68 lines
1.3 KiB
Go
68 lines
1.3 KiB
Go
package main
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import (
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"bufio"
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"errors"
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"fmt"
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"io"
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"log"
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"strings"
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)
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func parseUint32Fast(s string) (int, error) {
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sLen := len(s)
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if sLen < 1 {
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return -1, errors.New("zero length string")
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}
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if sLen > 10 {
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return -1, errors.New("string too long")
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}
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n := 0
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for i, ch := range []byte(s) {
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ch -= '0'
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if ch > 9 {
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return -1, fmt.Errorf("invalid character '%s' at index %d", string(ch+'0'), i)
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}
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n = n*10 + int(ch)
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}
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return n, nil
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}
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func parseConfig(r io.Reader, puid int) (fid int, ok bool, err error) {
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s := bufio.NewScanner(r)
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var line, puid0 int
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for s.Scan() {
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line++
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// <puid> <fid>
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lf := strings.SplitN(s.Text(), " ", 2)
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if len(lf) != 2 {
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return -1, false, fmt.Errorf("invalid entry on line %d", line)
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}
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puid0, err = parseUint32Fast(lf[0])
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if err != nil || puid0 < 1 {
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return -1, false, fmt.Errorf("invalid parent uid on line %d", line)
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}
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ok = puid0 == puid
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if ok {
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// allowed fid range 0 to 99
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if fid, err = parseUint32Fast(lf[1]); err != nil || fid < 0 || fid > 99 {
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return -1, false, fmt.Errorf("invalid fortify uid on line %d", line)
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}
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return
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}
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}
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return -1, false, s.Err()
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}
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func mustParseConfig(r io.Reader, puid int) (int, bool) {
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fid, ok, err := parseConfig(r, puid)
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if err != nil {
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log.Fatal(err)
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}
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return fid, ok
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}
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