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Openvswitch原理与代码分析(2): ovs-vswitchd的启动

时间：2020-04-28 13:12:17      阅读：56      评论：0      收藏：0      [点我收藏+]

标签：current   pid   代码   conf   pes   https   ESS   ISE   dealloc   

https://www.cnblogs.com/popsuper1982/p/5851603.html

ovs-vswitchd.c的main函数最终会进入一个while循环，在这个无限循环中，里面最重要的两个函数是bridge_run()和netdev_run()。

 

技术图片

 

Openvswitch主要管理两种类型的设备，一个是创建的虚拟网桥，一个是连接到虚拟网桥上的设备。

 

其中bridge_run就是初始化数据库中已经创建的虚拟网桥。

 

一、虚拟网桥的初始化bridge_run

 

bridge_run会调用bridge_run__，bridge_run__中最重要的是对于所有的网桥，都调用ofproto_run

 

  1. static void
  2. bridge_run__(void)
  3. {
  4. ……
  5.     /* Let each bridge do the work that it needs to do. */
  6.     HMAP_FOR_EACH (br, node, &all_bridges) {
  7.         ofproto_run(br->ofproto);
  8.     }
  9. }

 

Int ofproto_run(struct ofproto *p)会调用error = p->ofproto_class->run(p);

 

ofproto_class的定义在ofproto-provider.h中，它的实现定义在ofproto-dpif.c中，这里面的所有的函数，在这个文件中都有定义。

 

  1. const struct ofproto_class ofproto_dpif_class = {
  2.     init,
  3.     enumerate_types,
  4.     enumerate_names,
  5.     del,
  6.     port_open_type,
  7.     type_run,
  8.     type_wait,
  9.     alloc,
  10.     construct,
  11.     destruct,
  12.     dealloc,
  13.     run,
  14.     wait,
  15.     NULL, /* get_memory_usage. */
  16.     type_get_memory_usage,
  17.     flush,
  18.     query_tables,
  19.     set_tables_version,
  20.     port_alloc,
  21.     port_construct,
  22.     port_destruct,
  23.     port_dealloc,
  24.     port_modified,
  25.     port_reconfigured,
  26.     port_query_by_name,
  27.     port_add,
  28.     port_del,
  29.     port_get_stats,
  30.     port_dump_start,
  31.     port_dump_next,
  32.     port_dump_done,
  33.     port_poll,
  34.     port_poll_wait,
  35.     port_is_lacp_current,
  36.     port_get_lacp_stats,
  37.     NULL, /* rule_choose_table */
  38.     rule_alloc,
  39.     rule_construct,
  40.     rule_insert,
  41.     rule_delete,
  42.     rule_destruct,
  43.     rule_dealloc,
  44.     rule_get_stats,
  45.     rule_execute,
  46.     set_frag_handling,
  47.     packet_out,
  48.     set_netflow,
  49.     get_netflow_ids,
  50.     set_sflow,
  51.     set_ipfix,
  52.     set_cfm,
  53.     cfm_status_changed,
  54.     get_cfm_status,
  55.     set_lldp,
  56.     get_lldp_status,
  57.     set_aa,
  58.     aa_mapping_set,
  59.     aa_mapping_unset,
  60.     aa_vlan_get_queued,
  61.     aa_vlan_get_queue_size,
  62.     set_bfd,
  63.     bfd_status_changed,
  64.     get_bfd_status,
  65.     set_stp,
  66.     get_stp_status,
  67.     set_stp_port,
  68.     get_stp_port_status,
  69.     get_stp_port_stats,
  70.     set_rstp,
  71.     get_rstp_status,
  72.     set_rstp_port,
  73.     get_rstp_port_status,
  74.     set_queues,
  75.     bundle_set,
  76.     bundle_remove,
  77.     mirror_set__,
  78.     mirror_get_stats__,
  79.     set_flood_vlans,
  80.     is_mirror_output_bundle,
  81.     forward_bpdu_changed,
  82.     set_mac_table_config,
  83.     set_mcast_snooping,
  84.     set_mcast_snooping_port,
  85.     set_realdev,
  86.     NULL, /* meter_get_features */
  87.     NULL, /* meter_set */
  88.     NULL, /* meter_get */
  89.     NULL, /* meter_del */
  90.     group_alloc, /* group_alloc */
  91.     group_construct, /* group_construct */
  92.     group_destruct, /* group_destruct */
  93.     group_dealloc, /* group_dealloc */
  94.     group_modify, /* group_modify */
  95.     group_get_stats, /* group_get_stats */
  96.     get_datapath_version, /* get_datapath_version */
  97. };

