Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | #include <linux/module.h> | |
1da177e4 LT |
13 | #include <linux/proc_fs.h> |
14 | #include <linux/jhash.h> | |
136e92bb | 15 | #include <linux/bitops.h> |
1da177e4 LT |
16 | #include <linux/skbuff.h> |
17 | #include <linux/ip.h> | |
18 | #include <linux/tcp.h> | |
19 | #include <linux/udp.h> | |
20 | #include <linux/icmp.h> | |
21 | #include <linux/if_arp.h> | |
22 | #include <linux/proc_fs.h> | |
23 | #include <linux/seq_file.h> | |
24 | ||
25 | #include <net/checksum.h> | |
26 | ||
27 | #include <linux/netfilter_arp.h> | |
28 | ||
29 | #include <linux/netfilter_ipv4/ip_tables.h> | |
30 | #include <linux/netfilter_ipv4/ipt_CLUSTERIP.h> | |
9fb9cbb1 | 31 | #include <net/netfilter/nf_conntrack_compat.h> |
1da177e4 | 32 | |
136e92bb | 33 | #define CLUSTERIP_VERSION "0.8" |
1da177e4 LT |
34 | |
35 | #define DEBUG_CLUSTERIP | |
36 | ||
37 | #ifdef DEBUG_CLUSTERIP | |
38 | #define DEBUGP printk | |
39 | #else | |
40 | #define DEBUGP | |
41 | #endif | |
42 | ||
e45b1be8 PM |
43 | #define ASSERT_READ_LOCK(x) |
44 | ||
1da177e4 LT |
45 | MODULE_LICENSE("GPL"); |
46 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
47 | MODULE_DESCRIPTION("iptables target for CLUSTERIP"); | |
48 | ||
49 | struct clusterip_config { | |
50 | struct list_head list; /* list of all configs */ | |
51 | atomic_t refcount; /* reference count */ | |
44513624 KK |
52 | atomic_t entries; /* number of entries/rules |
53 | * referencing us */ | |
1da177e4 LT |
54 | |
55 | u_int32_t clusterip; /* the IP address */ | |
56 | u_int8_t clustermac[ETH_ALEN]; /* the MAC address */ | |
57 | struct net_device *dev; /* device */ | |
58 | u_int16_t num_total_nodes; /* total number of nodes */ | |
136e92bb | 59 | unsigned long local_nodes; /* node number array */ |
1da177e4 LT |
60 | |
61 | #ifdef CONFIG_PROC_FS | |
62 | struct proc_dir_entry *pde; /* proc dir entry */ | |
63 | #endif | |
64 | enum clusterip_hashmode hash_mode; /* which hashing mode */ | |
65 | u_int32_t hash_initval; /* hash initialization */ | |
66 | }; | |
67 | ||
68 | static LIST_HEAD(clusterip_configs); | |
69 | ||
136e92bb | 70 | /* clusterip_lock protects the clusterip_configs list */ |
e45b1be8 | 71 | static DEFINE_RWLOCK(clusterip_lock); |
1da177e4 LT |
72 | |
73 | #ifdef CONFIG_PROC_FS | |
74 | static struct file_operations clusterip_proc_fops; | |
75 | static struct proc_dir_entry *clusterip_procdir; | |
76 | #endif | |
77 | ||
78 | static inline void | |
44513624 KK |
79 | clusterip_config_get(struct clusterip_config *c) |
80 | { | |
1da177e4 LT |
81 | atomic_inc(&c->refcount); |
82 | } | |
83 | ||
84 | static inline void | |
44513624 KK |
85 | clusterip_config_put(struct clusterip_config *c) |
86 | { | |
87 | if (atomic_dec_and_test(&c->refcount)) | |
88 | kfree(c); | |
89 | } | |
90 | ||
91 | /* increase the count of entries(rules) using/referencing this config */ | |
92 | static inline void | |
93 | clusterip_config_entry_get(struct clusterip_config *c) | |
94 | { | |
95 | atomic_inc(&c->entries); | |
96 | } | |
97 | ||
98 | /* decrease the count of entries using/referencing this config. If last | |
99 | * entry(rule) is removed, remove the config from lists, but don't free it | |
100 | * yet, since proc-files could still be holding references */ | |
101 | static inline void | |
