mark.c output message to stdout hurts

[gnadelwartz]

I suggest to change the printf in line:

App-Route-Jail/mark.c

Line 53 in 94b955b

printf("mark: setting SO_MARK for fd=%u to %#x\n", sd, mark);

to fprintf:

fprintf(stderr, "mark: setting SO_MARK for fd=%u to %#x\n", sd, mark); 

this will prevent problems when using commands with pipes or when parsing stdout

[gnadelwartz]

btw: thank you this was the only simple AND working solution in combination with OpenVpn I found.

all other shims was not working (to old?), namespace and cgroups are complex, no fallback and modyfing them with OpenVpn on new connection is a mess ...

With this jail you simply change the default route for the used table when OpenVpn is started.