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osmo-bts/src/common/paging.c

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/* Paging message encoding + queue management */
/* (C) 2011-2012 by Harald Welte <laforge@gnumonks.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/>.
*
*/
/* TODO:
* eMLPP priprity
* add P2/P3 rest octets
*/
#include <stdlib.h>
#include <stdint.h>
#include <errno.h>
#include <string.h>
#include <time.h>
#include <osmocom/core/talloc.h>
#include <osmocom/core/linuxlist.h>
#include <osmocom/gsm/protocol/gsm_04_08.h>
#include <osmocom/gsm/gsm0502.h>
#include <osmocom/gsm/gsm48.h>
#include <osmo-bts/bts.h>
#include <osmo-bts/rsl.h>
#include <osmo-bts/logging.h>
#include <osmo-bts/paging.h>
#include <osmo-bts/signal.h>
#include <osmo-bts/pcu_if.h>
#include <osmo-bts/notification.h>
#define MAX_PAGING_BLOCKS_CCCH 9
#define MAX_BS_PA_MFRMS 9
enum paging_record_type {
PAGING_RECORD_NORMAL,
PAGING_RECORD_MACBLOCK
};
struct paging_record {
struct llist_head list;
enum paging_record_type type;
union {
struct {
time_t expiration_time;
uint8_t chan_needed;
uint8_t identity_lv[9];
} normal;
struct {
uint8_t msg[GSM_MACBLOCK_LEN];
bool confirm;
uint32_t msg_id; /* used as identifier for confirmation */
} macblock;
} u;
};
struct paging_state {
struct gsm_bts *bts;
/* parameters taken / interpreted from BCCH/CCCH configuration */
struct gsm48_control_channel_descr chan_desc;
/* configured otherwise */
unsigned int paging_lifetime; /* in seconds */
unsigned int num_paging_max;
/* total number of currently active paging records in queue */
unsigned int num_paging;
struct llist_head paging_queue[MAX_PAGING_BLOCKS_CCCH*MAX_BS_PA_MFRMS];
/* prioritization of cs pagings will automatically become
* active on congestions (queue almost full) */
bool cs_priority_active;
};
/* The prioritization of cs pagings is controlled by a hysteresis. When the
* fill state of the paging queue exceeds the upper fill level
* THRESHOLD_CONGESTED [%], then PS pagings (immediate assignments and pagings
* from the PCU) will be dropped until fill state of the paging queue drops
* under the lower fill level THRESHOLD_CLEAR [%]. */
#define THRESHOLD_CONGESTED 66 /* (percent of num_paging_max) */
#define THRESHOLD_CLEAR 50 /* (percent of num_paging_max) */
/* Check the queue fill status and decide if prioritization of CS pagings
* must be turned on to flatten the negative effects of the congestion
* situation on the CS domain. */
static void check_congestion(struct paging_state *ps)
{
int pag_queue_len = paging_queue_length(ps);
int pag_queue_max = paging_get_queue_max(ps);
unsigned int treshold_upper = pag_queue_max * THRESHOLD_CONGESTED / 100;
unsigned int treshold_lower = pag_queue_max * THRESHOLD_CLEAR / 100;
if (pag_queue_len > treshold_upper && ps->cs_priority_active == false) {
ps->cs_priority_active = true;
rate_ctr_inc2(ps->bts->ctrs, BTS_CTR_PAGING_CONG);
} else if (pag_queue_len < treshold_lower)
ps->cs_priority_active = false;
}
unsigned int paging_get_lifetime(struct paging_state *ps)
{
return ps->paging_lifetime;
}
unsigned int paging_get_queue_max(struct paging_state *ps)
