nl80211: support receiving split frequencies

In order to get more details about each frequency we will need to set
NL80211_ATTR_SPLIT_WIPHY_DUMP in the future. This will result in our
callback being called multiple times. Modify it to support such a
scenario:
1) Start putting new frequencies after the last set one
2) Make sure that attribute is set before iterating it

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Jo-Philipp Wich <jo@mein.io>

diff --git a/iwinfo_nl80211.c b/iwinfo_nl80211.c
index db0fc42efc2be19d4c0e3d0481a31b7bd83db0ee..0f9800bfc7ca87da37d368b6a36f34fabb580520 100644 (file)
--- a/iwinfo_nl80211.c
+++ b/iwinfo_nl80211.c
@@ -2367,37 +2367,44 @@ static int nl80211_get_freqlist_cb(struct nl_msg *msg, void *arg)
        int bands_remain, freqs_remain;
 
        struct nl80211_array_buf *arr = arg;
-       struct iwinfo_freqlist_entry *e = arr->buf;
+       struct iwinfo_freqlist_entry *e;
 
        struct nlattr **attr = nl80211_parse(msg);
        struct nlattr *bands[NL80211_BAND_ATTR_MAX + 1];
        struct nlattr *freqs[NL80211_FREQUENCY_ATTR_MAX + 1];
        struct nlattr *band, *freq;
 
-       nla_for_each_nested(band, attr[NL80211_ATTR_WIPHY_BANDS], bands_remain)
-       {
-               nla_parse(bands, NL80211_BAND_ATTR_MAX,
-                         nla_data(band), nla_len(band), NULL);
+       e = arr->buf;
+       e += arr->count;
 
-               nla_for_each_nested(freq, bands[NL80211_BAND_ATTR_FREQS], freqs_remain)
+       if (attr[NL80211_ATTR_WIPHY_BANDS]) {
+               nla_for_each_nested(band, attr[NL80211_ATTR_WIPHY_BANDS], bands_remain)
                {
-                       nla_parse(freqs, NL80211_FREQUENCY_ATTR_MAX,
-                                 nla_data(freq), nla_len(freq), NULL);
+                       nla_parse(bands, NL80211_BAND_ATTR_MAX,
+                                 nla_data(band), nla_len(band), NULL);
 
-                       if (!freqs[NL80211_FREQUENCY_ATTR_FREQ] ||
-                           freqs[NL80211_FREQUENCY_ATTR_DISABLED])
-                               continue;
+                       if (bands[NL80211_BAND_ATTR_FREQS]) {
+                               nla_for_each_nested(freq, bands[NL80211_BAND_ATTR_FREQS], freqs_remain)
+                               {
+                                       nla_parse(freqs, NL80211_FREQUENCY_ATTR_MAX,
+                                                 nla_data(freq), nla_len(freq), NULL);
 
-                       e->mhz = nla_get_u32(freqs[NL80211_FREQUENCY_ATTR_FREQ]);
-                       e->channel = nl80211_freq2channel(e->mhz);
+                                       if (!freqs[NL80211_FREQUENCY_ATTR_FREQ] ||
+                                           freqs[NL80211_FREQUENCY_ATTR_DISABLED])
+                                               continue;
 
-                       e->restricted = (
-                               freqs[NL80211_FREQUENCY_ATTR_NO_IR] &&
-                               !freqs[NL80211_FREQUENCY_ATTR_RADAR]
-                       ) ? 1 : 0;
+                                       e->mhz = nla_get_u32(freqs[NL80211_FREQUENCY_ATTR_FREQ]);
+                                       e->channel = nl80211_freq2channel(e->mhz);
 
-                       e++;
-                       arr->count++;
+                                       e->restricted = (
+                                               freqs[NL80211_FREQUENCY_ATTR_NO_IR] &&
+                                               !freqs[NL80211_FREQUENCY_ATTR_RADAR]
+                                       ) ? 1 : 0;
+
+                                       e++;
+                                       arr->count++;
+                               }
+                       }
                }
        }