with the issue. */
#include <features.h>
+#include <sys/types.h>
#define CRYPT_H
#define NO_IP_VAR_H
#define SIG_IGN_WORKS
-/* When using the DKIM, setting HAVE_LINUX_SENDFILE can increase
+/* When using DKIM, setting OS_SENDFILE can increase
performance on outgoing mail a bit. Note: With older glibc versions
this setting will conflict with the _FILE_OFFSET_BITS=64 setting
-defined as part of the Linux CFLAGS. */
+defined as part of the Linux CFLAGS. As of 2017 those are declared
+to be too old to build by default. */
-/* #define HAVE_LINUX_SENDFILE */
+#define OS_SENDFILE
+extern ssize_t os_sendfile(int, int, off_t *, size_t);
#define F_FREESP O_TRUNC
typedef struct flock flock_t;
#define OS_STRSIGNAL
#if defined(__linux__) || defined(__FreeBSD_kernel__) || defined(__NetBSD_kernel__)
-#define SIOCGIFCONF_GIVES_ADDR
-#define HAVE_SYS_MOUNT_H
+# define SIOCGIFCONF_GIVES_ADDR
+# define HAVE_SYS_MOUNT_H
#endif
#if defined(__linux__)
# define EXIM_HAVE_OPENAT
#endif
+/* TCP Fast Open support */
+
+#include <netinet/tcp.h> /* for TCP_FASTOPEN */
+#include <sys/socket.h> /* for MSG_FASTOPEN */
#if defined(TCP_FASTOPEN) && !defined(MSG_FASTOPEN)
# define MSG_FASTOPEN 0x20000000
#endif