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3ccd86241b
linux/net/sched/cls_api.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

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/*
* net/sched/cls_api.c Packet classifier API.
*
* 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: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
*
* Changes:
*
* Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
*
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/netlink.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
#if 0 /* control */
#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
#else
#define DPRINTK(format,args...)
#endif
/* The list of all installed classifier types */
static struct tcf_proto_ops *tcf_proto_base;
/* Protects list of registered TC modules. It is pure SMP lock. */
static DEFINE_RWLOCK(cls_mod_lock);
/* Find classifier type by string name */
static struct tcf_proto_ops * tcf_proto_lookup_ops(struct rtattr *kind)
{
struct tcf_proto_ops *t = NULL;
if (kind) {
read_lock(&cls_mod_lock);
for (t = tcf_proto_base; t; t = t->next) {
if (rtattr_strcmp(kind, t->kind) == 0) {
if (!try_module_get(t->owner))
t = NULL;
break;
}
}
read_unlock(&cls_mod_lock);
}
return t;
}
/* Register(unregister) new classifier type */
int register_tcf_proto_ops(struct tcf_proto_ops *ops)
{
struct tcf_proto_ops *t, **tp;
int rc = -EEXIST;
write_lock(&cls_mod_lock);
for (tp = &tcf_proto_base; (t = *tp) != NULL; tp = &t->next)
if (!strcmp(ops->kind, t->kind))
goto out;
ops->next = NULL;
*tp = ops;
rc = 0;
out:
write_unlock(&cls_mod_lock);
return rc;
}
int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
{
struct tcf_proto_ops *t, **tp;
int rc = -ENOENT;
write_lock(&cls_mod_lock);
for (tp = &tcf_proto_base; (t=*tp) != NULL; tp = &t->next)
if (t == ops)
break;
if (!t)
goto out;
*tp = t->next;
rc = 0;
out:
write_unlock(&cls_mod_lock);
return rc;
}
static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n,
struct tcf_proto *tp, unsigned long fh, int event);
/* Select new prio value from the range, managed by kernel. */
static __inline__ u32 tcf_auto_prio(struct tcf_proto *tp)
{
u32 first = TC_H_MAKE(0xC0000000U,0U);
if (tp)
first = tp->prio-1;
return first;
}
/* Add/change/delete/get a filter node */
static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
{
struct rtattr **tca;
struct tcmsg *t;
u32 protocol;
u32 prio;
u32 nprio;
u32 parent;
struct net_device *dev;
struct Qdisc *q;
struct tcf_proto **back, **chain;
struct tcf_proto *tp;
struct tcf_proto_ops *tp_ops;
struct Qdisc_class_ops *cops;
unsigned long cl;
unsigned long fh;
int err;
replay:
tca = arg;
t = NLMSG_DATA(n);
protocol = TC_H_MIN(t->tcm_info);
prio = TC_H_MAJ(t->tcm_info);
nprio = prio;
parent = t->tcm_parent;
cl = 0;
if (prio == 0) {
/* If no priority is given, user wants we allocated it. */
if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE))
return -ENOENT;
prio = TC_H_MAKE(0x80000000U,0U);
}
/* Find head of filter chain. */
/* Find link */
if ((dev = __dev_get_by_index(&init_net, t->tcm_ifindex)) == NULL)
return -ENODEV;
/* Find qdisc */
if (!parent) {
q = dev->qdisc_sleeping;
parent = q->handle;
} else if ((q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent))) == NULL)
return -EINVAL;
/* Is it classful? */
if ((cops = q->ops->cl_ops) == NULL)
return -EINVAL;
/* Do we search for filter, attached to class? */
if (TC_H_MIN(parent)) {
cl = cops->get(q, parent);
if (cl == 0)
return -ENOENT;
}
/* And the last stroke */
chain = cops->tcf_chain(q, cl);
err = -EINVAL;
if (chain == NULL)
goto errout;
/* Check the chain for existence of proto-tcf with this priority */
for (back = chain; (tp=*back) != NULL; back = &tp->next) {
if (tp->prio >= prio) {
if (tp->prio == prio) {
if (!nprio || (tp->protocol != protocol && protocol))
goto errout;
} else
tp = NULL;
break;
}
}
if (tp == NULL) {
/* Proto-tcf does not exist, create new one */
if (tca[TCA_KIND-1] == NULL || !protocol)
goto errout;
err = -ENOENT;
if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE))
goto errout;
/* Create new proto tcf */
err = -ENOBUFS;
if ((tp = kzalloc(sizeof(*tp), GFP_KERNEL)) == NULL)
goto errout;
err = -EINVAL;
tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND-1]);
if (tp_ops == NULL) {
#ifdef CONFIG_KMOD
struct rtattr *kind = tca[TCA_KIND-1];
char name[IFNAMSIZ];
if (kind != NULL &&
rtattr_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
rtnl_unlock();
request_module("cls_%s", name);
rtnl_lock();
tp_ops = tcf_proto_lookup_ops(kind);
/* We dropped the RTNL semaphore in order to
* perform the module load. So, even if we
* succeeded in loading the module we have to
* replay the request. We indicate this using
* -EAGAIN.
*/
if (tp_ops != NULL) {
module_put(tp_ops->owner);
err = -EAGAIN;
}
}
#endif
kfree(tp);
goto errout;
}
tp->ops = tp_ops;
tp->protocol = protocol;
tp->prio = nprio ? : tcf_auto_prio(*back);
tp->q = q;
tp->classify = tp_ops->classify;
tp->classid = parent;
if ((err = tp_ops->init(tp)) != 0) {
module_put(tp_ops->owner);
kfree(tp);
goto errout;
}
qdisc_lock_tree(dev);
tp->next = *back;
*back = tp;
qdisc_unlock_tree(dev);
} else if (tca[TCA_KIND-1] && rtattr_strcmp(tca[TCA_KIND-1], tp->ops->kind))
goto errout;
fh = tp->ops->get(tp, t->tcm_handle);
if (fh == 0) {
if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
qdisc_lock_tree(dev);
*back = tp->next;
qdisc_unlock_tree(dev);
tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER);
tcf_destroy(tp);
err = 0;
goto errout;
}
err = -ENOENT;
if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE))
goto errout;
} else {
switch (n->nlmsg_type) {
case RTM_NEWTFILTER:
err = -EEXIST;
if (n->nlmsg_flags&NLM_F_EXCL)
goto errout;
break;
case RTM_DELTFILTER:
err = tp->ops->delete(tp, fh);
if (err == 0)
tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER);
goto errout;
case RTM_GETTFILTER:
err = tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);
goto errout;
default:
err = -EINVAL;
goto errout;
}
}
err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh);
if (err == 0)
tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);
errout:
if (cl)
cops->put(q, cl);
if (err == -EAGAIN)
/* Replay the request. */
goto replay;
return err;
}
static int
tcf_fill_node(struct sk_buff *skb, struct tcf_proto *tp, unsigned long fh,
u32 pid, u32 seq, u16 flags, int event)
{
struct tcmsg *tcm;
struct nlmsghdr *nlh;
unsigned char *b = skb_tail_pointer(skb);
nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
tcm = NLMSG_DATA(nlh);
tcm->tcm_family = AF_UNSPEC;
tcm->tcm__pad1 = 0;
tcm->tcm__pad1 = 0;
tcm->tcm_ifindex = tp->q->dev->ifindex;
tcm->tcm_parent = tp->classid;
tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
RTA_PUT(skb, TCA_KIND, IFNAMSIZ, tp->ops->kind);
tcm->tcm_handle = fh;
if (RTM_DELTFILTER != event) {
tcm->tcm_handle = 0;
if (tp->ops->dump && tp->ops->dump(tp, fh, skb, tcm) < 0)
goto rtattr_failure;
}
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
return skb->len;
nlmsg_failure:
rtattr_failure:
nlmsg_trim(skb, b);
return -1;
}
static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n,
struct tcf_proto *tp, unsigned long fh, int event)
{
struct sk_buff *skb;
u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return -ENOBUFS;
if (tcf_fill_node(skb, tp, fh, pid, n->nlmsg_seq, 0, event) <= 0) {
kfree_skb(skb);
return -EINVAL;
}
return rtnetlink_send(skb, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
}
struct tcf_dump_args
{
struct tcf_walker w;
struct sk_buff *skb;
struct netlink_callback *cb;
};
static int tcf_node_dump(struct tcf_proto *tp, unsigned long n, struct tcf_walker *arg)
{
struct tcf_dump_args *a = (void*)arg;
return tcf_fill_node(a->skb, tp, n, NETLINK_CB(a->cb->skb).pid,
a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER);
}
static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
{
int t;
int s_t;
struct net_device *dev;
struct Qdisc *q;
struct tcf_proto *tp, **chain;
struct tcmsg *tcm = (struct tcmsg*)NLMSG_DATA(cb->nlh);
unsigned long cl = 0;
struct Qdisc_class_ops *cops;
struct tcf_dump_args arg;
if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
return skb->len;
if ((dev = dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL)
return skb->len;
if (!tcm->tcm_parent)
q = dev->qdisc_sleeping;
else
q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
if (!q)
goto out;
if ((cops = q->ops->cl_ops) == NULL)
goto errout;
if (TC_H_MIN(tcm->tcm_parent)) {
cl = cops->get(q, tcm->tcm_parent);
if (cl == 0)
goto errout;
}
chain = cops->tcf_chain(q, cl);
if (chain == NULL)
goto errout;
s_t = cb->args[0];
for (tp=*chain, t=0; tp; tp = tp->next, t++) {
if (t < s_t) continue;
if (TC_H_MAJ(tcm->tcm_info) &&
TC_H_MAJ(tcm->tcm_info) != tp->prio)
continue;
if (TC_H_MIN(tcm->tcm_info) &&
TC_H_MIN(tcm->tcm_info) != tp->protocol)
continue;
if (t > s_t)
memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
if (cb->args[1] == 0) {
if (tcf_fill_node(skb, tp, 0, NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER) <= 0) {
break;
}
cb->args[1] = 1;
}
if (tp->ops->walk == NULL)
continue;
arg.w.fn = tcf_node_dump;
arg.skb = skb;
arg.cb = cb;
arg.w.stop = 0;
arg.w.skip = cb->args[1]-1;
arg.w.count = 0;
tp->ops->walk(tp, &arg.w);
cb->args[1] = arg.w.count+1;
if (arg.w.stop)
break;
}
cb->args[0] = t;
errout:
if (cl)
cops->put(q, cl);
out:
dev_put(dev);
return skb->len;
}
void
tcf_exts_destroy(struct tcf_proto *tp, struct tcf_exts *exts)
{
#ifdef CONFIG_NET_CLS_ACT
if (exts->action) {
tcf_action_destroy(exts->action, TCA_ACT_UNBIND);
exts->action = NULL;
}
#endif
}
int
tcf_exts_validate(struct tcf_proto *tp, struct rtattr **tb,
struct rtattr *rate_tlv, struct tcf_exts *exts,
struct tcf_ext_map *map)
{
memset(exts, 0, sizeof(*exts));
#ifdef CONFIG_NET_CLS_ACT
{
int err;
struct tc_action *act;
if (map->police && tb[map->police-1]) {
act = tcf_action_init_1(tb[map->police-1], rate_tlv, "police",
TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err);
if (act == NULL)
return err;
act->type = TCA_OLD_COMPAT;
exts->action = act;
} else if (map->action && tb[map->action-1]) {
act = tcf_action_init(tb[map->action-1], rate_tlv, NULL,
TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err);
if (act == NULL)
return err;
exts->action = act;
}
}
#else
if ((map->action && tb[map->action-1]) ||
(map->police && tb[map->police-1]))
return -EOPNOTSUPP;
#endif
return 0;
}
void
tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst,
struct tcf_exts *src)
{
#ifdef CONFIG_NET_CLS_ACT
if (src->action) {
struct tc_action *act;
tcf_tree_lock(tp);
act = xchg(&dst->action, src->action);
tcf_tree_unlock(tp);
if (act)
tcf_action_destroy(act, TCA_ACT_UNBIND);
}
#endif
}
int
tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts,
struct tcf_ext_map *map)
{
#ifdef CONFIG_NET_CLS_ACT
if (map->action && exts->action) {
/*
* again for backward compatible mode - we want
* to work with both old and new modes of entering
* tc data even if iproute2 was newer - jhs
*/
struct rtattr *p_rta = (struct rtattr *)skb_tail_pointer(skb);
if (exts->action->type != TCA_OLD_COMPAT) {
RTA_PUT(skb, map->action, 0, NULL);
if (tcf_action_dump(skb, exts->action, 0, 0) < 0)
goto rtattr_failure;
p_rta->rta_len = skb_tail_pointer(skb) - (u8 *)p_rta;
} else if (map->police) {
RTA_PUT(skb, map->police, 0, NULL);
if (tcf_action_dump_old(skb, exts->action, 0, 0) < 0)
goto rtattr_failure;
p_rta->rta_len = skb_tail_pointer(skb) - (u8 *)p_rta;
}
}
#endif
return 0;
rtattr_failure: __attribute__ ((unused))
return -1;
}
int
tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts,
struct tcf_ext_map *map)
{
#ifdef CONFIG_NET_CLS_ACT
if (exts->action)
if (tcf_action_copy_stats(skb, exts->action, 1) < 0)
goto rtattr_failure;
#endif
return 0;
rtattr_failure: __attribute__ ((unused))
return -1;
}
static int __init tc_filter_init(void)
{
rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL);
rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL);
rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
tc_dump_tfilter);
return 0;
}
subsys_initcall(tc_filter_init);
EXPORT_SYMBOL(register_tcf_proto_ops);
EXPORT_SYMBOL(unregister_tcf_proto_ops);
EXPORT_SYMBOL(tcf_exts_validate);
EXPORT_SYMBOL(tcf_exts_destroy);
EXPORT_SYMBOL(tcf_exts_change);
EXPORT_SYMBOL(tcf_exts_dump);
EXPORT_SYMBOL(tcf_exts_dump_stats);
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