src/ipp2p/ipt_ipp2p.c

   1 #if defined(MODVERSIONS)
   2 #include <linux/modversions.h>
   3 #endif
   4 #include <linux/module.h>
   5 #include <linux/netfilter_ipv4/ip_tables.h>
   6 #include <linux/version.h>
   7 //#include <linux/netfilter_ipv4/ipt_ipp2p.h>
   8 #include "ipt_ipp2p.h"
   9 #include <net/tcp.h>
  10 #include <net/udp.h>
  11
  12 #define get_u8(X,O)  (*(__u8 *)(X + O))
  13 #define get_u16(X,O)  (*(__u16 *)(X + O))
  14 #define get_u32(X,O)  (*(__u32 *)(X + O))
  15
  16 MODULE_AUTHOR("Eicke Friedrich/Klaus Degner <ipp2p@ipp2p.org>");
  17 MODULE_DESCRIPTION("An extension to iptables to identify P2P traffic.");
  18 MODULE_LICENSE("GPL");
  19
  20
  21 /*Search for UDP eDonkey/eMule/Kad commands*/
  22 int
  23 udp_search_edk (unsigned char *haystack, int packet_len)
  24 {
  25     unsigned char *t = haystack;
  26     t += 8;
  27
  28         switch (t[0]) {
  29                 case 0xe3:
  30                 {       /*edonkey*/
  31                         switch (t[1])
  32                         {
  33                                 /* client -> server status request */
  34                                 case 0x96:
  35                                         if (packet_len == 14) return ((IPP2P_EDK * 100) + 50);
  36                                         break;
  37                                 /* server -> client status request */
  38                                 case 0x97: if (packet_len == 42) return ((IPP2P_EDK * 100) + 51);
  39                                         break;
  40                                                 /* server description request */
  41                                                 /* e3 2a ff f0 .. | size == 6 */
  42                                 case 0xa2: if ( (packet_len == 14) && ( get_u16(t,2) == __constant_htons(0xfff0) ) ) return ((IPP2P_EDK * 100) + 52);
  43                                         break;
  44                                                 /* server description response */
  45                                                 /* e3 a3 ff f0 ..  | size > 40 && size < 200 */
  46                                 //case 0xa3: return ((IPP2P_EDK * 100) + 53);
  47                                 //      break;
  48                                 case 0x9a: if (packet_len==26) return ((IPP2P_EDK * 100) + 54);
  49                                         break;
  50
  51                                 case 0x92: if (packet_len==18) return ((IPP2P_EDK * 100) + 55);
  52                                         break;
  53                         }
  54                         break;
  55                 }
  56                 case 0xe4:
  57                 {
  58                         switch (t[1])
  59                         {
  60                                                 /* e4 20 .. | size == 43 */
  61                                 case 0x20: if ((packet_len == 43) && (t[2] != 0x00) && (t[34] != 0x00)) return ((IPP2P_EDK * 100) + 60);
  62                                         break;
  63                                                 /* e4 00 .. 00 | size == 35 ? */
  64                                 case 0x00: if ((packet_len == 35) && (t[26] == 0x00)) return ((IPP2P_EDK * 100) + 61);
  65                                         break;
  66                                                 /* e4 10 .. 00 | size == 35 ? */
  67                                 case 0x10: if ((packet_len == 35) && (t[26] == 0x00)) return ((IPP2P_EDK * 100) + 62);
  68                                         break;
  69                                                 /* e4 18 .. 00 | size == 35 ? */
  70                                 case 0x18: if ((packet_len == 35) && (t[26] == 0x00)) return ((IPP2P_EDK * 100) + 63);
  71                                         break;
  72                                                 /* e4 52 .. | size = 44 */
  73                                 case 0x52: if (packet_len == 44 ) return ((IPP2P_EDK * 100) + 64);
  74                                         break;
  75                                                 /* e4 58 .. | size == 6 */
  76                                 case 0x58: if (packet_len == 14 ) return ((IPP2P_EDK * 100) + 65);
  77                                         break;
  78                                                 /* e4 59 .. | size == 2 */
  79                                 case 0x59: if (packet_len == 10 )return ((IPP2P_EDK * 100) + 66);
  80                                         break;
