target/linux/generic-2.4/patches/611-netfilter_condition.patch

   1 --- a/Documentation/Configure.help
   2 +++ b/Documentation/Configure.help
   3 @@ -2979,6 +2979,14 @@ CONFIG_IP_NF_MATCH_TOS
   4    If you want to compile it as a module, say M here and read
   5    <file:Documentation/modules.txt>.  If unsure, say `N'.
   6
   7 +Condition variable match support
   8 +CONFIG_IP_NF_MATCH_CONDITION
   9 +  This option allows you to match firewall rules against condition
  10 +  variables stored in the /proc/net/ipt_condition directory.
  11 +
  12 +  If you want to compile it as a module, say M here and read
  13 +  Documentation/modules.txt.  If unsure, say `N'.
  14 +
  15  conntrack match support
  16  CONFIG_IP_NF_MATCH_CONNTRACK
  17    This is a general conntrack match module, a superset of the state match.
  18 @@ -3296,6 +3304,14 @@ CONFIG_IP6_NF_MATCH_MARK
  19    If you want to compile it as a module, say M here and read
  20    <file:Documentation/modules.txt>.  If unsure, say `N'.
  21
  22 +Condition variable match support
  23 +CONFIG_IP6_NF_MATCH_CONDITION
  24 +  This option allows you to match firewall rules against condition
  25 +  variables stored in the /proc/net/ipt_condition directory.
  26 +
  27 +  If you want to compile it as a module, say M here and read
  28 +  Documentation/modules.txt.  If unsure, say `N'.
  29 +
  30  Multiple port match support
  31  CONFIG_IP6_NF_MATCH_MULTIPORT
  32    Multiport matching allows you to match TCP or UDP packets based on
  33 --- /dev/null
  34 +++ b/include/linux/netfilter_ipv4/ipt_condition.h
  35 @@ -0,0 +1,11 @@
  36 +#ifndef __IPT_CONDITION_MATCH__
  37 +#define __IPT_CONDITION_MATCH__
  38 +
  39 +#define CONDITION_NAME_LEN  32
  40 +
  41 +struct condition_info {
  42 +       char name[CONDITION_NAME_LEN];
  43 +       int  invert;
  44 +};
  45 +
  46 +#endif
  47 --- /dev/null
  48 +++ b/include/linux/netfilter_ipv6/ip6t_condition.h
  49 @@ -0,0 +1,11 @@
  50 +#ifndef __IP6T_CONDITION_MATCH__
  51 +#define __IP6T_CONDITION_MATCH__
  52 +
  53 +#define CONDITION6_NAME_LEN  32
  54 +
  55 +struct condition6_info {
  56 +       char name[CONDITION6_NAME_LEN];
  57 +       int  invert;
  58 +};
  59 +
  60 +#endif
  61 --- a/net/ipv4/netfilter/Config.in
  62 +++ b/net/ipv4/netfilter/Config.in
  63 @@ -27,6 +27,7 @@ if [ "$CONFIG_IP_NF_IPTABLES" != "n" ];
  64    dep_tristate '  netfilter MARK match support' CONFIG_IP_NF_MATCH_MARK $CONFIG_IP_NF_IPTABLES
  65    dep_tristate '  Multiple port match support' CONFIG_IP_NF_MATCH_MULTIPORT $CONFIG_IP_NF_IPTABLES
  66    dep_tristate '  TOS match support' CONFIG_IP_NF_MATCH_TOS $CONFIG_IP_NF_IPTABLES
  67 +  dep_tristate '  condition match support' CONFIG_IP_NF_MATCH_CONDITION $CONFIG_IP_NF_IPTABLES
  68    dep_tristate '  recent match support' CONFIG_IP_NF_MATCH_RECENT $CONFIG_IP_NF_IPTABLES
  69    dep_tristate '  ECN match support' CONFIG_IP_NF_MATCH_ECN $CONFIG_IP_NF_IPTABLES
  70    dep_tristate '  peer to peer traffic match support' CONFIG_IP_NF_MATCH_IPP2P $CONFIG_IP_NF_IPTABLES
  71 --- a/net/ipv4/netfilter/Makefile
  72 +++ b/net/ipv4/netfilter/Makefile
  73 @@ -73,6 +73,7 @@ obj-$(CONFIG_IP_NF_MATCH_PKTTYPE) += ipt
  74  obj-$(CONFIG_IP_NF_MATCH_MULTIPORT) += ipt_multiport.o
  75  obj-$(CONFIG_IP_NF_MATCH_OWNER) += ipt_owner.o
  76  obj-$(CONFIG_IP_NF_MATCH_TOS) += ipt_tos.o
  77 +obj-$(CONFIG_IP_NF_MATCH_CONDITION) += ipt_condition.o
  78
  79  obj-$(CONFIG_IP_NF_MATCH_RECENT) += ipt_recent.o
  80
  81 --- /dev/null
  82 +++ b/net/ipv4/netfilter/ipt_condition.c
  83 @@ -0,0 +1,256 @@
  84 +/*-------------------------------------------*\
  85 +|          Netfilter Condition Module         |
  86 +|                                             |
  87 +|  Description: This module allows firewall   |
  88 +|    rules to match using condition variables |
  89 +|    stored in /proc files.                   |
  90 +|                                             |
  91 +|  Author: Stephane Ouellette     2002-10-22  |
  92 +|          <ouellettes@videotron.ca>          |
  93 +|                                             |
  94 +|  History:                                   |
  95 +|    2003-02-10  Second version with improved |
  96 +|                locking and simplified code. |
  97 +|                                             |
  98 +|  This software is distributed under the     |
  99 +|  terms of the GNU GPL.                      |
 100 +\*-------------------------------------------*/
 101 +
 102 +#include<linux/module.h>
 103 +#include<linux/proc_fs.h>
 104 +#include<linux/spinlock.h>
 105 +#include<linux/string.h>
 106 +#include<asm/atomic.h>
 107 +#include<linux/netfilter_ipv4/ip_tables.h>
 108 +#include<linux/netfilter_ipv4/ipt_condition.h>
 109 +
 110 +
 111 +#ifndef CONFIG_PROC_FS
 112 +#error  "Proc file system support is required for this module"
 113 +#endif
 114 +
 115 +
 116 +MODULE_AUTHOR("Stephane Ouellette <ouellettes@videotron.ca>");
 117 +MODULE_DESCRIPTION("Allows rules to match against condition variables");
 118 +MODULE_LICENSE("GPL");
 119 +
 120 +
 121 +struct condition_variable {
 122 +       struct condition_variable *next;
 123 +       struct proc_dir_entry *status_proc;
 124 +       atomic_t refcount;
 125 +        int enabled;   /* TRUE == 1, FALSE == 0 */
 126 +};
 127 +
 128 +
 129 +static rwlock_t list_lock;
 130 +static struct condition_variable *head = NULL;
 131 +static struct proc_dir_entry *proc_net_condition = NULL;
 132 +
 133 +
 134 +static int
 135 +ipt_condition_read_info(char *buffer, char **start, off_t offset,
 136 +                       int length, int *eof, void *data)
 137 +{
 138 +       struct condition_variable *var =
 139 +           (struct condition_variable *) data;
 140 +
 141 +       if (offset == 0) {
 142 +               *start = buffer;
 143 +               buffer[0] = (var->enabled) ? '1' : '0';
 144 +               buffer[1] = '\n';
 145 +               return 2;
 146 +       }
 147 +
 148 +       *eof = 1;
 149 +       return 0;
 150 +}
 151 +
 152 +
 153 +static int
 154 +ipt_condition_write_info(struct file *file, const char *buffer,
 155 +                        unsigned long length, void *data)
 156 +{
 157 +       struct condition_variable *var =
 158 +           (struct condition_variable *) data;
 159 +
 160 +       if (length) {
 161 +               /* Match only on the first character */
 162 +               switch (buffer[0]) {
 163 +               case '0':
 164 +                       var->enabled = 0;
 165 +                       break;
 166 +               case '1':
 167 +                       var->enabled = 1;
 168 +               }
 169 +       }
 170 +
 171 +       return (int) length;
 172 +}
 173 +
 174 +
 175 +static int
 176 +match(const struct sk_buff *skb, const struct net_device *in,
 177 +      const struct net_device *out, const void *matchinfo, int offset,
 178 +      const void *hdr, u_int16_t datalen, int *hotdrop)
 179 +{
 180 +       const struct condition_info *info =
 181 +           (const struct condition_info *) matchinfo;
 182 +       struct condition_variable *var;
 183 +       int condition_status = 0;
 184 +
 185 +       read_lock(&list_lock);
 186 +
 187 +       for (var = head; var; var = var->next) {
 188 +               if (strcmp(info->name, var->status_proc->name) == 0) {
 189 +                       condition_status = var->enabled;
 190 +                       break;
 191 +               }
 192 +       }
 193 +
 194 +       read_unlock(&list_lock);
 195 +
 196 +       return condition_status ^ info->invert;
 197 +}
 198 +
 199 +
 200 +
 201 +static int
 202 +checkentry(const char *tablename, const struct ipt_ip *ip,
