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/*
* mkdir*() pre-check.
*
* Copyright 1999-2009 Gentoo Foundation
* Licensed under the GPL-2
*/
bool sb_mkdirat_pre_check(const char *func, const char *pathname, int dirfd)
{
char canonic[SB_PATH_MAX];
char dirfd_path[SB_PATH_MAX];
save_errno();
/* Expand the dirfd path first */
switch (resolve_dirfd_path(dirfd, pathname, dirfd_path)) {
case -1:
if (is_env_on(ENV_SANDBOX_DEBUG))
SB_EINFO("EARLY FAIL", " %s(%s) @ resolve_dirfd_path: %s\n",
func, pathname, strerror(errno));
return false;
case 0:
pathname = dirfd_path;
break;
}
/* Then break down any relative/symlink paths */
if (-1 == canonicalize(pathname, canonic))
/* see comments in check_syscall() */
if (ENAMETOOLONG != errno) {
if (is_env_on(ENV_SANDBOX_DEBUG))
SB_EINFO("EARLY FAIL", " %s(%s) @ canonicalize: %s\n",
func, pathname, strerror(errno));
return false;
}
/* XXX: Hack to prevent errors if the directory exist, and are
* not writable - we rather return EEXIST than fail. This can
* occur if doing something like `mkdir -p /`. We certainly do
* not want to pass this attempt up to the higher levels as those
* will trigger a sandbox violation.
*/
struct stat st;
if (0 == lstat(canonic, &st)) {
int new_errno;
if (is_env_on(ENV_SANDBOX_DEBUG))
SB_EINFO("EARLY FAIL", " %s(%s[%s]) @ lstat: %s\n",
func, pathname, canonic, strerror(errno));
new_errno = EEXIST;
/* Hmm, is this a broken symlink we're trying to extend ? */
if (S_ISLNK(st.st_mode) && stat(pathname, &st) != 0) {
/* XXX: This awful hack should probably be turned into a
* common func that does a better job. For now, we have
* enough crap to catch gnulib tests #297026.
*/
char *parent = strrchr(pathname, '/');
if (parent && (strcmp(parent, "/.") == 0 || strcmp(parent, "/..") == 0))
new_errno = ENOENT;
}
errno = new_errno;
return false;
}
restore_errno();
return true;
}
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