Node-ffi throws 'undefined symbol' error for C functions

Question

I'm trying to use redir in NodeJs using node-ffi.

Here's my redir.js :

const ref = require('ref');
const ffi = require('ffi');
const Struct = require('ref-struct');

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

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

var redir = ffi.Library('./redir', {
  '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' ] ],
});

I compiled by doing ./autogen.sh && ./configure && ./make and generate redir executable. I had to rename it to redir.so because node-ffi keeps putting .so in the end of the file

Here's what I get when I do node redir.js :

Error: Dynamic Symbol Retrieval Error: ./redir.so: undefined symbol: target_init
    at DynamicLibrary.get (/home/lz/redir-controller/node_modules/ffi/lib/dynamic_library.js:112:11)

It cannot locate the target_init function. I believe I did everything alright. Could it be a function signature error (I'm using the wrong types) or it menas that there is really no function with the name target_init ?

UPDATE:

I tried to compile it specifically into a shared library:

gcc -shared -fpic redir.c -o libredir.so

but the problem of not finding target_init persists

Answer 1

解决方案：从函数中删除static关键字:)