--- /dev/null
+From 8ab33ab3f2de22f83df1cd45ae9a38254dc76400 Mon Sep 17 00:00:00 2001
+From: Alex Badea <vamposdecampos@gmail.com>
+Date: Sun, 21 Nov 2010 22:19:58 +0200
+Subject: [RFC][PATCH wireshark] packet-lapdm: dissect CBS payloads
+
+Hack dissection of Cell Broadcast Service into LAPDm. First-Block payloads
+are also dissected directly.
+---
+ packet-lapdm.c | 164 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
+ 1 file changed, 163 insertions(+), 1 deletion(-)
+
+diff --git a/epan/dissectors/packet-lapdm.c b/epan/dissectors/packet-lapdm.c
+index dbeac85..e1d67b4 100644
+--- a/epan/dissectors/packet-lapdm.c
++++ b/epan/dissectors/packet-lapdm.c
+@@ -61,12 +61,25 @@
+ #include <epan/xdlc.h>
+ #include <epan/reassemble.h>
+
++#include <epan/asn1.h>
++#include "packet-gsm_map.h"
++#include "packet-gsm_sms.h"
++
+ static int proto_lapdm = -1;
+ static int hf_lapdm_address = -1;
+ static int hf_lapdm_ea = -1;
+ static int hf_lapdm_cr = -1;
+ static int hf_lapdm_sapi = -1;
+ static int hf_lapdm_lpd = -1;
++static int hf_lapdm_cb_lb = -1;
++static int hf_lapdm_cb_seq = -1;
++static int hf_lapdm_cbs_serial_gs = -1;
++static int hf_lapdm_cbs_serial_mcode = -1;
++static int hf_lapdm_cbs_serial_updnum = -1;
++static int hf_lapdm_cbs_msgid = -1;
++static int hf_lapdm_cbs_page_num = -1;
++static int hf_lapdm_cbs_page_cnt = -1;
++static int hf_lapdm_cbs_content = -1;
+
+ static int hf_lapdm_control = -1;
+ static int hf_lapdm_n_r = -1;
+@@ -103,6 +116,8 @@ static gint ett_lapdm_control = -1;
+ static gint ett_lapdm_length = -1;
+ static gint ett_lapdm_fragment = -1;
+ static gint ett_lapdm_fragments = -1;
++static gint ett_lapdm_cbs_serial = -1;
++static gint ett_lapdm_cbs_dcs = -1;
+
+ static GHashTable *lapdm_fragment_table = NULL;
+ static GHashTable *lapdm_reassembled_table = NULL;
+@@ -121,6 +136,12 @@ static gboolean reassemble_lapdm = TRUE;
+ #define LAPDM_CR 0x02 /* Command/Response bit */
+ #define LAPDM_EA 0x01 /* First Address Extension bit */
+ #define LAPDM_LPD 0x60 /* Link Protocol Discriminator */
++#define LAPDM_LPD_CB 0x20 /* Cell Broadcast LPD */
++#define LAPDM_CB_LB 0x10 /* Cell Broadcast Last Bit */
++#define LAPDM_CB_SEQ 0x0f /* Cell Broadcast sequence number */
++#define LAPDM_CBS_SERIAL_GS 0xc0 /* CBS Serial Number - Geographical Scope */
++#define LAPDM_CBS_SERIAL_MCODE 0x3ffc /* CBS Serial Number - Message Code */
++#define LAPDM_CBS_SERIAL_UPDNUM 0x03 /* CBS Serial Number - Update Number */
+
+ /*
+ * Bits in the length field.
