net/ipv4/netfilter/ipfwadm_core.c

   1 /* Minor modifications to fit on compatibility framework:
   2    Rusty.Russell@rustcorp.com.au
   3 */
   4
   5 #include <linux/config.h>
   6 #define CONFIG_IP_FIREWALL
   7 #define CONFIG_IP_FIREWALL_VERBOSE
   8 #define CONFIG_IP_MASQUERADE
   9 #define CONFIG_IP_ACCT
  10 #define CONFIG_IP_TRANSPARENT_PROXY
  11 #if defined(CONFIG_NETLINK_DEV) || defined(CONFIG_NETLINK_DEV_MODULE)
  12 #define CONFIG_IP_FIREWALL_NETLINK
  13 #endif
  14
  15 /*
  16  *      IP firewalling code. This is taken from 4.4BSD. Please note the
  17  *      copyright message below. As per the GPL it must be maintained
  18  *      and the licenses thus do not conflict. While this port is subject
  19  *      to the GPL I also place my modifications under the original
  20  *      license in recognition of the original copyright.
  21  *                              -- Alan Cox.
  22  *
  23  *      $Id: ipfwadm_core.c,v 1.11 2002/01/24 15:50:31 davem Exp $
  24  *
  25  *      Ported from BSD to Linux,
  26  *              Alan Cox 22/Nov/1994.
  27  *      Zeroing /proc and other additions
  28  *              Jos Vos 4/Feb/1995.
  29  *      Merged and included the FreeBSD-Current changes at Ugen's request
  30  *      (but hey it's a lot cleaner now). Ugen would prefer in some ways
  31  *      we waited for his final product but since Linux 1.2.0 is about to
  32  *      appear it's not practical - Read: It works, it's not clean but please
  33  *      don't consider it to be his standard of finished work.
  34  *              Alan Cox 12/Feb/1995
  35  *      Porting bidirectional entries from BSD, fixing accounting issues,
  36  *      adding struct ip_fwpkt for checking packets with interface address
  37  *              Jos Vos 5/Mar/1995.
  38  *      Established connections (ACK check), ACK check on bidirectional rules,
  39  *      ICMP type check.
  40  *              Wilfred Mollenvanger 7/7/1995.
  41  *      TCP attack protection.
  42  *              Alan Cox 25/8/95, based on information from bugtraq.
  43  *      ICMP type printk, IP_FW_F_APPEND
  44  *              Bernd Eckenfels 1996-01-31
  45  *      Split blocking chain into input and output chains, add new "insert" and
  46  *      "append" commands to replace semi-intelligent "add" command, let "delete".
  47  *      only delete the first matching entry, use 0xFFFF (0xFF) as ports (ICMP
  48  *      types) when counting packets being 2nd and further fragments.
  49  *              Jos Vos <jos@xos.nl> 8/2/1996.
  50  *      Add support for matching on device names.
  51  *              Jos Vos <jos@xos.nl> 15/2/1996.
  52  *      Transparent proxying support.
  53  *              Willy Konynenberg <willy@xos.nl> 10/5/96.
  54  *      Make separate accounting on incoming and outgoing packets possible.
  55  *              Jos Vos <jos@xos.nl> 18/5/1996.
  56  *      Added trap out of bad frames.
  57  *              Alan Cox <alan@cymru.net> 17/11/1996
  58  *
  59  *
  60  * Masquerading functionality
  61  *
  62  * Copyright (c) 1994 Pauline Middelink
  63  *
  64  * The pieces which added masquerading functionality are totally
  65  * my responsibility and have nothing to with the original authors
  66  * copyright or doing.
  67  *
  68  * Parts distributed under GPL.
  69  *
  70  * Fixes:
  71  *      Pauline Middelink       :       Added masquerading.
  72  *      Alan Cox                :       Fixed an error in the merge.
  73  *      Thomas Quinot           :       Fixed port spoofing.
  74  *      Alan Cox                :       Cleaned up retransmits in spoofing.
  75  *      Alan Cox                :       Cleaned up length setting.
  76  *      Wouter Gadeyne          :       Fixed masquerading support of ftp PORT commands
  77  *
  78  *      Juan Jose Ciarlante     :       Masquerading code moved to ip_masq.c
  79  *      Andi Kleen :            Print frag_offsets and the ip flags properly.
  80  *
  81  *      All the real work was done by .....
  82  *
  83  */
  84
  85
  86 /*
  87  * Copyright (c) 1993 Daniel Boulet
  88  * Copyright (c) 1994 Ugen J.S.Antsilevich
  89  *
  90  * Redistribution and use in source forms, with and without modification,
  91  * are permitted provided that this entire comment appears intact.
  92  *
  93  * Redistribution in binary form may occur without any restrictions.
  94  * Obviously, it would be nice if you gave credit where credit is due
  95  * but requiring it would be too onerous.
  96  *
  97  * This software is provided ``AS IS'' without any warranties of any kind.
  98  */
  99
 100 #include <asm/uaccess.h>
 101 #include <asm/system.h>
 102 #include <linux/types.h>
 103 #include <linux/kernel.h>
 104 #include <linux/sched.h>
 105 #include <linux/string.h>
 106 #include <linux/errno.h>
 107 #include <linux/module.h>
 108
 109 #include <linux/socket.h>
 110 #include <linux/sockios.h>
 111 #include <linux/in.h>
 112 #include <linux/inet.h>
 113 #include <linux/netdevice.h>
 114 #include <linux/icmp.h>
 115 #include <linux/udp.h>
 116 #include <net/ip.h>
 117 #include <net/protocol.h>
 118 #include <net/route.h>
 119 #include <net/tcp.h>
 120 #include <net/udp.h>
 121 #include <net/sock.h>
 122 #include <net/icmp.h>
 123 #include <linux/netlink.h>
 124 #include <linux/init.h>
 125 #include <linux/spinlock.h>
 126 #include <linux/netfilter_ipv4/ipfwadm_core.h>
 127 #include <linux/netfilter_ipv4/compat_firewall.h>
 128 #include <linux/netfilter_ipv4/lockhelp.h>
 129 #include <linux/netfilter_ipv4/ip_nat_core.h>
 130
 131 #include <net/checksum.h>
 132 #include <linux/proc_fs.h>
 133 #include <linux/stat.h>
 134
 135 MODULE_LICENSE("Dual BSD/GPL");
 136 MODULE_DESCRIPTION("ipfwadm backwards compatibility layer");
 137
 138 /*
 139  *      Implement IP packet firewall
 140  */
 141
 142 #ifdef DEBUG_IP_FIREWALL
 143 #define dprintf1(a)             printk(a)
 144 #define dprintf2(a1,a2)         printk(a1,a2)
 145 #define dprintf3(a1,a2,a3)      printk(a1,a2,a3)
 146 #define dprintf4(a1,a2,a3,a4)   printk(a1,a2,a3,a4)
 147 #else
 148 #define dprintf1(a)
 149 #define dprintf2(a1,a2)
 150 #define dprintf3(a1,a2,a3)
 151 #define dprintf4(a1,a2,a3,a4)
 152 #endif
 153
 154 #define print_ip(a)      printk("%u.%u.%u.%u", NIPQUAD(a));
 155
 156 #ifdef DEBUG_IP_FIREWALL
 157 #define dprint_ip(a)    print_ip(a)
 158 #else
 159 #define dprint_ip(a)
 160 #endif
 161
 162 static DECLARE_RWLOCK(ip_fw_lock);
 163
 164 #if defined(CONFIG_IP_ACCT) || defined(CONFIG_IP_FIREWALL)
 165
 166 struct ip_fw *ip_fw_fwd_chain;
 167 struct ip_fw *ip_fw_in_chain;
