kernel-nf_rtsp.patch

   1 diff -purN linux-2.6.23-rc2.orig/include/linux/netfilter_helpers.h linux-2.6.23-rc2/include/linux/netfilter_helpers.h
   2 --- linux-2.6.23-rc2.orig/include/linux/netfilter_helpers.h     1970-01-01 01:00:00.000000000 +0100
   3 +++ linux-2.6.23-rc2/include/linux/netfilter_helpers.h  2007-08-05 10:53:55.000000000 +0200
   4 @@ -0,0 +1,133 @@
   5 +/*
   6 + * Helpers for netfiler modules.  This file provides implementations for basic
   7 + * functions such as strncasecmp(), etc.
   8 + *
   9 + * gcc will warn for defined but unused functions, so we only include the
  10 + * functions requested.  The following macros are used:
  11 + *   NF_NEED_STRNCASECMP        nf_strncasecmp()
  12 + *   NF_NEED_STRTOU16           nf_strtou16()
  13 + *   NF_NEED_STRTOU32           nf_strtou32()
  14 + */
  15 +#ifndef _NETFILTER_HELPERS_H
  16 +#define _NETFILTER_HELPERS_H
  17 +
  18 +/* Only include these functions for kernel code. */
  19 +#ifdef __KERNEL__
  20 +
  21 +#include <linux/ctype.h>
  22 +#define iseol(c) ( (c) == '\r' || (c) == '\n' )
  23 +
  24 +/*
  25 + * The standard strncasecmp()
  26 + */
  27 +#ifdef NF_NEED_STRNCASECMP
  28 +static int
  29 +nf_strncasecmp(const char* s1, const char* s2, u_int32_t len)
  30 +{
  31 +    if (s1 == NULL || s2 == NULL)
  32 +    {
  33 +        if (s1 == NULL && s2 == NULL)
  34 +        {
  35 +            return 0;
  36 +        }
  37 +        return (s1 == NULL) ? -1 : 1;
  38 +    }
  39 +    while (len > 0 && tolower(*s1) == tolower(*s2))
  40 +    {
  41 +        len--;
  42 +        s1++;
  43 +        s2++;
  44 +    }
  45 +    return ( (len == 0) ? 0 : (tolower(*s1) - tolower(*s2)) );
  46 +}
  47 +#endif /* NF_NEED_STRNCASECMP */
  48 +
  49 +/*
  50 + * Parse a string containing a 16-bit unsigned integer.
  51 + * Returns the number of chars used, or zero if no number is found.
  52 + */
  53 +#ifdef NF_NEED_STRTOU16
  54 +static int
  55 +nf_strtou16(const char* pbuf, u_int16_t* pval)
  56 +{
  57 +    int n = 0;
  58 +
  59 +    *pval = 0;
  60 +    while (isdigit(pbuf[n]))
  61 +    {
  62 +        *pval = (*pval * 10) + (pbuf[n] - '0');
  63 +        n++;
  64 +    }
  65 +
  66 +    return n;
  67 +}
  68 +#endif /* NF_NEED_STRTOU16 */
  69 +
  70 +/*
  71 + * Parse a string containing a 32-bit unsigned integer.
  72 + * Returns the number of chars used, or zero if no number is found.
  73 + */
  74 +#ifdef NF_NEED_STRTOU32
  75 +static int
  76 +nf_strtou32(const char* pbuf, u_int32_t* pval)
  77 +{
  78 +    int n = 0;
  79 +
  80 +    *pval = 0;
  81 +    while (pbuf[n] >= '0' && pbuf[n] <= '9')
  82 +    {
  83 +        *pval = (*pval * 10) + (pbuf[n] - '0');
  84 +        n++;
  85 +    }
  86 +
  87 +    return n;
  88 +}
  89 +#endif /* NF_NEED_STRTOU32 */
  90 +
  91 +/*
  92 + * Given a buffer and length, advance to the next line and mark the current
  93 + * line.
  94 + */
  95 +#ifdef NF_NEED_NEXTLINE
  96 +static int
  97 +nf_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
  98 +{
  99 +    uint    off = *poff;
 100 +    uint    physlen = 0;
 101 +
 102 +    if (off >= len)
 103 +    {
 104 +        return 0;
 105 +    }
 106 +
 107 +    while (p[off] != '\n')
 108 +    {
 109 +        if (len-off <= 1)
 110 +        {
 111 +            return 0;
 112 +        }
 113 +
 114 +        physlen++;
 115 +        off++;
 116 +    }
 117 +
 118 +    /* if we saw a crlf, physlen needs adjusted */
 119 +    if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
 120 +    {
 121 +        physlen--;
 122 +    }
 123 +
 124 +    /* advance past the newline */
 125 +    off++;
 126 +
 127 +    *plineoff = *poff;
 128 +    *plinelen = physlen;
 129 +    *poff = off;
 130 +
 131 +    return 1;
 132 +}
 133 +#endif /* NF_NEED_NEXTLINE */
 134 +
 135 +#endif /* __KERNEL__ */
 136 +
 137 +#endif /* _NETFILTER_HELPERS_H */
 138 diff -purN linux-2.6.23-rc2.orig/include/linux/netfilter_mime.h linux-2.6.23-rc2/include/linux/netfilter_mime.h
 139 --- linux-2.6.23-rc2.orig/include/linux/netfilter_mime.h        1970-01-01 01:00:00.000000000 +0100
 140 +++ linux-2.6.23-rc2/include/linux/netfilter_mime.h     2007-08-05 10:53:55.000000000 +0200
 141 @@ -0,0 +1,89 @@
 142 +/*
 143 + * MIME functions for netfilter modules.  This file provides implementations
 144 + * for basic MIME parsing.  MIME headers are used in many protocols, such as
 145 + * HTTP, RTSP, SIP, etc.
 146 + *
 147 + * gcc will warn for defined but unused functions, so we only include the
 148 + * functions requested.  The following macros are used:
 149 + *   NF_NEED_MIME_NEXTLINE      nf_mime_nextline()
 150 + */
 151 +#ifndef _NETFILTER_MIME_H
 152 +#define _NETFILTER_MIME_H
 153 +
 154 +/* Only include these functions for kernel code. */
 155 +#ifdef __KERNEL__
 156 +
 157 +#include <linux/ctype.h>
 158 +
 159 +/*
 160 + * Given a buffer and length, advance to the next line and mark the current
 161 + * line.  If the current line is empty, *plinelen will be set to zero.  If
 162 + * not, it will be set to the actual line length (including CRLF).
 163 + *
 164 + * 'line' in this context means logical line (includes LWS continuations).
 165 + * Returns 1 on success, 0 on failure.
