我正在尝试使用以下代码连接到多播组:
int flag_on = 1; /* socket option flag */
struct sockaddr_in mc_addr; /* socket address structure */
char recv_str[MAX_LEN+1]; /* buffer to receive string */
int recv_len; /* length of string received */
char* mc_addr_str; /* multicast IP address */
unsigned short mc_port; /* multicast port */
struct sockaddr_in from_addr; /* packet source */
unsigned int from_len; /* source addr length */
mc_addr_str = ip; /* arg 1: multicast ip address */
mc_port = port; /* arg 2: multicast port number */
/* validate the port range */
if ((mc_port < MIN_PORT) || (mc_port > MAX_PORT)) {
fprintf(stderr, "Invalid port number argument %d.\n",
mc_port);
fprintf(stderr, "Valid range is between %d and %d.\n",
MIN_PORT, MAX_PORT);
exit(1);
}
/* create socket to join multicast group on */
// if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
if ((sock = socket(AF_INET, SOCK_DGRAM,IPPROTO_UDP)) < 0) {
perror("socket() failed");
LOGE("*********Inside Join Multicast -- socket() failed*********");
exit(1);
}
LOGE("Socket value = %d ",sock);
/* set reuse port to on to allow multiple binds per host */
if ((setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &flag_on,
sizeof(flag_on))) < 0) {
perror("setsockopt() failed");
LOGE("*********Inside Join Multicast -- socketopt() failed*********");
exit(1);
}
/* construct a multicast address structure */
memset(&mc_addr, 0, sizeof(mc_addr));
mc_addr.sin_family = AF_INET;
mc_addr.sin_addr.s_addr = htonl(INADDR_ANY);
mc_addr.sin_port = htons(mc_port);
/* bind to multicast address to socket */
if ((bind(sock, (struct sockaddr *) &mc_addr,
sizeof(mc_addr))) < 0) {
perror("bind() failed");
LOGE("*********Inside Join Multicast -- bind() failed*********");
exit(1);
}
/* construct an IGMP join request structure */
mc_req.imr_multiaddr.s_addr = inet_addr(mc_addr_str);
mc_req.imr_interface.s_addr = htonl(INADDR_ANY);
/* send an ADD MEMBERSHIP message via setsockopt */
if ((setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
(void*) &mc_req, sizeof(mc_req))) < 0) {
perror("setsockopt() failed");
LOGE("*********Inside Join Multicast -- socketopt2() failed*********");
LOGE("Value of errno is %s",strerror(errno));
exit(1);
}
我收到的错误是errno的值为“没有这样的设备”。
我正在尝试在omap板上实现这个目标 - 已经移植了GB。
请帮忙解决问题,谢谢。
joinGroup(group)
会失败,并显示错误消息“没有这样的设备”。 - praneetloke