 168 struct ip_fw *ip_fw_out_chain;
 169 struct ip_fw *ip_acct_chain;
 170 struct ip_fw *ip_masq_chain;
 171
 172 static struct ip_fw **chains[] =
 173         {&ip_fw_fwd_chain, &ip_fw_in_chain, &ip_fw_out_chain, &ip_acct_chain,
 174          &ip_masq_chain
 175         };
 176 #endif /* CONFIG_IP_ACCT || CONFIG_IP_FIREWALL */
 177
 178 #ifdef CONFIG_IP_FIREWALL
 179 int ip_fw_fwd_policy=IP_FW_F_ACCEPT;
 180 int ip_fw_in_policy=IP_FW_F_ACCEPT;
 181 int ip_fw_out_policy=IP_FW_F_ACCEPT;
 182
 183 static int *policies[] =
 184         {&ip_fw_fwd_policy, &ip_fw_in_policy, &ip_fw_out_policy};
 185
 186 #endif
 187
 188 #ifdef CONFIG_IP_FIREWALL_NETLINK
 189 struct sock *ipfwsk;
 190 #endif
 191
 192 /*
 193  *      Returns 1 if the port is matched by the vector, 0 otherwise
 194  */
 195
 196 extern inline int port_match(unsigned short *portptr,int nports,unsigned short port,int range_flag)
 197 {
 198         if (!nports)
 199                 return 1;
 200         if ( range_flag )
 201         {
 202                 if ( portptr[0] <= port && port <= portptr[1] )
 203                 {
 204                         return( 1 );
 205                 }
 206                 nports -= 2;
 207                 portptr += 2;
 208         }
 209         while ( nports-- > 0 )
 210         {
 211                 if ( *portptr++ == port )
 212                 {
 213                         return( 1 );
 214                 }
 215         }
 216         return(0);
 217 }
 218
 219 #if defined(CONFIG_IP_ACCT) || defined(CONFIG_IP_FIREWALL)
 220
 221 #ifdef CONFIG_IP_FIREWALL_VERBOSE
 222
 223 /*
 224  *      VERY ugly piece of code which actually makes kernel printf for
 225  *      matching packets.
 226  */
 227
 228 static char *chain_name(struct ip_fw *chain, int mode)
 229 {
 230         switch (mode) {
 231         case IP_FW_MODE_ACCT_IN: return "acct in";
 232         case IP_FW_MODE_ACCT_OUT: return "acct out";
 233         default:
 234                 if (chain == ip_fw_fwd_chain)
 235                         return "fw-fwd";
 236                 else if (chain == ip_fw_in_chain)
 237                         return "fw-in";
 238                 else
 239                         return "fw-out";
 240         }
 241 }
 242
 243 static char *rule_name(struct ip_fw *f, int mode, char *buf)
 244 {
 245         if (mode == IP_FW_MODE_ACCT_IN || mode == IP_FW_MODE_ACCT_OUT)
 246                 return "";
 247
 248         if(f->fw_flg&IP_FW_F_ACCEPT) {
 249                 if(f->fw_flg&IP_FW_F_REDIR) {
 250                         sprintf(buf, "acc/r%d ", f->fw_pts[f->fw_nsp+f->fw_ndp]);
 251                         return buf;
 252                 } else if(f->fw_flg&IP_FW_F_MASQ)
 253                         return "acc/masq ";
 254                 else
 255                         return "acc ";
 256         } else if(f->fw_flg&IP_FW_F_ICMPRPL) {
 257                 return "rej ";
 258         } else {
 259                 return "deny ";
 260         }
 261 }
 262
 263 static void print_packet(struct sk_buff **pskb,
 264                          u16 src_port, u16 dst_port, u16 icmp_type,
 265                          char *chain, char *rule, char *devname)
 266 {
 267         __u32 *opt = (__u32 *) ((*pskb)->nh.iph + 1);
 268         int opti;
 269         __u16 foff = ntohs((*pskb)->nh.iph->frag_off);
 270         int protocol = (*pskb)->nh.iph->protocol;
 271
 272         printk(KERN_INFO "IP %s %s%s", chain, rule, devname);
 273
 274         switch (protocol) {
 275         case IPPROTO_TCP:
 276                 printk(" TCP ");
 277                 break;
 278         case IPPROTO_UDP:
 279                 printk(" UDP ");
 280                 break;
 281         case IPPROTO_ICMP:
 282                 printk(" ICMP/%d ", icmp_type);
 283                 break;
 284         default:
 285                 printk(" PROTO=%d ", protocol);
 286                 break;
 287         };
 288
 289         print_ip((*pskb)->nh.iph->saddr);
 290         if (protocol == IPPROTO_TCP || protocol == IPPROTO_UDP)
 291                 printk(":%hu", src_port);
 292         printk(" ");
 293         print_ip((*pskb)->nh.iph->daddr);
 294         if (protocol == IPPROTO_TCP || protocol == IPPROTO_UDP)
 295                 printk(":%hu", dst_port);
 296         printk(" L=%hu S=0x%2.2hX I=%hu FO=0x%4.4hX T=%hu",
 297                ntohs((*pskb)->nh.iph->tot_len),
 298                (*pskb)->nh.iph->tos,
 299                ntohs((*pskb)->nh.iph->id),
 300                foff & IP_OFFSET,
 301                (*pskb)->nh.iph->ttl);
 302         if (foff & IP_DF)
 303                 printk(" DF=1");
 304         if (foff & IP_MF)
 305                 printk(" MF=1");
 306         for (opti = 0; opti < ((*pskb)->nh.iph->ihl - sizeof(struct iphdr) / 4); opti++)
 307                 printk(" O=0x%8.8X", *opt++);
 308         printk("\n");
 309 }
 310 #endif
 311
 312 /*
 313  *      Returns one of the generic firewall policies, like FW_ACCEPT.
 314  *      Also does accounting so you can feed it the accounting chain.
 315  *
 316  *      The modes is either IP_FW_MODE_FW (normal firewall mode),
 317  *      IP_FW_MODE_ACCT_IN or IP_FW_MODE_ACCT_OUT (accounting mode,
 318  *      steps through the entire chain and handles fragments
 319  *      differently), or IP_FW_MODE_CHK (handles user-level check,
 320  *      counters are not updated).
 321  */
 322
 323
 324 int ip_fw_chk(struct sk_buff **pskb,
 325               struct net_device *rif, __u16 *redirport,
 326               struct ip_fw *chain, int policy, int mode)
 327 {
 328         struct ip_fw *f;
 329         __u32                   src, dst;
 330         __u16                   src_port=0xFFFF, dst_port=0xFFFF, icmp_type=0xFF;
 331         unsigned short          f_prt=0, prt;
 332         char                    notcpsyn=0, notcpack=0, match;
 333         unsigned short          offset;
 334         int                     answer;
 335         unsigned char           tosand, tosxor;
 336         int                     protocol;
 337
 338         /*
 339          *      If the chain is empty follow policy. The BSD one
 340          *      accepts anything giving you a time window while
 341          *      flushing and rebuilding the tables.
 342          */
 343
 344         /*
 345          *      This way we handle fragmented packets.
 346          *      we ignore all fragments but the first one
 347          *      so the whole packet can't be reassembled.
 348          *      This way we relay on the full info which
 349          *      stored only in first packet.
 350          *
 351          *      Note that this theoretically allows partial packet
 352          *      spoofing. Not very dangerous but paranoid people may
 353          *      wish to play with this. It also allows the so called
 354          *      "fragment bomb" denial of service attack on some types
 355          *      of system.
 356          */
 357
 358         offset = ntohs((*pskb)->nh.iph->frag_off) & IP_OFFSET;
 359         protocol = (*pskb)->nh.iph->protocol;
 360
 361         /*
 362          *      Don't allow a fragment of TCP 8 bytes in. Nobody
 363          *      normal causes this. Its a cracker trying to break
 364          *      in by doing a flag overwrite to pass the direction
 365          *      checks.
 366          */
 367
 368         if (offset == 1 && protocol == IPPROTO_TCP)
 369                 return FW_BLOCK;
 370
 371         if (offset!=0 && !(mode & (IP_FW_MODE_ACCT_IN|IP_FW_MODE_ACCT_OUT)) &&
 372                 (protocol == IPPROTO_TCP ||
 373                  protocol == IPPROTO_UDP ||
 374                  protocol == IPPROTO_ICMP))
 375                 return FW_ACCEPT;
 376
 377         /*
 378          *       Header fragment for TCP is too small to check the bits.
 379          */
 380
 381         if (protocol == IPPROTO_TCP &&
 382             ((*pskb)->nh.iph->ihl<<2)+16 > ntohs((*pskb)->nh.iph->tot_len))
 383                 return FW_BLOCK;
 384
 385         /*
 386          *      Too short.
 387          *
 388          *      But only too short for a packet with ports...
 389          */
 390
 391         else if ((ntohs((*pskb)->nh.iph->tot_len) <
 392                   8 + ((*pskb)->nh.iph->ihl << 2)) &&
 393                  (protocol == IPPROTO_TCP || protocol == IPPROTO_UDP))
 394                 return FW_BLOCK;
 395
 396         src = (*pskb)->nh.iph->saddr;
 397         dst = (*pskb)->nh.iph->daddr;
 398
 399         /*
 400          *      If we got interface from which packet came
 401          *      we can use the address directly. This is unlike
 402          *      4.4BSD derived systems that have an address chain
 403          *      per device. We have a device per address with dummy
 404          *      devices instead.
 405          */
 406
 407         dprintf1("Packet ");
 408         switch (protocol) {
 409                 case IPPROTO_TCP:
 410                         dprintf1("TCP ");
 411                         /* ports stay 0xFFFF if it is not the first fragment */
 412                         if (!offset) {
 413                                 struct tcphdr tcph;
 414
 415                                 if (skb_copy_bits(*pskb,
 416                                                   (*pskb)->nh.iph->ihl * 4,
 417                                                   &tcph, sizeof(tcph)))
 418                                         return FW_BLOCK;
 419
 420                                 src_port = ntohs(tcph.source);
 421                                 dst_port = ntohs(tcph.dest);
 422
 423                                 if(!tcph.ack && !tcph.rst)
 424                                         /* We do NOT have ACK, value TRUE */
 425                                         notcpack = 1;
 426                                 if(!tcph.syn || !notcpack)
 427                                         /* We do NOT have SYN, value TRUE */
 428                                         notcpsyn = 1;
 429                         }
 430                         prt = IP_FW_F_TCP;
 431                         break;
 432                 case IPPROTO_UDP:
 433                         dprintf1("UDP ");
 434                         /* ports stay 0xFFFF if it is not the first fragment */
 435                         if (!offset) {
 436                                 struct udphdr udph;
 437
 438                                 if (skb_copy_bits(*pskb,
 439                                                   (*pskb)->nh.iph->ihl * 4,
 440                                                   &udph, sizeof(udph)))
 441                                         return FW_BLOCK;
 442
 443                                 src_port = ntohs(udph.source);
 444                                 dst_port = ntohs(udph.dest);
 445                         }
 446                         prt = IP_FW_F_UDP;
 447                         break;
 448                 case IPPROTO_ICMP:
 449                         /* icmp_type stays 255 if it is not the first fragment */
 450                         if (!offset) {
 451                                 struct icmphdr icmph;
 452
 453                                 if (skb_copy_bits(*pskb,
 454                                                   (*pskb)->nh.iph->ihl * 4,
 455                                                   &icmph, sizeof(icmph)))
 456                                         return FW_BLOCK;
 457
 458                                 icmp_type = (__u16) icmph.type;
 459                         }
 460                         dprintf2("ICMP:%d ", icmp_type);
 461                         prt = IP_FW_F_ICMP;
 462                         break;
 463                 default:
 464                         dprintf2("p=%d ", protocol);
 465                         prt = IP_FW_F_ALL;
 466                         break;
 467         }
 468 #ifdef DEBUG_IP_FIREWALL
 469         dprint_ip(src);
 470
 471         if (protocol == IPPROTO_TCP || protocol == IPPROTO_UDP)
 472                 /* This will print 65535 when it is not the first fragment! */
 473                 dprintf2(":%d ", src_port);
 474         dprint_ip(dst);
 475         if (protocol == IPPROTO_TCP || protocol == IPPROTO_UDP)
 476                 /* This will print 65535 when it is not the first fragment! */
 477                 dprintf2(":%d ", dst_port);
 478         dprintf1("\n");
 479 #endif
 480
 481         if (mode == IP_FW_MODE_CHK)
 482                 READ_LOCK(&ip_fw_lock);
 483         else
 484                 WRITE_LOCK(&ip_fw_lock);
 485
 486         for (f = chain; f; f = f->fw_next) {
 487                 /*
 488                  *      This is a bit simpler as we don't have to walk
 489                  *      an interface chain as you do in BSD - same logic
 490                  *      however.
 491                  */
 492
 493                 /*
 494                  *      Match can become 0x01 (a "normal" match was found),
 495                  *      0x02 (a reverse match was found), and 0x03 (the
 496                  *      IP addresses match in both directions).
 497                  *      Now we know in which direction(s) we should look
 498                  *      for a match for the TCP/UDP ports.  Both directions
 499                  *      might match (e.g., when both addresses are on the
 500                  *      same network for which an address/mask is given), but
 501                  *      the ports might only match in one direction.
 502                  *      This was obviously wrong in the original BSD code.
 503                  */
 504                 match = 0x00;
 505
 506                 if ((src & f->fw_smsk.s_addr) == f->fw_src.s_addr &&
 507                     (dst & f->fw_dmsk.s_addr) == f->fw_dst.s_addr)
 508                         /* normal direction */
 509                         match |= 0x01;
 510
 511                 if ((f->fw_flg & IP_FW_F_BIDIR) &&
 512                     (dst & f->fw_smsk.s_addr) == f->fw_src.s_addr &&
 513                     (src & f->fw_dmsk.s_addr) == f->fw_dst.s_addr)
 514                         /* reverse direction */
 515                         match |= 0x02;
 516
 517                 if (!match)
 518                         continue;
 519
 520                 /*
 521                  *      Look for a VIA device match
 522                  */
 523                 if (f->fw_viadev) {
 524                         if (rif != f->fw_viadev)
 525                                 continue;       /* Mismatch */
 526                 }
 527
 528                 /* This looks stupid, because we scan almost static
 529                    list, searching for static key. However, this way seems
 530                    to be only reasonable way of handling fw_via rules
 531                    (btw bsd makes the same thing).
 532
 533                    It will not affect performance if you will follow
 534                    the following simple rules:
 535
 536                    - if interface is aliased, ALWAYS specify fw_viadev,
 537                      so that previous check will guarantee, that we will
 538                      not waste time when packet arrive on another interface.
