Plugin for IP-Address to Interface Punting

This plugin provides per-ip address to interface punting.

When at least one rule is defined, the plugin receives all packets
which destination is one of VPP's address but which was not processed
by VPP (e.g., a TCP packet on a port that is not open, or a packet
for a protocol which is not attached).

Based on the set of configured rules, the destination address of each
packet is used to send the packet on the associated interface.

This plugin allows multiple containers to use
VPP's TCP stack (or other features provided by VPP) while still
being able to receive additional packets.

Change-Id: I3e69bb7d98183bf5163cb9ecb564cb482de252ce
Signed-off-by: Pierre Pfister <ppfister@cisco.com>

1 files changed, 484 insertions, 0 deletions

diff --git a/src/plugins/stn/stn.c b/src/plugins/stn/stn.c
new file mode 100644
index 00000000000..a9e6a98ebed
--- /dev/null
+++ b/src/plugins/stn/stn.c
@@ -0,0 +1,484 @@
+/*
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stn/stn.h>
+
+#include <vnet/plugin/plugin.h>
+#include <vpp/app/version.h>
+#include <vnet/ip/format.h>
+#include <vnet/ethernet/packet.h>
+#include <vnet/udp/udp.h>
+#include <vnet/tcp/tcp.h>
+
+stn_main_t stn_main;
+static vlib_node_registration_t stn_ip4_punt;
+static vlib_node_registration_t stn_ip6_punt;
+
+static u8 stn_hw_addr_local[6] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
+static u8 stn_hw_addr_dst[6] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x02};
+
+static ethernet_header_t stn_ip4_ethernet_header = {};
+static ethernet_header_t stn_ip6_ethernet_header = {};
+
+typedef struct {
+  clib_bihash_kv_16_8_t kv;
+} stn_ip46_punt_trace_t;
+
+static u8 *
+format_stn_rule (u8 * s, va_list * args)
+{
+  stn_rule_t *r = va_arg (*args, stn_rule_t *);
+  stn_main_t *stn = &stn_main;
+  u32 indent = format_get_indent (s);
+  u32 node_index = ip46_address_is_ip4(&r->address)?stn_ip4_punt.index:stn_ip6_punt.index;
+  vlib_node_t *next_node = vlib_get_next_node(vlib_get_main(), node_index, r->next_node_index);
+  s = format (s, "rule_index: %d\n", r - stn->rules);
+  s = format (s, "%Uaddress: %U\n", format_white_space, indent,
+	      format_ip46_address, &r->address, IP46_TYPE_ANY);
+  s = format (s, "%Uiface: %U (%d)\n", format_white_space, indent,
+  	      format_vnet_sw_if_index_name, vnet_get_main(), r->sw_if_index,
+	      r->sw_if_index);
+  s = format (s, "%Unext_node: %s (%d)", format_white_space, indent,
+	      next_node->name, next_node->index);
+  return s;
+}
+
+static_always_inline u8 *
+format_stn_ip46_punt_trace (u8 * s, va_list * args, u8 is_ipv4)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  stn_ip46_punt_trace_t *t = va_arg (*args, stn_ip46_punt_trace_t *);
+  u32 indent = format_get_indent (s);
+
+  format (s, "dst_address: %U\n", format_ip46_address,
+	  (ip46_address_t *)&t->kv.key, IP46_TYPE_ANY);
+
+  if (t->kv.value == ~(0L))
+    {
+      s = format (s, "%Urule: none", format_white_space, indent);
+    }
+  else
+    {
+      s = format (s, "%Urule:\n%U%U", format_white_space, indent,
+		     format_white_space, indent + 2,
+		     format_stn_rule, &stn_main.rules[t->kv.value]);
+    }
+  return s;
+}
+
+static void
+stn_punt_fn (vlib_main_t * vm,
+	           vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
+  stn_main_t *stn = &stn_main;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      /* Single loop */
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 pi0;
+	  vlib_buffer_t *p0;
+	  u32 next0;
+
+	  pi0 = to_next[0] = from[0];
+	  from += 1;
+	  n_left_from -= 1;
+	  to_next += 1;
+	  n_left_to_next -= 1;
+
+	  p0 = vlib_get_buffer (vm, pi0);
+
+	  ip4_header_t *ip = vlib_buffer_get_current(p0);
+	  if ((ip->ip_version_and_header_length & 0xf0) == 0x40)
+	    next0 = stn->punt_to_stn_ip4_next_index;
+	  else
+	    next0 = stn->punt_to_stn_ip6_next_index;
+
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					   n_left_to_next, pi0, next0);
+	}
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+}
+
+typedef enum
+{
+  STN_IP_PUNT_DROP,
+  STN_IP_PUNT_N_NEXT,
+} stn_ip_punt_next_t;
+
+static_always_inline uword
+stn_ip46_punt_fn (vlib_main_t * vm,
+	           vlib_node_runtime_t * node, vlib_frame_t * frame,
+		   u8 is_ipv4)
+{
+  u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
+  stn_main_t *stn = &stn_main;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      /* Single loop */
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 pi0;
+	  vlib_buffer_t *p0;
+	  clib_bihash_kv_16_8_t kv;
+	  u32 next0 = STN_IP_PUNT_DROP;
+
+	  pi0 = to_next[0] = from[0];
+	  from += 1;
+	  n_left_from -= 1;
+	  to_next += 1;
+	  n_left_to_next -= 1;
+
+	  p0 = vlib_get_buffer (vm, pi0);
+
+	  if (is_ipv4)
+	    {
+	      ip4_header_t *hdr = (ip4_header_t *) vlib_buffer_get_current(p0);
+	      ip46_address_set_ip4((ip46_address_t *)kv.key, &hdr->dst_address);
+	    }
+	  else
+	    {
+	      ip6_header_t *hdr = (ip6_header_t *) vlib_buffer_get_current(p0);
+	      kv.key[0] = hdr->dst_address.as_u64[0];
+	      kv.key[1] = hdr->dst_address.as_u64[1];
+	    }
+
+	  kv.value = ~(0L);
+	  clib_bihash_search_inline_16_8 (&stn->rule_by_address_table, &kv);
+	  if (kv.value != ~(0L))
+	    {
+	      ethernet_header_t *eth;
+	      stn_rule_t *r = &stn->rules[kv.value];
+	      vnet_buffer(p0)->sw_if_index[VLIB_TX] = r->sw_if_index;
+	      next0 = r->next_node_index;
+	      vlib_buffer_advance(p0, -sizeof(*eth));
+	      eth = (ethernet_header_t *) vlib_buffer_get_current(p0);
+	      if (is_ipv4)
+		clib_memcpy(eth, &stn_ip4_ethernet_header, sizeof(*eth));
+	      else
+		clib_memcpy(eth, &stn_ip6_ethernet_header, sizeof(*eth));
+	    }
+
+	  if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      stn_ip46_punt_trace_t *tr =
+		  vlib_add_trace (vm, node, p0, sizeof (*tr));
+	      tr->kv = kv;
+	    }
+
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					   n_left_to_next, pi0, next0);
+	}
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  return frame->n_vectors;
+}
+
+
+#define foreach_stn_ip_punt_error \
+ _(NONE, "no error")
+
+typedef enum {
+#define _(sym,str) STN_IP_punt_ERROR_##sym,
+  foreach_stn_ip_punt_error
+#undef _
+  STN_IP_PUNT_N_ERROR,
+} ila_error_t;
+
+static char *stn_ip_punt_error_strings[] = {
+#define _(sym,string) string,
+    foreach_stn_ip_punt_error
+#undef _
+};
+
+u8 *
+format_stn_ip6_punt_trace (u8 * s, va_list * args)
+{
+  return format_stn_ip46_punt_trace (s, args, 0);
+}
+
+static uword
+stn_ip6_punt_fn (vlib_main_t * vm,
+	           vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  return stn_ip46_punt_fn(vm, node, frame, 0);
+}
+
+/** *INDENT-OFF* */
+VLIB_REGISTER_NODE (stn_ip6_punt, static) =
+{
+  .function = stn_ip6_punt_fn,
+  .name = "stn-ip6-punt",
+  .vector_size = sizeof (u32),
+  .format_trace = format_stn_ip6_punt_trace,
+  .n_errors = STN_IP_PUNT_N_ERROR,
+  .error_strings = stn_ip_punt_error_strings,
+  .n_next_nodes = STN_IP_PUNT_N_NEXT,
+  .next_nodes =
+  {
+      [STN_IP_PUNT_DROP] = "error-drop"
+  },
+};
+/** *INDENT-ON* */
+
+u8 *
+format_stn_ip4_punt_trace (u8 * s, va_list * args)
+{
+  return format_stn_ip46_punt_trace (s, args, 1);
+}
+
+static uword
+stn_ip4_punt_fn (vlib_main_t * vm,
+	           vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  return stn_ip46_punt_fn(vm, node, frame, 1);
+}
+
+/** *INDENT-OFF* */
+VLIB_REGISTER_NODE (stn_ip4_punt, static) =
+{
+  .function = stn_ip4_punt_fn,
+  .name = "stn-ip4-punt",
+  .vector_size = sizeof (u32),
+  .format_trace = format_stn_ip4_punt_trace,
+  .n_errors = STN_IP_PUNT_N_ERROR,
+  .error_strings = stn_ip_punt_error_strings,
+  .n_next_nodes = STN_IP_PUNT_N_NEXT,
+  .next_nodes =
+  {
+      [STN_IP_PUNT_DROP] = "error-drop",
+  },
+};
+/** *INDENT-ON* */
+
+clib_error_t *
+stn_init (vlib_main_t * vm)
+{
+  stn_main_t *stn = &stn_main;
+  stn->rules = 0;
+  clib_bihash_init_16_8(&stn->rule_by_address_table, "stn addresses",
+			1024, 1<<20);
+
+  clib_memcpy(stn_ip4_ethernet_header.dst_address, stn_hw_addr_dst, 6);
+  clib_memcpy(stn_ip4_ethernet_header.src_address, stn_hw_addr_local, 6);
+  stn_ip4_ethernet_header.type = clib_host_to_net_u16(ETHERNET_TYPE_IP4);
+
+  clib_memcpy(stn_ip6_ethernet_header.dst_address, stn_hw_addr_dst, 6);
+  clib_memcpy(stn_ip6_ethernet_header.src_address, stn_hw_addr_local, 6);
+  stn_ip6_ethernet_header.type = clib_host_to_net_u16(ETHERNET_TYPE_IP6);
+
+  u32 punt_node_index = vlib_get_node_by_name(vm, (u8 *)"error-punt")->index;
+  stn->punt_to_stn_ip4_next_index =
+      vlib_node_add_next(vm, punt_node_index, stn_ip4_punt.index);
+  stn->punt_to_stn_ip6_next_index =
+        vlib_node_add_next(vm, punt_node_index, stn_ip6_punt.index);
+
+  return stn_api_init (vm, stn);
+
+  return NULL;
+}
+
+VLIB_INIT_FUNCTION (stn_init);
+
+/* *INDENT-OFF* */
+VLIB_PLUGIN_REGISTER () = {
+    .version = VPP_BUILD_VER,
+    .description = "VPP Steals the NIC for Container integration",
+};
+/* *INDENT-ON* */
+
+int stn_rule_add_del (stn_rule_add_del_args_t *args)
+{
+  vnet_main_t *vnm = vnet_get_main();
+  vlib_main_t *vm = vlib_get_main();
+  stn_main_t *stn = &stn_main;
+
+  stn_rule_t *r = NULL;
+  clib_bihash_kv_16_8_t kv;
+  kv.key[0] = args->address.as_u64[0];
+  kv.key[1] = args->address.as_u64[1];
+
+  if (clib_bihash_search_inline_16_8 (&stn->rule_by_address_table, &kv) == 0)
+    {
+      r = &stn->rules[kv.value];
+    }
+  else if (!args->del)
+    {
+      pool_get(stn->rules, r);
+      kv.value = r - stn->rules;
+      clib_bihash_add_del_16_8(&stn->rule_by_address_table, &kv, 1);
+      r->address = args->address;
+
+      stn->n_rules++;
+      if (stn->n_rules == 1)
+	{
+	  foreach_vlib_main({
+	    this_vlib_main->os_punt_frame = stn_punt_fn;
+	  });
+	  udp_punt_unknown(vm, 0, 1);
+	  udp_punt_unknown(vm, 1, 1);
+	  tcp_punt_unknown(vm, 0, 1);
+	  tcp_punt_unknown(vm, 1, 1);
+	}
+    }
+
+  if (!args->del)
+    {
+      /* Getting output node and adding it as next */
+      u32 output_node_index =
+          vnet_tx_node_index_for_sw_interface(vnm, args->sw_if_index);
+      u32 node_index = ip46_address_is_ip4(&args->address)?
+          stn_ip4_punt.index : stn_ip6_punt.index;
+
+      r->sw_if_index = args->sw_if_index;
+      r->next_node_index =
+	  vlib_node_add_next(vm, node_index, output_node_index);
+
+      /* enabling forwarding on the output node (might not be done since
+       * it is unnumbered) */
+      vnet_feature_enable_disable("ip4-unicast", "ip4-lookup", args->sw_if_index,
+				  1, 0, 0);
+      vnet_feature_enable_disable("ip6-unicast", "ip6-lookup", args->sw_if_index,
+				  1, 0, 0);
+      vnet_feature_enable_disable("ip4-unicast", "ip4-drop", args->sw_if_index,
+				  0, 0, 0);
+      vnet_feature_enable_disable("ip6-unicast", "ip6-drop", args->sw_if_index,
+				  0, 0, 0);
+    }
+  else if (r)
+    {
+      clib_bihash_add_del_16_8(&stn->rule_by_address_table, &kv, 0);
+      pool_put(stn->rules, r);
+
+      stn->n_rules--;
+      if (stn->n_rules == 0)
+	{
+	  foreach_vlib_main({
+	    this_vlib_main->os_punt_frame = NULL;
+	  });
+	}
+    }
+  else
+    {
+      return VNET_API_ERROR_NO_SUCH_ENTRY;
+    }
+
+  return 0;
+}
+
+static clib_error_t *
+show_stn_rules_fn (vlib_main_t * vm,
+		      unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  stn_main_t *stn = &stn_main;
+  u8 *s = 0;
+  stn_rule_t *rule;
+  pool_foreach(rule, stn->rules, {
+      s = format (s, "- %U\n", format_stn_rule, rule);
+  });
+
+  vlib_cli_output(vm, "%v", s);
+
+  vec_free(s);
+  return NULL;
+}
+
+VLIB_CLI_COMMAND (show_stn_rules_command, static) =
+{
+  .path = "show stn rules",
+  .short_help = "",
+  .function = show_stn_rules_fn,
+};
+
+static clib_error_t *
+stn_rule_fn (vlib_main_t * vm,
+		      unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  clib_error_t *error = 0;
+  stn_rule_add_del_args_t args = {};
+  u8 got_addr = 0;
+  u8 got_iface = 0;
+  int ret;
+
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "address %U", unformat_ip46_address,
+		    &args.address, IP46_TYPE_ANY))
+	got_addr = 1;
+      else if (unformat
+	       (line_input, "interface %U", unformat_vnet_sw_interface,
+		vnet_get_main(), &args.sw_if_index))
+	got_iface = 1;
+      else if (unformat (line_input, "del"))
+	args.del = 1;
+      else
+	{
+	  error = clib_error_return (0, "parse error: '%U'",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
+    }
+
+  if (!got_addr)
+    {
+      error = clib_error_return (0, "Missing address");
+      goto done;
+    }
+
+  if (!got_iface)
+    {
+      error = clib_error_return (0, "Missing interface");
+      goto done;
+    }
+
+  if ((ret = stn_rule_add_del (&args)))
+    {
+      error = clib_error_return (0, "stn_rule_add_del returned error %d", ret);
+      goto done;
+    }
+
+done:
+  unformat_free (line_input);
+  return error;
+}
+
+VLIB_CLI_COMMAND (stn_rule_command, static) =
+{
+  .path = "stn rule",
+  .short_help = "address <addr> interface <iface> [del]",
+  .function = stn_rule_fn,
+};