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[GPRS] SGSN: TMSI allocation

This commit is contained in:
Harald Welte 2010-05-18 17:04:55 +02:00
parent 4e38ac7a8a
commit 6463c0799c
4 changed files with 82 additions and 35 deletions
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2
openbsc/include/openbsc/gprs_sgsn.h
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@ -178,4 +178,6 @@ extern struct llist_head sgsn_ggsn_ctxts;
extern struct llist_head sgsn_apn_ctxts;
extern struct llist_head sgsn_pdp_ctxts;
uint32_t sgsn_alloc_ptmsi(void);
#endif /* _GPRS_SGSN_H */

9
openbsc/include/openbsc/gsm_04_08_gprs.h
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@ -63,11 +63,12 @@
#define GPRS_UPD_T_PERIODIC 3
enum gsm48_gprs_ie_mm {
GSM48_IE_GMM_TIMER_READY = 0x17, /* 10.5.7.3 */
GSM48_IE_GMM_TIMER_READY = 0x17, /* 10.5.7.3 */
GSM48_IE_GMM_ALLOC_PTMSI = 0x18, /* 10.5.1.4 */
GSM48_IE_GMM_PTMSI_SIG = 0x19, /* 10.5.5.8 */
GSM48_IE_GMM_AUTH_RAND = 0x21, /* 10.5.3.1 */
GSM48_IE_GMM_AUTH_SRES = 0x22, /* 10.5.3.2 */
GSM48_IE_GMM_IMEISV = 0x23, /* 10.5.1.4 */
GSM48_IE_GMM_AUTH_RAND = 0x21, /* 10.5.3.1 */
GSM48_IE_GMM_AUTH_SRES = 0x22, /* 10.5.3.2 */
GSM48_IE_GMM_IMEISV = 0x23, /* 10.5.1.4 */
GSM48_IE_GMM_DRX_PARAM = 0x27, /* 10.5.5.6 */
GSM48_IE_GMM_MS_NET_CAPA = 0x31, /* 10.5.5.12 */
};

91
openbsc/src/gprs/gprs_gmm.c
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@ -196,16 +196,16 @@ static struct gsm48_qos default_qos = {
};
/* Chapter 9.4.2: Attach accept */
static int gsm48_tx_gmm_att_ack(struct msgb *old_msg)
static int gsm48_tx_gmm_att_ack(struct sgsn_mm_ctx *mm)
{
struct msgb *msg = gsm48_msgb_alloc();
struct gsm48_hdr *gh;
struct gsm48_attach_ack *aa;
struct gprs_ra_id ra_id;
char *ptsig, *mid;
DEBUGP(DMM, "<- GPRS ATTACH ACCEPT\n");
gmm_copy_id(msg, old_msg);
mmctx2msgid(msg, mm);
gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
gh->proto_discr = GSM48_PDISC_MM_GPRS;
@ -216,23 +216,35 @@ static int gsm48_tx_gmm_att_ack(struct msgb *old_msg)
aa->att_result = 1; /* GPRS only */
aa->ra_upd_timer = GPRS_TMR_MINUTE | 10;
aa->radio_prio = 4; /* lowest */
bssgp_parse_cell_id(&ra_id, msgb_bcid(old_msg));
gsm48_construct_ra(aa->ra_id.digits, &ra_id);
gsm48_construct_ra(aa->ra_id.digits, &mm->ra);
/* Optional: P-TMSI signature */
msgb_v_put(msg, GSM48_IE_GMM_PTMSI_SIG);
ptsig = msgb_put(msg, 3);
ptsig[0] = mm->p_tmsi_sig >> 16;
ptsig[1] = mm->p_tmsi_sig >> 8;
ptsig[2] = mm->p_tmsi_sig & 0xff;
/* Optional: Negotiated Ready timer value */
/* Optional: Allocated P-TMSI */
msgb_v_put(msg, GSM48_IE_GMM_ALLOC_PTMSI);
mid = msgb_put(msg, GSM48_MID_TMSI_LEN);
gsm48_generate_mid_from_tmsi(mid, mm->p_tmsi);
/* Optional: MS-identity (combined attach) */
/* Optional: GMM cause (partial attach result for combined attach) */
/* Option: P-TMSI signature, allocated P-TMSI, MS ID, ... */
return gsm48_gmm_sendmsg(msg, 0, NULL);
}
/* Chapter 9.4.5: Attach reject */
static int gsm48_tx_gmm_att_rej(struct msgb *old_msg, uint8_t gmm_cause)
static int _tx_gmm_att_rej(struct msgb *msg, uint8_t gmm_cause)
{
struct msgb *msg = gsm48_msgb_alloc();
struct gsm48_hdr *gh;
DEBUGP(DMM, "<- GPRS ATTACH REJECT\n");
gmm_copy_id(msg, old_msg);
gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1);
gh->proto_discr = GSM48_PDISC_MM_GPRS;
gh->msg_type = GSM48_MT_GMM_ATTACH_REJ;
@ -240,15 +252,31 @@ static int gsm48_tx_gmm_att_rej(struct msgb *old_msg, uint8_t gmm_cause)
return gsm48_gmm_sendmsg(msg, 0, NULL);
}
static int gsm48_tx_gmm_att_rej_oldmsg(const struct msgb *old_msg,
uint8_t gmm_cause)
{
struct msgb *msg = gsm48_msgb_alloc();
gmm_copy_id(msg, old_msg);
return _tx_gmm_att_rej(msg, gmm_cause);
}
static int gsm48_tx_gmm_att_rej(struct sgsn_mm_ctx *mm,
uint8_t gmm_cause)
{
struct msgb *msg = gsm48_msgb_alloc();
mmctx2msgid(msg, mm);
return _tx_gmm_att_rej(msg, gmm_cause);
}
/* Chapter 9.4.6.2 Detach accept */
static gsm48_tx_gmm_det_ack(struct msgb *old_msg, uint8_t force_stby)
static gsm48_tx_gmm_det_ack(struct sgsn_mm_ctx *mm, uint8_t force_stby)
{
struct msgb *msg = gsm48_msgb_alloc();
struct gsm48_hdr *gh;
DEBUGP(DMM, "<- GPRS DETACH ACCEPT\n");
mmctx2msgid(msg, mm);
gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1);
gh->proto_discr = GSM48_PDISC_MM_GPRS;
gh->msg_type = GSM48_MT_GMM_DETACH_ACK;
@ -258,14 +286,14 @@ static gsm48_tx_gmm_det_ack(struct msgb *old_msg, uint8_t force_stby)
}
/* Transmit Chapter 9.4.12 Identity Request */
static int gsm48_tx_gmm_id_req(struct msgb *old_msg, uint8_t id_type)
static int gsm48_tx_gmm_id_req(struct sgsn_mm_ctx *mm, uint8_t id_type)
{
struct msgb *msg = gsm48_msgb_alloc();
struct gsm48_hdr *gh;
DEBUGP(DMM, "-> GPRS IDENTITY REQUEST: mi_type=%02x\n", id_type);
gmm_copy_id(msg, old_msg);
mmctx2msgid(msg, mm);
gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1);
gh->proto_discr = GSM48_PDISC_MM_GPRS;
@ -277,17 +305,17 @@ static int gsm48_tx_gmm_id_req(struct msgb *old_msg, uint8_t id_type)
}
/* Check if we can already authorize a subscriber */
static int gsm48_gmm_authorize(struct sgsn_mm_ctx *ctx, struct msgb *msg)
static int gsm48_gmm_authorize(struct sgsn_mm_ctx *ctx)
{
if (strlen(ctx->imei) && strlen(ctx->imsi)) {
ctx->mm_state = GMM_REGISTERED_NORMAL;
return gsm48_tx_gmm_att_ack(msg);
return gsm48_tx_gmm_att_ack(ctx);
}
if (!strlen(ctx->imei))
return gsm48_tx_gmm_id_req(msg, GSM_MI_TYPE_IMEI);
return gsm48_tx_gmm_id_req(ctx, GSM_MI_TYPE_IMEI);
if (!strlen(ctx->imsi))
return gsm48_tx_gmm_id_req(msg, GSM_MI_TYPE_IMSI);
return gsm48_tx_gmm_id_req(ctx, GSM_MI_TYPE_IMSI);
return 0;
}
@ -325,15 +353,14 @@ static int gsm48_rx_gmm_id_resp(struct sgsn_mm_ctx *ctx, struct msgb *msg)
DEBUGPC(DMM, "\n");
/* Check if we can let the mobile station enter */
return gsm48_gmm_authorize(ctx, msg);
return gsm48_gmm_authorize(ctx);
}
static void attach_rej_cb(void *data)
{
struct sgsn_mm_ctx *ctx = data;
/* FIXME: determine through which BTS/TRX to send this */
//gsm48_tx_gmm_att_rej(ctx->tlli, GMM_CAUSE_MS_ID_NOT_DERIVED);
gsm48_tx_gmm_att_rej(ctx, GMM_CAUSE_MS_ID_NOT_DERIVED);
ctx->mm_state = GMM_DEREGISTERED;
/* FIXME: release the context */
}
@ -413,7 +440,7 @@ static int gsm48_rx_gmm_att_req(struct sgsn_mm_ctx *mmctx, struct msgb *msg)
/* As a temorary hack, we simply assume that the IMSI exists */
ctx = sgsn_mm_ctx_alloc(0, &ra_id);
if (!ctx)
return gsm48_tx_gmm_att_rej(msg, GMM_CAUSE_NET_FAIL);
return gsm48_tx_gmm_att_rej_oldmsg(msg, GMM_CAUSE_NET_FAIL);
strncpy(ctx->imsi, mi_string, sizeof(ctx->imsi));
#endif
}
@ -433,6 +460,7 @@ static int gsm48_rx_gmm_att_req(struct sgsn_mm_ctx *mmctx, struct msgb *msg)
ctx->tlli = msgb_tlli(msg);
msgid2mmctx(ctx, msg);
}
ctx->p_tmsi = tmsi;
break;
default:
return 0;
@ -441,16 +469,18 @@ static int gsm48_rx_gmm_att_req(struct sgsn_mm_ctx *mmctx, struct msgb *msg)
ctx->ra = ra_id;
ctx->cell_id = cid;
/* FIXME: allocate a new P-TMSI (+ P-TMSI signature) */
/* Allocate a new P-TMSI (+ P-TMSI signature) */
ctx->p_tmsi = sgsn_alloc_ptmsi();
/* FIXME: update the TLLI with the new local TLLI based on the P-TMSI */
DEBUGPC(DMM, "\n");
return ctx ? gsm48_gmm_authorize(ctx, msg) : 0;
return ctx ? gsm48_gmm_authorize(ctx) : 0;
err_inval:
DEBUGPC(DMM, "\n");
return gsm48_tx_gmm_att_rej(msg, GMM_CAUSE_SEM_INCORR_MSG);
return gsm48_tx_gmm_att_rej_oldmsg(msg, GMM_CAUSE_SEM_INCORR_MSG);
}
/* Section 4.7.4.1 / 9.4.5.2 MO Detach request */
@ -472,20 +502,19 @@ static int gsm48_rx_gmm_det_req(struct sgsn_mm_ctx *ctx, struct msgb *msg)
ctx->mm_state = GMM_DEREGISTERED;
/* force_stby = 0 */
return gsm48_tx_gmm_det_ack(msg, 0);
return gsm48_tx_gmm_det_ack(ctx, 0);
}
/* Chapter 9.4.15: Routing area update accept */
static int gsm48_tx_gmm_ra_upd_ack(struct msgb *old_msg)
static int gsm48_tx_gmm_ra_upd_ack(struct sgsn_mm_ctx *mm)
{
struct msgb *msg = gsm48_msgb_alloc();
struct gsm48_hdr *gh;
struct gsm48_ra_upd_ack *rua;
struct gprs_ra_id ra_id;
DEBUGP(DMM, "<- ROUTING AREA UPDATE ACCEPT\n");
gmm_copy_id(msg, old_msg);
mmctx2msgid(msg, mm);
gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
gh->proto_discr = GSM48_PDISC_MM_GPRS;
@ -496,8 +525,7 @@ static int gsm48_tx_gmm_ra_upd_ack(struct msgb *old_msg)
rua->upd_result = 0; /* RA updated */
rua->ra_upd_timer = GPRS_TMR_MINUTE | 10;
bssgp_parse_cell_id(&ra_id, msgb_bcid(old_msg));
gsm48_construct_ra(rua->ra_id.digits, &ra_id);
gsm48_construct_ra(rua->ra_id.digits, &mm->ra);
/* Option: P-TMSI signature, allocated P-TMSI, MS ID, ... */
return gsm48_gmm_sendmsg(msg, 0, NULL);
@ -574,7 +602,7 @@ static int gsm48_rx_gmm_ra_upd_req(struct sgsn_mm_ctx *mmctx, struct msgb *msg)
rate_ctr_inc(&mmctx->ctrg->ctr[GMM_CTR_RA_UPDATE]);
DEBUGPC(DMM, " ACCEPT\n");
return gsm48_tx_gmm_ra_upd_ack(msg);
return gsm48_tx_gmm_ra_upd_ack(mmctx);
}
static int gsm48_rx_gmm_status(struct sgsn_mm_ctx *mmctx, struct msgb *msg)
@ -838,6 +866,7 @@ static int gsm48_rx_gsm_act_pdp_req(struct sgsn_mm_ctx *mmctx,
pdp->ti = transaction_id;
}
return 0;
#else
return gsm48_tx_gsm_act_pdp_acc(mmctx, transaction_id, act_req);
#endif

15
openbsc/src/gprs/gprs_sgsn.c
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@ -251,3 +251,18 @@ struct apn_ctx *apn_ctx_find_alloc(const char *name)
return actx;
}
#endif
uint32_t sgsn_alloc_ptmsi(void)
{
struct sgsn_mm_ctx *mm;
uint32_t ptmsi;
restart:
ptmsi = rand();
llist_for_each_entry(mm, &sgsn_mm_ctxts, list) {
if (mm->p_tmsi == ptmsi)
goto restart;
}
return ptmsi;
}