From 200f56315e7f104aa08c02fb6a218e7b6ededaad Mon Sep 17 00:00:00 2001
From: Kir Kolyshkin <kolyshkin@gmail.com>
Date: Fri, 3 Jan 2025 18:14:02 -0800
Subject: [PATCH] libct/devices: move config to libct/cg/devices/config

Currently, libcontainer/devices contains two things:

1. Device-related configuration data structures and accompanying
   methods. Those are used by runc itself, mostly by libct/cgroups.

2. A few functions (HostDevices, DeviceFromPath, GetDevices).
   Those are not used by runc directly, but have some external users
   (cri-o, microsoft/hcsshim), and they also have a few forks
   (containerd/pkg/oci, podman/pkg/util).

This commit moves (1) to a new separate package, config (under
libcontainer/cgroups/devices), adding a backward-compatible aliases
(marked as deprecated so we will be able to remove those later).

Alas it's not possible to move this to libcontainer/cgroups directly
because some IDs (Type, Rule, Permissions) are too generic, and renaming
them (to DeviceType, DeviceRule, DevicePermissions) will break backward
compatibility (mostly due to Rule being embedded into Device).

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
---
 .../devices/config}/device.go                 |  2 +-
 .../cgroups/devices/config/mknod_unix.go      | 14 +++++++++++++
 libcontainer/devices/device_deprecated.go     | 20 +++++++++++++++++++
 libcontainer/devices/device_unix.go           |  7 -------
 4 files changed, 35 insertions(+), 8 deletions(-)
 rename libcontainer/{devices => cgroups/devices/config}/device.go (99%)
 create mode 100644 libcontainer/cgroups/devices/config/mknod_unix.go
 create mode 100644 libcontainer/devices/device_deprecated.go

diff --git a/libcontainer/devices/device.go b/libcontainer/cgroups/devices/config/device.go
similarity index 99%
rename from libcontainer/devices/device.go
rename to libcontainer/cgroups/devices/config/device.go
index c2c2b3bb7..05ad3ef8c 100644
--- a/libcontainer/devices/device.go
+++ b/libcontainer/cgroups/devices/config/device.go
@@ -1,4 +1,4 @@
-package devices
+package config
 
 import (
 	"fmt"
diff --git a/libcontainer/cgroups/devices/config/mknod_unix.go b/libcontainer/cgroups/devices/config/mknod_unix.go
new file mode 100644
index 000000000..98cdc6e2f
--- /dev/null
+++ b/libcontainer/cgroups/devices/config/mknod_unix.go
@@ -0,0 +1,14 @@
+package config
+
+import (
+	"errors"
+
+	"golang.org/x/sys/unix"
+)
+
+func mkDev(d *Rule) (uint64, error) {
+	if d.Major == Wildcard || d.Minor == Wildcard {
+		return 0, errors.New("cannot mkdev() device with wildcards")
+	}
+	return unix.Mkdev(uint32(d.Major), uint32(d.Minor)), nil
+}
diff --git a/libcontainer/devices/device_deprecated.go b/libcontainer/devices/device_deprecated.go
new file mode 100644
index 000000000..6e960a424
--- /dev/null
+++ b/libcontainer/devices/device_deprecated.go
@@ -0,0 +1,20 @@
+package devices
+
+import "github.com/opencontainers/runc/libcontainer/cgroups/devices/config"
+
+// Deprecated: use [github.com/opencontainers/runc/libcontainer/cgroups/devices/config].
+const (
+	Wildcard       = config.Wildcard
+	WildcardDevice = config.WildcardDevice
+	BlockDevice    = config.BlockDevice
+	CharDevice     = config.CharDevice
+	FifoDevice     = config.FifoDevice
+)
+
+// Deprecated: use [github.com/opencontainers/runc/libcontainer/cgroups/devices/config].
+type (
+	Device      = config.Device
+	Permissions = config.Permissions
+	Type        = config.Type
+	Rule        = config.Rule
+)
diff --git a/libcontainer/devices/device_unix.go b/libcontainer/devices/device_unix.go
index d00775f51..c533eb1c6 100644
--- a/libcontainer/devices/device_unix.go
+++ b/libcontainer/devices/device_unix.go
@@ -19,13 +19,6 @@ var (
 	osReadDir = os.ReadDir
 )
 
-func mkDev(d *Rule) (uint64, error) {
-	if d.Major == Wildcard || d.Minor == Wildcard {
-		return 0, errors.New("cannot mkdev() device with wildcards")
-	}
-	return unix.Mkdev(uint32(d.Major), uint32(d.Minor)), nil
-}
-
 // DeviceFromPath takes the path to a device and its cgroup_permissions (which
 // cannot be easily queried) to look up the information about a linux device
 // and returns that information as a Device struct.