openssh_without_fdpass.patch

diff --git a/mux.c b/mux.c
index cdc01bd..8a811a9 100644
--- a/mux.c
+++ b/mux.c
@@ -146,6 +147,7 @@ struct mux_master_state {
 #define MUX_C_CLOSE_FWD		0x10000007
 #define MUX_C_NEW_STDIO_FWD	0x10000008
 #define MUX_C_STOP_LISTENING	0x10000009
+#define MUX_C_FDPASS		0x1000000A
 #define MUX_S_OK		0x80000001
 #define MUX_S_PERMISSION_DENIED	0x80000002
 #define MUX_S_FAILURE		0x80000003
@@ -172,6 +174,15 @@ static int process_mux_close_fwd(u_int, Channel *, Buffer *, Buffer *);
 static int process_mux_stdio_fwd(u_int, Channel *, Buffer *, Buffer *);
 static int process_mux_stop_listening(u_int, Channel *, Buffer *, Buffer *);
 
+#ifdef HAVE_CYGWIN
+int muxfd[3];
+char *muxsock[3];
+
+static int mux_client_fdpass(int, int, int);
+static int process_mux_fdpass(int);
+static int mux_redirect(int, int);
+#endif
+
 static const struct {
 	u_int type;
 	int (*handler)(u_int, Channel *, Buffer *, Buffer *);
@@ -372,11 +383,22 @@ process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r)
 	cmd = NULL;
 
 	/* Gather fds from client */
+#ifdef HAVE_CYGWIN
+	for(i = 1; i < 3; i++) {
+		if ((new_fd[i] = process_mux_fdpass(c->sock)) >= 0) {
+			new_fd[0] = new_fd[1]; // stdin and stdout is going through the same socket
+		} else {
+#else
 	for(i = 0; i < 3; i++) {
 		if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
+#endif
 			error("%s: failed to receive fd %d from slave",
 			    __func__, i);
+#ifdef HAVE_CYGWIN
+			for (j = 1; j < i; j++)
+#else
 			for (j = 0; j < i; j++)
+#endif
 				close(new_fd[j]);
 			for (j = 0; j < env_len; j++)
 				free(cctx->env[j]);
@@ -434,6 +456,8 @@ process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r)
 	/* Try to pick up ttymodes from client before it goes raw */
 	if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
 		error("%s: tcgetattr: %s", __func__, strerror(errno));
+	// TODO tcgetattr fails on socket. We can send attributes
+	// the same way we send the rest information???
 
 	/* enable nonblocking unless tty */
 	if (!isatty(new_fd[0]))
@@ -958,11 +982,22 @@ process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
 	    __func__, c->self, chost, cport);
 
 	/* Gather fds from client */
+#ifdef HAVE_CYGWIN
+	for(i = 1; i < 2; i++) {
+		if ((new_fd[i] = process_mux_fdpass(c->sock)) >= 0) {
+			new_fd[0] = new_fd[1]; // stdin and stdout is going through the same socket
+		} else {
+#else
 	for(i = 0; i < 2; i++) {
 		if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) {
+#endif
 			error("%s: failed to receive fd %d from slave",
 			    __func__, i);
+#ifdef HAVE_CYGWIN
+			for (j = 1; j < i; j++)
+#else
 			for (j = 0; j < i; j++)
+#endif
 				close(new_fd[j]);
 			free(chost);
 
@@ -1842,9 +1877,14 @@ mux_client_request_session(int fd)
 		fatal("%s: write packet: %s", __func__, strerror(errno));
 
