lib: introduce socket library

Introduce a new socket module which provides bindings for the BSD sockets
API to ucode scripts.

Example usage:

    import * as socket from 'socket';

    let sk = socket.create(socket.AF_INET, socket.SOCK_STREAM);
    sk.connect("192.168.1.1", 80);
    sk.send("GET / HTTP/1.0\r\n\r\n");
    print(sk.recv(4096));
    sk.close();

Signed-off-by: Jo-Philipp Wich <[email protected]>

CMakeLists.txt

@@ -60,6 +60,7 @@ option(RESOLV_SUPPORT "NS resolve plugin support" ON)
 option(STRUCT_SUPPORT "Struct plugin support" ON)
 option(ULOOP_SUPPORT "Uloop plugin support" ${DEFAULT_ULOOP_SUPPORT})
 option(LOG_SUPPORT "Log plugin support" ON)
+option(SOCKET_SUPPORT "Socket plugin support" ON)
 
 set(LIB_SEARCH_PATH "${CMAKE_INSTALL_PREFIX}/lib/ucode/*.so:${CMAKE_INSTALL_PREFIX}/share/ucode/*.uc:./*.so:./*.uc" CACHE STRING "Default library search path")
 string(REPLACE ":" "\", \"" LIB_SEARCH_DEFINE "${LIB_SEARCH_PATH}")
@@ -266,6 +267,13 @@ if(LOG_SUPPORT)
   endif()
 endif()
 
+if(SOCKET_SUPPORT)
+  set(LIBRARIES ${LIBRARIES} socket_lib)
+  add_library(socket_lib MODULE lib/socket.c)
+  set_target_properties(socket_lib PROPERTIES OUTPUT_NAME socket PREFIX "")
+  target_link_options(socket_lib PRIVATE ${UCODE_MODULE_LINK_OPTIONS})
+endif()
+
 if(UNIT_TESTING)
   enable_testing()
   add_definitions(-DUNIT_TESTING)