applications: serial_lte_modem: SLM server fixes.

- Recv even when the connection is being closed.
- Fix statuses of operations to correspond to correct errno values.
- Documentation fixes.

Signed-off-by: Markus Lassila <markus.lassila@nordicsemi.no>

applications/serial_lte_modem/doc/TCPUDP_AT_commands.rst

@@ -42,6 +42,7 @@ Syntax
 * The ``<sec_tag>`` parameter is an integer.
  If it is given, a TLS server will be started.
  It indicates to the modem the credential of the security tag used for establishing a secure connection.
+ Can only be used when the :file:`overlay-native_tls.conf` configuration file is used.
 
 Response syntax
 ~~~~~~~~~~~~~~~
@@ -57,13 +58,40 @@ Response syntax
 * The ``<error>`` value is an integer.
  It represents the error value according to the standard POSIX *errno*.
 
-Examples
+Unsolicited notification
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+ #XTCPSVR: "<peer ip>","connected"
+
+This is emitted when a new connection has been created to the server.
+
+* The ``<peer_ip>`` value is the IPv4 or IPv6 address of the peer.
+
+.. tcpsvr_disconnect_notif_start
+
+::
+
+ #XTCPSVR: <error>,"disconnected"
+
+This is emitted when the client has been disconnected.
+
+* The ``<error>`` value is an integer.
+ It is either ``0`` when the client is disconnected normally, or an *-errno* code.
+
+.. tcpsvr_disconnect_notif_end
+
+
+Example
 ~~~~~~~~
 
 ::
 
  AT#XTCPSVR=1,3442,600
  #XTCPSVR: 2,"started"
+ #XTCPSVR: "123.456.789.123","connected"
+ #XTCPSVR: 0,"disconnected"
  OK
 
 Read command
@@ -319,11 +347,9 @@ Syntax
 Response syntax
 ~~~~~~~~~~~~~~~
 
-::
-
- #XTCPSVR: <cause>,"disconnected"
-
-* The ``<cause>`` value is an integer of -111 or ECONNREFUSED.
+.. include:: TCPUDP_AT_commands.rst
+ :start-after: tcpsvr_disconnect_notif_start
+ :end-before: tcpsvr_disconnect_notif_end
 
 Examples
 ~~~~~~~~
@@ -334,7 +360,7 @@ Examples
  #XTCPSVR: 1,2,1
  OK
  AT#XTCPHANGUP=2
- #XTCPSVR: -111,"disconnected"
+ #XTCPSVR: 0,"disconnected"
  OK
 
 Read command
@@ -376,11 +402,12 @@ TCP receive data
 
 ::
 
- <data>
  #XTCPDATA: <size>
+ <data>
 
+* The ``<size>`` parameter is an integer that indicates the size of the received data.
+ This notification comes only when SLM is not operating in :ref:`data mode <slm_data_mode>`.
 * The ``<data>`` parameter is a string that contains the data received.
-* The ``<size>`` parameter is the size of the string, which is present only when SLM is not operating in ``slm_data_mode``.
 
 UDP server #XUDPSVR
 ===================
@@ -655,8 +682,9 @@ UDP receive data
 
 ::
 
- <data>
  #XUDPDATA: <size>
+ <data>
 
+* The ``<size>`` parameter is an integer that indicates the size of the received data.
+ This notification comes only when SLM is not operating in :ref:`data mode <slm_data_mode>`.
 * The ``<data>`` parameter is a string that contains the data received.
-* The ``<size>`` parameter is the size of the string, which is present only when SLM is not operating in ``slm_data_mode``.

applications/serial_lte_modem/doc/slm_testing.rst

@@ -225,7 +225,7 @@ TCP client
  #XTCPCLI: 1,0
  OK
 
- #. Send plain text data to the TCP server and retrieve ten bytes of the returned data.
+ #. Send plain text data to the TCP server and receive ten bytes of the returned data.
 
  .. parsed-literal::
  :class: highlight
@@ -234,9 +234,8 @@ TCP client
  #XTCPSEND: 8
  OK
 
- **AT#XTCPRECV=10**
+ #XTCPDATA: 10
  PONG: b'Te
- #XTCPRECV: 10
  OK
 
  #. Disconnect and confirm the status of the connection.
@@ -450,20 +449,17 @@ You must register the corresponding credentials on the server side.
  #XTCPCLI: 1,0
  OK
 
- #. Send plain text data to the TLS server and retrieve the returned data.
+ #. Send plain text data to the TLS server and receive the returned data.
 
  .. parsed-literal::
  :class: highlight
 
  **AT#XTCPSEND="Test TLS client"**
  #XTCPSEND: 15
  OK
- #XTCPDATA: 24
 
- **AT#XTCPRECV**
+ #XTCPDATA: 24
  PONG: b'Test TLS client'
- #XTCPRECV: 24
- OK
 
  #. Disconnect from the server.
 
@@ -624,7 +620,7 @@ To act as a TCP server, |global_private_address|
  :class: highlight
 
  **AT#XSOCKET=1,1,1**
- #XSOCKET: 2,1,6
+ #XSOCKET: 0,1,6
  OK
 
  **AT#XBIND=**\ *1234*
@@ -640,16 +636,16 @@ To act as a TCP server, |global_private_address|
  .. parsed-literal::
  :class: highlight
 
- **AT#XACCEPT**
- #XACCEPT: connected with *IP address*
- #XACCEPT: 3
- OK
+ **AT#XACCEPT=60**
 
+ #XACCEPT: 1,"*IP address*"
+
+ OK
  **AT#XRECV=0**
+
  #XRECV: 26
  Hello, TCP#1!Hello, TCP#2!
  OK
-
  **AT#XSEND="TCP1/2 received"**
  #XSEND: 15
  OK
@@ -682,7 +678,7 @@ To act as a TCP server, |global_private_address|
  :class: highlight
 
  **AT#XSOCKET=0**
- #XSOCKET: "closed"
+ #XSOCKET: 0,"closed"
  OK
 
 
@@ -698,7 +694,7 @@ To act as a TCP server, |global_private_address|
  OK
 
  **AT#XTCPSVR?**
- #XTCPSVR: -1,-1
+ #XTCPSVR: -1,-1,0
  OK
 
  #. Create a TCP server and read the information about the current state.
@@ -708,59 +704,59 @@ To act as a TCP server, |global_private_address|
  :class: highlight
 
  **AT#XTCPSVR=1,**\ *1234*
- #XTCPSVR: 2,"started"
+ #XTCPSVR: 0,"started"
  OK
 
  **AT#XTCPSVR?**
- #XTCPSVR: 1,-1,0
+ #XTCPSVR: 0,-1,1
  OK
 
  #. Run the :file:`client_tcp.py` script to start sending data to the server.
 
- #. Observe that the server accepts the connection from the client.
+ #. Observe that the server accepts the connection from the client and receives the first packets.
  Read the information about the current state again.
 
  .. parsed-literal::
  :class: highlight
 
- #XTCPSVR: *IP address* connected
+ #XTCPSVR: "*IP address*","connected"
+
  #XTCPDATA: 13
+ Hello, TCP#1!
  #XTCPDATA: 13
+ Hello, TCP#2!
 
  **AT#XTCPSVR?**
- #XTCPSVR: 1,2,0
+ #XTCPSVR: 0,1,1
  OK
 
- #. Start receiving and acknowledging the data.
+ #. Send responses and receive the rest of the data.
+ Client disconnects after receiving the last response.
 
  .. parsed-literal::
  :class: highlight
 
- **AT#XTCPRECV**
- Hello, TCP#1!Hello, TCP#2!
- #XTCPRECV: 26
- OK
-
  **AT#XTCPSEND="TCP1/2 received"**
+
  #XTCPSEND: 15
+
  OK
+
  #XTCPDATA: 13
+ Hello, TCP#3!
  #XTCPDATA: 13
+ Hello, TCP#4!
  #XTCPDATA: 13
+ Hello, TCP#5!
 
- **AT#XTCPSVR?**
- #XTCPSVR: 1,2,0
- OK
-
- **AT#XTCPRECV**
- Hello, TCP#3!Hello, TCP#4!Hello, TCP#5!
- #XTCPRECV: 39
- OK
+ **AT#XTCPSEND="TCP3/4/5 received"**
 
- **AT#XTCPSEND=1,"TCP3/4/5 received"**
  #XTCPSEND: 17
+
  OK
 
+ #XTCPSVR: 0,"disconnected"
+
  #. Observe the output of the Python script::
 
  $ python client_tcp.py
@@ -780,7 +776,7 @@ To act as a TCP server, |global_private_address|
  :class: highlight
 
  **AT#XTCPSVR?**
- #XTCPSVR: 1,2,0
+ #XTCPSVR: 0,-1,1
  OK
 
  #. Stop the server.
@@ -789,11 +785,11 @@ To act as a TCP server, |global_private_address|
  :class: highlight
 
  **AT#XTCPSVR=0**
- #XTCPSVR:-1,"stopped"
+ #XTCPSVR:0,"stopped"
  OK
 
  **AT#XTCPSVR?**
- #XTCPSVR: -1,-1
+ #XTCPSVR: -1,-1,0
  OK
 
 UDP server
@@ -1003,31 +999,14 @@ To act as a UDP server, |global_private_address|
 TLS server
 ==========
 
-The TLS server role is currently not supported.
+The TLS server role is currently only supported when using the :file:`overlay-native_tls.conf` configuration file.
 
-.. parsed-literal::
- :class: highlight
-
- **AT#XSOCKET=1,1,1,16842753**
- #XSOCKET: "(D)TLS Server not supported"
- ERROR
-
- **AT#XTCPSVR=1,3443,16842753**
- #XTCPSVR: "TLS Server not supported"
- ERROR
 
 DTLS server
 ===========
 
 The DTLS server role is currently not supported (modem limitation).
 
-.. parsed-literal::
- :class: highlight
-
- **AT#XSOCKET=1,2,1,16842755**
- #XSOCKET: "(D)TLS Server not supported"
- ERROR
-
 DNS lookup
 ==========
 

applications/serial_lte_modem/src/slm_at_host.c

@@ -221,16 +221,15 @@ K_TIMER_DEFINE(inactivity_timer, inactivity_timer_handler, NULL);
 static size_t raw_rx_handler(const uint8_t *buf, const size_t len)
 {
  size_t processed;
- bool quit_str_match;
- bool prev_quit_str_match;
+ bool quit_str_match = false;
+ bool prev_quit_str_match = false;
  uint8_t quit_str_match_count;
  uint8_t prev_quit_str_match_count;
 
  k_mutex_lock(&mutex_data, K_FOREVER);
 
  /* Initialize from previous time.*/
  prev_quit_str_match_count = quit_str_partial_match;
- quit_str_match = false;
  quit_str_match_count = prev_quit_str_match_count;
  if (prev_quit_str_match_count != 0) {
  prev_quit_str_match = true;