diff --git a/src/libstore/daemon.cc b/src/libstore/daemon.cc
index fc14eda3c..6533b2f58 100644
--- a/src/libstore/daemon.cc
+++ b/src/libstore/daemon.cc
@@ -269,26 +269,21 @@ struct ClientSettings
 };
 
 static void performOp(TunnelLogger * logger, ref<Store> store,
-    TrustedFlag trusted, RecursiveFlag recursive, WorkerProto::Version clientVersion,
-    Source & from, BufferedSink & to, WorkerProto::Op op)
+    TrustedFlag trusted, RecursiveFlag recursive,
+    WorkerProto::BasicServerConnection & conn,
+    WorkerProto::Op op)
 {
-    WorkerProto::ReadConn rconn {
-        .from = from,
-        .version = clientVersion,
-    };
-    WorkerProto::WriteConn wconn {
-        .to = to,
-        .version = clientVersion,
-    };
+    WorkerProto::ReadConn rconn(conn);
+    WorkerProto::WriteConn wconn(conn);
 
     switch (op) {
 
     case WorkerProto::Op::IsValidPath: {
-        auto path = store->parseStorePath(readString(from));
+        auto path = store->parseStorePath(readString(conn.from));
         logger->startWork();
         bool result = store->isValidPath(path);
         logger->stopWork();
-        to << result;
+        conn.to << result;
         break;
     }
 
@@ -296,8 +291,8 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         auto paths = WorkerProto::Serialise<StorePathSet>::read(*store, rconn);
 
         SubstituteFlag substitute = NoSubstitute;
-        if (GET_PROTOCOL_MINOR(clientVersion) >= 27) {
-            substitute = readInt(from) ? Substitute : NoSubstitute;
+        if (GET_PROTOCOL_MINOR(conn.protoVersion) >= 27) {
+            substitute = readInt(conn.from) ? Substitute : NoSubstitute;
         }
 
         logger->startWork();
@@ -311,13 +306,13 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     }
 
     case WorkerProto::Op::HasSubstitutes: {
-        auto path = store->parseStorePath(readString(from));
+        auto path = store->parseStorePath(readString(conn.from));
         logger->startWork();
         StorePathSet paths; // FIXME
         paths.insert(path);
         auto res = store->querySubstitutablePaths(paths);
         logger->stopWork();
-        to << (res.count(path) != 0);
+        conn.to << (res.count(path) != 0);
         break;
     }
 
@@ -331,11 +326,11 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     }
 
     case WorkerProto::Op::QueryPathHash: {
-        auto path = store->parseStorePath(readString(from));
+        auto path = store->parseStorePath(readString(conn.from));
         logger->startWork();
         auto hash = store->queryPathInfo(path)->narHash;
         logger->stopWork();
-        to << hash.to_string(HashFormat::Base16, false);
+        conn.to << hash.to_string(HashFormat::Base16, false);
         break;
     }
 
@@ -343,7 +338,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     case WorkerProto::Op::QueryReferrers:
     case WorkerProto::Op::QueryValidDerivers:
     case WorkerProto::Op::QueryDerivationOutputs: {
-        auto path = store->parseStorePath(readString(from));
+        auto path = store->parseStorePath(readString(conn.from));
         logger->startWork();
         StorePathSet paths;
         if (op == WorkerProto::Op::QueryReferences)
@@ -360,16 +355,16 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     }
 
     case WorkerProto::Op::QueryDerivationOutputNames: {
-        auto path = store->parseStorePath(readString(from));
+        auto path = store->parseStorePath(readString(conn.from));
         logger->startWork();
         auto names = store->readDerivation(path).outputNames();
         logger->stopWork();
-        to << names;
+        conn.to << names;
         break;
     }
 
     case WorkerProto::Op::QueryDerivationOutputMap: {
-        auto path = store->parseStorePath(readString(from));
+        auto path = store->parseStorePath(readString(conn.from));
         logger->startWork();
         auto outputs = store->queryPartialDerivationOutputMap(path);
         logger->stopWork();
@@ -378,37 +373,37 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     }
 
     case WorkerProto::Op::QueryDeriver: {
-        auto path = store->parseStorePath(readString(from));
+        auto path = store->parseStorePath(readString(conn.from));
         logger->startWork();
         auto info = store->queryPathInfo(path);
         logger->stopWork();
-        to << (info->deriver ? store->printStorePath(*info->deriver) : "");
+        conn.to << (info->deriver ? store->printStorePath(*info->deriver) : "");
         break;
     }
 