  81                                         /* e4 28 .. | packet_len == 52,77,102,127... */
  82                                 case 0x28: if (((packet_len-52) % 25) == 0) return ((IPP2P_EDK * 100) + 67);
  83                                         break;
  84                                         /* e4 50 xx xx | size == 4 */
  85                                 case 0x50: if (packet_len == 12) return ((IPP2P_EDK * 100) + 68);
  86                                         break;
  87                                         /* e4 40 xx xx | size == 48 */
  88                                 case 0x40: if (packet_len == 56) return ((IPP2P_EDK * 100) + 69);
  89                                         break;
  90                         }
  91                         break;
  92                 }
  93         } /* end of switch (t[0]) */
  94     return 0;
  95 }/*udp_search_edk*/
  96
  97
  98 /*Search for UDP Gnutella commands*/
  99 int
 100 udp_search_gnu (unsigned char *haystack, int packet_len)
 101 {
 102     unsigned char *t = haystack;
 103     t += 8;
 104
 105     if (memcmp(t, "GND", 3) == 0) return ((IPP2P_GNU * 100) + 51);
 106     if (memcmp(t, "GNUTELLA ", 9) == 0) return ((IPP2P_GNU * 100) + 52);
 107     return 0;
 108 }/*udp_search_gnu*/
 109
 110
 111 /*Search for UDP KaZaA commands*/
 112 int
 113 udp_search_kazaa (unsigned char *haystack, int packet_len)
 114 {
 115     unsigned char *t = haystack;
 116
 117     if (t[packet_len-1] == 0x00){
 118         t += (packet_len - 6);
 119         if (memcmp(t, "KaZaA", 5) == 0) return (IPP2P_KAZAA * 100 +50);
 120     }
 121
 122     return 0;
 123 }/*udp_search_kazaa*/
 124
 125 /*Search for UDP DirectConnect commands*/
 126 int
 127 udp_search_directconnect (unsigned char *haystack, int packet_len)
 128 {
 129     unsigned char *t = haystack;
 130     if ((*(t + 8) == 0x24) && (*(t + packet_len - 1) == 0x7c)) {
 131         t+=8;
 132         if (memcmp(t, "SR ", 3) == 0)                   return ((IPP2P_DC * 100) + 60);
 133         if (memcmp(t, "Ping ", 5) == 0)                 return ((IPP2P_DC * 100) + 61);
 134     }
 135     return 0;
 136 }/*udp_search_directconnect*/
 137
 138
 139
 140 /*Search for UDP BitTorrent commands*/
 141 int
 142 udp_search_bit (unsigned char *haystack, int packet_len)
 143 {
 144         switch(packet_len)
 145         {
 146                 case 24:
 147                         /* ^ 00 00 04 17 27 10 19 80 */
 148                         if ((ntohl(get_u32(haystack, 8)) == 0x00000417) && (ntohl(get_u32(haystack, 12)) == 0x27101980))
 149                                 return (IPP2P_BIT * 100 + 50);
 150                         break;
 151                 case 44:
 152                         if (get_u32(haystack, 16) == __constant_htonl(0x00000400) && get_u32(haystack, 36) == __constant_htonl(0x00000104))
 153                                 return (IPP2P_BIT * 100 + 51);
 154                         if (get_u32(haystack, 16) == __constant_htonl(0x00000400))
 155                                 return (IPP2P_BIT * 100 + 61);
 156                         break;
 157                 case 65:
 158                         if (get_u32(haystack, 16) == __constant_htonl(0x00000404) && get_u32(haystack, 36) == __constant_htonl(0x00000104))
 159                                 return (IPP2P_BIT * 100 + 52);
 160                         if (get_u32(haystack, 16) == __constant_htonl(0x00000404))
 161                                 return (IPP2P_BIT * 100 + 62);
 162                         break;
 163                 case 67:
 164                         if (get_u32(haystack, 16) == __constant_htonl(0x00000406) && get_u32(haystack, 36) == __constant_htonl(0x00000104))
 165                                 return (IPP2P_BIT * 100 + 53);
 166                         if (get_u32(haystack, 16) == __constant_htonl(0x00000406))
 167                                 return (IPP2P_BIT * 100 + 63);
 168                         break;
 169                 case 211:
 170                         if (get_u32(haystack, 8) == __constant_htonl(0x00000405))
 171                                 return (IPP2P_BIT * 100 + 54);
 172                         break;
 173                 case 29:
 174                         if ((get_u32(haystack, 8) == __constant_htonl(0x00000401)))
 175                                 return (IPP2P_BIT * 100 + 55);
 176                         break;
 177                 case 52:
 178                         if (get_u32(haystack,8)  == __constant_htonl(0x00000827) &&
 179                         get_u32(haystack,12) == __constant_htonl(0x37502950))
