/* * libwebsockets - small server side websockets and web server implementation * * Copyright (C) 2010-2015 Andy Green * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation: * version 2.1 of the License. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, * MA 02110-1301 USA */ #include "private-libwebsockets.h" int insert_wsi_socket_into_fds(struct lws_context *context, struct lws *wsi) { struct lws_pollargs pa = { wsi->sock, LWS_POLLIN, 0 }; if (context->fds_count >= context->max_fds) { lwsl_err("Too many fds (%d)\n", context->max_fds); return 1; } #if !defined(_WIN32) && !defined(MBED_OPERATORS) if (wsi->sock >= context->max_fds) { lwsl_err("Socket fd %d is too high (%d)\n", wsi->sock, context->max_fds); return 1; } #endif assert(wsi); assert(lws_socket_is_valid(wsi->sock)); if (context->protocols[0].callback(wsi, LWS_CALLBACK_LOCK_POLL, wsi->user_space, (void *) &pa, 1)) return -1; insert_wsi(context, wsi); wsi->position_in_fds_table = context->fds_count; context->fds[context->fds_count].fd = wsi->sock; context->fds[context->fds_count].events = LWS_POLLIN; lws_plat_insert_socket_into_fds(context, wsi); /* external POLL support via protocol 0 */ if (context->protocols[0].callback(wsi, LWS_CALLBACK_ADD_POLL_FD, wsi->user_space, (void *) &pa, 0)) return -1; if (context->protocols[0].callback(wsi, LWS_CALLBACK_UNLOCK_POLL, wsi->user_space, (void *)&pa, 1)) return -1; return 0; } int remove_wsi_socket_from_fds(struct lws *wsi) { int m; struct lws *end_wsi; struct lws_pollargs pa = { wsi->sock, 0, 0 }; struct lws_context *context = wsi->context; lws_libev_io(wsi, LWS_EV_STOP | LWS_EV_READ | LWS_EV_WRITE); --context->fds_count; #if !defined(_WIN32) && !defined(MBED_OPERATORS) if (wsi->sock > context->max_fds) { lwsl_err("Socket fd %d too high (%d)\n", wsi->sock, context->max_fds); return 1; } #endif lwsl_info("%s: wsi=%p, sock=%d, fds pos=%d\n", __func__, wsi, wsi->sock, wsi->position_in_fds_table); if (context->protocols[0].callback(wsi, LWS_CALLBACK_LOCK_POLL, wsi->user_space, (void *)&pa, 1)) return -1; m = wsi->position_in_fds_table; /* replace the contents for this */ /* have the last guy take up the vacant slot */ context->fds[m] = context->fds[context->fds_count]; lws_plat_delete_socket_from_fds(context, wsi, m); /* * end guy's fds_lookup entry remains unchanged * (still same fd pointing to same wsi) */ /* end guy's "position in fds table" changed */ end_wsi = wsi_from_fd(context, context->fds[context->fds_count].fd); end_wsi->position_in_fds_table = m; /* deletion guy's lws_lookup entry needs nuking */ delete_from_fd(context, wsi->sock); /* removed wsi has no position any more */ wsi->position_in_fds_table = -1; /* remove also from external POLL support via protocol 0 */ if (lws_socket_is_valid(wsi->sock)) { if (context->protocols[0].callback(wsi, LWS_CALLBACK_DEL_POLL_FD, wsi->user_space, (void *) &pa, 0)) return -1; } if (context->protocols[0].callback(wsi, LWS_CALLBACK_UNLOCK_POLL, wsi->user_space, (void *) &pa, 1)) return -1; return 0; } int lws_change_pollfd(struct lws *wsi, int _and, int _or) { struct lws_context *context; int tid; int sampled_tid; struct lws_pollfd *pfd; struct lws_pollargs pa; int pa_events = 1; if (!wsi || !wsi->protocol || wsi->position_in_fds_table < 0) return 1; context = lws_get_context(wsi); if (!context) return 1; pfd = &context->fds[wsi->position_in_fds_table]; pa.fd = wsi->sock; if (context->protocols[0].callback(wsi, LWS_CALLBACK_LOCK_POLL, wsi->user_space, (void *) &pa, 0)) return -1; pa.prev_events = pfd->events; pa.events = pfd->events = (pfd->events & ~_and) | _or; if (context->protocols[0].callback(wsi, LWS_CALLBACK_CHANGE_MODE_POLL_FD, wsi->user_space, (void *) &pa, 0)) return -1; /* * if we changed something in this pollfd... * ... and we're running in a different thread context * than the service thread... * ... and the service thread is waiting ... * then cancel it to force a restart with our changed events */ #if LWS_POSIX pa_events = pa.prev_events != pa.events; #endif if (pa_events) { if (lws_plat_change_pollfd(context, wsi, pfd)) { lwsl_info("%s failed\n", __func__); return 1; } sampled_tid = context->service_tid; if (sampled_tid) { tid = context->protocols[0].callback(NULL, LWS_CALLBACK_GET_THREAD_ID, NULL, NULL, 0); if (tid == -1) return -1; if (tid != sampled_tid) lws_cancel_service(context); } } if (context->protocols[0].callback(wsi, LWS_CALLBACK_UNLOCK_POLL, wsi->user_space, (void *) &pa, 0)) return -1; return 0; } /** * lws_callback_on_writable() - Request a callback when this socket * becomes able to be written to without * blocking * * @wsi: Websocket connection instance to get callback for */ LWS_VISIBLE int lws_callback_on_writable(struct lws *wsi) { #ifdef LWS_USE_HTTP2 struct lws *network_wsi, *wsi2; int already; lwsl_info("%s: %p\n", __func__, wsi); if (wsi->mode != LWSCM_HTTP2_SERVING) goto network_sock; if (wsi->u.http2.requested_POLLOUT) { lwsl_info("already pending writable\n"); return 1; } if (wsi->u.http2.tx_credit <= 0) { /* * other side is not able to cope with us sending * anything so no matter if we have POLLOUT on our side. * * Delay waiting for our POLLOUT until peer indicates he has * space for more using tx window command in http2 layer */ lwsl_info("%s: %p: waiting_tx_credit (%d)\n", __func__, wsi, wsi->u.http2.tx_credit); wsi->u.http2.waiting_tx_credit = 1; return 0; } network_wsi = lws_http2_get_network_wsi(wsi); already = network_wsi->u.http2.requested_POLLOUT; /* mark everybody above him as requesting pollout */ wsi2 = wsi; while (wsi2) { wsi2->u.http2.requested_POLLOUT = 1; lwsl_info("mark %p pending writable\n", wsi2); wsi2 = wsi2->u.http2.parent_wsi; } /* for network action, act only on the network wsi */ wsi = network_wsi; if (already) return 1; network_sock: #endif if (lws_ext_cb_wsi_active_exts(wsi, LWS_EXT_CALLBACK_REQUEST_ON_WRITEABLE, NULL, 0)) return 1; if (wsi->position_in_fds_table < 0) { lwsl_err("%s: failed to find socket %d\n", __func__, wsi->sock); return -1; } if (lws_change_pollfd(wsi, 0, LWS_POLLOUT)) return -1; lws_libev_io(wsi, LWS_EV_START | LWS_EV_WRITE); return 1; } /** * lws_callback_on_writable_all_protocol() - Request a callback for * all connections using the given protocol when it * becomes possible to write to each socket without * blocking in turn. * * @context: lws_context * @protocol: Protocol whose connections will get callbacks */ LWS_VISIBLE int lws_callback_on_writable_all_protocol(const struct lws_context *context, const struct lws_protocols *protocol) { struct lws *wsi; int n; for (n = 0; n < context->fds_count; n++) { wsi = wsi_from_fd(context,context->fds[n].fd); if (!wsi) continue; if (wsi->protocol == protocol) lws_callback_on_writable(wsi); } return 0; }