package/iptables/patches/1.3.8/002-layer7_2.17.patch

   1 Index: iptables-1.3.8/extensions/.layer7-test
   2 ===================================================================
   3 --- /dev/null
   4 +++ iptables-1.3.8/extensions/.layer7-test
   5 @@ -0,0 +1,2 @@
   6 +#! /bin/sh
   7 +[ -f $KERNEL_DIR/include/linux/netfilter_ipv4/ipt_layer7.h ] && echo layer7
   8 Index: iptables-1.3.8/extensions/libipt_layer7.c
   9 ===================================================================
  10 --- /dev/null
  11 +++ iptables-1.3.8/extensions/libipt_layer7.c
  12 @@ -0,0 +1,394 @@
  13 +/*
  14 +   Shared library add-on to iptables to add layer 7 matching support.
  15 +
  16 +   By Matthew Strait <quadong@users.sf.net>, Oct 2003.
  17 +
  18 +   http://l7-filter.sf.net
  19 +
  20 +   This program is free software; you can redistribute it and/or
  21 +   modify it under the terms of the GNU General Public License
  22 +   as published by the Free Software Foundation; either version
  23 +   2 of the License, or (at your option) any later version.
  24 +   http://www.gnu.org/licenses/gpl.txt
  25 +
  26 +   Based on libipt_string.c (C) 2000 Emmanuel Roger <winfield@freegates.be>
  27 +*/
  28 +
  29 +#define _GNU_SOURCE
  30 +#include <stdio.h>
  31 +#include <netdb.h>
  32 +#include <string.h>
  33 +#include <stdlib.h>
  34 +#include <getopt.h>
  35 +#include <ctype.h>
  36 +#include <dirent.h>
  37 +
  38 +#include <iptables.h>
  39 +#include <linux/netfilter_ipv4/ipt_layer7.h>
  40 +
  41 +#define MAX_FN_LEN 256
  42 +
  43 +static char l7dir[MAX_FN_LEN] = "\0";
  44 +
  45 +/* Function which prints out usage message. */
  46 +static void help(void)
  47 +{
  48 +       printf(
  49 +       "LAYER7 match v%s options:\n"
  50 +       "--l7dir <directory>  : Look for patterns here instead of /etc/l7-protocols/\n"
  51 +       "                       (--l7dir must be specified before --l7proto if used!)\n"
  52 +       "--l7proto [!] <name> : Match the protocol defined in /etc/l7-protocols/name.pat\n",
  53 +       IPTABLES_VERSION);
  54 +       fputc('\n', stdout);
  55 +}
  56 +
  57 +static struct option opts[] = {
  58 +       { .name = "l7proto", .has_arg = 1, .flag = 0, .val = '1' },
  59 +       { .name = "l7dir",   .has_arg = 1, .flag = 0, .val = '2' },
  60 +       { .name = 0 }
  61 +};
  62 +
  63 +/* reads filename, puts protocol info into layer7_protocol_info, number of protocols to numprotos */
  64 +int parse_protocol_file(char * filename, const unsigned char * protoname, struct ipt_layer7_info *info)
  65 +{
  66 +       FILE * f;
  67 +       char * line = NULL;
  68 +       size_t len = 0;
  69 +
  70 +       enum { protocol, pattern, done } datatype = protocol;
  71 +
  72 +       f = fopen(filename, "r");
  73 +
  74 +       if(!f)
  75 +               return 0;
  76 +
  77 +       while(getline(&line, &len, f) != -1)
  78 +       {
  79 +               if(strlen(line) < 2 || line[0] == '#')
  80 +                       continue;
  81 +
  82 +               /* strip the pesky newline... */
  83 +               if(line[strlen(line) - 1] == '\n')
  84 +                       line[strlen(line) - 1] = '\0';
  85 +
  86 +               if(datatype == protocol)
  87 +               {
  88 +                       /* Ignore everything on the line beginning with the
  89 +                       first space or tab . For instance, this allows the
  90 +                       protocol line in http.pat to be "http " (or
  91 +                       "http I am so cool") instead of just "http". */
  92 +                       if(strchr(line, ' ')){
  93 +                               char * space = strchr(line, ' ');
  94 +                               space[0] = '\0';
  95 +                       }
  96 +                       if(strchr(line, '\t')){
  97 +                               char * space = strchr(line, '\t');
  98 +                               space[0] = '\0';
  99 +                       }
 100 +
 101 +                       /* sanity check.  First non-comment non-blank
 102 +                       line must be the same as the file name. */
 103 +                       if(strcmp(line, protoname))
