target/linux/generic-2.4/patches/615-netfilter_nat_mms.patch

   1 Index: linux-2.4.35.4/net/ipv4/netfilter/Config.in
   2 ===================================================================
   3 --- linux-2.4.35.4.orig/net/ipv4/netfilter/Config.in
   4 +++ linux-2.4.35.4/net/ipv4/netfilter/Config.in
   5 @@ -17,6 +17,7 @@ if [ "$CONFIG_IP_NF_CONNTRACK" != "n" ];
   6    dep_tristate '   PPTP protocol support' CONFIG_IP_NF_PPTP $CONFIG_IP_NF_CT_PROTO_GRE
   7    dep_tristate '  H.323 (netmeeting) support' CONFIG_IP_NF_H323 $CONFIG_IP_NF_CONNTRACK
   8    dep_tristate '  RTSP protocol support' CONFIG_IP_NF_RTSP $CONFIG_IP_NF_CONNTRACK
   9 +  dep_tristate '  MMS protocol support' CONFIG_IP_NF_MMS $CONFIG_IP_NF_CONNTRACK
  10  fi
  11
  12  if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
  13 @@ -126,6 +127,13 @@ if [ "$CONFIG_IP_NF_IPTABLES" != "n" ];
  14           define_tristate CONFIG_IP_NF_NAT_RTSP $CONFIG_IP_NF_NAT
  15         fi
  16        fi
  17 +      if [ "$CONFIG_IP_NF_MMS" = "m" ]; then
  18 +       define_tristate CONFIG_IP_NF_NAT_MMS m
  19 +      else
  20 +       if [ "$CONFIG_IP_NF_MMS" = "y" ]; then
  21 +         define_tristate CONFIG_IP_NF_NAT_MMS $CONFIG_IP_NF_NAT
  22 +       fi
  23 +      fi
  24        if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
  25          dep_tristate '    Basic SNMP-ALG support (EXPERIMENTAL)' CONFIG_IP_NF_NAT_SNMP_BASIC $CONFIG_IP_NF_NAT
  26        fi
  27 Index: linux-2.4.35.4/net/ipv4/netfilter/Makefile
  28 ===================================================================
  29 --- linux-2.4.35.4.orig/net/ipv4/netfilter/Makefile
  30 +++ linux-2.4.35.4/net/ipv4/netfilter/Makefile
  31 @@ -61,6 +61,10 @@ obj-$(CONFIG_IP_NF_RTSP) += ip_conntrack
  32  ifdef CONFIG_IP_NF_NAT_RTSP
  33         export-objs += ip_conntrack_rtsp.o
  34  endif
  35 +obj-$(CONFIG_IP_NF_MMS) += ip_conntrack_mms.o
  36 +ifdef CONFIG_IP_NF_NAT_MMS
  37 +       export-objs += ip_conntrack_mms.o
  38 +endif
  39
  40
  41
  42 @@ -73,6 +77,7 @@ obj-$(CONFIG_IP_NF_NAT_PROTO_GRE) += ip_
  43  obj-$(CONFIG_IP_NF_NAT_PPTP) += ip_nat_pptp.o
  44  obj-$(CONFIG_IP_NF_NAT_H323) += ip_nat_h323.o
  45  obj-$(CONFIG_IP_NF_NAT_RTSP) += ip_nat_rtsp.o
  46 +obj-$(CONFIG_IP_NF_NAT_MMS) += ip_nat_mms.o
  47
  48  # generic IP tables
  49  obj-$(CONFIG_IP_NF_IPTABLES) += ip_tables.o
  50 Index: linux-2.4.35.4/net/ipv4/netfilter/ip_conntrack_mms.c
  51 ===================================================================
  52 --- /dev/null
  53 +++ linux-2.4.35.4/net/ipv4/netfilter/ip_conntrack_mms.c
  54 @@ -0,0 +1,292 @@
  55 +/* MMS extension for IP connection tracking
  56 + * (C) 2002 by Filip Sneppe <filip.sneppe@cronos.be>
  57 + * based on ip_conntrack_ftp.c and ip_conntrack_irc.c
  58 + *
  59 + * ip_conntrack_mms.c v0.3 2002-09-22
  60 + *
  61 + *      This program is free software; you can redistribute it and/or
  62 + *      modify it under the terms of the GNU General Public License
  63 + *      as published by the Free Software Foundation; either version
  64 + *      2 of the License, or (at your option) any later version.
  65 + *
  66 + *      Module load syntax:
  67 + *      insmod ip_conntrack_mms.o ports=port1,port2,...port<MAX_PORTS>
  68 + *
  69 + *      Please give the ports of all MMS servers You wish to connect to.
  70 + *      If you don't specify ports, the default will be TCP port 1755.
