fixes #1189 Extract and deprecate polyamorous mode

8 files changed, 1047 insertions, 487 deletions

diff --git a/docs/man/nng_pair.7.adoc b/docs/man/nng_pair.7.adoc
index dff13e8e..62075753 100644
--- a/docs/man/nng_pair.7.adoc
+++ b/docs/man/nng_pair.7.adoc
@@ -49,10 +49,6 @@ Applications that require reliable delivery semantics should consider using
 xref:nng_req.7.adoc[_req_] sockets, or
 implement their own acknowledgment layer on top of _pair_ sockets.
 
-In order to avoid head-of-line blocking conditions, _polyamorous_ mode _pair_
-sockets (version 1 only) discard messages if they are unable to deliver them
-to a peer.
-
 === Protocol Versions
 
 Version 0 is the legacy version of this protocol.
@@ -66,34 +62,39 @@ https://github.com/go-mangos/mangos[mangos].
 Version 1 of the protocol offers improved protection against loops when
 used with xref:nng_device.3.adoc[`nng_device()`].
 
-NOTE: Version 1 of this protocol is considered experimental at this time.
-
 === Polyamorous Mode
 
-CAUTION: Polyamorous mode was provided as an experiment, and that experiment
-is deemed to have failed.
-Thus use of this mode is discouraged.
-In particular, the design cannot function over
-xref:nng_device.3.adoc[device] proxies.
-Consequently, this mode may be removed in a future release.
+WARNING: Polyamorous mode is deprecated, and support for it will likely
+be removed in a future release.
+Applications are strongly discouraged from making further use of it.
 
 Normally pair sockets are for one-to-one communication, and a given peer
 will reject new connections if it already has an active connection to another
 peer.
 
-In ((_polyamorous_ mode)), which is only available with version 1, a socket can
-support many one-to-one connections.
+((_Polyamorous_ mode)) changes this, to allow a socket to communicate with
+multiple directly-connected peers.
+This mode is enabled by opening a socket with the
+xref:nng_pair_open.3.adoc[`nng_pair1_open_poly()`]
+function
+
+NOTE: Polyamorous mode is only available when using pair version 1.
+
+In polyamorous mode a socket can support many one-to-one connections.
 In this mode, the application must
 choose the remote peer to receive an outgoing message by setting the
 xref:nng_pipe.5.adoc[`nng_pipe`] to use for the outgoing message with
 the xref:nng_msg_set_pipe.3.adoc[`nng_msg_set_pipe()`] function.
 
+If no remote peer is specified by the sender, then the protocol will select
+any available connected peer.
+
 Most often the value of the outgoing pipe will be obtained from an incoming
 message using the xref:nng_msg_get_pipe.3.adoc[`nng_msg_get_pipe()`] function,
 such as when replying to an incoming message.
 
-NOTE: This capability _only_ works with directly connected peers.
-It is not possible to use polyamorous mode in the presence of proxies.
+NOTE: Directed send _only_ works with directly connected peers.
+It will not function across xref:nng_device.3.adoc[device] proxies.
 
 In order to prevent head-of-line blocking, if the peer on the given pipe
 is not able to receive (or the pipe is no longer available, such as if the
@@ -104,19 +105,16 @@ to the sender.
 
 The following protocol-specific options are available.
 
-((`NNG_OPT_PAIR1_POLY`))::
-
-   (`bool`, version 1 only)  This option enables the use of _polyamorous_ mode.
-   The value is read-write, and takes an integer Boolean value.  The default
-   false value (0) indicates that legacy monogamous mode should be used.
-
-NOTE: This option, and the associated capability are considered failed experiments.
-Thus, use of it is discouraged, and it may be removed in a future release.
-
 xref:nng_options.5.adoc#NNG_OPT_MAXTTL[`NNG_OPT_MAXTTL`]::
 
    (`int`, version 1 only).  Maximum time-to-live.
 
+((`NNG_OPT_PAIR1_POLY`))::
+
+   (`bool`, version 1 only)  This option is no longer supported.
+   Formerly it was used to configure _polyamorous_ mode, but that mode
+   is now established by using the `nng_pair1_open_poly()` function.
+
 === Protocol Headers
 
 Version 0 of the pair protocol has no protocol-specific headers.
diff --git a/docs/man/nng_pair_open.3.adoc b/docs/man/nng_pair_open.3.adoc
index c61e6110..20348123 100644
--- a/docs/man/nng_pair_open.3.adoc
+++ b/docs/man/nng_pair_open.3.adoc
@@ -33,6 +33,8 @@ int nng_pair0_open_raw(nng_socket *s);
 int nng_pair1_open(nng_socket *s);
 
 int nng_pair1_open_raw(nng_socket *s);
+
+int nng_pair1_open_poly(nng_socktet *s);
 ----
 
 == DESCRIPTION
@@ -46,6 +48,12 @@ create a xref:nng_pair.7.adoc[_pair_] version 0 or version 1
 xref:nng_socket.5.adoc[socket] in
 xref:nng.7.adoc#raw_mode[raw] mode and return it at the location pointed to by _s_.
 
+The `nng_pair1_open_poly()` function opens a pair version 1 socket in
+polyamorous mode.
+
+NOTE: Polyamorous mode is deprecated and should not be used in new applications.
+The `nng_pair1_open_poly()` function will likely be removed in a future release.
+
 == RETURN VALUES
 
 These functions returns 0 on success, and non-zero otherwise.
diff --git a/include/nng/protocol/pair1/pair.h b/include/nng/protocol/pair1/pair.h
index b89f3105..c48b2021 100644
--- a/include/nng/protocol/pair1/pair.h
+++ b/include/nng/protocol/pair1/pair.h
@@ -1,5 +1,5 @@
 //
-// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech>
 // Copyright 2018 Capitar IT Group BV <info@capitar.com>
 //
 // This software is supplied under the terms of the MIT License, a
@@ -17,6 +17,7 @@ extern "C" {
 
 NNG_DECL int nng_pair1_open(nng_socket *);
 NNG_DECL int nng_pair1_open_raw(nng_socket *);
+NNG_DECL int nng_pair1_open_poly(nng_socket *);
 
 #ifndef nng_pair_open
 #define nng_pair_open nng_pair1_open
diff --git a/src/protocol/pair1/CMakeLists.txt b/src/protocol/pair1/CMakeLists.txt
index 3f92c585..f586fabe 100644
--- a/src/protocol/pair1/CMakeLists.txt
+++ b/src/protocol/pair1/CMakeLists.txt
@@ -12,7 +12,9 @@
 option (NNG_PROTO_PAIR1 "Enable PAIRv1 protocol." ON)
 mark_as_advanced(NNG_PROTO_PAIR1)
 
-nng_sources_if(NNG_PROTO_PAIR1 pair.c)
+# XXX: break pair1_poly into an ifdef.
+nng_sources_if(NNG_PROTO_PAIR1 pair.c pair1_poly.c)
 nng_headers_if(NNG_PROTO_PAIR1 nng/protocol/pair1/pair.h)
 nng_defines_if(NNG_PROTO_PAIR1 NNG_HAVE_PAIR1)
-nng_test(pair1_test)
\ No newline at end of file
+nng_test(pair1_test)
+nng_test(pair1_poly_test)
\ No newline at end of file
diff --git a/src/protocol/pair1/pair.c b/src/protocol/pair1/pair.c
index f564195d..b98975c3 100644
--- a/src/protocol/pair1/pair.c
+++ b/src/protocol/pair1/pair.c
@@ -13,16 +13,13 @@
 #include "core/nng_impl.h"
 #include "nng/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.
+// Pair protocol.  The PAIRv1 protocol is a simple 1:1 messaging pattern.
 
 #define BUMP_STAT(x) nni_stat_inc_atomic(x, 1)
 
 typedef struct pair1_pipe pair1_pipe;
 typedef struct pair1_sock pair1_sock;
 
-static void pair1_sock_get_cb(void *);
 static void pair1_pipe_send_cb(void *);
 static void pair1_pipe_recv_cb(void *);
 static void pair1_pipe_get_cb(void *);
@@ -40,8 +37,6 @@ struct pair1_sock {
 	nni_idhash *   pipes;
 	nni_list       plist;
 	bool           started;
-	bool           poly;
-	nni_aio        aio_get;
 	nni_stat_item  stat_poly;
 	nni_stat_item  stat_raw;
 	nni_stat_item  stat_reject_mismatch;
@@ -50,13 +45,15 @@ struct pair1_sock {
 	nni_stat_item  stat_rx_malformed;
 	nni_stat_item  stat_tx_malformed;
 	nni_stat_item  stat_tx_drop;
+#ifdef NNG_TEST_LIB
+	bool inject_header;
+#endif
 };
 
 // pair1_pipe is our per-pipe protocol private structure.
 struct pair1_pipe {
 	nni_pipe *    pipe;
 	pair1_sock *  pair;
-	nni_msgq *    send_queue;
 	nni_aio       aio_send;
 	nni_aio       aio_recv;
 	nni_aio       aio_get;
@@ -69,7 +66,6 @@ pair1_sock_fini(void *arg)
 {
 	pair1_sock *s = arg;
 
-	nni_aio_fini(&s->aio_get);
 	nni_idhash_fini(s->pipes);
 	nni_mtx_fini(&s->mtx);
 }
@@ -87,11 +83,8 @@ pair1_sock_init_impl(void *arg, nni_sock *sock, bool raw)
 	// Raw mode uses this.
 	nni_mtx_init(&s->mtx);
 
-	nni_aio_init(&s->aio_get, pair1_sock_get_cb, s);
-
 	nni_stat_init_bool(
 	    &s->stat_poly, "polyamorous", "polyamorous mode?", false);
-	nni_stat_set_lock(&s->stat_poly, &s->mtx);
 	nni_sock_add_stat(sock, &s->stat_poly);
 
 	nni_stat_init_bool(&s->stat_raw, "raw", "raw mode?", raw);
@@ -131,7 +124,6 @@ pair1_sock_init_impl(void *arg, nni_sock *sock, bool raw)
 
 	s->sock = sock;
 	s->raw  = raw;
-	s->poly = false;
 	s->uwq  = nni_sock_sendq(sock);
 	s->urq  = nni_sock_recvq(sock);
 	nni_atomic_init(&s->ttl);
@@ -172,25 +164,18 @@ pair1_pipe_fini(void *arg)
 	nni_aio_fini(&p->aio_recv);
 	nni_aio_fini(&p->aio_put);
 	nni_aio_fini(&p->aio_get);
-	nni_msgq_fini(p->send_queue);
 }
 
 static int
 pair1_pipe_init(void *arg, nni_pipe *pipe, void *pair)
 {
 	pair1_pipe *p = arg;
-	int         rv;
 
 	nni_aio_init(&p->aio_send, pair1_pipe_send_cb, p);
 	nni_aio_init(&p->aio_recv, pair1_pipe_recv_cb, p);
 	nni_aio_init(&p->aio_get, pair1_pipe_get_cb, p);
 	nni_aio_init(&p->aio_put, pair1_pipe_put_cb, p);
 
-	if ((rv = nni_msgq_init(&p->send_queue, 2)) != 0) {
-		pair1_pipe_fini(p);
-		return (rv);
-	}
-
 	p->pipe = pipe;
 	p->pair = pair;
 
@@ -218,31 +203,19 @@ pair1_pipe_start(void *arg)
 		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);
-			BUMP_STAT(&s->stat_reject_already);
-			return (NNG_EBUSY);
-		}
-	} else {
-		if (!s->started) {
-			nni_msgq_aio_get(s->uwq, &s->aio_get);
-		}
+	if (!nni_list_empty(&s->plist)) {
+		nni_idhash_remove(s->pipes, id);
+		nni_mtx_unlock(&s->mtx);
+		BUMP_STAT(&s->stat_reject_already);
+		return (NNG_EBUSY);
 	}
 	nni_list_append(&s->plist, p);
 	s->started = true;
 	nni_mtx_unlock(&s->mtx);
 
-	// Schedule a get.  In polyamorous mode we get on the per pipe
-	// send_queue, as the socket distributes to us. In monogamous mode
-	// we bypass and get from the upper write queue directly (saving a
-	// set of context switches).
-	if (s->poly) {
-		nni_msgq_aio_get(p->send_queue, &p->aio_get);
-	} else {
-		nni_msgq_aio_get(s->uwq, &p->aio_get);
-	}
+	// Schedule a get.
+	nni_msgq_aio_get(s->uwq, &p->aio_get);
+
 	// And the pipe read of course.
 	nni_pipe_recv(p->pipe, &p->aio_recv);
 
@@ -264,8 +237,6 @@ pair1_pipe_close(void *arg)
 	nni_idhash_remove(s->pipes, nni_pipe_id(p->pipe));
 	nni_list_node_remove(&p->node);
 	nni_mtx_unlock(&s->mtx);
-
-	nni_msgq_close(p->send_queue);
 }
 
 static void
@@ -319,47 +290,6 @@ pair1_pipe_recv_cb(void *arg)
 }
 
 static void
-pair1_sock_get_cb(void *arg)
-{
-	pair1_pipe *p;
-	pair1_sock *s = arg;
-	nni_msg *   msg;
-	uint32_t    id;
-
-	if (nni_aio_result(&s->aio_get) != 0) {
-		// Socket closing...
-		return;
-	}
-
-	msg = nni_aio_get_msg(&s->aio_get);
-	nni_aio_set_msg(&s->aio_get, NULL);
-
-	p = NULL;
-	nni_mtx_lock(&s->mtx);
-	// By definition we are in polyamorous mode.
-	NNI_ASSERT(s->poly);
-	// 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);
-	}
-
-	// 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 send_queue.
-	if ((p == NULL) || nni_msgq_tryput(p->send_queue, msg) != 0) {
-		BUMP_STAT(&s->stat_tx_drop);
-		nni_msg_free(msg);
-	}
-
-	nni_mtx_unlock(&s->mtx);
-	nni_msgq_aio_get(s->uwq, &s->aio_get);
-}
-
-static void
 pair1_pipe_put_cb(void *arg)
 {
 	pair1_pipe *p = arg;
@@ -396,10 +326,15 @@ pair1_pipe_get_cb(void *arg)
 		    ((hops = nni_msg_header_trim_u32(msg)) > 254)) {
 			BUMP_STAT(&s->stat_tx_malformed);
 			nni_msg_free(msg);
-			nni_msgq_aio_get(
-			    s->poly ? p->send_queue : s->uwq, &p->aio_get);
+			nni_msgq_aio_get(s->uwq, &p->aio_get);
 			return;
 		}
+#if NNG_TEST_LIB
+	} else if (s->inject_header) {
+		nni_aio_set_msg(&p->aio_send, msg);
+		nni_pipe_send(p->pipe, &p->aio_send);
+		return;
+#endif
 	} else {
 		// Strip off any previously existing header, such as when
 		// replying to messages.
@@ -429,9 +364,7 @@ pair1_pipe_send_cb(void *arg)
 		return;
 	}
 
-	// In polyamorous mode, we want to get from the send_queue; in
-	// monogamous we get from upper write queue.
-	nni_msgq_aio_get(s->poly ? p->send_queue : s->uwq, &p->aio_get);
+	nni_msgq_aio_get(s->uwq, &p->aio_get);
 }
 
 static void
@@ -443,8 +376,7 @@ pair1_sock_open(void *arg)
 static void
 pair1_sock_close(void *arg)
 {
-	pair1_sock *s = arg;
-	nni_aio_close(&s->aio_get);
+	NNI_ARG_UNUSED(arg);
 }
 
 static int
@@ -468,24 +400,19 @@ pair1_sock_get_max_ttl(void *arg, void *buf, size_t *szp, nni_opt_type t)
 	return (nni_copyout_int(nni_atomic_get(&s->ttl), buf, szp, t));
 }
 
+
+#ifdef NNG_TEST_LIB
 static int
-pair1_sock_set_poly(void *arg, const void *buf, size_t sz, nni_opt_type t)
+pair1_set_test_inject_header(void *arg, const void *buf, size_t sz, nni_type t)
 {
 	pair1_sock *s = arg;
 	int         rv;
 	nni_mtx_lock(&s->mtx);
-	rv = s->started ? NNG_ESTATE : nni_copyin_bool(&s->poly, buf, sz, t);
-	nni_stat_set_value(&s->stat_poly, s->poly);
+	rv = nni_copyin_bool(&s->inject_header, buf, sz, t);
 	nni_mtx_unlock(&s->mtx);
 	return (rv);
 }
-
-static int
-pair1_sock_get_poly(void *arg, void *buf, size_t *szp, nni_opt_type t)
-{
-	pair1_sock *s = arg;
-	return (nni_copyout_bool(s->poly, buf, szp, t));
-}
+#endif
 
