From: Amos Jeffries <squid3@treenet.co.nz>
Date: Sun, 8 Feb 2015 06:07:18 +0000 (-0800)
Subject: Update DNS engine to C++11 random
X-Git-Tag: merge-candidate-3-v1~109^2~10
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=011b1672debd2f719bb987837fa87aece2d07119;p=thirdparty%2Fsquid.git

Update DNS engine to C++11 random
---

diff --git a/src/dns_internal.cc b/src/dns_internal.cc
index 44b4932126..a3305e8a89 100644
--- a/src/dns_internal.cc
+++ b/src/dns_internal.cc
@@ -40,6 +40,7 @@
 #include <arpa/nameser.h>
 #endif
 #include <cerrno>
+#include <random>
 #if HAVE_RESOLV_H
 #include <resolv.h>
 #endif
@@ -1058,11 +1059,14 @@ idnsFindQuery(unsigned short id)
 }
 
 static unsigned short
-idnsQueryID(void)
+idnsQueryID()
 {
-    unsigned short id = squid_random() & 0xFFFF;
+    // NP: apparently ranlux are faster, but not quite as "proven"
+    static std::mt19937 mt(static_cast<uint32_t>(getCurrentTime() & 0xFFFFFFFF));
+    unsigned short id = mt() & 0xFFFF;
     unsigned short first_id = id;
 
+    // ensure temporal uniqueness by looking for an existing use
     while (idnsFindQuery(id)) {
         ++id;