blob: 641ad7575f24763b3f14a5fa17878765f6781fd8 [file] [log] [blame]
/*
* net/sched/act_api.c Packet action 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.
*
* Author: Jamal Hadi Salim
*
*
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/err.h>
#include <linux/module.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/sch_generic.h>
#include <net/pkt_cls.h>
#include <net/act_api.h>
#include <net/netlink.h>
static void tcf_action_goto_chain_exec(const struct tc_action *a,
struct tcf_result *res)
{
const struct tcf_chain *chain = rcu_dereference_bh(a->goto_chain);
res->goto_tp = rcu_dereference_bh(chain->filter_chain);
}
static void tcf_free_cookie_rcu(struct rcu_head *p)
{
struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
kfree(cookie->data);
kfree(cookie);
}
static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
struct tc_cookie *new_cookie)
{
struct tc_cookie *old;
old = xchg((__force struct tc_cookie **)old_cookie, new_cookie);
if (old)
call_rcu(&old->rcu, tcf_free_cookie_rcu);
}
int tcf_action_check_ctrlact(int action, struct tcf_proto *tp,
struct tcf_chain **newchain,
struct netlink_ext_ack *extack)
{
int opcode = TC_ACT_EXT_OPCODE(action), ret = -EINVAL;
u32 chain_index;
if (!opcode)
ret = action > TC_ACT_VALUE_MAX ? -EINVAL : 0;
else if (opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC)
ret = 0;
if (ret) {
NL_SET_ERR_MSG(extack, "invalid control action");
goto end;
}
if (TC_ACT_EXT_CMP(action, TC_ACT_GOTO_CHAIN)) {
chain_index = action & TC_ACT_EXT_VAL_MASK;
if (!tp || !newchain) {
ret = -EINVAL;
NL_SET_ERR_MSG(extack,
"can't goto NULL proto/chain");
goto end;
}
*newchain = tcf_chain_get_by_act(tp->chain->block, chain_index);
if (!*newchain) {
ret = -ENOMEM;
NL_SET_ERR_MSG(extack,
"can't allocate goto_chain");
}
}
end:
return ret;
}
EXPORT_SYMBOL(tcf_action_check_ctrlact);
struct tcf_chain *tcf_action_set_ctrlact(struct tc_action *a, int action,
struct tcf_chain *goto_chain)
{
a->tcfa_action = action;
rcu_swap_protected(a->goto_chain, goto_chain, 1);
return goto_chain;
}
EXPORT_SYMBOL(tcf_action_set_ctrlact);
/* XXX: For standalone actions, we don't need a RCU grace period either, because
* actions are always connected to filters and filters are already destroyed in
* RCU callbacks, so after a RCU grace period actions are already disconnected
* from filters. Readers later can not find us.
*/
static void free_tcf(struct tc_action *p)
{
struct tcf_chain *chain = rcu_dereference_protected(p->goto_chain, 1);
free_percpu(p->cpu_bstats);
free_percpu(p->cpu_bstats_hw);
free_percpu(p->cpu_qstats);
tcf_set_action_cookie(&p->act_cookie, NULL);
if (chain)
tcf_chain_put_by_act(chain);
kfree(p);
}
static void tcf_action_cleanup(struct tc_action *p)
{
if (p->ops->cleanup)
p->ops->cleanup(p);
gen_kill_estimator(&p->tcfa_rate_est);
free_tcf(p);
}
static int __tcf_action_put(struct tc_action *p, bool bind)
{
struct tcf_idrinfo *idrinfo = p->idrinfo;
if (refcount_dec_and_mutex_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
if (bind)
atomic_dec(&p->tcfa_bindcnt);
idr_remove(&idrinfo->action_idr, p->tcfa_index);
mutex_unlock(&idrinfo->lock);
tcf_action_cleanup(p);
return 1;
}
if (bind)
atomic_dec(&p->tcfa_bindcnt);
return 0;
}
int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
{
int ret = 0;
/* Release with strict==1 and bind==0 is only called through act API
* interface (classifiers always bind). Only case when action with
* positive reference count and zero bind count can exist is when it was
* also created with act API (unbinding last classifier will destroy the
* action if it was created by classifier). So only case when bind count
* can be changed after initial check is when unbound action is
* destroyed by act API while classifier binds to action with same id
* concurrently. This result either creation of new action(same behavior
* as before), or reusing existing action if concurrent process
* increments reference count before action is deleted. Both scenarios
* are acceptable.