 104 +                               exit_error(OTHER_PROBLEM,
 105 +                                       "Protocol name (%s) doesn't match file name (%s).  Bailing out\n",
 106 +                                       line, filename);
 107 +
 108 +                       if(strlen(line) >= MAX_PROTOCOL_LEN)
 109 +                                exit_error(PARAMETER_PROBLEM,
 110 +                                       "Protocol name in %s too long!", filename);
 111 +                       strncpy(info->protocol, line, MAX_PROTOCOL_LEN);
 112 +
 113 +                       datatype = pattern;
 114 +               }
 115 +               else if(datatype == pattern)
 116 +               {
 117 +                       if(strlen(line) >= MAX_PATTERN_LEN)
 118 +                                exit_error(PARAMETER_PROBLEM, "Pattern in %s too long!", filename);
 119 +                       strncpy(info->pattern, line, MAX_PATTERN_LEN);
 120 +
 121 +                       datatype = done;
 122 +                       break;
 123 +               }
 124 +               else
 125 +                       exit_error(OTHER_PROBLEM, "Internal error");
 126 +       }
 127 +
 128 +       if(datatype != done)
 129 +               exit_error(OTHER_PROBLEM, "Failed to get all needed data from %s", filename);
 130 +
 131 +       if(line) free(line);
 132 +       fclose(f);
 133 +
 134 +       return 1;
 135 +
 136 +/*
 137 +       fprintf(stderr, "protocol: %s\npattern: %s\n\n",
 138 +                       info->protocol,
 139 +                       info->pattern);
 140 +*/
 141 +}
 142 +
 143 +static int hex2dec(char c)
 144 +{
 145 +        switch (c)
 146 +        {
 147 +                case '0' ... '9':
 148 +                        return c - '0';
 149 +                case 'a' ... 'f':
 150 +                        return c - 'a' + 10;
 151 +                case 'A' ... 'F':
 152 +                        return c - 'A' + 10;
 153 +                default:
 154 +                        exit_error(OTHER_PROBLEM, "hex2dec: bad value!\n");
 155 +                        return 0;
 156 +        }
 157 +}
 158 +
 159 +/* takes a string with \xHH escapes and returns one with the characters
 160 +they stand for */
 161 +static char * pre_process(char * s)
 162 +{
 163 +       char * result = malloc(strlen(s) + 1);
 164 +       int sindex = 0, rindex = 0;
 165 +        while( sindex < strlen(s) )
 166 +        {
 167 +            if( sindex + 3 < strlen(s) &&
 168 +                s[sindex] == '\\' && s[sindex+1] == 'x' &&
 169 +                isxdigit(s[sindex + 2]) && isxdigit(s[sindex + 3]) )
 170 +                {
 171 +                        /* carefully remember to call tolower here... */
 172 +                        result[rindex] = tolower( hex2dec(s[sindex + 2])*16 +
 173 +                                                  hex2dec(s[sindex + 3] ) );
 174 +
 175 +                       switch ( result[rindex] )
 176 +                       {
 177 +                       case 0x24:
 178 +                       case 0x28:
 179 +                       case 0x29:
 180 +                       case 0x2a:
 181 +                       case 0x2b:
 182 +                       case 0x2e:
 183 +                       case 0x3f:
 184 +                       case 0x5b:
 185 +                       case 0x5c:
 186 +                       case 0x5d:
 187 +                       case 0x5e:
 188 +                       case 0x7c:
 189 +                               fprintf(stderr,
 190 +                                       "Warning: layer7 regexp contains a control character, %c, in hex (\\x%c%c).\n"
 191 +                                       "I recommend that you write this as %c or \\%c, depending on what you meant.\n",
 192 +                                       result[rindex], s[sindex + 2], s[sindex + 3], result[rindex], result[rindex]);
 193 +                               break;
 194 +                       case 0x00:
 195 +                               fprintf(stderr,
 196 +                                       "Warning: null (\\x00) in layer7 regexp.  A null terminates the regexp string!\n");
 197 +                               break;
 198 +                       default:
 199 +                               break;
 200 +                       }
 201 +
 202 +
 203 +                        sindex += 3; /* 4 total */
 204 +                }
 205 +                else
 206 +                        result[rindex] = tolower(s[sindex]);
 207 +
 208 +               sindex++;
 209 +               rindex++;
 210 +        }
 211 +       result[rindex] = '\0';
 212 +
 213 +       return result;
 214 +}
 215 +
 216 +#define MAX_SUBDIRS 128
 217 +char ** readl7dir(char * dirname)
 218 +{
 219 +        DIR             * scratchdir;
 220 +        struct dirent   ** namelist;
 221 +       char ** subdirs = malloc(MAX_SUBDIRS * sizeof(char *));
 222 +
 223 +        int n, d = 1;
 224 +       subdirs[0] = "";
 225 +
 226 +        n = scandir(dirname, &namelist, 0, alphasort);
 227 +
 228 +       if (n < 0)
 229 +       {
 230 +            perror("scandir");
 231 +           exit_error(OTHER_PROBLEM, "Couldn't open %s\n", dirname);
 232 +       }
 233 +        else
 234 +       {
 235 +               while(n--)
 236 +               {
 237 +                       char fulldirname[MAX_FN_LEN];
 238 +
 239 +                       snprintf(fulldirname, MAX_FN_LEN, "%s/%s", dirname, namelist[n]->d_name);
 240 +
 241 +                       if((scratchdir = opendir(fulldirname)) != NULL)
 242 +                       {
 243 +                               closedir(scratchdir);
 244 +
 245 +                               if(!strcmp(namelist[n]->d_name, ".") ||
 246 +                                  !strcmp(namelist[n]->d_name, ".."))
 247 +                                       /* do nothing */ ;
 248 +                               else
 249 +                               {
 250 +                                       subdirs[d] = malloc(strlen(namelist[n]->d_name) + 1);
 251 +                                       strcpy(subdirs[d], namelist[n]->d_name);
 252 +                                       d++;
 253 +                                       if(d >= MAX_SUBDIRS - 1)
 254 +                                       {
 255 +                                               fprintf(stderr,
 256 +                                                 "Too many subdirectories, skipping the rest!\n");
 257 +                                               break;
 258 +                                       }
 259 +                               }
 260 +                       }
 261 +                       free(namelist[n]);
 262 +               }
 263 +               free(namelist);
 264 +        }
 265 +
 266 +       subdirs[d] = NULL;
 267 +
 268 +       return subdirs;
 269 +}
 270 +
 271 +static void
 272 +parse_layer7_protocol(const unsigned char *s, struct ipt_layer7_info *info)
 273 +{
 274 +       char filename[MAX_FN_LEN];
 275 +       char * dir = NULL;
 276 +       char ** subdirs;
 277 +       int n = 0, done = 0;
 278 +
 279 +       if(strlen(l7dir) > 0)
 280 +               dir = l7dir;
 281 +       else
 282 +               dir = "/etc/l7-protocols";
 283 +
 284 +       subdirs = readl7dir(dir);
 285 +
 286 +       while(subdirs[n] != NULL)
 287 +       {
 288 +               int c = snprintf(filename, MAX_FN_LEN, "%s/%s/%s.pat", dir, subdirs[n], s);
 289 +
 290 +               //fprintf(stderr, "Trying to find pattern in %s ... ", filename);
 291 +
 292 +               if(c > MAX_FN_LEN)
 293 +               {
 294 +                       exit_error(OTHER_PROBLEM,
 295 +                               "Filename beginning with %s is too long!\n", filename);
 296 +               }
 297 +
 298 +               /* read in the pattern from the file */
 299 +               if(parse_protocol_file(filename, s, info))
 300 +               {
 301 +                       //fprintf(stderr, "found\n");
 302 +                       done = 1;
 303 +                       break;
 304 +               }
 305 +
 306 +               //fprintf(stderr, "not found\n");
 307 +
 308 +               n++;
 309 +       }
 310 +
 311 +       if(!done)
 312 +               exit_error(OTHER_PROBLEM,
 313 +                       "Couldn't find a pattern definition file for %s.\n", s);
 314 +
 315 +       /* process \xHH escapes and tolower everything. (our regex lib has no
 316 +       case insensitivity option.) */
 317 +       strncpy(info->pattern, pre_process(info->pattern), MAX_PATTERN_LEN);
 318 +}
 319 +
 320 +/* Function which parses command options; returns true if it ate an option */
 321 +static int parse(int c, char **argv, int invert, unsigned int *flags,
 322 +      const struct ipt_entry *entry, unsigned int *nfcache,
 323 +      struct ipt_entry_match **match)
 324 +{
 325 +       struct ipt_layer7_info *layer7info =
 326 +               (struct ipt_layer7_info *)(*match)->data;
 327 +
 328 +       switch (c) {
 329 +       case '1':
 330 +               check_inverse(optarg, &invert, &optind, 0);
 331 +               parse_layer7_protocol(argv[optind-1], layer7info);
 332 +               if (invert)
 333 +                       layer7info->invert = 1;
 334 +               *flags = 1;
 335 +               break;
 336 +
 337 +       case '2':
 338 +               /* not going to use this, but maybe we need to strip a ! anyway (?) */
 339 +               check_inverse(optarg, &invert, &optind, 0);
 340 +
 341 +               if(strlen(argv[optind-1]) >= MAX_FN_LEN)
 342 +                       exit_error(PARAMETER_PROBLEM, "directory name too long\n");
 343 +
 344 +               strncpy(l7dir, argv[optind-1], MAX_FN_LEN);
 345 +
 346 +               *flags = 1;
 347 +               break;
 348 +
 349 +       default:
 350 +               return 0;
 351 +       }
 352 +
 353 +       return 1;
 354 +}
 355 +
 356 +/* Final check; must have specified --l7proto */
 357 +static void final_check(unsigned int flags)
 358 +{
 359 +       if (!flags)
 360 +               exit_error(PARAMETER_PROBLEM,
 361 +                          "LAYER7 match: You must specify `--l7proto'");
 362 +}
 363 +
 364 +static void print_protocol(char s[], int invert, int numeric)
 365 +{
 366 +       fputs("l7proto ", stdout);
 367 +       if (invert) fputc('!', stdout);
 368 +       printf("%s ", s);
 369 +}
 370 +
 371 +/* Prints out the matchinfo. */
 372 +static void print(const struct ipt_ip *ip,
 373 +      const struct ipt_entry_match *match,
 374 +      int numeric)
 375 +{
 376 +       printf("LAYER7 ");
 377 +
 378 +       print_protocol(((struct ipt_layer7_info *)match->data)->protocol,
 379 +                 ((struct ipt_layer7_info *)match->data)->invert, numeric);
 380 +}
 381 +/* Saves the union ipt_matchinfo in parsable form to stdout. */
 382 +static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
 383 +{
 384 +        const struct ipt_layer7_info *info =
 385 +            (const struct ipt_layer7_info*) match->data;
 386 +
 387 +        printf("--l7proto %s%s ", (info->invert)   ? "! ": "", info->protocol);
 388 +}
 389 +
 390 +static struct iptables_match layer7 = {
 391 +    .name          = "layer7",
 392 +    .version       = IPTABLES_VERSION,
 393 +    .size          = IPT_ALIGN(sizeof(struct ipt_layer7_info)),
 394 +    .userspacesize = IPT_ALIGN(sizeof(struct ipt_layer7_info)),
 395 +    .help          = &help,
 396 +    .parse         = &parse,
 397 +    .final_check   = &final_check,
 398 +    .print         = &print,
 399 +    .save          = &save,
 400 +    .extra_opts    = opts
 401 +};
 402 +
 403 +void _init(void)
 404 +{
 405 +       register_match(&layer7);
 406 +}
 407 Index: iptables-1.3.8/extensions/libipt_layer7.man
 408 ===================================================================
 409 --- /dev/null
 410 +++ iptables-1.3.8/extensions/libipt_layer7.man
 411 @@ -0,0 +1,14 @@
 412 +This module matches packets based on the application layer data of
 413 +their connections.  It uses regular expression matching to compare
 414 +the application layer data to regular expressions found it the layer7
 415 +configuration files.  This is an experimental module which can be found at
 416 +http://l7-filter.sf.net.  It takes two options.
 417 +.TP
 418 +.BI "--l7proto " "\fIprotocol\fP"
 419 +Match the specified protocol.  The protocol name must match a file
 420 +name in /etc/l7-protocols/ or one of its first-level child directories.
 421 +.TP
 422 +.BI "--l7dir " "\fIdirectory\fP"
 423 +Use \fIdirectory\fP instead of /etc/l7-protocols/.  This option must be
 424 +specified before --l7proto.
 425 +