~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/ipv4/netfilter/ipt_CLUSTERIP.c

Version: ~ [ linux-5.2-rc6 ] ~ [ linux-5.1.15 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.56 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.130 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.183 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.183 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.69 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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                 proc_remove(c->pde);
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                 net_info_ratelimited("unknown protocol %u\n", iph->protocol);
250         }
251 
252         switch (config->hash_mode) {
253         case CLUSTERIP_HASHMODE_SIP:
254                 hashval = jhash_1word(ntohl(iph->saddr),
255                                       config->hash_initval);
256                 break;
257         case CLUSTERIP_HASHMODE_SIP_SPT:
258                 hashval = jhash_2words(ntohl(iph->saddr), sport,
259                                        config->hash_initval);
260                 break;
261         case CLUSTERIP_HASHMODE_SIP_SPT_DPT:
262                 hashval = jhash_3words(ntohl(iph->saddr), sport, dport,
263                                        config->hash_initval);
264                 break;
265         default:
266                 /* to make gcc happy */
267                 hashval = 0;
268                 /* This cannot happen, unless the check function wasn't called
269                  * at rule load time */
270                 pr_info("unknown mode %u\n", config->hash_mode);
271                 BUG();
272                 break;
273         }
274 
275         /* node numbers are 1..n, not 0..n */
276         return (((u64)hashval * config->num_total_nodes) >> 32) + 1;
277 }
278 
279 static inline int
280 clusterip_responsible(const struct clusterip_config *config, u_int32_t hash)
281 {
282         return test_bit(hash - 1, &config->local_nodes);
283 }
284 
285 /***********************************************************************
286  * IPTABLES TARGET
287  ***********************************************************************/
288 
289 static unsigned int
290 clusterip_tg(struct sk_buff *skb, const struct xt_action_param *par)
291 {
292         const struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
293         struct nf_conn *ct;
294         enum ip_conntrack_info ctinfo;
295         u_int32_t hash;
296 
297         /* don't need to clusterip_config_get() here, since refcount
298          * is only decremented by destroy() - and ip_tables guarantees
299          * that the ->target() function isn't called after ->destroy() */
300 
301         ct = nf_ct_get(skb, &ctinfo);
302         if (ct == NULL)
303                 return NF_DROP;
304 
305         /* special case: ICMP error handling. conntrack distinguishes between
306          * error messages (RELATED) and information requests (see below) */
307         if (ip_hdr(skb)->protocol == IPPROTO_ICMP &&
308             (ctinfo == IP_CT_RELATED ||
309              ctinfo == IP_CT_RELATED_REPLY))
310                 return XT_CONTINUE;
311 
312         /* ip_conntrack_icmp guarantees us that we only have ICMP_ECHO,
313          * TIMESTAMP, INFO_REQUEST or ADDRESS type icmp packets from here
314          * on, which all have an ID field [relevant for hashing]. */
315 
316         hash = clusterip_hashfn(skb, cipinfo->config);
317 
318         switch (ctinfo) {
319         case IP_CT_NEW:
320                 ct->mark = hash;
321                 break;
322         case IP_CT_RELATED:
323         case IP_CT_RELATED_REPLY:
324                 /* FIXME: we don't handle expectations at the moment.
