permcheck: imp code

This commit is contained in:
Eugene Burkov 2024-11-29 14:28:17 +03:00
parent 3a5b6aced9
commit 7dfbeda179
4 changed files with 142 additions and 104 deletions

View File

@ -4,15 +4,9 @@ package permcheck
import (
"context"
"fmt"
"io/fs"
"log/slog"
"os"
"path/filepath"
"github.com/AdguardTeam/AdGuardHome/internal/aghos"
"github.com/AdguardTeam/golibs/errors"
"github.com/AdguardTeam/golibs/logutil/slogutil"
)
// check is the Unix-specific implementation of [Check].
@ -27,26 +21,13 @@ func check(
) {
dirLoggger, fileLogger := l.With("type", typeDir), l.With("type", typeFile)
checkDir(ctx, dirLoggger, workDir)
checkFile(ctx, fileLogger, confFilePath)
// TODO(a.garipov): Put all paths in one place and remove this duplication.
checkDir(ctx, dirLoggger, dataDir)
checkDir(ctx, dirLoggger, filepath.Join(dataDir, "filters"))
checkFile(ctx, fileLogger, filepath.Join(dataDir, "sessions.db"))
checkFile(ctx, fileLogger, filepath.Join(dataDir, "leases.json"))
if dataDir != querylogDir {
checkDir(ctx, dirLoggger, querylogDir)
for _, ent := range entities(workDir, dataDir, statsDir, querylogDir, confFilePath) {
if ent.Value {
checkDir(ctx, dirLoggger, ent.Key)
} else {
checkFile(ctx, fileLogger, ent.Key)
}
checkFile(ctx, fileLogger, filepath.Join(querylogDir, "querylog.json"))
checkFile(ctx, fileLogger, filepath.Join(querylogDir, "querylog.json.1"))
if dataDir != statsDir {
checkDir(ctx, dirLoggger, statsDir)
}
checkFile(ctx, fileLogger, filepath.Join(statsDir, "stats.db"))
}
// checkDir checks the permissions of a single directory. The results are
@ -60,29 +41,3 @@ func checkDir(ctx context.Context, l *slog.Logger, dirPath string) {
func checkFile(ctx context.Context, l *slog.Logger, filePath string) {
checkPath(ctx, l, filePath, aghos.DefaultPermFile)
}
// checkPath checks the permissions of a single filesystem entity. The results
// are logged at the appropriate level.
func checkPath(ctx context.Context, l *slog.Logger, fpath string, want fs.FileMode) {
l = l.With("path", fpath)
s, err := os.Stat(fpath)
if err != nil {
lvl := slog.LevelError
if errors.Is(err, os.ErrNotExist) {
lvl = slog.LevelDebug
}
l.Log(ctx, lvl, "checking permissions", slogutil.KeyError, err)
return
}
// TODO(a.garipov): Add a more fine-grained check and result reporting.
perm := s.Mode().Perm()
if perm == want {
return
}
permOct, wantOct := fmt.Sprintf("%#o", perm), fmt.Sprintf("%#o", want)
l.WarnContext(ctx, "found unexpected permissions", "perm", permOct, "want", wantOct)
}

