From 3af6341c5378d1ed0905614575ee9ee2e5522c81 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 30 Jan 2013 00:40:20 +0100 Subject: [PATCH] cfg80211: simplify mesh BSS comparison Instead of first checking if a BSS is an MBSS and then doing the comparisons, inline it all into the BSS comparison function. This avoids doing the IE searches twice and is also a lot less code. Signed-off-by: Johannes Berg --- net/wireless/scan.c | 120 ++++++++++++++------------------------------ 1 file changed, 39 insertions(+), 81 deletions(-) diff --git a/net/wireless/scan.c b/net/wireless/scan.c index d4fe065eeb11..1435b97b1ca2 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -288,26 +288,6 @@ const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type, } EXPORT_SYMBOL(cfg80211_find_vendor_ie); -static int cmp_ies(u8 num, const u8 *ies1, int len1, const u8 *ies2, int len2) -{ - const u8 *ie1 = cfg80211_find_ie(num, ies1, len1); - const u8 *ie2 = cfg80211_find_ie(num, ies2, len2); - - /* equal if both missing */ - if (!ie1 && !ie2) - return 0; - /* sort missing IE before (left of) present IE */ - if (!ie1) - return -1; - if (!ie2) - return 1; - - /* sort by length first, then by contents */ - if (ie1[1] != ie2[1]) - return ie2[1] - ie1[1]; - return memcmp(ie1 + 2, ie2 + 2, ie1[1]); -} - static bool is_bss(struct cfg80211_bss *a, const u8 *bssid, const u8 *ssid, size_t ssid_len) { @@ -331,29 +311,6 @@ static bool is_bss(struct cfg80211_bss *a, const u8 *bssid, return memcmp(ssidie + 2, ssid, ssid_len) == 0; } -static bool is_mesh_bss(struct cfg80211_bss *a) -{ - const struct cfg80211_bss_ies *ies; - const u8 *ie; - - if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability)) - return false; - - ies = rcu_access_pointer(a->ies); - if (!ies) - return false; - - ie = cfg80211_find_ie(WLAN_EID_MESH_ID, ies->data, ies->len); - if (!ie) - return false; - - ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, ies->data, ies->len); - if (!ie) - return false; - - return true; -} - static bool is_mesh(struct cfg80211_bss *a, const u8 *meshid, size_t meshidlen, const u8 *meshcfg) @@ -391,39 +348,6 @@ static bool is_mesh(struct cfg80211_bss *a, sizeof(struct ieee80211_meshconf_ie) - 2) == 0; } -static int cmp_bss_core(struct cfg80211_bss *a, struct cfg80211_bss *b) -{ - const struct cfg80211_bss_ies *a_ies, *b_ies; - int r; - - if (a->channel != b->channel) - return b->channel->center_freq - a->channel->center_freq; - - if (is_mesh_bss(a) && is_mesh_bss(b)) { - a_ies = rcu_access_pointer(a->ies); - if (!a_ies) - return -1; - b_ies = rcu_access_pointer(b->ies); - if (!b_ies) - return 1; - - r = cmp_ies(WLAN_EID_MESH_ID, - a_ies->data, a_ies->len, - b_ies->data, b_ies->len); - if (r) - return r; - return cmp_ies(WLAN_EID_MESH_CONFIG, - a_ies->data, a_ies->len, - b_ies->data, b_ies->len); - } - - /* - * we can't use compare_ether_addr here since we need a < > operator. - * The binary return value of compare_ether_addr isn't enough - */ - return memcmp(a->bssid, b->bssid, sizeof(a->bssid)); -} - /** * enum bss_compare_mode - BSS compare mode * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find) @@ -441,13 +365,12 @@ static int cmp_bss(struct cfg80211_bss *a, enum bss_compare_mode mode) { const struct cfg80211_bss_ies *a_ies, *b_ies; - const u8 *ie1; - const u8 *ie2; + const u8 *ie1 = NULL; + const u8 *ie2 = NULL; int i, r; - r = cmp_bss_core(a, b); - if (r) - return r; + if (a->channel != b->channel) + return b->channel->center_freq - a->channel->center_freq; a_ies = rcu_access_pointer(a->ies); if (!a_ies) @@ -456,6 +379,41 @@ static int cmp_bss(struct cfg80211_bss *a, if (!b_ies) return 1; + if (WLAN_CAPABILITY_IS_STA_BSS(a->capability)) + ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID, + a_ies->data, a_ies->len); + if (WLAN_CAPABILITY_IS_STA_BSS(b->capability)) + ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID, + b_ies->data, b_ies->len); + if (ie1 && ie2) { + int mesh_id_cmp; + + if (ie1[1] == ie2[1]) + mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]); + else + mesh_id_cmp = ie2[1] - ie1[1]; + + ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, + a_ies->data, a_ies->len); + ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, + b_ies->data, b_ies->len); + if (ie1 && ie2) { + if (mesh_id_cmp) + return mesh_id_cmp; + if (ie1[1] != ie2[1]) + return ie2[1] - ie1[1]; + return memcmp(ie1 + 2, ie2 + 2, ie1[1]); + } + } + + /* + * we can't use compare_ether_addr here since we need a < > operator. + * The binary return value of compare_ether_addr isn't enough + */ + r = memcmp(a->bssid, b->bssid, sizeof(a->bssid)); + if (r) + return r; + ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len); ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);