linux/net/netfilter/nfnetlink_cthelper.c
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   1/*
   2 * (C) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License version 2 as
   6 * published by the Free Software Foundation (or any later at your option).
   7 *
   8 * This software has been sponsored by Vyatta Inc. <http://www.vyatta.com>
   9 */
  10#include <linux/init.h>
  11#include <linux/module.h>
  12#include <linux/kernel.h>
  13#include <linux/skbuff.h>
  14#include <linux/netlink.h>
  15#include <linux/rculist.h>
  16#include <linux/slab.h>
  17#include <linux/types.h>
  18#include <linux/list.h>
  19#include <linux/errno.h>
  20#include <net/netlink.h>
  21#include <net/sock.h>
  22
  23#include <net/netfilter/nf_conntrack_helper.h>
  24#include <net/netfilter/nf_conntrack_expect.h>
  25#include <net/netfilter/nf_conntrack_ecache.h>
  26
  27#include <linux/netfilter/nfnetlink.h>
  28#include <linux/netfilter/nfnetlink_conntrack.h>
  29#include <linux/netfilter/nfnetlink_cthelper.h>
  30
  31MODULE_LICENSE("GPL");
  32MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
  33MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers");
  34
  35static int
  36nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff,
  37                        struct nf_conn *ct, enum ip_conntrack_info ctinfo)
  38{
  39        const struct nf_conn_help *help;
  40        struct nf_conntrack_helper *helper;
  41
  42        help = nfct_help(ct);
  43        if (help == NULL)
  44                return NF_DROP;
  45
  46        /* rcu_read_lock()ed by nf_hook_slow */
  47        helper = rcu_dereference(help->helper);
  48        if (helper == NULL)
  49                return NF_DROP;
  50
  51        /* This is an user-space helper not yet configured, skip. */
  52        if ((helper->flags &
  53            (NF_CT_HELPER_F_USERSPACE | NF_CT_HELPER_F_CONFIGURED)) ==
  54             NF_CT_HELPER_F_USERSPACE)
  55                return NF_ACCEPT;
  56
  57        /* If the user-space helper is not available, don't block traffic. */
  58        return NF_QUEUE_NR(helper->queue_num) | NF_VERDICT_FLAG_QUEUE_BYPASS;
  59}
  60
  61static const struct nla_policy nfnl_cthelper_tuple_pol[NFCTH_TUPLE_MAX+1] = {
  62        [NFCTH_TUPLE_L3PROTONUM] = { .type = NLA_U16, },
  63        [NFCTH_TUPLE_L4PROTONUM] = { .type = NLA_U8, },
  64};
  65
  66static int
  67nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple,
  68                          const struct nlattr *attr)
  69{
  70        struct nlattr *tb[NFCTH_TUPLE_MAX+1];
  71
  72        nla_parse_nested(tb, NFCTH_TUPLE_MAX, attr, nfnl_cthelper_tuple_pol);
  73
  74        if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM])
  75                return -EINVAL;
  76
  77        tuple->src.l3num = ntohs(nla_get_u16(tb[NFCTH_TUPLE_L3PROTONUM]));
  78        tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]);
  79
  80        return 0;
  81}
  82
  83static int
  84nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct)
  85{
  86        const struct nf_conn_help *help = nfct_help(ct);
  87
  88        if (help->helper->data_len == 0)
  89                return -EINVAL;
  90
  91        memcpy(&help->data, nla_data(attr), help->helper->data_len);
  92        return 0;
  93}
  94
  95static int
  96nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct)
  97{
  98        const struct nf_conn_help *help = nfct_help(ct);
  99
 100        if (help->helper->data_len &&
 101            nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data))
 102                goto nla_put_failure;
 103
 104        return 0;
 105
 106nla_put_failure:
 107        return -ENOSPC;
 108}
 109
 110static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = {
 111        [NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING,
 112                                .len = NF_CT_HELPER_NAME_LEN-1 },
 113        [NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, },
 114        [NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, },
 115};
 116
 117static int
 118nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy,
 119                            const struct nlattr *attr)
 120{
 121        struct nlattr *tb[NFCTH_POLICY_MAX+1];
 122
