1 /* SPDX-License-Identifier: GPL-2.0 */
2 #include <linux/kernel.h>
3 #include <linux/init.h>
4 #include <linux/module.h>
5 #include <linux/spinlock.h>
6 #include <linux/netlink.h>
7 #include <linux/netfilter.h>
8 #include <linux/netfilter/nf_tables.h>
9 #include <net/netfilter/nf_tables.h>
10 #include <net/netfilter/nf_conntrack.h>
11 #include <net/netfilter/nf_conntrack_count.h>
12 #include <net/netfilter/nf_conntrack_core.h>
13 #include <net/netfilter/nf_conntrack_tuple.h>
14 #include <net/netfilter/nf_conntrack_zones.h>
16 struct nft_connlimit {
17 struct nf_conncount_list *list;
22 static inline void nft_connlimit_do_eval(struct nft_connlimit *priv,
23 struct nft_regs *regs,
24 const struct nft_pktinfo *pkt,
25 const struct nft_set_ext *ext)
27 const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
28 const struct nf_conntrack_tuple *tuple_ptr;
29 struct nf_conntrack_tuple tuple;
30 enum ip_conntrack_info ctinfo;
31 const struct nf_conn *ct;
36 ct = nf_ct_get(pkt->skb, &ctinfo);
38 tuple_ptr = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
39 zone = nf_ct_zone(ct);
40 } else if (!nf_ct_get_tuplepr(pkt->skb, skb_network_offset(pkt->skb),
41 nft_pf(pkt), nft_net(pkt), &tuple)) {
42 regs->verdict.code = NF_DROP;
46 if (nf_conncount_add(nft_net(pkt), priv->list, tuple_ptr, zone)) {
47 regs->verdict.code = NF_DROP;
51 count = priv->list->count;
53 if ((count > priv->limit) ^ priv->invert) {
54 regs->verdict.code = NFT_BREAK;
59 static int nft_connlimit_do_init(const struct nft_ctx *ctx,
60 const struct nlattr * const tb[],
61 struct nft_connlimit *priv)
66 if (!tb[NFTA_CONNLIMIT_COUNT])
69 limit = ntohl(nla_get_be32(tb[NFTA_CONNLIMIT_COUNT]));
71 if (tb[NFTA_CONNLIMIT_FLAGS]) {
72 flags = ntohl(nla_get_be32(tb[NFTA_CONNLIMIT_FLAGS]));
73 if (flags & ~NFT_CONNLIMIT_F_INV)
75 if (flags & NFT_CONNLIMIT_F_INV)
79 priv->list = kmalloc(sizeof(*priv->list), GFP_KERNEL);
83 nf_conncount_list_init(priv->list);
85 priv->invert = invert;
87 return nf_ct_netns_get(ctx->net, ctx->family);
90 static void nft_connlimit_do_destroy(const struct nft_ctx *ctx,
91 struct nft_connlimit *priv)
93 nf_ct_netns_put(ctx->net, ctx->family);
94 nf_conncount_cache_free(priv->list);
98 static int nft_connlimit_do_dump(struct sk_buff *skb,
99 struct nft_connlimit *priv)
101 if (nla_put_be32(skb, NFTA_CONNLIMIT_COUNT, htonl(priv->limit)))
102 goto nla_put_failure;
104 nla_put_be32(skb, NFTA_CONNLIMIT_FLAGS, htonl(NFT_CONNLIMIT_F_INV)))
105 goto nla_put_failure;
113 static inline void nft_connlimit_obj_eval(struct nft_object *obj,
114 struct nft_regs *regs,
115 const struct nft_pktinfo *pkt)
117 struct nft_connlimit *priv = nft_obj_data(obj);
119 nft_connlimit_do_eval(priv, regs, pkt, NULL);
122 static int nft_connlimit_obj_init(const struct nft_ctx *ctx,
123 const struct nlattr * const tb[],
124 struct nft_object *obj)
126 struct nft_connlimit *priv = nft_obj_data(obj);
128 return nft_connlimit_do_init(ctx, tb, priv);
131 static void nft_connlimit_obj_destroy(const struct nft_ctx *ctx,
132 struct nft_object *obj)
134 struct nft_connlimit *priv = nft_obj_data(obj);
136 nft_connlimit_do_destroy(ctx, priv);
139 static int nft_connlimit_obj_dump(struct sk_buff *skb,
140 struct nft_object *obj, bool reset)
142 struct nft_connlimit *priv = nft_obj_data(obj);
144 return nft_connlimit_do_dump(skb, priv);
147 static const struct nla_policy nft_connlimit_policy[NFTA_CONNLIMIT_MAX + 1] = {
148 [NFTA_CONNLIMIT_COUNT] = { .type = NLA_U32 },
149 [NFTA_CONNLIMIT_FLAGS] = { .type = NLA_U32 },
152 static struct nft_object_type nft_connlimit_obj_type;
153 static const struct nft_object_ops nft_connlimit_obj_ops = {
154 .type = &nft_connlimit_obj_type,
155 .size = sizeof(struct nft_connlimit),
156 .eval = nft_connlimit_obj_eval,
157 .init = nft_connlimit_obj_init,
158 .destroy = nft_connlimit_obj_destroy,
159 .dump = nft_connlimit_obj_dump,
162 static struct nft_object_type nft_connlimit_obj_type __read_mostly = {
163 .type = NFT_OBJECT_CONNLIMIT,
164 .ops = &nft_connlimit_obj_ops,
165 .maxattr = NFTA_CONNLIMIT_MAX,
166 .policy = nft_connlimit_policy,
167 .owner = THIS_MODULE,
170 static void nft_connlimit_eval(const struct nft_expr *expr,
171 struct nft_regs *regs,
172 const struct nft_pktinfo *pkt)
174 struct nft_connlimit *priv = nft_expr_priv(expr);
176 nft_connlimit_do_eval(priv, regs, pkt, NULL);
179 static int nft_connlimit_dump(struct sk_buff *skb, const struct nft_expr *expr)
181 struct nft_connlimit *priv = nft_expr_priv(expr);
183 return nft_connlimit_do_dump(skb, priv);
186 static int nft_connlimit_init(const struct nft_ctx *ctx,
187 const struct nft_expr *expr,
188 const struct nlattr * const tb[])
190 struct nft_connlimit *priv = nft_expr_priv(expr);
192 return nft_connlimit_do_init(ctx, tb, priv);
195 static void nft_connlimit_destroy(const struct nft_ctx *ctx,
196 const struct nft_expr *expr)
198 struct nft_connlimit *priv = nft_expr_priv(expr);
200 nft_connlimit_do_destroy(ctx, priv);
203 static int nft_connlimit_clone(struct nft_expr *dst, const struct nft_expr *src)
205 struct nft_connlimit *priv_dst = nft_expr_priv(dst);
206 struct nft_connlimit *priv_src = nft_expr_priv(src);
208 priv_dst->list = kmalloc(sizeof(*priv_dst->list), GFP_ATOMIC);
212 nf_conncount_list_init(priv_dst->list);
213 priv_dst->limit = priv_src->limit;
214 priv_dst->invert = priv_src->invert;
219 static void nft_connlimit_destroy_clone(const struct nft_ctx *ctx,
220 const struct nft_expr *expr)
222 struct nft_connlimit *priv = nft_expr_priv(expr);
224 nf_conncount_cache_free(priv->list);
228 static bool nft_connlimit_gc(struct net *net, const struct nft_expr *expr)
230 struct nft_connlimit *priv = nft_expr_priv(expr);
234 ret = nf_conncount_gc_list(net, priv->list);
240 static struct nft_expr_type nft_connlimit_type;
241 static const struct nft_expr_ops nft_connlimit_ops = {
242 .type = &nft_connlimit_type,
243 .size = NFT_EXPR_SIZE(sizeof(struct nft_connlimit)),
244 .eval = nft_connlimit_eval,
245 .init = nft_connlimit_init,
246 .destroy = nft_connlimit_destroy,
247 .clone = nft_connlimit_clone,
248 .destroy_clone = nft_connlimit_destroy_clone,
249 .dump = nft_connlimit_dump,
250 .gc = nft_connlimit_gc,
253 static struct nft_expr_type nft_connlimit_type __read_mostly = {
255 .ops = &nft_connlimit_ops,
256 .policy = nft_connlimit_policy,
257 .maxattr = NFTA_CONNLIMIT_MAX,
258 .flags = NFT_EXPR_STATEFUL | NFT_EXPR_GC,
259 .owner = THIS_MODULE,
262 static int __init nft_connlimit_module_init(void)
266 err = nft_register_obj(&nft_connlimit_obj_type);
270 err = nft_register_expr(&nft_connlimit_type);
276 nft_unregister_obj(&nft_connlimit_obj_type);
280 static void __exit nft_connlimit_module_exit(void)
282 nft_unregister_expr(&nft_connlimit_type);
283 nft_unregister_obj(&nft_connlimit_obj_type);
286 module_init(nft_connlimit_module_init);
287 module_exit(nft_connlimit_module_exit);
289 MODULE_LICENSE("GPL");
290 MODULE_AUTHOR("Pablo Neira Ayuso");
291 MODULE_ALIAS_NFT_EXPR("connlimit");
292 MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_CONNLIMIT);
293 MODULE_DESCRIPTION("nftables connlimit rule support");