sFlow: Genericize/simplify kernel sFlow implementation

Following patch adds sampling action which takes probability and set
of actions as arguments. When probability is hit, actions are executed for
given packet.
USERSPACE action's userdata (u64) is used to store struct
user_action_cookie as cookie. CONTROLLER action is fixed accordingly.

Now we can remove sFlow code from kernel and implement sFlow generically
as SAMPLE action. sFlow is defined as SAMPLE Action with probability (sFlow
sampling rate) and USERSPACE action as argument. USERSPACE action's data
is used as cookie. sFlow uses this cookie to store output-port, number of
output ports and vlan-id. sample-pool is calculated by using vport
stats.

Signed-off-by: Pravin Shelar <pshelar@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>

1 files changed, 57 insertions, 2 deletions

diff --git a/lib/odp-util.c b/lib/odp-util.c
index 3d943981..d97d30c0 100644
--- a/lib/odp-util.c
+++ b/lib/odp-util.c
@@ -62,6 +62,7 @@ odp_action_len(uint16_t type)
     case OVS_ACTION_ATTR_SET_PRIORITY: return 4;
     case OVS_ACTION_ATTR_POP_PRIORITY: return 0;
 
+    case OVS_ACTION_ATTR_SAMPLE:
     case OVS_ACTION_ATTR_UNSPEC:
     case __OVS_ACTION_ATTR_MAX:
         return -1;
@@ -89,13 +90,50 @@ format_generic_odp_action(struct ds *ds, const struct nlattr *a)
     }
 }
 
+static void
+format_odp_sample_action(struct ds *ds, const struct nlattr *attr)
+{
+    static const struct nl_policy ovs_sample_policy[] = {
+        [OVS_SAMPLE_ATTR_PROBABILITY] = { .type = NL_A_U32 },
+        [OVS_SAMPLE_ATTR_ACTIONS] = { .type = NL_A_NESTED }
+    };
+    struct nlattr *a[ARRAY_SIZE(ovs_sample_policy)];
+    struct ofpbuf buf;
+    double percentage;
+    const struct nlattr *nla_acts;
+    int len;
+
+    ds_put_cstr(ds, "sample");
+
+    ofpbuf_use_const(&buf, nl_attr_get(attr), nl_attr_get_size(attr));
+    if (!nl_policy_parse(&buf, 0, ovs_sample_policy, a,
+                            ARRAY_SIZE(ovs_sample_policy))) {
+        ds_put_cstr(ds, "(error)");
+        return;
+    }
+
+    percentage = (100.0 * nl_attr_get_u32(a[OVS_SAMPLE_ATTR_PROBABILITY])) /
+                        UINT32_MAX;
+
+    ds_put_format(ds, "(sample=%.1f%%,", percentage);
+
+    ds_put_cstr(ds, "actions(");
+    nla_acts = nl_attr_get(a[OVS_SAMPLE_ATTR_ACTIONS]);
+    len = nl_attr_get_size(a[OVS_SAMPLE_ATTR_ACTIONS]);
+    format_odp_actions(ds, nla_acts, len);
+    ds_put_format(ds, "))");
+}
+
 void
 format_odp_action(struct ds *ds, const struct nlattr *a)
 {
     const uint8_t *eth;
     ovs_be32 ip;
+    struct user_action_cookie cookie;
+    uint64_t data;
 
-    if (nl_attr_get_size(a) != odp_action_len(nl_attr_type(a))) {
+    if (nl_attr_get_size(a) != odp_action_len(nl_attr_type(a)) &&
+            nl_attr_type(a) != OVS_ACTION_ATTR_SAMPLE) {
         ds_put_format(ds, "bad length %zu, expected %d for: ",
                       nl_attr_get_size(a), odp_action_len(nl_attr_type(a)));
         format_generic_odp_action(ds, a);
@@ -107,7 +145,21 @@ format_odp_action(struct ds *ds, const struct nlattr *a)
         ds_put_format(ds, "%"PRIu16, nl_attr_get_u32(a));
         break;
     case OVS_ACTION_ATTR_USERSPACE:
-        ds_put_format(ds, "userspace(%"PRIu64")", nl_attr_get_u64(a));
+        data = nl_attr_get_u64(a);
+        memcpy(&cookie, &data, sizeof(cookie));
+
+        if (cookie.type == USER_ACTION_COOKIE_CONTROLLER) {
+            ds_put_format(ds, "userspace(controller,length=%"PRIu32")",
+                          cookie.data);
+        } else if (cookie.type == USER_ACTION_COOKIE_SFLOW) {
+            ds_put_format(ds, "userspace(sFlow,n_output=%"PRIu8","
+                          "vid=%"PRIu16",pcp=%"PRIu8",ifindex=%"PRIu32")",
+                          cookie.n_output, vlan_tci_to_vid(cookie.vlan_tci),
+                          vlan_tci_to_pcp(cookie.vlan_tci), cookie.data);
+        } else {
+            ds_put_format(ds, "userspace(unknown,data=0x%"PRIx64")",
+                          nl_attr_get_u64(a));
+        }
         break;
     case OVS_ACTION_ATTR_SET_TUNNEL:
         ds_put_format(ds, "set_tunnel(%#"PRIx64")",
@@ -152,6 +204,9 @@ format_odp_action(struct ds *ds, const struct nlattr *a)
     case OVS_ACTION_ATTR_POP_PRIORITY:
         ds_put_cstr(ds, "pop_priority");
         break;
+    case OVS_ACTION_ATTR_SAMPLE:
+        format_odp_sample_action(ds, a);
+        break;
     default:
         format_generic_odp_action(ds, a);
         break;