Jak ustawić port źródłowy w gnieździe UDP wc?

Question

Czy ktoś może mi powiedzieć, jak ustawić adres portu źródłowego w gnieździe UDP? Moja aplikacja kliencka musi wysłać pakiety z portu 57002 do portu 58007 serwera.

Answer 1

bind(2) it. Użyj adresu INADDR_ANY i numeru portu.

Answer 2

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)); 

Answer 3

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 

Answer 4

#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; 
}