{
return ps->num_paging_max;
}
void paging_set_lifetime(struct paging_state *ps, unsigned int lifetime)
{
ps->paging_lifetime = lifetime;
}
void paging_set_queue_max(struct paging_state *ps, unsigned int queue_max)
{
ps->num_paging_max = queue_max;
}
static int tmsi_mi_to_uint(uint32_t *out, const uint8_t *tmsi_lv)
{
if (tmsi_lv[0] < 5)
return -EINVAL;
if ((tmsi_lv[1] & 7) != GSM_MI_TYPE_TMSI)
return -EINVAL;
*out = *((uint32_t *)(tmsi_lv+2));
return 0;
}
/* paging block numbers in a simple non-combined CCCH */
static const uint8_t block_by_tdma51[51] = {
255, 255, /* FCCH, SCH */
255, 255, 255, 255, /* BCCH */
0, 0, 0, 0, /* B0(6..9) */
255, 255, /* FCCH, SCH */
1, 1, 1, 1, /* B1(12..15) */
2, 2, 2, 2, /* B2(16..19) */
255, 255, /* FCCH, SCH */
3, 3, 3, 3, /* B3(22..25) */
4, 4, 4, 4, /* B3(26..29) */
255, 255, /* FCCH, SCH */
5, 5, 5, 5, /* B3(32..35) */
6, 6, 6, 6, /* B3(36..39) */
255, 255, /* FCCH, SCH */
7, 7, 7, 7, /* B3(42..45) */
8, 8, 8, 8, /* B3(46..49) */
255, /* empty */
};
/* get the paging block number _within_ current 51 multiframe */
static int get_pag_idx_n(struct paging_state *ps, struct gsm_time *gt)
{
int blk_n = block_by_tdma51[gt->t3];
int blk_idx;
if (blk_n == 255)
return -EINVAL;
blk_idx = blk_n - ps->chan_desc.bs_ag_blks_res;
if (blk_idx < 0)
return -EINVAL;
return blk_idx;
}
/* get paging block index over multiple 51 multiframes */
static int get_pag_subch_nr(struct paging_state *ps, struct gsm_time *gt)
{
int pag_idx = get_pag_idx_n(ps, gt);
unsigned int n_pag_blks_51 = gsm0502_get_n_pag_blocks(&ps->chan_desc);
unsigned int mfrm_part;
if (pag_idx < 0)
return pag_idx;
mfrm_part = ((gt->fn / 51) % (ps->chan_desc.bs_pa_mfrms+2)) * n_pag_blks_51;
return pag_idx + mfrm_part;
}
int paging_buffer_space(struct paging_state *ps)
{
if (ps->num_paging >= ps->num_paging_max)
return 0;
else
return ps->num_paging_max - ps->num_paging;
}
/* Add an identity to the paging queue */
int paging_add_identity(struct paging_state *ps, uint8_t paging_group,
const uint8_t *identity_lv, uint8_t chan_needed)
{
struct llist_head *group_q = &ps->paging_queue[paging_group];
int blocks = gsm48_number_of_paging_subchannels(&ps->chan_desc);
struct paging_record *pr;
check_congestion(ps);
rate_ctr_inc2(ps->bts->ctrs, BTS_CTR_PAGING_RCVD);
if (paging_group >= blocks) {
LOGP(DPAG, LOGL_ERROR, "BSC Send PAGING for group %u, but number of paging "
"sub-channels is only %u\n", paging_group, blocks);
rate_ctr_inc2(ps->bts->ctrs, BTS_CTR_PAGING_DROP);
return -EINVAL;
}
if (ps->num_paging >= ps->num_paging_max) {
LOGP(DPAG, LOGL_NOTICE, "Dropping paging, queue full (%u)\n",
ps->num_paging);
rate_ctr_inc2(ps->bts->ctrs, BTS_CTR_PAGING_DROP);
return -ENOSPC;
}
/* Check if we already have this identity */
llist_for_each_entry(pr, group_q, list) {
if (pr->type != PAGING_RECORD_NORMAL)
continue;
if (identity_lv[0] == pr->u.normal.identity_lv[0] &&
!memcmp(identity_lv+1, pr->u.normal.identity_lv+1,
identity_lv[0])) {
LOGP(DPAG, LOGL_INFO, "Ignoring duplicate paging\n");
pr->u.normal.expiration_time =
time(NULL) + ps->paging_lifetime;
return -EEXIST;
}
}
pr = talloc_zero(ps, struct paging_record);
