linux/net/sched/act_api.c
Eric Dumazet c7de2cf053 pkt_sched: gen_kill_estimator() rcu fixes
gen_kill_estimator() API is incomplete or not well documented, since
caller should make sure an RCU grace period is respected before
freeing stats_lock.

This was partially addressed in commit 5d944c640b
(gen_estimator: deadlock fix), but same problem exist for all
gen_kill_estimator() users, if lock they use is not already RCU
protected.

A code review shows xt_RATEEST.c, act_api.c, act_police.c have this
problem. Other are ok because they use qdisc lock, already RCU
protected.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-11 18:37:08 -07:00

1131 lines
24 KiB
C

/*
* 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 <net/net_namespace.h>
#include <net/sock.h>
#include <net/sch_generic.h>
#include <net/act_api.h>
#include <net/netlink.h>
static void tcf_common_free_rcu(struct rcu_head *head)
{
kfree(container_of(head, struct tcf_common, tcfc_rcu));
}
void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
{
unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
struct tcf_common **p1p;
for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
if (*p1p == p) {
write_lock_bh(hinfo->lock);
*p1p = p->tcfc_next;
write_unlock_bh(hinfo->lock);
gen_kill_estimator(&p->tcfc_bstats,
&p->tcfc_rate_est);
/*
* gen_estimator est_timer() might access p->tcfc_lock
* or bstats, wait a RCU grace period before freeing p
*/
call_rcu(&p->tcfc_rcu, tcf_common_free_rcu);
return;
}
}
WARN_ON(1);
}
EXPORT_SYMBOL(tcf_hash_destroy);
int tcf_hash_release(struct tcf_common *p, int bind,
struct tcf_hashinfo *hinfo)
{
int ret = 0;
if (p) {
if (bind)
p->tcfc_bindcnt--;
p->tcfc_refcnt--;
if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
tcf_hash_destroy(p, hinfo);
ret = 1;
}
}
return ret;
}
EXPORT_SYMBOL(tcf_hash_release);
static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
struct tc_action *a, struct tcf_hashinfo *hinfo)
{
struct tcf_common *p;
int err = 0, index = -1,i = 0, s_i = 0, n_i = 0;
struct nlattr *nest;
read_lock_bh(hinfo->lock);
s_i = cb->args[0];
for (i = 0; i < (hinfo->hmask + 1); i++) {
p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
for (; p; p = p->tcfc_next) {
index++;
if (index < s_i)
continue;
a->priv = p;
a->order = n_i;
nest = nla_nest_start(skb, a->order);
if (nest == NULL)
goto nla_put_failure;
err = tcf_action_dump_1(skb, a, 0, 0);
if (err < 0) {
index--;
nlmsg_trim(skb, nest);
goto done;
}
nla_nest_end(skb, nest);
n_i++;
if (n_i >= TCA_ACT_MAX_PRIO)
goto done;
}
}
done:
read_unlock_bh(hinfo->lock);
if (n_i)
cb->args[0] += n_i;
return n_i;
nla_put_failure:
nla_nest_cancel(skb, nest);
goto done;
}
static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
struct tcf_hashinfo *hinfo)
{
struct tcf_common *p, *s_p;
struct nlattr *nest;
int i= 0, n_i = 0;
nest = nla_nest_start(skb, a->order);
if (nest == NULL)
goto nla_put_failure;
NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
for (i = 0; i < (hinfo->hmask + 1); i++) {
p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
while (p != NULL) {
s_p = p->tcfc_next;
if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
module_put(a->ops->owner);
n_i++;
p = s_p;
}
}
NLA_PUT_U32(skb, TCA_FCNT, n_i);
nla_nest_end(skb, nest);
return n_i;
nla_put_failure:
nla_nest_cancel(skb, nest);
return -EINVAL;
}
int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
int type, struct tc_action *a)
{
struct tcf_hashinfo *hinfo = a->ops->hinfo;
if (type == RTM_DELACTION) {
return tcf_del_walker(skb, a, hinfo);
} else if (type == RTM_GETACTION) {
return tcf_dump_walker(skb, cb, a, hinfo);
} else {
WARN(1, "tcf_generic_walker: unknown action %d\n", type);
return -EINVAL;
}
}
EXPORT_SYMBOL(tcf_generic_walker);
struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
{
struct tcf_common *p;
read_lock_bh(hinfo->lock);
for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
p = p->tcfc_next) {
if (p->tcfc_index == index)
break;
}
read_unlock_bh(hinfo->lock);
return p;
}
EXPORT_SYMBOL(tcf_hash_lookup);
u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
{
u32 val = *idx_gen;
do {
if (++val == 0)
val = 1;
} while (tcf_hash_lookup(val, hinfo));
return (*idx_gen = val);
}
EXPORT_SYMBOL(tcf_hash_new_index);
int tcf_hash_search(struct tc_action *a, u32 index)
{
struct tcf_hashinfo *hinfo = a->ops->hinfo;
struct tcf_common *p = tcf_hash_lookup(index, hinfo);
if (p) {
a->priv = p;
return 1;
}
return 0;
}
EXPORT_SYMBOL(tcf_hash_search);
struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
struct tcf_hashinfo *hinfo)
{
struct tcf_common *p = NULL;
if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
if (bind)
p->tcfc_bindcnt++;
p->tcfc_refcnt++;
a->priv = p;
}
return p;
}
EXPORT_SYMBOL(tcf_hash_check);
struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
struct tc_action *a, int size, int bind,
u32 *idx_gen, struct tcf_hashinfo *hinfo)
{
struct tcf_common *p = kzalloc(size, GFP_KERNEL);
if (unlikely(!p))
return ERR_PTR(-ENOMEM);
p->tcfc_refcnt = 1;
if (bind)
p->tcfc_bindcnt = 1;
spin_lock_init(&p->tcfc_lock);
p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
p->tcfc_tm.install = jiffies;
p->tcfc_tm.lastuse = jiffies;
if (est) {
int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
&p->tcfc_lock, est);
if (err) {
kfree(p);
return ERR_PTR(err);
}
}
a->priv = (void *) p;
return p;
}
EXPORT_SYMBOL(tcf_hash_create);
void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
{
unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
write_lock_bh(hinfo->lock);
p->tcfc_next = hinfo->htab[h];
hinfo->htab[h] = p;
write_unlock_bh(hinfo->lock);
}
EXPORT_SYMBOL(tcf_hash_insert);
static struct tc_action_ops *act_base = NULL;
static DEFINE_RWLOCK(act_mod_lock);
int tcf_register_action(struct tc_action_ops *act)
{
struct tc_action_ops *a, **ap;
write_lock(&act_mod_lock);
for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
write_unlock(&act_mod_lock);
return -EEXIST;
}
}
act->next = NULL;
*ap = act;
write_unlock(&act_mod_lock);
return 0;
}
EXPORT_SYMBOL(tcf_register_action);
int tcf_unregister_action(struct tc_action_ops *act)
{
struct tc_action_ops *a, **ap;
int err = -ENOENT;
write_lock(&act_mod_lock);
for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
if (a == act)
break;
if (a) {
*ap = a->next;
a->next = NULL;
err = 0;
}
write_unlock(&act_mod_lock);
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 = NULL;
if (kind) {
read_lock(&act_mod_lock);
for (a = act_base; a; a = a->next) {
if (strcmp(kind, a->kind) == 0) {
if (!try_module_get(a->owner)) {
read_unlock(&act_mod_lock);
return NULL;
}
break;
}
}
read_unlock(&act_mod_lock);
}
return a;
}
/* lookup by nlattr */
static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
{
struct tc_action_ops *a = NULL;
if (kind) {
read_lock(&act_mod_lock);
for (a = act_base; a; a = a->next) {
if (nla_strcmp(kind, a->kind) == 0) {
if (!try_module_get(a->owner)) {
read_unlock(&act_mod_lock);
return NULL;
}
break;
}
}
read_unlock(&act_mod_lock);
}
return a;
}
#if 0
/* lookup by id */
static struct tc_action_ops *tc_lookup_action_id(u32 type)
{
struct tc_action_ops *a = NULL;
if (type) {
read_lock(&act_mod_lock);
for (a = act_base; a; a = a->next) {
if (a->type == type) {
if (!try_module_get(a->owner)) {
read_unlock(&act_mod_lock);
return NULL;
}
break;
}
}
read_unlock(&act_mod_lock);
}
return a;
}
#endif
int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
struct tcf_result *res)
{
struct tc_action *a;