102 | clusterip_config_entry_put(struct clusterip_config *c) | |
103 | { | |
104 | if (atomic_dec_and_test(&c->entries)) { | |
e45b1be8 | 105 | write_lock_bh(&clusterip_lock); |
1da177e4 | 106 | list_del(&c->list); |
e45b1be8 | 107 | write_unlock_bh(&clusterip_lock); |
44513624 | 108 | |
1da177e4 LT |
109 | dev_mc_delete(c->dev, c->clustermac, ETH_ALEN, 0); |
110 | dev_put(c->dev); | |
44513624 KK |
111 | |
112 | /* In case anyone still accesses the file, the open/close | |
113 | * functions are also incrementing the refcount on their own, | |
114 | * so it's safe to remove the entry even if it's in use. */ | |
115 | #ifdef CONFIG_PROC_FS | |
116 | remove_proc_entry(c->pde->name, c->pde->parent); | |
117 | #endif | |
1da177e4 LT |
118 | } |
119 | } | |
120 | ||
1da177e4 LT |
121 | static struct clusterip_config * |
122 | __clusterip_config_find(u_int32_t clusterip) | |
123 | { | |
124 | struct list_head *pos; | |
125 | ||
e45b1be8 | 126 | ASSERT_READ_LOCK(&clusterip_lock); |
1da177e4 LT |
127 | list_for_each(pos, &clusterip_configs) { |
128 | struct clusterip_config *c = list_entry(pos, | |
129 | struct clusterip_config, list); | |
130 | if (c->clusterip == clusterip) { | |
131 | return c; | |
132 | } | |
133 | } | |
134 | ||
135 | return NULL; | |
136 | } | |
137 | ||
138 | static inline struct clusterip_config * | |
44513624 | 139 | clusterip_config_find_get(u_int32_t clusterip, int entry) |
1da177e4 LT |
140 | { |
141 | struct clusterip_config *c; | |
142 | ||
e45b1be8 | 143 | read_lock_bh(&clusterip_lock); |
1da177e4 LT |
144 | c = __clusterip_config_find(clusterip); |
145 | if (!c) { | |
e45b1be8 | 146 | read_unlock_bh(&clusterip_lock); |
1da177e4 LT |
147 | return NULL; |
148 | } | |
149 | atomic_inc(&c->refcount); | |
44513624 KK |
150 | if (entry) |
151 | atomic_inc(&c->entries); | |
e45b1be8 | 152 | read_unlock_bh(&clusterip_lock); |
1da177e4 LT |
153 | |
154 | return c; | |
155 | } | |
156 | ||
136e92bb KK |
157 | static void |
158 | clusterip_config_init_nodelist(struct clusterip_config *c, | |
159 | const struct ipt_clusterip_tgt_info *i) | |
160 | { | |
161 | int n; | |
162 | ||
163 | for (n = 0; n < i->num_local_nodes; n++) { | |
164 | set_bit(i->local_nodes[n] - 1, &c->local_nodes); | |
165 | } | |
166 | } | |
167 | ||
1da177e4 LT |
168 | static struct clusterip_config * |
169 | clusterip_config_init(struct ipt_clusterip_tgt_info *i, u_int32_t ip, | |
170 | struct net_device *dev) | |
171 | { | |
172 | struct clusterip_config *c; | |
173 | char buffer[16]; | |
174 | ||
0da974f4 | 175 | c = kzalloc(sizeof(*c), GFP_ATOMIC); |
1da177e4 LT |
176 | if (!c) |
177 | return NULL; | |
178 | ||
1da177e4 LT |
179 | c->dev = dev; |
180 | c->clusterip = ip; | |
181 | memcpy(&c->clustermac, &i->clustermac, ETH_ALEN); | |
182 | c->num_total_nodes = i->num_total_nodes; | |
136e92bb | 183 | clusterip_config_init_nodelist(c, i); |
1da177e4 LT |
184 | c->hash_mode = i->hash_mode; |
185 | c->hash_initval = i->hash_initval; | |
186 | atomic_set(&c->refcount, 1); | |
44513624 | 187 | atomic_set(&c->entries, 1); |
1da177e4 LT |
188 | |
189 | #ifdef CONFIG_PROC_FS | |
190 | /* create proc dir entry */ | |
191 | sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(ip)); | |
192 | c->pde = create_proc_entry(buffer, S_IWUSR|S_IRUSR, clusterip_procdir); | |
193 | if (!c->pde) { | |
194 | kfree(c); | |
195 | return NULL; | |
196 | } | |
