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> | |
1da177e4 | 22 | #include <linux/seq_file.h> |
1da177e4 | 23 | #include <linux/netfilter_arp.h> |
6709dbbb | 24 | #include <linux/netfilter/x_tables.h> |
1da177e4 LT |
25 | #include <linux/netfilter_ipv4/ip_tables.h> |
26 | #include <linux/netfilter_ipv4/ipt_CLUSTERIP.h> | |
587aa641 | 27 | #include <net/netfilter/nf_conntrack.h> |
457c4cbc | 28 | #include <net/net_namespace.h> |
587aa641 | 29 | #include <net/checksum.h> |
1da177e4 | 30 | |
136e92bb | 31 | #define CLUSTERIP_VERSION "0.8" |
1da177e4 | 32 | |
1da177e4 LT |
33 | MODULE_LICENSE("GPL"); |
34 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
35 | MODULE_DESCRIPTION("iptables target for CLUSTERIP"); | |
36 | ||
37 | struct clusterip_config { | |
38 | struct list_head list; /* list of all configs */ | |
39 | atomic_t refcount; /* reference count */ | |
44513624 KK |
40 | atomic_t entries; /* number of entries/rules |
41 | * referencing us */ | |
1da177e4 | 42 | |
6a19d614 | 43 | __be32 clusterip; /* the IP address */ |
1da177e4 LT |
44 | u_int8_t clustermac[ETH_ALEN]; /* the MAC address */ |
45 | struct net_device *dev; /* device */ | |
46 | u_int16_t num_total_nodes; /* total number of nodes */ | |
136e92bb | 47 | unsigned long local_nodes; /* node number array */ |
1da177e4 LT |
48 | |
49 | #ifdef CONFIG_PROC_FS | |
50 | struct proc_dir_entry *pde; /* proc dir entry */ | |
51 | #endif | |
52 | enum clusterip_hashmode hash_mode; /* which hashing mode */ | |
53 | u_int32_t hash_initval; /* hash initialization */ | |
54 | }; | |
55 | ||
56 | static LIST_HEAD(clusterip_configs); | |
57 | ||
136e92bb | 58 | /* clusterip_lock protects the clusterip_configs list */ |
e45b1be8 | 59 | static DEFINE_RWLOCK(clusterip_lock); |
1da177e4 LT |
60 | |
61 | #ifdef CONFIG_PROC_FS | |
9a32144e | 62 | static const struct file_operations clusterip_proc_fops; |
1da177e4 LT |
63 | static struct proc_dir_entry *clusterip_procdir; |
64 | #endif | |
65 | ||
66 | static inline void | |
44513624 KK |
67 | clusterip_config_get(struct clusterip_config *c) |
68 | { | |
1da177e4 LT |
69 | atomic_inc(&c->refcount); |
70 | } | |
71 | ||
72 | static inline void | |
44513624 KK |
73 | clusterip_config_put(struct clusterip_config *c) |
74 | { | |
75 | if (atomic_dec_and_test(&c->refcount)) | |
76 | kfree(c); | |
77 | } | |
78 | ||
79 | /* increase the count of entries(rules) using/referencing this config */ | |
80 | static inline void | |
81 | clusterip_config_entry_get(struct clusterip_config *c) | |
82 | { | |
83 | atomic_inc(&c->entries); | |
84 | } | |
85 | ||
86 | /* decrease the count of entries using/referencing this config. If last | |
87 | * entry(rule) is removed, remove the config from lists, but don't free it | |
88 | * yet, since proc-files could still be holding references */ | |
89 | static inline void | |
90 | clusterip_config_entry_put(struct clusterip_config *c) | |
91 | { | |
92 | if (atomic_dec_and_test(&c->entries)) { | |
e45b1be8 | 93 | write_lock_bh(&clusterip_lock); |
1da177e4 | 94 | list_del(&c->list); |
e45b1be8 | 95 | write_unlock_bh(&clusterip_lock); |
44513624 | 96 | |
1da177e4 LT |
97 | dev_mc_delete(c->dev, c->clustermac, ETH_ALEN, 0); |
98 | dev_put(c->dev); | |
44513624 KK |
99 | |
100 | /* In case anyone still accesses the file, the open/close | |
101 | * functions are also incrementing the refcount on their own, | |
102 | * so it's safe to remove the entry even if it's in use. */ | |
103 | #ifdef CONFIG_PROC_FS | |
104 | remove_proc_entry(c->pde->name, c->pde->parent); | |
105 | #endif | |
1da177e4 LT |
106 | } |
107 | } | |
108 | ||
1da177e4 | 109 | static struct clusterip_config * |
6a19d614 | 110 | __clusterip_config_find(__be32 clusterip) |
1da177e4 | 111 | { |
4c610979 | 112 | struct clusterip_config *c; |
1da177e4 | 113 | |
4c610979 | 114 | list_for_each_entry(c, &clusterip_configs, list) { |
7c4e36bc | 115 | if (c->clusterip == clusterip) |
1da177e4 | 116 | return c; |
1da177e4 LT |
117 | } |
118 | ||
119 | return NULL; | |
120 | } | |
121 | ||
122 | static inline struct clusterip_config * | |
6a19d614 | 123 | clusterip_config_find_get(__be32 clusterip, int entry) |
1da177e4 LT |
124 | { |
125 | struct clusterip_config *c; | |
126 | ||
e45b1be8 | 127 | read_lock_bh(&clusterip_lock); |
1da177e4 LT |
128 | c = __clusterip_config_find(clusterip); |
129 | if (!c) { | |
e45b1be8 | 130 | read_unlock_bh(&clusterip_lock); |
1da177e4 LT |
131 | return NULL; |
132 | } | |
133 | atomic_inc(&c->refcount); | |
44513624 KK |
134 | if (entry) |
135 | atomic_inc(&c->entries); | |
e45b1be8 | 136 | read_unlock_bh(&clusterip_lock); |
1da177e4 LT |
137 | |
138 | return c; | |
139 | } | |
140 | ||
136e92bb KK |
141 | static void |
142 | clusterip_config_init_nodelist(struct clusterip_config *c, | |
143 | const struct ipt_clusterip_tgt_info *i) | |
144 | { | |
145 | int n; | |
146 | ||
7c4e36bc | 147 | for (n = 0; n < i->num_local_nodes; n++) |
136e92bb | 148 | set_bit(i->local_nodes[n] - 1, &c->local_nodes); |
136e92bb KK |
149 | } |
150 | ||
1da177e4 | 151 | static struct clusterip_config * |
6a19d614 | 152 | clusterip_config_init(struct ipt_clusterip_tgt_info *i, __be32 ip, |
1da177e4 LT |
153 | struct net_device *dev) |
154 | { | |
155 | struct clusterip_config *c; | |
1da177e4 | 156 | |
0da974f4 | 157 | c = kzalloc(sizeof(*c), GFP_ATOMIC); |
1da177e4 LT |
158 | if (!c) |
159 | return NULL; | |
160 | ||
1da177e4 LT |
161 | c->dev = dev; |
162 | c->clusterip = ip; | |
163 | memcpy(&c->clustermac, &i->clustermac, ETH_ALEN); | |
164 | c->num_total_nodes = i->num_total_nodes; | |
136e92bb | 165 | clusterip_config_init_nodelist(c, i); |
1da177e4 LT |
166 | c->hash_mode = i->hash_mode; |
167 | c->hash_initval = i->hash_initval; | |
168 | atomic_set(&c->refcount, 1); | |
44513624 | 169 | atomic_set(&c->entries, 1); |
1da177e4 LT |
170 | |
171 | #ifdef CONFIG_PROC_FS | |
76592584 PM |
172 | { |
173 | char buffer[16]; | |
174 | ||
175 | /* create proc dir entry */ | |
176 | sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(ip)); | |
177 | c->pde = create_proc_entry(buffer, S_IWUSR|S_IRUSR, | |
178 | clusterip_procdir); | |
179 | if (!c->pde) { | |
180 | kfree(c); | |
181 | return NULL; | |
182 | } | |
1da177e4 LT |
183 | } |
184 | c->pde->proc_fops = &clusterip_proc_fops; | |
185 | c->pde->data = c; | |
186 | #endif | |
187 | ||
e45b1be8 | 188 | write_lock_bh(&clusterip_lock); |
1da177e4 | 189 | list_add(&c->list, &clusterip_configs); |
e45b1be8 | 190 | write_unlock_bh(&clusterip_lock); |
1da177e4 LT |
191 | |
192 | return c; | |
193 | } | |
194 | ||
76592584 | 195 | #ifdef CONFIG_PROC_FS |
1da177e4 LT |
196 | static int |
197 | clusterip_add_node(struct clusterip_config *c, u_int16_t nodenum) | |
198 | { | |
1da177e4 | 199 | |
136e92bb KK |
200 | if (nodenum == 0 || |
201 | nodenum > c->num_total_nodes) | |
