fix segfault and add more sane api

README.md

@@ -199,21 +199,30 @@ Called when the mode of a path is being changed
 
 Called when the a new device file is being made.
 
-#### `ops.setxattr(path, name, buffer, length, offset, flags, cb)`
+#### `ops.setxattr(path, name, value, position, flags, cb)`
 
 Called when extended attributes is being set (see the extended docs for your platform).
-Currently you can read the attribute value being set in `buffer` at `offset`.
 
-#### `ops.getxattr(path, name, buffer, length, offset, cb)`
+Copy the `value` buffer somewhere to store it.
+
+The position argument is mostly a legacy argument only used on MacOS but see the getxattr docs
+on Mac for more on that (you probably don't need to use that).
+
+#### `ops.getxattr(path, name, position, cb)`
 
 Called when extended attributes is being read.
-Currently you have to write the result to the provided `buffer` at `offset`.
 
-#### `ops.listxattr(path, buffer, length, cb)`
+Return the extended attribute as the second argument to the callback (needs to be a buffer).
+If no attribute is stored return `null` as the second argument.
+
+The position argument is mostly a legacy argument only used on MacOS but see the getxattr docs
+on Mac for more on that (you probably don't need to use that).
+
+#### `ops.listxattr(path, cb)`
 
 Called when extended attributes of a path are being listed.
-`buffer` should be filled with the extended attribute names as *null-terminated* strings, one after the other, up to a total of `length` in length. (`ERANGE` should be passed to the callback if `length` is insufficient.)
+
-The size of buffer required to hold all the names should be passed to the callback either on success, or if the supplied `length` was zero.
+Return a list of strings of the names of the attributes you have stored as the second argument to the callback.
 
 #### `ops.removexattr(path, name, cb)`
 

fuse-native.c

@@ -434,7 +434,7 @@ FUSE_METHOD(readdir, 1, 2, (const char *path, void *buf, fuse_fill_dir_t filler,
 
 #ifdef __APPLE__
 
-FUSE_METHOD_VOID(setxattr, 6, 0, (const char *path, const char *name, const char *value, size_t size, int flags, uint32_t position), {
+FUSE_METHOD_VOID(setxattr, 5, 0, (const char *path, const char *name, const char *value, size_t size, int flags, uint32_t position), {
   l->path = path;
   l->name = name;
   l->value = value;
@@ -444,13 +444,12 @@ FUSE_METHOD_VOID(setxattr, 6, 0, (const char *path, const char *name, const char
 }, {
   napi_create_string_utf8(env, l->path, NAPI_AUTO_LENGTH, &(argv[2]));
   napi_create_string_utf8(env, l->name, NAPI_AUTO_LENGTH, &(argv[3]));
-  napi_create_string_utf8(env, l->value, NAPI_AUTO_LENGTH, &(argv[4]));
+  napi_create_external_buffer(env, l->size, (char *) l->value, &fin, NULL, &(argv[4]));
-  napi_create_uint32(env, l->size, &(argv[5]));
+  napi_create_uint32(env, l->position, &(argv[5]));
   napi_create_uint32(env, l->flags, &(argv[6]));
-  napi_create_uint32(env, l->position, &(argv[7]));
 })
 
-FUSE_METHOD_VOID(getxattr, 5, 0, (const char *path, const char *name, char *value, size_t size, uint32_t position), {
+FUSE_METHOD_VOID(getxattr, 4, 0, (const char *path, const char *name, char *value, size_t size, uint32_t position), {
   l->path = path;
   l->name = name;
   l->value = value;
@@ -459,9 +458,8 @@ FUSE_METHOD_VOID(getxattr, 5, 0, (const char *path, const char *name, char *valu
 }, {
   napi_create_string_utf8(env, l->path, NAPI_AUTO_LENGTH, &(argv[2]));
   napi_create_string_utf8(env, l->name, NAPI_AUTO_LENGTH, &(argv[3]));
-  napi_create_string_utf8(env, l->value, NAPI_AUTO_LENGTH, &(argv[4]));
+  napi_create_external_buffer(env, l->size, (char *) l->value, &fin, NULL, &(argv[4]));
-  napi_create_uint32(env, l->size, &(argv[5]));
+  napi_create_uint32(env, l->position, &(argv[5]));
-  napi_create_uint32(env, l->position, &(argv[6]));
 })
 
