UMTS RLC: Mark ciphered frames

- Updated RRC dissector to always collect ciphering sequence numbers
from Security Mode Command/ Security Mode Complete
- Updated RLC dissector to seek the collected info when deciding if
the frame is ciphered

Change-Id: I44bc61736968ef9f420782048e15ba27d6c6267f
Reviewed-on: https://code.wireshark.org/review/23132
Petri-Dish: Pascal Quantin <pascal.quantin@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Pascal Quantin <pascal.quantin@gmail.com>

3 files changed, 168 insertions, 83 deletions

diff --git a/epan/dissectors/asn1/rrc/packet-rrc-template.c b/epan/dissectors/asn1/rrc/packet-rrc-template.c
index 82e6b67532..625741cca6 100644
--- a/epan/dissectors/asn1/rrc/packet-rrc-template.c
+++ b/epan/dissectors/asn1/rrc/packet-rrc-template.c
@@ -64,7 +64,7 @@ extern int proto_umts_mac; /*Handler to MAC*/
 extern int proto_umts_rlc; /*Handler to RLC*/
 
 GTree * hsdsch_muxed_flows = NULL;
-GTree * rrc_ciph_inf = NULL;
+GTree * rrc_ciph_info_tree = NULL;
 GTree * rrc_scrambling_code_urnti = NULL;
 wmem_tree_t* rrc_rach_urnti_crnti_map = NULL;
 static int msg_type _U_;
@@ -90,6 +90,9 @@ typedef struct umts_rrc_private_data_t
   guint32 current_u_rnti;
   guint32 scrambling_code;
   enum nas_sys_info_gsm_map cn_domain;
+  guint32 rbid;
+  guint32 rlc_ciphering_sqn; /* Sequence number where ciphering starts in a given bearer */
+  rrc_ciphering_info* ciphering_info;
 } umts_rrc_private_data_t;
 
 
@@ -108,74 +111,110 @@ 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;
+  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;
+  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;
+}
+
+static guint32 private_data_get_rbid(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->rbid;
+}
+
+static void private_data_set_rbid(asn1_ctx_t *actx, guint32 rbid)
+{
+  umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+  private_data->rbid = rbid;
+}
+
+static guint32 private_data_get_rlc_ciphering_sqn(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->rlc_ciphering_sqn;
+}
+
+static void private_data_set_rlc_ciphering_sqn(asn1_ctx_t *actx, guint32 rlc_ciphering_sqn)
+{
+  umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+  private_data->rlc_ciphering_sqn = rlc_ciphering_sqn;
+}
+
+static rrc_ciphering_info* private_data_get_ciphering_info(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->ciphering_info;
+}
+
+static void private_data_set_ciphering_info(asn1_ctx_t *actx, rrc_ciphering_info* ciphering_info)
+{
+  umts_rrc_private_data_t *private_data = (umts_rrc_private_data_t*)umts_rrc_get_private_data(actx);
+  private_data->ciphering_info = ciphering_info;
 }
 
 /*****************************************************************************/
@@ -265,9 +304,6 @@ static int flowd,type;
 /*Stores how many channels we have detected for a HS-DSCH MAC-flow*/
 #define    RRC_MAX_NUM_HSDHSCH_MACDFLOW 8
 static guint8 num_chans_per_flow[RRC_MAX_NUM_HSDHSCH_MACDFLOW];
-static int rbid;
-static int activation_frame;
-
 
 /**
  * Return the maximum counter, useful for initiating counters
@@ -276,14 +312,14 @@ static int activation_frame;
 static int get_max_counter(int com_context){
     int i;
     guint32 max = 0;
-    rrc_ciphering_info * c_inf;
+    rrc_ciphering_info * ciphering_info;
 
-    if( (c_inf = g_tree_lookup(rrc_ciph_inf, GINT_TO_POINTER((gint)com_context))) == NULL ){
+    if( (ciphering_info = g_tree_lookup(rrc_ciph_info_tree, GINT_TO_POINTER((gint)com_context))) == NULL ){
         return 0;
     }
     for(i = 0; i<31; i++){
-        max = MAX(c_inf->ps_conf_counters[i][0], max);
-        max = MAX(c_inf->ps_conf_counters[i][1], max);
+        max = MAX(ciphering_info->ps_conf_counters[i][0], max);
+        max = MAX(ciphering_info->ps_conf_counters[i][1], max);
     }
     return max;
 }
@@ -304,8 +340,35 @@ static void rrc_free_key(gpointer key _U_){
 static void rrc_free_value(gpointer value ){
             g_free(value);
 }
-#include "packet-rrc-fn.c"
 
