blob: 7f94b97b1e7d32ef38d272001eb4726aa67b95ce [file] [log] [blame]
Harald Welte24a655f2010-04-30 19:54:29 +02001/* GPRS Networks Service (NS) messages on the Gb interfacebvci = msgb_bvci(msg);
Harald Welte9ba50052010-03-14 15:45:01 +08002 * 3GPP TS 08.16 version 8.0.1 Release 1999 / ETSI TS 101 299 V8.0.1 (2002-05) */
3
Harald Weltef030b212010-04-26 19:18:54 +02004/* (C) 2009-2010 by Harald Welte <laforge@gnumonks.org>
Harald Welte9ba50052010-03-14 15:45:01 +08005 *
6 * All Rights Reserved
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 */
23
24/* Some introduction into NS: NS is used typically on top of frame relay,
25 * but in the ip.access world it is encapsulated in UDP packets. It serves
26 * as an intermediate shim betwen BSSGP and the underlying medium. It doesn't
27 * do much, apart from providing congestion notification and status indication.
28 *
29 * Terms:
30 * NS Network Service
31 * NSVC NS Virtual Connection
32 * NSEI NS Entity Identifier
33 * NSVL NS Virtual Link
34 * NSVLI NS Virtual Link Identifier
35 * BVC BSSGP Virtual Connection
36 * BVCI BSSGP Virtual Connection Identifier
37 * NSVCG NS Virtual Connection Goup
38 * Blocked NS-VC cannot be used for user traffic
39 * Alive Ability of a NS-VC to provide communication
40 *
41 * There can be multiple BSSGP virtual connections over one (group of) NSVC's. BSSGP will
42 * therefore identify the BSSGP virtual connection by a BVCI passed down to NS.
43 * NS then has to firgure out which NSVC's are responsible for this BVCI.
44 * Those mappings are administratively configured.
45 */
46
47#include <stdlib.h>
48#include <unistd.h>
49#include <errno.h>
50#include <sys/types.h>
51
52#include <arpa/inet.h>
53
54#include <openbsc/gsm_data.h>
55#include <osmocore/msgb.h>
56#include <osmocore/tlv.h>
57#include <osmocore/talloc.h>
Harald Weltef030b212010-04-26 19:18:54 +020058#include <osmocore/select.h>
Harald Welte9ba50052010-03-14 15:45:01 +080059#include <openbsc/debug.h>
60#include <openbsc/gprs_ns.h>
61#include <openbsc/gprs_bssgp.h>
62
63#define NS_ALLOC_SIZE 1024
64
65static const struct tlv_definition ns_att_tlvdef = {
66 .def = {
67 [NS_IE_CAUSE] = { TLV_TYPE_TvLV, 0 },
68 [NS_IE_VCI] = { TLV_TYPE_TvLV, 0 },
69 [NS_IE_PDU] = { TLV_TYPE_TvLV, 0 },
70 [NS_IE_BVCI] = { TLV_TYPE_TvLV, 0 },
71 [NS_IE_NSEI] = { TLV_TYPE_TvLV, 0 },
72 },
73};
74
Harald Weltef030b212010-04-26 19:18:54 +020075/* Lookup struct gprs_nsvc based on NSVCI */
76static struct gprs_nsvc *nsvc_by_nsvci(struct gprs_ns_inst *nsi,
77 u_int16_t nsvci)
78{
79 struct gprs_nsvc *nsvc;
80 llist_for_each_entry(nsvc, &nsi->gprs_nsvcs, list) {
81 if (nsvc->nsvci == nsvci)
82 return nsvc;
83 }
84 return NULL;
85}
86
Harald Welte24a655f2010-04-30 19:54:29 +020087/* Lookup struct gprs_nsvc based on NSVCI */
88static struct gprs_nsvc *nsvc_by_nsei(struct gprs_ns_inst *nsi,
89 u_int16_t nsei)
90{
91 struct gprs_nsvc *nsvc;
