On 9/2/2022 10:12 PM, Johannes Berg wrote:
From: Johannes Berg <johannes.berg@xxxxxxxxx>
Implement an API function and debugfs file to switch
active links.
Also provide an async version of the API so drivers
can call it in arbitrary contexts, e.g. while in the
authorized callback.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
include/net/mac80211.h | 41 ++++++++
net/mac80211/debugfs_netdev.c | 26 ++++++
net/mac80211/ieee80211_i.h | 4 +
net/mac80211/iface.c | 12 +++
net/mac80211/key.c | 34 +++++++
net/mac80211/key.h | 3 +
net/mac80211/link.c | 171 ++++++++++++++++++++++++++++++++++
7 files changed, 291 insertions(+)
...
+static int _ieee80211_set_active_links(struct ieee80211_sub_if_data *sdata,
+ u16 active_links)
+{
+ struct ieee80211_bss_conf *link_confs[IEEE80211_MLD_MAX_NUM_LINKS];
+ struct ieee80211_local *local = sdata->local;
+ u16 old_active = sdata->vif.active_links;
+ unsigned long rem = old_active & ~active_links;
+ unsigned long add = active_links & ~old_active;
+ struct sta_info *sta;
+ unsigned int link_id;
+ int ret, i;
+
+ if (!ieee80211_sdata_running(sdata))
+ return -ENETDOWN;
+
+ if (sdata->vif.type != NL80211_IFTYPE_STATION)
+ return -EINVAL;
+
+ /* cannot activate links that don't exist */
+ if (active_links & ~sdata->vif.valid_links)
+ return -EINVAL;
+
+ /* nothing to do */
+ if (old_active == active_links)
+ return 0;
+
+ for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++)
+ link_confs[i] = sdata_dereference(sdata->vif.link_conf[i],
+ sdata);
+
+ if (add) {
+ sdata->vif.active_links |= active_links;
+ ret = drv_change_vif_links(local, sdata,
+ old_active,
+ sdata->vif.active_links,
+ link_confs);
+ if (ret) {
+ sdata->vif.active_links = old_active;
+ return ret;
+ }
+ }
+
+ for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
+ struct ieee80211_link_data *link;
+
+ link = sdata_dereference(sdata->link[link_id], sdata);
+
+ /* FIXME: kill TDLS connections on the link */
+
+ ieee80211_link_release_channel(link);
+ }
+
+ list_for_each_entry(sta, &local->sta_list, list) {
+ if (sdata != sta->sdata)
+ continue;
+ ret = drv_change_sta_links(local, sdata, &sta->sta,
+ old_active,
+ old_active | active_links);
+ WARN_ON_ONCE(ret);
+ }
+
+ ret = ieee80211_key_switch_links(sdata, rem, add);
I see ieee80211_key_switch_link() only handler the per-link(link_id >=
0) keys,
So I think lower driver also install the pairwise keys(link_id = -1) for
the added links at this moment?
+ WARN_ON_ONCE(ret);
+
+ list_for_each_entry(sta, &local->sta_list, list) {
+ if (sdata != sta->sdata)
+ continue;
+ ret = drv_change_sta_links(local, sdata, &sta->sta,
+ old_active | active_links,
+ active_links);
+ WARN_ON_ONCE(ret);
+ }
+
I see 2 times to call drv_change_sta_link() above, and with sequence
old_active->old_active | active_links->active_links
May I know is it has some design here?
+ for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
+ struct ieee80211_link_data *link;
+
+ link = sdata_dereference(sdata->link[link_id], sdata);
+
+ ret = ieee80211_link_use_channel(link, &link->conf->chandef,
+ IEEE80211_CHANCTX_SHARED);
For the 1st link of MLO connection/NON-MLO connetion, ieee80211_link_use_channel() is called before drv_change_sta_link(),
And now it is after drv_change_sta_link(), May I know is it also has some design here?
Also I see commit(8fb7e2ef4bab mac80211_hwsim: always activate all links) and ieee80211_if_parse_active_links()
will use ieee80211_set_active_links(), so I think ieee80211_set_active_links() has passed test case with some type lower driver/chip?
+ WARN_ON_ONCE(ret);
+
+ ieee80211_link_info_change_notify(sdata, link,
+ BSS_CHANGED_ERP_CTS_PROT |
+ BSS_CHANGED_ERP_PREAMBLE |
+ BSS_CHANGED_ERP_SLOT |
+ BSS_CHANGED_HT |
+ BSS_CHANGED_BASIC_RATES |
+ BSS_CHANGED_BSSID |
+ BSS_CHANGED_CQM |
+ BSS_CHANGED_QOS |
+ BSS_CHANGED_TXPOWER |
+ BSS_CHANGED_BANDWIDTH |
+ BSS_CHANGED_TWT |
+ BSS_CHANGED_HE_OBSS_PD |
+ BSS_CHANGED_HE_BSS_COLOR);
+ ieee80211_mgd_set_link_qos_params(link);
+ }
+
+ old_active = sdata->vif.active_links;
+ sdata->vif.active_links = active_links;
+
+ if (rem) {
+ ret = drv_change_vif_links(local, sdata, old_active,
+ active_links, link_confs);
+ WARN_ON_ONCE(ret);
+ }
+
+ return 0;
+}
+
...