1da177e4 | 202 | return 1; |
1da177e4 | 203 | |
136e92bb KK |
204 | /* check if we already have this number in our bitfield */ |
205 | if (test_and_set_bit(nodenum - 1, &c->local_nodes)) | |
206 | return 1; | |
1da177e4 | 207 | |
1da177e4 LT |
208 | return 0; |
209 | } | |
210 | ||
e1931b78 | 211 | static bool |
1da177e4 LT |
212 | clusterip_del_node(struct clusterip_config *c, u_int16_t nodenum) |
213 | { | |
136e92bb KK |
214 | if (nodenum == 0 || |
215 | nodenum > c->num_total_nodes) | |
e1931b78 | 216 | return true; |
e905a9ed | 217 | |
136e92bb | 218 | if (test_and_clear_bit(nodenum - 1, &c->local_nodes)) |
e1931b78 | 219 | return false; |
1da177e4 | 220 | |
e1931b78 | 221 | return true; |
1da177e4 | 222 | } |
76592584 | 223 | #endif |
1da177e4 LT |
224 | |
225 | static inline u_int32_t | |
a47362a2 JE |
226 | clusterip_hashfn(const struct sk_buff *skb, |
227 | const struct clusterip_config *config) | |
1da177e4 | 228 | { |
a47362a2 | 229 | const struct iphdr *iph = ip_hdr(skb); |
1da177e4 LT |
230 | unsigned long hashval; |
231 | u_int16_t sport, dport; | |
a47362a2 | 232 | const u_int16_t *ports; |
1da177e4 LT |
233 | |
234 | switch (iph->protocol) { | |
235 | case IPPROTO_TCP: | |
1da177e4 | 236 | case IPPROTO_UDP: |
a8d0f952 | 237 | case IPPROTO_UDPLITE: |
957dc80a PM |
238 | case IPPROTO_SCTP: |
239 | case IPPROTO_DCCP: | |
1da177e4 | 240 | case IPPROTO_ICMP: |
a47362a2 | 241 | ports = (const void *)iph+iph->ihl*4; |
957dc80a PM |
242 | sport = ports[0]; |
243 | dport = ports[1]; | |
1da177e4 LT |
244 | break; |
245 | default: | |
7c4e36bc | 246 | if (net_ratelimit()) |
1da177e4 LT |
247 | printk(KERN_NOTICE "CLUSTERIP: unknown protocol `%u'\n", |
248 | iph->protocol); | |
1da177e4 LT |
249 | sport = dport = 0; |
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: | |
e905a9ed | 258 | hashval = jhash_2words(ntohl(iph->saddr), sport, |
1da177e4 LT |
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 | printk("CLUSTERIP: unknown mode `%u'\n", config->hash_mode); | |
271 | BUG(); | |
272 | break; | |
273 | } | |
274 | ||
275 | /* node numbers are 1..n, not 0..n */ | |
7c4e36bc | 276 | return (hashval % config->num_total_nodes) + 1; |
1da177e4 LT |
277 | } |
278 | ||
279 | static inline int | |
a47362a2 | 280 | clusterip_responsible(const struct clusterip_config *config, u_int32_t hash) |
1da177e4 | 281 | { |
136e92bb | 282 | return test_bit(hash - 1, &config->local_nodes); |
1da177e4 LT |
283 | } |
284 | ||
e905a9ed YH |
285 | /*********************************************************************** |
286 | * IPTABLES TARGET | |
1da177e4 LT |
287 | ***********************************************************************/ |
288 | ||
289 | static unsigned int | |
3db05fea | 290 | target(struct sk_buff *skb, |
1da177e4 LT |
291 | const struct net_device *in, |
292 | const struct net_device *out, | |
293 | unsigned int hooknum, | |
c4986734 | 294 | const struct xt_target *target, |
fe1cb108 | 295 | const void *targinfo) |
1da177e4 LT |
296 | { |
297 | const struct ipt_clusterip_tgt_info *cipinfo = targinfo; | |
587aa641 | 298 | struct nf_conn *ct; |
1da177e4 | 299 | enum ip_conntrack_info ctinfo; |
587aa641 | 300 | u_int32_t hash; |
1da177e4 LT |
301 | |
302 | /* don't need to clusterip_config_get() here, since refcount | |
303 | * is only decremented by destroy() - and ip_tables guarantees | |
304 | * that the ->target() function isn't called after ->destroy() */ | |
