Edit File: renderer.cpython-36.pyc
3 �b�W�. � @ sh d Z ddlmZ ddlZddlZddlZddlZddlZddl m Z dZ dZ dZ dZG dd � d e�ZdS ) z*Help for building DNS wire format messages� )�BytesION� )�long� � c @ st e Zd ZdZddd�Zdd� Zd d � Zejj fd d �Z d d� Z dd� Z ddd�Z ejjfdd�Zdd� Zdd� ZdS )�Rendererai 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_edns(0, 0, 4096) r.add_rrset(dns.renderer.ADDTIONAL, ad_rrset_1) r.add_rrset(dns.renderer.ADDTIONAL, ad_rrset_2) r.write_header() r.add_tsig(keyname, secret, 300, 1, 0, '', request_mac) wire = r.get_wire() @ivar output: where rendering is written @type output: BytesIO object @ivar id: the message id @type id: int @ivar flags: the message flags @type flags: int @ivar max_size: the maximum size of the message @type max_size: int @ivar origin: the origin to use when rendering relative names @type origin: dns.name.Name object @ivar compress: the compression table @type compress: dict @ivar section: the section currently being rendered @type section: int (dns.renderer.QUESTION, dns.renderer.ANSWER, dns.renderer.AUTHORITY, or dns.renderer.ADDITIONAL) @ivar counts: list of the number of RRs in each section @type counts: int list of length 4 @ivar mac: the MAC of the rendered message (if TSIG was used) @type mac: string Nr � c C sh t � | _|dkr tjdd�| _n|| _|| _|| _|| _i | _t | _ ddddg| _ | jj d� d| _ dS )a� Initialize a new renderer. @param id: the message id @type id: int @param flags: the DNS message flags @type flags: int @param max_size: the maximum message size; the default is 65535. If rendering results in a message greater than I{max_size}, then L{dns.exception.TooBig} will be raised. @type max_size: int @param origin: the origin to use when rendering relative names @type origin: dns.name.Name or None. Nr i�� � � � s )r �output�randomZrandint�id�flags�max_size�origin�compress�QUESTION�section�counts�write�mac)�selfr r r r � r � /usr/lib/python3.6/renderer.py�__init__N s zRenderer.__init__c C s^ | j j|� | j j� g }x(| jj� D ]\}}||kr&|j|� q&W x|D ] }| j|= qJW dS )z�Truncate the output buffer at offset I{where}, and remove any compression table entries that pointed beyond the truncation point. @param where: the offset @type where: int N)r �seek�truncater �items�append)r �whereZkeys_to_delete�k�vr r r � _rollbackk s zRenderer._rollbackc C s& | j |kr"| j |kr tjj�|| _ dS )aZ Set the renderer's current section. Sections must be rendered order: QUESTION, ANSWER, AUTHORITY, ADDITIONAL. Sections may be empty. @param section: the section @type section: int @raises dns.exception.FormError: an attempt was made to set a section value less than the current section. N)r �dns� exceptionZ FormError)r r r r r � _set_section} s zRenderer._set_sectionc C sz | j t� | jj� }|j| j| j| j� | jjtj d||�� | jj� }|| j krd| j |� t j j�| jt d7 < dS )a Add a question to the message. @param qname: the question name @type qname: dns.name.Name @param rdtype: the question rdata type @type rdtype: int @param rdclass: the question rdata class @type rdclass: int z!HHr N)r& r r �tell�to_wirer r r �struct�packr r# r$ r% �TooBigr )r ZqnameZrdtypeZrdclass�before�afterr r r � add_question� s zRenderer.add_questionc K sh | j |� | jj� }|j| j| j| jf|�}| jj� }|| jkrR| j|� tj j �| j | |7 < dS )a Add the rrset to the specified section. Any