target/linux/generic-2.4/patches/602-netfilter_layer7_2.21.patch

   1 --- a/Documentation/Configure.help
   2 +++ b/Documentation/Configure.help
   3 @@ -29207,6 +29207,18 @@
   4
   5    If unsure, say N.
   6
   7 +CONFIG_IP_NF_MATCH_LAYER7
   8 +   Say Y if you want to be able to classify connections (and their
   9 +   packets) based on regular expression matching of their application
  10 +   layer data.   This is one way to classify applications such as
  11 +   peer-to-peer filesharing systems that do not always use the same
  12 +   port.
  13 +
  14 +   To compile it as a module, choose M here.  If unsure, say N.
  15 +
  16 +CONFIG_IP_NF_MATCH_LAYER7_DEBUG
  17 +   Say Y to get lots of debugging output.
  18 +
  19  #
  20  # A couple of things I keep forgetting:
  21  #   capitalize: AppleTalk, Ethernet, DOS, DMA, FAT, FTP, Internet,
  22 --- a/include/linux/netfilter_ipv4/ip_conntrack.h
  23 +++ b/include/linux/netfilter_ipv4/ip_conntrack.h
  24 @@ -207,6 +207,17 @@
  25         } nat;
  26  #endif /* CONFIG_IP_NF_NAT_NEEDED */
  27
  28 +#if defined(CONFIG_IP_NF_MATCH_LAYER7) || defined(CONFIG_IP_NF_MATCH_LAYER7_MODULE)
  29 +       struct {
  30 +               unsigned int numpackets; /* surely this is kept track of somewhere else, right? I can't find it... */
  31 +               char * app_proto; /* "http", "ftp", etc.  NULL if unclassifed */
  32 +
  33 +               /* the application layer data so far.  NULL if ->numpackets > numpackets */
  34 +               char * app_data;
  35 +
  36 +               unsigned int app_data_len;
  37 +       } layer7;
  38 +#endif
  39  };
  40
  41  /* get master conntrack via master expectation */
  42 --- /dev/null
  43 +++ b/include/linux/netfilter_ipv4/ipt_layer7.h
  44 @@ -0,0 +1,26 @@
  45 +/*
  46 +  By Matthew Strait <quadong@users.sf.net>, Dec 2003.
  47 +  http://l7-filter.sf.net
  48 +
  49 +  This program is free software; you can redistribute it and/or
  50 +  modify it under the terms of the GNU General Public License
  51 +  as published by the Free Software Foundation; either version
  52 +  2 of the License, or (at your option) any later version.
  53 +  http://www.gnu.org/licenses/gpl.txt
  54 +*/
  55 +
  56 +#ifndef _IPT_LAYER7_H
  57 +#define _IPT_LAYER7_H
  58 +
  59 +#define MAX_PATTERN_LEN 8192
  60 +#define MAX_PROTOCOL_LEN 256
  61 +
  62 +typedef char *(*proc_ipt_search) (char *, char, char *);
  63 +
  64 +struct ipt_layer7_info {
  65 +    char protocol[MAX_PROTOCOL_LEN];
  66 +    char invert:1;
  67 +    char pattern[MAX_PATTERN_LEN];
  68 +};
  69 +
  70 +#endif /* _IPT_LAYER7_H */
  71 --- a/net/ipv4/netfilter/Config.in
  72 +++ b/net/ipv4/netfilter/Config.in
  73 @@ -44,6 +44,9 @@
  74    if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
  75      dep_tristate '  Unclean match support (EXPERIMENTAL)' CONFIG_IP_NF_MATCH_UNCLEAN $CONFIG_IP_NF_IPTABLES
  76      dep_tristate '  Owner match support (EXPERIMENTAL)' CONFIG_IP_NF_MATCH_OWNER $CONFIG_IP_NF_IPTABLES
  77 +    dep_tristate '  Layer 7 match support (EXPERIMENTAL)' CONFIG_IP_NF_MATCH_LAYER7 $CONFIG_IP_NF_CONNTRACK
  78 +    dep_mbool '  Layer 7 debugging output (EXPERIMENTAL)' CONFIG_IP_NF_MATCH_LAYER7_DEBUG $CONFIG_IP_NF_MATCH_LAYER7
  79 +
  80    fi
  81  # The targets
  82    dep_tristate '  Packet filtering' CONFIG_IP_NF_FILTER $CONFIG_IP_NF_IPTABLES
  83 --- a/net/ipv4/netfilter/Makefile
  84 +++ b/net/ipv4/netfilter/Makefile
  85 @@ -87,6 +87,7 @@
  86  obj-$(CONFIG_IP_NF_MATCH_CONNTRACK) += ipt_conntrack.o
  87  obj-$(CONFIG_IP_NF_MATCH_UNCLEAN) += ipt_unclean.o
  88  obj-$(CONFIG_IP_NF_MATCH_TCPMSS) += ipt_tcpmss.o
  89 +obj-$(CONFIG_IP_NF_MATCH_LAYER7) += ipt_layer7.o
  90
  91  # targets
  92  obj-$(CONFIG_IP_NF_TARGET_REJECT) += ipt_REJECT.o
  93 --- a/net/ipv4/netfilter/ip_conntrack_core.c
  94 +++ b/net/ipv4/netfilter/ip_conntrack_core.c
  95 @@ -346,6 +346,14 @@
  96                 }
  97                 kfree(ct->master);
  98         }
  99 +
 100 +       #if defined(CONFIG_IP_NF_MATCH_LAYER7) || defined(CONFIG_IP_NF_MATCH_LAYER7_MODULE)
 101 +       if(ct->layer7.app_proto)
 102 +               kfree(ct->layer7.app_proto);
 103 +       if(ct->layer7.app_data)
 104 +               kfree(ct->layer7.app_data);
 105 +       #endif
 106 +
 107         WRITE_UNLOCK(&ip_conntrack_lock);
 108
 109         if (master)
 110 --- a/net/ipv4/netfilter/ip_conntrack_standalone.c
 111 +++ b/net/ipv4/netfilter/ip_conntrack_standalone.c
 112 @@ -107,6 +107,13 @@
 113                 len += sprintf(buffer + len, "[ASSURED] ");
 114         len += sprintf(buffer + len, "use=%u ",
 115                        atomic_read(&conntrack->ct_general.use));
 116 +
 117 +       #if defined(CONFIG_IP_NF_MATCH_LAYER7) || defined(CONFIG_IP_NF_MATCH_LAYER7_MODULE)
 118 +       if(conntrack->layer7.app_proto)
 119 +               len += sprintf(buffer + len, "l7proto=%s ",
 120 +                               conntrack->layer7.app_proto);
 121 +       #endif
 122 +
 123         len += sprintf(buffer + len, "\n");
 124
 125         return len;
 126 --- /dev/null
 127 +++ b/net/ipv4/netfilter/ipt_layer7.c
 128 @@ -0,0 +1,570 @@
 129 +/*
 130 +  Kernel module to match application layer (OSI layer 7)
 131 +  data in connections.
 132 +
 133 +  http://l7-filter.sf.net
 134 +
 135 +  By Matthew Strait and Ethan Sommer, 2003-2005.
 136 +
 137 +  This program is free software; you can redistribute it and/or
 138 +  modify it under the terms of the GNU General Public License
 139 +  as published by the Free Software Foundation; either version
 140 +  2 of the License, or (at your option) any later version.
 141 +  http://www.gnu.org/licenses/gpl.txt
 142 +
 143 +  Based on ipt_string.c (C) 2000 Emmanuel Roger <winfield@freegates.be>
 144 +  and cls_layer7.c (C) 2003 Matthew Strait, Ethan Sommer, Justin Levandoski
 145 +*/
 146 +
 147 +#include <linux/module.h>
 148 +#include <linux/skbuff.h>
 149 +#include <linux/netfilter_ipv4/ip_conntrack.h>
 150 +#include <linux/proc_fs.h>
 151 +#include <linux/ctype.h>
 152 +#include <net/ip.h>
 153 +#include <net/tcp.h>
 154 +#include <linux/netfilter_ipv4/lockhelp.h>
 155 +
 156 +#include "regexp/regexp.c"
 157 +
 158 +#include <linux/netfilter_ipv4/ipt_layer7.h>
 159 +#include <linux/netfilter_ipv4/ip_tables.h>
 160 +
 161 +MODULE_AUTHOR("Matthew Strait <quadong@users.sf.net>, Ethan Sommer <sommere@users.sf.net>");
 162 +MODULE_LICENSE("GPL");
 163 +MODULE_DESCRIPTION("iptables application layer match module");
 164 +
 165 +static int maxdatalen = 2048; // this is the default
 166 +MODULE_PARM(maxdatalen,"i");
 167 +MODULE_PARM_DESC(maxdatalen,"maximum bytes of data looked at by l7-filter");
 168 +
 169 +#if defined(CONFIG_IP_NF_MATCH_LAYER7_DEBUG)
 170 +       #define DPRINTK(format,args...) printk(format,##args)
 171 +#else
 172 +       #define DPRINTK(format,args...)
 173 +#endif
 174 +
 175 +#define TOTAL_PACKETS master_conntrack->layer7.numpackets
 176 +
 177 +/* Number of packets whose data we look at.
 178 +This can be modified through /proc/net/layer7_numpackets */
 179 +static int num_packets = 10;
 180 +
 181 +static struct pattern_cache {
 182 +       char * regex_string;
 183 +       regexp * pattern;
 184 +       struct pattern_cache * next;
 185 +} * first_pattern_cache = NULL;
 186 +
 187 +/* I'm new to locking.  Here are my assumptions:
 188 +
 189 +- No one will write to /proc/net/layer7_numpackets over and over very fast;
 190 +  if they did, nothing awful would happen.
 191 +
 192 +- This code will never be processing the same packet twice at the same time,
 193 +  because iptables rules are traversed in order.
 194 +
 195 +- It doesn't matter if two packets from different connections are in here at
 196 +  the same time, because they don't share any data.
 197 +
 198 +- It _does_ matter if two packets from the same connection are here at the same
 199 +  time.  In this case, we have to protect the conntracks and the list of
 200 +  compiled patterns.
