On Mon, Mar 20, 2017 at 8:50 PM, Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> wrote:
> On Mon, Mar 20, 2017 at 11:44:42AM +0100, Pablo Neira Ayuso wrote:
>> > diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
>> > index 6dc44d9..6c840af 100644
>> > --- a/net/netfilter/nf_conntrack_helper.c
>> > +++ b/net/netfilter/nf_conntrack_helper.c
>> > @@ -130,6 +130,42 @@ static unsigned int helper_hash(const struct nf_conntrack_tuple *tuple)
>> > return NULL;
>> > }
>> >
>> > +static void
>> > +nf_ct_remove_expect_refer_dying_module(const struct module *me)
>> > +{
>> > + struct nf_conntrack_expect *exp;
>> > + const struct hlist_node *next;
>> > + u32 i;
>> > +
>> > + if (!me)
>> > + return;
>> > +
>> > + /* Make sure no one is still using the moudule unless
>> > + * its a connection in the hash.
>> > + */
>> > + synchronize_rcu();
>> > +
>> > + /* Get rid of expectations */
>> > + spin_lock_bh(&nf_conntrack_expect_lock);
>> > + for (i = 0; i < nf_ct_expect_hsize; i++) {
>> > + hlist_for_each_entry_safe(exp, next,
>> > + &nf_ct_expect_hash[i], hnode) {
>> > + struct nf_conn_help *master_help = nfct_help(exp->master);
>> > +
>> > + if ((master_help->helper && master_help->helper->me == me) ||
>> > + (exp->helper && exp->helper->me == me) ||
>> > + exp->expectfn_module == me) {
>
> Are you also sure this is correct?
>
> me can be nf_nat_sip, while exp->helper->me points to
> nf_conntrack_sip.
I don't read the source codes of ctlink command.
But it seems be correct from the kernel codes.
Please look at the function "ctnetlink_create_expect".
if (cda[CTA_EXPECT_HELP_NAME]) {
const char *helpname = nla_data(cda[CTA_EXPECT_HELP_NAME]);
helper = __nf_conntrack_helper_find(helpname, u3,
nf_ct_protonum(ct));
The helper is got by cda[CTA_EXPECT_HELP_NAME].
Then go to the function ctnetlink_alloc_expect,
if (cda[CTA_EXPECT_FN]) {
const char *name = nla_data(cda[CTA_EXPECT_FN]);
struct nf_ct_helper_expectfn *expfn;
expfn = nf_ct_helper_expectfn_find_by_name(name);
The expfn is got by cda[CTA_EXPECT_FN].
So it is possible that the helper and expfn which they belongs to
different modules.
If I was right, it is not good to use one member "nat_module" to save
the module of helper and expfn at the same time.
Regards
Feng
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