Ethereal-dev: [Ethereal-dev] GMM/SM + LLC + BSSGP Patch
Note: This archive is from the project's previous web site, ethereal.com. This list is no longer active.
From: Pilz Rene <rene.pilz@xxxxxx>
Date: Fri, 28 Jan 2005 13:31:43 +0100
Hi 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 activated
GMM/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 Ren� Pilz ftw. Telekommunications Research Center Vienna http://www.ftw.at Tech Gate Vienna, Donaucitystra�e 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) {
- Prev by Date: [Ethereal-dev] usbsnoop (was: Getting signal from USB port)
- Next by Date: Re: [Ethereal-dev] Validating IPs?
- Previous by thread: [Ethereal-dev] usbsnoop (was: Getting signal from USB port)
- Next by thread: [Ethereal-dev] Colorization in Ethereal
- Index(es):