1/*-
2 * alias_skinny.c
3 *
4 * Copyright (c) 2002, 2003 MarcusCom, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * Author: Joe Marcus Clarke <marcus@FreeBSD.org>
29 *
30 * $FreeBSD: head/sys/netinet/libalias/alias_skinny.c 259858 2013-12-25 02:06:57Z glebius $
31 */
32
33#ifdef _KERNEL
34#include <sys/param.h>
35#include <sys/kernel.h>
36#include <sys/module.h>
37#else
38#include <errno.h>
39#include <stdio.h>
40#include <unistd.h>
41#endif
42
43#include <netinet/in_systm.h>
44#include <netinet/in.h>
45#include <netinet/ip.h>
46#include <netinet/tcp.h>
47
48#ifdef _KERNEL
49#include <netinet/libalias/alias_local.h>
50#include <netinet/libalias/alias_mod.h>
51#else
52#include "alias_local.h"
53#include "alias_mod.h"
54#endif
55
56static void
57AliasHandleSkinny(struct libalias *, struct ip *, struct alias_link *);
58
59static int
60fingerprint(struct libalias *la, struct alias_data *ah)
61{
62
63 if (ah->dport == NULL || ah->sport == NULL || ah->lnk == NULL)
64 return (-1);
65 if (la->skinnyPort != 0 && (ntohs(*ah->sport) == la->skinnyPort ||
66 ntohs(*ah->dport) == la->skinnyPort))
67 return (0);
68 return (-1);
69}
70
71static int
72protohandler(struct libalias *la, struct ip *pip, struct alias_data *ah)
73{
74
75 AliasHandleSkinny(la, pip, ah->lnk);
76 return (0);
77}
78
79struct proto_handler handlers[] = {
80 {
81 .pri = 110,
82 .dir = IN|OUT,
83 .proto = TCP,
84 .fingerprint = &fingerprint,
85 .protohandler = &protohandler
86 },
87 { EOH }
88};
89
90static int
91mod_handler(module_t mod, int type, void *data)
92{
93 int error;
94
95 switch (type) {
96 case MOD_LOAD:
97 error = 0;
98 LibAliasAttachHandlers(handlers);
99 break;
100 case MOD_UNLOAD:
101 error = 0;
102 LibAliasDetachHandlers(handlers);
103 break;
104 default:
105 error = EINVAL;
106 }
107 return (error);
108}
109
110#ifdef _KERNEL
111static
112#endif
113moduledata_t alias_mod = {
114 "alias_skinny", mod_handler, NULL
115};
116
117#ifdef _KERNEL
118DECLARE_MODULE(alias_skinny, alias_mod, SI_SUB_DRIVERS, SI_ORDER_SECOND);
119MODULE_VERSION(alias_skinny, 1);
120MODULE_DEPEND(alias_skinny, libalias, 1, 1, 1);
121#endif
122
123/*
124 * alias_skinny.c handles the translation for the Cisco Skinny Station
125 * protocol. Skinny typically uses TCP port 2000 to set up calls between
126 * a Cisco Call Manager and a Cisco IP phone. When a phone comes on line,
127 * it first needs to register with the Call Manager. To do this it sends
128 * a registration message. This message contains the IP address of the
129 * IP phone. This message must then be translated to reflect our global
130 * IP address. Along with the registration message (and usually in the
131 * same packet), the phone sends an IP port message. This message indicates
132 * the TCP port over which it will communicate.
133 *
134 * When a call is placed from the phone, the Call Manager will send an
135 * Open Receive Channel message to the phone to let the caller know someone
136 * has answered. The phone then sends back an Open Receive Channel
137 * Acknowledgement. In this packet, the phone sends its IP address again,
138 * and the UDP port over which the voice traffic should flow. These values
139 * need translation. Right after the Open Receive Channel Acknowledgement,
140 * the Call Manager sends a Start Media Transmission message indicating the
141 * call is connected. This message contains the IP address and UDP port
142 * number of the remote (called) party. Once this message is translated, the
143 * call can commence. The called part sends the first UDP packet to the
144 * calling phone at the pre-arranged UDP port in the Open Receive Channel
145 * Acknowledgement.