 static void
 pair1_sock_send(void *arg, nni_aio *aio)
@@ -519,11 +446,14 @@ static nni_option pair1_sock_options[] = {
 	    .o_get  = pair1_sock_get_max_ttl,
 	    .o_set  = pair1_sock_set_max_ttl,
 	},
+#ifdef NNG_TEST_LIB
 	{
-	    .o_name = NNG_OPT_PAIR1_POLY,
-	    .o_get  = pair1_sock_get_poly,
-	    .o_set  = pair1_sock_set_poly,
+	    // Test only option to pass header unmolested.  This allows
+	    // us to inject bad header contents.
+	    .o_name = "pair1_test_inject_header",
+	    .o_set  = pair1_set_test_inject_header,
 	},
+#endif
 	// terminate list
 	{
 	    .o_name = NULL,
diff --git a/src/protocol/pair1/pair1_poly.c b/src/protocol/pair1/pair1_poly.c
new file mode 100644
index 00000000..183c10da
--- /dev/null
+++ b/src/protocol/pair1/pair1_poly.c
@@ -0,0 +1,492 @@
+//
+// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2018 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 "core/nng_impl.h"
+#include "nng/protocol/pair1/pair.h"
+
+// Pair1 polyamorous mode.  The PAIRv1 protocol is normally a simple 1:1
+// messaging pattern, but this mode offers the ability to use a best-effort
+// multicast type of communication.  There are limitations however.
+// Most notably this does not interact well with nng_device type
+// proxies, and there is no support for raw mode.
+
+// THIS FEATURE IS DEPRECATED.  We discourage use in new applications.
+
+#define BUMP_STAT(x) nni_stat_inc_atomic(x, 1)
+
+typedef struct pair1poly_pipe pair1poly_pipe;
+typedef struct pair1poly_sock pair1poly_sock;
+
+static void pair1poly_sock_get_cb(void *);
+static void pair1poly_pipe_send_cb(void *);
+static void pair1poly_pipe_recv_cb(void *);
+static void pair1poly_pipe_get_cb(void *);
+static void pair1poly_pipe_put_cb(void *);
+static void pair1poly_pipe_fini(void *);
+
+// pair1poly_sock is our per-socket protocol private structure.
+struct pair1poly_sock {
+	nni_msgq *     uwq;
+	nni_msgq *     urq;
+	nni_sock *     sock;
+	nni_atomic_int ttl;
+	nni_mtx        mtx;
+	nni_idhash *   pipes;
+	nni_list       plist;
+	bool           started;
+	nni_aio        aio_get;
+	nni_stat_item  stat_poly;
+	nni_stat_item  stat_raw;
+	nni_stat_item  stat_reject_mismatch;
+	nni_stat_item  stat_reject_already;
+	nni_stat_item  stat_ttl_drop;
+	nni_stat_item  stat_rx_malformed;
+	nni_stat_item  stat_tx_malformed;
+	nni_stat_item  stat_tx_drop;
+};
+
+// pair1poly_pipe is our per-pipe protocol private structure.
+struct pair1poly_pipe {
+	nni_pipe *      pipe;
+	pair1poly_sock *pair;
+	nni_msgq *      send_queue;
+	nni_aio         aio_send;
+	nni_aio         aio_recv;
+	nni_aio         aio_get;
+	nni_aio         aio_put;
+	nni_list_node   node;
+};
+
+static void
+pair1poly_sock_fini(void *arg)
+{
+	pair1poly_sock *s = arg;
+
+	nni_aio_fini(&s->aio_get);
+	nni_idhash_fini(s->pipes);
+	nni_mtx_fini(&s->mtx);
+}
+
+static int
+pair1poly_sock_init(void *arg, nni_sock *sock)
+{
+	pair1poly_sock *s = arg;
+
+	if (nni_idhash_init(&s->pipes) != 0) {
+		return (NNG_ENOMEM);
+	}
+	NNI_LIST_INIT(&s->plist, pair1poly_pipe, node);
+
+	// Raw mode uses this.
+	nni_mtx_init(&s->mtx);
+
+	nni_aio_init(&s->aio_get, pair1poly_sock_get_cb, s);
+
+	nni_stat_init_bool(
+	    &s->stat_poly, "polyamorous", "polyamorous mode?", true);
+	nni_sock_add_stat(sock, &s->stat_poly);
+
+	nni_stat_init_bool(&s->stat_raw, "raw", "raw mode?", false);
+
+	nni_stat_init_atomic(&s->stat_reject_mismatch, "mismatch",
+	    "pipes rejected (protocol mismatch)");
+	nni_sock_add_stat(sock, &s->stat_reject_mismatch);
+
+	nni_stat_init_atomic(&s->stat_reject_already, "already",
+	    "pipes rejected (already connected)");
+	nni_sock_add_stat(sock, &s->stat_reject_already);
+
+	nni_stat_init_atomic(&s->stat_ttl_drop, "ttl_drop",
+	    "messages dropped due to too many hops");
+	nni_stat_set_unit(&s->stat_ttl_drop, NNG_UNIT_MESSAGES);
+	nni_sock_add_stat(sock, &s->stat_ttl_drop);
+
+	// This can only increment in polyamorous mode.
+	nni_stat_init_atomic(
+	    &s->stat_tx_drop, "tx_drop", "messages dropped undeliverable");
+	nni_stat_set_unit(&s->stat_tx_drop, NNG_UNIT_MESSAGES);
+	nni_sock_add_stat(sock, &s->stat_tx_drop);
+
+	nni_stat_init_atomic(&s->stat_rx_malformed, "rx_malformed",
+	    "malformed messages received");
+	nni_stat_set_unit(&s->stat_rx_malformed, NNG_UNIT_MESSAGES);
+	nni_sock_add_stat(sock, &s->stat_rx_malformed);
+
+	nni_stat_init_atomic(&s->stat_tx_malformed, "tx_malformed",
+	    "malformed messages not sent");
+	nni_stat_set_unit(&s->stat_tx_malformed, NNG_UNIT_MESSAGES);
+
+	s->sock = sock;
+	s->uwq  = nni_sock_sendq(sock);
+	s->urq  = nni_sock_recvq(sock);
+	nni_atomic_init(&s->ttl);
+	nni_atomic_set(&s->ttl, 8);
+
+	return (0);
+}
+
+static void
+pair1poly_pipe_stop(void *arg)
+{
+	pair1poly_pipe *p = arg;
+
+	nni_aio_stop(&p->aio_send);
+	nni_aio_stop(&p->aio_recv);
+	nni_aio_stop(&p->aio_put);
+	nni_aio_stop(&p->aio_get);
+}
+
+static void
+pair1poly_pipe_fini(void *arg)
+{
+	pair1poly_pipe *p = arg;
+
+	nni_aio_fini(&p->aio_send);
+	nni_aio_fini(&p->aio_recv);
+	nni_aio_fini(&p->aio_put);
+	nni_aio_fini(&p->aio_get);
+	nni_msgq_fini(p->send_queue);
+}
+
+static int
+pair1poly_pipe_init(void *arg, nni_pipe *pipe, void *pair)
+{
+	pair1poly_pipe *p = arg;
+	int             rv;
+
+	nni_aio_init(&p->aio_send, pair1poly_pipe_send_cb, p);
+	nni_aio_init(&p->aio_recv, pair1poly_pipe_recv_cb, p);
+	nni_aio_init(&p->aio_get, pair1poly_pipe_get_cb, p);
+	nni_aio_init(&p->aio_put, pair1poly_pipe_put_cb, p);
+
+	if ((rv = nni_msgq_init(&p->send_queue, 2)) != 0) {
+		pair1poly_pipe_fini(p);
+		return (rv);
+	}
+
+	p->pipe = pipe;
+	p->pair = pair;
+
+	return (0);
+}
+
+static int
+pair1poly_pipe_start(void *arg)
+{
+	pair1poly_pipe *p = arg;
+	pair1poly_sock *s = p->pair;
+	uint32_t        id;
+	int             rv;
+
+	nni_mtx_lock(&s->mtx);
+	if (nni_pipe_peer(p->pipe) != NNG_PAIR1_PEER) {
+		nni_mtx_unlock(&s->mtx);
+		BUMP_STAT(&s->stat_reject_mismatch);
+		// Peer protocol mismatch.
+		return (NNG_EPROTO);
+	}
+
+	id = nni_pipe_id(p->pipe);
+	if ((rv = nni_idhash_insert(s->pipes, id, p)) != 0) {
+		nni_mtx_unlock(&s->mtx);
+		return (rv);
+	}
+	if (!s->started) {
+		nni_msgq_aio_get(s->uwq, &s->aio_get);
+	}
+	nni_list_append(&s->plist, p);
+	s->started = true;
+	nni_mtx_unlock(&s->mtx);
+
+	// Schedule a get.  In polyamorous mode we get on the per pipe
+	// send_queue, as the socket distributes to us. In monogamous mode
+	// we bypass and get from the upper write queue directly (saving a
+	// set of context switches).
+	nni_msgq_aio_get(p->send_queue, &p->aio_get);
+
+	// And the pipe read of course.
+	nni_pipe_recv(p->pipe, &p->aio_recv);
+
+	return (0);
+}
+
+static void
+pair1poly_pipe_close(void *arg)
+{
+	pair1poly_pipe *p = arg;
+	pair1poly_sock *s = p->pair;
+
+	nni_aio_close(&p->aio_send);
+	nni_aio_close(&p->aio_recv);
+	nni_aio_close(&p->aio_put);
+	nni_aio_close(&p->aio_get);
+
+	nni_mtx_lock(&s->mtx);
+	nni_idhash_remove(s->pipes, nni_pipe_id(p->pipe));
+	nni_list_node_remove(&p->node);
+	nni_mtx_unlock(&s->mtx);
+
+	nni_msgq_close(p->send_queue);
+}
+
+static void
+pair1poly_pipe_recv_cb(void *arg)
+{
+	pair1poly_pipe *p = arg;
+	pair1poly_sock *s = p->pair;
+	nni_msg *       msg;
+	uint32_t        hdr;
+	nni_pipe *      pipe = p->pipe;
+	size_t          len;
+
+	if (nni_aio_result(&p->aio_recv) != 0) {
+		nni_pipe_close(p->pipe);
+		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->pipe));
+
+	// If the message is missing the hop count header, scrap it.
+	if ((nni_msg_len(msg) < sizeof(uint32_t)) ||
+	    ((hdr = nni_msg_trim_u32(msg)) > 0xff)) {
+		BUMP_STAT(&s->stat_rx_malformed);
+		nni_msg_free(msg);
+		nni_pipe_close(pipe);
+		return;
+	}
+
+	len = nni_msg_len(msg);
+
