Add a 64-byte interface "tag" for vhost and tap interfaces

This patch should dispose of spurious objections around interface tag
requirements, currently in use as excuses not to support the vpp ML2
plugin.

Add "u8 tag[64];" to the sw_interface_details message sent by vpp to
control-plane clients. Add u8 tag[64] to the create_vhost_user_if and
tap_connect APIs.

Added debug CLI to set/show/clear the interface tag on any vnet sw
interface. Added the sw_interface_tag_add_del API to set/clear
tags on any vnet sw interface.

There can be no expectation of "tag atomicity" with respect to
physical hardware. Vpp discovers devices before establishing a
control-plane connection.

This patch upload verifies using the csit oper-161128 branch

Change-Id: If8520119e7a586c5ccf0fdda82484ac205622855
Signed-off-by: Dave Barach <dave@barachs.net>

3 files changed, 119 insertions, 6 deletions

diff --git a/vpp/vpp-api/api.c b/vpp/vpp-api/api.c
index 2c0256cc34e..b5253726915 100644
--- a/vpp/vpp-api/api.c
+++ b/vpp/vpp-api/api.c
@@ -255,8 +255,8 @@ _(COP_INTERFACE_ENABLE_DISABLE, cop_interface_enable_disable)		\
 _(COP_WHITELIST_ENABLE_DISABLE, cop_whitelist_enable_disable)		\
 _(GET_NODE_GRAPH, get_node_graph)                                       \
 _(SW_INTERFACE_CLEAR_STATS, sw_interface_clear_stats)                   \
-_(IOAM_ENABLE, ioam_enable)                                 \
-_(IOAM_DISABLE, ioam_disable)                                 \
+_(IOAM_ENABLE, ioam_enable)                                             \
+_(IOAM_DISABLE, ioam_disable)                                           \
 _(LISP_ADD_DEL_LOCATOR_SET, lisp_add_del_locator_set)                   \
 _(LISP_ADD_DEL_LOCATOR, lisp_add_del_locator)                           \
 _(LISP_ADD_DEL_LOCAL_EID, lisp_add_del_local_eid)                       \
@@ -332,7 +332,8 @@ _(IP_FIB_DUMP, ip_fib_dump)                                             \
 _(IP_FIB_DETAILS, ip_fib_details)                                       \
 _(IP6_FIB_DUMP, ip6_fib_dump)                                           \
 _(IP6_FIB_DETAILS, ip6_fib_details)                                     \
-_(FEATURE_ENABLE_DISABLE, feature_enable_disable)
+_(FEATURE_ENABLE_DISABLE, feature_enable_disable)			\
+_(SW_INTERFACE_TAG_ADD_DEL, sw_interface_tag_add_del)
 
 #define QUOTE_(x) #x
 #define QUOTE(x) QUOTE_(x)
@@ -1997,8 +1998,10 @@ vl_api_tap_connect_t_handler (vl_api_tap_connect_t * mp, vlib_main_t * vm)
 {
   int rv;
   vl_api_tap_connect_reply_t *rmp;
+  vnet_main_t *vnm = vnet_get_main ();
   unix_shared_memory_queue_t *q;
   u32 sw_if_index = (u32) ~ 0;
+  u8 *tag;
 
   rv = vnet_tap_connect_renumber (vm, mp->tap_name,
 				  mp->use_random_mac ? 0 : mp->mac_address,
@@ -2009,6 +2012,14 @@ vl_api_tap_connect_t_handler (vl_api_tap_connect_t * mp, vlib_main_t * vm)
   if (!q)
     return;
 
+  /* Add tag if supplied */
+  if (rv == 0 && mp->tag[0])
+    {
+      mp->tag[ARRAY_LEN (mp->tag) - 1] = 0;
+      tag = format (0, "%s%c", mp->tag, 0);
+      vnet_set_sw_interface_tag (vnm, tag, sw_if_index);
+    }
+
   rmp = vl_msg_api_alloc (sizeof (*rmp));
   rmp->_vl_msg_id = ntohs (VL_API_TAP_CONNECT_REPLY);
   rmp->context = mp->context;
@@ -2054,6 +2065,11 @@ vl_api_tap_delete_t_handler (vl_api_tap_delete_t * mp, vlib_main_t * vm)
   u32 sw_if_index = ntohl (mp->sw_if_index);
 
