GTP: Use direct hashing in the session table

The session table maps frames (which are 32 bit uints that
start at 1) to sessions (which are also 32 bit uints that
start at 1), so use GUINT_TO_POINTER and the direct hash
functions instead of creating extra file scope pointers.

2 files changed, 41 insertions, 43 deletions

diff --git a/epan/dissectors/packet-gtp.c b/epan/dissectors/packet-gtp.c
index dfc145df83..989ef8fa69 100644
--- a/epan/dissectors/packet-gtp.c
+++ b/epan/dissectors/packet-gtp.c
@@ -2553,13 +2553,8 @@ remove_frame_info(guint32 *f) {
 
 void
 add_gtp_session(guint32 frame, guint32 session) {
-    guint32 *f, *session_count;
 
-    f = wmem_new0(wmem_file_scope(), guint32);
-    session_count = wmem_new0(wmem_file_scope(), guint32);
-    *f = frame;
-    *session_count = session;
-    g_hash_table_insert(session_table, f, session_count);
+    g_hash_table_insert(session_table, GUINT_TO_POINTER(frame), GUINT_TO_POINTER(session));
 }
 
 gboolean
@@ -2612,9 +2607,10 @@ fill_map(wmem_list_t *teid_list, wmem_list_t *ip_list, guint32 frame) {
     wmem_list_frame_t *elem_ip, *elem_teid;
     gtp_info_t *gtp_info;
     wmem_list_t * info_list; /* List of <teids,frames>*/
-    guint32 *f, *session, *fr, *session_count;
+    guint32 *f;
+    gpointer session_p, fr_p;
     GHashTableIter iter;
-    guint32 teid;
+    guint32 teid, session, fr;
     gchar *ip;
 
     elem_ip = wmem_list_head(ip_list);
@@ -2635,16 +2631,18 @@ fill_map(wmem_list_t *teid_list, wmem_list_t *ip_list, guint32 frame) {
             gtp_info->teid = teid;
             gtp_info->frame = *f;
             if (info_exists(gtp_info, info_list)) {
-                /* If the teid and ip already existed, that means that we need to remove old info about that session */
+                /* If the teid and ip already maps to a session, that means
+                 * that we need to remove old info about that session */
                 /* We look for its session ID */
-                session = (guint32 *)g_hash_table_lookup(session_table, f);
+                session = GPOINTER_TO_UINT(g_hash_table_lookup(session_table, GUINT_TO_POINTER(frame)));
                 if (session) {
                     g_hash_table_iter_init(&iter, session_table);
-                    while (g_hash_table_iter_next(&iter, (gpointer*)&fr, (gpointer*)&session_count)) {
+                    while (g_hash_table_iter_next(&iter, &fr_p, &session_p)) {
                         /* If the msg has the same session ID and it's not the upd req we have to remove its info */
-                        if (*session_count == *session) {
+                        if (GPOINTER_TO_UINT(session_p) == session) {
                             /* If it's the session we are looking for, we remove all the frame information */
-                            remove_frame_info(fr);
+                            fr = GPOINTER_TO_UINT(fr_p);
+                            remove_frame_info(&fr);
                         }
                     }
                 }
@@ -4268,7 +4266,7 @@ static gtp_msg_hash_t *
 gtp_match_response(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, gint seq_nr, guint msgtype, gtp_conv_info_t *gtp_info, guint8 last_cause)
 {
     gtp_msg_hash_t   gcr, *gcrp = NULL;
-    guint32 *session;
+    guint32 session;
 
     gcr.seq_nr=seq_nr;
     gcr.req_time = pinfo->abs_ts;
@@ -4391,11 +4389,11 @@ gtp_match_response(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, gint
                 if (!PINFO_FD_VISITED(pinfo) && gtp_version == 1) {
                     /* GTP session */
                     /* If it does not have any session assigned yet */
-                    session = (guint32 *)g_hash_table_lookup(session_table, &pinfo->num);
+                    session = GPOINTER_TO_UINT(g_hash_table_lookup(session_table, GUINT_TO_POINTER(pinfo->num)));
                     if (!session) {
-                        session = (guint32 *)g_hash_table_lookup(session_table, &gcrp->req_frame);
-                        if (session != NULL) {
-                            add_gtp_session(pinfo->num, *session);
+                        session = GPOINTER_TO_UINT(g_hash_table_lookup(session_table, GUINT_TO_POINTER(gcrp->req_frame)));
+                        if (session) {
+                            add_gtp_session(pinfo->num, session);
                         }
                     }
 
@@ -9808,14 +9806,14 @@ decode_gtp_unknown(tvbuff_t * tvb, int offset, packet_info * pinfo, proto_tree *
 static void
 track_gtp_session(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, gtp_hdr_t * gtp_hdr, wmem_list_t *teid_list, wmem_list_t *ip_list, guint32 last_teid, address last_ip)
 {
-    guint32 *session, frame_teid_cp;
+    guint32 session, frame_teid_cp;
     proto_item *it;
 
     /* GTP session */
     if (tree) {
-        session = (guint32*)g_hash_table_lookup(session_table, &pinfo->num);
+        session = GPOINTER_TO_UINT(g_hash_table_lookup(session_table, GUINT_TO_POINTER(pinfo->num)));
         if (session) {
-            it = proto_tree_add_uint(tree, hf_gtp_session, tvb, 0, 0, *session);
+            it = proto_tree_add_uint(tree, hf_gtp_session, tvb, 0, 0, session);
             proto_item_set_generated(it);
         }
     }
@@ -9823,7 +9821,7 @@ track_gtp_session(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, gtp_hd
 
     if (!PINFO_FD_VISITED(pinfo) && gtp_version == 1) {
         /* If the message does not have any session ID */
-        session = (guint32*)g_hash_table_lookup(session_table, &pinfo->num);
+        session = GPOINTER_TO_UINT(g_hash_table_lookup(session_table, GUINT_TO_POINTER(pinfo->num)));
         if (!session) {
             /* If the message is not a CPDPCRES, CPDPCREQ, UPDPREQ, UPDPRES then we remove its information from teid and ip lists */
             if ((gtp_hdr->message != GTP_MSG_CREATE_PDP_RESP && gtp_hdr->message != GTP_MSG_CREATE_PDP_REQ && gtp_hdr->message != GTP_MSG_UPDATE_PDP_RESP
@@ -9841,10 +9839,10 @@ track_gtp_session(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, gtp_hd
                 /* If this is an error indication then we have to check the session id that belongs to the message with the same data teid and ip */
                 if (gtp_hdr->message == GTP_MSG_ERR_IND) {
                     if (get_frame(last_ip, last_teid, &frame_teid_cp) == 1) {
-                        session = (guint32*)g_hash_table_lookup(session_table, &frame_teid_cp);
-                        if (session != NULL) {
+                        session = GPOINTER_TO_UINT(g_hash_table_lookup(session_table, GUINT_TO_POINTER(frame_teid_cp)));
+                        if (session) {
                             /* We add the corresponding session to the session list*/
-                            add_gtp_session(pinfo->num, *session);
+                            add_gtp_session(pinfo->num, session);
                         }
                     }
                 }
@@ -9853,10 +9851,10 @@ track_gtp_session(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, gtp_hd
                     the corresponding session ID */
                     if ((get_frame(pinfo->dst, (guint32)gtp_hdr->teid, &frame_teid_cp) == 1)) {
                         /* Then we have to set its session ID */
-                        session = (guint32*)g_hash_table_lookup(session_table, &frame_teid_cp);
-                        if (session != NULL) {
+                        session = GPOINTER_TO_UINT(g_hash_table_lookup(session_table, GUINT_TO_POINTER(frame_teid_cp)));
+                        if (session) {
                             /* We add the corresponding session to the list so that when a response came we can associate its session ID*/
-                            add_gtp_session(pinfo->num, *session);
+                            add_gtp_session(pinfo->num, session);
                         }
                     }
                 }
@@ -10900,7 +10898,7 @@ static void
 gtp_init(void)
 {
     gtp_session_count = 1;
-    session_table = g_hash_table_new(g_int_hash, g_int_equal);
+    session_table = g_hash_table_new(g_direct_hash, g_direct_equal);
     frame_tree = wmem_tree_new(wmem_file_scope());
 }
 
diff --git a/epan/dissectors/packet-gtpv2.c b/epan/dissectors/packet-gtpv2.c
index d4d2ab2375..d82800981c 100644
--- a/epan/dissectors/packet-gtpv2.c
+++ b/epan/dissectors/packet-gtpv2.c
@@ -3367,7 +3367,7 @@ dissect_gtpv2_f_teid(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_
     int    offset = 0;
     guint8 flags;
     address *ipv4 = NULL, *ipv6 = NULL;
-    guint32 teid_cp, *teid, *session;
+    guint32 teid_cp, *teid, session;
 
     flags = tvb_get_guint8(tvb, offset);
     proto_tree_add_item(tree, hf_gtpv2_f_teid_v4, tvb, offset, 1, ENC_BIG_ENDIAN);
@@ -3402,7 +3402,7 @@ dissect_gtpv2_f_teid(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_
     }
 
     if (g_gtp_session && args) {
-        session = (guint32 *)g_hash_table_lookup(session_table, &pinfo->num);
+        session = GPOINTER_TO_UINT(g_hash_table_lookup(session_table, GUINT_TO_POINTER(pinfo->num)));
         if (!session) {
             /* We save the teid so that we could assignate its corresponding session ID later */
             args->last_teid = teid_cp;
@@ -8507,7 +8507,7 @@ static gtpv2_msg_hash_t *
 gtpv2_match_response(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, gint seq_nr, guint msgtype, gtpv2_conv_info_t *gtpv2_info, guint8 last_cause)
 {
     gtpv2_msg_hash_t   gcr, *gcrp = NULL;
-    guint32 *session;
+    guint32 session;
 
     gcr.seq_nr = seq_nr;
     gcr.req_time = pinfo->abs_ts;
@@ -8660,11 +8660,11 @@ gtpv2_match_response(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, gin
             if (g_gtp_session && !PINFO_FD_VISITED(pinfo)) {
                 /* GTP session */
                 /* If it's not already in the list */
-                session = (guint32 *)g_hash_table_lookup(session_table, &pinfo->num);
+                session = GPOINTER_TO_UINT(g_hash_table_lookup(session_table, GUINT_TO_POINTER(pinfo->num)));
                 if (!session) {
-                    session = (guint32 *)g_hash_table_lookup(session_table, &gcrp->req_frame);
-                    if (session != NULL) {
-                        add_gtp_session(pinfo->num, *session);
+                    session = GPOINTER_TO_UINT(g_hash_table_lookup(session_table, GUINT_TO_POINTER(gcrp->req_frame)));
+                    if (session) {
+                        add_gtp_session(pinfo->num, session);
                     }
                 }
 
@@ -8681,21 +8681,21 @@ gtpv2_match_response(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, gin
 static void
 track_gtpv2_session(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, gtpv2_hdr_t * gtpv2_hdr, wmem_list_t *teid_list, wmem_list_t *ip_list, guint32 last_teid _U_, address last_ip _U_)
 {
-    guint32 *session, frame_teid_cp;
+    guint32 session, frame_teid_cp;
     proto_item *it;
 
     /* GTP session */
     if (tree) {
-        session = (guint32*)g_hash_table_lookup(session_table, &pinfo->num);
+        session = GPOINTER_TO_UINT(g_hash_table_lookup(session_table, GUINT_TO_POINTER(pinfo->num)));
         if (session) {
-            it = proto_tree_add_uint(tree, hf_gtpv2_session, tvb, 0, 0, *session);
+            it = proto_tree_add_uint(tree, hf_gtpv2_session, tvb, 0, 0, session);
             proto_item_set_generated(it);
         }
     }
 
     if (!PINFO_FD_VISITED(pinfo)) {
         /* If the message does not have any session ID */
-        session = (guint32*)g_hash_table_lookup(session_table, &pinfo->num);
+        session = GPOINTER_TO_UINT(g_hash_table_lookup(session_table, GUINT_TO_POINTER(pinfo->num)));
         if (!session) {
             /* If the message is not a CSESRES, CSESREQ, UBEAREQ, UBEARES, CBEAREQ, CBEARES, MBEAREQ or MBEARES then we remove its information from teid and ip lists */
             if ((gtpv2_hdr->message != GTPV2_CREATE_SESSION_RESPONSE && gtpv2_hdr->message != GTPV2_CREATE_SESSION_REQUEST && gtpv2_hdr->message != GTPV2_UPDATE_BEARER_RESPONSE
@@ -8716,10 +8716,10 @@ track_gtpv2_session(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, gtpv
                 the corresponding session ID */
                 if ((get_frame(pinfo->dst, (guint32)gtpv2_hdr->teid, &frame_teid_cp) == 1)) {
                     /* Then we have to set its session ID */
-                    session = (guint32*)g_hash_table_lookup(session_table, &frame_teid_cp);
-                    if (session != NULL) {
+                    session = GPOINTER_TO_UINT(g_hash_table_lookup(session_table, GUINT_TO_POINTER(frame_teid_cp)));
+                    if (session) {
                         /* We add the corresponding session to the list so that when a response came we can associate its session ID*/
-                        add_gtp_session(pinfo->num, *session);
+                        add_gtp_session(pinfo->num, session);
                     }
                 }
             }