1 files changed, 89 insertions, 0 deletions
diff --git a/src/util/write_buf.c b/src/util/write_buf.c
new file mode 100644
index 0000000..968a468
--- /dev/null
+++ b/src/util/write_buf.c
@@ -0,0 +1,89 @@
+/*++
+/* NAME
+/*	write_buf 3
+/* SUMMARY
+/*	write buffer or bust
+/* SYNOPSIS
+/*	#include <iostuff.h>
+/*
+/*	ssize_t	write_buf(fd, buf, len, timeout)
+/*	int	fd;
+/*	const char *buf;
+/*	ssize_t	len;
+/*	int	timeout;
+/* DESCRIPTION
+/*	write_buf() writes a buffer to the named stream in as many
+/*	fragments as needed, and returns the number of bytes written,
+/*	which is always the number requested or an error indication.
+/*
+/*	Arguments:
+/* .IP fd
+/*	File descriptor in the range 0..FD_SETSIZE.
+/* .IP buf
+/*	Address of data to be written.
+/* .IP len
+/*	Amount of data to be written.
+/* .IP timeout
+/*	Bounds the time in seconds to wait until \fIfd\fD becomes writable.
+/*	A value <= 0 means do not wait; this is useful only when \fIfd\fR
+/*	uses blocking I/O.
+/* DIAGNOSTICS
+/*	write_buf() returns -1 in case of trouble. The global \fIerrno\fR
+/*	variable reflects the nature of the problem.
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <unistd.h>
+#include <errno.h>
+#include <time.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <iostuff.h>
+
+/* write_buf - write buffer or bust */
+
+ssize_t write_buf(int fd, const char *buf, ssize_t len, int timeout)
+{
+    const char *start = buf;
+    ssize_t count;
+    time_t  expire;
+    int     time_left = timeout;
+
+    if (time_left > 0)
+	expire = time((time_t *) 0) + time_left;
+
+    while (len > 0) {
+	if (time_left > 0 && write_wait(fd, time_left) < 0)
+	    return (-1);
+	if ((count = write(fd, buf, len)) < 0) {
+	    if ((errno == EAGAIN && time_left > 0) || errno == EINTR)
+		 /* void */ ;
+	    else
+		return (-1);
+	} else {
+	    buf += count;
+	    len -= count;
+	}
+	if (len > 0 && time_left > 0) {
+	    time_left = expire - time((time_t *) 0);
+	    if (time_left <= 0) {
+		errno = ETIMEDOUT;
+		return (-1);
+	    }
+	}
+    }
+    return (buf - start);
+}