From d8ff986484a6931843b067b30c9fee11e759e8f2 Mon Sep 17 00:00:00 2001 From: Tom Thorogood Date: Mon, 18 Mar 2019 17:36:44 +1030 Subject: [PATCH] Use for range loops instead of manual for loops (#937) * Use for range loops instead of manual loops * Use for range loop in Msg.CopyTo This is a separate commit as the change is slightly more than just switching the loop style. * Use for range loop in DNSKEY.publicKeyRSA * Add explen comment to DNSKEY.publicKeyRSA --- clientconfig.go | 8 ++----- dnssec.go | 5 ++-- edns.go | 22 ++++++++--------- labels.go | 4 +--- msg.go | 63 ++++++++++++++++++++----------------------------- msg_helpers.go | 10 ++++---- types.go | 12 +++++----- 7 files changed, 52 insertions(+), 72 deletions(-) diff --git a/clientconfig.go b/clientconfig.go index f13cfa30..e11b630d 100644 --- a/clientconfig.go +++ b/clientconfig.go @@ -68,14 +68,10 @@ func ClientConfigFromReader(resolvconf io.Reader) (*ClientConfig, error) { } case "search": // set search path to given servers - c.Search = make([]string, len(f)-1) - for i := 0; i < len(c.Search); i++ { - c.Search[i] = f[i+1] - } + c.Search = append([]string(nil), f[1:]...) case "options": // magic options - for i := 1; i < len(f); i++ { - s := f[i] + for _, s := range f[1:] { switch { case len(s) >= 6 && s[:6] == "ndots:": n, _ := strconv.Atoi(s[6:]) diff --git a/dnssec.go b/dnssec.go index 3a04ac31..faf1dc65 100644 --- a/dnssec.go +++ b/dnssec.go @@ -556,9 +556,10 @@ func (k *DNSKEY) publicKeyRSA() *rsa.PublicKey { pubkey := new(rsa.PublicKey) var expo uint64 - for i := 0; i < int(explen); i++ { + // The exponent of length explen is between keyoff and modoff. + for _, v := range keybuf[keyoff:modoff] { expo <<= 8 - expo |= uint64(keybuf[keyoff+i]) + expo |= uint64(v) } if expo > 1<<31-1 { // Larger exponent than supported by the crypto package. diff --git a/edns.go b/edns.go index 805641b2..ca8873e1 100644 --- a/edns.go +++ b/edns.go @@ -80,9 +80,9 @@ func (rr *OPT) String() string { func (rr *OPT) len(off int, compression map[string]struct{}) int { l := rr.Hdr.len(off, compression) - for i := 0; i < len(rr.Option); i++ { + for _, o := range rr.Option { l += 4 // Account for 2-byte option code and 2-byte option length. - lo, _ := rr.Option[i].pack() + lo, _ := o.pack() l += len(lo) } return l @@ -453,11 +453,11 @@ func (e *EDNS0_DAU) unpack(b []byte) error { e.AlgCode = b; return nil } func (e *EDNS0_DAU) String() string { s := "" - for i := 0; i < len(e.AlgCode); i++ { - if a, ok := AlgorithmToString[e.AlgCode[i]]; ok { + for _, alg := range e.AlgCode { + if a, ok := AlgorithmToString[alg]; ok { s += " " + a } else { - s += " " + strconv.Itoa(int(e.AlgCode[i])) + s += " " + strconv.Itoa(int(alg)) } } return s @@ -477,11 +477,11 @@ func (e *EDNS0_DHU) unpack(b []byte) error { e.AlgCode = b; return nil } func (e *EDNS0_DHU) String() string { s := "" - for i := 0; i < len(e.AlgCode); i++ { - if a, ok := HashToString[e.AlgCode[i]]; ok { + for _, alg := range e.AlgCode { + if a, ok := HashToString[alg]; ok { s += " " + a } else { - s += " " + strconv.Itoa(int(e.AlgCode[i])) + s += " " + strconv.Itoa(int(alg)) } } return s @@ -502,11 +502,11 @@ func (e *EDNS0_N3U) unpack(b []byte) error { e.AlgCode = b; return nil } func (e *EDNS0_N3U) String() string { // Re-use the hash map s := "" - for i := 0; i < len(e.AlgCode); i++ { - if a, ok := HashToString[e.AlgCode[i]]; ok { + for _, alg := range e.AlgCode { + if a, ok := HashToString[alg]; ok { s += " " + a } else { - s += " " + strconv.Itoa(int(e.AlgCode[i])) + s += " " + strconv.Itoa(int(alg)) } } return s diff --git a/labels.go b/labels.go index ca8c2045..e32d2a1d 100644 --- a/labels.go +++ b/labels.go @@ -28,9 +28,7 @@ func SplitDomainName(s string) (labels []string) { case 1: // no-op default: - end := 0 - for i := 1; i < len(idx); i++ { - end = idx[i] + for _, end := range idx[1:] { labels = append(labels, s[begin:end-1]) begin = end } diff --git a/msg.go b/msg.go index 5191fc06..e04fb5d7 100644 --- a/msg.go +++ b/msg.go @@ -429,8 +429,8 @@ Loop: if budget <= 0 { return "", lenmsg, ErrLongDomain } - for j := off; j < off+c; j++ { - switch b := msg[j]; b { + for _, b := range msg[off : off+c] { + switch b { case '.', '(', ')', ';', ' ', '@': fallthrough case '"', '\\': @@ -489,11 +489,11 @@ func packTxt(txt []string, msg []byte, offset int, tmp []byte) (int, error) { return offset, nil } var err error - for i := range txt { - if len(txt[i]) > len(tmp) { + for _, s := range txt { + if len(s) > len(tmp) { return offset, ErrBuf } - offset, err = packTxtString(txt[i], msg, offset, tmp) + offset, err = packTxtString(s, msg, offset, tmp) if err != nil { return offset, err } @@ -934,31 +934,31 @@ func (dns *Msg) String() string { s += "ADDITIONAL: " + strconv.Itoa(len(dns.Extra)) + "\n" if len(dns.Question) > 0 { s += "\n;; QUESTION SECTION:\n" - for i := 0; i < len(dns.Question); i++ { - s += dns.Question[i].String() + "\n" + for _, r := range dns.Question { + s += r.String() + "\n" } } if len(dns.Answer) > 0 { s += "\n;; ANSWER SECTION:\n" - for i := 0; i < len(dns.Answer); i++ { - if dns.Answer[i] != nil { - s += dns.Answer[i].String() + "\n" + for _, r := range dns.Answer { + if r != nil { + s += r.String() + "\n" } } } if len(dns.Ns) > 0 { s += "\n;; AUTHORITY SECTION:\n" - for i := 0; i < len(dns.Ns); i++ { - if dns.Ns[i] != nil { - s += dns.Ns[i].String() + "\n" + for _, r := range dns.Ns { + if r != nil { + s += r.String() + "\n" } } } if len(dns.Extra) > 0 { s += "\n;; ADDITIONAL SECTION:\n" - for i := 0; i < len(dns.Extra); i++ { - if dns.Extra[i] != nil { - s += dns.Extra[i].String() + "\n" + for _, r := range dns.Extra { + if r != nil { + s += r.String() + "\n" } } } @@ -1091,33 +1091,20 @@ func (dns *Msg) CopyTo(r1 *Msg) *Msg { } rrArr := make([]RR, len(dns.Answer)+len(dns.Ns)+len(dns.Extra)) - var rri int + r1.Answer, rrArr = rrArr[:0:len(dns.Answer)], rrArr[len(dns.Answer):] + r1.Ns, rrArr = rrArr[:0:len(dns.Ns)], rrArr[len(dns.Ns):] + r1.Extra = rrArr[:0:len(dns.Extra)] - if len(dns.Answer) > 0 { - rrbegin := rri - for i := 0; i < len(dns.Answer); i++ { - rrArr[rri] = dns.Answer[i].copy() - rri++ - } - r1.Answer = rrArr[rrbegin:rri:rri] + for _, r := range dns.Answer { + r1.Answer = append(r1.Answer, r.copy()) } - if len(dns.Ns) > 0 { - rrbegin := rri - for i := 0; i < len(dns.Ns); i++ { - rrArr[rri] = dns.Ns[i].copy() - rri++ - } - r1.Ns = rrArr[rrbegin:rri:rri] + for _, r := range dns.Ns { + r1.Ns = append(r1.Ns, r.copy()) } - if len(dns.Extra) > 0 { - rrbegin := rri - for i := 0; i < len(dns.Extra); i++ { - rrArr[rri] = dns.Extra[i].copy() - rri++ - } - r1.Extra = rrArr[rrbegin:rri:rri] + for _, r := range dns.Extra { + r1.Extra = append(r1.Extra, r.copy()) } return r1 diff --git a/msg_helpers.go b/msg_helpers.go index 527621a0..7a4184dc 100644 --- a/msg_helpers.go +++ b/msg_helpers.go @@ -553,8 +553,7 @@ func unpackDataNsec(msg []byte, off int) ([]uint16, int, error) { } // Walk the bytes in the window and extract the type bits - for j := 0; j < length; j++ { - b := msg[off+j] + for j, b := range msg[off : off+length] { // Check the bits one by one, and set the type if b&0x80 == 0x80 { nsec = append(nsec, uint16(window*256+j*8+0)) @@ -592,8 +591,7 @@ func packDataNsec(bitmap []uint16, msg []byte, off int) (int, error) { return off, nil } var lastwindow, lastlength uint16 - for j := 0; j < len(bitmap); j++ { - t := bitmap[j] + for _, t := range bitmap { window := t / 256 length := (t-window*256)/8 + 1 if window > lastwindow && lastlength != 0 { // New window, jump to the new offset @@ -639,8 +637,8 @@ func unpackDataDomainNames(msg []byte, off, end int) ([]string, int, error) { func packDataDomainNames(names []string, msg []byte, off int, compression compressionMap, compress bool) (int, error) { var err error - for j := 0; j < len(names); j++ { - off, err = packDomainName(names[j], msg, off, compression, compress) + for _, name := range names { + off, err = packDomainName(name, msg, off, compression, compress) if err != nil { return len(msg), err } diff --git a/types.go b/types.go index 921afa57..835f2fe7 100644 --- a/types.go +++ b/types.go @@ -845,8 +845,8 @@ type NSEC struct { func (rr *NSEC) String() string { s := rr.Hdr.String() + sprintName(rr.NextDomain) - for i := 0; i < len(rr.TypeBitMap); i++ { - s += " " + Type(rr.TypeBitMap[i]).String() + for _, t := range rr.TypeBitMap { + s += " " + Type(t).String() } return s } @@ -1011,8 +1011,8 @@ func (rr *NSEC3) String() string { " " + strconv.Itoa(int(rr.Iterations)) + " " + saltToString(rr.Salt) + " " + rr.NextDomain - for i := 0; i < len(rr.TypeBitMap); i++ { - s += " " + Type(rr.TypeBitMap[i]).String() + for _, t := range rr.TypeBitMap { + s += " " + Type(t).String() } return s } @@ -1335,8 +1335,8 @@ type CSYNC struct { func (rr *CSYNC) String() string { s := rr.Hdr.String() + strconv.FormatInt(int64(rr.Serial), 10) + " " + strconv.Itoa(int(rr.Flags)) - for i := 0; i < len(rr.TypeBitMap); i++ { - s += " " + Type(rr.TypeBitMap[i]).String() + for _, t := range rr.TypeBitMap { + s += " " + Type(t).String() } return s }