gtpu: support non-G-PDU packets and PDU Session

Updated the gtpu plugin code to support the PDU Session user plane protocol, required for 5G, as
specified in 3GPP TS 38.415 version 17.0.0. This enables some initial support of 5G gNodeB's with
the gtpu plugin.

New features:
- Basic support for the GTP-U Extension Header Flag.
Packets with one extension can now be decapsulated.
This enables basic support of the PDU Session user plane protocol (3GPP TS 38.415 version 17.0.0).
New tunnels can be created with a PDU enable flag and a 6-bit QoS Flow Identifier (QFI).
With this, encapsulated packets will have the PDU Session extension header, and the QFI set.

- Ability to forward GTP-U packets that are not handled by the plugin directly.
Only GTP-U packets with a message type of 255 (G-PDU) are handled directly.
However, 3GPP TS 29.281 defines several other message types like echo and error indication.
A new feature is added to optionally forward unknown or unsupported packets to a new IP address.
This works separately for unknown GTP-U message types, unknown TEIDs, and packets with an unknown
GTP-U header.
This allows both echo and error indications from a 5G gNodeB to be handled by a different system
outside VPP.

- Simple way to get metrics for active tunnels and on tunnel close.
In 5G session/tunnel lifetime is often short and created frequently.
The normal API becomes too slow and inaccurate when too many tunnels are created and deleted
every second.

Improvements:
- A clean ground structure to handle multiple message type in the future.
The code path for G-PDU packets is optimized for performance, representing the typical case.
Unsupported GTP-U packets enter a slow path that decodes the nature of the error.
This presents a easy hook to handle other message types in the future.

- Improved error reporting
When using traces there is more details in the tunnel descriptions.

- Updated the API with several enums.

Fixes:
- gtpu0->length field in IPv6 was computed with IPv4 header lengths in the encapsulation code.
- vec_set_len (t->rewrite, ...) size was computed with the IPv4 header size also for IPv6 tunnels.

Issues:
- This PR does not enable full support of the 3GPP specification.
In particular it only supports a single QoS/QFI flow for each tunnel.
It ignores all incoming extension header flags.

- API functions might change again when/if more support of the 3GPP TS 38.415 spec is added.

Note that I have bumped the API version to 2.1.0 as it seems to be the correct approach based on
my API changes.

Type: feature

Signed-off-by: Rune E. Jensen <runeerle@wgtwo.com>
Change-Id: I91cd2b31f2561f1b3fb1e46c4c34a5a3c71b4625

1 files changed, 364 insertions, 2 deletions

diff --git a/src/plugins/gtpu/gtpu_test.c b/src/plugins/gtpu/gtpu_test.c
index dcfe3d02666..fadcb82cb88 100644
--- a/src/plugins/gtpu/gtpu_test.c
+++ b/src/plugins/gtpu/gtpu_test.c
@@ -298,9 +298,9 @@ api_gtpu_add_del_tunnel (vat_main_t * vam)
 		       unformat_gtpu_decap_next, &decap_next_index))
       ;
       else if (unformat (line_input, "teid %d", &teid))
-      ;
+	;
       else if (unformat (line_input, "tteid %d", &tteid))
-      ;
+	;
       else
       {
 	errmsg ("parse error '%U'", format_unformat_error, line_input);
@@ -360,6 +360,175 @@ api_gtpu_add_del_tunnel (vat_main_t * vam)
   return ret;
 }
 
+static void
+vl_api_gtpu_add_del_tunnel_v2_reply_t_handler (
+  vl_api_gtpu_add_del_tunnel_v2_reply_t *mp)
+{
+  vat_main_t *vam = &vat_main;
+  i32 retval = ntohl (mp->retval);
+  if (vam->async_mode)
+    {
+      vam->async_errors += (retval < 0);
+    }
+  else
+    {
+      vam->retval = retval;
+      vam->sw_if_index = ntohl (mp->sw_if_index);
+      vam->result_ready = 1;
+    }
+}
+
+static int
+api_gtpu_add_del_tunnel_v2 (vat_main_t *vam)
+{
+  unformat_input_t *line_input = vam->input;
+  vl_api_gtpu_add_del_tunnel_v2_t *mp;
+  ip46_address_t src, dst;
+  u8 is_add = 1;
+  u8 ipv4_set = 0, ipv6_set = 0;
+  u8 src_set = 0;
+  u8 dst_set = 0;
+  u8 grp_set = 0;
+  u32 mcast_sw_if_index = ~0;
+  u32 encap_vrf_id = 0;
+  u32 decap_next_index = ~0;
+  u32 teid = 0, tteid = 0;
+  u8 pdu_extension = 0;
+  u32 qfi = 0;
+  int ret;
+
+  /* Can't "universally zero init" (={0}) due to GCC bug 53119 */
+  clib_memset (&src, 0, sizeof src);
+  clib_memset (&dst, 0, sizeof dst);
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "del"))
+	is_add = 0;
+      else if (unformat (line_input, "src %U", unformat_ip4_address, &src.ip4))
+	{
+	  ipv4_set = 1;
+	  src_set = 1;
+	}
+      else if (unformat (line_input, "dst %U", unformat_ip4_address, &dst.ip4))
+	{
+	  ipv4_set = 1;
+	  dst_set = 1;
+	}
+      else if (unformat (line_input, "src %U", unformat_ip6_address, &src.ip6))
+	{
+	  ipv6_set = 1;
+	  src_set = 1;
+	}
+      else if (unformat (line_input, "dst %U", unformat_ip6_address, &dst.ip6))
+	{
+	  ipv6_set = 1;
+	  dst_set = 1;
+	}
+      else if (unformat (line_input, "group %U %U", unformat_ip4_address,
+			 &dst.ip4, api_unformat_sw_if_index, vam,
+			 &mcast_sw_if_index))
+	{
+	  grp_set = dst_set = 1;
+	  ipv4_set = 1;
+	}
+      else if (unformat (line_input, "group %U", unformat_ip4_address,
+			 &dst.ip4))
+	{
+	  grp_set = dst_set = 1;
+	  ipv4_set = 1;
+	}
+      else if (unformat (line_input, "group %U %U", unformat_ip6_address,
+			 &dst.ip6, api_unformat_sw_if_index, vam,
+			 &mcast_sw_if_index))
+	{
+	  grp_set = dst_set = 1;
+	  ipv6_set = 1;
+	}
+      else if (unformat (line_input, "group %U", unformat_ip6_address,
+			 &dst.ip6))
+	{
+	  grp_set = dst_set = 1;
+	  ipv6_set = 1;
+	}
+      else if (unformat (line_input, "mcast_sw_if_index %u",
+			 &mcast_sw_if_index))
+	;
+      else if (unformat (line_input, "encap-vrf-id %d", &encap_vrf_id))
+	;
+      else if (unformat (line_input, "decap-next %U", unformat_gtpu_decap_next,
+			 &decap_next_index))
+	;
+      else if (unformat (line_input, "teid %d", &teid)) /* Change to %u ? */
+	;
+      else if (unformat (line_input, "tteid %d", &tteid)) /* Change to %u ? */
+	;
+      else if (unformat (line_input, "qfi %u", &qfi))
+	pdu_extension = 1;
+      else
+	{
+	  errmsg ("parse error '%U'", format_unformat_error, line_input);
+	  return -99;
+	}
+    }
+
+  if (is_add && src_set == 0)
+    {
+      errmsg ("tunnel src address not specified");
+      return -99;
+    }
+  if (dst_set == 0)
+    {
+      errmsg ("tunnel dst address not specified");
+      return -99;
+    }
+
+  if (grp_set && !ip46_address_is_multicast (&dst))
+    {
+      errmsg ("tunnel group address not multicast");
+      return -99;
+    }
+  if (grp_set && mcast_sw_if_index == ~0)
+    {
+      errmsg ("tunnel nonexistent multicast device");
+      return -99;
+    }
+  if (grp_set == 0 && ip46_address_is_multicast (&dst))
+    {
+      errmsg ("tunnel dst address must be unicast");
+      return -99;
+    }
+
+  if (ipv4_set && ipv6_set)
+    {
+      errmsg ("both IPv4 and IPv6 addresses specified");
+      return -99;
+    }
+  if (qfi > 31)
+    {
+      errmsg ("qfi max value is 31");
+      return -99;
+    }
+
+  M (GTPU_ADD_DEL_TUNNEL_V2, mp);
+
+  ip_address_encode (&src, ipv6_set ? IP46_TYPE_IP6 : IP46_TYPE_IP4,
+		     &mp->src_address);
+  ip_address_encode (&dst, ipv6_set ? IP46_TYPE_IP6 : IP46_TYPE_IP4,
+		     &mp->dst_address);
+  mp->encap_vrf_id = ntohl (encap_vrf_id);
+  mp->decap_next_index = ntohl (decap_next_index);
+  mp->mcast_sw_if_index = ntohl (mcast_sw_if_index);
+  mp->teid = ntohl (teid);
+  mp->tteid = ntohl (tteid);
+  mp->is_add = is_add;
+  mp->pdu_extension = pdu_extension;
+  mp->qfi = ntohl (qfi);
+
+  S (mp);
+  W (ret);
+  return ret;
+}
 static int
 api_gtpu_tunnel_update_tteid (vat_main_t * vam)
 {
@@ -436,6 +605,40 @@ static void vl_api_gtpu_tunnel_details_t_handler
 	 ntohl (mp->mcast_sw_if_index));
 }
 
+static void
+vl_api_gtpu_tunnel_v2_details_t_handler (vl_api_gtpu_tunnel_v2_details_t *mp)
+{
+  vat_main_t *vam = &vat_main;
+  ip46_address_t src;
+  ip46_address_t dst;
+  ip_address_decode (&mp->dst_address, &dst);
+  ip_address_decode (&mp->src_address, &src);
+  print (vam->ofp, "%11d%24U%24U%14d%18d%13d%13d%19d%15d%5d%15d%17d",
+	 ntohl (mp->sw_if_index), format_ip46_address, &src, IP46_TYPE_ANY,
+	 format_ip46_address, &dst, IP46_TYPE_ANY, ntohl (mp->encap_vrf_id),
+	 ntohl (mp->decap_next_index), ntohl (mp->teid), ntohl (mp->tteid),
+	 ntohl (mp->mcast_sw_if_index), mp->pdu_extension, mp->qfi,
+	 mp->is_forwarding, ntohl (mp->forwarding_type));
+}
+
+static void
+vl_api_gtpu_add_del_forward_reply_t_handler (
+  vl_api_gtpu_add_del_forward_reply_t *mp)
+{
+  vat_main_t *vam = &vat_main;
+  i32 retval = ntohl (mp->retval);
+  if (vam->async_mode)
+    {
+      vam->async_errors += (retval < 0);
+    }
+  else
+    {
+      vam->retval = retval;
+      vam->sw_if_index = ntohl (mp->sw_if_index);
+      vam->result_ready = 1;
+    }
+}
+
 static int
 api_gtpu_tunnel_dump (vat_main_t * vam)
 {
@@ -480,4 +683,163 @@ api_gtpu_tunnel_dump (vat_main_t * vam)
   return 0;
 }
 
+static int
+api_gtpu_tunnel_v2_dump (vat_main_t *vam)
+{
+  unformat_input_t *i = vam->input;
+  vl_api_gtpu_tunnel_dump_t *mp;
+  u32 sw_if_index;
+  u8 sw_if_index_set = 0;
+
+  /* Parse args required to build the message */
+  while (unformat_check_input (i) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (i, "sw_if_index %d", &sw_if_index))
+	sw_if_index_set = 1;
+      else
+	break;
+    }
+
+  if (sw_if_index_set == 0)
+    {
+      sw_if_index = ~0;
+    }
+
+  if (!vam->json_output)
+    {
+      print (vam->ofp, "%11s%24s%24s%14s%18s%13s%13s%19s%12s%5s%15s%17s",
+	     "sw_if_index", "src_address", "dst_address", "encap_vrf_id",
+	     "decap_next_index", "teid", "tteid", "mcast_sw_if_index",
+	     "pdu_extension", "qfi", "is_forwarding", "forwarding_type");
+    }
+
+  /* Get list of gtpu-tunnel interfaces */
+  M (GTPU_TUNNEL_DUMP, mp);
+
+  mp->sw_if_index = htonl (sw_if_index);
+
+  S (mp);
+
+  /* No status response for this API call.
+   * Wait 1 sec for any dump output before return to vat# */
+  sleep (1);
+
+  return 0;
+}
+
+static int
+api_gtpu_add_del_forward (vat_main_t *vam)
+{
+  unformat_input_t *line_input = vam->input;
+  vl_api_gtpu_add_del_forward_t *mp;
+  int ret;
+  u32 decap_next_index = GTPU_INPUT_NEXT_L2_INPUT;
+  int is_add = 1;
+  ip46_address_t dst;
+  u8 dst_set = 0;
+  u8 type = 0;
+  u8 ipv6_set = 0;
+  u32 encap_vrf_id;
+
+  /* Cant "universally zero init" (={0}) due to GCC bug 53119 */
+  clib_memset (&dst, 0, sizeof dst);
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "dst %U", unformat_ip4_address, &dst.ip4))
+	dst_set = 1;
+      else if (unformat (line_input, "dst %U", unformat_ip6_address, &dst.ip6))
+	{
+	  dst_set = 1;
+	  ipv6_set = 1;
+	}
+      else if (unformat (line_input, "decap-next %U", unformat_gtpu_decap_next,
+			 &decap_next_index))
+	;
+      else if (unformat (line_input, "encap-vrf-id %d", &encap_vrf_id))
+	;
+      else if (unformat (line_input, "del"))
+	is_add = 0;
+      else if (unformat (line_input, "bad-header"))
+	type |= GTPU_FORWARD_BAD_HEADER;
+      else if (unformat (line_input, "unknown-teid"))
+	type |= GTPU_FORWARD_UNKNOWN_TEID;
+      else if (unformat (line_input, "unknown-type"))
+	type |= GTPU_FORWARD_UNKNOWN_TYPE;
+      else
+	{
+	  errmsg ("parse error '%U'", format_unformat_error, line_input);
+	  return -99;
+	}
+    }
+
+  if (!dst_set)
+    {
+      errmsg ("dst must be set to a valid IP address");
+      return -99;
+    }
+
+  M (GTPU_ADD_DEL_FORWARD, mp);
+
+  mp->is_add = is_add;
+  ip_address_encode (&dst, ipv6_set ? IP46_TYPE_IP6 : IP46_TYPE_IP4,
+		     &mp->dst_address);
+  mp->forwarding_type = type;
+  mp->encap_vrf_id = ntohl (encap_vrf_id);
+  mp->decap_next_index = ntohl (decap_next_index);
+
+  S (mp);
+  W (ret);
+  return ret;
+}
+
+static int
+api_gtpu_get_transfer_counts (vat_main_t *vam)
+{
+  unformat_input_t *line_input = vam->input;
+  vl_api_gtpu_get_transfer_counts_t *mp;
+  u32 start_index;
+  u32 capacity;
+  int ret;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "start_index %u", &start_index))
+	;
+      else if (unformat (line_input, "capacity %u", &capacity))
+	;
+      else
+	{
+	  errmsg ("parse error '%U'", format_unformat_error, line_input);
+	  return -99;
+	}
+    }
+
+  M (GTPU_GET_TRANSFER_COUNTS, mp);
+  mp->sw_if_index_start = start_index;
+  mp->capacity = capacity;
+
+  S (mp); // TODO: Handle the prints somehow. But how is it done??
+  W (ret);
+  return ret;
+}
+
+static void
+vl_api_gtpu_get_transfer_counts_reply_t_handler (
+  vl_api_gtpu_get_transfer_counts_reply_t *mp)
+{
+  vat_main_t *vam = &vat_main;
+  i32 retval = ntohl (mp->retval);
+  if (vam->async_mode)
+    {
+      vam->async_errors += (retval < 0);
+    }
+  else
+    {
+      vam->retval = retval;
+      // TODO: Add reply here?
+      vam->result_ready = 1;
+    }
+}
+
 #include <gtpu/gtpu.api_test.c>