1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright (c) 2006 Patrick McHardy <kaber@trash.net> |
4 | * Copyright © CC Computer Consultants GmbH, 2007 - 2008 |
5 | * |
6 | * This is a replacement of the old ipt_recent module, which carried the |
7 | * following copyright notice: |
8 | * |
9 | * Author: Stephen Frost <sfrost@snowman.net> |
10 | * Copyright 2002-2003, Stephen Frost, 2.5.x port by laforge@netfilter.org |
11 | */ |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | #include <linux/init.h> |
14 | #include <linux/ip.h> |
15 | #include <linux/ipv6.h> |
16 | #include <linux/module.h> |
17 | #include <linux/moduleparam.h> |
18 | #include <linux/proc_fs.h> |
19 | #include <linux/seq_file.h> |
20 | #include <linux/string.h> |
21 | #include <linux/ctype.h> |
22 | #include <linux/list.h> |
23 | #include <linux/random.h> |
24 | #include <linux/jhash.h> |
25 | #include <linux/bitops.h> |
26 | #include <linux/skbuff.h> |
27 | #include <linux/inet.h> |
28 | #include <linux/slab.h> |
29 | #include <linux/vmalloc.h> |
30 | #include <net/net_namespace.h> |
31 | #include <net/netns/generic.h> |
32 | |
33 | #include <linux/netfilter/x_tables.h> |
34 | #include <linux/netfilter/xt_recent.h> |
35 | |
36 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>" ); |
37 | MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>" ); |
38 | MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching" ); |
39 | MODULE_LICENSE("GPL" ); |
40 | MODULE_ALIAS("ipt_recent" ); |
41 | MODULE_ALIAS("ip6t_recent" ); |
42 | |
43 | static unsigned int ip_list_tot __read_mostly = 100; |
44 | static unsigned int ip_list_hash_size __read_mostly; |
45 | static unsigned int ip_list_perms __read_mostly = 0644; |
46 | static unsigned int ip_list_uid __read_mostly; |
47 | static unsigned int ip_list_gid __read_mostly; |
48 | module_param(ip_list_tot, uint, 0400); |
49 | module_param(ip_list_hash_size, uint, 0400); |
50 | module_param(ip_list_perms, uint, 0400); |
51 | module_param(ip_list_uid, uint, 0644); |
52 | module_param(ip_list_gid, uint, 0644); |
53 | MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list" ); |
54 | MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs" ); |
55 | MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files" ); |
56 | MODULE_PARM_DESC(ip_list_uid, "default owner of /proc/net/xt_recent/* files" ); |
57 | MODULE_PARM_DESC(ip_list_gid, "default owning group of /proc/net/xt_recent/* files" ); |
58 | |
59 | /* retained for backwards compatibility */ |
60 | static unsigned int ip_pkt_list_tot __read_mostly; |
61 | module_param(ip_pkt_list_tot, uint, 0400); |
62 | MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP address to remember (max. 255)" ); |
63 | |
64 | #define XT_RECENT_MAX_NSTAMPS 256 |
65 | |
66 | struct recent_entry { |
67 | struct list_head list; |
68 | struct list_head lru_list; |
69 | union nf_inet_addr addr; |
70 | u_int16_t family; |
71 | u_int8_t ttl; |
72 | u_int8_t index; |
73 | u_int16_t nstamps; |
74 | unsigned long stamps[]; |
75 | }; |
76 | |
77 | struct recent_table { |
78 | struct list_head list; |
79 | char name[XT_RECENT_NAME_LEN]; |
80 | union nf_inet_addr mask; |
81 | unsigned int refcnt; |
82 | unsigned int entries; |
83 | u8 nstamps_max_mask; |
84 | struct list_head lru_list; |
85 | struct list_head iphash[]; |
86 | }; |
87 | |
88 | struct recent_net { |
89 | struct list_head tables; |
90 | #ifdef CONFIG_PROC_FS |
91 | struct proc_dir_entry *xt_recent; |
92 | #endif |
93 | }; |
94 | |
95 | static unsigned int recent_net_id __read_mostly; |
96 | |
97 | static inline struct recent_net *recent_pernet(struct net *net) |
98 | { |
99 | return net_generic(net, id: recent_net_id); |
100 | } |
101 | |
102 | static DEFINE_SPINLOCK(recent_lock); |
103 | static DEFINE_MUTEX(recent_mutex); |
104 | |
105 | #ifdef CONFIG_PROC_FS |
106 | static const struct proc_ops recent_mt_proc_ops; |
107 | #endif |
108 | |
109 | static u_int32_t hash_rnd __read_mostly; |
110 | |
111 | static inline unsigned int recent_entry_hash4(const union nf_inet_addr *addr) |
112 | { |
113 | return jhash_1word(a: (__force u32)addr->ip, initval: hash_rnd) & |
114 | (ip_list_hash_size - 1); |
115 | } |
116 | |
117 | static inline unsigned int recent_entry_hash6(const union nf_inet_addr *addr) |
118 | { |
119 | return jhash2(k: (u32 *)addr->ip6, ARRAY_SIZE(addr->ip6), initval: hash_rnd) & |
120 | (ip_list_hash_size - 1); |
121 | } |
122 | |
123 | static struct recent_entry * |
124 | recent_entry_lookup(const struct recent_table *table, |
125 | const union nf_inet_addr *addrp, u_int16_t family, |
126 | u_int8_t ttl) |
127 | { |
128 | struct recent_entry *e; |
129 | unsigned int h; |
130 | |
131 | if (family == NFPROTO_IPV4) |
132 | h = recent_entry_hash4(addr: addrp); |
133 | else |
134 | h = recent_entry_hash6(addr: addrp); |
135 | |
136 | list_for_each_entry(e, &table->iphash[h], list) |
137 | if (e->family == family && |
138 | memcmp(p: &e->addr, q: addrp, size: sizeof(e->addr)) == 0 && |
139 | (ttl == e->ttl || ttl == 0 || e->ttl == 0)) |
140 | return e; |
141 | return NULL; |
142 | } |
143 | |
144 | static void recent_entry_remove(struct recent_table *t, struct recent_entry *e) |
145 | { |
146 | list_del(entry: &e->list); |
147 | list_del(entry: &e->lru_list); |
148 | kfree(objp: e); |
149 | t->entries--; |
150 | } |
151 | |
152 | /* |
153 | * Drop entries with timestamps older then 'time'. |
154 | */ |
155 | static void recent_entry_reap(struct recent_table *t, unsigned long time, |
156 | struct recent_entry *working, bool update) |
157 | { |
158 | struct recent_entry *e; |
159 | |
160 | /* |
161 | * The head of the LRU list is always the oldest entry. |
162 | */ |
163 | e = list_entry(t->lru_list.next, struct recent_entry, lru_list); |
164 | |
165 | /* |
166 | * Do not reap the entry which are going to be updated. |
167 | */ |
168 | if (e == working && update) |
169 | return; |
170 | |
171 | /* |
172 | * The last time stamp is the most recent. |
173 | */ |
174 | if (time_after(time, e->stamps[e->index-1])) |
175 | recent_entry_remove(t, e); |
176 | } |
177 | |
178 | static struct recent_entry * |
179 | recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr, |
180 | u_int16_t family, u_int8_t ttl) |
181 | { |
182 | struct recent_entry *e; |
183 | unsigned int nstamps_max = t->nstamps_max_mask; |