197 | c->pde->proc_fops = &clusterip_proc_fops; | |
198 | c->pde->data = c; | |
199 | #endif | |
200 | ||
e45b1be8 | 201 | write_lock_bh(&clusterip_lock); |
1da177e4 | 202 | list_add(&c->list, &clusterip_configs); |
e45b1be8 | 203 | write_unlock_bh(&clusterip_lock); |
1da177e4 LT |
204 | |
205 | return c; | |
206 | } | |
207 | ||
208 | static int | |
209 | clusterip_add_node(struct clusterip_config *c, u_int16_t nodenum) | |
210 | { | |
1da177e4 | 211 | |
136e92bb KK |
212 | if (nodenum == 0 || |
213 | nodenum > c->num_total_nodes) | |
1da177e4 | 214 | return 1; |
1da177e4 | 215 | |
136e92bb KK |
216 | /* check if we already have this number in our bitfield */ |
217 | if (test_and_set_bit(nodenum - 1, &c->local_nodes)) | |
218 | return 1; | |
1da177e4 | 219 | |
1da177e4 LT |
220 | return 0; |
221 | } | |
222 | ||
223 | static int | |
224 | clusterip_del_node(struct clusterip_config *c, u_int16_t nodenum) | |
225 | { | |
136e92bb KK |
226 | if (nodenum == 0 || |
227 | nodenum > c->num_total_nodes) | |
1da177e4 | 228 | return 1; |
1da177e4 | 229 | |
136e92bb KK |
230 | if (test_and_clear_bit(nodenum - 1, &c->local_nodes)) |
231 | return 0; | |
1da177e4 | 232 | |
1da177e4 LT |
233 | return 1; |
234 | } | |
235 | ||
236 | static inline u_int32_t | |
237 | clusterip_hashfn(struct sk_buff *skb, struct clusterip_config *config) | |
238 | { | |
239 | struct iphdr *iph = skb->nh.iph; | |
240 | unsigned long hashval; | |
241 | u_int16_t sport, dport; | |
957dc80a | 242 | u_int16_t *ports; |
1da177e4 LT |
243 | |
244 | switch (iph->protocol) { | |
245 | case IPPROTO_TCP: | |
1da177e4 | 246 | case IPPROTO_UDP: |
957dc80a PM |
247 | case IPPROTO_SCTP: |
248 | case IPPROTO_DCCP: | |
1da177e4 | 249 | case IPPROTO_ICMP: |
957dc80a PM |
250 | ports = (void *)iph+iph->ihl*4; |
251 | sport = ports[0]; | |
252 | dport = ports[1]; | |
1da177e4 LT |
253 | break; |
254 | default: | |
255 | if (net_ratelimit()) { | |
256 | printk(KERN_NOTICE "CLUSTERIP: unknown protocol `%u'\n", | |
257 | iph->protocol); | |
258 | } | |
259 | sport = dport = 0; | |
260 | } | |
261 | ||
262 | switch (config->hash_mode) { | |
263 | case CLUSTERIP_HASHMODE_SIP: | |
264 | hashval = jhash_1word(ntohl(iph->saddr), | |
265 | config->hash_initval); | |
266 | break; | |
267 | case CLUSTERIP_HASHMODE_SIP_SPT: | |
268 | hashval = jhash_2words(ntohl(iph->saddr), sport, | |
269 | config->hash_initval); | |
270 | break; | |
271 | case CLUSTERIP_HASHMODE_SIP_SPT_DPT: | |
272 | hashval = jhash_3words(ntohl(iph->saddr), sport, dport, | |
273 | config->hash_initval); | |
274 | break; | |
275 | default: | |
276 | /* to make gcc happy */ | |
277 | hashval = 0; | |
278 | /* This cannot happen, unless the check function wasn't called | |
279 | * at rule load time */ | |
280 | printk("CLUSTERIP: unknown mode `%u'\n", config->hash_mode); | |
281 | BUG(); | |
282 | break; | |
283 | } | |
284 | ||
285 | /* node numbers are 1..n, not 0..n */ | |
286 | return ((hashval % config->num_total_nodes)+1); | |
287 | } | |
288 | ||
289 | static inline int | |
290 | clusterip_responsible(struct clusterip_config *config, u_int32_t hash) | |
291 | { | |
136e92bb | 292 | return test_bit(hash - 1, &config->local_nodes); |
1da177e4 LT |
293 | } |
294 | ||
295 | /*********************************************************************** | |
296 | * IPTABLES TARGET | |