325                  * They can arrive on a different node than
326                  * the master connection (e.g. FTP passive mode) */
327         case IP_CT_ESTABLISHED:
328         case IP_CT_ESTABLISHED_REPLY:
329                 break;
330         default:                        /* Prevent gcc warnings */
331                 break;
332         }
333 
334 #ifdef DEBUG
335         nf_ct_dump_tuple_ip(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
336 #endif
337         pr_debug("hash=%u ct_hash=%u ", hash, ct->mark);
338         if (!clusterip_responsible(cipinfo->config, hash)) {
339                 pr_debug("not responsible\n");
340                 return NF_DROP;
341         }
342         pr_debug("responsible\n");
343 
344         /* despite being received via linklayer multicast, this is
345          * actually a unicast IP packet. TCP doesn't like PACKET_MULTICAST */
346         skb->pkt_type = PACKET_HOST;
347 
348         return XT_CONTINUE;
349 }
350 
351 static int clusterip_tg_check(const struct xt_tgchk_param *par)
352 {
353         struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
354         const struct ipt_entry *e = par->entryinfo;
355         struct clusterip_config *config;
356         int ret;
357 
358         if (cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP &&
359             cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT &&
360             cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT_DPT) {
361                 pr_info("unknown mode %u\n", cipinfo->hash_mode);
362                 return -EINVAL;
363 
364         }
365         if (e->ip.dmsk.s_addr != htonl(0xffffffff) ||
366             e->ip.dst.s_addr == 0) {
367                 pr_info("Please specify destination IP\n");
368                 return -EINVAL;
369         }
370 
371         /* FIXME: further sanity checks */
372 
373         config = clusterip_config_find_get(e->ip.dst.s_addr, 1);
374         if (!config) {
375                 if (!(cipinfo->flags & CLUSTERIP_FLAG_NEW)) {
376                         pr_info("no config found for %pI4, need 'new'\n",
377                                 &e->ip.dst.s_addr);
378                         return -EINVAL;
379                 } else {
380                         struct net_device *dev;
381 
382                         if (e->ip.iniface[0] == '\0') {
383                                 pr_info("Please specify an interface name\n");
384                                 return -EINVAL;
385                         }
386 
387                         dev = dev_get_by_name(&init_net, e->ip.iniface);
388                         if (!dev) {
389                                 pr_info("no such interface %s\n",
390                                         e->ip.iniface);
391                                 return -ENOENT;
392                         }
393 
394                         config = clusterip_config_init(cipinfo,
395                                                         e->ip.dst.s_addr, dev);
396                         if (!config) {
397                                 dev_put(dev);
398                                 return -ENOMEM;
399                         }
400                         dev_mc_add(config->dev, config->clustermac);
401                 }
402         }
403         cipinfo->config = config;
404 
405         ret = nf_ct_l3proto_try_module_get(par->family);
406         if (ret < 0)
407                 pr_info("cannot load conntrack support for proto=%u\n",
408                         par->family);
409         return ret;
410 }
411 
412 /* drop reference count of cluster config when rule is deleted */
413 static void clusterip_tg_destroy(const struct xt_tgdtor_param *par)
414 {
415         const struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
416 
417         /* if no more entries are referencing the config, remove it
418          * from the list and destroy the proc entry */
419         clusterip_config_entry_put(cipinfo->config);
420 
421         clusterip_config_put(cipinfo->config);
422 
423         nf_ct_l3proto_module_put(par->family);
424 }
425 
426 #ifdef CONFIG_COMPAT
427 struct compat_ipt_clusterip_tgt_info
428 {
429         u_int32_t       flags;
430         u_int8_t        clustermac[6];
431         u_int16_t       num_total_nodes;
432         u_int16_t       num_local_nodes;
433         u_int16_t       local_nodes[CLUSTERIP_MAX_NODES];
434         u_int32_t       hash_mode;
435         u_int32_t       hash_initval;
436         compat_uptr_t   config;
437 };
438 #endif /* CONFIG_COMPAT */
439 
440 static struct xt_target clusterip_tg_reg __read_mostly = {
441         .name           = "CLUSTERIP",
442         .family         = NFPROTO_IPV4,
443         .target         = clusterip_tg,
444         .checkentry     = clusterip_tg_check,
445         .destroy        = clusterip_tg_destroy,
446         .targetsize     = sizeof(struct ipt_clusterip_tgt_info),
447 #ifdef CONFIG_COMPAT
448         .compatsize     = sizeof(struct compat_ipt_clusterip_tgt_info),
449 #endif /* CONFIG_COMPAT */
450         .me             = THIS_MODULE
451 };
452 
453 
454 /***********************************************************************
455  * ARP MANGLING CODE
456  ***********************************************************************/
457 
458 /* hardcoded for 48bit ethernet and 32bit ipv4 addresses */
459 struct arp_payload {
460         u_int8_t src_hw[ETH_ALEN];
461         __be32 src_ip;
462         u_int8_t dst_hw[ETH_ALEN];
463         __be32 dst_ip;
464 } __packed;
465 
466 #ifdef DEBUG
467 static void arp_print(struct arp_payload *payload)
468 {
469 #define HBUFFERLEN 30
470         char hbuffer[HBUFFERLEN];
471         int j,k;
472 
473         for (k=0, j=0; k < HBUFFERLEN-3 && j < ETH_ALEN; j++) {
474                 hbuffer[k++] = hex_asc_hi(payload->src_hw[j]);
475                 hbuffer[k++] = hex_asc_lo(payload->src_hw[j]);
476                 hbuffer[k++]=':';
477         }
478         hbuffer[--k]='\0';
479 
480         pr_debug("src %pI4@%s, dst %pI4\n",
481                  &payload->src_ip, hbuffer, &payload->dst_ip);
482 }
483 #endif
484 
485 static unsigned int
486 arp_mangle(unsigned int hook,
487            struct sk_buff *skb,
488            const struct net_device *in,
489            const struct net_device *out,
490            int (*okfn)(struct sk_buff *))
491 {
492         struct arphdr *arp = arp_hdr(skb);
493         struct arp_payload *payload;
494         struct clusterip_config *c;
495 
496         /* we don't care about non-ethernet and non-ipv4 ARP */
497         if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
498             arp->ar_pro != htons(ETH_P_IP) ||
499             arp->ar_pln != 4 || arp->ar_hln != ETH_ALEN)
500                 return NF_ACCEPT;
501 
502         /* we only want to mangle arp requests and replies */
503         if (arp->ar_op != htons(ARPOP_REPLY) &&
504             arp->ar_op != htons(ARPOP_REQUEST))
505                 return NF_ACCEPT;
506 
507         payload = (void *)(arp+1);
508 
509         /* if there is no clusterip configuration for the arp reply's
510          * source ip, we don't want to mangle it */
511         c = clusterip_config_find_get(payload->src_ip, 0);
512         if (!c)
513                 return NF_ACCEPT;
514 
515         /* normally the linux kernel always replies to arp queries of
516          * addresses on different interfacs.  However, in the CLUSTERIP case
517          * this wouldn't work, since we didn't subscribe the mcast group on
518          * other interfaces */
519         if (c->dev != out) {
520                 pr_debug("not mangling arp reply on different "
521                          "interface: cip'%s'-skb'%s'\n",
522                          c->dev->name, out->name);
523                 clusterip_config_put(c);
524                 return NF_ACCEPT;
525         }
526 
527         /* mangle reply hardware address */
528         memcpy(payload->src_hw, c->clustermac, arp->ar_hln);
529 
530 #ifdef DEBUG
531         pr_debug("mangled arp reply: ");
532         arp_print(payload);
533 #endif
534 
535         clusterip_config_put(c);
536 
537         return NF_ACCEPT;
538 }
539 
540 static struct nf_hook_ops cip_arp_ops __read_mostly = {
541         .hook = arp_mangle,
542         .pf = NFPROTO_ARP,
543         .hooknum = NF_ARP_OUT,
544         .priority = -1
545 };
546 
547 /***********************************************************************
548  * PROC DIR HANDLING
549  ***********************************************************************/
550 
551 #ifdef CONFIG_PROC_FS
552 
553 struct clusterip_seq_position {
554         unsigned int pos;       /* position */
555         unsigned int weight;    /* number of bits set == size */
556         unsigned int bit;       /* current bit */
557         unsigned long val;      /* current value */
558 };
559 
560 static void *clusterip_seq_start(struct seq_file *s, loff_t *pos)
561 {
562         struct clusterip_config *c = s->private;
563         unsigned int weight;
564         u_int32_t local_nodes;
565         struct clusterip_seq_position *idx;
566 
567         /* FIXME: possible race */
568         local_nodes = c->local_nodes;
569         weight = hweight32(local_nodes);
570         if (*pos >= weight)
571                 return NULL;
572 
573         idx = kmalloc(sizeof(struct clusterip_seq_position), GFP_KERNEL);
574         if (!idx)
575                 return ERR_PTR(-ENOMEM);
576 
577         idx->pos = *pos;
578         idx->weight = weight;
579         idx->bit = ffs(local_nodes);
580         idx->val = local_nodes;
581         clear_bit(idx->bit - 1, &idx->val);
582 
583         return idx;
584 }
585 
586 static void *clusterip_seq_next(struct seq_file *s, void *v, loff_t *pos)
587 {
