/* Change the ownership and access permission of the slave pseudo
terminal associated with the master pseudo terminal specified
by FD. */
int
grantpt (int fd)
{
int retval = -1;
#ifdef PATH_MAX
char _buf[PATH_MAX];
#else
char _buf[512];
#endif
char *buf = _buf;
struct stat64 st;
if (__glibc_unlikely (pts_name (fd, &buf, sizeof (_buf), &st)))
{
int save_errno = errno;
/* Check, if the file descriptor is valid. pts_name returns the
wrong errno number, so we cannot use that. */
if (__libc_fcntl (fd, F_GETFD) == -1 && errno == EBADF)
return -1;
/* If the filedescriptor is no TTY, grantpt has to set errno
to EINVAL. */
if (save_errno == ENOTTY)
__set_errno (EINVAL);
else
__set_errno (save_errno);
return -1;
}
/* Make sure that we own the device. */
uid_t uid = __getuid ();
if (st.st_uid != uid)
{
if (__chown (buf, uid, st.st_gid) < 0)
goto helper;
}
static int tty_gid = -1;
if (__glibc_unlikely (tty_gid == -1))
{
char *grtmpbuf;
struct group grbuf;
size_t grbuflen = __sysconf (_SC_GETGR_R_SIZE_MAX);
struct group *p;
/* Get the group ID of the special `tty' group. */
if (grbuflen == (size_t) -1L)
/* `sysconf' does not support _SC_GETGR_R_SIZE_MAX.
Try a moderate value. */
grbuflen = 1024;
grtmpbuf = (char *) __alloca (grbuflen);
__getgrnam_r (TTY_GROUP, &grbuf, grtmpbuf, grbuflen, &p);
if (p != NULL)
tty_gid = p->gr_gid;
}
gid_t gid = tty_gid == -1 ? __getgid () : tty_gid;
/* Make sure the group of the device is that special group. */
if (st.st_gid != gid)
{
if (__chown (buf, uid, gid) < 0)
goto helper;
}
/* Make sure the permission mode is set to readable and writable by
the owner, and writable by the group. */
if ((st.st_mode & ACCESSPERMS) != (S_IRUSR|S_IWUSR|S_IWGRP))
{
if (__chmod (buf, S_IRUSR|S_IWUSR|S_IWGRP) < 0)
goto helper;
}
retval = 0;
goto cleanup;
/* We have to use the helper program if it is available. */
helper:;
#ifdef HAVE_PT_CHOWN
pid_t pid = __fork ();
if (pid == -1)
goto cleanup;
else if (pid == 0)
{
/* Disable core dumps. */
struct rlimit rl = { 0, 0 };
__setrlimit (RLIMIT_CORE, &rl);
/* We pass the master pseudo terminal as file descriptor PTY_FILENO. */
if (fd != PTY_FILENO)
if (__dup2 (fd, PTY_FILENO) < 0)
_exit (FAIL_EBADF);
# ifdef CLOSE_ALL_FDS
CLOSE_ALL_FDS ();
# endif
execle (_PATH_PT_CHOWN, basename (_PATH_PT_CHOWN), NULL, NULL);
_exit (FAIL_EXEC);
}
else
{
int w;
if (__waitpid (pid, &w, 0) == -1)
goto cleanup;
if (!WIFEXITED (w))
__set_errno (ENOEXEC);
else
switch (WEXITSTATUS (w))
{
case 0:
retval = 0;
break;
case FAIL_EBADF:
__set_errno (EBADF);
break;
case FAIL_EINVAL:
__set_errno (EINVAL);
break;
case FAIL_EACCES:
__set_errno (EACCES);
break;
case FAIL_EXEC:
__set_errno (ENOEXEC);
break;
case FAIL_ENOMEM:
__set_errno (ENOMEM);
break;
default:
assert(! "getpt: internal error: invalid exit code from pt_chown");
}
}
#endif
cleanup:
if (buf != _buf)
free (buf);
return retval;
}
int
mtev_security_usergroup(const char *user, const char *group, mtev_boolean effective) {
static long pwnam_buflen = 0;
static long grnam_buflen = 0;
uid_t uid = 0;
gid_t gid = 0;
if(pwnam_buflen == 0)
#ifdef _SC_GETPW_R_SIZE_MAX
pwnam_buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
#else
pwnam_buflen = 100; /* This shouldn't be used, so size is not important. */
#endif
if(grnam_buflen == 0)
#ifdef _SC_GETGR_R_SIZE_MAX
grnam_buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
#else
grnam_buflen = 100;
#endif
if(user) {
if(isuinteger(user)) uid = atoi(user);
else {
struct passwd *pw, _pw;
char *buf;
if(NULL == (buf = alloca(pwnam_buflen))) BAIL("alloca failed\n");
if(NULL == (pw = __getpwnam_r(user, &_pw, buf, pwnam_buflen)))
BAIL("Cannot find user '%s'\n", user);
uid = pw->pw_uid;
}
}
if(group) {
if(isuinteger(group)) gid = atoi(group);
else {
struct group *gr, _gr;
char *buf;
if(NULL == (buf = alloca(grnam_buflen))) BAIL("alloca failed\n");
if(NULL == (gr = __getgrnam_r(group, &_gr, buf, grnam_buflen)))
BAIL("Cannot find group '%s'\n", group);
gid = gr->gr_gid;
}
}
if(!user && !group) return 0;
#if defined(CAP_SUPPORTED) && defined(HAVE_SETPPRIV)
if(!effective && getpflags(PRIV_AWARE)) {
int rv;
priv_set_t *set;
set = priv_allocset();
priv_addset(set, "proc_setid");
rv = setppriv(PRIV_ON, PRIV_EFFECTIVE, set);
priv_freeset(set);
if(rv) BAIL("setppriv(proc_setid) failed");
}
#endif
if(group) {
if(!effective && gid == 0) BAIL("Cannot use this function to setgid(0)\n");
if((effective ? setegid(gid) : setgid(gid)) != 0)
BAIL("setgid(%d) failed: %s\n", (int)gid, strerror(errno));
}
if(user) {
if(!effective && uid == 0) BAIL("Cannot use this function to setuid(0)\n");
if((effective ? seteuid(uid) : setuid(uid)) != 0)
BAIL("setgid(%d) failed: %s\n", (int)gid, strerror(errno));
if(!effective) {
#if defined(CAP_SUPPORTED) && defined(HAVE_SETPPRIV)
if(getpflags(PRIV_AWARE)) {
int rv;
priv_set_t *set;
set = priv_allocset();
priv_addset(set, "proc_setid");
rv = setppriv(PRIV_OFF, PRIV_EFFECTIVE, set);
if(rv) BAIL("setppriv(off, effective, proc_setid) failed");
getppriv(PRIV_EFFECTIVE, set);
rv = setppriv(PRIV_SET, PRIV_PERMITTED, set);
if(rv) BAIL("setppriv(effective -> permitted) failed");
priv_freeset(set);
}
#endif
if(setuid(0) == 0) BAIL("setuid(0) worked, and it shouldn't have.\n");
if(setgid(0) == 0) BAIL("setgid(0) worked, and it shouldn't have.\n");
}
}
return 0;
}
