linux/net/core/fib_rules.c
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   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/types.h>
  12#include <linux/kernel.h>
  13#include <linux/slab.h>
  14#include <linux/list.h>
  15#include <linux/module.h>
  16#include <net/net_namespace.h>
  17#include <net/sock.h>
  18#include <net/fib_rules.h>
  19#include <net/ip_tunnels.h>
  20
  21static const struct fib_kuid_range fib_kuid_range_unset = {
  22        KUIDT_INIT(0),
  23        KUIDT_INIT(~0),
  24};
  25
  26bool fib_rule_matchall(const struct fib_rule *rule)
  27{
  28        if (rule->iifindex || rule->oifindex || rule->mark || rule->tun_id ||
  29            rule->flags)
  30                return false;
  31        if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1)
  32                return false;
  33        if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) ||
  34            !uid_eq(rule->uid_range.end, fib_kuid_range_unset.end))
  35                return false;
  36        if (fib_rule_port_range_set(&rule->sport_range))
  37                return false;
  38        if (fib_rule_port_range_set(&rule->dport_range))
  39                return false;
  40        return true;
  41}
  42EXPORT_SYMBOL_GPL(fib_rule_matchall);
  43
  44int fib_default_rule_add(struct fib_rules_ops *ops,
  45                         u32 pref, u32 table, u32 flags)
  46{
  47        struct fib_rule *r;
  48
  49        r = kzalloc(ops->rule_size, GFP_KERNEL);
  50        if (r == NULL)
  51                return -ENOMEM;
  52
  53        refcount_set(&r->refcnt, 1);
  54        r->action = FR_ACT_TO_TBL;
  55        r->pref = pref;
  56        r->table = table;
  57        r->flags = flags;
  58        r->proto = RTPROT_KERNEL;
  59        r->fr_net = ops->fro_net;
  60        r->uid_range = fib_kuid_range_unset;
  61
  62        r->suppress_prefixlen = -1;
  63        r->suppress_ifgroup = -1;
  64
  65        /* The lock is not required here, the list in unreacheable
  66         * at the moment this function is called */
  67        list_add_tail(&r->list, &ops->rules_list);
  68        return 0;
  69}
  70EXPORT_SYMBOL(fib_default_rule_add);
  71
  72static u32 fib_default_rule_pref(struct fib_rules_ops *ops)
  73{
  74        struct list_head *pos;
  75        struct fib_rule *rule;
  76
  77        if (!list_empty(&ops->rules_list)) {
  78                pos = ops->rules_list.next;
  79                if (pos->next != &ops->rules_list) {
  80                        rule = list_entry(pos->next, struct fib_rule, list);
  81                        if (rule->pref)
  82                                return rule->pref - 1;
  83                }
  84        }
  85
  86        return 0;
  87}
  88
  89static void notify_rule_change(int event, struct fib_rule *rule,
  90                               struct fib_rules_ops *ops, struct nlmsghdr *nlh,
  91                               u32 pid);
  92
  93static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family)
  94{
  95        struct fib_rules_ops *ops;
  96
  97        rcu_read_lock();
  98        list_for_each_entry_rcu(ops, &net->rules_ops, list) {
  99                if (ops->family == family) {
 100                        if (!try_module_get(ops->owner))
 101                                ops = NULL;
 102                        rcu_read_unlock();
 103                        return ops;
 104                }
 105        }
 106        rcu_read_unlock();
 107
 108        return NULL;
 109}
 110
 111static void rules_ops_put(struct fib_rules_ops *ops)
 112{
 113        if (ops)
 114                module_put(ops->owner);
 115}
 116
 117static void flush_route_cache(struct fib_rules_ops *ops)
 118{
 119        if (ops->flush_cache)
 120                ops->flush_cache(ops);
 121}
 122
 123static int __fib_rules_register(struct fib_rules_ops *ops)
 124{
 125        int err = -EEXIST;
 126        struct fib_rules_ops *o;
 127        struct net *net;
 128
 129        net = ops->fro_net;
 130
 131        if (ops->rule_size < sizeof(struct fib_rule))
 132                return -EINVAL;
 133
 134        if (ops->match == NULL || ops->configure == NULL ||
 135            ops->compare == NULL || ops->fill == NULL ||
 136            ops->action == NULL)
 137                return -EINVAL;
 138
 139        spin_lock(&net->rules_mod_lock);
 140        list_for_each_entry(o, &net->rules_ops, list)
 141                if (ops->family == o->family)
 142                        goto errout;
 143
 144        list_add_tail_rcu(&ops->list, &net->rules_ops);
 145        err = 0;
 146errout:
 147        spin_unlock(&net->rules_mod_lock);
 148
 149        return err;
 150}
 151
 152struct fib_rules_ops *
 153fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
 154{
 155        struct fib_rules_ops *ops;
