Fix message_size_limit not applying to the Will payload.

Closes #2022. Thanks to Umberto Morelli.

ChangeLog.txt

@@ -9,6 +9,7 @@ Broker:
 - Improve logging in obscure cases when a client disconnects. Closes #2017.
 - Fix reloading of listeners where multiple listeners have been defined with
  the same port but different bind addresses. Closes #2029.
+- Fix `message_size_limit` not applying to the Will payload. Closes #2022.
 
 Apps:
 - Allow command line arguments to override config file options in

src/conf.c

@@ -1696,6 +1696,7 @@ int config__read_file_core(struct mosquitto__config *config, bool reload, struct
  }
  memory__set_limit((size_t)lim);
  }else if(!strcmp(token, "message_size_limit")){
+ log__printf(NULL, MOSQ_LOG_NOTICE, "Note: It is recommended to replace `message_size_limit` with `max_packet_size`.");
  if(conf__parse_int(&token, "message_size_limit", (int *)&config->message_size_limit, saveptr)) return MOSQ_ERR_INVAL;
  if(config->message_size_limit > MQTT_MAX_PAYLOAD){
  log__printf(NULL, MOSQ_LOG_ERR, "Error: Invalid message_size_limit value (%u).", config->message_size_limit);

src/handle_connect.c

@@ -291,7 +291,7 @@ int connect__on_authorised(struct mosquitto *context, void *auth_data_out, uint1
 }
 
 
-static int will__read(struct mosquitto *context, struct mosquitto_message_all **will, uint8_t will_qos, int will_retain)
+static int will__read(struct mosquitto *context, const char *client_id, struct mosquitto_message_all **will, uint8_t will_qos, int will_retain)
 {
  int rc = MOSQ_ERR_SUCCESS;
  size_t slen;
@@ -344,6 +344,17 @@ static int will__read(struct mosquitto *context, struct mosquitto_message_all **
 
  will_struct->msg.payloadlen = payloadlen;
  if(will_struct->msg.payloadlen > 0){
+ if(db.config->message_size_limit && will_struct->msg.payloadlen > db.config->message_size_limit){
+ log__printf(NULL, MOSQ_LOG_DEBUG, "Client %s connected with too large Will payload", client_id);
+ if(context->protocol == mosq_p_mqtt5){
+ send__connack(context, 0, MQTT_RC_PACKET_TOO_LARGE, NULL);
+ }else{
+ send__connack(context, 0, CONNACK_REFUSED_NOT_AUTHORIZED, NULL);
+ }
+ context__disconnect(context);
+ rc = MOSQ_ERR_PAYLOAD_SIZE;
+ goto error_cleanup;
+ }
  will_struct->msg.payload = mosquitto__malloc((size_t)will_struct->msg.payloadlen);
  if(!will_struct->msg.payload){
  rc = MOSQ_ERR_NOMEM;
@@ -602,7 +613,7 @@ int handle__connect(struct mosquitto *context)
  }
 
  if(will){
- rc = will__read(context, &will_struct, will_qos, will_retain);
+ rc = will__read(context, client_id, &will_struct, will_qos, will_retain);
  if(rc) goto handle_connect_error;
  }else{
  if(context->protocol == mosq_p_mqtt311 || context->protocol == mosq_p_mqtt5){

src/handle_publish.c

@@ -224,7 +224,7 @@ int handle__publish(struct mosquitto *context)
  if(msg->payloadlen){
  if(db.config->message_size_limit && msg->payloadlen > db.config->message_size_limit){
  log__printf(NULL, MOSQ_LOG_DEBUG, "Dropped too large PUBLISH from %s (d%d, q%d, r%d, m%d, '%s', ... (%ld bytes))", context->id, dup, msg->qos, msg->retain, msg->source_mid, msg->topic, (long)msg->payloadlen);
- reason_code = MQTT_RC_IMPLEMENTATION_SPECIFIC;
+ reason_code = MQTT_RC_PACKET_TOO_LARGE;
  goto process_bad_message;
  }
  msg->payload = mosquitto__malloc(msg->payloadlen+1);

src/loop.c

@@ -344,6 +344,9 @@ void do_disconnect(struct mosquitto *context, int reason)
  case MOSQ_ERR_OVERSIZE_PACKET:
  log__printf(NULL, MOSQ_LOG_NOTICE, "Client %s disconnected due to oversize packet.", id);
  break;
+ case MOSQ_ERR_PAYLOAD_SIZE:
+ log__printf(NULL, MOSQ_LOG_NOTICE, "Client %s disconnected due to oversize payload.", id);
+ break;
  case MOSQ_ERR_NOMEM:
  log__printf(NULL, MOSQ_LOG_NOTICE, "Client %s disconnected due to out of memory.", id);
  break;
@@ -357,7 +360,7 @@ void do_disconnect(struct mosquitto *context, int reason)
  log__printf(NULL, MOSQ_LOG_NOTICE, "Client %s disconnected: %s.", id, strerror(errno));
  break;
  default:
- log__printf(NULL, MOSQ_LOG_NOTICE, "Bad socket read/write on client %s: %s.", id, mosquitto_strerror(reason));
+ log__printf(NULL, MOSQ_LOG_NOTICE, "Bad socket read/write on client %s: %s", id, mosquitto_strerror(reason));
  break;
  }
  }else{

test/broker/02-subpub-qos0-oversize-payload.py

@@ -0,0 +1,75 @@
+#!/usr/bin/env python3
+
+# Test whether message size limits apply.
+
+from mosq_test_helper import *
+
+def write_config(filename, port):
+ with open(filename, 'w') as f:
+ f.write("listener %d\n" % (port))
+ f.write("allow_anonymous true\n")
+ f.write("message_size_limit 1\n")
+
+def do_test(proto_ver):
+ rc = 1
+ mid = 53
+ keepalive = 60
+ connect_packet = mosq_test.gen_connect("subpub-qos0-test", keepalive=keepalive, proto_ver=proto_ver)
+ connack_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
+
+ subscribe_packet = mosq_test.gen_subscribe(mid, "subpub/qos0", 0, proto_ver=proto_ver)
+ suback_packet = mosq_test.gen_suback(mid, 0, proto_ver=proto_ver)
+
+ connect2_packet = mosq_test.gen_connect("subpub-qos0-helper", keepalive=keepalive, proto_ver=proto_ver)
+ connack2_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
+
+ publish_packet_ok = mosq_test.gen_publish("subpub/qos0", qos=0, payload="A", proto_ver=proto_ver)
+ publish_packet_bad = mosq_test.gen_publish("subpub/qos0", qos=0, payload="AB", proto_ver=proto_ver)
+
+ port = mosq_test.get_port()
+ conf_file = os.path.basename(__file__).replace('.py', '.conf')
+ write_config(conf_file, port)
+
+ broker = mosq_test.start_broker(filename=os.path.basename(__file__), use_conf=True, port=port)
+
+ try:
+ sock = mosq_test.do_client_connect(connect_packet, connack_packet, timeout=20, port=port)
+ mosq_test.do_send_receive(sock, subscribe_packet, suback_packet, "suback")
+
+ sock2 = mosq_test.do_client_connect(connect2_packet, connack2_packet, timeout=20, port=port)
+ sock2.send(publish_packet_ok)
+ mosq_test.expect_packet(sock, "publish 1", publish_packet_ok)
+
+ # Check all is still well on the publishing client
+ mosq_test.do_ping(sock2)
+
+ sock2.send(publish_packet_bad)
+
+ # Check all is still well on the publishing client
+ mosq_test.do_ping(sock2)
+
+ # The subscribing client shouldn't have received a PUBLISH
+ mosq_test.do_ping(sock)
+ rc = 0
+
+ sock.close()
+ except SyntaxError:
+ raise
+ except TypeError:
+ raise
+ except mosq_test.TestError:
+ pass
+ finally:
+ os.remove(conf_file)
+ broker.terminate()
+ broker.wait()
+ (stdo, stde) = broker.communicate()
+ if rc:
+ print(stde.decode('utf-8'))
+ print("proto_ver=%d" % (proto_ver))
+ exit(rc)
+
+
+do_test(proto_ver=4)
+do_test(proto_ver=5)
+exit(0)