  71 + *
  72 + *      More info on MMS protocol, firewalls and NAT:
  73 + *      http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwmt/html/MMSFirewall.asp
  74 + *      http://www.microsoft.com/windows/windowsmedia/serve/firewall.asp
  75 + *
  76 + *      The SDP project people are reverse-engineering MMS:
  77 + *      http://get.to/sdp
  78 + */
  79 +
  80 +#include <linux/config.h>
  81 +#include <linux/module.h>
  82 +#include <linux/netfilter.h>
  83 +#include <linux/ip.h>
  84 +#include <linux/ctype.h>
  85 +#include <net/checksum.h>
  86 +#include <net/tcp.h>
  87 +
  88 +#include <linux/netfilter_ipv4/lockhelp.h>
  89 +#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
  90 +#include <linux/netfilter_ipv4/ip_conntrack_mms.h>
  91 +
  92 +DECLARE_LOCK(ip_mms_lock);
  93 +struct module *ip_conntrack_mms = THIS_MODULE;
  94 +
  95 +#define MAX_PORTS 8
  96 +static int ports[MAX_PORTS];
  97 +static int ports_c;
  98 +#ifdef MODULE_PARM
  99 +MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_PORTS) "i");
 100 +#endif
 101 +
 102 +#define DEBUGP(format, args...)
 103 +
 104 +#ifdef CONFIG_IP_NF_NAT_NEEDED
 105 +EXPORT_SYMBOL(ip_mms_lock);
 106 +#endif
 107 +
 108 +MODULE_AUTHOR("Filip Sneppe <filip.sneppe@cronos.be>");
 109 +MODULE_DESCRIPTION("Microsoft Windows Media Services (MMS) connection tracking module");
 110 +MODULE_LICENSE("GPL");
 111 +
 112 +/* #define isdigit(c) (c >= '0' && c <= '9') */
 113 +
 114 +/* copied from drivers/usb/serial/io_edgeport.c - not perfect but will do the trick */
 115 +static void unicode_to_ascii (char *string, short *unicode, int unicode_size)
 116 +{
 117 +       int i;
 118 +       for (i = 0; i < unicode_size; ++i) {
 119 +               string[i] = (char)(unicode[i]);
 120 +       }
 121 +       string[unicode_size] = 0x00;
 122 +}
 123 +
 124 +__inline static int atoi(char *s)
 125 +{
 126 +       int i=0;
 127 +       while (isdigit(*s)) {
 128 +               i = i*10 + *(s++) - '0';
 129 +       }
 130 +       return i;
 131 +}
 132 +
 133 +/* convert ip address string like "192.168.0.10" to unsigned int */
 134 +__inline static u_int32_t asciiiptoi(char *s)
 135 +{
 136 +       unsigned int i, j, k;
 137 +
 138 +       for(i=k=0; k<3; ++k, ++s, i<<=8) {
 139 +               i+=atoi(s);
 140 +               for(j=0; (*(++s) != '.') && (j<3); ++j)
 141 +                       ;
 142 +       }
 143 +       i+=atoi(s);
 144 +       return ntohl(i);
 145 +}
 146 +
 147 +int parse_mms(const char *data,
 148 +             const unsigned int datalen,
 149 +             u_int32_t *mms_ip,
 150 +             u_int16_t *mms_proto,
 151 +             u_int16_t *mms_port,
 152 +             char **mms_string_b,
 153 +             char **mms_string_e,
 154 +             char **mms_padding_e)
 155 +{
 156 +       int unicode_size, i;
 157 +       char tempstring[28];       /* "\\255.255.255.255\UDP\65535" */
 158 +       char getlengthstring[28];
 159 +
 160 +       for(unicode_size=0;
 161 +           (char) *(data+(MMS_SRV_UNICODE_STRING_OFFSET+unicode_size*2)) != (char)0;
 162 +           unicode_size++)
 163 +               if ((unicode_size == 28) || (MMS_SRV_UNICODE_STRING_OFFSET+unicode_size*2 >= datalen))
 164 +                       return -1; /* out of bounds - incomplete packet */
 165 +
 166 +       unicode_to_ascii(tempstring, (short *)(data+MMS_SRV_UNICODE_STRING_OFFSET), unicode_size);
 167 +       DEBUGP("ip_conntrack_mms: offset 60: %s\n", (const char *)(tempstring));
 168 +
 169 +       /* IP address ? */
 170 +       *mms_ip = asciiiptoi(tempstring+2);
 171 +
 172 +       i=sprintf(getlengthstring, "%u.%u.%u.%u", HIPQUAD(*mms_ip));
 173 +
 174 +       /* protocol ? */
 175 +       if(strncmp(tempstring+3+i, "TCP", 3)==0)
 176 +               *mms_proto = IPPROTO_TCP;
 177 +       else if(strncmp(tempstring+3+i, "UDP", 3)==0)
 178 +               *mms_proto = IPPROTO_UDP;
 179 +
 180 +       /* port ? */
 181 +       *mms_port = atoi(tempstring+7+i);
 182 +
 183 +       /* we store a pointer to the beginning of the "\\a.b.c.d\proto\port"
 184 +          unicode string, one to the end of the string, and one to the end
 185 +          of the packet, since we must keep track of the number of bytes
