VPP-203 Find the relative next node index by node names

vat# get_next_index node-name vxlan4-input next-node-name l2-input
next node index 1

Change-Id: Ib71be8a408d08d59b0ed7dfb6ada9711cf29bd69
Signed-off-by: Keith Burns (alagalah) <alagalah@gmail.com>

3 files changed, 83 insertions, 3 deletions

diff --git a/vpp/vpp-api/api.c b/vpp/vpp-api/api.c
index f3909287c17..f6b1b739251 100644
--- a/vpp/vpp-api/api.c
+++ b/vpp/vpp-api/api.c
@@ -368,7 +368,8 @@ _(CLASSIFY_TABLE_INFO,classify_table_info)                              \
 _(CLASSIFY_SESSION_DUMP,classify_session_dump)                          \
 _(CLASSIFY_SESSION_DETAILS,classify_session_details)                    \
 _(IPFIX_ENABLE,ipfix_enable)                                            \
-_(IPFIX_DUMP,ipfix_dump)
+_(IPFIX_DUMP,ipfix_dump)                                                \
+_(GET_NEXT_INDEX, get_next_index)
 
 #define QUOTE_(x) #x
 #define QUOTE(x) QUOTE_(x)
@@ -4243,6 +4244,48 @@ static void vl_api_get_node_index_t_handler
     }))
 }
 
+static void vl_api_get_next_index_t_handler
+(vl_api_get_next_index_t * mp)
+{
+    vlib_main_t * vm = vlib_get_main();
+    vl_api_get_next_index_reply_t * rmp;
+    vlib_node_t * node, * next_node;
+    int rv = 0;
+    u32 next_node_index = ~0, next_index = ~0;
+    uword * p;
+
+    node = vlib_get_node_by_name (vm, mp->node_name);
+
+    if (node == 0) {
+        rv = VNET_API_ERROR_NO_SUCH_NODE;
+        goto out;
+    }
+
+    next_node = vlib_get_node_by_name (vm, mp->next_name);
+
+    if (next_node == 0) {
+        rv = VNET_API_ERROR_NO_SUCH_NODE2;
+        goto out;
+    }
+    else
+        next_node_index = next_node->index;
+
+    p = hash_get (node->next_slot_by_node, next_node_index);
+
+    if (p == 0) {
+        rv = VNET_API_ERROR_NO_SUCH_ENTRY;
+        goto out;
+    }
+    else
+        next_index = p[0];
+
+ out:
+    REPLY_MACRO2(VL_API_GET_NEXT_INDEX_REPLY,
+    ({
+        rmp->next_index = ntohl(next_index);
+    }));
+}
+
 static void vl_api_add_node_next_t_handler
 (vl_api_add_node_next_t * mp)
 {
diff --git a/vpp/vpp-api/custom_dump.c b/vpp/vpp-api/custom_dump.c
index 9967d5b9630..4e8b0642763 100644
--- a/vpp/vpp-api/custom_dump.c
+++ b/vpp/vpp-api/custom_dump.c
@@ -1875,6 +1875,18 @@ static void *vl_api_ipfix_dump_t_print
     FINISH;
 }
 
+static void *vl_api_get_next_index_t_print
+(vl_api_get_next_index_t * mp, void *handle)
+{
+    u8 * s;
+
+    s = format (0, "SCRIPT: get_next_index ");
+    s = format (s, "node-name %s ", mp->node_name);
+    s = format (s, "next-node-name %s ", mp->next_name);
+
+    FINISH;
+}
+
 #define foreach_custom_print_function                                   \
 _(CREATE_LOOPBACK, create_loopback)                                     \
 _(SW_INTERFACE_SET_FLAGS, sw_interface_set_flags)                       \
@@ -1972,9 +1984,10 @@ _(CLASSIFY_TABLE_BY_INTERFACE, classify_table_by_interface)             \
 _(CLASSIFY_TABLE_INFO,classify_table_info)                              \
 _(CLASSIFY_SESSION_DUMP,classify_session_dump)                          \
 _(IPFIX_ENABLE,ipfix_enable)                                            \
-_(IPFIX_DUMP,ipfix_dump)
+_(IPFIX_DUMP,ipfix_dump)                                                \
+_(GET_NEXT_INDEX, get_next_index)
 
-void vl_msg_api_custom_dump_configure (api_main_t *am) 
+void vl_msg_api_custom_dump_configure (api_main_t *am)
 {
 #define _(n,f) am->msg_print_handlers[VL_API_##n]       \
     = (void *) vl_api_##f##_t_print;
diff --git a/vpp/vpp-api/vpe.api b/vpp/vpp-api/vpe.api
index dd50d8400f8..25e6ebaacc9 100644
--- a/vpp/vpp-api/vpe.api
+++ b/vpp/vpp-api/vpe.api
@@ -4087,3 +4087,27 @@ manual_java define ipfix_details {
     u32 path_mtu;
     u32 template_interval;
 };
+
+/** \brief Query relative index via node names
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param node_name - name of node to find relative index from
+    @param next_name - next node from node_name to find relative index of
+*/
+define get_next_index {
+    u32 client_index;
+    u32 context;
+    u8 node_name[64];
+    u8 next_name[64];
+};
+
+/** \brief Reply for get next node index
+    @param context - sender context which was passed in the request
+    @param retval - return value
+    @param next_index - index of the next_node
+*/
+define get_next_index_reply {
+    u32 context;
+    i32 retval;
+    u32 next_index;
+};