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[mirror_ubuntu-bionic-kernel.git] / net / ipv4 / netfilter / ipt_CLUSTERIP.c
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/refcount.h>
26 #include <linux/netfilter_arp.h>
27 #include <linux/netfilter/x_tables.h>
28 #include <linux/netfilter_ipv4/ip_tables.h>
29 #include <linux/netfilter_ipv4/ipt_CLUSTERIP.h>
30 #include <net/netfilter/nf_conntrack.h>
31 #include <net/net_namespace.h>
32 #include <net/netns/generic.h>
33 #include <net/checksum.h>
34 #include <net/ip.h>
35
36 #define CLUSTERIP_VERSION "0.8"
37
38 MODULE_LICENSE("GPL");
39 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
40 MODULE_DESCRIPTION("Xtables: CLUSTERIP target");
41
42 struct clusterip_config {
43 struct list_head list; /* list of all configs */
44 refcount_t refcount; /* reference count */
45 refcount_t entries; /* number of entries/rules
46 * referencing us */
47
48 __be32 clusterip; /* the IP address */
49 u_int8_t clustermac[ETH_ALEN]; /* the MAC address */
50 int ifindex; /* device ifindex */
51 u_int16_t num_total_nodes; /* total number of nodes */
52 unsigned long local_nodes; /* node number array */
53
54 #ifdef CONFIG_PROC_FS
55 struct proc_dir_entry *pde; /* proc dir entry */
56 #endif
57 enum clusterip_hashmode hash_mode; /* which hashing mode */
58 u_int32_t hash_initval; /* hash initialization */
59 struct rcu_head rcu; /* for call_rcu_bh */
60 struct net *net; /* netns for pernet list */
61 char ifname[IFNAMSIZ]; /* device ifname */
62 };
63
64 #ifdef CONFIG_PROC_FS
65 static const struct file_operations clusterip_proc_fops;
66 #endif
67
68 struct clusterip_net {
69 struct list_head configs;
70 /* lock protects the configs list */
71 spinlock_t lock;
72
73 #ifdef CONFIG_PROC_FS
74 struct proc_dir_entry *procdir;
75 /* mutex protects the config->pde*/
76 struct mutex mutex;
77 #endif
78 };
79
80 static unsigned int clusterip_net_id __read_mostly;
81 static inline struct clusterip_net *clusterip_pernet(struct net *net)
82 {
83 return net_generic(net, clusterip_net_id);
84 }
85
86 static inline void
87 clusterip_config_get(struct clusterip_config *c)
88 {
89 refcount_inc(&c->refcount);
90 }
91
92 static void clusterip_config_rcu_free(struct rcu_head *head)
93 {
94 struct clusterip_config *config;
95 struct net_device *dev;
96
97 config = container_of(head, struct clusterip_config, rcu);
98 dev = dev_get_by_name(config->net, config->ifname);
99 if (dev) {
100 dev_mc_del(dev, config->clustermac);
101 dev_put(dev);
102 }
103 kfree(config);
104 }
105
106 static inline void
107 clusterip_config_put(struct clusterip_config *c)
108 {
109 if (refcount_dec_and_test(&c->refcount))
110 call_rcu_bh(&c->rcu, clusterip_config_rcu_free);
111 }
112
113 /* decrease the count of entries using/referencing this config. If last
114 * entry(rule) is removed, remove the config from lists, but don't free it
115 * yet, since proc-files could still be holding references */
116 static inline void
117 clusterip_config_entry_put(struct clusterip_config *c)
118 {
119 struct clusterip_net *cn = clusterip_pernet(c->net);
120
121 local_bh_disable();
122 if (refcount_dec_and_lock(&c->entries, &cn->lock)) {
123 list_del_rcu(&c->list);
124 spin_unlock(&cn->lock);
125 local_bh_enable();
126 /* In case anyone still accesses the file, the open/close
127 * functions are also incrementing the refcount on their own,
128 * so it's safe to remove the entry even if it's in use. */
129 #ifdef CONFIG_PROC_FS
130 mutex_lock(&cn->mutex);
131 if (cn->procdir)
132 proc_remove(c->pde);
133 mutex_unlock(&cn->mutex);
134 #endif
135 return;
136 }
137 local_bh_enable();
138 }
139
140 static struct clusterip_config *
141 __clusterip_config_find(struct net *net, __be32 clusterip)
142 {
143 struct clusterip_config *c;
144 struct clusterip_net *cn = clusterip_pernet(net);
145
146 list_for_each_entry_rcu(c, &cn->configs, list) {
147 if (c->clusterip == clusterip)
148 return c;
149 }
150
151 return NULL;
152 }
153
154 static inline struct clusterip_config *
155 clusterip_config_find_get(struct net *net, __be32 clusterip, int entry)
156 {
157 struct clusterip_config *c;
158
159 rcu_read_lock_bh();
160 c = __clusterip_config_find(net, clusterip);
161 if (c) {
162 #ifdef CONFIG_PROC_FS
163 if (!c->pde)
164 c = NULL;
165 else
166 #endif
167 if (unlikely(!refcount_inc_not_zero(&c->refcount)))
168 c = NULL;
169 else if (entry)
170 refcount_inc(&c->entries);
171 }
172 rcu_read_unlock_bh();
173
174 return c;
175 }
176
177 static void
178 clusterip_config_init_nodelist(struct clusterip_config *c,
179 const struct ipt_clusterip_tgt_info *i)
180 {
181 int n;
182
183 for (n = 0; n < i->num_local_nodes; n++)
184 set_bit(i->local_nodes[n] - 1, &c->local_nodes);
185 }
186
187 static int
188 clusterip_netdev_event(struct notifier_block *this, unsigned long event,
189 void *ptr)
190 {
191 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
192 struct net *net = dev_net(dev);
193 struct clusterip_net *cn = clusterip_pernet(net);
194 struct clusterip_config *c;
195
196 spin_lock_bh(&cn->lock);
197 list_for_each_entry_rcu(c, &cn->configs, list) {
198 switch (event) {
199 case NETDEV_REGISTER:
200 if (!strcmp(dev->name, c->ifname)) {
201 c->ifindex = dev->ifindex;
202 dev_mc_add(dev, c->clustermac);
203 }
204 break;
205 case NETDEV_UNREGISTER:
206 if (dev->ifindex == c->ifindex) {
207 dev_mc_del(dev, c->clustermac);
208 c->ifindex = -1;
209 }
210 break;
211 case NETDEV_CHANGENAME:
212 if (!strcmp(dev->name, c->ifname)) {
213 c->ifindex = dev->ifindex;
214 dev_mc_add(dev, c->clustermac);
215 } else if (dev->ifindex == c->ifindex) {
216 dev_mc_del(dev, c->clustermac);
217 c->ifindex = -1;
218 }
219 break;
220 }
221 }
222 spin_unlock_bh(&cn->lock);
223
224 return NOTIFY_DONE;
225 }
226
227 static struct clusterip_config *
228 clusterip_config_init(struct net *net, const struct ipt_clusterip_tgt_info *i,
229 __be32 ip, const char *iniface)
230 {
231 struct clusterip_net *cn = clusterip_pernet(net);
232 struct clusterip_config *c;
233 struct net_device *dev;
234 int err;
235
236 if (iniface[0] == '\0') {
237 pr_info("Please specify an interface name\n");
238 return ERR_PTR(-EINVAL);
239 }
240
241 c = kzalloc(sizeof(*c), GFP_ATOMIC);
242 if (!c)
243 return ERR_PTR(-ENOMEM);
244
245 dev = dev_get_by_name(net, iniface);
246 if (!dev) {
247 pr_info("no such interface %s\n", iniface);
248 kfree(c);
249 return ERR_PTR(-ENOENT);
250 }
251 c->ifindex = dev->ifindex;
252 strcpy(c->ifname, dev->name);
253 memcpy(&c->clustermac, &i->clustermac, ETH_ALEN);
254 dev_mc_add(dev, c->clustermac);
255 dev_put(dev);
256
257 c->clusterip = ip;
258 c->num_total_nodes = i->num_total_nodes;
259 clusterip_config_init_nodelist(c, i);
260 c->hash_mode = i->hash_mode;
261 c->hash_initval = i->hash_initval;
262 c->net = net;
263 refcount_set(&c->refcount, 1);
264
265 spin_lock_bh(&cn->lock);
266 if (__clusterip_config_find(net, ip)) {
267 err = -EBUSY;
268 goto out_config_put;
269 }
270
271 list_add_rcu(&c->list, &cn->configs);
272 spin_unlock_bh(&cn->lock);
273
274 #ifdef CONFIG_PROC_FS
275 {
276 char buffer[16];
277
278 /* create proc dir entry */
279 sprintf(buffer, "%pI4", &ip);
280 mutex_lock(&cn->mutex);
281 c->pde = proc_create_data(buffer, S_IWUSR|S_IRUSR,
282 cn->procdir,
283 &clusterip_proc_fops, c);
284 mutex_unlock(&cn->mutex);
285 if (!c->pde) {
286 err = -ENOMEM;
287 goto err;
288 }
289 }
290 #endif
291
292 refcount_set(&c->entries, 1);
293 return c;
294
295 #ifdef CONFIG_PROC_FS
296 err:
297 #endif
298 spin_lock_bh(&cn->lock);
299 list_del_rcu(&c->list);
300 out_config_put:
301 spin_unlock_bh(&cn->lock);
302 clusterip_config_put(c);
303 return ERR_PTR(err);
304 }
305
306 #ifdef CONFIG_PROC_FS
307 static int
308 clusterip_add_node(struct clusterip_config *c, u_int16_t nodenum)
309 {
310
311 if (nodenum == 0 ||
312 nodenum > c->num_total_nodes)
313 return 1;
314
315 /* check if we already have this number in our bitfield */
316 if (test_and_set_bit(nodenum - 1, &c->local_nodes))
317 return 1;
318
319 return 0;
320 }
321
322 static bool
323 clusterip_del_node(struct clusterip_config *c, u_int16_t nodenum)
324 {
325 if (nodenum == 0 ||
326 nodenum > c->num_total_nodes)
327 return true;
328
329 if (test_and_clear_bit(nodenum - 1, &c->local_nodes))
330 return false;
331
332 return true;
333 }
334 #endif
335
336 static inline u_int32_t
337 clusterip_hashfn(const struct sk_buff *skb,
338 const struct clusterip_config *config)
339 {
340 const struct iphdr *iph = ip_hdr(skb);
341 unsigned long hashval;
342 u_int16_t sport = 0, dport = 0;
343 int poff;
344
345 poff = proto_ports_offset(iph->protocol);
346 if (poff >= 0) {
347 const u_int16_t *ports;
348 u16 _ports[2];
349
350 ports = skb_header_pointer(skb, iph->ihl * 4 + poff, 4, _ports);
351 if (ports) {
352 sport = ports[0];
353 dport = ports[1];
354 }
355 } else {
356 net_info_ratelimited("unknown protocol %u\n", iph->protocol);
357 }
358
359 switch (config->hash_mode) {
360 case CLUSTERIP_HASHMODE_SIP:
361 hashval = jhash_1word(ntohl(iph->saddr),
362 config->hash_initval);
363 break;
364 case CLUSTERIP_HASHMODE_SIP_SPT:
365 hashval = jhash_2words(ntohl(iph->saddr), sport,
366 config->hash_initval);
367 break;
368 case CLUSTERIP_HASHMODE_SIP_SPT_DPT:
369 hashval = jhash_3words(ntohl(iph->saddr), sport, dport,
370 config->hash_initval);
371 break;
372 default:
373 /* to make gcc happy */
374 hashval = 0;
375 /* This cannot happen, unless the check function wasn't called
376 * at rule load time */
377 pr_info("unknown mode %u\n", config->hash_mode);
378 BUG();
379 break;
380 }
381
382 /* node numbers are 1..n, not 0..n */
383 return reciprocal_scale(hashval, config->num_total_nodes) + 1;
384 }
385
386 static inline int
387 clusterip_responsible(const struct clusterip_config *config, u_int32_t hash)
388 {
389 return test_bit(hash - 1, &config->local_nodes);
390 }
391
392 /***********************************************************************
393 * IPTABLES TARGET
394 ***********************************************************************/
395
396 static unsigned int
397 clusterip_tg(struct sk_buff *skb, const struct xt_action_param *par)
398 {
399 const struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
400 struct nf_conn *ct;
401 enum ip_conntrack_info ctinfo;
402 u_int32_t hash;
403
404 /* don't need to clusterip_config_get() here, since refcount
405 * is only decremented by destroy() - and ip_tables guarantees
406 * that the ->target() function isn't called after ->destroy() */
407
408 ct = nf_ct_get(skb, &ctinfo);
409 if (ct == NULL)
410 return NF_DROP;
411
412 /* special case: ICMP error handling. conntrack distinguishes between
413 * error messages (RELATED) and information requests (see below) */
414 if (ip_hdr(skb)->protocol == IPPROTO_ICMP &&
415 (ctinfo == IP_CT_RELATED ||
416 ctinfo == IP_CT_RELATED_REPLY))
417 return XT_CONTINUE;
418
419 /* ip_conntrack_icmp guarantees us that we only have ICMP_ECHO,
420 * TIMESTAMP, INFO_REQUEST or ADDRESS type icmp packets from here
421 * on, which all have an ID field [relevant for hashing]. */
422
423 hash = clusterip_hashfn(skb, cipinfo->config);
424
425 switch (ctinfo) {
426 case IP_CT_NEW:
427 ct->mark = hash;
428 break;
429 case IP_CT_RELATED:
430 case IP_CT_RELATED_REPLY:
431 /* FIXME: we don't handle expectations at the moment.