297 | ***********************************************************************/ | |
298 | ||
299 | static unsigned int | |
300 | target(struct sk_buff **pskb, | |
301 | const struct net_device *in, | |
302 | const struct net_device *out, | |
303 | unsigned int hooknum, | |
c4986734 | 304 | const struct xt_target *target, |
1da177e4 LT |
305 | const void *targinfo, |
306 | void *userinfo) | |
307 | { | |
308 | const struct ipt_clusterip_tgt_info *cipinfo = targinfo; | |
309 | enum ip_conntrack_info ctinfo; | |
9fb9cbb1 | 310 | u_int32_t *mark, hash; |
1da177e4 LT |
311 | |
312 | /* don't need to clusterip_config_get() here, since refcount | |
313 | * is only decremented by destroy() - and ip_tables guarantees | |
314 | * that the ->target() function isn't called after ->destroy() */ | |
315 | ||
9fb9cbb1 YK |
316 | mark = nf_ct_get_mark((*pskb), &ctinfo); |
317 | if (mark == NULL) { | |
1da177e4 LT |
318 | printk(KERN_ERR "CLUSTERIP: no conntrack!\n"); |
319 | /* FIXME: need to drop invalid ones, since replies | |
320 | * to outgoing connections of other nodes will be | |
321 | * marked as INVALID */ | |
322 | return NF_DROP; | |
323 | } | |
324 | ||
325 | /* special case: ICMP error handling. conntrack distinguishes between | |
326 | * error messages (RELATED) and information requests (see below) */ | |
327 | if ((*pskb)->nh.iph->protocol == IPPROTO_ICMP | |
328 | && (ctinfo == IP_CT_RELATED | |
5d927eb0 | 329 | || ctinfo == IP_CT_RELATED+IP_CT_IS_REPLY)) |
1da177e4 LT |
330 | return IPT_CONTINUE; |
331 | ||
332 | /* ip_conntrack_icmp guarantees us that we only have ICMP_ECHO, | |
333 | * TIMESTAMP, INFO_REQUEST or ADDRESS type icmp packets from here | |
334 | * on, which all have an ID field [relevant for hashing]. */ | |
335 | ||
336 | hash = clusterip_hashfn(*pskb, cipinfo->config); | |
337 | ||
338 | switch (ctinfo) { | |
339 | case IP_CT_NEW: | |
9fb9cbb1 | 340 | *mark = hash; |
1da177e4 LT |
341 | break; |
342 | case IP_CT_RELATED: | |
343 | case IP_CT_RELATED+IP_CT_IS_REPLY: | |
344 | /* FIXME: we don't handle expectations at the | |
345 | * moment. they can arrive on a different node than | |
346 | * the master connection (e.g. FTP passive mode) */ | |
347 | case IP_CT_ESTABLISHED: | |
348 | case IP_CT_ESTABLISHED+IP_CT_IS_REPLY: | |
349 | break; | |
350 | default: | |
351 | break; | |
352 | } | |
353 | ||
354 | #ifdef DEBUG_CLUSTERP | |
355 | DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
356 | #endif | |
9fb9cbb1 | 357 | DEBUGP("hash=%u ct_hash=%u ", hash, *mark); |
1da177e4 LT |
358 | if (!clusterip_responsible(cipinfo->config, hash)) { |
359 | DEBUGP("not responsible\n"); | |
360 | return NF_DROP; | |
361 | } | |
362 | DEBUGP("responsible\n"); | |
363 | ||
364 | /* despite being received via linklayer multicast, this is | |
365 | * actually a unicast IP packet. TCP doesn't like PACKET_MULTICAST */ | |
366 | (*pskb)->pkt_type = PACKET_HOST; | |
367 | ||
368 | return IPT_CONTINUE; | |
369 | } | |
370 | ||
371 | static int | |
372 | checkentry(const char *tablename, | |
2e4e6a17 | 373 | const void *e_void, |
c4986734 | 374 | const struct xt_target *target, |
1da177e4 LT |
375 | void *targinfo, |
376 | unsigned int targinfosize, | |
377 | unsigned int hook_mask) | |
378 | { | |
379 | struct ipt_clusterip_tgt_info *cipinfo = targinfo; | |
2e4e6a17 | 380 | const struct ipt_entry *e = e_void; |
1da177e4 LT |
