[ovs-dev,V2] ipfix: Export user specified virtual observation ID

diff --git a/ofproto/ipfix-enterprise-entities.def b/ofproto/ipfix-enterprise-entities.def
index ea94586..73a520c 100644
--- a/ofproto/ipfix-enterprise-entities.def
+++ b/ofproto/ipfix-enterprise-entities.def
@@ -12,5 +12,6 @@  IPFIX_ENTERPRISE_ENTITY(TUNNEL_DESTINATION_IPV4_ADDRESS, 894, 4, tunnelDestinati
 IPFIX_ENTERPRISE_ENTITY(TUNNEL_PROTOCOL_IDENTIFIER, 895, 1, tunnelProtocolIdentifier, IPFIX_ENTERPRISE_VMWARE)
 IPFIX_ENTERPRISE_ENTITY(TUNNEL_SOURCE_TRANSPORT_PORT, 896, 2, tunnelSourceTransportPort, IPFIX_ENTERPRISE_VMWARE)
 IPFIX_ENTERPRISE_ENTITY(TUNNEL_DESTINATION_TRANSPORT_PORT, 897, 2, tunnelDestinationTransportPort, IPFIX_ENTERPRISE_VMWARE)
+IPFIX_ENTERPRISE_ENTITY(VIRTUAL_OBS_ID, 898, 0, virtualObsID, IPFIX_ENTERPRISE_VMWARE)
 
 #undef IPFIX_ENTERPRISE_ENTITY
diff --git a/ofproto/ofproto-dpif-ipfix.c b/ofproto/ofproto-dpif-ipfix.c
index f166014..81cd07c 100644
--- a/ofproto/ofproto-dpif-ipfix.c
+++ b/ofproto/ofproto-dpif-ipfix.c
@@ -101,6 +101,8 @@  struct dpif_ipfix_exporter {
     struct ovs_list cache_flow_start_timestamp_list;  /* ipfix_flow_cache_entry. */
     uint32_t cache_active_timeout;  /* In seconds. */
     uint32_t cache_max_flows;
+    char *virtual_obs_id;
+    uint8_t virtual_obs_len;
 
     ofproto_ipfix_stats stats;
 };
@@ -367,6 +369,32 @@  struct ipfix_data_record_aggregated_ip {
 BUILD_ASSERT_DECL(sizeof(struct ipfix_data_record_aggregated_ip) == 32);
 
 /*
+ * Refer to RFC 7011, the length of Variable length element is 0~65535:
+ * In most case, it should be less than 255 octets:
+ *  0                   1                   2                   3
+ *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  | Length (< 255)|          Information Element                  |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |                      ... continuing as needed                 |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * When it is greater than or equeal to 255 octets:
+ *  0                   1                   2                   3
+ *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |      255      |      Length (0 to 65535)      |       IE      |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |                      ... continuing as needed                 |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ *
+ * Now, only the virtual_obs_id whose length < 255 is implemented.
+ */
+
+#define IPFIX_VIRTUAL_OBS_MAX_LEN 254
+
+/*
  * support tunnel key for:
  * VxLAN: 24-bit VIN,
  * GRE: 32-bit key,
@@ -436,6 +464,12 @@  static void get_export_time_now(uint64_t *, uint32_t *);
 static void dpif_ipfix_cache_expire_now(struct dpif_ipfix_exporter *, bool);
 
 static bool
+nullable_string_is_equal(const char *a, const char *b)
+{
+    return a ? b && !strcmp(a, b) : !b;
+}
+
+static bool
 ofproto_ipfix_bridge_exporter_options_equal(
     const struct ofproto_ipfix_bridge_exporter_options *a,
     const struct ofproto_ipfix_bridge_exporter_options *b)
@@ -448,7 +482,8 @@  ofproto_ipfix_bridge_exporter_options_equal(
             && a->enable_tunnel_sampling == b->enable_tunnel_sampling
             && a->enable_input_sampling == b->enable_input_sampling
             && a->enable_output_sampling == b->enable_output_sampling
-            && sset_equals(&a->targets, &b->targets));
+            && sset_equals(&a->targets, &b->targets)
+            && nullable_string_is_equal(a->virtual_obs_id, b->virtual_obs_id));
 }
 
 static struct ofproto_ipfix_bridge_exporter_options *
@@ -458,6 +493,8 @@  ofproto_ipfix_bridge_exporter_options_clone(
     struct ofproto_ipfix_bridge_exporter_options *new =
         xmemdup(old, sizeof *old);
     sset_clone(&new->targets, &old->targets);
+    new->virtual_obs_id = old->virtual_obs_id ? xstrdup(old->virtual_obs_id)
+                                              : NULL;
     return new;
 }
 
