nl80211: support vendor dumpit commands

In order to transfer many items in vendor commands, support the
dumpit netlink method for them.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index f0889a2476439553f055b31b6c577b6eb03e4d55..0f54c9ef4c7d62a619fac81b55eed609b90617cd 100644 (file)
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2971,12 +2971,21 @@ enum wiphy_vendor_command_flags {
  * @doit: callback for the operation, note that wdev is %NULL if the
  *     flags didn't ask for a wdev and non-%NULL otherwise; the data
  *     pointer may be %NULL if userspace provided no data at all
+ * @dumpit: dump callback, for transferring bigger/multiple items. The
+ *     @storage points to cb->args[5], ie. is preserved over the multiple
+ *     dumpit calls.
+ * It's recommended to not have the same sub command with both @doit and
+ * @dumpit, so that userspace can assume certain ones are get and others
+ * are used with dump requests.
  */
 struct wiphy_vendor_command {
        struct nl80211_vendor_cmd_info info;
        u32 flags;
        int (*doit)(struct wiphy *wiphy, struct wireless_dev *wdev,
                    const void *data, int data_len);
+       int (*dumpit)(struct wiphy *wiphy, struct wireless_dev *wdev,
+                     struct sk_buff *skb, const void *data, int data_len,
+                     unsigned long *storage);
 };
 
 /**

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 5d8748b4c8a2d20f76c38a8394888c7fe56924bf..a4e6c951950f71b67f0cc75c155576148c885e24 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3,6 +3,7 @@
  *
  * Copyright 2006-2010 Johannes Berg <johannes@sipsolutions.net>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
+ * Copyright 2015      Intel Deutschland GmbH
  */
 
 #include <linux/if.h>
@@ -9938,6 +9939,9 @@ static int nl80211_vendor_cmd(struct sk_buff *skb, struct genl_info *info)
                                if (!wdev->netdev && !wdev->p2p_started)
                                        return -ENETDOWN;
                        }
+
+                       if (!vcmd->doit)
+                               return -EOPNOTSUPP;
                } else {
                        wdev = NULL;
                }
@@ -9957,6 +9961,193 @@ static int nl80211_vendor_cmd(struct sk_buff *skb, struct genl_info *info)
        return -EOPNOTSUPP;
 }
 
