diff options
Diffstat (limited to 'vendor/github.com/miekg/dns/vendor/golang.org/x/net/dns/dnsmessage')
3 files changed, 3274 insertions, 0 deletions
diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/dns/dnsmessage/example_test.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/dns/dnsmessage/example_test.go new file mode 100644 index 000000000..5415c2d3a --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/dns/dnsmessage/example_test.go @@ -0,0 +1,132 @@ +// Copyright 2017 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package dnsmessage_test + +import ( + "fmt" + "net" + "strings" + + "golang.org/x/net/dns/dnsmessage" +) + +func mustNewName(name string) dnsmessage.Name { + n, err := dnsmessage.NewName(name) + if err != nil { + panic(err) + } + return n +} + +func ExampleParser() { + msg := dnsmessage.Message{ + Header: dnsmessage.Header{Response: true, Authoritative: true}, + Questions: []dnsmessage.Question{ + { + Name: mustNewName("foo.bar.example.com."), + Type: dnsmessage.TypeA, + Class: dnsmessage.ClassINET, + }, + { + Name: mustNewName("bar.example.com."), + Type: dnsmessage.TypeA, + Class: dnsmessage.ClassINET, + }, + }, + Answers: []dnsmessage.Resource{ + { + dnsmessage.ResourceHeader{ + Name: mustNewName("foo.bar.example.com."), + Type: dnsmessage.TypeA, + Class: dnsmessage.ClassINET, + }, + &dnsmessage.AResource{[4]byte{127, 0, 0, 1}}, + }, + { + dnsmessage.ResourceHeader{ + Name: mustNewName("bar.example.com."), + Type: dnsmessage.TypeA, + Class: dnsmessage.ClassINET, + }, + &dnsmessage.AResource{[4]byte{127, 0, 0, 2}}, + }, + }, + } + + buf, err := msg.Pack() + if err != nil { + panic(err) + } + + wantName := "bar.example.com." + + var p dnsmessage.Parser + if _, err := p.Start(buf); err != nil { + panic(err) + } + + for { + q, err := p.Question() + if err == dnsmessage.ErrSectionDone { + break + } + if err != nil { + panic(err) + } + + if q.Name.String() != wantName { + continue + } + + fmt.Println("Found question for name", wantName) + if err := p.SkipAllQuestions(); err != nil { + panic(err) + } + break + } + + var gotIPs []net.IP + for { + h, err := p.AnswerHeader() + if err == dnsmessage.ErrSectionDone { + break + } + if err != nil { + panic(err) + } + + if (h.Type != dnsmessage.TypeA && h.Type != dnsmessage.TypeAAAA) || h.Class != dnsmessage.ClassINET { + continue + } + + if !strings.EqualFold(h.Name.String(), wantName) { + if err := p.SkipAnswer(); err != nil { + panic(err) + } + continue + } + + switch h.Type { + case dnsmessage.TypeA: + r, err := p.AResource() + if err != nil { + panic(err) + } + gotIPs = append(gotIPs, r.A[:]) + case dnsmessage.TypeAAAA: + r, err := p.AAAAResource() + if err != nil { + panic(err) + } + gotIPs = append(gotIPs, r.AAAA[:]) + } + } + + fmt.Printf("Found A/AAAA records for name %s: %v\n", wantName, gotIPs) + + // Output: + // Found question for name bar.example.com. + // Found A/AAAA records for name bar.example.com.: [127.0.0.2] +} diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/dns/dnsmessage/message.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/dns/dnsmessage/message.go new file mode 100644 index 000000000..c7244b782 --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/dns/dnsmessage/message.go @@ -0,0 +1,2001 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package dnsmessage provides a mostly RFC 1035 compliant implementation of +// DNS message packing and unpacking. +// +// This implementation is designed to minimize heap allocations and avoid +// unnecessary packing and unpacking as much as possible. +package dnsmessage + +import ( + "errors" +) + +// Packet formats + +// A Type is a type of DNS request and response. +type Type uint16 + +// A Class is a type of network. +type Class uint16 + +// An OpCode is a DNS operation code. +type OpCode uint16 + +// An RCode is a DNS response status code. +type RCode uint16 + +// Wire constants. +const ( + // ResourceHeader.Type and Question.Type + TypeA Type = 1 + TypeNS Type = 2 + TypeCNAME Type = 5 + TypeSOA Type = 6 + TypePTR Type = 12 + TypeMX Type = 15 + TypeTXT Type = 16 + TypeAAAA Type = 28 + TypeSRV Type = 33 + + // Question.Type + TypeWKS Type = 11 + TypeHINFO Type = 13 + TypeMINFO Type = 14 + TypeAXFR Type = 252 + TypeALL Type = 255 + + // ResourceHeader.Class and Question.Class + ClassINET Class = 1 + ClassCSNET Class = 2 + ClassCHAOS Class = 3 + ClassHESIOD Class = 4 + + // Question.Class + ClassANY Class = 255 + + // Message.Rcode + RCodeSuccess RCode = 0 + RCodeFormatError RCode = 1 + RCodeServerFailure RCode = 2 + RCodeNameError RCode = 3 + RCodeNotImplemented RCode = 4 + RCodeRefused RCode = 5 +) + +var ( + // ErrNotStarted indicates that the prerequisite information isn't + // available yet because the previous records haven't been appropriately + // parsed, skipped or finished. + ErrNotStarted = errors.New("parsing/packing of this type isn't available yet") + + // ErrSectionDone indicated that all records in the section have been + // parsed or finished. + ErrSectionDone = errors.New("parsing/packing of this section has completed") + + errBaseLen = errors.New("insufficient data for base length type") + errCalcLen = errors.New("insufficient data for calculated length type") + errReserved = errors.New("segment prefix is reserved") + errTooManyPtr = errors.New("too many pointers (>10)") + errInvalidPtr = errors.New("invalid pointer") + errNilResouceBody = errors.New("nil resource body") + errResourceLen = errors.New("insufficient data for resource body length") + errSegTooLong = errors.New("segment length too long") + errZeroSegLen = errors.New("zero length segment") + errResTooLong = errors.New("resource length too long") + errTooManyQuestions = errors.New("too many Questions to pack (>65535)") + errTooManyAnswers = errors.New("too many Answers to pack (>65535)") + errTooManyAuthorities = errors.New("too many Authorities to pack (>65535)") + errTooManyAdditionals = errors.New("too many Additionals to pack (>65535)") + errNonCanonicalName = errors.New("name is not in canonical format (it must end with a .)") +) + +// Internal constants. +const ( + // packStartingCap is the default initial buffer size allocated during + // packing. + // + // The starting capacity doesn't matter too much, but most DNS responses + // Will be <= 512 bytes as it is the limit for DNS over UDP. + packStartingCap = 512 + + // uint16Len is the length (in bytes) of a uint16. + uint16Len = 2 + + // uint32Len is the length (in bytes) of a uint32. + uint32Len = 4 + + // headerLen is the length (in bytes) of a DNS header. + // + // A header is comprised of 6 uint16s and no padding. + headerLen = 6 * uint16Len +) + +type nestedError struct { + // s is the current level's error message. + s string + + // err is the nested error. + err error +} + +// nestedError implements error.Error. +func (e *nestedError) Error() string { + return e.s + ": " + e.err.Error() +} + +// Header is a representation of a DNS message header. +type Header struct { + ID uint16 + Response bool + OpCode OpCode + Authoritative bool + Truncated bool + RecursionDesired bool + RecursionAvailable bool + RCode RCode +} + +func (m *Header) pack() (id uint16, bits uint16) { + id = m.ID + bits = uint16(m.OpCode)<<11 | uint16(m.RCode) + if m.RecursionAvailable { + bits |= headerBitRA + } + if m.RecursionDesired { + bits |= headerBitRD + } + if m.Truncated { + bits |= headerBitTC + } + if m.Authoritative { + bits |= headerBitAA + } + if m.Response { + bits |= headerBitQR + } + return +} + +// Message is a representation of a DNS message. +type Message struct { + Header + Questions []Question + Answers []Resource + Authorities []Resource + Additionals []Resource +} + +type section uint8 + +const ( + sectionNotStarted section = iota + sectionHeader + sectionQuestions + sectionAnswers + sectionAuthorities + sectionAdditionals + sectionDone + + headerBitQR = 1 << 15 // query/response (response=1) + headerBitAA = 1 << 10 // authoritative + headerBitTC = 1 << 9 // truncated + headerBitRD = 1 << 8 // recursion desired + headerBitRA = 1 << 7 // recursion available +) + +var sectionNames = map[section]string{ + sectionHeader: "header", + sectionQuestions: "Question", + sectionAnswers: "Answer", + sectionAuthorities: "Authority", + sectionAdditionals: "Additional", +} + +// header is the wire format for a DNS message header. +type header struct { + id uint16 + bits uint16 + questions uint16 + answers uint16 + authorities uint16 + additionals uint16 +} + +func (h *header) count(sec section) uint16 { + switch sec { + case sectionQuestions: + return h.questions + case sectionAnswers: + return h.answers + case sectionAuthorities: + return h.authorities + case sectionAdditionals: + return h.additionals + } + return 0 +} + +func (h *header) pack(msg []byte) []byte { + msg = packUint16(msg, h.id) + msg = packUint16(msg, h.bits) + msg = packUint16(msg, h.questions) + msg = packUint16(msg, h.answers) + msg = packUint16(msg, h.authorities) + return packUint16(msg, h.additionals) +} + +func (h *header) unpack(msg []byte, off int) (int, error) { + newOff := off + var err error + if h.id, newOff, err = unpackUint16(msg, newOff); err != nil { + return off, &nestedError{"id", err} + } + if h.bits, newOff, err = unpackUint16(msg, newOff); err != nil { + return off, &nestedError{"bits", err} + } + if h.questions, newOff, err = unpackUint16(msg, newOff); err != nil { + return off, &nestedError{"questions", err} + } + if h.answers, newOff, err = unpackUint16(msg, newOff); err != nil { + return off, &nestedError{"answers", err} + } + if h.authorities, newOff, err = unpackUint16(msg, newOff); err != nil { + return off, &nestedError{"authorities", err} + } + if h.additionals, newOff, err = unpackUint16(msg, newOff); err != nil { + return off, &nestedError{"additionals", err} + } + return newOff, nil +} + +func (h *header) header() Header { + return Header{ + ID: h.id, + Response: (h.bits & headerBitQR) != 0, + OpCode: OpCode(h.bits>>11) & 0xF, + Authoritative: (h.bits & headerBitAA) != 0, + Truncated: (h.bits & headerBitTC) != 0, + RecursionDesired: (h.bits & headerBitRD) != 0, + RecursionAvailable: (h.bits & headerBitRA) != 0, + RCode: RCode(h.bits & 0xF), + } +} + +// A Resource is a DNS resource record. +type Resource struct { + Header ResourceHeader + Body ResourceBody +} + +// A ResourceBody is a DNS resource record minus the header. +type ResourceBody interface { + // pack packs a Resource except for its header. + pack(msg []byte, compression map[string]int) ([]byte, error) + + // realType returns the actual type of the Resource. This is used to + // fill in the header Type field. + realType() Type +} + +func (r *Resource) pack(msg []byte, compression map[string]int) ([]byte, error) { + if r.Body == nil { + return msg, errNilResouceBody + } + oldMsg := msg + r.Header.Type = r.Body.realType() + msg, length, err := r.Header.pack(msg, compression) + if err != nil { + return msg, &nestedError{"ResourceHeader", err} + } + preLen := len(msg) + msg, err = r.Body.pack(msg, compression) + if err != nil { + return msg, &nestedError{"content", err} + } + if err := r.Header.fixLen(msg, length, preLen); err != nil { + return oldMsg, err + } + return msg, nil +} + +// A Parser allows incrementally parsing a DNS message. +// +// When parsing is started, the Header is parsed. Next, each Question can be +// either parsed or skipped. Alternatively, all Questions can be skipped at +// once. When all Questions have been parsed, attempting to parse Questions +// will return (nil, nil) and attempting to skip Questions will return +// (true, nil). After all Questions have been either parsed or skipped, all +// Answers, Authorities and Additionals can be either parsed or skipped in the +// same way, and each type of Resource must be fully parsed or skipped before +// proceeding to the next type of Resource. +// +// Note that there is no requirement to fully skip or parse the message. +type Parser struct { + msg []byte + header header + + section section + off int + index int + resHeaderValid bool + resHeader ResourceHeader +} + +// Start parses the header and enables the parsing of Questions. +func (p *Parser) Start(msg []byte) (Header, error) { + if p.msg != nil { + *p = Parser{} + } + p.msg = msg + var err error + if p.off, err = p.header.unpack(msg, 0); err != nil { + return Header{}, &nestedError{"unpacking header", err} + } + p.section = sectionQuestions + return p.header.header(), nil +} + +func (p *Parser) checkAdvance(sec section) error { + if p.section < sec { + return ErrNotStarted + } + if p.section > sec { + return ErrSectionDone + } + p.resHeaderValid = false + if p.index == int(p.header.count(sec)) { + p.index = 0 + p.section++ + return ErrSectionDone + } + return nil +} + +func (p *Parser) resource(sec section) (Resource, error) { + var r Resource + var err error + r.Header, err = p.resourceHeader(sec) + if err != nil { + return r, err + } + p.resHeaderValid = false + r.Body, p.off, err = unpackResourceBody(p.msg, p.off, r.Header) + if err != nil { + return Resource{}, &nestedError{"unpacking " + sectionNames[sec], err} + } + p.index++ + return r, nil +} + +func (p *Parser) resourceHeader(sec section) (ResourceHeader, error) { + if p.resHeaderValid { + return p.resHeader, nil + } + if err := p.checkAdvance(sec); err != nil { + return ResourceHeader{}, err + } + var hdr ResourceHeader + off, err := hdr.unpack(p.msg, p.off) + if err != nil { + return ResourceHeader{}, err + } + p.resHeaderValid = true + p.resHeader = hdr + p.off = off + return hdr, nil +} + +func (p *Parser) skipResource(sec section) error { + if p.resHeaderValid { + newOff := p.off + int(p.resHeader.Length) + if newOff > len(p.msg) { + return errResourceLen + } + p.off = newOff + p.resHeaderValid = false + p.index++ + return nil + } + if err := p.checkAdvance(sec); err != nil { + return err + } + var err error + p.off, err = skipResource(p.msg, p.off) + if err != nil { + return &nestedError{"skipping: " + sectionNames[sec], err} + } + p.index++ + return nil +} + +// Question parses a single Question. +func (p *Parser) Question() (Question, error) { + if err := p.checkAdvance(sectionQuestions); err != nil { + return Question{}, err + } + var name Name + off, err := name.unpack(p.msg, p.off) + if err != nil { + return Question{}, &nestedError{"unpacking Question.Name", err} + } + typ, off, err := unpackType(p.msg, off) + if err != nil { + return Question{}, &nestedError{"unpacking Question.Type", err} + } + class, off, err := unpackClass(p.msg, off) + if err != nil { + return Question{}, &nestedError{"unpacking Question.Class", err} + } + p.off = off + p.index++ + return Question{name, typ, class}, nil +} + +// AllQuestions parses all Questions. +func (p *Parser) AllQuestions() ([]Question, error) { + qs := make([]Question, 0, p.header.questions) + for { + q, err := p.Question() + if err == ErrSectionDone { + return qs, nil + } + if err != nil { + return nil, err + } + qs = append(qs, q) + } +} + +// SkipQuestion skips a single Question. +func (p *Parser) SkipQuestion() error { + if err := p.checkAdvance(sectionQuestions); err != nil { + return err + } + off, err := skipName(p.msg, p.off) + if err != nil { + return &nestedError{"skipping Question Name", err} + } + if off, err = skipType(p.msg, off); err != nil { + return &nestedError{"skipping Question Type", err} + } + if off, err = skipClass(p.msg, off); err != nil { + return &nestedError{"skipping Question Class", err} + } + p.off = off + p.index++ + return nil +} + +// SkipAllQuestions skips all Questions. +func (p *Parser) SkipAllQuestions() error { + for { + if err := p.SkipQuestion(); err == ErrSectionDone { + return nil + } else if err != nil { + return err + } + } +} + +// AnswerHeader parses a single Answer ResourceHeader. +func (p *Parser) AnswerHeader() (ResourceHeader, error) { + return p.resourceHeader(sectionAnswers) +} + +// Answer parses a single Answer Resource. +func (p *Parser) Answer() (Resource, error) { + return p.resource(sectionAnswers) +} + +// AllAnswers parses all Answer Resources. +func (p *Parser) AllAnswers() ([]Resource, error) { + as := make([]Resource, 0, p.header.answers) + for { + a, err := p.Answer() + if err == ErrSectionDone { + return as, nil + } + if err != nil { + return nil, err + } + as = append(as, a) + } +} + +// SkipAnswer skips a single Answer Resource. +func (p *Parser) SkipAnswer() error { + return p.skipResource(sectionAnswers) +} + +// SkipAllAnswers skips all Answer Resources. +func (p *Parser) SkipAllAnswers() error { + for { + if err := p.SkipAnswer(); err == ErrSectionDone { + return nil + } else if err != nil { + return err + } + } +} + +// AuthorityHeader parses a single Authority ResourceHeader. +func (p *Parser) AuthorityHeader() (ResourceHeader, error) { + return p.resourceHeader(sectionAuthorities) +} + +// Authority parses a single Authority Resource. +func (p *Parser) Authority() (Resource, error) { + return p.resource(sectionAuthorities) +} + +// AllAuthorities parses all Authority Resources. +func (p *Parser) AllAuthorities() ([]Resource, error) { + as := make([]Resource, 0, p.header.authorities) + for { + a, err := p.Authority() + if err == ErrSectionDone { + return as, nil + } + if err != nil { + return nil, err + } + as = append(as, a) + } +} + +// SkipAuthority skips a single Authority Resource. +func (p *Parser) SkipAuthority() error { + return p.skipResource(sectionAuthorities) +} + +// SkipAllAuthorities skips all Authority Resources. +func (p *Parser) SkipAllAuthorities() error { + for { + if err := p.SkipAuthority(); err == ErrSectionDone { + return nil + } else if err != nil { + return err + } + } +} + +// AdditionalHeader parses a single Additional ResourceHeader. +func (p *Parser) AdditionalHeader() (ResourceHeader, error) { + return p.resourceHeader(sectionAdditionals) +} + +// Additional parses a single Additional Resource. +func (p *Parser) Additional() (Resource, error) { + return p.resource(sectionAdditionals) +} + +// AllAdditionals parses all Additional Resources. +func (p *Parser) AllAdditionals() ([]Resource, error) { + as := make([]Resource, 0, p.header.additionals) + for { + a, err := p.Additional() + if err == ErrSectionDone { + return as, nil + } + if err != nil { + return nil, err + } + as = append(as, a) + } +} + +// SkipAdditional skips a single Additional Resource. +func (p *Parser) SkipAdditional() error { + return p.skipResource(sectionAdditionals) +} + +// SkipAllAdditionals skips all Additional Resources. +func (p *Parser) SkipAllAdditionals() error { + for { + if err := p.SkipAdditional(); err == ErrSectionDone { + return nil + } else if err != nil { + return err + } + } +} + +// CNAMEResource parses a single CNAMEResource. +// +// One of the XXXHeader methods must have been called before calling this +// method. +func (p *Parser) CNAMEResource() (CNAMEResource, error) { + if !p.resHeaderValid || p.resHeader.Type != TypeCNAME { + return CNAMEResource{}, ErrNotStarted + } + r, err := unpackCNAMEResource(p.msg, p.off) + if err != nil { + return CNAMEResource{}, err + } + p.off += int(p.resHeader.Length) + p.resHeaderValid = false + p.index++ + return r, nil +} + +// MXResource parses a single MXResource. +// +// One of the XXXHeader methods must have been called before calling this +// method. +func (p *Parser) MXResource() (MXResource, error) { + if !p.resHeaderValid || p.resHeader.Type != TypeMX { + return MXResource{}, ErrNotStarted + } + r, err := unpackMXResource(p.msg, p.off) + if err != nil { + return MXResource{}, err + } + p.off += int(p.resHeader.Length) + p.resHeaderValid = false + p.index++ + return r, nil +} + +// NSResource parses a single NSResource. +// +// One of the XXXHeader methods must have been called before calling this +// method. +func (p *Parser) NSResource() (NSResource, error) { + if !p.resHeaderValid || p.resHeader.Type != TypeNS { + return NSResource{}, ErrNotStarted + } + r, err := unpackNSResource(p.msg, p.off) + if err != nil { + return NSResource{}, err + } + p.off += int(p.resHeader.Length) + p.resHeaderValid = false + p.index++ + return r, nil +} + +// PTRResource parses a single PTRResource. +// +// One of the XXXHeader methods must have been called before calling this +// method. +func (p *Parser) PTRResource() (PTRResource, error) { + if !p.resHeaderValid || p.resHeader.Type != TypePTR { + return PTRResource{}, ErrNotStarted + } + r, err := unpackPTRResource(p.msg, p.off) + if err != nil { + return PTRResource{}, err + } + p.off += int(p.resHeader.Length) + p.resHeaderValid = false + p.index++ + return r, nil +} + +// SOAResource parses a single SOAResource. +// +// One of the XXXHeader methods must have been called before calling this +// method. +func (p *Parser) SOAResource() (SOAResource, error) { + if !p.resHeaderValid || p.resHeader.Type != TypeSOA { + return SOAResource{}, ErrNotStarted + } + r, err := unpackSOAResource(p.msg, p.off) + if err != nil { + return