getaddrinfo.c

getaddrinfo.c (text/plain), 1.31 KB, created by SpanKY on 2011-03-20 21:02:29 UTC

#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>

int main(int argc, char *argv[])
{
int i, port = 6600;

	printf("family: IPv4:%i IPv6:%i\n", PF_INET, PF_INET6);
	printf("proto: TCP:%i\n", IPPROTO_TCP);

for (i = 1; i < argc; ++i) {
char *hostname = argv[i];

	struct addrinfo hints;
	memset(&hints, 0, sizeof(hints));
	hints.ai_flags = AI_PASSIVE;
	hints.ai_family = PF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_protocol = IPPROTO_TCP;

	char service[20];
	snprintf(service, sizeof(service), "%u", port);

	struct addrinfo *ai;
	int ret = getaddrinfo(hostname, service, &hints, &ai);
	if (ret != 0) {
		perror("getaddrinfo");
		return 1;
	}

	for (const struct addrinfo *i = ai; i != NULL; i = i->ai_next) {
		struct sockaddr_in *sin = (void *)i->ai_addr;
		struct sockaddr_in6 *sin6 = (void *)i->ai_addr;
		char buf[256];
		void *src;

		src = (i->ai_family == PF_INET) ?
			(void *)&sin->sin_addr :
			(void *)&sin6->sin6_addr;

		printf("------ %s --------\n", hostname);
		printf("addr: %s canonname:%s\n",
			inet_ntop(i->ai_family, src, buf, 256),
			i->ai_canonname);
		printf("flags:%#x family:%i socktype:%i proto:%i\n",
			i->ai_flags, i->ai_family, i->ai_socktype, i->ai_protocol);
	}

	freeaddrinfo(ai);
}

return 0;
}