381 | |
382 | struct clusterip_config *config; | |
383 | ||
1da177e4 LT |
384 | if (cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP && |
385 | cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT && | |
386 | cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT_DPT) { | |
387 | printk(KERN_WARNING "CLUSTERIP: unknown mode `%u'\n", | |
388 | cipinfo->hash_mode); | |
389 | return 0; | |
390 | ||
391 | } | |
392 | if (e->ip.dmsk.s_addr != 0xffffffff | |
393 | || e->ip.dst.s_addr == 0) { | |
394 | printk(KERN_ERR "CLUSTERIP: Please specify destination IP\n"); | |
395 | return 0; | |
396 | } | |
397 | ||
398 | /* FIXME: further sanity checks */ | |
399 | ||
44513624 KK |
400 | config = clusterip_config_find_get(e->ip.dst.s_addr, 1); |
401 | if (config) { | |
402 | if (cipinfo->config != NULL) { | |
403 | /* Case A: This is an entry that gets reloaded, since | |
404 | * it still has a cipinfo->config pointer. Simply | |
405 | * increase the entry refcount and return */ | |
406 | if (cipinfo->config != config) { | |
407 | printk(KERN_ERR "CLUSTERIP: Reloaded entry " | |
408 | "has invalid config pointer!\n"); | |
409 | return 0; | |
410 | } | |
411 | clusterip_config_entry_get(cipinfo->config); | |
412 | } else { | |
413 | /* Case B: This is a new rule referring to an existing | |
414 | * clusterip config. */ | |
415 | cipinfo->config = config; | |
416 | clusterip_config_entry_get(cipinfo->config); | |
417 | } | |
418 | } else { | |
419 | /* Case C: This is a completely new clusterip config */ | |
1da177e4 LT |
420 | if (!(cipinfo->flags & CLUSTERIP_FLAG_NEW)) { |
421 | printk(KERN_WARNING "CLUSTERIP: no config found for %u.%u.%u.%u, need 'new'\n", NIPQUAD(e->ip.dst.s_addr)); | |
422 | return 0; | |
423 | } else { | |
424 | struct net_device *dev; | |
425 | ||
426 | if (e->ip.iniface[0] == '\0') { | |
427 | printk(KERN_WARNING "CLUSTERIP: Please specify an interface name\n"); | |
428 | return 0; | |
429 | } | |
430 | ||
431 | dev = dev_get_by_name(e->ip.iniface); | |
432 | if (!dev) { | |
433 | printk(KERN_WARNING "CLUSTERIP: no such interface %s\n", e->ip.iniface); | |
434 | return 0; | |
435 | } | |
436 | ||
437 | config = clusterip_config_init(cipinfo, | |
438 | e->ip.dst.s_addr, dev); | |
439 | if (!config) { | |
440 | printk(KERN_WARNING "CLUSTERIP: cannot allocate config\n"); | |
441 | dev_put(dev); | |
442 | return 0; | |
443 | } | |
444 | dev_mc_add(config->dev,config->clustermac, ETH_ALEN, 0); | |
445 | } | |
44513624 | 446 | cipinfo->config = config; |
1da177e4 LT |
447 | } |
448 | ||
1da177e4 LT |
449 | return 1; |
450 | } | |
451 | ||
452 | /* drop reference count of cluster config when rule is deleted */ | |
c4986734 PM |
453 | static void destroy(const struct xt_target *target, void *targinfo, |
454 | unsigned int targinfosize) | |
1da177e4 | 455 | { |
c4986734 | 456 | struct ipt_clusterip_tgt_info *cipinfo = targinfo; |
1da177e4 | 457 | |
44513624 KK |
458 | /* if no more entries are referencing the config, remove it |
459 | * from the list and destroy the proc entry */ | |
460 | clusterip_config_entry_put(cipinfo->config); | |
461 | ||
1da177e4 LT |
462 | clusterip_config_put(cipinfo->config); |
463 | } | |
464 | ||
1d5cd909 PM |
465 | static struct ipt_target clusterip_tgt = { |
466 | .name = "CLUSTERIP", | |
467 | .target = target, | |
468 | .targetsize = sizeof(struct ipt_clusterip_tgt_info), | |
