Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
| 13 | #include <linux/config.h> |
| 14 | #include <linux/proc_fs.h> |
| 15 | #include <linux/jhash.h> |
| 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> |
| 31 | #include <linux/netfilter_ipv4/ip_conntrack.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
| 33 | #define CLUSTERIP_VERSION "0.6" |
| 34 | |
| 35 | #define DEBUG_CLUSTERIP |
| 36 | |
| 37 | #ifdef DEBUG_CLUSTERIP |
| 38 | #define DEBUGP printk |
| 39 | #else |
| 40 | #define DEBUGP |
| 41 | #endif |
| 42 | |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 43 | #define ASSERT_READ_LOCK(x) |
| 44 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 */ |
| 52 | |
| 53 | u_int32_t clusterip; /* the IP address */ |
| 54 | u_int8_t clustermac[ETH_ALEN]; /* the MAC address */ |
| 55 | struct net_device *dev; /* device */ |
| 56 | u_int16_t num_total_nodes; /* total number of nodes */ |
| 57 | u_int16_t num_local_nodes; /* number of local nodes */ |
| 58 | u_int16_t local_nodes[CLUSTERIP_MAX_NODES]; /* node number array */ |
| 59 | |
| 60 | #ifdef CONFIG_PROC_FS |
| 61 | struct proc_dir_entry *pde; /* proc dir entry */ |
| 62 | #endif |
| 63 | enum clusterip_hashmode hash_mode; /* which hashing mode */ |
| 64 | u_int32_t hash_initval; /* hash initialization */ |
| 65 | }; |
| 66 | |
| 67 | static LIST_HEAD(clusterip_configs); |
| 68 | |
| 69 | /* clusterip_lock protects the clusterip_configs list _AND_ the configurable |
| 70 | * data within all structurses (num_local_nodes, local_nodes[]) */ |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 71 | static DEFINE_RWLOCK(clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 |
| 79 | clusterip_config_get(struct clusterip_config *c) { |
| 80 | atomic_inc(&c->refcount); |
| 81 | } |
| 82 | |
| 83 | static inline void |
| 84 | clusterip_config_put(struct clusterip_config *c) { |
| 85 | if (atomic_dec_and_test(&c->refcount)) { |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 86 | write_lock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | list_del(&c->list); |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 88 | write_unlock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | dev_mc_delete(c->dev, c->clustermac, ETH_ALEN, 0); |
| 90 | dev_put(c->dev); |
| 91 | kfree(c); |
| 92 | } |
| 93 | } |
| 94 | |
| 95 | |
| 96 | static struct clusterip_config * |
| 97 | __clusterip_config_find(u_int32_t clusterip) |
| 98 | { |
| 99 | struct list_head *pos; |
| 100 | |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 101 | ASSERT_READ_LOCK(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | list_for_each(pos, &clusterip_configs) { |
| 103 | struct clusterip_config *c = list_entry(pos, |
| 104 | struct clusterip_config, list); |
| 105 | if (c->clusterip == clusterip) { |
| 106 | return c; |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | return NULL; |
| 111 | } |
| 112 | |
| 113 | static inline struct clusterip_config * |
| 114 | clusterip_config_find_get(u_int32_t clusterip) |
| 115 | { |
| 116 | struct clusterip_config *c; |
| 117 | |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 118 | read_lock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | c = __clusterip_config_find(clusterip); |
| 120 | if (!c) { |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 121 | read_unlock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | return NULL; |
| 123 | } |
| 124 | atomic_inc(&c->refcount); |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 125 | read_unlock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | |
| 127 | return c; |
| 128 | } |
| 129 | |
| 130 | static struct clusterip_config * |
| 131 | clusterip_config_init(struct ipt_clusterip_tgt_info *i, u_int32_t ip, |
| 132 | struct net_device *dev) |
| 133 | { |
| 134 | struct clusterip_config *c; |
| 135 | char buffer[16]; |
| 136 | |
| 137 | c = kmalloc(sizeof(*c), GFP_ATOMIC); |
| 138 | if (!c) |
| 139 | return NULL; |
| 140 | |
| 141 | memset(c, 0, sizeof(*c)); |
| 142 | c->dev = dev; |
| 143 | c->clusterip = ip; |
| 144 | memcpy(&c->clustermac, &i->clustermac, ETH_ALEN); |
| 145 | c->num_total_nodes = i->num_total_nodes; |
| 146 | c->num_local_nodes = i->num_local_nodes; |
| 147 | memcpy(&c->local_nodes, &i->local_nodes, sizeof(&c->local_nodes)); |
| 148 | c->hash_mode = i->hash_mode; |
| 149 | c->hash_initval = i->hash_initval; |
| 150 | atomic_set(&c->refcount, 1); |
| 151 | |
| 152 | #ifdef CONFIG_PROC_FS |
| 153 | /* create proc dir entry */ |
| 154 | sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(ip)); |
| 155 | c->pde = create_proc_entry(buffer, S_IWUSR|S_IRUSR, clusterip_procdir); |
| 156 | if (!c->pde) { |
| 157 | kfree(c); |
| 158 | return NULL; |
| 159 | } |
| 160 | c->pde->proc_fops = &clusterip_proc_fops; |
| 161 | c->pde->data = c; |
| 162 | #endif |
| 163 | |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 164 | write_lock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | list_add(&c->list, &clusterip_configs); |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 166 | write_unlock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | |
| 168 | return c; |
| 169 | } |
| 170 | |
| 171 | static int |
| 172 | clusterip_add_node(struct clusterip_config *c, u_int16_t nodenum) |
| 173 | { |
| 174 | int i; |
| 175 | |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 176 | write_lock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | |
| 178 | if (c->num_local_nodes >= CLUSTERIP_MAX_NODES |
| 179 | || nodenum > CLUSTERIP_MAX_NODES) { |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 180 | write_unlock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | return 1; |
| 182 | } |
| 183 | |
| 184 | /* check if we alrady have this number in our array */ |
| 185 | for (i = 0; i < c->num_local_nodes; i++) { |
| 186 | if (c->local_nodes[i] == nodenum) { |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 187 | write_unlock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | return 1; |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | c->local_nodes[c->num_local_nodes++] = nodenum; |
| 193 | |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 194 | write_unlock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | return 0; |
| 196 | } |
| 197 | |
| 198 | static int |
| 199 | clusterip_del_node(struct clusterip_config *c, u_int16_t nodenum) |
| 200 | { |
| 201 | int i; |
| 202 | |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 203 | write_lock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | |
| 205 | if (c->num_local_nodes <= 1 || nodenum > CLUSTERIP_MAX_NODES) { |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 206 | write_unlock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | return 1; |
| 208 | } |
| 209 | |
| 210 | for (i = 0; i < c->num_local_nodes; i++) { |
| 211 | if (c->local_nodes[i] == nodenum) { |
| 212 | int size = sizeof(u_int16_t)*(c->num_local_nodes-(i+1)); |
| 213 | memmove(&c->local_nodes[i], &c->local_nodes[i+1], size); |
| 214 | c->num_local_nodes--; |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 215 | write_unlock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | return 0; |
| 217 | } |
| 218 | } |
| 219 | |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 220 | write_unlock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | return 1; |
| 222 | } |
| 223 | |
| 224 | static inline u_int32_t |
| 225 | clusterip_hashfn(struct sk_buff *skb, struct clusterip_config *config) |
| 226 | { |
| 227 | struct iphdr *iph = skb->nh.iph; |
| 228 | unsigned long hashval; |
| 229 | u_int16_t sport, dport; |
| 230 | struct tcphdr *th; |
| 231 | struct udphdr *uh; |
| 232 | struct icmphdr *ih; |
| 233 | |
| 234 | switch (iph->protocol) { |
| 235 | case IPPROTO_TCP: |
| 236 | th = (void *)iph+iph->ihl*4; |
| 237 | sport = ntohs(th->source); |
| 238 | dport = ntohs(th->dest); |
| 239 | break; |
| 240 | case IPPROTO_UDP: |
| 241 | uh = (void *)iph+iph->ihl*4; |
| 242 | sport = ntohs(uh->source); |
| 243 | dport = ntohs(uh->dest); |
| 244 | break; |
| 245 | case IPPROTO_ICMP: |
| 246 | ih = (void *)iph+iph->ihl*4; |
| 247 | sport = ntohs(ih->un.echo.id); |
| 248 | dport = (ih->type<<8)|ih->code; |
| 249 | break; |
| 250 | default: |
| 251 | if (net_ratelimit()) { |
| 252 | printk(KERN_NOTICE "CLUSTERIP: unknown protocol `%u'\n", |
| 253 | iph->protocol); |
| 254 | } |
| 255 | sport = dport = 0; |
| 256 | } |
| 257 | |
| 258 | switch (config->hash_mode) { |
| 259 | case CLUSTERIP_HASHMODE_SIP: |
| 260 | hashval = jhash_1word(ntohl(iph->saddr), |
| 261 | config->hash_initval); |
| 262 | break; |
| 263 | case CLUSTERIP_HASHMODE_SIP_SPT: |
| 264 | hashval = jhash_2words(ntohl(iph->saddr), sport, |
| 265 | config->hash_initval); |
| 266 | break; |
| 267 | case CLUSTERIP_HASHMODE_SIP_SPT_DPT: |
| 268 | hashval = jhash_3words(ntohl(iph->saddr), sport, dport, |
| 269 | config->hash_initval); |
| 270 | break; |
| 271 | default: |
| 272 | /* to make gcc happy */ |
| 273 | hashval = 0; |
| 274 | /* This cannot happen, unless the check function wasn't called |
| 275 | * at rule load time */ |
| 276 | printk("CLUSTERIP: unknown mode `%u'\n", config->hash_mode); |
| 277 | BUG(); |
| 278 | break; |
| 279 | } |
| 280 | |
| 281 | /* node numbers are 1..n, not 0..n */ |
| 282 | return ((hashval % config->num_total_nodes)+1); |
| 283 | } |
| 284 | |
| 285 | static inline int |
| 286 | clusterip_responsible(struct clusterip_config *config, u_int32_t hash) |
| 287 | { |
| 288 | int i; |
| 289 | |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 290 | read_lock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | |
| 292 | if (config->num_local_nodes == 0) { |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 293 | read_unlock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 294 | return 0; |
| 295 | } |
| 296 | |
| 297 | for (i = 0; i < config->num_local_nodes; i++) { |
| 298 | if (config->local_nodes[i] == hash) { |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 299 | read_unlock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | return 1; |
| 301 | } |
| 302 | } |
| 303 | |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 304 | read_unlock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 305 | |
| 306 | return 0; |
| 307 | } |
| 308 | |
| 309 | /*********************************************************************** |
| 310 | * IPTABLES TARGET |
| 311 | ***********************************************************************/ |
| 312 | |
| 313 | static unsigned int |
| 314 | target(struct sk_buff **pskb, |
| 315 | const struct net_device *in, |
| 316 | const struct net_device *out, |
| 317 | unsigned int hooknum, |
| 318 | const void *targinfo, |
| 319 | void *userinfo) |
| 320 | { |
| 321 | const struct ipt_clusterip_tgt_info *cipinfo = targinfo; |
| 322 | enum ip_conntrack_info ctinfo; |
| 323 | struct ip_conntrack *ct = ip_conntrack_get((*pskb), &ctinfo); |
| 324 | u_int32_t hash; |
| 325 | |
| 326 | /* don't need to clusterip_config_get() here, since refcount |
| 327 | * is only decremented by destroy() - and ip_tables guarantees |
| 328 | * that the ->target() function isn't called after ->destroy() */ |
| 329 | |
| 330 | if (!ct) { |
| 331 | printk(KERN_ERR "CLUSTERIP: no conntrack!\n"); |
| 332 | /* FIXME: need to drop invalid ones, since replies |
| 333 | * to outgoing connections of other nodes will be |
| 334 | * marked as INVALID */ |
| 335 | return NF_DROP; |
| 336 | } |
| 337 | |
| 338 | /* special case: ICMP error handling. conntrack distinguishes between |
| 339 | * error messages (RELATED) and information requests (see below) */ |
| 340 | if ((*pskb)->nh.iph->protocol == IPPROTO_ICMP |
| 341 | && (ctinfo == IP_CT_RELATED |
| 342 | || ctinfo == IP_CT_IS_REPLY+IP_CT_IS_REPLY)) |
| 343 | return IPT_CONTINUE; |
| 344 | |
| 345 | /* ip_conntrack_icmp guarantees us that we only have ICMP_ECHO, |
| 346 | * TIMESTAMP, INFO_REQUEST or ADDRESS type icmp packets from here |
| 347 | * on, which all have an ID field [relevant for hashing]. */ |
| 348 | |
| 349 | hash = clusterip_hashfn(*pskb, cipinfo->config); |
| 350 | |
| 351 | switch (ctinfo) { |
| 352 | case IP_CT_NEW: |
| 353 | ct->mark = hash; |
| 354 | break; |
| 355 | case IP_CT_RELATED: |
| 356 | case IP_CT_RELATED+IP_CT_IS_REPLY: |
| 357 | /* FIXME: we don't handle expectations at the |
| 358 | * moment. they can arrive on a different node than |
| 359 | * the master connection (e.g. FTP passive mode) */ |
| 360 | case IP_CT_ESTABLISHED: |
| 361 | case IP_CT_ESTABLISHED+IP_CT_IS_REPLY: |
| 362 | break; |
| 363 | default: |
| 364 | break; |
| 365 | } |
| 366 | |
| 367 | #ifdef DEBUG_CLUSTERP |
| 368 | DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); |
| 369 | #endif |
| 370 | DEBUGP("hash=%u ct_hash=%lu ", hash, ct->mark); |
| 371 | if (!clusterip_responsible(cipinfo->config, hash)) { |
| 372 | DEBUGP("not responsible\n"); |
| 373 | return NF_DROP; |
| 374 | } |
| 375 | DEBUGP("responsible\n"); |
| 376 | |
| 377 | /* despite being received via linklayer multicast, this is |
| 378 | * actually a unicast IP packet. TCP doesn't like PACKET_MULTICAST */ |
| 379 | (*pskb)->pkt_type = PACKET_HOST; |
| 380 | |
| 381 | return IPT_CONTINUE; |
| 382 | } |
| 383 | |
| 384 | static int |
| 385 | checkentry(const char *tablename, |
| 386 | const struct ipt_entry *e, |
| 387 | void *targinfo, |
| 388 | unsigned int targinfosize, |
| 389 | unsigned int hook_mask) |
| 390 | { |
| 391 | struct ipt_clusterip_tgt_info *cipinfo = targinfo; |
| 392 | |
| 393 | struct clusterip_config *config; |
| 394 | |
| 395 | if (targinfosize != IPT_ALIGN(sizeof(struct ipt_clusterip_tgt_info))) { |
| 396 | printk(KERN_WARNING "CLUSTERIP: targinfosize %u != %Zu\n", |
| 397 | targinfosize, |
| 398 | IPT_ALIGN(sizeof(struct ipt_clusterip_tgt_info))); |
| 399 | return 0; |
| 400 | } |
| 401 | |
| 402 | if (cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP && |
| 403 | cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT && |
| 404 | cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT_DPT) { |
| 405 | printk(KERN_WARNING "CLUSTERIP: unknown mode `%u'\n", |
| 406 | cipinfo->hash_mode); |
| 407 | return 0; |
| 408 | |
| 409 | } |
| 410 | if (e->ip.dmsk.s_addr != 0xffffffff |
| 411 | || e->ip.dst.s_addr == 0) { |
| 412 | printk(KERN_ERR "CLUSTERIP: Please specify destination IP\n"); |
| 413 | return 0; |
| 414 | } |
| 415 | |
| 416 | /* FIXME: further sanity checks */ |
| 417 | |
| 418 | config = clusterip_config_find_get(e->ip.dst.s_addr); |
| 419 | if (!config) { |
| 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 | } |
| 446 | } |
| 447 | |
| 448 | cipinfo->config = config; |
| 449 | |
| 450 | return 1; |
| 451 | } |
| 452 | |
| 453 | /* drop reference count of cluster config when rule is deleted */ |
| 454 | static void destroy(void *matchinfo, unsigned int matchinfosize) |
| 455 | { |
| 456 | struct ipt_clusterip_tgt_info *cipinfo = matchinfo; |
| 457 | |
| 458 | /* we first remove the proc entry and then drop the reference |
| 459 | * count. In case anyone still accesses the file, the open/close |
| 460 | * functions are also incrementing the refcount on their own */ |
| 461 | #ifdef CONFIG_PROC_FS |
| 462 | remove_proc_entry(cipinfo->config->pde->name, |
| 463 | cipinfo->config->pde->parent); |
| 464 | #endif |
| 465 | clusterip_config_put(cipinfo->config); |
| 466 | } |
| 467 | |
| 468 | static struct ipt_target clusterip_tgt = { |
| 469 | .name = "CLUSTERIP", |
| 470 | .target = &target, |
| 471 | .checkentry = &checkentry, |
| 472 | .destroy = &destroy, |
| 473 | .me = THIS_MODULE |
| 474 | }; |
| 475 | |
| 476 | |
| 477 | /*********************************************************************** |
| 478 | * ARP MANGLING CODE |
| 479 | ***********************************************************************/ |
| 480 | |
| 481 | /* hardcoded for 48bit ethernet and 32bit ipv4 addresses */ |
| 482 | struct arp_payload { |
| 483 | u_int8_t src_hw[ETH_ALEN]; |
| 484 | u_int32_t src_ip; |
| 485 | u_int8_t dst_hw[ETH_ALEN]; |
| 486 | u_int32_t dst_ip; |
| 487 | } __attribute__ ((packed)); |
| 488 | |
| 489 | #ifdef CLUSTERIP_DEBUG |
| 490 | static void arp_print(struct arp_payload *payload) |
| 491 | { |
| 492 | #define HBUFFERLEN 30 |
| 493 | char hbuffer[HBUFFERLEN]; |
| 494 | int j,k; |
| 495 | const char hexbuf[]= "0123456789abcdef"; |
| 496 | |
| 497 | for (k=0, j=0; k < HBUFFERLEN-3 && j < ETH_ALEN; j++) { |
| 498 | hbuffer[k++]=hexbuf[(payload->src_hw[j]>>4)&15]; |
| 499 | hbuffer[k++]=hexbuf[payload->src_hw[j]&15]; |
| 500 | hbuffer[k++]=':'; |
| 501 | } |
| 502 | hbuffer[--k]='\0'; |
| 503 | |
| 504 | printk("src %u.%u.%u.%u@%s, dst %u.%u.%u.%u\n", |
| 505 | NIPQUAD(payload->src_ip), hbuffer, |
| 506 | NIPQUAD(payload->dst_ip)); |
| 507 | } |
| 508 | #endif |
| 509 | |
| 510 | static unsigned int |
| 511 | arp_mangle(unsigned int hook, |
| 512 | struct sk_buff **pskb, |
| 513 | const struct net_device *in, |
| 514 | const struct net_device *out, |
| 515 | int (*okfn)(struct sk_buff *)) |
| 516 | { |
| 517 | struct arphdr *arp = (*pskb)->nh.arph; |
| 518 | struct arp_payload *payload; |
| 519 | struct clusterip_config *c; |
| 520 | |
| 521 | /* we don't care about non-ethernet and non-ipv4 ARP */ |
| 522 | if (arp->ar_hrd != htons(ARPHRD_ETHER) |
| 523 | || arp->ar_pro != htons(ETH_P_IP) |
| 524 | || arp->ar_pln != 4 || arp->ar_hln != ETH_ALEN) |
| 525 | return NF_ACCEPT; |
| 526 | |
| 527 | /* we only want to mangle arp replies */ |
| 528 | if (arp->ar_op != htons(ARPOP_REPLY)) |
| 529 | return NF_ACCEPT; |
| 530 | |
| 531 | payload = (void *)(arp+1); |
| 532 | |
| 533 | /* if there is no clusterip configuration for the arp reply's |
| 534 | * source ip, we don't want to mangle it */ |
| 535 | c = clusterip_config_find_get(payload->src_ip); |
| 536 | if (!c) |
