cfg80211/nl80211: Optional authentication offload to userspace

This interface allows the host driver to offload the authentication to
user space. This is exclusively defined for host drivers that do not
define separate commands for authentication and association, but rely on
userspace SME (e.g., in wpa_supplicant for the ~WPA_DRIVER_FLAGS_SME
case) for the authentication to happen. This can be used to implement
SAE without full implementation in the kernel/firmware while still being
able to use NL80211_CMD_CONNECT with driver-based BSS selection.

Host driver sends NL80211_CMD_EXTERNAL_AUTH event to start/abort
authentication to the port on which connect is triggered and status
of authentication is further indicated by user space to host
driver through the same command response interface.

User space entities advertise this capability through the
NL80211_ATTR_EXTERNAL_AUTH_SUPP flag in the NL80211_CMD_CONNECT request.
Host drivers shall look at this capability to offload the authentication.

Signed-off-by: Srinivas Dasari <dasaris@qti.qualcomm.com>
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
[add socket connection ownership check]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 132 insertions, 0 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index dd249ec9f228..aa6b64069c80 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -420,6 +420,7 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	[NL80211_ATTR_FILS_CACHE_ID] = { .len = 2 },
 	[NL80211_ATTR_PMK] = { .type = NLA_BINARY, .len = PMK_MAX_LEN },
 	[NL80211_ATTR_SCHED_SCAN_MULTI] = { .type = NLA_FLAG },
+	[NL80211_ATTR_EXTERNAL_AUTH_SUPPORT] = { .type = NLA_FLAG },
 };
 
 /* policy for the key attributes */
@@ -9161,6 +9162,15 @@ static int nl80211_connect(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 	}
 
+	if (nla_get_flag(info->attrs[NL80211_ATTR_EXTERNAL_AUTH_SUPPORT])) {
+		if (!info->attrs[NL80211_ATTR_SOCKET_OWNER]) {
+			GENL_SET_ERR_MSG(info,
+					 "external auth requires connection ownership");
+			return -EINVAL;
+		}
+		connect.flags |= CONNECT_REQ_EXTERNAL_AUTH_SUPPORT;
+	}
+
 	wdev_lock(dev->ieee80211_ptr);
 
 	err = cfg80211_connect(rdev, dev, &connect, connkeys,
@@ -12469,6 +12479,41 @@ static int nl80211_del_pmk(struct sk_buff *skb, struct genl_info *info)
 	return ret;
 }
 
+static int nl80211_external_auth(struct sk_buff *skb, struct genl_info *info)
+{
+	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	struct net_device *dev = info->user_ptr[1];
+	struct cfg80211_external_auth_params params;
+
+	if (rdev->ops->external_auth)
+		return -EOPNOTSUPP;
+
+	if (!info->attrs[NL80211_ATTR_SSID])
+		return -EINVAL;
+
+	if (!info->attrs[NL80211_ATTR_BSSID])
+		return -EINVAL;
+
+	if (!info->attrs[NL80211_ATTR_STATUS_CODE])
+		return -EINVAL;
+
+	memset(&params, 0, sizeof(params));
+
+	params.ssid.ssid_len = nla_len(info->attrs[NL80211_ATTR_SSID]);
+	if (params.ssid.ssid_len == 0 ||
+	    params.ssid.ssid_len > IEEE80211_MAX_SSID_LEN)
+		return -EINVAL;
+	memcpy(params.ssid.ssid, nla_data(info->attrs[NL80211_ATTR_SSID]),
+	       params.ssid.ssid_len);
+
+	memcpy(params.bssid, nla_data(info->attrs[NL80211_ATTR_BSSID]),
+	       ETH_ALEN);
+
+	params.status = nla_get_u16(info->attrs[NL80211_ATTR_STATUS_CODE]);
+
+	return rdev_external_auth(rdev, dev, &params);
+}
+
 #define NL80211_FLAG_NEED_WIPHY		0x01
 #define NL80211_FLAG_NEED_NETDEV	0x02
 #define NL80211_FLAG_NEED_RTNL		0x04
@@ -13364,6 +13409,14 @@ static const struct genl_ops nl80211_ops[] = {
 		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
 				  NL80211_FLAG_NEED_RTNL,
 	},
+	{
+		.cmd = NL80211_CMD_EXTERNAL_AUTH,
+		.doit = nl80211_external_auth,
+		.policy = nl80211_policy,
+		.flags = GENL_ADMIN_PERM,
+		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
+				  NL80211_FLAG_NEED_RTNL,
+	},
 
