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Split Lookup code in a separate file
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,191 @@ | ||
| package dmarc | ||
|
|
||
| import ( | ||
| "errors" | ||
| "fmt" | ||
| "net" | ||
| "strconv" | ||
| "strings" | ||
| "time" | ||
| ) | ||
|
|
||
| type tempFailError string | ||
|
|
||
| func (err tempFailError) Error() string { | ||
| return "dmarc: " + string(err) | ||
| } | ||
|
|
||
| // IsTempFail returns true if the error returned by Lookup is a temporary | ||
| // failure. | ||
| func IsTempFail(err error) bool { | ||
| _, ok := err.(tempFailError) | ||
| return ok | ||
| } | ||
|
|
||
| // Lookup queries a DMARC record for a specified domain. | ||
| func Lookup(domain string) (*Record, error) { | ||
| txts, err := net.LookupTXT("_dmarc." + domain) | ||
| if netErr, ok := err.(net.Error); ok && netErr.Temporary() { | ||
| return nil, tempFailError("TXT record unavailable: " + err.Error()) | ||
| } else if err != nil { | ||
| return nil, errors.New("dmarc: failed to lookup TXT record: " + err.Error()) | ||
| } | ||
|
|
||
| // Long keys are split in multiple parts | ||
| txt := strings.Join(txts, "") | ||
| params, err := parseParams(txt) | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
|
|
||
| if params["v"] != "DMARC1" { | ||
| return nil, errors.New("dmarc: unsupported DMARC version") | ||
| } | ||
|
|
||
| rec := new(Record) | ||
|
|
||
| p, ok := params["p"] | ||
| if !ok { | ||
| return nil, errors.New("dmarc: record is missing a 'p' parameter") | ||
| } | ||
| rec.Policy, err = parsePolicy(p, "p") | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
|
|
||
| if adkim, ok := params["adkim"]; ok { | ||
| rec.DKIMAlignment, err = parseAlignmentMode(adkim, "adkim") | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
| } | ||
|
|
||
| if aspf, ok := params["aspf"]; ok { | ||
| rec.SPFAlignment, err = parseAlignmentMode(aspf, "aspf") | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
| } | ||
|
|
||
| if fo, ok := params["fo"]; ok { | ||
| rec.FailureOptions, err = parseFailureOptions(fo) | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
| } | ||
|
|
||
| if pct, ok := params["pct"]; ok { | ||
| i, err := strconv.Atoi(pct) | ||
| if err != nil { | ||
| return nil, fmt.Errorf("dmarc: invalid parameter 'pct': %v", err) | ||
| } | ||
| if i < 0 || i > 100 { | ||
| return nil, fmt.Errorf("dmarc: invalid parameter 'pct': value %v out of bounds", i) | ||
| } | ||
| rec.Percent = &i | ||
| } | ||
|
|
||
| if rf, ok := params["rf"]; ok { | ||
| l := strings.Split(rf, ":") | ||
| rec.ReportFormat = make([]ReportFormat, len(l)) | ||
| for i, f := range l { | ||
| switch f { | ||
| case "afrf": | ||
| rec.ReportFormat[i] = ReportFormat(f) | ||
| default: | ||
| return nil, errors.New("dmarc: invalid parameter 'rf'") | ||
| } | ||
| } | ||
| } | ||
|
|
||
| if ri, ok := params["ri"]; ok { | ||
| i, err := strconv.Atoi(ri) | ||
| if err != nil { | ||
| return nil, fmt.Errorf("dmarc: invalid parameter 'ri': %v", err) | ||
| } | ||
| if i <= 0 { | ||
| return nil, fmt.Errorf("dmarc: invalid parameter 'ri': negative or zero duration") | ||
| } | ||
| rec.ReportInterval = time.Duration(i) * time.Second | ||
| } | ||
|
|
||
| if rua, ok := params["rua"]; ok { | ||
| rec.ReportURIAggregate = parseURIList(rua) | ||
| } | ||
|
|
||
| if ruf, ok := params["ruf"]; ok { | ||
| rec.ReportURIFailure = parseURIList(ruf) | ||
| } | ||
|
|
||
| if sp, ok := params["sp"]; ok { | ||
| rec.SubdomainPolicy, err = parsePolicy(sp, "sp") | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
| } | ||
|
|
||
| return rec, nil | ||
| } | ||
|
|
||
| func parseParams(s string) (map[string]string, error) { | ||
| pairs := strings.Split(s, ";") | ||
| params := make(map[string]string) | ||
| for _, s := range pairs { | ||
| kv := strings.SplitN(s, "=", 2) | ||
| if len(kv) != 2 { | ||
| if strings.TrimSpace(s) == "" { | ||
| continue | ||
| } | ||
| return params, errors.New("dmarc: malformed params") | ||
| } | ||
|
|
||
| params[strings.TrimSpace(kv[0])] = strings.TrimSpace(kv[1]) | ||
| } | ||
| return params, nil | ||
| } | ||
|
|
||
| func parsePolicy(s, param string) (Policy, error) { | ||
| switch s { | ||
| case "none", "quarantine", "reject": | ||
| return Policy(s), nil | ||
| default: | ||
| return "", fmt.Errorf("dmarc: invalid policy for parameter '%v'", param) | ||
| } | ||
| } | ||
|
|
||
| func parseAlignmentMode(s, param string) (AlignmentMode, error) { | ||
| switch s { | ||
| case "r", "s": | ||
| return AlignmentMode(s), nil | ||
| default: | ||
| return "", fmt.Errorf("dmarc: invalid alignment mode for parameter '%v'", param) | ||
| } | ||
| } | ||
|
|
||
| func parseFailureOptions(s string) (FailureOptions, error) { | ||
| l := strings.Split(s, ":") | ||
| var opts FailureOptions | ||
| for _, o := range l { | ||
| switch strings.TrimSpace(o) { | ||
| case "0": | ||
| opts |= FailureAll | ||
| case "1": | ||
| opts |= FailureAny | ||
| case "d": | ||
| opts |= FailureDKIM | ||
| case "s": | ||
| opts |= FailureSPF | ||
| default: | ||
| return 0, errors.New("dmarc: invalid failure option in parameter 'fo'") | ||
| } | ||
| } | ||
| return opts, nil | ||
| } | ||
|
|
||
| func parseURIList(s string) []string { | ||
| l := strings.Split(s, ",") | ||
| for i, u := range l { | ||
| l[i] = strings.TrimSpace(u) | ||
| } | ||
| return l | ||
| } |