diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h index 281a2bb6a6ec..0ea497cb607c 100644 --- a/include/linux/nl80211.h +++ b/include/linux/nl80211.h @@ -76,6 +76,39 @@ * below. */ +/** + * DOC: Virtual interface / concurrency capabilities + * + * Some devices are able to operate with virtual MACs, they can have + * more than one virtual interface. The capability handling for this + * is a bit complex though, as there may be a number of restrictions + * on the types of concurrency that are supported. + * + * To start with, each device supports the interface types listed in + * the %NL80211_ATTR_SUPPORTED_IFTYPES attribute, but by listing the + * types there no concurrency is implied. + * + * Once concurrency is desired, more attributes must be observed: + * To start with, since some interface types are purely managed in + * software, like the AP-VLAN type in mac80211 for example, there's + * an additional list of these, they can be added at any time and + * are only restricted by some semantic restrictions (e.g. AP-VLAN + * cannot be added without a corresponding AP interface). This list + * is exported in the %NL80211_ATTR_SOFTWARE_IFTYPES attribute. + * + * Further, the list of supported combinations is exported. This is + * in the %NL80211_ATTR_INTERFACE_COMBINATIONS attribute. Basically, + * it exports a list of "groups", and at any point in time the + * interfaces that are currently active must fall into any one of + * the advertised groups. Within each group, there are restrictions + * on the number of interfaces of different types that are supported + * and also the number of different channels, along with potentially + * some other restrictions. See &enum nl80211_if_combination_attrs. + * + * All together, these attributes define the concurrency of virtual + * interfaces that a given device supports. + */ + /** * enum nl80211_commands - supported nl80211 commands * @@ -954,6 +987,14 @@ enum nl80211_commands { * @NL80211_ATTR_SCHED_SCAN_INTERVAL: Interval between scheduled scan * cycles, in msecs. * + * @NL80211_ATTR_INTERFACE_COMBINATIONS: Nested attribute listing the supported + * interface combinations. In each nested item, it contains attributes + * defined in &enum nl80211_if_combination_attrs. + * @NL80211_ATTR_SOFTWARE_IFTYPES: Nested attribute (just like + * %NL80211_ATTR_SUPPORTED_IFTYPES) containing the interface types that + * are managed in software: interfaces of these types aren't subject to + * any restrictions in their number or combinations. + * * @NL80211_ATTR_MAX: highest attribute number currently defined * @__NL80211_ATTR_AFTER_LAST: internal use */ @@ -1149,6 +1190,9 @@ enum nl80211_attrs { NL80211_ATTR_SCHED_SCAN_INTERVAL, + NL80211_ATTR_INTERFACE_COMBINATIONS, + NL80211_ATTR_SOFTWARE_IFTYPES, + /* add attributes here, update the policy in nl80211.c */ __NL80211_ATTR_AFTER_LAST, @@ -1201,7 +1245,9 @@ enum nl80211_attrs { * @NL80211_IFTYPE_ADHOC: independent BSS member * @NL80211_IFTYPE_STATION: managed BSS member * @NL80211_IFTYPE_AP: access point - * @NL80211_IFTYPE_AP_VLAN: VLAN interface for access points + * @NL80211_IFTYPE_AP_VLAN: VLAN interface for access points; VLAN interfaces + * are a bit special in that they must always be tied to a pre-existing + * AP type interface. * @NL80211_IFTYPE_WDS: wireless distribution interface * @NL80211_IFTYPE_MONITOR: monitor interface receiving all frames * @NL80211_IFTYPE_MESH_POINT: mesh point @@ -2206,4 +2252,78 @@ enum nl80211_wowlan_triggers { MAX_NL80211_WOWLAN_TRIG = NUM_NL80211_WOWLAN_TRIG - 1 }; +/** + * enum nl80211_iface_limit_attrs - limit attributes + * @NL80211_IFACE_LIMIT_UNSPEC: (reserved) + * @NL80211_IFACE_LIMIT_MAX: maximum number of interfaces that + * can be chosen from this set of interface types (u32) + * @NL80211_IFACE_LIMIT_TYPES: nested attribute containing a + * flag attribute for each interface type in this set + * @NUM_NL80211_IFACE_LIMIT: number of attributes + * @MAX_NL80211_IFACE_LIMIT: highest attribute number + */ +enum nl80211_iface_limit_attrs { + NL80211_IFACE_LIMIT_UNSPEC, + NL80211_IFACE_LIMIT_MAX, + NL80211_IFACE_LIMIT_TYPES, + + /* keep last */ + NUM_NL80211_IFACE_LIMIT, + MAX_NL80211_IFACE_LIMIT = NUM_NL80211_IFACE_LIMIT - 1 +}; + +/** + * enum nl80211_if_combination_attrs -- interface combination attributes + * + * @NL80211_IFACE_COMB_UNSPEC: (reserved) + * @NL80211_IFACE_COMB_LIMITS: Nested attributes containing the limits + * for given interface types, see &enum nl80211_iface_limit_attrs. + * @NL80211_IFACE_COMB_MAXNUM: u32 attribute giving the total number of + * interfaces that can be created in this group. This number doesn't + * apply to interfaces purely managed in software, which are listed + * in a separate attribute %NL80211_ATTR_INTERFACES_SOFTWARE. + * @NL80211_IFACE_COMB_STA_AP_BI_MATCH: flag attribute specifying that + * beacon intervals within this group must be all the same even for + * infrastructure and AP/GO combinations, i.e. the GO(s) must adopt + * the infrastructure network's beacon interval. + * @NL80211_IFACE_COMB_NUM_CHANNELS: u32 attribute specifying how many + * different channels may be used within this group. + * @NUM_NL80211_IFACE_COMB: number of attributes + * @MAX_NL80211_IFACE_COMB: highest attribute number + * + * Examples: + * limits = [ #{STA} <= 1, #{AP} <= 1 ], matching BI, channels = 1, max = 2 + * => allows an AP and a STA that must match BIs + * + * numbers = [ #{AP, P2P-GO} <= 8 ], channels = 1, max = 8 + * => allows 8 of AP/GO + * + * numbers = [ #{STA} <= 2 ], channels = 2, max = 2 + * => allows two STAs on different channels + * + * numbers = [ #{STA} <= 1, #{P2P-client,P2P-GO} <= 3 ], max = 4 + * => allows a STA plus three P2P interfaces + * + * The list of these four possiblities could completely be contained + * within the %NL80211_ATTR_INTERFACE_COMBINATIONS attribute to indicate + * that any of these groups must match. + * + * "Combinations" of just a single interface will not be listed here, + * a single interface of any valid interface type is assumed to always + * be possible by itself. This means that implicitly, for each valid + * interface type, the following group always exists: + * numbers = [ #{} <= 1 ], channels = 1, max = 1 + */ +enum nl80211_if_combination_attrs { + NL80211_IFACE_COMB_UNSPEC, + NL80211_IFACE_COMB_LIMITS, + NL80211_IFACE_COMB_MAXNUM, + NL80211_IFACE_COMB_STA_AP_BI_MATCH, + NL80211_IFACE_COMB_NUM_CHANNELS, + + /* keep last */ + NUM_NL80211_IFACE_COMB, + MAX_NL80211_IFACE_COMB = NUM_NL80211_IFACE_COMB - 1 +}; + #endif /* __LINUX_NL80211_H */ diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index e1f1b41f7b13..04afcfb9eaf4 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -1547,6 +1547,10 @@ struct cfg80211_ops { * hints read the documenation for regulatory_hint_found_beacon() * @WIPHY_FLAG_NETNS_OK: if not set, do not allow changing the netns of this * wiphy at all + * @WIPHY_FLAG_ENFORCE_COMBINATIONS: Set this flag to enforce interface + * combinations for this device. This flag is used for backward + * compatibility only until all drivers advertise combinations