 201 +*/
 202 +DECLARE_RWLOCK(ct_lock);
 203 +DECLARE_LOCK(list_lock);
 204 +
 205 +#if CONFIG_IP_NF_MATCH_LAYER7_DEBUG
 206 +/* Converts an unfriendly string into a friendly one by
 207 +replacing unprintables with periods and all whitespace with " ". */
 208 +static char * friendly_print(unsigned char * s)
 209 +{
 210 +       char * f = kmalloc(strlen(s) + 1, GFP_ATOMIC);
 211 +       int i;
 212 +
 213 +       if(!f) {
 214 +               if (net_ratelimit())
 215 +                       printk(KERN_ERR "layer7: out of memory in friendly_print, bailing.\n");
 216 +               return NULL;
 217 +       }
 218 +
 219 +       for(i = 0; i < strlen(s); i++){
 220 +               if(isprint(s[i]) && s[i] < 128) f[i] = s[i];
 221 +               else if(isspace(s[i]))          f[i] = ' ';
 222 +               else                            f[i] = '.';
 223 +       }
 224 +       f[i] = '\0';
 225 +       return f;
 226 +}
 227 +
 228 +static char dec2hex(int i)
 229 +{
 230 +       switch (i) {
 231 +               case 0 ... 9:
 232 +                       return (char)(i + '0');
 233 +                       break;
 234 +               case 10 ... 15:
 235 +                       return (char)(i - 10 + 'a');
 236 +                       break;
 237 +               default:
 238 +                       if (net_ratelimit())
 239 +                               printk("Problem in dec2hex\n");
 240 +                       return '\0';
 241 +       }
 242 +}
 243 +
 244 +static char * hex_print(unsigned char * s)
 245 +{
 246 +       char * g = kmalloc(strlen(s)*3 + 1, GFP_ATOMIC);
 247 +       int i;
 248 +
 249 +       if(!g) {
 250 +               if (net_ratelimit())
 251 +                       printk(KERN_ERR "layer7: out of memory in hex_print, bailing.\n");
 252 +               return NULL;
 253 +       }
 254 +
 255 +       for(i = 0; i < strlen(s); i++) {
 256 +               g[i*3    ] = dec2hex(s[i]/16);
 257 +               g[i*3 + 1] = dec2hex(s[i]%16);
 258 +               g[i*3 + 2] = ' ';
 259 +       }
 260 +       g[i*3] = '\0';
 261 +
 262 +       return g;
 263 +}
 264 +#endif // DEBUG
 265 +
 266 +/* Use instead of regcomp.  As we expect to be seeing the same regexps over and
 267 +over again, it make sense to cache the results. */
 268 +static regexp * compile_and_cache(char * regex_string, char * protocol)
 269 +{
 270 +       struct pattern_cache * node               = first_pattern_cache;
 271 +       struct pattern_cache * last_pattern_cache = first_pattern_cache;
 272 +       struct pattern_cache * tmp;
 273 +       unsigned int len;
 274 +
 275 +       while (node != NULL) {
 276 +               if (!strcmp(node->regex_string, regex_string))
 277 +                       return node->pattern;
 278 +
 279 +               last_pattern_cache = node;/* points at the last non-NULL node */
 280 +               node = node->next;
 281 +       }
 282 +
 283 +       /* If we reach the end of the list, then we have not yet cached
 284 +          the pattern for this regex. Let's do that now.
 285 +          Be paranoid about running out of memory to avoid list corruption. */
 286 +       tmp = kmalloc(sizeof(struct pattern_cache), GFP_ATOMIC);
 287 +
 288 +       if(!tmp) {
 289 +               if (net_ratelimit())
 290 +                       printk(KERN_ERR "layer7: out of memory in compile_and_cache, bailing.\n");
 291 +               return NULL;
 292 +       }
 293 +
 294 +       tmp->regex_string  = kmalloc(strlen(regex_string) + 1, GFP_ATOMIC);
 295 +       tmp->pattern       = kmalloc(sizeof(struct regexp),    GFP_ATOMIC);
 296 +       tmp->next = NULL;
 297 +
 298 +       if(!tmp->regex_string || !tmp->pattern) {
 299 +               if (net_ratelimit())
 300 +                       printk(KERN_ERR "layer7: out of memory in compile_and_cache, bailing.\n");
 301 +               kfree(tmp->regex_string);
 302 +               kfree(tmp->pattern);
 303 +               kfree(tmp);
 304 +               return NULL;
 305 +       }
 306 +
 307 +       /* Ok.  The new node is all ready now. */
 308 +       node = tmp;
 309 +
 310 +       if(first_pattern_cache == NULL) /* list is empty */
 311 +               first_pattern_cache = node; /* make node the beginning */
 312 +       else
 313 +               last_pattern_cache->next = node; /* attach node to the end */
 314 +
 315 +       /* copy the string and compile the regex */
 316 +       len = strlen(regex_string);
 317 +       DPRINTK("About to compile this: \"%s\"\n", regex_string);
 318 +       node->pattern = regcomp(regex_string, &len);
 319 +       if ( !node->pattern ) {
 320 +               if (net_ratelimit())
 321 +                       printk(KERN_ERR "layer7: Error compiling regexp \"%s\" (%s)\n", regex_string, protocol);
 322 +               /* pattern is now cached as NULL, so we won't try again. */
 323 +       }
 324 +
 325 +       strcpy(node->regex_string, regex_string);
 326 +       return node->pattern;
 327 +}
 328 +
 329 +static int can_handle(const struct sk_buff *skb)
 330 +{
 331 +       if(!skb->nh.iph) /* not IP */
 332 +               return 0;
 333 +       if(skb->nh.iph->protocol != IPPROTO_TCP &&
 334 +          skb->nh.iph->protocol != IPPROTO_UDP &&
 335 +          skb->nh.iph->protocol != IPPROTO_ICMP)
 336 +               return 0;
 337 +       return 1;
 338 +}
 339 +
 340 +/* Returns offset the into the skb->data that the application data starts */
 341 +static int app_data_offset(const struct sk_buff *skb)
 342 +{
 343 +       /* In case we are ported somewhere (ebtables?) where skb->nh.iph
 344 +       isn't set, this can be gotten from 4*(skb->data[0] & 0x0f) as well. */
 345 +       int ip_hl = 4*skb->nh.iph->ihl;
 346 +
 347 +       if( skb->nh.iph->protocol == IPPROTO_TCP ) {
 348 +               /* 12 == offset into TCP header for the header length field.
 349 +               Can't get this with skb->h.th->doff because the tcphdr
 350 +               struct doesn't get set when routing (this is confirmed to be
 351 +               true in Netfilter as well as QoS.) */
 352 +               int tcp_hl = 4*(skb->data[ip_hl + 12] >> 4);
 353 +
 354 +               return ip_hl + tcp_hl;
 355 +       } else if( skb->nh.iph->protocol == IPPROTO_UDP  ) {
 356 +               return ip_hl + 8; /* UDP header is always 8 bytes */
 357 +       } else if( skb->nh.iph->protocol == IPPROTO_ICMP ) {
 358 +               return ip_hl + 8; /* ICMP header is 8 bytes */
 359 +       } else {
 360 +               if (net_ratelimit())
 361 +                       printk(KERN_ERR "layer7: tried to handle unknown protocol!\n");
 362 +               return ip_hl + 8; /* something reasonable */
 363 +       }
 364 +}
 365 +
 366 +/* handles whether there's a match when we aren't appending data anymore */
 367 +static int match_no_append(struct ip_conntrack * conntrack, struct ip_conntrack * master_conntrack,
 368 +                       enum ip_conntrack_info ctinfo, enum ip_conntrack_info master_ctinfo,
 369 +                       struct ipt_layer7_info * info)
 370 +{
 371 +       /* If we're in here, throw the app data away */
 372 +       WRITE_LOCK(&ct_lock);
 373 +       if(master_conntrack->layer7.app_data != NULL) {
 374 +
 375 +       #ifdef CONFIG_IP_NF_MATCH_LAYER7_DEBUG
 376 +               if(!master_conntrack->layer7.app_proto) {
 377 +                       char * f = friendly_print(master_conntrack->layer7.app_data);
 378 +                       char * g = hex_print(master_conntrack->layer7.app_data);
 379 +                       DPRINTK("\nl7-filter gave up after %d bytes (%d packets):\n%s\n",
 380 +                               strlen(f),
 381 +                               TOTAL_PACKETS, f);
 382 +                       kfree(f);
 383 +                       DPRINTK("In hex: %s\n", g);
 384 +                       kfree(g);
 385 +               }
 386 +       #endif
 387 +
 388 +               kfree(master_conntrack->layer7.app_data);
 389 +               master_conntrack->layer7.app_data = NULL; /* don't free again */
 390 +       }
 391 +       WRITE_UNLOCK(&ct_lock);
 392 +
 393 +       if(master_conntrack->layer7.app_proto){
 394 +               /* Here child connections set their .app_proto (for /proc/net/ip_conntrack) */
 395 +               WRITE_LOCK(&ct_lock);
 396 +               if(!conntrack->layer7.app_proto) {
 397 +                       conntrack->layer7.app_proto = kmalloc(strlen(master_conntrack->layer7.app_proto)+1, GFP_ATOMIC);
 398 +                       if(!conntrack->layer7.app_proto){
 399 +                               if (net_ratelimit())
 400 +                                       printk(KERN_ERR "layer7: out of memory in match_no_append, bailing.\n");
 401 +                               WRITE_UNLOCK(&ct_lock);
 402 +                               return 1;
 403 +                       }
 404 +                       strcpy(conntrack->layer7.app_proto, master_conntrack->layer7.app_proto);
 405 +               }
 406 +               WRITE_UNLOCK(&ct_lock);
 407 +
 408 +               return (!strcmp(master_conntrack->layer7.app_proto, info->protocol));
 409 +       }
 410 +       else {
 411 +               /* If not classified, set to "unknown" to distinguish from
 412 +               connections that are still being tested. */
 413 +               WRITE_LOCK(&ct_lock);
 414 +               master_conntrack->layer7.app_proto = kmalloc(strlen("unknown")+1, GFP_ATOMIC);
 415 +               if(!master_conntrack->layer7.app_proto){
 416 +                       if (net_ratelimit())
 417 +                               printk(KERN_ERR "layer7: out of memory in match_no_append, bailing.\n");
 418 +                       WRITE_UNLOCK(&ct_lock);
 419 +                       return 1;
 420 +               }
 421 +               strcpy(master_conntrack->layer7.app_proto, "unknown");
 422 +               WRITE_UNLOCK(&ct_lock);
