Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 1 | /* |
| 2 | * net/core/fib_rules.c Generic Routing Rules |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License as |
| 6 | * published by the Free Software Foundation, version 2. |
| 7 | * |
| 8 | * Authors: Thomas Graf <tgraf@suug.ch> |
| 9 | */ |
| 10 | |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 11 | #include <linux/types.h> |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/list.h> |
| 14 | #include <net/fib_rules.h> |
| 15 | |
| 16 | static LIST_HEAD(rules_ops); |
| 17 | static DEFINE_SPINLOCK(rules_mod_lock); |
| 18 | |
| 19 | static void notify_rule_change(int event, struct fib_rule *rule, |
Thomas Graf | c17084d | 2006-08-15 00:32:48 -0700 | [diff] [blame] | 20 | struct fib_rules_ops *ops, struct nlmsghdr *nlh, |
| 21 | u32 pid); |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 22 | |
| 23 | static struct fib_rules_ops *lookup_rules_ops(int family) |
| 24 | { |
| 25 | struct fib_rules_ops *ops; |
| 26 | |
| 27 | rcu_read_lock(); |
| 28 | list_for_each_entry_rcu(ops, &rules_ops, list) { |
| 29 | if (ops->family == family) { |
| 30 | if (!try_module_get(ops->owner)) |
| 31 | ops = NULL; |
| 32 | rcu_read_unlock(); |
| 33 | return ops; |
| 34 | } |
| 35 | } |
| 36 | rcu_read_unlock(); |
| 37 | |
| 38 | return NULL; |
| 39 | } |
| 40 | |
| 41 | static void rules_ops_put(struct fib_rules_ops *ops) |
| 42 | { |
| 43 | if (ops) |
| 44 | module_put(ops->owner); |
| 45 | } |
| 46 | |
| 47 | int fib_rules_register(struct fib_rules_ops *ops) |
| 48 | { |
| 49 | int err = -EEXIST; |
| 50 | struct fib_rules_ops *o; |
| 51 | |
| 52 | if (ops->rule_size < sizeof(struct fib_rule)) |
| 53 | return -EINVAL; |
| 54 | |
| 55 | if (ops->match == NULL || ops->configure == NULL || |
| 56 | ops->compare == NULL || ops->fill == NULL || |
| 57 | ops->action == NULL) |
| 58 | return -EINVAL; |
| 59 | |
| 60 | spin_lock(&rules_mod_lock); |
| 61 | list_for_each_entry(o, &rules_ops, list) |
| 62 | if (ops->family == o->family) |
| 63 | goto errout; |
| 64 | |
| 65 | list_add_tail_rcu(&ops->list, &rules_ops); |
| 66 | err = 0; |
| 67 | errout: |
| 68 | spin_unlock(&rules_mod_lock); |
| 69 | |
| 70 | return err; |
| 71 | } |
| 72 | |
| 73 | EXPORT_SYMBOL_GPL(fib_rules_register); |
| 74 | |
| 75 | static void cleanup_ops(struct fib_rules_ops *ops) |
| 76 | { |
| 77 | struct fib_rule *rule, *tmp; |
| 78 | |
| 79 | list_for_each_entry_safe(rule, tmp, ops->rules_list, list) { |
| 80 | list_del_rcu(&rule->list); |
| 81 | fib_rule_put(rule); |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | int fib_rules_unregister(struct fib_rules_ops *ops) |
| 86 | { |
| 87 | int err = 0; |
| 88 | struct fib_rules_ops *o; |
| 89 | |
| 90 | spin_lock(&rules_mod_lock); |
| 91 | list_for_each_entry(o, &rules_ops, list) { |
| 92 | if (o == ops) { |
| 93 | list_del_rcu(&o->list); |
| 94 | cleanup_ops(ops); |
| 95 | goto out; |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | err = -ENOENT; |
| 100 | out: |
| 101 | spin_unlock(&rules_mod_lock); |
| 102 | |
| 103 | synchronize_rcu(); |
| 104 | |
| 105 | return err; |
| 106 | } |
| 107 | |
| 108 | EXPORT_SYMBOL_GPL(fib_rules_unregister); |
| 109 | |
| 110 | int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl, |
| 111 | int flags, struct fib_lookup_arg *arg) |
| 112 | { |
| 113 | struct fib_rule *rule; |
| 114 | int err; |
| 115 | |
| 116 | rcu_read_lock(); |
| 117 | |
| 118 | list_for_each_entry_rcu(rule, ops->rules_list, list) { |
| 119 | if (rule->ifindex && (rule->ifindex != fl->iif)) |
| 120 | continue; |
| 121 | |
Thomas Graf | b8964ed | 2006-11-09 15:22:18 -0800 | [diff] [blame^] | 122 | if ((rule->mark ^ fl->mark) & rule->mark_mask) |
| 123 | continue; |
| 124 | |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 125 | if (!ops->match(rule, fl, flags)) |
| 126 | continue; |
| 127 | |
| 128 | err = ops->action(rule, fl, flags, arg); |
| 129 | if (err != -EAGAIN) { |
| 130 | fib_rule_get(rule); |
| 131 | arg->rule = rule; |
| 132 | goto out; |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | err = -ENETUNREACH; |
| 137 | out: |
| 138 | rcu_read_unlock(); |
| 139 | |
| 140 | return err; |
| 141 | } |
| 142 | |
| 143 | EXPORT_SYMBOL_GPL(fib_rules_lookup); |
| 144 | |
| 145 | int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) |
| 146 | { |
| 147 | struct fib_rule_hdr *frh = nlmsg_data(nlh); |
| 148 | struct fib_rules_ops *ops = NULL; |
| 149 | struct fib_rule *rule, *r, *last = NULL; |
| 150 | struct nlattr *tb[FRA_MAX+1]; |
| 151 | int err = -EINVAL; |
| 152 | |
| 153 | if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) |
| 154 | goto errout; |
| 155 | |
| 156 | ops = lookup_rules_ops(frh->family); |
| 157 | if (ops == NULL) { |
| 158 | err = EAFNOSUPPORT; |
| 159 | goto errout; |
| 160 | } |
| 161 | |
| 162 | err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy); |
| 163 | if (err < 0) |
| 164 | goto errout; |
| 165 | |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 166 | rule = kzalloc(ops->rule_size, GFP_KERNEL); |
| 167 | if (rule == NULL) { |
| 168 | err = -ENOMEM; |
| 169 | goto errout; |
| 170 | } |
| 171 | |
| 172 | if (tb[FRA_PRIORITY]) |
| 173 | rule->pref = nla_get_u32(tb[FRA_PRIORITY]); |
| 174 | |
| 175 | if (tb[FRA_IFNAME]) { |
| 176 | struct net_device *dev; |
| 177 | |
| 178 | rule->ifindex = -1; |
Thomas Graf | 5176f91 | 2006-08-26 20:13:18 -0700 | [diff] [blame] | 179 | nla_strlcpy(rule->ifname, tb[FRA_IFNAME], IFNAMSIZ); |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 180 | dev = __dev_get_by_name(rule->ifname); |
| 181 | if (dev) |
| 182 | rule->ifindex = dev->ifindex; |
| 183 | } |
| 184 | |
Thomas Graf | b8964ed | 2006-11-09 15:22:18 -0800 | [diff] [blame^] | 185 | if (tb[FRA_FWMARK]) { |
| 186 | rule->mark = nla_get_u32(tb[FRA_FWMARK]); |
| 187 | if (rule->mark) |
| 188 | /* compatibility: if the mark value is non-zero all bits |
| 189 | * are compared unless a mask is explicitly specified. |
| 190 | */ |
| 191 | rule->mark_mask = 0xFFFFFFFF; |
