/* getaddrinfo.c : PUBLIC DOMAIN - Jon Mayo - August 14, 2006
 * - You may remove any comments you wish, modify this code any way you wish,
 *   and distribute any way you wish.
 */
/* generic networking routines */

#include <assert.h>
#include <netdb.h>
#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>

struct net_handler { 
	void (*connect_handler)(void *p, int fd, const char *addr, const char *serv);
	void *connect_p;
	void (*io_handler)(int fd, short ev, void *p);
	void *io_p;
};

static int net_lookup(const char *host, const char *sport, const char *pname, int (*foreach)(void *p, struct addrinfo *ai, const char *addr, const char *serv), void *p) {
	struct protoent *pe;
	struct addrinfo *ai, hint, *curr;
	int proto;
	int res;
	assert(foreach != NULL);
	fprintf(stderr, "net_lookup(%s, %s, %s)\n", host, sport, pname);
	if(pname) {
		pe=getprotobyname(pname);
		proto=pe ? pe->p_proto :  0;
	} else {
		proto=0;
	}
	if(host && !host[0]) host=0;
	if(sport && !sport[0]) sport=0;

	hint.ai_flags=AI_ADDRCONFIG|AI_PASSIVE;
	hint.ai_family=PF_UNSPEC;
	hint.ai_socktype=0; /* set to SOCK_STREAM if you do not want UDP */
	hint.ai_protocol=proto;
	hint.ai_addrlen=0;
	hint.ai_addr=0;
	hint.ai_canonname=0;
	hint.ai_next=0;

	if((res=getaddrinfo(host, sport, &hint, &ai))) {
		fprintf(stderr, "getaddrinfo(): %s\n", gai_strerror(res));
		if(res==EAI_SYSTEM) {
			perror("getaddrinfo()");
		}
		return 0;
	}
	curr=ai;
	if(!curr) {
		fprintf(stderr, "no entries!\n"); 
		return 0; 
	}

	for(; curr; curr=curr->ai_next) {
		char addr[NI_MAXHOST];
		char serv[NI_MAXSERV];
		int res;
		if((res=getnameinfo(curr->ai_addr, curr->ai_addrlen, addr, sizeof addr, serv, sizeof serv, NI_NUMERICHOST))) {
			/* Failed */
			if(res==EAI_SYSTEM) {
				perror("getnameinfo()");
			} else {
				fprintf(stderr, "getnameinfo(): %s\n", gai_strerror(res));
			}
			continue;
		}
		if(!foreach(p, curr, addr, serv)) {
			freeaddrinfo(ai);
			return 0;
		}
	}
	freeaddrinfo(ai);
	return 1;
}

#ifdef STAND_ALONE
int dump_entry(void *p, struct addrinfo *ai, const char *addr, const char *serv) {
	int s;

	assert(ai != NULL);

	fprintf(stderr, "family: %u\tsocktype: %u\tprotocol: %u\taddr: %s/%s\n", ai->ai_family, ai->ai_socktype, ai->ai_protocol, addr, serv);

	/* example of using the addrinfo structure to create a socket to use
	 * with bind() or connect(). */
	s=socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
	if (s < 0) {
		perror("socket()");
		return 0;
	}
	/* TODO: now do something with s */

	return 1;
}

/* usage:
 * 	getaddrinfo <host> [<port> [tcp|udp]]
 */
int main(int argc, char **argv) {
	const char *sport, *host, *proto;

	host = (argc>1) ? argv[1] : "";
	sport = (argc>2) ? argv[2] : "23";
	proto = (argc>3) ? argv[3] : "tcp";
	
	fprintf(stderr, "Host '%s' on port '%s' using '%s'\n", host, sport, proto);	
	net_lookup(host, sport, proto, dump_entry, 0);
	return 0;
}
#endif