and + * they will always be enforced. * @WIPHY_FLAG_PS_ON_BY_DEFAULT: if set to true, powersave will be enabled * by default -- this flag will be set depending on the kernel's default * on wiphy_new(), but can be changed by the driver if it has a good @@ -1574,6 +1578,81 @@ enum wiphy_flags { WIPHY_FLAG_IBSS_RSN = BIT(8), WIPHY_FLAG_MESH_AUTH = BIT(10), WIPHY_FLAG_SUPPORTS_SCHED_SCAN = BIT(11), + WIPHY_FLAG_ENFORCE_COMBINATIONS = BIT(12), +}; + +/** + * struct ieee80211_iface_limit - limit on certain interface types + * @max: maximum number of interfaces of these types + * @types: interface types (bits) + */ +struct ieee80211_iface_limit { + u16 max; + u16 types; +}; + +/** + * struct ieee80211_iface_combination - possible interface combination + * @limits: limits for the given interface types + * @n_limits: number of limitations + * @num_different_channels: can use up to this many different channels + * @max_interfaces: maximum number of interfaces in total allowed in this + * group + * @beacon_int_infra_match: In this combination, the beacon intervals + * between infrastructure and AP types must match. This is required + * only in special cases. + * + * These examples can be expressed as follows: + * + * Allow #STA <= 1, #AP <= 1, matching BI, channels = 1, 2 total: + * + * struct ieee80211_iface_limit limits1[] = { + * { .max = 1, .types = BIT(NL80211_IFTYPE_STATION), }, + * { .max = 1, .types = BIT(NL80211_IFTYPE_AP}, }, + * }; + * struct ieee80211_iface_combination combination1 = { + * .limits = limits1, + * .n_limits = ARRAY_SIZE(limits1), + * .max_interfaces = 2, + * .beacon_int_infra_match = true, + * }; + * + * + * Allow #{AP, P2P-GO} <= 8, channels = 1, 8 total: + * + * struct ieee80211_iface_limit limits2[] = { + * { .max = 8, .types = BIT(NL80211_IFTYPE_AP) | + * BIT(NL80211_IFTYPE_P2P_GO), }, + * }; + * struct ieee80211_iface_combination combination2 = { + * .limits = limits2, + * .n_limits = ARRAY_SIZE(limits2), + * .max_interfaces = 8, + * .num_different_channels = 1, + * }; + * + * + * Allow #STA <= 1, #{P2P-client,P2P-GO} <= 3 on two channels, 4 total. + * This allows for an infrastructure connection and three P2P connections. + * + * struct ieee80211_iface_limit limits3[] = { + * { .max = 1, .types = BIT(NL80211_IFTYPE_STATION), }, + * { .max = 3, .types = BIT(NL80211_IFTYPE_P2P_GO) | + * BIT(NL80211_IFTYPE_P2P_CLIENT), }, + * }; + * struct ieee80211_iface_combination combination3 = { + * .limits = limits3, + * .n_limits = ARRAY_SIZE(limits3), + * .max_interfaces = 4, + * .num_different_channels = 2, + * }; + */ +struct ieee80211_iface_combination { + const struct ieee80211_iface_limit *limits; + u32 num_different_channels; + u16 max_interfaces; + u8 n_limits; + bool beacon_int_infra_match; }; struct mac_address { @@ -1653,6 +1732,11 @@ struct wiphy_wowlan_support { * @priv: driver private data (sized according to wiphy_new() parameter) * @interface_modes: bitmask of interfaces types valid for this wiphy, * must be set by driver + * @iface_combinations: Valid interface combinations array, should not + * list single interface types. + * @n_iface_combinations: number of entries in @iface_combinations array. + * @software_iftypes: bitmask of software interface types, these are not + * subject to any restrictions since they are purely managed in SW. * @flags: wiphy flags, see &enum wiphy_flags * @bss_priv_size: each BSS struct has private data allocated with it, * this variable determines its size @@ -1697,6 +1781,10 @@ struct wiphy { const struct ieee80211_txrx_stypes *mgmt_stypes; + const struct ieee80211_iface_combination *iface_combinations; + int n_iface_combinations; + u16 software_iftypes; + u16 n_addresses; /* Supported interface modes, OR together BIT(NL80211_IFTYPE_...) */ diff --git a/net/mac80211/main.c b/net/mac80211/main.c index 7f89011fa22d..79a2281678bf 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -685,7 +685,7 @@ EXPORT_SYMBOL(ieee80211_alloc_hw); int ieee80211_register_hw(struct ieee80211_hw *hw) { struct ieee80211_local *local = hw_to_local(hw); - int result; + int result, i; enum ieee80211_band band; int channels, max_bitrates; bool supp_ht; @@ -743,11 +743,19 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) return -ENOMEM; /* if low-level driver supports AP, we also support VLAN */ - if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_AP)) - local->hw.wiphy->interface_modes |= BIT(NL80211_IFTYPE_AP_VLAN); + if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_AP)) { + hw->wiphy->interface_modes |= BIT(NL80211_IFTYPE_AP_VLAN); + hw->wiphy->software_iftypes |= BIT(NL80211_IFTYPE_AP_VLAN); + } /* mac80211 always supports monitor */ - local->hw.wiphy->interface_modes |= BIT(NL80211_IFTYPE_MONITOR); + hw->wiphy->interface_modes |= BIT(NL80211_IFTYPE_MONITOR); + hw->wiphy->software_iftypes |= BIT(NL80211_IFTYPE_MONITOR); + + /* mac80211 doesn't support more than 1 channel */ + for (i = 0; i < hw->wiphy->n_iface_combinations; i++) + if (hw->wiphy->iface_combinations[i].num_different_channels > 1) + return -EINVAL; #ifndef CONFIG_MAC80211_MESH /* mesh depends on Kconfig, but drivers should set it if they want */ diff --git a/net/wireless/core.c b/net/wireless/core.c index 18b002f16860..c22ef3492ee6 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -416,6 +416,67 @@ struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv) } EXPORT_SYMBOL(wiphy_new); +static int wiphy_verify_combinations(struct wiphy *wiphy) +{ + const struct ieee80211_iface_combination *c; + int i, j; + + /* If we have combinations enforce them */ + if (wiphy->n_iface_combinations) + wiphy->flags |= WIPHY_FLAG_ENFORCE_COMBINATIONS; + + for (i = 0; i < wiphy->n_iface_combinations; i++) { + u32 cnt = 0; + u16 all_iftypes = 0; + + c = &wiphy->iface_combinations[i]; + + /* Combinations with just one interface aren't real */ + if (WARN_ON(c->max_interfaces < 2)) + return -EINVAL; + + /* Need at least one channel */ + if (WARN_ON(!c->num_different_channels)) + return -EINVAL; + + if (WARN_ON(!c->n_limits)) + return -EINVAL; + + for (j = 0; j < c->n_limits; j++) { + u16 types = c->limits[j].types; + + /* + * interface types shouldn't overlap, this is + * used in cfg80211_can_change_interface() + */ + if (WARN_ON(types & all_iftypes)) + return -EINVAL; + all_iftypes |= types; + + if (WARN_ON(!c->limits[j].max)) + return -EINVAL; + + /* Shouldn't list software iftypes in combinations! */ + if (WARN_ON(wiphy->software_iftypes & types)) + return -EINVAL; + + cnt += c->limits[j].max; + /* + * Don't advertise an unsupported type + * in a combination. + */ + if (WARN_ON((wiphy->interface_modes & types) != types)) + return -EINVAL; + } + + /* You can't even choose that many! */ + if (WARN_ON(cnt < c->max_interfaces)) + return -EINVAL; + } + + return 0; +} + int wiphy_register(struct wiphy *wiphy) { struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy); @@ -444,6 +505,10 @@ int wiphy_register(struct wiphy *wiphy) if (WARN_ON(ifmodes != wiphy->interface_modes)) wiphy->interface_modes = ifmodes; + res = wiphy_verify_combinations(wiphy); + if (res) + return res; + /* sanity check supported bands/channels */ for (band = 0; band < IEEE80211_NUM_BANDS; band++) { sband = wiphy->bands[band]; @@ -698,6 +763,7 @@ static int cfg80211_netdev_notifier_call(struct notifier_block * nb, struct net_device *dev = ndev; struct wireless_dev *wdev = dev->ieee80211_ptr; struct cfg80211_registered_device *rdev; + int ret; if (!wdev) return NOTIFY_DONE; @@ -893,6 +959,9 @@ static int cfg80211_netdev_notifier_call(struct notifier_block * nb, return notifier_from_errno(-EOPNOTSUPP); if (rfkill_blocked(rdev->rfkill)) return notifier_from_errno(-ERFKILL); + ret = cfg80211_can_add_interface(rdev, wdev->iftype); + if (ret) + return notifier_from_errno(ret); break; } diff --git a/net/wireless/core.h b/net/wireless/core.h index d4b8f4c0bbbb..bf0fb40e3c8b 100644 --- a/net/wireless/core.h +++ b/net/wireless/core.h @@ -422,6 +422,17 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev, u32 *flags, struct vif_params *params); void cfg80211_process_rdev_events(struct cfg80211_registered_device *rdev); +int cfg80211_can_change_interface(struct cfg80211_registered_device *rdev, + struct wireless_dev *wdev, + enum nl80211_iftype iftype); + +static inline int +cfg80211_can_add_interface(struct cfg80211_registered_device *rdev, + enum nl80211_iftype iftype) +{ + return cfg80211_can_change_interface(rdev, NULL, iftype); +} + struct ieee80211_channel * rdev_freq_to_chan(struct cfg80211_registered_device *rdev, int freq, enum nl80211_channel_type channel_type); diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 9ef8e287d61b..beac296b1fde 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -564,6 +564,88 @@ static int nl80211_key_allowed(struct wireless_dev *wdev) return 0; } +static int nl80211_put_iftypes(struct sk_buff *msg, u32 attr, u16 ifmodes) +{ + struct nlattr *nl_modes = nla_nest_start(msg, attr); + int i; + + if (!nl_modes) + goto nla_put_failure; + + i = 0; + while (ifmodes) { + if (ifmodes & 1) + NLA_PUT_FLAG(msg, i); + ifmodes >>= 1; + i++; + } + + nla_nest_end(msg, nl_modes); + return 0; + +nla_put_failure: + return -ENOBUFS; +} + +static int nl80211_put_iface_combinations(struct wiphy *wiphy, + struct sk_buff *msg) +{ + struct nlattr *nl_combis; + int i, j; + + nl_combis = nla_nest_start(msg, + NL80211_ATTR_INTERFACE_COMBINATIONS); + if (!nl_combis) + goto nla_put_failure; + + for (i = 0; i < wiphy->n_iface_combinations; i++) { + const struct ieee80211_iface_combination *c; + struct nlattr *nl_combi, *nl_limits; + + c = &wiphy->iface_combinations[i]; + + nl_combi = nla_nest_start(msg, i + 1); + if (!nl_combi) + goto nla_put_failure; + + nl_limits = nla_nest_start(msg, NL80211_IFACE_COMB_LIMITS); + if (!nl_limits) + goto nla_put_failure; + + for (j = 0; j < c->n_limits; j++) { + struct nlattr *nl_limit; + + nl_limit = nla_nest_start(msg, j + 1); + if (!nl_limit) + goto nla_put_failure; + NLA_PUT_U32(msg, NL80211_IFACE_LIMIT_MAX, + c->limits[j].max); + if (nl80211_put_iftypes(msg, NL80211_IFACE_LIMIT_TYPES, + c->limits[j].types)) + goto nla_put_failure; + nla_nest_end(msg, nl_limit); + } + + nla_nest_end(msg, nl_limits); + + if (c->beacon_int_infra_match) + NLA_PUT_FLAG(msg, + NL80211_IFACE_COMB_STA_AP_BI_MATCH); + NLA_PUT_U32(msg, NL80211_IFACE_COMB_NUM_CHANNELS, + c->num_different_channels); + NLA_PUT_U32(msg, NL80211_IFACE_COMB_MAXNUM, + c->max_interfaces); + + nla_nest_end(msg, nl_combi); + } + + nla_nest_end(msg, nl_combis); + + return 0; +nla_put_failure: + return -ENOBUFS; +} + static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags, struct cfg80211_registered_device *dev) { @@ -571,13 +653,11 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags, struct nlattr *nl_bands, *nl_band; struct nlattr *nl_freqs, *nl_freq; struct nlattr *nl_rates, *nl_rate; - struct nlattr *nl_modes; struct nlattr *nl_cmds; enum ieee80211_band band; struct ieee80211_channel *chan; struct ieee80211_rate *rate; int i; - u16 ifmodes = dev->wiphy.interface_modes; const struct ieee80211_txrx_stypes *mgmt_stypes = dev->wiphy.mgmt_stypes; @@ -637,20 +717,10 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags, } } - nl_modes = nla_nest_start(msg, NL80211_ATTR_SUPPORTED_IFTYPES); - if (!nl_modes) + if (nl80211_put_iftypes(msg, NL80211_ATTR_SUPPORTED_IFTYPES, + dev->wiphy.interface_modes)) goto nla_put_failure; - i = 0; - while (ifmodes) { - if (ifmodes & 1) - NLA_PUT_FLAG(msg, i); - ifmodes >>= 1; - i++; - } - - nla_nest_end(msg, nl_modes); - nl_bands = nla_nest_start(msg, NL80211_ATTR_WIPHY_BANDS); if (!nl_bands) goto nla_put_failure; @@ -865,6 +935,13 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags, nla_nest_end(msg, nl_wowlan); } + if (nl80211_put_iftypes(msg, NL80211_ATTR_SOFTWARE_IFTYPES, + dev->wiphy.software_iftypes)) + goto nla_put_failure; + + if (nl80211_put_iface_combinations(&dev->wiphy, msg)) + goto nla_put_failure; + return genlmsg_end(msg, hdr); nla_put_failure: diff --git a/net/wireless/util.c b/net/wireless/util.c index 414c9f604df6..95e4e254da0a 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -803,6 +803,11 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev, return -EBUSY; if (ntype != otype) { + err = cfg80211_can_change_interface(rdev, dev->ieee80211_ptr, + ntype); + if (err) + return err; + dev->ieee80211_ptr->use_4addr = false; dev->ieee80211_ptr->mesh_id_up_len = 0; @@ -921,3 +926,78 @@ int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev, return res; } + +int cfg80211_can_change_interface(struct cfg80211_registered_device *rdev, + struct wireless_dev *wdev, + enum nl80211_iftype iftype) +{ + struct wireless_dev *wdev_iter; + int num[NUM_NL80211_IFTYPES]; + int total = 1; + int i, j; + + ASSERT_RTNL(); + + /* Always allow software iftypes */ + if (rdev->wiphy.software_iftypes & BIT(iftype)) + return 0; + + /* + * Drivers will gradually all set this flag, until all + * have it we only enforce for those that set it. + */ + if (!(rdev->wiphy.flags & WIPHY_FLAG_ENFORCE_COMBINATIONS)) + return 0; + + memset(num, 0, sizeof(num)); + + num[iftype] = 1; + + mutex_lock(&rdev->devlist_mtx); + list_for_each_entry(wdev_iter, &rdev->netdev_list, list) { + if (wdev_iter == wdev) + continue; + if (!netif_running(wdev_iter->netdev)) + continue; + + if (rdev->wiphy.software_iftypes & BIT(wdev_iter->iftype)) + continue; + + num[wdev_iter->iftype]++; + total++; + } + mutex_unlock(&rdev->devlist_mtx); + + for (i = 0; i < rdev->wiphy.n_iface_combinations; i++) { + const struct ieee80211_iface_combination *c; + struct ieee80211_iface_limit *limits; + + c = &rdev->wiphy.iface_combinations[i]; + + limits = kmemdup(c->limits, sizeof(limits[0]) * c->n_limits, + GFP_KERNEL); + if (!limits) + return -ENOMEM; + if (total > c->max_interfaces) + goto cont; + + for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) { + if (rdev->wiphy.software_iftypes & BIT(iftype)) + continue; + for (j = 0; j < c->n_limits; j++) { + if (!(limits[j].types & iftype)) + continue; + if (limits[j].max < num[iftype]) + goto cont; + limits[j].max -= num[iftype]; + } + } + /* yay, it fits */ + kfree(limits); + return 0; + cont: + kfree(limits); + } + + return -EBUSY; +}