char *
do_case_sensitive_path (const char *path)
{
char ret[PATH_MAX+1] = "/";
size_t next = 1;
int fd_cwd;
/* 'fd_cwd' here is a surrogate for the current working directory, so
* that we don't have to actually call chdir(2).
*/
fd_cwd = open (sysroot, O_RDONLY | O_DIRECTORY);
if (fd_cwd == -1) {
reply_with_perror ("%s", sysroot);
return NULL;
}
/* First character is a '/'. Take each subsequent path element
* and follow it.
*/
while (*path) {
size_t i = strcspn (path, "/");
if (i == 0) {
path++;
continue;
}
if ((i == 1 && path[0] == '.') ||
(i == 2 && path[0] == '.' && path[1] == '.')) {
reply_with_error ("path contained . or .. elements");
goto error;
}
if (i > NAME_MAX) {
reply_with_error ("path element too long");
goto error;
}
char name[NAME_MAX+1];
memcpy (name, path, i);
name[i] = '\0';
/* Skip to next element in path (for the next loop iteration). */
path += i;
/* Read the current directory looking (case insensitively) for
* this element of the path. This replaces 'name' with the
* correct case version.
*/
if (find_path_element (fd_cwd, name, &i) == -1)
goto error;
/* Add the real name of this path element to the return value. */
if (next > 1)
ret[next++] = '/';
if (next + i >= PATH_MAX) {
reply_with_error ("final path too long");
goto error;
}
strcpy (&ret[next], name);
next += i;
/* Is it a directory? Try going into it. */
int fd2 = openat (fd_cwd, name, O_RDONLY | O_DIRECTORY);
int err = errno;
close (fd_cwd);
fd_cwd = fd2;
errno = err;
if (fd_cwd == -1) {
/* ENOTDIR is OK provided we've reached the end of the path. */
if (errno != ENOTDIR) {
reply_with_perror ("openat: %s", name);
goto error;
}
if (*path) {
reply_with_error ("%s: non-directory element in path", name);
goto error;
}
}
}
if (fd_cwd >= 0)
close (fd_cwd);
ret[next] = '\0';
char *retp = strdup (ret);
if (retp == NULL) {
reply_with_perror ("strdup");
return NULL;
}
return retp; /* caller frees */
error:
if (fd_cwd >= 0)
close (fd_cwd);
return NULL;
}
char *
do_case_sensitive_path (const char *path)
{
size_t next;
int fd_cwd, fd2, err, is_end;
char *ret;
ret = strdup ("/");
if (ret == NULL) {
reply_with_perror ("strdup");
return NULL;
}
next = 1; /* next position in 'ret' buffer */
/* 'fd_cwd' here is a surrogate for the current working directory, so
* that we don't have to actually call chdir(2).
*/
fd_cwd = open (sysroot, O_RDONLY|O_DIRECTORY|O_CLOEXEC);
if (fd_cwd == -1) {
reply_with_perror ("%s", sysroot);
goto error;
}
/* First character is a '/'. Take each subsequent path element
* and follow it.
*/
while (*path) {
char *t;
size_t i, len;
CLEANUP_FREE char *name_in = NULL, *name_out = NULL;
i = strcspn (path, "/");
if (i == 0) {
path++;
continue;
}
if ((i == 1 && path[0] == '.') ||
(i == 2 && path[0] == '.' && path[1] == '.')) {
reply_with_error ("path contained . or .. elements");
goto error;
}
name_in = strndup (path, i);
if (name_in == NULL) {
reply_with_perror ("strdup");
goto error;
}
/* Skip to next element in path (for the next loop iteration). */
path += i;
is_end = *path == 0;
/* Read the current directory looking (case insensitively) for
* this element of the path. This replaces 'name' with the
* correct case version.
*/
if (find_path_element (fd_cwd, is_end, name_in, &name_out) == -1)
goto error;
len = strlen (name_out);
/* Add the real name of this path element to the return value. */
if (next > 1)
ret[next++] = '/';
t = realloc (ret, next+len+1);
if (t == NULL) {
reply_with_perror ("realloc");
goto error;
}
ret = t;
strcpy (&ret[next], name_out);
next += len;
/* Is it a directory? Try going into it. */
fd2 = openat (fd_cwd, name_out, O_RDONLY|O_DIRECTORY|O_CLOEXEC);
err = errno;
close (fd_cwd);
fd_cwd = fd2;
errno = err;
if (fd_cwd == -1) {
/* Some errors are OK provided we've reached the end of the path. */
if (is_end && (errno == ENOTDIR || errno == ENOENT))
break;
reply_with_perror ("openat: %s", name_out);
goto error;
}
}
if (fd_cwd >= 0)
close (fd_cwd);
return ret; /* caller frees */
error:
if (fd_cwd >= 0)
close (fd_cwd);
free (ret);
return NULL;
}