*/
if (p) {
if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
return -EPERM;
if (__tcf_action_put(p, bind))
ret = ACT_P_DELETED;
}
return ret;
}
EXPORT_SYMBOL(__tcf_idr_release);
static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
{
struct tc_cookie *act_cookie;
u32 cookie_len = 0;
rcu_read_lock();
act_cookie = rcu_dereference(act->act_cookie);
if (act_cookie)
cookie_len = nla_total_size(act_cookie->len);
rcu_read_unlock();
return nla_total_size(0) /* action number nested */
+ nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
+ cookie_len /* TCA_ACT_COOKIE */
+ nla_total_size(0) /* TCA_ACT_STATS nested */
/* TCA_STATS_BASIC */
+ nla_total_size_64bit(sizeof(struct gnet_stats_basic))
/* TCA_STATS_QUEUE */
+ nla_total_size_64bit(sizeof(struct gnet_stats_queue))
+ nla_total_size(0) /* TCA_OPTIONS nested */
+ nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
}
static size_t tcf_action_full_attrs_size(size_t sz)
{
return NLMSG_HDRLEN /* struct nlmsghdr */
+ sizeof(struct tcamsg)
+ nla_total_size(0) /* TCA_ACT_TAB nested */
+ sz;
}
static size_t tcf_action_fill_size(const struct tc_action *act)
{
size_t sz = tcf_action_shared_attrs_size(act);
if (act->ops->get_fill_size)
return act->ops->get_fill_size(act) + sz;
return sz;
}
static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
struct netlink_callback *cb)
{
int err = 0, index = -1, s_i = 0, n_i = 0;
u32 act_flags = cb->args[2];
unsigned long jiffy_since = cb->args[3];
struct nlattr *nest;
struct idr *idr = &idrinfo->action_idr;
struct tc_action *p;
unsigned long id = 1;
mutex_lock(&idrinfo->lock);
s_i = cb->args[0];
idr_for_each_entry_ul(idr, p, id) {
index++;
if (index < s_i)
continue;
if (jiffy_since &&
time_after(jiffy_since,
(unsigned long)p->tcfa_tm.lastuse))
continue;
nest = nla_nest_start_noflag(skb, n_i);
if (!nest) {
index--;
goto nla_put_failure;
}
err = tcf_action_dump_1(skb, p, 0, 0);
if (err < 0) {
index--;
nlmsg_trim(skb, nest);
goto done;
}
nla_nest_end(skb, nest);
n_i++;
if (!(act_flags & TCA_FLAG_LARGE_DUMP_ON) &&
n_i >= TCA_ACT_MAX_PRIO)
goto done;
}
done:
if (index >= 0)
cb->args[0] = index + 1;
mutex_unlock(&idrinfo->lock);
if (n_i) {
if (act_flags & TCA_FLAG_LARGE_DUMP_ON)
cb->args[1] = n_i;
}
return n_i;
nla_put_failure:
nla_nest_cancel(skb, nest);
goto done;
}
static int tcf_idr_release_unsafe(struct tc_action *p)
{
if (atomic_read(&p->tcfa_bindcnt) > 0)
return -EPERM;
if (refcount_dec_and_test(&p->tcfa_refcnt)) {
idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
tcf_action_cleanup(p);
return ACT_P_DELETED;
}
return 0;
}
static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
const struct tc_action_ops *ops)
{
struct nlattr *nest;
int n_i = 0;
int ret = -EINVAL;
struct idr *idr = &idrinfo->action_idr;
struct tc_action *p;
unsigned long id = 1;
nest = nla_nest_start_noflag(skb, 0);
if (nest == NULL)
goto nla_put_failure;
if (nla_put_string(skb, TCA_KIND, ops->kind))
goto nla_put_failure;
mutex_lock(&idrinfo->lock);
idr_for_each_entry_ul(idr, p, id) {
ret = tcf_idr_release_unsafe(p);
if (ret == ACT_P_DELETED) {
module_put(ops->owner);
n_i++;
} else if (ret < 0) {
mutex_unlock(&idrinfo->lock);
goto nla_put_failure;
}
}
mutex_unlock(&idrinfo->lock);
if (nla_put_u32(skb, TCA_FCNT, n_i))
goto nla_put_failure;
nla_nest_end(skb, nest);
return n_i;
nla_put_failure:
nla_nest_cancel(skb, nest);
return ret;
}
int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
struct netlink_callback *cb, int type,
const struct tc_action_ops *ops,
struct netlink_ext_ack *extack)
{
struct tcf_idrinfo *idrinfo = tn->idrinfo;
if (type == RTM_DELACTION) {
return tcf_del_walker(idrinfo, skb, ops);
