nl80211: Add monitor interface configuration flags

This allows precise control over what a monitor interface shows.

Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 101 insertions, 6 deletions

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 63695060db9f..a9f0b93324a2 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -164,6 +164,9 @@ enum nl80211_commands {
  * @NL80211_ATTR_WIPHY_BANDS: Information about an operating bands,
  *      consisting of a nested array.
  *
+ * @NL80211_ATTR_MNTR_FLAGS: flags, nested element with NLA_FLAG attributes of
+ *      &enum nl80211_mntr_flags.
+ *
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
  */
@@ -200,6 +203,8 @@ enum nl80211_attrs {
 
         NL80211_ATTR_WIPHY_BANDS,
 
+        NL80211_ATTR_MNTR_FLAGS,
+
         /* add attributes here, update the policy in nl80211.c */
 
         __NL80211_ATTR_AFTER_LAST,
@@ -344,4 +349,34 @@ enum nl80211_bitrate_attr {
         NL80211_BITRATE_ATTR_MAX = __NL80211_BITRATE_ATTR_AFTER_LAST - 1
 };
 
+/**
+ * enum nl80211_mntr_flags - monitor configuration flags
+ *
+ * Monitor configuration flags.
+ *
+ * @__NL80211_MNTR_FLAG_INVALID: reserved
+ *
+ * @NL80211_MNTR_FLAG_FCSFAIL: pass frames with bad FCS
+ * @NL80211_MNTR_FLAG_PLCPFAIL: pass frames with bad PLCP
+ * @NL80211_MNTR_FLAG_CONTROL: pass control frames
+ * @NL80211_MNTR_FLAG_OTHER_BSS: disable BSSID filtering
+ * @NL80211_MNTR_FLAG_COOK_FRAMES: report frames after processing.
+ *      overrides all other flags.
+ *
+ * @__NL80211_MNTR_FLAG_AFTER_LAST: internal use
+ * @NL80211_MNTR_FLAG_MAX: highest possible monitor flag
+ */
+enum nl80211_mntr_flags {
+        __NL80211_MNTR_FLAG_INVALID,
+        NL80211_MNTR_FLAG_FCSFAIL,
+        NL80211_MNTR_FLAG_PLCPFAIL,
+        NL80211_MNTR_FLAG_CONTROL,
+        NL80211_MNTR_FLAG_OTHER_BSS,
+        NL80211_MNTR_FLAG_COOK_FRAMES,
+
+        /* keep last */
+        __NL80211_MNTR_FLAG_AFTER_LAST,
+        NL80211_MNTR_FLAG_MAX = __NL80211_MNTR_FLAG_AFTER_LAST - 1
+};
+
 #endif /* __LINUX_NL80211_H */
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index bcc480b8892a..ab4caf63954f 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -163,6 +163,26 @@ struct station_stats {
         u32 tx_bytes;
 };
 
+/**
+ * enum monitor_flags - monitor flags
+ *
+ * Monitor interface configuration flags. Note that these must be the bits
+ * according to the nl80211 flags.
+ *
+ * @MONITOR_FLAG_FCSFAIL: pass frames with bad FCS
+ * @MONITOR_FLAG_PLCPFAIL: pass frames with bad PLCP
+ * @MONITOR_FLAG_CONTROL: pass control frames
+ * @MONITOR_FLAG_OTHER_BSS: disable BSSID filtering
+ * @MONITOR_FLAG_COOK_FRAMES: report frames after processing
+ */
+enum monitor_flags {
+        MONITOR_FLAG_FCSFAIL            = 1<<NL80211_MNTR_FLAG_FCSFAIL,
+        MONITOR_FLAG_PLCPFAIL           = 1<<NL80211_MNTR_FLAG_PLCPFAIL,
+        MONITOR_FLAG_CONTROL            = 1<<NL80211_MNTR_FLAG_CONTROL,
+        MONITOR_FLAG_OTHER_BSS          = 1<<NL80211_MNTR_FLAG_OTHER_BSS,
+        MONITOR_FLAG_COOK_FRAMES        = 1<<NL80211_MNTR_FLAG_COOK_FRAMES,
+};
+
 /* from net/wireless.h */
 struct wiphy;
 
