Commit | Line | Data |
---|---|---|
e905a9ed | 1 | /* Cluster IP hashmark target |
1da177e4 LT |
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> | |
1da177e4 | 24 | #include <linux/netfilter_arp.h> |
6709dbbb | 25 | #include <linux/netfilter/x_tables.h> |
1da177e4 LT |
26 | #include <linux/netfilter_ipv4/ip_tables.h> |
27 | #include <linux/netfilter_ipv4/ipt_CLUSTERIP.h> | |
587aa641 PM |
28 | #include <net/netfilter/nf_conntrack.h> |
29 | #include <net/checksum.h> | |
1da177e4 | 30 | |
136e92bb | 31 | #define CLUSTERIP_VERSION "0.8" |
1da177e4 LT |
32 | |
33 | #define DEBUG_CLUSTERIP | |
34 | ||
35 | #ifdef DEBUG_CLUSTERIP | |
36 | #define DEBUGP printk | |
37 | #else | |
38 | #define DEBUGP | |
39 | #endif | |
40 | ||
41 | MODULE_LICENSE("GPL"); | |
42 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
43 | MODULE_DESCRIPTION("iptables target for CLUSTERIP"); | |
44 | ||
45 | struct clusterip_config { | |
46 | struct list_head list; /* list of all configs */ | |
47 | atomic_t refcount; /* reference count */ | |
44513624 KK |
48 | atomic_t entries; /* number of entries/rules |
49 | * referencing us */ | |
1da177e4 | 50 | |
6a19d614 | 51 | __be32 clusterip; /* the IP address */ |
1da177e4 LT |
52 | u_int8_t clustermac[ETH_ALEN]; /* the MAC address */ |
53 | struct net_device *dev; /* device */ | |
54 | u_int16_t num_total_nodes; /* total number of nodes */ | |
136e92bb | 55 | unsigned long local_nodes; /* node number array */ |
1da177e4 LT |
56 | |
57 | #ifdef CONFIG_PROC_FS | |
58 | struct proc_dir_entry *pde; /* proc dir entry */ | |
59 | #endif | |
60 | enum clusterip_hashmode hash_mode; /* which hashing mode */ | |
61 | u_int32_t hash_initval; /* hash initialization */ | |
62 | }; | |
63 | ||
64 | static LIST_HEAD(clusterip_configs); | |
65 | ||
136e92bb | 66 | /* clusterip_lock protects the clusterip_configs list */ |
e45b1be8 | 67 | static DEFINE_RWLOCK(clusterip_lock); |
1da177e4 LT |
68 | |
69 | #ifdef CONFIG_PROC_FS | |
9a32144e | 70 | static const struct file_operations clusterip_proc_fops; |
1da177e4 LT |
71 | static struct proc_dir_entry *clusterip_procdir; |
72 | #endif | |
73 | ||
74 | static inline void | |
44513624 KK |
75 | clusterip_config_get(struct clusterip_config *c) |
76 | { | |
1da177e4 LT |
77 | atomic_inc(&c->refcount); |
78 | } | |
79 | ||
80 | static inline void | |
44513624 KK |
81 | clusterip_config_put(struct clusterip_config *c) |
82 | { | |
83 | if (atomic_dec_and_test(&c->refcount)) | |
84 | kfree(c); | |
85 | } | |
86 | ||
87 | /* increase the count of entries(rules) using/referencing this config */ | |
88 | static inline void | |
89 | clusterip_config_entry_get(struct clusterip_config *c) | |
90 | { | |
91 | atomic_inc(&c->entries); | |
92 | } | |
93 | ||
94 | /* decrease the count of entries using/referencing this config. If last | |
95 | * entry(rule) is removed, remove the config from lists, but don't free it | |
96 | * yet, since proc-files could still be holding references */ | |
97 | static inline void | |
98 | clusterip_config_entry_put(struct clusterip_config *c) | |
99 | { | |
100 | if (atomic_dec_and_test(&c->entries)) { | |
e45b1be8 | 101 | write_lock_bh(&clusterip_lock); |
