recursive_action: add depth param

chmod: match coreutils versus following links

archival/tar.c

@@ -301,7 +301,7 @@ static int exclude_file(const llist_t *excluded_files, const char *file)
 # endif
 
 static int writeFileToTarball(const char *fileName, struct stat *statbuf,
-							  void *userData)
+			void *userData, int depth)
 {
 	struct TarBallInfo *tbInfo = (struct TarBallInfo *) userData;
 	const char *header_name;
@@ -473,7 +473,7 @@ static int writeTarFile(const int tar_fd, const int verboseFlag,
 	/* Read the directory/files and iterate over them one at a time */
 	while (include) {
 		if (!recursive_action(include->data, TRUE, dereferenceFlag,
-				FALSE, writeFileToTarball, writeFileToTarball, &tbInfo))
+				FALSE, writeFileToTarball, writeFileToTarball, &tbInfo, 0))
 		{
 			errorFlag = TRUE;
 		}

coreutils/chmod.c

@@ -20,9 +20,9 @@
 #define OPT_VERBOSE (USE_DESKTOP(option_mask32 & 2) SKIP_DESKTOP(0))
 #define OPT_CHANGED (USE_DESKTOP(option_mask32 & 4) SKIP_DESKTOP(0))
 #define OPT_QUIET   (USE_DESKTOP(option_mask32 & 8) SKIP_DESKTOP(0))
-#define OPT_STR     ("-R" USE_DESKTOP("vcf"))
+#define OPT_STR     "R" USE_DESKTOP("vcf")
 
-/* TODO:
+/* coreutils:
  * chmod never changes the permissions of symbolic links; the chmod
  * system call cannot change their permissions. This is not a problem
  * since the permissions of symbolic links are never used.
@@ -31,19 +31,26 @@
  * symbolic links encountered during recursive directory traversals.
  */
 
-static int fileAction(const char *fileName, struct stat *statbuf, void* junk)
+static int fileAction(const char *fileName, struct stat *statbuf, void* junk, int depth)
 {
-	mode_t newmode = statbuf->st_mode;
+	mode_t newmode;
 
-	// TODO: match GNU behavior:
+	/* match coreutils behavior */
-	// if (depth > 0 && S_ISLNK(statbuf->st_mode)) return TRUE;
+	if (depth == 0) {
-	// if (depth == 0) follow link
+		/* statbuf holds lstat result, but we need stat (follow link) */
+		if (stat(fileName, statbuf))
+			goto err;
+	} else { /* depth > 0: skip links */
+		if (S_ISLNK(statbuf->st_mode))
+			return TRUE;
+	}
+	newmode = statbuf->st_mode;
 
 	if (!bb_parse_mode((char *)junk, &newmode))
 		bb_error_msg_and_die("invalid mode: %s", (char *)junk);
 
-	if (chmod(fileName, statbuf->st_mode) == 0) {
+	if (chmod(fileName, newmode) == 0) {
-		if (OPT_VERBOSE /* -v verbose? or -c changed? */
+		if (OPT_VERBOSE
 		 || (OPT_CHANGED && statbuf->st_mode != newmode)
 		) {
 			printf("mode of '%s' changed to %04o (%s)\n", fileName,
@@ -51,7 +58,8 @@ static int fileAction(const char *fileName, struct stat *statbuf, void* junk)
 		}
 		return TRUE;
 	}
-	if (!OPT_QUIET) /* not silent (-f)? */
+ err:
+	if (!OPT_QUIET)
 		bb_perror_msg("%s", fileName);
 	return FALSE;
 }
@@ -62,30 +70,33 @@ int chmod_main(int argc, char **argv)
 	char *arg, **argp;
 	char *smode;
 
