text: /* Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
   *
   * 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 <config.h>
  #include "bridge.h"
  #include <assert.h>
  #include <errno.h>
  #include <inttypes.h>
  #include <stdlib.h>
  #include "bitmap.h"
  #include "bond.h"
  #include "cfm.h"
  #include "coverage.h"
  #include "daemon.h"
  #include "dirs.h"
  #include "dynamic-string.h"
  #include "hash.h"
  #include "hmap.h"
  #include "hmapx.h"
  #include "jsonrpc.h"
  #include "lacp.h"
  #include "list.h"
  #include "mac-learning.h"
  #include "meta-flow.h"
  #include "netdev.h"
  #include "ofp-print.h"
  #include "ofpbuf.h"
  #include "ofproto/ofproto.h"
  #include "poll-loop.h"
  #include "sha1.h"
  #include "shash.h"
  #include "smap.h"
  #include "socket-util.h"
  #include "stream.h"
  #include "stream-ssl.h"
  #include "sset.h"
  #include "system-stats.h"
  #include "timeval.h"
  #include "util.h"
  #include "unixctl.h"
  #include "vlandev.h"
  #include "lib/vswitch-idl.h"
  #include "xenserver.h"
  #include "vlog.h"
  #include "sflow_api.h"
  #include "vlan-bitmap.h"
  
  VLOG_DEFINE_THIS_MODULE(bridge);
  
  COVERAGE_DEFINE(bridge_reconfigure);
  
  /* Configuration of an uninstantiated iface. */
  struct if_cfg {
      struct hmap_node hmap_node;         /* Node in bridge's if_cfg_todo. */
      const struct ovsrec_interface *cfg; /* Interface record. */
      const struct ovsrec_port *parent;   /* Parent port record. */
  };
  
  /* OpenFlow port slated for removal from ofproto. */
  struct ofpp_garbage {
      struct list list_node;      /* Node in bridge's ofpp_garbage. */
      uint16_t ofp_port;          /* Port to be deleted. */
  };
  
  struct iface {
      /* These members are always valid. */
      struct list port_elem;      /* Element in struct port's "ifaces" list. */
      struct hmap_node name_node; /* In struct bridge's "iface_by_name" hmap. */
      struct port *port;          /* Containing port. */
      char *name;                 /* Host network device name. */
  
      /* These members are valid only after bridge_reconfigure() causes them to
       * be initialized. */
      struct hmap_node ofp_port_node; /* In struct bridge's "ifaces" hmap. */
      int ofp_port;               /* OpenFlow port number, -1 if unknown. */
      struct netdev *netdev;      /* Network device. */
      const char *type;           /* Usually same as cfg->type. */
      const struct ovsrec_interface *cfg;
  };
  
  struct mirror {
      struct uuid uuid;           /* UUID of this "mirror" record in database. */
      struct hmap_node hmap_node; /* In struct bridge's "mirrors" hmap. */
      struct bridge *bridge;
      char *name;
      const struct ovsrec_mirror *cfg;
  };
  
  struct port {
      struct hmap_node hmap_node; /* Element in struct bridge's "ports" hmap. */
      struct bridge *bridge;
      char *name;
  
      const struct ovsrec_port *cfg;
  
      /* An ordinary bridge port has 1 interface.
       * A bridge port for bonding has at least 2 interfaces. */
      struct list ifaces;         /* List of "struct iface"s. */
  };
  
  struct bridge {
      struct hmap_node node;      /* In 'all_bridges'. */
      char *name;                 /* User-specified arbitrary name. */
      char *type;                 /* Datapath type. */
      uint8_t ea[ETH_ADDR_LEN];   /* Bridge Ethernet Address. */
      uint8_t default_ea[ETH_ADDR_LEN]; /* Default MAC. */
      const struct ovsrec_bridge *cfg;
  
      /* OpenFlow switch processing. */
      struct ofproto *ofproto;    /* OpenFlow switch. */
  
      /* Bridge ports. */
      struct hmap ports;          /* "struct port"s indexed by name. */
      struct hmap ifaces;         /* "struct iface"s indexed by ofp_port. */
      struct hmap iface_by_name;  /* "struct iface"s indexed by name. */
  
      struct list ofpp_garbage;   /* "struct ofpp_garbage" slated for removal. */
      struct hmap if_cfg_todo;    /* "struct if_cfg"s slated for creation.
                                     Indexed on 'cfg->name'. */
  
      /* Port mirroring. */
      struct hmap mirrors;        /* "struct mirror" indexed by UUID. */
  
      /* Synthetic local port if necessary. */
      struct ovsrec_port synth_local_port;
      struct ovsrec_interface synth_local_iface;
      struct ovsrec_interface *synth_local_ifacep;
  };
  
  /* All bridges, indexed by name. */
  static struct hmap all_bridges = HMAP_INITIALIZER(&all_bridges);
  
  /* OVSDB IDL used to obtain configuration. */
  static struct ovsdb_idl *idl;
  
  /* Most recently processed IDL sequence number. */
  static unsigned int idl_seqno;
  
  /* Each time this timer expires, the bridge fetches interface and mirror
   * statistics and pushes them into the database. */
  #define IFACE_STATS_INTERVAL (5 * 1000) /* In milliseconds. */
  static long long int iface_stats_timer = LLONG_MIN;
  
  /* In some datapaths, creating and destroying OpenFlow ports can be extremely
   * expensive.  This can cause bridge_reconfigure() to take a long time during
   * which no other work can be done.  To deal with this problem, we limit port
   * adds and deletions to a window of OFP_PORT_ACTION_WINDOW milliseconds per
   * call to bridge_reconfigure().  If there is more work to do after the limit
   * is reached, 'need_reconfigure', is flagged and it's done on the next loop.
   * This allows the rest of the code to catch up on important things like
   * forwarding packets. */
  #define OFP_PORT_ACTION_WINDOW 10
  static bool reconfiguring = false;
  
  static void add_del_bridges(const struct ovsrec_open_vswitch *);
  static void bridge_update_ofprotos(void);
  static void bridge_create(const struct ovsrec_bridge *);
  static void bridge_destroy(struct bridge *);
  static struct bridge *bridge_lookup(const char *name);
  static unixctl_cb_func bridge_unixctl_dump_flows;
  static unixctl_cb_func bridge_unixctl_reconnect;
  static size_t bridge_get_controllers(const struct bridge *br,
                                       struct ovsrec_controller ***controllersp);
  static void bridge_add_del_ports(struct bridge *,
                                   const unsigned long int *splinter_vlans);
  static void bridge_refresh_ofp_port(struct bridge *);
  static void bridge_configure_datapath_id(struct bridge *);
  static void bridge_configure_flow_eviction_threshold(struct bridge *);
  static void bridge_configure_netflow(struct bridge *);
  static void bridge_configure_forward_bpdu(struct bridge *);
  static void bridge_configure_mac_idle_time(struct bridge *);
  static void bridge_configure_sflow(struct bridge *, int *sflow_bridge_number);
  static void bridge_configure_stp(struct bridge *);
  static void bridge_configure_tables(struct bridge *);
  static void bridge_configure_remotes(struct bridge *,
                                       const struct sockaddr_in *managers,
                                       size_t n_managers);
  static void bridge_pick_local_hw_addr(struct bridge *,
                                        uint8_t ea[ETH_ADDR_LEN],
                                        struct iface **hw_addr_iface);
  static uint64_t bridge_pick_datapath_id(struct bridge *,
                                          const uint8_t bridge_ea[ETH_ADDR_LEN],
                                          struct iface *hw_addr_iface);
  static void bridge_queue_if_cfg(struct bridge *,
                                  const struct ovsrec_interface *,
                                  const struct ovsrec_port *);
  static uint64_t dpid_from_hash(const void *, size_t nbytes);
  static bool bridge_has_bond_fake_iface(const struct bridge *,
                                         const char *name);
  static bool port_is_bond_fake_iface(const struct port *);
  
  static unixctl_cb_func qos_unixctl_show;
  
  static struct port *port_create(struct bridge *, const struct ovsrec_port *);
  static void port_del_ifaces(struct port *);
  static void port_destroy(struct port *);
  static struct port *port_lookup(const struct bridge *, const char *name);
  static void port_configure(struct port *);
  static struct lacp_settings *port_configure_lacp(struct port *,
                                                   struct lacp_settings *);
  static void port_configure_bond(struct port *, struct bond_settings *,
                                  uint32_t *bond_stable_ids);
  static bool port_is_synthetic(const struct port *);
  
  static void reconfigure_system_stats(const struct ovsrec_open_vswitch *);
  static void run_system_stats(void);
  
  static void bridge_configure_mirrors(struct bridge *);
  static struct mirror *mirror_create(struct bridge *,
                                      const struct ovsrec_mirror *);
  static void mirror_destroy(struct mirror *);
  static bool mirror_configure(struct mirror *);
  static void mirror_refresh_stats(struct mirror *);
  
  static void iface_configure_lacp(struct iface *, struct lacp_slave_settings *);
  static bool iface_create(struct bridge *, struct if_cfg *, int ofp_port);
  static const char *iface_get_type(const struct ovsrec_interface *,
                                    const struct ovsrec_bridge *);
  static void iface_destroy(struct iface *);
  static struct iface *iface_lookup(const struct bridge *, const char *name);
  static struct iface *iface_find(const char *name);
  static struct if_cfg *if_cfg_lookup(const struct bridge *, const char *name);
  static struct iface *iface_from_ofp_port(const struct bridge *,
                                           uint16_t ofp_port);
  static void iface_set_mac(struct iface *);
  static void iface_set_ofport(const struct ovsrec_interface *, int64_t ofport);
  static void iface_clear_db_record(const struct ovsrec_interface *if_cfg);
  static void iface_configure_qos(struct iface *, const struct ovsrec_qos *);
  static void iface_configure_cfm(struct iface *);
  static void iface_refresh_cfm_stats(struct iface *);
  static void iface_refresh_stats(struct iface *);
  static void iface_refresh_status(struct iface *);
  static bool iface_is_synthetic(const struct iface *);
  
  /* Linux VLAN device support (e.g. "eth0.10" for VLAN 10.)
   *
   * This is deprecated.  It is only for compatibility with broken device drivers
   * in old versions of Linux that do not properly support VLANs when VLAN
   * devices are not used.  When broken device drivers are no longer in
   * widespread use, we will delete these interfaces. */
  
  /* True if VLAN splinters are enabled on any interface, false otherwise.*/
  static bool vlan_splinters_enabled_anywhere;
  
  static bool vlan_splinters_is_enabled(const struct ovsrec_interface *);
  static unsigned long int *collect_splinter_vlans(
      const struct ovsrec_open_vswitch *);
  static void configure_splinter_port(struct port *);
  static void add_vlan_splinter_ports(struct bridge *,
                                      const unsigned long int *splinter_vlans,
                                      struct shash *ports);
  
  /* Public functions. */
  
  /* Initializes the bridge module, configuring it to obtain its configuration
   * from an OVSDB server accessed over 'remote', which should be a string in a
   * form acceptable to ovsdb_idl_create(). */
  void
  bridge_init(const char *remote)
  {
      /* Create connection to database. */
      idl = ovsdb_idl_create(remote, &ovsrec_idl_class, true);
      idl_seqno = ovsdb_idl_get_seqno(idl);
      ovsdb_idl_set_lock(idl, "ovs_vswitchd");
      ovsdb_idl_verify_write_only(idl);
  
      ovsdb_idl_omit_alert(idl, &ovsrec_open_vswitch_col_cur_cfg);
      ovsdb_idl_omit_alert(idl, &ovsrec_open_vswitch_col_statistics);
      ovsdb_idl_omit(idl, &ovsrec_open_vswitch_col_external_ids);
      ovsdb_idl_omit(idl, &ovsrec_open_vswitch_col_ovs_version);
      ovsdb_idl_omit(idl, &ovsrec_open_vswitch_col_db_version);
      ovsdb_idl_omit(idl, &ovsrec_open_vswitch_col_system_type);
      ovsdb_idl_omit(idl, &ovsrec_open_vswitch_col_system_version);
  
      ovsdb_idl_omit_alert(idl, &ovsrec_bridge_col_datapath_id);
      ovsdb_idl_omit_alert(idl, &ovsrec_bridge_col_status);
      ovsdb_idl_omit(idl, &ovsrec_bridge_col_external_ids);
  
      ovsdb_idl_omit_alert(idl, &ovsrec_port_col_status);
      ovsdb_idl_omit_alert(idl, &ovsrec_port_col_statistics);
      ovsdb_idl_omit(idl, &ovsrec_port_col_external_ids);
      ovsdb_idl_omit(idl, &ovsrec_port_col_fake_bridge);
  
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_admin_state);
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_duplex);
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_link_speed);
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_link_state);
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_link_resets);
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_mtu);
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_ofport);
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_statistics);
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_status);
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_cfm_fault);
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_cfm_fault_status);
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_cfm_remote_mpids);
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_cfm_health);
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_cfm_remote_opstate);
      ovsdb_idl_omit_alert(idl, &ovsrec_interface_col_lacp_current);
      ovsdb_idl_omit(idl, &ovsrec_interface_col_external_ids);
  
      ovsdb_idl_omit_alert(idl, &ovsrec_controller_col_is_connected);
      ovsdb_idl_omit_alert(idl, &ovsrec_controller_col_role);
      ovsdb_idl_omit_alert(idl, &ovsrec_controller_col_status);
      ovsdb_idl_omit(idl, &ovsrec_controller_col_external_ids);
  
      ovsdb_idl_omit(idl, &ovsrec_qos_col_external_ids);
  
      ovsdb_idl_omit(idl, &ovsrec_queue_col_external_ids);
  
      ovsdb_idl_omit(idl, &ovsrec_mirror_col_external_ids);
      ovsdb_idl_omit_alert(idl, &ovsrec_mirror_col_statistics);
  
      ovsdb_idl_omit(idl, &ovsrec_netflow_col_external_ids);
  
      ovsdb_idl_omit(idl, &ovsrec_sflow_col_external_ids);
  
      ovsdb_idl_omit(idl, &ovsrec_manager_col_external_ids);
      ovsdb_idl_omit(idl, &ovsrec_manager_col_inactivity_probe);
      ovsdb_idl_omit(idl, &ovsrec_manager_col_is_connected);
      ovsdb_idl_omit(idl, &ovsrec_manager_col_max_backoff);
      ovsdb_idl_omit(idl, &ovsrec_manager_col_status);
  
      ovsdb_idl_omit(idl, &ovsrec_ssl_col_external_ids);
  
      /* Register unixctl commands. */
      unixctl_command_register("qos/show", "interface", 1, 1,
                               qos_unixctl_show, NULL);
      unixctl_command_register("bridge/dump-flows", "bridge", 1, 1,
                               bridge_unixctl_dump_flows, NULL);
      unixctl_command_register("bridge/reconnect", "[bridge]", 0, 1,
                               bridge_unixctl_reconnect, NULL);
      lacp_init();
      bond_init();
      cfm_init();
      stp_init();
  }
  
  void
  bridge_exit(void)
  {
      struct bridge *br, *next_br;
  
      HMAP_FOR_EACH_SAFE (br, next_br, node, &all_bridges) {
          bridge_destroy(br);
      }
      ovsdb_idl_destroy(idl);
  }
  
  /* Looks at the list of managers in 'ovs_cfg' and extracts their remote IP
   * addresses and ports into '*managersp' and '*n_managersp'.  The caller is
   * responsible for freeing '*managersp' (with free()).
   *
   * You may be asking yourself "why does ovs-vswitchd care?", because
   * ovsdb-server is responsible for connecting to the managers, and ovs-vswitchd
   * should not be and in fact is not directly involved in that.  But
   * ovs-vswitchd needs to make sure that ovsdb-server can reach the managers, so
   * it has to tell in-band control where the managers are to enable that.
   * (Thus, only managers connected in-band are collected.)
   */
  static void
  collect_in_band_managers(const struct ovsrec_open_vswitch *ovs_cfg,
                           struct sockaddr_in **managersp, size_t *n_managersp)
  {
      struct sockaddr_in *managers = NULL;
      size_t n_managers = 0;
      struct sset targets;
      size_t i;
  
      /* Collect all of the potential targets from the "targets" columns of the
       * rows pointed to by "manager_options", excluding any that are
       * out-of-band. */
      sset_init(&targets);
      for (i = 0; i < ovs_cfg->n_manager_options; i++) {
          struct ovsrec_manager *m = ovs_cfg->manager_options[i];
  
          if (m->connection_mode && !strcmp(m->connection_mode, "out-of-band")) {
              sset_find_and_delete(&targets, m->target);
          } else {
              sset_add(&targets, m->target);
          }
      }
  
