1 files changed, 65 insertions, 0 deletions
diff --git a/src/util/sane_connect.c b/src/util/sane_connect.c
new file mode 100644
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--- /dev/null
+++ b/src/util/sane_connect.c
@@ -0,0 +1,65 @@
+/*++
+/* NAME
+/*	sane_connect 3
+/* SUMMARY
+/*	sanitize connect() results
+/* SYNOPSIS
+/*	#include <sane_connect.h>
+/*
+/*	int	sane_connect(sock, buf, len)
+/*	int	sock;
+/*	struct sockaddr	*buf;
+/*	SOCKADDR_SIZE *len;
+/* DESCRIPTION
+/*	sane_connect() implements the connect(2) socket call, and maps
+/*	known harmless error results to EAGAIN.
+/* BUGS
+/*	Bizarre systems may have other harmless error results. Such
+/*	systems encourage programmers to ignore error results, and
+/*	penalize programmers who code defensively.
+/* 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 <sys/socket.h>
+#include <errno.h>
+
+/* Utility library. */
+
+#include "msg.h"
+#include "sane_connect.h"
+
+/* sane_connect - sanitize connect() results */
+
+int     sane_connect(int sock, struct sockaddr *sa, SOCKADDR_SIZE len)
+{
+
+    /*
+     * XXX Solaris select() produces false read events, so that read() blocks
+     * forever on a blocking socket, and fails with EAGAIN on a non-blocking
+     * socket. Turning on keepalives will fix a blocking socket provided that
+     * the kernel's keepalive timer expires before the Postfix watchdog
+     * timer.
+     * 
+     * XXX Work around NAT induced damage by sending a keepalive before an idle
+     * connection is expired. This requires that the kernel keepalive timer
+     * is set to a short time, like 100s.
+     */
+    if (sa->sa_family == AF_INET) {
+	int     on = 1;
+
+	(void) setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
+			  (void *) &on, sizeof(on));
+    }
+    return (connect(sock, sa, len));
+}