nl80211: add src and dst addr attributes for control port tx/rx

When using control port over nl80211 in AP mode with
pre-authentication, APs need to forward frames to other
APs defined by their MAC address. Before this patch,
pre-auth frames reaching user space over nl80211 control
port  have no longer any information about the dest attached,
which can be used for forwarding to a controller or injecting
the frame back to a ethernet interface over a AF_PACKET
socket.
Analog problems exist, when forwarding pre-auth frames from
AP -> STA.

This patch therefore adds the NL80211_ATTR_DST_MAC and
NL80211_ATTR_SRC_MAC attributes to provide more context
information when forwarding.
The respective arguments are optional on tx and included on rx.
Therefore unaware existing software is not affected.

Software which wants to detect this feature, can do so
by checking against:
  NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211_MAC_ADDRS

Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
Link: https://lore.kernel.org/r/20200115125522.3755-1-markus.theil@tu-ilmenau.de
[split into separate cfg80211/mac80211 patches]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index c3a9b375d3ca175893440cedd02292c57caf6e5c..ec0de3c43c6177ae4a1d0539ed150e7f33e51682 100644 (file)
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -3969,7 +3969,8 @@ struct cfg80211_ops {
        int     (*tx_control_port)(struct wiphy *wiphy,
                                   struct net_device *dev,
                                   const u8 *buf, size_t len,
-                                  const u8 *dest, const __be16 proto,
+                                  const u8 *dest, const u8 *src,
+                                  const __be16 proto,
                                   const bool noencrypt);
 
        int     (*get_ftm_responder_stats)(struct wiphy *wiphy,

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 350ab86fe20e809754fdc4ad51e2e856f9c8f9fa..158bccb4a47b9774df36f6bd83baed5591032292 100644 (file)
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -1039,11 +1039,14 @@
  *     a control port frame and as a notification that a control port frame
  *     has been received. %NL80211_ATTR_FRAME is used to specify the
  *     frame contents.  The frame is the raw EAPoL data, without ethernet or
- *     802.11 headers.
+ *     802.11 headers. An optional %NL80211_ATTR_SRC_MAC can be used to send
+ *     pre-auth frames to STAs on behalf of other APs.
  *     When used as an event indication %NL80211_ATTR_CONTROL_PORT_ETHERTYPE,
  *     %NL80211_ATTR_CONTROL_PORT_NO_ENCRYPT and %NL80211_ATTR_MAC are added
  *     indicating the protocol type of the received frame; whether the frame
  *     was received unencrypted and the MAC address of the peer respectively.
+ *     %NL80211_ATTR_DST_MAC can be used to forward pre-auth frames in
+ *     userspace while using AP mode.
  *
  * @NL80211_CMD_RELOAD_REGDB: Request that the regdb firmware file is reloaded.
  *
@@ -2409,6 +2412,9 @@ enum nl80211_commands {
  *     %NL80211_ATTR_AKM_SUITES are default capabilities if AKM suites not
  *     advertised for a specific interface type.
  *
+ * @NL80211_ATTR_SRC_MAC: MAC address used in control port over nl80211 transmit
+ * @NL80211_ATTR_DST_MAC: MAC address used in control port over nl80211 receive
+ *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
@@ -2877,6 +2883,9 @@ enum nl80211_attrs {
 
        NL80211_ATTR_IFTYPE_AKM_SUITES,
 
+       NL80211_ATTR_SRC_MAC,
+       NL80211_ATTR_DST_MAC,
+
        /* add attributes here, update the policy in nl80211.c */
 
        __NL80211_ATTR_AFTER_LAST,
@@ -5539,6 +5548,10 @@ enum nl80211_feature_flags {
  *     feature, which prevents bufferbloat by using the expected transmission
  *     time to limit the amount of data buffered in the hardware.
  *
+ * @NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211_MAC_ADDRS: The driver
+ *     can use src and dst MAC addresses with control port over nl80211 rx
+ *     and tx operations.
+ *
  * @NUM_NL80211_EXT_FEATURES: number of extended features.
  * @MAX_NL80211_EXT_FEATURES: highest extended feature index.
  */
@@ -5586,6 +5599,7 @@ enum nl80211_ext_feature_index {
        NL80211_EXT_FEATURE_SAE_OFFLOAD,
        NL80211_EXT_FEATURE_VLAN_OFFLOAD,
        NL80211_EXT_FEATURE_AQL,
+       NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211_MAC_ADDRS,
 
        /* add new features before the definition below */
        NUM_NL80211_EXT_FEATURES,

