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