fixes #143 Protocols and transports should be "configurable"

This makes all the protocols and transports optional.  All
of them except ZeroTier are enabled by default, but you can
now disable them (remove from the build) with cmake options.

The test suite is modified so that tests still run as much
as they can, but skip over things caused by missing functionality
from the library (due to configuration).

Further, the constant definitions and prototypes for functions
that are specific to transports or protocols are moved into
appropriate headers, which should be included directly by
applications wishing to use these.

We have also added and improved documentation -- all of the
transports are documented, and several more man pages for
protocols have been added.  (Req/Rep and Surveyor are still
missing.)

1 files changed, 519 insertions, 0 deletions

diff --git a/src/protocol/pair1/pair.c b/src/protocol/pair1/pair.c
new file mode 100644
index 00000000..3f6f63fc
--- /dev/null
+++ b/src/protocol/pair1/pair.c
@@ -0,0 +1,519 @@
+//
+// Copyright 2017 Garrett D'Amore <garrett@damore.org>
+// 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 <stdlib.h>
+#include <string.h>
+
+#include "core/nng_impl.h"
+
+#include "protocol/pair1/pair.h"
+
+// Pair protocol.  The PAIRv1 protocol is a simple 1:1 messaging pattern,
+// usually, but it can support a polyamorous mode where a single server can
+// communicate with multiple partners.
+
+#ifndef NNI_PROTO_PAIR_V1
+#define NNI_PROTO_PAIR_V1 NNI_PROTO(1, 1)
+#endif
+
+typedef struct pair1_pipe pair1_pipe;
+typedef struct pair1_sock pair1_sock;
+
+static void pair1_sock_getq_cb(void *);
+static void pair1_pipe_send_cb(void *);
+static void pair1_pipe_recv_cb(void *);
+static void pair1_pipe_getq_cb(void *);
+static void pair1_pipe_putq_cb(void *);
+static void pair1_pipe_fini(void *);
+
+// pair1_sock is our per-socket protocol private structure.
+struct pair1_sock {
+	nni_msgq *  uwq;
+	nni_msgq *  urq;
+	int         raw;
+	int         ttl;
+	nni_mtx     mtx;
+	nni_idhash *pipes;
+	nni_list    plist;
+	int         started;
+	int         poly;
+	nni_aio *   aio_getq;
+};
+
+// pair1_pipe is our per-pipe protocol private structure.
+struct pair1_pipe {
+	nni_pipe *    npipe;
+	pair1_sock *  psock;
+	nni_msgq *    sendq;
+	nni_aio *     aio_send;
+	nni_aio *     aio_recv;
+	nni_aio *     aio_getq;
+	nni_aio *     aio_putq;
+	nni_list_node node;
+};
+
+static void
+pair1_sock_fini(void *arg)
+{
+	pair1_sock *s = arg;
+
+	nni_aio_fini(s->aio_getq);
+	nni_idhash_fini(s->pipes);
+	nni_mtx_fini(&s->mtx);
+
+	NNI_FREE_STRUCT(s);
+}
+
+static int
+pair1_sock_init(void **sp, nni_sock *nsock)
+{
+	pair1_sock *s;
+	int         rv;
+
+	if ((s = NNI_ALLOC_STRUCT(s)) == NULL) {
+		return (NNG_ENOMEM);
+	}
+	if ((rv = nni_idhash_init(&s->pipes)) != 0) {
+		NNI_FREE_STRUCT(s);
+		return (NNG_ENOMEM);
+	}
+	NNI_LIST_INIT(&s->plist, pair1_pipe, node);
+
+	// Raw mode uses this.
