target/linux/generic-2.6/patches-2.6.22/190-netfilter_rtsp.patch

   1 diff -urN linux-2.6.21-rc7/include/linux/netfilter/nf_conntrack_rtsp.h linux-2.6.21-rc7.rtsp/include/linux/netfilter/nf_conntrack_rtsp.h
   2 --- linux-2.6.21-rc7/include/linux/netfilter/nf_conntrack_rtsp.h        1970-01-01 01:00:00.000000000 +0100
   3 +++ linux-2.6.21-rc7.rtsp/include/linux/netfilter/nf_conntrack_rtsp.h   2007-04-16 14:07:06.000000000 +0200
   4 @@ -0,0 +1,63 @@
   5 +/*
   6 + * RTSP extension for IP connection tracking.
   7 + * (C) 2003 by Tom Marshall <tmarshall at real.com>
   8 + * based on ip_conntrack_irc.h
   9 + *
  10 + *      This program is free software; you can redistribute it and/or
  11 + *      modify it under the terms of the GNU General Public License
  12 + *      as published by the Free Software Foundation; either version
  13 + *      2 of the License, or (at your option) any later version.
  14 + */
  15 +#ifndef _IP_CONNTRACK_RTSP_H
  16 +#define _IP_CONNTRACK_RTSP_H
  17 +
  18 +//#define IP_NF_RTSP_DEBUG 1
  19 +#define IP_NF_RTSP_VERSION "0.6.21"
  20 +
  21 +#ifdef __KERNEL__
  22 +/* port block types */
  23 +typedef enum {
  24 +    pb_single,  /* client_port=x */
  25 +    pb_range,   /* client_port=x-y */
  26 +    pb_discon   /* client_port=x/y (rtspbis) */
  27 +} portblock_t;
  28 +
  29 +/* We record seq number and length of rtsp headers here, all in host order. */
  30 +
  31 +/*
  32 + * This structure is per expected connection.  It is a member of struct
  33 + * ip_conntrack_expect.  The TCP SEQ for the conntrack expect is stored
  34 + * there and we are expected to only store the length of the data which
  35 + * needs replaced.  If a packet contains multiple RTSP messages, we create
  36 + * one expected connection per message.
  37 + *
  38 + * We use these variables to mark the entire header block.  This may seem
  39 + * like overkill, but the nature of RTSP requires it.  A header may appear
  40 + * multiple times in a message.  We must treat two Transport headers the
  41 + * same as one Transport header with two entries.
  42 + */
  43 +struct ip_ct_rtsp_expect
  44 +{
  45 +    u_int32_t   len;        /* length of header block */
  46 +    portblock_t pbtype;     /* Type of port block that was requested */
  47 +    u_int16_t   loport;     /* Port that was requested, low or first */
  48 +    u_int16_t   hiport;     /* Port that was requested, high or second */
  49 +#if 0
  50 +    uint        method;     /* RTSP method */
  51 +    uint        cseq;       /* CSeq from request */
  52 +#endif
  53 +};
  54 +
  55 +extern unsigned int (*nf_nat_rtsp_hook)(struct sk_buff **pskb,
  56 +                                enum ip_conntrack_info ctinfo,
  57 +                                unsigned int matchoff, unsigned int matchlen,
  58 +                                struct ip_ct_rtsp_expect *prtspexp,
  59 +                                struct nf_conntrack_expect *exp);
  60 +
  61 +extern void (*nf_nat_rtsp_hook_expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
  62 +
  63 +#define RTSP_PORT   554
  64 +
  65 +#endif /* __KERNEL__ */
  66 +
  67 +#endif /* _IP_CONNTRACK_RTSP_H */
  68 diff -urN linux-2.6.21-rc7/include/linux/netfilter_helpers.h linux-2.6.21-rc7.rtsp/include/linux/netfilter_helpers.h
  69 --- linux-2.6.21-rc7/include/linux/netfilter_helpers.h  1970-01-01 01:00:00.000000000 +0100
  70 +++ linux-2.6.21-rc7.rtsp/include/linux/netfilter_helpers.h     2007-04-15 00:34:57.000000000 +0200
  71 @@ -0,0 +1,133 @@
  72 +/*
  73 + * Helpers for netfiler modules.  This file provides implementations for basic
  74 + * functions such as strncasecmp(), etc.
  75 + *
  76 + * gcc will warn for defined but unused functions, so we only include the
  77 + * functions requested.  The following macros are used:
  78 + *   NF_NEED_STRNCASECMP        nf_strncasecmp()
  79 + *   NF_NEED_STRTOU16           nf_strtou16()
  80 + *   NF_NEED_STRTOU32           nf_strtou32()
  81 + */
  82 +#ifndef _NETFILTER_HELPERS_H
  83 +#define _NETFILTER_HELPERS_H
  84 +
  85 +/* Only include these functions for kernel code. */
  86 +#ifdef __KERNEL__
  87 +
  88 +#include <linux/ctype.h>
  89 +#define iseol(c) ( (c) == '\r' || (c) == '\n' )
  90 +
  91 +/*
  92 + * The standard strncasecmp()
  93 + */
  94 +#ifdef NF_NEED_STRNCASECMP
  95 +static int
  96 +nf_strncasecmp(const char* s1, const char* s2, u_int32_t len)
  97 +{
  98 +    if (s1 == NULL || s2 == NULL)
  99 +    {
 100 +        if (s1 == NULL && s2 == NULL)
 101 +        {
 102 +            return 0;
 103 +        }
 104 +        return (s1 == NULL) ? -1 : 1;
 105 +    }
 106 +    while (len > 0 && tolower(*s1) == tolower(*s2))
 107 +    {
 108 +        len--;
 109 +        s1++;
 110 +        s2++;
 111 +    }
 112 +    return ( (len == 0) ? 0 : (tolower(*s1) - tolower(*s2)) );
 113 +}
 114 +#endif /* NF_NEED_STRNCASECMP */
 115 +
 116 +/*
 117 + * Parse a string containing a 16-bit unsigned integer.
 118 + * Returns the number of chars used, or zero if no number is found.
 119 + */
 120 +#ifdef NF_NEED_STRTOU16
 121 +static int
 122 +nf_strtou16(const char* pbuf, u_int16_t* pval)
 123 +{
 124 +    int n = 0;
 125 +
 126 +    *pval = 0;
 127 +    while (isdigit(pbuf[n]))
 128 +    {
 129 +        *pval = (*pval * 10) + (pbuf[n] - '0');
 130 +        n++;
 131 +    }
 132 +
 133 +    return n;
 134 +}
 135 +#endif /* NF_NEED_STRTOU16 */
 136 +
 137 +/*
 138 + * Parse a string containing a 32-bit unsigned integer.
 139 + * Returns the number of chars used, or zero if no number is found.
 140 + */
 141 +#ifdef NF_NEED_STRTOU32
 142 +static int
 143 +nf_strtou32(const char* pbuf, u_int32_t* pval)
 144 +{
 145 +    int n = 0;
 146 +
 147 +    *pval = 0;
 148 +    while (pbuf[n] >= '0' && pbuf[n] <= '9')
 149 +    {
 150 +        *pval = (*pval * 10) + (pbuf[n] - '0');
 151 +        n++;
 152 +    }
 153 +
 154 +    return n;
 155 +}
 156 +#endif /* NF_NEED_STRTOU32 */
 157 +
 158 +/*
 159 + * Given a buffer and length, advance to the next line and mark the current
 160 + * line.
