UMTS Iub: Resolve U-RNTI for C-RNTI

This commit includes logic used to store pairs of C-RNTIs and U-RNTIs based on allocations in RRC and logic to retrive those when encountering C-RNTIs in the MAC header for DCCH over FACH/RACH.

Change-Id: I629ab061b7a73416e5730a980480b81a1aaade11
Reviewed-on: https://code.wireshark.org/review/21607
Petri-Dish: Anders Broman <a.broman58@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

4 files changed, 136 insertions, 22 deletions

diff --git a/epan/dissectors/asn1/nbap/nbap.cnf b/epan/dissectors/asn1/nbap/nbap.cnf
index 2bcdcc6f21..30bf5b8785 100644
--- a/epan/dissectors/asn1/nbap/nbap.cnf
+++ b/epan/dissectors/asn1/nbap/nbap.cnf
@@ -748,6 +748,7 @@ hsdsch_macdflow_ids[num_items-1] = hsdsch_macdflow_id;
 #.FN_BODY RACH-ParametersItem-CTCH-SetupRqstFDD
 address     dst_addr, null_addr;
 conversation_t *conversation;
+fp_rach_channel_info_t* fp_rach_channel_info;
 umts_fp_conversation_info_t *umts_fp_conversation_info;
 int j, num_tf;
 
@@ -789,6 +790,12 @@ transportFormatSet_type = NBAP_CPCH;
                 umts_fp_conversation_info->crnc_port         = BindingID_port;
                 umts_fp_conversation_info->rlc_mode          = FP_RLC_MODE_UNKNOWN;
 
+                /* Adding the 'channel specific info' for RACH */
+                fp_rach_channel_info = wmem_new0(wmem_file_scope(), fp_rach_channel_info_t);
+                fp_rach_channel_info->crnti_to_urnti_map = wmem_tree_new_autoreset(wmem_epan_scope(), wmem_file_scope());
+                umts_fp_conversation_info->channel_specific_info = (void*)fp_rach_channel_info;
+
+
                 /*Save unique UE-identifier */
                 umts_fp_conversation_info->com_context_id = crcn_context_present ?  com_context_id : 1;
 
@@ -949,6 +956,7 @@ num_items = 1;
 address     dst_addr, null_addr;
 conversation_t *conversation;
 
+fp_fach_channel_info_t* fp_fach_channel_info;
 umts_fp_conversation_info_t *umts_fp_conversation_info;
 int i, j, num_tf;
 
@@ -993,6 +1001,10 @@ transportFormatSet_type = NBAP_CPCH;
                 /*Save unique UE-identifier */
                 umts_fp_conversation_info->com_context_id = crcn_context_present ? com_context_id : 1;
 
+                /* Adding the 'channel specific info' for FACH */
+                fp_fach_channel_info = wmem_new0(wmem_file_scope(), fp_fach_channel_info_t);
+                fp_fach_channel_info->crnti_to_urnti_map = wmem_tree_new_autoreset(wmem_epan_scope(), wmem_file_scope());
+                umts_fp_conversation_info->channel_specific_info = (void*)fp_fach_channel_info;
 
                 /* DCH's in this flow */
                 umts_fp_conversation_info->dch_crc_present = g_nbap_msg_info_for_fp.dch_crc_present;
diff --git a/epan/dissectors/asn1/rrc/packet-rrc-template.c b/epan/dissectors/asn1/rrc/packet-rrc-template.c
index 2af4f2b1a3..1b24415209 100644
--- a/epan/dissectors/asn1/rrc/packet-rrc-template.c
+++ b/epan/dissectors/asn1/rrc/packet-rrc-template.c
@@ -45,6 +45,8 @@
 #include "packet-gsm_a_common.h"
 #include "packet-nbap.h"
 #include "packet-umts_fp.h"
+#include "packet-umts_mac.h"
+#include "packet-rlc.h"
 
 #ifdef _MSC_VER
 /* disable: "warning C4049: compiler limit : terminating line number emission" */
@@ -57,10 +59,14 @@
 #define PSNAME "RRC"
 #define PFNAME "rrc"
 
-extern int proto_fp;    /*Handler to FP*/
+extern int proto_fp;       /*Handler to FP*/
+extern int proto_umts_mac; /*Handler to MAC*/
+extern int proto_rlc;      /*Handler to RLC*/
 
 GTree * hsdsch_muxed_flows = NULL;
 GTree * rrc_ciph_inf = NULL;
+GTree * rrc_scrambling_code_urnti = NULL;
+wmem_tree_t* rrc_rach_urnti_crnti_map = NULL;
 static int msg_type _U_;
 
