11.1/ipfilter-local-output-tcp-checksum.diff

Make fastroute for local output TCP packets work.

diff -ru --exclude-from freebsd-src-diff-exclude-names /usr/src/sys/contrib/ipfilter/netinet/fil.c freebsd-11.1/sys/contrib/ipfilter/netinet/fil.c
--- /usr/src/sys/contrib/ipfilter/netinet/fil.c	2017-07-21 07:41:56.000000000 +0800
+++ freebsd-11.1/sys/contrib/ipfilter/netinet/fil.c	2020-01-26 00:06:12.922137000 +0800
@@ -3242,6 +3242,25 @@
 		} else if ((fdp != NULL) && (fdp->fd_ptr != NULL) &&
 			   (fdp->fd_ptr != (struct ifnet *)-1)) {
 			/* this is for to rules: */
+			if(out && fin->fin_p == IPPROTO_TCP) {
+				uint16_t *sum = &((tcphdr_t *)fin->fin_dp)->th_sum;
+#ifdef __FreeBSD_kernel__
+				/* Local local output TCP packets in kFreeBSD
+				 * will have a pseudo header checksum already
+				 * calculated; the final checksum must be
+				 * calculated again here.
+				 */
+				if(*sum == in_pseudo(fin->fin_ip->ip_src.s_addr,
+				  fin->fin_ip->ip_dst.s_addr,
+				  htons(IPPROTO_TCP + ntohs(fin->fin_ip->ip_len) - fin->fin_hlen))) {
+					*sum = 0;
+				}
+#endif
+				if(!*sum) {
+					*sum = fr_cksum(fin, fin->fin_ip,
+						IPPROTO_TCP, fin->fin_dp);
+				}
+			}
 			ipf_fastroute(fin->fin_m, mp, fin, fdp);
 			m = *mp = NULL;
 		}
diff -ru --exclude-from freebsd-src-diff-exclude-names /usr/src/sys/contrib/ipfilter/netinet/ip_compat.h freebsd-11.1/sys/contrib/ipfilter/netinet/ip_compat.h
--- /usr/src/sys/contrib/ipfilter/netinet/ip_compat.h	2017-07-21 07:41:56.000000000 +0800
+++ freebsd-11.1/sys/contrib/ipfilter/netinet/ip_compat.h	2020-01-26 00:06:12.925665000 +0800
@@ -117,6 +117,10 @@
 /* ----------------------------------------------------------------------- */
 /*                                F R E E B S D                            */
 /* ----------------------------------------------------------------------- */
+#if defined __FreeBSD__ && !defined __FreeBSD_kernel__
+#define __FreeBSD_kernel__ 1
+#endif
+//#ifdef __FreeBSD_kernel__
 # define HAS_SYS_MD5_H	1
 # if defined(_KERNEL)
 #   include "opt_bpf.h"
@@ -244,6 +248,7 @@
 typedef	int		minor_t;
 typedef	u_int32_t	u_32_t;
 # define	U_32_T	1
+//#endif	/* __FreeBSD_kernel__ */
 
 
 /* ----------------------------------------------------------------------- */