linux/net/sched/act_mirred.c
Eric W. Biederman 881d966b48 [NET]: Make the device list and device lookups per namespace.
This patch makes most of the generic device layer network
namespace safe.  This patch makes dev_base_head a
network namespace variable, and then it picks up
a few associated variables.  The functions:
dev_getbyhwaddr
dev_getfirsthwbytype
dev_get_by_flags
dev_get_by_name
__dev_get_by_name
dev_get_by_index
__dev_get_by_index
dev_ioctl
dev_ethtool
dev_load
wireless_process_ioctl

were modified to take a network namespace argument, and
deal with it.

vlan_ioctl_set and brioctl_set were modified so their
hooks will receive a network namespace argument.

So basically anthing in the core of the network stack that was
affected to by the change of dev_base was modified to handle
multiple network namespaces.  The rest of the network stack was
simply modified to explicitly use &init_net the initial network
namespace.  This can be fixed when those components of the network
stack are modified to handle multiple network namespaces.

For now the ifindex generator is left global.

Fundametally ifindex numbers are per namespace, or else
we will have corner case problems with migration when
we get that far.

At the same time there are assumptions in the network stack
that the ifindex of a network device won't change.  Making
the ifindex number global seems a good compromise until
the network stack can cope with ifindex changes when
you change namespaces, and the like.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:49:10 -07:00

252 lines
6 KiB
C

/*
* net/sched/mirred.c packet mirroring and redirect actions
*
* 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: Jamal Hadi Salim (2002-4)
*
* TODO: Add ingress support (and socket redirect support)
*
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/module.h>
#include <linux/init.h>
#include <net/net_namespace.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <linux/tc_act/tc_mirred.h>
#include <net/tc_act/tc_mirred.h>
#include <linux/if_arp.h>
#define MIRRED_TAB_MASK 7
static struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1];
static u32 mirred_idx_gen;
static DEFINE_RWLOCK(mirred_lock);
static struct tcf_hashinfo mirred_hash_info = {
.htab = tcf_mirred_ht,
.hmask = MIRRED_TAB_MASK,
.lock = &mirred_lock,
};
static inline int tcf_mirred_release(struct tcf_mirred *m, int bind)
{
if (m) {
if (bind)
m->tcf_bindcnt--;
m->tcf_refcnt--;
if(!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
dev_put(m->tcfm_dev);
tcf_hash_destroy(&m->common, &mirred_hash_info);
return 1;
}
}
return 0;
}
static int tcf_mirred_init(struct rtattr *rta, struct rtattr *est,
struct tc_action *a, int ovr, int bind)
{
struct rtattr *tb[TCA_MIRRED_MAX];
struct tc_mirred *parm;
struct tcf_mirred *m;
struct tcf_common *pc;
struct net_device *dev = NULL;
int ret = 0;
int ok_push = 0;
if (rta == NULL || rtattr_parse_nested(tb, TCA_MIRRED_MAX, rta) < 0)
return -EINVAL;
if (tb[TCA_MIRRED_PARMS-1] == NULL ||
RTA_PAYLOAD(tb[TCA_MIRRED_PARMS-1]) < sizeof(*parm))
return -EINVAL;
parm = RTA_DATA(tb[TCA_MIRRED_PARMS-1]);
if (parm->ifindex) {
dev = __dev_get_by_index(&init_net, parm->ifindex);
if (dev == NULL)
return -ENODEV;
switch (dev->type) {
case ARPHRD_TUNNEL:
case ARPHRD_TUNNEL6:
case ARPHRD_SIT:
case ARPHRD_IPGRE:
case ARPHRD_VOID:
case ARPHRD_NONE:
ok_push = 0;
break;
default:
ok_push = 1;
break;
}
}
pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
if (!pc) {
if (!parm->ifindex)
return -EINVAL;
pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
&mirred_idx_gen, &mirred_hash_info);
if (unlikely(!pc))
return -ENOMEM;
ret = ACT_P_CREATED;
} else {
if (!ovr) {
tcf_mirred_release(to_mirred(pc), bind);
return -EEXIST;
}
}
m = to_mirred(pc);
spin_lock_bh(&m->tcf_lock);
m->tcf_action = parm->action;
m->tcfm_eaction = parm->eaction;
if (parm->ifindex) {
m->tcfm_ifindex = parm->ifindex;
if (ret != ACT_P_CREATED)
dev_put(m->tcfm_dev);
m->tcfm_dev = dev;
dev_hold(dev);
m->tcfm_ok_push = ok_push;
}
spin_unlock_bh(&m->tcf_lock);
if (ret == ACT_P_CREATED)
tcf_hash_insert(pc, &mirred_hash_info);
return ret;
}
static int tcf_mirred_cleanup(struct tc_action *a, int bind)
{
struct tcf_mirred *m = a->priv;
if (m)
return tcf_mirred_release(m, bind);
return 0;
}
static int tcf_mirred(struct sk_buff *skb, struct tc_action *a,
struct tcf_result *res)
{
struct tcf_mirred *m = a->priv;
struct net_device *dev;
struct sk_buff *skb2 = NULL;
u32 at = G_TC_AT(skb->tc_verd);
spin_lock(&m->tcf_lock);
dev = m->tcfm_dev;
m->tcf_tm.lastuse = jiffies;
if (!(dev->flags&IFF_UP) ) {
if (net_ratelimit())
printk("mirred to Houston: device %s is gone!\n",
dev->name);
bad_mirred:
if (skb2 != NULL)
kfree_skb(skb2);
m->tcf_qstats.overlimits++;
m->tcf_bstats.bytes += skb->len;
m->tcf_bstats.packets++;
spin_unlock(&m->tcf_lock);
/* should we be asking for packet to be dropped?
* may make sense for redirect case only
*/
return TC_ACT_SHOT;
}
skb2 = skb_clone(skb, GFP_ATOMIC);
if (skb2 == NULL)
goto bad_mirred;
if (m->tcfm_eaction != TCA_EGRESS_MIRROR &&
m->tcfm_eaction != TCA_EGRESS_REDIR) {
if (net_ratelimit())
printk("tcf_mirred unknown action %d\n",
m->tcfm_eaction);
goto bad_mirred;
}
m->tcf_bstats.bytes += skb2->len;
m->tcf_bstats.packets++;
if (!(at & AT_EGRESS))
if (m->tcfm_ok_push)
skb_push(skb2, skb2->dev->hard_header_len);
/* mirror is always swallowed */
if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
skb2->dev = dev;
skb2->iif = skb->dev->ifindex;
dev_queue_xmit(skb2);
spin_unlock(&m->tcf_lock);
return m->tcf_action;
}
static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_mirred *m = a->priv;
struct tc_mirred opt;
struct tcf_t t;
opt.index = m->tcf_index;
opt.action = m->tcf_action;
opt.refcnt = m->tcf_refcnt - ref;
opt.bindcnt = m->tcf_bindcnt - bind;
opt.eaction = m->tcfm_eaction;
opt.ifindex = m->tcfm_ifindex;
RTA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
RTA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
return skb->len;
rtattr_failure:
nlmsg_trim(skb, b);
return -1;
}
static struct tc_action_ops act_mirred_ops = {
.kind = "mirred",
.hinfo = &mirred_hash_info,
.type = TCA_ACT_MIRRED,
.capab = TCA_CAP_NONE,
.owner = THIS_MODULE,
.act = tcf_mirred,
.dump = tcf_mirred_dump,
.cleanup = tcf_mirred_cleanup,
.lookup = tcf_hash_search,
.init = tcf_mirred_init,
.walk = tcf_generic_walker
};
MODULE_AUTHOR("Jamal Hadi Salim(2002)");
MODULE_DESCRIPTION("Device Mirror/redirect actions");
MODULE_LICENSE("GPL");
static int __init mirred_init_module(void)
{
printk("Mirror/redirect action on\n");
return tcf_register_action(&act_mirred_ops);
}
static void __exit mirred_cleanup_module(void)
{
tcf_unregister_action(&act_mirred_ops);
}
module_init(mirred_init_module);
module_exit(mirred_cleanup_module);