 #else
@@ -475,8 +473,8 @@ FUSE_METHOD_VOID(setxattr, 5, 0, (const char *path, const char *name, const char
 }, {
   napi_create_string_utf8(env, l->path, NAPI_AUTO_LENGTH, &(argv[2]));
   napi_create_string_utf8(env, l->name, NAPI_AUTO_LENGTH, &(argv[3]));
-  napi_create_string_utf8(env, l->value, NAPI_AUTO_LENGTH, &(argv[4]));
+  napi_create_external_buffer(env, l->size, (char *) l->value, &fin, NULL, &(argv[4]));
-  napi_create_uint32(env, l->size, &(argv[5]));
+  napi_create_uint32(env, 0, &(argv[5])); // normalize apis between mac and linux
   napi_create_uint32(env, l->flags, &(argv[6]));
 })
 
@@ -488,20 +486,19 @@ FUSE_METHOD_VOID(getxattr, 4, 0, (const char *path, const char *name, char *valu
 }, {
   napi_create_string_utf8(env, l->path, NAPI_AUTO_LENGTH, &(argv[2]));
   napi_create_string_utf8(env, l->name, NAPI_AUTO_LENGTH, &(argv[3]));
-  napi_create_string_utf8(env, l->value, NAPI_AUTO_LENGTH, &(argv[4]));
+  napi_create_external_buffer(env, l->size, (char *) l->value, &fin, NULL, &(argv[4]));
-  napi_create_uint32(env, l->size, &(argv[5]));
+  napi_create_uint32(env, 0, &(argv[5]));
 })
 
 #endif
 
-FUSE_METHOD_VOID(listxattr, 3,  0, (const char *path, char *list, size_t size), {
+FUSE_METHOD_VOID(listxattr, 2, 0, (const char *path, char *list, size_t size), {
   l->path = path;
   l->list = list;
   l->size = size;
 }, {
   napi_create_string_utf8(env, l->path, NAPI_AUTO_LENGTH, &(argv[2]));
   napi_create_external_buffer(env, l->size, l->list, &fin, NULL, &(argv[3]));
-  napi_create_uint32(env, l->size, &(argv[4]));
 })
 
 FUSE_METHOD_VOID(removexattr, 2, 0, (const char *path, const char *name), {

index.js

@@ -396,20 +396,42 @@ class Fuse extends Nanoresource {
     })
   }
 
-  _op_setxattr (signal, path, name, value, size, position, flags) {
+  _op_setxattr (signal, path, name, value, position, flags) {
-    this.ops.setxattr(path, name, value, size, position, flags, err => {
+    this.ops.setxattr(path, name, value, position, flags, err => {
       return signal(err)
     })
   }
 
-  _op_getxattr (signal, path, name, value, size, position) {
+  _op_getxattr (signal, path, name, valueBuf, position) {
-    this.ops.getxattr(path, name, value, size, position, err => {
+    this.ops.getxattr(path, name, position, (err, value) => {
+      if (!err) {
+        if (!value) return signal(IS_OSX ? -93 : -61)
+        value.copy(valueBuf)
+        return signal(value.length)
+      }
       return signal(err)
     })
   }
 
-  _op_listxattr (signal, path, list, size) {
+  _op_listxattr (signal, path, listBuf) {
-    this.ops.listxattr(path, list, size, err => {
+    this.ops.listxattr(path, (err, list) => {
+      if (list && !err) {
+        if (!listBuf.length) {
+          let size = 0
+          for (const name of list) size += Buffer.byteLength(name) + 1
+          size += 128 // fuse yells if we do not signal room for some mac stuff also
+          return signal(size)
+        }
+
+        let ptr = 0
+        for (const name of list) {
+          listBuf.write(name, ptr)
+          ptr += Buffer.byteLength(name)
+          listBuf[ptr++] = 0
+        }
+
+        return signal(ptr)
+      }
       return signal(err)
     })
   }