@@ -467,6 +504,7 @@  ofproto_ipfix_bridge_exporter_options_destroy(
 {
     if (options) {
         sset_destroy(&options->targets);
+        free(options->virtual_obs_id);
         free(options);
     }
 }
@@ -480,7 +518,8 @@  ofproto_ipfix_flow_exporter_options_equal(
             && a->cache_active_timeout == b->cache_active_timeout
             && a->cache_max_flows == b->cache_max_flows
             && a->enable_tunnel_sampling == b->enable_tunnel_sampling
-            && sset_equals(&a->targets, &b->targets));
+            && sset_equals(&a->targets, &b->targets)
+            && nullable_string_is_equal(a->virtual_obs_id, b->virtual_obs_id));
 }
 
 static struct ofproto_ipfix_flow_exporter_options *
@@ -490,6 +529,8 @@  ofproto_ipfix_flow_exporter_options_clone(
     struct ofproto_ipfix_flow_exporter_options *new =
         xmemdup(old, sizeof *old);
     sset_clone(&new->targets, &old->targets);
+    new->virtual_obs_id = old->virtual_obs_id ? xstrdup(old->virtual_obs_id)
+                                              : NULL;
     return new;
 }
 
@@ -499,6 +540,7 @@  ofproto_ipfix_flow_exporter_options_destroy(
 {
     if (options) {
         sset_destroy(&options->targets);
+        free(options->virtual_obs_id);
         free(options);
     }
 }
@@ -513,6 +555,8 @@  dpif_ipfix_exporter_init(struct dpif_ipfix_exporter *exporter)
     ovs_list_init(&exporter->cache_flow_start_timestamp_list);
     exporter->cache_active_timeout = 0;
     exporter->cache_max_flows = 0;
+    exporter->virtual_obs_id = NULL;
+    exporter->virtual_obs_len = 0;
 }
 
 static void
@@ -527,6 +571,9 @@  dpif_ipfix_exporter_clear(struct dpif_ipfix_exporter *exporter)
     exporter->last_template_set_time = 0;
     exporter->cache_active_timeout = 0;
     exporter->cache_max_flows = 0;
+    free(exporter->virtual_obs_id);
+    exporter->virtual_obs_id = NULL;
+    exporter->virtual_obs_len = 0;
 }
 
 static void
@@ -540,8 +587,10 @@  static bool
 dpif_ipfix_exporter_set_options(struct dpif_ipfix_exporter *exporter,
                                 const struct sset *targets,
                                 const uint32_t cache_active_timeout,
-                                const uint32_t cache_max_flows)
+                                const uint32_t cache_max_flows,
+                                const char *virtual_obs_id)
 {
+    size_t virtual_obs_len;
     collectors_destroy(exporter->collectors);
     collectors_create(targets, IPFIX_DEFAULT_COLLECTOR_PORT,
                       &exporter->collectors);
@@ -553,6 +602,16 @@  dpif_ipfix_exporter_set_options(struct dpif_ipfix_exporter *exporter,
     }
     exporter->cache_active_timeout = cache_active_timeout;
     exporter->cache_max_flows = cache_max_flows;
+    virtual_obs_len = virtual_obs_id ? strlen(virtual_obs_id) : 0;
+    if (virtual_obs_len > IPFIX_VIRTUAL_OBS_MAX_LEN) {
+        VLOG_WARN_RL(&rl, "Virtual obsevation ID too long(%d bytes), "
+                     "should not be longer than %d bytes.",
+                     exporter->virtual_obs_len, IPFIX_VIRTUAL_OBS_MAX_LEN);
+        dpif_ipfix_exporter_clear(exporter);
+        return false;
+    }
+    exporter->virtual_obs_len = virtual_obs_len;
+    exporter->virtual_obs_id = virtual_obs_id ? xstrdup(virtual_obs_id) : NULL;
     return true;
 }
 
