Module `Dns.Packet`

DNS packet manipulation using the Cstruct library. Something of a catch-all for the time being.

author Richard Mortier <mort\@cantab.net>

author Anil Madhavapeddy anil\@recoil.org>

author Haris Rotsos

type digest_alg =

| SHA1
| SHA256

val compare_digest_alg : digest_alg -> digest_alg -> int

val digest_alg_to_string : digest_alg -> string

val string_to_digest_alg : string -> digest_alg option

val digest_alg_to_int : digest_alg -> int

val int_to_digest_alg : int -> digest_alg option

type gateway_tc

type pubkey_alg

type ipseckey_alg

type gateway

type hash_alg

type fp_type

Represent a DNSSEC algorithm, with the usual conversion functions.

type dnssec_alg =

| RSAMD5
| DH
| DSA
| ECC
| RSASHA1
| RSANSEC3
| RSASHA256
| RSASHA512
| INDIRECT
| PRIVATEDNS
| PRIVATEOID

val compare_dnssec_alg : dnssec_alg -> dnssec_alg -> int

val dnssec_alg_to_string : dnssec_alg -> string

val string_to_dnssec_alg : string -> dnssec_alg option

val int_to_dnssec_alg : int -> dnssec_alg option

val dnssec_alg_to_int : dnssec_alg -> int

type q_type =

| Q_A
| Q_NS
| Q_MD
| Q_MF
| Q_CNAME
| Q_SOA
| Q_MB
| Q_MG
| Q_MR
| Q_NULL
| Q_WKS
| Q_PTR
| Q_HINFO
| Q_MINFO
| Q_MX
| Q_TXT
| Q_RP
| Q_AFSDB
| Q_X25
| Q_ISDN
| Q_RT
| Q_NSAP
| Q_NSAPPTR
| Q_SIG
| Q_KEY
| Q_PX
| Q_GPOS
| Q_AAAA
| Q_LOC
| Q_NXT
| Q_EID
| Q_NIMLOC
| Q_SRV
| Q_ATMA
| Q_NAPTR
| Q_KM
| Q_CERT
| Q_A6
| Q_DNAME
| Q_SINK
| Q_OPT
| Q_APL
| Q_DS
| Q_SSHFP
| Q_IPSECKEY
| Q_RRSIG
| Q_NSEC
| Q_DNSKEY
| Q_NSEC3
| Q_NSEC3PARAM
| Q_SPF
| Q_UINFO
| Q_UID
| Q_GID
| Q_UNSPEC
| Q_AXFR
| Q_MAILB
| Q_MAILA
| Q_ANY_TYP
| Q_TA
| Q_DLV
| Q_UNKNOWN of int

Represent the rr type, with the usual conversion functions.

val q_type_to_int : q_type -> int

type rr_type =

| RR_UNUSED
| RR_A
| RR_NS
| RR_MD
| RR_MF
| RR_CNAME
| RR_SOA
| RR_MB
| RR_MG
| RR_MR
| RR_NULL
| RR_WKS
| RR_PTR
| RR_HINFO
| RR_MINFO
| RR_MX
| RR_TXT
| RR_RP
| RR_AFSDB
| RR_X25
| RR_ISDN
| RR_RT
| RR_NSAP
| RR_NSAPPTR
| RR_SIG
| RR_KEY
| RR_PX
| RR_GPOS
| RR_AAAA
| RR_LOC
| RR_NXT
| RR_EID
| RR_NIMLOC
| RR_SRV
| RR_ATMA
| RR_NAPTR
| RR_KM
| RR_CERT
| RR_A6
| RR_DNAME
| RR_SINK
| RR_OPT
| RR_APL
| RR_DS
| RR_SSHFP
| RR_IPSECKEY
| RR_RRSIG
| RR_NSEC
| RR_DNSKEY
| RR_NSEC3
| RR_NSEC3PARAM
| RR_SPF
| RR_UINFO
| RR_UID
| RR_GID
| RR_UNSPEC

val string_to_rr_type : string -> rr_type option

val rr_type_to_string : rr_type -> string

val int_to_rr_type : int -> rr_type option

val rr_type_to_int : rr_type -> int

type type_bit_map

type type_bit_maps

Represent RDATA elements; a variant type to avoid collision with the compact Trie representation from RR.

type rdata =

| A of Ipaddr.V4.t
| AAAA of Ipaddr.V6.t
| AFSDB of Cstruct.uint16 * Name.t
| CNAME of Name.t
| DNSKEY of Cstruct.uint16 * dnssec_alg * string
| DS of Cstruct.uint16 * dnssec_alg * digest_alg * string
| HINFO of string * string
| IPSECKEY of Cstruct.byte * gateway_tc * ipseckey_alg * gateway * string
| ISDN of string * string option
| MB of Name.t
| MD of Name.t
| MF of Name.t
| MG of Name.t
| MINFO of Name.t * Name.t
| MR of Name.t
| MX of Cstruct.uint16 * Name.t
| NS of Name.t
| NSEC of Name.t * type_bit_maps
| NSEC3 of hash_alg * Cstruct.byte * Cstruct.uint16 * Cstruct.byte * string * Cstruct.byte * string * type_bit_maps
| NSEC3PARAM of hash_alg * Cstruct.byte * Cstruct.uint16 * Cstruct.byte * string
| PTR of Name.t
| RP of Name.t * Name.t
| RRSIG of rr_type * dnssec_alg * Cstruct.byte * int32 * int32 * int32 * Cstruct.uint16 * Name.t * string
| SIG of dnssec_alg * int32 * int32 * Cstruct.uint16 * Name.t * string
| RT of Cstruct.uint16 * Name.t
| SOA of Name.t * Name.t * int32 * int32 * int32 * int32 * int32
| SRV of Cstruct.uint16 * Cstruct.uint16 * Cstruct.uint16 * Name.t
| SSHFP of pubkey_alg * fp_type * string
| TXT of string list
| UNKNOWN of int * string
| WKS of Ipaddr.V4.t * Cstruct.byte * string
| X25 of string
| EDNS0 of int * int * bool * (int * string) list

