From cf9a72d8dbe463c0b87a448fc5843b0891154bd3 Mon Sep 17 00:00:00 2001
From: "Roger A. Light" <roger@atchoo.org>
Date: Thu, 27 Sep 2018 22:05:15 +0100
Subject: [PATCH] Add mosquitto_subscribe_multiple.

---
 lib/actions.c        | 19 ++++++++++++++++++-
 lib/linker.version   |  5 +++++
 lib/mosquitto.h      | 24 ++++++++++++++++++++++++
 lib/send_mosq.h      |  2 +-
 lib/send_subscribe.c | 21 ++++++++++++++-------
 src/handle_connack.c |  2 +-
 6 files changed, 63 insertions(+), 10 deletions(-)

diff --git a/lib/actions.c b/lib/actions.c
index 5e50dbe5..5883fc70 100644
--- a/lib/actions.c
+++ b/lib/actions.c
@@ -105,7 +105,24 @@ int mosquitto_subscribe(struct mosquitto *mosq, int *mid, const char *sub, int q
 	if(mosquitto_sub_topic_check(sub)) return MOSQ_ERR_INVAL;
 	if(mosquitto_validate_utf8(sub, strlen(sub))) return MOSQ_ERR_MALFORMED_UTF8;
 
-	return send__subscribe(mosq, mid, sub, qos);
+	return send__subscribe(mosq, mid, 1, &sub, qos);
+}
+
+
+int mosquitto_subscribe_multiple(struct mosquitto *mosq, int *mid, int sub_count, const char **sub, int qos)
+{
+	int i;
+
+	if(!mosq || !sub_count || !sub) return MOSQ_ERR_INVAL;
+	if(qos < 0 || qos > 2) return MOSQ_ERR_INVAL;
+	if(mosq->sock == INVALID_SOCKET) return MOSQ_ERR_NO_CONN;
+
+	for(i=0; i<sub_count; i++){
+		if(mosquitto_sub_topic_check(sub[i])) return MOSQ_ERR_INVAL;
+		if(mosquitto_validate_utf8(sub[i], strlen(sub[i]))) return MOSQ_ERR_MALFORMED_UTF8;
+	}
+
+	return send__subscribe(mosq, mid, sub_count, sub, qos);
 }
 
 
diff --git a/lib/linker.version b/lib/linker.version
index c592d17e..fb18c049 100644
--- a/lib/linker.version
+++ b/lib/linker.version
@@ -91,3 +91,8 @@ MOSQ_1.5 {
 		mosquitto_topic_matches_sub2;
 		mosquitto_connect_with_flags_callback_set;
 } MOSQ_1.4;
+
+MOSQ_1.6 {
+	global:
+		mosquitto_subscribe_multiple;
+} MOSQ_1.5;
diff --git a/lib/mosquitto.h b/lib/mosquitto.h
index e67a2b34..f51baede 100644
--- a/lib/mosquitto.h
+++ b/lib/mosquitto.h
@@ -630,6 +630,30 @@ libmosq_EXPORT int mosquitto_publish(struct mosquitto *mosq, int *mid, const cha
  */
 libmosq_EXPORT int mosquitto_subscribe(struct mosquitto *mosq, int *mid, const char *sub, int qos);
 
+/*
+ * Function: mosquitto_subscribe_multiple
+ *
+ * Subscribe to multiple topics.
+ *
+ * Parameters:
+ *	mosq - a valid mosquitto instance.
+ *	mid -  a pointer to an int. If not NULL, the function will set this to
+ *	       the message id of this particular message. This can be then used
+ *	       with the subscribe callback to determine when the message has been
+ *	       sent.
+ *  sub_count - the count of subscriptions to be made
+ *	sub -  array of sub_count pointers, each pointing to a subscription string.
+ *	qos -  the requested Quality of Service for each subscription.
+ *
+ * Returns:
+ *	MOSQ_ERR_SUCCESS -        on success.
+ * 	MOSQ_ERR_INVAL -          if the input parameters were invalid.
+ * 	MOSQ_ERR_NOMEM -          if an out of memory condition occurred.
+ * 	MOSQ_ERR_NO_CONN -        if the client isn't connected to a broker.
+ * 	MOSQ_ERR_MALFORMED_UTF8 - if a topic is not valid UTF-8
+ */
+int mosquitto_subscribe_multiple(struct mosquitto *mosq, int *mid, int sub_count, const char **sub, int qos);
+
 /*
  * Function: mosquitto_unsubscribe
  *
diff --git a/lib/send_mosq.h b/lib/send_mosq.h
index db287fcd..c04f3c3f 100644
--- a/lib/send_mosq.h
+++ b/lib/send_mosq.h
@@ -31,7 +31,7 @@ int send__pubcomp(struct mosquitto *mosq, uint16_t mid);
 int send__publish(struct mosquitto *mosq, uint16_t mid, const char *topic, uint32_t payloadlen, const void *payload, int qos, bool retain, bool dup);
 int send__pubrec(struct mosquitto *mosq, uint16_t mid);
 int send__pubrel(struct mosquitto *mosq, uint16_t mid);
-int send__subscribe(struct mosquitto *mosq, int *mid, const char *topic, uint8_t topic_qos);
+int send__subscribe(struct mosquitto *mosq, int *mid, int topic_count, const char **topic, int topic_qos);
 int send__unsubscribe(struct mosquitto *mosq, int *mid, const char *topic);
 
