| 1 | /* |
| 2 | * Copyright (c) 2006 Patrick McHardy <kaber@trash.net> |
| 3 | * Copyright © CC Computer Consultants GmbH, 2007 - 2008 |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * This is a replacement of the old ipt_recent module, which carried the |
| 10 | * following copyright notice: |
| 11 | * |
| 12 | * Author: Stephen Frost <sfrost@snowman.net> |
| 13 | * Copyright 2002-2003, Stephen Frost, 2.5.x port by laforge@netfilter.org |
| 14 | */ |
| 15 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 16 | #include <linux/init.h> |
| 17 | #include <linux/ip.h> |
| 18 | #include <linux/ipv6.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/moduleparam.h> |
| 21 | #include <linux/proc_fs.h> |
| 22 | #include <linux/seq_file.h> |
| 23 | #include <linux/string.h> |
| 24 | #include <linux/ctype.h> |
| 25 | #include <linux/list.h> |
| 26 | #include <linux/random.h> |
| 27 | #include <linux/jhash.h> |
| 28 | #include <linux/bitops.h> |
| 29 | #include <linux/skbuff.h> |
| 30 | #include <linux/inet.h> |
| 31 | #include <linux/slab.h> |
| 32 | #include <linux/vmalloc.h> |
| 33 | #include <net/net_namespace.h> |
| 34 | #include <net/netns/generic.h> |
| 35 | |
| 36 | #include <linux/netfilter/x_tables.h> |
| 37 | #include <linux/netfilter/xt_recent.h> |
| 38 | |
| 39 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |
| 40 | MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); |
| 41 | MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching"); |
| 42 | MODULE_LICENSE("GPL"); |
| 43 | MODULE_ALIAS("ipt_recent"); |
| 44 | MODULE_ALIAS("ip6t_recent"); |
| 45 | |
| 46 | static unsigned int ip_list_tot __read_mostly = 100; |
| 47 | static unsigned int ip_list_hash_size __read_mostly; |
| 48 | static unsigned int ip_list_perms __read_mostly = 0644; |
| 49 | static unsigned int ip_list_uid __read_mostly; |
| 50 | static unsigned int ip_list_gid __read_mostly; |
| 51 | module_param(ip_list_tot, uint, 0400); |
| 52 | module_param(ip_list_hash_size, uint, 0400); |
| 53 | module_param(ip_list_perms, uint, 0400); |
| 54 | module_param(ip_list_uid, uint, S_IRUGO | S_IWUSR); |
| 55 | module_param(ip_list_gid, uint, S_IRUGO | S_IWUSR); |
| 56 | MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list"); |
| 57 | MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs"); |
| 58 | MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files"); |
| 59 | MODULE_PARM_DESC(ip_list_uid, "default owner of /proc/net/xt_recent/* files"); |
| 60 | MODULE_PARM_DESC(ip_list_gid, "default owning group of /proc/net/xt_recent/* files"); |
| 61 | |
| 62 | /* retained for backwards compatibility */ |
| 63 | static unsigned int ip_pkt_list_tot __read_mostly; |
| 64 | module_param(ip_pkt_list_tot, uint, 0400); |
| 65 | MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP address to remember (max. 255)"); |
| 66 | |
| 67 | #define XT_RECENT_MAX_NSTAMPS 256 |
| 68 | |
| 69 | struct recent_entry { |
| 70 | struct list_head list; |
| 71 | struct list_head lru_list; |
| 72 | union nf_inet_addr addr; |
| 73 | u_int16_t family; |
| 74 | u_int8_t ttl; |
| 75 | u_int8_t index; |
| 76 | u_int16_t nstamps; |
| 77 | unsigned long stamps[0]; |
| 78 | }; |
| 79 | |
| 80 | struct recent_table { |
| 81 | struct list_head list; |