 180                                 return (IPP2P_BIT * 100 + 80);
 181                         break;
 182                 default:
 183                         /* this packet does not have a constant size */
 184                         if (packet_len >= 40 && get_u32(haystack, 16) == __constant_htonl(0x00000402) && get_u32(haystack, 36) == __constant_htonl(0x00000104))
 185                                 return (IPP2P_BIT * 100 + 56);
 186                         break;
 187         }
 188
 189         /* some extra-bitcomet rules:
 190         * "d1:" [a|r] "d2:id20:"
 191         */
 192         if (packet_len > 30 && get_u8(haystack, 8) == 'd' && get_u8(haystack, 9) == '1' && get_u8(haystack, 10) == ':' )
 193         {
 194                 if (get_u8(haystack, 11) == 'a' || get_u8(haystack, 11) == 'r')
 195                 {
 196                         if (memcmp(haystack+12,"d2:id20:",8)==0)
 197                                 return (IPP2P_BIT * 100 + 57);
 198                 }
 199         }
 200
 201 #if 0
 202         /* bitlord rules */
 203         /* packetlen must be bigger than 40 */
 204         /* first 4 bytes are zero */
 205         if (packet_len > 40 && get_u32(haystack, 8) == 0x00000000)
 206         {
 207                 /* first rule: 00 00 00 00 01 00 00 xx xx xx xx 00 00 00 00*/
 208                 if (get_u32(haystack, 12) == 0x00000000 &&
 209                     get_u32(haystack, 16) == 0x00010000 &&
 210                     get_u32(haystack, 24) == 0x00000000 )
 211                         return (IPP2P_BIT * 100 + 71);
 212
 213                 /* 00 01 00 00 0d 00 00 xx xx xx xx 00 00 00 00*/
 214                 if (get_u32(haystack, 12) == 0x00000001 &&
 215                     get_u32(haystack, 16) == 0x000d0000 &&
 216                     get_u32(haystack, 24) == 0x00000000 )
 217                         return (IPP2P_BIT * 100 + 71);
 218
 219
 220         }
 221 #endif
 222
 223     return 0;
 224 }/*udp_search_bit*/
 225
 226
 227
 228 /*Search for Ares commands*/
 229 //#define IPP2P_DEBUG_ARES
 230 int
 231 search_ares (const unsigned char *payload, const u16 plen)
 232 //int search_ares (unsigned char *haystack, int packet_len, int head_len)
 233 {
 234 //      const unsigned char *t = haystack + head_len;
 235
 236         /* all ares packets start with  */
 237         if (payload[1] == 0 && (plen - payload[0]) == 3)
 238         {
 239                 switch (payload[2])
 240                 {
 241                         case 0x5a:
 242                                 /* ares connect */
 243                                 if ( plen == 6 && payload[5] == 0x05 ) return ((IPP2P_ARES * 100) + 1);
 244                                 break;
 245                         case 0x09:
 246                                 /* ares search, min 3 chars --> 14 bytes
 247                                  * lets define a search can be up to 30 chars --> max 34 bytes
 248                                  */
 249                                 if ( plen >= 14 && plen <= 34 ) return ((IPP2P_ARES * 100) + 1);
 250                                 break;
 251 #ifdef IPP2P_DEBUG_ARES
 252                         default:
 253                         printk(KERN_DEBUG "Unknown Ares command %x recognized, len: %u \n", (unsigned int) payload[2],plen);
 254 #endif /* IPP2P_DEBUG_ARES */
 255                 }
 256         }
 257
 258 #if 0
 259         /* found connect packet: 03 00 5a 04 03 05 */
 260         /* new version ares 1.8: 03 00 5a xx xx 05 */
 261     if ((plen) == 6){   /* possible connect command*/
 262         if ((payload[0] == 0x03) && (payload[1] == 0x00) && (payload[2] == 0x5a) && (payload[5] == 0x05))
 263             return ((IPP2P_ARES * 100) + 1);
 264     }
 265     if ((plen) == 60){  /* possible download command*/
 266         if ((payload[59] == 0x0a) && (payload[58] == 0x0a)){
 267             if (memcmp(t, "PUSH SHA1:", 10) == 0) /* found download command */
 268                 return ((IPP2P_ARES * 100) + 2);
 269         }
 270     }
 271 #endif
 272
 273     return 0;
 274 } /*search_ares*/
 275
 276 /*Search for SoulSeek commands*/
 277 int
 278 search_soul (const unsigned char *payload, const u16 plen)
 279 {
 280 //#define IPP2P_DEBUG_SOUL
 281     /* match: xx xx xx xx | xx = sizeof(payload) - 4 */
 282     if (get_u32(payload, 0) == (plen - 4)){
 283         const __u32 m=get_u32(payload, 4);
 284         /* match 00 yy yy 00, yy can be everything */
 285         if ( get_u8(payload, 4) == 0x00 && get_u8(payload, 7) == 0x00 )
