int main(int argc,char *argv[]) {
port=DEFAULT_PORT;
snprintf(userName,USERNAME_LEN,"%s",DEFAULT_USER);
int r=0;
timeLim=TIMEOUT_SEC;
while(1){
opt=getopt(argc,argv,"U:P:T:");
if(opt<0)break;
switch(opt){
case'U':
snprintf(userName,USERNAME_LEN,"%s",optarg);
break;
case 'P':
port=atoi(optarg);
break;
case 'T':
timeLim=atoi(optarg);
break;
}
}
printf("UserName:%s Port:%d BroadcastAddress:%s \n",userName,port,broadcastAddress);
r=callHELO(port);
int j;
if(r==0){//受信なし
fprintf(stderr,"Become Server\n");
j=executeAsServer();
}else if(r==1){//受信あり
fprintf(stderr,"Become Client\n");
j=executeAsClient();
}else{
exit_errmesg("HELO");
}
return 0;
}
int callHELO(){
struct sockaddr_in sockAddr;
int sock,sel;
int optval=1;
fd_set mask, readfds;
if((sock = socket(PF_INET, SOCK_DGRAM, 0)) == -1){//ソケットをDGRAMモードで作成する
exit_errmesg("socket()");
}
FD_ZERO(&mask);//ビットマスクの準備
FD_SET(sock, &mask);
sockAddr.sin_family = AF_INET;//ブロードキャストアドレスの情報をsockaddr_in構造体に格納する
sockAddr.sin_port = htons(port);
sockAddr.sin_addr.s_addr = inet_addr(limitedBroadcastAddress);
if(setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (void *)&optval, sizeof(optval)) == -1){
exit_errmesg("setsockopt()");
}
int i;
for(i=0;i<3;i++){
sendto(sock, "HELO", 5, 0, (struct sockaddr *)&sockAddr, sizeof(sockAddr));
readfds = mask;// 受信データの有無をチェック
// timeout.tv_sec = TIMEOUT_SEC;
timeout.tv_sec = timeLim;
timeout.tv_usec = 0;
sel=select( sock+1, &readfds, NULL, NULL, &timeout );
if(sel==-1){
exit_errmesg("select(HELO)");
}else if(sel==0){
printf("Time out[%d th].\n",i+1);
continue;
}else{
int strsize;
socklen_t from_len;
from_len = sizeof(from_adrs);
if((strsize=recvfrom(sock,Buf,10,0,(struct sockaddr *)&from_adrs, &from_len)) == -1){//form_adrsにIPアドレスを取得
exit_errmesg("recvfrom()");
}
close(sock);
if(strncmp(Buf,"HERE",4)==0){
return 1;
}
else return 0;
}
}
close(sock);
return 0;
}
int init_udpclient()
{
int sock;
/* ソケットをDGRAMモードで作成する */
if((sock = socket(PF_INET, SOCK_DGRAM, 0)) == -1){
exit_errmesg("socket()");
}
return(sock);
}
void set_sockaddr_in(struct sockaddr_in *server_adrs, char *servername, in_port_t port_number )
{
struct hostent *server_host;
/* サーバ名をアドレス(hostent構造体)に変換する */
if((server_host = gethostbyname( servername )) == NULL){
exit_errmesg("gethostbyname()");
}
/* サーバの情報をsockaddr_in構造体に格納する */
memset(server_adrs, 0, sizeof(struct sockaddr_in));
server_adrs->sin_family = AF_INET;
server_adrs->sin_port = htons(port_number);
memcpy(&(server_adrs->sin_addr), server_host->h_addr, server_host->h_length);
}
int main(int argc, char *argv[])
{
struct sockaddr_in broadcast_adrs;
struct sockaddr_in from_adrs;
socklen_t from_len;
int sock, count = 0;
int broadcast_sw = 1;
fd_set mask, readfds;
struct timeval timeout;
int port = DEFAULT_PORT;
char username[L_USERNAME] = "JohnDou";
char s_buf[S_BUFSIZE], r_buf[R_BUFSIZE];
int strsize = 0;
packet r_packet;
/* コマンドライン引数のチェックおよび使用法の表示 */
if(argc != 3)
{
fprintf(stderr, "Usage: %s User_name, Port_number\n", argv[0]);
exit(EXIT_FAILURE);
}
sprintf(username, "%s", argv[1]);
port = atoi(argv[2]);
set_sockaddr_in_broadcast(&broadcast_adrs, (in_port_t)port);
sock = init_udpclient();
if(setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (void *)&broadcast_sw, sizeof(broadcast_sw)) == 1)
{
exit_errmesg("setsockopt()");
}
FD_ZERO(&mask);
FD_SET(sock, &mask);
// s_buf にHELLOパケットを格納
create_packet(HELLO, s_buf);
strsize = sizeof(s_buf);
int i;
for(i = 0; i < 3; i++)
{
Sendto(sock, s_buf, strsize, 0, (struct sockaddr *)&broadcast_adrs, sizeof(broadcast_adrs));
readfds = mask;
timeout.tv_sec = TIMEOUT_SEC;
timeout.tv_usec = 0;
if(select(sock+1, &readfds, NULL, NULL, &timeout) == 0)
{
count++;
printf("Send HELLO packets %d times.\n", count);
printf("pct : %s\n", s_buf);
if(count == 3)
{
printf("There are no server, so you are server.\n");
server(username, port);
}
continue;
}
// HEREパケットを受信したときの処理
from_len = sizeof(from_adrs);
strsize = Recvfrom(sock, r_buf, R_BUFSIZE-1, 0, (struct sockaddr *)&from_adrs, &from_len);
r_packet = re_packet(r_buf);
if(analize_header(r_packet.header) == HERE)
{
printf("There are server, so you are client.\n");
client(username, from_adrs);
}
}
return 0;
}
