commit 84139cb2636cb22c285102eaa9b96e2e00e83a72 Author: George Kadianakis <desnacked@gmail.com> Date: Mon May 16 18:08:36 2011 +0200 Send SOCKS responses when CONNECT fails, and also treat our connection better. --- src/network.c | 54 ++++++++++++++++++++++++++++++++++++++---------------- 1 files changed, 38 insertions(+), 16 deletions(-) diff --git a/src/network.c b/src/network.c index 66b3f59..b0106de 100644 --- a/src/network.c +++ b/src/network.c @@ -341,27 +341,49 @@ output_event_cb(struct bufferevent *bev, short what, void *arg) conn_t *conn = arg; assert(bev == conn->output); - if (conn->flushing || (what & (BEV_EVENT_EOF))) { + /** + If we got the BEV_EVENT_ERROR flag *AND* we are in socks mode + *AND* we are in the ST_HAVE_ADDR state, chances are that we + failed connecting to the host requested by the CONNECT call. This + means that we should send a negative SOCKS reply back to the + client and terminate the connection. + */ + if (what & BEV_EVENT_ERROR) { + if ((conn->mode == LSN_SOCKS_CLIENT) && + (conn->socks_state) && + (socks_state_get_status(conn->socks_state) == ST_HAVE_ADDR)) { + dbg(("Connection failed\n")); + /* Enable EV_WRITE so that we can send the response. + Disable EV_READ so that we don't get more stuff from the client. */ + bufferevent_enable(conn->input, EV_WRITE); + bufferevent_disable(conn->input, EV_READ); + socks_send_reply(conn->socks_state, bufferevent_get_output(conn->input), + SOCKS5_REP_FAIL); + bufferevent_setcb(conn->input, NULL, + close_conn_on_flush, output_event_cb, conn); + return; + } + } + + /** + If the connection is terminating *OR* if we got a BEV_EVENT_ERROR + but we don't match the case above, we most probably have to close + this connection soon. + */ + if (conn->flushing || (what & (BEV_EVENT_EOF|BEV_EVENT_ERROR))) { printf("Got error: %s\n", evutil_socket_error_to_string(EVUTIL_SOCKET_ERROR())); error_or_eof(conn, bev, conn->input); return; } - /* ASN PROBABLY connect failed and we should send a "fail" SOCKS - response. (or maybe not. I should check all the cases where - BEV_EVENT_ERROR is waved) */ - if (what & BEV_EVENT_ERROR) { - /* assert(conn->socks_state) ? */ - if (conn->socks_state) { - if (socks_state_get_status(conn->socks_state) == ST_HAVE_ADDR) { - dbg(("Connection failed\n")); - bufferevent_enable(conn->input, EV_READ|EV_WRITE); - socks_send_reply(conn->socks_state, bufferevent_get_output(conn->input), - SOCKS5_REP_FAIL); - return; - } - } - } + + /** + If we got the BEV_EVENT_CONNECTED flag it means that a connection + request was succesfull and normally that should have been off a + CONNECT request by the SOCKS client. If that's the case we should + send a happy response to the client and switch to start serving + our pluggable transport protocol. + */ if (what & BEV_EVENT_CONNECTED) { /* woo, we're connected. Now the input buffer can start reading. */ conn->is_open = 1;