92 llist_for_each_entry(nsvc, &nsi->gprs_nsvcs, list) {
93 if (nsvc->nsei == nsei)
94 return nsvc;
95 }
96 return NULL;
97}
98
99
Harald Weltef030b212010-04-26 19:18:54 +0200100/* Lookup struct gprs_nsvc based on remote peer socket addr */
101static struct gprs_nsvc *nsvc_by_rem_addr(struct gprs_ns_inst *nsi,
102 struct sockaddr_in *sin)
103{
104 struct gprs_nsvc *nsvc;
105 llist_for_each_entry(nsvc, &nsi->gprs_nsvcs, list) {
106 if (!memcmp(&nsvc->ip.bts_addr, sin, sizeof(*sin)))
107 return nsvc;
108 }
109 return NULL;
110}
111
112static struct gprs_nsvc *nsvc_create(struct gprs_ns_inst *nsi, u_int16_t nsvci)
113{
114 struct gprs_nsvc *nsvc;
115
116 nsvc = talloc_zero(nsi, struct gprs_nsvc);
117 nsvc->nsvci = nsvci;
118 /* before RESET procedure: BLOCKED and DEAD */
119 nsvc->state = NSE_S_BLOCKED;
120 nsvc->nsi = nsi;
121 llist_add(&nsvc->list, &nsi->gprs_nsvcs);
122
123 return nsvc;
124}
Harald Welte9ba50052010-03-14 15:45:01 +0800125
126/* Section 10.3.2, Table 13 */
Harald Welte2577d412010-05-02 09:37:45 +0200127static const struct value_string ns_cause_str[] = {
128 { NS_CAUSE_TRANSIT_FAIL, "Transit network failure" },
129 { NS_CAUSE_OM_INTERVENTION, "O&M intervention" },
130 { NS_CAUSE_EQUIP_FAIL, "Equipment failure" },
131 { NS_CAUSE_NSVC_BLOCKED, "NS-VC blocked" },
132 { NS_CAUSE_NSVC_UNKNOWN, "NS-VC unknown" },
133 { NS_CAUSE_BVCI_UNKNOWN, "BVCI unknown" },
134 { NS_CAUSE_SEM_INCORR_PDU, "Semantically incorrect PDU" },
135 { NS_CAUSE_PDU_INCOMP_PSTATE, "PDU not compatible with protocol state" },
136 { NS_CAUSE_PROTO_ERR_UNSPEC, "Protocol error }, unspecified" },
137 { NS_CAUSE_INVAL_ESSENT_IE, "Invalid essential IE" },
138 { NS_CAUSE_MISSING_ESSENT_IE, "Missing essential IE" },
139 { 0, NULL }
Harald Welte9ba50052010-03-14 15:45:01 +0800140};
141
Harald Welte2577d412010-05-02 09:37:45 +0200142const char *gprs_ns_cause_str(enum ns_cause cause)
Harald Welte9ba50052010-03-14 15:45:01 +0800143{
Harald Welte2577d412010-05-02 09:37:45 +0200144 return get_value_string(ns_cause_str, cause);
Harald Welte9ba50052010-03-14 15:45:01 +0800145}
146
Harald Welte24a655f2010-04-30 19:54:29 +0200147static int nsip_sendmsg(struct gprs_nsvc *nsvc, struct msgb *msg);
Harald Weltef030b212010-04-26 19:18:54 +0200148
Harald Welte24a655f2010-04-30 19:54:29 +0200149static int gprs_ns_tx(struct gprs_nsvc *nsvc, struct msgb *msg)
Harald Welte9ba50052010-03-14 15:45:01 +0800150{
Harald Weltef030b212010-04-26 19:18:54 +0200151 int ret;
152
153 switch (nsvc->nsi->ll) {
154 case GPRS_NS_LL_UDP:
Harald Welte24a655f2010-04-30 19:54:29 +0200155 ret = nsip_sendmsg(nsvc, msg);
Harald Weltef030b212010-04-26 19:18:54 +0200156 break;
157 default:
158 LOGP(DGPRS, LOGL_ERROR, "unsupported NS linklayer %u\n", nsvc->nsi->ll);
159 msgb_free(msg);
160 ret = -EIO;
161 break;
162 }
163 return ret;
Harald Welte9ba50052010-03-14 15:45:01 +0800164}
165
Harald Weltec5478482010-03-18 00:01:43 +0800166static int gprs_ns_tx_simple(struct gprs_nsvc *nsvc, u_int8_t pdu_type)
Harald Welte9ba50052010-03-14 15:45:01 +0800167{
168 struct msgb *msg = msgb_alloc(NS_ALLOC_SIZE, "GPRS/NS");
169 struct gprs_ns_hdr *nsh;
170
171 if (!msg)
172 return -ENOMEM;
173
174 nsh = (struct gprs_ns_hdr *) msgb_put(msg, sizeof(*nsh));
175
176 nsh->pdu_type = pdu_type;
177
Harald Welte24a655f2010-04-30 19:54:29 +0200178 return gprs_ns_tx(nsvc, msg);
Harald Welte9ba50052010-03-14 15:45:01 +0800179}
180
181#define NS_TIMER_ALIVE 3, 0 /* after 3 seconds without response, we retry */
182#define NS_TIMER_TEST 30, 0 /* every 10 seconds we check if the BTS is still alive */
183#define NS_ALIVE_RETRIES 10 /* after 3 failed retransmit we declare BTS as dead */
184
185static void gprs_ns_alive_cb(void *data)
186{
187 struct gprs_nsvc *nsvc = data;
188
189 if (nsvc->timer_is_tns_alive) {
190 /* Tns-alive case: we expired without response ! */
191 nsvc->alive_retries++;
192 if (nsvc->alive_retries > NS_ALIVE_RETRIES) {
193 /* mark as dead and blocked */
194 nsvc->state = NSE_S_BLOCKED;
195 DEBUGP(DGPRS, "Tns-alive more then %u retries, "
196 " blocking NS-VC\n", NS_ALIVE_RETRIES);
197 /* FIXME: inform higher layers */
198 return;
199 }
200 } else {
201 /* Tns-test case: send NS-ALIVE PDU */
Harald Weltec5478482010-03-18 00:01:43 +0800202 gprs_ns_tx_simple(nsvc, NS_PDUT_ALIVE);
Harald Welte9ba50052010-03-14 15:45:01 +0800203 /* start Tns-alive timer */
204 nsvc->timer_is_tns_alive = 1;
205 }
206 bsc_schedule_timer(&nsvc->alive_timer, NS_TIMER_ALIVE);
207}
208
209/* Section 9.2.6 */
Harald Weltec5478482010-03-18 00:01:43 +0800210static int gprs_ns_tx_reset_ack(struct gprs_nsvc *nsvc)
Harald Welte9ba50052010-03-14 15:45:01 +0800211{
212 struct msgb *msg = msgb_alloc(NS_ALLOC_SIZE, "GPRS/NS");
213 struct gprs_ns_hdr *nsh;
Harald Weltec5478482010-03-18 00:01:43 +0800214 u_int16_t nsvci, nsei;
Harald Welte9ba50052010-03-14 15:45:01 +0800215
216 if (!msg)
217 return -ENOMEM;
218
Harald Weltec5478482010-03-18 00:01:43 +0800219 nsvci = htons(nsvc->nsvci);
220 nsei = htons(nsvc->nsei);
Harald Welte9ba50052010-03-14 15:45:01 +0800221
222 nsh = (struct gprs_ns_hdr *) msgb_put(msg, sizeof(*nsh));
223
224 nsh->pdu_type = NS_PDUT_RESET_ACK;
225
Harald Weltec5478482010-03-18 00:01:43 +0800226 DEBUGP(DGPRS, "nsvci=%u, nsei=%u\n", nsvc->nsvci, nsvc->nsei);
227
Harald Welte9ba50052010-03-14 15:45:01 +0800228 msgb_tvlv_put(msg, NS_IE_VCI, 2, (u_int8_t *)&nsvci);
229 msgb_tvlv_put(msg, NS_IE_NSEI, 2, (u_int8_t *)&nsei);
230
Harald Welte24a655f2010-04-30 19:54:29 +0200231 return gprs_ns_tx(nsvc, msg);
Harald Welte9ba50052010-03-14 15:45:01 +0800232}
233
Harald Welte24a655f2010-04-30 19:54:29 +0200234/* Section 9.2.10: transmit side / NS-UNITDATA-REQUEST primitive */
235int gprs_ns_sendmsg(struct gprs_ns_inst *nsi, struct msgb *msg)
Harald Welte9ba50052010-03-14 15:45:01 +0800236{