SOAResource{}, err + } + p.off += int(p.resHeader.Length) + p.resHeaderValid = false + p.index++ + return r, nil +} + +// TXTResource parses a single TXTResource. +// +// One of the XXXHeader methods must have been called before calling this +// method. +func (p *Parser) TXTResource() (TXTResource, error) { + if !p.resHeaderValid || p.resHeader.Type != TypeTXT { + return TXTResource{}, ErrNotStarted + } + r, err := unpackTXTResource(p.msg, p.off, p.resHeader.Length) + if err != nil { + return TXTResource{}, err + } + p.off += int(p.resHeader.Length) + p.resHeaderValid = false + p.index++ + return r, nil +} + +// SRVResource parses a single SRVResource. +// +// One of the XXXHeader methods must have been called before calling this +// method. +func (p *Parser) SRVResource() (SRVResource, error) { + if !p.resHeaderValid || p.resHeader.Type != TypeSRV { + return SRVResource{}, ErrNotStarted + } + r, err := unpackSRVResource(p.msg, p.off) + if err != nil { + return SRVResource{}, err + } + p.off += int(p.resHeader.Length) + p.resHeaderValid = false + p.index++ + return r, nil +} + +// AResource parses a single AResource. +// +// One of the XXXHeader methods must have been called before calling this +// method. +func (p *Parser) AResource() (AResource, error) { + if !p.resHeaderValid || p.resHeader.Type != TypeA { + return AResource{}, ErrNotStarted + } + r, err := unpackAResource(p.msg, p.off) + if err != nil { + return AResource{}, err + } + p.off += int(p.resHeader.Length) + p.resHeaderValid = false + p.index++ + return r, nil +} + +// AAAAResource parses a single AAAAResource. +// +// One of the XXXHeader methods must have been called before calling this +// method. +func (p *Parser) AAAAResource() (AAAAResource, error) { + if !p.resHeaderValid || p.resHeader.Type != TypeAAAA { + return AAAAResource{}, ErrNotStarted + } + r, err := unpackAAAAResource(p.msg, p.off) + if err != nil { + return AAAAResource{}, err + } + p.off += int(p.resHeader.Length) + p.resHeaderValid = false + p.index++ + return r, nil +} + +// Unpack parses a full Message. +func (m *Message) Unpack(msg []byte) error { + var p Parser + var err error + if m.Header, err = p.Start(msg); err != nil { + return err + } + if m.Questions, err = p.AllQuestions(); err != nil { + return err + } + if m.Answers, err = p.AllAnswers(); err != nil { + return err + } + if m.Authorities, err = p.AllAuthorities(); err != nil { + return err + } + if m.Additionals, err = p.AllAdditionals(); err != nil { + return err + } + return nil +} + +// Pack packs a full Message. +func (m *Message) Pack() ([]byte, error) { + return m.AppendPack(make([]byte, 0, packStartingCap)) +} + +// AppendPack is like Pack but appends the full Message to b and returns the +// extended buffer. +func (m *Message) AppendPack(b []byte) ([]byte, error) { + // Validate the lengths. It is very unlikely that anyone will try to + // pack more than 65535 of any particular type, but it is possible and + // we should fail gracefully. + if len(m.Questions) > int(^uint16(0)) { + return nil, errTooManyQuestions + } + if len(m.Answers) > int(^uint16(0)) { + return nil, errTooManyAnswers + } + if len(m.Authorities) > int(^uint16(0)) { + return nil, errTooManyAuthorities + } + if len(m.Additionals) > int(^uint16(0)) { + return nil, errTooManyAdditionals + } + + var h header + h.id, h.bits = m.Header.pack() + + h.questions = uint16(len(m.Questions)) + h.answers = uint16(len(m.Answers)) + h.authorities = uint16(len(m.Authorities)) + h.additionals = uint16(len(m.Additionals)) + + msg := h.pack(b) + + // RFC 1035 allows (but does not require) compression for packing. RFC + // 1035 requires unpacking implementations to support compression, so + // unconditionally enabling it is fine. + // + // DNS lookups are typically done over UDP, and RFC 1035 states that UDP + // DNS packets can be a maximum of 512 bytes long. Without compression, + // many DNS response packets are over this limit, so enabling + // compression will help ensure compliance. + compression := map[string]int{} + + for i := range m.Questions { + var err error + if msg, err = m.Questions[i].pack(msg, compression); err != nil { + return nil, &nestedError{"packing Question", err} + } + } + for i := range m.Answers { + var err error + if msg, err = m.Answers[i].pack(msg, compression); err != nil { + return nil, &nestedError{"packing Answer", err} + } + } + for i := range m.Authorities { + var err error + if msg, err = m.Authorities[i].pack(msg, compression); err != nil { + return nil, &nestedError{"packing Authority", err} + } + } + for i := range m.Additionals { + var err error + if msg, err = m.Additionals[i].pack(msg, compression); err != nil { + return nil, &nestedError{"packing Additional", err} + } + } + + return msg, nil +} + +// A Builder allows incrementally packing a DNS message. +type Builder struct { + msg []byte + header header + section section + compression map[string]int +} + +// Start initializes the builder. +// +// buf is optional (nil is fine), but if provided, Start takes ownership of buf. +func (b *Builder) Start(buf []byte, h Header) { + b.StartWithoutCompression(buf, h) + b.compression = map[string]int{} +} + +// StartWithoutCompression initializes the builder with compression disabled. +// +// This avoids compression related allocations, but can result in larger message +// sizes. Be careful with this mode as it can cause messages to exceed the UDP +// size limit. +// +// buf is optional (nil is fine), but if provided, Start takes ownership of buf. +func (b *Builder) StartWithoutCompression(buf []byte, h Header) { + *b = Builder{msg: buf} + b.header.id, b.header.bits = h.pack() + if cap(b.msg) < headerLen { + b.msg = make([]byte, 0, packStartingCap) + } + b.msg = b.msg[:headerLen] + b.section = sectionHeader +} + +func (b *Builder) startCheck(s section) error { + if b.section <= sectionNotStarted { + return ErrNotStarted + } + if b.section > s { + return ErrSectionDone + } + return nil +} + +// StartQuestions prepares the builder for packing Questions. +func (b *Builder) StartQuestions() error { + if err := b.startCheck(sectionQuestions); err != nil { + return err + } + b.section = sectionQuestions + return nil +} + +// StartAnswers prepares the builder for packing Answers. +func (b *Builder) StartAnswers() error { + if err := b.startCheck(sectionAnswers); err != nil { + return err + } + b.section = sectionAnswers + return nil +} + +// StartAuthorities prepares the builder for packing Authorities. +func (b *Builder) StartAuthorities() error { + if err := b.startCheck(sectionAuthorities); err != nil { + return err + } + b.section = sectionAuthorities + return nil +} + +// StartAdditionals prepares the builder for packing Additionals. +func (b *Builder) StartAdditionals() error { + if err := b.startCheck(sectionAdditionals); err != nil { + return err + } + b.section = sectionAdditionals + return nil +} + +func (b *Builder) incrementSectionCount() error { + var count *uint16 + var err error + switch b.section { + case sectionQuestions: + count = &b.header.questions + err = errTooManyQuestions + case sectionAnswers: + count = &b.header.answers + err = errTooManyAnswers + case sectionAuthorities: + count = &b.header.authorities + err = errTooManyAuthorities + case sectionAdditionals: + count = &b.header.additionals + err = errTooManyAdditionals + } + if *count == ^uint16(0) { + return err + } + *count++ + return nil +} + +// Question adds a single Question. +func (b *Builder) Question(q Question) error { + if b.section < sectionQuestions { + return ErrNotStarted + } + if b.section > sectionQuestions { + return ErrSectionDone + } + msg, err := q.pack(b.msg, b.compression) + if err != nil { + return err + } + if err := b.incrementSectionCount(); err != nil { + return err + } + b.msg = msg + return nil +} + +func (b *Builder) checkResourceSection() error { + if b.section < sectionAnswers { + return ErrNotStarted + } + if b.section > sectionAdditionals { + return ErrSectionDone + } + return nil +} + +// CNAMEResource adds a single CNAMEResource. +func (b *Builder) CNAMEResource(h ResourceHeader, r CNAMEResource) error { + if err := b.checkResourceSection(); err != nil { + return err + } + h.Type = r.realType() + msg, length, err := h.pack(b.msg, b.compression) + if err != nil { + return &nestedError{"ResourceHeader", err} + } + preLen := len(msg) + if msg, err = r.pack(msg, b.compression); err != nil { + return &nestedError{"CNAMEResource body", err} + } + if err := h.fixLen(msg, length, preLen); err != nil { + return err + } + if err := b.incrementSectionCount(); err != nil { + return err + } + b.msg = msg + return nil +} + +// MXResource adds a single MXResource. +func (b *Builder) MXResource(h ResourceHeader, r MXResource) error { + if err := b.checkResourceSection(); err != nil { + return err + } + h.Type = r.realType() + msg, length, err := h.pack(b.msg, b.compression) + if err != nil { + return &nestedError{"ResourceHeader", err} + } + preLen := len(msg) + if msg, err = r.pack(msg, b.compression); err != nil { + return &nestedError{"MXResource body", err} + } + if err := h.fixLen(msg, length, preLen); err != nil { + return err + } + if err := b.incrementSectionCount(); err != nil { + return err + } + b.msg = msg + return nil +} + +// NSResource adds a single NSResource. +func (b *Builder) NSResource(h ResourceHeader, r NSResource) error { + if err := b.checkResourceSection(); err != nil { + return err + } + h.Type = r.realType() + msg, length, err := h.pack(b.msg, b.compression) + if err != nil { + return &nestedError{"ResourceHeader", err} + } + preLen := len(msg) + if msg, err = r.pack(msg, b.compression); err != nil { + return &nestedError{"NSResource body", err} + } + if err := h.fixLen(msg, length, preLen); err != nil { + return err + } + if err := b.incrementSectionCount(); err != nil { + return err + } + b.msg = msg + return nil +} + +// PTRResource adds a single PTRResource. +func (b *Builder) PTRResource(h ResourceHeader, r PTRResource) error { + if err := b.checkResourceSection(); err != nil { + return err + } + h.Type = r.realType() + msg, length, err := h.pack(b.msg, b.compression) + if err != nil { + return &nestedError{"ResourceHeader", err} + } + preLen := len(msg) + if msg, err = r.pack(msg, b.compression); err != nil { + return &nestedError{"PTRResource body", err} + } + if err := h.fixLen(msg, length, preLen); err != nil { + return err + } + if err := b.incrementSectionCount(); err != nil { + return err + } + b.msg = msg + return nil +} + +// SOAResource adds a single SOAResource. +func (b *Builder) SOAResource(h ResourceHeader, r SOAResource) error { + if err := b.checkResourceSection(); err != nil { + return err + } + h.Type = r.realType() + msg, length, err := h.pack(b.msg, b.compression) + if err != nil { + return &nestedError{"ResourceHeader", err} + } + preLen := len(msg) + if msg, err = r.pack(msg, b.compression); err != nil { + return &nestedError{"SOAResource body", err} + } + if err := h.fixLen(msg, length, preLen); err != nil { + return err + } + if err := b.incrementSectionCount(); err != nil { + return err + } + b.msg = msg + return nil +} + +// TXTResource adds a single TXTResource. +func (b *Builder) TXTResource(h ResourceHeader, r TXTResource) error { + if err := b.checkResourceSection(); err != nil { + return err + } + h.Type = r.realType() + msg, length, err := h.pack(b.msg, b.compression) + if err != nil { + return &nestedError{"ResourceHeader", err} + } + preLen := len(msg) + if msg, err = r.pack(msg, b.compression); err != nil { + return &nestedError{"TXTResource body", err} + } + if err := h.fixLen(msg, length, preLen); err != nil { + return err + } + if err := b.incrementSectionCount(); err != nil { + return err + } + b.msg = msg + return nil +} + +// SRVResource adds a single SRVResource. +func (b *Builder) SRVResource(h ResourceHeader, r SRVResource) error { + if err := b.checkResourceSection(); err != nil { + return err + } + h.Type = r.realType() + msg, length, err := h.pack(b.msg, b.compression) + if err != nil { + return &nestedError{"ResourceHeader", err} + } + preLen := len(msg) + if msg, err = r.pack(msg, b.compression); err != nil { + return &nestedError{"SRVResource body", err} + } + if err := h.fixLen(msg, length, preLen); err != nil { + return err + } + if err := b.incrementSectionCount(); err != nil { + return err + } + b.msg = msg + return nil +} + +// AResource adds a single AResource. +func (b *Builder) AResource(h ResourceHeader, r AResource) error { + if err := b.checkResourceSection(); err != nil { + return err + } + h.Type = r.realType() + msg, length, err := h.pack(b.msg, b.compression) + if err != nil { + return &nestedError{"ResourceHeader", err} + } + preLen := len(msg) + if msg, err = r.pack(msg, b.compression); err != nil { + return &nestedError{"AResource body", err} + } + if err := h.fixLen(msg, length, preLen); err != nil { + return err + } + if err := b.incrementSectionCount(); err != nil { + return err + } + b.msg = msg + return nil +} + +// AAAAResource adds a single AAAAResource. +func (b *Builder) AAAAResource(h ResourceHeader, r AAAAResource) error { + if err := b.checkResourceSection(); err != nil { + return err + } + h.Type = r.realType() + msg, length, err := h.pack(b.msg, b.compression) + if err != nil { + return &nestedError{"ResourceHeader", err} + } + preLen := len(msg) + if msg, err = r.pack(msg, b.compression); err != nil { + return &nestedError{"AAAAResource body", err} + } + if err := h.fixLen(msg, length, preLen); err != nil { + return err + } + if err := b.incrementSectionCount(); err != nil { + return err + } + b.msg = msg + return nil +} + +// Finish ends message building and generates a binary packet. +func (b *Builder) Finish() ([]byte, error) { + if b.section < sectionHeader { + return nil, ErrNotStarted + } + b.section = sectionDone + b.header.pack(b.msg[:0]) + return b.msg, nil +} + +// A ResourceHeader is the header of a DNS resource record. There are +// many types of DNS resource records, but they all share the same header. +type ResourceHeader struct { + // Name is the domain name for which this resource record pertains. + Name Name + + // Type is the type of DNS resource record. + // + // This field will be set automatically during packing. + Type Type + + // Class is the class of network to which this DNS resource record + // pertains. + Class Class + + // TTL is the length of time (measured in seconds) which this resource + // record is valid for (time to live). All Resources in a set should + // have the same TTL (RFC 2181 Section 5.2). + TTL uint32 + + // Length is the length of data in the resource record after the header. + // + // This field will be set automatically during packing. + Length uint16 +} + +// pack packs all of the fields in a ResourceHeader except for the length. The +// length bytes are returned as a slice so they can be filled in after the rest +// of the Resource has been packed. +func (h *ResourceHeader) pack(oldMsg []byte, compression map[string]int) (msg []byte, length []byte, err error) { + msg = oldMsg + if msg, err = h.Name.pack(msg, compression); err != nil { + return oldMsg, nil, &nestedError{"Name", err} + } + msg = packType(msg, h.Type) + msg = packClass(msg, h.Class) + msg = packUint32(msg, h.TTL) + lenBegin := len(msg) + msg = packUint16(msg, h.Length) + return msg, msg[lenBegin : lenBegin+uint16Len], nil +} + +func (h *ResourceHeader) unpack(msg []byte, off int) (int, error) { + newOff := off + var err error + if newOff, err = h.Name.unpack(msg, newOff); err != nil { + return off, &nestedError{"Name", err} + } + if h.Type, newOff, err = unpackType(msg, newOff); err != nil { + return off, &nestedError{"Type", err} + } + if h.Class, newOff, err = unpackClass(msg, newOff); err != nil { + return off, &nestedError{"Class", err} + } + if h.TTL, newOff, err = unpackUint32(msg, newOff); err != nil { + return off, &nestedError{"TTL", err} + } + if h.Length, newOff, err = unpackUint16(msg, newOff); err != nil { + return off, &nestedError{"Length", err} + } + return newOff, nil +} + +func (h *ResourceHeader) fixLen(msg []byte, length []byte, preLen int) error { + conLen := len(msg) - preLen + if conLen > int(^uint16(0)) { + return errResTooLong + } + + // Fill in the length now that we know how long the content is. + packUint16(length[:0], uint16(conLen)) + h.Length = uint16(conLen) + + return nil +} + +func skipResource(msg []byte, off int) (int, error) { + newOff, err := skipName(msg, off) + if err != nil { + return off, &nestedError{"Name", err} + } + if newOff, err = skipType(msg, newOff); err != nil { + return off, &nestedError{"Type", err} + } + if newOff, err = skipClass(msg, newOff); err != nil { + return off, &nestedError{"Class", err} + } + if newOff, err = skipUint32(msg, newOff); err != nil { + return off, &nestedError{"TTL", err} + } + length, newOff, err := unpackUint16(msg, newOff) + if err != nil { + return off, &nestedError{"Length", err} + } + if newOff += int(length); newOff > len(msg) { + return off, errResourceLen + } + return newOff, nil +} + +func packUint16(msg []byte, field uint16) []byte { + return append(msg, byte(field>>8), byte(field)) +} + +func unpackUint16(msg []byte, off int) (uint16, int, error) { + if off+uint16Len > len(msg) { + return 0, off, errBaseLen + } + return uint16(msg[off])<<8 | uint16(msg[off+1]), off + uint16Len, nil +} + +func skipUint16(msg []byte, off int) (int, error) { + if off+uint16Len > len(msg) { + return off, errBaseLen + } + return off + uint16Len, nil +} + +func packType(msg []byte, field Type) []byte { + return packUint16(msg, uint16(field)) +} + +func unpackType(msg []byte, off int) (Type, int, error) { + t, o, err := unpackUint16(msg, off) + return Type(t), o, err +} + +func skipType(msg []byte, off int) (int, error) { + return skipUint16(msg, off) +} + +func packClass(msg []byte, field Class) []byte { + return packUint16(msg, uint16(field)) +} + +func unpackClass(msg []byte, off int) (Class, int, error) { + c, o, err := unpackUint16(msg, off) + return Class(c), o, err +} + +func skipClass(msg []byte, off int) (int, error) { + return skipUint16(msg, off) +} + +func packUint32(msg []byte, field uint32) []byte { + return append( + msg, + byte(field>>24), + byte(field>>16), + byte(field>>8), + byte(field), + ) +} + +func unpackUint32(msg []byte, off int) (uint32, int, error) { + if off+uint32Len > len(msg) { + return 0, off, errBaseLen + } + v := uint32(msg[off])<<24 | uint32(msg[off+1])<<16 | uint32(msg[off+2])<<8 | uint32(msg[off+3]) + return v, off + uint32Len, nil +} + +func skipUint32(msg []byte, off int) (int, error) { + if off+uint32Len > len(msg) { + return off, errBaseLen + } + return off + uint32Len, nil +} + +func packText(msg []byte, field string) []byte { + for len(field) > 0 { + l := len(field) + if l > 255 { + l = 255 + } + msg = append(msg, byte(l)) + msg = append(msg, field[:l]...) + field = field[l:] + } + return msg +} + +func unpackText(msg []byte, off int) (string, int, error) { + if off >= len(msg) { + return "", off, errBaseLen + } + beginOff := off + 1 + endOff := beginOff + int(msg[off]) + if endOff > len(msg) { + return "", off, errCalcLen + } + return string(msg[beginOff:endOff]), endOff, nil +} + +func skipText(msg []byte, off int) (int, error) { + if off >= len(msg) { + return off, errBaseLen + } + endOff := off + 1 + int(msg[off]) + if endOff > len(msg) { + return off, errCalcLen + } + return endOff, nil +} + +func packBytes(msg []byte, field []byte) []byte { + return append(msg, field...) +} + +func unpackBytes(msg []byte, off int, field []byte) (int, error) { + newOff := off + len(field) + if newOff > len(msg) { + return off, errBaseLen + } + copy(field, msg[off:newOff]) + return newOff, nil +} + +func skipBytes(msg []byte, off int, field []byte) (int, error) { + newOff := off + len(field) + if newOff > len(msg) { + return off, errBaseLen + } + return newOff, nil +} + +const nameLen = 255 + +// A Name is a non-encoded domain name. It is used instead of strings to avoid +// allocations. +type Name struct { + Data [nameLen]byte + Length uint8 +} + +// NewName creates a new Name from a string. +func NewName(name string) (Name, error) { + if len([]byte(name)) > nameLen { + return Name{}, errCalcLen + } + n := Name{Length: uint8(len(name))} + copy(n.Data[:], []byte(name)) + return n, nil +} + +func (n Name) String() string { + return string(n.Data[:n.Length]) +} + +// pack packs a domain name. +// +// Domain names are a sequence of counted strings split at the dots. They end +// with a zero-length string. Compression can be used to reuse domain suffixes. +// +// The compression map will be updated with new domain suffixes. If compression +// is nil, compression will not be used. +func (n *Name) pack(msg []byte, compression map[string]int) ([]byte, error) { + oldMsg := msg + + // Add a trailing dot to canonicalize name. + if n.Length == 0 || n.Data[n.Length-1] != '.' { + return oldMsg, errNonCanonicalName + } + + // Allow root domain. + if n.Data[0] == '.' && n.Length == 1 { + return append(msg, 0), nil + } + + // Emit sequence of counted strings, chopping at dots. + for i, begin := 0, 0; i < int(n.Length); i++ { + // Check for the end of the segment. + if n.Data[i] == '.' { + // The two most significant bits have special meaning. + // It isn't allowed for segments to be long enough to + // need them. + if i-begin >= 1<<6 { + return oldMsg, errSegTooLong + } + + // Segments must have a non-zero length. + if i-begin == 0 { + return oldMsg, errZeroSegLen + } + + msg = append(msg, byte(i-begin)) + + for j := begin; j < i; j++ { + msg = append(msg, n.Data[j]) + } + + begin = i + 1 + continue + } + + // We can only compress domain suffixes starting with a new + // segment. A pointer is two bytes with the two most significant + // bits set to 1 to indicate that it is a pointer. + if (i == 0 || n.Data[i-1] == '.') && compression != nil { + if ptr, ok := compression[string(n.Data[i:])]; ok { + // Hit. Emit a pointer instead of the rest of + // the domain. + return append(msg, byte(ptr>>8|0xC0), byte(ptr)), nil + } + + // Miss. Add the suffix to the compression table if the + // offset can be stored in the available 14 bytes. + if len(msg) <= int(^uint16(0)>>2) { + compression[string(n.Data[i:])] = len(msg) + } + } + } + return append(msg, 0), nil +} + +// unpack unpacks a domain name. +func (n *Name) unpack(msg []byte, off int) (int, error) { + // currOff is the current working offset. + currOff := off + + // newOff is the offset where the next record will start. Pointers lead + // to data that belongs to other names and thus doesn't count towards to + // the usage of this name. + newOff := off + + // ptr is the number of pointers followed. + var ptr int + + // Name is a slice representation of the name data. + name := n.Data[:0] + +Loop: + for { + if currOff >= len(msg) { + return off, errBaseLen + } + c := int(msg[currOff]) + currOff++ + switch c & 0xC0 { + case 0x00: // String segment + if c == 0x00 { + // A zero length signals the end of the name. + break Loop + } + endOff := currOff + c + if endOff > len(msg) { + return off, errCalcLen + } + name = append(name, msg[currOff:endOff]...) + name = append(name, '.') + currOff = endOff + case 0xC0: // Pointer + if currOff >= len(msg) { + return off, errInvalidPtr + } + c1 := msg[currOff] + currOff++ + if ptr == 0 { + newOff = currOff + } + // Don't follow too many pointers, maybe there's a loop. + if ptr++; ptr > 10 { + return off, errTooManyPtr + } + currOff = (c^0xC0)<<8 | int(c1) + default: + // Prefixes 0x80 and 0x40 are reserved. + return off, errReserved + } + } + if len(name) == 0 { + name = append(name, '.') + } + if len(name) > len(n.Data) { + return off, errCalcLen + } + n.Length = uint8(len(name)) + if ptr == 0 { + newOff = currOff + } + return newOff, nil +} + +func skipName(msg []byte, off int) (int, error) { + // newOff is the offset where the next record will start. Pointers lead + // to data that belongs to other names and thus doesn't count towards to + // the usage of this name. + newOff := off + +Loop: + for { + if newOff >= len(msg) { + return off, errBaseLen + } + c := int(msg[newOff]) + newOff++ + switch c & 0xC0 { + case 0x00: + if c == 0x00 { + // A zero length signals the end of the name. + break Loop + } + // literal string + newOff += c + if newOff > len(msg) { + return off, errCalcLen + } + case 0xC0: + // Pointer to somewhere else in msg. + + // Pointers are two bytes. + newOff++ + + // Don't follow the pointer as the data here has ended. + break Loop + default: + // Prefixes 0x80 and 0x40 are reserved. + return off, errReserved + } + } + + return newOff, nil +} + +// A Question is a DNS query. +type Question struct { + Name Name + Type Type + Class Class +} + +func (q *Question) pack(msg []byte, compression map[string]int) ([]byte, error) { + msg, err := q.Name.pack(msg, compression) + if err != nil { + return msg, &nestedError{"Name", err} + } + msg = packType(msg, q.Type) + return packClass(msg, q.Class), nil +} + +func unpackResourceBody(msg []byte, off int, hdr ResourceHeader) (ResourceBody, int, error) { + var ( + r ResourceBody + err error + name string + ) + switch hdr.Type { + case TypeA: + var rb AResource + rb, err = unpackAResource(msg, off) + r = &rb + name = "A" + case TypeNS: + var rb NSResource + rb, err = unpackNSResource(msg, off) + r = &rb + name = "NS" + case TypeCNAME: + var rb CNAMEResource + rb, err = unpackCNAMEResource(msg, off) + r = &rb + name = "CNAME" + case TypeSOA: + var rb SOAResource + rb, err = unpackSOAResource(msg, off) + r = &rb + name = "SOA" + case TypePTR: + var rb PTRResource + rb, err = unpackPTRResource(msg, off) + r = &rb + name = "PTR" + case TypeMX: + var rb MXResource + rb, err = unpackMXResource(msg, off) + r = &rb + name = "MX" + case TypeTXT: + var rb TXTResource + rb, err = unpackTXTResource(msg, off, hdr.Length) + r = &rb + name = "TXT" + case TypeAAAA: + var rb AAAAResource + rb, err = unpackAAAAResource(msg, off) + r = &rb + name = "AAAA" + case TypeSRV: + var rb SRVResource + rb, err = unpackSRVResource(msg, off) + r = &rb + name = "SRV" + } + if err != nil { + return nil, off, &nestedError{name + " record", err} + } + if r == nil { + return nil, off, errors.New("invalid resource type: " + string(hdr.Type+'0')) + } + return r, off + int(hdr.Length), nil +} + +// A CNAMEResource is a CNAME Resource record. +type CNAMEResource struct { + CNAME Name +} + +func (r *CNAMEResource) realType() Type { + return TypeCNAME +} + +func (r *CNAMEResource) pack(msg []byte, compression map[string]int) ([]byte, error) { + return r.CNAME.pack(msg, compression) +} + +func unpackCNAMEResource(msg []byte, off int) (CNAMEResource, error) { + var cname Name + if _, err := cname.unpack(msg, off); err != nil { + return CNAMEResource{}, err + } + return CNAMEResource{cname}, nil +} + +// An MXResource is an MX Resource record. +type MXResource struct { + Pref uint16 + MX Name +} + +func (r *MXResource) realType() Type { + return TypeMX +} + +func (r *MXResource) pack(msg []byte, compression map[string]int) ([]byte, error) { + oldMsg := msg + msg = packUint16(msg, r.Pref) + msg, err := r.MX.pack(msg, compression) + if err != nil { + return oldMsg, &nestedError{"MXResource.MX", err} + } + return msg, nil +} + +func unpackMXResource(msg []byte, off int) (MXResource, error) { + pref, off, err := unpackUint16(msg, off) + if err != nil { + return MXResource{}, &nestedError{"Pref", err} + } + var mx Name + if _, err := mx.unpack(msg, off); err != nil { + return MXResource{}, &nestedError{"MX", err} + } + return MXResource{pref, mx}, nil +} + +// An NSResource is an NS Resource record. +type NSResource struct { + NS Name +} + +func (r *NSResource) realType() Type { + return TypeNS +} + +func (r *NSResource) pack(msg []byte, compression map[string]int) ([]byte, error) { + return r.NS.pack(msg, compression) +} + +func unpackNSResource(msg []byte, off int) (NSResource, error) { + var ns Name + if _, err := ns.unpack(msg, off); err != nil { + return NSResource{}, err + } + return NSResource{ns}, nil +} + +// A PTRResource is a PTR Resource record. +type PTRResource struct { + PTR Name +} + +func (r *PTRResource) realType() Type { + return TypePTR +} + +func (r *PTRResource) pack(msg []byte, compression map[string]int) ([]byte, error) { + return r.PTR.pack(msg, compression) +} + +func unpackPTRResource(msg []byte, off int) (PTRResource, error) { + var ptr Name + if _, err := ptr.unpack(msg, off); err != nil { + return PTRResource{}, err + } + return PTRResource{ptr}, nil +} + +// An SOAResource is an SOA Resource record. +type SOAResource struct { + NS Name + MBox Name + Serial uint32 + Refresh uint32 + Retry uint32 + Expire uint32 + + // MinTTL the is the default TTL of Resources records which did not + // contain a TTL value and the TTL of negative responses. (RFC 2308 + // Section 4) + MinTTL uint32 +} + +func (r *SOAResource) realType() Type { + return TypeSOA +} + +func (r *SOAResource) pack(msg []byte, compression map[string]int) ([]byte, error) { + oldMsg := msg + msg, err := r.NS.pack(msg, compression) + if err != nil { + return oldMsg, &nestedError{"SOAResource.NS", err} + } + msg, err = r.MBox.pack(msg, compression) + if err != nil { + return oldMsg, &nestedError{"SOAResource.MBox", err} + } + msg = packUint32(msg, r.Serial) + msg = packUint32(msg, r.Refresh) + msg = packUint32(msg, r.Retry) + msg = packUint32(msg, r.Expire) + return packUint32(msg, r.MinTTL), nil +} + +func unpackSOAResource(msg []byte, off int) (SOAResource, error) { + var ns Name + off, err := ns.unpack(msg, off) + if err != nil { + return SOAResource{}, &nestedError{"NS", err} + } + var mbox Name + if off, err = mbox.unpack(msg, off); err != nil { + return SOAResource{}, &nestedError{"MBox", err} + } + serial, off, err := unpackUint32(msg, off) + if err != nil { + return SOAResource{}, &nestedError{"Serial", err} + } + refresh, off, err := unpackUint32(msg, off) + if err != nil { + return SOAResource{}, &nestedError{"Refresh", err} + } + retry, off, err := unpackUint32(msg, off) + if err != nil { + return SOAResource{}, &nestedError{"Retry", err} + } + expire, off, err := unpackUint32(msg, off) + if err != nil { + return SOAResource{}, &nestedError{"Expire", err} + } + minTTL, _, err := unpackUint32(msg, off) + if err != nil { + return SOAResource{}, &nestedError{"MinTTL", err} + } + return SOAResource{ns, mbox, serial, refresh, retry, expire, minTTL}, nil +} + +// A TXTResource is a TXT Resource record. +type TXTResource struct { + Txt string // Not a domain name. +} + +func (r *TXTResource) realType() Type { + return TypeTXT +} + +func (r *TXTResource) pack(msg []byte, compression map[string]int) ([]byte, error) { + return packText(msg, r.Txt), nil +} + +func unpackTXTResource(msg []byte, off int, length uint16) (TXTResource, error) { + var txt string + for n := uint16(0); n < length; { + var t string + var err error + if t, off, err = unpackText(msg, off); err != nil { + return TXTResource{}, &nestedError{"text", err} + } + // Check if we got too many bytes. + if length-n < uint16(len(t))+1 { + return TXTResource{}, errCalcLen + } + n += uint16(len(t)) + 1 + txt += t + } + return TXTResource{txt}, nil +} + +// An SRVResource is an SRV Resource record. +type SRVResource struct { + Priority uint16 + Weight uint16 + Port uint16 + Target Name // Not compressed as per RFC 2782. +} + +func (r *SRVResource) realType() Type { + return TypeSRV +} + +func (r *SRVResource) pack(msg []byte, compression map[string]int) ([]byte, error) { + oldMsg := msg + msg = packUint16(msg, r.Priority) + msg = packUint16(msg, r.Weight) + msg = packUint16(msg, r.Port) + msg, err := r.Target.pack(msg, nil) + if err != nil { + return oldMsg, &nestedError{"SRVResource.Target", err} + } + return msg, nil +} + +func unpackSRVResource(msg []byte, off int) (SRVResource, error) { + priority, off, err := unpackUint16(msg, off) + if err != nil { + return SRVResource{}, &nestedError{"Priority", err} + } + weight, off, err := unpackUint16(msg, off) + if err != nil { + return SRVResource{}, &nestedError{"Weight", err} + } + port, off, err := unpackUint16(msg, off) + if err != nil { + return SRVResource{}, &nestedError{"Port", err} + } + var target Name + if _, err := target.unpack(msg, off); err != nil { + return SRVResource{}, &nestedError{"Target", err} + } + return SRVResource{priority, weight, port, target}, nil +} + +// An AResource is an A Resource record. +type AResource struct { + A [4]byte +} + +func (r *AResource) realType() Type { + return TypeA +} + +func (r *AResource) pack(msg []byte, compression map[string]int) ([]byte, error) { + return packBytes(msg, r.A[:]), nil +} + +func unpackAResource(msg []byte, off int) (AResource, error) { + var a [4]byte + if _, err := unpackBytes(msg, off, a[:]); err != nil { + return AResource{}, err + } + return AResource{a}, nil +} + +// An AAAAResource is an AAAA Resource record. +type AAAAResource struct { + AAAA [16]byte +} + +func (r *AAAAResource) realType() Type { + return TypeAAAA +} + +func (r *AAAAResource) pack(msg []byte, compression map[string]int) ([]byte, error) { + return packBytes(msg, r.AAAA[:]), nil +} + +func unpackAAAAResource(msg []byte, off int) (AAAAResource, error) { + var aaaa [16]byte + if _, err := unpackBytes(msg, off, aaaa[:]); err != nil { + return AAAAResource{}, err + } + return AAAAResource{aaaa}, nil +} diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/dns/dnsmessage/message_test.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/dns/dnsmessage/message_test.go new file mode 100644 index 000000000..2bb763420 --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/dns/dnsmessage/message_test.go @@ -0,0 +1,1141 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package dnsmessage + +import ( + "bytes" + "fmt" + "reflect" + "testing" +) + +func mustNewName(name string) Name { + n, err := NewName(name) + if err != nil { + panic(err) + } + return n +} + +func (m *Message) String() string { + s := fmt.Sprintf("Message: %#v\n", &m.Header) + if len(m.Questions) > 0 { + s += "-- Questions\n" + for _, q := range m.Questions { + s += fmt.Sprintf("%#v\n", q) + } + } + if len(m.Answers) > 0 { + s += "-- Answers\n" + for _, a := range m.Answers { + s += fmt.Sprintf("%#v\n", a) + } + } + if len(m.Authorities) > 0 { + s += "-- Authorities\n" + for _, ns := range m.Authorities { + s += fmt.Sprintf("%#v\n", ns) + } + } + if len(m.Additionals) > 0 { + s += "-- Additionals\n" + for _, e := range m.Additionals { + s += fmt.Sprintf("%#v\n", e) + } + } + return s +} + +func TestNameString(t *testing.T) { + want := "foo" + name := mustNewName(want) + if got := fmt.Sprint(name); got != want { + t.Errorf("got fmt.Sprint(%#v) = %s, want = %s", name, got, want) + } +} + +func TestQuestionPackUnpack(t *testing.T) { + want := Question{ + Name: mustNewName("."), + Type: TypeA, + Class: ClassINET, + } + buf, err := want.pack(make([]byte, 1, 50), map[string]int{}) + if err != nil { + t.Fatal("Packing failed:", err) + } + var p Parser + p.msg = buf + p.header.questions = 1 + p.section = sectionQuestions + p.off = 1 + got, err := p.Question() + if err != nil { + t.Fatalf("Unpacking failed: %v\n%s", err, string(buf[1:])) + } + if p.off != len(buf) { + t.Errorf("Unpacked different amount than packed: got n = %d, want = %d", p.off, len(buf)) + } + if !reflect.DeepEqual(got, want) { + t.Errorf("Got = %+v, want = %+v", got, want) + } +} + +func TestName(t *testing.T) { + tests := []string{ + "", + ".", + "google..com", + "google.com", + "google..com.", + "google.com.", + ".google.com.", + "www..google.com.", + "www.google.com.", + } + + for _, test := range tests { + n, err := NewName(test) + if err != nil { + t.Errorf("Creating name for %q: %v", test, err) + continue + } + if ns := n.String(); ns != test { + t.Errorf("Got %#v.String() = %q, want = %q", n, ns, test) + continue + } + } +} + +func TestNamePackUnpack(t *testing.T) { + tests := []struct { + in string + want string + err error + }{ + {"", "", errNonCanonicalName}, + {".", ".", nil}, + {"google..com", "", errNonCanonicalName}, + {"google.com", "", errNonCanonicalName}, + {"google..com.", "", errZeroSegLen}, + {"google.com.", "google.com.", nil}, + {".google.com.", "", errZeroSegLen}, + {"www..google.com.", "", errZeroSegLen}, + {"www.google.com.", "www.google.com.", nil}, + } + + for _, test := range tests { + in := mustNewName(test.in) + want := mustNewName(test.want) + buf, err := in.pack(make([]byte, 0, 30), map[string]int{}) + if err != test.err { + t.Errorf("Packing of %q: got err = %v, want err = %v", test.in, err, test.err) + continue + } + if test.err != nil { + continue + } + var got Name + n, err := got.unpack(buf, 0) + if err != nil { + t.Errorf("Unpacking for %q failed: %v", test.in, err) + continue + } + if n != len(buf) { + t.Errorf( + "Unpacked different amount than packed for %q: got n = %d, want = %d", + test.in, + n, + len(buf), + ) + } + if got != want { + t.Errorf("Unpacking packing of %q: got = %#v, want = %#v", test.in, got, want) + } + } +} + +func checkErrorPrefix(err error, prefix string) bool { + e, ok := err.(*nestedError) + return ok && e.s == prefix +} + +func TestHeaderUnpackError(t *testing.T) { + wants := []string{ + "id", + "bits", + "questions", + "answers", + "authorities", + "additionals", + } + var buf []byte + var h header + for _, want := range wants { + n, err := h.unpack(buf, 0) + if n != 0 || !checkErrorPrefix(err, want) { + t.Errorf("got h.unpack([%d]byte, 0) = %d, %v, want = 0, %s", len(buf), n, err, want) + } + buf = append(buf, 0, 0) + } +} + +func TestParserStart(t *testing.T) { + const want = "unpacking header" + var p Parser + for i := 0; i <= 1; i++ { + _, err := p.Start([]byte{}) + if !checkErrorPrefix(err, want) { + t.Errorf("got p.Start(nil) = _, %v, want = _, %s", err, want) + } + } +} + +func TestResourceNotStarted(t *testing.T) { + tests := []struct { + name string + fn func(*Parser) error + }{ + {"CNAMEResource", func(p *Parser) error { _, err := p.CNAMEResource(); return err }}, + {"MXResource", func(p *Parser) error { _, err := p.MXResource(); return err }}, + {"NSResource", func(p *Parser) error { _, err := p.NSResource(); return err }}, + {"PTRResource", func(p *Parser) error { _, err := p.PTRResource(); return err }}, + {"SOAResource", func(p *Parser) error { _, err := p.SOAResource(); return err }}, + {"TXTResource", func(p *Parser) error { _, err := p.TXTResource(); return err }}, + {"SRVResource", func(p *Parser) error { _, err := p.SRVResource(); return err }}, + {"AResource", func(p *Parser) error { _, err := p.AResource(); return err }}, + {"AAAAResource", func(p *Parser) error { _, err := p.AAAAResource(); return err }}, + } + + for _, test := range tests { + if err := test.fn(&Parser{}); err != ErrNotStarted { + t.Errorf("got _, %v = p.%s(), want = _, %v", err, test.name, ErrNotStarted) + } + } +} + +func TestDNSPackUnpack(t *testing.T) { + wants := []Message{ + { + Questions: []Question{ + { + Name: mustNewName("."), + Type: TypeAAAA, + Class: ClassINET, + }, + }, + Answers: []Resource{}, + Authorities: []Resource{}, + Additionals: []Resource{}, + }, + largeTestMsg(), + } + for i, want := range wants { + b, err := want.Pack() + if err != nil { + t.Fatalf("%d: packing failed: %v", i, err) + } + var got Message + err = got.Unpack(b) + if err != nil { + t.Fatalf("%d: unpacking failed: %v", i, err) + } + if !reflect.DeepEqual(got, want) { + t.Errorf("%d: got = %+v, want = %+v", i, &got, &want) + } + } +} + +func TestSkipAll(t *testing.T) { + msg := largeTestMsg() + buf, err := msg.Pack() + if err != nil { + t.Fatal("Packing large test message:", err) + } + var p Parser + if _, err := p.Start(buf); err != nil { + t.Fatal(err) + } + + tests := []struct { + name string + f func() error + }{ + {"SkipAllQuestions", p.SkipAllQuestions}, + {"SkipAllAnswers", p.SkipAllAnswers}, + {"SkipAllAuthorities", p.SkipAllAuthorities}, + {"SkipAllAdditionals", p.SkipAllAdditionals}, + } + for _, test := range tests { + for i := 1; i <= 3; i++ { + if err := test.f(); err != nil { + t.Errorf("Call #%d to %s(): %v", i, test.name, err) + } + } + } +} + +func TestSkipEach(t *testing.T) { + msg := smallTestMsg() + + buf, err := msg.Pack() + if err != nil { + t.Fatal("Packing test message:", err) + } + var p Parser + if _, err := p.Start(buf); err != nil { + t.Fatal(err) + } + + tests := []struct { + name string + f func() error + }{ + {"SkipQuestion", p.SkipQuestion}, + {"SkipAnswer", p.SkipAnswer}, + {"SkipAuthority", p.SkipAuthority}, + {"SkipAdditional", p.SkipAdditional}, + } + for _, test := range tests { + if err := test.f(); err != nil { + t.Errorf("First call: got %s() = %v, want = %v", test.name, err, nil) + } + if err := test.f(); err != ErrSectionDone { + t.Errorf("Second call: got %s() = %v, want = %v", test.name, err, ErrSectionDone) + } + } +} + +func TestSkipAfterRead(t *testing.T) { + msg := smallTestMsg() + + buf, err := msg.Pack() + if err != nil { + t.Fatal("Packing test message:", err) + } + var p Parser + if _, err := p.Start(buf); err != nil { + t.Fatal(err) + } + + tests := []struct { + name string + skip func() error + read func() error + }{ + {"Question", p.SkipQuestion, func() error { _, err := p.Question(); return err }}, + {"Answer", p.SkipAnswer, func() error { _, err := p.Answer(); return err }}, + {"Authority", p.SkipAuthority, func() error { _, err := p.Authority(); return err }}, + {"Additional", p.SkipAdditional, func() error { _, err := p.Additional(); return err }}, + } + for _, test := range tests { + if err := test.read(); err != nil { + t.Errorf("Got %s() = _, %v, want = _, %v", test.name, err, nil) + } + if err := test.skip(); err != ErrSectionDone { + t.Errorf("Got Skip%s() = %v, want = %v", test.name, err, ErrSectionDone) + } + } +} + +func TestSkipNotStarted(t *testing.T) { + var p Parser + + tests := []struct { + name