+@@ -132,6 +153,7 @@ static gboolean reassemble_lapdm = TRUE;
+ #define LAPDM_LEN_SHIFT 2
+
+ #define LAPDM_HEADER_LEN 3
++#define LAPDM_CB_HEADER_LEN 1
+
+ #define LAPDM_SAPI_RR_CC_MM 0
+ #define LAPDM_SAPI_SMS 3
+@@ -179,6 +201,33 @@ static const value_string lapdm_el_vals[] = {
+ { 0, NULL }
+ };
+
++/* 04.12 section 3.3.1 */
++static const value_string lapdm_lb_vals[] = {
++ { 0, "More blocks" },
++ { 1, "Last block" },
++ { 0, NULL }
++};
++
++/* 04.12 section 3.3.1 */
++static const value_string lapdm_seq_vals[] = {
++ { 0, "First block" },
++ { 1, "Second block" },
++ { 2, "Third block" },
++ { 3, "Fourth block" },
++ { 8, "First schedule block" },
++ { 15, "Null message" },
++ { 0, NULL }
++};
++
++/* 03.41 section 9.3.2.1 */
++static const value_string lapdm_serial_gs_vals[] = {
++ { 0, "Cell wide (immediate)" },
++ { 1, "PLMN wide" },
++ { 2, "Location Area wide" },
++ { 3, "Cell wide" },
++ { 0, NULL }
++};
++
+
+ static const fragment_items lapdm_frag_items = {
+ /* Fragment subtrees */
+@@ -209,6 +258,79 @@ lapdm_defragment_init (void)
+
+
+ static void
++dissect_lapdm_cb(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
++{
++ proto_tree *lapdm_tree, *addr_tree;
++ proto_item *lapdm_ti, *addr_ti;
++ guint8 addr, seq;
++ tvbuff_t *payload;
++ int offset;
++ int length, out_len;
++ gchar msgbuf[88];
++
++ addr = tvb_get_guint8(tvb, 0);
++ if (tree) {
++ lapdm_ti = proto_tree_add_item(tree, proto_lapdm, tvb, 0, LAPDM_CB_HEADER_LEN, FALSE);
++ lapdm_tree = proto_item_add_subtree(lapdm_ti, ett_lapdm);
++
++ addr_ti = proto_tree_add_uint(lapdm_tree, hf_lapdm_address, tvb, 0, 1, addr);
++ addr_tree = proto_item_add_subtree(addr_ti, ett_lapdm_address);
++
++ proto_tree_add_uint(addr_tree, hf_lapdm_lpd, tvb, 0, 1, addr);
++ proto_tree_add_uint(addr_tree, hf_lapdm_cb_lb, tvb, 0, 1, addr);
++ proto_tree_add_uint(addr_tree, hf_lapdm_cb_seq, tvb, 0, 1, addr);
++ } else {
++ lapdm_ti = NULL;
++ lapdm_tree = NULL;
++ }
++
++ col_append_str(pinfo->cinfo, COL_INFO, "CBS ");
++
++ offset = 1;
++
++ /* TODO: reassemble blocks 1-3 */
++ seq = addr & LAPDM_CB_SEQ;
++ if (seq == 0) {
++ proto_item *ti;
++ proto_tree *subtree;
++
++ ti = proto_tree_add_text(lapdm_tree, tvb, offset, 2, "Serial Number");
++ subtree = proto_item_add_subtree(ti, ett_lapdm_cbs_serial);
++
++ proto_tree_add_item(subtree, hf_lapdm_cbs_serial_gs, tvb, offset, 1, FALSE);
++ proto_tree_add_item(subtree, hf_lapdm_cbs_serial_mcode, tvb, offset, 2, FALSE);
++ offset++;
++ proto_tree_add_item(subtree, hf_lapdm_cbs_serial_updnum, tvb, offset, 1, FALSE);
++ offset++;
++
++ proto_tree_add_item(lapdm_tree, hf_lapdm_cbs_msgid, tvb, offset, 2, FALSE);
++ offset += 2;
++
++ ti = proto_tree_add_text(lapdm_tree, tvb, offset, 1, "Data Coding Scheme");
++ subtree = proto_item_add_subtree(ti, ett_lapdm_cbs_dcs);
++ dissect_cbs_data_coding_scheme(tvb_new_subset(tvb, offset, 1, -1), pinfo, subtree);
++ offset++;
++
++ proto_tree_add_item(lapdm_tree, hf_lapdm_cbs_page_num, tvb, offset, 1, FALSE);
++ proto_tree_add_item(lapdm_tree, hf_lapdm_cbs_page_cnt, tvb, offset, 1, FALSE);
++ offset++;
++
++ length = tvb_length(tvb) - offset;
++ out_len = gsm_sms_char_7bit_unpack(0, length, sizeof(msgbuf) - 1,
++ tvb_get_ptr(tvb, offset, length), msgbuf);
++ msgbuf[out_len] = '\0';
++ proto_tree_add_string(lapdm_tree, hf_lapdm_cbs_content, tvb, offset, length,
++ gsm_sms_chars_to_utf8(msgbuf, out_len));
++
++ col_append_fstr(pinfo->cinfo, COL_INFO, " [%s]", gsm_sms_chars_to_utf8(msgbuf, out_len));
++ }
++
++ payload = tvb_new_subset_remaining(tvb, offset);
++ call_dissector(data_handle, payload, pinfo, tree);
++}
++
++
++static void
+ dissect_lapdm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+ {
+ proto_tree *lapdm_tree, *addr_tree, *length_tree;
+@@ -227,6 +349,11 @@ dissect_lapdm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+ col_set_str(pinfo->cinfo, COL_PROTOCOL, "LAPDm");
+
+ addr = tvb_get_guint8(tvb, 0);
++ if ((addr & LAPDM_LPD) == LAPDM_LPD_CB) {
++ dissect_lapdm_cb(tvb, pinfo, tree);
++ return;
++ }
++
+ length = tvb_get_guint8(tvb, 2);
+
+ cr = addr & LAPDM_CR;
+@@ -360,6 +487,39 @@ proto_register_lapdm(void)
+ { "SAPI", "lapdm.sapi", FT_UINT8, BASE_DEC, VALS(lapdm_sapi_vals), LAPDM_SAPI,
+ "Service access point identifier", HFILL }},
+
++ { &hf_lapdm_cb_lb,
++ { "LB", "lapdm.cb.lb", FT_UINT8, BASE_DEC,
++ VALS(lapdm_lb_vals), LAPDM_CB_LB, "Last Block bit", HFILL }},
++
++ { &hf_lapdm_cb_seq,
++ { "SEQ", "lapdm.cb.seq", FT_UINT8, BASE_DEC,
++ VALS(lapdm_seq_vals), LAPDM_CB_SEQ, "Sequence Number", HFILL }},
++
++ { &hf_lapdm_cbs_serial_gs,
++ { "GS", "lapdm.cbs.serial.gs", FT_UINT8, BASE_DEC,
++ VALS(lapdm_serial_gs_vals), LAPDM_CBS_SERIAL_GS, "Geographic Scope", HFILL }},
++ { &hf_lapdm_cbs_serial_mcode,
++ { "Message Code", "lapdm.cbs.serial.mcode", FT_UINT16, BASE_DEC,
++ NULL, LAPDM_CBS_SERIAL_MCODE, NULL, HFILL }},
++ { &hf_lapdm_cbs_serial_updnum,
++ { "Update Number", "lapdm.cbs.serial.updnum", FT_UINT8, BASE_DEC,
++ NULL, LAPDM_CBS_SERIAL_MCODE, NULL, HFILL }},
++
++ { &hf_lapdm_cbs_msgid,
++ { "Message Identifier", "lapdm.cbs.msgid", FT_UINT16, BASE_DEC,
++ NULL, 0, NULL, HFILL }},
++
++ { &hf_lapdm_cbs_page_num,
++ { "Page number", "lapdm.cbs.page.num", FT_UINT8, BASE_DEC,
++ NULL, 0xf0, NULL, HFILL }},
++ { &hf_lapdm_cbs_page_cnt,
++ { "Total pages", "lapdm.cbs.page.cnt", FT_UINT8, BASE_DEC,
++ NULL, 0x0f, NULL, HFILL }},
++
++ { &hf_lapdm_cbs_content,
++ { "Content of Message", "lapdm.cbs.content", FT_STRING, BASE_NONE,
++ NULL, 0x00, NULL, HFILL }},
++
+ { &hf_lapdm_control,
+ { "Control Field", "lapdm.control_field", FT_UINT8, BASE_HEX, NULL, 0x0,
+ NULL, HFILL }},
+@@ -461,7 +621,9 @@ proto_register_lapdm(void)
+ &ett_lapdm_control,
+ &ett_lapdm_length,
+ &ett_lapdm_fragment,
+- &ett_lapdm_fragments
++ &ett_lapdm_fragments,
++ &ett_lapdm_cbs_serial,
++ &ett_lapdm_cbs_dcs,
+ };
+
+ module_t *lapdm_module;
projects / osmocom-bb.git / commitdiff