+static rrc_ciphering_info*
+get_or_create_cipher_info(fp_info *fpinf, rlc_info *rlcinf) {
+  rrc_ciphering_info *cipher_info = NULL;
+  guint32 ueid;
+  int i;
+
+  ueid = rlcinf->ueid[fpinf->cur_tb];
+
+  cipher_info = (rrc_ciphering_info *)g_tree_lookup(rrc_ciph_info_tree, GINT_TO_POINTER((gint)ueid));
+  if( cipher_info == NULL ){
+    cipher_info = g_new0(rrc_ciphering_info,1);
+
+    /*Initiate tree with START_PS values.*/
+    if(!cipher_info->start_ps)
+      cipher_info->start_ps = g_tree_new_full(rrc_key_cmp,
+                                        NULL,rrc_free_key,rrc_free_value);
+
+    /*Clear and initialize seq_no matrix*/
+    for(i = 0; i< 31; i++){
+      cipher_info->seq_no[i][0] = -1;
+      cipher_info->seq_no[i][1] = -1;
+    }
+    g_tree_insert(rrc_ciph_info_tree, GINT_TO_POINTER((gint)rlcinf->ueid[fpinf->cur_tb]), cipher_info);
+  }
+  return cipher_info;
+}
+
+#include "packet-rrc-fn.c"
 
 
 static int
@@ -366,7 +429,7 @@ rrc_init(void) {
                        rrc_free_key,
                        rrc_free_value);
 
-    rrc_ciph_inf = g_tree_new_full(rrc_key_cmp,
+    rrc_ciph_info_tree = g_tree_new_full(rrc_key_cmp,
                        NULL,      /* data pointer, optional */
                        NULL,
                        rrc_free_value);
@@ -385,7 +448,8 @@ static void
 rrc_cleanup(void) {
     /*Cleanup*/
     g_tree_destroy(hsdsch_muxed_flows);
-    g_tree_destroy(rrc_ciph_inf);
+    g_tree_destroy(rrc_ciph_info_tree);
+    g_tree_destroy(rrc_scrambling_code_urnti);
 }
 
 /*--- proto_register_rrc -------------------------------------------*/
diff --git a/epan/dissectors/asn1/rrc/packet-rrc-template.h b/epan/dissectors/asn1/rrc/packet-rrc-template.h
index 72efe6c20e..8ad8229429 100644
--- a/epan/dissectors/asn1/rrc/packet-rrc-template.h
+++ b/epan/dissectors/asn1/rrc/packet-rrc-template.h
@@ -46,20 +46,20 @@ typedef struct rrc_info
 } rrc_info;
 
 /*Struct for storing ciphering information*/
-typedef struct rrc_ciph_info_
+typedef struct rrc_ciphering_info
 {
-  int seq_no[31][2];    /*Indicates for each Rbid when ciphering starts*/
+  int seq_no[31][2];    /*Indicates for each Rbid when ciphering starts - Indexers are [BearerID][Direction]*/
   GTree * /*guint32*/ start_cs;    /*Start value for CS counter*/
   GTree * /*guint32*/ start_ps;    /*Start value for PS counter*/
   guint32 conf_algo_indicator;    /*Indicates which type of ciphering algorithm used*/
   guint32 int_algo_indiccator;    /*Indicates which type of integrity algorithm used*/
-  unsigned int setup_frame;    /*Store which frame contained this information*/
+  guint32 setup_frame[2];    /*Store which frame contained this information - Indexer is [Direction]*/
   guint32 ps_conf_counters[31][2];    /*This should also be made for CS*/
 
 } rrc_ciphering_info;
 
 extern GTree * hsdsch_muxed_flows;
-extern GTree * rrc_ciph_inf;
+extern GTree * rrc_ciph_info_tree;
 extern GTree * rrc_scrambling_code_urnti;
 extern wmem_tree_t* rrc_rach_urnti_crnti_map;
 
diff --git a/epan/dissectors/asn1/rrc/rrc.cnf b/epan/dissectors/asn1/rrc/rrc.cnf
index f1e2176ae3..2be5a30863 100644
--- a/epan/dissectors/asn1/rrc/rrc.cnf
+++ b/epan/dissectors/asn1/rrc/rrc.cnf
@@ -417,20 +417,46 @@ HandoverFromUTRANCommand-GSM-r6-IEs/gsm-message/single-GSM-Message single-GSM-Me
 %(DEFAULT_BODY)s
 