} else if (type == RTM_GETACTION) {
return tcf_dump_walker(idrinfo, skb, cb);
} else {
WARN(1, "tcf_generic_walker: unknown command %d\n", type);
NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
return -EINVAL;
}
}
EXPORT_SYMBOL(tcf_generic_walker);
int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
{
struct tcf_idrinfo *idrinfo = tn->idrinfo;
struct tc_action *p;
mutex_lock(&idrinfo->lock);
p = idr_find(&idrinfo->action_idr, index);
if (IS_ERR(p))
p = NULL;
else if (p)
refcount_inc(&p->tcfa_refcnt);
mutex_unlock(&idrinfo->lock);
if (p) {
*a = p;
return true;
}
return false;
}
EXPORT_SYMBOL(tcf_idr_search);
static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
{
struct tc_action *p;
int ret = 0;
mutex_lock(&idrinfo->lock);
p = idr_find(&idrinfo->action_idr, index);
if (!p) {
mutex_unlock(&idrinfo->lock);
return -ENOENT;
}
if (!atomic_read(&p->tcfa_bindcnt)) {
if (refcount_dec_and_test(&p->tcfa_refcnt)) {
struct module *owner = p->ops->owner;
WARN_ON(p != idr_remove(&idrinfo->action_idr,
p->tcfa_index));
mutex_unlock(&idrinfo->lock);
tcf_action_cleanup(p);
module_put(owner);
return 0;
}
ret = 0;
} else {
ret = -EPERM;
}
mutex_unlock(&idrinfo->lock);
return ret;
}
int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
struct tc_action **a, const struct tc_action_ops *ops,
int bind, bool cpustats)
{
struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
struct tcf_idrinfo *idrinfo = tn->idrinfo;
int err = -ENOMEM;
if (unlikely(!p))
return -ENOMEM;
refcount_set(&p->tcfa_refcnt, 1);
if (bind)
atomic_set(&p->tcfa_bindcnt, 1);
if (cpustats) {
p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
if (!p->cpu_bstats)
goto err1;
p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
if (!p->cpu_bstats_hw)
goto err2;
p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
if (!p->cpu_qstats)
goto err3;
}
spin_lock_init(&p->tcfa_lock);
p->tcfa_index = index;
p->tcfa_tm.install = jiffies;
p->tcfa_tm.lastuse = jiffies;
p->tcfa_tm.firstuse = 0;
if (est) {
err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
&p->tcfa_rate_est,
&p->tcfa_lock, NULL, est);
if (err)
goto err4;
}
p->idrinfo = idrinfo;
p->ops = ops;
*a = p;
return 0;
err4:
free_percpu(p->cpu_qstats);
err3:
free_percpu(p->cpu_bstats_hw);
err2:
free_percpu(p->cpu_bstats);
err1:
kfree(p);
return err;
}
EXPORT_SYMBOL(tcf_idr_create);
void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a)
{
struct tcf_idrinfo *idrinfo = tn->idrinfo;
mutex_lock(&idrinfo->lock);
/* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
WARN_ON(!IS_ERR(idr_replace(&idrinfo->action_idr, a, a->tcfa_index)));
mutex_unlock(&idrinfo->lock);
}
EXPORT_SYMBOL(tcf_idr_insert);
/* Cleanup idr index that was allocated but not initialized. */
void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
{
struct tcf_idrinfo *idrinfo = tn->idrinfo;
mutex_lock(&idrinfo->lock);
/* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
mutex_unlock(&idrinfo->lock);
}
EXPORT_SYMBOL(tcf_idr_cleanup);
/* Check if action with specified index exists. If actions is found, increments
* its reference and bind counters, and return 1. Otherwise insert temporary
* error pointer (to prevent concurrent users from inserting actions with same
* index) and return 0.
*/
int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
struct tc_action **a, int bind)
{
struct tcf_idrinfo *idrinfo = tn->idrinfo;
struct tc_action *p;
int ret;
again:
mutex_lock(&idrinfo->lock);
if (*index) {
p = idr_find(&idrinfo->action_idr, *index);
if (IS_ERR(p)) {
/* This means that another process allocated
* index but did not assign the pointer yet.
