Punt: socket register for exception dispatched/punted packets based on reason

- add to the Punt API to allow different descriptions of the desired packets: UDP or exceptions
- move the punt nodes into punt_node.c
- improve tests (test that the correct packets are punted to the registered socket)

Change-Id: I1a133dec88106874993cba1f5a439cd26b2fef72
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 587 insertions, 0 deletions

diff --git a/src/vnet/ip/punt_node.c b/src/vnet/ip/punt_node.c
new file mode 100644
index 00000000000..53c8199342b
--- /dev/null
+++ b/src/vnet/ip/punt_node.c
@@ -0,0 +1,587 @@
+/*
+ * Copyright (c) 2016 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.
+ */
+
+/**
+ * @file
+ * @brief Local TCP/IP stack punt infrastructure.
+ *
+ * Provides a set of VPP nodes together with the relevant APIs and CLI
+ * commands in order to adjust and dispatch packets from the VPP data plane
+ * to the local TCP/IP stack
+ */
+
+#include <vnet/ip/ip.h>
+#include <vlib/vlib.h>
+#include <vnet/pg/pg.h>
+#include <vnet/udp/udp.h>
+#include <vnet/tcp/tcp.h>
+#include <vnet/sctp/sctp.h>
+#include <vnet/ip/punt.h>
+#include <vlib/unix/unix.h>
+
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/uio.h>
+#include <stdlib.h>
+
+typedef enum
+{
+#define punt_error(n,s) PUNT_ERROR_##n,
+#include <vnet/ip/punt_error.def>
+#undef punt_error
+  PUNT_N_ERROR,
+} punt_error_t;
+
+#define foreach_punt_next			\
+  _ (PUNT4, "ip4-punt")                         \
+  _ (PUNT6, "ip6-punt")
+
+typedef enum
+{
+#define _(s,n) PUNT_NEXT_##s,
+  foreach_punt_next
+#undef _
+    PUNT_N_NEXT,
+} punt_next_t;
+
+enum punt_socket_rx_next_e
+{
+  PUNT_SOCKET_RX_NEXT_INTERFACE_OUTPUT,
+  PUNT_SOCKET_RX_NEXT_IP4_LOOKUP,
+  PUNT_SOCKET_RX_NEXT_IP6_LOOKUP,
+  PUNT_SOCKET_RX_N_NEXT
+};
+
+#define punt_next_punt(is_ip4) (is_ip4 ? PUNT_NEXT_PUNT4 : PUNT_NEXT_PUNT6)
+
+/** @brief IPv4/IPv6 UDP punt node main loop.
+
+    This is the main loop inline function for IPv4/IPv6 UDP punt
+    transition node.
+
+    @param vm vlib_main_t corresponding to the current thread
+    @param node vlib_node_runtime_t
+    @param frame vlib_frame_t whose contents should be dispatched
+    @param is_ipv4 indicates if called for IPv4 or IPv6 node
+*/
+always_inline uword
+udp46_punt_inline (vlib_main_t * vm,
+		   vlib_node_runtime_t * node,
+		   vlib_frame_t * from_frame, int is_ip4)
+{
+  u32 n_left_from, *from, *to_next;
+  word advance;
+
+  from = vlib_frame_vector_args (from_frame);
+  n_left_from = from_frame->n_vectors;
+
+  /* udp[46]_lookup hands us the data payload, not the IP header */
+  if (is_ip4)
+    advance = -(sizeof (ip4_header_t) + sizeof (udp_header_t));
+  else
+    advance = -(sizeof (ip6_header_t) + sizeof (udp_header_t));
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, punt_next_punt (is_ip4), to_next,
+			   n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0;
+	  vlib_buffer_t *b0;
+
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  vlib_buffer_advance (b0, advance);
+	  b0->error = node->errors[PUNT_ERROR_UDP_PORT];
+	}
+
+      vlib_put_next_frame (vm, node, punt_next_punt (is_ip4), n_left_to_next);
+    }
+
+  return from_frame->n_vectors;
+}
+
+static char *punt_error_strings[] = {
+#define punt_error(n,s) s,
+#include "punt_error.def"
+#undef punt_error
+};
+
+/** @brief IPv4 UDP punt node.
