From ad7e718c9b4f717823fd920a0103f7b0fb06183f Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 13 Nov 2013 13:37:47 +0100 Subject: [PATCH] nl80211: vendor command support Add support for vendor-specific commands to nl80211. This is intended to be used for really vendor-specific functionality that can't be implemented in a generic fashion for any reason. It's *NOT* intended to be used for any normal/generic feature or any optimisations that could be implemented across drivers. Currently, only vendor commands (with replies) are supported, no dump operations or vendor-specific notifications. Also add a function wdev_to_ieee80211_vif() to mac80211 which is needed for mac80211-based drivers wanting to implement any vendor commands. Signed-off-by: Johannes Berg --- include/net/cfg80211.h | 116 ++++++++++++++++++++- include/net/mac80211.h | 13 +++ include/uapi/linux/nl80211.h | 41 ++++++++ net/mac80211/util.c | 11 ++ net/wireless/core.h | 4 +- net/wireless/nl80211.c | 237 ++++++++++++++++++++++++++++++------------- 6 files changed, 348 insertions(+), 74 deletions(-) diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index 47290a4..884ac69 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -2680,6 +2680,34 @@ struct wiphy_coalesce_support { }; /** + * enum wiphy_vendor_command_flags - validation flags for vendor commands + * @WIPHY_VENDOR_CMD_NEED_WDEV: vendor command requires wdev + * @WIPHY_VENDOR_CMD_NEED_NETDEV: vendor command requires netdev + * @WIPHY_VENDOR_CMD_NEED_RUNNING: interface/wdev must be up & running + * (must be combined with %_WDEV or %_NETDEV) + */ +enum wiphy_vendor_command_flags { + WIPHY_VENDOR_CMD_NEED_WDEV = BIT(0), + WIPHY_VENDOR_CMD_NEED_NETDEV = BIT(1), + WIPHY_VENDOR_CMD_NEED_RUNNING = BIT(2), +}; + +/** + * struct wiphy_vendor_command - vendor command definition + * @info: vendor command identifying information, as used in nl80211 + * @flags: flags, see &enum wiphy_vendor_command_flags + * @doit: callback for the operation, note that wdev is %NULL if the + * flags didn't ask for a wdev and non-%NULL otherwise; the data + * pointer may be %NULL if userspace provided no data at all + */ +struct wiphy_vendor_command { + struct nl80211_vendor_cmd_info info; + u32 flags; + int (*doit)(struct wiphy *wiphy, struct wireless_dev *wdev, + const void *data, int data_len); +}; + +/** * struct wiphy - wireless hardware description * @reg_notifier: the driver's regulatory notification callback, * note that if your driver uses wiphy_apply_custom_regulatory() @@ -2792,6 +2820,9 @@ struct wiphy_coalesce_support { * @extended_capabilities_mask: mask of the valid values * @extended_capabilities_len: length of the extended capabilities * @coalesce: packet coalescing support information + * + * @vendor_commands: array of vendor commands supported by the hardware + * @n_vendor_commands: number of vendor commands */ struct wiphy { /* assign these fields before you register the wiphy */ @@ -2903,6 +2934,9 @@ struct wiphy { const struct wiphy_coalesce_support *coalesce; + const struct wiphy_vendor_command *vendor_commands; + int n_vendor_commands; + char priv[0] __aligned(NETDEV_ALIGN); }; @@ -3847,6 +3881,75 @@ void wiphy_rfkill_start_polling(struct wiphy *wiphy); */ void wiphy_rfkill_stop_polling(struct wiphy *wiphy); +/** + * DOC: Vendor commands + * + * Occasionally, there are special protocol or firmware features that + * can't be implemented very openly. For this and similar cases, the + * vendor command functionality allows implementing the features with + * (typically closed-source) userspace and firmware, using nl80211 as + * the configuration mechanism. + * + * A driver supporting vendor commands must register them as an array + * in struct wiphy, with handlers for each one, each command has an + * OUI and sub command ID to identify it. + * + * Note that this feature should not be (ab)used to implement protocol + * features that could openly be shared across drivers. In particular, + * it must never be required to use vendor commands to implement any + * "normal" functionality that higher-level userspace like connection + * managers etc. need. + */ + +struct sk_buff *__cfg80211_alloc_reply_skb(struct wiphy *wiphy, + enum nl80211_commands cmd, + enum nl80211_attrs attr, + int approxlen); + +/** + * cfg80211_vendor_cmd_alloc_reply_skb - allocate vendor command reply + * @wiphy: the wiphy + * @approxlen: an upper bound of the length of the data that will + * be put into the skb + * + * This function allocates and pre-fills an skb for a reply to + * a vendor command. Since it is intended for a reply, calling + * it outside of a vendor command's doit() operation is invalid. + * + * The returned skb is pre-filled with some identifying data in + * a way that any data that is put into the skb (with skb_put(), + * nla_put() or similar) will end up being within the + * %NL80211_ATTR_VENDOR_DATA attribute, so all that needs to be done + * with the skb is adding data for the corresponding userspace tool + * which can then read that data out of the vendor data attribute. + * You must not modify the skb in any other way. + * + * When done, call cfg80211_vendor_cmd_reply() with the skb and return + * its error code as the result of the doit() operation. + * + * Return: An allocated and pre-filled skb. %NULL if any errors happen. + */ +static inline struct sk_buff * +cfg80211_vendor_cmd_alloc_reply_skb(struct wiphy *wiphy, int approxlen) +{ + return __cfg80211_alloc_reply_skb(wiphy, NL80211_CMD_VENDOR, + NL80211_ATTR_VENDOR_DATA, approxlen); +} + +/** + * cfg80211_vendor_cmd_reply - send the reply skb + * @skb: The skb, must have been allocated with + * cfg80211_vendor_cmd_alloc_reply_skb() + * + * Since calling this function will usually be the last thing + * before returning from the vendor command doit() you should + * return the error code. Note that this function consumes the + * skb regardless of the return value. + * + * Return: An error code or 0 on success. + */ +int cfg80211_vendor_cmd_reply(struct sk_buff *skb); + #ifdef CONFIG_NL80211_TESTMODE /** * DOC: Test mode @@ -3882,8 +3985,12 @@ void wiphy_rfkill_stop_polling(struct wiphy *wiphy); * * Return: An allocated and pre-filled skb. %NULL if any errors happen. */ -struct sk_buff *cfg80211_testmode_alloc_reply_skb(struct wiphy *wiphy, - int approxlen); +static inline struct sk_buff * +cfg80211_testmode_alloc_reply_skb(struct wiphy *wiphy, int approxlen) +{ + return __cfg80211_alloc_reply_skb(wiphy, NL80211_CMD_TESTMODE, + NL80211_ATTR_TESTDATA, approxlen); +} /** * cfg80211_testmode_reply - send the reply skb @@ -3897,7 +4004,10 @@ struct sk_buff *cfg80211_testmode_alloc_reply_skb(struct wiphy *wiphy, * * Return: An error code or 0 on success. */ -int cfg80211_testmode_reply(struct sk_buff *skb); +static inline int cfg80211_testmode_reply(struct sk_buff *skb) +{ + return cfg80211_vendor_cmd_reply(skb); +} /** * cfg80211_testmode_alloc_event_skb - allocate testmode event diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 73d99bc..c014acc 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -1163,6 +1163,19 @@ static inline bool ieee80211_vif_is_mesh(struct ieee80211_vif *vif) } /** + * wdev_to_ieee80211_vif - return a vif struct from a wdev + * @wdev: the wdev to get the vif for + * + * This can be used by mac80211 drivers with direct cfg80211 APIs + * (like the vendor commands) that get a wdev. + * + * Note that this function may return %NULL if the given wdev isn't + * associated with a vif that the driver knows about (e.g. monitor + * or AP_VLAN interfaces.) + */ +struct ieee80211_vif *wdev_to_ieee80211_vif(struct wireless_dev *wdev); + +/** * enum ieee80211_key_flags - key flags * * These flags are used for communication about keys between the driver diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h index 9a4d0e1..72ba358 100644 --- a/include/uapi/linux/nl80211.h +++ b/include/uapi/linux/nl80211.h @@ -693,6 +693,15 @@ * other station that transmission must be blocked until the channel * switch is complete. * + * @NL80211_CMD_VENDOR: Vendor-specified command/event. The command is specified + * by the %NL80211_ATTR_VENDOR_ID attribute and a sub-command in + * %NL80211_ATTR_VENDOR_SUBCMD. Parameter(s) can be transported in + * %NL80211_ATTR_VENDOR_DATA. + * For feature advertisement, the %NL80211_ATTR_VENDOR_DATA attribute is + * used in the wiphy data as a nested attribute containing descriptions + * (&struct nl80211_vendor_cmd_info) of the supported vendor commands. + * This may also be sent as an event with the same attributes. + * * @NL80211_CMD_MAX: highest used command number * @__NL80211_CMD_AFTER_LAST: internal use */ @@ -860,6 +869,8 @@ enum nl80211_commands { NL80211_CMD_CHANNEL_SWITCH, + NL80211_CMD_VENDOR, + /* add new commands above here */ /* used to define NL80211_CMD_MAX below */ @@ -1524,6 +1535,12 @@ enum nl80211_commands { * Notification Element based on association request when used with * %NL80211_CMD_NEW_STATION; u8 attribute. * + * @NL80211_ATTR_VENDOR_ID: The vendor ID, either a 24-bit OUI or, if + * %NL80211_VENDOR_ID_IS_LINUX is set, a special Linux ID (not used yet) + * @NL80211_ATTR_VENDOR_SUBCMD: vendor sub-command + * @NL80211_ATTR_VENDOR_DATA: data for the vendor command, if any; this + * attribute is also used for vendor command feature advertisement + * * @NL80211_ATTR_MAX: highest attribute number currently defined * @__NL80211_ATTR_AFTER_LAST: internal use */ @@ -1845,6 +1862,10 @@ enum nl80211_attrs { NL80211_ATTR_OPMODE_NOTIF, + NL80211_ATTR_VENDOR_ID, + NL80211_ATTR_VENDOR_SUBCMD, + NL80211_ATTR_VENDOR_DATA, + /* add attributes here, update the policy in nl80211.c */ __NL80211_ATTR_AFTER_LAST, @@ -3965,4 +3986,24 @@ enum nl80211_rxmgmt_flags { NL80211_RXMGMT_FLAG_ANSWERED = 1 << 0, }; +/* + * If this flag is unset, the lower 24 bits are an OUI, if set + * a Linux nl80211 vendor ID is used (no such IDs are allocated + * yet, so that's not valid so far) + */ +#define NL80211_VENDOR_ID_IS_LINUX 0x80000000 + +/** + * struct nl80211_vendor_cmd_info - vendor command data + * @vendor_id: If the %NL80211_VENDOR_ID_IS_LINUX flag is clear, then the + * value is a 24-bit OUI; if it is set then a separately allocated ID + * may be used, but no such IDs are allocated yet. New IDs should be + * added to this file when needed. + * @subcmd: sub-command ID for the command + */ +struct nl80211_vendor_cmd_info { + __u32 vendor_id; + __u32 subcmd; +}; + #endif /* __LINUX_NL80211_H */ diff --git a/net/mac80211/util.c b/net/mac80211/util.c index 06265d7..4a376a7 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -642,6 +642,17 @@ void ieee80211_iterate_active_interfaces_rtnl( } EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_rtnl); +struct ieee80211_vif *wdev_to_ieee80211_vif(struct wireless_dev *wdev) +{ + struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev); + + if (!ieee80211_sdata_running(sdata) || + !(sdata->flags & IEEE80211_SDATA_IN_DRIVER)) + return NULL; + return &sdata->vif; +} +EXPORT_SYMBOL_GPL(wdev_to_ieee80211_vif); + /* * Nothing should have been stuffed into the workqueue during * the suspend->resume cycle. If this WARN is seen then there diff --git a/net/wireless/core.h b/net/wireless/core.h index 6716c5c..ac77644 100644 --- a/net/wireless/core.h +++ b/net/wireless/core.h @@ -67,9 +67,7 @@ struct cfg80211_registered_device { struct work_struct scan_done_wk; struct work_struct sched_scan_results_wk; -#ifdef CONFIG_NL80211_TESTMODE - struct genl_info *testmode_info; -#endif + struct genl_info *cur_cmd_info; struct work_struct conn_work; struct work_struct event_work; diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index bdcf256..6989989 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -358,6 +358,9 @@ static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = { [NL80211_ATTR_STA_SUPPORTED_OPER_CLASSES] = { .type = NLA_BINARY }, [NL80211_ATTR_HANDLE_DFS] = { .type = NLA_FLAG }, [NL80211_ATTR_OPMODE_NOTIF] = { .type = NLA_U8 }, + [NL80211_ATTR_VENDOR_ID] = { .type = NLA_U32 }, + [NL80211_ATTR_VENDOR_SUBCMD] = { .type = NLA_U32 }, + [NL80211_ATTR_VENDOR_DATA] = { .type = NLA_BINARY }, }; /* policy for the key attributes */ @@ -1166,6 +1169,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, struct nlattr *nl_bands, *nl_band; struct nlattr *nl_freqs, *nl_freq; struct nlattr *nl_cmds; + struct nlattr *nl_vendor_cmds; enum ieee80211_band band; struct ieee80211_channel *chan; int i; @@ -1561,6 +1565,19 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, (nla_put_flag(msg, NL80211_ATTR_SUPPORT_5_MHZ) || nla_put_flag(msg, NL80211_ATTR_SUPPORT_10_MHZ))) goto nla_put_failure; + state->split_start++; + break; + case 11: + nl_vendor_cmds = nla_nest_start(msg, NL80211_ATTR_VENDOR_DATA); + if (!nl_vendor_cmds) + goto nla_put_failure; + + for (i = 0; i < dev->wiphy.n_vendor_commands; i++) + if (nla_put(msg, i + 1, + sizeof(struct nl80211_vendor_cmd_info), + &dev->wiphy.vendor_commands[i].info)) + goto nla_put_failure; + nla_nest_end(msg, nl_vendor_cmds); /* done */ state->split_start = 0; @@ -6682,6 +6699,40 @@ static int nl80211_set_mcast_rate(struct sk_buff *skb, struct