 /*****************************************************************************/
@@ -81,6 +87,7 @@ typedef struct umts_rrc_private_data_t
   guint32 s_rnc_id; /* The S-RNC ID part of a U-RNTI */
   guint32 s_rnti; /* The S-RNTI part of a U-RNTI */
   guint32 new_u_rnti;
+  guint32 current_u_rnti;
   guint32 scrambling_code;
   enum nas_sys_info_gsm_map cn_domain;
 } umts_rrc_private_data_t;
@@ -101,62 +108,74 @@ static umts_rrc_private_data_t* umts_rrc_get_private_data(asn1_ctx_t *actx)
 
 static guint32 private_data_get_s_rnc_id(asn1_ctx_t *actx)
 {
-  umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
-  return private_data->s_rnc_id;
+    umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+    return private_data->s_rnc_id;
 }
 
 static void private_data_set_s_rnc_id(asn1_ctx_t *actx, guint32 s_rnc_id)
 {
-  umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
-  private_data->s_rnc_id = s_rnc_id;
+    umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+    private_data->s_rnc_id = s_rnc_id;
 }
 
 static guint32 private_data_get_s_rnti(asn1_ctx_t *actx)
 {
-  umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
-  return private_data->s_rnti;
+    umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+    return private_data->s_rnti;
 }
 
 static void private_data_set_s_rnti(asn1_ctx_t *actx, guint32 s_rnti)
 {
-  umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
-  private_data->s_rnti = s_rnti;
+    umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+    private_data->s_rnti = s_rnti;
 }
 
 static guint32 private_data_get_new_u_rnti(asn1_ctx_t *actx)
 {
-  umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
-  return private_data->new_u_rnti;
+    umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+    return private_data->new_u_rnti;
 }
 
 static void private_data_set_new_u_rnti(asn1_ctx_t *actx, guint32 new_u_rnti)
 {
-  umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
-  private_data->new_u_rnti = new_u_rnti;
+    umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+    private_data->new_u_rnti = new_u_rnti;
+}
+
+static guint32 private_data_get_current_u_rnti(asn1_ctx_t *actx)
+{
+    umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+    return private_data->current_u_rnti;
+}
+
+static void private_data_set_current_u_rnti(asn1_ctx_t *actx, guint32 current_u_rnti)
+{
+    umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+    private_data->current_u_rnti = current_u_rnti;
 }
 
 static guint32 private_data_get_scrambling_code(asn1_ctx_t *actx)
 {
-  umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
-  return private_data->scrambling_code;
+    umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+    return private_data->scrambling_code;
 }
 
 static void private_data_set_scrambling_code(asn1_ctx_t *actx, guint32 scrambling_code)
 {
-  umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
-  private_data->scrambling_code = scrambling_code;
+    umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+    private_data->scrambling_code = scrambling_code;
 }
 
 static enum nas_sys_info_gsm_map private_data_get_cn_domain(asn1_ctx_t *actx)
 {
-  umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
-  return private_data->cn_domain;
+    umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+    return private_data->cn_domain;
 }
 
 static void private_data_set_cn_domain(asn1_ctx_t *actx, enum nas_sys_info_gsm_map cn_domain)
 {
-  umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
-  private_data->cn_domain = cn_domain;
+    umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+    private_data->cn_domain = cn_domain;
 }
 
 /*****************************************************************************/
@@ -351,6 +370,15 @@ rrc_init(void) {
                        NULL,      /* data pointer, optional */
                        NULL,
                        rrc_free_value);
+
+    /*Initialize Scrambling code to U-RNTI dictionary*/
+    rrc_scrambling_code_urnti = g_tree_new_full(rrc_key_cmp,
+                       NULL,
+                       NULL,
+                       NULL);
+
+    /* Global U-RNTI / C-RNTI map to be used in RACH channels */
+    rrc_rach_urnti_crnti_map = wmem_tree_new_autoreset(wmem_epan_scope(), wmem_file_scope());
 }
 
 static void
diff --git a/epan/dissectors/asn1/rrc/packet-rrc-template.h b/epan/dissectors/asn1/rrc/packet-rrc-template.h
index 6ae2b0661d..72efe6c20e 100644
--- a/epan/dissectors/asn1/rrc/packet-rrc-template.h
+++ b/epan/dissectors/asn1/rrc/packet-rrc-template.h
@@ -60,5 +60,7 @@ typedef struct rrc_ciph_info_
 
 extern GTree * hsdsch_muxed_flows;
 extern GTree * rrc_ciph_inf;
+extern GTree * rrc_scrambling_code_urnti;
+extern wmem_tree_t* rrc_rach_urnti_crnti_map;
 