+static int nl80211_prepare_vendor_dump(struct sk_buff *skb,
+                                      struct netlink_callback *cb,
+                                      struct cfg80211_registered_device **rdev,
+                                      struct wireless_dev **wdev)
+{
+       u32 vid, subcmd;
+       unsigned int i;
+       int vcmd_idx = -1;
+       int err;
+       void *data = NULL;
+       unsigned int data_len = 0;
+
+       rtnl_lock();
+
+       if (cb->args[0]) {
+               /* subtract the 1 again here */
+               struct wiphy *wiphy = wiphy_idx_to_wiphy(cb->args[0] - 1);
+               struct wireless_dev *tmp;
+
+               if (!wiphy) {
+                       err = -ENODEV;
+                       goto out_unlock;
+               }
+               *rdev = wiphy_to_rdev(wiphy);
+               *wdev = NULL;
+
+               if (cb->args[1]) {
+                       list_for_each_entry(tmp, &(*rdev)->wdev_list, list) {
+                               if (tmp->identifier == cb->args[1] - 1) {
+                                       *wdev = tmp;
+                                       break;
+                               }
+                       }
+               }
+
+               /* keep rtnl locked in successful case */
+               return 0;
+       }
+
+       err = nlmsg_parse(cb->nlh, GENL_HDRLEN + nl80211_fam.hdrsize,
+                         nl80211_fam.attrbuf, nl80211_fam.maxattr,
+                         nl80211_policy);
+       if (err)
+               goto out_unlock;
+
+       if (!nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_ID] ||
+           !nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_SUBCMD]) {
+               err = -EINVAL;
+               goto out_unlock;
+       }
+
+       *wdev = __cfg80211_wdev_from_attrs(sock_net(skb->sk),
+                                          nl80211_fam.attrbuf);
+       if (IS_ERR(*wdev))
+               *wdev = NULL;
+
+       *rdev = __cfg80211_rdev_from_attrs(sock_net(skb->sk),
+                                          nl80211_fam.attrbuf);
+       if (IS_ERR(*rdev)) {
+               err = PTR_ERR(*rdev);
+               goto out_unlock;
+       }
+
+       vid = nla_get_u32(nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_ID]);
+       subcmd = nla_get_u32(nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_SUBCMD]);
+
+       for (i = 0; i < (*rdev)->wiphy.n_vendor_commands; i++) {
+               const struct wiphy_vendor_command *vcmd;
+
+               vcmd = &(*rdev)->wiphy.vendor_commands[i];
+
+               if (vcmd->info.vendor_id != vid || vcmd->info.subcmd != subcmd)
+                       continue;
+
+               if (!vcmd->dumpit) {
+                       err = -EOPNOTSUPP;
+                       goto out_unlock;
+               }
+
+               vcmd_idx = i;
+               break;
+       }
+
+       if (vcmd_idx < 0) {
+               err = -EOPNOTSUPP;
+               goto out_unlock;
+       }
+
+       if (nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_DATA]) {
+               data = nla_data(nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_DATA]);
+               data_len = nla_len(nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_DATA]);
+       }
+
+       /* 0 is the first index - add 1 to parse only once */
+       cb->args[0] = (*rdev)->wiphy_idx + 1;
+       /* add 1 to know if it was NULL */
+       cb->args[1] = *wdev ? (*wdev)->identifier + 1 : 0;
+       cb->args[2] = vcmd_idx;
+       cb->args[3] = (unsigned long)data;
+       cb->args[4] = data_len;
+
+       /* keep rtnl locked in successful case */
+       return 0;
+ out_unlock:
+       rtnl_unlock();
+       return err;
+}
+
+static int nl80211_vendor_cmd_dump(struct sk_buff *skb,
+                                  struct netlink_callback *cb)
+{
+       struct cfg80211_registered_device *rdev;
+       struct wireless_dev *wdev;
+       unsigned int vcmd_idx;
+       const struct wiphy_vendor_command *vcmd;
+       void *data;
+       int data_len;
+       int err;
+       struct nlattr *vendor_data;
+
+       err = nl80211_prepare_vendor_dump(skb, cb, &rdev, &wdev);
+       if (err)
+               return err;
+
+       vcmd_idx = cb->args[2];
+       data = (void *)cb->args[3];
+       data_len = cb->args[4];
+       vcmd = &rdev->wiphy.vendor_commands[vcmd_idx];
+
+       if (vcmd->flags & (WIPHY_VENDOR_CMD_NEED_WDEV |
+                          WIPHY_VENDOR_CMD_NEED_NETDEV)) {
+               if (!wdev)
+                       return -EINVAL;
+               if (vcmd->flags & WIPHY_VENDOR_CMD_NEED_NETDEV &&
+                   !wdev->netdev)
+                       return -EINVAL;
+
+               if (vcmd->flags & WIPHY_VENDOR_CMD_NEED_RUNNING) {
+                       if (wdev->netdev &&
+                           !netif_running(wdev->netdev))
+                               return -ENETDOWN;
+                       if (!wdev->netdev && !wdev->p2p_started)
+                               return -ENETDOWN;
+               }
+       }
+
+       while (1) {
+               void *hdr = nl80211hdr_put(skb, NETLINK_CB(cb->skb).portid,
+                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
+                                          NL80211_CMD_VENDOR);
+               if (!hdr)
+                       break;
+
+               if (nla_put_u32(skb, NL80211_ATTR_WIPHY, rdev->wiphy_idx) ||
+                   (wdev && nla_put_u64(skb, NL80211_ATTR_WDEV,
+                                        wdev_id(wdev)))) {
+                       genlmsg_cancel(skb, hdr);
+                       break;
+               }
+
+               vendor_data = nla_nest_start(skb, NL80211_ATTR_VENDOR_DATA);
+               if (!vendor_data) {
+                       genlmsg_cancel(skb, hdr);
+                       break;
+               }
+
+               err = vcmd->dumpit(&rdev->wiphy, wdev, skb, data, data_len,
+                                  (unsigned long *)&cb->args[5]);
+               nla_nest_end(skb, vendor_data);
+
+               if (err == -ENOBUFS || err == -ENOENT) {
+                       genlmsg_cancel(skb, hdr);
+                       break;
+               } else if (err) {
+                       genlmsg_cancel(skb, hdr);
+                       goto out;
+               }
+
+               genlmsg_end(skb, hdr);
+       }
+
+       err = skb->len;
+ out:
+       rtnl_unlock();
+       return err;
+}
+
 struct sk_buff *__cfg80211_alloc_reply_skb(struct wiphy *wiphy,
                                           enum nl80211_commands cmd,
                                           enum nl80211_attrs attr,
@@ -10994,6 +11185,7 @@ static const struct genl_ops nl80211_ops[] = {
        {
                .cmd = NL80211_CMD_VENDOR,
                .doit = nl80211_vendor_cmd,
+               .dumpit = nl80211_vendor_cmd_dump,
                .policy = nl80211_policy,
                .flags = GENL_ADMIN_PERM,
                .internal_flags = NL80211_FLAG_NEED_WIPHY |