Restructure SI2quater generation
In preparation for extended SI2q messages:
* add SI2q-specific accessor macro
* add *_offset variables to gsm_bts struct
* internalize memory check while generating rest octets - introduce
budget concept (number of bits available in a given message)
* internalize *arfcn_size() functions as they are not needed outside of
si2q_num() anymore
* change rest octets generation to work with gsm_bts struct directly
* do not generate rest octets if no SI2q is necessary
* adjust unit tests accordingly (cosmetic changes only to avoid
regressions)
Requires: I92e12e91605bdab9916a3f665705287572434f74 in libosmocore
Change-Id: Ib554cf7ffc949a321571e1ae2ada1160e1b35fa6
Related: RT#8792
diff --git a/openbsc/src/libbsc/rest_octets.c b/openbsc/src/libbsc/rest_octets.c
index af660f1..950e570 100644
--- a/openbsc/src/libbsc/rest_octets.c
+++ b/openbsc/src/libbsc/rest_octets.c
@@ -58,24 +58,55 @@
return bv.data_len;
}
-/* Append Repeated E-UTRAN Neighbour Cell to bitvec:
- * see 3GPP TS 44.018 Table 10.5.2.33b.1
- */
-static inline void append_eutran_neib_cell(struct bitvec *bv,
- const struct osmo_earfcn_si2q *e)
+/* Append Repeated E-UTRAN Neighbour Cell to bitvec: see 3GPP TS 44.018 Table 10.5.2.33b.1 */
+static inline void append_eutran_neib_cell(struct bitvec *bv, struct gsm_bts *bts, uint8_t budget)
{
- unsigned i;
+ const struct osmo_earfcn_si2q *e = &bts->si_common.si2quater_neigh_list;
+ unsigned i, skip = 0;
+ size_t offset = bts->e_offset;
+ uint8_t rem = budget - 6, earfcn_budget; /* account for mandatory stop bit and THRESH_E-UTRAN_high */
+ /* first we have to properly adjust budget requirements */
+ if (e->prio_valid) /* E-UTRAN_PRIORITY: 3GPP TS 45.008*/
+ rem -= 4;
+ else
+ rem--;
+
+ if (e->thresh_lo_valid) /* THRESH_E-UTRAN_low: */
+ rem -= 6;
+ else
+ rem--;
+
+ if (e->qrxlm_valid) /* E-UTRAN_QRXLEVMIN: */
+ rem -= 6;
+ else
+ rem--;
+
+ /* now we can proceed with actually adding EARFCNs within adjusted budget limit */
for (i = 0; i < e->length; i++) {
if (e->arfcn[i] != OSMO_EARFCN_INVALID) {
- bitvec_set_bit(bv, 1); /* EARFCN: */
- bitvec_set_uint(bv, e->arfcn[i], 16);
+ if (skip < offset) {
+ skip++; /* ignore EARFCNs added on previous calls */
+ } else {
+ earfcn_budget = 17; /* computer budget per-EARFCN */
+ if (OSMO_EARFCN_MEAS_INVALID == e->meas_bw[i])
+ earfcn_budget++;
+ else
+ earfcn_budget += 4;
- if (OSMO_EARFCN_MEAS_INVALID == e->meas_bw[i])
- bitvec_set_bit(bv, 0);
- else {
- /* Measurement Bandwidth: 9.1.54 */
- bitvec_set_bit(bv, 1);
- bitvec_set_uint(bv, e->meas_bw[i], 3);
+ if (rem - earfcn_budget < 0) {
+ break;
+ } else {
+ bts->e_offset++;
+ bitvec_set_bit(bv, 1); /* EARFCN: */
+ bitvec_set_uint(bv, e->arfcn[i], 16);
+
+ if (OSMO_EARFCN_MEAS_INVALID == e->meas_bw[i])
+ bitvec_set_bit(bv, 0);
+ else { /* Measurement Bandwidth: 9.1.54 */
+ bitvec_set_bit(bv, 1);
+ bitvec_set_uint(bv, e->meas_bw[i], 3);
+ }
+ }
}
}
}
@@ -83,6 +114,8 @@
/* stop bit - end of EARFCN + Measurement Bandwidth sequence */
bitvec_set_bit(bv, 0);
+ /* Note: we don't support different EARFCN arrays each with different priority, threshold etc. */
+
if (e->prio_valid) {
/* E-UTRAN_PRIORITY: 3GPP TS 45.008*/
bitvec_set_bit(bv, 1);
@@ -108,8 +141,7 @@
bitvec_set_bit(bv, 0);
}
-static inline void append_earfcn(struct bitvec *bv,
- const struct osmo_earfcn_si2q *e)
