ct6_in2out.c revision d318a996
1/*
2 * ct6_in2out.c - ip6 connection tracker, inside-to-outside path
3 *
4 * Copyright (c) 2019 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#include <vlib/vlib.h>
18#include <vnet/vnet.h>
19#include <vnet/pg/pg.h>
20#include <vppinfra/error.h>
21#include <ct6/ct6.h>
22
23typedef struct
24{
25  u32 sw_if_index;
26  u32 next_index;
27  u32 session_index;
28} ct6_in2out_trace_t;
29
30#ifndef CLIB_MARCH_VARIANT
31
32/* packet trace format function */
33static u8 *
34format_ct6_in2out_trace (u8 * s, va_list * args)
35{
36  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
37  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
38  ct6_in2out_trace_t *t = va_arg (*args, ct6_in2out_trace_t *);
39
40  s = format (s, "CT6_IN2OUT: sw_if_index %d, next index %d session %d\n",
41	      t->sw_if_index, t->next_index, t->session_index);
42  return s;
43}
44
45vlib_node_registration_t ct6_in2out_node;
46
47#endif /* CLIB_MARCH_VARIANT */
48
49#define foreach_ct6_in2out_error                \
50_(PROCESSED, "ct6 packets processed")           \
51_(CREATED, "ct6 sessions created")              \
52_(RECYCLED, "ct6 sessions recycled")
53
54typedef enum
55{
56#define _(sym,str) CT6_IN2OUT_ERROR_##sym,
57  foreach_ct6_in2out_error
58#undef _
59    CT6_IN2OUT_N_ERROR,
60} ct6_in2out_error_t;
61
62#ifndef CLIB_MARCH_VARIANT
63static char *ct6_in2out_error_strings[] = {
64#define _(sym,string) string,
65  foreach_ct6_in2out_error
66#undef _
67};
68#endif /* CLIB_MARCH_VARIANT */
69
70typedef enum
71{
72  CT6_IN2OUT_NEXT_DROP,
73  CT6_IN2OUT_N_NEXT,
74} ct6_next_t;
75
76#ifndef CLIB_MARCH_VARIANT
77ct6_session_t *
78ct6_create_or_recycle_session (ct6_main_t * cmp,
79			       clib_bihash_kv_48_8_t * kvpp, f64 now,
80			       u32 my_thread_index, u32 * recyclep,
81			       u32 * createp)
82{
83  ct6_session_t *s0;
84
85  /* Empty arena? */
86  if (PREDICT_FALSE (cmp->last_index[my_thread_index] == ~0))
87    goto alloc0;
88
89  /* Look at the least-recently-used session */
90  s0 = pool_elt_at_index (cmp->sessions[my_thread_index],
91			  cmp->last_index[my_thread_index]);
92
93  if (CLIB_DEBUG > 0 && s0->expires < now)
94    clib_warning ("session %d expired %.2f time now %.2f",
95		  s0 - cmp->sessions[my_thread_index], s0->expires, now);
96
97  if (CLIB_DEBUG > 0 && pool_elts (cmp->sessions[my_thread_index]) >=
98      cmp->max_sessions_per_worker)
99    clib_warning ("recycle session %d have %d max %d",
100		  s0 - cmp->sessions[my_thread_index],
101		  pool_elts (cmp->sessions[my_thread_index]),
102		  cmp->max_sessions_per_worker);
103
104  /* Session expired, or we have as many sessions as is allowed by law? */
105  if ((s0->expires < now) || (pool_elts (cmp->sessions[my_thread_index])
106			      >= cmp->max_sessions_per_worker))
107    {
108      /* recycle the session */
109      if (clib_bihash_add_del_48_8 (&cmp->session_hash,
110				    (clib_bihash_kv_48_8_t *) s0,
111				    0 /* is_add */ ) < 0)
112	clib_warning ("session %d not found in hash?",
113		      s0 - cmp->sessions[my_thread_index]);
114
115      ct6_lru_remove (cmp, s0);
116      *recyclep += 1;
117    }
118  else
119    {
120    alloc0:
121      /* Allocate a fresh session */
122      pool_get (cmp->sessions[my_thread_index], s0);
123      *createp += 1;
124    }
125
126  /* Session setup */
127  memset (s0, 0, sizeof (*s0));
128  clib_memcpy_fast (s0, kvpp, sizeof (ct6_session_key_t));
129  s0->thread_index = my_thread_index;