 123        nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, nfnl_cthelper_expect_pol);
 124
 125        if (!tb[NFCTH_POLICY_NAME] ||
 126            !tb[NFCTH_POLICY_EXPECT_MAX] ||
 127            !tb[NFCTH_POLICY_EXPECT_TIMEOUT])
 128                return -EINVAL;
 129
 130        strncpy(expect_policy->name,
 131                nla_data(tb[NFCTH_POLICY_NAME]), NF_CT_HELPER_NAME_LEN);
 132        expect_policy->max_expected =
 133                ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX]));
 134        expect_policy->timeout =
 135                ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT]));
 136
 137        return 0;
 138}
 139
 140static const struct nla_policy
 141nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = {
 142        [NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, },
 143};
 144
 145static int
 146nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper,
 147                                  const struct nlattr *attr)
 148{
 149        int i, ret;
 150        struct nf_conntrack_expect_policy *expect_policy;
 151        struct nlattr *tb[NFCTH_POLICY_SET_MAX+1];
 152
 153        nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr,
 154                                        nfnl_cthelper_expect_policy_set);
 155
 156        if (!tb[NFCTH_POLICY_SET_NUM])
 157                return -EINVAL;
 158
 159        helper->expect_class_max =
 160                ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM]));
 161
 162        if (helper->expect_class_max != 0 &&
 163            helper->expect_class_max > NF_CT_MAX_EXPECT_CLASSES)
 164                return -EOVERFLOW;
 165
 166        expect_policy = kzalloc(sizeof(struct nf_conntrack_expect_policy) *
 167                                helper->expect_class_max, GFP_KERNEL);
 168        if (expect_policy == NULL)
 169                return -ENOMEM;
 170
 171        for (i=0; i<helper->expect_class_max; i++) {
 172                if (!tb[NFCTH_POLICY_SET+i])
 173                        goto err;
 174
 175                ret = nfnl_cthelper_expect_policy(&expect_policy[i],
 176                                                  tb[NFCTH_POLICY_SET+i]);
 177                if (ret < 0)
 178                        goto err;
 179        }
 180        helper->expect_policy = expect_policy;
 181        return 0;
 182err:
 183        kfree(expect_policy);
 184        return -EINVAL;
 185}
 186
 187static int
 188nfnl_cthelper_create(const struct nlattr * const tb[],
 189                     struct nf_conntrack_tuple *tuple)
 190{
 191        struct nf_conntrack_helper *helper;
 192        int ret;
 193
 194        if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN])
 195                return -EINVAL;
 196
 197        helper = kzalloc(sizeof(struct nf_conntrack_helper), GFP_KERNEL);
 198        if (helper == NULL)
 199                return -ENOMEM;
 200
 201        ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]);
 202        if (ret < 0)
 203                goto err;
 204
 205        strncpy(helper->name, nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN);
 206        helper->data_len = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN]));
 207        helper->flags |= NF_CT_HELPER_F_USERSPACE;
 208        memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple));
 209
 210        helper->me = THIS_MODULE;
 211        helper->help = nfnl_userspace_cthelper;
 212        helper->from_nlattr = nfnl_cthelper_from_nlattr;
 213        helper->to_nlattr = nfnl_cthelper_to_nlattr;
 214
 215        /* Default to queue number zero, this can be updated at any time. */
 216        if (tb[NFCTH_QUEUE_NUM])
 217                helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
 218
 219        if (tb[NFCTH_STATUS]) {
 220                int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
 221
 222                switch(status) {
 223                case NFCT_HELPER_STATUS_ENABLED:
 224                        helper->flags |= NF_CT_HELPER_F_CONFIGURED;
 225                        break;
 226                case NFCT_HELPER_STATUS_DISABLED:
 227                        helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
 228                        break;
 229                }
 230        }
 231
 232        ret = nf_conntrack_helper_register(helper);
 233        if (ret < 0)
 234                goto err;
 235
 236        return 0;
 237err:
 238        kfree(helper);
 239        return ret;
 240}
 241
 242static int
 243nfnl_cthelper_update(const struct nlattr * const tb[],
 244                     struct nf_conntrack_helper *helper)
 245{
 246        int ret;
 247
 248        if (tb[NFCTH_PRIV_DATA_LEN])
 249                return -EBUSY;
 250
 251        if (tb[NFCTH_POLICY]) {
 252                ret = nfnl_cthelper_parse_expect_policy(helper,
 253                                                        tb[NFCTH_POLICY]);
 254                if (ret < 0)
 255                        return ret;
 256        }
 257        if (tb[NFCTH_QUEUE_NUM])
 258                helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
 259
 260        if (tb[NFCTH_STATUS]) {
 261                int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
 262
 263                switch(status) {
 264                case NFCT_HELPER_STATUS_ENABLED:
 265                        helper->flags |= NF_CT_HELPER_F_CONFIGURED;
 266                        break;
 267                case NFCT_HELPER_STATUS_DISABLED:
 268                        helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
 269                        break;
 270                }
 271        }
 272        return 0;
 273}
 274
 275static int
 276nfnl_cthelper_new(struct sock *nfnl, struct sk_buff *skb,
 277                  const struct nlmsghdr *nlh, const struct nlattr * const tb[])
 278{
 279        const char *helper_name;
 280        struct nf_conntrack_helper *cur, *helper = NULL;
 281        struct nf_conntrack_tuple tuple;
 282        struct hlist_node *n;
 283        int ret = 0, i;
 284
 285        if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE])
 286                return -EINVAL;
 287
 288        helper_name = nla_data(tb[NFCTH_NAME]);
 289
 290        ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
 291        if (ret < 0)
 292                return ret;
 293
 294        rcu_read_lock();
 295        for (i = 0; i < nf_ct_helper_hsize && !helper; i++) {
 296                hlist_for_each_entry_rcu(cur, n, &nf_ct_helper_hash[i], hnode) {
 297
 298                        /* skip non-userspace conntrack helpers. */
 299                        if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
 300                                continue;
 301
 302                        if (strncmp(cur->name, helper_name,
 303                                        NF_CT_HELPER_NAME_LEN) != 0)
 304                                continue;
 305
 306                        if ((tuple.src.l3num != cur->tuple.src.l3num ||
 307                             tuple.dst.protonum != cur->tuple.dst.protonum))
 308                                continue;
 309
 310                        if (nlh->nlmsg_flags & NLM_F_EXCL) {
 311                                ret = -EEXIST;
 312                                goto err;
 313                        }
 314                        helper = cur;
 315                        break;
 316                }
 317        }
 318        rcu_read_unlock();
 319
 320        if (helper == NULL)
 321                ret = nfnl_cthelper_create(tb, &tuple);
 322        else
 323                ret = nfnl_cthelper_update(tb, helper);
 324
 325        return ret;
 326err:
 327        rcu_read_unlock();
 328        return ret;
 329}
 330
 331static int
 332nfnl_cthelper_dump_tuple(struct sk_buff *skb,
 333                         struct nf_conntrack_helper *helper)
 334{
 335        struct nlattr *nest_parms;
 336
 337        nest_parms = nla_nest_start(skb, NFCTH_TUPLE | NLA_F_NESTED);
 338        if (nest_parms == NULL)
 339                goto nla_put_failure;
 340
 341        if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM,
 342                         htons(helper->tuple.src.l3num)))
 343                goto nla_put_failure;
 344
 345        if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum))
 346                goto nla_put_failure;
 347
 348        nla_nest_end(skb, nest_parms);
 349        return 0;
 350
 351nla_put_failure:
 352        return -1;
 353}
 354
 355static int
 356nfnl_cthelper_dump_policy(struct sk_buff *skb,
 357                        struct nf_conntrack_helper *helper)
 358{
 359        int i;
 360        struct nlattr *nest_parms1, *nest_parms2;
 361
 362        nest_parms1 = nla_nest_start(skb, NFCTH_POLICY | NLA_F_NESTED);
 363        if (nest_parms1 == NULL)
 364                goto nla_put_failure;
 365
 366        if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM,
 367                         htonl(helper->expect_class_max)))
 368                goto nla_put_failure;
 369
 370        for (i=0; i<helper->expect_class_max; i++) {
 371                nest_parms2 = nla_nest_start(skb,
 372                                (NFCTH_POLICY_SET+i) | NLA_F_NESTED);
 373                if (nest_parms2 == NULL)
 374                        goto nla_put_failure;
 375
 376                if (nla_put_string(skb, NFCTH_POLICY_NAME,
 377                                   helper->expect_policy[i].name))
 378                        goto nla_put_failure;
 379
 380                if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX,
 381                                 htonl(helper->expect_policy[i].max_expected)))
 382                        goto nla_put_failure;
 383
 384                if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT,
 385                                 htonl(helper->expect_policy[i].timeout)))
 386                        goto nla_put_failure;
 387
 388                nla_nest_end(skb, nest_parms2);
 389        }
 390        nla_nest_end(skb, nest_parms1);
 391        return 0;
 392
 393nla_put_failure:
 394        return -1;
 395}
 396
 397static int
 398nfnl_cthelper_fill_info(struct sk_buff *skb, u32 pid, u32 seq, u32 type,
 399                        int event, struct nf_conntrack_helper *helper)
 400{
 401        struct nlmsghdr *nlh;
 402        struct nfgenmsg *nfmsg;
 403        unsigned int flags = pid ? NLM_F_MULTI : 0;
 404        int status;
 405
 406        event |= NFNL_SUBSYS_CTHELPER << 8;
 407        nlh = nlmsg_put(skb, pid, seq, event, sizeof(*nfmsg), flags);
 408        if (nlh == NULL)
 409                goto nlmsg_failure;
 410
 411        nfmsg = nlmsg_data(nlh);
 412        nfmsg->nfgen_family = AF_UNSPEC;
 413        nfmsg->version = NFNETLINK_V0;
 414        nfmsg->res_id = 0;
 415
 416        if (nla_put_string(skb, NFCTH_NAME, helper->name))
 417                goto nla_put_failure;
 418
 419        if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num)))
 420                goto nla_put_failure;
 421
 422        if (nfnl_cthelper_dump_tuple(skb, helper) < 0)
 423                goto nla_put_failure;
 424
 425        if (nfnl_cthelper_dump_policy(skb, helper) < 0)
 426                goto nla_put_failure;
 427
 428        if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len)))
 429                goto nla_put_failure;
 430
 431        if (helper->flags & NF_CT_HELPER_F_CONFIGURED)
 432                status = NFCT_HELPER_STATUS_ENABLED;
 433        else
 434                status = NFCT_HELPER_STATUS_DISABLED;
 435
 436        if (nla_put_be32(skb, NFCTH_STATUS, htonl(status)))
 437                goto nla_put_failure;
 438
 439        nlmsg_end(skb, nlh);
 440        return skb->len;
 441
 442nlmsg_failure:
 443nla_put_failure:
 444        nlmsg_cancel(skb, nlh);
 445        return -1;
 446}
 447
 448static int
 449nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
 450{
 451        struct nf_conntrack_helper *cur, *last;
 452        struct hlist_node *n;
 453
 454        rcu_read_lock();
 455        last = (struct nf_conntrack_helper *)cb->args[1];
 456        for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) {
 457restart:
 458                hlist_for_each_entry_rcu(cur, n,
 459                                &nf_ct_helper_hash[cb->args[0]], hnode) {
 460
 461                        /* skip non-userspace conntrack helpers. */
 462                        if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
 463                                continue;
 464
 465                        if (cb->args[1]) {
 466                                if (cur != last)
 467                                        continue;
 468                                cb->args[1] = 0;
 469                        }
 470                        if (nfnl_cthelper_fill_info(skb,
 471                                            NETLINK_CB(cb->skb).pid,
 472                                            cb->nlh->nlmsg_seq,
 473                                            NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
 474                                            NFNL_MSG_CTHELPER_NEW, cur) < 0) {
 475                                cb->args[1] = (unsigned long)cur;
 476                                goto out;
 477                        }
 478                }
 479        }
 480        if (cb->args[1]) {
 481                cb->args[1] = 0;
 482                goto restart;
 483        }
 484out:
 485        rcu_read_unlock();
 486        return skb->len;
 487}
 488
 489static int
 490nfnl_cthelper_get(struct sock *nfnl, struct sk_buff *skb,
 491                  const struct nlmsghdr *nlh, const struct nlattr * const tb[])
 492{
 493        int ret = -ENOENT, i;
 494        struct nf_conntrack_helper *cur;
 495        struct hlist_node *n;
 496        struct sk_buff *skb2;
 497        char *helper_name = NULL;
 498        struct nf_conntrack_tuple tuple;
 499        bool tuple_set = false;
 500
 501        if (nlh->nlmsg_flags & NLM_F_DUMP) {
 502                struct netlink_dump_control c = {
 503                        .dump = nfnl_cthelper_dump_table,
 504                };
 505                return netlink_dump_start(nfnl, skb, nlh, &c);
 506        }
 507
 508        if (tb[NFCTH_NAME])
 509                helper_name = nla_data(tb[NFCTH_NAME]);
 510
 511        if (tb[NFCTH_TUPLE]) {
 512                ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
 513                if (ret < 0)
 514                        return ret;
 515
 516                tuple_set = true;
 517        }
 518
 519        for (i = 0; i < nf_ct_helper_hsize; i++) {
 520                hlist_for_each_entry_rcu(cur, n, &nf_ct_helper_hash[i], hnode) {
 521
 522                        /* skip non-userspace conntrack helpers. */
 523                        if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
 524                                continue;
 525
 526                        if (helper_name && strncmp(cur->name, helper_name,
 527                                                NF_CT_HELPER_NAME_LEN) != 0) {
 528                                continue;
 529                        }
 530                        if (tuple_set &&
 531                            (tuple.src.l3num != cur->tuple.src.l3num ||
 532                             tuple.dst.protonum != cur->tuple.dst.protonum))
 533                                continue;
 534
 535                        skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 536                        if (skb2 == NULL) {
 537                                ret = -ENOMEM;
 538                                break;
 539                        }
 540
 541                        ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).pid,
 542                                                nlh->nlmsg_seq,
 543                                                NFNL_MSG_TYPE(nlh->nlmsg_type),
 544                                                NFNL_MSG_CTHELPER_NEW, cur);
 545                        if (ret <= 0) {
 546                                kfree_skb(skb2);
 547                                break;
 548                        }
 549
 550                        ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).pid,
 551                                                MSG_DONTWAIT);
 552                        if (ret > 0)
 553                                ret = 0;
 554
 555                        /* this avoids a loop in nfnetlink. */
 556                        return ret == -EAGAIN ? -ENOBUFS : ret;
 557                }
 558        }
 559        return ret;
 560}
 561
 562static int
 563nfnl_cthelper_del(struct sock *nfnl, struct sk_buff *skb,
 564             const struct nlmsghdr *nlh, const struct nlattr * const tb[])
 565{
 566        char *helper_name = NULL;
 567        struct nf_conntrack_helper *cur;
 568        struct hlist_node *n, *tmp;
 569        struct nf_conntrack_tuple tuple;
 570        bool tuple_set = false, found = false;
 571        int i, j = 0, ret;
 572
