Re: searchdns does not work in connman 1.30
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=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. 3367IN NS ns2.afraid.org. siirappi.com. 3367IN 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 2001:41d0:8:196a::2 ns2.afraid.org. 67 IN A 208.43.71.243 ns2.afraid.org. 67 IN 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
searchdns does not work in connman 1.30
Hello, # connmand -v 1.30 Here is current service config: connmanctl> services ethernet_64315095faf8_cable /net/connman/service/ethernet_64315095faf8_cable Type = ethernet Security = [ ] State = online Favorite = True Immutable = False AutoConnect = True Name = Wired Ethernet = [ Method=auto, Interface=enp37s0, Address=64:31:50:95:FA:F8, MTU=1500 ] IPv4 = [ Method=dhcp, Address=10.21.5.154, Netmask=255.255.255.0, Gateway=10.21.5.250 ] IPv4.Configuration = [ Method=dhcp ] IPv6 = [ ] IPv6.Configuration = [ Method=off ] Nameservers = [ 91.193.69.4, 91.193.69.22 ] Nameservers.Configuration = [ ] Timeservers = [ 10.21.5.250, ntp.time.in.ua, ntp2.time.in.ua, ntp3.time.in.ua ] Timeservers.Configuration = [ ] Domains = [ gts.dp.ua ] Domains.Configuration = [ gts.dp.ua ] Proxy = [ Method=direct ] Proxy.Configuration = [ ] Provider = [ ] Domains = [ gts.dp.ua ]. so gts.dp.ua should be appended to dns query. ~ $ host -v nefrit1 Trying "nefrit1" Host nefrit1 not found: 3(NXDOMAIN) Received 100 bytes from 127.0.0.1#53 in 0 ms tcpdump: # tcpdump -npi enp37s0 port 53 dropped privs to tcpdump tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on enp37s0, link-type EN10MB (Ethernet), capture size 262144 bytes 14:27:51.032322 IP 10.21.5.154.32905 > 91.193.69.4.53: 51887+ A? nefrit1. (25) 14:27:51.032337 IP 10.21.5.154.32905 > 91.193.69.4.53: 84+ A? nefrit1.gts.dp.ua. (35) 14:27:51.032345 IP 10.21.5.154.59459 > 91.193.69.22.53: 51887+ A? nefrit1. (25) 14:27:51.032350 IP 10.21.5.154.59459 > 91.193.69.22.53: 84+ A? nefrit1.gts.dp.ua. (35) 14:27:51.032760 IP 91.193.69.22.53 > 10.21.5.154.59459: 51887 NXDomain 0/1/0 (100) 14:27:51.032773 IP 91.193.69.22.53 > 10.21.5.154.59459: 84* 1/2/2 A 91.193.69.12 (119) 14:27:51.033253 IP 91.193.69.4.53 > 10.21.5.154.32905: 84 1/2/2 A 91.193.69.12 (119) 14:27:51.040717 IP 91.193.69.4.53 > 10.21.5.154.32905: 51887 NXDomain 0/1/0 (100) So, we have two queries to two nameservers. Two of them have returned NXDomain, and this result was sent back to a client. I think this behaviour is wrong, client shouldn't get NXDomain when other non-nxdomain replies from nameservers exist. This was fixed once (see commit http://git.kernel.org/cgit/network/connman/connman.git/commit/src/dnsproxy.c?h=1.30=0439194ed0c5a90f61dbef86d9a51307764da2d7), but then was refactored in later commits - Vladimir Pavljuchenkov ___ connman mailing list connman@connman.net https://lists.connman.net/mailman/listinfo/connman
Re: searchdns does not work in connman 1.30
On 27.10.2015 15:00, SpiderX wrote: > ~ $ host -v nefrit1 > Trying "nefrit1" > Host nefrit1 not found: 3(NXDOMAIN) > Received 100 bytes from 127.0.0.1#53 in 0 ms > > So, we have two queries to two nameservers. Two of them have returned > NXDomain, and this result was sent back to a client. > I think this behaviour is wrong, client shouldn't get NXDomain when > other non-nxdomain replies from nameservers exist. > > This was fixed once (see commit > http://git.kernel.org/cgit/network/connman/connman.git/commit/src/dnsproxy.c?h=1.30=0439194ed0c5a90f61dbef86d9a51307764da2d7), > but then was refactored in later commits 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. Though, it would be nice if it would work also when the response is not in the cache. I will try to check what broke it.. First try: host -v -t a bz Trying "bz" ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 44260 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;bz.IN A Received 20 bytes from 127.0.0.1#53 in 122 ms Second try: host -v -t a bz Trying "bz" ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 26675 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;bz.IN A ;; ANSWER SECTION: bz. 49 IN A 1.2.3.4 Received 38 bytes from 127.0.0.1#53 in 7 ms Br, Pasi ___ connman mailing list connman@connman.net https://lists.connman.net/mailman/listinfo/connman