+    @node ip4-udp-punt
+
+    This is the IPv4 UDP punt transition node. It is registered as a next
+    node for the "ip4-udp-lookup" handling UDP port(s) requested for punt.
+    The buffer's current data pointer is adjusted to the original packet
+    IPv4 header. All buffers are dispatched to "error-punt".
+
+    @param vm vlib_main_t corresponding to the current thread
+    @param node vlib_node_runtime_t
+    @param frame vlib_frame_t whose contents should be dispatched
+
+    @par Graph mechanics: next index usage
+
+    @em Sets:
+    - <code>vnet_buffer(b)->current_data</code>
+    - <code>vnet_buffer(b)->current_len</code>
+
+    <em>Next Index:</em>
+    - Dispatches the packet to the "error-punt" node
+*/
+VLIB_NODE_FN (udp4_punt_node) (vlib_main_t * vm,
+			       vlib_node_runtime_t * node,
+			       vlib_frame_t * from_frame)
+{
+  return udp46_punt_inline (vm, node, from_frame, 1 /* is_ip4 */ );
+}
+
+/** @brief IPv6 UDP punt node.
+    @node ip6-udp-punt
+
+    This is the IPv6 UDP punt transition node. It is registered as a next
+    node for the "ip6-udp-lookup" handling UDP port(s) requested for punt.
+    The buffer's current data pointer is adjusted to the original packet
+    IPv6 header. All buffers are dispatched to "error-punt".
+
+    @param vm vlib_main_t corresponding to the current thread
+    @param node vlib_node_runtime_t
+    @param frame vlib_frame_t whose contents should be dispatched
+
+    @par Graph mechanics: next index usage
+
+    @em Sets:
+    - <code>vnet_buffer(b)->current_data</code>
+    - <code>vnet_buffer(b)->current_len</code>
+
+    <em>Next Index:</em>
+    - Dispatches the packet to the "error-punt" node
+*/
+VLIB_NODE_FN (udp6_punt_node) (vlib_main_t * vm,
+			       vlib_node_runtime_t * node,
+			       vlib_frame_t * from_frame)
+{
+  return udp46_punt_inline (vm, node, from_frame, 0 /* is_ip4 */ );
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (udp4_punt_node) = {
+  .name = "ip4-udp-punt",
+  /* Takes a vector of packets. */
+  .vector_size = sizeof (u32),
+
+  .n_errors = PUNT_N_ERROR,
+  .error_strings = punt_error_strings,
+
+  .n_next_nodes = PUNT_N_NEXT,
+  .next_nodes = {
+#define _(s,n) [PUNT_NEXT_##s] = n,
+     foreach_punt_next
+#undef _
+  },
+};
+
+VLIB_REGISTER_NODE (udp6_punt_node) = {
+  .name = "ip6-udp-punt",
+  /* Takes a vector of packets. */
+  .vector_size = sizeof (u32),
+
+  .n_errors = PUNT_N_ERROR,
+  .error_strings = punt_error_strings,
+
+  .n_next_nodes = PUNT_N_NEXT,
+  .next_nodes = {
+#define _(s,n) [PUNT_NEXT_##s] = n,
+     foreach_punt_next
+#undef _
+  },
+};
+/* *INDENT-ON* */
+
+typedef struct
+{
+  punt_client_t client;
+  u8 is_midchain;
+} udp_punt_trace_t;
+
+static u8 *
+format_udp_punt_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  udp_punt_trace_t *t = va_arg (*args, udp_punt_trace_t *);
+  u32 indent = format_get_indent (s);
+  s = format (s, "to: %s", t->client.caddr.sun_path);
+  if (t->is_midchain)
+    {
+      s = format (s, "\n%U(buffer is part of chain)", format_white_space,
+		  indent);
+    }
+  return s;
+}
+
