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#include <sys/types.h>
#include <sys/socket.h> /* struct sockaddr */
#include <stdlib.h>
#include <netdb.h> /* gethostbyname() */
#include <netinet/in.h> /* sockaddr_in */
#include <arpa/inet.h> /* inet_addr() */
#include <rpcsvc/ypclnt.h> /* YP */
#include <ctype.h> /* isspace() */
#include "host2ip.h"
static char rcsid[] = "$Id: host2ip.c,v 1.1 1996/09/20 12:49:19 sho Exp $";
/*
* Return IP address given host name 'host'. Returns INADDR_ANY if not valid.
* NOTE: always include the correct function prototype,
* extern int host2ip(char *host);
* is not correct and will cause memory problems.
*/
struct in_addr host2ip(char *host)
{
struct in_addr in, tmp;
struct hostent *hep;
/* Strip leading white space. */
if (host) {
while (*host && isspace((int)*host)) host++;
}
/* Check whether this is a dotted decimal. */
if (!host) {
in.s_addr = INADDR_ANY;
}
else if ((tmp.s_addr = inet_addr(host)) != -1) {
in = tmp;
}
/* Attempt to resolve host name via DNS. */
else if ((hep = gethostbyname(host))) {
in = *(struct in_addr *)(hep->h_addr_list[0]);
}
/* As a last resort, try YP. */
else {
static char *domain = 0; /* YP domain */
char *value; /* key value */
int value_len; /* length of returned value */
if (!domain) yp_get_default_domain(&domain);
if (yp_match(domain, "hosts.byname", host, strlen(host), &value, &value_len) == 0) {
in.s_addr = inet_addr(value);
} else {
/* Everything failed */
in.s_addr = INADDR_ANY;
}
}
return in;
} /* host2ip */