基于libuv库的UDP收/发广播消息代码实现

 1 #include "uv.h"
 2 #include "task.h"
 3 
 4 #include <stdio.h>
 5 #include <stdlib.h>
 6 #include <string.h>
 7 
 8 static uv_udp_t client;
 9 
10 static uv_loop_t *loop;
11 
12 static void alloc_cb(uv_handle_t* handle,
13     size_t suggested_size,
14     uv_buf_t* buf) 
15 {
16     static char slab[65536];
17     buf->base = slab;
18     buf->len = sizeof(slab);
19 }
20 
21 static void close_cb(uv_handle_t* handle) 
22 {
23     uv_is_closing(handle);
24 }
25 
26 static void cl_recv_cb(uv_udp_t* handle,
27     ssize_t nread,
28     const uv_buf_t* buf,
29     const struct sockaddr* addr,
30     unsigned flags) 
31 {
32     if (nread < 0) 
33     {
34 
35     }
36 
37     if (nread == 0) 
38     {
39         return;
40     }
41 
42     printf("I receive the message from server:%s\n", buf->base);
43     
44     uv_close((uv_handle_t*) handle, close_cb);
45 }
46 
47 
48 static void cl_send_cb(uv_udp_send_t* req, int status) 
49 {   
50     uv_udp_recv_start(req->handle, alloc_cb, cl_recv_cb);
51 }
52 
53 int main(void) 
54 {
55     struct sockaddr_in addr;    
56     uv_udp_send_t req;
57     uv_buf_t buf;
58     int r;
59     
60     loop = uv_default_loop();
61        
62     r = uv_ip4_addr("0.0.0.0", 0, &addr);  
63     r = uv_udp_init(loop, &client);   
64     r = uv_udp_bind(&client, (const struct sockaddr*) &addr, 0);  
65     r = uv_udp_set_broadcast(&client, 1);
66     uv_ip4_addr("255.255.255.255", 8899, &addr); 
67     buf = uv_buf_init("PING", 4);
68     printf("I am sending message to server:%s.\n", buf.base);         
69     uv_udp_send(&req,
70         &client,
71         &buf,
72         1,
73         (const struct sockaddr*) &addr,
74         cl_send_cb);    
75 
76     uv_run(loop, UV_RUN_DEFAULT);
77 
78     return 0;
79 }

 1 #include "uv.h"
 2 #include "task.h"
 3 
 4 #include <stdio.h>
 5 #include <stdlib.h>
 6 #include <string.h>
 7 
 8 static uv_loop_t *loop;
 9 static uv_udp_t server;
10 
11 static void alloc_cb(uv_handle_t* handle,
12     size_t suggested_size,
13     uv_buf_t* buf) 
14 {
15     static char slab[65536];
16 
17     buf->base = slab;
18     buf->len = sizeof(slab);
19 }
20 
21 static void close_cb(uv_handle_t* handle) 
22 {
23     uv_is_closing(handle);
24 }
25 
26 static void sv_send_cb(uv_udp_send_t* req, int status) 
27 {
28     uv_close((uv_handle_t*) req->handle, close_cb);
29     free(req);
30 }
31 
32 static void sv_recv_cb(uv_udp_t* handle,
33     ssize_t nread,
34     const uv_buf_t* rcvbuf,
35     const struct sockaddr* addr,
36     unsigned flags) 
37 {
38     uv_udp_send_t* req;
39     uv_buf_t sndbuf;
40 
41     if (nread < 0) 
42     {
43 
44     }
45 
46     if (nread == 0) 
47     {
48         return;
49     }
50 
51     printf("I receive the message from client:%s.\n", rcvbuf->base);
52 
53     uv_udp_recv_stop(handle);
54 
55     req = malloc(sizeof *req);
56 
57     sndbuf = uv_buf_init("PONG", 4);
58     uv_udp_send(req, handle, &sndbuf, 1, addr, sv_send_cb);
59 }
60 
61 int main(void) 
62 {
63     struct sockaddr_in addr;
64     uv_udp_send_t req;
65     uv_buf_t buf;
66     int r;
67     
68     loop = uv_default_loop();
69     r = uv_ip4_addr("0.0.0.0", 8899, &addr);
70     r = uv_udp_init(loop, &server);    
71     r = uv_udp_bind(&server, (const struct sockaddr*) &addr, 0);    
72     r = uv_udp_recv_start(&server, alloc_cb, sv_recv_cb);
73 
74     uv_run(loop, UV_RUN_DEFAULT);
75 
76     return 0;
77 }