/* * libwebsockets - small server side websockets and web server implementation * * Copyright (C) 2010-2017 Andy Green <andy@warmcat.com> * * 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 _lws_change_pollfd(struct lws *wsi, int _and, int _or, struct lws_pollargs *pa) { struct lws_context_per_thread *pt; struct lws_context *context; int ret = 0, pa_events = 1; struct lws_pollfd *pfd; int sampled_tid, tid; if (!wsi || wsi->position_in_fds_table < 0) return 0; if (wsi->handling_pollout && !_and && _or == LWS_POLLOUT) { /* * Happening alongside service thread handling POLLOUT. * The danger is when he is finished, he will disable POLLOUT, * countermanding what we changed here. * * Instead of changing the fds, inform the service thread * what happened, and ask it to leave POLLOUT active on exit */ wsi->leave_pollout_active = 1; /* * by definition service thread is not in poll wait, so no need * to cancel service */ lwsl_debug("%s: using leave_pollout_active\n", __func__); return 0; } context = wsi->context; pt = &context->pt[(int)wsi->tsi]; assert(wsi->position_in_fds_table >= 0 && wsi->position_in_fds_table < pt->fds_count); pfd = &pt->fds[wsi->position_in_fds_table]; pa->fd = wsi->desc.sockfd; pa->prev_events = pfd->events; pa->events = pfd->events = (pfd->events & ~_and) | _or; if (wsi->http2_substream) return 0; if (wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_CHANGE_MODE_POLL_FD, wsi->user_space, (void *)pa, 0)) { ret = -1; goto bail; } if (_and & LWS_POLLIN) { lws_libev_io(wsi, LWS_EV_STOP | LWS_EV_READ); lws_libuv_io(wsi, LWS_EV_STOP | LWS_EV_READ); lws_libevent_io(wsi, LWS_EV_STOP | LWS_EV_READ); } if (_or & LWS_POLLIN) { lws_libev_io(wsi, LWS_EV_START | LWS_EV_READ); lws_libuv_io(wsi, LWS_EV_START | LWS_EV_READ); lws_libevent_io(wsi, LWS_EV_START | LWS_EV_READ); } if (_and & LWS_POLLOUT) { lws_libev_io(wsi, LWS_EV_STOP | LWS_EV_WRITE); lws_libuv_io(wsi, LWS_EV_STOP | LWS_EV_WRITE); lws_libevent_io(wsi, LWS_EV_STOP | LWS_EV_WRITE); } if (_or & LWS_POLLOUT) { lws_libev_io(wsi, LWS_EV_START | LWS_EV_WRITE); lws_libuv_io(wsi, LWS_EV_START | LWS_EV_WRITE); lws_libevent_io(wsi, LWS_EV_START | LWS_EV_WRITE); } /* * 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__); ret = -1; goto bail; } sampled_tid = context->service_tid; if (sampled_tid) { tid = wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_GET_THREAD_ID, NULL, NULL, 0); if (tid == -1) { ret = -1; goto bail; } if (tid != sampled_tid) lws_cancel_service_pt(wsi); } } bail: return ret; } #ifndef LWS_NO_SERVER static void lws_accept_modulation(struct lws_context_per_thread *pt, int allow) { // multithread listen seems broken #if 0 struct lws_vhost *vh = context->vhost_list; struct lws_pollargs pa1; while (vh) { if (allow) _lws_change_pollfd(pt->wsi_listening, 0, LWS_POLLIN, &pa1); else _lws_change_pollfd(pt->wsi_listening, LWS_POLLIN, 0, &pa1); vh = vh->vhost_next; } #endif } #endif int insert_wsi_socket_into_fds(struct lws_context *context, struct lws *wsi) { struct lws_pollargs pa = { wsi->desc.sockfd, LWS_POLLIN, 0 }; struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi]; int ret = 0; lwsl_debug("%s: %p: tsi=%d, sock=%d, pos-in-fds=%d\n", __func__, wsi, wsi->tsi, wsi->desc.sockfd, pt->fds_count); if ((unsigned int)pt->fds_count >= context->fd_limit_per_thread) { lwsl_err("Too many fds (%d vs %d)\n", context->max_fds, context->fd_limit_per_thread ); return 1; } #if !defined(_WIN32) && !defined(LWS_WITH_ESP8266) if (wsi->desc.sockfd >= context->max_fds) { lwsl_err("Socket fd %d is too high (%d)\n", wsi->desc.sockfd, context->max_fds); return 1; } #endif assert(wsi); assert(wsi->vhost); assert(lws_socket_is_valid(wsi->desc.sockfd)); if (wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_LOCK_POLL, wsi->user_space, (void *) &pa, 1)) return -1; lws_pt_lock(pt); pt->count_conns++; insert_wsi(context, wsi); #if defined(LWS_WITH_ESP8266) if (wsi->position_in_fds_table == -1) #endif wsi->position_in_fds_table = pt->fds_count; pt->fds[wsi->position_in_fds_table].fd = wsi->desc.sockfd; #if LWS_POSIX pt->fds[wsi->position_in_fds_table].events = LWS_POLLIN; #else pt->fds[wsi->position_in_fds_table].events = 0; #endif pa.events = pt->fds[pt->fds_count].events; lws_plat_insert_socket_into_fds(context, wsi); /* external POLL support via protocol 0 */ if (wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_ADD_POLL_FD, wsi->user_space, (void *) &pa, 0)) ret = -1; #ifndef LWS_NO_SERVER /* if no more room, defeat accepts on this thread */ if ((unsigned int)pt->fds_count == context->fd_limit_per_thread - 1) lws_accept_modulation(pt, 0); #endif lws_pt_unlock(pt); if (wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_UNLOCK_POLL, wsi->user_space, (void *)&pa, 1)) ret = -1; return ret; } int remove_wsi_socket_from_fds(struct lws *wsi) { struct lws_context *context = wsi->context; struct lws_pollargs pa = { wsi->desc.sockfd, 0, 0 }; #if !defined(LWS_WITH_ESP8266) struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi]; struct lws *end_wsi; int v; #endif int m, ret = 0; if (wsi->parent_carries_io) { lws_same_vh_protocol_remove(wsi); return 0; } #if !defined(_WIN32) && !defined(LWS_WITH_ESP8266) if (wsi->desc.sockfd > context->max_fds) { lwsl_err("fd %d too high (%d)\n", wsi->desc.sockfd, context->max_fds); return 1; } #endif if (wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_LOCK_POLL, wsi->user_space, (void *)&pa, 1)) return -1; lws_same_vh_protocol_remove(wsi); /* the guy who is to be deleted's slot index in pt->fds */ m = wsi->position_in_fds_table; #if !defined(LWS_WITH_ESP8266) lws_libev_io(wsi, LWS_EV_STOP | LWS_EV_READ | LWS_EV_WRITE | LWS_EV_PREPARE_DELETION); lws_libuv_io(wsi, LWS_EV_STOP | LWS_EV_READ | LWS_EV_WRITE | LWS_EV_PREPARE_DELETION); lws_pt_lock(pt); lwsl_debug("%s: wsi=%p, sock=%d, fds pos=%d, end guy pos=%d, endfd=%d\n", __func__, wsi, wsi->desc.sockfd, wsi->position_in_fds_table, pt->fds_count, pt->fds[pt->fds_count].fd); /* have the last guy take up the now vacant slot */ pt->fds[m] = pt->fds[pt->fds_count - 1]; #endif /* this decrements pt->fds_count */ lws_plat_delete_socket_from_fds(context, wsi, m); #if !defined(LWS_WITH_ESP8266) v = (int) pt->fds[m].fd; /* end guy's "position in fds table" is now the deletion guy's old one */ end_wsi = wsi_from_fd(context, v); if (!end_wsi) { lwsl_err("no wsi found for sock fd %d at pos %d, pt->fds_count=%d\n", (int)pt->fds[m].fd, m, pt->fds_count); assert(0); } else end_wsi->position_in_fds_table = m; /* deletion guy's lws_lookup entry needs nuking */ delete_from_fd(context, wsi->desc.sockfd); /* 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->desc.sockfd)) if (wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_DEL_POLL_FD, wsi->user_space, (void *) &pa, 0)) ret = -1; #ifndef LWS_NO_SERVER if (!context->being_destroyed) /* if this made some room, accept connects on this thread */ if ((unsigned int)pt->fds_count < context->fd_limit_per_thread - 1) lws_accept_modulation(pt, 1); #endif lws_pt_unlock(pt); if (wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_UNLOCK_POLL, wsi->user_space, (void *) &pa, 1)) ret = -1; #endif return ret; } int lws_change_pollfd(struct lws *wsi, int _and, int _or) { struct lws_context_per_thread *pt; struct lws_context *context; struct lws_pollargs pa; int ret = 0; if (!wsi || !wsi->protocol || wsi->position_in_fds_table < 0) return 1; context = lws_get_context(wsi); if (!context) return 1; if (wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_LOCK_POLL, wsi->user_space, (void *) &pa, 0)) return -1; pt = &context->pt[(int)wsi->tsi]; lws_pt_lock(pt); ret = _lws_change_pollfd(wsi, _and, _or, &pa); lws_pt_unlock(pt); if (wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_UNLOCK_POLL, wsi->user_space, (void *) &pa, 0)) ret = -1; return ret; } LWS_VISIBLE int lws_callback_on_writable(struct lws *wsi) { struct lws_context_per_thread *pt; #ifdef LWS_WITH_HTTP2 struct lws *network_wsi, *wsi2; int already; #endif int n; if (wsi->state == LWSS_SHUTDOWN) return 0; if (wsi->socket_is_permanently_unusable) return 0; pt = &wsi->context->pt[(int)wsi->tsi]; if (wsi->parent_carries_io) { #if defined(LWS_WITH_STATS) if (!wsi->active_writable_req_us) { wsi->active_writable_req_us = time_in_microseconds(); lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_C_WRITEABLE_CB_EFF_REQ, 1); } #endif n = lws_callback_on_writable(wsi->parent); if (n < 0) return n; wsi->parent_pending_cb_on_writable = 1; return 1; } lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_C_WRITEABLE_CB_REQ, 1); #if defined(LWS_WITH_STATS) if (!wsi->active_writable_req_us) { wsi->active_writable_req_us = time_in_microseconds(); lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_C_WRITEABLE_CB_EFF_REQ, 1); } #endif #ifdef LWS_WITH_HTTP2 lwsl_info("%s: %p\n", __func__, wsi); if (wsi->mode != LWSCM_HTTP2_SERVING) goto network_sock; if (wsi->u.h2.requested_POLLOUT) { lwsl_info("already pending writable\n"); return 1; } /* is this for DATA or for control messages? */ if (wsi->upgraded_to_http2 && !wsi->u.h2.h2n->pps && !lws_h2_tx_cr_get(wsi)) { /* * other side is not able to cope with us sending DATA * anything so no matter if we have POLLOUT on our side if it's * DATA we want to send. * * Delay waiting for our POLLOUT until peer indicates he has * space for more using tx window command in http2 layer */ lwsl_notice("%s: %p: skint (%d)\n", __func__, wsi, wsi->u.h2.tx_cr); wsi->u.h2.skint = 1; return 0; } wsi->u.h2.skint = 0; network_wsi = lws_get_network_wsi(wsi); already = network_wsi->u.h2.requested_POLLOUT; /* mark everybody above him as requesting pollout */ wsi2 = wsi; while (wsi2) { wsi2->u.h2.requested_POLLOUT = 1; lwsl_info("mark %p pending writable\n", wsi2); wsi2 = wsi2->u.h2.