ofproto-dpif: Expose datapath capability to ovsdb.

The patch adds support for fetching the datapath's capabilities
from the result of 'check_support()', and write the supported capability
to a new database column, called 'capabilities' under Datapath table.

To see how it works, run:
 # ovs-vsctl -- add-br br0 -- set Bridge br0 datapath_type=netdev
 # ovs-vsctl -- --id=@m create Datapath datapath_version=0 \
     'ct_zones={}' 'capabilities={}' \
     -- set Open_vSwitch . datapaths:"netdev"=@m

 # ovs-vsctl list-dp-cap netdev
 ufid=true sample_nesting=true clone=true tnl_push_pop=true \
 ct_orig_tuple=true ct_eventmask=true ct_state=true \
 ct_clear=true max_vlan_headers=1 recirc=true ct_label=true \
 max_hash_alg=1 ct_state_nat=true ct_timeout=true \
 ct_mark=true ct_orig_tuple6=true check_pkt_len=true \
 masked_set_action=true max_mpls_depth=3 trunc=true ct_zone=true

Signed-off-by: William Tu <u9012063@gmail.com>
Tested-by: Greg Rose <gvrose8192@gmail.com>
Reviewed-by: Greg Rose <gvrose8192@gmail.com>
---
v5:
    Add improved documentation from Ben and
    fix checkpatch error (tab and line 79 char)
v4:
    rebase to master
v3:
    fix 32-bit build, reported by Greg
    travis: https://travis-ci.org/williamtu/ovs-travis/builds/599276267
v2:
	rebase to master

lib/meta-flow.xml

@@ -2488,7 +2488,7 @@ actions=clone(load:0->NXM_OF_IN_PORT[],output:123)
 
   <group title="Connection Tracking">
     <p>
-      Open vSwitch 2.5 and later support ``connection tracking,'' which allows
+      Open vSwitch supports ``connection tracking,'' which allows
       bidirectional streams of packets to be statefully grouped into
       connections.  Open vSwitch connection tracking, for example, identifies
       the patterns of TCP packets that indicates a successfully initiated
@@ -2524,7 +2524,14 @@ actions=clone(load:0->NXM_OF_IN_PORT[],output:123)
     </p>
 
     <p>
-      Connection tracking is an Open vSwitch extension to OpenFlow.
+      Connection tracking is an Open vSwitch extension to OpenFlow.  Open
+      vSwitch 2.5 added the initial support for connection tracking.
+      Subsequent versions of Open vSwitch added many refinements and extensions
+      to the initial support.  Many of these capabilities depend on the Open
+      vSwitch datapath rather than simply the userspace version.  The
+      <code>capabilities</code> column in the <code>Datapath</code> table (see
+      <code>ovs-vswitchd.conf.db</code>(5)) reports the detailed capabilities
+      of a particular Open vSwitch datapath.
     </p>
 
     <field id="MFF_CT_STATE" title="Connection Tracking State">
@@ -2713,7 +2720,8 @@ actions=clone(load:0->NXM_OF_IN_PORT[],output:123)
     </p>
 
     <p>
-      The following fields are populated by the ct action, and require a
+      The following fields are populated by the <code>ct</code>
+      action, and require a
       match to a valid connection tracking state as a prerequisite, in
       addition to the IP or IPv6 ethertype match.  Examples of valid
       connection tracking state matches include <code>ct_state=+new</code>,

ofproto/ofproto-dpif.c

@@ -5444,6 +5444,56 @@ ct_del_zone_timeout_policy(const char *datapath_type, uint16_t zone_id)
     }
 }
 
