Struct trust_dns::op::header::Header
[−]
[src]
pub struct Header { /* fields omitted */ }
Metadata for the Message
struct.
RFC 1035, DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION, November 1987
4.1.1. Header section format
The header contains the following fields
1 1 1 1 1 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| ID |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|QR| Opcode |AA|TC|RD|RA|ZZ|AD|CD| RCODE | /// AD and CD from RFC4035
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| QDCOUNT / ZCOUNT |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| ANCOUNT / PRCOUNT |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| NSCOUNT / UPCOUNT |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| ARCOUNT / ADCOUNT |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
where
Z Reserved for future use. Must be zero in all queries
and responses.
Methods
impl Header
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fn new() -> Self
A default Header, not very useful.
fn len() -> usize
Length of the header, always 12 bytes
fn set_id(&mut self, id: u16) -> &mut Self
Sets the id of the message, for queries this shoudl be random.
fn set_message_type(&mut self, message_type: MessageType) -> &mut Self
Sets the message type, Queries and Updates both use Query.
fn set_op_code(&mut self, op_code: OpCode) -> &mut Self
Set the operation code for the message
From the server is specifies that it is an authoritative reqponse.
fn set_truncated(&mut self, truncated: bool) -> &mut Self
Specifies that the records were too large for the payload.
See EDNS or TCP for resolutions to truncation.
fn set_recursion_desired(&mut self, recursion_desired: bool) -> &mut Self
Specify that the resolver should recursiviley request data from upstream DNS nodes
fn set_recursion_available(&mut self, recursion_available: bool) -> &mut Self
Specifies that recursion is available from this or the remote resolver
fn set_authentic_data(&mut self, authentic_data: bool) -> &mut Self
Specifies that the data is authnetic, i.e. the resolver believes all data to be valid through DNSSec
fn set_checking_disabled(&mut self, checking_disabled: bool) -> &mut Self
Used during recursive resolution to specified if a resolver should or should not validate DNSSec signatures
fn set_response_code(&mut self, response_code: ResponseCode) -> &mut Self
The low responsed code (original response codes before EDNS extensions)
fn set_query_count(&mut self, query_count: u16) -> &mut Self
Number or query records in the message
fn set_answer_count(&mut self, answer_count: u16) -> &mut Self
Number of answer records in the message
fn set_name_server_count(&mut self, name_server_count: u16) -> &mut Self
Number of name server records in the message
fn set_additional_count(&mut self, additional_count: u16) -> &mut Self
Number of additional records in the message
fn id(&self) -> u16
ID A 16 bit identifier assigned by the program that
generates any kind of query. This identifier is copied
the corresponding reply and can be used by the requester
to match up replies to outstanding queries.
fn message_type(&self) -> MessageType
QR A one bit field that specifies whether this message is a
query (0), or a response (1).
fn op_code(&self) -> OpCode
OPCODE A four bit field that specifies kind of query in this
message. This value is set by the originator of a query
and copied into the response. The values are: <see super::op_code>
AA Authoritative Answer - this bit is valid in responses,
and specifies that the responding name server is an
authority for the domain name in question section.
Note that the contents of the answer section may have
multiple owner names because of aliases. The AA bit
corresponds to the name which matches the query name, or
the first owner name in the answer section.
fn truncated(&self) -> bool
TC TrunCation - specifies that this message was truncated
due to length greater than that permitted on the
transmission channel.
fn recursion_desired(&self) -> bool
RD Recursion Desired - this bit may be set in a query and
is copied into the response. If RD is set, it directs
the name server to pursue the query recursively.
Recursive query support is optional.
fn recursion_available(&self) -> bool
RA Recursion Available - this be is set or cleared in a
response, and denotes whether recursive query support is
available in the name server.
fn authentic_data(&self) -> bool
RFC 4035, DNSSEC Resource Records, March 2005
3.1.6. The AD and CD Bits in an Authoritative Response
The CD and AD bits are designed for use in communication between
security-aware resolvers and security-aware recursive name servers.
These bits are for the most part not relevant to query processing by
security-aware authoritative name servers.
A security-aware name server does not perform signature validation
for authoritative data during query processing, even when the CD bit
is clear. A security-aware name server SHOULD clear the CD bit when
composing an authoritative response.
A security-aware name server MUST NOT set the AD bit in a response
unless the name server considers all RRsets in the Answer and
Authority sections of the response to be authentic. A security-aware
name server's local policy MAY consider data from an authoritative
zone to be authentic without further validation. However, the name
server MUST NOT do so unless the name server obtained the
authoritative zone via secure means (such as a secure zone transfer
mechanism) and MUST NOT do so unless this behavior has been
configured explicitly.
A security-aware name server that supports recursion MUST follow the
rules for the CD and AD bits given in Section 3.2 when generating a
response that involves data obtained via recursion.
fn checking_disabled(&self) -> bool
see is_authentic_data()
fn response_code(&self) -> u8
RCODE Response code - this 4 bit field is set as part of
responses. The values have the following
interpretation: <see super::response_code>
fn query_count(&self) -> u16
QDCOUNT an unsigned 16 bit integer specifying the number of
entries in the question section.
Return value
If this is a query, this will return the number of queries in the query section of the
fn answer_count(&self) -> u16
ANCOUNT an unsigned 16 bit integer specifying the number of
resource records in the answer section.
Return value
For query responses this is the number of records in the answer section, should be 0 for requests, for updates this is the count of prerequisite records.
fn name_server_count(&self) -> u16
for queries this is the nameservers which are authorities for the SOA of the Record
for updates this is the update record count
text NSCOUNT an unsigned 16 bit integer specifying the number of name server resource records in the authority records section.
Return value
For query responses this is the number of authorities, or nameservers, in the name server section, for updates this is the number of update records being sent.
fn additional_count(&self) -> u16
ARCOUNT an unsigned 16 bit integer specifying the number of
resource records in the additional records section.
Return value
This is the additional record section count, this section may include EDNS options.
fn clone(
&self,
query_count: u16,
answer_count: u16,
name_server_count: u16,
additional_count: u16
) -> Self
&self,
query_count: u16,
answer_count: u16,
name_server_count: u16,
additional_count: u16
) -> Self
This is a specialized clone which clones all the fields but the counts handy for setting the count fields before sending over the wire.
Trait Implementations
impl Clone for Header
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fn clone(&self) -> Header
Returns a copy of the value. Read more
fn clone_from(&mut self, source: &Self)
1.0.0
Performs copy-assignment from source
. Read more
impl Debug for Header
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impl PartialEq for Header
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fn eq(&self, __arg_0: &Header) -> bool
This method tests for self
and other
values to be equal, and is used by ==
. Read more
fn ne(&self, __arg_0: &Header) -> bool
This method tests for !=
.
impl PartialOrd for Header
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fn partial_cmp(&self, __arg_0: &Header) -> Option<Ordering>
This method returns an ordering between self
and other
values if one exists. Read more
fn lt(&self, __arg_0: &Header) -> bool
This method tests less than (for self
and other
) and is used by the <
operator. Read more
fn le(&self, __arg_0: &Header) -> bool
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
fn gt(&self, __arg_0: &Header) -> bool
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
fn ge(&self, __arg_0: &Header) -> bool
This method tests greater than or equal to (for self
and other
) and is used by the >=
operator. Read more
impl BinSerializable<Header> for Header
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fn read(decoder: &mut BinDecoder) -> DecodeResult<Self>
Read the type from the stream
fn emit(&self, encoder: &mut BinEncoder) -> EncodeResult
Write the type to the stream