diff options
Diffstat (limited to 'net/sched/cls_api.c')
| -rw-r--r-- | net/sched/cls_api.c | 3785 |
1 files changed, 3785 insertions, 0 deletions
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c new file mode 100644 index 000000000..445ab1b05 --- /dev/null +++ b/net/sched/cls_api.c @@ -0,0 +1,3785 @@ +// 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> + +/* 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); + +#ifdef CONFIG_NET_CLS_ACT +DEFINE_STATIC_KEY_FALSE(tc_skb_ext_tc); +EXPORT_SYMBOL(tc_skb_ext_tc); + +void tc_skb_ext_tc_enable(void) +{ + static_branch_inc(&tc_skb_ext_tc); +} +EXPORT_SYMBOL(tc_skb_ext_tc_enable); + +void tc_skb_ext_tc_disable(void) +{ + static_branch_dec(&tc_skb_ext_tc); +} +EXPORT_SYMBOL(tc_skb_ext_tc_disable); +#endif + +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; + +void 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); + + WARN(rc, "unregister tc filter kind(%s) failed %d\n", ops->kind, 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, + struct netlink_ext_ack *extack); + +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, NULL); + + 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; + unsigned int refcnt, non_act_refcnt; + bool free_block = false; + 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; + non_act_refcnt = refcnt - chain->action_refcnt; + tmplt_ops = chain->tmplt_ops; + tmplt_priv = chain->tmplt_priv; + + if (non_act_refcnt == chain->explicitly_created && !by_act) { + if (non_act_refcnt == 0) + 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; + bo->cb_list_head = &flow_block->cb_list; + 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 = rcu_dereference(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) { + list_del(&block_cb->driver_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 = 16; + 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_block *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; + + if (block) { + ext = skb_ext_find(skb, TC_SKB_EXT); + + if (ext && ext->chain) { + struct tcf_chain *fchain; + + fchain = tcf_chain_lookup_rcu(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 (tc_skb_ext_tc_enabled()) { + /* If we missed on some chain */ + if (ret == TC_ACT_UNSPEC && last_executed_chain) { + struct tc_skb_cb *cb = tc_skb_cb(skb); + + ext = tc_skb_ext_alloc(skb); + if (WARN_ON_ONCE(!ext)) + return TC_ACT_SHOT; + ext->chain = last_executed_chain; + ext->mru = cb->mru; + ext->post_ct = cb->post_ct; + ext->post_ct_snat = cb->post_ct_snat; + ext->post_ct_dnat = cb->post_ct_dnat; + ext->zone = cb->zone; + } + } + + return ret; +#endif +} +EXPORT_SYMBOL(tcf_classify); + +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; + + RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info)); + if (*chain_info->pprev == chain->filter_chain) + tcf_chain0_head_change(chain, tp); + tcf_proto_get(tp); + 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 netlink_ext_ack *extack) +{ + 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; + } + + if (extack && extack->_msg && + nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg)) + 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 netlink_ext_ack *extack) +{ + 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, extack) <= 0) { + kfree_skb(skb); + return -EINVAL; + } + + if (unicast) + err = rtnl_unicast(skb, net, portid); + else + err = rtnetlink_send(skb, net, portid, RTNLGRP_TC, + n->nlmsg_flags & NLM_F_ECHO); + 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, extack) <= 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 = rtnl_unicast(skb, net, portid); + 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"); + + 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 netlink_ext_ack *extack) +{ + 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, extack); +} + +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; + struct tcf_chain_info chain_info; + struct tcf_chain *chain; + struct tcf_block *block; + struct tcf_proto *tp; + unsigned long cl; + void *fh; + int err; + int tp_created; + bool rtnl_held = false; + u32 flags; + +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; + q = NULL; + chain = NULL; + flags = 0; + + 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) { + tfilter_put(tp, fh); + NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind"); + err = -EINVAL; + goto errout; + } + + if (!