 161 + */
 162 +#ifdef NF_NEED_NEXTLINE
 163 +static int
 164 +nf_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
 165 +{
 166 +    uint    off = *poff;
 167 +    uint    physlen = 0;
 168 +
 169 +    if (off >= len)
 170 +    {
 171 +        return 0;
 172 +    }
 173 +
 174 +    while (p[off] != '\n')
 175 +    {
 176 +        if (len-off <= 1)
 177 +        {
 178 +            return 0;
 179 +        }
 180 +
 181 +        physlen++;
 182 +        off++;
 183 +    }
 184 +
 185 +    /* if we saw a crlf, physlen needs adjusted */
 186 +    if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
 187 +    {
 188 +        physlen--;
 189 +    }
 190 +
 191 +    /* advance past the newline */
 192 +    off++;
 193 +
 194 +    *plineoff = *poff;
 195 +    *plinelen = physlen;
 196 +    *poff = off;
 197 +
 198 +    return 1;
 199 +}
 200 +#endif /* NF_NEED_NEXTLINE */
 201 +
 202 +#endif /* __KERNEL__ */
 203 +
 204 +#endif /* _NETFILTER_HELPERS_H */
 205 diff -urN linux-2.6.21-rc7/include/linux/netfilter_mime.h linux-2.6.21-rc7.rtsp/include/linux/netfilter_mime.h
 206 --- linux-2.6.21-rc7/include/linux/netfilter_mime.h     1970-01-01 01:00:00.000000000 +0100
 207 +++ linux-2.6.21-rc7.rtsp/include/linux/netfilter_mime.h        2007-04-15 00:34:57.000000000 +0200
 208 @@ -0,0 +1,89 @@
 209 +/*
 210 + * MIME functions for netfilter modules.  This file provides implementations
 211 + * for basic MIME parsing.  MIME headers are used in many protocols, such as
 212 + * HTTP, RTSP, SIP, etc.
 213 + *
 214 + * gcc will warn for defined but unused functions, so we only include the
 215 + * functions requested.  The following macros are used:
 216 + *   NF_NEED_MIME_NEXTLINE      nf_mime_nextline()
 217 + */
 218 +#ifndef _NETFILTER_MIME_H
 219 +#define _NETFILTER_MIME_H
 220 +
 221 +/* Only include these functions for kernel code. */
 222 +#ifdef __KERNEL__
 223 +
 224 +#include <linux/ctype.h>
 225 +
 226 +/*
 227 + * Given a buffer and length, advance to the next line and mark the current
 228 + * line.  If the current line is empty, *plinelen will be set to zero.  If
 229 + * not, it will be set to the actual line length (including CRLF).
 230 + *
 231 + * 'line' in this context means logical line (includes LWS continuations).
 232 + * Returns 1 on success, 0 on failure.
 233 + */
 234 +#ifdef NF_NEED_MIME_NEXTLINE
 235 +static int
 236 +nf_mime_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
 237 +{
 238 +    uint    off = *poff;
 239 +    uint    physlen = 0;
 240 +    int     is_first_line = 1;
 241 +
 242 +    if (off >= len)
 243 +    {
 244 +        return 0;
 245 +    }
 246 +
 247 +    do
 248 +    {
 249 +        while (p[off] != '\n')
 250 +        {
 251 +            if (len-off <= 1)
 252 +            {
 253 +                return 0;
 254 +            }
 255 +
 256 +            physlen++;
 257 +            off++;
 258 +        }
 259 +
 260 +        /* if we saw a crlf, physlen needs adjusted */
 261 +        if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
 262 +        {
 263 +            physlen--;
 264 +        }
 265 +
 266 +        /* advance past the newline */
 267 +        off++;
 268 +
 269 +        /* check for an empty line */
 270 +        if (physlen == 0)
 271 +        {
 272 +            break;
 273 +        }
 274 +
 275 +        /* check for colon on the first physical line */
 276 +        if (is_first_line)
 277 +        {
 278 +            is_first_line = 0;
 279 +            if (memchr(p+(*poff), ':', physlen) == NULL)
 280 +            {
 281 +                return 0;
 282 +            }
 283 +        }
 284 +    }
 285 +    while (p[off] == ' ' || p[off] == '\t');
 286 +
 287 +    *plineoff = *poff;
 288 +    *plinelen = (physlen == 0) ? 0 : (off - *poff);
 289 +    *poff = off;
 290 +
 291 +    return 1;
 292 +}
 293 +#endif /* NF_NEED_MIME_NEXTLINE */
 294 +
 295 +#endif /* __KERNEL__ */
 296 +
 297 +#endif /* _NETFILTER_MIME_H */
 298 diff -urN linux-2.6.21-rc7/net/ipv4/netfilter/Makefile linux-2.6.21-rc7.rtsp/net/ipv4/netfilter/Makefile
 299 --- linux-2.6.21-rc7/net/ipv4/netfilter/Makefile        2007-04-18 23:26:10.000000000 +0200
 300 +++ linux-2.6.21-rc7.rtsp/net/ipv4/netfilter/Makefile   2007-04-18 21:17:33.000000000 +0200
 301 @@ -64,6 +66,7 @@
 302  obj-$(CONFIG_NF_NAT_FTP) += nf_nat_ftp.o
 303  obj-$(CONFIG_NF_NAT_H323) += nf_nat_h323.o
 304  obj-$(CONFIG_NF_NAT_IRC) += nf_nat_irc.o
 305 +obj-$(CONFIG_NF_NAT_RTSP) += nf_nat_rtsp.o
 306  obj-$(CONFIG_NF_NAT_PPTP) += nf_nat_pptp.o
 307  obj-$(CONFIG_NF_NAT_SIP) += nf_nat_sip.o
 308  obj-$(CONFIG_NF_NAT_SNMP_BASIC) += nf_nat_snmp_basic.o
 309 diff -urN linux-2.6.21-rc7/net/netfilter/Kconfig linux-2.6.21-rc7.rtsp/net/netfilter/Kconfig
 310 --- linux-2.6.21-rc7/net/netfilter/Kconfig      2007-04-18 23:26:10.000000000 +0200
 311 +++ linux-2.6.21-rc7.rtsp/net/netfilter/Kconfig 2007-04-18 22:25:13.000000000 +0200
 312 @@ -271,6 +272,16 @@
 313
 314           To compile it as a module, choose M here.  If unsure, say N.
 315
 316 +config NF_CONNTRACK_RTSP
 317 +       tristate "RTSP protocol support"
 318 +       depends on NF_CONNTRACK
 319 +       help
 320 +               Support the RTSP protocol.  This allows UDP transports to be setup
 321 +               properly, including RTP and RDT.
 322 +
 323 +               If you want to compile it as a module, say 'M' here and read
 324 +               Documentation/modules.txt.  If unsure, say 'Y'.
 325 +
 326  config NF_CT_NETLINK
 327         tristate 'Connection tracking netlink interface (EXPERIMENTAL)'
 328         depends on EXPERIMENTAL && NF_CONNTRACK && NETFILTER_NETLINK
 329 diff -urN linux-2.6.21-rc7/net/netfilter/Makefile linux-2.6.21-rc7.rtsp/net/netfilter/Makefile
 330 --- linux-2.6.21-rc7/net/netfilter/Makefile     2007-04-18 23:26:10.000000000 +0200
 331 +++ linux-2.6.21-rc7.rtsp/net/netfilter/Makefile        2007-04-18 21:17:33.000000000 +0200
 332 @@ -32,6 +32,7 @@
 333  obj-$(CONFIG_NF_CONNTRACK_SANE) += nf_conntrack_sane.o
 334  obj-$(CONFIG_NF_CONNTRACK_SIP) += nf_conntrack_sip.o
 335  obj-$(CONFIG_NF_CONNTRACK_TFTP) += nf_conntrack_tftp.o
 336 +obj-$(CONFIG_NF_CONNTRACK_RTSP) += nf_conntrack_rtsp.o
 337
 338  # generic X tables
 339  obj-$(CONFIG_NETFILTER_XTABLES) += x_tables.o xt_tcpudp.o
 340 --- linux-2.6.22.1/net/ipv4/netfilter/Kconfig.orig      2007-07-29 23:57:51.000000000 +0200
 341 +++ linux-2.6.22.1/net/ipv4/netfilter/Kconfig   2007-07-30 00:00:19.000000000 +0200
 342 @@ -274,6 +274,11 @@
 343         depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
 344         default NF_NAT && NF_CONNTRACK_IRC
 345
 346 +config NF_NAT_RTSP
 347 +       tristate
 348 +       depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
 349 +       default NF_NAT && NF_CONNTRACK_RTSP
 350 +
 351  config NF_NAT_TFTP
 352         tristate
 353         depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
 354 --- linux-2.6.22.1/net/netfilter/nf_conntrack_rtsp.c.orig       2007-07-30 17:37:14.000000000 +0200
 355 +++ linux-2.6.22.1/net/netfilter/nf_conntrack_rtsp.c    2007-07-30 00:03:07.000000000 +0200
 356 @@ -0,0 +1,515 @@
 357 +/*
 358 + * RTSP extension for IP connection tracking
 359 + * (C) 2003 by Tom Marshall <tmarshall at real.com>
 360 + * based on ip_conntrack_irc.c
 361 + *
 362 + *      This program is free software; you can redistribute it and/or
 363 + *      modify it under the terms of the GNU General Public License
 364 + *      as published by the Free Software Foundation; either version
 365 + *      2 of the License, or (at your option) any later version.
 366 + *
 367 + * Module load syntax:
 368 + *   insmod nf_conntrack_rtsp.o ports=port1,port2,...port<MAX_PORTS>
 369 + *                              max_outstanding=n setup_timeout=secs
 370 + *
 371 + * If no ports are specified, the default will be port 554.
 372 + *
 373 + * With max_outstanding you can define the maximum number of not yet
 374 + * answered SETUP requests per RTSP session (default 8).
 375 + * With setup_timeout you can specify how long the system waits for
 376 + * an expected data channel (default 300 seconds).
 377 + *
 378 + * 2005-02-13: Harald Welte <laforge at netfilter.org>
 379 + *     - port to 2.6
 380 + *     - update to recent post-2.6.11 api changes
 381 + * 2006-09-14: Steven Van Acker <deepstar at singularity.be>
 382 + *      - removed calls to NAT code from conntrack helper: NAT no longer needed to use rtsp-conntrack
 383 + * 2007-04-18: Michael Guntsche <mike at it-loops.com>
 384 + *                     - Port to new NF API
 385 + */
 386 +
 387 +#include <linux/module.h>
 388 +#include <linux/netfilter.h>
 389 +#include <linux/ip.h>
 390 +#include <linux/inet.h>
 391 +#include <net/tcp.h>
 392 +
 393 +#include <net/netfilter/nf_conntrack.h>
 394 +#include <net/netfilter/nf_conntrack_expect.h>
 395 +#include <net/netfilter/nf_conntrack_helper.h>
 396 +#include <linux/netfilter/nf_conntrack_rtsp.h>
 397 +
 398 +#define NF_NEED_STRNCASECMP
 399 +#define NF_NEED_STRTOU16
 400 +#define NF_NEED_STRTOU32
 401 +#define NF_NEED_NEXTLINE
 402 +#include <linux/netfilter_helpers.h>
 403 +#define NF_NEED_MIME_NEXTLINE
 404 +#include <linux/netfilter_mime.h>
 405 +
 406 +#include <linux/ctype.h>
 407 +#define MAX_SIMUL_SETUP 8 /* XXX: use max_outstanding */
 408 +#define INFOP(fmt, args...) printk(KERN_INFO "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
 409 +#if 0
 410 +#define DEBUGP(fmt, args...) printk(KERN_DEBUG "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
 411 +#else
 412 +#define DEBUGP(fmt, args...)
 413 +#endif
 414 +
 415 +#define MAX_PORTS 8
 416 +static int ports[MAX_PORTS];
 417 +static int num_ports = 0;
 418 +static int max_outstanding = 8;
 419 +static unsigned int setup_timeout = 300;
 420 +
 421 +MODULE_AUTHOR("Tom Marshall <tmarshall at real.com>");
 422 +MODULE_DESCRIPTION("RTSP connection tracking module");
 423 +MODULE_LICENSE("GPL");
 424 +module_param_array(ports, int, &num_ports, 0400);
 425 +MODULE_PARM_DESC(ports, "port numbers of RTSP servers");
 426 +module_param(max_outstanding, int, 0400);
 427 +MODULE_PARM_DESC(max_outstanding, "max number of outstanding SETUP requests per RTSP session");
 428 +module_param(setup_timeout, int, 0400);
 429 +MODULE_PARM_DESC(setup_timeout, "timeout on for unestablished data channels");
 430 +
 431 +static char *rtsp_buffer;
 432 +static DEFINE_SPINLOCK(rtsp_buffer_lock);
 433 +
 434 +unsigned int (*nf_nat_rtsp_hook)(struct sk_buff **pskb,
 435 +                                enum ip_conntrack_info ctinfo,
 436 +                                unsigned int matchoff, unsigned int matchlen,struct ip_ct_rtsp_expect* prtspexp,
 437 +                                struct nf_conntrack_expect *exp);
 438 +void (*nf_nat_rtsp_hook_expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
 439 +
 440 +EXPORT_SYMBOL_GPL(nf_nat_rtsp_hook);
 441 +
 442 +/*
 443 + * Max mappings we will allow for one RTSP connection (for RTP, the number
 444 + * of allocated ports is twice this value).  Note that SMIL burns a lot of
 445 + * ports so keep this reasonably high.  If this is too low, you will see a
 446 + * lot of "no free client map entries" messages.
 447 + */
 448 +#define MAX_PORT_MAPS 16
 449 +
 450 +/*** default port list was here in the masq code: 554, 3030, 4040 ***/
 451 +
 452 +#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
 453 +
 454 +/*
 455 + * Parse an RTSP packet.
 456 + *
 457 + * Returns zero if parsing failed.