+	// If we bounced too many times, discard the message, but
+	// keep getting more.
+	if ((int) hdr > nni_atomic_get(&s->ttl)) {
+		BUMP_STAT(&s->stat_ttl_drop);
+		nni_msg_free(msg);
+		nni_pipe_recv(pipe, &p->aio_recv);
+		return;
+	}
+
+	// Store the hop count in the header.
+	nni_msg_header_must_append_u32(msg, hdr);
+
+	// Send the message up.
+	nni_aio_set_msg(&p->aio_put, msg);
+	nni_sock_bump_rx(s->sock, len);
+	nni_msgq_aio_put(s->urq, &p->aio_put);
+}
+
+static void
+pair1poly_sock_get_cb(void *arg)
+{
+	pair1poly_pipe *p;
+	pair1poly_sock *s = arg;
+	nni_msg *       msg;
+	uint32_t        id;
+
+	if (nni_aio_result(&s->aio_get) != 0) {
+		// Socket closing...
+		return;
+	}
+
+	msg = nni_aio_get_msg(&s->aio_get);
+	nni_aio_set_msg(&s->aio_get, NULL);
+
+	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);
+	}
+
+	// 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 send_queue.
+	if ((p == NULL) || nni_msgq_tryput(p->send_queue, msg) != 0) {
+		BUMP_STAT(&s->stat_tx_drop);
+		nni_msg_free(msg);
+	}
+
+	nni_mtx_unlock(&s->mtx);
+	nni_msgq_aio_get(s->uwq, &s->aio_get);
+}
+
+static void
+pair1poly_pipe_put_cb(void *arg)
+{
+	pair1poly_pipe *p = arg;
+
+	if (nni_aio_result(&p->aio_put) != 0) {
+		nni_msg_free(nni_aio_get_msg(&p->aio_put));
+		nni_aio_set_msg(&p->aio_put, NULL);
+		nni_pipe_close(p->pipe);
+		return;
+	}
+	nni_pipe_recv(p->pipe, &p->aio_recv);
+}
+
+static void
+pair1poly_pipe_get_cb(void *arg)
+{
+	pair1poly_pipe *p = arg;
+	nni_msg *       msg;
+
+	if (nni_aio_result(&p->aio_get) != 0) {
+		nni_pipe_close(p->pipe);
+		return;
+	}
+
+	msg = nni_aio_get_msg(&p->aio_get);
+	nni_aio_set_msg(&p->aio_get, NULL);
+
+	// Cooked mode messages have no header so we have to add one.
+	// Strip off any previously existing header, such as when
+	// replying to messages.
+	nni_msg_header_clear(msg);
+
+	// Insert the hops header.
+	nni_msg_header_must_append_u32(msg, 1);
+
+	nni_aio_set_msg(&p->aio_send, msg);
+	nni_pipe_send(p->pipe, &p->aio_send);
+}
+
+static void
+pair1poly_pipe_send_cb(void *arg)
+{
+	pair1poly_pipe *p = arg;
+
+	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_close(p->pipe);
+		return;
+	}
+
+	nni_msgq_aio_get(p->send_queue, &p->aio_get);
+}
+
+static void
+pair1poly_sock_open(void *arg)
+{
+	NNI_ARG_UNUSED(arg);
+}
+
+static void
+pair1poly_sock_close(void *arg)
+{
+	pair1poly_sock *s = arg;
+	nni_aio_close(&s->aio_get);
+}
+
+static int
+pair1poly_set_max_ttl(void *arg, const void *buf, size_t sz, nni_opt_type t)
+{
+	pair1poly_sock *s = arg;
+	int             rv;
+	int             ttl;
+
+	if ((rv = nni_copyin_int(&ttl, buf, sz, 1, NNI_MAX_MAX_TTL, t)) == 0) {
+		nni_atomic_set(&s->ttl, ttl);
+	}
+
+	return (rv);
+}
+
+static int
+pair1poly_get_max_ttl(void *arg, void *buf, size_t *szp, nni_opt_type t)
+{
+	pair1poly_sock *s = arg;
+	return (nni_copyout_int(nni_atomic_get(&s->ttl), buf, szp, t));
+}
+
+static int
+pair1poly_get_poly(void *arg, void *buf, size_t *szp, nni_opt_type t)
+{
+	NNI_ARG_UNUSED(arg);
+	return (nni_copyout_bool(true, buf, szp, t));
+}
+
+static void
+pair1poly_sock_send(void *arg, nni_aio *aio)
+{
+	pair1poly_sock *s = arg;
+
+	nni_sock_bump_tx(s->sock, nni_msg_len(nni_aio_get_msg(aio)));
+	nni_msgq_aio_put(s->uwq, aio);
+}
+
+static void
+pair1poly_sock_recv(void *arg, nni_aio *aio)
+{
+	pair1poly_sock *s = arg;
+
+	nni_msgq_aio_get(s->urq, aio);
+}
+
+static nni_proto_pipe_ops pair1poly_pipe_ops = {
+	.pipe_size  = sizeof(pair1poly_pipe),
+	.pipe_init  = pair1poly_pipe_init,
+	.pipe_fini  = pair1poly_pipe_fini,
+	.pipe_start = pair1poly_pipe_start,
+	.pipe_close = pair1poly_pipe_close,
+	.pipe_stop  = pair1poly_pipe_stop,
+};
+
+static nni_option pair1poly_sock_options[] = {
+	{
+	    .o_name = NNG_OPT_MAXTTL,
+	    .o_get  = pair1poly_get_max_ttl,
+	    .o_set  = pair1poly_set_max_ttl,
+	},
+	{
+	    .o_name = NNG_OPT_PAIR1_POLY,
+	    .o_get  = pair1poly_get_poly,
+	},
+	// terminate list
+	{
+	    .o_name = NULL,
+	},
+};
+
+static nni_proto_sock_ops pair1poly_sock_ops = {
+	.sock_size    = sizeof(pair1poly_sock),
+	.sock_init    = pair1poly_sock_init,
+	.sock_fini    = pair1poly_sock_fini,
+	.sock_open    = pair1poly_sock_open,
+	.sock_close   = pair1poly_sock_close,
+	.sock_recv    = pair1poly_sock_recv,
+	.sock_send    = pair1poly_sock_send,
+	.sock_options = pair1poly_sock_options,
+};
+
+static nni_proto pair1poly_proto = {
+	.proto_version  = NNI_PROTOCOL_VERSION,
+	.proto_self     = { NNG_PAIR1_SELF, NNG_PAIR1_SELF_NAME },
+	.proto_peer     = { NNG_PAIR1_PEER, NNG_PAIR1_PEER_NAME },
+	.proto_flags    = NNI_PROTO_FLAG_SNDRCV,
+	.proto_sock_ops = &pair1poly_sock_ops,
+	.proto_pipe_ops = &pair1poly_pipe_ops,
+};
+
+int
+nng_pair1_open_poly(nng_socket *sock)
+{
+	return (nni_proto_open(sock, &pair1poly_proto));
+}
diff --git a/src/protocol/pair1/pair1_poly_test.c b/src/protocol/pair1/pair1_poly_test.c
new file mode 100644
index 00000000..c4acbd86
--- /dev/null
+++ b/src/protocol/pair1/pair1_poly_test.c
@@ -0,0 +1,357 @@
+//
+// Copyright 2020 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 <string.h>
+
+#include <nng/nng.h>
+#include <nng/protocol/pair0/pair.h>
+#include <nng/protocol/pair1/pair.h>
+
+#include <testutil.h>
+
+#include <acutest.h>
+
+#define SECOND 1000
+
+#define APPEND_STR(m, s) TEST_NNG_PASS(nng_msg_append(m, s, strlen(s)))
+#define CHECK_STR(m, s)                          \
+	TEST_CHECK(nng_msg_len(m) == strlen(s)); \
+	TEST_CHECK(memcmp(nng_msg_body(m), s, strlen(s)) == 0)
+
+void
+test_poly_best_effort(void)
+{
+	nng_socket s1;
+	nng_socket c1;
+	nng_msg *  msg;
+
+	TEST_NNG_PASS(nng_pair1_open_poly(&s1));
+	TEST_NNG_PASS(nng_pair1_open(&c1));
+
+	TEST_NNG_PASS(nng_setopt_int(s1, NNG_OPT_RECVBUF, 1));
+	TEST_NNG_PASS(nng_setopt_int(s1, NNG_OPT_SENDBUF, 1));
+	TEST_NNG_PASS(nng_setopt_int(c1, NNG_OPT_RECVBUF, 1));
+	TEST_NNG_PASS(nng_setopt_ms(s1, NNG_OPT_SENDTIMEO, SECOND));
+
+	TEST_NNG_PASS(testutil_marry(s1, c1));
+
+	for (int i = 0; i < 10; i++) {
+		TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+		TEST_NNG_PASS(nng_sendmsg(s1, msg, 0));
+	}
+
+	TEST_NNG_PASS(nng_close(s1));
+	TEST_NNG_PASS(nng_close(c1));
+}
+
+void
+test_poly_cooked(void)
+{
+	nng_socket s1;
+	nng_socket c1;
+	nng_socket c2;
+	nng_msg *  msg;
+	bool       v;
+	nng_pipe   p1;
+	nng_pipe   p2;
+
+	TEST_NNG_PASS(nng_pair1_open_poly(&s1));
+	TEST_NNG_PASS(nng_pair1_open(&c1));
+	TEST_NNG_PASS(nng_pair1_open(&c2));
+	TEST_NNG_PASS(nng_setopt_ms(s1, NNG_OPT_SENDTIMEO, SECOND));
+	TEST_NNG_PASS(nng_setopt_ms(c1, NNG_OPT_SENDTIMEO, SECOND));
+	TEST_NNG_PASS(nng_setopt_ms(c2, NNG_OPT_SENDTIMEO, SECOND));
+	TEST_NNG_PASS(nng_setopt_ms(s1, NNG_OPT_RECVTIMEO, SECOND / 10));
+	TEST_NNG_PASS(nng_setopt_ms(c1, NNG_OPT_RECVTIMEO, SECOND / 10));
+	TEST_NNG_PASS(nng_setopt_ms(c2, NNG_OPT_RECVTIMEO, SECOND / 10));
+
+	TEST_NNG_PASS(nng_getopt_bool(s1, NNG_OPT_PAIR1_POLY, &v));
+	TEST_CHECK(v == true);
+
+	TEST_NNG_PASS(testutil_marry(s1, c1));
+	TEST_NNG_PASS(testutil_marry(s1, c2));
+
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	APPEND_STR(msg, "ONE");
+	TEST_NNG_PASS(nng_sendmsg(c1, msg, 0));
+	TEST_NNG_PASS(nng_recvmsg(s1, &msg, 0));
+	CHECK_STR(msg, "ONE");
+	p1 = nng_msg_get_pipe(msg);
+	TEST_CHECK(nng_pipe_id(p1) > 0);
+	nng_msg_free(msg);
+
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	APPEND_STR(msg, "TWO");
+	TEST_NNG_PASS(nng_sendmsg(c2, msg, 0));
+	TEST_NNG_PASS(nng_recvmsg(s1, &msg, 0));
+	CHECK_STR(msg, "TWO");
+	p2 = nng_msg_get_pipe(msg);
+	TEST_CHECK(nng_pipe_id(p2) > 0);
+	nng_msg_free(msg);
+
+	TEST_CHECK(nng_pipe_id(p1) != nng_pipe_id(p2));
+
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+
+	nng_msg_set_pipe(msg, p1);
+	APPEND_STR(msg, "UNO");
