1 files changed, 178 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/procfs/mountinfo.go b/vendor/github.com/prometheus/procfs/mountinfo.go
new file mode 100644
index 0000000000..61fa618874
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/mountinfo.go
@@ -0,0 +1,178 @@
+// Copyright 2019 The Prometheus Authors
+// 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.
+
+package procfs
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+var validOptionalFields = map[string]bool{
+	"shared":         true,
+	"master":         true,
+	"propagate_from": true,
+	"unbindable":     true,
+}
+
+// A MountInfo is a type that describes the details, options
+// for each mount, parsed from /proc/self/mountinfo.
+// The fields described in each entry of /proc/self/mountinfo
+// is described in the following man page.
+// http://man7.org/linux/man-pages/man5/proc.5.html
+type MountInfo struct {
+	// Unique Id for the mount
+	MountId int
+	// The Id of the parent mount
+	ParentId int
+	// The value of `st_dev` for the files on this FS
+	MajorMinorVer string
+	// The pathname of the directory in the FS that forms
+	// the root for this mount
+	Root string
+	// The pathname of the mount point relative to the root
+	MountPoint string
+	// Mount options
+	Options map[string]string
+	// Zero or more optional fields
+	OptionalFields map[string]string
+	// The Filesystem type
+	FSType string
+	// FS specific information or "none"
+	Source string
+	// Superblock options
+	SuperOptions map[string]string
+}
+
+// Returns part of the mountinfo line, if it exists, else an empty string.
+func getStringSliceElement(parts []string, idx int, defaultValue string) string {
+	if idx >= len(parts) {
+		return defaultValue
+	}
+	return parts[idx]
+}
+
+// Reads each line of the mountinfo file, and returns a list of formatted MountInfo structs.
+func parseMountInfo(r io.Reader) ([]*MountInfo, error) {
+	mounts := []*MountInfo{}
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		mountString := scanner.Text()
+		parsedMounts, err := parseMountInfoString(mountString)
+		if err != nil {
+			return nil, err
+		}
+		mounts = append(mounts, parsedMounts)
+	}
+
+	err := scanner.Err()
+	return mounts, err
+}
+
+// Parses a mountinfo file line, and converts it to a MountInfo struct.
+// An important check here is to see if the hyphen separator, as if it does not exist,
+// it means that the line is malformed.
+func parseMountInfoString(mountString string) (*MountInfo, error) {
+	var err error
+
+	// OptionalFields can be zero, hence these checks to ensure we do not populate the wrong values in the wrong spots
+	separatorIndex := strings.Index(mountString, "-")
+	if separatorIndex == -1 {
+		return nil, fmt.Errorf("no separator found in mountinfo string: %s", mountString)
+	}
+	beforeFields := strings.Fields(mountString[:separatorIndex])
+	afterFields := strings.Fields(mountString[separatorIndex+1:])
+	if (len(beforeFields) + len(afterFields)) < 7 {
+		return nil, fmt.Errorf("too few fields")
+	}
+
+	mount := &MountInfo{
+		MajorMinorVer:  getStringSliceElement(beforeFields, 2, ""),
+		Root:           getStringSliceElement(beforeFields, 3, ""),
+		MountPoint:     getStringSliceElement(beforeFields, 4, ""),
+		Options:        mountOptionsParser(getStringSliceElement(beforeFields, 5, "")),
+		OptionalFields: nil,
+		FSType:         getStringSliceElement(afterFields, 0, ""),
+		Source:         getStringSliceElement(afterFields, 1, ""),
+		SuperOptions:   mountOptionsParser(getStringSliceElement(afterFields, 2, "")),
+	}
+
+	mount.MountId, err = strconv.Atoi(getStringSliceElement(beforeFields, 0, ""))
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse mount ID")
+	}
+	mount.ParentId, err = strconv.Atoi(getStringSliceElement(beforeFields, 1, ""))
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse parent ID")
+	}
+	// Has optional fields, which is a space separated list of values.
+	// Example: shared:2 master:7
+	if len(beforeFields) > 6 {
+		mount.OptionalFields = make(map[string]string)
+		optionalFields := beforeFields[6:]
+		for _, field := range optionalFields {
+			optionSplit := strings.Split(field, ":")
+			target, value := optionSplit[0], ""
+			if len(optionSplit) == 2 {
+				value = optionSplit[1]
+			}
+			// Checks if the 'keys' in the optional fields in the mountinfo line are acceptable.
+			// Allowed 'keys' are shared, master, propagate_from, unbindable.
+			if _, ok := validOptionalFields[target]; ok {
+				mount.OptionalFields[target] = value
+			}
+		}
+	}
+	return mount, nil
+}
+
+// Parses the mount options, superblock options.
+func mountOptionsParser(mountOptions string) map[string]string {
+	opts := make(map[string]string)
+	options := strings.Split(mountOptions, ",")
+	for _, opt := range options {
+		splitOption := strings.Split(opt, "=")
+		if len(splitOption) < 2 {
+			key := splitOption[0]
+			opts[key] = ""
+		} else {
+			key, value := splitOption[0], splitOption[1]
+			opts[key] = value
+		}
+	}
+	return opts
+}
+
+// Retrieves mountinfo information from `/proc/self/mountinfo`.
+func GetMounts() ([]*MountInfo, error) {
+	f, err := os.Open("/proc/self/mountinfo")
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return parseMountInfo(f)
+}
+
+// Retrieves mountinfo information from a processes' `/proc/<pid>/mountinfo`.
+func GetProcMounts(pid int) ([]*MountInfo, error) {
+	f, err := os.Open(fmt.Sprintf("/proc/%d/mountinfo", pid))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return parseMountInfo(f)
+}