swh:1:snp:173f8deb0c56c557784b4fd217e7608ac6197844
Tip revision: 62fb9874f5da54fdb243003b386128037319b219 authored by Linus Torvalds on 27 June 2021, 22:21:11 UTC
Linux 5.13
Linux 5.13
Tip revision: 62fb987
ip_set_list_set.c
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (C) 2008-2013 Jozsef Kadlecsik <kadlec@netfilter.org> */
/* Kernel module implementing an IP set type: the list:set type */
#include <linux/module.h>
#include <linux/ip.h>
#include <linux/rculist.h>
#include <linux/skbuff.h>
#include <linux/errno.h>
#include <linux/netfilter/ipset/ip_set.h>
#include <linux/netfilter/ipset/ip_set_list.h>
#define IPSET_TYPE_REV_MIN 0
/* 1 Counters support added */
/* 2 Comments support added */
#define IPSET_TYPE_REV_MAX 3 /* skbinfo support added */
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@netfilter.org>");
IP_SET_MODULE_DESC("list:set", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
MODULE_ALIAS("ip_set_list:set");
/* Member elements */
struct set_elem {
struct rcu_head rcu;
struct list_head list;
struct ip_set *set; /* Sigh, in order to cleanup reference */
ip_set_id_t id;
} __aligned(__alignof__(u64));
struct set_adt_elem {
ip_set_id_t id;
ip_set_id_t refid;
int before;
};
/* Type structure */
struct list_set {
u32 size; /* size of set list array */
struct timer_list gc; /* garbage collection */
struct ip_set *set; /* attached to this ip_set */
struct net *net; /* namespace */
struct list_head members; /* the set members */
};
static int
list_set_ktest(struct ip_set *set, const struct sk_buff *skb,
const struct xt_action_param *par,
struct ip_set_adt_opt *opt, const struct ip_set_ext *ext)
{
struct list_set *map = set->data;
struct ip_set_ext *mext = &opt->ext;
struct set_elem *e;
u32 flags = 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;
list_for_each_entry_rcu(e, &map->members, list) {
ret = ip_set_test(e->id, skb, par, opt);
if (ret <= 0)
continue;
if (ip_set_match_extensions(set, ext, mext, flags, e))
return 1;
}
return 0;
}
static int
list_set_kadd(struct ip_set *set, const struct sk_buff *skb,
const struct xt_action_param *par,
struct ip_set_adt_opt *opt, const struct ip_set_ext *ext)
{
struct list_set *map = set->data;
struct set_elem *e;
int ret;
list_for_each_entry(e, &map->members, list) {
if (SET_WITH_TIMEOUT(set) &&
ip_set_timeout_expired(ext_timeout(e, set)))
continue;
ret = ip_set_add(e->id, skb, par, opt);
if (ret == 0)
return ret;
}
return 0;
}
static int
list_set_kdel(struct ip_set *set, const struct sk_buff *skb,
const struct xt_action_param *par,
struct ip_set_adt_opt *opt, const struct ip_set_ext *ext)
{
struct list_set *map = set->data;
struct set_elem *e;
int ret;
list_for_each_entry(e, &map->members, list) {
if (SET_WITH_TIMEOUT(set) &&
ip_set_timeout_expired(ext_timeout(e, set)))
continue;
ret = ip_set_del(e->id, skb, par, opt);
if (ret == 0)
return ret;
}
return 0;
}
static int
list_set_kadt(struct ip_set *set, const struct sk_buff *skb,
const struct xt_action_param *par,
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:
ret = list_set_ktest(set, skb, par, opt, &ext);
break;
case IPSET_ADD:
ret = list_set_kadd(set, skb, par, opt, &ext);
break;
case IPSET_DEL:
ret = list_set_kdel(set, skb, par, opt, &ext);
break;
default:
break;
}
rcu_read_unlock();
return ret;
}
/* Userspace interfaces: we are protected by the nfnl mutex */
static void
__list_set_del_rcu(struct rcu_head * rcu)
{
