--- /dev/null
+/*
+ * 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/types.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/skbuff.h>
+#include <linux/cgroup.h>
+#include <net/rtnetlink.h>
+#include <net/pkt_cls.h>
+
+struct cgroup_cls_state
+{
+ struct cgroup_subsys_state css;
+ u32 classid;
+};
+
+static inline struct cgroup_cls_state *net_cls_state(struct cgroup *cgrp)
+{
+ return (struct cgroup_cls_state *)
+ cgroup_subsys_state(cgrp, net_cls_subsys_id);
+}
+
+static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
+ struct cgroup *cgrp)
+{
+ struct cgroup_cls_state *cs;
+
+ if (!(cs = kzalloc(sizeof(*cs), GFP_KERNEL)))
+ return ERR_PTR(-ENOMEM);
+
+ if (cgrp->parent)
+ cs->classid = net_cls_state(cgrp->parent)->classid;
+
+ return &cs->css;
+}
+
+static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
+{
+ kfree(ss);
+}
+
+static u64 read_classid(struct cgroup *cgrp, struct cftype *cft)
+{
+ return net_cls_state(cgrp)->classid;
+}
+
+static int write_classid(struct cgroup *cgrp, struct cftype *cft, u64 value)
+{
+ if (!cgroup_lock_live_group(cgrp))
+ return -ENODEV;
+
+ net_cls_state(cgrp)->classid = (u32) value;
+
+ cgroup_unlock();
+
+ return 0;
+}
+
+static struct cftype ss_files[] = {
+ {
+ .name = "classid",
+ .read_u64 = read_classid,
+ .write_u64 = write_classid,
+ },
+};
+
+static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
+{
+ return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
+}
+
+struct cgroup_subsys net_cls_subsys = {
+ .name = "net_cls",
+ .create = cgrp_create,
+ .destroy = cgrp_destroy,
+ .populate = cgrp_populate,
+ .subsys_id = net_cls_subsys_id,
+};
+
+struct cls_cgroup_head
+{
+ u32 handle;
+ struct tcf_exts exts;
+ struct tcf_ematch_tree ematches;
+};
+
+static int cls_cgroup_classify(struct sk_buff *skb, struct tcf_proto *tp,
+ struct tcf_result *res)
+{
+ struct cls_cgroup_head *head = tp->root;
+ struct cgroup_cls_state *cs;
+ int ret = 0;
+
+ /*
+ * 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 (softirq_count() != SOFTIRQ_OFFSET)
+ return -1;
+
+ rcu_read_lock();
+ cs = (struct cgroup_cls_state *) task_subsys_state(current,
+ net_cls_subsys_id);
+ if (cs->classid && tcf_em_tree_match(skb, &head->ematches, NULL)) {
+ res->classid = cs->classid;
+ res->class = 0;
+ ret = tcf_exts_exec(skb, &head->exts, res);
+ } else
+ ret = -1;
+
+ rcu_read_unlock();
+
+ return ret;
+}
+
+static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle)
+{
+ return 0UL;
+}
+
+static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f)
+{
+}
+
+static int cls_cgroup_init(struct tcf_proto *tp)
+{
+ return 0;
+}
+
+static const struct tcf_ext_map cgroup_ext_map = {
+ .action = TCA_CGROUP_ACT,
+ .police = TCA_CGROUP_POLICE,
+};
+
+static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
+ [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
+};
+
+static int cls_cgroup_change(struct tcf_proto *tp, unsigned long base,
+ u32 handle, struct nlattr **tca,
+ unsigned long *arg)
+{
+ struct nlattr *tb[TCA_CGROUP_MAX+1];
+ struct cls_cgroup_head *head = tp->root;
+ struct tcf_ematch_tree t;
+ struct tcf_exts e;
+ int err;
+
+ if (head == NULL) {
+ if (!handle)
+ return -EINVAL;
+
+ head = kzalloc(sizeof(*head), GFP_KERNEL);
+ if (head == NULL)
+ return -ENOBUFS;
+
+ head->handle = handle;
+
+ tcf_tree_lock(tp);
+ tp->root = head;
+ tcf_tree_unlock(tp);
+ }
+
+ if (handle != head->handle)
+ return -ENOENT;
+
+ err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
+ cgroup_policy);
+ if (err < 0)
+ return err;
+
+ err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &cgroup_ext_map);
+ if (err < 0)
+ return err;
+
+ err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t);
+ if (err < 0)
+ return err;
+
+ tcf_exts_change(tp, &head->exts, &e);
+ tcf_em_tree_change(tp, &head->ematches, &t);
+
+ return 0;
+}
+
+static void cls_cgroup_destroy(struct tcf_proto *tp)
+{
+ struct cls_cgroup_head *head;
+
+ head = (struct cls_cgroup_head *)xchg(&tp->root, NULL);
+
+ if (head) {
+ tcf_exts_destroy(tp, &head->exts);
+ tcf_em_tree_destroy(tp, &head->ematches);
+ kfree(head);
+ }
+}
+
+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 = 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 tcf_proto *tp, unsigned long fh,
+ struct sk_buff *skb, struct tcmsg *t)
+{
+ struct cls_cgroup_head *head = tp->root;
+ unsigned char *b = skb_tail_pointer(skb);
+ 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, &cgroup_ext_map) < 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, &cgroup_ext_map) < 0)
+ goto nla_put_failure;
+
+ return skb->len;
+
+nla_put_failure:
+ nlmsg_trim(skb, b);
+ 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,
+ .put = cls_cgroup_put,
+ .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");
projects / openwrt / staging / blogic.git / commitdiff