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cls_api.c
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/*
* 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, <[email protected]>
*
* Changes:
*
* Eduardo J. Blanco <[email protected]> :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/err.h>
#include <linux/slab.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
/* The list of all installed classifier types */
static LIST_HEAD(tcf_proto_base);
/* Protects list of registered TC modules. It is pure SMP lock. */
static DEFINE_RWLOCK(cls_mod_lock);
/* 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;
}
/* 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 work_struct *work)
{
return queue_work(tc_filter_wq, work);
}
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, u32 parent, struct Qdisc *q,
struct tcf_chain *chain)
{
struct tcf_proto *tp;
int err;
tp = kzalloc(sizeof(*tp), GFP_KERNEL);
if (!tp)
return ERR_PTR(-ENOBUFS);
err = -ENOENT;
tp->ops = tcf_proto_lookup_ops(kind);
if (!tp->ops) {
#ifdef CONFIG_MODULES
rtnl_unlock();
request_module("cls_%s", kind);
rtnl_lock();
tp->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 (tp->ops) {
module_put(tp->ops->owner);
err = -EAGAIN;
} else {
err = -ENOENT;
}
goto errout;
#endif
}
tp->classify = tp->ops->classify;
tp->protocol = protocol;
tp->prio = prio;
tp->classid = parent;
tp->q = q;
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)
{
tp->ops->destroy(tp);
module_put(tp->ops->owner);
kfree_rcu(tp, rcu);
}
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;
return chain;
}
static void tcf_chain_head_change(struct tcf_chain *chain,
struct tcf_proto *tp_head)
{
if (chain->chain_head_change)
chain->chain_head_change(tp_head,
chain->chain_head_change_priv);
}
static void tcf_chain_flush(struct tcf_chain *chain)
{
struct tcf_proto *tp;
tcf_chain_head_change(chain, NULL);
while ((tp = rtnl_dereference(chain->filter_chain)) != NULL) {
RCU_INIT_POINTER(chain->filter_chain, tp->next);
tcf_chain_put(chain);
tcf_proto_destroy(tp);
}
}
static void tcf_chain_destroy(struct tcf_chain *chain)
{
list_del(&chain->list);
kfree(chain);
}
static void tcf_chain_hold(struct tcf_chain *chain)
{
++chain->refcnt;
}
struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
bool create)
{
struct tcf_chain *chain;
list_for_each_entry(chain, &block->chain_list, list) {
if (chain->index == chain_index) {
tcf_chain_hold(chain);
return chain;
}
}
return create ? tcf_chain_create(block, chain_index) : NULL;
}
EXPORT_SYMBOL(tcf_chain_get);
void tcf_chain_put(struct tcf_chain *chain)
{
if (--chain->refcnt == 0)
tcf_chain_destroy(chain);
}
EXPORT_SYMBOL(tcf_chain_put);
static void tcf_block_offload_cmd(struct tcf_block *block, struct Qdisc *q,
struct tcf_block_ext_info *ei,
enum tc_block_command command)
{
struct net_device *dev = q->dev_queue->dev;
struct tc_block_offload bo = {};
if (!dev->netdev_ops->ndo_setup_tc)
return;
bo.command = command;
bo.binder_type = ei->binder_type;
bo.block = block;
dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
}
static void tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
struct tcf_block_ext_info *ei)
{
tcf_block_offload_cmd(block, q, ei, TC_BLOCK_BIND);
}
static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
struct tcf_block_ext_info *ei)
{
tcf_block_offload_cmd(block, q, ei, TC_BLOCK_UNBIND);
}
int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
struct tcf_block_ext_info *ei)
{
struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL);
struct tcf_chain *chain;
int err;
if (!block)
return -ENOMEM;
INIT_LIST_HEAD(&block->chain_list);
INIT_LIST_HEAD(&block->cb_list);
/* Create chain 0 by default, it has to be always present. */
chain = tcf_chain_create(block, 0);
if (!chain) {
err = -ENOMEM;
goto err_chain_create;
}
WARN_ON(!ei->chain_head_change);
chain->chain_head_change = ei->chain_head_change;
chain->chain_head_change_priv = ei->chain_head_change_priv;
block->net = qdisc_net(q);
block->q = q;
tcf_block_offload_bind(block, q, ei);
*p_block = block;
return 0;
err_chain_create:
kfree(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 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);
}
EXPORT_SYMBOL(tcf_block_get);
static void tcf_block_put_final(struct work_struct *work)
{
struct tcf_block *block = container_of(work, struct tcf_block, work);
struct tcf_chain *chain, *tmp;
rtnl_lock();
/* Only chain 0 should be still here. */
list_for_each_entry_safe(chain, tmp, &block->chain_list, list)
tcf_chain_put(chain);
rtnl_unlock();
kfree(block);
}
/* XXX: Standalone actions are not allowed to jump to any chain, and bound
* actions should be all removed after flushing. However, filters are now
* destroyed in tc filter workqueue with RTNL lock, they can not race here.
