make file descriptor passing code return an error rather than call fatal()

when it encounters problems, and use this to make session multiplexing
masters survive slaves failing to pass all stdio FDs; ok markus@

1 files changed, 30 insertions, 14 deletions

diff --git a/usr.bin/ssh/monitor_fdpass.c b/usr.bin/ssh/monitor_fdpass.c
index cb2001e6d41..c760a2150b0 100644
--- a/usr.bin/ssh/monitor_fdpass.c
+++ b/usr.bin/ssh/monitor_fdpass.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: monitor_fdpass.c,v 1.12 2006/08/03 03:34:42 deraadt Exp $ */
+/* $OpenBSD: monitor_fdpass.c,v 1.13 2007/09/04 03:21:03 djm Exp $ */
 /*
  * Copyright 2001 Niels Provos <provos@citi.umich.edu>
  * All rights reserved.
@@ -35,7 +35,7 @@
 #include "log.h"
 #include "monitor_fdpass.h"
 
-void
+int
 mm_send_fd(int sock, int fd)
 {
 	struct msghdr msg;
@@ -59,12 +59,18 @@ mm_send_fd(int sock, int fd)
 	msg.msg_iov = &vec;
 	msg.msg_iovlen = 1;
 
-	if ((n = sendmsg(sock, &msg, 0)) == -1)
-		fatal("%s: sendmsg(%d): %s", __func__, fd,
+	if ((n = sendmsg(sock, &msg, 0)) == -1) {
+		error("%s: sendmsg(%d): %s", __func__, fd,
 		    strerror(errno));
-	if (n != 1)
-		fatal("%s: sendmsg: expected sent 1 got %ld",
+		return -1;
+	}
+
+	if (n != 1) {
+		error("%s: sendmsg: expected sent 1 got %ld",
 		    __func__, (long)n);
+		return -1;
+	}
+	return 0;
 }
 
 int
@@ -86,18 +92,28 @@ mm_receive_fd(int sock)
 	msg.msg_control = tmp;
 	msg.msg_controllen = sizeof(tmp);
 
-	if ((n = recvmsg(sock, &msg, 0)) == -1)
-		fatal("%s: recvmsg: %s", __func__, strerror(errno));
-	if (n != 1)
-		fatal("%s: recvmsg: expected received 1 got %ld",
+	if ((n = recvmsg(sock, &msg, 0)) == -1) {
+		error("%s: recvmsg: %s", __func__, strerror(errno));
+		return -1;
+	}
+
+	if (n != 1) {
+		error("%s: recvmsg: expected received 1 got %ld",
 		    __func__, (long)n);
+		return -1;
+	}
 
 	cmsg = CMSG_FIRSTHDR(&msg);
-	if (cmsg == NULL)
-		fatal("%s: no message header", __func__);
-	if (cmsg->cmsg_type != SCM_RIGHTS)
-		fatal("%s: expected type %d got %d", __func__,
+	if (cmsg == NULL) {
+		error("%s: no message header", __func__);
+		return -1;
+	}
+
+	if (cmsg->cmsg_type != SCM_RIGHTS) {
+		error("%s: expected type %d got %d", __func__,
 		    SCM_RIGHTS, cmsg->cmsg_type);
+		return -1;
+	}
 	fd = (*(int *)CMSG_DATA(cmsg));
 	return fd;
 }