cfg80211: allow usermode to query wiphy specific regdom

If a wiphy-idx is specified, the kernel will return the wiphy specific
regdomain, if such exists. Otherwise return the global regdom.

When no wiphy-idx is specified, return the global regdomain as well as
all wiphy-specific regulatory domains in the system, via a new nested
list of attributes.

Add a new attribute for each wiphy-specific regdomain, for usermode to
identify it as such.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index b37bd5a1cb8253cd334ea05c3da920f0cf30f6e0..2d384d0412248df1a0f849a1cdb6755db3ba1b82 100644 (file)
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -252,7 +252,15 @@
  *     %NL80211_ATTR_IFINDEX.
  *
  * @NL80211_CMD_GET_REG: ask the wireless core to send us its currently set
- *     regulatory domain.
+ *     regulatory domain. If %NL80211_ATTR_WIPHY is specified and the device
+ *     has a private regulatory domain, it will be returned. Otherwise, the
+ *     global regdomain will be returned.
+ *     A device will have a private regulatory domain if it uses the
+ *     regulatory_hint() API. Even when a private regdomain is used the channel
+ *     information will still be mended according to further hints from
+ *     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).
  * @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

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index a17d6bc6b22ca7ccda9716af9a3367b66bc47632..2d5dc428c5ab42e8a62f1fcf73964fe23e943c87 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -5327,42 +5327,20 @@ static int nl80211_update_mesh_config(struct sk_buff *skb,
        return err;
 }
 
-static int nl80211_get_reg(struct sk_buff *skb, struct genl_info *info)
+static int nl80211_put_regdom(const struct ieee80211_regdomain *regdom,
+                             struct sk_buff *msg)
 {
-       const struct ieee80211_regdomain *regdom;
-       struct sk_buff *msg;
-       void *hdr = NULL;
        struct nlattr *nl_reg_rules;
        unsigned int i;
 
-       if (!cfg80211_regdomain)
-               return -EINVAL;
-
-       msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
-       if (!msg)
-               return -ENOBUFS;
-
-       hdr = nl80211hdr_put(msg, info->snd_portid, info->snd_seq, 0,
-                            NL80211_CMD_GET_REG);
-       if (!hdr)
-               goto put_failure;
-
-       if (reg_last_request_cell_base() &&
-           nla_put_u32(msg, NL80211_ATTR_USER_REG_HINT_TYPE,
-                       NL80211_USER_REG_HINT_CELL_BASE))
-               goto nla_put_failure;
-
-       rcu_read_lock();
-       regdom = rcu_dereference(cfg80211_regdomain);
-
        if (nla_put_string(msg, NL80211_ATTR_REG_ALPHA2, regdom->alpha2) ||
            (regdom->dfs_region &&
             nla_put_u8(msg, NL80211_ATTR_DFS_REGION, regdom->dfs_region)))
-               goto nla_put_failure_rcu;
+               goto nla_put_failure;
 
        nl_reg_rules = nla_nest_start(msg, NL80211_ATTR_REG_RULES);
        if (!nl_reg_rules)
-               goto nla_put_failure_rcu;
+               goto nla_put_failure;
 
        for (i = 0; i < regdom->n_reg_rules; i++) {
                struct nlattr *nl_reg_rule;
@@ -5377,7 +5355,7 @@ static int nl80211_get_reg(struct sk_buff *skb, struct genl_info *info)
 
                nl_reg_rule = nla_nest_start(msg, i);
                if (!nl_reg_rule)
-                       goto nla_put_failure_rcu;
+                       goto nla_put_failure;
 
                max_bandwidth_khz = freq_range->max_bandwidth_khz;
                if (!max_bandwidth_khz)
@@ -5398,13 +5376,64 @@ static int nl80211_get_reg(struct sk_buff *skb, struct genl_info *info)
                                power_rule->max_eirp) ||
                    nla_put_u32(msg, NL80211_ATTR_DFS_CAC_TIME,
                                reg_rule->dfs_cac_ms))
-                       goto nla_put_failure_rcu;
+                       goto nla_put_failure;
 
                nla_nest_end(msg, nl_reg_rule);
        }
-       rcu_read_unlock();
 
        nla_nest_end(msg, nl_reg_rules);
+       return 0;
+
+nla_put_failure:
+       return -EMSGSIZE;
+}
+
+static int nl80211_get_reg_do(struct sk_buff *skb, struct genl_info *info)
+{
+       const struct ieee80211_regdomain *regdom = NULL;
+       struct cfg80211_registered_device *rdev;
+       struct wiphy *wiphy = NULL;
+       struct sk_buff *msg;
+       void *hdr;
+
+       msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+       if (!msg)
+               return -ENOBUFS;
+
+       hdr = nl80211hdr_put(msg, info->snd_portid, info->snd_seq, 0,
+                            NL80211_CMD_GET_REG);
+       if (!hdr)
+               goto put_failure;
+
+       if (info->attrs[NL80211_ATTR_WIPHY]) {
+               rdev = cfg80211_get_dev_from_info(genl_info_net(info), info);
+               if (IS_ERR(rdev)) {
+                       nlmsg_free(msg);
+                       return PTR_ERR(rdev);
+               }
+
+               wiphy = &rdev->wiphy;
+               regdom = get_wiphy_regdom(wiphy);
+
+               if (regdom &&
+                   nla_put_u32(msg, NL80211_ATTR_WIPHY, get_wiphy_idx(wiphy)))
+                       goto nla_put_failure;
+       }
+
+       if (!wiphy && reg_last_request_cell_base() &&
+           nla_put_u32(msg, NL80211_ATTR_USER_REG_HINT_TYPE,
+                       NL80211_USER_REG_HINT_CELL_BASE))
+               goto nla_put_failure;
+
+       rcu_read_lock();
+
+       if (!regdom)
+               regdom = rcu_dereference(cfg80211_regdomain);
+
+       if (nl80211_put_regdom(regdom, msg))
+               goto nla_put_failure_rcu;
+
+       rcu_read_unlock();
 
        genlmsg_end(msg, hdr);
        return genlmsg_reply(msg, info);
@@ -5418,6 +5447,79 @@ put_failure:
        return -EMSGSIZE;
 }
 
