基于libuv库的UDP收/发广播消息代码实现

uv_send(发送端):

 #include "uv.h"
 #include "task.h"

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 static uv_udp_t client;

 static uv_loop_t *loop;

 static void alloc_cb(uv_handle_t* handle,
     size_t suggested_size,
     uv_buf_t* buf)
 {
     static char slab[];
     buf->base = slab;
     buf->len = sizeof(slab);
 }

 static void close_cb(uv_handle_t* handle)
 {
     uv_is_closing(handle);
 }

 static void cl_recv_cb(uv_udp_t* handle,
     ssize_t nread,
     const uv_buf_t* buf,
     const struct sockaddr* addr,
     unsigned flags)
 {
     if (nread < )
     {

     }

     if (nread == )
     {
         return;
     }

     printf("I receive the message from server:%s\n", buf->base);

     uv_close((uv_handle_t*) handle, close_cb);
 }

 static void cl_send_cb(uv_udp_send_t* req, int status)
 {
     uv_udp_recv_start(req->handle, alloc_cb, cl_recv_cb);
 }

 int main(void)
 {
     struct sockaddr_in addr;
     uv_udp_send_t req;
     uv_buf_t buf;
     int r;

     loop = uv_default_loop();

     r = uv_ip4_addr("0.0.0.0", , &addr);
     r = uv_udp_init(loop, &client);
     r = uv_udp_bind(&client, (const struct sockaddr*) &addr, );
     r = uv_udp_set_broadcast(&client, );
     uv_ip4_addr("255.255.255.255", , &addr);
     buf = uv_buf_init("PING", );
     printf("I am sending message to server:%s.\n", buf.base);
     uv_udp_send(&req,
         &client,
         &buf,
         ,
         (const struct sockaddr*) &addr,
         cl_send_cb);    

     uv_run(loop, UV_RUN_DEFAULT);

     return ;
 }

uv_recv(接收端):

 #include "uv.h"
 #include "task.h"

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 static uv_loop_t *loop;
 static uv_udp_t server;

 static void alloc_cb(uv_handle_t* handle,
     size_t suggested_size,
     uv_buf_t* buf)
 {
     static char slab[];

     buf->base = slab;
     buf->len = sizeof(slab);
 }

 static void close_cb(uv_handle_t* handle)
 {
     uv_is_closing(handle);
 }

 static void sv_send_cb(uv_udp_send_t* req, int status)
 {
     uv_close((uv_handle_t*) req->handle, close_cb);
     free(req);
 }

 static void sv_recv_cb(uv_udp_t* handle,
     ssize_t nread,
     const uv_buf_t* rcvbuf,
     const struct sockaddr* addr,
     unsigned flags)
 {
     uv_udp_send_t* req;
     uv_buf_t sndbuf;

     if (nread < )
     {

     }

     if (nread == )
     {
         return;
     }

     printf("I receive the message from client:%s.\n", rcvbuf->base);

     uv_udp_recv_stop(handle);

     req = malloc(sizeof *req);

     sndbuf = uv_buf_init("PONG", );
     uv_udp_send(req, handle, &sndbuf, , addr, sv_send_cb);
 }

 int main(void)
 {
     struct sockaddr_in addr;
     uv_udp_send_t req;
     uv_buf_t buf;
     int r;

     loop = uv_default_loop();
     r = uv_ip4_addr("0.0.0.0", , &addr);
     r = uv_udp_init(loop, &server);
     r = uv_udp_bind(&server, (const struct sockaddr*) &addr, );
     r = uv_udp_recv_start(&server, alloc_cb, sv_recv_cb);

     uv_run(loop, UV_RUN_DEFAULT);

     return ;
 }