/* * net/sched/cls_api.c Packet classifier API. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> * * Changes: * * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support * */ #include <linux/module.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/err.h> #include <linux/skbuff.h> #include <linux/init.h> #include <linux/kmod.h> #include <linux/slab.h> #include <linux/idr.h> #include <linux/rhashtable.h> #include <net/net_namespace.h> #include <net/sock.h> #include <net/netlink.h> #include <net/pkt_sched.h> #include <net/pkt_cls.h> extern const struct nla_policy rtm_tca_policy[TCA_MAX + 1]; /* The list of all installed classifier types */ static LIST_HEAD(tcf_proto_base); /* Protects list of registered TC modules. It is pure SMP lock. */ static DEFINE_RWLOCK(cls_mod_lock); /* 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, struct netlink_ext_ack *extack) { const struct tcf_proto_ops *ops; ops = __tcf_proto_lookup_ops(kind); if (ops) return ops; #ifdef CONFIG_MODULES rtnl_unlock(); request_module("cls_%s", kind); rtnl_lock(); ops = __tcf_proto_lookup_ops(kind); /* We dropped the RTNL semaphore in order to perform * the module load. So, even if we succeeded in loading * the module we have to replay the request. We indicate * this using -EAGAIN. */ if (ops) { module_put(ops->owner); return ERR_PTR(-EAGAIN); } #endif NL_SET_ERR_MSG(extack, "TC classifier not found"); return ERR_PTR(-ENOENT); } /* Register(unregister) new classifier type */ int register_tcf_proto_ops(struct tcf_proto_ops *ops) { struct tcf_proto_ops *t; int rc = -EEXIST; write_lock(&cls_mod_lock); list_for_each_entry(t, &tcf_proto_base, head) if (!strcmp(ops->kind, t->kind)) goto out; list_add_tail(&ops->head, &tcf_proto_base); rc = 0; out: write_unlock(&cls_mod_lock); return rc; } EXPORT_SYMBOL(register_tcf_proto_ops); static struct workqueue_struct *tc_filter_wq; int unregister_tcf_proto_ops(struct tcf_proto_ops *ops) { struct tcf_proto_ops *t; int rc = -ENOENT; /* Wait for outstanding call_rcu()s, if any, from a * tcf_proto_ops's destroy() handler. */ rcu_barrier(); flush_workqueue(tc_filter_wq); write_lock(&cls_mod_lock); list_for_each_entry(t, &tcf_proto_base, head) { if (t == ops) { list_del(&t->head); rc = 0; break; } } write_unlock(&cls_mod_lock); return rc; } EXPORT_SYMBOL(unregister_tcf_proto_ops); bool tcf_queue_work(struct rcu_work *rwork, work_func_t func) { INIT_RCU_WORK(rwork, func); return queue_rcu_work(tc_filter_wq, rwork); } EXPORT_SYMBOL(tcf_queue_work); /* Select new prio value from the range, managed by kernel. */ static inline u32 tcf_auto_prio(struct tcf_proto *tp) { u32 first = TC_H_MAKE(0xC0000000U, 0U); if (tp) first = tp->prio - 1; return TC_H_MAJ(first); } static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol, u32 prio, struct tcf_chain *chain, 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, 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; 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_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack) { tp->ops->destroy(tp, extack); module_put(tp->ops->owner); kfree_rcu(tp, rcu); } 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; chain = kzalloc(sizeof(*chain), GFP_KERNEL); if (!chain) return NULL; list_add_tail(&chain->list, &block->chain_list); 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; list_for_each_entry(item, &block->chain0.filter_chain_list, list) tcf_chain_head_change_item(item, tp_head); } static void tcf_chain_destroy(struct tcf_chain *chain) { struct tcf_block *block = chain->block; list_del(&chain->list); if (!chain->index) block->chain0.chain = NULL; kfree(chain); if (list_empty(&block->chain_list) && !refcount_read(&block->refcnt)) kfree_rcu(block, rcu); } static void tcf_chain_hold(struct tcf_chain *chain) { ++chain->refcnt; } static bool tcf_chain_held_by_acts_only(struct tcf_chain *chain) { /* 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; list_for_each_entry(chain, &block->chain_list, list) { if (chain->index == chain_index) return chain; } return NULL; } static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb, u32 seq, u16 flags, int event, bool unicast); static struct tcf_chain *__tcf_chain_get(struct tcf_block *block, u32 chain_index, bool create, bool by_act) { struct tcf_chain *chain = tcf_chain_lookup(block, chain_index); if (chain) { tcf_chain_hold(chain); } else { if (!create) return NULL; chain = tcf_chain_create(block, chain_index); if (!chain) return NULL; } if (by_act) ++chain->action_refcnt; /* 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 (chain->refcnt - chain->action_refcnt == 1 && !by_act) tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL, RTM_NEWCHAIN, false); 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(struct tcf_chain *chain); static void __tcf_chain_put(struct tcf_chain *chain, bool by_act) { if (by_act) chain->action_refcnt--; chain->refcnt--; /* The last dropped non-action reference will trigger notification. */ if (chain->refcnt - chain->action_refcnt == 0 && !by_act) tc_chain_notify(chain, NULL, 0, 0, RTM_DELCHAIN, false); if (chain->refcnt == 0) { tc_chain_tmplt_del(chain); tcf_chain_destroy(chain); } } static void tcf_chain_put(struct tcf_chain *chain) { __tcf_chain_put(chain, false); } void tcf_chain_put_by_act(struct tcf_chain *chain) { __tcf_chain_put(chain, true); } EXPORT_SYMBOL(tcf_chain_put_by_act); static void tcf_chain_put_explicitly_created(struct tcf_chain *chain) { if (chain->explicitly_created) tcf_chain_put(chain); } static void tcf_chain_flush(struct tcf_chain *chain) { struct tcf_proto *tp = rtnl_dereference(chain->filter_chain); tcf_chain0_head_change(chain, NULL); while (tp) { RCU_INIT_POINTER(chain->filter_chain, tp->next); tcf_proto_destroy(tp, NULL); tp = rtnl_dereference(chain->filter_chain); tcf_chain_put(chain); } } static struct tcf_block *tc_dev_ingress_block(struct net_device *dev) { const struct Qdisc_class_ops *cops; struct Qdisc *qdisc; if (!dev_ingress_queue(dev)) return NULL; qdisc = dev_ingress_queue(dev)->qdisc_sleeping; if (!qdisc) return NULL; cops = qdisc->ops->cl_ops; if (!cops) return NULL; if (!cops->tcf_block) return NULL; return cops->tcf_block(qdisc, TC_H_MIN_INGRESS, NULL); } static struct rhashtable indr_setup_block_ht; struct tc_indr_block_dev { struct rhash_head ht_node; struct net_device *dev; unsigned int refcnt; struct list_head cb_list; struct tcf_block *block; }; struct tc_indr_block_cb { struct list_head list; void *cb_priv; tc_indr_block_bind_cb_t *cb; void *cb_ident; }; static const struct rhashtable_params tc_indr_setup_block_ht_params = { .key_offset = offsetof(struct tc_indr_block_dev, dev), .head_offset = offsetof(struct tc_indr_block_dev, ht_node), .key_len = sizeof(struct net_device *), }; static struct tc_indr_block_dev * tc_indr_block_dev_lookup(struct net_device *dev) { return rhashtable_lookup_fast(&indr_setup_block_ht, &dev, tc_indr_setup_block_ht_params); } static struct tc_indr_block_dev *tc_indr_block_dev_get(struct net_device *dev) { struct tc_indr_block_dev *indr_dev; indr_dev = tc_indr_block_dev_lookup(dev); if (indr_dev) goto inc_ref; indr_dev = kzalloc(sizeof(*indr_dev), GFP_KERNEL); if (!indr_dev) return NULL; INIT_LIST_HEAD(&indr_dev->cb_list); indr_dev->dev = dev; indr_dev->block = tc_dev_ingress_block(dev); if (rhashtable_insert_fast(&indr_setup_block_ht, &indr_dev->ht_node, tc_indr_setup_block_ht_params)) { kfree(indr_dev); return NULL; } inc_ref: indr_dev->refcnt++; return indr_dev; } static void tc_indr_block_dev_put(struct tc_indr_block_dev *indr_dev) { if (--indr_dev->refcnt) return; rhashtable_remove_fast(&indr_setup_block_ht, &indr_dev->ht_node, tc_indr_setup_block_ht_params); kfree(indr_dev); } static struct tc_indr_block_cb * tc_indr_block_cb_lookup(struct tc_indr_block_dev *indr_dev, tc_indr_block_bind_cb_t *cb, void *cb_ident) { struct tc_indr_block_cb *indr_block_cb; list_for_each_entry(indr_block_cb, &indr_dev->cb_list, list) if (indr_block_cb->cb == cb && indr_block_cb->cb_ident == cb_ident) return indr_block_cb; return NULL; } static struct tc_indr_block_cb * tc_indr_block_cb_add(struct tc_indr_block_dev *indr_dev, void *cb_priv, tc_indr_block_bind_cb_t *cb, void *cb_ident) { struct tc_indr_block_cb *indr_block_cb; indr_block_cb = tc_indr_block_cb_lookup(indr_dev, cb, cb_ident); if (indr_block_cb) return ERR_PTR(-EEXIST); indr_block_cb = kzalloc(sizeof(*indr_block_cb), GFP_KERNEL); if (!indr_block_cb) return ERR_PTR(-ENOMEM); indr_block_cb->cb_priv = cb_priv; indr_block_cb->cb = cb; indr_block_cb->cb_ident = cb_ident; list_add(&indr_block_cb->list, &indr_dev->cb_list); return indr_block_cb; } static void tc_indr_block_cb_del(struct tc_indr_block_cb *indr_block_cb) { list_del(&indr_block_cb->list); kfree(indr_block_cb); } static void tc_indr_block_ing_cmd(struct tc_indr_block_dev *indr_dev, struct tc_indr_block_cb *indr_block_cb, enum tc_block_command command) { struct tc_block_offload bo = { .command = command, .binder_type = TCF_BLOCK_BINDER_TYPE_CLSACT_INGRESS, .block = indr_dev->block, }; if (!indr_dev->block) return; indr_block_cb->cb(indr_dev->dev, indr_block_cb->cb_priv, TC_SETUP_BLOCK, &bo); } int __tc_indr_block_cb_register(struct net_device *dev, void *cb_priv, tc_indr_block_bind_cb_t *cb, void *cb_ident) { struct tc_indr_block_cb *indr_block_cb; struct tc_indr_block_dev *indr_dev; int err; indr_dev = tc_indr_block_dev_get(dev); if (!indr_dev) return -ENOMEM; indr_block_cb = tc_indr_block_cb_add(indr_dev, cb_priv, cb, cb_ident); err = PTR_ERR_OR_ZERO(indr_block_cb); if (err) goto err_dev_put; tc_indr_block_ing_cmd(indr_dev, indr_block_cb, TC_BLOCK_BIND); return 0; err_dev_put: tc_indr_block_dev_put(indr_dev); return err; } EXPORT_SYMBOL_GPL(__tc_indr_block_cb_register); int tc_indr_block_cb_register(struct net_device *dev, void *cb_priv, tc_indr_block_bind_cb_t *cb, void *cb_ident) { int err; rtnl_lock(); err = __tc_indr_block_cb_register(dev, cb_priv, cb, cb_ident); rtnl_unlock(); return err; } EXPORT_SYMBOL_GPL(tc_indr_block_cb_register); void __tc_indr_block_cb_unregister(struct net_device *dev, tc_indr_block_bind_cb_t *cb, void *cb_ident) { struct tc_indr_block_cb *indr_block_cb; struct tc_indr_block_dev *indr_dev; indr_dev = tc_indr_block_dev_lookup(dev); if (!indr_dev) return; indr_block_cb = tc_indr_block_cb_lookup(indr_dev, cb, cb_ident); if (!indr_block_cb) return; /* Send unbind message if required to free any block cbs. */ tc_indr_block_ing_cmd(indr_dev, indr_block_cb, TC_BLOCK_UNBIND); tc_indr_block_cb_del(indr_block_cb); tc_indr_block_dev_put(indr_dev); } EXPORT_SYMBOL_GPL(__tc_indr_block_cb_unregister); void tc_indr_block_cb_unregister(struct net_device *dev, tc_indr_block_bind_cb_t *cb, void *cb_ident) { rtnl_lock(); __tc_indr_block_cb_unregister(dev, cb, cb_ident); rtnl_unlock(); } EXPORT_SYMBOL_GPL(tc_indr_block_cb_unregister); static void tc_indr_block_call(struct tcf_block *block, struct net_device *dev, struct tcf_block_ext_info *ei, enum tc_block_command command, struct netlink_ext_ack *extack) { struct tc_indr_block_cb *indr_block_cb; struct tc_indr_block_dev *indr_dev; struct tc_block_offload bo = { .command = command, .binder_type = ei->binder_type, .block = block, .extack = extack, }; indr_dev = tc_indr_block_dev_lookup(dev); if (!indr_dev) return; indr_dev->block = command == TC_BLOCK_BIND ? block : NULL; list_for_each_entry(indr_block_cb, &indr_dev->cb_list, list) indr_block_cb->cb(dev, indr_block_cb->cb_priv, TC_SETUP_BLOCK, &bo); } static bool tcf_block_offload_in_use(struct tcf_block *block) { return block->offloadcnt; } static int tcf_block_offload_cmd(struct tcf_block *block, struct net_device *dev, struct tcf_block_ext_info *ei, enum tc_block_command command, struct netlink_ext_ack *extack) { struct tc_block_offload bo = {}; bo.command = command; bo.binder_type = ei->binder_type; bo.block = block; bo.extack = extack; return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo); } 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; if (!dev->netdev_ops->ndo_setup_tc) goto no_offload_dev_inc; /* If tc offload feature is disabled and the block we try to bind * to already has some offloaded filters, forbid to bind. */ if (!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"); return -EOPNOTSUPP; } err = tcf_block_offload_cmd(block, dev, ei, TC_BLOCK_BIND, extack); if (err == -EOPNOTSUPP) goto no_offload_dev_inc; if (err) return err; tc_indr_block_call(block, dev, ei, TC_BLOCK_BIND, extack); return 0; no_offload_dev_inc: if (tcf_block_offload_in_use(block)) return -EOPNOTSUPP; block->nooffloaddevcnt++; tc_indr_block_call(block, dev, ei, TC_BLOCK_BIND, extack); return 0; } 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; tc_indr_block_call(block, dev, ei, TC_BLOCK_UNBIND, NULL); if (!dev->netdev_ops->ndo_setup_tc) goto no_offload_dev_dec; err = tcf_block_offload_cmd(block, dev, ei, TC_BLOCK_UNBIND, NULL); if (err == -EOPNOTSUPP) goto no_offload_dev_dec; return; no_offload_dev_dec: WARN_ON(block->nooffloaddevcnt-- == 0); } 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_chain *chain0 = block->chain0.chain; struct tcf_filter_chain_list_item *item; 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; if (chain0 && chain0->filter_chain) tcf_chain_head_change_item(item, chain0->filter_chain); list_add(&item->list, &block->chain0.filter_chain_list); return 0; } static void tcf_chain0_head_change_cb_del(struct tcf_block *block, struct tcf_block_ext_info *ei) { struct tcf_chain *chain0 = block->chain0.chain; struct tcf_filter_chain_list_item *item; 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 (chain0) tcf_chain_head_change_item(item, NULL); list_del(&item->list); kfree(item); return; } } 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); } INIT_LIST_HEAD(&block->chain_list); INIT_LIST_HEAD(&block->cb_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 void tcf_block_flush_all_chains(struct tcf_block *block) { struct tcf_chain *chain; /* Hold a refcnt for all chains, so that they don't disappear * while we are iterating. */ list_for_each_entry(chain, &block->chain_list, list) tcf_chain_hold(chain); list_for_each_entry(chain, &block->chain_list, list) tcf_chain_flush(chain); } static void tcf_block_put_all_chains(struct tcf_block *block) { struct tcf_chain *chain, *tmp; /* At this point, all the chains should have refcnt >= 1. */ list_for_each_entry_safe(chain, tmp, &block->chain_list, list) { tcf_chain_put_explicitly_created(chain); tcf_chain_put(chain); } } static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q, struct tcf_block_ext_info *ei) { if (refcount_dec_and_test(&block->refcnt)) { /* 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); if (tcf_block_shared(block)) tcf_block_remove(block, block->net); if (!free_block) tcf_block_flush_all_chains(block); if (q) tcf_block_offload_unbind(block, q, ei); if (free_block) kfree_rcu(block, rcu); else tcf_block_put_all_chains(block); } else if (q) { tcf_block_offload_unbind(block, q, ei); } } static void tcf_block_refcnt_put(struct tcf_block *block) { __tcf_block_put(block, NULL, NULL); } /* 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; 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; struct net_device *dev; rcu_read_lock(); /* Find link */ dev = dev_get_by_index_rcu(net, ifindex); if (!dev) { rcu_read_unlock(); return ERR_PTR(-ENODEV); } /* Find qdisc */ if (!