Ethereal-dev: [Ethereal-dev] [Fwd: GMM/SM + LLC + BSSGP Patch]
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From: Pilz Rene <rene.pilz@xxxxxx>
Date: Wed, 09 Feb 2005 21:47:32 +0100
HiThe patch which have submitted a time ago got somehow lost. Is there there a specific reason or happened it only by accident.
Please give me some feedback Thx & Regards Rene -- Dipl-Ing (FH) MSc. C.E René Pilz ftw. Telekommunications Research Center Vienna http://www.ftw.at Tech Gate Vienna, Donaucitystraße 1, A-1220 Wien Mobile: +43 664 8269871 Office: +43 1 5052830-13 Fax: +43 1 5052830-99
--- Begin Message ---From: Pilz Rene <rene.pilz@xxxxxx>Date: Fri, 28 Jan 2005 13:31:43 +0100Hi This patch solves several issues in different dissectors. BSSGP: - Does not dissect the LLC-PDU twice LLC:- Add CRC calculation to differ between ciphered and non-ciphered packets without taking care about the encryption bit. This solves crashes when the option "ignore ciphere bit" was activatedGMM/SM: - Dissect detach_type now correctly ( fixed by Miklos Szurdi ) - Dissect timer correctly ( fixed by Miklos Szurdi ) - Update SM causes for Release 6 ( Miklos Szurdi ) - Update service_type for Release 6 ( Miklos Szurdi ) - Rearange pco code like Guy Harris has suggested ( Guy Harris ) - reimplement dissection of IPv4 and IPv6 addresses - Fix offset in pdp_addr - Fix offset in Traffic Flow Template (tft) Please apply this patch. Regards Rene -- Dipl-Ing (FH) MSc. C.E René Pilz ftw. Telekommunications Research Center Vienna http://www.ftw.at Tech Gate Vienna, Donaucitystraße 1, A-1220 Wien Mobile: +43 664 8269871 Office: +43 1 5052830-13 Fax: +43 1 5052830-99--- epan/dissectors/packet-gsm_a.c (revision 13182) +++ epan/dissectors/packet-gsm_a.c (working copy) @@ -50,6 +50,12 @@ * Stage 3 * (3GPP TS 24.008 version 5.9.0 Release 5) * + * Reference [8] + * Mobile radio interface Layer 3 specification; + * Core network protocols; + * Stage 3 + * (3GPP TS 24.008 version 6.7.0 Release 6) + * * $Id$ * * Ethereal - Network traffic analyzer @@ -91,6 +97,8 @@ #include "packet-gsm_ss.h" #include "packet-gsm_a.h" +#include "packet-ppp.h" + /* PROTOTYPES/FORWARDS */ const value_string gsm_a_bssmap_msg_strings[] = { @@ -6997,10 +7005,10 @@ switch(oct&7) { - case 0: str="GPRS detach/re-attach required"; break; - case 1: str="IMSI detach/re-attach not required"; break; - case 2: str="Combined GPRS/IMSI detach/IMSI detach (after VLR failure)"; break; - default: str="Not specified"; + case 1: str="GPRS detach/re-attach required"; break; + case 2: str="IMSI detach/re-attach not required"; break; + case 3: str="Combined GPRS/IMSI detach/IMSI detach (after VLR failure)"; break; + default: str="Combined GPRS/IMSI detach/re-attach not required"; } switch(oct&8) @@ -9236,7 +9244,7 @@ } /* - * [7] 10.5.5.20 + * [8] 10.5.5.20 */ static guint8 