diff --git a/src/ws.c b/src/ws.c index 83de065..2a97c96 100644 --- a/src/ws.c +++ b/src/ws.c @@ -1,9 +1,14 @@ #include #include "error.h" +#include "util.h" #include "win.h" #include "ws.h" +#ifndef SIO_BSP_HANDLE_POLL +#define SIO_BSP_HANDLE_POLL 0x4800001D +#endif + #ifndef SIO_BASE_HANDLE #define SIO_BASE_HANDLE 0x48000022 #endif @@ -19,20 +24,54 @@ int ws_global_init(void) { return 0; } -SOCKET ws_get_base_socket(SOCKET socket) { - SOCKET base_socket; +static inline SOCKET ws__ioctl_get_bsp_socket(SOCKET socket, DWORD ioctl) { + SOCKET bsp_socket; DWORD bytes; if (WSAIoctl(socket, - SIO_BASE_HANDLE, + ioctl, NULL, 0, - &base_socket, - sizeof base_socket, + &bsp_socket, + sizeof bsp_socket, &bytes, NULL, - NULL) == SOCKET_ERROR) - return_map_error(INVALID_SOCKET); - - return base_socket; + NULL) != SOCKET_ERROR) + return bsp_socket; + else + return INVALID_SOCKET; +} + +SOCKET ws_get_base_socket(SOCKET socket) { + SOCKET base_socket; + DWORD error; + + for (;;) { + base_socket = ws__ioctl_get_bsp_socket(socket, SIO_BASE_HANDLE); + if (base_socket != INVALID_SOCKET) + return base_socket; + + error = GetLastError(); + if (error == WSAENOTSOCK) + return_set_error(INVALID_SOCKET, error); + + /* clang-format off */ + /* Even though Microsoft documentation clearly states that LSPs should + * never intercept the `SIO_BASE_HANDLE` ioctl [1], Komodia based LSPs do + * so anyway, breaking it, with the apparent intention of preventing LSP + * bypass [2]. Fortunately they don't handle `SIO_BSP_HANDLE_POLL`, which + * we can use to obtain the socket associated with the next protocol chain + * entry. If this succeeds, loop around and call `SIO_BASE_HANDLE` again + * with the retrieved BSP socket to be sure that we actually got all the + * way to the base. + * [1] https://docs.microsoft.com/en-us/windows/win32/winsock/winsock-ioctls + * [2] https://www.komodia.com/newwiki/index.php?title=Komodia%27s_Redirector_bug_fixes#Version_2.2.2.6 + */ + /* clang-format on */ + base_socket = ws__ioctl_get_bsp_socket(socket, SIO_BSP_HANDLE_POLL); + if (base_socket != INVALID_SOCKET && base_socket != socket) + socket = base_socket; + else + return_set_error(INVALID_SOCKET, error); + } }