*parent) { *q = dev->qdisc; *parent = (*q)->handle; } else { *q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent)); if (!*q) { NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists"); err = -EINVAL; goto errout_rcu; } } *q = qdisc_refcount_inc_nz(*q); if (!*q) { NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists"); err = -EINVAL; goto errout_rcu; } /* Is it classful? */ cops = (*q)->ops->cl_ops; if (!cops) { NL_SET_ERR_MSG(extack, "Qdisc not classful"); err = -EINVAL; goto errout_rcu; } if (!cops->tcf_block) { NL_SET_ERR_MSG(extack, "Class doesn't support blocks"); err = -EOPNOTSUPP; goto 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(); /* Do we search for filter, attached to class? */ if (TC_H_MIN(*parent)) { *cl = cops->find(*q, *parent); if (*cl == 0) { NL_SET_ERR_MSG(extack, "Specified class doesn't exist"); err = -ENOENT; goto errout_qdisc; } } /* And the last stroke */ block = cops->tcf_block(*q, *cl, extack); if (!block) { err = -EINVAL; goto errout_qdisc; } if (tcf_block_shared(block)) { NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters"); err = -EOPNOTSUPP; goto errout_qdisc; } /* 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; errout_rcu: rcu_read_unlock(); errout_qdisc: if (*q) { qdisc_put(*q); *q = NULL; } return ERR_PTR(err); } static void tcf_block_release(struct Qdisc *q, struct tcf_block *block) { if (!IS_ERR_OR_NULL(block)) tcf_block_refcnt_put(block); if (q) qdisc_put(q); } struct tcf_block_owner_item { struct list_head list; struct Qdisc *q; enum tcf_block_binder_type binder_type; }; static void tcf_block_owner_netif_keep_dst(struct tcf_block *block, struct Qdisc *q, enum tcf_block_binder_type binder_type) { if (block->keep_dst && binder_type != TCF_BLOCK_BINDER_TYPE_CLSACT_INGRESS && binder_type != TCF_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 tcf_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 tcf_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); 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); } 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); struct tcf_block_cb { struct list_head list; tc_setup_cb_t *cb; void *cb_ident; void *cb_priv; unsigned int refcnt; }; void *tcf_block_cb_priv(struct tcf_block_cb *block_cb) { return block_cb->cb_priv; } EXPORT_SYMBOL(tcf_block_cb_priv); struct tcf_block_cb *tcf_block_cb_lookup(struct tcf_block *block, tc_setup_cb_t *cb, void *cb_ident) { struct tcf_block_cb *block_cb; list_for_each_entry(block_cb, &block->cb_list, list) if (block_cb->cb == cb && block_cb->cb_ident == cb_ident) return block_cb; return NULL; } EXPORT_SYMBOL(tcf_block_cb_lookup); void tcf_block_cb_incref(struct tcf_block_cb *block_cb) { block_cb->refcnt++; } EXPORT_SYMBOL(tcf_block_cb_incref); unsigned int tcf_block_cb_decref(struct tcf_block_cb *block_cb) { return --block_cb->refcnt; } EXPORT_SYMBOL(tcf_block_cb_decref); static int tcf_block_playback_offloads(struct tcf_block *block, tc_setup_cb_t *cb, void *cb_priv, bool add, bool offload_in_use, struct netlink_ext_ack *extack) { struct tcf_chain *chain; struct tcf_proto *tp; int err; list_for_each_entry(chain, &block->chain_list, list) { for (tp = rtnl_dereference(chain->filter_chain); tp; tp = rtnl_dereference(tp->next)) { 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_block_playback_offloads(block, cb, cb_priv, false, offload_in_use, extack); return err; } struct tcf_block_cb *__tcf_block_cb_register(struct tcf_block *block, tc_setup_cb_t *cb, void *cb_ident, void *cb_priv, struct netlink_ext_ack *extack) { struct tcf_block_cb *block_cb; int err; /* Replay any already present rules */ err = tcf_block_playback_offloads(block, cb, cb_priv, true, tcf_block_offload_in_use(block), extack); if (err) return ERR_PTR(err); block_cb = kzalloc(sizeof(*block_cb), GFP_KERNEL); if (!block_cb) return ERR_PTR(-ENOMEM); block_cb->cb = cb; block_cb->cb_ident = cb_ident; block_cb->cb_priv = cb_priv; list_add(&block_cb->list, &block->cb_list); return block_cb; } EXPORT_SYMBOL(__tcf_block_cb_register); int tcf_block_cb_register(struct tcf_block *block, tc_setup_cb_t *cb, void *cb_ident, void *cb_priv, struct netlink_ext_ack *extack) { struct tcf_block_cb *block_cb; block_cb = __tcf_block_cb_register(block, cb, cb_ident, cb_priv, extack); return PTR_ERR_OR_ZERO(block_cb); } EXPORT_SYMBOL(tcf_block_cb_register); void __tcf_block_cb_unregister(struct tcf_block *block, struct tcf_block_cb *block_cb) { 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); kfree(block_cb); } EXPORT_SYMBOL(__tcf_block_cb_unregister); void tcf_block_cb_unregister(struct tcf_block *block, tc_setup_cb_t *cb, void *cb_ident) { struct tcf_block_cb *block_cb; block_cb = tcf_block_cb_lookup(block, cb, cb_ident); if (!block_cb) return; __tcf_block_cb_unregister(block, block_cb); } EXPORT_SYMBOL(tcf_block_cb_unregister); static int tcf_block_cb_call(struct tcf_block *block, enum tc_setup_type type, void *type_data, bool err_stop) { struct tcf_block_cb *block_cb; int ok_count = 0; int err; /* Make sure all netdevs sharing this block are offload-capable. */ if (block->nooffloaddevcnt && err_stop) return -EOPNOTSUPP; list_for_each_entry(block_cb, &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; } /* Main classifier routine: scans classifier chain attached * to this qdisc, (optionally) tests for protocol and asks * specific classifiers. */ int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp, struct tcf_result *res, bool compat_mode) { __be16 protocol = tc_skb_protocol(skb); #ifdef CONFIG_NET_CLS_ACT const int max_reclassify_loop = 4; const struct tcf_proto *orig_tp = tp; const struct tcf_proto *first_tp; int limit = 0; reclassify: #endif for (; tp; tp = rcu_dereference_bh(tp->next)) { 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; goto reset; } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) { first_tp = res->goto_tp; 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; protocol = tc_skb_protocol(skb); goto reclassify; #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_info *chain_info) { return rtnl_dereference(*chain_info->pprev); } static void tcf_chain_tp_insert(struct tcf_chain *chain, struct tcf_chain_info *chain_info, struct tcf_proto *tp) { if (*chain_info->pprev == chain->filter_chain) tcf_chain0_head_change(chain, tp); RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info)); rcu_assign_pointer(*chain_info->pprev, tp); tcf_chain_hold(chain); } static void tcf_chain_tp_remove(struct tcf_chain *chain, struct tcf_chain_info *chain_info, struct tcf_proto *tp) { struct tcf_proto *next = rtnl_dereference(chain_info->next); if (tp == chain->filter_chain) tcf_chain0_head_change(chain, next); RCU_INIT_POINTER(*chain_info->pprev, next); tcf_chain_put(chain); } 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 = rtnl_dereference(*pprev)); 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; chain_info->next = tp ? tp->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) { 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 (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0) goto nla_put_failure; } nlh->nlmsg_len = skb_tail_pointer(skb) - b; return skb->len; out_nlmsg_trim: nla_put_failure: nlmsg_trim(skb, b); return -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) { struct sk_buff *skb; u32 portid = oskb ? NETLINK_CB(oskb).portid : 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) <= 0) { kfree_skb(skb); return -EINVAL; } if (unicast) return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT); return rtnetlink_send(skb, net, portid, RTNLGRP_TC, n->nlmsg_flags & NLM_F_ECHO); } 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, 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) <= 0) { NL_SET_ERR_MSG(extack, "Failed to build del event notification"); kfree_skb(skb); return -EINVAL; } err = tp->ops->delete(tp, fh, last, extack); if (err) { kfree_skb(skb); return err; } if (unicast) return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT); 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 tcf_proto *tp; for (tp = rtnl_dereference(chain->filter_chain); tp; tp = rtnl_dereference(tp->next)) tfilter_notify(net, oskb, n, tp, block, q, parent, NULL, event, false); } 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]; struct tcmsg *t; u32 protocol; u32 prio; bool prio_allocate; u32 parent; u32 chain_index; struct Qdisc *q = NULL; struct tcf_chain_info chain_info; struct tcf_chain *chain = NULL; struct tcf_block *block; struct tcf_proto *tp; unsigned long cl; void *fh; int err; int tp_created; if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) return -EPERM; replay: tp_created = 0; err = nlmsg_parse(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; cl = 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. */ block = tcf_block_find(net, &q, &parent, &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, true); if (!chain) { NL_SET_ERR_MSG(extack, "Cannot create specified filter chain"); err = -ENOMEM; goto errout; } 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; } if (tp == NULL) { /* 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; } 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; } if (prio_allocate) prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info)); tp = tcf_proto_create(nla_data(tca[TCA_KIND]), protocol, prio, chain, extack); if (IS_ERR(tp)) { err = PTR_ERR(tp); goto errout; } tp_created = 1; } 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) { 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) { NL_SET_ERR_MSG(extack, "Filter already exists"); err = -EEXIST; goto errout; } if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) { NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind"); err = -EINVAL; goto errout; } err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh, n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE, extack); if (err == 0) { if (tp_created) tcf_chain_tp_insert(chain, &chain_info, tp); tfilter_notify(net, skb, n, tp, block, q, parent, fh, RTM_NEWTFILTER, false); } else { if (tp_created) tcf_proto_destroy(tp, NULL); } errout: if (chain) tcf_chain_put(chain); tcf_block_release(q, block); if (err == -EAGAIN) /* Replay the request. */ goto replay; return err; } 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]; 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; struct tcf_proto *tp = NULL; unsigned long cl = 0; void *fh = NULL; int err; if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) return -EPERM; err = nlmsg_parse(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. */ block = tcf_block_find(net, &q, &parent, &cl, t->tcm_ifindex, t->tcm_block_index, extack); if (IS_ERR(block)) { err = PTR_ERR(block); goto errout; } chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0; if (chain_index > TC_ACT_EXT_VAL_MASK) { NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit"); err = -EINVAL; goto errout; } chain = tcf_chain_get(block, chain_index, false); if (!chain) { /* User requested flush on non-existent chain. Nothing to do, * so just return success. */ if (prio == 0) { err = 0; goto errout; } NL_SET_ERR_MSG(extack, "Cannot find specified filter chain"); err = -ENOENT; goto errout; } if (prio == 0) { tfilter_notify_chain(net, skb, block, q, parent, n, chain, RTM_DELTFILTER); tcf_chain_flush(chain); err = 0; goto errout; } 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; } 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) { if (t->tcm_handle == 0) { tcf_chain_tp_remove(chain, &chain_info, tp); tfilter_notify(net, skb, n, tp, block, q, parent, fh, RTM_DELTFILTER, false); tcf_proto_destroy(tp, extack); err = 0; } else { 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, extack); if (err) goto errout; if (last) { tcf_chain_tp_remove(chain, &chain_info, tp); tcf_proto_destroy(tp, extack); } } errout: if (chain) tcf_chain_put(chain); tcf_block_release(q, block); return err; } 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]; 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; struct tcf_proto *tp = NULL; unsigned long cl = 0; void *fh = NULL; int err; err = nlmsg_parse(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. */ block = tcf_block_find(net, &q, &parent, &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; } 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; } 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); if (err < 0) NL_SET_ERR_MSG(extack, "Failed to send filter notify message"); } errout: if (chain) tcf_chain_put(chain); tcf_block_release(q, block); 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; }; 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); } 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) { struct net *net = sock_net(skb->sk); struct tcf_block *block = chain->block; struct tcmsg *tcm = nlmsg_data(cb->nlh); struct tcf_dump_args arg; struct tcf_proto *tp; for (tp = rtnl_dereference(chain->filter_chain); tp; tp = rtnl_dereference(tp->next), (*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) <= 0) return false; 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]; tp->ops->walk(tp, &arg.w); cb->args[2] = arg.w.cookie; cb->args[1] = arg.w.count + 1; if (arg.w.stop) return false; } return true; } /* called with RTNL */ static int tc_dump_tfilter(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 tcf_chain *chain; struct tcmsg *tcm = nlmsg_data(cb->nlh); long index_start; long index; u32 parent; int err; if (nlmsg_len(cb->nlh) < sizeof(*tcm)) return skb->len; err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, 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; /* If we work with block index, q is NULL and parent value * will never be used in the following code. The check * in tcf_fill_node prevents it. However, compiler does not * see that far, so set parent to zero to silence the warning * about parent being uninitialized. */ parent = 0; } else { const struct Qdisc_class_ops *cops; struct net_device *dev; unsigned long cl = 0; dev = __dev_get_by_index(net, tcm->tcm_ifindex); if (!dev) return skb->len; parent = tcm->tcm_parent; if (!parent) { q = dev->qdisc; parent = q->handle; } 