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/feature/feature.h>
28 #include <vnet/devices/af_packet/af_packet.h>
30 #define foreach_af_packet_input_error
34 #define _(f,s) AF_PACKET_INPUT_ERROR_##f,
35 foreach_af_packet_input_error
37 AF_PACKET_INPUT_N_ERROR,
38 } af_packet_input_error_t;
40 static char *af_packet_input_error_strings[] = {
42 foreach_af_packet_input_error
48 AF_PACKET_INPUT_NEXT_DROP,
49 AF_PACKET_INPUT_NEXT_ETHERNET_INPUT,
50 AF_PACKET_INPUT_N_NEXT,
58 struct tpacket2_hdr tph;
59 } af_packet_input_trace_t;
62 format_af_packet_input_trace (u8 * s, va_list * args)
64 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
65 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
66 af_packet_input_trace_t *t = va_arg (*args, af_packet_input_trace_t *);
67 uword indent = format_get_indent (s);
69 s = format (s, "af_packet: hw_if_index %d next-index %d",
70 t->hw_if_index, t->next_index);
74 "\n%Utpacket2_hdr:\n%Ustatus 0x%x len %u snaplen %u mac %u net %u"
75 "\n%Usec 0x%x nsec 0x%x vlan %U"
76 #ifdef TP_STATUS_VLAN_TPID_VALID
80 format_white_space, indent + 2,
81 format_white_space, indent + 4,
87 format_white_space, indent + 4,
89 t->tph.tp_nsec, format_ethernet_vlan_tci, t->tph.tp_vlan_tci
90 #ifdef TP_STATUS_VLAN_TPID_VALID
98 buffer_add_to_chain (vlib_main_t * vm, u32 bi, u32 first_bi, u32 prev_bi)
100 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
101 vlib_buffer_t *first_b = vlib_get_buffer (vm, first_bi);
102 vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_bi);
104 /* update first buffer */
105 first_b->total_length_not_including_first_buffer += b->current_length;
107 /* update previous buffer */
108 prev_b->next_buffer = bi;
109 prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
111 /* update current buffer */
115 struct rte_mbuf *mbuf = rte_mbuf_from_vlib_buffer (b);
116 struct rte_mbuf *first_mbuf = rte_mbuf_from_vlib_buffer (first_b);
117 struct rte_mbuf *prev_mbuf = rte_mbuf_from_vlib_buffer (prev_b);
118 first_mbuf->nb_segs++;
119 prev_mbuf->next = mbuf;
120 mbuf->data_len = b->current_length;
121 mbuf->data_off = RTE_PKTMBUF_HEADROOM + b->current_data;
127 af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
128 vlib_frame_t * frame, u32 device_idx)
130 af_packet_main_t *apm = &af_packet_main;
131 af_packet_if_t *apif = pool_elt_at_index (apm->interfaces, device_idx);
132 struct tpacket2_hdr *tph;
133 u32 next_index = AF_PACKET_INPUT_NEXT_ETHERNET_INPUT;
137 u32 n_rx_packets = 0;
140 u32 block_size = apif->rx_req->tp_block_size;
141 u32 frame_size = apif->rx_req->tp_frame_size;
142 u32 frame_num = apif->rx_req->tp_frame_nr;
143 u8 *block_start = apif->rx_ring + block * block_size;
144 uword n_trace = vlib_get_trace_count (vm, node);
145 u32 n_buffer_bytes = vlib_buffer_free_list_buffer_size (vm,
146 VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
147 u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes;
148 int cpu_index = node->cpu_index;
150 if (apif->per_interface_next_index != ~0)
151 next_index = apif->per_interface_next_index;
153 n_free_bufs = vec_len (apm->rx_buffers[cpu_index]);
154 if (PREDICT_FALSE (n_free_bufs < VLIB_FRAME_SIZE))
156 vec_validate (apm->rx_buffers[cpu_index],
157 VLIB_FRAME_SIZE + n_free_bufs - 1);
159 vlib_buffer_alloc (vm, &apm->rx_buffers[cpu_index][n_free_bufs],
161 _vec_len (apm->rx_buffers[cpu_index]) = n_free_bufs;
164 rx_frame = apif->next_rx_frame;
165 tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
166 while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
168 vlib_buffer_t *b0 = 0, *first_b0 = 0;
169 u32 next0 = next_index;
172 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
173 while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) &&
176 u32 data_len = tph->tp_snaplen;
178 u32 bi0 = 0, first_bi0 = 0, prev_bi0;
182 /* grab free buffer */
183 u32 last_empty_buffer =
184 vec_len (apm->rx_buffers[cpu_index]) - 1;
186 bi0 = apm->rx_buffers[cpu_index][last_empty_buffer];
187 b0 = vlib_get_buffer (vm, bi0);
188 _vec_len (apm->rx_buffers[cpu_index]) = last_empty_buffer;
193 data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
194 b0->current_data = 0;
195 clib_memcpy (vlib_buffer_get_current (b0),
196 (u8 *) tph + tph->tp_mac + offset, bytes_to_copy);
198 /* fill buffer header */
199 b0->current_length = bytes_to_copy;
204 struct rte_mbuf *mb = rte_mbuf_from_vlib_buffer (b0);
205 rte_pktmbuf_data_len (mb) = b0->current_length;
206 rte_pktmbuf_pkt_len (mb) = b0->current_length;
208 b0->total_length_not_including_first_buffer = 0;
209 b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
210 vnet_buffer (b0)->sw_if_index[VLIB_RX] = apif->sw_if_index;
211 vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
213 first_b0 = vlib_get_buffer (vm, first_bi0);
216 buffer_add_to_chain (vm, bi0, first_bi0, prev_bi0);
218 offset += bytes_to_copy;
219 data_len -= bytes_to_copy;
222 n_rx_bytes += tph->tp_snaplen;
223 to_next[0] = first_bi0;
228 VLIB_BUFFER_TRACE_TRAJECTORY_INIT (first_b0);
229 if (PREDICT_FALSE (n_trace > 0))
231 af_packet_input_trace_t *tr;
232 vlib_trace_buffer (vm, node, next0, first_b0, /* follow_chain */
234 vlib_set_trace_count (vm, node, --n_trace);
235 tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
236 tr->next_index = next0;
237 tr->hw_if_index = apif->hw_if_index;
238 clib_memcpy (&tr->tph, tph, sizeof (struct tpacket2_hdr));
241 /* redirect if feature path enabled */
242 vnet_feature_device_input_redirect_x1 (node, apif->sw_if_index,
245 /* enque and take next packet */
246 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
247 n_left_to_next, first_bi0, next0);
250 tph->tp_status = TP_STATUS_KERNEL;
251 rx_frame = (rx_frame + 1) % frame_num;
252 tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
255 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
258 apif->next_rx_frame = rx_frame;
260 vlib_increment_combined_counter
261 (vnet_get_main ()->interface_main.combined_sw_if_counters
262 + VNET_INTERFACE_COUNTER_RX,
263 os_get_cpu_number (), apif->hw_if_index, n_rx_packets, n_rx_bytes);
269 af_packet_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
270 vlib_frame_t * frame)
273 u32 n_rx_packets = 0;
275 af_packet_main_t *apm = &af_packet_main;
278 clib_bitmap_foreach (i, apm->pending_input_bitmap,
280 clib_bitmap_set (apm->pending_input_bitmap, i, 0);
281 n_rx_packets += af_packet_device_input_fn(vm, node, frame, i);
289 VLIB_REGISTER_NODE (af_packet_input_node) = {
290 .function = af_packet_input_fn,
291 .name = "af-packet-input",
292 .format_trace = format_af_packet_input_trace,
293 .type = VLIB_NODE_TYPE_INPUT,
294 .state = VLIB_NODE_STATE_INTERRUPT,
295 .n_errors = AF_PACKET_INPUT_N_ERROR,
296 .error_strings = af_packet_input_error_strings,
298 .n_next_nodes = AF_PACKET_INPUT_N_NEXT,
300 [AF_PACKET_INPUT_NEXT_DROP] = "error-drop",
301 [AF_PACKET_INPUT_NEXT_ETHERNET_INPUT] = "ethernet-input",
305 VLIB_NODE_FUNCTION_MULTIARCH (af_packet_input_node, af_packet_input_fn)
310 * fd.io coding-style-patch-verification: ON
313 * eval: (c-set-style "gnu")