diff options
Diffstat (limited to 'pkg/tcpip')
-rw-r--r-- | pkg/tcpip/header/ndp_options.go | 213 | ||||
-rw-r--r-- | pkg/tcpip/header/ndp_test.go | 574 | ||||
-rw-r--r-- | pkg/tcpip/stack/ndp.go | 18 | ||||
-rw-r--r-- | pkg/tcpip/stack/ndp_test.go | 125 |
4 files changed, 930 insertions, 0 deletions
diff --git a/pkg/tcpip/header/ndp_options.go b/pkg/tcpip/header/ndp_options.go index 444e90820..5d3975c56 100644 --- a/pkg/tcpip/header/ndp_options.go +++ b/pkg/tcpip/header/ndp_options.go @@ -45,6 +45,10 @@ const ( // NDPRecursiveDNSServerOptionType is the type of the Recursive DNS // Server option, as per RFC 8106 section 5.1. NDPRecursiveDNSServerOptionType NDPOptionIdentifier = 25 + + // NDPDNSSearchListOptionType is the type of the DNS Search List option, + // as per RFC 8106 section 5.2. + NDPDNSSearchListOptionType = 31 ) const ( @@ -115,6 +119,27 @@ const ( // RFC 8106 section 5.3.1. minNDPRecursiveDNSServerBodySize = 22 + // ndpDNSSearchListLifetimeOffset is the start of the 4-byte + // Lifetime field within an NDPDNSSearchList. + ndpDNSSearchListLifetimeOffset = 2 + + // ndpDNSSearchListDomainNamesOffset is the start of the DNS search list + // domain names within an NDPDNSSearchList. + ndpDNSSearchListDomainNamesOffset = 6 + + // minNDPDNSSearchListBodySize is the minimum NDP DNS Search List option's + // body size when it contains at least one domain name, as per RFC 8106 + // section 5.3.1. + minNDPDNSSearchListBodySize = 14 + + // maxDomainNameLabelLength is the maximum length of a domain name + // label, as per RFC 1035 section 3.1. + maxDomainNameLabelLength = 63 + + // maxDomainNameLength is the maximum length of a domain name, including + // label AND label length octet, as per RFC 1035 section 3.1. + maxDomainNameLength = 255 + // lengthByteUnits is the multiplier factor for the Length field of an // NDP option. That is, the length field for NDP options is in units of // 8 octets, as per RFC 4861 section 4.6. @@ -224,6 +249,14 @@ func (i *NDPOptionIterator) Next() (NDPOption, bool, error) { return opt, false, nil + case NDPDNSSearchListOptionType: + opt := NDPDNSSearchList(body) + if err := opt.checkDomainNames(); err != nil { + return nil, true, err + } + + return opt, false, nil + default: // We do not yet recognize the option, just skip for // now. This is okay because RFC 4861 allows us to @@ -684,3 +717,183 @@ func (o NDPRecursiveDNSServer) iterAddresses(fn func(tcpip.Address)) error { return nil } + +// NDPDNSSearchList is the NDP DNS Search List option, as defined by +// RFC 8106 section 5.2. +type NDPDNSSearchList []byte + +// Type implements NDPOption.Type. +func (o NDPDNSSearchList) Type() NDPOptionIdentifier { + return NDPDNSSearchListOptionType +} + +// Length implements NDPOption.Length. +func (o NDPDNSSearchList) Length() int { + return len(o) +} + +// serializeInto implements NDPOption.serializeInto. +func (o NDPDNSSearchList) serializeInto(b []byte) int { + used := copy(b, o) + + // Zero out the reserved bytes that are before the Lifetime field. + for i := 0; i < ndpDNSSearchListLifetimeOffset; i++ { + b[i] = 0 + } + + return used +} + +// String implements fmt.Stringer.String. +func (o NDPDNSSearchList) String() string { + lt := o.Lifetime() + domainNames, err := o.DomainNames() + if err != nil { + return fmt.Sprintf("%T([] valid for %s; err = %s)", o, lt, err) + } + return fmt.Sprintf("%T(%s valid for %s)", o, domainNames, lt) +} + +// Lifetime returns the length of time that the DNS search list of domain names +// in this option may be used for name resolution. +// +// Note, a value of 0 implies the domain names should no longer be used, +// and a value of infinity/forever is represented by NDPInfiniteLifetime. +func (o NDPDNSSearchList) Lifetime() time.Duration { + // The field is the time in seconds, as per RFC 8106 section 5.1. + return time.Second * time.Duration(binary.BigEndian.Uint32(o[ndpDNSSearchListLifetimeOffset:])) +} + +// DomainNames returns a DNS search list of domain names. +// +// DomainNames will parse the backing buffer as outlined by RFC 1035 section +// 3.1 and return a list of strings, with all domain names in lower case. +func (o NDPDNSSearchList) DomainNames() ([]string, error) { + var domainNames []string + return domainNames, o.iterDomainNames(func(domainName string) { domainNames = append(domainNames, domainName) }) +} + +// checkDomainNames iterates over the domain names in an NDP DNS Search List +// option and returns any error it encounters. +func (o NDPDNSSearchList) checkDomainNames() error { + return o.iterDomainNames(nil) +} + +// iterDomainNames iterates over the domain names in an NDP DNS Search List +// option and calls a function with each valid domain name. +func (o NDPDNSSearchList) iterDomainNames(fn func(string)) error { + if l := len(o); l < minNDPDNSSearchListBodySize { + return fmt.Errorf("got %d bytes for NDP DNS Search List option's body, expected at least %d bytes: %w", l, minNDPDNSSearchListBodySize, io.ErrUnexpectedEOF) + } + + var searchList bytes.Reader + searchList.Reset(o[ndpDNSSearchListDomainNamesOffset:]) + + var scratch [maxDomainNameLength]byte + domainName := bytes.NewBuffer(scratch[:]) + + // Parse the domain names, as per RFC 1035 section 3.1. + for searchList.Len() != 0 { + domainName.Reset() + + // Parse a label within a domain name, as per RFC 1035 section 3.1. + for { + // The first byte is the label length. + labelLenByte, err := searchList.ReadByte() + if err != nil { + if err != io.EOF { + // ReadByte should only ever return nil or io.EOF. + panic(fmt.Sprintf("unexpected error when reading a label's length: %s", err)) + } + + // We use io.ErrUnexpectedEOF as exhausting the buffer is unexpected + // once we start parsing a domain name; we expect the buffer to contain + // enough bytes for the whole domain name. + return fmt.Errorf("unexpected exhausted buffer while parsing a new label for a domain from NDP Search List option: %w", io.ErrUnexpectedEOF) + } + labelLen := int(labelLenByte) + + // A zero-length label implies the end of a domain name. + if labelLen == 0 { + // If the domain name is empty or we have no callback function, do + // nothing further with the current domain name. + if domainName.Len() == 0 || fn == nil { + break + } + + // Ignore the trailing period in the parsed domain name. + domainName.Truncate(domainName.Len() - 1) + fn(domainName.String()) + break + } + + // The label's length must not exceed the maximum length for a label. + if labelLen > maxDomainNameLabelLength { + return fmt.Errorf("label length of %d bytes is greater than the max label length of %d bytes for an