fixes #2 Websocket transport

This is a rather large changeset -- it fundamentally adds websocket
transport, but as part of this changeset we added a generic framework
for both HTTP and websocket.  We also made some supporting changes to
the core, such as changing the way timeouts work for AIOs and adding
additional state keeping for AIOs, and adding a common framework for
deferred finalization (to avoid certain kinds of circular deadlocks
during resource cleanup).  We also invented a new initialization framework
so that we can avoid wiring in knowledge about them into the master
initialization framework.

The HTTP framework is not yet complete, but it is good enough for simple
static serving and building additional services on top of -- including
websocket.  We expect both websocket and HTTP support to evolve
considerably, and so these are not part of the public API yet.

Property support for the websocket transport (in particular address
properties) is still missing, as is support for TLS.

The websocket transport here is a bit more robust than the original
nanomsg implementation, as it supports multiple sockets listening at
the same port sharing the same HTTP server instance, discriminating
between them based on URI (and possibly the virtual host).

Websocket is enabled by default at present, and work to conditionalize
HTTP and websocket further (to minimize bloat) is still pending.

1 files changed, 533 insertions, 0 deletions

diff --git a/src/transport/ws/websocket.c b/src/transport/ws/websocket.c
new file mode 100644
index 00000000..8a73bcfb
--- /dev/null
+++ b/src/transport/ws/websocket.c
@@ -0,0 +1,533 @@
+//
+// Copyright 2017 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2017 Capitar IT Group BV <info@capitar.com>
+//
+// This software is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "core/nng_impl.h"
+#include "supplemental/websocket/websocket.h"
+
+typedef struct ws_ep   ws_ep;
+typedef struct ws_pipe ws_pipe;
+
+struct ws_ep {
+	int              mode; // NNI_EP_MODE_DIAL or NNI_EP_MODE_LISTEN
+	char *           addr;
+	uint16_t         lproto; // local protocol
+	uint16_t         rproto; // remote protocol
+	size_t           rcvmax;
+	char *           protoname;
+	nni_list         aios;
+	nni_mtx          mtx;
+	nni_aio *        connaio;
+	nni_aio *        accaio;
+	nni_ws_listener *listener;
+	nni_ws_dialer *  dialer;
+};
+
+struct ws_pipe {
+	int      mode; // NNI_EP_MODE_DIAL or NNI_EP_MODE_LISTEN
+	nni_mtx  mtx;
+	size_t   rcvmax; // inherited from EP
+	bool     closed;
+	uint16_t rproto;
+	uint16_t lproto;
+	nni_aio *user_txaio;
+	nni_aio *user_rxaio;
+	nni_aio *txaio;
+	nni_aio *rxaio;
+	nni_ws * ws;
+};
+
+static void
+ws_pipe_send_cb(void *arg)
+{
+	ws_pipe *p = arg;
+	nni_aio *taio;
+	nni_aio *uaio;
+
+	nni_mtx_lock(&p->mtx);
+	taio          = p->txaio;
+	uaio          = p->user_txaio;
+	p->user_txaio = NULL;
+
+	if (uaio != NULL) {
+		int rv;
+		if ((rv = nni_aio_result(taio)) != 0) {
+			nni_aio_finish_error(uaio, rv);
+		} else {
+			nni_aio_finish(uaio, 0, 0);
+		}
+	}
+	nni_mtx_unlock(&p->mtx);
+}
+
+static void
+ws_pipe_recv_cb(void *arg)
+{
+	ws_pipe *p    = arg;
+	nni_aio *raio = p->rxaio;
+	nni_aio *uaio;
+	int      rv;
+
+	nni_mtx_lock(&p->mtx);
+	uaio          = p->user_rxaio;
+	p->user_rxaio = NULL;
+	if ((rv = nni_aio_result(raio)) != 0) {
+		if (uaio != NULL) {
+			nni_aio_finish_error(uaio, rv);
+		}
+	} else {
+		nni_msg *msg = nni_aio_get_msg(raio);
+		if (uaio != NULL) {
+			nni_aio_finish_msg(uaio, msg);
+		} else {
+			nni_msg_free(msg);
+		}
+	}
+	nni_mtx_unlock(&p->mtx);
+}
+
+static void
+ws_pipe_recv_cancel(nni_aio *aio, int rv)
+{
+	ws_pipe *p = aio->a_prov_data;
+	nni_mtx_lock(&p->mtx);
+	if (p->user_rxaio != aio) {
+		nni_mtx_unlock(&p->mtx);
+		return;
+	}
+	nni_aio_cancel(p->rxaio, rv);
+	nni_mtx_unlock(&p->mtx);
+}
+
+static void
+ws_pipe_recv(void *arg, nni_aio *aio)
+{
+	ws_pipe *p = arg;
+
+	nni_mtx_lock(&p->mtx);
+	if (nni_aio_start(aio, ws_pipe_recv_cancel, p) != 0) {
+		nni_mtx_unlock(&p->mtx);
+		return;
+	}
+	p->user_rxaio = aio;
+
+	nni_ws_recv_msg(p->ws, p->rxaio);
+	nni_mtx_unlock(&p->mtx);
+}
+
+static void
+ws_pipe_send_cancel(nni_aio *aio, int rv)
+{
+	ws_pipe *p = aio->a_prov_data;
+	nni_mtx_lock(&p->mtx);
+	if (p->user_txaio != aio) {
+		nni_mtx_unlock(&p->mtx);
+		return;
+	}
+	// This aborts the upper send, which will call back with an error
+	// when it is done.
+	nni_aio_cancel(p->txaio, rv);
+	nni_mtx_unlock(&p->mtx);
+}
+
+static void
+ws_pipe_send(void *arg, nni_aio *aio)
+{
+	ws_pipe *p = arg;
+
+	nni_mtx_lock(&p->mtx);
+	if (nni_aio_start(aio, ws_pipe_send_cancel, p) != 0) {
+		nni_mtx_unlock(&p->mtx);
+		return;
+	}
+	p->user_txaio = aio;
+	nni_aio_set_msg(p->txaio, nni_aio_get_msg(aio));
+	nni_aio_set_msg(aio, NULL);
+
+	nni_ws_send_msg(p->ws, p->txaio);
+	nni_mtx_unlock(&p->mtx);
+}
+
+static void
+ws_pipe_fini(void *arg)
+{
+	ws_pipe *p = arg;
+
+	nni_aio_stop(p->rxaio);
+	nni_aio_stop(p->txaio);
+
+	nni_aio_fini(p->rxaio);
+	nni_aio_fini(p->txaio);
+
+	if (p->ws) {
+		nni_ws_fini(p->ws);
+	}
+	nni_mtx_fini(&p->mtx);
+	NNI_FREE_STRUCT(p);
+}
+
+static void
+ws_pipe_close(void *arg)
+{
+	ws_pipe *p = arg;
+
+	nni_mtx_lock(&p->mtx);
+	nni_ws_close(p->ws);
+	nni_mtx_unlock(&p->mtx);
+}
+
+static int
+ws_pipe_init(ws_pipe **pipep, ws_ep *ep, void *ws)
+{
+	ws_pipe *p;
+	int      rv;
+	nni_aio *aio;
+
+	if ((p = NNI_ALLOC_STRUCT(p)) == NULL) {
+		return (NNG_ENOMEM);
+	}
+	nni_mtx_init(&p->mtx);
+
+	// Initialize AIOs.
+	if (((rv = nni_aio_init(&p->txaio, ws_pipe_send_cb, p)) != 0) ||
+	    ((rv = nni_aio_init(&p->rxaio, ws_pipe_recv_cb, p)) != 0)) {
+		ws_pipe_fini(p);
+		return (rv);
+	}
+
+	p->mode   = ep->mode;
+	p->rcvmax = ep->rcvmax;
+	// p->addr   = ep->addr;
+	p->rproto = ep->rproto;
+	p->lproto = ep->lproto;
+	p->ws     = ws;
+
+	if ((aio = nni_list_first(&ep->aios)) != NULL) {
+		nni_aio_list_remove(aio);
+		nni_aio_finish_pipe(aio, p);
+	}
+
+	*pipep = p;
+	return (0);
+}
+
+static uint16_t
+ws_pipe_peer(void *arg)
+{
+	ws_pipe *p = arg;
+
+	return (p->rproto);
+}
+
+static void
+ws_pipe_start(void *arg, nni_aio *aio)
+{
+	if (nni_aio_start(aio, NULL, NULL) == 0) {
+		nni_aio_finish(aio, 0, 0);
+	}
+}
+
+// We have very different approaches for server and client.
+// Servers use the HTTP server framework, and a request methodology.
