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 +1,139 @@
   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 +#define NIPQUAD(addr) \
 136 +       ((unsigned char *)&addr)[0], \
 137 +       ((unsigned char *)&addr)[1], \
 138 +       ((unsigned char *)&addr)[2], \
 139 +       ((unsigned char *)&addr)[3]
 140 +
 141 +#endif /* __KERNEL__ */
 142 +
 143 +#endif /* _NETFILTER_HELPERS_H */
 144 diff -purN linux-2.6.23-rc2.orig/include/linux/netfilter_mime.h linux-2.6.23-rc2/include/linux/netfilter_mime.h
 145 --- linux-2.6.23-rc2.orig/include/linux/netfilter_mime.h        1970-01-01 01:00:00.000000000 +0100
 146 +++ linux-2.6.23-rc2/include/linux/netfilter_mime.h     2007-08-05 10:53:55.000000000 +0200
 147 @@ -0,0 +1,89 @@
 148 +/*
 149 + * MIME functions for netfilter modules.  This file provides implementations
 150 + * for basic MIME parsing.  MIME headers are used in many protocols, such as
 151 + * HTTP, RTSP, SIP, etc.
 152 + *
 153 + * gcc will warn for defined but unused functions, so we only include the
 154 + * functions requested.  The following macros are used:
 155 + *   NF_NEED_MIME_NEXTLINE      nf_mime_nextline()
 156 + */
 157 +#ifndef _NETFILTER_MIME_H
 158 +#define _NETFILTER_MIME_H
 159 +
 160 +/* Only include these functions for kernel code. */
 161 +#ifdef __KERNEL__
 162 +
 163 +#include <linux/ctype.h>
 164 +
 165 +/*
 166 + * Given a buffer and length, advance to the next line and mark the current
 167 + * line.  If the current line is empty, *plinelen will be set to zero.  If
 168 + * not, it will be set to the actual line length (including CRLF).
 169 + *
 170 + * 'line' in this context means logical line (includes LWS continuations).
 171 + * Returns 1 on success, 0 on failure.
 172 + */
 173 +#ifdef NF_NEED_MIME_NEXTLINE
 174 +static int
 175 +nf_mime_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
 176 +{
 177 +    uint    off = *poff;
 178 +    uint    physlen = 0;
 179 +    int     is_first_line = 1;
 180 +
 181 +    if (off >= len)
 182 +    {
 183 +        return 0;
 184 +    }
 185 +
 186 +    do
 187 +    {
 188 +        while (p[off] != '\n')
 189 +        {
 190 +            if (len-off <= 1)
 191 +            {
 192 +                return 0;
 193 +            }
 194 +
 195 +            physlen++;
 196 +            off++;
 197 +        }
 198 +
 199 +        /* if we saw a crlf, physlen needs adjusted */
 200 +        if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
 201 +        {
 202 +            physlen--;
 203 +        }
 204 +
 205 +        /* advance past the newline */
 206 +        off++;
 207 +
 208 +        /* check for an empty line */
 209 +        if (physlen == 0)
 210 +        {
 211 +            break;
 212 +        }
 213 +
 214 +        /* check for colon on the first physical line */
 215 +        if (is_first_line)
 216 +        {
 217 +            is_first_line = 0;
 218 +            if (memchr(p+(*poff), ':', physlen) == NULL)
 219 +            {
 220 +                return 0;
 221 +            }
 222 +        }
 223 +    }
 224 +    while (p[off] == ' ' || p[off] == '\t');
 225 +
 226 +    *plineoff = *poff;
 227 +    *plinelen = (physlen == 0) ? 0 : (off - *poff);
 228 +    *poff = off;
 229 +
 230 +    return 1;
 231 +}
 232 +#endif /* NF_NEED_MIME_NEXTLINE */
 233 +
 234 +#endif /* __KERNEL__ */
 235 +
 236 +#endif /* _NETFILTER_MIME_H */
 237 diff -purN linux-2.6.23-rc2.orig/net/ipv4/netfilter/Kconfig linux-2.6.23-rc2/net/ipv4/netfilter/Kconfig
 238 --- linux-2.6.23-rc2.orig/net/ipv4/netfilter/Kconfig    2007-08-05 21:17:01.000000000 +0200
 239 +++ linux-2.6.23-rc2/net/ipv4/netfilter/Kconfig 2007-08-05 11:04:59.000000000 +0200
 240 @@ -274,6 +274,11 @@ config NF_NAT_IRC
 241         depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
 242         default NF_NAT && NF_CONNTRACK_IRC
 243
 244 +config NF_NAT_RTSP
 245 +       tristate
 246 +       depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
 247 +       default NF_NAT && NF_CONNTRACK_RTSP
 248 +
 249  config NF_NAT_TFTP
 250         tristate
 251         depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
 252 diff -purN linux-2.6.23-rc2.orig/net/ipv4/netfilter/Makefile linux-2.6.23-rc2/net/ipv4/netfilter/Makefile
 253 --- linux-2.6.23-rc2.orig/net/ipv4/netfilter/Makefile   2007-08-05 21:14:19.000000000 +0200
 254 +++ linux-2.6.23-rc2/net/ipv4/netfilter/Makefile        2007-08-05 10:53:55.000000000 +0200
 255 @@ -0,0 +1 @@
 256 +obj-$(CONFIG_NF_NAT_RTSP) += nf_nat_rtsp.o
 257 diff -purN linux-2.6.23-rc2.orig/net/netfilter/Kconfig linux-2.6.23-rc2/net/netfilter/Kconfig
 258 --- linux-2.6.23-rc2.orig/net/netfilter/Kconfig 2007-08-05 21:17:02.000000000 +0200
 259 +++ linux-2.6.23-rc2/net/netfilter/Kconfig      2007-08-05 11:04:59.000000000 +0200
 260 @@ -249,6 +249,16 @@ config NF_CONNTRACK_TFTP
 261
 262           To compile it as a module, choose M here.  If unsure, say N.
 263
 264 +config NF_CONNTRACK_RTSP
 265 +       tristate "RTSP protocol support"
 266 +       depends on NF_CONNTRACK
 267 +       help
 268 +               Support the RTSP protocol.  This allows UDP transports to be setup
 269 +               properly, including RTP and RDT.
 270 +
 271 +               If you want to compile it as a module, say 'M' here and read
 272 +               Documentation/modules.txt.  If unsure, say 'Y'.