 423 +               return 0;
 424 +       }
 425 +}
 426 +
 427 +/* add the new app data to the conntrack.  Return number of bytes added. */
 428 +static int add_data(struct ip_conntrack * master_conntrack,
 429 +                       char * app_data, int appdatalen)
 430 +{
 431 +       int length = 0, i;
 432 +       int oldlength = master_conntrack->layer7.app_data_len;
 433 +
 434 +       /* Strip nulls. Make everything lower case (our regex lib doesn't
 435 +       do case insensitivity).  Add it to the end of the current data. */
 436 +       for(i = 0; i < maxdatalen-oldlength-1 && i < appdatalen; i++) {
 437 +               if(app_data[i] != '\0') {
 438 +                       master_conntrack->layer7.app_data[length+oldlength] =
 439 +                               /* the kernel version of tolower mungs 'upper ascii' */
 440 +                               isascii(app_data[i])? tolower(app_data[i]) : app_data[i];
 441 +                       length++;
 442 +               }
 443 +       }
 444 +
 445 +       master_conntrack->layer7.app_data[length+oldlength] = '\0';
 446 +       master_conntrack->layer7.app_data_len = length + oldlength;
 447 +
 448 +       return length;
 449 +}
 450 +
 451 +/* Returns true on match and false otherwise.  */
 452 +static int match(/* const */struct sk_buff *skb, const struct net_device *in,
 453 +                const struct net_device *out, const void *matchinfo,
 454 +                int offset,               int *hotdrop)
 455 +{
 456 +       struct ipt_layer7_info * info = (struct ipt_layer7_info *)matchinfo;
 457 +       enum ip_conntrack_info master_ctinfo, ctinfo;
 458 +       struct ip_conntrack *master_conntrack, *conntrack;
 459 +       unsigned char * app_data;
 460 +       unsigned int pattern_result, appdatalen;
 461 +       regexp * comppattern;
 462 +
 463 +       if(!can_handle(skb)){
 464 +               DPRINTK("layer7: This is some protocol I can't handle.\n");
 465 +               return info->invert;
 466 +       }
 467 +
 468 +       /* Treat the parent and all its children together as one connection,
 469 +       except for the purpose of setting conntrack->layer7.app_proto in the
 470 +       actual connection. This makes /proc/net/ip_conntrack somewhat more
 471 +       satisfying. */
 472 +       if(!(conntrack  = ip_conntrack_get((struct sk_buff *)skb, &ctinfo)) ||
 473 +          !(master_conntrack = ip_conntrack_get((struct sk_buff *)skb, &master_ctinfo))) {
 474 +               DPRINTK("layer7: packet is not from a known connection, giving up.\n");
 475 +               return info->invert;
 476 +       }
 477 +
 478 +       /* Try to get a master conntrack (and its master etc) for FTP, etc. */
 479 +       while (master_ct(master_conntrack) != NULL)
 480 +               master_conntrack = master_ct(master_conntrack);
 481 +
 482 +       if(!skb->cb[0]){
 483 +               WRITE_LOCK(&ct_lock);
 484 +               master_conntrack->layer7.numpackets++;/*starts at 0 via memset*/
 485 +               WRITE_UNLOCK(&ct_lock);
 486 +       }
 487 +
 488 +       /* if we've classified it or seen too many packets */
 489 +       if(TOTAL_PACKETS > num_packets ||
 490 +          master_conntrack->layer7.app_proto) {
 491 +
 492 +               pattern_result = match_no_append(conntrack, master_conntrack, ctinfo, master_ctinfo, info);
 493 +
 494 +               /* skb->cb[0] == seen. Avoid doing things twice if there are two l7
 495 +               rules. I'm not sure that using cb for this purpose is correct, although
 496 +               it says "put your private variables there". But it doesn't look like it
 497 +               is being used for anything else in the skbs that make it here. How can
 498 +               I write to cb without making the compiler angry? */
 499 +               skb->cb[0] = 1; /* marking it seen here is probably irrelevant, but consistant */
 500 +
 501 +               return (pattern_result ^ info->invert);
 502 +       }
 503 +
 504 +       if(skb_is_nonlinear(skb)){
 505 +               if(skb_linearize(skb, GFP_ATOMIC) != 0){
 506 +                       if (net_ratelimit())
 507 +                               printk(KERN_ERR "layer7: failed to linearize packet, bailing.\n");
 508 +                       return info->invert;
 509 +               }
 510 +       }
 511 +
 512 +       /* now that the skb is linearized, it's safe to set these. */
 513 +       app_data = skb->data + app_data_offset(skb);
 514 +       appdatalen = skb->tail - app_data;
 515 +
 516 +       LOCK_BH(&list_lock);
 517 +       /* the return value gets checked later, when we're ready to use it */
 518 +       comppattern = compile_and_cache(info->pattern, info->protocol);
 519 +       UNLOCK_BH(&list_lock);
 520 +
 521 +       /* On the first packet of a connection, allocate space for app data */
 522 +       WRITE_LOCK(&ct_lock);
 523 +       if(TOTAL_PACKETS == 1 && !skb->cb[0] && !master_conntrack->layer7.app_data) {
 524 +               master_conntrack->layer7.app_data = kmalloc(maxdatalen, GFP_ATOMIC);
 525 +               if(!master_conntrack->layer7.app_data){
 526 +                       if (net_ratelimit())
 527 +                               printk(KERN_ERR "layer7: out of memory in match, bailing.\n");
 528 +                       WRITE_UNLOCK(&ct_lock);
 529 +                       return info->invert;
 530 +               }
 531 +
 532 +               master_conntrack->layer7.app_data[0] = '\0';
 533 +       }
 534 +       WRITE_UNLOCK(&ct_lock);
 535 +
 536 +       /* Can be here, but unallocated, if numpackets is increased near
 537 +       the beginning of a connection */
 538 +       if(master_conntrack->layer7.app_data == NULL)
 539 +               return (info->invert); /* unmatched */
 540 +
 541 +       if(!skb->cb[0]){
 542 +               int newbytes;
 543 +               WRITE_LOCK(&ct_lock);
 544 +               newbytes = add_data(master_conntrack, app_data, appdatalen);
 545 +               WRITE_UNLOCK(&ct_lock);
 546 +
 547 +               if(newbytes == 0) { /* didn't add any data */
 548 +                       skb->cb[0] = 1;
 549 +                       /* Didn't match before, not going to match now */
 550 +                       return info->invert;
 551 +               }
 552 +       }
 553 +
 554 +       /* If looking for "unknown", then never match.  "Unknown" means that
 555 +       we've given up; we're still trying with these packets. */
 556 +       if(!strcmp(info->protocol, "unknown")) {
 557 +               pattern_result = 0;
 558 +       /* If the regexp failed to compile, don't bother running it */
 559 +       } else if(comppattern && regexec(comppattern, master_conntrack->layer7.app_data)) {
 560 +               DPRINTK("layer7: regexec positive: %s!\n", info->protocol);
 561 +               pattern_result = 1;
 562 +       } else pattern_result = 0;
 563 +
 564 +       if(pattern_result) {
 565 +               WRITE_LOCK(&ct_lock);
 566 +               master_conntrack->layer7.app_proto = kmalloc(strlen(info->protocol)+1, GFP_ATOMIC);
 567 +               if(!master_conntrack->layer7.app_proto){
 568 +                       if (net_ratelimit())
 569 +                               printk(KERN_ERR "layer7: out of memory in match, bailing.\n");
 570 +                       WRITE_UNLOCK(&ct_lock);
 571 +                       return (pattern_result ^ info->invert);
 572 +               }
 573 +               strcpy(master_conntrack->layer7.app_proto, info->protocol);
 574 +               WRITE_UNLOCK(&ct_lock);
 575 +       }
 576 +
 577 +       /* mark the packet seen */
 578 +       skb->cb[0] = 1;
 579 +
 580 +       return (pattern_result ^ info->invert);
 581 +}
 582 +
 583 +static int checkentry(const char *tablename, const struct ipt_ip *ip,
 584 +          void *matchinfo, unsigned int matchsize, unsigned int hook_mask)
 585 +{
 586 +       if (matchsize != IPT_ALIGN(sizeof(struct ipt_layer7_info)))
 587 +               return 0;
 588 +       return 1;
 589 +}
 590 +
 591 +static struct ipt_match layer7_match = {
 592 +       .name = "layer7",
 593 +       .match = &match,
 594 +       .checkentry = &checkentry,
 595 +       .me = THIS_MODULE
 596 +};
 597 +
 598 +/* taken from drivers/video/modedb.c */
 599 +static int my_atoi(const char *s)
 600 +{
 601 +       int val = 0;
 602 +
 603 +       for (;; s++) {
 604 +               switch (*s) {
 605 +               case '0'...'9':
 606 +                       val = 10*val+(*s-'0');
 607 +                       break;
 608 +               default:
 609 +                       return val;
 610 +               }
 611 +       }
 612 +}
 613 +
 614 +/* write out num_packets to userland. */
 615 +static int layer7_read_proc(char* page, char ** start, off_t off, int count,
 616 +                    int* eof, void * data)
 617 +{
 618 +       if(num_packets > 99 && net_ratelimit())
 619 +               printk(KERN_ERR "layer7: NOT REACHED. num_packets too big\n");
 620 +
 621 +       page[0] = num_packets/10 + '0';
 622 +       page[1] = num_packets%10 + '0';
 623 +       page[2] = '\n';
 624 +       page[3] = '\0';
 625 +
 626 +       *eof=1;
 627 +
 628 +       return 3;
 629 +}
 630 +
 631 +/* Read in num_packets from userland */
 632 +static int layer7_write_proc(struct file* file, const char* buffer,
 633 +                     unsigned long count, void *data)
 634 +{
 635 +       char * foo = kmalloc(count, GFP_ATOMIC);
 636 +
 637 +       if(!foo){
 638 +               if (net_ratelimit())
 639 +                       printk(KERN_ERR "layer7: out of memory, bailing. num_packets unchanged.\n");
 640 +               return count;
 641 +       }
 642 +
 643 +       copy_from_user(foo, buffer, count);
 644 +
 645 +       num_packets = my_atoi(foo);
 646 +       kfree (foo);
 647 +
 648 +       /* This has an arbitrary limit to make the math easier. I'm lazy.