 203 +          void *matchinfo, unsigned int matchsize, unsigned int hook_mask)
 204 +{
 205 +       struct condition_info *info = (struct condition_info *) matchinfo;
 206 +       struct condition_variable *var, *newvar;
 207 +
 208 +       if (matchsize != IPT_ALIGN(sizeof(struct condition_info)))
 209 +               return 0;
 210 +
 211 +       /* The first step is to check if the condition variable already exists. */
 212 +       /* Here, a read lock is sufficient because we won't change the list */
 213 +       read_lock(&list_lock);
 214 +
 215 +       for (var = head; var; var = var->next) {
 216 +               if (strcmp(info->name, var->status_proc->name) == 0) {
 217 +                       atomic_inc(&var->refcount);
 218 +                       read_unlock(&list_lock);
 219 +                       return 1;
 220 +               }
 221 +       }
 222 +
 223 +       read_unlock(&list_lock);
 224 +
 225 +       /* At this point, we need to allocate a new condition variable */
 226 +       newvar = kmalloc(sizeof(struct condition_variable), GFP_KERNEL);
 227 +
 228 +       if (!newvar)
 229 +               return -ENOMEM;
 230 +
 231 +       /* Create the condition variable's proc file entry */
 232 +       newvar->status_proc = create_proc_entry(info->name, 0644, proc_net_condition);
 233 +
 234 +       if (!newvar->status_proc) {
 235 +         /*
 236 +          * There are two possibilities:
 237 +          *  1- Another condition variable with the same name has been created, which is valid.
 238 +          *  2- There was a memory allocation error.
 239 +          */
 240 +               kfree(newvar);
 241 +               read_lock(&list_lock);
 242 +
 243 +               for (var = head; var; var = var->next) {
 244 +                       if (strcmp(info->name, var->status_proc->name) == 0) {
 245 +                               atomic_inc(&var->refcount);
 246 +                               read_unlock(&list_lock);
 247 +                               return 1;
 248 +                       }
 249 +               }
 250 +
 251 +               read_unlock(&list_lock);
 252 +               return -ENOMEM;
 253 +       }
 254 +
 255 +       atomic_set(&newvar->refcount, 1);
 256 +       newvar->enabled = 0;
 257 +       newvar->status_proc->owner = THIS_MODULE;
 258 +       newvar->status_proc->data = newvar;
 259 +       wmb();
 260 +       newvar->status_proc->read_proc = ipt_condition_read_info;
 261 +       newvar->status_proc->write_proc = ipt_condition_write_info;
 262 +
 263 +       write_lock(&list_lock);
 264 +
 265 +       newvar->next = head;
 266 +       head = newvar;
 267 +
 268 +       write_unlock(&list_lock);
 269 +
 270 +       return 1;
 271 +}
 272 +
 273 +
 274 +static void
 275 +destroy(void *matchinfo, unsigned int matchsize)
 276 +{
 277 +       struct condition_info *info = (struct condition_info *) matchinfo;
 278 +       struct condition_variable *var, *prev = NULL;
 279 +
 280 +       if (matchsize != IPT_ALIGN(sizeof(struct condition_info)))
 281 +               return;
 282 +
 283 +       write_lock(&list_lock);
 284 +
 285 +       for (var = head; var && strcmp(info->name, var->status_proc->name);
 286 +            prev = var, var = var->next);
 287 +
 288 +       if (var && atomic_dec_and_test(&var->refcount)) {
 289 +               if (prev)
 290 +                       prev->next = var->next;
 291 +               else
 292 +                       head = var->next;
 293 +
 294 +               write_unlock(&list_lock);
 295 +               remove_proc_entry(var->status_proc->name, proc_net_condition);
 296 +               kfree(var);
 297 +       } else
 298 +               write_unlock(&list_lock);
 299 +}
 300 +
 301 +
 302 +static struct ipt_match condition_match = {
 303 +       .name = "condition",