184 | |
185 | if (t->entries >= ip_list_tot) { |
186 | e = list_entry(t->lru_list.next, struct recent_entry, lru_list); |
187 | recent_entry_remove(t, e); |
188 | } |
189 | |
190 | nstamps_max += 1; |
191 | e = kmalloc(struct_size(e, stamps, nstamps_max), GFP_ATOMIC); |
192 | if (e == NULL) |
193 | return NULL; |
194 | memcpy(&e->addr, addr, sizeof(e->addr)); |
195 | e->ttl = ttl; |
196 | e->stamps[0] = jiffies; |
197 | e->nstamps = 1; |
198 | e->index = 1; |
199 | e->family = family; |
200 | if (family == NFPROTO_IPV4) |
201 | list_add_tail(new: &e->list, head: &t->iphash[recent_entry_hash4(addr)]); |
202 | else |
203 | list_add_tail(new: &e->list, head: &t->iphash[recent_entry_hash6(addr)]); |
204 | list_add_tail(new: &e->lru_list, head: &t->lru_list); |
205 | t->entries++; |
206 | return e; |
207 | } |
208 | |
209 | static void recent_entry_update(struct recent_table *t, struct recent_entry *e) |
210 | { |
211 | e->index &= t->nstamps_max_mask; |
212 | e->stamps[e->index++] = jiffies; |
213 | if (e->index > e->nstamps) |
214 | e->nstamps = e->index; |
215 | list_move_tail(list: &e->lru_list, head: &t->lru_list); |
216 | } |
217 | |
218 | static struct recent_table *recent_table_lookup(struct recent_net *recent_net, |
219 | const char *name) |
220 | { |
221 | struct recent_table *t; |
222 | |
223 | list_for_each_entry(t, &recent_net->tables, list) |
224 | if (!strcmp(t->name, name)) |
225 | return t; |
226 | return NULL; |
227 | } |
228 | |
229 | static void recent_table_flush(struct recent_table *t) |
230 | { |
231 | struct recent_entry *e, *next; |
232 | unsigned int i; |
233 | |
234 | for (i = 0; i < ip_list_hash_size; i++) |
235 | list_for_each_entry_safe(e, next, &t->iphash[i], list) |
236 | recent_entry_remove(t, e); |
237 | } |
238 | |
239 | static bool |
240 | recent_mt(const struct sk_buff *skb, struct xt_action_param *par) |
241 | { |
242 | struct net *net = xt_net(par); |
243 | struct recent_net *recent_net = recent_pernet(net); |
244 | const struct xt_recent_mtinfo_v1 *info = par->matchinfo; |
245 | struct recent_table *t; |
246 | struct recent_entry *e; |
247 | union nf_inet_addr addr = {}, addr_mask; |
248 | u_int8_t ttl; |
249 | bool ret = info->invert; |
250 | |
251 | if (xt_family(par) == NFPROTO_IPV4) { |
252 | const struct iphdr *iph = ip_hdr(skb); |
253 | |
254 | if (info->side == XT_RECENT_DEST) |
255 | addr.ip = iph->daddr; |
256 | else |
257 | addr.ip = iph->saddr; |
258 | |
259 | ttl = iph->ttl; |
260 | } else { |
261 | const struct ipv6hdr *iph = ipv6_hdr(skb); |
262 | |
263 | if (info->side == XT_RECENT_DEST) |
264 | memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6)); |
265 | else |
266 | memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6)); |
267 | |
268 | ttl = iph->hop_limit; |
269 | } |
270 | |
271 | /* use TTL as seen before forwarding */ |
272 | if (xt_out(par) != NULL && |
273 | (!skb->sk || !net_eq(net1: net, net2: sock_net(sk: skb->sk)))) |
274 | ttl++; |
275 | |
276 | spin_lock_bh(lock: &recent_lock); |
277 | t = recent_table_lookup(recent_net, name: info->name); |
278 | |
279 | nf_inet_addr_mask(a1: &addr, result: &addr_mask, mask: &t->mask); |
