dnsproxy: Randomize the transaction id

diff --git a/src/dnsproxy.c b/src/dnsproxy.c
index 49651a2..ea7a122 100644 (file)
--- a/src/dnsproxy.c
+++ b/src/dnsproxy.c
@@ -24,6 +24,7 @@
 #endif
 
 #include <errno.h>
+#include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
 #include <stdint.h>
@@ -183,10 +184,14 @@ static int cache_refcount;
 static GSList *server_list = NULL;
 static GSList *request_list = NULL;
 static GSList *request_pending_list = NULL;
-static guint16 request_id = 0x0000;
 static GHashTable *listener_table = NULL;
 static time_t next_refresh;
 
+static guint16 get_id()
+{
+       return random();
+}
+
 static int protocol_offset(int protocol)
 {
        switch (protocol) {
@@ -2383,13 +2388,9 @@ static gboolean tcp_listener_event(GIOChannel *channel, GIOCondition condition,
        req->client_sk = client_sk;
        req->protocol = IPPROTO_TCP;
 
-       request_id += 2;
-       if (request_id == 0x0000 || request_id == 0xffff)
-               request_id += 2;
-
        req->srcid = buf[2] | (buf[3] << 8);
-       req->dstid = request_id;
-       req->altid = request_id + 1;
+       req->dstid = get_id();
+       req->altid = get_id();
        req->request_len = len;
 
        buf[2] = req->dstid & 0xff;
@@ -2502,13 +2503,9 @@ static gboolean udp_listener_event(GIOChannel *channel, GIOCondition condition,
        req->client_sk = 0;
        req->protocol = IPPROTO_UDP;
 
-       request_id += 2;
-       if (request_id == 0x0000 || request_id == 0xffff)
-               request_id += 2;
-
        req->srcid = buf[0] | (buf[1] << 8);
-       req->dstid = request_id;
-       req->altid = request_id + 1;
+       req->dstid = get_id();
+       req->altid = get_id();
        req->request_len = len;
 
        buf[0] = req->dstid & 0xff;
@@ -2786,6 +2783,8 @@ int __connman_dnsproxy_init(void)
 
        DBG("");
 
+       srandom(time(NULL));
+
        listener_table = g_hash_table_new_full(g_str_hash, g_str_equal,
                                                        g_free, g_free);
        err = __connman_dnsproxy_add_listener("lo");