net: sched: introduce terse dump flag

Add new TCA_DUMP_FLAGS attribute and use it in cls API to request terse
filter output from classifiers with TCA_DUMP_FLAGS_TERSE flag. This option
is intended to be used to improve performance of TC filter dump when
userland only needs to obtain stats and not the whole classifier/action
data. Extend struct tcf_proto_ops with new terse_dump() callback that must
be defined by supporting classifier implementations.

Support of the options in specific classifiers and actions is
implemented in following patches in the series.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index ab87a8b..c510b03 100644 (file)
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -330,6 +330,10 @@ struct tcf_proto_ops {
        int                     (*dump)(struct net*, struct tcf_proto*, void *,
                                        struct sk_buff *skb, struct tcmsg*,
                                        bool);
+       int                     (*terse_dump)(struct net *net,
+                                             struct tcf_proto *tp, void *fh,
+                                             struct sk_buff *skb,
+                                             struct tcmsg *t, bool rtnl_held);
        int                     (*tmplt_dump)(struct sk_buff *skb,
                                              struct net *net,
                                              void *tmplt_priv);

diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 4a8c5b7..073e71e 100644 (file)
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -609,11 +609,17 @@ enum {
        TCA_HW_OFFLOAD,
        TCA_INGRESS_BLOCK,
        TCA_EGRESS_BLOCK,
+       TCA_DUMP_FLAGS,
        __TCA_MAX
 };
 
 #define TCA_MAX (__TCA_MAX - 1)
 
+#define TCA_DUMP_FLAGS_TERSE (1 << 0) /* Means that in dump user gets only basic
+                                      * data necessary to identify the objects
+                                      * (handle, cookie, etc.) and stats.
+                                      */
+
 #define TCA_RTA(r)  ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct tcmsg))))
 #define TCA_PAYLOAD(n) NLMSG_PAYLOAD(n,sizeof(struct tcmsg))
 

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 299b963..cb2c10e 100644 (file)
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1851,7 +1851,7 @@ static int tcf_fill_node(struct net *net, struct sk_buff *skb,
                         struct tcf_proto *tp, struct tcf_block *block,
                         struct Qdisc *q, u32 parent, void *fh,
                         u32 portid, u32 seq, u16 flags, int event,
-                        bool rtnl_held)
+                        bool terse_dump, bool rtnl_held)
 {
        struct tcmsg *tcm;
        struct nlmsghdr  *nlh;
@@ -1878,6 +1878,14 @@ static int tcf_fill_node(struct net *net, struct sk_buff *skb,
                goto nla_put_failure;
        if (!fh) {
                tcm->tcm_handle = 0;
+       } else if (terse_dump) {
+               if (tp->ops->terse_dump) {
+                       if (tp->ops->terse_dump(net, tp, fh, skb, tcm,
+                                               rtnl_held) < 0)
+                               goto nla_put_failure;
+               } else {
+                       goto cls_op_not_supp;
+               }
        } else {
                if (tp->ops->dump &&
                    tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
@@ -1888,6 +1896,7 @@ static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 
 out_nlmsg_trim:
 nla_put_failure:
+cls_op_not_supp:
        nlmsg_trim(skb, b);
        return -1;
 }
@@ -1908,7 +1917,7 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 
        if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
                          n->nlmsg_seq, n->nlmsg_flags, event,
-                         rtnl_held) <= 0) {
+                         false, rtnl_held) <= 0) {
                kfree_skb(skb);
                return -EINVAL;
        }
@@ -1940,7 +1949,7 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 
        if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
                          n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
-                         rtnl_held) <= 0) {
+                         false, rtnl_held) <= 0) {
                NL_SET_ERR_MSG(extack, "Failed to build del event notification");
                kfree_skb(skb);
                return -EINVAL;
@@ -2501,6 +2510,7 @@ struct tcf_dump_args {
        struct tcf_block *block;
        struct Qdisc *q;
        u32 parent;
+       bool terse_dump;
 };
 
 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
@@ -2511,12 +2521,12 @@ static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
        return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
                             n, NETLINK_CB(a->cb->skb).portid,
                             a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
-                            RTM_NEWTFILTER, true);
+                            RTM_NEWTFILTER, a->terse_dump, true);
 }
 
 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
                           struct sk_buff *skb, struct netlink_callback *cb,
-                          long index_start, long *p_index)
+                          long index_start, long *p_index, bool terse)
 {
        struct net *net = sock_net(skb->sk);
        struct tcf_block *block = chain->block;
@@ -2545,7 +2555,7 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
                        if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
                                          NETLINK_CB(cb->skb).portid,
                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
-                                         RTM_NEWTFILTER, true) <= 0)
+                                         RTM_NEWTFILTER, false, true) <= 0)
                                goto errout;
                        cb->args[1] = 1;
                }
@@ -2561,6 +2571,7 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
                arg.w.skip = cb->args[1] - 1;
                arg.w.count = 0;
                arg.w.cookie = cb->args[2];
+               arg.terse_dump = terse;
                tp->ops->walk(tp, &arg.w, true);
                cb->args[2] = arg.w.cookie;
                cb->args[1] = arg.w.count + 1;
@@ -2574,6 +2585,10 @@ errout:
        return false;
 }
 
+static const struct nla_policy tcf_tfilter_dump_policy[TCA_MAX + 1] = {
+       [TCA_DUMP_FLAGS] = NLA_POLICY_BITFIELD32(TCA_DUMP_FLAGS_TERSE),
+};
+
 /* called with RTNL */
 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 {
@@ -2583,6 +2598,7 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
        struct Qdisc *q = NULL;
        struct tcf_block *block;
        struct tcmsg *tcm = nlmsg_data(cb->nlh);
+       bool terse_dump = false;
        long index_start;
        long index;
        u32 parent;
@@ -2592,10 +2608,17 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
                return skb->len;
 
        err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
-                                    NULL, cb->extack);
+                                    tcf_tfilter_dump_policy, cb->extack);
        if (err)
                return err;
 
+       if (tca[TCA_DUMP_FLAGS]) {
+               struct nla_bitfield32 flags =
+                       nla_get_bitfield32(tca[TCA_DUMP_FLAGS]);
+
+               terse_dump = flags.value & TCA_DUMP_FLAGS_TERSE;
+       }
+
        if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
                block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
                if (!block)
@@ -2653,7 +2676,7 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
                    nla_get_u32(tca[TCA_CHAIN]) != chain->index)
                        continue;
                if (!tcf_chain_dump(chain, q, parent, skb, cb,
-                                   index_start, &index)) {
+                                   index_start, &index, terse_dump)) {
                        tcf_chain_put(chain);
                        err = -EMSGSIZE;
                        break;