 539
 540                    - avoid using fw_via.s_addr if fw_via.s_addr is owned
 541                      by an aliased interface.
 542
 543                                                                        --ANK
 544                  */
 545                 if (f->fw_via.s_addr && rif) {
 546                         struct in_ifaddr *ifa;
 547
 548                         if (rif->ip_ptr == NULL)
 549                                 continue;       /* Mismatch */
 550
 551                         for (ifa = ((struct in_device*)(rif->ip_ptr))->ifa_list;
 552                              ifa; ifa = ifa->ifa_next) {
 553                                 if (ifa->ifa_local == f->fw_via.s_addr)
 554                                         goto ifa_ok;
 555                         }
 556                         continue;       /* Mismatch */
 557
 558                 ifa_ok:;
 559                 }
 560
 561                 /*
 562                  *      Ok the chain addresses match.
 563                  */
 564
 565 #ifdef CONFIG_IP_ACCT
 566                 /*
 567                  *      See if we're in accounting mode and only want to
 568                  *      count incoming or outgoing packets.
 569                  */
 570
 571                 if (mode & (IP_FW_MODE_ACCT_IN|IP_FW_MODE_ACCT_OUT) &&
 572                    ((mode == IP_FW_MODE_ACCT_IN && f->fw_flg&IP_FW_F_ACCTOUT) ||
 573                     (mode == IP_FW_MODE_ACCT_OUT && f->fw_flg&IP_FW_F_ACCTIN)))
 574                         continue;
 575
 576 #endif
 577                 /*
 578                  * For all non-TCP packets and/or non-first fragments,
 579                  * notcpsyn and notcpack will always be FALSE,
 580                  * so the IP_FW_F_TCPSYN and IP_FW_F_TCPACK flags
 581                  * are actually ignored for these packets.
 582                  */
 583
 584                 if((f->fw_flg&IP_FW_F_TCPSYN) && notcpsyn)
 585                         continue;
 586
 587                 if((f->fw_flg&IP_FW_F_TCPACK) && notcpack)
 588                         continue;
 589
 590                 f_prt=f->fw_flg&IP_FW_F_KIND;
 591                 if (f_prt != IP_FW_F_ALL) {
 592                         /*
 593                          *      Specific firewall - packet's protocol
 594                          *      must match firewall's.
 595                          */
 596
 597                         if (prt != f_prt)
 598                                 continue;
 599
 600                         if((prt==IP_FW_F_ICMP &&
 601                                 ! port_match(&f->fw_pts[0], f->fw_nsp,
 602                                         icmp_type,f->fw_flg&IP_FW_F_SRNG)) ||
 603                             !(prt==IP_FW_F_ICMP || ((match & 0x01) &&
 604                                 port_match(&f->fw_pts[0], f->fw_nsp, src_port,
 605                                         f->fw_flg&IP_FW_F_SRNG) &&
 606                                 port_match(&f->fw_pts[f->fw_nsp], f->fw_ndp, dst_port,
 607                                         f->fw_flg&IP_FW_F_DRNG)) || ((match & 0x02) &&
 608                                 port_match(&f->fw_pts[0], f->fw_nsp, dst_port,
 609                                         f->fw_flg&IP_FW_F_SRNG) &&
 610                                 port_match(&f->fw_pts[f->fw_nsp], f->fw_ndp, src_port,
 611                                         f->fw_flg&IP_FW_F_DRNG))))
 612                         {
 613                                 continue;
 614                         }
 615                 }
 616
 617 #ifdef CONFIG_IP_FIREWALL_VERBOSE
 618                 if (f->fw_flg & IP_FW_F_PRN)
 619                 {
 620                         char buf[16];
 621
 622                         print_packet(pskb, src_port, dst_port, icmp_type,
 623                                      chain_name(chain, mode),
 624                                      rule_name(f, mode, buf),
 625                                      rif ? rif->name : "-");
 626                 }
 627 #endif
 628                 if (mode != IP_FW_MODE_CHK) {
 629                         f->fw_bcnt += ntohs((*pskb)->nh.iph->tot_len);
 630                         f->fw_pcnt++;
 631                 }
 632                 if (!(mode & (IP_FW_MODE_ACCT_IN|IP_FW_MODE_ACCT_OUT)))
 633                         break;
 634         } /* Loop */
 635
 636         if (!(mode & (IP_FW_MODE_ACCT_IN|IP_FW_MODE_ACCT_OUT))) {
 637
 638                 /*
 639                  * We rely on policy defined in the rejecting entry or, if no match
 640                  * was found, we rely on the general policy variable for this type
 641                  * of firewall.
 642                  */
 643
 644                 if (f != NULL) {
 645                         policy = f->fw_flg;
 646                         tosand = f->fw_tosand;
 647                         tosxor = f->fw_tosxor;
 648                 } else {
 649                         tosand = 0xFF;
 650                         tosxor = 0x00;
 651                 }
 652
 653                 if (policy & IP_FW_F_ACCEPT) {
 654                         /* Adjust priority and recompute checksum */
 655                         __u8 tos = (*pskb)->nh.iph->tos;
 656
 657                         if (((tos & tosand) ^ tosxor) != tos) {
 658                                 if (!skb_ip_make_writable(pskb,
 659                                           offsetof(struct iphdr, tos)+1))
 660                                         goto drop_it;
 661
 662                                 (*pskb)->nh.iph->tos = (tos & tosand) ^ tosxor;
 663                                 ip_send_check((*pskb)->nh.iph);
 664                         }
 665
 666 #ifdef CONFIG_IP_TRANSPARENT_PROXY
 667                         if (policy & IP_FW_F_REDIR) {
 668                                 if (redirport)
 669                                         if ((*redirport = htons(f->fw_pts[f->fw_nsp+f->fw_ndp])) == 0) {
 670                                                 /* Wildcard redirection.
 671                                                  * Note that redirport will become
 672                                                  * 0xFFFF for non-TCP/UDP packets.
 673                                                  */
 674                                                 *redirport = htons(dst_port);
 675                                         }
 676                                 answer = FW_REDIRECT;
 677                         } else
 678 #endif
 679 #ifdef CONFIG_IP_MASQUERADE
 680                         if (policy & IP_FW_F_MASQ)
 681                                 answer = FW_MASQUERADE;
 682                         else
 683 #endif
 684                                 answer = FW_ACCEPT;
 685
 686                 } else if (policy & IP_FW_F_ICMPRPL)
 687                         answer = FW_REJECT;
 688                 else {
 689                 drop_it:
 690                         answer = FW_BLOCK;
 691                 }
 692
 693 #ifdef CONFIG_IP_FIREWALL_NETLINK
 694                 if ((policy & IP_FW_F_PRN) && (answer == FW_REJECT || answer == FW_BLOCK))
 695                 {
 696                         struct sk_buff *skb = alloc_skb(128,
 697                                         (mode == IP_FW_MODE_CHK) ?