+	TEST_NNG_PASS(nng_sendmsg(s1, msg, 0));
+	TEST_NNG_PASS(nng_recvmsg(c1, &msg, 0));
+	CHECK_STR(msg, "UNO");
+	nng_msg_free(msg);
+
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	nng_msg_set_pipe(msg, p2);
+	APPEND_STR(msg, "DOS");
+	TEST_NNG_PASS(nng_sendmsg(s1, msg, 0));
+	TEST_NNG_PASS(nng_recvmsg(c2, &msg, 0));
+	CHECK_STR(msg, "DOS");
+	nng_msg_free(msg);
+
+	TEST_NNG_PASS(nng_close(c1));
+
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	nng_msg_set_pipe(msg, p1);
+	APPEND_STR(msg, "EIN");
+	TEST_NNG_PASS(nng_sendmsg(s1, msg, 0));
+	TEST_NNG_FAIL(nng_recvmsg(c2, &msg, 0), NNG_ETIMEDOUT);
+
+	TEST_NNG_PASS(nng_close(s1));
+	TEST_NNG_PASS(nng_close(c2));
+}
+
+void
+test_poly_default(void)
+{
+	nng_socket s1;
+	nng_socket c1;
+	nng_socket c2;
+	nng_msg *  msg;
+
+	TEST_NNG_PASS(nng_pair1_open_poly(&s1));
+	TEST_NNG_PASS(nng_pair1_open(&c1));
+	TEST_NNG_PASS(nng_pair1_open(&c2));
+	TEST_NNG_PASS(nng_setopt_ms(s1, NNG_OPT_SENDTIMEO, SECOND));
+	TEST_NNG_PASS(nng_setopt_ms(c1, NNG_OPT_SENDTIMEO, SECOND));
+	TEST_NNG_PASS(nng_setopt_ms(c2, NNG_OPT_SENDTIMEO, SECOND));
+
+	TEST_NNG_PASS(testutil_marry(s1, c1));
+	TEST_NNG_PASS(testutil_marry(s1, c2));
+
+	// This assumes poly picks the first suitor.  Applications
+	// should not make the same assumption.
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	APPEND_STR(msg, "YES");
+	TEST_NNG_PASS(nng_sendmsg(s1, msg, 0));
+	TEST_NNG_PASS(nng_recvmsg(c1, &msg, 0));
+	CHECK_STR(msg, "YES");
+	nng_msg_free(msg);
+
+	TEST_NNG_PASS(nng_close(c1));
+	testutil_sleep(10);
+
+	// Verify that the other pipe is chosen as the next suitor.
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	APPEND_STR(msg, "AGAIN");
+	TEST_NNG_PASS(nng_sendmsg(s1, msg, 0));
+	TEST_NNG_PASS(nng_recvmsg(c2, &msg, 0));
+	CHECK_STR(msg, "AGAIN");
+	nng_msg_free(msg);
+
+	TEST_NNG_PASS(nng_close(s1));
+	TEST_NNG_PASS(nng_close(c2));
+}
+
+void
+test_poly_close_abort(void)
+{
+	nng_socket s;
+	nng_socket c;
+
+	TEST_NNG_PASS(nng_pair1_open_poly(&s));
+	TEST_NNG_PASS(nng_pair1_open(&c));
+	TEST_NNG_PASS(nng_setopt_ms(s, NNG_OPT_RECVTIMEO, 100));
+	TEST_NNG_PASS(nng_setopt_ms(s, NNG_OPT_SENDTIMEO, 200));
+	TEST_NNG_PASS(nng_setopt_int(s, NNG_OPT_RECVBUF, 1));
+	TEST_NNG_PASS(nng_setopt_int(c, NNG_OPT_SENDBUF, 20));
+
+	TEST_NNG_PASS(testutil_marry(c, s));
+
+	for (int i = 0; i < 20; i++) {
+		TEST_NNG_SEND_STR(c, "TEST");
+	}
+	testutil_sleep(50);
+
+	TEST_NNG_PASS(nng_close(s));
+	TEST_NNG_PASS(nng_close(c));
+}
+
+
+void
+test_poly_recv_no_header(void)
+{
+	nng_socket s;
+	nng_socket c;
+	nng_msg *  m;
+
+	TEST_NNG_PASS(nng_pair1_open_poly(&s));
+	TEST_NNG_PASS(nng_pair1_open(&c));
+	TEST_NNG_PASS(nng_setopt_bool(c, "pair1_test_inject_header", true));
+	TEST_NNG_PASS(nng_setopt_ms(s, NNG_OPT_RECVTIMEO, 100));
+	TEST_NNG_PASS(nng_setopt_ms(s, NNG_OPT_SENDTIMEO, 200));
+
+	TEST_NNG_PASS(testutil_marry(c, s));
+
+	TEST_NNG_PASS(nng_msg_alloc(&m, 0));
+	TEST_NNG_PASS(nng_sendmsg(c, m, 0));
+	TEST_NNG_FAIL(nng_recvmsg(s, &m, 0), NNG_ETIMEDOUT);
+
+	TEST_NNG_PASS(nng_close(c));
+	TEST_NNG_PASS(nng_close(s));
+}
+
+void
+test_poly_recv_garbage(void)
+{
+	nng_socket s;
+	nng_socket c;
+	nng_msg *  m;
+
+	TEST_NNG_PASS(nng_pair1_open_poly(&s));
+	TEST_NNG_PASS(nng_pair1_open(&c));
+	TEST_NNG_PASS(nng_setopt_bool(c, "pair1_test_inject_header", true));
+	TEST_NNG_PASS(nng_setopt_ms(s, NNG_OPT_RECVTIMEO, 100));
+	TEST_NNG_PASS(nng_setopt_ms(s, NNG_OPT_SENDTIMEO, 200));
+
+	TEST_NNG_PASS(testutil_marry(c, s));
+
+	// ridiculous hop count
+	TEST_NNG_PASS(nng_msg_alloc(&m, 0));
+	TEST_NNG_PASS(nng_msg_append_u32(m, 0x1000));
+	TEST_NNG_PASS(nng_sendmsg(c, m, 0));
+	TEST_NNG_FAIL(nng_recvmsg(s, &m, 0), NNG_ETIMEDOUT);
+
+	TEST_NNG_PASS(nng_close(c));
+	TEST_NNG_PASS(nng_close(s));
+}
+
+void
+test_poly_ttl(void)
+{
+	nng_socket s1;
+	nng_socket c1;
+	nng_msg *  msg;
+	uint32_t   val;
+	int        ttl;
+
+	TEST_NNG_PASS(nng_pair1_open_poly(&s1));
+	TEST_NNG_PASS(nng_pair1_open_raw(&c1));
+	TEST_NNG_PASS(nng_setopt_ms(s1, NNG_OPT_RECVTIMEO, SECOND / 5));
+	TEST_NNG_PASS(nng_setopt_ms(c1, NNG_OPT_RECVTIMEO, SECOND / 5));
+
+	// cannot set insane TTLs
+	TEST_NNG_FAIL(nng_setopt_int(s1, NNG_OPT_MAXTTL, 0), NNG_EINVAL);
+	TEST_NNG_FAIL(nng_setopt_int(s1, NNG_OPT_MAXTTL, 1000), NNG_EINVAL);
+	ttl = 8;
+	TEST_NNG_FAIL(nng_setopt(s1, NNG_OPT_MAXTTL, &ttl, 1), NNG_EINVAL);
+	TEST_NNG_FAIL(nng_setopt_bool(s1, NNG_OPT_MAXTTL, true), NNG_EBADTYPE);
+
+	TEST_NNG_PASS(testutil_marry(s1, c1));
+
+	// Let's check enforcement of TTL
+	TEST_NNG_PASS(nng_setopt_int(s1, NNG_OPT_MAXTTL, 4));
+	TEST_NNG_PASS(nng_getopt_int(s1, NNG_OPT_MAXTTL, &ttl));
+	TEST_CHECK(ttl == 4);
+
+	// Bad TTL bounces
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	TEST_NNG_PASS(nng_msg_header_append_u32(msg, 4));
+	TEST_NNG_PASS(nng_sendmsg(c1, msg, 0));
+	TEST_NNG_FAIL(nng_recvmsg(s1, &msg, 0), NNG_ETIMEDOUT);
+
+	// Good TTL passes
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	TEST_NNG_PASS(nng_msg_append_u32(msg, 0xFEEDFACE));
+	TEST_NNG_PASS(nng_msg_header_append_u32(msg, 3));
+	TEST_NNG_PASS(nng_sendmsg(c1, msg, 0));
+	TEST_NNG_PASS(nng_recvmsg(s1, &msg, 0));
+	TEST_NNG_PASS(nng_msg_trim_u32(msg, &val));
+	TEST_CHECK(val == 0xFEEDFACE);
+	TEST_NNG_PASS(nng_msg_header_trim_u32(msg, &val));
+	TEST_CHECK(val == 4);
+	nng_msg_free(msg);
+
+	// Large TTL passes
+	TEST_NNG_PASS(nng_setopt_int(s1, NNG_OPT_MAXTTL, 15));
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	TEST_NNG_PASS(nng_msg_append_u32(msg, 1234));
+	TEST_NNG_PASS(nng_msg_header_append_u32(msg, 14));
+	TEST_NNG_PASS(nng_sendmsg(c1, msg, 0));
+	TEST_NNG_PASS(nng_recvmsg(s1, &msg, 0));
+	TEST_NNG_PASS(nng_msg_trim_u32(msg, &val));
+	TEST_CHECK(val == 1234);
+	TEST_NNG_PASS(nng_msg_header_trim_u32(msg, &val));
+	TEST_CHECK(val == 15);
+	nng_msg_free(msg);
+
+	// Max TTL fails
+	TEST_NNG_PASS(nng_setopt_int(s1, NNG_OPT_MAXTTL, 15));
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	TEST_NNG_PASS(nng_msg_header_append_u32(msg, 15));
+	TEST_NNG_PASS(nng_sendmsg(c1, msg, 0));
+	TEST_NNG_FAIL(nng_recvmsg(s1, &msg, 0), NNG_ETIMEDOUT);
+
+	TEST_NNG_PASS(nng_close(s1));
+	TEST_NNG_PASS(nng_close(c1));
+}
+
+void
+test_poly_validate_peer(void)
+{
+	nng_socket s1, s2;
+	nng_stat * stats;
+	nng_stat * reject;
+	char       addr[64];
+
+	testutil_scratch_addr("inproc", sizeof(addr), addr);
+
+	TEST_NNG_PASS(nng_pair1_open_poly(&s1));
+	TEST_NNG_PASS(nng_pair0_open(&s2));
+
+	TEST_NNG_PASS(nng_listen(s1, addr, NULL, 0));
+	TEST_NNG_PASS(nng_dial(s2, addr, NULL, NNG_FLAG_NONBLOCK));
+
+	testutil_sleep(100);
+	TEST_NNG_PASS(nng_stats_get(&stats));
+
+	TEST_CHECK(stats != NULL);
+	TEST_CHECK((reject = nng_stat_find_socket(stats, s1)) != NULL);
+	TEST_CHECK((reject = nng_stat_find(reject, "reject")) != NULL);
+
+	TEST_CHECK(nng_stat_type(reject) == NNG_STAT_COUNTER);
+	TEST_CHECK(nng_stat_value(reject) > 0);
+
+	TEST_NNG_PASS(nng_close(s1));
+	TEST_NNG_PASS(nng_close(s2));
+	nng_stats_free(stats);
+}
+
+TEST_LIST = {
+	{ "pair1 polyamorous best effort", test_poly_best_effort },
+	{ "pair1 polyamorous cooked", test_poly_cooked },
+	{ "pair1 polyamorous default", test_poly_default },
+	{ "pair1 polyamorous recv no header", test_poly_recv_no_header },
+	{ "pair1 polyamorous recv garbage", test_poly_recv_garbage },
+	{ "pair1 polyamorous ttl", test_poly_ttl },
+	{ "pair1 polyamorous close abort", test_poly_close_abort },
+	{ "pair1 polyamorous validate peer", test_poly_validate_peer },
+
+	{ NULL, NULL },
+};
diff --git a/src/protocol/pair1/pair1_test.c b/src/protocol/pair1/pair1_test.c
index 7011606a..0f0131b5 100644
--- a/src/protocol/pair1/pair1_test.c
+++ b/src/protocol/pair1/pair1_test.c
@@ -11,8 +11,8 @@
 #include <string.h>
 
