dhcp4_proxy_node.c revision 02bfd641
1/*
2 * proxy_node.c: dhcp proxy node processing
3 *
4 * Copyright (c) 2013 Cisco and/or its affiliates.
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at:
8 *
9 *     http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18#include <vlib/vlib.h>
19#include <vnet/pg/pg.h>
20#include <dhcp/dhcp_proxy.h>
21#include <dhcp/client.h>
22#include <vnet/fib/ip4_fib.h>
23
24static char *dhcp_proxy_error_strings[] = {
25#define dhcp_proxy_error(n,s) s,
26#include <dhcp/dhcp4_proxy_error.def>
27#undef dhcp_proxy_error
28};
29
30#define foreach_dhcp_proxy_to_server_input_next \
31  _ (DROP, "error-drop")			\
32  _ (LOOKUP, "ip4-lookup")			\
33  _ (SEND_TO_CLIENT, "dhcp-proxy-to-client")
34
35typedef enum
36{
37#define _(s,n) DHCP_PROXY_TO_SERVER_INPUT_NEXT_##s,
38  foreach_dhcp_proxy_to_server_input_next
39#undef _
40    DHCP_PROXY_TO_SERVER_INPUT_N_NEXT,
41} dhcp_proxy_to_server_input_next_t;
42
43typedef struct
44{
45  /* 0 => to server, 1 => to client */
46  int which;
47  ip4_address_t trace_ip4_address;
48  u32 error;
49  u32 sw_if_index;
50  u32 original_sw_if_index;
51} dhcp_proxy_trace_t;
52
53#define VPP_DHCP_OPTION82_SUB1_SIZE   6
54#define VPP_DHCP_OPTION82_SUB5_SIZE   6
55#define VPP_DHCP_OPTION82_VSS_SIZE    12
56#define VPP_DHCP_OPTION82_SIZE (VPP_DHCP_OPTION82_SUB1_SIZE + \
57                                VPP_DHCP_OPTION82_SUB5_SIZE + \
58                                VPP_DHCP_OPTION82_VSS_SIZE +3)
59
60static vlib_node_registration_t dhcp_proxy_to_server_node;
61static vlib_node_registration_t dhcp_proxy_to_client_node;
62
63static u8 *
64format_dhcp_proxy_trace (u8 * s, va_list * args)
65{
66  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
67  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
68  dhcp_proxy_trace_t *t = va_arg (*args, dhcp_proxy_trace_t *);
69
70  if (t->which == 0)
71    s = format (s, "DHCP proxy: sent to server %U\n",
72		format_ip4_address, &t->trace_ip4_address, t->error);
73  else
74    s = format (s, "DHCP proxy: broadcast to client from %U\n",
75		format_ip4_address, &t->trace_ip4_address);
76
77  if (t->error != (u32) ~ 0)
78    s = format (s, "  error: %s\n", dhcp_proxy_error_strings[t->error]);
79
80  s = format (s, "  original_sw_if_index: %d, sw_if_index: %d\n",
81	      t->original_sw_if_index, t->sw_if_index);
82
83  return s;
84}
85
86static u8 *
87format_dhcp_proxy_header_with_length (u8 * s, va_list * args)
88{
89  dhcp_header_t *h = va_arg (*args, dhcp_header_t *);
90  u32 max_header_bytes = va_arg (*args, u32);
91  u32 header_bytes;
92
93  header_bytes = sizeof (h[0]);
94  if (max_header_bytes != 0 && header_bytes > max_header_bytes)
95    return format (s, "dhcp header truncated");
96
97  s = format (s, "DHCP Proxy");
98
99  return s;
100}
101
102static uword
103dhcp_proxy_to_server_input (vlib_main_t * vm,
104			    vlib_node_runtime_t * node,
105			    vlib_frame_t * from_frame)
106{
107  u32 n_left_from, next_index, *from, *to_next;
108  dhcp_proxy_main_t *dpm = &dhcp_proxy_main;
109  from = vlib_frame_vector_args (from_frame);
110  n_left_from = from_frame->n_vectors;
111  u32 pkts_to_server = 0, pkts_to_client = 0, pkts_no_server = 0;
112  u32 pkts_no_interface_address = 0;
113  u32 pkts_too_big = 0;
114  ip4_main_t *im = &ip4_main;
115
116  next_index = node->cached_next_index;
117
118  while (n_left_from > 0)
119    {
120      u32 n_left_to_next;
121
122      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
123
124      while (n_left_from > 0 && n_left_to_next > 0)
125	{
126	  u32 bi0;
127	  vlib_buffer_t *b0;
128	  udp_header_t *u0;
129	  dhcp_header_t *h0;
130	  ip4_header_t *ip0;
131	  u32 next0;
132	  u32 old0, new0;
133	  ip_csum_t sum0;
134	  u32 error0 = (u32) ~ 0;
135	  u32 sw_if_index = 0;
136	  u32 original_sw_if_index = 0;
137	  u32 fib_index;
138	  dhcp_proxy_t *proxy;
139	  dhcp_server_t *server;
140	  u32 rx_sw_if_index;
141	  dhcp_option_t *o, *end;
142	  u32 len = 0;
143	  u8 is_discover = 0;
144	  int space_left;
145
146	  bi0 = from[0];
147	  from += 1;
148	  n_left_from -= 1;
149
