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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
[linux-2.6.git] / net / ipv4 / netfilter / ipt_CLUSTERIP.c
blobdb8d22db425f6917b23d8d31661905ab58d3ef2d
1 /* Cluster IP hashmark target
2 * (C) 2003-2004 by Harald Welte <laforge@netfilter.org>
3 * based on ideas of Fabio Olive Leite <olive@unixforge.org>
4 *
5 * Development of this code funded by SuSE Linux AG, http://www.suse.com/
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 */
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 #include <linux/module.h>
14 #include <linux/proc_fs.h>
15 #include <linux/jhash.h>
16 #include <linux/bitops.h>
17 #include <linux/skbuff.h>
18 #include <linux/slab.h>
19 #include <linux/ip.h>
20 #include <linux/tcp.h>
21 #include <linux/udp.h>
22 #include <linux/icmp.h>
23 #include <linux/if_arp.h>
24 #include <linux/seq_file.h>
25 #include <linux/netfilter_arp.h>
26 #include <linux/netfilter/x_tables.h>
27 #include <linux/netfilter_ipv4/ip_tables.h>
28 #include <linux/netfilter_ipv4/ipt_CLUSTERIP.h>
29 #include <net/netfilter/nf_conntrack.h>
30 #include <net/net_namespace.h>
31 #include <net/checksum.h>
32 #include <net/ip.h>
33
34 #define CLUSTERIP_VERSION "0.8"
35
36 MODULE_LICENSE("GPL");
37 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
38 MODULE_DESCRIPTION("Xtables: CLUSTERIP target");
39
40 struct clusterip_config {
41 struct list_head list; /* list of all configs */
42 atomic_t refcount; /* reference count */
43 atomic_t entries; /* number of entries/rules
44 * referencing us */
45
46 __be32 clusterip; /* the IP address */
47 u_int8_t clustermac[ETH_ALEN]; /* the MAC address */
48 struct net_device *dev; /* device */
49 u_int16_t num_total_nodes; /* total number of nodes */
50 unsigned long local_nodes; /* node number array */
51
52 #ifdef CONFIG_PROC_FS
53 struct proc_dir_entry *pde; /* proc dir entry */
54 #endif
55 enum clusterip_hashmode hash_mode; /* which hashing mode */
56 u_int32_t hash_initval; /* hash initialization */
57 struct rcu_head rcu;
58 };
59
60 static LIST_HEAD(clusterip_configs);
61
62 /* clusterip_lock protects the clusterip_configs list */
63 static DEFINE_SPINLOCK(clusterip_lock);
64
65 #ifdef CONFIG_PROC_FS
66 static const struct file_operations clusterip_proc_fops;
67 static struct proc_dir_entry *clusterip_procdir;
68 #endif
69
70 static inline void
71 clusterip_config_get(struct clusterip_config *c)
72 {
73 atomic_inc(&c->refcount);
74 }
75
76
77 static void clusterip_config_rcu_free(struct rcu_head *head)
78 {
79 kfree(container_of(head, struct clusterip_config, rcu));
80 }
81
82 static inline void
83 clusterip_config_put(struct clusterip_config *c)
84 {
85 if (atomic_dec_and_test(&c->refcount))
86 call_rcu_bh(&c->rcu, clusterip_config_rcu_free);
87 }
88
89 /* decrease the count of entries using/referencing this config. If last
90 * entry(rule) is removed, remove the config from lists, but don't free it
91 * yet, since proc-files could still be holding references */
92 static inline void
93 clusterip_config_entry_put(struct clusterip_config *c)
94 {
95 local_bh_disable();
96 if (atomic_dec_and_lock(&c->entries, &clusterip_lock)) {
97 list_del_rcu(&c->list);
98 spin_unlock(&clusterip_lock);
99 local_bh_enable();
100
101 dev_mc_del(c->dev, c->clustermac);
102 dev_put(c->dev);
103
104 /* In case anyone still accesses the file, the open/close
105 * functions are also incrementing the refcount on their own,