 304 +       .match = &match,
 305 +       .checkentry = &checkentry,
 306 +       .destroy = &destroy,
 307 +       .me = THIS_MODULE
 308 +};
 309 +
 310 +
 311 +static int __init
 312 +init(void)
 313 +{
 314 +       int errorcode;
 315 +
 316 +       rwlock_init(&list_lock);
 317 +       proc_net_condition = proc_mkdir("ipt_condition", proc_net);
 318 +
 319 +       if (proc_net_condition) {
 320 +               errorcode = ipt_register_match(&condition_match);
 321 +
 322 +               if (errorcode)
 323 +                       remove_proc_entry("ipt_condition", proc_net);
 324 +       } else
 325 +               errorcode = -EACCES;
 326 +
 327 +       return errorcode;
 328 +}
 329 +
 330 +
 331 +static void __exit
 332 +fini(void)
 333 +{
 334 +       ipt_unregister_match(&condition_match);
 335 +       remove_proc_entry("ipt_condition", proc_net);
 336 +}
 337 +
 338 +module_init(init);
 339 +module_exit(fini);
 340 --- a/net/ipv6/netfilter/Config.in
 341 +++ b/net/ipv6/netfilter/Config.in
 342 @@ -17,6 +17,7 @@ tristate 'IP6 tables support (required f
 343  if [ "$CONFIG_IP6_NF_IPTABLES" != "n" ]; then
 344  # The simple matches.
 345    dep_tristate '  limit match support' CONFIG_IP6_NF_MATCH_LIMIT $CONFIG_IP6_NF_IPTABLES
 346 +  dep_tristate '  condition match support' CONFIG_IP6_NF_MATCH_CONDITION $CONFIG_IP6_NF_IPTABLES
 347    dep_tristate '  MAC address match support' CONFIG_IP6_NF_MATCH_MAC $CONFIG_IP6_NF_IPTABLES
 348    if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
 349      dep_tristate '  Routing header match support (EXPERIMENTAL)' CONFIG_IP6_NF_MATCH_RT $CONFIG_IP6_NF_IPTABLES
 350 --- a/net/ipv6/netfilter/Makefile
 351 +++ b/net/ipv6/netfilter/Makefile
 352 @@ -14,6 +14,7 @@ export-objs := ip6_tables.o
 353  # Link order matters here.
 354  obj-$(CONFIG_IP6_NF_IPTABLES) += ip6_tables.o
 355  obj-$(CONFIG_IP6_NF_MATCH_LIMIT) += ip6t_limit.o
 356 +obj-$(CONFIG_IP6_NF_MATCH_CONDITION) += ip6t_condition.o
 357  obj-$(CONFIG_IP6_NF_MATCH_MARK) += ip6t_mark.o
 358  obj-$(CONFIG_IP6_NF_MATCH_LENGTH) += ip6t_length.o
 359  obj-$(CONFIG_IP6_NF_MATCH_MAC) += ip6t_mac.o
 360 --- /dev/null
 361 +++ b/net/ipv6/netfilter/ip6t_condition.c
 362 @@ -0,0 +1,254 @@
 363 +/*-------------------------------------------*\
 364 +|    Netfilter Condition Module for IPv6      |
 365 +|                                             |
 366 +|  Description: This module allows firewall   |
 367 +|    rules to match using condition variables |
 368 +|    stored in /proc files.                   |
 369 +|                                             |
 370 +|  Author: Stephane Ouellette     2003-02-10  |
 371 +|          <ouellettes@videotron.ca>          |
 372 +|                                             |
 373 +|  This software is distributed under the     |
 374 +|  terms of the GNU GPL.                      |
 375 +\*-------------------------------------------*/
 376 +
 377 +#include<linux/module.h>
 378 +#include<linux/proc_fs.h>
 379 +#include<linux/spinlock.h>
 380 +#include<linux/string.h>
 381 +#include<asm/atomic.h>
 382 +#include<linux/netfilter_ipv6/ip6_tables.h>
 383 +#include<linux/netfilter_ipv6/ip6t_condition.h>
 384 +
 385 +
 386 +#ifndef CONFIG_PROC_FS
 387 +#error  "Proc file system support is required for this module"
 388 +#endif
 389 +
 390 +
 391 +MODULE_AUTHOR("Stephane Ouellette <ouellettes@videotron.ca>");
 392 +MODULE_DESCRIPTION("Allows rules to match against condition variables");
 393 +MODULE_LICENSE("GPL");
 394 +
 395 +
 396 +struct condition_variable {
 397 +       struct condition_variable *next;
 398 +       struct proc_dir_entry *status_proc;
 399 +       atomic_t refcount;
 400 +        int enabled; /* TRUE == 1, FALSE == 0 */
 401 +};
 402 +
 403 +
 404 +static rwlock_t list_lock;
 405 +static struct condition_variable *head = NULL;
