[PATCH v3] ieee80211: Print human-readable disassoc/deauth reason codes

[Calvin Owens <jcalvinowens@gmail.com>]

Create a function to return a descriptive string for each reason code,
and print that in addition to the numeric value in the kernel log. These
codes are easily found on popular search engines, but one is generally
not able to access the internet when dealing with wireless connectivity
issues.

Changes in v2: Refactored array of strings into switch statement.
Changes in v3: Fix style problem, use simplifying macro for switch
statement, eliminate temporary enum variable.

Signed-off-by: Calvin Owens <jcalvinowens@gmail.com>
---
 include/net/mac80211.h | 10 +++++++++
 net/mac80211/main.c    | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++
 net/mac80211/mlme.c    | 12 +++++------
 3 files changed, 73 insertions(+), 6 deletions(-)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index f4ab2fb..d18acfe 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2971,6 +2971,16 @@ struct ieee80211_ops {
  */
 struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 					const struct ieee80211_ops *ops);
+/**
+ * ieee80211_get_reason_code_string - Get human readable reason code
+ *
+ * This function returns a string describing the @reason_code.
+ *
+ * @reason_code: Reason code
+ *
+ * Return: Human readable reason string, or "<INVALID>"
+ */
+const char *ieee80211_get_reason_code_string(u16 reason_code);
 
 /**
  * ieee80211_register_hw - Register hardware device
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index d767cfb..307b444 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -743,6 +743,63 @@ static int ieee80211_init_cipher_suites(struct ieee80211_local *local)
 	return 0;
 }
 
+#define case_WLAN(type) \
+	case WLAN_REASON_##type: return #type
+
+const char *ieee80211_get_reason_code_string(u16 reason_code)
+{
+	switch (reason_code) {
+	case_WLAN(UNSPECIFIED);
+	case_WLAN(PREV_AUTH_NOT_VALID);
+	case_WLAN(DEAUTH_LEAVING);
+	case_WLAN(DISASSOC_DUE_TO_INACTIVITY);
+	case_WLAN(DISASSOC_AP_BUSY);
+	case_WLAN(CLASS2_FRAME_FROM_NONAUTH_STA);
+	case_WLAN(CLASS3_FRAME_FROM_NONASSOC_STA);
+	case_WLAN(DISASSOC_STA_HAS_LEFT);
+	case_WLAN(STA_REQ_ASSOC_WITHOUT_AUTH);
+	case_WLAN(DISASSOC_BAD_POWER);
+	case_WLAN(DISASSOC_BAD_SUPP_CHAN);
+	case_WLAN(INVALID_IE);
+	case_WLAN(MIC_FAILURE);
+	case_WLAN(4WAY_HANDSHAKE_TIMEOUT);
+	case_WLAN(GROUP_KEY_HANDSHAKE_TIMEOUT);
+	case_WLAN(IE_DIFFERENT);
+	case_WLAN(INVALID_GROUP_CIPHER);
+	case_WLAN(INVALID_PAIRWISE_CIPHER);
+	case_WLAN(INVALID_AKMP);
+	case_WLAN(UNSUPP_RSN_VERSION);
+	case_WLAN(INVALID_RSN_IE_CAP);
+	case_WLAN(IEEE8021X_FAILED);
+	case_WLAN(CIPHER_SUITE_REJECTED);
+	case_WLAN(DISASSOC_UNSPECIFIED_QOS);
+	case_WLAN(DISASSOC_QAP_NO_BANDWIDTH);
+	case_WLAN(DISASSOC_LOW_ACK);
+	case_WLAN(DISASSOC_QAP_EXCEED_TXOP);
+	case_WLAN(QSTA_LEAVE_QBSS);
+	case_WLAN(QSTA_NOT_USE);
+	case_WLAN(QSTA_REQUIRE_SETUP);
+	case_WLAN(QSTA_TIMEOUT);
+	case_WLAN(QSTA_CIPHER_NOT_SUPP);
+	case_WLAN(MESH_PEER_CANCELED);
+	case_WLAN(MESH_MAX_PEERS);
+	case_WLAN(MESH_CONFIG);
+	case_WLAN(MESH_CLOSE);
+	case_WLAN(MESH_MAX_RETRIES);
+	case_WLAN(MESH_CONFIRM_TIMEOUT);
+	case_WLAN(MESH_INVALID_GTK);
+	case_WLAN(MESH_INCONSISTENT_PARAM);
+	case_WLAN(MESH_INVALID_SECURITY);
+	case_WLAN(MESH_PATH_ERROR);
+	case_WLAN(MESH_PATH_NOFORWARD);
+	case_WLAN(MESH_PATH_DEST_UNREACHABLE);
+	case_WLAN(MAC_EXISTS_IN_MBSS);
+	case_WLAN(MESH_CHAN_REGULATORY);
+	case_WLAN(MESH_CHAN);
+	default: return "<INVALID>";
+	}
+}
+
 int ieee80211_register_hw(struct ieee80211_hw *hw)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index fc1d824..5dec202 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2231,8 +2231,8 @@ static void ieee80211_rx_mgmt_deauth(struct ieee80211_sub_if_data *sdata,
 
 	reason_code = le16_to_cpu(mgmt->u.deauth.reason_code);
 
-	sdata_info(sdata, "deauthenticated from %pM (Reason: %u)\n",
-		   bssid, reason_code);
+	sdata_info(sdata, "deauthenticated from %pM (Reason: %u=%s)\n",
+		   bssid, reason_code, ieee80211_get_reason_code_string(reason_code));
 
 	ieee80211_set_disassoc(sdata, 0, 0, false, NULL);
 
@@ -4301,8 +4301,8 @@ int ieee80211_mgd_deauth(struct ieee80211_sub_if_data *sdata,
 	bool report_frame = false;
 
 	sdata_info(sdata,
-		   "deauthenticating from %pM by local choice (reason=%d)\n",
-		   req->bssid, req->reason_code);
+		   "deauthenticating from %pM by local choice (Reason: %u=%s)\n",
+		   req->bssid, req->reason_code, ieee80211_get_reason_code_string(req->reason_code));
 
 	if (ifmgd->auth_data) {
 		drv_mgd_prepare_tx(sdata->local, sdata);
@@ -4348,8 +4348,8 @@ int ieee80211_mgd_disassoc(struct ieee80211_sub_if_data *sdata,
 		return -ENOLINK;
 
 	sdata_info(sdata,
-		   "disassociating from %pM by local choice (reason=%d)\n",
-		   req->bss->bssid, req->reason_code);
+		   "disassociating from %pM by local choice (Reason: %u=%s)\n",
+		   req->bss->bssid, req->reason_code, ieee80211_get_reason_code_string(req->reason_code));
 
 	memcpy(bssid, req->bss->bssid, ETH_ALEN);
 	ieee80211_set_disassoc(sdata, IEEE80211_STYPE_DISASSOC,
-- 
1.8.5.3