diff options
Diffstat (limited to 'src/get_pty.c')
| -rw-r--r-- | src/get_pty.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/src/get_pty.c b/src/get_pty.c new file mode 100644 index 0000000..e50a9a6 --- /dev/null +++ b/src/get_pty.c @@ -0,0 +1,192 @@ +/* + * SPDX-License-Identifier: ISC + * + * 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/stat.h> +#include <sys/ioctl.h> +#ifdef HAVE_SYS_STROPTS_H +#include <sys/stropts.h> +#endif /* HAVE_SYS_STROPTS_H */ +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <errno.h> +#include <fcntl.h> +#include <grp.h> + +#if defined(HAVE_OPENPTY) +# if defined(HAVE_LIBUTIL_H) +# include <libutil.h> /* *BSD */ +# elif defined(HAVE_UTIL_H) +# include <util.h> /* macOS */ +# elif defined(HAVE_PTY_H) +# include <pty.h> /* Linux */ +# else +# include <termios.h> /* Solaris */ +# endif +#endif + +#include "sudo.h" + +#if defined(HAVE_OPENPTY) +bool +get_pty(int *leader, int *follower, 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(leader, follower, name, NULL, NULL) == 0) { + if (chown(name, ttyuid, ttygid) == 0) + ret = true; + } + + debug_return_bool(ret); +} + +#elif defined(HAVE__GETPTY) +bool +get_pty(int *leader, int *follower, 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(leader, O_RDWR, S_IRUSR|S_IWUSR|S_IWGRP, 0); + if (line != NULL) { + *follower = open(line, O_RDWR|O_NOCTTY, 0); + if (*follower != -1) { + (void) chown(line, ttyuid, -1); + strlcpy(name, line, namesz); + ret = true; + } else { + close(*leader); + *leader = -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 *leader, int *follower, char *name, size_t namesz, uid_t ttyuid) +{ + char *line; + bool ret = false; + debug_decl(get_pty, SUDO_DEBUG_PTY); + + *leader = posix_openpt(O_RDWR|O_NOCTTY); + if (*leader != -1) { + (void) grantpt(*leader); /* may fork */ + if (unlockpt(*leader) != 0) { + close(*leader); + goto done; + } + line = ptsname(*leader); + if (line == NULL) { + close(*leader); + goto done; + } + *follower = open(line, O_RDWR|O_NOCTTY, 0); + if (*follower == -1) { + close(*leader); + goto done; + } +# if defined(I_PUSH) && !defined(_AIX) + ioctl(*follower, I_PUSH, "ptem"); /* pseudo tty emulation module */ + ioctl(*follower, 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 *leader, int *follower, 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; + *leader = open(line, O_RDWR|O_NOCTTY, 0); + if (*leader == -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 + *follower = open(line, O_RDWR|O_NOCTTY, 0); + if (*follower != -1) { + strlcpy(name, line, namesz); + ret = true; /* success */ + goto done; + } + (void) close(*leader); + } + } +done: + debug_return_bool(ret); +} +#endif /* HAVE_OPENPTY */ |