netfilter: ipset: Introduce RCU locking in list type

Standard rculist is used.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
This commit is contained in:
Jozsef Kadlecsik 2015-06-13 16:56:02 +02:00
parent 18f84d41d3
commit 00590fdd5b

View File

@ -9,6 +9,7 @@
#include <linux/module.h>
#include <linux/ip.h>
#include <linux/rculist.h>
#include <linux/skbuff.h>
#include <linux/errno.h>
@ -27,6 +28,8 @@ MODULE_ALIAS("ip_set_list:set");
/* Member elements */
struct set_elem {
struct rcu_head rcu;
struct list_head list;
ip_set_id_t id;
};
@ -41,12 +44,9 @@ struct list_set {
u32 size; /* size of set list array */
struct timer_list gc; /* garbage collection */
struct net *net; /* namespace */
struct set_elem members[0]; /* the set members */
struct list_head members; /* the set members */
};
#define list_set_elem(set, map, id) \
(struct set_elem *)((void *)(map)->members + (id) * (set)->dsize)
static int
list_set_ktest(struct ip_set *set, const struct sk_buff *skb,
const struct xt_action_param *par,
@ -54,17 +54,14 @@ list_set_ktest(struct ip_set *set, const struct sk_buff *skb,
{
struct list_set *map = set->data;
struct set_elem *e;
u32 i, cmdflags = opt->cmdflags;
u32 cmdflags = opt->cmdflags;
int ret;
/* Don't lookup sub-counters at all */
opt->cmdflags &= ~IPSET_FLAG_MATCH_COUNTERS;
if (opt->cmdflags & IPSET_FLAG_SKIP_SUBCOUNTER_UPDATE)
opt->cmdflags &= ~IPSET_FLAG_SKIP_COUNTER_UPDATE;
for (i = 0; i < map->size; i++) {
e = list_set_elem(set, map, i);
if (e->id == IPSET_INVALID_ID)
return 0;
list_for_each_entry_rcu(e, &map->members, list) {
if (SET_WITH_TIMEOUT(set) &&
ip_set_timeout_expired(ext_timeout(e, set)))
continue;
@ -91,13 +88,9 @@ list_set_kadd(struct ip_set *set, const struct sk_buff *skb,
{
struct list_set *map = set->data;
struct set_elem *e;
u32 i;
int ret;
for (i = 0; i < map->size; i++) {
e = list_set_elem(set, map, i);
if (e->id == IPSET_INVALID_ID)
return 0;
list_for_each_entry(e, &map->members, list) {
if (SET_WITH_TIMEOUT(set) &&
ip_set_timeout_expired(ext_timeout(e, set)))
continue;
@ -115,13 +108,9 @@ list_set_kdel(struct ip_set *set, const struct sk_buff *skb,
{
struct list_set *map = set->data;
struct set_elem *e;
u32 i;
int ret;
for (i = 0; i < map->size; i++) {
e = list_set_elem(set, map, i);
if (e->id == IPSET_INVALID_ID)
return 0;
list_for_each_entry(e, &map->members, list) {
if (SET_WITH_TIMEOUT(set) &&
ip_set_timeout_expired(ext_timeout(e, set)))
continue;
@ -138,110 +127,65 @@ list_set_kadt(struct ip_set *set, const struct sk_buff *skb,
enum ipset_adt adt, struct ip_set_adt_opt *opt)
{
struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
int ret = -EINVAL;
rcu_read_lock();
switch (adt) {
case IPSET_TEST:
return list_set_ktest(set, skb, par, opt, &ext);
ret = list_set_ktest(set, skb, par, opt, &ext);
break;
case IPSET_ADD:
return list_set_kadd(set, skb, par, opt, &ext);
ret = list_set_kadd(set, skb, par, opt, &ext);
break;
case IPSET_DEL:
return list_set_kdel(set, skb, par, opt, &ext);
ret = list_set_kdel(set, skb, par, opt, &ext);
break;
default:
break;
}
return -EINVAL;
rcu_read_unlock();
return ret;
}
static bool
id_eq(const struct ip_set *set, u32 i, ip_set_id_t id)
{
const struct list_set *map = set->data;