-	/* Convert first encountered -r into a-r, -w into a-w etc */
+	/* Convert first encountered -r into ar, -w into aw etc
-	argp = argv + 1;
+	 * so that getopt would not eat it */
-	while ((arg = *argp)) {
+	argp = argv;
+	while ((arg = *++argp)) {
 		/* Mode spec must be the first arg (sans -R etc) */
 		/* (protect against mishandling e.g. "chmod 644 -r") */
-		if (arg[0] != '-')
+		if (arg[0] != '-') {
+			arg = NULL;
 			break;
+		}
 		/* An option. Not a -- or valid option? */
-		if (arg[1] && !strchr(OPT_STR, arg[1])) {
+		if (arg[1] && !strchr("-"OPT_STR, arg[1])) {
-			argp[0] = xasprintf("a%s", arg);
+			arg[0] = 'a';
 			break;
 		}
-		argp++;
 	}
-	/* "chmod -rzzz abc" will say "invalid mode: a-rzzz"!
-	 * It is easily fixable, but deemed not worth the code */
 
+	/* Paerse options */
 	opt_complementary = "-2";
-	getopt32(argc, argv, OPT_STR + 1); /* Reuse string */
+	getopt32(argc, argv, ("-"OPT_STR) + 1); /* Reuse string */
 	argv += optind;
 
-	smode = *argv++;
+	/* Restore option-like mode if needed */
+	if (arg) arg[0] = '-';
 
 	/* Ok, ready to do the deed now */
+	smode = *argv++;
 	do {
 		if (!recursive_action(*argv,
 				OPT_RECURSE,    // recurse
@@ -93,7 +104,8 @@ int chmod_main(int argc, char **argv)
 				FALSE,          // depth first
 				fileAction,     // file action
 				fileAction,     // dir action
-				smode)          // user data
+				smode,          // user data
+				0)              // depth
 		) {
 			retval = EXIT_FAILURE;
 		}
@@ -101,3 +113,45 @@ int chmod_main(int argc, char **argv)
 
 	return retval;
 }
+
+/*
+Security: chmod is too important and too subtle.
+This is a test script (busybox chmod versus coreutils).
+Run it in empty dir. Probably requires bash.
+
+#!/bin/sh
+function create() {
+    rm -rf $1; mkdir $1
+    (
+    cd $1 || exit 1
+    mkdir dir
+    >up
+    >file
+    >dir/file
+    ln -s dir linkdir
+    ln -s file linkfile
+    ln -s ../up dir/up
+    )
+}
+function test() {
+    (cd test1; $t1 $1)
+    (cd test2; $t2 $1)
+    (cd test1; ls -lR) >out1
+    (cd test2; ls -lR) >out2
+    echo "chmod $1" >out.diff
+    if ! diff -u out1 out2 >>out.diff; then exit 1; fi
+    mv out.diff out1.diff
+}
+t1="/tmp/busybox chmod"
+t2="/usr/bin/chmod"
+create test1; create test2
+test "a+w file"
+test "a-w dir"
+test "a+w linkfile"
+test "a-w linkdir"
+test "-R a+w file"
+test "-R a-w dir"
+test "-R a+w linkfile"
+test "-R a-w linkdir"
+test "a-r,a+x linkfile"
+*/

coreutils/chown.c

@@ -32,7 +32,7 @@ static int (*chown_func)(const char *, uid_t, gid_t) = chown;
  */
 
 static int fileAction(const char *fileName, struct stat *statbuf,
-		void ATTRIBUTE_UNUSED *junk)
+		void ATTRIBUTE_UNUSED *junk, int depth)
 {
 	// TODO: -H/-L/-P
 	// if (depth ... && S_ISLNK(statbuf->st_mode)) ....
@@ -75,7 +75,8 @@ int chown_main(int argc, char **argv)
 		*groupName++ = '\0';
 		gid = get_ug_id(groupName, bb_xgetgrnam);
 	}
-	if (--groupName != *argv) uid = get_ug_id(*argv, bb_xgetpwnam);
+	if (--groupName != *argv)
+		uid = get_ug_id(*argv, bb_xgetpwnam);
 	++argv;
 
 	/* Ok, ready to do the deed now */
@@ -86,7 +87,8 @@ int chown_main(int argc, char **argv)
 				FALSE,          // depth first
 				fileAction,     // file action
 				fileAction,     // dir action
-				NULL)           // user data
+				NULL,           // user data
+				0)              // depth 
 		) {
 			retval = EXIT_FAILURE;
 		}

coreutils/diff.c

@@ -1030,7 +1030,7 @@ static int dir_strcmp(const void *p1, const void *p2)
 /* This function adds a filename to dl, the directory listing. */
 
 static int add_to_dirlist(const char *filename,
-						  struct stat ATTRIBUTE_UNUSED * sb, void *userdata)
+		struct stat ATTRIBUTE_UNUSED * sb, void *userdata, int depth)
 {
 	dl_count++;
 	dl = xrealloc(dl, dl_count * sizeof(char *));
@@ -1067,7 +1067,7 @@ static char **get_dir(char *path)
 	/* Now fill dl with a listing. */
 	if (cmd_flags & FLAG_r)
 		recursive_action(path, TRUE, TRUE, FALSE, add_to_dirlist, NULL,
-						 userdata);
+						 userdata, 0);
 	else {
 		DIR *dp;
 		struct dirent *ep;
@@ -1076,7 +1076,7 @@ static char **get_dir(char *path)
 		while ((ep = readdir(dp))) {
 			if ((!strcmp(ep->d_name, "..")) || (!strcmp(ep->d_name, ".")))
 				continue;
-			add_to_dirlist(ep->d_name, NULL, NULL);
+			add_to_dirlist(ep->d_name, NULL, NULL, 0);
 		}
 		closedir(dp);
 	}

findutils/find.c

@@ -56,7 +56,7 @@ static int num_matches;
 static int exec_opt;
 #endif
 
-static int fileAction(const char *fileName, struct stat *statbuf, void* junk)
+static int fileAction(const char *fileName, struct stat *statbuf, void* junk, int depth)
 {
 #ifdef CONFIG_FEATURE_FIND_XDEV
 	if (S_ISDIR(statbuf->st_mode) && xdev_count) {
@@ -307,12 +307,12 @@ int find_main(int argc, char **argv)
 
 	if (firstopt == 1) {
 		if (!recursive_action(".", TRUE, dereference, FALSE, fileAction,
-					fileAction, NULL))
+					fileAction, NULL, 0))
 			status = EXIT_FAILURE;
 	} else {
 		for (i = 1; i < firstopt; i++) {
 			if (!recursive_action(argv[i], TRUE, dereference, FALSE, fileAction,
-						fileAction, NULL))
+						fileAction, NULL, 0))
 				status = EXIT_FAILURE;
 		}
 	}

findutils/grep.c

@@ -290,7 +290,7 @@ static void load_regexes_from_file(llist_t *fopt)
 }
 
 
-static int file_action_grep(const char *filename, struct stat *statbuf, void* matched)
+static int file_action_grep(const char *filename, struct stat *statbuf, void* matched, int depth)
 {
 	FILE *file = fopen(filename, "r");
 	if (file == NULL) {
@@ -315,7 +315,8 @@ static int grep_dir(const char *dir)
 		/* depthFirst= */ 1,
 		/* fileAction= */ file_action_grep,
 		/* dirAction= */ NULL,
-		/* userData= */ &matched);
+		/* userData= */ &matched,
+		/* depth= */ 0);
 	return matched;
 }
 

include/libbb.h

@@ -195,9 +195,9 @@ extern int remove_file(const char *path, int flags);
 extern int copy_file(const char *source, const char *dest, int flags);
 extern int recursive_action(const char *fileName, int recurse,
 	int followLinks, int depthFirst,
-	  int (*fileAction) (const char *fileName, struct stat* statbuf, void* userData),
+	int (*fileAction) (const char *fileName, struct stat* statbuf, void* userData, int depth),
-	  int (*dirAction) (const char *fileName, struct stat* statbuf, void* userData),
+	int (*dirAction) (const char *fileName, struct stat* statbuf, void* userData, int depth),
-	  void* userData);
+	void* userData, int depth);
 extern int device_open(const char *device, int mode);
 extern int get_console_fd(void);
 extern char *find_block_device(char *path);

libbb/recursive_action.c

@@ -11,7 +11,6 @@
 
 #undef DEBUG_RECURS_ACTION
 
-
 /*
  * Walk down all the directories under the specified
  * location, and do something (something specified
@@ -23,16 +22,23 @@
  * is so stinking huge.
  */
 
