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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /net/sched/cls_cgroup.c
Initial import
Diffstat (limited to 'net/sched/cls_cgroup.c')
-rw-r--r--net/sched/cls_cgroup.c233
1 files changed, 233 insertions, 0 deletions
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
new file mode 100644
index 000000000..ea611b216
--- /dev/null
+++ b/net/sched/cls_cgroup.c
@@ -0,0 +1,233 @@
+/*
+ * net/sched/cls_cgroup.c Control Group Classifier
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Authors: Thomas Graf <tgraf@suug.ch>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/skbuff.h>
+#include <linux/rcupdate.h>
+#include <net/rtnetlink.h>
+#include <net/pkt_cls.h>
+#include <net/sock.h>
+#include <net/cls_cgroup.h>
+
+struct cls_cgroup_head {
+ u32 handle;
+ struct tcf_exts exts;
+ struct tcf_ematch_tree ematches;
+ struct tcf_proto *tp;
+ struct rcu_head rcu;
+};
+
+static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp,
+ struct tcf_result *res)
+{
+ struct cls_cgroup_head *head = rcu_dereference_bh(tp->root);
+ u32 classid;
+
+ classid = task_cls_state(current)->classid;
+
+ /*
+ * Due to the nature of the classifier it is required to ignore all
+ * packets originating from softirq context as accessing `current'
+ * would lead to false results.
+ *
+ * This test assumes that all callers of dev_queue_xmit() explicitely
+ * disable bh. Knowing this, it is possible to detect softirq based
+ * calls by looking at the number of nested bh disable calls because
+ * softirqs always disables bh.
+ */
+ if (in_serving_softirq()) {
+ /* If there is an sk_classid we'll use that. */
+ if (!skb->sk)
+ return -1;
+ classid = skb->sk->sk_classid;
+ }
+
+ if (!classid)
+ return -1;
+
+ if (!tcf_em_tree_match(skb, &head->ematches, NULL))
+ return -1;
+
+ res->classid = classid;
+ res->class = 0;
+ return tcf_exts_exec(skb, &head->exts, res);
+}
+
+static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle)
+{
+ return 0UL;
+}
+
+static int cls_cgroup_init(struct tcf_proto *tp)
+{
+ return 0;
+}
+
+static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
+ [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
+};
+
+static void cls_cgroup_destroy_rcu(struct rcu_head *root)
+{
+ struct cls_cgroup_head *head = container_of(root,
+ struct cls_cgroup_head,
+ rcu);
+
+ tcf_exts_destroy(&head->exts);
+ tcf_em_tree_destroy(&head->ematches);
+ kfree(head);
+}
+
+static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
+ struct tcf_proto *tp, unsigned long base,
+ u32 handle, struct nlattr **tca,
+ unsigned long *arg, bool ovr)
+{
+ struct nlattr *tb[TCA_CGROUP_MAX + 1];
+ struct cls_cgroup_head *head = rtnl_dereference(tp->root);
+ struct cls_cgroup_head *new;
+ struct tcf_ematch_tree t;
+ struct tcf_exts e;
+ int err;
+
+ if (!tca[TCA_OPTIONS])
+ return -EINVAL;
+
+ if (!head && !handle)
+ return -EINVAL;
+
+ if (head && handle != head->handle)
+ return -ENOENT;
+
+ new = kzalloc(sizeof(*head), GFP_KERNEL);
+ if (!new)
+ return -ENOBUFS;
+
+ tcf_exts_init(&new->exts, TCA_CGROUP_ACT, TCA_CGROUP_POLICE);
+ new->handle = handle;
+ new->tp = tp;
+ err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
+ cgroup_policy);
+ if (err < 0)
+ goto errout;
+
+ tcf_exts_init(&e, TCA_CGROUP_ACT, TCA_CGROUP_POLICE);
+ err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr);
+ if (err < 0)
+ goto errout;
+
+ err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t);
+ if (err < 0) {
+ tcf_exts_destroy(&e);
+ goto errout;
+ }
+
+ tcf_exts_change(tp, &new->exts, &e);
+ tcf_em_tree_change(tp, &new->ematches, &t);
+
+ rcu_assign_pointer(tp->root, new);
+ if (head)
+ call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
+ return 0;
+errout:
+ kfree(new);
+ return err;
+}
+
+static bool cls_cgroup_destroy(struct tcf_proto *tp, bool force)
+{
+ struct cls_cgroup_head *head = rtnl_dereference(tp->root);
+
+ if (!force)
+ return false;
+
+ if (head) {
+ RCU_INIT_POINTER(tp->root, NULL);
+ call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
+ }
+ return true;
+}
+
+static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg)
+{
+ return -EOPNOTSUPP;
+}
+
+static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+{
+ struct cls_cgroup_head *head = rtnl_dereference(tp->root);
+
+ if (arg->count < arg->skip)
+ goto skip;
+
+ if (arg->fn(tp, (unsigned long) head, arg) < 0) {
+ arg->stop = 1;
+ return;
+ }
+skip:
+ arg->count++;
+}
+
+static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
+ struct sk_buff *skb, struct tcmsg *t)
+{
+ struct cls_cgroup_head *head = rtnl_dereference(tp->root);
+ struct nlattr *nest;
+
+ t->tcm_handle = head->handle;
+
+ nest = nla_nest_start(skb, TCA_OPTIONS);
+ if (nest == NULL)
+ goto nla_put_failure;
+
+ if (tcf_exts_dump(skb, &head->exts) < 0 ||
+ tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest);
+
+ if (tcf_exts_dump_stats(skb, &head->exts) < 0)
+ goto nla_put_failure;
+
+ return skb->len;
+
+nla_put_failure:
+ nla_nest_cancel(skb, nest);
+ return -1;
+}
+
+static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
+ .kind = "cgroup",
+ .init = cls_cgroup_init,
+ .change = cls_cgroup_change,
+ .classify = cls_cgroup_classify,
+ .destroy = cls_cgroup_destroy,
+ .get = cls_cgroup_get,
+ .delete = cls_cgroup_delete,
+ .walk = cls_cgroup_walk,
+ .dump = cls_cgroup_dump,
+ .owner = THIS_MODULE,
+};
+
+static int __init init_cgroup_cls(void)
+{
+ return register_tcf_proto_ops(&cls_cgroup_ops);
+}
+
+static void __exit exit_cgroup_cls(void)
+{
+ unregister_tcf_proto_ops(&cls_cgroup_ops);
+}
+
+module_init(init_cgroup_cls);
+module_exit(exit_cgroup_cls);
+MODULE_LICENSE("GPL");