From: Andreas Schultz <andreas.schultz@travelping.com>
Date: Tue, 12 May 2020 12:41:16 +0000 (+0200)
Subject: ip: fix IPv6 mask to prefix length conversion
X-Git-Tag: v21.01-rc0~321
X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=3b519b38b0df186f424d2ff2f5e8015408d67c53;p=vpp.git

ip: fix IPv6 mask to prefix length conversion

make sure we don't pass a 0 (zero) to log2.

Type: fix

Signed-off-by: Andreas Schultz <andreas.schultz@travelping.com>
Change-Id: Ib3386ad4686835d3836f48294cee4058e897847a
---

diff --git a/src/vat/ip_types.c b/src/vat/ip_types.c
index cd08c5417ad..5041c129245 100644
--- a/src/vat/ip_types.c
+++ b/src/vat/ip_types.c
@@ -511,16 +511,11 @@ ip6_prefix_max_address_host_order (ip6_address_t * ip, u8 plen,
 u32
 ip6_mask_to_preflen (ip6_address_t * mask)
 {
-  u8 first1, first0;
-  if (mask->as_u64[0] == 0 && mask->as_u64[1] == 0)
-    return 0;
-  first1 = log2_first_set (clib_net_to_host_u64 (mask->as_u64[1]));
-  first0 = log2_first_set (clib_net_to_host_u64 (mask->as_u64[0]));
-
-  if (first1 != 0)
-    return 128 - first1;
-  else
-    return 64 - first0;
+  if (mask->as_u64[1] != 0)
+    return 128 - log2_first_set (clib_net_to_host_u64 (mask->as_u64[1]));
+  if (mask->as_u64[0] != 0)
+    return 64 - log2_first_set (clib_net_to_host_u64 (mask->as_u64[0]));
+  return 0;
 }
 
 /*
diff --git a/src/vnet/ip/ip_types.c b/src/vnet/ip/ip_types.c
index cd08c5417ad..5041c129245 100644
--- a/src/vnet/ip/ip_types.c
+++ b/src/vnet/ip/ip_types.c
@@ -511,16 +511,11 @@ ip6_prefix_max_address_host_order (ip6_address_t * ip, u8 plen,
 u32
 ip6_mask_to_preflen (ip6_address_t * mask)
 {
-  u8 first1, first0;
-  if (mask->as_u64[0] == 0 && mask->as_u64[1] == 0)
-    return 0;
-  first1 = log2_first_set (clib_net_to_host_u64 (mask->as_u64[1]));
-  first0 = log2_first_set (clib_net_to_host_u64 (mask->as_u64[0]));
-
-  if (first1 != 0)
-    return 128 - first1;
-  else
-    return 64 - first0;
+  if (mask->as_u64[1] != 0)
+    return 128 - log2_first_set (clib_net_to_host_u64 (mask->as_u64[1]));
+  if (mask->as_u64[0] != 0)
+    return 64 - log2_first_set (clib_net_to_host_u64 (mask->as_u64[0]));
+  return 0;
 }
 
 /*