On Tue, May 3, 2016 at 12:12 PM, Guillaume Nault <g.na...@alphalink.fr> wrote: > On Sun, May 01, 2016 at 09:38:57PM +0800, Wang Shanker wrote: >> static int ppp_open(struct inode *inode, struct file *file) >> { >> /* >> * This could (should?) be enforced by the permissions on /dev/ppp. >> */ >> if (!capable(CAP_NET_ADMIN)) >> return -EPERM; >> return 0; >> } >> ``` >> >> I wonder why CAP_NET_ADMIN is needed here, rather than leaving it to the >> permission of the device node. If there is no need, I suggest that the >> CAP_NET_ADMIN check be removed. >> > If this test was removed here, then it'd have to be added again in the > PPPIOCNEWUNIT ioctl, at the very least, because creating a netdevice > should require CAP_NET_ADMIN. Therefore that wouldn't help for your > case. > I don't know why the test was placed in ppp_open() in the first place, > but changing it now would have side effects on user space. So I'd > rather leave the code as is.
I think the question is whether we really require having CAP_NET_ADMIN in the initial namespace and not just in the current one. Is ppp not network namespace aware? -- Thanks, //richard