const struct set_elem *e;
/* Userspace interfaces: we are protected by the nfnl mutex */
if (i >= map->size)
return 0;
e = list_set_elem(set, map, i);
return !!(e->id == id &&
!(SET_WITH_TIMEOUT(set) &&
ip_set_timeout_expired(ext_timeout(e, set))));
}
static int
list_set_add(struct ip_set *set, u32 i, struct set_adt_elem *d,
const struct ip_set_ext *ext)
static void
__list_set_del(struct ip_set *set, struct set_elem *e)
{
struct list_set *map = set->data;
struct set_elem *e = list_set_elem(set, map, i);
if (e->id != IPSET_INVALID_ID) {
if (i == map->size - 1) {
/* Last element replaced: e.g. add new,before,last */
ip_set_put_byindex(map->net, e->id);
ip_set_ext_destroy(set, e);
} else {
struct set_elem *x = list_set_elem(set, map,
map->size - 1);
/* Last element pushed off */
if (x->id != IPSET_INVALID_ID) {
ip_set_put_byindex(map->net, x->id);
ip_set_ext_destroy(set, x);
}
memmove(list_set_elem(set, map, i + 1), e,
set->dsize * (map->size - (i + 1)));
/* Extensions must be initialized to zero */
memset(e, 0, set->dsize);
}
}
e->id = d->id;
if (SET_WITH_TIMEOUT(set))
ip_set_timeout_set(ext_timeout(e, set), ext->timeout);
if (SET_WITH_COUNTER(set))
ip_set_init_counter(ext_counter(e, set), ext);
if (SET_WITH_COMMENT(set))
ip_set_init_comment(ext_comment(e, set), ext);
if (SET_WITH_SKBINFO(set))
ip_set_init_skbinfo(ext_skbinfo(e, set), ext);
return 0;
}
static int
list_set_del(struct ip_set *set, u32 i)
{
struct list_set *map = set->data;
struct set_elem *e = list_set_elem(set, map, i);
ip_set_put_byindex(map->net, e->id);
/* We may call it, because we don't have a to be destroyed
* extension which is used by the kernel.
*/
ip_set_ext_destroy(set, e);
kfree_rcu(e, rcu);
}
if (i < map->size - 1)
memmove(e, list_set_elem(set, map, i + 1),
set->dsize * (map->size - (i + 1)));
static inline void
list_set_del(struct ip_set *set, struct set_elem *e)
{
list_del_rcu(&e->list);
__list_set_del(set, e);
}
/* Last element */
e = list_set_elem(set, map, map->size - 1);
e->id = IPSET_INVALID_ID;
return 0;
static inline void
list_set_replace(struct ip_set *set, struct set_elem *e, struct set_elem *old)
{
list_replace_rcu(&old->list, &e->list);
__list_set_del(set, old);
}
static void
set_cleanup_entries(struct ip_set *set)
{
struct list_set *map = set->data;
struct set_elem *e;
u32 i = 0;
struct set_elem *e, *n;
while (i < map->size) {
e = list_set_elem(set, map, i);
if (e->id != IPSET_INVALID_ID &&
ip_set_timeout_expired(ext_timeout(e, set)))
list_set_del(set, i);
/* Check element moved to position i in next loop */
else
i++;
}
list_for_each_entry_safe(e, n, &map->members, list)
if (ip_set_timeout_expired(ext_timeout(e, set)))
list_set_del(set, e);
}
static int
@ -250,31 +194,45 @@ list_set_utest(struct ip_set *set, void *value, const struct ip_set_ext *ext,
{
struct list_set *map = set->data;
struct set_adt_elem *d = value;
struct set_elem *e;
u32 i;
struct set_elem *e, *next, *prev = NULL;
int ret;
for (i = 0; i < map->size; i++) {
e = list_set_elem(set, map, i);
if (e->id == IPSET_INVALID_ID)
return 0;
else if (SET_WITH_TIMEOUT(set) &&
ip_set_timeout_expired(ext_timeout(e, set)))
list_for_each_entry(e, &map->members, list) {
