From 34a6eddbabd704b3c7dae9362234552267573be2 Mon Sep 17 00:00:00 2001 From: Jouni Malinen Date: Wed, 6 Jan 2010 16:19:24 +0200 Subject: cfg80211: Store IEs from both Beacon and Probe Response frames Store information elements from Beacon and Probe Response frames in separate buffers to allow both sets to be made available through nl80211. This allows user space applications to get access to IEs from Beacon frames even if we have received Probe Response frames from the BSS. Previously, the IEs from Probe Response frames would have overridden the IEs from Beacon frames. This feature is of somewhat limited use since most protocols include the same (or extended) information in Probe Response frames. However, there are couple of exceptions where the IEs from Beacon frames could be of some use: TIM IE is only included in Beacon frames (and it would be needed to figure out the DTIM period used in the BSS) and at least some implementations of Wireless Provisioning Services seem to include the full IE only in Beacon frames). The new BSS attribute for scan results is added to allow both the IE sets to be delivered. This is done in a way that maintains the previously used behavior for applications that are not aware of the new NL80211_BSS_BEACON_IES attribute. Signed-off-by: Jouni Malinen Acked-by: Johannes Berg Signed-off-by: John W. Linville --- net/wireless/scan.c | 120 +++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 90 insertions(+), 30 deletions(-) (limited to 'net/wireless/scan.c') diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 0c2cbbebca95..06b0231ee5e3 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -100,8 +100,10 @@ static void bss_release(struct kref *ref) if (bss->pub.free_priv) bss->pub.free_priv(&bss->pub); - if (bss->ies_allocated) - kfree(bss->pub.information_elements); + if (bss->beacon_ies_allocated) + kfree(bss->pub.beacon_ies); + if (bss->proberesp_ies_allocated) + kfree(bss->pub.proberesp_ies); BUG_ON(atomic_read(&bss->hold)); @@ -375,8 +377,7 @@ rb_find_bss(struct cfg80211_registered_device *dev, static struct cfg80211_internal_bss * cfg80211_bss_update(struct cfg80211_registered_device *dev, - struct cfg80211_internal_bss *res, - bool overwrite) + struct cfg80211_internal_bss *res) { struct cfg80211_internal_bss *found = NULL; const u8 *meshid, *meshcfg; @@ -418,28 +419,64 @@ cfg80211_bss_update(struct cfg80211_registered_device *dev, found->pub.capability = res->pub.capability; found->ts = res->ts; - /* overwrite IEs */ - if (overwrite) { + /* Update IEs */ + if (res->pub.proberesp_ies) { size_t used = dev->wiphy.bss_priv_size + sizeof(*res); - size_t ielen = res->pub.len_information_elements; + size_t ielen = res->pub.len_proberesp_ies; + + if (found->pub.proberesp_ies && + !found->proberesp_ies_allocated && + ksize(found) >= used + ielen) { + memcpy(found->pub.proberesp_ies, + res->pub.proberesp_ies, ielen); + found->pub.len_proberesp_ies = ielen; + } else { + u8 *ies = found->pub.proberesp_ies; + + if (found->proberesp_ies_allocated) + ies = krealloc(ies, ielen, GFP_ATOMIC); + else + ies = kmalloc(ielen, GFP_ATOMIC); + + if (ies) { + memcpy(ies, res->pub.proberesp_ies, + ielen); + found->proberesp_ies_allocated = true; + found->pub.proberesp_ies = ies; + found->pub.len_proberesp_ies = ielen; + } + } - if (!found->ies_allocated && ksize(found) >= used + ielen) { - memcpy(found->pub.information_elements, - res->pub.information_elements, ielen); - found->pub.len_information_elements = ielen; + /* Override possible earlier Beacon frame IEs */ + found->pub.information_elements = + found->pub.proberesp_ies; + found->pub.len_information_elements = + found->pub.len_proberesp_ies; + } + if (res->pub.beacon_ies) { + size_t used = dev->wiphy.bss_priv_size + sizeof(*res); + size_t ielen = res->pub.len_beacon_ies; + + if (found->pub.beacon_ies && + !found->beacon_ies_allocated && + ksize(found) >= used + ielen) { + memcpy(found->pub.beacon_ies, + res->pub.beacon_ies, ielen); + found->pub.len_beacon_ies = ielen; } else { - u8 *ies = found->pub.information_elements; + u8 *ies = found->pub.beacon_ies; - if (found->ies_allocated) + if (found->beacon_ies_allocated) ies = krealloc(ies, ielen, GFP_ATOMIC); else ies = kmalloc(ielen, GFP_ATOMIC); if (ies) { - memcpy(ies, res->pub.information_elements, ielen); - found->ies_allocated = true; - found->pub.information_elements = ies; - found->pub.len_information_elements = ielen; + memcpy(ies, res->pub.beacon_ies, + ielen); + found->beacon_ies_allocated = true; + found->pub.beacon_ies = ies; + found->pub.len_beacon_ies = ielen; } } } @@ -489,14 +526,26 @@ cfg80211_inform_bss(struct wiphy *wiphy, res->pub.tsf = timestamp; res->pub.beacon_interval = beacon_interval; res->pub.capability = capability; - /* point to after the private area */ - res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz; - memcpy(res->pub.information_elements, ie, ielen); - res->pub.len_information_elements = ielen; + /* + * Since we do not know here whether the IEs are from a Beacon or Probe + * Response frame, we need to pick one of the options and only use it + * with the driver that does not provide the full Beacon/Probe Response + * frame. Use Beacon frame pointer to avoid indicating that this should + * override the information_elements pointer should we have received an + * earlier indication of Probe Response data. + * + * The initial buffer for the IEs is allocated with