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/devices/devices.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 mark_tcp_udp_cksum_calc (vlib_buffer_t * b)
114 ethernet_header_t *eth = vlib_buffer_get_current (b);
115 if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP4)
118 (vlib_buffer_get_current (b) + sizeof (ethernet_header_t));
119 b->flags |= VNET_BUFFER_F_IS_IP4;
120 if (ip4->protocol == IP_PROTOCOL_TCP)
122 b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
124 *) (vlib_buffer_get_current (b) +
125 sizeof (ethernet_header_t) +
126 ip4_header_bytes (ip4)))->checksum = 0;
128 else if (ip4->protocol == IP_PROTOCOL_UDP)
130 b->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
132 *) (vlib_buffer_get_current (b) +
133 sizeof (ethernet_header_t) +
134 ip4_header_bytes (ip4)))->checksum = 0;
136 vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t);
137 vnet_buffer (b)->l4_hdr_offset =
138 sizeof (ethernet_header_t) + ip4_header_bytes (ip4);
140 else if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP6)
143 (vlib_buffer_get_current (b) + sizeof (ethernet_header_t));
144 b->flags |= VNET_BUFFER_F_IS_IP6;
145 u16 ip6_hdr_len = sizeof (ip6_header_t);
146 if (ip6_ext_hdr (ip6->protocol))
148 ip6_ext_header_t *p = (void *) (ip6 + 1);
149 ip6_hdr_len += ip6_ext_header_len (p);
150 while (ip6_ext_hdr (p->next_hdr))
152 ip6_hdr_len += ip6_ext_header_len (p);
153 p = ip6_ext_next_header (p);
156 if (ip6->protocol == IP_PROTOCOL_TCP)
158 b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
160 *) (vlib_buffer_get_current (b) +
161 sizeof (ethernet_header_t) + ip6_hdr_len))->checksum = 0;
163 else if (ip6->protocol == IP_PROTOCOL_UDP)
165 b->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
167 *) (vlib_buffer_get_current (b) +
168 sizeof (ethernet_header_t) + ip6_hdr_len))->checksum = 0;
170 vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t);
171 vnet_buffer (b)->l4_hdr_offset =
172 sizeof (ethernet_header_t) + ip6_hdr_len;
177 af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
178 vlib_frame_t * frame, af_packet_if_t * apif)
180 af_packet_main_t *apm = &af_packet_main;
181 struct tpacket2_hdr *tph;
182 u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
186 u32 n_rx_packets = 0;
189 u32 block_size = apif->rx_req->tp_block_size;
190 u32 frame_size = apif->rx_req->tp_frame_size;
191 u32 frame_num = apif->rx_req->tp_frame_nr;
192 u8 *block_start = apif->rx_ring + block * block_size;
193 uword n_trace = vlib_get_trace_count (vm, node);
194 u32 thread_index = vm->thread_index;
195 u32 n_buffer_bytes = vlib_buffer_free_list_buffer_size (vm,
196 VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
197 u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes;
199 if (apif->per_interface_next_index != ~0)
200 next_index = apif->per_interface_next_index;
202 n_free_bufs = vec_len (apm->rx_buffers[thread_index]);
203 if (PREDICT_FALSE (n_free_bufs < VLIB_FRAME_SIZE))
205 vec_validate (apm->rx_buffers[thread_index],
206 VLIB_FRAME_SIZE + n_free_bufs - 1);
208 vlib_buffer_alloc (vm, &apm->rx_buffers[thread_index][n_free_bufs],
210 _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs;
213 rx_frame = apif->next_rx_frame;
214 tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
215 while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
217 vlib_buffer_t *b0 = 0, *first_b0 = 0;
218 u32 next0 = next_index;
221 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
222 while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) &&
225 u32 data_len = tph->tp_snaplen;
227 u32 bi0 = 0, first_bi0 = 0, prev_bi0;
231 /* grab free buffer */
232 u32 last_empty_buffer =
233 vec_len (apm->rx_buffers[thread_index]) - 1;
235 bi0 = apm->rx_buffers[thread_index][last_empty_buffer];
236 b0 = vlib_get_buffer (vm, bi0);
237 _vec_len (apm->rx_buffers[thread_index]) = last_empty_buffer;
242 data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
244 u32 bytes_copied = 0;