 

在ofproto-provider.h中注释里是这样说的。

这里定义了四类数据结构

Struct ofproto表示一个交换机

Struct ofport表示交换机上的一个端口

Struct rule表示交换机上的一条flow规则

Struct ofgroup表示一个flow规则组

 

上面说到启动的过程中，会调用ofproto_class->run，也即会调用ofproto-dpif.c中的static int run(struct ofproto *ofproto_)函数。

 

在这个函数中，会初始化netflow, sflow, ipfix，stp, rstp, mac address learning等一系列操作。

 

bridge_run还会调用static void bridge_reconfigure(const struct ovsrec_open_vswitch *ovs_cfg)，其中ovs_cfg是从ovsdb-server里面读取出来的配置。

 

在这个函数里面，对于每一个网桥，将网卡添加进去

  1. HMAP_FOR_EACH (br, node, &all_bridges) {
  2.     bridge_add_ports(br, &br->wanted_ports);
  3.     shash_destroy(&br->wanted_ports);
  4. }

 

  1. static void
  2. bridge_add_ports(struct bridge *br, const struct shash *wanted_ports)
  3. {
  4.     /* First add interfaces that request a particular port number. */
  5.     bridge_add_ports__(br, wanted_ports, true);
  6.  
  7.     /* Then add interfaces that want automatic port number assignment.
  8.      * We add these afterward to avoid accidentally taking a specifically
  9.      * requested port number. */
  10.     bridge_add_ports__(br, wanted_ports, false);
  11. }

 

static void bridge_add_ports__(struct bridge *br, const struct shash *wanted_ports, bool with_requested_port)会调用

static bool iface_create(struct bridge *br, const struct ovsrec_interface *iface_cfg, const struct ovsrec_port *port_cfg)会调用

static int iface_do_create(const struct bridge *br, const struct ovsrec_interface *iface_cfg, const struct ovsrec_port *port_cfg, ofp_port_t *ofp_portp, struct netdev **netdevp, char **errp)会调用

int ofproto_port_add(struct ofproto *ofproto, struct netdev *netdev, ofp_port_t *ofp_portp)会调用

 

  1. error = ofproto->ofproto_class->port_add(ofproto, netdev);

 

会调用ofproto-dpif.c中的ofproto_dpif_class的static int port_add(struct ofproto *ofproto_, struct netdev *netdev)函数。

 

会调用int dpif_port_add(struct dpif *dpif, struct netdev *netdev, odp_port_t *port_nop)会调用

 

  1. error = dpif->dpif_class->port_add(dpif, netdev, &port_no);

 

会调用dpif_netlink_class的port_add函数，也即dpif_netlink_port_add，也即

static int dpif_netlink_port_add(struct dpif *dpif_, struct netdev *netdev,odp_port_t *port_nop)会调用

static int dpif_netlink_port_add__(struct dpif_netlink *dpif, struct netdev *netdev, odp_port_t *port_nop)

 

在这个函数里面，会调用netlink的API，命令为OVS_VPORT_CMD_NEW

 

