Files
podman/libpod/container_internal_freebsd.go
Doug Rabson f06869168e libpod: Use O_CLOEXEC for descriptors returned by (*Container).openDirectory
Since mountStorage and createNetNS run in parallel, the directory file
descriptors used by mountStorage were (rarely) propagated to the CNI
plugins. On FreeBSD, the CNI bridge plugin needs to make changes to the
network jail. This fails if there are any descriptors to open directories
to protect against host directories being visible to the jail's chroot.

Adding O_CLOEXEC to the unix.Open call in openDirectory ensures that these
descriptors are not visible to podman's child processes.

[NO NEW TESTS NEEDED]

Signed-off-by: Doug Rabson <dfr@rabson.org>
2022-11-26 13:55:18 +00:00

309 lines
7.5 KiB
Go

//go:build freebsd
// +build freebsd
package libpod
import (
"fmt"
"os"
"strings"
"sync"
"syscall"
"time"
"github.com/containers/common/libnetwork/types"
"github.com/containers/podman/v4/pkg/rootless"
spec "github.com/opencontainers/runtime-spec/specs-go"
"github.com/opencontainers/runtime-tools/generate"
"github.com/sirupsen/logrus"
"golang.org/x/sys/unix"
)
var (
bindOptions = []string{}
)
func (c *Container) mountSHM(shmOptions string) error {
return nil
}
func (c *Container) unmountSHM(path string) error {
return nil
}
// prepare mounts the container and sets up other required resources like net
// namespaces
func (c *Container) prepare() error {
var (
wg sync.WaitGroup
ctrNS *jailNetNS
networkStatus map[string]types.StatusBlock
createNetNSErr, mountStorageErr error
mountPoint string
tmpStateLock sync.Mutex
)
wg.Add(2)
go func() {
defer wg.Done()
// Set up network namespace if not already set up
noNetNS := c.state.NetNS == nil
if c.config.CreateNetNS && noNetNS && !c.config.PostConfigureNetNS {
ctrNS, networkStatus, createNetNSErr = c.runtime.createNetNS(c)
if createNetNSErr != nil {
return
}
tmpStateLock.Lock()
defer tmpStateLock.Unlock()
// Assign NetNS attributes to container
c.state.NetNS = ctrNS
c.state.NetworkStatus = networkStatus
}
}()
// Mount storage if not mounted
go func() {
defer wg.Done()
mountPoint, mountStorageErr = c.mountStorage()
if mountStorageErr != nil {
return
}
tmpStateLock.Lock()
defer tmpStateLock.Unlock()
// Finish up mountStorage
c.state.Mounted = true
c.state.Mountpoint = mountPoint
logrus.Debugf("Created root filesystem for container %s at %s", c.ID(), c.state.Mountpoint)
}()
wg.Wait()
var createErr error
if createNetNSErr != nil {
createErr = createNetNSErr
}
if mountStorageErr != nil {
if createErr != nil {
logrus.Errorf("Preparing container %s: %v", c.ID(), createErr)
}
createErr = mountStorageErr
}
// Only trigger storage cleanup if mountStorage was successful.
// Otherwise, we may mess up mount counters.
if createErr != nil {
if mountStorageErr == nil {
if err := c.cleanupStorage(); err != nil {
// createErr is guaranteed non-nil, so print
// unconditionally
logrus.Errorf("Preparing container %s: %v", c.ID(), createErr)
createErr = fmt.Errorf("unmounting storage for container %s after network create failure: %w", c.ID(), err)
}
}
// It's OK to unconditionally trigger network cleanup. If the network
// isn't ready it will do nothing.
if err := c.cleanupNetwork(); err != nil {
logrus.Errorf("Preparing container %s: %v", c.ID(), createErr)
createErr = fmt.Errorf("cleaning up container %s network after setup failure: %w", c.ID(), err)
}
return createErr
}
// Save changes to container state
if err := c.save(); err != nil {
return err
}
return nil
}
// cleanupNetwork unmounts and cleans up the container's network
func (c *Container) cleanupNetwork() error {
if c.config.NetNsCtr != "" {
return nil
}
netDisabled, err := c.NetworkDisabled()
if err != nil {
return err
}
if netDisabled {
return nil
}
// Stop the container's network namespace (if it has one)
if err := c.runtime.teardownNetNS(c); err != nil {
logrus.Errorf("Unable to cleanup network for container %s: %q", c.ID(), err)
}
if c.valid {
return c.save()
}
return nil
}
// reloadNetwork reloads the network for the given container, recreating
// firewall rules.
func (c *Container) reloadNetwork() error {
result, err := c.runtime.reloadContainerNetwork(c)
if err != nil {
return err
}
c.state.NetworkStatus = result
return c.save()
}
// Add an existing container's network jail
func (c *Container) addNetworkContainer(g *generate.Generator, ctr string) error {
nsCtr, err := c.runtime.state.Container(ctr)
c.runtime.state.UpdateContainer(nsCtr)
if err != nil {
return fmt.Errorf("retrieving dependency %s of container %s from state: %w", ctr, c.ID(), err)
}
g.AddAnnotation("org.freebsd.parentJail", nsCtr.state.NetNS.Name)
return nil
}
func isRootlessCgroupSet(cgroup string) bool {
return false
}
func (c *Container) expectPodCgroup() (bool, error) {
return false, nil
}
func (c *Container) getOCICgroupPath() (string, error) {
return "", nil
}
func openDirectory(path string) (fd int, err error) {
const O_PATH = 0x00400000
return unix.Open(path, unix.O_RDONLY|O_PATH|unix.O_CLOEXEC, 0)
}
func (c *Container) addNetworkNamespace(g *generate.Generator) error {
if c.config.CreateNetNS {
g.AddAnnotation("org.freebsd.parentJail", c.state.NetNS.Name)
}
return nil
}
func (c *Container) addSystemdMounts(g *generate.Generator) error {
return nil
}
func (c *Container) addSharedNamespaces(g *generate.Generator) error {
if c.config.NetNsCtr != "" {
if err := c.addNetworkContainer(g, c.config.NetNsCtr); err != nil {
return err
}
}
availableUIDs, availableGIDs, err := rootless.GetAvailableIDMaps()
if err != nil {
if os.IsNotExist(err) {
// The kernel-provided files only exist if user namespaces are supported
logrus.Debugf("User or group ID mappings not available: %s", err)
} else {
return err
}
} else {
g.Config.Linux.UIDMappings = rootless.MaybeSplitMappings(g.Config.Linux.UIDMappings, availableUIDs)
g.Config.Linux.GIDMappings = rootless.MaybeSplitMappings(g.Config.Linux.GIDMappings, availableGIDs)
}
// Hostname handling:
// If we have a UTS namespace, set Hostname in the OCI spec.
// Set the HOSTNAME environment variable unless explicitly overridden by
// the user (already present in OCI spec). If we don't have a UTS ns,
// set it to the host's hostname instead.
hostname := c.Hostname()
foundUTS := false
// TODO: make this optional, needs progress on adding FreeBSD section to the spec
foundUTS = true
g.SetHostname(hostname)
if !foundUTS {
tmpHostname, err := os.Hostname()
if err != nil {
return err
}
hostname = tmpHostname
}
needEnv := true
for _, checkEnv := range g.Config.Process.Env {
if strings.SplitN(checkEnv, "=", 2)[0] == "HOSTNAME" {
needEnv = false
break
}
}
if needEnv {
g.AddProcessEnv("HOSTNAME", hostname)
}
return nil
}
func (c *Container) addRootPropagation(g *generate.Generator, mounts []spec.Mount) error {
return nil
}
func (c *Container) setProcessLabel(g *generate.Generator) {
}
func (c *Container) setMountLabel(g *generate.Generator) {
}
func (c *Container) setCgroupsPath(g *generate.Generator) error {
return nil
}
func (c *Container) addSlirp4netnsDNS(nameservers []string) []string {
return nameservers
}
func (c *Container) isSlirp4netnsIPv6() (bool, error) {
return false, nil
}
// check for net=none
func (c *Container) hasNetNone() bool {
return c.state.NetNS == nil
}
func setVolumeAtime(mountPoint string, st os.FileInfo) error {
stat := st.Sys().(*syscall.Stat_t)
atime := time.Unix(int64(stat.Atimespec.Sec), int64(stat.Atimespec.Nsec)) //nolint: unconvert
if err := os.Chtimes(mountPoint, atime, st.ModTime()); err != nil {
return err
}
return nil
}
func (c *Container) makePlatformBindMounts() error {
return nil
}
func (c *Container) getConmonPidFd() int {
// Note: kqueue(2) could be used here but that would require
// factoring out the call to unix.PollFd from WaitForExit so
// keeping things simple for now.
return -1
}
func (c *Container) jailName() string {
if c.state.NetNS != nil {
return c.state.NetNS.Name + "." + c.ID()
} else {
return c.ID()
}
}