[kernel] generic-2.4: refresh patches
[openwrt/svn-archive/archive.git] / target / linux / generic-2.4 / patches / 614-netfilter_nat_rtsp.patch
1 --- a/net/ipv4/netfilter/Config.in
2 +++ b/net/ipv4/netfilter/Config.in
3 @@ -16,6 +16,7 @@ if [ "$CONFIG_IP_NF_CONNTRACK" != "n" ];
4 dep_tristate ' GRE protocol support' CONFIG_IP_NF_CT_PROTO_GRE $CONFIG_IP_NF_CONNTRACK
5 dep_tristate ' PPTP protocol support' CONFIG_IP_NF_PPTP $CONFIG_IP_NF_CT_PROTO_GRE
6 dep_tristate ' H.323 (netmeeting) support' CONFIG_IP_NF_H323 $CONFIG_IP_NF_CONNTRACK
7 + dep_tristate ' RTSP protocol support' CONFIG_IP_NF_RTSP $CONFIG_IP_NF_CONNTRACK
8 fi
9
10 if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
11 @@ -118,6 +119,13 @@ if [ "$CONFIG_IP_NF_IPTABLES" != "n" ];
12 define_tristate CONFIG_IP_NF_NAT_H323 $CONFIG_IP_NF_NAT
13 fi
14 fi
15 + if [ "$CONFIG_IP_NF_RTSP" = "m" ]; then
16 + define_tristate CONFIG_IP_NF_NAT_RTSP m
17 + else
18 + if [ "$CONFIG_IP_NF_RTSP" = "y" ]; then
19 + define_tristate CONFIG_IP_NF_NAT_RTSP $CONFIG_IP_NF_NAT
20 + fi
21 + fi
22 if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
23 dep_tristate ' Basic SNMP-ALG support (EXPERIMENTAL)' CONFIG_IP_NF_NAT_SNMP_BASIC $CONFIG_IP_NF_NAT
24 fi
25 --- a/net/ipv4/netfilter/Makefile
26 +++ b/net/ipv4/netfilter/Makefile
27 @@ -57,6 +57,11 @@ obj-$(CONFIG_IP_NF_H323) += ip_conntrack
28 ifdef CONFIG_IP_NF_NAT_H323
29 export-objs += ip_conntrack_h323.o
30 endif
31 +obj-$(CONFIG_IP_NF_RTSP) += ip_conntrack_rtsp.o
32 +ifdef CONFIG_IP_NF_NAT_RTSP
33 + export-objs += ip_conntrack_rtsp.o
34 +endif
35 +
36
37
38 # NAT helpers
39 @@ -67,6 +72,7 @@ obj-$(CONFIG_IP_NF_NAT_IRC) += ip_nat_ir
40 obj-$(CONFIG_IP_NF_NAT_PROTO_GRE) += ip_nat_proto_gre.o
41 obj-$(CONFIG_IP_NF_NAT_PPTP) += ip_nat_pptp.o
42 obj-$(CONFIG_IP_NF_NAT_H323) += ip_nat_h323.o
43 +obj-$(CONFIG_IP_NF_NAT_RTSP) += ip_nat_rtsp.o
44
45 # generic IP tables
46 obj-$(CONFIG_IP_NF_IPTABLES) += ip_tables.o
47 --- /dev/null
48 +++ b/net/ipv4/netfilter/ip_conntrack_rtsp.c
49 @@ -0,0 +1,507 @@
50 +/*
51 + * RTSP extension for IP connection tracking
52 + * (C) 2003 by Tom Marshall <tmarshall@real.com>
53 + * based on ip_conntrack_irc.c
54 + *
55 + * This program is free software; you can redistribute it and/or
56 + * modify it under the terms of the GNU General Public License
57 + * as published by the Free Software Foundation; either version
58 + * 2 of the License, or (at your option) any later version.
59 + *
60 + * Module load syntax:
61 + * insmod ip_conntrack_rtsp.o ports=port1,port2,...port<MAX_PORTS>
62 + * max_outstanding=n setup_timeout=secs
63 + *
64 + * If no ports are specified, the default will be port 554.
65 + *
66 + * With max_outstanding you can define the maximum number of not yet
67 + * answered SETUP requests per RTSP session (default 8).
68 + * With setup_timeout you can specify how long the system waits for
69 + * an expected data channel (default 300 seconds).
70 + */
71 +
72 +#include <linux/config.h>
73 +#include <linux/module.h>
74 +#include <linux/netfilter.h>
75 +#include <linux/ip.h>
76 +#include <net/checksum.h>
77 +#include <net/tcp.h>
78 +
79 +#include <linux/netfilter_ipv4/lockhelp.h>
80 +#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
81 +#include <linux/netfilter_ipv4/ip_conntrack_rtsp.h>
82 +
83 +#include <linux/ctype.h>
84 +#define NF_NEED_STRNCASECMP
85 +#define NF_NEED_STRTOU16
86 +#define NF_NEED_STRTOU32
87 +#define NF_NEED_NEXTLINE
88 +#include <linux/netfilter_helpers.h>
89 +#define NF_NEED_MIME_NEXTLINE
90 +#include <linux/netfilter_mime.h>
91 +
92 +#define MAX_SIMUL_SETUP 8 /* XXX: use max_outstanding */
93 +
94 +#define INFOP(fmt, args...) printk(KERN_INFO "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
95 +#ifdef IP_NF_RTSP_DEBUG
96 +#define DEBUGP(fmt, args...) printk(KERN_DEBUG "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
97 +#else
98 +#define DEBUGP(fmt, args...)
99 +#endif
100 +
101 +#define MAX_PORTS 8
102 +static int ports[MAX_PORTS];
103 +static int num_ports = 0;
104 +static int max_outstanding = 8;
105 +static unsigned int setup_timeout = 300;
106 +
107 +MODULE_AUTHOR("Tom Marshall <tmarshall@real.com>");
108 +MODULE_DESCRIPTION("RTSP connection tracking module");
109 +MODULE_LICENSE("GPL");
110 +#ifdef MODULE_PARM
111 +MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_PORTS) "i");
112 +MODULE_PARM_DESC(ports, "port numbers of RTSP servers");
113 +MODULE_PARM(max_outstanding, "i");
114 +MODULE_PARM_DESC(max_outstanding, "max number of outstanding SETUP requests per RTSP session");
115 +MODULE_PARM(setup_timeout, "i");
116 +MODULE_PARM_DESC(setup_timeout, "timeout on for unestablished data channels");
117 +#endif
118 +
119 +DECLARE_LOCK(ip_rtsp_lock);
120 +struct module* ip_conntrack_rtsp = THIS_MODULE;
121 +
122 +/*
123 + * Max mappings we will allow for one RTSP connection (for RTP, the number
124 + * of allocated ports is twice this value). Note that SMIL burns a lot of
125 + * ports so keep this reasonably high. If this is too low, you will see a
126 + * lot of "no free client map entries" messages.
127 + */
128 +#define MAX_PORT_MAPS 16
129 +
130 +/*** default port list was here in the masq code: 554, 3030, 4040 ***/
131 +
132 +#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
133 +
134 +/*
135 + * Parse an RTSP packet.
136 + *
137 + * Returns zero if parsing failed.
138 + *
139 + * Parameters:
140 + * IN ptcp tcp data pointer
141 + * IN tcplen tcp data len
142 + * IN/OUT ptcpoff points to current tcp offset
143 + * OUT phdrsoff set to offset of rtsp headers
144 + * OUT phdrslen set to length of rtsp headers
145 + * OUT pcseqoff set to offset of CSeq header
146 + * OUT pcseqlen set to length of CSeq header
147 + */
148 +static int
149 +rtsp_parse_message(char* ptcp, uint tcplen, uint* ptcpoff,
150 + uint* phdrsoff, uint* phdrslen,
151 + uint* pcseqoff, uint* pcseqlen)
152 +{
153 + uint entitylen = 0;
154 + uint lineoff;
155 + uint linelen;
156 +
157 + if (!nf_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
158 + {
159 + return 0;
160 + }
161 +
162 + *phdrsoff = *ptcpoff;
163 + while (nf_mime_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
164 + {
165 + if (linelen == 0)
166 + {
167 + if (entitylen > 0)
168 + {
169 + *ptcpoff += min(entitylen, tcplen - *ptcpoff);
170 + }
171 + break;
172 + }
173 + if (lineoff+linelen > tcplen)
174 + {
175 + INFOP("!! overrun !!\n");
176 + break;
177 + }
178 +
179 + if (nf_strncasecmp(ptcp+lineoff, "CSeq:", 5) == 0)
180 + {
181 + *pcseqoff = lineoff;
182 + *pcseqlen = linelen;
183 + }
184 + if (nf_strncasecmp(ptcp+lineoff, "Content-Length:", 15) == 0)
185 + {
186 + uint off = lineoff+15;
187 + SKIP_WSPACE(ptcp+lineoff, linelen, off);
188 + nf_strtou32(ptcp+off, &entitylen);
189 + }
190 + }
191 + *phdrslen = (*ptcpoff) - (*phdrsoff);
192 +
193 + return 1;
194 +}
195 +
196 +/*
197 + * Find lo/hi client ports (if any) in transport header
198 + * In:
199 + * ptcp, tcplen = packet
200 + * tranoff, tranlen = buffer to search
201 + *
202 + * Out:
203 + * pport_lo, pport_hi = lo/hi ports (host endian)
204 + *
205 + * Returns nonzero if any client ports found
206 + *
207 + * Note: it is valid (and expected) for the client to request multiple
208 + * transports, so we need to parse the entire line.
209 + */
210 +static int
211 +rtsp_parse_transport(char* ptran, uint tranlen,
212 + struct ip_ct_rtsp_expect* prtspexp)
213 +{
214 + int rc = 0;
215 + uint off = 0;
216 +
217 + if (tranlen < 10 || !iseol(ptran[tranlen-1]) ||
218 + nf_strncasecmp(ptran, "Transport:", 10) != 0)
219 + {
220 + INFOP("sanity check failed\n");
221 + return 0;
222 + }
223 + DEBUGP("tran='%.*s'\n", (int)tranlen, ptran);
224 + off += 10;
225 + SKIP_WSPACE(ptran, tranlen, off);
226 +
227 + /* Transport: tran;field;field=val,tran;field;field=val,... */
228 + while (off < tranlen)
229 + {
230 + const char* pparamend;
231 + uint nextparamoff;
232 +
233 + pparamend = memchr(ptran+off, ',', tranlen-off);
234 + pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
235 + nextparamoff = pparamend-ptran;
236 +
237 + while (off < nextparamoff)
238 + {
239 + const char* pfieldend;
240 + uint nextfieldoff;
241 +
242 + pfieldend = memchr(ptran+off, ';', nextparamoff-off);
243 + nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
244 +
245 + if (strncmp(ptran+off, "client_port=", 12) == 0)
246 + {
247 + u_int16_t port;
248 + uint numlen;
249 +
250 + off += 12;
251 + numlen = nf_strtou16(ptran+off, &port);
252 + off += numlen;
253 + if (prtspexp->loport != 0 && prtspexp->loport != port)
254 + {
255 + DEBUGP("multiple ports found, port %hu ignored\n", port);
256 + }
257 + else
258 + {
259 + prtspexp->loport = prtspexp->hiport = port;
260 + if (ptran[off] == '-')
261 + {
262 + off++;
263 + numlen = nf_strtou16(ptran+off, &port);
264 + off += numlen;
265 + prtspexp->pbtype = pb_range;
266 + prtspexp->hiport = port;
267 +
268 + // If we have a range, assume rtp:
269 + // loport must be even, hiport must be loport+1
270 + if ((prtspexp->loport & 0x0001) != 0 ||
271 + prtspexp->hiport != prtspexp->loport+1)
272 + {
273 + DEBUGP("incorrect range: %hu-%hu, correcting\n",
274 + prtspexp->loport, prtspexp->hiport);
275 + prtspexp->loport &= 0xfffe;
276 + prtspexp->hiport = prtspexp->loport+1;
277 + }
278 + }
279 + else if (ptran[off] == '/')
280 + {
281 + off++;
282 + numlen = nf_strtou16(ptran+off, &port);
283 + off += numlen;
284 + prtspexp->pbtype = pb_discon;
285 + prtspexp->hiport = port;
286 + }
287 + rc = 1;
288 + }
289 + }
290 +
291 + /*
292 + * Note we don't look for the destination parameter here.
293 + * If we are using NAT, the NAT module will handle it. If not,
294 + * and the client is sending packets elsewhere, the expectation
295 + * will quietly time out.
296 + */
297 +
298 + off = nextfieldoff;
299 + }
300 +
301 + off = nextparamoff;
302 + }
303 +
304 + return rc;
305 +}
306 +
307 +/*** conntrack functions ***/
308 +
309 +/* outbound packet: client->server */
310 +static int
311 +help_out(const struct iphdr* iph, size_t pktlen,
312 + struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
313 +{
314 + int dir = CTINFO2DIR(ctinfo); /* = IP_CT_DIR_ORIGINAL */
315 + struct tcphdr* tcph = (void*)iph + iph->ihl * 4;
316 + uint tcplen = pktlen - iph->ihl * 4;
317 + char* pdata = (char*)tcph + tcph->doff * 4;
318 + uint datalen = tcplen - tcph->doff * 4;
319 + uint dataoff = 0;
320 +
321 + struct ip_conntrack_expect exp;
322 +
323 + while (dataoff < datalen)
324 + {
325 + uint cmdoff = dataoff;
326 + uint hdrsoff = 0;
327 + uint hdrslen = 0;
328 + uint cseqoff = 0;
329 + uint cseqlen = 0;
330 + uint lineoff = 0;
331 + uint linelen = 0;
332 + uint off;
333 + int rc;
334 +
335 + if (!rtsp_parse_message(pdata, datalen, &dataoff,
336 + &hdrsoff, &hdrslen,
337 + &cseqoff, &cseqlen))
338 + {
339 + break; /* not a valid message */
340 + }
341 +
342 + if (strncmp(pdata+cmdoff, "SETUP ", 6) != 0)
343 + {
344 + continue; /* not a SETUP message */
345 + }
346 + DEBUGP("found a setup message\n");
347 +
348 + memset(&exp, 0, sizeof(exp));
349 +
350 + off = 0;
351 + while (nf_mime_nextline(pdata+hdrsoff, hdrslen, &off,
352 + &lineoff, &linelen))
353 + {
354 + if (linelen == 0)
355 + {
356 + break;
357 + }
358 + if (off > hdrsoff+hdrslen)
359 + {
360 + INFOP("!! overrun !!");
361 + break;
362 + }
363 +
364 + if (nf_strncasecmp(pdata+hdrsoff+lineoff, "Transport:", 10) == 0)
365 + {
366 + rtsp_parse_transport(pdata+hdrsoff+lineoff, linelen,
367 + &exp.help.exp_rtsp_info);
368 + }
369 + }
370 +
371 + if (exp.help.exp_rtsp_info.loport == 0)
372 + {
373 + DEBUGP("no udp transports found\n");
374 + continue; /* no udp transports found */
375 + }
376 +
377 + DEBUGP("udp transport found, ports=(%d,%hu,%hu)\n",
378 + (int)exp.help.exp_rtsp_info.pbtype,
379 + exp.help.exp_rtsp_info.loport,
380 + exp.help.exp_rtsp_info.hiport);
381 +
382 + LOCK_BH(&ip_rtsp_lock);
383 + exp.seq = ntohl(tcph->seq) + hdrsoff; /* mark all the headers */
384 + exp.help.exp_rtsp_info.len = hdrslen;
385 +
386 + exp.tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
387 + exp.mask.src.ip = 0xffffffff;
388 + exp.tuple.dst.ip = ct->tuplehash[dir].tuple.src.ip;
389 + exp.mask.dst.ip = 0xffffffff;
390 + exp.tuple.dst.u.udp.port = exp.help.exp_rtsp_info.loport;
391 + exp.mask.dst.u.udp.port = (exp.help.exp_rtsp_info.pbtype == pb_range) ? 0xfffe : 0xffff;
392 + exp.tuple.dst.protonum = IPPROTO_UDP;
393 + exp.mask.dst.protonum = 0xffff;
394 +
395 + DEBUGP("expect_related %u.%u.%u.%u:%u-%u.%u.%u.%u:%u\n",
396 + NIPQUAD(exp.tuple.src.ip),
397 + ntohs(exp.tuple.src.u.tcp.port),
398 + NIPQUAD(exp.tuple.dst.ip),
399 + ntohs(exp.tuple.dst.u.tcp.port));
400 +
401 + /* pass the request off to the nat helper */
402 + rc = ip_conntrack_expect_related(ct, &exp);
403 + UNLOCK_BH(&ip_rtsp_lock);
404 + if (rc == 0)
405 + {
406 + DEBUGP("ip_conntrack_expect_related succeeded\n");
407 + }
408 + else
409 + {
410 + INFOP("ip_conntrack_expect_related failed (%d)\n", rc);
411 + }
412 + }
413 +
414 + return NF_ACCEPT;
415 +}
416 +
417 +/* inbound packet: server->client */
418 +static int
419 +help_in(const struct iphdr* iph, size_t pktlen,
420 + struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
421 +{
422 + return NF_ACCEPT;
423 +}
424 +
425 +static int
426 +help(const struct iphdr* iph, size_t pktlen,
427 + struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
428 +{
429 + /* tcplen not negative guarenteed by ip_conntrack_tcp.c */
430 + struct tcphdr* tcph = (void*)iph + iph->ihl * 4;
431 + u_int32_t tcplen = pktlen - iph->ihl * 4;
432 +
433 + /* Until there's been traffic both ways, don't look in packets. */
434 + if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY)
435 + {
436 + DEBUGP("conntrackinfo = %u\n", ctinfo);
437 + return NF_ACCEPT;
438 + }
439 +
440 + /* Not whole TCP header? */
441 + if (tcplen < sizeof(struct tcphdr) || tcplen < tcph->doff * 4)
442 + {
443 + DEBUGP("tcplen = %u\n", (unsigned)tcplen);
444 + return NF_ACCEPT;
445 + }
446 +
447 + /* Checksum invalid? Ignore. */
448 + /* FIXME: Source route IP option packets --RR */
449 + if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
450 + csum_partial((char*)tcph, tcplen, 0)))
451 + {
452 + DEBUGP("bad csum: %p %u %u.%u.%u.%u %u.%u.%u.%u\n",
453 + tcph, tcplen, NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
454 + return NF_ACCEPT;
455 + }
456 +
457 + switch (CTINFO2DIR(ctinfo))
458 + {
459 + case IP_CT_DIR_ORIGINAL:
460 + help_out(iph, pktlen, ct, ctinfo);
461 + break;
462 + case IP_CT_DIR_REPLY:
463 + help_in(iph, pktlen, ct, ctinfo);
464 + break;
465 + }
466 +
467 + return NF_ACCEPT;
468 +}
469 +
470 +static struct ip_conntrack_helper rtsp_helpers[MAX_PORTS];
471 +static char rtsp_names[MAX_PORTS][10];
472 +
473 +/* This function is intentionally _NOT_ defined as __exit */
474 +static void
475 +fini(void)
476 +{
477 + int i;
478 + for (i = 0; i < num_ports; i++)
479 + {
480 + DEBUGP("unregistering port %d\n", ports[i]);
481 + ip_conntrack_helper_unregister(&rtsp_helpers[i]);
482 + }
483 +}
484 +
485 +static int __init
486 +init(void)
487 +{
488 + int i, ret;
489 + struct ip_conntrack_helper *hlpr;
490 + char *tmpname;
491 +
492 + printk("ip_conntrack_rtsp v" IP_NF_RTSP_VERSION " loading\n");
493 +
494 + if (max_outstanding < 1)
495 + {
496 + printk("ip_conntrack_rtsp: max_outstanding must be a positive integer\n");
497 + return -EBUSY;
498 + }
499 + if (setup_timeout < 0)
500 + {
501 + printk("ip_conntrack_rtsp: setup_timeout must be a positive integer\n");
502 + return -EBUSY;
503 + }
504 +
505 + /* If no port given, default to standard rtsp port */
506 + if (ports[0] == 0)
507 + {
508 + ports[0] = RTSP_PORT;
509 + }
510 +
511 + for (i = 0; (i < MAX_PORTS) && ports[i]; i++)
512 + {
513 + hlpr = &rtsp_helpers[i];
514 + memset(hlpr, 0, sizeof(struct ip_conntrack_helper));
515 + hlpr->tuple.src.u.tcp.port = htons(ports[i]);
516 + hlpr->tuple.dst.protonum = IPPROTO_TCP;
517 + hlpr->mask.src.u.tcp.port = 0xFFFF;
518 + hlpr->mask.dst.protonum = 0xFFFF;
519 + hlpr->max_expected = max_outstanding;
520 + hlpr->timeout = setup_timeout;
521 + hlpr->flags = IP_CT_HELPER_F_REUSE_EXPECT;
522 + hlpr->me = ip_conntrack_rtsp;
523 + hlpr->help = help;
524 +
525 + tmpname = &rtsp_names[i][0];
526 + if (ports[i] == RTSP_PORT)
527 + {
528 + sprintf(tmpname, "rtsp");
529 + }
530 + else
531 + {
532 + sprintf(tmpname, "rtsp-%d", i);
533 + }
534 + hlpr->name = tmpname;
535 +
536 + DEBUGP("port #%d: %d\n", i, ports[i]);
537 +
538 + ret = ip_conntrack_helper_register(hlpr);
539 +
540 + if (ret)
541 + {
542 + printk("ip_conntrack_rtsp: ERROR registering port %d\n", ports[i]);
543 + fini();
544 + return -EBUSY;
545 + }
546 + num_ports++;
547 + }
548 + return 0;
549 +}
550 +
551 +#ifdef CONFIG_IP_NF_NAT_NEEDED
552 +EXPORT_SYMBOL(ip_rtsp_lock);
553 +#endif
554 +
555 +module_init(init);
556 +module_exit(fini);
557 --- /dev/null
558 +++ b/net/ipv4/netfilter/ip_nat_rtsp.c
559 @@ -0,0 +1,621 @@
560 +/*
561 + * RTSP extension for TCP NAT alteration
562 + * (C) 2003 by Tom Marshall <tmarshall@real.com>
563 + * based on ip_nat_irc.c
564 + *
565 + * This program is free software; you can redistribute it and/or
566 + * modify it under the terms of the GNU General Public License
567 + * as published by the Free Software Foundation; either version
568 + * 2 of the License, or (at your option) any later version.
