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linux/net/sched/cls_api.c
Vlad Buslov 0fca55ed98 net: sched: remove redundant 'rtnl_held' argument 
Functions tfilter_notify_chain() and tcf_get_next_proto() are always called
with rtnl lock held in current implementation. Moreover, attempting to call
them without rtnl lock would cause a warning down the call chain in
function __tcf_get_next_proto() that requires the lock to be held by
callers. Remove the 'rtnl_held' argument in order to simplify the code and
make rtnl lock requirement explicit.

Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Link: https://lore.kernel.org/r/20201127151205.23492-1-vladbu@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01 11:24:56 -08:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* net/sched/cls_api.c Packet classifier API.
*
* 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/err.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/jhash.h>
#include <linux/rculist.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
#include <net/tc_act/tc_pedit.h>
#include <net/tc_act/tc_mirred.h>
#include <net/tc_act/tc_vlan.h>
#include <net/tc_act/tc_tunnel_key.h>
#include <net/tc_act/tc_csum.h>
#include <net/tc_act/tc_gact.h>
#include <net/tc_act/tc_police.h>
#include <net/tc_act/tc_sample.h>
#include <net/tc_act/tc_skbedit.h>
#include <net/tc_act/tc_ct.h>
#include <net/tc_act/tc_mpls.h>
#include <net/tc_act/tc_gate.h>
#include <net/flow_offload.h>
extern const struct nla_policy rtm_tca_policy[TCA_MAX + 1];
/* The list of all installed classifier types */
static LIST_HEAD(tcf_proto_base);
/* Protects list of registered TC modules. It is pure SMP lock. */
static DEFINE_RWLOCK(cls_mod_lock);
static u32 destroy_obj_hashfn(const struct tcf_proto *tp)
{
return jhash_3words(tp->chain->index, tp->prio,
(__force __u32)tp->protocol, 0);
}
static void tcf_proto_signal_destroying(struct tcf_chain *chain,
struct tcf_proto *tp)
{
struct tcf_block *block = chain->block;
mutex_lock(&block->proto_destroy_lock);
hash_add_rcu(block->proto_destroy_ht, &tp->destroy_ht_node,
destroy_obj_hashfn(tp));
mutex_unlock(&block->proto_destroy_lock);
}
static bool tcf_proto_cmp(const struct tcf_proto *tp1,
const struct tcf_proto *tp2)
{
return tp1->chain->index == tp2->chain->index &&
tp1->prio == tp2->prio &&
tp1->protocol == tp2->protocol;
}
static bool tcf_proto_exists_destroying(struct tcf_chain *chain,
struct tcf_proto *tp)
{
u32 hash = destroy_obj_hashfn(tp);
struct tcf_proto *iter;
bool found = false;
rcu_read_lock();
hash_for_each_possible_rcu(chain->block->proto_destroy_ht, iter,
destroy_ht_node, hash) {
if (tcf_proto_cmp(tp, iter)) {
found = true;
break;
}
}
rcu_read_unlock();
return found;
}
static void
tcf_proto_signal_destroyed(struct tcf_chain *chain, struct tcf_proto *tp)
{
struct tcf_block *block = chain->block;
mutex_lock(&block->proto_destroy_lock);
if (hash_hashed(&tp->destroy_ht_node))
hash_del_rcu(&tp->destroy_ht_node);
mutex_unlock(&block->proto_destroy_lock);
}
/* Find classifier type by string name */
static const struct tcf_proto_ops *__tcf_proto_lookup_ops(const char *kind)
{
const struct tcf_proto_ops *t, *res = NULL;
if (kind) {
read_lock(&cls_mod_lock);
list_for_each_entry(t, &tcf_proto_base, head) {
if (strcmp(kind, t->kind) == 0) {
if (try_module_get(t->owner))
res = t;
break;
}
}
read_unlock(&cls_mod_lock);
}
return res;
}
static const struct tcf_proto_ops *
tcf_proto_lookup_ops(const char *kind, bool rtnl_held,
struct netlink_ext_ack *extack)
{
const struct tcf_proto_ops *ops;
ops = __tcf_proto_lookup_ops(kind);
if (ops)
return ops;
#ifdef CONFIG_MODULES
if (rtnl_held)
rtnl_unlock();
request_module("cls_%s", kind);
if (rtnl_held)
rtnl_lock();
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 (ops) {
module_put(ops->owner);
return ERR_PTR(-EAGAIN);
}
#endif
NL_SET_ERR_MSG(extack, "TC classifier not found");
return ERR_PTR(-ENOENT);
}
/* Register(unregister) new classifier type */
int register_tcf_proto_ops(struct tcf_proto_ops *ops)
{
struct tcf_proto_ops *t;
int rc = -EEXIST;
write_lock(&cls_mod_lock);
list_for_each_entry(t, &tcf_proto_base, head)
if (!strcmp(ops->kind, t->kind))
goto out;
list_add_tail(&ops->head, &tcf_proto_base);
rc = 0;
out:
write_unlock(&cls_mod_lock);
return rc;
}
EXPORT_SYMBOL(register_tcf_proto_ops);
static struct workqueue_struct *tc_filter_wq;
int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
{
struct tcf_proto_ops *t;
int rc = -ENOENT;
/* Wait for outstanding call_rcu()s, if any, from a
* tcf_proto_ops's destroy() handler.
*/
rcu_barrier();
flush_workqueue(tc_filter_wq);
write_lock(&cls_mod_lock);
list_for_each_entry(t, &tcf_proto_base, head) {
if (t == ops) {
list_del(&t->head);
rc = 0;
break;
}
}
write_unlock(&cls_mod_lock);
return rc;
}
EXPORT_SYMBOL(unregister_tcf_proto_ops);
bool tcf_queue_work(struct rcu_work *rwork, work_func_t func)
{
INIT_RCU_WORK(rwork, func);
return queue_rcu_work(tc_filter_wq, rwork);
}
EXPORT_SYMBOL(tcf_queue_work);
/* 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 TC_H_MAJ(first);
}
static bool tcf_proto_check_kind(struct nlattr *kind, char *name)
{
if (kind)
return nla_strscpy(name, kind, IFNAMSIZ) < 0;
memset(name, 0, IFNAMSIZ);
return false;
}
static bool tcf_proto_is_unlocked(const char *kind)
{
const struct tcf_proto_ops *ops;
bool ret;
if (strlen(kind) == 0)
return false;
ops = tcf_proto_lookup_ops(kind, false, NULL);
/* On error return false to take rtnl lock. Proto lookup/create
* functions will perform lookup again and properly handle errors.
*/
if (IS_ERR(ops))
return false;
ret = !!(ops->flags & TCF_PROTO_OPS_DOIT_UNLOCKED);
module_put(ops->owner);
return ret;
}
static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
u32 prio, struct tcf_chain *chain,
bool rtnl_held,
struct netlink_ext_ack *extack)
{
struct tcf_proto *tp;
int err;
tp = kzalloc(sizeof(*tp), GFP_KERNEL);
if (!tp)
return ERR_PTR(-ENOBUFS);
tp->ops = tcf_proto_lookup_ops(kind, rtnl_held, extack);
if (IS_ERR(tp->ops)) {
err = PTR_ERR(tp->ops);
goto errout;
}
tp->classify = tp->ops->classify;
tp->protocol = protocol;
tp->prio = prio;
tp->chain = chain;
spin_lock_init(&tp->lock);
refcount_set(&tp->refcnt, 1);
err = tp->ops->init(tp);
if (err) {
module_put(tp->ops->owner);
goto errout;
}
return tp;
errout:
kfree(tp);
return ERR_PTR(err);
}
static void tcf_proto_get(struct tcf_proto *tp)
{
refcount_inc(&tp->refcnt);
}
static void tcf_chain_put(struct tcf_chain *chain);
static void tcf_proto_destroy(struct tcf_proto *tp, bool rtnl_held,
bool sig_destroy, struct netlink_ext_ack *extack)
{
tp->ops->destroy(tp, rtnl_held, extack);
if (sig_destroy)
tcf_proto_signal_destroyed(tp->chain, tp);
tcf_chain_put(tp->chain);
module_put(tp->ops->owner);
kfree_rcu(tp, rcu);
}
static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held,
struct netlink_ext_ack *extack)
{
if (refcount_dec_and_test(&tp->refcnt))
tcf_proto_destroy(tp, rtnl_held, true, extack);
}
static bool tcf_proto_check_delete(struct tcf_proto *tp)
{
if (tp->ops->delete_empty)
return tp->ops->delete_empty(tp);
tp->deleting = true;
return tp->deleting;
}
static void tcf_proto_mark_delete(struct tcf_proto *tp)
{
spin_lock(&tp->lock);
tp->deleting = true;
spin_unlock(&tp->lock);
}
static bool tcf_proto_is_deleting(struct tcf_proto *tp)
{
bool deleting;
spin_lock(&tp->lock);
deleting = tp->deleting;
spin_unlock(&tp->lock);
return deleting;
}
#define ASSERT_BLOCK_LOCKED(block) \
lockdep_assert_held(&(block)->lock)
struct tcf_filter_chain_list_item {
struct list_head list;
tcf_chain_head_change_t *chain_head_change;
void *chain_head_change_priv;
};
static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
u32 chain_index)
{
struct tcf_chain *chain;
ASSERT_BLOCK_LOCKED(block);
chain = kzalloc(sizeof(*chain), GFP_KERNEL);
if (!chain)
return NULL;
list_add_tail_rcu(&chain->list, &block->chain_list);
mutex_init(&chain->filter_chain_lock);
chain->block = block;
chain->index = chain_index;
chain->refcnt = 1;
if (!chain->index)
block->chain0.chain = chain;
return chain;
}
static void tcf_chain_head_change_item(struct tcf_filter_chain_list_item *item,
struct tcf_proto *tp_head)
{
if (item->chain_head_change)
item->chain_head_change(tp_head, item->chain_head_change_priv);
}
static void tcf_chain0_head_change(struct tcf_chain *chain,
struct tcf_proto *tp_head)
{
struct tcf_filter_chain_list_item *item;
struct tcf_block *block = chain->block;
if (chain->index)
return;
mutex_lock(&block->lock);
list_for_each_entry(item, &block->chain0.filter_chain_list, list)
tcf_chain_head_change_item(item, tp_head);
mutex_unlock(&block->lock);
}
/* Returns true if block can be safely freed. */
static bool tcf_chain_detach(struct tcf_chain *chain)
{
struct tcf_block *block = chain->block;
ASSERT_BLOCK_LOCKED(block);
list_del_rcu(&chain->list);
if (!chain->index)
block->chain0.chain = NULL;
if (list_empty(&block->chain_list) &&
refcount_read(&block->refcnt) == 0)
return true;
return false;
}
static void tcf_block_destroy(struct tcf_block *block)
{
mutex_destroy(&block->lock);
mutex_destroy(&block->proto_destroy_lock);
kfree_rcu(block, rcu);
}
static void tcf_chain_destroy(struct tcf_chain *chain, bool free_block)
{
struct tcf_block *block = chain->block;
mutex_destroy(&chain->filter_chain_lock);
kfree_rcu(chain, rcu);
if (free_block)
tcf_block_destroy(block);
}
static void tcf_chain_hold(struct tcf_chain *chain)
{
ASSERT_BLOCK_LOCKED(chain->block);
++chain->refcnt;
}
static bool tcf_chain_held_by_acts_only(struct tcf_chain *chain)
{
ASSERT_BLOCK_LOCKED(chain->block);
/* In case all the references are action references, this
* chain should not be shown to the user.
*/
return chain->refcnt == chain->action_refcnt;
}
static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block,
u32 chain_index)
{
struct tcf_chain *chain;
ASSERT_BLOCK_LOCKED(block);
list_for_each_entry(chain, &block->chain_list, list) {
if (chain->index == chain_index)
return chain;
}
return NULL;
}
#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
static struct tcf_chain *tcf_chain_lookup_rcu(const struct tcf_block *block,
u32 chain_index)
{
struct tcf_chain *chain;
list_for_each_entry_rcu(chain, &block->chain_list, list) {
if (chain->index == chain_index)
return chain;
}
return NULL;
}
#endif
static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
u32 seq, u16 flags, int event, bool unicast);
static struct tcf_chain *__tcf_chain_get(struct tcf_block *block,
u32 chain_index, bool create,
bool by_act)
{
struct tcf_chain *chain = NULL;
bool is_first_reference;
mutex_lock(&block->lock);
chain = tcf_chain_lookup(block, chain_index);
if (chain) {
tcf_chain_hold(chain);
} else {
if (!create)
goto errout;
chain = tcf_chain_create(block, chain_index);
if (!chain)
goto errout;
}
if (by_act)
++chain->action_refcnt;
is_first_reference = chain->refcnt - chain->action_refcnt == 1;
mutex_unlock(&block->lock);
/* Send notification only in case we got the first
* non-action reference. Until then, the chain acts only as
* a placeholder for actions pointing to it and user ought
* not know about them.
*/
if (is_first_reference && !by_act)
tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
RTM_NEWCHAIN, false);
return chain;
errout:
mutex_unlock(&block->lock);
return chain;
}
static struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
bool create)
{
return __tcf_chain_get(block, chain_index, create, false);
}
struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block, u32 chain_index)
{
return __tcf_chain_get(block, chain_index, true, true);
}
EXPORT_SYMBOL(tcf_chain_get_by_act);
static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
void *tmplt_priv);
static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
void *tmplt_priv, u32 chain_index,
struct tcf_block *block, struct sk_buff *oskb,
u32 seq, u16 flags, bool unicast);
static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
bool explicitly_created)
{
struct tcf_block *block = chain->block;
const struct tcf_proto_ops *tmplt_ops;
bool free_block = false;
unsigned int refcnt;
void *tmplt_priv;
mutex_lock(&block->lock);
if (explicitly_created) {
if (!chain->explicitly_created) {
mutex_unlock(&block->lock);
return;
}
chain->explicitly_created = false;
}
if (by_act)
chain->action_refcnt--;
/* tc_chain_notify_delete can't be called while holding block lock.
* However, when block is unlocked chain can be changed concurrently, so
* save these to temporary variables.
*/
refcnt = --chain->refcnt;
tmplt_ops = chain->tmplt_ops;
tmplt_priv = chain->tmplt_priv;
/* The last dropped non-action reference will trigger notification. */
if (refcnt - chain->action_refcnt == 0 && !by_act) {
tc_chain_notify_delete(tmplt_ops, tmplt_priv, chain->index,
block, NULL, 0, 0, false);
/* Last reference to chain, no need to lock. */
chain->flushing = false;
}
if (refcnt == 0)
free_block = tcf_chain_detach(chain);
mutex_unlock(&block->lock);
if (refcnt == 0) {
tc_chain_tmplt_del(tmplt_ops, tmplt_priv);
tcf_chain_destroy(chain, free_block);
}
}
static void tcf_chain_put(struct tcf_chain *chain)
{
__tcf_chain_put(chain, false, false);
}
void tcf_chain_put_by_act(struct tcf_chain *chain)
{
__tcf_chain_put(chain, true, false);
}
EXPORT_SYMBOL(tcf_chain_put_by_act);
static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
{
__tcf_chain_put(chain, false, true);
}
static void tcf_chain_flush(struct tcf_chain *chain, bool rtnl_held)
{
struct tcf_proto *tp, *tp_next;
mutex_lock(&chain->filter_chain_lock);
tp = tcf_chain_dereference(chain->filter_chain, chain);
while (tp) {
tp_next = rcu_dereference_protected(tp->next, 1);
tcf_proto_signal_destroying(chain, tp);
tp = tp_next;
}
tp = tcf_chain_dereference(chain->filter_chain, chain);
RCU_INIT_POINTER(chain->filter_chain, NULL);
tcf_chain0_head_change(chain, NULL);
chain->flushing = true;
mutex_unlock(&chain->filter_chain_lock);
while (tp) {
tp_next = rcu_dereference_protected(tp->next, 1);
tcf_proto_put(tp, rtnl_held, NULL);
tp = tp_next;
}
}
static int tcf_block_setup(struct tcf_block *block,
struct flow_block_offload *bo);
static void tcf_block_offload_init(struct flow_block_offload *bo,
struct net_device *dev, struct Qdisc *sch,
enum flow_block_command command,
enum flow_block_binder_type binder_type,
struct flow_block *flow_block,
bool shared, struct netlink_ext_ack *extack)
{
bo->net = dev_net(dev);
bo->command = command;
bo->binder_type = binder_type;
bo->block = flow_block;
bo->block_shared = shared;
bo->extack = extack;
bo->sch = sch;
INIT_LIST_HEAD(&bo->cb_list);
}
static void tcf_block_unbind(struct tcf_block *block,
struct flow_block_offload *bo);
static void tc_block_indr_cleanup(struct flow_block_cb *block_cb)
{
struct tcf_block *block = block_cb->indr.data;
struct net_device *dev = block_cb->indr.dev;
struct Qdisc *sch = block_cb->indr.sch;
struct netlink_ext_ack extack = {};
struct flow_block_offload bo;
tcf_block_offload_init(&bo, dev, sch, FLOW_BLOCK_UNBIND,
block_cb->indr.binder_type,
&block->flow_block, tcf_block_shared(block),
&extack);
rtnl_lock();
down_write(&block->cb_lock);
list_del(&block_cb->driver_list);
list_move(&block_cb->list, &bo.cb_list);
tcf_block_unbind(block, &bo);
up_write(&block->cb_lock);
rtnl_unlock();
}
static bool tcf_block_offload_in_use(struct tcf_block *block)
{
return atomic_read(&block->offloadcnt);
}
static int tcf_block_offload_cmd(struct tcf_block *block,
struct net_device *dev, struct Qdisc *sch,
struct tcf_block_ext_info *ei,
enum flow_block_command command,
struct netlink_ext_ack *extack)
{
struct flow_block_offload bo = {};
tcf_block_offload_init(&bo, dev, sch, command, ei->binder_type,
&block->flow_block, tcf_block_shared(block),
extack);
if (dev->netdev_ops->ndo_setup_tc) {
int err;
err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
if (err < 0) {
if (err != -EOPNOTSUPP)
NL_SET_ERR_MSG(extack, "Driver ndo_setup_tc failed");
return err;
}
return tcf_block_setup(block, &bo);
}
flow_indr_dev_setup_offload(dev, sch, TC_SETUP_BLOCK, block, &bo,
tc_block_indr_cleanup);
tcf_block_setup(block, &bo);
return -EOPNOTSUPP;
}
static int tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
struct tcf_block_ext_info *ei,
struct netlink_ext_ack *extack)
{
struct net_device *dev = q->dev_queue->dev;
int err;
down_write(&block->cb_lock);
/* If tc offload feature is disabled and the block we try to bind
* to already has some offloaded filters, forbid to bind.
*/
if (dev->netdev_ops->ndo_setup_tc &&
!tc_can_offload(dev) &&
tcf_block_offload_in_use(block)) {
NL_SET_ERR_MSG(extack, "Bind to offloaded block failed as dev has offload disabled");
err = -EOPNOTSUPP;
goto err_unlock;
}
err = tcf_block_offload_cmd(block, dev, q, ei, FLOW_BLOCK_BIND, extack);
if (err == -EOPNOTSUPP)
goto no_offload_dev_inc;
if (err)
goto err_unlock;
up_write(&block->cb_lock);
return 0;
no_offload_dev_inc:
if (tcf_block_offload_in_use(block))
goto err_unlock;
err = 0;
block->nooffloaddevcnt++;
err_unlock:
up_write(&block->cb_lock);
return err;
}
static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
struct tcf_block_ext_info *ei)
{
struct net_device *dev = q->dev_queue->dev;
int err;
down_write(&block->cb_lock);
err = tcf_block_offload_cmd(block, dev, q, ei, FLOW_BLOCK_UNBIND, NULL);
if (err == -EOPNOTSUPP)
goto no_offload_dev_dec;
up_write(&block->cb_lock);
return;
no_offload_dev_dec:
WARN_ON(block->nooffloaddevcnt-- == 0);
up_write(&block->cb_lock);
}
static int
tcf_chain0_head_change_cb_add(struct tcf_block *block,
struct tcf_block_ext_info *ei,
struct netlink_ext_ack *extack)
{
struct tcf_filter_chain_list_item *item;
struct tcf_chain *chain0;
item = kmalloc(sizeof(*item), GFP_KERNEL);
if (!item) {
NL_SET_ERR_MSG(extack, "Memory allocation for head change callback item failed");
return -ENOMEM;
}
item->chain_head_change = ei->chain_head_change;
item->chain_head_change_priv = ei->chain_head_change_priv;
mutex_lock(&block->lock);
chain0 = block->chain0.chain;
if (chain0)
tcf_chain_hold(chain0);
else
list_add(&item->list, &block->chain0.filter_chain_list);
mutex_unlock(&block->lock);
if (chain0) {
struct tcf_proto *tp_head;
mutex_lock(&chain0->filter_chain_lock);
tp_head = tcf_chain_dereference(chain0->filter_chain, chain0);
if (tp_head)
tcf_chain_head_change_item(item, tp_head);
mutex_lock(&block->lock);
list_add(&item->list, &block->chain0.filter_chain_list);
mutex_unlock(&block->lock);
mutex_unlock(&chain0->filter_chain_lock);
tcf_chain_put(chain0);
}
return 0;
}
static void
tcf_chain0_head_change_cb_del(struct tcf_block *block,
struct tcf_block_ext_info *ei)
{
struct tcf_filter_chain_list_item *item;
mutex_lock(&block->lock);
list_for_each_entry(item, &block->chain0.filter_chain_list, list) {
if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
(item->chain_head_change == ei->chain_head_change &&
item->chain_head_change_priv == ei->chain_head_change_priv)) {
if (block->chain0.chain)
tcf_chain_head_change_item(item, NULL);
list_del(&item->list);
mutex_unlock(&block->lock);
kfree(item);
return;
}
}
mutex_unlock(&block->lock);
WARN_ON(1);
}
struct tcf_net {
spinlock_t idr_lock; /* Protects idr */
struct idr idr;
};
static unsigned int tcf_net_id;
static int tcf_block_insert(struct tcf_block *block, struct net *net,
struct netlink_ext_ack *extack)
{
struct tcf_net *tn = net_generic(net, tcf_net_id);
int err;
idr_preload(GFP_KERNEL);
spin_lock(&tn->idr_lock);
err = idr_alloc_u32(&tn->idr, block, &block->index, block->index,
GFP_NOWAIT);
spin_unlock(&tn->idr_lock);
idr_preload_end();
return err;
}
static void tcf_block_remove(struct tcf_block *block, struct net *net)
{
struct tcf_net *tn = net_generic(net, tcf_net_id);
spin_lock(&tn->idr_lock);
idr_remove(&tn->idr, block->index);
spin_unlock(&tn->idr_lock);
}
static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
u32 block_index,
struct netlink_ext_ack *extack)
{
struct tcf_block *block;
block = kzalloc(sizeof(*block), GFP_KERNEL);
if (!block) {
NL_SET_ERR_MSG(extack, "Memory allocation for block failed");
return ERR_PTR(-ENOMEM);
}
mutex_init(&block->lock);
mutex_init(&block->proto_destroy_lock);
init_rwsem(&block->cb_lock);
flow_block_init(&block->flow_block);
INIT_LIST_HEAD(&block->chain_list);
INIT_LIST_HEAD(&block->owner_list);
INIT_LIST_HEAD(&block->chain0.filter_chain_list);
refcount_set(&block->refcnt, 1);
block->net = net;
block->index = block_index;
/* Don't store q pointer for blocks which are shared */
if (!tcf_block_shared(block))
block->q = q;
return block;
}
static struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index)
{
struct tcf_net *tn = net_generic(net, tcf_net_id);
return idr_find(&tn->idr, block_index);
}
static struct tcf_block *tcf_block_refcnt_get(struct net *net, u32 block_index)
{
struct tcf_block *block;
rcu_read_lock();
block = tcf_block_lookup(net, block_index);
if (block && !refcount_inc_not_zero(&block->refcnt))
block = NULL;
rcu_read_unlock();
return block;
}
static struct tcf_chain *
__tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
{
mutex_lock(&block->lock);
if (chain)
chain = list_is_last(&chain->list, &block->chain_list) ?
NULL : list_next_entry(chain, list);
else
chain = list_first_entry_or_null(&block->chain_list,
struct tcf_chain, list);
/* skip all action-only chains */
while (chain && tcf_chain_held_by_acts_only(chain))
chain = list_is_last(&chain->list, &block->chain_list) ?
NULL : list_next_entry(chain, list);
if (chain)
tcf_chain_hold(chain);
mutex_unlock(&block->lock);
return chain;
}
/* Function to be used by all clients that want to iterate over all chains on
* block. It properly obtains block->lock and takes reference to chain before
* returning it. Users of this function must be tolerant to concurrent chain
* insertion/deletion or ensure that no concurrent chain modification is
* possible. Note that all netlink dump callbacks cannot guarantee to provide
* consistent dump because rtnl lock is released each time skb is filled with
* data and sent to user-space.