| 192 | } |
| 193 | |
| 194 | if (tb[FRA_FWMASK]) |
| 195 | rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]); |
| 196 | |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 197 | rule->action = frh->action; |
| 198 | rule->flags = frh->flags; |
Patrick McHardy | 9e762a4 | 2006-08-10 23:09:48 -0700 | [diff] [blame] | 199 | rule->table = frh_get_table(frh, tb); |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 200 | |
| 201 | if (!rule->pref && ops->default_pref) |
| 202 | rule->pref = ops->default_pref(); |
| 203 | |
| 204 | err = ops->configure(rule, skb, nlh, frh, tb); |
| 205 | if (err < 0) |
| 206 | goto errout_free; |
| 207 | |
| 208 | list_for_each_entry(r, ops->rules_list, list) { |
| 209 | if (r->pref > rule->pref) |
| 210 | break; |
| 211 | last = r; |
| 212 | } |
| 213 | |
| 214 | fib_rule_get(rule); |
| 215 | |
| 216 | if (last) |
| 217 | list_add_rcu(&rule->list, &last->list); |
| 218 | else |
| 219 | list_add_rcu(&rule->list, ops->rules_list); |
| 220 | |
Thomas Graf | c17084d | 2006-08-15 00:32:48 -0700 | [diff] [blame] | 221 | notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).pid); |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 222 | rules_ops_put(ops); |
| 223 | return 0; |
| 224 | |
| 225 | errout_free: |
| 226 | kfree(rule); |
| 227 | errout: |
| 228 | rules_ops_put(ops); |
| 229 | return err; |
| 230 | } |
| 231 | |
| 232 | int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) |
| 233 | { |
| 234 | struct fib_rule_hdr *frh = nlmsg_data(nlh); |
| 235 | struct fib_rules_ops *ops = NULL; |
| 236 | struct fib_rule *rule; |
| 237 | struct nlattr *tb[FRA_MAX+1]; |
| 238 | int err = -EINVAL; |
| 239 | |
| 240 | if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) |
| 241 | goto errout; |
| 242 | |
| 243 | ops = lookup_rules_ops(frh->family); |
| 244 | if (ops == NULL) { |
| 245 | err = EAFNOSUPPORT; |
| 246 | goto errout; |
| 247 | } |
| 248 | |
| 249 | err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy); |
| 250 | if (err < 0) |
| 251 | goto errout; |
| 252 | |
| 253 | list_for_each_entry(rule, ops->rules_list, list) { |
| 254 | if (frh->action && (frh->action != rule->action)) |
| 255 | continue; |
| 256 | |
Patrick McHardy | 9e762a4 | 2006-08-10 23:09:48 -0700 | [diff] [blame] | 257 | if (frh->table && (frh_get_table(frh, tb) != rule->table)) |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 258 | continue; |
| 259 | |
| 260 | if (tb[FRA_PRIORITY] && |
| 261 | (rule->pref != nla_get_u32(tb[FRA_PRIORITY]))) |
| 262 | continue; |
| 263 | |
| 264 | if (tb[FRA_IFNAME] && |
| 265 | nla_strcmp(tb[FRA_IFNAME], rule->ifname)) |
| 266 | continue; |
| 267 | |
Thomas Graf | b8964ed | 2006-11-09 15:22:18 -0800 | [diff] [blame^] | 268 | if (tb[FRA_FWMARK] && |
| 269 | (rule->mark != nla_get_u32(tb[FRA_FWMARK]))) |
| 270 | continue; |
| 271 | |
| 272 | if (tb[FRA_FWMASK] && |
| 273 | (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK]))) |
| 274 | continue; |