432 * They can arrive on a different node than
433 * the master connection (e.g. FTP passive mode) */
434 case IP_CT_ESTABLISHED:
435 case IP_CT_ESTABLISHED_REPLY:
436 break;
437 default: /* Prevent gcc warnings */
438 break;
439 }
440
441 #ifdef DEBUG
442 nf_ct_dump_tuple_ip(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
443 #endif
444 pr_debug("hash=%u ct_hash=%u ", hash, ct->mark);
445 if (!clusterip_responsible(cipinfo->config, hash)) {
446 pr_debug("not responsible\n");
447 return NF_DROP;
448 }
449 pr_debug("responsible\n");
450
451 /* despite being received via linklayer multicast, this is
452 * actually a unicast IP packet. TCP doesn't like PACKET_MULTICAST */
453 skb->pkt_type = PACKET_HOST;
454
455 return XT_CONTINUE;
456 }
457
458 static int clusterip_tg_check(const struct xt_tgchk_param *par)
459 {
460 struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
461 const struct ipt_entry *e = par->entryinfo;
462 struct clusterip_config *config;
463 int ret, i;
464
465 if (par->nft_compat) {
466 pr_err("cannot use CLUSTERIP target from nftables compat\n");
467 return -EOPNOTSUPP;
468 }
469
470 if (cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP &&
471 cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT &&
472 cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT_DPT) {
473 pr_info("unknown mode %u\n", cipinfo->hash_mode);
474 return -EINVAL;
475
476 }
477 if (e->ip.dmsk.s_addr != htonl(0xffffffff) ||
478 e->ip.dst.s_addr == 0) {
479 pr_info("Please specify destination IP\n");
480 return -EINVAL;
481 }
482 if (cipinfo->num_local_nodes > ARRAY_SIZE(cipinfo->local_nodes)) {
483 pr_info("bad num_local_nodes %u\n", cipinfo->num_local_nodes);
484 return -EINVAL;
485 }
486 for (i = 0; i < cipinfo->num_local_nodes; i++) {
487 if (cipinfo->local_nodes[i] - 1 >=
488 sizeof(config->local_nodes) * 8) {
489 pr_info("bad local_nodes[%d] %u\n",
490 i, cipinfo->local_nodes[i]);
491 return -EINVAL;
492 }
493 }
494
495 config = clusterip_config_find_get(par->net, e->ip.dst.s_addr, 1);
496 if (!config) {
497 if (!(cipinfo->flags & CLUSTERIP_FLAG_NEW)) {
498 pr_info("no config found for %pI4, need 'new'\n",
499 &e->ip.dst.s_addr);
500 return -EINVAL;
501 } else {
502 config = clusterip_config_init(par->net, cipinfo,
503 e->ip.dst.s_addr,
504 e->ip.iniface);
505 if (IS_ERR(config))
506 return PTR_ERR(config);
507 }
508 } else if (memcmp(&config->clustermac, &cipinfo->clustermac, ETH_ALEN))
509 return -EINVAL;
510
511 ret = nf_ct_netns_get(par->net, par->family);
512 if (ret < 0) {
513 pr_info("cannot load conntrack support for proto=%u\n",
514 par->family);
515 clusterip_config_entry_put(config);
516 clusterip_config_put(config);
517 return ret;
518 }
519
520 if (!par->net->xt.clusterip_deprecated_warning) {
521 pr_info("ipt_CLUSTERIP is deprecated and it will removed soon, "
522 "use xt_cluster instead\n");
523 par->net->xt.clusterip_deprecated_warning = true;
524 }
525
526 cipinfo->config = config;
527 return ret;
528 }
529
530 /* drop reference count of cluster config when rule is deleted */
531 static void clusterip_tg_destroy(const struct xt_tgdtor_param *par)
532 {
533 const struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
534
535 /* if no more entries are referencing the config, remove it
536 * from the list and destroy the proc entry */
537 clusterip_config_entry_put(cipinfo->config);
538
539 clusterip_config_put(cipinfo->config);
540
541 nf_ct_netns_put(par->net, par->family);
542 }
543
544 #ifdef CONFIG_COMPAT
545 struct compat_ipt_clusterip_tgt_info
546 {
547 u_int32_t flags;
548 u_int8_t clustermac[6];
549 u_int16_t num_total_nodes;
550 u_int16_t num_local_nodes;
551 u_int16_t local_nodes[CLUSTERIP_MAX_NODES];
552 u_int32_t hash_mode;
553 u_int32_t hash_initval;
554 compat_uptr_t config;
555 };
556 #endif /* CONFIG_COMPAT */
557
558 static struct xt_target clusterip_tg_reg __read_mostly = {
559 .name = "CLUSTERIP",
560 .family = NFPROTO_IPV4,
561 .target = clusterip_tg,
562 .checkentry = clusterip_tg_check,
563 .destroy = clusterip_tg_destroy,
564 .targetsize = sizeof(struct ipt_clusterip_tgt_info),
565 .usersize = offsetof(struct ipt_clusterip_tgt_info, config),
566 #ifdef CONFIG_COMPAT
567 .compatsize = sizeof(struct compat_ipt_clusterip_tgt_info),
568 #endif /* CONFIG_COMPAT */
569 .me = THIS_MODULE
570 };
571
572
573 /***********************************************************************
574 * ARP MANGLING CODE
575 ***********************************************************************/
576
577 /* hardcoded for 48bit ethernet and 32bit ipv4 addresses */
578 struct arp_payload {
579 u_int8_t src_hw[ETH_ALEN];
580 __be32 src_ip;
581 u_int8_t dst_hw[ETH_ALEN];
582 __be32 dst_ip;
583 } __packed;
584
585 #ifdef DEBUG
586 static void arp_print(struct arp_payload *payload)
587 {
588 #define HBUFFERLEN 30
589 char hbuffer[HBUFFERLEN];
590 int j, k;
591
592 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < ETH_ALEN; j++) {
593 hbuffer[k++] = hex_asc_hi(payload->src_hw[j]);
594 hbuffer[k++] = hex_asc_lo(payload->src_hw[j]);
595 hbuffer[k++] = ':';
596 }
597 hbuffer[--k] = '\0';
598
599 pr_debug("src %pI4@%s, dst %pI4\n",
600 &payload->src_ip, hbuffer, &payload->dst_ip);
601 }
602 #endif
603
604 static unsigned int
605 arp_mangle(void *priv,
606 struct sk_buff *skb,
607 const struct nf_hook_state *state)
608 {
609 struct arphdr *arp = arp_hdr(skb);
610 struct arp_payload *payload;
611 struct clusterip_config *c;
612 struct net *net = state->net;
613
614 /* we don't care about non-ethernet and non-ipv4 ARP */
615 if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
616 arp->ar_pro != htons(ETH_P_IP) ||
617 arp->ar_pln != 4 || arp->ar_hln != ETH_ALEN)
618 return NF_ACCEPT;
619
620 /* we only want to mangle arp requests and replies */
621 if (arp->ar_op != htons(ARPOP_REPLY) &&
622 arp->ar_op != htons(ARPOP_REQUEST))
623 return NF_ACCEPT;
624
625 payload = (void *)(arp+1);
626
627 /* if there is no clusterip configuration for the arp reply's
628 * source ip, we don't want to mangle it */
629 c = clusterip_config_find_get(net, payload->src_ip, 0);
630 if (!c)
631 return NF_ACCEPT;
632
633 /* normally the linux kernel always replies to arp queries of
634 * addresses on different interfacs. However, in the CLUSTERIP case
635 * this wouldn't work, since we didn't subscribe the mcast group on
636 * other interfaces */
637 if (c->ifindex != state->out->ifindex) {
638 pr_debug("not mangling arp reply on different interface: cip'%d'-skb'%d'\n",
639 c->ifindex, state->out->ifindex);
640 clusterip_config_put(c);