View File

@ -4,11 +4,8 @@ package permcheck
import (
"context"
"fmt"
"io/fs"
"log/slog"
"os"
"path/filepath"
"github.com/AdguardTeam/AdGuardHome/internal/aghos"
"github.com/AdguardTeam/golibs/errors"
@ -47,26 +44,13 @@ func migrate(
) {
dirLoggger, fileLogger := l.With("type", typeDir), l.With("type", typeFile)
chmodDir(ctx, dirLoggger, workDir)
chmodFile(ctx, fileLogger, confFilePath)
// TODO(a.garipov): Put all paths in one place and remove this duplication.
chmodDir(ctx, dirLoggger, dataDir)
chmodDir(ctx, dirLoggger, filepath.Join(dataDir, "filters"))
chmodFile(ctx, fileLogger, filepath.Join(dataDir, "sessions.db"))
chmodFile(ctx, fileLogger, filepath.Join(dataDir, "leases.json"))
if dataDir != querylogDir {
chmodDir(ctx, dirLoggger, querylogDir)
for _, ent := range entities(workDir, dataDir, statsDir, querylogDir, confFilePath) {
if ent.Value {
chmodDir(ctx, dirLoggger, ent.Key)
} else {
chmodFile(ctx, fileLogger, ent.Key)
}
chmodFile(ctx, fileLogger, filepath.Join(querylogDir, "querylog.json"))
chmodFile(ctx, fileLogger, filepath.Join(querylogDir, "querylog.json.1"))
if dataDir != statsDir {
chmodDir(ctx, dirLoggger, statsDir)
}
chmodFile(ctx, fileLogger, filepath.Join(statsDir, "stats.db"))
}
// chmodDir changes the permissions of a single directory. The results are
@ -80,28 +64,3 @@ func chmodDir(ctx context.Context, l *slog.Logger, dirPath string) {
func chmodFile(ctx context.Context, l *slog.Logger, filePath string) {
chmodPath(ctx, l, filePath, aghos.DefaultPermFile)
}
// chmodPath changes the permissions of a single filesystem entity. The results
// are logged at the appropriate level.
func chmodPath(ctx context.Context, l *slog.Logger, fpath string, fm fs.FileMode) {
var lvl slog.Level
var msg string
args := []any{"path", fpath}
switch err := os.Chmod(fpath, fm); {
case err == nil:
lvl = slog.LevelInfo
msg = "changed permissions"
case errors.Is(err, os.ErrNotExist):
lvl = slog.LevelDebug
msg = "checking permissions"
args = append(args, slogutil.KeyError, err)
default:
lvl = slog.LevelError
msg = "cannot change permissions; this can leave your system vulnerable, see " +
"https://adguard-dns.io/kb/adguard-home/running-securely/#os-service-concerns"
args = append(args, "target_perm", fmt.Sprintf("%#o", fm), slogutil.KeyError, err)
}
l.Log(ctx, lvl, msg, args...)
}

View File

@ -57,7 +57,10 @@ func needsMigration(ctx context.Context, l *slog.Logger, workDir, _ string) (ok
// migrate is the Windows-specific implementation of [Migrate].
//
// It
// It sets the owner to administrators and adds a full control access control
// entry for the account. It also removes all non-administrator access control
// entries, and keeps deny access control entries. For any created or modified
// entry it sets the propagation flags to be inherited by child objects.
func migrate(ctx context.Context, logger *slog.Logger, workDir, _, _, _, _ string) {
l := logger.With("type", typeDir, "path", workDir)
@ -80,7 +83,7 @@ func migrate(ctx context.Context, logger *slog.Logger, workDir, _, _, _, _ strin
// TODO(e.burkov): Check for duplicates?
var accessEntries []windows.EXPLICIT_ACCESS
var useACL bool
var setACL bool
// Iterate over the access control entries in DACL to determine if its
// migration is needed.
err = rangeACEs(dacl, func(
@ -94,18 +97,18 @@ func migrate(ctx context.Context, logger *slog.Logger, workDir, _, _, _, _ strin
// the access restrictions, which shouldn't be lost.
l.InfoContext(ctx, "migrating deny access control entry", "sid", sid)
accessEntries = append(accessEntries, newDenyExplicitAccess(sid, mask))
useACL = true
setACL = true
case !sid.IsWellKnown(windows.WinBuiltinAdministratorsSid):
// Remove non-administrator ACEs, since such accounts should not
// have any access rights.
l.InfoContext(ctx, "removing access control entry", "sid", sid)
useACL = true
setACL = true
default:
// Administrators should have full control. Don't add a new entry
// here since it will be added later in case there are other
// required entries.
l.InfoContext(ctx, "migrating access control entry", "sid", sid, "mask", mask)
useACL = useACL || mask&fullControlMask != fullControlMask
setACL = setACL || mask&fullControlMask != fullControlMask
}
return true
@ -116,7 +119,7 @@ func migrate(ctx context.Context, logger *slog.Logger, workDir, _, _, _, _ strin
return
}
if useACL {
if setACL {
accessEntries = append(accessEntries, newFullExplicitAccess(owner))
}