      /* Now extract the targets' IP addresses. */
      if (!sset_is_empty(&targets)) {
          const char *target;
  
          managers = xmalloc(sset_count(&targets) * sizeof *managers);
          SSET_FOR_EACH (target, &targets) {
              struct sockaddr_in *sin = &managers[n_managers];
  
              if (stream_parse_target_with_default_ports(target,
                                                         JSONRPC_TCP_PORT,
                                                         JSONRPC_SSL_PORT,
                                                         sin)) {
                  n_managers++;
              }
          }
      }
      sset_destroy(&targets);
  
      *managersp = managers;
      *n_managersp = n_managers;
  }
  
  static void
  bridge_reconfigure(const struct ovsrec_open_vswitch *ovs_cfg)
  {
      unsigned long int *splinter_vlans;
      struct bridge *br;
  
      COVERAGE_INC(bridge_reconfigure);
  
      assert(!reconfiguring);
      reconfiguring = true;
  
      /* Destroy "struct bridge"s, "struct port"s, and "struct iface"s according
       * to 'ovs_cfg' while update the "if_cfg_queue", with only very minimal
       * configuration otherwise.
       *
       * This is mostly an update to bridge data structures. Nothing is pushed
       * down to ofproto or lower layers. */
      add_del_bridges(ovs_cfg);
      splinter_vlans = collect_splinter_vlans(ovs_cfg);
      HMAP_FOR_EACH (br, node, &all_bridges) {
          bridge_add_del_ports(br, splinter_vlans);
      }
      free(splinter_vlans);
  
      /* Delete datapaths that are no longer configured, and create ones which
       * don't exist but should. */
      bridge_update_ofprotos();
  
      /* Make sure each "struct iface" has a correct ofp_port in its ofproto. */
      HMAP_FOR_EACH (br, node, &all_bridges) {
          bridge_refresh_ofp_port(br);
      }
  
      /* Clear database records for "if_cfg"s which haven't been instantiated. */
      HMAP_FOR_EACH (br, node, &all_bridges) {
          struct if_cfg *if_cfg;
  
          HMAP_FOR_EACH (if_cfg, hmap_node, &br->if_cfg_todo) {
              iface_clear_db_record(if_cfg->cfg);
          }
      }
  
      reconfigure_system_stats(ovs_cfg);
  }
  
  static bool
  bridge_reconfigure_ofp(void)
  {
      long long int deadline;
      struct bridge *br;
  
      time_refresh();
      deadline = time_msec() + OFP_PORT_ACTION_WINDOW;
  
      /* The kernel will reject any attempt to add a given port to a datapath if
       * that port already belongs to a different datapath, so we must do all
       * port deletions before any port additions. */
      HMAP_FOR_EACH (br, node, &all_bridges) {
          struct ofpp_garbage *garbage, *next;
  
          LIST_FOR_EACH_SAFE (garbage, next, list_node, &br->ofpp_garbage) {
              /* It's a bit dangerous to call bridge_run_fast() here as ofproto's
               * internal datastructures may not be consistent.  Eventually, when
               * port additions and deletions are cheaper, these calls should be
               * removed. */
              bridge_run_fast();
              ofproto_port_del(br->ofproto, garbage->ofp_port);
              list_remove(&garbage->list_node);
              free(garbage);
  
              time_refresh();
              if (time_msec() >= deadline) {
                  return false;
              }
              bridge_run_fast();
          }
      }
  
      HMAP_FOR_EACH (br, node, &all_bridges) {
          struct if_cfg *if_cfg, *next;
  
          HMAP_FOR_EACH_SAFE (if_cfg, next, hmap_node, &br->if_cfg_todo) {
              iface_create(br, if_cfg, -1);
              time_refresh();
              if (time_msec() >= deadline) {
                  return false;
              }
          }
      }
  
      return true;
  }
  
  static bool
  bridge_reconfigure_continue(const struct ovsrec_open_vswitch *ovs_cfg)
  {
      struct sockaddr_in *managers;
      int sflow_bridge_number;
      size_t n_managers;
      struct bridge *br;
      bool done;
  
      assert(reconfiguring);
      done = bridge_reconfigure_ofp();
  
      /* Complete the configuration. */
      sflow_bridge_number = 0;
      collect_in_band_managers(ovs_cfg, &managers, &n_managers);
      HMAP_FOR_EACH (br, node, &all_bridges) {
          struct port *port;
  
          /* We need the datapath ID early to allow LACP ports to use it as the
           * default system ID. */
          bridge_configure_datapath_id(br);
  
          HMAP_FOR_EACH (port, hmap_node, &br->ports) {
              struct iface *iface;
  
              port_configure(port);
  
              LIST_FOR_EACH (iface, port_elem, &port->ifaces) {
                  iface_configure_cfm(iface);
                  iface_configure_qos(iface, port->cfg->qos);
                  iface_set_mac(iface);
              }
          }
          bridge_configure_mirrors(br);
          bridge_configure_flow_eviction_threshold(br);
          bridge_configure_forward_bpdu(br);
          bridge_configure_mac_idle_time(br);
          bridge_configure_remotes(br, managers, n_managers);
          bridge_configure_netflow(br);
          bridge_configure_sflow(br, &sflow_bridge_number);
          bridge_configure_stp(br);
          bridge_configure_tables(br);
      }
      free(managers);
  
      if (done) {
          /* ovs-vswitchd has completed initialization, so allow the process that
           * forked us to exit successfully. */
          daemonize_complete();
          reconfiguring = false;
  
          VLOG_INFO("%s (Open vSwitch) %s", program_name, VERSION);
      }
  
      return done;
  }
  
  /* Delete ofprotos which aren't configured or have the wrong type.  Create
   * ofprotos which don't exist but need to. */
  static void
  bridge_update_ofprotos(void)
  {
      struct bridge *br, *next;
      struct sset names;
      struct sset types;
      const char *type;
  
      /* Delete ofprotos with no bridge or with the wrong type. */
      sset_init(&names);
      sset_init(&types);
      ofproto_enumerate_types(&types);
      SSET_FOR_EACH (type, &types) {
          const char *name;
  
          ofproto_enumerate_names(type, &names);
          SSET_FOR_EACH (name, &names) {
              br = bridge_lookup(name);
              if (!br || strcmp(type, br->type)) {
                  ofproto_delete(name, type);
              }
          }
      }
      sset_destroy(&names);
      sset_destroy(&types);
  
      /* Add ofprotos for bridges which don't have one yet. */
      HMAP_FOR_EACH_SAFE (br, next, node, &all_bridges) {
          struct bridge *br2;
          int error;
  
          if (br->ofproto) {
              continue;
          }
  
          /* Remove ports from any datapath with the same name as 'br'.  If we
           * don't do this, creating 'br''s ofproto will fail because a port with
           * the same name as its local port already exists. */
          HMAP_FOR_EACH (br2, node, &all_bridges) {
              struct ofproto_port ofproto_port;
  
              if (!br2->ofproto) {
                  continue;
              }
  
              if (!ofproto_port_query_by_name(br2->ofproto, br->name,
                                              &ofproto_port)) {
                  error = ofproto_port_del(br2->ofproto, ofproto_port.ofp_port);
                  if (error) {
                      VLOG_ERR("failed to delete port %s: %s", ofproto_port.name,
                               strerror(error));
                  }
                  ofproto_port_destroy(&ofproto_port);
              }
          }
  
          error = ofproto_create(br->name, br->type, &br->ofproto);
          if (error) {
              VLOG_ERR("failed to create bridge %s: %s", br->name,
                       strerror(error));
              bridge_destroy(br);
          }
      }
  }
  
  static void
  port_configure(struct port *port)
  {
      const struct ovsrec_port *cfg = port->cfg;
      struct bond_settings bond_settings;
      struct lacp_settings lacp_settings;
      struct ofproto_bundle_settings s;
      struct iface *iface;
  
      if (cfg->vlan_mode && !strcmp(cfg->vlan_mode, "splinter")) {
          configure_splinter_port(port);
          return;
      }
  
      /* Get name. */
      s.name = port->name;
  
      /* Get slaves. */
      s.n_slaves = 0;
      s.slaves = xmalloc(list_size(&port->ifaces) * sizeof *s.slaves);
      LIST_FOR_EACH (iface, port_elem, &port->ifaces) {
          s.slaves[s.n_slaves++] = iface->ofp_port;
      }
  
      /* Get VLAN tag. */
      s.vlan = -1;
      if (cfg->tag && *cfg->tag >= 0 && *cfg->tag <= 4095) {
          s.vlan = *cfg->tag;
      }
  
      /* Get VLAN trunks. */
      s.trunks = NULL;
      if (cfg->n_trunks) {
          s.trunks = vlan_bitmap_from_array(cfg->trunks, cfg->n_trunks);
      }
  
      /* Get VLAN mode. */
      if (cfg->vlan_mode) {
          if (!strcmp(cfg->vlan_mode, "access")) {
              s.vlan_mode = PORT_VLAN_ACCESS;
          } else if (!strcmp(cfg->vlan_mode, "trunk")) {
              s.vlan_mode = PORT_VLAN_TRUNK;
          } else if (!strcmp(cfg->vlan_mode, "native-tagged")) {
              s.vlan_mode = PORT_VLAN_NATIVE_TAGGED;
          } else if (!strcmp(cfg->vlan_mode, "native-untagged")) {
              s.vlan_mode = PORT_VLAN_NATIVE_UNTAGGED;
          } else {
              /* This "can't happen" because ovsdb-server should prevent it. */
              VLOG_ERR("unknown VLAN mode %s", cfg->vlan_mode);
              s.vlan_mode = PORT_VLAN_TRUNK;
          }
      } else {
          if (s.vlan >= 0) {
              s.vlan_mode = PORT_VLAN_ACCESS;
              if (cfg->n_trunks) {
                  VLOG_ERR("port %s: ignoring trunks in favor of implicit vlan",
                           port->name);
              }
          } else {
              s.vlan_mode = PORT_VLAN_TRUNK;
          }
      }
      s.use_priority_tags = smap_get_bool(&cfg->other_config, "priority-tags",
                                          false);
  
      /* Get LACP settings. */
      s.lacp = port_configure_lacp(port, &lacp_settings);
      if (s.lacp) {
          size_t i = 0;
  
          s.lacp_slaves = xmalloc(s.n_slaves * sizeof *s.lacp_slaves);
          LIST_FOR_EACH (iface, port_elem, &port->ifaces) {
              iface_configure_lacp(iface, &s.lacp_slaves[i++]);
          }
      } else {
          s.lacp_slaves = NULL;
      }
  
      /* Get bond settings. */
      if (s.n_slaves > 1) {
          s.bond = &bond_settings;
          s.bond_stable_ids = xmalloc(s.n_slaves * sizeof *s.bond_stable_ids);
          port_configure_bond(port, &bond_settings, s.bond_stable_ids);
      } else {
          s.bond = NULL;
          s.bond_stable_ids = NULL;
  
          LIST_FOR_EACH (iface, port_elem, &port->ifaces) {
              netdev_set_miimon_interval(iface->netdev, 0);
          }
      }
  
      /* Register. */
      ofproto_bundle_register(port->bridge->ofproto, port, &s);
  
      /* Clean up. */
      free(s.slaves);
      free(s.trunks);
      free(s.lacp_slaves);
      free(s.bond_stable_ids);
  }
  
  /* Pick local port hardware address and datapath ID for 'br'. */
  static void
  bridge_configure_datapath_id(struct bridge *br)
  {
      uint8_t ea[ETH_ADDR_LEN];
      uint64_t dpid;
      struct iface *local_iface;
      struct iface *hw_addr_iface;
      char *dpid_string;
  
      bridge_pick_local_hw_addr(br, ea, &hw_addr_iface);
      local_iface = iface_from_ofp_port(br, OFPP_LOCAL);
      if (local_iface) {
          int error = netdev_set_etheraddr(local_iface->netdev, ea);
          if (error) {
              static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
              VLOG_ERR_RL(&rl, "bridge %s: failed to set bridge "
                          "Ethernet address: %s",
                          br->name, strerror(error));
          }
      }
      memcpy(br->ea, ea, ETH_ADDR_LEN);
  
      dpid = bridge_pick_datapath_id(br, ea, hw_addr_iface);
      if (dpid != ofproto_get_datapath_id(br->ofproto)) {
          VLOG_INFO("bridge %s: using datapath ID %016"PRIx64, br->name, dpid);
          ofproto_set_datapath_id(br->ofproto, dpid);
      }
  
      dpid_string = xasprintf("%016"PRIx64, dpid);
      ovsrec_bridge_set_datapath_id(br->cfg, dpid_string);
      free(dpid_string);
  }
  
  /* Set NetFlow configuration on 'br'. */
  static void
  bridge_configure_netflow(struct bridge *br)
  {
      struct ovsrec_netflow *cfg = br->cfg->netflow;
      struct netflow_options opts;
  
      if (!cfg) {
          ofproto_set_netflow(br->ofproto, NULL);
          return;
      }
  
      memset(&opts, 0, sizeof opts);
  
      /* Get default NetFlow configuration from datapath.
       * Apply overrides from 'cfg'. */
      ofproto_get_netflow_ids(br->ofproto, &opts.engine_type, &opts.engine_id);
      if (cfg->engine_type) {
          opts.engine_type = *cfg->engine_type;
      }
      if (cfg->engine_id) {
          opts.engine_id = *cfg->engine_id;
      }
  
      /* Configure active timeout interval. */
      opts.active_timeout = cfg->active_timeout;
      if (!opts.active_timeout) {
          opts.active_timeout = -1;
      } else if (opts.active_timeout < 0) {
          VLOG_WARN("bridge %s: active timeout interval set to negative "
                    "value, using default instead (%d seconds)", br->name,
                    NF_ACTIVE_TIMEOUT_DEFAULT);
          opts.active_timeout = -1;
      }
  
      /* Add engine ID to interface number to disambiguate bridgs? */
      opts.add_id_to_iface = cfg->add_id_to_interface;
      if (opts.add_id_to_iface) {
          if (opts.engine_id > 0x7f) {
              VLOG_WARN("bridge %s: NetFlow port mangling may conflict with "
                        "another vswitch, choose an engine id less than 128",
                        br->name);
          }
          if (hmap_count(&br->ports) > 508) {
              VLOG_WARN("bridge %s: NetFlow port mangling will conflict with "
                        "another port when more than 508 ports are used",
                        br->name);
          }
      }
  
      /* Collectors. */
      sset_init(&opts.collectors);
      sset_add_array(&opts.collectors, cfg->targets, cfg->n_targets);
  
      /* Configure. */
      if (ofproto_set_netflow(br->ofproto, &opts)) {
          VLOG_ERR("bridge %s: problem setting netflow collectors", br->name);
      }
      sset_destroy(&opts.collectors);
  }
  
  /* Set sFlow configuration on 'br'. */
  static void
  bridge_configure_sflow(struct bridge *br, int *sflow_bridge_number)
  {
      const struct ovsrec_sflow *cfg = br->cfg->sflow;
      struct ovsrec_controller **controllers;
      struct ofproto_sflow_options oso;
      size_t n_controllers;
      size_t i;
  
      if (!cfg) {
          ofproto_set_sflow(br->ofproto, NULL);
          return;
      }
  
      memset(&oso, 0, sizeof oso);
  
      sset_init(&oso.targets);
      sset_add_array(&oso.targets, cfg->targets, cfg->n_targets);
  
      oso.sampling_rate = SFL_DEFAULT_SAMPLING_RATE;
      if (cfg->sampling) {
          oso.sampling_rate = *cfg->sampling;
      }
  
      oso.polling_interval = SFL_DEFAULT_POLLING_INTERVAL;
      if (cfg->polling) {
          oso.polling_interval = *cfg->polling;
      }
  
      oso.header_len = SFL_DEFAULT_HEADER_SIZE;
      if (cfg->header) {
          oso.header_len = *cfg->header;
      }
  
      oso.sub_id = (*sflow_bridge_number)++;
      oso.agent_device = cfg->agent;
  
      oso.control_ip = NULL;
      n_controllers = bridge_get_controllers(br, &controllers);
      for (i = 0; i < n_controllers; i++) {
          if (controllers[i]->local_ip) {
              oso.control_ip = controllers[i]->local_ip;
              break;
          }
      }
      ofproto_set_sflow(br->ofproto, &oso);
  
      sset_destroy(&oso.targets);
  }
  
  static void
  port_configure_stp(const struct ofproto *ofproto, struct port *port,
                     struct ofproto_port_stp_settings *port_s,
                     int *port_num_counter, unsigned long *port_num_bitmap)
  {
      const char *config_str;
      struct iface *iface;
  
      if (!smap_get_bool(&port->cfg->other_config, "stp-enable", true)) {
          port_s->enable = false;
          return;
      } else {
          port_s->enable = true;
      }
  
      /* STP over bonds is not supported. */
      if (!list_is_singleton(&port->ifaces)) {
          VLOG_ERR("port %s: cannot enable STP on bonds, disabling",
                   port->name);
          port_s->enable = false;
          return;
      }
  
      iface = CONTAINER_OF(list_front(&port->ifaces), struct iface, port_elem);
  