 406 +static struct proc_dir_entry *proc_net_condition = NULL;
 407 +
 408 +
 409 +static int
 410 +ipt_condition_read_info(char *buffer, char **start, off_t offset,
 411 +                       int length, int *eof, void *data)
 412 +{
 413 +       struct condition_variable *var =
 414 +           (struct condition_variable *) data;
 415 +
 416 +       if (offset == 0) {
 417 +               *start = buffer;
 418 +               buffer[0] = (var->enabled) ? '1' : '0';
 419 +               buffer[1] = '\n';
 420 +               return 2;
 421 +       }
 422 +
 423 +       *eof = 1;
 424 +       return 0;
 425 +}
 426 +
 427 +
 428 +static int
 429 +ipt_condition_write_info(struct file *file, const char *buffer,
 430 +                        unsigned long length, void *data)
 431 +{
 432 +       struct condition_variable *var =
 433 +           (struct condition_variable *) data;
 434 +
 435 +       if (length) {
 436 +               /* Match only on the first character */
 437 +               switch (buffer[0]) {
 438 +               case '0':
 439 +                       var->enabled = 0;
 440 +                       break;
 441 +               case '1':
 442 +                       var->enabled = 1;
 443 +               }
 444 +       }
 445 +
 446 +       return (int) length;
 447 +}
 448 +
 449 +
 450 +static int
 451 +match(const struct sk_buff *skb, const struct net_device *in,
 452 +      const struct net_device *out, const void *matchinfo, int offset,
 453 +      const void *hdr, u_int16_t datalen, int *hotdrop)
 454 +{
 455 +       const struct condition6_info *info =
 456 +           (const struct condition6_info *) matchinfo;
 457 +       struct condition_variable *var;
 458 +       int condition_status = 0;
 459 +
 460 +       read_lock(&list_lock);
 461 +
 462 +       for (var = head; var; var = var->next) {
 463 +               if (strcmp(info->name, var->status_proc->name) == 0) {
 464 +                       condition_status = var->enabled;
 465 +                       break;
 466 +               }
 467 +       }
 468 +
 469 +       read_unlock(&list_lock);
 470 +
 471 +       return condition_status ^ info->invert;
 472 +}
 473 +
 474 +
 475 +
 476 +static int
 477 +checkentry(const char *tablename, const struct ip6t_ip6 *ip,
 478 +          void *matchinfo, unsigned int matchsize, unsigned int hook_mask)
 479 +{
 480 +       struct condition6_info *info =
 481 +           (struct condition6_info *) matchinfo;
 482 +       struct condition_variable *var, *newvar;
 483 +
 484 +       if (matchsize != IP6T_ALIGN(sizeof(struct condition6_info)))
 485 +               return 0;
 486 +
 487 +       /* The first step is to check if the condition variable already exists. */
 488 +       /* Here, a read lock is sufficient because we won't change the list */
 489 +       read_lock(&list_lock);
 490 +
 491 +       for (var = head; var; var = var->next) {
 492 +               if (strcmp(info->name, var->status_proc->name) == 0) {
 493 +                       atomic_inc(&var->refcount);
 494 +                       read_unlock(&list_lock);
 495 +                       return 1;
 496 +               }
 497 +       }
 498 +
 499 +       read_unlock(&list_lock);
 500 +
 501 +       /* At this point, we need to allocate a new condition variable */
 502 +       newvar = kmalloc(sizeof(struct condition_variable), GFP_KERNEL);
 503 +
 504 +       if (!newvar)
 505 +               return -ENOMEM;
 506 +
 507 +       /* Create the condition variable's proc file entry */
 508 +       newvar->status_proc = create_proc_entry(info->name, 0644, proc_net_condition);
 509 +
 510 +       if (!newvar->status_proc) {
 511 +         /*
 512 +          * There are two possibilities:
 513 +          *  1- Another condition variable with the same name has been created, which is valid.
