Fri, Aug 30, 2019 at 04:35:23PM CEST, ro...@cumulusnetworks.com wrote: >On Wed, Aug 28, 2019 at 10:26 PM Michal Kubecek <mkube...@suse.cz> wrote: >> >> On Wed, Aug 28, 2019 at 09:36:41PM -0700, Roopa Prabhu wrote: >> > >> > yes, correct. I mentioned that because I was wondering if we can >> > think along the same lines for this API. >> > eg >> > (a) RTM_NEWLINK always replaces the list attribute >> > (b) RTM_SETLINK with NLM_F_APPEND always appends to the list attribute >> > (c) RTM_DELLINK with NLM_F_APPEND updates the list attribute >> > >> > (It could be NLM_F_UPDATE if NLM_F_APPEND sounds weird in the del >> > case. I have not looked at the full dellink path if it will work >> > neatly..its been a busy day ) >> >> AFAICS rtnl_dellink() calls nlmsg_parse_deprecated() so that even >> current code would ignore any future attribute in RTM_DELLINK message >> (any kernel before the strict validation was introduced definitely will) >> and it does not seem to check NLM_F_APPEND or NLM_F_UPDATE either. So >> unless I missed something, such message would result in deleting the >> network device (if possible) with any kernel not implementing the >> feature. > >ok, ack. yes today it does. I was hinting if that can be changed to >support list update with a flag like the RTM_DELLINK AF_BRIDGE does >for vlan list del. > >so to summarize, i think we have discussed the following options to >update a netlink list attribute so far: >(a) encode an optional attribute/flag in the list attribute in >RTM_SETLINK to indicate if it is a add or del >(b) Use a flag in RTM_SETLINK and RTM_DELINK to indicate add/del >(close to bridge vlan add/del)
Nope, bridge vlan add/del is done according to the cmd, not any flag. >(c) introduce a separate generic msg type to add/del to a list >attribute (IIUC this does need a separate msg type per subsystem or >netlink API)
