Summary of bug: Deadwood was unable to resolve a name where the IP for a glueless NS referral was one that never appears in the AN section of a DNS reply because of a misconfigured DNS server. To wit: $ askmara Aoncetv-ipn.net. 198.41.0.4 # Querying the server with the IP 198.41.0.4 # Question: Aoncetv-ipn.net. # NS replies: #net. +172800 ns a.gtld-servers.net. #net. +172800 ns b.gtld-servers.net. #net. +172800 ns c.gtld-servers.net. #net. +172800 ns d.gtld-servers.net. #net. +172800 ns e.gtld-servers.net. #net. +172800 ns f.gtld-servers.net. #net. +172800 ns g.gtld-servers.net. #net. +172800 ns h.gtld-servers.net. #net. +172800 ns i.gtld-servers.net. #net. +172800 ns j.gtld-servers.net. #net. +172800 ns k.gtld-servers.net. #net. +172800 ns l.gtld-servers.net. #net. +172800 ns m.gtld-servers.net. # AR replies: #a.gtld-servers.net. +172800 a 192.5.6.30 #b.gtld-servers.net. +172800 a 192.33.14.30 #c.gtld-servers.net. +172800 a 192.26.92.30 #d.gtld-servers.net. +172800 a 192.31.80.30 #e.gtld-servers.net. +172800 a 192.12.94.30 #f.gtld-servers.net. +172800 a 192.35.51.30 #g.gtld-servers.net. +172800 a 192.42.93.30 #h.gtld-servers.net. +172800 a 192.54.112.30 #i.gtld-servers.net. +172800 a 192.43.172.30 #j.gtld-servers.net. +172800 a 192.48.79.30 #k.gtld-servers.net. +172800 a 192.52.178.30 #l.gtld-servers.net. +172800 a 192.41.162.30 #m.gtld-servers.net. +172800 a 192.55.83.30 #a.gtld-servers.net. +172800 aaaa 2001:503:a83e:0:0:0:2:30 $ askmara Aoncetv-ipn.net. 192.5.6.30 # Querying the server with the IP 192.5.6.30 # Question: Aoncetv-ipn.net. # NS replies: oncetv-ipn.net. +172800 ns ns01.canaloncesi.tv. oncetv-ipn.net. +172800 ns ns02.canaloncesi.tv. # AR replies: $ askmara Ans01.canaloncesi.tv. 198.41.0.4 # Querying the server with the IP 198.41.0.4 # Question: Ans01.canaloncesi.tv. # NS replies: #tv. +172800 ns l5.nstld.com. #tv. +172800 ns h5.nstld.com. #tv. +172800 ns g5.nstld.com. #tv. +172800 ns f5.nstld.com. #tv. +172800 ns d5.nstld.com. #tv. +172800 ns c5.nstld.com. #tv. +172800 ns a5.nstld.com. # AR replies: #l5.nstld.com. +172800 a 192.41.162.34 #h5.nstld.com. +172800 a 192.54.112.34 #h5.nstld.com. +172800 aaaa 2001:502:8cc:0:0:0:2:34 #g5.nstld.com. +172800 a 192.42.93.34 #f5.nstld.com. +172800 a 192.35.51.34 #f5.nstld.com. +172800 aaaa 2001:503:d414:0:0:0:2:34 #d5.nstld.com. +172800 a 192.31.80.34 #c5.nstld.com. +172800 a 192.26.92.34 #a5.nstld.com. +172800 a 192.5.6.34 $ askmara Ans01.canaloncesi.tv. 192.41.162.34 # Querying the server with the IP 192.41.162.34 # Question: Ans01.canaloncesi.tv. # NS replies: #canaloncesi.tv. +172800 ns ns01.canaloncesi.tv. #canaloncesi.tv. +172800 ns ns02.canaloncesi.tv. # AR replies: ns01.canaloncesi.tv. +172800 a 192.99.17.117 #ns02.canaloncesi.tv. +172800 a 192.99.17.117 $ askmara Ans01.canaloncesi.tv. 192.99.17.117 # Querying the server with the IP 192.99.17.117 # Remote server said: NAME ERROR # Question: Ans01.canaloncesi.tv. # NS replies: #canaloncesi.tv. +10800 soa ns5002137.ip-192-99-17.net. dserrano@oncetvmexico.ipn.mx. 2013112303 10800 3600 604800 10800 # AR replies: $ askmara Ans02.canaloncesi.tv. 192.99.17.117 # Querying the server with the IP 192.99.17.117 # Remote server said: NAME ERROR # Question: Ans02.canaloncesi.tv. # NS replies: #canaloncesi.tv. +10800 soa ns5002137.ip-192-99-17.net. dserrano@oncetvmexico.ipn.mx. 2013112303 10800 3600 604800 10800 # AR replies: Deadwood was unable to resolve oncetv-ipn.net. My fix: Allow an answer in the AR section that is a direct answer to our question (we will have to move the answer to the AR section, but it will save an additional DNS query in a lot of cases, so has value beyond oncetv-ipn.net) The fix: dwx_determine_answer_type() is now able to look for a direct answer in the AR section of their reply. If this happens, said answer is to be converted in to a "TYPE_ANSWER" packet; we move a single answer from the AR to the AN section. The resulting code, dwx_answer_in_ar(), looks like a combination of dwx_remake_complete_reply() and