150	  b0 = vlib_get_buffer (vm, bi0);
151
152	  h0 = vlib_buffer_get_current (b0);
153
154	  /*
155	   * udp_local hands us the DHCP header, need udp hdr,
156	   * ip hdr to relay to server
157	   */
158	  vlib_buffer_advance (b0, -(sizeof (*u0)));
159	  u0 = vlib_buffer_get_current (b0);
160
161	  /* This blows. Return traffic has src_port = 67, dst_port = 67 */
162	  if (u0->src_port ==
163	      clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_server))
164	    {
165	      vlib_buffer_advance (b0, sizeof (*u0));
166	      next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_SEND_TO_CLIENT;
167	      error0 = 0;
168	      pkts_to_client++;
169	      goto do_enqueue;
170	    }
171
172	  rx_sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
173	  fib_index = im->fib_index_by_sw_if_index[rx_sw_if_index];
174	  proxy = dhcp_get_proxy (dpm, fib_index, FIB_PROTOCOL_IP4);
175
176	  if (PREDICT_FALSE (NULL == proxy))
177	    {
178	      error0 = DHCP_PROXY_ERROR_NO_SERVER;
179	      next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
180	      pkts_no_server++;
181	      goto do_trace;
182	    }
183
184	  if (!vlib_buffer_chain_linearize (vm, b0))
185	    {
186	      error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
187	      next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
188	      pkts_too_big++;
189	      goto do_trace;
190	    }
191	  space_left = vlib_buffer_space_left_at_end (vm, b0);
192	  /* cant parse chains...
193	   * and we need some space for option 82*/
194	  if ((b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0 ||
195	      space_left < VPP_DHCP_OPTION82_SIZE)
196	    {
197	      error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
198	      next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
199	      pkts_too_big++;
200	      goto do_trace;
201	    }
202
203	  server = &proxy->dhcp_servers[0];
204	  vlib_buffer_advance (b0, -(sizeof (*ip0)));
205	  ip0 = vlib_buffer_get_current (b0);
206
207	  /* disable UDP checksum */
208	  u0->checksum = 0;
209	  sum0 = ip0->checksum;
210	  old0 = ip0->dst_address.as_u32;
211	  new0 = server->dhcp_server.ip4.as_u32;
212	  ip0->dst_address.as_u32 = server->dhcp_server.ip4.as_u32;
213	  sum0 = ip_csum_update (sum0, old0, new0,
214				 ip4_header_t /* structure */ ,
215				 dst_address /* changed member */ );
216	  ip0->checksum = ip_csum_fold (sum0);
217
218	  sum0 = ip0->checksum;
219	  old0 = ip0->src_address.as_u32;
220	  new0 = proxy->dhcp_src_address.ip4.as_u32;
221	  ip0->src_address.as_u32 = new0;
222	  sum0 = ip_csum_update (sum0, old0, new0,
223				 ip4_header_t /* structure */ ,
224				 src_address /* changed member */ );
225	  ip0->checksum = ip_csum_fold (sum0);
226
227	  /* Send to DHCP server via the configured FIB */
228	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = server->server_fib_index;
229
230	  h0->gateway_ip_address = proxy->dhcp_src_address.ip4;
231	  pkts_to_server++;
232
233	  o = h0->options;
234	  end = (void *) vlib_buffer_get_tail (b0);
235
236	  /* TLVs are not performance-friendly... */
237	  while (o->option != DHCP_PACKET_OPTION_END && o < end)
238	    {
239	      if (DHCP_PACKET_OPTION_MSG_TYPE == o->option)
240		{
241		  if (DHCP_PACKET_DISCOVER == o->data[0])
242		    {
243		      is_discover = 1;
244		    }
245		}
246	      o = (dhcp_option_t *) (o->data + o->length);
247	    }
248
249	  if (o->option == DHCP_PACKET_OPTION_END && o <= end)
250	    {
251	      vnet_main_t *vnm = vnet_get_main ();
252	      u16 old_l0, new_l0;
253	      ip4_address_t _ia0, *ia0 = &_ia0;
254	      dhcp_vss_t *vss;
255	      vnet_sw_interface_t *swif;
256
257	      original_sw_if_index = sw_if_index =
258		vnet_buffer (b0)->sw_if_index[VLIB_RX];
259	      swif = vnet_get_sw_interface (vnm, sw_if_index);
260	      if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
261		sw_if_index = swif->unnumbered_sw_if_index;
262
263	      /*
264	       * Get the first ip4 address on the [client-side]
265	       * RX interface, if not unnumbered. otherwise use
266	       * the loopback interface's ip address.