469 | .checkentry = checkentry, | |
470 | .destroy = destroy, | |
471 | .me = THIS_MODULE | |
1da177e4 LT |
472 | }; |
473 | ||
474 | ||
475 | /*********************************************************************** | |
476 | * ARP MANGLING CODE | |
477 | ***********************************************************************/ | |
478 | ||
479 | /* hardcoded for 48bit ethernet and 32bit ipv4 addresses */ | |
480 | struct arp_payload { | |
481 | u_int8_t src_hw[ETH_ALEN]; | |
482 | u_int32_t src_ip; | |
483 | u_int8_t dst_hw[ETH_ALEN]; | |
484 | u_int32_t dst_ip; | |
485 | } __attribute__ ((packed)); | |
486 | ||
487 | #ifdef CLUSTERIP_DEBUG | |
488 | static void arp_print(struct arp_payload *payload) | |
489 | { | |
490 | #define HBUFFERLEN 30 | |
491 | char hbuffer[HBUFFERLEN]; | |
492 | int j,k; | |
493 | const char hexbuf[]= "0123456789abcdef"; | |
494 | ||
495 | for (k=0, j=0; k < HBUFFERLEN-3 && j < ETH_ALEN; j++) { | |
496 | hbuffer[k++]=hexbuf[(payload->src_hw[j]>>4)&15]; | |
497 | hbuffer[k++]=hexbuf[payload->src_hw[j]&15]; | |
498 | hbuffer[k++]=':'; | |
499 | } | |
500 | hbuffer[--k]='\0'; | |
501 | ||
502 | printk("src %u.%u.%u.%u@%s, dst %u.%u.%u.%u\n", | |
503 | NIPQUAD(payload->src_ip), hbuffer, | |
504 | NIPQUAD(payload->dst_ip)); | |
505 | } | |
506 | #endif | |
507 | ||
508 | static unsigned int | |
509 | arp_mangle(unsigned int hook, | |
510 | struct sk_buff **pskb, | |
511 | const struct net_device *in, | |
512 | const struct net_device *out, | |
513 | int (*okfn)(struct sk_buff *)) | |
514 | { | |
515 | struct arphdr *arp = (*pskb)->nh.arph; | |
516 | struct arp_payload *payload; | |
517 | struct clusterip_config *c; | |
518 | ||
519 | /* we don't care about non-ethernet and non-ipv4 ARP */ | |
520 | if (arp->ar_hrd != htons(ARPHRD_ETHER) | |
521 | || arp->ar_pro != htons(ETH_P_IP) | |
522 | || arp->ar_pln != 4 || arp->ar_hln != ETH_ALEN) | |
523 | return NF_ACCEPT; | |
524 | ||
4095ebf1 HW |
525 | /* we only want to mangle arp requests and replies */ |
526 | if (arp->ar_op != htons(ARPOP_REPLY) | |
527 | && arp->ar_op != htons(ARPOP_REQUEST)) | |
1da177e4 LT |
528 | return NF_ACCEPT; |
529 | ||
530 | payload = (void *)(arp+1); | |
531 | ||
532 | /* if there is no clusterip configuration for the arp reply's | |
533 | * source ip, we don't want to mangle it */ | |
44513624 | 534 | c = clusterip_config_find_get(payload->src_ip, 0); |
1da177e4 LT |
535 | if (!c) |
536 | return NF_ACCEPT; | |
537 | ||
538 | /* normally the linux kernel always replies to arp queries of | |
539 | * addresses on different interfacs. However, in the CLUSTERIP case | |
540 | * this wouldn't work, since we didn't subscribe the mcast group on | |
541 | * other interfaces */ | |
542 | if (c->dev != out) { | |
543 | DEBUGP("CLUSTERIP: not mangling arp reply on different " | |
544 | "interface: cip'%s'-skb'%s'\n", c->dev->name, out->name); | |
545 | clusterip_config_put(c); | |
546 | return NF_ACCEPT; | |
547 | } | |
548 | ||
549 | /* mangle reply hardware address */ | |
550 | memcpy(payload->src_hw, c->clustermac, arp->ar_hln); | |
551 | ||
552 | #ifdef CLUSTERIP_DEBUG | |
553 | DEBUGP(KERN_DEBUG "CLUSTERIP mangled arp reply: "); | |
554 | arp_print(payload); | |
555 | #endif | |
556 | ||
557 | clusterip_config_put(c); | |
558 | ||
559 | return NF_ACCEPT; | |
560 | } | |
561 | ||
