text: /*
   * Copyright (c) 2009, 2010, 2011 Nicira Networks.
   * Copyright (c) 2009 InMon Corp.
   *
   * 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 "ofproto-dpif-sflow.h"
  #include <inttypes.h>
  #include <stdlib.h>
  #include "collectors.h"
  #include "compiler.h"
  #include "dpif.h"
  #include "hash.h"
  #include "hmap.h"
  #include "netdev.h"
  #include "netlink.h"
  #include "ofpbuf.h"
  #include "ofproto.h"
  #include "packets.h"
  #include "poll-loop.h"
  #include "sflow_api.h"
  #include "socket-util.h"
  #include "timeval.h"
  #include "vlog.h"
  #include "lib/odp-util.h"
  
  VLOG_DEFINE_THIS_MODULE(sflow);
  
  struct dpif_sflow_port {
      struct hmap_node hmap_node; /* In struct dpif_sflow's "ports" hmap. */
      struct netdev *netdev;      /* Underlying network device, for stats. */
      SFLDataSource_instance dsi; /* sFlow library's notion of port number. */
      uint16_t odp_port;          /* Datapath port number. */
  };
  
  struct dpif_sflow {
      struct collectors *collectors;
      SFLAgent *sflow_agent;
      struct ofproto_sflow_options *options;
      struct dpif *dpif;
      time_t next_tick;
      size_t n_flood, n_all;
      struct hmap ports;          /* Contains "struct dpif_sflow_port"s. */
      uint32_t probability;
  };
  
  static void dpif_sflow_del_port__(struct dpif_sflow *,
                                    struct dpif_sflow_port *);
  
  #define RECEIVER_INDEX 1
  
  static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
  
  static bool
  nullable_string_is_equal(const char *a, const char *b)
  {
      return a ? b && !strcmp(a, b) : !b;
  }
  
  static bool
  ofproto_sflow_options_equal(const struct ofproto_sflow_options *a,
                           const struct ofproto_sflow_options *b)
  {
      return (sset_equals(&a->targets, &b->targets)
              && a->sampling_rate == b->sampling_rate
              && a->polling_interval == b->polling_interval
              && a->header_len == b->header_len
              && a->sub_id == b->sub_id
              && nullable_string_is_equal(a->agent_device, b->agent_device)
              && nullable_string_is_equal(a->control_ip, b->control_ip));
  }
  
  static struct ofproto_sflow_options *
  ofproto_sflow_options_clone(const struct ofproto_sflow_options *old)
  {
      struct ofproto_sflow_options *new = xmemdup(old, sizeof *old);
      sset_clone(&new->targets, &old->targets);
      new->agent_device = old->agent_device ? xstrdup(old->agent_device) : NULL;
      new->control_ip = old->control_ip ? xstrdup(old->control_ip) : NULL;
      return new;
  }
  
  static void
  ofproto_sflow_options_destroy(struct ofproto_sflow_options *options)
  {
      if (options) {
          sset_destroy(&options->targets);
          free(options->agent_device);
          free(options->control_ip);
          free(options);
      }
  }
  
  /* sFlow library callback to allocate memory. */
  static void *
  sflow_agent_alloc_cb(void *magic OVS_UNUSED, SFLAgent *agent OVS_UNUSED,
                       size_t bytes)
  {
      return calloc(1, bytes);
  }
  
  /* sFlow library callback to free memory. */
  static int
  sflow_agent_free_cb(void *magic OVS_UNUSED, SFLAgent *agent OVS_UNUSED,
                      void *obj)
  {
      free(obj);
      return 0;
  }
  
  /* sFlow library callback to report error. */
  static void
  sflow_agent_error_cb(void *magic OVS_UNUSED, SFLAgent *agent OVS_UNUSED,
                       char *msg)
  {
      VLOG_WARN("sFlow agent error: %s", msg);
  }
  
  /* sFlow library callback to send datagram. */
  static void
  sflow_agent_send_packet_cb(void *ds_, SFLAgent *agent OVS_UNUSED,
                             SFLReceiver *receiver OVS_UNUSED, u_char *pkt,
                             uint32_t pktLen)
  {
      struct dpif_sflow *ds = ds_;
      collectors_send(ds->collectors, pkt, pktLen);
  }
  
  static struct dpif_sflow_port *
  dpif_sflow_find_port(const struct dpif_sflow *ds, uint16_t odp_port)
  {
      struct dpif_sflow_port *dsp;
  