 273 +
 274  config NF_CONNTRACK_MMS
 275         tristate 'MMS protocol support'
 276         depends on NF_CONNTRACK
 277 diff -purN linux-2.6.23-rc2.orig/net/netfilter/Makefile linux-2.6.23-rc2/net/netfilter/Makefile
 278 --- linux-2.6.23-rc2.orig/net/netfilter/Makefile        2007-08-05 21:17:02.000000000 +0200
 279 +++ linux-2.6.23-rc2/net/netfilter/Makefile     2007-08-05 11:04:59.000000000 +0200
 280 @@ -0,0 +1 @@
 281 +obj-$(CONFIG_NF_CONNTRACK_RTSP) += nf_conntrack_rtsp.o
 282 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
 283 --- linux-2.6.24-rc1.orig/include/linux/netfilter/nf_conntrack_rtsp.h   1970-01-01 01:00:00.000000000 +0100
 284 +++ linux-2.6.24-rc1/include/linux/netfilter/nf_conntrack_rtsp.h        2007-11-10 17:16:36.000000000 +0100
 285 @@ -0,0 +1,63 @@
 286 +/*
 287 + * RTSP extension for IP connection tracking.
 288 + * (C) 2003 by Tom Marshall <tmarshall at real.com>
 289 + * based on ip_conntrack_irc.h
 290 + *
 291 + *      This program is free software; you can redistribute it and/or
 292 + *      modify it under the terms of the GNU General Public License
 293 + *      as published by the Free Software Foundation; either version
 294 + *      2 of the License, or (at your option) any later version.
 295 + */
 296 +#ifndef _IP_CONNTRACK_RTSP_H
 297 +#define _IP_CONNTRACK_RTSP_H
 298 +
 299 +//#define IP_NF_RTSP_DEBUG 1
 300 +#define IP_NF_RTSP_VERSION "0.6.21"
 301 +
 302 +#ifdef __KERNEL__
 303 +/* port block types */
 304 +typedef enum {
 305 +    pb_single,  /* client_port=x */
 306 +    pb_range,   /* client_port=x-y */
 307 +    pb_discon   /* client_port=x/y (rtspbis) */
 308 +} portblock_t;
 309 +
 310 +/* We record seq number and length of rtsp headers here, all in host order. */
 311 +
 312 +/*
 313 + * This structure is per expected connection.  It is a member of struct
 314 + * ip_conntrack_expect.  The TCP SEQ for the conntrack expect is stored
 315 + * there and we are expected to only store the length of the data which
 316 + * needs replaced.  If a packet contains multiple RTSP messages, we create
 317 + * one expected connection per message.
 318 + *
 319 + * We use these variables to mark the entire header block.  This may seem
 320 + * like overkill, but the nature of RTSP requires it.  A header may appear
 321 + * multiple times in a message.  We must treat two Transport headers the
 322 + * same as one Transport header with two entries.
 323 + */
 324 +struct ip_ct_rtsp_expect
 325 +{
 326 +    u_int32_t   len;        /* length of header block */
 327 +    portblock_t pbtype;     /* Type of port block that was requested */
 328 +    u_int16_t   loport;     /* Port that was requested, low or first */
 329 +    u_int16_t   hiport;     /* Port that was requested, high or second */
 330 +#if 0
 331 +    uint        method;     /* RTSP method */
 332 +    uint        cseq;       /* CSeq from request */
 333 +#endif
 334 +};
 335 +
 336 +extern unsigned int (*nf_nat_rtsp_hook)(struct sk_buff *skb,
 337 +                                enum ip_conntrack_info ctinfo,
 338 +                                unsigned int matchoff, unsigned int matchlen,
 339 +                                struct ip_ct_rtsp_expect *prtspexp,
 340 +                                struct nf_conntrack_expect *exp);
 341 +
 342 +extern void (*nf_nat_rtsp_hook_expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
 343 +
 344 +#define RTSP_PORT   554
 345 +
 346 +#endif /* __KERNEL__ */
 347 +
 348 +#endif /* _IP_CONNTRACK_RTSP_H */
 349 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
 350 --- linux-2.6.24-rc1.orig/net/ipv4/netfilter/nf_nat_rtsp.c      1970-01-01 01:00:00.000000000 +0100
 351 +++ linux-2.6.24-rc1/net/ipv4/netfilter/nf_nat_rtsp.c   2007-11-10 17:17:21.000000000 +0100
 352 @@ -0,0 +1,489 @@
 353 +/*
 354 + * RTSP extension for TCP NAT alteration
 355 + * (C) 2003 by Tom Marshall <tmarshall at real.com>
 356 + * based on ip_nat_irc.c
 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 nf_nat_rtsp.o ports=port1,port2,...port<MAX_PORTS>
 365 + *                           stunaddr=<address>
 366 + *                           destaction=[auto|strip|none]
 367 + *
 368 + * If no ports are specified, the default will be port 554 only.
 369 + *
 370 + * stunaddr specifies the address used to detect that a client is using STUN.
 371 + * If this address is seen in the destination parameter, it is assumed that
 372 + * the client has already punched a UDP hole in the firewall, so we don't
 373 + * mangle the client_port.  If none is specified, it is autodetected.  It
 374 + * only needs to be set if you have multiple levels of NAT.  It should be
 375 + * set to the external address that the STUN clients detect.  Note that in
 376 + * this case, it will not be possible for clients to use UDP with servers
 377 + * between the NATs.
 378 + *
 379 + * If no destaction is specified, auto is used.
 380 + *   destaction=auto:  strip destination parameter if it is not stunaddr.
 381 + *   destaction=strip: always strip destination parameter (not recommended).
 382 + *   destaction=none:  do not touch destination parameter (not recommended).
 383 + */
 384 +
 385 +#include <linux/module.h>
 386 +#include <net/tcp.h>
 387 +#include <net/netfilter/nf_nat_helper.h>
 388 +#include <net/netfilter/nf_nat_rule.h>
 389 +#include <linux/netfilter/nf_conntrack_rtsp.h>
 390 +#include <net/netfilter/nf_conntrack_expect.h>
 391 +
 392 +#include <linux/inet.h>
 393 +#include <linux/ctype.h>
 394 +#define NF_NEED_STRNCASECMP
 395 +#define NF_NEED_STRTOU16
 396 +#include <linux/netfilter_helpers.h>
 397 +#define NF_NEED_MIME_NEXTLINE
 398 +#include <linux/netfilter_mime.h>
 399 +
 400 +#define MAX_PORTS       8
 401 +#define DSTACT_AUTO     0
 402 +#define DSTACT_STRIP    1
 403 +#define DSTACT_NONE     2
 404 +
 405 +static char*    stunaddr = NULL;
 406 +static char*    destaction = NULL;
 407 +
 408 +static u_int32_t extip = 0;
 409 +static int       dstact = 0;
 410 +
 411 +MODULE_AUTHOR("Tom Marshall <tmarshall at real.com>");
 412 +MODULE_DESCRIPTION("RTSP network address translation module");
 413 +MODULE_LICENSE("GPL");
 414 +module_param(stunaddr, charp, 0644);
 415 +MODULE_PARM_DESC(stunaddr, "Address for detecting STUN");
 416 +module_param(destaction, charp, 0644);
 417 +MODULE_PARM_DESC(destaction, "Action for destination parameter (auto/strip/none)");
 418 +
 419 +#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
 420 +
 421 +/*** helper functions ***/
 422 +
 423 +static void
 424 +get_skb_tcpdata(struct sk_buff* skb, char** pptcpdata, uint* ptcpdatalen)
 425 +{
 426 +    struct iphdr*   iph  = ip_hdr(skb);
 427 +    struct tcphdr*  tcph = (void *)iph + ip_hdrlen(skb);
 428 +
 429 +    *pptcpdata = (char*)tcph +  tcph->doff*4;
 430 +    *ptcpdatalen = ((char*)skb_transport_header(skb) + skb->len) - *pptcpdata;
 431 +}
 432 +
 433 +/*** nat functions ***/
 434 +
 435 +/*
 436 + * Mangle the "Transport:" header:
 437 + *   - Replace all occurences of "client_port=<spec>"
 438 + *   - Handle destination parameter
 439 + *
 440 + * In:
 441 + *   ct, ctinfo = conntrack context
 442 + *   skb        = packet
 443 + *   tranoff    = Transport header offset from TCP data
 444 + *   tranlen    = Transport header length (incl. CRLF)
 445 + *   rport_lo   = replacement low  port (host endian)
 446 + *   rport_hi   = replacement high port (host endian)
 447 + *
 448 + * Returns packet size difference.