| 537 | return NF_ACCEPT; |
| 538 | |
| 539 | /* normally the linux kernel always replies to arp queries of |
| 540 | * addresses on different interfacs. However, in the CLUSTERIP case |
| 541 | * this wouldn't work, since we didn't subscribe the mcast group on |
| 542 | * other interfaces */ |
| 543 | if (c->dev != out) { |
| 544 | DEBUGP("CLUSTERIP: not mangling arp reply on different " |
| 545 | "interface: cip'%s'-skb'%s'\n", c->dev->name, out->name); |
| 546 | clusterip_config_put(c); |
| 547 | return NF_ACCEPT; |
| 548 | } |
| 549 | |
| 550 | /* mangle reply hardware address */ |
| 551 | memcpy(payload->src_hw, c->clustermac, arp->ar_hln); |
| 552 | |
| 553 | #ifdef CLUSTERIP_DEBUG |
| 554 | DEBUGP(KERN_DEBUG "CLUSTERIP mangled arp reply: "); |
| 555 | arp_print(payload); |
| 556 | #endif |
| 557 | |
| 558 | clusterip_config_put(c); |
| 559 | |
| 560 | return NF_ACCEPT; |
| 561 | } |
| 562 | |
| 563 | static struct nf_hook_ops cip_arp_ops = { |
| 564 | .hook = arp_mangle, |
| 565 | .pf = NF_ARP, |
| 566 | .hooknum = NF_ARP_OUT, |
| 567 | .priority = -1 |
| 568 | }; |
| 569 | |
| 570 | /*********************************************************************** |
| 571 | * PROC DIR HANDLING |
| 572 | ***********************************************************************/ |
| 573 | |
| 574 | #ifdef CONFIG_PROC_FS |
| 575 | |
| 576 | static void *clusterip_seq_start(struct seq_file *s, loff_t *pos) |
| 577 | { |
| 578 | struct proc_dir_entry *pde = s->private; |
| 579 | struct clusterip_config *c = pde->data; |
| 580 | unsigned int *nodeidx; |
| 581 | |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 582 | read_lock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | if (*pos >= c->num_local_nodes) |
| 584 | return NULL; |
| 585 | |
| 586 | nodeidx = kmalloc(sizeof(unsigned int), GFP_KERNEL); |
| 587 | if (!nodeidx) |
| 588 | return ERR_PTR(-ENOMEM); |
| 589 | |
| 590 | *nodeidx = *pos; |
| 591 | return nodeidx; |
| 592 | } |
| 593 | |
| 594 | static void *clusterip_seq_next(struct seq_file *s, void *v, loff_t *pos) |
| 595 | { |
| 596 | struct proc_dir_entry *pde = s->private; |
| 597 | struct clusterip_config *c = pde->data; |
| 598 | unsigned int *nodeidx = (unsigned int *)v; |
| 599 | |
| 600 | *pos = ++(*nodeidx); |
| 601 | if (*pos >= c->num_local_nodes) { |
| 602 | kfree(v); |
| 603 | return NULL; |
| 604 | } |
| 605 | return nodeidx; |
| 606 | } |
| 607 | |
| 608 | static void clusterip_seq_stop(struct seq_file *s, void *v) |
| 609 | { |
| 610 | kfree(v); |
| 611 | |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame^] | 612 | read_unlock_bh(&clusterip_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | } |
| 614 | |
| 615 | static int clusterip_seq_show(struct seq_file *s, void *v) |
| 616 | { |
| 617 | struct proc_dir_entry *pde = s->private; |
| 618 | struct clusterip_config *c = pde->data; |
| 619 | unsigned int *nodeidx = (unsigned int *)v; |
| 620 | |
| 621 | if (*nodeidx != 0) |
| 622 | seq_putc(s, ','); |
| 623 | seq_printf(s, "%u", c->local_nodes[*nodeidx]); |
| 624 | |
| 625 | if (*nodeidx == c->num_local_nodes-1) |
| 626 | seq_putc(s, '\n'); |
| 627 | |
| 628 | return 0; |
| 629 | } |
| 630 | |
| 631 | static struct seq_operations clusterip_seq_ops = { |
| 632 | .start = clusterip_seq_start, |
| 633 | .next = clusterip_seq_next, |
| 634 | .stop = clusterip_seq_stop, |
| 635 | .show = clusterip_seq_show, |
| 636 | }; |
| 637 | |
| 638 | static int clusterip_proc_open(struct inode *inode, struct file *file) |
| 639 | { |
| 640 | int ret = seq_open(file, &clusterip_seq_ops); |