*/
void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
struct tcf_block_ext_info *ei)
{
struct tcf_chain *chain, *tmp;
list_for_each_entry_safe(chain, tmp, &block->chain_list, list)
tcf_chain_flush(chain);
tcf_block_offload_unbind(block, q, ei);
INIT_WORK(&block->work, tcf_block_put_final);
/* Wait for existing RCU callbacks to cool down, make sure their works
* have been queued before this. We can not flush pending works here
* because we are holding the RTNL lock.
*/
rcu_barrier();
tcf_queue_work(&block->work);
}
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);
struct tcf_block_cb *__tcf_block_cb_register(struct tcf_block *block,
tc_setup_cb_t *cb, void *cb_ident,
void *cb_priv)
{
struct tcf_block_cb *block_cb;
block_cb = kzalloc(sizeof(*block_cb), GFP_KERNEL);
if (!block_cb)
return NULL;
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 tcf_block_cb *block_cb;
block_cb = __tcf_block_cb_register(block, cb, cb_ident, cb_priv);
return block_cb ? 0 : -ENOMEM;
}
EXPORT_SYMBOL(tcf_block_cb_register);
void __tcf_block_cb_unregister(struct tcf_block_cb *block_cb)
{
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_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;
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("%s: reclassify loop, rule prio %u, protocol %02x\n",
tp->q->ops->id, 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_chain_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_chain_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 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;
tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
tcm->tcm_parent = parent;
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 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, 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 Qdisc *q, u32 parent,
void *fh, bool unicast, bool *last)
{
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, q, parent, fh, portid, n->nlmsg_seq,
n->nlmsg_flags, RTM_DELTFILTER) <= 0) {
kfree_skb(skb);
return -EINVAL;
}
err = tp->ops->delete(tp, fh, last);
if (err) {
kfree_skb(skb);
return err;
}
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 void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
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, q, parent, 0, event, false);
}
/* Add/change/delete/get a filter node */
static int tc_ctl_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 net_device *dev;
struct Qdisc *q;
struct tcf_chain_info chain_info;
struct tcf_chain *chain = NULL;
struct tcf_block *block;
struct tcf_proto *tp;
const struct Qdisc_class_ops *cops;
unsigned long cl;
void *fh;
int err;
int tp_created;
if ((n->nlmsg_type != RTM_GETTFILTER) &&
!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, NULL, 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) {
switch (n->nlmsg_type) {
case RTM_DELTFILTER:
if (protocol || t->tcm_handle || tca[TCA_KIND])
return -ENOENT;
break;
case RTM_NEWTFILTER:
/* 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;
break;
}
/* fall-through */
default:
return -ENOENT;
}
}
/* Find head of filter chain. */
/* Find link */
dev = __dev_get_by_index(net, t->tcm_ifindex);
if (dev == NULL)
return -ENODEV;
/* Find qdisc */
if (!parent) {
q = dev->qdisc;
parent = q->handle;
} else {
q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
if (q == NULL)
return -EINVAL;
}
/* Is it classful? */
cops = q->ops->cl_ops;
if (!cops)
return -EINVAL;
if (!cops->tcf_block)
return -EOPNOTSUPP;
/* Do we search for filter, attached to class? */
if (TC_H_MIN(parent)) {
cl = cops->find(q, parent);
if (cl == 0)
return -ENOENT;
}
/* And the last stroke */
block = cops->tcf_block(q, cl);
if (!block) {
err = -EINVAL;
goto errout;
}
chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
if (chain_index > TC_ACT_EXT_VAL_MASK) {
err = -EINVAL;
goto errout;
}
chain = tcf_chain_get(block, chain_index,
n->nlmsg_type == RTM_NEWTFILTER);
if (!chain) {
err = n->nlmsg_type == RTM_NEWTFILTER ? -ENOMEM : -EINVAL;
goto errout;
}
if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) {
tfilter_notify_chain(net, skb, q, parent, n,
chain, RTM_DELTFILTER);
tcf_chain_flush(chain);
err = 0;
goto errout;
}
tp = tcf_chain_tp_find(chain, &chain_info, protocol,
prio, prio_allocate);
if (IS_ERR(tp)) {
err = PTR_ERR(tp);
goto errout;
}
if (tp == NULL) {
/* Proto-tcf does not exist, create new one */
if (tca[TCA_KIND] == NULL || !protocol) {
err = -EINVAL;
goto errout;
}
if (n->nlmsg_type != RTM_NEWTFILTER ||
!(n->nlmsg_flags & NLM_F_CREATE)) {
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, parent, q, chain);
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)) {
err = -EINVAL;
goto errout;
}
fh = tp->ops->get(tp, t->tcm_handle);
if (!fh) {
if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
tcf_chain_tp_remove(chain, &chain_info, tp);
tfilter_notify(net, skb, n, tp, q, parent, fh,
RTM_DELTFILTER, false);
tcf_proto_destroy(tp);
err = 0;
goto errout;
}
if (n->nlmsg_type != RTM_NEWTFILTER ||
!(n->nlmsg_flags & NLM_F_CREATE)) {
err = -ENOENT;
goto errout;
}
} else {
bool last;
switch (n->nlmsg_type) {
case RTM_NEWTFILTER:
if (n->nlmsg_flags & NLM_F_EXCL) {
if (tp_created)
tcf_proto_destroy(tp);
err = -EEXIST;
goto errout;
}
break;
case RTM_DELTFILTER:
err = tfilter_del_notify(net, skb, n, tp, q, parent,
fh, false, &last);
if (err)
goto errout;
if (last) {
tcf_chain_tp_remove(chain, &chain_info, tp);
tcf_proto_destroy(tp);
}
goto errout;
case RTM_GETTFILTER:
err = tfilter_notify(net, skb, n, tp, q, parent, fh,
RTM_NEWTFILTER, true);
goto errout;
default:
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);
if (err == 0) {
if (tp_created)
tcf_chain_tp_insert(chain, &chain_info, tp);
tfilter_notify(net, skb, n, tp, q, parent, fh,
RTM_NEWTFILTER, false);
} else {
if (tp_created)
tcf_proto_destroy(tp);
}
errout:
if (chain)
tcf_chain_put(chain);
if (err == -EAGAIN)
/* Replay the request. */
goto replay;
return err;
}
struct tcf_dump_args {
struct tcf_walker w;
struct sk_buff *skb;
struct netlink_callback *cb;
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->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 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, q, parent, 0,
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.q = q;
arg.parent = parent;
arg.w.stop = 0;
arg.w.skip = cb->args[1] - 1;
arg.w.count = 0;
tp->ops->walk(tp, &arg.w);
cb->args[1] = arg.w.count + 1;
if (arg.w.stop)
return false;
}
return true;
}
/* called with RTNL */