| 82 | char name[XT_RECENT_NAME_LEN]; |
| 83 | union nf_inet_addr mask; |
| 84 | unsigned int refcnt; |
| 85 | unsigned int entries; |
| 86 | u8 nstamps_max_mask; |
| 87 | struct list_head lru_list; |
| 88 | struct list_head iphash[0]; |
| 89 | }; |
| 90 | |
| 91 | struct recent_net { |
| 92 | struct list_head tables; |
| 93 | #ifdef CONFIG_PROC_FS |
| 94 | struct proc_dir_entry *xt_recent; |
| 95 | #endif |
| 96 | }; |
| 97 | |
| 98 | static int recent_net_id __read_mostly; |
| 99 | |
| 100 | static inline struct recent_net *recent_pernet(struct net *net) |
| 101 | { |
| 102 | return net_generic(net, recent_net_id); |
| 103 | } |
| 104 | |
| 105 | static DEFINE_SPINLOCK(recent_lock); |
| 106 | static DEFINE_MUTEX(recent_mutex); |
| 107 | |
| 108 | #ifdef CONFIG_PROC_FS |
| 109 | static const struct file_operations recent_old_fops, recent_mt_fops; |
| 110 | #endif |
| 111 | |
| 112 | static u_int32_t hash_rnd __read_mostly; |
| 113 | static bool hash_rnd_inited __read_mostly; |
| 114 | |
| 115 | static inline unsigned int recent_entry_hash4(const union nf_inet_addr *addr) |
| 116 | { |
| 117 | return jhash_1word((__force u32)addr->ip, hash_rnd) & |
| 118 | (ip_list_hash_size - 1); |
| 119 | } |
| 120 | |
| 121 | static inline unsigned int recent_entry_hash6(const union nf_inet_addr *addr) |
| 122 | { |
| 123 | return jhash2((u32 *)addr->ip6, ARRAY_SIZE(addr->ip6), hash_rnd) & |
| 124 | (ip_list_hash_size - 1); |
| 125 | } |
| 126 | |
| 127 | static struct recent_entry * |
| 128 | recent_entry_lookup(const struct recent_table *table, |
| 129 | const union nf_inet_addr *addrp, u_int16_t family, |
| 130 | u_int8_t ttl) |
| 131 | { |
| 132 | struct recent_entry *e; |
| 133 | unsigned int h; |
| 134 | |
| 135 | if (family == NFPROTO_IPV4) |
| 136 | h = recent_entry_hash4(addrp); |
| 137 | else |
| 138 | h = recent_entry_hash6(addrp); |
| 139 | |
| 140 | list_for_each_entry(e, &table->iphash[h], list) |
| 141 | if (e->family == family && |
| 142 | memcmp(&e->addr, addrp, sizeof(e->addr)) == 0 && |
| 143 | (ttl == e->ttl || ttl == 0 || e->ttl == 0)) |
| 144 | return e; |
| 145 | return NULL; |
| 146 | } |
| 147 | |
| 148 | static void recent_entry_remove(struct recent_table *t, struct recent_entry *e) |
| 149 | { |
| 150 | list_del(&e->list); |
| 151 | list_del(&e->lru_list); |
| 152 | kfree(e); |
| 153 | t->entries--; |
| 154 | } |
| 155 | |
| 156 | /* |
| 157 | * Drop entries with timestamps older then 'time'. |
| 158 | */ |
| 159 | static void recent_entry_reap(struct recent_table *t, unsigned long time) |
| 160 | { |
| 161 | struct recent_entry *e; |
| 162 | |
| 163 | /* |
| 164 | * The head of the LRU list is always the oldest entry. |
| 165 | */ |
| 166 | e = list_entry(t->lru_list.next, struct recent_entry, lru_list); |
| 167 | |
| 168 | /* |
| 169 | * The last time stamp is the most recent. |
| 170 | */ |
| 171 | if (time_after(time, e->stamps[e->index-1])) |
| 172 | recent_entry_remove(t, e); |
| 173 | } |
| 174 | |
| 175 | static struct recent_entry * |
| 176 | recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr, |
| 177 | u_int16_t family, u_int8_t ttl) |
| 178 | { |
| 179 | struct recent_entry *e; |
| 180 | unsigned int nstamps_max = t->nstamps_max_mask; |
| 181 | |
| 182 | if (t->entries >= ip_list_tot) { |
