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_netiface *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 (e.cidr == 0)
168 		return -EINVAL;
169 	if (adt == IPSET_TEST)
170 		e.cidr = HOST_MASK;
171 
172 	ip4addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip);
173 	e.ip &= ip_set_netmask(e.cidr);
174 
175 #define IFACE(dir)	(par->dir ? par->dir->name : "")
176 #define SRCDIR		(opt->flags & IPSET_DIM_TWO_SRC)
177 
178 	if (opt->cmdflags & IPSET_FLAG_PHYSDEV) {
179 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
180 		const char *eiface = SRCDIR ? get_physindev_name(skb) :
181 					      get_physoutdev_name(skb);
182 
183 		if (!eiface)
184 			return -EINVAL;
185 		STRLCPY(e.iface, eiface);
186 		e.physdev = 1;
187 #endif
188 	} else {
189 		STRLCPY(e.iface, SRCDIR ? IFACE(in) : IFACE(out));
190 	}
191 
192 	if (strlen(e.iface) == 0)
193 		return -EINVAL;
194 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
195 }
196 
197 static int
198 hash_netiface4_uadt(struct ip_set *set, struct nlattr *tb[],
199 		    enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
200 {
201 	struct hash_netiface *h = set->data;
202 	ipset_adtfn adtfn = set->variant->adt[adt];
203 	struct hash_netiface4_elem e = { .cidr = HOST_MASK, .elem = 1 };
204 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
205 	u32 ip = 0, ip_to = 0, last;
206 	int ret;
207 
208 	if (tb[IPSET_ATTR_LINENO])
209 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
210 
211 	if (unlikely(!tb[IPSET_ATTR_IP] ||
212 		     !tb[IPSET_ATTR_IFACE] ||
213 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
214 		return -IPSET_ERR_PROTOCOL;
215 
216 	ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &ip);
217 	if (ret)
218 		return ret;
219 
220 	ret = ip_set_get_extensions(set, tb, &ext);
221 	if (ret)
222 		return ret;
223 
224 	if (tb[IPSET_ATTR_CIDR]) {
225 		e.cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
226 		if (e.cidr > HOST_MASK)
227 			return -IPSET_ERR_INVALID_CIDR;
228 	}
229 	nla_strlcpy(e.iface, tb[IPSET_ATTR_IFACE], IFNAMSIZ);
230 
231 	if (tb[IPSET_ATTR_CADT_FLAGS]) {
232 		u32 cadt_flags = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
233 
234 		if (cadt_flags & IPSET_FLAG_PHYSDEV)
235 			e.physdev = 1;
236 		if (cadt_flags & IPSET_FLAG_NOMATCH)
237 			flags |= (IPSET_FLAG_NOMATCH << 16);
238 	}
239 	if (adt == IPSET_TEST || !tb[IPSET_ATTR_IP_TO]) {
240 		e.ip = htonl(ip & ip_set_hostmask(e.cidr));
241 		ret = adtfn(set, &e, &ext, &ext, flags);
242 		return ip_set_enomatch(ret, flags, adt, set) ? -ret :
243 		       ip_set_eexist(ret, flags) ? 0 : ret;
244 	}
245 
246 	if (tb[IPSET_ATTR_IP_TO]) {
247 		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &ip_to);
248 		if (ret)
249 			return ret;
250 		if (ip_to < ip)
251 			swap(ip, ip_to);
252 		if (ip + UINT_MAX == ip_to)
253 			return -IPSET_ERR_HASH_RANGE;
254 	} else {
255 		ip_set_mask_from_to(ip, ip_to, e.cidr);
256 	}
257 
258 	if (retried)
259 		ip = ntohl(h->next.ip);
260 	while (!after(ip, ip_to)) {
261 		e.ip = htonl(ip);
262 		last = ip_set_range_to_cidr(ip, ip_to, &e.cidr);
263 		ret = adtfn(set, &e, &ext, &ext, flags);
264 
265 		if (ret && !ip_set_eexist(ret, flags))
266 			return ret;
267 
268 		ret = 0;
269 		ip = last + 1;
270 	}
271 	return ret;
272 }
273 
274 /* IPv6 variant */
275 
276 struct hash_netiface6_elem_hashed {
277 	union nf_inet_addr ip;
278 	u8 physdev;
279 	u8 cidr;
280 	u8 nomatch;
281 	u8 elem;
282 };
283 
284 struct hash_netiface6_elem {
285 	union nf_inet_addr ip;
286 	u8 physdev;
287 	u8 cidr;
288 	u8 nomatch;
289 	u8 elem;
290 	char iface[IFNAMSIZ];
291 };
292 
293 /* Common functions */
294 
295 static inline bool
296 hash_netiface6_data_equal(const struct hash_netiface6_elem *ip1,
297 			  const struct hash_netiface6_elem *ip2,
298 			  u32 *multi)
299 {
300 	return ipv6_addr_equal(&ip1->ip.in6, &ip2->ip.in6) &&
301 	       ip1->cidr == ip2->cidr &&
302 	       (++*multi) &&
303 	       ip1->physdev == ip2->physdev &&
304 	       strcmp(ip1->iface, ip2->iface) == 0;
305 }
306 
307 static inline int
308 hash_netiface6_do_data_match(const struct hash_netiface6_elem *elem)
309 {
310 	return elem->nomatch ? -ENOTEMPTY : 1;
311 }
312 
313 static inline void
314 hash_netiface6_data_set_flags(struct hash_netiface6_elem *elem, u32 flags)
315 {
316 	elem->nomatch = (flags >> 16) & IPSET_FLAG_NOMATCH;
317 }
318 
319 static inline void
320 hash_netiface6_data_reset_flags(struct hash_netiface6_elem *elem, u8 *flags)
321 {
322 	swap(*flags, elem->nomatch);
323 }
324 
325 static inline void
326 hash_netiface6_data_netmask(struct hash_netiface6_elem *elem, u8 cidr)
327 {
328 	ip6_netmask(&elem->ip, cidr);
329 	elem->cidr = cidr;
330 }
331 
332 static bool
333 hash_netiface6_data_list(struct sk_buff *skb,
334 			 const struct hash_netiface6_elem *data)
335 {
336 	u32 flags = data->physdev ? IPSET_FLAG_PHYSDEV : 0;
337 
338 	if (data->nomatch)
339 		flags |= IPSET_FLAG_NOMATCH;
340 	if (nla_put_ipaddr6(skb, IPSET_ATTR_IP, &data->ip.in6) ||
341 	    nla_put_u8(skb, IPSET_ATTR_CIDR, data->cidr) ||
342 	    nla_put_string(skb, IPSET_ATTR_IFACE, data->iface) ||
343 	    (flags &&
344 	     nla_put_net32(skb, IPSET_ATTR_CADT_FLAGS, htonl(flags))))
345 		goto nla_put_failure;
346 	return false;
347 
348 nla_put_failure:
349 	return true;
350 }
351 
352 static inline void
353 hash_netiface6_data_next(struct hash_netiface4_elem *next,
354 			 const struct hash_netiface6_elem *d)
355 {
356 }
357 
358 #undef MTYPE
359 #undef HOST_MASK
360 
361 #define MTYPE		hash_netiface6
362 #define HOST_MASK	128
363 #define HKEY_DATALEN	sizeof(struct hash_netiface6_elem_hashed)
364 #define IP_SET_EMIT_CREATE
365 #include "ip_set_hash_gen.h"
366 
367 static int
368 hash_netiface6_kadt(struct ip_set *set, const struct sk_buff *skb,
369 		    const struct xt_action_param *par,
370 		    enum ipset_adt adt, struct ip_set_adt_opt *opt)
371 {
372 	struct hash_netiface *h = set->data;
373 	ipset_adtfn adtfn = set->variant->adt[adt];
374 	struct hash_netiface6_elem e = {
375 		.cidr = INIT_CIDR(h->nets[0].cidr[0], HOST_MASK),
376 		.elem = 1,
377 	};
378 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
379 
380 	if (e.cidr == 0)
381 		return -EINVAL;
382 	if (adt == IPSET_TEST)
383 		e.cidr = HOST_MASK;
384 
385 	ip6addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip.in6);
386 	ip6_netmask(&e.ip, e.cidr);
387 
388 	if (opt->cmdflags & IPSET_FLAG_PHYSDEV) {
389 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
390 		const char *eiface = SRCDIR ? get_physindev_name(skb) :
391 					      get_physoutdev_name(skb);
392 
393 		if (!eiface)
394 			return -EINVAL;
395 		STRLCPY(e.iface, eiface);
396 		e.physdev = 1;
397 #endif
398 	} else {
399 		STRLCPY(e.iface, SRCDIR ? IFACE(in) : IFACE(out));
400 	}
401 
402 	if (strlen(e.iface) == 0)
403 		return -EINVAL;
404 
405 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
406 }
407 
408 static int
409 hash_netiface6_uadt(struct ip_set *set, struct nlattr *tb[],
