1 files changed, 137 insertions, 0 deletions
diff --git a/src/core/device.c b/src/core/device.c
new file mode 100644
index 00000000..7b2b5b87
--- /dev/null
+++ b/src/core/device.c
@@ -0,0 +1,137 @@
+//
+// Copyright 2017 Garrett D'Amore <garrett@damore.org>
+//
+// 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 "core/nng_impl.h"
+
+#include <string.h>
+
+struct nni_device_pair {
+	nni_thr		thrs[2];
+	nni_sock *	socks[2];
+	int		err[2];
+};
+
+typedef struct nni_device_pair   nni_device_pair;
+
+static int
+nni_device_loop(nni_sock *from, nni_sock *to)
+{
+	nni_msg *msg;
+	int rv = 0;
+
+	for (;;) {
+		// Take messages sock[0], and send to sock[1].
+		// If an error occurs, we close both sockets.
+		if ((rv = nni_sock_recvmsg(from, &msg, NNI_TIME_NEVER)) != 0) {
+			break;
+		}
+		if ((rv = nni_sock_sendmsg(to, msg, NNI_TIME_NEVER)) != 0) {
+			nni_msg_free(msg);
+			break;
+		}
+	}
+
+	return (rv);
+}
+
+
+static void
+nni_device_fwd(void *p)
+{
+	nni_device_pair *pair = p;
+
+	pair->err[0] = nni_device_loop(pair->socks[0], pair->socks[1]);
+	nni_sock_shutdown(pair->socks[0]);
+	nni_sock_shutdown(pair->socks[1]);
+}
+
+
+static void
+nni_device_rev(void *p)
+{
+	nni_device_pair *pair = p;
+	int rv;
+
+	pair->err[1] = nni_device_loop(pair->socks[1], pair->socks[0]);
+	nni_sock_shutdown(pair->socks[0]);
+	nni_sock_shutdown(pair->socks[1]);
+}
+
+
+int
+nni_device(nni_sock *sock1, nni_sock *sock2)
+{
+	nni_device_pair pair;
+	int rv;
+
+	memset(&pair, 0, sizeof (pair));
+	pair.socks[0] = sock1;
+	pair.socks[1] = sock2;
+
+	if (sock1 == NULL) {
+		sock1 = sock2;
+	}
+	if (sock2 == NULL) {
+		sock2 = sock1;
+	}
+	if ((sock1 == NULL) || (sock2 == NULL)) {
+		rv = NNG_EINVAL;
+		goto out;
+	}
+	if ((sock1->s_peer != sock2->s_protocol) ||
+	    (sock2->s_peer != sock1->s_protocol)) {
+		rv = NNG_EINVAL;
+		goto out;
+	}
+
+	pair.socks[0] = sock1;
+	pair.socks[1] = sock2;
+
+	if ((rv = nni_thr_init(&pair.thrs[0], nni_device_fwd, &pair)) != 0) {
+		goto out;
+	}
+	if ((rv = nni_thr_init(&pair.thrs[1], nni_device_rev, &pair)) != 0) {
+		nni_thr_fini(&pair.thrs[0]);
+		goto out;
+	}
+	if (((sock1->s_flags & NNI_PROTO_FLAG_RCV) != 0) &&
+	    ((sock2->s_flags & NNI_PROTO_FLAG_SND) != 0)) {
+		nni_thr_run(&pair.thrs[0]);
+	}
+	// If the sockets are the same, then its a simple one way forwarder,
+	// and we don't need two workers (but would be harmless if we did it).
+	if ((sock1 != sock2) &&
+	    ((sock2->s_flags & NNI_PROTO_FLAG_RCV) != 0) &&
+	    ((sock1->s_flags & NNI_PROTO_FLAG_SND) != 0)) {
+		nni_thr_run(&pair.thrs[1]);
+	}
+
+	// This blocks on both threads (though if we didn't start one, that
+	// will return immediately.)
+	nni_thr_fini(&pair.thrs[0]);
+	nni_thr_fini(&pair.thrs[1]);
+
+	nni_sock_rele(sock1);
+	if (sock1 != sock2) {
+		nni_sock_rele(sock2);
+	}
+
+	rv = pair.err[0];
+	if (rv == 0) {
+		rv = pair.err[1];
+	}
+	if (rv == 0) {
+		// This can happen if neither thread ran.  Shouldn't happen
+		// really.
+		rv = NNG_EINVAL;
+	}
+
+out:
+	return (rv);
+}