  1. const char *name = netdev_vport_get_dpif_port(netdev,
  2.                                                   namebuf, sizeof namebuf);
  3. struct dpif_netlink_vport request, reply;
  4. struct nl_sock **socksp = NULL;
  5.  
  6. if (dpif->handlers) {
  7.     socksp = vport_create_socksp(dpif, &error);
  8.     if (!socksp) {
  9.         return error;
  10.     }
  11. }
  12.  
  13. dpif_netlink_vport_init(&request);
  14. request.cmd = OVS_VPORT_CMD_NEW;
  15. request.dp_ifindex = dpif->dp_ifindex;
  16. request.type = netdev_to_ovs_vport_type(netdev);
  17.  
  18. request.name = name;
  19.  
  20. upcall_pids = vport_socksp_to_pids(socksp, dpif->n_handlers);
  21. request.n_upcall_pids = socksp ? dpif->n_handlers : 1;
  22. request.upcall_pids = upcall_pids;
  23. error = dpif_netlink_vport_transact(&request, &reply, &buf);

 

这里会调用内核模块openvswitch.ko，在内核中添加虚拟网卡。这部分详细的过程将在下一节分析。

二、虚拟网卡的初始化netdev_run()

 

  1. void
  2. netdev_run(void)
  3.     OVS_EXCLUDED(netdev_class_mutex, netdev_mutex)
  4. {
  5.     struct netdev_registered_class *rc;
  6.  
  7.     netdev_initialize();
  8.     ovs_mutex_lock(&netdev_class_mutex);
  9.     HMAP_FOR_EACH (rc, hmap_node, &netdev_classes) {
  10.         if (rc->class->run) {
  11.             rc->class->run();
  12.         }
  13.     }
  14.     ovs_mutex_unlock(&netdev_class_mutex);
  15. }

 

依次循环调用netdev_classes中的每一个run。

 

对于不同类型的虚拟网卡，都有对应的netdev_class。

 

例如对于dpdk的网卡有

 

  1. static const struct netdev_class dpdk_class =
  2.     NETDEV_DPDK_CLASS(
  3.         "dpdk",
  4.         NULL,
  5.         netdev_dpdk_construct,
  6.         netdev_dpdk_destruct,
  7.         netdev_dpdk_set_multiq,
  8.         netdev_dpdk_eth_send,
  9.         netdev_dpdk_get_carrier,
  10.         netdev_dpdk_get_stats,
  11.         netdev_dpdk_get_features,
  12.         netdev_dpdk_get_status,
  13.         netdev_dpdk_rxq_recv);

 

对于物理网卡，也需要有相应的netdev_class

 

  1. const struct netdev_class netdev_linux_class =
  2.     NETDEV_LINUX_CLASS(
  3.         "system",
  4.         netdev_linux_construct,
  5.         netdev_linux_get_stats,
  6.         netdev_linux_get_features,
  7.         netdev_linux_get_status);

 

对于连接到KVM的tap网卡

  1. const struct netdev_class netdev_tap_class =
  2.     NETDEV_LINUX_CLASS(
  3.         "tap",
  4.         netdev_linux_construct_tap,
  5.         netdev_tap_get_stats,
  6.         netdev_linux_get_features,
  7.         netdev_linux_get_status);

 

对于虚拟的软网卡，比如veth pair

  1. const struct netdev_class netdev_internal_class =
  2.     NETDEV_LINUX_CLASS(
  3.         "internal",
  4.         netdev_linux_construct,
  5.         netdev_internal_get_stats,
  6.         NULL, /* get_features */
  7.         netdev_internal_get_status);

 