*/
struct tcf_chain *
tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
{
struct tcf_chain *chain_next = __tcf_get_next_chain(block, chain);
if (chain)
tcf_chain_put(chain);
return chain_next;
}
EXPORT_SYMBOL(tcf_get_next_chain);
static struct tcf_proto *
__tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
{
u32 prio = 0;
ASSERT_RTNL();
mutex_lock(&chain->filter_chain_lock);
if (!tp) {
tp = tcf_chain_dereference(chain->filter_chain, chain);
} else if (tcf_proto_is_deleting(tp)) {
/* 'deleting' flag is set and chain->filter_chain_lock was
* unlocked, which means next pointer could be invalid. Restart
* search.
*/
prio = tp->prio + 1;
tp = tcf_chain_dereference(chain->filter_chain, chain);
for (; tp; tp = tcf_chain_dereference(tp->next, chain))
if (!tp->deleting && tp->prio >= prio)
break;
} else {
tp = tcf_chain_dereference(tp->next, chain);
}
if (tp)
tcf_proto_get(tp);
mutex_unlock(&chain->filter_chain_lock);
return tp;
}
/* Function to be used by all clients that want to iterate over all tp's on
* chain. Users of this function must be tolerant to concurrent tp
* insertion/deletion or ensure that no concurrent chain modification is
* possible. Note that all netlink dump callbacks cannot guarantee to provide
* consistent dump because rtnl lock is released each time skb is filled with
* data and sent to user-space.
*/
struct tcf_proto *
tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
{
struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp);
if (tp)
tcf_proto_put(tp, true, NULL);
return tp_next;
}
EXPORT_SYMBOL(tcf_get_next_proto);
static void tcf_block_flush_all_chains(struct tcf_block *block, bool rtnl_held)
{
struct tcf_chain *chain;
/* Last reference to block. At this point chains cannot be added or
* removed concurrently.
*/
for (chain = tcf_get_next_chain(block, NULL);
chain;
chain = tcf_get_next_chain(block, chain)) {
tcf_chain_put_explicitly_created(chain);
tcf_chain_flush(chain, rtnl_held);
}
}
/* Lookup Qdisc and increments its reference counter.
* Set parent, if necessary.
*/
static int __tcf_qdisc_find(struct net *net, struct Qdisc **q,
u32 *parent, int ifindex, bool rtnl_held,
struct netlink_ext_ack *extack)
{
const struct Qdisc_class_ops *cops;
struct net_device *dev;
int err = 0;
if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
return 0;
rcu_read_lock();
/* Find link */
dev = dev_get_by_index_rcu(net, ifindex);
if (!dev) {
rcu_read_unlock();
return -ENODEV;
}
/* Find qdisc */
if (!*parent) {
*q = dev->qdisc;
*parent = (*q)->handle;
} else {
*q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
if (!*q) {
NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
err = -EINVAL;
goto errout_rcu;
}
}
*q = qdisc_refcount_inc_nz(*q);
if (!*q) {
NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
err = -EINVAL;
goto errout_rcu;
}
/* Is it classful? */
cops = (*q)->ops->cl_ops;
if (!cops) {
NL_SET_ERR_MSG(extack, "Qdisc not classful");
err = -EINVAL;
goto errout_qdisc;
}
if (!cops->tcf_block) {
NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
err = -EOPNOTSUPP;
goto errout_qdisc;
}
errout_rcu:
/* At this point we know that qdisc is not noop_qdisc,
* which means that qdisc holds a reference to net_device
* and we hold a reference to qdisc, so it is safe to release
* rcu read lock.
*/
rcu_read_unlock();
return err;
errout_qdisc:
rcu_read_unlock();
if (rtnl_held)
qdisc_put(*q);
else
qdisc_put_unlocked(*q);
*q = NULL;
return err;
}
static int __tcf_qdisc_cl_find(struct Qdisc *q, u32 parent, unsigned long *cl,
int ifindex, struct netlink_ext_ack *extack)
{
if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
return 0;
/* Do we search for filter, attached to class? */
if (TC_H_MIN(parent)) {
const struct Qdisc_class_ops *cops = q->ops->cl_ops;
*cl = cops->find(q, parent);
if (*cl == 0) {
NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
return -ENOENT;
}
}
return 0;
}
static struct tcf_block *__tcf_block_find(struct net *net, struct Qdisc *q,
unsigned long cl, int ifindex,
u32 block_index,
struct netlink_ext_ack *extack)
{
struct tcf_block *block;
if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
block = tcf_block_refcnt_get(net, block_index);
if (!block) {
NL_SET_ERR_MSG(extack, "Block of given index was not found");
return ERR_PTR(-EINVAL);
}
} else {
const struct Qdisc_class_ops *cops = q->ops->cl_ops;
block = cops->tcf_block(q, cl, extack);
if (!block)
return ERR_PTR(-EINVAL);
if (tcf_block_shared(block)) {
NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
return ERR_PTR(-EOPNOTSUPP);
}
/* Always take reference to block in order to support execution
* of rules update path of cls API without rtnl lock. Caller
* must release block when it is finished using it. 'if' block
* of this conditional obtain reference to block by calling
* tcf_block_refcnt_get().
*/
refcount_inc(&block->refcnt);
}
return block;
}
static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
struct tcf_block_ext_info *ei, bool rtnl_held)
{
if (refcount_dec_and_mutex_lock(&block->refcnt, &block->lock)) {
/* Flushing/putting all chains will cause the block to be
* deallocated when last chain is freed. However, if chain_list
* is empty, block has to be manually deallocated. After block
* reference counter reached 0, it is no longer possible to
* increment it or add new chains to block.
*/
bool free_block = list_empty(&block->chain_list);
mutex_unlock(&block->lock);
if (tcf_block_shared(block))
tcf_block_remove(block, block->net);
if (q)
tcf_block_offload_unbind(block, q, ei);
if (free_block)
tcf_block_destroy(block);
else
tcf_block_flush_all_chains(block, rtnl_held);
} else if (q) {
tcf_block_offload_unbind(block, q, ei);
}
}
static void tcf_block_refcnt_put(struct tcf_block *block, bool rtnl_held)
{
__tcf_block_put(block, NULL, NULL, rtnl_held);
}
/* Find tcf block.
* Set q, parent, cl when appropriate.
*/
static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
u32 *parent, unsigned long *cl,
int ifindex, u32 block_index,
struct netlink_ext_ack *extack)
{
struct tcf_block *block;
int err = 0;
ASSERT_RTNL();
err = __tcf_qdisc_find(net, q, parent, ifindex, true, extack);
if (err)
goto errout;
err = __tcf_qdisc_cl_find(*q, *parent, cl, ifindex, extack);
if (err)
goto errout_qdisc;
block = __tcf_block_find(net, *q, *cl, ifindex, block_index, extack);
if (IS_ERR(block)) {
err = PTR_ERR(block);
goto errout_qdisc;
}
return block;
errout_qdisc:
if (*q)
qdisc_put(*q);
errout:
*q = NULL;
return ERR_PTR(err);
}
static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
bool rtnl_held)
{
if (!IS_ERR_OR_NULL(block))
tcf_block_refcnt_put(block, rtnl_held);
if (q) {
if (rtnl_held)
qdisc_put(q);
else
qdisc_put_unlocked(q);
}
}
struct tcf_block_owner_item {
struct list_head list;
struct Qdisc *q;
enum flow_block_binder_type binder_type;
};
static void
tcf_block_owner_netif_keep_dst(struct tcf_block *block,
struct Qdisc *q,
enum flow_block_binder_type binder_type)
{
if (block->keep_dst &&
binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS &&
binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS)
netif_keep_dst(qdisc_dev(q));
}
void tcf_block_netif_keep_dst(struct tcf_block *block)
{
struct tcf_block_owner_item *item;
block->keep_dst = true;
list_for_each_entry(item, &block->owner_list, list)
tcf_block_owner_netif_keep_dst(block, item->q,
item->binder_type);
}
EXPORT_SYMBOL(tcf_block_netif_keep_dst);
static int tcf_block_owner_add(struct tcf_block *block,
struct Qdisc *q,
enum flow_block_binder_type binder_type)
{
struct tcf_block_owner_item *item;
item = kmalloc(sizeof(*item), GFP_KERNEL);
if (!item)
return -ENOMEM;
item->q = q;
item->binder_type = binder_type;
list_add(&item->list, &block->owner_list);
return 0;
}
static void tcf_block_owner_del(struct tcf_block *block,
struct Qdisc *q,
enum flow_block_binder_type binder_type)
{
struct tcf_block_owner_item *item;
list_for_each_entry(item, &block->owner_list, list) {
if (item->q == q && item->binder_type == binder_type) {
list_del(&item->list);
kfree(item);
return;
}
}
WARN_ON(1);
}
int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
struct tcf_block_ext_info *ei,
struct netlink_ext_ack *extack)
{
struct net *net = qdisc_net(q);
struct tcf_block *block = NULL;
int err;
if (ei->block_index)
/* block_index not 0 means the shared block is requested */
block = tcf_block_refcnt_get(net, ei->block_index);
if (!block) {
block = tcf_block_create(net, q, ei->block_index, extack);
if (IS_ERR(block))
return PTR_ERR(block);
if (tcf_block_shared(block)) {
err = tcf_block_insert(block, net, extack);
if (err)
goto err_block_insert;
}
}
err = tcf_block_owner_add(block, q, ei->binder_type);
if (err)
goto err_block_owner_add;
tcf_block_owner_netif_keep_dst(block, q, ei->binder_type);
err = tcf_chain0_head_change_cb_add(block, ei, extack);
if (err)
goto err_chain0_head_change_cb_add;
err = tcf_block_offload_bind(block, q, ei, extack);
if (err)
goto err_block_offload_bind;
*p_block = block;
return 0;
err_block_offload_bind:
tcf_chain0_head_change_cb_del(block, ei);
err_chain0_head_change_cb_add:
tcf_block_owner_del(block, q, ei->binder_type);
err_block_owner_add:
err_block_insert:
tcf_block_refcnt_put(block, true);
return err;
}
EXPORT_SYMBOL(tcf_block_get_ext);
static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv)
{
struct tcf_proto __rcu **p_filter_chain = priv;
rcu_assign_pointer(*p_filter_chain, tp_head);
}
int tcf_block_get(struct tcf_block **p_block,
struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
struct netlink_ext_ack *extack)
{
struct tcf_block_ext_info ei = {
.chain_head_change = tcf_chain_head_change_dflt,
.chain_head_change_priv = p_filter_chain,
};
WARN_ON(!p_filter_chain);
return tcf_block_get_ext(p_block, q, &ei, extack);
}
EXPORT_SYMBOL(tcf_block_get);
/* XXX: Standalone actions are not allowed to jump to any chain, and bound
* actions should be all removed after flushing.
*/
void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
struct tcf_block_ext_info *ei)
{
if (!block)
return;
tcf_chain0_head_change_cb_del(block, ei);
tcf_block_owner_del(block, q, ei->binder_type);
__tcf_block_put(block, q, ei, true);
}
EXPORT_SYMBOL(tcf_block_put_ext);
void tcf_block_put(struct tcf_block *block)
{
struct tcf_block_ext_info ei = {0, };
if (!block)
return;
tcf_block_put_ext(block, block->q, &ei);
}
EXPORT_SYMBOL(tcf_block_put);
static int
tcf_block_playback_offloads(struct tcf_block *block, flow_setup_cb_t *cb,
void *cb_priv, bool add, bool offload_in_use,
struct netlink_ext_ack *extack)
{
struct tcf_chain *chain, *chain_prev;
struct tcf_proto *tp, *tp_prev;
int err;
lockdep_assert_held(&block->cb_lock);
for (chain = __tcf_get_next_chain(block, NULL);
chain;
chain_prev = chain,
chain = __tcf_get_next_chain(block, chain),
tcf_chain_put(chain_prev)) {
for (tp = __tcf_get_next_proto(chain, NULL); tp;
tp_prev = tp,
tp = __tcf_get_next_proto(chain, tp),
tcf_proto_put(tp_prev, true, NULL)) {
if (tp->ops->reoffload) {
err = tp->ops->reoffload(tp, add, cb, cb_priv,
extack);
if (err && add)
goto err_playback_remove;
} else if (add && offload_in_use) {
err = -EOPNOTSUPP;
NL_SET_ERR_MSG(extack, "Filter HW offload failed - classifier without re-offloading support");
goto err_playback_remove;
}
}
}
return 0;
err_playback_remove:
tcf_proto_put(tp, true, NULL);
tcf_chain_put(chain);
tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
extack);
return err;
}
static int tcf_block_bind(struct tcf_block *block,
struct flow_block_offload *bo)
{
struct flow_block_cb *block_cb, *next;
int err, i = 0;
lockdep_assert_held(&block->cb_lock);
list_for_each_entry(block_cb, &bo->cb_list, list) {
err = tcf_block_playback_offloads(block, block_cb->cb,
block_cb->cb_priv, true,
tcf_block_offload_in_use(block),
bo->extack);
if (err)
goto err_unroll;
if (!bo->unlocked_driver_cb)
block->lockeddevcnt++;
i++;
}
list_splice(&bo->cb_list, &block->flow_block.cb_list);
return 0;
err_unroll:
list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
if (i-- > 0) {
list_del(&block_cb->list);
tcf_block_playback_offloads(block, block_cb->cb,
block_cb->cb_priv, false,
tcf_block_offload_in_use(block),
NULL);
if (!bo->unlocked_driver_cb)
block->lockeddevcnt--;
}
flow_block_cb_free(block_cb);
}
return err;
}
static void tcf_block_unbind(struct tcf_block *block,
struct flow_block_offload *bo)
{
struct flow_block_cb *block_cb, *next;
lockdep_assert_held(&block->cb_lock);
list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
tcf_block_playback_offloads(block, block_cb->cb,
block_cb->cb_priv, false,
tcf_block_offload_in_use(block),
NULL);
list_del(&block_cb->list);
flow_block_cb_free(block_cb);
if (!bo->unlocked_driver_cb)
block->lockeddevcnt--;
}
}
static int tcf_block_setup(struct tcf_block *block,
struct flow_block_offload *bo)
{
int err;
switch (bo->command) {
case FLOW_BLOCK_BIND:
err = tcf_block_bind(block, bo);
break;
case FLOW_BLOCK_UNBIND:
err = 0;
tcf_block_unbind(block, bo);
break;
default:
WARN_ON_ONCE(1);
err = -EOPNOTSUPP;
}
return err;
}
/* Main classifier routine: scans classifier chain attached
* to this qdisc, (optionally) tests for protocol and asks
* specific classifiers.
*/
static inline int __tcf_classify(struct sk_buff *skb,
const struct tcf_proto *tp,
const struct tcf_proto *orig_tp,
struct tcf_result *res,
bool compat_mode,
u32 *last_executed_chain)
{
#ifdef CONFIG_NET_CLS_ACT
const int max_reclassify_loop = 4;
const struct tcf_proto *first_tp;
int limit = 0;
reclassify:
#endif
for (; tp; tp = rcu_dereference_bh(tp->next)) {
__be16 protocol = skb_protocol(skb, false);
int err;
if (tp->protocol != protocol &&
tp->protocol != htons(ETH_P_ALL))
continue;
err = tp->classify(skb, tp, res);
#ifdef CONFIG_NET_CLS_ACT
if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
first_tp = orig_tp;
*last_executed_chain = first_tp->chain->index;
goto reset;
} else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
first_tp = res->goto_tp;
*last_executed_chain = err & TC_ACT_EXT_VAL_MASK;
goto reset;
}
#endif
if (err >= 0)
return err;
}
return TC_ACT_UNSPEC; /* signal: continue lookup */
#ifdef CONFIG_NET_CLS_ACT
reset:
if (unlikely(limit++ >= max_reclassify_loop)) {
net_notice_ratelimited("%u: reclassify loop, rule prio %u, protocol %02x\n",
tp->chain->block->index,
tp->prio & 0xffff,
ntohs(tp->protocol));
return TC_ACT_SHOT;
}
tp = first_tp;
goto reclassify;
#endif
}
int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
struct tcf_result *res, bool compat_mode)
{
u32 last_executed_chain = 0;
return __tcf_classify(skb, tp, tp, res, compat_mode,
&last_executed_chain);
}
EXPORT_SYMBOL(tcf_classify);
int tcf_classify_ingress(struct sk_buff *skb,
const struct tcf_block *ingress_block,
const struct tcf_proto *tp,
struct tcf_result *res, bool compat_mode)
{
#if !IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
u32 last_executed_chain = 0;
return __tcf_classify(skb, tp, tp, res, compat_mode,
&last_executed_chain);
#else
u32 last_executed_chain = tp ? tp->chain->index : 0;
const struct tcf_proto *orig_tp = tp;
struct tc_skb_ext *ext;
int ret;
ext = skb_ext_find(skb, TC_SKB_EXT);
if (ext && ext->chain) {
struct tcf_chain *fchain;
fchain = tcf_chain_lookup_rcu(ingress_block, ext->chain);
if (!fchain)
return TC_ACT_SHOT;
/* Consume, so cloned/redirect skbs won't inherit ext */
skb_ext_del(skb, TC_SKB_EXT);
tp = rcu_dereference_bh(fchain->filter_chain);
last_executed_chain = fchain->index;
}
ret = __tcf_classify(skb, tp, orig_tp, res, compat_mode,
&last_executed_chain);
/* If we missed on some chain */
if (ret == TC_ACT_UNSPEC && last_executed_chain) {
ext = skb_ext_add(skb, TC_SKB_EXT);
if (WARN_ON_ONCE(!ext))
return TC_ACT_SHOT;
ext->chain = last_executed_chain;
ext->mru = qdisc_skb_cb(skb)->mru;
}
return ret;
#endif
}
EXPORT_SYMBOL(tcf_classify_ingress);
struct tcf_chain_info {
struct tcf_proto __rcu **pprev;
struct tcf_proto __rcu *next;
};
static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain *chain,
struct tcf_chain_info *chain_info)
{
return tcf_chain_dereference(*chain_info->pprev, chain);
}
static int tcf_chain_tp_insert(struct tcf_chain *chain,
struct tcf_chain_info *chain_info,
struct tcf_proto *tp)
{
if (chain->flushing)
return -EAGAIN;
if (*chain_info->pprev == chain->filter_chain)
tcf_chain0_head_change(chain, tp);
tcf_proto_get(tp);
RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
rcu_assign_pointer(*chain_info->pprev, tp);
return 0;
}
static void tcf_chain_tp_remove(struct tcf_chain *chain,
struct tcf_chain_info *chain_info,
struct tcf_proto *tp)
{
struct tcf_proto *next = tcf_chain_dereference(chain_info->next, chain);
tcf_proto_mark_delete(tp);
if (tp == chain->filter_chain)
tcf_chain0_head_change(chain, next);
RCU_INIT_POINTER(*chain_info->pprev, next);
}
static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
struct tcf_chain_info *chain_info,
u32 protocol, u32 prio,
bool prio_allocate);
/* Try to insert new proto.
* If proto with specified priority already exists, free new proto
* and return existing one.
*/
static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
struct tcf_proto *tp_new,
u32 protocol, u32 prio,
bool rtnl_held)
{
struct tcf_chain_info chain_info;
struct tcf_proto *tp;
int err = 0;
mutex_lock(&chain->filter_chain_lock);
if (tcf_proto_exists_destroying(chain, tp_new)) {
mutex_unlock(&chain->filter_chain_lock);
tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
return ERR_PTR(-EAGAIN);
}
tp = tcf_chain_tp_find(chain, &chain_info,
protocol, prio, false);
if (!tp)
err = tcf_chain_tp_insert(chain, &chain_info, tp_new);
mutex_unlock(&chain->filter_chain_lock);
if (tp) {
tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
tp_new = tp;
} else if (err) {
tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
tp_new = ERR_PTR(err);
}
return tp_new;
}
static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
struct tcf_proto *tp, bool rtnl_held,
struct netlink_ext_ack *extack)
{
struct tcf_chain_info chain_info;
struct tcf_proto *tp_iter;
struct tcf_proto **pprev;
struct tcf_proto *next;
mutex_lock(&chain->filter_chain_lock);
/* Atomically find and remove tp from chain. */
for (pprev = &chain->filter_chain;
(tp_iter = tcf_chain_dereference(*pprev, chain));
pprev = &tp_iter->next) {
if (tp_iter == tp) {
chain_info.pprev = pprev;
chain_info.next = tp_iter->next;
WARN_ON(tp_iter->deleting);
break;
}
}
/* Verify that tp still exists and no new filters were inserted
* concurrently.
* Mark tp for deletion if it is empty.
*/
if (!tp_iter || !tcf_proto_check_delete(tp)) {
mutex_unlock(&chain->filter_chain_lock);
return;
}
tcf_proto_signal_destroying(chain, tp);
next = tcf_chain_dereference(chain_info.next, chain);
if (tp == chain->filter_chain)
tcf_chain0_head_change(chain, next);
RCU_INIT_POINTER(*chain_info.pprev, next);
mutex_unlock(&chain->filter_chain_lock);
tcf_proto_put(tp, rtnl_held, extack);
}
static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
struct tcf_chain_info *chain_info,
u32 protocol, u32 prio,
bool prio_allocate)
{
struct tcf_proto **pprev;
struct tcf_proto *tp;
/* Check the chain for existence of proto-tcf with this priority */
for (pprev = &chain->filter_chain;
(tp = tcf_chain_dereference(*pprev, chain));
pprev = &tp->next) {
if (tp->prio >= prio) {
if (tp->prio == prio) {
if (prio_allocate ||
(tp->protocol != protocol && protocol))
return ERR_PTR(-EINVAL);
} else {
tp = NULL;
}
break;
}
}
chain_info->pprev = pprev;
if (tp) {
chain_info->next = tp->next;
tcf_proto_get(tp);
} else {
chain_info->next = NULL;
}
return tp;
}
static int tcf_fill_node(struct net *net, struct sk_buff *skb,
struct tcf_proto *tp, struct tcf_block *block,
struct Qdisc *q, u32 parent, void *fh,
u32 portid, u32 seq, u16 flags, int event,
bool terse_dump, bool rtnl_held)
{
struct tcmsg *tcm;
struct nlmsghdr *nlh;
unsigned char *b = skb_tail_pointer(skb);
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
if (!nlh)
goto out_nlmsg_trim;
tcm = nlmsg_data(nlh);
tcm->tcm_family = AF_UNSPEC;
tcm->tcm__pad1 = 0;
tcm->tcm__pad2 = 0;
if (q) {
tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
tcm->tcm_parent = parent;
} else {
tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
tcm->tcm_block_index = block->index;
}
tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
goto nla_put_failure;
if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
goto nla_put_failure;
if (!fh) {
tcm->tcm_handle = 0;
} else if (terse_dump) {
if (tp->ops->terse_dump) {
if (tp->ops->terse_dump(net, tp, fh, skb, tcm,
rtnl_held) < 0)
goto nla_put_failure;
} else {
goto cls_op_not_supp;
}
} else {
if (tp->ops->dump &&
tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
goto nla_put_failure;
}
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
return skb->len;
out_nlmsg_trim:
nla_put_failure:
cls_op_not_supp:
nlmsg_trim(skb, b);
return -1;
}
static int tfilter_notify(struct net *net, struct sk_buff *oskb,
struct nlmsghdr *n, struct tcf_proto *tp,
struct tcf_block *block, struct Qdisc *q,
u32 parent, void *fh, int event, bool unicast,
bool rtnl_held)
{
struct sk_buff *skb;
u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
int err = 0;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return -ENOBUFS;
if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
n->nlmsg_seq, n->nlmsg_flags, event,
false, rtnl_held) <= 0) {
kfree_skb(skb);
return -EINVAL;
}
if (unicast)
err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
else
err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
n->nlmsg_flags & NLM_F_ECHO);
if (err > 0)
err = 0;
return err;
}
static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
struct nlmsghdr *n, struct tcf_proto *tp,
struct tcf_block *block, struct Qdisc *q,
u32 parent, void *fh, bool unicast, bool *last,
bool rtnl_held, struct netlink_ext_ack *extack)
{
struct sk_buff *skb;
u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
int err;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return -ENOBUFS;
if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
false, rtnl_held) <= 0) {
NL_SET_ERR_MSG(extack, "Failed to build del event notification");
kfree_skb(skb);
return -EINVAL;
}
err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
if (err) {
kfree_skb(skb);
return err;
}
if (unicast)
err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
else
err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
n->nlmsg_flags & NLM_F_ECHO);
if (err < 0)
NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
if (err > 0)
err = 0;
return err;
}
static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
struct tcf_block *block, struct Qdisc *q,
u32 parent, struct nlmsghdr *n,
struct tcf_chain *chain, int event)
{
struct tcf_proto *tp;
for (tp = tcf_get_next_proto(chain, NULL);
tp; tp = tcf_get_next_proto(chain, tp))
tfilter_notify(net, oskb, n, tp, block,
q, parent, NULL, event, false, true);
}
static void tfilter_put(struct tcf_proto *tp, void *fh)
{
if (tp->ops->put && fh)
tp->ops->put(tp, fh);
}
static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct nlattr *tca[TCA_MAX + 1];
char name[IFNAMSIZ];
struct tcmsg *t;
u32 protocol;
u32 prio;
bool prio_allocate;
u32 parent;
u32 chain_index;
struct Qdisc *q = NULL;
struct tcf_chain_info chain_info;
struct tcf_chain *chain = NULL;
struct tcf_block *block;
struct tcf_proto *tp;
unsigned long cl;
void *fh;
int err;
int tp_created;
bool rtnl_held = false;
if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
return -EPERM;
replay:
tp_created = 0;
err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
rtm_tca_policy, extack);
if (err < 0)
return err;
t = nlmsg_data(n);
protocol = TC_H_MIN(t->tcm_info);
prio = TC_H_MAJ(t->tcm_info);
prio_allocate = false;
parent = t->tcm_parent;
tp = NULL;
cl = 0;
block = NULL;
if (prio == 0) {
/* If no priority is provided by the user,
* we allocate one.
*/
if (n->nlmsg_flags & NLM_F_CREATE) {
prio = TC_H_MAKE(0x80000000U, 0U);
prio_allocate = true;
} else {
NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
return -ENOENT;
}
}
/* Find head of filter chain. */
err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
if (err)
return err;
if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
err = -EINVAL;
goto errout;
}
/* Take rtnl mutex if rtnl_held was set to true on previous iteration,
* block is shared (no qdisc found), qdisc is not unlocked, classifier
* type is not specified, classifier is not unlocked.
*/
if (rtnl_held ||
(q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
!tcf_proto_is_unlocked(name)) {
rtnl_held = true;
rtnl_lock();
}
err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
if (err)
goto errout;
block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
extack);
if (IS_ERR(block)) {
err = PTR_ERR(block);
goto errout;
}
block->classid = parent;
chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
if (chain_index > TC_ACT_EXT_VAL_MASK) {
NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
err = -EINVAL;
goto errout;
}
chain = tcf_chain_get(block, chain_index, true);
if (!chain) {
NL_SET_ERR_MSG(extack, "Cannot create specified filter chain");
err = -ENOMEM;
goto errout;
}
mutex_lock(&chain->filter_chain_lock);
tp = tcf_chain_tp_find(chain, &chain_info, protocol,
prio, prio_allocate);
if (IS_ERR(tp)) {
NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
err = PTR_ERR(tp);
goto errout_locked;
}
if (tp == NULL) {
struct tcf_proto *tp_new = NULL;
if (chain->flushing) {
err = -EAGAIN;
goto errout_locked;
}
/* Proto-tcf does not exist, create new one */
if (tca[TCA_KIND] == NULL || !protocol) {
NL_SET_ERR_MSG(extack, "Filter kind and protocol must be specified");
err = -EINVAL;
goto errout_locked;
}
if (!(n->nlmsg_flags & NLM_F_CREATE)) {
NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
err = -ENOENT;
goto errout_locked;
}
if (prio_allocate)
prio = tcf_auto_prio(tcf_chain_tp_prev(chain,
&chain_info));
mutex_unlock(&chain->filter_chain_lock);
tp_new = tcf_proto_create(name, protocol, prio, chain,
rtnl_held, extack);
if (IS_ERR(tp_new)) {
err = PTR_ERR(tp_new);
goto errout_tp;
}
tp_created = 1;
tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio,
rtnl_held);
if (IS_ERR(tp)) {
err = PTR_ERR(tp);
goto errout_tp;
}
} else {
mutex_unlock(&chain->filter_chain_lock);
}
if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
err = -EINVAL;
goto errout;
}
fh = tp->ops->get(tp, t->tcm_handle);
if (!fh) {
if (!(n->nlmsg_flags & NLM_F_CREATE)) {
NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
err = -ENOENT;
goto errout;
}
} else if (n->nlmsg_flags & NLM_F_EXCL) {
tfilter_put(tp, fh);
NL_SET_ERR_MSG(extack, "Filter already exists");
err = -EEXIST;
goto errout;
}
if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
err = -EINVAL;
goto errout;
}
err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE,
rtnl_held, extack);
if (err == 0) {
tfilter_notify(net, skb, n, tp, block, q, parent, fh,
RTM_NEWTFILTER, false, rtnl_held);
tfilter_put(tp, fh);
/* q pointer is NULL for shared blocks */
if (q)
q->flags &= ~TCQ_F_CAN_BYPASS;
}
errout:
if (err && tp_created)
tcf_chain_tp_delete_empty(chain, tp, rtnl_held, NULL);
errout_tp:
if (chain) {
if (tp && !IS_ERR(tp))
tcf_proto_put(tp, rtnl_held, NULL);
if (!tp_created)
tcf_chain_put(chain);
}
tcf_block_release(q, block, rtnl_held);
if (rtnl_held)
rtnl_unlock();
if (err == -EAGAIN) {
/* Take rtnl lock in case EAGAIN is caused by concurrent flush
* of target chain.
*/
rtnl_held = true;
/* Replay the request. */
goto replay;
}
return err;
errout_locked:
mutex_unlock(&chain->filter_chain_lock);
goto errout;
}
static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct nlattr *tca[TCA_MAX + 1];
char name[IFNAMSIZ];
struct tcmsg *t;
u32 protocol;
u32 prio;
u32 parent;
u32 chain_index;
struct Qdisc *q = NULL;
struct tcf_chain_info chain_info;
struct tcf_chain *chain = NULL;
struct tcf_block *block = NULL;
struct tcf_proto *tp = NULL;
unsigned long cl = 0;
void *fh = NULL;
int err;
bool rtnl_held = false;
if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
return -EPERM;
err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
rtm_tca_policy, extack);
if (err < 0)
return err;
t = nlmsg_data(n);
protocol = TC_H_MIN(t->tcm_info);
prio = TC_H_MAJ(t->tcm_info);
parent = t->tcm_parent;
if (prio == 0 && (protocol || t->tcm_handle || tca[TCA_KIND])) {
NL_SET_ERR_MSG(extack, "Cannot flush filters with protocol, handle or kind set");
return -ENOENT;
}
/* Find head of filter chain. */
err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
if (err)
return err;
if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
err = -EINVAL;
goto errout;
}
/* Take rtnl mutex if flushing whole chain, block is shared (no qdisc
* found), qdisc is not unlocked, classifier type is not specified,
* classifier is not unlocked.
*/
if (!prio ||
(q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
!tcf_proto_is_unlocked(name)) {
rtnl_held = true;
rtnl_lock();
}
err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
if (err)
goto errout;
block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
extack);
if (IS_ERR(block)) {
err = PTR_ERR(block);
goto errout;
}
chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
if (chain_index > TC_ACT_EXT_VAL_MASK) {
NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
err = -EINVAL;
goto errout;
}
chain = tcf_chain_get(block, chain_index, false);
if (!chain) {
/* User requested flush on non-existent chain. Nothing to do,
* so just return success.
*/
if (prio == 0) {
err = 0;
goto errout;
}
NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
err = -ENOENT;
goto errout;
}
if (prio == 0) {
tfilter_notify_chain(net, skb, block, q, parent, n,
chain, RTM_DELTFILTER);
tcf_chain_flush(chain, rtnl_held);
err = 0;
goto errout;
}
mutex_lock(&chain->filter_chain_lock);
tp = tcf_chain_tp_find(chain, &chain_info, protocol,
prio, false);
if (!tp || IS_ERR(tp)) {
NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
err = tp ? PTR_ERR(tp) : -ENOENT;
goto errout_locked;
} else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
err = -EINVAL;
goto errout_locked;
} else if (t->tcm_handle == 0) {
tcf_proto_signal_destroying(chain, tp);
tcf_chain_tp_remove(chain, &chain_info, tp);
mutex_unlock(&chain->filter_chain_lock);
tcf_proto_put(tp, rtnl_held, NULL);
tfilter_notify(net, skb, n, tp, block, q, parent, fh,
RTM_DELTFILTER, false, rtnl_held);
err = 0;
goto errout;
}
mutex_unlock(&chain->filter_chain_lock);
fh = tp->ops->get(tp, t->tcm_handle);
if (!fh) {
NL_SET_ERR_MSG(extack, "Specified filter handle not found");
err = -ENOENT;
} else {
bool last;
err = tfilter_del_notify(net, skb, n, tp, block,
q, parent, fh, false, &last,
rtnl_held, extack);
if (err)
goto errout;
if (last)
tcf_chain_tp_delete_empty(chain, tp, rtnl_held, extack);
}
errout:
if (chain) {
if (tp && !IS_ERR(tp))
tcf_proto_put(tp, rtnl_held, NULL);
tcf_chain_put(chain);
}
tcf_block_release(q, block, rtnl_held);
if (rtnl_held)
rtnl_unlock();
return err;
errout_locked:
mutex_unlock(&chain->filter_chain_lock);
goto errout;
}
static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct nlattr *tca[TCA_MAX + 1];
char name[IFNAMSIZ];
struct tcmsg *t;
u32 protocol;
u32 prio;
u32 parent;
u32 chain_index;
struct Qdisc *q = NULL;
struct tcf_chain_info chain_info;
struct tcf_chain *chain = NULL;
struct tcf_block *block = NULL;
struct tcf_proto *tp = NULL;
unsigned long cl = 0;
void *fh = NULL;
int err;
bool rtnl_held = false;
err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
rtm_tca_policy, extack);
if (err < 0)
return err;
t = nlmsg_data(n);
protocol = TC_H_MIN(t->tcm_info);
prio = TC_H_MAJ(t->tcm_info);
parent = t->tcm_parent;
if (prio == 0) {
NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
return -ENOENT;
}
/* Find head of filter chain. */
err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
if (err)
return err;
if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
err = -EINVAL;
goto errout;
}
/* Take rtnl mutex if block is shared (no qdisc found), qdisc is not
* unlocked, classifier type is not specified, classifier is not
* unlocked.
*/
if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
!tcf_proto_is_unlocked(name)) {
rtnl_held = true;
rtnl_lock();
}
err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
if (err)
goto errout;
block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
extack);
if (IS_ERR(block)) {
err = PTR_ERR(block);
goto errout;
}
chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
if (chain_index > TC_ACT_EXT_VAL_MASK) {
NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
err = -EINVAL;
goto errout;
}
chain = tcf_chain_get(block, chain_index, false);
if (!chain) {
NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
err = -EINVAL;
goto errout;
}
mutex_lock(&chain->filter_chain_lock);
tp = tcf_chain_tp_find(chain, &chain_info, protocol,
prio, false);
mutex_unlock(&chain->filter_chain_lock);
if (!tp || IS_ERR(tp)) {
NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
err = tp ? PTR_ERR(tp) : -ENOENT;
goto errout;
} else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
err = -EINVAL;
goto errout;
}
fh = tp->ops->get(tp, t->tcm_handle);
if (!fh) {
NL_SET_ERR_MSG(extack, "Specified filter handle not found");
err = -ENOENT;
} else {
err = tfilter_notify(net, skb, n, tp, block, q, parent,
fh, RTM_NEWTFILTER, true, rtnl_held);
if (err < 0)
NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
}
tfilter_put(tp, fh);
errout:
if (chain) {
if (tp && !IS_ERR(tp))
tcf_proto_put(tp, rtnl_held, NULL);
tcf_chain_put(chain);
}
tcf_block_release(q, block, rtnl_held);
if (rtnl_held)
rtnl_unlock();
return err;
}
struct tcf_dump_args {
struct tcf_walker w;
struct sk_buff *skb;
struct netlink_callback *cb;
struct tcf_block *block;
struct Qdisc *q;
u32 parent;
bool terse_dump;
};
static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
{
struct tcf_dump_args *a = (void *)arg;
struct net *net = sock_net(a->skb->sk);
return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
n, NETLINK_CB(a->cb->skb).portid,
a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
RTM_NEWTFILTER, a->terse_dump, true);
}
static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
struct sk_buff *skb, struct netlink_callback *cb,
long index_start, long *p_index, bool terse)
{
struct net *net = sock_net(skb->sk);
struct tcf_block *block = chain->block;
struct tcmsg *tcm = nlmsg_data(cb->nlh);
struct tcf_proto *tp, *tp_prev;
struct tcf_dump_args arg;
for (tp = __tcf_get_next_proto(chain, NULL);
tp;
tp_prev = tp,
tp = __tcf_get_next_proto(chain, tp),
tcf_proto_put(tp_prev, true, NULL),
(*p_index)++) {
if (*p_index < index_start)
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 (*p_index > index_start)
memset(&cb->args[1], 0,
sizeof(cb->args) - sizeof(cb->args[0]));
if (cb->args[1] == 0) {
if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
RTM_NEWTFILTER, false, true) <= 0)
goto errout;
cb->args[1] = 1;
}
if (!tp->ops->walk)
continue;
arg.w.fn = tcf_node_dump;
arg.skb = skb;
arg.cb = cb;
arg.block = block;
arg.q = q;
arg.parent = parent;
arg.w.stop = 0;
arg.w.skip = cb->args[1] - 1;
arg.w.count = 0;
arg.w.cookie = cb->args[2];
arg.terse_dump = terse;
tp->ops->walk(tp, &arg.w, true);
cb->args[2] = arg.w.cookie;
cb->args[1] = arg.w.count + 1;
if (arg.w.stop)
goto errout;
}
return true;
errout:
tcf_proto_put(tp, true, NULL);
return false;
}
static const struct nla_policy tcf_tfilter_dump_policy[TCA_MAX + 1] = {
[TCA_DUMP_FLAGS] = NLA_POLICY_BITFIELD32(TCA_DUMP_FLAGS_TERSE),
};
/* called with RTNL */
static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
{
struct tcf_chain *chain, *chain_prev;
struct net *net = sock_net(skb->sk);
struct nlattr *tca[TCA_MAX + 1];
struct Qdisc *q = NULL;
struct tcf_block *block;
struct tcmsg *tcm = nlmsg_data(cb->nlh);
bool terse_dump = false;
long index_start;
long index;
u32 parent;
int err;
if (nlmsg_len(cb->nlh) < sizeof(*tcm))
return skb->len;
err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
tcf_tfilter_dump_policy, cb->extack);
if (err)
return err;
if (tca[TCA_DUMP_FLAGS]) {
struct nla_bitfield32 flags =
nla_get_bitfield32(tca[TCA_DUMP_FLAGS]);
terse_dump = flags.value & TCA_DUMP_FLAGS_TERSE;
}
if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
if (!block)
goto out;
/* If we work with block index, q is NULL and parent value
* will never be used in the following code. The check
* in tcf_fill_node prevents it. However, compiler does not
* see that far, so set parent to zero to silence the warning
* about parent being uninitialized.
