fsade: Refactor the POSIX.1e abstractions

Since we're going to want to abstract more things that aren't part of
POSIX.1e (like xattrs) in a similar way, let's give this a more generic
name.  And while we're at it, give it some more precise error reporting,
and add some tests.

1 files changed, 0 insertions, 192 deletions

diff --git a/posix1e.c b/posix1e.c
deleted file mode 100644
index a898b39..0000000
--- a/posix1e.c
+++ /dev/null
@@ -1,192 +0,0 @@
-/****************************************************************************
- * bfs                                                                      *
- * Copyright (C) 2019 Tavian Barnes <tavianator@tavianator.com>             *
- *                                                                          *
- * Permission to use, copy, modify, and/or distribute this software for any *
- * purpose with or without fee is hereby granted.                           *
- *                                                                          *
- * 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.           *
- ****************************************************************************/
-
-#include "posix1e.h"
-#include "bftw.h"
-#include "util.h"
-#include <fcntl.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-#if BFS_HAS_SYS_ACL
-#	include <sys/acl.h>
-#endif
-
-#if BFS_HAS_POSIX1E_CAPABILITIES
-#	include <sys/capability.h>
-#endif
-
-#if BFS_HAS_SYS_ACL || BFS_HAS_POSIX1E_CAPABILITIES
-
-static const char *open_path(const struct BFTW *ftwbuf, int *fd) {
-#ifdef O_PATH
-	// The POSIX.1e APIS predate the *at() family of functions.  We'd still
-	// like to do something to avoid path re-traversals and limit races
-	// though.  Ideally we could just do openat(..., O_PATH) (since we may
-	// not have read access) and pass that fd to something like cap_get_fd()
-	// but that will fail since fgetxattr() needs read access to the file.
-	// The workaround is to use O_PATH to open an fd and then pass
-	// /proc/self/fd/<fd> to cap_get_path().  Inspired by
-	// https://android.googlesource.com/platform/bionic/+/2825f10b7f61558c264231a536cf3affc0d84204
-	int flags = O_PATH;
-	if (ftwbuf->stat_flags & BFS_STAT_NOFOLLOW) {
-		flags |= O_NOFOLLOW;
-	}
-
-	*fd = openat(ftwbuf->at_fd, ftwbuf->at_path, flags);
-	if (*fd < 0) {
-		return NULL;
-	}
-
-	size_t size = strlen("/proc/self/fd/") + CHAR_BIT*sizeof(int) + 1;
-	char *path = malloc(size);
-	if (!path) {
-		close(*fd);
-		*fd = -1;
-		return NULL;
-	}
-
-	snprintf(path, size, "/proc/self/fd/%d", *fd);
-	return path;
-#else
-	*fd = -1;
-	return ftwbuf->path;
-#endif
-}
-
-static void close_path(const struct BFTW *ftwbuf, const char *path, int fd) {
-	if (path && path != ftwbuf->path) {
-		free((void *)path);
-	}
-	if (fd >= 0) {
-		close(fd);
-	}
-}
-
-#endif // BFS_HAS_SYS_ACL || BFS_HAS_POSIX1E_CAPABILITIES
-
-#if BFS_HAS_SYS_ACL
-
-/** Check if any ACLs of the given type are non-trivial. */
-static bool bfs_check_acl_type(const char *path, acl_type_t type) {
-	acl_t acl = acl_get_file(path, type);
-	if (!acl) {
-		return false;
-	}
-
-	bool ret = false;
-	acl_entry_t entry;
-	for (int status = acl_get_entry(acl, ACL_FIRST_ENTRY, &entry);
-	     status > 0;
-	     status = acl_get_entry(acl, ACL_NEXT_ENTRY, &entry)) {
-#if defined(ACL_USER_OBJ) && defined(ACL_GROUP_OBJ) && defined(ACL_OTHER)
-		acl_tag_t tag;
-		if (acl_get_tag_type(entry, &tag) != 0) {
-			continue;
-		}
-		if (tag != ACL_USER_OBJ && tag != ACL_GROUP_OBJ && tag != ACL_OTHER) {
-			ret = true;
-			break;
-		}
-#else
-		ret = true;
-		break;
-#endif
-	}
-
-	acl_free(acl);
-	return ret;
-}
-
-bool bfs_check_acl(const struct BFTW *ftwbuf) {
-	if (ftwbuf->typeflag == BFTW_LNK) {
-		return false;
-	}
-
-	int fd;
-	const char *path = open_path(ftwbuf, &fd);
-	if (!path) {
-		return false;
-	}
-
-	bool ret = false;
-	if (bfs_check_acl_type(path, ACL_TYPE_ACCESS)) {
-		ret = true;
-	} else if (bfs_check_acl_type(path, ACL_TYPE_DEFAULT)) {
-		ret = true;
-#ifdef ACL_TYPE_EXTENDED
-	} else if (bfs_check_acl_type(path, ACL_TYPE_EXTENDED)) {
-		ret = true;
-#endif
-	}
-
-	close_path(ftwbuf, path, fd);
-	return ret;
-}
-
-#else // !BFS_HAS_SYS_ACL
-
-bool bfs_check_acl(const struct BFTW *ftwbuf) {
-	return false;
-}
-
-#endif
-
-#if BFS_HAS_POSIX1E_CAPABILITIES
-
-bool bfs_check_capabilities(const struct BFTW *ftwbuf) {
-	bool ret = false;
-
-	if (ftwbuf->typeflag == BFTW_LNK) {
-		goto out;
-	}
-
-	int fd;
-	const char *path = open_path(ftwbuf, &fd);
-	if (!path) {
-		goto out;
-	}
-
-	cap_t caps = cap_get_file(path);
-	if (!caps) {
-		goto out_close;
-	}
-
-	// TODO: Any better way to check for a non-empty capability set?
-	char *text = cap_to_text(caps, NULL);
-	if (!text) {
-		goto out_free_caps;
-	}
-	ret = text[0];
-
-	cap_free(text);
-out_free_caps:
-	cap_free(caps);
-out_close:
-	close_path(ftwbuf, path, fd);
-out:
-	return ret;
-}
-
-#else // !BFS_HAS_POSIX1E_CAPABILITIES
-
-bool bfs_check_capabilities(const struct BFTW *ftwbuf) {
-	return false;
-}
-
-#endif