 458 + *
 459 + * Parameters:
 460 + *  IN      ptcp        tcp data pointer
 461 + *  IN      tcplen      tcp data len
 462 + *  IN/OUT  ptcpoff     points to current tcp offset
 463 + *  OUT     phdrsoff    set to offset of rtsp headers
 464 + *  OUT     phdrslen    set to length of rtsp headers
 465 + *  OUT     pcseqoff    set to offset of CSeq header
 466 + *  OUT     pcseqlen    set to length of CSeq header
 467 + */
 468 +static int
 469 +rtsp_parse_message(char* ptcp, uint tcplen, uint* ptcpoff,
 470 +                   uint* phdrsoff, uint* phdrslen,
 471 +                   uint* pcseqoff, uint* pcseqlen,
 472 +                   uint* transoff, uint* translen)
 473 +{
 474 +       uint    entitylen = 0;
 475 +       uint    lineoff;
 476 +       uint    linelen;
 477 +
 478 +       if (!nf_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
 479 +               return 0;
 480 +
 481 +       *phdrsoff = *ptcpoff;
 482 +       while (nf_mime_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen)) {
 483 +               if (linelen == 0) {
 484 +                       if (entitylen > 0)
 485 +                               *ptcpoff += min(entitylen, tcplen - *ptcpoff);
 486 +                       break;
 487 +               }
 488 +               if (lineoff+linelen > tcplen) {
 489 +                       INFOP("!! overrun !!\n");
 490 +                       break;
 491 +               }
 492 +
 493 +               if (nf_strncasecmp(ptcp+lineoff, "CSeq:", 5) == 0) {
 494 +                       *pcseqoff = lineoff;
 495 +                       *pcseqlen = linelen;
 496 +               }
 497 +
 498 +               if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0) {
 499 +                       *transoff = lineoff;
 500 +                       *translen = linelen;
 501 +               }
 502 +
 503 +               if (nf_strncasecmp(ptcp+lineoff, "Content-Length:", 15) == 0) {
 504 +                       uint off = lineoff+15;
 505 +                       SKIP_WSPACE(ptcp+lineoff, linelen, off);
 506 +                       nf_strtou32(ptcp+off, &entitylen);
 507 +               }
 508 +       }
 509 +       *phdrslen = (*ptcpoff) - (*phdrsoff);
 510 +
 511 +       return 1;
 512 +}
 513 +
 514 +/*
 515 + * Find lo/hi client ports (if any) in transport header
 516 + * In:
 517 + *   ptcp, tcplen = packet
 518 + *   tranoff, tranlen = buffer to search
 519 + *
 520 + * Out:
 521 + *   pport_lo, pport_hi = lo/hi ports (host endian)
 522 + *
 523 + * Returns nonzero if any client ports found
 524 + *
 525 + * Note: it is valid (and expected) for the client to request multiple
 526 + * transports, so we need to parse the entire line.
 527 + */
 528 +static int
 529 +rtsp_parse_transport(char* ptran, uint tranlen,
 530 +                     struct ip_ct_rtsp_expect* prtspexp)
 531 +{
 532 +       int     rc = 0;
 533 +       uint    off = 0;
 534 +
 535 +       if (tranlen < 10 || !iseol(ptran[tranlen-1]) ||
 536 +           nf_strncasecmp(ptran, "Transport:", 10) != 0) {
 537 +               INFOP("sanity check failed\n");
 538 +               return 0;
 539 +       }
 540 +
 541 +       DEBUGP("tran='%.*s'\n", (int)tranlen, ptran);
 542 +       off += 10;
 543 +       SKIP_WSPACE(ptran, tranlen, off);
 544 +
 545 +       /* Transport: tran;field;field=val,tran;field;field=val,... */
 546 +       while (off < tranlen) {
 547 +               const char* pparamend;
 548 +               uint        nextparamoff;
 549 +
 550 +               pparamend = memchr(ptran+off, ',', tranlen-off);
 551 +               pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
 552 +               nextparamoff = pparamend-ptran;
 553 +
 554 +               while (off < nextparamoff) {
 555 +                       const char* pfieldend;
 556 +                       uint        nextfieldoff;
 557 +
 558 +                       pfieldend = memchr(ptran+off, ';', nextparamoff-off);
 559 +                       nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
 560 +
 561 +                       if (strncmp(ptran+off, "client_port=", 12) == 0) {
 562 +                               u_int16_t   port;
 563 +                               uint        numlen;
 564 +
 565 +                               off += 12;
 566 +                               numlen = nf_strtou16(ptran+off, &port);
 567 +                               off += numlen;
 568 +                               if (prtspexp->loport != 0 && prtspexp->loport != port)
 569 +                                       DEBUGP("multiple ports found, port %hu ignored\n", port);
 570 +                               else {
 571 +                                       DEBUGP("lo port found : %hu\n", port);
 572 +                                       prtspexp->loport = prtspexp->hiport = port;
 573 +                                       if (ptran[off] == '-') {
 574 +                                               off++;
 575 +                                               numlen = nf_strtou16(ptran+off, &port);
 576 +                                               off += numlen;
 577 +                                               prtspexp->pbtype = pb_range;
 578 +                                               prtspexp->hiport = port;
 579 +
 580 +                                               // If we have a range, assume rtp:
 581 +                                               // loport must be even, hiport must be loport+1
 582 +                                               if ((prtspexp->loport & 0x0001) != 0 ||
 583 +                                                   prtspexp->hiport != prtspexp->loport+1) {
 584 +                                                       DEBUGP("incorrect range: %hu-%hu, correcting\n",
 585 +                                                              prtspexp->loport, prtspexp->hiport);
 586 +                                                       prtspexp->loport &= 0xfffe;
 587 +                                                       prtspexp->hiport = prtspexp->loport+1;
 588 +                                               }
 589 +                                       } else if (ptran[off] == '/') {
 590 +                                               off++;
 591 +                                               numlen = nf_strtou16(ptran+off, &port);
 592 +                                               off += numlen;
 593 +                                               prtspexp->pbtype = pb_discon;
 594 +                                               prtspexp->hiport = port;
 595 +                                       }
 596 +                                       rc = 1;
 597 +                               }
 598 +                       }
 599 +
 600 +                       /*
 601 +                        * Note we don't look for the destination parameter here.
 602 +                        * If we are using NAT, the NAT module will handle it.  If not,
 603 +                        * and the client is sending packets elsewhere, the expectation
 604 +                        * will quietly time out.
 605 +                        */
 606 +
 607 +                       off = nextfieldoff;
 608 +               }
 609 +
 610 +               off = nextparamoff;
 611 +       }
 612 +
 613 +       return rc;
 614 +}
 615 +
 616 +void expected(struct nf_conn *ct, struct nf_conntrack_expect *exp)
 617 +{
 618 +    if(nf_nat_rtsp_hook_expectfn) {
 619 +        nf_nat_rtsp_hook_expectfn(ct,exp);
 620 +    }
 621 +}
 622 +
 623 +/*** conntrack functions ***/
 624 +
 625 +/* outbound packet: client->server */
 626 +
 627 +static inline int
 628 +help_out(struct sk_buff **pskb, unsigned char *rb_ptr, unsigned int datalen,
 629 +                struct nf_conn *ct, enum ip_conntrack_info ctinfo)
 630 +{
 631 +       struct ip_ct_rtsp_expect expinfo;
 632 +
 633 +       int dir = CTINFO2DIR(ctinfo);   /* = IP_CT_DIR_ORIGINAL */
 634 +       //struct  tcphdr* tcph = (void*)iph + iph->ihl * 4;
 635 +       //uint    tcplen = pktlen - iph->ihl * 4;
 636 +       char*   pdata = rb_ptr;
 637 +       //uint    datalen = tcplen - tcph->doff * 4;
 638 +       uint    dataoff = 0;
 639 +       int ret = NF_ACCEPT;
 640 +
 641 +       struct nf_conntrack_expect *exp;
 642 +
 643 +       __be16 be_loport;
 644 +
 645 +       memset(&expinfo, 0, sizeof(expinfo));
 646 +
 647 +       while (dataoff < datalen) {
 648 +               uint    cmdoff = dataoff;
 649 +               uint    hdrsoff = 0;
 650 +               uint    hdrslen = 0;
 651 +               uint    cseqoff = 0;
 652 +               uint    cseqlen = 0;
 653 +               uint    transoff = 0;
 654 +               uint    translen = 0;
 655 +               uint    off;
 656 +
 657 +               if (!rtsp_parse_message(pdata, datalen, &dataoff,
 658 +                                       &hdrsoff, &hdrslen,
 659 +                                       &cseqoff, &cseqlen,
 660 +                                       &transoff, &translen))
 661 +                       break;      /* not a valid message */
 662 +
 663 +               if (strncmp(pdata+cmdoff, "SETUP ", 6) != 0)
 664 +                       continue;   /* not a SETUP message */
 665 +               DEBUGP("found a setup message\n");
 666 +
 667 +               off = 0;
 668 +               if(translen) {
 669 +                       rtsp_parse_transport(pdata+transoff, translen, &expinfo);
 670 +               }
 671 +
 672 +               if (expinfo.loport == 0) {
 673 +                       DEBUGP("no udp transports found\n");
 674 +                       continue;   /* no udp transports found */
 675 +               }
 676 +
 677 +               DEBUGP("udp transport found, ports=(%d,%hu,%hu)\n",
 678 +                      (int)expinfo.pbtype, expinfo.loport, expinfo.hiport);
 679 +
 680 +               exp = nf_conntrack_expect_alloc(ct);
 681 +               if (!exp) {
 682 +                       ret = NF_DROP;
 683 +                       goto out;
 684 +               }
 685 +
 686 +               be_loport = htons(expinfo.loport);
 687 +
 688 +               nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
 689 +                       &ct->tuplehash[!dir].tuple.src.u3, &ct->tuplehash[!dir].tuple.dst.u3,
 690 +                       IPPROTO_UDP, NULL, &be_loport);
 691 +
 692 +               exp->master = ct;
 693 +
 694 +               exp->expectfn = expected;
 695 +               exp->flags = 0;
 696 +
 697 +               if (expinfo.pbtype == pb_range) {
 698 +                       DEBUGP("Changing expectation mask to handle multiple ports\n");
 699 +                       exp->mask.dst.u.udp.port  = 0xfffe;
 700 +               }
 701 +
 702 +               DEBUGP("expect_related %u.%u.%u.%u:%u-%u.%u.%u.%u:%u\n",
 703 +                      NIPQUAD(exp->tuple.src.u3.ip),
 704 +                      ntohs(exp->tuple.src.u.udp.port),
 705 +                      NIPQUAD(exp->tuple.dst.u3.ip),
 706 +                      ntohs(exp->tuple.dst.u.udp.port));
 707 +
 708 +               if (nf_nat_rtsp_hook)
 709 +                       /* pass the request off to the nat helper */
 710 +                       ret = nf_nat_rtsp_hook(pskb, ctinfo, hdrsoff, hdrslen, &expinfo, exp);
 711 +               else if (nf_conntrack_expect_related(exp) != 0) {
 712 +                       INFOP("nf_conntrack_expect_related failed\n");
 713 +                       ret  = NF_DROP;
 714 +               }
 715 +               nf_conntrack_expect_put(exp);
 716 +               goto out;
 717 +       }
 718 +out:
 719 +
 720 +       return ret;
 721 +}
 722 +
 723 +
 724 +static inline int
 725 +help_in(struct sk_buff **pskb, size_t pktlen,
 726 + struct nf_conn* ct, enum ip_conntrack_info ctinfo)
 727 +{
 728 + return NF_ACCEPT;
 729 +}
 730 +
 731 +static int help(struct sk_buff **pskb, unsigned int protoff,
 732 +               struct nf_conn *ct, enum ip_conntrack_info ctinfo)
 733 +{
 734 +       struct tcphdr _tcph, *th;
 735 +       unsigned int dataoff, datalen;
 736 +       char *rb_ptr;
 737 +       int ret = NF_DROP;
 738 +
 739 +       /* Until there's been traffic both ways, don't look in packets. */
 740 +       if (ctinfo != IP_CT_ESTABLISHED &&
 741 +           ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
 742 +               DEBUGP("conntrackinfo = %u\n", ctinfo);
 743 +               return NF_ACCEPT;
 744 +       }
 745 +
 746 +       /* Not whole TCP header? */
 747 +       th = skb_header_pointer(*pskb,protoff, sizeof(_tcph), &_tcph);
 748 +
 749 +       if (!th)
 750 +               return NF_ACCEPT;
 751 +
 752 +       /* No data ? */
 753 +       dataoff = protoff + th->doff*4;
 754 +       datalen = (*pskb)->len - dataoff;
 755 +       if (dataoff >= (*pskb)->len)
 756 +               return NF_ACCEPT;
 757 +
 758 +       spin_lock_bh(&rtsp_buffer_lock);
 759 +       rb_ptr = skb_header_pointer(*pskb, dataoff,
 760 +                                   (*pskb)->len - dataoff, rtsp_buffer);
 761 +       BUG_ON(rb_ptr == NULL);
 762 +
 763 +#if 0
 764 +       /* Checksum invalid?  Ignore. */
 765 +       /* FIXME: Source route IP option packets --RR */
 766 +       if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
 767 +                        csum_partial((char*)tcph, tcplen, 0)))
 768 +       {
 769 +               DEBUGP("bad csum: %p %u %u.%u.%u.%u %u.%u.%u.%u\n",
 770 +                      tcph, tcplen, NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
 771 +               return NF_ACCEPT;
 772 +       }
 773 +#endif
 774 +
 775 +       switch (CTINFO2DIR(ctinfo)) {
 776 +       case IP_CT_DIR_ORIGINAL:
 777 +               ret = help_out(pskb, rb_ptr, datalen, ct, ctinfo);
 778 +               break;
 779 +       case IP_CT_DIR_REPLY:
 780 +               DEBUGP("IP_CT_DIR_REPLY\n");
 781 +               /* inbound packet: server->client */
 782 +               ret = NF_ACCEPT;
 783 +               break;
 784 +       }
 785 +
 786 +       spin_unlock_bh(&rtsp_buffer_lock);
 787 +
 788 +       return ret;
 789 +}
 790 +
 791 +static struct nf_conntrack_helper rtsp_helpers[MAX_PORTS];
 792 +static char rtsp_names[MAX_PORTS][10];
 793 +
 794 +/* This function is intentionally _NOT_ defined as __exit */
 795 +static void
 796 +fini(void)
 797 +{
 798 +       int i;
 799 +       for (i = 0; i < num_ports; i++) {
 800 +               DEBUGP("unregistering port %d\n", ports[i]);
 801 +               nf_conntrack_helper_unregister(&rtsp_helpers[i]);
 802 +       }
 803 +       kfree(rtsp_buffer);
 804 +}
 805 +
 806 +static int __init
 807 +init(void)
 808 +{
 809 +       int i, ret;
 810 +       struct nf_conntrack_helper *hlpr;
 811 +       char *tmpname;
 812 +
 813 +       printk("nf_conntrack_rtsp v" IP_NF_RTSP_VERSION " loading\n");
 814 +
 815 +       if (max_outstanding < 1) {
 816 +               printk("nf_conntrack_rtsp: max_outstanding must be a positive integer\n");
 817 +               return -EBUSY;
 818 +       }
 819 +       if (setup_timeout < 0) {
 820 +               printk("nf_conntrack_rtsp: setup_timeout must be a positive integer\n");
 821 +               return -EBUSY;
 822 +       }
 823 +
 824 +       rtsp_buffer = kmalloc(65536, GFP_KERNEL);
 825 +       if (!rtsp_buffer)
 826 +               return -ENOMEM;
 827 +
 828 +       /* If no port given, default to standard rtsp port */
 829 +       if (ports[0] == 0) {
 830 +               ports[0] = RTSP_PORT;
 831 +       }
 832 +
 833 +       for (i = 0; (i < MAX_PORTS) && ports[i]; i++) {
 834 +               hlpr = &rtsp_helpers[i];
 835 +               memset(hlpr, 0, sizeof(struct nf_conntrack_helper));
 836 +               hlpr->tuple.src.u.tcp.port = htons(ports[i]);
 837 +               hlpr->tuple.dst.protonum = IPPROTO_TCP;
 838 +               hlpr->mask.src.u.tcp.port = 0xFFFF;
 839 +               hlpr->mask.dst.protonum = 0xFF;
 840 +               hlpr->max_expected = max_outstanding;
 841 +               hlpr->timeout = setup_timeout;
 842 +               hlpr->me = THIS_MODULE;
 843 +               hlpr->help = help;
 844 +
 845 +               tmpname = &rtsp_names[i][0];
 846 +               if (ports[i] == RTSP_PORT) {
 847 +                       sprintf(tmpname, "rtsp");
 848 +               } else {
 849 +                       sprintf(tmpname, "rtsp-%d", i);
 850 +               }
 851 +               hlpr->name = tmpname;
 852 +
 853 +               DEBUGP("port #%d: %d\n", i, ports[i]);
 854 +
 855 +               ret = nf_conntrack_helper_register(hlpr);
 856 +
 857 +               if (ret) {
 858 +                       printk("nf_conntrack_rtsp: ERROR registering port %d\n", ports[i]);
 859 +                       fini();
 860 +                       return -EBUSY;
 861 +               }
 862 +               num_ports++;
 863 +       }
 864 +       return 0;
 865 +}
 866 +
 867 +module_init(init);
 868 +module_exit(fini);
 869 +
 870 +EXPORT_SYMBOL(nf_nat_rtsp_hook_expectfn);
 871 +
 872 --- linux-2.6.22.1/net/ipv4/netfilter/nf_nat_rtsp.c.orig        2007-07-30 17:35:02.000000000 +0200
 873 +++ linux-2.6.22.1/net/ipv4/netfilter/nf_nat_rtsp.c     2007-07-30 00:05:28.000000000 +0200
 874 @@ -0,0 +1,496 @@
 875 +/*
 876 + * RTSP extension for TCP NAT alteration
 877 + * (C) 2003 by Tom Marshall <tmarshall at real.com>
 878 + * based on ip_nat_irc.c
 879 + *
 880 + *      This program is free software; you can redistribute it and/or
 881 + *      modify it under the terms of the GNU General Public License
 882 + *      as published by the Free Software Foundation; either version
 883 + *      2 of the License, or (at your option) any later version.
