File: //lib/python3.9/site-packages/dns/__pycache__/renderer.cpython-39.opt-1.pyc
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z*Help for building DNS wire format messages� N� � � c c s� | � d| � | �� }d V | �� }|| }|dkr�zN| �|| � z| � |�|d�� W n tyt tjj�Y n0 W | �|� n | �|� 0 d S )N� r Zbig)�write�tell�seek�to_bytes�
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length_length�start�end�length� r �0/usr/lib/python3.9/site-packages/dns/renderer.py�prefixed_length# s r c @ s� e Zd ZdZd)dd�Zdd� Zd d
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fdd�Zdd� Zdd� Zd*dd�Zd+dd�Ze jjfdd�Ze jjfdd �Zd d � Zd d � Zd!d"� Zedd#�d$d%�Zdd&�d'd(�Z dS ),�Renderera� Helper class for building DNS wire-format messages.
Most applications can use the higher-level L{dns.message.Message}
class and its to_wire() method to generate wire-format messages.
This class is for those applications which need finer control
over the generation of messages.
Typical use::
r = dns.renderer.Renderer(id=1, flags=0x80, max_size=512)
r.add_question(qname, qtype, qclass)
r.add_rrset(dns.renderer.ANSWER, rrset_1)
r.add_rrset(dns.renderer.ANSWER, rrset_2)
r.add_rrset(dns.renderer.AUTHORITY, ns_rrset)
r.add_rrset(dns.renderer.ADDITIONAL, ad_rrset_1)
r.add_rrset(dns.renderer.ADDITIONAL, ad_rrset_2)
r.add_edns(0, 0, 4096)
r.write_header()
r.add_tsig(keyname, secret, 300, 1, 0, '', request_mac)
wire = r.get_wire()
If padding is going to be used, then the OPT record MUST be
written after everything else in the additional section except for
the TSIG (if any).
output, an io.BytesIO, where rendering is written
id: the message id
flags: the message flags
max_size: the maximum size of the message
origin: the origin to use when rendering relative names
compress: the compression table
section: an int, the section currently being rendered
counts: list of the number of RRs in each section
mac: the MAC of the rendered message (if TSIG was used)
Nr � c C sr t �� | _|du r"t�dd�| _n|| _|| _|| _|| _i | _ t
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d� d| _d| _d| _dS )zInitialize a new renderer.Nr r )r r r r s � F)�io�BytesIOr �randomZrandint�id�flags�max_size�origin�compress�QUESTION�section�countsr Zmac�reserved�
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zRenderer.__init__c C sV | j �|� | j �� g }| j�� D ]\}}||kr$|�|� q$|D ] }| j|= qDdS )z�Truncate the output buffer at offset *where*, and remove any
compression table entries that pointed beyond the truncation
point.
N)r r �truncater �items�append)r% �whereZkeys_to_delete�k�vr r r � _rollbacku s
zRenderer._rollbackc C s& | j |kr"| j |kr tjj�|| _ dS )a Set the renderer's current section.
Sections must be rendered order: QUESTION, ANSWER, AUTHORITY,
ADDITIONAL. Sections may be empty.
Raises dns.exception.FormError if an attempt was made to set
a section value less than the current section.
N)r! r r r
)r% r! r r r � _set_section� s
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z Renderer._temporarily_seek_toc C sr | � t� | �� �: |�| j| j| j� | j�t� d||�� W d � n1 sR0 Y | j
t d7 < dS )z Add a question to the message.z!HHNr ) r. r r0 �to_wirer r r r �struct�packr" )r% ZqnameZrdtype�rdclassr r r � add_question� s
4zRenderer.add_questionc K sd | � |� | �� �, |j| j| j| jfi |��}W d � n1 sD0 Y | j| |7 < dS )z�Add the rrset to the specified section.
Any keyword arguments are passed on to the rdataset's to_wire()
routine.
N�r. r0 r3 r r r r" )r% r! Zrrset�kw�nr r r � add_rrset� s
:zRenderer.add_rrsetc K sf | � |� | �� �. |j|| j| j| jfi |��}W d � n1 sF0 Y | j| |7 < dS )z�Add the rdataset to the specified section, using the specified
name as the owner name.
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Nr8 )r% r! �nameZrdatasetr9 r: r r r � add_rdataset� s
<zRenderer.add_rdatasetc
C s� |r�|j }|d }| j�� | | }|| }|r>d|| }nd}t|j�} | �tj�tjj j
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||j| �}d| _| �t|� dS )aM Add *opt* to the additional section, applying padding if desired. The
padding will take the specified precomputed OPT size and TSIG size into
account.
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might be, so we we might not get an even multiple of the pad in that case.r r � TN)�ttlr r �list�optionsr) r �ednsZ
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r% �optZpadZopt_sizeZ tsig_sizer? Z opt_rdataZsize_without_paddingZ remainderrA r r r �add_opt� s
zRenderer.add_optc C s4 |dM }||d> O }t jj�|||�}| �|� dS )z&Add an EDNS OPT record to the message.l �~ � N)r rC rD rE rH )r% rB Z ednsflagsZpayloadrA rG r r r �add_edns� s zRenderer.add_ednsc
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t � � �||d�\} }| � | |� |S )ay Add a TSIG signature to the message. Unlike add_tsig(), this can be
used for a series of consecutive DNS envelopes, e.g. for a zone
transfer over TCP [RFC2845, 4.4].
For the first message in the sequence, give ctx=None. For each
subsequent message, give the ctx that was returned from the
add_multi_tsig() call for the previous message.r r> TrK )
r% �ctxrS rT rU r rV rW rX rY rZ r[ rN r r r �add_multi_tsig� s
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C sh | � d��J | j�t�d| j| j| jd | jd | jd | jd �� W d � n1 sZ0 Y dS )z�Write the DNS message header.
Writing the DNS message header is done after all sections
have been rendered, but before the optional TSIG signature
is added.
r z!HHHHHHr r r N)r2 r r r4 r5 r r r" �r% r r r � write_header4 s ��zRenderer.write_headerc C s
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