| 183 | e = list_entry(t->lru_list.next, struct recent_entry, lru_list); |
| 184 | recent_entry_remove(t, e); |
| 185 | } |
| 186 | |
| 187 | nstamps_max += 1; |
| 188 | e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * nstamps_max, |
| 189 | GFP_ATOMIC); |
| 190 | if (e == NULL) |
| 191 | return NULL; |
| 192 | memcpy(&e->addr, addr, sizeof(e->addr)); |
| 193 | e->ttl = ttl; |
| 194 | e->stamps[0] = jiffies; |
| 195 | e->nstamps = 1; |
| 196 | e->index = 1; |
| 197 | e->family = family; |
| 198 | if (family == NFPROTO_IPV4) |
| 199 | list_add_tail(&e->list, &t->iphash[recent_entry_hash4(addr)]); |
| 200 | else |
| 201 | list_add_tail(&e->list, &t->iphash[recent_entry_hash6(addr)]); |
| 202 | list_add_tail(&e->lru_list, &t->lru_list); |
| 203 | t->entries++; |
| 204 | return e; |
| 205 | } |
| 206 | |
| 207 | static void recent_entry_update(struct recent_table *t, struct recent_entry *e) |
| 208 | { |
| 209 | e->index &= t->nstamps_max_mask; |
| 210 | e->stamps[e->index++] = jiffies; |
| 211 | if (e->index > e->nstamps) |
| 212 | e->nstamps = e->index; |
| 213 | list_move_tail(&e->lru_list, &t->lru_list); |
| 214 | } |
| 215 | |
| 216 | static struct recent_table *recent_table_lookup(struct recent_net *recent_net, |
| 217 | const char *name) |
| 218 | { |
| 219 | struct recent_table *t; |
| 220 | |
| 221 | list_for_each_entry(t, &recent_net->tables, list) |
| 222 | if (!strcmp(t->name, name)) |
| 223 | return t; |
| 224 | return NULL; |
| 225 | } |
| 226 | |
| 227 | static void recent_table_flush(struct recent_table *t) |
| 228 | { |
| 229 | struct recent_entry *e, *next; |
| 230 | unsigned int i; |
| 231 | |
| 232 | for (i = 0; i < ip_list_hash_size; i++) |
| 233 | list_for_each_entry_safe(e, next, &t->iphash[i], list) |
| 234 | recent_entry_remove(t, e); |
| 235 | } |
| 236 | |
| 237 | static bool |
| 238 | recent_mt(const struct sk_buff *skb, struct xt_action_param *par) |
| 239 | { |
| 240 | struct net *net = par->net; |
| 241 | struct recent_net *recent_net = recent_pernet(net); |
| 242 | const struct xt_recent_mtinfo_v1 *info = par->matchinfo; |
| 243 | struct recent_table *t; |
| 244 | struct recent_entry *e; |
| 245 | union nf_inet_addr addr = {}, addr_mask; |
| 246 | u_int8_t ttl; |
| 247 | bool ret = info->invert; |
| 248 | |
| 249 | if (par->family == NFPROTO_IPV4) { |
| 250 | const struct iphdr *iph = ip_hdr(skb); |
| 251 | |
| 252 | if (info->side == XT_RECENT_DEST) |
| 253 | addr.ip = iph->daddr; |
| 254 | else |
| 255 | addr.ip = iph->saddr; |
| 256 | |
| 257 | ttl = iph->ttl; |
| 258 | } else { |
| 259 | const struct ipv6hdr *iph = ipv6_hdr(skb); |
| 260 | |
| 261 | if (info->side == XT_RECENT_DEST) |
| 262 | memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6)); |
| 263 | else |
| 264 | memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6)); |
| 265 | |
| 266 | ttl = iph->hop_limit; |
| 267 | } |
| 268 | |
| 269 | /* use TTL as seen before forwarding */ |
| 270 | if (par->out != NULL && skb->sk == NULL) |
| 271 | ttl++; |
| 272 | |
| 273 | spin_lock_bh(&recent_lock); |
| 274 | t = recent_table_lookup(recent_net, info->name); |
| 275 | |
| 276 | nf_inet_addr_mask(&addr, &addr_mask, &t->mask); |
| 277 | |
| 278 | e = recent_entry_lookup(t, &addr_mask, par->family, |
