On 1/25/23 16:15, Vladislav Odintsov wrote: > Hi, > > I’m a bit confused about linux unix socket files permissions, created by ovs > daemons. > > From source code [0] I see it sets 0770 fchmod on file descriptor prior to > socket bind(), assuming that sock file when creates will inherit FD’s > permissions. So, I expect that after unix socket files created, they have > rwxrwx--- permissions. > > However if running, for instance, ovsdb-server as root, it seems that this > fchmod() call has no effect. Instead default root umask (0022) seems to be > used: > > # ovsdb-server --remote punix:///var/run/openvswitch/ovs.sock > /etc/openvswitch/ovs.db > # ls -l /var/run/openvswitch/ovs.sock > srwxr-x--- 1 root root 0 Jan 25 17:48 /var/run/openvswitch/ovs.sock
The requested mode and umask are both effective. The result is (mode & ~umask). In your case: 0770 & ~0022 = 0750, i.e. rwxr-x--- > > If switch user to non-root (default umask 0002): > > $ ovsdb-server --remote punix://$(pwd)/ovs.sock --unixctl=$(pwd)/ctl.sock > ./ovs.db > $ ls -l ovs.sock > srwxrwx--- 1 vlodintsov vlodintsov 0 Jan 25 17:42 ovs.sock 0770 & ~0002 = 0770 > > If running as root, passing desired user as an argument to ovsdb-server, it > still has the same as just root behaviour: > > # ovsdb-server --remote punix:///var/run/openvswitch/ovs.sock > /etc/openvswitch/ovs.db --user openvswitch:openvswitch > # ls -l /var/run/openvswitch/ovs.sock > srwxr-x--- 1 openvswitch openvswitch 0 Jan 25 17:47 > /var/run/openvswitch/ovs.sock > > > This line of code [0] is quite old (about 8 years), so what am I doing wrong? > Is it possible to make socket writable by group without extenal call chmod > 0770 <path_to_socket> ? Process has inherited umask from the current shell, i.e. the parent process. umask is not a property of a user, it is typically set for a shell session in bashrc or /etc/profile. OVS has no way to know what is the desired umask for the user we're switching to. So, it remains the same as it was. Changing the umask for a current shell before starting the process should help, e.g. (umask 0002 && \ ovsdb-server --remote punix:$(pwd)/ovs.sock /etc/openvswitch/ovs.db \ --user openvswitch:openvswitch) Best regards, Ilya Maximets. > > 0: https://github.com/openvswitch/ovs/blob/v2.17.5/lib/socket-util-unix.c#L264 > > Regards, > Vladislav Odintsov _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev