[ovs-dev] [PATCH v16 7/8] netdev-offload-tc: Add offload support for sFlow

Chris Mi cmi at nvidia.com
Tue Oct 12 08:19:36 UTC 2021


Create a unique group ID to map the sFlow info when offloading sFlow
action to TC. When showing the offloaded datapath flows, translate the
group ID from TC sample action to sFlow info using the mapping.

Signed-off-by: Chris Mi <cmi at nvidia.com>
Reviewed-by: Eli Britstein <elibr at nvidia.com>
---
 NEWS                        |   1 +
 lib/dpif-netlink.c          |   1 +
 lib/dpif-offload-netlink.c  |   6 +
 lib/dpif-offload-provider.h |   1 +
 lib/netdev-offload-tc.c     | 228 +++++++++++++++++++++++++++++++++---
 lib/netdev-offload.h        |   3 +
 lib/tc.c                    |  61 +++++++++-
 lib/tc.h                    |  15 ++-
 8 files changed, 294 insertions(+), 22 deletions(-)

diff --git a/NEWS b/NEWS
index 90f4b1590..d34c87b3c 100644
--- a/NEWS
+++ b/NEWS
@@ -10,6 +10,7 @@ Post-v2.16.0
        limiting behavior.
      * Add hardware offload support for matching IPv4/IPv6 frag types
        (experimental).
+   - Add sFlow offload support for kernel (netlink) datapath.
 
 
 v2.16.0 - 16 Aug 2021
diff --git a/lib/dpif-netlink.c b/lib/dpif-netlink.c
index 19ae543e6..3f51f319f 100644
--- a/lib/dpif-netlink.c
+++ b/lib/dpif-netlink.c
@@ -2234,6 +2234,7 @@ parse_flow_put(struct dpif_netlink *dpif, struct dpif_flow_put *put)
     info.tunnel_csum_on = csum_on;
     info.recirc_id_shared_with_tc = (dpif->user_features
                                      & OVS_DP_F_TC_RECIRC_SHARING);
+    info.psample_exists = dpif_offload_netlink_psample_exists();
     err = netdev_flow_put(dev, &match,
                           CONST_CAST(struct nlattr *, put->actions),
                           put->actions_len,
diff --git a/lib/dpif-offload-netlink.c b/lib/dpif-offload-netlink.c
index 6ebf1aa0c..4db71ecea 100644
--- a/lib/dpif-offload-netlink.c
+++ b/lib/dpif-offload-netlink.c
@@ -207,3 +207,9 @@ const struct dpif_offload_api dpif_offload_netlink = {
     .sflow_recv_wait = dpif_offload_netlink_sflow_recv_wait,
     .sflow_recv = dpif_offload_netlink_sflow_recv,
 };
+
+bool
+dpif_offload_netlink_psample_exists(void)
+{
+    return psample_sock != NULL;
+}
diff --git a/lib/dpif-offload-provider.h b/lib/dpif-offload-provider.h
index 0a0b71618..573f3add5 100644
--- a/lib/dpif-offload-provider.h
+++ b/lib/dpif-offload-provider.h
@@ -69,6 +69,7 @@ int dpif_offload_sflow_recv(const struct dpif *dpif,
                             struct dpif_offload_sflow *sflow);
 
 #ifdef __linux__
+bool dpif_offload_netlink_psample_exists(void);
 extern const struct dpif_offload_api dpif_offload_netlink;
 #endif
 
diff --git a/lib/netdev-offload-tc.c b/lib/netdev-offload-tc.c
index 204d1c833..a47a8e2c1 100644
--- a/lib/netdev-offload-tc.c
+++ b/lib/netdev-offload-tc.c
@@ -20,6 +20,7 @@
 #include <linux/if_ether.h>
 