| 279 | (info->check_set & XT_RECENT_TTL) ? ttl : 0); |
| 280 | if (e == NULL) { |
| 281 | if (!(info->check_set & XT_RECENT_SET)) |
| 282 | goto out; |
| 283 | e = recent_entry_init(t, &addr_mask, par->family, ttl); |
| 284 | if (e == NULL) |
| 285 | par->hotdrop = true; |
| 286 | ret = !ret; |
| 287 | goto out; |
| 288 | } |
| 289 | |
| 290 | if (info->check_set & XT_RECENT_SET) |
| 291 | ret = !ret; |
| 292 | else if (info->check_set & XT_RECENT_REMOVE) { |
| 293 | recent_entry_remove(t, e); |
| 294 | ret = !ret; |
| 295 | } else if (info->check_set & (XT_RECENT_CHECK | XT_RECENT_UPDATE)) { |
| 296 | unsigned long time = jiffies - info->seconds * HZ; |
| 297 | unsigned int i, hits = 0; |
| 298 | |
| 299 | for (i = 0; i < e->nstamps; i++) { |
| 300 | if (info->seconds && time_after(time, e->stamps[i])) |
| 301 | continue; |
| 302 | if (!info->hit_count || ++hits >= info->hit_count) { |
| 303 | ret = !ret; |
| 304 | break; |
| 305 | } |
| 306 | } |
| 307 | |
| 308 | /* info->seconds must be non-zero */ |
| 309 | if (info->check_set & XT_RECENT_REAP) |
| 310 | recent_entry_reap(t, time); |
| 311 | } |
| 312 | |
| 313 | if (info->check_set & XT_RECENT_SET || |
| 314 | (info->check_set & XT_RECENT_UPDATE && ret)) { |
| 315 | recent_entry_update(t, e); |
| 316 | e->ttl = ttl; |
| 317 | } |
| 318 | out: |
| 319 | spin_unlock_bh(&recent_lock); |
| 320 | return ret; |
| 321 | } |
| 322 | |
| 323 | static void recent_table_free(void *addr) |
| 324 | { |
| 325 | kvfree(addr); |
| 326 | } |
| 327 | |
| 328 | static int recent_mt_check(const struct xt_mtchk_param *par, |
| 329 | const struct xt_recent_mtinfo_v1 *info) |
| 330 | { |
| 331 | struct recent_net *recent_net = recent_pernet(par->net); |
| 332 | struct recent_table *t; |
| 333 | #ifdef CONFIG_PROC_FS |
| 334 | struct proc_dir_entry *pde; |
| 335 | kuid_t uid; |
| 336 | kgid_t gid; |
| 337 | #endif |
| 338 | unsigned int nstamp_mask; |
| 339 | unsigned int i; |
| 340 | int ret = -EINVAL; |
| 341 | size_t sz; |
| 342 | |
| 343 | if (unlikely(!hash_rnd_inited)) { |
| 344 | get_random_bytes(&hash_rnd, sizeof(hash_rnd)); |
| 345 | hash_rnd_inited = true; |
| 346 | } |
| 347 | if (info->check_set & ~XT_RECENT_VALID_FLAGS) { |
| 348 | pr_info("Unsupported user space flags (%08x)\n", |
| 349 | info->check_set); |
| 350 | return -EINVAL; |
| 351 | } |
| 352 | if (hweight8(info->check_set & |
| 353 | (XT_RECENT_SET | XT_RECENT_REMOVE | |
| 354 | XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1) |
| 355 | return -EINVAL; |
| 356 | if ((info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE)) && |
| 357 | (info->seconds || info->hit_count || |
| 358 | (info->check_set & XT_RECENT_MODIFIERS))) |
| 359 | return -EINVAL; |
| 360 | if ((info->check_set & XT_RECENT_REAP) && !info->seconds) |
| 361 | return -EINVAL; |
| 362 | if (info->hit_count >= XT_RECENT_MAX_NSTAMPS) { |
| 363 | pr_info("hitcount (%u) is larger than allowed maximum (%u)\n", |
| 364 | info->hit_count, XT_RECENT_MAX_NSTAMPS - 1); |
| 365 | return -EINVAL; |
| 366 | } |
| 367 | if (info->name[0] == '\0' || |
| 368 | strnlen(info->name, XT_RECENT_NAME_LEN) == XT_RECENT_NAME_LEN) |
| 369 | return -EINVAL; |
| 370 | |
| 371 | if (ip_pkt_list_tot && info->hit_count < ip_pkt_list_tot) |