106 * so it's safe to remove the entry even if it's in use. */
107 #ifdef CONFIG_PROC_FS
108 remove_proc_entry(c->pde->name, c->pde->parent);
109 #endif
110 return;
111 }
112 local_bh_enable();
113 }
114
115 static struct clusterip_config *
116 __clusterip_config_find(__be32 clusterip)
117 {
118 struct clusterip_config *c;
119
120 list_for_each_entry_rcu(c, &clusterip_configs, list) {
121 if (c->clusterip == clusterip)
122 return c;
123 }
124
125 return NULL;
126 }
127
128 static inline struct clusterip_config *
129 clusterip_config_find_get(__be32 clusterip, int entry)
130 {
131 struct clusterip_config *c;
132
133 rcu_read_lock_bh();
134 c = __clusterip_config_find(clusterip);
135 if (c) {
136 if (unlikely(!atomic_inc_not_zero(&c->refcount)))
137 c = NULL;
138 else if (entry)
139 atomic_inc(&c->entries);
140 }
141 rcu_read_unlock_bh();
142
143 return c;
144 }
145
146 static void
147 clusterip_config_init_nodelist(struct clusterip_config *c,
148 const struct ipt_clusterip_tgt_info *i)
149 {
150 int n;
151
152 for (n = 0; n < i->num_local_nodes; n++)
153 set_bit(i->local_nodes[n] - 1, &c->local_nodes);
154 }
155
156 static struct clusterip_config *
157 clusterip_config_init(const struct ipt_clusterip_tgt_info *i, __be32 ip,
158 struct net_device *dev)
159 {
160 struct clusterip_config *c;
161
162 c = kzalloc(sizeof(*c), GFP_ATOMIC);
163 if (!c)
164 return NULL;
165
166 c->dev = dev;
167 c->clusterip = ip;
168 memcpy(&c->clustermac, &i->clustermac, ETH_ALEN);
169 c->num_total_nodes = i->num_total_nodes;
170 clusterip_config_init_nodelist(c, i);
171 c->hash_mode = i->hash_mode;
172 c->hash_initval = i->hash_initval;
173 atomic_set(&c->refcount, 1);
174 atomic_set(&c->entries, 1);
175
176 #ifdef CONFIG_PROC_FS
177 {
178 char buffer[16];
179
180 /* create proc dir entry */
181 sprintf(buffer, "%pI4", &ip);
182 c->pde = proc_create_data(buffer, S_IWUSR|S_IRUSR,
183 clusterip_procdir,
184 &clusterip_proc_fops, c);
185 if (!c->pde) {
186 kfree(c);
187 return NULL;
188 }
189 }
190 #endif
191
192 spin_lock_bh(&clusterip_lock);
193 list_add_rcu(&c->list, &clusterip_configs);
194 spin_unlock_bh(&clusterip_lock);
195
196 return c;
197 }
198
199 #ifdef CONFIG_PROC_FS
200 static int
201 clusterip_add_node(struct clusterip_config *c, u_int16_t nodenum)
202 {
203
204 if (nodenum == 0 ||
205 nodenum > c->num_total_nodes)
206 return 1;
207
208 /* check if we already have this number in our bitfield */
209 if (test_and_set_bit(nodenum - 1, &c->local_nodes))
210 return 1;
211
212 return 0;
213 }
214
215 static bool
216 clusterip_del_node(struct clusterip_config *c, u_int16_t nodenum)
217 {
218 if (nodenum == 0 ||
219 nodenum > c->num_total_nodes)
220 return true;
221
222 if (test_and_clear_bit(nodenum - 1, &c->local_nodes))
223 return false;
224
225 return true;
226 }
227 #endif
228
229 static inline u_int32_t
230 clusterip_hashfn(const struct sk_buff *skb,
231 const struct clusterip_config *config)
232 {
233 const struct iphdr *iph = ip_hdr(skb);
234 unsigned long hashval;
235 u_int16_t sport = 0, dport = 0;
236 int poff;
237
238 poff = proto_ports_offset(iph->protocol);
239 if (poff >= 0) {
240 const u_int16_t *ports;
241 u16 _ports[2];
242
243 ports = skb_header_pointer(skb, iph->ihl * 4 + poff, 4, _ports);
244 if (ports) {
245 sport = ports[0];
246 dport = ports[1];
247 }
248 } else {
249 if (net_ratelimit())
250 pr_info("unknown protocol %u\n", iph->protocol);
251 }
252
253 switch (config->hash_mode) {
