Initial commit

1 files changed, 85 insertions, 0 deletions

diff --git a/unix/sun/notify_read.c b/unix/sun/notify_read.c
new file mode 100644
index 00000000..b02913c9
--- /dev/null
+++ b/unix/sun/notify_read.c
@@ -0,0 +1,85 @@
+/* Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+ */
+
+#include <syscall.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <stdio.h>
+
+static	int (*u_fcn)();		/* user functions to process read	*/
+static	int u_fd;		/* fd to be monitored			*/
+
+/* NOTIFY_READ -- This is a customized version of the SunView 3.2 notify_read
+ * primitive, the notifier's version of the UNIX read() system call (when
+ * the notifier is used, read() is a high level function, not a system call).
+ * The function of this special version of notify_read is to intercept kernel
+ * read calls made by the notifier for the purposes of monitoring, and
+ * possibly filtering, low level input from a file descriptor.
+ */
+notify_read (fd, buf, maxch)
+int	fd;
+char	*buf;
+int	maxch;
+{
+	register int n;
+
+	/* This is a bit of a kludge, but lacking the shelltool source it
+	 * was difficult to do better.  The 18 is the size of the tty packet
+	 * echoed by the driver when a character is typed; this is not part
+	 * of the normal output stream so we exclude these events.  The buf+1
+	 * business is to hide the packet mode nature of the stream from the
+	 * gtermio code; the first byte of each packet indicates the packet
+	 * type.  These details could change in a future Sun release in which
+	 * case this code would have to be modified.
+	 */
+	if (u_fcn && fd == u_fd && maxch != 18) {
+	    n = syscall (SYS_read, fd, buf, maxch);
+	    if (n > 0 && *buf == TIOCPKT_DATA)
+		return ((*u_fcn)(buf+1, n-1, maxch-1) + 1);
+	    else
+		return (n);
+	} else
+	    return (syscall (SYS_read, fd, buf, maxch));
+}
+
+
+/* READV -- This is a customized version of the readv system call, used in
+ * the Release 3.4 version of ttysw to read from the pty.  Usage is (appears
+ * to be) identical to the old notify_read, except that the TIOCPKT byte is
+ * returned separately from the data.
+ */
+readv (fd, iov, iovcnt)
+register int	fd;
+register struct	iovec *iov;
+int	iovcnt;
+{
+	register int n;
+
+	if (u_fcn && fd == u_fd && iovcnt == 2 && iov[0].iov_len == 1) {
+	    n = syscall (SYS_readv, fd, iov, iovcnt);
+	    if (n > 0 && *(iov[0].iov_base) == TIOCPKT_DATA)
+		return ((*u_fcn)(iov[1].iov_base, n-1, iov[1].iov_len) + 1);
+	    else
+		return (n);
+	} else
+	    return (syscall (SYS_readv, fd, iov, iovcnt));
+}
+
+
+/* NOTIFY_READ_POST_MONITOR_FCN -- Post a user data monitor/filter function
+ * to process the input on the specified file descriptor.  Only one file
+ * descriptor can be monitored at present.
+ */
+notify_read_post_monitor_fcn (fd, fcn)
+int	fd;
+int	(*fcn)();
+{
+	if (u_fcn && !fcn)
+	    return (-1);
+	else {
+	    u_fcn = fcn;
+	    u_fd  = fd;
+	    return (0);
+	}
+}