| 372 | nstamp_mask = roundup_pow_of_two(ip_pkt_list_tot) - 1; |
| 373 | else if (info->hit_count) |
| 374 | nstamp_mask = roundup_pow_of_two(info->hit_count) - 1; |
| 375 | else |
| 376 | nstamp_mask = 32 - 1; |
| 377 | |
| 378 | mutex_lock(&recent_mutex); |
| 379 | t = recent_table_lookup(recent_net, info->name); |
| 380 | if (t != NULL) { |
| 381 | if (nstamp_mask > t->nstamps_max_mask) { |
| 382 | spin_lock_bh(&recent_lock); |
| 383 | recent_table_flush(t); |
| 384 | t->nstamps_max_mask = nstamp_mask; |
| 385 | spin_unlock_bh(&recent_lock); |
| 386 | } |
| 387 | |
| 388 | t->refcnt++; |
| 389 | ret = 0; |
| 390 | goto out; |
| 391 | } |
| 392 | |
| 393 | sz = sizeof(*t) + sizeof(t->iphash[0]) * ip_list_hash_size; |
| 394 | if (sz <= PAGE_SIZE) |
| 395 | t = kzalloc(sz, GFP_KERNEL); |
| 396 | else |
| 397 | t = vzalloc(sz); |
| 398 | if (t == NULL) { |
| 399 | ret = -ENOMEM; |
| 400 | goto out; |
| 401 | } |
| 402 | t->refcnt = 1; |
| 403 | t->nstamps_max_mask = nstamp_mask; |
| 404 | |
| 405 | memcpy(&t->mask, &info->mask, sizeof(t->mask)); |
| 406 | strcpy(t->name, info->name); |
| 407 | INIT_LIST_HEAD(&t->lru_list); |
| 408 | for (i = 0; i < ip_list_hash_size; i++) |
| 409 | INIT_LIST_HEAD(&t->iphash[i]); |
| 410 | #ifdef CONFIG_PROC_FS |
| 411 | uid = make_kuid(&init_user_ns, ip_list_uid); |
| 412 | gid = make_kgid(&init_user_ns, ip_list_gid); |
| 413 | if (!uid_valid(uid) || !gid_valid(gid)) { |
| 414 | recent_table_free(t); |
| 415 | ret = -EINVAL; |
| 416 | goto out; |
| 417 | } |
| 418 | pde = proc_create_data(t->name, ip_list_perms, recent_net->xt_recent, |
| 419 | &recent_mt_fops, t); |
| 420 | if (pde == NULL) { |
| 421 | recent_table_free(t); |
| 422 | ret = -ENOMEM; |
| 423 | goto out; |
| 424 | } |
| 425 | proc_set_user(pde, uid, gid); |
| 426 | #endif |
| 427 | spin_lock_bh(&recent_lock); |
| 428 | list_add_tail(&t->list, &recent_net->tables); |
| 429 | spin_unlock_bh(&recent_lock); |
| 430 | ret = 0; |
| 431 | out: |
| 432 | mutex_unlock(&recent_mutex); |
| 433 | return ret; |
| 434 | } |
| 435 | |
| 436 | static int recent_mt_check_v0(const struct xt_mtchk_param *par) |
| 437 | { |
| 438 | const struct xt_recent_mtinfo_v0 *info_v0 = par->matchinfo; |
| 439 | struct xt_recent_mtinfo_v1 info_v1; |
| 440 | |
| 441 | /* Copy revision 0 structure to revision 1 */ |
| 442 | memcpy(&info_v1, info_v0, sizeof(struct xt_recent_mtinfo)); |
| 443 | /* Set default mask to ensure backward compatible behaviour */ |
| 444 | memset(info_v1.mask.all, 0xFF, sizeof(info_v1.mask.all)); |
| 445 | |
| 446 | return recent_mt_check(par, &info_v1); |
| 447 | } |
| 448 | |
| 449 | static int recent_mt_check_v1(const struct xt_mtchk_param *par) |
| 450 | { |
| 451 | return recent_mt_check(par, par->matchinfo); |
| 452 | } |
| 453 | |
| 454 | static void recent_mt_destroy(const struct xt_mtdtor_param *par) |
| 455 | { |
| 456 | struct recent_net *recent_net = recent_pernet(par->net); |
| 457 | const struct xt_recent_mtinfo_v1 *info = par->matchinfo; |
| 458 | struct recent_table *t; |
| 459 | |
| 460 | mutex_lock(&recent_mutex); |
| 461 | t = recent_table_lookup(recent_net, info->name); |
| 462 | if (--t->refcnt == 0) { |
| 463 | spin_lock_bh(&recent_lock); |
| 464 | list_del(&t->list); |
| 465 | spin_unlock_bh(&recent_lock); |
| 466 | #ifdef CONFIG_PROC_FS |