 	/* Send the stdio file descriptors */
+#ifdef HAVE_CYGWIN
+	if (mux_client_fdpass(fd, STDIN_FILENO, STDOUT_FILENO) == -1 ||
+	    mux_client_fdpass(fd, -1, STDERR_FILENO) == -1)
+#else
 	if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
 	    mm_send_fd(fd, STDOUT_FILENO) == -1 ||
 	    mm_send_fd(fd, STDERR_FILENO) == -1)
+#endif
 		fatal("%s: send fds failed", __func__);
 
 	debug3("%s: session request sent", __func__);
@@ -1894,6 +1934,52 @@ mux_client_request_session(int fd)
 	if (tty_flag)
 		enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 
+#ifdef HAVE_CYGWIN
+	fd_set readset, activeset;
+	int maxfd, res, fds = 3;
+	FD_ZERO(&readset);
+	FD_SET(STDIN_FILENO, &readset);
+	FD_SET(muxfd[1], &readset);
+	if (muxfd[2] > -1)
+		FD_SET(muxfd[2], &readset);
+	FD_SET(fd, &readset);
+	maxfd = MAX(MAX(muxfd[1], muxfd[2]), fd);
+	for (exitval = 255, exitval_seen = 0;;) {
+		activeset = readset;
+		res = select(maxfd+1, &activeset, NULL, NULL, NULL);
+		//debug3("select returned %d\n", res);
+		if (res < 0) {
+			perror ("select");
+			break;
+		} else {
+			if (FD_ISSET(STDIN_FILENO, &activeset))
+				if (mux_redirect(STDIN_FILENO, muxfd[1]) == 0) {
+					shutdown(muxfd[1], SHUT_WR);
+					FD_CLR(STDIN_FILENO, &readset);
+					fds--;
+				}
+			if (FD_ISSET(muxfd[1], &activeset))
+				if (mux_redirect(muxfd[1], STDOUT_FILENO) == 0) {
+					FD_CLR(muxfd[1], &readset);
+					fds--;
+				}
+			if (FD_ISSET(muxfd[2], &activeset))
+				if (mux_redirect(muxfd[2], STDERR_FILENO) == 0) {
+					FD_CLR(muxfd[2], &readset);
+					fds--;
+				}
+			/*
+			 * FAILSAFE: broken protocol? -- the exit message is not always present
+			 *   jump to cleanup also when there are no other active FDs
+			 */
+			if (FD_ISSET(fd, &activeset) || fds < 1) {
+				goto handle_messages;
+			}
+			continue;
+		}
+handle_messages:
+#else
+
 	/*
 	 * Stick around until the controlee closes the client_fd.
 	 * Before it does, it is expected to write an exit message.
@@ -1902,6 +1988,8 @@ mux_client_request_session(int fd)
 	 * terminate early too (possibly losing data).
 	 */
 	for (exitval = 255, exitval_seen = 0;;) {
+#endif
+		//logit("--> Starting to handle messages since I got that read from select");
 		buffer_clear(&m);
 		if (mux_client_read_packet(fd, &m) != 0)
 			break;
@@ -1932,6 +2020,17 @@ mux_client_request_session(int fd)
 		}
 	}
 
+#ifdef HAVE_CYGWIN
+	debug3("%s: cleaning up file descriptors", __func__);
+	for(i = 1; i < 3; i++) {
+		close(muxfd[i]);
+		if (muxsock[i] != NULL) {
+			unlink(muxsock[i]);
+			free(muxsock[i]);
+		}
+	}
+#endif
+
 	close(fd);
 	if (rawmode)
 		leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
@@ -1988,8 +2087,12 @@ mux_client_request_stdio_fwd(int fd)
 		fatal("%s: write packet: %s", __func__, strerror(errno));
 
 	/* Send the stdio file descriptors */
+#ifdef HAVE_CYGWIN
+	if (mux_client_fdpass(fd, STDIN_FILENO, STDOUT_FILENO) == -1)
+#else
 	if (mm_send_fd(fd, STDIN_FILENO) == -1 ||
 	    mm_send_fd(fd, STDOUT_FILENO) == -1)
+#endif
 		fatal("%s: send fds failed", __func__);
 