410 		    enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
411 {
412 	ipset_adtfn adtfn = set->variant->adt[adt];
413 	struct hash_netiface6_elem e = { .cidr = HOST_MASK, .elem = 1 };
414 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
415 	int ret;
416 
417 	if (tb[IPSET_ATTR_LINENO])
418 		*lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);
419 
420 	if (unlikely(!tb[IPSET_ATTR_IP] ||
421 		     !tb[IPSET_ATTR_IFACE] ||
422 		     !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
423 		return -IPSET_ERR_PROTOCOL;
424 	if (unlikely(tb[IPSET_ATTR_IP_TO]))
425 		return -IPSET_ERR_HASH_RANGE_UNSUPPORTED;
426 
427 	ret = ip_set_get_ipaddr6(tb[IPSET_ATTR_IP], &e.ip);
428 	if (ret)
429 		return ret;
430 
431 	ret = ip_set_get_extensions(set, tb, &ext);
432 	if (ret)
433 		return ret;
434 
435 	if (tb[IPSET_ATTR_CIDR]) {
436 		e.cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
437 		if (e.cidr > HOST_MASK)
438 			return -IPSET_ERR_INVALID_CIDR;
439 	}
440 
441 	ip6_netmask(&e.ip, e.cidr);
442 
443 	nla_strlcpy(e.iface, tb[IPSET_ATTR_IFACE], IFNAMSIZ);
444 
445 	if (tb[IPSET_ATTR_CADT_FLAGS]) {
446 		u32 cadt_flags = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
447 
448 		if (cadt_flags & IPSET_FLAG_PHYSDEV)
449 			e.physdev = 1;
450 		if (cadt_flags & IPSET_FLAG_NOMATCH)
451 			flags |= (IPSET_FLAG_NOMATCH << 16);
452 	}
453 
454 	ret = adtfn(set, &e, &ext, &ext, flags);
455 
456 	return ip_set_enomatch(ret, flags, adt, set) ? -ret :
457 	       ip_set_eexist(ret, flags) ? 0 : ret;
458 }
459 
460 static struct ip_set_type hash_netiface_type __read_mostly = {
461 	.name		= "hash:net,iface",
462 	.protocol	= IPSET_PROTOCOL,
463 	.features	= IPSET_TYPE_IP | IPSET_TYPE_IFACE |
464 			  IPSET_TYPE_NOMATCH,
465 	.dimension	= IPSET_DIM_TWO,
466 	.family		= NFPROTO_UNSPEC,
467 	.revision_min	= IPSET_TYPE_REV_MIN,
468 	.revision_max	= IPSET_TYPE_REV_MAX,
469 	.create		= hash_netiface_create,
470 	.create_policy	= {
471 		[IPSET_ATTR_HASHSIZE]	= { .type = NLA_U32 },
472 		[IPSET_ATTR_MAXELEM]	= { .type = NLA_U32 },
473 		[IPSET_ATTR_PROBES]	= { .type = NLA_U8 },
474 		[IPSET_ATTR_RESIZE]	= { .type = NLA_U8  },
475 		[IPSET_ATTR_PROTO]	= { .type = NLA_U8 },
476 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
477 		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
478 	},
479 	.adt_policy	= {
480 		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },
481 		[IPSET_ATTR_IP_TO]	= { .type = NLA_NESTED },
482 		[IPSET_ATTR_IFACE]	= { .type = NLA_NUL_STRING,
483 					    .len  = IFNAMSIZ - 1 },
484 		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
485 		[IPSET_ATTR_CIDR]	= { .type = NLA_U8 },
486 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
487 		[IPSET_ATTR_LINENO]	= { .type = NLA_U32 },
488 		[IPSET_ATTR_BYTES]	= { .type = NLA_U64 },
489 		[IPSET_ATTR_PACKETS]	= { .type = NLA_U64 },
490 		[IPSET_ATTR_COMMENT]	= { .type = NLA_NUL_STRING,
491 					    .len  = IPSET_MAX_COMMENT_SIZE },
492 		[IPSET_ATTR_SKBMARK]	= { .type = NLA_U64 },
493 		[IPSET_ATTR_SKBPRIO]	= { .type = NLA_U32 },
494 		[IPSET_ATTR_SKBQUEUE]	= { .type = NLA_U16 },
495 	},
496 	.me		= THIS_MODULE,
497 };
498 
499 static int __init
500 hash_netiface_init(void)
501 {
502 	return ip_set_type_register(&hash_netiface_type);
503 }
504 
505 static void __exit
506 hash_netiface_fini(void)
507 {
508 	rcu_barrier();
509 	ip_set_type_unregister(&hash_netiface_type);
510 }
511 
512 module_init(hash_netiface_init);
513 module_exit(hash_netiface_fini);
514