280 | |
281 | e = recent_entry_lookup(table: t, addrp: &addr_mask, family: xt_family(par), |
282 | ttl: (info->check_set & XT_RECENT_TTL) ? ttl : 0); |
283 | if (e == NULL) { |
284 | if (!(info->check_set & XT_RECENT_SET)) |
285 | goto out; |
286 | e = recent_entry_init(t, addr: &addr_mask, family: xt_family(par), ttl); |
287 | if (e == NULL) |
288 | par->hotdrop = true; |
289 | ret = !ret; |
290 | goto out; |
291 | } |
292 | |
293 | if (info->check_set & XT_RECENT_SET) |
294 | ret = !ret; |
295 | else if (info->check_set & XT_RECENT_REMOVE) { |
296 | recent_entry_remove(t, e); |
297 | ret = !ret; |
298 | } else if (info->check_set & (XT_RECENT_CHECK | XT_RECENT_UPDATE)) { |
299 | unsigned long time = jiffies - info->seconds * HZ; |
300 | unsigned int i, hits = 0; |
301 | |
302 | for (i = 0; i < e->nstamps; i++) { |
303 | if (info->seconds && time_after(time, e->stamps[i])) |
304 | continue; |
305 | if (!info->hit_count || ++hits >= info->hit_count) { |
306 | ret = !ret; |
307 | break; |
308 | } |
309 | } |
310 | |
311 | /* info->seconds must be non-zero */ |
312 | if (info->check_set & XT_RECENT_REAP) |
313 | recent_entry_reap(t, time, working: e, |
314 | update: info->check_set & XT_RECENT_UPDATE && ret); |
315 | } |
316 | |
317 | if (info->check_set & XT_RECENT_SET || |
318 | (info->check_set & XT_RECENT_UPDATE && ret)) { |
319 | recent_entry_update(t, e); |
320 | e->ttl = ttl; |
321 | } |
322 | out: |
323 | spin_unlock_bh(lock: &recent_lock); |
324 | return ret; |
325 | } |
326 | |
327 | static void recent_table_free(void *addr) |
328 | { |
329 | kvfree(addr); |
330 | } |
331 | |
332 | static int recent_mt_check(const struct xt_mtchk_param *par, |
333 | const struct xt_recent_mtinfo_v1 *info) |
334 | { |
335 | struct recent_net *recent_net = recent_pernet(net: par->net); |
336 | struct recent_table *t; |
337 | #ifdef CONFIG_PROC_FS |
338 | struct proc_dir_entry *pde; |
339 | kuid_t uid; |
340 | kgid_t gid; |
341 | #endif |
342 | unsigned int nstamp_mask; |
343 | unsigned int i; |
344 | int ret = -EINVAL; |
345 | |
346 | net_get_random_once(&hash_rnd, sizeof(hash_rnd)); |
347 | |
348 | if (info->check_set & ~XT_RECENT_VALID_FLAGS) { |
349 | pr_info_ratelimited("Unsupported userspace flags (%08x)\n" , |
350 | info->check_set); |
351 | return -EINVAL; |
352 | } |
353 | if (hweight8(info->check_set & |
354 | (XT_RECENT_SET | XT_RECENT_REMOVE | |
355 | XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1) |
356 | return -EINVAL; |
357 | if ((info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE)) && |
358 | (info->seconds || info->hit_count || |
359 | (info->check_set & XT_RECENT_MODIFIERS))) |
360 | return -EINVAL; |
361 | if ((info->check_set & XT_RECENT_REAP) && !info->seconds) |
362 | return -EINVAL; |
363 | if (info->hit_count >= XT_RECENT_MAX_NSTAMPS) { |
364 | pr_info_ratelimited("hitcount (%u) is larger than allowed maximum (%u)\n" , |
365 | info->hit_count, XT_RECENT_MAX_NSTAMPS - 1); |
366 | return -EINVAL; |
367 | } |
368 | ret = xt_check_proc_name(name: info->name, size: sizeof(info->name)); |
369 | if (ret) |
370 | return ret; |
371 | |
