY to be its
+ * standard input.
+ */
+ (void)_dup2(fildes, STDIN_FILENO);
+ (void)_sigprocmask(SIG_SETMASK, &oblock, NULL);
+ execl(_PATH_PTCHOWN, _PATH_PTCHOWN, (char *)NULL);
+ _exit(EX_UNAVAILABLE);
+ /* NOTREACHED */
+ default: /* parent */
+ /*
+ * Just wait for the process. Error checking is
+ * done below.
+ */
+ while ((spid = _waitpid(pid, &status, 0)) == -1 &&
+ (errno == EINTR))
+ ;
+ if (spid != -1 && WIFEXITED(status) &&
+ WEXITSTATUS(status) == EX_OK)
+ retval = 0;
+ else
+ errno = EACCES;
+ break;
+ }
+
+ /*
+ * Restore process's signal mask.
+ */
+ (void)_sigprocmask(SIG_SETMASK, &oblock, NULL);
+
+ if (retval) {
+ /*
+ * pt_chown failed. Try to manually change the
+ * permissions for the slave.
+ */
+ gid = (grp = getgrnam("tty")) ? grp->gr_gid : -1;
+ if (chown(slave, getuid(), gid) == -1 ||
+ chmod(slave, S_IRUSR | S_IWUSR | S_IWGRP) == -1)
+ errno = EACCES;
+ else
+ retval = 0;
+ }
+ }
+
+ if (!retval)
+ errno = serrno;
+
+ return (retval);
+}
+
+/*
+ * posix_openpt(): open the first available master pseudo-terminal device
+ * and return descriptor.
+ */
+int
+posix_openpt(int oflag)
+{
+ char *mc1, *mc2, master[] = _PATH_DEV PTM_PREFIX "XY";
+ const char *pc1, *pc2;
+ int fildes, bflag, serrno;
+
+ fildes = -1;
+ bflag = 0;
+ serrno = errno;
+
+ /*
+ * Check flag validity. POSIX doesn't require it,
+ * but we still do so.
+ */
+ if (oflag & ~(O_RDWR | O_NOCTTY))
+ errno = EINVAL;
+ else {
+ mc1 = master + strlen(_PATH_DEV PTM_PREFIX);
+ mc2 = mc1 + 1;
+
+ /* Cycle through all possible master PTY devices. */
+ for (pc1 = PT_DEV1; !bflag && (*mc1 = *pc1); ++pc1)
+ for (pc2 = PT_DEV2; (*mc2 = *pc2) != '\0'; ++pc2) {
+ /*
+ * Break out if we successfully open a PTY,
+ * or if open() fails due to limits.
+ */
+ if ((fildes = _open(master, oflag)) != -1 ||
+ (errno == EMFILE || errno == ENFILE)) {
+ ++bflag;
+ break;
+ }
+ }
+
+ if (fildes != -1)
+ errno = serrno;
+ else if (!bflag)
+ errno = EAGAIN;
+ }
+
+ return (fildes);
+}
+
+/*
+ * ptsname(): return the pathname of the slave pseudo-terminal device
+ * associated with the specified master.
+ */
+char *
+ptsname(int fildes)
+{
+ static char slave[] = _PATH_DEV PTS_PREFIX "XY";
+ char *retval;
+ struct stat sbuf;
+
+ retval = NULL;
+
+ if (_fstat(fildes, &sbuf) == 0) {
+ if (!ISPTM(sbuf))
+ errno = EINVAL;
+ else {
+ (void)sprintf(slave, _PATH_DEV PTS_PREFIX "%c%c",
+ PT_DEV1[minor(sbuf.st_rdev) / 32],
+ PT_DEV2[minor(sbuf.st_rdev) % 32]);
+ retval = slave;
+ }
+ }
+
+ return (retval);
+}
+
+/*
+ * unlockpt(): unlock a pseudo-terminal device pair.
+ */
+int
+unlockpt(int fildes)
+{
+ int retval;
+ struct stat sbuf;
+
+ /*
+ * Unlocking a master/slave pseudo-terminal pair has no meaning in a
+ * non-streams PTY environment. However, we do ensure fildes is a
+ * valid master pseudo-terminal device.
+ */
+ if ((retval = _fstat(fildes, &sbuf)) == 0 && !ISPTM(sbuf)) {
+ errno = EINVAL;
+ retval = -1;
+ }
+
+ return (retval);
+}
projects / apple / libc.git / blobdiff