 649 +       But anyway, 99 is a LOT! If you want more, you're doing it wrong! */
 650 +       if(num_packets > 99) {
 651 +               printk(KERN_WARNING "layer7: num_packets can't be > 99.\n");
 652 +               num_packets = 99;
 653 +       } else if(num_packets < 1) {
 654 +               printk(KERN_WARNING "layer7: num_packets can't be < 1.\n");
 655 +               num_packets = 1;
 656 +       }
 657 +
 658 +       return count;
 659 +}
 660 +
 661 +/* register the proc file */
 662 +static void layer7_init_proc(void)
 663 +{
 664 +       struct proc_dir_entry* entry;
 665 +       entry = create_proc_entry("layer7_numpackets", 0644, proc_net);
 666 +       entry->read_proc = layer7_read_proc;
 667 +       entry->write_proc = layer7_write_proc;
 668 +}
 669 +
 670 +static void layer7_cleanup_proc(void)
 671 +{
 672 +       remove_proc_entry("layer7_numpackets", proc_net);
 673 +}
 674 +
 675 +static int __init init(void)
 676 +{
 677 +       layer7_init_proc();
 678 +       if(maxdatalen < 1) {
 679 +               printk(KERN_WARNING "layer7: maxdatalen can't be < 1, using 1\n");
 680 +               maxdatalen = 1;
 681 +       }
 682 +       /* This is not a hard limit.  It's just here to prevent people from
 683 +       bringing their slow machines to a grinding halt. */
 684 +       else if(maxdatalen > 65536) {
 685 +               printk(KERN_WARNING "layer7: maxdatalen can't be > 65536, using 65536\n");
 686 +               maxdatalen = 65536;
 687 +       }
 688 +       return ipt_register_match(&layer7_match);
 689 +}
 690 +
 691 +static void __exit fini(void)
 692 +{
 693 +       layer7_cleanup_proc();
 694 +       ipt_unregister_match(&layer7_match);
 695 +}
 696 +
 697 +module_init(init);
 698 +module_exit(fini);
 699 --- /dev/null
 700 +++ b/net/ipv4/netfilter/regexp/regexp.c
 701 @@ -0,0 +1,1195 @@
 702 +/*
 703 + * regcomp and regexec -- regsub and regerror are elsewhere
 704 + * @(#)regexp.c        1.3 of 18 April 87
 705 + *
 706 + *     Copyright (c) 1986 by University of Toronto.
 707 + *     Written by Henry Spencer.  Not derived from licensed software.
 708 + *
 709 + *     Permission is granted to anyone to use this software for any
 710 + *     purpose on any computer system, and to redistribute it freely,
 711 + *     subject to the following restrictions:
 712 + *
 713 + *     1. The author is not responsible for the consequences of use of
 714 + *             this software, no matter how awful, even if they arise
 715 + *             from defects in it.
 716 + *
 717 + *     2. The origin of this software must not be misrepresented, either
 718 + *             by explicit claim or by omission.
 719 + *
 720 + *     3. Altered versions must be plainly marked as such, and must not
 721 + *             be misrepresented as being the original software.
 722 + *
 723 + * Beware that some of this code is subtly aware of the way operator
 724 + * precedence is structured in regular expressions.  Serious changes in
 725 + * regular-expression syntax might require a total rethink.
 726 + *
 727 + * This code was modified by Ethan Sommer to work within the kernel
 728 + * (it now uses kmalloc etc..)
 729 + *
 730 + * Modified slightly by Matthew Strait to use more modern C.
 731 + */
 732 +
 733 +#include "regexp.h"
 734 +#include "regmagic.h"
 735 +
 736 +/* added by ethan and matt.  Lets it work in both kernel and user space.
 737 +(So iptables can use it, for instance.)  Yea, it goes both ways... */
 738 +#if __KERNEL__
 739 +  #define malloc(foo) kmalloc(foo,GFP_ATOMIC)
 740 +#else
 741 +  #define printk(format,args...) printf(format,##args)
 742 +#endif
 743 +
 744 +void regerror(char * s)
 745 +{
 746 +        printk("<3>Regexp: %s\n", s);
 747 +        /* NOTREACHED */
 748 +}
 749 +
 750 +/*
 751 + * The "internal use only" fields in regexp.h are present to pass info from
 752 + * compile to execute that permits the execute phase to run lots faster on
 753 + * simple cases.  They are:
 754 + *
 755 + * regstart    char that must begin a match; '\0' if none obvious
 756 + * reganch     is the match anchored (at beginning-of-line only)?
 757 + * regmust     string (pointer into program) that match must include, or NULL
 758 + * regmlen     length of regmust string
 759 + *
 760 + * Regstart and reganch permit very fast decisions on suitable starting points
 761 + * for a match, cutting down the work a lot.  Regmust permits fast rejection
 762 + * of lines that cannot possibly match.  The regmust tests are costly enough
 763 + * that regcomp() supplies a regmust only if the r.e. contains something
 764 + * potentially expensive (at present, the only such thing detected is * or +
 765 + * at the start of the r.e., which can involve a lot of backup).  Regmlen is
 766 + * supplied because the test in regexec() needs it and regcomp() is computing
 767 + * it anyway.
 768 + */
 769 +
 770 +/*
 771 + * Structure for regexp "program".  This is essentially a linear encoding
 772 + * of a nondeterministic finite-state machine (aka syntax charts or
 773 + * "railroad normal form" in parsing technology).  Each node is an opcode
 774 + * plus a "next" pointer, possibly plus an operand.  "Next" pointers of
 775 + * all nodes except BRANCH implement concatenation; a "next" pointer with
 776 + * a BRANCH on both ends of it is connecting two alternatives.  (Here we
 777 + * have one of the subtle syntax dependencies:  an individual BRANCH (as
 778 + * opposed to a collection of them) is never concatenated with anything
 779 + * because of operator precedence.)  The operand of some types of node is
 780 + * a literal string; for others, it is a node leading into a sub-FSM.  In
 781 + * particular, the operand of a BRANCH node is the first node of the branch.
 782 + * (NB this is *not* a tree structure:  the tail of the branch connects
 783 + * to the thing following the set of BRANCHes.)  The opcodes are:
 784 + */
 785 +
 786 +/* definition  number  opnd?   meaning */
 787 +#define        END     0       /* no   End of program. */
 788 +#define        BOL     1       /* no   Match "" at beginning of line. */
 789 +#define        EOL     2       /* no   Match "" at end of line. */
 790 +#define        ANY     3       /* no   Match any one character. */
 791 +#define        ANYOF   4       /* str  Match any character in this string. */
 792 +#define        ANYBUT  5       /* str  Match any character not in this string. */
 793 +#define        BRANCH  6       /* node Match this alternative, or the next... */
 794 +#define        BACK    7       /* no   Match "", "next" ptr points backward. */
 795 +#define        EXACTLY 8       /* str  Match this string. */
 796 +#define        NOTHING 9       /* no   Match empty string. */
 797 +#define        STAR    10      /* node Match this (simple) thing 0 or more times. */
 798 +#define        PLUS    11      /* node Match this (simple) thing 1 or more times. */
 799 +#define        OPEN    20      /* no   Mark this point in input as start of #n. */
 800 +                       /*      OPEN+1 is number 1, etc. */
 801 +#define        CLOSE   30      /* no   Analogous to OPEN. */
 802 +
 803 +/*
 804 + * Opcode notes:
 805 + *
 806 + * BRANCH      The set of branches constituting a single choice are hooked
 807 + *             together with their "next" pointers, since precedence prevents
 808 + *             anything being concatenated to any individual branch.  The
 809 + *             "next" pointer of the last BRANCH in a choice points to the
 810 + *             thing following the whole choice.  This is also where the
 811 + *             final "next" pointer of each individual branch points; each
 812 + *             branch starts with the operand node of a BRANCH node.
 813 + *
 814 + * BACK                Normal "next" pointers all implicitly point forward; BACK
 815 + *             exists to make loop structures possible.
 816 + *
 817 + * STAR,PLUS   '?', and complex '*' and '+', are implemented as circular
 818 + *             BRANCH structures using BACK.  Simple cases (one character
 819 + *             per match) are implemented with STAR and PLUS for speed
 820 + *             and to minimize recursive plunges.
 821 + *
 822 + * OPEN,CLOSE  ...are numbered at compile time.
 823 + */
 824 +
 825 +/*
 826 + * A node is one char of opcode followed by two chars of "next" pointer.
 827 + * "Next" pointers are stored as two 8-bit pieces, high order first.  The
 828 + * value is a positive offset from the opcode of the node containing it.
 829 + * An operand, if any, simply follows the node.  (Note that much of the
 830 + * code generation knows about this implicit relationship.)
 831 + *
 832 + * Using two bytes for the "next" pointer is vast overkill for most things,
 833 + * but allows patterns to get big without disasters.
 834 + */
 835 +#define        OP(p)   (*(p))
 836 +#define        NEXT(p) (((*((p)+1)&0377)<<8) + (*((p)+2)&0377))
 837 +#define        OPERAND(p)      ((p) + 3)
 838 +
 839 +/*
 840 + * See regmagic.h for one further detail of program structure.
 841 + */
 842 +
 843 +
 844 +/*
 845 + * Utility definitions.
 846 + */
 847 +#ifndef CHARBITS
 848 +#define        UCHARAT(p)      ((int)*(unsigned char *)(p))
 849 +#else
 850 +#define        UCHARAT(p)      ((int)*(p)&CHARBITS)
 851 +#endif
 852 +
 853 +#define        FAIL(m) { regerror(m); return(NULL); }
 854 +#define        ISMULT(c)       ((c) == '*' || (c) == '+' || (c) == '?')
 855 +#define        META    "^$.[()|?+*\\"
 856 +
 857 +/*
 858 + * Flags to be passed up and down.
 859 + */
 860 +#define        HASWIDTH        01      /* Known never to match null string. */
 861 +#define        SIMPLE          02      /* Simple enough to be STAR/PLUS operand. */
 862 +#define        SPSTART         04      /* Starts with * or +. */
 863 +#define        WORST           0       /* Worst case. */
 864 +
 865 +/*
 866 + * Global work variables for regcomp().
 867 + */
 868 +static char *regparse;         /* Input-scan pointer. */
 869 +static int regnpar;            /* () count. */
 870 +static char regdummy;
 871 +static char *regcode;          /* Code-emit pointer; &regdummy = don't. */
 872 +static long regsize;           /* Code size. */
 873 +
 874 +/*
 875 + * Forward declarations for regcomp()'s friends.
