Merge pull request #96 from remicollet/issue-xattr

Issue xattr

smbclient.c

@@ -1663,10 +1663,15 @@ PHP_FUNCTION(smbclient_getxattr)
 	char *url, *name;
 	strsize_t url_len, name_len;
 	int retsize;
-	char values[1000];
+	int xattr_size;
 	zval *zstate;
 	smbc_getxattr_fn smbc_getxattr;
 	php_smbclient_state *state;
+#if PHP_MAJOR_VERSION >= 7
+	zend_string *svalues = NULL;
+#else
+	char *values = NULL;
+#endif
 
 	if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "rss", &zstate, &url, &url_len, &name, &name_len) == FAILURE) {
 		return;
@@ -1676,20 +1681,40 @@ PHP_FUNCTION(smbclient_getxattr)
 	if ((smbc_getxattr = smbc_getFunctionGetxattr(state->ctx)) == NULL) {
 		RETURN_FALSE;
 	}
-	/* TODO: 1000 chars should be enough for everyone...?
-	 * However, doing an initial blank call to determine the response size
-	 * seems wasteful, and vulnerable to a time-of-check, time-of-use
-	 * error. */
-	if ((retsize = smbc_getxattr(state->ctx, url, name, values, sizeof(values))) >= 0) {
-		if (retsize > sizeof(values)) {
-			retsize = sizeof(values);
-		}
+
+	xattr_size = smbc_getxattr(state->ctx, url, name, NULL, 0);
+
+	if (xattr_size < 0) {
+		goto fail;
+	}
+
+	if (xattr_size == 0) {
+		RETURN_EMPTY_STRING();
+	}
+
 #if PHP_MAJOR_VERSION >= 7
-		RETURN_STRINGL(values, retsize);
+	svalues = zend_string_alloc(xattr_size, 0);
+	retsize = smbc_getxattr(state->ctx, url, name, ZSTR_VAL(svalues), xattr_size + 1);
+	if (retsize > xattr_size) { /* time-of-check, time-of-use error */
+		retsize = xattr_size;
+	} else if (retsize < 0) {
+		zend_string_release(svalues);
+		goto fail;
+	}
+	RETURN_STR(svalues);
 #else
-		RETURN_STRINGL(values, retsize, 1);
+	values = emalloc(xattr_size + 1);
+	retsize = smbc_getxattr(state->ctx, url, name, values, xattr_size + 1);
+	if (retsize > xattr_size) { /* time-of-check, time-of-use error */
+		retsize = xattr_size;
+	} else if (retsize < 0) {
+		efree(values);
+		goto fail;
+	}
+	RETURN_STRINGL(values, retsize, 0);
 #endif
-	}
+
+fail:
 	hide_password(url, url_len);
 	switch (state->err = errno) {
 		case EINVAL: php_error(E_WARNING, "Couldn't get xattr for %s: library not initialized or incorrect parameter", url); break;