ovs-vsctl add-port br eth1
kernel side:
Register a generic netlink
Call function when receive command by netlink from userspace (ovs-vsctl)
Use the interface name to get the net_device
Register the send and receive event handler.
Register generic netlink 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 static struct genl_ops dp_vport_genl_ops [] = { { .cmd = OVS_VPORT_CMD_NEW, .flags = GENL_ADMIN_PERM, .policy = vport_policy, .doit = ovs_vport_cmd_new }, { .cmd = OVS_VPORT_CMD_DEL, .flags = GENL_ADMIN_PERM, .policy = vport_policy, .doit = ovs_vport_cmd_del }, { .cmd = OVS_VPORT_CMD_GET, .flags = 0 , .policy = vport_policy, .doit = ovs_vport_cmd_get, .dumpit = ovs_vport_cmd_dump }, { .cmd = OVS_VPORT_CMD_SET, .flags = GENL_ADMIN_PERM, .policy = vport_policy, .doit = ovs_vport_cmd_set, }, };
從netlink收到 OVS_VPORT_CMD_NEW 的cmd時，就會執行 ovs_vport_cmd_new
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 static int ovs_vport_cmd_new (struct sk_buff *skb, struct genl_info *info) struct nlattr **a = info ->attrs ; struct ovs_header *ovs_header = info ->userhdr ; struct vport_parms parms ; struct sk_buff *reply ; struct vport *vport ; struct datapath *dp ; u32 port_no; int err; err = -EINVAL; if (!a[OVS_VPORT_ATTR_NAME] || !a[OVS_VPORT_ATTR_TYPE] || !a[OVS_VPORT_ATTR_UPCALL_PID]) goto exit ; ovs_lock(); dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex); err = -ENODEV; if (!dp) goto exit_unlock; if (a[OVS_VPORT_ATTR_PORT_NO]) { port_no = nla_get_u32(a[OVS_VPORT_ATTR_PORT_NO]); err = -EFBIG; if (port_no >= DP_MAX_PORTS) goto exit_unlock; vport = ovs_vport_ovsl(dp, port_no); err = -EBUSY; if (vport) goto exit_unlock; } else { for (port_no = 1 ; ; port_no++) { if (port_no >= DP_MAX_PORTS) { err = -EFBIG; goto exit_unlock; } vport = ovs_vport_ovsl(dp, port_no); if (!vport) break ; } } parms.name = nla_data(a[OVS_VPORT_ATTR_NAME]); parms.type = nla_get_u32(a[OVS_VPORT_ATTR_TYPE]); parms.options = a[OVS_VPORT_ATTR_OPTIONS]; parms.dp = dp; parms.port_no = port_no; parms.upcall_portid = nla_get_u32(a[OVS_VPORT_ATTR_UPCALL_PID]); vport = new_vport(&parms); err = PTR_ERR(vport); if (IS_ERR(vport)) goto exit_unlock; err = 0 ; if (a[OVS_VPORT_ATTR_STATS]) ovs_vport_set_stats(vport, nla_data(a[OVS_VPORT_ATTR_STATS])); reply = ovs_vport_cmd_build_info(vport, info->snd_portid, info->snd_seq, OVS_VPORT_CMD_NEW); if (IS_ERR(reply)) { err = PTR_ERR(reply); ovs_dp_detach_port(vport); goto exit_unlock; } ovs_notify(reply, info, &ovs_dp_vport_multicast_group); exit_unlock: ovs_unlock(); exit : return err; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 static struct vport *new_vport (const struct vport_parms *parms) struct vport *vport ; vport = ovs_vport_add(parms); if (!IS_ERR(vport)) { struct datapath *dp = parms ->dp ; struct hlist_head *head = vport_hash_bucket (dp , vport ->port_no ); hlist_add_head_rcu(&vport->dp_hash_node, head); } return vport; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 struct vport *ovs_vport_add (const struct vport_parms *parms) struct vport *vport ; int err = 0 ; int i; for (i = 0 ; i < ARRAY_SIZE(vport_ops_list); i++) { if (vport_ops_list[i]->type == parms->type) { struct hlist_head *bucket ; vport = vport_ops_list[i]->create(parms); if (IS_ERR(vport)) { err = PTR_ERR(vport); goto out; } bucket = hash_bucket(ovs_dp_get_net(vport->dp), vport->ops->get_name(vport)); hlist_add_head_rcu(&vport->hash_node, bucket); return vport; } } err = -EAFNOSUPPORT; out: return ERR_PTR(err); }
這邊會執行 vport_ops_list[i]->create(parms)
1 2 3 4 5 6 7 8 9 10 11 12 static const struct vport_ops *vport_ops_list [] = { &ovs_netdev_vport_ops, &ovs_internal_vport_ops, #if IS_ENABLED(CONFIG_NET_IPGRE_DEMUX) &ovs_gre_vport_ops, &ovs_gre64_vport_ops, #endif &ovs_vxlan_vport_ops, &ovs_lisp_vport_ops, };
假設是個netdev的port,就會執行 ovs_netdev_vport_ops 裡面的create
1 2 3 4 5 6 7 8 const struct vport_ops ovs_netdev_vport_ops = { .type = OVS_VPORT_TYPE_NETDEV, .create = netdev_create, .destroy = netdev_destroy, .get_name = ovs_netdev_get_name, .send = netdev_send, };
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 static struct vport *netdev_create (const struct vport_parms *parms) struct vport *vport ; struct netdev_vport *netdev_vport ; int err; vport = ovs_vport_alloc(sizeof (struct netdev_vport), &ovs_netdev_vport_ops, parms); if (IS_ERR(vport)) { err = PTR_ERR(vport); goto error; } netdev_vport = netdev_vport_priv(vport); netdev_vport->dev = dev_get_by_name(ovs_dp_get_net(vport->dp), parms->name); if (!netdev_vport->dev) { err = -ENODEV; goto error_free_vport; } if (netdev_vport->dev->flags & IFF_LOOPBACK || netdev_vport->dev->type != ARPHRD_ETHER || ovs_is_internal_dev(netdev_vport->dev)) { err = -EINVAL; goto error_put; } rtnl_lock(); err = netdev_master_upper_dev_link(netdev_vport->dev, get_dpdev(vport->dp)); if (err) goto error_unlock; err = netdev_rx_handler_register(netdev_vport->dev, netdev_frame_hook, vport); if (err) goto error_master_upper_dev_unlink; dev_set_promiscuity(netdev_vport->dev, 1 ); netdev_vport->dev->priv_flags |= IFF_OVS_DATAPATH; rtnl_unlock(); netdev_init(); return vport; error_master_upper_dev_unlink: netdev_upper_dev_unlink(netdev_vport->dev, get_dpdev(vport->dp)); error_unlock: rtnl_unlock(); error_put: dev_put(netdev_vport->dev); error_free_vport: ovs_vport_free(vport); error: return ERR_PTR(err); }
這邊會調用 dev_get_by_name 用該name取得對應的device.
調用 netdev_rx_handler_register 註冊 rx handler.
userspace side:
個人資訊 我目前於 Hiskio 平台上面有開設 Kubernetes 相關課程，歡迎有興趣的人參考並分享，裡面有我從底層到實戰中對於 Kubernetes 的各種想法
線上課程詳細資訊: https://course.hwchiu.com/ https://www.facebook.com/technologynoteniu
如果有使用 Telegram 的也可以訂閱下列頻道來，裡面我會定期推播通知各類文章https://t.me/technologynote
你的捐款將給予我文章成長的動力
