1 files changed, 616 insertions, 0 deletions

diff --git a/thirdparty/libwebsockets/core/pollfd.c b/thirdparty/libwebsockets/core/pollfd.c
new file mode 100644
index 0000000000..2a632ce8ec
--- /dev/null
+++ b/thirdparty/libwebsockets/core/pollfd.c
@@ -0,0 +1,616 @@
+/*
+ * 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 "core/private.h"
+
+int
+_lws_change_pollfd(struct lws *wsi, int _and, int _or, struct lws_pollargs *pa)
+{
+#if !defined(LWS_WITH_LIBUV) && !defined(LWS_WITH_LIBEV) && !defined(LWS_WITH_LIBEVENT)
+	volatile struct lws_context_per_thread *vpt;
+#endif
+	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)
+		return 0;
+
+	assert(wsi->position_in_fds_table == LWS_NO_FDS_POS ||
+	       wsi->position_in_fds_table >= 0);
+
+	if (wsi->position_in_fds_table == LWS_NO_FDS_POS)
+		return 0;
+
+	if (((volatile struct lws *)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
+		 */
+		((volatile struct lws *)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 < (int)pt->fds_count);
+
+#if !defined(LWS_WITH_LIBUV) && \
+    !defined(LWS_WITH_LIBEV) && \
+    !defined(LWS_WITH_LIBEVENT)
+	/*
+	 * This only applies when we use the default poll() event loop.
+	 *
+	 * BSD can revert pa->events at any time, when the kernel decides to
+	 * exit from poll().  We can't protect against it using locking.
+	 *
+	 * Therefore we must check first if the service thread is in poll()
+	 * wait; if so, we know we must be being called from a foreign thread,
+	 * and we must keep a strictly ordered list of changes we made instead
+	 * of trying to apply them, since when poll() exits, which may happen
+	 * at any time it would revert our changes.
+	 *
+	 * The plat code will apply them when it leaves the poll() wait
+	 * before doing anything else.
+	 */
+
+	vpt = (volatile struct lws_context_per_thread *)pt;
+
+	vpt->foreign_spinlock = 1;
+	lws_memory_barrier();
+
+	if (vpt->inside_poll) {
+		struct lws_foreign_thread_pollfd *ftp, **ftp1;
+		/*
+		 * We are certainly a foreign thread trying to change events
+		 * while the service thread is in the poll() wait.
+		 *
+		 * Create a list of changes to be applied after poll() exit,
+		 * instead of trying to apply them now.
+		 */
+		ftp = lws_malloc(sizeof(*ftp), "ftp");
+		if (!ftp) {
+			vpt->foreign_spinlock = 0;
+			lws_memory_barrier();
+			ret = -1;
+			goto bail;
+		}
+
+		ftp->_and = _and;
+		ftp->_or = _or;
+		ftp->fd_index = wsi->position_in_fds_table;
+		ftp->next = NULL;
+
+		/* place at END of list to maintain order */
+		ftp1 = (struct lws_foreign_thread_pollfd **)
+						&vpt->foreign_pfd_list;
+		while (*ftp1)
+			ftp1 = &((*ftp1)->next);
+
+		*ftp1 = ftp;
+		vpt->foreign_spinlock = 0;
+		lws_memory_barrier();
+		lws_cancel_service_pt(wsi);
+
+		return 0;
+	}
+
+	vpt->foreign_spinlock = 0;
+	lws_memory_barrier();
+#endif
+
+	pfd = &pt->fds[wsi->position_in_fds_table];
+	pa->fd = wsi->desc.sockfd;
+	lwsl_debug("%s: wsi %p: fd %d events %d -> %d\n", __func__, wsi, pa->fd, pfd->events, (pfd->events & ~_and) | _or);
+	pa->prev_events = pfd->events;
+	pa->events = pfd->events = (pfd->events & ~_and) | _or;
+
+	if (wsi->http2_substream)
+		return 0;
+
+	if (wsi->vhost &&
+	    wsi->vhost->protocols[0].callback(wsi,
+			    	    	      LWS_CALLBACK_CHANGE_MODE_POLL_FD,
+					      wsi->user_space, (void *)pa, 0)) {
+		ret = -1;
+		goto bail;
+	}
+
+	if (context->event_loop_ops->io) {
+		if (_and & LWS_POLLIN)
+			context->event_loop_ops->io(wsi,
+					LWS_EV_STOP | LWS_EV_READ);
+
+		if (_or & LWS_POLLIN)
+			context->event_loop_ops->io(wsi,
+					LWS_EV_START | LWS_EV_READ);
+
+		if (_and & LWS_POLLOUT)
+			context->event_loop_ops->io(wsi,
+					LWS_EV_STOP | LWS_EV_WRITE);
+
+		if (_or & LWS_POLLOUT)
+			context->event_loop_ops->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
+	 */
+	pa_events = pa->prev_events != pa->events;
+
+	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 && wsi->vhost) {
+			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
+/*
+ * Enable or disable listen sockets on this pt globally...
+ * it's modulated according to the pt having space for a new accept.
+ */
+static void
+lws_accept_modulation(struct lws_context *context,
+		      struct lws_context_per_thread *pt, int allow)
+{
+	struct lws_vhost *vh = context->vhost_list;
+	struct lws_pollargs pa1;
+
+	while (vh) {
+		if (vh->lserv_wsi) {
+			if (allow)
+				_lws_change_pollfd(vh->lserv_wsi,
+					   0, LWS_POLLIN, &pa1);
+			else
+				_lws_change_pollfd(vh->lserv_wsi,
+					   LWS_POLLIN, 0, &pa1);
+		}
+		vh = vh->vhost_next;
+	}
+}
+#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)
+	if (wsi->desc.sockfd - lws_plat_socket_offset() >= context->max_fds) {
+		lwsl_err("Socket fd %d is too high (%d) offset %d\n",
+			 wsi->desc.sockfd, context->max_fds, lws_plat_socket_offset());
+		return 1;
+	}
+#endif
+
+	assert(wsi);
+	assert(wsi->event_pipe || wsi->vhost);
+	assert(lws_socket_is_valid(wsi->desc.sockfd));
+
+	if (wsi->vhost &&
+	    wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_LOCK_POLL,
+					   wsi->user_space, (void *) &pa, 1))
+		return -1;
+
+	pt->count_conns++;
+	insert_wsi(context, wsi);
+	wsi->position_in_fds_table = pt->fds_count;
+
+	pt->fds[wsi->position_in_fds_table].fd = wsi->desc.sockfd;
+	pt->fds[wsi->position_in_fds_table].events = LWS_POLLIN;
+	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 &&
+	    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(context, pt, 0);
+#endif
+
+	if (wsi->vhost &&
+	    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 };
+	struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
+	struct lws *end_wsi;
+	int v;
+	int m, ret = 0;
+
+	if (wsi->parent_carries_io) {
+		lws_same_vh_protocol_remove(wsi);
+		return 0;
+	}
+
+#if !defined(_WIN32)
+	if (wsi->desc.sockfd - lws_plat_socket_offset() > context->max_fds) {
+		lwsl_err("fd %d too high (%d)\n", wsi->desc.sockfd,
+			 context->max_fds);
+		return 1;
+	}
+#endif
+
+	if (wsi->vhost &&
+	    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;
+	
+	/* these are the only valid possibilities for position_in_fds_table */
+	assert(m == LWS_NO_FDS_POS || (m >= 0 &&
+				       (unsigned int)m < pt->fds_count));
+
+	if (context->event_loop_ops->io)
+		context->event_loop_ops->io(wsi,
+				  LWS_EV_STOP | LWS_EV_READ | LWS_EV_WRITE |
+				  LWS_EV_PREPARE_DELETION);
+
+	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);
+
+	if (m != LWS_NO_FDS_POS) {
+
+		/* have the last guy take up the now vacant slot */
+		pt->fds[m] = pt->fds[pt->fds_count - 1];
+		/* this decrements pt->fds_count */
+		lws_plat_delete_socket_from_fds(context, wsi, m);
+		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 for 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 = LWS_NO_FDS_POS;
+	}
+
+	/* remove also from external POLL support via protocol 0 */
+	if (lws_socket_is_valid(wsi->desc.sockfd) && wsi->vhost &&
+	    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 */
+	    (unsigned int)pt->fds_count < context->fd_limit_per_thread - 1)
+		lws_accept_modulation(context, pt, 1);
+#endif
+
+	if (wsi->vhost &&
+	    wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_UNLOCK_POLL,
+					      wsi->user_space, (void *) &pa, 1))
+		ret = -1;
+
+	return ret;
+}
+
+int
+__lws_change_pollfd(struct lws *wsi, int _and, int _or)
+{
+	struct lws_context *context;
+	struct lws_pollargs pa;
+	int ret = 0;
+
+	if (!wsi || (!wsi->protocol && !wsi->event_pipe) ||
+	    wsi->position_in_fds_table == LWS_NO_FDS_POS)
+		return 0;
+
+	context = lws_get_context(wsi);
+	if (!context)
+		return 1;
+
+	if (wsi->vhost &&
+	    wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_LOCK_POLL,
+					      wsi->user_space, (void *) &pa, 0))
+		return -1;
+
+	ret = _lws_change_pollfd(wsi, _and, _or, &pa);
+	if (wsi->vhost &&
+	    wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_UNLOCK_POLL,
+					   wsi->user_space, (void *) &pa, 0))
+		ret = -1;
+
+	return ret;
+}
+
+int
+lws_change_pollfd(struct lws *wsi, int _and, int _or)
+{
+	struct lws_context_per_thread *pt;
+	int ret = 0;
+
+	pt = &wsi->context->pt[(int)wsi->tsi];
+
+	lws_pt_lock(pt, __func__);
+	ret = __lws_change_pollfd(wsi, _and, _or);
+	lws_pt_unlock(pt);
+
+	return ret;
+}
+
+LWS_VISIBLE int
+lws_callback_on_writable(struct lws *wsi)
+{
+	struct lws_context_per_thread *pt;
+	int n;
+
+	if (lwsi_state(wsi) == LRS_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
+
+
+	if (wsi->role_ops->callback_on_writable) {
+		if (wsi->role_ops->callback_on_writable(wsi))
+			return 1;
+		wsi = lws_get_network_wsi(wsi);
+	}
+
+	if (wsi->position_in_fds_table == LWS_NO_FDS_POS) {
+		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");
+	}
+
+	lws_vhost_lock(wsi->vhost);
+
+	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;
+
+	wsi->on_same_vh_list = 1;
+
+	lws_vhost_unlock(wsi->vhost);
+}
+
+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->vhost || !wsi->on_same_vh_list)
+		return;
+
+	lws_vhost_lock(wsi->vhost);
+
+	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;
+	wsi->on_same_vh_list = 0;
+
+	lws_vhost_unlock(wsi->vhost);
+}
+
+
+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;
+	int n;
+
+	if (!context)
+		return 0;
+
+	vhost = context->vhost_list;
+
+	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;
+}