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osmo-msc/src/libmsc/gsm_04_08.c

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/* GSM Mobile Radio Interface Layer 3 messages on the A-bis interface
* 3GPP TS 04.08 version 7.21.0 Release 1998 / ETSI TS 100 940 V7.21.0 */
/* (C) 2008-2016 by Harald Welte <laforge@gnumonks.org>
* (C) 2008-2012 by Holger Hans Peter Freyther <zecke@selfish.org>
*
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <errno.h>
#include <time.h>
#include <netinet/in.h>
#include <sys/types.h>
#include "config.h"
#include <osmocom/msc/debug.h>
#include <osmocom/msc/gsm_data.h>
#include <osmocom/msc/gsm_04_08.h>
#include <osmocom/msc/signal.h>
#include <osmocom/msc/transaction.h>
#include <osmocom/msc/vlr.h>
#include <osmocom/msc/msc_a.h>
#include <osmocom/gsm/gsm48.h>
#include <osmocom/gsm/gsm_utils.h>
#include <osmocom/gsm/protocol/gsm_04_08.h>
#include <osmocom/core/msgb.h>
#include <osmocom/core/talloc.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/byteswap.h>
#include <osmocom/core/fsm.h>
#include <osmocom/gsm/tlv.h>
#include <osmocom/crypt/auth.h>
#include <osmocom/msc/msub.h>
#include <osmocom/msc/msc_roles.h>
#include <osmocom/msc/call_leg.h>
#include <assert.h>
void *tall_locop_ctx;
void *tall_authciphop_ctx;
static int gsm0408_loc_upd_acc(struct msc_a *msc_a, uint32_t send_tmsi);
/*! Send a simple GSM 04.08 message without any payload
* \param conn Active RAN connection
* \param[in] pdisc Protocol discriminator
* \param[in] msg_type Message type
* \return result of \ref gsm48_conn_sendmsg
*/
int gsm48_tx_simple(struct msc_a *msc_a, uint8_t pdisc, uint8_t msg_type)
{
struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 TX SIMPLE");
struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
gh->proto_discr = pdisc;
gh->msg_type = msg_type;
return msc_a_tx_dtap_to_i(msc_a, msg);
}
/* clear all transactions globally; used in case of MNCC socket disconnect */
void gsm0408_clear_all_trans(struct gsm_network *net, enum trans_type type)
{
struct gsm_trans *trans, *temp;
LOGP(DCC, LOGL_NOTICE, "Clearing all currently active transactions!!!\n");
llist_for_each_entry_safe(trans, temp, &net->trans_list, entry) {
if (trans->type == type) {
trans->callref = 0;
trans_free(trans);
}
}
}
/* Chapter 9.2.14 : Send LOCATION UPDATING REJECT */
static int gsm0408_loc_upd_rej(struct msc_a *msc_a, uint8_t cause)
{
struct msgb *msg;
msg = gsm48_create_loc_upd_rej(cause);
if (!msg) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR, "Failed to create msg for LOCATION UPDATING REJECT.\n");
return -1;
}
LOG_MSC_A_CAT(msc_a, DMM, LOGL_INFO, "LOCATION UPDATING REJECT\n");
return msc_a_tx_dtap_to_i(msc_a, msg);
}
/* Chapter 9.2.13 : Send LOCATION UPDATE ACCEPT */
static int gsm0408_loc_upd_acc(struct msc_a *msc_a, uint32_t send_tmsi)
{
struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 LOC UPD ACC");
struct gsm48_hdr *gh;
struct gsm48_loc_area_id *lai;
struct gsm_network *net = msc_a_net(msc_a);
struct vlr_subscr *vsub = msc_a_vsub(msc_a);
struct osmo_location_area_id laid = {
.plmn = net->plmn,
.lac = vsub->cgi.lai.lac,
};
uint8_t *l;
int rc;
struct osmo_mobile_identity mi = {};
gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
gh->proto_discr = GSM48_PDISC_MM;
gh->msg_type = GSM48_MT_MM_LOC_UPD_ACCEPT;
lai = (struct gsm48_loc_area_id *) msgb_put(msg, sizeof(*lai));
gsm48_generate_lai2(lai, &laid);
if (send_tmsi == GSM_RESERVED_TMSI) {
/* we did not allocate a TMSI to the MS, so we need to
* include the IMSI in order for the MS to delete any
* old TMSI that might still be allocated */
mi.type = GSM_MI_TYPE_IMSI;
OSMO_STRLCPY_ARRAY(mi.imsi, vsub->imsi);
DEBUGP(DMM, "-> %s LOCATION UPDATE ACCEPT\n",
vlr_subscr_name(vsub));
} else {
/* Include the TMSI, which means that the MS will send a
* TMSI REALLOCATION COMPLETE, and we should wait for
* that until T3250 expiration */
mi.type = GSM_MI_TYPE_TMSI;
mi.tmsi = send_tmsi;
DEBUGP(DMM, "-> %s LOCATION UPDATE ACCEPT (TMSI = 0x%08x)\n",
vlr_subscr_name(vsub),
send_tmsi);
}
l = msgb_tl_put(msg, GSM48_IE_MOBILE_ID);
rc = osmo_mobile_identity_encode_msgb(msg, &mi, false);
if (rc < 0) {
msgb_free(msg);
return -EINVAL;
}
*l = rc;
/* TODO: Follow-on proceed */
/* TODO: CTS permission */
/* TODO: Equivalent PLMNs */
/* TODO: Emergency Number List */
/* TODO: Per-MS T3312 */
return msc_a_tx_dtap_to_i(msc_a, msg);
}
/* Transmit Chapter 9.2.10 Identity Request */
static int mm_tx_identity_req(struct msc_a *msc_a, uint8_t id_type)
{
struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 ID REQ");
struct gsm48_hdr *gh;
gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1);
gh->proto_discr = GSM48_PDISC_MM;
gh->msg_type = GSM48_MT_MM_ID_REQ;
gh->data[0] = id_type;
return msc_a_tx_dtap_to_i(msc_a, msg);
}
/* Parse Chapter 9.2.11 Identity Response */
static int mm_rx_id_resp(struct msc_a *msc_a, struct msgb *msg)
{
struct gsm48_hdr *gh = msgb_l3(msg);
uint8_t *mi_data = gh->data+1;
uint8_t mi_len = gh->data[0];
struct vlr_subscr *vsub = msc_a_vsub(msc_a);
struct osmo_mobile_identity mi;
int rc;
if (!vsub) {
LOGP(DMM, LOGL_ERROR,
"Rx MM Identity Response: invalid: no subscriber\n");
return -EINVAL;
}
/* There muct be at least one octet with MI type */
if (!mi_len) {
LOGP(DMM, LOGL_NOTICE, "MM Identity Response contains "
"malformed Mobile Identity\n");
return -EINVAL;
}
rc = osmo_mobile_identity_decode(&mi, mi_data, mi_len, false);
if (rc) {
LOGP(DMM, LOGL_ERROR, "Failure to decode Mobile Identity in MM Identity Response (rc=%d)\n", rc);
return -EINVAL;
}
/* Make sure we got what we expected */
if (mi.type != msc_a->mm_id_req_type) {
LOGP(DMM, LOGL_NOTICE, "MM Identity Response contains unexpected "
"Mobile Identity type %s (extected %s)\n",
gsm48_mi_type_name(mi.type),
gsm48_mi_type_name(msc_a->mm_id_req_type));
return -EINVAL;
}
DEBUGP(DMM, "IDENTITY RESPONSE: %s\n", osmo_mobile_identity_to_str_c(OTC_SELECT, &mi));
osmo_signal_dispatch(SS_SUBSCR, S_SUBSCR_IDENTITY, gh->data);
return vlr_subscr_rx_id_resp(vsub, &mi);
}
/* 9.2.5 CM service accept */
static int msc_gsm48_tx_mm_serv_ack(struct msc_a *msc_a)
{
struct msgb *msg;
struct gsm48_hdr *gh;
msg = gsm48_msgb_alloc_name("GSM 04.08 SERV ACC");
gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
gh->proto_discr = GSM48_PDISC_MM;
gh->msg_type = GSM48_MT_MM_CM_SERV_ACC;
return msc_a_tx_dtap_to_i(msc_a, msg);
}
/* 9.2.6 CM service reject */
static int msc_gsm48_tx_mm_serv_rej(struct msc_a *msc_a,
enum gsm48_reject_value value)
{
struct msgb *msg;
msg = gsm48_create_mm_serv_rej(value);
if (!msg) {
LOGP(DMM, LOGL_ERROR, "Failed to allocate CM Service Reject.\n");
return -1;
}
LOG_MSC_A_CAT(msc_a, DMM, LOGL_DEBUG, "-> CM SERVICE Reject cause: %d\n", value);
return msc_a_tx_dtap_to_i(msc_a, msg);
}
/* Extract the R99 flag from various Complete Level 3 messages. Depending on the Message Type, extract R99 from the
* Classmark Type 1 or the Classmark Type 2. Return 1 for R99, 0 for pre-R99, negative if not a valid Complete Level 3
* message. */
int compl_l3_msg_is_r99(const struct msgb *msg)
{
const struct gsm48_hdr *gh = msgb_l3(msg);
uint8_t pdisc = gsm48_hdr_pdisc(gh);
const struct gsm48_loc_upd_req *lu;
const struct gsm48_imsi_detach_ind *idi;
uint8_t cm2_len;
const struct gsm48_classmark2 *cm2;
switch (pdisc) {
case GSM48_PDISC_MM:
switch (gsm48_hdr_msg_type(gh)) {
case GSM48_MT_MM_LOC_UPD_REQUEST:
lu = (const struct gsm48_loc_upd_req *) gh->data;
return osmo_gsm48_classmark1_is_r99(&lu->classmark1) ? 1 : 0;
case GSM48_MT_MM_CM_SERV_REQ:
case GSM48_MT_MM_CM_REEST_REQ:
break;
case GSM48_MT_MM_IMSI_DETACH_IND:
idi = (const struct gsm48_imsi_detach_ind *) gh->data;
return osmo_gsm48_classmark1_is_r99(&idi->classmark1) ? 1 : 0;
default:
return -1;
}
break;
case GSM48_PDISC_RR:
switch (gsm48_hdr_msg_type(gh)) {
case GSM48_MT_RR_PAG_RESP:
break;
default:
return -1;
}
break;
default:
return -1;
}
/* Both CM Service Request and Paging Response have Classmark Type 2 at the same location: */
cm2_len = gh->data[1];
cm2 = (void*)gh->data+2;
return osmo_gsm48_classmark2_is_r99(cm2, cm2_len) ? 1 : 0;
}
/* Chapter 9.2.15: Receive Location Updating Request.
* Keep this function non-static for direct invocation by unit tests. */
static int mm_rx_loc_upd_req(struct msc_a *msc_a, struct msgb *msg)
{
struct gsm48_hdr *gh = msgb_l3(msg);
struct gsm48_loc_upd_req *lu;
enum vlr_lu_type vlr_lu_type = VLR_LU_TYPE_REGULAR;
uint32_t tmsi;
char *imsi;
struct osmo_location_area_id old_lai;
struct osmo_fsm_inst *lu_fsm;
bool is_utran;
struct gsm_network *net = msc_a_net(msc_a);
struct vlr_subscr *vsub;
struct osmo_mobile_identity mi;
int rc;
rc = osmo_mobile_identity_decode_from_l3(&mi, msg, false);
if (rc) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR,
"Failed to decode Mobile Identity in Location Updating Request\n");
return -EINVAL;
}
lu = (struct gsm48_loc_upd_req *) gh->data;
if (msc_a_is_establishing_auth_ciph(msc_a)) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR,
"Cannot accept another LU, conn already busy establishing authenticity;"
" extraneous LOCATION UPDATING REQUEST: MI=%s LU-type=%s\n",
osmo_mobile_identity_to_str_c(OTC_SELECT, &mi), osmo_lu_type_name(lu->type));
return -EINVAL;
}
if (msc_a_is_accepted(msc_a)) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR,
"Cannot accept another LU, conn already established;"
" extraneous LOCATION UPDATING REQUEST: MI=%s LU-type=%s\n",
osmo_mobile_identity_to_str_c(OTC_SELECT, &mi), osmo_lu_type_name(lu->type));
return -EINVAL;
}
msc_a->complete_layer3_type = COMPLETE_LAYER3_LU;
msub_update_id_from_mi(msc_a->c.msub, &mi);
LOG_MSC_A_CAT(msc_a, DMM, LOGL_DEBUG, "LOCATION UPDATING REQUEST: MI=%s LU-type=%s\n",
osmo_mobile_identity_to_str_c(OTC_SELECT, &mi), osmo_lu_type_name(lu->type));
osmo_signal_dispatch(SS_SUBSCR, S_SUBSCR_IDENTITY, &mi);
switch (lu->type) {
case GSM48_LUPD_NORMAL:
rate_ctr_inc(rate_ctr_group_get_ctr(net->msc_ctrs, MSC_CTR_LOC_UPDATE_TYPE_NORMAL));
vlr_lu_type = VLR_LU_TYPE_REGULAR;
break;
case GSM48_LUPD_IMSI_ATT:
rate_ctr_inc(rate_ctr_group_get_ctr(net->msc_ctrs, MSC_CTR_LOC_UPDATE_TYPE_ATTACH));
vlr_lu_type = VLR_LU_TYPE_IMSI_ATTACH;
break;
case GSM48_LUPD_PERIODIC:
rate_ctr_inc(rate_ctr_group_get_ctr(net->msc_ctrs, MSC_CTR_LOC_UPDATE_TYPE_PERIODIC));
vlr_lu_type = VLR_LU_TYPE_PERIODIC;
break;
}
/* TODO: 10.5.1.6 MS Classmark for UMTS / Classmark 2 */
/* TODO: 10.5.3.14 Additional update parameters (CS fallback calls) */
/* TODO: 10.5.7.8 Device properties */
/* TODO: 10.5.1.15 MS network feature support */
switch (mi.type) {
case GSM_MI_TYPE_IMSI:
tmsi = GSM_RESERVED_TMSI;
imsi = mi.imsi;
break;
case GSM_MI_TYPE_TMSI:
tmsi = mi.tmsi;
imsi = NULL;
break;
default:
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR, "unknown mobile identity type\n");
tmsi = GSM_RESERVED_TMSI;
imsi = NULL;
break;
}
gsm48_decode_lai2(&lu->lai, &old_lai);
LOG_MSC_A_CAT(msc_a, DMM, LOGL_DEBUG, "USIM: old LAI: %s\n", osmo_lai_name(&old_lai));
msc_a_get(msc_a, __func__);
msc_a_get(msc_a, MSC_A_USE_LOCATION_UPDATING);
is_utran = (msc_a->c.ran->type == OSMO_RAT_UTRAN_IU);
lu_fsm = vlr_loc_update(msc_a->c.fi,
MSC_A_EV_AUTHENTICATED, MSC_A_EV_CN_CLOSE, NULL,
net->vlr, msc_a, vlr_lu_type, tmsi, imsi,
&old_lai, &msc_a->via_cell.lai,
is_utran || net->authentication_required,
is_utran ? net->uea_encryption_mask > 0x01 : net->a5_encryption_mask > 0x01,
lu->key_seq,
osmo_gsm48_classmark1_is_r99(&lu->classmark1),
is_utran,
net->vlr->cfg.assign_tmsi);
if (!lu_fsm) {
LOG_MSC_A(msc_a, LOGL_ERROR, "Can't start LU FSM\n");
msc_a_put(msc_a, MSC_A_USE_LOCATION_UPDATING);
msc_a_put(msc_a, __func__);
return 0;
}
/* From vlr_loc_update() we expect an implicit dispatch of
* VLR_ULA_E_UPDATE_LA, and thus we expect msc_vlr_subscr_assoc() to
* already have been called and completed. Has an error occurred? */
vsub = msc_a_vsub(msc_a);
if (!vsub) {
msc_a_put(msc_a, __func__);
return 0;
}
if (vsub->lu_fsm != lu_fsm) {
LOG_MSC_A(msc_a, LOGL_ERROR, "Internal Error during Location Updating attempt\n");
msc_a_release_cn(msc_a);
msc_a_put(msc_a, __func__);
return -EIO;
}
vsub->classmark.classmark1 = lu->classmark1;
vsub->classmark.classmark1_set = true;
msc_a_put(msc_a, __func__);
return 0;
}
/* Turn int into semi-octet representation: 98 => 0x89 */
/* FIXME: libosmocore/libosmogsm */
static uint8_t bcdify(uint8_t value)
{
uint8_t ret;
ret = value / 10;
ret |= (value % 10) << 4;
return ret;
}
/* Generate a message buffer that contains a valid MM info message,
* See also 3GPP TS 24.008, chapter 9.2.15a */
struct msgb *gsm48_create_mm_info(struct gsm_network *net)
{
struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 MM INF");
struct gsm48_hdr *gh;
uint8_t *ptr8;
int name_len, name_pad;
time_t cur_t;
struct tm* gmt_time;
struct tm* local_time;
int tzunits;
int dst = 0;
gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
gh->proto_discr = GSM48_PDISC_MM;
gh->msg_type = GSM48_MT_MM_INFO;
if (net->name_long) {
#if 0
name_len = strlen(net->name_long);
/* 10.5.3.5a */
ptr8 = msgb_put(msg, 3);
ptr8[0] = GSM48_IE_NAME_LONG;
ptr8[1] = name_len*2 +1;
ptr8[2] = 0x90; /* UCS2, no spare bits, no CI */
ptr16 = (uint16_t *) msgb_put(msg, name_len*2);
for (i = 0; i < name_len; i++)
ptr16[i] = htons(net->name_long[i]);
/* FIXME: Use Cell Broadcast, not UCS-2, since
* UCS-2 is only supported by later revisions of the spec */
#endif
name_len = (strlen(net->name_long)*7)/8;
name_pad = (8 - strlen(net->name_long)*7)%8;
if (name_pad > 0)
name_len++;
/* 10.5.3.5a */
ptr8 = msgb_put(msg, 3);
ptr8[0] = GSM48_IE_NAME_LONG;
ptr8[1] = name_len +1;
ptr8[2] = 0x80 | name_pad; /* Cell Broadcast DCS, no CI */
ptr8 = msgb_put(msg, name_len);
gsm_7bit_encode_n(ptr8, name_len, net->name_long, NULL);
}
if (net->name_short) {
#if 0
name_len = strlen(net->name_short);
/* 10.5.3.5a */
ptr8 = (uint8_t *) msgb_put(msg, 3);
ptr8[0] = GSM48_IE_NAME_SHORT;
ptr8[1] = name_len*2 + 1;
ptr8[2] = 0x90; /* UCS2, no spare bits, no CI */
ptr16 = (uint16_t *) msgb_put(msg, name_len*2);
for (i = 0; i < name_len; i++)
ptr16[i] = htons(net->name_short[i]);
#endif
name_len = (strlen(net->name_short)*7)/8;
name_pad = (8 - strlen(net->name_short)*7)%8;
if (name_pad > 0)
name_len++;
/* 10.5.3.5a */
ptr8 = (uint8_t *) msgb_put(msg, 3);
ptr8[0] = GSM48_IE_NAME_SHORT;
ptr8[1] = name_len +1;
ptr8[2] = 0x80 | name_pad; /* Cell Broadcast DCS, no CI */
ptr8 = msgb_put(msg, name_len);
gsm_7bit_encode_n(ptr8, name_len, net->name_short, NULL);
}
/* Section 10.5.3.9 */
cur_t = time(NULL);
gmt_time = gmtime(&cur_t);
ptr8 = msgb_put(msg, 8);
ptr8[0] = GSM48_IE_NET_TIME_TZ;
ptr8[1] = bcdify(gmt_time->tm_year % 100);
ptr8[2] = bcdify(gmt_time->tm_mon + 1);
ptr8[3] = bcdify(gmt_time->tm_mday);
ptr8[4] = bcdify(gmt_time->tm_hour);
ptr8[5] = bcdify(gmt_time->tm_min);
ptr8[6] = bcdify(gmt_time->tm_sec);
if (net->tz.override) {
/* Convert tz.hr and tz.mn to units */
if (net->tz.hr < 0) {
tzunits = ((net->tz.hr/-1)*4);
tzunits = tzunits + (net->tz.mn/15);
ptr8[7] = bcdify(tzunits);
/* Set negative time */
ptr8[7] |= 0x08;
}
else {
tzunits = net->tz.hr*4;
tzunits = tzunits + (net->tz.mn/15);
ptr8[7] = bcdify(tzunits);
}
/* Convert DST value */
if (net->tz.dst >= 0 && net->tz.dst <= 2)
dst = net->tz.dst;
}
else {
/* Need to get GSM offset and convert into 15 min units */
/* This probably breaks if gmtoff returns a value not evenly divisible by 15? */
#ifdef HAVE_TM_GMTOFF_IN_TM
local_time = localtime(&cur_t);
tzunits = (local_time->tm_gmtoff/60)/15;
#else
/* find timezone offset */
time_t utc;
double offsetFromUTC;
utc = mktime(gmt_time);
local_time = localtime(&cur_t);
offsetFromUTC = difftime(cur_t, utc);
if (local_time->tm_isdst)
offsetFromUTC += 3600.0;
tzunits = ((int)offsetFromUTC) / 60 / 15;
#endif
if (tzunits < 0) {
tzunits = tzunits/-1;
ptr8[7] = bcdify(tzunits);
/* Flip it to negative */
ptr8[7] |= 0x08;
}
else
ptr8[7] = bcdify(tzunits);
/* Does not support DST +2 */
if (local_time->tm_isdst)
dst = 1;
}
if (dst) {
ptr8 = msgb_put(msg, 3);
ptr8[0] = GSM48_IE_NET_DST;
ptr8[1] = 1;
ptr8[2] = dst;
}
return msg;
}
/* Section 9.2.15a */
int gsm48_tx_mm_info(struct msc_a *msc_a)
{
struct gsm_network *net = msc_a_net(msc_a);
struct msgb *msg;
msg = gsm48_create_mm_info(net);
LOG_MSC_A(msc_a, LOGL_DEBUG, "Tx MM INFO\n");
return msc_a_tx_dtap_to_i(msc_a, msg);
}
/*! Send an Authentication Request to MS on the given RAN connection
* according to 3GPP/ETSI TS 24.008, Section 9.2.2.
* \param[in] conn Subscriber connection to send on.
* \param[in] rand Random challenge token to send, must be 16 bytes long.
* \param[in] autn r99: In case of UMTS mutual authentication, AUTN token to
* send; must be 16 bytes long, or pass NULL for plain GSM auth.
* \param[in] key_seq auth tuple's sequence number.
*/
int gsm48_tx_mm_auth_req(struct msc_a *msc_a, uint8_t *rand,
uint8_t *autn, int key_seq)
{
struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 AUTH REQ");
struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
struct gsm48_auth_req *ar = (struct gsm48_auth_req *) msgb_put(msg, sizeof(*ar));
DEBUGP(DMM, "Tx AUTH REQ (rand = %s)\n", osmo_hexdump_nospc(rand, 16));
if (autn)
DEBUGP(DMM, " AUTH REQ (autn = %s)\n", osmo_hexdump_nospc(autn, 16));
gh->proto_discr = GSM48_PDISC_MM;
gh->msg_type = GSM48_MT_MM_AUTH_REQ;
ar->key_seq = key_seq;
/* 16 bytes RAND parameters */
osmo_static_assert(sizeof(ar->rand) == 16, sizeof_auth_req_r99_rand);
if (rand)
memcpy(ar->rand, rand, 16);
/* 16 bytes AUTN */
if (autn)
msgb_tlv_put(msg, GSM48_IE_AUTN, 16, autn);
return msc_a_tx_dtap_to_i(msc_a, msg);
}
/* Section 9.2.1 */
int gsm48_tx_mm_auth_rej(struct msc_a *msc_a)
{
LOG_MSC_A_CAT(msc_a, DMM, LOGL_DEBUG, "-> AUTH REJECT\n");
return gsm48_tx_simple(msc_a, GSM48_PDISC_MM, GSM48_MT_MM_AUTH_REJ);
}
static int msc_vlr_tx_cm_serv_rej(void *msc_conn_ref, enum osmo_cm_service_type cm_service_type,
enum gsm48_reject_value cause);
static int cm_serv_reuse_conn(struct msc_a *msc_a, const struct osmo_mobile_identity *mi, enum osmo_cm_service_type cm_serv_type)
{
struct gsm_network *net = msc_a_net(msc_a);
struct vlr_subscr *vsub = msc_a_vsub(msc_a);
switch (mi->type) {
case GSM_MI_TYPE_IMSI:
if (vlr_subscr_matches_imsi(vsub, mi->imsi))
goto accept_reuse;
break;
case GSM_MI_TYPE_TMSI:
if (vlr_subscr_matches_tmsi(vsub, mi->tmsi))
goto accept_reuse;
break;
case GSM_MI_TYPE_IMEI:
if (vlr_subscr_matches_imei(vsub, mi->imei))
goto accept_reuse;
break;
default:
break;
}
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR, "CM Service Request with mismatching mobile identity: %s\n",
osmo_mobile_identity_to_str_c(OTC_SELECT, mi));
msc_vlr_tx_cm_serv_rej(msc_a, cm_serv_type, GSM48_REJECT_ILLEGAL_MS);
return -EINVAL;
accept_reuse:
LOG_MSC_A_CAT(msc_a, DMM, LOGL_DEBUG, "re-using already accepted connection\n");
msc_a_get(msc_a, msc_a_cm_service_type_to_use(cm_serv_type));
msub_update_id(msc_a->c.msub);
return net->vlr->ops.tx_cm_serv_acc(msc_a, cm_serv_type);
}
/*
* Handle CM Service Requests
* a) Verify that the packet is long enough to contain the information
* we require otherwise reject with INCORRECT_MESSAGE
* b) Try to parse the TMSI. If we do not have one reject
* c) Check that we know the subscriber with the TMSI otherwise reject
* with a HLR cause
* d) Set the subscriber on the conn and accept
*
* Keep this function non-static for direct invocation by unit tests.
*/
int gsm48_rx_mm_serv_req(struct msc_a *msc_a, struct msgb *msg)
{
struct gsm_network *net = msc_a_net(msc_a);
struct gsm48_hdr *gh;
struct gsm48_service_request *req;
struct gsm48_classmark2 *cm2;
uint8_t *cm2_buf, cm2_len;
bool is_utran;
struct vlr_subscr *vsub;
struct osmo_mobile_identity mi;
int rc;
/* Make sure that both header and CM Service Request fit into the buffer */
if (msgb_l3len(msg) < sizeof(*gh) + sizeof(*req)) {
LOG_MSC_A(msc_a, LOGL_ERROR, "Rx CM SERVICE REQUEST: wrong message size (%u < %zu)\n",
msgb_l3len(msg), sizeof(*gh) + sizeof(*req));
return msc_gsm48_tx_mm_serv_rej(msc_a, GSM48_REJECT_INCORRECT_MESSAGE);
}
rc = osmo_mobile_identity_decode_from_l3(&mi, msg, false);
if (rc) {
LOG_MSC_A(msc_a, LOGL_ERROR, "Rx CM SERVICE REQUEST: unable to decode Mobile Identity\n");
return msc_gsm48_tx_mm_serv_rej(msc_a, GSM48_REJECT_INCORRECT_MESSAGE);
}
gh = (struct gsm48_hdr *) msgb_l3(msg);
req = (struct gsm48_service_request *) gh->data;
/* Unfortunately in Phase1 the Classmark2 length is variable, so we cannot
* just use gsm48_service_request struct, and need to parse it manually. */
cm2_len = gh->data[1];
cm2_buf = gh->data + 2;
cm2 = (struct gsm48_classmark2 *) cm2_buf;
/* Prevent buffer overrun: check the length of Classmark2 */
if (cm2_buf + cm2_len > msg->tail) {
LOG_MSC_A(msc_a, LOGL_ERROR, "Rx CM SERVICE REQUEST: Classmark2 "
"length=%u is too big\n", cm2_len);
return msc_gsm48_tx_mm_serv_rej(msc_a, GSM48_REJECT_INCORRECT_MESSAGE);
}
if (msc_a_is_establishing_auth_ciph(msc_a)) {
LOG_MSC_A(msc_a, LOGL_ERROR,
"Cannot accept CM Service Request, conn already busy establishing authenticity\n");
return msc_gsm48_tx_mm_serv_rej(msc_a, GSM48_REJECT_CONGESTION);
/* or should we accept and note down the service request anyway? */
}
msc_a->complete_layer3_type = COMPLETE_LAYER3_CM_SERVICE_REQ;
msub_update_id_from_mi(msc_a->c.msub, &mi);
LOG_MSC_A_CAT(msc_a, DMM, LOGL_DEBUG, "Rx CM SERVICE REQUEST cm_service_type=%s\n",
osmo_cm_service_type_name(req->cm_service_type));
switch (mi.type) {
case GSM_MI_TYPE_IMSI:
case GSM_MI_TYPE_TMSI:
/* continue below */
break;
case GSM_MI_TYPE_IMEI:
if (req->cm_service_type == GSM48_CMSERV_EMERGENCY) {
/* We don't do emergency calls by IMEI */
LOG_MSC_A(msc_a, LOGL_NOTICE, "Tx CM SERVICE REQUEST REJECT: "
"emergency services by IMEI are not supported\n");
return msc_gsm48_tx_mm_serv_rej(msc_a, GSM48_REJECT_IMEI_NOT_ACCEPTED);
}
/* fall-through for non-emergency setup */
default:
LOG_MSC_A(msc_a, LOGL_ERROR, "MI type is not expected: %s\n", gsm48_mi_type_name(mi.type));
return msc_gsm48_tx_mm_serv_rej(msc_a, GSM48_REJECT_INCORRECT_MESSAGE);
}
if (!msc_a_cm_service_type_to_use(req->cm_service_type))
return msc_gsm48_tx_mm_serv_rej(msc_a, GSM48_REJECT_SRV_OPT_NOT_SUPPORTED);
if (msc_a_is_accepted(msc_a))
return cm_serv_reuse_conn(msc_a, &mi, req->cm_service_type);
osmo_signal_dispatch(SS_SUBSCR, S_SUBSCR_IDENTITY, &mi);
msc_a_get(msc_a, msc_a_cm_service_type_to_use(req->cm_service_type));
is_utran = (msc_a->c.ran->type == OSMO_RAT_UTRAN_IU);
vlr_proc_acc_req(msc_a->c.fi,
MSC_A_EV_AUTHENTICATED, MSC_A_EV_CN_CLOSE, NULL,
net->vlr, msc_a,
VLR_PR_ARQ_T_CM_SERV_REQ,
req->cm_service_type,
&mi, &msc_a->via_cell.lai,
is_utran || net->authentication_required,
is_utran ? net->uea_encryption_mask > 0x01 : net->a5_encryption_mask > 0x01,
req->cipher_key_seq,
osmo_gsm48_classmark2_is_r99(cm2, cm2_len),
is_utran);
/* From vlr_proc_acc_req() we expect an implicit dispatch of PR_ARQ_E_START we expect
* msc_vlr_subscr_assoc() to already have been called and completed. Has an error occurred? */
vsub = msc_a_vsub(msc_a);
if (!vsub) {
LOG_MSC_A(msc_a, LOGL_ERROR, "subscriber not allowed to do a CM Service Request\n");
return -EIO;
}
vsub->classmark.classmark2 = *cm2;
vsub->classmark.classmark2_len = cm2_len;
return 0;
}
/* Receive a CM Re-establish Request */
static int gsm48_rx_cm_reest_req(struct msc_a *msc_a, struct msgb *msg)
{
struct gsm_network *net = msc_a_net(msc_a);
struct gsm48_hdr *gh;
struct gsm48_service_request *req;
struct gsm48_classmark2 *cm2;
uint8_t *cm2_buf, cm2_len;
bool is_utran;
struct vlr_subscr *vsub;
struct osmo_mobile_identity mi;
struct msub *prev_msub;
struct msc_a *prev_msc_a;
int rc = osmo_mobile_identity_decode_from_l3(&mi, msg, false);
if (rc) {
LOGP(DMM, LOGL_ERROR, "CM RE-ESTABLISH REQUEST: cannot decode Mobile Identity\n");
return -EINVAL;
}
msc_a->complete_layer3_type = COMPLETE_LAYER3_CM_RE_ESTABLISH_REQ;
msub_update_id_from_mi(msc_a->c.msub, &mi);
DEBUGP(DMM, "<- CM RE-ESTABLISH REQUEST %s\n", osmo_mobile_identity_to_str_c(OTC_SELECT, &mi));
gh = (struct gsm48_hdr *) msgb_l3(msg);
req = (struct gsm48_service_request *) gh->data;
/* Unfortunately in Phase1 the Classmark2 length is variable, so we cannot
* just use gsm48_service_request struct, and need to parse it manually. */
cm2_len = gh->data[1];
cm2_buf = gh->data + 2;
cm2 = (struct gsm48_classmark2 *) cm2_buf;
/* Prevent buffer overrun: check the length of Classmark2 */
if (cm2_buf + cm2_len > msg->tail) {
LOG_MSC_A(msc_a, LOGL_ERROR, "Rx CM SERVICE REQUEST: Classmark2 "
"length=%u is too big\n", cm2_len);
return msc_gsm48_tx_mm_serv_rej(msc_a, GSM48_REJECT_INCORRECT_MESSAGE);
}
/* Look up the other, previously active connection for this subscriber */
vsub = vlr_subscr_find_by_mi(net->vlr, &mi, __func__);
prev_msub = msub_for_vsub(vsub);
prev_msc_a = msub_msc_a(prev_msub);
if (!vsub || !prev_msub || !prev_msc_a) {
LOG_MSC_A(msc_a, LOGL_ERROR, "CM Re-Establish Request for unknown subscriber: %s\n",
osmo_mobile_identity_to_str_c(OTC_SELECT, &mi));
if (vsub)
vlr_subscr_put(vsub, __func__);
return msc_gsm48_tx_mm_serv_rej(msc_a, GSM48_REJECT_CALL_CAN_NOT_BE_IDENTIFIED);
}
LOG_MSC_A(msc_a, LOGL_NOTICE, "New conn requesting Re-Establishment\n");
LOG_MSC_A(prev_msc_a, LOGL_NOTICE, "Old conn matching Re-Establishment request (%s)\n",
osmo_use_count_to_str_c(OTC_SELECT, &prev_msc_a->use_count));
if (!prev_msc_a->cc.call_leg || !prev_msc_a->cc.active_trans) {
LOG_MSC_A(msc_a, LOGL_ERROR, "CM Re-Establish Request only supported for voice calls\n");
if (vsub)
vlr_subscr_put(vsub, __func__);
return msc_gsm48_tx_mm_serv_rej(msc_a, GSM48_REJECT_CALL_CAN_NOT_BE_IDENTIFIED);
}
msc_a_get(prev_msc_a, __func__);
/* Move the call_leg and active CC trans over to the new msc_a */
call_leg_reparent(prev_msc_a->cc.call_leg,
msc_a->c.fi,
MSC_EV_CALL_LEG_TERM,
MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE,
MSC_EV_CALL_LEG_RTP_COMPLETE);
msc_a->cc.call_leg = prev_msc_a->cc.call_leg;
prev_msc_a->cc.call_leg = NULL;
msc_a->cc.active_trans = prev_msc_a->cc.active_trans;
msc_a->cc.active_trans->msc_a = msc_a;
msc_a_get(msc_a, MSC_A_USE_CC);
prev_msc_a->cc.active_trans = NULL;
msc_a_put(prev_msc_a, MSC_A_USE_CC);
/* Dis-associate the VLR subscriber from the previous msc_a, so that we can start a new Process Access Request
* on the new msc_a. */
if (vsub->proc_arq_fsm) {
osmo_fsm_inst_term(vsub->proc_arq_fsm, OSMO_FSM_TERM_REGULAR, NULL);
vsub->proc_arq_fsm = NULL;
}
if (prev_msub->vsub) {
vlr_subscr_put(prev_msub->vsub, VSUB_USE_MSUB);
prev_msub->vsub = NULL;
}
/* Clear the previous conn.
* FIXME: we are clearing the previous conn before having authenticated the new conn. That means anyone can send
* CM Re-Establishing requests with arbitrary mobile identities without having to authenticate, and can freely
* Clear any connections at will. */
msc_a_release_cn(prev_msc_a);
msc_a_put(prev_msc_a, __func__);
prev_msc_a = NULL;
/* Kick off Authentication and Ciphering for the new conn. */
is_utran = (msc_a->c.ran->type == OSMO_RAT_UTRAN_IU);
vlr_proc_acc_req(msc_a->c.fi,
MSC_A_EV_AUTHENTICATED, MSC_A_EV_CN_CLOSE, NULL,
net->vlr, msc_a,
VLR_PR_ARQ_T_CM_RE_ESTABLISH_REQ, 0,
&mi, &msc_a->via_cell.lai,
is_utran || net->authentication_required,
is_utran ? net->uea_encryption_mask > 0x01 : net->a5_encryption_mask > 0x01,
req->cipher_key_seq,
osmo_gsm48_classmark2_is_r99(cm2, cm2_len),
is_utran);
vlr_subscr_put(vsub, __func__);
/* From vlr_proc_acc_req() we expect an implicit dispatch of PR_ARQ_E_START, and we expect
* msc_vlr_subscr_assoc() to already have been called and completed. Has an error occurred? */
vsub = msc_a_vsub(msc_a);
if (!vsub) {
LOG_MSC_A(msc_a, LOGL_ERROR, "subscriber not allowed to do a CM Service Request\n");
return -EIO;
}
vsub->classmark.classmark2 = *cm2;
vsub->classmark.classmark2_len = cm2_len;
return 0;
}
static int gsm48_rx_mm_imsi_detach_ind(struct msc_a *msc_a, struct msgb *msg)
{
struct gsm_network *net = msc_a_net(msc_a);
struct gsm48_hdr *gh = msgb_l3(msg);
struct gsm48_imsi_detach_ind *idi =
(struct gsm48_imsi_detach_ind *) gh->data;
struct osmo_mobile_identity mi;
struct vlr_subscr *vsub = NULL;
int rc = osmo_mobile_identity_decode_from_l3(&mi, msg, false);
if (rc) {
LOGP(DMM, LOGL_ERROR, "IMSI DETACH INDICATION: cannot decode Mobile Identity\n");
return -EINVAL;
}
DEBUGP(DMM, "IMSI DETACH INDICATION: %s\n", osmo_mobile_identity_to_str_c(OTC_SELECT, &mi));
rate_ctr_inc(rate_ctr_group_get_ctr(net->msc_ctrs, MSC_CTR_LOC_UPDATE_TYPE_DETACH));
switch (mi.type) {
case GSM_MI_TYPE_TMSI:
vsub = vlr_subscr_find_by_tmsi(net->vlr, mi.tmsi, __func__);
break;
case GSM_MI_TYPE_IMSI:
vsub = vlr_subscr_find_by_imsi(net->vlr, mi.imsi, __func__);
break;
case GSM_MI_TYPE_IMEI:
case GSM_MI_TYPE_IMEISV:
/* no sim card... FIXME: what to do ? */
LOGP(DMM, LOGL_ERROR, "%s: unimplemented mobile identity type\n",
osmo_mobile_identity_to_str_c(OTC_SELECT, &mi));
break;
default:
LOGP(DMM, LOGL_ERROR, "%s: unknown mobile identity type\n",
osmo_mobile_identity_to_str_c(OTC_SELECT, &mi));
break;
}
if (!vsub) {
LOGP(DMM, LOGL_ERROR, "IMSI DETACH for unknown subscriber %s\n",
osmo_mobile_identity_to_str_c(OTC_SELECT, &mi));
} else {
LOGP(DMM, LOGL_INFO, "IMSI DETACH for %s\n", vlr_subscr_name(vsub));
msub_set_vsub(msc_a->c.msub, vsub);
if (vsub->cs.is_paging)
paging_expired(vsub);
vsub->classmark.classmark1 = idi->classmark1;
vlr_subscr_rx_imsi_detach(vsub);
osmo_signal_dispatch(SS_SUBSCR, S_SUBSCR_DETACHED, vsub);
vlr_subscr_put(vsub, __func__);
}
msc_a_release_cn(msc_a);
return 0;
}
static int gsm48_rx_mm_status(struct msgb *msg)
{
struct gsm48_hdr *gh = msgb_l3(msg);
DEBUGP(DMM, "MM STATUS (reject cause 0x%02x)\n", gh->data[0]);
return 0;
}
static int parse_gsm_auth_resp(uint8_t *res, uint8_t *res_len,
struct msc_a *msc_a,
struct msgb *msg)
{
struct gsm48_hdr *gh = msgb_l3(msg);
struct gsm48_auth_resp *ar = (struct gsm48_auth_resp*) gh->data;
if (msgb_l3len(msg) < sizeof(*gh) + sizeof(*ar)) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR, "MM AUTHENTICATION RESPONSE: l3 length invalid: %u\n",
msgb_l3len(msg));
return -EINVAL;
}
*res_len = sizeof(ar->sres);
memcpy(res, ar->sres, sizeof(ar->sres));
return 0;
}
static int parse_umts_auth_resp(uint8_t *res, uint8_t *res_len,
struct msc_a *msc_a,
struct msgb *msg)
{
struct gsm48_hdr *gh;
uint8_t *data;
uint8_t iei;
uint8_t ie_len;
unsigned int data_len;
/* First parse the GSM part */
if (parse_gsm_auth_resp(res, res_len, msc_a, msg))
return -EINVAL;
OSMO_ASSERT(*res_len == 4);
/* Then add the extended res part */
gh = msgb_l3(msg);
data = gh->data + sizeof(struct gsm48_auth_resp);
data_len = msgb_l3len(msg) - (data - (uint8_t*)msgb_l3(msg));
if (data_len < 3) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR, "MM AUTHENTICATION RESPONSE: "
"message length=%u is too short\n", data_len);
return -EINVAL;
}
iei = data[0];
ie_len = data[1];
if (iei != GSM48_IE_AUTH_RES_EXT) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR, "MM R99 AUTHENTICATION RESPONSE: expected IEI 0x%02x, got 0x%02x\n",
GSM48_IE_AUTH_RES_EXT, iei);
return -EINVAL;
}
if (ie_len > 12) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR,
"MM R99 AUTHENTICATION RESPONSE: extended Auth Resp IE 0x%02x is too large: %u bytes\n",
GSM48_IE_AUTH_RES_EXT, ie_len);
return -EINVAL;
}
*res_len += ie_len;
memcpy(res + 4, &data[2], ie_len);
return 0;
}
/* Chapter 9.2.3: Authentication Response */
static int gsm48_rx_mm_auth_resp(struct msc_a *msc_a, struct msgb *msg)
{
uint8_t res[16];
uint8_t res_len;
int rc;
bool is_umts;
struct vlr_subscr *vsub = msc_a_vsub(msc_a);
if (!vsub) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR, "MM AUTHENTICATION RESPONSE: invalid: no subscriber\n");
msc_a_release_mo(msc_a, GSM_CAUSE_AUTH_FAILED);
return -EINVAL;
}
is_umts = (msgb_l3len(msg) > sizeof(struct gsm48_hdr) + sizeof(struct gsm48_auth_resp));
if (is_umts)
rc = parse_umts_auth_resp(res, &res_len, msc_a, msg);
else
rc = parse_gsm_auth_resp(res, &res_len, msc_a, msg);
if (rc) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR,
"MM AUTHENTICATION RESPONSE: invalid: parsing %s AKA Auth Response"
" failed with rc=%d; dispatching zero length SRES/RES to trigger failure\n",
is_umts ? "UMTS" : "GSM", rc);
memset(res, 0, sizeof(res));
res_len = 0;
}
LOG_MSC_A_CAT(msc_a, DMM, LOGL_DEBUG, "MM %s AUTHENTICATION RESPONSE (%s = %s)\n",
is_umts ? "UMTS" : "GSM", is_umts ? "res" : "sres",
osmo_hexdump_nospc(res, res_len));
return vlr_subscr_rx_auth_resp(vsub, osmo_gsm48_classmark_is_r99(&vsub->classmark),
msc_a->c.ran->type == OSMO_RAT_UTRAN_IU,
res, res_len);
}
static int gsm48_rx_mm_auth_fail(struct msc_a *msc_a, struct msgb *msg)
{
struct gsm48_hdr *gh = msgb_l3(msg);
uint8_t cause;
uint8_t auts_tag;
uint8_t auts_len;
uint8_t *auts;
struct vlr_subscr *vsub = msc_a_vsub(msc_a);
if (!vsub) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR, "MM R99 AUTHENTICATION FAILURE: invalid: no subscriber\n");
msc_a_release_mo(msc_a, GSM_CAUSE_AUTH_FAILED);
return -EINVAL;
}
if (msgb_l3len(msg) < sizeof(*gh) + 1) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR, "MM R99 AUTHENTICATION FAILURE: l3 length invalid: %u\n",
msgb_l3len(msg));
msc_a_release_mo(msc_a, GSM_CAUSE_AUTH_FAILED);
return -EINVAL;
}
cause = gh->data[0];
if (cause != GSM48_REJECT_SYNCH_FAILURE) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_INFO, "MM R99 AUTHENTICATION FAILURE: cause 0x%0x\n", cause);
vlr_subscr_rx_auth_fail(vsub, NULL);
return 0;
}
/* This is a Synch Failure procedure, which should pass an AUTS to
* resynchronize the sequence nr with the HLR. Expecting exactly one
* TLV with 14 bytes of AUTS. */
if (msgb_l3len(msg) < sizeof(*gh) + 1 + 2) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_INFO,
"MM R99 AUTHENTICATION FAILURE: invalid Synch Failure: missing AUTS IE\n");
msc_a_release_mo(msc_a, GSM_CAUSE_AUTH_FAILED);
return -EINVAL;
}
auts_tag = gh->data[1];
auts_len = gh->data[2];
auts = &gh->data[3];
if (auts_tag != GSM48_IE_AUTS
|| auts_len != 14) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_INFO,
"MM R99 AUTHENTICATION FAILURE: invalid Synch Failure:"
" expected AUTS IE 0x%02x of 14 bytes,"
" got IE 0x%02x of %u bytes\n",
GSM48_IE_AUTS, auts_tag, auts_len);
msc_a_release_mo(msc_a, GSM_CAUSE_AUTH_FAILED);
return -EINVAL;
}
if (msgb_l3len(msg) < sizeof(*gh) + 1 + 2 + auts_len) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_INFO,
"MM R99 AUTHENTICATION FAILURE: invalid Synch Failure msg: message truncated (%u)\n",
msgb_l3len(msg));
msc_a_release_mo(msc_a, GSM_CAUSE_AUTH_FAILED);
return -EINVAL;
}
/* We have an AUTS IE with exactly 14 bytes of AUTS and the msgb is
* large enough. */
LOG_MSC_A_CAT(msc_a, DMM, LOGL_DEBUG, "MM R99 AUTHENTICATION SYNCH (AUTS = %s)\n",
osmo_hexdump_nospc(auts, 14));
return vlr_subscr_rx_auth_fail(vsub, auts);
}
static int gsm48_rx_mm_tmsi_reall_compl(struct msc_a *msc_a)
{
struct vlr_subscr *vsub = msc_a_vsub(msc_a);
if (!vsub) {
LOG_MSC_A_CAT(msc_a, DMM, LOGL_ERROR, "Rx MM TMSI Reallocation Complete: invalid: no subscriber\n");
return -EINVAL;
}
LOG_MSC_A_CAT(msc_a, DMM, LOGL_DEBUG, "TMSI Reallocation Completed\n");
return vlr_subscr_rx_tmsi_reall_compl(vsub);
}
/* Receive a GSM 04.08 Mobility Management (MM) message */
int gsm0408_rcv_mm(struct msc_a *msc_a, struct msgb *msg)
{
struct gsm48_hdr *gh = msgb_l3(msg);
int rc = 0;
switch (gsm48_hdr_msg_type(gh)) {
case GSM48_MT_MM_LOC_UPD_REQUEST:
rc = mm_rx_loc_upd_req(msc_a, msg);
break;
case GSM48_MT_MM_ID_RESP:
rc = mm_rx_id_resp(msc_a, msg);
break;
case GSM48_MT_MM_CM_SERV_REQ:
rc = gsm48_rx_mm_serv_req(msc_a, msg);
break;
case GSM48_MT_MM_STATUS:
rc = gsm48_rx_mm_status(msg);
break;
case GSM48_MT_MM_TMSI_REALL_COMPL:
rc = gsm48_rx_mm_tmsi_reall_compl(msc_a);
break;
case GSM48_MT_MM_IMSI_DETACH_IND:
rc = gsm48_rx_mm_imsi_detach_ind(msc_a, msg);
break;
case GSM48_MT_MM_CM_REEST_REQ:
rc = gsm48_rx_cm_reest_req(msc_a, msg);
break;
case GSM48_MT_MM_AUTH_RESP:
rc = gsm48_rx_mm_auth_resp(msc_a, msg);
break;
case GSM48_MT_MM_AUTH_FAIL:
rc = gsm48_rx_mm_auth_fail(msc_a, msg);
break;
default:
LOGP(DMM, LOGL_NOTICE, "Unknown GSM 04.08 MM msg type 0x%02x\n",
gh->msg_type);
break;
}
return rc;
}
/* Receive a PAGING RESPONSE message from the MS */
static int gsm48_rx_rr_pag_resp(struct msc_a *msc_a, struct msgb *msg)
{
struct gsm_network *net = msc_a_net(msc_a);
struct gsm48_hdr *gh = msgb_l3(msg);
struct gsm48_pag_resp *pr =
(struct gsm48_pag_resp *)gh->data;
uint8_t classmark2_len = gh->data[1];
uint8_t *classmark2_buf = gh->data+2;
struct gsm48_classmark2 *cm2 = (void*)classmark2_buf;
bool is_utran;
struct vlr_subscr *vsub;
struct osmo_mobile_identity mi;
int rc;
if (msc_a_is_establishing_auth_ciph(msc_a)) {
LOG_MSC_A_CAT(msc_a, DRR, LOGL_ERROR,
"Ignoring Paging Response, conn already busy establishing authenticity\n");
return 0;
}
if (msc_a_is_accepted(msc_a)) {
LOG_MSC_A_CAT(msc_a, DRR, LOGL_ERROR, "Ignoring Paging Response, conn already established\n");
return 0;
}
rc = osmo_mobile_identity_decode_from_l3(&mi, msg, false);
if (rc) {
LOG_MSC_A_CAT(msc_a, DRR, LOGL_ERROR, "Paging Response: cannot decode Mobile Identity\n");
return -EINVAL;
}
msc_a->complete_layer3_type = COMPLETE_LAYER3_PAGING_RESP;
msub_update_id_from_mi(msc_a->c.msub, &mi);
LOG_MSC_A_CAT(msc_a, DRR, LOGL_DEBUG, "Rx PAGING RESPONSE %s\n", osmo_mobile_identity_to_str_c(OTC_SELECT, &mi));
msc_a_get(msc_a, MSC_A_USE_PAGING_RESPONSE);
is_utran = (msc_a->c.ran->type == OSMO_RAT_UTRAN_IU);
vlr_proc_acc_req(msc_a->c.fi,
MSC_A_EV_AUTHENTICATED, MSC_A_EV_CN_CLOSE, NULL,
net->vlr, msc_a,
VLR_PR_ARQ_T_PAGING_RESP, 0, &mi, &msc_a->via_cell.lai,
is_utran || net->authentication_required,
is_utran ? net->uea_encryption_mask > 0x01 : net->a5_encryption_mask > 0x01,
pr->key_seq,
osmo_gsm48_classmark2_is_r99(cm2, classmark2_len),
is_utran);
/* From vlr_proc_acc_req() we expect an implicit dispatch of PR_ARQ_E_START we expect
* msc_vlr_subscr_assoc() to already have been called and completed. Has an error occurred? */
vsub = msc_a_vsub(msc_a);
if (!vsub) {
LOG_MSC_A_CAT(msc_a, DRR, LOGL_ERROR, "subscriber not allowed to do a Paging Response\n");
/* Above MSC_A_USE_PAGING_RESPONSE may already have been removed by a forced release, put that use only
* if it still exists. (see msc_a_fsm_releasing_onenter()) */
if (osmo_use_count_by(&msc_a->use_count, MSC_A_USE_PAGING_RESPONSE))
msc_a_put(msc_a, MSC_A_USE_PAGING_RESPONSE);
return -EIO;
}
vsub->classmark.classmark2 = *cm2;
vsub->classmark.classmark2_len = classmark2_len;
return 0;
}
static int gsm48_rx_rr_ciphering_mode_complete(struct msc_a *msc_a, struct msgb *msg)
{
struct vlr_subscr *vsub = msc_a_vsub(msc_a);
struct gsm48_hdr *gh = msgb_l3(msg);
unsigned int payload_len = msgb_l3len(msg) - sizeof(*gh);
struct tlv_parsed tp;
struct tlv_p_entry *mi_tlv;
struct osmo_mobile_identity mi;
tlv_parse(&tp, &gsm48_att_tlvdef, gh->data, payload_len, 0, 0);
mi_tlv = TLVP_GET(&tp, GSM48_IE_MOBILE_ID);
/* IMEI(SV) is optional for this message */
if (!mi_tlv)
return 0;
if (!mi_tlv->len)
return -EINVAL;
if (osmo_mobile_identity_decode(&mi, mi_tlv->val, mi_tlv->len, false)) {
LOGP(DMM, LOGL_ERROR, "RR Ciphering Mode Complete contains invalid Mobile Identity %s\n",
osmo_hexdump(mi_tlv->val, mi_tlv->len));
return -EINVAL;
}
if (mi.type != GSM_MI_TYPE_IMEISV) {
LOGP(DMM, LOGL_ERROR, "RR Ciphering Mode Complete contains "
"unexpected Mobile Identity type %s\n",
osmo_mobile_identity_to_str_c(OTC_SELECT, &mi));
return -EINVAL;
}
LOG_MSC_A(msc_a, LOGL_DEBUG, "RR Ciphering Mode Complete contains Mobile Identity: %s\n",
osmo_mobile_identity_to_str_c(OTC_SELECT, &mi));
if (!vsub)
return 0;
return vlr_subscr_rx_id_resp(vsub, &mi);
}
static int gsm48_rx_rr_app_info(struct msc_a *msc_a, struct msgb *msg)
{
struct gsm48_hdr *gh = msgb_l3(msg);
uint8_t apdu_id_flags;
uint8_t apdu_len;
uint8_t *apdu_data;
apdu_id_flags = gh->data[0];
apdu_len = gh->data[1];
apdu_data = gh->data+2;
LOG_MSC_A_CAT(msc_a, DRR, LOGL_DEBUG, "Rx RR APPLICATION INFO "
"(id/flags=0x%02x apdu_len=%u apdu=%s)\n",
apdu_id_flags, apdu_len, osmo_hexdump(apdu_data, apdu_len));
/* we're not using the app info blob anywhere, so ignore. */
#if 0
return db_apdu_blob_store(conn->subscr, apdu_id_flags, apdu_len, apdu_data);
#else
return 0;
#endif
}
/* Receive a GSM 04.08 Radio Resource (RR) message */
int gsm0408_rcv_rr(struct msc_a *msc_a, struct msgb *msg)
{
struct gsm48_hdr *gh = msgb_l3(msg);
int rc = 0;
switch (gh->msg_type) {
case GSM48_MT_RR_PAG_RESP:
rc = gsm48_rx_rr_pag_resp(msc_a, msg);
break;
case GSM48_MT_RR_CIPH_M_COMPL:
rc = gsm48_rx_rr_ciphering_mode_complete(msc_a, msg);
break;
case GSM48_MT_RR_APP_INFO:
rc = gsm48_rx_rr_app_info(msc_a, msg);
break;
default:
LOG_MSC_A_CAT(msc_a, DRR, LOGL_NOTICE, "MSC: Unimplemented %s GSM 04.08 RR "
"message\n", gsm48_rr_msg_name(gh->msg_type));
break;
}
return rc;
}
int gsm48_send_rr_app_info(struct msc_a *msc_a, uint8_t apdu_id,
uint8_t apdu_len, const uint8_t *apdu)
{
struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 APP INF");
struct gsm48_hdr *gh;
DEBUGP(DRR, "TX APPLICATION INFO id=0x%02x, len=%u\n",
apdu_id, apdu_len);
gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 2 + apdu_len);
gh->proto_discr = GSM48_PDISC_RR;
gh->msg_type = GSM48_MT_RR_APP_INFO;
gh->data[0] = apdu_id;
gh->data[1] = apdu_len;
memcpy(gh->data+2, apdu, apdu_len);
return msc_a_tx_dtap_to_i(msc_a, msg);
}
extern int gsm0408_rcv_cc(struct msc_a *msc_a, struct msgb *msg);
/***********************************************************************
* VLR integration
***********************************************************************/
/* VLR asks us to send an authentication request */
static int msc_vlr_tx_auth_req(void *msc_conn_ref, struct vlr_auth_tuple *at,
bool send_autn)
{
struct msc_a *msc_a = msc_conn_ref;
return gsm48_tx_mm_auth_req(msc_a, at->vec.rand,
send_autn? at->vec.autn : NULL,
at->key_seq);
}
/* VLR asks us to send an authentication reject */
static int msc_vlr_tx_auth_rej(void *msc_conn_ref)
{
struct msc_a *msc_a = msc_conn_ref;
return gsm48_tx_mm_auth_rej(msc_a);
}
/* VLR asks us to transmit an Identity Request of given type */
static int msc_vlr_tx_id_req(void *msc_conn_ref, uint8_t mi_type)
{
struct msc_a *msc_a = msc_conn_ref;
/* Store requested MI type, so we can check the response */
msc_a->mm_id_req_type = mi_type;
return mm_tx_identity_req(msc_a, mi_type);
}
/* VLR asks us to transmit a Location Update Accept */
static int msc_vlr_tx_lu_acc(void *msc_conn_ref, uint32_t send_tmsi)
{
struct msc_a *msc_a = msc_conn_ref;
return gsm0408_loc_upd_acc(msc_a, send_tmsi);
}
/* VLR asks us to transmit a Location Update Reject */
static int msc_vlr_tx_lu_rej(void *msc_conn_ref, enum gsm48_reject_value cause)
{
struct msc_a *msc_a = msc_conn_ref;
return gsm0408_loc_upd_rej(msc_a, cause);
}
/* VLR asks us to transmit a CM Service Accept */
int msc_vlr_tx_cm_serv_acc(void *msc_conn_ref, enum osmo_cm_service_type cm_service_type)
{
struct msc_a *msc_a = msc_conn_ref;
return msc_gsm48_tx_mm_serv_ack(msc_a);
}
static int msc_vlr_tx_common_id(void *msc_conn_ref)
{
struct msc_a *msc_a = msc_conn_ref;
struct vlr_subscr *vsub = msc_a_vsub(msc_a);
struct ran_msg msg = {
.msg_type = RAN_MSG_COMMON_ID,
.common_id = {
.imsi = vsub->imsi,
.last_eutran_plmn_present = vsub->sgs.last_eutran_plmn_present,
},
};
if (vsub->sgs.last_eutran_plmn_present) {
memcpy(&msg.common_id.last_eutran_plmn, &vsub->sgs.last_eutran_plmn,
sizeof(vsub->sgs.last_eutran_plmn));
}
return msc_a_ran_down(msc_a, MSC_ROLE_I, &msg);
}
/* VLR asks us to transmit MM info. */
static int msc_vlr_tx_mm_info(void *msc_conn_ref)
{
struct msc_a *msc_a = msc_conn_ref;
struct gsm_network *net = msc_a_net(msc_a);
if (!net->send_mm_info)
return 0;
return gsm48_tx_mm_info(msc_a);
}
/* VLR asks us to transmit a CM Service Reject */
static int msc_vlr_tx_cm_serv_rej(void *msc_conn_ref, enum osmo_cm_service_type cm_service_type,
enum gsm48_reject_value cause)
{
struct msc_a *msc_a = msc_conn_ref;
msc_gsm48_tx_mm_serv_rej(msc_a, cause);
msc_a_put(msc_a, msc_a_cm_service_type_to_use(cm_service_type));
return 0;
}
/* VLR informs us that the subscriber data has somehow been modified */
static void msc_vlr_subscr_update(struct vlr_subscr *subscr)
{
struct msub *msub = msub_for_vsub(subscr);
LOGVSUBP(LOGL_NOTICE, subscr, "VLR: update for IMSI=%s (MSISDN=%s)%s\n",
subscr->imsi, subscr->msisdn, msub ? "" : " (NO CONN!)");
msub_update_id(msub);
}
/* VLR informs us that the subscriber has been associated with a conn.
* The subscriber has *not* been authenticated yet, so the vsub should be protected from potentially invalid information
* from the msc_a. */
static int msc_vlr_subscr_assoc(void *msc_conn_ref,
struct vlr_subscr *vsub)
{
struct msc_a *msc_a = msc_conn_ref;
struct msub *msub = msc_a->c.msub;
OSMO_ASSERT(vsub);
if (msub_set_vsub(msub, vsub))
return -EINVAL;
/* FIXME: would be better to modify vsub->* only after the subscriber is authenticated, in
* evaluate_acceptance_outcome(conn_accepted == true). */
vsub->cs.attached_via_ran = msc_a->c.ran->type;
/* In case we have already received Classmark Information before the VLR Subscriber was
* associated with the conn: merge the new Classmark into vsub->classmark. Don't overwrite valid
* vsub->classmark with unset classmark, though. */
osmo_gsm48_classmark_update(&vsub->classmark, &msc_a->temporary_classmark);
msub_update_id(msub);
osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_A_EV_COMPLETE_LAYER_3_OK, NULL);
return 0;
}
/* operations that we need to implement for libvlr */
const struct vlr_ops msc_vlr_ops = {
.tx_auth_req = msc_vlr_tx_auth_req,
.tx_auth_rej = msc_vlr_tx_auth_rej,
.tx_id_req = msc_vlr_tx_id_req,
.tx_lu_acc = msc_vlr_tx_lu_acc,
.tx_lu_rej = msc_vlr_tx_lu_rej,
.tx_cm_serv_acc = msc_vlr_tx_cm_serv_acc,
.tx_cm_serv_rej = msc_vlr_tx_cm_serv_rej,
.set_ciph_mode = msc_a_vlr_set_cipher_mode,
.tx_common_id = msc_vlr_tx_common_id,
.tx_mm_info = msc_vlr_tx_mm_info,
.subscr_update = msc_vlr_subscr_update,
.subscr_assoc = msc_vlr_subscr_assoc,
};
struct msgb *gsm48_create_mm_serv_rej(enum gsm48_reject_value value)
{
struct msgb *msg;
struct gsm48_hdr *gh;
msg = gsm48_msgb_alloc_name("GSM 04.08 SERV REJ");
if (!msg)
return NULL;
gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1);
gh->proto_discr = GSM48_PDISC_MM;
gh->msg_type = GSM48_MT_MM_CM_SERV_REJ;
gh->data[0] = value;
return msg;
}
struct msgb *gsm48_create_loc_upd_rej(uint8_t cause)
{
struct gsm48_hdr *gh;
struct msgb *msg;
msg = gsm48_msgb_alloc_name("GSM 04.08 LOC UPD REJ");
if (!msg)
return NULL;
gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1);
gh->proto_discr = GSM48_PDISC_MM;
gh->msg_type = GSM48_MT_MM_LOC_UPD_REJECT;
gh->data[0] = cause;
return msg;
}
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