the BSS entry and + * is located after the private area. + */ + res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz; + memcpy(res->pub.beacon_ies, ie, ielen); + res->pub.len_beacon_ies = ielen; + res->pub.information_elements = res->pub.beacon_ies; + res->pub.len_information_elements = res->pub.len_beacon_ies; kref_init(&res->ref); - res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0); + res = cfg80211_bss_update(wiphy_to_dev(wiphy), res); if (!res) return NULL; @@ -517,7 +566,6 @@ cfg80211_inform_bss_frame(struct wiphy *wiphy, struct cfg80211_internal_bss *res; size_t ielen = len - offsetof(struct ieee80211_mgmt, u.probe_resp.variable); - bool overwrite; size_t privsz = wiphy->bss_priv_size; if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC && @@ -538,16 +586,28 @@ cfg80211_inform_bss_frame(struct wiphy *wiphy, res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp); res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int); res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info); - /* point to after the private area */ - res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz; - memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen); - res->pub.len_information_elements = ielen; + /* + * The initial buffer for the IEs is allocated with the BSS entry and + * is located after the private area. + */ + if (ieee80211_is_probe_resp(mgmt->frame_control)) { + res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz; + memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable, + ielen); + res->pub.len_proberesp_ies = ielen; + res->pub.information_elements = res->pub.proberesp_ies; + res->pub.len_information_elements = res->pub.len_proberesp_ies; + } else { + res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz; + memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen); + res->pub.len_beacon_ies = ielen; + res->pub.information_elements = res->pub.beacon_ies; + res->pub.len_information_elements = res->pub.len_beacon_ies; + } kref_init(&res->ref); - overwrite = ieee80211_is_probe_resp(mgmt->frame_control); - - res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite); + res = cfg80211_bss_update(wiphy_to_dev(wiphy), res); if (!res) return NULL; -- cgit v1.2.3 From c21dbf9214bce129f92e1af05552553ff0e318ed Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 26 Jan 2010 14:15:46 +0100 Subject: cfg80211: export cfg80211_find_ie This new function (previously a static function called just "find_ie" can be used to find a specific IE in a buffer of IEs. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/wireless/scan.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+), 18 deletions(-) (limited to 'net/wireless/scan.c') diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 06b0231ee5e3..978cac3414b5 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -143,9 +143,9 @@ void cfg80211_bss_expire(struct cfg80211_registered_device *dev) dev->bss_generation++; } -static u8 *find_ie(u8 num, u8 *ies, int len) +const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len) { - while (len > 2 && ies[0] != num) { + while (len > 2 && ies[0] != eid) { len -= ies[1] + 2; ies += ies[1] + 2; } @@ -155,11 +155,12 @@ static u8 *find_ie(u8 num, u8 *ies, int len) return NULL; return ies; } +EXPORT_SYMBOL(cfg80211_find_ie); static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2) { - const u8 *ie1 = find_ie(num, ies1, len1); - const u8 *ie2 = find_ie(num, ies2, len2); + const u8 *ie1 = cfg80211_find_ie(num, ies1, len1); + const u8 *ie2 = cfg80211_find_ie(num, ies2, len2); int r; if (!ie1 && !ie2) @@ -185,9 +186,9 @@ static bool is_bss(struct cfg80211_bss *a, if (!ssid) return true; - ssidie = find_ie(WLAN_EID_SSID, - a->information_elements, - a->len_information_elements); + ssidie = cfg80211_find_ie(WLAN_EID_SSID, + a->information_elements, + a->len_information_elements); if (!ssidie) return false; if (ssidie[1] != ssid_len) @@ -204,9 +205,9 @@ static bool is_mesh(struct cfg80211_bss *a, if (!is_zero_ether_addr(a->bssid)) return false; - ie = find_ie(WLAN_EID_MESH_ID, - a->information_elements, - a->len_information_elements); + ie = cfg80211_find_ie(WLAN_EID_MESH_ID, + a->information_elements, + a->len_information_elements); if (!ie) return false; if (ie[1] != meshidlen) @@ -214,9 +215,9 @@ static bool is_mesh(struct cfg80211_bss *a, if (memcmp(ie + 2, meshid, meshidlen)) return false; - ie = find_ie(WLAN_EID_MESH_CONFIG, - a->information_elements, - a->len_information_elements); + ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, + a->information_elements, + a->len_information_elements); if (!ie) return false; if (ie[1] != sizeof(struct ieee80211_meshconf_ie)) @@ -395,11 +396,12 @@ cfg80211_bss_update(struct cfg80211_registered_device *dev, if (is_zero_ether_addr(res->pub.bssid)) { /* must be mesh, verify */ - meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements, - res->pub.len_information_elements); - meshcfg = find_ie(WLAN_EID_MESH_CONFIG, - res->pub.information_elements, - res->pub.len_information_elements); + meshid = cfg80211_find_ie(WLAN_EID_MESH_ID, + res->pub.information_elements, + res->pub.len_information_elements); + meshcfg = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, + res->pub.information_elements, + res->pub.len_information_elements); if (!meshid || !meshcfg || meshcfg[1] != sizeof(struct ieee80211_meshconf_ie)) { /* bogus mesh */ -- cgit v1.2.3