267	       */
268	      ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
269
270	      if (ia0 == 0)
271		{
272		  error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
273		  next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
274		  pkts_no_interface_address++;
275		  goto do_trace;
276		}
277
278	      /* Add option 82 */
279	      o->option = 82;	/* option 82 */
280	      o->length = 12;	/* 12 octets to follow */
281	      o->data[0] = 1;	/* suboption 1, circuit ID (=FIB id) */
282	      o->data[1] = 4;	/* length of suboption */
283	      u32 *o_ifid = (u32 *) & o->data[2];
284	      *o_ifid = clib_host_to_net_u32 (original_sw_if_index);
285	      o->data[6] = 5;	/* suboption 5 (client RX intfc address) */
286	      o->data[7] = 4;	/* length 4 */
287	      u32 *o_addr = (u32 *) & o->data[8];
288	      *o_addr = ia0->as_u32;
289	      o->data[12] = DHCP_PACKET_OPTION_END;
290
291	      vss = dhcp_get_vss_info (dpm, fib_index, FIB_PROTOCOL_IP4);
292	      if (vss)
293		{
294		  u32 id_len;	/* length of VPN ID */
295
296		  if (vss->vss_type == VSS_TYPE_VPN_ID)
297		    {
298		      id_len = sizeof (vss->vpn_id);	/* vpn_id is 7 bytes */
299		      memcpy (&o->data[15], vss->vpn_id, id_len);
300		    }
301		  else if (vss->vss_type == VSS_TYPE_ASCII)
302		    {
303		      id_len = vec_len (vss->vpn_ascii_id);
304		      memcpy (&o->data[15], vss->vpn_ascii_id, id_len);
305		    }
306		  else		/* must be VSS_TYPE_DEFAULT, no VPN ID */
307		    id_len = 0;
308
309		  o->data[12] = 151;	/* vss suboption */
310		  o->data[13] = id_len + 1;	/* length: vss_type + id_len */
311		  o->data[14] = vss->vss_type;	/* vss option type */
312		  o->data[15 + id_len] = 152;	/* vss control suboption */
313		  o->data[16 + id_len] = 0;	/* length */
314		  o->data[17 + id_len] = DHCP_PACKET_OPTION_END;	/* "end-of-options" (0xFF) */
315		  /* 5 bytes for suboption headers 151+len, 152+len and 0xFF */
316		  o->length += id_len + 5;
317		}
318
319	      len = o->length + 3;
320	      b0->current_length += len;
321	      /* Fix IP header length and checksum */
322	      old_l0 = ip0->length;
323	      new_l0 = clib_net_to_host_u16 (old_l0);
324	      new_l0 += len;
325	      new_l0 = clib_host_to_net_u16 (new_l0);
326	      ip0->length = new_l0;
327	      sum0 = ip0->checksum;
328	      sum0 = ip_csum_update (sum0, old_l0, new_l0, ip4_header_t,
329				     length /* changed member */ );
330	      ip0->checksum = ip_csum_fold (sum0);
331
332	      /* Fix UDP length */
333	      new_l0 = clib_net_to_host_u16 (u0->length);
334	      new_l0 += len;
335	      u0->length = clib_host_to_net_u16 (new_l0);
336	    }
337	  else
338	    {
339	      vlib_node_increment_counter
340		(vm, dhcp_proxy_to_server_node.index,
341		 DHCP_PROXY_ERROR_OPTION_82_ERROR, 1);
342	    }
343
344	  next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP;
345
346	  /*
347	   * If we have multiple servers configured and this is the
348	   * client's discover message, then send copies to each of
349	   * those servers
350	   */
351	  if (is_discover && vec_len (proxy->dhcp_servers) > 1)
352	    {
353	      u32 ii;
354
355	      for (ii = 1; ii < vec_len (proxy->dhcp_servers); ii++)
356		{
357		  vlib_buffer_t *c0;
358		  u32 ci0;
359
360		  c0 = vlib_buffer_copy (vm, b0);
361		  VLIB_BUFFER_TRACE_TRAJECTORY_INIT (c0);
362		  ci0 = vlib_get_buffer_index (vm, c0);
363		  server = &proxy->dhcp_servers[ii];
364
365		  ip0 = vlib_buffer_get_current (c0);
366
367		  sum0 = ip0->checksum;
368		  old0 = ip0->dst_address.as_u32;
369		  new0 = server->dhcp_server.ip4.as_u32;
370		  ip0->dst_address.as_u32 = server->dhcp_server.ip4.as_u32;
371		  sum0 = ip_csum_update (sum0, old0, new0,
372					 ip4_header_t /* structure */ ,
373					 dst_address /* changed member */ );
374		  ip0->checksum = ip_csum_fold (sum0);
375
376		  to_next[0] = ci0;
377		  to_next += 1;
378		  n_left_to_next -= 1;
379
380		  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
381						   to_next, n_left_to_next,
382						   ci0, next0);
383
384		  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
385		    {
386		      dhcp_proxy_trace_t *tr;
387
388		      tr = vlib_add_trace (vm, node, c0, sizeof (*tr));
389		      tr->which = 0;	/* to server */
390		      tr->error = error0;
391		      tr->original_sw_if_index = original_sw_if_index;
392		      tr->sw_if_index = sw_if_index;
393		      if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
394			tr->trace_ip4_address.as_u32 =
395			  server->dhcp_server.ip4.as_u32;
396		    }
397
398		  if (PREDICT_FALSE (0 == n_left_to_next))
399		    {
400		      vlib_put_next_frame (vm, node, next_index,
401					   n_left_to_next);