+static void
+get_datapath_cap(const char *datapath_type, struct smap *cap)
+{
+    char *str_value;
+    struct odp_support odp;
+    struct dpif_backer_support s;
+    struct dpif_backer *backer = shash_find_data(&all_dpif_backers,
+                                                 datapath_type);
+    if (!backer) {
+        return;
+    }
+    s = backer->rt_support;
+    odp = s.odp;
+
+    /* ODP_SUPPORT_FIELDS */
+    str_value = xasprintf("%"PRIuSIZE, odp.max_vlan_headers);
+    smap_add(cap, "max_vlan_headers", str_value);
+    free(str_value);
+
+    str_value = xasprintf("%"PRIuSIZE, odp.max_mpls_depth);
+    smap_add(cap, "max_mpls_depth", str_value);
+    free(str_value);
+
+    smap_add(cap, "recirc", odp.recirc ? "true" : "false");
+    smap_add(cap, "ct_state", odp.ct_state ? "true" : "false");
+    smap_add(cap, "ct_zone", odp.ct_zone ? "true" : "false");
+    smap_add(cap, "ct_mark", odp.ct_mark ? "true" : "false");
+    smap_add(cap, "ct_label", odp.ct_label ? "true" : "false");
+    smap_add(cap, "ct_state_nat", odp.ct_state_nat ? "true" : "false");
+    smap_add(cap, "ct_orig_tuple", odp.ct_orig_tuple ? "true" : "false");
+    smap_add(cap, "ct_orig_tuple6", odp.ct_orig_tuple6 ? "true" : "false");
+
+    /* DPIF_SUPPORT_FIELDS */
+    smap_add(cap, "masked_set_action", s.masked_set_action ? "true" : "false");
+    smap_add(cap, "tnl_push_pop", s.tnl_push_pop ? "true" : "false");
+    smap_add(cap, "ufid", s.ufid ? "true" : "false");
+    smap_add(cap, "trunc", s.trunc ? "true" : "false");
+    smap_add(cap, "clone", s.clone ? "true" : "false");
+    smap_add(cap, "sample_nesting", s.sample_nesting ? "true" : "false");
+    smap_add(cap, "ct_eventmask", s.ct_eventmask ? "true" : "false");
+    smap_add(cap, "ct_clear", s.ct_clear ? "true" : "false");
+
+    str_value = xasprintf("%"PRIuSIZE, s.max_hash_alg);
+    smap_add(cap, "max_hash_alg", str_value);
+    free(str_value);
+
+    smap_add(cap, "check_pkt_len", s.check_pkt_len ? "true" : "false");
+    smap_add(cap, "ct_timeout", s.ct_timeout ? "true" : "false");
+}
+
 /* Gets timeout policy name in 'backer' based on 'zone', 'dl_type' and
  * 'nw_proto'.  Returns true if the zone-based timeout policy is configured.
  * On success, stores the timeout policy name in 'tp_name', and sets
@@ -6585,4 +6635,5 @@ const struct ofproto_class ofproto_dpif_class = {
     ct_flush,                   /* ct_flush */
     ct_set_zone_timeout_policy,
     ct_del_zone_timeout_policy,
+    get_datapath_cap,
 };

ofproto/ofproto-provider.h

@@ -1889,6 +1889,8 @@ struct ofproto_class {
     /* Deletes the timeout policy associated with 'zone' in datapath type
      * 'dp_type'. */
     void (*ct_del_zone_timeout_policy)(const char *dp_type, uint16_t zone);
+    /* Get the datapath's capabilities. */
+    void (*get_datapath_cap)(const char *dp_type, struct smap *caps);
 };
 
 extern const struct ofproto_class ofproto_dpif_class;

ofproto/ofproto.c

@@ -954,6 +954,18 @@ ofproto_get_flow_restore_wait(void)
     return flow_restore_wait;
 }
 