305 | ||
3db05fea | 306 | ct = nf_ct_get(skb, &ctinfo); |
587aa641 | 307 | if (ct == NULL) { |
1da177e4 LT |
308 | printk(KERN_ERR "CLUSTERIP: no conntrack!\n"); |
309 | /* FIXME: need to drop invalid ones, since replies | |
e905a9ed | 310 | * to outgoing connections of other nodes will be |
1da177e4 LT |
311 | * marked as INVALID */ |
312 | return NF_DROP; | |
313 | } | |
314 | ||
315 | /* special case: ICMP error handling. conntrack distinguishes between | |
316 | * error messages (RELATED) and information requests (see below) */ | |
3db05fea | 317 | if (ip_hdr(skb)->protocol == IPPROTO_ICMP |
e905a9ed | 318 | && (ctinfo == IP_CT_RELATED |
5d927eb0 | 319 | || ctinfo == IP_CT_RELATED+IP_CT_IS_REPLY)) |
6709dbbb | 320 | return XT_CONTINUE; |
1da177e4 | 321 | |
e905a9ed | 322 | /* ip_conntrack_icmp guarantees us that we only have ICMP_ECHO, |
1da177e4 LT |
323 | * TIMESTAMP, INFO_REQUEST or ADDRESS type icmp packets from here |
324 | * on, which all have an ID field [relevant for hashing]. */ | |
325 | ||
3db05fea | 326 | hash = clusterip_hashfn(skb, cipinfo->config); |
1da177e4 LT |
327 | |
328 | switch (ctinfo) { | |
329 | case IP_CT_NEW: | |
587aa641 | 330 | ct->mark = hash; |
1da177e4 LT |
331 | break; |
332 | case IP_CT_RELATED: | |
333 | case IP_CT_RELATED+IP_CT_IS_REPLY: | |
334 | /* FIXME: we don't handle expectations at the | |
335 | * moment. they can arrive on a different node than | |
336 | * the master connection (e.g. FTP passive mode) */ | |
337 | case IP_CT_ESTABLISHED: | |
338 | case IP_CT_ESTABLISHED+IP_CT_IS_REPLY: | |
339 | break; | |
340 | default: | |
341 | break; | |
342 | } | |
343 | ||
0d53778e | 344 | #ifdef DEBUG |
1da177e4 LT |
345 | DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); |
346 | #endif | |
0d53778e | 347 | pr_debug("hash=%u ct_hash=%u ", hash, ct->mark); |
1da177e4 | 348 | if (!clusterip_responsible(cipinfo->config, hash)) { |
0d53778e | 349 | pr_debug("not responsible\n"); |
1da177e4 LT |
350 | return NF_DROP; |
351 | } | |
0d53778e | 352 | pr_debug("responsible\n"); |
1da177e4 LT |
353 | |
354 | /* despite being received via linklayer multicast, this is | |
355 | * actually a unicast IP packet. TCP doesn't like PACKET_MULTICAST */ | |
3db05fea | 356 | skb->pkt_type = PACKET_HOST; |
1da177e4 | 357 | |
6709dbbb | 358 | return XT_CONTINUE; |
1da177e4 LT |
359 | } |
360 | ||
e1931b78 | 361 | static bool |
1da177e4 | 362 | checkentry(const char *tablename, |
2e4e6a17 | 363 | const void *e_void, |
c4986734 | 364 | const struct xt_target *target, |
e905a9ed YH |
365 | void *targinfo, |
366 | unsigned int hook_mask) | |
1da177e4 LT |
367 | { |
368 | struct ipt_clusterip_tgt_info *cipinfo = targinfo; | |
2e4e6a17 | 369 | const struct ipt_entry *e = e_void; |
1da177e4 LT |
370 | |
371 | struct clusterip_config *config; | |
372 | ||
1da177e4 LT |
373 | if (cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP && |
374 | cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT && | |
375 | cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT_DPT) { | |
376 | printk(KERN_WARNING "CLUSTERIP: unknown mode `%u'\n", | |
377 | cipinfo->hash_mode); | |
e1931b78 | 378 | return false; |
1da177e4 LT |
379 | |
380 | } | |
6a19d614 | 381 | if (e->ip.dmsk.s_addr != htonl(0xffffffff) |
1da177e4 LT |
382 | || e->ip.dst.s_addr == 0) { |
383 | printk(KERN_ERR "CLUSTERIP: Please specify destination IP\n"); | |
e1931b78 | 384 | return false; |
1da177e4 LT |
385 | } |
386 | ||
387 | /* FIXME: further sanity checks */ | |
388 | ||
44513624 | 389 | config = clusterip_config_find_get(e->ip.dst.s_addr, 1); |
d3c3f424 | 390 | if (!config) { |
1da177e4 LT |
391 | if (!(cipinfo->flags & CLUSTERIP_FLAG_NEW)) { |
392 | printk(KERN_WARNING "CLUSTERIP: no config found for %u.%u.%u.%u, need 'new'\n", NIPQUAD(e->ip.dst.s_addr)); | |
e1931b78 | 393 | return false; |
1da177e4 LT |
394 | } else { |
395 | struct net_device *dev; | |
396 | ||
397 | if (e->ip.iniface[0] == '\0') { | |
398 | printk(KERN_WARNING "CLUSTERIP: Please specify an interface name\n"); | |
e1931b78 | 399 | return false; |
1da177e4 LT |
400 | } |
401 | ||
881d966b | 402 | dev = dev_get_by_name(&init_net, e->ip.iniface); |
1da177e4 LT |
403 | if (!dev) { |
404 | printk(KERN_WARNING "CLUSTERIP: no such interface %s\n", e->ip.iniface); | |
e1931b78 | 405 | return false; |
1da177e4 LT |
406 | } |
407 | ||
e905a9ed | 408 | config = clusterip_config_init(cipinfo, |
1da177e4 LT |
409 | e->ip.dst.s_addr, dev); |
410 | if (!config) { | |
411 | printk(KERN_WARNING "CLUSTERIP: cannot allocate config\n"); | |
412 | dev_put(dev); | |
e1931b78 | 413 | return false; |
1da177e4 LT |
414 | } |
415 | dev_mc_add(config->dev,config->clustermac, ETH_ALEN, 0); | |
416 | } | |
417 | } | |
d3c3f424 | 418 | cipinfo->config = config; |
1da177e4 | 419 | |
11078c37 YK |
420 | if (nf_ct_l3proto_try_module_get(target->family) < 0) { |
421 | printk(KERN_WARNING "can't load conntrack support for " | |
422 | "proto=%d\n", target->family); | |
e1931b78 | 423 | return false; |
11078c37 YK |
424 | } |
425 | ||
e1931b78 | 426 | return true; |
1da177e4 LT |
427 | } |
428 | ||
429 | /* drop reference count of cluster config when rule is deleted */ | |
efa74165 | 430 | static void destroy(const struct xt_target *target, void *targinfo) |
1da177e4 | 431 | { |
c4986734 | 432 | struct ipt_clusterip_tgt_info *cipinfo = targinfo; |
1da177e4 | 433 | |
44513624 KK |
434 | /* if no more entries are referencing the config, remove it |
435 | * from the list and destroy the proc entry */ | |
436 | clusterip_config_entry_put(cipinfo->config); | |
437 | ||
1da177e4 | 438 | clusterip_config_put(cipinfo->config); |
11078c37 YK |
439 | |
440 | nf_ct_l3proto_module_put(target->family); | |
1da177e4 LT |
441 | } |
442 | ||
d3c3f424 PM |
443 | #ifdef CONFIG_COMPAT |
444 | struct compat_ipt_clusterip_tgt_info | |
445 | { | |
446 | u_int32_t flags; | |
447 | u_int8_t clustermac[6]; | |
448 | u_int16_t num_total_nodes; | |
449 | u_int16_t num_local_nodes; | |
450 | u_int16_t local_nodes[CLUSTERIP_MAX_NODES]; | |
451 | u_int32_t hash_mode; | |
452 | u_int32_t hash_initval; | |
453 | compat_uptr_t config; | |
454 | }; | |
455 | #endif /* CONFIG_COMPAT */ | |
456 | ||
9f15c530 | 457 | static struct xt_target clusterip_tgt __read_mostly = { |
1d5cd909 | 458 | .name = "CLUSTERIP", |
6709dbbb | 459 | .family = AF_INET, |
1d5cd909 | 460 | .target = target, |
1d5cd909 PM |
461 | .checkentry = checkentry, |
462 | .destroy = destroy, | |
d3c3f424 PM |
463 | .targetsize = sizeof(struct ipt_clusterip_tgt_info), |
464 | #ifdef CONFIG_COMPAT | |
465 | .compatsize = sizeof(struct compat_ipt_clusterip_tgt_info), | |
466 | #endif /* CONFIG_COMPAT */ | |
1d5cd909 | 467 | .me = THIS_MODULE |
1da177e4 LT |
468 | }; |
469 | ||
470 | ||
e905a9ed YH |
471 | /*********************************************************************** |
472 | * ARP MANGLING CODE | |
1da177e4 LT |
473 | ***********************************************************************/ |
474 | ||
475 | /* hardcoded for 48bit ethernet and 32bit ipv4 addresses */ | |
476 | struct arp_payload { | |
477 | u_int8_t src_hw[ETH_ALEN]; | |
6a19d614 | 478 | __be32 src_ip; |
1da177e4 | 479 | u_int8_t dst_hw[ETH_ALEN]; |
6a19d614 | 480 | __be32 dst_ip; |
1da177e4 LT |
481 | } __attribute__ ((packed)); |
482 | ||
0d53778e | 483 | #ifdef DEBUG |
e905a9ed | 484 | static void arp_print(struct arp_payload *payload) |
1da177e4 LT |
485 | { |
486 | #define HBUFFERLEN 30 | |
487 | char hbuffer[HBUFFERLEN]; | |
488 | int j,k; | |
489 | const char hexbuf[]= "0123456789abcdef"; | |
490 | ||
491 | for (k=0, j=0; k < HBUFFERLEN-3 && j < ETH_ALEN; j++) { | |
492 | hbuffer[k++]=hexbuf[(payload->src_hw[j]>>4)&15]; | |
493 | hbuffer[k++]=hexbuf[payload->src_hw[j]&15]; | |
494 | hbuffer[k++]=':'; | |
495 | } | |
496 | hbuffer[--k]='\0'; | |
497 | ||
e905a9ed | 498 | printk("src %u.%u.%u.%u@%s, dst %u.%u.%u.%u\n", |
1da177e4 LT |
499 | NIPQUAD(payload->src_ip), hbuffer, |
500 | NIPQUAD(payload->dst_ip)); | |
501 | } | |
502 | #endif | |
503 | ||
504 | static unsigned int | |
505 | arp_mangle(unsigned int hook, | |
3db05fea | 506 | struct sk_buff *skb, |
1da177e4 LT |
507 | const struct net_device *in, |
508 | const struct net_device *out, | |
509 | int (*okfn)(struct sk_buff *)) | |
510 | { | |
3db05fea | 511 | struct arphdr *arp = arp_hdr(skb); |
1da177e4 LT |
512 | struct arp_payload *payload; |
513 | struct clusterip_config *c; | |
514 | ||
515 | /* we don't care about non-ethernet and non-ipv4 ARP */ | |
516 | if (arp->ar_hrd != htons(ARPHRD_ETHER) | |
517 | || arp->ar_pro != htons(ETH_P_IP) | |
518 | || arp->ar_pln != 4 || arp->ar_hln != ETH_ALEN) | |
519 | return NF_ACCEPT; | |
520 | ||
4095ebf1 HW |
521 | /* we only want to mangle arp requests and replies */ |
522 | if (arp->ar_op != htons(ARPOP_REPLY) | |
523 | && arp->ar_op != htons(ARPOP_REQUEST)) | |
1da177e4 LT |
524 | return NF_ACCEPT; |
525 | ||
526 | payload = (void *)(arp+1); | |
527 | ||
e905a9ed | 528 | /* if there is no clusterip configuration for the arp reply's |
1da177e4 | 529 | * source ip, we don't want to mangle it */ |
44513624 | 530 | c = clusterip_config_find_get(payload->src_ip, 0); |
1da177e4 LT |
531 | if (!c) |
532 | return NF_ACCEPT; | |
533 | ||
e905a9ed | 534 | /* normally the linux kernel always replies to arp queries of |
1da177e4 LT |
535 | * addresses on different interfacs. However, in the CLUSTERIP case |
536 | * this wouldn't work, since we didn't subscribe the mcast group on | |
537 | * other interfaces */ | |
538 | if (c->dev != out) { | |
0d53778e PM |
539 | pr_debug("CLUSTERIP: not mangling arp reply on different " |
540 | "interface: cip'%s'-skb'%s'\n", | |
541 | c->dev->name, out->name); | |
1da177e4 LT |
542 | clusterip_config_put(c); |
543 | return NF_ACCEPT; | |
544 | } | |
545 | ||
546 | /* mangle reply hardware address */ | |
547 | memcpy(payload->src_hw, c->clustermac, arp->ar_hln); | |
548 | ||
0d53778e PM |
549 | #ifdef DEBUG |
550 | pr_debug(KERN_DEBUG "CLUSTERIP mangled arp reply: "); | |
1da177e4 LT |
551 | arp_print(payload); |
552 | #endif | |
553 | ||
554 | clusterip_config_put(c); | |
555 | ||
556 | return NF_ACCEPT; | |
557 | } | |
558 | ||
559 | static struct nf_hook_ops cip_arp_ops = { | |
560 | .hook = arp_mangle, | |
561 | .pf = NF_ARP, | |
562 | .hooknum = NF_ARP_OUT, | |
563 | .priority = -1 | |
564 | }; | |
565 | ||
e905a9ed YH |
566 | /*********************************************************************** |
567 | * PROC DIR HANDLING | |
1da177e4 LT |
568 | ***********************************************************************/ |
569 | ||
570 | #ifdef CONFIG_PROC_FS | |
571 | ||
136e92bb KK |
572 | struct clusterip_seq_position { |
573 | unsigned int pos; /* position */ | |
574 | unsigned int weight; /* number of bits set == size */ | |
575 | unsigned int bit; /* current bit */ | |
576 | unsigned long val; /* current value */ | |
577 | }; | |
578 | ||
1da177e4 LT |
579 | static void *clusterip_seq_start(struct seq_file *s, loff_t *pos) |
580 | { | |
581 | struct proc_dir_entry *pde = s->private; | |
582 | struct clusterip_config *c = pde->data; | |
136e92bb KK |
583 | unsigned int weight; |
584 | u_int32_t local_nodes; | |
585 | struct clusterip_seq_position *idx; | |
586 | ||
587 | /* FIXME: possible race */ | |
588 | local_nodes = c->local_nodes; | |
589 | weight = hweight32(local_nodes); | |
590 | if (*pos >= weight) | |
1da177e4 LT |
591 | return NULL; |
592 | ||
136e92bb KK |
593 | idx = kmalloc(sizeof(struct clusterip_seq_position), GFP_KERNEL); |
594 | if (!idx) | |
1da177e4 LT |
595 | return ERR_PTR(-ENOMEM); |
596 | ||
136e92bb KK |
597 | idx->pos = *pos; |
598 | idx->weight = weight; | |
599 | idx->bit = ffs(local_nodes); | |
600 | idx->val = local_nodes; | |
601 | clear_bit(idx->bit - 1, &idx->val); | |
602 | ||
603 | return idx; | |
1da177e4 LT |
604 | } |
605 | ||
606 | static void *clusterip_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
607 | { | |
136e92bb | 608 | struct clusterip_seq_position *idx = (struct clusterip_seq_position *)v; |
1da177e4 | 609 | |
136e92bb KK |
610 | *pos = ++idx->pos; |
611 | if (*pos >= idx->weight) { | |
1da177e4 LT |
612 | kfree(v); |
613 | return NULL; | |
614 | } | |
136e92bb KK |
615 | idx->bit = ffs(idx->val); |
616 | clear_bit(idx->bit - 1, &idx->val); | |
617 | return idx; | |
1da177e4 LT |
618 | } |
619 | ||
620 | static void clusterip_seq_stop(struct seq_file *s, void *v) | |
621 | { | |
622 | kfree(v); | |
1da177e4 LT |
623 | } |
624 | ||
625 | static int clusterip_seq_show(struct seq_file *s, void *v) | |
626 | { | |
136e92bb | 627 | struct clusterip_seq_position *idx = (struct clusterip_seq_position *)v; |
1da177e4 | 628 | |
e905a9ed | 629 | if (idx->pos != 0) |
1da177e4 | 630 | seq_putc(s, ','); |
1da177e4 | 631 | |
136e92bb KK |
632 | seq_printf(s, "%u", idx->bit); |
633 | ||
634 | if (idx->pos == idx->weight - 1) | |
1da177e4 LT |
635 | seq_putc(s, '\n'); |
636 | ||
637 | return 0; | |
638 | } | |
639 | ||
56b3d975 | 640 | static const struct seq_operations clusterip_seq_ops = { |
1da177e4 LT |
641 | .start = clusterip_seq_start, |
642 | .next = clusterip_seq_next, | |
643 | .stop = clusterip_seq_stop, | |
644 | .show = clusterip_seq_show, | |
645 | }; | |
646 | ||
647 | static int clusterip_proc_open(struct inode *inode, struct file *file) | |
648 | { | |
649 | int ret = seq_open(file, &clusterip_seq_ops); | |
650 | ||
651 | if (!ret) { | |
652 | struct seq_file *sf = file->private_data; | |
653 | struct proc_dir_entry *pde = PDE(inode); | |
654 | struct clusterip_config *c = pde->data; | |
655 | ||
656 | sf->private = pde; | |
657 | ||
658 | clusterip_config_get(c); | |
659 | } | |
660 | ||
661 | return ret; | |
662 | } | |
663 | ||
664 | static int clusterip_proc_release(struct inode *inode, struct file *file) | |
665 | { | |
666 | struct proc_dir_entry *pde = PDE(inode); | |
667 | struct clusterip_config *c = pde->data; | |
668 | int ret; | |
669 | ||
670 | ret = seq_release(inode, file); | |
671 | ||
672 | if (!ret) | |
673 | clusterip_config_put(c); | |
674 | ||
675 | return ret; | |
676 | } | |
677 | ||
678 | static ssize_t clusterip_proc_write(struct file *file, const char __user *input, | |
679 | size_t size, loff_t *ofs) | |
680 | { | |
681 | #define PROC_WRITELEN 10 | |
682 | char buffer[PROC_WRITELEN+1]; | |
6df81ab2 | 683 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); |
1da177e4 LT |
684 | struct clusterip_config *c = pde->data; |
685 | unsigned long nodenum; | |
686 | ||
687 | if (copy_from_user(buffer, input, PROC_WRITELEN)) | |
688 | return -EFAULT; | |
689 | ||
690 | if (*buffer == '+') { | |
691 | nodenum = simple_strtoul(buffer+1, NULL, 10); | |
692 | if (clusterip_add_node(c, nodenum)) | |
693 | return -ENOMEM; | |
694 | } else if (*buffer == '-') { | |
695 | nodenum = simple_strtoul(buffer+1, NULL,10); | |
696 | if (clusterip_del_node(c, nodenum)) | |
697 | return -ENOENT; | |
698 | } else | |
699 | return -EIO; | |
700 | ||
701 | return size; | |
702 | } | |
703 | ||
9a32144e | 704 | static const struct file_operations clusterip_proc_fops = { |
1da177e4 LT |
705 | .owner = THIS_MODULE, |
706 | .open = clusterip_proc_open, | |
707 | .read = seq_read, | |
708 | .write = clusterip_proc_write, | |
709 | .llseek = seq_lseek, | |
710 | .release = clusterip_proc_release, | |
711 | }; | |
712 | ||
713 | #endif /* CONFIG_PROC_FS */ | |
714 | ||
32292a7f | 715 | static int __init ipt_clusterip_init(void) |
1da177e4 LT |
716 | { |
717 | int ret; | |
718 | ||
6709dbbb | 719 | ret = xt_register_target(&clusterip_tgt); |
32292a7f PM |
720 | if (ret < 0) |
721 | return ret; | |
1da177e4 | 722 | |
32292a7f PM |
723 | ret = nf_register_hook(&cip_arp_ops); |
724 | if (ret < 0) | |
1da177e4 | 725 | goto cleanup_target; |
1da177e4 LT |
726 | |
727 | #ifdef CONFIG_PROC_FS | |
457c4cbc | 728 | clusterip_procdir = proc_mkdir("ipt_CLUSTERIP", init_net.proc_net); |
1da177e4 LT |
729 | if (!clusterip_procdir) { |
730 | printk(KERN_ERR "CLUSTERIP: Unable to proc dir entry\n"); | |
731 | ret = -ENOMEM; | |
732 | goto cleanup_hook; | |
733 | } | |
734 | #endif /* CONFIG_PROC_FS */ | |
735 | ||
736 | printk(KERN_NOTICE "ClusterIP Version %s loaded successfully\n", | |
737 | CLUSTERIP_VERSION); | |
1da177e4 LT |
738 | return 0; |
739 | ||
76592584 | 740 | #ifdef CONFIG_PROC_FS |
1da177e4 LT |
741 | cleanup_hook: |
742 | nf_unregister_hook(&cip_arp_ops); | |
76592584 | 743 | #endif /* CONFIG_PROC_FS */ |
1da177e4 | 744 | cleanup_target: |
6709dbbb | 745 | xt_unregister_target(&clusterip_tgt); |
32292a7f | 746 | return ret; |
1da177e4 LT |
747 | } |
748 | ||
65b4b4e8 | 749 | static void __exit ipt_clusterip_fini(void) |
1da177e4 | 750 | { |
32292a7f PM |
751 | printk(KERN_NOTICE "ClusterIP Version %s unloading\n", |
752 | CLUSTERIP_VERSION); | |
753 | #ifdef CONFIG_PROC_FS | |
754 | remove_proc_entry(clusterip_procdir->name, clusterip_procdir->parent); | |
755 | #endif | |
756 | nf_unregister_hook(&cip_arp_ops); | |
6709dbbb | 757 | xt_unregister_target(&clusterip_tgt); |
1da177e4 LT |
758 | } |
759 | ||
65b4b4e8 AM |
760 | module_init(ipt_clusterip_init); |
761 | module_exit(ipt_clusterip_fini); |