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v5.14.15
  1// SPDX-License-Identifier: GPL-2.0
  2#include <linux/types.h>
  3#include <net/ip.h>
  4#include <net/tcp.h>
  5#include <net/netlink.h>
  6#include <net/netfilter/nf_tables.h>
  7#include <net/netfilter/nf_conntrack.h>
  8#include <net/netfilter/nf_conntrack_synproxy.h>
  9#include <net/netfilter/nf_synproxy.h>
 10#include <linux/netfilter/nf_tables.h>
 11#include <linux/netfilter/nf_synproxy.h>
 12
 13struct nft_synproxy {
 14	struct nf_synproxy_info	info;
 15};
 16
 17static const struct nla_policy nft_synproxy_policy[NFTA_SYNPROXY_MAX + 1] = {
 18	[NFTA_SYNPROXY_MSS]		= { .type = NLA_U16 },
 19	[NFTA_SYNPROXY_WSCALE]		= { .type = NLA_U8 },
 20	[NFTA_SYNPROXY_FLAGS]		= { .type = NLA_U32 },
 21};
 22
 23static void nft_synproxy_tcp_options(struct synproxy_options *opts,
 24				     const struct tcphdr *tcp,
 25				     struct synproxy_net *snet,
 26				     struct nf_synproxy_info *info,
 27				     const struct nft_synproxy *priv)
 28{
 29	this_cpu_inc(snet->stats->syn_received);
 30	if (tcp->ece && tcp->cwr)
 31		opts->options |= NF_SYNPROXY_OPT_ECN;
 32
 33	opts->options &= priv->info.options;
 34	opts->mss_encode = opts->mss_option;
 35	opts->mss_option = info->mss;
 36	if (opts->options & NF_SYNPROXY_OPT_TIMESTAMP)
 37		synproxy_init_timestamp_cookie(info, opts);
 38	else
 39		opts->options &= ~(NF_SYNPROXY_OPT_WSCALE |
 40				   NF_SYNPROXY_OPT_SACK_PERM |
 41				   NF_SYNPROXY_OPT_ECN);
 42}
 43
 44static void nft_synproxy_eval_v4(const struct nft_synproxy *priv,
 45				 struct nft_regs *regs,
 46				 const struct nft_pktinfo *pkt,
 47				 const struct tcphdr *tcp,
 48				 struct tcphdr *_tcph,
 49				 struct synproxy_options *opts)
 50{
 51	struct nf_synproxy_info info = priv->info;
 52	struct net *net = nft_net(pkt);
 53	struct synproxy_net *snet = synproxy_pernet(net);
 54	struct sk_buff *skb = pkt->skb;
 55
 56	if (tcp->syn) {
 57		/* Initial SYN from client */
 58		nft_synproxy_tcp_options(opts, tcp, snet, &info, priv);
 59		synproxy_send_client_synack(net, skb, tcp, opts);
 60		consume_skb(skb);
 61		regs->verdict.code = NF_STOLEN;
 62	} else if (tcp->ack) {
 63		/* ACK from client */
 64		if (synproxy_recv_client_ack(net, skb, tcp, opts,
 65					     ntohl(tcp->seq))) {
 66			consume_skb(skb);
 67			regs->verdict.code = NF_STOLEN;
 68		} else {
 69			regs->verdict.code = NF_DROP;
 70		}
 71	}
 72}
 73
 74#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
 75static void nft_synproxy_eval_v6(const struct nft_synproxy *priv,
 76				 struct nft_regs *regs,
 77				 const struct nft_pktinfo *pkt,
 78				 const struct tcphdr *tcp,
 79				 struct tcphdr *_tcph,
 80				 struct synproxy_options *opts)
 81{
 82	struct nf_synproxy_info info = priv->info;
 83	struct net *net = nft_net(pkt);
 84	struct synproxy_net *snet = synproxy_pernet(net);
 85	struct sk_buff *skb = pkt->skb;
 86
 87	if (tcp->syn) {
 88		/* Initial SYN from client */
 89		nft_synproxy_tcp_options(opts, tcp, snet, &info, priv);
 90		synproxy_send_client_synack_ipv6(net, skb, tcp, opts);
 91		consume_skb(skb);
 92		regs->verdict.code = NF_STOLEN;
 93	} else if (tcp->ack) {
 94		/* ACK from client */
 95		if (synproxy_recv_client_ack_ipv6(net, skb, tcp, opts,
 96						  ntohl(tcp->seq))) {
