Adding support to get a list of all reachable switch-id's from a fabric port

Signed-off-by: Harjot Singh <[email protected]>

Author: harjotsinghpawra

doc/VoQ/SAI-Proposal-VoQ-Switch.md

@@ -764,6 +764,22 @@ typedef enum _sai_port_stat_t
 } sai_port_stat_t;
 ```
 
+### 2.3.9 Fabric Port Reachability List
+
+The port reachability list attribute returns a list, that has all the remote switch ID reachable through this fabric port. The reachability list attribute
+can be queried on each fabric port retrieved from the fabric port list switch attribute.
+
+```c
+
+/**
+* @brief Fabric port reachability for all remote reachable switches
+*
+* @type sai_u16_list_t
+* @flags READ_ONLY
+*/
+SAI_PORT_ATTR_FABRIC_REACHABILITY_LIST,
+```
+
 ## 2.4 Queue Attributes, Types, and APIs
 
 ## 2.4.1 New Queue Types

inc/saiport.h

@@ -2520,6 +2520,14 @@ typedef enum _sai_port_attr_t
      */
     SAI_PORT_ATTR_POE_PORT_ID,
 
+    /**
+     * @brief Fabric port reachability for all remote reachable switches
+     *
+     * @type sai_u16_list_t
+     * @flags READ_ONLY
+     */
+    SAI_PORT_ATTR_FABRIC_REACHABILITY_LIST,
+
     /**
      * @brief End of attributes
      */