2021-02-10 kernel network stack reading - Wireguard -

--- lang: ja breaks: false --- <style> .ui-infobar, #doc.markdown-body { max-width: 1100px; } </style> # 2021-02-10 kernel network stack reading - Wireguard - - 参加者: hayakawa, kawakami, saito - kernel: `5.6.6` - ドライバー: hayakawa - 今回のテーマ - Wireguardをざっくり見る ## 使用マシン - 早川のローカルマシンのVagrant - fedora/32-cloud-base ``` ip link add wg0 type wireguard ip addr add 192.168.0.1/24 man wg参照 ``` ``` ===Handshake TX 4985624133291 000 selinux_ipv4_output 4985624142556 000 ip_output 4985624146133 000 nf_hook_slow 4985624150341 000 selinux_ipv4_postroute 4985624154205 000 selinux_ip_postroute 4985624157426 000 ip_finish_output 4985624161130 000 __ip_finish_output 4985624164221 000 ip_finish_output2 4985624168615 000 neigh_resolve_output 4985624172064 000 __neigh_event_send 4985624176679 000 eth_header 4985624179588 000 skb_push 4985624183636 000 dev_queue_xmit 4985624186952 000 __dev_queue_xmit 4985624190527 000 netdev_core_pick_tx 4985624194371 000 validate_xmit_skb 4985624198345 000 netif_skb_features 4985624201689 000 passthru_features_check 4985624205135 000 skb_network_protocol 4985624209940 000 skb_csum_hwoffload_help 4985624213073 000 validate_xmit_xfrm 4985624216079 000 dev_hard_start_xmit 4985624220469 000 skb_clone_tx_timestamp 4985624224575 000 __dev_forward_skb 4985624227651 000 skb_scrub_packet ===Handshake RX 4985624244082 000 ip_rcv_finish 4985624248671 000 udp_v4_early_demux 4985624252170 000 ip_route_input_noref 4985624255377 000 ip_route_input_slow 4985624260790 000 fib_validate_source 4985624264720 000 __fib_validate_source 4985624269532 000 ip_local_deliver 4985624274017 000 ip_local_deliver_finish 4985624277121 000 ip_protocol_deliver_rcu 4985624280735 000 raw_local_deliver 4985624285044 000 udp_rcv 4985624289334 000 __udp4_lib_rcv 4985624294605 000 udp_unicast_rcv_skb 4985624298580 000 udp_queue_rcv_one_skb 4985624302069 000 wg_receive 4985624305798 000 wg_packet_receive 4985624309970 000 skb_pull 4985624313782 000 skb_queue_tail 4985624904181 000 wg_receive_handshake_packet 4985624911724 000 wg_cookie_validate_packet 4985625756857 000 consume_skb 4985625760528 000 skb_release_head_state 4985625763498 000 skb_release_data 4985625766836 000 kfree_skbmem === 4985623716785 000 selinux_ipv4_output 4985623737120 000 ip_output 4985623740486 000 nf_hook_slow 4985623745622 000 selinux_ipv4_postroute 4985623750072 000 selinux_ip_postroute 4985623753325 000 ip_finish_output 4985623757295 000 __cgroup_bpf_run_filter_skb 4985623761442 000 __ip_finish_output 4985623765143 000 ip_finish_output2 4985623769954 000 neigh_direct_output 4985623774536 000 dev_queue_xmit 4985623778172 000 __dev_queue_xmit 4985623781929 000 netdev_core_pick_tx 4985623788734 000 validate_xmit_skb 4985623793592 000 netif_skb_features 4985623797917 000 skb_network_protocol 4985623801527 000 validate_xmit_xfrm 4985623805470 000 dev_hard_start_xmit 4985623809396 000 wg_xmit 4985623813734 000 wg_allowedips_lookup_dst 4985623821044 000 sock_wfree 4985626202620 000 encrypt_packet 4985626210356 000 skb_cow_data 4985626213830 000 skb_push 4985626216976 000 pskb_put 4985626220632 000 skb_to_sgvec 4985626223886 000 __skb_to_sgvec 4985626228464 000 skb_scrub_packet === 4985626390817 000 selinux_ipv4_output 4985626396451 000 ip_output 4985626399618 000 nf_hook_slow 4985626402811 000 selinux_ipv4_postroute 4985626405845 000 selinux_ip_postroute 4985626408772 000 ip_finish_output 4985626411729 000 __ip_finish_output 4985626414630 000 