 97			consume_skb(skb);
 98			regs->verdict.code = NF_STOLEN;
 99		} else {
100			regs->verdict.code = NF_DROP;
101		}
102	}
103}
104#endif /* CONFIG_NF_TABLES_IPV6*/
105
106static void nft_synproxy_do_eval(const struct nft_synproxy *priv,
107				 struct nft_regs *regs,
108				 const struct nft_pktinfo *pkt)
109{
110	struct synproxy_options opts = {};
111	struct sk_buff *skb = pkt->skb;
112	int thoff = nft_thoff(pkt);
113	const struct tcphdr *tcp;
114	struct tcphdr _tcph;
115
116	if (pkt->tprot != IPPROTO_TCP) {
117		regs->verdict.code = NFT_BREAK;
118		return;
119	}
120
121	if (nf_ip_checksum(skb, nft_hook(pkt), thoff, IPPROTO_TCP)) {
122		regs->verdict.code = NF_DROP;
123		return;
124	}
125
126	tcp = skb_header_pointer(skb, thoff,
127				 sizeof(struct tcphdr),
128				 &_tcph);
129	if (!tcp) {
130		regs->verdict.code = NF_DROP;
131		return;
132	}
133
134	if (!synproxy_parse_options(skb, thoff, tcp, &opts)) {
135		regs->verdict.code = NF_DROP;
136		return;
137	}
138
139	switch (skb->protocol) {
140	case htons(ETH_P_IP):
141		nft_synproxy_eval_v4(priv, regs, pkt, tcp, &_tcph, &opts);
142		return;
143#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
144	case htons(ETH_P_IPV6):
145		nft_synproxy_eval_v6(priv, regs, pkt, tcp, &_tcph, &opts);
146		return;
147#endif
148	}
149	regs->verdict.code = NFT_BREAK;
150}
151
152static int nft_synproxy_do_init(const struct nft_ctx *ctx,
153				const struct nlattr * const tb[],
154				struct nft_synproxy *priv)
155{
156	struct synproxy_net *snet = synproxy_pernet(ctx->net);
157	u32 flags;
158	int err;
159
160	if (tb[NFTA_SYNPROXY_MSS])
161		priv->info.mss = ntohs(nla_get_be16(tb[NFTA_SYNPROXY_MSS]));
162	if (tb[NFTA_SYNPROXY_WSCALE])
163		priv->info.wscale = nla_get_u8(tb[NFTA_SYNPROXY_WSCALE]);
164	if (tb[NFTA_SYNPROXY_FLAGS]) {
165		flags = ntohl(nla_get_be32(tb[NFTA_SYNPROXY_FLAGS]));
166		if (flags & ~NF_SYNPROXY_OPT_MASK)
167			return -EOPNOTSUPP;
168		priv->info.options = flags;
169	}
170
171	err = nf_ct_netns_get(ctx->net, ctx->family);
172	if (err)
173		return err;
174
175	switch (ctx->family) {
176	case NFPROTO_IPV4:
177		err = nf_synproxy_ipv4_init(snet, ctx->net);
178		if (err)
179			goto nf_ct_failure;
180		break;
181#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
182	case NFPROTO_IPV6:
183		err = nf_synproxy_ipv6_init(snet, ctx->net);
184		if (err)
185			goto nf_ct_failure;
186		break;
187#endif
188	case NFPROTO_INET:
189	case NFPROTO_BRIDGE:
190		err = nf_synproxy_ipv4_init(snet, ctx->net);
191		if (err)
192			goto nf_ct_failure;
193		err = nf_synproxy_ipv6_init(snet, ctx->net);
194		if (err)
 
195			goto nf_ct_failure;
 
196		break;
197	}
198
199	return 0;
200
201nf_ct_failure:
202	nf_ct_netns_put(ctx->net, ctx->family);
203	return err;
204}
205
206static void nft_synproxy_do_destroy(const struct nft_ctx *ctx)
207{
208	struct synproxy_net *snet = synproxy_pernet(ctx->net);
209
210	switch (ctx->family) {
211	case NFPROTO_IPV4:
212		nf_synproxy_ipv4_fini(snet, ctx->net);
213		break;
214#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
215	case NFPROTO_IPV6:
216		nf_synproxy_ipv6_fini(snet, ctx->net);
217		break;
218#endif
219	case NFPROTO_INET:
220	case NFPROTO_BRIDGE:
221		nf_synproxy_ipv4_fini(snet, ctx->net);
222		nf_synproxy_ipv6_fini(snet, ctx->net);