if (!pr)
return -ENOMEM;
pr->type = PAGING_RECORD_NORMAL;
if (*identity_lv + 1 > sizeof(pr->u.normal.identity_lv)) {
talloc_free(pr);
return -E2BIG;
}
LOGP(DPAG, LOGL_INFO, "Add paging to queue (group=%u, queue_len=%u)\n",
paging_group, ps->num_paging+1);
pr->u.normal.expiration_time = time(NULL) + ps->paging_lifetime;
pr->u.normal.chan_needed = chan_needed;
memcpy(&pr->u.normal.identity_lv, identity_lv, identity_lv[0]+1);
/* enqueue the new identity to the HEAD of the queue,
* to ensure it will be paged quickly at least once. */
llist_add(&pr->list, group_q);
ps->num_paging++;
return 0;
}
/* Convert the last three digits of a given IMSI string to their decimal representation. In case the given IMSI string
* is shorter than three or zero digits, it will be assumed as "000" */
static uint16_t convert_imsi_to_decimal(const char *imsi)
{
uint16_t _imsi;
size_t imsi_len = strlen(imsi);
/* Tha paging group is calculated from the last three digits of the IMSI */
if (imsi_len < 3) {
LOGP(DPAG, LOGL_ERROR, "short IMSI (%zu digits), will assume \"000\" to calculate paging group\n", imsi_len);
_imsi = 0;
} else {
imsi = imsi + imsi_len - 3;
_imsi = 100 * ((*(imsi++)) - '0');
_imsi += 10 * ((*(imsi++)) - '0');
_imsi += (*(imsi++)) - '0';
}
return _imsi;
}
/* Add a ready formatted MAC block message to the paging queue, this can be an IMMEDIATE ASSIGNMENT, or a
* PAGING COMMAND (from the PCU) */
int paging_add_macblock(struct paging_state *ps, uint32_t msg_id, const char *imsi, bool confirm, const uint8_t *macblock)
{
struct llist_head *group_q;
struct paging_record *pr;
uint16_t paging_group;
uint16_t _imsi;
check_congestion(ps);
if (ps->cs_priority_active) {
LOGP(DPAG, LOGL_NOTICE, "Dropping paging for PS, queue congested (%u)\n",
ps->num_paging);
rate_ctr_inc2(ps->bts->ctrs, BTS_CTR_PAGING_DROP_PS);
return -ENOSPC;
}
_imsi = convert_imsi_to_decimal(imsi);
paging_group = gsm0502_calc_paging_group(&ps->chan_desc, _imsi);
group_q = &ps->paging_queue[paging_group];
pr = talloc_zero(ps, struct paging_record);
if (!pr)
return -ENOMEM;
pr->type = PAGING_RECORD_MACBLOCK;
LOGP(DPAG, LOGL_INFO, "Add MAC block to paging queue (group=%u)\n",
paging_group);
memcpy(pr->u.macblock.msg, macblock, GSM_MACBLOCK_LEN);
pr->u.macblock.confirm = confirm;
pr->u.macblock.msg_id = msg_id;
/* enqueue the new message to the HEAD of the queue */
llist_add(&pr->list, group_q);
return 0;
}
#define L2_PLEN(len) (((len - 1) << 2) | 0x01)
/* 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)
{
OSMO_ASSERT(etws_len < 128/8);
/* ETWS primary Notification struct
* 0 NNNN / 1 NNNN
* PNI n
* LEN nnnnnnn (at least 13 bits before paylod)
* number of bits (LEN; up to 128) */
if (is_first)
bitvec_set_bit(bv, 0);
else
bitvec_set_bit(bv, 1);
bitvec_set_uint(bv, page_nr, 4); /* Segment Number / Total Number */
bitvec_set_bit(bv, 0); /* PNI to distinguish different ETWS */
bitvec_set_uint(bv, etws_len*8, 7); /* length of payload in number of bits */
bitvec_set_bytes(bv, etws, etws_len);
/* 17 bytes = 136bit - (11+13) = 112 bits = 14 bytes per PT1
* => at least 4x PT1 RO for complete primary notification (56 bytes) */
}
/* 3GPP TS 44.018 10.5.2.23 append P1 Rest Octets to given bit-vector */
void append_p1_rest_octets(struct bitvec *bv, const struct p1_rest_octets *p1ro,
const struct asci_notification *notif)
{
/* Paging 1 RO (at least 10 bits before ETWS struct) */
if (p1ro->nln_pch.present) {
bitvec_set_bit(bv, H);
bitvec_set_uint(bv, p1ro->nln_pch.nln, 2);
bitvec_set_uint(bv, p1ro->nln_pch.nln_status, 1);
} else {
bitvec_set_bit(bv, L); /* no NLN */
}
bitvec_set_bit(bv, L); /* no Priority1 */
bitvec_set_bit(bv, L); /* no Priority2 */
if (notif) {
bitvec_set_bit(bv, H); /* Group Call Info */
append_group_call_information(bv, notif->group_call_ref,
notif->chan_desc.present ? notif->chan_desc.value : NULL,
notif->chan_desc.len);
} else {
bitvec_set_bit(bv, L); /* no Group Call Info */
}
if (p1ro->packet_page_ind[0])
bitvec_set_bit(bv, H); /* Packet Page Indication 1 */
else
bitvec_set_bit(bv, L); /* Packet Page Indication 1 */
if (p1ro->packet_page_ind[1])
bitvec_set_bit(bv, H); /* Packet Page Indication 2 */
else
bitvec_set_bit(bv, L); /* Packet Page Indication 2 */
bitvec_set_bit(bv, L); /* No Release 6 additions */
bitvec_set_bit(bv, L); /* No Release 7 additions */
if (p1ro->r8_present) {
bitvec_set_bit(bv, H); /* Release 8 */
bitvec_set_bit(bv, p1ro->r8.prio_ul_access); /* Priority Uplink Access */
if (p1ro->r8.etws_present) {
bitvec_set_bit(bv, 1); /* ETWS present */
append_etws_prim_notif(bv, p1ro->r8.etws.is_first, p1ro->r8.etws.page_nr,
p1ro->r8.etws.page, p1ro->r8.etws.page_bytes);
} else
bitvec_set_bit(bv, 0);
}
}
/* 3GPP TS 44.018 10.5.2.24 append P2 Rest Octets to given bit-vector */
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 */
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,
const struct asci_notification *notif)
{
struct gsm48_paging1 *pt1 = (struct gsm48_paging1 *) out_buf;
unsigned int ro_len;
uint8_t *cur;
*pt1 = (struct gsm48_paging1) {
.proto_discr = GSM48_PDISC_RR,
.msg_type = GSM48_MT_RR_PAG_REQ_1,
.pag_mode = GSM48_PM_NORMAL,
.cneed1 = chan1 & 3,
.cneed2 = chan2 & 3,
};
cur = lv_put(pt1->data, identity1_lv[0], identity1_lv+1);
if (identity2_lv)
cur = tlv_put(cur, GSM48_IE_MOBILE_ID, identity2_lv[0], identity2_lv+1);
pt1->l2_plen = L2_PLEN(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 P1 Rest Octets */
if (p1ro) {
struct bitvec bv = {
.data_len = ro_len,
.data = cur,
};
append_p1_rest_octets(&bv, p1ro, notif);
}
return GSM_MACBLOCK_LEN;
}
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,
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;
memset(out_buf, 0, sizeof(*pt2));
pt2->proto_discr = GSM48_PDISC_RR;
pt2->msg_type = GSM48_MT_RR_PAG_REQ_2;
pt2->pag_mode = GSM48_PM_NORMAL;
pt2->cneed1 = cneed1;
pt2->cneed2 = cneed2;
rc = tmsi_mi_to_uint(&tmsi, tmsi1_lv);
if (rc == 0)
pt2->tmsi1 = tmsi;
rc = tmsi_mi_to_uint(&tmsi, tmsi2_lv);
if (rc == 0)
pt2->tmsi2 = tmsi;
cur = out_buf + sizeof(*pt2);
if (identity3_lv)
cur = tlv_put(pt2->data, GSM48_IE_MOBILE_ID, identity3_lv[0], identity3_lv+1);
pt2->l2_plen = L2_PLEN(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, 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));
pt3->proto_discr = GSM48_PDISC_RR;
pt3->msg_type = GSM48_MT_RR_PAG_REQ_3;
pt3->pag_mode = GSM48_PM_NORMAL;
pt3->cneed1 = cneed1;
pt3->cneed2 = cneed2;
rc = tmsi_mi_to_uint(&tmsi, tmsi1_lv);
if (rc == 0)
pt3->tmsi1 = tmsi;
rc = tmsi_mi_to_uint(&tmsi, tmsi2_lv);
if (rc == 0)
pt3->tmsi2 = tmsi;
rc = tmsi_mi_to_uint(&tmsi, tmsi3_lv);
if (rc == 0)
pt3->tmsi3 = tmsi;
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. */
pt3->l2_plen = L2_PLEN(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 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 };
static struct paging_record *dequeue_pr(struct llist_head *group_q)
{
struct paging_record *pr;
pr = llist_entry(group_q->next, struct paging_record, list);
llist_del(&pr->list);
return pr;
}
static int pr_is_imsi(struct paging_record *pr)
{
if ((pr->u.normal.identity_lv[1] & 7) == GSM_MI_TYPE_IMSI)
return 1;
else
return 0;
}
static void sort_pr_tmsi_imsi(struct paging_record *pr[], unsigned int n)
{
int i, j;
struct paging_record *t;
if (n < 2)
return;
/* simple bubble sort */
for (i = n-2; i >= 0; i--) {
for (j=0; j<=i ; j++) {
if (pr_is_imsi(pr[j]) > pr_is_imsi(pr[j+1])) {
t = pr[j];
pr[j] = pr[j+1];
pr[j+1] = t;
}
}
}
}
static void build_p1_rest_octets(struct p1_rest_octets *p1ro, struct gsm_bts *bts)
{
memset(p1ro, 0, sizeof(*p1ro));
p1ro->nln_pch.present = false;
p1ro->packet_page_ind[0] = false;
p1ro->packet_page_ind[1] = false;
p1ro->r8_present = true;
p1ro->r8.prio_ul_access = false;
p1ro->r8.etws_present = true;
unsigned int offset = bts->etws.page_size * bts->etws.next_page;
if (bts->etws.next_page == 0) {
p1ro->r8.etws.is_first = true;
p1ro->r8.etws.page_nr = bts->etws.num_pages;
} else {
p1ro->r8.etws.is_first = false;
p1ro->r8.etws.page_nr = bts->etws.next_page + 1;
}
p1ro->r8.etws.page = bts->etws.prim_notif + offset;
/* last page may be smaller than first pages */
if (bts->etws.next_page < bts->etws.num_pages-1)
p1ro->r8.etws.page_bytes = bts->etws.page_size;
else
p1ro->r8.etws.page_bytes = bts->etws.prim_notif_len - offset;
bts->etws.next_page = (bts->etws.next_page + 1) % bts->etws.num_pages;
}
/* generate paging message for given gsm time */
int paging_gen_msg(struct paging_state *ps, uint8_t *out_buf, struct gsm_time *gt,
int *is_empty)
{
struct llist_head *group_q;
struct gsm_bts *bts = ps->bts;
int group;
int len;
/* This will have no effect on behavior of this function, we just need
* need to check the congestion status of the queue from time to time. */
check_congestion(ps);
*is_empty = 0;
bts->load.ccch.pch_total += 1;
group = get_pag_subch_nr(ps, gt);
if (group < 0) {
LOGP(DPAG, LOGL_ERROR,
"Paging called for GSM wrong time: FN %d/%d/%d/%d.\n",
gt->fn, gt->t1, gt->t2, gt->t3);
return -1;
}
group_q = &ps->paging_queue[group];
if (ps->bts->etws.prim_notif) {
struct p1_rest_octets p1ro;
build_p1_rest_octets(&p1ro, bts);
/* we intentioanally don't try to add notifications here, as ETWS is more critical */
len = fill_paging_type_1(out_buf, empty_id_lv, 0, NULL, 0, &p1ro, NULL);
} else if (llist_empty(group_q)) {
struct p1_rest_octets p1ro;
memset(&p1ro, 0, sizeof(p1ro));
/* Use NLN to notify MS about ongoing VGCS/VBS calls.
* This is required to make the phone read the NCH to get an updated list of ongoing calls.
* Without this the phone will not allow making VGCS/VBS calls. */
p1ro.nln_pch.present = (bts->asci.pos_nch >= 0);
p1ro.nln_pch.nln = bts->asci.nln;
p1ro.nln_pch.nln_status = bts->asci.nln_status;
/* There is nobody to be paged, send Type1 with two empty ID */
//DEBUGP(DPAG, "Tx PAGING TYPE 1 (empty)\n");
len = fill_paging_type_1(out_buf, empty_id_lv, 0, NULL, 0, &p1ro, NULL);
*is_empty = 1;
} else {
struct paging_record *pr[4];
unsigned int num_pr = 0, macblock = 0;
time_t now = time(NULL);
unsigned int i, num_imsi = 0;
bts->load.ccch.pch_used += 1;
/* get (if we have) up to four paging records */
for (i = 0; i < ARRAY_SIZE(pr); i++) {
if (llist_empty(group_q))
break;
pr[i] = dequeue_pr(group_q);
/* check for MAC block */
if (pr[i]->type == PAGING_RECORD_MACBLOCK) {
macblock = 1;
break;
}
num_pr++;
/* count how many IMSIs are among them */
if (pr_is_imsi(pr[i]))
num_imsi++;
}
/* Handle MAC block (from the PCU) */
if (macblock) {
/* re-add normal paging records */
for (i = 0; i < num_pr; i++)
llist_add(&pr[i]->list, group_q);
/* get MAC block message and free record */
memcpy(out_buf, pr[num_pr]->u.macblock.msg,
GSM_MACBLOCK_LEN);
/* send a confirmation back (if required) */
if (pr[num_pr]->u.macblock.confirm)
pcu_tx_data_cnf(pr[num_pr]->u.macblock.msg_id, PCU_IF_SAPI_PCH_2);
talloc_free(pr[num_pr]);
return GSM_MACBLOCK_LEN;
}
/* make sure the TMSIs are ahead of the IMSIs in the array */
sort_pr_tmsi_imsi(pr, num_pr);
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[3]->u.normal.identity_lv,
&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,
&p2ro);
if (num_pr == 4) {
/* re-add #4 for next time */
llist_add(&pr[3]->list, group_q);
pr[3] = NULL;
}
} else if (num_pr == 1) {
DEBUGP(DPAG, "Tx PAGING TYPE 1 (1 xMSI,1 empty)\n");
/* TODO: check if we can include an ASCI notification */
len = fill_paging_type_1(out_buf,
pr[0]->u.normal.identity_lv,
pr[0]->u.normal.chan_needed,
NULL, 0, NULL, NULL);
} else {
/* 2 (any type) or
* 3 or 4, of which only 2 will be sent */
DEBUGP(DPAG, "Tx PAGING TYPE 1 (2 xMSI)\n");
/* TODO: check if we can include an ASCI notification */
len = fill_paging_type_1(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, NULL, NULL);
if (num_pr >= 3) {
/* re-add #4 for next time */
llist_add(&pr[2]->list, group_q);
pr[2] = NULL;
}
if (num_pr == 4) {
/* re-add #4 for next time */
llist_add(&pr[3]->list, group_q);
pr[3] = NULL;
}
}
for (i = 0; i < num_pr; i++) {
/* skip those that we might have re-added above */
if (pr[i] == NULL)
continue;
rate_ctr_inc2(bts->ctrs, BTS_CTR_PAGING_SENT);
/* check if we can expire the paging record,
* or if we need to re-queue it */
if (pr[i]->u.normal.expiration_time <= now) {
talloc_free(pr[i]);
ps->num_paging--;
LOGP(DPAG, LOGL_INFO, "Removed paging record, queue_len=%u\n",
ps->num_paging);
} else
llist_add_tail(&pr[i]->list, group_q);
}
}
memset(out_buf+len, 0x2B, GSM_MACBLOCK_LEN-len);
return len;
}
int paging_si_update(struct paging_state *ps, struct gsm48_control_channel_descr *chan_desc)
{
LOGP(DPAG, LOGL_INFO, "Paging SI update\n");
ps->chan_desc = *chan_desc;
/* FIXME: do we need to re-sort the old paging_records? */
return 0;
}
static int paging_signal_cbfn(unsigned int subsys, unsigned int signal, void *hdlr_data,
void *signal_data)
{
if (subsys == SS_GLOBAL && signal == S_NEW_SYSINFO) {
struct gsm_bts *bts = signal_data;
struct paging_state *ps = bts->paging_state;
struct gsm48_system_information_type_3 *si3 = (void *) bts->si_buf[SYSINFO_TYPE_3];
paging_si_update(ps, &si3->control_channel_desc);
}
return 0;
}
static int initialized = 0;
struct paging_state *paging_init(struct gsm_bts *bts,
unsigned int num_paging_max,
unsigned int paging_lifetime)
{
struct paging_state *ps;
unsigned int i;
ps = talloc_zero(bts, struct paging_state);
if (!ps)
return NULL;
ps->bts = bts;
ps->paging_lifetime = paging_lifetime;
ps->num_paging_max = num_paging_max;
ps->cs_priority_active = false;
for (i = 0; i < ARRAY_SIZE(ps->paging_queue); i++)
INIT_LLIST_HEAD(&ps->paging_queue[i]);
if (!initialized) {
osmo_signal_register_handler(SS_GLOBAL, paging_signal_cbfn, NULL);
initialized = 1;
}
return ps;
}
void paging_config(struct paging_state *ps,
unsigned int num_paging_max,
unsigned int paging_lifetime)
{
ps->num_paging_max = num_paging_max;
ps->paging_lifetime = paging_lifetime;
}
void paging_reset(struct paging_state *ps)
{
int i;
for (i = 0; i < ARRAY_SIZE(ps->paging_queue); i++) {
struct llist_head *queue = &ps->paging_queue[i];
struct paging_record *pr, *pr2;
llist_for_each_entry_safe(pr, pr2, queue, list) {
llist_del(&pr->list);
talloc_free(pr);
ps->num_paging--;
}
}
if (ps->num_paging != 0)
LOGP(DPAG, LOGL_NOTICE, "num_paging != 0 after flushing all records?!?\n");
ps->num_paging = 0;
}
/**
* \brief Helper for the unit tests
*/
int paging_group_queue_empty(struct paging_state *ps, uint8_t grp)
{
if (grp >= ARRAY_SIZE(ps->paging_queue))
return 1;
return llist_empty(&ps->paging_queue[grp]);
}
int paging_queue_length(struct paging_state *ps)
{
return ps->num_paging;
}
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