test/broker/02-subpub-qos1-oversize-payload.py

@@ -0,0 +1,81 @@
+#!/usr/bin/env python3
+
+# Test whether message size limits apply.
+
+from mosq_test_helper import *
+
+def write_config(filename, port):
+ with open(filename, 'w') as f:
+ f.write("listener %d\n" % (port))
+ f.write("allow_anonymous true\n")
+ f.write("message_size_limit 1\n")
+
+def do_test(proto_ver):
+ rc = 1
+ mid = 53
+ keepalive = 60
+ connect_packet = mosq_test.gen_connect("subpub-qos1-test", keepalive=keepalive, proto_ver=proto_ver)
+ connack_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
+
+ subscribe_packet = mosq_test.gen_subscribe(mid, "subpub/qos1", 1, proto_ver=proto_ver)
+ suback_packet = mosq_test.gen_suback(mid, 1, proto_ver=proto_ver)
+
+ connect2_packet = mosq_test.gen_connect("subpub-qos1-helper", keepalive=keepalive, proto_ver=proto_ver)
+ connack2_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
+
+ mid = 1
+ publish_packet_ok = mosq_test.gen_publish("subpub/qos1", mid=mid, qos=1, payload="A", proto_ver=proto_ver)
+ puback_packet_ok = mosq_test.gen_puback(mid=mid, proto_ver=proto_ver)
+
+ mid = 2
+ publish_packet_bad = mosq_test.gen_publish("subpub/qos1", mid=mid, qos=1, payload="AB", proto_ver=proto_ver)
+ if proto_ver == 5:
+ puback_packet_bad = mosq_test.gen_puback(reason_code=mqtt5_rc.MQTT_RC_PACKET_TOO_LARGE, mid=mid, proto_ver=proto_ver)
+ else:
+ puback_packet_bad = mosq_test.gen_puback(mid=mid, proto_ver=proto_ver)
+
+ port = mosq_test.get_port()
+ conf_file = os.path.basename(__file__).replace('.py', '.conf')
+ write_config(conf_file, port)
+
+ broker = mosq_test.start_broker(filename=os.path.basename(__file__), use_conf=True, port=port)
+
+ try:
+ sock = mosq_test.do_client_connect(connect_packet, connack_packet, timeout=20, port=port)
+ mosq_test.do_send_receive(sock, subscribe_packet, suback_packet, "suback")
+
+ sock2 = mosq_test.do_client_connect(connect2_packet, connack2_packet, timeout=20, port=port)
+ mosq_test.do_send_receive(sock2, publish_packet_ok, puback_packet_ok, "puback 1")
+ mosq_test.expect_packet(sock, "publish 1", publish_packet_ok)
+ sock.send(puback_packet_ok)
+
+ # Check all is still well on the publishing client
+ mosq_test.do_ping(sock2)
+
+ mosq_test.do_send_receive(sock2, publish_packet_bad, puback_packet_bad, "puback 2")
+
+ # The subscribing client shouldn't have received a PUBLISH
+ mosq_test.do_ping(sock)
+ rc = 0
+
+ sock.close()
+ except SyntaxError:
+ raise
+ except TypeError:
+ raise
+ except mosq_test.TestError:
+ pass
+ finally:
+ os.remove(conf_file)
+ broker.terminate()
+ broker.wait()
+ (stdo, stde) = broker.communicate()
+ if rc:
+ print(stde.decode('utf-8'))
+ print("proto_ver=%d" % (proto_ver))
+ exit(rc)
+
+
+do_test(proto_ver=4)
+do_test(proto_ver=5)
+exit(0)

test/broker/07-will-oversize-payload.py

@@ -0,0 +1,71 @@
+#!/usr/bin/env python3
+
+# Test whether a client will that is too large is handled
+
+from mosq_test_helper import *
+
+def write_config(filename, port):
+ with open(filename, 'w') as f:
+ f.write("listener %d\n" % (port))
+ f.write("allow_anonymous true\n")
+ f.write("message_size_limit 1\n")
+
+def do_test(proto_ver, clean_session):
+ rc = 1
+ mid = 53
+ keepalive = 60
+ connect_packet = mosq_test.gen_connect("will-test", keepalive=keepalive, proto_ver=proto_ver)
+ connack_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
+
+ connect_packet_ok = mosq_test.gen_connect("test-helper", keepalive=keepalive, will_topic="will/qos0/test", will_payload=b"A", clean_session=clean_session, proto_ver=proto_ver, session_expiry=60)
+ connack_packet_ok = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
+
+ connect_packet_bad = mosq_test.gen_connect("test-helper", keepalive=keepalive, will_topic="will/qos0/test", will_payload=b"AB", clean_session=clean_session, proto_ver=proto_ver, session_expiry=60)
+ if proto_ver == 5:
+ connack_packet_bad = mosq_test.gen_connack(rc=mqtt5_rc.MQTT_RC_PACKET_TOO_LARGE, proto_ver=proto_ver, property_helper=False)
+ else:
+ connack_packet_bad = mosq_test.gen_connack(rc=5, proto_ver=proto_ver)
+
+ subscribe_packet = mosq_test.gen_subscribe(mid, "will/qos0/test", 0, proto_ver=proto_ver)
+ suback_packet = mosq_test.gen_suback(mid, 0, proto_ver=proto_ver)
+
+ publish_packet = mosq_test.gen_publish("will/qos0/test", qos=0, payload="A", proto_ver=proto_ver)
+
+ port = mosq_test.get_port()
+ conf_file = os.path.basename(__file__).replace('.py', '.conf')
+ write_config(conf_file, port)
+
+ broker = mosq_test.start_broker(filename=os.path.basename(__file__), use_conf=True, port=port)
+
+ try:
+ sock = mosq_test.do_client_connect(connect_packet, connack_packet, timeout=5, port=port)
+ mosq_test.do_send_receive(sock, subscribe_packet, suback_packet, "suback")
+
+ sock2 = mosq_test.do_client_connect(connect_packet_bad, connack_packet_bad, port=port, timeout=5)
+ sock2.close()
+
+ sock2 = mosq_test.do_client_connect(connect_packet_ok, connack_packet_ok, port=port, timeout=5)
+ sock2.close()
+
+ mosq_test.expect_packet(sock, "publish", publish_packet)
+ # Check there are no more messages
+ mosq_test.do_ping(sock)
+ rc = 0
+
+ sock.close()
+ except mosq_test.TestError:
+ pass
+ finally:
+ os.remove(conf_file)
+ broker.terminate()
+ broker.wait()
+ (stdo, stde) = broker.communicate()
+ if rc:
+ print(stde.decode('utf-8'))
+ exit(rc)
+
+do_test(4, True)
+do_test(4, False)
+do_test(5, True)
+do_test(5, False)
+exit(0)

test/broker/Makefile

@@ -44,6 +44,7 @@ test : test-compile 01 02 03 04 05 06 07 08 09 10 11 12 13 14
  ./02-shared-qos0-v5.py
  ./02-subhier-crash.py
  ./02-subpub-qos0-long-topic.py
+ ./02-subpub-qos0-oversize-payload.py
  ./02-subpub-qos0-retain-as-publish.py
  ./02-subpub-qos0-send-retain.py
  ./02-subpub-qos0-subscription-id.py
@@ -56,6 +57,7 @@ test : test-compile 01 02 03 04 05 06 07 08 09 10 11 12 13 14
  ./02-subpub-qos1-message-expiry-will.py
  ./02-subpub-qos1-message-expiry.py
  ./02-subpub-qos1-nolocal.py
+ ./02-subpub-qos1-oversize-payload.py
  ./02-subpub-qos1.py
  ./02-subpub-qos2-1322.py
  ./02-subpub-qos2-bad-puback-1.py
@@ -141,6 +143,7 @@ test : test-compile 01 02 03 04 05 06 07 08 09 10 11 12 13 14
  ./07-will-no-flag.py
  ./07-will-null-topic.py
  ./07-will-null.py
+ ./07-will-oversize-payload.py
  ./07-will-properties.py
  ./07-will-qos0.py
  ./07-will-reconnect-1273.py

