UDPソケットに送信元ポートアドレスを設定する方法を教えてもらえますか?クライアントアプリケーションは、57002ポートからサーバーポート58007にパケットを送信する必要があります。
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#define DST_PORT 58007
#define SRC_PORT 57002
#define IP "127.0.0.1"
int main(int argc, char *argv[]) {
struct sockaddr_in addr, srcaddr;
int fd;
char message[] = "Hello, World!";
if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
perror("socket");
exit(1);
}
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = inet_addr(IP);
addr.sin_port = htons(DST_PORT);
memset(&srcaddr, 0, sizeof(srcaddr));
srcaddr.sin_family = AF_INET;
srcaddr.sin_addr.s_addr = htonl(INADDR_ANY);
srcaddr.sin_port = htons(SRC_PORT);
if (bind(fd, (struct sockaddr *) &srcaddr, sizeof(srcaddr)) < 0) {
perror("bind");
exit(1);
}
while (1) {
if (sendto(fd, message, sizeof(message), 0, (struct sockaddr *) &addr,
sizeof(addr)) < 0) {
perror("sendto");
exit(1);
}
sleep(1);
}
return 0;
}
bind(2)
それ。使用する - INADDR_ANY
アドレスとポート番号。
struct sockaddr_in servaddr,cliaddr;
sockfd=socket(AF_INET,SOCK_DGRAM,0);
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr=inet_addr(argv[1]);
servaddr.sin_port=htons(32000); //destination port for incoming packets
cliaddr.sin_family = AF_INET;
cliaddr.sin_addr.s_addr= htonl(INADDR_ANY);
cliaddr.sin_port=htons(33000); //source port for outgoing packets
bind(sockfd,(struct sockaddr *)&cliaddr,sizeof(cliaddr));
use sendto with servaddr
use recvfrom with cliaddr
if u check wireshark u will see source port as 33000 and destination port as 32000 for sendto operation
struct sockaddr_in sa;
int ret, fd;
memset(&sa, 0, sizeof(struct sockaddr_in));
sa.sin_family = AF_INET;
sa.sin_port = htons(LOCAL_PORT);
sa.sin_addr.s_addr = inet_addr(LOCAL_IP_ADDRESS);
ret = bind(fd, (struct sockaddr *)&sa, sizeof(struct sockaddr));