| 641 | |
| 642 | if (!ret) { |
| 643 | struct seq_file *sf = file->private_data; |
| 644 | struct proc_dir_entry *pde = PDE(inode); |
| 645 | struct clusterip_config *c = pde->data; |
| 646 | |
| 647 | sf->private = pde; |
| 648 | |
| 649 | clusterip_config_get(c); |
| 650 | } |
| 651 | |
| 652 | return ret; |
| 653 | } |
| 654 | |
| 655 | static int clusterip_proc_release(struct inode *inode, struct file *file) |
| 656 | { |
| 657 | struct proc_dir_entry *pde = PDE(inode); |
| 658 | struct clusterip_config *c = pde->data; |
| 659 | int ret; |
| 660 | |
| 661 | ret = seq_release(inode, file); |
| 662 | |
| 663 | if (!ret) |
| 664 | clusterip_config_put(c); |
| 665 | |
| 666 | return ret; |
| 667 | } |
| 668 | |
| 669 | static ssize_t clusterip_proc_write(struct file *file, const char __user *input, |
| 670 | size_t size, loff_t *ofs) |
| 671 | { |
| 672 | #define PROC_WRITELEN 10 |
| 673 | char buffer[PROC_WRITELEN+1]; |
| 674 | struct proc_dir_entry *pde = PDE(file->f_dentry->d_inode); |
| 675 | struct clusterip_config *c = pde->data; |
| 676 | unsigned long nodenum; |
| 677 | |
| 678 | if (copy_from_user(buffer, input, PROC_WRITELEN)) |
| 679 | return -EFAULT; |
| 680 | |
| 681 | if (*buffer == '+') { |
| 682 | nodenum = simple_strtoul(buffer+1, NULL, 10); |
| 683 | if (clusterip_add_node(c, nodenum)) |
| 684 | return -ENOMEM; |
| 685 | } else if (*buffer == '-') { |
| 686 | nodenum = simple_strtoul(buffer+1, NULL,10); |
| 687 | if (clusterip_del_node(c, nodenum)) |
| 688 | return -ENOENT; |
| 689 | } else |
| 690 | return -EIO; |
| 691 | |
| 692 | return size; |
| 693 | } |
| 694 | |
| 695 | static struct file_operations clusterip_proc_fops = { |
| 696 | .owner = THIS_MODULE, |
| 697 | .open = clusterip_proc_open, |
| 698 | .read = seq_read, |
| 699 | .write = clusterip_proc_write, |
| 700 | .llseek = seq_lseek, |
| 701 | .release = clusterip_proc_release, |
| 702 | }; |
| 703 | |
| 704 | #endif /* CONFIG_PROC_FS */ |
| 705 | |
| 706 | static int init_or_cleanup(int fini) |
| 707 | { |
| 708 | int ret; |
| 709 | |
| 710 | if (fini) |
| 711 | goto cleanup; |
| 712 | |
| 713 | if (ipt_register_target(&clusterip_tgt)) { |
| 714 | ret = -EINVAL; |
| 715 | goto cleanup_none; |
| 716 | } |
| 717 | |
| 718 | if (nf_register_hook(&cip_arp_ops) < 0) { |
| 719 | ret = -EINVAL; |
| 720 | goto cleanup_target; |
| 721 | } |
| 722 | |
| 723 | #ifdef CONFIG_PROC_FS |
| 724 | clusterip_procdir = proc_mkdir("ipt_CLUSTERIP", proc_net); |
| 725 | if (!clusterip_procdir) { |
| 726 | printk(KERN_ERR "CLUSTERIP: Unable to proc dir entry\n"); |
| 727 | ret = -ENOMEM; |
| 728 | goto cleanup_hook; |
| 729 | } |
| 730 | #endif /* CONFIG_PROC_FS */ |
| 731 | |
| 732 | printk(KERN_NOTICE "ClusterIP Version %s loaded successfully\n", |
| 733 | CLUSTERIP_VERSION); |
| 734 | |
| 735 | return 0; |
| 736 | |
| 737 | cleanup: |
| 738 | printk(KERN_NOTICE "ClusterIP Version %s unloading\n", |
| 739 | CLUSTERIP_VERSION); |
| 740 | #ifdef CONFIG_PROC_FS |
| 741 | remove_proc_entry(clusterip_procdir->name, clusterip_procdir->parent); |
| 742 | #endif |
| 743 | cleanup_hook: |
| 744 | nf_unregister_hook(&cip_arp_ops); |
| 745 | cleanup_target: |
| 746 | ipt_unregister_target(&clusterip_tgt); |
| 747 | cleanup_none: |
| 748 | return -EINVAL; |
| 749 | } |
| 750 | |
| 751 | static int __init init(void) |
| 752 | { |
| 753 | return init_or_cleanup(0); |
| 754 | } |
| 755 | |
| 756 | static void __exit fini(void) |
| 757 | { |
| 758 | init_or_cleanup(1); |
| 759 | } |
| 760 | |
| 761 | module_init(init); |
| 762 | module_exit(fini); |