| 275 | |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 276 | if (!ops->compare(rule, frh, tb)) |
| 277 | continue; |
| 278 | |
| 279 | if (rule->flags & FIB_RULE_PERMANENT) { |
| 280 | err = -EPERM; |
| 281 | goto errout; |
| 282 | } |
| 283 | |
| 284 | list_del_rcu(&rule->list); |
| 285 | synchronize_rcu(); |
Thomas Graf | c17084d | 2006-08-15 00:32:48 -0700 | [diff] [blame] | 286 | notify_rule_change(RTM_DELRULE, rule, ops, nlh, |
| 287 | NETLINK_CB(skb).pid); |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 288 | fib_rule_put(rule); |
| 289 | rules_ops_put(ops); |
| 290 | return 0; |
| 291 | } |
| 292 | |
| 293 | err = -ENOENT; |
| 294 | errout: |
| 295 | rules_ops_put(ops); |
| 296 | return err; |
| 297 | } |
| 298 | |
| 299 | static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule, |
| 300 | u32 pid, u32 seq, int type, int flags, |
| 301 | struct fib_rules_ops *ops) |
| 302 | { |
| 303 | struct nlmsghdr *nlh; |
| 304 | struct fib_rule_hdr *frh; |
| 305 | |
| 306 | nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags); |
| 307 | if (nlh == NULL) |
| 308 | return -1; |
| 309 | |
| 310 | frh = nlmsg_data(nlh); |
| 311 | frh->table = rule->table; |
Patrick McHardy | 9e762a4 | 2006-08-10 23:09:48 -0700 | [diff] [blame] | 312 | NLA_PUT_U32(skb, FRA_TABLE, rule->table); |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 313 | frh->res1 = 0; |
| 314 | frh->res2 = 0; |
| 315 | frh->action = rule->action; |
| 316 | frh->flags = rule->flags; |
| 317 | |
| 318 | if (rule->ifname[0]) |
| 319 | NLA_PUT_STRING(skb, FRA_IFNAME, rule->ifname); |
| 320 | |
| 321 | if (rule->pref) |
| 322 | NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref); |
| 323 | |
Thomas Graf | b8964ed | 2006-11-09 15:22:18 -0800 | [diff] [blame^] | 324 | if (rule->mark) |
| 325 | NLA_PUT_U32(skb, FRA_FWMARK, rule->mark); |
| 326 | |
| 327 | if (rule->mark_mask || rule->mark) |
| 328 | NLA_PUT_U32(skb, FRA_FWMASK, rule->mark_mask); |
| 329 | |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 330 | if (ops->fill(rule, skb, nlh, frh) < 0) |
| 331 | goto nla_put_failure; |
| 332 | |
| 333 | return nlmsg_end(skb, nlh); |
| 334 | |
| 335 | nla_put_failure: |
| 336 | return nlmsg_cancel(skb, nlh); |
| 337 | } |
| 338 | |
| 339 | int fib_rules_dump(struct sk_buff *skb, struct netlink_callback *cb, int family) |
| 340 | { |
| 341 | int idx = 0; |
| 342 | struct fib_rule *rule; |
| 343 | struct fib_rules_ops *ops; |
| 344 | |
| 345 | ops = lookup_rules_ops(family); |
| 346 | if (ops == NULL) |
| 347 | return -EAFNOSUPPORT; |
| 348 | |
| 349 | rcu_read_lock(); |
| 350 | list_for_each_entry(rule, ops->rules_list, list) { |
| 351 | if (idx < cb->args[0]) |
| 352 | goto skip; |
| 353 | |
| 354 | if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid, |
| 355 | cb->nlh->nlmsg_seq, RTM_NEWRULE, |
| 356 | NLM_F_MULTI, ops) < 0) |
| 357 | break; |
| 358 | skip: |
| 359 | idx++; |
| 360 | } |
| 361 | rcu_read_unlock(); |
| 362 | cb->args[0] = idx; |
| 363 | rules_ops_put(ops); |
| 364 | |
| 365 | return skb->len; |
| 366 | } |