588         struct clusterip_seq_position *idx = v;
589 
590         *pos = ++idx->pos;
591         if (*pos >= idx->weight) {
592                 kfree(v);
593                 return NULL;
594         }
595         idx->bit = ffs(idx->val);
596         clear_bit(idx->bit - 1, &idx->val);
597         return idx;
598 }
599 
600 static void clusterip_seq_stop(struct seq_file *s, void *v)
601 {
602         if (!IS_ERR(v))
603                 kfree(v);
604 }
605 
606 static int clusterip_seq_show(struct seq_file *s, void *v)
607 {
608         struct clusterip_seq_position *idx = v;
609 
610         if (idx->pos != 0)
611                 seq_putc(s, ',');
612 
613         seq_printf(s, "%u", idx->bit);
614 
615         if (idx->pos == idx->weight - 1)
616                 seq_putc(s, '\n');
617 
618         return 0;
619 }
620 
621 static const struct seq_operations clusterip_seq_ops = {
622         .start  = clusterip_seq_start,
623         .next   = clusterip_seq_next,
624         .stop   = clusterip_seq_stop,
625         .show   = clusterip_seq_show,
626 };
627 
628 static int clusterip_proc_open(struct inode *inode, struct file *file)
629 {
630         int ret = seq_open(file, &clusterip_seq_ops);
631 
632         if (!ret) {
633                 struct seq_file *sf = file->private_data;
634                 struct clusterip_config *c = PDE_DATA(inode);
635 
636                 sf->private = c;
637 
638                 clusterip_config_get(c);
639         }
640 
641         return ret;
642 }
643 
644 static int clusterip_proc_release(struct inode *inode, struct file *file)
645 {
646         struct clusterip_config *c = PDE_DATA(inode);
647         int ret;
648 
649         ret = seq_release(inode, file);
650 
651         if (!ret)
652                 clusterip_config_put(c);
653 
654         return ret;
655 }
656 
657 static ssize_t clusterip_proc_write(struct file *file, const char __user *input,
658                                 size_t size, loff_t *ofs)
659 {
660         struct clusterip_config *c = PDE_DATA(file_inode(file));
661 #define PROC_WRITELEN   10
662         char buffer[PROC_WRITELEN+1];
663         unsigned long nodenum;
664         int rc;
665 
666         if (size > PROC_WRITELEN)
667                 return -EIO;
668         if (copy_from_user(buffer, input, size))
669                 return -EFAULT;
670         buffer[size] = 0;
671 
672         if (*buffer == '+') {
673                 rc = kstrtoul(buffer+1, 10, &nodenum);
674                 if (rc)
675                         return rc;
676                 if (clusterip_add_node(c, nodenum))
677                         return -ENOMEM;
678         } else if (*buffer == '-') {
679                 rc = kstrtoul(buffer+1, 10, &nodenum);
680                 if (rc)
681                         return rc;
682                 if (clusterip_del_node(c, nodenum))
683                         return -ENOENT;
684         } else
685                 return -EIO;
686 
687         return size;
688 }
689 
690 static const struct file_operations clusterip_proc_fops = {
691         .owner   = THIS_MODULE,
692         .open    = clusterip_proc_open,
693         .read    = seq_read,
694         .write   = clusterip_proc_write,
695         .llseek  = seq_lseek,
696         .release = clusterip_proc_release,
697 };
698 
699 #endif /* CONFIG_PROC_FS */
700 
701 static int __init clusterip_tg_init(void)
702 {
703         int ret;
704 
705         ret = xt_register_target(&clusterip_tg_reg);
706         if (ret < 0)
707                 return ret;
708 
709         ret = nf_register_hook(&cip_arp_ops);
710         if (ret < 0)
711                 goto cleanup_target;
712 
713 #ifdef CONFIG_PROC_FS
714         clusterip_procdir = proc_mkdir("ipt_CLUSTERIP", init_net.proc_net);
715         if (!clusterip_procdir) {
716                 pr_err("Unable to proc dir entry\n");
717                 ret = -ENOMEM;
718                 goto cleanup_hook;
719         }
720 #endif /* CONFIG_PROC_FS */
721 
722         pr_info("ClusterIP Version %s loaded successfully\n",
723                 CLUSTERIP_VERSION);
724         return 0;
725 
726 #ifdef CONFIG_PROC_FS
727 cleanup_hook:
728         nf_unregister_hook(&cip_arp_ops);
729 #endif /* CONFIG_PROC_FS */
730 cleanup_target:
731         xt_unregister_target(&clusterip_tg_reg);
732         return ret;
733 }
734 
735 static void __exit clusterip_tg_exit(void)
736 {
737         pr_info("ClusterIP Version %s unloading\n", CLUSTERIP_VERSION);
738 #ifdef CONFIG_PROC_FS
739         proc_remove(clusterip_procdir);
740 #endif
741         nf_unregister_hook(&cip_arp_ops);
742         xt_unregister_target(&clusterip_tg_reg);
743 
744         /* Wait for completion of call_rcu_bh()'s (clusterip_config_rcu_free) */
745         rcu_barrier_bh();
746 }
747 
748 module_init(clusterip_tg_init);
749 module_exit(clusterip_tg_exit);
750 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp