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>
27 #include <vnet/devices/af_packet/af_packet.h>
29 #define foreach_af_packet_tx_func_error \
30 _(FRAME_NOT_READY, "tx frame not ready") \
31 _(TXRING_EAGAIN, "tx sendto temporary failure") \
32 _(TXRING_FATAL, "tx sendto fatal failure") \
33 _(TXRING_OVERRUN, "tx ring overrun")
36 #define _(f,s) AF_PACKET_TX_ERROR_##f,
37 foreach_af_packet_tx_func_error
40 } af_packet_tx_func_error_t;
42 static char * af_packet_tx_func_error_strings[] = {
44 foreach_af_packet_tx_func_error
49 static u8 * format_af_packet_device_name (u8 * s, va_list * args)
51 u32 i = va_arg (*args, u32);
52 af_packet_main_t * apm = &af_packet_main;
53 af_packet_if_t * apif = pool_elt_at_index (apm->interfaces, i);
55 s = format (s, "host-%s", apif->host_if_name);
59 static u8 * format_af_packet_device (u8 * s, va_list * args)
61 s = format (s, "Linux PACKET socket interface");
65 static u8 * format_af_packet_tx_trace (u8 * s, va_list * args)
67 s = format (s, "Unimplemented...");
72 af_packet_interface_tx (vlib_main_t * vm,
73 vlib_node_runtime_t * node,
76 af_packet_main_t * apm = &af_packet_main;
77 u32 * buffers = vlib_frame_args (frame);
78 u32 n_left = frame->n_vectors;
80 vnet_interface_output_runtime_t * rd = (void *) node->runtime_data;
81 af_packet_if_t * apif = pool_elt_at_index (apm->interfaces, rd->dev_instance);
83 u32 block_size = apif->tx_req->tp_block_size;
84 u32 frame_size = apif->tx_req->tp_frame_size;
85 u32 frame_num = apif->tx_req->tp_frame_nr;
86 u8 * block_start = apif->tx_ring + block * block_size;
87 u32 tx_frame = apif->next_tx_frame;
88 struct tpacket2_hdr * tph;
89 u32 frame_not_ready = 0;
100 tph = (struct tpacket2_hdr *) (block_start + tx_frame * frame_size);
102 if (PREDICT_FALSE(tph->tp_status & (TP_STATUS_SEND_REQUEST | TP_STATUS_SENDING)))
110 b0 = vlib_get_buffer (vm, bi);
111 len = b0->current_length;
112 clib_memcpy((u8 *) tph + TPACKET_ALIGN(sizeof(struct tpacket2_hdr)) + offset,
113 vlib_buffer_get_current(b0), len);
116 while ((bi = b0->next_buffer));
118 tph->tp_len = tph->tp_snaplen = offset;
119 tph->tp_status = TP_STATUS_SEND_REQUEST;
122 /* check if we've exhausted the ring */
123 if (PREDICT_FALSE(frame_not_ready + n_sent == frame_num))
126 tx_frame = (tx_frame + 1) % frame_num;
129 CLIB_MEMORY_BARRIER();
131 if (PREDICT_TRUE(n_sent))
133 apif->next_tx_frame = tx_frame;
135 if (PREDICT_FALSE(sendto(apif->fd, NULL, 0,
136 MSG_DONTWAIT, NULL, 0) == -1))
138 /* Uh-oh, drop & move on, but count whether it was fatal or not.
139 * Note that we have no reliable way to properly determine the
140 * disposition of the packets we just enqueued for delivery.
142 vlib_error_count (vm, node->node_index,
143 unix_error_is_fatal(errno) ?
144 AF_PACKET_TX_ERROR_TXRING_FATAL :
145 AF_PACKET_TX_ERROR_TXRING_EAGAIN,
150 if (PREDICT_FALSE(frame_not_ready))
151 vlib_error_count (vm, node->node_index, AF_PACKET_TX_ERROR_FRAME_NOT_READY,
154 if (PREDICT_FALSE(frame_not_ready + n_sent == frame_num))
155 vlib_error_count (vm, node->node_index, AF_PACKET_TX_ERROR_TXRING_OVERRUN,
158 vlib_buffer_free (vm, vlib_frame_args (frame), frame->n_vectors);
159 return frame->n_vectors;
163 af_packet_set_interface_next_node (vnet_main_t *vnm, u32 hw_if_index,
166 af_packet_main_t * apm = &af_packet_main;
167 vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
168 af_packet_if_t * apif = pool_elt_at_index (apm->interfaces, hw->dev_instance);
170 /* Shut off redirection */
171 if (node_index == ~0)
173 apif->per_interface_next_index = node_index;
177 apif->per_interface_next_index =
178 vlib_node_add_next (vlib_get_main(), af_packet_input_node.index, node_index);
181 static void af_packet_clear_hw_interface_counters (u32 instance)
183 /* Nothing for now */
186 static clib_error_t *
187 af_packet_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
189 af_packet_main_t * apm = &af_packet_main;
190 vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
191 af_packet_if_t * apif = pool_elt_at_index (apm->interfaces, hw->dev_instance);
194 apif->is_admin_up = (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) != 0;
196 if (apif->is_admin_up)
197 hw_flags = VNET_HW_INTERFACE_FLAG_LINK_UP;
201 vnet_hw_interface_set_flags(vnm, hw_if_index, hw_flags);
206 static clib_error_t *
207 af_packet_subif_add_del_function (vnet_main_t * vnm,
209 struct vnet_sw_interface_t * st,
212 /* Nothing for now */
216 VNET_DEVICE_CLASS (af_packet_device_class) = {
218 .tx_function = af_packet_interface_tx,
219 .format_device_name = format_af_packet_device_name,
220 .format_device = format_af_packet_device,
221 .format_tx_trace = format_af_packet_tx_trace,
222 .tx_function_n_errors = AF_PACKET_TX_N_ERROR,
223 .tx_function_error_strings = af_packet_tx_func_error_strings,
224 .rx_redirect_to_node = af_packet_set_interface_next_node,
225 .clear_counters = af_packet_clear_hw_interface_counters,
226 .admin_up_down_function = af_packet_interface_admin_up_down,
227 .subif_add_del_function = af_packet_subif_add_del_function,
228 .no_flatten_output_chains = 1,
231 VLIB_DEVICE_TX_FUNCTION_MULTIARCH (af_packet_device_class,
232 af_packet_interface_tx)