+always_inline uword
+punt_socket_inline (vlib_main_t * vm,
+		    vlib_node_runtime_t * node,
+		    vlib_frame_t * frame,
+		    punt_type_t pt, ip_address_family_t af)
+{
+  u32 *buffers = vlib_frame_vector_args (frame);
+  uword n_packets = frame->n_vectors;
+  struct iovec *iovecs = 0;
+  punt_main_t *pm = &punt_main;
+  int i;
+
+  u32 node_index = AF_IP4 == af ? udp4_punt_socket_node.index :
+    udp6_punt_socket_node.index;
+
+  for (i = 0; i < n_packets; i++)
+    {
+      struct iovec *iov;
+      vlib_buffer_t *b;
+      uword l;
+      punt_packetdesc_t packetdesc;
+      punt_client_t *c;
+
+      b = vlib_get_buffer (vm, buffers[i]);
+
+      if (PUNT_TYPE_L4 == pt)
+	{
+	  /* Reverse UDP Punt advance */
+	  udp_header_t *udp;
+	  if (AF_IP4 == af)
+	    {
+	      vlib_buffer_advance (b, -(sizeof (ip4_header_t) +
+					sizeof (udp_header_t)));
+	      ip4_header_t *ip = vlib_buffer_get_current (b);
+	      udp = (udp_header_t *) (ip + 1);
+	    }
+	  else
+	    {
+	      vlib_buffer_advance (b, -(sizeof (ip6_header_t) +
+					sizeof (udp_header_t)));
+	      ip6_header_t *ip = vlib_buffer_get_current (b);
+	      udp = (udp_header_t *) (ip + 1);
+	    }
+
+	  u16 port = clib_net_to_host_u16 (udp->dst_port);
+
+	  /*
+	   * Find registerered client
+	   * If no registered client, drop packet and count
+	   */
+	  c = punt_client_l4_get (af, port);
+	}
+      else if (PUNT_TYPE_EXCEPTION == pt)
+	{
+	  c = punt_client_exception_get (b->punt_reason);
+	}
+      else
+	c = NULL;
+
+      if (PREDICT_FALSE (NULL == c))
+	{
+	  vlib_node_increment_counter (vm, node_index,
+				       PUNT_ERROR_SOCKET_TX_ERROR, 1);
+	  goto error;
+	}
+
+      struct sockaddr_un *caddr = &c->caddr;
+
+      if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
+	{
+	  udp_punt_trace_t *t;
+	  t = vlib_add_trace (vm, node, b, sizeof (t[0]));
+	  clib_memcpy_fast (&t->client, c, sizeof (t->client));
+	}
+
+      /* Re-set iovecs if present. */
+      if (iovecs)
+	_vec_len (iovecs) = 0;
+
+      /* Add packet descriptor */
+      packetdesc.sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
+      packetdesc.action = 0;
+      vec_add2 (iovecs, iov, 1);
+      iov->iov_base = &packetdesc;
+      iov->iov_len = sizeof (packetdesc);
+
+      /** VLIB buffer chain -> Unix iovec(s). */
+      vlib_buffer_advance (b, -(sizeof (ethernet_header_t)));
+      vec_add2 (iovecs, iov, 1);
+      iov->iov_base = b->data + b->current_data;
+      iov->iov_len = l = b->current_length;
+
+      if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT))
+	{
+	  do
+	    {
+	      b = vlib_get_buffer (vm, b->next_buffer);
+	      if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
+		{
+		  udp_punt_trace_t *t;
+		  t = vlib_add_trace (vm, node, b, sizeof (t[0]));
+		  clib_memcpy_fast (&t->client, c, sizeof (t->client));
+		  t->is_midchain = 1;
+		}
+
+	      vec_add2 (iovecs, iov, 1);
+
+	      iov->iov_base = b->data + b->current_data;
+	      iov->iov_len = b->current_length;
+	      l += b->current_length;
+	    }
+	  while (b->flags & VLIB_BUFFER_NEXT_PRESENT);