562 | static struct nf_hook_ops cip_arp_ops = { | |
563 | .hook = arp_mangle, | |
564 | .pf = NF_ARP, | |
565 | .hooknum = NF_ARP_OUT, | |
566 | .priority = -1 | |
567 | }; | |
568 | ||
569 | /*********************************************************************** | |
570 | * PROC DIR HANDLING | |
571 | ***********************************************************************/ | |
572 | ||
573 | #ifdef CONFIG_PROC_FS | |
574 | ||
136e92bb KK |
575 | struct clusterip_seq_position { |
576 | unsigned int pos; /* position */ | |
577 | unsigned int weight; /* number of bits set == size */ | |
578 | unsigned int bit; /* current bit */ | |
579 | unsigned long val; /* current value */ | |
580 | }; | |
581 | ||
1da177e4 LT |
582 | static void *clusterip_seq_start(struct seq_file *s, loff_t *pos) |
583 | { | |
584 | struct proc_dir_entry *pde = s->private; | |
585 | struct clusterip_config *c = pde->data; | |
136e92bb KK |
586 | unsigned int weight; |
587 | u_int32_t local_nodes; | |
588 | struct clusterip_seq_position *idx; | |
589 | ||
590 | /* FIXME: possible race */ | |
591 | local_nodes = c->local_nodes; | |
592 | weight = hweight32(local_nodes); | |
593 | if (*pos >= weight) | |
1da177e4 LT |
594 | return NULL; |
595 | ||
136e92bb KK |
596 | idx = kmalloc(sizeof(struct clusterip_seq_position), GFP_KERNEL); |
597 | if (!idx) | |
1da177e4 LT |
598 | return ERR_PTR(-ENOMEM); |
599 | ||
136e92bb KK |
600 | idx->pos = *pos; |
601 | idx->weight = weight; | |
602 | idx->bit = ffs(local_nodes); | |
603 | idx->val = local_nodes; | |
604 | clear_bit(idx->bit - 1, &idx->val); | |
605 | ||
606 | return idx; | |
1da177e4 LT |
607 | } |
608 | ||
609 | static void *clusterip_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
610 | { | |
136e92bb | 611 | struct clusterip_seq_position *idx = (struct clusterip_seq_position *)v; |
1da177e4 | 612 | |
136e92bb KK |
613 | *pos = ++idx->pos; |
614 | if (*pos >= idx->weight) { | |
1da177e4 LT |
615 | kfree(v); |
616 | return NULL; | |
617 | } | |
136e92bb KK |
618 | idx->bit = ffs(idx->val); |
619 | clear_bit(idx->bit - 1, &idx->val); | |
620 | return idx; | |
1da177e4 LT |
621 | } |
622 | ||
623 | static void clusterip_seq_stop(struct seq_file *s, void *v) | |
624 | { | |
625 | kfree(v); | |
1da177e4 LT |
626 | } |
627 | ||
628 | static int clusterip_seq_show(struct seq_file *s, void *v) | |
629 | { | |
136e92bb | 630 | struct clusterip_seq_position *idx = (struct clusterip_seq_position *)v; |
1da177e4 | 631 | |
136e92bb | 632 | if (idx->pos != 0) |
1da177e4 | 633 | seq_putc(s, ','); |
1da177e4 | 634 | |
136e92bb KK |
635 | seq_printf(s, "%u", idx->bit); |
636 | ||
637 | if (idx->pos == idx->weight - 1) | |
1da177e4 LT |
638 | seq_putc(s, '\n'); |
639 | ||
640 | return 0; | |
641 | } | |
642 | ||
643 | static struct seq_operations clusterip_seq_ops = { | |
644 | .start = clusterip_seq_start, | |
645 | .next = clusterip_seq_next, | |
646 | .stop = clusterip_seq_stop, | |
647 | .show = clusterip_seq_show, | |
648 | }; | |
649 | ||
650 | static int clusterip_proc_open(struct inode *inode, struct file *file) | |
651 | { | |
652 | int ret = seq_open(file, &clusterip_seq_ops); | |
653 | ||
654 | if (!ret) { | |
655 | struct seq_file *sf = file->private_data; | |
656 | struct proc_dir_entry *pde = PDE(inode); | |
657 | struct clusterip_config *c = pde->data; | |
658 | ||