de_gmm_service_type(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len, gchar *add_string) @@ -9261,6 +9269,7 @@ case 0: str="Signalling"; break; case 1: str="Data"; break; case 2: str="Paging Response"; break; + case 3: str="MBMS Notification Reponse"; break; default: str="reserved"; } @@ -9424,7 +9433,7 @@ case 0: str="sec"; val*=2; break; case 1: str="min"; break; case 2: str="min"; val*=6; break; - case 3: + case 7: proto_tree_add_text(tree, tvb, curr_offset, 1, "GPRS Timer: timer is deactivated"); @@ -9469,7 +9478,7 @@ case 0: str="sec"; val*=2; break; case 1: str="min"; break; case 2: str="min"; val*=6; break; - case 3: + case 7: proto_tree_add_text(tree, tvb, curr_offset, 1, "GPRS Timer: timer is deactivated"); @@ -9689,6 +9698,7 @@ guint32 curr_offset; guint curr_len; guchar oct; + struct e_in6_addr ipv6_addr; curr_len = len; add_string = add_string; @@ -9706,7 +9716,8 @@ guchar e_len; guint16 prot; tvbuff_t *l3_tvb; - static packet_info pco_pinfo; + dissector_handle_t handle = NULL; + static packet_info p_info; prot = tvb_get_guint8(tvb, curr_offset); prot <<= 8; @@ -9719,18 +9730,13 @@ { case 0x0001: { - guchar *addr; proto_tree_add_text(tree,tvb, curr_offset-3, 2, "Parameter: (%u) P-CSCF Address" , prot ); proto_tree_add_text(tree,tvb, curr_offset-1, 1, "Length: 0x%02x (%u)", e_len , e_len); - addr = (guchar*)tvb_get_ptr(tvb, curr_offset, 16); - - proto_tree_add_text(tree, - tvb, curr_offset, 16, - "IPv6: %4x:%4x:%4x:%4x:%4x:%4x:%4x:%4x", - (addr[0]<<8)| addr[1], (addr[2]<<8)| addr[3], - (addr[4]<<8)| addr[5], (addr[6]<<8)| addr[7], - (addr[8]<<8)| addr[9], (addr[10]<<8)| addr[11], - (addr[12]<<8)| addr[13], (addr[14]<<8)| addr[15] ); + + tvb_memcpy(tvb, (guint8 *)&ipv6_addr, curr_offset, 16); + proto_tree_add_text(tree, + tvb, curr_offset, 16, + "IPv6: %s", ip6_to_str(&ipv6_addr)); break; } case 0x0002: @@ -9739,19 +9745,13 @@ break; case 0x0003: { - guchar *addr; proto_tree_add_text(tree,tvb, curr_offset-3, 2, "Parameter: (%u) DNS Server Address" , prot ); proto_tree_add_text(tree,tvb, curr_offset-1, 1, "Length: 0x%02x (%u)", e_len , e_len); - addr = (guchar*)tvb_get_ptr(tvb, curr_offset, 16); - - proto_tree_add_text(tree, - tvb, curr_offset, 16, - "IPv6: %4x:%4x:%4x:%4x:%4x:%4x:%4x:%4x", - (addr[0]<<8)| addr[1], (addr[2]<<8)| addr[3], - (addr[4]<<8)| addr[5], (addr[6]<<8)| addr[7], - (addr[8]<<8)| addr[9], (addr[10]<<8)| addr[11], - (addr[12]<<8)| addr[13], (addr[14]<<8)| addr[15] ); + tvb_memcpy(tvb, (guint8 *)&ipv6_addr, curr_offset, 16); + proto_tree_add_text(tree, + tvb, curr_offset, 16, + "IPv6: %s", ip6_to_str(&ipv6_addr)); break; } case 0x0004: @@ -9760,54 +9760,29 @@ oct = tvb_get_guint8(tvb, curr_offset); proto_tree_add_text(tree,tvb, curr_offset, 1, "Reject Code: 0x%02x (%u)", e_len , e_len); break; - case 0xC021: - proto_tree_add_text(tree,tvb, curr_offset-3, 2, "Protocol: (%u) LCP" , prot ); - proto_tree_add_text(tree,tvb, curr_offset-1, 1, "Length: 0x%02x (%u)", e_len , e_len); - /* - * dissect the embedded LCP message - */ - l3_tvb = tvb_new_subset(tvb, curr_offset, e_len, e_len); - if (!dissector_try_port(gprs_sm_pco_subdissector_table, prot, l3_tvb, &pco_pinfo, tree)) - call_dissector(data_handle, l3_tvb, &pco_pinfo, tree); - break; - case 0xC023: - proto_tree_add_text(tree,tvb, curr_offset-3, 2, "Protocol: (%u) PAP" , prot ); - proto_tree_add_text(tree,tvb, curr_offset-1, 1, "Length: 0x%02x (%u)", e_len , e_len); - /* - * dissect the embedded PAP message - */ - l3_tvb = tvb_new_subset(tvb, curr_offset, e_len, e_len); - if (!dissector_try_port(gprs_sm_pco_subdissector_table, prot, l3_tvb, &pco_pinfo, tree)) - call_dissector(data_handle, l3_tvb, &pco_pinfo, tree); - break; - case 0xC223: - proto_tree_add_text(tree,tvb, curr_offset-3, 2, "Protocol: (%u) CHAP" , prot ); - proto_tree_add_text(tree,tvb, curr_offset-1, 1, "Length: 0x%02x (%u)", e_len , e_len); - /* - * dissect the embedded CHAP message - */ - l3_tvb = tvb_new_subset(tvb, curr_offset, e_len, e_len); - if (!dissector_try_port(gprs_sm_pco_subdissector_table, prot, l3_tvb, &pco_pinfo, tree)) - call_dissector(data_handle, l3_tvb, &pco_pinfo, tree); - break; - case 0x8021: - proto_tree_add_text(tree,tvb, curr_offset-3, 2, "Protocol: (%u) IPCP" , prot ); - proto_tree_add_text(tree,tvb, curr_offset-1, 1, "Length: 0x%02x (%u)", e_len , e_len); - /* - * dissect the embedded IPCP message - */ - l3_tvb = tvb_new_subset(tvb, curr_offset, e_len, e_len); - if (!dissector_try_port(gprs_sm_pco_subdissector_table, prot, l3_tvb, &pco_pinfo, tree)) - call_dissector(data_handle, l3_tvb, &pco_pinfo, tree); - break; - default: - proto_tree_add_text(tree,tvb, curr_offset-3, 2, "Protocol/Parameter: (%u) unknwown" , prot ); - proto_tree_add_text(tree,tvb, curr_offset-1, 1, "Length: 0x%02x (%u)", e_len , e_len); - /* - * dissect the embedded DATA message - */ - l3_tvb = tvb_new_subset(tvb, curr_offset, e_len, e_len); - call_dissector(data_handle, l3_tvb, &pco_pinfo, tree); + default: + handle = dissector_get_port_handle ( gprs_sm_pco_subdissector_table , prot ); + if ( handle != NULL ) + { + proto_tree_add_text(tree,tvb, curr_offset-3, 2, "Protocol: (%u) %s" , + prot , val_to_str(prot, ppp_vals, "Unknown")); + proto_tree_add_text(tree,tvb, curr_offset-1, 1, "Length: 0x%02x (%u)", e_len , e_len); + /* + * dissect the embedded message + */ + l3_tvb = tvb_new_subset(tvb, curr_offset, e_len, e_len); + call_dissector(handle, l3_tvb , &p_info , tree ); + } + else + { + proto_tree_add_text(tree,tvb, curr_offset-3, 2, "Protocol/Parameter: (%u) unknwown" , prot ); + proto_tree_add_text(tree,tvb, curr_offset-1, 1, "Length: 0x%02x (%u)", e_len , e_len); + /* + * dissect the embedded DATA message + */ + l3_tvb = tvb_new_subset(tvb, curr_offset, e_len, e_len); + call_dissector(data_handle, l3_tvb, &p_info , tree); + } } curr_len-= e_len; @@ -9946,7 +9921,7 @@ tvb, curr_offset+2, 0, "IPv6: length is wrong"); } else { - tvb_memcpy(tvb, (guint8 *)&ipv6_addr, offset+2, 16); + tvb_memcpy(tvb, (guint8 *)&ipv6_addr, curr_offset+2, 16); proto_tree_add_text(tree, tvb, curr_offset+2, len-2, "IPv6: %s", ip6_to_str(&ipv6_addr)); @@ -10523,7 +10498,7 @@ } /* - * [7] 10.5.6.6 + * [8] 10.5.6.6 */ static guint8 de_sm_cause(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len, gchar *add_string) @@ -10541,6 +10516,7 @@ switch ( oct ) { case 0x08: str="Operator Determined Barring"; break; + case 0x18: str="MBMS bearer capabilities insufficient for the service"; break; case 0x19: str="LLC or SNDCP failure(GSM only)"; break; case 0x1a: str="Insufficient resources"; break; case 0x1b: str="Missing or unknown APN"; break; @@ -10561,6 +10537,7 @@ case 0x2a: str="Syntactical error in the TFT operation"; break; case 0x2b: str="Unknown PDP context"; break; case 0x2e: str="PDP context without TFT already activated"; break; + case 0x2f: str="Multicast group membership time-out"; break; case 0x2c: str="Semantic errors in packet filter(s)"; break; case 0x2d: str="Syntactical errors in packet filter(s)"; break; case 0x51: str="Invalid transaction identifier value"; break; @@ -10572,6 +10549,7 @@ case 0x64: str="Conditional IE error"; break; case 0x65: str="Message not compatible with the protocol state"; break; case 0x6f: str="Protocol error, unspecified"; break; + case 0x70: str="APN restriction value incompatible with active PDP context"; break; default: str="Protocol error, unspecified"; break; } @@ -10861,24 +10839,19 @@ if (( pf_identifier == 0x10 ) && ( pf_length == 4 )) { - pchar = (guchar*)tvb_get_ptr(tvb, offset, pf_length); - - proto_tree_add_text(tf_tree, - tvb, curr_offset, pf_length , - "Packet filter content: IPv4 %u.%u.%u.%u", - pchar[0], pchar[1], pchar[2], pchar[3] ); + proto_tree_add_text(tree, + tvb, curr_offset, pf_length, + "Packet filter content: IPv4 %s", ip_to_str(tvb_get_ptr(tvb, offset, 4))); } else if (( pf_identifier == 0x20 ) && ( pf_length == 16 )) { - pchar = (guchar*)tvb_get_ptr(tvb, offset, pf_length); - - proto_tree_add_text(tf_tree, - tvb, curr_offset, pf_length , - "Packet filter content: IPv6 %4x:%4x:%4x:%4x:%4x:%4x:%4x:%4x", - (pchar[0]<<8)| pchar[1], (pchar[2]<<8)| pchar[3], - (pchar[4]<<8)| pchar[5], (pchar[6]<<8)| pchar[7], - (pchar[8]<<8)| pchar[9], (pchar[10]<<8)| pchar[11], - (pchar[12]<<8)| pchar[13], (pchar[14]<<8)| pchar[15] ); + struct e_in6_addr ipv6_addr; + + tvb_memcpy(tvb, (guint8 *)&ipv6_addr, curr_offset, 16); + proto_tree_add_text(tree, + tvb, curr_offset+2, len-2, + "Packet filter content: IPv6 %s", ip6_to_str(&ipv6_addr)); + } else if (( pf_identifier == 0x30 ) && ( pf_length == 1 )) { @@ -10891,7 +10864,7 @@ } else if (( pf_identifier == 0x40 ) && ( pf_length == 2 )) { - pchar = (guchar*)tvb_get_ptr(tvb, offset, pf_length); + pchar = (guchar*)tvb_get_ptr(tvb, curr_offset, pf_length); proto_tree_add_text(tf_tree, tvb, curr_offset, pf_length , @@ -10900,7 +10873,7 @@ } else if (( pf_identifier == 0x50 ) && ( pf_length == 2 )) { - pchar = (guchar*)tvb_get_ptr(tvb, offset, pf_length); + pchar = (guchar*)tvb_get_ptr(tvb, curr_offset, pf_length); proto_tree_add_text(tf_tree, tvb, curr_offset, pf_length , @@ -10909,7 +10882,7 @@ } else if (( pf_identifier == 0x41 ) && ( pf_length == 4 )) { - pchar = (guchar*)tvb_get_ptr(tvb, offset, pf_length); + pchar = (guchar*)tvb_get_ptr(tvb, curr_offset, pf_length); proto_tree_add_text(tf_tree, tvb, curr_offset, pf_length , @@ -10918,7 +10891,7 @@ } else if (( pf_identifier == 0x51 ) && ( pf_length == 4 )) { - pchar = (guchar*)tvb_get_ptr(tvb, offset, pf_length); + pchar = (guchar*)tvb_get_ptr(tvb, curr_offset, pf_length); proto_tree_add_text(tf_tree, tvb, curr_offset, pf_length , @@ -10953,7 +10926,7 @@ } else if (( pf_identifier == 0x60 ) && ( pf_length == 4 )) { - pchar = (guchar*)tvb_get_ptr(tvb, offset, pf_length); + pchar = (guchar*)tvb_get_ptr(tvb, curr_offset, pf_length); proto_tree_add_text(tf_tree, tvb, curr_offset, pf_length , @@ -11023,7 +10996,7 @@ if (( p_identifier == 0x01 ) && ( p_length == 4 )) { - pchar = (guchar*)tvb_get_ptr(tvb, offset, p_length); + pchar = (guchar*)tvb_get_ptr(tvb, curr_offset, p_length); proto_tree_add_text(tf_tree, tvb, curr_offset, p_length , --- epan/dissectors/packet-gprs-llc.c (revision 13182) +++ epan/dissectors/packet-gprs-llc.c (working copy) @@ -171,6 +171,53 @@ { 0x3,"SACK" }, { 0, NULL }, }; + +/* CRC24 table - FCS */ +guint32 tbl_crc24[256] = { + 0x00000000, 0x00d6a776, 0x00f64557, 0x0020e221, 0x00b78115, 0x00612663, 0x0041c442, 0x00976334, + 0x00340991, 0x00e2aee7, 0x00c24cc6, 0x0014ebb0, 0x00838884, 0x00552ff2, 0x0075cdd3, 0x00a36aa5, + 0x00681322, 0x00beb454, 0x009e5675, 0x0048f103, 0x00df9237, 0x00093541, 0x0029d760, 0x00ff7016, + 0x005c1ab3, 0x008abdc5, 0x00aa5fe4, 0x007cf892, 0x00eb9ba6, 0x003d3cd0, 0x001ddef1, 0x00cb7987, + 0x00d02644, 0x00068132, 0x00266313, 0x00f0c465, 0x0067a751, 0x00b10027, 0x0091e206, 0x00474570, + 0x00e42fd5, 0x003288a3, 0x00126a82, 0x00c4cdf4, 0x0053aec0, 0x008509b6, 0x00a5eb97, 0x00734ce1, + 0x00b83566, 0x006e9210, 0x004e7031, 0x0098d747, 0x000fb473, 0x00d91305, 0x00f9f124, 0x002f5652, + 0x008c3cf7, 0x005a9b81, 0x007a79a0, 0x00acded6, 0x003bbde2, 0x00ed1a94, 0x00cdf8b5, 0x001b5fc3, + 0x00fb4733, 0x002de045, 0x000d0264, 0x00dba512, 0x004cc626, 0x009a6150, 0x00ba8371, 0x006c2407, + 0x00cf4ea2, 0x0019e9d4, 0x00390bf5, 0x00efac83, 0x0078cfb7, 0x00ae68c1, 0x008e8ae0, 0x00582d96, + 0x00935411, 0x0045f367, 0x00651146, 0x00b3b630, 0x0024d504, 0x00f27272, 0x00d29053, 0x00043725, + 0x00a75d80, 0x0071faf6, 0x005118d7, 0x0087bfa1, 0x0010dc95, 0x00c67be3, 0x00e699c2, 0x00303eb4, + 0x002b6177, 0x00fdc601, 0x00dd2420, 0x000b8356, 0x009ce062, 0x004a4714, 0x006aa535, 0x00bc0243, + 0x001f68e6, 0x00c9cf90, 0x00e92db1, 0x003f8ac7, 0x00a8e9f3, 0x007e4e85, 0x005eaca4, 0x00880bd2, + 0x00437255, 0x0095d523, 0x00b53702, 0x00639074, 0x00f4f340, 0x00225436, 0x0002b617, 0x00d41161, + 0x00777bc4, 0x00a1dcb2, 0x00813e93, 0x005799e5, 0x00c0fad1, 0x00165da7, 0x0036bf86, 0x00e018f0, + 0x00ad85dd, 0x007b22ab, 0x005bc08a, 0x008d67fc, 0x001a04c8, 0x00cca3be, 0x00ec419f, 0x003ae6e9, + 0x00998c4c, 0x004f2b3a, 0x006fc91b, 0x00b96e6d, 0x002e0d59, 0x00f8aa2f, 0x00d8480e, 0x000eef78, + 0x00c596ff, 0x00133189, 0x0033d3a8, 0x00e574de, 0x007217ea, 0x00a4b09c, 0x008452bd, 0x0052f5cb, + 0x00f19f6e, 0x00273818, 0x0007da39, 0x00d17d4f, 0x00461e7b, 0x0090b90d, 0x00b05b2c, 0x0066fc5a, + 0x007da399, 0x00ab04ef, 0x008be6ce, 0x005d41b8, 0x00ca228c, 0x001c85fa, 0x003c67db, 0x00eac0ad, + 0x0049aa08, 0x009f0d7e, 0x00bfef5f, 0x00694829, 0x00fe2b1d, 0x00288c6b, 0x00086e4a, 0x00dec93c, + 0x0015b0bb, 0x00c317cd, 0x00e3f5ec, 0x0035529a, 0x00a231ae, 0x007496d8, 0x005474f9, 0x0082d38f, + 0x0021b92a, 0x00f71e5c, 0x00d7fc7d, 0x00015b0b, 0x0096383f, 0x00409f49, 0x00607d68, 0x00b6da1e, + 0x0056c2ee, 0x00806598, 0x00a087b9, 0x007620cf, 0x00e143fb, 0x0037e48d, 0x001706ac, 0x00c1a1da, + 0x0062cb7f, 0x00b46c09, 0x00948e28, 0x0042295e, 0x00d54a6a, 0x0003ed1c, 0x00230f3d, 0x00f5a84b, + 0x003ed1cc, 0x00e876ba, 0x00c8949b, 0x001e33ed, 0x008950d9, 0x005ff7af, 0x007f158e, 0x00a9b2f8, + 0x000ad85d, 0x00dc7f2b, 0x00fc9d0a, 0x002a3a7c, 0x00bd5948, 0x006bfe3e, 0x004b1c1f, 0x009dbb69, + 0x0086e4aa, 0x005043dc, 0x0070a1fd, 0x00a6068b, 0x003165bf, 0x00e7c2c9, 0x00c720e8, 0x0011879e, + 0x00b2ed3b, 0x00644a4d, 0x0044a86c, 0x00920f1a, 0x00056c2e, 0x00d3cb58, 0x00f32979, 0x00258e0f, + 0x00eef788, 0x003850fe, 0x0018b2df, 0x00ce15a9, 0x0059769d, 0x008fd1eb, 0x00af33ca, 0x007994bc, + 0x00dafe19, 0x000c596f, 0x002cbb4e, 0x00fa1c38, 0x006d7f0c, 0x00bbd87a, 0x009b3a5b, 0x004d9d2d +}; + +#define GOOD_CRC24 0x0c91b6 +#define INIT_CRC24 0xffffff + +guint32 crc_calc(guint32 fcs, guchar *cp, int len) +{ + while (len--) + fcs = (fcs >> 8) ^ tbl_crc24[(fcs ^ *cp++) & 0xff]; + return fcs; +} + /* Code to actually dissect the packets */ static void dissect_llcgprs(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) @@ -180,6 +227,8 @@ proto_item *ti, *addres_field_item, *ctrl_field_item, *ui_ti; proto_tree *llcgprs_tree=NULL , *ad_f_tree =NULL, *ctrl_f_tree=NULL, *ui_tree=NULL; tvbuff_t *next_tvb; + guint32 fcs , fcs_calc; + guchar *data; /* Make entries in Protocol column and Info column on summary display */ if (check_col(pinfo->cinfo, COL_PROTOCOL)) col_set_str(pinfo->cinfo, COL_PROTOCOL, "GPRS-LLC"); @@ -196,7 +245,15 @@ if (check_col(pinfo->cinfo, COL_INFO)) col_add_fstr(pinfo->cinfo, COL_INFO, "SAPI: %s", match_strval(sapi,sapi_abrv)); - + + data = (guchar*)tvb_get_ptr(tvb, 0, crc_start+3 ); + fcs_calc = crc_calc ( INIT_CRC24 , data , crc_start ); + fcs_calc = ~fcs_calc; + + if ( memcmp ( &fcs_calc , data+crc_start , 3 ) == 0 ) + fcs = GOOD_CRC24; + else + fcs = ~GOOD_CRC24; /* In the interest of speed, if "tree" is NULL, don't do any work not necessary to generate protocol tree items. */ @@ -207,7 +264,11 @@ llcgprs_tree = proto_item_add_subtree(ti, ett_llcgprs); /* add an item to the subtree, see section 1.6 for more information */ - proto_tree_add_text( llcgprs_tree, tvb, crc_start,3, "CRC of LLC layer" ); + if ( fcs == GOOD_CRC24 ) + proto_tree_add_text ( llcgprs_tree , tvb , crc_start , 3 , "FCS: 0x%06x (correct)" , fcs_calc&0xffffff ); + else + proto_tree_add_text ( llcgprs_tree , tvb , crc_start , 3 , "FCS: 0x%02x%02x%02x (incorrect, should be 0x%06x)", + data[crc_start] , data[crc_start+1], data[crc_start+2], fcs_calc & 0xffffff ); addres_field_item = proto_tree_add_uint_format(llcgprs_tree,hf_llcgprs_sapi, tvb, 0,1, sapi, "Address field SAPI: %s", match_strval(sapi,sapi_abrv)); ad_f_tree = proto_item_add_subtree(addres_field_item, ett_llcgprs_adf); @@ -216,6 +277,8 @@ proto_tree_add_uint(ad_f_tree, hf_llcgprs_sapib, tvb, 0, 1, addr_fld ); } + + ctrl_fld_fb = tvb_get_guint8(tvb,offset); if ( ctrl_fld_fb < 0xc0 ){ frame_format = ( ctrl_fld_fb < 0x80)? I_FORMAT : S_FORMAT; @@ -267,12 +330,13 @@ proto_tree_add_boolean( ctrl_f_tree, hf_llcgprs_PM_bit, tvb, offset-2,2,ctrl_fld_ui_s); } + next_tvb = tvb_new_subset(tvb, offset,crc_start-3, -1 ); - if (ignore_cipher_bit || !(epm & 0x2)){ + if ((ignore_cipher_bit && (fcs == GOOD_CRC24)) || !(epm & 0x2)){ /* * Either we're ignoring the cipher bit * (because the bit is set but the - * data is unciphered), or the cipher + * data is unciphered), or the cipher * bit isn't set (indicating that the * data is unciphered). Try dissecting * it with a subdissector. @@ -383,9 +447,9 @@ register_dissector( "llcgprs", dissect_llcgprs, proto_llcgprs); llcgprs_module = prefs_register_protocol ( proto_llcgprs, NULL ); - prefs_register_bool_preference ( llcgprs_module, "ignore_cipher_bit", - "Ignore cipher bit", - "Whether to ignore the cipher bit (because it might be set on unciphered data)", + prefs_register_bool_preference ( llcgprs_module, "autodetect_cipher_bit", + "autodetect cipher bit", + "Whether to autodetect the cipher bit (because it might be set on unciphered data)", &ignore_cipher_bit ); } --- epan/dissectors/packet-bssgp.c (revision 13182) +++ epan/dissectors/packet-bssgp.c (working copy) @@ -1177,12 +1177,11 @@ tvbuff_t *next_tvb; next_tvb = tvb_new_subset(bi->tvb, bi->offset, -1, -1); - call_dissector(handle, next_tvb, bi->pinfo, bi->parent_tree); if (bi->bssgp_tree) { bssgp_proto_tree_add_ie(ie, bi, ie_start_offset); } - if (!handle) { + if (handle) { call_dissector(handle, next_tvb, bi->pinfo, bi->parent_tree); } else if (data_handle) {
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