*/
mutex_unlock(&idrinfo->lock);
goto again;
}
if (p) {
refcount_inc(&p->tcfa_refcnt);
if (bind)
atomic_inc(&p->tcfa_bindcnt);
*a = p;
ret = 1;
} else {
*a = NULL;
ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
*index, GFP_KERNEL);
if (!ret)
idr_replace(&idrinfo->action_idr,
ERR_PTR(-EBUSY), *index);
}
} else {
*index = 1;
*a = NULL;
ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
UINT_MAX, GFP_KERNEL);
if (!ret)
idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
*index);
}
mutex_unlock(&idrinfo->lock);
return ret;
}
EXPORT_SYMBOL(tcf_idr_check_alloc);
void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
struct tcf_idrinfo *idrinfo)
{
struct idr *idr = &idrinfo->action_idr;
struct tc_action *p;
int ret;
unsigned long id = 1;
idr_for_each_entry_ul(idr, p, id) {
ret = __tcf_idr_release(p, false, true);
if (ret == ACT_P_DELETED)
module_put(ops->owner);
else if (ret < 0)
return;
}
idr_destroy(&idrinfo->action_idr);
}
EXPORT_SYMBOL(tcf_idrinfo_destroy);
static LIST_HEAD(act_base);
static DEFINE_RWLOCK(act_mod_lock);
int tcf_register_action(struct tc_action_ops *act,
struct pernet_operations *ops)
{
struct tc_action_ops *a;
int ret;
if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
return -EINVAL;
/* We have to register pernet ops before making the action ops visible,
* otherwise tcf_action_init_1() could get a partially initialized
* netns.
*/
ret = register_pernet_subsys(ops);
if (ret)
return ret;
write_lock(&act_mod_lock);
list_for_each_entry(a, &act_base, head) {
if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
write_unlock(&act_mod_lock);
unregister_pernet_subsys(ops);
return -EEXIST;
}
}
list_add_tail(&act->head, &act_base);
write_unlock(&act_mod_lock);
return 0;
}
EXPORT_SYMBOL(tcf_register_action);
int tcf_unregister_action(struct tc_action_ops *act,
struct pernet_operations *ops)
{
struct tc_action_ops *a;
int err = -ENOENT;
write_lock(&act_mod_lock);
list_for_each_entry(a, &act_base, head) {
if (a == act) {
list_del(&act->head);
err = 0;
break;
}
}
write_unlock(&act_mod_lock);
if (!err)
unregister_pernet_subsys(ops);
return err;
}
EXPORT_SYMBOL(tcf_unregister_action);
/* lookup by name */
static struct tc_action_ops *tc_lookup_action_n(char *kind)
{
struct tc_action_ops *a, *res = NULL;
if (kind) {
read_lock(&act_mod_lock);
list_for_each_entry(a, &act_base, head) {
if (strcmp(kind, a->kind) == 0) {
if (try_module_get(a->owner))
res = a;
break;
}
}
read_unlock(&act_mod_lock);
}
return res;
}
/* lookup by nlattr */
static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
{
struct tc_action_ops *a, *res = NULL;
if (kind) {
read_lock(&act_mod_lock);
list_for_each_entry(a, &act_base, head) {
if (nla_strcmp(kind, a->kind) == 0) {
if (try_module_get(a->owner))
res = a;
break;
}
}
read_unlock(&act_mod_lock);
}
return res;
}
/*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
#define TCA_ACT_MAX_PRIO_MASK 0x1FF
int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
int nr_actions, struct tcf_result *res)
{
u32 jmp_prgcnt = 0;
u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
int i;
int ret = TC_ACT_OK;
if (skb_skip_tc_classify(skb))
return TC_ACT_OK;
restart_act_graph:
for (i = 0; i < nr_actions; i++) {
const struct tc_action *a = actions[i];
if (jmp_prgcnt > 0) {
jmp_prgcnt -= 1;
continue;
}
repeat:
ret = a->ops->act(skb, a, res);
if (ret == TC_ACT_REPEAT)
goto repeat; /* we need a ttl - JHS */
if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
/* faulty opcode, stop pipeline */
return TC_ACT_OK;
} else {
jmp_ttl -= 1;
if (jmp_ttl > 0)
goto restart_act_graph;
else /* faulty graph, stop pipeline */
return TC_ACT_OK;
}
} else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
if (unlikely(!rcu_access_pointer(a->goto_chain))) {
net_warn_ratelimited("can't go to NULL chain!\n");
return TC_ACT_SHOT;
}
tcf_action_goto_chain_exec(a, res);
}
if (ret != TC_ACT_PIPE)
break;
}
return ret;
}
EXPORT_SYMBOL(tcf_action_exec);
int tcf_action_destroy(struct tc_action *actions[], int bind)
{
const struct tc_action_ops *ops;
struct tc_action *a;