*/
parent = 0;
} else {
const struct Qdisc_class_ops *cops;
struct net_device *dev;
unsigned long cl = 0;
dev = __dev_get_by_index(net, tcm->tcm_ifindex);
if (!dev)
return skb->len;
parent = tcm->tcm_parent;
if (!parent)
q = dev->qdisc;
else
q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
if (!q)
goto out;
cops = q->ops->cl_ops;
if (!cops)
goto out;
if (!cops->tcf_block)
goto out;
if (TC_H_MIN(tcm->tcm_parent)) {
cl = cops->find(q, tcm->tcm_parent);
if (cl == 0)
goto out;
}
block = cops->tcf_block(q, cl, NULL);
if (!block)
goto out;
parent = block->classid;
if (tcf_block_shared(block))
q = NULL;
}
index_start = cb->args[0];
index = 0;
for (chain = __tcf_get_next_chain(block, NULL);
chain;
chain_prev = chain,
chain = __tcf_get_next_chain(block, chain),
tcf_chain_put(chain_prev)) {
if (tca[TCA_CHAIN] &&
nla_get_u32(tca[TCA_CHAIN]) != chain->index)
continue;
if (!tcf_chain_dump(chain, q, parent, skb, cb,
index_start, &index, terse_dump)) {
tcf_chain_put(chain);
err = -EMSGSIZE;
break;
}
}
if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
tcf_block_refcnt_put(block, true);
cb->args[0] = index;
out:
/* If we did no progress, the error (EMSGSIZE) is real */
if (skb->len == 0 && err)
return err;
return skb->len;
}
static int tc_chain_fill_node(const struct tcf_proto_ops *tmplt_ops,
void *tmplt_priv, u32 chain_index,
struct net *net, struct sk_buff *skb,
struct tcf_block *block,
u32 portid, u32 seq, u16 flags, int event)
{
unsigned char *b = skb_tail_pointer(skb);
const struct tcf_proto_ops *ops;
struct nlmsghdr *nlh;
struct tcmsg *tcm;
void *priv;
ops = tmplt_ops;
priv = tmplt_priv;
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
if (!nlh)
goto out_nlmsg_trim;
tcm = nlmsg_data(nlh);
tcm->tcm_family = AF_UNSPEC;
tcm->tcm__pad1 = 0;
tcm->tcm__pad2 = 0;
tcm->tcm_handle = 0;
if (block->q) {
tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
tcm->tcm_parent = block->q->handle;
} else {
tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
tcm->tcm_block_index = block->index;
}
if (nla_put_u32(skb, TCA_CHAIN, chain_index))
goto nla_put_failure;
if (ops) {
if (nla_put_string(skb, TCA_KIND, ops->kind))
goto nla_put_failure;
if (ops->tmplt_dump(skb, net, priv) < 0)
goto nla_put_failure;
}
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
return skb->len;
out_nlmsg_trim:
nla_put_failure:
nlmsg_trim(skb, b);
return -EMSGSIZE;
}
static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
u32 seq, u16 flags, int event, bool unicast)
{
u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
struct tcf_block *block = chain->block;
struct net *net = block->net;
struct sk_buff *skb;
int err = 0;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return -ENOBUFS;
if (tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
chain->index, net, skb, block, portid,
seq, flags, event) <= 0) {
kfree_skb(skb);
return -EINVAL;
}
if (unicast)
err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
else
err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
flags & NLM_F_ECHO);
if (err > 0)
err = 0;
return err;
}
static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
void *tmplt_priv, u32 chain_index,
struct tcf_block *block, struct sk_buff *oskb,
u32 seq, u16 flags, bool unicast)
{
u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
struct net *net = block->net;
struct sk_buff *skb;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return -ENOBUFS;
if (tc_chain_fill_node(tmplt_ops, tmplt_priv, chain_index, net, skb,
block, portid, seq, flags, RTM_DELCHAIN) <= 0) {
kfree_skb(skb);
return -EINVAL;
}
if (unicast)
return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
}
static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
struct nlattr **tca,
struct netlink_ext_ack *extack)
{
const struct tcf_proto_ops *ops;
char name[IFNAMSIZ];
void *tmplt_priv;
/* If kind is not set, user did not specify template. */
if (!tca[TCA_KIND])
return 0;
if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
NL_SET_ERR_MSG(extack, "Specified TC chain template name too long");
return -EINVAL;
}
ops = tcf_proto_lookup_ops(name, true, extack);
if (IS_ERR(ops))
return PTR_ERR(ops);
if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
return -EOPNOTSUPP;
}
tmplt_priv = ops->tmplt_create(net, chain, tca, extack);
if (IS_ERR(tmplt_priv)) {
module_put(ops->owner);
return PTR_ERR(tmplt_priv);
}
chain->tmplt_ops = ops;
chain->tmplt_priv = tmplt_priv;
return 0;
}
static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
void *tmplt_priv)
{
/* If template ops are set, no work to do for us. */
if (!tmplt_ops)
return;
tmplt_ops->tmplt_destroy(tmplt_priv);
module_put(tmplt_ops->owner);
}
/* Add/delete/get a chain */
static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct nlattr *tca[TCA_MAX + 1];
struct tcmsg *t;
u32 parent;
u32 chain_index;
struct Qdisc *q = NULL;
struct tcf_chain *chain = NULL;
struct tcf_block *block;
unsigned long cl;
int err;
if (n->nlmsg_type != RTM_GETCHAIN &&
!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
return -EPERM;
replay:
err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
rtm_tca_policy, extack);
if (err < 0)
return err;
t = nlmsg_data(n);
parent = t->tcm_parent;
cl = 0;
block = tcf_block_find(net, &q, &parent, &cl,
t->tcm_ifindex, t->tcm_block_index, extack);
if (IS_ERR(block))
return PTR_ERR(block);
chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
if (chain_index > TC_ACT_EXT_VAL_MASK) {
NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
err = -EINVAL;
goto errout_block;
}
mutex_lock(&block->lock);
chain = tcf_chain_lookup(block, chain_index);
if (n->nlmsg_type == RTM_NEWCHAIN) {
if (chain) {
if (tcf_chain_held_by_acts_only(chain)) {
/* The chain exists only because there is
* some action referencing it.
*/
tcf_chain_hold(chain);
} else {
NL_SET_ERR_MSG(extack, "Filter chain already exists");
err = -EEXIST;
goto errout_block_locked;
}
} else {
if (!(n->nlmsg_flags & NLM_F_CREATE)) {
NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain");
err = -ENOENT;
goto errout_block_locked;
}
chain = tcf_chain_create(block, chain_index);
if (!chain) {
NL_SET_ERR_MSG(extack, "Failed to create filter chain");
err = -ENOMEM;
goto errout_block_locked;
}
}
} else {
if (!chain || tcf_chain_held_by_acts_only(chain)) {
NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
err = -EINVAL;
goto errout_block_locked;
}
tcf_chain_hold(chain);
}
if (n->nlmsg_type == RTM_NEWCHAIN) {
/* Modifying chain requires holding parent block lock. In case
* the chain was successfully added, take a reference to the
* chain. This ensures that an empty chain does not disappear at
* the end of this function.
*/
tcf_chain_hold(chain);
chain->explicitly_created = true;
}
mutex_unlock(&block->lock);
switch (n->nlmsg_type) {
case RTM_NEWCHAIN:
err = tc_chain_tmplt_add(chain, net, tca, extack);
if (err) {
tcf_chain_put_explicitly_created(chain);
goto errout;
}
tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
RTM_NEWCHAIN, false);
break;
case RTM_DELCHAIN:
tfilter_notify_chain(net, skb, block, q, parent, n,
chain, RTM_DELTFILTER);
/* Flush the chain first as the user requested chain removal. */
tcf_chain_flush(chain, true);
/* In case the chain was successfully deleted, put a reference
* to the chain previously taken during addition.