 876 + */
 877 +#ifndef STATIC
 878 +#define        STATIC  static
 879 +#endif
 880 +STATIC char *reg(int paren,int *flagp);
 881 +STATIC char *regbranch(int *flagp);
 882 +STATIC char *regpiece(int *flagp);
 883 +STATIC char *regatom(int *flagp);
 884 +STATIC char *regnode(char op);
 885 +STATIC char *regnext(char *p);
 886 +STATIC void regc(char b);
 887 +STATIC void reginsert(char op, char *opnd);
 888 +STATIC void regtail(char *p, char *val);
 889 +STATIC void regoptail(char *p, char *val);
 890 +
 891 +
 892 +__kernel_size_t my_strcspn(const char *s1,const char *s2)
 893 +{
 894 +        char *scan1;
 895 +        char *scan2;
 896 +        int count;
 897 +
 898 +        count = 0;
 899 +        for (scan1 = (char *)s1; *scan1 != '\0'; scan1++) {
 900 +                for (scan2 = (char *)s2; *scan2 != '\0';)       /* ++ moved down. */
 901 +                        if (*scan1 == *scan2++)
 902 +                                return(count);
 903 +                count++;
 904 +        }
 905 +        return(count);
 906 +}
 907 +
 908 +/*
 909 + - regcomp - compile a regular expression into internal code
 910 + *
 911 + * We can't allocate space until we know how big the compiled form will be,
 912 + * but we can't compile it (and thus know how big it is) until we've got a
 913 + * place to put the code.  So we cheat:  we compile it twice, once with code
 914 + * generation turned off and size counting turned on, and once "for real".
 915 + * This also means that we don't allocate space until we are sure that the
 916 + * thing really will compile successfully, and we never have to move the
 917 + * code and thus invalidate pointers into it.  (Note that it has to be in
 918 + * one piece because free() must be able to free it all.)
 919 + *
 920 + * Beware that the optimization-preparation code in here knows about some
 921 + * of the structure of the compiled regexp.
 922 + */
 923 +regexp *
 924 +regcomp(char *exp,int *patternsize)
 925 +{
 926 +       register regexp *r;
 927 +       register char *scan;
 928 +       register char *longest;
 929 +       register int len;
 930 +       int flags;
 931 +       /* commented out by ethan
 932 +          extern char *malloc();
 933 +       */
 934 +
 935 +       if (exp == NULL)
 936 +               FAIL("NULL argument");
 937 +
 938 +       /* First pass: determine size, legality. */
 939 +       regparse = exp;
 940 +       regnpar = 1;
 941 +       regsize = 0L;
 942 +       regcode = &regdummy;
 943 +       regc(MAGIC);
 944 +       if (reg(0, &flags) == NULL)
 945 +               return(NULL);
 946 +
 947 +       /* Small enough for pointer-storage convention? */
 948 +       if (regsize >= 32767L)          /* Probably could be 65535L. */
 949 +               FAIL("regexp too big");
 950 +
 951 +       /* Allocate space. */
 952 +       *patternsize=sizeof(regexp) + (unsigned)regsize;
 953 +       r = (regexp *)malloc(sizeof(regexp) + (unsigned)regsize);
 954 +       if (r == NULL)
 955 +               FAIL("out of space");
 956 +
 957 +       /* Second pass: emit code. */
 958 +       regparse = exp;
 959 +       regnpar = 1;
 960 +       regcode = r->program;
 961 +       regc(MAGIC);
 962 +       if (reg(0, &flags) == NULL)
 963 +               return(NULL);
 964 +
 965 +       /* Dig out information for optimizations. */
 966 +       r->regstart = '\0';     /* Worst-case defaults. */
 967 +       r->reganch = 0;
 968 +       r->regmust = NULL;
 969 +       r->regmlen = 0;
 970 +       scan = r->program+1;                    /* First BRANCH. */
 971 +       if (OP(regnext(scan)) == END) {         /* Only one top-level choice. */
 972 +               scan = OPERAND(scan);
 973 +
 974 +               /* Starting-point info. */
 975 +               if (OP(scan) == EXACTLY)
 976 +                       r->regstart = *OPERAND(scan);
 977 +               else if (OP(scan) == BOL)
 978 +                       r->reganch++;
 979 +
 980 +               /*
 981 +                * If there's something expensive in the r.e., find the
 982 +                * longest literal string that must appear and make it the
 983 +                * regmust.  Resolve ties in favor of later strings, since
 984 +                * the regstart check works with the beginning of the r.e.
 985 +                * and avoiding duplication strengthens checking.  Not a
 986 +                * strong reason, but sufficient in the absence of others.
 987 +                */
 988 +               if (flags&SPSTART) {
 989 +                       longest = NULL;
 990 +                       len = 0;
 991 +                       for (; scan != NULL; scan = regnext(scan))
 992 +                               if (OP(scan) == EXACTLY && strlen(OPERAND(scan)) >= len) {
 993 +                                       longest = OPERAND(scan);
 994 +                                       len = strlen(OPERAND(scan));
 995 +                               }
 996 +                       r->regmust = longest;
 997 +                       r->regmlen = len;
 998 +               }
 999 +       }
1000 +
1001 +       return(r);
1002 +}
1003 +
1004 +/*
1005 + - reg - regular expression, i.e. main body or parenthesized thing
1006 + *
1007 + * Caller must absorb opening parenthesis.
1008 + *
1009 + * Combining parenthesis handling with the base level of regular expression
1010 + * is a trifle forced, but the need to tie the tails of the branches to what
1011 + * follows makes it hard to avoid.
1012 + */
1013 +static char *
1014 +reg(int paren, int *flagp /* Parenthesized? */ )
1015 +{
1016 +       register char *ret;
1017 +       register char *br;
1018 +       register char *ender;
1019 +       register int parno = 0; /* 0 makes gcc happy */
1020 +       int flags;
1021 +
1022 +       *flagp = HASWIDTH;      /* Tentatively. */
1023 +
1024 +       /* Make an OPEN node, if parenthesized. */
1025 +       if (paren) {
1026 +               if (regnpar >= NSUBEXP)
1027 +                       FAIL("too many ()");
1028 +               parno = regnpar;
1029 +               regnpar++;
1030 +               ret = regnode(OPEN+parno);
1031 +       } else
1032 +               ret = NULL;
1033 +
1034 +       /* Pick up the branches, linking them together. */
1035 +       br = regbranch(&flags);
1036 +       if (br == NULL)
1037 +               return(NULL);
1038 +       if (ret != NULL)
1039 +               regtail(ret, br);       /* OPEN -> first. */
1040 +       else
1041 +               ret = br;
1042 +       if (!(flags&HASWIDTH))
1043 +               *flagp &= ~HASWIDTH;
1044 +       *flagp |= flags&SPSTART;
1045 +       while (*regparse == '|') {
1046 +               regparse++;
1047 +               br = regbranch(&flags);
1048 +               if (br == NULL)
1049 +                       return(NULL);
1050 +               regtail(ret, br);       /* BRANCH -> BRANCH. */
1051 +               if (!(flags&HASWIDTH))
1052 +                       *flagp &= ~HASWIDTH;
1053 +               *flagp |= flags&SPSTART;
1054 +       }
1055 +
1056 +       /* Make a closing node, and hook it on the end. */
1057 +       ender = regnode((paren) ? CLOSE+parno : END);
1058 +       regtail(ret, ender);
1059 +
1060 +       /* Hook the tails of the branches to the closing node. */
1061 +       for (br = ret; br != NULL; br = regnext(br))
1062 +               regoptail(br, ender);
1063 +
1064 +       /* Check for proper termination. */
1065 +       if (paren && *regparse++ != ')') {
1066 +               FAIL("unmatched ()");
1067 +       } else if (!paren && *regparse != '\0') {
1068 +               if (*regparse == ')') {
1069 +                       FAIL("unmatched ()");
1070 +               } else
1071 +                       FAIL("junk on end");    /* "Can't happen". */
1072 +               /* NOTREACHED */
1073 +       }
1074 +
1075 +       return(ret);
1076 +}
1077 +
1078 +/*
1079 + - regbranch - one alternative of an | operator
1080 + *
1081 + * Implements the concatenation operator.
1082 + */
1083 +static char *
1084 +regbranch(int *flagp)
1085 +{
1086 +       register char *ret;
1087 +       register char *chain;
1088 +       register char *latest;
1089 +       int flags;
1090 +
1091 +       *flagp = WORST;         /* Tentatively. */
1092 +
1093 +       ret = regnode(BRANCH);
1094 +       chain = NULL;
1095 +       while (*regparse != '\0' && *regparse != '|' && *regparse != ')') {
1096 +               latest = regpiece(&flags);
1097 +               if (latest == NULL)
1098 +                       return(NULL);
1099 +               *flagp |= flags&HASWIDTH;
1100 +               if (chain == NULL)      /* First piece. */
1101 +                       *flagp |= flags&SPSTART;
1102 +               else
1103 +                       regtail(chain, latest);
1104 +               chain = latest;
1105 +       }
1106 +       if (chain == NULL)      /* Loop ran zero times. */
1107 +               (void) regnode(NOTHING);
1108 +
1109 +       return(ret);
1110 +}
1111 +
1112 +/*
1113 + - regpiece - something followed by possible [*+?]
1114 + *
1115 + * Note that the branching code sequences used for ? and the general cases
1116 + * of * and + are somewhat optimized:  they use the same NOTHING node as
1117 + * both the endmarker for their branch list and the body of the last branch.
1118 + * It might seem that this node could be dispensed with entirely, but the
1119 + * endmarker role is not redundant.
1120 + */
1121 +static char *
1122 +regpiece(int *flagp)
1123 +{
1124 +       register char *ret;
1125 +       register char op;
1126 +       register char *next;
1127 +       int flags;
1128 +
1129 +       ret = regatom(&flags);
1130 +       if (ret == NULL)
1131 +               return(NULL);
1132 +
1133 +       op = *regparse;
1134 +       if (!ISMULT(op)) {
1135 +               *flagp = flags;
1136 +               return(ret);
1137 +       }
1138 +
1139 +       if (!(flags&HASWIDTH) && op != '?')
