1 /* Copyright (C) 2011-2013 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
2  *
3  * This program is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License version 2 as
5  * published by the Free Software Foundation.
6  */
7 
8 /* Kernel module implementing an IP set type: the hash:net,iface type */
9 
10 #include <linux/jhash.h>
11 #include <linux/module.h>
12 #include <linux/ip.h>
13 #include <linux/skbuff.h>
14 #include <linux/errno.h>
15 #include <linux/random.h>
16 #include <net/ip.h>
17 #include <net/ipv6.h>
18 #include <net/netlink.h>
19 
20 #include <linux/netfilter.h>
21 #include <linux/netfilter_bridge.h>
22 #include <linux/netfilter/ipset/pfxlen.h>
23 #include <linux/netfilter/ipset/ip_set.h>
24 #include <linux/netfilter/ipset/ip_set_hash.h>
25 
26 #define IPSET_TYPE_REV_MIN	0
27 /*				1    nomatch flag support added */
28 /*				2    /0 support added */
29 /*				3    Counters support added */
30 /*				4    Comments support added */
31 /*				5    Forceadd support added */
32 #define IPSET_TYPE_REV_MAX	6 /* skbinfo support added */
33 
34 MODULE_LICENSE("GPL");
35 MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
36 IP_SET_MODULE_DESC("hash:net,iface", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
37 MODULE_ALIAS("ip_set_hash:net,iface");
38 
39 /* Type specific function prefix */
40 #define HTYPE		hash_netiface
41 #define IP_SET_HASH_WITH_NETS
42 #define IP_SET_HASH_WITH_MULTI
43 #define IP_SET_HASH_WITH_NET0
44 
45 #define STRLCPY(a, b)	strlcpy(a, b, IFNAMSIZ)
46 
47 /* IPv4 variant */
48 
49 struct hash_netiface4_elem_hashed {
50 	__be32 ip;
51 	u8 physdev;
52 	u8 cidr;
53 	u8 nomatch;
54 	u8 elem;
55 };
56 
57 /* Member elements */
58 struct hash_netiface4_elem {
59 	__be32 ip;
60 	u8 physdev;
61 	u8 cidr;
62 	u8 nomatch;
63 	u8 elem;
64 	char iface[IFNAMSIZ];
65 };
66 
67 /* Common functions */
68 
69 static inline bool
70 hash_netiface4_data_equal(const struct hash_netiface4_elem *ip1,
71 			  const struct hash_netiface4_elem *ip2,
72 			  u32 *multi)
73 {
74 	return ip1->ip == ip2->ip &&
75 	       ip1->cidr == ip2->cidr &&
76 	       (++*multi) &&
77 	       ip1->physdev == ip2->physdev &&
78 	       strcmp(ip1->iface, ip2->iface) == 0;
79 }
80 
81 static inline int
82 hash_netiface4_do_data_match(const struct hash_netiface4_elem *elem)
83 {
84 	return elem->nomatch ? -ENOTEMPTY : 1;
85 }
86 
87 static inline void
88 hash_netiface4_data_set_flags(struct hash_netiface4_elem *elem, u32 flags)
89 {
90 	elem->nomatch = (flags >> 16) & IPSET_FLAG_NOMATCH;
91 }
92 
93 static inline void
94 hash_netiface4_data_reset_flags(struct hash_netiface4_elem *elem, u8 *flags)
95 {
96 	swap(*flags, elem->nomatch);
97 }
98 
99 static inline void
100 hash_netiface4_data_netmask(struct hash_netiface4_elem *elem, u8 cidr)
101 {
102 	elem->ip &= ip_set_netmask(cidr);
103 	elem->cidr = cidr;
104 }
105 
106 static bool
107 hash_netiface4_data_list(struct sk_buff *skb,
108 			 const struct hash_netiface4_elem *data)
109 {