1da177e4 | 102 | list_del(&c->list); |
e45b1be8 | 103 | write_unlock_bh(&clusterip_lock); |
44513624 | 104 | |
1da177e4 LT |
105 | dev_mc_delete(c->dev, c->clustermac, ETH_ALEN, 0); |
106 | dev_put(c->dev); | |
44513624 KK |
107 | |
108 | /* In case anyone still accesses the file, the open/close | |
109 | * functions are also incrementing the refcount on their own, | |
110 | * so it's safe to remove the entry even if it's in use. */ | |
111 | #ifdef CONFIG_PROC_FS | |
112 | remove_proc_entry(c->pde->name, c->pde->parent); | |
113 | #endif | |
1da177e4 LT |
114 | } |
115 | } | |
116 | ||
1da177e4 | 117 | static struct clusterip_config * |
6a19d614 | 118 | __clusterip_config_find(__be32 clusterip) |
1da177e4 LT |
119 | { |
120 | struct list_head *pos; | |
121 | ||
1da177e4 | 122 | list_for_each(pos, &clusterip_configs) { |
e905a9ed | 123 | struct clusterip_config *c = list_entry(pos, |
1da177e4 | 124 | struct clusterip_config, list); |
7c4e36bc | 125 | if (c->clusterip == clusterip) |
1da177e4 | 126 | return c; |
1da177e4 LT |
127 | } |
128 | ||
129 | return NULL; | |
130 | } | |
131 | ||
132 | static inline struct clusterip_config * | |
6a19d614 | 133 | clusterip_config_find_get(__be32 clusterip, int entry) |
1da177e4 LT |
134 | { |
135 | struct clusterip_config *c; | |
136 | ||
e45b1be8 | 137 | read_lock_bh(&clusterip_lock); |
1da177e4 LT |
138 | c = __clusterip_config_find(clusterip); |
139 | if (!c) { | |
e45b1be8 | 140 | read_unlock_bh(&clusterip_lock); |
1da177e4 LT |
141 | return NULL; |
142 | } | |
143 | atomic_inc(&c->refcount); | |
44513624 KK |
144 | if (entry) |
145 | atomic_inc(&c->entries); | |
e45b1be8 | 146 | read_unlock_bh(&clusterip_lock); |
1da177e4 LT |
147 | |
148 | return c; | |
149 | } | |
150 | ||
136e92bb KK |
151 | static void |
152 | clusterip_config_init_nodelist(struct clusterip_config *c, | |
153 | const struct ipt_clusterip_tgt_info *i) | |
154 | { | |
155 | int n; | |
156 | ||
7c4e36bc | 157 | for (n = 0; n < i->num_local_nodes; n++) |
136e92bb | 158 | set_bit(i->local_nodes[n] - 1, &c->local_nodes); |
136e92bb KK |
159 | } |
160 | ||
1da177e4 | 161 | static struct clusterip_config * |
6a19d614 | 162 | clusterip_config_init(struct ipt_clusterip_tgt_info *i, __be32 ip, |
1da177e4 LT |
163 | struct net_device *dev) |
164 | { | |
165 | struct clusterip_config *c; | |
1da177e4 | 166 | |
0da974f4 | 167 | c = kzalloc(sizeof(*c), GFP_ATOMIC); |
1da177e4 LT |
168 | if (!c) |
169 | return NULL; | |
170 | ||
1da177e4 LT |
171 | c->dev = dev; |
172 | c->clusterip = ip; | |
173 | memcpy(&c->clustermac, &i->clustermac, ETH_ALEN); | |
174 | c->num_total_nodes = i->num_total_nodes; | |
136e92bb | 175 | clusterip_config_init_nodelist(c, i); |
1da177e4 LT |
176 | c->hash_mode = i->hash_mode; |
177 | c->hash_initval = i->hash_initval; | |
178 | atomic_set(&c->refcount, 1); | |
44513624 | 179 | atomic_set(&c->entries, 1); |
1da177e4 LT |
180 | |
181 | #ifdef CONFIG_PROC_FS | |
76592584 PM |
182 | { |
183 | char buffer[16]; | |
184 | ||
185 | /* create proc dir entry */ | |
186 | sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(ip)); | |
187 | c->pde = create_proc_entry(buffer, S_IWUSR|S_IRUSR, | |
188 | clusterip_procdir); | |
189 | if (!c->pde) { | |
190 | kfree(c); | |
191 | return NULL; | |
192 | } | |
1da177e4 LT |
193 | } |
194 | c->pde->proc_fops = &clusterip_proc_fops; | |
195 | c->pde->data = c; | |
196 | #endif | |
197 | ||
e45b1be8 | 198 | write_lock_bh(&clusterip_lock); |
1da177e4 | 199 | list_add(&c->list, &clusterip_configs); |
e45b1be8 | 200 | write_unlock_bh(&clusterip_lock); |
1da177e4 LT |
201 | |
202 | return c; | |
203 | } | |
204 | ||
76592584 | 205 | #ifdef CONFIG_PROC_FS |
1da177e4 LT |
206 | static int |
207 | clusterip_add_node(struct clusterip_config *c, u_int16_t nodenum) | |
208 | { | |
1da177e4 | 209 | |
136e92bb KK |
210 | if (nodenum == 0 || |
211 | nodenum > c->num_total_nodes) | |
1da177e4 | 212 | return 1; |
1da177e4 | 213 | |
136e92bb KK |
214 | /* check if we already have this number in our bitfield */ |
215 | if (test_and_set_bit(nodenum - 1, &c->local_nodes)) | |
216 | return 1; | |
1da177e4 | 217 | |
1da177e4 LT |
218 | return 0; |
219 | } | |
220 | ||
e1931b78 | 221 | static bool |
1da177e4 LT |
222 | clusterip_del_node(struct clusterip_config *c, u_int16_t nodenum) |
223 | { | |
136e92bb KK |
224 | if (nodenum == 0 || |
225 | nodenum > c->num_total_nodes) | |
e1931b78 | 226 | return true; |
e905a9ed | 227 | |
136e92bb | 228 | if (test_and_clear_bit(nodenum - 1, &c->local_nodes)) |
e1931b78 | 229 | return false; |
1da177e4 | 230 | |
e1931b78 | 231 | return true; |
1da177e4 | 232 | } |
76592584 | 233 | #endif |
1da177e4 LT |
234 | |
235 | static inline u_int32_t | |
a47362a2 JE |
236 | clusterip_hashfn(const struct sk_buff *skb, |
237 | const struct clusterip_config *config) | |
1da177e4 | 238 | { |
a47362a2 | 239 | const struct iphdr *iph = ip_hdr(skb); |
1da177e4 LT |
240 | unsigned long hashval; |
241 | u_int16_t sport, dport; | |
a47362a2 | 242 | const u_int16_t *ports; |
1da177e4 LT |
243 | |
244 | switch (iph->protocol) { | |
245 | case IPPROTO_TCP: | |
1da177e4 | 246 | case IPPROTO_UDP: |
a8d0f952 | 247 | case IPPROTO_UDPLITE: |
957dc80a PM |
248 | case IPPROTO_SCTP: |
249 | case IPPROTO_DCCP: | |
1da177e4 | 250 | case IPPROTO_ICMP: |
a47362a2 | 251 | ports = (const void *)iph+iph->ihl*4; |
957dc80a PM |
252 | sport = ports[0]; |
253 | dport = ports[1]; | |
1da177e4 LT |
254 | break; |
255 | default: | |
7c4e36bc | 256 | if (net_ratelimit()) |
1da177e4 LT |
257 | printk(KERN_NOTICE "CLUSTERIP: unknown protocol `%u'\n", |
258 | iph->protocol); | |
1da177e4 LT |
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: | |
e905a9ed | 268 | hashval = jhash_2words(ntohl(iph->saddr), sport, |
1da177e4 LT |
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 */ | |
7c4e36bc | 286 | return (hashval % config->num_total_nodes) + 1; |
1da177e4 LT |
287 | } |
288 | ||
289 | static inline int | |
a47362a2 | 290 | clusterip_responsible(const struct clusterip_config *config, u_int32_t hash) |
1da177e4 | 291 | { |
136e92bb | 292 | return test_bit(hash - 1, &config->local_nodes); |
1da177e4 LT |
293 | } |
294 | ||
e905a9ed YH |
295 | /*********************************************************************** |
296 | * IPTABLES TARGET | |
1da177e4 LT |
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, |
fe1cb108 | 305 | const void *targinfo) |
1da177e4 LT |
306 | { |
307 | const struct ipt_clusterip_tgt_info *cipinfo = targinfo; | |
587aa641 | 308 | struct nf_conn *ct; |
1da177e4 | 309 | enum ip_conntrack_info ctinfo; |
587aa641 | 310 | u_int32_t 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 | ||
587aa641 PM |
316 | ct = nf_ct_get(*pskb, &ctinfo); |
317 | if (ct == NULL) { | |
1da177e4 LT |
318 | printk(KERN_ERR "CLUSTERIP: no conntrack!\n"); |
319 | /* FIXME: need to drop invalid ones, since replies | |
e905a9ed | 320 | * to outgoing connections of other nodes will be |
1da177e4 LT |
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) */ | |
eddc9ec5 | 327 | if (ip_hdr(*pskb)->protocol == IPPROTO_ICMP |
e905a9ed | 328 | && (ctinfo == IP_CT_RELATED |
5d927eb0 | 329 | || ctinfo == IP_CT_RELATED+IP_CT_IS_REPLY)) |
6709dbbb | 330 | return XT_CONTINUE; |
1da177e4 | 331 | |
e905a9ed | 332 | /* ip_conntrack_icmp guarantees us that we only have ICMP_ECHO, |
1da177e4 LT |
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: | |
587aa641 | 340 | ct->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 | |
587aa641 | 357 | DEBUGP("hash=%u ct_hash=%u ", hash, ct->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 | ||
6709dbbb | 368 | return XT_CONTINUE; |
1da177e4 LT |
369 | } |
370 | ||
e1931b78 | 371 | static bool |
1da177e4 | 372 | checkentry(const char *tablename, |
2e4e6a17 | 373 | const void *e_void, |
c4986734 | 374 | const struct xt_target *target, |
e905a9ed YH |
375 | void *targinfo, |
376 | unsigned int hook_mask) | |
1da177e4 LT |
377 | { |
378 | struct ipt_clusterip_tgt_info *cipinfo = targinfo; | |
2e4e6a17 | 379 | const struct ipt_entry *e = e_void; |
1da177e4 LT |
380 | |
381 | struct clusterip_config *config; | |
382 | ||
1da177e4 LT |
383 | if (cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP && |
384 | cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT && | |
385 | cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT_DPT) { | |
386 | printk(KERN_WARNING "CLUSTERIP: unknown mode `%u'\n", | |
387 | cipinfo->hash_mode); | |
e1931b78 | 388 | return false; |
1da177e4 LT |
389 | |
390 | } | |
6a19d614 | 391 | if (e->ip.dmsk.s_addr != htonl(0xffffffff) |
1da177e4 LT |
392 | || e->ip.dst.s_addr == 0) { |
393 | printk(KERN_ERR "CLUSTERIP: Please specify destination IP\n"); | |
e1931b78 | 394 | return false; |
1da177e4 LT |
395 | } |
396 | ||
397 | /* FIXME: further sanity checks */ | |
398 | ||
44513624 KK |
399 | config = clusterip_config_find_get(e->ip.dst.s_addr, 1); |
400 | if (config) { | |
401 | if (cipinfo->config != NULL) { | |
402 | /* Case A: This is an entry that gets reloaded, since | |
403 | * it still has a cipinfo->config pointer. Simply | |
404 | * increase the entry refcount and return */ | |
405 | if (cipinfo->config != config) { | |
406 | printk(KERN_ERR "CLUSTERIP: Reloaded entry " | |
407 | "has invalid config pointer!\n"); | |
e1931b78 | 408 | return false; |
44513624 | 409 | } |
44513624 KK |
410 | } else { |
411 | /* Case B: This is a new rule referring to an existing | |
412 | * clusterip config. */ | |
413 | cipinfo->config = config; | |
44513624 KK |
414 | } |
415 | } else { | |