1140 +               FAIL("*+ operand could be empty");
1141 +       *flagp = (op != '+') ? (WORST|SPSTART) : (WORST|HASWIDTH);
1142 +
1143 +       if (op == '*' && (flags&SIMPLE))
1144 +               reginsert(STAR, ret);
1145 +       else if (op == '*') {
1146 +               /* Emit x* as (x&|), where & means "self". */
1147 +               reginsert(BRANCH, ret);                 /* Either x */
1148 +               regoptail(ret, regnode(BACK));          /* and loop */
1149 +               regoptail(ret, ret);                    /* back */
1150 +               regtail(ret, regnode(BRANCH));          /* or */
1151 +               regtail(ret, regnode(NOTHING));         /* null. */
1152 +       } else if (op == '+' && (flags&SIMPLE))
1153 +               reginsert(PLUS, ret);
1154 +       else if (op == '+') {
1155 +               /* Emit x+ as x(&|), where & means "self". */
1156 +               next = regnode(BRANCH);                 /* Either */
1157 +               regtail(ret, next);
1158 +               regtail(regnode(BACK), ret);            /* loop back */
1159 +               regtail(next, regnode(BRANCH));         /* or */
1160 +               regtail(ret, regnode(NOTHING));         /* null. */
1161 +       } else if (op == '?') {
1162 +               /* Emit x? as (x|) */
1163 +               reginsert(BRANCH, ret);                 /* Either x */
1164 +               regtail(ret, regnode(BRANCH));          /* or */
1165 +               next = regnode(NOTHING);                /* null. */
1166 +               regtail(ret, next);
1167 +               regoptail(ret, next);
1168 +       }
1169 +       regparse++;
1170 +       if (ISMULT(*regparse))
1171 +               FAIL("nested *?+");
1172 +
1173 +       return(ret);
1174 +}
1175 +
1176 +/*
1177 + - regatom - the lowest level
1178 + *
1179 + * Optimization:  gobbles an entire sequence of ordinary characters so that
1180 + * it can turn them into a single node, which is smaller to store and
1181 + * faster to run.  Backslashed characters are exceptions, each becoming a
1182 + * separate node; the code is simpler that way and it's not worth fixing.
1183 + */
1184 +static char *
1185 +regatom(int *flagp)
1186 +{
1187 +       register char *ret;
1188 +       int flags;
1189 +
1190 +       *flagp = WORST;         /* Tentatively. */
1191 +
1192 +       switch (*regparse++) {
1193 +       case '^':
1194 +               ret = regnode(BOL);
1195 +               break;
1196 +       case '$':
1197 +               ret = regnode(EOL);
1198 +               break;
1199 +       case '.':
1200 +               ret = regnode(ANY);
1201 +               *flagp |= HASWIDTH|SIMPLE;
1202 +               break;
1203 +       case '[': {
1204 +                       register int class;
1205 +                       register int classend;
1206 +
1207 +                       if (*regparse == '^') { /* Complement of range. */
1208 +                               ret = regnode(ANYBUT);
1209 +                               regparse++;
1210 +                       } else
1211 +                               ret = regnode(ANYOF);
1212 +                       if (*regparse == ']' || *regparse == '-')
1213 +                               regc(*regparse++);
1214 +                       while (*regparse != '\0' && *regparse != ']') {
1215 +                               if (*regparse == '-') {
1216 +                                       regparse++;
1217 +                                       if (*regparse == ']' || *regparse == '\0')
1218 +                                               regc('-');
1219 +                                       else {
1220 +                                               class = UCHARAT(regparse-2)+1;
1221 +                                               classend = UCHARAT(regparse);
1222 +                                               if (class > classend+1)
1223 +                                                       FAIL("invalid [] range");
1224 +                                               for (; class <= classend; class++)
1225 +                                                       regc(class);
1226 +                                               regparse++;
1227 +                                       }
1228 +                               } else
1229 +                                       regc(*regparse++);
1230 +                       }
1231 +                       regc('\0');
1232 +                       if (*regparse != ']')
1233 +                               FAIL("unmatched []");
1234 +                       regparse++;
1235 +                       *flagp |= HASWIDTH|SIMPLE;
1236 +               }
1237 +               break;
1238 +       case '(':
1239 +               ret = reg(1, &flags);
1240 +               if (ret == NULL)
1241 +                       return(NULL);
1242 +               *flagp |= flags&(HASWIDTH|SPSTART);
1243 +               break;
1244 +       case '\0':
1245 +       case '|':
1246 +       case ')':
1247 +               FAIL("internal urp");   /* Supposed to be caught earlier. */
1248 +               break;
1249 +       case '?':
1250 +       case '+':
1251 +       case '*':
1252 +               FAIL("?+* follows nothing");
1253 +               break;
1254 +       case '\\':
1255 +               if (*regparse == '\0')
1256 +                       FAIL("trailing \\");
1257 +               ret = regnode(EXACTLY);
1258 +               regc(*regparse++);
1259 +               regc('\0');
1260 +               *flagp |= HASWIDTH|SIMPLE;
1261 +               break;
1262 +       default: {
1263 +                       register int len;
1264 +                       register char ender;
1265 +
1266 +                       regparse--;
1267 +                       len = my_strcspn((const char *)regparse, (const char *)META);
1268 +                       if (len <= 0)
1269 +                               FAIL("internal disaster");
1270 +                       ender = *(regparse+len);
1271 +                       if (len > 1 && ISMULT(ender))
1272 +                               len--;          /* Back off clear of ?+* operand. */
1273 +                       *flagp |= HASWIDTH;
1274 +                       if (len == 1)
1275 +                               *flagp |= SIMPLE;
1276 +                       ret = regnode(EXACTLY);
1277 +                       while (len > 0) {
1278 +                               regc(*regparse++);
1279 +                               len--;
1280 +                       }
1281 +                       regc('\0');
1282 +               }
1283 +               break;
1284 +       }
1285 +
1286 +       return(ret);
1287 +}
1288 +
1289 +/*
1290 + - regnode - emit a node
1291 + */
1292 +static char *                  /* Location. */
1293 +regnode(char op)
1294 +{
1295 +       register char *ret;
1296 +       register char *ptr;
1297 +
1298 +       ret = regcode;
1299 +       if (ret == &regdummy) {
1300 +               regsize += 3;
1301 +               return(ret);
1302 +       }
1303 +
1304 +       ptr = ret;
1305 +       *ptr++ = op;
1306 +       *ptr++ = '\0';          /* Null "next" pointer. */
1307 +       *ptr++ = '\0';
1308 +       regcode = ptr;
1309 +
1310 +       return(ret);
1311 +}
1312 +
1313 +/*
1314 + - regc - emit (if appropriate) a byte of code
1315 + */
1316 +static void
1317 +regc(char b)
1318 +{
1319 +       if (regcode != &regdummy)
1320 +               *regcode++ = b;
1321 +       else
1322 +               regsize++;
1323 +}
1324 +
1325 +/*
1326 + - reginsert - insert an operator in front of already-emitted operand
1327 + *
1328 + * Means relocating the operand.
1329 + */
1330 +static void
1331 +reginsert(char op, char* opnd)
1332 +{
1333 +       register char *src;
1334 +       register char *dst;
1335 +       register char *place;
1336 +
1337 +       if (regcode == &regdummy) {
1338 +               regsize += 3;
1339 +               return;
1340 +       }
1341 +
1342 +       src = regcode;
1343 +       regcode += 3;
1344 +       dst = regcode;
1345 +       while (src > opnd)
1346 +               *--dst = *--src;
1347 +
1348 +       place = opnd;           /* Op node, where operand used to be. */
1349 +       *place++ = op;
1350 +       *place++ = '\0';
1351 +       *place++ = '\0';
1352 +}
1353 +
1354 +/*
1355 + - regtail - set the next-pointer at the end of a node chain
1356 + */
1357 +static void
1358 +regtail(char *p, char *val)
1359 +{
1360 +       register char *scan;
1361 +       register char *temp;
1362 +       register int offset;
1363 +
1364 +       if (p == &regdummy)
1365 +               return;
1366 +
1367 +       /* Find last node. */
1368 +       scan = p;
1369 +       for (;;) {
1370 +               temp = regnext(scan);
1371 +               if (temp == NULL)
1372 +                       break;
1373 +               scan = temp;
1374 +       }
1375 +
1376 +       if (OP(scan) == BACK)
1377 +               offset = scan - val;
1378 +       else
1379 +               offset = val - scan;
1380 +       *(scan+1) = (offset>>8)&0377;
1381 +       *(scan+2) = offset&0377;
1382 +}
1383 +
1384 +/*
1385 + - regoptail - regtail on operand of first argument; nop if operandless
1386 + */
1387 +static void
1388 +regoptail(char *p, char *val)
1389 +{
1390 +       /* "Operandless" and "op != BRANCH" are synonymous in practice. */
1391 +       if (p == NULL || p == &regdummy || OP(p) != BRANCH)
1392 +               return;
1393 +       regtail(OPERAND(p), val);
1394 +}
1395 +
1396 +/*
1397 + * regexec and friends
1398 + */
1399 +
1400 +/*
1401 + * Global work variables for regexec().
1402 + */
1403 +static char *reginput;         /* String-input pointer. */
1404 +static char *regbol;           /* Beginning of input, for ^ check. */
1405 +static char **regstartp;       /* Pointer to startp array. */
1406 +static char **regendp;         /* Ditto for endp. */
1407 +
1408 +/*
1409 + * Forwards.
