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_expect.h>
  39 #include <net/netfilter/nf_conntrack_helper.h>
  40 #include <net/netfilter/nf_conntrack_l3proto.h>
  41 #include <net/netfilter/nf_conntrack_l4proto.h>
  42 #include <linux/netfilter_ipv4/ip_nat_protocol.h>
  43
  44 #include <linux/netfilter/nfnetlink.h>
  45 #include <linux/netfilter/nfnetlink_conntrack.h>
  46
  47 MODULE_LICENSE("GPL");
  48
  49 static char __initdata version[] = "0.93";
  50
  51 static inline int
  52 ctnetlink_dump_tuples_proto(struct sk_buff *skb,
  53                             const struct nf_conntrack_tuple *tuple,
  54                             struct nf_conntrack_l4proto *l4proto)
  55 {
  56         int ret = 0;
  57         struct nfattr *nest_parms = NFA_NEST(skb, CTA_TUPLE_PROTO);
  58
  59         NFA_PUT(skb, CTA_PROTO_NUM, sizeof(u_int8_t), &tuple->dst.protonum);
  60
  61         if (likely(l4proto->tuple_to_nfattr))
  62                 ret = l4proto->tuple_to_nfattr(skb, tuple);
  63
  64         NFA_NEST_END(skb, nest_parms);
  65
  66         return ret;
  67
  68 nfattr_failure:
  69         return -1;
  70 }
  71
  72 static inline int
  73 ctnetlink_dump_tuples_ip(struct sk_buff *skb,
  74                          const struct nf_conntrack_tuple *tuple,
  75                          struct nf_conntrack_l3proto *l3proto)
  76 {
  77         int ret = 0;
  78         struct nfattr *nest_parms = NFA_NEST(skb, CTA_TUPLE_IP);
  79
  80         if (likely(l3proto->tuple_to_nfattr))
  81                 ret = l3proto->tuple_to_nfattr(skb, tuple);
  82
  83         NFA_NEST_END(skb, nest_parms);
  84
  85         return ret;
  86
  87 nfattr_failure:
  88         return -1;
  89 }
  90
  91 static inline int
  92 ctnetlink_dump_tuples(struct sk_buff *skb,
  93                       const struct nf_conntrack_tuple *tuple)
  94 {
  95         int ret;
  96         struct nf_conntrack_l3proto *l3proto;
  97         struct nf_conntrack_l4proto *l4proto;
  98
  99         l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);
 100         ret = ctnetlink_dump_tuples_ip(skb, tuple, l3proto);
 101         nf_ct_l3proto_put(l3proto);
 102
 103         if (unlikely(ret < 0))
 104                 return ret;
 105
 106         l4proto = nf_ct_l4proto_find_get(tuple->src.l3num, tuple->dst.protonum);
 107         ret = ctnetlink_dump_tuples_proto(skb, tuple, l4proto);
 108         nf_ct_l4proto_put(l4proto);
 109
 110         return ret;
 111 }
 112
 113 static inline int
 114 ctnetlink_dump_status(struct sk_buff *skb, const struct nf_conn *ct)
 115 {
 116         u_int32_t status = htonl((u_int32_t) ct->status);
 117         NFA_PUT(skb, CTA_STATUS, sizeof(status), &status);
 118         return 0;
 119
 120 nfattr_failure:
 121         return -1;
 122 }
 123
 124 static inline int
 125 ctnetlink_dump_timeout(struct sk_buff *skb, const struct nf_conn *ct)
 126 {
 127         long timeout_l = ct->timeout.expires - jiffies;
 128         u_int32_t timeout;
 129
 130         if (timeout_l < 0)
 131                 timeout = 0;
 132         else
 133                 timeout = htonl(timeout_l / HZ);
 134
 135         NFA_PUT(skb, CTA_TIMEOUT, sizeof(timeout), &timeout);
 136         return 0;
 137
 138 nfattr_failure:
 139         return -1;
 140 }
 141
 142 static inline int
 143 ctnetlink_dump_protoinfo(struct sk_buff *skb, const struct nf_conn *ct)
 144 {
 145         struct nf_conntrack_l4proto *l4proto = nf_ct_l4proto_find_get(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num, ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum);
 146         struct nfattr *nest_proto;
 147         int ret;
 148
 149         if (!l4proto->to_nfattr) {
 150                 nf_ct_l4proto_put(l4proto);
 151                 return 0;
 152         }
 153
 154         nest_proto = NFA_NEST(skb, CTA_PROTOINFO);
 155
 156         ret = l4proto->to_nfattr(skb, nest_proto, ct);
 157
 158         nf_ct_l4proto_put(l4proto);
 159
 160         NFA_NEST_END(skb, nest_proto);
 161
 162         return ret;
 163
 164 nfattr_failure:
 165         nf_ct_l4proto_put(l4proto);
 166         return -1;
 167 }
 168
 169 static inline int
 170 ctnetlink_dump_helpinfo(struct sk_buff *skb, const struct nf_conn *ct)
 171 {
 172         struct nfattr *nest_helper;
 173         const struct nf_conn_help *help = nfct_help(ct);
 174
 175         if (!help || !help->helper)
 176                 return 0;
 177
 178         nest_helper = NFA_NEST(skb, CTA_HELP);
 179         NFA_PUT(skb, CTA_HELP_NAME, strlen(help->helper->name), help->helper->name);
 180
 181         if (help->helper->to_nfattr)
 182                 help->helper->to_nfattr(skb, ct);
 183
 184         NFA_NEST_END(skb, nest_helper);
 185
 186         return 0;
 187
 188 nfattr_failure:
 189         return -1;
 190 }
 191
 192 #ifdef CONFIG_NF_CT_ACCT
 193 static inline int
 194 ctnetlink_dump_counters(struct sk_buff *skb, const struct nf_conn *ct,
 195                         enum ip_conntrack_dir dir)
 196 {
 197         enum ctattr_type type = dir ? CTA_COUNTERS_REPLY: CTA_COUNTERS_ORIG;
 198         struct nfattr *nest_count = NFA_NEST(skb, type);
 199         u_int32_t tmp;
 200
 201         tmp = htonl(ct->counters[dir].packets);
 202         NFA_PUT(skb, CTA_COUNTERS32_PACKETS, sizeof(u_int32_t), &tmp);
 203
 204         tmp = htonl(ct->counters[dir].bytes);
 205         NFA_PUT(skb, CTA_COUNTERS32_BYTES, sizeof(u_int32_t), &tmp);
 206
 207         NFA_NEST_END(skb, nest_count);
 208
 209         return 0;
 210
 211 nfattr_failure:
 212         return -1;
 213 }
 214 #else
 215 #define ctnetlink_dump_counters(a, b, c) (0)
 216 #endif
 217
 218 #ifdef CONFIG_NF_CONNTRACK_MARK
 219 static inline int
 220 ctnetlink_dump_mark(struct sk_buff *skb, const struct nf_conn *ct)
 221 {
 222         u_int32_t mark = htonl(ct->mark);
 223
 224         NFA_PUT(skb, CTA_MARK, sizeof(u_int32_t), &mark);
 225         return 0;
 226
 227 nfattr_failure:
 228         return -1;
 229 }
 230 #else
 231 #define ctnetlink_dump_mark(a, b) (0)
 232 #endif
 233
 234 static inline int
 235 ctnetlink_dump_id(struct sk_buff *skb, const struct nf_conn *ct)
 236 {
 237         u_int32_t id = htonl(ct->id);
