net/ipv4/tcp_diag.c

   1 /*
   2  * tcp_diag.c   Module for monitoring TCP sockets.
   3  *
   4  * Version:     $Id: tcp_diag.c,v 1.3 2002/02/01 22:01:04 davem Exp $
   5  *
   6  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #include <linux/config.h>
  15 #include <linux/module.h>
  16 #include <linux/types.h>
  17 #include <linux/fcntl.h>
  18 #include <linux/random.h>
  19 #include <linux/cache.h>
  20 #include <linux/init.h>
  21 #include <linux/time.h>
  22
  23 #include <net/icmp.h>
  24 #include <net/tcp.h>
  25 #include <net/ipv6.h>
  26 #include <net/inet_common.h>
  27
  28 #include <linux/inet.h>
  29 #include <linux/stddef.h>
  30
  31 #include <linux/tcp_diag.h>
  32
  33 struct tcpdiag_entry
  34 {
  35         u32 *saddr;
  36         u32 *daddr;
  37         u16 sport;
  38         u16 dport;
  39         u16 family;
  40         u16 userlocks;
  41 };
  42
  43 static struct sock *tcpnl;
  44
  45 #define TCPDIAG_PUT(skb, attrtype, attrlen) \
  46         RTA_DATA(__RTA_PUT(skb, attrtype, attrlen))
  47
  48 static int tcpdiag_fill(struct sk_buff *skb, struct sock *sk,
  49                         int ext, u32 pid, u32 seq, u16 nlmsg_flags)
  50 {
  51         const struct inet_sock *inet = inet_sk(sk);
  52         struct tcp_sock *tp = tcp_sk(sk);
  53         const struct inet_connection_sock *icsk = inet_csk(sk);
  54         struct tcpdiagmsg *r;
  55         struct nlmsghdr  *nlh;
  56         struct tcp_info  *info = NULL;
  57         struct tcpdiag_meminfo  *minfo = NULL;
  58         unsigned char    *b = skb->tail;
  59
  60         nlh = NLMSG_PUT(skb, pid, seq, TCPDIAG_GETSOCK, sizeof(*r));
  61         nlh->nlmsg_flags = nlmsg_flags;
  62         r = NLMSG_DATA(nlh);
  63         if (sk->sk_state != TCP_TIME_WAIT) {
  64                 if (ext & (1<<(TCPDIAG_MEMINFO-1)))
  65                         minfo = TCPDIAG_PUT(skb, TCPDIAG_MEMINFO, sizeof(*minfo));
  66                 if (ext & (1<<(TCPDIAG_INFO-1)))
  67                         info = TCPDIAG_PUT(skb, TCPDIAG_INFO, sizeof(*info));
  68
  69                 if (ext & (1<<(TCPDIAG_CONG-1))) {
  70                         size_t len = strlen(tp->ca_ops->name);
  71                         strcpy(TCPDIAG_PUT(skb, TCPDIAG_CONG, len+1),
  72                                tp->ca_ops->name);
  73                 }
  74         }
  75         r->tcpdiag_family = sk->sk_family;
  76         r->tcpdiag_state = sk->sk_state;
  77         r->tcpdiag_timer = 0;
  78         r->tcpdiag_retrans = 0;
  79
  80         r->id.tcpdiag_if = sk->sk_bound_dev_if;
  81         r->id.tcpdiag_cookie[0] = (u32)(unsigned long)sk;
  82         r->id.tcpdiag_cookie[1] = (u32)(((unsigned long)sk >> 31) >> 1);
  83
  84         if (r->tcpdiag_state == TCP_TIME_WAIT) {
  85                 const struct inet_timewait_sock *tw = inet_twsk(sk);
  86                 long tmo = tw->tw_ttd - jiffies;
  87                 if (tmo < 0)
  88                         tmo = 0;
  89
  90                 r->id.tcpdiag_sport = tw->tw_sport;
  91                 r->id.tcpdiag_dport = tw->tw_dport;
  92                 r->id.tcpdiag_src[0] = tw->tw_rcv_saddr;
  93                 r->id.tcpdiag_dst[0] = tw->tw_daddr;
  94                 r->tcpdiag_state = tw->tw_substate;
  95                 r->tcpdiag_timer = 3;
  96                 r->tcpdiag_expires = (tmo*1000+HZ-1)/HZ;
  97                 r->tcpdiag_rqueue = 0;
  98                 r->tcpdiag_wqueue = 0;
  99                 r->tcpdiag_uid = 0;
 100                 r->tcpdiag_inode = 0;
