diff options
Diffstat (limited to 'net/wireless/scan.c')
-rw-r--r-- | net/wireless/scan.c | 287 |
1 files changed, 176 insertions, 111 deletions
diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 6bb9437af28b..a1c53d4b6711 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -104,18 +104,12 @@ static inline void bss_ref_get(struct cfg80211_registered_device *rdev, lockdep_assert_held(&rdev->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++; - } - if (bss->pub.transmitted_bss) { - bss = container_of(bss->pub.transmitted_bss, - struct cfg80211_internal_bss, - pub); - bss->refcount++; - } + + if (bss->pub.hidden_beacon_bss) + bss_from_pub(bss->pub.hidden_beacon_bss)->refcount++; + + if (bss->pub.transmitted_bss) + bss_from_pub(bss->pub.transmitted_bss)->refcount++; } static inline void bss_ref_put(struct cfg80211_registered_device *rdev, @@ -229,114 +223,152 @@ bool cfg80211_is_element_inherited(const struct element *elem, } EXPORT_SYMBOL(cfg80211_is_element_inherited); -static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen, - const u8 *subelement, size_t subie_len, - u8 *new_ie, gfp_t gfp) +static size_t cfg80211_copy_elem_with_frags(const struct element *elem, + const u8 *ie, size_t ie_len, + u8 **pos, u8 *buf, size_t buf_len) { - u8 *pos, *tmp; - const u8 *tmp_old, *tmp_new; - const struct element *non_inherit_elem; - u8 *sub_copy; + if (WARN_ON((u8 *)elem < ie || elem->data > ie + ie_len || + elem->data + elem->datalen > ie + ie_len)) + return 0; - /* copy subelement as we need to change its content to - * mark an ie after it is processed. - */ - sub_copy = kmemdup(subelement, subie_len, gfp); - if (!sub_copy) + if (elem->datalen + 2 > buf + buf_len - *pos) return 0; - pos = &new_ie[0]; + memcpy(*pos, elem, elem->datalen + 2); + *pos += elem->datalen + 2; - /* set new ssid */ - tmp_new = cfg80211_find_ie(WLAN_EID_SSID, sub_copy, subie_len); - if (tmp_new) { - memcpy(pos, tmp_new, tmp_new[1] + 2); - pos += (tmp_new[1] + 2); + /* Finish if it is not fragmented */ + if (elem->datalen != 255) + return *pos - buf; + + ie_len = ie + ie_len - elem->data - elem->datalen; + ie = (const u8 *)elem->data + elem->datalen; + + for_each_element(elem, ie, ie_len) { + if (elem->id != WLAN_EID_FRAGMENT) + break; + + if (elem->datalen + 2 > buf + buf_len - *pos) + return 0; + + memcpy(*pos, elem, elem->datalen + 2); + *pos += elem->datalen + 2; + + if (elem->datalen != 255) + break; } - /* get non inheritance list if exists */ - non_inherit_elem = - cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE, - sub_copy, subie_len); + return *pos - buf; +} - /* go through IEs in ie (skip SSID) and subelement, - * merge them into new_ie +static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen, + const u8 *subie, size_t subie_len, + u8 *new_ie, size_t new_ie_len) +{ + const struct element *non_inherit_elem, *parent, *sub; + u8 *pos = new_ie; + u8 id, ext_id; + unsigned int match_len; + + non_inherit_elem = cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE, + subie, subie_len); + + /* We copy the elements one by one from the parent to the generated + * elements. + * If they are not inherited (included in subie or in the non + * inheritance element), then we copy all occurrences the first time + * we see this element type. */ - tmp_old = cfg80211_find_ie(WLAN_EID_SSID, ie, ielen); - tmp_old = (tmp_old) ? tmp_old + tmp_old[1] + 2 : ie; - - while (tmp_old + tmp_old[1] + 2 - ie <= ielen) { - if (tmp_old[0] == 0) { - tmp_old++; + for_each_element(parent, ie, ielen) { + if (parent->id == WLAN_EID_FRAGMENT) continue; + + if (parent->id == WLAN_EID_EXTENSION) { + if (parent->datalen < 1) + continue; + + id = WLAN_EID_EXTENSION; + ext_id = parent->data[0]; + match_len = 1; + } else { + id = parent->id; + match_len = 0; } - if (tmp_old[0] == WLAN_EID_EXTENSION) - tmp = (u8 *)cfg80211_find_ext_ie(tmp_old[2], sub_copy, - subie_len); - else - tmp = (u8 *)cfg80211_find_ie(tmp_old[0], sub_copy, - subie_len); + /* Find first occurrence in subie */ + sub = cfg80211_find_elem_match(id, subie, subie_len, + &ext_id, match_len, 0); - if (!tmp) { - const struct element *old_elem = (void *)tmp_old; + /* Copy from parent if not in subie and inherited */ + if (!sub && + cfg80211_is_element_inherited(parent, non_inherit_elem)) { + if (!cfg80211_copy_elem_with_frags(parent, + ie, ielen, + &pos, new_ie, + new_ie_len)) + return 0; - /* ie in old ie but not in subelement */ - if (cfg80211_is_element_inherited(old_elem, - non_inherit_elem)) { - memcpy(pos, tmp_old, tmp_old[1] + 2); - pos += tmp_old[1] + 2; - } - } else { - /* ie in transmitting ie also in subelement, - * copy from subelement and flag the ie in subelement - * as copied (by setting eid field to WLAN_EID_SSID, - * which is skipped anyway). - * For vendor ie, compare OUI + type + subType to - * determine if they are the same ie. - */ - if (tmp_old[0] == WLAN_EID_VENDOR_SPECIFIC) { - if (!memcmp(tmp_old + 2, tmp + 2, 5)) { - /* same vendor ie, copy from - * subelement - */ - memcpy(pos, tmp, tmp[1] + 2); - pos += tmp[1] + 2; - tmp[0] = WLAN_EID_SSID; - } else { - memcpy(pos, tmp_old, tmp_old[1] + 2); - pos += tmp_old[1] + 2; - } - } else { - /* copy ie from subelement into new ie */ - memcpy(pos, tmp, tmp[1] + 2); - pos += tmp[1] + 2; - tmp[0] = WLAN_EID_SSID; - } + continue; } - if (tmp_old + tmp_old[1] + 2 - ie == ielen) - break; + /* Already copied if an earlier element had the same type */ + if (cfg80211_find_elem_match(id, ie, (u8 *)parent - ie, + &ext_id, match_len, 0)) + continue; - tmp_old += tmp_old[1] + 2; + /* Not inheriting, copy all similar elements from subie */ + while (sub) { + if (!cfg80211_copy_elem_with_frags(sub, + subie, subie_len, + &pos, new_ie, + new_ie_len)) + return 0; + + sub = cfg80211_find_elem_match(id, + sub->data + sub->datalen, + subie_len + subie - + (sub->data + + sub->datalen), + &ext_id, match_len, 0); + } } - /* go through subelement again to check if there is any ie not - * copied to new ie, skip ssid, capability, bssid-index ie + /* The above misses elements that are included in subie but not in the + * parent, so do a pass over subie and append those. + * Skip the non-tx BSSID caps and non-inheritance element. */ - tmp_new = sub_copy; - while (tmp_new + tmp_new[1] + 2 - sub_copy <= subie_len) { - if (!(tmp_new[0] == WLAN_EID_NON_TX_BSSID_CAP || - tmp_new[0] == WLAN_EID_SSID)) { - memcpy(pos, tmp_new, tmp_new[1] + 2); - pos += tmp_new[1] + 2; + for_each_element(sub, subie, subie_len) { + if (sub->id == WLAN_EID_NON_TX_BSSID_CAP) + continue; + + if (sub->id == WLAN_EID_FRAGMENT) + continue; + + if (sub->id == WLAN_EID_EXTENSION) { + if (sub->datalen < 1) + continue; + + id = WLAN_EID_EXTENSION; + ext_id = sub->data[0]; + match_len = 1; + + if (ext_id == WLAN_EID_EXT_NON_INHERITANCE) + continue; + } else { + id = sub->id; + match_len = 0; } - if (tmp_new + tmp_new[1] + 2 - sub_copy == subie_len) - break; - tmp_new += tmp_new[1] + 2; + + /* Processed if one was included in the parent */ + if (cfg80211_find_elem_match(id, ie, ielen, + &ext_id, match_len, 0)) + continue; + + if (!cfg80211_copy_elem_with_frags(sub, subie, subie_len, + &pos, new_ie, new_ie_len)) + return 0; } - kfree(sub_copy); return pos - new_ie; } @@ -390,6 +422,15 @@ cfg80211_add_nontrans_list(struct cfg80211_bss *trans_bss, rcu_read_unlock(); + /* + * This is a bit weird - it's not on the list, but already on another + * one! The only way that could happen is if there's some BSSID/SSID + * shared by multiple APs in their multi-BSSID profiles, potentially + * with hidden SSID mixed in ... ignore it. + */ + if (!list_empty(&nontrans_bss->nontrans_list)) + return -EINVAL; + /* add to the list */ list_add_tail(&nontrans_bss->nontrans_list, &trans_bss->nontrans_list); return 0; @@ -1094,6 +1135,23 @@ struct cfg80211_non_tx_bss { u8 bssid_index; }; +static void cfg80211_update_hidden_bsses(struct cfg80211_internal_bss *known, + const struct cfg80211_bss_ies *new_ies, + const struct cfg80211_bss_ies *old_ies) +{ + struct cfg80211_internal_bss *bss; + + /* Assign beacon IEs to all sub entries */ + list_for_each_entry(bss, &known->hidden_list, hidden_list) { + const struct cfg80211_bss_ies *ies; + + ies = rcu_access_pointer(bss->pub.beacon_ies); + WARN_ON(ies != old_ies); + + rcu_assign_pointer(bss->pub.beacon_ies, new_ies); + } +} + static bool cfg80211_update_known_bss(struct cfg80211_registered_device *rdev, struct cfg80211_internal_bss *known, @@ -1117,7 +1175,6 @@ cfg80211_update_known_bss(struct cfg80211_registered_device *rdev, kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); } else if (rcu_access_pointer(new->pub.beacon_ies)) { const struct cfg80211_bss_ies *old; - struct cfg80211_internal_bss *bss; if (known->pub.hidden_beacon_bss && !list_empty(&known->hidden_list)) { @@ -1145,16 +1202,9 @@ cfg80211_update_known_bss(struct cfg80211_registered_device *rdev, if (old == rcu_access_pointer(known->pub.ies)) rcu_assign_pointer(known->pub.ies, new->pub.beacon_ies); - /* Assign beacon IEs to all sub entries */ - list_for_each_entry(bss, &known->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, - new->pub.beacon_ies); - } + cfg80211_update_hidden_bsses(known, + rcu_access_pointer(new->pub.beacon_ies), + old); if (old) kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); @@ -1231,6 +1281,8 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev, new->refcount = 1; INIT_LIST_HEAD(&new->hidden_list); INIT_LIST_HEAD(&new->pub.nontrans_list); + /* we'll set this later if it was non-NULL */ + new->pub.transmitted_bss = NULL; if (rcu_access_pointer(tmp->pub.proberesp_ies)) { hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN); @@ -1242,8 +1294,12 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev, list_add(&new->hidden_list, &hidden->hidden_list); hidden->refcount++; + + ies = (void *)rcu_access_pointer(new->pub.beacon_ies); rcu_assign_pointer(new->pub.beacon_ies, hidden->pub.beacon_ies); + if (ies) + kfree_rcu(ies, rcu_head); } } else { /* @@ -1460,10 +1516,15 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy, spin_lock_bh(&rdev->bss_lock); if (cfg80211_add_nontrans_list(non_tx_data->tx_bss, &res->pub)) { - if (__cfg80211_unlink_bss(rdev, res)) + if (__cfg80211_unlink_bss(rdev, res)) { rdev->bss_generation++; + res = NULL; + } } spin_unlock_bh(&rdev->bss_lock); + + if (!res) + return NULL; } trace_cfg80211_return_bss(&res->pub); @@ -1582,6 +1643,8 @@ static void cfg80211_parse_mbssid_data(struct wiphy *wiphy, for_each_element_id(elem, WLAN_EID_MULTIPLE_BSSID, ie, ielen) { if (elem->datalen < 4) continue; + if (elem->data[0] < 1 || (int)elem->data[0] > 8) + continue; for_each_element(sub, elem->data + 1, elem->datalen - 1) { u8 profile_len; @@ -1635,7 +1698,7 @@ static void cfg80211_parse_mbssid_data(struct wiphy *wiphy, new_ie_len = cfg80211_gen_new_ie(ie, ielen, profile, profile_len, new_ie, - gfp); + IEEE80211_MAX_DATA_LEN); if (!new_ie_len) continue; @@ -1717,7 +1780,7 @@ cfg80211_update_notlisted_nontrans(struct wiphy *wiphy, size_t new_ie_len; struct cfg80211_bss_ies *new_ies; const struct cfg80211_bss_ies *old; - u8 cpy_len; + size_t cpy_len; lockdep_assert_held(&wiphy_to_rdev(wiphy)->bss_lock); @@ -1784,6 +1847,8 @@ cfg80211_update_notlisted_nontrans(struct wiphy *wiphy, } else { old = rcu_access_pointer(nontrans_bss->beacon_ies); rcu_assign_pointer(nontrans_bss->beacon_ies, new_ies); + cfg80211_update_hidden_bsses(bss_from_pub(nontrans_bss), + new_ies, old); rcu_assign_pointer(nontrans_bss->ies, new_ies); if (old) kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); |