416 | /* Case C: This is a completely new clusterip config */ | |
1da177e4 LT |
417 | if (!(cipinfo->flags & CLUSTERIP_FLAG_NEW)) { |
418 | printk(KERN_WARNING "CLUSTERIP: no config found for %u.%u.%u.%u, need 'new'\n", NIPQUAD(e->ip.dst.s_addr)); | |
e1931b78 | 419 | return false; |
1da177e4 LT |
420 | } else { |
421 | struct net_device *dev; | |
422 | ||
423 | if (e->ip.iniface[0] == '\0') { | |
424 | printk(KERN_WARNING "CLUSTERIP: Please specify an interface name\n"); | |
e1931b78 | 425 | return false; |
1da177e4 LT |
426 | } |
427 | ||
428 | dev = dev_get_by_name(e->ip.iniface); | |
429 | if (!dev) { | |
430 | printk(KERN_WARNING "CLUSTERIP: no such interface %s\n", e->ip.iniface); | |
e1931b78 | 431 | return false; |
1da177e4 LT |
432 | } |
433 | ||
e905a9ed | 434 | config = clusterip_config_init(cipinfo, |
1da177e4 LT |
435 | e->ip.dst.s_addr, dev); |
436 | if (!config) { | |
437 | printk(KERN_WARNING "CLUSTERIP: cannot allocate config\n"); | |
438 | dev_put(dev); | |
e1931b78 | 439 | return false; |
1da177e4 LT |
440 | } |
441 | dev_mc_add(config->dev,config->clustermac, ETH_ALEN, 0); | |
442 | } | |
44513624 | 443 | cipinfo->config = config; |
1da177e4 LT |
444 | } |
445 | ||
11078c37 YK |
446 | if (nf_ct_l3proto_try_module_get(target->family) < 0) { |
447 | printk(KERN_WARNING "can't load conntrack support for " | |
448 | "proto=%d\n", target->family); | |
e1931b78 | 449 | return false; |
11078c37 YK |
450 | } |
451 | ||
e1931b78 | 452 | return true; |
1da177e4 LT |
453 | } |
454 | ||
455 | /* drop reference count of cluster config when rule is deleted */ | |
efa74165 | 456 | static void destroy(const struct xt_target *target, void *targinfo) |
1da177e4 | 457 | { |
c4986734 | 458 | struct ipt_clusterip_tgt_info *cipinfo = targinfo; |
1da177e4 | 459 | |
44513624 KK |
460 | /* if no more entries are referencing the config, remove it |
461 | * from the list and destroy the proc entry */ | |
462 | clusterip_config_entry_put(cipinfo->config); | |
463 | ||
1da177e4 | 464 | clusterip_config_put(cipinfo->config); |
11078c37 YK |
465 | |
466 | nf_ct_l3proto_module_put(target->family); | |
1da177e4 LT |
467 | } |
468 | ||
9f15c530 | 469 | static struct xt_target clusterip_tgt __read_mostly = { |
1d5cd909 | 470 | .name = "CLUSTERIP", |
6709dbbb | 471 | .family = AF_INET, |
1d5cd909 PM |
472 | .target = target, |
473 | .targetsize = sizeof(struct ipt_clusterip_tgt_info), | |
474 | .checkentry = checkentry, | |
475 | .destroy = destroy, | |
476 | .me = THIS_MODULE | |
1da177e4 LT |
477 | }; |
478 | ||
479 | ||
e905a9ed YH |
480 | /*********************************************************************** |
481 | * ARP MANGLING CODE | |
1da177e4 LT |
482 | ***********************************************************************/ |
483 | ||
484 | /* hardcoded for 48bit ethernet and 32bit ipv4 addresses */ | |
485 | struct arp_payload { | |
486 | u_int8_t src_hw[ETH_ALEN]; | |
6a19d614 | 487 | __be32 src_ip; |
1da177e4 | 488 | u_int8_t dst_hw[ETH_ALEN]; |
6a19d614 | 489 | __be32 dst_ip; |
1da177e4 LT |
490 | } __attribute__ ((packed)); |
491 | ||
492 | #ifdef CLUSTERIP_DEBUG | |
e905a9ed | 493 | static void arp_print(struct arp_payload *payload) |
1da177e4 LT |
494 | { |