110 	u32 flags = data->physdev ? IPSET_FLAG_PHYSDEV : 0;
111 
112 	if (data->nomatch)
113 		flags |= IPSET_FLAG_NOMATCH;
114 	if (nla_put_ipaddr4(skb, IPSET_ATTR_IP, data->ip) ||
115 	    nla_put_u8(skb, IPSET_ATTR_CIDR, data->cidr) ||
116 	    nla_put_string(skb, IPSET_ATTR_IFACE, data->iface) ||
117 	    (flags &&
118 	     nla_put_net32(skb, IPSET_ATTR_CADT_FLAGS, htonl(flags))))
119 		goto nla_put_failure;
120 	return false;
121 
122 nla_put_failure:
123 	return true;
124 }
125 
126 static inline void
127 hash_netiface4_data_next(struct hash_netiface4_elem *next,
128 			 const struct hash_netiface4_elem *d)
129 {
130 	next->ip = d->ip;
131 }
132 
133 #define MTYPE		hash_netiface4
134 #define HOST_MASK	32
135 #define HKEY_DATALEN	sizeof(struct hash_netiface4_elem_hashed)
136 #include "ip_set_hash_gen.h"
137 
138 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
139 static const char *get_physindev_name(const struct sk_buff *skb)
140 {
141 	struct net_device *dev = nf_bridge_get_physindev(skb);
142 
143 	return dev ? dev->name : NULL;
144 }
145 
146 static const char *get_physoutdev_name(const struct sk_buff *skb)
147 {
148 	struct net_device *dev = nf_bridge_get_physoutdev(skb);
149 
150 	return dev ? dev->name : NULL;
151 }
152 #endif
153 
154 static int
155 hash_netiface4_kadt(struct ip_set *set, const struct sk_buff *skb,
156 		    const struct xt_action_param *par,
157 		    enum ipset_adt adt, struct ip_set_adt_opt *opt)
158 {
159 	struct hash_netiface4 *h = set->data;
160 	ipset_adtfn adtfn = set->variant->adt[adt];
161 	struct hash_netiface4_elem e = {
162 		.cidr = INIT_CIDR(h->nets[0].cidr[0], HOST_MASK),
163 		.elem = 1,
164 	};
165 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
166 
167 	if (adt == IPSET_TEST)
168 		e.cidr = HOST_MASK;
169 
170 	ip4addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip);
171 	e.ip &= ip_set_netmask(e.cidr);
172 
173 #define IFACE(dir)	(par->state->dir ? par->state->dir->name : "")
174 #define SRCDIR		(opt->flags & IPSET_DIM_TWO_SRC)
175 
176 	if (opt->cmdflags & IPSET_FLAG_PHYSDEV) {
177 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
178 		const char *eiface = SRCDIR ? get_physindev_name(skb) :
179 					      get_physoutdev_name(skb);
180 
181 		if (!eiface)
182 			return -EINVAL;
183 		STRLCPY(e.iface, eiface);
184 		e.physdev = 1;
185 #endif
186 	} else {
187 		STRLCPY(e.iface, SRCDIR ? IFACE(in) : IFACE(out));
188 	}
189 
190 	if (strlen(e.iface) == 0)
191 		return -EINVAL;
192 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
193 }
194 
195 static int
196 hash_netiface4_uadt(struct ip_set *set, struct nlattr *tb[],
197 		    enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
198 {
199 	struct hash_netiface4 *h = set->data;
200 	ipset_adtfn adtfn = set->variant->adt[adt];
201 	struct hash_netiface4_elem e = { .cidr = HOST_MASK, .elem = 1 };
202 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
203 	u32 ip = 0, ip_to = 0, last;
204 	int ret;
205 
206 	if (tb[IPSET_ATTR_LINENO])
