a random port is chosen while initing socket [closed] - c

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int create_socket(struct in_addr *ip, unsigned int port) {
int s = socket(AF_INET, SOCK_STREAM, 0);
struct sockaddr_in sin;
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_port = (port);
sin.sin_addr.s_addr = ip;
connect(s, &sin, sizeof(sin));
return s;
}
I try to create socket to connect to of my server, and whenever I run this code the process tries to connect to a random socket.
the function is called with the following parameters:
inet_aton(argv[1], &ip); //argv[1]=='127.0.0.1'
unsigned int port = htons(atoi(argv[2])); //argv[2]=='8080'
Anyone detects the mistake?

Answer 1

The problem was with this:
int create_socket(struct in_addr *ip, unsigned int port) {
int s = socket(AF_INET, SOCK_STREAM, 0);
struct sockaddr_in sin;
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_port = (port);
sin.sin_addr.s_addr =ip->s_addr; // this is where the problem was
err_handler(connect(s, (struct sockaddr *)&sin, sizeof(sin)));
return s;
}

Answer 2

Try something more like this:
int create_socket(struct in_addr *ip, unsigned short port) {
int s = socket(AF_INET, SOCK_STREAM, 0);
if (s < 0) return -1;
struct sockaddr_in sin;
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_port = htons(port);
sin.sin_addr.s_addr = ip->s_addr;
if (connect(s, &sin, sizeof(sin)) < 0) {
close(s);
s = -1;
}
return s;
}
struct in_addr ip;
inet_aton(argv[1], &ip); //argv[1]=="127.0.0.1"
unsigned short port = atoi(argv[2]); //argv[2]=="8080"
int sckt = create_socket(&ip, port);
if (sckt < 0) {
...
}
else {
...
close(sckt);
}
A better option is to use getaddrinfo() instead, let it do all the parsing and setup of the sockaddr_in for you:
int create_socket(const char *ip, const char *port) {
struct addrinfo hints, *addrs, *addr;
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_INET;
hints.ai_socktype = SOCK_STREAM;
int res = getaddrinfo(ip, port, &hints, &addrs);
if (res < 0) {
return -1;
}
for(addr = addrs; addr != NULL; addr = addr->ai_next) {
int s = socket(addr->ai_family, addr->ai_socktype, addr->ai_protocol);
if (s < 0) continue;
if (connect(s, addr->ai_addr, addr->ai_addrlen) == 0) {
freeaddrinfo(addrs);
return s;
}
close(s);
}
freeaddrinfo(addrs);
return -1;
}
int sckt = create_socket(argv[1], argv[2]);
if (sckt < 0) {
...
}
else {
...
close(sckt);
}