1410 + */
1411 +STATIC int regtry(regexp *prog, char *string);
1412 +STATIC int regmatch(char *prog);
1413 +STATIC int regrepeat(char *p);
1414 +
1415 +#ifdef DEBUG
1416 +int regnarrate = 0;
1417 +void regdump();
1418 +STATIC char *regprop(char *op);
1419 +#endif
1420 +
1421 +/*
1422 + - regexec - match a regexp against a string
1423 + */
1424 +int
1425 +regexec(regexp *prog, char *string)
1426 +{
1427 +       register char *s;
1428 +
1429 +       /* Be paranoid... */
1430 +       if (prog == NULL || string == NULL) {
1431 +               printk("<3>Regexp: NULL parameter\n");
1432 +               return(0);
1433 +       }
1434 +
1435 +       /* Check validity of program. */
1436 +       if (UCHARAT(prog->program) != MAGIC) {
1437 +               printk("<3>Regexp: corrupted program\n");
1438 +               return(0);
1439 +       }
1440 +
1441 +       /* If there is a "must appear" string, look for it. */
1442 +       if (prog->regmust != NULL) {
1443 +               s = string;
1444 +               while ((s = strchr(s, prog->regmust[0])) != NULL) {
1445 +                       if (strncmp(s, prog->regmust, prog->regmlen) == 0)
1446 +                               break;  /* Found it. */
1447 +                       s++;
1448 +               }
1449 +               if (s == NULL)  /* Not present. */
1450 +                       return(0);
1451 +       }
1452 +
1453 +       /* Mark beginning of line for ^ . */
1454 +       regbol = string;
1455 +
1456 +       /* Simplest case:  anchored match need be tried only once. */
1457 +       if (prog->reganch)
1458 +               return(regtry(prog, string));
1459 +
1460 +       /* Messy cases:  unanchored match. */
1461 +       s = string;
1462 +       if (prog->regstart != '\0')
1463 +               /* We know what char it must start with. */
1464 +               while ((s = strchr(s, prog->regstart)) != NULL) {
1465 +                       if (regtry(prog, s))
1466 +                               return(1);
1467 +                       s++;
1468 +               }
1469 +       else
1470 +               /* We don't -- general case. */
1471 +               do {
1472 +                       if (regtry(prog, s))
1473 +                               return(1);
1474 +               } while (*s++ != '\0');
1475 +
1476 +       /* Failure. */
1477 +       return(0);
1478 +}
1479 +
1480 +/*
1481 + - regtry - try match at specific point
1482 + */
1483 +static int                     /* 0 failure, 1 success */
1484 +regtry(regexp *prog, char *string)
1485 +{
1486 +       register int i;
1487 +       register char **sp;
1488 +       register char **ep;
1489 +
1490 +       reginput = string;
1491 +       regstartp = prog->startp;
1492 +       regendp = prog->endp;
1493 +
1494 +       sp = prog->startp;
1495 +       ep = prog->endp;
1496 +       for (i = NSUBEXP; i > 0; i--) {
1497 +               *sp++ = NULL;
1498 +               *ep++ = NULL;
1499 +       }
1500 +       if (regmatch(prog->program + 1)) {
1501 +               prog->startp[0] = string;
1502 +               prog->endp[0] = reginput;
1503 +               return(1);
1504 +       } else
1505 +               return(0);
1506 +}
1507 +
1508 +/*
1509 + - regmatch - main matching routine
1510 + *
1511 + * Conceptually the strategy is simple:  check to see whether the current
1512 + * node matches, call self recursively to see whether the rest matches,
1513 + * and then act accordingly.  In practice we make some effort to avoid
1514 + * recursion, in particular by going through "ordinary" nodes (that don't
1515 + * need to know whether the rest of the match failed) by a loop instead of
1516 + * by recursion.
1517 + */
1518 +static int                     /* 0 failure, 1 success */
1519 +regmatch(char *prog)
1520 +{
1521 +       register char *scan = prog; /* Current node. */
1522 +       char *next;                 /* Next node. */
1523 +
1524 +#ifdef DEBUG
1525 +       if (scan != NULL && regnarrate)
1526 +               fprintf(stderr, "%s(\n", regprop(scan));
1527 +#endif
1528 +       while (scan != NULL) {
1529 +#ifdef DEBUG
1530 +               if (regnarrate)
1531 +                       fprintf(stderr, "%s...\n", regprop(scan));
1532 +#endif
1533 +               next = regnext(scan);
1534 +
1535 +               switch (OP(scan)) {
1536 +               case BOL:
1537 +                       if (reginput != regbol)
1538 +                               return(0);
1539 +                       break;
1540 +               case EOL:
1541 +                       if (*reginput != '\0')
1542 +                               return(0);
1543 +                       break;
1544 +               case ANY:
1545 +                       if (*reginput == '\0')
1546 +                               return(0);
1547 +                       reginput++;
1548 +                       break;
1549 +               case EXACTLY: {
1550 +                               register int len;
1551 +                               register char *opnd;
1552 +
1553 +                               opnd = OPERAND(scan);
1554 +                               /* Inline the first character, for speed. */
1555 +                               if (*opnd != *reginput)
1556 +                                       return(0);
1557 +                               len = strlen(opnd);
1558 +                               if (len > 1 && strncmp(opnd, reginput, len) != 0)
1559 +                                       return(0);
1560 +                               reginput += len;
1561 +                       }
1562 +                       break;
1563 +               case ANYOF:
1564 +                       if (*reginput == '\0' || strchr(OPERAND(scan), *reginput) == NULL)
1565 +                               return(0);
1566 +                       reginput++;
1567 +                       break;
1568 +               case ANYBUT:
1569 +                       if (*reginput == '\0' || strchr(OPERAND(scan), *reginput) != NULL)
1570 +                               return(0);
1571 +                       reginput++;
1572 +                       break;
1573 +               case NOTHING:
1574 +               case BACK:
1575 +                       break;
1576 +               case OPEN+1:
1577 +               case OPEN+2:
1578 +               case OPEN+3:
1579 +               case OPEN+4:
1580 +               case OPEN+5:
1581 +               case OPEN+6:
1582 +               case OPEN+7:
1583 +               case OPEN+8:
1584 +               case OPEN+9: {
1585 +                               register int no;
1586 +                               register char *save;
1587 +
1588 +                               no = OP(scan) - OPEN;
1589 +                               save = reginput;
1590 +
1591 +                               if (regmatch(next)) {
1592 +                                       /*
1593 +                                        * Don't set startp if some later
1594 +                                        * invocation of the same parentheses
1595 +                                        * already has.
1596 +                                        */
1597 +                                       if (regstartp[no] == NULL)
1598 +                                               regstartp[no] = save;
1599 +                                       return(1);
1600 +                               } else
1601 +                                       return(0);
1602 +                       }
1603 +                       break;
1604 +               case CLOSE+1:
1605 +               case CLOSE+2:
1606 +               case CLOSE+3:
1607 +               case CLOSE+4:
1608 +               case CLOSE+5:
1609 +               case CLOSE+6:
1610 +               case CLOSE+7:
1611 +               case CLOSE+8:
1612 +               case CLOSE+9:
1613 +                       {
1614 +                               register int no;
1615 +                               register char *save;
1616 +
1617 +                               no = OP(scan) - CLOSE;
1618 +                               save = reginput;
1619 +
1620 +                               if (regmatch(next)) {
1621 +                                       /*
1622 +                                        * Don't set endp if some later
1623 +                                        * invocation of the same parentheses
1624 +                                        * already has.
1625 +                                        */
1626 +                                       if (regendp[no] == NULL)
1627 +                                               regendp[no] = save;
1628 +                                       return(1);
1629 +                               } else
1630 +                                       return(0);
1631 +                       }
1632 +                       break;
1633 +               case BRANCH: {
1634 +                               register char *save;
1635 +
1636 +                               if (OP(next) != BRANCH)         /* No choice. */
1637 +                                       next = OPERAND(scan);   /* Avoid recursion. */
1638 +                               else {
1639 +                                       do {
1640 +                                               save = reginput;
1641 +                                               if (regmatch(OPERAND(scan)))
1642 +                                                       return(1);
1643 +                                               reginput = save;
1644 +                                               scan = regnext(scan);
1645 +                                       } while (scan != NULL && OP(scan) == BRANCH);
1646 +                                       return(0);
1647 +                                       /* NOTREACHED */
1648 +                               }
1649 +                       }
1650 +                       break;
1651 +               case STAR:
1652 +               case PLUS: {
1653 +                               register char nextch;
1654 +                               register int no;
1655 +                               register char *save;
1656 +                               register int min;
1657 +
1658 +                               /*
1659 +                                * Lookahead to avoid useless match attempts
1660 +                                * when we know what character comes next.
1661 +                                */
1662 +                               nextch = '\0';
1663 +                               if (OP(next) == EXACTLY)
1664 +                                       nextch = *OPERAND(next);
1665 +                               min = (OP(scan) == STAR) ? 0 : 1;
1666 +                               save = reginput;
1667 +                               no = regrepeat(OPERAND(scan));
1668 +                               while (no >= min) {
1669 +                                       /* If it could work, try it. */
1670 +                                       if (nextch == '\0' || *reginput == nextch)
1671 +                                               if (regmatch(next))
1672 +                                                       return(1);
1673 +                                       /* Couldn't or didn't -- back up. */
1674 +                                       no--;
1675 +                                       reginput = save + no;
1676 +                               }
1677 +                               return(0);
1678 +                       }
1679 +                       break;
1680 +               case END:
1681 +                       return(1);      /* Success! */
1682 +                       break;
1683 +               default:
1684 +                       printk("<3>Regexp: memory corruption\n");
1685 +                       return(0);
1686 +                       break;
1687 +               }
1688 +
1689 +               scan = next;
1690 +       }
1691 +
1692 +       /*
1693 +        * We get here only if there's trouble -- normally "case END" is
1694 +        * the terminating point.
1695 +        */
1696 +       printk("<3>Regexp: corrupted pointers\n");
1697 +       return(0);
1698 +}
1699 +
1700 +/*
1701 + - regrepeat - repeatedly match something simple, report how many
1702 + */
1703 +static int
1704 +regrepeat(char *p)
1705 +{
1706 +       register int count = 0;
1707 +       register char *scan;
1708 +       register char *opnd;
1709 +
1710 +       scan = reginput;
1711 +       opnd = OPERAND(p);
1712 +       switch (OP(p)) {
1713 +       case ANY:
1714 +               count = strlen(scan);
1715 +               scan += count;
1716 +               break;
1717 +       case EXACTLY:
1718 +               while (*opnd == *scan) {
1719 +                       count++;
1720 +                       scan++;
1721 +               }
1722 +               break;
1723 +       case ANYOF:
1724 +               while (*scan != '\0' && strchr(opnd, *scan) != NULL) {
1725 +                       count++;
1726 +                       scan++;
1727 +               }
1728 +               break;
1729 +       case ANYBUT:
1730 +               while (*scan != '\0' && strchr(opnd, *scan) == NULL) {
1731 +                       count++;
1732 +                       scan++;
1733 +               }
1734 +               break;
1735 +       default:                /* Oh dear.  Called inappropriately. */
1736 +               printk("<3>Regexp: internal foulup\n");
1737 +               count = 0;      /* Best compromise. */
1738 +               break;
1739 +       }
1740 +       reginput = scan;
1741 +
1742 +       return(count);
1743 +}
1744 +
1745 +/*
1746 + - regnext - dig the "next" pointer out of a node
1747 + */
1748 +static char*
1749 +regnext(char *p)
1750 +{
1751 +       register int offset;
1752 +
1753 +       if (p == &regdummy)
1754 +               return(NULL);
1755 +
1756 +       offset = NEXT(p);
1757 +       if (offset == 0)
1758 +               return(NULL);
1759 +
1760 +       if (OP(p) == BACK)
1761 +               return(p-offset);
1762 +       else
1763 +               return(p+offset);
1764 +}
1765 +
1766 +#ifdef DEBUG
1767 +
1768 +STATIC char *regprop();
1769 +
1770 +/*
1771 + - regdump - dump a regexp onto stdout in vaguely comprehensible form
1772 + */
1773 +void
1774 +regdump(regexp *r)
1775 +{
1776 +       register char *s;
1777 +       register char op = EXACTLY;     /* Arbitrary non-END op. */
1778 +       register char *next;
1779 +       /* extern char *strchr(); */
1780 +
1781 +
1782 +       s = r->program + 1;
1783 +       while (op != END) {     /* While that wasn't END last time... */
1784 +               op = OP(s);
1785 +               printf("%2d%s", s-r->program, regprop(s));      /* Where, what. */
1786 +               next = regnext(s);
1787 +               if (next == NULL)               /* Next ptr. */
1788 +                       printf("(0)");
1789 +               else
1790 +                       printf("(%d)", (s-r->program)+(next-s));
1791 +               s += 3;
1792 +               if (op == ANYOF || op == ANYBUT || op == EXACTLY) {
1793 +                       /* Literal string, where present. */
1794 +                       while (*s != '\0') {
1795 +                               putchar(*s);
1796 +                               s++;
1797 +                       }
1798 +                       s++;
1799 +               }
1800 +               putchar('\n');
1801 +       }
1802 +
1803 +       /* Header fields of interest. */
1804 +       if (r->regstart != '\0')
1805 +               printf("start `%c' ", r->regstart);
1806 +       if (r->reganch)
1807 +               printf("anchored ");
1808 +       if (r->regmust != NULL)
1809 +               printf("must have \"%s\"", r->regmust);
1810 +       printf("\n");
1811 +}
1812 +
1813 +/*
1814 + - regprop - printable representation of opcode
1815 + */
1816 +static char *
1817 +regprop(char *op)
1818 +{
1819 +#define BUFLEN 50
1820 +       register char *p;
1821 +       static char buf[BUFLEN];
1822 +
1823 +       strcpy(buf, ":");
1824 +
1825 +       switch (OP(op)) {
1826 +       case BOL:
1827 +               p = "BOL";
1828 +               break;
1829 +       case EOL:
1830 +               p = "EOL";
1831 +               break;
1832 +       case ANY:
1833 +               p = "ANY";
1834 +               break;
1835 +       case ANYOF:
1836 +               p = "ANYOF";
1837 +               break;
1838 +       case ANYBUT:
1839 +               p = "ANYBUT";
1840 +               break;
1841 +       case BRANCH:
1842 +               p = "BRANCH";
1843 +               break;
1844 +       case EXACTLY:
1845 +               p = "EXACTLY";
1846 +               break;
1847 +       case NOTHING:
1848 +               p = "NOTHING";
1849 +               break;
1850 +       case BACK:
1851 +               p = "BACK";
1852 +               break;
1853 +       case END:
1854 +               p = "END";
1855 +               break;
1856 +       case OPEN+1:
1857 +       case OPEN+2:
1858 +       case OPEN+3:
1859 +       case OPEN+4:
1860 +       case OPEN+5:
1861 +       case OPEN+6:
1862 +       case OPEN+7:
1863 +       case OPEN+8:
1864 +       case OPEN+9:
1865 +               snprintf(buf+strlen(buf),BUFLEN-strlen(buf), "OPEN%d", OP(op)-OPEN);
1866 +               p = NULL;
1867 +               break;
1868 +       case CLOSE+1:
1869 +       case CLOSE+2:
1870 +       case CLOSE+3:
1871 +       case CLOSE+4:
1872 +       case CLOSE+5:
1873 +       case CLOSE+6:
1874 +       case CLOSE+7:
1875 +       case CLOSE+8:
1876 +       case CLOSE+9:
1877 +               snprintf(buf+strlen(buf),BUFLEN-strlen(buf), "CLOSE%d", OP(op)-CLOSE);
1878 +               p = NULL;
1879 +               break;
1880 +       case STAR:
1881 +               p = "STAR";
1882 +               break;
1883 +       case PLUS:
1884 +               p = "PLUS";
1885 +               break;
1886 +       default:
1887 +               printk("<3>Regexp: corrupted opcode\n");
1888 +               break;
1889 +       }
1890 +       if (p != NULL)
1891 +               strncat(buf, p, BUFLEN-strlen(buf));
1892 +       return(buf);
1893 +}
1894 +#endif
1895 +
1896 +
1897 --- /dev/null
1898 +++ b/net/ipv4/netfilter/regexp/regexp.h
1899 @@ -0,0 +1,40 @@
1900 +/*
1901 + * Definitions etc. for regexp(3) routines.
1902 + *
1903 + * Caveat:  this is V8 regexp(3) [actually, a reimplementation thereof],
1904 + * not the System V one.
1905 + */
1906 +
1907 +#ifndef REGEXP_H
1908 +#define REGEXP_H
1909 +
1910 +/*
1911 +http://www.opensource.apple.com/darwinsource/10.3/expect-1/expect/expect.h ,
1912 +which contains a version of this library, says:
1913 +
1914 + *
1915 + * NSUBEXP must be at least 10, and no greater than 117 or the parser
1916 + * will not work properly.
1917 + *
1918 +
1919 +However, it looks rather like this library is limited to 10.  If you think
1920 +otherwise, let us know.
1921 +*/
1922 +
1923 +#define NSUBEXP  10
1924 +typedef struct regexp {
1925 +       char *startp[NSUBEXP];
1926 +       char *endp[NSUBEXP];
1927 +       char regstart;          /* Internal use only. */
1928 +       char reganch;           /* Internal use only. */
1929 +       char *regmust;          /* Internal use only. */
1930 +       int regmlen;            /* Internal use only. */
1931 +       char program[1];        /* Unwarranted chumminess with compiler. */
1932 +} regexp;
1933 +
1934 +regexp * regcomp(char *exp, int *patternsize);
1935 +int regexec(regexp *prog, char *string);
1936 +void regsub(regexp *prog, char *source, char *dest);
1937 +void regerror(char *s);
1938 +
1939 +#endif
1940 --- /dev/null
1941 +++ b/net/ipv4/netfilter/regexp/regmagic.h
1942 @@ -0,0 +1,5 @@
1943 +/*
1944 + * The first byte of the regexp internal "program" is actually this magic
1945 + * number; the start node begins in the second byte.
1946 + */
1947 +#define        MAGIC   0234
1948 --- /dev/null
1949 +++ b/net/ipv4/netfilter/regexp/regsub.c
1950 @@ -0,0 +1,95 @@
1951 +/*
1952 + * regsub
1953 + * @(#)regsub.c        1.3 of 2 April 86
1954 + *
1955 + *     Copyright (c) 1986 by University of Toronto.
1956 + *     Written by Henry Spencer.  Not derived from licensed software.
1957 + *
1958 + *     Permission is granted to anyone to use this software for any
1959 + *     purpose on any computer system, and to redistribute it freely,
1960 + *     subject to the following restrictions:
1961 + *
1962 + *     1. The author is not responsible for the consequences of use of
1963 + *             this software, no matter how awful, even if they arise
1964 + *             from defects in it.
1965 + *
1966 + *     2. The origin of this software must not be misrepresented, either
1967 + *             by explicit claim or by omission.
1968 + *
1969 + *     3. Altered versions must be plainly marked as such, and must not
1970 + *             be misrepresented as being the original software.
1971 + *
1972 + *
1973 + * This code was modified by Ethan Sommer to work within the kernel
1974 + * (it now uses kmalloc etc..)
1975 + *
1976 + */
1977 +#include "regexp.h"
1978 +#include "regmagic.h"
1979 +#include <linux/string.h>
1980 +
1981 +
1982 +#ifndef CHARBITS
1983 +#define        UCHARAT(p)      ((int)*(unsigned char *)(p))
1984 +#else
1985 +#define        UCHARAT(p)      ((int)*(p)&CHARBITS)
1986 +#endif
1987 +
1988 +#if 0
1989 +//void regerror(char * s)
1990 +//{
1991 +//        printk("regexp(3): %s", s);
1992 +//        /* NOTREACHED */
1993 +//}
1994 +#endif
1995 +
1996 +/*
1997 + - regsub - perform substitutions after a regexp match
1998 + */
1999 +void
2000 +regsub(regexp * prog, char * source, char * dest)
2001 +{
2002 +       register char *src;
2003 +       register char *dst;
2004 +       register char c;
2005 +       register int no;
2006 +       register int len;
2007 +
2008 +       /* Not necessary and gcc doesn't like it -MLS */
2009 +       /*extern char *strncpy();*/
2010 +
2011 +       if (prog == NULL || source == NULL || dest == NULL) {
2012 +               regerror("NULL parm to regsub");
2013 +               return;
2014 +       }
2015 +       if (UCHARAT(prog->program) != MAGIC) {
2016 +               regerror("damaged regexp fed to regsub");
2017 +               return;
2018 +       }
2019 +
2020 +       src = source;
2021 +       dst = dest;
2022 +       while ((c = *src++) != '\0') {
2023 +               if (c == '&')
2024 +                       no = 0;
2025 +               else if (c == '\\' && '0' <= *src && *src <= '9')
2026 +                       no = *src++ - '0';
2027 +               else
2028 +                       no = -1;
2029 +
2030 +               if (no < 0) {   /* Ordinary character. */
2031 +                       if (c == '\\' && (*src == '\\' || *src == '&'))
2032 +                               c = *src++;
2033 +                       *dst++ = c;
2034 +               } else if (prog->startp[no] != NULL && prog->endp[no] != NULL) {
2035 +                       len = prog->endp[no] - prog->startp[no];
2036 +                       (void) strncpy(dst, prog->startp[no], len);
2037 +                       dst += len;
2038 +                       if (len != 0 && *(dst-1) == '\0') {     /* strncpy hit NUL. */
2039 +                               regerror("damaged match string");
2040 +                               return;
2041 +                       }
2042 +               }
2043 +       }
2044 +       *dst++ = '\0';
2045 +}