diff options
Diffstat (limited to 'kernel/net/sched/cls_cgroup.c')
| -rw-r--r-- | kernel/net/sched/cls_cgroup.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/kernel/net/sched/cls_cgroup.c b/kernel/net/sched/cls_cgroup.c new file mode 100644 index 000000000..ea611b216 --- /dev/null +++ b/kernel/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"); |