diff options
| -rw-r--r-- | epan/dissectors/packet-gtpv2.c | 71 |
1 files changed, 59 insertions, 12 deletions
diff --git a/epan/dissectors/packet-gtpv2.c b/epan/dissectors/packet-gtpv2.c index c73d0ab1fb..e05ec23d12 100644 --- a/epan/dissectors/packet-gtpv2.c +++ b/epan/dissectors/packet-gtpv2.c @@ -64,10 +64,12 @@ static int hf_gtpv2_flags = -1; static int hf_gtpv2_version = -1; static int hf_gtpv2_p = -1; static int hf_gtpv2_t = -1; +static int hf_gtpv2_mp = -1; static int hf_gtpv2_message_type = -1; static int hf_gtpv2_msg_length = -1; static int hf_gtpv2_teid = -1; static int hf_gtpv2_seq = -1; +static int hf_gtpv2_msg_prio = -1; static int hf_gtpv2_spare = -1; @@ -7028,9 +7030,9 @@ dissect_gtpv2_ie_common(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, static int dissect_gtpv2(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* data _U_) { - proto_tree *gtpv2_tree, *flags_tree; + proto_tree *gtpv2_tree; proto_item *ti; - guint8 message_type, t_flag, p_flag, cause_aux; + guint8 message_type, t_flag, p_flag, mp_flag, cause_aux; int offset = 0; guint16 msg_length; tvbuff_t *msg_tvb; @@ -7039,6 +7041,15 @@ dissect_gtpv2(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* data gtpv2_conv_info_t *gtpv2_info; session_args_t *args = NULL; gtpv2_hdr_t * gtpv2_hdr = NULL; + guint64 gtpv2_hdr_flags; + + static const int * gtpv2_flags[] = { + &hf_gtpv2_version, + &hf_gtpv2_p, + &hf_gtpv2_t, + &hf_gtpv2_mp, + NULL + }; gtpv2_hdr = wmem_new0(wmem_packet_scope(), gtpv2_hdr_t); @@ -7054,7 +7065,6 @@ dissect_gtpv2(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* data col_set_str(pinfo->cinfo, COL_INFO, val_to_str_ext_const(message_type, >pv2_message_type_vals_ext, "Unknown")); - p_flag = (tvb_get_guint8(tvb, offset) & 0x10) >> 4; msg_length = tvb_get_ntohs(tvb, offset + 2); ti = proto_tree_add_item(tree, proto_gtpv2, tvb, offset, msg_length + 4, ENC_NA); gtpv2_tree = proto_item_add_subtree(ti, ett_gtpv2); @@ -7102,15 +7112,32 @@ dissect_gtpv2(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* data * (n+3) Spare * Figure 5.1-1: General format of GTPv2 Header for Control Plane */ - gtpv2_hdr->flags = tvb_get_guint8(tvb, offset); - ti = proto_tree_add_uint(gtpv2_tree, hf_gtpv2_flags, tvb, offset, 1, gtpv2_hdr->flags); - flags_tree = proto_item_add_subtree(ti, ett_gtpv2_flags); + + /* 5.4 EPC specific GTP-C header + * Bits 8 7 6 5 4 3 2 1 + * Octets 1 Version P T=1 MP Spare Spare + * 2 Message Type + * 3 Message Length (1st Octet) + * 4 Message Length (2nd Octet) + * 5 Tunnel Endpoint Identifier (1st Octet) + * 6 Tunnel Endpoint Identifier (2nd Octet) + * 7 Tunnel Endpoint Identifier (3rd Octet) + * 8 Tunnel Endpoint Identifier (4th Octet) + * 9 Sequence Number (1st Octet) + * 10 Sequence Number (2nd Octet) + * 11 Sequence Number (3rd Octet) + * 12 Message Priority Spare + */ /* Octet 1 */ - t_flag = (tvb_get_guint8(tvb, offset) & 0x08) >> 3; - proto_tree_add_item(flags_tree, hf_gtpv2_version, tvb, offset, 1, ENC_BIG_ENDIAN); - proto_tree_add_item(flags_tree, hf_gtpv2_p, tvb, offset, 1, ENC_BIG_ENDIAN); - proto_tree_add_item(flags_tree, hf_gtpv2_t, tvb, offset, 1, ENC_BIG_ENDIAN); + proto_tree_add_bitmask_with_flags_ret_uint64(gtpv2_tree, tvb, offset, hf_gtpv2_flags, + ett_gtpv2_flags, gtpv2_flags, ENC_BIG_ENDIAN, BMT_NO_FALSE | BMT_NO_INT, >pv2_hdr_flags); + + gtpv2_hdr->flags = (guint8)gtpv2_hdr_flags; + p_flag = (gtpv2_hdr->flags & 0x10) >> 4; + t_flag = (gtpv2_hdr->flags & 0x08) >> 3; + mp_flag = (gtpv2_hdr->flags & 0x04) >> 2; + offset += 1; /* Octet 2 */ @@ -7132,8 +7159,18 @@ dissect_gtpv2(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* data proto_tree_add_item_ret_uint(gtpv2_tree, hf_gtpv2_seq, tvb, offset, 3, ENC_BIG_ENDIAN, &seq_no); offset += 3; - /* Spare 1 octet */ - proto_tree_add_item(gtpv2_tree, hf_gtpv2_spare, tvb, offset, 1, ENC_BIG_ENDIAN); + /* Spare 1 octet or if the "MP" flag is set to "1", + * then bits 8 to 5 of octet 12 shall indicate the message priority. + */ + if (mp_flag) { + /* Bits 8 to 5 of octet 12 shall be encoded as the binary value of the Message Priority + * and it may take any value between 0 and 15, where 0 corresponds to the highest priority + * and 15 the lowest priority. + */ + proto_tree_add_item(gtpv2_tree, hf_gtpv2_msg_prio, tvb, offset, 1, ENC_BIG_ENDIAN); + }else{ + proto_tree_add_item(gtpv2_tree, hf_gtpv2_spare, tvb, offset, 1, ENC_BIG_ENDIAN); + } offset += 1; if (p_flag) { @@ -7222,6 +7259,11 @@ void proto_register_gtpv2(void) FT_UINT8, BASE_DEC, NULL, 0x08, "If TEID field is present or not", HFILL} }, + { &hf_gtpv2_mp, + {"Message Priority(MP)", "gtpv2.mp", + FT_UINT8, BASE_DEC, NULL, 0x04, + "If Message Priority field is present or not", HFILL} + }, { &hf_gtpv2_message_type, {"Message Type", "gtpv2.message_type", FT_UINT8, BASE_DEC|BASE_EXT_STRING, >pv2_message_type_vals_ext, 0x0, @@ -7242,6 +7284,11 @@ void proto_register_gtpv2(void) FT_UINT32, BASE_HEX_DEC, NULL, 0x0, "SEQ", HFILL} }, + { &hf_gtpv2_msg_prio, + {"Message Priority", "gtpv2.mp", + FT_UINT8, BASE_HEX_DEC, NULL, 0xf0, + NULL, HFILL} + }, { &hf_gtpv2_spare, {"Spare", "gtpv2.spare", FT_UINT16, BASE_DEC, NULL, 0x0, |