 238         NFA_PUT(skb, CTA_ID, sizeof(u_int32_t), &id);
 239         return 0;
 240
 241 nfattr_failure:
 242         return -1;
 243 }
 244
 245 static inline int
 246 ctnetlink_dump_use(struct sk_buff *skb, const struct nf_conn *ct)
 247 {
 248         u_int32_t use = htonl(atomic_read(&ct->ct_general.use));
 249
 250         NFA_PUT(skb, CTA_USE, sizeof(u_int32_t), &use);
 251         return 0;
 252
 253 nfattr_failure:
 254         return -1;
 255 }
 256
 257 #define tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
 258
 259 static int
 260 ctnetlink_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
 261                     int event, int nowait,
 262                     const struct nf_conn *ct)
 263 {
 264         struct nlmsghdr *nlh;
 265         struct nfgenmsg *nfmsg;
 266         struct nfattr *nest_parms;
 267         unsigned char *b;
 268
 269         b = skb->tail;
 270
 271         event |= NFNL_SUBSYS_CTNETLINK << 8;
 272         nlh    = NLMSG_PUT(skb, pid, seq, event, sizeof(struct nfgenmsg));
 273         nfmsg  = NLMSG_DATA(nlh);
 274
 275         nlh->nlmsg_flags    = (nowait && pid) ? NLM_F_MULTI : 0;
 276         nfmsg->nfgen_family =
 277                 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 278         nfmsg->version      = NFNETLINK_V0;
 279         nfmsg->res_id       = 0;
 280
 281         nest_parms = NFA_NEST(skb, CTA_TUPLE_ORIG);
 282         if (ctnetlink_dump_tuples(skb, tuple(ct, IP_CT_DIR_ORIGINAL)) < 0)
 283                 goto nfattr_failure;
 284         NFA_NEST_END(skb, nest_parms);
 285
 286         nest_parms = NFA_NEST(skb, CTA_TUPLE_REPLY);
 287         if (ctnetlink_dump_tuples(skb, tuple(ct, IP_CT_DIR_REPLY)) < 0)
 288                 goto nfattr_failure;
 289         NFA_NEST_END(skb, nest_parms);
 290
 291         if (ctnetlink_dump_status(skb, ct) < 0 ||
 292             ctnetlink_dump_timeout(skb, ct) < 0 ||
 293             ctnetlink_dump_counters(skb, ct, IP_CT_DIR_ORIGINAL) < 0 ||
 294             ctnetlink_dump_counters(skb, ct, IP_CT_DIR_REPLY) < 0 ||
 295             ctnetlink_dump_protoinfo(skb, ct) < 0 ||
 296             ctnetlink_dump_helpinfo(skb, ct) < 0 ||
 297             ctnetlink_dump_mark(skb, ct) < 0 ||
 298             ctnetlink_dump_id(skb, ct) < 0 ||
 299             ctnetlink_dump_use(skb, ct) < 0)
 300                 goto nfattr_failure;
 301
 302         nlh->nlmsg_len = skb->tail - b;
 303         return skb->len;
 304
 305 nlmsg_failure:
 306 nfattr_failure:
 307         skb_trim(skb, b - skb->data);
 308         return -1;
 309 }
 310
 311 #ifdef CONFIG_NF_CONNTRACK_EVENTS
 312 static int ctnetlink_conntrack_event(struct notifier_block *this,
 313                                      unsigned long events, void *ptr)
 314 {
 315         struct nlmsghdr *nlh;
 316         struct nfgenmsg *nfmsg;
 317         struct nfattr *nest_parms;
 318         struct nf_conn *ct = (struct nf_conn *)ptr;
 319         struct sk_buff *skb;
 320         unsigned int type;
 321         unsigned char *b;
 322         unsigned int flags = 0, group;
 323
 324         /* ignore our fake conntrack entry */
 325         if (ct == &nf_conntrack_untracked)
 326                 return NOTIFY_DONE;
 327
 328         if (events & IPCT_DESTROY) {
 329                 type = IPCTNL_MSG_CT_DELETE;
 330                 group = NFNLGRP_CONNTRACK_DESTROY;
 331         } else  if (events & (IPCT_NEW | IPCT_RELATED)) {
 332                 type = IPCTNL_MSG_CT_NEW;
 333                 flags = NLM_F_CREATE|NLM_F_EXCL;
 334                 /* dump everything */
 335                 events = ~0UL;
 336                 group = NFNLGRP_CONNTRACK_NEW;
 337         } else  if (events & (IPCT_STATUS | IPCT_PROTOINFO)) {
 338                 type = IPCTNL_MSG_CT_NEW;
 339                 group = NFNLGRP_CONNTRACK_UPDATE;
 340         } else
 341                 return NOTIFY_DONE;
 342
 343         if (!nfnetlink_has_listeners(group))
 344                 return NOTIFY_DONE;
 345
 346         skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
 347         if (!skb)
 348                 return NOTIFY_DONE;
 349
 350         b = skb->tail;
 351
 352         type |= NFNL_SUBSYS_CTNETLINK << 8;
 353         nlh   = NLMSG_PUT(skb, 0, 0, type, sizeof(struct nfgenmsg));
 354         nfmsg = NLMSG_DATA(nlh);
 355
 356         nlh->nlmsg_flags    = flags;
 357         nfmsg->nfgen_family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 358         nfmsg->version  = NFNETLINK_V0;
 359         nfmsg->res_id   = 0;
 360
 361         nest_parms = NFA_NEST(skb, CTA_TUPLE_ORIG);
 362         if (ctnetlink_dump_tuples(skb, tuple(ct, IP_CT_DIR_ORIGINAL)) < 0)
 363                 goto nfattr_failure;
 364         NFA_NEST_END(skb, nest_parms);
 365
 366         nest_parms = NFA_NEST(skb, CTA_TUPLE_REPLY);
 367         if (ctnetlink_dump_tuples(skb, tuple(ct, IP_CT_DIR_REPLY)) < 0)
 368                 goto nfattr_failure;
 369         NFA_NEST_END(skb, nest_parms);
 370
 371         /* NAT stuff is now a status flag */
 372         if ((events & IPCT_STATUS || events & IPCT_NATINFO)
 373             && ctnetlink_dump_status(skb, ct) < 0)
 374                 goto nfattr_failure;
 375         if (events & IPCT_REFRESH
 376             && ctnetlink_dump_timeout(skb, ct) < 0)
 377                 goto nfattr_failure;
 378         if (events & IPCT_PROTOINFO
 379             && ctnetlink_dump_protoinfo(skb, ct) < 0)
 380                 goto nfattr_failure;
 381         if (events & IPCT_HELPINFO
 382             && ctnetlink_dump_helpinfo(skb, ct) < 0)
 383                 goto nfattr_failure;
 384
 385         if (ctnetlink_dump_counters(skb, ct, IP_CT_DIR_ORIGINAL) < 0 ||
 386             ctnetlink_dump_counters(skb, ct, IP_CT_DIR_REPLY) < 0)
 387                 goto nfattr_failure;
 388
 389         if (events & IPCT_MARK
 390             && ctnetlink_dump_mark(skb, ct) < 0)
 391                 goto nfattr_failure;
 392
 393         nlh->nlmsg_len = skb->tail - b;
 394         nfnetlink_send(skb, 0, group, 0);
 395         return NOTIFY_DONE;
 396
 397 nlmsg_failure:
 398 nfattr_failure:
 399         kfree_skb(skb);
 400         return NOTIFY_DONE;
 401 }
 402 #endif /* CONFIG_NF_CONNTRACK_EVENTS */
 403
 404 static int ctnetlink_done(struct netlink_callback *cb)
 405 {
 406         if (cb->args[1])
 407                 nf_ct_put((struct nf_conn *)cb->args[1]);
 408         return 0;
 409 }
 410
 411 #define L3PROTO(ct) ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num
 412
 413 static int
 414 ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
 415 {
 416         struct nf_conn *ct, *last;
 417         struct nf_conntrack_tuple_hash *h;
 418         struct list_head *i;
 419         struct nfgenmsg *nfmsg = NLMSG_DATA(cb->nlh);
 420         u_int8_t l3proto = nfmsg->nfgen_family;
 421
 422         read_lock_bh(&nf_conntrack_lock);
 423         last = (struct nf_conn *)cb->args[1];
 424         for (; cb->args[0] < nf_conntrack_htable_size; cb->args[0]++) {
 425 restart:
 426                 list_for_each_prev(i, &nf_conntrack_hash[cb->args[0]]) {
 427                         h = (struct nf_conntrack_tuple_hash *) i;
 428                         if (DIRECTION(h) != IP_CT_DIR_ORIGINAL)
 429                                 continue;
 430                         ct = nf_ct_tuplehash_to_ctrack(h);
 431                         /* Dump entries of a given L3 protocol number.
 432                          * If it is not specified, ie. l3proto == 0,
 433                          * then dump everything. */
 434                         if (l3proto && L3PROTO(ct) != l3proto)
 435                                 continue;
 436                         if (cb->args[1]) {
 437                                 if (ct != last)
 438                                         continue;
 439                                 cb->args[1] = 0;
 440                         }
 441                         if (ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).pid,
 442                                                 cb->nlh->nlmsg_seq,
 443                                                 IPCTNL_MSG_CT_NEW,
 444                                                 1, ct) < 0) {
 445                                 nf_conntrack_get(&ct->ct_general);
 446                                 cb->args[1] = (unsigned long)ct;
 447                                 goto out;
 448                         }
 449 #ifdef CONFIG_NF_CT_ACCT
 450                         if (NFNL_MSG_TYPE(cb->nlh->nlmsg_type) ==
 451                                                 IPCTNL_MSG_CT_GET_CTRZERO)
 452                                 memset(&ct->counters, 0, sizeof(ct->counters));
 453 #endif
 454                 }
 455                 if (cb->args[1]) {
 456                         cb->args[1] = 0;
 457                         goto restart;
 458                 }
 459         }
 460 out:
 461         read_unlock_bh(&nf_conntrack_lock);
 462         if (last)
 463                 nf_ct_put(last);
 464
 465         return skb->len;
 466 }
 467
 468 static inline int
 469 ctnetlink_parse_tuple_ip(struct nfattr *attr, struct nf_conntrack_tuple *tuple)
 470 {
 471         struct nfattr *tb[CTA_IP_MAX];
 472         struct nf_conntrack_l3proto *l3proto;
 473         int ret = 0;
 474
 475         nfattr_parse_nested(tb, CTA_IP_MAX, attr);
 476
 477         l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);
 478
 479         if (likely(l3proto->nfattr_to_tuple))
 480                 ret = l3proto->nfattr_to_tuple(tb, tuple);
 481
 482         nf_ct_l3proto_put(l3proto);
 483
 484         return ret;
 485 }
 486
 487 static const size_t cta_min_proto[CTA_PROTO_MAX] = {
 488         [CTA_PROTO_NUM-1]       = sizeof(u_int8_t),
 489 };
 490
 491 static inline int
 492 ctnetlink_parse_tuple_proto(struct nfattr *attr,
 493                             struct nf_conntrack_tuple *tuple)
 494 {
 495         struct nfattr *tb[CTA_PROTO_MAX];
 496         struct nf_conntrack_l4proto *l4proto;
 497         int ret = 0;
 498
 499         nfattr_parse_nested(tb, CTA_PROTO_MAX, attr);
 500
 501         if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto))
 502                 return -EINVAL;
 503
 504         if (!tb[CTA_PROTO_NUM-1])
 505                 return -EINVAL;
 506         tuple->dst.protonum = *(u_int8_t *)NFA_DATA(tb[CTA_PROTO_NUM-1]);
 507
 508         l4proto = nf_ct_l4proto_find_get(tuple->src.l3num, tuple->dst.protonum);
 509
 510         if (likely(l4proto->nfattr_to_tuple))
 511                 ret = l4proto->nfattr_to_tuple(tb, tuple);
 512
 513         nf_ct_l4proto_put(l4proto);
 514
 515         return ret;
 516 }
 517
 518 static inline int
 519 ctnetlink_parse_tuple(struct nfattr *cda[], struct nf_conntrack_tuple *tuple,
 520                       enum ctattr_tuple type, u_int8_t l3num)
 521 {
 522         struct nfattr *tb[CTA_TUPLE_MAX];
 523         int err;
 524
 525         memset(tuple, 0, sizeof(*tuple));
 526
 527         nfattr_parse_nested(tb, CTA_TUPLE_MAX, cda[type-1]);
 528
 529         if (!tb[CTA_TUPLE_IP-1])
 530                 return -EINVAL;
 531
 532         tuple->src.l3num = l3num;
 533
 534         err = ctnetlink_parse_tuple_ip(tb[CTA_TUPLE_IP-1], tuple);
 535         if (err < 0)
 536                 return err;
 537
 538         if (!tb[CTA_TUPLE_PROTO-1])
 539                 return -EINVAL;
 540
 541         err = ctnetlink_parse_tuple_proto(tb[CTA_TUPLE_PROTO-1], tuple);
 542         if (err < 0)
 543                 return err;
 544
 545         /* orig and expect tuples get DIR_ORIGINAL */
 546         if (type == CTA_TUPLE_REPLY)
 547                 tuple->dst.dir = IP_CT_DIR_REPLY;
 548         else
 549                 tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 550
 551         return 0;
 552 }
 553
 554 #ifdef CONFIG_IP_NF_NAT_NEEDED
 555 static const size_t cta_min_protonat[CTA_PROTONAT_MAX] = {
 556         [CTA_PROTONAT_PORT_MIN-1]       = sizeof(u_int16_t),
 557         [CTA_PROTONAT_PORT_MAX-1]       = sizeof(u_int16_t),
 558 };
 559
 560 static int ctnetlink_parse_nat_proto(struct nfattr *attr,
 561                                      const struct nf_conn *ct,
 562                                      struct ip_nat_range *range)
 563 {
 564         struct nfattr *tb[CTA_PROTONAT_MAX];
 565         struct ip_nat_protocol *npt;
 566
 567         nfattr_parse_nested(tb, CTA_PROTONAT_MAX, attr);
 568
 569         if (nfattr_bad_size(tb, CTA_PROTONAT_MAX, cta_min_protonat))
 570                 return -EINVAL;
 571
 572         npt = ip_nat_proto_find_get(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum);
 573
 574         if (!npt->nfattr_to_range) {
 575                 ip_nat_proto_put(npt);
 576                 return 0;
 577         }
 578
 579         /* nfattr_to_range returns 1 if it parsed, 0 if not, neg. on error */
 580         if (npt->nfattr_to_range(tb, range) > 0)
 581                 range->flags |= IP_NAT_RANGE_PROTO_SPECIFIED;
 582
 583         ip_nat_proto_put(npt);
 584
 585         return 0;
 586 }
 587
 588 static const size_t cta_min_nat[CTA_NAT_MAX] = {
 589         [CTA_NAT_MINIP-1]       = sizeof(u_int32_t),
 590         [CTA_NAT_MAXIP-1]       = sizeof(u_int32_t),
 591 };
 592
 593 static inline int
 594 ctnetlink_parse_nat(struct nfattr *nat,
 595                     const struct nf_conn *ct, struct ip_nat_range *range)
 596 {
 597         struct nfattr *tb[CTA_NAT_MAX];
 598         int err;
 599
 600         memset(range, 0, sizeof(*range));
 601
 602         nfattr_parse_nested(tb, CTA_NAT_MAX, nat);
 603
 604         if (nfattr_bad_size(tb, CTA_NAT_MAX, cta_min_nat))
 605                 return -EINVAL;
 606
 607         if (tb[CTA_NAT_MINIP-1])
 608                 range->min_ip = *(u_int32_t *)NFA_DATA(tb[CTA_NAT_MINIP-1]);
 609
 610         if (!tb[CTA_NAT_MAXIP-1])
 611                 range->max_ip = range->min_ip;
 612         else
 613                 range->max_ip = *(u_int32_t *)NFA_DATA(tb[CTA_NAT_MAXIP-1]);
 614
 615         if (range->min_ip)
 616                 range->flags |= IP_NAT_RANGE_MAP_IPS;
 617
 618         if (!tb[CTA_NAT_PROTO-1])
 619                 return 0;
 620
 621         err = ctnetlink_parse_nat_proto(tb[CTA_NAT_PROTO-1], ct, range);
 622         if (err < 0)
 623                 return err;
 624
 625         return 0;
 626 }
 627 #endif
 628
 629 static inline int
 630 ctnetlink_parse_help(struct nfattr *attr, char **helper_name)
 631 {
 632         struct nfattr *tb[CTA_HELP_MAX];
 633
 634         nfattr_parse_nested(tb, CTA_HELP_MAX, attr);
 635
 636         if (!tb[CTA_HELP_NAME-1])
 637                 return -EINVAL;
 638
 639         *helper_name = NFA_DATA(tb[CTA_HELP_NAME-1]);
 640
 641         return 0;
 642 }
 643
 644 static const size_t cta_min[CTA_MAX] = {
 645         [CTA_STATUS-1]          = sizeof(u_int32_t),
 646         [CTA_TIMEOUT-1]         = sizeof(u_int32_t),
 647         [CTA_MARK-1]            = sizeof(u_int32_t),
 648         [CTA_USE-1]             = sizeof(u_int32_t),
 649         [CTA_ID-1]              = sizeof(u_int32_t)
 650 };
 651
 652 static int
 653 ctnetlink_del_conntrack(struct sock *ctnl, struct sk_buff *skb,
 654                         struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
 655 {
 656         struct nf_conntrack_tuple_hash *h;
 657         struct nf_conntrack_tuple tuple;
 658         struct nf_conn *ct;
 659         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 660         u_int8_t u3 = nfmsg->nfgen_family;
 661         int err = 0;
 662
 663         if (nfattr_bad_size(cda, CTA_MAX, cta_min))
 664                 return -EINVAL;
 665
 666         if (cda[CTA_TUPLE_ORIG-1])
 667                 err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_ORIG, u3);
 668         else if (cda[CTA_TUPLE_REPLY-1])
 669                 err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_REPLY, u3);
 670         else {
 671                 /* Flush the whole table */
 672                 nf_conntrack_flush();
 673                 return 0;
 674         }
 675
 676         if (err < 0)
 677                 return err;
 678
 679         h = nf_conntrack_find_get(&tuple, NULL);
 680         if (!h)
 681                 return -ENOENT;
 682
 683         ct = nf_ct_tuplehash_to_ctrack(h);
 684
 685         if (cda[CTA_ID-1]) {
 686                 u_int32_t id = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_ID-1]));
 687                 if (ct->id != id) {
 688                         nf_ct_put(ct);
 689                         return -ENOENT;
 690                 }
 691         }
 692         if (del_timer(&ct->timeout))
 693                 ct->timeout.function((unsigned long)ct);
 694
 695         nf_ct_put(ct);
 696
 697         return 0;
 698 }
 699
 700 static int
 701 ctnetlink_get_conntrack(struct sock *ctnl, struct sk_buff *skb,
 702                         struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
 703 {
 704         struct nf_conntrack_tuple_hash *h;
 705         struct nf_conntrack_tuple tuple;
 706         struct nf_conn *ct;
 707         struct sk_buff *skb2 = NULL;
 708         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
 709         u_int8_t u3 = nfmsg->nfgen_family;
 710         int err = 0;
 711
 712         if (nlh->nlmsg_flags & NLM_F_DUMP) {
 713                 u32 rlen;
 714
 715 #ifndef CONFIG_NF_CT_ACCT
 716                 if (NFNL_MSG_TYPE(nlh->nlmsg_type) == IPCTNL_MSG_CT_GET_CTRZERO)
 717                         return -ENOTSUPP;
 718 #endif
 719                 if ((*errp = netlink_dump_start(ctnl, skb, nlh,
 720                                                 ctnetlink_dump_table,
 721                                                 ctnetlink_done)) != 0)
 722                         return -EINVAL;
 723
 724                 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
 725                 if (rlen > skb->len)
 726                         rlen = skb->len;
 727                 skb_pull(skb, rlen);
 728                 return 0;
 729         }
 730
 731         if (nfattr_bad_size(cda, CTA_MAX, cta_min))
 732                 return -EINVAL;
 733
 734         if (cda[CTA_TUPLE_ORIG-1])
 735                 err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_ORIG, u3);
 736         else if (cda[CTA_TUPLE_REPLY-1])
 737                 err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_REPLY, u3);
 738         else
 739                 return -EINVAL;
 740
 741         if (err < 0)
 742                 return err;
 743
 744         h = nf_conntrack_find_get(&tuple, NULL);
 745         if (!h)