*/
tcf_chain_put_explicitly_created(chain);
break;
case RTM_GETCHAIN:
err = tc_chain_notify(chain, skb, n->nlmsg_seq,
n->nlmsg_seq, n->nlmsg_type, true);
if (err < 0)
NL_SET_ERR_MSG(extack, "Failed to send chain notify message");
break;
default:
err = -EOPNOTSUPP;
NL_SET_ERR_MSG(extack, "Unsupported message type");
goto errout;
}
errout:
tcf_chain_put(chain);
errout_block:
tcf_block_release(q, block, true);
if (err == -EAGAIN)
/* Replay the request. */
goto replay;
return err;
errout_block_locked:
mutex_unlock(&block->lock);
goto errout_block;
}
/* called with RTNL */
static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct nlattr *tca[TCA_MAX + 1];
struct Qdisc *q = NULL;
struct tcf_block *block;
struct tcmsg *tcm = nlmsg_data(cb->nlh);
struct tcf_chain *chain;
long index_start;
long index;
int err;
if (nlmsg_len(cb->nlh) < sizeof(*tcm))
return skb->len;
err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
rtm_tca_policy, cb->extack);
if (err)
return err;
if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
if (!block)
goto out;
} else {
const struct Qdisc_class_ops *cops;
struct net_device *dev;
unsigned long cl = 0;
dev = __dev_get_by_index(net, tcm->tcm_ifindex);
if (!dev)
return skb->len;
if (!tcm->tcm_parent)
q = dev->qdisc;
else
q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
if (!q)
goto out;
cops = q->ops->cl_ops;
if (!cops)
goto out;
if (!cops->tcf_block)
goto out;
if (TC_H_MIN(tcm->tcm_parent)) {
cl = cops->find(q, tcm->tcm_parent);
if (cl == 0)
goto out;
}
block = cops->tcf_block(q, cl, NULL);
if (!block)
goto out;
if (tcf_block_shared(block))
q = NULL;
}
index_start = cb->args[0];
index = 0;
mutex_lock(&block->lock);
list_for_each_entry(chain, &block->chain_list, list) {
if ((tca[TCA_CHAIN] &&
nla_get_u32(tca[TCA_CHAIN]) != chain->index))
continue;
if (index < index_start) {
index++;
continue;
}
if (tcf_chain_held_by_acts_only(chain))
continue;
err = tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
chain->index, net, skb, block,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
RTM_NEWCHAIN);
if (err <= 0)
break;
index++;
}
mutex_unlock(&block->lock);
if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
tcf_block_refcnt_put(block, true);
cb->args[0] = index;
out:
/* If we did no progress, the error (EMSGSIZE) is real */
if (skb->len == 0 && err)
return err;
return skb->len;
}
void tcf_exts_destroy(struct tcf_exts *exts)
{
#ifdef CONFIG_NET_CLS_ACT
if (exts->actions) {
tcf_action_destroy(exts->actions, TCA_ACT_UNBIND);
kfree(exts->actions);
}
exts->nr_actions = 0;
#endif
}
EXPORT_SYMBOL(tcf_exts_destroy);
int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr,
bool rtnl_held, struct netlink_ext_ack *extack)
{
#ifdef CONFIG_NET_CLS_ACT
{
struct tc_action *act;
size_t attr_size = 0;
if (exts->police && tb[exts->police]) {
act = tcf_action_init_1(net, tp, tb[exts->police],
rate_tlv, "police", ovr,
TCA_ACT_BIND, rtnl_held,
extack);
if (IS_ERR(act))
return PTR_ERR(act);
act->type = exts->type = TCA_OLD_COMPAT;
exts->actions[0] = act;
exts->nr_actions = 1;
} else if (exts->action && tb[exts->action]) {
int err;
err = tcf_action_init(net, tp, tb[exts->action],
rate_tlv, NULL, ovr, TCA_ACT_BIND,
exts->actions, &attr_size,
rtnl_held, extack);
if (err < 0)
return err;
exts->nr_actions = err;
}
}
#else
if ((exts->action && tb[exts->action]) ||
(exts->police && tb[exts->police])) {
NL_SET_ERR_MSG(extack, "Classifier actions are not supported per compile options (CONFIG_NET_CLS_ACT)");
return -EOPNOTSUPP;
}
#endif
return 0;
}
EXPORT_SYMBOL(tcf_exts_validate);
void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
{
#ifdef CONFIG_NET_CLS_ACT
struct tcf_exts old = *dst;
*dst = *src;
tcf_exts_destroy(&old);
#endif
}
EXPORT_SYMBOL(tcf_exts_change);
#ifdef CONFIG_NET_CLS_ACT
static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
{
if (exts->nr_actions == 0)
return NULL;
else
return exts->actions[0];
}
#endif
int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
{
#ifdef CONFIG_NET_CLS_ACT
struct nlattr *nest;
if (exts->action && tcf_exts_has_actions(exts)) {
/*
* 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
*/
if (exts->type != TCA_OLD_COMPAT) {
nest = nla_nest_start_noflag(skb, exts->action);
if (nest == NULL)
goto nla_put_failure;
if (tcf_action_dump(skb, exts->actions, 0, 0, false)
< 0)
goto nla_put_failure;
nla_nest_end(skb, nest);
} else if (exts->police) {
struct tc_action *act = tcf_exts_first_act(exts);
nest = nla_nest_start_noflag(skb, exts->police);
if (nest == NULL || !act)
goto nla_put_failure;
if (tcf_action_dump_old(skb, act, 0, 0) < 0)
goto nla_put_failure;
nla_nest_end(skb, nest);
}
}
return 0;
nla_put_failure:
nla_nest_cancel(skb, nest);
return -1;
#else
return 0;
#endif
}
EXPORT_SYMBOL(tcf_exts_dump);
int tcf_exts_terse_dump(struct sk_buff *skb, struct tcf_exts *exts)
{
#ifdef CONFIG_NET_CLS_ACT
struct nlattr *nest;
if (!exts->action || !tcf_exts_has_actions(exts))
return 0;
nest = nla_nest_start_noflag(skb, exts->action);
if (!nest)
goto nla_put_failure;
if (tcf_action_dump(skb, exts->actions, 0, 0, true) < 0)
goto nla_put_failure;
nla_nest_end(skb, nest);
return 0;
nla_put_failure:
nla_nest_cancel(skb, nest);
return -1;
#else
return 0;
#endif
}
EXPORT_SYMBOL(tcf_exts_terse_dump);
int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
{
#ifdef CONFIG_NET_CLS_ACT
struct tc_action *a = tcf_exts_first_act(exts);
if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
return -1;
#endif
return 0;
}
EXPORT_SYMBOL(tcf_exts_dump_stats);
static void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
{
if (*flags & TCA_CLS_FLAGS_IN_HW)
return;
*flags |= TCA_CLS_FLAGS_IN_HW;
atomic_inc(&block->offloadcnt);
}
static void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
{
if (!(*flags & TCA_CLS_FLAGS_IN_HW))
return;
*flags &= ~TCA_CLS_FLAGS_IN_HW;
atomic_dec(&block->offloadcnt);
}
static void tc_cls_offload_cnt_update(struct tcf_block *block,
struct tcf_proto *tp, u32 *cnt,
u32 *flags, u32 diff, bool add)
{
lockdep_assert_held(&block->cb_lock);
spin_lock(&tp->lock);
if (add) {
if (!*cnt)
tcf_block_offload_inc(block, flags);
*cnt += diff;
} else {
*cnt -= diff;
if (!*cnt)
tcf_block_offload_dec(block, flags);
}
spin_unlock(&tp->lock);
}
static void
tc_cls_offload_cnt_reset(struct tcf_block *block, struct tcf_proto *tp,
u32 *cnt, u32 *flags)
{
lockdep_assert_held(&block->cb_lock);
spin_lock(&tp->lock);
tcf_block_offload_dec(block, flags);
*cnt = 0;
spin_unlock(&tp->lock);
}
static int
__tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
void *type_data, bool err_stop)
{
struct flow_block_cb *block_cb;
int ok_count = 0;
int err;
list_for_each_entry(block_cb, &block->flow_block.cb_list, list) {
err = block_cb->cb(type, type_data, block_cb->cb_priv);
if (err) {
if (err_stop)
return err;
} else {
ok_count++;
}
}
return ok_count;
}
int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
void *type_data, bool err_stop, bool rtnl_held)
{
bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
int ok_count;
retry:
if (take_rtnl)
rtnl_lock();
down_read(&block->cb_lock);
/* Need to obtain rtnl lock if block is bound to devs that require it.
* In block bind code cb_lock is obtained while holding rtnl, so we must
* obtain the locks in same order here.
*/
if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
up_read(&block->cb_lock);
take_rtnl = true;
goto retry;
}
ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
up_read(&block->cb_lock);
if (take_rtnl)
rtnl_unlock();
return ok_count;
}
EXPORT_SYMBOL(tc_setup_cb_call);
/* Non-destructive filter add. If filter that wasn't already in hardware is
* successfully offloaded, increment block offloads counter. On failure,
* previously offloaded filter is considered to be intact and offloads counter
* is not decremented.
*/
int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
enum tc_setup_type type, void *type_data, bool err_stop,
u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
{
bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
int ok_count;
retry:
if (take_rtnl)
rtnl_lock();
down_read(&block->cb_lock);
/* Need to obtain rtnl lock if block is bound to devs that require it.
* In block bind code cb_lock is obtained while holding rtnl, so we must
* obtain the locks in same order here.
*/
if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
up_read(&block->cb_lock);
take_rtnl = true;
goto retry;
}
/* Make sure all netdevs sharing this block are offload-capable. */
if (block->nooffloaddevcnt && err_stop) {
ok_count = -EOPNOTSUPP;
goto err_unlock;
}
ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
if (ok_count < 0)
goto err_unlock;
if (tp->ops->hw_add)
tp->ops->hw_add(tp, type_data);
if (ok_count > 0)
tc_cls_offload_cnt_update(block, tp, in_hw_count, flags,
ok_count, true);
err_unlock:
up_read(&block->cb_lock);
if (take_rtnl)
rtnl_unlock();
return ok_count < 0 ? ok_count : 0;
}
EXPORT_SYMBOL(tc_setup_cb_add);
/* Destructive filter replace. If filter that wasn't already in hardware is
* successfully offloaded, increment block offload counter. On failure,
* previously offloaded filter is considered to be destroyed and offload counter
* is decremented.
*/
int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp,
enum tc_setup_type type, void *type_data, bool err_stop,
u32 *old_flags, unsigned int *old_in_hw_count,
u32 *new_flags, unsigned int *new_in_hw_count,
bool rtnl_held)
{
bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
int ok_count;
retry:
if (take_rtnl)
rtnl_lock();
down_read(&block->cb_lock);
/* Need to obtain rtnl lock if block is bound to devs that require it.
* In block bind code cb_lock is obtained while holding rtnl, so we must
* obtain the locks in same order here.
*/
if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
up_read(&block->cb_lock);
take_rtnl = true;
goto retry;
}
/* Make sure all netdevs sharing this block are offload-capable. */
if (block->nooffloaddevcnt && err_stop) {
ok_count = -EOPNOTSUPP;
goto err_unlock;
}
tc_cls_offload_cnt_reset(block, tp, old_in_hw_count, old_flags);
if (tp->ops->hw_del)
tp->ops->hw_del(tp, type_data);
ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
if (ok_count < 0)
goto err_unlock;
if (tp->ops->hw_add)
tp->ops->hw_add(tp, type_data);
if (ok_count > 0)
tc_cls_offload_cnt_update(block, tp, new_in_hw_count,
new_flags, ok_count, true);
err_unlock:
up_read(&block->cb_lock);
if (take_rtnl)
rtnl_unlock();
return ok_count < 0 ? ok_count : 0;
}
EXPORT_SYMBOL(tc_setup_cb_replace);
/* Destroy filter and decrement block offload counter, if filter was previously
* offloaded.
*/
int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp,
enum tc_setup_type type, void *type_data, bool err_stop,
u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
{
bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
int ok_count;
retry:
if (take_rtnl)
rtnl_lock();
down_read(&block->cb_lock);
/* Need to obtain rtnl lock if block is bound to devs that require it.
* In block bind code cb_lock is obtained while holding rtnl, so we must
* obtain the locks in same order here.