ip_finish_output2 4985626418027 000 neigh_resolve_output 4985626421068 000 eth_header 4985626423949 000 skb_push 4985626427002 000 dev_queue_xmit 4985626429901 000 __dev_queue_xmit 4985626432987 000 netdev_core_pick_tx 4985626436661 000 validate_xmit_skb 4985626439713 000 netif_skb_features 4985626443018 000 passthru_features_check 4985626445905 000 skb_network_protocol 4985626449091 000 skb_csum_hwoffload_help 4985626451916 000 validate_xmit_xfrm 4985626454768 000 dev_hard_start_xmit 4985626458151 000 skb_clone_tx_timestamp 4985626461680 000 __dev_forward_skb 4985626464566 000 skb_scrub_packet === 4985626473220 000 ip_rcv_finish 4985626477417 000 udp_v4_early_demux 4985626480675 000 ip_route_input_noref 4985626483917 000 ip_route_input_slow 4985626487964 000 fib_validate_source 4985626491229 000 __fib_validate_source 4985626494822 000 ip_local_deliver 4985626497992 000 ip_local_deliver_finish 4985626500820 000 ip_protocol_deliver_rcu 4985626503766 000 raw_local_deliver 4985626507677 000 udp_rcv 4985626511472 000 __udp4_lib_rcv 4985626515468 000 udp_unicast_rcv_skb 4985626519131 000 udp_queue_rcv_one_skb 4985626522575 000 wg_receive 4985626526079 000 wg_packet_receive 4985626529831 000 skb_pull 4985626755100 000 decrypt_packet 4985626760491 000 skb_push 4985626763940 000 skb_cow_data 4985626767005 000 skb_pull 4985626770054 000 skb_to_sgvec 4985626772910 000 __skb_to_sgvec 4985626776883 000 skb_push 4985626779790 000 skb_pull 4985626783354 000 skb_scrub_packet === 4985625640284 000 selinux_ipv4_output 4985625650647 000 ip_output 4985625654542 000 nf_hook_slow 4985625658476 000 selinux_ipv4_postroute 4985625661792 000 selinux_ip_postroute 4985625664854 000 ip_finish_output 4985625668719 000 __ip_finish_output 4985625671820 000 ip_finish_output2 4985625675481 000 neigh_resolve_output 4985625678649 000 __neigh_event_send 4985625682663 000 eth_header 4985625685614 000 skb_push 4985625689191 000 dev_queue_xmit 4985625692111 000 __dev_queue_xmit 4985625695282 000 netdev_core_pick_tx 4985625699073 000 validate_xmit_skb 4985625702415 000 netif_skb_features 4985625705577 000 passthru_features_check 4985625708658 000 skb_network_protocol 4985625712344 000 skb_csum_hwoffload_help 4985625715647 000 validate_xmit_xfrm 4985625718525 000 dev_hard_start_xmit 4985625722045 000 skb_clone_tx_timestamp 4985625725699 000 __dev_forward_skb 4985625728898 000 skb_scrub_packet === 4985626997923 000 selinux_ipv4_output 4985627003446 000 ip_output 4985627006438 000 nf_hook_slow 4985627009509 000 selinux_ipv4_postroute 4985627012747 000 selinux_ip_postroute 4985627015677 000 ip_finish_output 4985627018708 000 __ip_finish_output 4985627021625 000 ip_finish_output2 4985627024894 000 neigh_resolve_output 4985627027895 000 eth_header 4985627030774 000 skb_push 4985627033734 000 dev_queue_xmit 4985627036602 000 __dev_queue_xmit 4985627039670 000 netdev_core_pick_tx 4985627043102 000 validate_xmit_skb 4985627046245 000 netif_skb_features 4985627049328 000 passthru_features_check 4985627052227 000 skb_network_protocol 4985627055433 000 skb_csum_hwoffload_help 4985627058313 000 validate_xmit_xfrm 4985627061163 000 dev_hard_start_xmit 4985627064450 000 skb_clone_tx_timestamp 4985627067741 000 __dev_forward_skb 4985627070592 000 skb_scrub_packet ``` ## メモ - Wireguardの初期化 - udp_tunnelを利用している - 初期化時にソケットを作ってudp_tunnelに登録 - udp_rcvの先でencap_rcv call backの有無でtunnelのパスと普通のudpの受信パスを分岐 - tunnelの場合はソケットのキューにデータは積まない、skbをそのまま渡す

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