mirror of
https://gitea.com/Lydanne/buildx.git
synced 2025-10-31 08:03:43 +08:00
130 lines
2.5 KiB
Go
130 lines
2.5 KiB
Go
/*
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Copyright The containerd Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package continuity
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import (
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"bufio"
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"fmt"
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"io"
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"os"
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"strconv"
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"strings"
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)
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// TODO(stevvooe): This needs a lot of work before we can call it useful.
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type groupIndex struct {
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byName map[string]*group
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byGID map[int]*group
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}
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func getGroupIndex() (*groupIndex, error) {
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f, err := os.Open("/etc/group")
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if err != nil {
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return nil, err
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}
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defer f.Close()
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groups, err := parseGroups(f)
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if err != nil {
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return nil, err
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}
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return newGroupIndex(groups), nil
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}
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func newGroupIndex(groups []group) *groupIndex {
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gi := &groupIndex{
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byName: make(map[string]*group),
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byGID: make(map[int]*group),
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}
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for i, group := range groups {
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gi.byGID[group.gid] = &groups[i]
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gi.byName[group.name] = &groups[i]
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}
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return gi
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}
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type group struct {
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name string
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gid int
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members []string
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}
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func getGroupName(gid int) (string, error) {
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f, err := os.Open("/etc/group")
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if err != nil {
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return "", err
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}
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defer f.Close()
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groups, err := parseGroups(f)
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if err != nil {
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return "", err
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}
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for _, group := range groups {
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if group.gid == gid {
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return group.name, nil
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}
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}
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return "", fmt.Errorf("no group for gid")
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}
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// parseGroups parses an /etc/group file for group names, ids and membership.
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// This is unix specific.
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func parseGroups(rd io.Reader) ([]group, error) {
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var groups []group
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scanner := bufio.NewScanner(rd)
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for scanner.Scan() {
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if strings.HasPrefix(scanner.Text(), "#") {
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continue // skip comment
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}
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parts := strings.SplitN(scanner.Text(), ":", 4)
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if len(parts) != 4 {
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return nil, fmt.Errorf("bad entry: %q", scanner.Text())
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}
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name, _, sgid, smembers := parts[0], parts[1], parts[2], parts[3]
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gid, err := strconv.Atoi(sgid)
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if err != nil {
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return nil, fmt.Errorf("bad gid: %q", gid)
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}
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members := strings.Split(smembers, ",")
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groups = append(groups, group{
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name: name,
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gid: gid,
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members: members,
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})
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}
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if scanner.Err() != nil {
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return nil, scanner.Err()
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}
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return groups, nil
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}
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