aboutsummaryrefslogtreecommitdiffstats
path: root/src/vnet/devices/af_packet/node.c
blob: ec7c273b0e5f92749da634e24356b68d8277b54a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
/*------------------------------------------------------------------
 * af_packet.c - linux kernel packet interface
 *
 * Copyright (c) 2016 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 <linux/if_packet.h>
#include <linux/virtio_net.h>

#include <vlib/vlib.h>
#include <vlib/unix/unix.h>
#include <vnet/ip/ip.h>
#include <vnet/ethernet/ethernet.h>
#include <vnet/devices/devices.h>
#include <vnet/feature/feature.h>

#include <vnet/devices/af_packet/af_packet.h>

#define foreach_af_packet_input_error

typedef enum
{
#define _(f,s) AF_PACKET_INPUT_ERROR_##f,
  foreach_af_packet_input_error
#undef _
    AF_PACKET_INPUT_N_ERROR,
} af_packet_input_error_t;

static char *af_packet_input_error_strings[] = {
#define _(n,s) s,
  foreach_af_packet_input_error
#undef _
};

typedef struct
{
  u32 next_index;
  u32 hw_if_index;
  int block;
  struct tpacket2_hdr tph;
} af_packet_input_trace_t;

static u8 *
format_af_packet_input_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 *);
  af_packet_input_trace_t *t = va_arg (*args, af_packet_input_trace_t *);
  u32 indent = format_get_indent (s);

  s = format (s, "af_packet: hw_if_index %d next-index %d",
	      t->hw_if_index, t->next_index);

  s =
    format (s,
	    "\n%Utpacket2_hdr:\n%Ustatus 0x%x len %u snaplen %u mac %u net %u"
	    "\n%Usec 0x%x nsec 0x%x vlan %U"
#ifdef TP_STATUS_VLAN_TPID_VALID
	    " vlan_tpid %u"
#endif
	    ,
	    format_white_space, indent + 2,
	    format_white_space, indent + 4,
	    t->tph.tp_status,
	    t->tph.tp_len,
	    t->tph.tp_snaplen,
	    t->tph.tp_mac,
	    t->tph.tp_net,
	    format_white_space, indent + 4,
	    t->tph.tp_sec,
	    t->tph.tp_nsec, format_ethernet_vlan_tci, t->tph.tp_vlan_tci
#ifdef TP_STATUS_VLAN_TPID_VALID
	    , t->tph.tp_vlan_tpid
#endif
    );
  return s;
}

always_inline void
buffer_add_to_chain (vlib_main_t * vm, u32 bi, u32 first_bi, u32 prev_bi)
{
  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
  vlib_buffer_t *first_b = vlib_get_buffer (vm, first_bi);
  vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_bi);

  /* update first buffer */
  first_b->total_length_not_including_first_buffer += b->current_length;

  /* update previous buffer */
  prev_b->next_buffer = bi;
  prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;

  /* update current buffer */
  b->next_buffer = 0;
}

always_inline uword
af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
			   vlib_frame_t * frame, af_packet_if_t * apif)
{
  af_packet_main_t *apm = &af_packet_main;
  struct tpacket2_hdr *tph;
  u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
  u32 block = 0;
  u32 rx_frame;
  u32 n_free_bufs;
  u32 n_rx_packets = 0;
  u32 n_rx_bytes = 0;
  u32 *to_next = 0;
  u32 block_size = apif->rx_req->tp_block_size;
  u32 frame_size = apif->rx_req->tp_frame_size;
  u32 frame_num = apif->rx_req->tp_frame_nr;
  u8 *block_start = apif->rx_ring + block * block_size;
  uword n_trace = vlib_get_trace_count (vm, node);
  u32 thread_index = vlib_get_thread_index ();
  u32 n_buffer_bytes = vlib_buffer_free_list_buffer_size (vm,
							  VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
  u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes;

  if (apif->per_interface_next_index != ~0)
    next_index = apif->per_interface_next_index;