 573        if (tb[NFCTH_NAME])
 574                helper_name = nla_data(tb[NFCTH_NAME]);
 575
 576        if (tb[NFCTH_TUPLE]) {
 577                ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
 578                if (ret < 0)
 579                        return ret;
 580
 581                tuple_set = true;
 582        }
 583
 584        for (i = 0; i < nf_ct_helper_hsize; i++) {
 585                hlist_for_each_entry_safe(cur, n, tmp, &nf_ct_helper_hash[i],
 586                                                                hnode) {
 587                        /* skip non-userspace conntrack helpers. */
 588                        if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
 589                                continue;
 590
 591                        j++;
 592
 593                        if (helper_name && strncmp(cur->name, helper_name,
 594                                                NF_CT_HELPER_NAME_LEN) != 0) {
 595                                continue;
 596                        }
 597                        if (tuple_set &&
 598                            (tuple.src.l3num != cur->tuple.src.l3num ||
 599                             tuple.dst.protonum != cur->tuple.dst.protonum))
 600                                continue;
 601
 602                        found = true;
 603                        nf_conntrack_helper_unregister(cur);
 604                }
 605        }
 606        /* Make sure we return success if we flush and there is no helpers */
 607        return (found || j == 0) ? 0 : -ENOENT;
 608}
 609
 610static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = {
 611        [NFCTH_NAME] = { .type = NLA_NUL_STRING,
 612                         .len = NF_CT_HELPER_NAME_LEN-1 },
 613        [NFCTH_QUEUE_NUM] = { .type = NLA_U32, },
 614};
 615
 616static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = {
 617        [NFNL_MSG_CTHELPER_NEW]         = { .call = nfnl_cthelper_new,
 618                                            .attr_count = NFCTH_MAX,
 619                                            .policy = nfnl_cthelper_policy },
 620        [NFNL_MSG_CTHELPER_GET]         = { .call = nfnl_cthelper_get,
 621                                            .attr_count = NFCTH_MAX,
 622                                            .policy = nfnl_cthelper_policy },
 623        [NFNL_MSG_CTHELPER_DEL]         = { .call = nfnl_cthelper_del,
 624                                            .attr_count = NFCTH_MAX,
 625                                            .policy = nfnl_cthelper_policy },
 626};
 627
 628static const struct nfnetlink_subsystem nfnl_cthelper_subsys = {
 629        .name                           = "cthelper",
 630        .subsys_id                      = NFNL_SUBSYS_CTHELPER,
 631        .cb_count                       = NFNL_MSG_CTHELPER_MAX,
 632        .cb                             = nfnl_cthelper_cb,
 633};
 634
 635MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER);
 636
 637static int __init nfnl_cthelper_init(void)
 638{
 639        int ret;
 640
 641        ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys);
 642        if (ret < 0) {
 643                pr_err("nfnl_cthelper: cannot register with nfnetlink.\n");
 644                goto err_out;
 645        }
 646        return 0;
 647err_out:
 648        return ret;
 649}
 650
 651static void __exit nfnl_cthelper_exit(void)
 652{
 653        struct nf_conntrack_helper *cur;
 654        struct hlist_node *n, *tmp;
 655        int i;
 656
 657        nfnetlink_subsys_unregister(&nfnl_cthelper_subsys);
 658
 659        for (i=0; i<nf_ct_helper_hsize; i++) {
 660                hlist_for_each_entry_safe(cur, n, tmp, &nf_ct_helper_hash[i],
 661                                                                        hnode) {
 662                        /* skip non-userspace conntrack helpers. */
 663                        if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
 664                                continue;
 665
 666                        nf_conntrack_helper_unregister(cur);
 667                }
 668        }
 669}
 670
 671module_init(nfnl_cthelper_init);
 672module_exit(nfnl_cthelper_exit);
 673
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