245 b0->current_data = 0;
246 /* Kernel removes VLAN headers, so reconstruct VLAN */
247 if (PREDICT_FALSE (tph->tp_status & TP_STATUS_VLAN_VALID))
249 if (PREDICT_TRUE (offset == 0))
251 clib_memcpy_fast (vlib_buffer_get_current (b0),
252 (u8 *) tph + tph->tp_mac,
253 sizeof (ethernet_header_t));
254 ethernet_header_t *eth = vlib_buffer_get_current (b0);
255 ethernet_vlan_header_t *vlan =
256 (ethernet_vlan_header_t *) (eth + 1);
257 vlan->priority_cfi_and_id =
258 clib_host_to_net_u16 (tph->tp_vlan_tci);
259 vlan->type = eth->type;
260 eth->type = clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
261 vlan_len = sizeof (ethernet_vlan_header_t);
262 bytes_copied = sizeof (ethernet_header_t);
265 clib_memcpy_fast (((u8 *) vlib_buffer_get_current (b0)) +
266 bytes_copied + vlan_len,
267 (u8 *) tph + tph->tp_mac + offset +
268 bytes_copied, (bytes_to_copy - bytes_copied));
270 /* fill buffer header */
271 b0->current_length = bytes_to_copy + vlan_len;
275 b0->total_length_not_including_first_buffer = 0;
276 b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
277 vnet_buffer (b0)->sw_if_index[VLIB_RX] = apif->sw_if_index;
278 vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
280 first_b0 = vlib_get_buffer (vm, first_bi0);
281 if (tph->tp_status & TP_STATUS_CSUMNOTREADY)
282 mark_tcp_udp_cksum_calc (first_b0);
285 buffer_add_to_chain (vm, bi0, first_bi0, prev_bi0);
287 offset += bytes_to_copy;
288 data_len -= bytes_to_copy;
291 n_rx_bytes += tph->tp_snaplen;
292 to_next[0] = first_bi0;
296 /* drop partial packets */
297 if (PREDICT_FALSE (tph->tp_len != tph->tp_snaplen))
299 next0 = VNET_DEVICE_INPUT_NEXT_DROP;
301 node->errors[AF_PACKET_INPUT_ERROR_PARTIAL_PKT];
305 next0 = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
306 /* redirect if feature path enabled */
307 vnet_feature_start_device_input_x1 (apif->sw_if_index, &next0,
312 VLIB_BUFFER_TRACE_TRAJECTORY_INIT (first_b0);
313 if (PREDICT_FALSE (n_trace > 0))
315 af_packet_input_trace_t *tr;
316 vlib_trace_buffer (vm, node, next0, first_b0, /* follow_chain */
318 vlib_set_trace_count (vm, node, --n_trace);
319 tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
320 tr->next_index = next0;
321 tr->hw_if_index = apif->hw_if_index;
322 clib_memcpy_fast (&tr->tph, tph, sizeof (struct tpacket2_hdr));
325 /* enque and take next packet */
326 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
327 n_left_to_next, first_bi0, next0);
330 tph->tp_status = TP_STATUS_KERNEL;
331 rx_frame = (rx_frame + 1) % frame_num;
332 tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
335 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
338 apif->next_rx_frame = rx_frame;
340 vlib_increment_combined_counter
341 (vnet_get_main ()->interface_main.combined_sw_if_counters
342 + VNET_INTERFACE_COUNTER_RX,
343 vlib_get_thread_index (), apif->hw_if_index, n_rx_packets, n_rx_bytes);
345 vnet_device_increment_rx_packets (thread_index, n_rx_packets);
350 af_packet_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
351 vlib_frame_t * frame)
353 u32 n_rx_packets = 0;
354 af_packet_main_t *apm = &af_packet_main;
355 vnet_device_input_runtime_t *rt = (void *) node->runtime_data;
356 vnet_device_and_queue_t *dq;
358 foreach_device_and_queue (dq, rt->devices_and_queues)
360 af_packet_if_t *apif;
361 apif = vec_elt_at_index (apm->interfaces, dq->dev_instance);
362 if (apif->is_admin_up)
363 n_rx_packets += af_packet_device_input_fn (vm, node, frame, apif);
370 VLIB_REGISTER_NODE (af_packet_input_node) = {
371 .function = af_packet_input_fn,
372 .name = "af-packet-input",
373 .sibling_of = "device-input",
374 .format_trace = format_af_packet_input_trace,
375 .type = VLIB_NODE_TYPE_INPUT,
376 .state = VLIB_NODE_STATE_INTERRUPT,
377 .n_errors = AF_PACKET_INPUT_N_ERROR,
378 .error_strings = af_packet_input_error_strings,
381 VLIB_NODE_FUNCTION_MULTIARCH (af_packet_input_node, af_packet_input_fn)
386 * fd.io coding-style-patch-verification: ON
389 * eval: (c-set-style "gnu")