      /* Internal ports shouldn't participate in spanning tree, so
       * skip them. */
      if (!strcmp(iface->type, "internal")) {
          VLOG_DBG("port %s: disable STP on internal ports", port->name);
          port_s->enable = false;
          return;
      }
  
      /* STP on mirror output ports is not supported. */
      if (ofproto_is_mirror_output_bundle(ofproto, port)) {
          VLOG_DBG("port %s: disable STP on mirror ports", port->name);
          port_s->enable = false;
          return;
      }
  
      config_str = smap_get(&port->cfg->other_config, "stp-port-num");
      if (config_str) {
          unsigned long int port_num = strtoul(config_str, NULL, 0);
          int port_idx = port_num - 1;
  
          if (port_num < 1 || port_num > STP_MAX_PORTS) {
              VLOG_ERR("port %s: invalid stp-port-num", port->name);
              port_s->enable = false;
              return;
          }
  
          if (bitmap_is_set(port_num_bitmap, port_idx)) {
              VLOG_ERR("port %s: duplicate stp-port-num %lu, disabling",
                      port->name, port_num);
              port_s->enable = false;
              return;
          }
          bitmap_set1(port_num_bitmap, port_idx);
          port_s->port_num = port_idx;
      } else {
          if (*port_num_counter >= STP_MAX_PORTS) {
              VLOG_ERR("port %s: too many STP ports, disabling", port->name);
              port_s->enable = false;
              return;
          }
  
          port_s->port_num = (*port_num_counter)++;
      }
  
      config_str = smap_get(&port->cfg->other_config, "stp-path-cost");
      if (config_str) {
          port_s->path_cost = strtoul(config_str, NULL, 10);
      } else {
          enum netdev_features current;
  
          if (netdev_get_features(iface->netdev, &current, NULL, NULL, NULL)) {
              /* Couldn't get speed, so assume 100Mb/s. */
              port_s->path_cost = 19;
          } else {
              unsigned int mbps;
  
              mbps = netdev_features_to_bps(current) / 1000000;
              port_s->path_cost = stp_convert_speed_to_cost(mbps);
          }
      }
  
      config_str = smap_get(&port->cfg->other_config, "stp-port-priority");
      if (config_str) {
          port_s->priority = strtoul(config_str, NULL, 0);
      } else {
          port_s->priority = STP_DEFAULT_PORT_PRIORITY;
      }
  }
  
  /* Set spanning tree configuration on 'br'. */
  static void
  bridge_configure_stp(struct bridge *br)
  {
      if (!br->cfg->stp_enable) {
          ofproto_set_stp(br->ofproto, NULL);
      } else {
          struct ofproto_stp_settings br_s;
          const char *config_str;
          struct port *port;
          int port_num_counter;
          unsigned long *port_num_bitmap;
  
          config_str = smap_get(&br->cfg->other_config, "stp-system-id");
          if (config_str) {
              uint8_t ea[ETH_ADDR_LEN];
  
              if (eth_addr_from_string(config_str, ea)) {
                  br_s.system_id = eth_addr_to_uint64(ea);
              } else {
                  br_s.system_id = eth_addr_to_uint64(br->ea);
                  VLOG_ERR("bridge %s: invalid stp-system-id, defaulting "
                           "to "ETH_ADDR_FMT, br->name, ETH_ADDR_ARGS(br->ea));
              }
          } else {
              br_s.system_id = eth_addr_to_uint64(br->ea);
          }
  
          config_str = smap_get(&br->cfg->other_config, "stp-priority");
          if (config_str) {
              br_s.priority = strtoul(config_str, NULL, 0);
          } else {
              br_s.priority = STP_DEFAULT_BRIDGE_PRIORITY;
          }
  
          config_str = smap_get(&br->cfg->other_config, "stp-hello-time");
          if (config_str) {
              br_s.hello_time = strtoul(config_str, NULL, 10) * 1000;
          } else {
              br_s.hello_time = STP_DEFAULT_HELLO_TIME;
          }
  
          config_str = smap_get(&br->cfg->other_config, "stp-max-age");
          if (config_str) {
              br_s.max_age = strtoul(config_str, NULL, 10) * 1000;
          } else {
              br_s.max_age = STP_DEFAULT_MAX_AGE;
          }
  
          config_str = smap_get(&br->cfg->other_config, "stp-forward-delay");
          if (config_str) {
              br_s.fwd_delay = strtoul(config_str, NULL, 10) * 1000;
          } else {
              br_s.fwd_delay = STP_DEFAULT_FWD_DELAY;
          }
  
          /* Configure STP on the bridge. */
          if (ofproto_set_stp(br->ofproto, &br_s)) {
              VLOG_ERR("bridge %s: could not enable STP", br->name);
              return;
          }
  
          /* Users must either set the port number with the "stp-port-num"
           * configuration on all ports or none.  If manual configuration
           * is not done, then we allocate them sequentially. */
          port_num_counter = 0;
          port_num_bitmap = bitmap_allocate(STP_MAX_PORTS);
          HMAP_FOR_EACH (port, hmap_node, &br->ports) {
              struct ofproto_port_stp_settings port_s;
              struct iface *iface;
  
              port_configure_stp(br->ofproto, port, &port_s,
                                 &port_num_counter, port_num_bitmap);
  
              /* As bonds are not supported, just apply configuration to
               * all interfaces. */
              LIST_FOR_EACH (iface, port_elem, &port->ifaces) {
                  if (ofproto_port_set_stp(br->ofproto, iface->ofp_port,
                                           &port_s)) {
                      VLOG_ERR("port %s: could not enable STP", port->name);
                      continue;
                  }
              }
          }
  
          if (bitmap_scan(port_num_bitmap, 0, STP_MAX_PORTS) != STP_MAX_PORTS
                      && port_num_counter) {
              VLOG_ERR("bridge %s: must manually configure all STP port "
                       "IDs or none, disabling", br->name);
              ofproto_set_stp(br->ofproto, NULL);
          }
          bitmap_free(port_num_bitmap);
      }
  }
  
  static bool
  bridge_has_bond_fake_iface(const struct bridge *br, const char *name)
  {
      const struct port *port = port_lookup(br, name);
      return port && port_is_bond_fake_iface(port);
  }
  
  static bool
  port_is_bond_fake_iface(const struct port *port)
  {
      return port->cfg->bond_fake_iface && !list_is_short(&port->ifaces);
  }
  
  static void
  add_del_bridges(const struct ovsrec_open_vswitch *cfg)
  {
      struct bridge *br, *next;
      struct shash new_br;
      size_t i;
  
      /* Collect new bridges' names and types. */
      shash_init(&new_br);
      for (i = 0; i < cfg->n_bridges; i++) {
          static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
          const struct ovsrec_bridge *br_cfg = cfg->bridges[i];
  
          if (strchr(br_cfg->name, '/')) {
              /* Prevent remote ovsdb-server users from accessing arbitrary
               * directories, e.g. consider a bridge named "../../../etc/". */
              VLOG_WARN_RL(&rl, "ignoring bridge with invalid name \"%s\"",
                           br_cfg->name);
          } else if (!shash_add_once(&new_br, br_cfg->name, br_cfg)) {
              VLOG_WARN_RL(&rl, "bridge %s specified twice", br_cfg->name);
          }
      }
  
      /* Get rid of deleted bridges or those whose types have changed.
       * Update 'cfg' of bridges that still exist. */
      HMAP_FOR_EACH_SAFE (br, next, node, &all_bridges) {
          br->cfg = shash_find_data(&new_br, br->name);
          if (!br->cfg || strcmp(br->type, ofproto_normalize_type(
                                     br->cfg->datapath_type))) {
              bridge_destroy(br);
          }
      }
  
      /* Add new bridges. */
      for (i = 0; i < cfg->n_bridges; i++) {
          const struct ovsrec_bridge *br_cfg = cfg->bridges[i];
          struct bridge *br = bridge_lookup(br_cfg->name);
          if (!br) {
              bridge_create(br_cfg);
          }
      }
  
      shash_destroy(&new_br);
  }
  
  static void
  iface_set_ofp_port(struct iface *iface, int ofp_port)
  {
      struct bridge *br = iface->port->bridge;
  
      assert(iface->ofp_port < 0 && ofp_port >= 0);
      iface->ofp_port = ofp_port;
      hmap_insert(&br->ifaces, &iface->ofp_port_node, hash_int(ofp_port, 0));
      iface_set_ofport(iface->cfg, ofp_port);
  }
  
  /* Configures 'netdev' based on the "options" column in 'iface_cfg'.
   * Returns 0 if successful, otherwise a positive errno value. */
  static int
  iface_set_netdev_config(const struct ovsrec_interface *iface_cfg,
                          struct netdev *netdev)
  {
      int error;
  
      error = netdev_set_config(netdev, &iface_cfg->options);
      if (error) {
          VLOG_WARN("could not configure network device %s (%s)",
                    iface_cfg->name, strerror(error));
      }
      return error;
  }
  
  /* This function determines whether 'ofproto_port', which is attached to
   * br->ofproto's datapath, is one that we want in 'br'.
   *
   * If it is, it returns true, after creating an iface (if necessary),
   * configuring the iface's netdev according to the iface's options, and setting
   * iface's ofp_port member to 'ofproto_port->ofp_port'.
   *
   * If, on the other hand, 'port' should be removed, it returns false.  The
   * caller should later detach the port from br->ofproto. */
  static bool
  bridge_refresh_one_ofp_port(struct bridge *br,
                              const struct ofproto_port *ofproto_port)
  {
      const char *name = ofproto_port->name;
      const char *type = ofproto_port->type;
      uint16_t ofp_port = ofproto_port->ofp_port;
  
      struct iface *iface = iface_lookup(br, name);
      if (iface) {
          /* Check that the name-to-number mapping is one-to-one. */
          if (iface->ofp_port >= 0) {
              VLOG_WARN("bridge %s: interface %s reported twice",
                        br->name, name);
              return false;
          } else if (iface_from_ofp_port(br, ofp_port)) {
              VLOG_WARN("bridge %s: interface %"PRIu16" reported twice",
                        br->name, ofp_port);
              return false;
          }
  
          /* There's a configured interface named 'name'. */
          if (strcmp(type, iface->type)
              || iface_set_netdev_config(iface->cfg, iface->netdev)) {
              /* It's the wrong type, or it's the right type but can't be
               * configured as the user requested, so we must destroy it. */
              return false;
          } else {
              /* It's the right type and configured correctly.  keep it. */
              iface_set_ofp_port(iface, ofp_port);
              return true;
          }
      } else if (bridge_has_bond_fake_iface(br, name)
                 && !strcmp(type, "internal")) {
          /* It's a bond fake iface.  Keep it. */
          return true;
      } else {
          /* There's no configured interface named 'name', but there might be an
           * interface of that name queued to be created.
           *
           * If there is, and it has the correct type, then try to configure it
           * and add it.  If that's successful, we'll keep it.  Otherwise, we'll
           * delete it and later try to re-add it. */
          struct if_cfg *if_cfg = if_cfg_lookup(br, name);
          return (if_cfg
                  && !strcmp(type, iface_get_type(if_cfg->cfg, br->cfg))
                  && iface_create(br, if_cfg, ofp_port));
      }
  }
  
  /* Update bridges "if_cfg"s, "struct port"s, and "struct iface"s to be
   * consistent with the ofp_ports in "br->ofproto". */
  static void
  bridge_refresh_ofp_port(struct bridge *br)
  {
      struct ofproto_port_dump dump;
      struct ofproto_port ofproto_port;
      struct port *port, *port_next;
  
      /* Clear each "struct iface"s ofp_port so we can get its correct value. */
      hmap_clear(&br->ifaces);
      HMAP_FOR_EACH (port, hmap_node, &br->ports) {
          struct iface *iface;
  
          LIST_FOR_EACH (iface, port_elem, &port->ifaces) {
              iface->ofp_port = -1;
          }
      }
  
      /* Obtain the correct "ofp_port"s from ofproto. Find any if_cfg's which
       * already exist in the datapath and promote them to full fledged "struct
       * iface"s.  Mark ports in the datapath which don't belong as garbage. */
      OFPROTO_PORT_FOR_EACH (&ofproto_port, &dump, br->ofproto) {
          if (!bridge_refresh_one_ofp_port(br, &ofproto_port)) {
              struct ofpp_garbage *garbage = xmalloc(sizeof *garbage);
              garbage->ofp_port = ofproto_port.ofp_port;
              list_push_front(&br->ofpp_garbage, &garbage->list_node);
          }
      }
  
      /* Some ifaces may not have "ofp_port"s in ofproto and therefore don't
       * deserve to have "struct iface"s.  Demote these to "if_cfg"s so that
       * later they can be added to ofproto. */
      HMAP_FOR_EACH_SAFE (port, port_next, hmap_node, &br->ports) {
          struct iface *iface, *iface_next;
  
          LIST_FOR_EACH_SAFE (iface, iface_next, port_elem, &port->ifaces) {
              if (iface->ofp_port < 0) {
                  bridge_queue_if_cfg(br, iface->cfg, port->cfg);
                  iface_destroy(iface);
              }
          }
  
          if (list_is_empty(&port->ifaces)) {
              port_destroy(port);
          }
      }
  }
  
  /* Opens a network device for 'iface_cfg' and configures it.  If '*ofp_portp'
   * is negative, adds the network device to br->ofproto and stores the OpenFlow
   * port number in '*ofp_portp'; otherwise leaves br->ofproto and '*ofp_portp'
   * untouched.
   *
   * If successful, returns 0 and stores the network device in '*netdevp'.  On
   * failure, returns a positive errno value and stores NULL in '*netdevp'. */
  static int
  iface_do_create(const struct bridge *br,
                  const struct ovsrec_interface *iface_cfg,
                  const struct ovsrec_port *port_cfg,
                  int *ofp_portp, struct netdev **netdevp)
  {
      struct netdev *netdev;
      int error;
  
      error = netdev_open(iface_cfg->name,
                          iface_get_type(iface_cfg, br->cfg), &netdev);
      if (error) {
          VLOG_WARN("could not open network device %s (%s)",
                    iface_cfg->name, strerror(error));
          goto error;
      }
  
      error = iface_set_netdev_config(iface_cfg, netdev);
      if (error) {
          goto error;
      }
  
      if (*ofp_portp < 0) {
          uint16_t ofp_port;
  
          error = ofproto_port_add(br->ofproto, netdev, &ofp_port);
          if (error) {
              goto error;
          }
          *ofp_portp = ofp_port;
  
          VLOG_INFO("bridge %s: added interface %s on port %d",
                    br->name, iface_cfg->name, *ofp_portp);
      } else {
          VLOG_DBG("bridge %s: interface %s is on port %d",
                   br->name, iface_cfg->name, *ofp_portp);
      }
  
      if (port_cfg->vlan_mode && !strcmp(port_cfg->vlan_mode, "splinter")) {
          netdev_turn_flags_on(netdev, NETDEV_UP, true);
      }
  
      *netdevp = netdev;
      return 0;
  
  error:
      *netdevp = NULL;
      netdev_close(netdev);
      return error;
  }
  
  /* Creates a new iface on 'br' based on 'if_cfg'.  The new iface has OpenFlow
   * port number 'ofp_port'.  If ofp_port is negative, an OpenFlow port is
   * automatically allocated for the iface.  Takes ownership of and
   * deallocates 'if_cfg'.
   *
   * Return true if an iface is successfully created, false otherwise. */
  static bool
  iface_create(struct bridge *br, struct if_cfg *if_cfg, int ofp_port)
  {
      const struct ovsrec_interface *iface_cfg = if_cfg->cfg;
      const struct ovsrec_port *port_cfg = if_cfg->parent;
  
      struct netdev *netdev;
      struct iface *iface;
      struct port *port;
      int error;
  
      /* Get rid of 'if_cfg' itself.  We already copied out the interesting
       * bits. */
      hmap_remove(&br->if_cfg_todo, &if_cfg->hmap_node);
      free(if_cfg);
  
      /* Do the bits that can fail up front.
       *
       * It's a bit dangerous to call bridge_run_fast() here as ofproto's
       * internal datastructures may not be consistent.  Eventually, when port
       * additions and deletions are cheaper, these calls should be removed. */
      bridge_run_fast();
      assert(!iface_lookup(br, iface_cfg->name));
      error = iface_do_create(br, iface_cfg, port_cfg, &ofp_port, &netdev);
      bridge_run_fast();
      if (error) {
          iface_clear_db_record(iface_cfg);
          return false;
      }
  
      /* Get or create the port structure. */
      port = port_lookup(br, port_cfg->name);
      if (!port) {
          port = port_create(br, port_cfg);
      }
  
      /* Create the iface structure. */
      iface = xzalloc(sizeof *iface);
      list_push_back(&port->ifaces, &iface->port_elem);
      hmap_insert(&br->iface_by_name, &iface->name_node,
                  hash_string(iface_cfg->name, 0));
      iface->port = port;
      iface->name = xstrdup(iface_cfg->name);
      iface->ofp_port = -1;
      iface->netdev = netdev;
      iface->type = iface_get_type(iface_cfg, br->cfg);
      iface->cfg = iface_cfg;
  
      iface_set_ofp_port(iface, ofp_port);
  
      /* Populate initial status in database. */
      iface_refresh_stats(iface);
      iface_refresh_status(iface);
  
      /* Add bond fake iface if necessary. */
      if (port_is_bond_fake_iface(port)) {
          struct ofproto_port ofproto_port;
  
          if (ofproto_port_query_by_name(br->ofproto, port->name,
                                         &ofproto_port)) {
              struct netdev *netdev;
              int error;
  
              error = netdev_open(port->name, "internal", &netdev);
              if (!error) {
                  ofproto_port_add(br->ofproto, netdev, NULL);
                  netdev_close(netdev);
              } else {
                  VLOG_WARN("could not open network device %s (%s)",
                            port->name, strerror(error));
              }
          } else {
              /* Already exists, nothing to do. */
              ofproto_port_destroy(&ofproto_port);
          }
      }
  
      return true;
  }
  
  /* Set Flow eviction threshold */
  static void
  bridge_configure_flow_eviction_threshold(struct bridge *br)
  {
      const char *threshold_str;
      unsigned threshold;
  
      threshold_str = smap_get(&br->cfg->other_config,
                               "flow-eviction-threshold");
      if (threshold_str) {
          threshold = strtoul(threshold_str, NULL, 10);
      } else {
          threshold = OFPROTO_FLOW_EVICTION_THRESHOLD_DEFAULT;
      }
      ofproto_set_flow_eviction_threshold(br->ofproto, threshold);
  }
  
  /* Set forward BPDU option. */
  static void
  bridge_configure_forward_bpdu(struct bridge *br)
  {
      ofproto_set_forward_bpdu(br->ofproto,
                               smap_get_bool(&br->cfg->other_config,
                                             "forward-bpdu",
                                             false));
  }
  
  /* Set MAC aging time for 'br'. */
  static void
  bridge_configure_mac_idle_time(struct bridge *br)
  {
      const char *idle_time_str;
      int idle_time;
  
      idle_time_str = smap_get(&br->cfg->other_config, "mac-aging-time");
      idle_time = (idle_time_str && atoi(idle_time_str)
                   ? atoi(idle_time_str)
                   : MAC_ENTRY_DEFAULT_IDLE_TIME);
      ofproto_set_mac_idle_time(br->ofproto, idle_time);
  }
  
  static void
  bridge_pick_local_hw_addr(struct bridge *br, uint8_t ea[ETH_ADDR_LEN],
                            struct iface **hw_addr_iface)
  {
      struct hmapx mirror_output_ports;
      const char *hwaddr;
      struct port *port;
      bool found_addr = false;
      int error;
      int i;
  
      *hw_addr_iface = NULL;
  
      /* Did the user request a particular MAC? */
      hwaddr = smap_get(&br->cfg->other_config, "hwaddr");
      if (hwaddr && eth_addr_from_string(hwaddr, ea)) {
          if (eth_addr_is_multicast(ea)) {
              VLOG_ERR("bridge %s: cannot set MAC address to multicast "
                       "address "ETH_ADDR_FMT, br->name, ETH_ADDR_ARGS(ea));
          } else if (eth_addr_is_zero(ea)) {
              VLOG_ERR("bridge %s: cannot set MAC address to zero", br->name);
          } else {
              return;
          }
      }
  
      /* Mirror output ports don't participate in picking the local hardware
       * address.  ofproto can't help us find out whether a given port is a
       * mirror output because we haven't configured mirrors yet, so we need to
       * accumulate them ourselves. */
      hmapx_init(&mirror_output_ports);
      for (i = 0; i < br->cfg->n_mirrors; i++) {
          struct ovsrec_mirror *m = br->cfg->mirrors[i];
          if (m->output_port) {
              hmapx_add(&mirror_output_ports, m->output_port);
          }
      }
  
      /* Otherwise choose the minimum non-local MAC address among all of the
       * interfaces. */
      HMAP_FOR_EACH (port, hmap_node, &br->ports) {
          uint8_t iface_ea[ETH_ADDR_LEN];
          struct iface *candidate;
          struct iface *iface;
  
          /* Mirror output ports don't participate. */
          if (hmapx_contains(&mirror_output_ports, port->cfg)) {
              continue;
          }
  
          /* Choose the MAC address to represent the port. */
          iface = NULL;
          if (port->cfg->mac && eth_addr_from_string(port->cfg->mac, iface_ea)) {
              /* Find the interface with this Ethernet address (if any) so that
               * we can provide the correct devname to the caller. */
              LIST_FOR_EACH (candidate, port_elem, &port->ifaces) {
                  uint8_t candidate_ea[ETH_ADDR_LEN];
                  if (!netdev_get_etheraddr(candidate->netdev, candidate_ea)
                      && eth_addr_equals(iface_ea, candidate_ea)) {
                      iface = candidate;
                  }
              }
          } else {
              /* Choose the interface whose MAC address will represent the port.
               * The Linux kernel bonding code always chooses the MAC address of
               * the first slave added to a bond, and the Fedora networking
               * scripts always add slaves to a bond in alphabetical order, so
               * for compatibility we choose the interface with the name that is
               * first in alphabetical order. */
              LIST_FOR_EACH (candidate, port_elem, &port->ifaces) {
                  if (!iface || strcmp(candidate->name, iface->name) < 0) {
                      iface = candidate;
                  }
              }
  
              /* The local port doesn't count (since we're trying to choose its
               * MAC address anyway). */
              if (iface->ofp_port == OFPP_LOCAL) {
                  continue;
              }
  
              /* Grab MAC. */
              error = netdev_get_etheraddr(iface->netdev, iface_ea);
              if (error) {
                  continue;
              }
          }
  
          /* Compare against our current choice. */
          if (!eth_addr_is_multicast(iface_ea) &&
              !eth_addr_is_local(iface_ea) &&
              !eth_addr_is_reserved(iface_ea) &&
              !eth_addr_is_zero(iface_ea) &&
              (!found_addr || eth_addr_compare_3way(iface_ea, ea) < 0))
          {
              memcpy(ea, iface_ea, ETH_ADDR_LEN);
              *hw_addr_iface = iface;
              found_addr = true;
          }
      }
      if (found_addr) {
          VLOG_DBG("bridge %s: using bridge Ethernet address "ETH_ADDR_FMT,
                   br->name, ETH_ADDR_ARGS(ea));
      } else {
          static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 10);
          memcpy(ea, br->default_ea, ETH_ADDR_LEN);
          *hw_addr_iface = NULL;
          VLOG_WARN_RL(&rl, "bridge %s: using default bridge Ethernet "
                       "address "ETH_ADDR_FMT, br->name, ETH_ADDR_ARGS(ea));
      }
  
      hmapx_destroy(&mirror_output_ports);
  }
  
  /* Choose and returns the datapath ID for bridge 'br' given that the bridge
   * Ethernet address is 'bridge_ea'.  If 'bridge_ea' is the Ethernet address of
   * an interface on 'br', then that interface must be passed in as
   * 'hw_addr_iface'; if 'bridge_ea' was derived some other way, then
   * 'hw_addr_iface' must be passed in as a null pointer. */
  static uint64_t
  bridge_pick_datapath_id(struct bridge *br,
                          const uint8_t bridge_ea[ETH_ADDR_LEN],
                          struct iface *hw_addr_iface)
  {
      /*
       * The procedure for choosing a bridge MAC address will, in the most
       * ordinary case, also choose a unique MAC that we can use as a datapath
       * ID.  In some special cases, though, multiple bridges will end up with
       * the same MAC address.  This is OK for the bridges, but it will confuse
       * the OpenFlow controller, because each datapath needs a unique datapath
       * ID.
       *
       * Datapath IDs must be unique.  It is also very desirable that they be
       * stable from one run to the next, so that policy set on a datapath
       * "sticks".
       */
      const char *datapath_id;
      uint64_t dpid;
  
      datapath_id = smap_get(&br->cfg->other_config, "datapath-id");
      if (datapath_id && dpid_from_string(datapath_id, &dpid)) {
          return dpid;
      }
  
      if (!hw_addr_iface) {
          /*
           * A purely internal bridge, that is, one that has no non-virtual
           * network devices on it at all, is difficult because it has no
           * natural unique identifier at all.
           *
           * When the host is a XenServer, we handle this case by hashing the
           * host's UUID with the name of the bridge.  Names of bridges are
           * persistent across XenServer reboots, although they can be reused if
           * an internal network is destroyed and then a new one is later
           * created, so this is fairly effective.
           *
           * When the host is not a XenServer, we punt by using a random MAC
           * address on each run.
           */
          const char *host_uuid = xenserver_get_host_uuid();
          if (host_uuid) {
              char *combined = xasprintf("%s,%s", host_uuid, br->name);
              dpid = dpid_from_hash(combined, strlen(combined));
              free(combined);
              return dpid;
          }
      }
  
      return eth_addr_to_uint64(bridge_ea);
  }
  
  static uint64_t
  dpid_from_hash(const void *data, size_t n)
  {
      uint8_t hash[SHA1_DIGEST_SIZE];
  
      BUILD_ASSERT_DECL(sizeof hash >= ETH_ADDR_LEN);
      sha1_bytes(data, n, hash);
      eth_addr_mark_random(hash);
      return eth_addr_to_uint64(hash);
  }
  
  static void
  iface_refresh_status(struct iface *iface)
  {
      struct smap smap;
  
      enum netdev_features current;
      int64_t bps;
      int mtu;
      int64_t mtu_64;
      int error;
  
      if (iface_is_synthetic(iface)) {
          return;
      }
  
      smap_init(&smap);
  
      if (!netdev_get_drv_info(iface->netdev, &smap)) {
          ovsrec_interface_set_status(iface->cfg, &smap);
      } else {
          ovsrec_interface_set_status(iface->cfg, NULL);
      }
  
      smap_destroy(&smap);
  
      error = netdev_get_features(iface->netdev, &current, NULL, NULL, NULL);
      if (!error) {
          ovsrec_interface_set_duplex(iface->cfg,
                                      netdev_features_is_full_duplex(current)
                                      ? "full" : "half");
          /* warning: uint64_t -> int64_t conversion */
          bps = netdev_features_to_bps(current);
          ovsrec_interface_set_link_speed(iface->cfg, &bps, 1);
      }
      else {
          ovsrec_interface_set_duplex(iface->cfg, NULL);
          ovsrec_interface_set_link_speed(iface->cfg, NULL, 0);
      }
  
      error = netdev_get_mtu(iface->netdev, &mtu);
      if (!error) {
          mtu_64 = mtu;
          ovsrec_interface_set_mtu(iface->cfg, &mtu_64, 1);
      }
      else {
          ovsrec_interface_set_mtu(iface->cfg, NULL, 0);
      }
  }
  
  /* Writes 'iface''s CFM statistics to the database. 'iface' must not be
   * synthetic. */
  static void
  iface_refresh_cfm_stats(struct iface *iface)
  {
      const struct ovsrec_interface *cfg = iface->cfg;
      int fault, opup, error;
      const uint64_t *rmps;
      size_t n_rmps;
      int health;
  
      fault = ofproto_port_get_cfm_fault(iface->port->bridge->ofproto,
                                         iface->ofp_port);
      if (fault >= 0) {
          const char *reasons[CFM_FAULT_N_REASONS];
          bool fault_bool = fault;
          size_t i, j;
  
          j = 0;
          for (i = 0; i < CFM_FAULT_N_REASONS; i++) {
              int reason = 1 << i;
              if (fault & reason) {
                  reasons[j++] = cfm_fault_reason_to_str(reason);
              }
          }
  
          ovsrec_interface_set_cfm_fault(cfg, &fault_bool, 1);
          ovsrec_interface_set_cfm_fault_status(cfg, (char **) reasons, j);
      } else {
          ovsrec_interface_set_cfm_fault(cfg, NULL, 0);
          ovsrec_interface_set_cfm_fault_status(cfg, NULL, 0);
      }
  
      opup = ofproto_port_get_cfm_opup(iface->port->bridge->ofproto,
                                       iface->ofp_port);
      if (opup >= 0) {
          ovsrec_interface_set_cfm_remote_opstate(cfg, opup ? "up" : "down");
      } else {
          ovsrec_interface_set_cfm_remote_opstate(cfg, NULL);
      }
  
      error = ofproto_port_get_cfm_remote_mpids(iface->port->bridge->ofproto,
                                                iface->ofp_port, &rmps, &n_rmps);
      if (error >= 0) {
          ovsrec_interface_set_cfm_remote_mpids(cfg, (const int64_t *)rmps,
                                                n_rmps);
      } else {
          ovsrec_interface_set_cfm_remote_mpids(cfg, NULL, 0);
      }
  
      health = ofproto_port_get_cfm_health(iface->port->bridge->ofproto,
                                          iface->ofp_port);
      if (health >= 0) {
          int64_t cfm_health = health;
          ovsrec_interface_set_cfm_health(cfg, &cfm_health, 1);
      } else {
          ovsrec_interface_set_cfm_health(cfg, NULL, 0);
      }
  }
  
  static void
  iface_refresh_stats(struct iface *iface)
  {
  #define IFACE_STATS                             \
      IFACE_STAT(rx_packets,      "rx_packets")   \
      IFACE_STAT(tx_packets,      "tx_packets")   \
      IFACE_STAT(rx_bytes,        "rx_bytes")     \
      IFACE_STAT(tx_bytes,        "tx_bytes")     \
      IFACE_STAT(rx_dropped,      "rx_dropped")   \
      IFACE_STAT(tx_dropped,      "tx_dropped")   \
      IFACE_STAT(rx_errors,       "rx_errors")    \
      IFACE_STAT(tx_errors,       "tx_errors")    \
      IFACE_STAT(rx_frame_errors, "rx_frame_err") \
      IFACE_STAT(rx_over_errors,  "rx_over_err")  \
      IFACE_STAT(rx_crc_errors,   "rx_crc_err")   \
      IFACE_STAT(collisions,      "collisions")
  
  #define IFACE_STAT(MEMBER, NAME) NAME,
      static char *keys[] = { IFACE_STATS };
  #undef IFACE_STAT
      int64_t values[ARRAY_SIZE(keys)];
      int i;
  
      struct netdev_stats stats;
  
      if (iface_is_synthetic(iface)) {
          return;
      }
  
      /* Intentionally ignore return value, since errors will set 'stats' to
       * all-1s, and we will deal with that correctly below. */
      netdev_get_stats(iface->netdev, &stats);
  
      /* Copy statistics into values[] array. */
      i = 0;
  #define IFACE_STAT(MEMBER, NAME) values[i++] = stats.MEMBER;
      IFACE_STATS;
  #undef IFACE_STAT
      assert(i == ARRAY_SIZE(keys));
  
      ovsrec_interface_set_statistics(iface->cfg, keys, values,
                                      ARRAY_SIZE(keys));
  #undef IFACE_STATS
  }
  
  static void
  br_refresh_stp_status(struct bridge *br)
  {
      struct smap smap = SMAP_INITIALIZER(&smap);
      struct ofproto *ofproto = br->ofproto;
      struct ofproto_stp_status status;
  
      if (ofproto_get_stp_status(ofproto, &status)) {
          return;
      }
  
      if (!status.enabled) {
          ovsrec_bridge_set_status(br->cfg, NULL);
          return;
      }
  
      smap_add_format(&smap, "stp_bridge_id", STP_ID_FMT,
                      STP_ID_ARGS(status.bridge_id));
      smap_add_format(&smap, "stp_designated_root", STP_ID_FMT,
                      STP_ID_ARGS(status.designated_root));
      smap_add_format(&smap, "stp_root_path_cost", "%d", status.root_path_cost);
  
      ovsrec_bridge_set_status(br->cfg, &smap);
      smap_destroy(&smap);
  }
  
  static void
  port_refresh_stp_status(struct port *port)
  {
      struct ofproto *ofproto = port->bridge->ofproto;
      struct iface *iface;
      struct ofproto_port_stp_status status;
      char *keys[3];
      int64_t int_values[3];
      struct smap smap;
  
      if (port_is_synthetic(port)) {
          return;
      }
  
      /* STP doesn't currently support bonds. */
      if (!list_is_singleton(&port->ifaces)) {
          ovsrec_port_set_status(port->cfg, NULL);
          return;
      }
  
      iface = CONTAINER_OF(list_front(&port->ifaces), struct iface, port_elem);
  
      if (ofproto_port_get_stp_status(ofproto, iface->ofp_port, &status)) {
          return;
      }
  
      if (!status.enabled) {
          ovsrec_port_set_status(port->cfg, NULL);
          ovsrec_port_set_statistics(port->cfg, NULL, NULL, 0);
          return;
      }
  
