节点ffi指向结构的指针 [英] Node ffi pointer to struct

问题描述

首先，我在这里问是因为在节点ffi中使用指针没有快速的答案，也没有关于结构的指针，这会有所帮助

这是我的节点ffi:

const struct_in_addr = Struct({
  's_addr': 'ulong',
});

const struct_sockaddr_in = Struct({
  'sin_family': 'short',
  'sin_port'  : 'ushort',
  'in_addr'   : struct_in_addr,
  'sin_zero'  : 'char',
});


var redir = ffi.Library('./libredir', {
  //'main'           : [ 'int' , [ 'int', 'char* []' ] ],
  //'parse_args'     : [ 'void', [ 'int', 'char* []' ] ],
  'target_init'    : [ 'int' , [ 'char *', 'int', [ struct_sockaddr_in, "pointer" ]] ],
  'target_connect' : [ 'int' , [ 'int', [ struct_sockaddr_in, "pointer" ] ] ],
  'client_accept'  : [ 'int' , [ 'int', [ struct_sockaddr_in, "pointer" ] ] ],
  'server_socket'  : [ 'int' , [ 'char *', 'int', 'int' ] ],
});

以下是target_init的签名:

Here's the signature of target_init as an example:

int target_init(char *addr, int port, struct sockaddr_in *target)

这就是我要得到的:

/home/lz/redir-controller/node_modules/ref/lib/ref.js:397
    throw new TypeError('could not determine a proper "type" from: ' + JSON.stringify(type))
    ^

TypeError: could not determine a proper "type" from: [null,"pointer"]
    at coerceType (/home/lz/redir-controller/node_modules/ref/lib/ref.js:397:11)
    at Array.map (<anonymous>)

我正在使用 https://github.com/troglobit/redir /blob/master/redir.c 并使用gcc -shared -fpic redir.c -o libredir.so

我怀疑这是struct_sockaddr_in的问题，但一切似乎都还不错.我什至尝试在 https://github中这样做.com/node-ffi/node-ffi/wiki/Node-FFI-Tutorial#structs ，方法是:

I suspect it's a problem with struct_sockaddr_in but everything seems ok. I even tried to do as in https://github.com/node-ffi/node-ffi/wiki/Node-FFI-Tutorial#structs by doing:

const _struct_sockaddr_in = Struct({
  'sin_family': 'short',
  'sin_port'  : 'ushort',
  'in_addr'   : struct_in_addr,
  'sin_zero'  : 'char',
});

struct_sockaddr_in = ref.refType(_struct_sockaddr_in);

但是现在我得到了

TypeError: could not determine a proper "type" from: [{"indirection":2,"name":"StructType*"},"pointer"]

推荐答案

我不知道'pointer'的来源，但后续工作有效:

I don't know where I took 'pointer' from, but the followin works:

const struct_in_addr = Struct({
  's_addr': 'ulong',
});

const _struct_sockaddr_in = Struct({
  'sin_family': 'short',
  'sin_port'  : 'ushort',
  'in_addr'   : struct_in_addr,
  'sin_zero'  : 'char',
});

struct_sockaddr_in = ref.refType(_struct_sockaddr_in);

const redir = ffi.Library('./libredir', {
  //'main'           : [ 'int' , [ 'int', 'char* []' ] ],
  //'parse_args'     : [ 'void', [ 'int', 'char* []' ] ],
  'target_init'    : [ 'int' , [ 'char *', 'int', struct_sockaddr_in ] ],
  'target_connect' : [ 'int' , [ 'int',  struct_sockaddr_in ] ],
  'client_accept'  : [ 'int' , [ 'int',  struct_sockaddr_in ] ],
  'server_socket'  : [ 'int' , [ 'char *', 'int', 'int' ] ],
});

这篇关于节点ffi指向结构的指针的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！