+/* Retrieve datapath capabilities. */
+void
+ofproto_get_datapath_cap(const char *datapath_type, struct smap *dp_cap)
+{
+    datapath_type = ofproto_normalize_type(datapath_type);
+    const struct ofproto_class *class = ofproto_class_find__(datapath_type);
+
+    if (class->get_datapath_cap) {
+        class->get_datapath_cap(datapath_type, dp_cap);
+    }
+}
+
 /* Connection tracking configuration. */
 void
 ofproto_ct_set_zone_timeout_policy(const char *datapath_type, uint16_t zone_id,

ofproto/ofproto.h

@@ -372,6 +372,8 @@ void ofproto_ct_set_zone_timeout_policy(const char *datapath_type,
                                         struct simap *timeout_policy);
 void ofproto_ct_del_zone_timeout_policy(const char *datapath_type,
                                         uint16_t zone);
+void ofproto_get_datapath_cap(const char *datapath_type,
+                              struct smap *dp_cap);
 
 /* Configuration of ports. */
 void ofproto_port_unregister(struct ofproto *, ofp_port_t ofp_port);

tests/ovs-vsctl.at

@@ -819,6 +819,10 @@ AT_CHECK([RUN_OVS_VSCTL([del-zone-tp netdev zone=1])])
 AT_CHECK([RUN_OVS_VSCTL([--if-exists del-zone-tp netdev zone=1])])
 AT_CHECK([RUN_OVS_VSCTL([list-zone-tp netdev])], [0], [Zone:2, Timeout Policies: icmp_first=2 icmp_reply=3
 ])
+
+AT_CHECK([RUN_OVS_VSCTL([-- --id=@m create Datapath datapath_version=0 'capabilities={recirc=true}' -- set Open_vSwitch . datapaths:"system"=@m])], [0], [stdout])
+AT_CHECK([RUN_OVS_VSCTL([list-dp-cap system])], [0], [recirc=true
+])
 OVS_VSCTL_CLEANUP
 AT_CLEANUP
 
@@ -962,6 +966,12 @@ AT_CHECK([RUN_OVS_VSCTL([del-zone-tp netdev zone=11])],
 ])
 AT_CHECK([RUN_OVS_VSCTL([list-zone-tp netdev])], [0], [Zone:2, Timeout Policies: icmp_first=2 icmp_reply=3
 ])
+
+AT_CHECK([RUN_OVS_VSCTL([-- --id=@m create Datapath datapath_version=0 'capabilities={recirc=true}' -- set Open_vSwitch . datapaths:"system"=@m])], [0], [stdout])
+AT_CHECK([RUN_OVS_VSCTL([list-dp-cap nosystem])],
+  [1], [], [ovs-vsctl: datapath "nosystem" record not found
+])
+
 OVS_VSCTL_CLEANUP
 AT_CLEANUP
 

utilities/ovs-vsctl.8.in

@@ -379,6 +379,12 @@ delete a zone that does not exist has no effect.
 .IP "\fBlist\-zone\-tp \fIdatapath\fR"
 Prints the timeout policies of all zones in \fIdatapath\fR.
 .
+.SS "Datapath Capabilities Command"
+The command query datapath capabilities.
+.
+.IP "\fBlist\-dp\-cap \fIdatapath\fR"
+Prints the datapath's capabilities.
+.
 .SS "OpenFlow Controller Connectivity"
 .
 \fBovs\-vswitchd\fR can perform all configured bridging and switching

utilities/ovs-vsctl.c

@@ -1362,6 +1362,31 @@ pre_get_zone(struct ctl_context *ctx)
     ovsdb_idl_add_column(ctx->idl, &ovsrec_ct_timeout_policy_col_timeouts);
 }
 
+static void
+pre_get_dp_cap(struct ctl_context *ctx)
+{
+    ovsdb_idl_add_column(ctx->idl, &ovsrec_open_vswitch_col_datapaths);
+    ovsdb_idl_add_column(ctx->idl, &ovsrec_datapath_col_capabilities);
+}
+
+static void
+cmd_list_dp_cap(struct ctl_context *ctx)
+{
+    struct vsctl_context *vsctl_ctx = vsctl_context_cast(ctx);
+    struct smap_node *node;
+
+    struct ovsrec_datapath *dp = find_datapath(vsctl_ctx, ctx->argv[1]);
+    if (!dp) {
+        ctl_fatal("datapath \"%s\" record not found", ctx->argv[1]);
+    }
+
+    SMAP_FOR_EACH (node, &dp->capabilities) {
+        ds_put_format(&ctx->output, "%s=%s ",node->key, node->value);
+    }
+    ds_chomp(&ctx->output, ' ');
+    ds_put_char(&ctx->output, '\n');
+}
+
 static void
 cmd_add_br(struct ctl_context *ctx)
 {
@@ -3112,6 +3137,9 @@ static const struct ctl_command_syntax vsctl_commands[] = {
      "--if-exists", RW},
     {"list-zone-tp", 1, 1, "", pre_get_zone, cmd_list_zone_tp, NULL, "", RO},
 
