Index: amd64/linux32/linux.h
===================================================================
--- amd64/linux32/linux.h	(revision 245225)
+++ amd64/linux32/linux.h	(working copy)
@@ -725,6 +725,13 @@
 #define	LINUX_IP_ADD_MEMBERSHIP		35
 #define	LINUX_IP_DROP_MEMBERSHIP	36
 
+#define	LINUX_TCP_NODELAY	1
+#define	LINUX_TCP_MAXSEG	2
+#define	LINUX_TCP_KEEPIDLE	4
+#define	LINUX_TCP_KEEPINTVL	5
+#define	LINUX_TCP_KEEPCNT	6
+#define	LINUX_TCP_MD5SIG	14
+
 struct l_sockaddr {
 	l_ushort	sa_family;
 	char		sa_data[14];
Index: compat/linux/linux_socket.c
===================================================================
--- compat/linux/linux_socket.c	(revision 245225)
+++ compat/linux/linux_socket.c	(working copy)
@@ -56,6 +56,7 @@
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
 #include <netinet/ip.h>
+#include <netinet/tcp.h>
 #ifdef INET6
 #include <netinet/ip6.h>
 #include <netinet6/ip6_var.h>
@@ -326,6 +327,27 @@
 }
 
 static int
+linux_to_bsd_tcp_sockopt(int opt)
+{
+
+	switch (opt) {
+	case LINUX_TCP_NODELAY:
+		return (TCP_NODELAY);
+	case LINUX_TCP_MAXSEG:
+		return (TCP_MAXSEG);
+	case LINUX_TCP_KEEPIDLE:
+		return (TCP_KEEPIDLE);
+	case LINUX_TCP_KEEPINTVL:
+		return (TCP_KEEPINTVL);
+	case LINUX_TCP_KEEPCNT:
+		return (TCP_KEEPCNT);
+	case LINUX_TCP_MD5SIG:
+		return (TCP_MD5SIG);
+	}
+	return (-1);
+}
+
+static int
 linux_to_bsd_msg_flags(int flags)
 {
 	int ret_flags = 0;
@@ -1496,8 +1518,7 @@
 		name = linux_to_bsd_ip_sockopt(args->optname);
 		break;
 	case IPPROTO_TCP:
-		/* Linux TCP option values match BSD's */
-		name = args->optname;
+		name = linux_to_bsd_tcp_sockopt(args->optname);
 		break;
 	default:
 		name = -1;
Index: i386/linux/linux.h
===================================================================
--- i386/linux/linux.h	(revision 245225)
+++ i386/linux/linux.h	(working copy)
@@ -701,6 +701,13 @@
 #define	LINUX_IP_ADD_MEMBERSHIP		35
 #define	LINUX_IP_DROP_MEMBERSHIP	36
 
+#define	LINUX_TCP_NODELAY	1
+#define	LINUX_TCP_MAXSEG	2
+#define	LINUX_TCP_KEEPIDLE	4
+#define	LINUX_TCP_KEEPINTVL	5
+#define	LINUX_TCP_KEEPCNT	6
+#define	LINUX_TCP_MD5SIG	14
+
 struct l_sockaddr {
 	l_ushort	sa_family;
 	char		sa_data[14];