Simple Udp Send/Receive

[nolle]

Hi,

I am quite new to the MQX and I am having trouble narrowing down which functions to use to simply send and receive a udp packet. I'm pretty sure I have to use socket(), bind(), sendto() and recvfrom() but I don't know what I need to pass to these functions. I am using MQX 3.8 and M52259. Any help would be extremely appreciated.

Thank you

[drummer · Accepted solution]

/* This installs the socket and sets up for udp datagram */

    _io_socket_install("socket:");

udp_addr.sin_family      = AF_INET;

udp_addr.sin_port        = 5050;

udp_addr.sin_addr.s_addr = INADDR_ANY;

sock2 = socket(PF_INET, SOCK_DGRAM, 0);

return_error_if(sock2 == RTCS_SOCKET_ERROR);

error = bind(sock2, &udp_addr, sizeof(udp_addr));

return_error_if(error != RTCS_OK);

/* this waits for a UDP datagram */

  while (1) 

    {

  udp_sock = RTCS_selectall(0);

return_error_if(udp_sock == RTCS_SOCKET_ERROR);

if(udp_sock == sock2)

{

/* Datagram socket received data. */

memset(&udp_addr, 0, sizeof(udp_addr));// clean out ip info

memset(&udp_union.udp_buffer, 0, UDP_BUF_LEN); //clean out buffer

rlen = sizeof(udp_addr);

peer_adr_len = recvfrom(sock2, udp_union.udp_buffer, UDP_BUF_LEN, 0, &udp_addr, &rlen);

/* I like to use union because I'm old school */

    union

    {

in_struct in_msg;

    out_struct out_msg;

    uchar udp_buffer[UDP_BUF_LEN];

    }udp_union;

if (peer_adr_len == RTCS_ERROR) 

{

continue;

}

else

{

memcpy(&remote, &udp_addr, sizeof(remote)); // capture a copy of ip info

remote.sin_addr.s_addr = INADDR_BROADCAST;

if( strcmp(udp_union.in_msg.company_text,search_name))

continue;

/* the UDP is broadcast to all so I have to make sure its for me */

/* sending formatted data */

error = sendto(sock2,&udp_union.out_msg,512,0,&remote, sizeof(remote));

EASY PEESY PUDDIN PIE

 

[nolle]

First, thanks for the quick reply I do have a couple questions. What libraries would I have to include with this code because I am getting a substantial number of errors when I compile it.

Ex.

UDP_addr.sin_family      = AF_INET; 

>not a struct/union/class

and

= return_error_if(sock2 == RTCS_SOCKET_ERROR); 

>function has no prototype

Also I was wondering if you had missed some closing brackets.

Thank you

[drummer]

There is a nice demo example in the rtcs folder under examples called ipc_udp.

 sockaddr_in    udp_addr, remote;

defined in rtcs.h

/*
** Socket Address Structure
*/
typedef struct sockaddr_in {
uint_16 sin_family;
uint_16 sin_port;
in_addr sin_addr;
} sockaddr_in;

This is a define.

I don't know where I got it.

I seldom write my own code.

I like to cut and paste.

#define return_error_if(c) { if (c) _mqx_exit(0); }