223		break;
224	}
225	nf_ct_netns_put(ctx->net, ctx->family);
226}
227
228static int nft_synproxy_do_dump(struct sk_buff *skb, struct nft_synproxy *priv)
229{
230	if (nla_put_be16(skb, NFTA_SYNPROXY_MSS, htons(priv->info.mss)) ||
231	    nla_put_u8(skb, NFTA_SYNPROXY_WSCALE, priv->info.wscale) ||
232	    nla_put_be32(skb, NFTA_SYNPROXY_FLAGS, htonl(priv->info.options)))
233		goto nla_put_failure;
234
235	return 0;
236
237nla_put_failure:
238	return -1;
239}
240
241static void nft_synproxy_eval(const struct nft_expr *expr,
242			      struct nft_regs *regs,
243			      const struct nft_pktinfo *pkt)
244{
245	const struct nft_synproxy *priv = nft_expr_priv(expr);
246
247	nft_synproxy_do_eval(priv, regs, pkt);
248}
249
250static int nft_synproxy_validate(const struct nft_ctx *ctx,
251				 const struct nft_expr *expr,
252				 const struct nft_data **data)
253{
 
 
 
 
 
254	return nft_chain_validate_hooks(ctx->chain, (1 << NF_INET_LOCAL_IN) |
255						    (1 << NF_INET_FORWARD));
256}
257
258static int nft_synproxy_init(const struct nft_ctx *ctx,
259			     const struct nft_expr *expr,
260			     const struct nlattr * const tb[])
261{
262	struct nft_synproxy *priv = nft_expr_priv(expr);
263
264	return nft_synproxy_do_init(ctx, tb, priv);
265}
266
267static void nft_synproxy_destroy(const struct nft_ctx *ctx,
268				 const struct nft_expr *expr)
269{
270	nft_synproxy_do_destroy(ctx);
271}
272
273static int nft_synproxy_dump(struct sk_buff *skb, const struct nft_expr *expr)
 
274{
275	struct nft_synproxy *priv = nft_expr_priv(expr);
276
277	return nft_synproxy_do_dump(skb, priv);
278}
279
280static struct nft_expr_type nft_synproxy_type;
281static const struct nft_expr_ops nft_synproxy_ops = {
282	.eval		= nft_synproxy_eval,
283	.size		= NFT_EXPR_SIZE(sizeof(struct nft_synproxy)),
284	.init		= nft_synproxy_init,
285	.destroy	= nft_synproxy_destroy,
286	.dump		= nft_synproxy_dump,
287	.type		= &nft_synproxy_type,
288	.validate	= nft_synproxy_validate,
 
289};
290
291static struct nft_expr_type nft_synproxy_type __read_mostly = {
292	.ops		= &nft_synproxy_ops,
293	.name		= "synproxy",
294	.owner		= THIS_MODULE,
295	.policy		= nft_synproxy_policy,
296	.maxattr	= NFTA_SYNPROXY_MAX,
297};
298
299static int nft_synproxy_obj_init(const struct nft_ctx *ctx,
300				 const struct nlattr * const tb[],
301				 struct nft_object *obj)
302{
303	struct nft_synproxy *priv = nft_obj_data(obj);
304
305	return nft_synproxy_do_init(ctx, tb, priv);
306}
307
308static void nft_synproxy_obj_destroy(const struct nft_ctx *ctx,
309				     struct nft_object *obj)
310{
311	nft_synproxy_do_destroy(ctx);
312}
313
314static int nft_synproxy_obj_dump(struct sk_buff *skb,
315				 struct nft_object *obj, bool reset)
316{
317	struct nft_synproxy *priv = nft_obj_data(obj);
318
319	return nft_synproxy_do_dump(skb, priv);
320}
321
322static void nft_synproxy_obj_eval(struct nft_object *obj,
323				  struct nft_regs *regs,
324				  const struct nft_pktinfo *pkt)
325{
326	const struct nft_synproxy *priv = nft_obj_data(obj);
327
328	nft_synproxy_do_eval(priv, regs, pkt);
329}
330
331static void nft_synproxy_obj_update(struct nft_object *obj,
332				    struct nft_object *newobj)
333{
334	struct nft_synproxy *newpriv = nft_obj_data(newobj);
335	struct nft_synproxy *priv = nft_obj_data(obj);
336
337	priv->info = newpriv->info;
338}
339
340static struct nft_object_type nft_synproxy_obj_type;
341static const struct nft_object_ops nft_synproxy_obj_ops = {
342	.type		= &nft_synproxy_obj_type,
343	.size		= sizeof(struct nft_synproxy),
344	.init		= nft_synproxy_obj_init,
345	.destroy	= nft_synproxy_obj_destroy,
346	.dump		= nft_synproxy_obj_dump,
347	.eval		= nft_synproxy_obj_eval,
348	.update		= nft_synproxy_obj_update,
349};
350
351static struct nft_object_type nft_synproxy_obj_type __read_mostly = {
352	.type		= NFT_OBJECT_SYNPROXY,
353	.ops		= &nft_synproxy_obj_ops,
354	.maxattr	= NFTA_SYNPROXY_MAX,
355	.policy		= nft_synproxy_policy,
356	.owner		= THIS_MODULE,
357};
358
359static int __init nft_synproxy_module_init(void)
360{
361	int err;
362
363	err = nft_register_obj(&nft_synproxy_obj_type);
364	if (err < 0)
365		return err;
366
367	err = nft_register_expr(&nft_synproxy_type);
368	if (err < 0)
369		goto err;
370
371	return 0;
372
373err:
374	nft_unregister_obj(&nft_synproxy_obj_type);
375	return err;
376}
377
378static void __exit nft_synproxy_module_exit(void)
379{
380	nft_unregister_expr(&nft_synproxy_type);
381	nft_unregister_obj(&nft_synproxy_obj_type);
382}
383
384module_init(nft_synproxy_module_init);
385module_exit(nft_synproxy_module_exit);
386
387MODULE_LICENSE("GPL");
388MODULE_AUTHOR("Fernando Fernandez <ffmancera@riseup.net>");
389MODULE_ALIAS_NFT_EXPR("synproxy");
390MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_SYNPROXY);
391MODULE_DESCRIPTION("nftables SYNPROXY expression support");
v6.13.7
  1// SPDX-License-Identifier: GPL-2.0
  2#include <linux/types.h>
  3#include <net/ip.h>
  4#include <net/tcp.h>
  5#include <net/netlink.h>
  6#include <net/netfilter/nf_tables.h>
  7#include <net/netfilter/nf_conntrack.h>
  8#include <net/netfilter/nf_conntrack_synproxy.h>
  9#include <net/netfilter/nf_synproxy.h>
 10#include <linux/netfilter/nf_tables.h>
 11#include <linux/netfilter/nf_synproxy.h>
 12
 13struct nft_synproxy {
 14	struct nf_synproxy_info	info;
 15};
 16
 17static const struct nla_policy nft_synproxy_policy[NFTA_SYNPROXY_MAX + 1] = {
 18	[NFTA_SYNPROXY_MSS]		= { .type = NLA_U16 },
 19	[NFTA_SYNPROXY_WSCALE]		= { .type = NLA_U8 },
 20	[NFTA_SYNPROXY_FLAGS]		= { .type = NLA_U32 },
 21};
 22
 23static void nft_synproxy_tcp_options(struct synproxy_options *opts,
 24				     const struct tcphdr *tcp,
 25				     struct synproxy_net *snet,
 26				     struct nf_synproxy_info *info,
 27				     const struct nft_synproxy *priv)
 28{
 29	this_cpu_inc(snet->stats->syn_received);
 30	if (tcp->ece && tcp->cwr)
 31		opts->options |= NF_SYNPROXY_OPT_ECN;
 32
 33	opts->options &= priv->info.options;
 34	opts->mss_encode = opts->mss_option;
 35	opts->mss_option = info->mss;
 36	if (opts->options & NF_SYNPROXY_OPT_TIMESTAMP)
 37		synproxy_init_timestamp_cookie(info, opts);
 38	else
 39		opts->options &= ~(NF_SYNPROXY_OPT_WSCALE |
 40				   NF_SYNPROXY_OPT_SACK_PERM |
 41				   NF_SYNPROXY_OPT_ECN);
 42}
 43
 44static void nft_synproxy_eval_v4(const struct nft_synproxy *priv,
 45				 struct nft_regs *regs,
 46				 const struct nft_pktinfo *pkt,
 47				 const struct tcphdr *tcp,
 48				 struct tcphdr *_tcph,
 49				 struct synproxy_options *opts)
 50{