 #include "dpif.h"
+#include "dpif-offload-provider.h"
 #include "hash.h"
 #include "openvswitch/hmap.h"
 #include "openvswitch/match.h"
@@ -1052,6 +1053,19 @@ parse_tc_flower_to_match(struct tc_flower *flower,
         action = flower->actions;
         for (i = 0; i < flower->action_count; i++, action++) {
             switch (action->type) {
+            case TC_ACT_SAMPLE: {
+                const struct sgid_node *node;
+
+                node = sgid_find(action->sample.group_id);
+                if (!node) {
+                    VLOG_WARN("Can't find sample group ID data for ID: %u",
+                              action->sample.group_id);
+                    return ENOENT;
+                }
+                nl_msg_put(buf, node->sflow.action,
+                           node->sflow.action->nla_len);
+            }
+            break;
             case TC_ACT_VLAN_POP: {
                 nl_msg_put_flag(buf, OVS_ACTION_ATTR_POP_VLAN);
             }
@@ -1790,6 +1804,151 @@ parse_match_ct_state_to_flower(struct tc_flower *flower, struct match *match)
     }
 }
 
+static int
+parse_userspace_attributes(const struct nlattr *actions,
+                           struct dpif_sflow_attr *sflow_attr)
+{
+    static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
+    const struct nlattr *nla;
+    unsigned int left;
+
+    NL_NESTED_FOR_EACH_UNSAFE (nla, left, actions) {
+        if (nl_attr_type(nla) == OVS_USERSPACE_ATTR_USERDATA) {
+            struct user_action_cookie *cookie;
+
+            cookie = CONST_CAST(struct user_action_cookie *, nl_attr_get(nla));
+            if (cookie->type == USER_ACTION_COOKIE_SFLOW) {
+                sflow_attr->userdata = nla;
+                return 0;
+            }
+        }
+    }
+
+    VLOG_DBG_RL(&rl, "Can't offload userspace action other than sFlow.");
+    return EOPNOTSUPP;
+}
+
+static int
+parse_sample_actions_attribute(const struct nlattr *actions,
+                               struct dpif_sflow_attr *sflow_attr)
+{
+    static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
+    const struct nlattr *nla;
+    unsigned int left;
+    int err = EINVAL;
+
+    NL_NESTED_FOR_EACH_UNSAFE (nla, left, actions) {
+        if (nl_attr_type(nla) == OVS_ACTION_ATTR_USERSPACE) {
+            err = parse_userspace_attributes(nla, sflow_attr);
+        } else {
+            /* We can't offload other nested actions */
+            VLOG_DBG_RL(&rl, "Can only offload OVS_ACTION_ATTR_USERSPACE"
+                             " attribute.");
+            return EINVAL;
+        }
+    }
+
+    if (err) {
+        VLOG_ERR_RL(&error_rl, "No OVS_ACTION_ATTR_USERSPACE attribute.");
+    }
+    return err;
+}
+
+static int
+parse_sample_action(struct tc_flower *flower, struct tc_action *tc_action,
+                    const struct nlattr *sample_action,
+                    const struct flow_tnl *tnl, uint32_t *group_id,
+                    const ovs_u128 *ufid)
+{
+    static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
+    struct dpif_sflow_attr sflow_attr;
+    const struct nlattr *nla;
+    unsigned int left;
+    int ret = EINVAL;
+
+    if (*group_id) {
+        VLOG_ERR_RL(&error_rl, " Only a single TC_SAMPLE action per flow is"
+                    " supported");
+        return EOPNOTSUPP;
+    }
+
+    memset(&sflow_attr, 0, sizeof sflow_attr);
+    sflow_attr.ufid = *ufid;
+    sflow_attr.action = sample_action;
+
+    if (flower->tunnel) {
+        sflow_attr.tunnel = CONST_CAST(struct flow_tnl *, tnl);
+    }
+
+    NL_NESTED_FOR_EACH_UNSAFE (nla, left, sample_action) {
