git: 4a7b49a0da00 - main - ipfilter: Save time and cycles swapping bucket table sizes

[Cy Schubert]

The branch main has been updated by cy:

URL: https://cgit.FreeBSD.org/src/commit/?id=4a7b49a0da00d7822656e2adefafac885bbfd310

commit 4a7b49a0da00d7822656e2adefafac885bbfd310
Author:     Cy Schubert <cy at FreeBSD.org>
AuthorDate: 2021-09-28 03:04:18 +0000
Commit:     Cy Schubert <cy at FreeBSD.org>
CommitDate: 2021-09-30 00:44:02 +0000

    ipfilter: Save time and cycles swapping bucket table sizes
    
    NAT hash tables are inverted for inbound vs outbound. Rather than spend
    the time and cycles swapping them, let's simply calculate the bucket
    lengths inversely.
    
    MFC after:      1 week
---
 sys/contrib/ipfilter/netinet/ip_nat.c  | 13 +++++--------
 sys/contrib/ipfilter/netinet/ip_nat6.c | 29 +++++++++++++++++------------
 2 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/sys/contrib/ipfilter/netinet/ip_nat.c b/sys/contrib/ipfilter/netinet/ip_nat.c
index 0475a4386079..054f92a93401 100644
--- a/sys/contrib/ipfilter/netinet/ip_nat.c
+++ b/sys/contrib/ipfilter/netinet/ip_nat.c
@@ -3521,15 +3521,12 @@ ipf_nat_hashtab_add(softc, softn, nat)
 	u_int hv0;
 	u_int hv1;
 
-	hv0 = nat->nat_hv[0] % softn->ipf_nat_table_sz;
-	hv1 = nat->nat_hv[1] % softn->ipf_nat_table_sz;
-
 	if (nat->nat_dir == NAT_INBOUND || nat->nat_dir == NAT_DIVERTIN) {
-		u_int swap;
-
-		swap = hv0;
-		hv0 = hv1;
-		hv1 = swap;
+		hv1 = nat->nat_hv[0] % softn->ipf_nat_table_sz;
+		hv0 = nat->nat_hv[1] % softn->ipf_nat_table_sz;
+	} else {
+		hv0 = nat->nat_hv[0] % softn->ipf_nat_table_sz;
+		hv1 = nat->nat_hv[1] % softn->ipf_nat_table_sz;
 	}
 
 	if (softn->ipf_nat_stats.ns_side[0].ns_bucketlen[hv0] >=
diff --git a/sys/contrib/ipfilter/netinet/ip_nat6.c b/sys/contrib/ipfilter/netinet/ip_nat6.c
index baa3c302504a..c03048ee12ac 100644
--- a/sys/contrib/ipfilter/netinet/ip_nat6.c
+++ b/sys/contrib/ipfilter/netinet/ip_nat6.c
@@ -2160,19 +2160,24 @@ ipf_nat6_tabmove(softn, nat)
 	/*
 	 * Add into the NAT table in the new position
 	 */
-	hv0 = NAT_HASH_FN6(&nat->nat_osrc6, nat->nat_osport, 0xffffffff);
-	hv0 = NAT_HASH_FN6(&nat->nat_odst6, hv0 + nat->nat_odport,
-			   softn->ipf_nat_table_sz);
-	hv1 = NAT_HASH_FN6(&nat->nat_nsrc6, nat->nat_nsport, 0xffffffff);
-	hv1 = NAT_HASH_FN6(&nat->nat_ndst6, hv1 + nat->nat_ndport,
-			   softn->ipf_nat_table_sz);
-
 	if (nat->nat_dir == NAT_INBOUND || nat->nat_dir == NAT_DIVERTIN) {
-		u_int swap;
-
-		swap = hv0;
-		hv0 = hv1;
-		hv1 = swap;
+		hv1 = NAT_HASH_FN6(&nat->nat_osrc6,
+			nat->nat_osport, 0xffffffff);
+		hv1 = NAT_HASH_FN6(&nat->nat_odst6, hv1 + nat->nat_odport,
+			softn->ipf_nat_table_sz);
+		hv0 = NAT_HASH_FN6(&nat->nat_nsrc6,
+			nat->nat_nsport, 0xffffffff);
+		hv0 = NAT_HASH_FN6(&nat->nat_ndst6, hv0 + nat->nat_ndport,
+			softn->ipf_nat_table_sz);
+	} else {
+		hv0 = NAT_HASH_FN6(&nat->nat_osrc6,
+			nat->nat_osport, 0xffffffff);
+		hv0 = NAT_HASH_FN6(&nat->nat_odst6, hv0 + nat->nat_odport,
+			softn->ipf_nat_table_sz);
+		hv1 = NAT_HASH_FN6(&nat->nat_nsrc6,
+			nat->nat_nsport, 0xffffffff);
+		hv1 = NAT_HASH_FN6(&nat->nat_ndst6, hv1 + nat->nat_ndport,
+			softn->ipf_nat_table_sz);
 	}
 
 	/* TRACE nat_osrc6, nat_osport, nat_odst6, nat_odport, hv0 */