| 467 | if (recent_net->xt_recent != NULL) |
| 468 | remove_proc_entry(t->name, recent_net->xt_recent); |
| 469 | #endif |
| 470 | recent_table_flush(t); |
| 471 | recent_table_free(t); |
| 472 | } |
| 473 | mutex_unlock(&recent_mutex); |
| 474 | } |
| 475 | |
| 476 | #ifdef CONFIG_PROC_FS |
| 477 | struct recent_iter_state { |
| 478 | const struct recent_table *table; |
| 479 | unsigned int bucket; |
| 480 | }; |
| 481 | |
| 482 | static void *recent_seq_start(struct seq_file *seq, loff_t *pos) |
| 483 | __acquires(recent_lock) |
| 484 | { |
| 485 | struct recent_iter_state *st = seq->private; |
| 486 | const struct recent_table *t = st->table; |
| 487 | struct recent_entry *e; |
| 488 | loff_t p = *pos; |
| 489 | |
| 490 | spin_lock_bh(&recent_lock); |
| 491 | |
| 492 | for (st->bucket = 0; st->bucket < ip_list_hash_size; st->bucket++) |
| 493 | list_for_each_entry(e, &t->iphash[st->bucket], list) |
| 494 | if (p-- == 0) |
| 495 | return e; |
| 496 | return NULL; |
| 497 | } |
| 498 | |
| 499 | static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
| 500 | { |
| 501 | struct recent_iter_state *st = seq->private; |
| 502 | const struct recent_table *t = st->table; |
| 503 | const struct recent_entry *e = v; |
| 504 | const struct list_head *head = e->list.next; |
| 505 | |
| 506 | while (head == &t->iphash[st->bucket]) { |
| 507 | if (++st->bucket >= ip_list_hash_size) |
| 508 | return NULL; |
| 509 | head = t->iphash[st->bucket].next; |
| 510 | } |
| 511 | (*pos)++; |
| 512 | return list_entry(head, struct recent_entry, list); |
| 513 | } |
| 514 | |
| 515 | static void recent_seq_stop(struct seq_file *s, void *v) |
| 516 | __releases(recent_lock) |
| 517 | { |
| 518 | spin_unlock_bh(&recent_lock); |
| 519 | } |
| 520 | |
| 521 | static int recent_seq_show(struct seq_file *seq, void *v) |
| 522 | { |
| 523 | const struct recent_entry *e = v; |
| 524 | struct recent_iter_state *st = seq->private; |
| 525 | const struct recent_table *t = st->table; |
| 526 | unsigned int i; |
| 527 | |
| 528 | i = (e->index - 1) & t->nstamps_max_mask; |
| 529 | |
| 530 | if (e->family == NFPROTO_IPV4) |
| 531 | seq_printf(seq, "src=%pI4 ttl: %u last_seen: %lu oldest_pkt: %u", |
| 532 | &e->addr.ip, e->ttl, e->stamps[i], e->index); |
| 533 | else |
| 534 | seq_printf(seq, "src=%pI6 ttl: %u last_seen: %lu oldest_pkt: %u", |
| 535 | &e->addr.in6, e->ttl, e->stamps[i], e->index); |
| 536 | for (i = 0; i < e->nstamps; i++) |
| 537 | seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]); |
| 538 | seq_printf(seq, "\n"); |
| 539 | return 0; |
| 540 | } |
| 541 | |
| 542 | static const struct seq_operations recent_seq_ops = { |
| 543 | .start = recent_seq_start, |
| 544 | .next = recent_seq_next, |
| 545 | .stop = recent_seq_stop, |
| 546 | .show = recent_seq_show, |
| 547 | }; |
| 548 | |
| 549 | static int recent_seq_open(struct inode *inode, struct file *file) |
| 550 | { |
| 551 | struct recent_iter_state *st; |
| 552 | |
| 553 | st = __seq_open_private(file, &recent_seq_ops, sizeof(*st)); |
| 554 | if (st == NULL) |
| 555 | return -ENOMEM; |
| 556 | |
| 557 | st->table = PDE_DATA(inode); |
| 558 | return 0; |
| 559 | } |
| 560 | |
| 561 | static ssize_t |
| 562 | recent_mt_proc_write(struct file *file, const char __user *input, |
