net/netfilter/nf_conntrack_netlink.c

   1 /* Connection tracking via netlink socket. Allows for user space
   2  * protocol helpers and general trouble making from userspace.
   3  *
   4  * (C) 2001 by Jay Schulist <jschlst@samba.org>
   5  * (C) 2002-2006 by Harald Welte <laforge@gnumonks.org>
   6  * (C) 2003 by Patrick Mchardy <kaber@trash.net>
   7  * (C) 2005-2006 by Pablo Neira Ayuso <pablo@eurodev.net>
   8  *
   9  * I've reworked this stuff to use attributes instead of conntrack
  10  * structures. 5.44 am. I need more tea. --pablo 05/07/11.
  11  *
  12  * Initial connection tracking via netlink development funded and
  13  * generally made possible by Network Robots, Inc. (www.networkrobots.com)
  14  *
  15  * Further development of this code funded by Astaro AG (http://www.astaro.com)
  16  *
  17  * This software may be used and distributed according to the terms
  18  * of the GNU General Public License, incorporated herein by reference.
  19  *
  20  * Derived from ip_conntrack_netlink.c: Port by Pablo Neira Ayuso (05/11/14)
  21  */
  22
  23 #include <linux/init.h>
  24 #include <linux/module.h>
  25 #include <linux/kernel.h>
  26 #include <linux/types.h>
  27 #include <linux/timer.h>
  28 #include <linux/skbuff.h>
  29 #include <linux/errno.h>
  30 #include <linux/netlink.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/notifier.h>
  34
  35 #include <linux/netfilter.h>
  36 #include <net/netfilter/nf_conntrack.h>
  37 #include <net/netfilter/nf_conntrack_core.h>
  38 #include <net/netfilter/nf_conntrack_helper.h>
  39 #include <net/netfilter/nf_conntrack_l3proto.h>
  40 #include <net/netfilter/nf_conntrack_protocol.h>
  41 #include <linux/netfilter_ipv4/ip_nat_protocol.h>
  42
  43 #include <linux/netfilter/nfnetlink.h>
  44 #include <linux/netfilter/nfnetlink_conntrack.h>
  45
  46 MODULE_LICENSE("GPL");
  47
  48 static char __initdata version[] = "0.93";
  49
  50 static inline int
  51 ctnetlink_dump_tuples_proto(struct sk_buff *skb,
  52                             const struct nf_conntrack_tuple *tuple,
  53                             struct nf_conntrack_protocol *proto)
  54 {
  55         int ret = 0;
  56         struct nfattr *nest_parms = NFA_NEST(skb, CTA_TUPLE_PROTO);
  57
  58         NFA_PUT(skb, CTA_PROTO_NUM, sizeof(u_int8_t), &tuple->dst.protonum);
  59
  60         if (likely(proto->tuple_to_nfattr))
  61                 ret = proto->tuple_to_nfattr(skb, tuple);
  62
  63         NFA_NEST_END(skb, nest_parms);
  64
  65         return ret;
  66
  67 nfattr_failure:
  68         return -1;
  69 }
  70
  71 static inline int
  72 ctnetlink_dump_tuples_ip(struct sk_buff *skb,
  73                          const struct nf_conntrack_tuple *tuple,
  74                          struct nf_conntrack_l3proto *l3proto)
  75 {
  76         int ret = 0;
  77         struct nfattr *nest_parms = NFA_NEST(skb, CTA_TUPLE_IP);
  78
  79         if (likely(l3proto->tuple_to_nfattr))
  80                 ret = l3proto->tuple_to_nfattr(skb, tuple);
  81
  82         NFA_NEST_END(skb, nest_parms);
  83
  84         return ret;
  85
  86 nfattr_failure:
  87         return -1;
  88 }
  89
  90 static inline int
  91 ctnetlink_dump_tuples(struct sk_buff *skb,
  92                       const struct nf_conntrack_tuple *tuple)
  93 {
  94         int ret;
  95         struct nf_conntrack_l3proto *l3proto;
  96         struct nf_conntrack_protocol *proto;
  97
  98         l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);
  99         ret = ctnetlink_dump_tuples_ip(skb, tuple, l3proto);
 100         nf_ct_l3proto_put(l3proto);
 101
 102         if (unlikely(ret < 0))
 103                 return ret;
 104
 105         proto = nf_ct_proto_find_get(tuple->src.l3num, tuple->dst.protonum);
 106         ret = ctnetlink_dump_tuples_proto(skb, tuple, proto);
 107         nf_ct_proto_put(proto);
 108
 109         return ret;
 110 }
 111
 112 static inline int
 113 ctnetlink_dump_status(struct sk_buff *skb, const struct nf_conn *ct)
 114 {
 115         u_int32_t status = htonl((u_int32_t) ct->status);
 116         NFA_PUT(skb, CTA_STATUS, sizeof(status), &status);
 117         return 0;
 118
 119 nfattr_failure:
 120         return -1;
 121 }
 122
 123 static inline int
 124 ctnetlink_dump_timeout(struct sk_buff *skb, const struct nf_conn *ct)
 125 {
 126         long timeout_l = ct->timeout.expires - jiffies;
 127         u_int32_t timeout;
 128
 129         if (timeout_l < 0)
 130                 timeout = 0;
 131         else
 132                 timeout = htonl(timeout_l / HZ);
 133
 134         NFA_PUT(skb, CTA_TIMEOUT, sizeof(timeout), &timeout);
 135         return 0;
 136
 137 nfattr_failure:
 138         return -1;
 139 }
 140
 141 static inline int
 142 ctnetlink_dump_protoinfo(struct sk_buff *skb, const struct nf_conn *ct)
 143 {
 144         struct nf_conntrack_protocol *proto = nf_ct_proto_find_get(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num, ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum);
 145         struct nfattr *nest_proto;
 146         int ret;
 147
 148         if (!proto->to_nfattr) {
 149                 nf_ct_proto_put(proto);
 150                 return 0;
 151         }
 152
 153         nest_proto = NFA_NEST(skb, CTA_PROTOINFO);
 154
 155         ret = proto->to_nfattr(skb, nest_proto, ct);
 156
 157         nf_ct_proto_put(proto);
 158
 159         NFA_NEST_END(skb, nest_proto);
 160
 161         return ret;
 162
 163 nfattr_failure:
 164         nf_ct_proto_put(proto);
 165         return -1;
 166 }
 167
 168 static inline int
 169 ctnetlink_dump_helpinfo(struct sk_buff *skb, const struct nf_conn *ct)
 170 {
 171         struct nfattr *nest_helper;
 172         const struct nf_conn_help *help = nfct_help(ct);
 173
 174         if (!help || !help->helper)
 175                 return 0;
 176
 177         nest_helper = NFA_NEST(skb, CTA_HELP);
 178         NFA_PUT(skb, CTA_HELP_NAME, strlen(help->helper->name), help->helper->name);
 179
 180         if (help->helper->to_nfattr)
 181                 help->helper->to_nfattr(skb, ct);
 182
 183         NFA_NEST_END(skb, nest_helper);
 184
 185         return 0;
 186
 187 nfattr_failure:
 188         return -1;
 189 }
 190
 191 #ifdef CONFIG_NF_CT_ACCT
 192 static inline int
 193 ctnetlink_dump_counters(struct sk_buff *skb, const struct nf_conn *ct,
 194                         enum ip_conntrack_dir dir)
 195 {
 196         enum ctattr_type type = dir ? CTA_COUNTERS_REPLY: CTA_COUNTERS_ORIG;
 197         struct nfattr *nest_count = NFA_NEST(skb, type);
 198         u_int32_t tmp;
 199
 200         tmp = htonl(ct->counters[dir].packets);
 201         NFA_PUT(skb, CTA_COUNTERS32_PACKETS, sizeof(u_int32_t), &tmp);
 202
 203         tmp = htonl(ct->counters[dir].bytes);
 204         NFA_PUT(skb, CTA_COUNTERS32_BYTES, sizeof(u_int32_t), &tmp);
 205
 206         NFA_NEST_END(skb, nest_count);
 207
 208         return 0;
 209
 210 nfattr_failure:
 211         return -1;
 212 }
 213 #else
 214 #define ctnetlink_dump_counters(a, b, c) (0)
 215 #endif
 216
 217 #ifdef CONFIG_NF_CONNTRACK_MARK
 218 static inline int
 219 ctnetlink_dump_mark(struct sk_buff *skb, const struct nf_conn *ct)
 220 {
 221         u_int32_t mark = htonl(ct->mark);
 222
 223         NFA_PUT(skb, CTA_MARK, sizeof(u_int32_t), &mark);
 224         return 0;
 225
 226 nfattr_failure:
 227         return -1;
 228 }
 229 #else
 230 #define ctnetlink_dump_mark(a, b) (0)
 231 #endif
 232
 233 static inline int
 234 ctnetlink_dump_id(struct sk_buff *skb, const struct nf_conn *ct)