 449 + *
 450 + * Assumes that a complete transport header is present, ending with CR or LF
 451 + */
 452 +static int
 453 +rtsp_mangle_tran(enum ip_conntrack_info ctinfo,
 454 +                 struct nf_conntrack_expect* exp,
 455 +                                                                struct ip_ct_rtsp_expect* prtspexp,
 456 +                 struct sk_buff* skb, uint tranoff, uint tranlen)
 457 +{
 458 +    char*       ptcp;
 459 +    uint        tcplen;
 460 +    char*       ptran;
 461 +    char        rbuf1[16];      /* Replacement buffer (one port) */
 462 +    uint        rbuf1len;       /* Replacement len (one port) */
 463 +    char        rbufa[16];      /* Replacement buffer (all ports) */
 464 +    uint        rbufalen;       /* Replacement len (all ports) */
 465 +    u_int32_t   newip;
 466 +    u_int16_t   loport, hiport;
 467 +    uint        off = 0;
 468 +    uint        diff;           /* Number of bytes we removed */
 469 +
 470 +    struct nf_conn *ct = exp->master;
 471 +    struct nf_conntrack_tuple *t;
 472 +
 473 +    char    szextaddr[15+1];
 474 +    uint    extaddrlen;
 475 +    int     is_stun;
 476 +
 477 +    get_skb_tcpdata(skb, &ptcp, &tcplen);
 478 +    ptran = ptcp+tranoff;
 479 +
 480 +    if (tranoff+tranlen > tcplen || tcplen-tranoff < tranlen ||
 481 +        tranlen < 10 || !iseol(ptran[tranlen-1]) ||
 482 +        nf_strncasecmp(ptran, "Transport:", 10) != 0)
 483 +    {
 484 +        pr_info("sanity check failed\n");
 485 +        return 0;
 486 +    }
 487 +    off += 10;
 488 +    SKIP_WSPACE(ptcp+tranoff, tranlen, off);
 489 +
 490 +    newip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip;
 491 +    t = &exp->tuple;
 492 +    t->dst.u3.ip = newip;
 493 +
 494 +    extaddrlen = extip ? sprintf(szextaddr, "%u.%u.%u.%u", NIPQUAD(extip))
 495 +                       : sprintf(szextaddr, "%u.%u.%u.%u", NIPQUAD(newip));
 496 +    pr_debug("stunaddr=%s (%s)\n", szextaddr, (extip?"forced":"auto"));
 497 +
 498 +    rbuf1len = rbufalen = 0;
 499 +    switch (prtspexp->pbtype)
 500 +    {
 501 +    case pb_single:
 502 +        for (loport = prtspexp->loport; loport != 0; loport++) /* XXX: improper wrap? */
 503 +        {
 504 +            t->dst.u.udp.port = htons(loport);
 505 +            if (nf_ct_expect_related(exp) == 0)
 506 +            {
 507 +                pr_debug("using port %hu\n", loport);
 508 +                break;
 509 +            }
 510 +        }
 511 +        if (loport != 0)
 512 +        {
 513 +            rbuf1len = sprintf(rbuf1, "%hu", loport);
 514 +            rbufalen = sprintf(rbufa, "%hu", loport);
 515 +        }
 516 +        break;
 517 +    case pb_range:
 518 +        for (loport = prtspexp->loport; loport != 0; loport += 2) /* XXX: improper wrap? */
 519 +        {
 520 +            t->dst.u.udp.port = htons(loport);
 521 +            if (nf_ct_expect_related(exp) == 0)
 522 +            {
 523 +                hiport = loport + 1; //~exp->mask.dst.u.udp.port;
 524 +                pr_debug("using ports %hu-%hu\n", loport, hiport);
 525 +                break;
 526 +            }
 527 +        }
 528 +        if (loport != 0)
 529 +        {
 530 +            rbuf1len = sprintf(rbuf1, "%hu", loport);
 531 +            rbufalen = sprintf(rbufa, "%hu-%hu", loport, loport+1);
 532 +        }
 533 +        break;
 534 +    case pb_discon:
 535 +        for (loport = prtspexp->loport; loport != 0; loport++) /* XXX: improper wrap? */
 536 +        {
 537 +            t->dst.u.udp.port = htons(loport);
 538 +            if (nf_ct_expect_related(exp) == 0)
 539 +            {
 540 +                pr_debug("using port %hu (1 of 2)\n", loport);
 541 +                break;
 542 +            }
 543 +        }
 544 +        for (hiport = prtspexp->hiport; hiport != 0; hiport++) /* XXX: improper wrap? */
 545 +        {
 546 +            t->dst.u.udp.port = htons(hiport);
 547 +            if (nf_ct_expect_related(exp) == 0)
 548 +            {
 549 +                pr_debug("using port %hu (2 of 2)\n", hiport);
 550 +                break;
 551 +            }
 552 +        }
 553 +        if (loport != 0 && hiport != 0)
 554 +        {
 555 +            rbuf1len = sprintf(rbuf1, "%hu", loport);
 556 +            if (hiport == loport+1)
 557 +            {
 558 +                rbufalen = sprintf(rbufa, "%hu-%hu", loport, hiport);
 559 +            }
 560 +            else
 561 +            {
 562 +                rbufalen = sprintf(rbufa, "%hu/%hu", loport, hiport);
 563 +            }
 564 +        }
 565 +        break;
 566 +    }
 567 +
 568 +    if (rbuf1len == 0)
 569 +    {
 570 +        return 0;   /* cannot get replacement port(s) */
 571 +    }
 572 +
 573 +    /* Transport: tran;field;field=val,tran;field;field=val,... */
 574 +    while (off < tranlen)
 575 +    {
 576 +        uint        saveoff;
 577 +        const char* pparamend;
 578 +        uint        nextparamoff;
 579 +
 580 +        pparamend = memchr(ptran+off, ',', tranlen-off);
 581 +        pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
 582 +        nextparamoff = pparamend-ptcp;
 583 +
 584 +        /*
 585 +         * We pass over each param twice.  On the first pass, we look for a
 586 +         * destination= field.  It is handled by the security policy.  If it
 587 +         * is present, allowed, and equal to our external address, we assume
 588 +         * that STUN is being used and we leave the client_port= field alone.