     case WorkerProto::Op::QueryPathFromHashPart: {
-        auto hashPart = readString(from);
+        auto hashPart = readString(conn.from);
         logger->startWork();
         auto path = store->queryPathFromHashPart(hashPart);
         logger->stopWork();
-        to << (path ? store->printStorePath(*path) : "");
+        conn.to << (path ? store->printStorePath(*path) : "");
         break;
     }
 
     case WorkerProto::Op::AddToStore: {
-        if (GET_PROTOCOL_MINOR(clientVersion) >= 25) {
-            auto name = readString(from);
-            auto camStr = readString(from);
+        if (GET_PROTOCOL_MINOR(conn.protoVersion) >= 25) {
+            auto name = readString(conn.from);
+            auto camStr = readString(conn.from);
             auto refs = WorkerProto::Serialise<StorePathSet>::read(*store, rconn);
             bool repairBool;
-            from >> repairBool;
+            conn.from >> repairBool;
             auto repair = RepairFlag{repairBool};
 
             logger->startWork();
             auto pathInfo = [&]() {
                 // NB: FramedSource must be out of scope before logger->stopWork();
                 auto [contentAddressMethod, hashAlgo] = ContentAddressMethod::parseWithAlgo(camStr);
-                FramedSource source(from);
+                FramedSource source(conn.from);
                 FileSerialisationMethod dumpMethod;
                 switch (contentAddressMethod.getFileIngestionMethod()) {
                 case FileIngestionMethod::Flat:
@@ -439,7 +434,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
                 bool fixed;
                 uint8_t recursive;
                 std::string hashAlgoRaw;
-                from >> baseName >> fixed /* obsolete */ >> recursive >> hashAlgoRaw;
+                conn.from >> baseName >> fixed /* obsolete */ >> recursive >> hashAlgoRaw;
                 if (recursive > true)
                     throw Error("unsupported FileIngestionMethod with value of %i; you may need to upgrade nix-daemon", recursive);
                 method = recursive
@@ -459,11 +454,11 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
                    so why all this extra work? We still parse the NAR so
                    that we aren't sending arbitrary data to `saved`
                    unwittingly`, and we know when the NAR ends so we don't
-                   consume the rest of `from` and can't parse another
+                   consume the rest of `conn.from` and can't parse another
                    command. (We don't trust `addToStoreFromDump` to not
                    eagerly consume the entire stream it's given, past the
                    length of the Nar. */
-                TeeSource savedNARSource(from, saved);
+                TeeSource savedNARSource(conn.from, saved);
                 NullFileSystemObjectSink sink; /* just parse the NAR */
                 parseDump(sink, savedNARSource);
             });
@@ -472,20 +467,20 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
                 *dumpSource, baseName, FileSerialisationMethod::NixArchive, method, hashAlgo);
             logger->stopWork();
 
-            to << store->printStorePath(path);
+            conn.to << store->printStorePath(path);
         }
         break;
     }
 
     case WorkerProto::Op::AddMultipleToStore: {
         bool repair, dontCheckSigs;
-        from >> repair >> dontCheckSigs;
+        conn.from >> repair >> dontCheckSigs;
         if (!trusted && dontCheckSigs)
             dontCheckSigs = false;
 
         logger->startWork();
         {
-            FramedSource source(from);
+            FramedSource source(conn.from);
             store->addMultipleToStore(source,
                 RepairFlag{repair},
                 dontCheckSigs ? NoCheckSigs : CheckSigs);
@@ -495,8 +490,8 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     }
 
     case WorkerProto::Op::AddTextToStore: {
-        std::string suffix = readString(from);
-        std::string s = readString(from);
+        std::string suffix = readString(conn.from);
+        std::string s = readString(conn.from);
         auto refs = WorkerProto::Serialise<StorePathSet>::read(*store, rconn);
         logger->startWork();
         auto path = ({
@@ -504,37 +499,37 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
             store->addToStoreFromDump(source, suffix, FileSerialisationMethod::Flat, ContentAddressMethod::Raw::Text, HashAlgorithm::SHA256, refs, NoRepair);
         });
         logger->stopWork();
-        to << store->printStorePath(path);
+        conn.to << store->printStorePath(path);
         break;
     }
 
     case WorkerProto::Op::ExportPath: {
-        auto path = store->parseStorePath(readString(from));
-        readInt(from); // obsolete
+        auto path = store->parseStorePath(readString(conn.from));
+        readInt(conn.from); // obsolete
         logger->startWork();
-        TunnelSink sink(to);
+        TunnelSink sink(conn.to);
         store->exportPath(path, sink);
         logger->stopWork();
-        to << 1;
+        conn.to << 1;
         break;
     }
 
     case WorkerProto::Op::ImportPaths: {
         logger->startWork();
-        TunnelSource source(from, to);
+        TunnelSource source(conn.from, conn.to);
         auto paths = store->importPaths(source,
             trusted ? NoCheckSigs : CheckSigs);
         logger->stopWork();
         Strings paths2;
         for (auto & i : paths) paths2.push_back(store->printStorePath(i));
-        to << paths2;
+        conn.to << paths2;
         break;
     }
 
     case WorkerProto::Op::BuildPaths: {
         auto drvs = WorkerProto::Serialise<DerivedPaths>::read(*store, rconn);
         BuildMode mode = bmNormal;
-        if (GET_PROTOCOL_MINOR(clientVersion) >= 15) {
+        if (GET_PROTOCOL_MINOR(conn.protoVersion) >= 15) {
             mode = WorkerProto::Serialise<BuildMode>::read(*store, rconn);
 
             /* Repairing is not atomic, so disallowed for "untrusted"
@@ -552,7 +547,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         logger->startWork();
         store->buildPaths(drvs, mode);
         logger->stopWork();
-        to << 1;
+        conn.to << 1;
         break;
     }
 
@@ -578,7 +573,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     }
 
     case WorkerProto::Op::BuildDerivation: {
-        auto drvPath = store->parseStorePath(readString(from));
+        auto drvPath = store->parseStorePath(readString(conn.from));
         BasicDerivation drv;
         /*
          * Note: unlike wopEnsurePath, this operation reads a
@@ -589,7 +584,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
          * it cannot be trusted that its outPath was calculated
          * correctly.
          */
-        readDerivation(from, *store, drv, Derivation::nameFromPath(drvPath));
+        readDerivation(conn.from, *store, drv, Derivation::nameFromPath(drvPath));
         auto buildMode = WorkerProto::Serialise<BuildMode>::read(*store, rconn);
         logger->startWork();
 
@@ -655,20 +650,20 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     }
 
     case WorkerProto::Op::EnsurePath: {
-        auto path = store->parseStorePath(readString(from));
+        auto path = store->parseStorePath(readString(conn.from));
         logger->startWork();
         store->ensurePath(path);
         logger->stopWork();
-        to << 1;
+        conn.to << 1;
         break;
     }
 
     case WorkerProto::Op::AddTempRoot: {
-        auto path = store->parseStorePath(readString(from));
+        auto path = store->parseStorePath(readString(conn.from));
         logger->startWork();
         store->addTempRoot(path);
         logger->stopWork();
-        to << 1;
+        conn.to << 1;
         break;
     }
 
@@ -678,24 +673,24 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
                 "you are not privileged to create perm roots\n\n"
                 "hint: you can just do this client-side without special privileges, and probably want to do that instead.");
         auto storePath = WorkerProto::Serialise<StorePath>::read(*store, rconn);
-        Path gcRoot = absPath(readString(from));
+        Path gcRoot = absPath(readString(conn.from));
         logger->startWork();
         auto & localFSStore = require<LocalFSStore>(*store);
         localFSStore.addPermRoot(storePath, gcRoot);
         logger->stopWork();
-        to << gcRoot;
+        conn.to << gcRoot;
         break;
     }
 
     case WorkerProto::Op::AddIndirectRoot: {
-        Path path = absPath(readString(from));
+        Path path = absPath(readString(conn.from));
 
         logger->startWork();
         auto & indirectRootStore = require<IndirectRootStore>(*store);
         indirectRootStore.addIndirectRoot(path);
         logger->stopWork();
 
-        to << 1;
+        conn.to << 1;
         break;
     }
 
@@ -703,7 +698,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     case WorkerProto::Op::SyncWithGC: {
         logger->startWork();
         logger->stopWork();
-        to << 1;
+        conn.to << 1;
         break;
     }
 
