From: <dominic.chambers@glencore.com>
To: <musl@lists.openwall.com>
Subject: RE: Queries with less than `ndots` dots never lead to resolution using the global namespace if the `search` domains don't work
Date: Wed, 15 Mar 2017 17:10:08 +0000 [thread overview]
Message-ID: <1e14e4e5bddc41518ff651e4b841c2b1@CHBARSRV1EXCHP1.ANYACCESS.NET> (raw)
In-Reply-To: <20170315151103.GF1693@brightrain.aerifal.cx>
[-- Attachment #1: Type: text/plain, Size: 2754 bytes --]
HI Rich,
I've attached the results from running the following two commands:
1. ` strace ./gai3a google.com 2> strace_of_google-com.txt`
2. ` strace ./gai3a google.com.default.svc 2> strace_of_google-com-default-svc.txt`
Is this what you were looking for or can I provide something more useful?
Thanks again, Dominic.
-----Original Message-----
From: Rich Felker [mailto:dalias@aerifal.cx] On Behalf Of Rich Felker
Sent: 15 March 2017 16:11
To: musl@lists.openwall.com
Subject: Re: [musl] Queries with less than `ndots` dots never lead to resolution using the global namespace if the `search` domains don't work
On Wed, Mar 15, 2017 at 12:58:02PM +0000, dominic.chambers@glencore.com wrote:
> HI Rich,
>
> Thanks for the prompt response here. Apologies for any confusion I may
> have created, but I think the server is responding with an overall
> `NXDOMAIN` response. This is what I get from running `dig
> google.com.default.svc.cluster.local`:
>
> ```
> ; <<>> DiG 9.10.3-P4-Ubuntu <<>> google.com.default.svc.cluster.local
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 20863 ;; flags:
> qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
>
> ;; QUESTION SECTION:
> ;google.com.default.svc.cluster.local. IN A
>
> ;; AUTHORITY SECTION:
> cluster.local. 60 IN SOA ns.dns.cluster.local. hostmaster
> .cluster.local. 1489579200 28800 7200 604800 60
>
> ;; Query time: 0 msec
> ;; SERVER: 10.43.0.10#53(10.43.0.10)
> ;; WHEN: Wed Mar 15 12:49:14 UTC 2017
> ;; MSG SIZE rcvd: 147
> ```
>
> Although there's less information with nslookup, the response from
> running `nslookup google.com.default.svc.cluster.local` seems even
> more definitive:
>
> ```
> Server: 10.43.0.10
> Address: 10.43.0.10#53
>
> ** server can't find google.com.default.svc.cluster.local: NXDOMAIN
> ```
>
> Maybe I was just reading too much into the output from dig regarding
> exactly what was being returned from the server. Any further thoughts?
Can you send an strace log of an affected lookup with musl's resolver (rather than dig/nslookup which use bind's resolver) for me to look at? Attached is source for a trivial sample utility to perform a lookup.
Rich
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[-- Attachment #2: strace_of_google-com.txt --]
[-- Type: text/plain, Size: 5095 bytes --]
execve("./gai3a", ["./gai3a", "google.com"], [/* 15 vars */]) = 0
arch_prctl(ARCH_SET_FS, 0x7f98bb5b2b48) = 0
set_tid_address(0x7f98bb5b2b80) = 44
mprotect(0x7f98bb5af000, 4096, PROT_READ) = 0
mprotect(0x5591835ef000, 4096, PROT_READ) = 0
open("/etc/hosts", O_RDONLY|O_CLOEXEC) = 3
fcntl(3, F_SETFD, FD_CLOEXEC) = 0
readv(3, [{iov_base="", iov_len=0}, {iov_base="# Kubernetes-managed hosts file."..., iov_len=1024}], 2) = 202
readv(3, [{iov_base="", iov_len=0}, {iov_base="", iov_len=1024}], 2) = 0
close(3) = 0
open("/etc/resolv.conf", O_RDONLY|O_CLOEXEC) = 3
fcntl(3, F_SETFD, FD_CLOEXEC) = 0
