1/*
2 * Copyright (c) 2015 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 * ppp_node.c: ppp packet processing
17 *
18 * Copyright (c) 2010 Eliot Dresselhaus
19 *
20 * Permission is hereby granted, free of charge, to any person obtaining
21 * a copy of this software and associated documentation files (the
22 * "Software"), to deal in the Software without restriction, including
23 * without limitation the rights to use, copy, modify, merge, publish,
24 * distribute, sublicense, and/or sell copies of the Software, and to
25 * permit persons to whom the Software is furnished to do so, subject to
26 * the following conditions:
27 *
28 * The above copyright notice and this permission notice shall be
29 * included in all copies or substantial portions of the Software.
30 *
31 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
32 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
33 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
34 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
35 *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
36 *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
37 *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
38 */
39
40#include <vlib/vlib.h>
41#include <vnet/pg/pg.h>
42#include <vnet/ppp/ppp.h>
43#include <vppinfra/sparse_vec.h>
44
45#define foreach_ppp_input_next			\
46  _ (PUNT, "error-punt")			\
47  _ (DROP, "error-drop")
48
49typedef enum
50{
51#define _(s,n) PPP_INPUT_NEXT_##s,
52  foreach_ppp_input_next
53#undef _
54    PPP_INPUT_N_NEXT,
55} ppp_input_next_t;
56
57typedef struct
58{
59  u8 packet_data[32];
60} ppp_input_trace_t;
61
62static u8 *
63format_ppp_input_trace (u8 * s, va_list * va)
64{
65  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
66  CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
67  ppp_input_trace_t *t = va_arg (*va, ppp_input_trace_t *);
68
69  s = format (s, "%U", format_ppp_header, t->packet_data);
70
71  return s;
72}
73
74typedef struct
75{
76  /* Sparse vector mapping ppp protocol in network byte order
77     to next index. */
78  u16 *next_by_protocol;
79
80  u32 *sparse_index_by_next_index;
81} ppp_input_runtime_t;
82
83static uword
84ppp_input (vlib_main_t * vm,
85	   vlib_node_runtime_t * node, vlib_frame_t * from_frame)
86{
87  ppp_input_runtime_t *rt = (void *) node->runtime_data;
88  u32 n_left_from, next_index, i_next, *from, *to_next;
89
90  from = vlib_frame_vector_args (from_frame);
91  n_left_from = from_frame->n_vectors;
92
93  if (node->flags & VLIB_NODE_FLAG_TRACE)
94    vlib_trace_frame_buffers_only (vm, node,
95				   from,
96				   n_left_from,
97				   sizeof (from[0]),
98				   sizeof (ppp_input_trace_t));
99
100  next_index = node->cached_next_index;
101  i_next = vec_elt (rt->sparse_index_by_next_index, next_index);
102
103  while (n_left_from > 0)
104    {
105      u32 n_left_to_next;
106
107      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
108
109      while (n_left_from >= 4 && n_left_to_next >= 2)
110	{
111	  u32 bi0, bi1;
112	  vlib_buffer_t *b0, *b1;
113	  ppp_header_t *h0, *h1;
114	  u32 i0, i1, protocol0, protocol1, enqueue_code;
115
116	  /* Prefetch next iteration. */
117	  {
118	    vlib_buffer_t *p2, *p3;
119
120	    p2 = vlib_get_buffer (vm, from[2]);
121	    p3 = vlib_get_buffer (vm, from[3]);
122
123	    vlib_prefetch_buffer_header (p2, LOAD);
124	    vlib_prefetch_buffer_header (p3, LOAD);
125
