On Mon, Jun 25, 2018 at 4:39 PM, Jason A. Donenfeld <ja...@zx2c4.com> wrote: > Two rules with different values of suppress_prefix or suppress_ifgroup > are not the same. This fixes an -EEXIST when running: > > $ ip -4 rule add table main suppress_prefixlength 0 > > Signed-off-by: Jason A. Donenfeld <ja...@zx2c4.com> > Fixes: f9d4b0c1e969 ("fib_rules: move common handling of newrule delrule msgs > into fib_nl2rule") > --- > This adds the new condition you mentioned. I'm not sure what you make of > DaveM's remark about this not being in the original code, but here is > nonetheless the requested change.
I just saw DaveM's comment and agree the new rule_find is different but that was intentional and it merged the finding of the rule in the newlink and dellink paths. I did port each of the conditions from previous rule_exists to new rule_find, but forgot to add the new keys which now became necessary. I replied with details on your other bug report thread. Also pasting that response here: So the previous rule_exists code did not check for attribute matches correctly. It would ignore a rule at the first non-existent attribute mis-match. And rule_find will always be called with a valid key. eg in your case, it would return at pref mismatch...and never match an existing rule. $ip -4 rule add table main suppress_prefixlength 0 $ip -4 rule add table main suppress_prefixlength 0 $ip -4 rule add table main suppress_prefixlength 0 $ip rule show 0: from all lookup local 32763: from all lookup main suppress_prefixlength 0 32764: from all lookup main suppress_prefixlength 0 32765: from all lookup main suppress_prefixlength 0 32766: from all lookup main 32767: from all lookup default With your patch, you should get proper EXISTS check $ ip -4 rule add table main suppress_prefixlength 0 $ ip -4 rule add table main suppress_prefixlength 0 RTNETLINK answers: File exists Dave, pls let me know if this is acceptable. If not I can easily restore the previous rule_exists func. Will also submit a patch to cover this in self-tests. thanks. > > net/core/fib_rules.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c > index 126ffc5bc630..bc8425d81022 100644 > --- a/net/core/fib_rules.c > +++ b/net/core/fib_rules.c > @@ -416,6 +416,14 @@ static struct fib_rule *rule_find(struct fib_rules_ops > *ops, > if (rule->mark && r->mark != rule->mark) > continue; > > + if (rule->suppress_ifgroup != -1 && > + r->suppress_ifgroup != rule->suppress_ifgroup) > + continue; > + > + if (rule->suppress_prefixlen != -1 && > + r->suppress_prefixlen != rule->suppress_prefixlen) > + continue; > + > if (rule->mark_mask && r->mark_mask != rule->mark_mask) > continue; > > --