+        if (nl_attr_type(nla) == OVS_SAMPLE_ATTR_ACTIONS) {
+            ret = parse_sample_actions_attribute(nla, &sflow_attr);
+        } else if (nl_attr_type(nla) == OVS_SAMPLE_ATTR_PROBABILITY) {
+            tc_action->type = TC_ACT_SAMPLE;
+            tc_action->sample.rate = UINT32_MAX / nl_attr_get_u32(nla);
+        } else {
+            return EINVAL;
+        }
+    }
+
+    if (!tc_action->sample.rate || ret) {
+        return EINVAL;
+    }
+
+    *group_id = sgid_alloc_ctx(&sflow_attr);
+    if (!*group_id) {
+        VLOG_DBG_RL(&rl, "Failed allocating group id for sample action");
+        return ENOENT;
+    }
+    tc_action->sample.group_id = *group_id;
+    flower->action_count++;
+
+    return 0;
+}
+
+static int
+parse_userspace_action(struct tc_flower *flower, struct tc_action *tc_action,
+                       const struct nlattr *userspace_action,
+                       const struct flow_tnl *tnl, uint32_t *group_id,
+                       const ovs_u128 *ufid)
+{
+    static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
+    struct dpif_sflow_attr sflow_attr;
+    int err;
+
+    if (*group_id) {
+        VLOG_ERR_RL(&error_rl, "Only a single TC_SAMPLE action per flow is"
+                    " supported.");
+        return EOPNOTSUPP;
+    }
+
+    /* If sampling rate is 1, there is only a sFlow cookie inside of a
+     * userspace action, but no sample attribute. That means we can
+     * only offload userspace actions for sFlow.
+     */
+    memset(&sflow_attr, 0, sizeof sflow_attr);
+    sflow_attr.ufid = *ufid;
+    if (flower->tunnel) {
+        sflow_attr.tunnel = CONST_CAST(struct flow_tnl *, tnl);
+    }
+    err = parse_userspace_attributes(userspace_action, &sflow_attr);
+    if (err) {
+        return err;
+    }
+    sflow_attr.action = userspace_action;
+    *group_id = sgid_alloc_ctx(&sflow_attr);
+    if (!*group_id) {
+        VLOG_DBG_RL(&rl, "Failed allocating group id for sample action.");
+        return ENOENT;
+    }
+    tc_action->type = TC_ACT_SAMPLE;
+    tc_action->sample.group_id = *group_id;
+    tc_action->sample.rate = 1;
+    flower->action_count++;
+
+    return 0;
+}
+
 static int
 netdev_tc_flow_put(struct netdev *netdev, struct match *match,
                    struct nlattr *actions, size_t actions_len,
@@ -1805,6 +1964,7 @@ netdev_tc_flow_put(struct netdev *netdev, struct match *match,
     const struct flow_tnl *tnl_mask = &mask->tunnel;
     struct tc_action *action;
     bool recirc_act = false;
+    uint32_t sample_gid = 0;
     uint32_t block_id = 0;
     struct nlattr *nla;
     struct tcf_id id;
@@ -2057,7 +2217,8 @@ netdev_tc_flow_put(struct netdev *netdev, struct match *match,
     NL_ATTR_FOR_EACH(nla, left, actions, actions_len) {
         if (flower.action_count >= TCA_ACT_MAX_NUM) {
             VLOG_DBG_RL(&rl, "Can only support %d actions", TCA_ACT_MAX_NUM);
-            return EOPNOTSUPP;
+            err = EOPNOTSUPP;
+            goto out;
         }
         action = &flower.actions[flower.action_count];
         if (nl_attr_type(nla) == OVS_ACTION_ATTR_OUTPUT) {
@@ -2067,7 +2228,8 @@ netdev_tc_flow_put(struct netdev *netdev, struct match *match,
 
             if (!outdev) {
                 VLOG_DBG_RL(&rl, "Can't find netdev for output port %d", port);
-                return ENODEV;
+                err = ENODEV;
+                goto out;
             }
             action->out.ifindex_out = netdev_get_ifindex(outdev);
             action->out.ingress = is_internal_port(netdev_get_type(outdev));
@@ -2105,7 +2267,7 @@ netdev_tc_flow_put(struct netdev *netdev, struct match *match,
 
