cfg80211: return private regdom for self-managed devices

If a device has self-managed regulatory, insist on returning the wiphy
specific regdomain if a wiphy-idx is specified. The global regdomain is
meaningless for such devices.

Also add an attribute for self-managed devices, so usermode can
distinguish them as such.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Reviewed-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

2 files changed, 34 insertions, 0 deletions

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index fb58e654f523..b3ada0b3a276 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -261,6 +261,9 @@
  *      the regulatory core to help with compliance. A dump version of this API
  *      is now available which will returns the global regdomain as well as
  *      all private regdomains of present wiphys (for those that have it).
+ *      If a wiphy is self-managed (%NL80211_ATTR_WIPHY_SELF_MANAGED_REG), then
+ *      its private regdomain is the only valid one for it. The regulatory
+ *      core is not used to help with compliance in this case.
  * @NL80211_CMD_SET_REG: Set current regulatory domain. CRDA sends this command
  *      after being queried by the kernel. CRDA replies by sending a regulatory
  *      domain structure which consists of %NL80211_ATTR_REG_ALPHA set to our
@@ -1702,6 +1705,11 @@ enum nl80211_commands {
  *
  * @NL80211_ATTR_MAC_MASK: MAC address mask
  *
+ * @NL80211_ATTR_WIPHY_SELF_MANAGED_REG: flag attribute indicating this device
+ *      is self-managing its regulatory information and any regulatory domain
+ *      obtained from it is coming from the device's wiphy and not the global
+ *      cfg80211 regdomain.
+ *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
@@ -2059,6 +2067,8 @@ enum nl80211_attrs {
 
         NL80211_ATTR_MAC_MASK,
 
+        NL80211_ATTR_WIPHY_SELF_MANAGED_REG,
+
         /* add attributes here, update the policy in nl80211.c */
 
         __NL80211_ATTR_AFTER_LAST,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index eebb7e422989..5b1907f4c181 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -396,6 +396,7 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
         [NL80211_ATTR_ADMITTED_TIME] = { .type = NLA_U16 },
         [NL80211_ATTR_SMPS_MODE] = { .type = NLA_U8 },
         [NL80211_ATTR_MAC_MASK] = { .len = ETH_ALEN },
+        [NL80211_ATTR_WIPHY_SELF_MANAGED_REG] = { .type = NLA_FLAG },
 };
 
 /* policy for the key attributes */
@@ -1701,6 +1702,10 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev,
                                rdev->wiphy.max_num_csa_counters))
                         goto nla_put_failure;
 
+                if (rdev->wiphy.regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED &&
+                    nla_put_flag(msg, NL80211_ATTR_WIPHY_SELF_MANAGED_REG))
+                        goto nla_put_failure;
+
                 /* done */
                 state->split_start = 0;
                 break;
@@ -5406,6 +5411,8 @@ static int nl80211_get_reg_do(struct sk_buff *skb, struct genl_info *info)
                 goto put_failure;
 
         if (info->attrs[NL80211_ATTR_WIPHY]) {
+                bool self_managed;
+
                 rdev = cfg80211_get_dev_from_info(genl_info_net(info), info);
                 if (IS_ERR(rdev)) {
                         nlmsg_free(msg);
@@ -5413,8 +5420,16 @@ static int nl80211_get_reg_do(struct sk_buff *skb, struct genl_info *info)
                 }
 
                 wiphy = &rdev->wiphy;
+                self_managed = wiphy->regulatory_flags &
+                               REGULATORY_WIPHY_SELF_MANAGED;
                 regdom = get_wiphy_regdom(wiphy);
 
+                /* a self-managed-reg device must have a private regdom */
+                if (WARN_ON(!regdom && self_managed)) {
+                        nlmsg_free(msg);
+                        return -EINVAL;
+                }
+
                 if (regdom &&
                     nla_put_u32(msg, NL80211_ATTR_WIPHY, get_wiphy_idx(wiphy)))
                         goto nla_put_failure;
@@ -5471,6 +5486,10 @@ static int nl80211_send_regdom(struct sk_buff *msg, struct netlink_callback *cb,
             nla_put_u32(msg, NL80211_ATTR_WIPHY, get_wiphy_idx(wiphy)))
                 goto nla_put_failure;
 
+        if (wiphy && wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED &&
+            nla_put_flag(msg, NL80211_ATTR_WIPHY_SELF_MANAGED_REG))
+                goto nla_put_failure;
+
         return genlmsg_end(msg, hdr);
 
 nla_put_failure:
@@ -11076,6 +11095,11 @@ static bool nl80211_reg_change_event_fill(struct sk_buff *msg,
                 if (wiphy &&
                     nla_put_u32(msg, NL80211_ATTR_WIPHY, request->wiphy_idx))
                         goto nla_put_failure;
+
+                if (wiphy &&
+                    wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED &&
+                    nla_put_flag(msg, NL80211_ATTR_WIPHY_SELF_MANAGED_REG))
+                        goto nla_put_failure;
         }
 
         return true;