根據以上介紹 , 我們寫出組播接收程序!
應用背景
wifi board 連接上級路由器,而後通過pc網絡調試助手向其發送組播數據 ! 組播地址ip 定位: 224.0.1.100, 在上面的理論介紹中,該地址爲:預留多播地址:在224.0.1.0~238.255.255.255之間,可用於全球範圍(如Internet)或網絡協議
int multicast_server_init(void)
{
int err = -1;
char buf[100]={0};
struct sockaddr_in local_addr; /*本地地址*/
struct sockaddr_in peer_addr;
struct stConfig *config = config_list();
ULOG_INFO("WIFI option : %s,%d\n",config->addr,config->port);
multicast_server_fd = socket(AF_INET, SOCK_DGRAM, 0); /*建立套接字*/
if (multicast_server_fd == -1)
{
perror("socket()");
return -1;
}
/*初始化地址*/
memset(&local_addr, 0, sizeof(local_addr));
local_addr.sin_family = AF_INET;
local_addr.sin_addr.s_addr = htonl(INADDR_ANY);
//local_addr.sin_port = htons(MCAST_PORT);
local_addr.sin_port = htons(config->port);
/*設置迴環許可*/
int loop = 1;
err = setsockopt(multicast_server_fd,IPPROTO_IP, IP_MULTICAST_LOOP,&loop, sizeof(loop));
if(err < 0)
{
perror("setsockopt():IP_MULTICAST_LOOP");
close(multicast_server_fd);
return -3;
}
bool bReuseaddr = true;
err = setsockopt(multicast_server_fd,SOL_SOCKET, SO_REUSEADDR,&bReuseaddr, &bReuseaddr);
if(err < 0)
{
perror("setsockopt():SOL_REUSEADDR");
close(multicast_server_fd);
return -3;
}
/*綁定socket*/
err = bind(multicast_server_fd,(struct sockaddr*)&local_addr, sizeof(local_addr)) ;
if(err < 0)
{
perror("bind()");
close(multicast_server_fd);
return -2;
}
struct ip_mreq mreq; /*加入多播組*/
//mreq.imr_multiaddr.s_addr = inet_addr(MCAST_ADDR); /*多播地址*/
mreq.imr_multiaddr.s_addr = inet_addr(config->addr); /*多播地址*/
mreq.imr_interface.s_addr = htonl(INADDR_ANY); /*網絡接口爲默認*/
membership:
memset(buf,0x0,100);
//通過wlan0-1路由數據,允許所有組播數據
sprintf(buf,"route add -net 224.0.1.100 netmask 255.255.255.255 wlan0-1");
system(buf);
/*將本機加入多播組*/
err = setsockopt(multicast_server_fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,&mreq, sizeof
(mreq));
if (err < 0)
{
perror("setsockopt():IP_ADD_MEMBERSHIP");
//return -4;
sleep(2);
goto membership;
}
return 0;
}
但該程序運行後,並不能友好的接收數據; 而後加入/usr/sbin/igmpproxy /var/etc/igmpproxy.conf , 路由組播接收數據穩定, 但是同時有兩個客戶端向其發送數據,則有一方不能正常通信, 通過重新初始化程序方能通信!
root@Leedarson:~# cat /etc/config/igmpproxy
config igmpproxy
option quickleave 1
config phyint wan
option network wwan
option direction upstream
list altnet 192.168.1.0/24
config phyint lan
option network lan
option direction downstream
其中,upstream 、 downstream 在我的項目中對應wlan0-1(station mode), br-lan 接口! 用於定向路由網絡組播數據!