From: Johannes Berg <johannes.berg@xxxxxxxxx> The cmp_bss() comparator function uses memcmp() to compare the SSID. This means that cmp_hidden_bss() needs to similarly return a number bigger than zero (use 1) instead of -1 when ie1 is bigger than ie2, which is the case if an ie2 byte is non-zero. Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> --- net/wireless/scan.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 9233910..834e0d1 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -450,10 +450,16 @@ static int cmp_hidden_bss(struct cfg80211_bss *a, struct cfg80211_bss *b) b->information_elements, b->len_information_elements); - /* Key comparator must use same algorithm in any rb-tree + /* + * Key comparator must use same algorithm in any rb-tree * search function (order is important), otherwise ordering * of items in the tree is broken and search gives incorrect - * results. This code uses same order as cmp_ies() does. */ + * results. This code uses same order as cmp_ies() does. + * + * Note that due to the differring behaviour with hidden SSIDs + * this function only works when "b" is the tree element and + * "a" is the key we're looking for. + */ /* sort missing IE before (left of) present IE */ if (!ie1) @@ -469,10 +475,14 @@ static int cmp_hidden_bss(struct cfg80211_bss *a, struct cfg80211_bss *b) if (ie1[1] != ie2[1]) return ie2[1] - ie1[1]; - /* zeroed SSID ie is another indication of a hidden bss */ + /* + * zeroed SSID ie is another indication of a hidden bss; + * if it isn't zeroed just return the regular sort value + * to find the next candidate + */ for (i = 0; i < ie2[1]; i++) if (ie2[i + 2]) - return -1; + return memcmp(ie1 + 2, ie2 + 2, ie1[1]); return 0; } -- 1.8.0 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
