From 4398deb2d4e8cbe98139892b7fefd8a73a98b819 Mon Sep 17 00:00:00 2001
From: Ian Gulliver <flamingcow@gmail.com>
Date: Wed, 17 Feb 2016 22:14:04 -0800
Subject: [PATCH] Working model for triggering reconnects on outgoing
 connections.

---
 outgoing.c | 20 ++++++++++++++++++--
 receive.c  |  2 --
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/outgoing.c b/outgoing.c
index b2e3755..2bc4606 100644
--- a/outgoing.c
+++ b/outgoing.c
@@ -22,11 +22,13 @@ struct outgoing {
 };
 
 static void outgoing_connect_result(struct outgoing *, int);
+static void outgoing_resolve(struct outgoing *);
 
 static void outgoing_connect_next(struct outgoing *outgoing) {
 	if (outgoing->addr == NULL) {
 		freeaddrinfo(outgoing->addrs);
 		fprintf(stderr, "O %s: Can't connect to any addresses of %s/%s\n", outgoing->id, outgoing->node, outgoing->service);
+		// TODO: timed retry
 		return;
 	}
 
@@ -44,7 +46,7 @@ static void outgoing_connect_next(struct outgoing *outgoing) {
 static void outgoing_connect_handler(struct peer *peer) {
 	struct outgoing *outgoing = (struct outgoing *) peer;
 
-	peer_epoll_del(peer);
+	peer_epoll_del(&outgoing->peer);
 
 	int error;
   socklen_t len = sizeof(error);
@@ -52,6 +54,14 @@ static void outgoing_connect_handler(struct peer *peer) {
 	outgoing_connect_result(outgoing, error);
 }
 
+static void outgoing_disconnect_handler(struct peer *peer) {
+	struct outgoing *outgoing = (struct outgoing *) peer;
+	close(outgoing->peer.fd);
+	fprintf(stderr, "O %s: Peer disconnected; reconnecting...\n", outgoing->id);
+
+	outgoing_resolve(outgoing);
+}
+
 static void outgoing_connect_result(struct outgoing *outgoing, int result) {
 	char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
 	assert(getnameinfo(outgoing->addr->ai_addr, outgoing->addr->ai_addrlen, hbuf, sizeof(hbuf), sbuf, sizeof(sbuf), NI_NUMERICHOST | NI_NUMERICSERV) == 0);
@@ -59,7 +69,12 @@ static void outgoing_connect_result(struct outgoing *outgoing, int result) {
 		case 0:
 			fprintf(stderr, "O %s: Connected to %s/%s\n", outgoing->id, hbuf, sbuf);
 			freeaddrinfo(outgoing->addrs);
-			outgoing->handler(outgoing->peer.fd, outgoing->passthrough);
+
+			// We listen for just hangup on this fd. We pass a duplicate to the handler, so our epoll setings are independent.
+			outgoing->peer.event_handler = outgoing_disconnect_handler;
+			peer_epoll_add((struct peer *) outgoing, EPOLLRDHUP);
+
+			outgoing->handler(dup(outgoing->peer.fd), outgoing->passthrough);
 			break;
 
 		case EINPROGRESS:
@@ -88,6 +103,7 @@ static void outgoing_resolve(struct outgoing *outgoing) {
 	int gai_err = getaddrinfo(outgoing->node, outgoing->service, &hints, &outgoing->addrs);
 	if (gai_err) {
 		fprintf(stderr, "O %s: Failed to resolve %s/%s: %s\n", outgoing->id, outgoing->node, outgoing->service, gai_strerror(gai_err));
+		// TODO: timed retry
 		return;
 	}
 	outgoing->addr = outgoing->addrs;
diff --git a/receive.c b/receive.c
index 3f33701..c712b82 100644
--- a/receive.c
+++ b/receive.c
@@ -67,7 +67,6 @@ static void receive_read(struct peer *peer) {
 	if (buf_fill(&receive->buf, receive->peer.fd) <= 0) {
 		fprintf(stderr, "R %s: Connection closed by peer\n", receive->id);
 		close(receive->peer.fd);
-		// TODO: reconnect
 		return;
 	}
 
@@ -79,7 +78,6 @@ static void receive_read(struct peer *peer) {
 	if (receive->buf.length == BUF_LEN_MAX) {
 		fprintf(stderr, "R %s: Input buffer overrun. This probably means that adsbus doesn't understand the protocol that this source is speaking.\n", receive->id);
 		close(receive->peer.fd);
-		// TODO: reconnect
 		return;
 	}
 }