nfs: add a portmap client

Summary:
The portmap protocol allows for service discovery and registration against the
per-host rpcbind daemon. An NFS server will need to register against it to be
mountable.

The portmap_util binary is here for testing purposes and will not be used in
EdenFS.

This code was written by wez.

Reviewed By: kmancini

Differential Revision: D25986694

fbshipit-source-id: 1eee7238fdf70c8c4937e685da91ad08d46befe4

eden/fs/nfs/portmap/PortmapClient.cpp

@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This software may be used and distributed according to the terms of the
+ * GNU General Public License version 2.
+ */
+
+#include "eden/fs/nfs/portmap/PortmapClient.h"
+#include <common/network/NetworkUtil.h>
+#include <folly/Exception.h>
+#include <folly/SocketAddress.h>
+#include <folly/String.h>
+#include <folly/logging/xlog.h>
+
+using folly::IOBuf;
+using folly::IOBufQueue;
+using folly::SocketAddress;
+
+namespace facebook::eden {
+
+namespace {
+constexpr uint32_t kPortmapPortNumber = 111;
+constexpr uint32_t kPortmapProgNumber = 100000;
+/*
+ * Ideally we should use version 3 and 4, as that appears to have better
+ * support for ipv6. For now, and since the goal is to only support a loopback
+ * NFS, let's use version 2 and ipv4.
+ */
+constexpr uint32_t kPortmapVersionNumber = 2;
+constexpr uint32_t kPortmapSet = 1;
+constexpr uint32_t kPortmapUnSet = 2;
+constexpr uint32_t kPortmapGetPort = 3;
+} // namespace
+
+EDEN_XDR_SERDE_IMPL(PortmapMapping, prog, vers, prot, port);
+
+PortmapClient::PortmapClient()
+    : client_(SocketAddress(
+          network::NetworkUtil::getLocalIPv4(),
+          kPortmapPortNumber)) {
+#ifdef __APPLE__
+  {
+    // Connect to the portmap "tickler" socket.
+    // This causes launchd to spawn `rpcbind` and bring up the portmap service.
+    auto addr = SocketAddress::makeFromPath("/var/run/portmap.socket");
+    sockaddr_storage stg;
+    auto len = addr.getAddress(&stg);
+    tickler_ = folly::netops::socket(addr.getFamily(), SOCK_STREAM, 0);
+    folly::checkUnixError(
+        folly::netops::connect(tickler_, (sockaddr*)&stg, len),
+        "connect to ",
+        addr.getPath());
+  }
+#endif
+
+  client_.connect();
+}
+
+bool PortmapClient::unsetMapping(PortmapMapping map) {
+  return client_.call<bool, PortmapMapping>(
+      kPortmapProgNumber, kPortmapVersionNumber, kPortmapUnSet, map);
+}
+
+bool PortmapClient::setMapping(PortmapMapping map) {
+  return client_.call<bool, PortmapMapping>(
+      kPortmapProgNumber, kPortmapVersionNumber, kPortmapSet, map);
+}
+
+uint32_t PortmapClient::getPort(PortmapMapping map) {
+  return client_.call<uint32_t, PortmapMapping>(
+      kPortmapProgNumber, kPortmapVersionNumber, kPortmapGetPort, map);
+}
+
+} // namespace facebook::eden

eden/fs/nfs/portmap/PortmapClient.h

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This software may be used and distributed according to the terms of the
+ * GNU General Public License version 2.
+ */
+
+#pragma once
+#include <folly/net/NetworkSocket.h>
+#include "eden/fs/nfs/rpc/Rpc.h"
+#include "eden/fs/nfs/rpc/StreamClient.h"
+
+namespace facebook::eden {
+
+struct PortmapMapping {
+  uint32_t prog;
+  uint32_t vers;
+  uint32_t prot;
+  uint32_t port;
+
+  static constexpr uint32_t kProtoTcp = 6;
+  static constexpr uint32_t kProtoUdp = 17;
+
+  bool operator==(const PortmapMapping&) const;
+};
+EDEN_XDR_SERDE_DECL(PortmapMapping);
+
+class PortmapClient {
+ public:
+  bool setMapping(PortmapMapping map);
+  bool unsetMapping(PortmapMapping map);
+  uint32_t getPort(PortmapMapping map);
+
+  PortmapClient();
+
+ private:
+#ifdef __APPLE__
+  folly::NetworkSocket tickler_;
+#endif
+  StreamClient client_;
+};
+
+} // namespace facebook::eden

eden/fs/nfs/portmap/PortmapUtil.cpp

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This software may be used and distributed according to the terms of the
+ * GNU General Public License version 2.
+ */
+
+#include <folly/SocketAddress.h>
+#include <folly/init/Init.h>
+#include <folly/logging/Init.h>
+#include <folly/logging/xlog.h>
+#include "eden/fs/nfs/portmap/PortmapClient.h"
+
+using namespace facebook::eden;
+
+FOLLY_INIT_LOGGING_CONFIG("eden=INFO");
+
+int main(int argc, char** argv) {
+  folly::init(&argc, &argv);
+
+  PortmapClient client;
+
+  auto port =
+      client.getPort(PortmapMapping{100003, 3, PortmapMapping::kProtoTcp, 0});
+
+  XLOG(INFO) << "Got port: " << port;
+
+  // Try to set a bogus port for NFS.
+  // This will fail if there is already an NFS daemon running
+  XLOG(INFO) << "Set mapping: "
+             << client.setMapping(
+                    PortmapMapping{100003, 3, PortmapMapping::kProtoTcp, 123});
+
+  // Read back the current port
+  auto newPort =
+      client.getPort(PortmapMapping{100003, 3, PortmapMapping::kProtoTcp, 0});
+
+  XLOG(INFO) << "Got new port: " << newPort;
+
+  return 0;
+}