Harald Welte24a655f2010-04-30 19:54:29 +0200237 struct gprs_nsvc *nsvc;
Harald Welte9ba50052010-03-14 15:45:01 +0800238 struct gprs_ns_hdr *nsh;
Harald Welte24a655f2010-04-30 19:54:29 +0200239 u_int16_t bvci = msgb_bvci(msg);
240
241 nsvc = nsvc_by_nsei(nsi, msgb_nsei(msg));
242 if (!nsvc) {
243 DEBUGP(DGPRS, "Unable to resolve NSEI %u to NS-VC!\n", msgb_nsei(msg));
244 return -EINVAL;
245 }
Harald Welte9ba50052010-03-14 15:45:01 +0800246
247 nsh = (struct gprs_ns_hdr *) msgb_push(msg, sizeof(*nsh) + 3);
248 if (!nsh) {
249 DEBUGP(DGPRS, "Not enough headroom for NS header\n");
250 return -EIO;
251 }
252
253 nsh->pdu_type = NS_PDUT_UNITDATA;
254 /* spare octet in data[0] */
255 nsh->data[1] = bvci >> 8;
256 nsh->data[2] = bvci & 0xff;
257
Harald Welte24a655f2010-04-30 19:54:29 +0200258 return gprs_ns_tx(nsvc, msg);
Harald Welte9ba50052010-03-14 15:45:01 +0800259}
260
261/* Section 9.2.10: receive side */
Harald Welte24a655f2010-04-30 19:54:29 +0200262static int gprs_ns_rx_unitdata(struct gprs_nsvc *nsvc, struct msgb *msg)
Harald Welte9ba50052010-03-14 15:45:01 +0800263{
264 struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *)msg->l2h;
265 u_int16_t bvci;
266
267 /* spare octet in data[0] */
268 bvci = nsh->data[1] << 8 | nsh->data[2];
269 msg->l3h = &nsh->data[3];
270
271 /* call upper layer (BSSGP) */
Harald Weltef030b212010-04-26 19:18:54 +0200272 return nsvc->nsi->cb(GPRS_NS_EVT_UNIT_DATA, nsvc, msg, bvci);
Harald Welte9ba50052010-03-14 15:45:01 +0800273}
274
275/* Section 9.2.7 */
Harald Welte24a655f2010-04-30 19:54:29 +0200276static int gprs_ns_rx_status(struct gprs_nsvc *nsvc, struct msgb *msg)
Harald Welte9ba50052010-03-14 15:45:01 +0800277{
Harald Weltef030b212010-04-26 19:18:54 +0200278 struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h;
Harald Welte9ba50052010-03-14 15:45:01 +0800279 struct tlv_parsed tp;
280 u_int8_t cause;
281 int rc;
282
283 DEBUGP(DGPRS, "NS STATUS ");
284
285 rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data, msgb_l2len(msg), 0, 0);
286
287 if (!TLVP_PRESENT(&tp, NS_IE_CAUSE)) {
288 DEBUGPC(DGPRS, "missing cause IE\n");
289 return -EINVAL;
290 }
291
292 cause = *TLVP_VAL(&tp, NS_IE_CAUSE);
293 DEBUGPC(DGPRS, "cause=%s\n", gprs_ns_cause_str(cause));
294
295 return 0;
296}
297
298/* Section 7.3 */
Harald Welte24a655f2010-04-30 19:54:29 +0200299static int gprs_ns_rx_reset(struct gprs_nsvc *nsvc, struct msgb *msg)
Harald Welte9ba50052010-03-14 15:45:01 +0800300{
301 struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h;
Harald Welte9ba50052010-03-14 15:45:01 +0800302 struct tlv_parsed tp;
303 u_int8_t *cause;
304 u_int16_t *nsvci, *nsei;
305 int rc;
306
307 DEBUGP(DGPRS, "NS RESET ");
308
309 rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data, msgb_l2len(msg), 0, 0);
310
311 if (!TLVP_PRESENT(&tp, NS_IE_CAUSE) ||
312 !TLVP_PRESENT(&tp, NS_IE_VCI) ||
313 !TLVP_PRESENT(&tp, NS_IE_NSEI)) {
314 /* FIXME: respond with NS_CAUSE_MISSING_ESSENT_IE */
315 DEBUGPC(DGPRS, "Missing mandatory IE\n");
316 return -EINVAL;
317 }
318
319 cause = (u_int8_t *) TLVP_VAL(&tp, NS_IE_CAUSE);
320 nsvci = (u_int16_t *) TLVP_VAL(&tp, NS_IE_VCI);
321 nsei = (u_int16_t *) TLVP_VAL(&tp, NS_IE_NSEI);
322
Harald Weltec5478482010-03-18 00:01:43 +0800323 nsvc->state = NSE_S_BLOCKED | NSE_S_ALIVE;
324 nsvc->nsei = ntohs(*nsei);
325 nsvc->nsvci = ntohs(*nsvci);
Harald Welte9ba50052010-03-14 15:45:01 +0800326
327 DEBUGPC(DGPRS, "cause=%s, NSVCI=%u, NSEI=%u\n",
Harald Weltec5478482010-03-18 00:01:43 +0800328 gprs_ns_cause_str(*cause), nsvc->nsvci, nsvc->nsei);
Harald Welte9ba50052010-03-14 15:45:01 +0800329
330 /* mark the NS-VC as blocked and alive */
Harald Welte9ba50052010-03-14 15:45:01 +0800331 /* start the test procedure */
332 nsvc->alive_timer.cb = gprs_ns_alive_cb;
333 nsvc->alive_timer.data = nsvc;
334 bsc_schedule_timer(&nsvc->alive_timer, NS_TIMER_ALIVE);
335
Harald Weltec5478482010-03-18 00:01:43 +0800336 return gprs_ns_tx_reset_ack(nsvc);
Harald Welte9ba50052010-03-14 15:45:01 +0800337}
338
339/* main entry point, here incoming NS frames enter */
Harald Weltef030b212010-04-26 19:18:54 +0200340int gprs_ns_rcvmsg(struct gprs_ns_inst *nsi, struct msgb *msg,
341 struct sockaddr_in *saddr)
Harald Welte9ba50052010-03-14 15:45:01 +0800342{
343 struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h;
Harald Weltef030b212010-04-26 19:18:54 +0200344 struct gprs_nsvc *nsvc;
Harald Welte9ba50052010-03-14 15:45:01 +0800345 int rc = 0;
346
Harald Weltef030b212010-04-26 19:18:54 +0200347 /* look up the NSVC based on source address */
348 nsvc = nsvc_by_rem_addr(nsi, saddr);
349 if (!nsvc) {
350 /* Only the RESET procedure creates a new NSVC */
351 if (nsh->pdu_type != NS_PDUT_RESET)
352 return -EIO;
353 nsvc = nsvc_create(nsi, 0xffff);
354 nsvc->ip.bts_addr = *saddr;
Harald Welte24a655f2010-04-30 19:54:29 +0200355 rc = gprs_ns_rx_reset(nsvc, msg);
Harald Weltef030b212010-04-26 19:18:54 +0200356 return rc;
357 }
Harald Welte24a655f2010-04-30 19:54:29 +0200358 msgb_nsei(msg) = nsvc->nsei;
Harald Weltec5478482010-03-18 00:01:43 +0800359
Harald Welte9ba50052010-03-14 15:45:01 +0800360 switch (nsh->pdu_type) {
361 case NS_PDUT_ALIVE:
362 /* remote end inquires whether we're still alive,
363 * we need to respond with ALIVE_ACK */
Harald Weltec5478482010-03-18 00:01:43 +0800364 rc = gprs_ns_tx_simple(nsvc, NS_PDUT_ALIVE_ACK);
Harald Welte9ba50052010-03-14 15:45:01 +0800365 break;
366 case NS_PDUT_ALIVE_ACK:
367 /* stop Tns-alive */
368 bsc_del_timer(&nsvc->alive_timer);
369 /* start Tns-test */
370 nsvc->timer_is_tns_alive = 0;
371 bsc_schedule_timer(&nsvc->alive_timer, NS_TIMER_TEST);
372 break;
373 case NS_PDUT_UNITDATA:
374 /* actual user data */
Harald Welte24a655f2010-04-30 19:54:29 +0200375 rc = gprs_ns_rx_unitdata(nsvc, msg);
Harald Welte9ba50052010-03-14 15:45:01 +0800376 break;
377 case NS_PDUT_STATUS:
Harald Welte24a655f2010-04-30 19:54:29 +0200378 rc = gprs_ns_rx_status(nsvc, msg);
Harald Welte9ba50052010-03-14 15:45:01 +0800379 break;
380 case NS_PDUT_RESET:
Harald Welte24a655f2010-04-30 19:54:29 +0200381 rc = gprs_ns_rx_reset(nsvc, msg);
Harald Welte9ba50052010-03-14 15:45:01 +0800382 break;
383 case NS_PDUT_RESET_ACK:
Harald Weltef030b212010-04-26 19:18:54 +0200384 DEBUGP(DGPRS, "NS RESET ACK\n");
385 /* mark remote NS-VC as blocked + active */
386 nsvc->remote_state = NSE_S_BLOCKED | NSE_S_ALIVE;
Harald Welte9ba50052010-03-14 15:45:01 +0800387 break;
388 case NS_PDUT_UNBLOCK:
389 /* Section 7.2: unblocking procedure */
390 DEBUGP(DGPRS, "NS UNBLOCK\n");
391 nsvc->state &= ~NSE_S_BLOCKED;
Harald Weltec5478482010-03-18 00:01:43 +0800392 rc = gprs_ns_tx_simple(nsvc, NS_PDUT_UNBLOCK_ACK);
Harald Welte9ba50052010-03-14 15:45:01 +0800393 break;
394 case NS_PDUT_UNBLOCK_ACK:
Harald Weltef030b212010-04-26 19:18:54 +0200395 DEBUGP(DGPRS, "NS UNBLOCK ACK\n");
396 /* mark remote NS-VC as unblocked + active */
397 nsvc->remote_state = NSE_S_ALIVE;
Harald Welte9ba50052010-03-14 15:45:01 +0800398 break;
399 case NS_PDUT_BLOCK:
400 DEBUGP(DGPRS, "NS BLOCK\n");
401 nsvc->state |= NSE_S_BLOCKED;
Harald Weltec5478482010-03-18 00:01:43 +0800402 rc = gprs_ns_tx_simple(nsvc, NS_PDUT_UNBLOCK_ACK);
Harald Welte9ba50052010-03-14 15:45:01 +0800403 break;
404 case NS_PDUT_BLOCK_ACK:
Harald Weltef030b212010-04-26 19:18:54 +0200405 DEBUGP(DGPRS, "NS BLOCK ACK\n");
406 /* mark remote NS-VC as blocked + active */
407 nsvc->remote_state = NSE_S_BLOCKED | NSE_S_ALIVE;
Harald Welte9ba50052010-03-14 15:45:01 +0800408 break;
409 default:
410 DEBUGP(DGPRS, "Unknown NS PDU type 0x%02x\n", nsh->pdu_type);
411 rc = -EINVAL;
412 break;
413 }
414 return rc;
415}
416
Harald Weltef030b212010-04-26 19:18:54 +0200417struct gprs_ns_inst *gprs_ns_instantiate(gprs_ns_cb_t *cb)
418{
419 struct gprs_ns_inst *nsi = talloc_zero(tall_bsc_ctx, struct gprs_ns_inst);
420
421 nsi->cb = cb;
422 INIT_LLIST_HEAD(&nsi->gprs_nsvcs);
423
Harald Welte3771d092010-04-30 20:26:32 +0200424 return nsi;
Harald Weltef030b212010-04-26 19:18:54 +0200425}
426
427void gprs_ns_destroy(struct gprs_ns_inst *nsi)
428{
429 /* FIXME: clear all timers */
430
431 /* recursively free the NSI and all its NSVCs */
432 talloc_free(nsi);
433}
434
435
436/* NS-over-IP code, according to 3GPP TS 48.016 Chapter 6.2
437 * We don't support Size Procedure, Configuration Procedure, ChangeWeight Procedure */
438
439/* Read a single NS-over-IP message */
440static struct msgb *read_nsip_msg(struct bsc_fd *bfd, int *error,
441 struct sockaddr_in *saddr)
442{
443 struct msgb *msg = msgb_alloc(NS_ALLOC_SIZE, "Abis/IP/GPRS-NS");
444 int ret = 0;
445 socklen_t saddr_len = sizeof(*saddr);
446
447 if (!msg) {
448 *error = -ENOMEM;
449 return NULL;
450 }
451
452 ret = recvfrom(bfd->fd, msg->data, NS_ALLOC_SIZE, 0,
