util.{hh,cc}: Split out unix-domain-socket.{hh,cc}

Change-Id: I3f9a628e0f8998b6146f5caa8ae9842361a66b8b

10 files changed, 142 insertions, 114 deletions

diff --git a/src/libstore/build/local-derivation-goal.cc b/src/libstore/build/local-derivation-goal.cc
index d385ffb34..fd871e8a4 100644
--- a/src/libstore/build/local-derivation-goal.cc
+++ b/src/libstore/build/local-derivation-goal.cc
@@ -15,6 +15,7 @@
 #include "personality.hh"
 #include "namespaces.hh"
 #include "child.hh"
+#include "unix-domain-socket.hh"
 
 #include <regex>
 #include <queue>
diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc
index 60d88f3b2..722452b8d 100644
--- a/src/libstore/gc.cc
+++ b/src/libstore/gc.cc
@@ -4,6 +4,7 @@
 #include "processes.hh"
 #include "signals.hh"
 #include "finally.hh"
+#include "unix-domain-socket.hh"
 
 #include <functional>
 #include <queue>
diff --git a/src/libstore/uds-remote-store.cc b/src/libstore/uds-remote-store.cc
index 99589f8b2..226cdf717 100644
--- a/src/libstore/uds-remote-store.cc
+++ b/src/libstore/uds-remote-store.cc
@@ -1,4 +1,5 @@
 #include "uds-remote-store.hh"
+#include "unix-domain-socket.hh"
 #include "worker-protocol.hh"
 
 #include <sys/types.h>
diff --git a/src/libutil/file-descriptor.hh b/src/libutil/file-descriptor.hh
index 68324b9d9..f59baa7a0 100644
--- a/src/libutil/file-descriptor.hh
+++ b/src/libutil/file-descriptor.hh
@@ -77,13 +77,4 @@ void closeOnExec(int fd);
 
 MakeError(EndOfFile, Error);
 