+static int nl80211_send_regdom(struct sk_buff *msg, struct netlink_callback *cb,
+                              u32 seq, int flags, struct wiphy *wiphy,
+                              const struct ieee80211_regdomain *regdom)
+{
+       void *hdr = nl80211hdr_put(msg, NETLINK_CB(cb->skb).portid, seq, flags,
+                                  NL80211_CMD_GET_REG);
+
+       if (!hdr)
+               return -1;
+
+       genl_dump_check_consistent(cb, hdr, &nl80211_fam);
+
+       if (nl80211_put_regdom(regdom, msg))
+               goto nla_put_failure;
+
+       if (!wiphy && reg_last_request_cell_base() &&
+           nla_put_u32(msg, NL80211_ATTR_USER_REG_HINT_TYPE,
+                       NL80211_USER_REG_HINT_CELL_BASE))
+               goto nla_put_failure;
+
+       if (wiphy &&
+           nla_put_u32(msg, NL80211_ATTR_WIPHY, get_wiphy_idx(wiphy)))
+               goto nla_put_failure;
+
+       return genlmsg_end(msg, hdr);
+
+nla_put_failure:
+       genlmsg_cancel(msg, hdr);
+       return -EMSGSIZE;
+}
+
+static int nl80211_get_reg_dump(struct sk_buff *skb,
+                               struct netlink_callback *cb)
+{
+       const struct ieee80211_regdomain *regdom = NULL;
+       struct cfg80211_registered_device *rdev;
+       int err, reg_idx, start = cb->args[2];
+
+       rtnl_lock();
+
+       if (cfg80211_regdomain && start == 0) {
+               err = nl80211_send_regdom(skb, cb, cb->nlh->nlmsg_seq,
+                                         NLM_F_MULTI, NULL,
+                                         rtnl_dereference(cfg80211_regdomain));
+               if (err < 0)
+                       goto out_err;
+       }
+
+       /* the global regdom is idx 0 */
+       reg_idx = 1;
+       list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+               regdom = get_wiphy_regdom(&rdev->wiphy);
+               if (!regdom)
+                       continue;
+
+               if (++reg_idx <= start)
+                       continue;
+
+               err = nl80211_send_regdom(skb, cb, cb->nlh->nlmsg_seq,
+                                         NLM_F_MULTI, &rdev->wiphy, regdom);
+               if (err < 0) {
+                       reg_idx--;
+                       break;
+               }
+       }
+
+       cb->args[2] = reg_idx;
+       err = skb->len;
+out_err:
+       rtnl_unlock();
+       return err;
+}
+
 static int nl80211_set_reg(struct sk_buff *skb, struct genl_info *info)
 {
        struct nlattr *tb[NL80211_REG_RULE_ATTR_MAX + 1];
@@ -10225,7 +10327,8 @@ static const struct genl_ops nl80211_ops[] = {
        },
        {
                .cmd = NL80211_CMD_GET_REG,
-               .doit = nl80211_get_reg,
+               .doit = nl80211_get_reg_do,
+               .dumpit = nl80211_get_reg_dump,
                .policy = nl80211_policy,
                .internal_flags = NL80211_FLAG_NEED_RTNL,
                /* can be retrieved by unprivileged users */
@@ -10983,9 +11086,13 @@ void nl80211_send_reg_change_event(struct regulatory_request *request)
                        goto nla_put_failure;
        }
 
-       if (request->wiphy_idx != WIPHY_IDX_INVALID &&
-           nla_put_u32(msg, NL80211_ATTR_WIPHY, request->wiphy_idx))
-               goto nla_put_failure;
+       if (request->wiphy_idx != WIPHY_IDX_INVALID) {
+               struct wiphy *wiphy = wiphy_idx_to_wiphy(request->wiphy_idx);
+
+               if (wiphy &&
+                   nla_put_u32(msg, NL80211_ATTR_WIPHY, request->wiphy_idx))
+                       goto nla_put_failure;
+       }
 
        genlmsg_end(msg, hdr);
 

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index d83480b6efde165be88c65d51edadf9f7b950908..2d9760084b7479cbfd12831b42dce0e2a518cba7 100644 (file)
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -142,7 +142,7 @@ static const struct ieee80211_regdomain *get_cfg80211_regdom(void)
        return rtnl_dereference(cfg80211_regdomain);
 }
 
-static const struct ieee80211_regdomain *get_wiphy_regdom(struct wiphy *wiphy)
+const struct ieee80211_regdomain *get_wiphy_regdom(struct wiphy *wiphy)
 {
        return rtnl_dereference(wiphy->regd);
 }

diff --git a/net/wireless/reg.h b/net/wireless/reg.h
index 5e48031ccb9afc33a41c36221e3bef924625ebe8..4b45d6e61d24ad71ca2fe0074922ecb1e4a3a1b3 100644 (file)
--- a/net/wireless/reg.h
+++ b/net/wireless/reg.h
@@ -38,6 +38,7 @@ unsigned int reg_get_max_bandwidth(const struct ieee80211_regdomain *rd,
                                   const struct ieee80211_reg_rule *rule);
 
 bool reg_last_request_cell_base(void);
+const struct ieee80211_regdomain *get_wiphy_regdom(struct wiphy *wiphy);
 
 /**
  * regulatory_hint_found_beacon - hints a beacon was found on a channel