 186 +          between end of the unicode string and the end of packet (padding) */
 187 +       *mms_string_b  = (char *)(data + MMS_SRV_UNICODE_STRING_OFFSET);
 188 +       *mms_string_e  = (char *)(data + MMS_SRV_UNICODE_STRING_OFFSET + unicode_size * 2);
 189 +       *mms_padding_e = (char *)(data + datalen); /* looks funny, doesn't it */
 190 +       return 0;
 191 +}
 192 +
 193 +
 194 +static int help(const struct iphdr *iph, size_t len,
 195 +               struct ip_conntrack *ct,
 196 +               enum ip_conntrack_info ctinfo)
 197 +{
 198 +       /* tcplen not negative guaranteed by ip_conntrack_tcp.c */
 199 +       struct tcphdr *tcph = (void *)iph + iph->ihl * 4;
 200 +       const char *data = (const char *)tcph + tcph->doff * 4;
 201 +       unsigned int tcplen = len - iph->ihl * 4;
 202 +       unsigned int datalen = tcplen - tcph->doff * 4;
 203 +       int dir = CTINFO2DIR(ctinfo);
 204 +       struct ip_conntrack_expect expect, *exp = &expect;
 205 +       struct ip_ct_mms_expect *exp_mms_info = &exp->help.exp_mms_info;
 206 +
 207 +       u_int32_t mms_ip;
 208 +       u_int16_t mms_proto;
 209 +       char mms_proto_string[8];
 210 +       u_int16_t mms_port;
 211 +       char *mms_string_b, *mms_string_e, *mms_padding_e;
 212 +
 213 +       /* Until there's been traffic both ways, don't look in packets. */
 214 +       if (ctinfo != IP_CT_ESTABLISHED
 215 +           && ctinfo != IP_CT_ESTABLISHED+IP_CT_IS_REPLY) {
 216 +               DEBUGP("ip_conntrack_mms: Conntrackinfo = %u\n", ctinfo);
 217 +               return NF_ACCEPT;
 218 +       }
 219 +
 220 +       /* Not whole TCP header? */
 221 +       if (tcplen < sizeof(struct tcphdr) || tcplen < tcph->doff*4) {
 222 +               DEBUGP("ip_conntrack_mms: tcplen = %u\n", (unsigned)tcplen);
 223 +               return NF_ACCEPT;
 224 +       }
 225 +
 226 +       /* Checksum invalid?  Ignore. */
 227 +       if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
 228 +           csum_partial((char *)tcph, tcplen, 0))) {
 229 +               DEBUGP("mms_help: bad csum: %p %u %u.%u.%u.%u %u.%u.%u.%u\n",
 230 +                      tcph, tcplen, NIPQUAD(iph->saddr),
 231 +                      NIPQUAD(iph->daddr));
 232 +               return NF_ACCEPT;
 233 +       }
 234 +
 235 +       /* Only look at packets with 0x00030002/196610 on bytes 36->39 of TCP payload */
 236 +       if( (MMS_SRV_MSG_OFFSET < datalen) &&
 237 +           ((*(u32 *)(data+MMS_SRV_MSG_OFFSET)) == MMS_SRV_MSG_ID)) {
 238 +               DEBUGP("ip_conntrack_mms: offset 37: %u %u %u %u, datalen:%u\n",
 239 +                      (u8)*(data+36), (u8)*(data+37),
 240 +                      (u8)*(data+38), (u8)*(data+39),
 241 +                      datalen);
 242 +               if(parse_mms(data, datalen, &mms_ip, &mms_proto, &mms_port,
 243 +                            &mms_string_b, &mms_string_e, &mms_padding_e))
 244 +                       if(net_ratelimit())
 245 +                               printk(KERN_WARNING
 246 +                                      "ip_conntrack_mms: Unable to parse data payload\n");
 247 +
 248 +               memset(&expect, 0, sizeof(expect));
 249 +
 250 +               sprintf(mms_proto_string, "(%u)", mms_proto);
 251 +               DEBUGP("ip_conntrack_mms: adding %s expectation %u.%u.%u.%u -> %u.%u.%u.%u:%u\n",
 252 +                      mms_proto == IPPROTO_TCP ? "TCP"
 253 +                      : mms_proto == IPPROTO_UDP ? "UDP":mms_proto_string,
 254 +                      NIPQUAD(ct->tuplehash[!dir].tuple.src.ip),
 255 +                      NIPQUAD(mms_ip),
 256 +                      mms_port);
 257 +
 258 +               /* it's possible that the client will just ask the server to tunnel
 259 +                  the stream over the same TCP session (from port 1755): there's
 260 +                  shouldn't be a need to add an expectation in that case, but it
 261 +                  makes NAT packet mangling so much easier */
 262 +               LOCK_BH(&ip_mms_lock);
 263 +
 264 +               DEBUGP("ip_conntrack_mms: tcph->seq = %u\n", tcph->seq);
 265 +
 266 +               exp->seq = ntohl(tcph->seq) + (mms_string_b - data);
 267 +               exp_mms_info->len     = (mms_string_e  - mms_string_b);
 268 +               exp_mms_info->padding = (mms_padding_e - mms_string_e);
 269 +               exp_mms_info->port    = mms_port;
 270 +
 271 +               DEBUGP("ip_conntrack_mms: wrote info seq=%u (ofs=%u), len=%d, padding=%u\n",
 272 +                      exp->seq, (mms_string_e - data), exp_mms_info->len, exp_mms_info->padding);
 273 +
 274 +               exp->tuple = ((struct ip_conntrack_tuple)
 275 +                             { { ct->tuplehash[!dir].tuple.src.ip, { 0 } },
 276 +                             { mms_ip,
 277 +                               { (__u16) ntohs(mms_port) },
 278 +                               mms_proto } }
 279 +                            );
 280 +               exp->mask  = ((struct ip_conntrack_tuple)
 281 +                            { { 0xFFFFFFFF, { 0 } },
 282 +                              { 0xFFFFFFFF, { 0xFFFF }, 0xFFFF }});
 283 +               exp->expectfn = NULL;
 284 +               ip_conntrack_expect_related(ct, &expect);
 285 +               UNLOCK_BH(&ip_mms_lock);
 286 +       }
 287 +
 288 +       return NF_ACCEPT;
 289 +}
 290 +
 291 +static struct ip_conntrack_helper mms[MAX_PORTS];
 292 +static char mms_names[MAX_PORTS][10];
 293 +
 294 +/* Not __exit: called from init() */
 295 +static void fini(void)
 296 +{
 297 +       int i;
 298 +       for (i = 0; (i < MAX_PORTS) && ports[i]; i++) {
 299 +               DEBUGP("ip_conntrack_mms: unregistering helper for port %d\n",
 300 +                               ports[i]);
 301 +               ip_conntrack_helper_unregister(&mms[i]);
 302 +       }
 303 +}
 304 +
 305 +static int __init init(void)
 306 +{
 307 +       int i, ret;
 308 +       char *tmpname;
 309 +
 310 +       if (ports[0] == 0)
 311 +               ports[0] = MMS_PORT;
 312 +
 313 +       for (i = 0; (i < MAX_PORTS) && ports[i]; i++) {
 314 +               memset(&mms[i], 0, sizeof(struct ip_conntrack_helper));
 315 +               mms[i].tuple.src.u.tcp.port = htons(ports[i]);
 316 +               mms[i].tuple.dst.protonum = IPPROTO_TCP;
 317 +               mms[i].mask.src.u.tcp.port = 0xFFFF;
 318 +               mms[i].mask.dst.protonum = 0xFFFF;
 319 +               mms[i].max_expected = 1;
 320 +               mms[i].timeout = 0;
 321 +               mms[i].flags = IP_CT_HELPER_F_REUSE_EXPECT;
 322 +               mms[i].me = THIS_MODULE;
 323 +               mms[i].help = help;
 324 +
 325 +               tmpname = &mms_names[i][0];
 326 +               if (ports[i] == MMS_PORT)
 327 +                       sprintf(tmpname, "mms");
 328 +               else
 329 +                       sprintf(tmpname, "mms-%d", ports[i]);
 330 +               mms[i].name = tmpname;
 331 +
 332 +               DEBUGP("ip_conntrack_mms: registering helper for port %d\n",
 333 +                               ports[i]);
 334 +               ret = ip_conntrack_helper_register(&mms[i]);
 335 +
 336 +               if (ret) {
 337 +                       fini();
 338 +                       return ret;
 339 +               }
 340 +               ports_c++;
 341 +       }
 342 +       return 0;
 343 +}
 344 +
 345 +module_init(init);
 346 +module_exit(fini);
 347 Index: linux-2.4.35.4/net/ipv4/netfilter/ip_nat_mms.c
 348 ===================================================================
 349 --- /dev/null
 350 +++ linux-2.4.35.4/net/ipv4/netfilter/ip_nat_mms.c
 351 @@ -0,0 +1,330 @@
 352 +/* MMS extension for TCP NAT alteration.
 353 + * (C) 2002 by Filip Sneppe <filip.sneppe@cronos.be>
 354 + * based on ip_nat_ftp.c and ip_nat_irc.c
 355 + *
 356 + * ip_nat_mms.c v0.3 2002-09-22
 357 + *
 358 + *      This program is free software; you can redistribute it and/or
 359 + *      modify it under the terms of the GNU General Public License
 360 + *      as published by the Free Software Foundation; either version
 361 + *      2 of the License, or (at your option) any later version.
 362 + *
 363 + *      Module load syntax:
 364 + *      insmod ip_nat_mms.o ports=port1,port2,...port<MAX_PORTS>
 365 + *
 366 + *      Please give the ports of all MMS servers You wish to connect to.
 367 + *      If you don't specify ports, the default will be TCP port 1755.
