diff options
| -rw-r--r-- | epan/dissectors/packet-bssgp.c | 103 |
1 files changed, 85 insertions, 18 deletions
diff --git a/epan/dissectors/packet-bssgp.c b/epan/dissectors/packet-bssgp.c index 875516dd19..9fe4678eeb 100644 --- a/epan/dissectors/packet-bssgp.c +++ b/epan/dissectors/packet-bssgp.c @@ -41,6 +41,7 @@ #include <math.h> #include <glib.h> #include <epan/packet.h> +#include <prefs.h> /*#define BSSGP_DEBUG*/ #define BSSGP_LITTLE_ENDIAN FALSE @@ -55,12 +56,16 @@ #define BSSGP_SEP ", " #define BSSGP_NOT_DECODED "< Not decoded yet >" #define BSSGP_UNKNOWN -1 +static int bssgp_decode_nri = 0; +static int bssgp_nri_length = 4; static dissector_handle_t bssgp_handle; static dissector_handle_t llc_handle; static dissector_handle_t rrlp_handle; static dissector_handle_t data_handle; +module_t *bssgp_module; +void proto_reg_handoff_bssgp(void); /* Initialize the protocol and registered fields */ static int proto_bssgp = -1; @@ -71,6 +76,7 @@ static int hf_bssgp_mnc = -1; static int hf_bssgp_lac = -1; static int hf_bssgp_rac = -1; static int hf_bssgp_ci = -1; +static int hf_bssgp_nri = -1; static int hf_bssgp_imsi = -1; static int hf_bssgp_imei = -1; static int hf_bssgp_imeisv = -1; @@ -410,6 +416,42 @@ get_masked_guint8(guint8 value, guint8 mask) { return (value & mask) >> i; } +static guint16 +get_masked_guint16(guint16 value, guint16 mask) { + const guint16 MASK_BIT_1 = 0x01; + guint8 i = 0; + + while (!((mask >> i) & MASK_BIT_1)) { + i++; + if (i > 15) return 0; + } + return (value & mask) >> i; +} + +static gint32 +make_mask32(guint8 num_bits, guint8 shift_value) { + const guint32 LEFT_MOST_1 = 0x80000000; + int i; + guint32 mask = LEFT_MOST_1; + + for (i = 0; i < (num_bits - 1); i++) { + mask = (mask >> 1) | LEFT_MOST_1; + } + return mask >> shift_value; +} + +static guint32 +get_masked_guint32(guint32 value, guint32 mask) { + const guint16 MASK_BIT_1 = 0x01; + guint8 i = 0; + + while (!((mask >> i) & MASK_BIT_1)) { + i++; + if (i > 31) return 0; + } + return (value & mask) >> i; +} + static guint8 tvb_get_masked_guint8(tvbuff_t *tvb, int offset, guint8 mask) { guint8 value = tvb_get_guint8(tvb, offset); @@ -1189,6 +1231,27 @@ bssgp_proto_handoff(bssgp_ie_t *ie, build_info_t *bi, int ie_start_offset, disse } } +static void +decode_nri(proto_tree *tf, build_info_t *bi, guint32 tmsi_tlli) { + const guint32 LOCAL_TLLI_MASK = 0xc0000000; + const guint32 FOREIGN_TLLI_MASK = 0x80000000; + guint16 nri; + + if (bssgp_decode_nri && (bssgp_nri_length > 0) && + (((tmsi_tlli & LOCAL_TLLI_MASK) == LOCAL_TLLI_MASK) || + ((tmsi_tlli & FOREIGN_TLLI_MASK) == FOREIGN_TLLI_MASK))) { + nri = get_masked_guint32(tmsi_tlli, make_mask32(bssgp_nri_length, 8)); + if (tf) { + proto_tree_add_uint_hidden(tf, hf_bssgp_nri, bi->tvb, bi->offset, 4, + nri); + } + if (check_col(bi->pinfo->cinfo, COL_INFO)) { + col_append_sep_fstr(bi->pinfo->cinfo, COL_INFO, BSSGP_SEP, + "NRI %u", nri); + } + } +} + static void decode_mobile_identity(bssgp_ie_t *ie, build_info_t *bi, int ie_start_offset) { #define MAX_NUM_IMSI_DIGITS 15 @@ -1296,18 +1359,18 @@ decode_mobile_identity(bssgp_ie_t *ie, build_info_t *bi, int ie_start_offset) { break; case BSSGP_MOBILE_IDENTITY_TYPE_TMSI_PTMSI: tmsi = tvb_get_ntohl(bi->tvb, bi->offset); + if (check_col(bi->pinfo->cinfo, COL_INFO)) { + col_append_sep_fstr(bi->pinfo->cinfo, COL_INFO, BSSGP_SEP, + "TMSI/P-TMSI %0x04x", tmsi); + } if (bi->bssgp_tree) { proto_tree_add_item(tf, hf_bssgp_tmsi_ptmsi, bi->tvb, bi->offset, 4, BSSGP_LITTLE_ENDIAN); proto_item_append_text(ti, ": %#04x", tmsi); } + decode_nri(tf, bi, tmsi); bi->offset += 4; - - if (check_col(bi->pinfo->cinfo, COL_INFO)) { - col_append_sep_fstr(bi->pinfo->cinfo, COL_INFO, BSSGP_SEP, - "TMSI/P-TMSI %0x04x", tmsi); - } - return; + break; default: ; }; @@ -2743,6 +2806,7 @@ decode_iei_tlli(bssgp_ie_t *ie, build_info_t *bi, int ie_start_offset) { col_append_sep_fstr(bi->pinfo->cinfo, COL_INFO, BSSGP_SEP, "TLLI %#4x", tlli); } + decode_nri(bi->bssgp_tree, bi, tlli); } static void @@ -5673,6 +5737,11 @@ proto_register_bssgp(void) FT_STRING, BASE_NONE, NULL, 0x0, "", HFILL } }, + { &hf_bssgp_nri, + { "NRI", "bssgp.nri", + FT_UINT16, BASE_DEC, NULL, 0x0, + "", HFILL } + }, }; /* Setup protocol subtree array */ @@ -5726,6 +5795,16 @@ proto_register_bssgp(void) proto_register_field_array(proto_bssgp, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); register_dissector("bssgp", dissect_bssgp, proto_bssgp); + + /* Register configuration options */ + bssgp_module = prefs_register_protocol(proto_bssgp, proto_reg_handoff_bssgp); + prefs_register_bool_preference(bssgp_module, "decode_nri", + "Decode NRI", + "Decode NRI (for use with SGSN in Pool)", + &bssgp_decode_nri); + prefs_register_uint_preference(bssgp_module, "nri_length", "NRI length", + "NRI length, in bits", + 10, &bssgp_nri_length); } /* If this dissector uses sub-dissector registration add a registration routine. @@ -5738,15 +5817,3 @@ proto_reg_handoff_bssgp(void) rrlp_handle = find_dissector("rrlp"); data_handle = find_dissector("data"); } - - - - - - - - - - - - |