*/
if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
up_read(&block->cb_lock);
take_rtnl = true;
goto retry;
}
ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
tc_cls_offload_cnt_reset(block, tp, in_hw_count, flags);
if (tp->ops->hw_del)
tp->ops->hw_del(tp, type_data);
up_read(&block->cb_lock);
if (take_rtnl)
rtnl_unlock();
return ok_count < 0 ? ok_count : 0;
}
EXPORT_SYMBOL(tc_setup_cb_destroy);
int tc_setup_cb_reoffload(struct tcf_block *block, struct tcf_proto *tp,
bool add, flow_setup_cb_t *cb,
enum tc_setup_type type, void *type_data,
void *cb_priv, u32 *flags, unsigned int *in_hw_count)
{
int err = cb(type, type_data, cb_priv);
if (err) {
if (add && tc_skip_sw(*flags))
return err;
} else {
tc_cls_offload_cnt_update(block, tp, in_hw_count, flags, 1,
add);
}
return 0;
}
EXPORT_SYMBOL(tc_setup_cb_reoffload);
static int tcf_act_get_cookie(struct flow_action_entry *entry,
const struct tc_action *act)
{
struct tc_cookie *cookie;
int err = 0;
rcu_read_lock();
cookie = rcu_dereference(act->act_cookie);
if (cookie) {
entry->cookie = flow_action_cookie_create(cookie->data,
cookie->len,
GFP_ATOMIC);
if (!entry->cookie)
err = -ENOMEM;
}
rcu_read_unlock();
return err;
}
static void tcf_act_put_cookie(struct flow_action_entry *entry)
{
flow_action_cookie_destroy(entry->cookie);
}
void tc_cleanup_flow_action(struct flow_action *flow_action)
{
struct flow_action_entry *entry;
int i;
flow_action_for_each(i, entry, flow_action) {
tcf_act_put_cookie(entry);
if (entry->destructor)
entry->destructor(entry->destructor_priv);
}
}
EXPORT_SYMBOL(tc_cleanup_flow_action);
static void tcf_mirred_get_dev(struct flow_action_entry *entry,
const struct tc_action *act)
{
#ifdef CONFIG_NET_CLS_ACT
entry->dev = act->ops->get_dev(act, &entry->destructor);
if (!entry->dev)
return;
entry->destructor_priv = entry->dev;
#endif
}
static void tcf_tunnel_encap_put_tunnel(void *priv)
{
struct ip_tunnel_info *tunnel = priv;
kfree(tunnel);
}
static int tcf_tunnel_encap_get_tunnel(struct flow_action_entry *entry,
const struct tc_action *act)
{
entry->tunnel = tcf_tunnel_info_copy(act);
if (!entry->tunnel)
return -ENOMEM;
entry->destructor = tcf_tunnel_encap_put_tunnel;
entry->destructor_priv = entry->tunnel;
return 0;
}
static void tcf_sample_get_group(struct flow_action_entry *entry,
const struct tc_action *act)
{
#ifdef CONFIG_NET_CLS_ACT
entry->sample.psample_group =
act->ops->get_psample_group(act, &entry->destructor);
entry->destructor_priv = entry->sample.psample_group;
#endif
}
static void tcf_gate_entry_destructor(void *priv)
{
struct action_gate_entry *oe = priv;
kfree(oe);
}
static int tcf_gate_get_entries(struct flow_action_entry *entry,
const struct tc_action *act)
{
entry->gate.entries = tcf_gate_get_list(act);
if (!entry->gate.entries)
return -EINVAL;
entry->destructor = tcf_gate_entry_destructor;
entry->destructor_priv = entry->gate.entries;
return 0;
}
static enum flow_action_hw_stats tc_act_hw_stats(u8 hw_stats)
{
if (WARN_ON_ONCE(hw_stats > TCA_ACT_HW_STATS_ANY))
return FLOW_ACTION_HW_STATS_DONT_CARE;
else if (!hw_stats)
return FLOW_ACTION_HW_STATS_DISABLED;
return hw_stats;
}
int tc_setup_flow_action(struct flow_action *flow_action,
const struct tcf_exts *exts)
{
struct tc_action *act;
int i, j, k, err = 0;
BUILD_BUG_ON(TCA_ACT_HW_STATS_ANY != FLOW_ACTION_HW_STATS_ANY);
BUILD_BUG_ON(TCA_ACT_HW_STATS_IMMEDIATE != FLOW_ACTION_HW_STATS_IMMEDIATE);
BUILD_BUG_ON(TCA_ACT_HW_STATS_DELAYED != FLOW_ACTION_HW_STATS_DELAYED);
if (!exts)
return 0;
j = 0;
tcf_exts_for_each_action(i, act, exts) {
struct flow_action_entry *entry;
entry = &flow_action->entries[j];
spin_lock_bh(&act->tcfa_lock);
err = tcf_act_get_cookie(entry, act);
if (err)
goto err_out_locked;
entry->hw_stats = tc_act_hw_stats(act->hw_stats);
if (is_tcf_gact_ok(act)) {
entry->id = FLOW_ACTION_ACCEPT;
} else if (is_tcf_gact_shot(act)) {
entry->id = FLOW_ACTION_DROP;
} else if (is_tcf_gact_trap(act)) {
entry->id = FLOW_ACTION_TRAP;
} else if (is_tcf_gact_goto_chain(act)) {
entry->id = FLOW_ACTION_GOTO;
entry->chain_index = tcf_gact_goto_chain_index(act);
} else if (is_tcf_mirred_egress_redirect(act)) {
entry->id = FLOW_ACTION_REDIRECT;
tcf_mirred_get_dev(entry, act);
} else if (is_tcf_mirred_egress_mirror(act)) {
entry->id = FLOW_ACTION_MIRRED;
tcf_mirred_get_dev(entry, act);
} else if (is_tcf_mirred_ingress_redirect(act)) {
entry->id = FLOW_ACTION_REDIRECT_INGRESS;
tcf_mirred_get_dev(entry, act);
} else if (is_tcf_mirred_ingress_mirror(act)) {
entry->id = FLOW_ACTION_MIRRED_INGRESS;
tcf_mirred_get_dev(entry, act);
} else if (is_tcf_vlan(act)) {
switch (tcf_vlan_action(act)) {
case TCA_VLAN_ACT_PUSH:
entry->id = FLOW_ACTION_VLAN_PUSH;
entry->vlan.vid = tcf_vlan_push_vid(act);
entry->vlan.proto = tcf_vlan_push_proto(act);
entry->vlan.prio = tcf_vlan_push_prio(act);
break;
case TCA_VLAN_ACT_POP:
entry->id = FLOW_ACTION_VLAN_POP;
break;
case TCA_VLAN_ACT_MODIFY:
entry->id = FLOW_ACTION_VLAN_MANGLE;
entry->vlan.vid = tcf_vlan_push_vid(act);
entry->vlan.proto = tcf_vlan_push_proto(act);
entry->vlan.prio = tcf_vlan_push_prio(act);
break;
default:
err = -EOPNOTSUPP;
goto err_out_locked;
}
} else if (is_tcf_tunnel_set(act)) {
entry->id = FLOW_ACTION_TUNNEL_ENCAP;
err = tcf_tunnel_encap_get_tunnel(entry, act);
if (err)
goto err_out_locked;
} else if (is_tcf_tunnel_release(act)) {
entry->id = FLOW_ACTION_TUNNEL_DECAP;
} else if (is_tcf_pedit(act)) {
for (k = 0; k < tcf_pedit_nkeys(act); k++) {
switch (tcf_pedit_cmd(act, k)) {
case TCA_PEDIT_KEY_EX_CMD_SET:
entry->id = FLOW_ACTION_MANGLE;
break;
case TCA_PEDIT_KEY_EX_CMD_ADD:
entry->id = FLOW_ACTION_ADD;
break;
default:
err = -EOPNOTSUPP;
goto err_out_locked;
}
entry->mangle.htype = tcf_pedit_htype(act, k);
entry->mangle.mask = tcf_pedit_mask(act, k);
entry->mangle.val = tcf_pedit_val(act, k);
entry->mangle.offset = tcf_pedit_offset(act, k);
entry->hw_stats = tc_act_hw_stats(act->hw_stats);
entry = &flow_action->entries[++j];
}
} else if (is_tcf_csum(act)) {
entry->id = FLOW_ACTION_CSUM;
entry->csum_flags = tcf_csum_update_flags(act);
} else if (is_tcf_skbedit_mark(act)) {
entry->id = FLOW_ACTION_MARK;
entry->mark = tcf_skbedit_mark(act);
} else if (is_tcf_sample(act)) {
entry->id = FLOW_ACTION_SAMPLE;
entry->sample.trunc_size = tcf_sample_trunc_size(act);
entry->sample.truncate = tcf_sample_truncate(act);
entry->sample.rate = tcf_sample_rate(act);
tcf_sample_get_group(entry, act);
} else if (is_tcf_police(act)) {
entry->id = FLOW_ACTION_POLICE;
entry->police.burst = tcf_police_burst(act);
entry->police.rate_bytes_ps =
tcf_police_rate_bytes_ps(act);
entry->police.mtu = tcf_police_tcfp_mtu(act);
entry->police.index = act->tcfa_index;
} else if (is_tcf_ct(act)) {
entry->id = FLOW_ACTION_CT;
entry->ct.action = tcf_ct_action(act);
entry->ct.zone = tcf_ct_zone(act);
entry->ct.flow_table = tcf_ct_ft(act);
} else if (is_tcf_mpls(act)) {
switch (tcf_mpls_action(act)) {
case TCA_MPLS_ACT_PUSH:
entry->id = FLOW_ACTION_MPLS_PUSH;
entry->mpls_push.proto = tcf_mpls_proto(act);
entry->mpls_push.label = tcf_mpls_label(act);
entry->mpls_push.tc = tcf_mpls_tc(act);
entry->mpls_push.bos = tcf_mpls_bos(act);
entry->mpls_push.ttl = tcf_mpls_ttl(act);
break;
case TCA_MPLS_ACT_POP:
entry->id = FLOW_ACTION_MPLS_POP;
entry->mpls_pop.proto = tcf_mpls_proto(act);
break;
case TCA_MPLS_ACT_MODIFY:
entry->id = FLOW_ACTION_MPLS_MANGLE;
entry->mpls_mangle.label = tcf_mpls_label(act);
entry->mpls_mangle.tc = tcf_mpls_tc(act);
entry->mpls_mangle.bos = tcf_mpls_bos(act);
entry->mpls_mangle.ttl = tcf_mpls_ttl(act);
break;
default:
goto err_out_locked;
}
} else if (is_tcf_skbedit_ptype(act)) {
entry->id = FLOW_ACTION_PTYPE;
entry->ptype = tcf_skbedit_ptype(act);
} else if (is_tcf_skbedit_priority(act)) {
entry->id = FLOW_ACTION_PRIORITY;
entry->priority = tcf_skbedit_priority(act);
} else if (is_tcf_gate(act)) {
entry->id = FLOW_ACTION_GATE;
entry->gate.index = tcf_gate_index(act);
entry->gate.prio = tcf_gate_prio(act);
entry->gate.basetime = tcf_gate_basetime(act);
entry->gate.cycletime = tcf_gate_cycletime(act);
entry->gate.cycletimeext = tcf_gate_cycletimeext(act);
entry->gate.num_entries = tcf_gate_num_entries(act);
err = tcf_gate_get_entries(entry, act);
if (err)
goto err_out_locked;
} else {
err = -EOPNOTSUPP;
goto err_out_locked;
}
spin_unlock_bh(&act->tcfa_lock);
if (!is_tcf_pedit(act))
j++;
}
err_out:
if (err)
tc_cleanup_flow_action(flow_action);
return err;
err_out_locked:
spin_unlock_bh(&act->tcfa_lock);
goto err_out;
}
EXPORT_SYMBOL(tc_setup_flow_action);
unsigned int tcf_exts_num_actions(struct tcf_exts *exts)
{
unsigned int num_acts = 0;
struct tc_action *act;
int i;
tcf_exts_for_each_action(i, act, exts) {
if (is_tcf_pedit(act))
num_acts += tcf_pedit_nkeys(act);
else
num_acts++;
}
return num_acts;
}
EXPORT_SYMBOL(tcf_exts_num_actions);
#ifdef CONFIG_NET_CLS_ACT
static int tcf_qevent_parse_block_index(struct nlattr *block_index_attr,
u32 *p_block_index,
struct netlink_ext_ack *extack)
{
*p_block_index = nla_get_u32(block_index_attr);
if (!*p_block_index) {
NL_SET_ERR_MSG(extack, "Block number may not be zero");
return -EINVAL;
}
return 0;
}
int tcf_qevent_init(struct tcf_qevent *qe, struct Qdisc *sch,
enum flow_block_binder_type binder_type,
struct nlattr *block_index_attr,
struct netlink_ext_ack *extack)
{
u32 block_index;
int err;
if (!block_index_attr)
return 0;
err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
if (err)
return err;
if (!block_index)
return 0;
qe->info.binder_type = binder_type;
qe->info.chain_head_change = tcf_chain_head_change_dflt;
qe->info.chain_head_change_priv = &qe->filter_chain;
qe->info.block_index = block_index;
return tcf_block_get_ext(&qe->block, sch, &qe->info, extack);
}
EXPORT_SYMBOL(tcf_qevent_init);
void tcf_qevent_destroy(struct tcf_qevent *qe, struct Qdisc *sch)
{
if (qe->info.block_index)
tcf_block_put_ext(qe->block, sch, &qe->info);
}
EXPORT_SYMBOL(tcf_qevent_destroy);
int tcf_qevent_validate_change(struct tcf_qevent *qe, struct nlattr *block_index_attr,
struct netlink_ext_ack *extack)
{
u32 block_index;
int err;
if (!block_index_attr)
return 0;
err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
if (err)
return err;
/* Bounce newly-configured block or change in block. */
if (block_index != qe->info.block_index) {
NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
return -EINVAL;
}
return 0;
}
EXPORT_SYMBOL(tcf_qevent_validate_change);
struct sk_buff *tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, struct sk_buff *skb,
struct sk_buff **to_free, int *ret)
{
struct tcf_result cl_res;
struct tcf_proto *fl;
if (!qe->info.block_index)
return skb;
fl = rcu_dereference_bh(qe->filter_chain);
switch (tcf_classify(skb, fl, &cl_res, false)) {
case TC_ACT_SHOT:
qdisc_qstats_drop(sch);
__qdisc_drop(skb, to_free);
*ret = __NET_XMIT_BYPASS;
return NULL;
case TC_ACT_STOLEN:
case TC_ACT_QUEUED:
case TC_ACT_TRAP:
__qdisc_drop(skb, to_free);
*ret = __NET_XMIT_STOLEN;
return NULL;
case TC_ACT_REDIRECT:
skb_do_redirect(skb);
*ret = __NET_XMIT_STOLEN;
return NULL;
}
return skb;
}
EXPORT_SYMBOL(tcf_qevent_handle);
int tcf_qevent_dump(struct sk_buff *skb, int attr_name, struct tcf_qevent *qe)
{
if (!qe->info.block_index)
return 0;
return nla_put_u32(skb, attr_name, qe->info.block_index);
}
EXPORT_SYMBOL(tcf_qevent_dump);
#endif
static __net_init int tcf_net_init(struct net *net)
{
struct tcf_net *tn = net_generic(net, tcf_net_id);
spin_lock_init(&tn->idr_lock);
idr_init(&tn->idr);
return 0;
}
static void __net_exit tcf_net_exit(struct net *net)
{
struct tcf_net *tn = net_generic(net, tcf_net_id);
idr_destroy(&tn->idr);
}
static struct pernet_operations tcf_net_ops = {
.init = tcf_net_init,
.exit = tcf_net_exit,
.id = &tcf_net_id,
.size = sizeof(struct tcf_net),
};
static int __init tc_filter_init(void)
{
int err;
tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
if (!tc_filter_wq)
return -ENOMEM;
err = register_pernet_subsys(&tcf_net_ops);
if (err)
goto err_register_pernet_subsys;
rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
RTNL_FLAG_DOIT_UNLOCKED);
rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
RTNL_FLAG_DOIT_UNLOCKED);
rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED);
rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
tc_dump_chain, 0);
return 0;
err_register_pernet_subsys:
destroy_workqueue(tc_filter_wq);
return err;
}
subsys_initcall(tc_filter_init);
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