target/linux/generic-2.6/patches-2.6.24/190-netfilter_rtsp.patch

   1 Index: linux-2.6.24.7/include/linux/netfilter/nf_conntrack_rtsp.h
   2 ===================================================================
   3 --- /dev/null
   4 +++ linux-2.6.24.7/include/linux/netfilter/nf_conntrack_rtsp.h
   5 @@ -0,0 +1,63 @@
   6 +/*
   7 + * RTSP extension for IP connection tracking.
   8 + * (C) 2003 by Tom Marshall <tmarshall at real.com>
   9 + * based on ip_conntrack_irc.h
  10 + *
  11 + *      This program is free software; you can redistribute it and/or
  12 + *      modify it under the terms of the GNU General Public License
  13 + *      as published by the Free Software Foundation; either version
  14 + *      2 of the License, or (at your option) any later version.
  15 + */
  16 +#ifndef _IP_CONNTRACK_RTSP_H
  17 +#define _IP_CONNTRACK_RTSP_H
  18 +
  19 +//#define IP_NF_RTSP_DEBUG 1
  20 +#define IP_NF_RTSP_VERSION "0.6.21"
  21 +
  22 +#ifdef __KERNEL__
  23 +/* port block types */
  24 +typedef enum {
  25 +    pb_single,  /* client_port=x */
  26 +    pb_range,   /* client_port=x-y */
  27 +    pb_discon   /* client_port=x/y (rtspbis) */
  28 +} portblock_t;
  29 +
  30 +/* We record seq number and length of rtsp headers here, all in host order. */
  31 +
  32 +/*
  33 + * This structure is per expected connection.  It is a member of struct
  34 + * ip_conntrack_expect.  The TCP SEQ for the conntrack expect is stored
  35 + * there and we are expected to only store the length of the data which
  36 + * needs replaced.  If a packet contains multiple RTSP messages, we create
  37 + * one expected connection per message.
  38 + *
  39 + * We use these variables to mark the entire header block.  This may seem
  40 + * like overkill, but the nature of RTSP requires it.  A header may appear
  41 + * multiple times in a message.  We must treat two Transport headers the
  42 + * same as one Transport header with two entries.
  43 + */
  44 +struct ip_ct_rtsp_expect
  45 +{
  46 +    u_int32_t   len;        /* length of header block */
  47 +    portblock_t pbtype;     /* Type of port block that was requested */
  48 +    u_int16_t   loport;     /* Port that was requested, low or first */
  49 +    u_int16_t   hiport;     /* Port that was requested, high or second */
  50 +#if 0
  51 +    uint        method;     /* RTSP method */
  52 +    uint        cseq;       /* CSeq from request */
  53 +#endif
  54 +};
  55 +
  56 +extern unsigned int (*nf_nat_rtsp_hook)(struct sk_buff *skb,
  57 +                                enum ip_conntrack_info ctinfo,
  58 +                                unsigned int matchoff, unsigned int matchlen,
  59 +                                struct ip_ct_rtsp_expect *prtspexp,
  60 +                                struct nf_conntrack_expect *exp);
  61 +
  62 +extern void (*nf_nat_rtsp_hook_expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
  63 +
  64 +#define RTSP_PORT   554
  65 +
  66 +#endif /* __KERNEL__ */
  67 +
  68 +#endif /* _IP_CONNTRACK_RTSP_H */
  69 Index: linux-2.6.24.7/include/linux/netfilter_helpers.h
  70 ===================================================================
  71 --- /dev/null
  72 +++ linux-2.6.24.7/include/linux/netfilter_helpers.h
  73 @@ -0,0 +1,133 @@
  74 +/*
  75 + * Helpers for netfiler modules.  This file provides implementations for basic
  76 + * functions such as strncasecmp(), etc.
  77 + *
  78 + * gcc will warn for defined but unused functions, so we only include the
  79 + * functions requested.  The following macros are used:
  80 + *   NF_NEED_STRNCASECMP        nf_strncasecmp()
  81 + *   NF_NEED_STRTOU16           nf_strtou16()
  82 + *   NF_NEED_STRTOU32           nf_strtou32()
  83 + */
  84 +#ifndef _NETFILTER_HELPERS_H
  85 +#define _NETFILTER_HELPERS_H
  86 +
  87 +/* Only include these functions for kernel code. */
  88 +#ifdef __KERNEL__
  89 +
  90 +#include <linux/ctype.h>
  91 +#define iseol(c) ( (c) == '\r' || (c) == '\n' )
  92 +
  93 +/*
  94 + * The standard strncasecmp()
  95 + */
  96 +#ifdef NF_NEED_STRNCASECMP
  97 +static int
  98 +nf_strncasecmp(const char* s1, const char* s2, u_int32_t len)
  99 +{
 100 +    if (s1 == NULL || s2 == NULL)
 101 +    {
 102 +        if (s1 == NULL && s2 == NULL)
 103 +        {
 104 +            return 0;
 105 +        }
 106 +        return (s1 == NULL) ? -1 : 1;
 107 +    }
 108 +    while (len > 0 && tolower(*s1) == tolower(*s2))
 109 +    {
 110 +        len--;
 111 +        s1++;
 112 +        s2++;
 113 +    }
 114 +    return ( (len == 0) ? 0 : (tolower(*s1) - tolower(*s2)) );
 115 +}
 116 +#endif /* NF_NEED_STRNCASECMP */
 117 +
 118 +/*
 119 + * Parse a string containing a 16-bit unsigned integer.
 120 + * Returns the number of chars used, or zero if no number is found.
 121 + */
 122 +#ifdef NF_NEED_STRTOU16
 123 +static int
 124 +nf_strtou16(const char* pbuf, u_int16_t* pval)
 125 +{
 126 +    int n = 0;
 127 +
 128 +    *pval = 0;
 129 +    while (isdigit(pbuf[n]))
 130 +    {
 131 +        *pval = (*pval * 10) + (pbuf[n] - '0');
 132 +        n++;
 133 +    }
 134 +
 135 +    return n;
 136 +}
 137 +#endif /* NF_NEED_STRTOU16 */
 138 +
 139 +/*
 140 + * Parse a string containing a 32-bit unsigned integer.
 141 + * Returns the number of chars used, or zero if no number is found.
 142 + */
 143 +#ifdef NF_NEED_STRTOU32
 144 +static int
 145 +nf_strtou32(const char* pbuf, u_int32_t* pval)
 146 +{
 147 +    int n = 0;
 148 +
 149 +    *pval = 0;
 150 +    while (pbuf[n] >= '0' && pbuf[n] <= '9')
 151 +    {
 152 +        *pval = (*pval * 10) + (pbuf[n] - '0');
 153 +        n++;
 154 +    }
 155 +
 156 +    return n;
 157 +}
 158 +#endif /* NF_NEED_STRTOU32 */
 159 +
 160 +/*
 161 + * Given a buffer and length, advance to the next line and mark the current
 162 + * line.