             err = parse_put_flow_set_action(&flower, action, set, set_len);
             if (err) {
-                return err;
+                goto out;
             }
             if (action->type == TC_ACT_ENCAP) {
                 action->encap.tp_dst = info->tp_dst_port;
@@ -2118,7 +2280,7 @@ netdev_tc_flow_put(struct netdev *netdev, struct match *match,
             err = parse_put_flow_set_masked_action(&flower, action, set,
                                                    set_len, true);
             if (err) {
-                return err;
+                goto out;
             }
         } else if (nl_attr_type(nla) == OVS_ACTION_ATTR_CT) {
             const struct nlattr *ct = nl_attr_get(nla);
@@ -2130,7 +2292,7 @@ netdev_tc_flow_put(struct netdev *netdev, struct match *match,
 
             err = parse_put_flow_ct_action(&flower, action, ct, ct_len);
             if (err) {
-                return err;
+                goto out;
             }
         } else if (nl_attr_type(nla) == OVS_ACTION_ATTR_CT_CLEAR) {
             action->type = TC_ACT_CT;
@@ -2146,20 +2308,41 @@ netdev_tc_flow_put(struct netdev *netdev, struct match *match,
             action->chain = 0;  /* 0 is reserved and not used by recirc. */
             flower.action_count++;
         } else if (nl_attr_type(nla) == OVS_ACTION_ATTR_SAMPLE) {
-            struct dpif_sflow_attr sflow_attr;
-
-            memset(&sflow_attr, 0, sizeof sflow_attr);
-            sgid_alloc_ctx(&sflow_attr);
+            if (!info->psample_exists) {
+                VLOG_DBG_RL(&rl, "unsupported put action type: %d, psample is"
+                            "not initialized successfully", nl_attr_type(nla));
+                err = EOPNOTSUPP;
+                goto out;
+            }
+            err = parse_sample_action(&flower, action, nla, tnl, &sample_gid,
+                                      ufid);
+            if (err) {
+                goto out;
+            }
+        } else if (nl_attr_type(nla) == OVS_ACTION_ATTR_USERSPACE) {
+            if (!info->psample_exists) {
+                VLOG_DBG_RL(&rl, "unsupported put action type: %d, psample is"
+                            "not initialized successfully", nl_attr_type(nla));
+                err = EOPNOTSUPP;
+                goto out;
+            }
+            err = parse_userspace_action(&flower, action, nla, tnl,
+                                         &sample_gid, ufid);
+            if (err) {
+                goto out;
+            }
         } else {
             VLOG_DBG_RL(&rl, "unsupported put action type: %d",
                         nl_attr_type(nla));
-            return EOPNOTSUPP;
+            err = EOPNOTSUPP;
+            goto out;
         }
     }
 
     if ((chain || recirc_act) && !info->recirc_id_shared_with_tc) {
         VLOG_ERR_RL(&error_rl, "flow_put: recirc_id sharing not supported");
-        return EOPNOTSUPP;
+        err = EOPNOTSUPP;
+        goto out;
     }
 
     if (get_ufid_tc_mapping(ufid, &id) == 0) {
@@ -2172,20 +2355,29 @@ netdev_tc_flow_put(struct netdev *netdev, struct match *match,
     prio = get_prio_for_tc_flower(&flower);
     if (prio == 0) {
         VLOG_ERR_RL(&rl, "couldn't get tc prio: %s", ovs_strerror(ENOSPC));
-        return ENOSPC;
+        err = ENOSPC;
+        goto out;
     }
 
     flower.act_cookie.data = ufid;
     flower.act_cookie.len = sizeof *ufid;
 
     block_id = get_block_id_from_netdev(netdev);
-    id = tc_make_tcf_id_chain(ifindex, block_id, chain, prio, hook);
+    id = tc_make_tcf_id_all(ifindex, block_id, chain, prio, hook, sample_gid);
     err = tc_replace_flower(&id, &flower);
-    if (!err) {
-        if (stats) {
-            memset(stats, 0, sizeof *stats);
-        }
-        add_ufid_tc_mapping(netdev, ufid, &id);
+    if (err) {
+        goto out;
+    }
+
+    if (stats) {
+        memset(stats, 0, sizeof *stats);
+    }
+    add_ufid_tc_mapping(netdev, ufid, &id);
+    return 0;
+
+out:
+    if (sample_gid) {
+        sgid_free(sample_gid);
     }
 
