/* *------------------------------------------------------------------ * af_packet.c - linux kernel packet interface * * Copyright (c) 2016 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. *------------------------------------------------------------------ */ #include <linux/if_packet.h> #include <vlib/vlib.h> #include <vlib/unix/unix.h> #include <vnet/ip/ip.h> #include <vnet/ethernet/ethernet.h> #include <vnet/devices/devices.h> #include <vnet/feature/feature.h> #include <vnet/ethernet/packet.h> #include <vnet/devices/af_packet/af_packet.h> #define foreach_af_packet_input_error \ _(PARTIAL_PKT, "partial packet") typedef enum { #define _(f,s) AF_PACKET_INPUT_ERROR_##f, foreach_af_packet_input_error #undef _ AF_PACKET_INPUT_N_ERROR, } af_packet_input_error_t; static char *af_packet_input_error_strings[] = { #define _(n,s) s, foreach_af_packet_input_error #undef _ }; typedef struct { u32 next_index; u32 hw_if_index; int block; struct tpacket2_hdr tph; } af_packet_input_trace_t; static u8 * format_af_packet_input_trace (u8 * s, va_list * args) { CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); af_packet_input_trace_t *t = va_arg (*args, af_packet_input_trace_t *); u32 indent = format_get_indent (s); s = format (s, "af_packet: hw_if_index %d next-index %d", t->hw_if_index, t->next_index); s = format (s, "\n%Utpacket2_hdr:\n%Ustatus 0x%x len %u snaplen %u mac %u net %u" "\n%Usec 0x%x nsec 0x%x vlan %U" #ifdef TP_STATUS_VLAN_TPID_VALID " vlan_tpid %u" #endif , format_white_space, indent + 2, format_white_space, indent + 4, t->tph.tp_status, t->tph.tp_len, t->tph.tp_snaplen, t->tph.tp_mac, t->tph.tp_net, format_white_space, indent + 4, t->tph.tp_sec, t->tph.tp_nsec, format_ethernet_vlan_tci, t->tph.tp_vlan_tci #ifdef TP_STATUS_VLAN_TPID_VALID , t->tph.tp_vlan_tpid #endif ); return s; } always_inline void buffer_add_to_chain (vlib_main_t * vm, u32 bi, u32 first_bi, u32 prev_bi) { vlib_buffer_t *b = vlib_get_buffer (vm, bi); vlib_buffer_t *first_b = vlib_get_buffer (vm, first_bi); vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_bi); /* update first buffer */ first_b->total_length_not_including_first_buffer += b->current_length; /* update previous buffer */ prev_b->next_buffer = bi; prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT; /* update current buffer */ b->next_buffer = 0; } static_always_inline void mark_tcp_udp_cksum_calc (vlib_buffer_t * b) { ethernet_header_t *eth = vlib_buffer_get_current (b); if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP4) { ip4_header_t *ip4 = (vlib_buffer_get_current (b) + sizeof (ethernet_header_t)); b->flags |= VNET_BUFFER_F_IS_IP4; if (ip4->protocol == IP_PROTOCOL_TCP) { b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM; ((tcp_header_t *) (vlib_buffer_get_current (b) + sizeof (ethernet_header_t) + ip4_header_bytes (ip4)))->checksum = 0; } else if (ip4->protocol == IP_PROTOCOL_UDP) { b->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM; ((udp_header_t *) (vlib_buffer_get_current (b) + sizeof (ethernet_header_t) + ip4_header_bytes (ip4)))->checksum = 0; } vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t); vnet_buffer (b)->l4_hdr_offset = sizeof (ethernet_header_t) + ip4_header_bytes (ip4); } else if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP6) { ip6_header_t *ip6 = (vlib_buffer_get_current (b) + sizeof (ethernet_header_t)); b->flags |= VNET_BUFFER_F_IS_IP6; u16 ip6_hdr_len = sizeof (ip6_header_t); if (ip6_ext_hdr (ip6->protocol)) { ip6_ext_header_t *p = (void *) (ip6 + 1); ip6_hdr_len += ip6_ext_header_len (p); while (ip6_ext_hdr (p->next_hdr)) { ip6_hdr_len += ip6_ext_header_len (p); p = ip6_ext_next_header (p); } } if (ip6->protocol == IP_PROTOCOL_TCP) { b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM; ((tcp_header_t *) (vlib_buffer_get_current (b) + sizeof (ethernet_header_t) + ip6_hdr_len))->checksum = 0; } else if (ip6->protocol == IP_PROTOCOL_UDP) { b->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM; ((udp_header_t *) (vlib_buffer_get_current (b) + sizeof (ethernet_header_t) + ip6_hdr_len))->checksum = 0; } vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t); vnet_buffer (b)->l4_hdr_offset = sizeof (ethernet_header_t) + ip6_hdr_len; } } always_inline uword af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame, af_packet_if_t * apif) { af_packet_main_t *apm = &af_packet_main; struct tpacket2_hdr *tph; u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT; u32 block = 0; u32 rx_frame; u32 n_free_bufs; u32 n_rx_packets = 0; u32 n_rx_bytes = 0; u32 *to_next = 0; u32 block_size = apif->rx_req->tp_block_size; u32 frame_size = apif->rx_req->tp_frame_size; u32 frame_num = apif->rx_req->tp_frame_nr; u8 *block_start = apif->rx_ring + block * block_size; uword n_trace = vlib_get_trace_count (vm, node); u32 thread_index = vm->thread_index; u32 n_buffer_bytes = vlib_buffer_get_default_data_size (vm); u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes; n_free_bufs = vec_len (apm->rx_buffers[thread_index]); if (PREDICT_FALSE (n_free_bufs < VLIB_FRAME_SIZE)) { vec_validate (apm->rx_buffers[thread_index], VLIB_FRAME_SIZE + n_free_bufs - 1); n_free_bufs += vlib_buffer_alloc (vm, &apm->rx_buffers[thread_index][n_free_bufs], VLIB_FRAME_SIZE); _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs; } rx_frame = apif->next_rx_frame; tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size); while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs)) { vlib_buffer_t *b0 = 0, *first_b0 = 0; u32 next0 = next_index; u32 n_left_to_next; vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) && n_left_to_next) { u32 data_len = tph->tp_snaplen; u32 offset = 0; u32 bi0 = 0, first_bi0 = 0, prev_bi0; while (data_len) { /* grab free buffer */ u32 last_empty_buffer = vec_len (apm->rx_buffers[thread_index]) - 1; prev_bi0 = bi0; bi0 = apm->rx_buffers[thread_index][last_empty_buffer]; b0 = vlib_get_buffer (vm, bi0); _vec_len (apm->rx_buffers[thread_index]) = last_empty_buffer; n_free_bufs--; /* copy data */ u32 bytes_to_copy = data_len > n_buffer_bytes ? n_buffer_bytes : data_len; u32 vlan_len = 0; u32 bytes_copied = 0; b0->current_data = 0; /* Kernel removes VLAN headers, so reconstruct VLAN */ if (PREDICT_FALSE (tph->tp_status & TP_STATUS_VLAN_VALID)) { if (PREDICT_TRUE (offset == 0)) { clib_memcpy_fast (vlib_buffer_get_current (b0), (u8 *) tph + tph->tp_mac, sizeof (ethernet_header_t)); ethernet_header_t *eth = vlib_buffer_get_current (b0); ethernet_vlan_header_t *vlan = (ethernet_vlan_header_t *) (eth + 1); vlan->priority_cfi_and_id = clib_host_to_net_u16 (tph->tp_vlan_tci); vlan->type = eth->type; eth->type = clib_host_to_net_u16 (ETHERNET_TYPE_VLAN); vlan_len = sizeof (ethernet_vlan_header_t); bytes_copied = sizeof (ethernet_header_t); } } clib_memcpy_fast (((u8 *) vlib_buffer_get_current (b0)) + bytes_copied + vlan_len, (u8 *) tph + tph->tp_mac + offset + bytes_copied, (bytes_to_copy - bytes_copied)); /* fill buffer header */ b0->current_length = bytes_to_copy + vlan_len; if (offset == 0) { b0->total_length_not_including_first_buffer = 0; b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID; vnet_buffer (b0)->sw_if_index[VLIB_RX] = apif->sw_if_index; vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0; first_bi0 = bi0; first_b0 = vlib_get_buffer (vm, first_bi0); if (tph->tp_status & TP_STATUS_CSUMNOTREADY) mark_tcp_udp_cksum_calc (first_b0); } else buffer_add_to_chain (vm, bi0, first_bi0, prev_bi0); offset += bytes_to_copy; data_len -= bytes_to_copy; } n_rx_packets++; n_rx_bytes += tph->tp_snaplen; to_next[0] = first_bi0; to_next += 1; n_left_to_next--; /* drop partial packets */ if (PREDICT_FALSE (tph->tp_len != tph->tp_snaplen)) { next0 = VNET_DEVICE_INPUT_NEXT_DROP; first_b0->error = node->errors[AF_PACKET_INPUT_ERROR_PARTIAL_PKT]; } else { next0 = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT; if (PREDICT_FALSE (apif->per_interface_next_index != ~0)) next0 = apif->per_interface_next_index; /* redirect if feature path enabled */ vnet_feature_start_device_input_x1 (apif->sw_if_index, &next0, first_b0); } /* trace */ VLIB_BUFFER_TRACE_TRAJECTORY_INIT (first_b0); if (PREDICT_FALSE (n_trace > 0)) { af_packet_input_trace_t *tr; vlib_trace_buffer (vm, node, next0, first_b0, /* follow_chain */ 0); vlib_set_trace_count (vm, node, --n_trace); tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr)); tr->next_index = next0; tr->hw_if_index = apif->hw_if_index; clib_memcpy_fast (&tr->tph, tph, sizeof (struct tpacket2_hdr)); } /* enque and take next packet */ vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, n_left_to_next, first_bi0, next0); /* next packet */ tph->tp_status = TP_STATUS_KERNEL; rx_frame = (rx_frame + 1) % frame_num; tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size); } vlib_put_next_frame (vm, node, next_index, n_left_to_next); } apif->next_rx_frame = rx_frame; vlib_increment_combined_counter (vnet_get_main ()->interface_main.combined_sw_if_counters + VNET_INTERFACE_COUNTER_RX, vlib_get_thread_index (), apif->hw_if_index, n_rx_packets, n_rx_bytes); vnet_device_increment_rx_packets (thread_index, n_rx_packets); return n_rx_packets; } VLIB_NODE_FN (af_packet_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { u32 n_rx_packets = 0; af_packet_main_t *apm = &af_packet_main; vnet_device_input_runtime_t *rt = (void *) node->runtime_data; vnet_device_and_queue_t *dq; foreach_device_and_queue (dq, rt->devices_and_queues) { af_packet_if_t *apif; apif = vec_elt_at_index (apm->interfaces, dq->dev_instance); if (apif->is_admin_up) n_rx_packets += af_packet_device_input_fn (vm, node, frame, apif); } return n_rx_packets; } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (af_packet_input_node) = { .name = "af-packet-input", .flags = VLIB_NODE_FLAG_TRACE_SUPPORTED, .sibling_of = "device-input", .format_trace = format_af_packet_input_trace, .type = VLIB_NODE_TYPE_INPUT, .state = VLIB_NODE_STATE_INTERRUPT, .n_errors = AF_PACKET_INPUT_N_ERROR, .error_strings = af_packet_input_error_strings, }; /* *INDENT-ON* */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */