fixes #848 server hang waiting for client handshake

fixes #698 Need TCP stats
fixes #699 Need IPC stats
fixes #701 Need TLS stats

This commit addresses a problem when negotiating using one of the stream
based negotiation APIs -- a slow or misbehaving peer can prevent well
behaved ones from establishing a connection.  The fix is a fairly
significant change in how these transports link up, and it does rely
on the fact that the socket only has a single accept() or connect()
pending at a time (on a given endpoint that is).

While here, we have completely revamped the way transport statistics are
done, offering a standard API for collecting these statistics.

Unfortunately, this completely borks the statistics for inproc.  As we
are planning to change the way inproc works soon, in order to provide
more control and work on performance fixes for the message queue, we feel
this is an acceptable trade-off.  Furthermore, almost nobody uses inproc
for anything, and even fewer people are making use of the statistics
at this time.

1 files changed, 55 insertions, 21 deletions

diff --git a/src/core/dialer.c b/src/core/dialer.c
index f0589275..ffbef8a7 100644
--- a/src/core/dialer.c
+++ b/src/core/dialer.c
@@ -1,5 +1,5 @@
 //
-// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2019 Staysail Systems, Inc. <info@staysail.tech>
 // Copyright 2018 Capitar IT Group BV <info@capitar.com>
 // Copyright 2018 Devolutions <info@devolutions.net>
 //
@@ -94,31 +94,69 @@ dialer_stats_init(nni_dialer *d)
 	nni_stat_init_atomic(&st->s_npipes, "npipes", "open pipes");
 	nni_stat_append(root, &st->s_npipes);
 
-	nni_stat_init_atomic(&st->s_connok, "connok", "connections made");
-	nni_stat_append(root, &st->s_connok);
-
 	nni_stat_init_atomic(
-	    &st->s_canceled, "canceled", "connections canceled");
-	nni_stat_append(root, &st->s_canceled);
+	    &st->s_connok, "connect", "connections established");
+	nni_stat_append(root, &st->s_connok);
 
 	nni_stat_init_atomic(&st->s_refused, "refused", "connections refused");
 	nni_stat_append(root, &st->s_refused);
 
-	nni_stat_init_atomic(
-	    &st->s_timedout, "timedout", "connections timed out");
-	nni_stat_append(root, &st->s_timedout);
+	nni_stat_init_atomic(&st->s_discon, "discon", "remote disconnects");
+	nni_stat_append(root, &st->s_discon);
 
-	nni_stat_init_atomic(
-	    &st->s_othererr, "othererr", "other connection errors");
+	nni_stat_init_atomic(&st->s_canceled, "canceled", "canceled");
+	nni_stat_append(root, &st->s_canceled);
+
+	nni_stat_init_atomic(&st->s_othererr, "othererr", "other errors");
 	nni_stat_append(root, &st->s_othererr);
 
-	nni_stat_init_atomic(
-	    &st->s_protorej, "protoreject", "pipes rejected by protocol");
-	nni_stat_append(root, &st->s_protorej);
+	nni_stat_init_atomic(&st->s_etimedout, "timedout", "timed out");
+	nni_stat_append(root, &st->s_etimedout);
 
-	nni_stat_init_atomic(
-	    &st->s_apprej, "appreject", "pipes rejected by application");
-	nni_stat_append(root, &st->s_apprej);
+	nni_stat_init_atomic(&st->s_eproto, "protoerr", "protcol errors");
+	nni_stat_append(root, &st->s_eproto);
+
+	nni_stat_init_atomic(&st->s_eauth, "autherr", "auth errors");
+	nni_stat_append(root, &st->s_eauth);
+
+	nni_stat_init_atomic(&st->s_enomem, "nomem", "out of memory");
+	nni_stat_append(root, &st->s_enomem);
+
+	nni_stat_init_atomic(&st->s_reject, "reject", "pipes rejected");
+	nni_stat_append(root, &st->s_reject);
+}
+
+void
+nni_dialer_bump_error(nni_dialer *d, int err)
+{
+	switch (err) {
+	case NNG_ECONNABORTED:
+	case NNG_ECONNRESET:
+		BUMPSTAT(&d->d_stats.s_discon);
+		break;
+	case NNG_ECONNREFUSED:
+		BUMPSTAT(&d->d_stats.s_refused);
+		break;
+	case NNG_ECANCELED:
+		BUMPSTAT(&d->d_stats.s_canceled);
+		break;
+	case NNG_ETIMEDOUT:
+		BUMPSTAT(&d->d_stats.s_etimedout);
+		break;
+	case NNG_EPROTO:
+		BUMPSTAT(&d->d_stats.s_eproto);
+		break;
+	case NNG_EPEERAUTH:
+	case NNG_ECRYPTO:
+		BUMPSTAT(&d->d_stats.s_eauth);
+		break;
+	case NNG_ENOMEM:
+		BUMPSTAT(&d->d_stats.s_enomem);
+		break;
+	default:
+		BUMPSTAT(&d->d_stats.s_othererr);
+		break;
+	}
 }
 
 int
@@ -304,10 +342,8 @@ dialer_connect_cb(void *arg)
 		break;
 	case NNG_ECLOSED:   // No further action.
 	case NNG_ECANCELED: // No further action.
-		BUMPSTAT(&d->d_stats.s_canceled);
 		break;
 	case NNG_ECONNREFUSED:
-		BUMPSTAT(&d->d_stats.s_refused);
 		if (uaio == NULL) {
 			nni_dialer_timer_start(d);
 		} else {
@@ -316,7 +352,6 @@ dialer_connect_cb(void *arg)
 		break;
 
 	case NNG_ETIMEDOUT:
-		BUMPSTAT(&d->d_stats.s_timedout);
 		if (uaio == NULL) {
 			nni_dialer_timer_start(d);
 		} else {
@@ -325,7 +360,6 @@ dialer_connect_cb(void *arg)
 		break;
 
 	default:
-		BUMPSTAT(&d->d_stats.s_othererr);
 		if (uaio == NULL) {
 			nni_dialer_timer_start(d);
 		} else {