   rv = vnet_tap_delete (vm, sw_if_index);
+  if (!rv)
+    {
+      vnet_main_t *vnm = vnet_get_main ();
+      vnet_clear_sw_interface_tag (vnm, sw_if_index);
+    }
 
   q = vl_api_client_index_to_input_queue (mp->client_index);
   if (!q)
@@ -2684,7 +2700,9 @@ send_sw_interface_details (vpe_api_main_t * am,
 			   u8 * interface_name, u32 context)
 {
   vl_api_sw_interface_details_t *mp;
+  vnet_main_t *vnm = vnet_get_main ();
   vnet_hw_interface_t *hi;
+  u8 *tag;
 
   hi = vnet_get_sup_hw_interface (am->vnet_main, swif->sw_if_index);
 
@@ -2752,6 +2770,10 @@ send_sw_interface_details (vpe_api_main_t * am,
 	}
     }
 
+  tag = vnet_get_sw_interface_tag (vnm, swif->sw_if_index);
+  if (tag)
+    strncpy ((char *) mp->tag, (char *) tag, ARRAY_LEN (mp->tag) - 1);
+
   vl_msg_api_send_shmem (q, (u8 *) & mp);
 }
 
@@ -4020,7 +4042,6 @@ vl_api_create_vhost_user_if_t_handler (vl_api_create_vhost_user_if_t * mp)
   int rv = 0;
   vl_api_create_vhost_user_if_reply_t *rmp;
   u32 sw_if_index = (u32) ~ 0;
-
   vnet_main_t *vnm = vnet_get_main ();
   vlib_main_t *vm = vlib_get_main ();
 
@@ -4029,6 +4050,19 @@ vl_api_create_vhost_user_if_t_handler (vl_api_create_vhost_user_if_t * mp)
 			     mp->renumber, ntohl (mp->custom_dev_instance),
 			     (mp->use_custom_mac) ? mp->mac_address : NULL);
 
+  /* Remember an interface tag for the new interface */
+  if (rv == 0)
+    {
+      /* If a tag was supplied... */
+      if (mp->tag[0])
+	{
+	  /* Make sure it's a proper C-string */
+	  mp->tag[ARRAY_LEN (mp->tag) - 1] = 0;
+	  u8 *tag = format (0, "%s%c", mp->tag, 0);
+	  vnet_set_sw_interface_tag (vnm, tag, sw_if_index);
+	}
+    }
+
   /* *INDENT-OFF* */
   REPLY_MACRO2(VL_API_CREATE_VHOST_USER_IF_REPLY,
   ({
@@ -4074,6 +4108,7 @@ vl_api_delete_vhost_user_if_t_handler (vl_api_delete_vhost_user_if_t * mp)
       if (!q)
 	return;
 
+      vnet_clear_sw_interface_tag (vnm, sw_if_index);
       send_sw_interface_flags_deleted (vam, q, sw_if_index);
     }
 }
@@ -9113,6 +9148,37 @@ vl_api_feature_enable_disable_t_handler (vl_api_feature_enable_disable_t * mp)
   REPLY_MACRO (VL_API_FEATURE_ENABLE_DISABLE_REPLY);
 }
 
+static void vl_api_sw_interface_tag_add_del_t_handler
+  (vl_api_sw_interface_tag_add_del_t * mp)
+{
+  vnet_main_t *vnm = vnet_get_main ();
+  vl_api_sw_interface_tag_add_del_reply_t *rmp;
+  int rv = 0;
+  u8 *tag;
+  u32 sw_if_index = ntohl (mp->sw_if_index);
+
+  VALIDATE_SW_IF_INDEX (mp);
+
+  if (mp->is_add)
+    {
+      if (mp->tag[0] == 0)
+	{
+	  rv = VNET_API_ERROR_INVALID_VALUE;
+	  goto out;
+	}
+
+      mp->tag[ARRAY_LEN (mp->tag) - 1] = 0;
+      tag = format (0, "%s%c", mp->tag, 0);
+      vnet_set_sw_interface_tag (vnm, tag, sw_if_index);
+    }
+  else
+    vnet_clear_sw_interface_tag (vnm, sw_if_index);
+
+  BAD_SW_IF_INDEX_LABEL;
+out:
+  REPLY_MACRO (VL_API_SW_INTERFACE_TAG_ADD_DEL_REPLY);
+}
+
 #define BOUNCE_HANDLER(nn)                                              \
 static void vl_api_##nn##_t_handler (                                   \
     vl_api_##nn##_t *mp)                                                \
diff --git a/vpp/vpp-api/custom_dump.c b/vpp/vpp-api/custom_dump.c
index 28d3341de8c..a36a8a43af0 100644
--- a/vpp/vpp-api/custom_dump.c
+++ b/vpp/vpp-api/custom_dump.c
@@ -431,7 +431,8 @@ static void *vl_api_tap_connect_t_print
   s = format (s, "tapname %s ", mp->tap_name);
   if (mp->use_random_mac)
     s = format (s, "random-mac ");
-
+  if (mp->tag[0])
+    s = format (s, "tag %s ", mp->tag);
   if (memcmp (mp->mac_address, null_mac, 6))
     s = format (s, "mac %U ", format_ethernet_address, mp->mac_address);
 