NDP Search List option: %w", labelLen, maxDomainNameLabelLength, ErrNDPOptMalformedBody) + } + + // The label (and trailing period) must not make the domain name too long. + if labelLen+1 > domainName.Cap()-domainName.Len() { + return fmt.Errorf("label would make an NDP Search List option's domain name longer than the max domain name length of %d bytes: %w", maxDomainNameLength, ErrNDPOptMalformedBody) + } + + // Copy the label and add a trailing period. + for i := 0; i < labelLen; i++ { + b, err := searchList.ReadByte() + if err != nil { + if err != io.EOF { + panic(fmt.Sprintf("unexpected error when reading domain name's label: %s", err)) + } + + return fmt.Errorf("read %d out of %d bytes for a domain name's label from NDP Search List option: %w", i, labelLen, io.ErrUnexpectedEOF) + } + + // As per RFC 1035 section 2.3.1: + // 1) the label must only contain ASCII include letters, digits and + // hyphens + // 2) the first character in a label must be a letter + // 3) the last letter in a label must be a letter or digit + + if !isLetter(b) { + if i == 0 { + return fmt.Errorf("first character of a domain name's label in an NDP Search List option must be a letter, got character code = %d: %w", b, ErrNDPOptMalformedBody) + } + + if b == '-' { + if i == labelLen-1 { + return fmt.Errorf("last character of a domain name's label in an NDP Search List option must not be a hyphen (-): %w", ErrNDPOptMalformedBody) + } + } else if !isDigit(b) { + return fmt.Errorf("domain name's label in an NDP Search List option may only contain letters, digits and hyphens, got character code = %d: %w", b, ErrNDPOptMalformedBody) + } + } + + // If b is an upper case character, make it lower case. + if isUpperLetter(b) { + b = b - 'A' + 'a' + } + + if err := domainName.WriteByte(b); err != nil { + panic(fmt.Sprintf("unexpected error writing label to domain name buffer: %s", err)) + } + } + if err := domainName.WriteByte('.'); err != nil { + panic(fmt.Sprintf("unexpected error writing trailing period to domain name buffer: %s", err)) + } + } + } + + return nil +} + +func isLetter(b byte) bool { + return b >= 'a' && b <= 'z' || isUpperLetter(b) +} + +func isUpperLetter(b byte) bool { + return b >= 'A' && b <= 'Z' +} + +func isDigit(b byte) bool { + return b >= '0' && b <= '9' +} diff --git a/pkg/tcpip/header/ndp_test.go b/pkg/tcpip/header/ndp_test.go index 2341329c4..dc4591253 100644 --- a/pkg/tcpip/header/ndp_test.go +++ b/pkg/tcpip/header/ndp_test.go @@ -17,7 +17,9 @@ package header import ( "bytes" "errors" + "fmt" "io" + "regexp" "testing" "time" @@ -667,6 +669,477 @@ func TestNDPRecursiveDNSServerOption(t *testing.T) { } } +// TestNDPDNSSearchListOption tests the getters of NDPDNSSearchList. +func TestNDPDNSSearchListOption(t *testing.T) { + tests := []struct { + name string + buf []byte + lifetime time.Duration + domainNames []string + err error + }{ + { + name: "Valid1Label", + buf: []byte{ + 0, 0, + 0, 0, 0, 1, + 3, 'a', 'b', 'c', + 0, + 0, 0, 0, + }, + lifetime: time.Second, + domainNames: []string{ + "abc", + }, + err: nil, + }, + { + name: "Valid2Label", + buf: []byte{ + 0, 0, + 0, 0, 0, 5, + 3, 'a', 'b', 'c', + 4, 'a', 'b', 'c', 'd', + 0, + 0, 0, 0, 0, 0, 0, + }, + lifetime: 5 * time.Second, + domainNames: []string{ + "abc.abcd", + }, + err: nil, + }, + { + name: "Valid3Label", + buf: []byte{ + 0, 0, + 1, 0, 0, 0, + 3, 'a', 'b', 'c', + 4, 'a', 'b', 'c', 'd', + 1, 'e', + 0, + 0, 0, 0, 0, + }, + lifetime: 16777216 * time.Second, + domainNames: []string{ + "abc.abcd.e", + }, + err: nil, + }, + { + name: "Valid2Domains", + buf: []byte{ + 0, 0, + 1, 2, 3, 4, + 3, 'a', 'b', 'c', + 0, + 2, 'd', 'e', + 3, 'x', 'y', 'z', + 0, + 0, 0, 0, + }, + lifetime: 16909060 * time.Second, + domainNames: []string{ + "abc", + "de.xyz", + }, + err: nil, + }, + { + name: "Valid3DomainsMixedCase", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 3, 'a', 'B', 'c', + 0, + 2, 'd', 'E', + 3, 'X', 'y', 'z', + 0, + 1, 'J', + 0, + }, + lifetime: 0, + domainNames: []string{ + "abc", + "de.xyz", + "j", + }, + err: nil, + }, + { + name: "ValidDomainAfterNULL", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 3, 'a', 'B', 'c', + 0, 0, 0, 0, + 2, 'd', 'E', + 3, 'X', 'y', 'z', + 0, + }, + lifetime: 0, + domainNames: []string{ + "abc", + "de.xyz", + }, + err: nil, + }, + { + name: "Valid0Domains", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 0, + 0, 0, 0, 0, 0, 0, 0, + }, + lifetime: 0, + domainNames: nil, + err: nil, + }, + { + name: "NoTrailingNull", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 7, 'a', 'b', 'c', 'd', 'e', 'f', 'g', + }, + lifetime: 0, + domainNames: nil, + err: io.ErrUnexpectedEOF, + }, + { + name: "IncorrectLength", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 8, 'a', 'b', 'c', 'd', 'e', 'f', 'g', + }, + lifetime: 0, + domainNames: nil, + err: io.ErrUnexpectedEOF, + }, + { + name: "IncorrectLengthWithNULL", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 7, 'a', 'b', 'c', 'd', 'e', 'f', + 0, + }, + lifetime: 0, + domainNames: nil, + err: ErrNDPOptMalformedBody, + }, + { + name: "LabelOfLength63", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 0, + }, + lifetime: 0, + domainNames: []string{ + "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijk", + }, + err: nil, + }, + { + name: "LabelOfLength64", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 64, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', + 0, + }, + lifetime: 0, + domainNames: nil, + err: ErrNDPOptMalformedBody, + }, + { + name: "DomainNameOfLength255", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 62, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', + 0, + }, + lifetime: 0, + domainNames: []string{ + "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijk.abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijk.abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijk.abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghij", + }, + err: nil, + }, + { + name: "DomainNameOfLength256", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 0, + }, + lifetime: 0, + domainNames: nil, + err: ErrNDPOptMalformedBody, + }, + { + name: "StartingDigitForLabel", + buf: []byte{ + 0, 0, + 0, 0, 0, 1, + 3, '9', 'b', 'c', + 0, + 0, 0, 0, + }, + lifetime: time.Second, + domainNames: nil, + err: ErrNDPOptMalformedBody, + }, + { + name: "StartingHyphenForLabel", + buf: []byte{ + 0, 0, + 0, 0, 0, 1, + 3, '-', 'b', 'c', + 0, + 0, 0, 0, + }, + lifetime: time.Second, + domainNames: nil, + err: ErrNDPOptMalformedBody, + }, + { + name: "EndingHyphenForLabel", + buf: []byte{ + 0, 0, + 0, 0, 0, 1, + 3, 'a', 'b', '-', + 0, + 0, 0, 0, + }, + lifetime: time.Second, + domainNames: nil, + err: ErrNDPOptMalformedBody, + }, + { + name: "EndingDigitForLabel", + buf: []byte{ + 0, 0, + 0, 0, 0, 1, + 3, 'a', 'b', '9', + 0, + 0, 0, 0, + }, + lifetime: time.Second, + domainNames: []string{ + "ab9", + }, + err: nil, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + opt := NDPDNSSearchList(test.buf) + + if got := opt.Lifetime(); got != test.lifetime { + t.Errorf("got Lifetime = %d, want = %d", got, test.lifetime) + } + domainNames, err := opt.DomainNames() + if !errors.Is(err, test.err) { + t.Errorf("opt.DomainNames() = %s", err) + } + if diff := cmp.Diff(domainNames, test.domainNames); diff != "" { + t.Errorf("mismatched domain names (-want +got):\n%s", diff) + } + }) + } +} + +func TestNDPSearchListOptionDomainNameLabelInvalidSymbols(t *testing.T) { + for r := rune(0); r <= 255; r++ { + t.Run(fmt.Sprintf("RuneVal=%d", r), func(t *testing.T) { + buf := []byte{ + 0, 0, + 0, 0, 0, 0, + 3, 'a', 0 /* will be replaced */, 'c', + 0, + 0, 0, 0, + } + buf[8] = uint8(r) + opt := NDPDNSSearchList(buf) + + // As per RFC 1035 section 2.3.1, the label must only include ASCII + // letters, digits and hyphens (a-z, A-Z, 0-9, -). + var expectedErr error + re := regexp.MustCompile(`[a-zA-Z0-9-]`) + if !re.Match([]byte{byte(r)}) { + expectedErr = ErrNDPOptMalformedBody + } + + if domainNames, err := opt.DomainNames(); !errors.Is(err, expectedErr) { + t.Errorf("got opt.DomainNames() = (%s, %v), want = (_, %v)", domainNames, err, ErrNDPOptMalformedBody) + } + }) + } +} + +func TestNDPDNSSearchListOptionSerialize(t *testing.T) { + b := []byte{ + 9, 8, + 1, 0, 0, 0, + 3, 'a', 'b', 'c', + 4, 'a', 'b', 'c', 'd', + 1, 'e', + 0, + } + targetBuf := []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1} + expected := []byte{ + 31, 3, 0, 0, + 1, 0, 0, 0, + 3, 'a', 'b', 'c', + 4, 'a', 'b', 'c', 'd', + 1, 'e', + 0, + 0, 0, 0, 0, + } + opts := NDPOptions(targetBuf) + serializer := NDPOptionsSerializer{ + NDPDNSSearchList(b), + } + if got, want := opts.Serialize(serializer), len(expected); got != want { + t.Errorf("got Serialize = %d, want = %d", got, want) + } + if !bytes.Equal(targetBuf, expected) { + t.Fatalf("got targetBuf = %x, want = %x", targetBuf, expected) + } + + it, err := opts.Iter(true) + if err != nil { + t.Fatalf("got Iter = (_, %s), want = (_, nil)", err) + } + + next, done, err := it.Next() + if err != nil { + t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if done { + t.Fatal("got Next = (_, true, _), want = (_, false, _)") + } + if got := next.Type(); got != NDPDNSSearchListOptionType { + t.Errorf("got Type = %d, want = %d", got, NDPDNSSearchListOptionType) + } + + opt, ok := next.(NDPDNSSearchList) + if !ok { + t.Fatalf("next (type = %T) cannot be casted to an NDPDNSSearchList", next) + } + if got := opt.Type(); got != 31 { + t.Errorf("got Type = %d, want = 31", got) + } + if got := opt.Length(); got != 22 { + t.Errorf("got Length = %d, want = 22", got) + } + if got, want := opt.Lifetime(), 16777216*time.Second; got != want { + t.Errorf("got Lifetime = %s, want = %s", got, want) + } + domainNames, err := opt.DomainNames() + if err != nil { + t.Errorf("opt.DomainNames() = %s", err) + } + if diff := cmp.Diff(domainNames, []string{"abc.abcd.e"}); diff != "" { + t.Errorf("domain names mismatch (-want +got):\n%s", diff) + } + + // Iterator should not return anything else. + next, done, err = it.Next() + if err != nil { + t.Errorf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if !done { + t.Error("got Next = (_, false, _), want = (_, true, _)") + } + if next != nil { + t.Errorf("got Next = (%x, _, _), want = (nil, _, _)", next) + } +} + // TestNDPOptionsIterCheck tests that Iter will return false if the NDPOptions // the iterator was returned for is malformed. func TestNDPOptionsIterCheck(t *testing.T) { @@ -832,6 +1305,107 @@ func TestNDPOptionsIterCheck(t *testing.T) { }, expectedErr: ErrNDPOptMalformedBody, }, + { + name: "DNSSearchListLargeCompliantRFC1035", + buf: []byte{ + 31, 33, 0, 0, + 0, 0, 0, 0, + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 62, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', + 0, + }, + expectedErr: nil, + }, + { + name: "DNSSearchListNonCompliantRFC1035", + buf: []byte{ + 31, 33, 0, 0, + 0, 0, 0, 0, + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 0, + 0, 0, 0, 0, 0, 0, 0, 0, + }, + expectedErr: ErrNDPOptMalformedBody, + }, + { + name: "DNSSearchListValidSmall", + buf: []byte{ + 31, 2, 0, 0, + 0, 0, 0, 0, + 6, 'a', 'b', 'c', 'd', 'e', 'f', + 0, + }, + expectedErr: nil, + }, + { + name: "DNSSearchListTooSmall", + buf: []byte{ + 31, 1, 0, 0, + 0, 0, 0, + }, + expectedErr: io.ErrUnexpectedEOF, + }, } for _, test := range tests { diff --git a/pkg/tcpip/stack/ndp.go b/pkg/tcpip/stack/ndp.go index 8140c6dd4..193a9dfde 100644 --- a/pkg/tcpip/stack/ndp.go +++ b/pkg/tcpip/stack/ndp.go @@ -241,6 +241,16 @@ type NDPDispatcher interface { // call functions on the stack itself. OnRecursiveDNSServerOption(nicID tcpip.NICID, addrs []tcpip.Address, lifetime time.Duration) + // OnDNSSearchListOption will be called when an NDP option with a DNS + // search list has been received. + // + // It is up to the caller to use the domain names in the search list + // for only their valid lifetime. OnDNSSearchListOption may be called + // with new or already known domain names. If called with known domain + // names, their valid lifetimes must be refreshed to lifetime (it may + // be increased, decreased or completely invalidated when lifetime = 0. + OnDNSSearchListOption(nicID tcpip.NICID, domainNames []string, lifetime time.Duration) + // OnDHCPv6Configuration will be called with an updated configuration that is // available via DHCPv6 for a specified NIC. // @@ -714,6 +724,14 @@ func (ndp *ndpState) handleRA(ip tcpip.Address, ra header.NDPRouterAdvert) { addrs, _ := opt.Addresses() ndp.nic.stack.ndpDisp.OnRecursiveDNSServerOption(ndp.nic.ID(), addrs, opt.Lifetime()) + case header.NDPDNSSearchList: + if ndp.nic.stack.ndpDisp == nil { + continue + } + + domainNames, _ := opt.DomainNames() + ndp.nic.stack.ndpDisp.OnDNSSearchListOption(ndp.nic.ID(), domainNames, opt.Lifetime()) + case header.NDPPrefixInformation: prefix := opt.Subnet() diff --git a/pkg/tcpip/stack/ndp_test.go b/pkg/tcpip/stack/ndp_test.go index 6562a2d22..6dd460984 100644 --- a/pkg/tcpip/stack/ndp_test.go +++ b/pkg/tcpip/stack/ndp_test.go @@ -133,6 +133,12 @@ type ndpRDNSSEvent struct { rdnss ndpRDNSS } +type ndpDNSSLEvent struct { + nicID tcpip.NICID + domainNames []string + lifetime time.Duration +} + type ndpDHCPv6Event struct { nicID tcpip.NICID configuration stack.DHCPv6ConfigurationFromNDPRA @@ -150,6 +156,8 @@ type ndpDispatcher struct { rememberPrefix bool autoGenAddrC chan ndpAutoGenAddrEvent rdnssC chan ndpRDNSSEvent + dnsslC chan ndpDNSSLEvent + routeTable []tcpip.Route dhcpv6ConfigurationC chan ndpDHCPv6Event } @@ -257,6 +265,17 @@ func (n *ndpDispatcher) OnRecursiveDNSServerOption(nicID tcpip.NICID, addrs []tc } } +// Implements stack.NDPDispatcher.OnDNSSearchListOption. +func (n *ndpDispatcher) OnDNSSearchListOption(nicID tcpip.NICID, domainNames []string, lifetime time.Duration) { + if n.dnsslC != nil { + n.dnsslC <- ndpDNSSLEvent{ + nicID, + domainNames, + lifetime, + } + } +} + // Implements stack.NDPDispatcher.OnDHCPv6Configuration. func (n *ndpDispatcher) OnDHCPv6Configuration(nicID tcpip.NICID, configuration stack.DHCPv6ConfigurationFromNDPRA) { if c := n.dhcpv6ConfigurationC; c != nil { @@ -3386,6 +3405,112 @@ func TestNDPRecursiveDNSServerDispatch(t *testing.T) { } } +// TestNDPDNSSearchListDispatch tests that the integrator is informed when an +// NDP DNS Search List option is received with at least one domain name in the +// search list. +func TestNDPDNSSearchListDispatch(t *testing.T) { + const nicID = 1 + + ndpDisp := ndpDispatcher{ + dnsslC: make(chan ndpDNSSLEvent, 3), + } + e := channel.New(0, 1280, linkAddr1) + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NDPConfigs: stack.NDPConfigurations{ + HandleRAs: true, + }, + NDPDisp: &ndpDisp, + }) + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID, err) + } + + optSer := header.NDPOptionsSerializer{ + header.NDPDNSSearchList([]byte{ + 0, 0, + 0, 0, 0, 0, + 2, 'h', 'i', + 0, + }), + header.NDPDNSSearchList([]byte{ + 0, 0, + 0, 0, 0, 1, + 1, 'i', + 0, + 2, 'a', 'm', + 2, 'm', 'e', + 0, + }), + header.NDPDNSSearchList([]byte{ + 0, 0, + 0, 0, 1, 0, + 3, 'x', 'y', 'z', + 0, + 5, 'h', 'e', 'l', 'l', 'o', + 5, 'w', 'o', 'r', 'l', 'd', + 0, + 4, 't', 'h', 'i', 's', + 2, 'i', 's', + 1, 'a', + 4, 't', 'e', 's', 't', + 0, + }), + } + expected := []struct { + domainNames []string + lifetime time.Duration + }{ + { + domainNames: []string{ + "hi", + }, + lifetime: 0, + }, + { + domainNames: []string{ + "i", + "am.me", + }, + lifetime: time.Second, + }, + { + domainNames: []string{ + "xyz", + "hello.world", + "this.is.a.test", + }, + lifetime: 256 * time.Second, + }, + } + + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithOpts(llAddr1, 0, optSer)) + + for i, expected := range expected { + select { + case dnssl := <-ndpDisp.dnsslC: + if dnssl.nicID != nicID { + t.Errorf("got %d-th dnssl nicID = %d, want = %d", i, dnssl.nicID, nicID) + } + if diff := cmp.Diff(dnssl.domainNames, expected.domainNames); diff != "" { + t.Errorf("%d-th dnssl domain names mismatch (-want +got):\n%s", i, diff) + } + if dnssl.lifetime != expected.lifetime { + t.Errorf("got %d-th dnssl lifetime = %s, want = %s", i, dnssl.lifetime, expected.lifetime) + } + default: + t.Fatal("expected a DNSSL event") + } + } + + // Should have no more DNSSL options. + select { + case <-ndpDisp.dnsslC: + t.Fatal("unexpectedly got a DNSSL event") + default: + } +} + // TestCleanupNDPState tests that all discovered routers and prefixes, and // auto-generated addresses are invalidated when a NIC becomes a router. func TestCleanupNDPState(t *testing.T) { |