569 + *
570 + * Module load syntax:
571 + * insmod ip_nat_rtsp.o ports=port1,port2,...port<MAX_PORTS>
572 + * stunaddr=<address>
573 + * destaction=[auto|strip|none]
574 + *
575 + * If no ports are specified, the default will be port 554 only.
576 + *
577 + * stunaddr specifies the address used to detect that a client is using STUN.
578 + * If this address is seen in the destination parameter, it is assumed that
579 + * the client has already punched a UDP hole in the firewall, so we don't
580 + * mangle the client_port. If none is specified, it is autodetected. It
581 + * only needs to be set if you have multiple levels of NAT. It should be
582 + * set to the external address that the STUN clients detect. Note that in
583 + * this case, it will not be possible for clients to use UDP with servers
584 + * between the NATs.
585 + *
586 + * If no destaction is specified, auto is used.
587 + * destaction=auto: strip destination parameter if it is not stunaddr.
588 + * destaction=strip: always strip destination parameter (not recommended).
589 + * destaction=none: do not touch destination parameter (not recommended).
590 + */
591 +
592 +#include <linux/module.h>
593 +#include <linux/netfilter_ipv4.h>
594 +#include <linux/ip.h>
595 +#include <linux/tcp.h>
596 +#include <linux/kernel.h>
597 +#include <net/tcp.h>
598 +#include <linux/netfilter_ipv4/ip_nat.h>
599 +#include <linux/netfilter_ipv4/ip_nat_helper.h>
600 +#include <linux/netfilter_ipv4/ip_nat_rule.h>
601 +#include <linux/netfilter_ipv4/ip_conntrack_rtsp.h>
602 +#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
603 +
604 +#include <linux/inet.h>
605 +#include <linux/ctype.h>
606 +#define NF_NEED_STRNCASECMP
607 +#define NF_NEED_STRTOU16
608 +#include <linux/netfilter_helpers.h>
609 +#define NF_NEED_MIME_NEXTLINE
610 +#include <linux/netfilter_mime.h>
611 +
612 +#define INFOP(fmt, args...) printk(KERN_INFO "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
613 +#ifdef IP_NF_RTSP_DEBUG
614 +#define DEBUGP(fmt, args...) printk(KERN_DEBUG "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
615 +#else
616 +#define DEBUGP(fmt, args...)
617 +#endif
618 +
619 +#define MAX_PORTS 8
620 +#define DSTACT_AUTO 0
621 +#define DSTACT_STRIP 1
622 +#define DSTACT_NONE 2
623 +
624 +static int ports[MAX_PORTS];
625 +static char* stunaddr = NULL;
626 +static char* destaction = NULL;
627 +
628 +static int num_ports = 0;
629 +static u_int32_t extip = 0;
630 +static int dstact = 0;
631 +
632 +MODULE_AUTHOR("Tom Marshall <tmarshall@real.com>");
633 +MODULE_DESCRIPTION("RTSP network address translation module");
634 +MODULE_LICENSE("GPL");
635 +#ifdef MODULE_PARM
636 +MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_PORTS) "i");
637 +MODULE_PARM_DESC(ports, "port numbers of RTSP servers");
638 +MODULE_PARM(stunaddr, "s");
639 +MODULE_PARM_DESC(stunaddr, "Address for detecting STUN");
640 +MODULE_PARM(destaction, "s");
641 +MODULE_PARM_DESC(destaction, "Action for destination parameter (auto/strip/none)");
642 +#endif
643 +
644 +/* protects rtsp part of conntracks */
645 +DECLARE_LOCK_EXTERN(ip_rtsp_lock);
646 +
647 +#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
648 +
649 +/*** helper functions ***/
650 +
651 +static void
652 +get_skb_tcpdata(struct sk_buff* skb, char** pptcpdata, uint* ptcpdatalen)
653 +{
654 + struct iphdr* iph = (struct iphdr*)skb->nh.iph;
655 + struct tcphdr* tcph = (struct tcphdr*)((char*)iph + iph->ihl*4);
656 +
657 + *pptcpdata = (char*)tcph + tcph->doff*4;
658 + *ptcpdatalen = ((char*)skb->h.raw + skb->len) - *pptcpdata;
659 +}
660 +
661 +/*** nat functions ***/
662 +
663 +/*
664 + * Mangle the "Transport:" header:
665 + * - Replace all occurences of "client_port=<spec>"
666 + * - Handle destination parameter
667 + *
668 + * In:
669 + * ct, ctinfo = conntrack context
670 + * pskb = packet
671 + * tranoff = Transport header offset from TCP data
672 + * tranlen = Transport header length (incl. CRLF)
673 + * rport_lo = replacement low port (host endian)
674 + * rport_hi = replacement high port (host endian)
675 + *
676 + * Returns packet size difference.
677 + *
678 + * Assumes that a complete transport header is present, ending with CR or LF
679 + */
680 +static int
681 +rtsp_mangle_tran(struct ip_conntrack* ct, enum ip_conntrack_info ctinfo,
682 + struct ip_conntrack_expect* exp,
683 + struct sk_buff** pskb, uint tranoff, uint tranlen)
684 +{
685 + char* ptcp;
686 + uint tcplen;
687 + char* ptran;
688 + char rbuf1[16]; /* Replacement buffer (one port) */
689 + uint rbuf1len; /* Replacement len (one port) */
690 + char rbufa[16]; /* Replacement buffer (all ports) */
691 + uint rbufalen; /* Replacement len (all ports) */
692 + u_int32_t newip;
693 + u_int16_t loport, hiport;
694 + uint off = 0;
695 + uint diff; /* Number of bytes we removed */
696 +
697 + struct ip_ct_rtsp_expect* prtspexp = &exp->help.exp_rtsp_info;
698 + struct ip_conntrack_tuple t;
699 +
700 + char szextaddr[15+1];
701 + uint extaddrlen;
702 + int is_stun;
703 +
704 + get_skb_tcpdata(*pskb, &ptcp, &tcplen);
705 + ptran = ptcp+tranoff;
706 +
707 + if (tranoff+tranlen > tcplen || tcplen-tranoff < tranlen ||
708 + tranlen < 10 || !iseol(ptran[tranlen-1]) ||
709 + nf_strncasecmp(ptran, "Transport:", 10) != 0)
710 + {
711 + INFOP("sanity check failed\n");
712 + return 0;
713 + }
714 + off += 10;
715 + SKIP_WSPACE(ptcp+tranoff, tranlen, off);
716 +
717 + newip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
718 + t = exp->tuple;
719 + t.dst.ip = newip;
720 +
721 + extaddrlen = extip ? sprintf(szextaddr, "%u.%u.%u.%u", NIPQUAD(extip))
722 + : sprintf(szextaddr, "%u.%u.%u.%u", NIPQUAD(newip));
723 + DEBUGP("stunaddr=%s (%s)\n", szextaddr, (extip?"forced":"auto"));
724 +
725 + rbuf1len = rbufalen = 0;
726 + switch (prtspexp->pbtype)
727 + {
728 + case pb_single:
729 + for (loport = prtspexp->loport; loport != 0; loport++) /* XXX: improper wrap? */
730 + {
731 + t.dst.u.udp.port = htons(loport);
732 + if (ip_conntrack_change_expect(exp, &t) == 0)
733 + {
734 + DEBUGP("using port %hu\n", loport);
735 + break;
736 + }
737 + }
738 + if (loport != 0)
739 + {
740 + rbuf1len = sprintf(rbuf1, "%hu", loport);
741 + rbufalen = sprintf(rbufa, "%hu", loport);
742 + }
743 + break;
744 + case pb_range:
745 + for (loport = prtspexp->loport; loport != 0; loport += 2) /* XXX: improper wrap? */
746 + {
747 + t.dst.u.udp.port = htons(loport);
748 + if (ip_conntrack_change_expect(exp, &t) == 0)
749 + {
750 + hiport = loport + ~exp->mask.dst.u.udp.port;
751 + DEBUGP("using ports %hu-%hu\n", loport, hiport);
752 + break;
753 + }
754 + }
755 + if (loport != 0)
756 + {
757 + rbuf1len = sprintf(rbuf1, "%hu", loport);
758 + rbufalen = sprintf(rbufa, "%hu-%hu", loport, loport+1);
759 + }
760 + break;
761 + case pb_discon:
762 + for (loport = prtspexp->loport; loport != 0; loport++) /* XXX: improper wrap? */
763 + {
764 + t.dst.u.udp.port = htons(loport);
765 + if (ip_conntrack_change_expect(exp, &t) == 0)
766 + {
767 + DEBUGP("using port %hu (1 of 2)\n", loport);
768 + break;
769 + }
770 + }
771 + for (hiport = prtspexp->hiport; hiport != 0; hiport++) /* XXX: improper wrap? */
772 + {
773 + t.dst.u.udp.port = htons(hiport);
774 + if (ip_conntrack_change_expect(exp, &t) == 0)
775 + {
776 + DEBUGP("using port %hu (2 of 2)\n", hiport);
777 + break;
778 + }
779 + }
780 + if (loport != 0 && hiport != 0)
781 + {
782 + rbuf1len = sprintf(rbuf1, "%hu", loport);
783 + if (hiport == loport+1)
784 + {
785 + rbufalen = sprintf(rbufa, "%hu-%hu", loport, hiport);
786 + }
787 + else
788 + {
789 + rbufalen = sprintf(rbufa, "%hu/%hu", loport, hiport);
790 + }
791 + }
792 + break;
793 + }
794 +
795 + if (rbuf1len == 0)
796 + {
797 + return 0; /* cannot get replacement port(s) */
798 + }
799 +
800 + /* Transport: tran;field;field=val,tran;field;field=val,... */
801 + while (off < tranlen)
802 + {
803 + uint saveoff;
804 + const char* pparamend;
805 + uint nextparamoff;
806 +
807 + pparamend = memchr(ptran+off, ',', tranlen-off);
808 + pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
809 + nextparamoff = pparamend-ptcp;
810 +
811 + /*
812 + * We pass over each param twice. On the first pass, we look for a
813 + * destination= field. It is handled by the security policy. If it
814 + * is present, allowed, and equal to our external address, we assume
815 + * that STUN is being used and we leave the client_port= field alone.
816 + */
817 + is_stun = 0;
818 + saveoff = off;
819 + while (off < nextparamoff)
820 + {
821 + const char* pfieldend;
822 + uint nextfieldoff;
823 +
824 + pfieldend = memchr(ptran+off, ';', nextparamoff-off);
825 + nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
826 +
827 + if (dstact != DSTACT_NONE && strncmp(ptran+off, "destination=", 12) == 0)
828 + {
829 + if (strncmp(ptran+off+12, szextaddr, extaddrlen) == 0)
830 + {
831 + is_stun = 1;
832 + }
833 + if (dstact == DSTACT_STRIP || (dstact == DSTACT_AUTO && !is_stun))
834 + {
835 + diff = nextfieldoff-off;
836 + if (!ip_nat_mangle_tcp_packet(pskb, ct, ctinfo,
837 + off, diff, NULL, 0))
838 + {
839 + /* mangle failed, all we can do is bail */
840 + return 0;
841 + }
842 + get_skb_tcpdata(*pskb, &ptcp, &tcplen);
843 + ptran = ptcp+tranoff;
844 + tranlen -= diff;
845 + nextparamoff -= diff;
846 + nextfieldoff -= diff;
847 + }
848 + }
849 +
850 + off = nextfieldoff;
851 + }
852 + if (is_stun)
853 + {
854 + continue;
855 + }
856 + off = saveoff;
857 + while (off < nextparamoff)
858 + {
859 + const char* pfieldend;
860 + uint nextfieldoff;
861 +
862 + pfieldend = memchr(ptran+off, ';', nextparamoff-off);
863 + nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
864 +
865 + if (strncmp(ptran+off, "client_port=", 12) == 0)
866 + {
867 + u_int16_t port;
868 + uint numlen;
869 + uint origoff;
870 + uint origlen;
871 + char* rbuf = rbuf1;
872 + uint rbuflen = rbuf1len;
873 +
874 + off += 12;
875 + origoff = (ptran-ptcp)+off;
876 + origlen = 0;
877 + numlen = nf_strtou16(ptran+off, &port);
878 + off += numlen;
879 + origlen += numlen;
880 + if (port != prtspexp->loport)
881 + {
882 + DEBUGP("multiple ports found, port %hu ignored\n", port);
883 + }
884 + else
885 + {
886 + if (ptran[off] == '-' || ptran[off] == '/')
887 + {
888 + off++;
889 + origlen++;
890 + numlen = nf_strtou16(ptran+off, &port);
891 + off += numlen;
892 + origlen += numlen;
893 + rbuf = rbufa;
894 + rbuflen = rbufalen;
895 + }
896 +
897 + /*
898 + * note we cannot just memcpy() if the sizes are the same.
899 + * the mangle function does skb resizing, checks for a
900 + * cloned skb, and updates the checksums.
901 + *
902 + * parameter 4 below is offset from start of tcp data.
903 + */
904 + diff = origlen-rbuflen;
905 + if (!ip_nat_mangle_tcp_packet(pskb, ct, ctinfo,
906 + origoff, origlen, rbuf, rbuflen))
907 + {
908 + /* mangle failed, all we can do is bail */
909 + return 0;
910 + }
911 + get_skb_tcpdata(*pskb, &ptcp, &tcplen);
912 + ptran = ptcp+tranoff;
913 + tranlen -= diff;
914 + nextparamoff -= diff;
915 + nextfieldoff -= diff;
916 + }
917 + }
918 +
919 + off = nextfieldoff;
920 + }
921 +
922 + off = nextparamoff;
923 + }
924 +
925 + return 1;
926 +}
927 +
928 +static unsigned int
929 +expected(struct sk_buff **pskb, uint hooknum, struct ip_conntrack* ct, struct ip_nat_info* info)
930 +{
931 + struct ip_nat_multi_range mr;
932 + u_int32_t newdstip, newsrcip, newip;
933 +
934 + struct ip_conntrack *master = master_ct(ct);
935 +
936 + IP_NF_ASSERT(info);
937 + IP_NF_ASSERT(master);
938 +
939 + IP_NF_ASSERT(!(info->initialized & (1 << HOOK2MANIP(hooknum))));
940 +
941 + newdstip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
942 + newsrcip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
943 + newip = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC) ? newsrcip : newdstip;
944 +
945 + DEBUGP("newsrcip=%u.%u.%u.%u, newdstip=%u.%u.%u.%u, newip=%u.%u.%u.%u\n",
946 + NIPQUAD(newsrcip), NIPQUAD(newdstip), NIPQUAD(newip));
947 +
948 + mr.rangesize = 1;
949 + /* We don't want to manip the per-protocol, just the IPs. */
950 + mr.range[0].flags = IP_NAT_RANGE_MAP_IPS;
951 + mr.range[0].min_ip = mr.range[0].max_ip = newip;
952 +
953 + return ip_nat_setup_info(ct, &mr, hooknum);
954 +}
955 +
956 +static uint
957 +help_out(struct ip_conntrack* ct, enum ip_conntrack_info ctinfo,
958 + struct ip_conntrack_expect* exp, struct sk_buff** pskb)
959 +{
960 + char* ptcp;
961 + uint tcplen;
962 + uint hdrsoff;
963 + uint hdrslen;
964 + uint lineoff;
965 + uint linelen;
966 + uint off;
967 +
968 + struct iphdr* iph = (struct iphdr*)(*pskb)->nh.iph;
969 + struct tcphdr* tcph = (struct tcphdr*)((void*)iph + iph->ihl*4);
970 +
971 + struct ip_ct_rtsp_expect* prtspexp = &exp->help.exp_rtsp_info;
972 +
973 + get_skb_tcpdata(*pskb, &ptcp, &tcplen);
974 +
975 + hdrsoff = exp->seq - ntohl(tcph->seq);
976 + hdrslen = prtspexp->len;
977 + off = hdrsoff;
978 +
979 + while (nf_mime_nextline(ptcp, hdrsoff+hdrslen, &off, &lineoff, &linelen))
980 + {
981 + if (linelen == 0)
982 + {
983 + break;
984 + }
985 + if (off > hdrsoff+hdrslen)
986 + {
987 + INFOP("!! overrun !!");
988 + break;
989 + }
990 + DEBUGP("hdr: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
991 +
992 + if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0)
993 + {
994 + uint oldtcplen = tcplen;
995 + if (!rtsp_mangle_tran(ct, ctinfo, exp, pskb, lineoff, linelen))
996 + {
997 + break;
998 + }
999 + get_skb_tcpdata(*pskb, &ptcp, &tcplen);
1000 + hdrslen -= (oldtcplen-tcplen);
1001 + off -= (oldtcplen-tcplen);
1002 + lineoff -= (oldtcplen-tcplen);
1003 + linelen -= (oldtcplen-tcplen);
1004 + DEBUGP("rep: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
1005 + }
1006 + }
1007 +
1008 + return NF_ACCEPT;
1009 +}
1010 +
1011 +static uint
1012 +help_in(struct ip_conntrack* ct, enum ip_conntrack_info ctinfo,
1013 + struct ip_conntrack_expect* exp, struct sk_buff** pskb)
1014 +{
1015 + /* XXX: unmangle */
1016 + return NF_ACCEPT;
1017 +}
1018 +
1019 +static uint
1020 +help(struct ip_conntrack* ct,
1021 + struct ip_conntrack_expect* exp,
1022 + struct ip_nat_info* info,
1023 + enum ip_conntrack_info ctinfo,
1024 + unsigned int hooknum,
1025 + struct sk_buff** pskb)
1026 +{
1027 + struct iphdr* iph = (struct iphdr*)(*pskb)->nh.iph;
1028 + struct tcphdr* tcph = (struct tcphdr*)((char*)iph + iph->ihl * 4);
1029 + uint datalen;
1030 + int dir;
1031 + struct ip_ct_rtsp_expect* ct_rtsp_info;
1032 + int rc = NF_ACCEPT;
1033 +
1034 + if (ct == NULL || exp == NULL || info == NULL || pskb == NULL)
1035 + {
1036 + DEBUGP("!! null ptr (%p,%p,%p,%p) !!\n", ct, exp, info, pskb);
1037 + return NF_ACCEPT;
1038 + }
1039 +
1040 + ct_rtsp_info = &exp->help.exp_rtsp_info;
1041 +
1042 + /*
1043 + * Only mangle things once: original direction in POST_ROUTING
1044 + * and reply direction on PRE_ROUTING.
1045 + */
1046 + dir = CTINFO2DIR(ctinfo);
1047 + if (!((hooknum == NF_IP_POST_ROUTING && dir == IP_CT_DIR_ORIGINAL)
1048 + || (hooknum == NF_IP_PRE_ROUTING && dir == IP_CT_DIR_REPLY)))
1049 + {
1050 + DEBUGP("Not touching dir %s at hook %s\n",
1051 + dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY",
1052 + hooknum == NF_IP_POST_ROUTING ? "POSTROUTING"
1053 + : hooknum == NF_IP_PRE_ROUTING ? "PREROUTING"
1054 + : hooknum == NF_IP_LOCAL_OUT ? "OUTPUT" : "???");
1055 + return NF_ACCEPT;
1056 + }
1057 + DEBUGP("got beyond not touching\n");
1058 +
1059 + datalen = (*pskb)->len - iph->ihl * 4 - tcph->doff * 4;
1060 +
1061 + LOCK_BH(&ip_rtsp_lock);
1062 + /* Ensure the packet contains all of the marked data */
1063 + if (!between(exp->seq + ct_rtsp_info->len,
1064 + ntohl(tcph->seq), ntohl(tcph->seq) + datalen))
1065 + {
1066 + /* Partial retransmission? Probably a hacker. */
1067 + if (net_ratelimit())
1068 + {
1069 + INFOP("partial packet %u/%u in %u/%u\n",
1070 + exp->seq, ct_rtsp_info->len, ntohl(tcph->seq), ntohl(tcph->seq) + datalen);
1071 + }
1072 + UNLOCK_BH(&ip_rtsp_lock);
1073 + return NF_DROP;
1074 + }
1075 +
1076 + switch (dir)
1077 + {
1078 + case IP_CT_DIR_ORIGINAL:
1079 + rc = help_out(ct, ctinfo, exp, pskb);
1080 + break;
1081 + case IP_CT_DIR_REPLY:
1082 + rc = help_in(ct, ctinfo, exp, pskb);
1083 + break;
1084 + }
1085 + UNLOCK_BH(&ip_rtsp_lock);
1086 +
1087 + return rc;
1088 +}
1089 +
1090 +static struct ip_nat_helper ip_nat_rtsp_helpers[MAX_PORTS];
1091 +static char rtsp_names[MAX_PORTS][10];
1092 +
1093 +/* This function is intentionally _NOT_ defined as __exit */
1094 +static void
1095 +fini(void)
1096 +{
1097 + int i;
1098 +
1099 + for (i = 0; i < num_ports; i++)
1100 + {
1101 + DEBUGP("unregistering helper for port %d\n", ports[i]);
1102 + ip_nat_helper_unregister(&ip_nat_rtsp_helpers[i]);
1103 + }
1104 +}
1105 +
1106 +static int __init
1107 +init(void)
1108 +{
1109 + int ret = 0;
1110 + int i;
1111 + struct ip_nat_helper* hlpr;
1112 + char* tmpname;
1113 +
1114 + printk("ip_nat_rtsp v" IP_NF_RTSP_VERSION " loading\n");
1115 +
1116 + if (ports[0] == 0)
1117 + {
1118 + ports[0] = RTSP_PORT;
1119 + }
1120 +
1121 + for (i = 0; (i < MAX_PORTS) && ports[i] != 0; i++)
1122 + {
1123 + hlpr = &ip_nat_rtsp_helpers[i];
1124 + memset(hlpr, 0, sizeof(struct ip_nat_helper));
1125 +
1126 + hlpr->tuple.dst.protonum = IPPROTO_TCP;
1127 + hlpr->tuple.src.u.tcp.port = htons(ports[i]);
1128 + hlpr->mask.src.u.tcp.port = 0xFFFF;
1129 + hlpr->mask.dst.protonum = 0xFFFF;
1130 + hlpr->help = help;
1131 + hlpr->flags = 0;
1132 + hlpr->me = THIS_MODULE;
1133 + hlpr->expect = expected;
1134 +
1135 + tmpname = &rtsp_names[i][0];
1136 + if (ports[i] == RTSP_PORT)
1137 + {
1138 + sprintf(tmpname, "rtsp");
1139 + }
1140 + else
1141 + {
1142 + sprintf(tmpname, "rtsp-%d", i);
1143 + }
1144 + hlpr->name = tmpname;
1145 +
1146 + DEBUGP("registering helper for port %d: name %s\n", ports[i], hlpr->name);
1147 + ret = ip_nat_helper_register(hlpr);
1148 +
1149 + if (ret)
1150 + {
1151 + printk("ip_nat_rtsp: error registering helper for port %d\n", ports[i]);
1152 + fini();
1153 + return 1;
1154 + }
1155 + num_ports++;
1156 + }
1157 + if (stunaddr != NULL)
1158 + {
1159 + extip = in_aton(stunaddr);
1160 + }
1161 + if (destaction != NULL)
1162 + {
1163 + if (strcmp(destaction, "auto") == 0)
1164 + {
1165 + dstact = DSTACT_AUTO;
1166 + }
1167 + if (strcmp(destaction, "strip") == 0)
1168 + {
1169 + dstact = DSTACT_STRIP;
1170 + }
1171 + if (strcmp(destaction, "none") == 0)
1172 + {
1173 + dstact = DSTACT_NONE;
1174 + }
1175 + }
1176 + return ret;
1177 +}
1178 +
1179 +module_init(init);
1180 +module_exit(fini);
1181 --- a/arch/mips/kernel/mips_ksyms.c
1182 +++ b/arch/mips/kernel/mips_ksyms.c
1183 @@ -52,6 +52,7 @@ EXPORT_SYMBOL(EISA_bus);
1184 /*
1185 * String functions
1186 */
1187 +EXPORT_SYMBOL_NOVERS(memchr);
1188 EXPORT_SYMBOL_NOVERS(memcmp);
1189 EXPORT_SYMBOL_NOVERS(memset);
1190 EXPORT_SYMBOL_NOVERS(memcpy);
1191 --- /dev/null
1192 +++ b/include/linux/netfilter_helpers.h
1193 @@ -0,0 +1,133 @@
1194 +/*
1195 + * Helpers for netfiler modules. This file provides implementations for basic
1196 + * functions such as strncasecmp(), etc.
1197 + *
1198 + * gcc will warn for defined but unused functions, so we only include the
1199 + * functions requested. The following macros are used:
1200 + * NF_NEED_STRNCASECMP nf_strncasecmp()
1201 + * NF_NEED_STRTOU16 nf_strtou16()
1202 + * NF_NEED_STRTOU32 nf_strtou32()
1203 + */
1204 +#ifndef _NETFILTER_HELPERS_H
1205 +#define _NETFILTER_HELPERS_H
1206 +
1207 +/* Only include these functions for kernel code. */
1208 +#ifdef __KERNEL__
1209 +
1210 +#include <linux/ctype.h>
1211 +#define iseol(c) ( (c) == '\r' || (c) == '\n' )
1212 +
1213 +/*
1214 + * The standard strncasecmp()
1215 + */
1216 +#ifdef NF_NEED_STRNCASECMP
1217 +static int
1218 +nf_strncasecmp(const char* s1, const char* s2, u_int32_t len)
1219 +{
1220 + if (s1 == NULL || s2 == NULL)
1221 + {
1222 + if (s1 == NULL && s2 == NULL)
1223 + {
1224 + return 0;
1225 + }
1226 + return (s1 == NULL) ? -1 : 1;
1227 + }
1228 + while (len > 0 && tolower(*s1) == tolower(*s2))
1229 + {
1230 + len--;
1231 + s1++;
1232 + s2++;
1233 + }
1234 + return ( (len == 0) ? 0 : (tolower(*s1) - tolower(*s2)) );
1235 +}
1236 +#endif /* NF_NEED_STRNCASECMP */
1237 +
1238 +/*
1239 + * Parse a string containing a 16-bit unsigned integer.
1240 + * Returns the number of chars used, or zero if no number is found.
1241 + */
1242 +#ifdef NF_NEED_STRTOU16
1243 +static int
1244 +nf_strtou16(const char* pbuf, u_int16_t* pval)
1245 +{
1246 + int n = 0;
1247 +
1248 + *pval = 0;
1249 + while (isdigit(pbuf[n]))
1250 + {
1251 + *pval = (*pval * 10) + (pbuf[n] - '0');
1252 + n++;
1253 + }
1254 +
1255 + return n;
1256 +}
1257 +#endif /* NF_NEED_STRTOU16 */
1258 +
1259 +/*
1260 + * Parse a string containing a 32-bit unsigned integer.
1261 + * Returns the number of chars used, or zero if no number is found.
1262 + */
1263 +#ifdef NF_NEED_STRTOU32
1264 +static int
1265 +nf_strtou32(const char* pbuf, u_int32_t* pval)
1266 +{
1267 + int n = 0;
1268 +
1269 + *pval = 0;
1270 + while (pbuf[n] >= '0' && pbuf[n] <= '9')
1271 + {
1272 + *pval = (*pval * 10) + (pbuf[n] - '0');
1273 + n++;
1274 + }
1275 +
1276 + return n;
1277 +}
1278 +#endif /* NF_NEED_STRTOU32 */
1279 +
1280 +/*
1281 + * Given a buffer and length, advance to the next line and mark the current
1282 + * line.
1283 + */
1284 +#ifdef NF_NEED_NEXTLINE
1285 +static int
1286 +nf_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
1287 +{
1288 + uint off = *poff;
1289 + uint physlen = 0;
1290 +
1291 + if (off >= len)
1292 + {
1293 + return 0;
1294 + }
1295 +
1296 + while (p[off] != '\n')
1297 + {
1298 + if (len-off <= 1)
1299 + {
1300 + return 0;
1301 + }
1302 +
1303 + physlen++;
1304 + off++;
1305 + }
1306 +
1307 + /* if we saw a crlf, physlen needs adjusted */
1308 + if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
1309 + {
1310 + physlen--;
1311 + }
1312 +
1313 + /* advance past the newline */
1314 + off++;
1315 +
1316 + *plineoff = *poff;
1317 + *plinelen = physlen;
1318 + *poff = off;
1319 +
1320 + return 1;
1321 +}
1322 +#endif /* NF_NEED_NEXTLINE */
1323 +
1324 +#endif /* __KERNEL__ */
1325 +
1326 +#endif /* _NETFILTER_HELPERS_H */
1327 --- /dev/null
1328 +++ b/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h
1329 @@ -0,0 +1,68 @@
1330 +/*
1331 + * RTSP extension for IP connection tracking.