207 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
208 
209 	if (unlikely(!tb[IPSET_ATTR_IP] ||
210 		     !tb[IPSET_ATTR_IFACE] ||
211 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
212 		return -IPSET_ERR_PROTOCOL;
213 
214 	ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &ip);
215 	if (ret)
216 		return ret;
217 
218 	ret = ip_set_get_extensions(set, tb, &ext);
219 	if (ret)
220 		return ret;
221 
222 	if (tb[IPSET_ATTR_CIDR]) {
223 		e.cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
224 		if (e.cidr > HOST_MASK)
225 			return -IPSET_ERR_INVALID_CIDR;
226 	}
227 	nla_strlcpy(e.iface, tb[IPSET_ATTR_IFACE], IFNAMSIZ);
228 
229 	if (tb[IPSET_ATTR_CADT_FLAGS]) {
230 		u32 cadt_flags = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
231 
232 		if (cadt_flags & IPSET_FLAG_PHYSDEV)
233 			e.physdev = 1;
234 		if (cadt_flags & IPSET_FLAG_NOMATCH)
235 			flags |= (IPSET_FLAG_NOMATCH << 16);
236 	}
237 	if (adt == IPSET_TEST || !tb[IPSET_ATTR_IP_TO]) {
238 		e.ip = htonl(ip & ip_set_hostmask(e.cidr));
239 		ret = adtfn(set, &e, &ext, &ext, flags);
240 		return ip_set_enomatch(ret, flags, adt, set) ? -ret :
241 		       ip_set_eexist(ret, flags) ? 0 : ret;
242 	}
243 
244 	if (tb[IPSET_ATTR_IP_TO]) {
245 		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &ip_to);
246 		if (ret)
247 			return ret;
248 		if (ip_to < ip)
249 			swap(ip, ip_to);
250 		if (ip + UINT_MAX == ip_to)
251 			return -IPSET_ERR_HASH_RANGE;
252 	} else {
253 		ip_set_mask_from_to(ip, ip_to, e.cidr);
254 	}
255 
256 	if (retried)
257 		ip = ntohl(h->next.ip);
258 	while (!after(ip, ip_to)) {
259 		e.ip = htonl(ip);
260 		last = ip_set_range_to_cidr(ip, ip_to, &e.cidr);
261 		ret = adtfn(set, &e, &ext, &ext, flags);
262 
263 		if (ret && !ip_set_eexist(ret, flags))
264 			return ret;
265 
266 		ret = 0;
267 		ip = last + 1;
268 	}
269 	return ret;
270 }
271 
272 /* IPv6 variant */
273 
274 struct hash_netiface6_elem_hashed {
275 	union nf_inet_addr ip;
276 	u8 physdev;
277 	u8 cidr;
278 	u8 nomatch;
279 	u8 elem;
280 };
281 
282 struct hash_netiface6_elem {
283 	union nf_inet_addr ip;
284 	u8 physdev;
285 	u8 cidr;
286 	u8 nomatch;
287 	u8 elem;
288 	char iface[IFNAMSIZ];
289 };
290 
291 /* Common functions */
292 
293 static inline bool
294 hash_netiface6_data_equal(const struct hash_netiface6_elem *ip1,
295 			  const struct hash_netiface6_elem *ip2,
296 			  u32 *multi)
297 {
298 	return ipv6_addr_equal(&ip1->ip.in6, &ip2->ip.in6) &&
299 	       ip1->cidr == ip2->cidr &&
300 	       (++*multi) &&
301 	       ip1->physdev == ip2->physdev &&
302 	       strcmp(ip1->iface, ip2->iface) == 0;
303 }
304 
305 static inline int
306 hash_netiface6_do_data_match(const struct hash_netiface6_elem *elem)
307 {
308 	return elem->nomatch ? -ENOTEMPTY : 1;
309 }
310 
311 static inline void
312 hash_netiface6_data_set_flags(struct hash_netiface6_elem *elem, u32 flags)
313 {
314 	elem->nomatch = (flags >> 16) & IPSET_FLAG_NOMATCH;
315 }
316 
317 static inline void
318 hash_netiface6_data_reset_flags(struct hash_netiface6_elem *elem, u8 *flags)
319 {
320 	swap(*flags, elem->nomatch);
321 }
322 
323 static inline void
324 hash_netiface6_data_netmask(struct hash_netiface6_elem *elem, u8 cidr)
325 {
326 	ip6_netmask(&elem->ip, cidr);
327 	elem->cidr = cidr;
328 }
329 
330 static bool
331 hash_netiface6_data_list(struct sk_buff *skb,
332 			 const struct hash_netiface6_elem *data)
333 {
334 	u32 flags = data->physdev ? IPSET_FLAG_PHYSDEV : 0;
335 
336 	if (data->nomatch)
337 		flags |= IPSET_FLAG_NOMATCH;
338 	if (nla_put_ipaddr6(skb, IPSET_ATTR_IP, &data->ip.in6) ||
339 	    nla_put_u8(skb, IPSET_ATTR_CIDR, data->cidr) ||
340 	    nla_put_string(skb, IPSET_ATTR_IFACE, data->iface) ||
341 	    (flags &&
342 	     nla_put_net32(skb, IPSET_ATTR_CADT_FLAGS, htonl(flags))))
343 		goto nla_put_failure;
344 	return false;
345 
346 nla_put_failure:
347 	return true;
348 }
349 
350 static inline void
351 hash_netiface6_data_next(struct hash_netiface6_elem *next,
352 			 const struct hash_netiface6_elem *d)
353 {
354 }
355 
356 #undef MTYPE
357 #undef HOST_MASK
358 
359 #define MTYPE		hash_netiface6
360 #define HOST_MASK	128
361 #define HKEY_DATALEN	sizeof(struct hash_netiface6_elem_hashed)
362 #define IP_SET_EMIT_CREATE
363 #include "ip_set_hash_gen.h"
364 
365 static int
366 hash_netiface6_kadt(struct ip_set *set, const struct sk_buff *skb,
367 		    const struct xt_action_param *par,
368 		    enum ipset_adt adt, struct ip_set_adt_opt *opt)
369 {
370 	struct hash_netiface6 *h = set->data;
371 	ipset_adtfn adtfn = set->variant->adt[adt];
372 	struct hash_netiface6_elem e = {
373 		.cidr = INIT_CIDR(h->nets[0].cidr[0], HOST_MASK),
374 		.elem = 1,
375 	};
376 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
377 
378 	if (adt == IPSET_TEST)
379 		e.cidr = HOST_MASK;
380 
381 	ip6addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip.in6);
382 	ip6_netmask(&e.ip, e.cidr);
383 
384 	if (opt->cmdflags & IPSET_FLAG_PHYSDEV) {
385 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
386 		const char *eiface = SRCDIR ? get_physindev_name(skb) :
387 					      get_physoutdev_name(skb);
388 
389 		if (!eiface)
390 			return -EINVAL;
391 		STRLCPY(e.iface, eiface);
392 		e.physdev = 1;
393 #endif
394 	} else {
395 		STRLCPY(e.iface, SRCDIR ? IFACE(in) : IFACE(out));
396 	}
397 
398 	if (strlen(e.iface) == 0)
399 		return -EINVAL;
400 
401 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
402 }
403 
404 static int
405 hash_netiface6_uadt(struct ip_set *set, struct nlattr *tb[],
406 		    enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
407 {
408 	ipset_adtfn adtfn = set->variant->adt[adt];
409 	struct hash_netiface6_elem e = { .cidr = HOST_MASK, .elem = 1 };
410 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
411 	int ret;
412 
413 	if (tb[IPSET_ATTR_LINENO])
414 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
415 
416 	if (unlikely(!tb[IPSET_ATTR_IP] ||
417 		     !tb[IPSET_ATTR_IFACE] ||
418 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