 368 + *
 369 + *      More info on MMS protocol, firewalls and NAT:
 370 + *      http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwmt/html/MMSFirewall.asp
 371 + *      http://www.microsoft.com/windows/windowsmedia/serve/firewall.asp
 372 + *
 373 + *      The SDP project people are reverse-engineering MMS:
 374 + *      http://get.to/sdp
 375 + */
 376 +
 377 +
 378 +#include <linux/module.h>
 379 +#include <linux/netfilter_ipv4.h>
 380 +#include <linux/ip.h>
 381 +#include <linux/tcp.h>
 382 +#include <net/tcp.h>
 383 +#include <linux/netfilter_ipv4/ip_nat.h>
 384 +#include <linux/netfilter_ipv4/ip_nat_helper.h>
 385 +#include <linux/netfilter_ipv4/ip_nat_rule.h>
 386 +#include <linux/netfilter_ipv4/ip_conntrack_mms.h>
 387 +#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
 388 +
 389 +#define DEBUGP(format, args...)
 390 +#define DUMP_BYTES(address, counter)
 391 +
 392 +#define MAX_PORTS 8
 393 +static int ports[MAX_PORTS];
 394 +static int ports_c = 0;
 395 +
 396 +#ifdef MODULE_PARM
 397 +MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_PORTS) "i");
 398 +#endif
 399 +
 400 +MODULE_AUTHOR("Filip Sneppe <filip.sneppe@cronos.be>");
 401 +MODULE_DESCRIPTION("Microsoft Windows Media Services (MMS) NAT module");
 402 +MODULE_LICENSE("GPL");
 403 +
 404 +DECLARE_LOCK_EXTERN(ip_mms_lock);
 405 +
 406 +
 407 +static int mms_data_fixup(const struct ip_ct_mms_expect *ct_mms_info,
 408 +                          struct ip_conntrack *ct,
 409 +                          struct sk_buff **pskb,
 410 +                          enum ip_conntrack_info ctinfo,
 411 +                          struct ip_conntrack_expect *expect)
 412 +{
 413 +       u_int32_t newip;
 414 +       struct ip_conntrack_tuple t;
 415 +       struct iphdr *iph = (*pskb)->nh.iph;
 416 +       struct tcphdr *tcph = (void *) iph + iph->ihl * 4;
 417 +       char *data = (char *)tcph + tcph->doff * 4;
 418 +       int i, j, k, port;
 419 +       u_int16_t mms_proto;
 420 +
 421 +       u_int32_t *mms_chunkLenLV    = (u_int32_t *)(data + MMS_SRV_CHUNKLENLV_OFFSET);
 422 +       u_int32_t *mms_chunkLenLM    = (u_int32_t *)(data + MMS_SRV_CHUNKLENLM_OFFSET);
 423 +       u_int32_t *mms_messageLength = (u_int32_t *)(data + MMS_SRV_MESSAGELENGTH_OFFSET);
 424 +
 425 +       int zero_padding;
 426 +
 427 +       char buffer[28];         /* "\\255.255.255.255\UDP\65635" * 2 (for unicode) */
 428 +       char unicode_buffer[75]; /* 27*2 (unicode) + 20 + 1 */
 429 +       char proto_string[6];
 430 +
 431 +       MUST_BE_LOCKED(&ip_mms_lock);
 432 +
 433 +       /* what was the protocol again ? */
 434 +       mms_proto = expect->tuple.dst.protonum;
 435 +       sprintf(proto_string, "%u", mms_proto);
 436 +
 437 +       DEBUGP("ip_nat_mms: mms_data_fixup: info (seq %u + %u) in %u, proto %s\n",
 438 +              expect->seq, ct_mms_info->len, ntohl(tcph->seq),
 439 +              mms_proto == IPPROTO_UDP ? "UDP"
 440 +              : mms_proto == IPPROTO_TCP ? "TCP":proto_string);
 441 +
 442 +       newip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
 443 +
 444 +       /* Alter conntrack's expectations. */
 445 +       t = expect->tuple;
 446 +       t.dst.ip = newip;
 447 +       for (port = ct_mms_info->port; port != 0; port++) {
 448 +               t.dst.u.tcp.port = htons(port);
 449 +               if (ip_conntrack_change_expect(expect, &t) == 0) {
 450 +                       DEBUGP("ip_nat_mms: mms_data_fixup: using port %d\n", port);
 451 +                       break;
 452 +               }
 453 +       }
 454 +
 455 +       if(port == 0)
 456 +               return 0;
 457 +
 458 +       sprintf(buffer, "\\\\%u.%u.%u.%u\\%s\\%u",
