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);
124 if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP4)
127 (vlib_buffer_get_current (b) + sizeof (ethernet_header_t));
128 b->flags |= VNET_BUFFER_F_IS_IP4;
129 if (ip4->protocol == IP_PROTOCOL_TCP)
131 oflags |= VNET_BUFFER_OFFLOAD_F_TCP_CKSUM;
132 tcp_header_t *tcp = (tcp_header_t *) (vlib_buffer_get_current (b) +
133 sizeof (ethernet_header_t) +
134 ip4_header_bytes (ip4));
136 *l4_hdr_sz = tcp_header_bytes (tcp);
138 else if (ip4->protocol == IP_PROTOCOL_UDP)
140 oflags |= VNET_BUFFER_OFFLOAD_F_UDP_CKSUM;
141 udp_header_t *udp = (udp_header_t *) (vlib_buffer_get_current (b) +
142 sizeof (ethernet_header_t) +
143 ip4_header_bytes (ip4));
145 *l4_hdr_sz = sizeof (*udp);
147 vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t);
148 vnet_buffer (b)->l4_hdr_offset =
149 sizeof (ethernet_header_t) + ip4_header_bytes (ip4);
151 vnet_buffer_offload_flags_set (b, oflags);
153 else if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP6)
156 (vlib_buffer_get_current (b) + sizeof (ethernet_header_t));
157 b->flags |= VNET_BUFFER_F_IS_IP6;
158 u16 ip6_hdr_len = sizeof (ip6_header_t);
159 if (ip6_ext_hdr (ip6->protocol))
161 ip6_ext_header_t *p = (void *) (ip6 + 1);
162 ip6_hdr_len += ip6_ext_header_len (p);
163 while (ip6_ext_hdr (p->next_hdr))
165 ip6_hdr_len += ip6_ext_header_len (p);
166 p = ip6_ext_next_header (p);
169 if (ip6->protocol == IP_PROTOCOL_TCP)
171 oflags |= VNET_BUFFER_OFFLOAD_F_TCP_CKSUM;
173 (tcp_header_t *) (vlib_buffer_get_current (b) +
174 sizeof (ethernet_header_t) + ip6_hdr_len);
176 *l4_hdr_sz = tcp_header_bytes (tcp);
178 else if (ip6->protocol == IP_PROTOCOL_UDP)
180 oflags |= VNET_BUFFER_OFFLOAD_F_UDP_CKSUM;
182 (udp_header_t *) (vlib_buffer_get_current (b) +
183 sizeof (ethernet_header_t) + ip6_hdr_len);
185 *l4_hdr_sz = sizeof (*udp);
187 vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t);
188 vnet_buffer (b)->l4_hdr_offset =
189 sizeof (ethernet_header_t) + ip6_hdr_len;
191 vnet_buffer_offload_flags_set (b, oflags);
196 af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
197 vlib_frame_t * frame, af_packet_if_t * apif)
199 af_packet_main_t *apm = &af_packet_main;
200 struct tpacket2_hdr *tph;
201 u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
205 u32 n_rx_packets = 0;
208 u32 block_size = apif->rx_req->tp_block_size;
209 u32 frame_size = apif->rx_req->tp_frame_size;
210 u32 frame_num = apif->rx_req->tp_frame_nr;
211 u8 *block_start = apif->rx_ring + block * block_size;
212 uword n_trace = vlib_get_trace_count (vm, node);
213 u32 thread_index = vm->thread_index;
214 u32 n_buffer_bytes = vlib_buffer_get_default_data_size (vm);
215 u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes;
217 n_free_bufs = vec_len (apm->rx_buffers[thread_index]);
218 if (PREDICT_FALSE (n_free_bufs < VLIB_FRAME_SIZE))
220 vec_validate (apm->rx_buffers[thread_index],
221 VLIB_FRAME_SIZE + n_free_bufs - 1);
223 vlib_buffer_alloc (vm, &apm->rx_buffers[thread_index][n_free_bufs],
225 _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs;
228 rx_frame = apif->next_rx_frame;
229 tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
230 while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
232 vlib_buffer_t *b0 = 0, *first_b0 = 0;
233 u32 next0 = next_index;
236 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
237 while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) &&
240 u32 data_len = tph->tp_snaplen;
242 u32 bi0 = 0, first_bi0 = 0, prev_bi0;
247 /* grab free buffer */
248 u32 last_empty_buffer =
249 vec_len (apm->rx_buffers[thread_index]) - 1;
251 bi0 = apm->rx_buffers[thread_index][last_empty_buffer];
252 b0 = vlib_get_buffer (vm, bi0);
253 _vec_len (apm->rx_buffers[thread_index]) = last_empty_buffer;
258 data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
260 u32 bytes_copied = 0;
261 b0->current_data = 0;
262 /* Kernel removes VLAN headers, so reconstruct VLAN */
