ntp: fix handling of socket errors with error queue

In the next Linux version the recvmmsg() system call will be probably
fixed to not return socket errors (e.g. due to ICMP) when reading from
the error queue.

The NTP I/O code assumed this was the correct behavior. When the system
call is fixed, a socket error on a client socket will cause chronyd to
enter a busy loop consuming the CPU until the receive timeout is reached
(8 seconds by default).

Use getsockopt(SO_ERROR) to clear the socket error when reading from the
error queue failed.
This commit is contained in:
Miroslav Lichvar
2018-04-04 09:07:10 +02:00
parent fd1e80802f
commit 19f3ab2225
2 changed files with 15 additions and 1 deletions

View File

@@ -497,7 +497,7 @@ SYS_Linux_EnableSystemCallFilter(int level)
SCMP_SYS(lseek), SCMP_SYS(rename), SCMP_SYS(stat), SCMP_SYS(stat64),
SCMP_SYS(statfs), SCMP_SYS(statfs64), SCMP_SYS(unlink),
/* Socket */
SCMP_SYS(bind), SCMP_SYS(connect), SCMP_SYS(getsockname),
SCMP_SYS(bind), SCMP_SYS(connect), SCMP_SYS(getsockname), SCMP_SYS(getsockopt),
SCMP_SYS(recvfrom), SCMP_SYS(recvmmsg), SCMP_SYS(recvmsg),
SCMP_SYS(sendmmsg), SCMP_SYS(sendmsg), SCMP_SYS(sendto),
/* TODO: check socketcall arguments */