int ret = -1;
if (skb->tc_verd & TC_NCLS) {
skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
ret = TC_ACT_OK;
goto exec_done;
}
while ((a = act) != NULL) {
repeat:
if (a->ops && a->ops->act) {
ret = a->ops->act(skb, a, res);
if (TC_MUNGED & skb->tc_verd) {
/* copied already, allow trampling */
skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
}
if (ret == TC_ACT_REPEAT)
goto repeat; /* we need a ttl - JHS */
if (ret != TC_ACT_PIPE)
goto exec_done;
}
act = a->next;
}
exec_done:
return ret;
}
EXPORT_SYMBOL(tcf_action_exec);
void tcf_action_destroy(struct tc_action *act, int bind)
{
struct tc_action *a;
for (a = act; a; a = act) {
if (a->ops && a->ops->cleanup) {
if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
module_put(a->ops->owner);
act = act->next;
kfree(a);
} else {
/*FIXME: Remove later - catch insertion bugs*/
WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
act = act->next;
kfree(a);
}
}
}
int
tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
int err = -EINVAL;
if (a->ops == NULL || a->ops->dump == NULL)
return err;
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;
if (a->ops == NULL || a->ops->dump == NULL)
return err;
NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
if (tcf_action_copy_stats(skb, a, 0))
goto nla_put_failure;
nest = nla_nest_start(skb, TCA_OPTIONS);
if (nest == NULL)
goto nla_put_failure;
if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 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 *act, int bind, int ref)
{
struct tc_action *a;
int err = -EINVAL;
struct nlattr *nest;
while ((a = act) != NULL) {
act = a->next;
nest = nla_nest_start(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;
}
struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
char *name, int ovr, int bind)
{
struct tc_action *a;
struct tc_action_ops *a_o;
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);
if (err < 0)
goto err_out;
err = -EINVAL;
kind = tb[TCA_ACT_KIND];
if (kind == NULL)
goto err_out;
if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
goto err_out;
} else {
err = -EINVAL;
if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
goto err_out;
}
a_o = tc_lookup_action_n(act_name);
if (a_o == NULL) {
#ifdef CONFIG_MODULES
rtnl_unlock();
request_module("act_%s", act_name);
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
err = -ENOENT;
goto err_out;
}
err = -ENOMEM;
a = kzalloc(sizeof(*a), GFP_KERNEL);
if (a == NULL)
goto err_mod;
/* backward compatibility for policer */
if (name == NULL)
err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
else
err = a_o->init(nla, est, a, ovr, bind);
if (err < 0)
goto err_free;
/* 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);
a->ops = a_o;
return a;
err_free:
kfree(a);
err_mod:
module_put(a_o->owner);
err_out:
return ERR_PTR(err);
}
struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
char *name, int ovr, int bind)
{
struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
struct tc_action *head = NULL, *act, *act_prev = NULL;
int err;
int i;
err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
if (err < 0)
return ERR_PTR(err);
for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
act = tcf_action_init_1(tb[i], est, name, ovr, bind);
if (IS_ERR(act))
goto err;
act->order = i;
if (head == NULL)
head = act;
else
act_prev->next = act;
act_prev = act;
}
return head;
err:
if (head != NULL)
tcf_action_destroy(head, bind);
return act;
}
int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
int compat_mode)
{
int err = 0;
struct gnet_dump d;
struct tcf_act_hdr *h = a->priv;
if (h == NULL)
goto errout;
/* compat_mode being true specifies a call that is supposed
* to add additional backward compatibility statistic TLVs.