readv(3, [{iov_base="", iov_len=0}, {iov_base="search default.svc.cluster.local"..., iov_len=248}], 2) = 218
readv(3, [{iov_base="", iov_len=0}, {iov_base="", iov_len=248}], 2) = 0
close(3) = 0
socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_IP) = 3
bind(3, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
sendto(3, "\271\377\1\0\0\1\0\0\0\0\0\0\6google\3com\7default\3"..., 54, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 54
sendto(3, "\341\262\1\0\0\1\0\0\0\0\0\0\6google\3com\7default\3"..., 54, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 54
poll([{fd=3, events=POLLIN}], 1, 2500) = 1 ([{fd=3, revents=POLLIN}])
recvfrom(3, "\271\377\201\203\0\1\0\0\0\1\0\0\6google\3com\7default\3"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 147
recvfrom(3, "\341\262\201\203\0\1\0\0\0\1\0\0\6google\3com\7default\3"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 147
close(3) = 0
socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_IP) = 3
bind(3, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
sendto(3, "\376\300\1\0\0\1\0\0\0\0\0\0\6google\3com\3svc\7clus"..., 46, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 46
sendto(3, "\2.\1\0\0\1\0\0\0\0\0\0\6google\3com\3svc\7clus"..., 46, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 46
poll([{fd=3, events=POLLIN}], 1, 2500) = 1 ([{fd=3, revents=POLLIN}])
recvfrom(3, "\376\300\201\203\0\1\0\0\0\1\0\0\6google\3com\3svc\7clus"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 139
recvfrom(3, "\2.\201\203\0\1\0\0\0\1\0\0\6google\3com\3svc\7clus"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 139
close(3) = 0
socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_IP) = 3
bind(3, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
sendto(3, "\7\340\1\0\0\1\0\0\0\0\0\0\6google\3com\7cluster\5"..., 42, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 42
sendto(3, "\n\346\1\0\0\1\0\0\0\0\0\0\6google\3com\7cluster\5"..., 42, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 42
poll([{fd=3, events=POLLIN}], 1, 2500) = 1 ([{fd=3, revents=POLLIN}])
recvfrom(3, "\7\340\201\203\0\1\0\0\0\1\0\0\6google\3com\7cluster\5"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 135
recvfrom(3, "\n\346\201\203\0\1\0\0\0\1\0\0\6google\3com\7cluster\5"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 135
close(3) = 0
socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_IP) = 3
bind(3, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
sendto(3, "H\244\1\0\0\1\0\0\0\0\0\0\6google\3com\7kubelet\n"..., 64, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 64
sendto(3, "K\266\1\0\0\1\0\0\0\0\0\0\6google\3com\7kubelet\n"..., 64, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 64
poll([{fd=3, events=POLLIN}], 1, 2500) = 1 ([{fd=3, revents=POLLIN}])
recvfrom(3, "H\244\205\200\0\1\0\0\0\1\0\0\6google\3com\7kubelet\n"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 100
recvfrom(3, 0x7fff9c3f83c0, 512, 0, 0x7fff9c3f7e70, [16]) = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}], 1, 2498) = 1 ([{fd=3, revents=POLLIN}])
recvfrom(3, "K\266\205\200\0\1\0\0\0\1\0\0\6google\3com\7kubelet\n"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 100
close(3) = 0
ioctl(1, TIOCGWINSZ, {ws_row=0, ws_col=0, ws_xpixel=0, ws_ypixel=0}) = 0
writev(1, [{iov_base="google.com: Name does not resolv"..., iov_len=33}, {iov_base="\n", iov_len=1}], 2) = 34
exit_group(0) = ?