+    /* Datapath capabilities. */
+    {"list-dp-cap", 1, 1, "", pre_get_dp_cap, cmd_list_dp_cap, NULL, "", RO},
+
     {NULL, 0, 0, NULL, NULL, NULL, NULL, NULL, RO},
 };
 

vswitchd/bridge.c

@@ -171,6 +171,7 @@ struct datapath {
     struct hmap ct_zones;       /* Map of 'struct ct_zone' elements, indexed
                                  * by 'zone'. */
     struct hmap_node node;      /* Node in 'all_datapaths' hmap. */
+    struct smap caps;           /* Capabilities. */
     unsigned int last_used;     /* The last idl_seqno that this 'datapath'
                                  * used in OVSDB. This number is used for
                                  * garbage collection. */
@@ -700,6 +701,7 @@ datapath_create(const char *type)
     dp->type = xstrdup(type);
     hmap_init(&dp->ct_zones);
     hmap_insert(&all_datapaths, &dp->node, hash_string(type, 0));
+    smap_init(&dp->caps);
     return dp;
 }
 
@@ -716,6 +718,7 @@ datapath_destroy(struct datapath *dp)
         hmap_remove(&all_datapaths, &dp->node);
         hmap_destroy(&dp->ct_zones);
         free(dp->type);
+        smap_destroy(&dp->caps);
         free(dp);
     }
 }
@@ -758,6 +761,23 @@ ct_zones_reconfigure(struct datapath *dp, struct ovsrec_datapath *dp_cfg)
     }
 }
 
+static void
+dp_capability_reconfigure(struct datapath *dp,
+                          struct ovsrec_datapath *dp_cfg)
+{
+    struct smap_node *node;
+    struct smap cap;
+
+    smap_init(&cap);
+    ofproto_get_datapath_cap(dp->type, &cap);
+
+    SMAP_FOR_EACH (node, &cap) {
+        ovsrec_datapath_update_capabilities_setkey(dp_cfg, node->key,
+                                                   node->value);
+    }
+    smap_destroy(&cap);
+}
+
 static void
 datapath_reconfigure(const struct ovsrec_open_vswitch *cfg)
 {
@@ -771,6 +791,7 @@ datapath_reconfigure(const struct ovsrec_open_vswitch *cfg)
         dp = datapath_lookup(dp_name);
         if (!dp) {
             dp = datapath_create(dp_name);
+            dp_capability_reconfigure(dp, dp_cfg);
         }
         dp->last_used = idl_seqno;
         ct_zones_reconfigure(dp, dp_cfg);

vswitchd/vswitch.ovsschema

@@ -1,6 +1,6 @@
 {"name": "Open_vSwitch",
  "version": "8.2.0",
- "cksum": "4076590391 26298",
+ "cksum": "1076640191 26427",
  "tables": {
    "Open_vSwitch": {
      "columns": {
@@ -650,6 +650,9 @@
                   "value": {"type": "uuid",
                             "refTable": "CT_Zone"},
                   "min": 0, "max": "unlimited"}},
+       "capabilities": {
+         "type": {"key": "string", "value": "string",
+                  "min": 0, "max": "unlimited"}},
        "external_ids": {
          "type": {"key": "string", "value": "string",
                   "min": 0, "max": "unlimited"}}}},