dwx_copy_over_section() --- deadwood-3.2.04/src/DwRecurse.h.orig 2013-12-03 02:15:15.000000000 -0500 +++ deadwood-3.2.04/src/DwRecurse.h 2013-12-03 02:41:20.000000000 -0500 @@ -56,6 +56,7 @@ #define RRX_IGNORE 36 /* Do not use this record */ #define RRX_OOB_NS 37 /* NS record with bad bailiwick (Out-Of-Bailiwick) */ +#define RRX_ANSWER_IN_AR 38 /* Answer to question in AR section */ /* These are used for linking A and AAAA glue records in the AR section of * a DNS reply with NS records in the NS section; the ranges for both * must be the same */ @@ -77,6 +78,7 @@ #define TYPE_NO_USEFUL_DATA 19 #define TYPE_ERROR 20 #define TYPE_UPSTREAM_REFER 22 /* Upstream server; set RD and stop here */ +#define TYPE_ANSWER_IN_AR 23 /* Answer only in AR section of reply */ /* These won't be used by Deadwood, but may be useful if I ever * expand DwHash to support for datatypes for elements besides * strings. --- deadwood-3.2.04/src/DwRecurse.c.orig 2013-12-03 02:15:20.000000000 -0500 +++ deadwood-3.2.04/src/DwRecurse.c 2013-12-03 04:46:07.000000000 -0500 @@ -1418,7 +1418,7 @@ * sent us, determine what type of reply it is (direct answer, full CNAME * chain referral, incomplete CNAME chain referral, or NS referral) */ -int dwx_determine_answer_type(dns_details *view, dw_str *query) { +int dwx_determine_answer_type(dns_details *view, dw_str *query, dw_str *in) { int32_t query_type = 0; int counter = 0; int max = 32; @@ -1476,6 +1476,16 @@ return TYPE_NOT_THERE; /* May be NXDOMAIN; look at header */ } if(view->ns_types[0] == RR_NS) { + /* oncetv-ipn.net fix; also speeds up Deadwood */ + for(index = 0; index < view->look->arcount * 2; index +=2) { + if(dwx_dname_issame_2dw(query,0,in, + view->look->ar[index]) == 1 && + dw_fetch_u16(in,view->look->ar[index + 1]) == + query_type) { + view->ar_types[(index >> 1)]=RRX_ANSWER_IN_AR; + return TYPE_ANSWER_IN_AR; + } + } return TYPE_NS_REFER; } return TYPE_NO_USEFUL_DATA; @@ -1557,6 +1567,51 @@ return out; } +/* oncetv-ipn.net fix: If the answer is in the AR section, we return + * a packet where that answer (singular for the simple reason coding for + * multiple is more difficult and no one is paying me to write this code) + * is moved to the AN section */ +dw_str *dwx_answer_in_ar(dns_details *view, dw_str *in) { + dw_str *tmp = 0, *out = 0; + int32_t dname_len = 0; + int index = 0; + + if(view == 0 || in == 0) { + return 0; /* Sanity test */ + } + + for(index = 0; index < view->look->arcount; index++) { + if(view->ar_types[index] == RRX_ANSWER_IN_AR && tmp == 0) { + tmp = dwx_get_1_dns_rr(in,view->look->ar[index * 2]); + dname_len = view->look->ar[(index * 2) + 1] - + view->look->ar[index * 2]; + } + } + + if(tmp == 0) { + return 0; + } + out = dw_create(tmp->len + 14); + if(out == 0) { + dw_destroy(tmp); + return 0; + } + if(dw_append(tmp,out) == -1 || + dw_push_u16(0,out) == -1 || /* Offset 1: Top of string */ + dw_push_u16(dname_len,out) == -1 || /* Offset 2: End of dname */ + dw_push_u16(1,out) == -1 || /* One answer */ + dw_push_u16(0,out) == -1 || /* No NS records */ + dw_push_u16(0,out) == -1 || /* No AR records (moved to AN) */ + dw_addchar(TYPE_ANSWER,out) == -1) { + dw_destroy(tmp); + dw_destroy(out); + return 0; + } + + dw_destroy(tmp); + return out; +} + /* Look at a DNS reply and determine how to proceed * * Input: The reply we got ("in"), and the query we sent ("query") @@ -1592,7 +1647,14 @@ dwx_cleanup_ns_ar(view) == -1) { goto catch_dwx_dissect_packet; } - type = dwx_determine_answer_type(view,query); + type = dwx_determine_answer_type(view,query,in); + if(type == TYPE_ANSWER_IN_AR) { + out = dwx_answer_in_ar(view, in); + if(view != 0) { + dwx_zap_dns_details(view); + } + return out; + } if(type == TYPE_NS_REFER && ( dwx_check_bailiwick_ns_section(view,query,bailiwick) == -1 || dwx_link_ns_records(view) == -1 )) { @@ -2532,6 +2594,9 @@ } } + if(place == 0) { + goto catch_dwx_get_rr_from_answer; + } place = dwr_rng(rng_seed) % place; type = dw_fetch_u16(answer,stack[place]); if(type == RR_A) {