From 71ea4f4fa20efb525ae20b5cf59cb493c152854c Mon Sep 17 00:00:00 2001
From: Jason Rhinelander <jason@imaginary.ca>
Date: Mon, 19 Sep 2022 11:34:27 -0300
Subject: [PATCH] RPC: Relax token/range argument handling

- Accept empty string or `null` for token to mean "no token."
- Accept `null` for range to mean "default range."
- Don't use a default range (::0/0) in lokinet-vpn because this will
  fail if IPv6 ranges aren't supported on the platform (e.g. on
  Windows), and isn't necessary: if we omit it then the rpc code already
  uses ::0/0 or 0.0.0.0/0 by default, as needed.
---
 daemon/lokinet-vpn.cpp   | 28 +++++++++++-----------------
 llarp/rpc/rpc_server.cpp | 10 +++++-----
 2 files changed, 16 insertions(+), 22 deletions(-)

diff --git a/daemon/lokinet-vpn.cpp b/daemon/lokinet-vpn.cpp
index dff05d0ee..c5c6a4f50 100644
--- a/daemon/lokinet-vpn.cpp
+++ b/daemon/lokinet-vpn.cpp
@@ -74,8 +74,8 @@ main(int argc, char* argv[])
   oxenmq::address rpcURL("tcp://127.0.0.1:1190");
   std::string exitAddress;
   std::string endpoint = "default";
-  std::optional<std::string> token;
-  std::string range = "::/0";
+  std::string token;
+  std::optional<std::string> range;
   oxenmq::LogLevel logLevel = oxenmq::LogLevel::warn;
   bool goUp = false;
   bool goDown = false;
@@ -216,20 +216,11 @@ main(int argc, char* argv[])
   }
   if (goUp)
   {
-    std::optional<nlohmann::json> maybe_result;
-    if (token.has_value())
-    {
-      maybe_result = LMQ_Request(
-          lmq,
-          connID,
-          "llarp.exit",
-          nlohmann::json{{"exit", exitAddress}, {"range", range}, {"token", *token}});
-    }
-    else
-    {
-      maybe_result = LMQ_Request(
-          lmq, connID, "llarp.exit", nlohmann::json{{"exit", exitAddress}, {"range", range}});
-    }
+    nlohmann::json opts{{"exit", exitAddress}, {"token", token}};
+    if (range)
+      opts["range"] = *range;
+
+    auto maybe_result = LMQ_Request(lmq, connID, "llarp.exit", opts);
 
     if (not maybe_result.has_value())
     {
@@ -245,7 +236,10 @@ main(int argc, char* argv[])
   }
   if (goDown)
   {
-    LMQ_Request(lmq, connID, "llarp.exit", nlohmann::json{{"range", range}, {"unmap", true}});
+    nlohmann::json opts{{"unmap", true}};
+    if (range)
+      opts["range"] = *range;
+    LMQ_Request(lmq, connID, "llarp.exit", std::move(opts));
   }
 
   return 0;
diff --git a/llarp/rpc/rpc_server.cpp b/llarp/rpc/rpc_server.cpp
index ecff8c3f3..b07000d0c 100644
--- a/llarp/rpc/rpc_server.cpp
+++ b/llarp/rpc/rpc_server.cpp
@@ -469,7 +469,7 @@ namespace llarp::rpc
                   map = false;
                 }
                 const auto range_itr = obj.find("range");
-                if (range_itr == obj.end())
+                if (range_itr == obj.end() or range_itr->is_null())
                 {
                   // platforms without ipv6 support will shit themselves
                   // here if we give them an exit mapping that is ipv6
@@ -492,9 +492,9 @@ namespace llarp::rpc
                   reply(CreateJSONError("ipv6 ranges not supported on this platform"));
                   return;
                 }
-                std::optional<std::string> token;
+                std::string token;
                 const auto token_itr = obj.find("token");
-                if (token_itr != obj.end())
+                if (token_itr != obj.end() and not token_itr->is_null())
                 {
                   token = token_itr->get<std::string>();
                 }
@@ -518,10 +518,10 @@ namespace llarp::rpc
                       ep->MapExitRange(range, addr);
 
                       bool shouldSendAuth = false;
-                      if (token.has_value())
+                      if (not token.empty())
                       {
                         shouldSendAuth = true;
-                        ep->SetAuthInfoForEndpoint(*exit, service::AuthInfo{*token});
+                        ep->SetAuthInfoForEndpoint(*exit, service::AuthInfo{token});
                       }
                       auto onGoodResult = [r, reply](std::string reason) {
                         if (r->HasClientExit())