495 | #define HBUFFERLEN 30 | |
496 | char hbuffer[HBUFFERLEN]; | |
497 | int j,k; | |
498 | const char hexbuf[]= "0123456789abcdef"; | |
499 | ||
500 | for (k=0, j=0; k < HBUFFERLEN-3 && j < ETH_ALEN; j++) { | |
501 | hbuffer[k++]=hexbuf[(payload->src_hw[j]>>4)&15]; | |
502 | hbuffer[k++]=hexbuf[payload->src_hw[j]&15]; | |
503 | hbuffer[k++]=':'; | |
504 | } | |
505 | hbuffer[--k]='\0'; | |
506 | ||
e905a9ed | 507 | printk("src %u.%u.%u.%u@%s, dst %u.%u.%u.%u\n", |
1da177e4 LT |
508 | NIPQUAD(payload->src_ip), hbuffer, |
509 | NIPQUAD(payload->dst_ip)); | |
510 | } | |
511 | #endif | |
512 | ||
513 | static unsigned int | |
514 | arp_mangle(unsigned int hook, | |
515 | struct sk_buff **pskb, | |
516 | const struct net_device *in, | |
517 | const struct net_device *out, | |
518 | int (*okfn)(struct sk_buff *)) | |
519 | { | |
d0a92be0 | 520 | struct arphdr *arp = arp_hdr(*pskb); |
1da177e4 LT |
521 | struct arp_payload *payload; |
522 | struct clusterip_config *c; | |
523 | ||
524 | /* we don't care about non-ethernet and non-ipv4 ARP */ | |
525 | if (arp->ar_hrd != htons(ARPHRD_ETHER) | |
526 | || arp->ar_pro != htons(ETH_P_IP) | |
527 | || arp->ar_pln != 4 || arp->ar_hln != ETH_ALEN) | |
528 | return NF_ACCEPT; | |
529 | ||
4095ebf1 HW |
530 | /* we only want to mangle arp requests and replies */ |
531 | if (arp->ar_op != htons(ARPOP_REPLY) | |
532 | && arp->ar_op != htons(ARPOP_REQUEST)) | |
1da177e4 LT |
533 | return NF_ACCEPT; |
534 | ||
535 | payload = (void *)(arp+1); | |
536 | ||
e905a9ed | 537 | /* if there is no clusterip configuration for the arp reply's |
1da177e4 | 538 | * source ip, we don't want to mangle it */ |
44513624 | 539 | c = clusterip_config_find_get(payload->src_ip, 0); |
1da177e4 LT |
540 | if (!c) |
541 | return NF_ACCEPT; | |
542 | ||
e905a9ed | 543 | /* normally the linux kernel always replies to arp queries of |
1da177e4 LT |
544 | * addresses on different interfacs. However, in the CLUSTERIP case |
545 | * this wouldn't work, since we didn't subscribe the mcast group on | |
546 | * other interfaces */ | |
547 | if (c->dev != out) { | |
548 | DEBUGP("CLUSTERIP: not mangling arp reply on different " | |
549 | "interface: cip'%s'-skb'%s'\n", c->dev->name, out->name); | |
550 | clusterip_config_put(c); | |
551 | return NF_ACCEPT; | |
552 | } | |
553 | ||
554 | /* mangle reply hardware address */ | |
555 | memcpy(payload->src_hw, c->clustermac, arp->ar_hln); | |
556 | ||
557 | #ifdef CLUSTERIP_DEBUG | |
558 | DEBUGP(KERN_DEBUG "CLUSTERIP mangled arp reply: "); | |
559 | arp_print(payload); | |
560 | #endif | |
561 | ||
562 | clusterip_config_put(c); | |
563 | ||
564 | return NF_ACCEPT; | |
565 | } | |
566 | ||
567 | static struct nf_hook_ops cip_arp_ops = { | |
568 | .hook = arp_mangle, | |
569 | .pf = NF_ARP, | |
570 | .hooknum = NF_ARP_OUT, | |
571 | .priority = -1 | |
572 | }; | |
573 | ||
e905a9ed YH |
574 | /*********************************************************************** |
575 | * PROC DIR HANDLING | |
1da177e4 LT |
576 | ***********************************************************************/ |
577 | ||
578 | #ifdef CONFIG_PROC_FS | |
579 | ||
136e92bb KK |
580 | struct clusterip_seq_position { |
581 | unsigned int pos; /* position */ | |
582 | unsigned int weight; /* number of bits set == size */ | |
583 | unsigned int bit; /* current bit */ | |
584 | unsigned long val; /* current value */ | |
585 | }; | |
586 | ||
1da177e4 LT |
587 | static void *clusterip_seq_start(struct seq_file *s, loff_t *pos) |
588 | { | |
589 | struct proc_dir_entry *pde = s->private; | |
590 | struct clusterip_config *c = pde->data; | |
136e92bb KK |
591 | unsigned int weight; |
592 | u_int32_t local_nodes; | |
593 | struct clusterip_seq_position *idx; | |
594 | ||
595 | /* FIXME: possible race */ | |
596 | local_nodes = c->local_nodes; | |
597 | weight = hweight32(local_nodes); | |
598 | if (*pos >= weight) | |
1da177e4 LT |
599 | return NULL; |
600 | ||
136e92bb KK |
601 | idx = kmalloc(sizeof(struct clusterip_seq_position), GFP_KERNEL); |
602 | if (!idx) | |
1da177e4 LT |
603 | return ERR_PTR(-ENOMEM); |
604 | ||
136e92bb KK |
605 | idx->pos = *pos; |
606 | idx->weight = weight; | |
607 | idx->bit = ffs(local_nodes); | |
608 | idx->val = local_nodes; | |
609 | clear_bit(idx->bit - 1, &idx->val); | |
610 | ||
611 | return idx; | |
1da177e4 LT |
612 | } |
613 | ||
614 | static void *clusterip_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
615 | { | |
136e92bb | 616 | struct clusterip_seq_position *idx = (struct clusterip_seq_position *)v; |
1da177e4 | 617 | |
136e92bb KK |
618 | *pos = ++idx->pos; |
619 | if (*pos >= idx->weight) { | |
1da177e4 LT |
620 | kfree(v); |
621 | return NULL; | |
622 | } | |
136e92bb KK |
623 | idx->bit = ffs(idx->val); |
624 | clear_bit(idx->bit - 1, &idx->val); | |
625 | return idx; | |
1da177e4 LT |
626 | } |
627 | ||
628 | static void clusterip_seq_stop(struct seq_file *s, void *v) | |
629 | { | |
630 | kfree(v); | |
1da177e4 LT |
631 | } |
632 | ||
633 | static int clusterip_seq_show(struct seq_file *s, void *v) | |
634 | { | |
136e92bb | 635 | struct clusterip_seq_position *idx = (struct clusterip_seq_position *)v; |
1da177e4 | 636 | |
e905a9ed | 637 | if (idx->pos != 0) |
1da177e4 | 638 | seq_putc(s, ','); |
1da177e4 | 639 | |
136e92bb KK |
640 | seq_printf(s, "%u", idx->bit); |
641 | ||
642 | if (idx->pos == idx->weight - 1) | |
1da177e4 LT |
643 | seq_putc(s, '\n'); |
644 | ||
645 | return 0; | |
646 | } | |
647 | ||
648 | static struct seq_operations clusterip_seq_ops = { | |
649 | .start = clusterip_seq_start, | |
650 | .next = clusterip_seq_next, | |
651 | .stop = clusterip_seq_stop, | |
652 | .show = clusterip_seq_show, | |
653 | }; | |
654 | ||
655 | static int clusterip_proc_open(struct inode *inode, struct file *file) | |
656 | { | |
657 | int ret = seq_open(file, &clusterip_seq_ops); | |
658 | ||
659 | if (!ret) { | |
660 | struct seq_file *sf = file->private_data; | |
661 | struct proc_dir_entry *pde = PDE(inode); | |
662 | struct clusterip_config *c = pde->data; | |
663 | ||
664 | sf->private = pde; | |
665 | ||
666 | clusterip_config_get(c); | |
667 | } | |
668 | ||
669 | return ret; | |
670 | } | |
671 | ||
672 | static int clusterip_proc_release(struct inode *inode, struct file *file) | |
673 | { | |
674 | struct proc_dir_entry *pde = PDE(inode); | |
675 | struct clusterip_config *c = pde->data; | |