+	nni_mtx_init(&s->mtx);
+
+	if ((rv = nni_aio_init(&s->aio_getq, pair1_sock_getq_cb, s)) != 0) {
+		pair1_sock_fini(s);
+		return (rv);
+	}
+
+	s->raw  = 0;
+	s->poly = 0;
+	s->uwq  = nni_sock_sendq(nsock);
+	s->urq  = nni_sock_recvq(nsock);
+	s->ttl  = 8;
+	*sp     = s;
+
+	return (0);
+}
+
+static void
+pair1_pipe_fini(void *arg)
+{
+	pair1_pipe *p = arg;
+	nni_aio_fini(p->aio_send);
+	nni_aio_fini(p->aio_recv);
+	nni_aio_fini(p->aio_putq);
+	nni_aio_fini(p->aio_getq);
+	nni_msgq_fini(p->sendq);
+	NNI_FREE_STRUCT(p);
+}
+
+static int
+pair1_pipe_init(void **pp, nni_pipe *npipe, void *psock)
+{
+	pair1_pipe *p;
+	int         rv;
+
+	if ((p = NNI_ALLOC_STRUCT(p)) == NULL) {
+		return (NNG_ENOMEM);
+	}
+	if (((rv = nni_msgq_init(&p->sendq, 2)) != 0) ||
+	    ((rv = nni_aio_init(&p->aio_send, pair1_pipe_send_cb, p)) != 0) ||
+	    ((rv = nni_aio_init(&p->aio_recv, pair1_pipe_recv_cb, p)) != 0) ||
+	    ((rv = nni_aio_init(&p->aio_getq, pair1_pipe_getq_cb, p)) != 0) ||
+	    ((rv = nni_aio_init(&p->aio_putq, pair1_pipe_putq_cb, p)) != 0)) {
+		pair1_pipe_fini(p);
+		return (NNG_ENOMEM);
+	}
+
+	p->npipe = npipe;
+	p->psock = psock;
+	*pp      = p;
+
+	return (rv);
+}
+
+static int
+pair1_pipe_start(void *arg)
+{
+	pair1_pipe *p = arg;
+	pair1_sock *s = p->psock;
+	uint32_t    id;
+	int         rv;
+
+	id = nni_pipe_id(p->npipe);
+	nni_mtx_lock(&s->mtx);
+	if ((rv = nni_idhash_insert(s->pipes, id, p)) != 0) {
+		nni_mtx_unlock(&s->mtx);
+		return (rv);
+	}
+	if (!s->poly) {
+		if (!nni_list_empty(&s->plist)) {
+			nni_idhash_remove(s->pipes, id);
+			nni_mtx_unlock(&s->mtx);
+			return (NNG_EBUSY);
+		}
+	} else {
+		if (!s->started) {
+			nni_msgq_aio_get(s->uwq, s->aio_getq);
+		}
+	}
+	nni_list_append(&s->plist, p);
+	s->started = 1;
+	nni_mtx_unlock(&s->mtx);
+
+	// Schedule a getq.  In polyamorous mode we get on the per pipe
+	// sendq, as the socket distributes to us. In monogamous mode
+	// we bypass and get from the upper writeq directly (saving a
+	// set of context switches).
+	if (s->poly) {
+		nni_msgq_aio_get(p->sendq, p->aio_getq);
+	} else {
+		nni_msgq_aio_get(s->uwq, p->aio_getq);
+	}
+	// And the pipe read of course.
+	nni_pipe_recv(p->npipe, p->aio_recv);
+
+	return (0);
+}
+
+static void
+pair1_pipe_stop(void *arg)
+{
+	pair1_pipe *p = arg;
+	pair1_sock *s = p->psock;
+
+	nni_mtx_lock(&s->mtx);
+	nni_idhash_remove(s->pipes, nni_pipe_id(p->npipe));
+	nni_list_node_remove(&p->node);
+	nni_mtx_unlock(&s->mtx);
+
+	nni_msgq_close(p->sendq);
+	nni_aio_stop(p->aio_send);
+	nni_aio_stop(p->aio_recv);
+	nni_aio_stop(p->aio_putq);
+	nni_aio_stop(p->aio_getq);
+}
+
+static void
+pair1_pipe_recv_cb(void *arg)
+{
+	pair1_pipe *p = arg;
+	pair1_sock *s = p->psock;
+	nni_msg *   msg;
+	uint32_t    hdr;
+	nni_pipe *  npipe = p->npipe;
+	int         rv;
+
+	if (nni_aio_result(p->aio_recv) != 0) {
+		nni_pipe_stop(p->npipe);
+		return;
+	}
+
+	msg = nni_aio_get_msg(p->aio_recv);
+	nni_aio_set_msg(p->aio_recv, NULL);
+
+	// Store the pipe ID.
+	nni_msg_set_pipe(msg, nni_pipe_id(p->npipe));
+
+	// If the message is missing the hop count header, scrap it.
+	if (nni_msg_len(msg) < sizeof(uint32_t)) {
+		nni_msg_free(msg);
+		nni_pipe_stop(npipe);
+		return;
+	}
+	hdr = nni_msg_trim_u32(msg);
+	if (hdr & 0xffffff00) {
+		nni_msg_free(msg);
+		nni_pipe_stop(npipe);
+		return;
+	}
+
+	// If we bounced too many times, discard the message, but
+	// keep getting more.
+	if (hdr > (unsigned) s->ttl) {
+		nni_msg_free(msg);
+		nni_pipe_recv(npipe, p->aio_recv);
+		return;
+	}
+
+	// Store the hop count in the header.
+	if ((rv = nni_msg_header_append_u32(msg, hdr)) != 0) {
+		nni_msg_free(msg);
+		nni_pipe_recv(npipe, p->aio_recv);
+		return;
+	}
+
+	// Send the message up.
+	nni_aio_set_msg(p->aio_putq, msg);
+	nni_msgq_aio_put(s->urq, p->aio_putq);
+}
+
+static void
+pair1_sock_getq_cb(void *arg)
+{
+	pair1_pipe *p;
+	pair1_sock *s = arg;
+	nni_msg *   msg;
+	uint32_t    id;
+
+	if (nni_aio_result(s->aio_getq) != 0) {
+		// Socket closing...
+		return;
+	}
+
+	msg = nni_aio_get_msg(s->aio_getq);
+	nni_aio_set_msg(s->aio_getq, NULL);
+
+	// By definition we are in polyamorous mode.
+	NNI_ASSERT(s->poly);
+
+	p = NULL;
+	nni_mtx_lock(&s->mtx);
+	// If no pipe was requested, we look for any connected peer.
+	if (((id = nni_msg_get_pipe(msg)) == 0) &&
+	    (!nni_list_empty(&s->plist))) {
+		p = nni_list_first(&s->plist);
+	} else {
+		nni_idhash_find(s->pipes, id, (void **) &p);
+	}
+	if (p == NULL) {
+		// Pipe not present!
+		nni_mtx_unlock(&s->mtx);
+		nni_msg_free(msg);
+		nni_msgq_aio_get(s->uwq, s->aio_getq);
+		return;
+	}
+
+	// Try a non-blocking send.  If this fails we just discard the
+	// message.  We have to do this to avoid head-of-line blocking
+	// for messages sent to other pipes.  Note that there is some
+	// buffering in the sendq.
+	if (nni_msgq_tryput(p->sendq, msg) != 0) {
+		nni_msg_free(msg);
+	}
+
+	nni_mtx_unlock(&s->mtx);
+	nni_msgq_aio_get(s->uwq, s->aio_getq);
+}
+
+static void
+pair1_pipe_putq_cb(void *arg)
+{
+	pair1_pipe *p = arg;
+
+	if (nni_aio_result(p->aio_putq) != 0) {
+		nni_msg_free(nni_aio_get_msg(p->aio_putq));
+		nni_aio_set_msg(p->aio_putq, NULL);
+		nni_pipe_stop(p->npipe);
+		return;
+	}
+	nni_pipe_recv(p->npipe, p->aio_recv);
+}
+
+static void
+pair1_pipe_getq_cb(void *arg)
+{
+	pair1_pipe *p = arg;
+	pair1_sock *s = p->psock;
+	nni_msg *   msg;
+	uint32_t    hops;
+
+	if (nni_aio_result(p->aio_getq) != 0) {
+		nni_pipe_stop(p->npipe);
+		return;
+	}
+
+	msg = nni_aio_get_msg(p->aio_getq);
+	nni_aio_set_msg(p->aio_getq, NULL);
+
+	// Raw mode messages have the header already formed, with
+	// a hop count.  Cooked mode messages have no
+	// header so we have to add one.
+	if (s->raw) {
+		if (nni_msg_header_len(msg) != sizeof(uint32_t)) {
+			goto badmsg;
+		}
+		hops = nni_msg_header_trim_u32(msg);
+	} else {
+		// Strip off any previously existing header, such as when
+		// replying to messages.
+		nni_msg_header_clear(msg);
+		hops = 0;
+	}
+
+	hops++;
+
+	// Insert the hops header.
+	if (nni_msg_header_append_u32(msg, hops) != 0) {
+		goto badmsg;
+	}
+
+	nni_aio_set_msg(p->aio_send, msg);
+	nni_pipe_send(p->npipe, p->aio_send);
+	return;
+
+badmsg:
+	nni_msg_free(msg);
+	nni_msgq_aio_get(s->poly ? p->sendq : s->uwq, p->aio_getq);
+}
+
+static void
+pair1_pipe_send_cb(void *arg)
+{
+	pair1_pipe *p = arg;
+	pair1_sock *s = p->psock;
+
+	if (nni_aio_result(p->aio_send) != 0) {
+		nni_msg_free(nni_aio_get_msg(p->aio_send));
+		nni_aio_set_msg(p->aio_send, NULL);
+		nni_pipe_stop(p->npipe);
+		return;
+	}
+
+	// In polyamorous mode, we want to get from the sendq; in
+	// monogamous we get from upper writeq.
+	nni_msgq_aio_get(s->poly ? p->sendq : s->uwq, p->aio_getq);
+}
+
+static void
+pair1_sock_open(void *arg)
+{
+	NNI_ARG_UNUSED(arg);
+}
+
+static void
+pair1_sock_close(void *arg)
+{
+	NNI_ARG_UNUSED(arg);
+}
+
+static int
+pair1_sock_setopt_raw(void *arg, const void *buf, size_t sz)
+{
+	pair1_sock *s = arg;
+	int         rv;
+	nni_mtx_lock(&s->mtx);
+	rv = s->started ? NNG_ESTATE : nni_setopt_int(&s->raw, buf, sz, 0, 1);
+	nni_mtx_unlock(&s->mtx);
+	return (rv);
+}
+
+static int
+pair1_sock_getopt_raw(void *arg, void *buf, size_t *szp)
+{
+	pair1_sock *s = arg;
+	return (nni_getopt_int(s->raw, buf, szp));
+}
+
+static int
+pair1_sock_setopt_maxttl(void *arg, const void *buf, size_t sz)
+{
+	pair1_sock *s = arg;
+	int         rv;
+	nni_mtx_lock(&s->mtx); // Have to be locked against recv cb.
+	rv = nni_setopt_int(&s->ttl, buf, sz, 1, 255);
+	nni_mtx_unlock(&s->mtx);
+	return (rv);
+}
+
+static int
+pair1_sock_getopt_maxttl(void *arg, void *buf, size_t *szp)
+{
+	pair1_sock *s = arg;
+	return (nni_getopt_int(s->ttl, buf, szp));
+}
+
+static int
+pair1_sock_setopt_poly(void *arg, const void *buf, size_t sz)
+{
+	pair1_sock *s = arg;
+	int         rv;
+	nni_mtx_lock(&s->mtx);
+	rv = s->started ? NNG_ESTATE : nni_setopt_int(&s->poly, buf, sz, 0, 1);
+	nni_mtx_unlock(&s->mtx);
+	return (rv);
+}
+
+static int
+pair1_sock_getopt_poly(void *arg, void *buf, size_t *szp)
+{
+	pair1_sock *s = arg;
+	return (nni_getopt_int(s->poly, buf, szp));
+}
+
+static void
+pair1_sock_send(void *arg, nni_aio *aio)
+{
+	pair1_sock *s = arg;
+
+	nni_msgq_aio_put(s->uwq, aio);
+}
+
+static void
+pair1_sock_recv(void *arg, nni_aio *aio)
+{
+	pair1_sock *s = arg;
+
+	nni_msgq_aio_get(s->urq, aio);
+}
+
+static nni_proto_pipe_ops pair1_pipe_ops = {
+	.pipe_init  = pair1_pipe_init,
+	.pipe_fini  = pair1_pipe_fini,
+	.pipe_start = pair1_pipe_start,
+	.pipe_stop  = pair1_pipe_stop,
+};
+
+static nni_proto_sock_option pair1_sock_options[] = {
+	{
+	    .pso_name   = NNG_OPT_RAW,
+	    .pso_getopt = pair1_sock_getopt_raw,
+	    .pso_setopt = pair1_sock_setopt_raw,
+	},
+	{
+	    .pso_name   = NNG_OPT_MAXTTL,
+	    .pso_getopt = pair1_sock_getopt_maxttl,
+	    .pso_setopt = pair1_sock_setopt_maxttl,
+	},
+	{
+	    .pso_name   = NNG_OPT_PAIR1_POLY,
+	    .pso_getopt = pair1_sock_getopt_poly,
+	    .pso_setopt = pair1_sock_setopt_poly,
+	},
+	// terminate list
+	{ NULL, NULL, NULL },
+};
+
+static nni_proto_sock_ops pair1_sock_ops = {
+	.sock_init    = pair1_sock_init,
+	.sock_fini    = pair1_sock_fini,
+	.sock_open    = pair1_sock_open,
+	.sock_close   = pair1_sock_close,
+	.sock_recv    = pair1_sock_recv,
+	.sock_send    = pair1_sock_send,
+	.sock_options = pair1_sock_options,
+};
+
+static nni_proto pair1_proto = {
+	.proto_version  = NNI_PROTOCOL_VERSION,
+	.proto_self     = { NNI_PROTO_PAIR_V1, "pair1" },
+	.proto_peer     = { NNI_PROTO_PAIR_V1, "pair1" },
+	.proto_flags    = NNI_PROTO_FLAG_SNDRCV,
+	.proto_sock_ops = &pair1_sock_ops,
+	.proto_pipe_ops = &pair1_pipe_ops,
+};
+
+int
+nng_pair1_open(nng_socket *sidp)
+{
+	return (nni_proto_open(sidp, &pair1_proto));
+}