126	    CLIB_PREFETCH (p2->data, sizeof (h0[0]), LOAD);
127	    CLIB_PREFETCH (p3->data, sizeof (h1[0]), LOAD);
128	  }
129
130	  bi0 = from[0];
131	  bi1 = from[1];
132	  to_next[0] = bi0;
133	  to_next[1] = bi1;
134	  from += 2;
135	  to_next += 2;
136	  n_left_to_next -= 2;
137	  n_left_from -= 2;
138
139	  b0 = vlib_get_buffer (vm, bi0);
140	  b1 = vlib_get_buffer (vm, bi1);
141
142	  h0 = vlib_buffer_get_current (b0);
143	  h1 = vlib_buffer_get_current (b1);
144
145	  vlib_buffer_advance (b0, sizeof (ppp_header_t));
146	  vlib_buffer_advance (b1, sizeof (ppp_header_t));
147
148	  /* Index sparse array with network byte order. */
149	  protocol0 = h0->protocol;
150	  protocol1 = h1->protocol;
151	  sparse_vec_index2 (rt->next_by_protocol, protocol0, protocol1, &i0,
152			     &i1);
153
154	  b0->error =
155	    node->errors[i0 ==
156			 SPARSE_VEC_INVALID_INDEX ? PPP_ERROR_UNKNOWN_PROTOCOL
157			 : PPP_ERROR_NONE];
158	  b1->error =
159	    node->errors[i1 ==
160			 SPARSE_VEC_INVALID_INDEX ? PPP_ERROR_UNKNOWN_PROTOCOL
161			 : PPP_ERROR_NONE];
162
163	  enqueue_code = (i0 != i_next) + 2 * (i1 != i_next);
164
165	  if (PREDICT_FALSE (enqueue_code != 0))
166	    {
167	      switch (enqueue_code)
168		{
169		case 1:
170		  /* A B A */
171		  to_next[-2] = bi1;
172		  to_next -= 1;
173		  n_left_to_next += 1;
174		  vlib_set_next_frame_buffer (vm, node,
175					      vec_elt (rt->next_by_protocol,
176						       i0), bi0);
177		  break;
178
179		case 2:
180		  /* A A B */
181		  to_next -= 1;
182		  n_left_to_next += 1;
183		  vlib_set_next_frame_buffer (vm, node,
184					      vec_elt (rt->next_by_protocol,
185						       i1), bi1);
186		  break;
187
188		case 3:
189		  /* A B B or A B C */
190		  to_next -= 2;
191		  n_left_to_next += 2;
192		  vlib_set_next_frame_buffer (vm, node,
193					      vec_elt (rt->next_by_protocol,
194						       i0), bi0);
195		  vlib_set_next_frame_buffer (vm, node,
196					      vec_elt (rt->next_by_protocol,
197						       i1), bi1);
198		  if (i0 == i1)
199		    {
200		      vlib_put_next_frame (vm, node, next_index,
201					   n_left_to_next);
202		      i_next = i1;
203		      next_index = vec_elt (rt->next_by_protocol, i_next);
204		      vlib_get_next_frame (vm, node, next_index, to_next,
205					   n_left_to_next);
206		    }
207		}
208	    }
209	}
210
211      while (n_left_from > 0 && n_left_to_next > 0)
212	{
213	  u32 bi0;
214	  vlib_buffer_t *b0;
215	  ppp_header_t *h0;
216	  u32 i0, protocol0;
217
218	  bi0 = from[0];
219	  to_next[0] = bi0;
220	  from += 1;
221	  to_next += 1;
222	  n_left_from -= 1;
223	  n_left_to_next -= 1;
224
225	  b0 = vlib_get_buffer (vm, bi0);
226
227	  h0 = vlib_buffer_get_current (b0);
228
229	  vlib_buffer_advance (b0, sizeof (ppp_header_t));
230
231	  protocol0 = h0->protocol;
232	  i0 = sparse_vec_index (rt->next_by_protocol, protocol0);
233
234	  b0->error =
235	    node->errors[i0 ==
236			 SPARSE_VEC_INVALID_INDEX ? PPP_ERROR_UNKNOWN_PROTOCOL
237			 : PPP_ERROR_NONE];
238
239	  /* Sent packet to wrong next? */
240	  if (PREDICT_FALSE (i0 != i_next))
241	    {
242	      /* Return old frame; remove incorrectly enqueued packet. */
243	      vlib_put_next_frame (vm, node, next_index, n_left_to_next + 1);
244
245	      /* Send to correct next. */
246	      i_next = i0;
247	      next_index = vec_elt (rt->next_by_protocol, i_next);
248	      vlib_get_next_frame (vm, node, next_index,
249				   to_next, n_left_to_next);
250	      to_next[0] = bi0;
251	      to_next += 1;
252	      n_left_to_next -= 1;
253	    }
254	}
255
256      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
257    }
258
259  return from_frame->n_vectors;
260}
261
262static char *ppp_error_strings[] = {
263#define ppp_error(n,s) s,
264#include "error.def"
265#undef ppp_error
266};
267
268/* *INDENT-OFF* */
269VLIB_REGISTER_NODE (ppp_input_node) = {
270  .function = ppp_input,
271  .name = "ppp-input",
272  /* Takes a vector of packets. */
273  .vector_size = sizeof (u32),
274
275  .runtime_data_bytes = sizeof (ppp_input_runtime_t),
276
277  .n_errors = PPP_N_ERROR,
278  .error_strings = ppp_error_strings,
279
280  .n_next_nodes = PPP_INPUT_N_NEXT,
281  .next_nodes = {
282#define _(s,n) [PPP_INPUT_NEXT_##s] = n,
283    foreach_ppp_input_next
284#undef _
285  },
286
287  .format_buffer = format_ppp_header_with_length,
288  .format_trace = format_ppp_input_trace,
289  .unformat_buffer = unformat_ppp_header,
290};
291/* *INDENT-ON* */
292
293static clib_error_t *
294ppp_input_runtime_init (vlib_main_t * vm)
295{
296  ppp_input_runtime_t *rt;
297
298  rt = vlib_node_get_runtime_data (vm, ppp_input_node.index);
299
300  rt->next_by_protocol = sparse_vec_new
301    ( /* elt bytes */ sizeof (rt->next_by_protocol[0]),
302     /* bits in index */ BITS (((ppp_header_t *) 0)->protocol));
303
304  vec_validate (rt->sparse_index_by_next_index, PPP_INPUT_NEXT_DROP);
305  vec_validate (rt->sparse_index_by_next_index, PPP_INPUT_NEXT_PUNT);
306  rt->sparse_index_by_next_index[PPP_INPUT_NEXT_DROP]
307    = SPARSE_VEC_INVALID_INDEX;
308  rt->sparse_index_by_next_index[PPP_INPUT_NEXT_PUNT]
309    = SPARSE_VEC_INVALID_INDEX;
310
311  return 0;
312}
313
314static clib_error_t *
315ppp_input_init (vlib_main_t * vm)
316{
317
318  {
319    clib_error_t *error = vlib_call_init_function (vm, ppp_init);
320    if (error)
321      clib_error_report (error);
322  }
323
324  ppp_setup_node (vm, ppp_input_node.index);
325  ppp_input_runtime_init (vm);
326
327  return 0;
328}
329
330VLIB_INIT_FUNCTION (ppp_input_init);
331VLIB_WORKER_INIT_FUNCTION (ppp_input_runtime_init);
332
333void
334ppp_register_input_protocol (vlib_main_t * vm,
335			     ppp_protocol_t protocol, u32 node_index)
336{
337  ppp_main_t *em = &ppp_main;
338  ppp_protocol_info_t *pi;
339  ppp_input_runtime_t *rt;
340  u16 *n;
341  u32 i;
342
343  {
344    clib_error_t *error = vlib_call_init_function (vm, ppp_input_init);
345    if (error)
346      clib_error_report (error);
347  }
348
349  pi = ppp_get_protocol_info (em, protocol);
350  pi->node_index = node_index;
351  pi->next_index = vlib_node_add_next (vm, ppp_input_node.index, node_index);
352
353  /* Setup ppp protocol -> next index sparse vector mapping. */
354  rt = vlib_node_get_runtime_data (vm, ppp_input_node.index);
355  n =
356    sparse_vec_validate (rt->next_by_protocol,
357			 clib_host_to_net_u16 (protocol));
358  n[0] = pi->next_index;
359
360  /* Rebuild next index -> sparse index inverse mapping when sparse vector
361     is updated. */
362  vec_validate (rt->sparse_index_by_next_index, pi->next_index);
363  for (i = 1; i < vec_len (rt->next_by_protocol); i++)
364    rt->sparse_index_by_next_index[rt->next_by_protocol[i]] = i;
365}
366
367/*
368 * fd.io coding-style-patch-verification: ON
369 *
370 * Local Variables:
371 * eval: (c-set-style "gnu")
372 * End:
373 */
374