 514 +          *  2- There was a memory allocation error.
 515 +          */
 516 +               kfree(newvar);
 517 +               read_lock(&list_lock);
 518 +
 519 +               for (var = head; var; var = var->next) {
 520 +                       if (strcmp(info->name, var->status_proc->name) == 0) {
 521 +                               atomic_inc(&var->refcount);
 522 +                               read_unlock(&list_lock);
 523 +                               return 1;
 524 +                       }
 525 +               }
 526 +
 527 +               read_unlock(&list_lock);
 528 +               return -ENOMEM;
 529 +       }
 530 +
 531 +       atomic_set(&newvar->refcount, 1);
 532 +       newvar->enabled = 0;
 533 +       newvar->status_proc->owner = THIS_MODULE;
 534 +       newvar->status_proc->data = newvar;
 535 +       wmb();
 536 +       newvar->status_proc->read_proc = ipt_condition_read_info;
 537 +       newvar->status_proc->write_proc = ipt_condition_write_info;
 538 +
 539 +       write_lock(&list_lock);
 540 +
 541 +       newvar->next = head;
 542 +       head = newvar;
 543 +
 544 +       write_unlock(&list_lock);
 545 +
 546 +       return 1;
 547 +}
 548 +
 549 +
 550 +static void
 551 +destroy(void *matchinfo, unsigned int matchsize)
 552 +{
 553 +       struct condition6_info *info =
 554 +           (struct condition6_info *) matchinfo;
 555 +       struct condition_variable *var, *prev = NULL;
 556 +
 557 +       if (matchsize != IP6T_ALIGN(sizeof(struct condition6_info)))
 558 +               return;
 559 +
 560 +       write_lock(&list_lock);
 561 +
 562 +       for (var = head; var && strcmp(info->name, var->status_proc->name);
 563 +            prev = var, var = var->next);
 564 +
 565 +       if (var && atomic_dec_and_test(&var->refcount)) {
 566 +               if (prev)
 567 +                       prev->next = var->next;
 568 +               else
 569 +                       head = var->next;
 570 +
 571 +               write_unlock(&list_lock);
 572 +               remove_proc_entry(var->status_proc->name, proc_net_condition);
 573 +               kfree(var);
 574 +       } else
 575 +               write_unlock(&list_lock);
 576 +}
 577 +
 578 +
 579 +static struct ip6t_match condition_match = {
 580 +       .name = "condition",
 581 +       .match = &match,
 582 +       .checkentry = &checkentry,
 583 +       .destroy = &destroy,
 584 +       .me = THIS_MODULE
 585 +};
 586 +
 587 +
 588 +static int __init
 589 +init(void)
 590 +{
 591 +       int errorcode;
 592 +
 593 +       rwlock_init(&list_lock);
 594 +       proc_net_condition = proc_mkdir("ip6t_condition", proc_net);
 595 +
 596 +       if (proc_net_condition) {
 597 +               errorcode = ipt_register_match(&condition_match);
 598 +
 599 +               if (errorcode)
 600 +                       remove_proc_entry("ip6t_condition", proc_net);
 601 +       } else
 602 +               errorcode = -EACCES;
 603 +
 604 +       return errorcode;
 605 +}
 606 +
 607 +
 608 +static void __exit
 609 +fini(void)
 610 +{
 611 +       ipt_unregister_match(&condition_match);
 612 +       remove_proc_entry("ip6t_condition", proc_net);
 613 +}
 614 +
 615 +module_init(init);
 616 +module_exit(fini);