+++ exited with 0 +++
[-- Attachment #3: strace_of_google-com-default-svc.txt --]
[-- Type: text/plain, Size: 5081 bytes --]
execve("./gai3a", ["./gai3a", "google.com.default.svc"], [/* 15 vars */]) = 0
arch_prctl(ARCH_SET_FS, 0x7f0198178b48) = 0
set_tid_address(0x7f0198178b80) = 48
mprotect(0x7f0198175000, 4096, PROT_READ) = 0
mprotect(0x55a2dfb68000, 4096, PROT_READ) = 0
open("/etc/hosts", O_RDONLY|O_CLOEXEC) = 3
fcntl(3, F_SETFD, FD_CLOEXEC) = 0
readv(3, [{iov_base="", iov_len=0}, {iov_base="# Kubernetes-managed hosts file."..., iov_len=1024}], 2) = 202
readv(3, [{iov_base="", iov_len=0}, {iov_base="", iov_len=1024}], 2) = 0
close(3) = 0
open("/etc/resolv.conf", O_RDONLY|O_CLOEXEC) = 3
fcntl(3, F_SETFD, FD_CLOEXEC) = 0
readv(3, [{iov_base="", iov_len=0}, {iov_base="search default.svc.cluster.local"..., iov_len=248}], 2) = 218
readv(3, [{iov_base="", iov_len=0}, {iov_base="", iov_len=248}], 2) = 0
close(3) = 0
socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_IP) = 3
bind(3, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
sendto(3, "\4\24\1\0\0\1\0\0\0\0\0\0\6google\3com\7default\3"..., 66, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 66
sendto(3, "\tI\1\0\0\1\0\0\0\0\0\0\6google\3com\7default\3"..., 66, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 66
poll([{fd=3, events=POLLIN}], 1, 2500) = 1 ([{fd=3, revents=POLLIN}])
recvfrom(3, "\4\24\201\203\0\1\0\0\0\1\0\0\6google\3com\7default\3"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 159
recvfrom(3, "\tI\201\203\0\1\0\0\0\1\0\0\6google\3com\7default\3"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 159
close(3) = 0
socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_IP) = 3
bind(3, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
sendto(3, "0f\1\0\0\1\0\0\0\0\0\0\6google\3com\7default\3"..., 58, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 58
sendto(3, "3\310\1\0\0\1\0\0\0\0\0\0\6google\3com\7default\3"..., 58, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 58
poll([{fd=3, events=POLLIN}], 1, 2500) = 1 ([{fd=3, revents=POLLIN}])
recvfrom(3, "0f\201\203\0\1\0\0\0\1\0\0\6google\3com\7default\3"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 151
recvfrom(3, "3\310\201\203\0\1\0\0\0\1\0\0\6google\3com\7default\3"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 151
close(3) = 0
socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_IP) = 3
bind(3, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
sendto(3, "m\25\1\0\0\1\0\0\0\0\0\0\6google\3com\7default\3"..., 54, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 54
sendto(3, "pc\1\0\0\1\0\0\0\0\0\0\6google\3com\7default\3"..., 54, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 54
poll([{fd=3, events=POLLIN}], 1, 2500) = 1 ([{fd=3, revents=POLLIN}])
recvfrom(3, "m\25\201\203\0\1\0\0\0\1\0\0\6google\3com\7default\3"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 147
recvfrom(3, "pc\201\203\0\1\0\0\0\1\0\0\6google\3com\7default\3"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 147
close(3) = 0
socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_IP) = 3
bind(3, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
sendto(3, "\311\20\1\0\0\1\0\0\0\0\0\0\6google\3com\7default\3"..., 76, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 76
sendto(3, "\314\262\1\0\0\1\0\0\0\0\0\0\6google\3com\7default\3"..., 76, MSG_NOSIGNAL, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, 16) = 76
poll([{fd=3, events=POLLIN}], 1, 2500) = 1 ([{fd=3, revents=POLLIN}])
recvfrom(3, "\311\20\205\200\0\1\0\0\0\1\0\0\6google\3com\7default\3"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 112
recvfrom(3, 0x7ffd858042e0, 512, 0, 0x7ffd85803d90, [16]) = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}], 1, 2498) = 1 ([{fd=3, revents=POLLIN}])
recvfrom(3, "\314\262\205\200\0\1\0\0\0\1\0\0\6google\3com\7default\3"..., 512, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.43.0.10")}, [16]) = 112
close(3) = 0
ioctl(1, TIOCGWINSZ, {ws_row=0, ws_col=0, ws_xpixel=0, ws_ypixel=0}) = 0
writev(1, [{iov_base="google.com.default.svc: Name doe"..., iov_len=45}, {iov_base="\n", iov_len=1}], 2) = 46
exit_group(0) = ?
+++ exited with 0 +++
next prev parent reply other threads:[~2017-03-15 17:10 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-15 10:28 dominic.chambers
2017-03-15 12:25 ` Rich Felker
2017-03-15 12:58 ` dominic.chambers
2017-03-15 15:11 ` Rich Felker
2017-03-15 16:58 ` dominic.chambers
2017-03-15 17:10 ` dominic.chambers [this message]
2017-03-15 17:22 ` Rich Felker
2017-03-15 19:26 ` dominic.chambers
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