 286         {
 287 #ifdef IPP2P_DEBUG_SOUL
 288         printk(KERN_DEBUG "0: Soulseek command 0x%x recognized\n",get_u32(payload, 4));
 289 #endif /* IPP2P_DEBUG_SOUL */
 290                 return ((IPP2P_SOUL * 100) + 1);
 291         }
 292
 293         /* next match: 01 yy 00 00 | yy can be everything */
 294         if ( get_u8(payload, 4) == 0x01 && get_u16(payload, 6) == 0x0000 )
 295         {
 296 #ifdef IPP2P_DEBUG_SOUL
 297         printk(KERN_DEBUG "1: Soulseek command 0x%x recognized\n",get_u16(payload, 4));
 298 #endif /* IPP2P_DEBUG_SOUL */
 299                 return ((IPP2P_SOUL * 100) + 2);
 300         }
 301
 302         /* other soulseek commandos are: 1-5,7,9,13-18,22,23,26,28,35-37,40-46,50,51,60,62-69,91,92,1001 */
 303         /* try to do this in an intelligent way */
 304         /* get all small commandos */
 305         switch(m)
 306         {
 307                 case 7:
 308                 case 9:
 309                 case 22:
 310                 case 23:
 311                 case 26:
 312                 case 28:
 313                 case 50:
 314                 case 51:
 315                 case 60:
 316                 case 91:
 317                 case 92:
 318                 case 1001:
 319 #ifdef IPP2P_DEBUG_SOUL
 320                 printk(KERN_DEBUG "2: Soulseek command 0x%x recognized\n",get_u16(payload, 4));
 321 #endif /* IPP2P_DEBUG_SOUL */
 322                 return ((IPP2P_SOUL * 100) + 3);
 323         }
 324
 325         if (m > 0 && m < 6 )
 326         {
 327 #ifdef IPP2P_DEBUG_SOUL
 328                 printk(KERN_DEBUG "3: Soulseek command 0x%x recognized\n",get_u16(payload, 4));
 329 #endif /* IPP2P_DEBUG_SOUL */
 330                 return ((IPP2P_SOUL * 100) + 4);
 331         }
 332         if (m > 12 && m < 19 )
 333         {
 334 #ifdef IPP2P_DEBUG_SOUL
 335                 printk(KERN_DEBUG "4: Soulseek command 0x%x recognized\n",get_u16(payload, 4));
 336 #endif /* IPP2P_DEBUG_SOUL */
 337                 return ((IPP2P_SOUL * 100) + 5);
 338         }
 339
 340         if (m > 34 && m < 38 )
 341         {
 342 #ifdef IPP2P_DEBUG_SOUL
 343                 printk(KERN_DEBUG "5: Soulseek command 0x%x recognized\n",get_u16(payload, 4));
 344 #endif /* IPP2P_DEBUG_SOUL */
 345                 return ((IPP2P_SOUL * 100) + 6);
 346         }
 347
 348         if (m > 39 && m < 47 )
 349         {
 350 #ifdef IPP2P_DEBUG_SOUL
 351                 printk(KERN_DEBUG "6: Soulseek command 0x%x recognized\n",get_u16(payload, 4));
 352 #endif /* IPP2P_DEBUG_SOUL */
 353                 return ((IPP2P_SOUL * 100) + 7);
 354         }
 355
 356         if (m > 61 && m < 70 )
 357         {
 358 #ifdef IPP2P_DEBUG_SOUL
 359                 printk(KERN_DEBUG "7: Soulseek command 0x%x recognized\n",get_u16(payload, 4));
 360 #endif /* IPP2P_DEBUG_SOUL */
 361                 return ((IPP2P_SOUL * 100) + 8);
 362         }
 363
 364 #ifdef IPP2P_DEBUG_SOUL
 365         printk(KERN_DEBUG "unknown SOULSEEK command: 0x%x, first 16 bit: 0x%x, first 8 bit: 0x%x ,soulseek ???\n",get_u32(payload, 4),get_u16(payload, 4) >> 16,get_u8(payload, 4) >> 24);
 366 #endif /* IPP2P_DEBUG_SOUL */
 367     }
 368
 369         /* match 14 00 00 00 01 yy 00 00 00 STRING(YY) 01 00 00 00 00 46|50 00 00 00 00 */
 370         /* without size at the beginning !!! */
 371         if ( get_u32(payload, 0) == 0x14 && get_u8(payload, 4) == 0x01 )
 372         {
 373                 __u32 y=get_u32(payload, 5);
 374                 /* we need 19 chars + string */
 375                 if ( (y + 19) <= (plen) )
 376                 {
 377                         const unsigned char *w=payload+9+y;
 378                         if (get_u32(w, 0) == 0x01 && ( get_u16(w, 4) == 0x4600 || get_u16(w, 4) == 0x5000) && get_u32(w, 6) == 0x00);
 379 #ifdef IPP2P_DEBUG_SOUL
 380                         printk(KERN_DEBUG "Soulssek special client command recognized\n");
 381 #endif /* IPP2P_DEBUG_SOUL */
 382                         return ((IPP2P_SOUL * 100) + 9);
 383                 }
 384         }
 385     return 0;
 386 }
 387
 388
 389 /*Search for WinMX commands*/
 390 int
 391 search_winmx (const unsigned char *payload, const u16 plen)
 392 {
 393 //#define IPP2P_DEBUG_WINMX
 394     if (((plen) == 4) && (memcmp(payload, "SEND", 4) == 0))  return ((IPP2P_WINMX * 100) + 1);
 395     if (((plen) == 3) && (memcmp(payload, "GET", 3) == 0))  return ((IPP2P_WINMX * 100) + 2);
 396     //if (packet_len < (head_len + 10)) return 0;
 397     if (plen < 10) return 0;
 398