int ret = 0, i;
for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
a = actions[i];
actions[i] = NULL;
ops = a->ops;
ret = __tcf_idr_release(a, bind, true);
if (ret == ACT_P_DELETED)
module_put(ops->owner);
else if (ret < 0)
return ret;
}
return ret;
}
static int tcf_action_destroy_1(struct tc_action *a, int bind)
{
struct tc_action *actions[] = { a, NULL };
return tcf_action_destroy(actions, bind);
}
static int tcf_action_put(struct tc_action *p)
{
return __tcf_action_put(p, false);
}
/* Put all actions in this array, skip those NULL's. */
static void tcf_action_put_many(struct tc_action *actions[])
{
int i;
for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
struct tc_action *a = actions[i];
const struct tc_action_ops *ops;
if (!a)
continue;
ops = a->ops;
if (tcf_action_put(a))
module_put(ops->owner);
}
}
int
tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
return a->ops->dump(skb, a, bind, ref);
}
int
tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
int err = -EINVAL;
unsigned char *b = skb_tail_pointer(skb);
struct nlattr *nest;
struct tc_cookie *cookie;
if (nla_put_string(skb, TCA_KIND, a->ops->kind))
goto nla_put_failure;
if (tcf_action_copy_stats(skb, a, 0))
goto nla_put_failure;
rcu_read_lock();
cookie = rcu_dereference(a->act_cookie);
if (cookie) {
if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
rcu_read_unlock();
goto nla_put_failure;
}
}
rcu_read_unlock();
nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
if (nest == NULL)
goto nla_put_failure;
err = tcf_action_dump_old(skb, a, bind, ref);
if (err > 0) {
nla_nest_end(skb, nest);
return err;
}
nla_put_failure:
nlmsg_trim(skb, b);
return -1;
}
EXPORT_SYMBOL(tcf_action_dump_1);
int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
int bind, int ref)
{
struct tc_action *a;
int err = -EINVAL, i;
struct nlattr *nest;
for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
a = actions[i];
nest = nla_nest_start_noflag(skb, a->order);
if (nest == NULL)
goto nla_put_failure;
err = tcf_action_dump_1(skb, a, bind, ref);
if (err < 0)
goto errout;
nla_nest_end(skb, nest);
}
return 0;
nla_put_failure:
err = -EINVAL;
errout:
nla_nest_cancel(skb, nest);
return err;
}
static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
{
struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
if (!c)
return NULL;
c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
if (!c->data) {
kfree(c);
return NULL;
}
c->len = nla_len(tb[TCA_ACT_COOKIE]);
return c;
}
struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
struct nlattr *nla, struct nlattr *est,
char *name, int ovr, int bind,
bool rtnl_held,
struct netlink_ext_ack *extack)
{
struct tc_action *a;
struct tc_action_ops *a_o;
struct tc_cookie *cookie = NULL;
char act_name[IFNAMSIZ];
struct nlattr *tb[TCA_ACT_MAX + 1];
struct nlattr *kind;
int err;
if (name == NULL) {
err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
if (err < 0)
goto err_out;
err = -EINVAL;
kind = tb[TCA_ACT_KIND];
if (!kind) {
NL_SET_ERR_MSG(extack, "TC action kind must be specified");
goto err_out;
}
if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
NL_SET_ERR_MSG(extack, "TC action name too long");
goto err_out;
}
if (tb[TCA_ACT_COOKIE]) {
int cklen = nla_len(tb[TCA_ACT_COOKIE]);
if (cklen > TC_COOKIE_MAX_SIZE) {
NL_SET_ERR_MSG(extack, "TC cookie size above the maximum");
goto err_out;
}
cookie = nla_memdup_cookie(tb);
if (!cookie) {
NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
err = -ENOMEM;
goto err_out;
}
}
} else {
if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
NL_SET_ERR_MSG(extack, "TC action name too long");
err = -EINVAL;
goto err_out;
}
}
a_o = tc_lookup_action_n(act_name);
if (a_o == NULL) {
#ifdef CONFIG_MODULES
if (rtnl_held)
rtnl_unlock();
request_module("act_%s", act_name);
if (rtnl_held)
rtnl_lock();
a_o = tc_lookup_action_n(act_name);
/* We dropped the RTNL semaphore in order to
* perform the module load. So, even if we
* succeeded in loading the module we have to
* tell the caller to replay the request. We
* indicate this using -EAGAIN.