254 case CLUSTERIP_HASHMODE_SIP:
255 hashval = jhash_1word(ntohl(iph->saddr),
256 config->hash_initval);
257 break;
258 case CLUSTERIP_HASHMODE_SIP_SPT:
259 hashval = jhash_2words(ntohl(iph->saddr), sport,
260 config->hash_initval);
261 break;
262 case CLUSTERIP_HASHMODE_SIP_SPT_DPT:
263 hashval = jhash_3words(ntohl(iph->saddr), sport, dport,
264 config->hash_initval);
265 break;
266 default:
267 /* to make gcc happy */
268 hashval = 0;
269 /* This cannot happen, unless the check function wasn't called
270 * at rule load time */
271 pr_info("unknown mode %u\n", config->hash_mode);
272 BUG();
273 break;
274 }
275
276 /* node numbers are 1..n, not 0..n */
277 return (((u64)hashval * config->num_total_nodes) >> 32) + 1;
278 }
279
280 static inline int
281 clusterip_responsible(const struct clusterip_config *config, u_int32_t hash)
282 {
283 return test_bit(hash - 1, &config->local_nodes);
284 }
285
286 /***********************************************************************
287 * IPTABLES TARGET
288 ***********************************************************************/
289
290 static unsigned int
291 clusterip_tg(struct sk_buff *skb, const struct xt_action_param *par)
292 {
293 const struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
294 struct nf_conn *ct;
295 enum ip_conntrack_info ctinfo;
296 u_int32_t hash;
297
298 /* don't need to clusterip_config_get() here, since refcount
299 * is only decremented by destroy() - and ip_tables guarantees
300 * that the ->target() function isn't called after ->destroy() */
301
302 ct = nf_ct_get(skb, &ctinfo);
303 if (ct == NULL)
304 return NF_DROP;
305
306 /* special case: ICMP error handling. conntrack distinguishes between
307 * error messages (RELATED) and information requests (see below) */
308 if (ip_hdr(skb)->protocol == IPPROTO_ICMP &&
309 (ctinfo == IP_CT_RELATED ||
310 ctinfo == IP_CT_RELATED_REPLY))
311 return XT_CONTINUE;
312
313 /* ip_conntrack_icmp guarantees us that we only have ICMP_ECHO,
314 * TIMESTAMP, INFO_REQUEST or ADDRESS type icmp packets from here
315 * on, which all have an ID field [relevant for hashing]. */
316
317 hash = clusterip_hashfn(skb, cipinfo->config);
318
319 switch (ctinfo) {
320 case IP_CT_NEW:
321 ct->mark = hash;
322 break;
323 case IP_CT_RELATED:
324 case IP_CT_RELATED_REPLY:
325 /* FIXME: we don't handle expectations at the moment.
326 * They can arrive on a different node than
327 * the master connection (e.g. FTP passive mode) */
328 case IP_CT_ESTABLISHED:
329 case IP_CT_ESTABLISHED_REPLY:
330 break;
331 default: /* Prevent gcc warnings */
332 break;
333 }
334
335 #ifdef DEBUG
336 nf_ct_dump_tuple_ip(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
337 #endif
338 pr_debug("hash=%u ct_hash=%u ", hash, ct->mark);
339 if (!clusterip_responsible(cipinfo->config, hash)) {
340 pr_debug("not responsible\n");
341 return NF_DROP;
342 }
343 pr_debug("responsible\n");
344
345 /* despite being received via linklayer multicast, this is
346 * actually a unicast IP packet. TCP doesn't like PACKET_MULTICAST */
347 skb->pkt_type = PACKET_HOST;
348
349 return XT_CONTINUE;
350 }
351
352 static int clusterip_tg_check(const struct xt_tgchk_param *par)
353 {
354 struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
355 const struct ipt_entry *e = par->entryinfo;
356 struct clusterip_config *config;
357 int ret;
358
359 if (cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP &&