      /* Set Status column. */
      smap_init(&smap);
      smap_add_format(&smap, "stp_port_id", STP_PORT_ID_FMT, status.port_id);
      smap_add(&smap, "stp_state", stp_state_name(status.state));
      smap_add_format(&smap, "stp_sec_in_state", "%u", status.sec_in_state);
      smap_add(&smap, "stp_role", stp_role_name(status.role));
      ovsrec_port_set_status(port->cfg, &smap);
      smap_destroy(&smap);
  
      /* Set Statistics column. */
      keys[0] = "stp_tx_count";
      int_values[0] = status.tx_count;
      keys[1] = "stp_rx_count";
      int_values[1] = status.rx_count;
      keys[2] = "stp_error_count";
      int_values[2] = status.error_count;
  
      ovsrec_port_set_statistics(port->cfg, keys, int_values,
                                 ARRAY_SIZE(int_values));
  }
  
  static bool
  enable_system_stats(const struct ovsrec_open_vswitch *cfg)
  {
      return smap_get_bool(&cfg->other_config, "enable-statistics", false);
  }
  
  static void
  reconfigure_system_stats(const struct ovsrec_open_vswitch *cfg)
  {
      bool enable = enable_system_stats(cfg);
  
      system_stats_enable(enable);
      if (!enable) {
          ovsrec_open_vswitch_set_statistics(cfg, NULL);
      }
  }
  
  static void
  run_system_stats(void)
  {
      const struct ovsrec_open_vswitch *cfg = ovsrec_open_vswitch_first(idl);
      struct smap *stats;
  
      stats = system_stats_run();
      if (stats && cfg) {
          struct ovsdb_idl_txn *txn;
          struct ovsdb_datum datum;
  
          txn = ovsdb_idl_txn_create(idl);
          ovsdb_datum_from_smap(&datum, stats);
          ovsdb_idl_txn_write(&cfg->header_, &ovsrec_open_vswitch_col_statistics,
                              &datum);
          ovsdb_idl_txn_commit(txn);
          ovsdb_idl_txn_destroy(txn);
  
          free(stats);
      }
  }
  
  static inline const char *
  nx_role_to_str(enum nx_role role)
  {
      switch (role) {
      case NX_ROLE_OTHER:
          return "other";
      case NX_ROLE_MASTER:
          return "master";
      case NX_ROLE_SLAVE:
          return "slave";
      default:
          return "*** INVALID ROLE ***";
      }
  }
  
  static void
  refresh_controller_status(void)
  {
      struct bridge *br;
      struct shash info;
      const struct ovsrec_controller *cfg;
  
      shash_init(&info);
  
      /* Accumulate status for controllers on all bridges. */
      HMAP_FOR_EACH (br, node, &all_bridges) {
          ofproto_get_ofproto_controller_info(br->ofproto, &info);
      }
  
      /* Update each controller in the database with current status. */
      OVSREC_CONTROLLER_FOR_EACH(cfg, idl) {
          struct ofproto_controller_info *cinfo =
              shash_find_data(&info, cfg->target);
  
          if (cinfo) {
              struct smap smap = SMAP_INITIALIZER(&smap);
              const char **values = cinfo->pairs.values;
              const char **keys = cinfo->pairs.keys;
              size_t i;
  
              for (i = 0; i < cinfo->pairs.n; i++) {
                  smap_add(&smap, keys[i], values[i]);
              }
  
              ovsrec_controller_set_is_connected(cfg, cinfo->is_connected);
              ovsrec_controller_set_role(cfg, nx_role_to_str(cinfo->role));
              ovsrec_controller_set_status(cfg, &smap);
              smap_destroy(&smap);
          } else {
              ovsrec_controller_set_is_connected(cfg, false);
              ovsrec_controller_set_role(cfg, NULL);
              ovsrec_controller_set_status(cfg, NULL);
          }
      }
  
      ofproto_free_ofproto_controller_info(&info);
  }
  
  static void
  refresh_instant_stats(void)
  {
      static struct ovsdb_idl_txn *txn = NULL;
  
      if (!txn) {
          struct bridge *br;
  
          txn = ovsdb_idl_txn_create(idl);
  
          HMAP_FOR_EACH (br, node, &all_bridges) {
              struct iface *iface;
              struct port *port;
  
              br_refresh_stp_status(br);
  
              HMAP_FOR_EACH (port, hmap_node, &br->ports) {
                  port_refresh_stp_status(port);
              }
  
              HMAP_FOR_EACH (iface, name_node, &br->iface_by_name) {
                  enum netdev_flags flags;
                  const char *link_state;
                  int64_t link_resets;
                  int current, error;
  
                  if (iface_is_synthetic(iface)) {
                      continue;
                  }
  
                  current = ofproto_port_is_lacp_current(br->ofproto,
                                                         iface->ofp_port);
                  if (current >= 0) {
                      bool bl = current;
                      ovsrec_interface_set_lacp_current(iface->cfg, &bl, 1);
                  } else {
                      ovsrec_interface_set_lacp_current(iface->cfg, NULL, 0);
                  }
  
                  error = netdev_get_flags(iface->netdev, &flags);
                  if (!error) {
                      const char *state = flags & NETDEV_UP ? "up" : "down";
                      ovsrec_interface_set_admin_state(iface->cfg, state);
                  } else {
                      ovsrec_interface_set_admin_state(iface->cfg, NULL);
                  }
  
                  link_state = netdev_get_carrier(iface->netdev) ? "up" : "down";
                  ovsrec_interface_set_link_state(iface->cfg, link_state);
  
                  link_resets = netdev_get_carrier_resets(iface->netdev);
                  ovsrec_interface_set_link_resets(iface->cfg, &link_resets, 1);
  
                  iface_refresh_cfm_stats(iface);
              }
          }
      }
  
      if (ovsdb_idl_txn_commit(txn) != TXN_INCOMPLETE) {
          ovsdb_idl_txn_destroy(txn);
          txn = NULL;
      }
  }
  
  /* Performs periodic activity required by bridges that needs to be done with
   * the least possible latency.
   *
   * It makes sense to call this function a couple of times per poll loop, to
   * provide a significant performance boost on some benchmarks with ofprotos
   * that use the ofproto-dpif implementation. */
  void
  bridge_run_fast(void)
  {
      struct bridge *br;
  
      HMAP_FOR_EACH (br, node, &all_bridges) {
          ofproto_run_fast(br->ofproto);
      }
  }
  
  void
  bridge_run(void)
  {
  #ifdef _WIN32
      static struct ovsrec_open_vswitch null_cfg;
      const struct ovsrec_open_vswitch *cfg;
  #else
      static const struct ovsrec_open_vswitch null_cfg;
      const struct ovsrec_open_vswitch *cfg;
  #endif
      struct ovsdb_idl_txn *reconf_txn = NULL;
  
      bool vlan_splinters_changed;
      struct bridge *br;
  
      ovsrec_open_vswitch_init((struct ovsrec_open_vswitch *) &null_cfg);
  
      /* (Re)configure if necessary. */
      if (!reconfiguring) {
          ovsdb_idl_run(idl);
  
          if (ovsdb_idl_is_lock_contended(idl)) {
              static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
              struct bridge *br, *next_br;
  
              VLOG_ERR_RL(&rl, "another ovs-vswitchd process is running, "
                          "disabling this process until it goes away");
  
              HMAP_FOR_EACH_SAFE (br, next_br, node, &all_bridges) {
                  bridge_destroy(br);
              }
              return;
          } else if (!ovsdb_idl_has_lock(idl)) {
              return;
          }
      }
      cfg = ovsrec_open_vswitch_first(idl);
  
      /* Let each bridge do the work that it needs to do. */
      HMAP_FOR_EACH (br, node, &all_bridges) {
          ofproto_run(br->ofproto);
      }
  
      /* Re-configure SSL.  We do this on every trip through the main loop,
       * instead of just when the database changes, because the contents of the
       * key and certificate files can change without the database changing.
       *
       * We do this before bridge_reconfigure() because that function might
       * initiate SSL connections and thus requires SSL to be configured. */
      if (cfg && cfg->ssl) {
          const struct ovsrec_ssl *ssl = cfg->ssl;
  
          stream_ssl_set_key_and_cert(ssl->private_key, ssl->certificate);
          stream_ssl_set_ca_cert_file(ssl->ca_cert, ssl->bootstrap_ca_cert);
      }
  
      if (!reconfiguring) {
          /* If VLAN splinters are in use, then we need to reconfigure if VLAN
           * usage has changed. */
          vlan_splinters_changed = false;
          if (vlan_splinters_enabled_anywhere) {
              HMAP_FOR_EACH (br, node, &all_bridges) {
                  if (ofproto_has_vlan_usage_changed(br->ofproto)) {
                      vlan_splinters_changed = true;
                      break;
                  }
              }
          }
  
          if (ovsdb_idl_get_seqno(idl) != idl_seqno || vlan_splinters_changed) {
              idl_seqno = ovsdb_idl_get_seqno(idl);
              if (cfg) {
                  reconf_txn = ovsdb_idl_txn_create(idl);
                  bridge_reconfigure(cfg);
              } else {
                  /* We still need to reconfigure to avoid dangling pointers to
                   * now-destroyed ovsrec structures inside bridge data. */
                  bridge_reconfigure(&null_cfg);
              }
          }
      }
  
      if (reconfiguring) {
          if (cfg) {
              if (!reconf_txn) {
                  reconf_txn = ovsdb_idl_txn_create(idl);
              }
              if (bridge_reconfigure_continue(cfg)) {
                  ovsrec_open_vswitch_set_cur_cfg(cfg, cfg->next_cfg);
              }
          } else {
              bridge_reconfigure_continue(&null_cfg);
          }
      }
  
      if (reconf_txn) {
          ovsdb_idl_txn_commit(reconf_txn);
          ovsdb_idl_txn_destroy(reconf_txn);
          reconf_txn = NULL;
      }
  
      /* Refresh interface and mirror stats if necessary. */
      if (time_msec() >= iface_stats_timer) {
          if (cfg) {
              struct ovsdb_idl_txn *txn;
  
              txn = ovsdb_idl_txn_create(idl);
              HMAP_FOR_EACH (br, node, &all_bridges) {
                  struct port *port;
                  struct mirror *m;
  
                  HMAP_FOR_EACH (port, hmap_node, &br->ports) {
                      struct iface *iface;
  
                      LIST_FOR_EACH (iface, port_elem, &port->ifaces) {
                          iface_refresh_stats(iface);
                          iface_refresh_status(iface);
                      }
                  }
  
                  HMAP_FOR_EACH (m, hmap_node, &br->mirrors) {
                      mirror_refresh_stats(m);
                  }
  
              }
              refresh_controller_status();
              ovsdb_idl_txn_commit(txn);
              ovsdb_idl_txn_destroy(txn); /* XXX */
          }
  
          iface_stats_timer = time_msec() + IFACE_STATS_INTERVAL;
      }
  
      run_system_stats();
      refresh_instant_stats();
  }
  
  void
  bridge_wait(void)
  {
      ovsdb_idl_wait(idl);
  
      if (reconfiguring) {
          poll_immediate_wake();
      }
  
      if (!hmap_is_empty(&all_bridges)) {
          struct bridge *br;
  
          HMAP_FOR_EACH (br, node, &all_bridges) {
              ofproto_wait(br->ofproto);
          }
          poll_timer_wait_until(iface_stats_timer);
      }
  
      system_stats_wait();
  }
  
  /* Adds some memory usage statistics for bridges into 'usage', for use with
   * memory_report(). */
  void
  bridge_get_memory_usage(struct simap *usage)
  {
      struct bridge *br;
  
      HMAP_FOR_EACH (br, node, &all_bridges) {
          ofproto_get_memory_usage(br->ofproto, usage);
      }
  }
  
  /* QoS unixctl user interface functions. */
  
  struct qos_unixctl_show_cbdata {
      struct ds *ds;
      struct iface *iface;
  };
  
  static void
  qos_unixctl_show_cb(unsigned int queue_id,
                      const struct smap *details,
                      void *aux)
  {
      struct qos_unixctl_show_cbdata *data = aux;
      struct ds *ds = data->ds;
      struct iface *iface = data->iface;
      struct netdev_queue_stats stats;
      struct smap_node *node;
      int error;
  
      ds_put_cstr(ds, "\n");
      if (queue_id) {
          ds_put_format(ds, "Queue %u:\n", queue_id);
      } else {
          ds_put_cstr(ds, "Default:\n");
      }
  
      SMAP_FOR_EACH (node, details) {
          ds_put_format(ds, "\t%s: %s\n", node->key, node->value);
      }
  
      error = netdev_get_queue_stats(iface->netdev, queue_id, &stats);
      if (!error) {
          if (stats.tx_packets != UINT64_MAX) {
              ds_put_format(ds, "\ttx_packets: %"PRIu64"\n", stats.tx_packets);
          }
  
          if (stats.tx_bytes != UINT64_MAX) {
              ds_put_format(ds, "\ttx_bytes: %"PRIu64"\n", stats.tx_bytes);
          }
  
          if (stats.tx_errors != UINT64_MAX) {
              ds_put_format(ds, "\ttx_errors: %"PRIu64"\n", stats.tx_errors);
          }
      } else {
          ds_put_format(ds, "\tFailed to get statistics for queue %u: %s",
                        queue_id, strerror(error));
      }
  }
  
  static void
  qos_unixctl_show(struct unixctl_conn *conn, int argc OVS_UNUSED,
                   const char *argv[], void *aux OVS_UNUSED)
  {
      struct ds ds = DS_EMPTY_INITIALIZER;
      struct smap smap = SMAP_INITIALIZER(&smap);
      struct iface *iface;
      const char *type;
      struct smap_node *node;
      struct qos_unixctl_show_cbdata data;
      int error;
  
      iface = iface_find(argv[1]);
      if (!iface) {
          unixctl_command_reply_error(conn, "no such interface");
          return;
      }
  
      netdev_get_qos(iface->netdev, &type, &smap);
  
      if (*type != '\0') {
          ds_put_format(&ds, "QoS: %s %s\n", iface->name, type);
  
          SMAP_FOR_EACH (node, &smap) {
              ds_put_format(&ds, "%s: %s\n", node->key, node->value);
          }
  
          data.ds = &ds;
          data.iface = iface;
          error = netdev_dump_queues(iface->netdev, qos_unixctl_show_cb, &data);
  
          if (error) {
              ds_put_format(&ds, "failed to dump queues: %s", strerror(error));
          }
          unixctl_command_reply(conn, ds_cstr(&ds));
      } else {
          ds_put_format(&ds, "QoS not configured on %s\n", iface->name);
          unixctl_command_reply_error(conn, ds_cstr(&ds));
      }
  
      smap_destroy(&smap);
      ds_destroy(&ds);
  }
  
  /* Bridge reconfiguration functions. */
  static void
  bridge_create(const struct ovsrec_bridge *br_cfg)
  {
      struct bridge *br;
  
      assert(!bridge_lookup(br_cfg->name));
      br = xzalloc(sizeof *br);
  
      br->name = xstrdup(br_cfg->name);
      br->type = xstrdup(ofproto_normalize_type(br_cfg->datapath_type));
      br->cfg = br_cfg;
  
      /* Derive the default Ethernet address from the bridge's UUID.  This should
       * be unique and it will be stable between ovs-vswitchd runs.  */
      memcpy(br->default_ea, &br_cfg->header_.uuid, ETH_ADDR_LEN);
      eth_addr_mark_random(br->default_ea);
  
      hmap_init(&br->ports);
      hmap_init(&br->ifaces);
      hmap_init(&br->iface_by_name);
      hmap_init(&br->mirrors);
  
      hmap_init(&br->if_cfg_todo);
      list_init(&br->ofpp_garbage);
  
      hmap_insert(&all_bridges, &br->node, hash_string(br->name, 0));
  }
  
  static void
  bridge_destroy(struct bridge *br)
  {
      if (br) {
          struct mirror *mirror, *next_mirror;
          struct port *port, *next_port;
          struct if_cfg *if_cfg, *next_if_cfg;
          struct ofpp_garbage *garbage, *next_garbage;
  
          HMAP_FOR_EACH_SAFE (port, next_port, hmap_node, &br->ports) {
              port_destroy(port);
          }
          HMAP_FOR_EACH_SAFE (mirror, next_mirror, hmap_node, &br->mirrors) {
              mirror_destroy(mirror);
          }
          HMAP_FOR_EACH_SAFE (if_cfg, next_if_cfg, hmap_node, &br->if_cfg_todo) {
              hmap_remove(&br->if_cfg_todo, &if_cfg->hmap_node);
              free(if_cfg);
          }
          LIST_FOR_EACH_SAFE (garbage, next_garbage, list_node,
                              &br->ofpp_garbage) {
              list_remove(&garbage->list_node);
              free(garbage);
          }
  
          hmap_remove(&all_bridges, &br->node);
          ofproto_destroy(br->ofproto);
          hmap_destroy(&br->ifaces);
          hmap_destroy(&br->ports);
          hmap_destroy(&br->iface_by_name);
          hmap_destroy(&br->mirrors);
          hmap_destroy(&br->if_cfg_todo);
          free(br->name);
          free(br->type);
          free(br);
      }
  }
  
  static struct bridge *
  bridge_lookup(const char *name)
  {
      struct bridge *br;
  