 #include <nng/nng.h>
-#include <nng/protocol/pair1/pair.h>
 #include <nng/protocol/pair0/pair.h>
+#include <nng/protocol/pair1/pair.h>
 
 #include <testutil.h>
 
@@ -188,33 +188,33 @@ test_mono_raw_header(void)
 	nng_msg *  msg;
 	uint32_t   v;
 
-	TEST_CHECK(nng_pair1_open_raw(&s1) == 0);
-	TEST_CHECK(nng_pair1_open_raw(&c1) == 0);
+	TEST_NNG_PASS(nng_pair1_open_raw(&s1));
+	TEST_NNG_PASS(nng_pair1_open_raw(&c1));
 
-	TEST_CHECK(nng_setopt_ms(s1, NNG_OPT_RECVTIMEO, SECOND / 5) == 0);
-	TEST_CHECK(nng_setopt_ms(c1, NNG_OPT_RECVTIMEO, SECOND / 5) == 0);
-	TEST_CHECK(testutil_marry(s1, c1) == 0);
+	TEST_NNG_PASS(nng_setopt_ms(s1, NNG_OPT_RECVTIMEO, SECOND / 5));
+	TEST_NNG_PASS(nng_setopt_ms(c1, NNG_OPT_RECVTIMEO, SECOND / 5));
+	TEST_NNG_PASS(testutil_marry(s1, c1));
 
 	// Missing bits in the header
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	TEST_CHECK(nng_sendmsg(c1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(s1, &msg, 0) == NNG_ETIMEDOUT);
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	TEST_NNG_PASS(nng_sendmsg(c1, msg, 0));
+	TEST_NNG_FAIL(nng_recvmsg(s1, &msg, 0), NNG_ETIMEDOUT);
 
 	// Valid header works
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	TEST_CHECK(nng_msg_append_u32(msg, 0xFEEDFACE) == 0);
-	TEST_CHECK(nng_msg_header_append_u32(msg, 1) == 0);
-	TEST_CHECK(nng_sendmsg(c1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(s1, &msg, 0) == 0);
-	TEST_CHECK(nng_msg_trim_u32(msg, &v) == 0);
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	TEST_NNG_PASS(nng_msg_append_u32(msg, 0xFEEDFACE));
+	TEST_NNG_PASS(nng_msg_header_append_u32(msg, 1));
+	TEST_NNG_PASS(nng_sendmsg(c1, msg, 0));
+	TEST_NNG_PASS(nng_recvmsg(s1, &msg, 0));
+	TEST_NNG_PASS(nng_msg_trim_u32(msg, &v));
 	TEST_CHECK(v == 0xFEEDFACE);
 	nng_msg_free(msg);
 
 	// Header with reserved bits set dropped
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	TEST_CHECK(nng_msg_header_append_u32(msg, 0xDEAD0000) == 0);
-	TEST_CHECK(nng_sendmsg(c1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(s1, &msg, 0) == NNG_ETIMEDOUT);
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	TEST_NNG_PASS(nng_msg_header_append_u32(msg, 0xDEAD0000));
+	TEST_NNG_PASS(nng_sendmsg(c1, msg, 0));
+	TEST_NNG_FAIL(nng_recvmsg(s1, &msg, 0), NNG_ETIMEDOUT);
 
 	// Header with no chance to add another hop gets dropped
 	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
@@ -223,313 +223,40 @@ test_mono_raw_header(void)
 	TEST_NNG_FAIL(nng_recvmsg(s1, &msg, 0), NNG_ETIMEDOUT);
 
 	// With the same bits clear it works
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	TEST_CHECK(nng_msg_append_u32(msg, 0xFEEDFACE) == 0);
-	TEST_CHECK(nng_msg_header_append_u32(msg, 1) == 0);
-	TEST_CHECK(nng_sendmsg(c1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(s1, &msg, 0) == 0);
-	TEST_CHECK(nng_msg_trim_u32(msg, &v) == 0);
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	TEST_NNG_PASS(nng_msg_append_u32(msg, 0xFEEDFACE));
+	TEST_NNG_PASS(nng_msg_header_append_u32(msg, 1));
+	TEST_NNG_PASS(nng_sendmsg(c1, msg, 0));
+	TEST_NNG_PASS(nng_recvmsg(s1, &msg, 0));
+	TEST_NNG_PASS(nng_msg_trim_u32(msg, &v));
 	TEST_CHECK(v == 0xFEEDFACE);
 	nng_msg_free(msg);
 
