From 1531d7e790a7e1350638ae1e76ed8ad5b5d7b56c Mon Sep 17 00:00:00 2001
From: Clayton Craft <clayton@craftyguy.net>
Date: Fri, 17 Feb 2023 12:56:40 -0800
Subject: [PATCH] filelist/modules: add new implementation

---
 internal/filelist/modules/modules.go      | 195 ++++++++++++++++++++++
 internal/filelist/modules/modules_test.go |  82 +++++++++
 2 files changed, 277 insertions(+)
 create mode 100644 internal/filelist/modules/modules.go
 create mode 100644 internal/filelist/modules/modules_test.go

diff --git a/internal/filelist/modules/modules.go b/internal/filelist/modules/modules.go
new file mode 100644
index 0000000..fd7b4c1
--- /dev/null
+++ b/internal/filelist/modules/modules.go
@@ -0,0 +1,195 @@
+package modules
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"gitlab.com/postmarketOS/postmarketos-mkinitfs/internal/misc"
+)
+
+type Modules struct {
+	modules []string
+}
+
+// New returns a new HookScripts that will use the given path to provide a list
+// of script files.
+func New(modules []string) *Modules {
+	return &Modules{
+		modules: modules,
+	}
+}
+
+func (m *Modules) List() ([]string, error) {
+	kernVer, err := misc.GetKernelVersion()
+	if err != nil {
+		return nil, err
+	}
+
+	files := []string{}
+
+	modDir := filepath.Join("/lib/modules", kernVer)
+	if !misc.Exists(modDir) {
+		// dir /lib/modules/<kernel> if kernel built without module support, so just print a message
+		log.Printf("-- kernel module directory not found: %q, not including modules", modDir)
+		return files, nil
+	}
+
+	// modules.* required by modprobe
+	modprobeFiles, _ := filepath.Glob(filepath.Join(modDir, "modules.*"))
+	files = append(files, modprobeFiles...)
+
+	// module name (without extension), or directory (trailing slash is important! globs OK)
+	requiredModules := []string{
+		"loop",
+		"dm-crypt",
+		"kernel/fs/overlayfs/",
+		"kernel/crypto/",
+		"kernel/arch/*/crypto/",
+	}
+
+	for _, item := range requiredModules {
+		dir, file := filepath.Split(item)
+		if file == "" {
+			// item is a directory
+			dir = filepath.Join(modDir, dir)
+			dirs, _ := filepath.Glob(dir)
+			for _, d := range dirs {
+				if filelist, err := getModulesInDir(d); err != nil {
+					return nil, fmt.Errorf("getInitfsModules: unable to get modules dir %q: %w", d, err)
+				} else {
+					files = append(files, filelist...)
+				}
+			}
+		} else if dir == "" {
+			// item is a module name
+			if filelist, err := getModule(file, modDir); err != nil {
+				return nil, fmt.Errorf("getInitfsModules: unable to get module %q: %w", file, err)
+			} else {
+				files = append(files, filelist...)
+			}
+		} else {
+			log.Printf("Unknown module entry: %q", item)
+		}
+	}
+
+	// deviceinfo modules
+	for _, module := range m.modules {
+		if filelist, err := getModule(module, modDir); err != nil {
+			return nil, fmt.Errorf("getInitfsModules: unable to get modules from deviceinfo: %w", err)
+		} else {
+			files = append(files, filelist...)
+		}
+	}
+
+	// /etc/postmarketos-mkinitfs/modules/*.modules
+	initfsModFiles, _ := filepath.Glob("/etc/postmarketos-mkinitfs/modules/*.modules")
+	for _, modFile := range initfsModFiles {
+		f, err := os.Open(modFile)
+		if err != nil {
+			return nil, fmt.Errorf("getInitfsModules: unable to open mkinitfs modules file %q: %w", modFile, err)
+		}
+		defer f.Close()
+		s := bufio.NewScanner(f)
+		for s.Scan() {
+			if filelist, err := getModule(s.Text(), modDir); err != nil {
+				return nil, fmt.Errorf("getInitfsModules: unable to get module file %q: %w", s.Text(), err)
+			} else {
+				files = append(files, filelist...)
+			}
+		}
+	}
+
+	return files, nil
+}
+
+func getModulesInDir(modPath string) (files []string, err error) {
+	err = filepath.Walk(modPath, func(path string, f os.FileInfo, err error) error {
+		// TODO: need to support more extensions?
+		if filepath.Ext(path) != ".ko" && filepath.Ext(path) != ".xz" {
+			return nil
+		}
+		files = append(files, path)
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return
+}
+
+// Given a module name, e.g. 'dwc_wdt', resolve the full path to the module
+// file and all of its dependencies.
+// Note: it's not necessarily fatal if the module is not found, since it may
+// have been built into the kernel
+// TODO: look for it in modules.builtin, and make it fatal if it can't be found
+// anywhere
+func getModule(modName string, modDir string) (files []string, err error) {
+
+	modDep := filepath.Join(modDir, "modules.dep")
+	if !misc.Exists(modDep) {
+		return nil, fmt.Errorf("kernel module.dep not found: %s", modDir)
+	}
+
+	fd, err := os.Open(modDep)
+	if err != nil {
+		return nil, fmt.Errorf("unable to open modules.dep: %w", err)
+	}
+	defer fd.Close()
+
+	deps, err := getModuleDeps(modName, fd)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, dep := range deps {
+		p := filepath.Join(modDir, dep)
+		if !misc.Exists(p) {
+			return nil, fmt.Errorf("tried to include a module that doesn't exist in the modules directory (%s): %s", modDir, p)
+		}
+		files = append(files, p)
+	}
+
+	return
+}
+
+// Get the canonicalized name for the module as represented in the given modules.dep io.reader
+func getModuleDeps(modName string, modulesDep io.Reader) ([]string, error) {
+	var deps []string
+
+	// split the module name on - and/or _, build a regex for matching
+	splitRe := regexp.MustCompile("[-_]+")
+	modNameReStr := splitRe.ReplaceAllString(modName, "[-_]+")
+	re := regexp.MustCompile("^" + modNameReStr + "$")
+
+	s := bufio.NewScanner(modulesDep)
+	for s.Scan() {
+		fields := strings.Fields(s.Text())
+		if len(fields) == 0 {
+			continue
+		}
+		fields[0] = strings.TrimSuffix(fields[0], ":")
+
+		found := re.FindAll([]byte(filepath.Base(stripExts(fields[0]))), -1)
+		if len(found) > 0 {
+			deps = append(deps, fields...)
+			break
+		}
+	}
+	if err := s.Err(); err != nil {
+		log.Print("Unable to get module + dependencies: ", modName)
+		return deps, err
+	}
+
+	return deps, nil
+}
+
+func stripExts(file string) string {
+	return strings.Split(file, ".")[0]
+}
diff --git a/internal/filelist/modules/modules_test.go b/internal/filelist/modules/modules_test.go
new file mode 100644
index 0000000..c88be43
--- /dev/null
+++ b/internal/filelist/modules/modules_test.go
@@ -0,0 +1,82 @@
+// Copyright 2023 Clayton Craft <clayton@craftyguy.net>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package modules
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestStripExts(t *testing.T) {
+	tables := []struct {
+		in       string
+		expected string
+	}{
+		{"/foo/bar/bazz.tar", "/foo/bar/bazz"},
+		{"file.tar.gz.xz.zip", "file"},
+		{"another_file", "another_file"},
+		{"a.b.c.d.e.f.g.h.i", "a"},
+		{"virtio_blk.ko", "virtio_blk"},
+	}
+	for _, table := range tables {
+		out := stripExts(table.in)
+		if out != table.expected {
+			t.Errorf("Expected: %q, got: %q", table.expected, out)
+		}
+	}
+}
+
+var testModuleDep string = `
+kernel/sound/soc/codecs/snd-soc-msm8916-digital.ko:
+kernel/net/sched/act_ipt.ko.xz: kernel/net/netfilter/x_tables.ko.xz
+kernel/drivers/watchdog/watchdog.ko.xz:
+kernel/drivers/usb/serial/ir-usb.ko.xz: kernel/drivers/usb/serial/usbserial.ko.xz
+kernel/drivers/gpu/drm/scheduler/gpu-sched.ko.xz:
+kernel/drivers/hid/hid-alps.ko.xz:
+kernel/net/netfilter/xt_u32.ko.xz: kernel/net/netfilter/x_tables.ko.xz
+kernel/net/netfilter/xt_sctp.ko.xz: kernel/net/netfilter/x_tables.ko.xz
+kernel/drivers/hwmon/gl518sm.ko.xz:
+kernel/drivers/watchdog/dw_wdt.ko.xz: kernel/drivers/watchdog/watchdog.ko.xz
+kernel/net/bluetooth/hidp/hidp.ko.xz: kernel/net/bluetooth/bluetooth.ko.xz kernel/net/rfkill/rfkill.ko.xz kernel/crypto/ecdh_generic.ko.xz kernel/crypto/ecc.ko.xz
+kernel/fs/nls/nls_iso8859-1.ko.xz:
+kernel/net/vmw_vsock/vmw_vsock_virtio_transport.ko.xz: kernel/net/vmw_vsock/vmw_vsock_virtio_transport_common.ko.xz kernel/drivers/virtio/virtio.ko.xz kernel/drivers/virtio/virtio_ring.ko.xz kernel/net/vmw_vsock/vsock.ko.xz
+kernel/drivers/gpu/drm/panfrost/panfrost.ko.xz: kernel/drivers/gpu/drm/scheduler/gpu-sched.ko.xz
+kernel/drivers/gpu/drm/msm/msm.ko: kernel/drivers/gpu/drm/drm_kms_helper.ko
+`
+
+func TestGetModuleDeps(t *testing.T) {
+	tables := []struct {
+		in       string
+		expected []string
+	}{
+		{"nls-iso8859-1", []string{"kernel/fs/nls/nls_iso8859-1.ko.xz"}},
+		{"gpu_sched", []string{"kernel/drivers/gpu/drm/scheduler/gpu-sched.ko.xz"}},
+		{"dw-wdt", []string{"kernel/drivers/watchdog/dw_wdt.ko.xz",
+			"kernel/drivers/watchdog/watchdog.ko.xz"}},
+		{"gl518sm", []string{"kernel/drivers/hwmon/gl518sm.ko.xz"}},
+		{"msm", []string{"kernel/drivers/gpu/drm/msm/msm.ko",
+			"kernel/drivers/gpu/drm/drm_kms_helper.ko"}},
+	}
+	for _, table := range tables {
+		out, err := getModuleDeps(table.in, strings.NewReader(testModuleDep))
+		if err != nil {
+			t.Errorf("unexpected error with input: %q, error: %q", table.expected, err)
+		}
+		if !stringSlicesEqual(out, table.expected) {
+			t.Errorf("Expected: %q, got: %q", table.expected, out)
+		}
+	}
+}
+
+func stringSlicesEqual(a []string, b []string) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i, v := range a {
+		if v != b[i] {
+			return false
+		}
+	}
+	return true
+}