src/vnet/dhcp/dhcp_client_detect.c - fdio/vpp - Gitiles

 /*
  * DHCP feature; applied as an input feature to select DHCP packets
  *
  * Copyright (c) 2013 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 <vnet/dhcp/client.h>
 #include <vnet/udp/udp.h>

 #define foreach_dhcp_client_detect                    \
   _(EXTRACT, "Extract")

 typedef enum
 {
 #define _(sym,str) DHCP_CLIENT_DETECT_ERROR_##sym,
   foreach_dhcp_client_detect
 #undef _
     DHCP_CLIENT_DETECT_N_ERROR,
 } dhcp_client_detect_error_t;

 static char *dhcp_client_detect_error_strings[] = {
 #define _(sym,string) string,
   foreach_dhcp_client_detect
 #undef _
 };

 typedef enum
 {
 #define _(sym,str) DHCP_CLIENT_DETECT_NEXT_##sym,
   foreach_dhcp_client_detect
 #undef _
     DHCP_CLIENT_DETECT_N_NEXT,
 } dhcp_client_detect_next_t;

 /**
  * per-packet trace data
  */
 typedef struct dhcp_client_detect_trace_t_
 {
   /* per-pkt trace data */
   u8 extracted;
 } dhcp_client_detect_trace_t;

 static uword
 dhcp_client_detect_node_fn (vlib_main_t * vm,
 			    vlib_node_runtime_t * node, vlib_frame_t * frame)
 {
   dhcp_client_detect_next_t next_index;
   u16 dhcp_client_port_network_order;
   u32 n_left_from, *from, *to_next;
   u32 extractions;

   dhcp_client_port_network_order =
     clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_client);
   next_index = 0;
   extractions = 0;
   n_left_from = frame->n_vectors;
   from = vlib_frame_vector_args (frame);

   while (n_left_from > 0)
     {
       u32 n_left_to_next;

       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

       /*
        * This loop is optimised not so we can really quickly process DHCp
        * offers... but so we can quickly sift them out when the interface
        * is also receving 'normal' packets
        */
       while (n_left_from >= 8 && n_left_to_next >= 4)
 	{
 	  udp_header_t *udp0, *udp1, *udp2, *udp3;
 	  ip4_header_t *ip0, *ip1, *ip2, *ip3;
 	  vlib_buffer_t *b0, *b1, *b2, *b3;
 	  u32 next0, next1, next2, next3;
 	  u32 bi0, bi1, bi2, bi3;

 	  next0 = next1 = next2 = next3 = ~0;
 	  bi0 = to_next[0] = from[0];
 	  bi1 = to_next[1] = from[1];
 	  bi2 = to_next[2] = from[2];
 	  bi3 = to_next[3] = from[3];

 	  /* Prefetch next iteration. */
 	  {
 	    vlib_buffer_t *p2, *p3, *p4, *p5;

 	    p2 = vlib_get_buffer (vm, from[2]);
 	    p3 = vlib_get_buffer (vm, from[3]);
 	    p4 = vlib_get_buffer (vm, from[4]);
 	    p5 = vlib_get_buffer (vm, from[5]);

 	    vlib_prefetch_buffer_header (p2, STORE);
 	    vlib_prefetch_buffer_header (p3, STORE);
 	    vlib_prefetch_buffer_header (p4, STORE);
 	    vlib_prefetch_buffer_header (p5, STORE);

 	    CLIB_PREFETCH (p2->data, sizeof (ip0[0]) + sizeof (udp0[0]),
 			   STORE);
 	    CLIB_PREFETCH (p3->data, sizeof (ip0[0]) + sizeof (udp0[0]),
 			   STORE);
 	    CLIB_PREFETCH (p4->data, sizeof (ip0[0]) + sizeof (udp0[0]),
 			   STORE);
 	    CLIB_PREFETCH (p5->data, sizeof (ip0[0]) + sizeof (udp0[0]),
 			   STORE);
 	  }

 	  from += 4;
 	  to_next += 4;
 	  n_left_from -= 4;
 	  n_left_to_next -= 4;

 	  b0 = vlib_get_buffer (vm, bi0);
 	  b1 = vlib_get_buffer (vm, bi1);
 	  b2 = vlib_get_buffer (vm, bi2);
 	  b3 = vlib_get_buffer (vm, bi3);
 	  ip0 = vlib_buffer_get_current (b0);
 	  ip1 = vlib_buffer_get_current (b1);
 	  ip2 = vlib_buffer_get_current (b2);
 	  ip3 = vlib_buffer_get_current (b2);