val hex_of_string : string -> string

val rdata_to_string : rdata -> string

val rdata_to_rr_type : rdata -> rr_type

val marshal_rdata : 
  int Name.Map.t ->
  ?compress:bool ->
  int ->
  Cstruct.t ->
  rdata ->
  rr_type * int Name.Map.t * int

Marshal the RR data into the DNS binary format. Raises Not_implemented if the RR type is known but the logic is not implemented in the library yet.

val compare_rdata : rdata -> rdata -> int

exception Not_implemented

val parse_rdata : 
  (int, Name.label) Hashtbl.t ->
  int ->
  rr_type ->
  int ->
  int32 ->
  Cstruct.t ->
  rdata

Parse an RDATA element from a packet, given the set of already encountered names, a starting index, and the type of the RDATA. Raises Not_implemented if the RR type is not recognized.

type rr_class =

| RR_IN
| RR_CS
| RR_CH
| RR_HS
| RR_ANY

The class of a rr, and usual conversion functions.

val rr_class_to_string : rr_class -> string

type rr = {

name : Name.t;
cls : rr_class;
flush : bool;
ttl : int32;
rdata : rdata;

}

A resource record, with usual conversion and parsing functions.

val rr_to_string : rr -> string

val marshal_rr : 
  ?compress:bool ->
  (int Name.Map.t * int * Cstruct.t) ->
  rr ->
  int Name.Map.t * int * Cstruct.t

val parse_rr : 
  (int, Name.label) Hashtbl.t ->
  int ->
  Cstruct.t ->
  rr * (int * Cstruct.t)

val q_type_matches_rr_type : q_type -> rr_type -> bool

A predicate to test if a q_type applies to an rr_type.

val q_type_to_string : q_type -> string

A question type, with the usual conversion functions.

val string_to_q_type : string -> q_type option

type q_class =

| Q_IN
| Q_CS
| Q_CH
| Q_HS
| Q_NONE
| Q_ANY_CLS

A question class, with the usual conversion functions.

val q_class_to_string : q_class -> string

val string_to_q_class : string -> q_class option

type q_unicast =

| Q_Normal
| Q_mDNS_Unicast

For normal DNS, only Q_Normal is valid. For mDNS, Q_Normal (called QM in RFC 6762) requests a multicast response or Q_mDNS_Unicast (called QU in RFC 6762) requests a unicast response.

see https://tools.ietf.org/html/rfc6762#section-5.4
RFC 6762 Section 5.4

val q_unicast_to_string : q_unicast -> string

type question = {

q_name : Name.t;
q_type : q_type;
q_class : q_class;
q_unicast : q_unicast;

}

A question, with the usual conversion functions. Use make_question if you want to take advantage of default values.

A convenience function to create a question record with default values for q_class (Q_IN) and q_unicast (Q_Normal).

val make_question : 
  ?q_class:q_class ->
  ?q_unicast:q_unicast ->
  q_type ->
  Name.t ->
  question

A convenience function to create a question record with default values for q_class (Q_IN) and q_unicast (Q_Normal).

val question_to_string : question -> string

val parse_question : 
  (int, Name.label) Hashtbl.t ->
  int ->
  Cstruct.t ->
  question * (int * Cstruct.t)

type qr =

| Query
| Response

The qr field from the DNS header detail.

type opcode =

| Standard
| Inverse
| Status
| Notify
| Update
| Reserved of int

A DNS opcode, with the usual conversion functions.

val opcode_to_string : opcode -> string

type rcode =

| NoError
| FormErr
| ServFail
| NXDomain
| NotImp
| Refused
| YXDomain
| YXRRSet
| NXRRSet
| NotAuth
| NotZone
| BadVers
| BadKey
| BadTime
| BadMode
| BadName
| BadAlg

A DNS response code, with the usual conversion functions.

val rcode_to_string : rcode -> string

type detail = {

qr : qr;
opcode : opcode;
aa : bool;
tc : bool;
rd : bool;
ra : bool;
rcode : rcode;

}

The detail field from the DNS header, with the usual conversion functions.

type t = {

id : int;
detail : detail;
questions : question list;
answers : rr list;
authorities : rr list;
additionals : rr list;

}

And finally, the DNS packet itself, with conversion functions.

val to_string : t -> string

val parse : Cstruct.t -> t

val marshal : ?alloc:(unit -> Cstruct.t) -> t -> Cstruct.t

The marshalling entry point, given a Dns structure.

returns
the marshalled packet

package dns

Module Dns.Packet

Module `Dns.Packet`