 #.FN_BODY SecurityModeCommand
+  fp_info            *fpinf;
+  rlc_info           *rlcinf;
+  rrc_ciphering_info *ciphering_info = NULL;
+  guint8              direction;
   col_append_str(actx->pinfo->cinfo, COL_INFO, "SecurityModeCommand");
+
+  fpinf = (fp_info *)p_get_proto_data(wmem_file_scope(), actx->pinfo, proto_fp, 0);
+  rlcinf = (rlc_info *)p_get_proto_data(wmem_file_scope(), actx->pinfo, proto_umts_rlc, 0);
+
+  /*If FP info or RLC info is missing , skip all this*/
+  if(fpinf != NULL && rlcinf != NULL){
+    ciphering_info = get_or_create_cipher_info(fpinf, rlcinf);
+    private_data_set_ciphering_info(actx, ciphering_info);
+  }
 %(DEFAULT_BODY)s
+  if( ciphering_info != NULL ){
+    direction = 0; /* Security Mode Command is from the RNC, direction is always downlink */
+    ciphering_info->setup_frame[direction] = actx->pinfo->num;
+  }
 
 #.FN_BODY SecurityModeComplete
-rrc_ciphering_info * c_inf ;
-fp_info       *fpinf ;
-
+  fp_info            *fpinf;
+  rlc_info           *rlcinf;
+  rrc_ciphering_info *ciphering_info = NULL;
+  guint8              direction;
   col_append_str(actx->pinfo->cinfo, COL_INFO, "SecurityModeComplete");
 
-%(DEFAULT_BODY)s
-
   fpinf = (fp_info *)p_get_proto_data(wmem_file_scope(), actx->pinfo, proto_fp, 0);
-  if(fpinf && ((c_inf = (rrc_ciphering_info *)g_tree_lookup(rrc_ciph_inf, GINT_TO_POINTER(fpinf->com_context_id))) != NULL) ){
-    c_inf->setup_frame = actx->pinfo->num;
+  rlcinf = (rlc_info *)p_get_proto_data(wmem_file_scope(), actx->pinfo, proto_umts_rlc, 0);
+
+  /*If FP info or RLC info is missing , skip all this*/
+  if(fpinf != NULL || rlcinf != NULL){
+    ciphering_info = get_or_create_cipher_info(fpinf, rlcinf);
+    private_data_set_ciphering_info(actx, ciphering_info);
+  }
+
+%(DEFAULT_BODY)s
+  if( ciphering_info != NULL ){
+    direction = 1; /* Security Mode Complete is from the UE, direction is always uplink */
+    ciphering_info->setup_frame[direction] = actx->pinfo->num;
   }
 
 
@@ -978,18 +1004,19 @@ private_data_set_scrambling_code(actx,scrambling_code);
 #.FN_BODY START-Value VAL_PTR = &start_val
   tvbuff_t * start_val;
   fp_info       *fpinf;
-  rrc_ciphering_info * c_inf;
-  int i;
+  rlc_info      *rlcinf;
+  rrc_ciphering_info * ciphering_info;
   guint32 * start;
   enum nas_sys_info_gsm_map cn_domain;
 
 %(DEFAULT_BODY)s
 
-  /*We base this map on communication context from fp*/
-    fpinf = (fp_info *)p_get_proto_data(wmem_file_scope(), actx->pinfo, proto_fp, 0);
+  /*We base this map on User Identity from RLC*/
+  fpinf = (fp_info *)p_get_proto_data(wmem_file_scope(), actx->pinfo, proto_fp, 0);
+  rlcinf = (rlc_info *)p_get_proto_data(wmem_file_scope(), actx->pinfo, proto_umts_rlc, 0);
 
-  /*If no info found, skip all this*/
-  if(fpinf == NULL){
+  /*If FP info or RLC info is missing , skip all this*/
+  if(fpinf == NULL || rlcinf== NULL){
       return offset;
   }
   /*Retrieve the start value for the two ciphering domains*/
@@ -1002,29 +1029,16 @@ private_data_set_scrambling_code(actx,scrambling_code);
       break;
     case RRC_NAS_SYS_INFO_PS:
 