 399     if ((memcmp(payload, "SEND", 4) == 0) || (memcmp(payload, "GET", 3) == 0)){
 400         u16 c=4;
 401         const u16 end=plen-2;
 402         u8 count=0;
 403         while (c < end)
 404         {
 405                 if (payload[c]== 0x20 && payload[c+1] == 0x22)
 406                 {
 407                         c++;
 408                         count++;
 409                         if (count>=2) return ((IPP2P_WINMX * 100) + 3);
 410                 }
 411                 c++;
 412         }
 413     }
 414
 415     if ( plen == 149 && payload[0] == '8' )
 416     {
 417 #ifdef IPP2P_DEBUG_WINMX
 418         printk(KERN_INFO "maybe WinMX\n");
 419 #endif
 420         if (get_u32(payload,17) == 0 && get_u32(payload,21) == 0 && get_u32(payload,25) == 0 &&
 421 //          get_u32(payload,33) == __constant_htonl(0x71182b1a) && get_u32(payload,37) == __constant_htonl(0x05050000) &&
 422 //          get_u32(payload,133) == __constant_htonl(0x31097edf) && get_u32(payload,145) == __constant_htonl(0xdcb8f792))
 423             get_u16(payload,39) == 0 && get_u16(payload,135) == __constant_htons(0x7edf) && get_u16(payload,147) == __constant_htons(0xf792))
 424
 425         {
 426 #ifdef IPP2P_DEBUG_WINMX
 427                 printk(KERN_INFO "got WinMX\n");
 428 #endif
 429                 return ((IPP2P_WINMX * 100) + 4);
 430         }
 431     }
 432     return 0;
 433 } /*search_winmx*/
 434
 435
 436 /*Search for appleJuice commands*/
 437 int
 438 search_apple (const unsigned char *payload, const u16 plen)
 439 {
 440     if ( (plen > 7) && (payload[6] == 0x0d) && (payload[7] == 0x0a) && (memcmp(payload, "ajprot", 6) == 0))  return (IPP2P_APPLE * 100);
 441
 442     return 0;
 443 }
 444
 445
 446 /*Search for BitTorrent commands*/
 447 int
 448 search_bittorrent (const unsigned char *payload, const u16 plen)
 449 {
 450     if (plen > 20)
 451     {
 452         /* test for match 0x13+"BitTorrent protocol" */
 453         if (payload[0] == 0x13)
 454         {
 455                 if (memcmp(payload+1, "BitTorrent protocol", 19) == 0) return (IPP2P_BIT * 100);
 456         }
 457
 458         /* get tracker commandos, all starts with GET /
 459         * then it can follow: scrape| announce
 460         * and then ?hash_info=
 461         */
 462         if (memcmp(payload,"GET /",5) == 0)
 463         {
 464                 /* message scrape */
 465                 if ( memcmp(payload+5,"scrape?info_hash=",17)==0 ) return (IPP2P_BIT * 100 + 1);
 466                 /* message announce */
 467                 if ( memcmp(payload+5,"announce?info_hash=",19)==0 ) return (IPP2P_BIT * 100 + 2);
 468         }
 469     }
 470     else
 471     {
 472         /* bitcomet encryptes the first packet, so we have to detect another
 473          * one later in the flow */
 474          /* first try failed, too many missdetections */
 475         //if ( size == 5 && get_u32(t,0) == __constant_htonl(1) && t[4] < 3) return (IPP2P_BIT * 100 + 3);
 476
 477         /* second try: block request packets */
 478         if ( plen == 17 && get_u32(payload,0) == __constant_htonl(0x0d) && payload[4] == 0x06 && get_u32(payload,13) == __constant_htonl(0x4000) ) return (IPP2P_BIT * 100 + 3);
 479     }
 480
 481     return 0;
 482 }
 483
 484
 485
 486 /*check for Kazaa get command*/
 487 int
 488 search_kazaa (const unsigned char *payload, const u16 plen)
 489
 490 {
 491     if ((payload[plen-2] == 0x0d) && (payload[plen-1] == 0x0a) && memcmp(payload, "GET /.hash=", 11) == 0)
 492         return (IPP2P_DATA_KAZAA * 100);
 493
 494     return 0;
 495 }
 496
 497
 498 /*check for gnutella get command*/
 499 int
 500 search_gnu (const unsigned char *payload, const u16 plen)
 501 {
 502     if ((payload[plen-2] == 0x0d) && (payload[plen-1] == 0x0a))
 503     {
 504         if (memcmp(payload, "GET /get/", 9) == 0)       return ((IPP2P_DATA_GNU * 100) + 1);
 505         if (memcmp(payload, "GET /uri-res/", 13) == 0) return ((IPP2P_DATA_GNU * 100) + 2);
 506     }
 507     return 0;
 508 }
 509
 510
 511 /*check for gnutella get commands and other typical data*/
 512 int
 513 search_all_gnu (const unsigned char *payload, const u16 plen)
 514 {
 515
 516     if ((payload[plen-2] == 0x0d) && (payload[plen-1] == 0x0a))
 517     {
 518
 519         if (memcmp(payload, "GNUTELLA CONNECT/", 17) == 0) return ((IPP2P_GNU * 100) + 1);
 520         if (memcmp(payload, "GNUTELLA/", 9) == 0) return ((IPP2P_GNU * 100) + 2);
 521
 522
 523         if ((memcmp(payload, "GET /get/", 9) == 0) || (memcmp(payload, "GET /uri-res/", 13) == 0))
 524         {
 525                 u16 c=8;
 526                 const u16 end=plen-22;
 527                 while (c < end) {
 528                         if ( payload[c] == 0x0a && payload[c+1] == 0x0d && ((memcmp(&payload[c+2], "X-Gnutella-", 11) == 0) || (memcmp(&payload[c+2], "X-Queue:", 8) == 0)))
 529                                 return ((IPP2P_GNU * 100) + 3);
 530                         c++;
 531                 }
 532         }
 533     }
 534     return 0;
 535 }
 536
 537
 538 /*check for KaZaA download commands and other typical data*/
 539 int
 540 search_all_kazaa (const unsigned char *payload, const u16 plen)
 541 {
 542     if ((payload[plen-2] == 0x0d) && (payload[plen-1] == 0x0a))
 543     {
 544
 545         if (memcmp(payload, "GIVE ", 5) == 0) return ((IPP2P_KAZAA * 100) + 1);
 546
 547         if (memcmp(payload, "GET /", 5) == 0) {
 548                 u16 c = 8;
 549                 const u16 end=plen-22;
 550                 while (c < end) {
 551                         if ( payload[c] == 0x0a && payload[c+1] == 0x0d && ((memcmp(&payload[c+2], "X-Kazaa-Username: ", 18) == 0) || (memcmp(&payload[c+2], "User-Agent: PeerEnabler/", 24) == 0)))
 552                                 return ((IPP2P_KAZAA * 100) + 2);
 553                         c++;
 554                 }
 555         }
 556     }
 557     return 0;
 558 }
 559
 560 /*fast check for edonkey file segment transfer command*/
 561 int
 562 search_edk (const unsigned char *payload, const u16 plen)
 563 {
 564     if (payload[0] != 0xe3)
 565         return 0;
 566     else {
 567         if (payload[5] == 0x47)
 568             return (IPP2P_DATA_EDK * 100);
 569         else
 570             return 0;
 571     }
 572 }
 573
 574
 575
 576 /*intensive but slower search for some edonkey packets including size-check*/
 577 int
 578 search_all_edk (const unsigned char *payload, const u16 plen)
 579 {
 580     if (payload[0] != 0xe3)
 581         return 0;
 582     else {
 583         //t += head_len;
 584         const u16 cmd = get_u16(payload, 1);
 585         if (cmd == (plen - 5)) {
 586             switch (payload[5]) {
 587                 case 0x01: return ((IPP2P_EDK * 100) + 1);      /*Client: hello or Server:hello*/
 588                 case 0x4c: return ((IPP2P_EDK * 100) + 9);      /*Client: Hello-Answer*/
 589             }
 590         }
 591         return 0;
 592      }
 593 }
 594
 595
 596 /*fast check for Direct Connect send command*/
 597 int
 598 search_dc (const unsigned char *payload, const u16 plen)
 599 {
 600
 601     if (payload[0] != 0x24 )
 602         return 0;
 603     else {
 604         if (memcmp(&payload[1], "Send|", 5) == 0)
 605             return (IPP2P_DATA_DC * 100);
 606         else
 607             return 0;
 608     }
 609
 610 }
 611
 612
 613 /*intensive but slower check for all direct connect packets*/
 614 int
 615 search_all_dc (const unsigned char *payload, const u16 plen)
 616 {
 617 //    unsigned char *t = haystack;
 618
 619     if (payload[0] == 0x24 && payload[plen-1] == 0x7c)
 620     {
 621         const unsigned char *t=&payload[1];
 622                 /* Client-Hub-Protocol */
 623         if (memcmp(t, "Lock ", 5) == 0)                 return ((IPP2P_DC * 100) + 1);
 624         /* Client-Client-Protocol, some are already recognized by client-hub (like lock) */
 625         if (memcmp(t, "MyNick ", 7) == 0)               return ((IPP2P_DC * 100) + 38);
 626     }
 627     return 0;
 628 }
 629
 630 /*check for mute*/
 631 int
 632 search_mute (const unsigned char *payload, const u16 plen)
 633 {
 634         if ( plen == 209 || plen == 345 || plen == 473 || plen == 609 || plen == 1121 )
 635         {
 636                 //printk(KERN_DEBUG "size hit: %u",size);
 637                 if (memcmp(payload,"PublicKey: ",11) == 0 )
 638                 {
 639                         return ((IPP2P_MUTE * 100) + 0);
 640
 641 /*                      if (memcmp(t+size-14,"\x0aEndPublicKey\x0a",14) == 0)
 642                         {
 643                                 printk(KERN_DEBUG "end pubic key hit: %u",size);
 644
 645                         }*/
 646                 }
 647         }
 648         return 0;
 649 }
 650
 651
 652 /* check for xdcc */
 653 int
 654 search_xdcc (const unsigned char *payload, const u16 plen)
 655 {
 656         /* search in small packets only */
 657         if (plen > 20 && plen < 200 && payload[plen-1] == 0x0a && payload[plen-2] == 0x0d && memcmp(payload,"PRIVMSG ",8) == 0)
 658         {
 659
 660                 u16 x=10;
 661                 const u16 end=plen - 13;
 662
 663                 /* is seems to be a irc private massage, chedck for xdcc command */
 664                 while (x < end)
 665                 {
 666                         if (payload[x] == ':')
 667                         {
 668                                 if ( memcmp(&payload[x+1],"xdcc send #",11) == 0 )
 669                                         return ((IPP2P_XDCC * 100) + 0);
 670                         }
 671                         x++;
 672                 }
 673         }
 674         return 0;
 675 }
 676
 677 /* search for waste */
 678 int search_waste(const unsigned char *payload, const u16 plen)
 679 {
 680         if ( plen >= 8 && memcmp(payload,"GET.sha1:",9) == 0)
 681                 return ((IPP2P_WASTE * 100) + 0);
 682
 683         return 0;
 684 }
 685
 686
 687 static struct {
 688     int command;
 689     __u8 short_hand;                    /*for fucntions included in short hands*/
 690     int packet_len;
 691     int (*function_name) (const unsigned char *, const u16);
 692 } matchlist[] = {
 693     {IPP2P_EDK,SHORT_HAND_IPP2P,20, &search_all_edk},
 694 //    {IPP2P_DATA_KAZAA,SHORT_HAND_DATA,200, &search_kazaa},
 695 //    {IPP2P_DATA_EDK,SHORT_HAND_DATA,60, &search_edk},
 696 //    {IPP2P_DATA_DC,SHORT_HAND_DATA,26, &search_dc},
 697     {IPP2P_DC,SHORT_HAND_IPP2P,5, search_all_dc},
 698 //    {IPP2P_DATA_GNU,SHORT_HAND_DATA,40, &search_gnu},
 699     {IPP2P_GNU,SHORT_HAND_IPP2P,5, &search_all_gnu},
 700     {IPP2P_KAZAA,SHORT_HAND_IPP2P,5, &search_all_kazaa},
 701     {IPP2P_BIT,SHORT_HAND_IPP2P,20, &search_bittorrent},
 702     {IPP2P_APPLE,SHORT_HAND_IPP2P,5, &search_apple},
 703     {IPP2P_SOUL,SHORT_HAND_IPP2P,5, &search_soul},
 704     {IPP2P_WINMX,SHORT_HAND_IPP2P,2, &search_winmx},
 705     {IPP2P_ARES,SHORT_HAND_IPP2P,5, &search_ares},
 706     {IPP2P_MUTE,SHORT_HAND_NONE,200, &search_mute},
 707     {IPP2P_WASTE,SHORT_HAND_NONE,5, &search_waste},
 708     {IPP2P_XDCC,SHORT_HAND_NONE,5, &search_xdcc},
 709     {0,0,0,NULL}
 710 };
 711
 712
 713 static struct {
 714     int command;
 715     __u8 short_hand;                    /*for fucntions included in short hands*/
 716     int packet_len;
 717     int (*function_name) (unsigned char *, int);
 718 } udp_list[] = {
 719     {IPP2P_KAZAA,SHORT_HAND_IPP2P,14, &udp_search_kazaa},
 720     {IPP2P_BIT,SHORT_HAND_IPP2P,23, &udp_search_bit},
 721     {IPP2P_GNU,SHORT_HAND_IPP2P,11, &udp_search_gnu},
 722     {IPP2P_EDK,SHORT_HAND_IPP2P,9, &udp_search_edk},
 723     {IPP2P_DC,SHORT_HAND_IPP2P,12, &udp_search_directconnect},
 724     {0,0,0,NULL}
 725 };
 726
 727
 728 static int
 729 match(const struct sk_buff *skb,
 730       const struct net_device *in,
 731       const struct net_device *out,
 732 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 733       const struct xt_match  *mymatch,
 734       const void *matchinfo,
 735       int offset,
 736       unsigned int myprotoff,
 737 #else
 738       const void *matchinfo,
 739       int offset,
 740 #endif
 741
 742 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 743       const void *hdr,
 744       u_int16_t datalen,
 745 #endif
 746
 747       int *hotdrop)
 748 {
 749     const struct ipt_p2p_info *info = matchinfo;
 750     unsigned char  *haystack;
 751     struct iphdr *ip = skb->nh.iph;
 752     int p2p_result = 0, i = 0;
 753 //    int head_len;
 754     int hlen = ntohs(ip->tot_len)-(ip->ihl*4);  /*hlen = packet-data length*/
 755
 756     /*must not be a fragment*/
 757     if (offset) {
 758         if (info->debug) printk("IPP2P.match: offset found %i \n",offset);
 759         return 0;
 760     }
 761
 762     /*make sure that skb is linear*/
 763     if(skb_is_nonlinear(skb)){
 764         if (info->debug) printk("IPP2P.match: nonlinear skb found\n");
 765         return 0;
 766     }
 767
 768
 769     haystack=(char *)ip+(ip->ihl*4);            /*haystack = packet data*/
 770
 771     switch (ip->protocol){
 772         case IPPROTO_TCP:               /*what to do with a TCP packet*/
 773         {
 774             struct tcphdr *tcph = (void *) ip + ip->ihl * 4;
 775
 776             if (tcph->fin) return 0;  /*if FIN bit is set bail out*/
 777             if (tcph->syn) return 0;  /*if SYN bit is set bail out*/
 778             if (tcph->rst) return 0;  /*if RST bit is set bail out*/
 779
 780             haystack += tcph->doff * 4; /*get TCP-Header-Size*/
 781             hlen -= tcph->doff * 4;
 782             while (matchlist[i].command) {
 783                 if ((((info->cmd & matchlist[i].command) == matchlist[i].command) ||
 784                     ((info->cmd & matchlist[i].short_hand) == matchlist[i].short_hand)) &&
 785                     (hlen > matchlist[i].packet_len)) {
 786                             p2p_result = matchlist[i].function_name(haystack, hlen);
 787                             if (p2p_result)
 788                             {
 789                                 if (info->debug) printk("IPP2P.debug:TCP-match: %i from: %u.%u.%u.%u:%i to: %u.%u.%u.%u:%i Length: %i\n",
 790                                     p2p_result, NIPQUAD(ip->saddr),ntohs(tcph->source), NIPQUAD(ip->daddr),ntohs(tcph->dest),hlen);
 791                                 return p2p_result;
 792                             }
 793                 }
 794             i++;
 795             }
 796             return p2p_result;
 797         }
 798
 799         case IPPROTO_UDP:               /*what to do with an UDP packet*/
 800         {
 801             struct udphdr *udph = (void *) ip + ip->ihl * 4;
 802
 803             while (udp_list[i].command){
 804                 if ((((info->cmd & udp_list[i].command) == udp_list[i].command) ||
 805                     ((info->cmd & udp_list[i].short_hand) == udp_list[i].short_hand)) &&
 806                     (hlen > udp_list[i].packet_len)) {
 807                             p2p_result = udp_list[i].function_name(haystack, hlen);
 808                             if (p2p_result){
 809                                 if (info->debug) printk("IPP2P.debug:UDP-match: %i from: %u.%u.%u.%u:%i to: %u.%u.%u.%u:%i Length: %i\n",
 810                                     p2p_result, NIPQUAD(ip->saddr),ntohs(udph->source), NIPQUAD(ip->daddr),ntohs(udph->dest),hlen);
 811                                 return p2p_result;
 812                             }
 813                 }
 814             i++;
 815             }
 816             return p2p_result;
 817         }
 818
 819         default: return 0;
 820     }
 821 }
 822
 823
 824
 825 static int
 826 checkentry(const char *tablename,
 827 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 828            const void *ip,
 829            const struct xt_match *mymatch,
 830 #else
 831            const struct ipt_ip *ip,
 832 #endif
 833            void *matchinfo,
 834 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)
 835            unsigned int matchsize,
 836 #endif
 837            unsigned int hook_mask)
 838 {
 839         /* Must specify -p tcp */
 840 /*    if (ip->proto != IPPROTO_TCP || (ip->invflags & IPT_INV_PROTO)) {
 841  *      printk("ipp2p: Only works on TCP packets, use -p tcp\n");
 842  *      return 0;
 843  *    }*/
 844     return 1;
 845 }
 846
 847
 848 // TODO: find out what this structure is for (scheme taken
 849 // from kernel sources)
 850 // content seems to have a length of 8 bytes
 851 // (at least on my x86 machine)
 852 struct ipp2p_match_info {
 853         long int dunno_what_this_is_for;
 854         long int i_also_dunno_what_this_is_for;
 855 };
 856
 857 static struct ipt_match ipp2p_match = {
 858 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 859         { NULL, NULL },
 860         "ipp2p",
 861         &match,
 862         &checkentry,
 863         NULL,
 864         THIS_MODULE
 865 #endif
 866 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)) && (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,17))
 867         .name           = "ipp2p",
 868         .match          = &match,
 869         .checkentry     = &checkentry,
 870         .me             = THIS_MODULE,
 871 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 872         .name           = "ipp2p",
 873         .match          = &match,
 874         .family         = AF_INET,
 875         .matchsize      = sizeof(struct ipp2p_match_info),
 876         .checkentry     = &checkentry,
 877         .me             = THIS_MODULE,
 878 #endif
 879 };
 880
 881
 882 static int __init init(void)
 883 {
 884     printk(KERN_INFO "IPP2P v%s loading\n", IPP2P_VERSION);
 885 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21)
 886     return xt_register_match(&ipp2p_match);
 887 #else
 888     return ipt_register_match(&ipp2p_match);
 889 #endif
 890 }
 891
 892 static void __exit fini(void)
 893 {
 894 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21)
 895     xt_unregister_match(&ipp2p_match);
 896 #else
 897     ipt_unregister_match(&ipp2p_match);
 898 #endif
 899     printk(KERN_INFO "IPP2P v%s unloaded\n", IPP2P_VERSION);
 900 }
 901
 902 module_init(init);
 903 module_exit(fini);
 904
 905