From 440753e8b08d48cb5620c5463c9602f13db7c035 Mon Sep 17 00:00:00 2001
From: Baorong Liu <baorliu@cisco.com>
Date: Mon, 10 Jul 2023 10:14:11 -0700
Subject: [PATCH] [staticroutebfd]  fix ipv6 letter case issue (#15765)

*use lower case for IPv6 address as internal key and bfd session key. fixes #15764

Why I did it
*staticroutebfd uses the IPv6 address string as a key to create bfd session and cache the bfd sessions using it as a key.
When the IPv6 address string has uppercase letter in the static route nexthop list, the string with uppercase letter key is stored in the cache, but the BFD STATE_DB uses lowercase for IPv6 address, so when the staticroutebfd get the bfd state event, it cannot find the bfd session in its local cache because of the letter case.
---
 src/sonic-bgpcfgd/staticroutebfd/main.py      |  8 ++
 src/sonic-bgpcfgd/tests/test_static_rt_bfd.py | 76 +++++++++++++++++++
 2 files changed, 84 insertions(+)

diff --git a/src/sonic-bgpcfgd/staticroutebfd/main.py b/src/sonic-bgpcfgd/staticroutebfd/main.py
index 2d7006420eb9..89f10f2dca5a 100644
--- a/src/sonic-bgpcfgd/staticroutebfd/main.py
+++ b/src/sonic-bgpcfgd/staticroutebfd/main.py
@@ -66,6 +66,9 @@ def static_route_split_key(key):
     :param key: key to split
     :return: valid, vrf name extracted from the key, ip prefix extracted from the key
     """
+    if key is None or len(key) == 0:
+        return False, "", ""
+
     l = tuple(key.split('|'))
 
     if len(l) == 1:
@@ -376,6 +379,11 @@ def static_route_set_handler(self, key, data):
             log_err("invalid ip prefix for static route: '%s'"%(key))
             return True
 
+        #use lower case if there is letter in IPv6 address string
+        if 'nexthop' in data:
+            nh = data['nexthop']
+            data['nexthop'] = nh.lower()
+
         arg_list  = lambda v: [x.strip() for x in v.split(',')] if len(v.strip()) != 0 else None
         bfd_field = arg_list(data['bfd']) if 'bfd' in data else ["false"]
 
diff --git a/src/sonic-bgpcfgd/tests/test_static_rt_bfd.py b/src/sonic-bgpcfgd/tests/test_static_rt_bfd.py
index 24f88bade1c6..107b994c6bc8 100644
--- a/src/sonic-bgpcfgd/tests/test_static_rt_bfd.py
+++ b/src/sonic-bgpcfgd/tests/test_static_rt_bfd.py
@@ -94,6 +94,82 @@ def intf_setup(dut):
         {},
         {}
     )
+    set_del_test(dut, "intf",
+        "SET",
+        ("if1|2603:10E2:400:1::1/64",{}
+        ),
+        {},
+        {}
+    )
+    set_del_test(dut, "intf",
+        "SET",
+        ("if2|2603:10E2:400:2::1/64",{}
+        ),
+        {},
+        {}
+    )
+    set_del_test(dut, "intf",
+        "SET",
+        ("if3|2603:10E2:400:3::1/64",{}
+        ),
+        {},
+        {}
+    )    
+
+def test_set_del_ipv6():
+    dut = constructor()
+    intf_setup(dut)
+
+    set_del_test(dut, "srt",
+        "SET",
+        ("2603:10e2:400::4/128", {
+            "bfd": "true",
+            "ifname": "if1, if2, if3",
+            "nexthop": "2603:10E2:400:1::2,2603:10E2:400:2::2,2603:10e2:400:3::2"
+        }),
+        { 
+            "set_default:default:2603:10e2:400:1::2" : {'multihop': 'true', 'rx_interval': '50', 'tx_interval': '50', 'multiplier': '3', 'local_addr': '2603:10E2:400:1::1'},
+            "set_default:default:2603:10e2:400:2::2" : {'multihop': 'true', 'rx_interval': '50', 'tx_interval': '50', 'multiplier': '3', 'local_addr': '2603:10E2:400:2::1'},
+            "set_default:default:2603:10e2:400:3::2" : {'multihop': 'true', 'rx_interval': '50', 'tx_interval': '50', 'multiplier': '3', 'local_addr': '2603:10E2:400:3::1'}
+        },
+        {}
+    )
+
+    set_del_test(dut, "bfd",
+        "SET",
+        ("2603:10e2:400:1::2", {
+            "state": "Up"
+        }),
+        {},
+        {'set_default:2603:10e2:400::4/128': {'nexthop': '2603:10e2:400:1::2', 'ifname': 'if1', 'nexthop-vrf': 'default', 'expiry': 'false'}}
+    )
+    set_del_test(dut, "bfd",
+        "SET",
+        ("2603:10e2:400:2::2", {
+            "state": "Up"
+        }),
+        {},
+        {'set_default:2603:10e2:400::4/128': {'nexthop': '2603:10e2:400:1::2,2603:10e2:400:2::2', 'ifname': 'if1,if2', 'nexthop-vrf': 'default,default', 'expiry': 'false'}}
+    )
+    set_del_test(dut, "bfd",
+        "SET",
+        ("2603:10e2:400:3::2", {
+            "state": "Up"
+        }),
+        {},
+        {'set_default:2603:10e2:400::4/128': {'nexthop': '2603:10e2:400:1::2,2603:10e2:400:2::2,2603:10e2:400:3::2', 'ifname': 'if1,if2,if3', 'nexthop-vrf': 'default,default,default', 'expiry': 'false'}}
+    )
+
+    set_del_test(dut, "srt",
+        "DEL",
+        ("2603:10e2:400::4/128", { }),
+        {
+            "del_default:default:2603:10e2:400:1::2" : {},
+            "del_default:default:2603:10e2:400:2::2" : {},
+            "del_default:default:2603:10e2:400:3::2" : {}
+        },
+        {'del_default:2603:10e2:400::4/128': { }}
+    )
 
 @patch('staticroutebfd.main.log_err')
 def test_invalid_key(mocked_log_err):