 746                 return -ENOENT;
 747
 748         ct = nf_ct_tuplehash_to_ctrack(h);
 749
 750         err = -ENOMEM;
 751         skb2 = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 752         if (!skb2) {
 753                 nf_ct_put(ct);
 754                 return -ENOMEM;
 755         }
 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_l4proto *l4proto;
 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         l4proto = nf_ct_l4proto_find_get(l3num, npt);
 901
 902         if (l4proto->from_nfattr)
 903                 err = l4proto->from_nfattr(tb, ct);
 904         nf_ct_l4proto_put(l4proto);
 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         if (cda[CTA_STATUS-1]) {
 967                 err = ctnetlink_change_status(ct, cda);
 968                 if (err < 0)
 969                         goto err;
 970         }
 971
 972         if (cda[CTA_PROTOINFO-1]) {
 973                 err = ctnetlink_change_protoinfo(ct, cda);
 974                 if (err < 0)
 975                         return err;
 976         }
 977
 978 #if defined(CONFIG_NF_CONNTRACK_MARK)
 979         if (cda[CTA_MARK-1])
 980                 ct->mark = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_MARK-1]));
 981 #endif
 982
 983         help = nfct_help(ct);
 984         if (help)
 985                 help->helper = nf_ct_helper_find_get(rtuple);
 986
 987         add_timer(&ct->timeout);
 988         nf_conntrack_hash_insert(ct);
 989
 990         if (help && help->helper)
 991                 nf_ct_helper_put(help->helper);
 992
 993         return 0;
 994
 995 err:
 996         nf_conntrack_free(ct);
 997         return err;
 998 }
 999
1000 static int
1001 ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
1002                         struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
1003 {
1004         struct nf_conntrack_tuple otuple, rtuple;
1005         struct nf_conntrack_tuple_hash *h = NULL;
1006         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
1007         u_int8_t u3 = nfmsg->nfgen_family;
1008         int err = 0;
1009
1010         if (nfattr_bad_size(cda, CTA_MAX, cta_min))
1011                 return -EINVAL;
1012
1013         if (cda[CTA_TUPLE_ORIG-1]) {
1014                 err = ctnetlink_parse_tuple(cda, &otuple, CTA_TUPLE_ORIG, u3);
1015                 if (err < 0)
1016                         return err;
1017         }
1018
1019         if (cda[CTA_TUPLE_REPLY-1]) {
1020                 err = ctnetlink_parse_tuple(cda, &rtuple, CTA_TUPLE_REPLY, u3);
1021                 if (err < 0)
1022                         return err;
1023         }
1024
1025         write_lock_bh(&nf_conntrack_lock);
1026         if (cda[CTA_TUPLE_ORIG-1])
1027                 h = __nf_conntrack_find(&otuple, NULL);
1028         else if (cda[CTA_TUPLE_REPLY-1])
1029                 h = __nf_conntrack_find(&rtuple, NULL);
1030
1031         if (h == NULL) {
1032                 write_unlock_bh(&nf_conntrack_lock);
1033                 err = -ENOENT;
1034                 if (nlh->nlmsg_flags & NLM_F_CREATE)
1035                         err = ctnetlink_create_conntrack(cda, &otuple, &rtuple);
1036                 return err;
1037         }
1038         /* implicit 'else' */
1039
1040         /* we only allow nat config for new conntracks */
1041         if (cda[CTA_NAT_SRC-1] || cda[CTA_NAT_DST-1]) {
1042                 err = -EINVAL;
1043                 goto out_unlock;
1044         }
1045
1046         /* We manipulate the conntrack inside the global conntrack table lock,
1047          * so there's no need to increase the refcount */
1048         err = -EEXIST;
1049         if (!(nlh->nlmsg_flags & NLM_F_EXCL))
1050                 err = ctnetlink_change_conntrack(nf_ct_tuplehash_to_ctrack(h), cda);
1051
1052 out_unlock:
1053         write_unlock_bh(&nf_conntrack_lock);
1054         return err;
1055 }
1056
1057 /***********************************************************************
1058  * EXPECT
1059  ***********************************************************************/
1060
1061 static inline int
1062 ctnetlink_exp_dump_tuple(struct sk_buff *skb,
1063                          const struct nf_conntrack_tuple *tuple,
1064                          enum ctattr_expect type)
1065 {
1066         struct nfattr *nest_parms = NFA_NEST(skb, type);
1067
1068         if (ctnetlink_dump_tuples(skb, tuple) < 0)
1069                 goto nfattr_failure;
1070
1071         NFA_NEST_END(skb, nest_parms);
1072
1073         return 0;
1074
1075 nfattr_failure:
1076         return -1;
1077 }
1078
1079 static inline int
1080 ctnetlink_exp_dump_mask(struct sk_buff *skb,
1081                         const struct nf_conntrack_tuple *tuple,
1082                         const struct nf_conntrack_tuple *mask)
1083 {
1084         int ret;
1085         struct nf_conntrack_l3proto *l3proto;
1086         struct nf_conntrack_l4proto *l4proto;
1087         struct nfattr *nest_parms = NFA_NEST(skb, CTA_EXPECT_MASK);
1088
1089         l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);
1090         ret = ctnetlink_dump_tuples_ip(skb, mask, l3proto);
1091         nf_ct_l3proto_put(l3proto);
1092
1093         if (unlikely(ret < 0))
1094                 goto nfattr_failure;
1095
1096         l4proto = nf_ct_l4proto_find_get(tuple->src.l3num, tuple->dst.protonum);
1097         ret = ctnetlink_dump_tuples_proto(skb, mask, l4proto);
1098         nf_ct_l4proto_put(l4proto);
1099         if (unlikely(ret < 0))
1100                 goto nfattr_failure;
1101
1102         NFA_NEST_END(skb, nest_parms);
1103
1104         return 0;
1105
1106 nfattr_failure:
1107         return -1;
1108 }
1109
1110 static inline int
1111 ctnetlink_exp_dump_expect(struct sk_buff *skb,
1112                           const struct nf_conntrack_expect *exp)
1113 {
1114         struct nf_conn *master = exp->master;
1115         u_int32_t timeout = htonl((exp->timeout.expires - jiffies) / HZ);
1116         u_int32_t id = htonl(exp->id);
1117
1118         if (ctnetlink_exp_dump_tuple(skb, &exp->tuple, CTA_EXPECT_TUPLE) < 0)
1119                 goto nfattr_failure;
1120         if (ctnetlink_exp_dump_mask(skb, &exp->tuple, &exp->mask) < 0)
1121                 goto nfattr_failure;
1122         if (ctnetlink_exp_dump_tuple(skb,
1123                                  &master->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
1124                                  CTA_EXPECT_MASTER) < 0)
1125                 goto nfattr_failure;
1126
1127         NFA_PUT(skb, CTA_EXPECT_TIMEOUT, sizeof(timeout), &timeout);
1128         NFA_PUT(skb, CTA_EXPECT_ID, sizeof(u_int32_t), &id);
1129
1130         return 0;
1131
1132 nfattr_failure:
1133         return -1;
1134 }
1135
1136 static int
1137 ctnetlink_exp_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
1138                     int event,
1139                     int nowait,
1140                     const struct nf_conntrack_expect *exp)
1141 {
1142         struct nlmsghdr *nlh;
1143         struct nfgenmsg *nfmsg;
1144         unsigned char *b;
1145
1146         b = skb->tail;
1147
1148         event |= NFNL_SUBSYS_CTNETLINK_EXP << 8;
1149         nlh    = NLMSG_PUT(skb, pid, seq, event, sizeof(struct nfgenmsg));
1150         nfmsg  = NLMSG_DATA(nlh);
1151
1152         nlh->nlmsg_flags    = (nowait && pid) ? NLM_F_MULTI : 0;
1153         nfmsg->nfgen_family = exp->tuple.src.l3num;
1154         nfmsg->version      = NFNETLINK_V0;
1155         nfmsg->res_id       = 0;
1156
1157         if (ctnetlink_exp_dump_expect(skb, exp) < 0)
1158                 goto nfattr_failure;
1159
1160         nlh->nlmsg_len = skb->tail - b;
1161         return skb->len;
1162
1163 nlmsg_failure:
1164 nfattr_failure:
1165         skb_trim(skb, b - skb->data);
1166         return -1;
1167 }
1168
1169 #ifdef CONFIG_NF_CONNTRACK_EVENTS
1170 static int ctnetlink_expect_event(struct notifier_block *this,
1171                                   unsigned long events, void *ptr)
1172 {
1173         struct nlmsghdr *nlh;
1174         struct nfgenmsg *nfmsg;
1175         struct nf_conntrack_expect *exp = (struct nf_conntrack_expect *)ptr;
1176         struct sk_buff *skb;
1177         unsigned int type;
1178         unsigned char *b;
1179         int flags = 0;
1180
1181         if (events & IPEXP_NEW) {
1182                 type = IPCTNL_MSG_EXP_NEW;
1183                 flags = NLM_F_CREATE|NLM_F_EXCL;
1184         } else
1185                 return NOTIFY_DONE;
1186
1187         if (!nfnetlink_has_listeners(NFNLGRP_CONNTRACK_EXP_NEW))
1188                 return NOTIFY_DONE;
1189
1190         skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
1191         if (!skb)
1192                 return NOTIFY_DONE;
1193
1194         b = skb->tail;
1195
1196         type |= NFNL_SUBSYS_CTNETLINK_EXP << 8;
1197         nlh   = NLMSG_PUT(skb, 0, 0, type, sizeof(struct nfgenmsg));
1198         nfmsg = NLMSG_DATA(nlh);
1199
1200         nlh->nlmsg_flags    = flags;
1201         nfmsg->nfgen_family = exp->tuple.src.l3num;
1202         nfmsg->version      = NFNETLINK_V0;
1203         nfmsg->res_id       = 0;
1204
1205         if (ctnetlink_exp_dump_expect(skb, exp) < 0)
1206                 goto nfattr_failure;
1207
1208         nlh->nlmsg_len = skb->tail - b;
1209         nfnetlink_send(skb, 0, NFNLGRP_CONNTRACK_EXP_NEW, 0);
1210         return NOTIFY_DONE;
1211
1212 nlmsg_failure:
1213 nfattr_failure:
1214         kfree_skb(skb);
1215         return NOTIFY_DONE;
1216 }
1217 #endif
1218
1219 static int
1220 ctnetlink_exp_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
1221 {
1222         struct nf_conntrack_expect *exp = NULL;
1223         struct list_head *i;
1224         u_int32_t *id = (u_int32_t *) &cb->args[0];
1225         struct nfgenmsg *nfmsg = NLMSG_DATA(cb->nlh);
1226         u_int8_t l3proto = nfmsg->nfgen_family;
1227
1228         read_lock_bh(&nf_conntrack_lock);
1229         list_for_each_prev(i, &nf_conntrack_expect_list) {
1230                 exp = (struct nf_conntrack_expect *) i;
1231                 if (l3proto && exp->tuple.src.l3num != l3proto)
1232                         continue;
1233                 if (exp->id <= *id)
1234                         continue;
1235                 if (ctnetlink_exp_fill_info(skb, NETLINK_CB(cb->skb).pid,
1236                                             cb->nlh->nlmsg_seq,
1237                                             IPCTNL_MSG_EXP_NEW,
1238                                             1, exp) < 0)
1239                         goto out;
1240                 *id = exp->id;
1241         }
1242 out:
1243         read_unlock_bh(&nf_conntrack_lock);
1244
1245         return skb->len;
1246 }
1247
1248 static const size_t cta_min_exp[CTA_EXPECT_MAX] = {
1249         [CTA_EXPECT_TIMEOUT-1]          = sizeof(u_int32_t),
1250         [CTA_EXPECT_ID-1]               = sizeof(u_int32_t)
1251 };
1252
1253 static int
1254 ctnetlink_get_expect(struct sock *ctnl, struct sk_buff *skb,
1255                      struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
1256 {
1257         struct nf_conntrack_tuple tuple;
1258         struct nf_conntrack_expect *exp;
1259         struct sk_buff *skb2;
1260         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
1261         u_int8_t u3 = nfmsg->nfgen_family;
1262         int err = 0;
1263
1264         if (nfattr_bad_size(cda, CTA_EXPECT_MAX, cta_min_exp))
1265                 return -EINVAL;
1266
1267         if (nlh->nlmsg_flags & NLM_F_DUMP) {
1268                 u32 rlen;
1269
1270                 if ((*errp = netlink_dump_start(ctnl, skb, nlh,
1271                                                 ctnetlink_exp_dump_table,
1272                                                 ctnetlink_done)) != 0)
1273                         return -EINVAL;
1274                 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
1275                 if (rlen > skb->len)
1276                         rlen = skb->len;
1277                 skb_pull(skb, rlen);
1278                 return 0;
1279         }
1280
1281         if (cda[CTA_EXPECT_MASTER-1])
1282                 err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_MASTER, u3);
1283         else
1284                 return -EINVAL;
1285
1286         if (err < 0)
1287                 return err;
1288
1289         exp = nf_conntrack_expect_find_get(&tuple);
1290         if (!exp)
1291                 return -ENOENT;