 101 #ifdef CONFIG_IP_TCPDIAG_IPV6
 102                 if (r->tcpdiag_family == AF_INET6) {
 103                         const struct tcp6_timewait_sock *tcp6tw = tcp6_twsk(sk);
 104
 105                         ipv6_addr_copy((struct in6_addr *)r->id.tcpdiag_src,
 106                                        &tcp6tw->tw_v6_rcv_saddr);
 107                         ipv6_addr_copy((struct in6_addr *)r->id.tcpdiag_dst,
 108                                        &tcp6tw->tw_v6_daddr);
 109                 }
 110 #endif
 111                 nlh->nlmsg_len = skb->tail - b;
 112                 return skb->len;
 113         }
 114
 115         r->id.tcpdiag_sport = inet->sport;
 116         r->id.tcpdiag_dport = inet->dport;
 117         r->id.tcpdiag_src[0] = inet->rcv_saddr;
 118         r->id.tcpdiag_dst[0] = inet->daddr;
 119
 120 #ifdef CONFIG_IP_TCPDIAG_IPV6
 121         if (r->tcpdiag_family == AF_INET6) {
 122                 struct ipv6_pinfo *np = inet6_sk(sk);
 123
 124                 ipv6_addr_copy((struct in6_addr *)r->id.tcpdiag_src,
 125                                &np->rcv_saddr);
 126                 ipv6_addr_copy((struct in6_addr *)r->id.tcpdiag_dst,
 127                                &np->daddr);
 128         }
 129 #endif
 130
 131 #define EXPIRES_IN_MS(tmo)  ((tmo-jiffies)*1000+HZ-1)/HZ
 132
 133         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
 134                 r->tcpdiag_timer = 1;
 135                 r->tcpdiag_retrans = icsk->icsk_retransmits;
 136                 r->tcpdiag_expires = EXPIRES_IN_MS(icsk->icsk_timeout);
 137         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
 138                 r->tcpdiag_timer = 4;
 139                 r->tcpdiag_retrans = tp->probes_out;
 140                 r->tcpdiag_expires = EXPIRES_IN_MS(icsk->icsk_timeout);
 141         } else if (timer_pending(&sk->sk_timer)) {
 142                 r->tcpdiag_timer = 2;
 143                 r->tcpdiag_retrans = tp->probes_out;
 144                 r->tcpdiag_expires = EXPIRES_IN_MS(sk->sk_timer.expires);
 145         } else {
 146                 r->tcpdiag_timer = 0;
 147                 r->tcpdiag_expires = 0;
 148         }
 149 #undef EXPIRES_IN_MS
 150
 151         r->tcpdiag_rqueue = tp->rcv_nxt - tp->copied_seq;
 152         r->tcpdiag_wqueue = tp->write_seq - tp->snd_una;
 153         r->tcpdiag_uid = sock_i_uid(sk);
 154         r->tcpdiag_inode = sock_i_ino(sk);
 155
 156         if (minfo) {
 157                 minfo->tcpdiag_rmem = atomic_read(&sk->sk_rmem_alloc);
 158                 minfo->tcpdiag_wmem = sk->sk_wmem_queued;
 159                 minfo->tcpdiag_fmem = sk->sk_forward_alloc;
 160                 minfo->tcpdiag_tmem = atomic_read(&sk->sk_wmem_alloc);
 161         }
 162
 163         if (info)
 164                 tcp_get_info(sk, info);
 165
 166         if (sk->sk_state < TCP_TIME_WAIT && tp->ca_ops->get_info)
 167                 tp->ca_ops->get_info(tp, ext, skb);
 168
 169         nlh->nlmsg_len = skb->tail - b;
 170         return skb->len;
 171
 172 rtattr_failure:
 173 nlmsg_failure:
 174         skb_trim(skb, b - skb->data);
 175         return -1;
 176 }
 177
 178 #ifdef CONFIG_IP_TCPDIAG_IPV6
 179 extern struct sock *tcp_v6_lookup(struct in6_addr *saddr, u16 sport,
 180                                   struct in6_addr *daddr, u16 dport,
 181                                   int dif);
 182 #else
 183 static inline struct sock *tcp_v6_lookup(struct in6_addr *saddr, u16 sport,
 184                                          struct in6_addr *daddr, u16 dport,