419 		return -IPSET_ERR_PROTOCOL;
420 	if (unlikely(tb[IPSET_ATTR_IP_TO]))
421 		return -IPSET_ERR_HASH_RANGE_UNSUPPORTED;
422 
423 	ret = ip_set_get_ipaddr6(tb[IPSET_ATTR_IP], &e.ip);
424 	if (ret)
425 		return ret;
426 
427 	ret = ip_set_get_extensions(set, tb, &ext);
428 	if (ret)
429 		return ret;
430 
431 	if (tb[IPSET_ATTR_CIDR]) {
432 		e.cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
433 		if (e.cidr > HOST_MASK)
434 			return -IPSET_ERR_INVALID_CIDR;
435 	}
436 
437 	ip6_netmask(&e.ip, e.cidr);
438 
439 	nla_strlcpy(e.iface, tb[IPSET_ATTR_IFACE], IFNAMSIZ);
440 
441 	if (tb[IPSET_ATTR_CADT_FLAGS]) {
442 		u32 cadt_flags = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
443 
444 		if (cadt_flags & IPSET_FLAG_PHYSDEV)
445 			e.physdev = 1;
446 		if (cadt_flags & IPSET_FLAG_NOMATCH)
447 			flags |= (IPSET_FLAG_NOMATCH << 16);
448 	}
449 
450 	ret = adtfn(set, &e, &ext, &ext, flags);
451 
452 	return ip_set_enomatch(ret, flags, adt, set) ? -ret :
453 	       ip_set_eexist(ret, flags) ? 0 : ret;
454 }
455 
456 static struct ip_set_type hash_netiface_type __read_mostly = {
457 	.name		= "hash:net,iface",
458 	.protocol	= IPSET_PROTOCOL,
459 	.features	= IPSET_TYPE_IP | IPSET_TYPE_IFACE |
460 			  IPSET_TYPE_NOMATCH,
461 	.dimension	= IPSET_DIM_TWO,
462 	.family		= NFPROTO_UNSPEC,
463 	.revision_min	= IPSET_TYPE_REV_MIN,
464 	.revision_max	= IPSET_TYPE_REV_MAX,
465 	.create		= hash_netiface_create,
466 	.create_policy	= {
467 		[IPSET_ATTR_HASHSIZE]	= { .type = NLA_U32 },
468 		[IPSET_ATTR_MAXELEM]	= { .type = NLA_U32 },
469 		[IPSET_ATTR_PROBES]	= { .type = NLA_U8 },
470 		[IPSET_ATTR_RESIZE]	= { .type = NLA_U8  },
471 		[IPSET_ATTR_PROTO]	= { .type = NLA_U8 },
472 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
473 		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
474 	},
475 	.adt_policy	= {
476 		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
477 		[IPSET_ATTR_IP_TO]	= { .type = NLA_NESTED },
478 		[IPSET_ATTR_IFACE]	= { .type = NLA_NUL_STRING,
479 					    .len  = IFNAMSIZ - 1 },
480 		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
481 		[IPSET_ATTR_CIDR]	= { .type = NLA_U8 },
482 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
483 		[IPSET_ATTR_LINENO]	= { .type = NLA_U32 },
484 		[IPSET_ATTR_BYTES]	= { .type = NLA_U64 },
485 		[IPSET_ATTR_PACKETS]	= { .type = NLA_U64 },
486 		[IPSET_ATTR_COMMENT]	= { .type = NLA_NUL_STRING,
487 					    .len  = IPSET_MAX_COMMENT_SIZE },
488 		[IPSET_ATTR_SKBMARK]	= { .type = NLA_U64 },
489 		[IPSET_ATTR_SKBPRIO]	= { .type = NLA_U32 },
490 		[IPSET_ATTR_SKBQUEUE]	= { .type = NLA_U16 },
491 	},
492 	.me		= THIS_MODULE,
493 };
494 
495 static int __init
496 hash_netiface_init(void)
497 {
498 	return ip_set_type_register(&hash_netiface_type);
499 }
500 
501 static void __exit
502 hash_netiface_fini(void)
503 {
504 	rcu_barrier();
505 	ip_set_type_unregister(&hash_netiface_type);
506 }
507 
508 module_init(hash_netiface_init);
509 module_exit(hash_netiface_fini);
510