 235 {
 236         u_int32_t id = htonl(ct->id);
 237         NFA_PUT(skb, CTA_ID, sizeof(u_int32_t), &id);
 238         return 0;
 239
 240 nfattr_failure:
 241         return -1;
 242 }
 243
 244 static inline int
 245 ctnetlink_dump_use(struct sk_buff *skb, const struct nf_conn *ct)
 246 {
 247         u_int32_t use = htonl(atomic_read(&ct->ct_general.use));
 248
 249         NFA_PUT(skb, CTA_USE, sizeof(u_int32_t), &use);
 250         return 0;
 251
 252 nfattr_failure:
 253         return -1;
 254 }
 255
 256 #define tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
 257
 258 static int
 259 ctnetlink_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
 260                     int event, int nowait,
 261                     const struct nf_conn *ct)
 262 {
 263         struct nlmsghdr *nlh;
 264         struct nfgenmsg *nfmsg;
 265         struct nfattr *nest_parms;
 266         unsigned char *b;
 267
 268         b = skb->tail;
 269
 270         event |= NFNL_SUBSYS_CTNETLINK << 8;
 271         nlh    = NLMSG_PUT(skb, pid, seq, event, sizeof(struct nfgenmsg));
 272         nfmsg  = NLMSG_DATA(nlh);
 273
 274         nlh->nlmsg_flags    = (nowait && pid) ? NLM_F_MULTI : 0;
 275         nfmsg->nfgen_family =
 276                 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 277         nfmsg->version      = NFNETLINK_V0;
 278         nfmsg->res_id       = 0;
 279
 280         nest_parms = NFA_NEST(skb, CTA_TUPLE_ORIG);
 281         if (ctnetlink_dump_tuples(skb, tuple(ct, IP_CT_DIR_ORIGINAL)) < 0)
 282                 goto nfattr_failure;
 283         NFA_NEST_END(skb, nest_parms);
 284
 285         nest_parms = NFA_NEST(skb, CTA_TUPLE_REPLY);
 286         if (ctnetlink_dump_tuples(skb, tuple(ct, IP_CT_DIR_REPLY)) < 0)
 287                 goto nfattr_failure;
 288         NFA_NEST_END(skb, nest_parms);
 289
 290         if (ctnetlink_dump_status(skb, ct) < 0 ||
 291             ctnetlink_dump_timeout(skb, ct) < 0 ||
 292             ctnetlink_dump_counters(skb, ct, IP_CT_DIR_ORIGINAL) < 0 ||
 293             ctnetlink_dump_counters(skb, ct, IP_CT_DIR_REPLY) < 0 ||
 294             ctnetlink_dump_protoinfo(skb, ct) < 0 ||
 295             ctnetlink_dump_helpinfo(skb, ct) < 0 ||
 296             ctnetlink_dump_mark(skb, ct) < 0 ||
 297             ctnetlink_dump_id(skb, ct) < 0 ||
 298             ctnetlink_dump_use(skb, ct) < 0)
 299                 goto nfattr_failure;
 300
 301         nlh->nlmsg_len = skb->tail - b;
 302         return skb->len;
 303
 304 nlmsg_failure:
 305 nfattr_failure:
 306         skb_trim(skb, b - skb->data);
 307         return -1;
 308 }
 309
 310 #ifdef CONFIG_NF_CONNTRACK_EVENTS
 311 static int ctnetlink_conntrack_event(struct notifier_block *this,
 312                                      unsigned long events, void *ptr)
 313 {
 314         struct nlmsghdr *nlh;
 315         struct nfgenmsg *nfmsg;
 316         struct nfattr *nest_parms;
 317         struct nf_conn *ct = (struct nf_conn *)ptr;
 318         struct sk_buff *skb;
 319         unsigned int type;
 320         unsigned char *b;
 321         unsigned int flags = 0, group;
 322
 323         /* ignore our fake conntrack entry */
 324         if (ct == &nf_conntrack_untracked)
 325                 return NOTIFY_DONE;
 326
 327         if (events & IPCT_DESTROY) {
 328                 type = IPCTNL_MSG_CT_DELETE;
 329                 group = NFNLGRP_CONNTRACK_DESTROY;
 330         } else  if (events & (IPCT_NEW | IPCT_RELATED)) {
 331                 type = IPCTNL_MSG_CT_NEW;
 332                 flags = NLM_F_CREATE|NLM_F_EXCL;
 333                 /* dump everything */
 334                 events = ~0UL;
 335                 group = NFNLGRP_CONNTRACK_NEW;
 336         } else  if (events & (IPCT_STATUS | IPCT_PROTOINFO)) {
 337                 type = IPCTNL_MSG_CT_NEW;
 338                 group = NFNLGRP_CONNTRACK_UPDATE;
 339         } else
 340                 return NOTIFY_DONE;
 341
 342         if (!nfnetlink_has_listeners(group))
 343                 return NOTIFY_DONE;
 344
 345         skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
 346         if (!skb)
 347                 return NOTIFY_DONE;
 348
 349         b = skb->tail;
 350
 351         type |= NFNL_SUBSYS_CTNETLINK << 8;
 352         nlh   = NLMSG_PUT(skb, 0, 0, type, sizeof(struct nfgenmsg));
 353         nfmsg = NLMSG_DATA(nlh);
 354
 355         nlh->nlmsg_flags    = flags;
 356         nfmsg->nfgen_family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 357         nfmsg->version  = NFNETLINK_V0;
 358         nfmsg->res_id   = 0;
 359
 360         nest_parms = NFA_NEST(skb, CTA_TUPLE_ORIG);
 361         if (ctnetlink_dump_tuples(skb, tuple(ct, IP_CT_DIR_ORIGINAL)) < 0)
 362                 goto nfattr_failure;
 363         NFA_NEST_END(skb, nest_parms);
 364
 365         nest_parms = NFA_NEST(skb, CTA_TUPLE_REPLY);
 366         if (ctnetlink_dump_tuples(skb, tuple(ct, IP_CT_DIR_REPLY)) < 0)
 367                 goto nfattr_failure;
 368         NFA_NEST_END(skb, nest_parms);
 369
 370         /* NAT stuff is now a status flag */
 371         if ((events & IPCT_STATUS || events & IPCT_NATINFO)
 372             && ctnetlink_dump_status(skb, ct) < 0)
 373                 goto nfattr_failure;
 374         if (events & IPCT_REFRESH
 375             && ctnetlink_dump_timeout(skb, ct) < 0)
 376                 goto nfattr_failure;
 377         if (events & IPCT_PROTOINFO
 378             && ctnetlink_dump_protoinfo(skb, ct) < 0)
 379                 goto nfattr_failure;
 380         if (events & IPCT_HELPINFO
 381             && ctnetlink_dump_helpinfo(skb, ct) < 0)
 382                 goto nfattr_failure;
 383
 384         if (ctnetlink_dump_counters(skb, ct, IP_CT_DIR_ORIGINAL) < 0 ||
 385             ctnetlink_dump_counters(skb, ct, IP_CT_DIR_REPLY) < 0)
 386                 goto nfattr_failure;
 387
 388         if (events & IPCT_MARK
 389             && ctnetlink_dump_mark(skb, ct) < 0)
 390                 goto nfattr_failure;
 391
 392         nlh->nlmsg_len = skb->tail - b;
 393         nfnetlink_send(skb, 0, group, 0);
 394         return NOTIFY_DONE;
 395
 396 nlmsg_failure:
 397 nfattr_failure:
 398         kfree_skb(skb);
 399         return NOTIFY_DONE;
 400 }
 401 #endif /* CONFIG_NF_CONNTRACK_EVENTS */
 402
 403 static int ctnetlink_done(struct netlink_callback *cb)
 404 {
 405         if (cb->args[1])
 406                 nf_ct_put((struct nf_conn *)cb->args[1]);
 407         return 0;
 408 }
 409
 410 #define L3PROTO(ct) ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num
 411
 412 static int
 413 ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
 414 {
 415         struct nf_conn *ct, *last;
 416         struct nf_conntrack_tuple_hash *h;
 417         struct list_head *i;
 418         struct nfgenmsg *nfmsg = NLMSG_DATA(cb->nlh);
 419         u_int8_t l3proto = nfmsg->nfgen_family;
 420
 421         read_lock_bh(&nf_conntrack_lock);
 422         last = (struct nf_conn *)cb->args[1];
 423         for (; cb->args[0] < nf_conntrack_htable_size; cb->args[0]++) {
 424 restart:
 425                 list_for_each_prev(i, &nf_conntrack_hash[cb->args[0]]) {
 426                         h = (struct nf_conntrack_tuple_hash *) i;
 427                         if (DIRECTION(h) != IP_CT_DIR_ORIGINAL)
 428                                 continue;
 429                         ct = nf_ct_tuplehash_to_ctrack(h);
 430                         /* Dump entries of a given L3 protocol number.
 431                          * If it is not specified, ie. l3proto == 0,
 432                          * then dump everything. */
 433                         if (l3proto && L3PROTO(ct) != l3proto)
 434                                 continue;
 435                         if (cb->args[1]) {
 436                                 if (ct != last)
 437                                         continue;
 438                                 cb->args[1] = 0;
 439                         }
 440                         if (ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).pid,
 441                                                 cb->nlh->nlmsg_seq,
 442                                                 IPCTNL_MSG_CT_NEW,
 443                                                 1, ct) < 0) {
 444                                 nf_conntrack_get(&ct->ct_general);
 445                                 cb->args[1] = (unsigned long)ct;
 446                                 goto out;
 447                         }
 448 #ifdef CONFIG_NF_CT_ACCT
 449                         if (NFNL_MSG_TYPE(cb->nlh->nlmsg_type) ==
 450                                                 IPCTNL_MSG_CT_GET_CTRZERO)
 451                                 memset(&ct->counters, 0, sizeof(ct->counters));
 452 #endif
 453                 }
 454                 if (cb->args[1]) {
 455                         cb->args[1] = 0;
 456                         goto restart;
 457                 }
 458         }
 459 out:
 460         read_unlock_bh(&nf_conntrack_lock);
 461         if (last)
 462                 nf_ct_put(last);
 463
 464         return skb->len;
 465 }
 466
 467 static inline int
 468 ctnetlink_parse_tuple_ip(struct nfattr *attr, struct nf_conntrack_tuple *tuple)
 469 {
 470         struct nfattr *tb[CTA_IP_MAX];
 471         struct nf_conntrack_l3proto *l3proto;
 472         int ret = 0;
 473
 474         nfattr_parse_nested(tb, CTA_IP_MAX, attr);
 475
 476         l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);
 477
 478         if (likely(l3proto->nfattr_to_tuple))
 479                 ret = l3proto->nfattr_to_tuple(tb, tuple);
 480
 481         nf_ct_l3proto_put(l3proto);
 482
 483         return ret;
 484 }
 485
 486 static const size_t cta_min_proto[CTA_PROTO_MAX] = {
 487         [CTA_PROTO_NUM-1]       = sizeof(u_int8_t),
 488 };
 489
 490 static inline int
 491 ctnetlink_parse_tuple_proto(struct nfattr *attr,
 492                             struct nf_conntrack_tuple *tuple)
 493 {
 494         struct nfattr *tb[CTA_PROTO_MAX];
 495         struct nf_conntrack_protocol *proto;
 496         int ret = 0;
 497
 498         nfattr_parse_nested(tb, CTA_PROTO_MAX, attr);
 499
 500         if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto))
 501                 return -EINVAL;
 502
 503         if (!tb[CTA_PROTO_NUM-1])
 504                 return -EINVAL;
 505         tuple->dst.protonum = *(u_int8_t *)NFA_DATA(tb[CTA_PROTO_NUM-1]);
 506
 507         proto = nf_ct_proto_find_get(tuple->src.l3num, tuple->dst.protonum);
 508
 509         if (likely(proto->nfattr_to_tuple))
 510                 ret = proto->nfattr_to_tuple(tb, tuple);
 511
 512         nf_ct_proto_put(proto);
 513
 514         return ret;
 515 }
 516
 517 static inline int
 518 ctnetlink_parse_tuple(struct nfattr *cda[], struct nf_conntrack_tuple *tuple,
 519                       enum ctattr_tuple type, u_int8_t l3num)
 520 {
 521         struct nfattr *tb[CTA_TUPLE_MAX];
 522         int err;
 523
 524         memset(tuple, 0, sizeof(*tuple));
 525
 526         nfattr_parse_nested(tb, CTA_TUPLE_MAX, cda[type-1]);
 527
 528         if (!tb[CTA_TUPLE_IP-1])
 529                 return -EINVAL;
 530
 531         tuple->src.l3num = l3num;
 532
 533         err = ctnetlink_parse_tuple_ip(tb[CTA_TUPLE_IP-1], tuple);
 534         if (err < 0)
 535                 return err;
 536
 537         if (!tb[CTA_TUPLE_PROTO-1])
 538                 return -EINVAL;
 539
 540         err = ctnetlink_parse_tuple_proto(tb[CTA_TUPLE_PROTO-1], tuple);
 541         if (err < 0)
 542                 return err;
 543
 544         /* orig and expect tuples get DIR_ORIGINAL */
 545         if (type == CTA_TUPLE_REPLY)
 546                 tuple->dst.dir = IP_CT_DIR_REPLY;
 547         else
 548                 tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 549
 550         return 0;
 551 }
 552
 553 #ifdef CONFIG_IP_NF_NAT_NEEDED
 554 static const size_t cta_min_protonat[CTA_PROTONAT_MAX] = {
 555         [CTA_PROTONAT_PORT_MIN-1]       = sizeof(u_int16_t),
 556         [CTA_PROTONAT_PORT_MAX-1]       = sizeof(u_int16_t),
 557 };
 558
 559 static int ctnetlink_parse_nat_proto(struct nfattr *attr,
 560                                      const struct nf_conn *ct,
 561                                      struct ip_nat_range *range)
 562 {
 563         struct nfattr *tb[CTA_PROTONAT_MAX];
 564         struct ip_nat_protocol *npt;
 565
 566         nfattr_parse_nested(tb, CTA_PROTONAT_MAX, attr);
 567
 568         if (nfattr_bad_size(tb, CTA_PROTONAT_MAX, cta_min_protonat))
 569                 return -EINVAL;
 570
 571         npt = ip_nat_proto_find_get(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum);
 572
 573         if (!npt->nfattr_to_range) {
 574                 ip_nat_proto_put(npt);
 575                 return 0;
 576         }
 577
 578         /* nfattr_to_range returns 1 if it parsed, 0 if not, neg. on error */
 579         if (npt->nfattr_to_range(tb, range) > 0)
 580                 range->flags |= IP_NAT_RANGE_PROTO_SPECIFIED;
 581
 582         ip_nat_proto_put(npt);
 583
 584         return 0;
 585 }
 586
 587 static const size_t cta_min_nat[CTA_NAT_MAX] = {
 588         [CTA_NAT_MINIP-1]       = sizeof(u_int32_t),
 589         [CTA_NAT_MAXIP-1]       = sizeof(u_int32_t),
 590 };
 591
 592 static inline int
 593 ctnetlink_parse_nat(struct nfattr *nat,
 594                     const struct nf_conn *ct, struct ip_nat_range *range)
 595 {
 596         struct nfattr *tb[CTA_NAT_MAX];
 597         int err;
 598
 599         memset(range, 0, sizeof(*range));
 600
 601         nfattr_parse_nested(tb, CTA_NAT_MAX, nat);
 602
 603         if (nfattr_bad_size(tb, CTA_NAT_MAX, cta_min_nat))
 604                 return -EINVAL;
 605
 606         if (tb[CTA_NAT_MINIP-1])
 607                 range->min_ip = *(u_int32_t *)NFA_DATA(tb[CTA_NAT_MINIP-1]);
 608
 609         if (!tb[CTA_NAT_MAXIP-1])
 610                 range->max_ip = range->min_ip;
 611         else
 612                 range->max_ip = *(u_int32_t *)NFA_DATA(tb[CTA_NAT_MAXIP-1]);
 613
 614         if (range->min_ip)
 615                 range->flags |= IP_NAT_RANGE_MAP_IPS;
 616
 617         if (!tb[CTA_NAT_PROTO-1])
 618                 return 0;
 619
 620         err = ctnetlink_parse_nat_proto(tb[CTA_NAT_PROTO-1], ct, range);
 621         if (err < 0)
 622                 return err;
 623
 624         return 0;
 625 }
 626 #endif
 627
 628 static inline int
 629 ctnetlink_parse_help(struct nfattr *attr, char **helper_name)
 630 {
 631         struct nfattr *tb[CTA_HELP_MAX];
 632
 633         nfattr_parse_nested(tb, CTA_HELP_MAX, attr);
 634