-	TEST_CHECK(nng_close(s1) == 0);
-	TEST_CHECK(nng_close(c1) == 0);
-}
-
-void
-test_poly_best_effort(void)
-{
-	nng_socket s1;
-	nng_socket c1;
-	nng_msg *  msg;
-
-	TEST_CHECK(nng_pair1_open(&s1) == 0);
-	TEST_CHECK(nng_pair1_open(&c1) == 0);
-
-	TEST_CHECK(nng_setopt_bool(s1, NNG_OPT_PAIR1_POLY, true) == 0);
-
-	TEST_CHECK(nng_setopt_int(s1, NNG_OPT_RECVBUF, 1) == 0);
-	TEST_CHECK(nng_setopt_int(s1, NNG_OPT_SENDBUF, 1) == 0);
-	TEST_CHECK(nng_setopt_int(c1, NNG_OPT_RECVBUF, 1) == 0);
-	TEST_CHECK(nng_setopt_ms(s1, NNG_OPT_SENDTIMEO, SECOND) == 0);
-
-	TEST_CHECK(testutil_marry(s1, c1) == 0);
-
-	for (int i = 0; i < 10; i++) {
-		TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-		TEST_CHECK(nng_sendmsg(s1, msg, 0) == 0);
-	}
-
-	TEST_CHECK(nng_close(s1) == 0);
-	TEST_CHECK(nng_close(c1) == 0);
-}
-
-void
-test_poly_cooked(void)
-{
-	nng_socket s1;
-	nng_socket c1;
-	nng_socket c2;
-	nng_msg *  msg;
-	bool       v;
-	nng_pipe   p1;
-	nng_pipe   p2;
-
-	TEST_CHECK(nng_pair1_open(&s1) == 0);
-	TEST_CHECK(nng_pair1_open(&c1) == 0);
-	TEST_CHECK(nng_pair1_open(&c2) == 0);
-	TEST_CHECK(nng_setopt_ms(s1, NNG_OPT_SENDTIMEO, SECOND) == 0);
-	TEST_CHECK(nng_setopt_ms(c1, NNG_OPT_SENDTIMEO, SECOND) == 0);
-	TEST_CHECK(nng_setopt_ms(c2, NNG_OPT_SENDTIMEO, SECOND) == 0);
-	TEST_CHECK(nng_setopt_ms(s1, NNG_OPT_RECVTIMEO, SECOND / 10) == 0);
-	TEST_CHECK(nng_setopt_ms(c1, NNG_OPT_RECVTIMEO, SECOND / 10) == 0);
-	TEST_CHECK(nng_setopt_ms(c2, NNG_OPT_RECVTIMEO, SECOND / 10) == 0);
-
-	TEST_CHECK(nng_getopt_bool(s1, NNG_OPT_PAIR1_POLY, &v) == 0);
-	TEST_CHECK(v == false);
-
-	TEST_CHECK(nng_setopt_bool(s1, NNG_OPT_PAIR1_POLY, true) == 0);
-	TEST_CHECK(nng_getopt_bool(s1, NNG_OPT_PAIR1_POLY, &v) == 0);
-	TEST_CHECK(v == true);
-
-	TEST_CHECK(testutil_marry(s1, c1) == 0);
-	TEST_CHECK(testutil_marry(s1, c2) == 0);
-
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	APPEND_STR(msg, "ONE");
-	TEST_CHECK(nng_sendmsg(c1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(s1, &msg, 0) == 0);
-	CHECK_STR(msg, "ONE");
-	p1 = nng_msg_get_pipe(msg);
-	TEST_CHECK(nng_pipe_id(p1) > 0);
-	nng_msg_free(msg);
-
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	APPEND_STR(msg, "TWO");
-	TEST_CHECK(nng_sendmsg(c2, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(s1, &msg, 0) == 0);
-	CHECK_STR(msg, "TWO");
-	p2 = nng_msg_get_pipe(msg);
-	TEST_CHECK(nng_pipe_id(p2) > 0);
-	nng_msg_free(msg);
-
-	TEST_CHECK(nng_pipe_id(p1) != nng_pipe_id(p2));
-
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-
-	nng_msg_set_pipe(msg, p1);
-	APPEND_STR(msg, "UNO");
-	TEST_CHECK(nng_sendmsg(s1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(c1, &msg, 0) == 0);
-	CHECK_STR(msg, "UNO");
-	nng_msg_free(msg);
-
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	nng_msg_set_pipe(msg, p2);
-	APPEND_STR(msg, "DOS");
-	TEST_CHECK(nng_sendmsg(s1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(c2, &msg, 0) == 0);
-	CHECK_STR(msg, "DOS");
-	nng_msg_free(msg);
-
-	TEST_CHECK(nng_close(c1) == 0);
-
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	nng_msg_set_pipe(msg, p1);
-	APPEND_STR(msg, "EIN");
-	TEST_CHECK(nng_sendmsg(s1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(c2, &msg, 0) == NNG_ETIMEDOUT);
-
-	TEST_CHECK(nng_close(s1) == 0);
-	TEST_CHECK(nng_close(c2) == 0);
-}
-
-void
-test_poly_late(void)
-{
-	nng_socket s1;
-	nng_socket c1;
-	bool       v;
-
-	TEST_CHECK(nng_pair1_open(&s1) == 0);
-	TEST_CHECK(nng_pair1_open(&c1) == 0);
-
-	TEST_CHECK(nng_getopt_bool(s1, NNG_OPT_PAIR1_POLY, &v) == 0);
-	TEST_CHECK(v == false);
-
-	TEST_CHECK(nng_setopt_bool(s1, NNG_OPT_PAIR1_POLY, true) == 0);
-	TEST_CHECK(nng_getopt_bool(s1, NNG_OPT_PAIR1_POLY, &v) == 0);
-	TEST_CHECK(v == true);
-
-	TEST_CHECK(testutil_marry(s1, c1) == 0);
-
-	TEST_CHECK(
-	    nng_setopt_bool(s1, NNG_OPT_PAIR1_POLY, true) == NNG_ESTATE);
-	TEST_CHECK(nng_close(s1) == 0);
-	TEST_CHECK(nng_close(c1) == 0);
-}
-
-void
-test_poly_default(void)
-{
-	nng_socket s1;
-	nng_socket c1;
-	nng_socket c2;
-	nng_msg *  msg;
-
-	TEST_CHECK(nng_pair1_open(&s1) == 0);
-	TEST_CHECK(nng_pair1_open(&c1) == 0);
-	TEST_CHECK(nng_pair1_open(&c2) == 0);
-	TEST_CHECK(nng_setopt_ms(s1, NNG_OPT_SENDTIMEO, SECOND) == 0);
-	TEST_CHECK(nng_setopt_ms(c1, NNG_OPT_SENDTIMEO, SECOND) == 0);
-	TEST_CHECK(nng_setopt_ms(c2, NNG_OPT_SENDTIMEO, SECOND) == 0);
-
-	TEST_CHECK(nng_setopt_bool(s1, NNG_OPT_PAIR1_POLY, true) == 0);
-
-	TEST_CHECK(testutil_marry(s1, c1) == 0);
-	TEST_CHECK(testutil_marry(s1, c2) == 0);
-
-	// This assumes poly picks the first suitor.  Applications
-	// should not make the same assumption.
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	APPEND_STR(msg, "YES");
-	TEST_CHECK(nng_sendmsg(s1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(c1, &msg, 0) == 0);
-	CHECK_STR(msg, "YES");
-	nng_msg_free(msg);
-
-	TEST_CHECK(nng_close(c1) == 0);
-	testutil_sleep(10);
-
-	// Verify that the other pipe is chosen as the next suitor.
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	APPEND_STR(msg, "AGAIN");
-	TEST_CHECK(nng_sendmsg(s1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(c2, &msg, 0) == 0);
-	CHECK_STR(msg, "AGAIN");
-	nng_msg_free(msg);
-
-	TEST_CHECK(nng_close(s1) == 0);
-	TEST_CHECK(nng_close(c2) == 0);
-}
-
-void
-test_poly_raw(void)
-{
-	nng_socket s1;
-	nng_socket c1;
-	nng_socket c2;
-	nng_msg *  msg;
-	bool       v;
-	uint32_t   hops;
-	nng_pipe   p1;
-	nng_pipe   p2;
-
-	TEST_CHECK(nng_pair1_open_raw(&s1) == 0);
-	TEST_CHECK(nng_pair1_open(&c1) == 0);
-	TEST_CHECK(nng_pair1_open(&c2) == 0);
-	TEST_CHECK(nng_setopt_ms(s1, NNG_OPT_RECVTIMEO, SECOND / 5) == 0);
-	TEST_CHECK(nng_setopt_ms(c1, NNG_OPT_RECVTIMEO, SECOND / 5) == 0);
-	TEST_CHECK(nng_setopt_ms(c2, NNG_OPT_RECVTIMEO, SECOND / 5) == 0);
-
-	TEST_CHECK(nng_getopt_bool(s1, NNG_OPT_PAIR1_POLY, &v) == 0);
-	TEST_CHECK(v == 0);
-
-	TEST_CHECK(nng_setopt_bool(s1, NNG_OPT_PAIR1_POLY, true) == 0);
-	TEST_CHECK(nng_getopt_bool(s1, NNG_OPT_PAIR1_POLY, &v) == 0);
-	TEST_CHECK(v == true);
-
-	v = false;
-	TEST_CHECK(nng_getopt_bool(s1, NNG_OPT_RAW, &v) == 0);
-	TEST_CHECK(v == true);
-
-	TEST_CHECK(testutil_marry(s1, c1) == 0);
-	TEST_CHECK(testutil_marry(s1, c2) == 0);
-
-	// send/recv works
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	APPEND_STR(msg, "ONE");
-	TEST_CHECK(nng_sendmsg(c1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(s1, &msg, 0) == 0);
-	CHECK_STR(msg, "ONE");
-	p1 = nng_msg_get_pipe(msg);
-	TEST_CHECK(nng_pipe_id(p1) > 0);
-	TEST_CHECK(nng_msg_header_trim_u32(msg, &hops) == 0);
-	TEST_CHECK(hops == 1);
-	nng_msg_free(msg);
-
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	APPEND_STR(msg, "TWO");
-	TEST_CHECK(nng_sendmsg(c2, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(s1, &msg, 0) == 0);
-	CHECK_STR(msg, "TWO");
-	p2 = nng_msg_get_pipe(msg);
-	TEST_CHECK(nng_pipe_id(p2) > 0);
-	TEST_CHECK(nng_msg_header_trim_u32(msg, &hops) == 0);
-	TEST_CHECK(hops == 1);
-	nng_msg_free(msg);
-
-	TEST_CHECK(nng_pipe_id(p1) != nng_pipe_id(p2));
-
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	nng_msg_set_pipe(msg, p1);
-	APPEND_STR(msg, "UNO");
-	TEST_CHECK(nng_msg_header_append_u32(msg, 1) == 0);
-	TEST_CHECK(nng_sendmsg(s1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(c1, &msg, 0) == 0);
-	CHECK_STR(msg, "UNO");
-	nng_msg_free(msg);
-
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	nng_msg_set_pipe(msg, p2);
-	APPEND_STR(msg, "DOS");
-	TEST_CHECK(nng_msg_header_append_u32(msg, 1) == 0);
-	TEST_CHECK(nng_sendmsg(s1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(c2, &msg, 0) == 0);
-	CHECK_STR(msg, "DOS");
-	nng_msg_free(msg);
-
-	// Verify closing the pipe stops any of its traffic
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	APPEND_STR(msg, "ONE");
-	TEST_CHECK(nng_sendmsg(c1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(s1, &msg, 0) == 0);
-	CHECK_STR(msg, "ONE");
-	p1 = nng_msg_get_pipe(msg);
-	TEST_CHECK(nng_pipe_id(p1) > 0);
-	nng_msg_free(msg);
-
-	TEST_CHECK(nng_close(c1) == 0);
-
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	nng_msg_set_pipe(msg, p1);
-	APPEND_STR(msg, "EIN");
-	TEST_CHECK(nng_msg_header_append_u32(msg, 1) == 0);
-	TEST_CHECK(nng_sendmsg(s1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(c2, &msg, 0) == NNG_ETIMEDOUT);
+	TEST_NNG_PASS(nng_close(s1));
+	TEST_NNG_PASS(nng_close(c1));
 }
 
 void
-test_raw(void)
+test_pair1_raw(void)
 {
 	nng_socket s1;
 	bool       raw;
 
-	TEST_CHECK(nng_pair1_open(&s1) == 0);
-	TEST_CHECK(nng_getopt_bool(s1, NNG_OPT_RAW, &raw) == 0);
+	TEST_NNG_PASS(nng_pair1_open(&s1));
+	TEST_NNG_PASS(nng_getopt_bool(s1, NNG_OPT_RAW, &raw));
 	TEST_CHECK(raw == false);
-	TEST_CHECK(nng_setopt_bool(s1, NNG_OPT_RAW, true) == NNG_EREADONLY);
-	TEST_CHECK(nng_close(s1) == 0);
+	TEST_NNG_FAIL(nng_setopt_bool(s1, NNG_OPT_RAW, true), NNG_EREADONLY);
+	TEST_NNG_PASS(nng_close(s1));
 
-	TEST_CHECK(nng_pair1_open_raw(&s1) == 0);
-	TEST_CHECK(nng_getopt_bool(s1, NNG_OPT_RAW, &raw) == 0);
+	TEST_NNG_PASS(nng_pair1_open_raw(&s1));
+	TEST_NNG_PASS(nng_getopt_bool(s1, NNG_OPT_RAW, &raw));
 	TEST_CHECK(raw == true);
-	TEST_CHECK(nng_setopt_bool(s1, NNG_OPT_RAW, false) == NNG_EREADONLY);
-	TEST_CHECK(nng_close(s1) == 0);
+	TEST_NNG_FAIL(nng_setopt_bool(s1, NNG_OPT_RAW, false), NNG_EREADONLY);
+	TEST_NNG_PASS(nng_close(s1));
 }
 
 void
-test_ttl(void)
+test_pair1_ttl(void)
 {
 	nng_socket s1;
 	nng_socket c1;
@@ -537,69 +264,69 @@ test_ttl(void)
 	uint32_t   val;
 	int        ttl;
 
-	TEST_CHECK(nng_pair1_open_raw(&s1) == 0);
-	TEST_CHECK(nng_pair1_open_raw(&c1) == 0);
-	TEST_CHECK(nng_setopt_ms(s1, NNG_OPT_RECVTIMEO, SECOND / 5) == 0);
-	TEST_CHECK(nng_setopt_ms(c1, NNG_OPT_RECVTIMEO, SECOND / 5) == 0);
+	TEST_NNG_PASS(nng_pair1_open_raw(&s1));
+	TEST_NNG_PASS(nng_pair1_open_raw(&c1));
+	TEST_NNG_PASS(nng_setopt_ms(s1, NNG_OPT_RECVTIMEO, SECOND / 5));
+	TEST_NNG_PASS(nng_setopt_ms(c1, NNG_OPT_RECVTIMEO, SECOND / 5));
 