struct set_elem *e = container_of(rcu, struct set_elem, rcu);
struct ip_set *set = e->set;
ip_set_ext_destroy(set, e);
kfree(e);
}
static void
list_set_del(struct ip_set *set, struct set_elem *e)
{
struct list_set *map = set->data;
set->elements--;
list_del_rcu(&e->list);
ip_set_put_byindex(map->net, e->id);
call_rcu(&e->rcu, __list_set_del_rcu);
}
static void
list_set_replace(struct ip_set *set, struct set_elem *e, struct set_elem *old)
{
struct list_set *map = set->data;
list_replace_rcu(&old->list, &e->list);
ip_set_put_byindex(map->net, old->id);
call_rcu(&old->rcu, __list_set_del_rcu);
}
static void
set_cleanup_entries(struct ip_set *set)
{
struct list_set *map = set->data;
struct set_elem *e, *n;
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
list_set_utest(struct ip_set *set, void *value, const struct ip_set_ext *ext,
struct ip_set_ext *mext, u32 flags)
{
struct list_set *map = set->data;
struct set_adt_elem *d = value;
struct set_elem *e, *next, *prev = NULL;
int ret;
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) {
prev = e;
continue;
}
if (d->before == 0) {
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(set, 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,
struct ip_set_ext *mext, u32 flags)
{
struct list_set *map = set->data;
struct set_adt_elem *d = value;
struct set_elem *e, *n, *prev, *next;
bool flag_exist = flags & IPSET_FLAG_EXIST;
/* 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;
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;
}
/* If before/after is used on an empty set */
if ((d->before > 0 && !next) ||
(d->before < 0 && !prev))
return -IPSET_ERR_REF_EXIST;
/* Re-add already existing element */
if (n) {
if (!flag_exist)
return -IPSET_ERR_EXIST;
/* Update extensions */
ip_set_ext_destroy(set, n);
list_set_init_extensions(set, ext, n);
/* Set is already added to the list */
ip_set_put_byindex(map->net, d->id);
return 0;
}
/* 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;
e = kzalloc(set->dsize, GFP_ATOMIC);
if (!e)
return -ENOMEM;
e->id = d->id;
e->set = set;
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);
set->elements++;
return 0;
}
static int
list_set_udel(struct ip_set *set, void *value, const struct ip_set_ext *ext,
struct ip_set_ext *mext, u32 flags)
{
struct list_set *map = set->data;
struct set_adt_elem *d = value;
struct set_elem *e, *next, *prev = NULL;
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) {
prev = e;
continue;
}
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;
} else if (d->before < 0) {
if (!prev || prev->id != d->refid)
return -IPSET_ERR_REF_EXIST;
}
list_set_del(set, e);
return 0;
}
return d->before != 0 ? -IPSET_ERR_REF_EXIST : -IPSET_ERR_EXIST;
}
static int
list_set_uadt(struct ip_set *set, struct nlattr *tb[],
enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
{
struct list_set *map = set->data;
ipset_adtfn adtfn = set->variant->adt[adt];
struct set_adt_elem e = { .refid = IPSET_INVALID_ID };
struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
struct ip_set *s;
int ret = 0;
if (tb[IPSET_ATTR_LINENO])
*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
if (unlikely(!tb[IPSET_ATTR_NAME] ||
!ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
return -IPSET_ERR_PROTOCOL;
ret = ip_set_get_extensions(set, tb, &ext);
if (ret)
return ret;
e.id = ip_set_get_byname(map->net, nla_data(tb[IPSET_ATTR_NAME]), &s);
if (e.id == IPSET_INVALID_ID)
return -IPSET_ERR_NAME;