 156        int err;
 157
 158        ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
 159        if (ops == NULL)
 160                return ERR_PTR(-ENOMEM);
 161
 162        INIT_LIST_HEAD(&ops->rules_list);
 163        ops->fro_net = net;
 164
 165        err = __fib_rules_register(ops);
 166        if (err) {
 167                kfree(ops);
 168                ops = ERR_PTR(err);
 169        }
 170
 171        return ops;
 172}
 173EXPORT_SYMBOL_GPL(fib_rules_register);
 174
 175static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
 176{
 177        struct fib_rule *rule, *tmp;
 178
 179        list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
 180                list_del_rcu(&rule->list);
 181                if (ops->delete)
 182                        ops->delete(rule);
 183                fib_rule_put(rule);
 184        }
 185}
 186
 187void fib_rules_unregister(struct fib_rules_ops *ops)
 188{
 189        struct net *net = ops->fro_net;
 190
 191        spin_lock(&net->rules_mod_lock);
 192        list_del_rcu(&ops->list);
 193        spin_unlock(&net->rules_mod_lock);
 194
 195        fib_rules_cleanup_ops(ops);
 196        kfree_rcu(ops, rcu);
 197}
 198EXPORT_SYMBOL_GPL(fib_rules_unregister);
 199
 200static int uid_range_set(struct fib_kuid_range *range)
 201{
 202        return uid_valid(range->start) && uid_valid(range->end);
 203}
 204
 205static struct fib_kuid_range nla_get_kuid_range(struct nlattr **tb)
 206{
 207        struct fib_rule_uid_range *in;
 208        struct fib_kuid_range out;
 209
 210        in = (struct fib_rule_uid_range *)nla_data(tb[FRA_UID_RANGE]);
 211
 212        out.start = make_kuid(current_user_ns(), in->start);
 213        out.end = make_kuid(current_user_ns(), in->end);
 214
 215        return out;
 216}
 217
 218static int nla_put_uid_range(struct sk_buff *skb, struct fib_kuid_range *range)
 219{
 220        struct fib_rule_uid_range out = {
 221                from_kuid_munged(current_user_ns(), range->start),
 222                from_kuid_munged(current_user_ns(), range->end)
 223        };
 224
 225        return nla_put(skb, FRA_UID_RANGE, sizeof(out), &out);
 226}
 227
 228static int nla_get_port_range(struct nlattr *pattr,
 229                              struct fib_rule_port_range *port_range)
 230{
 231        const struct fib_rule_port_range *pr = nla_data(pattr);
 232
 233        if (!fib_rule_port_range_valid(pr))
 234                return -EINVAL;
 235
 236        port_range->start = pr->start;
 237        port_range->end = pr->end;
 238
 239        return 0;
 240}
 241
 242static int nla_put_port_range(struct sk_buff *skb, int attrtype,
 243                              struct fib_rule_port_range *range)
 244{
 245        return nla_put(skb, attrtype, sizeof(*range), range);
 246}
 247
 248static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
 249                          struct flowi *fl, int flags,
 250                          struct fib_lookup_arg *arg)
 251{
 252        int ret = 0;
 253
 254        if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
 255                goto out;
 256
 257        if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
 258                goto out;
 259
 260        if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
 261                goto out;
 262
 263        if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id))
 264                goto out;
 265
 266        if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg))
 267                goto out;
 268
 269        if (uid_lt(fl->flowi_uid, rule->uid_range.start) ||
 270            uid_gt(fl->flowi_uid, rule->uid_range.end))
 271                goto out;
 272
 273        ret = ops->match(rule, fl, flags);
 274out:
 275        return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
 276}
 277
 278int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
 279                     int flags, struct fib_lookup_arg *arg)
 280{
 281        struct fib_rule *rule;
 282        int err;
 283
 284        rcu_read_lock();
 285
 286        list_for_each_entry_rcu(rule, &ops->rules_list, list) {
 287jumped:
 288                if (!fib_rule_match(rule, ops, fl, flags, arg))
 289                        continue;
 290
 291                if (rule->action == FR_ACT_GOTO) {
 292                        struct fib_rule *target;
 293
 294                        target = rcu_dereference(rule->ctarget);
 295                        if (target == NULL) {
 296                                continue;
 297                        } else {
 298                                rule = target;
 299                                goto jumped;
 300                        }
 301                } else if (rule->action == FR_ACT_NOP)
 302                        continue;
 303                else
 304                        err = ops->action(rule, fl, flags, arg);
 305
 306                if (!err && ops->suppress && ops->suppress(rule, arg))
 307                        continue;
 308
 309                if (err != -EAGAIN) {
 310                        if ((arg->flags & FIB_LOOKUP_NOREF) ||
 311                            likely(refcount_inc_not_zero(&rule->refcnt))) {
 312                                arg->rule = rule;
 313                                goto out;
 314                        }
 315                        break;
 316                }
 317        }
 318
 319        err = -ESRCH;
 320out:
 321        rcu_read_unlock();
 322
 323        return err;
 324}
 325EXPORT_SYMBOL_GPL(fib_rules_lookup);
 326
 327static int call_fib_rule_notifier(struct notifier_block *nb, struct net *net,
 328                                  enum fib_event_type event_type,
 329                                  struct fib_rule *rule, int family)
 330{
 331        struct fib_rule_notifier_info info = {
 332                .info.family = family,
 333                .rule = rule,
 334        };
 335
 336        return call_fib_notifier(nb, net, event_type, &info.info);
 337}
 338
 339static int call_fib_rule_notifiers(struct net *net,
 340                                   enum fib_event_type event_type,
 341                                   struct fib_rule *rule,
 342                                   struct fib_rules_ops *ops,
 343                                   struct netlink_ext_ack *extack)
 344{
 345        struct fib_rule_notifier_info info = {
 346                .info.family = ops->family,
 347                .info.extack = extack,
 348                .rule = rule,
 349        };
 350
 351        ops->fib_rules_seq++;
 352        return call_fib_notifiers(net, event_type, &info.info);
 353}
 354
 355/* Called with rcu_read_lock() */
 356int fib_rules_dump(struct net *net, struct notifier_block *nb, int family)
 357{
 358        struct fib_rules_ops *ops;
 359        struct fib_rule *rule;
 360
 361        ops = lookup_rules_ops(net, family);
 362        if (!ops)
 363                return -EAFNOSUPPORT;
 364        list_for_each_entry_rcu(rule, &ops->rules_list, list)
 365                call_fib_rule_notifier(nb, net, FIB_EVENT_RULE_ADD, rule,
 366                                       family);
 367        rules_ops_put(ops);
 368
 369        return 0;
 370}
 371EXPORT_SYMBOL_GPL(fib_rules_dump);
 372
 373unsigned int fib_rules_seq_read(struct net *net, int family)
 374{
 375        unsigned int fib_rules_seq;
 376        struct fib_rules_ops *ops;
 377
 378        ASSERT_RTNL();
 379
 380        ops = lookup_rules_ops(net, family);
 381        if (!ops)
 382                return 0;
 383        fib_rules_seq = ops->fib_rules_seq;
 384        rules_ops_put(ops);
 385
 386        return fib_rules_seq;
 387}
 388EXPORT_SYMBOL_GPL(fib_rules_seq_read);
 389
 390static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb,
 391                            struct fib_rules_ops *ops)
 392{
 393        int err = -EINVAL;
 394
 395        if (frh->src_len)
 396                if (tb[FRA_SRC] == NULL ||
 397                    frh->src_len > (ops->addr_size * 8) ||
 398                    nla_len(tb[FRA_SRC]) != ops->addr_size)
 399                        goto errout;
 400
 401        if (frh->dst_len)
 402                if (tb[FRA_DST] == NULL ||
 403                    frh->dst_len > (ops->addr_size * 8) ||
 404                    nla_len(tb[FRA_DST]) != ops->addr_size)
 405                        goto errout;
 406
 407        err = 0;
 408errout:
 409        return err;
 410}
 411
 412static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh,
 413                       struct nlattr **tb, struct fib_rule *rule)
 414{
 415        struct fib_rule *r;
 416
 417        list_for_each_entry(r, &ops->rules_list, list) {
 418                if (r->action != rule->action)
 419                        continue;
 420
 421                if (r->table != rule->table)
 422                        continue;
 423
 424                if (r->pref != rule->pref)
 425                        continue;
 426
 427                if (memcmp(r->iifname, rule->iifname, IFNAMSIZ))
 428                        continue;
 429
 430                if (memcmp(r->oifname, rule->oifname, IFNAMSIZ))
 431                        continue;
 432
 433                if (r->mark != rule->mark)
 434                        continue;
 435
 436                if (r->mark_mask != rule->mark_mask)
 437                        continue;
 438
 439                if (r->tun_id != rule->tun_id)
 440                        continue;
 441
 442                if (r->fr_net != rule->fr_net)
 443                        continue;
 444
 445                if (r->l3mdev != rule->l3mdev)
