On 27.10.2015 15:49, Pasi Sjöholm wrote: > On 27.10.2015 15:00, SpiderX wrote: >> This was fixed once (see commit >> http://git.kernel.org/cgit/network/connman/connman.git/commit/src/dnsproxy.c?h=1.30&id=0439194ed0c5a90f61dbef86d9a51307764da2d7), >> but then was refactored in later commits
Technically that commit is still working but the thing is that the uncompress() and forward_dns_reply() are not able to handle few special cases. > I'm able to reproduce the issue. However it seems that connman's > dnsproxy properly caches the response, so if I do "host -v -t a bz" > immediately after the first query there will be a proper response. Ok, it's not ConnMan's cache from where the response comes correctly on the next time. The issue is: 1) Some upstream DNS-servers add details in the Authority and additional sections of the reply when being queried. Eg. dnsmasq does this on this on replies not coming from it's cache but for ones coming from the cache it replies only the asked records. First query: host -t a -v bz.siirappi.com --cut-- ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 31498 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 3 ;; QUESTION SECTION: ;bz.siirappi.com. IN A ;; ANSWER SECTION: bz.siirappi.com. 60 IN A 1.2.3.4 ;; AUTHORITY SECTION: siirappi.com. 3367 IN NS ns2.afraid.org. siirappi.com. 3367 IN NS ns1.siirappi.com. ;; ADDITIONAL SECTION:http://git.kernel.org/cgit/network/connman/connman.git/tree/src/dnsproxy.c#n2056 ns1.siirappi.com. 60 IN AAAA 2001:41d0:8:196a::2 ns2.afraid.org. 67 IN A 208.43.71.243 ns2.afraid.org. 67 IN AAAA 2607:f0d0:3001:92::2 --cut-- Second query (from cache): --cut-- ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 53006 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;bz.siirappi.com. IN A ;; ANSWER SECTION: bz.siirappi.com. 53 IN A 1.2.3.4 --cut-- 2) As a workaround Google's public DNS-servers seem not to have any authority / additional sections in their replies. Those should work ok. 3) For me the uncompress() returns null when being asked to uncompress nscount from the replies and that's enough for it to bail out. (http://git.kernel.org/cgit/network/connman/connman.git/tree/src/dnsproxy.c#n2056) --cut-- connmand[10470]: src/dnsproxy.c:forward_dns_reply() req 0x18c02b0 dstid 0x8fe0 altid 0x0865 rcode 0 connmand[10470]: src/dnsproxy.c:uncompress() count 1 ptr 0xbe9d2575 end 0xbe9d260b uptr 0xbe9d2128 connmand[10470]: src/dnsproxy.c:uncompress() pos 2 ulen 16 left 1017 name bsiirappicom connmand[10470]: src/dnsproxy.c:uncompress() count 2 ptr 0xbe9d2585 end 0xbe9d260b uptr 0xbe9d2147 connmand[10470]: src/dnsproxy.c:uncompress() pos 2 ulen 13 left 986 namesiirappicom connmand[10470]: src/dnsproxy.c:uncompress() pos 6 ulen 17 left 962 name nssiirappicom connmand[10470]: src/dnsproxy.c:uncompress() failed dns_class != ns_c_in --cut-- So I guess the bug itself is in the uncompress()-function. JukkaR: can you please help me with this one as you know how the uncompress() should work? Br, Pasi _______________________________________________ connman mailing list connman@connman.net https://lists.connman.net/mailman/listinfo/connman