if (SET_WITH_TIMEOUT(set) &&
ip_set_timeout_expired(ext_timeout(e, set)))
continue;
else if (e->id != d->id)
else if (e->id != d->id) {
prev = e;
continue;
}
if (d->before == 0)
return 1;
else if (d->before > 0)
ret = id_eq(set, i + 1, d->refid);
else
ret = i > 0 && id_eq(set, i - 1, d->refid);
ret = 1;
else if (d->before > 0) {
next = list_next_entry(e, list);
ret = !list_is_last(&e->list, &map->members) &&
next->id == d->refid;
} else
ret = prev && prev->id == d->refid;
return ret;
}
return 0;
}
static void
list_set_init_extensions(struct ip_set *set, const struct ip_set_ext *ext,
struct set_elem *e)
{
if (SET_WITH_COUNTER(set))
ip_set_init_counter(ext_counter(e, set), ext);
if (SET_WITH_COMMENT(set))
ip_set_init_comment(ext_comment(e, set), ext);
if (SET_WITH_SKBINFO(set))
ip_set_init_skbinfo(ext_skbinfo(e, set), ext);
/* Update timeout last */
if (SET_WITH_TIMEOUT(set))
ip_set_timeout_set(ext_timeout(e, set), ext->timeout);
}
static int
list_set_uadd(struct ip_set *set, void *value, const struct ip_set_ext *ext,
@ -282,60 +240,78 @@ list_set_uadd(struct ip_set *set, void *value, const struct ip_set_ext *ext,
{
struct list_set *map = set->data;
struct set_adt_elem *d = value;
struct set_elem *e;
struct set_elem *e, *n, *prev, *next;
bool flag_exist = flags & IPSET_FLAG_EXIST;
u32 i, ret = 0;
if (SET_WITH_TIMEOUT(set))
set_cleanup_entries(set);
/* Check already added element */
for (i = 0; i < map->size; i++) {
e = list_set_elem(set, map, i);
if (e->id == IPSET_INVALID_ID)
goto insert;
else if (e->id != d->id)
/* Find where to add the new entry */
n = prev = next = NULL;
list_for_each_entry(e, &map->members, list) {
if (SET_WITH_TIMEOUT(set) &&
ip_set_timeout_expired(ext_timeout(e, set)))
continue;
if ((d->before > 1 && !id_eq(set, i + 1, d->refid)) ||
(d->before < 0 &&
(i == 0 || !id_eq(set, i - 1, d->refid))))
/* Before/after doesn't match */
else if (d->id == e->id)
n = e;
else if (d->before == 0 || e->id != d->refid)
continue;
else if (d->before > 0)
next = e;
else
prev = e;
}
/* Re-add already existing element */
if (n) {
if ((d->before > 0 && !next) ||
(d->before < 0 && !prev))
return -IPSET_ERR_REF_EXIST;
if (!flag_exist)
/* Can't re-add */
return -IPSET_ERR_EXIST;
/* Update extensions */
ip_set_ext_destroy(set, e);
ip_set_ext_destroy(set, n);
list_set_init_extensions(set, ext, n);
if (SET_WITH_TIMEOUT(set))
ip_set_timeout_set(ext_timeout(e, set), ext->timeout);
if (SET_WITH_COUNTER(set))
ip_set_init_counter(ext_counter(e, set), ext);
if (SET_WITH_COMMENT(set))
ip_set_init_comment(ext_comment(e, set), ext);
if (SET_WITH_SKBINFO(set))
ip_set_init_skbinfo(ext_skbinfo(e, set), ext);
/* Set is already added to the list */
ip_set_put_byindex(map->net, d->id);
return 0;
}
insert:
ret = -IPSET_ERR_LIST_FULL;
for (i = 0; i < map->size && ret == -IPSET_ERR_LIST_FULL; i++) {
e = list_set_elem(set, map, i);
if (e->id == IPSET_INVALID_ID)
ret = d->before != 0 ? -IPSET_ERR_REF_EXIST
: list_set_add(set, i, d, ext);
else if (e->id != d->refid)
continue;
else if (d->before > 0)
ret = list_set_add(set, i, d, ext);
else if (i + 1 < map->size)
ret = list_set_add(set, i + 1, d, ext);
/* Add new entry */
if (d->before == 0) {
/* Append */