 446                        continue;
 447
 448                if (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
 449                    !uid_eq(r->uid_range.end, rule->uid_range.end))
 450                        continue;
 451
 452                if (r->ip_proto != rule->ip_proto)
 453                        continue;
 454
 455                if (!fib_rule_port_range_compare(&r->sport_range,
 456                                                 &rule->sport_range))
 457                        continue;
 458
 459                if (!fib_rule_port_range_compare(&r->dport_range,
 460                                                 &rule->dport_range))
 461                        continue;
 462
 463                if (!ops->compare(r, frh, tb))
 464                        continue;
 465                return 1;
 466        }
 467        return 0;
 468}
 469
 470int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
 471                   struct netlink_ext_ack *extack)
 472{
 473        struct net *net = sock_net(skb->sk);
 474        struct fib_rule_hdr *frh = nlmsg_data(nlh);
 475        struct fib_rules_ops *ops = NULL;
 476        struct fib_rule *rule, *r, *last = NULL;
 477        struct nlattr *tb[FRA_MAX+1];
 478        int err = -EINVAL, unresolved = 0;
 479
 480        if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 481                goto errout;
 482
 483        ops = lookup_rules_ops(net, frh->family);
 484        if (ops == NULL) {
 485                err = -EAFNOSUPPORT;
 486                goto errout;
 487        }
 488
 489        err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack);
 490        if (err < 0)
 491                goto errout;
 492
 493        err = validate_rulemsg(frh, tb, ops);
 494        if (err < 0)
 495                goto errout;
 496
 497        rule = kzalloc(ops->rule_size, GFP_KERNEL);
 498        if (rule == NULL) {
 499                err = -ENOMEM;
 500                goto errout;
 501        }
 502        refcount_set(&rule->refcnt, 1);
 503        rule->fr_net = net;
 504
 505        rule->pref = tb[FRA_PRIORITY] ? nla_get_u32(tb[FRA_PRIORITY])
 506                                      : fib_default_rule_pref(ops);
 507
 508        rule->proto = tb[FRA_PROTOCOL] ?
 509                nla_get_u8(tb[FRA_PROTOCOL]) : RTPROT_UNSPEC;
 510
 511        if (tb[FRA_IIFNAME]) {
 512                struct net_device *dev;
 513
 514                rule->iifindex = -1;
 515                nla_strlcpy(rule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
 516                dev = __dev_get_by_name(net, rule->iifname);
 517                if (dev)
 518                        rule->iifindex = dev->ifindex;
 519        }
 520
 521        if (tb[FRA_OIFNAME]) {
 522                struct net_device *dev;
 523
 524                rule->oifindex = -1;
 525                nla_strlcpy(rule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
 526                dev = __dev_get_by_name(net, rule->oifname);
 527                if (dev)
 528                        rule->oifindex = dev->ifindex;
 529        }
 530
 531        if (tb[FRA_FWMARK]) {
 532                rule->mark = nla_get_u32(tb[FRA_FWMARK]);
 533                if (rule->mark)
 534                        /* compatibility: if the mark value is non-zero all bits
 535                         * are compared unless a mask is explicitly specified.
 536                         */
 537                        rule->mark_mask = 0xFFFFFFFF;
 538        }
 539
 540        if (tb[FRA_FWMASK])
 541                rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
 542
 543        if (tb[FRA_TUN_ID])
 544                rule->tun_id = nla_get_be64(tb[FRA_TUN_ID]);
 545
 546        err = -EINVAL;
 547        if (tb[FRA_L3MDEV]) {
 548#ifdef CONFIG_NET_L3_MASTER_DEV
 549                rule->l3mdev = nla_get_u8(tb[FRA_L3MDEV]);
 550                if (rule->l3mdev != 1)
 551#endif
 552                        goto errout_free;
 553        }
 554
 555        rule->action = frh->action;
 556        rule->flags = frh->flags;
 557        rule->table = frh_get_table(frh, tb);
 558        if (tb[FRA_SUPPRESS_PREFIXLEN])
 559                rule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
 560        else
 561                rule->suppress_prefixlen = -1;
 562
 563        if (tb[FRA_SUPPRESS_IFGROUP])
 564                rule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
 565        else
 566                rule->suppress_ifgroup = -1;
 567
 568        if (tb[FRA_GOTO]) {
 569                if (rule->action != FR_ACT_GOTO)
 570                        goto errout_free;
 571
 572                rule->target = nla_get_u32(tb[FRA_GOTO]);
 573                /* Backward jumps are prohibited to avoid endless loops */
 574                if (rule->target <= rule->pref)
 575                        goto errout_free;
 576
 577                list_for_each_entry(r, &ops->rules_list, list) {
 578                        if (r->pref == rule->target) {
 579                                RCU_INIT_POINTER(rule->ctarget, r);
 580                                break;
 581                        }
 582                }
 583
 584                if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
 585                        unresolved = 1;
 586        } else if (rule->action == FR_ACT_GOTO)
 587                goto errout_free;
 588
 589        if (rule->l3mdev && rule->table)
 590                goto errout_free;
 591
 592        if (tb[FRA_UID_RANGE]) {
 593                if (current_user_ns() != net->user_ns) {
 594                        err = -EPERM;
 595                        goto errout_free;
 596                }
 597
 598                rule->uid_range = nla_get_kuid_range(tb);
 599
 600                if (!uid_range_set(&rule->uid_range) ||
 601                    !uid_lte(rule->uid_range.start, rule->uid_range.end))
 602                        goto errout_free;
 603        } else {
 604                rule->uid_range = fib_kuid_range_unset;
 605        }
 606
 607        if (tb[FRA_IP_PROTO])
 608                rule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]);
 609
 610        if (tb[FRA_SPORT_RANGE]) {
 611                err = nla_get_port_range(tb[FRA_SPORT_RANGE],
 612                                         &rule->sport_range);
 613                if (err)
 614                        goto errout_free;
 615        }
 616
 617        if (tb[FRA_DPORT_RANGE]) {
 618                err = nla_get_port_range(tb[FRA_DPORT_RANGE],
 619                                         &rule->dport_range);
 620                if (err)
 621                        goto errout_free;
 622        }
 623
 624        if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
 625            rule_exists(ops, frh, tb, rule)) {
 626                err = -EEXIST;
 627                goto errout_free;
 628        }
 629
 630        err = ops->configure(rule, skb, frh, tb);
 631        if (err < 0)
 632                goto errout_free;
 633
 634        err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops,
 635                                      extack);
 636        if (err < 0)
 637                goto errout_free;
 638
 639        list_for_each_entry(r, &ops->rules_list, list) {
 640                if (r->pref > rule->pref)
 641                        break;
 642                last = r;
 643        }
 644
 645        if (last)
 646                list_add_rcu(&rule->list, &last->list);
 647        else
 648                list_add_rcu(&rule->list, &ops->rules_list);
 649
 650        if (ops->unresolved_rules) {
 651                /*
 652                 * There are unresolved goto rules in the list, check if
 653                 * any of them are pointing to this new rule.
 654                 */
 655                list_for_each_entry(r, &ops->rules_list, list) {
 656                        if (r->action == FR_ACT_GOTO &&
 657                            r->target == rule->pref &&
 658                            rtnl_dereference(r->ctarget) == NULL) {
 659                                rcu_assign_pointer(r->ctarget, rule);
 660                                if (--ops->unresolved_rules == 0)
 661                                        break;
 662                        }
 663                }
 664        }
 665
 666        if (rule->action == FR_ACT_GOTO)
 667                ops->nr_goto_rules++;
 668
 669        if (unresolved)
 670                ops->unresolved_rules++;
 671
 672        if (rule->tun_id)
 673                ip_tunnel_need_metadata();
 674
 675        notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
 676        flush_route_cache(ops);
 677        rules_ops_put(ops);
 678        return 0;
 679
 680errout_free:
 681        kfree(rule);
 682errout:
 683        rules_ops_put(ops);
 684        return err;
 685}
 686EXPORT_SYMBOL_GPL(fib_nl_newrule);
 687
 688int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
 689                   struct netlink_ext_ack *extack)
 690{
 691        struct net *net = sock_net(skb->sk);
 692        struct fib_rule_hdr *frh = nlmsg_data(nlh);
 693        struct fib_rule_port_range sprange = {0, 0};
 694        struct fib_rule_port_range dprange = {0, 0};
 695        struct fib_rules_ops *ops = NULL;
 696        struct fib_rule *rule, *r;
 697        struct nlattr *tb[FRA_MAX+1];
 698        struct fib_kuid_range range;
 699        int err = -EINVAL;
 700
 701        if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 702                goto errout;
 703
 704        ops = lookup_rules_ops(net, frh->family);
 705        if (ops == NULL) {
 706                err = -EAFNOSUPPORT;
 707                goto errout;
 708        }
 709
 710        err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack);
 711        if (err < 0)
 712                goto errout;
 713
 714        err = validate_rulemsg(frh, tb, ops);
 715        if (err < 0)
 716                goto errout;
 717
 718        if (tb[FRA_UID_RANGE]) {
 719                range = nla_get_kuid_range(tb);
 720                if (!uid_range_set(&range)) {
 721                        err = -EINVAL;
 722                        goto errout;
 723                }
 724        } else {
 725                range = fib_kuid_range_unset;
 726        }
 727
 728        if (tb[FRA_SPORT_RANGE]) {
 729                err = nla_get_port_range(tb[FRA_SPORT_RANGE],
 730                                         &sprange);
 731                if (err)
 732                        goto errout;
 733        }
 734
 735        if (tb[FRA_DPORT_RANGE]) {
 736                err = nla_get_port_range(tb[FRA_DPORT_RANGE],
 737                                         &dprange);
 738                if (err)
 739                        goto errout;
 740        }
 741
 742        list_for_each_entry(rule, &ops->rules_list, list) {
 743                if (tb[FRA_PROTOCOL] &&
 744                    (rule->proto != nla_get_u8(tb[FRA_PROTOCOL])))
 745                        continue;
 746
 747                if (frh->action && (frh->action != rule->action))
 748                        continue;
 749
 750                if (frh_get_table(frh, tb) &&
 751                    (frh_get_table(frh, tb) != rule->table))
 752                        continue;
 753
 754                if (tb[FRA_PRIORITY] &&
 755                    (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
 756                        continue;
 757
 758                if (tb[FRA_IIFNAME] &&
 759                    nla_strcmp(tb[FRA_IIFNAME], rule->iifname))
 760                        continue;
 761
 762                if (tb[FRA_OIFNAME] &&
 763                    nla_strcmp(tb[FRA_OIFNAME], rule->oifname))
 764                        continue;
 765
 766                if (tb[FRA_FWMARK] &&
 767                    (rule->mark != nla_get_u32(tb[FRA_FWMARK])))
 768                        continue;
 769
 770                if (tb[FRA_FWMASK] &&
 771                    (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK])))
 772                        continue;
 773
 774                if (tb[FRA_TUN_ID] &&
 775                    (rule->tun_id != nla_get_be64(tb[FRA_TUN_ID])))
 776                        continue;
 777
 778                if (tb[FRA_L3MDEV] &&
 779                    (rule->l3mdev != nla_get_u8(tb[FRA_L3MDEV])))
 780                        continue;
 781
 782                if (uid_range_set(&range) &&
 783                    (!uid_eq(rule->uid_range.start, range.start) ||
 784                     !uid_eq(rule->uid_range.end, range.end)))
 785                        continue;
 786
 787                if (tb[FRA_IP_PROTO] &&
 788                    (rule->ip_proto != nla_get_u8(tb[FRA_IP_PROTO])))
 789                        continue;
 790
 791                if (fib_rule_port_range_set(&sprange) &&
 792                    !fib_rule_port_range_compare(&rule->sport_range, &sprange))
 793                        continue;
 794
 795                if (fib_rule_port_range_set(&dprange) &&
 796                    !fib_rule_port_range_compare(&rule->dport_range, &dprange))
 797                        continue;
 798
 799                if (!ops->compare(rule, frh, tb))
 800                        continue;
 801
 802                if (rule->flags & FIB_RULE_PERMANENT) {
 803                        err = -EPERM;
 804                        goto errout;
 805                }
 806
 807                if (ops->delete) {
 808                        err = ops->delete(rule);
 809                        if (err)
 810                                goto errout;
 811                }
 812
 813                if (rule->tun_id)
 814                        ip_tunnel_unneed_metadata();
 815
 816                list_del_rcu(&rule->list);
 817
 818                if (rule->action == FR_ACT_GOTO) {
 819                        ops->nr_goto_rules--;
 820                        if (rtnl_dereference(rule->ctarget) == NULL)
 821                                ops->unresolved_rules--;
 822                }
 823
 824                /*
 825                 * Check if this rule is a target to any of them. If so,
 826                 * adjust to the next one with the same preference or
 827                 * disable them. As this operation is eventually very
 828                 * expensive, it is only performed if goto rules, except
 829                 * current if it is goto rule, have actually been added.
 830                 */
 831                if (ops->nr_goto_rules > 0) {
 832                        struct fib_rule *n;
 833
 834                        n = list_next_entry(rule, list);
 835                        if (&n->list == &ops->rules_list || n->pref != rule->pref)
 836                                n = NULL;
 837                        list_for_each_entry(r, &ops->rules_list, list) {
 838                                if (rtnl_dereference(r->ctarget) != rule)
 839                                        continue;
 840                                rcu_assign_pointer(r->ctarget, n);
 841                                if (!n)
 842                                        ops->unresolved_rules++;
 843                        }
 844                }
 845
 846                call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops,
 847                                        NULL);
 848                notify_rule_change(RTM_DELRULE, rule, ops, nlh,
 849                                   NETLINK_CB(skb).portid);
 850                fib_rule_put(rule);
 851                flush_route_cache(ops);
 852                rules_ops_put(ops);
 853                return 0;
 854        }
 855
 856        err = -ENOENT;
 857errout:
 858        rules_ops_put(ops);
 859        return err;
 860}
 861EXPORT_SYMBOL_GPL(fib_nl_delrule);
 862
 863static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
 864                                         struct fib_rule *rule)
 865{
 866        size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
 867                         + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
 868                         + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
 869                         + nla_total_size(4) /* FRA_PRIORITY */
 870                         + nla_total_size(4) /* FRA_TABLE */
 871                         + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
 872                         + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
 873                         + nla_total_size(4) /* FRA_FWMARK */
 874                         + nla_total_size(4) /* FRA_FWMASK */
 875                         + nla_total_size_64bit(8) /* FRA_TUN_ID */
 876                         + nla_total_size(sizeof(struct fib_kuid_range))
 877                         + nla_total_size(1) /* FRA_PROTOCOL */
 878                         + nla_total_size(1) /* FRA_IP_PROTO */
 879                         + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */
 880                         + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */
 881
 882        if (ops->nlmsg_payload)
 883                payload += ops->nlmsg_payload(rule);
 884
 885        return payload;
 886}
 887
 888static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
 889                            u32 pid, u32 seq, int type, int flags,
 890                            struct fib_rules_ops *ops)
 891{
 892        struct nlmsghdr *nlh;
 893        struct fib_rule_hdr *frh;
 894
 895        nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
 896        if (nlh == NULL)
 897                return -EMSGSIZE;
 898
 899        frh = nlmsg_data(nlh);
 900        frh->family = ops->family;
 901        frh->table = rule->table;
 902        if (nla_put_u32(skb, FRA_TABLE, rule->table))
 903                goto nla_put_failure;
 904        if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
 905                goto nla_put_failure;
 906        frh->res1 = 0;
 907        frh->res2 = 0;
 908        frh->action = rule->action;
 909        frh->flags = rule->flags;
 910
 911        if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto))
 912                goto nla_put_failure;
 913
 914        if (rule->action == FR_ACT_GOTO &&
 915            rcu_access_pointer(rule->ctarget) == NULL)
 916                frh->flags |= FIB_RULE_UNRESOLVED;
 917
 918        if (rule->iifname[0]) {
 919                if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
 920                        goto nla_put_failure;
 921                if (rule->iifindex == -1)
 922                        frh->flags |= FIB_RULE_IIF_DETACHED;
 923        }
 924
 925        if (rule->oifname[0]) {
 926                if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
 927                        goto nla_put_failure;
 928                if (rule->oifindex == -1)
 929                        frh->flags |= FIB_RULE_OIF_DETACHED;
 930        }
 931
 932        if ((rule->pref &&
 933             nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
 934            (rule->mark &&
 935             nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
 936            ((rule->mark_mask || rule->mark) &&
 937             nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
 938            (rule->target &&
 939             nla_put_u32(skb, FRA_GOTO, rule->target)) ||
 940            (rule->tun_id &&
 941             nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) ||
 942            (rule->l3mdev &&
 943             nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) ||
 944            (uid_range_set(&rule->uid_range) &&
 945             nla_put_uid_range(skb, &rule->uid_range)) ||
 946            (fib_rule_port_range_set(&rule->sport_range) &&
 947             nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) ||
 948            (fib_rule_port_range_set(&rule->dport_range) &&
 949             nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) ||
 950            (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto)))
 951                goto nla_put_failure;
 952
 953        if (rule->suppress_ifgroup != -1) {
 954                if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
 955                        goto nla_put_failure;
 956        }
 957
 958        if (ops->fill(rule, skb, frh) < 0)
 959                goto nla_put_failure;
 960
 961        nlmsg_end(skb, nlh);
 962        return 0;
 963
 964nla_put_failure:
 965        nlmsg_cancel(skb, nlh);
 966        return -EMSGSIZE;
 967}
 968
 969static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
 970                      struct fib_rules_ops *ops)
 971{
 972        int idx = 0;
 973        struct fib_rule *rule;
 974        int err = 0;
 975
 976        rcu_read_lock();
 977        list_for_each_entry_rcu(rule, &ops->rules_list, list) {
 978                if (idx < cb->args[1])
 979                        goto skip;
 980
 981                err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
 982                                       cb->nlh->nlmsg_seq, RTM_NEWRULE,
 983                                       NLM_F_MULTI, ops);
 984                if (err)
 985                        break;
 986skip:
 987                idx++;
 988        }
 989        rcu_read_unlock();
 990        cb->args[1] = idx;
 991        rules_ops_put(ops);
 992
 993        return err;
 994}
 995
 996static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
 997{
 998        struct net *net = sock_net(skb->sk);
 999        struct fib_rules_ops *ops;
1000        int idx = 0, family;
1001
1002        family = rtnl_msg_family(cb->nlh);
1003        if (family != AF_UNSPEC) {
1004                /* Protocol specific dump request */
1005                ops = lookup_rules_ops(net, family);
1006                if (ops == NULL)
1007                        return -EAFNOSUPPORT;
1008
1009                dump_rules(skb, cb, ops);
1010
1011                return skb->len;
1012        }
1013
1014        rcu_read_lock();
1015        list_for_each_entry_rcu(ops, &net->rules_ops, list) {
1016                if (idx < cb->args[0] || !try_module_get(ops->owner))
1017                        goto skip;
1018
1019                if (dump_rules(skb, cb, ops) < 0)
1020                        break;
1021
1022                cb->args[1] = 0;
1023skip:
1024                idx++;
1025        }
1026        rcu_read_unlock();
1027        cb->args[0] = idx;
1028
1029        return skb->len;
1030}
1031
1032static void notify_rule_change(int event, struct fib_rule *rule,
1033                               struct fib_rules_ops *ops, struct nlmsghdr *nlh,
1034                               u32 pid)
1035{
1036        struct net *net;
1037        struct sk_buff *skb;
1038        int err = -ENOBUFS;
1039
1040        net = ops->fro_net;
1041        skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
1042        if (skb == NULL)
1043                goto errout;
1044
1045        err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
1046        if (err < 0) {
1047                /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
1048                WARN_ON(err == -EMSGSIZE);
1049                kfree_skb(skb);
1050                goto errout;
1051        }
1052
1053        rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
1054        return;
1055errout:
1056        if (err < 0)
1057                rtnl_set_sk_err(net, ops->nlgroup, err);
1058}
1059
1060static void attach_rules(struct list_head *rules, struct net_device *dev)
1061{
1062        struct fib_rule *rule;
1063
1064        list_for_each_entry(rule, rules, list) {
1065                if (rule->iifindex == -1 &&
1066                    strcmp(dev->name, rule->iifname) == 0)
1067                        rule->iifindex = dev->ifindex;
1068                if (rule->oifindex == -1 &&
1069                    strcmp(dev->name, rule->oifname) == 0)
1070                        rule->oifindex = dev->ifindex;
1071        }
1072}
1073
1074static void detach_rules(struct list_head *rules, struct net_device *dev)
1075{
1076        struct fib_rule *rule;
1077
1078        list_for_each_entry(rule, rules, list) {
1079                if (rule->iifindex == dev->ifindex)
1080                        rule->iifindex = -1;
1081                if (rule->oifindex == dev->ifindex)
1082                        rule->oifindex = -1;
1083        }
1084}
1085
1086
1087static int fib_rules_event(struct notifier_block *this, unsigned long event,
1088                           void *ptr)
1089{
1090        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1091        struct net *net = dev_net(dev);
1092        struct fib_rules_ops *ops;
1093
1094        ASSERT_RTNL();
1095
1096        switch (event) {
1097        case NETDEV_REGISTER:
1098                list_for_each_entry(ops, &net->rules_ops, list)
1099                        attach_rules(&ops->rules_list, dev);
1100                break;
1101
1102        case NETDEV_CHANGENAME:
1103                list_for_each_entry(ops, &net->rules_ops, list) {
1104                        detach_rules(&ops->rules_list, dev);
1105                        attach_rules(&ops->rules_list, dev);
1106                }
1107                break;
1108
1109        case NETDEV_UNREGISTER:
1110                list_for_each_entry(ops, &net->rules_ops, list)
1111                        detach_rules(&ops->rules_list, dev);
1112                break;
1113        }
1114
1115        return NOTIFY_DONE;
1116}
1117
1118static struct notifier_block fib_rules_notifier = {
1119        .notifier_call = fib_rules_event,
1120};
1121
1122static int __net_init fib_rules_net_init(struct net *net)
1123{
1124        INIT_LIST_HEAD(&net->rules_ops);
1125        spin_lock_init(&net->rules_mod_lock);
1126        return 0;
1127}
1128
1129static void __net_exit fib_rules_net_exit(struct net *net)
1130{
1131        WARN_ON_ONCE(!list_empty(&net->rules_ops));
1132}
1133
1134static struct pernet_operations fib_rules_net_ops = {
1135        .init = fib_rules_net_init,
1136        .exit = fib_rules_net_exit,
1137};
1138
1139static int __init fib_rules_init(void)
1140{
1141        int err;
1142        rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, 0);
1143        rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, 0);
1144        rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, 0);
1145
1146        err = register_pernet_subsys(&fib_rules_net_ops);
1147        if (err < 0)
1148                goto fail;
1149
1150        err = register_netdevice_notifier(&fib_rules_notifier);
1151        if (err < 0)
1152                goto fail_unregister;
1153
1154        return 0;
1155
1156fail_unregister:
1157        unregister_pernet_subsys(&fib_rules_net_ops);
1158fail:
1159        rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
1160        rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
1161        rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
1162        return err;
1163}
1164
1165subsys_initcall(fib_rules_init);
1166