+
+static int
+ws_ep_bind(void *arg)
+{
+	ws_ep *ep = arg;
+	return (nni_ws_listener_listen(ep->listener));
+}
+
+static void
+ws_ep_cancel(nni_aio *aio, int rv)
+{
+	ws_ep *ep = aio->a_prov_data;
+
+	nni_mtx_lock(&ep->mtx);
+	if (nni_aio_list_active(aio)) {
+		nni_aio_list_remove(aio);
+		nni_aio_finish_error(aio, rv);
+	}
+	nni_mtx_unlock(&ep->mtx);
+}
+
+static void
+ws_ep_accept(void *arg, nni_aio *aio)
+{
+	ws_ep *ep = arg;
+
+	// We already bound, so we just need to look for an available
+	// pipe (created by the handler), and match it.
+	// Otherwise we stick the AIO in the accept list.
+	nni_mtx_lock(&ep->mtx);
+	if (nni_aio_start(aio, ws_ep_cancel, ep) != 0) {
+		nni_mtx_unlock(&ep->mtx);
+		return;
+	}
+	nni_list_append(&ep->aios, aio);
+	if (aio == nni_list_first(&ep->aios)) {
+		nni_ws_listener_accept(ep->listener, ep->accaio);
+	}
+	nni_mtx_unlock(&ep->mtx);
+}
+
+static void
+ws_ep_connect(void *arg, nni_aio *aio)
+{
+	ws_ep *ep = arg;
+	int    rv;
+
+	nni_mtx_lock(&ep->mtx);
+	NNI_ASSERT(nni_list_empty(&ep->aios));
+
+	// If we can't start, then its dying and we can't report
+	// either.
+	if ((rv = nni_aio_start(aio, ws_ep_cancel, ep)) != 0) {
+		nni_mtx_unlock(&ep->mtx);
+		return;
+	}
+
+	nni_list_append(&ep->aios, aio);
+	nni_ws_dialer_dial(ep->dialer, ep->connaio);
+	nni_mtx_unlock(&ep->mtx);
+}
+
+static int
+ws_ep_setopt_recvmaxsz(void *arg, const void *v, size_t sz)
+{
+	ws_ep *ep = arg;
+	if (ep == NULL) {
+		return (nni_chkopt_size(v, sz, 0, NNI_MAXSZ));
+	}
+	return (nni_setopt_size(&ep->rcvmax, v, sz, 0, NNI_MAXSZ));
+}
+
+static int
+ws_ep_getopt_recvmaxsz(void *arg, void *v, size_t *szp)
+{
+	ws_ep *ep = arg;
+	return (nni_getopt_size(ep->rcvmax, v, szp));
+}
+
+static nni_tran_pipe_option ws_pipe_options[] = {
+#if 0
+	// clang-format off
+	{ NNG_OPT_LOCADDR, ws_pipe_getopt_locaddr },
+	{ NNG_OPT_REMADDR, ws_pipe_getopt_remaddr },
+	// clang-format on
+#endif
+	// terminate list
+	{ NULL, NULL }
+};
+
+static nni_tran_pipe ws_pipe_ops = {
+	.p_fini    = ws_pipe_fini,
+	.p_start   = ws_pipe_start,
+	.p_send    = ws_pipe_send,
+	.p_recv    = ws_pipe_recv,
+	.p_close   = ws_pipe_close,
+	.p_peer    = ws_pipe_peer,
+	.p_options = ws_pipe_options,
+};
+
+static nni_tran_ep_option ws_ep_options[] = {
+	{
+	    .eo_name   = NNG_OPT_RECVMAXSZ,
+	    .eo_getopt = ws_ep_getopt_recvmaxsz,
+	    .eo_setopt = ws_ep_setopt_recvmaxsz,
+	},
+	// terminate list
+	{ NULL, NULL, NULL },
+};
+
+static void
+ws_ep_fini(void *arg)
+{
+	ws_ep *ep = arg;
+
+	nni_aio_stop(ep->accaio);
+	nni_aio_stop(ep->connaio);
+	nni_aio_fini(ep->accaio);
+	nni_aio_fini(ep->connaio);
+	if (ep->listener != NULL) {
+		nni_ws_listener_fini(ep->listener);
+	}
+	if (ep->dialer != NULL) {
+		nni_ws_dialer_fini(ep->dialer);
+	}
+	nni_strfree(ep->addr);
+	nni_strfree(ep->protoname);
+	nni_mtx_fini(&ep->mtx);
+	NNI_FREE_STRUCT(ep);
+}
+
+static void
+ws_ep_conn_cb(void *arg)
+{
+	ws_ep *  ep = arg;
+	ws_pipe *p;
+	nni_aio *caio = ep->connaio;
+	nni_aio *uaio;
+	int      rv;
+	nni_ws * ws = NULL;
+
+	nni_mtx_lock(&ep->mtx);
+	if (nni_aio_result(caio) == 0) {
+		ws = nni_aio_get_pipe(caio);
+	}
+	if ((uaio = nni_list_first(&ep->aios)) == NULL) {
+		// The client stopped caring about this!
+		if (ws != NULL) {
+			nni_ws_fini(ws);
+		}
+		nni_mtx_unlock(&ep->mtx);
+		return;
+	}
+	nni_aio_list_remove(uaio);
+	NNI_ASSERT(nni_list_empty(&ep->aios));
+	if ((rv = nni_aio_result(caio)) != 0) {
+		nni_aio_finish_error(uaio, rv);
+	} else if ((rv = ws_pipe_init(&p, ep, ws)) != 0) {
+		nni_ws_fini(ws);
+		nni_aio_finish_error(uaio, rv);
+	} else {
+		nni_aio_finish_pipe(uaio, p);
+	}
+	nni_mtx_unlock(&ep->mtx);
+}
+
+static void
+ws_ep_close(void *arg)
+{
+	ws_ep *ep = arg;
+
+	if (ep->mode == NNI_EP_MODE_LISTEN) {
+		nni_ws_listener_close(ep->listener);
+	} else {
+		nni_ws_dialer_close(ep->dialer);
+	}
+}
+
+static void
+ws_ep_acc_cb(void *arg)
+{
+	ws_ep *  ep   = arg;
+	nni_aio *aaio = ep->accaio;
+	nni_aio *uaio;
+	int      rv;
+
+	nni_mtx_lock(&ep->mtx);
+	uaio = nni_list_first(&ep->aios);
+	if ((rv = nni_aio_result(aaio)) != 0) {
+		if (uaio != NULL) {
+			nni_aio_list_remove(uaio);
+			nni_aio_finish_error(uaio, rv);
+		}
+	} else {
+		nni_ws *ws = nni_aio_get_pipe(aaio);
+		if (uaio != NULL) {
+			ws_pipe *p;
+			// Make a pipe
+			nni_aio_list_remove(uaio);
+			if ((rv = ws_pipe_init(&p, ep, ws)) != 0) {
+				nni_ws_close(ws);
+				nni_aio_finish_error(uaio, rv);
+			} else {
+				nni_aio_finish_pipe(uaio, p);
+			}
+		}
+	}
+	if (!nni_list_empty(&ep->aios)) {
+		nni_ws_listener_accept(ep->listener, aaio);
+	}
+	nni_mtx_unlock(&ep->mtx);
+}
+
+static int
+ws_ep_init(void **epp, const char *url, nni_sock *sock, int mode)
+{
+	ws_ep *     ep;
+	const char *pname;
+	int         rv;
+
+	if ((ep = NNI_ALLOC_STRUCT(ep)) == NULL) {
+		return (NNG_ENOMEM);
+	}
+
+	nni_mtx_init(&ep->mtx);
+
+	// List of pipes (server only).
+	nni_aio_list_init(&ep->aios);
+
+	ep->mode   = mode;
+	ep->lproto = nni_sock_proto(sock);
+	ep->rproto = nni_sock_peer(sock);
+
+	if (mode == NNI_EP_MODE_DIAL) {
+		pname = nni_sock_peer_name(sock);
+		rv    = nni_ws_dialer_init(&ep->dialer, url);
+	} else {
+		pname = nni_sock_proto_name(sock);
+		rv    = nni_ws_listener_init(&ep->listener, url);
+	}
+
+	if ((rv == 0) && ((ep->addr = nni_strdup(url)) == NULL)) {
+		rv = NNG_ENOMEM;
+	}
+	if ((rv != 0) ||
+	    ((rv = nni_aio_init(&ep->connaio, ws_ep_conn_cb, ep)) != 0) ||
+	    ((rv = nni_aio_init(&ep->accaio, ws_ep_acc_cb, ep)) != 0) ||
+	    ((rv = nni_asprintf(&ep->protoname, "%s.sp.nanomsg.org", pname)) !=
+	        0)) {
+		ws_ep_fini(ep);
+		return (rv);
+	}
+
+	*epp = ep;
+	return (0);
+}
+static int
+ws_tran_init(void)
+{
+	return (0);
+}
+
+static void
+ws_tran_fini(void)
+{
+}
+
+static nni_tran_ep ws_ep_ops = {
+	.ep_init    = ws_ep_init,
+	.ep_fini    = ws_ep_fini,
+	.ep_connect = ws_ep_connect,
+	.ep_bind    = ws_ep_bind,
+	.ep_accept  = ws_ep_accept,
+	.ep_close   = ws_ep_close,
+	.ep_options = ws_ep_options,
+};
+
+static nni_tran ws_tran = {
+	.tran_version = NNI_TRANSPORT_VERSION,
+	.tran_scheme  = "ws",
+	.tran_ep      = &ws_ep_ops,
+	.tran_pipe    = &ws_pipe_ops,
+	.tran_init    = ws_tran_init,
+	.tran_fini    = ws_tran_fini,
+};
+
+int
+nng_ws_register(void)
+{
+	return (nni_tran_register(&ws_tran));
+}