 698                                         GFP_KERNEL : GFP_ATOMIC);
 699                         if (skb) {
 700                                 int len = min_t(unsigned int,
 701                                         128,
 702                                         ntohs((*pskb)->nh.iph->tot_len));
 703
 704                                 skb_put(skb, len);
 705                                 skb_copy_bits(*pskb,
 706                                         ((char *)(*pskb)->nh.iph -
 707                                          (char *)(*pskb)->data),
 708                                         skb->data, len);
 709                                 if (netlink_post(NETLINK_FIREWALL, skb))
 710                                         kfree_skb(skb);
 711                         }
 712                 }
 713 #endif
 714         } else
 715                 /* we're doing accounting, always ok */
 716                 answer = 0;
 717
 718         if (mode == IP_FW_MODE_CHK)
 719                 READ_UNLOCK(&ip_fw_lock);
 720         else
 721                 WRITE_UNLOCK(&ip_fw_lock);
 722
 723         return answer;
 724 }
 725
 726
 727 static void zero_fw_chain(struct ip_fw *chainptr)
 728 {
 729         struct ip_fw *ctmp=chainptr;
 730
 731         WRITE_LOCK(&ip_fw_lock);
 732         while(ctmp)
 733         {
 734                 ctmp->fw_pcnt=0L;
 735                 ctmp->fw_bcnt=0L;
 736                 ctmp=ctmp->fw_next;
 737         }
 738         WRITE_UNLOCK(&ip_fw_lock);
 739 }
 740
 741 static void free_fw_chain(struct ip_fw *volatile* chainptr)
 742 {
 743         WRITE_LOCK(&ip_fw_lock);
 744         while ( *chainptr != NULL )
 745         {
 746                 struct ip_fw *ftmp;
 747                 ftmp = *chainptr;
 748                 *chainptr = ftmp->fw_next;
 749                 if (ftmp->fw_viadev
 750                     && ftmp->fw_viadev != (struct net_device *)-1)
 751                         dev_put(ftmp->fw_viadev);
 752                 kfree(ftmp);
 753                 /* We will block in cleanup's unregister sockopt if unloaded,
 754                    so this is safe. */
 755                 module_put(THIS_MODULE);
 756         }
 757         WRITE_UNLOCK(&ip_fw_lock);
 758 }
 759
 760 /* Volatiles to keep some of the compiler versions amused */
 761
 762 static int insert_in_chain(struct ip_fw *volatile* chainptr, struct ip_fw *frwl,int len)
 763 {
 764         struct ip_fw *ftmp;
 765
 766         /* Are we unloading now?  We will block on nf_unregister_sockopt */
 767         if (!try_module_get(THIS_MODULE))
 768                 return ENOPROTOOPT;
 769
 770         ftmp = kmalloc( sizeof(struct ip_fw), GFP_KERNEL );
 771         if ( ftmp == NULL )
 772         {
 773 #ifdef DEBUG_IP_FIREWALL
 774                 printk("ip_fw_ctl:  malloc said no\n");
 775 #endif
 776                 return( ENOMEM );
 777         }
 778
 779         memcpy(ftmp, frwl, len);
 780         /*
 781          *      Allow the more recent "minimise cost" flag to be
 782          *      set. [Rob van Nieuwkerk]
 783          */
 784         ftmp->fw_tosand |= 0x01;
 785         ftmp->fw_tosxor &= 0xFE;
 786         ftmp->fw_pcnt=0L;
 787         ftmp->fw_bcnt=0L;
 788
 789         WRITE_LOCK(&ip_fw_lock);
 790
 791         if ((ftmp->fw_vianame)[0]) {
 792                 if (!(ftmp->fw_viadev = dev_get_by_name(ftmp->fw_vianame)))
 793                         ftmp->fw_viadev = (struct net_device *) -1;
 794         } else
 795                 ftmp->fw_viadev = NULL;
 796
 797         ftmp->fw_next = *chainptr;
 798         *chainptr=ftmp;
 799         WRITE_UNLOCK(&ip_fw_lock);
 800         return(0);
 801 }
 802
 803 static int append_to_chain(struct ip_fw *volatile* chainptr, struct ip_fw *frwl,int len)
 804 {
 805         struct ip_fw *ftmp;
 806         struct ip_fw *chtmp=NULL;
 807         struct ip_fw *volatile chtmp_prev=NULL;
 808
 809         /* Are we unloading now?  We will block on nf_unregister_sockopt */
 810         if (!try_module_get(THIS_MODULE))
 811                 return ENOPROTOOPT;
 812
 813         ftmp = kmalloc( sizeof(struct ip_fw), GFP_KERNEL );
 814         if ( ftmp == NULL )
 815         {
 816 #ifdef DEBUG_IP_FIREWALL
 817                 printk("ip_fw_ctl:  malloc said no\n");
 818 #endif
 819                 return( ENOMEM );
 820         }
 821
 822         memcpy(ftmp, frwl, len);
 823         /*
 824          *      Allow the more recent "minimise cost" flag to be
 825          *      set. [Rob van Nieuwkerk]
 826          */
 827         ftmp->fw_tosand |= 0x01;
 828         ftmp->fw_tosxor &= 0xFE;
 829         ftmp->fw_pcnt=0L;
 830         ftmp->fw_bcnt=0L;
 831
 832         ftmp->fw_next = NULL;
 833
 834         WRITE_LOCK(&ip_fw_lock);
 835
 836         if ((ftmp->fw_vianame)[0]) {
 837                 if (!(ftmp->fw_viadev = dev_get_by_name(ftmp->fw_vianame)))
 838                         ftmp->fw_viadev = (struct net_device *) -1;
 839         } else
 840                 ftmp->fw_viadev = NULL;
 841
 842         chtmp_prev=NULL;
 843         for (chtmp=*chainptr;chtmp!=NULL;chtmp=chtmp->fw_next)
 844                 chtmp_prev=chtmp;
 845
 846         if (chtmp_prev)
 847                 chtmp_prev->fw_next=ftmp;
 848         else
 849                 *chainptr=ftmp;
 850         WRITE_UNLOCK(&ip_fw_lock);
 851         return(0);
 852 }
 853
 854 static int del_from_chain(struct ip_fw *volatile*chainptr, struct ip_fw *frwl)
 855 {
 856         struct ip_fw    *ftmp,*ltmp;
 857         unsigned short  tport1,tport2,tmpnum;
 858         char            matches,was_found;
 859
 860         WRITE_LOCK(&ip_fw_lock);
 861
 862         ftmp=*chainptr;
 863
 864         if ( ftmp == NULL )
 865         {
 866 #ifdef DEBUG_IP_FIREWALL
 867                 printk("ip_fw_ctl:  chain is empty\n");
 868 #endif
 869                 WRITE_UNLOCK(&ip_fw_lock);
 870                 return( EINVAL );
 871         }
 872
 873         ltmp=NULL;
 874         was_found=0;
 875
 876         while( !was_found && ftmp != NULL )
 877         {
 878                 matches=1;
 879                 if (ftmp->fw_src.s_addr!=frwl->fw_src.s_addr
 880                      ||  ftmp->fw_dst.s_addr!=frwl->fw_dst.s_addr
 881                      ||  ftmp->fw_smsk.s_addr!=frwl->fw_smsk.s_addr
 882                      ||  ftmp->fw_dmsk.s_addr!=frwl->fw_dmsk.s_addr
 883                      ||  ftmp->fw_via.s_addr!=frwl->fw_via.s_addr
 884                      ||  ftmp->fw_flg!=frwl->fw_flg)
 885                         matches=0;
 886
 887                 tport1=ftmp->fw_nsp+ftmp->fw_ndp;
 888                 tport2=frwl->fw_nsp+frwl->fw_ndp;
 889                 if (tport1!=tport2)
 890                         matches=0;
 891                 else if (tport1!=0)
 892                 {
 893                         for (tmpnum=0;tmpnum < tport1 && tmpnum < IP_FW_MAX_PORTS;tmpnum++)
 894                         if (ftmp->fw_pts[tmpnum]!=frwl->fw_pts[tmpnum])
 895                                 matches=0;
 896                 }
 897                 if (strncmp(ftmp->fw_vianame, frwl->fw_vianame, IFNAMSIZ))
 898                         matches=0;
 899                 if(matches)
 900                 {
 901                         was_found=1;
 902                         if (ftmp->fw_viadev
 903                             && ftmp->fw_viadev != (struct net_device *)-1)
 904                                 dev_put(ftmp->fw_viadev);
