| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <d9db14adbac97234729b112ebfa87c91@visp.net.lb>
Date: Fri, 12 Sep 2014 21:18:45 +0300
From: Denys Fedoryshchenko <nuclearcat@...learcat.com>
To: netdev@...r.kernel.org
Subject: connect returns EADDRNOTAVAIL on ~600k+ sockets host
Hi
I noticed strange behaviour on loaded server (haproxy), while it is
handling load for https traffic well, tcp monitoring started to give
false alerts. And here what i found:
HTTPS-BALANCER ~ # telnet 127.0.0.1 23
telnet: can't connect to remote host (127.0.0.1): Cannot assign
requested address
HTTPS-BALANCER ~ # nc -v 127.0.0.1 23
127.0.0.1 (127.0.0.1:23) open
��.��.��.��.
HTTPS-BALANCER login: ^Cpunt!
The difference is (relevant lines from strace):
socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 3
setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
bind(3, {sa_family=AF_INET, sin_port=htons(0),
sin_addr=inet_addr("0.0.0.0")}, 16) = 0
rt_sigaction(SIGALRM, {0x41ecfb, [ALRM], SA_RESTORER|SA_RESTART,
0x7f80725bf5b0}, {SIG_DFL, [], 0}, 8) = 0
alarm(0) = 0
connect(3, {sa_family=AF_INET, sin_port=htons(23),
sin_addr=inet_addr("127.0.0.1")}, 16) = 0
rt_sigaction(SIGALRM, {SIG_IGN, [ALRM], SA_RESTORER|SA_RESTART,
0x7f80725bf5b0}, {0x41ecfb, [ALRM], SA_RESTORER|SA_RESTART, 0x7
socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 3
setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
connect(3, {sa_family=AF_INET, sin_port=htons(23),
sin_addr=inet_addr("127.0.0.1")}, 16) = -1 EADDRNOTAVAIL (Cannot assign
requested address)
write(2, "telnet: can't connect to remote host (127.0.0.1): Cannot
assign requested address\n", 82telnet: can't connect to remote host
(127.0.0.1): Cannot assign requested address
So,
bind(3, {sa_family=AF_INET, sin_port=htons(0),
sin_addr=inet_addr("0.0.0.0")}, 16) = 0
is fixing issue, but is it really supposed to be like this?
Just for information host load and some network stats:
from /proc/net/protocols, i removed irrelevant zero values entries
protocol size sockets memory press maxhdr slab module cl co di ac
io in de sh ss gs se re sp bi br ha uh gp em
UDP 816 1 0 NI 0 yes kernel y y y n
y n y n y y y y y n y y y y n
TCP 1640 728255 751777 no 208 yes kernel y y y y
y y y y y y y y y n y y y y y
sockets: used 674375
TCP: inuse 727092 orphan 55119 tw 138533 alloc 729419 mem 745187
UDP: inuse 1 mem 0
UDPLITE: inuse 0
RAW: inuse 0
FRAG: inuse 0 memory 0
0.0.0.0 sockets:
tcp 0 0 0.0.0.0:65530 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:443 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:8880 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:22 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:23 0.0.0.0:*
LISTEN
udp 0 0 0.0.0.0:53073 0.0.0.0:*
127.0.0.1 sockets (this is watchdog, but if i disable, it wont change
anything)
tcp 0 0 127.0.0.1:65530 127.0.0.1:55649
TIME_WAIT
tcp 0 0 127.0.0.1:65530 127.0.0.1:41762
FIN_WAIT2
tcp 0 0 127.0.0.1:65530 127.0.0.1:36863
TIME_WAIT
tcp 0 0 127.0.0.1:65530 127.0.0.1:34533
TIME_WAIT
tcp 0 0 127.0.0.1:65530 127.0.0.1:35262
TIME_WAIT
tcp 0 0 127.0.0.1:65530 127.0.0.1:45872
TIME_WAIT
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists