unp_test/udpclisrv/udpsrv01.c

38 lines
935 B
C

#include "unp.h"
void dg_echo(int, SA*, socklen_t);
int main(int argc, char* argv[])
{
int sockfd;
struct sockaddr_in servaddr, cliaddr;
sockfd = Socket(AF_INET, SOCK_DGRAM, 0);
bzero(&servaddr, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
servaddr.sin_port = htons(SERV_PORT);
Bind(sockfd, (SA *)&servaddr, sizeof(servaddr));
dg_echo(sockfd, (SA *)&cliaddr, sizeof(cliaddr));
}
void dg_echo(int sockfd, SA *pcliaddr, socklen_t clien)
{
int n;
socklen_t len;
char msg[MAXLINE];
char res[MAXLINE];
char greeting[] = "This is from server: ";
for(;;) {
len = clien;
n = Recvfrom(sockfd, msg, MAXLINE, 0, pcliaddr, &len);
strcpy(res, "");
strncat(res, greeting, strlen(greeting));
strncat(res, msg, n);
Sendto(sockfd, res, strlen(res), 0, pcliaddr, len);
}
}