Messages in this thread | | | Date | Fri, 25 Jun 2021 10:40:31 +0200 | From | Pali Rohár <> | Subject | Re: Issues during assigning addresses on point to point interfaces |
| |
On Thursday 24 June 2021 14:57:41 Nicolas Dichtel wrote: > Le 24/06/2021 à 12:45, Marek Behún a écrit : > > On Sun, 6 Jun 2021 17:10:08 +0200 > > Pali Rohár <pali@kernel.org> wrote: > > > >> Hello! > >> > >> Seems that there is a bug during assigning IP addresses on point to > >> point interfaces. > >> > >> Assigning just one local address works fine: > >> > >> ip address add fe80::6 dev ppp1 --> inet6 fe80::6/128 scope link > >> > >> Assigning both local and remote peer address also works fine: > >> > >> ip address add fe80::7 peer fe80::8 dev ppp1 ---> inet6 fe80::7 > >> peer fe80::8/128 scope link > >> > >> But trying to assign just remote peer address does not work. Moreover > >> "ip address" call does not fail, it returns zero but instead of > >> setting remote peer address, it sets local address: > >> > >> ip address add peer fe80::5 dev ppp1 --> inet6 fe80::5/128 scope > >> link > >> > > > > Adding some other people to Cc in order to get their opinions. > > > > It seems this bug is there from the beginning, from commit > > caeaba79009c2 ("ipv6: add support of peer address") > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=caeaba79009c2 > > > > Maybe some older user-space utilities use IFA_ADDRESS instead of > > IFA_LOCAL, and this was done in order to be compatible with them? > If I remember well, there was an issue in the uAPI. > IFA_LOCAL is supposed to be the address of the interface and IFA_ADDRESS is > supposed to be the endpoint of a point-to-point interface. > However, in case of IPv6, it was not the case. In netlink messages generated by > the kernel, IFA_ADDRESS was used instead of IFA_LOCAL. > The patch tried to keep the backward compatibility and the symmetry between msg > from userland and notification from the kernel.
Hello Nicolas!
See my original email where I put also rtnetlink packets (how strace see them). Seems that there is a bug in handling them (or bug in iproute2) as setting just peer (remote) IPv6 address is ignored: https://lore.kernel.org/netdev/20210606151008.7dwx5ukrlvxt4t3k@pali/
Do you have any idea if this is affected by that "issue in the uAPI"? And what is the way how to fix it?
| |