 635         if (!tb[CTA_HELP_NAME-1])
 636                 return -EINVAL;
 637
 638         *helper_name = NFA_DATA(tb[CTA_HELP_NAME-1]);
 639
 640         return 0;
 641 }
 642
 643 static const size_t cta_min[CTA_MAX] = {
 644         [CTA_STATUS-1]          = sizeof(u_int32_t),
 645         [CTA_TIMEOUT-1]         = sizeof(u_int32_t),
 646         [CTA_MARK-1]            = sizeof(u_int32_t),
 647         [CTA_USE-1]             = sizeof(u_int32_t),
 648         [CTA_ID-1]              = sizeof(u_int32_t)
 649 };
 650
 651 static int
 652 ctnetlink_del_conntrack(struct sock *ctnl, struct sk_buff *skb,
 653                         struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
 654 {
 655         struct nf_conntrack_tuple_hash *h;
 656         struct nf_conntrack_tuple tuple;
 657         struct nf_conn *ct;
 658         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 659         u_int8_t u3 = nfmsg->nfgen_family;
 660         int err = 0;
 661
 662         if (nfattr_bad_size(cda, CTA_MAX, cta_min))
 663                 return -EINVAL;
 664
 665         if (cda[CTA_TUPLE_ORIG-1])
 666                 err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_ORIG, u3);
 667         else if (cda[CTA_TUPLE_REPLY-1])
 668                 err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_REPLY, u3);
 669         else {
 670                 /* Flush the whole table */
 671                 nf_conntrack_flush();
 672                 return 0;
 673         }
 674
 675         if (err < 0)
 676                 return err;
 677
 678         h = nf_conntrack_find_get(&tuple, NULL);
 679         if (!h)
 680                 return -ENOENT;
 681
 682         ct = nf_ct_tuplehash_to_ctrack(h);
 683
 684         if (cda[CTA_ID-1]) {
 685                 u_int32_t id = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_ID-1]));
 686                 if (ct->id != id) {
 687                         nf_ct_put(ct);
 688                         return -ENOENT;
 689                 }
 690         }
 691         if (del_timer(&ct->timeout))
 692                 ct->timeout.function((unsigned long)ct);
 693
 694         nf_ct_put(ct);
 695
 696         return 0;
 697 }
 698
 699 static int
 700 ctnetlink_get_conntrack(struct sock *ctnl, struct sk_buff *skb,
 701                         struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
 702 {
 703         struct nf_conntrack_tuple_hash *h;
 704         struct nf_conntrack_tuple tuple;
 705         struct nf_conn *ct;
 706         struct sk_buff *skb2 = NULL;
 707         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 708         u_int8_t u3 = nfmsg->nfgen_family;
 709         int err = 0;
 710
 711         if (nlh->nlmsg_flags & NLM_F_DUMP) {
 712                 u32 rlen;
 713
 714 #ifndef CONFIG_NF_CT_ACCT
 715                 if (NFNL_MSG_TYPE(nlh->nlmsg_type) == IPCTNL_MSG_CT_GET_CTRZERO)
 716                         return -ENOTSUPP;
 717 #endif
 718                 if ((*errp = netlink_dump_start(ctnl, skb, nlh,
 719                                                 ctnetlink_dump_table,
 720                                                 ctnetlink_done)) != 0)
 721                         return -EINVAL;
 722
 723                 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
 724                 if (rlen > skb->len)
 725                         rlen = skb->len;
 726                 skb_pull(skb, rlen);
 727                 return 0;
 728         }
 729
 730         if (nfattr_bad_size(cda, CTA_MAX, cta_min))
 731                 return -EINVAL;
 732
 733         if (cda[CTA_TUPLE_ORIG-1])
 734                 err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_ORIG, u3);
 735         else if (cda[CTA_TUPLE_REPLY-1])
 736                 err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_REPLY, u3);
 737         else
 738                 return -EINVAL;
 739
 740         if (err < 0)
 741                 return err;
 742
 743         h = nf_conntrack_find_get(&tuple, NULL);
 744         if (!h)
 745                 return -ENOENT;
 746
 747         ct = nf_ct_tuplehash_to_ctrack(h);
 748
 749         err = -ENOMEM;
 750         skb2 = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 751         if (!skb2) {
 752                 nf_ct_put(ct);
 753                 return -ENOMEM;
 754         }
 755         NETLINK_CB(skb2).dst_pid = NETLINK_CB(skb).pid;
 756
 757         err = ctnetlink_fill_info(skb2, NETLINK_CB(skb).pid, nlh->nlmsg_seq,
 758                                   IPCTNL_MSG_CT_NEW, 1, ct);
 759         nf_ct_put(ct);
 760         if (err <= 0)
 761                 goto free;
 762
 763         err = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).pid, MSG_DONTWAIT);
 764         if (err < 0)
 765                 goto out;
 766
 767         return 0;
 768
 769 free:
 770         kfree_skb(skb2);
 771 out:
 772         return err;
 773 }
 774
 775 static inline int
 776 ctnetlink_change_status(struct nf_conn *ct, struct nfattr *cda[])
 777 {
 778         unsigned long d;
 779         unsigned status = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_STATUS-1]));
 780         d = ct->status ^ status;
 781
 782         if (d & (IPS_EXPECTED|IPS_CONFIRMED|IPS_DYING))
 783                 /* unchangeable */
 784                 return -EINVAL;
 785
 786         if (d & IPS_SEEN_REPLY && !(status & IPS_SEEN_REPLY))
 787                 /* SEEN_REPLY bit can only be set */
 788                 return -EINVAL;
 789
 790
 791         if (d & IPS_ASSURED && !(status & IPS_ASSURED))
 792                 /* ASSURED bit can only be set */
 793                 return -EINVAL;
 794
 795         if (cda[CTA_NAT_SRC-1] || cda[CTA_NAT_DST-1]) {
 796 #ifndef CONFIG_IP_NF_NAT_NEEDED
 797                 return -EINVAL;
 798 #else
 799                 struct ip_nat_range range;
 800
 801                 if (cda[CTA_NAT_DST-1]) {
 802                         if (ctnetlink_parse_nat(cda[CTA_NAT_DST-1], ct,
 803                                                 &range) < 0)
 804                                 return -EINVAL;
 805                         if (ip_nat_initialized(ct,
 806                                                HOOK2MANIP(NF_IP_PRE_ROUTING)))
 807                                 return -EEXIST;
 808                         ip_nat_setup_info(ct, &range, hooknum);
 809                 }
 810                 if (cda[CTA_NAT_SRC-1]) {
 811                         if (ctnetlink_parse_nat(cda[CTA_NAT_SRC-1], ct,
 812                                                 &range) < 0)
 813                                 return -EINVAL;
 814                         if (ip_nat_initialized(ct,
 815                                                HOOK2MANIP(NF_IP_POST_ROUTING)))
 816                                 return -EEXIST;
 817                         ip_nat_setup_info(ct, &range, hooknum);
 818                 }
 819 #endif
 820         }
 821
 822         /* Be careful here, modifying NAT bits can screw up things,
 823          * so don't let users modify them directly if they don't pass
 824          * ip_nat_range. */
 825         ct->status |= status & ~(IPS_NAT_DONE_MASK | IPS_NAT_MASK);
