/**
* \addtogroup simple-udp
* @{
*/
/*
* Copyright (c) 2011, Swedish Institute of Computer Science.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
* \file
* Header file for the simple-udp module.
* \author
* Adam Dunkels <adam@sics.se>
*
*/
#include "contiki-net.h"
#include "net/simple-udp.h"
#include <string.h>
PROCESS(simple_udp_process, "Simple UDP process");
static uint8_t started = 0;
static uint8_t databuffer[UIP_BUFSIZE];
#define UIP_IP_BUF ((struct uip_udpip_hdr *)&uip_buf[UIP_LLH_LEN])
/*---------------------------------------------------------------------------*/
static void
init_simple_udp(void)
{
if(started == 0) {
process_start(&simple_udp_process, NULL);
started = 1;
}
}
/*---------------------------------------------------------------------------*/
/**
* \brief Send a UDP packet
* \param c A pointer to a struct simple_udp_connection
* \param data A pointer to the data to be sent
* \param datalen The length of the data
*
* This function sends a UDP packet. The packet will be
* sent to the IP address and with the UDP ports that were
* specified when the connection wa registered with
* simple_udp_register().
*
* \sa simple_udp_sendto()
*/
int
simple_udp_send(struct simple_udp_connection *c,
const void *data, uint16_t datalen)
{
if(c->udp_conn != NULL) {
uip_udp_packet_sendto(c->udp_conn, data, datalen,
&c->remote_addr, UIP_HTONS(c->remote_port));
}
return 0;
}
/*---------------------------------------------------------------------------*/
/**
* \brief Send a UDP packet to a specified IP address
* \param c A pointer to a struct simple_udp_connection
* \param data A pointer to the data to be sent
* \param datalen The length of the data
* \param to The IP address of the receiver
*
* This function sends a UDP packet to a specified IP
* address. The packet will be sent with the UDP ports
* that were specified when the connection wa registered
* with simple_udp_register().
*
* \sa simple_udp_send()
*/
int
simple_udp_sendto(struct simple_udp_connection *c,
const void *data, uint16_t datalen,
const uip_ipaddr_t *to)
{
if(c->udp_conn != NULL) {
uip_udp_packet_sendto(c->udp_conn, data, datalen,
to, UIP_HTONS(c->remote_port));
}
return 0;
}
/*---------------------------------------------------------------------------*/
/**
* \brief Register a UDP connection
* \param c A pointer to a struct simple_udp_connection
* \param local_port The local UDP port in host byte order
* \param remote_addr The remote IP address
* \param remote_port The remote UDP port in host byte order
* \param receive_callback A pointer to a function to be called for incoming packets
* \retval 0 If no UDP connection could be allocated
* \retval 1 If the connection was successfully allocated
*
* This function registers a UDP connection and attaches a
* callback function to it. The callback function will be
* called for incoming packets. The local UDP port can be
* set to 0 to indicate that an ephemeral UDP port should
* be allocated. The remote IP address can be NULL, to
* indicate that packets from any IP address should be
* accepted.
*
*/
int
simple_udp_register(struct simple_udp_connection *c,
uint16_t local_port,
uip_ipaddr_t *remote_addr,
uint16_t remote_port,
simple_udp_callback receive_callback)
{
init_simple_udp();
c->local_port = local_port;
c->remote_port = remote_port;
if(remote_addr != NULL) {
uip_ipaddr_copy(&c->remote_addr, remote_addr);
}
c->receive_callback = receive_callback;
PROCESS_CONTEXT_BEGIN(&simple_udp_process);
c->udp_conn = udp_new(remote_addr, UIP_HTONS(remote_port), c);
if(c->udp_conn != NULL) {
udp_bind(c->udp_conn, UIP_HTONS(local_port));
}
PROCESS_CONTEXT_END();
if(c->udp_conn == NULL) {
return 0;
}
return 1;
}
/*---------------------------------------------------------------------------*/
PROCESS_THREAD(simple_udp_process, ev, data)
{
struct simple_udp_connection *c;
PROCESS_BEGIN();
while(1) {
PROCESS_WAIT_EVENT();
if(ev == tcpip_event) {
/* An appstate pointer is passed to use from the IP stack
through the 'data' pointer. We registered this appstate when
we did the udp_new() call in simple_udp_register() as the
struct simple_udp_connection pointer. So we extract this
pointer and use it when calling the reception callback. */
c = (struct simple_udp_connection *)data;
/* Defensive coding: although the appstate *should* be non-null
here, we make sure to avoid the program crashing on us. */
if(c != NULL) {
/* If we were called because of incoming data, we should call
the reception callback. */
if(uip_newdata()) {
/* Copy the data from the uIP data buffer into our own
buffer to avoid the uIP buffer being messed with by the
callee. */
memcpy(databuffer, uip_appdata, uip_datalen());
/* Call the client process. We use the PROCESS_CONTEXT
mechanism to temporarily switch process context to the
client process. */
if(c->receive_callback != NULL) {
PROCESS_CONTEXT_BEGIN(c->client_process);
c->receive_callback(c,
&(UIP_IP_BUF->srcipaddr),
UIP_HTONS(UIP_IP_BUF->srcport),
&(UIP_IP_BUF->destipaddr),
UIP_HTONS(UIP_IP_BUF->destport),
databuffer, uip_datalen());
PROCESS_CONTEXT_END();
}
}
}
}
}
PROCESS_END();
}
/*---------------------------------------------------------------------------*/
/** @} */