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/* The GPL applies to this program.
In addition, as a special exception, the copyright holders give
permission to link the code of portions of this program with the
OpenSSL library under certain conditions as described in each
individual source file, and distribute linked combinations
including the two.
You must obey the GNU General Public License in all respects
for all of the code used other than OpenSSL. If you modify
file(s) with this exception, you may extend this exception to your
version of the file(s), but you are not obligated to do so. If you
do not wish to do so, delete this exception statement from your
version. If you delete this exception statement from all source
files in the program, then also delete it here.
*/
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "io.h"
#include "tcp.h"
int connect_to(char *host, int portnr, int timeout)
{
int fd;
int loop;
struct sockaddr_in addr;
struct hostent *hostdnsentries;
/* create socket */
fd = socket(AF_INET, SOCK_STREAM, 0);
if (fd == -1)
{
perror("problem creating socket ");
return -1;
}
hostdnsentries = gethostbyname(host);
if (hostdnsentries == NULL)
{
fprintf(stderr, "could not resolve %s:%d: %s\n", host, portnr, strerror(errno));
close(fd);
return -1;
}
/* initialize address structure */
memset((void *)&addr, 0, sizeof(addr));
addr.sin_port = htons(portnr);
addr.sin_family = hostdnsentries -> h_addrtype;
/* make fd nonblocking */
if (set_fd_nonblocking(fd) == -1)
return -1;
/* try to connect for each of the entries: */
for(loop=0; ; loop++)
{
int rc;
struct timeval to;
fd_set wfds;
/* end of list with hosts? */
if ((hostdnsentries -> h_addr_list[loop]) == NULL)
break;
/* create address structure */
addr.sin_addr = incopy(hostdnsentries -> h_addr_list[loop]);
/* wait for connection */
FD_ZERO(&wfds);
FD_SET(fd, &wfds);
to.tv_sec = timeout / 1000;
to.tv_usec = (timeout - (to.tv_sec * 1000)) * 1000;
/* connect to peer */
if (connect(fd, (struct sockaddr *)&addr, sizeof(addr)) == 0)
{
/* connection made, return */
return fd;
}
/* wait for connection */
rc = select(fd + 1, NULL, &wfds, NULL, &to);
if (rc == 0)
return -2; /* timeout */
else if (rc == -1)
{
if (errno == EINTR)
return -3; /* ^C pressed */
else
return -1; /* error */
}
else
{
int optval=0;
int optvallen=sizeof(optval);
/* see if the connect succeeded or failed */
if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &optval, &optvallen) == -1)
return -1;
/* no error? */
if (optval == 0)
return fd;
/* don't ask */
errno = optval;
}
}
close(fd);
fprintf(stderr, "could not connect to %s:%d: %s\n", host, portnr, strerror(errno));
return -1;
}
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