Return-path: Received: from mms3.broadcom.com ([216.31.210.19]:3427 "EHLO mms3.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752270Ab3DKKkU (ORCPT ); Thu, 11 Apr 2013 06:40:20 -0400 From: "Arend van Spriel" To: "Johannes Berg" cc: linux-wireless , "Arend van Spriel" Subject: [PATCH V6] cfg80211: introduce critical protocol indication from user-space Date: Thu, 11 Apr 2013 12:39:54 +0200 Message-ID: <1365676794-24717-1-git-send-email-arend@broadcom.com> (sfid-20130411_124027_661567_1FBB5A0A) In-Reply-To: <1365412173-7428-1-git-send-email-arend@broadcom.com> References: <1365412173-7428-1-git-send-email-arend@broadcom.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-wireless-owner@vger.kernel.org List-ID: Some protocols need a more reliable connection to complete successful in reasonable time. This patch adds a user-space API to indicate the wireless driver that a critical protocol is about to commence and when it is done, using nl80211 primitives NL80211_CMD_CRIT_PROTOCOL_START and NL80211_CRIT_PROTOCOL_STOP. There can be only on critical protocol session started per registered cfg80211 device. The driver can support this by implementing the cfg80211 callbacks .crit_proto_start() and .crit_proto_stop(). Examples of protocols that can benefit from this are DHCP, EAPOL, APIPA. Exactly how the link can/should be made more reliable is up to the driver. Things to consider are avoid scanning, no multi-channel operations, and alter coexistence schemes. Reviewed-by: Pieter-Paul Giesberts Reviewed-by: Franky (Zhenhui) Lin Signed-off-by: Arend van Spriel --- Hi Johannes, I reworked the patch based on your comment in this V6. It applies to the master branch on top of commit: 5253ffb mac80211: always pick a basic rate to tx RTS/CTS for pre-HT rates Regards, Arend Changelog: ---------- V6: - added crit_proto_stopped event message. - use nlportid as flag for critical protocol being active. - return error when duration is over specified limit. - remove logic from rdev_* inline wrappers. - added more documentation. - some renaming of identifiers. V5: - change return type for .crit_prot_stop() to void. - correct limiting the duration. V4: - added cfg80211_crit_proto_stopped() for drivers to use. - added back protocol identifier for drivers to use. - reject starting critical protocol session when already started. - critical protocol session tracked per registered device. V3: - remove protocol identifier. - remove delayed work from cfg80211. - guard maximum limit for duration. - do .crit_proto_stop() upon netlink socket release. V2: - subject changed. Below previous subject is given for reference: [RFC] cfg80211: configuration of Bluetooth coexistence mode - introduced dedicated nl80211 API. V1: - initial proposal. --- include/net/cfg80211.h | 27 ++++++++++ include/uapi/linux/nl80211.h | 40 +++++++++++++++ net/wireless/core.h | 3 ++ net/wireless/mlme.c | 5 ++ net/wireless/nl80211.c | 116 ++++++++++++++++++++++++++++++++++++++++++ net/wireless/rdev-ops.h | 24 ++++++++- net/wireless/trace.h | 35 +++++++++++++ 7 files changed, 249 insertions(+), 1 deletion(-) diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index 57870b6..7afd1ad 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -2002,6 +2002,12 @@ struct cfg80211_update_ft_ies_params { * @update_ft_ies: Provide updated Fast BSS Transition information to the * driver. If the SME is in the driver/firmware, this information can be * used in building Authentication and Reassociation Request frames. + * + * @crit_proto_start: Indicates a critical protocol needs more link reliability + * for a given duration (milliseconds). The protocol is provided so the + * driver can take the most appropriate actions. + * @crit_proto_stop: Indicates critical protocol no longer needs increased link + * reliability. This operation can not fail. */ struct cfg80211_ops { int (*suspend)(struct wiphy *wiphy, struct cfg80211_wowlan *wow); @@ -2231,6 +2237,12 @@ struct cfg80211_ops { struct cfg80211_chan_def *chandef); int (*update_ft_ies)(struct wiphy *wiphy, struct net_device *dev, struct cfg80211_update_ft_ies_params *ftie); + int (*crit_proto_start)(struct wiphy *wiphy, + struct wireless_dev *wdev, + enum nl80211_crit_proto_id protocol, + u16 duration); + void (*crit_proto_stop)(struct wiphy *wiphy, + struct