      HMAP_FOR_EACH_WITH_HASH (br, node, hash_string(name, 0), &all_bridges) {
          if (!strcmp(br->name, name)) {
              return br;
          }
      }
      return NULL;
  }
  
  /* Handle requests for a listing of all flows known by the OpenFlow
   * stack, including those normally hidden. */
  static void
  bridge_unixctl_dump_flows(struct unixctl_conn *conn, int argc OVS_UNUSED,
                            const char *argv[], void *aux OVS_UNUSED)
  {
      struct bridge *br;
      struct ds results;
  
      br = bridge_lookup(argv[1]);
      if (!br) {
          unixctl_command_reply_error(conn, "Unknown bridge");
          return;
      }
  
      ds_init(&results);
      ofproto_get_all_flows(br->ofproto, &results);
  
      unixctl_command_reply(conn, ds_cstr(&results));
      ds_destroy(&results);
  }
  
  /* "bridge/reconnect [BRIDGE]": makes BRIDGE drop all of its controller
   * connections and reconnect.  If BRIDGE is not specified, then all bridges
   * drop their controller connections and reconnect. */
  static void
  bridge_unixctl_reconnect(struct unixctl_conn *conn, int argc,
                           const char *argv[], void *aux OVS_UNUSED)
  {
      struct bridge *br;
      if (argc > 1) {
          br = bridge_lookup(argv[1]);
          if (!br) {
              unixctl_command_reply_error(conn,  "Unknown bridge");
              return;
          }
          ofproto_reconnect_controllers(br->ofproto);
      } else {
          HMAP_FOR_EACH (br, node, &all_bridges) {
              ofproto_reconnect_controllers(br->ofproto);
          }
      }
      unixctl_command_reply(conn, NULL);
  }
  
  static size_t
  bridge_get_controllers(const struct bridge *br,
                         struct ovsrec_controller ***controllersp)
  {
      struct ovsrec_controller **controllers;
      size_t n_controllers;
  
      controllers = br->cfg->controller;
      n_controllers = br->cfg->n_controller;
  
      if (n_controllers == 1 && !strcmp(controllers[0]->target, "none")) {
          controllers = NULL;
          n_controllers = 0;
      }
  
      if (controllersp) {
          *controllersp = controllers;
      }
      return n_controllers;
  }
  
  static void
  bridge_queue_if_cfg(struct bridge *br,
                      const struct ovsrec_interface *cfg,
                      const struct ovsrec_port *parent)
  {
      struct if_cfg *if_cfg = xmalloc(sizeof *if_cfg);
  
      if_cfg->cfg = cfg;
      if_cfg->parent = parent;
      hmap_insert(&br->if_cfg_todo, &if_cfg->hmap_node,
                  hash_string(if_cfg->cfg->name, 0));
  }
  
  /* Deletes "struct port"s and "struct iface"s under 'br' which aren't
   * consistent with 'br->cfg'.  Updates 'br->if_cfg_queue' with interfaces which
   * 'br' needs to complete its configuration. */
  static void
  bridge_add_del_ports(struct bridge *br,
                       const unsigned long int *splinter_vlans)
  {
      struct shash_node *port_node;
      struct port *port, *next;
      struct shash new_ports;
      size_t i;
  
      assert(hmap_is_empty(&br->if_cfg_todo));
  
      /* Collect new ports. */
      shash_init(&new_ports);
      for (i = 0; i < br->cfg->n_ports; i++) {
          const char *name = br->cfg->ports[i]->name;
          if (!shash_add_once(&new_ports, name, br->cfg->ports[i])) {
              VLOG_WARN("bridge %s: %s specified twice as bridge port",
                        br->name, name);
          }
      }
      if (bridge_get_controllers(br, NULL)
          && !shash_find(&new_ports, br->name)) {
          VLOG_WARN("bridge %s: no port named %s, synthesizing one",
                    br->name, br->name);
  
          ovsrec_interface_init(&br->synth_local_iface);
          ovsrec_port_init(&br->synth_local_port);
  
          br->synth_local_port.interfaces = &br->synth_local_ifacep;
          br->synth_local_port.n_interfaces = 1;
          br->synth_local_port.name = br->name;
  
          br->synth_local_iface.name = br->name;
          br->synth_local_iface.type = "internal";
  
          br->synth_local_ifacep = &br->synth_local_iface;
  
          shash_add(&new_ports, br->name, &br->synth_local_port);
      }
  
      if (splinter_vlans) {
          add_vlan_splinter_ports(br, splinter_vlans, &new_ports);
      }
  
      /* Get rid of deleted ports.
       * Get rid of deleted interfaces on ports that still exist. */
      HMAP_FOR_EACH_SAFE (port, next, hmap_node, &br->ports) {
          port->cfg = shash_find_data(&new_ports, port->name);
          if (!port->cfg) {
              port_destroy(port);
          } else {
              port_del_ifaces(port);
          }
      }
  
      /* Update iface->cfg and iface->type in interfaces that still exist.
       * Add new interfaces to creation queue. */
      SHASH_FOR_EACH (port_node, &new_ports) {
          const struct ovsrec_port *port = port_node->data;
          size_t i;
  
          for (i = 0; i < port->n_interfaces; i++) {
              const struct ovsrec_interface *cfg = port->interfaces[i];
              struct iface *iface = iface_lookup(br, cfg->name);
              const char *type = iface_get_type(cfg, br->cfg);
  
              if (iface) {
                  iface->cfg = cfg;
                  iface->type = type;
              } else if (!strcmp(type, "null")) {
                  VLOG_WARN_ONCE("%s: The null interface type is deprecated and"
                                 " may be removed in February 2013. Please email"
                                 " dev@openvswitch.org with concerns.",
                                 cfg->name);
              } else {
                  bridge_queue_if_cfg(br, cfg, port);
              }
          }
      }
  
      shash_destroy(&new_ports);
  }
  
  /* Initializes 'oc' appropriately as a management service controller for
   * 'br'.
   *
   * The caller must free oc->target when it is no longer needed. */
  static void
  bridge_ofproto_controller_for_mgmt(const struct bridge *br,
                                     struct ofproto_controller *oc)
  {
      oc->target = xasprintf("punix:%s/%s.mgmt", ovs_rundir(), br->name);
      oc->max_backoff = 0;
      oc->probe_interval = 60;
      oc->band = OFPROTO_OUT_OF_BAND;
      oc->rate_limit = 0;
      oc->burst_limit = 0;
      oc->enable_async_msgs = true;
  }
  
  /* Converts ovsrec_controller 'c' into an ofproto_controller in 'oc'.  */
  static void
  bridge_ofproto_controller_from_ovsrec(const struct ovsrec_controller *c,
                                        struct ofproto_controller *oc)
  {
      int dscp;
  
      oc->target = c->target;
      oc->max_backoff = c->max_backoff ? *c->max_backoff / 1000 : 8;
      oc->probe_interval = c->inactivity_probe ? *c->inactivity_probe / 1000 : 5;
      oc->band = (!c->connection_mode || !strcmp(c->connection_mode, "in-band")
                  ? OFPROTO_IN_BAND : OFPROTO_OUT_OF_BAND);
      oc->rate_limit = c->controller_rate_limit ? *c->controller_rate_limit : 0;
      oc->burst_limit = (c->controller_burst_limit
                         ? *c->controller_burst_limit : 0);
      oc->enable_async_msgs = (!c->enable_async_messages
                               || *c->enable_async_messages);
      dscp = smap_get_int(&c->other_config, "dscp", DSCP_DEFAULT);
      if (dscp < 0 || dscp > 63) {
          dscp = DSCP_DEFAULT;
      }
      oc->dscp = dscp;
  }
  
  /* Configures the IP stack for 'br''s local interface properly according to the
   * configuration in 'c'.  */
  static void
  bridge_configure_local_iface_netdev(struct bridge *br,
                                      struct ovsrec_controller *c)
  {
      struct netdev *netdev;
      struct in_addr mask, gateway;
  
      struct iface *local_iface;
      struct in_addr ip;
  
      /* If there's no local interface or no IP address, give up. */
      local_iface = iface_from_ofp_port(br, OFPP_LOCAL);
      if (!local_iface || !c->local_ip || !inet_aton(c->local_ip, &ip)) {
          return;
      }
  
      /* Bring up the local interface. */
      netdev = local_iface->netdev;
      netdev_turn_flags_on(netdev, NETDEV_UP, true);
  
      /* Configure the IP address and netmask. */
      if (!c->local_netmask
          || !inet_aton(c->local_netmask, &mask)
          || !mask.s_addr) {
          mask.s_addr = guess_netmask(ip.s_addr);
      }
      if (!netdev_set_in4(netdev, ip, mask)) {
          VLOG_INFO("bridge %s: configured IP address "IP_FMT", netmask "IP_FMT,
                    br->name, IP_ARGS(&ip.s_addr), IP_ARGS(&mask.s_addr));
      }
  
      /* Configure the default gateway. */
      if (c->local_gateway
          && inet_aton(c->local_gateway, &gateway)
          && gateway.s_addr) {
          if (!netdev_add_router(netdev, gateway)) {
              VLOG_INFO("bridge %s: configured gateway "IP_FMT,
                        br->name, IP_ARGS(&gateway.s_addr));
          }
      }
  }
  
  /* Returns true if 'a' and 'b' are the same except that any number of slashes
   * in either string are treated as equal to any number of slashes in the other,
   * e.g. "x///y" is equal to "x/y". */
  static bool
  equal_pathnames(const char *a, const char *b)
  {
      while (*a == *b) {
          if (*a == '/') {
              a += strspn(a, "/");
              b += strspn(b, "/");
          } else if (*a == '\0') {
              return true;
          } else {
              a++;
              b++;
          }
      }
      return false;
  }
  
  static void
  bridge_configure_remotes(struct bridge *br,
                           const struct sockaddr_in *managers, size_t n_managers)
  {
      bool disable_in_band;
  
      struct ovsrec_controller **controllers;
      size_t n_controllers;
  
      enum ofproto_fail_mode fail_mode;
  
      struct ofproto_controller *ocs;
      size_t n_ocs;
      size_t i;
  
      /* Check if we should disable in-band control on this bridge. */
      disable_in_band = smap_get_bool(&br->cfg->other_config, "disable-in-band",
                                      false);
  
      /* Set OpenFlow queue ID for in-band control. */
      ofproto_set_in_band_queue(br->ofproto,
                                smap_get_int(&br->cfg->other_config,
                                             "in-band-queue", -1));
  
      if (disable_in_band) {
          ofproto_set_extra_in_band_remotes(br->ofproto, NULL, 0);
      } else {
          ofproto_set_extra_in_band_remotes(br->ofproto, managers, n_managers);
      }
  
      n_controllers = bridge_get_controllers(br, &controllers);
  
      ocs = xmalloc((n_controllers + 1) * sizeof *ocs);
      n_ocs = 0;
  
      bridge_ofproto_controller_for_mgmt(br, &ocs[n_ocs++]);
      for (i = 0; i < n_controllers; i++) {
          struct ovsrec_controller *c = controllers[i];
  
          if (!strncmp(c->target, "punix:", 6)
              || !strncmp(c->target, "unix:", 5)) {
              static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
              char *whitelist;
  
              whitelist = xasprintf("unix:%s/%s.controller",
                                    ovs_rundir(), br->name);
              if (!equal_pathnames(c->target, whitelist)) {
                  /* Prevent remote ovsdb-server users from accessing arbitrary
                   * Unix domain sockets and overwriting arbitrary local
                   * files. */
                  VLOG_ERR_RL(&rl, "bridge %s: Not adding Unix domain socket "
                              "controller \"%s\" due to possibility for remote "
                              "exploit.  Instead, specify whitelisted \"%s\" or "
                              "connect to \"unix:%s/%s.mgmt\" (which is always "
                              "available without special configuration).",
                              br->name, c->target, whitelist,
                              ovs_rundir(), br->name);
                  free(whitelist);
                  continue;
              }
  
              free(whitelist);
          }
  
          bridge_configure_local_iface_netdev(br, c);
          bridge_ofproto_controller_from_ovsrec(c, &ocs[n_ocs]);
          if (disable_in_band) {
              ocs[n_ocs].band = OFPROTO_OUT_OF_BAND;
          }
          n_ocs++;
      }
  
      ofproto_set_controllers(br->ofproto, ocs, n_ocs);
      free(ocs[0].target); /* From bridge_ofproto_controller_for_mgmt(). */
      free(ocs);
  
      /* Set the fail-mode. */
      fail_mode = !br->cfg->fail_mode
                  || !strcmp(br->cfg->fail_mode, "standalone")
                      ? OFPROTO_FAIL_STANDALONE
                      : OFPROTO_FAIL_SECURE;
      ofproto_set_fail_mode(br->ofproto, fail_mode);
  
      /* Configure OpenFlow controller connection snooping. */
      if (!ofproto_has_snoops(br->ofproto)) {
          struct sset snoops;
  
          sset_init(&snoops);
          sset_add_and_free(&snoops, xasprintf("punix:%s/%s.snoop",
                                               ovs_rundir(), br->name));
          ofproto_set_snoops(br->ofproto, &snoops);
          sset_destroy(&snoops);
      }
  }
  
  static void
  bridge_configure_tables(struct bridge *br)
  {
      static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
      int n_tables;
      int i, j;
  
      n_tables = ofproto_get_n_tables(br->ofproto);
      j = 0;
      for (i = 0; i < n_tables; i++) {
          struct ofproto_table_settings s;
  
          s.name = NULL;
          s.max_flows = UINT_MAX;
          s.groups = NULL;
          s.n_groups = 0;
  
          if (j < br->cfg->n_flow_tables && i == br->cfg->key_flow_tables[j]) {
              struct ovsrec_flow_table *cfg = br->cfg->value_flow_tables[j++];
  
              s.name = cfg->name;
              if (cfg->n_flow_limit && *cfg->flow_limit < UINT_MAX) {
                  s.max_flows = *cfg->flow_limit;
              }
              if (cfg->overflow_policy
                  && !strcmp(cfg->overflow_policy, "evict")) {
                  size_t k;
  
                  s.groups = xmalloc(cfg->n_groups * sizeof *s.groups);
                  for (k = 0; k < cfg->n_groups; k++) {
                      const char *string = cfg->groups[k];
                      char *msg;
  
                      msg = mf_parse_subfield__(&s.groups[k], &string);
                      if (msg) {
                          VLOG_WARN_RL(&rl, "bridge %s table %d: error parsing "
                                       "'groups' (%s)", br->name, i, msg);
                          free(msg);
                      } else if (*string) {
                          VLOG_WARN_RL(&rl, "bridge %s table %d: 'groups' "
                                       "element '%s' contains trailing garbage",
                                       br->name, i, cfg->groups[k]);
                      } else {
                          s.n_groups++;
                      }
                  }
              }
          }
  
          ofproto_configure_table(br->ofproto, i, &s);
  
          free(s.groups);
      }
      for (; j < br->cfg->n_flow_tables; j++) {
          VLOG_WARN_RL(&rl, "bridge %s: ignoring configuration for flow table "
                       "%"PRId64" not supported by this datapath", br->name,
                       br->cfg->key_flow_tables[j]);
      }
  }
  
  /* Port functions. */
  
  static struct port *
  port_create(struct bridge *br, const struct ovsrec_port *cfg)
  {
      struct port *port;
  
      port = xzalloc(sizeof *port);
      port->bridge = br;
      port->name = xstrdup(cfg->name);
      port->cfg = cfg;
      list_init(&port->ifaces);
  
      hmap_insert(&br->ports, &port->hmap_node, hash_string(port->name, 0));
      return port;
  }
  
  /* Deletes interfaces from 'port' that are no longer configured for it. */
  static void
  port_del_ifaces(struct port *port)
  {
      struct iface *iface, *next;
      struct sset new_ifaces;
      size_t i;
  
      /* Collect list of new interfaces. */
      sset_init(&new_ifaces);
      for (i = 0; i < port->cfg->n_interfaces; i++) {
          const char *name = port->cfg->interfaces[i]->name;
          const char *type = port->cfg->interfaces[i]->type;
          if (strcmp(type, "null")) {
              sset_add(&new_ifaces, name);
          }
      }
  
      /* Get rid of deleted interfaces. */
      LIST_FOR_EACH_SAFE (iface, next, port_elem, &port->ifaces) {
          if (!sset_contains(&new_ifaces, iface->name)) {
              iface_destroy(iface);
          }
      }
  
      sset_destroy(&new_ifaces);
  }
  
  static void
  port_destroy(struct port *port)
  {
      if (port) {
          struct bridge *br = port->bridge;
          struct iface *iface, *next;
  
          if (br->ofproto) {
              ofproto_bundle_unregister(br->ofproto, port);
          }
  