453 (struct sockaddr *)saddr, &saddr_len);
454 if (ret < 0) {
455 fprintf(stderr, "recv error %s\n", strerror(errno));
456 msgb_free(msg);
457 *error = ret;
458 return NULL;
459 } else if (ret == 0) {
460 msgb_free(msg);
461 *error = ret;
462 return NULL;
463 }
464
465 msg->l2h = msg->data;
466 msgb_put(msg, ret);
467
468 return msg;
469}
470
471static int handle_nsip_read(struct bsc_fd *bfd)
472{
473 int error;
474 struct sockaddr_in saddr;
475 struct gprs_ns_inst *nsi = bfd->data;
476 struct msgb *msg = read_nsip_msg(bfd, &error, &saddr);
477
478 if (!msg)
479 return error;
480
481 return gprs_ns_rcvmsg(nsi, msg, &saddr);
482}
483
484static int handle_nsip_write(struct bsc_fd *bfd)
485{
486 /* FIXME: actually send the data here instead of nsip_sendmsg() */
487 return -EIO;
488}
489
Harald Welte24a655f2010-04-30 19:54:29 +0200490int nsip_sendmsg(struct gprs_nsvc *nsvc, struct msgb *msg)
Harald Weltef030b212010-04-26 19:18:54 +0200491{
492 int rc;
493 struct gprs_ns_inst *nsi = nsvc->nsi;
494 struct sockaddr_in *daddr = &nsvc->ip.bts_addr;
495
496 rc = sendto(nsi->nsip.fd.fd, msg->data, msg->len, 0,
497 (struct sockaddr *)daddr, sizeof(*daddr));
498
499 talloc_free(msg);
500
501 return rc;
502}
503
504/* UDP Port 23000 carries the LLC-in-BSSGP-in-NS protocol stack */
505static int nsip_fd_cb(struct bsc_fd *bfd, unsigned int what)
506{
507 int rc = 0;
508
509 if (what & BSC_FD_READ)
510 rc = handle_nsip_read(bfd);
511 if (what & BSC_FD_WRITE)
512 rc = handle_nsip_write(bfd);
513
514 return rc;
515}
516
517
518/* FIXME: this is currently in input/ipaccess.c */
519extern int make_sock(struct bsc_fd *bfd, int proto, u_int16_t port,
520 int (*cb)(struct bsc_fd *fd, unsigned int what));
521
522/* Listen for incoming GPRS packets */
523int nsip_listen(struct gprs_ns_inst *nsi, uint16_t udp_port)
524{
525 int ret;
526
527 ret = make_sock(&nsi->nsip.fd, IPPROTO_UDP, udp_port, nsip_fd_cb);
528 if (ret < 0)
529 return ret;
530
531 nsi->ll = GPRS_NS_LL_UDP;
532 nsi->nsip.fd.data = nsi;
533
534 return ret;
535}
Harald Welte3771d092010-04-30 20:26:32 +0200536
537/* Establish a connection (from the BSS) to the SGSN */
538struct gprs_nsvc *nsip_connect(struct gprs_ns_inst *nsi,
Harald Welte1203de32010-05-01 11:28:43 +0200539 struct sockaddr_in *dest, uint16_t nsei,
540 uint16_t nsvci)
Harald Welte3771d092010-04-30 20:26:32 +0200541{
542 struct gprs_nsvc *nsvc;
543
544 nsvc = nsvc_by_rem_addr(nsi, dest);
545 if (!nsvc) {
546 nsvc = nsvc_create(nsi, nsvci);
547 nsvc->ip.bts_addr = *dest;
548 }
Harald Welte1203de32010-05-01 11:28:43 +0200549 nsvc->nsei = nsei;
550 nsvc->nsvci = nsvci;
Harald Welte3771d092010-04-30 20:26:32 +0200551 nsvc->remote_end_is_sgsn = 1;
552
553 /* Initiate a RESET procedure */
554 if (gprs_ns_tx_simple(nsvc, NS_PDUT_RESET) < 0)
555 return NULL;
556 /* FIXME: should we run a timer and re-transmit the reset request? */
557
558 return nsvc;
559}