      HMAP_FOR_EACH_IN_BUCKET (dsp, hmap_node,
                               hash_int(odp_port, 0), &ds->ports) {
          if (dsp->odp_port == odp_port) {
              return dsp;
          }
      }
      return NULL;
  }
  
  static void
  sflow_agent_get_counters(void *ds_, SFLPoller *poller,
                           SFL_COUNTERS_SAMPLE_TYPE *cs)
  {
      struct dpif_sflow *ds = ds_;
      SFLCounters_sample_element elem;
      struct dpif_sflow_port *dsp;
      SFLIf_counters *counters;
      struct netdev_stats stats;
      enum netdev_flags flags;
      uint32_t current;
  
      dsp = dpif_sflow_find_port(ds, poller->bridgePort);
      if (!dsp) {
          return;
      }
  
      elem.tag = SFLCOUNTERS_GENERIC;
      counters = &elem.counterBlock.generic;
      counters->ifIndex = SFL_DS_INDEX(poller->dsi);
      counters->ifType = 6;
      if (!netdev_get_features(dsp->netdev, &current, NULL, NULL, NULL)) {
          /* The values of ifDirection come from MAU MIB (RFC 2668): 0 = unknown,
             1 = full-duplex, 2 = half-duplex, 3 = in, 4=out */
          counters->ifSpeed = netdev_features_to_bps(current);
          counters->ifDirection = (netdev_features_is_full_duplex(current)
                                   ? 1 : 2);
      } else {
          counters->ifSpeed = 100000000;
          counters->ifDirection = 0;
      }
      if (!netdev_get_flags(dsp->netdev, &flags) && flags & NETDEV_UP) {
          counters->ifStatus = 1; /* ifAdminStatus up. */
          if (netdev_get_carrier(dsp->netdev)) {
              counters->ifStatus |= 2; /* ifOperStatus us. */
          }
      } else {
          counters->ifStatus = 0;  /* Down. */
      }
  
      /* XXX
         1. Is the multicast counter filled in?
         2. Does the multicast counter include broadcasts?
         3. Does the rx_packets counter include multicasts/broadcasts?
      */
      netdev_get_stats(dsp->netdev, &stats);
      counters->ifInOctets = stats.rx_bytes;
      counters->ifInUcastPkts = stats.rx_packets;
      counters->ifInMulticastPkts = stats.multicast;
      counters->ifInBroadcastPkts = -1;
      counters->ifInDiscards = stats.rx_dropped;
      counters->ifInErrors = stats.rx_errors;
      counters->ifInUnknownProtos = -1;
      counters->ifOutOctets = stats.tx_bytes;
      counters->ifOutUcastPkts = stats.tx_packets;
      counters->ifOutMulticastPkts = -1;
      counters->ifOutBroadcastPkts = -1;
      counters->ifOutDiscards = stats.tx_dropped;
      counters->ifOutErrors = stats.tx_errors;
      counters->ifPromiscuousMode = 0;
  
      SFLADD_ELEMENT(cs, &elem);
      sfl_poller_writeCountersSample(poller, cs);
  }
  
  /* Obtains an address to use for the local sFlow agent and stores it into
   * '*agent_addr'.  Returns true if successful, false on failure.
   *
   * The sFlow agent address should be a local IP address that is persistent and
   * reachable over the network, if possible.  The IP address associated with
   * 'agent_device' is used if it has one, and otherwise 'control_ip', the IP
   * address used to talk to the controller. */
  static bool
  sflow_choose_agent_address(const char *agent_device, const char *control_ip,
                             SFLAddress *agent_addr)
  {
      struct in_addr in4;
  
      memset(agent_addr, 0, sizeof *agent_addr);
      agent_addr->type = SFLADDRESSTYPE_IP_V4;
  
      if (agent_device) {
          struct netdev *netdev;
  
          if (!netdev_open(agent_device, "system", &netdev)) {
              int error = netdev_get_in4(netdev, &in4, NULL);
              netdev_close(netdev);
              if (!error) {
                  goto success;
              }
          }
      }
  
      if (control_ip && !lookup_ip(control_ip, &in4)) {
          goto success;
      }
  
