Re: [PATCH 1/3] tests/vm: Set UseDNS=no in the sshd configuration
On 25/01/2024 20.48, Ilya Leoshkevich wrote:
make vm-build-freebsd sometimes fails with "Connection timed out during
banner exchange". The client strace shows:
13:59:30 write(3, "SSH-2.0-OpenSSH_9.3\r\n", 21) = 21
13:59:30 getpid() = 252655
13:59:30 poll([{fd=3, events=POLLIN}], 1, 5000) = 1 ([{fd=3,
revents=POLLIN}])
13:59:32 read(3, "S", 1)= 1
13:59:32 poll([{fd=3, events=POLLIN}], 1, 3625) = 1 ([{fd=3,
revents=POLLIN}])
13:59:32 read(3, "S", 1)= 1
13:59:32 poll([{fd=3, events=POLLIN}], 1, 3625) = 1 ([{fd=3,
revents=POLLIN}])
13:59:32 read(3, "H", 1)= 1
There is a 2s delay during connection, and ConnectTimeout is set to 1.
Raising it makes the issue go away, but we can do better. The server
truss shows:
888: 27.811414714 socket(PF_INET,SOCK_DGRAM|SOCK_CLOEXEC,0) = 5 (0x5)
888: 27.811765030 connect(5,{ AF_INET 10.0.2.3:53 },16) = 0 (0x0)
888: 27.812166941
sendto(5,"\^Z/\^A\0\0\^A\0\0\0\0\0\0\^A2"...,39,0,NULL,0) = 39 (0x27)
888: 29.363970743 poll({ 5/POLLRDNORM },1,5000) = 1 (0x1)
So the delay is due to a DNS query. Disable DNS queries in the server
config.
Signed-off-by: Ilya Leoshkevich
---
tests/vm/basevm.py | 2 ++
1 file changed, 2 insertions(+)
diff --git a/tests/vm/basevm.py b/tests/vm/basevm.py
index 61725b83254..c0d62c08031 100644
--- a/tests/vm/basevm.py
+++ b/tests/vm/basevm.py
@@ -423,6 +423,8 @@ def console_ssh_init(self, prompt, user, pw):
def console_sshd_config(self, prompt):
self.console_wait(prompt)
self.console_send("echo 'PermitRootLogin yes' >>
/etc/ssh/sshd_config\n")
+self.console_wait(prompt)
+self.console_send("echo 'UseDNS no' >> /etc/ssh/sshd_config\n")
for var in self.envvars:
self.console_wait(prompt)
self.console_send("echo 'AcceptEnv %s' >> /etc/ssh/sshd_config\n"
% var)
Reviewed-by: Thomas Huth
[PATCH 1/3] tests/vm: Set UseDNS=no in the sshd configuration
make vm-build-freebsd sometimes fails with "Connection timed out during
banner exchange". The client strace shows:
13:59:30 write(3, "SSH-2.0-OpenSSH_9.3\r\n", 21) = 21
13:59:30 getpid() = 252655
13:59:30 poll([{fd=3, events=POLLIN}], 1, 5000) = 1 ([{fd=3,
revents=POLLIN}])
13:59:32 read(3, "S", 1)= 1
13:59:32 poll([{fd=3, events=POLLIN}], 1, 3625) = 1 ([{fd=3,
revents=POLLIN}])
13:59:32 read(3, "S", 1)= 1
13:59:32 poll([{fd=3, events=POLLIN}], 1, 3625) = 1 ([{fd=3,
revents=POLLIN}])
13:59:32 read(3, "H", 1)= 1
There is a 2s delay during connection, and ConnectTimeout is set to 1.
Raising it makes the issue go away, but we can do better. The server
truss shows:
888: 27.811414714 socket(PF_INET,SOCK_DGRAM|SOCK_CLOEXEC,0) = 5 (0x5)
888: 27.811765030 connect(5,{ AF_INET 10.0.2.3:53 },16) = 0 (0x0)
888: 27.812166941 sendto(5,"\^Z/\^A\0\0\^A\0\0\0\0\0\0\^A2"...,39,0,NULL,0)
= 39 (0x27)
888: 29.363970743 poll({ 5/POLLRDNORM },1,5000) = 1 (0x1)
So the delay is due to a DNS query. Disable DNS queries in the server
config.
Signed-off-by: Ilya Leoshkevich
---
tests/vm/basevm.py | 2 ++
1 file changed, 2 insertions(+)
diff --git a/tests/vm/basevm.py b/tests/vm/basevm.py
index 61725b83254..c0d62c08031 100644
--- a/tests/vm/basevm.py
+++ b/tests/vm/basevm.py
@@ -423,6 +423,8 @@ def console_ssh_init(self, prompt, user, pw):
def console_sshd_config(self, prompt):
self.console_wait(prompt)
self.console_send("echo 'PermitRootLogin yes' >>
/etc/ssh/sshd_config\n")
+self.console_wait(prompt)
+self.console_send("echo 'UseDNS no' >> /etc/ssh/sshd_config\n")
for var in self.envvars:
self.console_wait(prompt)
self.console_send("echo 'AcceptEnv %s' >> /etc/ssh/sshd_config\n"
% var)
--
2.43.0
