From: Felix Fietkau Date: Wed, 17 Jul 2024 15:43:52 +0200 Subject: [PATCH] wifi: cfg80211: add option for vif allowed radios This allows users to prevent a vif from affecting radios other than the configured ones. This can be useful in cases where e.g. an AP is running on one radio, and triggering a scan on another radio should not disturb it. Changing the allowed radios list for a vif is supported, but only while it is down. While it is possible to achieve the same by always explicitly specifying a frequency list for scan requests and ensuring that the wrong channel/band is never accidentally set on an unrelated interface, this change makes multi-radio wiphy setups a lot easier to deal with for CLI users. By itself, this patch only enforces the radio mask for scanning requests and remain-on-channel. Follow-up changes build on this to limit configured frequencies. Signed-off-by: Felix Fietkau --- --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -6227,6 +6227,7 @@ enum ieee80211_ap_reg_power { * entered. * @links[].cac_time_ms: CAC time in ms * @valid_links: bitmap describing what elements of @links are valid + * @radio_mask: Bitmask of radios that this interface is allowed to operate on. */ struct wireless_dev { struct wiphy *wiphy; @@ -6339,6 +6340,8 @@ struct wireless_dev { unsigned int cac_time_ms; } links[IEEE80211_MLD_MAX_NUM_LINKS]; u16 valid_links; + + u32 radio_mask; }; static inline const u8 *wdev_address(struct wireless_dev *wdev) @@ -6525,6 +6528,17 @@ bool cfg80211_radio_chandef_valid(const const struct cfg80211_chan_def *chandef); /** + * cfg80211_wdev_channel_allowed - Check if the wdev may use the channel + * + * @wdev: the wireless device + * @chan: channel to check + * + * Return: whether or not the wdev may use the channel + */ +bool cfg80211_wdev_channel_allowed(struct wireless_dev *wdev, + struct ieee80211_channel *chan); + +/** * ieee80211_get_response_rate - get basic rate for a given rate * * @sband: the band to look for rates in --- a/include/uapi/linux/nl80211.h +++ b/include/uapi/linux/nl80211.h @@ -2868,6 +2868,9 @@ enum nl80211_commands { * nested item, it contains attributes defined in * &enum nl80211_if_combination_attrs. * + * @NL80211_ATTR_VIF_RADIO_MASK: Bitmask of allowed radios (u32). + * A value of 0 means all radios. + * * @NUM_NL80211_ATTR: total number of nl80211_attrs available * @NL80211_ATTR_MAX: highest attribute number currently defined * @__NL80211_ATTR_AFTER_LAST: internal use @@ -3416,6 +3419,8 @@ enum nl80211_attrs { NL80211_ATTR_WIPHY_RADIOS, NL80211_ATTR_WIPHY_INTERFACE_COMBINATIONS, + NL80211_ATTR_VIF_RADIO_MASK, + /* add attributes here, update the policy in nl80211.c */ __NL80211_ATTR_AFTER_LAST, --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -829,6 +829,7 @@ static const struct nla_policy nl80211_p [NL80211_ATTR_MLO_TTLM_DLINK] = NLA_POLICY_EXACT_LEN(sizeof(u16) * 8), [NL80211_ATTR_MLO_TTLM_ULINK] = NLA_POLICY_EXACT_LEN(sizeof(u16) * 8), [NL80211_ATTR_ASSOC_SPP_AMSDU] = { .type = NLA_FLAG }, + [NL80211_ATTR_VIF_RADIO_MASK] = { .type = NLA_U32 }, }; /* policy for the key attributes */ @@ -3996,7 +3997,8 @@ static int nl80211_send_iface(struct sk_ nla_put_u32(msg, NL80211_ATTR_GENERATION, rdev->devlist_generation ^ (cfg80211_rdev_list_generation << 2)) || - nla_put_u8(msg, NL80211_ATTR_4ADDR, wdev->use_4addr)) + nla_put_u8(msg, NL80211_ATTR_4ADDR, wdev->use_4addr) || + nla_put_u32(msg, NL80211_ATTR_VIF_RADIO_MASK, wdev->radio_mask)) goto nla_put_failure; if (rdev->ops->get_channel && !wdev->valid_links) { @@ -4312,6 +4314,29 @@ static int nl80211_valid_4addr(struct cf return -EOPNOTSUPP; } +static int nl80211_parse_vif_radio_mask(struct genl_info *info, + u32 *radio_mask) +{ + struct cfg80211_registered_device *rdev = info->user_ptr[0]; + struct nlattr *attr = info->attrs[NL80211_ATTR_VIF_RADIO_MASK]; + u32 mask, allowed; + + if (!attr) { + *radio_mask = 0; + return 0; + } + + allowed = BIT(rdev->wiphy.n_radio) - 1; + mask = nla_get_u32(attr); + if (mask & ~allowed) + return -EINVAL; + if (!mask) + mask = allowed; + *radio_mask = mask; + + return 1; +} + static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info) { struct cfg80211_registered_device *rdev = info->user_ptr[0]; @@ -4319,6 +4344,8 @@ static int nl80211_set_interface(struct int err; enum nl80211_iftype otype, ntype; struct net_device *dev = info->user_ptr[1]; + struct wireless_dev *wdev = dev->ieee80211_ptr; + u32 radio_mask = 0; bool change = false; memset(¶ms, 0, sizeof(params)); @@ -4332,8 +4359,6 @@ static int