          LIST_FOR_EACH_SAFE (iface, next, port_elem, &port->ifaces) {
              iface_destroy(iface);
          }
  
          hmap_remove(&br->ports, &port->hmap_node);
          free(port->name);
          free(port);
      }
  }
  
  static struct port *
  port_lookup(const struct bridge *br, const char *name)
  {
      struct port *port;
  
      HMAP_FOR_EACH_WITH_HASH (port, hmap_node, hash_string(name, 0),
                               &br->ports) {
          if (!strcmp(port->name, name)) {
              return port;
          }
      }
      return NULL;
  }
  
  static bool
  enable_lacp(struct port *port, bool *activep)
  {
      if (!port->cfg->lacp) {
          /* XXX when LACP implementation has been sufficiently tested, enable by
           * default and make active on bonded ports. */
          return false;
      } else if (!strcmp(port->cfg->lacp, "off")) {
          return false;
      } else if (!strcmp(port->cfg->lacp, "active")) {
          *activep = true;
          return true;
      } else if (!strcmp(port->cfg->lacp, "passive")) {
          *activep = false;
          return true;
      } else {
          VLOG_WARN("port %s: unknown LACP mode %s",
                    port->name, port->cfg->lacp);
          return false;
      }
  }
  
  static struct lacp_settings *
  port_configure_lacp(struct port *port, struct lacp_settings *s)
  {
      const char *lacp_time, *system_id;
      int priority;
  
      if (!enable_lacp(port, &s->active)) {
          return NULL;
      }
  
      s->name = port->name;
  
      system_id = smap_get(&port->cfg->other_config, "lacp-system-id");
      if (system_id) {
          if (sscanf(system_id, ETH_ADDR_SCAN_FMT,
                     ETH_ADDR_SCAN_ARGS(s->id)) != ETH_ADDR_SCAN_COUNT) {
              VLOG_WARN("port %s: LACP system ID (%s) must be an Ethernet"
                        " address.", port->name, system_id);
              return NULL;
          }
      } else {
          memcpy(s->id, port->bridge->ea, ETH_ADDR_LEN);
      }
  
      if (eth_addr_is_zero(s->id)) {
          VLOG_WARN("port %s: Invalid zero LACP system ID.", port->name);
          return NULL;
      }
  
      /* Prefer bondable links if unspecified. */
      priority = smap_get_int(&port->cfg->other_config, "lacp-system-priority",
                              0);
      s->priority = (priority > 0 && priority <= UINT16_MAX
                     ? priority
                     : UINT16_MAX - !list_is_short(&port->ifaces));
  
      lacp_time = smap_get(&port->cfg->other_config, "lacp-time");
      s->fast = lacp_time && !strcasecmp(lacp_time, "fast");
      return s;
  }
  
  static void
  iface_configure_lacp(struct iface *iface, struct lacp_slave_settings *s)
  {
      int priority, portid, key;
  
      portid = smap_get_int(&iface->cfg->other_config, "lacp-port-id", 0);
      priority = smap_get_int(&iface->cfg->other_config, "lacp-port-priority",
                              0);
      key = smap_get_int(&iface->cfg->other_config, "lacp-aggregation-key", 0);
  
      if (portid <= 0 || portid > UINT16_MAX) {
          portid = iface->ofp_port;
      }
  
      if (priority <= 0 || priority > UINT16_MAX) {
          priority = UINT16_MAX;
      }
  
      if (key < 0 || key > UINT16_MAX) {
          key = 0;
      }
  
      s->name = iface->name;
      s->id = portid;
      s->priority = priority;
      s->key = key;
  }
  
  static void
  port_configure_bond(struct port *port, struct bond_settings *s,
                      uint32_t *bond_stable_ids)
  {
      const char *detect_s;
      struct iface *iface;
      int miimon_interval;
      size_t i;
  
      s->name = port->name;
      s->balance = BM_AB;
      if (port->cfg->bond_mode) {
          if (!bond_mode_from_string(&s->balance, port->cfg->bond_mode)) {
              VLOG_WARN("port %s: unknown bond_mode %s, defaulting to %s",
                        port->name, port->cfg->bond_mode,
                        bond_mode_to_string(s->balance));
          }
      } else {
          static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
  
          /* XXX: Post version 1.5.*, the default bond_mode changed from SLB to
           * active-backup. At some point we should remove this warning. */
          VLOG_WARN_RL(&rl, "port %s: Using the default bond_mode %s. Note that"
                       " in previous versions, the default bond_mode was"
                       " balance-slb", port->name,
                       bond_mode_to_string(s->balance));
      }
      if (s->balance == BM_SLB && port->bridge->cfg->n_flood_vlans) {
          VLOG_WARN("port %s: SLB bonds are incompatible with flood_vlans, "
                    "please use another bond type or disable flood_vlans",
                    port->name);
      }
  
      miimon_interval = smap_get_int(&port->cfg->other_config,
                                     "bond-miimon-interval", 0);
      if (miimon_interval <= 0) {
          miimon_interval = 200;
      }
  
      detect_s = smap_get(&port->cfg->other_config, "bond-detect-mode");
      if (!detect_s || !strcmp(detect_s, "carrier")) {
          miimon_interval = 0;
      } else if (strcmp(detect_s, "miimon")) {
          VLOG_WARN("port %s: unsupported bond-detect-mode %s, "
                    "defaulting to carrier", port->name, detect_s);
          miimon_interval = 0;
      }
  
      s->up_delay = MAX(0, port->cfg->bond_updelay);
      s->down_delay = MAX(0, port->cfg->bond_downdelay);
      s->basis = smap_get_int(&port->cfg->other_config, "bond-hash-basis", 0);
      s->rebalance_interval = smap_get_int(&port->cfg->other_config,
                                             "bond-rebalance-interval", 10000);
      if (s->rebalance_interval && s->rebalance_interval < 1000) {
          s->rebalance_interval = 1000;
      }
  
      s->fake_iface = port->cfg->bond_fake_iface;
  
      i = 0;
      LIST_FOR_EACH (iface, port_elem, &port->ifaces) {
          long long stable_id;
  
          stable_id = smap_get_int(&iface->cfg->other_config, "bond-stable-id",
                                   0);
          if (stable_id <= 0 || stable_id >= UINT32_MAX) {
              stable_id = iface->ofp_port;
          }
          bond_stable_ids[i++] = stable_id;
  
          netdev_set_miimon_interval(iface->netdev, miimon_interval);
      }
  }
  
  /* Returns true if 'port' is synthetic, that is, if we constructed it locally
   * instead of obtaining it from the database. */
  static bool
  port_is_synthetic(const struct port *port)
  {
      return ovsdb_idl_row_is_synthetic(&port->cfg->header_);
  }
  
  /* Interface functions. */
  
  /* Returns the correct network device type for interface 'iface' in bridge
   * 'br'. */
  static const char *
  iface_get_type(const struct ovsrec_interface *iface,
                 const struct ovsrec_bridge *br)
  {
      /* The local port always has type "internal".  Other ports take their type
       * from the database and default to "system" if none is specified. */
      return (!strcmp(iface->name, br->name) ? "internal"
              : iface->type[0] ? iface->type
              : "system");
  }
  
  static void
  iface_destroy(struct iface *iface)
  {
      if (iface) {
          struct port *port = iface->port;
          struct bridge *br = port->bridge;
  
          if (br->ofproto && iface->ofp_port >= 0) {
              ofproto_port_unregister(br->ofproto, iface->ofp_port);
          }
  
          if (iface->ofp_port >= 0) {
              hmap_remove(&br->ifaces, &iface->ofp_port_node);
          }
  
          list_remove(&iface->port_elem);
          hmap_remove(&br->iface_by_name, &iface->name_node);
  
          netdev_close(iface->netdev);
  
          free(iface->name);
          free(iface);
      }
  }
  
  static struct iface *
  iface_lookup(const struct bridge *br, const char *name)
  {
      struct iface *iface;
  
      HMAP_FOR_EACH_WITH_HASH (iface, name_node, hash_string(name, 0),
                               &br->iface_by_name) {
          if (!strcmp(iface->name, name)) {
              return iface;
          }
      }
  
      return NULL;
  }
  
  static struct iface *
  iface_find(const char *name)
  {
      const struct bridge *br;
  
      HMAP_FOR_EACH (br, node, &all_bridges) {
          struct iface *iface = iface_lookup(br, name);
  
          if (iface) {
              return iface;
          }
      }
      return NULL;
  }
  
  static struct if_cfg *
  if_cfg_lookup(const struct bridge *br, const char *name)
  {
      struct if_cfg *if_cfg;
  
      HMAP_FOR_EACH_WITH_HASH (if_cfg, hmap_node, hash_string(name, 0),
                               &br->if_cfg_todo) {
          if (!strcmp(if_cfg->cfg->name, name)) {
              return if_cfg;
          }
      }
  
      return NULL;
  }
  
  static struct iface *
  iface_from_ofp_port(const struct bridge *br, uint16_t ofp_port)
  {
      struct iface *iface;
  
      HMAP_FOR_EACH_IN_BUCKET (iface, ofp_port_node,
                               hash_int(ofp_port, 0), &br->ifaces) {
          if (iface->ofp_port == ofp_port) {
              return iface;
          }
      }
      return NULL;
  }
  
  /* Set Ethernet address of 'iface', if one is specified in the configuration
   * file. */
  static void
  iface_set_mac(struct iface *iface)
  {
      uint8_t ea[ETH_ADDR_LEN];
  
      if (!strcmp(iface->type, "internal")
          && iface->cfg->mac && eth_addr_from_string(iface->cfg->mac, ea)) {
          if (iface->ofp_port == OFPP_LOCAL) {
              VLOG_ERR("interface %s: ignoring mac in Interface record "
                       "(use Bridge record to set local port's mac)",
                       iface->name);
          } else if (eth_addr_is_multicast(ea)) {
              VLOG_ERR("interface %s: cannot set MAC to multicast address",
                       iface->name);
          } else {
              int error = netdev_set_etheraddr(iface->netdev, ea);
              if (error) {
                  VLOG_ERR("interface %s: setting MAC failed (%s)",
                           iface->name, strerror(error));
              }
          }
      }
  }
  
  /* Sets the ofport column of 'if_cfg' to 'ofport'. */
  static void
  iface_set_ofport(const struct ovsrec_interface *if_cfg, int64_t ofport)
  {
      if (if_cfg && !ovsdb_idl_row_is_synthetic(&if_cfg->header_)) {
          ovsrec_interface_set_ofport(if_cfg, &ofport, 1);
      }
  }
  
  /* Clears all of the fields in 'if_cfg' that indicate interface status, and
   * sets the "ofport" field to -1.
   *
   * This is appropriate when 'if_cfg''s interface cannot be created or is
   * otherwise invalid. */
  static void
  iface_clear_db_record(const struct ovsrec_interface *if_cfg)
  {
      if (!ovsdb_idl_row_is_synthetic(&if_cfg->header_)) {
          iface_set_ofport(if_cfg, -1);
          ovsrec_interface_set_status(if_cfg, NULL);
          ovsrec_interface_set_admin_state(if_cfg, NULL);
          ovsrec_interface_set_duplex(if_cfg, NULL);
          ovsrec_interface_set_link_speed(if_cfg, NULL, 0);
          ovsrec_interface_set_link_state(if_cfg, NULL);
          ovsrec_interface_set_mtu(if_cfg, NULL, 0);
          ovsrec_interface_set_cfm_fault(if_cfg, NULL, 0);
          ovsrec_interface_set_cfm_fault_status(if_cfg, NULL, 0);
          ovsrec_interface_set_cfm_remote_mpids(if_cfg, NULL, 0);
          ovsrec_interface_set_lacp_current(if_cfg, NULL, 0);
          ovsrec_interface_set_statistics(if_cfg, NULL, NULL, 0);
      }
  }
  
  struct iface_delete_queues_cbdata {
      struct netdev *netdev;
      const struct ovsdb_datum *queues;
  };
  
  static bool
  queue_ids_include(const struct ovsdb_datum *queues, int64_t target)
  {
      union ovsdb_atom atom;
  
      atom.integer = target;
      return ovsdb_datum_find_key(queues, &atom, OVSDB_TYPE_INTEGER) != UINT_MAX;
  }
  
  static void
  iface_delete_queues(unsigned int queue_id,
                      const struct smap *details OVS_UNUSED, void *cbdata_)
  {
      struct iface_delete_queues_cbdata *cbdata = cbdata_;
  
      if (!queue_ids_include(cbdata->queues, queue_id)) {
          netdev_delete_queue(cbdata->netdev, queue_id);
      }
  }
  
  static void
  iface_configure_qos(struct iface *iface, const struct ovsrec_qos *qos)
  {
      struct ofpbuf queues_buf;
  
      ofpbuf_init(&queues_buf, 0);
  
      if (!qos || qos->type[0] == '\0' || qos->n_queues < 1) {
          netdev_set_qos(iface->netdev, NULL, NULL);
      } else {
          struct iface_delete_queues_cbdata cbdata;
          bool queue_zero;
          size_t i;
  
          /* Configure top-level Qos for 'iface'. */
          netdev_set_qos(iface->netdev, qos->type, &qos->other_config);
  
          /* Deconfigure queues that were deleted. */
          cbdata.netdev = iface->netdev;
          cbdata.queues = ovsrec_qos_get_queues(qos, OVSDB_TYPE_INTEGER,
                                                OVSDB_TYPE_UUID);
          netdev_dump_queues(iface->netdev, iface_delete_queues, &cbdata);
  
          /* Configure queues for 'iface'. */
          queue_zero = false;
          for (i = 0; i < qos->n_queues; i++) {
              const struct ovsrec_queue *queue = qos->value_queues[i];
              unsigned int queue_id = qos->key_queues[i];
  
              if (queue_id == 0) {
                  queue_zero = true;
              }
  
              if (queue->n_dscp == 1) {
                  struct ofproto_port_queue *port_queue;
  
                  port_queue = ofpbuf_put_uninit(&queues_buf,
                                                 sizeof *port_queue);
                  port_queue->queue = queue_id;
                  port_queue->dscp = queue->dscp[0];
              }
  
              netdev_set_queue(iface->netdev, queue_id, &queue->other_config);
          }
          if (!queue_zero) {
              struct smap details;
  
              smap_init(&details);
              netdev_set_queue(iface->netdev, 0, &details);
              smap_destroy(&details);
          }
      }
  
      if (iface->ofp_port >= 0) {
          const struct ofproto_port_queue *port_queues = queues_buf.data;
          size_t n_queues = queues_buf.size / sizeof *port_queues;
  
          ofproto_port_set_queues(iface->port->bridge->ofproto, iface->ofp_port,
                                  port_queues, n_queues);
      }
  
      netdev_set_policing(iface->netdev,
                          iface->cfg->ingress_policing_rate,
                          iface->cfg->ingress_policing_burst);
  
      ofpbuf_uninit(&queues_buf);
  }
  
  static void
  iface_configure_cfm(struct iface *iface)
  {
      const struct ovsrec_interface *cfg = iface->cfg;
      const char *opstate_str;
      const char *cfm_ccm_vlan;
      struct cfm_settings s;
      struct smap netdev_args;
  
      if (!cfg->n_cfm_mpid) {
          ofproto_port_clear_cfm(iface->port->bridge->ofproto, iface->ofp_port);
          return;
      }
  
      s.check_tnl_key = false;
      smap_init(&netdev_args);
      if (!netdev_get_config(iface->netdev, &netdev_args)) {
          const char *key = smap_get(&netdev_args, "key");
          const char *in_key = smap_get(&netdev_args, "in_key");
  
          s.check_tnl_key = (key && !strcmp(key, "flow"))
                             || (in_key && !strcmp(in_key, "flow"));
      }
      smap_destroy(&netdev_args);
  
      s.mpid = *cfg->cfm_mpid;
      s.interval = smap_get_int(&iface->cfg->other_config, "cfm_interval", 0);
      cfm_ccm_vlan = smap_get(&iface->cfg->other_config, "cfm_ccm_vlan");
      s.ccm_pcp = smap_get_int(&iface->cfg->other_config, "cfm_ccm_pcp", 0);
  
      if (s.interval <= 0) {
          s.interval = 1000;
      }
  
      if (!cfm_ccm_vlan) {
          s.ccm_vlan = 0;
      } else if (!strcasecmp("random", cfm_ccm_vlan)) {
          s.ccm_vlan = CFM_RANDOM_VLAN;
      } else {
          s.ccm_vlan = atoi(cfm_ccm_vlan);
          if (s.ccm_vlan == CFM_RANDOM_VLAN) {
              s.ccm_vlan = 0;
          }
      }
  
      s.extended = smap_get_bool(&iface->cfg->other_config, "cfm_extended",
                                 false);
  
      opstate_str = smap_get(&iface->cfg->other_config, "cfm_opstate");
      s.opup = !opstate_str || !strcasecmp("up", opstate_str);
  
      ofproto_port_set_cfm(iface->port->bridge->ofproto, iface->ofp_port, &s);
  }
  
  /* Returns true if 'iface' is synthetic, that is, if we constructed it locally
   * instead of obtaining it from the database. */
  static bool
  iface_is_synthetic(const struct iface *iface)
  {
      return ovsdb_idl_row_is_synthetic(&iface->cfg->header_);
  }
  