      VLOG_ERR("could not determine IP address for sFlow agent");
      return false;
  
  success:
      agent_addr->address.ip_v4.addr = (OVS_FORCE uint32_t) in4.s_addr;
      return true;
  }
  
  void
  dpif_sflow_clear(struct dpif_sflow *ds)
  {
      if (ds->sflow_agent) {
          sfl_agent_release(ds->sflow_agent);
          ds->sflow_agent = NULL;
      }
      collectors_destroy(ds->collectors);
      ds->collectors = NULL;
      ofproto_sflow_options_destroy(ds->options);
      ds->options = NULL;
  
      /* Turn off sampling to save CPU cycles. */
      ds->probability = 0;
  }
  
  bool
  dpif_sflow_is_enabled(const struct dpif_sflow *ds)
  {
      return ds->collectors != NULL;
  }
  
  struct dpif_sflow *
  dpif_sflow_create(struct dpif *dpif)
  {
      struct dpif_sflow *ds;
  
      ds = xcalloc(1, sizeof *ds);
      ds->dpif = dpif;
      ds->next_tick = time_now() + 1;
      hmap_init(&ds->ports);
      ds->probability = 0;
      return ds;
  }
  
  /* 32-bit fraction of packets to sample with.  A value of 0 samples no packets,
   * a value of %UINT32_MAX samples all packets and intermediate values sample
   * intermediate fractions of packets. */
  uint32_t
  dpif_sflow_get_probability(const struct dpif_sflow *ds)
  {
      return ds->probability;
  }
  
  void
  dpif_sflow_destroy(struct dpif_sflow *ds)
  {
      if (ds) {
          struct dpif_sflow_port *dsp, *next;
  
          dpif_sflow_clear(ds);
          HMAP_FOR_EACH_SAFE (dsp, next, hmap_node, &ds->ports) {
              dpif_sflow_del_port__(ds, dsp);
          }
          hmap_destroy(&ds->ports);
          free(ds);
      }
  }
  
  static void
  dpif_sflow_add_poller(struct dpif_sflow *ds,
                        struct dpif_sflow_port *dsp, uint16_t odp_port)
  {
      SFLPoller *poller = sfl_agent_addPoller(ds->sflow_agent, &dsp->dsi, ds,
                                              sflow_agent_get_counters);
      sfl_poller_set_sFlowCpInterval(poller, ds->options->polling_interval);
      sfl_poller_set_sFlowCpReceiver(poller, RECEIVER_INDEX);
      sfl_poller_set_bridgePort(poller, odp_port);
  }
  
  static void
  dpif_sflow_add_sampler(struct dpif_sflow *ds, struct dpif_sflow_port *dsp)
  {
      SFLSampler *sampler = sfl_agent_addSampler(ds->sflow_agent, &dsp->dsi);
      sfl_sampler_set_sFlowFsPacketSamplingRate(sampler, ds->options->sampling_rate);
      sfl_sampler_set_sFlowFsMaximumHeaderSize(sampler, ds->options->header_len);
      sfl_sampler_set_sFlowFsReceiver(sampler, RECEIVER_INDEX);
  }
  
  void
  dpif_sflow_add_port(struct dpif_sflow *ds, uint16_t odp_port,
                      const char *netdev_name)
  {
      struct dpif_sflow_port *dsp;
      struct netdev *netdev;
      uint32_t ifindex;
      int error;
  
      dpif_sflow_del_port(ds, odp_port);
  
      /* Open network device. */
      error = netdev_open(netdev_name, "system", &netdev);
      if (error) {
          VLOG_WARN_RL(&rl, "failed to open network device \"%s\": %s",
                       netdev_name, strerror(error));
          return;
      }
  
      /* Add to table of ports. */
      dsp = xmalloc(sizeof *dsp);
      dsp->netdev = netdev;
      ifindex = netdev_get_ifindex(netdev);
      if (ifindex <= 0) {
          ifindex = (ds->sflow_agent->subId << 16) + odp_port;
      }
      SFL_DS_SET(dsp->dsi, 0, ifindex, 0);
      dsp->odp_port = odp_port;
      hmap_insert(&ds->ports, &dsp->hmap_node, hash_int(odp_port, 0));
  
      /* Add poller and sampler. */
      if (ds->sflow_agent) {
          dpif_sflow_add_poller(ds, dsp, odp_port);
          dpif_sflow_add_sampler(ds, dsp);
      }
  }
  
  static void
  dpif_sflow_del_port__(struct dpif_sflow *ds, struct dpif_sflow_port *dsp)
  {
      if (ds->sflow_agent) {
          sfl_agent_removePoller(ds->sflow_agent, &dsp->dsi);
          sfl_agent_removeSampler(ds->sflow_agent, &dsp->dsi);
      }
      netdev_close(dsp->netdev);
      hmap_remove(&ds->ports, &dsp->hmap_node);
      free(dsp);
  }
  
  void
  dpif_sflow_del_port(struct dpif_sflow *ds, uint16_t odp_port)
  {
      struct dpif_sflow_port *dsp = dpif_sflow_find_port(ds, odp_port);
      if (dsp) {
          dpif_sflow_del_port__(ds, dsp);
      }
  }
  
  void
  dpif_sflow_set_options(struct dpif_sflow *ds,
                         const struct ofproto_sflow_options *options)
  {
      struct dpif_sflow_port *dsp;
      bool options_changed;
      SFLReceiver *receiver;
      SFLAddress agentIP;
      time_t now;
  
      if (sset_is_empty(&options->targets) || !options->sampling_rate) {
          /* No point in doing any work if there are no targets or nothing to
           * sample. */
          dpif_sflow_clear(ds);
          return;
      }
  
      options_changed = (!ds->options
                         || !ofproto_sflow_options_equal(options, ds->options));
  
      /* Configure collectors if options have changed or if we're shortchanged in
       * collectors (which indicates that opening one or more of the configured
       * collectors failed, so that we should retry). */
      if (options_changed
          || collectors_count(ds->collectors) < sset_count(&options->targets)) {
          collectors_destroy(ds->collectors);
          collectors_create(&options->targets, SFL_DEFAULT_COLLECTOR_PORT,
                            &ds->collectors);
          if (ds->collectors == NULL) {
              VLOG_WARN_RL(&rl, "no collectors could be initialized, "
                           "sFlow disabled");
              dpif_sflow_clear(ds);
              return;
          }
      }
  
      /* Avoid reconfiguring if options didn't change. */
      if (!options_changed) {
          return;
      }
      ofproto_sflow_options_destroy(ds->options);
      ds->options = ofproto_sflow_options_clone(options);
  
      /* Choose agent IP address. */
      if (!sflow_choose_agent_address(options->agent_device,
                                      options->control_ip, &agentIP)) {
          dpif_sflow_clear(ds);
          return;
      }
  
      /* Create agent. */
      VLOG_INFO("creating sFlow agent %d", options->sub_id);
      if (ds->sflow_agent) {
          sfl_agent_release(ds->sflow_agent);
      }
      ds->sflow_agent = xcalloc(1, sizeof *ds->sflow_agent);
      now = time_wall();
      sfl_agent_init(ds->sflow_agent,
                     &agentIP,
                     options->sub_id,
                     now,         /* Boot time. */
                     now,         /* Current time. */
                     ds,          /* Pointer supplied to callbacks. */
                     sflow_agent_alloc_cb,
                     sflow_agent_free_cb,
                     sflow_agent_error_cb,
                     sflow_agent_send_packet_cb);
  
      receiver = sfl_agent_addReceiver(ds->sflow_agent);
      sfl_receiver_set_sFlowRcvrOwner(receiver, "Open vSwitch sFlow");
      sfl_receiver_set_sFlowRcvrTimeout(receiver, 0xffffffff);
  
      /* Set the sampling_rate down in the datapath. */
      ds->probability = MAX(1, UINT32_MAX / ds->options->sampling_rate);
  