 459 +               NIPQUAD(newip),
 460 +               expect->tuple.dst.protonum == IPPROTO_UDP ? "UDP"
 461 +               : expect->tuple.dst.protonum == IPPROTO_TCP ? "TCP":proto_string,
 462 +               port);
 463 +       DEBUGP("ip_nat_mms: new unicode string=%s\n", buffer);
 464 +
 465 +       memset(unicode_buffer, 0, sizeof(char)*75);
 466 +
 467 +       for (i=0; i<strlen(buffer); ++i)
 468 +               *(unicode_buffer+i*2)=*(buffer+i);
 469 +
 470 +       DEBUGP("ip_nat_mms: mms_data_fixup: padding: %u len: %u\n", ct_mms_info->padding, ct_mms_info->len);
 471 +       DEBUGP("ip_nat_mms: mms_data_fixup: offset: %u\n", MMS_SRV_UNICODE_STRING_OFFSET+ct_mms_info->len);
 472 +       DUMP_BYTES(data+MMS_SRV_UNICODE_STRING_OFFSET, 60);
 473 +
 474 +       /* add end of packet to it */
 475 +       for (j=0; j<ct_mms_info->padding; ++j) {
 476 +               DEBUGP("ip_nat_mms: mms_data_fixup: i=%u j=%u byte=%u\n",
 477 +                      i, j, (u8)*(data+MMS_SRV_UNICODE_STRING_OFFSET+ct_mms_info->len+j));
 478 +               *(unicode_buffer+i*2+j) = *(data+MMS_SRV_UNICODE_STRING_OFFSET+ct_mms_info->len+j);
 479 +       }
 480 +
 481 +       /* pad with zeroes at the end ? see explanation of weird math below */
 482 +       zero_padding = (8-(strlen(buffer)*2 + ct_mms_info->padding + 4)%8)%8;
 483 +       for (k=0; k<zero_padding; ++k)
 484 +               *(unicode_buffer+i*2+j+k)= (char)0;
 485 +
 486 +       DEBUGP("ip_nat_mms: mms_data_fixup: zero_padding = %u\n", zero_padding);
 487 +       DEBUGP("ip_nat_mms: original=> chunkLenLV=%u chunkLenLM=%u messageLength=%u\n",
 488 +              *mms_chunkLenLV, *mms_chunkLenLM, *mms_messageLength);
 489 +
 490 +       /* explanation, before I forget what I did:
 491 +          strlen(buffer)*2 + ct_mms_info->padding + 4 must be divisable by 8;
 492 +          divide by 8 and add 3 to compute the mms_chunkLenLM field,
 493 +          but note that things may have to be padded with zeroes to align by 8
 494 +          bytes, hence we add 7 and divide by 8 to get the correct length */
 495 +       *mms_chunkLenLM    = (u_int32_t) (3+(strlen(buffer)*2+ct_mms_info->padding+11)/8);
 496 +       *mms_chunkLenLV    = *mms_chunkLenLM+2;
 497 +       *mms_messageLength = *mms_chunkLenLV*8;
 498 +
 499 +       DEBUGP("ip_nat_mms: modified=> chunkLenLV=%u chunkLenLM=%u messageLength=%u\n",
 500 +              *mms_chunkLenLV, *mms_chunkLenLM, *mms_messageLength);
 501 +
 502 +       ip_nat_mangle_tcp_packet(pskb, ct, ctinfo,
 503 +                                expect->seq - ntohl(tcph->seq),
 504 +                                ct_mms_info->len + ct_mms_info->padding, unicode_buffer,
 505 +                                strlen(buffer)*2 + ct_mms_info->padding + zero_padding);
 506 +       DUMP_BYTES(unicode_buffer, 60);
 507 +
 508 +       return 1;
 509 +}
 510 +
 511 +static unsigned int
 512 +mms_nat_expected(struct sk_buff **pskb,
 513 +                 unsigned int hooknum,
 514 +                 struct ip_conntrack *ct,
 515 +                 struct ip_nat_info *info)
 516 +{
 517 +       struct ip_nat_multi_range mr;
 518 +       u_int32_t newdstip, newsrcip, newip;
 519 +
 520 +       struct ip_conntrack *master = master_ct(ct);
 521 +
 522 +       IP_NF_ASSERT(info);
 523 +       IP_NF_ASSERT(master);
 524 +
 525 +       IP_NF_ASSERT(!(info->initialized & (1 << HOOK2MANIP(hooknum))));
 526 +
 527 +       DEBUGP("ip_nat_mms: mms_nat_expected: We have a connection!\n");
 528 +
 529 +       newdstip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
 530 +       newsrcip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