 166 + */
 167 +#ifdef NF_NEED_MIME_NEXTLINE
 168 +static int
 169 +nf_mime_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
 170 +{
 171 +    uint    off = *poff;
 172 +    uint    physlen = 0;
 173 +    int     is_first_line = 1;
 174 +
 175 +    if (off >= len)
 176 +    {
 177 +        return 0;
 178 +    }
 179 +
 180 +    do
 181 +    {
 182 +        while (p[off] != '\n')
 183 +        {
 184 +            if (len-off <= 1)
 185 +            {
 186 +                return 0;
 187 +            }
 188 +
 189 +            physlen++;
 190 +            off++;
 191 +        }
 192 +
 193 +        /* if we saw a crlf, physlen needs adjusted */
 194 +        if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
 195 +        {
 196 +            physlen--;
 197 +        }
 198 +
 199 +        /* advance past the newline */
 200 +        off++;
 201 +
 202 +        /* check for an empty line */
 203 +        if (physlen == 0)
 204 +        {
 205 +            break;
 206 +        }
 207 +
 208 +        /* check for colon on the first physical line */
 209 +        if (is_first_line)
 210 +        {
 211 +            is_first_line = 0;
 212 +            if (memchr(p+(*poff), ':', physlen) == NULL)
 213 +            {
 214 +                return 0;
 215 +            }
 216 +        }
 217 +    }
 218 +    while (p[off] == ' ' || p[off] == '\t');
 219 +
 220 +    *plineoff = *poff;
 221 +    *plinelen = (physlen == 0) ? 0 : (off - *poff);
 222 +    *poff = off;
 223 +
 224 +    return 1;
 225 +}
 226 +#endif /* NF_NEED_MIME_NEXTLINE */
 227 +
 228 +#endif /* __KERNEL__ */
 229 +
 230 +#endif /* _NETFILTER_MIME_H */
 231 diff -purN linux-2.6.23-rc2.orig/net/ipv4/netfilter/Kconfig linux-2.6.23-rc2/net/ipv4/netfilter/Kconfig
 232 --- linux-2.6.23-rc2.orig/net/ipv4/netfilter/Kconfig    2007-08-05 21:17:01.000000000 +0200
 233 +++ linux-2.6.23-rc2/net/ipv4/netfilter/Kconfig 2007-08-05 11:04:59.000000000 +0200
 234 @@ -274,6 +274,11 @@ config NF_NAT_IRC
 235         depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
 236         default NF_NAT && NF_CONNTRACK_IRC
 237
 238 +config NF_NAT_RTSP
 239 +       tristate
 240 +       depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
 241 +       default NF_NAT && NF_CONNTRACK_RTSP
 242 +
 243  config NF_NAT_TFTP
 244         tristate
 245         depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
 246 diff -purN linux-2.6.23-rc2.orig/net/ipv4/netfilter/Makefile linux-2.6.23-rc2/net/ipv4/netfilter/Makefile
 247 --- linux-2.6.23-rc2.orig/net/ipv4/netfilter/Makefile   2007-08-05 21:14:19.000000000 +0200
 248 +++ linux-2.6.23-rc2/net/ipv4/netfilter/Makefile        2007-08-05 10:53:55.000000000 +0200
 249 @@ -0,0 +0,1 @@
 250 +obj-$(CONFIG_NF_NAT_RTSP) += nf_nat_rtsp.o
 251 diff -purN linux-2.6.23-rc2.orig/net/netfilter/Kconfig linux-2.6.23-rc2/net/netfilter/Kconfig
 252 --- linux-2.6.23-rc2.orig/net/netfilter/Kconfig 2007-08-05 21:17:02.000000000 +0200
 253 +++ linux-2.6.23-rc2/net/netfilter/Kconfig      2007-08-05 11:04:59.000000000 +0200
 254 @@ -249,6 +249,16 @@ config NF_CONNTRACK_TFTP
 255
 256           To compile it as a module, choose M here.  If unsure, say N.
 257
 258 +config NF_CONNTRACK_RTSP
 259 +       tristate "RTSP protocol support"
 260 +       depends on NF_CONNTRACK
 261 +       help
 262 +               Support the RTSP protocol.  This allows UDP transports to be setup
 263 +               properly, including RTP and RDT.
 264 +
 265 +               If you want to compile it as a module, say 'M' here and read
 266 +               Documentation/modules.txt.  If unsure, say 'Y'.
 267 +
 268  config NF_CONNTRACK_MMS
 269         tristate 'MMS protocol support'
 270         depends on NF_CONNTRACK
 271 diff -purN linux-2.6.23-rc2.orig/net/netfilter/Makefile linux-2.6.23-rc2/net/netfilter/Makefile
 272 --- linux-2.6.23-rc2.orig/net/netfilter/Makefile        2007-08-05 21:17:02.000000000 +0200
 273 +++ linux-2.6.23-rc2/net/netfilter/Makefile     2007-08-05 11:04:59.000000000 +0200
 274 @@ -0,0 +0,1 @@
 275 +obj-$(CONFIG_NF_CONNTRACK_RTSP) += nf_conntrack_rtsp.o
 276 diff -purN linux-2.6.24-rc1.orig/include/linux/netfilter/nf_conntrack_rtsp.h linux-2.6.24-rc1/include/linux/netfilter/nf_conntrack_rtsp.h
 277 --- linux-2.6.24-rc1.orig/include/linux/netfilter/nf_conntrack_rtsp.h   1970-01-01 01:00:00.000000000 +0100
 278 +++ linux-2.6.24-rc1/include/linux/netfilter/nf_conntrack_rtsp.h        2007-11-10 17:16:36.000000000 +0100
 279 @@ -0,0 +1,63 @@
 280 +/*
 281 + * RTSP extension for IP connection tracking.
 282 + * (C) 2003 by Tom Marshall <tmarshall at real.com>
 283 + * based on ip_conntrack_irc.h
 284 + *
 285 + *      This program is free software; you can redistribute it and/or
 286 + *      modify it under the terms of the GNU General Public License
 287 + *      as published by the Free Software Foundation; either version
 288 + *      2 of the License, or (at your option) any later version.
 289 + */
 290 +#ifndef _IP_CONNTRACK_RTSP_H
 291 +#define _IP_CONNTRACK_RTSP_H
 292 +
 293 +//#define IP_NF_RTSP_DEBUG 1
 294 +#define IP_NF_RTSP_VERSION "0.6.21"
 295 +
 296 +#ifdef __KERNEL__
 297 +/* port block types */
 298 +typedef enum {
 299 +    pb_single,  /* client_port=x */
 300 +    pb_range,   /* client_port=x-y */
 301 +    pb_discon   /* client_port=x/y (rtspbis) */
 302 +} portblock_t;
 303 +
 304 +/* We record seq number and length of rtsp headers here, all in host order. */
 305 +
 306 +/*
 307 + * This structure is per expected connection.  It is a member of struct
 308 + * ip_conntrack_expect.  The TCP SEQ for the conntrack expect is stored
 309 + * there and we are expected to only store the length of the data which
 310 + * needs replaced.  If a packet contains multiple RTSP messages, we create
 311 + * one expected connection per message.
 312 + *
 313 + * We use these variables to mark the entire header block.  This may seem
 314 + * like overkill, but the nature of RTSP requires it.  A header may appear
 315 + * multiple times in a message.  We must treat two Transport headers the
 316 + * same as one Transport header with two entries.
 317 + */
 318 +struct ip_ct_rtsp_expect
 319 +{
 320 +    u_int32_t   len;        /* length of header block */
 321 +    portblock_t pbtype;     /* Type of port block that was requested */
 322 +    u_int16_t   loport;     /* Port that was requested, low or first */
 323 +    u_int16_t   hiport;     /* Port that was requested, high or second */
 324 +#if 0
 325 +    uint        method;     /* RTSP method */
 326 +    uint        cseq;       /* CSeq from request */
 327 +#endif
 328 +};
 329 +
 330 +extern unsigned int (*nf_nat_rtsp_hook)(struct sk_buff *skb,
 331 +                                enum ip_conntrack_info ctinfo,
 332 +                                unsigned int matchoff, unsigned int matchlen,
 333 +                                struct ip_ct_rtsp_expect *prtspexp,
 334 +                                struct nf_conntrack_expect *exp);
 335 +
 336 +extern void (*nf_nat_rtsp_hook_expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
 337 +
 338 +#define RTSP_PORT   554
 339 +
 340 +#endif /* __KERNEL__ */
 341 +
 342 +#endif /* _IP_CONNTRACK_RTSP_H */
 343 diff -purN linux-2.6.24-rc1.orig/net/ipv4/netfilter/nf_nat_rtsp.c linux-2.6.24-rc1/net/ipv4/netfilter/nf_nat_rtsp.c
 344 --- linux-2.6.24-rc1.orig/net/ipv4/netfilter/nf_nat_rtsp.c      1970-01-01 01:00:00.000000000 +0100
 345 +++ linux-2.6.24-rc1/net/ipv4/netfilter/nf_nat_rtsp.c   2007-11-10 17:17:21.000000000 +0100
 346 @@ -0,0 +1,489 @@
 347 +/*
 348 + * RTSP extension for TCP NAT alteration
 349 + * (C) 2003 by Tom Marshall <tmarshall at real.com>
 350 + * based on ip_nat_irc.c
 351 + *
 352 + *      This program is free software; you can redistribute it and/or
 353 + *      modify it under the terms of the GNU General Public License
 354 + *      as published by the Free Software Foundation; either version
 355 + *      2 of the License, or (at your option) any later version.
 356 + *
 357 + * Module load syntax:
 358 + *      insmod nf_nat_rtsp.o ports=port1,port2,...port<MAX_PORTS>
 359 + *                           stunaddr=<address>
 360 + *                           destaction=[auto|strip|none]
 361 + *
 362 + * If no ports are specified, the default will be port 554 only.
 363 + *
 364 + * stunaddr specifies the address used to detect that a client is using STUN.
 365 + * If this address is seen in the destination parameter, it is assumed that
 366 + * the client has already punched a UDP hole in the firewall, so we don't
 367 + * mangle the client_port.  If none is specified, it is autodetected.  It
 368 + * only needs to be set if you have multiple levels of NAT.  It should be
 369 + * set to the external address that the STUN clients detect.  Note that in
 370 + * this case, it will not be possible for clients to use UDP with servers
 371 + * between the NATs.
 372 + *
 373 + * If no destaction is specified, auto is used.
 374 + *   destaction=auto:  strip destination parameter if it is not stunaddr.
 375 + *   destaction=strip: always strip destination parameter (not recommended).
 376 + *   destaction=none:  do not touch destination parameter (not recommended).
 377 + */
 378 +
 379 +#include <linux/module.h>
 380 +#include <net/tcp.h>
 381 +#include <net/netfilter/nf_nat_helper.h>
 382 +#include <net/netfilter/nf_nat_rule.h>
 383 +#include <linux/netfilter/nf_conntrack_rtsp.h>
 384 +#include <net/netfilter/nf_conntrack_expect.h>
 385 +
 386 +#include <linux/inet.h>
 387 +#include <linux/ctype.h>
 388 +#define NF_NEED_STRNCASECMP
 389 +#define NF_NEED_STRTOU16
 390 +#include <linux/netfilter_helpers.h>
 391 +#define NF_NEED_MIME_NEXTLINE
 392 +#include <linux/netfilter_mime.h>
 393 +
 394 +#define MAX_PORTS       8
 395 +#define DSTACT_AUTO     0
 396 +#define DSTACT_STRIP    1
 397 +#define DSTACT_NONE     2
 398 +
 399 +static char*    stunaddr = NULL;
 400 +static char*    destaction = NULL;
 401 +
 402 +static u_int32_t extip = 0;
 403 +static int       dstact = 0;
 404 +
 405 +MODULE_AUTHOR("Tom Marshall <tmarshall at real.com>");
 406 +MODULE_DESCRIPTION("RTSP network address translation module");
 407 +MODULE_LICENSE("GPL");
 408 +module_param(stunaddr, charp, 0644);
 409 +MODULE_PARM_DESC(stunaddr, "Address for detecting STUN");
 410 +module_param(destaction, charp, 0644);
 411 +MODULE_PARM_DESC(destaction, "Action for destination parameter (auto/strip/none)");
 412 +
 413 +#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
 414 +
 415 +/*** helper functions ***/
 416 +
 417 +static void
 418 +get_skb_tcpdata(struct sk_buff* skb, char** pptcpdata, uint* ptcpdatalen)
 419 +{
 420 +    struct iphdr*   iph  = ip_hdr(skb);
 421 +    struct tcphdr*  tcph = (void *)iph + ip_hdrlen(skb);
 422 +
 423 +    *pptcpdata = (char*)tcph +  tcph->doff*4;
 424 +    *ptcpdatalen = ((char*)skb_transport_header(skb) + skb->len) - *pptcpdata;
 425 +}
 426 +
 427 +/*** nat functions ***/
 428 +
 429 +/*
 430 + * Mangle the "Transport:" header:
 431 + *   - Replace all occurences of "client_port=<spec>"
 432 + *   - Handle destination parameter
 433 + *
 434 + * In:
 435 + *   ct, ctinfo = conntrack context
 436 + *   skb        = packet
 437 + *   tranoff    = Transport header offset from TCP data
 438 + *   tranlen    = Transport header length (incl. CRLF)
 439 + *   rport_lo   = replacement low  port (host endian)
 440 + *   rport_hi   = replacement high port (host endian)
 441 + *
 442 + * Returns packet size difference.
 443 + *
 444 + * Assumes that a complete transport header is present, ending with CR or LF
 445 + */
 446 +static int
 447 +rtsp_mangle_tran(enum ip_conntrack_info ctinfo,
 448 +                 struct nf_conntrack_expect* exp,
 449 +                                                                struct ip_ct_rtsp_expect* prtspexp,
 450 +                 struct sk_buff* skb, uint tranoff, uint tranlen)
 451 +{
 452 +    char*       ptcp;
 453 +    uint        tcplen;
 454 +    char*       ptran;
 455 +    char        rbuf1[16];      /* Replacement buffer (one port) */
 456 +    uint        rbuf1len;       /* Replacement len (one port) */
 457 +    char        rbufa[16];      /* Replacement buffer (all ports) */
 458 +    uint        rbufalen;       /* Replacement len (all ports) */
 459 +    u_int32_t   newip;
 460 +    u_int16_t   loport, hiport;
 461 +    uint        off = 0;
 462 +    uint        diff;           /* Number of bytes we removed */
 463 +
 464 +    struct nf_conn *ct = exp->master;
 465 +    struct nf_conntrack_tuple *t;
 466 +
 467 +    char    szextaddr[15+1];
 468 +    uint    extaddrlen;
 469 +    int     is_stun;
 470 +
 471 +    get_skb_tcpdata(skb, &ptcp, &tcplen);
 472 +    ptran = ptcp+tranoff;
 473 +
 474 +    if (tranoff+tranlen > tcplen || tcplen-tranoff < tranlen ||
 475 +        tranlen < 10 || !iseol(ptran[tranlen-1]) ||
 476 +        nf_strncasecmp(ptran, "Transport:", 10) != 0)
 477 +    {
 478 +        pr_info("sanity check failed\n");
 479 +        return 0;
 480 +    }
 481 +    off += 10;
 482 +    SKIP_WSPACE(ptcp+tranoff, tranlen, off);
 483 +
 484 +    newip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip;
 485 +    t = &exp->tuple;
 486 +    t->dst.u3.ip = newip;
 487 +
 488 +    extaddrlen = extip ? sprintf(szextaddr, "%u.%u.%u.%u", NIPQUAD(extip))
 489 +                       : sprintf(szextaddr, "%u.%u.%u.%u", NIPQUAD(newip));
 490 +    pr_debug("stunaddr=%s (%s)\n", szextaddr, (extip?"forced":"auto"));
 491 +
 492 +    rbuf1len = rbufalen = 0;
 493 +    switch (prtspexp->pbtype)
 494 +    {
 495 +    case pb_single:
 496 +        for (loport = prtspexp->loport; loport != 0; loport++) /* XXX: improper wrap? */
 497 +        {
 498 +            t->dst.u.udp.port = htons(loport);
 499 +            if (nf_ct_expect_related(exp) == 0)
 500 +            {
 501 +                pr_debug("using port %hu\n", loport);
 502 +                break;
 503 +            }
 504 +        }
 505 +        if (loport != 0)
 506 +        {
 507 +            rbuf1len = sprintf(rbuf1, "%hu", loport);
 508 +            rbufalen = sprintf(rbufa, "%hu", loport);
 509 +        }
 510 +        break;
 511 +    case pb_range:
 512 +        for (loport = prtspexp->loport; loport != 0; loport += 2) /* XXX: improper wrap? */
 513 +        {
 514 +            t->dst.u.udp.port = htons(loport);
 515 +            if (nf_ct_expect_related(exp) == 0)
 516 +            {
 517 +                hiport = loport + 1; //~exp->mask.dst.u.udp.port;
 518 +                pr_debug("using ports %hu-%hu\n", loport, hiport);
 519 +                break;
 520 +            }
 521 +        }
 522 +        if (loport != 0)
 523 +        {
 524 +            rbuf1len = sprintf(rbuf1, "%hu", loport);
 525 +            rbufalen = sprintf(rbufa, "%hu-%hu", loport, loport+1);
 526 +        }
 527 +        break;
 528 +    case pb_discon:
 529 +        for (loport = prtspexp->loport; loport != 0; loport++) /* XXX: improper wrap? */
 530 +        {
 531 +            t->dst.u.udp.port = htons(loport);
 532 +            if (nf_ct_expect_related(exp) == 0)
 533 +            {
 534 +                pr_debug("using port %hu (1 of 2)\n", loport);
 535 +                break;
 536 +            }
 537 +        }
 538 +        for (hiport = prtspexp->hiport; hiport != 0; hiport++) /* XXX: improper wrap? */
 539 +        {
 540 +            t->dst.u.udp.port = htons(hiport);
 541 +            if (nf_ct_expect_related(exp) == 0)
 542 +            {
 543 +                pr_debug("using port %hu (2 of 2)\n", hiport);
 544 +                break;
 545 +            }
 546 +        }
 547 +        if (loport != 0 && hiport != 0)
 548 +        {
 549 +            rbuf1len = sprintf(rbuf1, "%hu", loport);
 550 +            if (hiport == loport+1)
 551 +            {
 552 +                rbufalen = sprintf(rbufa, "%hu-%hu", loport, hiport);
 553 +            }
 554 +            else
 555 +            {
 556 +                rbufalen = sprintf(rbufa, "%hu/%hu", loport, hiport);
 557 +            }
 558 +        }
 559 +        break;
 560 +    }
 561 +
 562 +    if (rbuf1len == 0)
 563 +    {
 564 +        return 0;   /* cannot get replacement port(s) */
 565 +    }
 566 +
 567 +    /* Transport: tran;field;field=val,tran;field;field=val,... */
 568 +    while (off < tranlen)
 569 +    {
 570 +        uint        saveoff;
 571 +        const char* pparamend;
 572 +        uint        nextparamoff;
 573 +
 574 +        pparamend = memchr(ptran+off, ',', tranlen-off);
 575 +        pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
 576 +        nextparamoff = pparamend-ptcp;
 577 +
 578 +        /*
 579 +         * We pass over each param twice.  On the first pass, we look for a
 580 +         * destination= field.  It is handled by the security policy.  If it
 581 +         * is present, allowed, and equal to our external address, we assume
 582 +         * that STUN is being used and we leave the client_port= field alone.
 583 +         */
 584 +        is_stun = 0;
 585 +        saveoff = off;
 586 +        while (off < nextparamoff)
 587 +        {
 588 +            const char* pfieldend;
 589 +            uint        nextfieldoff;
 590 +
 591 +            pfieldend = memchr(ptran+off, ';', nextparamoff-off);
 592 +            nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
 593 +
 594 +            if (dstact != DSTACT_NONE && strncmp(ptran+off, "destination=", 12) == 0)
 595 +            {
 596 +                if (strncmp(ptran+off+12, szextaddr, extaddrlen) == 0)
 597 +                {
 598 +                    is_stun = 1;
 599 +                }
 600 +                if (dstact == DSTACT_STRIP || (dstact == DSTACT_AUTO && !is_stun))
 601 +                {
 602 +                    diff = nextfieldoff-off;
 603 +                    if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
 604 +                                                         off, diff, NULL, 0))
 605 +                    {
 606 +                        /* mangle failed, all we can do is bail */
 607 +                       nf_ct_unexpect_related(exp);
 608 +                        return 0;
 609 +                    }
 610 +                    get_skb_tcpdata(skb, &ptcp, &tcplen);
 611 +                    ptran = ptcp+tranoff;
 612 +                    tranlen -= diff;
 613 +                    nextparamoff -= diff;
 614 +                    nextfieldoff -= diff;
 615 +                }
 616 +            }
 617 +
 618 +            off = nextfieldoff;
 619 +        }
 620 +        if (is_stun)
 621 +        {
 622 +            continue;
 623 +        }
 624 +        off = saveoff;
 625 +        while (off < nextparamoff)
 626 +        {
 627 +            const char* pfieldend;
 628 +            uint        nextfieldoff;
 629 +
 630 +            pfieldend = memchr(ptran+off, ';', nextparamoff-off);
 631 +            nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
 632 +
 633 +            if (strncmp(ptran+off, "client_port=", 12) == 0)
 634 +            {
 635 +                u_int16_t   port;
 636 +                uint        numlen;
 637 +                uint        origoff;
 638 +                uint        origlen;
 639 +                char*       rbuf    = rbuf1;
 640 +                uint        rbuflen = rbuf1len;
 641 +
 642 +                off += 12;
 643 +                origoff = (ptran-ptcp)+off;
 644 +                origlen = 0;
 645 +                numlen = nf_strtou16(ptran+off, &port);
 646 +                off += numlen;
 647 +                origlen += numlen;
 648 +                if (port != prtspexp->loport)
 649 +                {
 650 +                    pr_debug("multiple ports found, port %hu ignored\n", port);
 651 +                }
 652 +                else
 653 +                {
 654 +                    if (ptran[off] == '-' || ptran[off] == '/')
 655 +                    {
 656 +                        off++;
 657 +                        origlen++;
 658 +                        numlen = nf_strtou16(ptran+off, &port);
 659 +                        off += numlen;
 660 +                        origlen += numlen;
 661 +                        rbuf = rbufa;
 662 +                        rbuflen = rbufalen;
 663 +                    }
 664 +
 665 +                    /*
 666 +                     * note we cannot just memcpy() if the sizes are the same.
 667 +                     * the mangle function does skb resizing, checks for a
 668 +                     * cloned skb, and updates the checksums.
 669 +                     *
 670 +                     * parameter 4 below is offset from start of tcp data.
