[Libreoffice-commits] online.git: loolwsd/LOOLKit.cpp loolwsd/Util.cpp loolwsd/Util.hpp

[Ashod Nakashian]

 loolwsd/LOOLKit.cpp |    5 +++--
 loolwsd/Util.cpp    |   17 ++++++++++++++++-
 loolwsd/Util.hpp    |    3 ++-
 3 files changed, 21 insertions(+), 4 deletions(-)

New commits:
commit 019aed134e17b69e615a5990eab8c471184973e9
Author: Ashod Nakashian <ashod.nakashian at collabora.co.uk>
Date:   Sat Mar 12 10:15:45 2016 -0500

    loolwsd: using random jailId
    
    Change-Id: Ie9501e4346a124994270ca1fac61869ed04b9b72
    Reviewed-on: https://gerrit.libreoffice.org/23213
    Reviewed-by: Ashod Nakashian <ashnakash at gmail.com>
    Tested-by: Ashod Nakashian <ashnakash at gmail.com>

diff --git a/loolwsd/LOOLKit.cpp b/loolwsd/LOOLKit.cpp
index 5414a26..4fb6141 100644
--- a/loolwsd/LOOLKit.cpp
+++ b/loolwsd/LOOLKit.cpp
@@ -414,7 +414,7 @@ public:
                        [this](const std::string& id, const std::string& uri, const std::string& docPassword, bool isDocPasswordProvided) { return onLoad(id, uri, docPassword, isDocPasswordProvided); },
                        [this](const std::string& id) { onUnload(id); });
         // child -> 0,  sessionId -> 1, PID -> 2
-        const std::string hello("child " + sessionId + " " + std::to_string(Process::id()));
+        const std::string hello("child " + sessionId + " " + _jailId);
         session->sendTextFrame(hello);
 
         auto thread = std::make_shared<Connection>(session, ws);
@@ -764,6 +764,7 @@ void lokit_main(const std::string& childRoot,
 #ifdef LOOLKIT_NO_MAIN
     // Reinitialize logging when forked.
     Log::initialize("kit");
+    Util::rng::reseed();
 #endif
 
     struct pollfd pollPipeBroker;
@@ -782,7 +783,7 @@ void lokit_main(const std::string& childRoot,
 
     std::map<std::string, std::shared_ptr<Document>> _documents;
 
-    static const std::string jailId = std::to_string(Process::id());
+    static const std::string jailId = Util::encodeId(Util::rng::getNext());
     static const std::string process_name = "loolkit";
 
     if (prctl(PR_SET_NAME, reinterpret_cast<unsigned long>(process_name.c_str()), 0, 0, 0) != 0)
diff --git a/loolwsd/Util.cpp b/loolwsd/Util.cpp
index 7485a9e..5fc9a2a 100644
--- a/loolwsd/Util.cpp
+++ b/loolwsd/Util.cpp
@@ -65,7 +65,22 @@ namespace rng
 {
     static std::random_device _rd;
     static std::mutex _rngMutex;
-    static std::mt19937_64 _rng = std::mt19937_64(_rd());
+
+    // Create the prng with a random-device for seed.
+    // If we don't have a hardware random-device, we will get the same seed.
+    // In that case we are better off with an arbitrary, but changing, seed.
+    static std::mt19937_64 _rng = std::mt19937_64(_rd.entropy()
+                                                ? _rd()
+                                                : (clock() + getpid()));
+
+    // A new seed is used to shuffle the sequence.
+    // N.B. Always reseed after getting forked!
+    void reseed()
+    {
+        _rng.seed(_rd.entropy() ? _rd() : (clock() + getpid()));
+    }
+
+    // Returns a new random number.
     unsigned getNext()
     {
         std::unique_lock<std::mutex> lock(_rngMutex);
diff --git a/loolwsd/Util.hpp b/loolwsd/Util.hpp
index 1e6e515..2e83ea8 100644
--- a/loolwsd/Util.hpp
+++ b/loolwsd/Util.hpp
@@ -50,7 +50,8 @@ namespace Util
 {
     namespace rng
     {
-       unsigned getNext();
+        void reseed();
+        unsigned getNext();
     }
 
     /// Encode an integral ID into a string, with padding support.