146 *
147 * Skinny is a Cisco-proprietary protocol and is a trademark of Cisco Systems,
148 * Inc. All rights reserved.
149*/
150
151/* #define LIBALIAS_DEBUG 1 */
152
153/* Message types that need translating */
154#define REG_MSG 0x00000001
155#define IP_PORT_MSG 0x00000002
156#define OPNRCVCH_ACK 0x00000022
157#define START_MEDIATX 0x0000008a
158
159struct skinny_header {
160 u_int32_t len;
161 u_int32_t reserved;
162 u_int32_t msgId;
163};
164
165struct RegisterMessage {
166 u_int32_t msgId;
167 char devName [16];
168 u_int32_t uid;
169 u_int32_t instance;
170 u_int32_t ipAddr;
171 u_char devType;
172 u_int32_t maxStreams;
173};
174
175struct IpPortMessage {
176 u_int32_t msgId;
177 u_int32_t stationIpPort; /* Note: Skinny uses 32-bit port
178 * numbers */
179};
180
181struct OpenReceiveChannelAck {
182 u_int32_t msgId;
183 u_int32_t status;
184 u_int32_t ipAddr;
185 u_int32_t port;
186 u_int32_t passThruPartyID;
187};
188
189struct StartMediaTransmission {
190 u_int32_t msgId;
191 u_int32_t conferenceID;
192 u_int32_t passThruPartyID;
193 u_int32_t remoteIpAddr;
194 u_int32_t remotePort;
195 u_int32_t MSPacket;
196 u_int32_t payloadCap;
197 u_int32_t precedence;
198 u_int32_t silenceSuppression;
199 u_short maxFramesPerPacket;
200 u_int32_t G723BitRate;
201};
202
203typedef enum {
204 ClientToServer = 0,
205 ServerToClient = 1
206} ConvDirection;
207
208
209static int
210alias_skinny_reg_msg(struct RegisterMessage *reg_msg, struct ip *pip,
211 struct tcphdr *tc, struct alias_link *lnk,
212 ConvDirection direction)
213{
214 (void)direction;
215
216 reg_msg->ipAddr = (u_int32_t) GetAliasAddress(lnk).s_addr;
217
218 tc->th_sum = 0;
219#ifdef _KERNEL
220 tc->th_x2 = 1;
221#else
222 tc->th_sum = TcpChecksum(pip);
223#endif
224
225 return (0);
226}
227
228static int
229alias_skinny_startmedia(struct StartMediaTransmission *start_media,
230 struct ip *pip, struct tcphdr *tc,
231 struct alias_link *lnk, u_int32_t localIpAddr,
232 ConvDirection direction)
233{
234 struct in_addr dst, src;
235
236 (void)pip;
237 (void)tc;
238 (void)lnk;
239 (void)direction;
240
241 dst.s_addr = start_media->remoteIpAddr;
242 src.s_addr = localIpAddr;
243
244 /*
245 * XXX I should probably handle in bound global translations as
246 * well.
