1 /*------------------------------------------------------------------
2 * af_packet.c - linux kernel packet interface
4 * Copyright (c) 2016 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:
9 * http://www.apache.org/licenses/LICENSE-2.0
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 *------------------------------------------------------------------
19 #include <linux/if_packet.h>
20 #include <linux/virtio_net.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>
29 #include <vnet/devices/af_packet/af_packet.h>
31 #define foreach_af_packet_input_error
35 #define _(f,s) AF_PACKET_INPUT_ERROR_##f,
36 foreach_af_packet_input_error
38 AF_PACKET_INPUT_N_ERROR,
39 } af_packet_input_error_t;
41 static char *af_packet_input_error_strings[] = {
43 foreach_af_packet_input_error
52 struct tpacket2_hdr tph;
53 } af_packet_input_trace_t;
56 format_af_packet_input_trace (u8 * s, va_list * args)
58 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
59 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
60 af_packet_input_trace_t *t = va_arg (*args, af_packet_input_trace_t *);
61 u32 indent = format_get_indent (s);
63 s = format (s, "af_packet: hw_if_index %d next-index %d",
64 t->hw_if_index, t->next_index);
68 "\n%Utpacket2_hdr:\n%Ustatus 0x%x len %u snaplen %u mac %u net %u"
69 "\n%Usec 0x%x nsec 0x%x vlan %U"
70 #ifdef TP_STATUS_VLAN_TPID_VALID
74 format_white_space, indent + 2,
75 format_white_space, indent + 4,
81 format_white_space, indent + 4,
83 t->tph.tp_nsec, format_ethernet_vlan_tci, t->tph.tp_vlan_tci
84 #ifdef TP_STATUS_VLAN_TPID_VALID
92 buffer_add_to_chain (vlib_main_t * vm, u32 bi, u32 first_bi, u32 prev_bi)
94 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
95 vlib_buffer_t *first_b = vlib_get_buffer (vm, first_bi);
96 vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_bi);
98 /* update first buffer */
99 first_b->total_length_not_including_first_buffer += b->current_length;
101 /* update previous buffer */
102 prev_b->next_buffer = bi;
103 prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
105 /* update current buffer */
110 af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
111 vlib_frame_t * frame, af_packet_if_t * apif)
113 af_packet_main_t *apm = &af_packet_main;
114 struct tpacket2_hdr *tph;
115 u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
119 u32 n_rx_packets = 0;
122 u32 block_size = apif->rx_req->tp_block_size;
123 u32 frame_size = apif->rx_req->tp_frame_size;
124 u32 frame_num = apif->rx_req->tp_frame_nr;
125 u8 *block_start = apif->rx_ring + block * block_size;
126 uword n_trace = vlib_get_trace_count (vm, node);
127 u32 thread_index = vlib_get_thread_index ();
128 u32 n_buffer_bytes = vlib_buffer_free_list_buffer_size (vm,
129 VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
130 u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes;
132 if (apif->per_interface_next_index != ~0)
133 next_index = apif->per_interface_next_index;
135 n_free_bufs = vec_len (apm->rx_buffers[thread_index]);
136 if (PREDICT_FALSE (n_free_bufs < VLIB_FRAME_SIZE))
138 vec_validate (apm->rx_buffers[thread_index],
139 VLIB_FRAME_SIZE + n_free_bufs - 1);
141 vlib_buffer_alloc (vm, &apm->rx_buffers[thread_index][n_free_bufs],
143 _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs;
146 rx_frame = apif->next_rx_frame;
147 tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
148 while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
150 vlib_buffer_t *b0 = 0, *first_b0 = 0;
151 u32 next0 = next_index;
154 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
155 while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) &&
159 struct virtio_net_hdr *vh =
160 (struct virtio_net_hdr *) (((u8 *) tph) + tph->tp_mac -
161 sizeof (struct virtio_net_hdr));
162 u32 data_len = tph->tp_snaplen;
164 u32 bi0 = 0, first_bi0 = 0, prev_bi0;
167 u16 *wsum_addr = NULL;
168 u32 do_vnet = apm->flags & AF_PACKET_USES_VNET_HEADERS;
169 u32 do_csum = tph->tp_status & TP_STATUS_CSUMNOTREADY;
173 /* grab free buffer */
174 u32 last_empty_buffer =
175 vec_len (apm->rx_buffers[thread_index]) - 1;
177 bi0 = apm->rx_buffers[thread_index][last_empty_buffer];
178 b0 = vlib_get_buffer (vm, bi0);
179 _vec_len (apm->rx_buffers[thread_index]) = last_empty_buffer;
184 data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
185 u32 bytes_copied = 0;
186 b0->current_data = 0;
187 /* Kernel removes VLAN headers, so reconstruct VLAN */
188 if (PREDICT_FALSE (tph->tp_status & TP_STATUS_VLAN_VALID))
190 if (PREDICT_TRUE (offset == 0))
192 clib_memcpy (vlib_buffer_get_current (b0),
193 (u8 *) tph + tph->tp_mac,
194 sizeof (ethernet_header_t));
195 ethernet_header_t *eth = vlib_buffer_get_current (b0);
196 ethernet_vlan_header_t *vlan =
197 (ethernet_vlan_header_t *) (eth + 1);
198 vlan->priority_cfi_and_id =
199 clib_host_to_net_u16 (tph->tp_vlan_tci);
200 vlan->type = eth->type;
201 eth->type = clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
202 vlan_len = sizeof (ethernet_vlan_header_t);
203 bytes_copied = sizeof (ethernet_header_t);
206 /* Check if the incoming skb is marked as CSUM_PARTIAL,
207 * If VNET Headers are enabled TP_STATUS_CSUMNOTREADY is
208 * equivalent to the vnet csum flag.