 185                                          int dif)
 186 {
 187         return NULL;
 188 }
 189 #endif
 190
 191 static int tcpdiag_get_exact(struct sk_buff *in_skb, const struct nlmsghdr *nlh)
 192 {
 193         int err;
 194         struct sock *sk;
 195         struct tcpdiagreq *req = NLMSG_DATA(nlh);
 196         struct sk_buff *rep;
 197
 198         if (req->tcpdiag_family == AF_INET) {
 199                 sk = inet_lookup(&tcp_hashinfo, req->id.tcpdiag_dst[0],
 200                                  req->id.tcpdiag_dport, req->id.tcpdiag_src[0],
 201                                  req->id.tcpdiag_sport, req->id.tcpdiag_if);
 202         }
 203 #ifdef CONFIG_IP_TCPDIAG_IPV6
 204         else if (req->tcpdiag_family == AF_INET6) {
 205                 sk = tcp_v6_lookup((struct in6_addr*)req->id.tcpdiag_dst, req->id.tcpdiag_dport,
 206                                    (struct in6_addr*)req->id.tcpdiag_src, req->id.tcpdiag_sport,
 207                                    req->id.tcpdiag_if);
 208         }
 209 #endif
 210         else {
 211                 return -EINVAL;
 212         }
 213
 214         if (sk == NULL)
 215                 return -ENOENT;
 216
 217         err = -ESTALE;
 218         if ((req->id.tcpdiag_cookie[0] != TCPDIAG_NOCOOKIE ||
 219              req->id.tcpdiag_cookie[1] != TCPDIAG_NOCOOKIE) &&
 220             ((u32)(unsigned long)sk != req->id.tcpdiag_cookie[0] ||
 221              (u32)((((unsigned long)sk) >> 31) >> 1) != req->id.tcpdiag_cookie[1]))
 222                 goto out;
 223
 224         err = -ENOMEM;
 225         rep = alloc_skb(NLMSG_SPACE(sizeof(struct tcpdiagmsg)+
 226                                     sizeof(struct tcpdiag_meminfo)+
 227                                     sizeof(struct tcp_info)+64), GFP_KERNEL);
 228         if (!rep)
 229                 goto out;
 230
 231         if (tcpdiag_fill(rep, sk, req->tcpdiag_ext,
 232                          NETLINK_CB(in_skb).pid,
 233                          nlh->nlmsg_seq, 0) <= 0)
 234                 BUG();
 235
 236         err = netlink_unicast(tcpnl, rep, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
 237         if (err > 0)
 238                 err = 0;
 239
 240 out:
 241         if (sk) {
 242                 if (sk->sk_state == TCP_TIME_WAIT)
 243                         inet_twsk_put((struct inet_timewait_sock *)sk);
 244                 else
 245                         sock_put(sk);
 246         }
 247         return err;
 248 }
 249
 250 static int bitstring_match(const u32 *a1, const u32 *a2, int bits)
 251 {
 252         int words = bits >> 5;
 253
 254         bits &= 0x1f;
 255
 256         if (words) {
 257                 if (memcmp(a1, a2, words << 2))
 258                         return 0;
 259         }
 260         if (bits) {
 261                 __u32 w1, w2;
 262                 __u32 mask;
 263
 264                 w1 = a1[words];
 265                 w2 = a2[words];
 266
 267                 mask = htonl((0xffffffff) << (32 - bits));
 268
 269                 if ((w1 ^ w2) & mask)
 270                         return 0;
 271         }
 272
 273         return 1;
 274 }
 275
 276
 277 static int tcpdiag_bc_run(const void *bc, int len,
 278                           const struct tcpdiag_entry *entry)
 279 {
 280         while (len > 0) {
 281                 int yes = 1;
 282                 const struct tcpdiag_bc_op *op = bc;
 283
 284                 switch (op->code) {
 285                 case TCPDIAG_BC_NOP:
 286                         break;
