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Commit 3af6341c authored by Johannes Berg's avatar Johannes Berg
Browse files

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: default avatarJohannes Berg <johannes.berg@intel.com>
parent 4593c4cb

net/wireless/scan.c

+39 −81
Original line number Diff line number Diff line
@@ -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);