 531 +       DEBUGP("ip_nat_mms: mms_nat_expected: hook %s: newsrc->newdst %u.%u.%u.%u->%u.%u.%u.%u\n",
 532 +              hooknum == NF_IP_POST_ROUTING ? "POSTROUTING"
 533 +              : hooknum == NF_IP_PRE_ROUTING ? "PREROUTING"
 534 +              : hooknum == NF_IP_LOCAL_OUT ? "OUTPUT" : "???",
 535 +              NIPQUAD(newsrcip), NIPQUAD(newdstip));
 536 +
 537 +       if (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC)
 538 +               newip = newsrcip;
 539 +       else
 540 +               newip = newdstip;
 541 +
 542 +       DEBUGP("ip_nat_mms: mms_nat_expected: IP to %u.%u.%u.%u\n", NIPQUAD(newip));
 543 +
 544 +       mr.rangesize = 1;
 545 +       /* We don't want to manip the per-protocol, just the IPs. */
 546 +       mr.range[0].flags = IP_NAT_RANGE_MAP_IPS;
 547 +       mr.range[0].min_ip = mr.range[0].max_ip = newip;
 548 +
 549 +       return ip_nat_setup_info(ct, &mr, hooknum);
 550 +}
 551 +
 552 +
 553 +static unsigned int mms_nat_help(struct ip_conntrack *ct,
 554 +                        struct ip_conntrack_expect *exp,
 555 +                        struct ip_nat_info *info,
 556 +                        enum ip_conntrack_info ctinfo,
 557 +                        unsigned int hooknum,
 558 +                        struct sk_buff **pskb)
 559 +{
 560 +       struct iphdr *iph = (*pskb)->nh.iph;
 561 +       struct tcphdr *tcph = (void *) iph + iph->ihl * 4;
 562 +       unsigned int datalen;
 563 +       int dir;
 564 +       struct ip_ct_mms_expect *ct_mms_info;
 565 +
 566 +       if (!exp)
 567 +               DEBUGP("ip_nat_mms: no exp!!");
 568 +
 569 +       ct_mms_info = &exp->help.exp_mms_info;
 570 +
 571 +       /* Only mangle things once: original direction in POST_ROUTING
 572 +          and reply direction on PRE_ROUTING. */
 573 +       dir = CTINFO2DIR(ctinfo);
 574 +       if (!((hooknum == NF_IP_POST_ROUTING && dir == IP_CT_DIR_ORIGINAL)
 575 +           ||(hooknum == NF_IP_PRE_ROUTING && dir == IP_CT_DIR_REPLY))) {
 576 +               DEBUGP("ip_nat_mms: mms_nat_help: not touching dir %s at hook %s\n",
 577 +                      dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY",
 578 +                      hooknum == NF_IP_POST_ROUTING ? "POSTROUTING"
 579 +                      : hooknum == NF_IP_PRE_ROUTING ? "PREROUTING"
 580 +                      : hooknum == NF_IP_LOCAL_OUT ? "OUTPUT" : "???");
 581 +               return NF_ACCEPT;
 582 +       }
 583 +       DEBUGP("ip_nat_mms: mms_nat_help: beyond not touching (dir %s at hook %s)\n",
 584 +              dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY",
 585 +              hooknum == NF_IP_POST_ROUTING ? "POSTROUTING"
 586 +              : hooknum == NF_IP_PRE_ROUTING ? "PREROUTING"
 587 +              : hooknum == NF_IP_LOCAL_OUT ? "OUTPUT" : "???");
 588 +
 589 +       datalen = (*pskb)->len - iph->ihl * 4 - tcph->doff * 4;
 590 +
 591 +       DEBUGP("ip_nat_mms: mms_nat_help: %u+%u=%u %u %u\n", exp->seq, ct_mms_info->len,
 592 +              exp->seq + ct_mms_info->len,
 593 +              ntohl(tcph->seq),
 594 +              ntohl(tcph->seq) + datalen);
 595 +
 596 +       LOCK_BH(&ip_mms_lock);
 597 +       /* Check wether the whole IP/proto/port pattern is carried in the payload */
 598 +       if (between(exp->seq + ct_mms_info->len,
 599 +           ntohl(tcph->seq),
 600 +           ntohl(tcph->seq) + datalen)) {
 601 +               if (!mms_data_fixup(ct_mms_info, ct, pskb, ctinfo, exp)) {
 602 +                       UNLOCK_BH(&ip_mms_lock);
 603 +                       return NF_DROP;
 604 +               }
 605 +       } else {
 606 +               /* Half a match?  This means a partial retransmisison.