 163 + */
 164 +#ifdef NF_NEED_NEXTLINE
 165 +static int
 166 +nf_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
 167 +{
 168 +    uint    off = *poff;
 169 +    uint    physlen = 0;
 170 +
 171 +    if (off >= len)
 172 +    {
 173 +        return 0;
 174 +    }
 175 +
 176 +    while (p[off] != '\n')
 177 +    {
 178 +        if (len-off <= 1)
 179 +        {
 180 +            return 0;
 181 +        }
 182 +
 183 +        physlen++;
 184 +        off++;
 185 +    }
 186 +
 187 +    /* if we saw a crlf, physlen needs adjusted */
 188 +    if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
 189 +    {
 190 +        physlen--;
 191 +    }
 192 +
 193 +    /* advance past the newline */
 194 +    off++;
 195 +
 196 +    *plineoff = *poff;
 197 +    *plinelen = physlen;
 198 +    *poff = off;
 199 +
 200 +    return 1;
 201 +}
 202 +#endif /* NF_NEED_NEXTLINE */
 203 +
 204 +#endif /* __KERNEL__ */
 205 +
 206 +#endif /* _NETFILTER_HELPERS_H */
 207 Index: linux-2.6.24.7/include/linux/netfilter_mime.h
 208 ===================================================================
 209 --- /dev/null
 210 +++ linux-2.6.24.7/include/linux/netfilter_mime.h
 211 @@ -0,0 +1,89 @@
 212 +/*
 213 + * MIME functions for netfilter modules.  This file provides implementations
 214 + * for basic MIME parsing.  MIME headers are used in many protocols, such as
 215 + * HTTP, RTSP, SIP, etc.
 216 + *
 217 + * gcc will warn for defined but unused functions, so we only include the
 218 + * functions requested.  The following macros are used:
 219 + *   NF_NEED_MIME_NEXTLINE      nf_mime_nextline()
 220 + */
 221 +#ifndef _NETFILTER_MIME_H
 222 +#define _NETFILTER_MIME_H
 223 +
 224 +/* Only include these functions for kernel code. */
 225 +#ifdef __KERNEL__
 226 +
 227 +#include <linux/ctype.h>
 228 +
 229 +/*
 230 + * Given a buffer and length, advance to the next line and mark the current
 231 + * line.  If the current line is empty, *plinelen will be set to zero.  If
 232 + * not, it will be set to the actual line length (including CRLF).
 233 + *
 234 + * 'line' in this context means logical line (includes LWS continuations).
 235 + * Returns 1 on success, 0 on failure.
 236 + */
 237 +#ifdef NF_NEED_MIME_NEXTLINE
 238 +static int
 239 +nf_mime_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
 240 +{
 241 +    uint    off = *poff;
 242 +    uint    physlen = 0;
 243 +    int     is_first_line = 1;
 244 +
 245 +    if (off >= len)
 246 +    {
 247 +        return 0;
 248 +    }
 249 +
 250 +    do
 251 +    {
 252 +        while (p[off] != '\n')
 253 +        {
 254 +            if (len-off <= 1)
 255 +            {
 256 +                return 0;
 257 +            }
 258 +
 259 +            physlen++;
 260 +            off++;
 261 +        }
 262 +
 263 +        /* if we saw a crlf, physlen needs adjusted */
 264 +        if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
 265 +        {
 266 +            physlen--;
 267 +        }
 268 +
 269 +        /* advance past the newline */
 270 +        off++;
 271 +
 272 +        /* check for an empty line */
 273 +        if (physlen == 0)
 274 +        {
 275 +            break;
 276 +        }
 277 +
 278 +        /* check for colon on the first physical line */
 279 +        if (is_first_line)
 280 +        {
 281 +            is_first_line = 0;
 282 +            if (memchr(p+(*poff), ':', physlen) == NULL)
 283 +            {
 284 +                return 0;
 285 +            }
 286 +        }
 287 +    }
 288 +    while (p[off] == ' ' || p[off] == '\t');
 289 +
 290 +    *plineoff = *poff;
 291 +    *plinelen = (physlen == 0) ? 0 : (off - *poff);
 292 +    *poff = off;
 293 +
 294 +    return 1;
 295 +}
 296 +#endif /* NF_NEED_MIME_NEXTLINE */
 297 +
 298 +#endif /* __KERNEL__ */
 299 +
 300 +#endif /* _NETFILTER_MIME_H */
 301 Index: linux-2.6.24.7/net/ipv4/netfilter/Makefile
 302 ===================================================================
 303 --- linux-2.6.24.7.orig/net/ipv4/netfilter/Makefile
 304 +++ linux-2.6.24.7/net/ipv4/netfilter/Makefile
 305 @@ -23,6 +23,7 @@ obj-$(CONFIG_NF_NAT_AMANDA) += nf_nat_am
 306  obj-$(CONFIG_NF_NAT_FTP) += nf_nat_ftp.o
 307  obj-$(CONFIG_NF_NAT_H323) += nf_nat_h323.o
 308  obj-$(CONFIG_NF_NAT_IRC) += nf_nat_irc.o
 309 +obj-$(CONFIG_NF_NAT_RTSP) += nf_nat_rtsp.o
 310  obj-$(CONFIG_NF_NAT_PPTP) += nf_nat_pptp.o
 311  obj-$(CONFIG_NF_NAT_SIP) += nf_nat_sip.o
 312  obj-$(CONFIG_NF_NAT_SNMP_BASIC) += nf_nat_snmp_basic.o
 313 Index: linux-2.6.24.7/net/netfilter/Kconfig
 314 ===================================================================
 315 --- linux-2.6.24.7.orig/net/netfilter/Kconfig
 316 +++ linux-2.6.24.7/net/netfilter/Kconfig
 317 @@ -249,6 +249,16 @@ config NF_CONNTRACK_TFTP
 318
 319           To compile it as a module, choose M here.  If unsure, say N.
 320
 321 +config NF_CONNTRACK_RTSP
 322 +       tristate "RTSP protocol support"
 323 +       depends on NF_CONNTRACK
 324 +       help
 325 +               Support the RTSP protocol.  This allows UDP transports to be setup
 326 +               properly, including RTP and RDT.
 327 +
 328 +               If you want to compile it as a module, say 'M' here and read
 329 +               Documentation/modules.txt.  If unsure, say 'Y'.
 330 +
 331  config NF_CT_NETLINK
 332         tristate 'Connection tracking netlink interface (EXPERIMENTAL)'
 333         depends on EXPERIMENTAL && NF_CONNTRACK && NETFILTER_NETLINK
 334 Index: linux-2.6.24.7/net/netfilter/Makefile
 335 ===================================================================
 336 --- linux-2.6.24.7.orig/net/netfilter/Makefile
 337 +++ linux-2.6.24.7/net/netfilter/Makefile
 338 @@ -33,6 +33,7 @@ obj-$(CONFIG_NF_CONNTRACK_PPTP) += nf_co
 339  obj-$(CONFIG_NF_CONNTRACK_SANE) += nf_conntrack_sane.o
 340  obj-$(CONFIG_NF_CONNTRACK_SIP) += nf_conntrack_sip.o
 341  obj-$(CONFIG_NF_CONNTRACK_TFTP) += nf_conntrack_tftp.o
 342 +obj-$(CONFIG_NF_CONNTRACK_RTSP) += nf_conntrack_rtsp.o
 343
 344  # generic X tables
 345  obj-$(CONFIG_NETFILTER_XTABLES) += x_tables.o xt_tcpudp.o
 346 Index: linux-2.6.24.7/net/ipv4/netfilter/Kconfig
 347 ===================================================================
 348 --- linux-2.6.24.7.orig/net/ipv4/netfilter/Kconfig
 349 +++ linux-2.6.24.7/net/ipv4/netfilter/Kconfig
 350 @@ -296,6 +296,11 @@ config NF_NAT_IRC
 351         depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
 352         default NF_NAT && NF_CONNTRACK_IRC
 353
 354 +config NF_NAT_RTSP
 355 +       tristate
 356 +       depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
 357 +       default NF_NAT && NF_CONNTRACK_RTSP
 358 +
 359  config NF_NAT_TFTP
 360         tristate
 361         depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
 362 Index: linux-2.6.24.7/net/netfilter/nf_conntrack_rtsp.c
 363 ===================================================================
 364 --- /dev/null
 365 +++ linux-2.6.24.7/net/netfilter/nf_conntrack_rtsp.c
 366 @@ -0,0 +1,513 @@
 367 +/*
 368 + * RTSP extension for IP connection tracking
 369 + * (C) 2003 by Tom Marshall <tmarshall at real.com>
 370 + * based on ip_conntrack_irc.c
 371 + *
 372 + *      This program is free software; you can redistribute it and/or
 373 + *      modify it under the terms of the GNU General Public License
 374 + *      as published by the Free Software Foundation; either version
 375 + *      2 of the License, or (at your option) any later version.