247 */
248
249 return (0);
250}
251
252static int
253alias_skinny_port_msg(struct IpPortMessage *port_msg, struct ip *pip,
254 struct tcphdr *tc, struct alias_link *lnk,
255 ConvDirection direction)
256{
257 (void)direction;
258
259 port_msg->stationIpPort = (u_int32_t) ntohs(GetAliasPort(lnk));
260
261 tc->th_sum = 0;
262#ifdef _KERNEL
263 tc->th_x2 = 1;
264#else
265 tc->th_sum = TcpChecksum(pip);
266#endif
267 return (0);
268}
269
270static int
271alias_skinny_opnrcvch_ack(struct libalias *la, struct OpenReceiveChannelAck *opnrcvch_ack,
272 struct ip *pip, struct tcphdr *tc,
273 struct alias_link *lnk, u_int32_t * localIpAddr,
274 ConvDirection direction)
275{
276 struct in_addr null_addr;
277 struct alias_link *opnrcv_lnk;
278 u_int32_t localPort;
279
280 (void)lnk;
281 (void)direction;
282
283 *localIpAddr = (u_int32_t) opnrcvch_ack->ipAddr;
284 localPort = opnrcvch_ack->port;
285
286 null_addr.s_addr = INADDR_ANY;
287 opnrcv_lnk = FindUdpTcpOut(la, pip->ip_src, null_addr,
288 htons((u_short) opnrcvch_ack->port), 0,
289 IPPROTO_UDP, 1);
290 opnrcvch_ack->ipAddr = (u_int32_t) GetAliasAddress(opnrcv_lnk).s_addr;
291 opnrcvch_ack->port = (u_int32_t) ntohs(GetAliasPort(opnrcv_lnk));
292
293 tc->th_sum = 0;
294#ifdef _KERNEL
295 tc->th_x2 = 1;
296#else
297 tc->th_sum = TcpChecksum(pip);
298#endif
299 return (0);
300}
301
302static void
303AliasHandleSkinny(struct libalias *la, struct ip *pip, struct alias_link *lnk)
304{
305 size_t hlen, tlen, dlen;
306 struct tcphdr *tc;
307 u_int32_t msgId, t, len, lip;
308 struct skinny_header *sd;
309 size_t orig_len, skinny_hdr_len = sizeof(struct skinny_header);
310 ConvDirection direction;
311
312 lip = -1;
313 tc = (struct tcphdr *)ip_next(pip);
314 hlen = (pip->ip_hl + tc->th_off) << 2;
315 tlen = ntohs(pip->ip_len);
316 dlen = tlen - hlen;
317
318 sd = (struct skinny_header *)tcp_next(tc);
319
320 /*
321 * XXX This direction is reserved for future use. I still need to
322 * handle the scenario where the call manager is on the inside, and
323 * the calling phone is on the global outside.
324 */
325 if (ntohs(tc->th_dport) == la->skinnyPort) {
326 direction = ClientToServer;
327 } else if (ntohs(tc->th_sport) == la->skinnyPort) {
328 direction = ServerToClient;
329 } else {
330#ifdef LIBALIAS_DEBUG
331 fprintf(stderr,
332 "PacketAlias/Skinny: Invalid port number, not a Skinny packet\n");
333#endif
334 return;
335 }
336
337 orig_len = dlen;
338 /*
339 * Skinny packets can contain many messages. We need to loop
340 * through the packet using len to determine message boundaries.
341 * This comes into play big time with port messages being in the
342 * same packet as register messages. Also, open receive channel
343 * acks are usually buried in a packet some 400 bytes long.
344 */
345 while (dlen >= skinny_hdr_len) {
346 len = (sd->len);
347 msgId = (sd->msgId);
348 t = len;
349
350 if (t > orig_len || t > dlen) {
351#ifdef LIBALIAS_DEBUG
352 fprintf(stderr,
353 "PacketAlias/Skinny: Not a skinny packet, invalid length \n");
354#endif
355 return;
356 }
357 switch (msgId) {
358 case REG_MSG: {
359 struct RegisterMessage *reg_mesg;
360
361 if (len < (int)sizeof(struct RegisterMessage)) {
362#ifdef LIBALIAS_DEBUG
363 fprintf(stderr,
364 "PacketAlias/Skinny: Not a skinny packet, bad registration message\n");
365#endif
366 return;
367 }
368 reg_mesg = (struct RegisterMessage *)&sd->msgId;
369#ifdef LIBALIAS_DEBUG
370 fprintf(stderr,
371 "PacketAlias/Skinny: Received a register message");
372#endif
373 alias_skinny_reg_msg(reg_mesg, pip, tc, lnk, direction);
374 break;
375 }
376 case IP_PORT_MSG: {
377 struct IpPortMessage *port_mesg;
378
379 if (len < (int)sizeof(struct IpPortMessage)) {
380#ifdef LIBALIAS_DEBUG
381 fprintf(stderr,
382 "PacketAlias/Skinny: Not a skinny packet, port message\n");
383#endif
384 return;
385 }
386#ifdef LIBALIAS_DEBUG
387 fprintf(stderr,
388 "PacketAlias/Skinny: Received ipport message\n");
389#endif
390 port_mesg = (struct IpPortMessage *)&sd->msgId;
391 alias_skinny_port_msg(port_mesg, pip, tc, lnk, direction);
392 break;
393 }
394 case OPNRCVCH_ACK: {
395 struct OpenReceiveChannelAck *opnrcvchn_ack;
396
397 if (len < (int)sizeof(struct OpenReceiveChannelAck)) {
398#ifdef LIBALIAS_DEBUG
399 fprintf(stderr,
400 "PacketAlias/Skinny: Not a skinny packet, packet,OpnRcvChnAckMsg\n");
401#endif
402 return;
403 }
404#ifdef LIBALIAS_DEBUG
405 fprintf(stderr,
406 "PacketAlias/Skinny: Received open rcv channel msg\n");
407#endif
408 opnrcvchn_ack = (struct OpenReceiveChannelAck *)&sd->msgId;
409 alias_skinny_opnrcvch_ack(la, opnrcvchn_ack, pip, tc, lnk, &lip, direction);
410 break;
411 }
412 case START_MEDIATX: {
413 struct StartMediaTransmission *startmedia_tx;
414
415 if (len < (int)sizeof(struct StartMediaTransmission)) {
416#ifdef LIBALIAS_DEBUG
417 fprintf(stderr,
418 "PacketAlias/Skinny: Not a skinny packet,StartMediaTx Message\n");
419#endif
420 return;
421 }
422 if (lip == -1) {
423#ifdef LIBALIAS_DEBUG
424 fprintf(stderr,
425 "PacketAlias/Skinny: received a"
426 " packet,StartMediaTx Message before"
427 " packet,OpnRcvChnAckMsg\n"
428#endif
429 return;
430 }
431
432#ifdef LIBALIAS_DEBUG
433 fprintf(stderr,
434 "PacketAlias/Skinny: Received start media trans msg\n");
435#endif
436 startmedia_tx = (struct StartMediaTransmission *)&sd->msgId;
437 alias_skinny_startmedia(startmedia_tx, pip, tc, lnk, lip, direction);
438 break;
439 }
440 default:
441 break;
442 }
443 /* Place the pointer at the next message in the packet. */
444 dlen -= len + (skinny_hdr_len - sizeof(msgId));
445 sd = (struct skinny_header *)(((char *)&sd->msgId) + len);
446 }
447}
2 * alias_skinny.c
3 *
4 * Copyright (c) 2002, 2003 MarcusCom, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * Author: Joe Marcus Clarke <marcus@FreeBSD.org>
29 *
30 * $FreeBSD: head/sys/netinet/libalias/alias_skinny.c 259858 2013-12-25 02:06:57Z glebius $
31 */
32
33#ifdef _KERNEL
34#include <sys/param.h>
35#include <sys/kernel.h>
36#include <sys/module.h>
37#else
38#include <errno.h>
39#include <stdio.h>
40#include <unistd.h>
41#endif
42
43#include <netinet/in_systm.h>
44#include <netinet/in.h>
45#include <netinet/ip.h>
46#include <netinet/tcp.h>
47
48#ifdef _KERNEL
49#include <netinet/libalias/alias_local.h>
50#include <netinet/libalias/alias_mod.h>
51#else
52#include "alias_local.h"
53#include "alias_mod.h"
54#endif
55
56static void
57AliasHandleSkinny(struct libalias *, struct ip *, struct alias_link *);
58
59static int
60fingerprint(struct libalias *la, struct alias_data *ah)
61{
62
63 if (ah->dport == NULL || ah->sport == NULL || ah->lnk == NULL)
64 return (-1);
65 if (la->skinnyPort != 0 && (ntohs(*ah->sport) == la->skinnyPort ||
66 ntohs(*ah->dport) == la->skinnyPort))
67 return (0);
68 return (-1);
69}
70
71static int
72protohandler(struct libalias *la, struct ip *pip, struct alias_data *ah)
73{
74
75 AliasHandleSkinny(la, pip, ah->lnk);
76 return (0);
77}
78
79struct proto_handler handlers[] = {
80 {
81 .pri = 110,
82 .dir = IN|OUT,
83 .proto = TCP,
84 .fingerprint = &fingerprint,
85 .protohandler = &protohandler
86 },
87 { EOH }
88};
89
90static int
91mod_handler(module_t mod, int type, void *data)
92{
93 int error;
94
95 switch (type) {
96 case MOD_LOAD:
97 error = 0;
98 LibAliasAttachHandlers(handlers);
99 break;
100 case MOD_UNLOAD:
101 error = 0;
102 LibAliasDetachHandlers(handlers);
103 break;
104 default:
105 error = EINVAL;
106 }
107 return (error);
108}
109
110#ifdef _KERNEL
111static
112#endif
113moduledata_t alias_mod = {
114 "alias_skinny", mod_handler, NULL
115};
116
117#ifdef _KERNEL
118DECLARE_MODULE(alias_skinny, alias_mod, SI_SUB_DRIVERS, SI_ORDER_SECOND);
119MODULE_VERSION(alias_skinny, 1);
