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>

1 files changed, 192 insertions, 0 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 5d8748b4c8a2..a4e6c951950f 100644
--- 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 |