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| author | Pablo Neira <pablo@netfilter.org> | 2013-07-29 12:30:04 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-07-30 16:43:19 -0700 |
| commit | e1ee3673a83cc02b6b5e43c9e647d8dd5e1c4e26 (patch) | |
| tree | b57a7d6e6380fd3aa127eb8bb3b6e67433834c16 | |
| parent | ff862a4668dd6dba962b1d2d8bd344afa6375683 (diff) | |
| download | blackbird-op-linux-e1ee3673a83cc02b6b5e43c9e647d8dd5e1c4e26.tar.gz blackbird-op-linux-e1ee3673a83cc02b6b5e43c9e647d8dd5e1c4e26.zip | |
genetlink: fix usage of NLM_F_EXCL or NLM_F_REPLACE
Currently, it is not possible to use neither NLM_F_EXCL nor
NLM_F_REPLACE from genetlink. This is due to this checking in
genl_family_rcv_msg:
if (nlh->nlmsg_flags & NLM_F_DUMP)
NLM_F_DUMP is NLM_F_MATCH|NLM_F_ROOT. Thus, if NLM_F_EXCL or
NLM_F_REPLACE flag is set, genetlink believes that you're
requesting a dump and it calls the .dumpit callback.
The solution that I propose is to refine this checking to
make it stricter:
if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP)
And given the combination NLM_F_REPLACE and NLM_F_EXCL does
not make sense to me, it removes the ambiguity.
There was a patch that tried to fix this some time ago (0ab03c2
netlink: test for all flags of the NLM_F_DUMP composite) but it
tried to resolve this ambiguity in *all* existing netlink subsystems,
not only genetlink. That patch was reverted since it broke iproute2,
which is using NLM_F_ROOT to request the dump of the routing cache.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/netlink/genetlink.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index 1076fe16b122..512718adb0d5 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -571,7 +571,7 @@ static int genl_family_rcv_msg(struct genl_family *family, !capable(CAP_NET_ADMIN)) return -EPERM; - if (nlh->nlmsg_flags & NLM_F_DUMP) { + if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) { struct netlink_dump_control c = { .dump = ops->dumpit, .done = ops->done, |