641 return NF_ACCEPT;
642 }
643
644 /* mangle reply hardware address */
645 memcpy(payload->src_hw, c->clustermac, arp->ar_hln);
646
647 #ifdef DEBUG
648 pr_debug("mangled arp reply: ");
649 arp_print(payload);
650 #endif
651
652 clusterip_config_put(c);
653
654 return NF_ACCEPT;
655 }
656
657 static const struct nf_hook_ops cip_arp_ops = {
658 .hook = arp_mangle,
659 .pf = NFPROTO_ARP,
660 .hooknum = NF_ARP_OUT,
661 .priority = -1
662 };
663
664 /***********************************************************************
665 * PROC DIR HANDLING
666 ***********************************************************************/
667
668 #ifdef CONFIG_PROC_FS
669
670 struct clusterip_seq_position {
671 unsigned int pos; /* position */
672 unsigned int weight; /* number of bits set == size */
673 unsigned int bit; /* current bit */
674 unsigned long val; /* current value */
675 };
676
677 static void *clusterip_seq_start(struct seq_file *s, loff_t *pos)
678 {
679 struct clusterip_config *c = s->private;
680 unsigned int weight;
681 u_int32_t local_nodes;
682 struct clusterip_seq_position *idx;
683
684 /* FIXME: possible race */
685 local_nodes = c->local_nodes;
686 weight = hweight32(local_nodes);
687 if (*pos >= weight)
688 return NULL;
689
690 idx = kmalloc(sizeof(struct clusterip_seq_position), GFP_KERNEL);
691 if (!idx)
692 return ERR_PTR(-ENOMEM);
693
694 idx->pos = *pos;
695 idx->weight = weight;
696 idx->bit = ffs(local_nodes);
697 idx->val = local_nodes;
698 clear_bit(idx->bit - 1, &idx->val);
699
700 return idx;
701 }
702
703 static void *clusterip_seq_next(struct seq_file *s, void *v, loff_t *pos)
704 {
705 struct clusterip_seq_position *idx = v;
706
707 *pos = ++idx->pos;
708 if (*pos >= idx->weight) {
709 kfree(v);
710 return NULL;
711 }
712 idx->bit = ffs(idx->val);
713 clear_bit(idx->bit - 1, &idx->val);
714 return idx;
715 }
716
717 static void clusterip_seq_stop(struct seq_file *s, void *v)
718 {
719 if (!IS_ERR(v))
720 kfree(v);
721 }
722
723 static int clusterip_seq_show(struct seq_file *s, void *v)
724 {
725 struct clusterip_seq_position *idx = v;
726
727 if (idx->pos != 0)
728 seq_putc(s, ',');
729
730 seq_printf(s, "%u", idx->bit);
731
732 if (idx->pos == idx->weight - 1)
733 seq_putc(s, '\n');
734
735 return 0;
736 }
737
738 static const struct seq_operations clusterip_seq_ops = {
739 .start = clusterip_seq_start,
740 .next = clusterip_seq_next,
741 .stop = clusterip_seq_stop,
742 .show = clusterip_seq_show,
743 };
744
745 static int clusterip_proc_open(struct inode *inode, struct file *file)
746 {
747 int ret = seq_open(file, &clusterip_seq_ops);
748
749 if (!ret) {
750 struct seq_file *sf = file->private_data;
751 struct clusterip_config *c = PDE_DATA(inode);
752
753 sf->private = c;
754
755 clusterip_config_get(c);
756 }
757
758 return ret;
759 }
760
761 static int clusterip_proc_release(struct inode *inode, struct file *file)
762 {
763 struct clusterip_config *c = PDE_DATA(inode);
764 int ret;
765
766 ret = seq_release(inode, file);
767
768 if (!ret)
769 clusterip_config_put(c);
770
771 return ret;
772 }
773
774 static ssize_t clusterip_proc_write(struct file *file, const char __user *input,
775 size_t size, loff_t *ofs)
776 {
777 struct clusterip_config *c = PDE_DATA(file_inode(file));
778 #define PROC_WRITELEN 10
