2 *------------------------------------------------------------------
3 * af_packet.c - linux kernel packet interface
5 * Copyright (c) 2016 Cisco and/or its affiliates.
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at:
10 * http://www.apache.org/licenses/LICENSE-2.0
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 *------------------------------------------------------------------
20 #include <linux/if_packet.h>
22 #include <vlib/vlib.h>
23 #include <vlib/unix/unix.h>
24 #include <vnet/ip/ip.h>
25 #include <vnet/ethernet/ethernet.h>
26 #include <vnet/interface/rx_queue_funcs.h>
27 #include <vnet/feature/feature.h>
28 #include <vnet/ethernet/packet.h>
30 #include <vnet/devices/af_packet/af_packet.h>
32 #define foreach_af_packet_input_error \
33 _(PARTIAL_PKT, "partial packet")
37 #define _(f,s) AF_PACKET_INPUT_ERROR_##f,
38 foreach_af_packet_input_error
40 AF_PACKET_INPUT_N_ERROR,
41 } af_packet_input_error_t;
43 static char *af_packet_input_error_strings[] = {
45 foreach_af_packet_input_error
54 struct tpacket2_hdr tph;
55 } af_packet_input_trace_t;
58 format_af_packet_input_trace (u8 * s, va_list * args)
60 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
61 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
62 af_packet_input_trace_t *t = va_arg (*args, af_packet_input_trace_t *);
63 u32 indent = format_get_indent (s);
65 s = format (s, "af_packet: hw_if_index %d next-index %d",
66 t->hw_if_index, t->next_index);
70 "\n%Utpacket2_hdr:\n%Ustatus 0x%x len %u snaplen %u mac %u net %u"
71 "\n%Usec 0x%x nsec 0x%x vlan %U"
72 #ifdef TP_STATUS_VLAN_TPID_VALID
76 format_white_space, indent + 2,
77 format_white_space, indent + 4,
83 format_white_space, indent + 4,
85 t->tph.tp_nsec, format_ethernet_vlan_tci, t->tph.tp_vlan_tci
86 #ifdef TP_STATUS_VLAN_TPID_VALID
94 buffer_add_to_chain (vlib_main_t * vm, u32 bi, u32 first_bi, u32 prev_bi)
96 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
97 vlib_buffer_t *first_b = vlib_get_buffer (vm, first_bi);
98 vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_bi);
100 /* update first buffer */
101 first_b->total_length_not_including_first_buffer += b->current_length;
103 /* update previous buffer */
104 prev_b->next_buffer = bi;
105 prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
107 /* update current buffer */
111 static_always_inline void
112 fill_gso_buffer_flags (vlib_buffer_t *b, u32 gso_size, u8 l4_hdr_sz)
114 b->flags |= VNET_BUFFER_F_GSO;
115 vnet_buffer2 (b)->gso_size = gso_size;
116 vnet_buffer2 (b)->gso_l4_hdr_sz = l4_hdr_sz;
119 static_always_inline void
120 mark_tcp_udp_cksum_calc (vlib_buffer_t *b, u8 *l4_hdr_sz)
122 ethernet_header_t *eth = vlib_buffer_get_current (b);
123 if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP4)
126 (vlib_buffer_get_current (b) + sizeof (ethernet_header_t));
127 b->flags |= VNET_BUFFER_F_IS_IP4;
128 if (ip4->protocol == IP_PROTOCOL_TCP)
130 b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
131 tcp_header_t *tcp = (tcp_header_t *) (vlib_buffer_get_current (b) +
132 sizeof (ethernet_header_t) +
133 ip4_header_bytes (ip4));
135 *l4_hdr_sz = tcp_header_bytes (tcp);
137 else if (ip4->protocol == IP_PROTOCOL_UDP)
139 b->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
140 udp_header_t *udp = (udp_header_t *) (vlib_buffer_get_current (b) +
141 sizeof (ethernet_header_t) +
142 ip4_header_bytes (ip4));
144 *l4_hdr_sz = sizeof (*udp);
146 vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t);
147 vnet_buffer (b)->l4_hdr_offset =
148 sizeof (ethernet_header_t) + ip4_header_bytes (ip4);
150 else if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP6)
153 (vlib_buffer_get_current (b) + sizeof (ethernet_header_t));
154 b->flags |= VNET_BUFFER_F_IS_IP6;
155 u16 ip6_hdr_len = sizeof (ip6_header_t);
156 if (ip6_ext_hdr (ip6->protocol))
158 ip6_ext_header_t *p = (void *) (ip6 + 1);
159 ip6_hdr_len += ip6_ext_header_len (p);
160 while (ip6_ext_hdr (p->next_hdr))
162 ip6_hdr_len += ip6_ext_header_len (p);
163 p = ip6_ext_next_header (p);
166 if (ip6->protocol == IP_PROTOCOL_TCP)
168 b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
170 (tcp_header_t *) (vlib_buffer_get_current (b) +
171 sizeof (ethernet_header_t) + ip6_hdr_len);
173 *l4_hdr_sz = tcp_header_bytes (tcp);
175 else if (ip6->protocol == IP_PROTOCOL_UDP)
177 b->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
179 (udp_header_t *) (vlib_buffer_get_current (b) +
180 sizeof (ethernet_header_t) + ip6_hdr_len);
182 *l4_hdr_sz = sizeof (*udp);
184 vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t);
185 vnet_buffer (b)->l4_hdr_offset =
186 sizeof (ethernet_header_t) + ip6_hdr_len;
191 af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
192 vlib_frame_t * frame, af_packet_if_t * apif)
194 af_packet_main_t *apm = &af_packet_main;
195 struct tpacket2_hdr *tph;
196 u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
200 u32 n_rx_packets = 0;
203 u32 block_size = apif->rx_req->tp_block_size;
204 u32 frame_size = apif->rx_req->tp_frame_size;
205 u32 frame_num = apif->rx_req->tp_frame_nr;
206 u8 *block_start = apif->rx_ring + block * block_size;
207 uword n_trace = vlib_get_trace_count (vm, node);
208 u32 thread_index = vm->thread_index;
209 u32 n_buffer_bytes = vlib_buffer_get_default_data_size (vm);
210 u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes;
212 n_free_bufs = vec_len (apm->rx_buffers[thread_index]);
213 if (PREDICT_FALSE (n_free_bufs < VLIB_FRAME_SIZE))
215 vec_validate (apm->rx_buffers[thread_index],
216 VLIB_FRAME_SIZE + n_free_bufs - 1);
218 vlib_buffer_alloc (vm, &apm->rx_buffers[thread_index][n_free_bufs],
220 _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs;
223 rx_frame = apif->next_rx_frame;
224 tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
225 while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
227 vlib_buffer_t *b0 = 0, *first_b0 = 0;
228 u32 next0 = next_index;
231 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
232 while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) &&
235 u32 data_len = tph->tp_snaplen;
237 u32 bi0 = 0, first_bi0 = 0, prev_bi0;
242 /* grab free buffer */
243 u32 last_empty_buffer =
244 vec_len (apm->rx_buffers[thread_index]) - 1;
246 bi0 = apm->rx_buffers[thread_index][last_empty_buffer];
247 b0 = vlib_get_buffer (vm, bi0);
248 _vec_len (apm->rx_buffers[thread_index]) = last_empty_buffer;
253 data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
255 u32 bytes_copied = 0;
256 b0->current_data = 0;
257 /* Kernel removes VLAN headers, so reconstruct VLAN */
258 if (PREDICT_FALSE (tph->tp_status & TP_STATUS_VLAN_VALID))
260 if (PREDICT_TRUE (offset == 0))
262 clib_memcpy_fast (vlib_buffer_get_current (b0),
263 (u8 *) tph + tph->tp_mac,
264 sizeof (ethernet_header_t));
265 ethernet_header_t *eth = vlib_buffer_get_current (b0);
266 ethernet_vlan_header_t *vlan =
267 (ethernet_vlan_header_t *) (eth + 1);
268 vlan->priority_cfi_and_id =
269 clib_host_to_net_u16 (tph->tp_vlan_tci);
270 vlan->type = eth->type;
271 eth->type = clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
272 vlan_len = sizeof (ethernet_vlan_header_t);
273 bytes_copied = sizeof (ethernet_header_t);
276 clib_memcpy_fast (((u8 *) vlib_buffer_get_current (b0)) +
277 bytes_copied + vlan_len,
278 (u8 *) tph + tph->tp_mac + offset +
279 bytes_copied, (bytes_to_copy - bytes_copied));
281 /* fill buffer header */
282 b0->current_length = bytes_to_copy + vlan_len;
286 b0->total_length_not_including_first_buffer = 0;
287 b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
288 vnet_buffer (b0)->sw_if_index[VLIB_RX] = apif->sw_if_index;
289 vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
291 first_b0 = vlib_get_buffer (vm, first_bi0);
292 if (tph->tp_status & TP_STATUS_CSUMNOTREADY)
293 mark_tcp_udp_cksum_calc (first_b0, &l4_hdr_sz);
294 if (tph->tp_snaplen > apif->host_mtu)
295 fill_gso_buffer_flags (first_b0, apif->host_mtu,
299 buffer_add_to_chain (vm, bi0, first_bi0, prev_bi0);
301 offset += bytes_to_copy;
302 data_len -= bytes_to_copy;
305 n_rx_bytes += tph->tp_snaplen;
306 to_next[0] = first_bi0;
310 /* drop partial packets */
311 if (PREDICT_FALSE (tph->tp_len != tph->tp_snaplen))
313 next0 = VNET_DEVICE_INPUT_NEXT_DROP;
315 node->errors[AF_PACKET_INPUT_ERROR_PARTIAL_PKT];
319 next0 = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
321 if (PREDICT_FALSE (apif->per_interface_next_index != ~0))
322 next0 = apif->per_interface_next_index;
324 /* redirect if feature path enabled */
325 vnet_feature_start_device_input_x1 (apif->sw_if_index, &next0,
330 VLIB_BUFFER_TRACE_TRAJECTORY_INIT (first_b0);
332 (n_trace > 0 && vlib_trace_buffer (vm, node, next0, first_b0,
333 /* follow_chain */ 0)))
335 af_packet_input_trace_t *tr;
336 vlib_set_trace_count (vm, node, --n_trace);
337 tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
338 tr->next_index = next0;
339 tr->hw_if_index = apif->hw_if_index;
340 clib_memcpy_fast (&tr->tph, tph, sizeof (struct tpacket2_hdr));
343 /* enque and take next packet */
344 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
345 n_left_to_next, first_bi0, next0);
348 tph->tp_status = TP_STATUS_KERNEL;
349 rx_frame = (rx_frame + 1) % frame_num;
350 tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
353 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
356 apif->next_rx_frame = rx_frame;
358 vlib_increment_combined_counter
359 (vnet_get_main ()->interface_main.combined_sw_if_counters
360 + VNET_INTERFACE_COUNTER_RX,
361 vlib_get_thread_index (), apif->hw_if_index, n_rx_packets, n_rx_bytes);
363 vnet_device_increment_rx_packets (thread_index, n_rx_packets);
367 VLIB_NODE_FN (af_packet_input_node) (vlib_main_t * vm,
368 vlib_node_runtime_t * node,
369 vlib_frame_t * frame)
371 u32 n_rx_packets = 0;
372 af_packet_main_t *apm = &af_packet_main;
373 vnet_hw_if_rxq_poll_vector_t *pv;
374 pv = vnet_hw_if_get_rxq_poll_vector (vm, node);
375 for (int i = 0; i < vec_len (pv); i++)
377 af_packet_if_t *apif;
378 apif = vec_elt_at_index (apm->interfaces, pv[i].dev_instance);
379 if (apif->is_admin_up)
380 n_rx_packets += af_packet_device_input_fn (vm, node, frame, apif);
387 VLIB_REGISTER_NODE (af_packet_input_node) = {
388 .name = "af-packet-input",
389 .flags = VLIB_NODE_FLAG_TRACE_SUPPORTED,
390 .sibling_of = "device-input",
391 .format_trace = format_af_packet_input_trace,
392 .type = VLIB_NODE_TYPE_INPUT,
393 .state = VLIB_NODE_STATE_INTERRUPT,
394 .n_errors = AF_PACKET_INPUT_N_ERROR,
395 .error_strings = af_packet_input_error_strings,
401 * fd.io coding-style-patch-verification: ON
404 * eval: (c-set-style "gnu")