@@ -717,24 +712,24 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         for (auto & i : roots)
             size += i.second.size();
 
-        to << size;
+        conn.to << size;
 
         for (auto & [target, links] : roots)
             for (auto & link : links)
-                to << link << store->printStorePath(target);
+                conn.to << link << store->printStorePath(target);
 
         break;
     }
 
     case WorkerProto::Op::CollectGarbage: {
         GCOptions options;
-        options.action = (GCOptions::GCAction) readInt(from);
+        options.action = (GCOptions::GCAction) readInt(conn.from);
         options.pathsToDelete = WorkerProto::Serialise<StorePathSet>::read(*store, rconn);
-        from >> options.ignoreLiveness >> options.maxFreed;
+        conn.from >> options.ignoreLiveness >> options.maxFreed;
         // obsolete fields
-        readInt(from);
-        readInt(from);
-        readInt(from);
+        readInt(conn.from);
+        readInt(conn.from);
+        readInt(conn.from);
 
         GCResults results;
 
@@ -745,7 +740,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         gcStore.collectGarbage(options, results);
         logger->stopWork();
 
-        to << results.paths << results.bytesFreed << 0 /* obsolete */;
+        conn.to << results.paths << results.bytesFreed << 0 /* obsolete */;
 
         break;
     }
@@ -754,24 +749,24 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
 
         ClientSettings clientSettings;
 
-        clientSettings.keepFailed = readInt(from);
-        clientSettings.keepGoing = readInt(from);
-        clientSettings.tryFallback = readInt(from);
-        clientSettings.verbosity = (Verbosity) readInt(from);
-        clientSettings.maxBuildJobs = readInt(from);
-        clientSettings.maxSilentTime = readInt(from);
-        readInt(from); // obsolete useBuildHook
-        clientSettings.verboseBuild = lvlError == (Verbosity) readInt(from);
-        readInt(from); // obsolete logType
-        readInt(from); // obsolete printBuildTrace
-        clientSettings.buildCores = readInt(from);
-        clientSettings.useSubstitutes = readInt(from);
+        clientSettings.keepFailed = readInt(conn.from);
+        clientSettings.keepGoing = readInt(conn.from);
+        clientSettings.tryFallback = readInt(conn.from);
+        clientSettings.verbosity = (Verbosity) readInt(conn.from);
+        clientSettings.maxBuildJobs = readInt(conn.from);
+        clientSettings.maxSilentTime = readInt(conn.from);
+        readInt(conn.from); // obsolete useBuildHook
+        clientSettings.verboseBuild = lvlError == (Verbosity) readInt(conn.from);
+        readInt(conn.from); // obsolete logType
+        readInt(conn.from); // obsolete printBuildTrace
+        clientSettings.buildCores = readInt(conn.from);
+        clientSettings.useSubstitutes = readInt(conn.from);
 
-        if (GET_PROTOCOL_MINOR(clientVersion) >= 12) {
-            unsigned int n = readInt(from);
+        if (GET_PROTOCOL_MINOR(conn.protoVersion) >= 12) {
+            unsigned int n = readInt(conn.from);
             for (unsigned int i = 0; i < n; i++) {
-                auto name = readString(from);
-                auto value = readString(from);
+                auto name = readString(conn.from);
+                auto value = readString(conn.from);
                 clientSettings.overrides.emplace(name, value);
             }
         }
@@ -788,20 +783,20 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     }
 
     case WorkerProto::Op::QuerySubstitutablePathInfo: {
-        auto path = store->parseStorePath(readString(from));
+        auto path = store->parseStorePath(readString(conn.from));
         logger->startWork();
         SubstitutablePathInfos infos;
         store->querySubstitutablePathInfos({{path, std::nullopt}}, infos);
         logger->stopWork();
         auto i = infos.find(path);
         if (i == infos.end())
-            to << 0;
+            conn.to << 0;
         else {
-            to << 1
+            conn.to << 1
                << (i->second.deriver ? store->printStorePath(*i->second.deriver) : "");
             WorkerProto::write(*store, wconn, i->second.references);
-            to << i->second.downloadSize
-               << i->second.narSize;
+            conn.to << i->second.downloadSize
+                    << i->second.narSize;
         }
         break;
     }
@@ -809,7 +804,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     case WorkerProto::Op::QuerySubstitutablePathInfos: {
         SubstitutablePathInfos infos;
         StorePathCAMap pathsMap = {};
-        if (GET_PROTOCOL_MINOR(clientVersion) < 22) {
+        if (GET_PROTOCOL_MINOR(conn.protoVersion) < 22) {
             auto paths = WorkerProto::Serialise<StorePathSet>::read(*store, rconn);
             for (auto & path : paths)
                 pathsMap.emplace(path, std::nullopt);
@@ -818,12 +813,12 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         logger->startWork();
         store->querySubstitutablePathInfos(pathsMap, infos);
         logger->stopWork();
-        to << infos.size();
+        conn.to << infos.size();
         for (auto & i : infos) {
-            to << store->printStorePath(i.first)
-               << (i.second.deriver ? store->printStorePath(*i.second.deriver) : "");
+            conn.to << store->printStorePath(i.first)
+                    << (i.second.deriver ? store->printStorePath(*i.second.deriver) : "");
             WorkerProto::write(*store, wconn, i.second.references);
-            to << i.second.downloadSize << i.second.narSize;
+            conn.to << i.second.downloadSize << i.second.narSize;
         }
         break;
     }
@@ -837,22 +832,22 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     }
 
     case WorkerProto::Op::QueryPathInfo: {
-        auto path = store->parseStorePath(readString(from));
+        auto path = store->parseStorePath(readString(conn.from));
         std::shared_ptr<const ValidPathInfo> info;
         logger->startWork();
         try {
             info = store->queryPathInfo(path);
         } catch (InvalidPath &) {
-            if (GET_PROTOCOL_MINOR(clientVersion) < 17) throw;
+            if (GET_PROTOCOL_MINOR(conn.protoVersion) < 17) throw;
         }
         logger->stopWork();
         if (info) {
-            if (GET_PROTOCOL_MINOR(clientVersion) >= 17)
-                to << 1;
+            if (GET_PROTOCOL_MINOR(conn.protoVersion) >= 17)
+                conn.to << 1;
             WorkerProto::write(*store, wconn, static_cast<const UnkeyedValidPathInfo &>(*info));
         } else {
-            assert(GET_PROTOCOL_MINOR(clientVersion) >= 17);
-            to << 0;
+            assert(GET_PROTOCOL_MINOR(conn.protoVersion) >= 17);
+            conn.to << 0;
         }
         break;
     }
@@ -861,61 +856,61 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         logger->startWork();
         store->optimiseStore();
         logger->stopWork();
-        to << 1;
+        conn.to << 1;
         break;
 
     case WorkerProto::Op::VerifyStore: {
         bool checkContents, repair;
-        from >> checkContents >> repair;
+        conn.from >> checkContents >> repair;
         logger->startWork();
         if (repair && !trusted)
             throw Error("you are not privileged to repair paths");
         bool errors = store->verifyStore(checkContents, (RepairFlag) repair);
         logger->stopWork();
-        to << errors;
+        conn.to << errors;
         break;
     }
 
     case WorkerProto::Op::AddSignatures: {
-        auto path = store->parseStorePath(readString(from));
-        StringSet sigs = readStrings<StringSet>(from);
+        auto path = store->parseStorePath(readString(conn.from));
+        StringSet sigs = readStrings<StringSet>(conn.from);
         logger->startWork();
         store->addSignatures(path, sigs);
         logger->stopWork();
-        to << 1;
+        conn.to << 1;
         break;
     }
 
     case WorkerProto::Op::NarFromPath: {
-        auto path = store->parseStorePath(readString(from));
+        auto path = store->parseStorePath(readString(conn.from));
         logger->startWork();
         logger->stopWork();
-        dumpPath(store->toRealPath(path), to);
+        dumpPath(store->toRealPath(path), conn.to);
         break;
     }
 
     case WorkerProto::Op::AddToStoreNar: {
         bool repair, dontCheckSigs;
-        auto path = store->parseStorePath(readString(from));
-        auto deriver = readString(from);
-        auto narHash = Hash::parseAny(readString(from), HashAlgorithm::SHA256);
+        auto path = store->parseStorePath(readString(conn.from));
+        auto deriver = readString(conn.from);
+        auto narHash = Hash::parseAny(readString(conn.from), HashAlgorithm::SHA256);
         ValidPathInfo info { path, narHash };
         if (deriver != "")
             info.deriver = store->parseStorePath(deriver);
         info.references = WorkerProto::Serialise<StorePathSet>::read(*store, rconn);
-        from >> info.registrationTime >> info.narSize >> info.ultimate;
-        info.sigs = readStrings<StringSet>(from);
-        info.ca = ContentAddress::parseOpt(readString(from));
-        from >> repair >> dontCheckSigs;
+        conn.from >> info.registrationTime >> info.narSize >> info.ultimate;
+        info.sigs = readStrings<StringSet>(conn.from);
+        info.ca = ContentAddress::parseOpt(readString(conn.from));
+        conn.from >> repair >> dontCheckSigs;
         if (!trusted && dontCheckSigs)
             dontCheckSigs = false;
         if (!trusted)
             info.ultimate = false;
 
-        if (GET_PROTOCOL_MINOR(clientVersion) >= 23) {
+        if (GET_PROTOCOL_MINOR(conn.protoVersion) >= 23) {
             logger->startWork();
             {
-                FramedSource source(from);
+                FramedSource source(conn.from);
                 store->addToStore(info, source, (RepairFlag) repair,
                     dontCheckSigs ? NoCheckSigs : CheckSigs);
             }
@@ -925,10 +920,10 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         else {
             std::unique_ptr<Source> source;
             StringSink saved;
-            if (GET_PROTOCOL_MINOR(clientVersion) >= 21)
-                source = std::make_unique<TunnelSource>(from, to);
+            if (GET_PROTOCOL_MINOR(conn.protoVersion) >= 21)
+                source = std::make_unique<TunnelSource>(conn.from, conn.to);
             else {
-                TeeSource tee { from, saved };
+                TeeSource tee { conn.from, saved };
                 NullFileSystemObjectSink ether;
                 parseDump(ether, tee);
                 source = std::make_unique<StringSource>(saved.s);
@@ -956,15 +951,15 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         WorkerProto::write(*store, wconn, willBuild);
         WorkerProto::write(*store, wconn, willSubstitute);
         WorkerProto::write(*store, wconn, unknown);
-        to << downloadSize << narSize;
+        conn.to << downloadSize << narSize;
         break;
     }
 
     case WorkerProto::Op::RegisterDrvOutput: {
         logger->startWork();
-        if (GET_PROTOCOL_MINOR(clientVersion) < 31) {
-            auto outputId = DrvOutput::parse(readString(from));
-            auto outputPath = StorePath(readString(from));
+        if (GET_PROTOCOL_MINOR(conn.protoVersion) < 31) {
+            auto outputId = DrvOutput::parse(readString(conn.from));
+            auto outputPath = StorePath(readString(conn.from));
             store->registerDrvOutput(Realisation{
                 .id = outputId, .outPath = outputPath});
         } else {
@@ -977,10 +972,10 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
 
     case WorkerProto::Op::QueryRealisation: {
         logger->startWork();
-        auto outputId = DrvOutput::parse(readString(from));
+        auto outputId = DrvOutput::parse(readString(conn.from));
         auto info = store->queryRealisation(outputId);
         logger->stopWork();
-        if (GET_PROTOCOL_MINOR(clientVersion) < 31) {
+        if (GET_PROTOCOL_MINOR(conn.protoVersion) < 31) {
             std::set<StorePath> outPaths;
             if (info) outPaths.insert(info->outPath);
             WorkerProto::write(*store, wconn, outPaths);
@@ -993,19 +988,19 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     }
 
     case WorkerProto::Op::AddBuildLog: {
-        StorePath path{readString(from)};
+        StorePath path{readString(conn.from)};
         logger->startWork();
         if (!trusted)
             throw Error("you are not privileged to add logs");
         auto & logStore = require<LogStore>(*store);
         {
-            FramedSource source(from);
+            FramedSource source(conn.from);
             StringSink sink;
             source.drainInto(sink);
             logStore.addBuildLog(path, sink.s);
         }
         logger->stopWork();
-        to << 1;
+        conn.to << 1;
         break;
     }
 
@@ -1090,7 +1085,7 @@ void processConnection(
             debug("performing daemon worker op: %d", op);
 
             try {
-                performOp(tunnelLogger, store, trusted, recursive, clientVersion, conn.from, conn.to, op);
+                performOp(tunnelLogger, store, trusted, recursive, conn, op);
             } catch (Error & e) {
                 /* If we're not in a state where we can send replies, then
                    something went wrong processing the input of the