779 char buffer[PROC_WRITELEN+1];
780 unsigned long nodenum;
781 int rc;
782
783 if (size > PROC_WRITELEN)
784 return -EIO;
785 if (copy_from_user(buffer, input, size))
786 return -EFAULT;
787 buffer[size] = 0;
788
789 if (*buffer == '+') {
790 rc = kstrtoul(buffer+1, 10, &nodenum);
791 if (rc)
792 return rc;
793 if (clusterip_add_node(c, nodenum))
794 return -ENOMEM;
795 } else if (*buffer == '-') {
796 rc = kstrtoul(buffer+1, 10, &nodenum);
797 if (rc)
798 return rc;
799 if (clusterip_del_node(c, nodenum))
800 return -ENOENT;
801 } else
802 return -EIO;
803
804 return size;
805 }
806
807 static const struct file_operations clusterip_proc_fops = {
808 .owner = THIS_MODULE,
809 .open = clusterip_proc_open,
810 .read = seq_read,
811 .write = clusterip_proc_write,
812 .llseek = seq_lseek,
813 .release = clusterip_proc_release,
814 };
815
816 #endif /* CONFIG_PROC_FS */
817
818 static int clusterip_net_init(struct net *net)
819 {
820 struct clusterip_net *cn = clusterip_pernet(net);
821 int ret;
822
823 INIT_LIST_HEAD(&cn->configs);
824
825 spin_lock_init(&cn->lock);
826
827 ret = nf_register_net_hook(net, &cip_arp_ops);
828 if (ret < 0)
829 return ret;
830
831 #ifdef CONFIG_PROC_FS
832 cn->procdir = proc_mkdir("ipt_CLUSTERIP", net->proc_net);
833 if (!cn->procdir) {
834 nf_unregister_net_hook(net, &cip_arp_ops);
835 pr_err("Unable to proc dir entry\n");
836 return -ENOMEM;
837 }
838 mutex_init(&cn->mutex);
839 #endif /* CONFIG_PROC_FS */
840
841 return 0;
842 }
843
844 static void clusterip_net_exit(struct net *net)
845 {
846 #ifdef CONFIG_PROC_FS
847 struct clusterip_net *cn = clusterip_pernet(net);
848
849 mutex_lock(&cn->mutex);
850 proc_remove(cn->procdir);
851 cn->procdir = NULL;
852 mutex_unlock(&cn->mutex);
853 #endif
854 nf_unregister_net_hook(net, &cip_arp_ops);
855 }
856
857 static struct pernet_operations clusterip_net_ops = {
858 .init = clusterip_net_init,
859 .exit = clusterip_net_exit,
860 .id = &clusterip_net_id,
861 .size = sizeof(struct clusterip_net),
862 };
863
864 struct notifier_block cip_netdev_notifier = {
865 .notifier_call = clusterip_netdev_event
866 };
867
868 static int __init clusterip_tg_init(void)
869 {
870 int ret;
871
872 ret = register_pernet_subsys(&clusterip_net_ops);
873 if (ret < 0)
874 return ret;
875
876 ret = xt_register_target(&clusterip_tg_reg);
877 if (ret < 0)
878 goto cleanup_subsys;
879
880 ret = register_netdevice_notifier(&cip_netdev_notifier);
881 if (ret < 0)
882 goto unregister_target;
883
884 pr_info("ClusterIP Version %s loaded successfully\n",
885 CLUSTERIP_VERSION);
886
887 return 0;
888
889 unregister_target:
890 xt_unregister_target(&clusterip_tg_reg);
891 cleanup_subsys:
892 unregister_pernet_subsys(&clusterip_net_ops);
893 return ret;
894 }
895
896 static void __exit clusterip_tg_exit(void)
897 {
898 pr_info("ClusterIP Version %s unloading\n", CLUSTERIP_VERSION);
899
900 unregister_netdevice_notifier(&cip_netdev_notifier);
901 xt_unregister_target(&clusterip_tg_reg);
902 unregister_pernet_subsys(&clusterip_net_ops);
903
904 /* Wait for completion of call_rcu_bh()'s (clusterip_config_rcu_free) */
905 rcu_barrier_bh();
906 }
907
908 module_init(clusterip_tg_init);
909 module_exit(clusterip_tg_exit);
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