@@ -707,7 +766,8 @@  dpif_ipfix_bridge_exporter_set_options(
             < sset_count(&options->targets)) {
         if (!dpif_ipfix_exporter_set_options(
                 &exporter->exporter, &options->targets,
-                options->cache_active_timeout, options->cache_max_flows)) {
+                options->cache_active_timeout, options->cache_max_flows,
+                options->virtual_obs_id)) {
             return;
         }
     }
@@ -795,7 +855,8 @@  dpif_ipfix_flow_exporter_set_options(
             < sset_count(&options->targets)) {
         if (!dpif_ipfix_exporter_set_options(
                 &exporter->exporter, &options->targets,
-                options->cache_active_timeout, options->cache_max_flows)) {
+                options->cache_active_timeout, options->cache_max_flows,
+                options->virtual_obs_id)) {
             return false;
         }
     }
@@ -1074,6 +1135,7 @@  ipfix_define_template_entity(enum ipfix_entity_id id,
 static uint16_t
 ipfix_define_template_fields(enum ipfix_proto_l2 l2, enum ipfix_proto_l3 l3,
                              enum ipfix_proto_l4 l4, enum ipfix_proto_tunnel tunnel,
+                             bool virtual_obs_id_set,
                              struct dp_packet *msg)
 {
     uint16_t count = 0;
@@ -1145,7 +1207,12 @@  ipfix_define_template_fields(enum ipfix_proto_l2 l2, enum ipfix_proto_l3 l3,
         DEF(TUNNEL_KEY);
     }
 
-    /* 2. Flow aggregated data. */
+    /* 2. virtual obs ID, which is not a part of flow key */
+    if (virtual_obs_id_set) {
+        DEF(VIRTUAL_OBS_ID);
+    }
+
+    /* 3. Flow aggregated data. */
 
     DEF(FLOW_START_DELTA_MICROSECONDS);
     DEF(FLOW_END_DELTA_MICROSECONDS);
@@ -1159,8 +1226,6 @@  ipfix_define_template_fields(enum ipfix_proto_l2 l2, enum ipfix_proto_l3 l3,
         DEF(MINIMUM_IP_TOTAL_LENGTH);
         DEF(MAXIMUM_IP_TOTAL_LENGTH);
     }
-
-
 #undef DEF
 
     return count;
@@ -1254,7 +1319,8 @@  ipfix_send_template_msgs(struct dpif_ipfix_exporter *exporter,
                     tmpl_hdr->template_id = htons(
                         ipfix_get_template_id(l2, l3, l4, tunnel));
                     field_count =
-                        ipfix_define_template_fields(l2, l3, l4, tunnel, &msg);
+                        ipfix_define_template_fields(l2, l3, l4, tunnel,
+                             exporter->virtual_obs_id != NULL, &msg);
                     tmpl_hdr = (struct ipfix_template_record_header*)
                         ((uint8_t*)dp_packet_data(&msg) + tmpl_hdr_offset);
                     tmpl_hdr->field_count = htons(field_count);
@@ -1738,6 +1804,8 @@  static void
 ipfix_put_data_set(uint32_t export_time_sec,
                    struct ipfix_flow_cache_entry *entry,
                    enum ipfix_flow_end_reason flow_end_reason,
+                   const char *virtual_obs_id,
+                   uint8_t virtual_obs_len,
                    struct dp_packet *msg)
 {
     size_t set_hdr_offset;
@@ -1754,6 +1822,12 @@  ipfix_put_data_set(uint32_t export_time_sec,
     dp_packet_put(msg, entry->flow_key.flow_key_msg_part,
                entry->flow_key.flow_key_msg_part_size);
 
+    /* Export virtual obs ID */
+    if (virtual_obs_id) {
+        dp_packet_put(msg, &virtual_obs_len, sizeof(virtual_obs_len));
+        dp_packet_put(msg, virtual_obs_id, virtual_obs_len);
+    }
+
     /* Put the non-key part of the data record. */
 
     {
@@ -1816,7 +1890,9 @@  ipfix_send_data_msg(struct dpif_ipfix_exporter *exporter,
 
     ipfix_init_header(export_time_sec, exporter->seq_number++,
                       entry->flow_key.obs_domain_id, &msg);
-    ipfix_put_data_set(export_time_sec, entry, flow_end_reason, &msg);
+    ipfix_put_data_set(export_time_sec, entry, flow_end_reason,
+                       exporter->virtual_obs_id, exporter->virtual_obs_len,
+                       &msg);
     tx_errors = ipfix_send_msg(exporter->collectors, &msg);
 
     dp_packet_uninit(&msg);
diff --git a/ofproto/ofproto.h b/ofproto/ofproto.h
index 774b5b6..26c687c 100644
--- a/ofproto/ofproto.h
+++ b/ofproto/ofproto.h
@@ -82,6 +82,7 @@  struct ofproto_ipfix_bridge_exporter_options {
     bool enable_tunnel_sampling;
     bool enable_input_sampling;
     bool enable_output_sampling;
+    char *virtual_obs_id;
 };
 