120MODULE_DEPEND(alias_skinny, libalias, 1, 1, 1);
121#endif
122
123/*
124 * alias_skinny.c handles the translation for the Cisco Skinny Station
125 * protocol. Skinny typically uses TCP port 2000 to set up calls between
126 * a Cisco Call Manager and a Cisco IP phone. When a phone comes on line,
127 * it first needs to register with the Call Manager. To do this it sends
128 * a registration message. This message contains the IP address of the
129 * IP phone. This message must then be translated to reflect our global
130 * IP address. Along with the registration message (and usually in the
131 * same packet), the phone sends an IP port message. This message indicates
132 * the TCP port over which it will communicate.
133 *
134 * When a call is placed from the phone, the Call Manager will send an
135 * Open Receive Channel message to the phone to let the caller know someone
136 * has answered. The phone then sends back an Open Receive Channel
137 * Acknowledgement. In this packet, the phone sends its IP address again,
138 * and the UDP port over which the voice traffic should flow. These values
139 * need translation. Right after the Open Receive Channel Acknowledgement,
140 * the Call Manager sends a Start Media Transmission message indicating the
141 * call is connected. This message contains the IP address and UDP port
142 * number of the remote (called) party. Once this message is translated, the
143 * call can commence. The called part sends the first UDP packet to the
144 * calling phone at the pre-arranged UDP port in the Open Receive Channel
145 * Acknowledgement.
146 *
147 * Skinny is a Cisco-proprietary protocol and is a trademark of Cisco Systems,
148 * Inc. All rights reserved.
149*/
150
151/* #define LIBALIAS_DEBUG 1 */
152
153/* Message types that need translating */
154#define REG_MSG 0x00000001
155#define IP_PORT_MSG 0x00000002
156#define OPNRCVCH_ACK 0x00000022
157#define START_MEDIATX 0x0000008a
158
159struct skinny_header {
160 u_int32_t len;
161 u_int32_t reserved;
162 u_int32_t msgId;
163};
164
165struct RegisterMessage {
166 u_int32_t msgId;
167 char devName [16];
168 u_int32_t uid;
169 u_int32_t instance;
170 u_int32_t ipAddr;
171 u_char devType;
172 u_int32_t maxStreams;
173};
174
175struct IpPortMessage {
176 u_int32_t msgId;
177 u_int32_t stationIpPort; /* Note: Skinny uses 32-bit port
178 * numbers */
179};
180
181struct OpenReceiveChannelAck {
182 u_int32_t msgId;
183 u_int32_t status;
184 u_int32_t ipAddr;
185 u_int32_t port;
186 u_int32_t passThruPartyID;
187};
188
189struct StartMediaTransmission {
190 u_int32_t msgId;
191 u_int32_t conferenceID;
192 u_int32_t passThruPartyID;
193 u_int32_t remoteIpAddr;
194 u_int32_t remotePort;
195 u_int32_t MSPacket;
196 u_int32_t payloadCap;
197 u_int32_t precedence;
198 u_int32_t silenceSuppression;
199 u_short maxFramesPerPacket;
200 u_int32_t G723BitRate;
201};
202
203typedef enum {
204 ClientToServer = 0,
205 ServerToClient = 1
206} ConvDirection;
207
208
209static int
210alias_skinny_reg_msg(struct RegisterMessage *reg_msg, struct ip *pip,
211 struct tcphdr *tc, struct alias_link *lnk,
212 ConvDirection direction)
213{
214 (void)direction;
215
216 reg_msg->ipAddr = (u_int32_t) GetAliasAddress(lnk).s_addr;
217
218 tc->th_sum = 0;
219#ifdef _KERNEL
220 tc->th_x2 = 1;
221#else
222 tc->th_sum = TcpChecksum(pip);
223#endif
224
225 return (0);
226}
227
228static int
229alias_skinny_startmedia(struct StartMediaTransmission *start_media,
230 struct ip *pip, struct tcphdr *tc,
231 struct alias_link *lnk, u_int32_t localIpAddr,
232 ConvDirection direction)
233{
234 struct in_addr dst, src;
235
236 (void)pip;
237 (void)tc;
238 (void)lnk;
239 (void)direction;
240
241 dst.s_addr = start_media->remoteIpAddr;
242 src.s_addr = localIpAddr;
243
244 /*
245 * XXX I should probably handle in bound global translations as
246 * well.