| 563 | size_t size, loff_t *loff) |
| 564 | { |
| 565 | struct recent_table *t = PDE_DATA(file_inode(file)); |
| 566 | struct recent_entry *e; |
| 567 | char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")]; |
| 568 | const char *c = buf; |
| 569 | union nf_inet_addr addr = {}; |
| 570 | u_int16_t family; |
| 571 | bool add, succ; |
| 572 | |
| 573 | if (size == 0) |
| 574 | return 0; |
| 575 | if (size > sizeof(buf)) |
| 576 | size = sizeof(buf); |
| 577 | if (copy_from_user(buf, input, size) != 0) |
| 578 | return -EFAULT; |
| 579 | |
| 580 | /* Strict protocol! */ |
| 581 | if (*loff != 0) |
| 582 | return -ESPIPE; |
| 583 | switch (*c) { |
| 584 | case '/': /* flush table */ |
| 585 | spin_lock_bh(&recent_lock); |
| 586 | recent_table_flush(t); |
| 587 | spin_unlock_bh(&recent_lock); |
| 588 | return size; |
| 589 | case '-': /* remove address */ |
| 590 | add = false; |
| 591 | break; |
| 592 | case '+': /* add address */ |
| 593 | add = true; |
| 594 | break; |
| 595 | default: |
| 596 | pr_info("Need \"+ip\", \"-ip\" or \"/\"\n"); |
| 597 | return -EINVAL; |
| 598 | } |
| 599 | |
| 600 | ++c; |
| 601 | --size; |
| 602 | if (strnchr(c, size, ':') != NULL) { |
| 603 | family = NFPROTO_IPV6; |
| 604 | succ = in6_pton(c, size, (void *)&addr, '\n', NULL); |
| 605 | } else { |
| 606 | family = NFPROTO_IPV4; |
| 607 | succ = in4_pton(c, size, (void *)&addr, '\n', NULL); |
| 608 | } |
| 609 | |
| 610 | if (!succ) { |
| 611 | pr_info("illegal address written to procfs\n"); |
| 612 | return -EINVAL; |
| 613 | } |
| 614 | |
| 615 | spin_lock_bh(&recent_lock); |
| 616 | e = recent_entry_lookup(t, &addr, family, 0); |
| 617 | if (e == NULL) { |
| 618 | if (add) |
| 619 | recent_entry_init(t, &addr, family, 0); |
| 620 | } else { |
| 621 | if (add) |
| 622 | recent_entry_update(t, e); |
| 623 | else |
| 624 | recent_entry_remove(t, e); |
| 625 | } |
| 626 | spin_unlock_bh(&recent_lock); |
| 627 | /* Note we removed one above */ |
| 628 | *loff += size + 1; |
| 629 | return size + 1; |
| 630 | } |
| 631 | |
| 632 | static const struct file_operations recent_mt_fops = { |
| 633 | .open = recent_seq_open, |
| 634 | .read = seq_read, |
| 635 | .write = recent_mt_proc_write, |
| 636 | .release = seq_release_private, |
| 637 | .owner = THIS_MODULE, |
| 638 | .llseek = seq_lseek, |
| 639 | }; |
| 640 | |
| 641 | static int __net_init recent_proc_net_init(struct net *net) |
| 642 | { |
| 643 | struct recent_net *recent_net = recent_pernet(net); |
| 644 | |
| 645 | recent_net->xt_recent = proc_mkdir("xt_recent", net->proc_net); |
| 646 | if (!recent_net->xt_recent) |
| 647 | return -ENOMEM; |
| 648 | return 0; |
| 649 | } |
| 650 | |
| 651 | static void __net_exit recent_proc_net_exit(struct net *net) |
| 652 | { |
| 653 | struct recent_net *recent_net = recent_pernet(net); |
| 654 | struct recent_table *t; |
| 655 | |
| 656 | /* recent_net_exit() is called before recent_mt_destroy(). Make sure |
| 657 | * that the parent xt_recent proc entry is is empty before trying to |
| 658 | * remove it. |
| 659 | */ |
| 660 | spin_lock_bh(&recent_lock); |
| 661 | list_for_each_entry(t, &recent_net->tables, list) |
| 662 | remove_proc_entry(t->name, recent_net->xt_recent); |
| 663 | |
| 664 | recent_net->xt_recent = NULL; |