@@ -213,10 +233,10 @@ struct wiphy;
  */
 struct cfg80211_ops {
         int     (*add_virtual_intf)(struct wiphy *wiphy, char *name,
-                                    enum nl80211_iftype type);
+                                    enum nl80211_iftype type, u32 *flags);
         int     (*del_virtual_intf)(struct wiphy *wiphy, int ifindex);
         int     (*change_virtual_intf)(struct wiphy *wiphy, int ifindex,
-                                       enum nl80211_iftype type);
+                                       enum nl80211_iftype type, u32 *flags);
 
         int     (*add_key)(struct wiphy *wiphy, struct net_device *netdev,
                            u8 key_index, u8 *mac_addr,
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 15b8cf94f510..706418d477c2 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -34,7 +34,7 @@ nl80211_type_to_mac80211_type(enum nl80211_iftype type)
 }
 
 static int ieee80211_add_iface(struct wiphy *wiphy, char *name,
-                               enum nl80211_iftype type)
+                               enum nl80211_iftype type, u32 *flags)
 {
         struct ieee80211_local *local = wiphy_priv(wiphy);
         enum ieee80211_if_types itype;
@@ -69,7 +69,7 @@ static int ieee80211_del_iface(struct wiphy *wiphy, int ifindex)
 }
 
 static int ieee80211_change_iface(struct wiphy *wiphy, int ifindex,
-                                  enum nl80211_iftype type)
+                                  enum nl80211_iftype type, u32 *flags)
 {
         struct ieee80211_local *local = wiphy_priv(wiphy);
         struct net_device *dev;
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index b123f58d3909..5b3474798b8d 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -82,6 +82,7 @@ static struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] __read_mostly = {
         [NL80211_ATTR_STA_SUPPORTED_RATES] = { .type = NLA_BINARY,
                                                .len = NL80211_MAX_SUPP_RATES },
         [NL80211_ATTR_STA_VLAN] = { .type = NLA_U32 },
+        [NL80211_ATTR_MNTR_FLAGS] = { .type = NLA_NESTED },
 };
 
 /* message building helper */
@@ -336,12 +337,42 @@ static int nl80211_get_interface(struct sk_buff *skb, struct genl_info *info)
         return -ENOBUFS;
 }
 
+static const struct nla_policy mntr_flags_policy[NL80211_MNTR_FLAG_MAX + 1] = {
+        [NL80211_MNTR_FLAG_FCSFAIL] = { .type = NLA_FLAG },
+        [NL80211_MNTR_FLAG_PLCPFAIL] = { .type = NLA_FLAG },
+        [NL80211_MNTR_FLAG_CONTROL] = { .type = NLA_FLAG },
+        [NL80211_MNTR_FLAG_OTHER_BSS] = { .type = NLA_FLAG },
+        [NL80211_MNTR_FLAG_COOK_FRAMES] = { .type = NLA_FLAG },
+};
+
+static int parse_monitor_flags(struct nlattr *nla, u32 *mntrflags)
+{
+        struct nlattr *flags[NL80211_MNTR_FLAG_MAX + 1];
+        int flag;
+
+        *mntrflags = 0;
+
+        if (!nla)
+                return -EINVAL;
+
+        if (nla_parse_nested(flags, NL80211_MNTR_FLAG_MAX,
+                             nla, mntr_flags_policy))
+                return -EINVAL;
+
+        for (flag = 1; flag <= NL80211_MNTR_FLAG_MAX; flag++)
+                if (flags[flag])
+                        *mntrflags |= (1<<flag);
+
+        return 0;
+}
+
 static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
 {
         struct cfg80211_registered_device *drv;
         int err, ifindex;
         enum nl80211_iftype type;
         struct net_device *dev;
+        u32 flags;
 
         if (info->attrs[NL80211_ATTR_IFTYPE]) {
                 type = nla_get_u32(info->attrs[NL80211_ATTR_IFTYPE]);
@@ -362,7 +393,11 @@ static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
         }
 
         rtnl_lock();
-        err = drv->ops->change_virtual_intf(&drv->wiphy, ifindex, type);
+        err = parse_monitor_flags(type == NL80211_IFTYPE_MONITOR ?
+                                  info->attrs[NL80211_ATTR_MNTR_FLAGS] : NULL,
+                                  &flags);
+        err = drv->ops->change_virtual_intf(&drv->wiphy, ifindex,
+                                            type, err ? NULL : &flags);
         rtnl_unlock();
 
  unlock:
@@ -375,6 +410,7 @@ static int nl80211_new_interface(struct sk_buff *skb, struct genl_info *info)
         struct cfg80211_registered_device *drv;
         int err;
         enum nl80211_iftype type = NL80211_IFTYPE_UNSPECIFIED;
+        u32 flags;
 
         if (!info->attrs[NL80211_ATTR_IFNAME])
                 return -EINVAL;
@@ -395,8 +431,12 @@ static int nl80211_new_interface(struct sk_buff *skb, struct genl_info *info)
         }
 
         rtnl_lock();
+        err = parse_monitor_flags(type == NL80211_IFTYPE_MONITOR ?
+                                  info->attrs[NL80211_ATTR_MNTR_FLAGS] : NULL,
+                                  &flags);
         err = drv->ops->add_virtual_intf(&drv->wiphy,
-                nla_data(info->attrs[NL80211_ATTR_IFNAME]), type);
+                nla_data(info->attrs[NL80211_ATTR_IFNAME]),
+                type, err ? NULL : &flags);
         rtnl_unlock();
 
  unlock: