patch 'fib6: fix adding default route as first route' has been queued to stable release 22.11.4

[Xueming Li]

Hi,

FYI, your patch has been queued to stable release 22.11.4

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/15/23. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://git.dpdk.org/dpdk-stable/log/?h=22.11-staging

This queued commit can be viewed at:
https://git.dpdk.org/dpdk-stable/commit/?h=22.11-staging&id=c6b2c85ca46d331f2eb448ab58b212d233726086

Thanks.

Xueming Li <xuemingl at nvidia.com>

---
>From c6b2c85ca46d331f2eb448ab58b212d233726086 Mon Sep 17 00:00:00 2001
From: Vladimir Medvedkin <vladimir.medvedkin at intel.com>
Date: Mon, 2 Oct 2023 15:12:01 +0000
Subject: [PATCH] fib6: fix adding default route as first route
Cc: Xueming Li <xuemingl at nvidia.com>

[ upstream commit fd66617c5774a2869cbb69f86494d1b4803890fc ]

Currently when adding default route as first route
it is not added and no error is reported.
When we enter the loop over an address range in
the general case we will eventually reach the check
for when the range has ended, and exit the loop.
However when adding default route as first route,
since address range covered begins and ends at zero
this also triggers loop exit without writing to the table.

Fixed by adding check for default route,
i.e. both ledge and redge are equal to 0::0.

Bugzilla ID: 1272
Fixes: c3e12e0f0354 ("fib: add dataplane algorithm for IPv6")

Signed-off-by: Vladimir Medvedkin <vladimir.medvedkin at intel.com>
---
 lib/fib/trie.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/lib/fib/trie.c b/lib/fib/trie.c
index 3e780afdaf..09470e7287 100644
--- a/lib/fib/trie.c
+++ b/lib/fib/trie.c
@@ -451,6 +451,14 @@ get_nxt_net(uint8_t *ip, uint8_t depth)
 	}
 }

+static int
+v6_addr_is_zero(const uint8_t ip[RTE_FIB6_IPV6_ADDR_SIZE])
+{
+	uint8_t ip_addr[RTE_FIB6_IPV6_ADDR_SIZE] = {0};
+
+	return rte_rib6_is_equal(ip, ip_addr);
+}
+
 static int
 modify_dp(struct rte_trie_tbl *dp, struct rte_rib6 *rib,
 	const uint8_t ip[RTE_FIB6_IPV6_ADDR_SIZE],
@@ -484,11 +492,19 @@ modify_dp(struct rte_trie_tbl *dp, struct rte_rib6 *rib,
 				return ret;
 			get_nxt_net(redge, tmp_depth);
 			rte_rib6_copy_addr(ledge, redge);
+			/*
+			 * we got to the end of address space
+			 * and wrapped around
+			 */
+			if (v6_addr_is_zero(ledge))
+				break;
 		} else {
 			rte_rib6_copy_addr(redge, ip);
 			get_nxt_net(redge, depth);
-			if (rte_rib6_is_equal(ledge, redge))
+			if (rte_rib6_is_equal(ledge, redge) &&
+					!v6_addr_is_zero(ledge))
 				break;
+
 			ret = install_to_dp(dp, ledge, redge,
 				next_hop);
 			if (ret != 0)
--
2.25.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2023-10-22 22:17:38.157739900 +0800
+++ 0104-fib6-fix-adding-default-route-as-first-route.patch	2023-10-22 22:17:34.376723700 +0800
@@ -1 +1 @@
-From fd66617c5774a2869cbb69f86494d1b4803890fc Mon Sep 17 00:00:00 2001
+From c6b2c85ca46d331f2eb448ab58b212d233726086 Mon Sep 17 00:00:00 2001
@@ -4,0 +5,3 @@
+Cc: Xueming Li <xuemingl at nvidia.com>
+
+[ upstream commit fd66617c5774a2869cbb69f86494d1b4803890fc ]
@@ -20 +22,0 @@
-Cc: stable at dpdk.org