 589 +         */
 590 +        is_stun = 0;
 591 +        saveoff = off;
 592 +        while (off < nextparamoff)
 593 +        {
 594 +            const char* pfieldend;
 595 +            uint        nextfieldoff;
 596 +
 597 +            pfieldend = memchr(ptran+off, ';', nextparamoff-off);
 598 +            nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
 599 +
 600 +            if (dstact != DSTACT_NONE && strncmp(ptran+off, "destination=", 12) == 0)
 601 +            {
 602 +                if (strncmp(ptran+off+12, szextaddr, extaddrlen) == 0)
 603 +                {
 604 +                    is_stun = 1;
 605 +                }
 606 +                if (dstact == DSTACT_STRIP || (dstact == DSTACT_AUTO && !is_stun))
 607 +                {
 608 +                    diff = nextfieldoff-off;
 609 +                    if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
 610 +                                                         off, diff, NULL, 0))
 611 +                    {
 612 +                        /* mangle failed, all we can do is bail */
 613 +                       nf_ct_unexpect_related(exp);
 614 +                        return 0;
 615 +                    }
 616 +                    get_skb_tcpdata(skb, &ptcp, &tcplen);
 617 +                    ptran = ptcp+tranoff;
 618 +                    tranlen -= diff;
 619 +                    nextparamoff -= diff;
 620 +                    nextfieldoff -= diff;
 621 +                }
 622 +            }
 623 +
 624 +            off = nextfieldoff;
 625 +        }
 626 +        if (is_stun)
 627 +        {
 628 +            continue;
 629 +        }
 630 +        off = saveoff;
 631 +        while (off < nextparamoff)
 632 +        {
 633 +            const char* pfieldend;
 634 +            uint        nextfieldoff;
 635 +
 636 +            pfieldend = memchr(ptran+off, ';', nextparamoff-off);
 637 +            nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
 638 +
 639 +            if (strncmp(ptran+off, "client_port=", 12) == 0)
 640 +            {
 641 +                u_int16_t   port;
 642 +                uint        numlen;
 643 +                uint        origoff;
 644 +                uint        origlen;
 645 +                char*       rbuf    = rbuf1;
 646 +                uint        rbuflen = rbuf1len;
 647 +
 648 +                off += 12;
 649 +                origoff = (ptran-ptcp)+off;
 650 +                origlen = 0;
 651 +                numlen = nf_strtou16(ptran+off, &port);
 652 +                off += numlen;
 653 +                origlen += numlen;
 654 +                if (port != prtspexp->loport)
 655 +                {
 656 +                    pr_debug("multiple ports found, port %hu ignored\n", port);
 657 +                }
 658 +                else
 659 +                {
 660 +                    if (ptran[off] == '-' || ptran[off] == '/')
 661 +                    {
 662 +                        off++;
 663 +                        origlen++;
 664 +                        numlen = nf_strtou16(ptran+off, &port);
 665 +                        off += numlen;
 666 +                        origlen += numlen;
 667 +                        rbuf = rbufa;
 668 +                        rbuflen = rbufalen;
 669 +                    }
 670 +
 671 +                    /*
 672 +                     * note we cannot just memcpy() if the sizes are the same.
 673 +                     * the mangle function does skb resizing, checks for a
 674 +                     * cloned skb, and updates the checksums.
 675 +                     *
 676 +                     * parameter 4 below is offset from start of tcp data.
 677 +                     */
 678 +                    diff = origlen-rbuflen;
 679 +                    if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
 680 +                                              origoff, origlen, rbuf, rbuflen))
 681 +                    {
 682 +                        /* mangle failed, all we can do is bail */
 683 +                       nf_ct_unexpect_related(exp);
 684 +                        return 0;
 685 +                    }
 686 +                    get_skb_tcpdata(skb, &ptcp, &tcplen);
 687 +                    ptran = ptcp+tranoff;
 688 +                    tranlen -= diff;
 689 +                    nextparamoff -= diff;
 690 +                    nextfieldoff -= diff;
 691 +                }
 692 +            }
 693 +
 694 +            off = nextfieldoff;
 695 +        }
 696 +
 697 +        off = nextparamoff;
 698 +    }
 699 +
 700 +    return 1;
 701 +}
 702 +
 703 +static uint
 704 +help_out(struct sk_buff *skb, enum ip_conntrack_info ctinfo,
 705 +        unsigned int matchoff, unsigned int matchlen, struct ip_ct_rtsp_expect* prtspexp,
 706 +        struct nf_conntrack_expect* exp)
 707 +{
 708 +    char*   ptcp;
 709 +    uint    tcplen;
 710 +    uint    hdrsoff;
 711 +    uint    hdrslen;
 712 +    uint    lineoff;
 713 +    uint    linelen;
 714 +    uint    off;
 715 +
 716 +    //struct iphdr* iph = (struct iphdr*)(*pskb)->nh.iph;
 717 +    //struct tcphdr* tcph = (struct tcphdr*)((void*)iph + iph->ihl*4);
 718 +
 719 +    get_skb_tcpdata(skb, &ptcp, &tcplen);
 720 +    hdrsoff = matchoff;//exp->seq - ntohl(tcph->seq);
 721 +    hdrslen = matchlen;
 722 +    off = hdrsoff;
 723 +    pr_debug("NAT rtsp help_out\n");
 724 +
 725 +    while (nf_mime_nextline(ptcp, hdrsoff+hdrslen, &off, &lineoff, &linelen))
 726 +    {
 727 +        if (linelen == 0)
 728 +        {
 729 +            break;
 730 +        }
 731 +        if (off > hdrsoff+hdrslen)
 732 +        {
 733 +            pr_info("!! overrun !!");
 734 +            break;
 735 +        }
 736 +        pr_debug("hdr: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
 737 +
 738 +        if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0)
 739 +        {
 740 +            uint oldtcplen = tcplen;
 741 +           pr_debug("hdr: Transport\n");
 742 +            if (!rtsp_mangle_tran(ctinfo, exp, prtspexp, skb, lineoff, linelen))
 743 +            {
 744 +               pr_debug("hdr: Transport mangle failed");
 745 +                break;
 746 +            }
 747 +            get_skb_tcpdata(skb, &ptcp, &tcplen);
 748 +            hdrslen -= (oldtcplen-tcplen);
 749 +            off -= (oldtcplen-tcplen);
 750 +            lineoff -= (oldtcplen-tcplen);
 751 +            linelen -= (oldtcplen-tcplen);
 752 +            pr_debug("rep: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
 753 +        }
 754 +    }
 755 +
 756 +    return NF_ACCEPT;
 757 +}
 758 +
 759 +static unsigned int
 760 +help(struct sk_buff *skb, enum ip_conntrack_info ctinfo,
 761 +     unsigned int matchoff, unsigned int matchlen, struct ip_ct_rtsp_expect* prtspexp,
 762 +     struct nf_conntrack_expect* exp)
 763 +{
 764 +    int dir = CTINFO2DIR(ctinfo);
 765 +    int rc = NF_ACCEPT;
 766 +
 767 +    switch (dir)
 768 +    {
 769 +    case IP_CT_DIR_ORIGINAL:
 770 +        rc = help_out(skb, ctinfo, matchoff, matchlen, prtspexp, exp);
 771 +        break;
 772 +    case IP_CT_DIR_REPLY:
 773 +       pr_debug("unmangle ! %u\n", ctinfo);
 774 +       /* XXX: unmangle */
 775 +       rc = NF_ACCEPT;
 776 +        break;
 777 +    }
 778 +    //UNLOCK_BH(&ip_rtsp_lock);
 779 +
 780 +    return rc;
 781 +}
 782 +
 783 +static void expected(struct nf_conn* ct, struct nf_conntrack_expect *exp)
 784 +{
 785 +    struct nf_nat_multi_range_compat mr;
 786 +    u_int32_t newdstip, newsrcip, newip;
 787 +
 788 +    struct nf_conn *master = ct->master;
 789 +
 790 +    newdstip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip;
 791 +    newsrcip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip;
 792 +    //FIXME (how to port that ?)
 793 +    //code from 2.4 : newip = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC) ? newsrcip : newdstip;
 794 +    newip = newdstip;
 795 +
 796 +    pr_debug("newsrcip=%u.%u.%u.%u, newdstip=%u.%u.%u.%u, newip=%u.%u.%u.%u\n",
 797 +           NIPQUAD(newsrcip), NIPQUAD(newdstip), NIPQUAD(newip));
 798 +
 799 +    mr.rangesize = 1;
 800 +    // We don't want to manip the per-protocol, just the IPs.
 801 +    mr.range[0].flags = IP_NAT_RANGE_MAP_IPS;
 802 +    mr.range[0].min_ip = mr.range[0].max_ip = newip;
 803 +
 804 +    nf_nat_setup_info(ct, &mr.range[0], IP_NAT_MANIP_DST);
 805 +}
 806 +
 807 +
 808 +static void __exit fini(void)
 809 +{
 810 +       nf_nat_rtsp_hook = NULL;
 811 +        nf_nat_rtsp_hook_expectfn = NULL;
 812 +       synchronize_net();
 813 +}
 814 +
 815 +static int __init init(void)
 816 +{
 817 +       printk("nf_nat_rtsp v" IP_NF_RTSP_VERSION " loading\n");
 818 +
 819 +       BUG_ON(nf_nat_rtsp_hook);
 820 +       nf_nat_rtsp_hook = help;
 821 +        nf_nat_rtsp_hook_expectfn = &expected;
 822 +
 823 +       if (stunaddr != NULL)
 824 +               extip = in_aton(stunaddr);
 825 +
 826 +       if (destaction != NULL) {
 827 +               if (strcmp(destaction, "auto") == 0)
 828 +                       dstact = DSTACT_AUTO;
 829 +
 830 +               if (strcmp(destaction, "strip") == 0)
 831 +                       dstact = DSTACT_STRIP;
 832 +
 833 +               if (strcmp(destaction, "none") == 0)
 834 +                       dstact = DSTACT_NONE;
 835 +       }
 836 +
 837 +       return 0;
 838 +}
 839 +
 840 +module_init(init);
 841 +module_exit(fini);
 842 diff -purN linux-2.6.26.orig/net/netfilter/nf_conntrack_rtsp.c linux-2.6.26/net/netfilter/nf_conntrack_rtsp.c
 843 --- linux-2.6.26.orig/net/netfilter/nf_conntrack_rtsp.c 1970-01-01 01:00:00.000000000 +0100
 844 +++ linux-2.6.26/net/netfilter/nf_conntrack_rtsp.c      2008-07-24 16:19:36.000000000 +0200
 845 @@ -0,0 +1,519 @@
 846 +/*
 847 + * RTSP extension for IP connection tracking
 848 + * (C) 2003 by Tom Marshall <tmarshall at real.com>
 849 + * based on ip_conntrack_irc.c
 850 + *
 851 + *      This program is free software; you can redistribute it and/or
 852 + *      modify it under the terms of the GNU General Public License
 853 + *      as published by the Free Software Foundation; either version
 854 + *      2 of the License, or (at your option) any later version.
 855 + *
 856 + * Module load syntax:
 857 + *   insmod nf_conntrack_rtsp.o ports=port1,port2,...port<MAX_PORTS>
 858 + *                              max_outstanding=n setup_timeout=secs
 859 + *
 860 + * If no ports are specified, the default will be port 554.
 861 + *
 862 + * With max_outstanding you can define the maximum number of not yet
 863 + * answered SETUP requests per RTSP session (default 8).
 864 + * With setup_timeout you can specify how long the system waits for
 865 + * an expected data channel (default 300 seconds).
 866 + *
 867 + * 2005-02-13: Harald Welte <laforge at netfilter.org>
 868 + *     - port to 2.6
 869 + *     - update to recent post-2.6.11 api changes
 870 + * 2006-09-14: Steven Van Acker <deepstar at singularity.be>
 871 + *      - removed calls to NAT code from conntrack helper: NAT no longer needed to use rtsp-conntrack
 872 + * 2007-04-18: Michael Guntsche <mike at it-loops.com>
 873 + *                     - Port to new NF API
 874 + */
 875 +
 876 +#include <linux/module.h>
 877 +#include <linux/netfilter.h>
 878 +#include <linux/ip.h>
 879 +#include <linux/inet.h>
 880 +#include <net/tcp.h>
 881 +
 882 +#include <net/netfilter/nf_conntrack.h>
 883 +#include <net/netfilter/nf_conntrack_expect.h>
 884 +#include <net/netfilter/nf_conntrack_helper.h>
 885 +#include <linux/netfilter/nf_conntrack_rtsp.h>
 886 +
 887 +#define NF_NEED_STRNCASECMP
 888 +#define NF_NEED_STRTOU16
 889 +#define NF_NEED_STRTOU32
 890 +#define NF_NEED_NEXTLINE
 891 +#include <linux/netfilter_helpers.h>
 892 +#define NF_NEED_MIME_NEXTLINE
 893 +#include <linux/netfilter_mime.h>
 894 +
 895 +#include <linux/ctype.h>
 896 +#define MAX_SIMUL_SETUP 8 /* XXX: use max_outstanding */
 897 +
 898 +#define MAX_PORTS 8
 899 +static int ports[MAX_PORTS];
 900 +static int num_ports = 0;
 901 +static int max_outstanding = 8;
 902 +static unsigned int setup_timeout = 300;
 903 +
 904 +MODULE_AUTHOR("Tom Marshall <tmarshall at real.com>");
 905 +MODULE_DESCRIPTION("RTSP connection tracking module");
 906 +MODULE_LICENSE("GPL");
 907 +module_param_array(ports, int, &num_ports, 0400);
 908 +MODULE_PARM_DESC(ports, "port numbers of RTSP servers");
 909 +module_param(max_outstanding, int, 0400);
 910 +MODULE_PARM_DESC(max_outstanding, "max number of outstanding SETUP requests per RTSP session");
 911 +module_param(setup_timeout, int, 0400);
 912 +MODULE_PARM_DESC(setup_timeout, "timeout on for unestablished data channels");
 913 +
 914 +static char *rtsp_buffer;
 915 +static DEFINE_SPINLOCK(rtsp_buffer_lock);
 916 +
 917 +static struct nf_conntrack_expect_policy rtsp_exp_policy;
 918 +
 919 +unsigned int (*nf_nat_rtsp_hook)(struct sk_buff *skb,
 920 +                                enum ip_conntrack_info ctinfo,
 921 +                                unsigned int matchoff, unsigned int matchlen,struct ip_ct_rtsp_expect* prtspexp,
 922 +                                struct nf_conntrack_expect *exp);
 923 +void (*nf_nat_rtsp_hook_expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
 924 +
 925 +EXPORT_SYMBOL_GPL(nf_nat_rtsp_hook);
 926 +
 927 +/*
 928 + * Max mappings we will allow for one RTSP connection (for RTP, the number
 929 + * of allocated ports is twice this value).  Note that SMIL burns a lot of
 930 + * ports so keep this reasonably high.  If this is too low, you will see a
 931 + * lot of "no free client map entries" messages.
 932 + */
 933 +#define MAX_PORT_MAPS 16
 934 +
 935 +/*** default port list was here in the masq code: 554, 3030, 4040 ***/
 936 +
 937 +#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
 938 +
 939 +/*
 940 + * Parse an RTSP packet.
 941 + *
 942 + * Returns zero if parsing failed.
 943 + *
 944 + * Parameters:
 945 + *  IN      ptcp        tcp data pointer
 946 + *  IN      tcplen      tcp data len
 947 + *  IN/OUT  ptcpoff     points to current tcp offset
 948 + *  OUT     phdrsoff    set to offset of rtsp headers
 949 + *  OUT     phdrslen    set to length of rtsp headers
 950 + *  OUT     pcseqoff    set to offset of CSeq header
 951 + *  OUT     pcseqlen    set to length of CSeq header
 952 + */
 953 +static int
 954 +rtsp_parse_message(char* ptcp, uint tcplen, uint* ptcpoff,
 955 +                   uint* phdrsoff, uint* phdrslen,
 956 +                   uint* pcseqoff, uint* pcseqlen,
 957 +                   uint* transoff, uint* translen)
 958 +{
 959 +       uint    entitylen = 0;
 960 +       uint    lineoff;
 961 +       uint    linelen;
 962 +
 963 +       if (!nf_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
 964 +               return 0;
 965 +
 966 +       *phdrsoff = *ptcpoff;
 967 +       while (nf_mime_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen)) {
 968 +               if (linelen == 0) {
 969 +                       if (entitylen > 0)
 970 +                               *ptcpoff += min(entitylen, tcplen - *ptcpoff);
 971 +                       break;
 972 +               }
 973 +               if (lineoff+linelen > tcplen) {
 974 +                       pr_info("!! overrun !!\n");
 975 +                       break;
 976 +               }
 977 +
 978 +               if (nf_strncasecmp(ptcp+lineoff, "CSeq:", 5) == 0) {
 979 +                       *pcseqoff = lineoff;
 980 +                       *pcseqlen = linelen;
 981 +               }
 982 +
 983 +               if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0) {
 984 +                       *transoff = lineoff;
 985 +                       *translen = linelen;
 986 +               }
 987 +
 988 +               if (nf_strncasecmp(ptcp+lineoff, "Content-Length:", 15) == 0) {
 989 +                       uint off = lineoff+15;
 990 +                       SKIP_WSPACE(ptcp+lineoff, linelen, off);
 991 +                       nf_strtou32(ptcp+off, &entitylen);
 992 +               }
 993 +       }
 994 +       *phdrslen = (*ptcpoff) - (*phdrsoff);
 995 +
 996 +       return 1;
 997 +}
 998 +
 999 +/*
1000 + * Find lo/hi client ports (if any) in transport header
1001 + * In:
1002 + *   ptcp, tcplen = packet
1003 + *   tranoff, tranlen = buffer to search
1004 + *
1005 + * Out:
1006 + *   pport_lo, pport_hi = lo/hi ports (host endian)
1007 + *
1008 + * Returns nonzero if any client ports found
1009 + *
1010 + * Note: it is valid (and expected) for the client to request multiple
1011 + * transports, so we need to parse the entire line.
1012 + */
1013 +static int
1014 +rtsp_parse_transport(char* ptran, uint tranlen,
1015 +                     struct ip_ct_rtsp_expect* prtspexp)
1016 +{
1017 +       int     rc = 0;
1018 +       uint    off = 0;
1019 +
1020 +       if (tranlen < 10 || !iseol(ptran[tranlen-1]) ||
1021 +           nf_strncasecmp(ptran, "Transport:", 10) != 0) {
1022 +               pr_info("sanity check failed\n");
1023 +               return 0;
1024 +       }
1025 +
1026 +       pr_debug("tran='%.*s'\n", (int)tranlen, ptran);
1027 +       off += 10;
1028 +       SKIP_WSPACE(ptran, tranlen, off);
1029 +
1030 +       /* Transport: tran;field;field=val,tran;field;field=val,... */
1031 +       while (off < tranlen) {
1032 +               const char* pparamend;
1033 +               uint        nextparamoff;
1034 +
1035 +               pparamend = memchr(ptran+off, ',', tranlen-off);
1036 +               pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
1037 +               nextparamoff = pparamend-ptran;
1038 +
1039 +               while (off < nextparamoff) {
1040 +                       const char* pfieldend;
1041 +                       uint        nextfieldoff;
1042 +
1043 +                       pfieldend = memchr(ptran+off, ';', nextparamoff-off);
1044 +                       nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
1045 +
1046 +                       if (strncmp(ptran+off, "client_port=", 12) == 0) {
1047 +                               u_int16_t   port;
1048 +                               uint        numlen;
1049 +
1050 +                               off += 12;
1051 +                               numlen = nf_strtou16(ptran+off, &port);
1052 +                               off += numlen;
1053 +                               if (prtspexp->loport != 0 && prtspexp->loport != port)
1054 +                                       pr_debug("multiple ports found, port %hu ignored\n", port);
1055 +                               else {
1056 +                                       pr_debug("lo port found : %hu\n", port);
1057 +                                       prtspexp->loport = prtspexp->hiport = port;
1058 +                                       if (ptran[off] == '-') {
1059 +                                               off++;
1060 +                                               numlen = nf_strtou16(ptran+off, &port);
1061 +                                               off += numlen;
1062 +                                               prtspexp->pbtype = pb_range;
1063 +                                               prtspexp->hiport = port;
1064 +
1065 +                                               // If we have a range, assume rtp:
1066 +                                               // loport must be even, hiport must be loport+1
1067 +                                               if ((prtspexp->loport & 0x0001) != 0 ||
1068 +                                                   prtspexp->hiport != prtspexp->loport+1) {
1069 +                                                       pr_debug("incorrect range: %hu-%hu, correcting\n",
1070 +                                                              prtspexp->loport, prtspexp->hiport);
1071 +                                                       prtspexp->loport &= 0xfffe;
1072 +                                                       prtspexp->hiport = prtspexp->loport+1;
1073 +                                               }
1074 +                                       } else if (ptran[off] == '/') {
1075 +                                               off++;
1076 +                                               numlen = nf_strtou16(ptran+off, &port);
1077 +                                               off += numlen;
1078 +                                               prtspexp->pbtype = pb_discon;
1079 +                                               prtspexp->hiport = port;
1080 +                                       }
1081 +                                       rc = 1;
1082 +                               }
1083 +                       }
1084 +
1085 +                       /*
1086 +                        * Note we don't look for the destination parameter here.
1087 +                        * If we are using NAT, the NAT module will handle it.  If not,
1088 +                        * and the client is sending packets elsewhere, the expectation
1089 +                        * will quietly time out.
1090 +                        */
1091 +
1092 +                       off = nextfieldoff;
1093 +               }
1094 +
1095 +               off = nextparamoff;
1096 +       }
1097 +
1098 +       return rc;
1099 +}
1100 +
1101 +void expected(struct nf_conn *ct, struct nf_conntrack_expect *exp)
1102 +{
1103 +               typeof(nf_nat_rtsp_hook_expectfn) nf_nat_rtsp_expectfn;
1104 +               nf_nat_rtsp_expectfn = rcu_dereference(nf_nat_rtsp_hook_expectfn);
1105 +    if(nf_nat_rtsp_expectfn && ct->master->status & IPS_NAT_MASK) {
1106 +        nf_nat_rtsp_expectfn(ct,exp);
1107 +    }
1108 +}
1109 +
1110 +/*** conntrack functions ***/
1111 +
1112 +/* outbound packet: client->server */
1113 +
1114 +static inline int
1115 +help_out(struct sk_buff *skb, unsigned char *rb_ptr, unsigned int datalen,
1116 +                struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1117 +{
1118 +       struct ip_ct_rtsp_expect expinfo;
1119 +
1120 +       int dir = CTINFO2DIR(ctinfo);   /* = IP_CT_DIR_ORIGINAL */
1121 +       //struct  tcphdr* tcph = (void*)iph + iph->ihl * 4;
1122 +       //uint    tcplen = pktlen - iph->ihl * 4;
1123 +       char*   pdata = rb_ptr;
1124 +       //uint    datalen = tcplen - tcph->doff * 4;
1125 +       uint    dataoff = 0;
1126 +       int ret = NF_ACCEPT;
1127 +
1128 +       struct nf_conntrack_expect *exp;
1129 +
1130 +       __be16 be_loport;
1131 +
1132 +       typeof(nf_nat_rtsp_hook) nf_nat_rtsp;
1133 +
1134 +       memset(&expinfo, 0, sizeof(expinfo));
1135 +
1136 +       while (dataoff < datalen) {
1137 +               uint    cmdoff = dataoff;
1138 +               uint    hdrsoff = 0;
1139 +               uint    hdrslen = 0;
1140 +               uint    cseqoff = 0;
1141 +               uint    cseqlen = 0;
1142 +               uint    transoff = 0;
1143 +               uint    translen = 0;
1144 +               uint    off;
1145 +
1146 +               if (!rtsp_parse_message(pdata, datalen, &dataoff,
1147 +                                       &hdrsoff, &hdrslen,
1148 +                                       &cseqoff, &cseqlen,
1149 +                                       &transoff, &translen))
1150 +                       break;      /* not a valid message */
1151 +
1152 +               if (strncmp(pdata+cmdoff, "SETUP ", 6) != 0)
1153 +                       continue;   /* not a SETUP message */
1154 +               pr_debug("found a setup message\n");
1155 +
1156 +               off = 0;
1157 +               if(translen) {
1158 +                       rtsp_parse_transport(pdata+transoff, translen, &expinfo);
1159 +               }
1160 +
1161 +               if (expinfo.loport == 0) {
1162 +                       pr_debug("no udp transports found\n");
1163 +                       continue;   /* no udp transports found */
1164 +               }
1165 +
1166 +               pr_debug("udp transport found, ports=(%d,%hu,%hu)\n",
1167 +                      (int)expinfo.pbtype, expinfo.loport, expinfo.hiport);
1168 +
1169 +               exp = nf_ct_expect_alloc(ct);
1170 +               if (!exp) {
1171 +                       ret = NF_DROP;
1172 +                       goto out;
1173 +               }
1174 +
1175 +               be_loport = htons(expinfo.loport);
1176 +
1177 +               nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1178 +                       &ct->tuplehash[!dir].tuple.src.u3, &ct->tuplehash[!dir].tuple.dst.u3,
1179 +                       IPPROTO_UDP, NULL, &be_loport);
1180 +
1181 +               exp->master = ct;
1182 +
1183 +               exp->expectfn = expected;
1184 +               exp->flags = 0;
1185 +
1186 +               if (expinfo.pbtype == pb_range) {
1187 +                       pr_debug("Changing expectation mask to handle multiple ports\n");
1188 +                       //exp->mask.dst.u.udp.port  = 0xfffe;
1189 +               }
1190 +
1191 +               pr_debug("expect_related %u.%u.%u.%u:%u-%u.%u.%u.%u:%u\n",
1192 +                      NIPQUAD(exp->tuple.src.u3.ip),
1193 +                      ntohs(exp->tuple.src.u.udp.port),
1194 +                      NIPQUAD(exp->tuple.dst.u3.ip),
1195 +                      ntohs(exp->tuple.dst.u.udp.port));
1196 +
1197 +               nf_nat_rtsp = rcu_dereference(nf_nat_rtsp_hook);
1198 +               if (nf_nat_rtsp && ct->status & IPS_NAT_MASK)
1199 +                       /* pass the request off to the nat helper */
1200 +                       ret = nf_nat_rtsp(skb, ctinfo, hdrsoff, hdrslen, &expinfo, exp);
1201 +               else if (nf_ct_expect_related(exp) != 0) {
1202 +                       pr_info("nf_conntrack_expect_related failed\n");
1203 +                       ret  = NF_DROP;
1204 +               }
1205 +               nf_ct_expect_put(exp);
1206 +               goto out;
1207 +       }
1208 +out:
1209 +
1210 +       return ret;
1211 +}
1212 +
1213 +
1214 +static inline int
1215 +help_in(struct sk_buff *skb, size_t pktlen,
1216 + struct nf_conn* ct, enum ip_conntrack_info ctinfo)
1217 +{
1218 + return NF_ACCEPT;
1219 +}
1220 +
1221 +static int help(struct sk_buff *skb, unsigned int protoff,
1222 +               struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1223 +{
1224 +       struct tcphdr _tcph, *th;
1225 +       unsigned int dataoff, datalen;
1226 +       char *rb_ptr;
1227 +       int ret = NF_DROP;
1228 +
1229 +       /* Until there's been traffic both ways, don't look in packets. */
1230 +       if (ctinfo != IP_CT_ESTABLISHED &&
1231 +           ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
1232 +               pr_debug("conntrackinfo = %u\n", ctinfo);
1233 +               return NF_ACCEPT;
1234 +       }
1235 +
1236 +       /* Not whole TCP header? */
1237 +       th = skb_header_pointer(skb,protoff, sizeof(_tcph), &_tcph);
1238 +
1239 +       if (!th)
1240 +               return NF_ACCEPT;
1241 +
1242 +       /* No data ? */
1243 +       dataoff = protoff + th->doff*4;
1244 +       datalen = skb->len - dataoff;
1245 +       if (dataoff >= skb->len)
1246 +               return NF_ACCEPT;
1247 +
1248 +       spin_lock_bh(&rtsp_buffer_lock);
1249 +       rb_ptr = skb_header_pointer(skb, dataoff,
1250 +                                   skb->len - dataoff, rtsp_buffer);
1251 +       BUG_ON(rb_ptr == NULL);
1252 +
1253 +#if 0
1254 +       /* Checksum invalid?  Ignore. */
1255 +       /* FIXME: Source route IP option packets --RR */
1256 +       if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
1257 +                        csum_partial((char*)tcph, tcplen, 0)))
1258 +       {
1259 +               DEBUGP("bad csum: %p %u %u.%u.%u.%u %u.%u.%u.%u\n",
1260 +                      tcph, tcplen, NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
1261 +               return NF_ACCEPT;
1262 +       }
1263 +#endif
1264 +
1265 +       switch (CTINFO2DIR(ctinfo)) {
1266 +       case IP_CT_DIR_ORIGINAL:
1267 +               ret = help_out(skb, rb_ptr, datalen, ct, ctinfo);
1268 +               break;
1269 +       case IP_CT_DIR_REPLY:
1270 +               pr_debug("IP_CT_DIR_REPLY\n");
1271 +               /* inbound packet: server->client */
1272 +               ret = NF_ACCEPT;
1273 +               break;
1274 +       }
1275 +
1276 +       spin_unlock_bh(&rtsp_buffer_lock);
1277 +
1278 +       return ret;
1279 +}
1280 +
1281 +static struct nf_conntrack_helper rtsp_helpers[MAX_PORTS];
1282 +static char rtsp_names[MAX_PORTS][10];
1283 +
1284 +/* This function is intentionally _NOT_ defined as __exit */
1285 +static void
1286 +fini(void)
1287 +{
1288 +       int i;
1289 +       for (i = 0; i < num_ports; i++) {
1290 +               pr_debug("unregistering port %d\n", ports[i]);
1291 +               nf_conntrack_helper_unregister(&rtsp_helpers[i]);
1292 +       }
1293 +       kfree(rtsp_buffer);
1294 +}
1295 +
1296 +static int __init
1297 +init(void)
1298 +{
1299 +       int i, ret;
1300 +       struct nf_conntrack_helper *hlpr;
1301 +       char *tmpname;
1302 +
1303 +       printk("nf_conntrack_rtsp v" IP_NF_RTSP_VERSION " loading\n");
1304 +
1305 +       if (max_outstanding < 1) {
1306 +               printk("nf_conntrack_rtsp: max_outstanding must be a positive integer\n");
1307 +               return -EBUSY;
1308 +       }
1309 +       if (setup_timeout < 0) {
1310 +               printk("nf_conntrack_rtsp: setup_timeout must be a positive integer\n");
1311 +               return -EBUSY;
1312 +       }
1313 +
1314 +  rtsp_exp_policy.max_expected = max_outstanding;
1315 +  rtsp_exp_policy.timeout = setup_timeout;
1316 +
1317 +       rtsp_buffer = kmalloc(65536, GFP_KERNEL);
1318 +       if (!rtsp_buffer)
1319 +               return -ENOMEM;
1320 +
1321 +       /* If no port given, default to standard rtsp port */
1322 +       if (ports[0] == 0) {
1323 +               ports[0] = RTSP_PORT;
1324 +       }
1325 +
1326 +       for (i = 0; (i < MAX_PORTS) && ports[i]; i++) {
1327 +               hlpr = &rtsp_helpers[i];
1328 +               memset(hlpr, 0, sizeof(struct nf_conntrack_helper));
1329 +               hlpr->tuple.src.l3num = AF_INET;
1330 +               hlpr->tuple.src.u.tcp.port = htons(ports[i]);
1331 +               hlpr->tuple.dst.protonum = IPPROTO_TCP;
1332 +               //hlpr->mask.src.u.tcp.port = 0xFFFF;
1333 +               //hlpr->mask.dst.protonum = 0xFF;
1334 +               hlpr->expect_policy = &rtsp_exp_policy;
1335 +               hlpr->me = THIS_MODULE;
1336 +               hlpr->help = help;
1337 +
1338 +               tmpname = &rtsp_names[i][0];
1339 +               if (ports[i] == RTSP_PORT) {
1340 +                       sprintf(tmpname, "rtsp");
1341 +               } else {
1342 +                       sprintf(tmpname, "rtsp-%d", i);
1343 +               }
1344 +               hlpr->name = tmpname;
1345 +
1346 +               pr_debug("port #%d: %d\n", i, ports[i]);
1347 +
1348 +               ret = nf_conntrack_helper_register(hlpr);
1349 +
1350 +               if (ret) {
1351 +                       printk("nf_conntrack_rtsp: ERROR registering port %d\n", ports[i]);
1352 +                       fini();
1353 +                       return -EBUSY;
1354 +               }
1355 +               num_ports++;
1356 +       }
1357 +       return 0;
1358 +}
1359 +
1360 +module_init(init);
1361 +module_exit(fini);
1362 +
1363 +EXPORT_SYMBOL(nf_nat_rtsp_hook_expectfn);
1364 +