5 files changed, 128 insertions, 0 deletions
diff --git a/third_party/nix/src/CMakeLists.txt b/third_party/nix/src/CMakeLists.txt
index 37ff3b54af94..3f30b1672562 100644
--- a/third_party/nix/src/CMakeLists.txt
+++ b/third_party/nix/src/CMakeLists.txt
@@ -5,6 +5,7 @@
 # this location and this setup mimics that (with the exception of the
 # various Nix libraries).
 
+add_subdirectory(proto)
 add_subdirectory(libutil)
 add_subdirectory(libstore)
 add_subdirectory(libmain)
diff --git a/third_party/nix/src/libstore/CMakeLists.txt b/third_party/nix/src/libstore/CMakeLists.txt
index 4bc7b8fd5db2..705be9574d2f 100644
--- a/third_party/nix/src/libstore/CMakeLists.txt
+++ b/third_party/nix/src/libstore/CMakeLists.txt
@@ -88,6 +88,7 @@ target_sources(nixstore
 )
 
 target_link_libraries(nixstore
+  nixproto
   nixutil
 
   BZip2::BZip2
diff --git a/third_party/nix/src/nix-daemon/nix-daemon.cc b/third_party/nix/src/nix-daemon/nix-daemon.cc
index b2161f8584db..c7967307c1ba 100644
--- a/third_party/nix/src/nix-daemon/nix-daemon.cc
+++ b/third_party/nix/src/nix-daemon/nix-daemon.cc
@@ -27,6 +27,7 @@
 #include "libutil/serialise.hh"
 #include "libutil/util.hh"
 #include "nix/legacy.hh"
+#include "libproto/worker.pb.h"
 
 using namespace nix;
 
diff --git a/third_party/nix/src/proto/CMakeLists.txt b/third_party/nix/src/proto/CMakeLists.txt
new file mode 100644
index 000000000000..726ca8742f86
--- /dev/null
+++ b/third_party/nix/src/proto/CMakeLists.txt
@@ -0,0 +1,37 @@
+# -*- mode: cmake; -*-
+#
+# The proto generation happens outside of CMake and the path to the
+# generated files is passed in via the environment variable
+# $NIX_PROTO_SRCS.
+#
+# This configuration defines a library target that compiles these
+# sources and makes the headers available.
+
+add_library(nixproto SHARED)
+set_property(TARGET nixproto PROPERTY CXX_STANDARD 17)
+
+set(HEADER_FILES
+  $ENV{NIX_PROTO_SRCS}/libproto/worker.grpc.pb.h
+  $ENV{NIX_PROTO_SRCS}/libproto/worker.pb.h
+)
+
+target_sources(nixproto
+  PUBLIC
+    ${HEADER_FILES}
+
+  PRIVATE
+    $ENV{NIX_PROTO_SRCS}/libproto/worker.grpc.pb.cc
+    $ENV{NIX_PROTO_SRCS}/libproto/worker.pb.cc
+)
+
+target_link_libraries(nixproto
+  gRPC::grpc++_reflection
+  protobuf::libprotobuf
+)
+
+target_include_directories(nixproto
+  INTERFACE $ENV{NIX_PROTO_SRCS}
+)
+
+INSTALL(FILES ${HEADER_FILES} DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/nix/libproto)
+INSTALL(TARGETS nixproto DESTINATION ${CMAKE_INSTALL_LIBDIR})
diff --git a/third_party/nix/src/proto/worker.proto b/third_party/nix/src/proto/worker.proto
new file mode 100644
index 000000000000..8db1a9e808d2
--- /dev/null
+++ b/third_party/nix/src/proto/worker.proto
@@ -0,0 +1,88 @@
+syntax = "proto3";
+
+package nix.proto;
+
+// Service representing a worker used for building and interfacing
+// with the Nix store.
+service Worker {
+  // Validates whether the supplied path is a valid store path.
+  rpc IsValidPath (IsValidPathRequest) returns (IsValidPathResponse);
+
+  // Checks whether any substitutes exist for the given path.
+  rpc HasSubstitutes (HasSubstitutesRequest) returns (HasSubstitutesResponse);
+
+  // Query referrers for a given path.
+  rpc QueryReferrers (QueryReferrersRequest) returns (QueryReferrersResponse);
+
+  // Add a NAR (I think?) to the store. The first stream request
+  // should be a message indicating metadata, the rest should be file
+  // chunks.
+  rpc AddToStore (stream AddToStoreRequest) returns (AddToStoreResponse);
+
+  // Adds the supplied string to the store, as a text file.
+  rpc AddTextToStore (AddTextToStoreRequest) returns (AddTextToStoreResponse);
+}
+
+enum HashType {
+  MD5 = 0; // TODO(tazjin): still needed?
+  SHA1 = 1;
+  SHA256 = 2;
+  SHA512 = 3;
+}
+
+message IsValidPathRequest {
+  string path = 1;
+}
+
+message IsValidPathResponse {
+  bool is_valid = 1;
+}
+
+message HasSubstitutesRequest {
+  string path = 1;
+}
+
+message HasSubstitutesResponse {
+  bool has_substitutes = 1;
+}
+
+message QueryReferrersRequest {
+  string path = 1;
+}
+
+message QueryReferrersResponse {
+  repeated string paths = 1;
+}
+
+message AddToStoreRequest {
+  message Metadata {
+    bool fixed = 1;
+    bool recursive = 2; // TODO(tazjin): what is this? "obsolete" comment?
+    HashType hash_type = 3;
+    string base_name = 4;
+  }
+
+  message Chunk {
+    bytes content = 1;
+    bool final = 2;
+  }
+
+  oneof add_oneof {
+    Metadata meta = 1;
+    Chunk chunk = 2;
+  }
+}
+
+message AddToStoreResponse {
+  string path = 1;
+}
+
+message AddTextToStoreRequest {
+  string name = 1;
+  string content = 2;
+  repeated string references = 3;
+}
+
+message AddTextToStoreResponse {
+  string path = 1;
+}