*/
if (compat_mode) {
if (a->type == TCA_OLD_COMPAT)
err = gnet_stats_start_copy_compat(skb, 0,
TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
else
return 0;
} else
err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
&h->tcf_lock, &d);
if (err < 0)
goto errout;
if (a->ops != NULL && a->ops->get_stats != NULL)
if (a->ops->get_stats(skb, a) < 0)
goto errout;
if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
&h->tcf_rate_est) < 0 ||
gnet_stats_copy_queue(&d, &h->tcf_qstats) < 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 *a, u32 pid, 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_NEW(skb, pid, seq, event, sizeof(*t), flags);
t = NLMSG_DATA(nlh);
t->tca_family = AF_UNSPEC;
t->tca__pad1 = 0;
t->tca__pad2 = 0;
nest = nla_nest_start(skb, TCA_ACT_TAB);
if (nest == NULL)
goto nla_put_failure;
if (tcf_action_dump(skb, a, bind, ref) < 0)
goto nla_put_failure;
nla_nest_end(skb, nest);
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
return skb->len;
nla_put_failure:
nlmsg_failure:
nlmsg_trim(skb, b);
return -1;
}
static int
act_get_notify(struct net *net, u32 pid, struct nlmsghdr *n,
struct tc_action *a, int event)
{
struct sk_buff *skb;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return -ENOBUFS;
if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
kfree_skb(skb);
return -EINVAL;
}
return rtnl_unicast(skb, net, pid);
}
static struct tc_action *
tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
{
struct nlattr *tb[TCA_ACT_MAX+1];
struct tc_action *a;
int index;
int err;
err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
if (err < 0)
goto err_out;
err = -EINVAL;
if (tb[TCA_ACT_INDEX] == NULL ||
nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
goto err_out;
index = nla_get_u32(tb[TCA_ACT_INDEX]);
err = -ENOMEM;
a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
if (a == NULL)
goto err_out;
err = -EINVAL;
a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
if (a->ops == NULL)
goto err_free;
if (a->ops->lookup == NULL)
goto err_mod;
err = -ENOENT;
if (a->ops->lookup(a, index) == 0)
goto err_mod;
module_put(a->ops->owner);
return a;
err_mod:
module_put(a->ops->owner);
err_free:
kfree(a);
err_out:
return ERR_PTR(err);
}
static void cleanup_a(struct tc_action *act)
{
struct tc_action *a;
for (a = act; a; a = act) {
act = a->next;
kfree(a);
}
}
static struct tc_action *create_a(int i)
{
struct tc_action *act;
act = kzalloc(sizeof(*act), GFP_KERNEL);
if (act == NULL) {
pr_debug("create_a: failed to alloc!\n");
return NULL;
}
act->order = i;
return act;
}
static int tca_action_flush(struct net *net, struct nlattr *nla,
struct nlmsghdr *n, u32 pid)
{
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];
struct nlattr *kind;
struct tc_action *a = create_a(0);
int err = -ENOMEM;
if (a == NULL) {
pr_debug("tca_action_flush: couldnt create tc_action\n");
return err;
}
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb) {
pr_debug("tca_action_flush: failed skb alloc\n");
kfree(a);
return err;
}
b = skb_tail_pointer(skb);
err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
if (err < 0)
goto err_out;
err = -EINVAL;
kind = tb[TCA_ACT_KIND];
a->ops = tc_lookup_action(kind);
if (a->ops == NULL)
goto err_out;
nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
t = NLMSG_DATA(nlh);
t->tca_family = AF_UNSPEC;
t->tca__pad1 = 0;
t->tca__pad2 = 0;
nest = nla_nest_start(skb, TCA_ACT_TAB);
if (nest == NULL)
goto nla_put_failure;
err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
if (err < 0)
goto nla_put_failure;
if (err == 0)
goto noflush_out;
nla_nest_end(skb, nest);
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
nlh->nlmsg_flags |= NLM_F_ROOT;
module_put(a->ops->owner);
kfree(a);
err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
if (err > 0)
return 0;
return err;
nla_put_failure:
nlmsg_failure:
module_put(a->ops->owner);
err_out:
noflush_out:
kfree_skb(skb);
kfree(a);
return err;
}
static int
tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
u32 pid, int event)
{
int i, ret;
struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
struct tc_action *head = NULL, *act, *act_prev = NULL;
ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
if (ret < 0)
return ret;
if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
if (tb[1] != NULL)
return tca_action_flush(net, tb[1], n, pid);
else
return -EINVAL;
}
for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
act = tcf_action_get_1(tb[i], n, pid);
if (IS_ERR(act)) {
ret = PTR_ERR(act);
goto err;
}
act->order = i;
if (head == NULL)
head = act;
else
act_prev->next = act;
act_prev = act;
}
if (event == RTM_GETACTION)
ret = act_get_notify(net, pid, n, head, event);
else { /* delete */
struct sk_buff *skb;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb) {
ret = -ENOBUFS;
goto err;
}
if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
0, 1) <= 0) {
kfree_skb(skb);
ret = -EINVAL;
goto err;
}
/* now do the delete */
tcf_action_destroy(head, 0);
ret = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
n->nlmsg_flags&NLM_F_ECHO);
if (ret > 0)
return 0;
return ret;
}
err:
cleanup_a(head);
return ret;
}
static int tcf_add_notify(struct net *net, struct tc_action *a,
u32 pid, u32 seq, int event, u16 flags)
{
struct tcamsg *t;
struct nlmsghdr *nlh;
struct sk_buff *skb;
struct nlattr *nest;
unsigned char *b;
int err = 0;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return -ENOBUFS;
b = skb_tail_pointer(skb);
nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
t = NLMSG_DATA(nlh);
t->tca_family = AF_UNSPEC;
t->tca__pad1 = 0;
t->tca__pad2 = 0;
nest = nla_nest_start(skb, TCA_ACT_TAB);
if (nest == NULL)
goto nla_put_failure;
if (tcf_action_dump(skb, a, 0, 0) < 0)
goto nla_put_failure;
nla_nest_end(skb, nest);
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
NETLINK_CB(skb).dst_group = RTNLGRP_TC;
err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
if (err > 0)
err = 0;
return err;
nla_put_failure:
nlmsg_failure:
kfree_skb(skb);
return -1;
}
static int
tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
u32 pid, int ovr)
{
int ret = 0;
struct tc_action *act;
struct tc_action *a;
u32 seq = n->nlmsg_seq;
act = tcf_action_init(nla, NULL, NULL, ovr, 0);
if (act == NULL)
goto done;
if (IS_ERR(act)) {
ret = PTR_ERR(act);
goto done;
}
/* dump then free all the actions after update; inserted policy
* stays intact
* */
ret = tcf_add_notify(net, act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
for (a = act; a; a = act) {
act = a->next;
kfree(a);
}
done:
return ret;
}
static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
{
struct net *net = sock_net(skb->sk);
struct nlattr *tca[TCA_ACT_MAX + 1];
u32 pid = skb ? NETLINK_CB(skb).pid : 0;
int ret = 0, ovr = 0;
ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
if (ret < 0)
return ret;
if (tca[TCA_ACT_TAB] == NULL) {
pr_notice("tc_ctl_action: received NO action attribs\n");
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 doesnt 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, pid, ovr);
if (ret == -EAGAIN)
goto replay;
break;
case RTM_DELACTION:
ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
pid, RTM_DELACTION);
break;
case RTM_GETACTION:
ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
pid, RTM_GETACTION);
break;
default:
BUG();
}
return ret;
}
static struct nlattr *
find_dump_kind(const struct nlmsghdr *n)
{
struct nlattr *tb1, *tb2[TCA_ACT_MAX+1];
struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
struct nlattr *nla[TCAA_MAX + 1];
struct nlattr *kind;
if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
return NULL;
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) < 0)
return NULL;
if (tb[1] == NULL)
return NULL;
if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
nla_len(tb[1]), 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 nlmsghdr *nlh;
unsigned char *b = skb_tail_pointer(skb);
struct nlattr *nest;
struct tc_action_ops *a_o;
struct tc_action a;
int ret = 0;
struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
struct nlattr *kind = find_dump_kind(cb->nlh);
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;
}
memset(&a, 0, sizeof(struct tc_action));
a.ops = a_o;
if (a_o->walk == NULL) {
WARN(1, "tc_dump_action: %s !capable of dumping table\n",
a_o->kind);
goto nla_put_failure;
}
nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
cb->nlh->nlmsg_type, sizeof(*t));
t = NLMSG_DATA(nlh);
t->tca_family = AF_UNSPEC;
t->tca__pad1 = 0;
t->tca__pad2 = 0;
nest = nla_nest_start(skb, TCA_ACT_TAB);
if (nest == NULL)
goto nla_put_failure;
ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
if (ret < 0)
goto nla_put_failure;
if (ret > 0) {
nla_nest_end(skb, nest);
ret = skb->len;
} else
nla_nest_cancel(skb, nest);
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
if (NETLINK_CB(cb->skb).pid && ret)
nlh->nlmsg_flags |= NLM_F_MULTI;
module_put(a_o->owner);
return skb->len;
nla_put_failure:
nlmsg_failure:
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);
rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
return 0;
}
subsys_initcall(tc_action_init);