  
  /* Port mirroring. */
  
  static struct mirror *
  mirror_find_by_uuid(struct bridge *br, const struct uuid *uuid)
  {
      struct mirror *m;
  
      HMAP_FOR_EACH_IN_BUCKET (m, hmap_node, uuid_hash(uuid), &br->mirrors) {
          if (uuid_equals(uuid, &m->uuid)) {
              return m;
          }
      }
      return NULL;
  }
  
  static void
  bridge_configure_mirrors(struct bridge *br)
  {
      const struct ovsdb_datum *mc;
      unsigned long *flood_vlans;
      struct mirror *m, *next;
      size_t i;
  
      /* Get rid of deleted mirrors. */
      mc = ovsrec_bridge_get_mirrors(br->cfg, OVSDB_TYPE_UUID);
      HMAP_FOR_EACH_SAFE (m, next, hmap_node, &br->mirrors) {
          union ovsdb_atom atom;
  
          atom.uuid = m->uuid;
          if (ovsdb_datum_find_key(mc, &atom, OVSDB_TYPE_UUID) == UINT_MAX) {
              mirror_destroy(m);
          }
      }
  
      /* Add new mirrors and reconfigure existing ones. */
      for (i = 0; i < br->cfg->n_mirrors; i++) {
          const struct ovsrec_mirror *cfg = br->cfg->mirrors[i];
          struct mirror *m = mirror_find_by_uuid(br, &cfg->header_.uuid);
          if (!m) {
              m = mirror_create(br, cfg);
          }
          m->cfg = cfg;
          if (!mirror_configure(m)) {
              mirror_destroy(m);
          }
      }
  
      /* Update flooded vlans (for RSPAN). */
      flood_vlans = vlan_bitmap_from_array(br->cfg->flood_vlans,
                                           br->cfg->n_flood_vlans);
      ofproto_set_flood_vlans(br->ofproto, flood_vlans);
      bitmap_free(flood_vlans);
  }
  
  static struct mirror *
  mirror_create(struct bridge *br, const struct ovsrec_mirror *cfg)
  {
      struct mirror *m;
  
      m = xzalloc(sizeof *m);
      m->uuid = cfg->header_.uuid;
      hmap_insert(&br->mirrors, &m->hmap_node, uuid_hash(&m->uuid));
      m->bridge = br;
      m->name = xstrdup(cfg->name);
  
      return m;
  }
  
  static void
  mirror_destroy(struct mirror *m)
  {
      if (m) {
          struct bridge *br = m->bridge;
  
          if (br->ofproto) {
              ofproto_mirror_unregister(br->ofproto, m);
          }
  
          hmap_remove(&br->mirrors, &m->hmap_node);
          free(m->name);
          free(m);
      }
  }
  
  static void
  mirror_collect_ports(struct mirror *m,
                       struct ovsrec_port **in_ports, int n_in_ports,
                       void ***out_portsp, size_t *n_out_portsp)
  {
      void **out_ports = xmalloc(n_in_ports * sizeof *out_ports);
      size_t n_out_ports = 0;
      size_t i;
  
      for (i = 0; i < n_in_ports; i++) {
          const char *name = in_ports[i]->name;
          struct port *port = port_lookup(m->bridge, name);
          if (port) {
              out_ports[n_out_ports++] = port;
          } else {
              VLOG_WARN("bridge %s: mirror %s cannot match on nonexistent "
                        "port %s", m->bridge->name, m->name, name);
          }
      }
      *out_portsp = out_ports;
      *n_out_portsp = n_out_ports;
  }
  
  static bool
  mirror_configure(struct mirror *m)
  {
      const struct ovsrec_mirror *cfg = m->cfg;
      struct ofproto_mirror_settings s;
  
      /* Set name. */
      if (strcmp(cfg->name, m->name)) {
          free(m->name);
          m->name = xstrdup(cfg->name);
      }
      s.name = m->name;
  
      /* Get output port or VLAN. */
      if (cfg->output_port) {
          s.out_bundle = port_lookup(m->bridge, cfg->output_port->name);
          if (!s.out_bundle) {
              VLOG_ERR("bridge %s: mirror %s outputs to port not on bridge",
                       m->bridge->name, m->name);
              return false;
          }
          s.out_vlan = UINT16_MAX;
  
          if (cfg->output_vlan) {
              VLOG_ERR("bridge %s: mirror %s specifies both output port and "
                       "output vlan; ignoring output vlan",
                       m->bridge->name, m->name);
          }
      } else if (cfg->output_vlan) {
          /* The database should prevent invalid VLAN values. */
          s.out_bundle = NULL;
          s.out_vlan = *cfg->output_vlan;
      } else {
          VLOG_ERR("bridge %s: mirror %s does not specify output; ignoring",
                   m->bridge->name, m->name);
          return false;
      }
  
      /* Get port selection. */
      if (cfg->select_all) {
          size_t n_ports = hmap_count(&m->bridge->ports);
          void **ports = xmalloc(n_ports * sizeof *ports);
          struct port *port;
          size_t i;
  
          i = 0;
          HMAP_FOR_EACH (port, hmap_node, &m->bridge->ports) {
              ports[i++] = port;
          }
  
          s.srcs = ports;
          s.n_srcs = n_ports;
  
          s.dsts = ports;
          s.n_dsts = n_ports;
      } else {
          /* Get ports, dropping ports that don't exist.
           * The IDL ensures that there are no duplicates. */
          mirror_collect_ports(m, cfg->select_src_port, cfg->n_select_src_port,
                               &s.srcs, &s.n_srcs);
          mirror_collect_ports(m, cfg->select_dst_port, cfg->n_select_dst_port,
                               &s.dsts, &s.n_dsts);
      }
  
      /* Get VLAN selection. */
      s.src_vlans = vlan_bitmap_from_array(cfg->select_vlan, cfg->n_select_vlan);
  
      /* Configure. */
      ofproto_mirror_register(m->bridge->ofproto, m, &s);
  
      /* Clean up. */
      if (s.srcs != s.dsts) {
          free(s.dsts);
      }
      free(s.srcs);
      free(s.src_vlans);
  
      return true;
  }
  
  /* Linux VLAN device support (e.g. "eth0.10" for VLAN 10.)
   *
   * This is deprecated.  It is only for compatibility with broken device drivers
   * in old versions of Linux that do not properly support VLANs when VLAN
   * devices are not used.  When broken device drivers are no longer in
   * widespread use, we will delete these interfaces. */
  
  static struct ovsrec_port **recs;
  static size_t n_recs, allocated_recs;
  
  /* Adds 'rec' to a list of recs that have to be destroyed when the VLAN
   * splinters are reconfigured. */
  static void
  register_rec(struct ovsrec_port *rec)
  {
      if (n_recs >= allocated_recs) {
          recs = x2nrealloc(recs, &allocated_recs, sizeof *recs);
      }
      recs[n_recs++] = rec;
  }
  
  /* Frees all of the ports registered with register_reg(). */
  static void
  free_registered_recs(void)
  {
      size_t i;
  
      for (i = 0; i < n_recs; i++) {
          struct ovsrec_port *port = recs[i];
          size_t j;
  
          for (j = 0; j < port->n_interfaces; j++) {
              struct ovsrec_interface *iface = port->interfaces[j];
              free(iface->name);
              free(iface);
          }
  
          smap_destroy(&port->other_config);
          free(port->interfaces);
          free(port->name);
          free(port->tag);
          free(port);
      }
      n_recs = 0;
  }
  
  /* Returns true if VLAN splinters are enabled on 'iface_cfg', false
   * otherwise. */
  static bool
  vlan_splinters_is_enabled(const struct ovsrec_interface *iface_cfg)
  {
      return smap_get_bool(&iface_cfg->other_config, "enable-vlan-splinters",
                           false);
  }
  
  /* Figures out the set of VLANs that are in use for the purpose of VLAN
   * splinters.
   *
   * If VLAN splinters are enabled on at least one interface and any VLANs are in
   * use, returns a 4096-bit bitmap with a 1-bit for each in-use VLAN (bits 0 and
   * 4095 will not be set).  The caller is responsible for freeing the bitmap,
   * with free().
   *
   * If VLANs splinters are not enabled on any interface or if no VLANs are in
   * use, returns NULL.
   *
   * Updates 'vlan_splinters_enabled_anywhere'. */
  static unsigned long int *
  collect_splinter_vlans(const struct ovsrec_open_vswitch *ovs_cfg)
  {
      unsigned long int *splinter_vlans;
      struct sset splinter_ifaces;
      const char *real_dev_name;
      struct shash *real_devs;
      struct shash_node *node;
      struct bridge *br;
      size_t i;
  
      /* Free space allocated for synthesized ports and interfaces, since we're
       * in the process of reconstructing all of them. */
      free_registered_recs();
  
      splinter_vlans = bitmap_allocate(4096);
      sset_init(&splinter_ifaces);
      vlan_splinters_enabled_anywhere = false;
      for (i = 0; i < ovs_cfg->n_bridges; i++) {
          struct ovsrec_bridge *br_cfg = ovs_cfg->bridges[i];
          size_t j;
  
          for (j = 0; j < br_cfg->n_ports; j++) {
              struct ovsrec_port *port_cfg = br_cfg->ports[j];
              int k;
  
              for (k = 0; k < port_cfg->n_interfaces; k++) {
                  struct ovsrec_interface *iface_cfg = port_cfg->interfaces[k];
  
                  if (vlan_splinters_is_enabled(iface_cfg)) {
                      vlan_splinters_enabled_anywhere = true;
                      sset_add(&splinter_ifaces, iface_cfg->name);
                      vlan_bitmap_from_array__(port_cfg->trunks,
                                               port_cfg->n_trunks,
                                               splinter_vlans);
                  }
              }
  
              if (port_cfg->tag && *port_cfg->tag > 0 && *port_cfg->tag < 4095) {
                  bitmap_set1(splinter_vlans, *port_cfg->tag);
              }
          }
      }
  
      if (!vlan_splinters_enabled_anywhere) {
          free(splinter_vlans);
          sset_destroy(&splinter_ifaces);
          return NULL;
      }
  
      HMAP_FOR_EACH (br, node, &all_bridges) {
          if (br->ofproto) {
              ofproto_get_vlan_usage(br->ofproto, splinter_vlans);
          }
      }
  
      /* Don't allow VLANs 0 or 4095 to be splintered.  VLAN 0 should appear on
       * the real device.  VLAN 4095 is reserved and Linux doesn't allow a VLAN
       * device to be created for it. */
      bitmap_set0(splinter_vlans, 0);
      bitmap_set0(splinter_vlans, 4095);
  
      /* Delete all VLAN devices that we don't need. */
      vlandev_refresh();
      real_devs = vlandev_get_real_devs();
      SHASH_FOR_EACH (node, real_devs) {
          const struct vlan_real_dev *real_dev = node->data;
          const struct vlan_dev *vlan_dev;
          bool real_dev_has_splinters;
  
          real_dev_has_splinters = sset_contains(&splinter_ifaces,
                                                 real_dev->name);
          HMAP_FOR_EACH (vlan_dev, hmap_node, &real_dev->vlan_devs) {
              if (!real_dev_has_splinters
                  || !bitmap_is_set(splinter_vlans, vlan_dev->vid)) {
                  struct netdev *netdev;
  
                  if (!netdev_open(vlan_dev->name, "system", &netdev)) {
                      if (!netdev_get_in4(netdev, NULL, NULL) ||
                          !netdev_get_in6(netdev, NULL)) {
                          /* It has an IP address configured, so we don't own
                           * it.  Don't delete it. */
                      } else {
                          vlandev_del(vlan_dev->name);
                      }
                      netdev_close(netdev);
                  }
              }
  
          }
      }
  
      /* Add all VLAN devices that we need. */
      SSET_FOR_EACH (real_dev_name, &splinter_ifaces) {
          int vid;
  
          BITMAP_FOR_EACH_1 (vid, 4096, splinter_vlans) {
              if (!vlandev_get_name(real_dev_name, vid)) {
                  vlandev_add(real_dev_name, vid);
              }
          }
      }
  
      vlandev_refresh();
  
      sset_destroy(&splinter_ifaces);
  
      if (bitmap_scan(splinter_vlans, 0, 4096) >= 4096) {
          free(splinter_vlans);
          return NULL;
      }
      return splinter_vlans;
  }
  
  /* Pushes the configure of VLAN splinter port 'port' (e.g. eth0.9) down to
   * ofproto.  */
  static void
  configure_splinter_port(struct port *port)
  {
      struct ofproto *ofproto = port->bridge->ofproto;
      uint16_t realdev_ofp_port;
      const char *realdev_name;
      struct iface *vlandev, *realdev;
  
      ofproto_bundle_unregister(port->bridge->ofproto, port);
  
      vlandev = CONTAINER_OF(list_front(&port->ifaces), struct iface,
                             port_elem);
  
      realdev_name = smap_get(&port->cfg->other_config, "realdev");
      realdev = iface_lookup(port->bridge, realdev_name);
      realdev_ofp_port = realdev ? realdev->ofp_port : 0;
  
      ofproto_port_set_realdev(ofproto, vlandev->ofp_port, realdev_ofp_port,
                               *port->cfg->tag);
  }
  
  static struct ovsrec_port *
  synthesize_splinter_port(const char *real_dev_name,
                           const char *vlan_dev_name, int vid)
  {
      struct ovsrec_interface *iface;
      struct ovsrec_port *port;
  
      iface = xmalloc(sizeof *iface);
      ovsrec_interface_init(iface);
      iface->name = xstrdup(vlan_dev_name);
      iface->type = "system";
  
      port = xmalloc(sizeof *port);
      ovsrec_port_init(port);
      port->interfaces = xmemdup(&iface, sizeof iface);
      port->n_interfaces = 1;
      port->name = xstrdup(vlan_dev_name);
      port->vlan_mode = "splinter";
      port->tag = xmalloc(sizeof *port->tag);
      *port->tag = vid;
  
      smap_add(&port->other_config, "realdev", real_dev_name);
  
      register_rec(port);
      return port;
  }
  
  /* For each interface with 'br' that has VLAN splinters enabled, adds a
   * corresponding ovsrec_port to 'ports' for each splinter VLAN marked with a
   * 1-bit in the 'splinter_vlans' bitmap. */
  static void
  add_vlan_splinter_ports(struct bridge *br,
                          const unsigned long int *splinter_vlans,
                          struct shash *ports)
  {
      size_t i;
  
      /* We iterate through 'br->cfg->ports' instead of 'ports' here because
       * we're modifying 'ports'. */
      for (i = 0; i < br->cfg->n_ports; i++) {
          const char *name = br->cfg->ports[i]->name;
          struct ovsrec_port *port_cfg = shash_find_data(ports, name);
          size_t j;
  
          for (j = 0; j < port_cfg->n_interfaces; j++) {
              struct ovsrec_interface *iface_cfg = port_cfg->interfaces[j];
  
              if (vlan_splinters_is_enabled(iface_cfg)) {
                  const char *real_dev_name;
                  uint16_t vid;
  
                  real_dev_name = iface_cfg->name;
                  BITMAP_FOR_EACH_1 (vid, 4096, splinter_vlans) {
                      const char *vlan_dev_name;
  
                      vlan_dev_name = vlandev_get_name(real_dev_name, vid);
                      if (vlan_dev_name
                          && !shash_find(ports, vlan_dev_name)) {
                          shash_add(ports, vlan_dev_name,
                                    synthesize_splinter_port(
                                        real_dev_name, vlan_dev_name, vid));
                      }
                  }
              }
          }
      }
  }
  
  static void
  mirror_refresh_stats(struct mirror *m)
  {
      struct ofproto *ofproto = m->bridge->ofproto;
      uint64_t tx_packets, tx_bytes;
      char *keys[2];
      int64_t values[2];
      size_t stat_cnt = 0;
  
      if (ofproto_mirror_get_stats(ofproto, m, &tx_packets, &tx_bytes)) {
          ovsrec_mirror_set_statistics(m->cfg, NULL, NULL, 0);
          return;
      }
  
      if (tx_packets != UINT64_MAX) {
          keys[stat_cnt] = "tx_packets";
          values[stat_cnt] = tx_packets;
          stat_cnt++;
      }
      if (tx_bytes != UINT64_MAX) {
          keys[stat_cnt] = "tx_bytes";
          values[stat_cnt] = tx_bytes;
          stat_cnt++;
      }
  
      ovsrec_mirror_set_statistics(m->cfg, keys, values, stat_cnt);
  }
  