This patch adds a new get operation for sets to look up for an elements
from userspace via netlink interface.
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/net/netfilter/nf_tables.h | 5 ++
net/netfilter/nf_tables_api.c | 184 ++++++++++++++++++++++++++------------
net/netfilter/nft_set_bitmap.c | 18 ++++
net/netfilter/nft_set_hash.c | 39 ++++++++
net/netfilter/nft_set_rbtree.c | 73 +++++++++++++++
5 files changed, 264 insertions(+), 55 deletions(-)
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 0f5b12a4ad09..d011e56cc7a9 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -311,6 +311,7 @@ struct nft_expr;
* @flush: deactivate element in the next generation
* @remove: remove element from set
* @walk: iterate over all set elemeennts
+ * @get: get set elements
* @privsize: function to return size of set private data
* @init: initialize private data of new set instance
* @destroy: destroy private data of set instance
@@ -350,6 +351,10 @@ struct nft_set_ops {
void (*walk)(const struct nft_ctx *ctx,
struct nft_set *set,
struct nft_set_iter *iter);
+ void * (*get)(const struct net *net,
+ const struct nft_set *set,
+ const struct nft_set_elem *elem,
+ unsigned int flags);
unsigned int (*privsize)(const struct nlattr * const nla[],
const struct nft_set_desc *desc);
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 3b4a0739ee39..1d66be0d8ef7 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3586,45 +3586,6 @@ static int nf_tables_dump_set_done(struct netlink_callback *cb)
return 0;
}
-static int nf_tables_getsetelem(struct net *net, struct sock *nlsk,
- struct sk_buff *skb, const struct nlmsghdr *nlh,
- const struct nlattr * const nla[],
- struct netlink_ext_ack *extack)
-{
- u8 genmask = nft_genmask_cur(net);
- const struct nft_set *set;
- struct nft_ctx ctx;
- int err;
-
- err = nft_ctx_init_from_elemattr(&ctx, net, skb, nlh, nla, genmask);
- if (err < 0)
- return err;
-
- set = nf_tables_set_lookup(ctx.table, nla[NFTA_SET_ELEM_LIST_SET],
- genmask);
- if (IS_ERR(set))
- return PTR_ERR(set);
-
- if (nlh->nlmsg_flags & NLM_F_DUMP) {
- struct netlink_dump_control c = {
- .dump = nf_tables_dump_set,
- .done = nf_tables_dump_set_done,
- };
- struct nft_set_dump_ctx *dump_ctx;
-
- dump_ctx = kmalloc(sizeof(*dump_ctx), GFP_KERNEL);
- if (!dump_ctx)
- return -ENOMEM;
-
- dump_ctx->set = set;
- dump_ctx->ctx = ctx;
-
- c.data = dump_ctx;
- return netlink_dump_start(nlsk, skb, nlh, &c);
- }
- return -EOPNOTSUPP;
-}
-
static int nf_tables_fill_setelem_info(struct sk_buff *skb,
const struct nft_ctx *ctx, u32 seq,
u32 portid, int event, u16 flags,
@@ -3670,6 +3631,135 @@ static int nf_tables_fill_setelem_info(struct sk_buff *skb,
return -1;
}
+static int nft_setelem_parse_flags(const struct nft_set *set,
+ const struct nlattr *attr, u32 *flags)
+{
+ if (attr == NULL)
+ return 0;
+
+ *flags = ntohl(nla_get_be32(attr));
+ if (*flags & ~NFT_SET_ELEM_INTERVAL_END)
+ return -EINVAL;
+ if (!(set->flags & NFT_SET_INTERVAL) &&
+ *flags & NFT_SET_ELEM_INTERVAL_END)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int nft_get_set_elem(struct nft_ctx *ctx, struct nft_set *set,
+ const struct nlattr *attr)
+{
+ struct nlattr *nla[NFTA_SET_ELEM_MAX + 1];
+ const struct nft_set_ext *ext;
+ struct nft_data_desc desc;
+ struct nft_set_elem elem;
+ struct sk_buff *skb;
+ uint32_t flags = 0;
+ void *priv;
+ int err;
+
+ err = nla_parse_nested(nla, NFTA_SET_ELEM_MAX, attr,
+ nft_set_elem_policy, NULL);
+ if (err < 0)
+ return err;
+
+ if (!nla[NFTA_SET_ELEM_KEY])
+ return -EINVAL;
+
+ err = nft_setelem_parse_flags(set, nla[NFTA_SET_ELEM_FLAGS], &flags);
+ if (err < 0)
+ return err;
+
+ err = nft_data_init(ctx, &elem.key.val, sizeof(elem.key), &desc,
+ nla[NFTA_SET_ELEM_KEY]);
+ if (err < 0)
+ return err;
+
+ err = -EINVAL;
+ if (desc.type != NFT_DATA_VALUE || desc.len != set->klen)
+ return err;
+
+ priv = set->ops->get(ctx->net, set, &elem, flags);
+ if (IS_ERR(priv))
+ return PTR_ERR(priv);
+
+ elem.priv = priv;
+ ext = nft_set_elem_ext(set, &elem);
+
+ err = -ENOMEM;
+ skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+ if (skb == NULL)
+ goto err1;
+
+ err = nf_tables_fill_setelem_info(skb, ctx, ctx->seq, ctx->portid,
+ NFT_MSG_NEWSETELEM, 0, set, &elem);
+ if (err < 0)
+ goto err2;
+
+ err = nfnetlink_unicast(skb, ctx->net, ctx->portid, MSG_DONTWAIT);
+ /* This avoids a loop in nfnetlink. */
+ if (err < 0)
+ goto err1;
+
+ return 0;
+err2:
+ kfree_skb(skb);
+err1:
+ /* this avoids a loop in nfnetlink. */
+ return err == -EAGAIN ? -ENOBUFS : err;
+}
+
+static int nf_tables_getsetelem(struct net *net, struct sock *nlsk,
+ struct sk_buff *skb, const struct nlmsghdr *nlh,
+ const struct nlattr * const nla[],
+ struct netlink_ext_ack *extack)
+{
+ u8 genmask = nft_genmask_cur(net);
+ struct nft_set *set;
+ struct nlattr *attr;
+ struct nft_ctx ctx;
+ int rem, err = 0;
+
+ err = nft_ctx_init_from_elemattr(&ctx, net, skb, nlh, nla, genmask);
+ if (err < 0)
+ return err;
+
+ set = nf_tables_set_lookup(ctx.table, nla[NFTA_SET_ELEM_LIST_SET],
+ genmask);
+ if (IS_ERR(set))
+ return PTR_ERR(set);
+
+ if (nlh->nlmsg_flags & NLM_F_DUMP) {
+ struct netlink_dump_control c = {
+ .dump = nf_tables_dump_set,
+ .done = nf_tables_dump_set_done,
+ };
+ struct nft_set_dump_ctx *dump_ctx;
+
+ dump_ctx = kmalloc(sizeof(*dump_ctx), GFP_KERNEL);
+ if (!dump_ctx)
+ return -ENOMEM;
+
+ dump_ctx->set = set;
+ dump_ctx->ctx = ctx;
+
+ c.data = dump_ctx;
+ return netlink_dump_start(nlsk, skb, nlh, &c);
+ }
+
+ if (!nla[NFTA_SET_ELEM_LIST_ELEMENTS])
+ return -EINVAL;
+
+ nla_for_each_nested(attr, nla[NFTA_SET_ELEM_LIST_ELEMENTS], rem) {
+ err = nft_get_set_elem(&ctx, set, attr);
+ if (err < 0)
+ break;
+ }
+
+ return err;
+}
+
static void nf_tables_setelem_notify(const struct nft_ctx *ctx,
const struct nft_set *set,
const struct nft_set_elem *elem,
@@ -3770,22 +3860,6 @@ static void nf_tables_set_elem_destroy(const struct nft_set *set, void *elem)
kfree(elem);
}
-static int nft_setelem_parse_flags(const struct nft_set *set,
- const struct nlattr *attr, u32 *flags)
-{
- if (attr == NULL)
- return 0;
-
- *flags = ntohl(nla_get_be32(attr));
- if (*flags & ~NFT_SET_ELEM_INTERVAL_END)
- return -EINVAL;
- if (!(set->flags & NFT_SET_INTERVAL) &&
- *flags & NFT_SET_ELEM_INTERVAL_END)
- return -EINVAL;
-
- return 0;
-}
-
static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
const struct nlattr *attr, u32 nlmsg_flags)