keyword arguments are passed on to the rdataset's to_wire() routine. @param section: the section @type section: int @param rrset: the rrset @type rrset: dns.rrset.RRset object N) r& r r' r( r r r r# r$ r% r+ r )r r Zrrset�kwr, �nr- r r r � add_rrset� s zRenderer.add_rrsetc K sj | j |� | jj� }|j|| j| j| jf|�}| jj� }|| jkrT| j|� tj j �| j | |7 < dS )a� 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. @param section: the section @type section: int @param name: the owner name @type name: dns.name.Name object @param rdataset: the rdataset @type rdataset: dns.rdataset.Rdataset object N) r& r r' r( r r r r# r$ r% r+ r )r r �nameZrdatasetr/ r, r0 r- r r r � add_rdataset� s zRenderer.add_rdatasetc C s� |t d�M }||d> O }| jt� | jj� }| jjtjddtj j ||d�� |dk �rJ| jj� }x�|D ]�}tjd|j d�}| jj|� | jj� } |j | j� | jj� } | | dk s�t �| jj| d � tjd | | �}| jj|� | jjdd� qfW | jj� } | | dk �st �| jj|d � tjd | | �}| jj|� | jjdd� | jj� } | | jk�rr| j|� tjj�| jt d 7 < dS ) a� Add an EDNS OPT record to the message. @param edns: The EDNS level to use. @type edns: int @param ednsflags: EDNS flag values. @type ednsflags: int @param payload: The EDNS sender's payload field, which is the maximum size of UDP datagram the sender can handle. @type payload: int @param options: The EDNS options list @type options: list of dns.edns.Option instances @see: RFC 2671 l �~ � z!BHHIHr Nz!HHi r z!Hr )r r& � ADDITIONALr r' r r) r* r$ � rdatatype�OPTZotyper( �AssertionErrorr r r# r% r+ r ) r ZednsZ ednsflagsZpayloadZoptionsr, Zlstart�optZstuff�start�endZlendr- r r r �add_edns� s< zRenderer.add_ednsc C sB | j t� | jj� } | jj� } tjj| ||tt j � �||||||d� \} | _ } |j | j| j | j � | jjtjdtjjtjjdd�� | jj� } | jj| � | jj� }|| dk s�t�|| jkr�| j| � tjj�| jj| d � | jjtjd|| �� | jt d7 < | jjd� | jjtjd| jt �� | jjdd� d S ) a� Add a TSIG signature to the message. @param keyname: the TSIG key name @type keyname: dns.name.Name object @param secret: the secret to use @type secret: string @param fudge: TSIG time fudge @type fudge: int @param id: the message id to encode in the tsig signature @type id: int @param tsig_error: TSIG error code; default is 0. @type tsig_error: int @param other_data: TSIG other data. @type other_data: string @param request_mac: This message is a response to the request which had the specified MAC. @type request_mac: string @param algorithm: the TSIG algorithm to use @type algorithm: dns.name.Name object )� algorithmz!HHIHr i r z!Hr � N) r& r5 r r' �getvaluer$ �tsigZsign�int�timer r( r r r r) r* r6 ZTSIG� rdataclass�ANYr8 r r# r% r+ r r )r ZkeynameZsecretZfudger Z tsig_errorZ other_dataZ request_macr= r, �sZ tsig_rdataZctxZ rdata_startr- r r r �add_tsig s: zRenderer.add_tsigc C sX | j jd� | j jtjd| j| j| jd | jd | jd | jd �� | j jdd� 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)r r r r) r* r r r )r r r r � write_header5 s zRenderer.write_headerc C s | j j� S )z@Return the wire format message. @rtype: string )r r? )r r r r �get_wireC s zRenderer.get_wire)Nr r N)N)�__name__� __module__� __qualname__�__doc__r r# r& r$ rC �INr. r1 r3 r< r@ Zdefault_algorithmrF rG rH r r r r r " s * 04r )rL �ior r) r rB Z dns.exceptionr$ Zdns.tsigZ_compatr r ZANSWERZ AUTHORITYr5 �objectr r r r r �<module> s
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