From a031b83a09a8628435317a03f199cdc18b78262f Mon Sep 17 00:00:00 2001 From: Matthew Heon Date: Wed, 1 Nov 2017 11:24:59 -0400 Subject: Initial checkin from CRI-O repo Signed-off-by: Matthew Heon --- .../opencontainers/runc/libcontainer/utils/cmsg.go | 95 +++++++++++++++ .../runc/libcontainer/utils/utils.go | 127 +++++++++++++++++++++ .../runc/libcontainer/utils/utils_unix.go | 44 +++++++ 3 files changed, 266 insertions(+) create mode 100644 vendor/github.com/opencontainers/runc/libcontainer/utils/cmsg.go create mode 100644 vendor/github.com/opencontainers/runc/libcontainer/utils/utils.go create mode 100644 vendor/github.com/opencontainers/runc/libcontainer/utils/utils_unix.go (limited to 'vendor/github.com/opencontainers/runc/libcontainer/utils') diff --git a/vendor/github.com/opencontainers/runc/libcontainer/utils/cmsg.go b/vendor/github.com/opencontainers/runc/libcontainer/utils/cmsg.go new file mode 100644 index 000000000..2cbb6491a --- /dev/null +++ b/vendor/github.com/opencontainers/runc/libcontainer/utils/cmsg.go @@ -0,0 +1,95 @@ +// +build linux + +package utils + +/* + * Copyright 2016, 2017 SUSE LLC + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +import ( + "fmt" + "os" + + "golang.org/x/sys/unix" +) + +// MaxSendfdLen is the maximum length of the name of a file descriptor being +// sent using SendFd. The name of the file handle returned by RecvFd will never +// be larger than this value. +const MaxNameLen = 4096 + +// oobSpace is the size of the oob slice required to store a single FD. Note +// that unix.UnixRights appears to make the assumption that fd is always int32, +// so sizeof(fd) = 4. +var oobSpace = unix.CmsgSpace(4) + +// RecvFd waits for a file descriptor to be sent over the given AF_UNIX +// socket. The file name of the remote file descriptor will be recreated +// locally (it is sent as non-auxiliary data in the same payload). +func RecvFd(socket *os.File) (*os.File, error) { + // For some reason, unix.Recvmsg uses the length rather than the capacity + // when passing the msg_controllen and other attributes to recvmsg. So we + // have to actually set the length. + name := make([]byte, MaxNameLen) + oob := make([]byte, oobSpace) + + sockfd := socket.Fd() + n, oobn, _, _, err := unix.Recvmsg(int(sockfd), name, oob, 0) + if err != nil { + return nil, err + } + + if n >= MaxNameLen || oobn != oobSpace { + return nil, fmt.Errorf("recvfd: incorrect number of bytes read (n=%d oobn=%d)", n, oobn) + } + + // Truncate. + name = name[:n] + oob = oob[:oobn] + + scms, err := unix.ParseSocketControlMessage(oob) + if err != nil { + return nil, err + } + if len(scms) != 1 { + return nil, fmt.Errorf("recvfd: number of SCMs is not 1: %d", len(scms)) + } + scm := scms[0] + + fds, err := unix.ParseUnixRights(&scm) + if err != nil { + return nil, err + } + if len(fds) != 1 { + return nil, fmt.Errorf("recvfd: number of fds is not 1: %d", len(fds)) + } + fd := uintptr(fds[0]) + + return os.NewFile(fd, string(name)), nil +} + +// SendFd sends a file descriptor over the given AF_UNIX socket. In +// addition, the file.Name() of the given file will also be sent as +// non-auxiliary data in the same payload (allowing to send contextual +// information for a file descriptor). +func SendFd(socket, file *os.File) error { + name := []byte(file.Name()) + if len(name) >= MaxNameLen { + return fmt.Errorf("sendfd: filename too long: %s", file.Name()) + } + oob := unix.UnixRights(int(file.Fd())) + + return unix.Sendmsg(int(socket.Fd()), name, oob, nil, 0) +} diff --git a/vendor/github.com/opencontainers/runc/libcontainer/utils/utils.go b/vendor/github.com/opencontainers/runc/libcontainer/utils/utils.go new file mode 100644 index 000000000..baa54c9ba --- /dev/null +++ b/vendor/github.com/opencontainers/runc/libcontainer/utils/utils.go @@ -0,0 +1,127 @@ +package utils + +import ( + "crypto/rand" + "encoding/hex" + "encoding/json" + "io" + "os" + "path/filepath" + "strings" + "unsafe" + + "golang.org/x/sys/unix" +) + +const ( + exitSignalOffset = 128 +) + +// GenerateRandomName returns a new name joined with a prefix. This size +// specified is used to truncate the randomly generated value +func GenerateRandomName(prefix string, size int) (string, error) { + id := make([]byte, 32) + if _, err := io.ReadFull(rand.Reader, id); err != nil { + return "", err + } + if size > 64 { + size = 64 + } + return prefix + hex.EncodeToString(id)[:size], nil +} + +// ResolveRootfs ensures that the current working directory is +// not a symlink and returns the absolute path to the rootfs +func ResolveRootfs(uncleanRootfs string) (string, error) { + rootfs, err := filepath.Abs(uncleanRootfs) + if err != nil { + return "", err + } + return filepath.EvalSymlinks(rootfs) +} + +// ExitStatus returns the correct exit status for a process based on if it +// was signaled or exited cleanly +func ExitStatus(status unix.WaitStatus) int { + if status.Signaled() { + return exitSignalOffset + int(status.Signal()) + } + return status.ExitStatus() +} + +// WriteJSON writes the provided struct v to w using standard json marshaling +func WriteJSON(w io.Writer, v interface{}) error { + data, err := json.Marshal(v) + if err != nil { + return err + } + _, err = w.Write(data) + return err +} + +// CleanPath makes a path safe for use with filepath.Join. This is done by not +// only cleaning the path, but also (if the path is relative) adding a leading +// '/' and cleaning it (then removing the leading '/'). This ensures that a +// path resulting from prepending another path will always resolve to lexically +// be a subdirectory of the prefixed path. This is all done lexically, so paths +// that include symlinks won't be safe as a result of using CleanPath. +func CleanPath(path string) string { + // Deal with empty strings nicely. + if path == "" { + return "" + } + + // Ensure that all paths are cleaned (especially problematic ones like + // "/../../../../../" which can cause lots of issues). + path = filepath.Clean(path) + + // If the path isn't absolute, we need to do more processing to fix paths + // such as "../../../..//some/path". We also shouldn't convert absolute + // paths to relative ones. + if !filepath.IsAbs(path) { + path = filepath.Clean(string(os.PathSeparator) + path) + // This can't fail, as (by definition) all paths are relative to root. + path, _ = filepath.Rel(string(os.PathSeparator), path) + } + + // Clean the path again for good measure. + return filepath.Clean(path) +} + +// SearchLabels searches a list of key-value pairs for the provided key and +// returns the corresponding value. The pairs must be separated with '='. +func SearchLabels(labels []string, query string) string { + for _, l := range labels { + parts := strings.SplitN(l, "=", 2) + if len(parts) < 2 { + continue + } + if parts[0] == query { + return parts[1] + } + } + return "" +} + +// Annotations returns the bundle path and user defined annotations from the +// libcontainer state. We need to remove the bundle because that is a label +// added by libcontainer. +func Annotations(labels []string) (bundle string, userAnnotations map[string]string) { + userAnnotations = make(map[string]string) + for _, l := range labels { + parts := strings.SplitN(l, "=", 2) + if len(parts) < 2 { + continue + } + if parts[0] == "bundle" { + bundle = parts[1] + } else { + userAnnotations[parts[0]] = parts[1] + } + } + return +} + +func GetIntSize() int { + return int(unsafe.Sizeof(1)) +} diff --git a/vendor/github.com/opencontainers/runc/libcontainer/utils/utils_unix.go b/vendor/github.com/opencontainers/runc/libcontainer/utils/utils_unix.go new file mode 100644 index 000000000..c96088988 --- /dev/null +++ b/vendor/github.com/opencontainers/runc/libcontainer/utils/utils_unix.go @@ -0,0 +1,44 @@ +// +build !windows + +package utils + +import ( + "io/ioutil" + "os" + "strconv" + + "golang.org/x/sys/unix" +) + +func CloseExecFrom(minFd int) error { + fdList, err := ioutil.ReadDir("/proc/self/fd") + if err != nil { + return err + } + for _, fi := range fdList { + fd, err := strconv.Atoi(fi.Name()) + if err != nil { + // ignore non-numeric file names + continue + } + + if fd < minFd { + // ignore descriptors lower than our specified minimum + continue + } + + // intentionally ignore errors from unix.CloseOnExec + unix.CloseOnExec(fd) + // the cases where this might fail are basically file descriptors that have already been closed (including and especially the one that was created when ioutil.ReadDir did the "opendir" syscall) + } + return nil +} + +// NewSockPair returns a new unix socket pair +func NewSockPair(name string) (parent *os.File, child *os.File, err error) { + fds, err := unix.Socketpair(unix.AF_LOCAL, unix.SOCK_STREAM|unix.SOCK_CLOEXEC, 0) + if err != nil { + return nil, nil, err + } + return os.NewFile(uintptr(fds[1]), name+"-p"), os.NewFile(uintptr(fds[0]), name+"-c"), nil +} -- cgit v1.2.3-54-g00ecf