 #endif  /* PACKET_RRC_H */
diff --git a/epan/dissectors/asn1/rrc/rrc.cnf b/epan/dissectors/asn1/rrc/rrc.cnf
index d444fcbbc8..1f471f7850 100644
--- a/epan/dissectors/asn1/rrc/rrc.cnf
+++ b/epan/dissectors/asn1/rrc/rrc.cnf
@@ -787,16 +787,88 @@ HNBName TYPE=FT_STRING DISPLAY=STR_UNICODE
   s_rnti = private_data_get_s_rnti(actx);
   if(s_rnc_id != 0 && s_rnti != 0) {
       u_rnti_value = (s_rnc_id << 20) | s_rnti;
-      /* We are looking for new allocated U-RNTIs, not previously used ones */
+      /* Distinguishing between new allocated U-RNTIs and previously used ones */
       if (is_new_urnti) {
           private_data_set_new_u_rnti(actx, u_rnti_value);
       }
+      else {
+          private_data_set_current_u_rnti(actx, u_rnti_value);
+      }
       /* Adding U-RNTI value to it's tree item */
       proto_item_append_text(actx->created_item,": %%08x", u_rnti_value);
   }
   private_data_set_s_rnc_id(actx, 0);
   private_data_set_s_rnti(actx, 0);
 
+#.FN_BODY C-RNTI VAL_PTR = &c_rnti_tvb
+  fp_info *fpinf = NULL;
+  umts_mac_info *macinf = NULL;
+  rlc_info *rlcinf = NULL;
+  conversation_t   *p_conv;
+  umts_fp_conversation_info_t *umts_fp_conversation_info = NULL;
+  fp_fach_channel_info_t *fp_fach_channel_info = NULL;
+  tvbuff_t * c_rnti_tvb = NULL;
+  guint16 c_rnti = 0;
+  guint32 u_rnti = 0;
+  fp_crnti_allocation_info_t *fp_crnti_allocation_info = NULL;
+%(DEFAULT_BODY)s
+  if (!c_rnti_tvb)
+    return offset;
+
+  if(tvb_reported_length(c_rnti_tvb)>=2){
+    c_rnti = tvb_get_ntohs(c_rnti_tvb,0);
+  }
+
+  if(actx->pinfo->fd->flags.visited) /* Frame was already checked*/
+    return offset;
+
+  /* Trying to figure where to get the U-RNTI from Either from an ASN.1 field (if this is CCCH) or RLC's attached info (if this is DCCH) */
+  fpinf = (fp_info *)p_get_proto_data(wmem_file_scope(), actx->pinfo, proto_fp, 0);
+  macinf = (umts_mac_info *)p_get_proto_data(wmem_file_scope(), actx->pinfo, proto_umts_mac, 0);
+  rlcinf = (rlc_info *)p_get_proto_data(wmem_file_scope(), actx->pinfo, proto_rlc, 0);
+  if (fpinf && macinf && rlcinf) {
+    switch(macinf->content[fpinf->cur_tb]){
+      case MAC_DCCH:
+        u_rnti = rlcinf->urnti[fpinf->cur_tb];
+        break;
+      case MAC_CCCH:
+      default:
+        u_rnti = private_data_get_current_u_rnti(actx);
+        break;
+    }
+  }
+  else {
+    /* Either FP, MAC or RLC info is missing - looking for ASN.1 field as last resort*/
+    u_rnti = private_data_get_current_u_rnti(actx);
+  }
+
+  if(u_rnti == 0 || c_rnti == 0) /* U-RNTI missing or failed to parse C-RNTI */
+    return offset;
+
+  /* Both U-RNTI and C-RNTI present - storing the match*/
+  fp_crnti_allocation_info = wmem_new0(wmem_file_scope(), fp_crnti_allocation_info_t);
+  fp_crnti_allocation_info->urnti = u_rnti;
+  fp_crnti_allocation_info->alloc_frame_number = actx->pinfo->num;
+
+  /* Finding FP conversation info */
+  p_conv = (conversation_t *)find_conversation(actx->pinfo->num, &actx->pinfo->net_dst, &actx->pinfo->net_src,
+      actx->pinfo->ptype,
+      actx->pinfo->destport, actx->pinfo->srcport, NO_ADDR_B);
+
+  /* If the current FP channel is FACH, Adding the C-RNTI / U-RNTI match to the FACH's RNTIs map*/
+  if (p_conv != NULL) {
+      umts_fp_conversation_info = (umts_fp_conversation_info_t *)conversation_get_proto_data(p_conv, proto_fp);
+      if (umts_fp_conversation_info && umts_fp_conversation_info->channel == CHANNEL_FACH_FDD) {
+          fp_fach_channel_info = (fp_fach_channel_info_t *)umts_fp_conversation_info->channel_specific_info;
+          if(fp_fach_channel_info) {
+              wmem_tree_insert32(fp_fach_channel_info->crnti_to_urnti_map, c_rnti, (void *)fp_crnti_allocation_info);
+          }
+      }
+  }
+
+  /* Also adding the C-RNTI / U-RNTI match to the global RNTIs map for the RACH channel */
+  wmem_tree_insert32(rrc_rach_urnti_crnti_map, c_rnti, (void *)fp_crnti_allocation_info);
+
 #.FN_BODY UL-ScramblingCode VAL_PTR = &scrambling_code
 guint32 scrambling_code;
 %(DEFAULT_BODY)s