diff options
| -rw-r--r-- | epan/dissectors/packet-gsm_a_rr.c | 97 |
1 files changed, 52 insertions, 45 deletions
diff --git a/epan/dissectors/packet-gsm_a_rr.c b/epan/dissectors/packet-gsm_a_rr.c index 1b2f9d9743..44a571da4f 100644 --- a/epan/dissectors/packet-gsm_a_rr.c +++ b/epan/dissectors/packet-gsm_a_rr.c @@ -2855,6 +2855,15 @@ de_rr_gprs_resumption(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo _U_, g /* * [3] 10.5.2.14d GPRS broadcast information */ +#define GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(x) \ + { \ + curr_bit_offset += x; \ + value -= x; \ + if (value <= 0) \ + { \ + goto end; \ + } \ + } static gint de_rr_rest_oct_gprs_cell_options(tvbuff_t *tvb, proto_tree *tree, gint bit_offset) @@ -2862,7 +2871,7 @@ de_rr_rest_oct_gprs_cell_options(tvbuff_t *tvb, proto_tree *tree, gint bit_offse proto_tree *subtree, *subtree2; proto_item *item, *item2; gint curr_bit_offset, curr_bit_offset_sav; - guint8 value; + gint16 value; curr_bit_offset = bit_offset; @@ -2897,65 +2906,63 @@ de_rr_rest_oct_gprs_cell_options(tvbuff_t *tvb, proto_tree *tree, gint bit_offse curr_bit_offset_sav = curr_bit_offset; subtree2 = proto_tree_add_subtree(subtree, tvb, curr_bit_offset>>3, -1, ett_gsm_rr_rest_octets_elem[DE_RR_REST_OCTETS_GPRS_CELL_OPTIONS_EXT_INFO], &item2, gsm_rr_rest_octets_elem_strings[DE_RR_REST_OCTETS_GPRS_CELL_OPTIONS_EXT_INFO].strptr); - value = tvb_get_bits8(tvb,curr_bit_offset,6); + value = (gint16)tvb_get_bits8(tvb,curr_bit_offset,6); proto_tree_add_uint(subtree2, hf_gsm_a_rr_extension_length, tvb, curr_bit_offset>>3, 1, value); curr_bit_offset += 6; value += 1; proto_item_set_len(item2,((curr_bit_offset+value)>>3) - (curr_bit_offset_sav>>3)+1); - if (gsm_rr_csn_flag(tvb, subtree, curr_bit_offset++, hf_gsm_a_rr_egprs_supported)) + if (gsm_rr_csn_flag(tvb, subtree2, curr_bit_offset, hf_gsm_a_rr_egprs_supported)) { + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_egprs_packet_channel_request, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); - curr_bit_offset += 1; + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_bep_period, tvb, curr_bit_offset, 4, ENC_BIG_ENDIAN); - curr_bit_offset += 4; - value -= 5; + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(4); + } + else + { + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); } - value -= 1; proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_pfc_feature_mode, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); - curr_bit_offset += 1; + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_dtm_support, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); - curr_bit_offset += 1; + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_bss_paging_coordination, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); - curr_bit_offset += 1; - value -= 3; - if (value > 0) - { /* Rel 4 extension */ - proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_ccn_active, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); - curr_bit_offset += 1; - proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_nw_ext_utbf, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); - curr_bit_offset += 1; - value -= 2; - if (value > 0) - { /* Rel 6 extension */ - proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_multiple_tbf_capability, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); - curr_bit_offset += 1; - proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_ext_utbf_no_data, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); - curr_bit_offset += 1; - proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_dtm_enhancements_capability, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); - curr_bit_offset += 1; - value -= 3; - if (gsm_rr_csn_flag(tvb, subtree2, curr_bit_offset++, hf_gsm_a_rr_msms_procedures)) - { - proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_dedicated_mode_mbms_notification_support, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); - curr_bit_offset += 1; - proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_mnci_support, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); - curr_bit_offset += 1; - value -= 2; - } - value -= 1; - if (value > 0) - { /* Rel 7 extension */ - proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_reduced_latency_access, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); - curr_bit_offset += 1; - value -= 1; - } - } + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); + /* Rel 4 extension */ + proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_ccn_active, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); + proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_nw_ext_utbf, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); + /* Rel 6 extension */ + proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_multiple_tbf_capability, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); + proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_ext_utbf_no_data, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); + proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_dtm_enhancements_capability, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); + if (gsm_rr_csn_flag(tvb, subtree2, curr_bit_offset, hf_gsm_a_rr_msms_procedures)) + { + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); + proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_dedicated_mode_mbms_notification_support, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); + proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_mnci_support, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); } + else + { + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); + } + /* Rel 7 extension */ + proto_tree_add_bits_item(subtree2, hf_gsm_a_rr_reduced_latency_access, tvb, curr_bit_offset, 1, ENC_BIG_ENDIAN); + GPRS_CELL_OPTIONS_CHECK_REMAINING_EXT_LEN(1); + /* Remaining (undecoded?) extensions */ curr_bit_offset += value; } - proto_item_set_len(item,((curr_bit_offset>>3) - (bit_offset>>3) + 1)); + end: + proto_item_set_len(item,((curr_bit_offset>>3) - (bit_offset>>3) + 1)); - return (curr_bit_offset - bit_offset); + return (curr_bit_offset - bit_offset); } static gint |