-static int true_action(const char *fileName, struct stat *statbuf, void* userData)
+static int true_action(const char *fileName, struct stat *statbuf, void* userData, int depth)
 {
 	return TRUE;
 }
 
+/*
+ * followLinks=0/1 differs mainly in handling of links to dirs.
+ * 0: lstat(statbuf). Calls fileAction on link name even if points to dir.
+ * 1: stat(statbuf). Calls dirAction and optionally recurse on link to dir.
+ */
+
 int recursive_action(const char *fileName,
 		int recurse, int followLinks, int depthFirst,
-		int (*fileAction) (const char *fileName, struct stat * statbuf, void* userData),
+		int (*fileAction)(const char *fileName, struct stat *statbuf, void* userData, int depth),
-		int (*dirAction) (const char *fileName, struct stat * statbuf, void* userData),
+		int (*dirAction)(const char *fileName, struct stat *statbuf, void* userData, int depth),
-		void* userData)
+		void* userData,
+		int depth)
 {
 	struct stat statbuf;
 	int status;
@@ -53,21 +59,23 @@ int recursive_action(const char *fileName,
 		return FALSE;
 	}
 
-	if (!followLinks && (S_ISLNK(statbuf.st_mode))) {
+	/* If S_ISLNK(m), then we know that !S_ISDIR(m).
-		return fileAction(fileName, &statbuf, userData);
+	 * Then we can skip checking first part: if it is true, then
+	 * (!dir) is also true! */
+	if ( /* (!followLinks && S_ISLNK(statbuf.st_mode)) || */
+	 !S_ISDIR(statbuf.st_mode)
+	) {
+		return fileAction(fileName, &statbuf, userData, depth);
 	}
 
+	/* It's a directory (or a link to one, and followLinks is set) */
+
 	if (!recurse) {
-		if (S_ISDIR(statbuf.st_mode)) {
+		return dirAction(fileName, &statbuf, userData, depth);
-			return dirAction(fileName, &statbuf, userData);
 	}
-	}
-
-	if (!S_ISDIR(statbuf.st_mode))
-		return fileAction(fileName, &statbuf, userData);
 
 	if (!depthFirst) {
-		status = dirAction(fileName, &statbuf, userData);
+		status = dirAction(fileName, &statbuf, userData, depth);
 		if (!status) {
 			bb_perror_msg("%s", fileName);
 			return FALSE;
@@ -88,14 +96,14 @@ int recursive_action(const char *fileName,
 		if (nextFile == NULL)
 			continue;
 		if (!recursive_action(nextFile, TRUE, followLinks, depthFirst,
-					fileAction, dirAction, userData)) {
+				fileAction, dirAction, userData, depth+1)) {
 			status = FALSE;
 		}
 		free(nextFile);
 	}
 	closedir(dir);
 	if (depthFirst) {
-		if (!dirAction(fileName, &statbuf, userData)) {
+		if (!dirAction(fileName, &statbuf, userData, depth)) {
 			bb_perror_msg("%s", fileName);
 			return FALSE;
 		}

modutils/insmod.c

@@ -801,7 +801,7 @@ static char *m_fullName;
 
 
 static int check_module_name_match(const char *filename, struct stat *statbuf,
-				void *userdata)
+				void *userdata, int depth)
 {
 	char *fullname = (char *) userdata;
 
@@ -4048,7 +4048,7 @@ int insmod_main( int argc, char **argv)
 			else
 				module_dir = real_module_dir;
 			recursive_action(module_dir, TRUE, FALSE, FALSE,
-					check_module_name_match, 0, m_fullName);
+					check_module_name_match, 0, m_fullName, 0);
 			free(tmdn);
 		}
 
@@ -4063,7 +4063,7 @@ int insmod_main( int argc, char **argv)
 			/* No module found under /lib/modules/`uname -r`, this
 			 * time cast the net a bit wider.  Search /lib/modules/ */
 			if (!recursive_action(module_dir, TRUE, FALSE, FALSE,
-						    check_module_name_match, 0, m_fullName)
+						    check_module_name_match, 0, m_fullName, 0)
 			) {
 				if (m_filename == 0
 				 || ((fp = fopen(m_filename, "r")) == NULL)