676 | int ret; | |
677 | ||
678 | ret = seq_release(inode, file); | |
679 | ||
680 | if (!ret) | |
681 | clusterip_config_put(c); | |
682 | ||
683 | return ret; | |
684 | } | |
685 | ||
686 | static ssize_t clusterip_proc_write(struct file *file, const char __user *input, | |
687 | size_t size, loff_t *ofs) | |
688 | { | |
689 | #define PROC_WRITELEN 10 | |
690 | char buffer[PROC_WRITELEN+1]; | |
6df81ab2 | 691 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); |
1da177e4 LT |
692 | struct clusterip_config *c = pde->data; |
693 | unsigned long nodenum; | |
694 | ||
695 | if (copy_from_user(buffer, input, PROC_WRITELEN)) | |
696 | return -EFAULT; | |
697 | ||
698 | if (*buffer == '+') { | |
699 | nodenum = simple_strtoul(buffer+1, NULL, 10); | |
700 | if (clusterip_add_node(c, nodenum)) | |
701 | return -ENOMEM; | |
702 | } else if (*buffer == '-') { | |
703 | nodenum = simple_strtoul(buffer+1, NULL,10); | |
704 | if (clusterip_del_node(c, nodenum)) | |
705 | return -ENOENT; | |
706 | } else | |
707 | return -EIO; | |
708 | ||
709 | return size; | |
710 | } | |
711 | ||
9a32144e | 712 | static const struct file_operations clusterip_proc_fops = { |
1da177e4 LT |
713 | .owner = THIS_MODULE, |
714 | .open = clusterip_proc_open, | |
715 | .read = seq_read, | |
716 | .write = clusterip_proc_write, | |
717 | .llseek = seq_lseek, | |
718 | .release = clusterip_proc_release, | |
719 | }; | |
720 | ||
721 | #endif /* CONFIG_PROC_FS */ | |
722 | ||
32292a7f | 723 | static int __init ipt_clusterip_init(void) |
1da177e4 LT |
724 | { |
725 | int ret; | |
726 | ||
6709dbbb | 727 | ret = xt_register_target(&clusterip_tgt); |
32292a7f PM |
728 | if (ret < 0) |
729 | return ret; | |
1da177e4 | 730 | |
32292a7f PM |
731 | ret = nf_register_hook(&cip_arp_ops); |
732 | if (ret < 0) | |
1da177e4 | 733 | goto cleanup_target; |
1da177e4 LT |
734 | |
735 | #ifdef CONFIG_PROC_FS | |
736 | clusterip_procdir = proc_mkdir("ipt_CLUSTERIP", proc_net); | |
737 | if (!clusterip_procdir) { | |
738 | printk(KERN_ERR "CLUSTERIP: Unable to proc dir entry\n"); | |
739 | ret = -ENOMEM; | |
740 | goto cleanup_hook; | |
741 | } | |
742 | #endif /* CONFIG_PROC_FS */ | |
743 | ||
744 | printk(KERN_NOTICE "ClusterIP Version %s loaded successfully\n", | |
745 | CLUSTERIP_VERSION); | |
1da177e4 LT |
746 | return 0; |
747 | ||
76592584 | 748 | #ifdef CONFIG_PROC_FS |
1da177e4 LT |
749 | cleanup_hook: |
750 | nf_unregister_hook(&cip_arp_ops); | |
76592584 | 751 | #endif /* CONFIG_PROC_FS */ |
1da177e4 | 752 | cleanup_target: |
6709dbbb | 753 | xt_unregister_target(&clusterip_tgt); |
32292a7f | 754 | return ret; |
1da177e4 LT |
755 | } |
756 | ||
65b4b4e8 | 757 | static void __exit ipt_clusterip_fini(void) |
1da177e4 | 758 | { |
32292a7f PM |
759 | printk(KERN_NOTICE "ClusterIP Version %s unloading\n", |
760 | CLUSTERIP_VERSION); | |
761 | #ifdef CONFIG_PROC_FS | |
762 | remove_proc_entry(clusterip_procdir->name, clusterip_procdir->parent); | |
763 | #endif | |
764 | nf_unregister_hook(&cip_arp_ops); | |
6709dbbb | 765 | xt_unregister_target(&clusterip_tgt); |
1da177e4 LT |
766 | } |
767 | ||
65b4b4e8 AM |
768 | module_init(ipt_clusterip_init); |
769 | module_exit(ipt_clusterip_fini); |