string + f func() error + }{ + {"SkipAllQuestions", p.SkipAllQuestions}, + {"SkipAllAnswers", p.SkipAllAnswers}, + {"SkipAllAuthorities", p.SkipAllAuthorities}, + {"SkipAllAdditionals", p.SkipAllAdditionals}, + } + for _, test := range tests { + if err := test.f(); err != ErrNotStarted { + t.Errorf("Got %s() = %v, want = %v", test.name, err, ErrNotStarted) + } + } +} + +func TestTooManyRecords(t *testing.T) { + const recs = int(^uint16(0)) + 1 + tests := []struct { + name string + msg Message + want error + }{ + { + "Questions", + Message{ + Questions: make([]Question, recs), + }, + errTooManyQuestions, + }, + { + "Answers", + Message{ + Answers: make([]Resource, recs), + }, + errTooManyAnswers, + }, + { + "Authorities", + Message{ + Authorities: make([]Resource, recs), + }, + errTooManyAuthorities, + }, + { + "Additionals", + Message{ + Additionals: make([]Resource, recs), + }, + errTooManyAdditionals, + }, + } + + for _, test := range tests { + if _, got := test.msg.Pack(); got != test.want { + t.Errorf("Packing %d %s: got = %v, want = %v", recs, test.name, got, test.want) + } + } +} + +func TestVeryLongTxt(t *testing.T) { + want := Resource{ + ResourceHeader{ + Name: mustNewName("foo.bar.example.com."), + Type: TypeTXT, + Class: ClassINET, + }, + &TXTResource{loremIpsum}, + } + buf, err := want.pack(make([]byte, 0, 8000), map[string]int{}) + if err != nil { + t.Fatal("Packing failed:", err) + } + var got Resource + off, err := got.Header.unpack(buf, 0) + if err != nil { + t.Fatal("Unpacking ResourceHeader failed:", err) + } + body, n, err := unpackResourceBody(buf, off, got.Header) + if err != nil { + t.Fatal("Unpacking failed:", err) + } + got.Body = body + if n != len(buf) { + t.Errorf("Unpacked different amount than packed: got n = %d, want = %d", n, len(buf)) + } + if !reflect.DeepEqual(got, want) { + t.Errorf("Got = %#v, want = %#v", got, want) + } +} + +func TestStartError(t *testing.T) { + tests := []struct { + name string + fn func(*Builder) error + }{ + {"Questions", func(b *Builder) error { return b.StartQuestions() }}, + {"Answers", func(b *Builder) error { return b.StartAnswers() }}, + {"Authorities", func(b *Builder) error { return b.StartAuthorities() }}, + {"Additionals", func(b *Builder) error { return b.StartAdditionals() }}, + } + + envs := []struct { + name string + fn func() *Builder + want error + }{ + {"sectionNotStarted", func() *Builder { return &Builder{section: sectionNotStarted} }, ErrNotStarted}, + {"sectionDone", func() *Builder { return &Builder{section: sectionDone} }, ErrSectionDone}, + } + + for _, env := range envs { + for _, test := range tests { + if got := test.fn(env.fn()); got != env.want { + t.Errorf("got Builder{%s}.Start%s = %v, want = %v", env.name, test.name, got, env.want) + } + } + } +} + +func TestBuilderResourceError(t *testing.T) { + tests := []struct { + name string + fn func(*Builder) error + }{ + {"CNAMEResource", func(b *Builder) error { return b.CNAMEResource(ResourceHeader{}, CNAMEResource{}) }}, + {"MXResource", func(b *Builder) error { return b.MXResource(ResourceHeader{}, MXResource{}) }}, + {"NSResource", func(b *Builder) error { return b.NSResource(ResourceHeader{}, NSResource{}) }}, + {"PTRResource", func(b *Builder) error { return b.PTRResource(ResourceHeader{}, PTRResource{}) }}, + {"SOAResource", func(b *Builder) error { return b.SOAResource(ResourceHeader{}, SOAResource{}) }}, + {"TXTResource", func(b *Builder) error { return b.TXTResource(ResourceHeader{}, TXTResource{}) }}, + {"SRVResource", func(b *Builder) error { return b.SRVResource(ResourceHeader{}, SRVResource{}) }}, + {"AResource", func(b *Builder) error { return b.AResource(ResourceHeader{}, AResource{}) }}, + {"AAAAResource", func(b *Builder) error { return b.AAAAResource(ResourceHeader{}, AAAAResource{}) }}, + } + + envs := []struct { + name string + fn func() *Builder + want error + }{ + {"sectionNotStarted", func() *Builder { return &Builder{section: sectionNotStarted} }, ErrNotStarted}, + {"sectionHeader", func() *Builder { return &Builder{section: sectionHeader} }, ErrNotStarted}, + {"sectionQuestions", func() *Builder { return &Builder{section: sectionQuestions} }, ErrNotStarted}, + {"sectionDone", func() *Builder { return &Builder{section: sectionDone} }, ErrSectionDone}, + } + + for _, env := range envs { + for _, test := range tests { + if got := test.fn(env.fn()); got != env.want { + t.Errorf("got Builder{%s}.%s = %v, want = %v", env.name, test.name, got, env.want) + } + } + } +} + +func TestFinishError(t *testing.T) { + var b Builder + want := ErrNotStarted + if _, got := b.Finish(); got != want { + t.Errorf("got Builder{}.Finish() = %v, want = %v", got, want) + } +} + +func TestBuilder(t *testing.T) { + msg := largeTestMsg() + want, err := msg.Pack() + if err != nil { + t.Fatal("Packing without builder:", err) + } + + var b Builder + b.Start(nil, msg.Header) + + if err := b.StartQuestions(); err != nil { + t.Fatal("b.StartQuestions():", err) + } + for _, q := range msg.Questions { + if err := b.Question(q); err != nil { + t.Fatalf("b.Question(%#v): %v", q, err) + } + } + + if err := b.StartAnswers(); err != nil { + t.Fatal("b.StartAnswers():", err) + } + for _, a := range msg.Answers { + switch a.Header.Type { + case TypeA: + if err := b.AResource(a.Header, *a.Body.(*AResource)); err != nil { + t.Fatalf("b.AResource(%#v): %v", a, err) + } + case TypeNS: + if err := b.NSResource(a.Header, *a.Body.(*NSResource)); err != nil { + t.Fatalf("b.NSResource(%#v): %v", a, err) + } + case TypeCNAME: + if err := b.CNAMEResource(a.Header, *a.Body.(*CNAMEResource)); err != nil { + t.Fatalf("b.CNAMEResource(%#v): %v", a, err) + } + case TypeSOA: + if err := b.SOAResource(a.Header, *a.Body.(*SOAResource)); err != nil { + t.Fatalf("b.SOAResource(%#v): %v", a, err) + } + case TypePTR: + if err := b.PTRResource(a.Header, *a.Body.(*PTRResource)); err != nil { + t.Fatalf("b.PTRResource(%#v): %v", a, err) + } + case TypeMX: + if err := b.MXResource(a.Header, *a.Body.(*MXResource)); err != nil { + t.Fatalf("b.MXResource(%#v): %v", a, err) + } + case TypeTXT: + if err := b.TXTResource(a.Header, *a.Body.(*TXTResource)); err != nil { + t.Fatalf("b.TXTResource(%#v): %v", a, err) + } + case TypeAAAA: + if err := b.AAAAResource(a.Header, *a.Body.(*AAAAResource)); err != nil { + t.Fatalf("b.AAAAResource(%#v): %v", a, err) + } + case TypeSRV: + if err := b.SRVResource(a.Header, *a.Body.(*SRVResource)); err != nil { + t.Fatalf("b.SRVResource(%#v): %v", a, err) + } + } + } + + if err := b.StartAuthorities(); err != nil { + t.Fatal("b.StartAuthorities():", err) + } + for _, a := range msg.Authorities { + if err := b.NSResource(a.Header, *a.Body.(*NSResource)); err != nil { + t.Fatalf("b.NSResource(%#v): %v", a, err) + } + } + + if err := b.StartAdditionals(); err != nil { + t.Fatal("b.StartAdditionals():", err) + } + for _, a := range msg.Additionals { + if err := b.TXTResource(a.Header, *a.Body.(*TXTResource)); err != nil { + t.Fatalf("b.TXTResource(%#v): %v", a, err) + } + } + + got, err := b.Finish() + if err != nil { + t.Fatal("b.Finish():", err) + } + if !bytes.Equal(got, want) { + t.Fatalf("Got from Builder: %#v\nwant = %#v", got, want) + } +} + +func TestResourcePack(t *testing.T) { + for _, tt := range []struct { + m Message + err error + }{ + { + Message{ + Questions: []Question{ + { + Name: mustNewName("."), + Type: TypeAAAA, + Class: ClassINET, + }, + }, + Answers: []Resource{{ResourceHeader{}, nil}}, + }, + &nestedError{"packing Answer", errNilResouceBody}, + }, + { + Message{ + Questions: []Question{ + { + Name: mustNewName("."), + Type: TypeAAAA, + Class: ClassINET, + }, + }, + Authorities: []Resource{{ResourceHeader{}, (*NSResource)(nil)}}, + }, + &nestedError{"packing Authority", + &nestedError{"ResourceHeader", + &nestedError{"Name", errNonCanonicalName}, + }, + }, + }, + { + Message{ + Questions: []Question{ + { + Name: mustNewName("."), + Type: TypeA, + Class: ClassINET, + }, + }, + Additionals: []Resource{{ResourceHeader{}, nil}}, + }, + &nestedError{"packing Additional", errNilResouceBody}, + }, + } { + _, err := tt.m.Pack() + if !reflect.DeepEqual(err, tt.err) { + t.Errorf("got %v for %v; want %v", err, tt.m, tt.err) + } + } +} + +func BenchmarkParsing(b *testing.B) { + b.ReportAllocs() + + name := mustNewName("foo.bar.example.com.") + msg := Message{ + Header: Header{Response: true, Authoritative: true}, + Questions: []Question{ + { + Name: name, + Type: TypeA, + Class: ClassINET, + }, + }, + Answers: []Resource{ + { + ResourceHeader{ + Name: name, + Class: ClassINET, + }, + &AResource{[4]byte{}}, + }, + { + ResourceHeader{ + Name: name, + Class: ClassINET, + }, + &AAAAResource{[16]byte{}}, + }, + { + ResourceHeader{ + Name: name, + Class: ClassINET, + }, + &CNAMEResource{name}, + }, + { + ResourceHeader{ + Name: name, + Class: ClassINET, + }, + &NSResource{name}, + }, + }, + } + + buf, err := msg.Pack() + if err != nil { + b.Fatal("msg.Pack():", err) + } + + for i := 0; i < b.N; i++ { + var p Parser + if _, err := p.Start(buf); err != nil { + b.Fatal("p.Start(buf):", err) + } + + for { + _, err := p.Question() + if err == ErrSectionDone { + break + } + if err != nil { + b.Fatal("p.Question():", err) + } + } + + for { + h, err := p.AnswerHeader() + if err == ErrSectionDone { + break + } + if err != nil { + panic(err) + } + + switch h.Type { + case TypeA: + if _, err := p.AResource(); err != nil { + b.Fatal("p.AResource():", err) + } + case TypeAAAA: + if _, err := p.AAAAResource(); err != nil { + b.Fatal("p.AAAAResource():", err) + } + case TypeCNAME: + if _, err := p.CNAMEResource(); err != nil { + b.Fatal("p.CNAMEResource():", err) + } + case TypeNS: + if _, err := p.NSResource(); err != nil { + b.Fatal("p.NSResource():", err) + } + default: + b.Fatalf("unknown type: %T", h) + } + } + } +} + +func BenchmarkBuilding(b *testing.B) { + b.ReportAllocs() + + name := mustNewName("foo.bar.example.com.") + buf := make([]byte, 0, packStartingCap) + + for i := 0; i < b.N; i++ { + var bld Builder + bld.StartWithoutCompression(buf, Header{Response: true, Authoritative: true}) + + if err := bld.StartQuestions(); err != nil { + b.Fatal("bld.StartQuestions():", err) + } + q := Question{ + Name: name, + Type: TypeA, + Class: ClassINET, + } + if err := bld.Question(q); err != nil { + b.Fatalf("bld.Question(%+v): %v", q, err) + } + + hdr := ResourceHeader{ + Name: name, + Class: ClassINET, + } + if err := bld.StartAnswers(); err != nil { + b.Fatal("bld.StartQuestions():", err) + } + + ar := AResource{[4]byte{}} + if err := bld.AResource(hdr, ar); err != nil { + b.Fatalf("bld.AResource(%+v, %+v): %v", hdr, ar, err) + } + + aaar := AAAAResource{[16]byte{}} + if err := bld.AAAAResource(hdr, aaar); err != nil { + b.Fatalf("bld.AAAAResource(%+v, %+v): %v", hdr, aaar, err) + } + + cnr := CNAMEResource{name} + if err := bld.CNAMEResource(hdr, cnr); err != nil { + b.Fatalf("bld.CNAMEResource(%+v, %+v): %v", hdr, cnr, err) + } + + nsr := NSResource{name} + if err := bld.NSResource(hdr, nsr); err != nil { + b.Fatalf("bld.NSResource(%+v, %+v): %v", hdr, nsr, err) + } + + if _, err := bld.Finish(); err != nil { + b.Fatal("bld.Finish():", err) + } + } +} + +func smallTestMsg() Message { + name := mustNewName("example.com.") + return Message{ + Header: Header{Response: true, Authoritative: true}, + Questions: []Question{ + { + Name: name, + Type: TypeA, + Class: ClassINET, + }, + }, + Answers: []Resource{ + { + ResourceHeader{ + Name: name, + Type: TypeA, + Class: ClassINET, + }, + &AResource{[4]byte{127, 0, 0, 1}}, + }, + }, + Authorities: []Resource{ + { + ResourceHeader{ + Name: name, + Type: TypeA, + Class: ClassINET, + }, + &AResource{[4]byte{127, 0, 0, 1}}, + }, + }, + Additionals: []Resource{ + { + ResourceHeader{ + Name: name, + Type: TypeA, + Class: ClassINET, + }, + &AResource{[4]byte{127, 0, 0, 1}}, + }, + }, + } +} + +func BenchmarkPack(b *testing.B) { + msg := largeTestMsg() + + b.ReportAllocs() + + for i := 0; i < b.N; i++ { + if _, err := msg.Pack(); err != nil { + b.Fatal(err) + } + } +} + +func BenchmarkAppendPack(b *testing.B) { + msg := largeTestMsg() + buf := make([]byte, 0, packStartingCap) + + b.ReportAllocs() + + for i := 0; i < b.N; i++ { + if _, err := msg.AppendPack(buf[:0]); err != nil { + b.Fatal(err) + } + } +} + +func largeTestMsg() Message { + name := mustNewName("foo.bar.example.com.") + return Message{ + Header: Header{Response: true, Authoritative: true}, + Questions: []Question{ + { + Name: name, + Type: TypeA, + Class: ClassINET, + }, + }, + Answers: []Resource{ + { + ResourceHeader{ + Name: name, + Type: TypeA, + Class: ClassINET, + }, + &AResource{[4]byte{127, 0, 0, 1}}, + }, + { + ResourceHeader{ + Name: name, + Type: TypeA, + Class: ClassINET, + }, + &AResource{[4]byte{127, 0, 0, 2}}, + }, + { + ResourceHeader{ + Name: name, + Type: TypeAAAA, + Class: ClassINET, + }, + &AAAAResource{[16]byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}}, + }, + { + ResourceHeader{ + Name: name, + Type: TypeCNAME, + Class: ClassINET, + }, + &CNAMEResource{mustNewName("alias.example.com.")}, + }, + { + ResourceHeader{ + Name: name, + Type: TypeSOA, + Class: ClassINET, + }, + &SOAResource{ + NS: mustNewName("ns1.example.com."), + MBox: mustNewName("mb.example.com."), + Serial: 1, + Refresh: 2, + Retry: 3, + Expire: 4, + MinTTL: 5, + }, + }, + { + ResourceHeader{ + Name: name, + Type: TypePTR, + Class: ClassINET, + }, + &PTRResource{mustNewName("ptr.example.com.")}, + }, + { + ResourceHeader{ + Name: name, + Type: TypeMX, + Class: ClassINET, + }, + &MXResource{ + 7, + mustNewName("mx.example.com."), + }, + }, + { + ResourceHeader{ + Name: name, + Type: TypeSRV, + Class: ClassINET, + }, + &SRVResource{ + 8, + 9, + 11, + mustNewName("srv.example.com."), + }, + }, + }, + Authorities: []Resource{ + { + ResourceHeader{ + Name: name, + Type: TypeNS, + Class: ClassINET, + }, + &NSResource{mustNewName("ns1.example.com.")}, + }, + { + ResourceHeader{ + Name: name, + Type: TypeNS, + Class: ClassINET, + }, + &NSResource{mustNewName("ns2.example.com.")}, + }, + }, + Additionals: []Resource{ + { + ResourceHeader{ + Name: name, + Type: TypeTXT, + Class: ClassINET, + }, + &TXTResource{"So Long, and Thanks for All the Fish"}, + }, + { + ResourceHeader{ + Name: name, + Type: TypeTXT, + Class: ClassINET, + }, + &TXTResource{"Hamster Huey and the Gooey Kablooie"}, + }, + }, + } +} + +const loremIpsum = ` +Lorem ipsum dolor sit amet, nec enim antiopam id, an ullum choro +nonumes qui, pro eu debet honestatis mediocritatem. No alia enim eos, +magna signiferumque ex vis. Mei no aperiri dissentias, cu vel quas +regione. Malorum quaeque vim ut, eum cu semper aliquid invidunt, ei +nam ipsum assentior. + +Nostrum appellantur usu no, vis ex probatus adipiscing. Cu usu illum +facilis eleifend. Iusto conceptam complectitur vim id. Tale omnesque +no usu, ei oblique sadipscing vim. At nullam voluptua usu, mei laudem +reformidans et. Qui ei eros porro reformidans, ius suas veritus +torquatos ex. Mea te facer alterum consequat. + +Soleat torquatos democritum sed et, no mea congue appareat, facer +aliquam nec in. Has te ipsum tritani. At justo dicta option nec, movet +phaedrum ad nam. Ea detracto verterem liberavisse has, delectus +suscipiantur in mei. Ex nam meliore complectitur. Ut nam omnis +honestatis quaerendum, ea mea nihil affert detracto, ad vix rebum +mollis. + +Ut epicurei praesent neglegentur pri, prima fuisset intellegebat ad +vim. An habemus comprehensam usu, at enim dignissim pro. Eam reque +vivendum adipisci ea. Vel ne odio choro minimum. Sea admodum +dissentiet ex. Mundi tamquam evertitur ius cu. Homero postea iisque ut +pro, vel ne saepe senserit consetetur. + +Nulla utamur facilisis ius ea, in viderer diceret pertinax eum. Mei no +enim quodsi facilisi, ex sed aeterno appareat mediocritatem, eum +sententiae deterruisset ut. At suas timeam euismod cum, offendit +appareat interpretaris ne vix. Vel ea civibus albucius, ex vim quidam +accusata intellegebat, noluisse instructior sea id. Nec te nonumes +habemus appellantur, quis dignissim vituperata eu nam. + +At vix apeirian patrioque vituperatoribus, an usu agam assum. Debet +iisque an mea. Per eu dicant ponderum accommodare. Pri alienum +placerat senserit an, ne eum ferri abhorreant vituperatoribus. Ut mea +eligendi disputationi. Ius no tation everti impedit, ei magna quidam +mediocritatem pri. + +Legendos perpetua iracundia ne usu, no ius ullum epicurei intellegam, +ad modus epicuri lucilius eam. In unum quaerendum usu. Ne diam paulo +has, ea veri virtute sed. Alia honestatis conclusionemque mea eu, ut +iudico albucius his. + +Usu essent probatus eu, sed omnis dolor delicatissimi ex. No qui augue +dissentias dissentiet. Laudem recteque no usu, vel an velit noluisse, +an sed utinam eirmod appetere. Ne mea fuisset inimicus ocurreret. At +vis dicant abhorreant, utinam forensibus nec ne, mei te docendi +consequat. Brute inermis persecuti cum id. Ut ipsum munere propriae +usu, dicit graeco disputando id has. + +Eros dolore quaerendum nam ei. Timeam ornatus inciderint pro id. Nec +torquatos sadipscing ei, ancillae molestie per in. Malis principes duo +ea, usu liber postulant ei. + +Graece timeam voluptatibus eu eam. Alia probatus quo no, ea scripta +feugiat duo. Congue option meliore ex qui, noster invenire appellantur +ea vel. Eu exerci legendos vel. Consetetur repudiandae vim ut. Vix an +probo minimum, et nam illud falli tempor. + +Cum dico signiferumque eu. Sed ut regione maiorum, id veritus insolens +tacimates vix. Eu mel sint tamquam lucilius, duo no oporteat +tacimates. Atqui augue concludaturque vix ei, id mel utroque menandri. + +Ad oratio blandit aliquando pro. Vis et dolorum rationibus +philosophia, ad cum nulla molestie. Hinc fuisset adversarium eum et, +ne qui nisl verear saperet, vel te quaestio forensibus. Per odio +option delenit an. Alii placerat has no, in pri nihil platonem +cotidieque. Est ut elit copiosae scaevola, debet tollit maluisset sea +an. + +Te sea hinc debet pericula, liber ridens fabulas cu sed, quem mutat +accusam mea et. Elitr labitur albucius et pri, an labore feugait mel. +Velit zril melius usu ea. Ad stet putent interpretaris qui. Mel no +error volumus scripserit. In pro paulo iudico, quo ei dolorem +verterem, affert fabellas dissentiet ea vix. + +Vis quot deserunt te. Error aliquid detraxit eu usu, vis alia eruditi +salutatus cu. Est nostrud bonorum an, ei usu alii salutatus. Vel at +nisl primis, eum ex aperiri noluisse reformidans. Ad veri velit +utroque vis, ex equidem detraxit temporibus has. + +Inermis appareat usu ne. Eros placerat periculis mea ad, in dictas +pericula pro. Errem postulant at usu, ea nec amet ornatus mentitum. Ad +mazim graeco eum, vel ex percipit volutpat iudicabit, sit ne delicata +interesset. Mel sapientem prodesset abhorreant et, oblique suscipit +eam id. + +An maluisset disputando mea, vidit mnesarchum pri et. Malis insolens +inciderint no sea. Ea persius maluisset vix, ne vim appellantur +instructior, consul quidam definiebas pri id. Cum integre feugiat +pericula in, ex sed persius similique, mel ne natum dicit percipitur. + +Primis discere ne pri, errem putent definitionem at vis. Ei mel dolore +neglegentur, mei tincidunt percipitur ei. Pro ad simul integre +rationibus. Eu vel alii honestatis definitiones, mea no nonumy +reprehendunt. + +Dicta appareat legendos est cu. Eu vel congue dicunt omittam, no vix +adhuc minimum constituam, quot noluisse id mel. Eu quot sale mutat +duo, ex nisl munere invenire duo. Ne nec ullum utamur. Pro alterum +debitis nostrum no, ut vel aliquid vivendo. + +Aliquip fierent praesent quo ne, id sit audiam recusabo delicatissimi. +Usu postulant incorrupte cu. At pro dicit tibique intellegam, cibo +dolore impedit id eam, et aeque feugait assentior has. Quando sensibus +nec ex. Possit sensibus pri ad, unum mutat periculis cu vix. + +Mundi tibique vix te, duo simul partiendo qualisque id, est at vidit +sonet tempor. No per solet aeterno deseruisse. Petentium salutandi +definiebas pri cu. Munere vivendum est in. Ei justo congue eligendi +vis, modus offendit omittantur te mel. + +Integre voluptaria in qui, sit habemus tractatos constituam no. Utinam +melius conceptam est ne, quo in minimum apeirian delicata, ut ius +porro recusabo. Dicant expetenda vix no, ludus scripserit sed ex, eu +his modo nostro. Ut etiam sonet his, quodsi inciderint philosophia te +per. Nullam lobortis eu cum, vix an sonet efficiendi repudiandae. Vis +ad idque fabellas intellegebat. + +Eum commodo senserit conclusionemque ex. Sed forensibus sadipscing ut, +mei in facer delicata periculis, sea ne hinc putent cetero. Nec ne +alia corpora invenire, alia prima soleat te cum. Eleifend posidonium +nam at. + +Dolorum indoctum cu quo, ex dolor legendos recteque eam, cu pri zril +discere. Nec civibus officiis dissentiunt ex, est te liber ludus +elaboraret. Cum ea fabellas invenire. Ex vim nostrud eripuit +comprehensam, nam te inermis delectus, saepe inermis senserit. +` |