 376 + *
 377 + * Module load syntax:
 378 + *   insmod nf_conntrack_rtsp.o ports=port1,port2,...port<MAX_PORTS>
 379 + *                              max_outstanding=n setup_timeout=secs
 380 + *
 381 + * If no ports are specified, the default will be port 554.
 382 + *
 383 + * With max_outstanding you can define the maximum number of not yet
 384 + * answered SETUP requests per RTSP session (default 8).
 385 + * With setup_timeout you can specify how long the system waits for
 386 + * an expected data channel (default 300 seconds).
 387 + *
 388 + * 2005-02-13: Harald Welte <laforge at netfilter.org>
 389 + *     - port to 2.6
 390 + *     - update to recent post-2.6.11 api changes
 391 + * 2006-09-14: Steven Van Acker <deepstar at singularity.be>
 392 + *      - removed calls to NAT code from conntrack helper: NAT no longer needed to use rtsp-conntrack
 393 + * 2007-04-18: Michael Guntsche <mike at it-loops.com>
 394 + *                     - Port to new NF API
 395 + */
 396 +
 397 +#include <linux/module.h>
 398 +#include <linux/netfilter.h>
 399 +#include <linux/ip.h>
 400 +#include <linux/inet.h>
 401 +#include <net/tcp.h>
 402 +
 403 +#include <net/netfilter/nf_conntrack.h>
 404 +#include <net/netfilter/nf_conntrack_expect.h>
 405 +#include <net/netfilter/nf_conntrack_helper.h>
 406 +#include <linux/netfilter/nf_conntrack_rtsp.h>
 407 +
 408 +#define NF_NEED_STRNCASECMP
 409 +#define NF_NEED_STRTOU16
 410 +#define NF_NEED_STRTOU32
 411 +#define NF_NEED_NEXTLINE
 412 +#include <linux/netfilter_helpers.h>
 413 +#define NF_NEED_MIME_NEXTLINE
 414 +#include <linux/netfilter_mime.h>
 415 +
 416 +#include <linux/ctype.h>
 417 +#define MAX_SIMUL_SETUP 8 /* XXX: use max_outstanding */
 418 +#define INFOP(fmt, args...) printk(KERN_INFO "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
 419 +#if 0
 420 +#define DEBUGP(fmt, args...) printk(KERN_DEBUG "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
 421 +#else
 422 +#define DEBUGP(fmt, args...)
 423 +#endif
 424 +
 425 +#define MAX_PORTS 8
 426 +static int ports[MAX_PORTS];
 427 +static int num_ports = 0;
 428 +static int max_outstanding = 8;
 429 +static unsigned int setup_timeout = 300;
 430 +
 431 +MODULE_AUTHOR("Tom Marshall <tmarshall at real.com>");
 432 +MODULE_DESCRIPTION("RTSP connection tracking module");
 433 +MODULE_LICENSE("GPL");
 434 +module_param_array(ports, int, &num_ports, 0400);
 435 +MODULE_PARM_DESC(ports, "port numbers of RTSP servers");
 436 +module_param(max_outstanding, int, 0400);
 437 +MODULE_PARM_DESC(max_outstanding, "max number of outstanding SETUP requests per RTSP session");
 438 +module_param(setup_timeout, int, 0400);
 439 +MODULE_PARM_DESC(setup_timeout, "timeout on for unestablished data channels");
 440 +
 441 +static char *rtsp_buffer;
 442 +static DEFINE_SPINLOCK(rtsp_buffer_lock);
 443 +
 444 +unsigned int (*nf_nat_rtsp_hook)(struct sk_buff *skb,
 445 +                                enum ip_conntrack_info ctinfo,
 446 +                                unsigned int matchoff, unsigned int matchlen,struct ip_ct_rtsp_expect* prtspexp,
 447 +                                struct nf_conntrack_expect *exp);
 448 +void (*nf_nat_rtsp_hook_expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
 449 +
 450 +EXPORT_SYMBOL_GPL(nf_nat_rtsp_hook);
 451 +
 452 +/*
 453 + * Max mappings we will allow for one RTSP connection (for RTP, the number
 454 + * of allocated ports is twice this value).  Note that SMIL burns a lot of
 455 + * ports so keep this reasonably high.  If this is too low, you will see a
 456 + * lot of "no free client map entries" messages.
 457 + */
 458 +#define MAX_PORT_MAPS 16
 459 +
 460 +/*** default port list was here in the masq code: 554, 3030, 4040 ***/
 461 +
 462 +#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
 463 +
 464 +/*
 465 + * Parse an RTSP packet.
 466 + *
 467 + * Returns zero if parsing failed.
 468 + *
 469 + * Parameters:
 470 + *  IN      ptcp        tcp data pointer
 471 + *  IN      tcplen      tcp data len
 472 + *  IN/OUT  ptcpoff     points to current tcp offset
 473 + *  OUT     phdrsoff    set to offset of rtsp headers
 474 + *  OUT     phdrslen    set to length of rtsp headers
 475 + *  OUT     pcseqoff    set to offset of CSeq header
 476 + *  OUT     pcseqlen    set to length of CSeq header
 477 + */
 478 +static int
 479 +rtsp_parse_message(char* ptcp, uint tcplen, uint* ptcpoff,
 480 +                   uint* phdrsoff, uint* phdrslen,
 481 +                   uint* pcseqoff, uint* pcseqlen,
 482 +                   uint* transoff, uint* translen)
 483 +{
 484 +       uint    entitylen = 0;
 485 +       uint    lineoff;
 486 +       uint    linelen;
 487 +
 488 +       if (!nf_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
 489 +               return 0;
 490 +
 491 +       *phdrsoff = *ptcpoff;
 492 +       while (nf_mime_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen)) {
 493 +               if (linelen == 0) {
 494 +                       if (entitylen > 0)
 495 +                               *ptcpoff += min(entitylen, tcplen - *ptcpoff);
 496 +                       break;
 497 +               }
 498 +               if (lineoff+linelen > tcplen) {
 499 +                       INFOP("!! overrun !!\n");
 500 +                       break;
 501 +               }
 502 +
 503 +               if (nf_strncasecmp(ptcp+lineoff, "CSeq:", 5) == 0) {
 504 +                       *pcseqoff = lineoff;
 505 +                       *pcseqlen = linelen;
 506 +               }
 507 +
 508 +               if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0) {
 509 +                       *transoff = lineoff;
 510 +                       *translen = linelen;
 511 +               }
 512 +
 513 +               if (nf_strncasecmp(ptcp+lineoff, "Content-Length:", 15) == 0) {
 514 +                       uint off = lineoff+15;
 515 +                       SKIP_WSPACE(ptcp+lineoff, linelen, off);
 516 +                       nf_strtou32(ptcp+off, &entitylen);
 517 +               }
 518 +       }
 519 +       *phdrslen = (*ptcpoff) - (*phdrsoff);
 520 +
 521 +       return 1;
 522 +}
 523 +
 524 +/*
 525 + * Find lo/hi client ports (if any) in transport header
 526 + * In:
 527 + *   ptcp, tcplen = packet
 528 + *   tranoff, tranlen = buffer to search
 529 + *
 530 + * Out:
 531 + *   pport_lo, pport_hi = lo/hi ports (host endian)
 532 + *
 533 + * Returns nonzero if any client ports found
 534 + *
 535 + * Note: it is valid (and expected) for the client to request multiple
 536 + * transports, so we need to parse the entire line.
 537 + */
 538 +static int
 539 +rtsp_parse_transport(char* ptran, uint tranlen,
 540 +                     struct ip_ct_rtsp_expect* prtspexp)
 541 +{
 542 +       int     rc = 0;
 543 +       uint    off = 0;
 544 +
 545 +       if (tranlen < 10 || !iseol(ptran[tranlen-1]) ||
 546 +           nf_strncasecmp(ptran, "Transport:", 10) != 0) {
 547 +               INFOP("sanity check failed\n");
 548 +               return 0;
 549 +       }
 550 +
 551 +       DEBUGP("tran='%.*s'\n", (int)tranlen, ptran);
 552 +       off += 10;
 553 +       SKIP_WSPACE(ptran, tranlen, off);
 554 +
 555 +       /* Transport: tran;field;field=val,tran;field;field=val,... */
 556 +       while (off < tranlen) {
 557 +               const char* pparamend;
 558 +               uint        nextparamoff;
 559 +
 560 +               pparamend = memchr(ptran+off, ',', tranlen-off);
 561 +               pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
 562 +               nextparamoff = pparamend-ptran;
 563 +
 564 +               while (off < nextparamoff) {
 565 +                       const char* pfieldend;
 566 +                       uint        nextfieldoff;
 567 +
 568 +                       pfieldend = memchr(ptran+off, ';', nextparamoff-off);
 569 +                       nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
 570 +
 571 +                       if (strncmp(ptran+off, "client_port=", 12) == 0) {
 572 +                               u_int16_t   port;
 573 +                               uint        numlen;
 574 +
 575 +                               off += 12;
 576 +                               numlen = nf_strtou16(ptran+off, &port);
 577 +                               off += numlen;
 578 +                               if (prtspexp->loport != 0 && prtspexp->loport != port)
 579 +                                       DEBUGP("multiple ports found, port %hu ignored\n", port);
 580 +                               else {
 581 +                                       DEBUGP("lo port found : %hu\n", port);
 582 +                                       prtspexp->loport = prtspexp->hiport = port;
 583 +                                       if (ptran[off] == '-') {
 584 +                                               off++;
 585 +                                               numlen = nf_strtou16(ptran+off, &port);
 586 +                                               off += numlen;
 587 +                                               prtspexp->pbtype = pb_range;
 588 +                                               prtspexp->hiport = port;
 589 +
 590 +                                               // If we have a range, assume rtp:
 591 +                                               // loport must be even, hiport must be loport+1
 592 +                                               if ((prtspexp->loport & 0x0001) != 0 ||
 593 +                                                   prtspexp->hiport != prtspexp->loport+1) {
 594 +                                                       DEBUGP("incorrect range: %hu-%hu, correcting\n",
 595 +                                                              prtspexp->loport, prtspexp->hiport);
 596 +                                                       prtspexp->loport &= 0xfffe;
 597 +                                                       prtspexp->hiport = prtspexp->loport+1;
 598 +                                               }
 599 +                                       } else if (ptran[off] == '/') {
 600 +                                               off++;
 601 +                                               numlen = nf_strtou16(ptran+off, &port);
 602 +                                               off += numlen;
 603 +                                               prtspexp->pbtype = pb_discon;
 604 +                                               prtspexp->hiport = port;
 605 +                                       }
 606 +                                       rc = 1;
 607 +                               }
 608 +                       }
 609 +
 610 +                       /*
 611 +                        * Note we don't look for the destination parameter here.
 612 +                        * If we are using NAT, the NAT module will handle it.  If not,
 613 +                        * and the client is sending packets elsewhere, the expectation
 614 +                        * will quietly time out.
 615 +                        */
 616 +
 617 +                       off = nextfieldoff;
 618 +               }
 619 +
 620 +               off = nextparamoff;
 621 +       }
 622 +
 623 +       return rc;
 624 +}
 625 +
 626 +void expected(struct nf_conn *ct, struct nf_conntrack_expect *exp)
 627 +{
 628 +    if(nf_nat_rtsp_hook_expectfn) {
 629 +        nf_nat_rtsp_hook_expectfn(ct,exp);
 630 +    }
 631 +}
 632 +
 633 +/*** conntrack functions ***/
 634 +
 635 +/* outbound packet: client->server */
 636 +
 637 +static inline int
 638 +help_out(struct sk_buff *skb, unsigned char *rb_ptr, unsigned int datalen,
 639 +                struct nf_conn *ct, enum ip_conntrack_info ctinfo)
 640 +{
 641 +       struct ip_ct_rtsp_expect expinfo;
 642 +
 643 +       int dir = CTINFO2DIR(ctinfo);   /* = IP_CT_DIR_ORIGINAL */
 644 +       //struct  tcphdr* tcph = (void*)iph + iph->ihl * 4;
 645 +       //uint    tcplen = pktlen - iph->ihl * 4;
 646 +       char*   pdata = rb_ptr;
 647 +       //uint    datalen = tcplen - tcph->doff * 4;
 648 +       uint    dataoff = 0;
 649 +       int ret = NF_ACCEPT;
 650 +
 651 +       struct nf_conntrack_expect *exp;
 652 +
 653 +       __be16 be_loport;
 654 +
 655 +       memset(&expinfo, 0, sizeof(expinfo));
 656 +
 657 +       while (dataoff < datalen) {
 658 +               uint    cmdoff = dataoff;
 659 +               uint    hdrsoff = 0;
 660 +               uint    hdrslen = 0;
 661 +               uint    cseqoff = 0;
 662 +               uint    cseqlen = 0;
 663 +               uint    transoff = 0;
 664 +               uint    translen = 0;
 665 +               uint    off;
 666 +
 667 +               if (!rtsp_parse_message(pdata, datalen, &dataoff,
 668 +                                       &hdrsoff, &hdrslen,
 669 +                                       &cseqoff, &cseqlen,
 670 +                                       &transoff, &translen))
 671 +                       break;      /* not a valid message */
 672 +
 673 +               if (strncmp(pdata+cmdoff, "SETUP ", 6) != 0)
 674 +                       continue;   /* not a SETUP message */
 675 +               DEBUGP("found a setup message\n");
 676 +
 677 +               off = 0;
 678 +               if(translen) {
 679 +                       rtsp_parse_transport(pdata+transoff, translen, &expinfo);
 680 +               }
 681 +
 682 +               if (expinfo.loport == 0) {
 683 +                       DEBUGP("no udp transports found\n");
 684 +                       continue;   /* no udp transports found */
 685 +               }
 686 +
 687 +               DEBUGP("udp transport found, ports=(%d,%hu,%hu)\n",
 688 +                      (int)expinfo.pbtype, expinfo.loport, expinfo.hiport);
 689 +
 690 +               exp = nf_ct_expect_alloc(ct);
 691 +               if (!exp) {
 692 +                       ret = NF_DROP;
 693 +                       goto out;
 694 +               }
 695 +
 696 +               be_loport = htons(expinfo.loport);
 697 +
 698 +               nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
 699 +                       &ct->tuplehash[!dir].tuple.src.u3, &ct->tuplehash[!dir].tuple.dst.u3,
 700 +                       IPPROTO_UDP, NULL, &be_loport);
 701 +
 702 +               exp->master = ct;
 703 +
 704 +               exp->expectfn = expected;
 705 +               exp->flags = 0;
 706 +
 707 +               if (expinfo.pbtype == pb_range) {
 708 +                       DEBUGP("Changing expectation mask to handle multiple ports\n");
 709 +                       exp->mask.src.u.udp.port  = 0xfffe;
 710 +               }
 711 +
 712 +               DEBUGP("expect_related %u.%u.%u.%u:%u-%u.%u.%u.%u:%u\n",
 713 +                      NIPQUAD(exp->tuple.src.u3.ip),
 714 +                      ntohs(exp->tuple.src.u.udp.port),
 715 +                      NIPQUAD(exp->tuple.dst.u3.ip),
 716 +                      ntohs(exp->tuple.dst.u.udp.port));
 717 +
 718 +               if (nf_nat_rtsp_hook)
 719 +                       /* pass the request off to the nat helper */
 720 +                       ret = nf_nat_rtsp_hook(skb, ctinfo, hdrsoff, hdrslen, &expinfo, exp);
 721 +               else if (nf_ct_expect_related(exp) != 0) {
 722 +                       INFOP("nf_ct_expect_related failed\n");
 723 +                       ret  = NF_DROP;
 724 +               }
 725 +               nf_ct_expect_put(exp);
 726 +               goto out;
 727 +       }
 728 +out:
 729 +
 730 +       return ret;
 731 +}
 732 +
 733 +
 734 +static inline int
 735 +help_in(struct sk_buff *skb, size_t pktlen,
 736 + struct nf_conn* ct, enum ip_conntrack_info ctinfo)
 737 +{
 738 + return NF_ACCEPT;
 739 +}
 740 +
 741 +static int help(struct sk_buff *skb, unsigned int protoff,
 742 +               struct nf_conn *ct, enum ip_conntrack_info ctinfo)
 743 +{
 744 +       struct tcphdr _tcph, *th;
 745 +       unsigned int dataoff, datalen;
 746 +       char *rb_ptr;
 747 +       int ret = NF_DROP;
 748 +
 749 +       /* Until there's been traffic both ways, don't look in packets. */
 750 +       if (ctinfo != IP_CT_ESTABLISHED &&
 751 +           ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
 752 +               DEBUGP("conntrackinfo = %u\n", ctinfo);
 753 +               return NF_ACCEPT;
 754 +       }
 755 +
 756 +       /* Not whole TCP header? */
 757 +       th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
 758 +
 759 +       if (!th)
 760 +               return NF_ACCEPT;
 761 +
 762 +       /* No data ? */
 763 +       dataoff = protoff + th->doff*4;
 764 +       datalen = skb->len - dataoff;
 765 +       if (dataoff >= skb->len)
 766 +               return NF_ACCEPT;
 767 +
 768 +       spin_lock_bh(&rtsp_buffer_lock);
 769 +       rb_ptr = skb_header_pointer(skb, dataoff,
 770 +                                   skb->len - dataoff, rtsp_buffer);
 771 +       BUG_ON(rb_ptr == NULL);
 772 +
 773 +#if 0
 774 +       /* Checksum invalid?  Ignore. */
 775 +       /* FIXME: Source route IP option packets --RR */
 776 +       if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
 777 +                        csum_partial((char*)tcph, tcplen, 0)))
 778 +       {
 779 +               DEBUGP("bad csum: %p %u %u.%u.%u.%u %u.%u.%u.%u\n",
 780 +                      tcph, tcplen, NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
 781 +               return NF_ACCEPT;
 782 +       }
 783 +#endif
 784 +
 785 +       switch (CTINFO2DIR(ctinfo)) {
 786 +       case IP_CT_DIR_ORIGINAL:
 787 +               ret = help_out(skb, rb_ptr, datalen, ct, ctinfo);
 788 +               break;
 789 +       case IP_CT_DIR_REPLY:
 790 +               DEBUGP("IP_CT_DIR_REPLY\n");
 791 +               /* inbound packet: server->client */
 792 +               ret = NF_ACCEPT;
 793 +               break;
 794 +       }
 795 +
 796 +       spin_unlock_bh(&rtsp_buffer_lock);
 797 +
 798 +       return ret;
 799 +}
 800 +
 801 +static struct nf_conntrack_helper rtsp_helpers[MAX_PORTS];
 802 +static char rtsp_names[MAX_PORTS][10];
 803 +
 804 +/* This function is intentionally _NOT_ defined as __exit */
 805 +static void
 806 +fini(void)
 807 +{
 808 +       int i;
 809 +       for (i = 0; i < num_ports; i++) {
 810 +               DEBUGP("unregistering port %d\n", ports[i]);
 811 +               nf_conntrack_helper_unregister(&rtsp_helpers[i]);
 812 +       }
 813 +       kfree(rtsp_buffer);
 814 +}
 815 +
 816 +static int __init
 817 +init(void)
 818 +{
 819 +       int i, ret;
 820 +       struct nf_conntrack_helper *hlpr;
 821 +       char *tmpname;
 822 +
 823 +       printk("nf_conntrack_rtsp v" IP_NF_RTSP_VERSION " loading\n");
 824 +
 825 +       if (max_outstanding < 1) {
 826 +               printk("nf_conntrack_rtsp: max_outstanding must be a positive integer\n");
 827 +               return -EBUSY;
 828 +       }
 829 +       if (setup_timeout < 0) {
 830 +               printk("nf_conntrack_rtsp: setup_timeout must be a positive integer\n");
 831 +               return -EBUSY;
 832 +       }
 833 +
 834 +       rtsp_buffer = kmalloc(65536, GFP_KERNEL);
 835 +       if (!rtsp_buffer)
 836 +               return -ENOMEM;
 837 +
 838 +       /* If no port given, default to standard rtsp port */
 839 +       if (ports[0] == 0) {
 840 +               ports[0] = RTSP_PORT;
 841 +       }
 842 +
 843 +       for (i = 0; (i < MAX_PORTS) && ports[i]; i++) {
 844 +               hlpr = &rtsp_helpers[i];
 845 +               memset(hlpr, 0, sizeof(struct nf_conntrack_helper));
 846 +               hlpr->tuple.src.u.tcp.port = htons(ports[i]);
 847 +               hlpr->tuple.dst.protonum = IPPROTO_TCP;
 848 +               hlpr->max_expected = max_outstanding;
 849 +               hlpr->timeout = setup_timeout;
 850 +               hlpr->me = THIS_MODULE;
 851 +               hlpr->help = help;
 852 +
 853 +               tmpname = &rtsp_names[i][0];
 854 +               if (ports[i] == RTSP_PORT) {
 855 +                       sprintf(tmpname, "rtsp");
 856 +               } else {
 857 +                       sprintf(tmpname, "rtsp-%d", i);
 858 +               }
 859 +               hlpr->name = tmpname;
 860 +
 861 +               DEBUGP("port #%d: %d\n", i, ports[i]);
 862 +
 863 +               ret = nf_conntrack_helper_register(hlpr);
 864 +
 865 +               if (ret) {
 866 +                       printk("nf_conntrack_rtsp: ERROR registering port %d\n", ports[i]);
 867 +                       fini();
 868 +                       return -EBUSY;
 869 +               }
 870 +               num_ports++;
 871 +       }
 872 +       return 0;
 873 +}
 874 +
 875 +module_init(init);
 876 +module_exit(fini);
 877 +
 878 +EXPORT_SYMBOL(nf_nat_rtsp_hook_expectfn);
 879 +
 880 Index: linux-2.6.24.7/net/ipv4/netfilter/nf_nat_rtsp.c
 881 ===================================================================
 882 --- /dev/null
 883 +++ linux-2.6.24.7/net/ipv4/netfilter/nf_nat_rtsp.c
 884 @@ -0,0 +1,496 @@
 885 +/*
 886 + * RTSP extension for TCP NAT alteration
 887 + * (C) 2003 by Tom Marshall <tmarshall at real.com>
 888 + * based on ip_nat_irc.c
 889 + *
 890 + *      This program is free software; you can redistribute it and/or
 891 + *      modify it under the terms of the GNU General Public License
 892 + *      as published by the Free Software Foundation; either version
 893 + *      2 of the License, or (at your option) any later version.
 894 + *
 895 + * Module load syntax:
 896 + *      insmod nf_nat_rtsp.o ports=port1,port2,...port<MAX_PORTS>
 897 + *                           stunaddr=<address>
 898 + *                           destaction=[auto|strip|none]
 899 + *
 900 + * If no ports are specified, the default will be port 554 only.
 901 + *
 902 + * stunaddr specifies the address used to detect that a client is using STUN.
 903 + * If this address is seen in the destination parameter, it is assumed that
 904 + * the client has already punched a UDP hole in the firewall, so we don't
 905 + * mangle the client_port.  If none is specified, it is autodetected.  It
 906 + * only needs to be set if you have multiple levels of NAT.  It should be
 907 + * set to the external address that the STUN clients detect.  Note that in
 908 + * this case, it will not be possible for clients to use UDP with servers
 909 + * between the NATs.
 910 + *
 911 + * If no destaction is specified, auto is used.
 912 + *   destaction=auto:  strip destination parameter if it is not stunaddr.
 913 + *   destaction=strip: always strip destination parameter (not recommended).
 914 + *   destaction=none:  do not touch destination parameter (not recommended).
 915 + */
 916 +
 917 +#include <linux/module.h>
 918 +#include <net/tcp.h>
 919 +#include <net/netfilter/nf_nat_helper.h>
 920 +#include <net/netfilter/nf_nat_rule.h>
 921 +#include <linux/netfilter/nf_conntrack_rtsp.h>
 922 +#include <net/netfilter/nf_conntrack_expect.h>
 923 +
 924 +#include <linux/inet.h>
 925 +#include <linux/ctype.h>
 926 +#define NF_NEED_STRNCASECMP
 927 +#define NF_NEED_STRTOU16
 928 +#include <linux/netfilter_helpers.h>
 929 +#define NF_NEED_MIME_NEXTLINE
 930 +#include <linux/netfilter_mime.h>
 931 +
 932 +#define INFOP(fmt, args...) printk(KERN_INFO "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
 933 +#if 0
 934 +#define DEBUGP(fmt, args...) printk(KERN_DEBUG "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
 935 +#else
 936 +#define DEBUGP(fmt, args...)
 937 +#endif
 938 +
 939 +#define MAX_PORTS       8
 940 +#define DSTACT_AUTO     0
 941 +#define DSTACT_STRIP    1
 942 +#define DSTACT_NONE     2
 943 +
 944 +static char*    stunaddr = NULL;
 945 +static char*    destaction = NULL;
 946 +
 947 +static u_int32_t extip = 0;
 948 +static int       dstact = 0;
 949 +
 950 +MODULE_AUTHOR("Tom Marshall <tmarshall at real.com>");
 951 +MODULE_DESCRIPTION("RTSP network address translation module");
 952 +MODULE_LICENSE("GPL");
 953 +module_param(stunaddr, charp, 0644);
 954 +MODULE_PARM_DESC(stunaddr, "Address for detecting STUN");
 955 +module_param(destaction, charp, 0644);
 956 +MODULE_PARM_DESC(destaction, "Action for destination parameter (auto/strip/none)");
 957 +
 958 +#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
 959 +
 960 +/*** helper functions ***/
 961 +
 962 +static void
 963 +get_skb_tcpdata(struct sk_buff* skb, char** pptcpdata, uint* ptcpdatalen)
 964 +{
 965 +    struct iphdr*   iph  = ip_hdr(skb);
 966 +    struct tcphdr*  tcph = (void *)iph + ip_hdrlen(skb);
 967 +
 968 +    *pptcpdata = (char*)tcph +  tcph->doff*4;
 969 +    *ptcpdatalen = ((char*)skb_transport_header(skb) + skb->len) - *pptcpdata;
 970 +}
 971 +
 972 +/*** nat functions ***/
 973 +
 974 +/*
 975 + * Mangle the "Transport:" header:
 976 + *   - Replace all occurences of "client_port=<spec>"
 977 + *   - Handle destination parameter
 978 + *
 979 + * In:
 980 + *   ct, ctinfo = conntrack context
 981 + *   skb        = packet
 982 + *   tranoff    = Transport header offset from TCP data
 983 + *   tranlen    = Transport header length (incl. CRLF)
 984 + *   rport_lo   = replacement low  port (host endian)
 985 + *   rport_hi   = replacement high port (host endian)
 986 + *
 987 + * Returns packet size difference.
