dns

DNS client and server implementation in pure OCaml
Library dns
Module Dns . Packet
type digest_alg =
| SHA1
| SHA256
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 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.

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