372 | if (ip_pkt_list_tot && info->hit_count < ip_pkt_list_tot) |
373 | nstamp_mask = roundup_pow_of_two(ip_pkt_list_tot) - 1; |
374 | else if (info->hit_count) |
375 | nstamp_mask = roundup_pow_of_two(info->hit_count) - 1; |
376 | else |
377 | nstamp_mask = 32 - 1; |
378 | |
379 | mutex_lock(&recent_mutex); |
380 | t = recent_table_lookup(recent_net, name: info->name); |
381 | if (t != NULL) { |
382 | if (nstamp_mask > t->nstamps_max_mask) { |
383 | spin_lock_bh(lock: &recent_lock); |
384 | recent_table_flush(t); |
385 | t->nstamps_max_mask = nstamp_mask; |
386 | spin_unlock_bh(lock: &recent_lock); |
387 | } |
388 | |
389 | t->refcnt++; |
390 | ret = 0; |
391 | goto out; |
392 | } |
393 | |
394 | t = kvzalloc(struct_size(t, iphash, ip_list_hash_size), GFP_KERNEL); |
395 | if (t == NULL) { |
396 | ret = -ENOMEM; |
397 | goto out; |
398 | } |
399 | t->refcnt = 1; |
400 | t->nstamps_max_mask = nstamp_mask; |
401 | |
402 | memcpy(&t->mask, &info->mask, sizeof(t->mask)); |
403 | strcpy(p: t->name, q: info->name); |
404 | INIT_LIST_HEAD(list: &t->lru_list); |
405 | for (i = 0; i < ip_list_hash_size; i++) |
406 | INIT_LIST_HEAD(list: &t->iphash[i]); |
407 | #ifdef CONFIG_PROC_FS |
408 | uid = make_kuid(from: &init_user_ns, uid: ip_list_uid); |
409 | gid = make_kgid(from: &init_user_ns, gid: ip_list_gid); |
410 | if (!uid_valid(uid) || !gid_valid(gid)) { |
411 | recent_table_free(addr: t); |
412 | ret = -EINVAL; |
413 | goto out; |
414 | } |
415 | pde = proc_create_data(t->name, ip_list_perms, recent_net->xt_recent, |
416 | &recent_mt_proc_ops, t); |
417 | if (pde == NULL) { |
418 | recent_table_free(addr: t); |
419 | ret = -ENOMEM; |
420 | goto out; |
421 | } |
422 | proc_set_user(pde, uid, gid); |
423 | #endif |
424 | spin_lock_bh(lock: &recent_lock); |
425 | list_add_tail(new: &t->list, head: &recent_net->tables); |
426 | spin_unlock_bh(lock: &recent_lock); |
427 | ret = 0; |
428 | out: |
429 | mutex_unlock(lock: &recent_mutex); |
430 | return ret; |
431 | } |
432 | |
433 | static int recent_mt_check_v0(const struct xt_mtchk_param *par) |
434 | { |
435 | const struct xt_recent_mtinfo_v0 *info_v0 = par->matchinfo; |
436 | struct xt_recent_mtinfo_v1 info_v1; |
437 | |
438 | /* Copy revision 0 structure to revision 1 */ |
439 | memcpy(&info_v1, info_v0, sizeof(struct xt_recent_mtinfo)); |
440 | /* Set default mask to ensure backward compatible behaviour */ |
441 | memset(info_v1.mask.all, 0xFF, sizeof(info_v1.mask.all)); |
442 | |
443 | return recent_mt_check(par, info: &info_v1); |
444 | } |
445 | |
446 | static int recent_mt_check_v1(const struct xt_mtchk_param *par) |
447 | { |
448 | return recent_mt_check(par, info: par->matchinfo); |
449 | } |
450 | |
451 | static void recent_mt_destroy(const struct xt_mtdtor_param *par) |
452 | { |
453 | struct recent_net *recent_net = recent_pernet(net: par->net); |
454 | const struct xt_recent_mtinfo_v1 *info = par->matchinfo; |
455 | struct recent_table *t; |
456 | |
457 | mutex_lock(&recent_mutex); |
458 | t = recent_table_lookup(recent_net, name: info->name); |
459 | if (--t->refcnt == 0) { |
460 | spin_lock_bh(lock: &recent_lock); |
461 | list_del(entry: &t->list); |