+	}
+
+      struct msghdr msg = {
+	.msg_name = caddr,
+	.msg_namelen = sizeof (*caddr),
+	.msg_iov = iovecs,
+	.msg_iovlen = vec_len (iovecs),
+      };
+
+      if (sendmsg (pm->socket_fd, &msg, 0) < (ssize_t) l)
+	vlib_node_increment_counter (vm, node_index,
+				     PUNT_ERROR_SOCKET_TX_ERROR, 1);
+      else
+	vlib_node_increment_counter (vm, node_index, PUNT_ERROR_SOCKET_TX, 1);
+    }
+
+error:
+  vlib_buffer_free (vm, buffers, n_packets);
+
+  return n_packets;
+}
+
+static uword
+udp4_punt_socket (vlib_main_t * vm,
+		  vlib_node_runtime_t * node, vlib_frame_t * from_frame)
+{
+  return punt_socket_inline (vm, node, from_frame, PUNT_TYPE_L4, AF_IP4);
+}
+
+static uword
+udp6_punt_socket (vlib_main_t * vm,
+		  vlib_node_runtime_t * node, vlib_frame_t * from_frame)
+{
+  return punt_socket_inline (vm, node, from_frame, PUNT_TYPE_L4, AF_IP6);
+}
+
+static uword
+exception_punt_socket (vlib_main_t * vm,
+		       vlib_node_runtime_t * node, vlib_frame_t * from_frame)
+{
+  return punt_socket_inline (vm, node, from_frame,
+			     PUNT_TYPE_EXCEPTION, AF_IP4);
+}
+
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (udp4_punt_socket_node) = {
+  .function = udp4_punt_socket,
+  .name = "ip4-udp-punt-socket",
+  .format_trace = format_udp_punt_trace,
+  .flags = VLIB_NODE_FLAG_IS_DROP,
+  /* Takes a vector of packets. */
+  .vector_size = sizeof (u32),
+  .n_errors = PUNT_N_ERROR,
+  .error_strings = punt_error_strings,
+};
+VLIB_REGISTER_NODE (udp6_punt_socket_node) = {
+  .function = udp6_punt_socket,
+  .name = "ip6-udp-punt-socket",
+  .format_trace = format_udp_punt_trace,
+  .flags = VLIB_NODE_FLAG_IS_DROP,
+  .vector_size = sizeof (u32),
+  .n_errors = PUNT_N_ERROR,
+  .error_strings = punt_error_strings,
+};
+VLIB_REGISTER_NODE (exception_punt_socket_node) = {
+  .function = exception_punt_socket,
+  .name = "exception-punt-socket",
+  .format_trace = format_udp_punt_trace,
+  .flags = VLIB_NODE_FLAG_IS_DROP,
+  .vector_size = sizeof (u32),
+  .n_errors = PUNT_N_ERROR,
+  .error_strings = punt_error_strings,
+};
+/* *INDENT-ON* */
+
+typedef struct
+{
+  enum punt_action_e action;
+  u32 sw_if_index;
+} punt_trace_t;
+
+static u8 *
+format_punt_trace (u8 * s, va_list * va)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
+  vnet_main_t *vnm = vnet_get_main ();
+  punt_trace_t *t = va_arg (*va, punt_trace_t *);
+  s = format (s, "%U Action: %d", format_vnet_sw_if_index_name,
+	      vnm, t->sw_if_index, t->action);
+  return s;
+}
+
+static uword
+punt_socket_rx_fd (vlib_main_t * vm, vlib_node_runtime_t * node, u32 fd)
+{
+  const uword buffer_size = vlib_buffer_get_default_data_size (vm);
+  u32 n_trace = vlib_get_trace_count (vm, node);
+  u32 next = node->cached_next_index;
+  u32 n_left_to_next, next_index;
+  u32 *to_next;
+  u32 error = PUNT_ERROR_NONE;
+  vlib_get_next_frame (vm, node, next, to_next, n_left_to_next);
+
+  /* $$$$ Only dealing with one buffer at the time for now */
+
+  u32 bi;
+  vlib_buffer_t *b;
+  punt_packetdesc_t packetdesc;
+  ssize_t size;
+  struct iovec io[2];
+
+  if (vlib_buffer_alloc (vm, &bi, 1) != 1)