1292
1293         if (cda[CTA_EXPECT_ID-1]) {
1294                 u_int32_t id = *(u_int32_t *)NFA_DATA(cda[CTA_EXPECT_ID-1]);
1295                 if (exp->id != ntohl(id)) {
1296                         nf_conntrack_expect_put(exp);
1297                         return -ENOENT;
1298                 }
1299         }
1300
1301         err = -ENOMEM;
1302         skb2 = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1303         if (!skb2)
1304                 goto out;
1305
1306         err = ctnetlink_exp_fill_info(skb2, NETLINK_CB(skb).pid,
1307                                       nlh->nlmsg_seq, IPCTNL_MSG_EXP_NEW,
1308                                       1, exp);
1309         if (err <= 0)
1310                 goto free;
1311
1312         nf_conntrack_expect_put(exp);
1313
1314         return netlink_unicast(ctnl, skb2, NETLINK_CB(skb).pid, MSG_DONTWAIT);
1315
1316 free:
1317         kfree_skb(skb2);
1318 out:
1319         nf_conntrack_expect_put(exp);
1320         return err;
1321 }
1322
1323 static int
1324 ctnetlink_del_expect(struct sock *ctnl, struct sk_buff *skb,
1325                      struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
1326 {
1327         struct nf_conntrack_expect *exp, *tmp;
1328         struct nf_conntrack_tuple tuple;
1329         struct nf_conntrack_helper *h;
1330         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
1331         u_int8_t u3 = nfmsg->nfgen_family;
1332         int err;
1333
1334         if (nfattr_bad_size(cda, CTA_EXPECT_MAX, cta_min_exp))
1335                 return -EINVAL;
1336
1337         if (cda[CTA_EXPECT_TUPLE-1]) {
1338                 /* delete a single expect by tuple */
1339                 err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE, u3);
1340                 if (err < 0)
1341                         return err;
1342
1343                 /* bump usage count to 2 */
1344                 exp = nf_conntrack_expect_find_get(&tuple);
1345                 if (!exp)
1346                         return -ENOENT;
1347
1348                 if (cda[CTA_EXPECT_ID-1]) {
1349                         u_int32_t id =
1350                                 *(u_int32_t *)NFA_DATA(cda[CTA_EXPECT_ID-1]);
1351                         if (exp->id != ntohl(id)) {
1352                                 nf_conntrack_expect_put(exp);
1353                                 return -ENOENT;
1354                         }
1355                 }
1356
1357                 /* after list removal, usage count == 1 */
1358                 nf_conntrack_unexpect_related(exp);
1359                 /* have to put what we 'get' above.
1360                  * after this line usage count == 0 */
1361                 nf_conntrack_expect_put(exp);
1362         } else if (cda[CTA_EXPECT_HELP_NAME-1]) {
1363                 char *name = NFA_DATA(cda[CTA_EXPECT_HELP_NAME-1]);
1364
1365                 /* delete all expectations for this helper */
1366                 write_lock_bh(&nf_conntrack_lock);
1367                 h = __nf_conntrack_helper_find_byname(name);
1368                 if (!h) {
1369                         write_unlock_bh(&nf_conntrack_lock);
1370                         return -EINVAL;
1371                 }
1372                 list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list,
1373                                          list) {
1374                         struct nf_conn_help *m_help = nfct_help(exp->master);
1375                         if (m_help->helper == h
1376                             && del_timer(&exp->timeout)) {
1377                                 nf_ct_unlink_expect(exp);
1378                                 nf_conntrack_expect_put(exp);
1379                         }
1380                 }
1381                 write_unlock_bh(&nf_conntrack_lock);
1382         } else {
1383                 /* This basically means we have to flush everything*/
1384                 write_lock_bh(&nf_conntrack_lock);
1385                 list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list,
1386                                          list) {
1387                         if (del_timer(&exp->timeout)) {
1388                                 nf_ct_unlink_expect(exp);
1389                                 nf_conntrack_expect_put(exp);
1390                         }
1391                 }
1392                 write_unlock_bh(&nf_conntrack_lock);
1393         }
1394
1395         return 0;
1396 }
1397 static int
1398 ctnetlink_change_expect(struct nf_conntrack_expect *x, struct nfattr *cda[])
1399 {
1400         return -EOPNOTSUPP;
1401 }
1402
1403 static int
1404 ctnetlink_create_expect(struct nfattr *cda[], u_int8_t u3)
1405 {
1406         struct nf_conntrack_tuple tuple, mask, master_tuple;
1407         struct nf_conntrack_tuple_hash *h = NULL;
1408         struct nf_conntrack_expect *exp;
1409         struct nf_conn *ct;
1410         struct nf_conn_help *help;
1411         int err = 0;
1412
1413         /* caller guarantees that those three CTA_EXPECT_* exist */
1414         err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE, u3);
1415         if (err < 0)
1416                 return err;
1417         err = ctnetlink_parse_tuple(cda, &mask, CTA_EXPECT_MASK, u3);
1418         if (err < 0)
1419                 return err;
1420         err = ctnetlink_parse_tuple(cda, &master_tuple, CTA_EXPECT_MASTER, u3);
1421         if (err < 0)
1422                 return err;
1423
1424         /* Look for master conntrack of this expectation */
1425         h = nf_conntrack_find_get(&master_tuple, NULL);
1426         if (!h)
1427                 return -ENOENT;
1428         ct = nf_ct_tuplehash_to_ctrack(h);
1429         help = nfct_help(ct);
1430
1431         if (!help || !help->helper) {
1432                 /* such conntrack hasn't got any helper, abort */
1433                 err = -EINVAL;
1434                 goto out;
1435         }
1436
1437         exp = nf_conntrack_expect_alloc(ct);
1438         if (!exp) {
1439                 err = -ENOMEM;
1440                 goto out;
1441         }
1442
1443         exp->expectfn = NULL;
1444         exp->flags = 0;
1445         exp->master = ct;
1446         memcpy(&exp->tuple, &tuple, sizeof(struct nf_conntrack_tuple));
1447         memcpy(&exp->mask, &mask, sizeof(struct nf_conntrack_tuple));
1448
1449         err = nf_conntrack_expect_related(exp);
1450         nf_conntrack_expect_put(exp);
1451
1452 out:
1453         nf_ct_put(nf_ct_tuplehash_to_ctrack(h));
1454         return err;
1455 }
1456
1457 static int
1458 ctnetlink_new_expect(struct sock *ctnl, struct sk_buff *skb,
1459                      struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
1460 {
1461         struct nf_conntrack_tuple tuple;
1462         struct nf_conntrack_expect *exp;
1463         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
1464         u_int8_t u3 = nfmsg->nfgen_family;
1465         int err = 0;
1466
1467         if (nfattr_bad_size(cda, CTA_EXPECT_MAX, cta_min_exp))
1468                 return -EINVAL;
1469
1470         if (!cda[CTA_EXPECT_TUPLE-1]
1471             || !cda[CTA_EXPECT_MASK-1]
1472             || !cda[CTA_EXPECT_MASTER-1])
1473                 return -EINVAL;
1474
1475         err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE, u3);
1476         if (err < 0)
1477                 return err;
1478
1479         write_lock_bh(&nf_conntrack_lock);
1480         exp = __nf_conntrack_expect_find(&tuple);
1481
1482         if (!exp) {
1483                 write_unlock_bh(&nf_conntrack_lock);
1484                 err = -ENOENT;
1485                 if (nlh->nlmsg_flags & NLM_F_CREATE)
1486                         err = ctnetlink_create_expect(cda, u3);
1487                 return err;
1488         }
1489
1490         err = -EEXIST;
1491         if (!(nlh->nlmsg_flags & NLM_F_EXCL))
1492                 err = ctnetlink_change_expect(exp, cda);
1493         write_unlock_bh(&nf_conntrack_lock);
1494
1495         return err;
1496 }
1497
1498 #ifdef CONFIG_NF_CONNTRACK_EVENTS
1499 static struct notifier_block ctnl_notifier = {
1500         .notifier_call  = ctnetlink_conntrack_event,
1501 };
1502
1503 static struct notifier_block ctnl_notifier_exp = {
1504         .notifier_call  = ctnetlink_expect_event,
1505 };
1506 #endif
1507
1508 static struct nfnl_callback ctnl_cb[IPCTNL_MSG_MAX] = {
1509         [IPCTNL_MSG_CT_NEW]             = { .call = ctnetlink_new_conntrack,
1510                                             .attr_count = CTA_MAX, },
1511         [IPCTNL_MSG_CT_GET]             = { .call = ctnetlink_get_conntrack,
1512                                             .attr_count = CTA_MAX, },
1513         [IPCTNL_MSG_CT_DELETE]          = { .call = ctnetlink_del_conntrack,
1514                                             .attr_count = CTA_MAX, },
1515         [IPCTNL_MSG_CT_GET_CTRZERO]     = { .call = ctnetlink_get_conntrack,
1516                                             .attr_count = CTA_MAX, },
1517 };
1518
1519 static struct nfnl_callback ctnl_exp_cb[IPCTNL_MSG_EXP_MAX] = {
1520         [IPCTNL_MSG_EXP_GET]            = { .call = ctnetlink_get_expect,
1521                                             .attr_count = CTA_EXPECT_MAX, },
1522         [IPCTNL_MSG_EXP_NEW]            = { .call = ctnetlink_new_expect,
1523                                             .attr_count = CTA_EXPECT_MAX, },
1524         [IPCTNL_MSG_EXP_DELETE]         = { .call = ctnetlink_del_expect,
1525                                             .attr_count = CTA_EXPECT_MAX, },
1526 };
1527
1528 static struct nfnetlink_subsystem ctnl_subsys = {
1529         .name                           = "conntrack",
1530         .subsys_id                      = NFNL_SUBSYS_CTNETLINK,
1531         .cb_count                       = IPCTNL_MSG_MAX,
1532         .cb                             = ctnl_cb,
1533 };
1534
1535 static struct nfnetlink_subsystem ctnl_exp_subsys = {
1536         .name                           = "conntrack_expect",
1537         .subsys_id                      = NFNL_SUBSYS_CTNETLINK_EXP,
1538         .cb_count                       = IPCTNL_MSG_EXP_MAX,
1539         .cb                             = ctnl_exp_cb,
1540 };
1541
1542 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK);
1543 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_EXP);
1544
1545 static int __init ctnetlink_init(void)
1546 {
1547         int ret;
1548
1549         printk("ctnetlink v%s: registering with nfnetlink.\n", version);
1550         ret = nfnetlink_subsys_register(&ctnl_subsys);
1551         if (ret < 0) {
1552                 printk("ctnetlink_init: cannot register with nfnetlink.\n");
1553                 goto err_out;
1554         }
1555
1556         ret = nfnetlink_subsys_register(&ctnl_exp_subsys);
1557         if (ret < 0) {
1558                 printk("ctnetlink_init: cannot register exp with nfnetlink.\n");
1559                 goto err_unreg_subsys;
1560         }
1561
1562 #ifdef CONFIG_NF_CONNTRACK_EVENTS
1563         ret = nf_conntrack_register_notifier(&ctnl_notifier);
1564         if (ret < 0) {
1565                 printk("ctnetlink_init: cannot register notifier.\n");
1566                 goto err_unreg_exp_subsys;
1567         }
1568
1569         ret = nf_conntrack_expect_register_notifier(&ctnl_notifier_exp);
1570         if (ret < 0) {
1571                 printk("ctnetlink_init: cannot expect register notifier.\n");
1572                 goto err_unreg_notifier;
1573         }
1574 #endif
1575
1576         return 0;
1577
1578 #ifdef CONFIG_NF_CONNTRACK_EVENTS
1579 err_unreg_notifier:
1580         nf_conntrack_unregister_notifier(&ctnl_notifier);
1581 err_unreg_exp_subsys:
1582         nfnetlink_subsys_unregister(&ctnl_exp_subsys);
1583 #endif
1584 err_unreg_subsys:
1585         nfnetlink_subsys_unregister(&ctnl_subsys);
1586 err_out:
1587         return ret;
1588 }
1589
1590 static void __exit ctnetlink_exit(void)
1591 {
1592         printk("ctnetlink: unregistering from nfnetlink.\n");
1593
1594 #ifdef CONFIG_NF_CONNTRACK_EVENTS
1595         nf_conntrack_expect_unregister_notifier(&ctnl_notifier_exp);
1596         nf_conntrack_unregister_notifier(&ctnl_notifier);
1597 #endif
1598
1599         nfnetlink_subsys_unregister(&ctnl_exp_subsys);
1600         nfnetlink_subsys_unregister(&ctnl_subsys);
1601         return;
1602 }
1603
1604 module_init(ctnetlink_init);
1605 module_exit(ctnetlink_exit);