test/broker/test.py

@@ -27,6 +27,7 @@
  (1, './02-shared-qos0-v5.py'),
  (1, './02-subhier-crash.py'),
  (1, './02-subpub-qos0-long-topic.py'),
+ (1, './02-subpub-qos0-oversize-payload.py'),
  (1, './02-subpub-qos0-retain-as-publish.py'),
  (1, './02-subpub-qos0-send-retain.py'),
  (1, './02-subpub-qos0-subscription-id.py'),
@@ -39,6 +40,7 @@
  (1, './02-subpub-qos1-message-expiry-will.py'),
  (1, './02-subpub-qos1-message-expiry.py'),
  (1, './02-subpub-qos1-nolocal.py'),
+ (1, './02-subpub-qos1-oversize-payload.py'),
  (1, './02-subpub-qos1.py'),
  (1, './02-subpub-qos2-1322.py'),
  (1, './02-subpub-qos2-bad-puback-1.py'),
@@ -120,6 +122,7 @@
  (1, './07-will-no-flag.py'),
  (1, './07-will-null-topic.py'),
  (1, './07-will-null.py'),
+ (1, './07-will-oversize-payload.py'),
  (1, './07-will-properties.py'),
  (1, './07-will-qos0.py'),
  (1, './07-will-reconnect-1273.py'),

test/mosq_test.py

@@ -284,12 +284,20 @@ def to_string(packet):
  return s
  elif cmd == 0x40:
  # PUBACK
- (cmd, rl, mid) = struct.unpack('!BBH', packet)
- return "PUBACK, rl="+str(rl)+", mid="+str(mid)
+ if len(packet) == 5:
+ (cmd, rl, mid, reason_code) = struct.unpack('!BBHB', packet)
+ return "PUBACK, rl="+str(rl)+", mid="+str(mid)+", reason_code="+str(reason_code)
+ else:
+ (cmd, rl, mid) = struct.unpack('!BBH', packet)
+ return "PUBACK, rl="+str(rl)+", mid="+str(mid)
  elif cmd == 0x50:
  # PUBREC
- (cmd, rl, mid) = struct.unpack('!BBH', packet)
- return "PUBREC, rl="+str(rl)+", mid="+str(mid)
+ if len(packet) == 5:
+ (cmd, rl, mid, reason_code) = struct.unpack('!BBHB', packet)
+ return "PUBREC, rl="+str(rl)+", mid="+str(mid)+", reason_code="+str(reason_code)
+ else:
+ (cmd, rl, mid) = struct.unpack('!BBH', packet)
+ return "PUBREC, rl="+str(rl)+", mid="+str(mid)
  elif cmd == 0x60:
  # PUBREL
  dup = (packet0 & 0x08)>>3
@@ -353,8 +361,12 @@ def to_string(packet):
  return "PINGRESP, rl="+str(rl)
  elif cmd == 0xE0:
  # DISCONNECT
- (cmd, rl) = struct.unpack('!BB', packet)
- return "DISCONNECT, rl="+str(rl)
+ if len(packet) == 3:
+ (cmd, rl, reason_code) = struct.unpack('!BBB', packet)
+ return "DISCONNECT, rl="+str(rl)+", reason_code="+str(reason_code)
+ else:
+ (cmd, rl) = struct.unpack('!BB', packet)
+ return "DISCONNECT, rl="+str(rl)
  elif cmd == 0xF0:
  # AUTH
  (cmd, rl) = struct.unpack('!BB', packet)