247 */
248
249 return (0);
250}
251
252static int
253alias_skinny_port_msg(struct IpPortMessage *port_msg, struct ip *pip,
254 struct tcphdr *tc, struct alias_link *lnk,
255 ConvDirection direction)
256{
257 (void)direction;
258
259 port_msg->stationIpPort = (u_int32_t) ntohs(GetAliasPort(lnk));
260
261 tc->th_sum = 0;
262#ifdef _KERNEL
263 tc->th_x2 = 1;
264#else
265 tc->th_sum = TcpChecksum(pip);
266#endif
267 return (0);
268}
269
270static int
271alias_skinny_opnrcvch_ack(struct libalias *la, struct OpenReceiveChannelAck *opnrcvch_ack,
272 struct ip *pip, struct tcphdr *tc,
273 struct alias_link *lnk, u_int32_t * localIpAddr,
274 ConvDirection direction)
275{
276 struct in_addr null_addr;
277 struct alias_link *opnrcv_lnk;
278 u_int32_t localPort;
279
280 (void)lnk;
281 (void)direction;
282
283 *localIpAddr = (u_int32_t) opnrcvch_ack->ipAddr;
284 localPort = opnrcvch_ack->port;
285
286 null_addr.s_addr = INADDR_ANY;
287 opnrcv_lnk = FindUdpTcpOut(la, pip->ip_src, null_addr,
288 htons((u_short) opnrcvch_ack->port), 0,
289 IPPROTO_UDP, 1);
290 opnrcvch_ack->ipAddr = (u_int32_t) GetAliasAddress(opnrcv_lnk).s_addr;
291 opnrcvch_ack->port = (u_int32_t) ntohs(GetAliasPort(opnrcv_lnk));
292
293 tc->th_sum = 0;
294#ifdef _KERNEL
295 tc->th_x2 = 1;
296#else
297 tc->th_sum = TcpChecksum(pip);
298#endif
299 return (0);
300}
301
302static void
303AliasHandleSkinny(struct libalias *la, struct ip *pip, struct alias_link *lnk)
304{
305 size_t hlen, tlen, dlen;
306 struct tcphdr *tc;
307 u_int32_t msgId, t, len, lip;
308 struct skinny_header *sd;
309 size_t orig_len, skinny_hdr_len = sizeof(struct skinny_header);
310 ConvDirection direction;
311
312 lip = -1;
313 tc = (struct tcphdr *)ip_next(pip);
314 hlen = (pip->ip_hl + tc->th_off) << 2;
315 tlen = ntohs(pip->ip_len);
316 dlen = tlen - hlen;
317
318 sd = (struct skinny_header *)tcp_next(tc);
319
320 /*
321 * XXX This direction is reserved for future use. I still need to
322 * handle the scenario where the call manager is on the inside, and
323 * the calling phone is on the global outside.
324 */
325 if (ntohs(tc->th_dport) == la->skinnyPort) {
326 direction = ClientToServer;
327 } else if (ntohs(tc->th_sport) == la->skinnyPort) {
328 direction = ServerToClient;
329 } else {
330#ifdef LIBALIAS_DEBUG
331 fprintf(stderr,
332 "PacketAlias/Skinny: Invalid port number, not a Skinny packet\n");
333#endif
334 return;
335 }
336
337 orig_len = dlen;
338 /*
339 * Skinny packets can contain many messages. We need to loop
340 * through the packet using len to determine message boundaries.