462 | spin_unlock_bh(lock: &recent_lock); |
463 | #ifdef CONFIG_PROC_FS |
464 | if (recent_net->xt_recent != NULL) |
465 | remove_proc_entry(t->name, recent_net->xt_recent); |
466 | #endif |
467 | recent_table_flush(t); |
468 | recent_table_free(addr: t); |
469 | } |
470 | mutex_unlock(lock: &recent_mutex); |
471 | } |
472 | |
473 | #ifdef CONFIG_PROC_FS |
474 | struct recent_iter_state { |
475 | const struct recent_table *table; |
476 | unsigned int bucket; |
477 | }; |
478 | |
479 | static void *recent_seq_start(struct seq_file *seq, loff_t *pos) |
480 | __acquires(recent_lock) |
481 | { |
482 | struct recent_iter_state *st = seq->private; |
483 | const struct recent_table *t = st->table; |
484 | struct recent_entry *e; |
485 | loff_t p = *pos; |
486 | |
487 | spin_lock_bh(lock: &recent_lock); |
488 | |
489 | for (st->bucket = 0; st->bucket < ip_list_hash_size; st->bucket++) |
490 | list_for_each_entry(e, &t->iphash[st->bucket], list) |
491 | if (p-- == 0) |
492 | return e; |
493 | return NULL; |
494 | } |
495 | |
496 | static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
497 | { |
498 | struct recent_iter_state *st = seq->private; |
499 | const struct recent_table *t = st->table; |
500 | const struct recent_entry *e = v; |
501 | const struct list_head *head = e->list.next; |
502 | |
503 | (*pos)++; |
504 | while (head == &t->iphash[st->bucket]) { |
505 | if (++st->bucket >= ip_list_hash_size) |
506 | return NULL; |
507 | head = t->iphash[st->bucket].next; |
508 | } |
509 | return list_entry(head, struct recent_entry, list); |
510 | } |
511 | |
512 | static void recent_seq_stop(struct seq_file *s, void *v) |
513 | __releases(recent_lock) |
514 | { |
515 | spin_unlock_bh(lock: &recent_lock); |
516 | } |
517 | |
518 | static int recent_seq_show(struct seq_file *seq, void *v) |
519 | { |
520 | const struct recent_entry *e = v; |
521 | struct recent_iter_state *st = seq->private; |
522 | const struct recent_table *t = st->table; |
523 | unsigned int i; |
524 | |
525 | i = (e->index - 1) & t->nstamps_max_mask; |
526 | |
527 | if (e->family == NFPROTO_IPV4) |
528 | seq_printf(m: seq, fmt: "src=%pI4 ttl: %u last_seen: %lu oldest_pkt: %u" , |
529 | &e->addr.ip, e->ttl, e->stamps[i], e->index); |
530 | else |
531 | seq_printf(m: seq, fmt: "src=%pI6 ttl: %u last_seen: %lu oldest_pkt: %u" , |
532 | &e->addr.in6, e->ttl, e->stamps[i], e->index); |
533 | for (i = 0; i < e->nstamps; i++) |
534 | seq_printf(m: seq, fmt: "%s %lu" , i ? "," : "" , e->stamps[i]); |
535 | seq_putc(m: seq, c: '\n'); |
536 | return 0; |
537 | } |
538 | |
539 | static const struct seq_operations recent_seq_ops = { |
540 | .start = recent_seq_start, |
541 | .next = recent_seq_next, |
542 | .stop = recent_seq_stop, |
543 | .show = recent_seq_show, |
544 | }; |
545 | |
546 | static int recent_seq_open(struct inode *inode, struct file *file) |
547 | { |
548 | struct recent_iter_state *st; |
549 | |
550 | st = __seq_open_private(file, &recent_seq_ops, sizeof(*st)); |
551 | if (st == NULL) |
552 | return -ENOMEM; |
553 | |
554 | st->table = pde_data(inode); |
555 | return 0; |
556 | } |
557 | |
558 | static ssize_t |
559 | recent_mt_proc_write(struct file *file, const char __user *input, |
560 | size_t size, loff_t *loff) |
561 | { |
562 | struct recent_table *t = pde_data(inode: file_inode(f: file)); |
563 | struct recent_entry *e; |
564 | char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de" )]; |
565 | const char *c = buf; |
566 | union nf_inet_addr addr = {}; |
567 | u_int16_t family; |
568 | bool add, succ; |
569 | |
570 | if (size == 0) |
571 | return 0; |
572 | if (size > sizeof(buf)) |
573 | size = sizeof(buf); |
574 | if (copy_from_user(to: buf, from: input, n: size) != 0) |
575 | return -EFAULT; |
576 | |
577 | /* Strict protocol! */ |
578 | if (*loff != 0) |
579 | return -ESPIPE; |
580 | switch (*c) { |
581 | case '/': /* flush table */ |
582 | spin_lock_bh(lock: &recent_lock); |
583 | recent_table_flush(t); |
584 | spin_unlock_bh(lock: &recent_lock); |
585 | return size; |
586 | case '-': /* remove address */ |
587 | add = false; |
588 | break; |
589 | case '+': /* add address */ |
590 | add = true; |
591 | break; |
592 | default: |
593 | pr_info_ratelimited("Need \"+ip\", \"-ip\" or \"/\"\n" ); |
594 | return -EINVAL; |
595 | } |
596 | |
597 | ++c; |
598 | --size; |
599 | if (strnchr(c, size, ':') != NULL) { |
600 | family = NFPROTO_IPV6; |
601 | succ = in6_pton(src: c, srclen: size, dst: (void *)&addr, delim: '\n', NULL); |
602 | } else { |
603 | family = NFPROTO_IPV4; |
604 | succ = in4_pton(src: c, srclen: size, dst: (void *)&addr, delim: '\n', NULL); |
605 | } |
606 | |
607 | if (!succ) |
608 | return -EINVAL; |
609 | |
610 | spin_lock_bh(lock: &recent_lock); |
611 | e = recent_entry_lookup(table: t, addrp: &addr, family, ttl: 0); |
612 | if (e == NULL) { |
613 | if (add) |
614 | recent_entry_init(t, addr: &addr, family, ttl: 0); |
615 | } else { |
616 | if (add) |
617 | recent_entry_update(t, e); |
618 | else |
619 | recent_entry_remove(t, e); |
620 | } |
621 | spin_unlock_bh(lock: &recent_lock); |
622 | /* Note we removed one above */ |
623 | *loff += size + 1; |
624 | return size + 1; |
625 | } |
626 | |
627 | static const struct proc_ops recent_mt_proc_ops = { |
628 | .proc_open = recent_seq_open, |
629 | .proc_read = seq_read, |
630 | .proc_write = recent_mt_proc_write, |
631 | .proc_release = seq_release_private, |
632 | .proc_lseek = seq_lseek, |
633 | }; |
634 | |
635 | static int __net_init recent_proc_net_init(struct net *net) |
636 | { |
637 | struct recent_net *recent_net = recent_pernet(net); |
638 | |
639 | recent_net->xt_recent = proc_mkdir("xt_recent" , net->proc_net); |
640 | if (!recent_net->xt_recent) |
641 | return -ENOMEM; |
642 | return 0; |
643 | } |
644 | |
645 | static void __net_exit recent_proc_net_exit(struct net *net) |
646 | { |
647 | struct recent_net *recent_net = recent_pernet(net); |
648 | struct recent_table *t; |
649 | |
650 | /* recent_net_exit() is called before recent_mt_destroy(). Make sure |
651 | * that the parent xt_recent proc entry is empty before trying to |
652 | * remove it. |
653 | */ |
654 | spin_lock_bh(lock: &recent_lock); |
655 | list_for_each_entry(t, &recent_net->tables, list) |
656 | remove_proc_entry(t->name, recent_net->xt_recent); |
