Merge pull request #22328 from giuseppe/drop-ReadMappingsProc

rootless: drop function ReadMappingsProc

libpod/info_linux.go

@@ -18,6 +18,8 @@ import (
 	"github.com/containers/common/pkg/version"
 	"github.com/containers/podman/v5/libpod/define"
 	"github.com/containers/podman/v5/pkg/rootless"
+	"github.com/containers/podman/v5/pkg/util"
+	"github.com/containers/storage/pkg/unshare"
 	"github.com/opencontainers/selinux/go-selinux"
 	"github.com/sirupsen/logrus"
 )
@@ -91,17 +93,13 @@ func (r *Runtime) setPlatformHostInfo(info *define.HostInfo) error {
 	}
 
 	if rootless.IsRootless() {
-		uidmappings, err := rootless.ReadMappingsProc("/proc/self/uid_map")
+		uidmappings, gidmappings, err := unshare.GetHostIDMappings("")
 		if err != nil {
-			return fmt.Errorf("reading uid mappings: %w", err)
+			return fmt.Errorf("reading id mappings: %w", err)
-		}
-		gidmappings, err := rootless.ReadMappingsProc("/proc/self/gid_map")
-		if err != nil {
-			return fmt.Errorf("reading gid mappings: %w", err)
 		}
 		idmappings := define.IDMappings{
-			GIDMap: gidmappings,
+			GIDMap: util.RuntimeSpecToIDtools(gidmappings),
-			UIDMap: uidmappings,
+			UIDMap: util.RuntimeSpecToIDtools(uidmappings),
 		}
 		info.IDMappings = idmappings
 	}

pkg/rootless/rootless_freebsd.go

@@ -57,11 +57,6 @@ func GetConfiguredMappings(quiet bool) ([]idtools.IDMap, []idtools.IDMap, error)
 	return nil, nil, errors.New("this function is not supported on this os")
 }
 
-// ReadMappingsProc returns the uid_map and gid_map
-func ReadMappingsProc(path string) ([]idtools.IDMap, error) {
-	return nil, nil
-}
-
 // IsFdInherited checks whether the fd is opened and valid to use
 func IsFdInherited(fd int) bool {
 	return int(C.is_fd_inherited(C.int(fd))) > 0

pkg/rootless/rootless_linux.go

@@ -3,11 +3,9 @@
 package rootless
 
 import (
-	"bufio"
 	"bytes"
 	"errors"
 	"fmt"
-	"io"
 	"os"
 	"os/exec"
 	gosignal "os/signal"
@@ -22,6 +20,7 @@ import (
 	"github.com/containers/storage/pkg/idtools"
 	pmount "github.com/containers/storage/pkg/mount"
 	"github.com/containers/storage/pkg/unshare"
+	"github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/sirupsen/logrus"
 	"github.com/syndtr/gocapability/capability"
 	"golang.org/x/sys/unix"
@@ -514,40 +513,9 @@ func TryJoinFromFilePaths(pausePidPath string, needNewNamespace bool, paths []st
 	return false, 0, fmt.Errorf("could not find any running process: %w", unix.ESRCH)
 }
 
