On Fri, 2022-12-09 at 16:28 +0100, Alvin Šipraga wrote:
>
> This is problematic because it is possible that the network
> configuration that should be applied is a function of the AP's
> properties such as SSID (cf. SSID= in systemd.network(5)). As
> illustrated in the above diagram, it may be that the AP with SSID "bar"
> ends up being configured as though it had SSID "foo".
>
You might not care if you want the SSID, but it still seems wrong:
> +static void nl80211_send_ap_started(struct wireless_dev *wdev)
> +{
> + struct wiphy *wiphy = wdev->wiphy;
> + struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
> + struct sk_buff *msg;
> + void *hdr;
> +
> + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
> + if (!msg)
> + return;
> +
> + hdr = nl80211hdr_put(msg, 0, 0, 0, NL80211_CMD_START_AP);
> + if (!hdr)
> + goto out;
> +
> + if (nla_put_u32(msg, NL80211_ATTR_WIPHY, rdev->wiphy_idx) ||
> + nla_put_u32(msg, NL80211_ATTR_IFINDEX, wdev->netdev->ifindex) ||
> + nla_put_u64_64bit(msg, NL80211_ATTR_WDEV, wdev_id(wdev),
> + NL80211_ATTR_PAD) ||
> + (wdev->u.ap.ssid_len &&
> + nla_put(msg, NL80211_ATTR_SSID, wdev->u.ap.ssid_len,
> + wdev->u.ap.ssid)))
> + goto out;
> +
> + genlmsg_end(msg, hdr);
> +
> + genlmsg_multicast_netns(&nl80211_fam, wiphy_net(wiphy), msg, 0,
> + NL80211_MCGRP_MLME, GFP_KERNEL);
> + return;
> +out:
> + nlmsg_free(msg);
> +}
This has no indication of the link, but with multi-link you could
actually be sending this event multiple times to userspace on the same
netdev.
> static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
> {
> struct cfg80211_registered_device *rdev = info->user_ptr[0];
> @@ -6050,6 +6083,8 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
>
> if (info->attrs[NL80211_ATTR_SOCKET_OWNER])
> wdev->conn_owner_nlportid = info->snd_portid;
> +
> + nl80211_send_ap_started(wdev);
> }
because this can be called multiple times, once for each link.
Seems like you should include the link ID or something?
johannes