genl_info *info) return err; } +static struct sk_buff * +__cfg80211_alloc_vendor_skb(struct cfg80211_registered_device *rdev, + int approxlen, u32 portid, u32 seq, + enum nl80211_commands cmd, + enum nl80211_attrs attr, gfp_t gfp) +{ + struct sk_buff *skb; + void *hdr; + struct nlattr *data; + + skb = nlmsg_new(approxlen + 100, gfp); + if (!skb) + return NULL; + + hdr = nl80211hdr_put(skb, portid, seq, 0, cmd); + if (!hdr) { + kfree_skb(skb); + return NULL; + } + + if (nla_put_u32(skb, NL80211_ATTR_WIPHY, rdev->wiphy_idx)) + goto nla_put_failure; + data = nla_nest_start(skb, attr); + + ((void **)skb->cb)[0] = rdev; + ((void **)skb->cb)[1] = hdr; + ((void **)skb->cb)[2] = data; + + return skb; + + nla_put_failure: + kfree_skb(skb); + return NULL; +} #ifdef CONFIG_NL80211_TESTMODE static struct genl_multicast_group nl80211_testmode_mcgrp = { @@ -6710,11 +6761,11 @@ static int nl80211_testmode_do(struct sk_buff *skb, struct genl_info *info) if (!info->attrs[NL80211_ATTR_TESTDATA]) return -EINVAL; - rdev->testmode_info = info; + rdev->cur_cmd_info = info; err = rdev_testmode_cmd(rdev, wdev, nla_data(info->attrs[NL80211_ATTR_TESTDATA]), nla_len(info->attrs[NL80211_ATTR_TESTDATA])); - rdev->testmode_info = NULL; + rdev->cur_cmd_info = NULL; return err; } @@ -6814,77 +6865,14 @@ static int nl80211_testmode_dump(struct sk_buff *skb, return err; } -static struct sk_buff * -__cfg80211_testmode_alloc_skb(struct cfg80211_registered_device *rdev, - int approxlen, u32 portid, u32 seq, gfp_t gfp) -{ - struct sk_buff *skb; - void *hdr; - struct nlattr *data; - - skb = nlmsg_new(approxlen + 100, gfp); - if (!skb) - return NULL; - - hdr = nl80211hdr_put(skb, portid, seq, 0, NL80211_CMD_TESTMODE); - if (!hdr) { - kfree_skb(skb); - return NULL; - } - - if (nla_put_u32(skb, NL80211_ATTR_WIPHY, rdev->wiphy_idx)) - goto nla_put_failure; - data = nla_nest_start(skb, NL80211_ATTR_TESTDATA); - - ((void **)skb->cb)[0] = rdev; - ((void **)skb->cb)[1] = hdr; - ((void **)skb->cb)[2] = data; - - return skb; - - nla_put_failure: - kfree_skb(skb); - return NULL; -} - -struct sk_buff *cfg80211_testmode_alloc_reply_skb(struct wiphy *wiphy, - int approxlen) -{ - struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy); - - if (WARN_ON(!rdev->testmode_info)) - return NULL; - - return __cfg80211_testmode_alloc_skb(rdev, approxlen, - rdev->testmode_info->snd_portid, - rdev->testmode_info->snd_seq, - GFP_KERNEL); -} -EXPORT_SYMBOL(cfg80211_testmode_alloc_reply_skb); - -int cfg80211_testmode_reply(struct sk_buff *skb) -{ - struct cfg80211_registered_device *rdev = ((void **)skb->cb)[0]; - void *hdr = ((void **)skb->cb)[1]; - struct nlattr *data = ((void **)skb->cb)[2]; - - if (WARN_ON(!rdev->testmode_info)) { - kfree_skb(skb); - return -EINVAL; - } - - nla_nest_end(skb, data); - genlmsg_end(skb, hdr); - return genlmsg_reply(skb, rdev->testmode_info); -} -EXPORT_SYMBOL(cfg80211_testmode_reply); - struct sk_buff *cfg80211_testmode_alloc_event_skb(struct wiphy *wiphy, int approxlen, gfp_t gfp) { struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy); - return __cfg80211_testmode_alloc_skb(rdev, approxlen, 0, 0, gfp); + return __cfg80211_alloc_vendor_skb(rdev, approxlen, 0, 0, + NL80211_CMD_TESTMODE, + NL80211_ATTR_TESTDATA, gfp); } EXPORT_SYMBOL(cfg80211_testmode_alloc_event_skb); @@ -8867,6 +8855,111 @@ static int nl80211_crit_protocol_stop(struct sk_buff *skb, return 0; } +static int nl80211_vendor_cmd(struct sk_buff *skb, struct genl_info *info) +{ + struct cfg80211_registered_device *rdev = info->user_ptr[0]; + struct wireless_dev *wdev = + __cfg80211_wdev_from_attrs(genl_info_net(info), info->attrs); + int i, err; + u32 vid, subcmd; + + if (!rdev->wiphy.vendor_commands) + return -EOPNOTSUPP; + + if (IS_ERR(wdev)) { + err = PTR_ERR(wdev); + if (err != -EINVAL) + return err; + wdev = NULL; + } else if (wdev->wiphy != &rdev->wiphy) { + return -EINVAL; + } + + if (!info->attrs[NL80211_ATTR_VENDOR_ID] || + !info->attrs[NL80211_ATTR_VENDOR_SUBCMD]) + return -EINVAL; + + vid = nla_get_u32(info->attrs[NL80211_ATTR_VENDOR_ID]); + subcmd = nla_get_u32(info->attrs[NL80211_ATTR_VENDOR_SUBCMD]); + for (i = 0; i < rdev->wiphy.n_vendor_commands; i++) { + const struct wiphy_vendor_command *vcmd; + void *data = NULL; + int len = 0; + + vcmd = &rdev->wiphy.vendor_commands[i]; + + if (vcmd->info.vendor_id != vid || vcmd->info.subcmd != subcmd) + continue; + + if (vcmd->flags & (WIPHY_VENDOR_CMD_NEED_WDEV | + WIPHY_VENDOR_CMD_NEED_NETDEV)) { + if (!wdev) + return -EINVAL; + if (vcmd->flags & WIPHY_VENDOR_CMD_NEED_NETDEV && + !wdev->netdev) + return -EINVAL; + + if (vcmd->flags & WIPHY_VENDOR_CMD_NEED_RUNNING) { + if (wdev->netdev && + !netif_running(wdev->netdev)) + return -ENETDOWN; + if (!wdev->netdev && !wdev->p2p_started) + return -ENETDOWN; + } + } else { + wdev = NULL; + } + + if (info->attrs[NL80211_ATTR_VENDOR_DATA]) { + data = nla_data(info->attrs[NL80211_ATTR_VENDOR_DATA]); + len = nla_len(info->attrs[NL80211_ATTR_VENDOR_DATA]); + } + + rdev->cur_cmd_info = info; + err = rdev->wiphy.vendor_commands[i].doit(&rdev->wiphy, wdev, + data, len); + rdev->cur_cmd_info = NULL; + return err; + } + + return -EOPNOTSUPP; +} + +struct sk_buff *__cfg80211_alloc_reply_skb(struct wiphy *wiphy, + enum nl80211_commands cmd, + enum nl80211_attrs attr, + int approxlen) +{ + struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy); + + if (WARN_ON(!rdev->cur_cmd_info)) + return NULL; + + return __cfg80211_alloc_vendor_skb(rdev, approxlen, + rdev->cur_cmd_info->snd_portid, + rdev->cur_cmd_info->snd_seq, + cmd, attr, GFP_KERNEL); +} +EXPORT_SYMBOL(__cfg80211_alloc_reply_skb); + +int cfg80211_vendor_cmd_reply(struct sk_buff *skb) +{ + struct cfg80211_registered_device *rdev = ((void **)skb->cb)[0]; + void *hdr = ((void **)skb->cb)[1]; + struct nlattr *data = ((void **)skb->cb)[2]; + + if (WARN_ON(!rdev->cur_cmd_info)) { + kfree_skb(skb); + return -EINVAL; + } + + nla_nest_end(skb, data); + genlmsg_end(skb, hdr); + return genlmsg_reply(skb, rdev->cur_cmd_info); +} +EXPORT_SYMBOL_GPL(cfg80211_vendor_cmd_reply); + + #define NL80211_FLAG_NEED_WIPHY 0x01 #define NL80211_FLAG_NEED_NETDEV 0x02 #define NL80211_FLAG_NEED_RTNL 0x04 @@ -9591,6 +9684,14 @@ static struct genl_ops nl80211_ops[] = { .internal_flags = NL80211_FLAG_NEED_NETDEV_UP | NL80211_FLAG_NEED_RTNL, }, + { + .cmd = NL80211_CMD_VENDOR, + .doit = nl80211_vendor_cmd, + .policy = nl80211_policy, + .flags = GENL_ADMIN_PERM, + .internal_flags = NL80211_FLAG_NEED_WIPHY | + NL80211_FLAG_NEED_RTNL, + }, }; static struct genl_multicast_group nl80211_mlme_mcgrp = { -- 2.7.4