1/*
2 * Copyright (c) 2011-2016 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
6 *
7 *     http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15/**
16 * @file
17 * @brief LLDP nodes implementation
18 */
19#include <vnet/lldp/lldp_node.h>
20#include <vnet/ethernet/ethernet.h>
21#include <vnet/ethernet/packet.h>
22
23/* set this to 1 to turn on debug prints via clib_warning() */
24#define LLDP_DEBUG (0)
25
26static vlib_node_registration_t lldp_process_node;
27
28#define F(sym, string) static char LLDP_ERR_##sym##_STR[] = string;
29foreach_lldp_error (F);
30#undef F
31
32/*
33 * packet counter strings
34 * Dump these counters via the "show error" CLI command
35 */
36static char *lldp_error_strings[] = {
37#define F(sym, string) LLDP_ERR_##sym##_STR,
38  foreach_lldp_error (F)
39#undef F
40};
41
42/*
43 * We actually send all lldp pkts to the "error" node after scanning
44 * them, so the graph node has only one next-index. The "error-drop"
45 * node automatically bumps our per-node packet counters for us.
46 */
47typedef enum
48{
49  LLDP_INPUT_NEXT_NORMAL,
50  LLDP_INPUT_N_NEXT,
51} lldp_next_t;
52
53/*
54 * Process a frame of lldp packets
55 * Expect 1 packet / frame
56 */
57static uword
58lldp_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
59	      vlib_frame_t * frame)
60{
61  u32 n_left_from, *from;
62  lldp_input_trace_t *t0;
63
64  from = vlib_frame_vector_args (frame);	/* array of buffer indices */
65  n_left_from = frame->n_vectors;	/* number of buffer indices */
66
67  while (n_left_from > 0)
68    {
69      u32 bi0;
70      vlib_buffer_t *b0;
71      u32 next0, error0;
72
73      bi0 = from[0];
74      b0 = vlib_get_buffer (vm, bi0);
75
76      next0 = LLDP_INPUT_NEXT_NORMAL;
77
78      /* scan this lldp pkt. error0 is the counter index to bump */
79      error0 = lldp_input (vm, b0, bi0);
80      b0->error = node->errors[error0];
81
82      /* If this pkt is traced, snapshot the data */
83      if (b0->flags & VLIB_BUFFER_IS_TRACED)
84	{
85	  int len;
86	  t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
87	  len = (b0->current_length < sizeof (t0->data)) ? b0->current_length
88	    : sizeof (t0->data);
89	  t0->len = len;
90	  clib_memcpy_fast (t0->data, vlib_buffer_get_current (b0), len);
91	}
92      /* push this pkt to the next graph node, always error-drop */
93      vlib_set_next_frame_buffer (vm, node, next0, bi0);
94
95      from += 1;
96      n_left_from -= 1;
97    }
98
99  return frame->n_vectors;
100}
101
102/*
103 * lldp input graph node declaration
104 */
105/* *INDENT-OFF* */
106VLIB_REGISTER_NODE(lldp_input_node, static) = {
107  .function = lldp_node_fn,
108  .name = "lldp-input",
109  .vector_size = sizeof(u32),
110  .type = VLIB_NODE_TYPE_INTERNAL,
111
112  .n_errors = LLDP_N_ERROR,
113  .error_strings = lldp_error_strings,
114
115  .format_trace = lldp_input_format_trace,
116
117  .n_next_nodes = LLDP_INPUT_N_NEXT,
118  .next_nodes =
119      {
120              [LLDP_INPUT_NEXT_NORMAL] = "error-drop",
121      },
122};
123/* *INDENT-ON* */
124
125/*
126 * lldp process node function
127 */
128static uword
129lldp_process (vlib_main_t * vm, vlib_node_runtime_t * rt, vlib_frame_t * f)
130{
131  lldp_main_t *lm = &lldp_main;
132  f64 timeout = 0;
133  uword event_type, *event_data = 0;
134
135  /* So we can send events to the lldp process */
136  lm->lldp_process_node_index = lldp_process_node.index;
137
138  /* with ethernet input */
139  ethernet_register_input_type (vm, ETHERNET_TYPE_802_1_LLDP /* LLDP */ ,
140				lldp_input_node.index);
141
142  while (1)
143    {
144      if (vec_len (lm->intfs_timeouts))
145	{
146#if LLDP_DEBUG
147	  clib_warning ("DEBUG: wait for event with timeout %f", timeout);
148#endif
149	  (void) vlib_process_wait_for_event_or_clock (vm, timeout);
150	}
151      else
152	{
153#if LLDP_DEBUG
154	  clib_warning ("DEBUG: wait for event without timeout");
155#endif
156	  (void) vlib_process_wait_for_event (vm);
157	}
158      event_type = vlib_process_get_events (vm, &event_data);
159      switch (event_type)
160	{
161	case ~0:		/* no events => timeout */
162	  /* nothing to do here */
163	  break;
164	case LLDP_EVENT_RESCHEDULE:
165	  /* nothing to do here - reschedule is done automatically after
166	   * each event or timeout */
167	  break;
168	default:
169	  clib_warning ("BUG: event type 0x%wx", event_type);
170	  break;
171	}
172      if (!vec_len (lm->intfs_timeouts))
173	{
174	  continue;
175	}
176      /* send packet(s) and schedule another timeout */
