Make sure cmsgbufs are properly aligned by using the idiom from the

CMSG_DATA man page. Avoids SIGBUS on landisk; ok kettenis@ jca@

1 files changed, 15 insertions, 5 deletions

diff --git a/usr.bin/dig/lib/isc/unix/socket.c b/usr.bin/dig/lib/isc/unix/socket.c
index 0a2ea57e29e..dd803bc27a8 100644
--- a/usr.bin/dig/lib/isc/unix/socket.c
+++ b/usr.bin/dig/lib/isc/unix/socket.c
@@ -834,9 +834,14 @@ doio_recv(isc_socket_t *sock, isc_socketevent_t *dev) {
 	struct msghdr msghdr;
 	isc_buffer_t *buffer;
 	int recv_errno;
-	char cmsgbuf[RECVCMSGBUFLEN] = {0};
+	union {
+		struct msghdr msghdr;
+		char m[RECVCMSGBUFLEN];
+	} cmsgbuf;
+	
+	memset(&cmsgbuf, 0, sizeof(cmsgbuf));
 
-	build_msghdr_recv(sock, cmsgbuf, dev, &msghdr, iov, &read_count);
+	build_msghdr_recv(sock, cmsgbuf.m, dev, &msghdr, iov, &read_count);
 
 	cc = recvmsg(sock->fd, &msghdr, 0);
 	recv_errno = errno;
@@ -989,9 +994,14 @@ doio_send(isc_socket_t *sock, isc_socketevent_t *dev) {
 	char addrbuf[ISC_SOCKADDR_FORMATSIZE];
 	int attempts = 0;
 	int send_errno;
-	char cmsgbuf[SENDCMSGBUFLEN] = {0};
-
-	build_msghdr_send(sock, cmsgbuf, dev, &msghdr, iov, &write_count);
+	union {
+		struct msghdr msghdr;
+		char m[SENDCMSGBUFLEN];
+	} cmsgbuf;
+	
+	memset(&cmsgbuf, 0, sizeof(cmsgbuf));
+
+	build_msghdr_send(sock, cmsgbuf.m, dev, &msghdr, iov, &write_count);
 
  resend:
 	cc = sendmsg(sock->fd, &msghdr, 0);