-      /*Find the entry for the communication context (taken from FP)*/
-      if( (c_inf =(rrc_ciphering_info *)g_tree_lookup(rrc_ciph_inf, GINT_TO_POINTER(fpinf->com_context_id))) == NULL ){
-        c_inf = g_new0(rrc_ciphering_info,1);
-
-        /*Initiate tree with START_PS values.*/
-        if(!c_inf->start_ps)
-          c_inf->start_ps = g_tree_new_full(rrc_key_cmp,
-                                            NULL,rrc_free_key,rrc_free_value);
-
-        /*Clear and initialize seq_no matrix*/
-        for(i = 0; i< 31; i++){
-          c_inf->seq_no[i][0] = -1;
-          c_inf->seq_no[i][1] = -1;
-        }
-        g_tree_insert(rrc_ciph_inf, GINT_TO_POINTER(fpinf->com_context_id), c_inf);
-      }
+      /*Find the entry for the UE ID(taken from RLC)*/
+      ciphering_info = get_or_create_cipher_info(fpinf, rlcinf);
+      private_data_set_ciphering_info(actx, ciphering_info);
 
       /*Retrieve and store the value*/
       start = g_new(guint32,1);
       *start = tvb_get_bits32(start_val,0,20,ENC_BIG_ENDIAN);
-      if(c_inf && c_inf->start_ps)
+      if(ciphering_info && ciphering_info->start_ps)
         /*Insert the value based on current frame num since this might vary over time*/
-        g_tree_insert(c_inf->start_ps, GUINT_TO_POINTER(actx->pinfo->num), start);
+        g_tree_insert(ciphering_info->start_ps, GUINT_TO_POINTER(actx->pinfo->num), start);
 
       break;
     default:
@@ -1033,36 +1047,43 @@ private_data_set_scrambling_code(actx,scrambling_code);
   private_data_set_cn_domain(actx, RRC_NAS_SYS_UNKNOWN);
 
 #.FN_BODY RB-ActivationTimeInfo
-  fp_info       *fpinf;
-  rrc_ciphering_info * c_inf;
-
-
+  fp_info            *fpinf;
+  rlc_info           *rlcinf;
+  rrc_ciphering_info *ciphering_info;
+  guint32 rbid;
+  guint32 rlc_ciphering_sqn;
 
   fpinf = (fp_info *)p_get_proto_data(wmem_file_scope(), actx->pinfo, proto_fp, 0);
+  rlcinf = (rlc_info *)p_get_proto_data(wmem_file_scope(), actx->pinfo, proto_umts_rlc, 0);
 
 %(DEFAULT_BODY)s
 
-  /*If no info found, skip all this*/
-  if(fpinf == NULL){
+  /*If FP info or RLC info is missing , skip all this*/
+  if(fpinf == NULL || rlcinf== NULL){
     return offset;
   }
-  /*This should not happen*/
-  if( (c_inf = (rrc_ciphering_info *)g_tree_lookup(rrc_ciph_inf, GINT_TO_POINTER(fpinf->com_context_id))) == NULL ){
+
+  ciphering_info = private_data_get_ciphering_info(actx);
+  if( ciphering_info == NULL ){
     return offset;
   }
+
+  rbid = private_data_get_rbid(actx);
+  rlc_ciphering_sqn = private_data_get_rlc_ciphering_sqn(actx);
   /*Set the ciphering activation frame information*/
-  c_inf->seq_no[rbid][fpinf->is_uplink] = activation_frame;
+  ciphering_info->seq_no[rbid][fpinf->is_uplink] = rlc_ciphering_sqn;
 
 
 #.FN_BODY RB-Identity VAL_PTR = &rbid
-
+guint32 rbid;
 %(DEFAULT_BODY)s
+private_data_set_rbid(actx, rbid);
 
 
-
-#.FN_BODY RLC-SequenceNumber VAL_PTR = &activation_frame
-
+#.FN_BODY RLC-SequenceNumber VAL_PTR = &rlc_ciphering_sqn
+guint32 rlc_ciphering_sqn;
 %(DEFAULT_BODY)s
+private_data_set_rlc_ciphering_sqn(actx, rlc_ciphering_sqn);
 
 #.FN_BODY DL-DCCH-MessageType VAL_PTR = &msg_type
 %(DEFAULT_BODY)s