-/**
- * Create a Unix domain socket.
- */
-AutoCloseFD createUnixDomainSocket();
-
-/**
- * Create a Unix domain socket in listen mode.
- */
-AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode);
 }
diff --git a/src/libutil/meson.build b/src/libutil/meson.build
index ef4270066..73c520116 100644
--- a/src/libutil/meson.build
+++ b/src/libutil/meson.build
@@ -35,6 +35,7 @@ libutil_sources = files(
   'tarfile.cc',
   'terminal.cc',
   'thread-pool.cc',
+  'unix-domain-socket.cc',
   'url.cc',
   'url-name.cc',
   'util.cc',
@@ -102,6 +103,7 @@ libutil_headers = files(
   'thread-pool.hh',
   'topo-sort.hh',
   'types.hh',
+  'unix-domain-socket.hh',
   'url-parts.hh',
   'url-name.hh',
   'url.hh',
diff --git a/src/libutil/unix-domain-socket.cc b/src/libutil/unix-domain-socket.cc
new file mode 100644
index 000000000..9fefcbe1c
--- /dev/null
+++ b/src/libutil/unix-domain-socket.cc
@@ -0,0 +1,105 @@
+#include "file-system.hh"
+#include "processes.hh"
+#include "unix-domain-socket.hh"
+#include "util.hh"
+
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+namespace nix {
+
+AutoCloseFD createUnixDomainSocket()
+{
+    AutoCloseFD fdSocket{socket(PF_UNIX, SOCK_STREAM
+        #ifdef SOCK_CLOEXEC
+        | SOCK_CLOEXEC
+        #endif
+        , 0)};
+    if (!fdSocket)
+        throw SysError("cannot create Unix domain socket");
+    closeOnExec(fdSocket.get());
+    return fdSocket;
+}
+
+
+AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode)
+{
+    auto fdSocket = nix::createUnixDomainSocket();
+
+    bind(fdSocket.get(), path);
+
+    chmodPath(path.c_str(), mode);
+
+    if (listen(fdSocket.get(), 100) == -1)
+        throw SysError("cannot listen on socket '%1%'", path);
+
+    return fdSocket;
+}
+
+static void bindConnectProcHelper(
+    std::string_view operationName, auto && operation,
+    int fd, const std::string & path)
+{
+    struct sockaddr_un addr;
+    addr.sun_family = AF_UNIX;
+
+    // Casting between types like these legacy C library interfaces
+    // require is forbidden in C++. To maintain backwards
+    // compatibility, the implementation of the bind/connect functions
+    // contains some hints to the compiler that allow for this
+    // special case.
+    auto * psaddr = reinterpret_cast<struct sockaddr *>(&addr);
+
+    if (path.size() + 1 >= sizeof(addr.sun_path)) {
+        Pipe pipe;
+        pipe.create();
+        Pid pid = startProcess([&] {
+            try {
+                pipe.readSide.close();
+                Path dir = dirOf(path);
+                if (chdir(dir.c_str()) == -1)
+                    throw SysError("chdir to '%s' failed", dir);
+                std::string base(baseNameOf(path));
+                if (base.size() + 1 >= sizeof(addr.sun_path))
+                    throw Error("socket path '%s' is too long", base);
+                memcpy(addr.sun_path, base.c_str(), base.size() + 1);
+                if (operation(fd, psaddr, sizeof(addr)) == -1)
+                    throw SysError("cannot %s to socket at '%s'", operationName, path);
+                writeFull(pipe.writeSide.get(), "0\n");
+            } catch (SysError & e) {
+                writeFull(pipe.writeSide.get(), fmt("%d\n", e.errNo));
+            } catch (...) {
+                writeFull(pipe.writeSide.get(), "-1\n");
+            }
+        });
+        pipe.writeSide.close();
+        auto errNo = string2Int<int>(chomp(drainFD(pipe.readSide.get())));
+        if (!errNo || *errNo == -1)
+            throw Error("cannot %s to socket at '%s'", operationName, path);
+        else if (*errNo > 0) {
+            errno = *errNo;
+            throw SysError("cannot %s to socket at '%s'", operationName, path);
+        }
+    } else {
+        memcpy(addr.sun_path, path.c_str(), path.size() + 1);
+        if (operation(fd, psaddr, sizeof(addr)) == -1)
+            throw SysError("cannot %s to socket at '%s'", operationName, path);
+    }
+}
+
+
+void bind(int fd, const std::string & path)
+{
+    unlink(path.c_str());
+
+    bindConnectProcHelper("bind", ::bind, fd, path);
+}
+
+
+void connect(int fd, const std::string & path)
+{
+    bindConnectProcHelper("connect", ::connect, fd, path);
+}
+
+}
diff --git a/src/libutil/unix-domain-socket.hh b/src/libutil/unix-domain-socket.hh
new file mode 100644
index 000000000..692ad2627
--- /dev/null
+++ b/src/libutil/unix-domain-socket.hh
@@ -0,0 +1,31 @@
+#pragma once
+///@file
+
+#include "file-descriptor.hh"
+#include "types.hh"
+
+#include <unistd.h>
+
+namespace nix {
+
+/**
+ * Create a Unix domain socket.
+ */
+AutoCloseFD createUnixDomainSocket();
+
+/**
+ * Create a Unix domain socket in listen mode.
+ */
+AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode);
+
+/**
+ * Bind a Unix domain socket to a path.
+ */
+void bind(int fd, const std::string & path);
+
+/**
+ * Connect to a Unix domain socket.
+ */
+void connect(int fd, const std::string & path);
+
+}
diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index aff26e32b..f580ef038 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -459,100 +459,6 @@ void unshareFilesystem()
 #endif
 }
 
-AutoCloseFD createUnixDomainSocket()
-{
-    AutoCloseFD fdSocket{socket(PF_UNIX, SOCK_STREAM
-        #ifdef SOCK_CLOEXEC
-        | SOCK_CLOEXEC
-        #endif
-        , 0)};
-    if (!fdSocket)
-        throw SysError("cannot create Unix domain socket");
-    closeOnExec(fdSocket.get());
-    return fdSocket;
-}
-
-
-AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode)
-{
-    auto fdSocket = nix::createUnixDomainSocket();
-
-    bind(fdSocket.get(), path);
-
-    chmodPath(path.c_str(), mode);
-
-    if (listen(fdSocket.get(), 100) == -1)
-        throw SysError("cannot listen on socket '%1%'", path);
-
-    return fdSocket;
-}
-
-
-static void bindConnectProcHelper(
-    std::string_view operationName, auto && operation,
-    int fd, const std::string & path)
-{
-    struct sockaddr_un addr;
-    addr.sun_family = AF_UNIX;
-
-    // Casting between types like these legacy C library interfaces
-    // require is forbidden in C++. To maintain backwards
-    // compatibility, the implementation of the bind/connect functions
-    // contains some hints to the compiler that allow for this
-    // special case.
-    auto * psaddr = reinterpret_cast<struct sockaddr *>(&addr);
-
-    if (path.size() + 1 >= sizeof(addr.sun_path)) {
-        Pipe pipe;
-        pipe.create();
-        Pid pid = startProcess([&] {
-            try {
-                pipe.readSide.close();
-                Path dir = dirOf(path);
-                if (chdir(dir.c_str()) == -1)
-                    throw SysError("chdir to '%s' failed", dir);
-                std::string base(baseNameOf(path));
-                if (base.size() + 1 >= sizeof(addr.sun_path))
-                    throw Error("socket path '%s' is too long", base);
-                memcpy(addr.sun_path, base.c_str(), base.size() + 1);
-                if (operation(fd, psaddr, sizeof(addr)) == -1)
-                    throw SysError("cannot %s to socket at '%s'", operationName, path);
-                writeFull(pipe.writeSide.get(), "0\n");
-            } catch (SysError & e) {
-                writeFull(pipe.writeSide.get(), fmt("%d\n", e.errNo));
-            } catch (...) {
-                writeFull(pipe.writeSide.get(), "-1\n");
-            }
-        });
-        pipe.writeSide.close();
-        auto errNo = string2Int<int>(chomp(drainFD(pipe.readSide.get())));
-        if (!errNo || *errNo == -1)
-            throw Error("cannot %s to socket at '%s'", operationName, path);
-        else if (*errNo > 0) {
-            errno = *errNo;
-            throw SysError("cannot %s to socket at '%s'", operationName, path);
-        }
-    } else {
-        memcpy(addr.sun_path, path.c_str(), path.size() + 1);
-        if (operation(fd, psaddr, sizeof(addr)) == -1)
-            throw SysError("cannot %s to socket at '%s'", operationName, path);
-    }
-}
-
-
-void bind(int fd, const std::string & path)
-{
-    unlink(path.c_str());
-
-    bindConnectProcHelper("bind", ::bind, fd, path);
-}
-
-
-void connect(int fd, const std::string & path)
-{
-    bindConnectProcHelper("connect", ::connect, fd, path);
-}
-
 
 std::string showBytes(uint64_t bytes)
 {
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index e704cd709..216693635 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -407,17 +407,6 @@ struct MaintainCount
 
 
 /**
- * Bind a Unix domain socket to a path.
- */
-void bind(int fd, const std::string & path);
-
-/**
- * Connect to a Unix domain socket.
- */
-void connect(int fd, const std::string & path);
-
-
-/**
  * A Rust/Python-like enumerate() iterator adapter.
  *
  * Borrowed from http://reedbeta.com/blog/python-like-enumerate-in-cpp17.
diff --git a/src/nix/daemon.cc b/src/nix/daemon.cc
index 9d4afb6d9..113e23bd1 100644
--- a/src/nix/daemon.cc
+++ b/src/nix/daemon.cc
@@ -14,6 +14,7 @@
 #include "legacy.hh"
 #include "signals.hh"
 #include "daemon.hh"
+#include "unix-domain-socket.hh"
 
 #include <algorithm>
 #include <climits>