Net events

Github Repo	C Header	C source	JS source
cesanta/mongoose-os	mgos_net.h	mgos_net.c	api_net.js

Low-level network configuration API.

Contains definitions of the configuration state. Allows to set up an event handler that tracks state changes: when the network connectivity is lost, established, etc.

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MGOS_EVENT_BASE

#define MGOS_EVENT_GRP_NET MGOS_EVENT_BASE('N', 'E', 'T')

Event group which should be given to mgos_event_add_group_handler() in order to subscribe to network events.

Example:

static void my_net_ev_handler(int ev, void *evd, void *arg) {
  if (ev == MGOS_NET_EV_IP_ACQUIRED) {
    LOG(LL_INFO, ("Just got IP!"));
    // Fetch something very useful from somewhere
  }
  (void) evd;
  (void) arg;
}

// Somewhere else:
mgos_event_add_group_handler(MGOS_EVENT_GRP_NET, my_net_ev_handler, NULL);

mgos_net_get_ip_info

bool mgos_net_get_ip_info(enum mgos_net_if_type if_type, int if_instance,
                          struct mgos_net_ip_info *ip_info);

Retrieve IP configuration of the provided interface type and instance number, and fill provided ip_info with it. Returns true in case of success, false otherwise.

mgos_net_ip_to_str

char *mgos_net_ip_to_str(const struct sockaddr_in *sin, char *out);

Converts address to dotted-quad NUL-terminated string. out must be at least 16 bytes long. Returns the out pointer.

mgos_net_str_to_ip

bool mgos_net_str_to_ip(const char *ips, struct sockaddr_in *sin);

Parses dotted-quad NUL-terminated string into an IPv4 address.

mgos_net_str_to_ip_n

bool mgos_net_str_to_ip_n(const struct mg_str ips, struct sockaddr_in *sin);

Parses dotted-quad NUL-terminated string into an IPv4 address.

mgos_get_nameserver

char *mgos_get_nameserver(void);

Returns nameserver address. The caller should free() it. Returns NULL in case of no DNS.

JS API

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Net.ctos

Net.ctos(conn, local, ip, port)

Convert address of a connection conn to string. Set local to true to stringify local address, otherwise false to stringify remote. Set ip to true to stringify IP, port to stringify port. Example:

print('Connection from:', Net.ctos(conn, false, true, true));

Net.discard

Net.discard(conn, len)

Remove initial len bytes of data from the connection's conn receive buffer in order to discard that data and reclaim RAM to the system.

Net.serve

Net.serve(options)

Start TCP or UDP server. options is an object:

{
   // Required. Port to listen on, 'tcp://PORT' or `udp://PORT`.
   addr: 'tcp://1234',
   // Optional. Called when connection is established.
   onconnect: function(conn) {}, 
   // Optional. Called when new data is arrived.
   ondata: function(conn, data) {},
   // Optional. Called when protocol-specific event is triggered.
   onevent: function(conn, data, ev, edata) {},
   // Optional. Called when the connection is about to close.
   onclose: function(conn) {},
   // Optional. Called when on connection error.
   onerror: function(conn) {},
}

Example - a UDP echo server. Change udp:// to tcp:// to turn this example into the TCP echo server:

Net.serve({
  addr: 'udp://1234',
  ondata: function(conn, data) {
    print('Received from:', Net.ctos(conn, false, true, true), ':', data);
    Net.send(conn, data);            // Echo received data back
    Net.discard(conn, data.length);  // Discard received data
  },
});

Net.connect

Net.connect(options)

Connect to a remote host. options is the same as for the Net.serve. The addr format is [PROTO://]HOST:PORT. PROTO could be tcp or udp. HOST could be an IP address or a host name. If HOST is a name, it will be resolved asynchronously.

Examples of valid addresses: google.com:80, udp://1.2.3.4:53, 10.0.0.1:443, [::1]:80.

Net.close

Net.close(conn)

Send all pending data to the remote peer, and disconnect when all data is sent. Return value: none.

Net.send

Net.send(conn, data)

Send data to the remote peer. data is an mJS string. Return value: none.

Net.EVENT_GRP

Net.EVENT_GRP

Net events group, to be used with Event.addGroupHandler(). Possible events are:

• Net.STATUS_DISCONNECTED
• Net.STATUS_CONNECTING
• Net.STATUS_CONNECTED
• Net.STATUS_GOT_IP

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