 };
 
@@ -15375,6 +15428,47 @@ void nl80211_send_ap_stopped(struct wireless_dev *wdev)
 	nlmsg_free(msg);
 }
 
+int cfg80211_external_auth_request(struct net_device *dev,
+				   struct cfg80211_external_auth_params *params,
+				   gfp_t gfp)
+{
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
+	struct sk_buff *msg;
+	void *hdr;
+
+	if (!wdev->conn_owner_nlportid)
+		return -EINVAL;
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
+	if (!msg)
+		return -ENOMEM;
+
+	hdr = nl80211hdr_put(msg, 0, 0, 0, NL80211_CMD_EXTERNAL_AUTH);
+	if (!hdr)
+		goto nla_put_failure;
+
+	if (nla_put_u32(msg, NL80211_ATTR_WIPHY, rdev->wiphy_idx) ||
+	    nla_put_u32(msg, NL80211_ATTR_IFINDEX, dev->ifindex) ||
+	    nla_put_u32(msg, NL80211_ATTR_AKM_SUITES, params->key_mgmt_suite) ||
+	    nla_put_u32(msg, NL80211_ATTR_EXTERNAL_AUTH_ACTION,
+			params->action) ||
+	    nla_put(msg, NL80211_ATTR_BSSID, ETH_ALEN, params->bssid) ||
+	    nla_put(msg, NL80211_ATTR_SSID, params->ssid.ssid_len,
+		    params->ssid.ssid))
+		goto nla_put_failure;
+
+	genlmsg_end(msg, hdr);
+	genlmsg_unicast(wiphy_net(&rdev->wiphy), msg,
+			wdev->conn_owner_nlportid);
+	return 0;
+
+ nla_put_failure:
+	nlmsg_free(msg);
+	return -ENOBUFS;
+}
+EXPORT_SYMBOL(cfg80211_external_auth_request);
+
 /* initialisation/exit functions */
 
 int __init nl80211_init(void)
diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
index 0c06240d25af..84f23ae015fc 100644
--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -1190,4 +1190,19 @@ static inline int rdev_del_pmk(struct cfg80211_registered_device *rdev,
 	trace_rdev_return_int(&rdev->wiphy, ret);
 	return ret;
 }
+
+static inline int
+rdev_external_auth(struct cfg80211_registered_device *rdev,
+		   struct net_device *dev,
+		   struct cfg80211_external_auth_params *params)
+{
+	int ret = -EOPNOTSUPP;
+
+	trace_rdev_external_auth(&rdev->wiphy, dev, params);
+	if (rdev->ops->external_auth)
+		ret = rdev->ops->external_auth(&rdev->wiphy, dev, params);
+	trace_rdev_return_int(&rdev->wiphy, ret);
+	return ret;
+}
+
 #endif /* __CFG80211_RDEV_OPS */
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index bcfedd39e7a3..5152938b358d 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -2319,6 +2319,29 @@ TRACE_EVENT(rdev_del_pmk,
 		  WIPHY_PR_ARG, NETDEV_PR_ARG, MAC_PR_ARG(aa))
 );
 
+TRACE_EVENT(rdev_external_auth,
+	    TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
+		     struct cfg80211_external_auth_params *params),
+	    TP_ARGS(wiphy, netdev, params),
+	    TP_STRUCT__entry(WIPHY_ENTRY
+			     NETDEV_ENTRY
+			     MAC_ENTRY(bssid)
+			     __array(u8, ssid, IEEE80211_MAX_SSID_LEN + 1)
+			     __field(u16, status)
+	    ),
+	    TP_fast_assign(WIPHY_ASSIGN;
+			   NETDEV_ASSIGN;
+			   MAC_ASSIGN(bssid, params->bssid);
+			   memset(__entry->ssid, 0, IEEE80211_MAX_SSID_LEN + 1);
+			   memcpy(__entry->ssid, params->ssid.ssid,
+				  params->ssid.ssid_len);
+			   __entry->status = params->status;
+	    ),
+	    TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", bssid: " MAC_PR_FMT
+		      ", ssid: %s, status: %u", WIPHY_PR_ARG, NETDEV_PR_ARG,
+		      __entry->bssid, __entry->ssid, __entry->status)
+);
+
 /*************************************************************
  *	     cfg80211 exported functions traces		     *
  *************************************************************/