int do_connect(int type)
{
int sock = 0;
if (type != SOCK_STREAM && type != SOCK_DGRAM)
return -1;
/* We need a socket that can be inherited by child processes in
ncat_exec_win.c, for --exec and --sh-exec. inheritable_socket is from
nbase. */
sock = inheritable_socket(targetss.storage.ss_family, type, 0);
if (srcaddr.storage.ss_family != AF_UNSPEC) {
size_t sa_len;
#ifdef HAVE_SOCKADDR_SA_LEN
sa_len = srcaddr.sockaddr.sa_len;
#else
sa_len = sizeof(srcaddr);
#endif
if (bind(sock, &srcaddr.sockaddr, sa_len) < 0) {
bye("bind to %s:%hu: %s.", inet_socktop(&srcaddr),
inet_port(&srcaddr), socket_strerror(socket_errno()));
}
}
if (sock != -1) {
if (connect(sock, &targetss.sockaddr, (int) targetsslen) != -1)
return sock;
else if (socket_errno() == EINPROGRESS || socket_errno() == EAGAIN)
return sock;
}
return -1;
}
/* Create the actual socket (nse->iod->sd) underlying the iod. This unblocks the
* socket, binds to the localaddr address, sets IP options, and sets the
* broadcast flag. Trying to change these functions after making this call will
* not have an effect. This function needs to be called before you try to read
* or write on the iod. */
static int nsock_make_socket(struct npool *ms, struct niod *iod, int family, int type, int proto) {
/* inheritable_socket is from nbase */
iod->sd = (int)inheritable_socket(family, type, proto);
if (iod->sd == -1) {
nsock_log_error("Socket trouble: %s", socket_strerror(socket_errno()));
return -1;
}
unblock_socket(iod->sd);
iod->lastproto = proto;
if (iod->locallen)
mksock_bind_addr(ms, iod);
if (iod->ipoptslen && family == AF_INET)
mksock_set_ipopts(ms, iod);
if (ms->device)
mksock_bind_device(ms, iod);
if (ms->broadcast && type != SOCK_STREAM)
mksock_set_broadcast(ms, iod);
/* mksock_* functions can raise warnings/errors
* but we don't let them stop us for now. */
return iod->sd;
}
/* Return a listening socket after setting various characteristics on it.
Returns -1 on error. */
int do_listen(int type, int proto, const union sockaddr_u *srcaddr_u)
{
int sock = 0, option_on = 1;
size_t sa_len;
if (type != SOCK_STREAM && type != SOCK_DGRAM)
return -1;
/* We need a socket that can be inherited by child processes in
ncat_exec_win.c, for --exec and --sh-exec. inheritable_socket is from
nbase. */
sock = inheritable_socket(srcaddr_u->storage.ss_family, type, proto);
if (sock < 0)
return -1;
Setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &option_on, sizeof(int));
/* IPPROTO_IPV6 is defined in Visual C++ only when _WIN32_WINNT >= 0x501.
Nbase's nbase_winunix.h defines _WIN32_WINNT to a lower value for
compatibility with older versions of Windows. This code disables IPv6 sockets
that also receive IPv4 connections. This is the default on Windows anyway so
it doesn't make a difference.
http://support.microsoft.com/kb/950688
http://msdn.microsoft.com/en-us/library/bb513665
*/
#ifdef IPPROTO_IPV6
#ifdef IPV6_V6ONLY
if (srcaddr_u->storage.ss_family == AF_INET6) {
int set = 1;
/* Tell it to not try and bind to IPV4 */
if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &set, sizeof(set)) == -1)
die("Unable to set IPV6 socket to bind only to IPV6");
}
#endif
#endif
#ifdef HAVE_SYS_UN_H
if (srcaddr_u->storage.ss_family == AF_UNIX)
sa_len = SUN_LEN(&srcaddr_u->un);
else
#endif
#ifdef HAVE_SOCKADDR_SA_LEN
sa_len = srcaddr_u->sockaddr.sa_len;
#else
sa_len = sizeof(*srcaddr_u);
#endif
if (bind(sock, &srcaddr_u->sockaddr, sa_len) < 0) {
#ifdef HAVE_SYS_UN_H
if (srcaddr_u->storage.ss_family == AF_UNIX)
bye("bind to %s: %s.", srcaddr_u->un.sun_path,
socket_strerror(socket_errno()));
else
#endif
bye("bind to %s:%hu: %s.", inet_socktop(srcaddr_u),
inet_port(srcaddr_u), socket_strerror(socket_errno()));
}
if (type == SOCK_STREAM)
Listen(sock, BACKLOG);
if (o.verbose) {
#ifdef HAVE_SYS_UN_H
if (srcaddr_u->storage.ss_family == AF_UNIX)
loguser("Listening on %s\n", srcaddr_u->un.sun_path);
else
#endif
loguser("Listening on %s:%hu\n", inet_socktop(srcaddr_u), inet_port(srcaddr_u));
}
if (o.test)
logtest("LISTEN\n");
return sock;
}