/* "Loop detection" */
if (s->type->features & IPSET_TYPE_NAME) {
ret = -IPSET_ERR_LOOP;
goto finish;
}
if (tb[IPSET_ATTR_CADT_FLAGS]) {
u32 f = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
e.before = f & IPSET_FLAG_BEFORE;
}
if (e.before && !tb[IPSET_ATTR_NAMEREF]) {
ret = -IPSET_ERR_BEFORE;
goto finish;
}
if (tb[IPSET_ATTR_NAMEREF]) {
e.refid = ip_set_get_byname(map->net,
nla_data(tb[IPSET_ATTR_NAMEREF]),
&s);
if (e.refid == IPSET_INVALID_ID) {
ret = -IPSET_ERR_NAMEREF;
goto finish;
}
if (!e.before)
e.before = -1;
}
if (adt != IPSET_TEST && SET_WITH_TIMEOUT(set))
set_cleanup_entries(set);
ret = adtfn(set, &e, &ext, &ext, flags);
finish:
if (e.refid != IPSET_INVALID_ID)
ip_set_put_byindex(map->net, e.refid);
if (adt != IPSET_ADD || ret)
ip_set_put_byindex(map->net, e.id);
return ip_set_eexist(ret, flags) ? 0 : ret;
}
static void
list_set_flush(struct ip_set *set)
{
struct list_set *map = set->data;
struct set_elem *e, *n;
list_for_each_entry_safe(e, n, &map->members, list)
list_set_del(set, e);
set->elements = 0;
set->ext_size = 0;
}
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_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;
}
/* Calculate the actual memory size of the set data */
static size_t
list_set_memsize(const struct list_set *map, size_t dsize)
{
struct set_elem *e;
u32 n = 0;
rcu_read_lock();
list_for_each_entry_rcu(e, &map->members, list)
n++;
rcu_read_unlock();
return (sizeof(*map) + n * dsize);
}
static int
list_set_head(struct ip_set *set, struct sk_buff *skb)
{
const struct list_set *map = set->data;
struct nlattr *nested;
size_t memsize = list_set_memsize(map, set->dsize) + set->ext_size;
nested = nla_nest_start(skb, IPSET_ATTR_DATA);
if (!nested)
goto nla_put_failure;
if (nla_put_net32(skb, IPSET_ATTR_SIZE, htonl(map->size)) ||
nla_put_net32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref)) ||
nla_put_net32(skb, IPSET_ATTR_MEMSIZE, htonl(memsize)) ||
nla_put_net32(skb, IPSET_ATTR_ELEMENTS, htonl(set->elements)))
goto nla_put_failure;
if (unlikely(ip_set_put_flags(skb, set)))
goto nla_put_failure;
nla_nest_end(skb, nested);
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static int
list_set_list(const struct ip_set *set,
struct sk_buff *skb, struct netlink_callback *cb)
{
const struct list_set *map = set->data;
struct nlattr *atd, *nested;
u32 i = 0, first = cb->args[IPSET_CB_ARG0];
char name[IPSET_MAXNAMELEN];
struct set_elem *e;
int ret = 0;
atd = nla_nest_start(skb, IPSET_ATTR_ADT);
if (!atd)
return -EMSGSIZE;
rcu_read_lock();
list_for_each_entry_rcu(e, &map->members, list) {
if (i < first ||
(SET_WITH_TIMEOUT(set) &&
ip_set_timeout_expired(ext_timeout(e, set)))) {
i++;
continue;
}
nested = nla_nest_start(skb, IPSET_ATTR_DATA);
if (!nested)
goto nla_put_failure;
ip_set_name_byindex(map->net, e->id, name);
if (nla_put_string(skb, IPSET_ATTR_NAME, name))
goto nla_put_failure;
if (ip_set_put_extensions(skb, set, e, true))
goto nla_put_failure;
nla_nest_end(skb, nested);
i++;
}
nla_nest_end(skb, atd);
/* Set listing finished */
cb->args[IPSET_CB_ARG0] = 0;
goto out;
nla_put_failure:
nla_nest_cancel(skb, nested);
if (unlikely(i == first)) {
nla_nest_cancel(skb, atd);
cb->args[IPSET_CB_ARG0] = 0;
ret = -EMSGSIZE;
} else {
cb->args[IPSET_CB_ARG0] = i;
nla_nest_end(skb, atd);
}
out:
rcu_read_unlock();
return ret;
}
static bool
list_set_same_set(const struct ip_set *a, const struct ip_set *b)
{