 287                 case TCPDIAG_BC_JMP:
 288                         yes = 0;
 289                         break;
 290                 case TCPDIAG_BC_S_GE:
 291                         yes = entry->sport >= op[1].no;
 292                         break;
 293                 case TCPDIAG_BC_S_LE:
 294                         yes = entry->dport <= op[1].no;
 295                         break;
 296                 case TCPDIAG_BC_D_GE:
 297                         yes = entry->dport >= op[1].no;
 298                         break;
 299                 case TCPDIAG_BC_D_LE:
 300                         yes = entry->dport <= op[1].no;
 301                         break;
 302                 case TCPDIAG_BC_AUTO:
 303                         yes = !(entry->userlocks & SOCK_BINDPORT_LOCK);
 304                         break;
 305                 case TCPDIAG_BC_S_COND:
 306                 case TCPDIAG_BC_D_COND:
 307                 {
 308                         struct tcpdiag_hostcond *cond = (struct tcpdiag_hostcond*)(op+1);
 309                         u32 *addr;
 310
 311                         if (cond->port != -1 &&
 312                             cond->port != (op->code == TCPDIAG_BC_S_COND ?
 313                                              entry->sport : entry->dport)) {
 314                                 yes = 0;
 315                                 break;
 316                         }
 317
 318                         if (cond->prefix_len == 0)
 319                                 break;
 320
 321                         if (op->code == TCPDIAG_BC_S_COND)
 322                                 addr = entry->saddr;
 323                         else
 324                                 addr = entry->daddr;
 325
 326                         if (bitstring_match(addr, cond->addr, cond->prefix_len))
 327                                 break;
 328                         if (entry->family == AF_INET6 &&
 329                             cond->family == AF_INET) {
 330                                 if (addr[0] == 0 && addr[1] == 0 &&
 331                                     addr[2] == htonl(0xffff) &&
 332                                     bitstring_match(addr+3, cond->addr, cond->prefix_len))
 333                                         break;
 334                         }
 335                         yes = 0;
 336                         break;
 337                 }
 338                 }
 339
 340                 if (yes) {
 341                         len -= op->yes;
 342                         bc += op->yes;
 343                 } else {
 344                         len -= op->no;
 345                         bc += op->no;
 346                 }
 347         }
 348         return (len == 0);
 349 }
 350
 351 static int valid_cc(const void *bc, int len, int cc)
 352 {
 353         while (len >= 0) {
 354                 const struct tcpdiag_bc_op *op = bc;
 355
 356                 if (cc > len)
 357                         return 0;
 358                 if (cc == len)
 359                         return 1;
 360                 if (op->yes < 4)
 361                         return 0;
 362                 len -= op->yes;
 363                 bc  += op->yes;
 364         }
 365         return 0;
 366 }
 367
 368 static int tcpdiag_bc_audit(const void *bytecode, int bytecode_len)
 369 {
 370         const unsigned char *bc = bytecode;
 371         int  len = bytecode_len;
 372
 373         while (len > 0) {
 374                 struct tcpdiag_bc_op *op = (struct tcpdiag_bc_op*)bc;
 375
 376 //printk("BC: %d %d %d {%d} / %d\n", op->code, op->yes, op->no, op[1].no, len);
 377                 switch (op->code) {
 378                 case TCPDIAG_BC_AUTO:
 379                 case TCPDIAG_BC_S_COND:
 380                 case TCPDIAG_BC_D_COND:
 381                 case TCPDIAG_BC_S_GE:
 382                 case TCPDIAG_BC_S_LE:
 383                 case TCPDIAG_BC_D_GE:
 384                 case TCPDIAG_BC_D_LE:
 385                         if (op->yes < 4 || op->yes > len+4)
 386                                 return -EINVAL;
 387                 case TCPDIAG_BC_JMP:
 388                         if (op->no < 4 || op->no > len+4)
 389                                 return -EINVAL;
 390                         if (op->no < len &&
 391                             !valid_cc(bytecode, bytecode_len, len-op->no))
 392                                 return -EINVAL;
 393                         break;
 394                 case TCPDIAG_BC_NOP:
 395                         if (op->yes < 4 || op->yes > len+4)
 396                                 return -EINVAL;
 397                         break;
 398                 default:
 399                         return -EINVAL;
 400                 }
 401                 bc += op->yes;
 402                 len -= op->yes;
 403         }
 404         return len == 0 ? 0 : -EINVAL;
 405 }
 406
 407 static int tcpdiag_dump_sock(struct sk_buff *skb, struct sock *sk,
 408                              struct netlink_callback *cb)
 409 {
 410         struct tcpdiagreq *r = NLMSG_DATA(cb->nlh);
 411
 412         if (cb->nlh->nlmsg_len > 4 + NLMSG_SPACE(sizeof(*r))) {
 413                 struct tcpdiag_entry entry;
 414                 struct rtattr *bc = (struct rtattr *)(r + 1);
 415                 struct inet_sock *inet = inet_sk(sk);
 416
 417                 entry.family = sk->sk_family;
 418 #ifdef CONFIG_IP_TCPDIAG_IPV6
 419                 if (entry.family == AF_INET6) {
 420                         struct ipv6_pinfo *np = inet6_sk(sk);
 421
 422                         entry.saddr = np->rcv_saddr.s6_addr32;
 423                         entry.daddr = np->daddr.s6_addr32;
 424                 } else
 425 #endif
 426                 {
 427                         entry.saddr = &inet->rcv_saddr;
 428                         entry.daddr = &inet->daddr;
 429                 }
 430                 entry.sport = inet->num;
 431                 entry.dport = ntohs(inet->dport);
 432                 entry.userlocks = sk->sk_userlocks;
 433
 434                 if (!tcpdiag_bc_run(RTA_DATA(bc), RTA_PAYLOAD(bc), &entry))
 435                         return 0;
 436         }
 437
 438         return tcpdiag_fill(skb, sk, r->tcpdiag_ext, NETLINK_CB(cb->skb).pid,
 439                             cb->nlh->nlmsg_seq, NLM_F_MULTI);
 440 }
 441
 442 static int tcpdiag_fill_req(struct sk_buff *skb, struct sock *sk,
 443                             struct request_sock *req,
 444                             u32 pid, u32 seq)
 445 {
 446         const struct inet_request_sock *ireq = inet_rsk(req);
 447         struct inet_sock *inet = inet_sk(sk);
 448         unsigned char *b = skb->tail;
 449         struct tcpdiagmsg *r;
 450         struct nlmsghdr *nlh;
 451         long tmo;
 452
 453         nlh = NLMSG_PUT(skb, pid, seq, TCPDIAG_GETSOCK, sizeof(*r));
 454         nlh->nlmsg_flags = NLM_F_MULTI;
 455         r = NLMSG_DATA(nlh);
 456
 457         r->tcpdiag_family = sk->sk_family;
 458         r->tcpdiag_state = TCP_SYN_RECV;
 459         r->tcpdiag_timer = 1;
 460         r->tcpdiag_retrans = req->retrans;
 461
 462         r->id.tcpdiag_if = sk->sk_bound_dev_if;
 463         r->id.tcpdiag_cookie[0] = (u32)(unsigned long)req;
 464         r->id.tcpdiag_cookie[1] = (u32)(((unsigned long)req >> 31) >> 1);
 465
 466         tmo = req->expires - jiffies;
 467         if (tmo < 0)
 468                 tmo = 0;
 469
 470         r->id.tcpdiag_sport = inet->sport;
 471         r->id.tcpdiag_dport = ireq->rmt_port;
 472         r->id.tcpdiag_src[0] = ireq->loc_addr;
 473         r->id.tcpdiag_dst[0] = ireq->rmt_addr;
 474         r->tcpdiag_expires = jiffies_to_msecs(tmo),
 475         r->tcpdiag_rqueue = 0;
 476         r->tcpdiag_wqueue = 0;
 477         r->tcpdiag_uid = sock_i_uid(sk);
 478         r->tcpdiag_inode = 0;
 479 #ifdef CONFIG_IP_TCPDIAG_IPV6
 480         if (r->tcpdiag_family == AF_INET6) {
 481                 ipv6_addr_copy((struct in6_addr *)r->id.tcpdiag_src,
 482                                &tcp6_rsk(req)->loc_addr);
 483                 ipv6_addr_copy((struct in6_addr *)r->id.tcpdiag_dst,
 484                                &tcp6_rsk(req)->rmt_addr);
 485         }
 486 #endif
 487         nlh->nlmsg_len = skb->tail - b;
 488
 489         return skb->len;
 490
 491 nlmsg_failure:
 492         skb_trim(skb, b - skb->data);
 493         return -1;
 494 }
 495
 496 static int tcpdiag_dump_reqs(struct sk_buff *skb, struct sock *sk,
 497                              struct netlink_callback *cb)
 498 {
 499         struct tcpdiag_entry entry;
 500         struct tcpdiagreq *r = NLMSG_DATA(cb->nlh);
 501         struct inet_connection_sock *icsk = inet_csk(sk);
 502         struct listen_sock *lopt;
 503         struct rtattr *bc = NULL;
 504         struct inet_sock *inet = inet_sk(sk);
 505         int j, s_j;
 506         int reqnum, s_reqnum;
 507         int err = 0;
 508
 509         s_j = cb->args[3];
 510         s_reqnum = cb->args[4];
 511
 512         if (s_j > 0)
 513                 s_j--;
 514
 515         entry.family = sk->sk_family;
 516
 517         read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
 518
 519         lopt = icsk->icsk_accept_queue.listen_opt;
 520         if (!lopt || !lopt->qlen)
 521                 goto out;
 522
 523         if (cb->nlh->nlmsg_len > 4 + NLMSG_SPACE(sizeof(*r))) {
 524                 bc = (struct rtattr *)(r + 1);
 525                 entry.sport = inet->num;
 526                 entry.userlocks = sk->sk_userlocks;
 527         }
 528
 529         for (j = s_j; j < TCP_SYNQ_HSIZE; j++) {
 530                 struct request_sock *req, *head = lopt->syn_table[j];
 531
 532                 reqnum = 0;
 533                 for (req = head; req; reqnum++, req = req->dl_next) {
 534                         struct inet_request_sock *ireq = inet_rsk(req);
 535
 536                         if (reqnum < s_reqnum)
 537                                 continue;
 538                         if (r->id.tcpdiag_dport != ireq->rmt_port &&
 539                             r->id.tcpdiag_dport)
 540                                 continue;
 541
 542                         if (bc) {
 543                                 entry.saddr =
 544 #ifdef CONFIG_IP_TCPDIAG_IPV6
 545                                         (entry.family == AF_INET6) ?
 546                                         tcp6_rsk(req)->loc_addr.s6_addr32 :
 547 #endif
 548                                         &ireq->loc_addr;
 549                                 entry.daddr =
 550 #ifdef CONFIG_IP_TCPDIAG_IPV6
 551                                         (entry.family == AF_INET6) ?