@@ -1568,6 +1569,8 @@ static void *vl_api_create_vhost_user_if_t_print
     s = format (s, "server ");
   if (mp->renumber)
     s = format (s, "renumber %d ", ntohl (mp->custom_dev_instance));
+  if (mp->tag[0])
+    s = format (s, "tag %s", mp->tag);
 
   FINISH;
 }
@@ -2926,6 +2929,21 @@ static void *vl_api_feature_enable_disable_t_print
   FINISH;
 }
 
+static void *vl_api_sw_interface_tag_add_del_t_print
+  (vl_api_sw_interface_tag_add_del_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: sw_interface_tag_add_del ");
+  s = format (s, "sw_if_index %d ", ntohl (mp->sw_if_index));
+  if (mp->is_add)
+    s = format (s, "tag %s ", mp->tag);
+  else
+    s = format (s, "del ");
+
+  FINISH;
+}
+
 #define foreach_custom_print_no_arg_function                            \
 _(lisp_eid_table_vni_dump)                                              \
 _(lisp_map_resolver_dump)                                               \
@@ -3098,7 +3116,8 @@ _(IOAM_ENABLE, ioam_enable)                                             \
 _(IOAM_DISABLE, ioam_disable)                                           \
 _(IP_FIB_DUMP, ip_fib_dump)                                             \
 _(IP6_FIB_DUMP, ip6_fib_dump)                                           \
-_(FEATURE_ENABLE_DISABLE, feature_enable_disable)
+_(FEATURE_ENABLE_DISABLE, feature_enable_disable)			\
+_(SW_INTERFACE_TAG_ADD_DEL, sw_interface_tag_add_del)
   void
 vl_msg_api_custom_dump_configure (api_main_t * am)
 {
diff --git a/vpp/vpp-api/vpe.api b/vpp/vpp-api/vpe.api
index 5ab21029fd3..bcc3f4ec1b3 100644
--- a/vpp/vpp-api/vpe.api
+++ b/vpp/vpp-api/vpe.api
@@ -117,6 +117,7 @@ define sw_interface_details
   u32 vtr_push_dot1q;		// ethertype of first pushed tag is dot1q/dot1ad
   u32 vtr_tag1;			// first pushed tag
   u32 vtr_tag2;			// second pushed tag
+  u8 tag[64];
 };
 
 /* works */
@@ -226,6 +227,7 @@ define tap_connect
   u8 mac_address[6];
   u8 renumber;
   u32 custom_dev_instance;
+  u8 tag[64];
 };
 
 /** \brief Reply for tap connect request
@@ -2269,6 +2271,7 @@ define create_vhost_user_if
   u32 custom_dev_instance;
   u8 use_custom_mac;
   u8 mac_address[6];
+  u8 tag[64];
 };
 
 /** \brief vhost-user interface create response
@@ -5518,3 +5521,28 @@ define feature_enable_disable_reply
     u32 context;
     i32 retval;
 };
+
+/** \brief Set / clear software interface tag
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param sw_if_index - the interface
+    @param add_del - 1 = add, 0 = delete
+    @param tag - an ascii tag
+*/
+define sw_interface_tag_add_del {
+    u32 client_index;
+    u32 context;
+    u8 is_add;
+    u32 sw_if_index;
+    u8 tag[64];
+};
+
+/** \brief Reply to set / clear software interface tag
+    @param context - sender context which was passed in the request
+    @param retval - return code for the request
+*/
+define sw_interface_tag_add_del_reply
+{
+    u32 context;
+    i32 retval;
+};