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 8a49d78ad7c94ab62ed44fa99196002a334a987d..da9eaa9ee37ed3a5e919a0c2b7301c88f91fce4c 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1792,7 +1792,8 @@ void ieee80211_check_fast_xmit_iface(struct ieee80211_sub_if_data *sdata);
 void ieee80211_clear_fast_xmit(struct sta_info *sta);
 int ieee80211_tx_control_port(struct wiphy *wiphy, struct net_device *dev,
                              const u8 *buf, size_t len,
-                             const u8 *dest, __be16 proto, bool unencrypted);
+                             const u8 *dest, const u8 *src, __be16 proto,
+                             bool unencrypted);
 int ieee80211_probe_mesh_link(struct wiphy *wiphy, struct net_device *dev,
                              const u8 *buf, size_t len);
 

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 4296d9d713113b12aca491eb10082a2ff72206ba..059c66b6bb5ce1271f8ea2d9a5ec6088985fc089 100644 (file)
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -5285,7 +5285,8 @@ void __ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
 
 int ieee80211_tx_control_port(struct wiphy *wiphy, struct net_device *dev,
                              const u8 *buf, size_t len,
-                             const u8 *dest, __be16 proto, bool unencrypted)
+                             const u8 *dest, const u8 *src, __be16 proto,
+                             bool unencrypted)
 {
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
        struct ieee80211_local *local = sdata->local;

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 4c0ea54e0f590621a287ce70c53904a7615bccbb..33fe6ac1c2425af6afcc4aaa3d683381f9043878 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -633,6 +633,8 @@ const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
        [NL80211_ATTR_HE_OBSS_PD] = NLA_POLICY_NESTED(he_obss_pd_policy),
        [NL80211_ATTR_VLAN_ID] = NLA_POLICY_RANGE(NLA_U16, 1, VLAN_N_VID - 2),
        [NL80211_ATTR_HE_BSS_COLOR] = NLA_POLICY_NESTED(he_bss_color_policy),
+       [NL80211_ATTR_SRC_MAC] = NLA_POLICY_ETH_ADDR,
+       [NL80211_ATTR_DST_MAC] = NLA_POLICY_ETH_ADDR,
 };
 
 /* policy for the key attributes */
@@ -13694,6 +13696,7 @@ static int nl80211_tx_control_port(struct sk_buff *skb, struct genl_info *info)
        const u8 *buf;
        size_t len;
        u8 *dest;
+       u8 src[ETH_ALEN];
        u16 proto;
        bool noencrypt;
        int err;
@@ -13731,6 +13734,13 @@ static int nl80211_tx_control_port(struct sk_buff *skb, struct genl_info *info)
                goto out;
        }
 
+       /* copy src address under wdev_lock, as we may copy wdev_address */
+       if (info->attrs[NL80211_ATTR_SRC_MAC])
+               ether_addr_copy(src,
+                               nla_data(info->attrs[NL80211_ATTR_SRC_MAC]));
+       else
+               ether_addr_copy(src, wdev_address(wdev));
+
        wdev_unlock(wdev);
 
        buf = nla_data(info->attrs[NL80211_ATTR_FRAME]);
@@ -13741,7 +13751,7 @@ static int nl80211_tx_control_port(struct sk_buff *skb, struct genl_info *info)
                nla_get_flag(info->attrs[NL80211_ATTR_CONTROL_PORT_NO_ENCRYPT]);
 
        return rdev_tx_control_port(rdev, dev, buf, len,
-                                   dest, cpu_to_be16(proto), noencrypt);
+                                   dest, src, cpu_to_be16(proto), noencrypt);
 
  out:
        wdev_unlock(wdev);
@@ -15996,7 +16006,8 @@ static int __nl80211_rx_control_port(struct net_device *dev,
        struct wireless_dev *wdev = dev->ieee80211_ptr;
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
        struct ethhdr *ehdr = eth_hdr(skb);
-       const u8 *addr = ehdr->h_source;
+       const u8 *daddr = ehdr->h_dest;
+       const u8 *saddr = ehdr->h_source;
        u16 proto = be16_to_cpu(skb->protocol);
        struct sk_buff *msg;
        void *hdr;
@@ -16021,7 +16032,8 @@ static int __nl80211_rx_control_port(struct net_device *dev,
            nla_put_u32(msg, NL80211_ATTR_IFINDEX, dev->ifindex) ||
            nla_put_u64_64bit(msg, NL80211_ATTR_WDEV, wdev_id(wdev),
                              NL80211_ATTR_PAD) ||
-           nla_put(msg, NL80211_ATTR_MAC, ETH_ALEN, addr) ||
+           nla_put(msg, NL80211_ATTR_MAC, ETH_ALEN, saddr) ||
+           nla_put(msg, NL80211_ATTR_DST_MAC, ETH_ALEN, daddr) ||
            nla_put_u16(msg, NL80211_ATTR_CONTROL_PORT_ETHERTYPE, proto) ||
            (unencrypted && nla_put_flag(msg,
                                         NL80211_ATTR_CONTROL_PORT_NO_ENCRYPT)))

diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
index e853a4fe6f97f2cd716cdd5253a4d47f364b9d8a..39e6c1db30925326ce0e364111b33823e3af88f4 100644 (file)
--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -730,14 +730,14 @@ static inline int rdev_mgmt_tx(struct cfg80211_registered_device *rdev,
 static inline int rdev_tx_control_port(struct cfg80211_registered_device *rdev,
                                       struct net_device *dev,
                                       const void *buf, size_t len,
-                                      const u8 *dest, __be16 proto,
-                                      const bool noencrypt)
+                                      const u8 *dest, const u8 *src,
+                                      __be16 proto, const bool noencrypt)
 {
        int ret;
        trace_rdev_tx_control_port(&rdev->wiphy, dev, buf, len,
-                                  dest, proto, noencrypt);
+                                  dest, src, proto, noencrypt);
        ret = rdev->ops->tx_control_port(&rdev->wiphy, dev, buf, len,
-                                        dest, proto, noencrypt);
+                                        dest, src, proto, noencrypt);
        trace_rdev_return_int(&rdev->wiphy, ret);
        return ret;
 }

diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index d98ad2b3143b04dc1e75f69995a13f725c739984..fefa255fd062ddb192b70c83b0177b16e6f75e00 100644 (file)
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -1923,27 +1923,31 @@ TRACE_EVENT(rdev_mgmt_tx,
 
 TRACE_EVENT(rdev_tx_control_port,
        TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
-                const u8 *buf, size_t len, const u8 *dest, __be16 proto,
+                const u8 *buf, size_t len,
+                const u8 *dest, const u8 *src, __be16 proto,
                 bool unencrypted),
-       TP_ARGS(wiphy, netdev, buf, len, dest, proto, unencrypted),
+       TP_ARGS(wiphy, netdev, buf, len, dest, src, proto, unencrypted),
        TP_STRUCT__entry(
                WIPHY_ENTRY
                NETDEV_ENTRY
                MAC_ENTRY(dest)
-               __field(__be16, proto)
+               MAC_ENTRY(src)
+               __field(u16, proto)
                __field(bool, unencrypted)
        ),
        TP_fast_assign(
                WIPHY_ASSIGN;
                NETDEV_ASSIGN;
                MAC_ASSIGN(dest, dest);
-               __entry->proto = proto;
+               MAC_ASSIGN(src, src);
+               __entry->proto = be16_to_cpu(proto);
                __entry->unencrypted = unencrypted;
        ),
-       TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", " MAC_PR_FMT ","
-                 " proto: 0x%x, unencrypted: %s",
-                 WIPHY_PR_ARG, NETDEV_PR_ARG, MAC_PR_ARG(dest),
-                 be16_to_cpu(__entry->proto),
+       TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", dest: " MAC_PR_FMT
+                 ", src: " MAC_PR_FMT ", proto: 0x%x, unencrypted: %s",
+                 WIPHY_PR_ARG, NETDEV_PR_ARG,
+                 MAC_PR_ARG(dest), MAC_PR_ARG(src),
+                 __entry->proto,
                  BOOL_TO_STR(__entry->unencrypted))
 );
 
@@ -2835,6 +2839,7 @@ TRACE_EVENT(cfg80211_rx_control_port,
        TP_STRUCT__entry(
                NETDEV_ENTRY
                __field(int, len)
+               MAC_ENTRY(to)
                MAC_ENTRY(from)
                __field(u16, proto)
                __field(bool, unencrypted)
@@ -2842,12 +2847,14 @@ TRACE_EVENT(cfg80211_rx_control_port,
        TP_fast_assign(
                NETDEV_ASSIGN;
                __entry->len = skb->len;
+               MAC_ASSIGN(to, eth_hdr(skb)->h_dest);
                MAC_ASSIGN(from, eth_hdr(skb)->h_source);
                __entry->proto = be16_to_cpu(skb->protocol);
                __entry->unencrypted = unencrypted;
        ),
-       TP_printk(NETDEV_PR_FMT ", len=%d, " MAC_PR_FMT ", proto: 0x%x, unencrypted: %s",
-                 NETDEV_PR_ARG, __entry->len, MAC_PR_ARG(from),
+       TP_printk(NETDEV_PR_FMT ", len=%d, dest: " MAC_PR_FMT
+                 ", src: " MAC_PR_FMT ", proto: 0x%x, unencrypted: %s",
+                 NETDEV_PR_ARG, __entry->len, MAC_PR_ARG(to), MAC_PR_ARG(from),
                  __entry->proto, BOOL_TO_STR(__entry->unencrypted))
 );