 #endif
diff --git a/lib/send_subscribe.c b/lib/send_subscribe.c
index ef0de606..c8745639 100644
--- a/lib/send_subscribe.c
+++ b/lib/send_subscribe.c
@@ -30,13 +30,13 @@ Contributors:
 #include "util_mosq.h"
 
 
-int send__subscribe(struct mosquitto *mosq, int *mid, const char *topic, uint8_t topic_qos)
+int send__subscribe(struct mosquitto *mosq, int *mid, int topic_count, const char **topic, int topic_qos)
 {
-	/* FIXME - only deals with a single topic */
 	struct mosquitto__packet *packet = NULL;
 	uint32_t packetlen;
 	uint16_t local_mid;
 	int rc;
+	int i;
 
 	assert(mosq);
 	assert(topic);
@@ -44,7 +44,10 @@ int send__subscribe(struct mosquitto *mosq, int *mid, const char *topic, uint8_t
 	packet = mosquitto__calloc(1, sizeof(struct mosquitto__packet));
 	if(!packet) return MOSQ_ERR_NOMEM;
 
-	packetlen = 2 + 2+strlen(topic) + 1;
+	packetlen = 2;
+	for(i=0; i<topic_count; i++){
+		packetlen += 2+strlen(topic[i]) + 1;
+	}
 
 	packet->command = SUBSCRIBE | (1<<1);
 	packet->remaining_length = packetlen;
@@ -60,15 +63,19 @@ int send__subscribe(struct mosquitto *mosq, int *mid, const char *topic, uint8_t
 	packet__write_uint16(packet, local_mid);
 
 	/* Payload */
-	packet__write_string(packet, topic, strlen(topic));
-	packet__write_byte(packet, topic_qos);
+	for(i=0; i<topic_count; i++){
+		packet__write_string(packet, topic[i], strlen(topic[i]));
+		packet__write_byte(packet, topic_qos);
+	}
 
 #ifdef WITH_BROKER
 # ifdef WITH_BRIDGE
-	log__printf(mosq, MOSQ_LOG_DEBUG, "Bridge %s sending SUBSCRIBE (Mid: %d, Topic: %s, QoS: %d)", mosq->id, local_mid, topic, topic_qos);
+	log__printf(mosq, MOSQ_LOG_DEBUG, "Bridge %s sending SUBSCRIBE (Mid: %d, Topic: %s, QoS: %d)", mosq->id, local_mid, topic[0], topic_qos);
 # endif
 #else
-	log__printf(mosq, MOSQ_LOG_DEBUG, "Client %s sending SUBSCRIBE (Mid: %d, Topic: %s, QoS: %d)", mosq->id, local_mid, topic, topic_qos);
+	for(i=0; i<topic_count; i++){
+		log__printf(mosq, MOSQ_LOG_DEBUG, "Client %s sending SUBSCRIBE (Mid: %d, Topic: %s, QoS: %d)", mosq->id, local_mid, topic[i], topic_qos);
+	}
 #endif
 
 	return packet__queue(mosq, packet);
diff --git a/src/handle_connack.c b/src/handle_connack.c
index 14b053eb..3194a61a 100644
--- a/src/handle_connack.c
+++ b/src/handle_connack.c
@@ -75,7 +75,7 @@ int handle__connack(struct mosquitto_db *db, struct mosquitto *context)
 				}
 				for(i=0; i<context->bridge->topic_count; i++){
 					if(context->bridge->topics[i].direction == bd_in || context->bridge->topics[i].direction == bd_both){
-						if(send__subscribe(context, NULL, context->bridge->topics[i].remote_topic, context->bridge->topics[i].qos)){
+						if(send__subscribe(context, NULL, 1, &context->bridge->topics[i].remote_topic, &context->bridge->topics[i].qos)){
 							return 1;
 						}
 					}else{