ngctl: Check hook name length

[des]

Summary

Check the length of the hook name when copying it into the sockaddr.

MFC after: 1 week

[markj]

usr.sbin/ngctl/write.c

77

Better would be to write sizeof(sag->sg_data) instead of NG_HOOKSIZ IMO.

79

Might as well explain why it's invalid.

[des]

usr.sbin/ngctl/write.c

77

No, because sag->sg_data has the wrong size.

[des]

better error message

[markj]

usr.sbin/ngctl/write.c

77

sag->sg_data is defined as char sg_data[32] and NG_HOOKSIZ is 32 as well. What am I missing?

[des]

usr.sbin/ngctl/write.c

77

That's a recent change which can't be MFCed. It's also a parallel construction: a hardcoded literal which has been chosen to match to the current value of NG_NODESIZ, but deliberately not NG_NODESIZ itself. And last but not least, I don't feel comfortable assuming that NG_HOOKSIZ is equal to NG_NODESIZ.

[markj]

usr.sbin/ngctl/write.c

77

Then you might consider adding something like _Static_assert(NG_HOOKSIZ <= sizeof(sag->sg_data)) or _Static_assert(NG_HOOKSIZ <= sizeof(sagbuf)).