 905                         if (ltmp)
 906                         {
 907                                 ltmp->fw_next=ftmp->fw_next;
 908                                 kfree(ftmp);
 909                                 ftmp=ltmp->fw_next;
 910                         }
 911                         else
 912                         {
 913                                 *chainptr=ftmp->fw_next;
 914                                 kfree(ftmp);
 915                                 ftmp=*chainptr;
 916                         }
 917                 }
 918                 else
 919                 {
 920                         ltmp = ftmp;
 921                         ftmp = ftmp->fw_next;
 922                  }
 923         }
 924         WRITE_UNLOCK(&ip_fw_lock);
 925         if (was_found) {
 926                 /* We will block in cleanup's unregister sockopt if unloaded,
 927                    so this is safe. */
 928                 module_put(THIS_MODULE);
 929                 return 0;
 930         } else
 931                 return(EINVAL);
 932 }
 933
 934 #endif  /* CONFIG_IP_ACCT || CONFIG_IP_FIREWALL */
 935
 936 struct ip_fw *check_ipfw_struct(struct ip_fw *frwl, int len)
 937 {
 938
 939         if ( len != sizeof(struct ip_fw) )
 940         {
 941 #ifdef DEBUG_IP_FIREWALL
 942                 printk("ip_fw_ctl: len=%d, want %d\n",len, sizeof(struct ip_fw));
 943 #endif
 944                 return(NULL);
 945         }
 946
 947         if ( (frwl->fw_flg & ~IP_FW_F_MASK) != 0 )
 948         {
 949 #ifdef DEBUG_IP_FIREWALL
 950                 printk("ip_fw_ctl: undefined flag bits set (flags=%x)\n",
 951                         frwl->fw_flg);
 952 #endif
 953                 return(NULL);
 954         }
 955
 956 #ifndef CONFIG_IP_TRANSPARENT_PROXY
 957         if (frwl->fw_flg & IP_FW_F_REDIR) {
 958 #ifdef DEBUG_IP_FIREWALL
 959                 printk("ip_fw_ctl: unsupported flag IP_FW_F_REDIR\n");
 960 #endif
 961                 return(NULL);
 962         }
 963 #endif
 964
 965 #ifndef CONFIG_IP_MASQUERADE
 966         if (frwl->fw_flg & IP_FW_F_MASQ) {
 967 #ifdef DEBUG_IP_FIREWALL
 968                 printk("ip_fw_ctl: unsupported flag IP_FW_F_MASQ\n");
 969 #endif
 970                 return(NULL);
 971         }
 972 #endif
 973
 974         if ( (frwl->fw_flg & IP_FW_F_SRNG) && frwl->fw_nsp < 2 )
 975         {
 976 #ifdef DEBUG_IP_FIREWALL
 977                 printk("ip_fw_ctl: src range set but fw_nsp=%d\n",
 978                         frwl->fw_nsp);
 979 #endif
 980                 return(NULL);
 981         }
 982
 983         if ( (frwl->fw_flg & IP_FW_F_DRNG) && frwl->fw_ndp < 2 )
 984         {
 985 #ifdef DEBUG_IP_FIREWALL
 986                 printk("ip_fw_ctl: dst range set but fw_ndp=%d\n",
 987                         frwl->fw_ndp);
 988 #endif
 989                 return(NULL);
 990         }
 991
 992         if ( frwl->fw_nsp + frwl->fw_ndp > (frwl->fw_flg & IP_FW_F_REDIR ? IP_FW_MAX_PORTS - 1 : IP_FW_MAX_PORTS) )
 993         {
 994 #ifdef DEBUG_IP_FIREWALL
 995                 printk("ip_fw_ctl: too many ports (%d+%d)\n",
 996                         frwl->fw_nsp,frwl->fw_ndp);
 997 #endif
 998                 return(NULL);
 999         }
1000
1001         return frwl;
1002 }
1003
1004
1005
1006
1007 #ifdef CONFIG_IP_ACCT
1008
1009 int ip_acct_ctl(int stage, void *m, int len)
1010 {
1011         if ( stage == IP_ACCT_FLUSH )
1012         {
1013                 free_fw_chain(&ip_acct_chain);
1014                 return(0);
1015         }
1016         if ( stage == IP_ACCT_ZERO )
1017         {
1018                 zero_fw_chain(ip_acct_chain);
1019                 return(0);
1020         }
1021         if ( stage == IP_ACCT_INSERT || stage == IP_ACCT_APPEND ||
1022                                         stage == IP_ACCT_DELETE )
1023         {
1024                 struct ip_fw *frwl;
1025
1026                 if (!(frwl=check_ipfw_struct(m,len)))
1027                         return (EINVAL);
1028
1029                 switch (stage)
1030                 {
1031                         case IP_ACCT_INSERT:
1032                                 return( insert_in_chain(&ip_acct_chain,frwl,len));
1033                         case IP_ACCT_APPEND:
1034                                 return( append_to_chain(&ip_acct_chain,frwl,len));
1035                         case IP_ACCT_DELETE:
1036                                 return( del_from_chain(&ip_acct_chain,frwl));
1037                         default:
1038                                 /*
1039                                  *      Should be panic but... (Why ??? - AC)
1040                                  */
1041 #ifdef DEBUG_IP_FIREWALL
1042                                 printk("ip_acct_ctl:  unknown request %d\n",stage);
1043 #endif
1044                                 return(EINVAL);
1045                 }
1046         }
1047 #ifdef DEBUG_IP_FIREWALL
1048         printk("ip_acct_ctl:  unknown request %d\n",stage);
1049 #endif
1050         return(EINVAL);
1051 }
1052 #endif
1053
1054 #ifdef CONFIG_IP_FIREWALL
1055 int ip_fw_ctl(int stage, void *m, int len)
1056 {
1057         int cmd, fwtype;
1058
1059         cmd = stage & IP_FW_COMMAND;
1060         fwtype = (stage & IP_FW_TYPE) >> IP_FW_SHIFT;
1061
1062         if ( cmd == IP_FW_FLUSH )
1063         {
1064                 free_fw_chain(chains[fwtype]);
1065                 return(0);
1066         }
1067
1068         if ( cmd == IP_FW_ZERO )
1069         {
1070                 zero_fw_chain(*chains[fwtype]);
1071                 return(0);
1072         }
1073
1074         if ( cmd == IP_FW_POLICY )
1075         {
1076                 int *tmp_policy_ptr;
1077                 tmp_policy_ptr=(int *)m;
1078                 *policies[fwtype] = *tmp_policy_ptr;
1079                 return 0;
1080         }
1081
1082         if ( cmd == IP_FW_CHECK )
1083         {
1084                 struct sk_buff *tmp_skb;
1085                 struct net_device *viadev;
1086                 struct ip_fwpkt *ipfwp;
1087                 struct iphdr *ip;
1088                 int hdrlen, ret;
1089
1090                 hdrlen = sizeof(struct ip_fwpkt) -
1091                         sizeof(struct in_addr) -
1092                         IFNAMSIZ;
1093
1094                 if ( len != sizeof(struct ip_fwpkt) )
1095                 {
1096 #ifdef DEBUG_IP_FIREWALL
1097                         printk("ip_fw_ctl: length=%d, expected %d\n",
1098                                 len, sizeof(struct ip_fwpkt));
1099 #endif
1100                         return( EINVAL );
1101                 }
1102
1103                 ipfwp = (struct ip_fwpkt *)m;
1104                 ip = &(ipfwp->fwp_iph);
1105
1106                 if ( !(viadev = dev_get_by_name(ipfwp->fwp_vianame)) ) {
1107 #ifdef DEBUG_IP_FIREWALL
1108                         printk("ip_fw_ctl: invalid device \"%s\"\n", ipfwp->fwp_vianame);
1109 #endif
1110                         return(EINVAL);
1111                 } else if ( ip->ihl != sizeof(struct iphdr) / sizeof(int)) {
1112 #ifdef DEBUG_IP_FIREWALL
1113                         printk("ip_fw_ctl: ip->ihl=%d, want %d\n",ip->ihl,
1114                                         sizeof(struct iphdr)/sizeof(int));
1115 #endif
1116                         dev_put(viadev);
1117                         return(EINVAL);
1118                 }
1119
1120                 /* Fix this one up by hand, who knows how many
1121                  * tools will break if we start to barf on this.
