From c623883f78200fb5596c3fb276cf83395cb7a6fe Mon Sep 17 00:00:00 2001
From: baldurk <baldurk@baldurk.org>
Date: Mon, 1 Aug 2016 22:31:23 +0200
Subject: [PATCH] Parse a config file and determine a whitelist of IPs to
 listen to.

* The remote server is going to start being responsible for more things
  soon, and one of those is launching programs to capture. Since this is
  remote code execution by design, we want to be able to lock down who
  can communicate with the server.
* By default, only private LAN IP ranges are listened to.
---
 renderdoc/core/remote_replay.cpp | 88 ++++++++++++++++++++++++++++++--
 1 file changed, 84 insertions(+), 4 deletions(-)

diff --git a/renderdoc/core/remote_replay.cpp b/renderdoc/core/remote_replay.cpp
index 8643d47db..78695ab95 100644
--- a/renderdoc/core/remote_replay.cpp
+++ b/renderdoc/core/remote_replay.cpp
@@ -77,10 +77,67 @@ void RenderDoc::BecomeRemoteServer(const char *listenhost, uint16_t port, volati
   if(sock == NULL)
     return;
 
-  Serialiser ser("", Serialiser::WRITING, false);
-
   bool newlyReady = true;
 
+  std::vector<std::pair<uint32_t, uint32_t> > listenRanges;
+
+  FILE *f = FileIO::fopen(FileIO::GetAppFolderFilename("replayserver.conf").c_str(), "r");
+
+  while(f && !FileIO::feof(f))
+  {
+    string line = FileIO::getline(f);
+
+    size_t nonws = line.find_first_not_of("\t ");
+
+    // skip blank lines
+    if(nonws == string::npos)
+      continue;
+
+    // skip comments
+    if(line[nonws] == '#')
+      continue;
+
+    uint32_t ip = 0, mask = 0;
+
+    // CIDR notation
+    bool found = Network::ParseIPRangeCIDR(line.c_str() + nonws, ip, mask);
+
+    if(found)
+    {
+      listenRanges.push_back(std::make_pair(ip, mask));
+      continue;
+    }
+
+    RDCLOG("Malformed line '%s'. Expect CIDR notation: aaa.bbb.ccc.ddd/nn", line.c_str());
+  }
+
+  if(f)
+    FileIO::fclose(f);
+
+  if(listenRanges.empty())
+  {
+    RDCLOG("No whitelist IP ranges configured - using default private IP ranges.");
+    RDCLOG(
+        "Create a config file replayserver.conf in ~/.renderdoc or %%APPDATA%%/renderdoc to narrow "
+        "this down or accept connections from more ranges.");
+
+    listenRanges.push_back(std::make_pair(Network::MakeIP(10, 0, 0, 0), 0xff000000));
+    listenRanges.push_back(std::make_pair(Network::MakeIP(172, 16, 0, 0), 0xfff00000));
+    listenRanges.push_back(std::make_pair(Network::MakeIP(192, 168, 0, 0), 0xffff0000));
+  }
+
+  RDCLOG("Allowing connections from:");
+
+  for(size_t i = 0; i < listenRanges.size(); i++)
+  {
+    uint32_t ip = listenRanges[i].first;
+    uint32_t mask = listenRanges[i].second;
+
+    RDCLOG("%u.%u.%u.%u / %u.%u.%u.%u", Network::GetIPOctet(ip, 0), Network::GetIPOctet(ip, 1),
+           Network::GetIPOctet(ip, 2), Network::GetIPOctet(ip, 3), Network::GetIPOctet(mask, 0),
+           Network::GetIPOctet(mask, 1), Network::GetIPOctet(mask, 2), Network::GetIPOctet(mask, 3));
+  }
+
   while(!killReplay)
   {
     if(newlyReady)
@@ -106,9 +163,32 @@ void RenderDoc::BecomeRemoteServer(const char *listenhost, uint16_t port, volati
       continue;
     }
 
-    newlyReady = true;
+    uint32_t ip = client->GetRemoteIP();
 
-    RDCLOG("Connection received.");
+    RDCLOG("Connection received from %u.%u.%u.%u.", Network::GetIPOctet(ip, 0),
+           Network::GetIPOctet(ip, 1), Network::GetIPOctet(ip, 2), Network::GetIPOctet(ip, 3));
+
+    bool valid = false;
+
+    for(size_t i = 0; i < listenRanges.size(); i++)
+    {
+      if(Network::MatchIPMask(ip, listenRanges[i].first, listenRanges[i].second))
+      {
+        valid = true;
+        break;
+      }
+    }
+
+    if(!valid)
+    {
+      RDCLOG("Doesn't match any listen range, closing connection.");
+      SAFE_DELETE(client);
+      continue;
+    }
+
+    Serialiser ser("", Serialiser::WRITING, false);
+
+    newlyReady = true;
 
     map<RDCDriver, string> drivers = RenderDoc::Inst().GetRemoteDrivers();