657 | |
658 | recent_net->xt_recent = NULL; |
659 | spin_unlock_bh(lock: &recent_lock); |
660 | |
661 | remove_proc_entry("xt_recent" , net->proc_net); |
662 | } |
663 | #else |
664 | static inline int recent_proc_net_init(struct net *net) |
665 | { |
666 | return 0; |
667 | } |
668 | |
669 | static inline void recent_proc_net_exit(struct net *net) |
670 | { |
671 | } |
672 | #endif /* CONFIG_PROC_FS */ |
673 | |
674 | static int __net_init recent_net_init(struct net *net) |
675 | { |
676 | struct recent_net *recent_net = recent_pernet(net); |
677 | |
678 | INIT_LIST_HEAD(list: &recent_net->tables); |
679 | return recent_proc_net_init(net); |
680 | } |
681 | |
682 | static void __net_exit recent_net_exit(struct net *net) |
683 | { |
684 | recent_proc_net_exit(net); |
685 | } |
686 | |
687 | static struct pernet_operations recent_net_ops = { |
688 | .init = recent_net_init, |
689 | .exit = recent_net_exit, |
690 | .id = &recent_net_id, |
691 | .size = sizeof(struct recent_net), |
692 | }; |
693 | |
694 | static struct xt_match recent_mt_reg[] __read_mostly = { |
695 | { |
696 | .name = "recent" , |
697 | .revision = 0, |
698 | .family = NFPROTO_IPV4, |
699 | .match = recent_mt, |
700 | .matchsize = sizeof(struct xt_recent_mtinfo), |
701 | .checkentry = recent_mt_check_v0, |
702 | .destroy = recent_mt_destroy, |
703 | .me = THIS_MODULE, |
704 | }, |
705 | { |
706 | .name = "recent" , |
707 | .revision = 0, |
708 | .family = NFPROTO_IPV6, |
709 | .match = recent_mt, |
710 | .matchsize = sizeof(struct xt_recent_mtinfo), |
711 | .checkentry = recent_mt_check_v0, |
712 | .destroy = recent_mt_destroy, |
713 | .me = THIS_MODULE, |
714 | }, |
715 | { |
716 | .name = "recent" , |
717 | .revision = 1, |
718 | .family = NFPROTO_IPV4, |
719 | .match = recent_mt, |
720 | .matchsize = sizeof(struct xt_recent_mtinfo_v1), |
721 | .checkentry = recent_mt_check_v1, |
722 | .destroy = recent_mt_destroy, |
723 | .me = THIS_MODULE, |
724 | }, |
725 | { |
726 | .name = "recent" , |
727 | .revision = 1, |
728 | .family = NFPROTO_IPV6, |
729 | .match = recent_mt, |
730 | .matchsize = sizeof(struct xt_recent_mtinfo_v1), |
731 | .checkentry = recent_mt_check_v1, |
732 | .destroy = recent_mt_destroy, |
733 | .me = THIS_MODULE, |
734 | } |
735 | }; |
736 | |
737 | static int __init recent_mt_init(void) |
738 | { |
739 | int err; |
740 | |
741 | BUILD_BUG_ON_NOT_POWER_OF_2(XT_RECENT_MAX_NSTAMPS); |
742 | |
743 | if (!ip_list_tot || ip_pkt_list_tot >= XT_RECENT_MAX_NSTAMPS) |
744 | return -EINVAL; |
745 | ip_list_hash_size = 1 << fls(x: ip_list_tot); |
746 | |
747 | err = register_pernet_subsys(&recent_net_ops); |
748 | if (err) |
749 | return err; |
750 | err = xt_register_matches(match: recent_mt_reg, ARRAY_SIZE(recent_mt_reg)); |
751 | if (err) |
752 | unregister_pernet_subsys(&recent_net_ops); |
753 | return err; |
754 | } |
755 | |
756 | static void __exit recent_mt_exit(void) |
757 | { |
758 | xt_unregister_matches(match: recent_mt_reg, ARRAY_SIZE(recent_mt_reg)); |
759 | unregister_pernet_subsys(&recent_net_ops); |
760 | } |
761 | |
762 | module_init(recent_mt_init); |
763 | module_exit(recent_mt_exit); |
764 | |