 671 +                     */
 672 +                    diff = origlen-rbuflen;
 673 +                    if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
 674 +                                              origoff, origlen, rbuf, rbuflen))
 675 +                    {
 676 +                        /* mangle failed, all we can do is bail */
 677 +                       nf_ct_unexpect_related(exp);
 678 +                        return 0;
 679 +                    }
 680 +                    get_skb_tcpdata(skb, &ptcp, &tcplen);
 681 +                    ptran = ptcp+tranoff;
 682 +                    tranlen -= diff;
 683 +                    nextparamoff -= diff;
 684 +                    nextfieldoff -= diff;
 685 +                }
 686 +            }
 687 +
 688 +            off = nextfieldoff;
 689 +        }
 690 +
 691 +        off = nextparamoff;
 692 +    }
 693 +
 694 +    return 1;
 695 +}
 696 +
 697 +static uint
 698 +help_out(struct sk_buff *skb, enum ip_conntrack_info ctinfo,
 699 +        unsigned int matchoff, unsigned int matchlen, struct ip_ct_rtsp_expect* prtspexp,
 700 +        struct nf_conntrack_expect* exp)
 701 +{
 702 +    char*   ptcp;
 703 +    uint    tcplen;
 704 +    uint    hdrsoff;
 705 +    uint    hdrslen;
 706 +    uint    lineoff;
 707 +    uint    linelen;
 708 +    uint    off;
 709 +
 710 +    //struct iphdr* iph = (struct iphdr*)(*pskb)->nh.iph;
 711 +    //struct tcphdr* tcph = (struct tcphdr*)((void*)iph + iph->ihl*4);
 712 +
 713 +    get_skb_tcpdata(skb, &ptcp, &tcplen);
 714 +    hdrsoff = matchoff;//exp->seq - ntohl(tcph->seq);
 715 +    hdrslen = matchlen;
 716 +    off = hdrsoff;
 717 +    pr_debug("NAT rtsp help_out\n");
 718 +
 719 +    while (nf_mime_nextline(ptcp, hdrsoff+hdrslen, &off, &lineoff, &linelen))
 720 +    {
 721 +        if (linelen == 0)
 722 +        {
 723 +            break;
 724 +        }
 725 +        if (off > hdrsoff+hdrslen)
 726 +        {
 727 +            pr_info("!! overrun !!");
 728 +            break;
 729 +        }
 730 +        pr_debug("hdr: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
 731 +
 732 +        if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0)
 733 +        {
 734 +            uint oldtcplen = tcplen;
 735 +           pr_debug("hdr: Transport\n");
 736 +            if (!rtsp_mangle_tran(ctinfo, exp, prtspexp, skb, lineoff, linelen))
 737 +            {
 738 +               pr_debug("hdr: Transport mangle failed");
 739 +                break;
 740 +            }
 741 +            get_skb_tcpdata(skb, &ptcp, &tcplen);
 742 +            hdrslen -= (oldtcplen-tcplen);
 743 +            off -= (oldtcplen-tcplen);
 744 +            lineoff -= (oldtcplen-tcplen);
 745 +            linelen -= (oldtcplen-tcplen);
 746 +            pr_debug("rep: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
 747 +        }
 748 +    }
 749 +
 750 +    return NF_ACCEPT;
 751 +}
 752 +
 753 +static unsigned int
 754 +help(struct sk_buff *skb, enum ip_conntrack_info ctinfo,
 755 +     unsigned int matchoff, unsigned int matchlen, struct ip_ct_rtsp_expect* prtspexp,
 756 +     struct nf_conntrack_expect* exp)
 757 +{
 758 +    int dir = CTINFO2DIR(ctinfo);
 759 +    int rc = NF_ACCEPT;
 760 +
 761 +    switch (dir)
 762 +    {
 763 +    case IP_CT_DIR_ORIGINAL:
 764 +        rc = help_out(skb, ctinfo, matchoff, matchlen, prtspexp, exp);
 765 +        break;
 766 +    case IP_CT_DIR_REPLY:
 767 +       pr_debug("unmangle ! %u\n", ctinfo);
 768 +       /* XXX: unmangle */
 769 +       rc = NF_ACCEPT;
 770 +        break;
 771 +    }
 772 +    //UNLOCK_BH(&ip_rtsp_lock);
 773 +
 774 +    return rc;
 775 +}
 776 +
 777 +static void expected(struct nf_conn* ct, struct nf_conntrack_expect *exp)
 778 +{
 779 +    struct nf_nat_multi_range_compat mr;
 780 +    u_int32_t newdstip, newsrcip, newip;
 781 +
 782 +    struct nf_conn *master = ct->master;
 783 +
 784 +    newdstip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip;
 785 +    newsrcip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip;
 786 +    //FIXME (how to port that ?)
 787 +    //code from 2.4 : newip = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC) ? newsrcip : newdstip;
 788 +    newip = newdstip;
 789 +
 790 +    pr_debug("newsrcip=%u.%u.%u.%u, newdstip=%u.%u.%u.%u, newip=%u.%u.%u.%u\n",
 791 +           NIPQUAD(newsrcip), NIPQUAD(newdstip), NIPQUAD(newip));
 792 +
 793 +    mr.rangesize = 1;
 794 +    // We don't want to manip the per-protocol, just the IPs.
 795 +    mr.range[0].flags = IP_NAT_RANGE_MAP_IPS;
 796 +    mr.range[0].min_ip = mr.range[0].max_ip = newip;
 797 +
 798 +    nf_nat_setup_info(ct, &mr.range[0], IP_NAT_MANIP_DST);
 799 +}
 800 +
 801 +
 802 +static void __exit fini(void)
 803 +{
 804 +       nf_nat_rtsp_hook = NULL;
 805 +        nf_nat_rtsp_hook_expectfn = NULL;
 806 +       synchronize_net();
 807 +}
 808 +
 809 +static int __init init(void)
 810 +{
 811 +       printk("nf_nat_rtsp v" IP_NF_RTSP_VERSION " loading\n");
 812 +
 813 +       BUG_ON(nf_nat_rtsp_hook);
 814 +       nf_nat_rtsp_hook = help;
 815 +        nf_nat_rtsp_hook_expectfn = &expected;
 816 +
 817 +       if (stunaddr != NULL)
 818 +               extip = in_aton(stunaddr);
 819 +
 820 +       if (destaction != NULL) {
 821 +               if (strcmp(destaction, "auto") == 0)
 822 +                       dstact = DSTACT_AUTO;
 823 +
 824 +               if (strcmp(destaction, "strip") == 0)
 825 +                       dstact = DSTACT_STRIP;
 826 +
 827 +               if (strcmp(destaction, "none") == 0)
 828 +                       dstact = DSTACT_NONE;
 829 +       }
 830 +
 831 +       return 0;
 832 +}
 833 +
 834 +module_init(init);
 835 +module_exit(fini);
 836 diff -purN linux-2.6.26.orig/net/netfilter/nf_conntrack_rtsp.c linux-2.6.26/net/netfilter/nf_conntrack_rtsp.c
 837 --- linux-2.6.26.orig/net/netfilter/nf_conntrack_rtsp.c 1970-01-01 01:00:00.000000000 +0100
 838 +++ linux-2.6.26/net/netfilter/nf_conntrack_rtsp.c      2008-07-24 16:19:36.000000000 +0200
 839 @@ -0,0 +1,519 @@
 840 +/*
 841 + * RTSP extension for IP connection tracking
 842 + * (C) 2003 by Tom Marshall <tmarshall at real.com>
 843 + * based on ip_conntrack_irc.c
 844 + *
 845 + *      This program is free software; you can redistribute it and/or
 846 + *      modify it under the terms of the GNU General Public License
 847 + *      as published by the Free Software Foundation; either version
 848 + *      2 of the License, or (at your option) any later version.