+static inline void append_earfcn(struct bitvec *bv, struct gsm_bts *bts, uint8_t budget)
{
/* Additions in Rel-5: */
bitvec_set_bit(bv, H);
@@ -158,9 +190,8 @@
/* Repeated E-UTRAN Neighbour Cells */
bitvec_set_bit(bv, 1);
- /* Note: we don't support different EARFCN arrays each with different
- priority, threshold etc. */
- append_eutran_neib_cell(bv, e);
+ /* N. B: 25 bits are set in append_earfcn() - keep it in sync with budget adjustment below: */
+ append_eutran_neib_cell(bv, bts, budget - 25);
/* stop bit - end of Repeated E-UTRAN Neighbour Cells sequence: */
bitvec_set_bit(bv, 0);
@@ -180,12 +211,37 @@
bitvec_set_bit(bv, L);
}
-/* Append single FDD UARFCN */
-static inline int append_utran_fdd(struct bitvec *bv, uint16_t u, int *sc,
- size_t length)
+static inline int f0_helper(int *sc, size_t length, uint8_t *chan_list)
{
- int f0, w[RANGE_ENC_MAX_ARFCNS] = { 0 };
- uint8_t chan_list[16] = {0};
+ int w[RANGE_ENC_MAX_ARFCNS] = { 0 };
+
+ return range_encode(ARFCN_RANGE_1024, sc, length, w, 0, chan_list);
+}
+
+/* Estimate how many bits it'll take to append single FDD UARFCN */
+static inline int append_utran_fdd_length(uint16_t u, int *sc, size_t sc_len, size_t length)
+{
+ uint8_t chan_list[16] = { 0 };
+ int tmp[sc_len], f0;
+
+ memcpy(tmp, sc, sizeof(tmp));
+
+ f0 = f0_helper(tmp, length, chan_list);
+ if (f0 < 0)
+ return f0;
+
+ return 21 + range1024_p(length);
+}
+
+/* Append single FDD UARFCN */
+static inline int append_utran_fdd(struct bitvec *bv, uint16_t u, int *sc, size_t length)
+{
+ uint8_t chan_list[16] = { 0 };
+ int f0 = f0_helper(sc, length, chan_list);
+
+ if (f0 < 0)
+ return f0;
+
/* Repeated UTRAN FDD Neighbour Cells */
bitvec_set_bit(bv, 1);
@@ -193,10 +249,6 @@
bitvec_set_bit(bv, 0);
bitvec_set_uint(bv, u, 14);
- f0 = range_encode(ARFCN_RANGE_1024, sc, length, w, 0, chan_list);
- if (f0 < 0)
- return f0;
-
/* FDD_Indic0: parameter value '0000000000' is a member of the set? */
bitvec_set_bit(bv, f0);
/* NR_OF_FDD_CELLS */
@@ -205,15 +257,17 @@
f0 = bv->cur_bit;
bitvec_add_range1024(bv, (struct gsm48_range_1024 *)chan_list);
bv->cur_bit = f0 + range1024_p(length);
- return 0;
+
+ return 21 + range1024_p(length);
}
/* Append multiple FDD UARFCNs */
-static inline int append_uarfcns(struct bitvec *bv, const uint16_t *u,
- const uint16_t *sc, size_t length)
+static inline int append_uarfcns(struct bitvec *bv, struct gsm_bts *bts, uint8_t budget)
{
- int i, j, k, rc, st = 0, a[length];
- uint16_t cu = u[0]; /* caller ensures that length is positive */
+ const uint16_t *u = bts->si_common.data.uarfcn_list, *sc = bts->si_common.data.scramble_list;
+ int i, j, k, rc, st = 0, a[bts->si_common.uarfcn_length];
+ uint16_t cu = u[bts->u_offset]; /* caller ensures that length is positive */
+ uint8_t rem = budget - 7; /* account for constant bits right away */
/* 3G Neighbour Cell Description */
bitvec_set_bit(bv, 1);
@@ -227,24 +281,41 @@
/* No Bandwidth_FDD */
bitvec_set_bit(bv, 0);
- for (i = 0; i < length; i++) {
+ for (i = bts->u_offset; i < bts->si_common.uarfcn_length; i++) {
for (j = st, k = 0; j < i; j++)
a[k++] = sc[j]; /* copy corresponding SCs */
+
if (u[i] != cu) { /* we've reached new UARFCN */
- rc = append_utran_fdd(bv, cu, a, k);
- if (rc < 0)
+ rc = append_utran_fdd_length(cu, a, bts->si_common.uarfcn_length, k);
+ if (rc < 0) { /* estimate bit length requirements */
return rc;
+ }
+
+ if (rem - rc < 0) {
+ break; /* we have ran out of budget in current SI2q */
+ } else {
+ rem -= append_utran_fdd(bv, cu, a, k);
+ bts->u_offset++;
+ }
cu = u[i];
st = i; /* update start position */
}
}
- /* add last UARFCN not covered by previous cycle */
- for (i = st, k = 0; i < length; i++)
- a[k++] = sc[i];
- rc = append_utran_fdd(bv, cu, a, k);
- if (rc < 0)
- return rc;
+ if (rem > 22) { /* add last UARFCN not covered by previous cycle if it could possibly fit into budget */
+ for (i = st, k = 0; i < bts->si_common.uarfcn_length; i++)
+ a[k++] = sc[i];
+
+ rc = append_utran_fdd_length(cu, a, bts->si_common.uarfcn_length, k);
+ if (rc < 0) {
+ return rc;
+ }
+
+ if (rem - rc >= 0) {
+ rem -= append_utran_fdd(bv, cu, a, k);
+ bts->u_offset++;
+ }
+ }
/* stop bit - end of Repeated UTRAN FDD Neighbour Cells */
bitvec_set_bit(bv, 0);
@@ -256,11 +327,9 @@
}
/* generate SI2quater rest octets: 3GPP TS 44.018 § 10.5.2.33b */
-int rest_octets_si2quater(uint8_t *data, uint8_t index, uint8_t count, const struct osmo_earfcn_si2q *e,
- const uint16_t *u, const uint16_t *sc, size_t u_len)
+int rest_octets_si2quater(uint8_t *data, struct gsm_bts *bts)
{
int rc;
- unsigned sz;
struct bitvec bv;
bv.data = data;
bv.data_len = 20;
@@ -273,11 +342,10 @@
/* MP_CHANGE_MARK */
bitvec_set_bit(&bv, 0);
- /* we do not support multiple si2quater messages at the moment: */
/* SI2quater_INDEX */
- bitvec_set_uint(&bv, index, 4);
+ bitvec_set_uint(&bv, bts->si2q_index, 4);
/* SI2quater_COUNT */
- bitvec_set_uint(&bv, count, 4);
+ bitvec_set_uint(&bv, bts->si2q_count, 4);
/* No Measurement_Parameters Description */
bitvec_set_bit(&bv, 0);
@@ -294,22 +362,12 @@
/* No extension (length) */
bitvec_set_bit(&bv, 0);
- if (u_len) {
- sz = uarfcn_size(u, sc, u_len);
+ if (bts->si_common.uarfcn_length) {
/* Even if we do not append EARFCN we still need to set 3 bits */
- if (sz + bv.cur_bit + 3 > SI2Q_MAX_LEN) {
- LOGP(DRR, LOGL_ERROR, "SI2quater: not enough memory to "
- "add UARFCNs bits, current %u + required %u + "
- "reminder %u > max %u\n", bv.cur_bit, sz, 3,
- SI2Q_MAX_LEN);
- return -ENOMEM;
- }
-
- rc = append_uarfcns(&bv, u, sc, u_len);
+ rc = append_uarfcns(&bv, bts, SI2Q_MAX_LEN - (bv.cur_bit + 3));
if (rc < 0) {
- LOGP(DRR, LOGL_ERROR, "SI2quater: failed to append %zu "
- "UARFCNs due to range encoding failure: %s\n",
- u_len, strerror(-rc));
+ LOGP(DRR, LOGL_ERROR, "SI2quater: failed to append %zu UARFCNs due to range encoding failure: %s\n",
+ bts->si_common.uarfcn_length, strerror(-rc));
return rc;
}
} else { /* No 3G Neighbour Cell Description */
@@ -321,15 +379,14 @@
/* No GPRS_3G_MEASUREMENT Parameters Descr. */
bitvec_set_bit(&bv, 0);
- if (e) {
- sz = earfcn_size(e);
- if (sz + bv.cur_bit > SI2Q_MAX_LEN) {
- LOGP(DRR, LOGL_ERROR, "SI2quater: not enough memory to "
- "add EARFCNs bits, current %u + required %u > max "
- "%u\n", bv.cur_bit, sz, SI2Q_MAX_LEN);
+ if (&bts->si_common.si2quater_neigh_list) { /* FIXME: use si2q_earfcn_count() in if */
+ append_earfcn(&bv, bts, SI2Q_MAX_LEN - bv.cur_bit);
+
+ /* FIXME: remove following check once multiple SI2q are properly supported */
+ if ((bts->e_offset != si2q_earfcn_count(&bts->si_common.si2quater_neigh_list)) ||
+ si2q_earfcn_count(&bts->si_common.si2quater_neigh_list) > 5)
return -ENOMEM;
- }
- append_earfcn(&bv, e);
+
} else {
/* No Additions in Rel-5: */
bitvec_set_bit(&bv, L);