      /* Add samplers and pollers for the currently known ports. */
      HMAP_FOR_EACH (dsp, hmap_node, &ds->ports) {
          dpif_sflow_add_poller(ds, dsp, dsp->odp_port);
          dpif_sflow_add_sampler(ds, dsp);
      }
  }
  
  int
  dpif_sflow_odp_port_to_ifindex(const struct dpif_sflow *ds,
                                 uint16_t odp_port)
  {
      struct dpif_sflow_port *dsp = dpif_sflow_find_port(ds, odp_port);
      return dsp ? SFL_DS_INDEX(dsp->dsi) : 0;
  }
  
  void
  dpif_sflow_received(struct dpif_sflow *ds, struct ofpbuf *packet,
                      const struct flow *flow,
                      const struct user_action_cookie *cookie)
  {
      SFL_FLOW_SAMPLE_TYPE fs;
      SFLFlow_sample_element hdrElem;
      SFLSampled_header *header;
      SFLFlow_sample_element switchElem;
      SFLSampler *sampler;
      struct dpif_sflow_port *in_dsp;
      struct netdev_stats stats;
      int error;
  
      /* Build a flow sample */
      memset(&fs, 0, sizeof fs);
  
      in_dsp = dpif_sflow_find_port(ds, ofp_port_to_odp_port(flow->in_port));
      if (!in_dsp) {
          return;
      }
      fs.input = SFL_DS_INDEX(in_dsp->dsi);
  
      error = netdev_get_stats(in_dsp->netdev, &stats);
      if (error) {
          VLOG_WARN_RL(&rl, "netdev get-stats error %s", strerror(error));
          return;
      }
      fs.sample_pool = stats.rx_packets;
  
      /* We are going to give it to the sampler that represents this input port.
       * By implementing "ingress-only" sampling like this we ensure that we
       * never have to offer the same sample to more than one sampler. */
      sampler = sfl_agent_getSamplerByIfIndex(ds->sflow_agent, fs.input);
      if (!sampler) {
          VLOG_WARN_RL(&rl, "no sampler for input ifIndex (%"PRIu32")",
                       fs.input);
          return;
      }
  
      /* Sampled header. */
      memset(&hdrElem, 0, sizeof hdrElem);
      hdrElem.tag = SFLFLOW_HEADER;
      header = &hdrElem.flowType.header;
      header->header_protocol = SFLHEADER_ETHERNET_ISO8023;
      /* The frame_length should include the Ethernet FCS (4 bytes),
         but it has already been stripped,  so we need to add 4 here. */
      header->frame_length = packet->size + 4;
      /* Ethernet FCS stripped off. */
      header->stripped = 4;
      header->header_length = MIN(packet->size,
                                  sampler->sFlowFsMaximumHeaderSize);
      header->header_bytes = packet->data;
  
      /* Add extended switch element. */
      memset(&switchElem, 0, sizeof(switchElem));
      switchElem.tag = SFLFLOW_EX_SWITCH;
      switchElem.flowType.sw.src_vlan = vlan_tci_to_vid(flow->vlan_tci);
      switchElem.flowType.sw.src_priority = vlan_tci_to_pcp(flow->vlan_tci);
  
      /* Retrieve data from user_action_cookie. */
      switchElem.flowType.sw.dst_vlan = vlan_tci_to_vid(cookie->vlan_tci);
      switchElem.flowType.sw.dst_priority = vlan_tci_to_pcp(cookie->vlan_tci);
  
      /* Set output port, as defined by http://www.sflow.org/sflow_version_5.txt
         (search for "Input/output port information"). */
      if (!cookie->n_output) {
          /* This value indicates that the packet was dropped for an unknown
           * reason. */
          fs.output = 0x40000000 | 256;
      } else if (cookie->n_output > 1 || !cookie->data) {
          /* Setting the high bit means "multiple output ports". */
          fs.output = 0x80000000 | cookie->n_output;
      } else {
          fs.output = cookie->data;
      }
  
      /* Submit the flow sample to be encoded into the next datagram. */
      SFLADD_ELEMENT(&fs, &hdrElem);
      SFLADD_ELEMENT(&fs, &switchElem);
      sfl_sampler_writeFlowSample(sampler, &fs);
  }
  
  void
  dpif_sflow_run(struct dpif_sflow *ds)
  {
      if (dpif_sflow_is_enabled(ds)) {
          time_t now = time_now();
          if (now >= ds->next_tick) {
              sfl_agent_tick(ds->sflow_agent, time_wall());
              ds->next_tick = now + 1;
          }
      }
  }
  
  void
  dpif_sflow_wait(struct dpif_sflow *ds)
  {
      if (dpif_sflow_is_enabled(ds)) {
          poll_timer_wait_until(ds->next_tick * 1000LL);
      }
  }
  