177      const f64 now = vlib_time_now (lm->vlib_main);
178      while (1)
179	{
180	  lldp_intf_t *n = pool_elt_at_index (lm->intfs,
181					      lm->intfs_timeouts
182					      [lm->intfs_timeouts_idx]);
183	  if (n->last_sent < 0.01 || now > n->last_sent + lm->msg_tx_interval)
184	    {
185#if LLDP_DEBUG
186	      clib_warning ("send packet to lldp %p, if idx %d", n,
187			    n->hw_if_index);
188#endif
189	      lldp_send_ethernet (lm, n, 0);
190	      ++lm->intfs_timeouts_idx;
191	      if (lm->intfs_timeouts_idx >= vec_len (lm->intfs_timeouts))
192		{
193		  lm->intfs_timeouts_idx = 0;
194		}
195	      continue;
196	    }
197	  else
198	    {
199	      timeout = n->last_sent + lm->msg_tx_interval - now;
200	      break;
201	    }
202	}
203#if LLDP_DEBUG
204      clib_warning ("DEBUG: timeout set to %f", timeout);
205      u8 *s = NULL;
206      u32 i;
207      vec_foreach_index (i, lm->intfs_timeouts)
208      {
209	if (i == lm->intfs_timeouts_idx)
210	  {
211	    s = format (s, " [%d]", lm->intfs_timeouts[i]);
212	  }
213	else
214	  {
215	    s = format (s, " %d", lm->intfs_timeouts[i]);
216	  }
217      }
218      clib_warning ("DEBUG: timeout schedule: %s", s);
219      vec_free (s);
220#endif
221      if (event_data)
222	{
223	  _vec_len (event_data) = 0;
224	}
225    }
226
227  return 0;
228}
229
230/*
231 * lldp process node declaration
232 */
233/* *INDENT-OFF* */
234VLIB_REGISTER_NODE(lldp_process_node, static) = {
235  .function = lldp_process,
236  .type = VLIB_NODE_TYPE_PROCESS,
237  .name = "lldp-process",
238};
239/* *INDENT-ON* */
240
241void
242lldp_schedule_intf (lldp_main_t * lm, lldp_intf_t * n)
243{
244  const int idx = n - lm->intfs;
245  u32 v;
246  vec_foreach_index (v, lm->intfs_timeouts)
247  {
248    if (lm->intfs_timeouts[v] == idx)
249      {
250	/* already scheduled */
251	return;
252      }
253  }
254  n->last_sent = 0;		/* ensure that a packet is sent out immediately */
255  /* put the interface at the current position in the timeouts - it
256   * will timeout immediately */
257  vec_insert (lm->intfs_timeouts, 1, lm->intfs_timeouts_idx);
258  lm->intfs_timeouts[lm->intfs_timeouts_idx] = n - lm->intfs;
259  vlib_process_signal_event (lm->vlib_main, lm->lldp_process_node_index,
260			     LLDP_EVENT_RESCHEDULE, 0);
261#if LLDP_DEBUG
262  clib_warning ("DEBUG: schedule interface %p, if idx %d", n, n->hw_if_index);
263#endif
264}
265
266void
267lldp_unschedule_intf (lldp_main_t * lm, lldp_intf_t * n)
268{
269  if (!n)
270    {
271      return;
272    }
273#if LLDP_DEBUG
274  clib_warning ("DEBUG: unschedule interface %p, if idx %d", n,
275		n->hw_if_index);
276#endif
277  const int idx = n - lm->intfs;
278  u32 v;
279  /* remove intf index from timeouts vector */
280  vec_foreach_index (v, lm->intfs_timeouts)
281  {
282    if (lm->intfs_timeouts[v] == idx)
283      {
284	vec_delete (lm->intfs_timeouts, 1, v);
285	break;
286      }
287  }
288  /* wrap current timeout index to first element if needed */
289  if (lm->intfs_timeouts_idx >= vec_len (lm->intfs_timeouts))
290    {
291      lm->intfs_timeouts_idx = 0;
292    }
293  vlib_process_signal_event (lm->vlib_main, lm->lldp_process_node_index,
294			     LLDP_EVENT_RESCHEDULE, 0);
295}
296
297static clib_error_t *
298lldp_sw_interface_up_down (vnet_main_t * vnm, u32 sw_if_index, u32 flags)
299{
300  lldp_main_t *lm = &lldp_main;
301  vnet_hw_interface_t *hi = vnet_get_sup_hw_interface (vnm, sw_if_index);
302  lldp_intf_t *n = lldp_get_intf (lm, hi->hw_if_index);
303  if (n)
304    {
305      if (!(flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP))
306	{
307	  /* FIXME - the packet sent here isn't send properly - need to find a
308	   * way to send the packet before interface goes down */
309	  lldp_send_ethernet (lm, n, 1);
310	  lldp_unschedule_intf (lm, n);
311	}
312    }
313  return 0;
314}
315
316VNET_SW_INTERFACE_ADMIN_UP_DOWN_FUNCTION (lldp_sw_interface_up_down);
317
318static clib_error_t *
319lldp_hw_interface_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
320{
321  lldp_main_t *lm = &lldp_main;
322  lldp_intf_t *n = lldp_get_intf (lm, hw_if_index);
323  if (n)
324    {
325      if (flags & VNET_HW_INTERFACE_FLAG_LINK_UP)
326	{
327	  lldp_schedule_intf (lm, n);
328	}
329    }
330  return 0;
331}
332
333VNET_HW_INTERFACE_LINK_UP_DOWN_FUNCTION (lldp_hw_interface_up_down);
334
335/*
336 * fd.io coding-style-patch-verification: ON
337 *
338 * Local Variables:
339 * eval: (c-set-style "gnu")
340 * End:
341 */
342