其中NETDEV_LINUX_CLASS是一个宏，不是所有的参数都需要全部填写。

  1. #define NETDEV_LINUX_CLASS(NAME, CONSTRUCT, GET_STATS, \
  2.                            GET_FEATURES, GET_STATUS) \
  3. { \
  4.     NAME, \
  5.                                                                 \
  6.     NULL, \
  7.     netdev_linux_run, \
  8.     netdev_linux_wait, \
  9.                                                                 \
  10.     netdev_linux_alloc, \
  11.     CONSTRUCT, \
  12.     netdev_linux_destruct, \
  13.     netdev_linux_dealloc, \
  14.     NULL, /* get_config */ \
  15.     NULL, /* set_config */ \
  16.     NULL, /* get_tunnel_config */ \
  17.     NULL, /* build header */ \
  18.     NULL, /* push header */ \
  19.     NULL, /* pop header */ \
  20.     NULL, /* get_numa_id */ \
  21.     NULL, /* set_multiq */ \
  22.                                                                 \
  23.     netdev_linux_send, \
  24.     netdev_linux_send_wait, \
  25.                                                                 \
  26.     netdev_linux_set_etheraddr, \
  27.     netdev_linux_get_etheraddr, \
  28.     netdev_linux_get_mtu, \
  29.     netdev_linux_set_mtu, \
  30.     netdev_linux_get_ifindex, \
  31.     netdev_linux_get_carrier, \
  32.     netdev_linux_get_carrier_resets, \
  33.     netdev_linux_set_miimon_interval, \
  34.     GET_STATS, \
  35.                                                                 \
  36.     GET_FEATURES, \
  37.     netdev_linux_set_advertisements, \
  38.                                                                 \
  39.     netdev_linux_set_policing, \
  40.     netdev_linux_get_qos_types, \
  41.     netdev_linux_get_qos_capabilities, \
  42.     netdev_linux_get_qos, \
  43.     netdev_linux_set_qos, \
  44.     netdev_linux_get_queue, \
  45.     netdev_linux_set_queue, \
  46.     netdev_linux_delete_queue, \
  47.     netdev_linux_get_queue_stats, \
  48.     netdev_linux_queue_dump_start, \
  49.     netdev_linux_queue_dump_next, \
  50.     netdev_linux_queue_dump_done, \
  51.     netdev_linux_dump_queue_stats, \
  52.                                                                 \
  53.     netdev_linux_get_in4, \
  54.     netdev_linux_set_in4, \
  55.     netdev_linux_get_in6, \
  56.     netdev_linux_add_router, \
  57.     netdev_linux_get_next_hop, \
  58.     GET_STATUS, \
  59.     netdev_linux_arp_lookup, \
  60.                                                                 \
  61.     netdev_linux_update_flags, \
  62.                                                                 \
  63.     netdev_linux_rxq_alloc, \
  64.     netdev_linux_rxq_construct, \
  65.     netdev_linux_rxq_destruct, \
  66.     netdev_linux_rxq_dealloc, \
  67.     netdev_linux_rxq_recv, \
  68.     netdev_linux_rxq_wait, \
  69.     netdev_linux_rxq_drain, \
  70. }

 

rc->class->run()调用的是netdev-linux.c下的netdev_linux_run

 

netdev_linux_run会调用netlink的sock得到虚拟网卡的状态，并且更新状态。

 

  1. error = nl_sock_recv(sock, &buf, false);
  2. if (!error) {
  3.     struct rtnetlink_change change;
  4.     if (rtnetlink_parse(&buf, &change)) {
  5.         struct netdev *netdev_ = netdev_from_name(change.ifname);
  6.         if (netdev_ && is_netdev_linux_class(netdev_->netdev_class)) {
  7.            struct netdev_linux *netdev = netdev_linux_cast(netdev_);
  8.            ovs_mutex_lock(&netdev->mutex);
  9.            netdev_linux_update(netdev, &change);
  10.            ovs_mutex_unlock(&netdev->mutex);
  11.         }
  12.         netdev_close(netdev_);
  13.      }
  14. }

Openvswitch原理与代码分析(2): ovs-vswitchd的启动

标签：current   pid   代码   conf   pes   https   ESS   ISE   dealloc   

原文地址：https://www.cnblogs.com/dhcn/p/12793037.html
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