360 cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT &&
361 cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT_DPT) {
362 pr_info("unknown mode %u\n", cipinfo->hash_mode);
363 return -EINVAL;
364
365 }
366 if (e->ip.dmsk.s_addr != htonl(0xffffffff) ||
367 e->ip.dst.s_addr == 0) {
368 pr_info("Please specify destination IP\n");
369 return -EINVAL;
370 }
371
372 /* FIXME: further sanity checks */
373
374 config = clusterip_config_find_get(e->ip.dst.s_addr, 1);
375 if (!config) {
376 if (!(cipinfo->flags & CLUSTERIP_FLAG_NEW)) {
377 pr_info("no config found for %pI4, need 'new'\n",
378 &e->ip.dst.s_addr);
379 return -EINVAL;
380 } else {
381 struct net_device *dev;
382
383 if (e->ip.iniface[0] == '\0') {
384 pr_info("Please specify an interface name\n");
385 return -EINVAL;
386 }
387
388 dev = dev_get_by_name(&init_net, e->ip.iniface);
389 if (!dev) {
390 pr_info("no such interface %s\n",
391 e->ip.iniface);
392 return -ENOENT;
393 }
394
395 config = clusterip_config_init(cipinfo,
396 e->ip.dst.s_addr, dev);
397 if (!config) {
398 pr_info("cannot allocate config\n");
399 dev_put(dev);
400 return -ENOMEM;
401 }
402 dev_mc_add(config->dev, config->clustermac);
403 }
404 }
405 cipinfo->config = config;
406
407 ret = nf_ct_l3proto_try_module_get(par->family);
408 if (ret < 0)
409 pr_info("cannot load conntrack support for proto=%u\n",
410 par->family);
411 return ret;
412 }
413
414 /* drop reference count of cluster config when rule is deleted */
415 static void clusterip_tg_destroy(const struct xt_tgdtor_param *par)
416 {
417 const struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
418
419 /* if no more entries are referencing the config, remove it
420 * from the list and destroy the proc entry */
421 clusterip_config_entry_put(cipinfo->config);
422
423 clusterip_config_put(cipinfo->config);
424
425 nf_ct_l3proto_module_put(par->family);
426 }
427
428 #ifdef CONFIG_COMPAT
429 struct compat_ipt_clusterip_tgt_info
430 {
431 u_int32_t flags;
432 u_int8_t clustermac[6];
433 u_int16_t num_total_nodes;
434 u_int16_t num_local_nodes;
435 u_int16_t local_nodes[CLUSTERIP_MAX_NODES];
436 u_int32_t hash_mode;
437 u_int32_t hash_initval;
438 compat_uptr_t config;
439 };
440 #endif /* CONFIG_COMPAT */
441
442 static struct xt_target clusterip_tg_reg __read_mostly = {
443 .name = "CLUSTERIP",
444 .family = NFPROTO_IPV4,
445 .target = clusterip_tg,
446 .checkentry = clusterip_tg_check,
447 .destroy = clusterip_tg_destroy,
448 .targetsize = sizeof(struct ipt_clusterip_tgt_info),
449 #ifdef CONFIG_COMPAT
450 .compatsize = sizeof(struct compat_ipt_clusterip_tgt_info),
451 #endif /* CONFIG_COMPAT */
452 .me = THIS_MODULE
453 };
454
455
456 /***********************************************************************
457 * ARP MANGLING CODE
458 ***********************************************************************/
459
460 /* hardcoded for 48bit ethernet and 32bit ipv4 addresses */
461 struct arp_payload {
462 u_int8_t src_hw[ETH_ALEN];
463 __be32 src_ip;
464 u_int8_t dst_hw[ETH_ALEN];
465 __be32 dst_ip;
466 } __packed;
467
468 #ifdef DEBUG
469 static void arp_print(struct arp_payload *payload)
470 {
471 #define HBUFFERLEN 30
472 char hbuffer[HBUFFERLEN];
473 int j,k;
474
475 for (k=0, j=0; k < HBUFFERLEN-3 && j < ETH_ALEN; j++) {
476 hbuffer[k++] = hex_asc_hi(payload->src_hw[j]);
477 hbuffer[k++] = hex_asc_lo(payload->src_hw[j]);
478 hbuffer[k++]=':';
479 }
480 hbuffer[--k]='\0';
481
482 pr_debug("src %pI4@%s, dst %pI4\n",
