J*ndZddlmZddlZddlZddlZddlZddlZddl m Z dZ dZ dZ dZGdd eZy) z*Help for building DNS wire format messages)BytesION)longceZdZdZddZdZdZejjfdZ dZ dZ dd Z ejjfd Zejjfd Zd Zd ZdZy)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, a 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) Nct|_|tjdd|_n||_||_||_||_i|_t|_ gd|_ |jjdd|_ y)zInitialize a new renderer.Nr)rrrrs )routputrandomrandintidflagsmax_sizeorigincompressQUESTIONsectioncountswritemac)selfrrrrs lib/third_party/dns/renderer.py__init__zRenderer.__init__Msni :nnQ.DGDG      "  ,'c |jj||jjg}|jj D]\}}||k\s |j ||D]}|j|=y)zTruncate the output buffer at offset *where*, and remove any compression table entries that pointed beyond the truncation point. N)r seektruncateritemsappend)rwherekeys_to_deletekvs r _rollbackzRenderer._rollback^ss  MM'')DAqEz%%a(* A a  rc|j|k7r1|j|kDrtjj||_yy)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)rrs r _set_sectionzRenderer._set_sectionms8 <<7 "||g%mm---"DL #rc|jt|jj}|j |j|j |j |jjtjd|||jj}||jk\r+|j|tjj|jtxxdz cc<y)zAdd a question to the message.!HHrN)r,rr tellto_wirerrrstructpackrr'r)r*TooBigr)rqnamerdtyperdclassbeforeafters r add_questionzRenderer.add_question|s (#!!# dkk4==$++> &++eVW=>   " DMM ! NN6 "--&& & H"rc |j||jj}|j|j|j|j fi|}|jj}||j k\r+|j|tjj|j|xx|z cc<y)zAdd the rrset to the specified section. Any keyword arguments are passed on to the rdataset's to_wire() routine. N r,r r/r0rrrr'r)r*r3r)rrrrsetkwr7nr8s r add_rrsetzRenderer.add_rrsets '"!!# EMM$++t}}dkk HR H   " DMM ! NN6 "--&& & G!rc |j||jj}|j||j|j|j fi|}|jj}||j k\r+|j|tjj|j|xx|z cc<y)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. Nr;)rrnamerdatasetr=r7r>r8s r add_rdatasetzRenderer.add_rdatasets '"!!# H  T4;; t{{ #! #   " DMM ! NN6 "--&& & G!rc x|tdz}||dzz}|jt|jj }|jj t jddtjj||d||jj }|D]}t jd|jd}|jj ||jj } |j|j|jj } | | z dksJ|jj| dz t jd | | z }|jj ||jjdd |jj } | |z dksJ|jj|dz t jd | |z }|jj ||jjdd|jj } | |jk\r+|j|tj j"|j$txxd z cc<y) z&Add an EDNS OPT record to the message.l~z!BHHIHrNr.r!Hr)rr, ADDITIONALr r/rr1r2r) rdatatypeOPTotyper0rrr'r*r3r) redns ednsflagspayloadoptionsr7lstartoptstuffstartendlendr8s radd_ednszRenderer.add_ednss T*%% dbj!  *%!!# &++h3==3D3Dg&/4 5  [[%%'F E399a8 !!%( ((* DKK(kk&&(U{U***   + D#+6 !!%(   A&;;##%D&=5( (( KK  VaZ (KKdVm4E KK  e $ KK  Q "   " DMM ! NN6 "--&& & J1$rc |jj} tjj | ||t t j |||||| \} |_} |j| |y)z$Add a TSIG signature to the message.) algorithmN r getvaluer)tsigsigninttimer _write_tsig) rkeynamesecretfudger tsig_error other_data request_macrXs tsig_rdatactxs radd_tsigzRenderer.add_tsigsq KK "&)hhmmA4;4:47 4D49464>4>4?>G'4 'I#TXs W-rc |jj} tjj | ||t t j |||||||dud|  \} |_}|j| ||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.NT)rhfirstmultirXrY) rrhr`rarbrrcrdrerXrfrgs radd_multi_tsigzRenderer.add_multi_tsigs KK "&)hhmmA4;4:47 4D49464>4>4?8;:=+:>>G'4 'I#TXs W- rc r|jt|jj}|j |j|j |j |jjtjdtjjtjjdd|jj}|jj||jj}||z dksJ||jk\r+|j!|tj"j$|jj'|dz |jjtjd||z |j(txxdz cc<|jj'd|jjtjd|j(t|jj'ddy)Nz!HHIHrrFrrGr )r,rHr r/r0rrrr1r2r)rITSIG rdataclassANYrr'r*r3rr)rrgr`r7 rdata_startr8s rr_zRenderer._write_tsigs *%!!# T]]DKK@ &++gs}}/A/A&)nn&8&8!Q@ Akk&&(  *%   "{"U*** DMM ! NN6 "--&& & q) &++dEK,?@A J1$  &++dDKK ,CDE Arc j|jjd|jjtjd|j |j |jd|jd|jd|jd|jjddy)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 rrr1r2rrrrs r write_headerzRenderer.write_headers  &++i$**&*kk!ndkk!n&*kk!ndkk!nF G Arc6|jjS)zReturn the wire format message.)r rZrus rget_wirezRenderer.get_wire s{{##%%r)Nrr N)N)__name__ __module__ __qualname____doc__rr'r,r)rqINr9r?rCrVr[default_algorithmrirmr_rvrxrrr r $sr&P" ! #36..2C2C #" "$!%H),(B(B.&"%!;!;8. &rr )r|iorr1rr^ dns.exceptionr)dns.tsig_compatrrANSWER AUTHORITYrHobjectr rrrrsC$1     &v&r