client.c
#include
#include
#include
#include
#include
#include
#include
int main()
{
int sock = 0;
struct sockaddr_in addr = {0};
struct sockaddr_in remote = {0};
int len = 0;
char buf[128] = {0};
char input[32] = {0};
int r = 0;
sock = socket(PF_INET, SOCK_DGRAM, 0);
if( sock == -1 )
{
printf("socket error\n");
return -1;
}
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = htonl(INADDR_ANY);
addr.sin_port = htons(9999);
if( bind(sock, (struct sockaddr*)&addr, sizeof(addr)) == -1 )
{
printf("udp bind error\n");
return -1;
}
remote.sin_family = AF_INET;
remote.sin_addr.s_addr = inet_addr("127.0.0.1");
remote.sin_port = htons(8888);
while( 1 )
{
printf("Input: ");
scanf("%s", input);
len = sizeof(remote);
sendto(sock, input, strlen(input), 0, (struct sockaddr*)&remote, len);
r = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr*)&remote, &len);
if( r > 0 )
{
buf[r] = 0;
printf("Receive: %s\n", buf);
}
else
{
break;
}
}
close(sock);
return 0;
}
server.c
#include
#include
#include
#include
#include
#include
#include
int main()
{
int server = 0;
struct sockaddr_in saddr = {0};
int client = 0;
struct sockaddr_in remote = {0};
socklen_t asize = 0;
int len = 0;
char buf[32] = {0};
int r = 0;
server = socket(PF_INET, SOCK_DGRAM, 0);
if( server == -1 )
{
printf("server socket error\n");
return -1;
}
saddr.sin_family = AF_INET;
saddr.sin_addr.s_addr = htonl(INADDR_ANY);
saddr.sin_port = htons(8888);
if( bind(server, (struct sockaddr*)&saddr, sizeof(saddr)) == -1 )
{
printf("udp server bind error\n");
return -1;
}
printf("udp server start success\n");
while( 1 )
{
len = sizeof(remote);
r = recvfrom(server, buf, sizeof(buf), 0, (struct sockaddr*)&remote, &len);
buf[r] = 0;
printf("r = %d\n", r);
printf("buf = %s\n", buf);
printf("remote ip = %s\n", inet_ntoa(remote.sin_addr));
printf("remote port = %d\n", ntohs(remote.sin_port));
sendto(server, buf, r, 0, (struct sockaddr*)&remote, len);
}
close(server);
return 0;
}
⑦ 实验
client.c
#include
#include
#include
#include
#include
#include
#include
int main()
{
int sock = 0;
struct sockaddr_in addr = {0};
struct sockaddr_in remote = {0};
int len = 0;
char buf[128] = {0};
char input[32] = {0};
int r = 0;
sock = socket(PF_INET, SOCK_DGRAM, 0);
if( sock == -1 )
{
printf("socket error\n");
return -1;
}
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = htonl(INADDR_ANY);
addr.sin_port = htons(9000);
if( bind(sock, (struct sockaddr*)&addr, sizeof(addr)) == -1 )
{
printf("udp bind error\n");
return -1;
}
remote.sin_family = AF_INET;
remote.sin_addr.s_addr = inet_addr("127.0.0.1");
remote.sin_port = htons(8888);
while( 1 )
{
r = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr*)&remote, &len);
if( r > 0 )
{
buf[r] = 0;
printf("Receive: %s\n", buf);
}
else
{
break;
}
}
close(sock);
return 0;
}
server.c
#include
#include
#include
#include
#include
#include
#include
int main()
{
int server = 0;
struct sockaddr_in saddr = {0};
int client = 0;
struct sockaddr_in remote = {0};
socklen_t asize = 0;
int len = 0;
char buf[32] = "D.T.Software";
int r = 0;
int brd = 1;
server = socket(PF_INET, SOCK_DGRAM, 0);
if( server == -1 )
{
printf("server socket error\n");
return -1;
}
saddr.sin_family = AF_INET;