 849 + *
 850 + * Module load syntax:
 851 + *   insmod nf_conntrack_rtsp.o ports=port1,port2,...port<MAX_PORTS>
 852 + *                              max_outstanding=n setup_timeout=secs
 853 + *
 854 + * If no ports are specified, the default will be port 554.
 855 + *
 856 + * With max_outstanding you can define the maximum number of not yet
 857 + * answered SETUP requests per RTSP session (default 8).
 858 + * With setup_timeout you can specify how long the system waits for
 859 + * an expected data channel (default 300 seconds).
 860 + *
 861 + * 2005-02-13: Harald Welte <laforge at netfilter.org>
 862 + *     - port to 2.6
 863 + *     - update to recent post-2.6.11 api changes
 864 + * 2006-09-14: Steven Van Acker <deepstar at singularity.be>
 865 + *      - removed calls to NAT code from conntrack helper: NAT no longer needed to use rtsp-conntrack
 866 + * 2007-04-18: Michael Guntsche <mike at it-loops.com>
 867 + *                     - Port to new NF API
 868 + */
 869 +
 870 +#include <linux/module.h>
 871 +#include <linux/netfilter.h>
 872 +#include <linux/ip.h>
 873 +#include <linux/inet.h>
 874 +#include <net/tcp.h>
 875 +
 876 +#include <net/netfilter/nf_conntrack.h>
 877 +#include <net/netfilter/nf_conntrack_expect.h>
 878 +#include <net/netfilter/nf_conntrack_helper.h>
 879 +#include <linux/netfilter/nf_conntrack_rtsp.h>
 880 +
 881 +#define NF_NEED_STRNCASECMP
 882 +#define NF_NEED_STRTOU16
 883 +#define NF_NEED_STRTOU32
 884 +#define NF_NEED_NEXTLINE
 885 +#include <linux/netfilter_helpers.h>
 886 +#define NF_NEED_MIME_NEXTLINE
 887 +#include <linux/netfilter_mime.h>
 888 +
 889 +#include <linux/ctype.h>
 890 +#define MAX_SIMUL_SETUP 8 /* XXX: use max_outstanding */
 891 +
 892 +#define MAX_PORTS 8
 893 +static int ports[MAX_PORTS];
 894 +static int num_ports = 0;
 895 +static int max_outstanding = 8;
 896 +static unsigned int setup_timeout = 300;
 897 +
 898 +MODULE_AUTHOR("Tom Marshall <tmarshall at real.com>");
 899 +MODULE_DESCRIPTION("RTSP connection tracking module");
 900 +MODULE_LICENSE("GPL");
 901 +module_param_array(ports, int, &num_ports, 0400);
 902 +MODULE_PARM_DESC(ports, "port numbers of RTSP servers");
 903 +module_param(max_outstanding, int, 0400);
 904 +MODULE_PARM_DESC(max_outstanding, "max number of outstanding SETUP requests per RTSP session");
 905 +module_param(setup_timeout, int, 0400);
 906 +MODULE_PARM_DESC(setup_timeout, "timeout on for unestablished data channels");
 907 +
 908 +static char *rtsp_buffer;
 909 +static DEFINE_SPINLOCK(rtsp_buffer_lock);
 910 +
 911 +static struct nf_conntrack_expect_policy rtsp_exp_policy;
 912 +
 913 +unsigned int (*nf_nat_rtsp_hook)(struct sk_buff *skb,
 914 +                                enum ip_conntrack_info ctinfo,
 915 +                                unsigned int matchoff, unsigned int matchlen,struct ip_ct_rtsp_expect* prtspexp,
 916 +                                struct nf_conntrack_expect *exp);
 917 +void (*nf_nat_rtsp_hook_expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
 918 +
 919 +EXPORT_SYMBOL_GPL(nf_nat_rtsp_hook);
 920 +
 921 +/*
 922 + * Max mappings we will allow for one RTSP connection (for RTP, the number
 923 + * of allocated ports is twice this value).  Note that SMIL burns a lot of
 924 + * ports so keep this reasonably high.  If this is too low, you will see a
 925 + * lot of "no free client map entries" messages.
 926 + */
 927 +#define MAX_PORT_MAPS 16
 928 +
 929 +/*** default port list was here in the masq code: 554, 3030, 4040 ***/
 930 +
 931 +#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
 932 +
 933 +/*
 934 + * Parse an RTSP packet.
 935 + *
 936 + * Returns zero if parsing failed.
 937 + *
 938 + * Parameters:
 939 + *  IN      ptcp        tcp data pointer
 940 + *  IN      tcplen      tcp data len
 941 + *  IN/OUT  ptcpoff     points to current tcp offset
 942 + *  OUT     phdrsoff    set to offset of rtsp headers
 943 + *  OUT     phdrslen    set to length of rtsp headers
 944 + *  OUT     pcseqoff    set to offset of CSeq header
 945 + *  OUT     pcseqlen    set to length of CSeq header
 946 + */
 947 +static int
 948 +rtsp_parse_message(char* ptcp, uint tcplen, uint* ptcpoff,
 949 +                   uint* phdrsoff, uint* phdrslen,
 950 +                   uint* pcseqoff, uint* pcseqlen,
 951 +                   uint* transoff, uint* translen)
 952 +{
 953 +       uint    entitylen = 0;
 954 +       uint    lineoff;
 955 +       uint    linelen;
 956 +
 957 +       if (!nf_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
 958 +               return 0;
 959 +
 960 +       *phdrsoff = *ptcpoff;
 961 +       while (nf_mime_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen)) {
 962 +               if (linelen == 0) {
 963 +                       if (entitylen > 0)
 964 +                               *ptcpoff += min(entitylen, tcplen - *ptcpoff);
 965 +                       break;
 966 +               }
 967 +               if (lineoff+linelen > tcplen) {
 968 +                       pr_info("!! overrun !!\n");
 969 +                       break;
 970 +               }
 971 +
 972 +               if (nf_strncasecmp(ptcp+lineoff, "CSeq:", 5) == 0) {
 973 +                       *pcseqoff = lineoff;
 974 +                       *pcseqlen = linelen;
 975 +               }
 976 +
 977 +               if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0) {
 978 +                       *transoff = lineoff;
 979 +                       *translen = linelen;
 980 +               }
 981 +
 982 +               if (nf_strncasecmp(ptcp+lineoff, "Content-Length:", 15) == 0) {
 983 +                       uint off = lineoff+15;
 984 +                       SKIP_WSPACE(ptcp+lineoff, linelen, off);
 985 +                       nf_strtou32(ptcp+off, &entitylen);
 986 +               }
 987 +       }
 988 +       *phdrslen = (*ptcpoff) - (*phdrsoff);
 989 +
 990 +       return 1;
 991 +}
 992 +
 993 +/*
 994 + * Find lo/hi client ports (if any) in transport header
 995 + * In:
 996 + *   ptcp, tcplen = packet
 997 + *   tranoff, tranlen = buffer to search
 998 + *
 999 + * Out:
1000 + *   pport_lo, pport_hi = lo/hi ports (host endian)
1001 + *
1002 + * Returns nonzero if any client ports found
1003 + *
1004 + * Note: it is valid (and expected) for the client to request multiple
1005 + * transports, so we need to parse the entire line.
1006 + */
1007 +static int
1008 +rtsp_parse_transport(char* ptran, uint tranlen,
1009 +                     struct ip_ct_rtsp_expect* prtspexp)
1010 +{
1011 +       int     rc = 0;
1012 +       uint    off = 0;
1013 +
1014 +       if (tranlen < 10 || !iseol(ptran[tranlen-1]) ||
1015 +           nf_strncasecmp(ptran, "Transport:", 10) != 0) {
1016 +               pr_info("sanity check failed\n");
1017 +               return 0;
1018 +       }
1019 +
1020 +       pr_debug("tran='%.*s'\n", (int)tranlen, ptran);
1021 +       off += 10;
1022 +       SKIP_WSPACE(ptran, tranlen, off);
1023 +
1024 +       /* Transport: tran;field;field=val,tran;field;field=val,... */
1025 +       while (off < tranlen) {
1026 +               const char* pparamend;
1027 +               uint        nextparamoff;
1028 +
1029 +               pparamend = memchr(ptran+off, ',', tranlen-off);
1030 +               pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
1031 +               nextparamoff = pparamend-ptran;
1032 +
1033 +               while (off < nextparamoff) {
1034 +                       const char* pfieldend;
1035 +                       uint        nextfieldoff;
1036 +
1037 +                       pfieldend = memchr(ptran+off, ';', nextparamoff-off);
1038 +                       nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
1039 +
1040 +                       if (strncmp(ptran+off, "client_port=", 12) == 0) {
1041 +                               u_int16_t   port;
1042 +                               uint        numlen;
1043 +
1044 +                               off += 12;
1045 +                               numlen = nf_strtou16(ptran+off, &port);
1046 +                               off += numlen;
1047 +                               if (prtspexp->loport != 0 && prtspexp->loport != port)
1048 +                                       pr_debug("multiple ports found, port %hu ignored\n", port);
1049 +                               else {
1050 +                                       pr_debug("lo port found : %hu\n", port);
1051 +                                       prtspexp->loport = prtspexp->hiport = port;
1052 +                                       if (ptran[off] == '-') {
1053 +                                               off++;
1054 +                                               numlen = nf_strtou16(ptran+off, &port);
1055 +                                               off += numlen;
1056 +                                               prtspexp->pbtype = pb_range;
1057 +                                               prtspexp->hiport = port;
1058 +
1059 +                                               // If we have a range, assume rtp:
1060 +                                               // loport must be even, hiport must be loport+1
1061 +                                               if ((prtspexp->loport & 0x0001) != 0 ||
1062 +                                                   prtspexp->hiport != prtspexp->loport+1) {
1063 +                                                       pr_debug("incorrect range: %hu-%hu, correcting\n",
1064 +                                                              prtspexp->loport, prtspexp->hiport);
1065 +                                                       prtspexp->loport &= 0xfffe;
1066 +                                                       prtspexp->hiport = prtspexp->loport+1;
1067 +                                               }
1068 +                                       } else if (ptran[off] == '/') {
1069 +                                               off++;
1070 +                                               numlen = nf_strtou16(ptran+off, &port);
1071 +                                               off += numlen;
1072 +                                               prtspexp->pbtype = pb_discon;
1073 +                                               prtspexp->hiport = port;
1074 +                                       }
1075 +                                       rc = 1;
1076 +                               }
1077 +                       }
1078 +
1079 +                       /*
1080 +                        * Note we don't look for the destination parameter here.
1081 +                        * If we are using NAT, the NAT module will handle it.  If not,
1082 +                        * and the client is sending packets elsewhere, the expectation
1083 +                        * will quietly time out.
1084 +                        */
1085 +
1086 +                       off = nextfieldoff;
1087 +               }
1088 +
1089 +               off = nextparamoff;
1090 +       }
1091 +
1092 +       return rc;
1093 +}
1094 +
1095 +void expected(struct nf_conn *ct, struct nf_conntrack_expect *exp)
1096 +{
1097 +               typeof(nf_nat_rtsp_hook_expectfn) nf_nat_rtsp_expectfn;
1098 +               nf_nat_rtsp_expectfn = rcu_dereference(nf_nat_rtsp_hook_expectfn);
1099 +    if(nf_nat_rtsp_expectfn && ct->master->status & IPS_NAT_MASK) {
1100 +        nf_nat_rtsp_expectfn(ct,exp);
1101 +    }
1102 +}
1103 +
1104 +/*** conntrack functions ***/
1105 +
1106 +/* outbound packet: client->server */
1107 +
1108 +static inline int
1109 +help_out(struct sk_buff *skb, unsigned char *rb_ptr, unsigned int datalen,
1110 +                struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1111 +{
1112 +       struct ip_ct_rtsp_expect expinfo;
1113 +
1114 +       int dir = CTINFO2DIR(ctinfo);   /* = IP_CT_DIR_ORIGINAL */
1115 +       //struct  tcphdr* tcph = (void*)iph + iph->ihl * 4;
1116 +       //uint    tcplen = pktlen - iph->ihl * 4;
1117 +       char*   pdata = rb_ptr;
1118 +       //uint    datalen = tcplen - tcph->doff * 4;
1119 +       uint    dataoff = 0;
1120 +       int ret = NF_ACCEPT;
1121 +
1122 +       struct nf_conntrack_expect *exp;
1123 +
1124 +       __be16 be_loport;
1125 +
1126 +       typeof(nf_nat_rtsp_hook) nf_nat_rtsp;
1127 +
1128 +       memset(&expinfo, 0, sizeof(expinfo));
1129 +
1130 +       while (dataoff < datalen) {
1131 +               uint    cmdoff = dataoff;
1132 +               uint    hdrsoff = 0;
1133 +               uint    hdrslen = 0;
1134 +               uint    cseqoff = 0;
1135 +               uint    cseqlen = 0;
1136 +               uint    transoff = 0;
1137 +               uint    translen = 0;
1138 +               uint    off;
1139 +
1140 +               if (!rtsp_parse_message(pdata, datalen, &dataoff,
1141 +                                       &hdrsoff, &hdrslen,
1142 +                                       &cseqoff, &cseqlen,
1143 +                                       &transoff, &translen))
1144 +                       break;      /* not a valid message */
1145 +
1146 +               if (strncmp(pdata+cmdoff, "SETUP ", 6) != 0)
1147 +                       continue;   /* not a SETUP message */
1148 +               pr_debug("found a setup message\n");
1149 +
1150 +               off = 0;
1151 +               if(translen) {
1152 +                       rtsp_parse_transport(pdata+transoff, translen, &expinfo);
1153 +               }
1154 +
1155 +               if (expinfo.loport == 0) {
1156 +                       pr_debug("no udp transports found\n");
1157 +                       continue;   /* no udp transports found */
1158 +               }
1159 +
1160 +               pr_debug("udp transport found, ports=(%d,%hu,%hu)\n",
1161 +                      (int)expinfo.pbtype, expinfo.loport, expinfo.hiport);
1162 +
1163 +               exp = nf_ct_expect_alloc(ct);
1164 +               if (!exp) {
1165 +                       ret = NF_DROP;
1166 +                       goto out;
1167 +               }
1168 +
1169 +               be_loport = htons(expinfo.loport);
1170 +
1171 +               nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1172 +                       &ct->tuplehash[!dir].tuple.src.u3, &ct->tuplehash[!dir].tuple.dst.u3,
1173 +                       IPPROTO_UDP, NULL, &be_loport);
1174 +
1175 +               exp->master = ct;
1176 +
1177 +               exp->expectfn = expected;
1178 +               exp->flags = 0;
1179 +
1180 +               if (expinfo.pbtype == pb_range) {
1181 +                       pr_debug("Changing expectation mask to handle multiple ports\n");
1182 +                       //exp->mask.dst.u.udp.port  = 0xfffe;
1183 +               }
1184 +
1185 +               pr_debug("expect_related %u.%u.%u.%u:%u-%u.%u.%u.%u:%u\n",
1186 +                      NIPQUAD(exp->tuple.src.u3.ip),
1187 +                      ntohs(exp->tuple.src.u.udp.port),
1188 +                      NIPQUAD(exp->tuple.dst.u3.ip),
1189 +                      ntohs(exp->tuple.dst.u.udp.port));
1190 +
1191 +               nf_nat_rtsp = rcu_dereference(nf_nat_rtsp_hook);
1192 +               if (nf_nat_rtsp && ct->status & IPS_NAT_MASK)
1193 +                       /* pass the request off to the nat helper */
1194 +                       ret = nf_nat_rtsp(skb, ctinfo, hdrsoff, hdrslen, &expinfo, exp);
1195 +               else if (nf_ct_expect_related(exp) != 0) {
1196 +                       pr_info("nf_conntrack_expect_related failed\n");
1197 +                       ret  = NF_DROP;
1198 +               }
1199 +               nf_ct_expect_put(exp);
1200 +               goto out;
1201 +       }
1202 +out:
1203 +
1204 +       return ret;
1205 +}
1206 +
1207 +
1208 +static inline int
1209 +help_in(struct sk_buff *skb, size_t pktlen,
1210 + struct nf_conn* ct, enum ip_conntrack_info ctinfo)
1211 +{
1212 + return NF_ACCEPT;
1213 +}
1214 +
1215 +static int help(struct sk_buff *skb, unsigned int protoff,
1216 +               struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1217 +{
1218 +       struct tcphdr _tcph, *th;
1219 +       unsigned int dataoff, datalen;
1220 +       char *rb_ptr;
1221 +       int ret = NF_DROP;
1222 +
1223 +       /* Until there's been traffic both ways, don't look in packets. */
1224 +       if (ctinfo != IP_CT_ESTABLISHED &&
1225 +           ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
1226 +               pr_debug("conntrackinfo = %u\n", ctinfo);
1227 +               return NF_ACCEPT;
1228 +       }
1229 +
1230 +       /* Not whole TCP header? */
1231 +       th = skb_header_pointer(skb,protoff, sizeof(_tcph), &_tcph);
1232 +
1233 +       if (!th)
1234 +               return NF_ACCEPT;
1235 +
1236 +       /* No data ? */
1237 +       dataoff = protoff + th->doff*4;
1238 +       datalen = skb->len - dataoff;
1239 +       if (dataoff >= skb->len)
1240 +               return NF_ACCEPT;
1241 +
1242 +       spin_lock_bh(&rtsp_buffer_lock);
1243 +       rb_ptr = skb_header_pointer(skb, dataoff,
1244 +                                   skb->len - dataoff, rtsp_buffer);
1245 +       BUG_ON(rb_ptr == NULL);
1246 +
1247 +#if 0
1248 +       /* Checksum invalid?  Ignore. */
1249 +       /* FIXME: Source route IP option packets --RR */
1250 +       if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
1251 +                        csum_partial((char*)tcph, tcplen, 0)))
1252 +       {
1253 +               DEBUGP("bad csum: %p %u %u.%u.%u.%u %u.%u.%u.%u\n",
1254 +                      tcph, tcplen, NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
1255 +               return NF_ACCEPT;
1256 +       }
1257 +#endif
1258 +
1259 +       switch (CTINFO2DIR(ctinfo)) {
1260 +       case IP_CT_DIR_ORIGINAL:
1261 +               ret = help_out(skb, rb_ptr, datalen, ct, ctinfo);
1262 +               break;
1263 +       case IP_CT_DIR_REPLY:
1264 +               pr_debug("IP_CT_DIR_REPLY\n");
1265 +               /* inbound packet: server->client */
1266 +               ret = NF_ACCEPT;
1267 +               break;
1268 +       }
1269 +
1270 +       spin_unlock_bh(&rtsp_buffer_lock);
1271 +
1272 +       return ret;
1273 +}
1274 +
1275 +static struct nf_conntrack_helper rtsp_helpers[MAX_PORTS];
1276 +static char rtsp_names[MAX_PORTS][10];
1277 +
1278 +/* This function is intentionally _NOT_ defined as __exit */
1279 +static void
1280 +fini(void)
1281 +{
1282 +       int i;
1283 +       for (i = 0; i < num_ports; i++) {
1284 +               pr_debug("unregistering port %d\n", ports[i]);
1285 +               nf_conntrack_helper_unregister(&rtsp_helpers[i]);
1286 +       }
1287 +       kfree(rtsp_buffer);
1288 +}
1289 +
1290 +static int __init
1291 +init(void)
1292 +{
1293 +       int i, ret;
1294 +       struct nf_conntrack_helper *hlpr;
1295 +       char *tmpname;
1296 +
1297 +       printk("nf_conntrack_rtsp v" IP_NF_RTSP_VERSION " loading\n");
1298 +
1299 +       if (max_outstanding < 1) {
1300 +               printk("nf_conntrack_rtsp: max_outstanding must be a positive integer\n");
1301 +               return -EBUSY;
1302 +       }
1303 +       if (setup_timeout < 0) {
1304 +               printk("nf_conntrack_rtsp: setup_timeout must be a positive integer\n");
1305 +               return -EBUSY;
1306 +       }
1307 +
1308 +  rtsp_exp_policy.max_expected = max_outstanding;
1309 +  rtsp_exp_policy.timeout = setup_timeout;
1310 +
1311 +       rtsp_buffer = kmalloc(65536, GFP_KERNEL);
1312 +       if (!rtsp_buffer)
1313 +               return -ENOMEM;
1314 +
1315 +       /* If no port given, default to standard rtsp port */
1316 +       if (ports[0] == 0) {
1317 +               ports[0] = RTSP_PORT;
1318 +       }
1319 +
1320 +       for (i = 0; (i < MAX_PORTS) && ports[i]; i++) {
1321 +               hlpr = &rtsp_helpers[i];
1322 +               memset(hlpr, 0, sizeof(struct nf_conntrack_helper));
1323 +               hlpr->tuple.src.l3num = AF_INET;
1324 +               hlpr->tuple.src.u.tcp.port = htons(ports[i]);
1325 +               hlpr->tuple.dst.protonum = IPPROTO_TCP;
1326 +               //hlpr->mask.src.u.tcp.port = 0xFFFF;
1327 +               //hlpr->mask.dst.protonum = 0xFF;
1328 +               hlpr->expect_policy = &rtsp_exp_policy;
1329 +               hlpr->me = THIS_MODULE;
1330 +               hlpr->help = help;
1331 +
1332 +               tmpname = &rtsp_names[i][0];
1333 +               if (ports[i] == RTSP_PORT) {
1334 +                       sprintf(tmpname, "rtsp");
1335 +               } else {
1336 +                       sprintf(tmpname, "rtsp-%d", i);
1337 +               }
1338 +               hlpr->name = tmpname;
1339 +
1340 +               pr_debug("port #%d: %d\n", i, ports[i]);
1341 +
1342 +               ret = nf_conntrack_helper_register(hlpr);
1343 +
1344 +               if (ret) {
1345 +                       printk("nf_conntrack_rtsp: ERROR registering port %d\n", ports[i]);
1346 +                       fini();
1347 +                       return -EBUSY;
1348 +               }
1349 +               num_ports++;
1350 +       }
1351 +       return 0;
1352 +}
1353 +
1354 +module_init(init);
1355 +module_exit(fini);
1356 +
1357 +EXPORT_SYMBOL(nf_nat_rtsp_hook_expectfn);
1358 +