linux-stable/net/sched/cls_cgroup.c
Benjamin LaHaise c1b52739e4 pkt_sched: namespace aware act_mirred
Eric Dumazet pointed out that act_mirred needs to find the current net_ns,
and struct net pointer is not provided in the call chain.  His original
patch made use of current->nsproxy->net_ns to find the network namespace,
but this fails to work correctly for userspace code that makes use of
netlink sockets in different network namespaces.  Instead, pass the
"struct net *" down along the call chain to where it is needed.

This version removes the ifb changes as Eric has submitted that patch
separately, but is otherwise identical to the previous version.

Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Tested-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-14 15:09:36 -05:00

332 lines
7.2 KiB
C

/*
* 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/types.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/cgroup.h>
#include <linux/rcupdate.h>
#include <linux/fdtable.h>
#include <net/rtnetlink.h>
#include <net/pkt_cls.h>
#include <net/sock.h>
#include <net/cls_cgroup.h>
static inline struct cgroup_cls_state *cgrp_cls_state(struct cgroup *cgrp)
{
return container_of(cgroup_subsys_state(cgrp, net_cls_subsys_id),
struct cgroup_cls_state, css);
}
static inline struct cgroup_cls_state *task_cls_state(struct task_struct *p)
{
return container_of(task_subsys_state(p, net_cls_subsys_id),
struct cgroup_cls_state, css);
}
static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp)
{
struct cgroup_cls_state *cs;
cs = kzalloc(sizeof(*cs), GFP_KERNEL);
if (!cs)
return ERR_PTR(-ENOMEM);
return &cs->css;
}
static int cgrp_css_online(struct cgroup *cgrp)
{
if (cgrp->parent)
cgrp_cls_state(cgrp)->classid =
cgrp_cls_state(cgrp->parent)->classid;
return 0;
}
static void cgrp_css_free(struct cgroup *cgrp)
{
kfree(cgrp_cls_state(cgrp));
}
static int update_classid(const void *v, struct file *file, unsigned n)
{
int err;
struct socket *sock = sock_from_file(file, &err);
if (sock)
sock->sk->sk_classid = (u32)(unsigned long)v;
return 0;
}
static void cgrp_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
{
struct task_struct *p;
void *v;
cgroup_taskset_for_each(p, cgrp, tset) {
task_lock(p);
v = (void *)(unsigned long)task_cls_classid(p);
iterate_fd(p->files, 0, update_classid, v);
task_unlock(p);
}
}
static u64 read_classid(struct cgroup *cgrp, struct cftype *cft)
{
return cgrp_cls_state(cgrp)->classid;
}
static int write_classid(struct cgroup *cgrp, struct cftype *cft, u64 value)
{
cgrp_cls_state(cgrp)->classid = (u32) value;
return 0;
}
static struct cftype ss_files[] = {
{
.name = "classid",
.read_u64 = read_classid,
.write_u64 = write_classid,
},
{ } /* terminate */
};
struct cgroup_subsys net_cls_subsys = {
.name = "net_cls",
.css_alloc = cgrp_css_alloc,
.css_online = cgrp_css_online,
.css_free = cgrp_css_free,
.attach = cgrp_attach,
.subsys_id = net_cls_subsys_id,
.base_cftypes = ss_files,
.module = THIS_MODULE,
};
struct cls_cgroup_head {
u32 handle;
struct tcf_exts exts;
struct tcf_ematch_tree ematches;
};
static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp,
struct tcf_result *res)
{
struct cls_cgroup_head *head = tp->root;
u32 classid;
rcu_read_lock();
classid = task_cls_state(current)->classid;
rcu_read_unlock();
/*
* 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 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 net *net, struct sk_buff *in_skb,
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 (!tca[TCA_OPTIONS])
return -EINVAL;
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(net, 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 = tp->root;
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)
{
int ret;
ret = cgroup_load_subsys(&net_cls_subsys);
if (ret)
goto out;
ret = register_tcf_proto_ops(&cls_cgroup_ops);
if (ret)
cgroup_unload_subsys(&net_cls_subsys);
out:
return ret;
}
static void __exit exit_cgroup_cls(void)
{
unregister_tcf_proto_ops(&cls_cgroup_ops);
cgroup_unload_subsys(&net_cls_subsys);
}
module_init(init_cgroup_cls);
module_exit(exit_cgroup_cls);
MODULE_LICENSE("GPL");