 607 +                  It's a cracker being funky. */
 608 +               if (net_ratelimit()) {
 609 +                       printk("ip_nat_mms: partial packet %u/%u in %u/%u\n",
 610 +                              exp->seq, ct_mms_info->len,
 611 +                              ntohl(tcph->seq),
 612 +                              ntohl(tcph->seq) + datalen);
 613 +               }
 614 +               UNLOCK_BH(&ip_mms_lock);
 615 +               return NF_DROP;
 616 +       }
 617 +       UNLOCK_BH(&ip_mms_lock);
 618 +
 619 +       return NF_ACCEPT;
 620 +}
 621 +
 622 +static struct ip_nat_helper mms[MAX_PORTS];
 623 +static char mms_names[MAX_PORTS][10];
 624 +
 625 +/* Not __exit: called from init() */
 626 +static void fini(void)
 627 +{
 628 +       int i;
 629 +
 630 +       for (i = 0; (i < MAX_PORTS) && ports[i]; i++) {
 631 +               DEBUGP("ip_nat_mms: unregistering helper for port %d\n", ports[i]);
 632 +               ip_nat_helper_unregister(&mms[i]);
 633 +       }
 634 +}
 635 +
 636 +static int __init init(void)
 637 +{
 638 +       int i, ret = 0;
 639 +       char *tmpname;
 640 +
 641 +       if (ports[0] == 0)
 642 +               ports[0] = MMS_PORT;
 643 +
 644 +       for (i = 0; (i < MAX_PORTS) && ports[i]; i++) {
 645 +
 646 +               memset(&mms[i], 0, sizeof(struct ip_nat_helper));
 647 +
 648 +               mms[i].tuple.dst.protonum = IPPROTO_TCP;
 649 +               mms[i].tuple.src.u.tcp.port = htons(ports[i]);
 650 +               mms[i].mask.dst.protonum = 0xFFFF;
 651 +               mms[i].mask.src.u.tcp.port = 0xFFFF;
 652 +               mms[i].help = mms_nat_help;
 653 +               mms[i].me = THIS_MODULE;
 654 +               mms[i].flags = 0;
 655 +               mms[i].expect = mms_nat_expected;
 656 +
 657 +               tmpname = &mms_names[i][0];
 658 +               if (ports[i] == MMS_PORT)
 659 +                       sprintf(tmpname, "mms");
 660 +               else
 661 +                       sprintf(tmpname, "mms-%d", i);
 662 +               mms[i].name = tmpname;
 663 +
 664 +               DEBUGP("ip_nat_mms: register helper for port %d\n",
 665 +                               ports[i]);
 666 +               ret = ip_nat_helper_register(&mms[i]);
 667 +
 668 +               if (ret) {
 669 +                       printk("ip_nat_mms: error registering "
 670 +                              "helper for port %d\n", ports[i]);
 671 +                       fini();
 672 +                       return ret;
 673 +               }
 674 +               ports_c++;
 675 +       }
 676 +
 677 +       return ret;
 678 +}
 679 +
 680 +module_init(init);
 681 +module_exit(fini);
 682 Index: linux-2.4.35.4/include/linux/netfilter_ipv4/ip_conntrack.h
 683 ===================================================================
 684 --- linux-2.4.35.4.orig/include/linux/netfilter_ipv4/ip_conntrack.h
 685 +++ linux-2.4.35.4/include/linux/netfilter_ipv4/ip_conntrack.h
 686 @@ -73,6 +73,7 @@ union ip_conntrack_expect_proto {
 687  #include <linux/netfilter_ipv4/ip_conntrack_pptp.h>
 688  #include <linux/netfilter_ipv4/ip_conntrack_h323.h>
 689  #include <linux/netfilter_ipv4/ip_conntrack_rtsp.h>
 690 +#include <linux/netfilter_ipv4/ip_conntrack_mms.h>
 691
 692  /* per expectation: application helper private data */
 693  union ip_conntrack_expect_help {
 694 @@ -83,6 +84,7 @@ union ip_conntrack_expect_help {
 695         struct ip_ct_pptp_expect exp_pptp_info;
 696         struct ip_ct_h225_expect exp_h225_info;
 697         struct ip_ct_rtsp_expect exp_rtsp_info;
 698 +       struct ip_ct_mms_expect exp_mms_info;
 699
 700  #ifdef CONFIG_IP_NF_NAT_NEEDED
 701         union {
 702 @@ -99,6 +101,7 @@ union ip_conntrack_help {
 703         struct ip_ct_pptp_master ct_pptp_info;
 704         struct ip_ct_h225_master ct_h225_info;
 705         struct ip_ct_rtsp_master ct_rtsp_info;
 706 +       struct ip_ct_mms_master ct_mms_info;
 707  };
 708
 709  #ifdef CONFIG_IP_NF_NAT_NEEDED
 710 Index: linux-2.4.35.4/include/linux/netfilter_ipv4/ip_conntrack_mms.h
 711 ===================================================================
 712 --- /dev/null
 713 +++ linux-2.4.35.4/include/linux/netfilter_ipv4/ip_conntrack_mms.h
 714 @@ -0,0 +1,31 @@
 715 +#ifndef _IP_CONNTRACK_MMS_H
 716 +#define _IP_CONNTRACK_MMS_H
 717 +/* MMS tracking. */
 718 +
 719 +#ifdef __KERNEL__
 720 +#include <linux/netfilter_ipv4/lockhelp.h>
 721 +
 722 +DECLARE_LOCK_EXTERN(ip_mms_lock);
 723 +
 724 +#define MMS_PORT                         1755
 725 +#define MMS_SRV_MSG_ID                   196610
 726 +
 727 +#define MMS_SRV_MSG_OFFSET               36
 728 +#define MMS_SRV_UNICODE_STRING_OFFSET    60
 729 +#define MMS_SRV_CHUNKLENLV_OFFSET        16
 730 +#define MMS_SRV_CHUNKLENLM_OFFSET        32
 731 +#define MMS_SRV_MESSAGELENGTH_OFFSET     8
 732 +#endif
 733 +
 734 +/* This structure is per expected connection */
 735 +struct ip_ct_mms_expect {
 736 +       u_int32_t len;
 737 +       u_int32_t padding;
 738 +       u_int16_t port;
 739 +};
 740 +
 741 +/* This structure exists only once per master */
 742 +struct ip_ct_mms_master {
 743 +};
 744 +
 745 +#endif /* _IP_CONNTRACK_MMS_H */