 826         return 0;
 827 }
 828
 829
 830 static inline int
 831 ctnetlink_change_helper(struct nf_conn *ct, struct nfattr *cda[])
 832 {
 833         struct nf_conntrack_helper *helper;
 834         struct nf_conn_help *help = nfct_help(ct);
 835         char *helpname;
 836         int err;
 837
 838         if (!help) {
 839                 /* FIXME: we need to reallocate and rehash */
 840                 return -EBUSY;
 841         }
 842
 843         /* don't change helper of sibling connections */
 844         if (ct->master)
 845                 return -EINVAL;
 846
 847         err = ctnetlink_parse_help(cda[CTA_HELP-1], &helpname);
 848         if (err < 0)
 849                 return err;
 850
 851         helper = __nf_conntrack_helper_find_byname(helpname);
 852         if (!helper) {
 853                 if (!strcmp(helpname, ""))
 854                         helper = NULL;
 855                 else
 856                         return -EINVAL;
 857         }
 858
 859         if (help->helper) {
 860                 if (!helper) {
 861                         /* we had a helper before ... */
 862                         nf_ct_remove_expectations(ct);
 863                         help->helper = NULL;
 864                 } else {
 865                         /* need to zero data of old helper */
 866                         memset(&help->help, 0, sizeof(help->help));
 867                 }
 868         }
 869
 870         help->helper = helper;
 871
 872         return 0;
 873 }
 874
 875 static inline int
 876 ctnetlink_change_timeout(struct nf_conn *ct, struct nfattr *cda[])
 877 {
 878         u_int32_t timeout = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_TIMEOUT-1]));
 879
 880         if (!del_timer(&ct->timeout))
 881                 return -ETIME;
 882
 883         ct->timeout.expires = jiffies + timeout * HZ;
 884         add_timer(&ct->timeout);
 885
 886         return 0;
 887 }
 888
 889 static inline int
 890 ctnetlink_change_protoinfo(struct nf_conn *ct, struct nfattr *cda[])
 891 {
 892         struct nfattr *tb[CTA_PROTOINFO_MAX], *attr = cda[CTA_PROTOINFO-1];
 893         struct nf_conntrack_protocol *proto;
 894         u_int16_t npt = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
 895         u_int16_t l3num = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 896         int err = 0;
 897
 898         nfattr_parse_nested(tb, CTA_PROTOINFO_MAX, attr);
 899
 900         proto = nf_ct_proto_find_get(l3num, npt);
 901
 902         if (proto->from_nfattr)
 903                 err = proto->from_nfattr(tb, ct);
 904         nf_ct_proto_put(proto);
 905
 906         return err;
 907 }
 908
 909 static int
 910 ctnetlink_change_conntrack(struct nf_conn *ct, struct nfattr *cda[])
 911 {
 912         int err;
 913
 914         if (cda[CTA_HELP-1]) {
 915                 err = ctnetlink_change_helper(ct, cda);
 916                 if (err < 0)
 917                         return err;
 918         }
 919
 920         if (cda[CTA_TIMEOUT-1]) {
 921                 err = ctnetlink_change_timeout(ct, cda);
 922                 if (err < 0)
 923                         return err;
 924         }
 925
 926         if (cda[CTA_STATUS-1]) {
 927                 err = ctnetlink_change_status(ct, cda);
 928                 if (err < 0)
 929                         return err;
 930         }
 931
 932         if (cda[CTA_PROTOINFO-1]) {
 933                 err = ctnetlink_change_protoinfo(ct, cda);
 934                 if (err < 0)
 935                         return err;
 936         }
 937
 938 #if defined(CONFIG_NF_CONNTRACK_MARK)
 939         if (cda[CTA_MARK-1])
 940                 ct->mark = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_MARK-1]));
 941 #endif
 942
 943         return 0;
 944 }
 945
 946 static int
 947 ctnetlink_create_conntrack(struct nfattr *cda[],
 948                            struct nf_conntrack_tuple *otuple,
 949                            struct nf_conntrack_tuple *rtuple)
 950 {
 951         struct nf_conn *ct;
 952         int err = -EINVAL;
 953         struct nf_conn_help *help;
 954
 955         ct = nf_conntrack_alloc(otuple, rtuple);
 956         if (ct == NULL || IS_ERR(ct))
 957                 return -ENOMEM;
 958
 959         if (!cda[CTA_TIMEOUT-1])
 960                 goto err;
 961         ct->timeout.expires = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_TIMEOUT-1]));
 962
 963         ct->timeout.expires = jiffies + ct->timeout.expires * HZ;
 964         ct->status |= IPS_CONFIRMED;
 965
 966         err = ctnetlink_change_status(ct, cda);
 967         if (err < 0)
 968                 goto err;
 969
 970         if (cda[CTA_PROTOINFO-1]) {
 971                 err = ctnetlink_change_protoinfo(ct, cda);
 972                 if (err < 0)
 973                         return err;
 974         }
 975
 976 #if defined(CONFIG_NF_CONNTRACK_MARK)
 977         if (cda[CTA_MARK-1])
 978                 ct->mark = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_MARK-1]));
 979 #endif
 980
 981         help = nfct_help(ct);
 982         if (help)
 983                 help->helper = nf_ct_helper_find_get(rtuple);
 984
 985         add_timer(&ct->timeout);
 986         nf_conntrack_hash_insert(ct);
 987
 988         if (help && help->helper)
 989                 nf_ct_helper_put(help->helper);
 990
 991         return 0;
 992
 993 err:
 994         nf_conntrack_free(ct);
 995         return err;
 996 }
 997
 998 static int
 999 ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
1000                         struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
1001 {
1002         struct nf_conntrack_tuple otuple, rtuple;
1003         struct nf_conntrack_tuple_hash *h = NULL;
1004         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
1005         u_int8_t u3 = nfmsg->nfgen_family;
1006         int err = 0;
1007
1008         if (nfattr_bad_size(cda, CTA_MAX, cta_min))
1009                 return -EINVAL;
1010
1011         if (cda[CTA_TUPLE_ORIG-1]) {
1012                 err = ctnetlink_parse_tuple(cda, &otuple, CTA_TUPLE_ORIG, u3);
1013                 if (err < 0)
1014                         return err;
1015         }
1016
1017         if (cda[CTA_TUPLE_REPLY-1]) {
1018                 err = ctnetlink_parse_tuple(cda, &rtuple, CTA_TUPLE_REPLY, u3);
1019                 if (err < 0)
1020                         return err;
1021         }
1022
1023         write_lock_bh(&nf_conntrack_lock);
1024         if (cda[CTA_TUPLE_ORIG-1])
1025                 h = __nf_conntrack_find(&otuple, NULL);
1026         else if (cda[CTA_TUPLE_REPLY-1])
1027                 h = __nf_conntrack_find(&rtuple, NULL);
1028
1029         if (h == NULL) {
1030                 write_unlock_bh(&nf_conntrack_lock);
1031                 err = -ENOENT;
1032                 if (nlh->nlmsg_flags & NLM_F_CREATE)
1033                         err = ctnetlink_create_conntrack(cda, &otuple, &rtuple);
1034                 return err;
1035         }
1036         /* implicit 'else' */
1037
1038         /* we only allow nat config for new conntracks */
1039         if (cda[CTA_NAT_SRC-1] || cda[CTA_NAT_DST-1]) {
1040                 err = -EINVAL;
1041                 goto out_unlock;
1042         }
1043
1044         /* We manipulate the conntrack inside the global conntrack table lock,
1045          * so there's no need to increase the refcount */
1046         err = -EEXIST;
1047         if (!(nlh->nlmsg_flags & NLM_F_EXCL))
1048                 err = ctnetlink_change_conntrack(nf_ct_tuplehash_to_ctrack(h), cda);
1049
1050 out_unlock:
1051         write_unlock_bh(&nf_conntrack_lock);
1052         return err;
1053 }
1054
1055 /***********************************************************************
1056  * EXPECT
1057  ***********************************************************************/
1058
1059 static inline int
1060 ctnetlink_exp_dump_tuple(struct sk_buff *skb,
1061                          const struct nf_conntrack_tuple *tuple,
1062                          enum ctattr_expect type)
1063 {
1064         struct nfattr *nest_parms = NFA_NEST(skb, type);
1065
1066         if (ctnetlink_dump_tuples(skb, tuple) < 0)
1067                 goto nfattr_failure;
1068
1069         NFA_NEST_END(skb, nest_parms);
1070
1071         return 0;
1072
1073 nfattr_failure:
1074         return -1;
1075 }
1076
1077 static inline int
1078 ctnetlink_exp_dump_mask(struct sk_buff *skb,
1079                         const struct nf_conntrack_tuple *tuple,
1080                         const struct nf_conntrack_tuple *mask)
1081 {
1082         int ret;
1083         struct nf_conntrack_l3proto *l3proto;
1084         struct nf_conntrack_protocol *proto;
1085         struct nfattr *nest_parms = NFA_NEST(skb, CTA_EXPECT_MASK);
1086
1087         l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);
1088         ret = ctnetlink_dump_tuples_ip(skb, mask, l3proto);
1089         nf_ct_l3proto_put(l3proto);
1090
1091         if (unlikely(ret < 0))
1092                 goto nfattr_failure;
1093
1094         proto = nf_ct_proto_find_get(tuple->src.l3num, tuple->dst.protonum);
1095         ret = ctnetlink_dump_tuples_proto(skb, mask, proto);
1096         nf_ct_proto_put(proto);
1097         if (unlikely(ret < 0))
1098                 goto nfattr_failure;
1099
1100         NFA_NEST_END(skb, nest_parms);
1101
1102         return 0;
1103
1104 nfattr_failure:
1105         return -1;
1106 }
1107
1108 static inline int
1109 ctnetlink_exp_dump_expect(struct sk_buff *skb,
1110                           const struct nf_conntrack_expect *exp)
1111 {
1112         struct nf_conn *master = exp->master;
1113         u_int32_t timeout = htonl((exp->timeout.expires - jiffies) / HZ);
1114         u_int32_t id = htonl(exp->id);
1115
1116         if (ctnetlink_exp_dump_tuple(skb, &exp->tuple, CTA_EXPECT_TUPLE) < 0)
1117                 goto nfattr_failure;
1118         if (ctnetlink_exp_dump_mask(skb, &exp->tuple, &exp->mask) < 0)
1119                 goto nfattr_failure;
1120         if (ctnetlink_exp_dump_tuple(skb,
1121                                  &master->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
1122                                  CTA_EXPECT_MASTER) < 0)
1123                 goto nfattr_failure;
1124
1125         NFA_PUT(skb, CTA_EXPECT_TIMEOUT, sizeof(timeout), &timeout);
1126         NFA_PUT(skb, CTA_EXPECT_ID, sizeof(u_int32_t), &id);
1127
1128         return 0;
1129
1130 nfattr_failure:
1131         return -1;
1132 }
1133
1134 static int
1135 ctnetlink_exp_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
1136                     int event,
1137                     int nowait,
1138                     const struct nf_conntrack_expect *exp)
1139 {
1140         struct nlmsghdr *nlh;
1141         struct nfgenmsg *nfmsg;
1142         unsigned char *b;
1143
1144         b = skb->tail;
1145
1146         event |= NFNL_SUBSYS_CTNETLINK_EXP << 8;
1147         nlh    = NLMSG_PUT(skb, pid, seq, event, sizeof(struct nfgenmsg));
1148         nfmsg  = NLMSG_DATA(nlh);
1149
1150         nlh->nlmsg_flags    = (nowait && pid) ? NLM_F_MULTI : 0;
1151         nfmsg->nfgen_family = exp->tuple.src.l3num;
1152         nfmsg->version      = NFNETLINK_V0;
1153         nfmsg->res_id       = 0;
1154
1155         if (ctnetlink_exp_dump_expect(skb, exp) < 0)
1156                 goto nfattr_failure;
1157
1158         nlh->nlmsg_len = skb->tail - b;
1159         return skb->len;
1160
1161 nlmsg_failure:
1162 nfattr_failure:
1163         skb_trim(skb, b - skb->data);
1164         return -1;
1165 }
1166
1167 #ifdef CONFIG_NF_CONNTRACK_EVENTS
1168 static int ctnetlink_expect_event(struct notifier_block *this,
1169                                   unsigned long events, void *ptr)
1170 {
1171         struct nlmsghdr *nlh;
1172         struct nfgenmsg *nfmsg;
1173         struct nf_conntrack_expect *exp = (struct nf_conntrack_expect *)ptr;
1174         struct sk_buff *skb;
1175         unsigned int type;
1176         unsigned char *b;
1177         int flags = 0;
1178
1179         if (events & IPEXP_NEW) {
1180                 type = IPCTNL_MSG_EXP_NEW;
1181                 flags = NLM_F_CREATE|NLM_F_EXCL;
1182         } else
1183                 return NOTIFY_DONE;
1184
1185         if (!nfnetlink_has_listeners(NFNLGRP_CONNTRACK_EXP_NEW))
1186                 return NOTIFY_DONE;
1187
1188         skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
1189         if (!skb)
1190                 return NOTIFY_DONE;
1191
1192         b = skb->tail;
1193
1194         type |= NFNL_SUBSYS_CTNETLINK_EXP << 8;
1195         nlh   = NLMSG_PUT(skb, 0, 0, type, sizeof(struct nfgenmsg));
1196         nfmsg = NLMSG_DATA(nlh);
1197
1198         nlh->nlmsg_flags    = flags;
1199         nfmsg->nfgen_family = exp->tuple.src.l3num;
1200         nfmsg->version      = NFNETLINK_V0;
1201         nfmsg->res_id       = 0;
1202
1203         if (ctnetlink_exp_dump_expect(skb, exp) < 0)
1204                 goto nfattr_failure;
1205
1206         nlh->nlmsg_len = skb->tail - b;
1207         nfnetlink_send(skb, 0, NFNLGRP_CONNTRACK_EXP_NEW, 0);
1208         return NOTIFY_DONE;
1209
1210 nlmsg_failure:
1211 nfattr_failure:
1212         kfree_skb(skb);
1213         return NOTIFY_DONE;
1214 }
1215 #endif
1216
1217 static int
1218 ctnetlink_exp_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
1219 {
1220         struct nf_conntrack_expect *exp = NULL;
1221         struct list_head *i;
1222         u_int32_t *id = (u_int32_t *) &cb->args[0];
1223         struct nfgenmsg *nfmsg = NLMSG_DATA(cb->nlh);
1224         u_int8_t l3proto = nfmsg->nfgen_family;
1225
1226         read_lock_bh(&nf_conntrack_lock);
1227         list_for_each_prev(i, &nf_conntrack_expect_list) {
1228                 exp = (struct nf_conntrack_expect *) i;
1229                 if (l3proto && exp->tuple.src.l3num != l3proto)
1230                         continue;
1231                 if (exp->id <= *id)
1232                         continue;
1233                 if (ctnetlink_exp_fill_info(skb, NETLINK_CB(cb->skb).pid,
1234                                             cb->nlh->nlmsg_seq,
1235                                             IPCTNL_MSG_EXP_NEW,
1236                                             1, exp) < 0)
1237                         goto out;
1238                 *id = exp->id;
1239         }
1240 out:
1241         read_unlock_bh(&nf_conntrack_lock);
1242
1243         return skb->len;
1244 }
1245
1246 static const size_t cta_min_exp[CTA_EXPECT_MAX] = {
1247         [CTA_EXPECT_TIMEOUT-1]          = sizeof(u_int32_t),
1248         [CTA_EXPECT_ID-1]               = sizeof(u_int32_t)
1249 };
1250
1251 static int
1252 ctnetlink_get_expect(struct sock *ctnl, struct sk_buff *skb,
1253                      struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
1254 {
1255         struct nf_conntrack_tuple tuple;
1256         struct nf_conntrack_expect *exp;
1257         struct sk_buff *skb2;
1258         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
1259         u_int8_t u3 = nfmsg->nfgen_family;
1260         int err = 0;
1261
1262         if (nfattr_bad_size(cda, CTA_EXPECT_MAX, cta_min_exp))
1263                 return -EINVAL;
1264
1265         if (nlh->nlmsg_flags & NLM_F_DUMP) {
1266                 u32 rlen;
1267
1268                 if ((*errp = netlink_dump_start(ctnl, skb, nlh,
1269                                                 ctnetlink_exp_dump_table,
1270                                                 ctnetlink_done)) != 0)
1271                         return -EINVAL;
1272                 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
1273                 if (rlen > skb->len)
1274                         rlen = skb->len;
1275                 skb_pull(skb, rlen);
1276                 return 0;
1277         }
1278
1279         if (cda[CTA_EXPECT_MASTER-1])
1280                 err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_MASTER, u3);
1281         else
1282                 return -EINVAL;
1283
1284         if (err < 0)
1285                 return err;
1286
1287         exp = nf_conntrack_expect_find(&tuple);
1288         if (!exp)
1289                 return -ENOENT;
1290
1291         if (cda[CTA_EXPECT_ID-1]) {
1292                 u_int32_t id = *(u_int32_t *)NFA_DATA(cda[CTA_EXPECT_ID-1]);
1293                 if (exp->id != ntohl(id)) {
1294                         nf_conntrack_expect_put(exp);
1295                         return -ENOENT;
1296                 }
1297         }
1298
1299         err = -ENOMEM;
1300         skb2 = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1301         if (!skb2)
1302                 goto out;
1303         NETLINK_CB(skb2).dst_pid = NETLINK_CB(skb).pid;
1304
1305         err = ctnetlink_exp_fill_info(skb2, NETLINK_CB(skb).pid,
1306                                       nlh->nlmsg_seq, IPCTNL_MSG_EXP_NEW,
1307                                       1, exp);
1308         if (err <= 0)
1309                 goto free;
1310
1311         nf_conntrack_expect_put(exp);
1312
1313         return netlink_unicast(ctnl, skb2, NETLINK_CB(skb).pid, MSG_DONTWAIT);
1314
1315 free:
1316         kfree_skb(skb2);
1317 out:
1318         nf_conntrack_expect_put(exp);
1319         return err;
1320 }
1321
1322 static int
1323 ctnetlink_del_expect(struct sock *ctnl, struct sk_buff *skb,
1324                      struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
1325 {
1326         struct nf_conntrack_expect *exp, *tmp;
1327         struct nf_conntrack_tuple tuple;
1328         struct nf_conntrack_helper *h;
1329         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
1330         u_int8_t u3 = nfmsg->nfgen_family;
1331         int err;
1332
1333         if (nfattr_bad_size(cda, CTA_EXPECT_MAX, cta_min_exp))
1334                 return -EINVAL;
1335
1336         if (cda[CTA_EXPECT_TUPLE-1]) {
1337                 /* delete a single expect by tuple */
1338                 err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE, u3);
1339                 if (err < 0)
1340                         return err;
1341
1342                 /* bump usage count to 2 */
1343                 exp = nf_conntrack_expect_find(&tuple);
1344                 if (!exp)
1345                         return -ENOENT;
1346
1347                 if (cda[CTA_EXPECT_ID-1]) {
1348                         u_int32_t id =
1349                                 *(u_int32_t *)NFA_DATA(cda[CTA_EXPECT_ID-1]);
1350                         if (exp->id != ntohl(id)) {
1351                                 nf_conntrack_expect_put(exp);
1352                                 return -ENOENT;
1353                         }
1354                 }
1355
1356                 /* after list removal, usage count == 1 */
1357                 nf_conntrack_unexpect_related(exp);
1358                 /* have to put what we 'get' above.
1359                  * after this line usage count == 0 */
1360                 nf_conntrack_expect_put(exp);
1361         } else if (cda[CTA_EXPECT_HELP_NAME-1]) {
1362                 char *name = NFA_DATA(cda[CTA_EXPECT_HELP_NAME-1]);
1363
1364                 /* delete all expectations for this helper */
1365                 write_lock_bh(&nf_conntrack_lock);
1366                 h = __nf_conntrack_helper_find_byname(name);
1367                 if (!h) {
1368                         write_unlock_bh(&nf_conntrack_lock);
1369                         return -EINVAL;
1370                 }
1371                 list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list,
1372                                          list) {
1373                         struct nf_conn_help *m_help = nfct_help(exp->master);
1374                         if (m_help->helper == h
1375                             && del_timer(&exp->timeout)) {
1376                                 nf_ct_unlink_expect(exp);
1377                                 nf_conntrack_expect_put(exp);
1378                         }
1379                 }
1380                 write_unlock_bh(&nf_conntrack_lock);
1381         } else {
1382                 /* This basically means we have to flush everything*/
1383                 write_lock_bh(&nf_conntrack_lock);
1384                 list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list,
1385                                          list) {
1386                         if (del_timer(&exp->timeout)) {
1387                                 nf_ct_unlink_expect(exp);
1388                                 nf_conntrack_expect_put(exp);
1389                         }
1390                 }
1391                 write_unlock_bh(&nf_conntrack_lock);
1392         }
1393
1394         return 0;
1395 }
1396 static int
1397 ctnetlink_change_expect(struct nf_conntrack_expect *x, struct nfattr *cda[])
1398 {
1399         return -EOPNOTSUPP;
1400 }
1401
1402 static int
1403 ctnetlink_create_expect(struct nfattr *cda[], u_int8_t u3)
1404 {
1405         struct nf_conntrack_tuple tuple, mask, master_tuple;
1406         struct nf_conntrack_tuple_hash *h = NULL;
1407         struct nf_conntrack_expect *exp;
1408         struct nf_conn *ct;
1409         struct nf_conn_help *help;
1410         int err = 0;
1411
1412         /* caller guarantees that those three CTA_EXPECT_* exist */
1413         err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE, u3);
1414         if (err < 0)
1415                 return err;
1416         err = ctnetlink_parse_tuple(cda, &mask, CTA_EXPECT_MASK, u3);