402		      vlib_get_next_frame (vm, node, next_index,
403					   to_next, n_left_to_next);
404		    }
405		}
406	    }
407	do_trace:
408	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
409	    {
410	      dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
411						       b0, sizeof (*tr));
412	      tr->which = 0;	/* to server */
413	      tr->error = error0;
414	      tr->original_sw_if_index = original_sw_if_index;
415	      tr->sw_if_index = sw_if_index;
416	      if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
417		tr->trace_ip4_address.as_u32 =
418		  proxy->dhcp_servers[0].dhcp_server.ip4.as_u32;
419	    }
420
421	do_enqueue:
422	  to_next[0] = bi0;
423	  to_next += 1;
424	  n_left_to_next -= 1;
425
426	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
427					   to_next, n_left_to_next,
428					   bi0, next0);
429	}
430
431      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
432    }
433  vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
434			       DHCP_PROXY_ERROR_RELAY_TO_CLIENT,
435			       pkts_to_client);
436  vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
437			       DHCP_PROXY_ERROR_RELAY_TO_SERVER,
438			       pkts_to_server);
439  vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
440			       DHCP_PROXY_ERROR_NO_SERVER, pkts_no_server);
441  vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
442			       DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS,
443			       pkts_no_interface_address);
444  vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
445			       DHCP_PROXY_ERROR_PKT_TOO_BIG, pkts_too_big);
446  return from_frame->n_vectors;
447}
448
449/* *INDENT-OFF* */
450VLIB_REGISTER_NODE (dhcp_proxy_to_server_node, static) = {
451  .function = dhcp_proxy_to_server_input,
452  .name = "dhcp-proxy-to-server",
453  /* Takes a vector of packets. */
454  .vector_size = sizeof (u32),
455
456  .n_errors = DHCP_PROXY_N_ERROR,
457  .error_strings = dhcp_proxy_error_strings,
458
459  .n_next_nodes = DHCP_PROXY_TO_SERVER_INPUT_N_NEXT,
460  .next_nodes = {
461#define _(s,n) [DHCP_PROXY_TO_SERVER_INPUT_NEXT_##s] = n,
462    foreach_dhcp_proxy_to_server_input_next
463#undef _
464  },
465
466  .format_buffer = format_dhcp_proxy_header_with_length,
467  .format_trace = format_dhcp_proxy_trace,
468#if 0
469  .unformat_buffer = unformat_dhcp_proxy_header,
470#endif
471};
472/* *INDENT-ON* */
473
474static uword
475dhcp_proxy_to_client_input (vlib_main_t * vm,
476			    vlib_node_runtime_t * node,
477			    vlib_frame_t * from_frame)
478{
479  u32 n_left_from, *from;
480  ethernet_main_t *em = vnet_get_ethernet_main ();
481  dhcp_proxy_main_t *dpm = &dhcp_proxy_main;
482  vnet_main_t *vnm = vnet_get_main ();
483  ip4_main_t *im = &ip4_main;
484
485  from = vlib_frame_vector_args (from_frame);
486  n_left_from = from_frame->n_vectors;
487
488  while (n_left_from > 0)
489    {
490      u32 bi0;
491      vlib_buffer_t *b0;
492      udp_header_t *u0;
493      dhcp_header_t *h0;
494      ip4_header_t *ip0 = 0;
495      ip4_address_t *ia0 = 0;
496      u32 old0, new0;
497      ip_csum_t sum0;
498      ethernet_interface_t *ei0;
499      ethernet_header_t *mac0;
500      vnet_hw_interface_t *hi0;
501      vlib_frame_t *f0;
502      u32 *to_next0;
503      u32 sw_if_index = ~0;
504      vnet_sw_interface_t *si0;
505      u32 error0 = (u32) ~ 0;
506      vnet_sw_interface_t *swif;
507      u32 fib_index;
508      dhcp_proxy_t *proxy;
509      dhcp_server_t *server;
510      u32 original_sw_if_index = (u32) ~ 0;
511      ip4_address_t relay_addr = {
512	.as_u32 = 0,
513      };
514
515      bi0 = from[0];
516      from += 1;
517      n_left_from -= 1;
518
519      b0 = vlib_get_buffer (vm, bi0);
520      h0 = vlib_buffer_get_current (b0);
521
522      /*
523       * udp_local hands us the DHCP header, need udp hdr,
524       * ip hdr to relay to client
525       */
526      vlib_buffer_advance (b0, -(sizeof (*u0)));
527      u0 = vlib_buffer_get_current (b0);
528
529      vlib_buffer_advance (b0, -(sizeof (*ip0)));
530      ip0 = vlib_buffer_get_current (b0);
531
532      /* Consumed by dhcp client code? */
533      if (dhcp_client_for_us (bi0, b0, ip0, u0, h0))
534	continue;
535
536      if (1 /* dpm->insert_option_82 */ )
537	{
538	  /* linearize needed to "unclone" and scan options */
539	  int rv = vlib_buffer_chain_linearize (vm, b0);
540	  if ((b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0 || !rv)
541	    {
542	      error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
543	      goto drop_packet;
544	    }
545
546	  dhcp_option_t *o = h0->options, *end =
547	    (void *) vlib_buffer_get_tail (b0);
548
549	  /* Parse through TLVs looking for option 82.