 	  vnet_feature_next (&next0, b0);
 	  vnet_feature_next (&next1, b1);
 	  vnet_feature_next (&next2, b2);
 	  vnet_feature_next (&next3, b3);

 	  if (ip0->protocol == IP_PROTOCOL_UDP)
 	    {
 	      udp0 = (udp_header_t *) (ip0 + 1);

 	      if (dhcp_client_port_network_order == udp0->dst_port)
 		{
 		  next0 = DHCP_CLIENT_DETECT_NEXT_EXTRACT;
 		  extractions++;
 		}
 	    }
 	  if (ip1->protocol == IP_PROTOCOL_UDP)
 	    {
 	      udp1 = (udp_header_t *) (ip1 + 1);

 	      if (dhcp_client_port_network_order == udp1->dst_port)
 		{
 		  next1 = DHCP_CLIENT_DETECT_NEXT_EXTRACT;
 		  extractions++;
 		}
 	    }
 	  if (ip2->protocol == IP_PROTOCOL_UDP)
 	    {
 	      udp2 = (udp_header_t *) (ip2 + 1);

 	      if (dhcp_client_port_network_order == udp2->dst_port)
 		{
 		  next2 = DHCP_CLIENT_DETECT_NEXT_EXTRACT;
 		  extractions++;
 		}
 	    }
 	  if (ip3->protocol == IP_PROTOCOL_UDP)
 	    {
 	      udp3 = (udp_header_t *) (ip3 + 1);

 	      if (dhcp_client_port_network_order == udp3->dst_port)
 		{
 		  next3 = DHCP_CLIENT_DETECT_NEXT_EXTRACT;
 		  extractions++;
 		}
 	    }

 	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 	    {
 	      dhcp_client_detect_trace_t *t =
 		vlib_add_trace (vm, node, b0, sizeof (*t));
 	      t->extracted = (next0 == DHCP_CLIENT_DETECT_NEXT_EXTRACT);
 	    }
 	  if (PREDICT_FALSE (b1->flags & VLIB_BUFFER_IS_TRACED))
 	    {
 	      dhcp_client_detect_trace_t *t =
 		vlib_add_trace (vm, node, b1, sizeof (*t));
 	      t->extracted = (next1 == DHCP_CLIENT_DETECT_NEXT_EXTRACT);
 	    }
 	  if (PREDICT_FALSE (b2->flags & VLIB_BUFFER_IS_TRACED))
 	    {
 	      dhcp_client_detect_trace_t *t =
 		vlib_add_trace (vm, node, b2, sizeof (*t));
 	      t->extracted = (next2 == DHCP_CLIENT_DETECT_NEXT_EXTRACT);
 	    }
 	  if (PREDICT_FALSE (b3->flags & VLIB_BUFFER_IS_TRACED))
 	    {
 	      dhcp_client_detect_trace_t *t =
 		vlib_add_trace (vm, node, b3, sizeof (*t));
 	      t->extracted = (next3 == DHCP_CLIENT_DETECT_NEXT_EXTRACT);
 	    }

 	  /* verify speculative enqueue, maybe switch current next frame */
 	  vlib_validate_buffer_enqueue_x4 (vm, node, next_index,
 					   to_next, n_left_to_next,
 					   bi0, bi1, bi2, bi3,
 					   next0, next1, next2, next3);
 	}

       while (n_left_from > 0 && n_left_to_next > 0)
 	{
 	  udp_header_t *udp0;
 	  vlib_buffer_t *b0;
 	  ip4_header_t *ip0;
 	  u32 next0 = ~0;
 	  u32 bi0;

 	  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);
 	  ip0 = vlib_buffer_get_current (b0);

 	  /*
 	   * when this feature is applied on an interface that is already
 	   * accepting packets (because e.g. the interface has other addresses
 	   * assigned) we are looking for the preverbial needle in the haystack
 	   * so assume the packet is not the one we are looking for.
 	   */
 	  vnet_feature_next (&next0, b0);