const struct list_set *x = a->data;
const struct list_set *y = b->data;
return x->size == y->size &&
a->timeout == b->timeout &&
a->extensions == b->extensions;
}
static const struct ip_set_type_variant set_variant = {
.kadt = list_set_kadt,
.uadt = list_set_uadt,
.adt = {
[IPSET_ADD] = list_set_uadd,
[IPSET_DEL] = list_set_udel,
[IPSET_TEST] = list_set_utest,
},
.destroy = list_set_destroy,
.flush = list_set_flush,
.head = list_set_head,
.list = list_set_list,
.same_set = list_set_same_set,
};
static void
list_set_gc(struct timer_list *t)
{
struct list_set *map = from_timer(map, t, gc);
struct ip_set *set = map->set;
spin_lock_bh(&set->lock);
set_cleanup_entries(set);
spin_unlock_bh(&set->lock);
map->gc.expires = jiffies + IPSET_GC_PERIOD(set->timeout) * HZ;
add_timer(&map->gc);
}
static void
list_set_gc_init(struct ip_set *set, void (*gc)(struct timer_list *t))
{
struct list_set *map = set->data;
timer_setup(&map->gc, gc, 0);
mod_timer(&map->gc, jiffies + IPSET_GC_PERIOD(set->timeout) * HZ);
}
/* Create list:set type of sets */
static bool
init_list_set(struct net *net, struct ip_set *set, u32 size)
{
struct list_set *map;
map = kzalloc(sizeof(*map), GFP_KERNEL);
if (!map)
return false;
map->size = size;
map->net = net;
map->set = set;
INIT_LIST_HEAD(&map->members);
set->data = map;
return true;
}
static int
list_set_create(struct net *net, struct ip_set *set, struct nlattr *tb[],
u32 flags)
{
u32 size = IP_SET_LIST_DEFAULT_SIZE;
if (unlikely(!ip_set_optattr_netorder(tb, IPSET_ATTR_SIZE) ||
!ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT) ||
!ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
return -IPSET_ERR_PROTOCOL;
if (tb[IPSET_ATTR_SIZE])
size = ip_set_get_h32(tb[IPSET_ATTR_SIZE]);
if (size < IP_SET_LIST_MIN_SIZE)
size = IP_SET_LIST_MIN_SIZE;
set->variant = &set_variant;
set->dsize = ip_set_elem_len(set, tb, sizeof(struct set_elem),
__alignof__(struct set_elem));
if (!init_list_set(net, set, size))
return -ENOMEM;
if (tb[IPSET_ATTR_TIMEOUT]) {
set->timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);
list_set_gc_init(set, list_set_gc);
}
return 0;
}
static struct ip_set_type list_set_type __read_mostly = {
.name = "list:set",
.protocol = IPSET_PROTOCOL,
.features = IPSET_TYPE_NAME | IPSET_DUMP_LAST,
.dimension = IPSET_DIM_ONE,
.family = NFPROTO_UNSPEC,
.revision_min = IPSET_TYPE_REV_MIN,
.revision_max = IPSET_TYPE_REV_MAX,
.create = list_set_create,
.create_policy = {
[IPSET_ATTR_SIZE] = { .type = NLA_U32 },
[IPSET_ATTR_TIMEOUT] = { .type = NLA_U32 },
[IPSET_ATTR_CADT_FLAGS] = { .type = NLA_U32 },
},
.adt_policy = {
[IPSET_ATTR_NAME] = { .type = NLA_STRING,
.len = IPSET_MAXNAMELEN },
[IPSET_ATTR_NAMEREF] = { .type = NLA_STRING,
.len = IPSET_MAXNAMELEN },
[IPSET_ATTR_TIMEOUT] = { .type = NLA_U32 },
[IPSET_ATTR_LINENO] = { .type = NLA_U32 },
[IPSET_ATTR_CADT_FLAGS] = { .type = NLA_U32 },
[IPSET_ATTR_BYTES] = { .type = NLA_U64 },
[IPSET_ATTR_PACKETS] = { .type = NLA_U64 },
[IPSET_ATTR_COMMENT] = { .type = NLA_NUL_STRING,
.len = IPSET_MAX_COMMENT_SIZE },
[IPSET_ATTR_SKBMARK] = { .type = NLA_U64 },
[IPSET_ATTR_SKBPRIO] = { .type = NLA_U32 },
[IPSET_ATTR_SKBQUEUE] = { .type = NLA_U16 },
},
.me = THIS_MODULE,
};
static int __init
list_set_init(void)
{
return ip_set_type_register(&list_set_type);
}
static void __exit
list_set_fini(void)
{
rcu_barrier();
ip_set_type_unregister(&list_set_type);
}
module_init(list_set_init);
module_exit(list_set_fini);