| 367 | |
| 368 | EXPORT_SYMBOL_GPL(fib_rules_dump); |
| 369 | |
| 370 | static void notify_rule_change(int event, struct fib_rule *rule, |
Thomas Graf | c17084d | 2006-08-15 00:32:48 -0700 | [diff] [blame] | 371 | struct fib_rules_ops *ops, struct nlmsghdr *nlh, |
| 372 | u32 pid) |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 373 | { |
Thomas Graf | c17084d | 2006-08-15 00:32:48 -0700 | [diff] [blame] | 374 | struct sk_buff *skb; |
| 375 | int err = -ENOBUFS; |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 376 | |
Thomas Graf | c17084d | 2006-08-15 00:32:48 -0700 | [diff] [blame] | 377 | skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 378 | if (skb == NULL) |
Thomas Graf | c17084d | 2006-08-15 00:32:48 -0700 | [diff] [blame] | 379 | goto errout; |
| 380 | |
| 381 | err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops); |
| 382 | if (err < 0) { |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 383 | kfree_skb(skb); |
Thomas Graf | c17084d | 2006-08-15 00:32:48 -0700 | [diff] [blame] | 384 | goto errout; |
| 385 | } |
| 386 | |
| 387 | err = rtnl_notify(skb, pid, ops->nlgroup, nlh, GFP_KERNEL); |
| 388 | errout: |
| 389 | if (err < 0) |
| 390 | rtnl_set_sk_err(ops->nlgroup, err); |
Thomas Graf | 14c0b97 | 2006-08-04 03:38:38 -0700 | [diff] [blame] | 391 | } |
| 392 | |
| 393 | static void attach_rules(struct list_head *rules, struct net_device *dev) |
| 394 | { |
| 395 | struct fib_rule *rule; |
| 396 | |
| 397 | list_for_each_entry(rule, rules, list) { |
| 398 | if (rule->ifindex == -1 && |
| 399 | strcmp(dev->name, rule->ifname) == 0) |
| 400 | rule->ifindex = dev->ifindex; |
| 401 | } |
| 402 | } |
| 403 | |
| 404 | static void detach_rules(struct list_head *rules, struct net_device *dev) |
| 405 | { |
| 406 | struct fib_rule *rule; |
| 407 | |
| 408 | list_for_each_entry(rule, rules, list) |
| 409 | if (rule->ifindex == dev->ifindex) |
| 410 | rule->ifindex = -1; |
| 411 | } |
| 412 | |
| 413 | |
| 414 | static int fib_rules_event(struct notifier_block *this, unsigned long event, |
| 415 | void *ptr) |
| 416 | { |
| 417 | struct net_device *dev = ptr; |
| 418 | struct fib_rules_ops *ops; |
| 419 | |
| 420 | ASSERT_RTNL(); |
| 421 | rcu_read_lock(); |
| 422 | |
| 423 | switch (event) { |
| 424 | case NETDEV_REGISTER: |
| 425 | list_for_each_entry(ops, &rules_ops, list) |
| 426 | attach_rules(ops->rules_list, dev); |
| 427 | break; |
| 428 | |
| 429 | case NETDEV_UNREGISTER: |
| 430 | list_for_each_entry(ops, &rules_ops, list) |
| 431 | detach_rules(ops->rules_list, dev); |
| 432 | break; |
| 433 | } |
| 434 | |
| 435 | rcu_read_unlock(); |
| 436 | |
| 437 | return NOTIFY_DONE; |
| 438 | } |
| 439 | |
| 440 | static struct notifier_block fib_rules_notifier = { |
| 441 | .notifier_call = fib_rules_event, |
| 442 | }; |
| 443 | |
| 444 | static int __init fib_rules_init(void) |
| 445 | { |
| 446 | return register_netdevice_notifier(&fib_rules_notifier); |
| 447 | } |
| 448 | |
| 449 | subsys_initcall(fib_rules_init); |