  n_free_bufs = vec_len (apm->rx_buffers[thread_index]);
  if (PREDICT_FALSE (n_free_bufs < VLIB_FRAME_SIZE))
    {
      vec_validate (apm->rx_buffers[thread_index],
		    VLIB_FRAME_SIZE + n_free_bufs - 1);
      n_free_bufs +=
	vlib_buffer_alloc (vm, &apm->rx_buffers[thread_index][n_free_bufs],
			   VLIB_FRAME_SIZE);
      _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs;
    }

  rx_frame = apif->next_rx_frame;
  tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
  while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
    {
      vlib_buffer_t *b0 = 0, *first_b0 = 0;
      u32 next0 = next_index;

      u32 n_left_to_next;
      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
      while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) &&
	     n_left_to_next)
	{

	  struct virtio_net_hdr *vh =
	    (struct virtio_net_hdr *) (((u8 *) tph) + tph->tp_mac -
				       sizeof (struct virtio_net_hdr));
	  u32 data_len = tph->tp_snaplen;
	  u32 offset = 0;
	  u32 bi0 = 0, first_bi0 = 0, prev_bi0;
	  u32 vlan_len = 0;
	  ip_csum_t wsum = 0;
	  u16 *wsum_addr = NULL;
	  u32 do_vnet = apm->flags & AF_PACKET_USES_VNET_HEADERS;
	  u32 do_csum = tph->tp_status & TP_STATUS_CSUMNOTREADY;

	  while (data_len)
	    {
	      /* grab free buffer */
	      u32 last_empty_buffer =
		vec_len (apm->rx_buffers[thread_index]) - 1;
	      prev_bi0 = bi0;
	      bi0 = apm->rx_buffers[thread_index][last_empty_buffer];
	      b0 = vlib_get_buffer (vm, bi0);
	      _vec_len (apm->rx_buffers[thread_index]) = last_empty_buffer;
	      n_free_bufs--;

	      /* copy data */
	      u32 bytes_to_copy =
		data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
	      u32 bytes_copied = 0;
	      b0->current_data = 0;
	      /* Kernel removes VLAN headers, so reconstruct VLAN */
	      if (PREDICT_FALSE (tph->tp_status & TP_STATUS_VLAN_VALID))
		{
		  if (PREDICT_TRUE (offset == 0))
		    {
		      clib_memcpy (vlib_buffer_get_current (b0),
				   (u8 *) tph + tph->tp_mac,
				   sizeof (ethernet_header_t));
		      ethernet_header_t *eth = vlib_buffer_get_current (b0);
		      ethernet_vlan_header_t *vlan =
			(ethernet_vlan_header_t *) (eth + 1);
		      vlan->priority_cfi_and_id =
			clib_host_to_net_u16 (tph->tp_vlan_tci);
		      vlan->type = eth->type;
		      eth->type = clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
		      vlan_len = sizeof (ethernet_vlan_header_t);
		      bytes_copied = sizeof (ethernet_header_t);
		    }
		}
	      /* Check if the incoming skb is marked as CSUM_PARTIAL,
	       * If VNET Headers are enabled TP_STATUS_CSUMNOTREADY is
	       * equivalent to the vnet csum flag.
	       **/
	      if (PREDICT_TRUE ((do_vnet != 0) && (do_csum != 0)))
		{
		  wsum_addr = (u16 *) (((u8 *) vlib_buffer_get_current (b0)) +
				       vlan_len + vh->csum_start +
				       vh->csum_offset);
		  if (bytes_copied <= vh->csum_start)
		    {
		      clib_memcpy (((u8 *) vlib_buffer_get_current (b0)) +
				   bytes_copied + vlan_len,
				   (u8 *) tph + tph->tp_mac + offset +
				   bytes_copied,
				   (vh->csum_start - bytes_copied));
		      wsum =
			ip_csum_and_memcpy (wsum,
					    ((u8 *)
					     vlib_buffer_get_current (b0)) +
					    vh->csum_start + vlan_len,
					    (u8 *) tph + tph->tp_mac +
					    offset + vh->csum_start,
					    (bytes_to_copy - vh->csum_start));
		    }
		  else
		    {
		      wsum =
			ip_csum_and_memcpy (wsum,
					    ((u8 *)
					     vlib_buffer_get_current (b0)) +
					    bytes_copied + vlan_len,
					    (u8 *) tph + tph->tp_mac +
					    offset + bytes_copied,
					    (bytes_to_copy - bytes_copied));
		    }
		}
	      else
		{
		  clib_memcpy (((u8 *) vlib_buffer_get_current (b0)) +
			       bytes_copied + vlan_len,
			       (u8 *) tph + tph->tp_mac + offset +
			       bytes_copied, (bytes_to_copy - bytes_copied));
		}

