From e169f1c7c2d190c5dadd1f7d7e5d7c874d58ad1b Mon Sep 17 00:00:00 2001
From: "Roger A. Light" <roger@atchoo.org>
Date: Tue, 4 Dec 2018 12:39:00 +0000
Subject: [PATCH] When using ADNS, don't ask for all network protocols when
 connecting.

This can lead to confusing "Protocol not supported" errors if the
network is down, because UDP sockets are provided.

Thanks to jsaak.

Closes #1062.

Bug: https://github.com/eclipse/mosquitto/issues/1062
---
 ChangeLog.txt  |  3 +++
 lib/net_mosq.c | 23 +++++++++++++++++++++--
 src/context.c  |  7 +++++++
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/ChangeLog.txt b/ChangeLog.txt
index cfe54fc2..953a2b3c 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -6,6 +6,9 @@ Broker:
   This is required to work around a problem in libwebsockets that means
   sockets only listen on IPv6 by default if IPv6 support is compiled in.
   Closes #1004.
+- When using ADNS, don't ask for all network protocols when connecting,
+  because this can lead to confusing "Protocol not supported" errors if the
+  network is down. Closes #1062.
 
 Client:
 - Always print leading zeros in mosquitto_sub when output format is hex.
diff --git a/lib/net_mosq.c b/lib/net_mosq.c
index 4efda3d2..f2bb628b 100644
--- a/lib/net_mosq.c
+++ b/lib/net_mosq.c
@@ -208,21 +208,39 @@ int net__try_connect_step1(struct mosquitto *mosq, const char *host)
 {
 	int s;
 	void *sevp = NULL;
+	struct addrinfo *hints;
 
 	if(mosq->adns){
+		gai_cancel(mosq->adns);
+		mosquitto__free((struct addrinfo *)mosq->adns->ar_request);
 		mosquitto__free(mosq->adns);
 	}
 	mosq->adns = mosquitto__calloc(1, sizeof(struct gaicb));
 	if(!mosq->adns){
 		return MOSQ_ERR_NOMEM;
 	}
+
+	hints = mosquitto__calloc(1, sizeof(struct addrinfo));
+	if(!hints){
+		mosquitto__free(mosq->adns);
+		mosq->adns = NULL;
+		return MOSQ_ERR_NOMEM;
+	}
+
+	hints->ai_family = AF_UNSPEC;
+	hints->ai_socktype = SOCK_STREAM;
+
 	mosq->adns->ar_name = host;
+	mosq->adns->ar_request = hints;
 
 	s = getaddrinfo_a(GAI_NOWAIT, &mosq->adns, 1, sevp);
 	if(s){
 		errno = s;
-		mosquitto__free(mosq->adns);
-		mosq->adns = NULL;
+		if(mosq->adns){
+			mosquitto__free((struct addrinfo *)mosq->adns->ar_request);
+			mosquitto__free(mosq->adns);
+			mosq->adns = NULL;
+		}
 		return MOSQ_ERR_EAI;
 	}
 
@@ -278,6 +296,7 @@ int net__try_connect_step2(struct mosquitto *mosq, uint16_t port, mosq_sock_t *s
 	freeaddrinfo(mosq->adns->ar_result);
 	mosq->adns->ar_result = NULL;
 
+	mosquitto__free((struct addrinfo *)mosq->adns->ar_request);
 	mosquitto__free(mosq->adns);
 	mosq->adns = NULL;
 
diff --git a/src/context.c b/src/context.c
index 1d3ae163..e8cbfdfc 100644
--- a/src/context.c
+++ b/src/context.c
@@ -197,6 +197,13 @@ void context__cleanup(struct mosquitto_db *db, struct mosquitto *context, bool d
 		context->queued_msgs = NULL;
 		context->last_queued_msg = NULL;
 	}
+#if defined(WITH_BROKER) && defined(__GLIBC__) && defined(WITH_ADNS)
+	if(context->adns){
+		gai_cancel(context->adns);
+		mosquitto__free((struct addrinfo *)context->adns->ar_request);
+		mosquitto__free(context->adns);
+	}
+#endif
 	if(do_free){
 		mosquitto__free(context);
 	}