diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/libbsc/rest_octets.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/src/libbsc/rest_octets.c b/src/libbsc/rest_octets.c index a22b8e674..abd621c8e 100644 --- a/src/libbsc/rest_octets.c +++ b/src/libbsc/rest_octets.c @@ -59,15 +59,16 @@ int rest_octets_si1(uint8_t *data, uint8_t *nch_pos, int is1800_net) } /* 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) +static inline bool append_eutran_neib_cell(struct bitvec *bv, struct gsm_bts *bts, uint8_t budget) { 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 */ + int16_t rem = budget - 6; /* account for mandatory stop bit and THRESH_E-UTRAN_high */ + uint8_t earfcn_budget; if (budget <= 6) - return; + return false; OSMO_ASSERT(budget <= SI2Q_MAX_LEN); @@ -87,6 +88,9 @@ static inline void append_eutran_neib_cell(struct bitvec *bv, struct gsm_bts *bt else rem--; + if (rem < 0) + return false; + /* 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) { @@ -104,6 +108,10 @@ static inline void append_eutran_neib_cell(struct bitvec *bv, struct gsm_bts *bt else { bts->e_offset++; rem -= earfcn_budget; + + if (rem < 0) + return false; + bitvec_set_bit(bv, 1); /* EARFCN: */ bitvec_set_uint(bv, e->arfcn[i], 16); @@ -146,10 +154,14 @@ static inline void append_eutran_neib_cell(struct bitvec *bv, struct gsm_bts *bt bitvec_set_uint(bv, e->qrxlm, 5); } else bitvec_set_bit(bv, 0); + + return true; } static inline void append_earfcn(struct bitvec *bv, struct gsm_bts *bts, uint8_t budget) { + bool appended; + unsigned int old = bv->cur_bit; /* save current position to make rollback possible */ int rem = budget - 25; if (rem <= 0) return; @@ -203,8 +215,11 @@ static inline void append_earfcn(struct bitvec *bv, struct gsm_bts *bts, uint8_t /* Repeated E-UTRAN Neighbour Cells */ bitvec_set_bit(bv, 1); - /* N. B: 25 bits are set in append_earfcn() - keep it in sync with budget adjustment below: */ - append_eutran_neib_cell(bv, bts, rem); + appended = append_eutran_neib_cell(bv, bts, rem); + if (!appended) { /* appending is impossible within current budget: rollback */ + bv->cur_bit = old; + return; + } /* stop bit - end of Repeated E-UTRAN Neighbour Cells sequence: */ bitvec_set_bit(bv, 0); |