n = list_empty(&map->members) ? NULL :
list_last_entry(&map->members, struct set_elem, list);
} else if (d->before > 0) {
/* Insert after next element */
if (!list_is_last(&next->list, &map->members))
n = list_next_entry(next, list);
} else {
/* Insert before prev element */
if (prev->list.prev != &map->members)
n = list_prev_entry(prev, list);
}
/* Can we replace a timed out entry? */
if (n &&
!(SET_WITH_TIMEOUT(set) &&
ip_set_timeout_expired(ext_timeout(n, set))))
n = NULL;
return ret;
e = kzalloc(set->dsize, GFP_KERNEL);
if (!e)
return -ENOMEM;
e->id = d->id;
INIT_LIST_HEAD(&e->list);
list_set_init_extensions(set, ext, e);
if (n)
list_set_replace(set, e, n);
else if (next)
list_add_tail_rcu(&e->list, &next->list);
else if (prev)
list_add_rcu(&e->list, &prev->list);
else
list_add_tail_rcu(&e->list, &map->members);
return 0;
}
static int
@ -344,32 +320,30 @@ list_set_udel(struct ip_set *set, void *value, const struct ip_set_ext *ext,
{
struct list_set *map = set->data;
struct set_adt_elem *d = value;
struct set_elem *e;
u32 i;
struct set_elem *e, *next, *prev = NULL;
for (i = 0; i < map->size; i++) {
e = list_set_elem(set, map, i);
if (e->id == IPSET_INVALID_ID)
return d->before != 0 ? -IPSET_ERR_REF_EXIST
: -IPSET_ERR_EXIST;
else if (SET_WITH_TIMEOUT(set) &&
ip_set_timeout_expired(ext_timeout(e, set)))
list_for_each_entry(e, &map->members, list) {
if (SET_WITH_TIMEOUT(set) &&
ip_set_timeout_expired(ext_timeout(e, set)))
continue;
else if (e->id != d->id)
else if (e->id != d->id) {
prev = e;
continue;
}
if (d->before == 0)
return list_set_del(set, i);
else if (d->before > 0) {
if (!id_eq(set, i + 1, d->refid))
if (d->before > 0) {
next = list_next_entry(e, list);
if (list_is_last(&e->list, &map->members) ||
next->id != d->refid)
return -IPSET_ERR_REF_EXIST;
return list_set_del(set, i);
} else if (i == 0 || !id_eq(set, i - 1, d->refid))
return -IPSET_ERR_REF_EXIST;
else
return list_set_del(set, i);
} else if (d->before < 0) {
if (!prev || prev->id != d->refid)
return -IPSET_ERR_REF_EXIST;
}
list_set_del(set, e);
return 0;
}
return -IPSET_ERR_EXIST;
return d->before != 0 ? -IPSET_ERR_REF_EXIST : -IPSET_ERR_EXIST;
}
static int
@ -404,6 +378,7 @@ list_set_uadt(struct ip_set *set, struct nlattr *tb[],
if (tb[IPSET_ATTR_CADT_FLAGS]) {
u32 f = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
e.before = f & IPSET_FLAG_BEFORE;
}
@ -441,27 +416,26 @@ static void
list_set_flush(struct ip_set *set)
{
struct list_set *map = set->data;
struct set_elem *e;
u32 i;
struct set_elem *e, *n;
for (i = 0; i < map->size; i++) {
e = list_set_elem(set, map, i);
if (e->id != IPSET_INVALID_ID) {
ip_set_put_byindex(map->net, e->id);
ip_set_ext_destroy(set, e);
e->id = IPSET_INVALID_ID;
}
}
list_for_each_entry_safe(e, n, &map->members, list)
list_set_del(set, e);
}
static void
list_set_destroy(struct ip_set *set)
{
struct list_set *map = set->data;
struct set_elem *e, *n;
if (SET_WITH_TIMEOUT(set))
del_timer_sync(&map->gc);
list_set_flush(set);
list_for_each_entry_safe(e, n, &map->members, list) {
list_del(&e->list);
ip_set_put_byindex(map->net, e->id);
ip_set_ext_destroy(set, e);
kfree(e);
}
kfree(map);
set->data = NULL;
@ -472,6 +446,11 @@ list_set_head(struct ip_set *set, struct sk_buff *skb)