 51	struct nf_synproxy_info info = priv->info;
 52	struct net *net = nft_net(pkt);
 53	struct synproxy_net *snet = synproxy_pernet(net);
 54	struct sk_buff *skb = pkt->skb;
 55
 56	if (tcp->syn) {
 57		/* Initial SYN from client */
 58		nft_synproxy_tcp_options(opts, tcp, snet, &info, priv);
 59		synproxy_send_client_synack(net, skb, tcp, opts);
 60		consume_skb(skb);
 61		regs->verdict.code = NF_STOLEN;
 62	} else if (tcp->ack) {
 63		/* ACK from client */
 64		if (synproxy_recv_client_ack(net, skb, tcp, opts,
 65					     ntohl(tcp->seq))) {
 66			consume_skb(skb);
 67			regs->verdict.code = NF_STOLEN;
 68		} else {
 69			regs->verdict.code = NF_DROP;
 70		}
 71	}
 72}
 73
 74#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
 75static void nft_synproxy_eval_v6(const struct nft_synproxy *priv,
 76				 struct nft_regs *regs,
 77				 const struct nft_pktinfo *pkt,
 78				 const struct tcphdr *tcp,
 79				 struct tcphdr *_tcph,
 80				 struct synproxy_options *opts)
 81{
 82	struct nf_synproxy_info info = priv->info;
 83	struct net *net = nft_net(pkt);
 84	struct synproxy_net *snet = synproxy_pernet(net);
 85	struct sk_buff *skb = pkt->skb;
 86
 87	if (tcp->syn) {
 88		/* Initial SYN from client */
 89		nft_synproxy_tcp_options(opts, tcp, snet, &info, priv);
 90		synproxy_send_client_synack_ipv6(net, skb, tcp, opts);
 91		consume_skb(skb);
 92		regs->verdict.code = NF_STOLEN;
 93	} else if (tcp->ack) {
 94		/* ACK from client */
 95		if (synproxy_recv_client_ack_ipv6(net, skb, tcp, opts,
 96						  ntohl(tcp->seq))) {
 97			consume_skb(skb);
 98			regs->verdict.code = NF_STOLEN;
 99		} else {
100			regs->verdict.code = NF_DROP;
101		}
102	}
103}
104#endif /* CONFIG_NF_TABLES_IPV6*/
105
106static void nft_synproxy_do_eval(const struct nft_synproxy *priv,
107				 struct nft_regs *regs,
108				 const struct nft_pktinfo *pkt)
109{
110	struct synproxy_options opts = {};
111	struct sk_buff *skb = pkt->skb;
112	int thoff = nft_thoff(pkt);
113	const struct tcphdr *tcp;
114	struct tcphdr _tcph;
115
116	if (pkt->tprot != IPPROTO_TCP) {
117		regs->verdict.code = NFT_BREAK;
118		return;
119	}
120
121	if (nf_ip_checksum(skb, nft_hook(pkt), thoff, IPPROTO_TCP)) {
122		regs->verdict.code = NF_DROP;
123		return;
124	}
125
126	tcp = skb_header_pointer(skb, thoff,
127				 sizeof(struct tcphdr),
128				 &_tcph);
129	if (!tcp) {
130		regs->verdict.code = NF_DROP;
131		return;
132	}
133
134	if (!synproxy_parse_options(skb, thoff, tcp, &opts)) {
135		regs->verdict.code = NF_DROP;
136		return;
137	}
138
139	switch (skb->protocol) {
140	case htons(ETH_P_IP):
141		nft_synproxy_eval_v4(priv, regs, pkt, tcp, &_tcph, &opts);
142		return;
143#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
144	case htons(ETH_P_IPV6):
145		nft_synproxy_eval_v6(priv, regs, pkt, tcp, &_tcph, &opts);
146		return;
147#endif
148	}
149	regs->verdict.code = NFT_BREAK;
150}
151
152static int nft_synproxy_do_init(const struct nft_ctx *ctx,
153				const struct nlattr * const tb[],
154				struct nft_synproxy *priv)
155{
156	struct synproxy_net *snet = synproxy_pernet(ctx->net);
157	u32 flags;
158	int err;
159
160	if (tb[NFTA_SYNPROXY_MSS])
161		priv->info.mss = ntohs(nla_get_be16(tb[NFTA_SYNPROXY_MSS]));
162	if (tb[NFTA_SYNPROXY_WSCALE])
