posix1e: Split out ACL and capability handling from util

9 files changed, 248 insertions, 185 deletions

diff --git a/COPYING b/COPYING
index 670e870..ac9a6a7 100644
--- a/COPYING
+++ b/COPYING
@@ -1,4 +1,4 @@
-Copyright (C) 2015-2018 Tavian Barnes <tavianator@tavianator.com>
+Copyright (C) 2015-2019 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.
diff --git a/Makefile b/Makefile
index c631c35..319680c 100644
--- a/Makefile
+++ b/Makefile
@@ -63,7 +63,23 @@ ALL_LDLIBS = $(LOCAL_LDLIBS) $(LDLIBS)
 
 all: bfs
 
-bfs: bftw.o color.o diag.o dstring.o eval.o exec.o main.o mtab.o opt.o parse.o printf.o spawn.o stat.o typo.o util.o
+bfs: \
+    bftw.o \
+    color.o \
+    diag.o \
+    dstring.o \
+    eval.o \
+    exec.o \
+    main.o \
+    mtab.o \
+    opt.o \
+    parse.o \
+    posix1e.o \
+    printf.o \
+    spawn.o \
+    stat.o \
+    typo.o \
+    util.o
 	$(CC) $(ALL_LDFLAGS) $^ $(ALL_LDLIBS) -o $@
 
 sanitized: CFLAGS := -g $(WFLAGS) -fsanitize=address -fsanitize=undefined
diff --git a/color.c b/color.c
index a877ff7..82076cf 100644
--- a/color.c
+++ b/color.c
@@ -16,6 +16,7 @@
 
 #include "color.h"
 #include "bftw.h"
+#include "posix1e.h"
 #include "stat.h"
 #include "util.h"
 #include <assert.h>
diff --git a/eval.c b/eval.c
index 5b55b8d..37f8bf5 100644
--- a/eval.c
+++ b/eval.c
@@ -22,6 +22,7 @@
 #include "dstring.h"
 #include "exec.h"
 #include "mtab.h"
+#include "posix1e.h"
 #include "printf.h"
 #include "stat.h"
 #include "util.h"
diff --git a/posix1e.c b/posix1e.c
new file mode 100644
index 0000000..00bff10
--- /dev/null
+++ b/posix1e.c
@@ -0,0 +1,192 @@
+/****************************************************************************
+ * 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->at_flags & AT_SYMLINK_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
diff --git a/posix1e.h b/posix1e.h
new file mode 100644
index 0000000..da7c2b4
--- /dev/null
+++ b/posix1e.h
@@ -0,0 +1,33 @@
+/****************************************************************************
+ * 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.           *
+ ****************************************************************************/
+
+#ifndef BFS_POSIX1E_H
+#define BFS_POSIX1E_H
+
+#include "bftw.h"
+#include "util.h"
+
+/**
+ * Check if a file has a non-trvial Access Control List.
+ */
+bool bfs_check_acl(const struct BFTW *ftwbuf);
+
+/**
+ * Check if a file has a non-trvial capability set.
+ */
+bool bfs_check_capabilities(const struct BFTW *ftwbuf);
+
+#endif // BFS_POSIX1E_H
diff --git a/tests.sh b/tests.sh
index 0b2678d..5905d38 100755
--- a/tests.sh
+++ b/tests.sh
@@ -174,10 +174,10 @@ function make_rainbow() {
     touchp "$1/mh1"
     ln "$1/mh1" "$1/mh2"
     mkfifo "$1/pipe"
-    # XXX: block
-    # XXX: chardev
+    # TODO: block
+    # TODO: chardev
     ln -s nowhere "$1/broken"
-    # XXX: socket
+    # TODO: socket
     touchp "$1"/s{u,g,ug}id
     chmod u+s "$1"/su{,g}id
     chmod g+s "$1"/s{u,}gid
diff --git a/util.c b/util.c
index ba7b75e..b708527 100644
--- a/util.c
+++ b/util.c
@@ -30,14 +30,6 @@
 #include <sys/types.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_PARAM
 #	include <sys/param.h>
 #endif
@@ -385,163 +377,3 @@ int bfs_minor(dev_t dev) {
 	return dev & 0xFF;
 #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->at_flags & AT_SYMLINK_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
diff --git a/util.h b/util.h
index 4a9947c..2031c02 100644
--- a/util.h
+++ b/util.h
@@ -205,16 +205,4 @@ int bfs_major(dev_t dev);
  */
 int bfs_minor(dev_t dev);
 
-struct BFTW;
-
-/**
- * Check if a file has a non-trvial Access Control List.
- */
-bool bfs_check_acl(const struct BFTW *ftwbuf);
-
-/**
- * Check if a file has a non-trvial capability set.
- */
-bool bfs_check_capabilities(const struct BFTW *ftwbuf);
-
 #endif // BFS_UTIL_H