1332 + * (C) 2003 by Tom Marshall <tmarshall@real.com>
1333 + * based on ip_conntrack_irc.h
1334 + *
1335 + * This program is free software; you can redistribute it and/or
1336 + * modify it under the terms of the GNU General Public License
1337 + * as published by the Free Software Foundation; either version
1338 + * 2 of the License, or (at your option) any later version.
1339 + */
1340 +#ifndef _IP_CONNTRACK_RTSP_H
1341 +#define _IP_CONNTRACK_RTSP_H
1342 +
1343 +/* #define IP_NF_RTSP_DEBUG */
1344 +#define IP_NF_RTSP_VERSION "0.01"
1345 +
1346 +/* port block types */
1347 +typedef enum {
1348 + pb_single, /* client_port=x */
1349 + pb_range, /* client_port=x-y */
1350 + pb_discon /* client_port=x/y (rtspbis) */
1351 +} portblock_t;
1352 +
1353 +/* We record seq number and length of rtsp headers here, all in host order. */
1354 +
1355 +/*
1356 + * This structure is per expected connection. It is a member of struct
1357 + * ip_conntrack_expect. The TCP SEQ for the conntrack expect is stored
1358 + * there and we are expected to only store the length of the data which
1359 + * needs replaced. If a packet contains multiple RTSP messages, we create
1360 + * one expected connection per message.
1361 + *
1362 + * We use these variables to mark the entire header block. This may seem
1363 + * like overkill, but the nature of RTSP requires it. A header may appear
1364 + * multiple times in a message. We must treat two Transport headers the
1365 + * same as one Transport header with two entries.
1366 + */
1367 +struct ip_ct_rtsp_expect
1368 +{
1369 + u_int32_t len; /* length of header block */
1370 + portblock_t pbtype; /* Type of port block that was requested */
1371 + u_int16_t loport; /* Port that was requested, low or first */
1372 + u_int16_t hiport; /* Port that was requested, high or second */
1373 +#if 0
1374 + uint method; /* RTSP method */
1375 + uint cseq; /* CSeq from request */
1376 +#endif
1377 +};
1378 +
1379 +/* This structure exists only once per master */
1380 +struct ip_ct_rtsp_master
1381 +{
1382 + /* Empty (?) */
1383 +};
1384 +
1385 +
1386 +#ifdef __KERNEL__
1387 +
1388 +#include <linux/netfilter_ipv4/lockhelp.h>
1389 +
1390 +#define RTSP_PORT 554
1391 +
1392 +/* Protects rtsp part of conntracks */
1393 +DECLARE_LOCK_EXTERN(ip_rtsp_lock);
1394 +
1395 +#endif /* __KERNEL__ */
1396 +
1397 +#endif /* _IP_CONNTRACK_RTSP_H */
1398 --- /dev/null
1399 +++ b/include/linux/netfilter_mime.h
1400 @@ -0,0 +1,90 @@
1401 +/*
1402 + * MIME functions for netfilter modules. This file provides implementations
1403 + * for basic MIME parsing. MIME headers are used in many protocols, such as
1404 + * HTTP, RTSP, SIP, etc.
1405 + *
1406 + * gcc will warn for defined but unused functions, so we only include the
1407 + * functions requested. The following macros are used:
1408 + * NF_NEED_MIME_NEXTLINE nf_mime_nextline()
1409 + */
1410 +#ifndef _NETFILTER_MIME_H
1411 +#define _NETFILTER_MIME_H
1412 +
1413 +/* Only include these functions for kernel code. */
1414 +#ifdef __KERNEL__
1415 +
1416 +#include <linux/kernel.h>
1417 +#include <linux/ctype.h>
1418 +
1419 +/*
1420 + * Given a buffer and length, advance to the next line and mark the current
1421 + * line. If the current line is empty, *plinelen will be set to zero. If
1422 + * not, it will be set to the actual line length (including CRLF).
1423 + *
1424 + * 'line' in this context means logical line (includes LWS continuations).
1425 + * Returns 1 on success, 0 on failure.
1426 + */
1427 +#ifdef NF_NEED_MIME_NEXTLINE
1428 +static int
1429 +nf_mime_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
1430 +{
1431 + uint off = *poff;
1432 + uint physlen = 0;
1433 + int is_first_line = 1;
1434 +
1435 + if (off >= len)
1436 + {
1437 + return 0;
1438 + }
1439 +
1440 + do
1441 + {
1442 + while (p[off] != '\n')
1443 + {
1444 + if (len-off <= 1)
1445 + {
1446 + return 0;
1447 + }
1448 +
1449 + physlen++;
1450 + off++;
1451 + }
1452 +
1453 + /* if we saw a crlf, physlen needs adjusted */
1454 + if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
1455 + {
1456 + physlen--;
1457 + }
1458 +
1459 + /* advance past the newline */
1460 + off++;
1461 +
1462 + /* check for an empty line */
1463 + if (physlen == 0)
1464 + {
1465 + break;
1466 + }
1467 +
1468 + /* check for colon on the first physical line */
1469 + if (is_first_line)
1470 + {
1471 + is_first_line = 0;
1472 + if (memchr(p+(*poff), ':', physlen) == NULL)
1473 + {
1474 + return 0;
1475 + }
1476 + }
1477 + }
1478 + while (p[off] == ' ' || p[off] == '\t');
1479 +
1480 + *plineoff = *poff;
1481 + *plinelen = (physlen == 0) ? 0 : (off - *poff);
1482 + *poff = off;
1483 +
1484 + return 1;
1485 +}
1486 +#endif /* NF_NEED_MIME_NEXTLINE */
1487 +
1488 +#endif /* __KERNEL__ */
1489 +
1490 +#endif /* _NETFILTER_MIME_H */
1491 --- a/include/linux/netfilter_ipv4/ip_conntrack.h
1492 +++ b/include/linux/netfilter_ipv4/ip_conntrack.h
1493 @@ -72,6 +72,7 @@ union ip_conntrack_expect_proto {
1494 #include <linux/netfilter_ipv4/ip_conntrack_irc.h>
1495 #include <linux/netfilter_ipv4/ip_conntrack_pptp.h>
1496 #include <linux/netfilter_ipv4/ip_conntrack_h323.h>
1497 +#include <linux/netfilter_ipv4/ip_conntrack_rtsp.h>
1498
1499 /* per expectation: application helper private data */
1500 union ip_conntrack_expect_help {
1501 @@ -81,6 +82,7 @@ union ip_conntrack_expect_help {
1502 struct ip_ct_irc_expect exp_irc_info;
1503 struct ip_ct_pptp_expect exp_pptp_info;
1504 struct ip_ct_h225_expect exp_h225_info;
1505 + struct ip_ct_rtsp_expect exp_rtsp_info;
1506
1507 #ifdef CONFIG_IP_NF_NAT_NEEDED
1508 union {
1509 @@ -96,6 +98,7 @@ union ip_conntrack_help {
1510 struct ip_ct_irc_master ct_irc_info;
1511 struct ip_ct_pptp_master ct_pptp_info;
1512 struct ip_ct_h225_master ct_h225_info;
1513 + struct ip_ct_rtsp_master ct_rtsp_info;
1514 };
1515
1516 #ifdef CONFIG_IP_NF_NAT_NEEDED