cfg80211: do not replace BSS structs

Instead, allocate extra IE memory if necessary. Normally,
this isn't even necessary since there's enough space.

This is a better way of correcting the "held BSS can
disappear" issue, but also a lot more code. It is also
necessary for proper auth/assoc BSS handling in the
future.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg 2009-04-16 15:00:58 +02:00 committed by John W. Linville
parent 160002fe84
commit cd1658f592
2 changed files with 34 additions and 10 deletions

View file

@ -90,7 +90,7 @@ struct cfg80211_internal_bss {
struct rb_node rbn;
unsigned long ts;
struct kref ref;
bool hold;
bool hold, ies_allocated;
/* must be last because of priv member */
struct cfg80211_bss pub;

View file

@ -58,6 +58,10 @@ static void bss_release(struct kref *ref)
bss = container_of(ref, struct cfg80211_internal_bss, ref);
if (bss->pub.free_priv)
bss->pub.free_priv(&bss->pub);
if (bss->ies_allocated)
kfree(bss->pub.information_elements);
kfree(bss);
}
@ -360,21 +364,41 @@ cfg80211_bss_update(struct cfg80211_registered_device *dev,
found = rb_find_bss(dev, res);
if (found && overwrite) {
list_replace(&found->list, &res->list);
rb_replace_node(&found->rbn, &res->rbn,
&dev->bss_tree);
/* XXX: workaround */
res->hold = found->hold;
kref_put(&found->ref, bss_release);
found = res;
} else if (found) {
if (found) {
kref_get(&found->ref);
found->pub.beacon_interval = res->pub.beacon_interval;
found->pub.tsf = res->pub.tsf;
found->pub.signal = res->pub.signal;
found->pub.capability = res->pub.capability;
found->ts = res->ts;
/* overwrite IEs */
if (overwrite) {
size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
size_t ielen = res->pub.len_information_elements;
if (ksize(found) >= used + ielen) {
memcpy(found->pub.information_elements,
res->pub.information_elements, ielen);
found->pub.len_information_elements = ielen;
} else {
u8 *ies = found->pub.information_elements;
if (found->ies_allocated) {
if (ksize(ies) < ielen)
ies = krealloc(ies, ielen,
GFP_ATOMIC);
} else
ies = kmalloc(ielen, GFP_ATOMIC);
if (ies) {
memcpy(ies, res->pub.information_elements, ielen);
found->ies_allocated = true;
found->pub.information_elements = ies;
}
}
}
kref_put(&res->ref, bss_release);
} else {
/* this "consumes" the reference */