210 if (PREDICT_TRUE ((do_vnet != 0) && (do_csum != 0)))
212 wsum_addr = (u16 *) (((u8 *) vlib_buffer_get_current (b0)) +
213 vlan_len + vh->csum_start +
215 if (bytes_copied <= vh->csum_start)
217 clib_memcpy (((u8 *) vlib_buffer_get_current (b0)) +
218 bytes_copied + vlan_len,
219 (u8 *) tph + tph->tp_mac + offset +
221 (vh->csum_start - bytes_copied));
223 ip_csum_and_memcpy (wsum,
225 vlib_buffer_get_current (b0)) +
226 vh->csum_start + vlan_len,
227 (u8 *) tph + tph->tp_mac +
228 offset + vh->csum_start,
229 (bytes_to_copy - vh->csum_start));
234 ip_csum_and_memcpy (wsum,
236 vlib_buffer_get_current (b0)) +
237 bytes_copied + vlan_len,
238 (u8 *) tph + tph->tp_mac +
239 offset + bytes_copied,
240 (bytes_to_copy - bytes_copied));
245 clib_memcpy (((u8 *) vlib_buffer_get_current (b0)) +
246 bytes_copied + vlan_len,
247 (u8 *) tph + tph->tp_mac + offset +
248 bytes_copied, (bytes_to_copy - bytes_copied));
251 /* fill buffer header */
252 b0->current_length = bytes_to_copy + vlan_len;
256 b0->total_length_not_including_first_buffer = 0;
257 b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
258 vnet_buffer (b0)->sw_if_index[VLIB_RX] = apif->sw_if_index;
259 vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
261 first_b0 = vlib_get_buffer (vm, first_bi0);
264 buffer_add_to_chain (vm, bi0, first_bi0, prev_bi0);
266 offset += bytes_to_copy;
267 data_len -= bytes_to_copy;
269 if (PREDICT_TRUE ((do_vnet != 0) && (do_csum != 0)))
271 *wsum_addr = ~ip_csum_fold (wsum);
274 n_rx_bytes += tph->tp_snaplen;
275 to_next[0] = first_bi0;
280 VLIB_BUFFER_TRACE_TRAJECTORY_INIT (first_b0);
281 if (PREDICT_FALSE (n_trace > 0))
283 af_packet_input_trace_t *tr;
284 vlib_trace_buffer (vm, node, next0, first_b0, /* follow_chain */
286 vlib_set_trace_count (vm, node, --n_trace);
287 tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
288 tr->next_index = next0;
289 tr->hw_if_index = apif->hw_if_index;
290 clib_memcpy (&tr->tph, tph, sizeof (struct tpacket2_hdr));
293 /* redirect if feature path enabled */
294 vnet_feature_start_device_input_x1 (apif->sw_if_index, &next0, b0);
296 /* enque and take next packet */
297 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
298 n_left_to_next, first_bi0, next0);
301 tph->tp_status = TP_STATUS_KERNEL;
302 rx_frame = (rx_frame + 1) % frame_num;
303 tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
306 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
309 apif->next_rx_frame = rx_frame;
311 vlib_increment_combined_counter
312 (vnet_get_main ()->interface_main.combined_sw_if_counters
313 + VNET_INTERFACE_COUNTER_RX,
314 vlib_get_thread_index (), apif->hw_if_index, n_rx_packets, n_rx_bytes);
316 vnet_device_increment_rx_packets (thread_index, n_rx_packets);
321 af_packet_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
322 vlib_frame_t * frame)
324 u32 n_rx_packets = 0;
325 af_packet_main_t *apm = &af_packet_main;
326 vnet_device_input_runtime_t *rt = (void *) node->runtime_data;
327 vnet_device_and_queue_t *dq;
329 foreach_device_and_queue (dq, rt->devices_and_queues)
331 af_packet_if_t *apif;
332 apif = vec_elt_at_index (apm->interfaces, dq->dev_instance);
333 if (apif->is_admin_up)
334 n_rx_packets += af_packet_device_input_fn (vm, node, frame, apif);
341 VLIB_REGISTER_NODE (af_packet_input_node) = {
342 .function = af_packet_input_fn,
343 .name = "af-packet-input",
344 .sibling_of = "device-input",
345 .format_trace = format_af_packet_input_trace,
346 .type = VLIB_NODE_TYPE_INPUT,
347 .state = VLIB_NODE_STATE_INTERRUPT,
348 .n_errors = AF_PACKET_INPUT_N_ERROR,
349 .error_strings = af_packet_input_error_strings,
352 VLIB_NODE_FUNCTION_MULTIARCH (af_packet_input_node, af_packet_input_fn)
357 * fd.io coding-style-patch-verification: ON
360 * eval: (c-set-style "gnu")