saddr.sin_addr.s_addr = htonl(INADDR_ANY);
saddr.sin_port = htons(8888);
if( bind(server, (struct sockaddr*)&saddr, sizeof(saddr)) == -1 )
{
printf("udp server bind error\n");
return -1;
}
printf("udp server start success\n");
remote.sin_family = AF_INET;
// remote.sin_addr.s_addr = inet_addr("192.168.3.255");
remote.sin_addr.s_addr = 0xFFFFFFFF;
remote.sin_port = htons(9000);
// brd = 0;
setsockopt(server, SOL_SOCKET, SO_BROADCAST, &brd, sizeof(brd));
while( 1 )
{
len = sizeof(remote);
r = strlen(buf);
sendto(server, buf, r, 0, (struct sockaddr*)&remote, len);
sleep(1);
}
close(server);
return 0;
}
IP_ADD_MEMBERSHIP
单网卡中可以使用INADDR_ANY(0.0.0.0),多网卡时,需要手动指定网卡。
mul_rx.c
#include
#include
#include
#include
#include
#include
#include
int main()
{
int sock = 0;
struct sockaddr_in addr = {0};
struct sockaddr_in remote = {0};
struct ip_mreq group = {0};
int len = 0;
char buf[128] = {0};
char input[32] = {0};
int r = 0;
sock = socket(PF_INET, SOCK_DGRAM, 0);
if( sock == -1 )
{
printf("socket error\n");
return -1;
}
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = htonl(INADDR_ANY); // local host
addr.sin_port = htons(9000);
if( bind(sock, (struct sockaddr*)&addr, sizeof(addr)) == -1 )
{
printf("udp bind error\n");
return -1;
}
group.imr_multiaddr.s_addr = inet_addr("224.1.1.168");
group.imr_interface.s_addr = htonl(INADDR_ANY); // local host
setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, &group, sizeof(group));
while( 1 )
{
len = sizeof(remote);
r = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr*)&remote, &len);
if( r > 0 )
{
buf[r] = 0;
printf("Receive: %s\n", buf);
}
else
{
break;
}
}
close(sock);
return 0;
}
仅限单网卡
mul_tx.c
#include
#include
#include
#include
#include
#include
#include
int main()
{
int server = 0;
struct sockaddr_in saddr = {0};
int client = 0;
struct sockaddr_in remote = {0};
socklen_t asize = 0;
int len = 0;
char buf[32] = "D.T.Software";
int r = 0;
int ttl = 0;
int loop = 0;
struct in_addr addr = {0};
server = socket(PF_INET, SOCK_DGRAM, 0);
if( server == -1 )
{
printf("server socket error\n");
return -1;
}
saddr.sin_family = AF_INET;
saddr.sin_addr.s_addr = htonl(INADDR_ANY); // local host
saddr.sin_port = htons(8888);
if( bind(server, (struct sockaddr*)&saddr, sizeof(saddr)) == -1 )
{
printf("udp server bind error\n");
return -1;
}
printf("udp server start success\n");
remote.sin_family = AF_INET;
remote.sin_addr.s_addr = inet_addr("224.1.1.168");
remote.sin_port = htons(9000);
ttl = 0;
len = sizeof(ttl);
getsockopt(server, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, &len);
printf("default ttl = %d\n", ttl);
ttl = 32;
len = sizeof(ttl);
setsockopt(server, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, len);
printf("current ttl = %d\n", ttl);
loop = 0;
len = sizeof(loop);
getsockopt(server, IPPROTO_IP, IP_MULTICAST_LOOP, &loop, &len);
printf("default loop = %d\n", loop);
addr.s_addr = inet_addr("192.168.3.221");
len = sizeof(addr);
setsockopt(server, IPPROTO_IP, IP_MULTICAST_IF, &addr, len);
printf("current if = %s\n", inet_ntoa(addr));
while( 1 )
{
len = sizeof(remote);
r = strlen(buf);
sendto(server, buf, r, 0, (struct sockaddr*)&remote, len);
sleep(1);
}
close(server);
return 0;
}