cfg80211: refactor cfg80211_get_ies_channel_number()

Now that this is no longer part of the bigger function,
we can get rid of the channel_num variable. Also change
the function to use the struct element helpers, instead
of open-coding the element handling.

Link: https://lore.kernel.org/r/20211202130913.a0adf67a9319.I6db0340a34fff18d78e9cd512f4abf855da4e43a@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index e502c522965dbd6be746c9d7c439688c3c6daa12..b888522f133b375982b9b54f6f0ebc097ce73560 100644 (file)
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -1796,51 +1796,49 @@ int cfg80211_get_ies_channel_number(const u8 *ie, size_t ielen,
                                    enum nl80211_band band,
                                    enum cfg80211_bss_frame_type ftype)
 {
-       const u8 *tmp;
-       int channel_number = -1;
+       const struct element *tmp;
 
        if (band == NL80211_BAND_6GHZ) {
-               const struct element *elem;
                struct ieee80211_he_operation *he_oper;
 
-               elem = cfg80211_find_ext_elem(WLAN_EID_EXT_HE_OPERATION, ie,
-                                             ielen);
-               if (elem && elem->datalen >= sizeof(*he_oper) &&
-                   elem->datalen >= ieee80211_he_oper_size(&elem->data[1])) {
+               tmp = cfg80211_find_ext_elem(WLAN_EID_EXT_HE_OPERATION, ie,
+                                            ielen);
+               if (tmp && tmp->datalen >= sizeof(*he_oper) &&
+                   tmp->datalen >= ieee80211_he_oper_size(&tmp->data[1])) {
                        const struct ieee80211_he_6ghz_oper *he_6ghz_oper;
 
-                       he_oper = (void *)&elem->data[1];
+                       he_oper = (void *)&tmp->data[1];
 
                        he_6ghz_oper = ieee80211_he_6ghz_oper(he_oper);
                        if (!he_6ghz_oper)
-                               return channel_number;
+                               return -1;
 
                        if (ftype != CFG80211_BSS_FTYPE_BEACON ||
                            he_6ghz_oper->control & IEEE80211_HE_6GHZ_OPER_CTRL_DUP_BEACON)
-                               channel_number = he_6ghz_oper->primary;
+                               return he_6ghz_oper->primary;
                }
        } else if (band == NL80211_BAND_S1GHZ) {
-               tmp = cfg80211_find_ie(WLAN_EID_S1G_OPERATION, ie, ielen);
-               if (tmp && tmp[1] >= sizeof(struct ieee80211_s1g_oper_ie)) {
-                       struct ieee80211_s1g_oper_ie *s1gop = (void *)(tmp + 2);
+               tmp = cfg80211_find_elem(WLAN_EID_S1G_OPERATION, ie, ielen);
+               if (tmp && tmp->datalen >= sizeof(struct ieee80211_s1g_oper_ie)) {
+                       struct ieee80211_s1g_oper_ie *s1gop = (void *)tmp->data;
 
-                       channel_number = s1gop->primary_ch;
+                       return s1gop->primary_ch;
                }
        } else {
-               tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
-               if (tmp && tmp[1] == 1) {
-                       channel_number = tmp[2];
-               } else {
-                       tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
-                       if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
-                               struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
+               tmp = cfg80211_find_elem(WLAN_EID_DS_PARAMS, ie, ielen);
+               if (tmp && tmp->datalen == 1)
+                       return tmp->data[0];
 
-                               channel_number = htop->primary_chan;
-                       }
+               tmp = cfg80211_find_elem(WLAN_EID_HT_OPERATION, ie, ielen);
+               if (tmp &&
+                   tmp->datalen >= sizeof(struct ieee80211_ht_operation)) {
+                       struct ieee80211_ht_operation *htop = (void *)tmp->data;
+
+                       return htop->primary_chan;
                }
        }
 
-       return channel_number;
+       return -1;
 }
 EXPORT_SYMBOL(cfg80211_get_ies_channel_number);