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; list_for_each_entry(chain, &block->chain_list, list) { 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)) { err = -EMSGSIZE; break; } } if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) tcf_block_refcnt_put(block); 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(struct tcf_chain *chain, struct net *net, struct sk_buff *skb, struct tcf_block *block, u32 portid, u32 seq, u16 flags, int event) { unsigned char *b = skb_tail_pointer(skb); const struct tcf_proto_ops *ops; struct nlmsghdr *nlh; struct tcmsg *tcm; void *priv; ops = chain->tmplt_ops; priv = chain->tmplt_priv; nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); if (!nlh) goto out_nlmsg_trim; tcm = nlmsg_data(nlh); tcm->tcm_family = AF_UNSPEC; tcm->tcm__pad1 = 0; tcm->tcm__pad2 = 0; tcm->tcm_handle = 0; if (block->q) { tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex; tcm->tcm_parent = block->q->handle; } else { tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK; tcm->tcm_block_index = block->index; } if (nla_put_u32(skb, TCA_CHAIN, chain->index)) goto nla_put_failure; if (ops) { if (nla_put_string(skb, TCA_KIND, ops->kind)) goto nla_put_failure; if (ops->tmplt_dump(skb, net, priv) < 0) goto nla_put_failure; } nlh->nlmsg_len = skb_tail_pointer(skb) - b; return skb->len; out_nlmsg_trim: nla_put_failure: nlmsg_trim(skb, b); return -EMSGSIZE; } static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb, u32 seq, u16 flags, int event, bool unicast) { u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; struct tcf_block *block = chain->block; struct net *net = block->net; struct sk_buff *skb; skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); if (!skb) return -ENOBUFS; if (tc_chain_fill_node(chain, net, skb, block, portid, seq, flags, event) <= 0) { kfree_skb(skb); return -EINVAL; } if (unicast) return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT); return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO); } static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net, struct nlattr **tca, struct netlink_ext_ack *extack) { const struct tcf_proto_ops *ops; void *tmplt_priv; /* If kind is not set, user did not specify template. */ if (!tca[TCA_KIND]) return 0; ops = tcf_proto_lookup_ops(nla_data(tca[TCA_KIND]), extack); if (IS_ERR(ops)) return PTR_ERR(ops); if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) { NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier"); return -EOPNOTSUPP; } tmplt_priv = ops->tmplt_create(net, chain, tca, extack); if (IS_ERR(tmplt_priv)) { module_put(ops->owner); return PTR_ERR(tmplt_priv); } chain->tmplt_ops = ops; chain->tmplt_priv = tmplt_priv; return 0; } static void tc_chain_tmplt_del(struct tcf_chain *chain) { const struct tcf_proto_ops *ops = chain->tmplt_ops; /* If template ops are set, no work to do for us. */ if (!ops) return; ops->tmplt_destroy(chain->tmplt_priv); module_put(ops->owner); } /* Add/delete/get a chain */ static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n, struct netlink_ext_ack *extack) { struct net *net = sock_net(skb->sk); struct nlattr *tca[TCA_MAX + 1]; struct tcmsg *t; u32 parent; u32 chain_index; struct Qdisc *q = NULL; struct tcf_chain *chain = NULL; struct tcf_block *block; unsigned long cl; int err; if (n->nlmsg_type != RTM_GETCHAIN && !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) return -EPERM; replay: err = nlmsg_parse(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; } 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; } } 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; } chain = tcf_chain_create(block, chain_index); if (!chain) { NL_SET_ERR_MSG(extack, "Failed to create filter chain"); err = -ENOMEM; goto errout_block; } } } 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; } tcf_chain_hold(chain); } switch (n->nlmsg_type) { case RTM_NEWCHAIN: err = tc_chain_tmplt_add(chain, net, tca, extack); if (err) goto errout; /* 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; tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL, RTM_NEWCHAIN, false); break; case RTM_DELCHAIN: tfilter_notify_chain(net, skb, block, q, parent, n, chain, RTM_DELTFILTER); /* Flush the chain first as the user requested chain removal. */ tcf_chain_flush(chain); /* In case the chain was successfully deleted, put a reference * to the chain previously taken during addition. */ tcf_chain_put_explicitly_created(chain); chain->explicitly_created = false; break; case RTM_GETCHAIN: err = tc_chain_notify(chain, skb, n->nlmsg_seq, n->nlmsg_seq, n->nlmsg_type, true); if (err < 0) NL_SET_ERR_MSG(extack, "Failed to send chain notify message"); break; default: err = -EOPNOTSUPP; NL_SET_ERR_MSG(extack, "Unsupported message type"); goto errout; } errout: tcf_chain_put(chain); errout_block: tcf_block_release(q, block); if (err == -EAGAIN) /* Replay the request. */ goto replay; return err; } /* 