 884 + *
 885 + * Module load syntax:
 886 + *      insmod nf_nat_rtsp.o ports=port1,port2,...port<MAX_PORTS>
 887 + *                           stunaddr=<address>
 888 + *                           destaction=[auto|strip|none]
 889 + *
 890 + * If no ports are specified, the default will be port 554 only.
 891 + *
 892 + * stunaddr specifies the address used to detect that a client is using STUN.
 893 + * If this address is seen in the destination parameter, it is assumed that
 894 + * the client has already punched a UDP hole in the firewall, so we don't
 895 + * mangle the client_port.  If none is specified, it is autodetected.  It
 896 + * only needs to be set if you have multiple levels of NAT.  It should be
 897 + * set to the external address that the STUN clients detect.  Note that in
 898 + * this case, it will not be possible for clients to use UDP with servers
 899 + * between the NATs.
 900 + *
 901 + * If no destaction is specified, auto is used.
 902 + *   destaction=auto:  strip destination parameter if it is not stunaddr.
 903 + *   destaction=strip: always strip destination parameter (not recommended).
 904 + *   destaction=none:  do not touch destination parameter (not recommended).
 905 + */
 906 +
 907 +#include <linux/module.h>
 908 +#include <net/tcp.h>
 909 +#include <net/netfilter/nf_nat_helper.h>
 910 +#include <net/netfilter/nf_nat_rule.h>
 911 +#include <linux/netfilter/nf_conntrack_rtsp.h>
 912 +#include <net/netfilter/nf_conntrack_expect.h>
 913 +
 914 +#include <linux/inet.h>
 915 +#include <linux/ctype.h>
 916 +#define NF_NEED_STRNCASECMP
 917 +#define NF_NEED_STRTOU16
 918 +#include <linux/netfilter_helpers.h>
 919 +#define NF_NEED_MIME_NEXTLINE
 920 +#include <linux/netfilter_mime.h>
 921 +
 922 +#define INFOP(fmt, args...) printk(KERN_INFO "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
 923 +#if 0
 924 +#define DEBUGP(fmt, args...) printk(KERN_DEBUG "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
 925 +#else
 926 +#define DEBUGP(fmt, args...)
 927 +#endif
 928 +
 929 +#define MAX_PORTS       8
 930 +#define DSTACT_AUTO     0
 931 +#define DSTACT_STRIP    1
 932 +#define DSTACT_NONE     2
 933 +
 934 +static char*    stunaddr = NULL;
 935 +static char*    destaction = NULL;
 936 +
 937 +static u_int32_t extip = 0;
 938 +static int       dstact = 0;
 939 +
 940 +MODULE_AUTHOR("Tom Marshall <tmarshall at real.com>");
 941 +MODULE_DESCRIPTION("RTSP network address translation module");
 942 +MODULE_LICENSE("GPL");
 943 +module_param(stunaddr, charp, 0644);
 944 +MODULE_PARM_DESC(stunaddr, "Address for detecting STUN");
 945 +module_param(destaction, charp, 0644);
 946 +MODULE_PARM_DESC(destaction, "Action for destination parameter (auto/strip/none)");
 947 +
 948 +#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
 949 +
 950 +/*** helper functions ***/
 951 +
 952 +static void
 953 +get_skb_tcpdata(struct sk_buff* skb, char** pptcpdata, uint* ptcpdatalen)
 954 +{
 955 +    struct iphdr*   iph  = ip_hdr(skb);
 956 +    struct tcphdr*  tcph = (void *)iph + ip_hdrlen(skb);
 957 +
 958 +    *pptcpdata = (char*)tcph +  tcph->doff*4;
 959 +    *ptcpdatalen = ((char*)skb_transport_header(skb) + skb->len) - *pptcpdata;
 960 +}
 961 +
 962 +/*** nat functions ***/
 963 +
 964 +/*
 965 + * Mangle the "Transport:" header:
 966 + *   - Replace all occurences of "client_port=<spec>"
 967 + *   - Handle destination parameter
 968 + *
 969 + * In:
 970 + *   ct, ctinfo = conntrack context
 971 + *   pskb       = packet
 972 + *   tranoff    = Transport header offset from TCP data
 973 + *   tranlen    = Transport header length (incl. CRLF)
 974 + *   rport_lo   = replacement low  port (host endian)
 975 + *   rport_hi   = replacement high port (host endian)
 976 + *
 977 + * Returns packet size difference.