{
const struct list_set *map = set->data;
struct nlattr *nested;
struct set_elem *e;
u32 n = 0;
list_for_each_entry(e, &map->members, list)
n++;
nested = ipset_nest_start(skb, IPSET_ATTR_DATA);
if (!nested)
@ -479,7 +458,7 @@ list_set_head(struct ip_set *set, struct sk_buff *skb)
if (nla_put_net32(skb, IPSET_ATTR_SIZE, htonl(map->size)) ||
nla_put_net32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref - 1)) ||
nla_put_net32(skb, IPSET_ATTR_MEMSIZE,
htonl(sizeof(*map) + map->size * set->dsize)))
htonl(sizeof(*map) + n * set->dsize)))
goto nla_put_failure;
if (unlikely(ip_set_put_flags(skb, set)))
goto nla_put_failure;
@ -496,18 +475,22 @@ list_set_list(const struct ip_set *set,
{
const struct list_set *map = set->data;
struct nlattr *atd, *nested;
u32 i, first = cb->args[IPSET_CB_ARG0];
const struct set_elem *e;
u32 i = 0, first = cb->args[IPSET_CB_ARG0];
struct set_elem *e;
int ret = 0;
atd = ipset_nest_start(skb, IPSET_ATTR_ADT);
if (!atd)
return -EMSGSIZE;
for (; cb->args[IPSET_CB_ARG0] < map->size;
cb->args[IPSET_CB_ARG0]++) {
i = cb->args[IPSET_CB_ARG0];
e = list_set_elem(set, map, i);
if (e->id == IPSET_INVALID_ID)
goto finish;
list_for_each_entry(e, &map->members, list) {
if (i == first)
break;
i++;
}
rcu_read_lock();
list_for_each_entry_from(e, &map->members, list) {
i++;
if (SET_WITH_TIMEOUT(set) &&
ip_set_timeout_expired(ext_timeout(e, set)))
continue;
@ -515,9 +498,10 @@ list_set_list(const struct ip_set *set,
if (!nested) {
if (i == first) {
nla_nest_cancel(skb, atd);
return -EMSGSIZE;
} else
goto nla_put_failure;
ret = -EMSGSIZE;
goto out;
}
goto nla_put_failure;
}
if (nla_put_string(skb, IPSET_ATTR_NAME,
ip_set_name_byindex(map->net, e->id)))
@ -526,20 +510,23 @@ list_set_list(const struct ip_set *set,
goto nla_put_failure;
ipset_nest_end(skb, nested);
}
finish:
ipset_nest_end(skb, atd);
/* Set listing finished */
cb->args[IPSET_CB_ARG0] = 0;
return 0;
goto out;
nla_put_failure:
nla_nest_cancel(skb, nested);
if (unlikely(i == first)) {
cb->args[IPSET_CB_ARG0] = 0;
return -EMSGSIZE;
ret = -EMSGSIZE;
}
cb->args[IPSET_CB_ARG0] = i - 1;
ipset_nest_end(skb, atd);
return 0;
out:
rcu_read_unlock();
return ret;
}
static bool
@ -574,9 +561,9 @@ list_set_gc(unsigned long ul_set)
struct ip_set *set = (struct ip_set *) ul_set;
struct list_set *map = set->data;
write_lock_bh(&set->lock);
spin_lock_bh(&set->lock);
set_cleanup_entries(set);
write_unlock_bh(&set->lock);
spin_unlock_bh(&set->lock);
map->gc.expires = jiffies + IPSET_GC_PERIOD(set->timeout) * HZ;
add_timer(&map->gc);
@ -600,24 +587,16 @@ static bool
init_list_set(struct net *net, struct ip_set *set, u32 size)
{
struct list_set *map;
struct set_elem *e;
u32 i;
map = kzalloc(sizeof(*map) +
min_t(u32, size, IP_SET_LIST_MAX_SIZE) * set->dsize,
GFP_KERNEL);
map = kzalloc(sizeof(*map), GFP_KERNEL);
if (!map)
return false;
map->size = size;
map->net = net;
INIT_LIST_HEAD(&map->members);
set->data = map;
for (i = 0; i < size; i++) {
e = list_set_elem(set, map, i);
e->id = IPSET_INVALID_ID;
}
return true;
}
@ -690,6 +669,7 @@ list_set_init(void)
static void __exit
list_set_fini(void)
{
rcu_barrier();
ip_set_type_unregister(&list_set_type);
}