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 tcf_chain *chain; struct tcmsg *tcm = nlmsg_data(cb->nlh); long index_start; long index; u32 parent; int err; if (nlmsg_len(cb->nlh) < sizeof(*tcm)) return skb->len; err = nlmsg_parse(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; /* If we work with block index, q is NULL and parent value * will never be used in the following code. The check * in tcf_fill_node prevents it. However, compiler does not * see that far, so set parent to zero to silence the warning * about parent being uninitialized. */ parent = 0; } else { const struct Qdisc_class_ops *cops; struct net_device *dev; unsigned long cl = 0; dev = __dev_get_by_index(net, tcm->tcm_ifindex); if (!dev) return skb->len; parent = tcm->tcm_parent; if (!parent) { q = dev->qdisc; parent = q->handle; } 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; 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, net, skb, block, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWCHAIN); if (err <= 0) break; index++; } if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) tcf_block_refcnt_put(block); 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 tcf_action_destroy(exts->actions, TCA_ACT_UNBIND); kfree(exts->actions); exts->nr_actions = 0; #endif } EXPORT_SYMBOL(tcf_exts_destroy); int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb, struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr, struct netlink_ext_ack *extack) { #ifdef CONFIG_NET_CLS_ACT { struct tc_action *act; size_t attr_size = 0; if (exts->police && tb[exts->police]) { act = tcf_action_init_1(net, tp, tb[exts->police], rate_tlv, "police", ovr, TCA_ACT_BIND, true, extack); if (IS_ERR(act)) return PTR_ERR(act); act->type = exts->type = TCA_OLD_COMPAT; exts->actions[0] = act; exts->nr_actions = 1; } else if (exts->action && tb[exts->action]) { int err; err = tcf_action_init(net, tp, tb[exts->action], rate_tlv, NULL, ovr, TCA_ACT_BIND, exts->actions, &attr_size, true, extack); if (err < 0) return err; exts->nr_actions = err; } exts->net = net; } #else if ((exts->action && tb[exts->action]) || (exts->police && tb[exts->police])) { NL_SET_ERR_MSG(extack, "Classifier actions are not supported per compile options (CONFIG_NET_CLS_ACT)"); return -EOPNOTSUPP; } #endif return 0; } EXPORT_SYMBOL(tcf_exts_validate); void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src) { #ifdef CONFIG_NET_CLS_ACT struct tcf_exts old = *dst; *dst = *src; tcf_exts_destroy(&old); #endif } EXPORT_SYMBOL(tcf_exts_change); #ifdef CONFIG_NET_CLS_ACT static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts) { if (exts->nr_actions == 0) return NULL; else return exts->actions[0]; } #endif int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts) { #ifdef CONFIG_NET_CLS_ACT struct nlattr *nest; if (exts->action && tcf_exts_has_actions(exts)) { /* * again for backward compatible mode - we want * to work with both old and new modes of entering * tc data even if iproute2 was newer - jhs */ if (exts->type != TCA_OLD_COMPAT) { nest = nla_nest_start(skb, exts->action); if (nest == NULL) goto nla_put_failure; if (tcf_action_dump(skb, exts->actions, 0, 0) < 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(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_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 int tc_exts_setup_cb_egdev_call(struct tcf_exts *exts, enum tc_setup_type type, void *type_data, bool err_stop) { int ok_count = 0; #ifdef CONFIG_NET_CLS_ACT const struct tc_action *a; struct net_device *dev; int i, ret; if (!tcf_exts_has_actions(exts)) return 0; for (i = 0; i < exts->nr_actions; i++) { a = exts->actions[i]; if (!a->ops->get_dev) continue; dev = a->ops->get_dev(a); if (!dev) continue; ret = tc_setup_cb_egdev_call(dev, type, type_data, err_stop); a->ops->put_dev(dev); if (ret < 0) return ret; ok_count += ret; } #endif return ok_count; } int tc_setup_cb_call(struct tcf_block *block, struct tcf_exts *exts, enum tc_setup_type type, void *type_data, bool err_stop) { int ok_count; int ret; ret = tcf_block_cb_call(block, type, type_data, err_stop); if (ret < 0) return ret; ok_count = ret; if (!exts || ok_count) return ok_count; ret = tc_exts_setup_cb_egdev_call(exts, type, type_data, err_stop); if (ret < 0) return ret; ok_count += ret; return ok_count; } EXPORT_SYMBOL(tc_setup_cb_call); 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; err = rhashtable_init(&indr_setup_block_ht, &tc_indr_setup_block_ht_params); if (err) goto err_rhash_setup_block_ht; rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL, 0); rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL, 0); rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter, tc_dump_tfilter, 0); 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_rhash_setup_block_ht: unregister_pernet_subsys(&tcf_net_ops); err_register_pernet_subsys: destroy_workqueue(tc_filter_wq); return err; } subsys_initcall(tc_filter_init);