 978 + *
 979 + * Assumes that a complete transport header is present, ending with CR or LF
 980 + */
 981 +static int
 982 +rtsp_mangle_tran(enum ip_conntrack_info ctinfo,
 983 +                 struct nf_conntrack_expect* exp,
 984 +                                                                struct ip_ct_rtsp_expect* prtspexp,
 985 +                 struct sk_buff** pskb, uint tranoff, uint tranlen)
 986 +{
 987 +    char*       ptcp;
 988 +    uint        tcplen;
 989 +    char*       ptran;
 990 +    char        rbuf1[16];      /* Replacement buffer (one port) */
 991 +    uint        rbuf1len;       /* Replacement len (one port) */
 992 +    char        rbufa[16];      /* Replacement buffer (all ports) */
 993 +    uint        rbufalen;       /* Replacement len (all ports) */
 994 +    u_int32_t   newip;
 995 +    u_int16_t   loport, hiport;
 996 +    uint        off = 0;
 997 +    uint        diff;           /* Number of bytes we removed */
 998 +
 999 +    struct nf_conn *ct = exp->master;
1000 +    struct nf_conntrack_tuple *t;
1001 +
1002 +    char    szextaddr[15+1];
1003 +    uint    extaddrlen;
1004 +    int     is_stun;
1005 +
1006 +    get_skb_tcpdata(*pskb, &ptcp, &tcplen);
1007 +    ptran = ptcp+tranoff;
1008 +
1009 +    if (tranoff+tranlen > tcplen || tcplen-tranoff < tranlen ||
1010 +        tranlen < 10 || !iseol(ptran[tranlen-1]) ||
1011 +        nf_strncasecmp(ptran, "Transport:", 10) != 0)
1012 +    {
1013 +        INFOP("sanity check failed\n");
1014 +        return 0;
1015 +    }
1016 +    off += 10;
1017 +    SKIP_WSPACE(ptcp+tranoff, tranlen, off);
1018 +
1019 +    newip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip;
1020 +    t = &exp->tuple;
1021 +    t->dst.u3.ip = newip;
1022 +
1023 +    extaddrlen = extip ? sprintf(szextaddr, "%u.%u.%u.%u", NIPQUAD(extip))
1024 +                       : sprintf(szextaddr, "%u.%u.%u.%u", NIPQUAD(newip));
1025 +    DEBUGP("stunaddr=%s (%s)\n", szextaddr, (extip?"forced":"auto"));
1026 +
1027 +    rbuf1len = rbufalen = 0;
1028 +    switch (prtspexp->pbtype)
1029 +    {
1030 +    case pb_single:
1031 +        for (loport = prtspexp->loport; loport != 0; loport++) /* XXX: improper wrap? */
1032 +        {
1033 +            t->dst.u.udp.port = htons(loport);
1034 +            if (nf_conntrack_expect_related(exp) == 0)
1035 +            {
1036 +                DEBUGP("using port %hu\n", loport);
1037 +                break;
1038 +            }
1039 +        }
1040 +        if (loport != 0)
1041 +        {
1042 +            rbuf1len = sprintf(rbuf1, "%hu", loport);
1043 +            rbufalen = sprintf(rbufa, "%hu", loport);
1044 +        }
1045 +        break;
1046 +    case pb_range:
1047 +        for (loport = prtspexp->loport; loport != 0; loport += 2) /* XXX: improper wrap? */
1048 +        {
1049 +            t->dst.u.udp.port = htons(loport);
1050 +            if (nf_conntrack_expect_related(exp) == 0)
1051 +            {
1052 +                hiport = loport + ~exp->mask.dst.u.udp.port;
1053 +                DEBUGP("using ports %hu-%hu\n", loport, hiport);
1054 +                break;
1055 +            }
1056 +        }
1057 +        if (loport != 0)
1058 +        {
1059 +            rbuf1len = sprintf(rbuf1, "%hu", loport);
1060 +            rbufalen = sprintf(rbufa, "%hu-%hu", loport, loport+1);
1061 +        }
1062 +        break;
1063 +    case pb_discon:
1064 +        for (loport = prtspexp->loport; loport != 0; loport++) /* XXX: improper wrap? */
1065 +        {
1066 +            t->dst.u.udp.port = htons(loport);
1067 +            if (nf_conntrack_expect_related(exp) == 0)
1068 +            {
1069 +                DEBUGP("using port %hu (1 of 2)\n", loport);
1070 +                break;
1071 +            }
1072 +        }
1073 +        for (hiport = prtspexp->hiport; hiport != 0; hiport++) /* XXX: improper wrap? */
1074 +        {
1075 +            t->dst.u.udp.port = htons(hiport);
1076 +            if (nf_conntrack_expect_related(exp) == 0)
1077 +            {
1078 +                DEBUGP("using port %hu (2 of 2)\n", hiport);
1079 +                break;
1080 +            }
1081 +        }
1082 +        if (loport != 0 && hiport != 0)
1083 +        {
1084 +            rbuf1len = sprintf(rbuf1, "%hu", loport);
1085 +            if (hiport == loport+1)
1086 +            {
1087 +                rbufalen = sprintf(rbufa, "%hu-%hu", loport, hiport);
1088 +            }
1089 +            else
1090 +            {
1091 +                rbufalen = sprintf(rbufa, "%hu/%hu", loport, hiport);
1092 +            }
1093 +        }
1094 +        break;
1095 +    }
1096 +
1097 +    if (rbuf1len == 0)
1098 +    {
1099 +        return 0;   /* cannot get replacement port(s) */
1100 +    }
1101 +
1102 +    /* Transport: tran;field;field=val,tran;field;field=val,... */
1103 +    while (off < tranlen)
1104 +    {
1105 +        uint        saveoff;
1106 +        const char* pparamend;
1107 +        uint        nextparamoff;
1108 +
1109 +        pparamend = memchr(ptran+off, ',', tranlen-off);
1110 +        pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
1111 +        nextparamoff = pparamend-ptcp;
1112 +
1113 +        /*
1114 +         * We pass over each param twice.  On the first pass, we look for a
1115 +         * destination= field.  It is handled by the security policy.  If it
1116 +         * is present, allowed, and equal to our external address, we assume
1117 +         * that STUN is being used and we leave the client_port= field alone.
1118 +         */
1119 +        is_stun = 0;
1120 +        saveoff = off;
1121 +        while (off < nextparamoff)
1122 +        {
1123 +            const char* pfieldend;
1124 +            uint        nextfieldoff;
1125 +
1126 +            pfieldend = memchr(ptran+off, ';', nextparamoff-off);
1127 +            nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
1128 +
1129 +            if (dstact != DSTACT_NONE && strncmp(ptran+off, "destination=", 12) == 0)
1130 +            {
1131 +                if (strncmp(ptran+off+12, szextaddr, extaddrlen) == 0)
1132 +                {
1133 +                    is_stun = 1;
1134 +                }
1135 +                if (dstact == DSTACT_STRIP || (dstact == DSTACT_AUTO && !is_stun))
1136 +                {
1137 +                    diff = nextfieldoff-off;
1138 +                    if (!nf_nat_mangle_tcp_packet(pskb, ct, ctinfo,
1139 +                                                         off, diff, NULL, 0))
1140 +                    {
1141 +                        /* mangle failed, all we can do is bail */
1142 +                       nf_conntrack_unexpect_related(exp);
1143 +                        return 0;
1144 +                    }
1145 +                    get_skb_tcpdata(*pskb, &ptcp, &tcplen);
1146 +                    ptran = ptcp+tranoff;
1147 +                    tranlen -= diff;
1148 +                    nextparamoff -= diff;
1149 +                    nextfieldoff -= diff;
1150 +                }
1151 +            }
1152 +
1153 +            off = nextfieldoff;
1154 +        }
1155 +        if (is_stun)
1156 +        {
1157 +            continue;
1158 +        }
1159 +        off = saveoff;
1160 +        while (off < nextparamoff)
1161 +        {
1162 +            const char* pfieldend;
1163 +            uint        nextfieldoff;
1164 +
1165 +            pfieldend = memchr(ptran+off, ';', nextparamoff-off);
1166 +            nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
1167 +
1168 +            if (strncmp(ptran+off, "client_port=", 12) == 0)
1169 +            {
1170 +                u_int16_t   port;
1171 +                uint        numlen;
1172 +                uint        origoff;
1173 +                uint        origlen;
1174 +                char*       rbuf    = rbuf1;
1175 +                uint        rbuflen = rbuf1len;
1176 +
1177 +                off += 12;
1178 +                origoff = (ptran-ptcp)+off;
1179 +                origlen = 0;
1180 +                numlen = nf_strtou16(ptran+off, &port);
1181 +                off += numlen;
1182 +                origlen += numlen;
1183 +                if (port != prtspexp->loport)
1184 +                {
1185 +                    DEBUGP("multiple ports found, port %hu ignored\n", port);
1186 +                }
1187 +                else
1188 +                {
1189 +                    if (ptran[off] == '-' || ptran[off] == '/')
1190 +                    {
1191 +                        off++;
1192 +                        origlen++;
1193 +                        numlen = nf_strtou16(ptran+off, &port);
1194 +                        off += numlen;
1195 +                        origlen += numlen;
1196 +                        rbuf = rbufa;
1197 +                        rbuflen = rbufalen;
1198 +                    }
1199 +
1200 +                    /*
1201 +                     * note we cannot just memcpy() if the sizes are the same.
1202 +                     * the mangle function does skb resizing, checks for a
1203 +                     * cloned skb, and updates the checksums.
1204 +                     *
1205 +                     * parameter 4 below is offset from start of tcp data.
1206 +                     */
1207 +                    diff = origlen-rbuflen;
1208 +                    if (!nf_nat_mangle_tcp_packet(pskb, ct, ctinfo,
1209 +                                              origoff, origlen, rbuf, rbuflen))
1210 +                    {
1211 +                        /* mangle failed, all we can do is bail */
1212 +                       nf_conntrack_unexpect_related(exp);
1213 +                        return 0;
1214 +                    }
1215 +                    get_skb_tcpdata(*pskb, &ptcp, &tcplen);
1216 +                    ptran = ptcp+tranoff;
1217 +                    tranlen -= diff;
1218 +                    nextparamoff -= diff;
1219 +                    nextfieldoff -= diff;
1220 +                }
1221 +            }
1222 +
1223 +            off = nextfieldoff;
1224 +        }
1225 +
1226 +        off = nextparamoff;
1227 +    }
1228 +
1229 +    return 1;
1230 +}
1231 +
1232 +static uint
1233 +help_out(struct sk_buff **pskb, enum ip_conntrack_info ctinfo,
1234 +        unsigned int matchoff, unsigned int matchlen, struct ip_ct_rtsp_expect* prtspexp,
1235 +        struct nf_conntrack_expect* exp)
1236 +{
1237 +    char*   ptcp;
1238 +    uint    tcplen;
1239 +    uint    hdrsoff;
1240 +    uint    hdrslen;
1241 +    uint    lineoff;
1242 +    uint    linelen;
1243 +    uint    off;
1244 +
1245 +    //struct iphdr* iph = (struct iphdr*)(*pskb)->nh.iph;
1246 +    //struct tcphdr* tcph = (struct tcphdr*)((void*)iph + iph->ihl*4);
1247 +
1248 +    get_skb_tcpdata(*pskb, &ptcp, &tcplen);
1249 +    hdrsoff = matchoff;//exp->seq - ntohl(tcph->seq);
1250 +    hdrslen = matchlen;
1251 +    off = hdrsoff;
1252 +    DEBUGP("NAT rtsp help_out\n");
1253 +
1254 +    while (nf_mime_nextline(ptcp, hdrsoff+hdrslen, &off, &lineoff, &linelen))
1255 +    {
1256 +        if (linelen == 0)
1257 +        {
1258 +            break;
1259 +        }
1260 +        if (off > hdrsoff+hdrslen)
1261 +        {
1262 +            INFOP("!! overrun !!");
1263 +            break;
1264 +        }
1265 +        DEBUGP("hdr: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
1266 +
1267 +        if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0)
1268 +        {
1269 +            uint oldtcplen = tcplen;
1270 +           DEBUGP("hdr: Transport\n");
1271 +            if (!rtsp_mangle_tran(ctinfo, exp, prtspexp, pskb, lineoff, linelen))
1272 +            {
1273 +               DEBUGP("hdr: Transport mangle failed");
1274 +                break;
1275 +            }
1276 +            get_skb_tcpdata(*pskb, &ptcp, &tcplen);
1277 +            hdrslen -= (oldtcplen-tcplen);
1278 +            off -= (oldtcplen-tcplen);
1279 +            lineoff -= (oldtcplen-tcplen);
1280 +            linelen -= (oldtcplen-tcplen);
1281 +            DEBUGP("rep: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
1282 +        }
1283 +    }
1284 +
1285 +    return NF_ACCEPT;
1286 +}
1287 +
1288 +static unsigned int
1289 +help(struct sk_buff **pskb, enum ip_conntrack_info ctinfo,
1290 +     unsigned int matchoff, unsigned int matchlen, struct ip_ct_rtsp_expect* prtspexp,
1291 +     struct nf_conntrack_expect* exp)
1292 +{
1293 +    int dir = CTINFO2DIR(ctinfo);
1294 +    int rc = NF_ACCEPT;
1295 +
1296 +    switch (dir)
1297 +    {
1298 +    case IP_CT_DIR_ORIGINAL:
1299 +        rc = help_out(pskb, ctinfo, matchoff, matchlen, prtspexp, exp);
1300 +        break;
1301 +    case IP_CT_DIR_REPLY:
1302 +       DEBUGP("unmangle ! %u\n", ctinfo);
1303 +       /* XXX: unmangle */
1304 +       rc = NF_ACCEPT;
1305 +        break;
1306 +    }
1307 +    //UNLOCK_BH(&ip_rtsp_lock);
1308 +
1309 +    return rc;
1310 +}
1311 +
1312 +static void expected(struct nf_conn* ct, struct nf_conntrack_expect *exp)
1313 +{
1314 +    struct nf_nat_multi_range_compat mr;
1315 +    u_int32_t newdstip, newsrcip, newip;
1316 +
1317 +    struct nf_conn *master = ct->master;
1318 +
1319 +    newdstip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip;
1320 +    newsrcip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip;
1321 +    //FIXME (how to port that ?)
1322 +    //code from 2.4 : newip = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC) ? newsrcip : newdstip;
1323 +    newip = newdstip;
1324 +
1325 +    DEBUGP("newsrcip=%u.%u.%u.%u, newdstip=%u.%u.%u.%u, newip=%u.%u.%u.%u\n",
1326 +           NIPQUAD(newsrcip), NIPQUAD(newdstip), NIPQUAD(newip));
1327 +
1328 +    mr.rangesize = 1;
1329 +    // We don't want to manip the per-protocol, just the IPs.
1330 +    mr.range[0].flags = IP_NAT_RANGE_MAP_IPS;
1331 +    mr.range[0].min_ip = mr.range[0].max_ip = newip;
1332 +
1333 +    nf_nat_setup_info(ct, &mr.range[0], NF_IP_PRE_ROUTING);
1334 +}
1335 +
1336 +
1337 +static void __exit fini(void)
1338 +{
1339 +       nf_nat_rtsp_hook = NULL;
1340 +        nf_nat_rtsp_hook_expectfn = NULL;
1341 +       synchronize_net();
1342 +}
1343 +
1344 +static int __init init(void)
1345 +{
1346 +       printk("nf_nat_rtsp v" IP_NF_RTSP_VERSION " loading\n");
1347 +
1348 +       BUG_ON(nf_nat_rtsp_hook);
1349 +       nf_nat_rtsp_hook = help;
1350 +        nf_nat_rtsp_hook_expectfn = &expected;
1351 +
1352 +       if (stunaddr != NULL)
1353 +               extip = in_aton(stunaddr);
1354 +
1355 +       if (destaction != NULL) {
1356 +               if (strcmp(destaction, "auto") == 0)
1357 +                       dstact = DSTACT_AUTO;
1358 +
1359 +               if (strcmp(destaction, "strip") == 0)
1360 +                       dstact = DSTACT_STRIP;
1361 +
1362 +               if (strcmp(destaction, "none") == 0)
1363 +                       dstact = DSTACT_NONE;
1364 +       }
1365 +
1366 +       return 0;
1367 +}
1368 +
1369 +module_init(init);
1370 +module_exit(fini);