*/
if (a_o != NULL) {
err = -EAGAIN;
goto err_mod;
}
#endif
NL_SET_ERR_MSG(extack, "Failed to load TC action module");
err = -ENOENT;
goto err_out;
}
/* backward compatibility for policer */
if (name == NULL)
err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
rtnl_held, tp, extack);
else
err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
tp, extack);
if (err < 0)
goto err_mod;
if (!name && tb[TCA_ACT_COOKIE])
tcf_set_action_cookie(&a->act_cookie, cookie);
/* module count goes up only when brand new policy is created
* if it exists and is only bound to in a_o->init() then
* ACT_P_CREATED is not returned (a zero is).
*/
if (err != ACT_P_CREATED)
module_put(a_o->owner);
if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN) &&
!rcu_access_pointer(a->goto_chain)) {
tcf_action_destroy_1(a, bind);
NL_SET_ERR_MSG(extack, "can't use goto chain with NULL chain");
return ERR_PTR(-EINVAL);
}
return a;
err_mod:
module_put(a_o->owner);
err_out:
if (cookie) {
kfree(cookie->data);
kfree(cookie);
}
return ERR_PTR(err);
}
/* Returns numbers of initialized actions or negative error. */
int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
struct nlattr *est, char *name, int ovr, int bind,
struct tc_action *actions[], size_t *attr_size,
bool rtnl_held, struct netlink_ext_ack *extack)
{
struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
struct tc_action *act;
size_t sz = 0;
int err;
int i;
err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, extack);
if (err < 0)
return err;
for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
rtnl_held, extack);
if (IS_ERR(act)) {
err = PTR_ERR(act);
goto err;
}
act->order = i;
sz += tcf_action_fill_size(act);
/* Start from index 0 */
actions[i - 1] = act;
}
*attr_size = tcf_action_full_attrs_size(sz);
return i - 1;
err:
tcf_action_destroy(actions, bind);
return err;
}
int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
int compat_mode)
{
int err = 0;
struct gnet_dump d;
if (p == NULL)
goto errout;
/* compat_mode being true specifies a call that is supposed
* to add additional backward compatibility statistic TLVs.
*/
if (compat_mode) {
if (p->type == TCA_OLD_COMPAT)
err = gnet_stats_start_copy_compat(skb, 0,
TCA_STATS,
TCA_XSTATS,
&p->tcfa_lock, &d,
TCA_PAD);
else
return 0;
} else
err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
&p->tcfa_lock, &d, TCA_ACT_PAD);
if (err < 0)
goto errout;
if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
&p->tcfa_bstats_hw) < 0 ||
gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
gnet_stats_copy_queue(&d, p->cpu_qstats,
&p->tcfa_qstats,
p->tcfa_qstats.qlen) < 0)
goto errout;
if (gnet_stats_finish_copy(&d) < 0)
goto errout;
return 0;
errout:
return -1;
}
static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
u32 portid, u32 seq, u16 flags, int event, int bind,
int ref)
{
struct tcamsg *t;
struct nlmsghdr *nlh;
unsigned char *b = skb_tail_pointer(skb);
struct nlattr *nest;
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
if (!nlh)
goto out_nlmsg_trim;
t = nlmsg_data(nlh);
t->tca_family = AF_UNSPEC;
t->tca__pad1 = 0;
t->tca__pad2 = 0;
nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
if (!nest)
goto out_nlmsg_trim;
if (tcf_action_dump(skb, actions, bind, ref) < 0)
goto out_nlmsg_trim;
nla_nest_end(skb, nest);
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
return skb->len;
out_nlmsg_trim:
nlmsg_trim(skb, b);
return -1;
}
static int
tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
struct tc_action *actions[], int event,
struct netlink_ext_ack *extack)
{
struct sk_buff *skb;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return -ENOBUFS;
if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
0, 1) <= 0) {
NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
kfree_skb(skb);
return -EINVAL;
}
return rtnl_unicast(skb, net, portid);
}
static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
struct nlmsghdr *n, u32 portid,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[TCA_ACT_MAX + 1];
const struct tc_action_ops *ops;
struct tc_action *a;
int index;
int err;
err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
if (err < 0)
goto err_out;
err = -EINVAL;
if (tb[TCA_ACT_INDEX] == NULL ||
nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
NL_SET_ERR_MSG(extack, "Invalid TC action index value");
goto err_out;
}
index = nla_get_u32(tb[TCA_ACT_INDEX]);
err = -EINVAL;
ops = tc_lookup_action(tb[TCA_ACT_KIND]);
if (!ops) { /* could happen in batch of actions */
NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
goto err_out;