 	  /*
 	   * all we are looking for here is DHCP/BOOTP packet-to-client
 	   * UDO port.
 	   */
 	  if (ip0->protocol == IP_PROTOCOL_UDP)
 	    {
 	      udp0 = (udp_header_t *) (ip0 + 1);

 	      if (dhcp_client_port_network_order == udp0->dst_port)
 		{
 		  next0 = DHCP_CLIENT_DETECT_NEXT_EXTRACT;
 		  extractions++;
 		}
 	    }

 	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 	    {
 	      dhcp_client_detect_trace_t *t =
 		vlib_add_trace (vm, node, b0, sizeof (*t));
 	      t->extracted = (next0 == DHCP_CLIENT_DETECT_NEXT_EXTRACT);
 	    }

 	  /* verify speculative enqueue, maybe switch current next frame */
 	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 					   to_next, n_left_to_next,
 					   bi0, next0);
 	}

       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
     }

   vlib_node_increment_counter (vm, node->node_index,
 			       DHCP_CLIENT_DETECT_ERROR_EXTRACT, extractions);

   return frame->n_vectors;
 }

 /* packet trace format function */
 static u8 *
 format_dhcp_client_detect_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 *);
   dhcp_client_detect_trace_t *t =
     va_arg (*args, dhcp_client_detect_trace_t *);

   s = format (s, "dhcp-client-detect: %s", (t->extracted ? "yes" : "no"));

   return s;
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (dhcp_client_detect_node) = {
   .function = dhcp_client_detect_node_fn,
   .name = "ip4-dhcp-client-detect",
   .vector_size = sizeof (u32),
   .format_trace = format_dhcp_client_detect_trace,
   .type = VLIB_NODE_TYPE_INTERNAL,

   .n_errors = ARRAY_LEN(dhcp_client_detect_error_strings),
   .error_strings = dhcp_client_detect_error_strings,

   .n_next_nodes = DHCP_CLIENT_DETECT_N_NEXT,
   .next_nodes = {
     /*
      * Jump straight to the UDP dispatch node thus avoiding
      * the RPF checks in ip4-local that will fail
      */
     [DHCP_CLIENT_DETECT_NEXT_EXTRACT] = "ip4-udp-lookup",
   },
 };

 VLIB_NODE_FUNCTION_MULTIARCH (dhcp_client_detect_node,
                               dhcp_client_detect_node_fn);

 VNET_FEATURE_INIT (ip4_dvr_reinject_feat_node, static) =
 {
   .arc_name = "ip4-unicast",
   .node_name = "ip4-dhcp-client-detect",
   .runs_before = VNET_FEATURES ("ip4-not-enabled"),
 };

 /* *INDENT-ON* */

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* DHCP feature; applied as an input feature to select DHCP packets
	*
	* Copyright (c) 2013 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 <vnet/dhcp/client.h>
	#include <vnet/udp/udp.h>

	#define foreach_dhcp_client_detect \
	_(EXTRACT, "Extract")

	typedef enum
	{
	#define _(sym,str) DHCP_CLIENT_DETECT_ERROR_##sym,
	foreach_dhcp_client_detect
	#undef _
	DHCP_CLIENT_DETECT_N_ERROR,
	} dhcp_client_detect_error_t;

	static char *dhcp_client_detect_error_strings[] = {
	#define _(sym,string) string,
	foreach_dhcp_client_detect
	#undef _
	};

	typedef enum
	{
	#define _(sym,str) DHCP_CLIENT_DETECT_NEXT_##sym,
	foreach_dhcp_client_detect
	#undef _
	DHCP_CLIENT_DETECT_N_NEXT,
	} dhcp_client_detect_next_t;

	/**
	* per-packet trace data
	*/
	typedef struct dhcp_client_detect_trace_t_
	{
	/* per-pkt trace data */
	u8 extracted;
	} dhcp_client_detect_trace_t;

	static uword
	dhcp_client_detect_node_fn (vlib_main_t * vm,
	vlib_node_runtime_t * node, vlib_frame_t * frame)
	{
	dhcp_client_detect_next_t next_index;
	u16 dhcp_client_port_network_order;
	u32 n_left_from, from, to_next;
	u32 extractions;

	dhcp_client_port_network_order =
	clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_client);
	next_index = 0;
	extractions = 0;
	n_left_from = frame->n_vectors;
	from = vlib_frame_vector_args (frame);

	while (n_left_from > 0)
	{
	u32 n_left_to_next;

	vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

	/*
	* This loop is optimised not so we can really quickly process DHCp
	* offers... but so we can quickly sift them out when the interface
	* is also receving 'normal' packets
	*/
	while (n_left_from >= 8 && n_left_to_next >= 4)
	{
	udp_header_t udp0, udp1, udp2, udp3;
	ip4_header_t ip0, ip1, ip2, ip3;
	vlib_buffer_t b0, b1, b2, b3;
	u32 next0, next1, next2, next3;
	u32 bi0, bi1, bi2, bi3;

	next0 = next1 = next2 = next3 = ~0;
	bi0 = to_next[0] = from[0];
	bi1 = to_next[1] = from[1];
	bi2 = to_next[2] = from[2];
	bi3 = to_next[3] = from[3];

	/* Prefetch next iteration. */
	{
	vlib_buffer_t p2, p3, p4, p5;

	p2 = vlib_get_buffer (vm, from[2]);
	p3 = vlib_get_buffer (vm, from[3]);
	p4 = vlib_get_buffer (vm, from[4]);
	p5 = vlib_get_buffer (vm, from[5]);

	vlib_prefetch_buffer_header (p2, STORE);
	vlib_prefetch_buffer_header (p3, STORE);
	vlib_prefetch_buffer_header (p4, STORE);
	vlib_prefetch_buffer_header (p5, STORE);

	CLIB_PREFETCH (p2->data, sizeof (ip0[0]) + sizeof (udp0[0]),
	STORE);
	CLIB_PREFETCH (p3->data, sizeof (ip0[0]) + sizeof (udp0[0]),
	STORE);
	CLIB_PREFETCH (p4->data, sizeof (ip0[0]) + sizeof (udp0[0]),
	STORE);
	CLIB_PREFETCH (p5->data, sizeof (ip0[0]) + sizeof (udp0[0]),
	STORE);
	}

	from += 4;
	to_next += 4;
	n_left_from -= 4;
	n_left_to_next -= 4;

	b0 = vlib_get_buffer (vm, bi0);
	b1 = vlib_get_buffer (vm, bi1);
	b2 = vlib_get_buffer (vm, bi2);
	b3 = vlib_get_buffer (vm, bi3);
	ip0 = vlib_buffer_get_current (b0);
	ip1 = vlib_buffer_get_current (b1);
	ip2 = vlib_buffer_get_current (b2);
	ip3 = vlib_buffer_get_current (b2);

	vnet_feature_next (&next0, b0);
	vnet_feature_next (&next1, b1);
	vnet_feature_next (&next2, b2);
	vnet_feature_next (&next3, b3);

	if (ip0->protocol == IP_PROTOCOL_UDP)
	{
	udp0 = (udp_header_t *) (ip0 + 1);

	if (dhcp_client_port_network_order == udp0->dst_port)
	{
	next0 = DHCP_CLIENT_DETECT_NEXT_EXTRACT;
	extractions++;
	}
	}
	if (ip1->protocol == IP_PROTOCOL_UDP)
	{
	udp1 = (udp_header_t *) (ip1 + 1);

	if (dhcp_client_port_network_order == udp1->dst_port)
	{
	next1 = DHCP_CLIENT_DETECT_NEXT_EXTRACT;
	extractions++;
	}
	}
	if (ip2->protocol == IP_PROTOCOL_UDP)
	{
	udp2 = (udp_header_t *) (ip2 + 1);

	if (dhcp_client_port_network_order == udp2->dst_port)
	{
	next2 = DHCP_CLIENT_DETECT_NEXT_EXTRACT;
	extractions++;
	}
	}
	if (ip3->protocol == IP_PROTOCOL_UDP)
	{
	udp3 = (udp_header_t *) (ip3 + 1);

	if (dhcp_client_port_network_order == udp3->dst_port)
	{
	next3 = DHCP_CLIENT_DETECT_NEXT_EXTRACT;
	extractions++;
	}
	}

	if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
	{
	dhcp_client_detect_trace_t *t =
	vlib_add_trace (vm, node, b0, sizeof (*t));
	t->extracted = (next0 == DHCP_CLIENT_DETECT_NEXT_EXTRACT);
	}
	if (PREDICT_FALSE (b1->flags & VLIB_BUFFER_IS_TRACED))
	{
	dhcp_client_detect_trace_t *t =
	vlib_add_trace (vm, node, b1, sizeof (*t));
	t->extracted = (next1 == DHCP_CLIENT_DETECT_NEXT_EXTRACT);
	}
	if (PREDICT_FALSE (b2->flags & VLIB_BUFFER_IS_TRACED))
	{
	dhcp_client_detect_trace_t *t =
	vlib_add_trace (vm, node, b2, sizeof (*t));
	t->extracted = (next2 == DHCP_CLIENT_DETECT_NEXT_EXTRACT);
	}
	if (PREDICT_FALSE (b3->flags & VLIB_BUFFER_IS_TRACED))
	{
	dhcp_client_detect_trace_t *t =
	vlib_add_trace (vm, node, b3, sizeof (*t));
	t->extracted = (next3 == DHCP_CLIENT_DETECT_NEXT_EXTRACT);
	}

	/* verify speculative enqueue, maybe switch current next frame */
	vlib_validate_buffer_enqueue_x4 (vm, node, next_index,
	to_next, n_left_to_next,
	bi0, bi1, bi2, bi3,
	next0, next1, next2, next3);
	}

	while (n_left_from > 0 && n_left_to_next > 0)
	{
	udp_header_t *udp0;
	vlib_buffer_t *b0;
	ip4_header_t *ip0;
	u32 next0 = ~0;
	u32 bi0;

	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);
	ip0 = vlib_buffer_get_current (b0);

	/*
	* when this feature is applied on an interface that is already
	* accepting packets (because e.g. the interface has other addresses
	* assigned) we are looking for the preverbial needle in the haystack
	* so assume the packet is not the one we are looking for.
	*/
	vnet_feature_next (&next0, b0);

	/*
	* all we are looking for here is DHCP/BOOTP packet-to-client
	* UDO port.
	*/
	if (ip0->protocol == IP_PROTOCOL_UDP)
	{
	udp0 = (udp_header_t *) (ip0 + 1);

	if (dhcp_client_port_network_order == udp0->dst_port)
	{
	next0 = DHCP_CLIENT_DETECT_NEXT_EXTRACT;
	extractions++;
	}
	}

	if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
	{
	dhcp_client_detect_trace_t *t =
	vlib_add_trace (vm, node, b0, sizeof (*t));
	t->extracted = (next0 == DHCP_CLIENT_DETECT_NEXT_EXTRACT);
	}

	/* verify speculative enqueue, maybe switch current next frame */
	vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
	to_next, n_left_to_next,
	bi0, next0);
	}

	vlib_put_next_frame (vm, node, next_index, n_left_to_next);
	}

	vlib_node_increment_counter (vm, node->node_index,
	DHCP_CLIENT_DETECT_ERROR_EXTRACT, extractions);

	return frame->n_vectors;
	}

	/* packet trace format function */
	static u8 *
	format_dhcp_client_detect_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 );
	dhcp_client_detect_trace_t *t =
	va_arg (args, dhcp_client_detect_trace_t );

	s = format (s, "dhcp-client-detect: %s", (t->extracted ? "yes" : "no"));

	return s;
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (dhcp_client_detect_node) = {
	.function = dhcp_client_detect_node_fn,
	.name = "ip4-dhcp-client-detect",
	.vector_size = sizeof (u32),
	.format_trace = format_dhcp_client_detect_trace,
	.type = VLIB_NODE_TYPE_INTERNAL,

	.n_errors = ARRAY_LEN(dhcp_client_detect_error_strings),
	.error_strings = dhcp_client_detect_error_strings,

	.n_next_nodes = DHCP_CLIENT_DETECT_N_NEXT,
	.next_nodes = {
	/*
	* Jump straight to the UDP dispatch node thus avoiding
	* the RPF checks in ip4-local that will fail
	*/
	[DHCP_CLIENT_DETECT_NEXT_EXTRACT] = "ip4-udp-lookup",
	},
	};

	VLIB_NODE_FUNCTION_MULTIARCH (dhcp_client_detect_node,
	dhcp_client_detect_node_fn);

	VNET_FEATURE_INIT (ip4_dvr_reinject_feat_node, static) =
	{
	.arc_name = "ip4-unicast",
	.node_name = "ip4-dhcp-client-detect",
	.runs_before = VNET_FEATURES ("ip4-not-enabled"),
	};

	/* INDENT-ON */

	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/