1417         if (err < 0)
1418                 return err;
1419         err = ctnetlink_parse_tuple(cda, &master_tuple, CTA_EXPECT_MASTER, u3);
1420         if (err < 0)
1421                 return err;
1422
1423         /* Look for master conntrack of this expectation */
1424         h = nf_conntrack_find_get(&master_tuple, NULL);
1425         if (!h)
1426                 return -ENOENT;
1427         ct = nf_ct_tuplehash_to_ctrack(h);
1428         help = nfct_help(ct);
1429
1430         if (!help || !help->helper) {
1431                 /* such conntrack hasn't got any helper, abort */
1432                 err = -EINVAL;
1433                 goto out;
1434         }
1435
1436         exp = nf_conntrack_expect_alloc(ct);
1437         if (!exp) {
1438                 err = -ENOMEM;
1439                 goto out;
1440         }
1441
1442         exp->expectfn = NULL;
1443         exp->flags = 0;
1444         exp->master = ct;
1445         memcpy(&exp->tuple, &tuple, sizeof(struct nf_conntrack_tuple));
1446         memcpy(&exp->mask, &mask, sizeof(struct nf_conntrack_tuple));
1447
1448         err = nf_conntrack_expect_related(exp);
1449         nf_conntrack_expect_put(exp);
1450
1451 out:
1452         nf_ct_put(nf_ct_tuplehash_to_ctrack(h));
1453         return err;
1454 }
1455
1456 static int
1457 ctnetlink_new_expect(struct sock *ctnl, struct sk_buff *skb,
1458                      struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
1459 {
1460         struct nf_conntrack_tuple tuple;
1461         struct nf_conntrack_expect *exp;
1462         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
1463         u_int8_t u3 = nfmsg->nfgen_family;
1464         int err = 0;
1465
1466         if (nfattr_bad_size(cda, CTA_EXPECT_MAX, cta_min_exp))
1467                 return -EINVAL;
1468
1469         if (!cda[CTA_EXPECT_TUPLE-1]
1470             || !cda[CTA_EXPECT_MASK-1]
1471             || !cda[CTA_EXPECT_MASTER-1])
1472                 return -EINVAL;
1473
1474         err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE, u3);
1475         if (err < 0)
1476                 return err;
1477
1478         write_lock_bh(&nf_conntrack_lock);
1479         exp = __nf_conntrack_expect_find(&tuple);
1480
1481         if (!exp) {
1482                 write_unlock_bh(&nf_conntrack_lock);
1483                 err = -ENOENT;
1484                 if (nlh->nlmsg_flags & NLM_F_CREATE)
1485                         err = ctnetlink_create_expect(cda, u3);
1486                 return err;
1487         }
1488
1489         err = -EEXIST;
1490         if (!(nlh->nlmsg_flags & NLM_F_EXCL))
1491                 err = ctnetlink_change_expect(exp, cda);
1492         write_unlock_bh(&nf_conntrack_lock);
1493
1494         return err;
1495 }
1496
1497 #ifdef CONFIG_NF_CONNTRACK_EVENTS
1498 static struct notifier_block ctnl_notifier = {
1499         .notifier_call  = ctnetlink_conntrack_event,
1500 };
1501
1502 static struct notifier_block ctnl_notifier_exp = {
1503         .notifier_call  = ctnetlink_expect_event,
1504 };
1505 #endif
1506
1507 static struct nfnl_callback ctnl_cb[IPCTNL_MSG_MAX] = {
1508         [IPCTNL_MSG_CT_NEW]             = { .call = ctnetlink_new_conntrack,
1509                                             .attr_count = CTA_MAX, },
1510         [IPCTNL_MSG_CT_GET]             = { .call = ctnetlink_get_conntrack,
1511                                             .attr_count = CTA_MAX, },
1512         [IPCTNL_MSG_CT_DELETE]          = { .call = ctnetlink_del_conntrack,
1513                                             .attr_count = CTA_MAX, },
1514         [IPCTNL_MSG_CT_GET_CTRZERO]     = { .call = ctnetlink_get_conntrack,
1515                                             .attr_count = CTA_MAX, },
1516 };
1517
1518 static struct nfnl_callback ctnl_exp_cb[IPCTNL_MSG_EXP_MAX] = {
1519         [IPCTNL_MSG_EXP_GET]            = { .call = ctnetlink_get_expect,
1520                                             .attr_count = CTA_EXPECT_MAX, },
1521         [IPCTNL_MSG_EXP_NEW]            = { .call = ctnetlink_new_expect,
1522                                             .attr_count = CTA_EXPECT_MAX, },
1523         [IPCTNL_MSG_EXP_DELETE]         = { .call = ctnetlink_del_expect,
1524                                             .attr_count = CTA_EXPECT_MAX, },
1525 };
1526
1527 static struct nfnetlink_subsystem ctnl_subsys = {
1528         .name                           = "conntrack",
1529         .subsys_id                      = NFNL_SUBSYS_CTNETLINK,
1530         .cb_count                       = IPCTNL_MSG_MAX,
1531         .cb                             = ctnl_cb,
1532 };
1533
1534 static struct nfnetlink_subsystem ctnl_exp_subsys = {
1535         .name                           = "conntrack_expect",
1536         .subsys_id                      = NFNL_SUBSYS_CTNETLINK_EXP,
1537         .cb_count                       = IPCTNL_MSG_EXP_MAX,
1538         .cb                             = ctnl_exp_cb,
1539 };
1540
1541 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK);
1542 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_EXP);
1543
1544 static int __init ctnetlink_init(void)
1545 {
1546         int ret;
1547
1548         printk("ctnetlink v%s: registering with nfnetlink.\n", version);
1549         ret = nfnetlink_subsys_register(&ctnl_subsys);
1550         if (ret < 0) {
1551                 printk("ctnetlink_init: cannot register with nfnetlink.\n");
1552                 goto err_out;
1553         }
1554
1555         ret = nfnetlink_subsys_register(&ctnl_exp_subsys);
1556         if (ret < 0) {
1557                 printk("ctnetlink_init: cannot register exp with nfnetlink.\n");
1558                 goto err_unreg_subsys;
1559         }
1560
1561 #ifdef CONFIG_NF_CONNTRACK_EVENTS
1562         ret = nf_conntrack_register_notifier(&ctnl_notifier);
1563         if (ret < 0) {
1564                 printk("ctnetlink_init: cannot register notifier.\n");
1565                 goto err_unreg_exp_subsys;
1566         }
1567
1568         ret = nf_conntrack_expect_register_notifier(&ctnl_notifier_exp);
1569         if (ret < 0) {
1570                 printk("ctnetlink_init: cannot expect register notifier.\n");
1571                 goto err_unreg_notifier;
1572         }
1573 #endif
1574
1575         return 0;
1576
1577 #ifdef CONFIG_NF_CONNTRACK_EVENTS
1578 err_unreg_notifier:
1579         nf_conntrack_unregister_notifier(&ctnl_notifier);
1580 err_unreg_exp_subsys:
1581         nfnetlink_subsys_unregister(&ctnl_exp_subsys);
1582 #endif
1583 err_unreg_subsys:
1584         nfnetlink_subsys_unregister(&ctnl_subsys);
1585 err_out:
1586         return ret;
1587 }
1588
1589 static void __exit ctnetlink_exit(void)
1590 {
1591         printk("ctnetlink: unregistering from nfnetlink.\n");
1592
1593 #ifdef CONFIG_NF_CONNTRACK_EVENTS
1594         nf_conntrack_expect_unregister_notifier(&ctnl_notifier_exp);
1595         nf_conntrack_unregister_notifier(&ctnl_notifier);
1596 #endif
1597
1598         nfnetlink_subsys_unregister(&ctnl_exp_subsys);
1599         nfnetlink_subsys_unregister(&ctnl_subsys);
1600         return;
1601 }
1602
1603 module_init(ctnetlink_init);
1604 module_exit(ctnetlink_exit);