-// ReadMappingsProc parses and returns the ID mappings at the specified path.
+func matches(id int, configuredIDs []idtools.IDMap, currentIDs []specs.LinuxIDMapping) bool {
-func ReadMappingsProc(path string) ([]idtools.IDMap, error) {
-	file, err := os.Open(path)
-	if err != nil {
-		return nil, err
-	}
-	defer file.Close()
-
-	mappings := []idtools.IDMap{}
-
-	buf := bufio.NewReader(file)
-	for {
-		line, _, err := buf.ReadLine()
-		if err != nil {
-			if err == io.EOF {
-				return mappings, nil
-			}
-			return nil, fmt.Errorf("cannot read line from %s: %w", path, err)
-		}
-		if line == nil {
-			return mappings, nil
-		}
-
-		containerID, hostID, size := 0, 0, 0
-		if _, err := fmt.Sscanf(string(line), "%d %d %d", &containerID, &hostID, &size); err != nil {
-			return nil, fmt.Errorf("cannot parse %s: %w", string(line), err)
-		}
-		mappings = append(mappings, idtools.IDMap{ContainerID: containerID, HostID: hostID, Size: size})
-	}
-}
-
-func matches(id int, configuredIDs []idtools.IDMap, currentIDs []idtools.IDMap) bool {
 	// The first mapping is the host user, handle it separately.
-	if currentIDs[0].HostID != id || currentIDs[0].Size != 1 {
+	if currentIDs[0].HostID != uint32(id) || currentIDs[0].Size != 1 {
 		return false
 	}
 
@@ -558,10 +526,10 @@ func matches(id int, configuredIDs []idtools.IDMap, currentIDs []idtools.IDMap)
 
 	// It is fine to iterate sequentially as both slices are sorted.
 	for i := range currentIDs {
-		if currentIDs[i].HostID != configuredIDs[i].HostID {
+		if currentIDs[i].HostID != uint32(configuredIDs[i].HostID) {
 			return false
 		}
-		if currentIDs[i].Size != configuredIDs[i].Size {
+		if currentIDs[i].Size != uint32(configuredIDs[i].Size) {
 			return false
 		}
 	}
@@ -581,7 +549,7 @@ func ConfigurationMatches() (bool, error) {
 		return false, err
 	}
 
-	currentUIDs, err := ReadMappingsProc("/proc/self/uid_map")
+	currentUIDs, currentGIDs, err := unshare.GetHostIDMappings("")
 	if err != nil {
 		return false, err
 	}
@@ -590,11 +558,6 @@ func ConfigurationMatches() (bool, error) {
 		return false, err
 	}
 
-	currentGIDs, err := ReadMappingsProc("/proc/self/gid_map")
-	if err != nil {
-		return false, err
-	}
-
 	return matches(GetRootlessGID(), gids, currentGIDs), nil
 }
 

pkg/rootless/rootless_unsupported.go

@@ -60,11 +60,6 @@ func GetConfiguredMappings(quiet bool) ([]idtools.IDMap, []idtools.IDMap, error)
 	return nil, nil, errors.New("this function is not supported on this os")
 }
 
-// ReadMappingsProc returns the uid_map and gid_map
-func ReadMappingsProc(path string) ([]idtools.IDMap, error) {
-	return nil, nil
-}
-
 // IsFdInherited checks whether the fd is opened and valid to use
 func IsFdInherited(fd int) bool {
 	return false

pkg/util/utils.go

@@ -26,6 +26,7 @@ import (
 	"github.com/containers/podman/v5/pkg/signal"
 	"github.com/containers/storage/pkg/directory"
 	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/unshare"
 	stypes "github.com/containers/storage/types"
 	securejoin "github.com/cyphar/filepath-securejoin"
 	ruser "github.com/moby/sys/user"
@@ -221,16 +222,12 @@ func GetKeepIDMapping(opts *namespaces.KeepIDUserNsOptions) (*stypes.IDMappingOp
 			HostUIDMapping: false,
 			HostGIDMapping: false,
 		}
-		uids, err := rootless.ReadMappingsProc("/proc/self/uid_map")
+		uids, gids, err := unshare.GetHostIDMappings("")
 		if err != nil {
 			return nil, 0, 0, err
 		}
-		gids, err := rootless.ReadMappingsProc("/proc/self/gid_map")
+		options.UIDMap = RuntimeSpecToIDtools(uids)
-		if err != nil {
+		options.GIDMap = RuntimeSpecToIDtools(gids)
-			return nil, 0, 0, err
-		}
-		options.UIDMap = uids
-		options.GIDMap = gids
 
 		uid, gid := 0, 0
 		if opts.UID != nil {