483 &payload->src_ip, hbuffer, &payload->dst_ip);
484 }
485 #endif
486
487 static unsigned int
488 arp_mangle(unsigned int hook,
489 struct sk_buff *skb,
490 const struct net_device *in,
491 const struct net_device *out,
492 int (*okfn)(struct sk_buff *))
493 {
494 struct arphdr *arp = arp_hdr(skb);
495 struct arp_payload *payload;
496 struct clusterip_config *c;
497
498 /* we don't care about non-ethernet and non-ipv4 ARP */
499 if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
500 arp->ar_pro != htons(ETH_P_IP) ||
501 arp->ar_pln != 4 || arp->ar_hln != ETH_ALEN)
502 return NF_ACCEPT;
503
504 /* we only want to mangle arp requests and replies */
505 if (arp->ar_op != htons(ARPOP_REPLY) &&
506 arp->ar_op != htons(ARPOP_REQUEST))
507 return NF_ACCEPT;
508
509 payload = (void *)(arp+1);
510
511 /* if there is no clusterip configuration for the arp reply's
512 * source ip, we don't want to mangle it */
513 c = clusterip_config_find_get(payload->src_ip, 0);
514 if (!c)
515 return NF_ACCEPT;
516
517 /* normally the linux kernel always replies to arp queries of
518 * addresses on different interfacs. However, in the CLUSTERIP case
519 * this wouldn't work, since we didn't subscribe the mcast group on
520 * other interfaces */
521 if (c->dev != out) {
522 pr_debug("not mangling arp reply on different "
523 "interface: cip'%s'-skb'%s'\n",
524 c->dev->name, out->name);
525 clusterip_config_put(c);
526 return NF_ACCEPT;
527 }
528
529 /* mangle reply hardware address */
530 memcpy(payload->src_hw, c->clustermac, arp->ar_hln);
531
532 #ifdef DEBUG
533 pr_debug("mangled arp reply: ");
534 arp_print(payload);
535 #endif
536
537 clusterip_config_put(c);
538
539 return NF_ACCEPT;
540 }
541
542 static struct nf_hook_ops cip_arp_ops __read_mostly = {
543 .hook = arp_mangle,
544 .pf = NFPROTO_ARP,
545 .hooknum = NF_ARP_OUT,
546 .priority = -1
547 };
548
549 /***********************************************************************
550 * PROC DIR HANDLING
551 ***********************************************************************/
552
553 #ifdef CONFIG_PROC_FS
554
555 struct clusterip_seq_position {
556 unsigned int pos; /* position */
557 unsigned int weight; /* number of bits set == size */
558 unsigned int bit; /* current bit */
559 unsigned long val; /* current value */
560 };
561
562 static void *clusterip_seq_start(struct seq_file *s, loff_t *pos)
563 {
564 struct clusterip_config *c = s->private;
565 unsigned int weight;
566 u_int32_t local_nodes;
567 struct clusterip_seq_position *idx;
568
569 /* FIXME: possible race */
570 local_nodes = c->local_nodes;
571 weight = hweight32(local_nodes);
572 if (*pos >= weight)
573 return NULL;
574
575 idx = kmalloc(sizeof(struct clusterip_seq_position), GFP_KERNEL);
576 if (!idx)
577 return ERR_PTR(-ENOMEM);
578
579 idx->pos = *pos;
580 idx->weight = weight;
581 idx->bit = ffs(local_nodes);
582 idx->val = local_nodes;
583 clear_bit(idx->bit - 1, &idx->val);
584
585 return idx;
586 }
587
588 static void *clusterip_seq_next(struct seq_file *s, void *v, loff_t *pos)
589 {
590 struct clusterip_seq_position *idx = v;
591
592 *pos = ++idx->pos;
593 if (*pos >= idx->weight) {
594 kfree(v);
595 return NULL;
596 }
597 idx->bit = ffs(idx->val);
598 clear_bit(idx->bit - 1, &idx->val);
599 return idx;
600 }
601
602 static void clusterip_seq_stop(struct seq_file *s, void *v)
603 {
604 if (!IS_ERR(v))
605 kfree(v);
606 }
607
608 static int clusterip_seq_show(struct seq_file *s, void *v)
609 {
610 struct clusterip_seq_position *idx = v;
611
612 if (idx->pos != 0)
613 seq_putc(s, ',');
614
615 seq_printf(s, "%u", idx->bit);
616
617 if (idx->pos == idx->weight - 1)
618 seq_putc(s, '\n');
619
620 return 0;
621 }
622
623 static const struct seq_operations clusterip_seq_ops = {
624 .start = clusterip_seq_start,
625 .next = clusterip_seq_next,
626 .stop = clusterip_seq_stop,
627 .show = clusterip_seq_show,
628 };
629
630 static int clusterip_proc_open(struct inode *inode, struct file *file)
631 {
632 int ret = seq_open(file, &clusterip_seq_ops);
633
634 if (!ret) {
635 struct seq_file *sf = file->private_data;
636 struct clusterip_config *c = PDE(inode)->data;
637
638 sf->private = c;
639
640 clusterip_config_get(c);
641 }
642
643 return ret;
644 }
645
646 static int clusterip_proc_release(struct inode *inode, struct file *file)
647 {
648 struct clusterip_config *c = PDE(inode)->data;
649 int ret;
650
651 ret = seq_release(inode, file);
652
653 if (!ret)
654 clusterip_config_put(c);
655
656 return ret;
657 }
658
659 static ssize_t clusterip_proc_write(struct file *file, const char __user *input,
660 size_t size, loff_t *ofs)
661 {
662 struct clusterip_config *c = PDE(file->f_path.dentry->d_inode)->data;
663 #define PROC_WRITELEN 10
664 char buffer[PROC_WRITELEN+1];
665 unsigned long nodenum;
666
667 if (size > PROC_WRITELEN)
668 return -EIO;
669 if (copy_from_user(buffer, input, size))
670 return -EFAULT;
671 buffer[size] = 0;
672
673 if (*buffer == '+') {
674 nodenum = simple_strtoul(buffer+1, NULL, 10);
675 if (clusterip_add_node(c, nodenum))
676 return -ENOMEM;
677 } else if (*buffer == '-') {
678 nodenum = simple_strtoul(buffer+1, NULL,10);
679 if (clusterip_del_node(c, nodenum))
680 return -ENOENT;
681 } else
682 return -EIO;
683
684 return size;
685 }
686
687 static const struct file_operations clusterip_proc_fops = {
688 .owner = THIS_MODULE,
689 .open = clusterip_proc_open,
690 .read = seq_read,
691 .write = clusterip_proc_write,
692 .llseek = seq_lseek,
693 .release = clusterip_proc_release,
694 };
695
696 #endif /* CONFIG_PROC_FS */
697
698 static int __init clusterip_tg_init(void)
699 {
700 int ret;
701
702 ret = xt_register_target(&clusterip_tg_reg);
703 if (ret < 0)
704 return ret;
705
706 ret = nf_register_hook(&cip_arp_ops);
707 if (ret < 0)
708 goto cleanup_target;
709
710 #ifdef CONFIG_PROC_FS
711 clusterip_procdir = proc_mkdir("ipt_CLUSTERIP", init_net.proc_net);
712 if (!clusterip_procdir) {
713 pr_err("Unable to proc dir entry\n");
714 ret = -ENOMEM;
715 goto cleanup_hook;
716 }
717 #endif /* CONFIG_PROC_FS */
718
719 pr_info("ClusterIP Version %s loaded successfully\n",
720 CLUSTERIP_VERSION);
721 return 0;
722
723 #ifdef CONFIG_PROC_FS
724 cleanup_hook:
725 nf_unregister_hook(&cip_arp_ops);
726 #endif /* CONFIG_PROC_FS */
727 cleanup_target:
728 xt_unregister_target(&clusterip_tg_reg);
729 return ret;
730 }
731
732 static void __exit clusterip_tg_exit(void)
733 {
734 pr_info("ClusterIP Version %s unloading\n", CLUSTERIP_VERSION);
735 #ifdef CONFIG_PROC_FS
736 remove_proc_entry(clusterip_procdir->name, clusterip_procdir->parent);
737 #endif
738 nf_unregister_hook(&cip_arp_ops);
739 xt_unregister_target(&clusterip_tg_reg);
740
741 /* Wait for completion of call_rcu_bh()'s (clusterip_config_rcu_free) */
742 rcu_barrier_bh();
743 }
744
745 module_init(clusterip_tg_init);
746 module_exit(clusterip_tg_exit);
Linus' kernel tree