163		priv->info.wscale = nla_get_u8(tb[NFTA_SYNPROXY_WSCALE]);
164	if (tb[NFTA_SYNPROXY_FLAGS]) {
165		flags = ntohl(nla_get_be32(tb[NFTA_SYNPROXY_FLAGS]));
166		if (flags & ~NF_SYNPROXY_OPT_MASK)
167			return -EOPNOTSUPP;
168		priv->info.options = flags;
169	}
170
171	err = nf_ct_netns_get(ctx->net, ctx->family);
172	if (err)
173		return err;
174
175	switch (ctx->family) {
176	case NFPROTO_IPV4:
177		err = nf_synproxy_ipv4_init(snet, ctx->net);
178		if (err)
179			goto nf_ct_failure;
180		break;
181#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
182	case NFPROTO_IPV6:
183		err = nf_synproxy_ipv6_init(snet, ctx->net);
184		if (err)
185			goto nf_ct_failure;
186		break;
187#endif
188	case NFPROTO_INET:
 
189		err = nf_synproxy_ipv4_init(snet, ctx->net);
190		if (err)
191			goto nf_ct_failure;
192		err = nf_synproxy_ipv6_init(snet, ctx->net);
193		if (err) {
194			nf_synproxy_ipv4_fini(snet, ctx->net);
195			goto nf_ct_failure;
196		}
197		break;
198	}
199
200	return 0;
201
202nf_ct_failure:
203	nf_ct_netns_put(ctx->net, ctx->family);
204	return err;
205}
206
207static void nft_synproxy_do_destroy(const struct nft_ctx *ctx)
208{
209	struct synproxy_net *snet = synproxy_pernet(ctx->net);
210
211	switch (ctx->family) {
212	case NFPROTO_IPV4:
213		nf_synproxy_ipv4_fini(snet, ctx->net);
214		break;
215#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
216	case NFPROTO_IPV6:
217		nf_synproxy_ipv6_fini(snet, ctx->net);
218		break;
219#endif
220	case NFPROTO_INET:
 
221		nf_synproxy_ipv4_fini(snet, ctx->net);
222		nf_synproxy_ipv6_fini(snet, ctx->net);
223		break;
224	}
225	nf_ct_netns_put(ctx->net, ctx->family);
226}
227
228static int nft_synproxy_do_dump(struct sk_buff *skb, struct nft_synproxy *priv)
229{
230	if (nla_put_be16(skb, NFTA_SYNPROXY_MSS, htons(priv->info.mss)) ||
231	    nla_put_u8(skb, NFTA_SYNPROXY_WSCALE, priv->info.wscale) ||
232	    nla_put_be32(skb, NFTA_SYNPROXY_FLAGS, htonl(priv->info.options)))
233		goto nla_put_failure;
234
235	return 0;
236
237nla_put_failure:
238	return -1;
239}
240
241static void nft_synproxy_eval(const struct nft_expr *expr,
242			      struct nft_regs *regs,
243			      const struct nft_pktinfo *pkt)
244{
245	const struct nft_synproxy *priv = nft_expr_priv(expr);
246
247	nft_synproxy_do_eval(priv, regs, pkt);
248}
249
250static int nft_synproxy_validate(const struct nft_ctx *ctx,
251				 const struct nft_expr *expr)
 
252{
253	if (ctx->family != NFPROTO_IPV4 &&
254	    ctx->family != NFPROTO_IPV6 &&
255	    ctx->family != NFPROTO_INET)
256		return -EOPNOTSUPP;
257
258	return nft_chain_validate_hooks(ctx->chain, (1 << NF_INET_LOCAL_IN) |
259						    (1 << NF_INET_FORWARD));
260}
261
262static int nft_synproxy_init(const struct nft_ctx *ctx,
263			     const struct nft_expr *expr,
264			     const struct nlattr * const tb[])
265{
266	struct nft_synproxy *priv = nft_expr_priv(expr);
267
268	return nft_synproxy_do_init(ctx, tb, priv);
269}
270
271static void nft_synproxy_destroy(const struct nft_ctx *ctx,
272				 const struct nft_expr *expr)
273{
274	nft_synproxy_do_destroy(ctx);
275}
276
277static int nft_synproxy_dump(struct sk_buff *skb,
278			     const struct nft_expr *expr, bool reset)
279{
280	struct nft_synproxy *priv = nft_expr_priv(expr);
281
282	return nft_synproxy_do_dump(skb, priv);
283}