263 if (PREDICT_FALSE (tph->tp_status & TP_STATUS_VLAN_VALID))
265 if (PREDICT_TRUE (offset == 0))
267 clib_memcpy_fast (vlib_buffer_get_current (b0),
268 (u8 *) tph + tph->tp_mac,
269 sizeof (ethernet_header_t));
270 ethernet_header_t *eth = vlib_buffer_get_current (b0);
271 ethernet_vlan_header_t *vlan =
272 (ethernet_vlan_header_t *) (eth + 1);
273 vlan->priority_cfi_and_id =
274 clib_host_to_net_u16 (tph->tp_vlan_tci);
275 vlan->type = eth->type;
276 eth->type = clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
277 vlan_len = sizeof (ethernet_vlan_header_t);
278 bytes_copied = sizeof (ethernet_header_t);
281 clib_memcpy_fast (((u8 *) vlib_buffer_get_current (b0)) +
282 bytes_copied + vlan_len,
283 (u8 *) tph + tph->tp_mac + offset +
284 bytes_copied, (bytes_to_copy - bytes_copied));
286 /* fill buffer header */
287 b0->current_length = bytes_to_copy + vlan_len;
291 b0->total_length_not_including_first_buffer = 0;
292 b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
293 vnet_buffer (b0)->sw_if_index[VLIB_RX] = apif->sw_if_index;
294 vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
296 first_b0 = vlib_get_buffer (vm, first_bi0);
297 if (tph->tp_status & TP_STATUS_CSUMNOTREADY)
298 mark_tcp_udp_cksum_calc (first_b0, &l4_hdr_sz);
299 if (tph->tp_snaplen > apif->host_mtu)
300 fill_gso_buffer_flags (first_b0, apif->host_mtu,
304 buffer_add_to_chain (vm, bi0, first_bi0, prev_bi0);
306 offset += bytes_to_copy;
307 data_len -= bytes_to_copy;
310 n_rx_bytes += tph->tp_snaplen;
311 to_next[0] = first_bi0;
315 /* drop partial packets */
316 if (PREDICT_FALSE (tph->tp_len != tph->tp_snaplen))
318 next0 = VNET_DEVICE_INPUT_NEXT_DROP;
320 node->errors[AF_PACKET_INPUT_ERROR_PARTIAL_PKT];
324 next0 = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
326 if (PREDICT_FALSE (apif->per_interface_next_index != ~0))
327 next0 = apif->per_interface_next_index;
329 /* redirect if feature path enabled */
330 vnet_feature_start_device_input_x1 (apif->sw_if_index, &next0,
336 (n_trace > 0 && vlib_trace_buffer (vm, node, next0, first_b0,
337 /* follow_chain */ 0)))
339 af_packet_input_trace_t *tr;
340 vlib_set_trace_count (vm, node, --n_trace);
341 tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
342 tr->next_index = next0;
343 tr->hw_if_index = apif->hw_if_index;
344 clib_memcpy_fast (&tr->tph, tph, sizeof (struct tpacket2_hdr));
347 /* enque and take next packet */
348 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
349 n_left_to_next, first_bi0, next0);
352 tph->tp_status = TP_STATUS_KERNEL;
353 rx_frame = (rx_frame + 1) % frame_num;
354 tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
357 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
360 apif->next_rx_frame = rx_frame;
362 vlib_increment_combined_counter
363 (vnet_get_main ()->interface_main.combined_sw_if_counters
364 + VNET_INTERFACE_COUNTER_RX,
365 vlib_get_thread_index (), apif->hw_if_index, n_rx_packets, n_rx_bytes);
367 vnet_device_increment_rx_packets (thread_index, n_rx_packets);
371 VLIB_NODE_FN (af_packet_input_node) (vlib_main_t * vm,
372 vlib_node_runtime_t * node,
373 vlib_frame_t * frame)
375 u32 n_rx_packets = 0;
376 af_packet_main_t *apm = &af_packet_main;
377 vnet_hw_if_rxq_poll_vector_t *pv;
378 pv = vnet_hw_if_get_rxq_poll_vector (vm, node);
379 for (int i = 0; i < vec_len (pv); i++)
381 af_packet_if_t *apif;
382 apif = vec_elt_at_index (apm->interfaces, pv[i].dev_instance);
383 if (apif->is_admin_up)
384 n_rx_packets += af_packet_device_input_fn (vm, node, frame, apif);
391 VLIB_REGISTER_NODE (af_packet_input_node) = {
392 .name = "af-packet-input",
393 .flags = VLIB_NODE_FLAG_TRACE_SUPPORTED,
394 .sibling_of = "device-input",
395 .format_trace = format_af_packet_input_trace,
396 .type = VLIB_NODE_TYPE_INPUT,
397 .state = VLIB_NODE_STATE_INTERRUPT,
398 .n_errors = AF_PACKET_INPUT_N_ERROR,
399 .error_strings = af_packet_input_error_strings,
405 * fd.io coding-style-patch-verification: ON
408 * eval: (c-set-style "gnu")