diff options
Diffstat (limited to 'net/sched/cls_api.c')
| -rw-r--r-- | net/sched/cls_api.c | 2320 |
1 files changed, 2320 insertions, 0 deletions
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c new file mode 100644 index 000000000..435911dc9 --- /dev/null +++ b/net/sched/cls_api.c @@ -0,0 +1,2320 @@ +/* + * 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 <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) && block->refcnt == 0) + kfree(block); +} + +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 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; + return err; + +no_offload_dev_inc: + if (tcf_block_offload_in_use(block)) + return -EOPNOTSUPP; + block->nooffloaddevcnt++; + 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; + + 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 { + 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); + + return idr_alloc_u32(&tn->idr, block, &block->index, block->index, + GFP_KERNEL); +} + +static void tcf_block_remove(struct tcf_block *block, struct net *net) +{ + struct tcf_net *tn = net_generic(net, tcf_net_id); + + idr_remove(&tn->idr, block->index); +} + +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); + + 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); +} + +/* 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_lookup(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; + } + } + + 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 (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; + bool created = false; + int err; + + if (ei->block_index) { + /* block_index not 0 means the shared block is requested */ + block = tcf_block_lookup(net, ei->block_index); + if (block) + block->refcnt++; + } + + if (!block) { + block = tcf_block_create(net, q, ei->block_index, extack); + if (IS_ERR(block)) + return PTR_ERR(block); + created = true; + 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: + if (created) { + if (tcf_block_shared(block)) + tcf_block_remove(block, net); +err_block_insert: + kfree(block); + } else { + block->refcnt--; + } + 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) +{ + struct tcf_chain *chain, *tmp; + + if (!block) + return; + tcf_chain0_head_change_cb_del(block, ei); + tcf_block_owner_del(block, q, ei->binder_type); + + if (block->refcnt == 1) { + if (tcf_block_shared(block)) + tcf_block_remove(block, block->net); + + /* 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); + } + + tcf_block_offload_unbind(block, q, ei); + + if (block->refcnt == 1) { + /* 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); + } + + block->refcnt--; + if (list_empty(&block->chain_list)) + kfree(block); + } else { + block->refcnt--; + } +} +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) +{ +#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)) { + __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; + 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; + 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); + /* q pointer is NULL for shared blocks */ + if (q) + q->flags &= ~TCQ_F_CAN_BYPASS; + } 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, NULL); + if (err) + return err; + + if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) { + block = tcf_block_lookup(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; + } + } + + 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_flags, 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, + NULL); + if (err) + return err; + + if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) { + block = tcf_block_lookup(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++; + } + + cb->args[0] = index; + +out: + /* If we did no progress, the error (EMSGSIZE) is real */ + if (skb->len == 0 && err) + return err; + return skb->len; +} + +void tcf_exts_destroy(struct tcf_exts *exts) +{ +#ifdef CONFIG_NET_CLS_ACT + if (exts->actions) { + tcf_action_destroy(exts->actions, TCA_ACT_UNBIND); + kfree(exts->actions); + } + exts->nr_actions = 0; +#endif +} +EXPORT_SYMBOL(tcf_exts_destroy); + +int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb, + struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr, + 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); + + 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, 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_register_pernet_subsys: + destroy_workqueue(tc_filter_wq); + return err; +} + +subsys_initcall(tc_filter_init); |