550	     The circuit-ID is the FIB number we need
551	     to track down the client-facing interface */
552
553	  while (o->option != DHCP_PACKET_OPTION_END && o < end)
554	    {
555	      if (o->option == 82)
556		{
557		  u32 vss_exist = 0;
558		  u32 vss_ctrl = 0;
559		  dhcp_option_t *sub = (dhcp_option_t *) & o->data[0];
560		  dhcp_option_t *subend =
561		    (dhcp_option_t *) (o->data + o->length);
562		  while (sub->option != DHCP_PACKET_OPTION_END
563			 && sub < subend)
564		    {
565		      /* If this is one of ours, it will have
566		         total length 12, circuit-id suboption type,
567		         and the sw_if_index */
568		      if (sub->option == 1 && sub->length == 4)
569			{
570			  sw_if_index = ((sub->data[0] << 24) |
571					 (sub->data[1] << 16) |
572					 (sub->data[2] << 8) |
573					 (sub->data[3]));
574			}
575		      else if (sub->option == 5 && sub->length == 4)
576			{
577			  relay_addr.as_u8[0] = sub->data[0];
578			  relay_addr.as_u8[1] = sub->data[1];
579			  relay_addr.as_u8[2] = sub->data[2];
580			  relay_addr.as_u8[3] = sub->data[3];
581			}
582		      else if (sub->option == 151 &&
583			       sub->length == 7 && sub->data[0] == 1)
584			vss_exist = 1;
585		      else if (sub->option == 152 && sub->length == 0)
586			vss_ctrl = 1;
587		      sub = (dhcp_option_t *) (sub->data + sub->length);
588		    }
589		  if (vss_ctrl && vss_exist)
590		    vlib_node_increment_counter
591		      (vm, dhcp_proxy_to_client_node.index,
592		       DHCP_PROXY_ERROR_OPTION_82_VSS_NOT_PROCESSED, 1);
593
594		}
595	      o = (dhcp_option_t *) (o->data + o->length);
596	    }
597	}
598
599      if (sw_if_index == (u32) ~ 0)
600	{
601	  error0 = DHCP_PROXY_ERROR_NO_OPTION_82;
602
603	drop_packet:
604	  vlib_node_increment_counter (vm, dhcp_proxy_to_client_node.index,
605				       error0, 1);
606	  f0 = vlib_get_frame_to_node (vm, dpm->error_drop_node_index);
607	  to_next0 = vlib_frame_vector_args (f0);
608	  to_next0[0] = bi0;
609	  f0->n_vectors = 1;
610	  vlib_put_frame_to_node (vm, dpm->error_drop_node_index, f0);
611	  goto do_trace;
612	}
613
614      if (relay_addr.as_u32 == 0)
615	{
616	  error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ADDR;
617	  goto drop_packet;
618	}
619
620      if (sw_if_index >= vec_len (im->fib_index_by_sw_if_index))
621	{
622	  error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ITF;
623	  goto drop_packet;
624	}
625
626      fib_index = im->fib_index_by_sw_if_index[sw_if_index];
627      proxy = dhcp_get_proxy (dpm, fib_index, FIB_PROTOCOL_IP4);
628
629      if (PREDICT_FALSE (NULL == proxy))
630	{
631	  error0 = DHCP_PROXY_ERROR_NO_SERVER;
632	  goto drop_packet;
633	}
634
635      vec_foreach (server, proxy->dhcp_servers)
636      {
637	if (ip0->src_address.as_u32 == server->dhcp_server.ip4.as_u32)
638	  {
639	    goto server_found;
640	  }
641      }
642
643      error0 = DHCP_PROXY_ERROR_BAD_SVR_FIB_OR_ADDRESS;
644      goto drop_packet;
645
646    server_found:
647      vnet_buffer (b0)->sw_if_index[VLIB_TX] = sw_if_index;
648
649      swif = vnet_get_sw_interface (vnm, sw_if_index);
650      original_sw_if_index = sw_if_index;
651      if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
652	sw_if_index = swif->unnumbered_sw_if_index;
653
654      ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
655      if (ia0 == 0)
656	{
657	  error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
658	  goto drop_packet;
659	}
660
661      if (relay_addr.as_u32 != ia0->as_u32)
662	{
663	  error0 = DHCP_PROXY_ERROR_BAD_YIADDR;
664	  goto drop_packet;
665	}
666
667      u0->checksum = 0;
668      u0->dst_port = clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_client);
669      sum0 = ip0->checksum;
670      old0 = ip0->dst_address.as_u32;
671      new0 = 0xFFFFFFFF;
672      ip0->dst_address.as_u32 = new0;
673      sum0 = ip_csum_update (sum0, old0, new0, ip4_header_t /* structure */ ,
674			     dst_address /* offset of changed member */ );
675      ip0->checksum = ip_csum_fold (sum0);
676
677      sum0 = ip0->checksum;
678      old0 = ip0->src_address.as_u32;
679      new0 = ia0->as_u32;
680      ip0->src_address.as_u32 = new0;
681      sum0 = ip_csum_update (sum0, old0, new0, ip4_header_t /* structure */ ,
682			     src_address /* offset of changed member */ );
683      ip0->checksum = ip_csum_fold (sum0);
684
685      vlib_buffer_advance (b0, -(sizeof (ethernet_header_t)));
686      si0 = vnet_get_sw_interface (vnm, original_sw_if_index);
687      if (si0->type == VNET_SW_INTERFACE_TYPE_SUB)
688	vlib_buffer_advance (b0, -4 /* space for VLAN tag */ );
689
690      mac0 = vlib_buffer_get_current (b0);
691
692      hi0 = vnet_get_sup_hw_interface (vnm, original_sw_if_index);
693      ei0 = pool_elt_at_index (em->interfaces, hi0->hw_instance);
694      clib_memcpy (mac0->src_address, ei0->address, sizeof (ei0->address));
695      clib_memset (mac0->dst_address, 0xff, sizeof (mac0->dst_address));
696      mac0->type = (si0->type == VNET_SW_INTERFACE_TYPE_SUB) ?
