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편집 파일: renderer.cpython-38.pyc
U /?�f�+ � @ sl d Z ddlZddlZddlZddlZddlZddlZddlZdZ dZ dZ dZ ej dd� �ZG dd � d �ZdS ) z*Help for building DNS wire format messages� N� � � c c s� | � d| � | �� }d V | �� }|| }|dkr�zF| �|| � z| � |�|d�� W n tk rv tjj�Y nX W 5 | �|� X d S )N� r �big)�write�tell�seek�to_bytes� OverflowError�dns� exception� FormError)�outputZ length_length�start�end�length� r �:/opt/hc_python/lib/python3.8/site-packages/dns/renderer.py�prefixed_length# s r c @ s� e Zd ZdZd)dd�Zdd� Zd d � Zejd d � �Z ejd d� �Z e j j fdd�Zdd� Zdd� Zd*dd�Zd+dd�Ze jjfdd�Ze jjfdd �Zd d � Zd d � Zd!d"� Zedd#�d$d%�Zdd&�d'd(�Z dS ),�Renderera� Helper class for building DNS wire-format messages. Most applications can use the higher-level L{dns.message.Message} class and its to_wire() method to generate wire-format messages. This class is for those applications which need finer control over the generation of messages. Typical use:: r = dns.renderer.Renderer(id=1, flags=0x80, max_size=512) r.add_question(qname, qtype, qclass) r.add_rrset(dns.renderer.ANSWER, rrset_1) r.add_rrset(dns.renderer.ANSWER, rrset_2) r.add_rrset(dns.renderer.AUTHORITY, ns_rrset) r.add_rrset(dns.renderer.ADDITIONAL, ad_rrset_1) r.add_rrset(dns.renderer.ADDITIONAL, ad_rrset_2) r.add_edns(0, 0, 4096) r.write_header() r.add_tsig(keyname, secret, 300, 1, 0, '', request_mac) wire = r.get_wire() If padding is going to be used, then the OPT record MUST be written after everything else in the additional section except for the TSIG (if any). output, an io.BytesIO, where rendering is written id: the message id flags: the message flags max_size: the maximum size of the message origin: the origin to use when rendering relative names compress: the compression table section: an int, the section currently being rendered counts: list of the number of RRs in each section mac: the MAC of the rendered message (if TSIG was used) Nr � c C sv t �� | _|dkr"t�dd�| _n|| _|| _|| _|| _i | _ t | _ ddddg| _ | j� d� d| _d| _d| _dS )zInitialize a new renderer.Nr r s � F)�io�BytesIOr �random�randint�id�flags�max_size�origin�compress�QUESTION�section�countsr �mac�reserved� was_padded)�selfr r r r r r r �__init__b s zRenderer.__init__c C sV | j �|� | j �� g }| j�� D ]\}}||kr$|�|� q$|D ] }| j|= qDdS )z�Truncate the output buffer at offset *where*, and remove any compression table entries that pointed beyond the truncation point. N)r r �truncater! �items�append)r( �whereZkeys_to_delete�k�vr r r � _rollbacku s zRenderer._rollbackc C s& | j |kr"| j |kr tjj�|| _ dS )a Set the renderer's current section. Sections must be rendered order: QUESTION, ANSWER, AUTHORITY, ADDITIONAL. Sections may be empty. Raises dns.exception.FormError if an attempt was made to set a section value less than the current section. N)r# r r r )r( r# r r r � _set_section� s zRenderer._set_sectionc c s6 | j �� }|V | j �� | jkr2| �|� tjj�d S �N)r r r r0 r r ZTooBig)r( r r r r � _track_size� s zRenderer._track_sizec c s4 | j �� }z| j �|� d V W 5 | j �|� X d S r2 )r r r )r( r- �currentr r r �_temporarily_seek_to� s z Renderer._temporarily_seek_toc C s^ | � t� | �� �0 |�| j| j| j� | j�t� d||�� W 5 Q R X | j t d7 < dS )z Add a question to the message.z!HHr N) r1 r" r3 �to_wirer r! r r �struct�packr$ )r( ZqnameZrdtype�rdclassr r r � add_question� s zRenderer.add_questionc K sL | � |� | �� � |j| j| j| jf|�}W 5 Q R X | 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�r1 r3 r6 r r! r r$ )r( r# Zrrset�kw�nr r r � add_rrset� s "zRenderer.add_rrsetc K sN | � |� | �� � |j|| j| j| jf|�}W 5 Q R X | j| |7 < dS )z�Add the rdataset to the specified section, using the specified name as the owner name. Any keyword arguments are passed on to the rdataset's to_wire() routine. Nr; )r( r# �nameZrdatasetr< r= r r r � add_rdataset� s $zRenderer.add_rdatasetc C s� |r�|j }|dkst�|d }| j�� | | }|| }|rJd|| }nd}t|j�} | �tj� tjj j |�� tj j �||j| �}d| _| �t|� dS )aM Add *opt* to the additional section, applying padding if desired. The padding will take the specified precomputed OPT size and TSIG size into account. Note that we don't have reliable way of knowing how big a GSS-TSIG digest might be, so we we might not get an even multiple of the pad in that case.� r r � TN)�ttl�AssertionErrorr r �list�optionsr, r �ednsZ GenericOptionZ OptionTypeZPADDING�message�Message� _make_optr9 r' r> � ADDITIONAL) r( �opt�padZopt_sizeZ tsig_sizerC Z opt_rdataZsize_without_padding� remainderrF r r r �add_opt� s zRenderer.add_optc C s4 |dM }||d> O }t jj�|||�}| �|� dS )z&Add an EDNS OPT record to the message.l �~ � N)r rH rI rJ rO )r( rG Z ednsflags�payloadrF rL r r r �add_edns� s zRenderer.add_ednsc C s~ | j �� } t|tjj�r |} ntj�|||�} tjj�||d|d|||�} tj� | | | d t t � � �|�\} } | � | |� dS )z$Add a TSIG signature to the message.r rB N� r �getvalue� isinstancer �tsig�KeyrH rI Z _make_tsig�sign�int�time� _write_tsig) r( �keyname�secret�fudger � tsig_error� other_data� request_mac� algorithm�s�keyrV �_r r r �add_tsig� s �$zRenderer.add_tsigc C s� | j �� } t|tjj�r |} ntj�||| �} tjj�|| d|d|||�} tj� | | | d t t � � �||d�\} }| � | |� |S )ay Add a TSIG signature to the message. Unlike add_tsig(), this can be used for a series of consecutive DNS envelopes, e.g. for a zone transfer over TCP [RFC2845, 4.4]. For the first message in the sequence, give ctx=None. For each subsequent message, give the ctx that was returned from the add_multi_tsig() call for the previous message.r rB TrS ) r( �ctxr\ r] r^ r r_ r` ra rb rc rd rV r r r �add_multi_tsig� s2 � � zRenderer.add_multi_tsigc C s� | j r d }n| j}| �t� | �� �\ |�| j|| j� | j�t � dt j j t jjd�� t| jd�� |�| j� W 5 Q R X W 5 Q R X | jt d7 < | �d�� | j�t � d| jt �� W 5 Q R X d S )Nz!HHIr r r � z!H)r' r! r1 rK r3 r6 r r r r7 r8 r Z rdatatypeZTSIG� rdataclass�ANYr r$ r5 )r( rV r\ r! r r r r[ " s � zRenderer._write_tsigc C sT | � d��@ | j�t�d| j| j| jd | jd | jd | jd �� W 5 Q R X 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)r5 r r r7 r8 r r r$ �r( r r r � write_header4 s ��zRenderer.write_headerc C s | j �� S )z Return the wire format message.)r rT rl r r r �get_wireI s zRenderer.get_wire)�size�returnc C sB |dk rt d��|| jkr"t d��| j|7 _| j|8 _dS )zReserve *size* bytes.r z$reserved amount must be non-negativez)cannot reserve more than the maximum sizeN)� ValueErrorr r& )r( ro r r r �reserveN s zRenderer.reserve)rp c C s | j | j7 _ d| _dS )zRelease the reserved bytes.r N)r r& rl r r r �release_reservedW s zRenderer.release_reserved)Nr r N)r r r )N) �__name__� __module__� __qualname__�__doc__r) r0 r1 � contextlib�contextmanagerr3 r5 r rj �INr: r> r@ rO rR rV Zdefault_algorithmrf rh r[ rm rn rY rr rs r r r r r 5 s, , � #� # r )rw rx r r r7 rZ Z dns.exceptionr Zdns.tsigr" ZANSWERZ AUTHORITYrK ry r r r r r r �<module> s