path: root/x11/xconsole/patches/patch-privsep_c

$OpenBSD$

Index: privsep.c
--- privsep.c.orig
+++ privsep.c
@@ -0,0 +1,268 @@
+/* $OpenBSD: privsep.c,v 1.7 2015/11/14 17:12:14 matthieu Exp $ */
+/*
+ * Copyright 2001 Niels Provos <provos@citi.umich.edu>
+ * All rights reserved.
+ *
+ * Copyright (c) 2002 Matthieu Herrb
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *    - Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *    - Redistributions in binary form must reproduce the above
+ *      copyright notice, this list of conditions and the following
+ *      disclaimer in the documentation and/or other materials provided
+ *      with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <sys/ioctl.h>
+#include <sys/uio.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#ifdef HAVE_UTIL_H
+#include <util.h>
+#endif
+#ifdef HAVE_PTY_H
+#inlude <pty.h>
+#endif
+
+#include "xconsole.h"
+
+enum cmd_types {
+	PRIV_OPEN_PTY,
+	PRIV_REDIRECT_CONSOLE,
+};
+
+
+static int priv_fd = -1;
+
+static void
+send_fd(int s, int fd)
+{
+	struct msghdr msg;
+	union {
+		struct cmsghdr hdr;
+		char buf[CMSG_SPACE(sizeof(int))];
+	} cmsgbuf;
+	struct cmsghdr *cmsg;
+	struct iovec vec;
+	int result = 0;
+	ssize_t n;
+
+	memset(&msg, 0, sizeof(msg));
+
+	if (fd >= 0) {
+		msg.msg_control = &cmsgbuf.buf;
+		msg.msg_controllen = sizeof(cmsgbuf.buf);
+		cmsg = CMSG_FIRSTHDR(&msg);
+		cmsg->cmsg_len = CMSG_LEN(sizeof(int));
+		cmsg->cmsg_level = SOL_SOCKET;
+		cmsg->cmsg_type = SCM_RIGHTS;
+		*(int *)CMSG_DATA(cmsg) = fd;
+	} else {
+		result = errno;
+	}
+
+	vec.iov_base = &result;
+	vec.iov_len = sizeof(int);
+	msg.msg_iov = &vec;
+	msg.msg_iovlen = 1;
+	
+	if ((n = sendmsg(s, &msg, 0)) == -1)
+		warn("%s: sendmsg(%d)", __func__, s);
+	if (n != sizeof(int))
+		warnx("%s: sendmsg: expected sent 1 got %ld",
+		    __func__, (long)n);
+}
+
+static int
+receive_fd(int s)
+{
+	struct msghdr msg;
+	union {
+		struct cmsghdr hdr;
+		char buf[CMSG_SPACE(sizeof(int))];
+	} cmsgbuf;
+	struct cmsghdr *cmsg;
+	struct iovec vec;
+	ssize_t n;
+	int result;
+	int fd;
+
+	memset(&msg, 0, sizeof(msg));
+	vec.iov_base = &result;
+	vec.iov_len = sizeof(int);
+	msg.msg_iov = &vec;
+	msg.msg_iovlen = 1;
+	msg.msg_control = &cmsgbuf.buf;
+	msg.msg_controllen = sizeof(cmsgbuf.buf);
+
+	if ((n = recvmsg(s, &msg, 0)) == -1)
+		warn("%s: recvmsg", __func__);
+	if (n != sizeof(int))
+		warnx("%s: recvmsg: expected received 1 got %ld",
+		    __func__, (long)n);
+	if (result == 0) {
+		cmsg = CMSG_FIRSTHDR(&msg);
+		if (cmsg->cmsg_type != SCM_RIGHTS)
+			warnx("%s: expected type %d got %d", __func__,
+			    SCM_RIGHTS, cmsg->cmsg_type);
+		fd = (*(int *)CMSG_DATA(cmsg));
+		return fd;
+	} else {
+		errno = result;
+		return -1;
+	}
+}
+
+int
+priv_init(uid_t uid, gid_t gid)
+{
+	int i, on, result, fd;
+	int pty, tty;
+	pid_t pid;
+	int socks[2];
+	int cmd;
+
+	/* Create sockets */
+	if (socketpair(AF_LOCAL, SOCK_STREAM, PF_UNSPEC, socks) == -1) {
+		return -1;
+	}
+	pid = fork();
+	if (pid < 0) {
+		/* can't fork */
+		return -1;
+	}
+	if (pid != 0) {
+		/* Father - drop privileges and return */
+		if (uid != -1 && gid != -1) {
+			if (setgroups(1, &gid) == -1)
+				return -1;
+
+			if (setresgid(gid, gid, gid) == -1)
+				return -1;
+			if (setresuid(uid, uid, uid) == -1)
+				return -1;
+		}
+		close(socks[0]);
+		priv_fd = socks[1];
+		return 0;
+	}
+	/* son */
+	for (i = 1; i <= _NSIG; i++) 
+		signal(i, SIG_DFL);
+#ifdef HAVE_SETPROCTILE
+	setproctitle("[priv]");
+#endif
+	close(socks[1]);
+
+	while (1) {
+		if (read(socks[0], &cmd, sizeof(int)) == 0) {
+			exit(0);
+		}
+		switch (cmd) {
+
+		case PRIV_OPEN_PTY:
+			if (openpty(&pty, &tty, NULL, NULL, NULL) == -1) {
+				warn("%s: openpty", __func__);
+				pty = -1;
+				tty = -1;
+			}
+			send_fd(socks[0], pty);
+			send_fd(socks[0], tty);
+			if (pty != -1) 
+				close(pty);
+			if (tty != -1) 
+				close(tty);
+			break;
+		case PRIV_REDIRECT_CONSOLE:
+			on = 1;
+			fd = receive_fd(socks[0]);
+			result = ioctl(fd, TIOCCONS, (char *) &on);
+			if (result < 0) {
+				warn("%s: ioctl(TIOCCONS)", __func__);
+			}
+			write(socks[0], &result, sizeof(int));
+			close(fd);
+			break;
+		default:
+			errx(1, "%s: unknown command %d", __func__, cmd);
+			break;
+		}
+	}
+	_exit(1);
+}
+
+/* Open pseudo-tty */
+int
+priv_openpty(int *pty_ptr, int *tty_ptr)
+{
+	int cmd;
+	int pty, tty;
+	
+	if (priv_fd != -1) {
+		cmd = PRIV_OPEN_PTY;
+		write(priv_fd, &cmd, sizeof(int));
+		pty = receive_fd(priv_fd);
+		tty = receive_fd(priv_fd);
+		if (tty < 0 || pty < 0) {
+			fprintf(stderr, "openpty: %d %d %d\n", 
+			    pty, tty, errno);
+			return -1;
+		}
+		if (pty_ptr != NULL) 
+			*pty_ptr = pty;
+		if (tty_ptr != NULL) 
+			*tty_ptr = tty;
+		return 0;
+	} else 
+		return openpty(pty_ptr, tty_ptr, NULL, NULL, NULL);
+}
+
+/* Redirect console output */
+int
+priv_set_console(int fd)
+{
+	int cmd;
+	int on, result;
+
+	if (priv_fd != -1) {
+		cmd = PRIV_REDIRECT_CONSOLE;
+		write(priv_fd, &cmd, sizeof(int));
+		send_fd(priv_fd, fd);
+		read(priv_fd, &result, sizeof(int));
+		return result;
+	} else {
+		on = 1;
+		return ioctl(fd, TIOCCONS, &on);
+	}
+}