     return err;
diff --git a/lib/netdev-offload.h b/lib/netdev-offload.h
index c570b4e62..96d32382f 100644
--- a/lib/netdev-offload.h
+++ b/lib/netdev-offload.h
@@ -77,6 +77,9 @@ struct offload_info {
     bool tc_modify_flow_deleted; /* Indicate the tc modify flow put success
                                   * to delete the original flow. */
     odp_port_t orig_in_port; /* Originating in_port for tnl flows. */
+    bool psample_exists;  /* Indicate psample is initialized successfully.
+                           * Otherwise, return error when offloading sample
+                           * action. */
 };
 
 int netdev_flow_flush(struct netdev *);
diff --git a/lib/tc.c b/lib/tc.c
index 38a1dfc0e..dc8db6b22 100644
--- a/lib/tc.c
+++ b/lib/tc.c
@@ -23,14 +23,15 @@
 #include <linux/if_packet.h>
 #include <linux/rtnetlink.h>
 #include <linux/tc_act/tc_csum.h>
+#include <linux/tc_act/tc_ct.h>
 #include <linux/tc_act/tc_gact.h>
 #include <linux/tc_act/tc_mirred.h>
 #include <linux/tc_act/tc_mpls.h>
 #include <linux/tc_act/tc_pedit.h>
+#include <linux/tc_act/tc_sample.h>
 #include <linux/tc_act/tc_skbedit.h>
 #include <linux/tc_act/tc_tunnel_key.h>
 #include <linux/tc_act/tc_vlan.h>
-#include <linux/tc_act/tc_ct.h>
 #include <linux/gen_stats.h>
 #include <net/if.h>
 #include <unistd.h>
@@ -1341,6 +1342,38 @@ nl_parse_act_gact(struct nlattr *options, struct tc_flower *flower)
     return 0;
 }
 
+static const struct nl_policy sample_policy[] = {
+    [TCA_SAMPLE_PARMS] = { .type = NL_A_UNSPEC,
+                           .min_len = sizeof(struct tc_sample),
+                           .optional = false, },
+    [TCA_SAMPLE_PSAMPLE_GROUP] = { .type = NL_A_U32,
+                                   .optional = false, },
+    [TCA_SAMPLE_RATE] = { .type = NL_A_U32,
+                          .optional = false, },
+};
+
+static int
+nl_parse_act_sample(struct nlattr *options, struct tc_flower *flower)
+{
+    struct nlattr *sample_attrs[ARRAY_SIZE(sample_policy)];
+    struct tc_action *action;
+
+    if (!nl_parse_nested(options, sample_policy, sample_attrs,
+                         ARRAY_SIZE(sample_policy))) {
+        VLOG_ERR_RL(&error_rl, "failed to parse sample action options");
+        return EPROTO;
+    }
+
+    action = &flower->actions[flower->action_count++];
+    action->type = TC_ACT_SAMPLE;
+    action->sample.group_id =
+        nl_attr_get_u32(sample_attrs[TCA_SAMPLE_PSAMPLE_GROUP]);
+    action->sample.rate =
+        nl_attr_get_u32(sample_attrs[TCA_SAMPLE_RATE]);
+
+    return 0;
+}
+
 static const struct nl_policy mirred_policy[] = {
     [TCA_MIRRED_PARMS] = { .type = NL_A_UNSPEC,
                            .min_len = sizeof(struct tc_mirred),
@@ -1749,6 +1782,8 @@ nl_parse_single_action(struct nlattr *action, struct tc_flower *flower,
         /* Added for TC rule only (not in OvS rule) so ignore. */
     } else if (!strcmp(act_kind, "ct")) {
         nl_parse_act_ct(act_options, flower);
+    } else if (!strcmp(act_kind, "sample")) {
+        nl_parse_act_sample(act_options, flower);
     } else {
         VLOG_ERR_RL(&error_rl, "unknown tc action kind: %s", act_kind);
         err = EINVAL;
@@ -2375,6 +2410,23 @@ nl_msg_put_act_mirred(struct ofpbuf *request, int ifindex, int action,
     nl_msg_end_nested(request, offset);
 }
 
+static void
+nl_msg_put_act_sample(struct ofpbuf *request, uint32_t rate, uint32_t group_id)
+{
+    size_t offset;
+
+    nl_msg_put_string(request, TCA_ACT_KIND, "sample");
+    offset = nl_msg_start_nested(request, TCA_ACT_OPTIONS | NLA_F_NESTED);
+    {
+        struct tc_sample parm = { .action = TC_ACT_PIPE };
+
+        nl_msg_put_unspec(request, TCA_SAMPLE_PARMS, &parm, sizeof parm);
+        nl_msg_put_u32(request, TCA_SAMPLE_RATE, rate);
+        nl_msg_put_u32(request, TCA_SAMPLE_PSAMPLE_GROUP, group_id);
+    }
+    nl_msg_end_nested(request, offset);
+}
+
 static inline void
 nl_msg_put_act_cookie(struct ofpbuf *request, struct tc_cookie *ck) {
     if (ck->len) {
@@ -2634,6 +2686,13 @@ nl_msg_put_flower_acts(struct ofpbuf *request, struct tc_flower *flower)
                 nl_msg_end_nested(request, act_offset);
             }
             break;
+            case TC_ACT_SAMPLE: {
+                act_offset = nl_msg_start_nested(request, act_index++);
+                nl_msg_put_act_sample(request, action->sample.rate,
+                                      action->sample.group_id);
+                nl_msg_end_nested(request, act_offset);
+            }
+            break;
             case TC_ACT_OUTPUT: {
                 if (!released && flower->tunnel) {
                     act_offset = nl_msg_start_nested(request, act_index++);
diff --git a/lib/tc.h b/lib/tc.h
index 2e4084f48..f764d7d1e 100644
--- a/lib/tc.h
+++ b/lib/tc.h
@@ -174,6 +174,7 @@ enum tc_action_type {
     TC_ACT_MPLS_SET,
     TC_ACT_GOTO,
     TC_ACT_CT,
+    TC_ACT_SAMPLE,
 };
 
 enum nat_type {
@@ -256,6 +257,11 @@ struct tc_action {
             bool force;
             bool commit;
         } ct;
+
+        struct {
+            uint32_t rate;
+            uint32_t group_id;
+        } sample;
      };
 
      enum tc_action_type type;
@@ -294,12 +300,14 @@ tc_make_tcf_id(int ifindex, uint32_t block_id, uint16_t prio,
 }
 
 static inline struct tcf_id
-tc_make_tcf_id_chain(int ifindex, uint32_t block_id, uint32_t chain,
-                     uint16_t prio, enum tc_qdisc_hook hook)
+tc_make_tcf_id_all(int ifindex, uint32_t block_id, uint32_t chain,
+                     uint16_t prio, enum tc_qdisc_hook hook,
+                     uint32_t sample_group_id)
 {
     struct tcf_id id = tc_make_tcf_id(ifindex, block_id, prio, hook);
 
     id.chain = chain;
+    id.sample_group_id = sample_group_id;
 
     return id;
 }
@@ -313,7 +321,8 @@ is_tcf_id_eq(struct tcf_id *id1, struct tcf_id *id2)
            && id1->hook == id2->hook
            && id1->block_id == id2->block_id
            && id1->ifindex == id2->ifindex
-           && id1->chain == id2->chain;
+           && id1->chain == id2->chain
+           && id1->sample_group_id == id2->sample_group_id;
 }
 
 enum tc_offload_policy {
-- 
2.30.2



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