Fix copy of uint16_t to buff, destination may not be aligned on word boundary.

diff --git a/lib/protocols/mqtt.c b/lib/protocols/mqtt.c
index a781b44..36cd5fe 100644 (file)
--- a/lib/protocols/mqtt.c
+++ b/lib/protocols/mqtt.c
@@ -90,7 +90,8 @@ static int decode_remaining_length(uint8_t* buf, uint32_t* length)
  */
 static int mqtt_pack_str(uint8_t *buf, char* str, uint16_t len)
 {
-       *(uint16_t*)buf = htons(len);
+       uint16_t tmp = htons(len);
+       memcpy(buf, &tmp, 2);
        memcpy((buf + 2), str, len);
        return len + 2;
 }
@@ -181,8 +182,9 @@ int mqtt_pack_connect_packet(const struct mqtt_connect_pkt* pkt, uint8_t* buf, u
 
        /* Add optionnal Will message */
        if ((pkt->will_msg_size != 0) && (pkt->will_topic != NULL) && (pkt->will_msg != NULL)) {
+               uint16_t tmp = htons(pkt->will_msg_size);
                len += mqtt_pack_str((buf + len), pkt->will_topic, will_topic_len);
-               *(uint16_t*)(buf + len) = htons(pkt->will_msg_size);
+               memcpy((buf + len), &tmp, 2);
                memcpy((buf + len + 2), pkt->will_msg, pkt->will_msg_size);
                len += pkt->will_msg_size + 2;
        }
@@ -240,6 +242,7 @@ int mqtt_pack_publish_packet(const struct mqtt_publish_pkt* pkt, uint8_t* buf, u
        uint32_t remaining_length = 0;
        uint32_t len = 0;
        uint16_t topic_len = 0;
+       uint16_t tmp_packet_id = 0;
        uint8_t publish_flags = 0;
 
        if ((pkt == NULL) || (buf == NULL)) {
@@ -280,7 +283,8 @@ int mqtt_pack_publish_packet(const struct mqtt_publish_pkt* pkt, uint8_t* buf, u
        /* Topic is mandatory */
        len += mqtt_pack_str((buf + len), pkt->topic, topic_len);
        /* Packet ID */
-       *(uint16_t*)(buf + len) = htons(pkt->packet_id);
+       tmp_packet_id = htons(pkt->packet_id);
+       memcpy((buf + len), &tmp_packet_id, 2);
        len += 2;
        /* Add optionnal application message */
        if (pkt->message_size != 0) {
@@ -351,6 +355,7 @@ int mqtt_unpack_publish_packet(struct mqtt_publish_pkt* pkt, uint8_t* buf, uint3
  */
 int mqtt_pack_publish_response_pkt(uint8_t* buf, uint16_t acked_pkt_id, uint8_t type)
 {
+       uint16_t tmp_acked_pkt_id = 0;
        if (buf == NULL) {
                return -EINVAL;
        }
@@ -359,7 +364,8 @@ int mqtt_pack_publish_response_pkt(uint8_t* buf, uint16_t acked_pkt_id, uint8_t
                buf[0] |= MQTT_PUBREL_FLAG;
        }
        buf[1] = 0x02;
-       *(uint16_t*)(buf + 2) = htons(acked_pkt_id);
+       tmp_acked_pkt_id = htons(acked_pkt_id);
+       memcpy((buf + 2), &tmp_acked_pkt_id, 2);
 
        return 4;
 }