 struct ofproto_ipfix_flow_exporter_options {
@@ -90,6 +91,7 @@  struct ofproto_ipfix_flow_exporter_options {
     uint32_t cache_active_timeout;
     uint32_t cache_max_flows;
     bool enable_tunnel_sampling;
+    char *virtual_obs_id;
 };
 
 struct ofproto_rstp_status {
diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
index 4273552..b4bede0 100644
--- a/vswitchd/bridge.c
+++ b/vswitchd/bridge.c
@@ -1165,6 +1165,7 @@  bridge_configure_ipfix(struct bridge *br)
     struct ofproto_ipfix_bridge_exporter_options be_opts;
     struct ofproto_ipfix_flow_exporter_options *fe_opts = NULL;
     size_t n_fe_opts = 0;
+    const char *virtual_obs_id;
 
     OVSREC_FLOW_SAMPLE_COLLECTOR_SET_FOR_EACH(fe_cfg, idl) {
         if (ovsrec_fscs_is_valid(fe_cfg, br)) {
@@ -1209,6 +1210,10 @@  bridge_configure_ipfix(struct bridge *br)
 
         be_opts.enable_output_sampling = !smap_get_bool(&be_cfg->other_config,
                                               "enable-output-sampling", false);
+
+        virtual_obs_id = smap_get(&be_cfg->other_config, "virtual_obs_id");
+        be_opts.virtual_obs_id = virtual_obs_id ? xstrdup(virtual_obs_id)
+                                                : NULL;
     }
 
     if (n_fe_opts > 0) {
@@ -1228,6 +1233,10 @@  bridge_configure_ipfix(struct bridge *br)
                 opts->enable_tunnel_sampling = smap_get_bool(
                                                    &fe_cfg->ipfix->other_config,
                                                   "enable-tunnel-sampling", true);
+                virtual_obs_id = smap_get(&be_cfg->other_config,
+                                     "virtual_obs_id");
+                opts->virtual_obs_id = virtual_obs_id ? xstrdup(virtual_obs_id)
+                                                      : NULL;
                 opts++;
             }
         }
@@ -1238,6 +1247,7 @@  bridge_configure_ipfix(struct bridge *br)
 
     if (valid_be_cfg) {
         sset_destroy(&be_opts.targets);
+        free(be_opts.virtual_obs_id);
     }
 
     if (n_fe_opts > 0) {
@@ -1245,6 +1255,7 @@  bridge_configure_ipfix(struct bridge *br)
         size_t i;
         for (i = 0; i < n_fe_opts; i++) {
             sset_destroy(&opts->targets);
+            free(opts->virtual_obs_id);
             opts++;
         }
         free(fe_opts);
diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
index 6e0ee80..c2dd5ee 100644
--- a/vswitchd/vswitch.xml
+++ b/vswitchd/vswitch.xml
@@ -4743,6 +4743,40 @@ 
       </p>
     </column>
 
+    <column name="other_config" key="virtual_obs_id"
+            type='{"type": "string"}'>
+      The IPFIX virtual observation ID sent with each IPFIX flow reord.
+      It is an identifier of a virtual obsvervation point that is locally
+      unique in a virtual network. It describes a location in the virtual
+      network where IP packets can be observed. The max length is limited to
+      254 bytes.
+      If not specified or the length of the specified ID exceeds the max
+      length, nothing exported with IPFIX flow record.
+      <p>
+        The following enterprise entity reports the specified virtual
+        observation ID:
+      </p>
+
+      <dl>
+        <dt>virtualObsID:</dt>
+        <dd>
+          <p>ID: 898, and enterprise ID 6876 (VMware).</p>
+          <p>type: variable-length string.</p>
+          <p>data type semantics: identifier.</p>
+          <p>description: The Identifier of the virtual observation domain ID
+             that is locally unique in a virtual network.
+          </p>
+        </dd>
+      </dl>
+
+      <p>
+        Before Open vSwitch 2.5.90, <ref column="other_config"
+        key="virtual_obs_id"/> was not supported.  Open vSwitch 2.6 and later
+        support <ref column="other_config" key="virtual_obs_id"/> for
+        per-bridge and per-flow sampling.
+      </p>
+    </column>
+
     <group title="Per-Bridge Sampling">
       <p>
         These values affect only per-bridge sampling.  See above for a