659 | sf->private = pde; | |
660 | ||
661 | clusterip_config_get(c); | |
662 | } | |
663 | ||
664 | return ret; | |
665 | } | |
666 | ||
667 | static int clusterip_proc_release(struct inode *inode, struct file *file) | |
668 | { | |
669 | struct proc_dir_entry *pde = PDE(inode); | |
670 | struct clusterip_config *c = pde->data; | |
671 | int ret; | |
672 | ||
673 | ret = seq_release(inode, file); | |
674 | ||
675 | if (!ret) | |
676 | clusterip_config_put(c); | |
677 | ||
678 | return ret; | |
679 | } | |
680 | ||
681 | static ssize_t clusterip_proc_write(struct file *file, const char __user *input, | |
682 | size_t size, loff_t *ofs) | |
683 | { | |
684 | #define PROC_WRITELEN 10 | |
685 | char buffer[PROC_WRITELEN+1]; | |
686 | struct proc_dir_entry *pde = PDE(file->f_dentry->d_inode); | |
687 | struct clusterip_config *c = pde->data; | |
688 | unsigned long nodenum; | |
689 | ||
690 | if (copy_from_user(buffer, input, PROC_WRITELEN)) | |
691 | return -EFAULT; | |
692 | ||
693 | if (*buffer == '+') { | |
694 | nodenum = simple_strtoul(buffer+1, NULL, 10); | |
695 | if (clusterip_add_node(c, nodenum)) | |
696 | return -ENOMEM; | |
697 | } else if (*buffer == '-') { | |
698 | nodenum = simple_strtoul(buffer+1, NULL,10); | |
699 | if (clusterip_del_node(c, nodenum)) | |
700 | return -ENOENT; | |
701 | } else | |
702 | return -EIO; | |
703 | ||
704 | return size; | |
705 | } | |
706 | ||
707 | static struct file_operations clusterip_proc_fops = { | |
708 | .owner = THIS_MODULE, | |
709 | .open = clusterip_proc_open, | |
710 | .read = seq_read, | |
711 | .write = clusterip_proc_write, | |
712 | .llseek = seq_lseek, | |
713 | .release = clusterip_proc_release, | |
714 | }; | |
715 | ||
716 | #endif /* CONFIG_PROC_FS */ | |
717 | ||
32292a7f | 718 | static int __init ipt_clusterip_init(void) |
1da177e4 LT |
719 | { |
720 | int ret; | |
721 | ||
32292a7f PM |
722 | ret = ipt_register_target(&clusterip_tgt); |
723 | if (ret < 0) | |
724 | return ret; | |
1da177e4 | 725 | |
32292a7f PM |
726 | ret = nf_register_hook(&cip_arp_ops); |
727 | if (ret < 0) | |
1da177e4 | 728 | goto cleanup_target; |
1da177e4 LT |
729 | |
730 | #ifdef CONFIG_PROC_FS | |
731 | clusterip_procdir = proc_mkdir("ipt_CLUSTERIP", proc_net); | |
732 | if (!clusterip_procdir) { | |
733 | printk(KERN_ERR "CLUSTERIP: Unable to proc dir entry\n"); | |
734 | ret = -ENOMEM; | |
735 | goto cleanup_hook; | |
736 | } | |
737 | #endif /* CONFIG_PROC_FS */ | |
738 | ||
739 | printk(KERN_NOTICE "ClusterIP Version %s loaded successfully\n", | |
740 | CLUSTERIP_VERSION); | |
1da177e4 LT |
741 | return 0; |
742 | ||
1da177e4 LT |
743 | cleanup_hook: |
744 | nf_unregister_hook(&cip_arp_ops); | |
745 | cleanup_target: | |
746 | ipt_unregister_target(&clusterip_tgt); | |
32292a7f | 747 | return ret; |
1da177e4 LT |
748 | } |
749 | ||
65b4b4e8 | 750 | static void __exit ipt_clusterip_fini(void) |
1da177e4 | 751 | { |
32292a7f PM |
752 | printk(KERN_NOTICE "ClusterIP Version %s unloading\n", |
753 | CLUSTERIP_VERSION); | |
754 | #ifdef CONFIG_PROC_FS | |
755 | remove_proc_entry(clusterip_procdir->name, clusterip_procdir->parent); | |
756 | #endif | |
757 | nf_unregister_hook(&cip_arp_ops); | |
758 | ipt_unregister_target(&clusterip_tgt); | |
1da177e4 LT |
759 | } |
760 | ||
65b4b4e8 AM |
761 | module_init(ipt_clusterip_init); |
762 | module_exit(ipt_clusterip_fini); |