 988 + *
 989 + * Assumes that a complete transport header is present, ending with CR or LF
 990 + */
 991 +static int
 992 +rtsp_mangle_tran(enum ip_conntrack_info ctinfo,
 993 +                 struct nf_conntrack_expect* exp,
 994 +                                                                struct ip_ct_rtsp_expect* prtspexp,
 995 +                 struct sk_buff* skb, uint tranoff, uint tranlen)
 996 +{
 997 +    char*       ptcp;
 998 +    uint        tcplen;
 999 +    char*       ptran;
1000 +    char        rbuf1[16];      /* Replacement buffer (one port) */
1001 +    uint        rbuf1len;       /* Replacement len (one port) */
1002 +    char        rbufa[16];      /* Replacement buffer (all ports) */
1003 +    uint        rbufalen;       /* Replacement len (all ports) */
1004 +    u_int32_t   newip;
1005 +    u_int16_t   loport, hiport;
1006 +    uint        off = 0;
1007 +    uint        diff;           /* Number of bytes we removed */
1008 +
1009 +    struct nf_conn *ct = exp->master;
1010 +    struct nf_conntrack_tuple *t;
1011 +
1012 +    char    szextaddr[15+1];
1013 +    uint    extaddrlen;
1014 +    int     is_stun;
1015 +
1016 +    get_skb_tcpdata(skb, &ptcp, &tcplen);
1017 +    ptran = ptcp+tranoff;
1018 +
1019 +    if (tranoff+tranlen > tcplen || tcplen-tranoff < tranlen ||
1020 +        tranlen < 10 || !iseol(ptran[tranlen-1]) ||
1021 +        nf_strncasecmp(ptran, "Transport:", 10) != 0)
1022 +    {
1023 +        INFOP("sanity check failed\n");
1024 +        return 0;
1025 +    }
1026 +    off += 10;
1027 +    SKIP_WSPACE(ptcp+tranoff, tranlen, off);
1028 +
1029 +    newip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip;
1030 +    t = &exp->tuple;
1031 +    t->dst.u3.ip = newip;
1032 +
1033 +    extaddrlen = extip ? sprintf(szextaddr, "%u.%u.%u.%u", NIPQUAD(extip))
1034 +                       : sprintf(szextaddr, "%u.%u.%u.%u", NIPQUAD(newip));
1035 +    DEBUGP("stunaddr=%s (%s)\n", szextaddr, (extip?"forced":"auto"));
1036 +
1037 +    rbuf1len = rbufalen = 0;
1038 +    switch (prtspexp->pbtype)
1039 +    {
1040 +    case pb_single:
1041 +        for (loport = prtspexp->loport; loport != 0; loport++) /* XXX: improper wrap? */
1042 +        {
1043 +            t->dst.u.udp.port = htons(loport);
1044 +            if (nf_ct_expect_related(exp) == 0)
1045 +            {
1046 +                DEBUGP("using port %hu\n", loport);
1047 +                break;
1048 +            }
1049 +        }
1050 +        if (loport != 0)
1051 +        {
1052 +            rbuf1len = sprintf(rbuf1, "%hu", loport);
1053 +            rbufalen = sprintf(rbufa, "%hu", loport);
1054 +        }
1055 +        break;
1056 +    case pb_range:
1057 +        for (loport = prtspexp->loport; loport != 0; loport += 2) /* XXX: improper wrap? */
1058 +        {
1059 +            t->dst.u.udp.port = htons(loport);
1060 +            if (nf_ct_expect_related(exp) == 0)
1061 +            {
1062 +                hiport = loport + ~exp->mask.src.u.udp.port;
1063 +                DEBUGP("using ports %hu-%hu\n", loport, hiport);
1064 +                break;
1065 +            }
1066 +        }
1067 +        if (loport != 0)
1068 +        {
1069 +            rbuf1len = sprintf(rbuf1, "%hu", loport);
1070 +            rbufalen = sprintf(rbufa, "%hu-%hu", loport, loport+1);
1071 +        }
1072 +        break;
1073 +    case pb_discon:
1074 +        for (loport = prtspexp->loport; loport != 0; loport++) /* XXX: improper wrap? */
1075 +        {
1076 +            t->dst.u.udp.port = htons(loport);
1077 +            if (nf_ct_expect_related(exp) == 0)
1078 +            {
1079 +                DEBUGP("using port %hu (1 of 2)\n", loport);
1080 +                break;
1081 +            }
1082 +        }
1083 +        for (hiport = prtspexp->hiport; hiport != 0; hiport++) /* XXX: improper wrap? */
1084 +        {
1085 +            t->dst.u.udp.port = htons(hiport);
1086 +            if (nf_ct_expect_related(exp) == 0)
1087 +            {
1088 +                DEBUGP("using port %hu (2 of 2)\n", hiport);
1089 +                break;
1090 +            }
1091 +        }
1092 +        if (loport != 0 && hiport != 0)
1093 +        {
1094 +            rbuf1len = sprintf(rbuf1, "%hu", loport);
1095 +            if (hiport == loport+1)
1096 +            {
1097 +                rbufalen = sprintf(rbufa, "%hu-%hu", loport, hiport);
1098 +            }
1099 +            else
1100 +            {
1101 +                rbufalen = sprintf(rbufa, "%hu/%hu", loport, hiport);
1102 +            }
1103 +        }
1104 +        break;
1105 +    }
1106 +
1107 +    if (rbuf1len == 0)
1108 +    {
1109 +        return 0;   /* cannot get replacement port(s) */
1110 +    }
1111 +
1112 +    /* Transport: tran;field;field=val,tran;field;field=val,... */
1113 +    while (off < tranlen)
1114 +    {
1115 +        uint        saveoff;
1116 +        const char* pparamend;
1117 +        uint        nextparamoff;
1118 +
1119 +        pparamend = memchr(ptran+off, ',', tranlen-off);
1120 +        pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
1121 +        nextparamoff = pparamend-ptcp;
1122 +
1123 +        /*
1124 +         * We pass over each param twice.  On the first pass, we look for a
1125 +         * destination= field.  It is handled by the security policy.  If it
1126 +         * is present, allowed, and equal to our external address, we assume
1127 +         * that STUN is being used and we leave the client_port= field alone.
1128 +         */
1129 +        is_stun = 0;
1130 +        saveoff = off;
1131 +        while (off < nextparamoff)
1132 +        {
1133 +            const char* pfieldend;
1134 +            uint        nextfieldoff;
1135 +
1136 +            pfieldend = memchr(ptran+off, ';', nextparamoff-off);
1137 +            nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
1138 +
1139 +            if (dstact != DSTACT_NONE && strncmp(ptran+off, "destination=", 12) == 0)
1140 +            {
1141 +                if (strncmp(ptran+off+12, szextaddr, extaddrlen) == 0)
1142 +                {
1143 +                    is_stun = 1;
1144 +                }
1145 +                if (dstact == DSTACT_STRIP || (dstact == DSTACT_AUTO && !is_stun))
1146 +                {
1147 +                    diff = nextfieldoff-off;
1148 +                    if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
1149 +                                                         off, diff, NULL, 0))
1150 +                    {
1151 +                        /* mangle failed, all we can do is bail */
1152 +                       nf_ct_unexpect_related(exp);
1153 +                        return 0;
1154 +                    }
1155 +                    get_skb_tcpdata(skb, &ptcp, &tcplen);
1156 +                    ptran = ptcp+tranoff;
1157 +                    tranlen -= diff;
1158 +                    nextparamoff -= diff;
1159 +                    nextfieldoff -= diff;
1160 +                }
1161 +            }
1162 +
1163 +            off = nextfieldoff;
1164 +        }
1165 +        if (is_stun)
1166 +        {
1167 +            continue;
1168 +        }
1169 +        off = saveoff;
1170 +        while (off < nextparamoff)
1171 +        {
1172 +            const char* pfieldend;
1173 +            uint        nextfieldoff;
1174 +
1175 +            pfieldend = memchr(ptran+off, ';', nextparamoff-off);
1176 +            nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
1177 +
1178 +            if (strncmp(ptran+off, "client_port=", 12) == 0)
1179 +            {
1180 +                u_int16_t   port;
1181 +                uint        numlen;
1182 +                uint        origoff;
1183 +                uint        origlen;
1184 +                char*       rbuf    = rbuf1;
1185 +                uint        rbuflen = rbuf1len;
1186 +
1187 +                off += 12;
1188 +                origoff = (ptran-ptcp)+off;
1189 +                origlen = 0;
1190 +                numlen = nf_strtou16(ptran+off, &port);
1191 +                off += numlen;
1192 +                origlen += numlen;
1193 +                if (port != prtspexp->loport)
1194 +                {
1195 +                    DEBUGP("multiple ports found, port %hu ignored\n", port);
1196 +                }
1197 +                else
1198 +                {
1199 +                    if (ptran[off] == '-' || ptran[off] == '/')
1200 +                    {
1201 +                        off++;
1202 +                        origlen++;
1203 +                        numlen = nf_strtou16(ptran+off, &port);
1204 +                        off += numlen;
1205 +                        origlen += numlen;
1206 +                        rbuf = rbufa;
1207 +                        rbuflen = rbufalen;
1208 +                    }
1209 +
1210 +                    /*
1211 +                     * note we cannot just memcpy() if the sizes are the same.
1212 +                     * the mangle function does skb resizing, checks for a
1213 +                     * cloned skb, and updates the checksums.
1214 +                     *
1215 +                     * parameter 4 below is offset from start of tcp data.
1216 +                     */
1217 +                    diff = origlen-rbuflen;
1218 +                    if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
1219 +                                              origoff, origlen, rbuf, rbuflen))
1220 +                    {
1221 +                        /* mangle failed, all we can do is bail */
1222 +                       nf_ct_unexpect_related(exp);
1223 +                        return 0;
1224 +                    }
1225 +                    get_skb_tcpdata(skb, &ptcp, &tcplen);
1226 +                    ptran = ptcp+tranoff;
1227 +                    tranlen -= diff;
1228 +                    nextparamoff -= diff;
1229 +                    nextfieldoff -= diff;
1230 +                }
1231 +            }
1232 +
1233 +            off = nextfieldoff;
1234 +        }
1235 +
1236 +        off = nextparamoff;
1237 +    }
1238 +
1239 +    return 1;
1240 +}
1241 +
1242 +static uint
1243 +help_out(struct sk_buff *skb, enum ip_conntrack_info ctinfo,
1244 +        unsigned int matchoff, unsigned int matchlen, struct ip_ct_rtsp_expect* prtspexp,
1245 +        struct nf_conntrack_expect* exp)
1246 +{
1247 +    char*   ptcp;
1248 +    uint    tcplen;
1249 +    uint    hdrsoff;
1250 +    uint    hdrslen;
1251 +    uint    lineoff;
1252 +    uint    linelen;
1253 +    uint    off;
1254 +
1255 +    //struct iphdr* iph = (struct iphdr*)skb->nh.iph;
1256 +    //struct tcphdr* tcph = (struct tcphdr*)((void*)iph + iph->ihl*4);
1257 +
1258 +    get_skb_tcpdata(skb, &ptcp, &tcplen);
1259 +    hdrsoff = matchoff;//exp->seq - ntohl(tcph->seq);
1260 +    hdrslen = matchlen;
1261 +    off = hdrsoff;
1262 +    DEBUGP("NAT rtsp help_out\n");
1263 +
1264 +    while (nf_mime_nextline(ptcp, hdrsoff+hdrslen, &off, &lineoff, &linelen))
1265 +    {
1266 +        if (linelen == 0)
1267 +        {
1268 +            break;
1269 +        }
1270 +        if (off > hdrsoff+hdrslen)
1271 +        {
1272 +            INFOP("!! overrun !!");
1273 +            break;
1274 +        }
1275 +        DEBUGP("hdr: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
1276 +
1277 +        if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0)
1278 +        {
1279 +            uint oldtcplen = tcplen;
1280 +           DEBUGP("hdr: Transport\n");
1281 +            if (!rtsp_mangle_tran(ctinfo, exp, prtspexp, skb, lineoff, linelen))
1282 +            {
1283 +               DEBUGP("hdr: Transport mangle failed");
1284 +                break;
1285 +            }
1286 +            get_skb_tcpdata(skb, &ptcp, &tcplen);
1287 +            hdrslen -= (oldtcplen-tcplen);
1288 +            off -= (oldtcplen-tcplen);
1289 +            lineoff -= (oldtcplen-tcplen);
1290 +            linelen -= (oldtcplen-tcplen);
1291 +            DEBUGP("rep: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
1292 +        }
1293 +    }
1294 +
1295 +    return NF_ACCEPT;
1296 +}
1297 +
1298 +static unsigned int
1299 +help(struct sk_buff *skb, enum ip_conntrack_info ctinfo,
1300 +     unsigned int matchoff, unsigned int matchlen, struct ip_ct_rtsp_expect* prtspexp,
1301 +     struct nf_conntrack_expect* exp)
1302 +{
1303 +    int dir = CTINFO2DIR(ctinfo);
1304 +    int rc = NF_ACCEPT;
1305 +
1306 +    switch (dir)
1307 +    {
1308 +    case IP_CT_DIR_ORIGINAL:
1309 +        rc = help_out(skb, ctinfo, matchoff, matchlen, prtspexp, exp);
1310 +        break;
1311 +    case IP_CT_DIR_REPLY:
1312 +       DEBUGP("unmangle ! %u\n", ctinfo);
1313 +       /* XXX: unmangle */
1314 +       rc = NF_ACCEPT;
1315 +        break;
1316 +    }
1317 +    //UNLOCK_BH(&ip_rtsp_lock);
1318 +
1319 +    return rc;
1320 +}
1321 +
1322 +static void expected(struct nf_conn* ct, struct nf_conntrack_expect *exp)
1323 +{
1324 +    struct nf_nat_multi_range_compat mr;
1325 +    u_int32_t newdstip, newsrcip, newip;
1326 +
1327 +    struct nf_conn *master = ct->master;
1328 +
1329 +    newdstip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip;
1330 +    newsrcip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip;
1331 +    //FIXME (how to port that ?)
1332 +    //code from 2.4 : newip = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC) ? newsrcip : newdstip;
1333 +    newip = newdstip;
1334 +
1335 +    DEBUGP("newsrcip=%u.%u.%u.%u, newdstip=%u.%u.%u.%u, newip=%u.%u.%u.%u\n",
1336 +           NIPQUAD(newsrcip), NIPQUAD(newdstip), NIPQUAD(newip));
1337 +
1338 +    mr.rangesize = 1;
1339 +    // We don't want to manip the per-protocol, just the IPs.
1340 +    mr.range[0].flags = IP_NAT_RANGE_MAP_IPS;
1341 +    mr.range[0].min_ip = mr.range[0].max_ip = newip;
1342 +
1343 +    nf_nat_setup_info(ct, &mr.range[0], NF_IP_PRE_ROUTING);
1344 +}
1345 +
1346 +
1347 +static void __exit fini(void)
1348 +{
1349 +       nf_nat_rtsp_hook = NULL;
1350 +        nf_nat_rtsp_hook_expectfn = NULL;
1351 +       synchronize_net();
1352 +}
1353 +
1354 +static int __init init(void)
1355 +{
1356 +       printk("nf_nat_rtsp v" IP_NF_RTSP_VERSION " loading\n");
1357 +
1358 +       BUG_ON(nf_nat_rtsp_hook);
1359 +       nf_nat_rtsp_hook = help;
1360 +        nf_nat_rtsp_hook_expectfn = &expected;
1361 +
1362 +       if (stunaddr != NULL)
1363 +               extip = in_aton(stunaddr);
1364 +
1365 +       if (destaction != NULL) {
1366 +               if (strcmp(destaction, "auto") == 0)
1367 +                       dstact = DSTACT_AUTO;
1368 +
1369 +               if (strcmp(destaction, "strip") == 0)
1370 +                       dstact = DSTACT_STRIP;
1371 +
1372 +               if (strcmp(destaction, "none") == 0)
1373 +                       dstact = DSTACT_NONE;
1374 +       }
1375 +
1376 +       return 0;
1377 +}
1378 +
1379 +module_init(init);
1380 +module_exit(fini);