| /* |
| * 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; |
| union { |
| struct work_struct work; |
| 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 = task_get_classid(skb); |
| |
| 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 void *cls_cgroup_get(struct tcf_proto *tp, u32 handle) |
| { |
| return NULL; |
| } |
| |
| 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(struct cls_cgroup_head *head) |
| { |
| tcf_exts_destroy(&head->exts); |
| tcf_em_tree_destroy(&head->ematches); |
| tcf_exts_put_net(&head->exts); |
| kfree(head); |
| } |
| |
| static void cls_cgroup_destroy_work(struct work_struct *work) |
| { |
| struct cls_cgroup_head *head = container_of(work, |
| struct cls_cgroup_head, |
| work); |
| rtnl_lock(); |
| __cls_cgroup_destroy(head); |
| rtnl_unlock(); |
| } |
| |
| static void cls_cgroup_destroy_rcu(struct rcu_head *root) |
| { |
| struct cls_cgroup_head *head = container_of(root, |
| struct cls_cgroup_head, |
| rcu); |
| |
| INIT_WORK(&head->work, cls_cgroup_destroy_work); |
| tcf_queue_work(&head->work); |
| } |
| |
| 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, |
| void **arg, bool ovr) |
| { |
| struct nlattr *tb[TCA_CGROUP_MAX + 1]; |
| struct cls_cgroup_head *head = rtnl_dereference(tp->root); |
| struct cls_cgroup_head *new; |
| 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; |
| |
| err = tcf_exts_init(&new->exts, TCA_CGROUP_ACT, TCA_CGROUP_POLICE); |
| if (err < 0) |
| goto errout; |
| new->handle = handle; |
| new->tp = tp; |
| err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS], |
| cgroup_policy, NULL); |
| if (err < 0) |
| goto errout; |
| |
| err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &new->exts, ovr); |
| if (err < 0) |
| goto errout; |
| |
| err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &new->ematches); |
| if (err < 0) |
| goto errout; |
| |
| rcu_assign_pointer(tp->root, new); |
| if (head) { |
| tcf_exts_get_net(&head->exts); |
| call_rcu(&head->rcu, cls_cgroup_destroy_rcu); |
| } |
| return 0; |
| errout: |
| tcf_exts_destroy(&new->exts); |
| kfree(new); |
| return err; |
| } |
| |
| static void cls_cgroup_destroy(struct tcf_proto *tp) |
| { |
| struct cls_cgroup_head *head = rtnl_dereference(tp->root); |
| |
| /* Head can still be NULL due to cls_cgroup_init(). */ |
| if (head) { |
| if (tcf_exts_get_net(&head->exts)) |
| call_rcu(&head->rcu, cls_cgroup_destroy_rcu); |
| else |
| __cls_cgroup_destroy(head); |
| } |
| } |
| |
| static int cls_cgroup_delete(struct tcf_proto *tp, void *arg, bool *last) |
| { |
| 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, head, arg) < 0) { |
| arg->stop = 1; |
| return; |
| } |
| skip: |
| arg->count++; |
| } |
| |
| static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, void *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"); |