View File

@ -0,0 +1,121 @@
//go:build unix
package permcheck
import (
"context"
"fmt"
"io/fs"
"log/slog"
"os"
"path/filepath"
"github.com/AdguardTeam/golibs/container"
"github.com/AdguardTeam/golibs/errors"
"github.com/AdguardTeam/golibs/logutil/slogutil"
)
// entity is a filesystem entity with a path and a flag indicating whether it is
// a directory.
type entity = container.KeyValue[string, bool]
// entities returns a list of filesystem entities that need to be ranged over.
func entities(workDir, dataDir, statsDir, querylogDir, confFilePath string) (ents []entity) {
ents = container.KeyValues[string, bool]{{
Key: workDir,
Value: true,
}, {
Key: confFilePath,
Value: false,
}, {
Key: dataDir,
Value: true,
}, {
Key: filepath.Join(dataDir, "filters"),
Value: true,
}, {
Key: filepath.Join(dataDir, "sessions.db"),
Value: false,
}, {
Key: filepath.Join(dataDir, "leases.json"),
Value: false,
}}
if dataDir != querylogDir {
ents = append(ents, entity{
Key: querylogDir,
Value: true,
})
}
ents = append(ents, []entity{{
Key: filepath.Join(querylogDir, "querylog.json"),
Value: false,
}, {
Key: filepath.Join(querylogDir, "querylog.json.1"),
Value: false,
}}...)
if dataDir != statsDir {
ents = append(ents, entity{
Key: statsDir,
Value: true,
})
}
ents = append(ents, entity{
Key: filepath.Join(statsDir, "stats.db"),
})
return ents
}
// checkPath checks the permissions of a single filesystem entity. The results
// are logged at the appropriate level.
func checkPath(ctx context.Context, l *slog.Logger, entPath string, want fs.FileMode) {
l = l.With("path", entPath)
s, err := os.Stat(entPath)
if err != nil {
lvl := slog.LevelError
if errors.Is(err, os.ErrNotExist) {
lvl = slog.LevelDebug
}
l.Log(ctx, lvl, "checking permissions", slogutil.KeyError, err)
return
}
// TODO(a.garipov): Add a more fine-grained check and result reporting.
perm := s.Mode().Perm()
if perm == want {
return
}
permOct, wantOct := fmt.Sprintf("%#o", perm), fmt.Sprintf("%#o", want)
l.WarnContext(ctx, "found unexpected permissions", "perm", permOct, "want", wantOct)
}
// chmodPath changes the permissions of a single filesystem entity. The results
// are logged at the appropriate level.
func chmodPath(ctx context.Context, l *slog.Logger, entPath string, fm fs.FileMode) {
var lvl slog.Level
var msg string
args := []any{"path", entPath}
switch err := os.Chmod(entPath, fm); {
case err == nil:
lvl = slog.LevelInfo
msg = "changed permissions"
case errors.Is(err, os.ErrNotExist):
lvl = slog.LevelDebug
msg = "checking permissions"
args = append(args, slogutil.KeyError, err)
default:
lvl = slog.LevelError
msg = "cannot change permissions; this can leave your system vulnerable, see " +
"https://adguard-dns.io/kb/adguard-home/running-securely/#os-service-concerns"
args = append(args, "target_perm", fmt.Sprintf("%#o", fm), slogutil.KeyError, err)
}
l.Log(ctx, lvl, msg, args...)
}