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_active(wsi, LWS_EXT_CB_REQUEST_ON_WRITEABLE, NULL, 0)) return 1; if (wsi->position_in_fds_table < 0) { lwsl_debug("%s: failed to find socket %d\n", __func__, wsi->desc.sockfd); return -1; } if (lws_change_pollfd(wsi, 0, LWS_POLLOUT)) return -1; return 1; } /* * stitch protocol choice into the vh protocol linked list * We always insert ourselves at the start of the list * * X <-> B * X <-> pAn <-> pB * * Illegal to attach more than once without detach inbetween */ void lws_same_vh_protocol_insert(struct lws *wsi, int n) { if (wsi->same_vh_protocol_prev || wsi->same_vh_protocol_next) { lws_same_vh_protocol_remove(wsi); lwsl_notice("Attempted to attach wsi twice to same vh prot\n"); } wsi->same_vh_protocol_prev = &wsi->vhost->same_vh_protocol_list[n]; /* old first guy is our next */ wsi->same_vh_protocol_next = wsi->vhost->same_vh_protocol_list[n]; /* we become the new first guy */ wsi->vhost->same_vh_protocol_list[n] = wsi; if (wsi->same_vh_protocol_next) /* old first guy points back to us now */ wsi->same_vh_protocol_next->same_vh_protocol_prev = &wsi->same_vh_protocol_next; } void lws_same_vh_protocol_remove(struct lws *wsi) { /* * detach ourselves from vh protocol list if we're on one * A -> B -> C * A -> C , or, B -> C, or A -> B * * OK to call on already-detached wsi */ lwsl_info("%s: removing same prot wsi %p\n", __func__, wsi); if (wsi->same_vh_protocol_prev) { assert (*(wsi->same_vh_protocol_prev) == wsi); lwsl_info("have prev %p, setting him to our next %p\n", wsi->same_vh_protocol_prev, wsi->same_vh_protocol_next); /* guy who pointed to us should point to our next */ *(wsi->same_vh_protocol_prev) = wsi->same_vh_protocol_next; } /* our next should point back to our prev */ if (wsi->same_vh_protocol_next) { wsi->same_vh_protocol_next->same_vh_protocol_prev = wsi->same_vh_protocol_prev; } wsi->same_vh_protocol_prev = NULL; wsi->same_vh_protocol_next = NULL; } LWS_VISIBLE int lws_callback_on_writable_all_protocol_vhost(const struct lws_vhost *vhost, const struct lws_protocols *protocol) { struct lws *wsi; if (protocol < vhost->protocols || protocol >= (vhost->protocols + vhost->count_protocols)) { lwsl_err("%s: protocol %p is not from vhost %p (%p - %p)\n", __func__, protocol, vhost->protocols, vhost, (vhost->protocols + vhost->count_protocols)); return -1; } wsi = vhost->same_vh_protocol_list[protocol - vhost->protocols]; while (wsi) { assert(wsi->protocol == protocol); assert(*wsi->same_vh_protocol_prev == wsi); if (wsi->same_vh_protocol_next) assert(wsi->same_vh_protocol_next->same_vh_protocol_prev == &wsi->same_vh_protocol_next); lws_callback_on_writable(wsi); wsi = wsi->same_vh_protocol_next; } return 0; } LWS_VISIBLE int lws_callback_on_writable_all_protocol(const struct lws_context *context, const struct lws_protocols *protocol) { struct lws_vhost *vhost = context->vhost_list; int n; while (vhost) { for (n = 0; n < vhost->count_protocols; n++) if (protocol->callback == vhost->protocols[n].callback && !strcmp(protocol->name, vhost->protocols[n].name)) break; if (n != vhost->count_protocols) lws_callback_on_writable_all_protocol_vhost( vhost, &vhost->protocols[n]); vhost = vhost->vhost_next; } return 0; }