697	clib_net_to_host_u16 (0x8100) : clib_net_to_host_u16 (0x0800);
698
699      if (si0->type == VNET_SW_INTERFACE_TYPE_SUB)
700	{
701	  u32 *vlan_tag = (u32 *) (mac0 + 1);
702	  u32 tmp;
703	  tmp = (si0->sub.id << 16) | 0x0800;
704	  *vlan_tag = clib_host_to_net_u32 (tmp);
705	}
706
707      /* $$$ This needs to be rewritten, for sure */
708      f0 = vlib_get_frame_to_node (vm, hi0->output_node_index);
709      to_next0 = vlib_frame_vector_args (f0);
710      to_next0[0] = bi0;
711      f0->n_vectors = 1;
712      vlib_put_frame_to_node (vm, hi0->output_node_index, f0);
713
714    do_trace:
715      if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
716	{
717	  dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
718						   b0, sizeof (*tr));
719	  tr->which = 1;	/* to client */
720	  tr->trace_ip4_address.as_u32 = ia0 ? ia0->as_u32 : 0;
721	  tr->error = error0;
722	  tr->original_sw_if_index = original_sw_if_index;
723	  tr->sw_if_index = sw_if_index;
724	}
725    }
726
727  return from_frame->n_vectors;
728}
729
730/* *INDENT-OFF* */
731VLIB_REGISTER_NODE (dhcp_proxy_to_client_node, static) = {
732  .function = dhcp_proxy_to_client_input,
733  .name = "dhcp-proxy-to-client",
734  /* Takes a vector of packets. */
735  .vector_size = sizeof (u32),
736
737  .n_errors = DHCP_PROXY_N_ERROR,
738  .error_strings = dhcp_proxy_error_strings,
739  .format_buffer = format_dhcp_proxy_header_with_length,
740  .format_trace = format_dhcp_proxy_trace,
741#if 0
742  .unformat_buffer = unformat_dhcp_proxy_header,
743#endif
744};
745/* *INDENT-ON* */
746
747void
748dhcp_maybe_register_udp_ports (dhcp_port_reg_flags_t ports)
749{
750  dhcp_proxy_main_t *dm = &dhcp_proxy_main;
751  vlib_main_t *vm = dm->vlib_main;
752  int port_regs_diff = dm->udp_ports_registered ^ ports;
753
754  if (!port_regs_diff)
755    return;
756
757  if ((port_regs_diff & DHCP_PORT_REG_CLIENT) & ports)
758    udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_client,
759			   dhcp_proxy_to_client_node.index, 1 /* is_ip4 */ );
760
761  if ((port_regs_diff & DHCP_PORT_REG_SERVER) & ports)
762    udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_server,
763			   dhcp_proxy_to_server_node.index, 1 /* is_ip4 */ );
764
765  dm->udp_ports_registered |= ports;
766}
767
768static clib_error_t *
769dhcp4_proxy_init (vlib_main_t * vm)
770{
771  dhcp_proxy_main_t *dm = &dhcp_proxy_main;
772  vlib_node_t *error_drop_node;
773
774  error_drop_node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
775  dm->error_drop_node_index = error_drop_node->index;
776  dm->vlib_main = vm;
777
778  return 0;
779}
780
781
782VLIB_INIT_FUNCTION (dhcp4_proxy_init);
783
784int
785dhcp4_proxy_set_server (ip46_address_t * addr,
786			ip46_address_t * src_addr,
787			u32 rx_table_id, u32 server_table_id, int is_del)
788{
789  u32 rx_fib_index = 0;
790  int rc = 0;
791
792  const fib_prefix_t all_1s = {
793    .fp_len = 32,
794    .fp_addr.ip4.as_u32 = 0xffffffff,
795    .fp_proto = FIB_PROTOCOL_IP4,
796  };
797
798  if (ip46_address_is_zero (addr))
799    return VNET_API_ERROR_INVALID_DST_ADDRESS;
800
801  if (ip46_address_is_zero (src_addr))
802    return VNET_API_ERROR_INVALID_SRC_ADDRESS;
803
804  dhcp_maybe_register_udp_ports (DHCP_PORT_REG_CLIENT | DHCP_PORT_REG_SERVER);
805
806  rx_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
807						    rx_table_id,
808						    FIB_SOURCE_DHCP);
809
810  if (is_del)
811    {
812      if (dhcp_proxy_server_del (FIB_PROTOCOL_IP4, rx_fib_index,
813				 addr, server_table_id))
814	{
815	  fib_table_entry_special_remove (rx_fib_index,
816					  &all_1s, FIB_SOURCE_DHCP);
817	  fib_table_unlock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
818	}
819    }
820  else
821    {
822      if (dhcp_proxy_server_add (FIB_PROTOCOL_IP4,
823				 addr, src_addr,
824				 rx_fib_index, server_table_id))
825	{
826	  fib_table_entry_special_add (rx_fib_index,
827				       &all_1s,
828				       FIB_SOURCE_DHCP, FIB_ENTRY_FLAG_LOCAL);
829	  fib_table_lock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
830	}
831    }
832  fib_table_unlock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
833
834  return (rc);
835}
836
837static clib_error_t *
838dhcp4_proxy_set_command_fn (vlib_main_t * vm,
839			    unformat_input_t * input,
840			    vlib_cli_command_t * cmd)
841{
842  ip46_address_t server_addr, src_addr;
843  u32 server_table_id = 0, rx_table_id = 0;
844  int is_del = 0;
845  int set_src = 0, set_server = 0;
846
847  clib_memset (&server_addr, 0, sizeof (server_addr));
848  clib_memset (&src_addr, 0, sizeof (src_addr));
849
850  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
851    {
852      if (unformat (input, "server %U",
853		    unformat_ip4_address, &server_addr.ip4))
854	set_server = 1;
855      else if (unformat (input, "server-fib-id %d", &server_table_id))
856	;
857      else if (unformat (input, "rx-fib-id %d", &rx_table_id))
858	;
859      else if (unformat (input, "src-address %U",
860			 unformat_ip4_address, &src_addr.ip4))
861	set_src = 1;
862      else if (unformat (input, "delete") || unformat (input, "del"))
863	is_del = 1;
864      else
865	break;
866    }
867
868  if (is_del || (set_server && set_src))
869    {
870      int rv;
871
872      rv = dhcp4_proxy_set_server (&server_addr, &src_addr, rx_table_id,
873				   server_table_id, is_del);
874      switch (rv)
875	{
876	case 0:
877	  return 0;
878
879	case VNET_API_ERROR_INVALID_DST_ADDRESS:
880	  return clib_error_return (0, "Invalid server address");
881
882	case VNET_API_ERROR_INVALID_SRC_ADDRESS:
883	  return clib_error_return (0, "Invalid src address");
884
885	case VNET_API_ERROR_NO_SUCH_ENTRY:
886	  return clib_error_return
887	    (0, "Fib id %d: no per-fib DHCP server configured", rx_table_id);
888
889	default:
890	  return clib_error_return (0, "BUG: rv %d", rv);
891	}
892    }
893  else
894    return clib_error_return (0, "parse error`%U'",
895			      format_unformat_error, input);
896}
897
898/* *INDENT-OFF* */
899VLIB_CLI_COMMAND (dhcp_proxy_set_command, static) = {
900  .path = "set dhcp proxy",
901  .short_help = "set dhcp proxy [del] server <ip-addr> src-address <ip-addr> [server-fib-id <n>] [rx-fib-id <n>]",
902  .function = dhcp4_proxy_set_command_fn,
903};
904/* *INDENT-ON* */
905
906static u8 *
907format_dhcp4_proxy_server (u8 * s, va_list * args)
908{
909  dhcp_proxy_t *proxy = va_arg (*args, dhcp_proxy_t *);
910  ip4_fib_t *rx_fib, *server_fib;
911  dhcp_server_t *server;
912
913  if (proxy == 0)
914    {
915      s = format (s, "%=14s%=16s%s", "RX FIB", "Src Address",
916		  "Servers FIB,Address");
917      return s;
918    }
919
920  rx_fib = ip4_fib_get (proxy->rx_fib_index);
921
922  s = format (s, "%=14u%=16U",
923	      rx_fib->table_id,
924	      format_ip46_address, &proxy->dhcp_src_address, IP46_TYPE_ANY);
925
926  vec_foreach (server, proxy->dhcp_servers)
927  {
928    server_fib = ip4_fib_get (server->server_fib_index);
929    s = format (s, "%u,%U  ",
930		server_fib->table_id,
931		format_ip46_address, &server->dhcp_server, IP46_TYPE_ANY);
932  }
933  return s;
934}
935
936static int
937dhcp4_proxy_show_walk (dhcp_proxy_t * server, void *ctx)
938{
939  vlib_main_t *vm = ctx;
940
941  vlib_cli_output (vm, "%U", format_dhcp4_proxy_server, server);
942
943  return (1);
944}
945
946static clib_error_t *
947dhcp4_proxy_show_command_fn (vlib_main_t * vm,
948			     unformat_input_t * input,
949			     vlib_cli_command_t * cmd)
950{
951  vlib_cli_output (vm, "%U", format_dhcp4_proxy_server,
952		   NULL /* header line */ );
953
954  dhcp_proxy_walk (FIB_PROTOCOL_IP4, dhcp4_proxy_show_walk, vm);
955
956  return (NULL);
957}
958
959/* *INDENT-OFF* */
960VLIB_CLI_COMMAND (dhcp_proxy_show_command, static) = {
961  .path = "show dhcp proxy",
962  .short_help = "Display dhcp proxy server info",
963  .function = dhcp4_proxy_show_command_fn,
964};
965/* *INDENT-ON* */
966
967static clib_error_t *
968dhcp_option_82_vss_fn (vlib_main_t * vm,
969		       unformat_input_t * input, vlib_cli_command_t * cmd)
970{
971  u8 is_del = 0, vss_type = VSS_TYPE_DEFAULT;
972  u32 oui = 0, fib_id = 0, tbl_id = ~0;
973  u8 *vpn_ascii_id = 0;
974
975  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
976    {
977      if (unformat (input, "table %d", &tbl_id))
978	;
979      else if (unformat (input, "oui %d", &oui))
980	vss_type = VSS_TYPE_VPN_ID;
981      else if (unformat (input, "vpn-id %d", &fib_id))
982	vss_type = VSS_TYPE_VPN_ID;
983      else if (unformat (input, "vpn-ascii-id %s", &vpn_ascii_id))
984	vss_type = VSS_TYPE_ASCII;
985      else if (unformat (input, "delete") || unformat (input, "del"))
986	is_del = 1;
987      else
988	break;
989    }
990
991  if (tbl_id == ~0)
992    return clib_error_return (0, "no table ID specified.");
993
994  int rv = dhcp_proxy_set_vss (FIB_PROTOCOL_IP4, tbl_id, vss_type,
995			       vpn_ascii_id, oui, fib_id, is_del);
996  switch (rv)
997    {
998    case 0:
999      return 0;
1000    case VNET_API_ERROR_NO_SUCH_ENTRY:
1001      return clib_error_return (0,
1002				"option 82 vss for table %d not found in in pool.",
1003				tbl_id);
1004    default:
1005      return clib_error_return (0, "BUG: rv %d", rv);
1006
1007    }
1008}
1009
1010/* *INDENT-OFF* */
1011VLIB_CLI_COMMAND (dhcp_proxy_vss_command,static) = {
1012  .path = "set dhcp option-82 vss",
1013  .short_help = "set dhcp option-82 vss [del] table <table id> [oui <n> vpn-id <n> | vpn-ascii-id <text>]",
1014  .function = dhcp_option_82_vss_fn,
1015};
1016/* *INDENT-ON* */
1017
1018static clib_error_t *
1019dhcp_vss_show_command_fn (vlib_main_t * vm,
1020			  unformat_input_t * input, vlib_cli_command_t * cmd)
1021{
1022  dhcp_vss_walk (FIB_PROTOCOL_IP4, dhcp_vss_show_walk, vm);
1023
1024  return (NULL);
1025}
1026
1027/* *INDENT-OFF* */
1028VLIB_CLI_COMMAND (dhcp_proxy_vss_show_command, static) = {
1029  .path = "show dhcp vss",
1030  .short_help = "show dhcp VSS",
1031  .function = dhcp_vss_show_command_fn,
1032};
1033/* *INDENT-ON* */
1034
1035static clib_error_t *
1036dhcp_option_82_address_show_command_fn (vlib_main_t * vm,
1037					unformat_input_t * input,
1038					vlib_cli_command_t * cmd)
1039{
1040  vnet_main_t *vnm = vnet_get_main ();
1041  u32 sw_if_index0 = 0, sw_if_index;
1042  vnet_sw_interface_t *swif;
1043  ip4_address_t *ia0;
1044
1045  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1046    {
1047
1048      if (unformat (input, "%U",
1049		    unformat_vnet_sw_interface, vnm, &sw_if_index0))
1050	{
1051	  swif = vnet_get_sw_interface (vnm, sw_if_index0);
1052	  sw_if_index = (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED) ?
1053	    swif->unnumbered_sw_if_index : sw_if_index0;
1054	  ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
1055	  if (ia0)
1056	    {
1057	      vlib_cli_output (vm, "%=20s%=20s", "interface",
1058			       "source IP address");
1059
1060	      vlib_cli_output (vm, "%=20U%=20U",
1061			       format_vnet_sw_if_index_name,
1062			       vnm, sw_if_index0, format_ip4_address, ia0);
1063	    }
1064	  else
1065	    vlib_cli_output (vm, "%=34s %=20U",
1066			     "No IPv4 address configured on",
1067			     format_vnet_sw_if_index_name, vnm, sw_if_index);
1068	}
1069      else
1070	break;
1071    }
1072
1073  return 0;
1074}
1075
1076/* *INDENT-OFF* */
1077VLIB_CLI_COMMAND (dhcp_proxy_address_show_command,static) = {
1078  .path = "show dhcp option-82-address interface",
1079  .short_help = "show dhcp option-82-address interface <interface>",
1080  .function = dhcp_option_82_address_show_command_fn,
1081};
1082/* *INDENT-ON* */
1083
1084/*
1085 * fd.io coding-style-patch-verification: ON
1086 *
1087 * Local Variables:
1088 * eval: (c-set-style "gnu")
1089 * End:
1090 */
1091