 552                                         tcp6_rsk(req)->rmt_addr.s6_addr32 :
 553 #endif
 554                                         &ireq->rmt_addr;
 555                                 entry.dport = ntohs(ireq->rmt_port);
 556
 557                                 if (!tcpdiag_bc_run(RTA_DATA(bc),
 558                                                     RTA_PAYLOAD(bc), &entry))
 559                                         continue;
 560                         }
 561
 562                         err = tcpdiag_fill_req(skb, sk, req,
 563                                                NETLINK_CB(cb->skb).pid,
 564                                                cb->nlh->nlmsg_seq);
 565                         if (err < 0) {
 566                                 cb->args[3] = j + 1;
 567                                 cb->args[4] = reqnum;
 568                                 goto out;
 569                         }
 570                 }
 571
 572                 s_reqnum = 0;
 573         }
 574
 575 out:
 576         read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
 577
 578         return err;
 579 }
 580
 581 static int tcpdiag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 582 {
 583         int i, num;
 584         int s_i, s_num;
 585         struct tcpdiagreq *r = NLMSG_DATA(cb->nlh);
 586
 587         s_i = cb->args[1];
 588         s_num = num = cb->args[2];
 589
 590         if (cb->args[0] == 0) {
 591                 if (!(r->tcpdiag_states&(TCPF_LISTEN|TCPF_SYN_RECV)))
 592                         goto skip_listen_ht;
 593                 inet_listen_lock(&tcp_hashinfo);
 594                 for (i = s_i; i < INET_LHTABLE_SIZE; i++) {
 595                         struct sock *sk;
 596                         struct hlist_node *node;
 597
 598                         num = 0;
 599                         sk_for_each(sk, node, &tcp_hashinfo.listening_hash[i]) {
 600                                 struct inet_sock *inet = inet_sk(sk);
 601
 602                                 if (num < s_num) {
 603                                         num++;
 604                                         continue;
 605                                 }
 606
 607                                 if (r->id.tcpdiag_sport != inet->sport &&
 608                                     r->id.tcpdiag_sport)
 609                                         goto next_listen;
 610
 611                                 if (!(r->tcpdiag_states&TCPF_LISTEN) ||
 612                                     r->id.tcpdiag_dport ||
 613                                     cb->args[3] > 0)
 614                                         goto syn_recv;
 615
 616                                 if (tcpdiag_dump_sock(skb, sk, cb) < 0) {
 617                                         inet_listen_unlock(&tcp_hashinfo);
 618                                         goto done;
 619                                 }
 620
 621 syn_recv:
 622                                 if (!(r->tcpdiag_states&TCPF_SYN_RECV))
 623                                         goto next_listen;
 624
 625                                 if (tcpdiag_dump_reqs(skb, sk, cb) < 0) {
 626                                         inet_listen_unlock(&tcp_hashinfo);
 627                                         goto done;
 628                                 }
 629
 630 next_listen:
 631                                 cb->args[3] = 0;
 632                                 cb->args[4] = 0;
 633                                 ++num;
 634                         }
 635
 636                         s_num = 0;
 637                         cb->args[3] = 0;
 638                         cb->args[4] = 0;
 639                 }
 640                 inet_listen_unlock(&tcp_hashinfo);
 641 skip_listen_ht:
 642                 cb->args[0] = 1;
 643                 s_i = num = s_num = 0;
 644         }
 645
 646         if (!(r->tcpdiag_states&~(TCPF_LISTEN|TCPF_SYN_RECV)))
 647                 return skb->len;
 648
 649         for (i = s_i; i < tcp_hashinfo.ehash_size; i++) {
 650                 struct inet_ehash_bucket *head = &tcp_hashinfo.ehash[i];
 651                 struct sock *sk;
 652                 struct hlist_node *node;
 653
 654                 if (i > s_i)
 655                         s_num = 0;
 656
 657                 read_lock_bh(&head->lock);
 658
 659                 num = 0;
 660                 sk_for_each(sk, node, &head->chain) {
 661                         struct inet_sock *inet = inet_sk(sk);
 662
 663                         if (num < s_num)
 664                                 goto next_normal;
 665                         if (!(r->tcpdiag_states & (1 << sk->sk_state)))
 666                                 goto next_normal;
 667                         if (r->id.tcpdiag_sport != inet->sport &&
 668                             r->id.tcpdiag_sport)
 669                                 goto next_normal;
 670                         if (r->id.tcpdiag_dport != inet->dport && r->id.tcpdiag_dport)
 671                                 goto next_normal;
 672                         if (tcpdiag_dump_sock(skb, sk, cb) < 0) {
 673                                 read_unlock_bh(&head->lock);
 674                                 goto done;
 675                         }
 676 next_normal:
 677                         ++num;
 678                 }
 679
 680                 if (r->tcpdiag_states&TCPF_TIME_WAIT) {
 681                         sk_for_each(sk, node,
 682                                     &tcp_hashinfo.ehash[i + tcp_hashinfo.ehash_size].chain) {
 683                                 struct inet_sock *inet = inet_sk(sk);
 684
 685                                 if (num < s_num)
 686                                         goto next_dying;
 687                                 if (r->id.tcpdiag_sport != inet->sport &&
 688                                     r->id.tcpdiag_sport)
 689                                         goto next_dying;
 690                                 if (r->id.tcpdiag_dport != inet->dport &&
 691                                     r->id.tcpdiag_dport)
 692                                         goto next_dying;
 693                                 if (tcpdiag_dump_sock(skb, sk, cb) < 0) {
 694                                         read_unlock_bh(&head->lock);
 695                                         goto done;
 696                                 }
 697 next_dying:
 698                                 ++num;
 699                         }
 700                 }
 701                 read_unlock_bh(&head->lock);
 702         }
 703
 704 done:
 705         cb->args[1] = i;
 706         cb->args[2] = num;
 707         return skb->len;
 708 }
 709
 710 static int tcpdiag_dump_done(struct netlink_callback *cb)
 711 {
 712         return 0;
 713 }
 714
 715
 716 static __inline__ int
 717 tcpdiag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 718 {
 719         if (!(nlh->nlmsg_flags&NLM_F_REQUEST))
 720                 return 0;
 721
 722         if (nlh->nlmsg_type != TCPDIAG_GETSOCK)
 723                 goto err_inval;
 724
 725         if (NLMSG_LENGTH(sizeof(struct tcpdiagreq)) > skb->len)
 726                 goto err_inval;
 727
 728         if (nlh->nlmsg_flags&NLM_F_DUMP) {
 729                 if (nlh->nlmsg_len > 4 + NLMSG_SPACE(sizeof(struct tcpdiagreq))) {
 730                         struct rtattr *rta = (struct rtattr*)(NLMSG_DATA(nlh) + sizeof(struct tcpdiagreq));
 731                         if (rta->rta_type != TCPDIAG_REQ_BYTECODE ||
 732                             rta->rta_len < 8 ||
 733                             rta->rta_len > nlh->nlmsg_len - NLMSG_SPACE(sizeof(struct tcpdiagreq)))
 734                                 goto err_inval;
 735                         if (tcpdiag_bc_audit(RTA_DATA(rta), RTA_PAYLOAD(rta)))
 736                                 goto err_inval;
 737                 }
 738                 return netlink_dump_start(tcpnl, skb, nlh,
 739                                           tcpdiag_dump,
 740                                           tcpdiag_dump_done);
 741         } else {
 742                 return tcpdiag_get_exact(skb, nlh);
 743         }
 744
 745 err_inval:
 746         return -EINVAL;
 747 }
 748
 749
 750 static inline void tcpdiag_rcv_skb(struct sk_buff *skb)
 751 {
 752         int err;
 753         struct nlmsghdr * nlh;
 754
 755         if (skb->len >= NLMSG_SPACE(0)) {
 756                 nlh = (struct nlmsghdr *)skb->data;
 757                 if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
 758                         return;
 759                 err = tcpdiag_rcv_msg(skb, nlh);
 760                 if (err || nlh->nlmsg_flags & NLM_F_ACK)
 761                         netlink_ack(skb, nlh, err);
 762         }
 763 }
 764
 765 static void tcpdiag_rcv(struct sock *sk, int len)
 766 {
 767         struct sk_buff *skb;
 768         unsigned int qlen = skb_queue_len(&sk->sk_receive_queue);
 769
 770         while (qlen-- && (skb = skb_dequeue(&sk->sk_receive_queue))) {
 771                 tcpdiag_rcv_skb(skb);
 772                 kfree_skb(skb);
 773         }
 774 }
 775
 776 static int __init tcpdiag_init(void)
 777 {
 778         tcpnl = netlink_kernel_create(NETLINK_TCPDIAG, tcpdiag_rcv,
 779                                       THIS_MODULE);
 780         if (tcpnl == NULL)
 781                 return -ENOMEM;
 782         return 0;
 783 }
 784
 785 static void __exit tcpdiag_exit(void)
 786 {
 787         sock_release(tcpnl->sk_socket);
 788 }
 789
 790 module_init(tcpdiag_init);
 791 module_exit(tcpdiag_exit);
 792 MODULE_LICENSE("GPL");