file descriptor passing abstraction for ssh-privsep

2 files changed, 118 insertions, 0 deletions

diff --git a/usr.bin/ssh/monitor_fdpass.c b/usr.bin/ssh/monitor_fdpass.c
new file mode 100644
index 00000000000..7785535bb8e
--- /dev/null
+++ b/usr.bin/ssh/monitor_fdpass.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright 2001 Niels Provos <provos@citi.umich.edu>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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 AUTHOR ``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 AUTHOR 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.
+ */
+
+#include "includes.h"
+RCSID("$OpenBSD: monitor_fdpass.c,v 1.1 2002/03/18 17:27:22 provos Exp $");
+
+#include <sys/uio.h>
+
+#include "log.h"
+#include "monitor_fdpass.h"
+
+void
+mm_send_fd(int socket, int fd)
+{
+	struct msghdr msg;
+	char tmp[CMSG_SPACE(sizeof(int))];
+	struct cmsghdr *cmsg;
+	struct iovec vec;
+	char ch;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.msg_control = (caddr_t)tmp;
+	msg.msg_controllen = CMSG_LEN(sizeof(int));
+	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;
+
+	vec.iov_base = &ch;
+	vec.iov_len = 1;
+	msg.msg_iov = &vec;
+	msg.msg_iovlen = 1;
+
+	if (sendmsg(socket, &msg, 0) == -1)
+		fatal("%s: sendmsg(%d)", __FUNCTION__, fd);
+}
+
+int
+mm_receive_fd(int socket)
+{
+	struct msghdr msg;
+	char tmp[CMSG_SPACE(sizeof(int))];
+	struct cmsghdr *cmsg;
+	struct iovec vec;
+	char ch;
+
+	memset(&msg, 0, sizeof(msg));
+	vec.iov_base = &ch;
+	vec.iov_len = 1;
+	msg.msg_iov = &vec;
+	msg.msg_iovlen = 1;
+	msg.msg_control = tmp;
+	msg.msg_controllen = sizeof(tmp);
+
+	if (recvmsg(socket, &msg, 0) == -1)
+		fatal("%s: recvmsg", __FUNCTION__);
+
+	cmsg = CMSG_FIRSTHDR(&msg);
+	if (cmsg->cmsg_type != SCM_RIGHTS)
+		fatal("%s: expected type %d got %d", __FUNCTION__,
+		    SCM_RIGHTS, cmsg->cmsg_type);
+	return (*(int *)CMSG_DATA(cmsg));
+}
diff --git a/usr.bin/ssh/monitor_fdpass.h b/usr.bin/ssh/monitor_fdpass.h
new file mode 100644
index 00000000000..cb6b71c93ac
--- /dev/null
+++ b/usr.bin/ssh/monitor_fdpass.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2002 Niels Provos <provos@citi.umich.edu>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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 AUTHOR ``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 AUTHOR 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.
+ */
+
+#ifndef _MM_FDPASS_H_
+#define _MM_FDPASS_H_
+
+void mm_send_fd(int, int);
+int mm_receive_fd(int);
+
+#endif /* _MM_FDPASS_H_ */