From 0870cf5f699aa79e42800c8a8900a3dc3977b934 Mon Sep 17 00:00:00 2001
From: Nazarii Hnydyn <nazariig@nvidia.com>
Date: Mon, 4 Apr 2022 16:22:35 +0300
Subject: [PATCH] [mirrororch]: Implement HW resources availability validation
 for SPAN/ERSPAN (#2187)

- What I did
Added a validation to prevent mirror session configuration if there is no available HW resources

- Why I did it
To prevent system from unexpected reboots
To add some debuggability information to the system journal

- How I verified it
Configure mirror sessions

Signed-off-by: Nazarii Hnydyn <nazariig@nvidia.com>
---
 orchagent/mirrororch.cpp | 35 ++++++++++++++++++++++++++++++-----
 orchagent/mirrororch.h   |  2 ++
 2 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/orchagent/mirrororch.cpp b/orchagent/mirrororch.cpp
index 6568c63d37c7..fca324e5fb49 100644
--- a/orchagent/mirrororch.cpp
+++ b/orchagent/mirrororch.cpp
@@ -352,6 +352,27 @@ bool MirrorOrch::validateSrcPortList(const string& srcPortList)
     return true;
 }
 
+bool MirrorOrch::isHwResourcesAvailable()
+{
+    uint64_t availCount = 0;
+
+    sai_status_t status = sai_object_type_get_availability(
+        gSwitchId, SAI_OBJECT_TYPE_MIRROR_SESSION, 0, nullptr, &availCount
+    );
+    if (status != SAI_STATUS_SUCCESS)
+    {
+        if (status == SAI_STATUS_NOT_SUPPORTED)
+        {
+            SWSS_LOG_WARN("Mirror session resource availability monitoring is not supported. Skipping ...");
+            return true;
+        }
+
+        return parseHandleSaiStatusFailure(handleSaiGetStatus(SAI_API_MIRROR, status));
+    }
+
+    return availCount > 0;
+}
+
 task_process_status MirrorOrch::createEntry(const string& key, const vector<FieldValueTuple>& data)
 {
     SWSS_LOG_ENTER();
@@ -359,8 +380,7 @@ task_process_status MirrorOrch::createEntry(const string& key, const vector<Fiel
     auto session = m_syncdMirrors.find(key);
     if (session != m_syncdMirrors.end())
     {
-        SWSS_LOG_NOTICE("Failed to create session, session %s already exists",
-                key.c_str());
+        SWSS_LOG_NOTICE("Failed to create session %s: object already exists", key.c_str());
         return task_process_status::task_duplicated;
     }
 
@@ -471,10 +491,13 @@ task_process_status MirrorOrch::createEntry(const string& key, const vector<Fiel
         }
     }
 
-    m_syncdMirrors.emplace(key, entry);
-
-    SWSS_LOG_NOTICE("Created mirror session %s", key.c_str());
+    if (!isHwResourcesAvailable())
+    {
+        SWSS_LOG_ERROR("Failed to create session %s: HW resources are not available", key.c_str());
+        return task_process_status::task_failed;
+    }
 
+    m_syncdMirrors.emplace(key, entry);
     setSessionState(key, entry);
 
     if (entry.type == MIRROR_SESSION_SPAN && !entry.dst_port.empty())
@@ -488,6 +511,8 @@ task_process_status MirrorOrch::createEntry(const string& key, const vector<Fiel
         m_routeOrch->attach(this, entry.dstIp);
     }
 
+    SWSS_LOG_NOTICE("Created mirror session %s", key.c_str());
+
     return task_process_status::task_success;
 }
 
diff --git a/orchagent/mirrororch.h b/orchagent/mirrororch.h
index b31d58bff3d6..d498a7ef6c92 100644
--- a/orchagent/mirrororch.h
+++ b/orchagent/mirrororch.h
@@ -104,6 +104,8 @@ class MirrorOrch : public Orch, public Observer, public Subject
     // session_name -> VLAN | monitor_port_alias | next_hop_ip
     map<string, string> m_recoverySessionMap;
 
+    bool isHwResourcesAvailable();
+
     task_process_status createEntry(const string&, const vector<FieldValueTuple>&);
     task_process_status deleteEntry(const string&);