Import a (stripped) snapshot of OpenBSD's nc(1) an excellent

reimplementation of the famous tool that can do arbitrary TCP
and UDP connections and listens.

This gaves sysadm the same tool the crackers have, so that
they may learn what the network is about and protect it better.
For developers, this is an invaluable debugging tool, and a
good build block of scripts.

Discussed on:	freebsd-hackers@

1 files changed, 56 insertions, 0 deletions

diff --git a/contrib/netcat/atomicio.c b/contrib/netcat/atomicio.c
new file mode 100644
index 0000000..9e73290
--- /dev/null
+++ b/contrib/netcat/atomicio.c
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 1995,1999 Theo de Raadt.  All rights reserved.
+ * 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 <sys/types.h>
+#include <sys/uio.h>
+
+#include <errno.h>
+#include <unistd.h>
+
+ssize_t atomicio(ssize_t (*f)(int, void *, size_t), int fd, void *_s, size_t n);
+
+/*
+ * ensure all of data on socket comes through. f==read || f==write
+ */
+ssize_t
+atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
+{
+	char *s = _s;
+	ssize_t res, pos = 0;
+
+	while (n > pos) {
+		res = (f) (fd, s + pos, n - pos);
+		switch (res) {
+		case -1:
+			if (errno == EINTR || errno == EAGAIN)
+				continue;
+		case 0:
+			return (res);
+		default:
+			pos += res;
+		}
+	}
+	return (pos);
+}