(n->nlmsg_flags & NLM_F_CREATE)) + flags |= TCA_ACT_FLAGS_REPLACE; + if (!rtnl_held) + flags |= TCA_ACT_FLAGS_NO_RTNL; + err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh, + flags, extack); + if (err == 0) { + tfilter_notify(net, skb, n, tp, block, q, parent, fh, + RTM_NEWTFILTER, false, rtnl_held, extack); + 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; + + 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, extack); + 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, extack); + 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, NULL); + 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, NULL); +} + +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, NULL) <= 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 = rtnl_dereference(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, + struct netlink_ext_ack *extack) +{ + 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; + } + + if (extack && extack->_msg && + nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg)) + goto out_nlmsg_trim; + + 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, + struct netlink_ext_ack *extack) +{ + 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, extack) <= 0) { + kfree_skb(skb); + return -EINVAL; + } + + if (unicast) + err = rtnl_unicast(skb, net, portid); + else + err = rtnetlink_send(skb, net, portid, RTNLGRP_TC, + flags & NLM_F_ECHO); + + 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, NULL) <= 0) { + kfree_skb(skb); + return -EINVAL; + } + + if (unicast) + return rtnl_unicast(skb, net, portid); + + 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"); + module_put(ops->owner); + 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; + struct tcf_chain *chain; + struct tcf_block *block; + unsigned long cl; + int err; + +replay: + q = NULL; + 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, extack); + break; + case RTM_DELCHAIN: + tfilter_notify_chain(net, skb, block, q, parent, n, + chain, RTM_DELTFILTER, extack); + /* 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_flags, n->nlmsg_type, true, extack); + 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 = rtnl_dereference(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, NULL); + 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_ex(struct net *net, struct tcf_proto *tp, struct nlattr **tb, + struct nlattr *rate_tlv, struct tcf_exts *exts, + u32 flags, u32 fl_flags, struct netlink_ext_ack *extack) +{ +#ifdef CONFIG_NET_CLS_ACT + { + int init_res[TCA_ACT_MAX_PRIO] = {}; + struct tc_action *act; + size_t attr_size = 0; + + if (exts->police && tb[exts->police]) { + struct tc_action_ops *a_o; + + a_o = tc_action_load_ops(tb[exts->police], true, + !(flags & TCA_ACT_FLAGS_NO_RTNL), + extack); + if (IS_ERR(a_o)) + return PTR_ERR(a_o); + flags |= TCA_ACT_FLAGS_POLICE | TCA_ACT_FLAGS_BIND; + act = tcf_action_init_1(net, tp, tb[exts->police], + rate_tlv, a_o, init_res, flags, + extack); + module_put(a_o->owner); + if (IS_ERR(act)) + return PTR_ERR(act); + + act->type = exts->type = TCA_OLD_COMPAT; + exts->actions[0] = act; + exts->nr_actions = 1; + tcf_idr_insert_many(exts->actions); + } else if (exts->action && tb[exts->action]) { + int err; + + flags |= TCA_ACT_FLAGS_BIND; + err = tcf_action_init(net, tp, tb[exts->action], + rate_tlv, exts->actions, init_res, + &attr_size, flags, fl_flags, + 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_ex); + +int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb, + struct nlattr *rate_tlv, struct tcf_exts *exts, + u32 flags, struct netlink_ext_ack *extack) +{ + return tcf_exts_validate_ex(net, tp, tb, rate_tlv, exts, + flags, 0, extack); +} +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 min(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 min(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 min(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_offload_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_offload_action); + +static int tc_setup_offload_act(struct tc_action *act, + struct flow_action_entry *entry, + u32 *index_inc, + struct netlink_ext_ack *extack) +{ +#ifdef CONFIG_NET_CLS_ACT + if (act->ops->offload_act_setup) { + return act->ops->offload_act_setup(act, entry, index_inc, true, + extack); + } else { + NL_SET_ERR_MSG(extack, "Action does not support offload"); + return -EOPNOTSUPP; + } +#else + return 0; +#endif +} + +int tc_setup_action(struct flow_action *flow_action, + struct tc_action *actions[], + struct netlink_ext_ack *extack) +{ + int i, j, k, index, err = 0; + struct tc_action *act; + + 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 (!actions) + return 0; + + j = 0; + tcf_act_for_each_action(i, act, actions) { + 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; + + index = 0; + err = tc_setup_offload_act(act, entry, &index, extack); + if (err) + goto err_out_locked; + + for (k = 0; k < index ; k++) { + entry[k].hw_stats = tc_act_hw_stats(act->hw_stats); + entry[k].hw_index = act->tcfa_index; + } + + j += index; + + spin_unlock_bh(&act->tcfa_lock); + } + +err_out: + if (err) + tc_cleanup_offload_action(flow_action); + + return err; +err_out_locked: + spin_unlock_bh(&act->tcfa_lock); + goto err_out; +} + +int tc_setup_offload_action(struct flow_action *flow_action, + const struct tcf_exts *exts, + struct netlink_ext_ack *extack) +{ +#ifdef CONFIG_NET_CLS_ACT + if (!exts) + return 0; + + return tc_setup_action(flow_action, exts->actions, extack); +#else + return 0; +#endif +} +EXPORT_SYMBOL(tc_setup_offload_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; + + 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, NULL, 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); |