}
err = -ENOENT;
if (ops->lookup(net, &a, index) == 0) {
NL_SET_ERR_MSG(extack, "TC action with specified index not found");
goto err_mod;
}
module_put(ops->owner);
return a;
err_mod:
module_put(ops->owner);
err_out:
return ERR_PTR(err);
}
static int tca_action_flush(struct net *net, struct nlattr *nla,
struct nlmsghdr *n, u32 portid,
struct netlink_ext_ack *extack)
{
struct sk_buff *skb;
unsigned char *b;
struct nlmsghdr *nlh;
struct tcamsg *t;
struct netlink_callback dcb;
struct nlattr *nest;
struct nlattr *tb[TCA_ACT_MAX + 1];
const struct tc_action_ops *ops;
struct nlattr *kind;
int err = -ENOMEM;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return err;
b = skb_tail_pointer(skb);
err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
if (err < 0)
goto err_out;
err = -EINVAL;
kind = tb[TCA_ACT_KIND];
ops = tc_lookup_action(kind);
if (!ops) { /*some idjot trying to flush unknown action */
NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
goto err_out;
}
nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
sizeof(*t), 0);
if (!nlh) {
NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
goto out_module_put;
}
t = nlmsg_data(nlh);
t->tca_family = AF_UNSPEC;
t->tca__pad1 = 0;
t->tca__pad2 = 0;
nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
if (!nest) {
NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
goto out_module_put;
}
err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
if (err <= 0) {
nla_nest_cancel(skb, nest);
goto out_module_put;
}
nla_nest_end(skb, nest);
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
nlh->nlmsg_flags |= NLM_F_ROOT;
module_put(ops->owner);
err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
n->nlmsg_flags & NLM_F_ECHO);
if (err > 0)
return 0;
if (err < 0)
NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
return err;
out_module_put:
module_put(ops->owner);
err_out:
kfree_skb(skb);
return err;
}
static int tcf_action_delete(struct net *net, struct tc_action *actions[])
{
int i;
for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
struct tc_action *a = actions[i];
const struct tc_action_ops *ops = a->ops;
/* Actions can be deleted concurrently so we must save their
* type and id to search again after reference is released.
*/
struct tcf_idrinfo *idrinfo = a->idrinfo;
u32 act_index = a->tcfa_index;
actions[i] = NULL;
if (tcf_action_put(a)) {
/* last reference, action was deleted concurrently */
module_put(ops->owner);
} else {
int ret;
/* now do the delete */
ret = tcf_idr_delete_index(idrinfo, act_index);
if (ret < 0)
return ret;
}
}
return 0;
}
static int
tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
{
int ret;
struct sk_buff *skb;
skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
GFP_KERNEL);
if (!skb)
return -ENOBUFS;
if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
0, 2) <= 0) {
NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
kfree_skb(skb);
return -EINVAL;
}
/* now do the delete */
ret = tcf_action_delete(net, actions);
if (ret < 0) {
NL_SET_ERR_MSG(extack, "Failed to delete TC action");
kfree_skb(skb);
return ret;
}
ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
n->nlmsg_flags & NLM_F_ECHO);
if (ret > 0)
return 0;
return ret;
}
static int
tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
u32 portid, int event, struct netlink_ext_ack *extack)
{
int i, ret;
struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
struct tc_action *act;
size_t attr_size = 0;
struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, extack);
if (ret < 0)
return ret;
if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
if (tb[1])
return tca_action_flush(net, tb[1], n, portid, extack);
NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
return -EINVAL;
}
for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
act = tcf_action_get_1(net, tb[i], n, portid, extack);
if (IS_ERR(act)) {
ret = PTR_ERR(act);
goto err;
}
act->order = i;
attr_size += tcf_action_fill_size(act);
actions[i - 1] = act;
}
attr_size = tcf_action_full_attrs_size(attr_size);
if (event == RTM_GETACTION)
ret = tcf_get_notify(net, portid, n, actions, event, extack);
else { /* delete */
ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
if (ret)
goto err;
return 0;
}
err:
tcf_action_put_many(actions);
return ret;
}
static int
tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
{
struct sk_buff *skb;
int err = 0;
skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
GFP_KERNEL);
if (!skb)
return -ENOBUFS;
if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
RTM_NEWACTION, 0, 0) <= 0) {
NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
kfree_skb(skb);
return -EINVAL;
}
err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
n->nlmsg_flags & NLM_F_ECHO);
if (err > 0)
err = 0;
return err;
}
static int tcf_action_add(struct net *net, struct nlattr *nla,
struct nlmsghdr *n, u32 portid, int ovr,
struct netlink_ext_ack *extack)
{
size_t attr_size = 0;
int ret = 0;
struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0, actions,
&attr_size, true, extack);
if (ret < 0)
return ret;
ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
if (ovr)
tcf_action_put_many(actions);
return ret;
}
static u32 tcaa_root_flags_allowed = TCA_FLAG_LARGE_DUMP_ON;
static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
[TCA_ROOT_FLAGS] = { .type = NLA_BITFIELD32,
.validation_data = &tcaa_root_flags_allowed },
[TCA_ROOT_TIME_DELTA] = { .type = NLA_U32 },
};
static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct nlattr *tca[TCA_ROOT_MAX + 1];
u32 portid = skb ? NETLINK_CB(skb).portid : 0;
int ret = 0, ovr = 0;
if ((n->nlmsg_type != RTM_GETACTION) &&
!netlink_capable(skb, CAP_NET_ADMIN))
return -EPERM;
ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ROOT_MAX, NULL,
extack);
if (ret < 0)
return ret;
if (tca[TCA_ACT_TAB] == NULL) {
NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
return -EINVAL;
}
/* n->nlmsg_flags & NLM_F_CREATE */
switch (n->nlmsg_type) {
case RTM_NEWACTION:
/* we are going to assume all other flags
* imply create only if it doesn't exist
* Note that CREATE | EXCL implies that
* but since we want avoid ambiguity (eg when flags
* is zero) then just set this
*/
if (n->nlmsg_flags & NLM_F_REPLACE)
ovr = 1;
replay:
ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
extack);
if (ret == -EAGAIN)
goto replay;
break;
case RTM_DELACTION:
ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
portid, RTM_DELACTION, extack);
break;
case RTM_GETACTION:
ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
portid, RTM_GETACTION, extack);
break;
default:
BUG();
}
return ret;
}
static struct nlattr *find_dump_kind(struct nlattr **nla)
{
struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
struct nlattr *kind;
tb1 = nla[TCA_ACT_TAB];
if (tb1 == NULL)
return NULL;
if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
return NULL;
if (tb[1] == NULL)
return NULL;
if (nla_parse_nested(tb2, TCA_ACT_MAX, tb[1], NULL, NULL) < 0)
return NULL;
kind = tb2[TCA_ACT_KIND];
return kind;
}
static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct nlmsghdr *nlh;
unsigned char *b = skb_tail_pointer(skb);
struct nlattr *nest;
struct tc_action_ops *a_o;
int ret = 0;
struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
struct nlattr *tb[TCA_ROOT_MAX + 1];
struct nlattr *count_attr = NULL;
unsigned long jiffy_since = 0;
struct nlattr *kind = NULL;
struct nla_bitfield32 bf;
u32 msecs_since = 0;
u32 act_count = 0;
ret = nlmsg_parse(cb->nlh, sizeof(struct tcamsg), tb, TCA_ROOT_MAX,
tcaa_policy, cb->extack);
if (ret < 0)
return ret;
kind = find_dump_kind(tb);
if (kind == NULL) {
pr_info("tc_dump_action: action bad kind\n");
return 0;
}
a_o = tc_lookup_action(kind);
if (a_o == NULL)
return 0;
cb->args[2] = 0;
if (tb[TCA_ROOT_FLAGS]) {
bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
cb->args[2] = bf.value;
}
if (tb[TCA_ROOT_TIME_DELTA]) {
msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
}
nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
cb->nlh->nlmsg_type, sizeof(*t), 0);
if (!nlh)
goto out_module_put;
if (msecs_since)
jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
t = nlmsg_data(nlh);
t->tca_family = AF_UNSPEC;
t->tca__pad1 = 0;
t->tca__pad2 = 0;
cb->args[3] = jiffy_since;
count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
if (!count_attr)
goto out_module_put;
nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
if (nest == NULL)
goto out_module_put;
ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
if (ret < 0)
goto out_module_put;
if (ret > 0) {
nla_nest_end(skb, nest);
ret = skb->len;
act_count = cb->args[1];
memcpy(nla_data(count_attr), &act_count, sizeof(u32));
cb->args[1] = 0;
} else
nlmsg_trim(skb, b);
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
if (NETLINK_CB(cb->skb).portid && ret)
nlh->nlmsg_flags |= NLM_F_MULTI;
module_put(a_o->owner);
return skb->len;
out_module_put:
module_put(a_o->owner);
nlmsg_trim(skb, b);
return skb->len;
}
static int __init tc_action_init(void)
{
rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
0);
return 0;
}
subsys_initcall(tc_action_init);