341 * This comes into play big time with port messages being in the
342 * same packet as register messages. Also, open receive channel
343 * acks are usually buried in a packet some 400 bytes long.
344 */
345 while (dlen >= skinny_hdr_len) {
346 len = (sd->len);
347 msgId = (sd->msgId);
348 t = len;
349
350 if (t > orig_len || t > dlen) {
351#ifdef LIBALIAS_DEBUG
352 fprintf(stderr,
353 "PacketAlias/Skinny: Not a skinny packet, invalid length \n");
354#endif
355 return;
356 }
357 switch (msgId) {
358 case REG_MSG: {
359 struct RegisterMessage *reg_mesg;
360
361 if (len < (int)sizeof(struct RegisterMessage)) {
362#ifdef LIBALIAS_DEBUG
363 fprintf(stderr,
364 "PacketAlias/Skinny: Not a skinny packet, bad registration message\n");
365#endif
366 return;
367 }
368 reg_mesg = (struct RegisterMessage *)&sd->msgId;
369#ifdef LIBALIAS_DEBUG
370 fprintf(stderr,
371 "PacketAlias/Skinny: Received a register message");
372#endif
373 alias_skinny_reg_msg(reg_mesg, pip, tc, lnk, direction);
374 break;
375 }
376 case IP_PORT_MSG: {
377 struct IpPortMessage *port_mesg;
378
379 if (len < (int)sizeof(struct IpPortMessage)) {
380#ifdef LIBALIAS_DEBUG
381 fprintf(stderr,
382 "PacketAlias/Skinny: Not a skinny packet, port message\n");
383#endif
384 return;
385 }
386#ifdef LIBALIAS_DEBUG
387 fprintf(stderr,
388 "PacketAlias/Skinny: Received ipport message\n");
389#endif
390 port_mesg = (struct IpPortMessage *)&sd->msgId;
391 alias_skinny_port_msg(port_mesg, pip, tc, lnk, direction);
392 break;
393 }
394 case OPNRCVCH_ACK: {
395 struct OpenReceiveChannelAck *opnrcvchn_ack;
396
397 if (len < (int)sizeof(struct OpenReceiveChannelAck)) {
398#ifdef LIBALIAS_DEBUG
399 fprintf(stderr,
400 "PacketAlias/Skinny: Not a skinny packet, packet,OpnRcvChnAckMsg\n");
401#endif
402 return;
403 }
404#ifdef LIBALIAS_DEBUG
405 fprintf(stderr,
406 "PacketAlias/Skinny: Received open rcv channel msg\n");
407#endif
408 opnrcvchn_ack = (struct OpenReceiveChannelAck *)&sd->msgId;
409 alias_skinny_opnrcvch_ack(la, opnrcvchn_ack, pip, tc, lnk, &lip, direction);
410 break;
411 }
412 case START_MEDIATX: {
413 struct StartMediaTransmission *startmedia_tx;
414
415 if (len < (int)sizeof(struct StartMediaTransmission)) {
416#ifdef LIBALIAS_DEBUG
417 fprintf(stderr,
418 "PacketAlias/Skinny: Not a skinny packet,StartMediaTx Message\n");
419#endif
420 return;
421 }
422 if (lip == -1) {
423#ifdef LIBALIAS_DEBUG
424 fprintf(stderr,
425 "PacketAlias/Skinny: received a"
426 " packet,StartMediaTx Message before"
427 " packet,OpnRcvChnAckMsg\n"
428#endif
429 return;
430 }
431
432#ifdef LIBALIAS_DEBUG
433 fprintf(stderr,
434 "PacketAlias/Skinny: Received start media trans msg\n");
435#endif
436 startmedia_tx = (struct StartMediaTransmission *)&sd->msgId;
437 alias_skinny_startmedia(startmedia_tx, pip, tc, lnk, lip, direction);
438 break;
439 }
440 default:
441 break;
442 }
443 /* Place the pointer at the next message in the packet. */
444 dlen -= len + (skinny_hdr_len - sizeof(msgId));
445 sd = (struct skinny_header *)(((char *)&sd->msgId) + len);
446 }
447}