 	// cannot set insane TTLs
-	TEST_CHECK(nng_setopt_int(s1, NNG_OPT_MAXTTL, 0) == NNG_EINVAL);
-	TEST_CHECK(nng_setopt_int(s1, NNG_OPT_MAXTTL, 1000) == NNG_EINVAL);
+	TEST_NNG_FAIL(nng_setopt_int(s1, NNG_OPT_MAXTTL, 0), NNG_EINVAL);
+	TEST_NNG_FAIL(nng_setopt_int(s1, NNG_OPT_MAXTTL, 1000), NNG_EINVAL);
 	ttl = 8;
-	TEST_CHECK(nng_setopt(s1, NNG_OPT_MAXTTL, &ttl, 1) == NNG_EINVAL);
-	TEST_CHECK(nng_setopt_bool(s1, NNG_OPT_MAXTTL, true) == NNG_EBADTYPE);
+	TEST_NNG_FAIL(nng_setopt(s1, NNG_OPT_MAXTTL, &ttl, 1), NNG_EINVAL);
+	TEST_NNG_FAIL(nng_setopt_bool(s1, NNG_OPT_MAXTTL, true), NNG_EBADTYPE);
 
-	TEST_CHECK(testutil_marry(s1, c1) == 0);
+	TEST_NNG_PASS(testutil_marry(s1, c1));
 
 	// Let's check enforcement of TTL
-	TEST_CHECK(nng_setopt_int(s1, NNG_OPT_MAXTTL, 4) == 0);
-	TEST_CHECK(nng_getopt_int(s1, NNG_OPT_MAXTTL, &ttl) == 0);
+	TEST_NNG_PASS(nng_setopt_int(s1, NNG_OPT_MAXTTL, 4));
+	TEST_NNG_PASS(nng_getopt_int(s1, NNG_OPT_MAXTTL, &ttl));
 	TEST_CHECK(ttl == 4);
 
 	// Bad TTL bounces
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	TEST_CHECK(nng_msg_header_append_u32(msg, 4) == 0);
-	TEST_CHECK(nng_sendmsg(c1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(s1, &msg, 0) == NNG_ETIMEDOUT);
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	TEST_NNG_PASS(nng_msg_header_append_u32(msg, 4));
+	TEST_NNG_PASS(nng_sendmsg(c1, msg, 0));
+	TEST_NNG_FAIL(nng_recvmsg(s1, &msg, 0), NNG_ETIMEDOUT);
 
 	// Good TTL passes
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	TEST_CHECK(nng_msg_append_u32(msg, 0xFEEDFACE) == 0);
-	TEST_CHECK(nng_msg_header_append_u32(msg, 3) == 0);
-	TEST_CHECK(nng_sendmsg(c1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(s1, &msg, 0) == 0);
-	TEST_CHECK(nng_msg_trim_u32(msg, &val) == 0);
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	TEST_NNG_PASS(nng_msg_append_u32(msg, 0xFEEDFACE));
+	TEST_NNG_PASS(nng_msg_header_append_u32(msg, 3));
+	TEST_NNG_PASS(nng_sendmsg(c1, msg, 0));
+	TEST_NNG_PASS(nng_recvmsg(s1, &msg, 0));
+	TEST_NNG_PASS(nng_msg_trim_u32(msg, &val));
 	TEST_CHECK(val == 0xFEEDFACE);
-	TEST_CHECK(nng_msg_header_trim_u32(msg, &val) == 0);
+	TEST_NNG_PASS(nng_msg_header_trim_u32(msg, &val));
 	TEST_CHECK(val == 4);
 	nng_msg_free(msg);
 
 	// Large TTL passes
-	TEST_CHECK(nng_setopt_int(s1, NNG_OPT_MAXTTL, 15) == 0);
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	TEST_CHECK(nng_msg_append_u32(msg, 1234) == 0);
-	TEST_CHECK(nng_msg_header_append_u32(msg, 14) == 0);
-	TEST_CHECK(nng_sendmsg(c1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(s1, &msg, 0) == 0);
-	TEST_CHECK(nng_msg_trim_u32(msg, &val) == 0);
+	TEST_NNG_PASS(nng_setopt_int(s1, NNG_OPT_MAXTTL, 15));
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	TEST_NNG_PASS(nng_msg_append_u32(msg, 1234));
+	TEST_NNG_PASS(nng_msg_header_append_u32(msg, 14));
+	TEST_NNG_PASS(nng_sendmsg(c1, msg, 0));
+	TEST_NNG_PASS(nng_recvmsg(s1, &msg, 0));
+	TEST_NNG_PASS(nng_msg_trim_u32(msg, &val));
 	TEST_CHECK(val == 1234);
-	TEST_CHECK(nng_msg_header_trim_u32(msg, &val) == 0);
+	TEST_NNG_PASS(nng_msg_header_trim_u32(msg, &val));
 	TEST_CHECK(val == 15);
 	nng_msg_free(msg);
 
 	// Max TTL fails
-	TEST_CHECK(nng_setopt_int(s1, NNG_OPT_MAXTTL, 15) == 0);
-	TEST_CHECK(nng_msg_alloc(&msg, 0) == 0);
-	TEST_CHECK(nng_msg_header_append_u32(msg, 15) == 0);
-	TEST_CHECK(nng_sendmsg(c1, msg, 0) == 0);
-	TEST_CHECK(nng_recvmsg(s1, &msg, 0) == NNG_ETIMEDOUT);
-
-	TEST_CHECK(nng_close(s1) == 0);
-	TEST_CHECK(nng_close(c1) == 0);
+	TEST_NNG_PASS(nng_setopt_int(s1, NNG_OPT_MAXTTL, 15));
+	TEST_NNG_PASS(nng_msg_alloc(&msg, 0));
+	TEST_NNG_PASS(nng_msg_header_append_u32(msg, 15));
+	TEST_NNG_PASS(nng_sendmsg(c1, msg, 0));
+	TEST_NNG_FAIL(nng_recvmsg(s1, &msg, 0), NNG_ETIMEDOUT);
+
+	TEST_NNG_PASS(nng_close(s1));
+	TEST_NNG_PASS(nng_close(c1));
 }
 
 void
-test_validate_peer(void)
+test_pair1_validate_peer(void)
 {
 	nng_socket s1, s2;
 	nng_stat * stats;
@@ -629,20 +356,65 @@ test_validate_peer(void)
 	nng_stats_free(stats);
 }
 
+void
+test_pair1_recv_no_header(void)
+{
+	nng_socket s;
+	nng_socket c;
+	nng_msg *  m;
+
+	TEST_NNG_PASS(nng_pair1_open(&s));
+	TEST_NNG_PASS(nng_pair1_open(&c));
+	TEST_NNG_PASS(nng_setopt_bool(c, "pair1_test_inject_header", true));
+	TEST_NNG_PASS(nng_setopt_ms(s, NNG_OPT_RECVTIMEO, 100));
+	TEST_NNG_PASS(nng_setopt_ms(s, NNG_OPT_SENDTIMEO, 200));
+
+	TEST_NNG_PASS(testutil_marry(c, s));
+
+	TEST_NNG_PASS(nng_msg_alloc(&m, 0));
+	TEST_NNG_PASS(nng_sendmsg(c, m, 0));
+	TEST_NNG_FAIL(nng_recvmsg(s, &m, 0), NNG_ETIMEDOUT);
+
+	TEST_NNG_PASS(nng_close(c));
+	TEST_NNG_PASS(nng_close(s));
+}
+
+void
+test_pair1_recv_garbage(void)
+{
+	nng_socket s;
+	nng_socket c;
+	nng_msg *  m;
+
+	TEST_NNG_PASS(nng_pair1_open(&s));
+	TEST_NNG_PASS(nng_pair1_open(&c));
+	TEST_NNG_PASS(nng_setopt_bool(c, "pair1_test_inject_header", true));
+	TEST_NNG_PASS(nng_setopt_ms(s, NNG_OPT_RECVTIMEO, 100));
+	TEST_NNG_PASS(nng_setopt_ms(s, NNG_OPT_SENDTIMEO, 200));
+
+	TEST_NNG_PASS(testutil_marry(c, s));
+
+	// ridiculous hop count
+	TEST_NNG_PASS(nng_msg_alloc(&m, 0));
+	TEST_NNG_PASS(nng_msg_append_u32(m, 0x1000));
+	TEST_NNG_PASS(nng_sendmsg(c, m, 0));
+	TEST_NNG_FAIL(nng_recvmsg(s, &m, 0), NNG_ETIMEDOUT);
+
+	TEST_NNG_PASS(nng_close(c));
+	TEST_NNG_PASS(nng_close(s));
+}
+
 TEST_LIST = {
 	{ "pair1 monogamous cooked", test_mono_cooked },
 	{ "pair1 monogamous faithful", test_mono_faithful },
 	{ "pair1 monogamous back pressure", test_mono_back_pressure },
 	{ "pair1 monogamous raw exchange", test_mono_raw_exchange },
 	{ "pair1 monogamous raw header", test_mono_raw_header },
-	{ "pair1 polyamorous best effort", test_poly_best_effort },
-	{ "pair1 polyamorous cooked", test_poly_cooked },
-	{ "pair1 polyamorous late", test_poly_late },
-	{ "pair1 polyamorous default", test_poly_default },
-	{ "pair1 polyamorous raw", test_poly_raw },
-	{ "pair1 raw", test_raw },
-	{ "pair1 ttl", test_ttl },
-	{ "pair1 validate peer", test_validate_peer },
+	{ "pair1 raw", test_pair1_raw },
+	{ "pair1 ttl", test_pair1_ttl },
+	{ "pair1 validate peer", test_pair1_validate_peer },
+	{ "pair1 recv no header", test_pair1_recv_no_header },
+	{ "pair1 recv garbage", test_pair1_recv_garbage },
 
 	{ NULL, NULL },
 };