nl80211_set_interface(struct } if (info->attrs[NL80211_ATTR_MESH_ID]) { - struct wireless_dev *wdev = dev->ieee80211_ptr; - if (ntype != NL80211_IFTYPE_MESH_POINT) return -EINVAL; if (otype != NL80211_IFTYPE_MESH_POINT) @@ -4364,6 +4389,12 @@ static int nl80211_set_interface(struct if (err > 0) change = true; + err = nl80211_parse_vif_radio_mask(info, &radio_mask); + if (err < 0) + return err; + if (err && netif_running(dev)) + return -EBUSY; + if (change) err = cfg80211_change_iface(rdev, dev, ntype, ¶ms); else @@ -4372,11 +4403,11 @@ static int nl80211_set_interface(struct if (!err && params.use_4addr != -1) dev->ieee80211_ptr->use_4addr = params.use_4addr; - if (change && !err) { - struct wireless_dev *wdev = dev->ieee80211_ptr; + if (radio_mask) + wdev->radio_mask = radio_mask; + if (change && !err) nl80211_notify_iface(rdev, wdev, NL80211_CMD_SET_INTERFACE); - } return err; } @@ -4387,6 +4418,7 @@ static int _nl80211_new_interface(struct struct vif_params params; struct wireless_dev *wdev; struct sk_buff *msg; + u32 radio_mask; int err; enum nl80211_iftype type = NL80211_IFTYPE_UNSPECIFIED; @@ -4424,6 +4456,10 @@ static int _nl80211_new_interface(struct if (err < 0) return err; + err = nl80211_parse_vif_radio_mask(info, &radio_mask); + if (err < 0) + return err; + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (!msg) return -ENOMEM; @@ -4465,6 +4501,9 @@ static int _nl80211_new_interface(struct break; } + if (radio_mask) + wdev->radio_mask = radio_mask; + if (nl80211_send_iface(msg, info->snd_portid, info->snd_seq, 0, rdev, wdev, NL80211_CMD_NEW_INTERFACE) < 0) { nlmsg_free(msg); @@ -9180,6 +9219,9 @@ static bool cfg80211_off_channel_oper_al lockdep_assert_wiphy(wdev->wiphy); + if (!cfg80211_wdev_channel_allowed(wdev, chan)) + return false; + if (!cfg80211_beaconing_iface_active(wdev)) return true; @@ -9392,7 +9434,8 @@ static int nl80211_trigger_scan(struct s } /* ignore disabled channels */ - if (chan->flags & IEEE80211_CHAN_DISABLED) + if (chan->flags & IEEE80211_CHAN_DISABLED || + !cfg80211_wdev_channel_allowed(wdev, chan)) continue; request->channels[i] = chan; @@ -9412,7 +9455,8 @@ static int nl80211_trigger_scan(struct s chan = &wiphy->bands[band]->channels[j]; - if (chan->flags & IEEE80211_CHAN_DISABLED) + if (chan->flags & IEEE80211_CHAN_DISABLED || + !cfg80211_wdev_channel_allowed(wdev, chan)) continue; request->channels[i] = chan; --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -956,7 +956,8 @@ static int cfg80211_scan_6ghz(struct cfg struct ieee80211_channel *chan = ieee80211_get_channel(&rdev->wiphy, ap->center_freq); - if (!chan || chan->flags & IEEE80211_CHAN_DISABLED) + if (!chan || chan->flags & IEEE80211_CHAN_DISABLED || + !cfg80211_wdev_channel_allowed(rdev_req->wdev, chan)) continue; for (i = 0; i < rdev_req->n_channels; i++) { @@ -3490,9 +3491,12 @@ int cfg80211_wext_siwscan(struct net_dev continue; for (j = 0; j < wiphy->bands[band]->n_channels; j++) { + struct ieee80211_channel *chan; + /* ignore disabled channels */ - if (wiphy->bands[band]->channels[j].flags & - IEEE80211_CHAN_DISABLED) + chan = &wiphy->bands[band]->channels[j]; + if (chan->flags & IEEE80211_CHAN_DISABLED || + !cfg80211_wdev_channel_allowed(creq->wdev, chan)) continue; /* If we have a wireless request structure and the --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -2923,3 +2923,32 @@ bool cfg80211_radio_chandef_valid(const return true; } EXPORT_SYMBOL(cfg80211_radio_chandef_valid); + +bool cfg80211_wdev_channel_allowed(struct wireless_dev *wdev, + struct ieee80211_channel *chan) +{ + struct wiphy *wiphy = wdev->wiphy; + const struct wiphy_radio *radio; + struct cfg80211_chan_def chandef; + u32 radio_mask; + int i; + + radio_mask = wdev->radio_mask; + if (!wiphy->n_radio || radio_mask == BIT(wiphy->n_radio) - 1) + return true; + + cfg80211_chandef_create(&chandef, chan, NL80211_CHAN_HT20); + for (i = 0; i < wiphy->n_radio; i++) { + if (!(radio_mask & BIT(i))) + continue; + + radio = &wiphy->radio[i]; + if (!cfg80211_radio_chandef_valid(radio, &chandef)) + continue; + + return true; + } + + return false; +} +EXPORT_SYMBOL(cfg80211_wdev_channel_allowed); --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -1415,6 +1415,8 @@ void cfg80211_init_wdev(struct wireless_ /* allow mac80211 to determine the timeout */ wdev->ps_timeout = -1; + wdev->radio_mask = BIT(wdev->wiphy->n_radio) - 1; + if ((wdev->iftype == NL80211_IFTYPE_STATION || wdev->iftype == NL80211_IFTYPE_P2P_CLIENT || wdev->iftype == NL80211_IFTYPE_ADHOC) && !wdev->use_4addr)