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-rw-r--r--src/get_pty.c195
1 files changed, 195 insertions, 0 deletions
diff --git a/src/get_pty.c b/src/get_pty.c
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+/*
+ * Copyright (c) 2009-2012, 2014-2016
+ * Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * 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.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#ifdef HAVE_SYS_STROPTS_H
+#include <sys/stropts.h>
+#endif /* HAVE_SYS_STROPTS_H */
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef HAVE_STRING_H
+# include <string.h>
+#endif /* HAVE_STRING_H */
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif /* HAVE_STRINGS_H */
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <pwd.h>
+
+#if defined(HAVE_LIBUTIL_H)
+# include <libutil.h>
+#elif defined(HAVE_UTIL_H)
+# include <util.h>
+#endif
+#ifdef HAVE_PTY_H
+# include <pty.h>
+#endif
+
+#include "sudo.h"
+
+#if defined(HAVE_OPENPTY)
+bool
+get_pty(int *master, int *slave, char *name, size_t namesz, uid_t ttyuid)
+{
+ struct group *gr;
+ gid_t ttygid = -1;
+ bool ret = false;
+ debug_decl(get_pty, SUDO_DEBUG_PTY)
+
+ if ((gr = getgrnam("tty")) != NULL)
+ ttygid = gr->gr_gid;
+
+ if (openpty(master, slave, name, NULL, NULL) == 0) {
+ if (chown(name, ttyuid, ttygid) == 0)
+ ret = true;
+ }
+
+ debug_return_bool(ret);
+}
+
+#elif defined(HAVE__GETPTY)
+bool
+get_pty(int *master, int *slave, char *name, size_t namesz, uid_t ttyuid)
+{
+ char *line;
+ bool ret = false;
+ debug_decl(get_pty, SUDO_DEBUG_PTY)
+
+ /* IRIX-style dynamic ptys (may fork) */
+ line = _getpty(master, O_RDWR, S_IRUSR|S_IWUSR|S_IWGRP, 0);
+ if (line != NULL) {
+ *slave = open(line, O_RDWR|O_NOCTTY, 0);
+ if (*slave != -1) {
+ (void) chown(line, ttyuid, -1);
+ strlcpy(name, line, namesz);
+ ret = true;
+ } else {
+ close(*master);
+ *master = -1;
+ }
+ }
+ debug_return_bool(ret);
+}
+#elif defined(HAVE_GRANTPT)
+# ifndef HAVE_POSIX_OPENPT
+static int
+posix_openpt(int oflag)
+{
+ int fd;
+
+# ifdef _AIX
+ fd = open(_PATH_DEV "ptc", oflag);
+# else
+ fd = open(_PATH_DEV "ptmx", oflag);
+# endif
+ return fd;
+}
+# endif /* HAVE_POSIX_OPENPT */
+
+bool
+get_pty(int *master, int *slave, char *name, size_t namesz, uid_t ttyuid)
+{
+ char *line;
+ bool ret = false;
+ debug_decl(get_pty, SUDO_DEBUG_PTY)
+
+ *master = posix_openpt(O_RDWR|O_NOCTTY);
+ if (*master != -1) {
+ (void) grantpt(*master); /* may fork */
+ if (unlockpt(*master) != 0) {
+ close(*master);
+ goto done;
+ }
+ line = ptsname(*master);
+ if (line == NULL) {
+ close(*master);
+ goto done;
+ }
+ *slave = open(line, O_RDWR|O_NOCTTY, 0);
+ if (*slave == -1) {
+ close(*master);
+ goto done;
+ }
+# if defined(I_PUSH) && !defined(_AIX)
+ ioctl(*slave, I_PUSH, "ptem"); /* pseudo tty emulation module */
+ ioctl(*slave, I_PUSH, "ldterm"); /* line discipline module */
+# endif
+ (void) chown(line, ttyuid, -1);
+ strlcpy(name, line, namesz);
+ ret = true;
+ }
+done:
+ debug_return_bool(ret);
+}
+
+#else /* Old-style BSD ptys */
+
+static char line[] = _PATH_DEV "ptyXX";
+
+bool
+get_pty(int *master, int *slave, char *name, size_t namesz, uid_t ttyuid)
+{
+ char *bank, *cp;
+ struct group *gr;
+ gid_t ttygid = -1;
+ bool ret = false;
+ debug_decl(get_pty, SUDO_DEBUG_PTY)
+
+ if ((gr = getgrnam("tty")) != NULL)
+ ttygid = gr->gr_gid;
+
+ for (bank = "pqrs"; *bank != '\0'; bank++) {
+ line[sizeof(_PATH_DEV "ptyX") - 2] = *bank;
+ for (cp = "0123456789abcdef"; *cp != '\0'; cp++) {
+ line[sizeof(_PATH_DEV "ptyXX") - 2] = *cp;
+ *master = open(line, O_RDWR|O_NOCTTY, 0);
+ if (*master == -1) {
+ if (errno == ENOENT)
+ goto done; /* out of ptys */
+ continue; /* already in use */
+ }
+ line[sizeof(_PATH_DEV "p") - 2] = 't';
+ (void) chown(line, ttyuid, ttygid);
+ (void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP);
+# ifdef HAVE_REVOKE
+ (void) revoke(line);
+# endif
+ *slave = open(line, O_RDWR|O_NOCTTY, 0);
+ if (*slave != -1) {
+ strlcpy(name, line, namesz);
+ ret = true; /* success */
+ goto done;
+ }
+ (void) close(*master);
+ }
+ }
+done:
+ debug_return_bool(ret);
+}
+#endif /* HAVE_OPENPTY */