multicast: Document coap_mcast_set_hops()

include/coap3/coap_net.h

@@ -578,7 +578,8 @@ COAP_API int coap_join_mcast_group_intf(coap_context_t *ctx, const char *groupna
 
 /**
  * Function interface for defining the hop count (ttl) for sending
- * multicast traffic
+ * multicast traffic. The default is 1 so that the ttl expires after
+ * decrementing if the packet is trying to pass out of the local network.
  *
  * @param session The current session.
  * @param hops The number of hops (ttl) to use before the multicast

man/coap_endpoint_client.txt.in

@@ -15,7 +15,8 @@ coap_new_client_session,
 coap_new_client_session_psk2,
 coap_new_client_session_pki,
 coap_session_set_mtu,
-coap_session_max_pdu_size
+coap_session_max_pdu_size,
+coap_mcast_set_hops
 - Work with CoAP client endpoints
 
 SYNOPSIS
@@ -38,6 +39,8 @@ _proto_, coap_dtls_pki_t *_setup_data_);*
 
 *size_t coap_session_max_pdu_size(const coap_session_t *_session_);*
 
+*int coap_mcast_set_hops(coap_session_t *_session_, size_t _hops_);*
+
 For specific (D)TLS library support, link with
 *-lcoap-@LIBCOAP_API_VERSION@-notls*, *-lcoap-@LIBCOAP_API_VERSION@-gnutls*,
 *-lcoap-@LIBCOAP_API_VERSION@-openssl*, *-lcoap-@LIBCOAP_API_VERSION@-mbedtls*,
@@ -203,6 +206,14 @@ MTU is 1152.
 The *coap_session_max_pdu_size*() function is used to get the maximum MTU
 size of the data for the client endpoint's _session_.
 
+*Function: coap_mcast_set_hops()*
+
+The *coap_mcast_set_hops*() function is used to set the maximum number
+of _hops_ (ttl) that a transmitted multicast packet can pass through before
+getting dropped (default is 1, so that the ttl expires after decrementing
+if the packet is trying to pass out of the local network) for the specified
+_session_.
+
 RETURN VALUES
 -------------
 *coap_new_client_session*(), *coap_new_client_session_psk2*(),
@@ -211,6 +222,8 @@ session or NULL if there is a creation failure.
 
 *coap_session_max_pdu_size*() returns the MTU size.
 
+*coap_mcast_set_hops*() returns 1 on success, else 0 on failure.
+
 EXAMPLES
 --------
 *CoAP Client Non-Encrypted Setup*