diff options
Diffstat (limited to 'net/wireless/scan.c')
-rw-r--r-- | net/wireless/scan.c | 1033 |
1 files changed, 578 insertions, 455 deletions
diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 9730c9862bdc..674aadca0079 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -17,9 +17,150 @@ #include "core.h" #include "nl80211.h" #include "wext-compat.h" +#include "rdev-ops.h" + +/** + * DOC: BSS tree/list structure + * + * At the top level, the BSS list is kept in both a list in each + * registered device (@bss_list) as well as an RB-tree for faster + * lookup. In the RB-tree, entries can be looked up using their + * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID + * for other BSSes. + * + * Due to the possibility of hidden SSIDs, there's a second level + * structure, the "hidden_list" and "hidden_beacon_bss" pointer. + * The hidden_list connects all BSSes belonging to a single AP + * that has a hidden SSID, and connects beacon and probe response + * entries. For a probe response entry for a hidden SSID, the + * hidden_beacon_bss pointer points to the BSS struct holding the + * beacon's information. + * + * Reference counting is done for all these references except for + * the hidden_list, so that a beacon BSS struct that is otherwise + * not referenced has one reference for being on the bss_list and + * one for each probe response entry that points to it using the + * hidden_beacon_bss pointer. When a BSS struct that has such a + * pointer is get/put, the refcount update is also propagated to + * the referenced struct, this ensure that it cannot get removed + * while somebody is using the probe response version. + * + * Note that the hidden_beacon_bss pointer never changes, due to + * the reference counting. Therefore, no locking is needed for + * it. + * + * Also note that the hidden_beacon_bss pointer is only relevant + * if the driver uses something other than the IEs, e.g. private + * data stored stored in the BSS struct, since the beacon IEs are + * also linked into the probe response struct. + */ #define IEEE80211_SCAN_RESULT_EXPIRE (30 * HZ) +static void bss_free(struct cfg80211_internal_bss *bss) +{ + struct cfg80211_bss_ies *ies; + + if (WARN_ON(atomic_read(&bss->hold))) + return; + + ies = (void *)rcu_access_pointer(bss->pub.beacon_ies); + if (ies && !bss->pub.hidden_beacon_bss) + kfree_rcu(ies, rcu_head); + ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies); + if (ies) + kfree_rcu(ies, rcu_head); + + /* + * This happens when the module is removed, it doesn't + * really matter any more save for completeness + */ + if (!list_empty(&bss->hidden_list)) + list_del(&bss->hidden_list); + + kfree(bss); +} + +static inline void bss_ref_get(struct cfg80211_registered_device *dev, + struct cfg80211_internal_bss *bss) +{ + lockdep_assert_held(&dev->bss_lock); + + bss->refcount++; + if (bss->pub.hidden_beacon_bss) { + bss = container_of(bss->pub.hidden_beacon_bss, + struct cfg80211_internal_bss, + pub); + bss->refcount++; + } +} + +static inline void bss_ref_put(struct cfg80211_registered_device *dev, + struct cfg80211_internal_bss *bss) +{ + lockdep_assert_held(&dev->bss_lock); + + if (bss->pub.hidden_beacon_bss) { + struct cfg80211_internal_bss *hbss; + hbss = container_of(bss->pub.hidden_beacon_bss, + struct cfg80211_internal_bss, + pub); + hbss->refcount--; + if (hbss->refcount == 0) + bss_free(hbss); + } + bss->refcount--; + if (bss->refcount == 0) + bss_free(bss); +} + +static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *dev, + struct cfg80211_internal_bss *bss) +{ + lockdep_assert_held(&dev->bss_lock); + + if (!list_empty(&bss->hidden_list)) { + /* + * don't remove the beacon entry if it has + * probe responses associated with it + */ + if (!bss->pub.hidden_beacon_bss) + return false; + /* + * if it's a probe response entry break its + * link to the other entries in the group + */ + list_del_init(&bss->hidden_list); + } + + list_del_init(&bss->list); + rb_erase(&bss->rbn, &dev->bss_tree); + bss_ref_put(dev, bss); + return true; +} + +static void __cfg80211_bss_expire(struct cfg80211_registered_device *dev, + unsigned long expire_time) +{ + struct cfg80211_internal_bss *bss, *tmp; + bool expired = false; + + lockdep_assert_held(&dev->bss_lock); + + list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) { + if (atomic_read(&bss->hold)) + continue; + if (!time_after(expire_time, bss->ts)) + continue; + + if (__cfg80211_unlink_bss(dev, bss)) + expired = true; + } + + if (expired) + dev->bss_generation++; +} + void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak) { struct cfg80211_scan_request *request; @@ -45,10 +186,17 @@ void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak) if (wdev->netdev) cfg80211_sme_scan_done(wdev->netdev); - if (request->aborted) + if (request->aborted) { nl80211_send_scan_aborted(rdev, wdev); - else + } else { + if (request->flags & NL80211_SCAN_FLAG_FLUSH) { + /* flush entries from previous scans */ + spin_lock_bh(&rdev->bss_lock); + __cfg80211_bss_expire(rdev, request->scan_start); + spin_unlock_bh(&rdev->bss_lock); + } nl80211_send_scan_done(rdev, wdev); + } #ifdef CONFIG_CFG80211_WEXT if (wdev->netdev && !request->aborted) { @@ -89,6 +237,7 @@ void __cfg80211_scan_done(struct work_struct *wk) void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted) { + trace_cfg80211_scan_done(request, aborted); WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req); request->aborted = aborted; @@ -99,22 +248,34 @@ EXPORT_SYMBOL(cfg80211_scan_done); void __cfg80211_sched_scan_results(struct work_struct *wk) { struct cfg80211_registered_device *rdev; + struct cfg80211_sched_scan_request *request; rdev = container_of(wk, struct cfg80211_registered_device, sched_scan_results_wk); + request = rdev->sched_scan_req; + mutex_lock(&rdev->sched_scan_mtx); /* we don't have sched_scan_req anymore if the scan is stopping */ - if (rdev->sched_scan_req) - nl80211_send_sched_scan_results(rdev, - rdev->sched_scan_req->dev); + if (request) { + if (request->flags & NL80211_SCAN_FLAG_FLUSH) { + /* flush entries from previous scans */ + spin_lock_bh(&rdev->bss_lock); + __cfg80211_bss_expire(rdev, request->scan_start); + spin_unlock_bh(&rdev->bss_lock); + request->scan_start = + jiffies + msecs_to_jiffies(request->interval); + } + nl80211_send_sched_scan_results(rdev, request->dev); + } mutex_unlock(&rdev->sched_scan_mtx); } void cfg80211_sched_scan_results(struct wiphy *wiphy) { + trace_cfg80211_sched_scan_results(wiphy); /* ignore if we're not scanning */ if (wiphy_to_dev(wiphy)->sched_scan_req) queue_work(cfg80211_wq, @@ -126,6 +287,8 @@ void cfg80211_sched_scan_stopped(struct wiphy *wiphy) { struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy); + trace_cfg80211_sched_scan_stopped(wiphy); + mutex_lock(&rdev->sched_scan_mtx); __cfg80211_stop_sched_scan(rdev, true); mutex_unlock(&rdev->sched_scan_mtx); @@ -145,7 +308,7 @@ int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev, dev = rdev->sched_scan_req->dev; if (!driver_initiated) { - int err = rdev->ops->sched_scan_stop(&rdev->wiphy, dev); + int err = rdev_sched_scan_stop(rdev, dev); if (err) return err; } @@ -158,62 +321,21 @@ int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev, return 0; } -static void bss_release(struct kref *ref) -{ - struct cfg80211_internal_bss *bss; - - bss = container_of(ref, struct cfg80211_internal_bss, ref); - if (bss->pub.free_priv) - bss->pub.free_priv(&bss->pub); - - 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)); - - kfree(bss); -} - -/* must hold dev->bss_lock! */ void cfg80211_bss_age(struct cfg80211_registered_device *dev, unsigned long age_secs) { struct cfg80211_internal_bss *bss; unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC); - list_for_each_entry(bss, &dev->bss_list, list) { + spin_lock_bh(&dev->bss_lock); + list_for_each_entry(bss, &dev->bss_list, list) bss->ts -= age_jiffies; - } -} - -/* must hold dev->bss_lock! */ -static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev, - struct cfg80211_internal_bss *bss) -{ - list_del_init(&bss->list); - rb_erase(&bss->rbn, &dev->bss_tree); - kref_put(&bss->ref, bss_release); + spin_unlock_bh(&dev->bss_lock); } -/* must hold dev->bss_lock! */ void cfg80211_bss_expire(struct cfg80211_registered_device *dev) { - struct cfg80211_internal_bss *bss, *tmp; - bool expired = false; - - list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) { - if (atomic_read(&bss->hold)) - continue; - if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE)) - continue; - __cfg80211_unlink_bss(dev, bss); - expired = true; - } - - if (expired) - dev->bss_generation++; + __cfg80211_bss_expire(dev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE); } const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len) @@ -243,44 +365,28 @@ const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type, if (!pos) return NULL; - if (end - pos < sizeof(*ie)) - return NULL; - ie = (struct ieee80211_vendor_ie *)pos; + + /* make sure we can access ie->len */ + BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1); + + if (ie->len < sizeof(*ie)) + goto cont; + ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2]; if (ie_oui == oui && ie->oui_type == oui_type) return pos; - +cont: pos += 2 + ie->len; } return NULL; } EXPORT_SYMBOL(cfg80211_find_vendor_ie); -static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t 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, +static bool is_bss(struct cfg80211_bss *a, const u8 *bssid, const u8 *ssid, size_t ssid_len) { + const struct cfg80211_bss_ies *ies; const u8 *ssidie; if (bssid && !ether_addr_equal(a->bssid, bssid)) @@ -289,9 +395,10 @@ static bool is_bss(struct cfg80211_bss *a, if (!ssid) return true; - ssidie = cfg80211_find_ie(WLAN_EID_SSID, - a->information_elements, - a->len_information_elements); + ies = rcu_access_pointer(a->ies); + if (!ies) + return false; + ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); if (!ssidie) return false; if (ssidie[1] != ssid_len) @@ -299,133 +406,83 @@ static bool is_bss(struct cfg80211_bss *a, return memcmp(ssidie + 2, ssid, ssid_len) == 0; } -static bool is_mesh_bss(struct cfg80211_bss *a) -{ - const u8 *ie; - - if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability)) - return false; - - ie = cfg80211_find_ie(WLAN_EID_MESH_ID, - a->information_elements, - a->len_information_elements); - if (!ie) - return false; - - ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, - a->information_elements, - a->len_information_elements); - if (!ie) - return false; - - return true; -} - -static bool is_mesh(struct cfg80211_bss *a, - const u8 *meshid, size_t meshidlen, - const u8 *meshcfg) -{ - const u8 *ie; - - if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability)) - return false; - - ie = cfg80211_find_ie(WLAN_EID_MESH_ID, - a->information_elements, - a->len_information_elements); - if (!ie) - return false; - if (ie[1] != meshidlen) - return false; - if (memcmp(ie + 2, meshid, meshidlen)) - return false; - - 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)) - return false; - - /* - * Ignore mesh capability (last two bytes of the IE) when - * comparing since that may differ between stations taking - * part in the same mesh. - */ - return memcmp(ie + 2, meshcfg, - sizeof(struct ieee80211_meshconf_ie) - 2) == 0; -} +/** + * enum bss_compare_mode - BSS compare mode + * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find) + * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode + * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode + */ +enum bss_compare_mode { + BSS_CMP_REGULAR, + BSS_CMP_HIDE_ZLEN, + BSS_CMP_HIDE_NUL, +}; -static int cmp_bss_core(struct cfg80211_bss *a, - struct cfg80211_bss *b) +static int cmp_bss(struct cfg80211_bss *a, + struct cfg80211_bss *b, + enum bss_compare_mode mode) { - int r; + const struct cfg80211_bss_ies *a_ies, *b_ies; + const u8 *ie1 = NULL; + const u8 *ie2 = NULL; + int i, r; if (a->channel != b->channel) return b->channel->center_freq - a->channel->center_freq; - if (is_mesh_bss(a) && is_mesh_bss(b)) { - r = cmp_ies(WLAN_EID_MESH_ID, - a->information_elements, - a->len_information_elements, - b->information_elements, - b->len_information_elements); - if (r) - return r; - return cmp_ies(WLAN_EID_MESH_CONFIG, - a->information_elements, - a->len_information_elements, - b->information_elements, - b->len_information_elements); + a_ies = rcu_access_pointer(a->ies); + if (!a_ies) + return -1; + b_ies = rcu_access_pointer(b->ies); + 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 */ - return memcmp(a->bssid, b->bssid, sizeof(a->bssid)); -} - -static int cmp_bss(struct cfg80211_bss *a, - struct cfg80211_bss *b) -{ - int r; - - r = cmp_bss_core(a, b); + r = memcmp(a->bssid, b->bssid, sizeof(a->bssid)); if (r) return r; - return cmp_ies(WLAN_EID_SSID, - a->information_elements, - a->len_information_elements, - b->information_elements, - b->len_information_elements); -} - -static int cmp_hidden_bss(struct cfg80211_bss *a, - struct cfg80211_bss *b) -{ - const u8 *ie1; - const u8 *ie2; - int i; - int r; - - r = cmp_bss_core(a, b); - 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); - ie1 = cfg80211_find_ie(WLAN_EID_SSID, - a->information_elements, - a->len_information_elements); - ie2 = cfg80211_find_ie(WLAN_EID_SSID, - b->information_elements, - b->len_information_elements); + if (!ie1 && !ie2) + return 0; - /* 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. */ + /* + * Note that with "hide_ssid", the function returns a match if + * the already-present BSS ("b") is a hidden SSID beacon for + * the new BSS ("a"). + */ /* sort missing IE before (left of) present IE */ if (!ie1) @@ -433,20 +490,36 @@ static int cmp_hidden_bss(struct cfg80211_bss *a, if (!ie2) return 1; - /* zero-size SSID is used as an indication of the hidden bss */ - if (!ie2[1]) + switch (mode) { + case BSS_CMP_HIDE_ZLEN: + /* + * In ZLEN mode we assume the BSS entry we're + * looking for has a zero-length SSID. So if + * the one we're looking at right now has that, + * return 0. Otherwise, return the difference + * in length, but since we're looking for the + * 0-length it's really equivalent to returning + * the length of the one we're looking at. + * + * No content comparison is needed as we assume + * the content length is zero. + */ + return ie2[1]; + case BSS_CMP_REGULAR: + default: + /* 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]); + case BSS_CMP_HIDE_NUL: + if (ie1[1] != ie2[1]) + return ie2[1] - ie1[1]; + /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */ + for (i = 0; i < ie2[1]; i++) + if (ie2[i + 2]) + return -1; return 0; - - /* sort by length first, then by contents */ - if (ie1[1] != ie2[1]) - return ie2[1] - ie1[1]; - - /* zeroed SSID ie is another indication of a hidden bss */ - for (i = 0; i < ie2[1]; i++) - if (ie2[i + 2]) - return -1; - - return 0; + } } struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy, @@ -459,6 +532,9 @@ struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy, struct cfg80211_internal_bss *bss, *res = NULL; unsigned long now = jiffies; + trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, capa_mask, + capa_val); + spin_lock_bh(&dev->bss_lock); list_for_each_entry(bss, &dev->bss_list, list) { @@ -472,7 +548,7 @@ struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy, continue; if (is_bss(&bss->pub, bssid, ssid, ssid_len)) { res = bss; - kref_get(&res->ref); + bss_ref_get(dev, res); break; } } @@ -480,38 +556,11 @@ struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy, spin_unlock_bh(&dev->bss_lock); if (!res) return NULL; + trace_cfg80211_return_bss(&res->pub); return &res->pub; } EXPORT_SYMBOL(cfg80211_get_bss); -struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy, - struct ieee80211_channel *channel, - const u8 *meshid, size_t meshidlen, - const u8 *meshcfg) -{ - struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy); - struct cfg80211_internal_bss *bss, *res = NULL; - - spin_lock_bh(&dev->bss_lock); - - list_for_each_entry(bss, &dev->bss_list, list) { - if (channel && bss->pub.channel != channel) - continue; - if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) { - res = bss; - kref_get(&res->ref); - break; - } - } - - spin_unlock_bh(&dev->bss_lock); - if (!res) - return NULL; - return &res->pub; -} -EXPORT_SYMBOL(cfg80211_get_mesh); - - static void rb_insert_bss(struct cfg80211_registered_device *dev, struct cfg80211_internal_bss *bss) { @@ -524,7 +573,7 @@ static void rb_insert_bss(struct cfg80211_registered_device *dev, parent = *p; tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn); - cmp = cmp_bss(&bss->pub, &tbss->pub); + cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR); if (WARN_ON(!cmp)) { /* will sort of leak this BSS */ @@ -543,7 +592,8 @@ static void rb_insert_bss(struct cfg80211_registered_device *dev, static struct cfg80211_internal_bss * rb_find_bss(struct cfg80211_registered_device *dev, - struct cfg80211_internal_bss *res) + struct cfg80211_internal_bss *res, + enum bss_compare_mode mode) { struct rb_node *n = dev->bss_tree.rb_node; struct cfg80211_internal_bss *bss; @@ -551,7 +601,7 @@ rb_find_bss(struct cfg80211_registered_device *dev, while (n) { bss = rb_entry(n, struct cfg80211_internal_bss, rbn); - r = cmp_bss(&res->pub, &bss->pub); + r = cmp_bss(&res->pub, &bss->pub, mode); if (r == 0) return bss; @@ -564,177 +614,249 @@ rb_find_bss(struct cfg80211_registered_device *dev, return NULL; } -static struct cfg80211_internal_bss * -rb_find_hidden_bss(struct cfg80211_registered_device *dev, - struct cfg80211_internal_bss *res) +static bool cfg80211_combine_bsses(struct cfg80211_registered_device *dev, + struct cfg80211_internal_bss *new) { - struct rb_node *n = dev->bss_tree.rb_node; + const struct cfg80211_bss_ies *ies; struct cfg80211_internal_bss *bss; - int r; + const u8 *ie; + int i, ssidlen; + u8 fold = 0; - while (n) { - bss = rb_entry(n, struct cfg80211_internal_bss, rbn); - r = cmp_hidden_bss(&res->pub, &bss->pub); + ies = rcu_access_pointer(new->pub.beacon_ies); + if (WARN_ON(!ies)) + return false; - if (r == 0) - return bss; - else if (r < 0) - n = n->rb_left; - else - n = n->rb_right; + ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); + if (!ie) { + /* nothing to do */ + return true; } - return NULL; -} + ssidlen = ie[1]; + for (i = 0; i < ssidlen; i++) + fold |= ie[2 + i]; -static void -copy_hidden_ies(struct cfg80211_internal_bss *res, - struct cfg80211_internal_bss *hidden) -{ - if (unlikely(res->pub.beacon_ies)) - return; - if (WARN_ON(!hidden->pub.beacon_ies)) - return; + if (fold) { + /* not a hidden SSID */ + return true; + } - res->pub.beacon_ies = kmalloc(hidden->pub.len_beacon_ies, GFP_ATOMIC); - if (unlikely(!res->pub.beacon_ies)) - return; + /* This is the bad part ... */ + + list_for_each_entry(bss, &dev->bss_list, list) { + if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid)) + continue; + if (bss->pub.channel != new->pub.channel) + continue; + if (rcu_access_pointer(bss->pub.beacon_ies)) + continue; + ies = rcu_access_pointer(bss->pub.ies); + if (!ies) + continue; + ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); + if (!ie) + continue; + if (ssidlen && ie[1] != ssidlen) + continue; + /* that would be odd ... */ + if (bss->pub.beacon_ies) + continue; + if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss)) + continue; + if (WARN_ON_ONCE(!list_empty(&bss->hidden_list))) + list_del(&bss->hidden_list); + /* combine them */ + list_add(&bss->hidden_list, &new->hidden_list); + bss->pub.hidden_beacon_bss = &new->pub; + new->refcount += bss->refcount; + rcu_assign_pointer(bss->pub.beacon_ies, + new->pub.beacon_ies); + } - res->beacon_ies_allocated = true; - res->pub.len_beacon_ies = hidden->pub.len_beacon_ies; - memcpy(res->pub.beacon_ies, hidden->pub.beacon_ies, - res->pub.len_beacon_ies); + return true; } static struct cfg80211_internal_bss * cfg80211_bss_update(struct cfg80211_registered_device *dev, - struct cfg80211_internal_bss *res) + struct cfg80211_internal_bss *tmp) { struct cfg80211_internal_bss *found = NULL; - /* - * The reference to "res" is donated to this function. - */ - - if (WARN_ON(!res->pub.channel)) { - kref_put(&res->ref, bss_release); + if (WARN_ON(!tmp->pub.channel)) return NULL; - } - res->ts = jiffies; + tmp->ts = jiffies; spin_lock_bh(&dev->bss_lock); - found = rb_find_bss(dev, res); + if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) { + spin_unlock_bh(&dev->bss_lock); + return NULL; + } + + found = rb_find_bss(dev, tmp, BSS_CMP_REGULAR); if (found) { - found->pub.beacon_interval = res->pub.beacon_interval; - found->pub.tsf = res->pub.tsf; - found->pub.signal = res->pub.signal; - found->pub.capability = res->pub.capability; - found->ts = res->ts; + found->pub.beacon_interval = tmp->pub.beacon_interval; + found->pub.signal = tmp->pub.signal; + found->pub.capability = tmp->pub.capability; + found->ts = tmp->ts; /* Update IEs */ - if (res->pub.proberesp_ies) { - size_t used = dev->wiphy.bss_priv_size + sizeof(*res); - 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 (rcu_access_pointer(tmp->pub.proberesp_ies)) { + const struct cfg80211_bss_ies *old; + + old = rcu_access_pointer(found->pub.proberesp_ies); + rcu_assign_pointer(found->pub.proberesp_ies, + tmp->pub.proberesp_ies); /* 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; - bool information_elements_is_beacon_ies = - (found->pub.information_elements == - found->pub.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.beacon_ies; - - if (found->beacon_ies_allocated) - ies = krealloc(ies, ielen, GFP_ATOMIC); - else - ies = kmalloc(ielen, GFP_ATOMIC); - - if (ies) { - memcpy(ies, res->pub.beacon_ies, - ielen); - found->beacon_ies_allocated = true; - found->pub.beacon_ies = ies; - found->pub.len_beacon_ies = ielen; - } + rcu_assign_pointer(found->pub.ies, + tmp->pub.proberesp_ies); + if (old) + kfree_rcu((struct cfg80211_bss_ies *)old, + rcu_head); + } else if (rcu_access_pointer(tmp->pub.beacon_ies)) { + const struct cfg80211_bss_ies *old; + struct cfg80211_internal_bss *bss; + + if (found->pub.hidden_beacon_bss && + !list_empty(&found->hidden_list)) { + /* + * The found BSS struct is one of the probe + * response members of a group, but we're + * receiving a beacon (beacon_ies in the tmp + * bss is used). This can only mean that the + * AP changed its beacon from not having an + * SSID to showing it, which is confusing so + * drop this information. + */ + goto drop; } + old = rcu_access_pointer(found->pub.beacon_ies); + + rcu_assign_pointer(found->pub.beacon_ies, + tmp->pub.beacon_ies); + /* Override IEs if they were from a beacon before */ - if (information_elements_is_beacon_ies) { - found->pub.information_elements = - found->pub.beacon_ies; - found->pub.len_information_elements = - found->pub.len_beacon_ies; + if (old == rcu_access_pointer(found->pub.ies)) + rcu_assign_pointer(found->pub.ies, + tmp->pub.beacon_ies); + + /* Assign beacon IEs to all sub entries */ + list_for_each_entry(bss, &found->hidden_list, + hidden_list) { + const struct cfg80211_bss_ies *ies; + + ies = rcu_access_pointer(bss->pub.beacon_ies); + WARN_ON(ies != old); + + rcu_assign_pointer(bss->pub.beacon_ies, + tmp->pub.beacon_ies); } - } - kref_put(&res->ref, bss_release); + if (old) + kfree_rcu((struct cfg80211_bss_ies *)old, + rcu_head); + } } else { + struct cfg80211_internal_bss *new; struct cfg80211_internal_bss *hidden; + struct cfg80211_bss_ies *ies; + + /* + * create a copy -- the "res" variable that is passed in + * is allocated on the stack since it's not needed in the + * more common case of an update + */ + new = kzalloc(sizeof(*new) + dev->wiphy.bss_priv_size, + GFP_ATOMIC); + if (!new) { + ies = (void *)rcu_dereference(tmp->pub.beacon_ies); + if (ies) + kfree_rcu(ies, rcu_head); + ies = (void *)rcu_dereference(tmp->pub.proberesp_ies); + if (ies) + kfree_rcu(ies, rcu_head); + goto drop; + } + memcpy(new, tmp, sizeof(*new)); + new->refcount = 1; + INIT_LIST_HEAD(&new->hidden_list); + + if (rcu_access_pointer(tmp->pub.proberesp_ies)) { + hidden = rb_find_bss(dev, tmp, BSS_CMP_HIDE_ZLEN); + if (!hidden) + hidden = rb_find_bss(dev, tmp, + BSS_CMP_HIDE_NUL); + if (hidden) { + new->pub.hidden_beacon_bss = &hidden->pub; + list_add(&new->hidden_list, + &hidden->hidden_list); + hidden->refcount++; + rcu_assign_pointer(new->pub.beacon_ies, + hidden->pub.beacon_ies); + } + } else { + /* + * Ok so we found a beacon, and don't have an entry. If + * it's a beacon with hidden SSID, we might be in for an + * expensive search for any probe responses that should + * be grouped with this beacon for updates ... + */ + if (!cfg80211_combine_bsses(dev, new)) { + kfree(new); + goto drop; + } + } - /* First check if the beacon is a probe response from - * a hidden bss. If so, copy beacon ies (with nullified - * ssid) into the probe response bss entry (with real ssid). - * It is required basically for PSM implementation - * (probe responses do not contain tim ie) */ - - /* TODO: The code is not trying to update existing probe - * response bss entries when beacon ies are - * getting changed. */ - hidden = rb_find_hidden_bss(dev, res); - if (hidden) - copy_hidden_ies(res, hidden); - - /* this "consumes" the reference */ - list_add_tail(&res->list, &dev->bss_list); - rb_insert_bss(dev, res); - found = res; + list_add_tail(&new->list, &dev->bss_list); + rb_insert_bss(dev, new); + found = new; } dev->bss_generation++; + bss_ref_get(dev, found); spin_unlock_bh(&dev->bss_lock); - kref_get(&found->ref); return found; + drop: + spin_unlock_bh(&dev->bss_lock); + return NULL; +} + +static struct ieee80211_channel * +cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen, + struct ieee80211_channel *channel) +{ + const u8 *tmp; + u32 freq; + int channel_number = -1; + + tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen); + if (tmp && tmp[1] == 1) { + channel_number = tmp[2]; + } else { + tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen); + if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) { + struct ieee80211_ht_operation *htop = (void *)(tmp + 2); + + channel_number = htop->primary_chan; + } + } + + if (channel_number < 0) + return channel; + + freq = ieee80211_channel_to_frequency(channel_number, channel->band); + channel = ieee80211_get_channel(wiphy, freq); + if (!channel) + return NULL; + if (channel->flags & IEEE80211_CHAN_DISABLED) + return NULL; + return channel; } struct cfg80211_bss* @@ -744,54 +866,51 @@ cfg80211_inform_bss(struct wiphy *wiphy, u16 beacon_interval, const u8 *ie, size_t ielen, s32 signal, gfp_t gfp) { - struct cfg80211_internal_bss *res; - size_t privsz; + struct cfg80211_bss_ies *ies; + struct cfg80211_internal_bss tmp = {}, *res; if (WARN_ON(!wiphy)) return NULL; - privsz = wiphy->bss_priv_size; - if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC && (signal < 0 || signal > 100))) return NULL; - res = kzalloc(sizeof(*res) + privsz + ielen, gfp); - if (!res) + channel = cfg80211_get_bss_channel(wiphy, ie, ielen, channel); + if (!channel) return NULL; - memcpy(res->pub.bssid, bssid, ETH_ALEN); - res->pub.channel = channel; - res->pub.signal = signal; - res->pub.tsf = tsf; - res->pub.beacon_interval = beacon_interval; - res->pub.capability = capability; + memcpy(tmp.pub.bssid, bssid, ETH_ALEN); + tmp.pub.channel = channel; + tmp.pub.signal = signal; + tmp.pub.beacon_interval = beacon_interval; + tmp.pub.capability = capability; /* * 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. + * override the IEs pointer should we have received an earlier + * indication of Probe Response data. */ - 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; + ies = kmalloc(sizeof(*ies) + ielen, gfp); + if (!ies) + return NULL; + ies->len = ielen; + ies->tsf = tsf; + memcpy(ies->data, ie, ielen); - kref_init(&res->ref); + rcu_assign_pointer(tmp.pub.beacon_ies, ies); + rcu_assign_pointer(tmp.pub.ies, ies); - res = cfg80211_bss_update(wiphy_to_dev(wiphy), res); + res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp); if (!res) return NULL; if (res->pub.capability & WLAN_CAPABILITY_ESS) regulatory_hint_found_beacon(wiphy, channel, gfp); + trace_cfg80211_return_bss(&res->pub); /* cfg80211_bss_update gives us a referenced result */ return &res->pub; } @@ -803,10 +922,15 @@ cfg80211_inform_bss_frame(struct wiphy *wiphy, struct ieee80211_mgmt *mgmt, size_t len, s32 signal, gfp_t gfp) { - struct cfg80211_internal_bss *res; + struct cfg80211_internal_bss tmp = {}, *res; + struct cfg80211_bss_ies *ies; size_t ielen = len - offsetof(struct ieee80211_mgmt, u.probe_resp.variable); - size_t privsz; + + BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) != + offsetof(struct ieee80211_mgmt, u.beacon.variable)); + + trace_cfg80211_inform_bss_frame(wiphy, channel, mgmt, len, signal); if (WARN_ON(!mgmt)) return NULL; @@ -821,72 +945,72 @@ cfg80211_inform_bss_frame(struct wiphy *wiphy, if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable))) return NULL; - privsz = wiphy->bss_priv_size; - - res = kzalloc(sizeof(*res) + privsz + ielen, gfp); - if (!res) + channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable, + ielen, channel); + if (!channel) return NULL; - memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN); - res->pub.channel = channel; - res->pub.signal = signal; - 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); - /* - * 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); + ies = kmalloc(sizeof(*ies) + ielen, gfp); + if (!ies) + return NULL; + ies->len = ielen; + ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp); + memcpy(ies->data, mgmt->u.probe_resp.variable, ielen); - res = cfg80211_bss_update(wiphy_to_dev(wiphy), res); + if (ieee80211_is_probe_resp(mgmt->frame_control)) + rcu_assign_pointer(tmp.pub.proberesp_ies, ies); + else + rcu_assign_pointer(tmp.pub.beacon_ies, ies); + rcu_assign_pointer(tmp.pub.ies, ies); + + memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN); + tmp.pub.channel = channel; + tmp.pub.signal = signal; + tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int); + tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info); + + res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp); if (!res) return NULL; if (res->pub.capability & WLAN_CAPABILITY_ESS) regulatory_hint_found_beacon(wiphy, channel, gfp); + trace_cfg80211_return_bss(&res->pub); /* cfg80211_bss_update gives us a referenced result */ return &res->pub; } EXPORT_SYMBOL(cfg80211_inform_bss_frame); -void cfg80211_ref_bss(struct cfg80211_bss *pub) +void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) { + struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy); struct cfg80211_internal_bss *bss; if (!pub) return; bss = container_of(pub, struct cfg80211_internal_bss, pub); - kref_get(&bss->ref); + + spin_lock_bh(&dev->bss_lock); + bss_ref_get(dev, bss); + spin_unlock_bh(&dev->bss_lock); } EXPORT_SYMBOL(cfg80211_ref_bss); -void cfg80211_put_bss(struct cfg80211_bss *pub) +void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) { + struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy); struct cfg80211_internal_bss *bss; if (!pub) return; bss = container_of(pub, struct cfg80211_internal_bss, pub); - kref_put(&bss->ref, bss_release); + + spin_lock_bh(&dev->bss_lock); + bss_ref_put(dev, bss); + spin_unlock_bh(&dev->bss_lock); } EXPORT_SYMBOL(cfg80211_put_bss); @@ -902,8 +1026,8 @@ void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) spin_lock_bh(&dev->bss_lock); if (!list_empty(&bss->list)) { - __cfg80211_unlink_bss(dev, bss); - dev->bss_generation++; + if (__cfg80211_unlink_bss(dev, bss)) + dev->bss_generation++; } spin_unlock_bh(&dev->bss_lock); } @@ -962,6 +1086,7 @@ int cfg80211_wext_siwscan(struct net_device *dev, creq->ssids = (void *)&creq->channels[n_channels]; creq->n_channels = n_channels; creq->n_ssids = 1; + creq->scan_start = jiffies; /* translate "Scan on frequencies" request */ i = 0; @@ -1026,7 +1151,7 @@ int cfg80211_wext_siwscan(struct net_device *dev, creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1; rdev->scan_req = creq; - err = rdev->ops->scan(wiphy, creq); + err = rdev_scan(rdev, creq); if (err) { rdev->scan_req = NULL; /* creq will be freed below */ @@ -1044,22 +1169,21 @@ int cfg80211_wext_siwscan(struct net_device *dev, EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan); static void ieee80211_scan_add_ies(struct iw_request_info *info, - struct cfg80211_bss *bss, + const struct cfg80211_bss_ies *ies, char **current_ev, char *end_buf) { - u8 *pos, *end, *next; + const u8 *pos, *end, *next; struct iw_event iwe; - if (!bss->information_elements || - !bss->len_information_elements) + if (!ies) return; /* * If needed, fragment the IEs buffer (at IE boundaries) into short * enough fragments to fit into IW_GENERIC_IE_MAX octet messages. */ - pos = bss->information_elements; - end = pos + bss->len_information_elements; + pos = ies->data; + end = pos + ies->len; while (end - pos > IW_GENERIC_IE_MAX) { next = pos + 2 + pos[1]; @@ -1070,7 +1194,8 @@ static void ieee80211_scan_add_ies(struct iw_request_info *info, iwe.cmd = IWEVGENIE; iwe.u.data.length = next - pos; *current_ev = iwe_stream_add_point(info, *current_ev, - end_buf, &iwe, pos); + end_buf, &iwe, + (void *)pos); pos = next; } @@ -1080,29 +1205,21 @@ static void ieee80211_scan_add_ies(struct iw_request_info *info, iwe.cmd = IWEVGENIE; iwe.u.data.length = end - pos; *current_ev = iwe_stream_add_point(info, *current_ev, - end_buf, &iwe, pos); + end_buf, &iwe, + (void *)pos); } } -static inline unsigned int elapsed_jiffies_msecs(unsigned long start) -{ - unsigned long end = jiffies; - - if (end >= start) - return jiffies_to_msecs(end - start); - - return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1); -} - static char * ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info, struct cfg80211_internal_bss *bss, char *current_ev, char *end_buf) { + const struct cfg80211_bss_ies *ies; struct iw_event iwe; + const u8 *ie; u8 *buf, *cfg, *p; - u8 *ie = bss->pub.information_elements; - int rem = bss->pub.len_information_elements, i, sig; + int rem, i, sig; bool ismesh = false; memset(&iwe, 0, sizeof(iwe)); @@ -1167,6 +1284,11 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info, current_ev = iwe_stream_add_point(info, current_ev, end_buf, &iwe, ""); + rcu_read_lock(); + ies = rcu_dereference(bss->pub.ies); + rem = ies->len; + ie = ies->data; + while (rem >= 2) { /* invalid data */ if (ie[1] > rem - 2) @@ -1179,7 +1301,7 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info, iwe.u.data.length = ie[1]; iwe.u.data.flags = 1; current_ev = iwe_stream_add_point(info, current_ev, end_buf, - &iwe, ie + 2); + &iwe, (u8 *)ie + 2); break; case WLAN_EID_MESH_ID: memset(&iwe, 0, sizeof(iwe)); @@ -1187,7 +1309,7 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info, iwe.u.data.length = ie[1]; iwe.u.data.flags = 1; current_ev = iwe_stream_add_point(info, current_ev, end_buf, - &iwe, ie + 2); + &iwe, (u8 *)ie + 2); break; case WLAN_EID_MESH_CONFIG: ismesh = true; @@ -1196,7 +1318,7 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info, buf = kmalloc(50, GFP_ATOMIC); if (!buf) break; - cfg = ie + 2; + cfg = (u8 *)ie + 2; memset(&iwe, 0, sizeof(iwe)); iwe.cmd = IWEVCUSTOM; sprintf(buf, "Mesh Network Path Selection Protocol ID: " @@ -1276,11 +1398,11 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info, &iwe, IW_EV_UINT_LEN); } - buf = kmalloc(30, GFP_ATOMIC); + buf = kmalloc(31, GFP_ATOMIC); if (buf) { memset(&iwe, 0, sizeof(iwe)); iwe.cmd = IWEVCUSTOM; - sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf)); + sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf)); iwe.u.data.length = strlen(buf); current_ev = iwe_stream_add_point(info, current_ev, end_buf, &iwe, buf); @@ -1294,7 +1416,8 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info, kfree(buf); } - ieee80211_scan_add_ies(info, &bss->pub, ¤t_ev, end_buf); + ieee80211_scan_add_ies(info, ies, ¤t_ev, end_buf); + rcu_read_unlock(); return current_ev; } |