| 665 | spin_unlock_bh(&recent_lock); |
| 666 | |
| 667 | remove_proc_entry("xt_recent", net->proc_net); |
| 668 | } |
| 669 | #else |
| 670 | static inline int recent_proc_net_init(struct net *net) |
| 671 | { |
| 672 | return 0; |
| 673 | } |
| 674 | |
| 675 | static inline void recent_proc_net_exit(struct net *net) |
| 676 | { |
| 677 | } |
| 678 | #endif /* CONFIG_PROC_FS */ |
| 679 | |
| 680 | static int __net_init recent_net_init(struct net *net) |
| 681 | { |
| 682 | struct recent_net *recent_net = recent_pernet(net); |
| 683 | |
| 684 | INIT_LIST_HEAD(&recent_net->tables); |
| 685 | return recent_proc_net_init(net); |
| 686 | } |
| 687 | |
| 688 | static void __net_exit recent_net_exit(struct net *net) |
| 689 | { |
| 690 | recent_proc_net_exit(net); |
| 691 | } |
| 692 | |
| 693 | static struct pernet_operations recent_net_ops = { |
| 694 | .init = recent_net_init, |
| 695 | .exit = recent_net_exit, |
| 696 | .id = &recent_net_id, |
| 697 | .size = sizeof(struct recent_net), |
| 698 | }; |
| 699 | |
| 700 | static struct xt_match recent_mt_reg[] __read_mostly = { |
| 701 | { |
| 702 | .name = "recent", |
| 703 | .revision = 0, |
| 704 | .family = NFPROTO_IPV4, |
| 705 | .match = recent_mt, |
| 706 | .matchsize = sizeof(struct xt_recent_mtinfo), |
| 707 | .checkentry = recent_mt_check_v0, |
| 708 | .destroy = recent_mt_destroy, |
| 709 | .me = THIS_MODULE, |
| 710 | }, |
| 711 | { |
| 712 | .name = "recent", |
| 713 | .revision = 0, |
| 714 | .family = NFPROTO_IPV6, |
| 715 | .match = recent_mt, |
| 716 | .matchsize = sizeof(struct xt_recent_mtinfo), |
| 717 | .checkentry = recent_mt_check_v0, |
| 718 | .destroy = recent_mt_destroy, |
| 719 | .me = THIS_MODULE, |
| 720 | }, |
| 721 | { |
| 722 | .name = "recent", |
| 723 | .revision = 1, |
| 724 | .family = NFPROTO_IPV4, |
| 725 | .match = recent_mt, |
| 726 | .matchsize = sizeof(struct xt_recent_mtinfo_v1), |
| 727 | .checkentry = recent_mt_check_v1, |
| 728 | .destroy = recent_mt_destroy, |
| 729 | .me = THIS_MODULE, |
| 730 | }, |
| 731 | { |
| 732 | .name = "recent", |
| 733 | .revision = 1, |
| 734 | .family = NFPROTO_IPV6, |
| 735 | .match = recent_mt, |
| 736 | .matchsize = sizeof(struct xt_recent_mtinfo_v1), |
| 737 | .checkentry = recent_mt_check_v1, |
| 738 | .destroy = recent_mt_destroy, |
| 739 | .me = THIS_MODULE, |
| 740 | } |
| 741 | }; |
| 742 | |
| 743 | static int __init recent_mt_init(void) |
| 744 | { |
| 745 | int err; |
| 746 | |
| 747 | BUILD_BUG_ON_NOT_POWER_OF_2(XT_RECENT_MAX_NSTAMPS); |
| 748 | |
| 749 | if (!ip_list_tot || ip_pkt_list_tot >= XT_RECENT_MAX_NSTAMPS) |
| 750 | return -EINVAL; |
| 751 | ip_list_hash_size = 1 << fls(ip_list_tot); |
| 752 | |
| 753 | err = register_pernet_subsys(&recent_net_ops); |
| 754 | if (err) |
| 755 | return err; |
| 756 | err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg)); |
| 757 | if (err) |
| 758 | unregister_pernet_subsys(&recent_net_ops); |
| 759 | return err; |
| 760 | } |
| 761 | |
| 762 | static void __exit recent_mt_exit(void) |
| 763 | { |
| 764 | xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg)); |
| 765 | unregister_pernet_subsys(&recent_net_ops); |
| 766 | } |
| 767 | |
| 768 | module_init(recent_mt_init); |
| 769 | module_exit(recent_mt_exit); |