130  s0->expires = now + cmp->session_timeout_interval;
131  kvpp->value = s0 - cmp->sessions[my_thread_index];
132  clib_bihash_add_del_48_8 (&cmp->session_hash, kvpp, 1 /* is_add */ );
133  ct6_lru_add (cmp, s0, now);
134  return s0;
135}
136#endif /* CLIB_MARCH_VARIANT */
137
138always_inline uword
139ct6_in2out_inline (vlib_main_t * vm,
140		   vlib_node_runtime_t * node, vlib_frame_t * frame,
141		   int is_trace)
142{
143  u32 n_left_from, *from;
144  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
145  u16 nexts[VLIB_FRAME_SIZE], *next;
146  ct6_main_t *cmp = &ct6_main;
147  u32 my_thread_index = vm->thread_index;
148  f64 now = vlib_time_now (vm);
149  u32 created = 0;
150  u32 recycled = 0;
151
152  from = vlib_frame_vector_args (frame);
153  n_left_from = frame->n_vectors;
154
155  vlib_get_buffers (vm, from, bufs, n_left_from);
156  b = bufs;
157  next = nexts;
158
159#if 0
160  while (n_left_from >= 4)
161    {
162      /* Prefetch next iteration. */
163      if (PREDICT_TRUE (n_left_from >= 8))
164	{
165	  vlib_prefetch_buffer_header (b[4], STORE);
166	  vlib_prefetch_buffer_header (b[5], STORE);
167	  vlib_prefetch_buffer_header (b[6], STORE);
168	  vlib_prefetch_buffer_header (b[7], STORE);
169	  CLIB_PREFETCH (b[4]->data, CLIB_CACHE_LINE_BYTES, STORE);
170	  CLIB_PREFETCH (b[5]->data, CLIB_CACHE_LINE_BYTES, STORE);
171	  CLIB_PREFETCH (b[6]->data, CLIB_CACHE_LINE_BYTES, STORE);
172	  CLIB_PREFETCH (b[7]->data, CLIB_CACHE_LINE_BYTES, STORE);
173	}
174
175      /* $$$$ process 4x pkts right here */
176      next[0] = 0;
177      next[1] = 0;
178      next[2] = 0;
179      next[3] = 0;
180
181      if (is_trace)
182	{
183	  if (b[0]->flags & VLIB_BUFFER_IS_TRACED)
184	    {
185	      ct6_trace_t *t = vlib_add_trace (vm, node, b[0], sizeof (*t));
186	      t->next_index = next[0];
187	      t->sw_if_index = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
188	    }
189	  if (b[1]->flags & VLIB_BUFFER_IS_TRACED)
190	    {
191	      ct6_trace_t *t = vlib_add_trace (vm, node, b[1], sizeof (*t));
192	      t->next_index = next[1];
193	      t->sw_if_index = vnet_buffer (b[1])->sw_if_index[VLIB_RX];
194	    }
195	  if (b[2]->flags & VLIB_BUFFER_IS_TRACED)
196	    {
197	      ct6_trace_t *t = vlib_add_trace (vm, node, b[2], sizeof (*t));
198	      t->next_index = next[2];
199	      t->sw_if_index = vnet_buffer (b[2])->sw_if_index[VLIB_RX];
200	    }
201	  if (b[3]->flags & VLIB_BUFFER_IS_TRACED)
202	    {
203	      ct6_trace_t *t = vlib_add_trace (vm, node, b[3], sizeof (*t));
204	      t->next_index = next[3];
205	      t->sw_if_index = vnet_buffer (b[3])->sw_if_index[VLIB_RX];
206	    }
207	}
208
209      b += 4;
210      next += 4;
211      n_left_from -= 4;
212    }
213#endif
214
215  while (n_left_from > 0)
216    {
217      clib_bihash_kv_48_8_t kvp0;
218      ct6_session_key_t *key0;
219      ct6_session_t *s0;
220      u32 session_index0 = ~0;
221      u32 next0, delta0;
222      ethernet_header_t *e0;
223
224      ip6_header_t *ip0;
225      udp_header_t *udp0;
226
227      /* $$$ Set to 0 for pg testing */
228      if (1)
229	{
230	  vnet_feature_next (&next0, b[0]);
231	  next[0] = next0;
232	}
233      else
234	next[0] = CT6_IN2OUT_NEXT_DROP;
235
236      /*
237       * This is an output feature which runs at the last possible
238       * moment. Assume an ethernet header. Make sure the packet is
239       * actually ipv6 before we do anything else.
240       *
241       * Unfortunately, we have to re-parse the L2 header.
242       */
243
244      e0 = vlib_buffer_get_current (b[0]);
245      delta0 = sizeof (*e0);
246      delta0 += (e0->type == clib_net_to_host_u16 (ETHERNET_TYPE_VLAN))
247	? 4 : 0;
248      delta0 += (e0->type == clib_net_to_host_u16 (ETHERNET_TYPE_DOT1AD))
249	? 8 : 0;
250
251      if (PREDICT_TRUE (delta0 == sizeof (*e0)))
252	{
253	  if (e0->type != clib_host_to_net_u16 (ETHERNET_TYPE_IP6))
254	    goto trace0;
255	}
256      else
257	{
258	  u16 *tagged_etype_ptr = vlib_buffer_get_current (b[0]) + delta0 - 2;
259	  if (*tagged_etype_ptr != clib_host_to_net_u16 (ETHERNET_TYPE_IP6))
260	    goto trace0;
261	}
262
263      ip0 = (ip6_header_t *) (vlib_buffer_get_current (b[0]) + delta0);
264
265      /*
266       * Pass non-global unicast traffic
267       */
268      if (PREDICT_FALSE (!ip6_address_is_global_unicast (&ip0->src_address)
269			 ||
270			 !ip6_address_is_global_unicast (&ip0->src_address)))
271	goto trace0;
272      /* Pass non-udp, non-tcp traffic */
273      if (PREDICT_FALSE (ip0->protocol != IP_PROTOCOL_TCP &&
274			 ip0->protocol != IP_PROTOCOL_UDP))
275	goto trace0;
276
277      udp0 = ip6_next_header (ip0);
278
279      /*
280       * See if we know about this flow.
281       * Key set up for the out2in path, the performant case
282       */
283      key0 = (ct6_session_key_t *) & kvp0;
284      clib_memcpy_fast (&key0->src, &ip0->dst_address,
285			sizeof (ip6_address_t));
286      clib_memcpy_fast (&key0->dst, &ip0->src_address,
287			sizeof (ip6_address_t));
288      key0->as_u64[4] = 0;
289      key0->as_u64[5] = 0;
290      key0->sport = udp0->dst_port;
291      key0->dport = udp0->src_port;
292      key0->proto = ip0->protocol;
293
294      /* Need to create a new session? */
295      if (clib_bihash_search_48_8 (&cmp->session_hash, &kvp0, &kvp0) < 0)
296	{
297	  s0 =
298	    ct6_create_or_recycle_session (cmp, &kvp0, now, my_thread_index,
299					   &recycled, &created);
300	  session_index0 = kvp0.value;
301	}
302      else
303	{
304	  s0 = pool_elt_at_index (cmp->sessions[my_thread_index], kvp0.value);
305	  session_index0 = kvp0.value;
306	  ct6_update_session_hit (cmp, s0, now);
307	}
308
309    trace0:
310      if (is_trace)
311	{
312	  if (b[0]->flags & VLIB_BUFFER_IS_TRACED)
313	    {
314	      ct6_in2out_trace_t *t =
315		vlib_add_trace (vm, node, b[0], sizeof (*t));
316	      t->next_index = next[0];
317	      t->sw_if_index = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
318	      t->session_index = session_index0;
319	    }
320	}
321
322      b += 1;
323      next += 1;
324      n_left_from -= 1;
325    }
326
327  vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
328
329  vlib_node_increment_counter (vm, node->node_index,
330			       CT6_IN2OUT_ERROR_PROCESSED, frame->n_vectors);
331  vlib_node_increment_counter (vm, node->node_index,
332			       CT6_IN2OUT_ERROR_CREATED, created);
333  vlib_node_increment_counter (vm, node->node_index,
334			       CT6_IN2OUT_ERROR_RECYCLED, recycled);
335
336  return frame->n_vectors;
337}
338
339VLIB_NODE_FN (ct6_in2out_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
340				vlib_frame_t * frame)
341{
342  if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
343    return ct6_in2out_inline (vm, node, frame, 1 /* is_trace */ );
344  else
345    return ct6_in2out_inline (vm, node, frame, 0 /* is_trace */ );
346}
347
348/* *INDENT-OFF* */
349#ifndef CLIB_MARCH_VARIANT
350VLIB_REGISTER_NODE (ct6_in2out_node) =
351{
352  .name = "ct6-in2out",
353  .vector_size = sizeof (u32),
354  .format_trace = format_ct6_in2out_trace,
355  .type = VLIB_NODE_TYPE_INTERNAL,
356
357  .n_errors = ARRAY_LEN(ct6_in2out_error_strings),
358  .error_strings = ct6_in2out_error_strings,
359
360  .n_next_nodes = CT6_IN2OUT_N_NEXT,
361
362  /* edit / add dispositions here */
363  .next_nodes = {
364        [CT6_IN2OUT_NEXT_DROP] = "error-drop",
365  },
366  .unformat_buffer = unformat_ethernet_header,
367};
368#endif /* CLIB_MARCH_VARIANT */
369/* *INDENT-ON* */
370
371/*
372 * fd.io coding-style-patch-verification: ON
373 *
374 * Local Variables:
375 * eval: (c-set-style "gnu")
376 * End:
377 */
378