 	debug3("%s: stdio forward request sent", __func__);
@@ -2198,3 +2301,128 @@ muxclient(const char *path)
 		fatal("unrecognised muxclient_command %d", muxclient_command);
 	}
 }
+
+#ifdef HAVE_CYGWIN
+static int
+mux_client_fdpass(int fd, int fdpass_in, int fdpass_out)
+{
+	Buffer m;
+	char rbuf[16+1];
+	char *path;
+	char r;
+	int ffd, sock, t;
+	size_t i;
+	struct sockaddr_un remote;
+
+	debug3("%s: entering", __func__);
+
+	for (i = 0; i < sizeof(rbuf) - 1; i++) {
+		r = arc4random_uniform(26+26+10);
+		rbuf[i] = (r < 26) ? 'a' + r :
+		    (r < 26*2) ? 'A' + r - 26 :
+		    '0' + r - 26 - 26;
+	}
+	rbuf[sizeof(rbuf) - 1] = '\0';
+	if (asprintf(&path, "%s.fdpass.%s", options.control_path, rbuf) < 0) {
+		error("%s: asprintf: %s", __func__, strerror(errno));
+		return -1;
+	}
+	if ((sock = unix_listener(path, 2, 0)) < 0) {
+		free(path);
+		error("%s: socket: %s", __func__, strerror(errno));
+		return -1;
+	}
+	debug3("%s: emulating fdpass through socket %s", __func__, path);
+
+	buffer_init(&m);
+	buffer_put_int(&m, MUX_C_FDPASS);
+	buffer_put_cstring(&m, path);
+	if (mux_client_write_packet(fd, &m) != 0) {
+		free(path);
+		buffer_free(&m);
+		error("%s: failed to write packet to mux", __func__);
+		return -1;
+	}
+	buffer_free(&m);
+
+	//printf("muxfd[%d] = %d\n", fdpass, ffd);
+	if ((ffd = accept(sock, (struct sockaddr *)&remote, &t)) < 0) {
+		free(path);
+		error("%s: accept: %s", __func__, strerror(errno));
+		return -1;
+	}
+	debug3("%s: accepted client on socket %s", __func__, path);
+
+	muxfd[fdpass_out] = ffd; // stores only 1=>I/O 2=>ERR
+	muxsock[fdpass_out] = path;
+
+	return 0;
+}
+
+static int
+process_mux_fdpass(int fd)
+{
+	Buffer m;
+	int msg_id, sock, len;
+	char *path;
+	u_int n;
+	struct sockaddr_un remote;
+
+	buffer_init(&m);
+	if (mux_client_read_packet(fd, &m) != 0) {
+		buffer_free(&m);
+		return -1;
+	}
+
+	msg_id = buffer_get_int(&m);
+	path = buffer_get_cstring(&m, &n);
+	buffer_free(&m);
+	if (msg_id != MUX_C_FDPASS)
+		error("%s: Received wrong message id instead of passed socket", __func__);
+
+	debug3("%s: received socket %s to emulate fdpass", __func__, path);
+	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
+		error("%s: socket: %s", __func__, strerror(errno));
+		return -1;
+	}
+	memset(&remote, '\0', sizeof(remote));
+	remote.sun_family = AF_UNIX;
+	if (strlcpy(remote.sun_path, path,
+	    sizeof(remote.sun_path)) >= sizeof(remote.sun_path)) {
+		error("ControlPath too long");
+		return -1;
+	}
+	len = offsetof(struct sockaddr_un, sun_path) + strlen(path) + 1;
+	if (connect(sock, (struct sockaddr *)&remote, len) < 0) {
+		error("%s: connect: %s", __func__, strerror(errno));
+		return -1;
+	}
+
+	free(path);
+	return sock;
+}
+
+static int mux_redirect(int source, int target)
+{
+	static char buffer[SSH_IOBUFSZ+1];
+	int result;
+	do {
+		result = read(source, buffer, SSH_IOBUFSZ);
+	} while (result == -1 && errno == EINTR);
+
+	if (result > 0) {
+		result = write(target, buffer, result);
+		//buffer[result] = 0;
+		//debug3("Redirecting %d -> %d data: %s\n", source, target, buffer);
+		return result; // written size
+	} else if (result == 0) {
+		//close, FD_CLEAR
+		//printf("Closing fd %d\n", source);
+		//close(target); // can't close socket yet since it is both way
+		return result; // propagete information about closing fd
+	} else {
+		printf("Error in read(): %s\n", strerror(errno));
+		return -1;
+	}
+}
+#endif