o 2c_"@s^dZddlZddlZddlZddlZddlZddlZddlZdZ dZ dZ dZ GdddZ dS)z*Help for building DNS wire format messagesNc@seZdZdZdddZddZd d Zejd d Z e j j fd dZ ddZddZd ddZe jjfddZe jjfddZddZddZddZdS)!RendereraHelper 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() 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) NrcCsft|_|durtdd|_n||_||_||_||_i|_ t |_ gd|_ |j dd|_dS)zInitialize a new renderer.Nrr)rrrrs )ioBytesIOoutputrandomrandintidflagsmax_sizeorigincompressQUESTIONsectioncountswritemac)selfr rrrrB/var/www/html/gps/gps/lib/python3.10/site-packages/dns/renderer.py__init__Ms    zRenderer.__init__cCsV|j||jg}|jD] \}}||kr||q|D]}|j|=q"dS)zTruncate the output buffer at offset *where*, and remove any compression table entries that pointed beyond the truncation point. N)r seektruncateritemsappend)rwherekeys_to_deletekvrrr _rollback^s    zRenderer._rollbackcCs*|j|kr|j|krtjj||_dSdS)aSet 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)rdns exception FormError)rrrrr _set_sectionms  zRenderer._set_sectionccs8|j}|V|j|jkr||tjjdSN)r tellrr#r$r%TooBig)rstartrrr _track_size|s  zRenderer._track_sizecCsr|t|||j|j|j|jt d||Wdn1s)wY|j td7<dS)zAdd a question to the message.z!HHNr) r'rr,to_wirer rrrstructpackr)rqnamerdtyperdclassrrr add_questions  zRenderer.add_questioncKsd||||j|j|j|jfi|}Wdn1s"wY|j||7<dS)zAdd the rrset to the specified section. Any keyword arguments are passed on to the rdataset's to_wire() routine. Nr'r,r-r rrr)rrrrsetkwnrrr add_rrsets  zRenderer.add_rrsetcKsf||||j||j|j|jfi|}Wdn1s#wY|j||7<dS)zAdd the rdataset to the specified section, using the specified name as the owner name. Any keyword arguments are passed on to the rdataset's to_wire() routine. Nr4)rrnamerdatasetr6r7rrr add_rdatasets  zRenderer.add_rdatasetcCs6|dM}||d>O}tjj|||}|t|dS)z&Add an EDNS OPT record to the message.l~N)r$messageMessage _make_optr8 ADDITIONAL)redns ednsflagspayloadoptionsoptrrradd_ednss zRenderer.add_ednsc Cs~|j} t|tjjr|} ntj|||} tjj||d|d|||} tj | | | dt t |\} } | | |dS)z$Add a TSIG signature to the message.rN r getvalue isinstancer$tsigKeyr=r> _make_tsigsigninttime _write_tsig) rkeynamesecretfudger tsig_error other_data request_mac algorithmskeyrK_rrradd_tsigs zRenderer.add_tsigc Cs|j} t|tjjr|} ntj||| } tjj|| d|d|||} tj | | | dt t ||d\} }| | ||S)ayAdd 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.rrGTrH) rctxrRrSrTr rUrVrWrXrYrZrKrrradd_multi_tsigs  zRenderer.add_multi_tsigc Cs|t|.||j|j|j|jt dt j j t j jdd|j}||jWdn1s:wY|j}|j|d|jt d|||jtd7<|jd|jt d|jt|jdtjdS)Nz!HHIHrrz!Hr )r'r@r,r-r rrrr.r/r$ rdatatypeTSIG rdataclassANYr)rrrSEEK_END)rrKrR rdata_startafterrrrrQs      zRenderer._write_tsigc CsZ|jd|jtd|j|j|jd|jd|jd|jd|jdtj dS)zWrite 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. rz!HHHHHHrrrN) r rrr.r/r rrrrdrrrr write_headers zRenderer.write_headercCs |jS)zReturn the wire format message.)r rIrgrrrget_wires zRenderer.get_wire)NrrNr()__name__ __module__ __qualname____doc__rr#r' contextlibcontextmanagerr,r$rbINr3r8r;rFrKdefault_algorithmr\r^rQrhrirrrrr$s$ (      r)rmrnrr.r rP dns.exceptionr$dns.tsigrANSWER AUTHORITYr@rrrrrs