284
285static struct nft_expr_type nft_synproxy_type;
286static const struct nft_expr_ops nft_synproxy_ops = {
287	.eval		= nft_synproxy_eval,
288	.size		= NFT_EXPR_SIZE(sizeof(struct nft_synproxy)),
289	.init		= nft_synproxy_init,
290	.destroy	= nft_synproxy_destroy,
291	.dump		= nft_synproxy_dump,
292	.type		= &nft_synproxy_type,
293	.validate	= nft_synproxy_validate,
294	.reduce		= NFT_REDUCE_READONLY,
295};
296
297static struct nft_expr_type nft_synproxy_type __read_mostly = {
298	.ops		= &nft_synproxy_ops,
299	.name		= "synproxy",
300	.owner		= THIS_MODULE,
301	.policy		= nft_synproxy_policy,
302	.maxattr	= NFTA_SYNPROXY_MAX,
303};
304
305static int nft_synproxy_obj_init(const struct nft_ctx *ctx,
306				 const struct nlattr * const tb[],
307				 struct nft_object *obj)
308{
309	struct nft_synproxy *priv = nft_obj_data(obj);
310
311	return nft_synproxy_do_init(ctx, tb, priv);
312}
313
314static void nft_synproxy_obj_destroy(const struct nft_ctx *ctx,
315				     struct nft_object *obj)
316{
317	nft_synproxy_do_destroy(ctx);
318}
319
320static int nft_synproxy_obj_dump(struct sk_buff *skb,
321				 struct nft_object *obj, bool reset)
322{
323	struct nft_synproxy *priv = nft_obj_data(obj);
324
325	return nft_synproxy_do_dump(skb, priv);
326}
327
328static void nft_synproxy_obj_eval(struct nft_object *obj,
329				  struct nft_regs *regs,
330				  const struct nft_pktinfo *pkt)
331{
332	const struct nft_synproxy *priv = nft_obj_data(obj);
333
334	nft_synproxy_do_eval(priv, regs, pkt);
335}
336
337static void nft_synproxy_obj_update(struct nft_object *obj,
338				    struct nft_object *newobj)
339{
340	struct nft_synproxy *newpriv = nft_obj_data(newobj);
341	struct nft_synproxy *priv = nft_obj_data(obj);
342
343	priv->info = newpriv->info;
344}
345
346static struct nft_object_type nft_synproxy_obj_type;
347static const struct nft_object_ops nft_synproxy_obj_ops = {
348	.type		= &nft_synproxy_obj_type,
349	.size		= sizeof(struct nft_synproxy),
350	.init		= nft_synproxy_obj_init,
351	.destroy	= nft_synproxy_obj_destroy,
352	.dump		= nft_synproxy_obj_dump,
353	.eval		= nft_synproxy_obj_eval,
354	.update		= nft_synproxy_obj_update,
355};
356
357static struct nft_object_type nft_synproxy_obj_type __read_mostly = {
358	.type		= NFT_OBJECT_SYNPROXY,
359	.ops		= &nft_synproxy_obj_ops,
360	.maxattr	= NFTA_SYNPROXY_MAX,
361	.policy		= nft_synproxy_policy,
362	.owner		= THIS_MODULE,
363};
364
365static int __init nft_synproxy_module_init(void)
366{
367	int err;
368
369	err = nft_register_obj(&nft_synproxy_obj_type);
370	if (err < 0)
371		return err;
372
373	err = nft_register_expr(&nft_synproxy_type);
374	if (err < 0)
375		goto err;
376
377	return 0;
378
379err:
380	nft_unregister_obj(&nft_synproxy_obj_type);
381	return err;
382}
383
384static void __exit nft_synproxy_module_exit(void)
385{
386	nft_unregister_expr(&nft_synproxy_type);
387	nft_unregister_obj(&nft_synproxy_obj_type);
388}
389
390module_init(nft_synproxy_module_init);
391module_exit(nft_synproxy_module_exit);
392
393MODULE_LICENSE("GPL");
394MODULE_AUTHOR("Fernando Fernandez <ffmancera@riseup.net>");
395MODULE_ALIAS_NFT_EXPR("synproxy");
396MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_SYNPROXY);
397MODULE_DESCRIPTION("nftables SYNPROXY expression support");