github.com/powerman/golang-tools@v0.1.11-0.20220410185822-5ad214d8d803/internal/lsp/lsprpc/autostart_posix.go (about)

     1  // Copyright 2020 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
     6  // +build darwin dragonfly freebsd linux netbsd openbsd solaris
     7  
     8  package lsprpc
     9  
    10  import (
    11  	"crypto/sha256"
    12  	"errors"
    13  	"fmt"
    14  	"log"
    15  	"os"
    16  	"os/user"
    17  	"path/filepath"
    18  	"strconv"
    19  	"syscall"
    20  
    21  	exec "golang.org/x/sys/execabs"
    22  
    23  	"golang.org/x/xerrors"
    24  )
    25  
    26  func init() {
    27  	daemonize = daemonizePosix
    28  	autoNetworkAddress = autoNetworkAddressPosix
    29  	verifyRemoteOwnership = verifyRemoteOwnershipPosix
    30  }
    31  
    32  func daemonizePosix(cmd *exec.Cmd) {
    33  	cmd.SysProcAttr = &syscall.SysProcAttr{
    34  		Setsid: true,
    35  	}
    36  }
    37  
    38  // autoNetworkAddress resolves an id on the 'auto' pseduo-network to a
    39  // real network and address. On unix, this uses unix domain sockets.
    40  func autoNetworkAddressPosix(goplsPath, id string) (network string, address string) {
    41  	// Especially when doing local development or testing, it's important that
    42  	// the remote gopls instance we connect to is running the same binary as our
    43  	// forwarder. So we encode a short hash of the binary path into the daemon
    44  	// socket name. If possible, we also include the buildid in this hash, to
    45  	// account for long-running processes where the binary has been subsequently
    46  	// rebuilt.
    47  	h := sha256.New()
    48  	cmd := exec.Command("go", "tool", "buildid", goplsPath)
    49  	cmd.Stdout = h
    50  	var pathHash []byte
    51  	if err := cmd.Run(); err == nil {
    52  		pathHash = h.Sum(nil)
    53  	} else {
    54  		log.Printf("error getting current buildid: %v", err)
    55  		sum := sha256.Sum256([]byte(goplsPath))
    56  		pathHash = sum[:]
    57  	}
    58  	shortHash := fmt.Sprintf("%x", pathHash)[:6]
    59  	user := os.Getenv("USER")
    60  	if user == "" {
    61  		user = "shared"
    62  	}
    63  	basename := filepath.Base(goplsPath)
    64  	idComponent := ""
    65  	if id != "" {
    66  		idComponent = "-" + id
    67  	}
    68  	runtimeDir := os.TempDir()
    69  	if xdg := os.Getenv("XDG_RUNTIME_DIR"); xdg != "" {
    70  		runtimeDir = xdg
    71  	}
    72  	return "unix", filepath.Join(runtimeDir, fmt.Sprintf("%s-%s-daemon.%s%s", basename, shortHash, user, idComponent))
    73  }
    74  
    75  func verifyRemoteOwnershipPosix(network, address string) (bool, error) {
    76  	if network != "unix" {
    77  		return true, nil
    78  	}
    79  	fi, err := os.Stat(address)
    80  	if err != nil {
    81  		if os.IsNotExist(err) {
    82  			return true, nil
    83  		}
    84  		return false, xerrors.Errorf("checking socket owner: %w", err)
    85  	}
    86  	stat, ok := fi.Sys().(*syscall.Stat_t)
    87  	if !ok {
    88  		return false, errors.New("fi.Sys() is not a Stat_t")
    89  	}
    90  	user, err := user.Current()
    91  	if err != nil {
    92  		return false, xerrors.Errorf("checking current user: %w", err)
    93  	}
    94  	uid, err := strconv.ParseUint(user.Uid, 10, 32)
    95  	if err != nil {
    96  		return false, xerrors.Errorf("parsing current UID: %w", err)
    97  	}
    98  	return stat.Uid == uint32(uid), nil
    99  }