+    {
+      error = PUNT_ERROR_NOBUFFER;
+      goto error;
+    }
+
+  b = vlib_get_buffer (vm, bi);
+  io[0].iov_base = &packetdesc;
+  io[0].iov_len = sizeof (packetdesc);
+  io[1].iov_base = b->data;
+  io[1].iov_len = buffer_size;
+
+  size = readv (fd, io, 2);
+  /* We need at least the packet descriptor plus a header */
+  if (size <= (int) (sizeof (packetdesc) + sizeof (ip4_header_t)))
+    {
+      vlib_buffer_free (vm, &bi, 1);
+      error = PUNT_ERROR_READV;
+      goto error;
+    }
+
+  b->flags = VNET_BUFFER_F_LOCALLY_ORIGINATED;
+  b->current_length = size - sizeof (packetdesc);
+
+  VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b);
+
+  switch (packetdesc.action)
+    {
+    case PUNT_L2:
+      vnet_buffer (b)->sw_if_index[VLIB_TX] = packetdesc.sw_if_index;
+      next_index = PUNT_SOCKET_RX_NEXT_INTERFACE_OUTPUT;
+      break;
+
+    case PUNT_IP4_ROUTED:
+      vnet_buffer (b)->sw_if_index[VLIB_RX] = packetdesc.sw_if_index;
+      vnet_buffer (b)->sw_if_index[VLIB_TX] = ~0;
+      next_index = PUNT_SOCKET_RX_NEXT_IP4_LOOKUP;
+      break;
+
+    case PUNT_IP6_ROUTED:
+      vnet_buffer (b)->sw_if_index[VLIB_RX] = packetdesc.sw_if_index;
+      vnet_buffer (b)->sw_if_index[VLIB_TX] = ~0;
+      next_index = PUNT_SOCKET_RX_NEXT_IP6_LOOKUP;
+      break;
+
+    default:
+      error = PUNT_ERROR_ACTION;
+      vlib_buffer_free (vm, &bi, 1);
+      goto error;
+    }
+
+  if (PREDICT_FALSE (n_trace > 0))
+    {
+      punt_trace_t *t;
+      vlib_trace_buffer (vm, node, next_index, b, 1 /* follow_chain */ );
+      vlib_set_trace_count (vm, node, --n_trace);
+      t = vlib_add_trace (vm, node, b, sizeof (*t));
+      t->sw_if_index = packetdesc.sw_if_index;
+      t->action = packetdesc.action;
+    }
+
+  to_next[0] = bi;
+  to_next++;
+  n_left_to_next--;
+
+  vlib_validate_buffer_enqueue_x1 (vm, node, next, to_next, n_left_to_next,
+				   bi, next_index);
+  vlib_put_next_frame (vm, node, next, n_left_to_next);
+  return 1;
+
+error:
+  vlib_node_increment_counter (vm, punt_socket_rx_node.index, error, 1);
+  return 0;
+}
+
+static uword
+punt_socket_rx (vlib_main_t * vm,
+		vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  punt_main_t *pm = &punt_main;
+  u32 total_count = 0;
+  int i;
+
+  for (i = 0; i < vec_len (pm->ready_fds); i++)
+    {
+      total_count += punt_socket_rx_fd (vm, node, pm->ready_fds[i]);
+      vec_del1 (pm->ready_fds, i);
+    }
+  return total_count;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (punt_socket_rx_node) =
+{
+ .function = punt_socket_rx,
+ .name = "punt-socket-rx",
+ .type = VLIB_NODE_TYPE_INPUT,
+ .state = VLIB_NODE_STATE_INTERRUPT,
+ .vector_size = 1,
+ .n_errors = PUNT_N_ERROR,
+ .error_strings = punt_error_strings,
+ .n_next_nodes = PUNT_SOCKET_RX_N_NEXT,
+ .next_nodes = {
+    [PUNT_SOCKET_RX_NEXT_INTERFACE_OUTPUT] = "interface-output",
+    [PUNT_SOCKET_RX_NEXT_IP4_LOOKUP] = "ip4-lookup",
+    [PUNT_SOCKET_RX_NEXT_IP6_LOOKUP] = "ip6-lookup",
+  },
+ .format_trace = format_punt_trace,
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */