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linux/net/sched/act_api.c
Daniel Borkmann 28e6b67f0b net: sched: fix refcount imbalance in actions 
Since commit 55334a5db5 ("net_sched: act: refuse to remove bound action
outside"), we end up with a wrong reference count for a tc action.

Test case 1:

  FOO="1,6 0 0 4294967295,"
  BAR="1,6 0 0 4294967294,"
  tc filter add dev foo parent 1: bpf bytecode "$FOO" flowid 1:1 \
     action bpf bytecode "$FOO"
  tc actions show action bpf
    action order 0: bpf bytecode '1,6 0 0 4294967295' default-action pipe
    index 1 ref 1 bind 1
  tc actions replace action bpf bytecode "$BAR" index 1
  tc actions show action bpf
    action order 0: bpf bytecode '1,6 0 0 4294967294' default-action pipe
    index 1 ref 2 bind 1
  tc actions replace action bpf bytecode "$FOO" index 1
  tc actions show action bpf
    action order 0: bpf bytecode '1,6 0 0 4294967295' default-action pipe
    index 1 ref 3 bind 1

Test case 2:

  FOO="1,6 0 0 4294967295,"
  tc filter add dev foo parent 1: bpf bytecode "$FOO" flowid 1:1 action ok
  tc actions show action gact
    action order 0: gact action pass
    random type none pass val 0
     index 1 ref 1 bind 1
  tc actions add action drop index 1
    RTNETLINK answers: File exists [...]
  tc actions show action gact
    action order 0: gact action pass
     random type none pass val 0
     index 1 ref 2 bind 1
  tc actions add action drop index 1
    RTNETLINK answers: File exists [...]
  tc actions show action gact
    action order 0: gact action pass
     random type none pass val 0
     index 1 ref 3 bind 1

What happens is that in tcf_hash_check(), we check tcf_common for a given
index and increase tcfc_refcnt and conditionally tcfc_bindcnt when we've
found an existing action. Now there are the following cases:

  1) We do a late binding of an action. In that case, we leave the
     tcfc_refcnt/tcfc_bindcnt increased and are done with the ->init()
     handler. This is correctly handeled.

  2) We replace the given action, or we try to add one without replacing
     and find out that the action at a specific index already exists
     (thus, we go out with error in that case).

In case of 2), we have to undo the reference count increase from
tcf_hash_check() in the tcf_hash_check() function. Currently, we fail to
do so because of the 'tcfc_bindcnt > 0' check which bails out early with
an -EPERM error.

Now, while commit 55334a5db5 prevents 'tc actions del action ...' on an
already classifier-bound action to drop the reference count (which could
then become negative, wrap around etc), this restriction only accounts for
invocations outside a specific action's ->init() handler.

One possible solution would be to add a flag thus we possibly trigger
the -EPERM ony in situations where it is indeed relevant.

After the patch, above test cases have correct reference count again.

Fixes: 55334a5db5 ("net_sched: act: refuse to remove bound action outside")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 14:20:39 -07:00

1091 lines
23 KiB
C
Raw Blame History

/*
* net/sched/act_api.c Packet action 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.
*
* Author: Jamal Hadi Salim
*
*
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/err.h>
#include <linux/module.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/sch_generic.h>
#include <net/act_api.h>
#include <net/netlink.h>
void tcf_hash_destroy(struct tc_action *a)
{
struct tcf_common *p = a->priv;
struct tcf_hashinfo *hinfo = a->ops->hinfo;
spin_lock_bh(&hinfo->lock);
hlist_del(&p->tcfc_head);
spin_unlock_bh(&hinfo->lock);
gen_kill_estimator(&p->tcfc_bstats,
&p->tcfc_rate_est);
/*
* gen_estimator est_timer() might access p->tcfc_lock
* or bstats, wait a RCU grace period before freeing p
*/
kfree_rcu(p, tcfc_rcu);
}
EXPORT_SYMBOL(tcf_hash_destroy);
int __tcf_hash_release(struct tc_action *a, bool bind, bool strict)
{
struct tcf_common *p = a->priv;
int ret = 0;
if (p) {
if (bind)
p->tcfc_bindcnt--;
else if (strict && p->tcfc_bindcnt > 0)
return -EPERM;
p->tcfc_refcnt--;
if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
if (a->ops->cleanup)
a->ops->cleanup(a, bind);
tcf_hash_destroy(a);
ret = 1;
}
}
return ret;
}
EXPORT_SYMBOL(__tcf_hash_release);
static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
struct tc_action *a)
{
struct tcf_hashinfo *hinfo = a->ops->hinfo;
struct hlist_head *head;
struct tcf_common *p;
int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
struct nlattr *nest;
spin_lock_bh(&hinfo->lock);
s_i = cb->args[0];
for (i = 0; i < (hinfo->hmask + 1); i++) {
head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
hlist_for_each_entry_rcu(p, head, tcfc_head) {
index++;
if (index < s_i)
continue;
a->priv = p;
a->order = n_i;
nest = nla_nest_start(skb, a->order);
if (nest == NULL)
goto nla_put_failure;
err = tcf_action_dump_1(skb, a, 0, 0);
if (err < 0) {
index--;
nlmsg_trim(skb, nest);
goto done;
}
nla_nest_end(skb, nest);
n_i++;
if (n_i >= TCA_ACT_MAX_PRIO)
goto done;
}
}
done:
spin_unlock_bh(&hinfo->lock);
if (n_i)
cb->args[0] += n_i;
return n_i;
nla_put_failure:
nla_nest_cancel(skb, nest);
goto done;
}
static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a)
{
struct tcf_hashinfo *hinfo = a->ops->hinfo;
struct hlist_head *head;
struct hlist_node *n;
struct tcf_common *p;
struct nlattr *nest;
int i = 0, n_i = 0;
int ret = -EINVAL;
nest = nla_nest_start(skb, a->order);
if (nest == NULL)
goto nla_put_failure;
if (nla_put_string(skb, TCA_KIND, a->ops->kind))
goto nla_put_failure;
for (i = 0; i < (hinfo->hmask + 1); i++) {
head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
hlist_for_each_entry_safe(p, n, head, tcfc_head) {
a->priv = p;
ret = __tcf_hash_release(a, false, true);
if (ret == ACT_P_DELETED) {
module_put(a->ops->owner);
n_i++;
} else if (ret < 0)
goto nla_put_failure;
}
}
if (nla_put_u32(skb, TCA_FCNT, n_i))
goto nla_put_failure;
nla_nest_end(skb, nest);
return n_i;
nla_put_failure:
nla_nest_cancel(skb, nest);
return ret;
}
static int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
int type, struct tc_action *a)
{
if (type == RTM_DELACTION) {
return tcf_del_walker(skb, a);
} else if (type == RTM_GETACTION) {
return tcf_dump_walker(skb, cb, a);
} else {
WARN(1, "tcf_generic_walker: unknown action %d\n", type);
return -EINVAL;
}
}
static struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
{
struct tcf_common *p = NULL;
struct hlist_head *head;
spin_lock_bh(&hinfo->lock);
head = &hinfo->htab[tcf_hash(index, hinfo->hmask)];
hlist_for_each_entry_rcu(p, head, tcfc_head)
if (p->tcfc_index == index)
break;
spin_unlock_bh(&hinfo->lock);
return p;
}
u32 tcf_hash_new_index(struct tcf_hashinfo *hinfo)
{
u32 val = hinfo->index;
do {
if (++val == 0)
val = 1;
} while (tcf_hash_lookup(val, hinfo));
hinfo->index = val;
return val;
}
EXPORT_SYMBOL(tcf_hash_new_index);
int tcf_hash_search(struct tc_action *a, u32 index)
{
struct tcf_hashinfo *hinfo = a->ops->hinfo;
struct tcf_common *p = tcf_hash_lookup(index, hinfo);
if (p) {
a->priv = p;
return 1;
}
return 0;
}
EXPORT_SYMBOL(tcf_hash_search);
int tcf_hash_check(u32 index, struct tc_action *a, int bind)
{
struct tcf_hashinfo *hinfo = a->ops->hinfo;
struct tcf_common *p = NULL;
if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
if (bind)
p->tcfc_bindcnt++;
p->tcfc_refcnt++;
a->priv = p;
return 1;
}
return 0;
}
EXPORT_SYMBOL(tcf_hash_check);
void tcf_hash_cleanup(struct tc_action *a, struct nlattr *est)
{
struct tcf_common *pc = a->priv;
if (est)
gen_kill_estimator(&pc->tcfc_bstats,
&pc->tcfc_rate_est);
kfree_rcu(pc, tcfc_rcu);
}
EXPORT_SYMBOL(tcf_hash_cleanup);
int tcf_hash_create(u32 index, struct nlattr *est, struct tc_action *a,
int size, int bind)
{
struct tcf_hashinfo *hinfo = a->ops->hinfo;
struct tcf_common *p = kzalloc(size, GFP_KERNEL);
if (unlikely(!p))
return -ENOMEM;
p->tcfc_refcnt = 1;
if (bind)
p->tcfc_bindcnt = 1;
spin_lock_init(&p->tcfc_lock);
INIT_HLIST_NODE(&p->tcfc_head);
p->tcfc_index = index ? index : tcf_hash_new_index(hinfo);
p->tcfc_tm.install = jiffies;
p->tcfc_tm.lastuse = jiffies;
if (est) {
int err = gen_new_estimator(&p->tcfc_bstats, NULL,
&p->tcfc_rate_est,
&p->tcfc_lock, est);
if (err) {
kfree(p);
return err;
}
}
a->priv = (void *) p;
return 0;
}
EXPORT_SYMBOL(tcf_hash_create);
void tcf_hash_insert(struct tc_action *a)
{
struct tcf_common *p = a->priv;
struct tcf_hashinfo *hinfo = a->ops->hinfo;
unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
spin_lock_bh(&hinfo->lock);
hlist_add_head(&p->tcfc_head, &hinfo->htab[h]);
spin_unlock_bh(&hinfo->lock);
}
EXPORT_SYMBOL(tcf_hash_insert);
static LIST_HEAD(act_base);
static DEFINE_RWLOCK(act_mod_lock);
int tcf_register_action(struct tc_action_ops *act, unsigned int mask)
{
struct tc_action_ops *a;
int err;
/* Must supply act, dump and init */
if (!act->act || !act->dump || !act->init)
return -EINVAL;
/* Supply defaults */
if (!act->lookup)
act->lookup = tcf_hash_search;
if (!act->walk)
act->walk = tcf_generic_walker;
act->hinfo = kmalloc(sizeof(struct tcf_hashinfo), GFP_KERNEL);
if (!act->hinfo)
return -ENOMEM;
err = tcf_hashinfo_init(act->hinfo, mask);
if (err) {
kfree(act->hinfo);
return err;
}
write_lock(&act_mod_lock);
list_for_each_entry(a, &act_base, head) {
if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
write_unlock(&act_mod_lock);
tcf_hashinfo_destroy(act->hinfo);
kfree(act->hinfo);
return -EEXIST;
}
}
list_add_tail(&act->head, &act_base);
write_unlock(&act_mod_lock);
return 0;
}
EXPORT_SYMBOL(tcf_register_action);
int tcf_unregister_action(struct tc_action_ops *act)
{
struct tc_action_ops *a;
int err = -ENOENT;
write_lock(&act_mod_lock);
list_for_each_entry(a, &act_base, head) {
if (a == act) {
list_del(&act->head);
tcf_hashinfo_destroy(act->hinfo);
kfree(act->hinfo);
err = 0;
break;
}
}
write_unlock(&act_mod_lock);
return err;
}
EXPORT_SYMBOL(tcf_unregister_action);
/* lookup by name */
static struct tc_action_ops *tc_lookup_action_n(char *kind)
{
struct tc_action_ops *a, *res = NULL;
if (kind) {
read_lock(&act_mod_lock);
list_for_each_entry(a, &act_base, head) {
if (strcmp(kind, a->kind) == 0) {
if (try_module_get(a->owner))
res = a;
break;
}
}
read_unlock(&act_mod_lock);
}
return res;
}
/* lookup by nlattr */
static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
{
struct tc_action_ops *a, *res = NULL;
if (kind) {
read_lock(&act_mod_lock);
list_for_each_entry(a, &act_base, head) {
if (nla_strcmp(kind, a->kind) == 0) {
if (try_module_get(a->owner))
res = a;
break;
}
}
read_unlock(&act_mod_lock);
}
return res;
}
int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions,
struct tcf_result *res)
{
const struct tc_action *a;
int ret = -1;
if (skb->tc_verd & TC_NCLS) {
skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
ret = TC_ACT_OK;
goto exec_done;
}
list_for_each_entry(a, actions, list) {
repeat:
ret = a->ops->act(skb, a, res);
if (ret == TC_ACT_REPEAT)
goto repeat; /* we need a ttl - JHS */
if (ret != TC_ACT_PIPE)
goto exec_done;
}
exec_done:
return ret;
}
EXPORT_SYMBOL(tcf_action_exec);
int tcf_action_destroy(struct list_head *actions, int bind)
{
struct tc_action *a, *tmp;
int ret = 0;
list_for_each_entry_safe(a, tmp, actions, list) {
ret = __tcf_hash_release(a, bind, true);
if (ret == ACT_P_DELETED)
module_put(a->ops->owner);
else if (ret < 0)
return ret;
list_del(&a->list);
kfree(a);
}
return ret;
}
int
tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
return a->ops->dump(skb, a, bind, ref);
}
int
tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
int err = -EINVAL;
unsigned char *b = skb_tail_pointer(skb);
struct nlattr *nest;
if (nla_put_string(skb, TCA_KIND, a->ops->kind))
goto nla_put_failure;
if (tcf_action_copy_stats(skb, a, 0))
goto nla_put_failure;
nest = nla_nest_start(skb, TCA_OPTIONS);
if (nest == NULL)
goto nla_put_failure;
err = tcf_action_dump_old(skb, a, bind, ref);
if (err > 0) {
nla_nest_end(skb, nest);
return err;
}
nla_put_failure:
nlmsg_trim(skb, b);
return -1;
}
EXPORT_SYMBOL(tcf_action_dump_1);
int
tcf_action_dump(struct sk_buff *skb, struct list_head *actions, int bind, int ref)
{
struct tc_action *a;
int err = -EINVAL;
struct nlattr *nest;
list_for_each_entry(a, actions, list) {
nest = nla_nest_start(skb, a->order);
if (nest == NULL)
goto nla_put_failure;
err = tcf_action_dump_1(skb, a, bind, ref);
if (err < 0)
goto errout;
nla_nest_end(skb, nest);
}
return 0;
nla_put_failure:
err = -EINVAL;
errout:
nla_nest_cancel(skb, nest);
return err;
}
struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
struct nlattr *est, char *name, int ovr,
int bind)
{
struct tc_action *a;
struct tc_action_ops *a_o;
char act_name[IFNAMSIZ];
struct nlattr *tb[TCA_ACT_MAX + 1];
struct nlattr *kind;
int err;
if (name == NULL) {
err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
if (err < 0)
goto err_out;
err = -EINVAL;
kind = tb[TCA_ACT_KIND];
if (kind == NULL)
goto err_out;
if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
goto err_out;
} else {
err = -EINVAL;
if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
goto err_out;
}
a_o = tc_lookup_action_n(act_name);
if (a_o == NULL) {
#ifdef CONFIG_MODULES
rtnl_unlock();
request_module("act_%s", act_name);
rtnl_lock();
a_o = tc_lookup_action_n(act_name);
/* We dropped the RTNL semaphore in order to
* perform the module load. So, even if we
* succeeded in loading the module we have to
* tell the caller to replay the request. We
* indicate this using -EAGAIN.
*/
if (a_o != NULL) {
err = -EAGAIN;
goto err_mod;
}
#endif
err = -ENOENT;
goto err_out;
}
err = -ENOMEM;
a = kzalloc(sizeof(*a), GFP_KERNEL);
if (a == NULL)
goto err_mod;
a->ops = a_o;
INIT_LIST_HEAD(&a->list);
/* backward compatibility for policer */
if (name == NULL)
err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
else
err = a_o->init(net, nla, est, a, ovr, bind);
if (err < 0)
goto err_free;
/* module count goes up only when brand new policy is created
* if it exists and is only bound to in a_o->init() then
* ACT_P_CREATED is not returned (a zero is).
*/
if (err != ACT_P_CREATED)
module_put(a_o->owner);
return a;
err_free:
kfree(a);
err_mod:
module_put(a_o->owner);
err_out:
return ERR_PTR(err);
}
int tcf_action_init(struct net *net, struct nlattr *nla,
struct nlattr *est, char *name, int ovr,
int bind, struct list_head *actions)
{
struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
struct tc_action *act;
int err;
int i;
err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
if (err < 0)
return err;
for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
if (IS_ERR(act)) {
err = PTR_ERR(act);
goto err;
}
act->order = i;
list_add_tail(&act->list, actions);
}
return 0;
err:
tcf_action_destroy(actions, bind);
return err;
}
int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
int compat_mode)
{
int err = 0;
struct gnet_dump d;
struct tcf_common *p = a->priv;
if (p == NULL)
goto errout;
/* compat_mode being true specifies a call that is supposed
* to add additional backward compatibility statistic TLVs.
*/
if (compat_mode) {
if (a->type == TCA_OLD_COMPAT)
err = gnet_stats_start_copy_compat(skb, 0,
TCA_STATS, TCA_XSTATS, &p->tcfc_lock, &d);
else
return 0;
} else
err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
&p->tcfc_lock, &d);
if (err < 0)
goto errout;
if (gnet_stats_copy_basic(&d, NULL, &p->tcfc_bstats) < 0 ||
gnet_stats_copy_rate_est(&d, &p->tcfc_bstats,
&p->tcfc_rate_est) < 0 ||
gnet_stats_copy_queue(&d, NULL,
&p->tcfc_qstats,
p->tcfc_qstats.qlen) < 0)
goto errout;
if (gnet_stats_finish_copy(&d) < 0)
goto errout;
return 0;
errout:
return -1;
}
static int
tca_get_fill(struct sk_buff *skb, struct list_head *actions, u32 portid, u32 seq,
u16 flags, int event, int bind, int ref)
{
struct tcamsg *t;
struct nlmsghdr *nlh;
unsigned char *b = skb_tail_pointer(skb);
struct nlattr *nest;
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
if (!nlh)
goto out_nlmsg_trim;
t = nlmsg_data(nlh);
t->tca_family = AF_UNSPEC;
t->tca__pad1 = 0;
t->tca__pad2 = 0;
nest = nla_nest_start(skb, TCA_ACT_TAB);
if (nest == NULL)
goto out_nlmsg_trim;
if (tcf_action_dump(skb, actions, bind, ref) < 0)
goto out_nlmsg_trim;
nla_nest_end(skb, nest);
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
return skb->len;
out_nlmsg_trim:
nlmsg_trim(skb, b);
return -1;
}
static int
act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
struct list_head *actions, int event)
{
struct sk_buff *skb;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return -ENOBUFS;
if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
kfree_skb(skb);
return -EINVAL;
}
return rtnl_unicast(skb, net, portid);
}
static struct tc_action *create_a(int i)
{
struct tc_action *act;
act = kzalloc(sizeof(*act), GFP_KERNEL);
if (act == NULL) {
pr_debug("create_a: failed to alloc!\n");
return NULL;
}
act->order = i;
INIT_LIST_HEAD(&act->list);
return act;
}
static struct tc_action *
tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
{
struct nlattr *tb[TCA_ACT_MAX + 1];
struct tc_action *a;
int index;
int err;
err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
if (err < 0)
goto err_out;
err = -EINVAL;
if (tb[TCA_ACT_INDEX] == NULL ||
nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
goto err_out;
index = nla_get_u32(tb[TCA_ACT_INDEX]);
err = -ENOMEM;
a = create_a(0);
if (a == NULL)
goto err_out;
err = -EINVAL;
a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
if (a->ops == NULL) /* could happen in batch of actions */
goto err_free;
err = -ENOENT;
if (a->ops->lookup(a, index) == 0)
goto err_mod;
module_put(a->ops->owner);
return a;
err_mod:
module_put(a->ops->owner);
err_free:
kfree(a);
err_out:
return ERR_PTR(err);
}
static void cleanup_a(struct list_head *actions)
{
struct tc_action *a, *tmp;
list_for_each_entry_safe(a, tmp, actions, list) {
list_del(&a->list);
kfree(a);
}
}
static int tca_action_flush(struct net *net, struct nlattr *nla,
struct nlmsghdr *n, u32 portid)
{
struct sk_buff *skb;
unsigned char *b;
struct nlmsghdr *nlh;
struct tcamsg *t;
struct netlink_callback dcb;
struct nlattr *nest;
struct nlattr *tb[TCA_ACT_MAX + 1];
struct nlattr *kind;
struct tc_action a;
int err = -ENOMEM;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb) {
pr_debug("tca_action_flush: failed skb alloc\n");
return err;
}
b = skb_tail_pointer(skb);
err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
if (err < 0)
goto err_out;
err = -EINVAL;
kind = tb[TCA_ACT_KIND];
memset(&a, 0, sizeof(struct tc_action));
INIT_LIST_HEAD(&a.list);
a.ops = tc_lookup_action(kind);
if (a.ops == NULL) /*some idjot trying to flush unknown action */
goto err_out;
nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
if (!nlh)
goto out_module_put;
t = nlmsg_data(nlh);
t->tca_family = AF_UNSPEC;
t->tca__pad1 = 0;
t->tca__pad2 = 0;
nest = nla_nest_start(skb, TCA_ACT_TAB);
if (nest == NULL)
goto out_module_put;
err = a.ops->walk(skb, &dcb, RTM_DELACTION, &a);
if (err < 0)
goto out_module_put;
if (err == 0)
goto noflush_out;
nla_nest_end(skb, nest);
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
nlh->nlmsg_flags |= NLM_F_ROOT;
module_put(a.ops->owner);
err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
n->nlmsg_flags & NLM_F_ECHO);
if (err > 0)
return 0;
return err;
out_module_put:
module_put(a.ops->owner);
err_out:
noflush_out:
kfree_skb(skb);
return err;
}
static int
tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
u32 portid)
{
int ret;
struct sk_buff *skb;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return -ENOBUFS;
if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
0, 1) <= 0) {
kfree_skb(skb);
return -EINVAL;
}
/* now do the delete */
ret = tcf_action_destroy(actions, 0);
if (ret < 0) {
kfree_skb(skb);
return ret;
}
ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
n->nlmsg_flags & NLM_F_ECHO);
if (ret > 0)
return 0;
return ret;
}
static int
tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
u32 portid, int event)
{
int i, ret;
struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
struct tc_action *act;
LIST_HEAD(actions);
ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
if (ret < 0)
return ret;
if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
if (tb[1] != NULL)
return tca_action_flush(net, tb[1], n, portid);
else
return -EINVAL;
}
for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
act = tcf_action_get_1(tb[i], n, portid);
if (IS_ERR(act)) {
ret = PTR_ERR(act);
goto err;
}
act->order = i;
list_add_tail(&act->list, &actions);
}
if (event == RTM_GETACTION)
ret = act_get_notify(net, portid, n, &actions, event);
else { /* delete */
ret = tcf_del_notify(net, n, &actions, portid);
if (ret)
goto err;
return ret;
}
err:
cleanup_a(&actions);
return ret;
}
static int
tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
u32 portid)
{
struct sk_buff *skb;
int err = 0;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return -ENOBUFS;
if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
RTM_NEWACTION, 0, 0) <= 0) {
kfree_skb(skb);
return -EINVAL;
}
err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
n->nlmsg_flags & NLM_F_ECHO);
if (err > 0)
err = 0;
return err;
}
static int
tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
u32 portid, int ovr)
{
int ret = 0;
LIST_HEAD(actions);
ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
if (ret)
goto done;
/* dump then free all the actions after update; inserted policy
* stays intact
*/
ret = tcf_add_notify(net, n, &actions, portid);
cleanup_a(&actions);
done:
return ret;
}
static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
{
struct net *net = sock_net(skb->sk);
struct nlattr *tca[TCA_ACT_MAX + 1];
u32 portid = skb ? NETLINK_CB(skb).portid : 0;
int ret = 0, ovr = 0;
if ((n->nlmsg_type != RTM_GETACTION) && !netlink_capable(skb, CAP_NET_ADMIN))
return -EPERM;
ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
if (ret < 0)
return ret;
if (tca[TCA_ACT_TAB] == NULL) {
pr_notice("tc_ctl_action: received NO action attribs\n");
return -EINVAL;
}
/* n->nlmsg_flags & NLM_F_CREATE */
switch (n->nlmsg_type) {
case RTM_NEWACTION:
/* we are going to assume all other flags
* imply create only if it doesn't exist
* Note that CREATE | EXCL implies that
* but since we want avoid ambiguity (eg when flags
* is zero) then just set this
*/
if (n->nlmsg_flags & NLM_F_REPLACE)
ovr = 1;
replay:
ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
if (ret == -EAGAIN)
goto replay;
break;
case RTM_DELACTION:
ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
portid, RTM_DELACTION);
break;
case RTM_GETACTION:
ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
portid, RTM_GETACTION);
break;
default:
BUG();
}
return ret;
}
static struct nlattr *
find_dump_kind(const struct nlmsghdr *n)
{
struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
struct nlattr *nla[TCAA_MAX + 1];
struct nlattr *kind;
if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
return NULL;
tb1 = nla[TCA_ACT_TAB];
if (tb1 == NULL)
return NULL;
if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
return NULL;
if (tb[1] == NULL)
return NULL;
if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
nla_len(tb[1]), NULL) < 0)
return NULL;
kind = tb2[TCA_ACT_KIND];
return kind;
}
static int
tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
{
struct nlmsghdr *nlh;
unsigned char *b = skb_tail_pointer(skb);
struct nlattr *nest;
struct tc_action_ops *a_o;
struct tc_action a;
int ret = 0;
struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
struct nlattr *kind = find_dump_kind(cb->nlh);
if (kind == NULL) {
pr_info("tc_dump_action: action bad kind\n");
return 0;
}
a_o = tc_lookup_action(kind);
if (a_o == NULL)
return 0;
memset(&a, 0, sizeof(struct tc_action));
a.ops = a_o;
nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
cb->nlh->nlmsg_type, sizeof(*t), 0);
if (!nlh)
goto out_module_put;
t = nlmsg_data(nlh);
t->tca_family = AF_UNSPEC;
t->tca__pad1 = 0;
t->tca__pad2 = 0;
nest = nla_nest_start(skb, TCA_ACT_TAB);
if (nest == NULL)
goto out_module_put;
ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
if (ret < 0)
goto out_module_put;
if (ret > 0) {
nla_nest_end(skb, nest);
ret = skb->len;
} else
nla_nest_cancel(skb, nest);
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
if (NETLINK_CB(cb->skb).portid && ret)
nlh->nlmsg_flags |= NLM_F_MULTI;
module_put(a_o->owner);
return skb->len;
out_module_put:
module_put(a_o->owner);
nlmsg_trim(skb, b);
return skb->len;
}
static int __init tc_action_init(void)
{
rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
NULL);
return 0;
}
subsys_initcall(tc_action_init);
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