{
diff --git a/net/netfilter/nft_set_bitmap.c b/net/netfilter/nft_set_bitmap.c
index 734989c40579..45fb2752fb63 100644
--- a/net/netfilter/nft_set_bitmap.c
+++ b/net/netfilter/nft_set_bitmap.c
@@ -106,6 +106,23 @@ nft_bitmap_elem_find(const struct nft_set *set, struct nft_bitmap_elem *this,
return NULL;
}
+static void *nft_bitmap_get(const struct net *net, const struct nft_set *set,
+ const struct nft_set_elem *elem, unsigned int flags)
+{
+ const struct nft_bitmap *priv = nft_set_priv(set);
+ u8 genmask = nft_genmask_cur(net);
+ struct nft_bitmap_elem *be;
+
+ list_for_each_entry_rcu(be, &priv->list, head) {
+ if (memcmp(nft_set_ext_key(&be->ext), elem->key.val.data, set->klen) ||
+ !nft_set_elem_active(&be->ext, genmask))
+ continue;
+
+ return be;
+ }
+ return ERR_PTR(-ENOENT);
+}
+
static int nft_bitmap_insert(const struct net *net, const struct nft_set *set,
const struct nft_set_elem *elem,
struct nft_set_ext **ext)
@@ -294,6 +311,7 @@ static struct nft_set_ops nft_bitmap_ops __read_mostly = {
.activate = nft_bitmap_activate,
.lookup = nft_bitmap_lookup,
.walk = nft_bitmap_walk,
+ .get = nft_bitmap_get,
};
static struct nft_set_type nft_bitmap_type __read_mostly = {
diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
index 0fa01d772c5e..155783ee4baa 100644
--- a/net/netfilter/nft_set_hash.c
+++ b/net/netfilter/nft_set_hash.c
@@ -95,6 +95,24 @@ static bool nft_rhash_lookup(const struct net *net, const struct nft_set *set,
return !!he;
}
+static void *nft_rhash_get(const struct net *net, const struct nft_set *set,
+ const struct nft_set_elem *elem, unsigned int flags)
+{
+ struct nft_rhash *priv = nft_set_priv(set);
+ struct nft_rhash_elem *he;
+ struct nft_rhash_cmp_arg arg = {
+ .genmask = nft_genmask_cur(net),
+ .set = set,
+ .key = elem->key.val.data,
+ };
+
+ he = rhashtable_lookup_fast(&priv->ht, &arg, nft_rhash_params);
+ if (he != NULL)
+ return he;
+
+ return ERR_PTR(-ENOENT);
+}
+
static bool nft_rhash_update(struct nft_set *set, const u32 *key,
void *(*new)(struct nft_set *,
const struct nft_expr *,
@@ -409,6 +427,24 @@ static bool nft_hash_lookup(const struct net *net, const struct nft_set *set,
return false;
}
+static void *nft_hash_get(const struct net *net, const struct nft_set *set,
+ const struct nft_set_elem *elem, unsigned int flags)
+{
+ struct nft_hash *priv = nft_set_priv(set);
+ u8 genmask = nft_genmask_cur(net);
+ struct nft_hash_elem *he;
+ u32 hash;
+
+ hash = jhash(elem->key.val.data, set->klen, priv->seed);
+ hash = reciprocal_scale(hash, priv->buckets);
+ hlist_for_each_entry_rcu(he, &priv->table[hash], node) {
+ if (!memcmp(nft_set_ext_key(&he->ext), elem->key.val.data, set->klen) &&
+ nft_set_elem_active(&he->ext, genmask))
+ return he;
+ }
+ return ERR_PTR(-ENOENT);
+}
+
/* nft_hash_select_ops() makes sure key size can be either 2 or 4 bytes . */
static inline u32 nft_hash_key(const u32 *key, u32 klen)
{
@@ -600,6 +636,7 @@ static struct nft_set_ops nft_rhash_ops __read_mostly = {
.lookup = nft_rhash_lookup,
.update = nft_rhash_update,
.walk = nft_rhash_walk,
+ .get = nft_rhash_get,
.features = NFT_SET_MAP | NFT_SET_OBJECT | NFT_SET_TIMEOUT,
};
@@ -617,6 +654,7 @@ static struct nft_set_ops nft_hash_ops __read_mostly = {
.remove = nft_hash_remove,
.lookup = nft_hash_lookup,
.walk = nft_hash_walk,
+ .get = nft_hash_get,
.features = NFT_SET_MAP | NFT_SET_OBJECT,
};
@@ -634,6 +672,7 @@ static struct nft_set_ops nft_hash_fast_ops __read_mostly = {
.remove = nft_hash_remove,
.lookup = nft_hash_lookup_fast,
.walk = nft_hash_walk,
+ .get = nft_hash_get,
.features = NFT_SET_MAP | NFT_SET_OBJECT,
};
diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c
index d83a4ec5900d..e6f08bc5f359 100644
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -113,6 +113,78 @@ static bool nft_rbtree_lookup(const struct net *net, const struct nft_set *set,
return ret;
}
+static bool __nft_rbtree_get(const struct net *net, const struct nft_set *set,
+ const u32 *key, struct nft_rbtree_elem **elem,
+ unsigned int seq, unsigned int flags, u8 genmask)
+{
+ struct nft_rbtree_elem *rbe, *interval = NULL;
+ struct nft_rbtree *priv = nft_set_priv(set);
+ const struct rb_node *parent;
+ const void *this;
+ int d;
+
+ parent = rcu_dereference_raw(priv->root.rb_node);
+ while (parent != NULL) {
+ if (read_seqcount_retry(&priv->count, seq))
+ return false;
+
+ rbe = rb_entry(parent, struct nft_rbtree_elem, node);
+
+ this = nft_set_ext_key(&rbe->ext);
+ d = memcmp(this, key, set->klen);
+ if (d < 0) {
+ parent = rcu_dereference_raw(parent->rb_left);
+ interval = rbe;
+ } else if (d > 0) {
+ parent = rcu_dereference_raw(parent->rb_right);
+ } else {
+ if (!nft_set_elem_active(&rbe->ext, genmask))
+ parent = rcu_dereference_raw(parent->rb_left);
+
+ if (!nft_set_ext_exists(&rbe->ext, NFT_SET_EXT_FLAGS) ||
+ (*nft_set_ext_flags(&rbe->ext) & NFT_SET_ELEM_INTERVAL_END) ==
+ (flags & NFT_SET_ELEM_INTERVAL_END)) {
+ *elem = rbe;
+ return true;
+ }
+ return false;
+ }
+ }
+
+ if (set->flags & NFT_SET_INTERVAL && interval != NULL &&
+ nft_set_elem_active(&interval->ext, genmask) &&
+ !nft_rbtree_interval_end(interval)) {
+ *elem = interval;
+ return true;
+ }
+
+ return false;
+}
+
+static void *nft_rbtree_get(const struct net *net, const struct nft_set *set,
+ const struct nft_set_elem *elem, unsigned int flags)
+{
+ struct nft_rbtree *priv = nft_set_priv(set);
+ unsigned int seq = read_seqcount_begin(&priv->count);
+ struct nft_rbtree_elem *rbe = ERR_PTR(-ENOENT);
+ const u32 *key = (const u32 *)&elem->key.val;
+ u8 genmask = nft_genmask_cur(net);
+ bool ret;
+
+ ret = __nft_rbtree_get(net, set, key, &rbe, seq, flags, genmask);
+ if (ret || !read_seqcount_retry(&priv->count, seq))
+ return rbe;
+
+ read_lock_bh(&priv->lock);
+ seq = read_seqcount_begin(&priv->count);
+ ret = __nft_rbtree_get(net, set, key, &rbe, seq, flags, genmask);
+ if (!ret)
+ rbe = ERR_PTR(-ENOENT);
+ read_unlock_bh(&priv->lock);
+
+ return rbe;
+}
+
static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
struct nft_rbtree_elem *new,
struct nft_set_ext **ext)
@@ -336,6 +408,7 @@ static struct nft_set_ops nft_rbtree_ops __read_mostly = {
.activate = nft_rbtree_activate,
.lookup = nft_rbtree_lookup,
.walk = nft_rbtree_walk,
+ .get = nft_rbtree_get,
.features = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT,
};
--
2.11.0
--
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