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ASCI: Add support for rest octets in Paging request type 2 and 3 

Currently the rest octets contain Notification List Number (NLN) and
NLN status and the "Channel Needed" (CN3 / CN4) fields for mobile
identities.

The existing encoding of CN3 / CN4 in Paging request type 3 has been
replaced.

The missing encoding of CN3 in Paging request type 2 has been added.

Change-Id: I6e33a6d38d4c7b124de35b53d219b64bb881ba66
Related: OS#5781
This commit is contained in:
Andreas Eversberg 2023-05-31 12:40:56 +02:00
parent 6fa1dfce61
commit 290085787a
1 changed files with 127 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

139
src/common/paging.c
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@ -353,6 +353,33 @@ struct p1_rest_octets {
} r8;
};
/* abstract representation of P2 rest octets; we only implement those parts we need for now */
struct p2_rest_octets {
struct {
bool present;
uint8_t cn3;
} cneed;
struct {
bool present;
uint8_t nln;
uint8_t nln_status;
} nln_pch;
};
/* abstract representation of P3 rest octets; we only implement those parts we need for now */
struct p3_rest_octets {
struct {
bool present;
uint8_t cn3;
uint8_t cn4;
} cneed;
struct {
bool present;
uint8_t nln;
uint8_t nln_status;
} nln_pch;
};
/* 3GPP TS 44.018 10.5.2.23 append a segment/page of an ETWS primary notification to given bitvec */
static void append_etws_prim_notif(struct bitvec *bv, bool is_first, uint8_t page_nr,
const uint8_t *etws, ssize_t etws_len)
@ -424,6 +451,49 @@ static void append_p1_rest_octets(struct bitvec *bv, const struct p1_rest_octets
}
}
/* 3GPP TS 44.018 10.5.2.24 append P2 Rest Octets to given bit-vector */
static void append_p2_rest_octets(struct bitvec *bv, const struct p2_rest_octets *p2ro)
{
/* {L | H <CN3: bit (2)>} */
if (p2ro->cneed.present) {
bitvec_set_bit(bv, H);
bitvec_set_uint(bv, p2ro->cneed.cn3, 2);
} else
bitvec_set_bit(bv, L); /* no CN3 */
/* {L | H < NLN(PCH) : bit (2) <NLN status(PCH) : bit>} */
if (p2ro->nln_pch.present) {
bitvec_set_bit(bv, H);
bitvec_set_uint(bv, p2ro->nln_pch.nln, 2);
bitvec_set_uint(bv, p2ro->nln_pch.nln_status, 1);
} else
bitvec_set_bit(bv, L); /* no NLN */
/* Note: If this needs to be extended in the future, check if it actually fits into rest of P2! */
}
/* 3GPP TS 44.018 10.5.2.25 append P3 Rest Octets to given bit-vector */
static void append_p3_rest_octets(struct bitvec *bv, const struct p3_rest_octets *p3ro)
{
/* {L | H <CN3: bit (2)> <CN3: bit (2)>} */
if (p3ro->cneed.present) {
bitvec_set_bit(bv, H);
bitvec_set_uint(bv, p3ro->cneed.cn3, 2);
bitvec_set_uint(bv, p3ro->cneed.cn4, 2);
} else
bitvec_set_bit(bv, L); /* no CN3/CN4 */
/* {L | H < NLN(PCH) : bit (2) <NLN status(PCH) : bit>} */
if (p3ro->nln_pch.present) {
bitvec_set_bit(bv, H);
bitvec_set_uint(bv, p3ro->nln_pch.nln, 2);
bitvec_set_uint(bv, p3ro->nln_pch.nln_status, 1);
} else
bitvec_set_bit(bv, L); /* no NLN */
/* Note: If this needs to be extended in the future, check if it actually fits into 3 octets! */
}
static int fill_paging_type_1(uint8_t *out_buf, const uint8_t *identity1_lv,
uint8_t chan1, const uint8_t *identity2_lv,
uint8_t chan2, const struct p1_rest_octets *p1ro,
@ -466,10 +536,12 @@ static int fill_paging_type_1(uint8_t *out_buf, const uint8_t *identity1_lv,
static int fill_paging_type_2(uint8_t *out_buf, const uint8_t *tmsi1_lv,
uint8_t cneed1, const uint8_t *tmsi2_lv,
uint8_t cneed2, const uint8_t *identity3_lv)
uint8_t cneed2, const uint8_t *identity3_lv,
const struct p2_rest_octets *p2ro)
{
struct gsm48_paging2 *pt2 = (struct gsm48_paging2 *) out_buf;
uint32_t tmsi;
unsigned int ro_len;
uint8_t *cur;
int rc;
@ -493,16 +565,32 @@ static int fill_paging_type_2(uint8_t *out_buf, const uint8_t *tmsi1_lv,
pt2->l2_plen = L2_PLEN(cur - out_buf);
return cur - out_buf;
/* Pad remaining octets with constant '2B'O */
ro_len = GSM_MACBLOCK_LEN - (cur - out_buf);
memset(cur, GSM_MACBLOCK_PADDING, ro_len);
/* Optional P2 Rest Octets */
if (p2ro) {
struct bitvec bv = {
.data_len = ro_len,
.data = cur,
};
append_p2_rest_octets(&bv, p2ro);
}
return GSM_MACBLOCK_LEN;
}
static int fill_paging_type_3(uint8_t *out_buf, const uint8_t *tmsi1_lv, uint8_t cneed1,
const uint8_t *tmsi2_lv, uint8_t cneed2,
const uint8_t *tmsi3_lv, uint8_t cneed3,
const uint8_t *tmsi4_lv, uint8_t cneed4)
const uint8_t *tmsi3_lv, const uint8_t *tmsi4_lv,
const struct p3_rest_octets *p3ro)
{
struct gsm48_paging3 *pt3 = (struct gsm48_paging3 *) out_buf;
uint32_t tmsi;
unsigned int ro_len;
uint8_t *cur;
int rc;
memset(out_buf, 0, sizeof(*pt3));
@ -524,13 +612,25 @@ static int fill_paging_type_3(uint8_t *out_buf, const uint8_t *tmsi1_lv, uint8_t
rc = tmsi_mi_to_uint(&tmsi, tmsi4_lv);
if (rc == 0)
pt3->tmsi4 = tmsi;
cur = out_buf + 20; /* Cannot use sizeof(*pt3), because it has more octets. */
/* The structure definition in libosmocore is wrong. It includes as last
* byte some invalid definition of chneed3/chneed4, so we must do this by hand
* here and cannot rely on sizeof(*pt3) */
out_buf[20] = (0x23 & ~0xf8) | 0x80 | (cneed3 & 3) << 5 | (cneed4 & 3) << 3;
pt3->l2_plen = L2_PLEN(cur - out_buf);
return 21;
/* Pad remaining octets with constant '2B'O */
ro_len = GSM_MACBLOCK_LEN - (cur - out_buf);
memset(cur, GSM_MACBLOCK_PADDING, ro_len);
/* Optional P3 Rest Octets */
if (p3ro) {
struct bitvec bv = {
.data_len = ro_len,
.data = cur,
};
append_p3_rest_octets(&bv, p3ro);
}
return GSM_MACBLOCK_LEN;
}
static const uint8_t empty_id_lv[] = { 0x01, 0xF0 };
@ -690,24 +790,39 @@ int paging_gen_msg(struct paging_state *ps, uint8_t *out_buf, struct gsm_time *g
if (num_pr == 4 && num_imsi == 0) {
/* No IMSI: easy case, can use TYPE 3 */
DEBUGP(DPAG, "Tx PAGING TYPE 3 (4 TMSI)\n");
struct p3_rest_octets p3ro;
memset(&p3ro, 0, sizeof(p3ro));
p3ro.cneed.present = true;
p3ro.cneed.cn3 = pr[2]->u.normal.chan_needed;
p3ro.cneed.cn4 = pr[3]->u.normal.chan_needed;
p3ro.nln_pch.present = (bts->asci.pos_nch >= 0);
p3ro.nln_pch.nln = bts->asci.nln;
p3ro.nln_pch.nln_status = bts->asci.nln_status;
len = fill_paging_type_3(out_buf,
pr[0]->u.normal.identity_lv,
pr[0]->u.normal.chan_needed,
pr[1]->u.normal.identity_lv,
pr[1]->u.normal.chan_needed,
pr[2]->u.normal.identity_lv,
pr[2]->u.normal.chan_needed,
pr[3]->u.normal.identity_lv,
pr[3]->u.normal.chan_needed);
&p3ro);
} else if (num_pr >= 3 && num_imsi <= 1) {
/* 3 or 4, of which only up to 1 is IMSI */
DEBUGP(DPAG, "Tx PAGING TYPE 2 (2 TMSI,1 xMSI)\n");
struct p2_rest_octets p2ro;
memset(&p2ro, 0, sizeof(p2ro));
p2ro.cneed.present = true;
p2ro.cneed.cn3 = pr[2]->u.normal.chan_needed;
p2ro.nln_pch.present = (bts->asci.pos_nch >= 0);
p2ro.nln_pch.nln = bts->asci.nln;
p2ro.nln_pch.nln_status = bts->asci.nln_status;
len = fill_paging_type_2(out_buf,
pr[0]->u.normal.identity_lv,
pr[0]->u.normal.chan_needed,
pr[1]->u.normal.identity_lv,
pr[1]->u.normal.chan_needed,
pr[2]->u.normal.identity_lv);
pr[2]->u.normal.identity_lv,
&p2ro);
if (num_pr == 4) {
/* re-add #4 for next time */
llist_add(&pr[3]->list, group_q);