	      /* fill buffer header */
	      b0->current_length = bytes_to_copy + vlan_len;

	      if (offset == 0)
		{
		  b0->total_length_not_including_first_buffer = 0;
		  b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
		  vnet_buffer (b0)->sw_if_index[VLIB_RX] = apif->sw_if_index;
		  vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
		  first_bi0 = bi0;
		  first_b0 = vlib_get_buffer (vm, first_bi0);
		}
	      else
		buffer_add_to_chain (vm, bi0, first_bi0, prev_bi0);

	      offset += bytes_to_copy;
	      data_len -= bytes_to_copy;
	    }
	  if (PREDICT_TRUE ((do_vnet != 0) && (do_csum != 0)))
	    {
	      *wsum_addr = ~ip_csum_fold (wsum);
	    }
	  n_rx_packets++;
	  n_rx_bytes += tph->tp_snaplen;
	  to_next[0] = first_bi0;
	  to_next += 1;
	  n_left_to_next--;

	  /* trace */
	  VLIB_BUFFER_TRACE_TRAJECTORY_INIT (first_b0);
	  if (PREDICT_FALSE (n_trace > 0))
	    {
	      af_packet_input_trace_t *tr;
	      vlib_trace_buffer (vm, node, next0, first_b0,	/* follow_chain */
				 0);
	      vlib_set_trace_count (vm, node, --n_trace);
	      tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
	      tr->next_index = next0;
	      tr->hw_if_index = apif->hw_if_index;
	      clib_memcpy (&tr->tph, tph, sizeof (struct tpacket2_hdr));
	    }

	  /* redirect if feature path enabled */
	  vnet_feature_start_device_input_x1 (apif->sw_if_index, &next0, b0);

	  /* enque and take next packet */
	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
					   n_left_to_next, first_bi0, next0);

	  /* next packet */
	  tph->tp_status = TP_STATUS_KERNEL;
	  rx_frame = (rx_frame + 1) % frame_num;
	  tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
	}

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

  apif->next_rx_frame = rx_frame;

  vlib_increment_combined_counter
    (vnet_get_main ()->interface_main.combined_sw_if_counters
     + VNET_INTERFACE_COUNTER_RX,
     vlib_get_thread_index (), apif->hw_if_index, n_rx_packets, n_rx_bytes);

  vnet_device_increment_rx_packets (thread_index, n_rx_packets);
  return n_rx_packets;
}

static uword
af_packet_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
		    vlib_frame_t * frame)
{
  u32 n_rx_packets = 0;
  af_packet_main_t *apm = &af_packet_main;
  vnet_device_input_runtime_t *rt = (void *) node->runtime_data;
  vnet_device_and_queue_t *dq;

  foreach_device_and_queue (dq, rt->devices_and_queues)
  {
    af_packet_if_t *apif;
    apif = vec_elt_at_index (apm->interfaces, dq->dev_instance);
    if (apif->is_admin_up)
      n_rx_packets += af_packet_device_input_fn (vm, node, frame, apif);
  }

  return n_rx_packets;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (af_packet_input_node) = {
  .function = af_packet_input_fn,
  .name = "af-packet-input",
  .sibling_of = "device-input",
  .format_trace = format_af_packet_input_trace,
  .type = VLIB_NODE_TYPE_INPUT,
  .state = VLIB_NODE_STATE_INTERRUPT,
  .n_errors = AF_PACKET_INPUT_N_ERROR,
  .error_strings = af_packet_input_error_strings,
};

VLIB_NODE_FUNCTION_MULTIARCH (af_packet_input_node, af_packet_input_fn)
/* *INDENT-ON* */


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