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mirror of https://github.com/wader/fq.git synced 2024-11-28 03:02:55 +03:00
fq/format/dns/dns.go
Mattias Wadman 1ddea1ada3 interp,format: Refactor registry usage and use function helpers
Move registry to interp and add support for functions and filesystems.
This will be used later for allow formats to add own functions and fq code.

Add gojqextra function helpers to have more comfortable API to add functions.
Takes care of argument type casting and JQValue:s and some more things.

Refactor interp package to use new function helper and registry. Probably
fixes a bunch of JQValue bugs and other type errors.

Refactor out some mpeg nal things to mpeg format.

Refactor interp jq code into display.q and init.jq.

Remove undocumented aes_ctr funciton, was a test. Hopefully will add more crypto things laster.
2022-07-16 19:24:13 +02:00

277 lines
8.0 KiB
Go

package dns
// https://datatracker.ietf.org/doc/html/rfc1035
// https://github.com/Forescout/namewreck/blob/main/rfc/draft-dashevskyi-dnsrr-antipatterns-00.txt
import (
"net"
"strings"
"github.com/wader/fq/format"
"github.com/wader/fq/pkg/decode"
"github.com/wader/fq/pkg/interp"
"github.com/wader/fq/pkg/scalar"
)
func init() {
interp.RegisterFormat(decode.Format{
Name: format.DNS,
Description: "DNS packet",
Groups: []string{
format.TCP_STREAM,
format.UDP_PAYLOAD,
},
DecodeFn: dnsUDPDecode,
})
}
const (
classIN = 1
)
var classNames = scalar.URangeToScalar{
{Range: [2]uint64{0x0000, 0x0000}, S: scalar.S{Sym: "reserved", Description: "Reserved"}},
{Range: [2]uint64{classIN, classIN}, S: scalar.S{Sym: "in", Description: "Internet"}},
{Range: [2]uint64{0x0002, 0x0002}, S: scalar.S{Sym: "unassigned", Description: "Unassigned"}},
{Range: [2]uint64{0x0003, 0x0003}, S: scalar.S{Sym: "chaos", Description: "Chaos"}},
{Range: [2]uint64{0x0004, 0x0004}, S: scalar.S{Sym: "hesiod", Description: "Hesiod"}},
{Range: [2]uint64{0x0005, 0x00fd}, S: scalar.S{Sym: "unassigned", Description: "Unassigned"}},
{Range: [2]uint64{0x00fe, 0x00fe}, S: scalar.S{Sym: "qclass_none", Description: "QCLASS NONE"}},
{Range: [2]uint64{0x00ff, 0x00ff}, S: scalar.S{Sym: "qclass_any", Description: "QCLASS ANY"}},
{Range: [2]uint64{0x0100, 0xfeff}, S: scalar.S{Sym: "unassigned", Description: "Unassigned"}},
{Range: [2]uint64{0xff00, 0xfffe}, S: scalar.S{Sym: "private", Description: "Reserved for Private Use"}},
{Range: [2]uint64{0xffff, 0xffff}, S: scalar.S{Sym: "reserved", Description: "Reserved"}},
}
const (
typeA = 1
typeNS = 2
typeCNAME = 5
typeSOA = 6
typePTR = 12
typeTXT = 16
typeAAAA = 28
)
var typeNames = scalar.UToSymStr{
typeA: "a",
typeAAAA: "aaaa",
18: "afsdb",
42: "apl",
257: "caa",
60: "cdnskey",
59: "cds",
37: "cert",
typeCNAME: "cname",
62: "csync",
49: "dhcid",
32769: "dlv",
39: "dname",
48: "dnskey",
43: "ds",
108: "eui48",
109: "eui64",
13: "hinfo",
55: "hip",
45: "ipseckey",
25: "key",
36: "kx",
29: "loc",
15: "mx",
35: "naptr",
typeNS: "ns",
47: "nsec",
50: "nsec3",
51: "nsec3_param",
61: "openpgp_key",
typePTR: "ptr",
46: "rrsig",
17: "rp",
24: "sig",
53: "smimea",
typeSOA: "soa",
33: "srv",
44: "sshfp",
32768: "ta",
249: "tkey",
52: "tlsa",
250: "tsig",
typeTXT: "txt",
256: "uri",
63: "zonemd",
64: "svcb",
65: "https",
}
var rcodeNames = scalar.UToScalar{
0: {Sym: "no_error", Description: "No error"},
1: {Sym: "form_err", Description: "Format error"},
2: {Sym: "serv_fail", Description: "Server failure"},
3: {Sym: "nx_domain", Description: "Non-Existent Domain"},
4: {Sym: "no_tiimpl", Description: "Not implemented"},
5: {Sym: "refused", Description: "Refused"},
6: {Sym: "yx_domain", Description: "DescriptionName Exists when it should not"}, // RFC 2136
7: {Sym: "yxrr_set", Description: "RR Set Exists when it should not"}, // RFC 2136
8: {Sym: "nxrr_set", Description: "RR Set that should exist does not"}, // RFC 2136
9: {Sym: "not_auth", Description: "Server Not Authoritative for zone"}, // RFC 2136
10: {Sym: "not_zone", Description: "Name not contained in zone"}, // RFC 2136
// collision in RFCs
// 16: {Sym: "badvers", Description: "Bad OPT Version"}, // RFC 2671
16: {Sym: "bad_sig", Description: "TSIG Signature Failure"}, // RFC 2845
17: {Sym: "bad_key", Description: "Key not recognized"}, // RFC 2845
18: {Sym: "bad_time", Description: "Signature out of time window"}, // RFC 2845
19: {Sym: "bad_mode", Description: "Bad TKEY Mode"}, // RFC 2930
20: {Sym: "bad_name", Description: "Duplicate key name"}, // RFC 2930
21: {Sym: "bad_alg", Description: "Algorithm not supported"}, // RFC 2930
}
func decodeAStr(d *decode.D) string {
return net.IP(d.BytesLen(4)).String()
}
func decodeAAAAStr(d *decode.D) string {
return net.IP(d.BytesLen(16)).String()
}
func fieldDecodeLabel(d *decode.D, pointerOffset int64, name string) {
var endPos int64
const maxJumps = 100
jumpCount := 0
d.FieldStruct(name, func(d *decode.D) {
var ls []string
d.FieldArray("labels", func(d *decode.D) {
d.RangeSorted = false
seenTermintor := false
for !seenTermintor {
d.FieldStruct("label", func(d *decode.D) {
if d.PeekBits(2) == 0b11 {
d.FieldU2("is_pointer")
pointer := d.FieldU14("pointer")
if endPos == 0 {
endPos = d.Pos()
}
jumpCount++
if jumpCount > maxJumps {
d.Fatalf("label has more than %d jumps", maxJumps)
}
d.SeekAbs(int64(pointer)*8 + pointerOffset)
}
l := d.FieldU8("length")
if l == 0 {
seenTermintor = true
return
}
ls = append(ls, d.FieldUTF8("value", int(l)))
})
}
})
d.FieldValueStr("value", strings.Join(ls, "."))
})
if endPos != 0 {
d.SeekAbs(endPos)
}
}
func dnsDecodeRR(d *decode.D, pointerOffset int64, resp bool, count uint64, name string, structName string) {
d.FieldArray(name, func(d *decode.D) {
d.RangeSorted = false
for i := uint64(0); i < count; i++ {
d.FieldStruct(structName, func(d *decode.D) {
fieldDecodeLabel(d, pointerOffset, "name")
typ := d.FieldU16("type", typeNames)
class := d.FieldU16("class", classNames)
if resp {
d.FieldU32("ttl")
rdLength := d.FieldU16("rdlength")
d.FramedFn(int64(rdLength)*8, func(d *decode.D) {
// TODO: all only for classIN?
switch {
case class == classIN && typ == typeA:
d.FieldStrFn("address", decodeAStr)
case typ == typeNS:
fieldDecodeLabel(d, pointerOffset, "ns")
case typ == typeCNAME:
fieldDecodeLabel(d, pointerOffset, "cname")
case typ == typeSOA:
fieldDecodeLabel(d, pointerOffset, "mname")
fieldDecodeLabel(d, pointerOffset, "rname")
d.FieldU32("serial")
d.FieldU32("refresh")
d.FieldU32("retry")
d.FieldU32("expire")
d.FieldU32("minimum")
case typ == typePTR:
fieldDecodeLabel(d, pointerOffset, "ptr")
case typ == typeTXT:
var ss []string
d.FieldStruct("txt", func(d *decode.D) {
d.FieldArray("strings", func(d *decode.D) {
for !d.End() {
ss = append(ss, d.FieldUTF8ShortString("string"))
}
})
d.FieldValueStr("value", strings.Join(ss, ""))
})
case class == classIN && typ == typeAAAA:
d.FieldStrFn("address", decodeAAAAStr)
default:
d.FieldUTF8("rdata", int(rdLength))
}
})
}
})
}
})
}
func dnsDecode(d *decode.D, isTCP bool) any {
pointerOffset := int64(0)
d.FieldStruct("header", func(d *decode.D) {
if isTCP {
pointerOffset = 16
d.FieldU16("length")
}
d.FieldU16("id")
d.FieldU1("qr", scalar.UToSymStr{
0: "query",
1: "response",
})
d.FieldU4("opcode", scalar.UToSymStr{
0: "query",
1: "iquery",
2: "status",
4: "notify", // RFC 1996
5: "update", // RFC 2136
})
d.FieldBool("authoritative_answer")
d.FieldBool("truncation")
d.FieldBool("recursion_desired")
d.FieldBool("recursion_available")
d.FieldU3("z")
d.FieldU4("rcode", rcodeNames)
})
qdCount := d.FieldU16("qd_count")
anCount := d.FieldU16("an_count")
nsCount := d.FieldU16("ns_count")
arCount := d.FieldU16("ar_count")
dnsDecodeRR(d, pointerOffset, false, qdCount, "questions", "question")
dnsDecodeRR(d, pointerOffset, true, anCount, "answers", "answer")
dnsDecodeRR(d, pointerOffset, true, nsCount, "nameservers", "nameserver")
dnsDecodeRR(d, pointerOffset, true, arCount, "additionals", "additional")
return nil
}
func dnsUDPDecode(d *decode.D, in any) any {
if upi, ok := in.(format.UDPPayloadIn); ok {
upi.MustIsPort(d.Fatalf, format.UDPPortDomain, format.UDPPortMDNS)
}
return dnsDecode(d, false)
}