1122                  */
1123                 if (ntohs(ip->tot_len) > hdrlen)
1124                         ip->tot_len = htons(hdrlen);
1125
1126                 if ((tmp_skb = alloc_skb(hdrlen, GFP_ATOMIC)) == NULL) {
1127 #ifdef DEBUG_IP_FIREWALL
1128                         printk("ip_fw_ctl: tmp_skb alloc failure\n");
1129 #endif
1130                         dev_put(viadev);
1131                         return(EFAULT);
1132                 }
1133                 skb_reserve(tmp_skb, hdrlen);
1134                 skb_push(tmp_skb, hdrlen);
1135                 memcpy(tmp_skb->data, ip, hdrlen);
1136
1137                 ret = ip_fw_chk(&tmp_skb, viadev, NULL, *chains[fwtype],
1138                                 *policies[fwtype], IP_FW_MODE_CHK);
1139
1140                 kfree_skb(tmp_skb);
1141                 dev_put(viadev);
1142
1143                 switch (ret) {
1144                         case FW_ACCEPT:
1145                                 return(0);
1146                         case FW_REDIRECT:
1147                                 return(ECONNABORTED);
1148                         case FW_MASQUERADE:
1149                                 return(ECONNRESET);
1150                         case FW_REJECT:
1151                                 return(ECONNREFUSED);
1152                         default: /* FW_BLOCK */
1153                                 return(ETIMEDOUT);
1154                 }
1155         }
1156
1157         if ( cmd == IP_FW_MASQ_TIMEOUTS )
1158                 return ip_fw_masq_timeouts(m, len);
1159
1160 /*
1161  *      Here we really working hard-adding new elements
1162  *      to blocking/forwarding chains or deleting 'em
1163  */
1164
1165         if ( cmd == IP_FW_INSERT || cmd == IP_FW_APPEND || cmd == IP_FW_DELETE )
1166         {
1167                 struct ip_fw *frwl;
1168                 int fwtype;
1169
1170                 frwl=check_ipfw_struct(m,len);
1171                 if (frwl==NULL)
1172                         return (EINVAL);
1173                 fwtype = (stage & IP_FW_TYPE) >> IP_FW_SHIFT;
1174
1175                 switch (cmd)
1176                 {
1177                         case IP_FW_INSERT:
1178                                 return(insert_in_chain(chains[fwtype],frwl,len));
1179                         case IP_FW_APPEND:
1180                                 return(append_to_chain(chains[fwtype],frwl,len));
1181                         case IP_FW_DELETE:
1182                                 return(del_from_chain(chains[fwtype],frwl));
1183                         default:
1184                         /*
1185                          *      Should be panic but... (Why are BSD people panic obsessed ??)
1186                          */
1187 #ifdef DEBUG_IP_FIREWALL
1188                                 printk("ip_fw_ctl:  unknown request %d\n",stage);
1189 #endif
1190                                 return(EINVAL);
1191                 }
1192         }
1193
1194 #ifdef DEBUG_IP_FIREWALL
1195         printk("ip_fw_ctl:  unknown request %d\n",stage);
1196 #endif
1197         return(ENOPROTOOPT);
1198 }
1199 #endif /* CONFIG_IP_FIREWALL */
1200
1201 #if defined(CONFIG_IP_FIREWALL) || defined(CONFIG_IP_ACCT)
1202 static int ip_chain_procinfo(int stage, char *buffer, char **start,
1203                              off_t offset, int length)
1204 {
1205         off_t pos=0, begin=0;
1206         struct ip_fw *i;
1207         int len, p;
1208         int last_len = 0;
1209
1210
1211         switch(stage)
1212         {
1213 #ifdef CONFIG_IP_FIREWALL
1214                 case IP_FW_IN:
1215                         i = ip_fw_in_chain;
1216                         len=sprintf(buffer, "IP firewall input rules, default %d\n",
1217                                 ip_fw_in_policy);
1218                         break;
1219                 case IP_FW_OUT:
1220                         i = ip_fw_out_chain;
1221                         len=sprintf(buffer, "IP firewall output rules, default %d\n",
1222                                 ip_fw_out_policy);
1223                         break;
1224                 case IP_FW_FWD:
1225                         i = ip_fw_fwd_chain;
1226                         len=sprintf(buffer, "IP firewall forward rules, default %d\n",
1227                                 ip_fw_fwd_policy);
1228                         break;
1229 #endif
1230 #ifdef CONFIG_IP_ACCT
1231                 case IP_FW_ACCT:
1232                         i = ip_acct_chain;
1233                         len=sprintf(buffer,"IP accounting rules\n");
1234                         break;
1235 #endif
1236                 default:
1237                         /* this should never be reached, but safety first... */
1238                         i = NULL;
1239                         len=0;
1240                         break;
1241         }
1242
1243         READ_LOCK(&ip_fw_lock);
1244
1245         while(i!=NULL)
1246         {
1247                 len+=sprintf(buffer+len,"%08X/%08X->%08X/%08X %.16s %08X %X ",
1248                         ntohl(i->fw_src.s_addr),ntohl(i->fw_smsk.s_addr),
1249                         ntohl(i->fw_dst.s_addr),ntohl(i->fw_dmsk.s_addr),
1250                         (i->fw_vianame)[0] ? i->fw_vianame : "-",
1251                         ntohl(i->fw_via.s_addr), i->fw_flg);
1252                 /* 10 is enough for a 32 bit box but the counters are 64bit on
1253                    the Alpha and Ultrapenguin */
1254                 len+=sprintf(buffer+len,"%u %u %-20lu %-20lu",
1255                         i->fw_nsp,i->fw_ndp, i->fw_pcnt,i->fw_bcnt);
1256                 for (p = 0; p < IP_FW_MAX_PORTS; p++)
1257                         len+=sprintf(buffer+len, " %u", i->fw_pts[p]);
1258                 len+=sprintf(buffer+len, " A%02X X%02X", i->fw_tosand, i->fw_tosxor);
1259                 buffer[len++]='\n';
1260                 buffer[len]='\0';
1261                 pos=begin+len;
1262                 if(pos<offset)
1263                 {
1264                         len=0;
1265                         begin=pos;
1266                 }
1267                 else if(pos>offset+length)
1268                 {
1269                         len = last_len;
1270                         break;
1271                 }
1272                 last_len = len;
1273                 i=i->fw_next;
1274         }
1275         READ_UNLOCK(&ip_fw_lock);
1276         *start=buffer+(offset-begin);
1277         len-=(offset-begin);
1278         if(len>length)
1279                 len=length;
1280         return len;
1281 }
1282 #endif
1283
1284 #ifdef CONFIG_IP_ACCT
1285 static int ip_acct_procinfo(char *buffer, char **start, off_t offset,
1286                             int length)
1287 {
1288         return ip_chain_procinfo(IP_FW_ACCT, buffer,start, offset,length);
1289 }
1290 #endif
1291
1292 #ifdef CONFIG_IP_FIREWALL
1293 static int ip_fw_in_procinfo(char *buffer, char **start, off_t offset,
1294                               int length)
1295 {
1296         return ip_chain_procinfo(IP_FW_IN, buffer,start,offset,length);
1297 }
1298
1299 static int ip_fw_out_procinfo(char *buffer, char **start, off_t offset,
1300                               int length)
1301 {
1302         return ip_chain_procinfo(IP_FW_OUT, buffer,start,offset,length);
1303 }
1304
1305 static int ip_fw_fwd_procinfo(char *buffer, char **start, off_t offset,
1306                               int length)
1307 {
1308         return ip_chain_procinfo(IP_FW_FWD, buffer,start,offset,length);
1309 }
1310 #endif
1311
1312
1313 #ifdef CONFIG_IP_FIREWALL
1314 /*
1315  *      Interface to the generic firewall chains.
1316  */
1317
1318 int ipfw_input_check(struct firewall_ops *this, int pf,
1319                      struct net_device *dev, void *arg,
1320                      struct sk_buff **pskb)
1321 {
1322         return ip_fw_chk(pskb, dev, arg, ip_fw_in_chain, ip_fw_in_policy,
1323                          IP_FW_MODE_FW);
1324 }
1325
1326 int ipfw_output_check(struct firewall_ops *this, int pf,
1327                       struct net_device *dev, void *arg,
1328                       struct sk_buff **pskb)
1329 {
1330         return ip_fw_chk(pskb, dev, arg, ip_fw_out_chain, ip_fw_out_policy,
1331                          IP_FW_MODE_FW);
1332 }
1333
1334 int ipfw_forward_check(struct firewall_ops *this, int pf,
1335                        struct net_device *dev, void *arg,
1336                        struct sk_buff **pskb)
1337 {
1338         return ip_fw_chk(pskb, dev, arg, ip_fw_fwd_chain, ip_fw_fwd_policy,
1339                          IP_FW_MODE_FW);
1340 }
1341
1342 #ifdef CONFIG_IP_ACCT
1343 int ipfw_acct_in(struct firewall_ops *this, int pf, struct net_device *dev,
1344                  void *arg, struct sk_buff **pskb)
1345 {
1346         return ip_fw_chk(pskb,dev,NULL,ip_acct_chain,0,IP_FW_MODE_ACCT_IN);
1347 }
1348
1349 int ipfw_acct_out(struct firewall_ops *this, int pf, struct net_device *dev,
1350                   void *arg, struct sk_buff **pskb)
1351 {
1352         return ip_fw_chk(pskb,dev,NULL,ip_acct_chain,0,IP_FW_MODE_ACCT_OUT);
1353 }
1354 #endif
1355
1356 struct firewall_ops ipfw_ops = {
1357         .fw_forward     =       ipfw_forward_check,
1358         .fw_input       =       ipfw_input_check,
1359         .fw_output      =       ipfw_output_check,
1360 #ifdef CONFIG_IP_ACCT
1361         .fw_acct_in     =       ipfw_acct_in,
1362         .fw_acct_out    =       ipfw_acct_out,
1363 #endif
1364 };
1365
1366 #endif
1367
1368 #if defined(CONFIG_IP_ACCT) || defined(CONFIG_IP_FIREWALL)
1369
1370 int ipfw_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1371 {
1372         struct net_device *dev=ptr;
1373         char *devname = dev->name;
1374         struct ip_fw *fw;
1375         int chn;
1376
1377         WRITE_LOCK(&ip_fw_lock);
1378
1379         if (event == NETDEV_UP) {
1380                 for (chn = 0; chn < IP_FW_CHAINS; chn++)
1381                         for (fw = *chains[chn]; fw; fw = fw->fw_next)
1382                                 if ((fw->fw_vianame)[0] && !strncmp(devname,
1383                                             fw->fw_vianame, IFNAMSIZ)) {
1384                                         dev_hold(dev);
1385                                         fw->fw_viadev = dev;
1386                                 }
1387         } else if (event == NETDEV_DOWN) {
1388                 for (chn = 0; chn < IP_FW_CHAINS; chn++)
1389                         for (fw = *chains[chn]; fw; fw = fw->fw_next)
1390                                 /* we could compare just the pointers ... */
1391                                 if ((fw->fw_vianame)[0] && !strncmp(devname,
1392                                                     fw->fw_vianame, IFNAMSIZ)){
1393                                         if (fw->fw_viadev
1394                                             && fw->fw_viadev != (struct net_device *)-1)
1395                                                 dev_put(fw->fw_viadev);
1396                                         fw->fw_viadev = (struct net_device*)-1;
1397                                 }
1398         }
1399
1400         WRITE_UNLOCK(&ip_fw_lock);
1401         return NOTIFY_DONE;
1402 }
1403
1404 static struct notifier_block ipfw_dev_notifier = {
1405         .notifier_call  =       ipfw_device_event,
1406 };
1407
1408 #endif
1409
1410 int ipfw_init_or_cleanup(int init)
1411 {
1412         int ret = 0;
1413
1414         if (!init)
1415                 goto cleanup;
1416
1417         ret = register_firewall(PF_INET, &ipfw_ops);
1418         if (ret < 0)
1419                 goto cleanup_nothing;
1420
1421 #ifdef CONFIG_IP_ACCT
1422         proc_net_create("ip_acct", S_IFREG | S_IRUGO | S_IWUSR, ip_acct_procinfo);
1423 #endif
1424         proc_net_create("ip_input", S_IFREG | S_IRUGO | S_IWUSR, ip_fw_in_procinfo);
1425         proc_net_create("ip_output", S_IFREG | S_IRUGO | S_IWUSR, ip_fw_out_procinfo);
1426         proc_net_create("ip_forward", S_IFREG | S_IRUGO | S_IWUSR, ip_fw_fwd_procinfo);
1427
1428         /* Register for device up/down reports */
1429         register_netdevice_notifier(&ipfw_dev_notifier);
1430
1431 #ifdef CONFIG_IP_FIREWALL_NETLINK
1432         ipfwsk = netlink_kernel_create(NETLINK_FIREWALL, NULL);
1433 #endif
1434         return ret;
1435
1436  cleanup:
1437 #ifdef CONFIG_IP_FIREWALL_NETLINK
1438         sock_release(ipfwsk->sk_socket);
1439 #endif
1440         unregister_netdevice_notifier(&ipfw_dev_notifier);
1441
1442 #ifdef CONFIG_IP_ACCT
1443         proc_net_remove("ip_acct");
1444 #endif
1445         proc_net_remove("ip_input");
1446         proc_net_remove("ip_output");
1447         proc_net_remove("ip_forward");
1448
1449         free_fw_chain(chains[IP_FW_FWD]);
1450         free_fw_chain(chains[IP_FW_IN]);
1451         free_fw_chain(chains[IP_FW_OUT]);
1452         free_fw_chain(chains[IP_FW_ACCT]);
1453
1454         unregister_firewall(PF_INET, &ipfw_ops);
1455
1456  cleanup_nothing:
1457         return ret;
1458 }