bastion 0.53.2

client-go/coders_linux.go

@@ -0,0 +1,63 @@
+//go:build linux
+
+package main
+
+import (
+	"net"
+	"os"
+	"path/filepath"
+	"strconv"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+// coderSocketOwner: (owner uid, true) when p is a unix socket itself — Lstat,
+// so a symlink is seen as a symlink and never followed.
+func coderSocketOwner(p string) (int, bool) {
+	fi, err := os.Lstat(p)
+	if err != nil || fi.Mode()&os.ModeSocket == 0 {
+		return -1, false
+	}
+	st, ok := fi.Sys().(*syscall.Stat_t)
+	if !ok {
+		return -1, false
+	}
+	return int(st.Uid), true
+}
+
+// coderFileOwner is the uid that owns fi (an Lstat result).
+func coderFileOwner(fi os.FileInfo) (int, bool) {
+	st, ok := fi.Sys().(*syscall.Stat_t)
+	if !ok {
+		return -1, false
+	}
+	return int(st.Uid), true
+}
+
+// coderReadMemInfo is MemTotal and MemAvailable in bytes (ops_memory_linux.go).
+func coderReadMemInfo() (total, avail uint64, ok bool) { return opMemInfo() }
+
+// coderReadPSIMem is the machine's memory "full avg10" (coderParsePSIFull);
+// ok is false on a kernel without pressure stall information.
+func coderReadPSIMem() (float64, bool) {
+	b, err := os.ReadFile(filepath.Join(coderProcFS, "pressure", "memory"))
+	if err != nil {
+		return 0, false
+	}
+	return coderParsePSIFull(string(b))
+}
+
+// coderListenUnix listens on dir/name. A run directory's path can be longer
+// than a unix socket address holds (108 bytes: the config dir, coders/runs/,
+// a 63-character run id, egress/egress.sock), so the bind goes through
+// /proc/self/fd/<dir fd>/name, which the kernel resolves to the directory
+// already opened — short, whatever the real path is.
+func coderListenUnix(dir, name string) (net.Listener, error) {
+	fd, err := unix.Open(dir, unix.O_PATH|unix.O_DIRECTORY|unix.O_CLOEXEC, 0)
+	if err != nil {
+		return nil, err
+	}
+	defer unix.Close(fd)
+	return net.Listen("unix", "/proc/self/fd/"+strconv.Itoa(fd)+"/"+name)
+}