wireless_dev *wdev); }; /* @@ -2830,6 +2842,7 @@ struct cfg80211_cached_keys; * @p2p_started: true if this is a P2P Device that has been started * @cac_started: true if DFS channel availability check has been started * @cac_start_time: timestamp (jiffies) when the dfs state was entered. + * @crit_proto_started: true if crit_proto_start() has been done. */ struct wireless_dev { struct wiphy *wiphy; @@ -2884,6 +2897,8 @@ struct wireless_dev { bool cac_started; unsigned long cac_start_time; + bool crit_proto_started; + #ifdef CONFIG_CFG80211_WEXT /* wext data */ struct { @@ -4126,6 +4141,18 @@ void cfg80211_report_wowlan_wakeup(struct wireless_dev *wdev, struct cfg80211_wowlan_wakeup *wakeup, gfp_t gfp); +/** + * cfg80211_crit_proto_stopped() - indicate critical protocol stopped by driver. + * + * @wdev: the wireless device for which critical protocol is stopped. + * + * This function can be called by the driver to indicate it has reverted + * operation back to normal. One reason could be that the duration given + * by .crit_proto_start() has expired. This function must not be called + * in .crit_proto_stop() context. + */ +void cfg80211_crit_proto_stopped(struct wireless_dev *wdev, gfp_t gfp); + /* Logging, debugging and troubleshooting/diagnostic helpers. */ /* wiphy_printk helpers, similar to dev_printk */ diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h index 79da871..c68373b 100644 --- a/include/uapi/linux/nl80211.h +++ b/include/uapi/linux/nl80211.h @@ -639,6 +639,13 @@ * with the relevant Information Elements. This event is used to report * received FT IEs (MDIE, FTIE, RSN IE, TIE, RICIE). * + * @NL80211_CMD_CRIT_PROTOCOL_START: Indicates user-space will start running + * a critical protocol that needs more reliability in the connection to + * complete. + * + * @NL80211_CMD_CRIT_PROTOCOL_STOP: Indicates the connection reliability can + * return back to normal. + * * @NL80211_CMD_MAX: highest used command number * @__NL80211_CMD_AFTER_LAST: internal use */ @@ -798,6 +805,10 @@ enum nl80211_commands { NL80211_CMD_UPDATE_FT_IES, NL80211_CMD_FT_EVENT, + NL80211_CMD_CRIT_PROTOCOL_START, + NL80211_CMD_CRIT_PROTOCOL_STOP, + NL80211_CMD_CRIT_PROTOCOL_STOPPED_EVENT, + /* add new commands above here */ /* used to define NL80211_CMD_MAX below */ @@ -1414,6 +1425,11 @@ enum nl80211_commands { * @NL80211_ATTR_IE_RIC: Resource Information Container Information * Element * + * @NL80211_ATTR_CRIT_PROT_ID: critical protocol identifier requiring increased + * reliability, see &enum nl80211_crit_proto_id (u16). + * @NL80211_ATTR_MAX_CRIT_PROT_DURATION: duration in milliseconds in which + * the connection should have increased reliability (u16). + * * @NL80211_ATTR_MAX: highest attribute number currently defined * @__NL80211_ATTR_AFTER_LAST: internal use */ @@ -1709,6 +1725,9 @@ enum nl80211_attrs { NL80211_ATTR_MDID, NL80211_ATTR_IE_RIC, + NL80211_ATTR_CRIT_PROT_ID, + NL80211_ATTR_MAX_CRIT_PROT_DURATION, + /* add attributes here, update the policy in nl80211.c */ __NL80211_ATTR_AFTER_LAST, @@ -3682,4 +3701,25 @@ enum nl80211_protocol_features { NL80211_PROTOCOL_FEATURE_SPLIT_WIPHY_DUMP = 1 << 0, }; +/** + * enum nl80211_crit_proto_id - nl80211 critical protocol identifiers + * + * @NL80211_CRIT_PROTO_UNSPEC: protocol unspecified. + * @NL80211_CRIT_PROTO_DHCP: BOOTP or DHCPv6 protocol. + * @NL80211_CRIT_PROTO_EAPOL: EAPOL protocol. + * @NL80211_CRIT_PROTO_APIPA: APIPA protocol. + * @NUM_NL80211_CRIT_PROTO: must be kept last. + */ +enum nl80211_crit_proto_id { + NL80211_CRIT_PROTO_UNSPEC, + NL80211_CRIT_PROTO_DHCP, + NL80211_CRIT_PROTO_EAPOL, + NL80211_CRIT_PROTO_APIPA, + /* add other protocols before this one */ + NUM_NL80211_CRIT_PROTO +}; + +/* maximum duration for critical protocol measures */ +#define NL80211_CRIT_PROTO_MAX_DURATION 5000 /* msec */ + #endif /* __LINUX_NL80211_H */ diff --git a/net/wireless/core.h b/net/wireless/core.h index d5d06fd..eac5308 100644 --- a/net/wireless/core.h +++ b/net/wireless/core.h @@ -88,6 +88,9 @@ struct cfg80211_registered_device { struct delayed_work dfs_update_channels_wk; + /* netlink port which started critical protocol (0 means not started) */ + u32 crit_proto_nlportid; + /* must be last because of the way we do wiphy_priv(), * and it should at least be aligned to NETDEV_ALIGN */ struct wiphy wiphy __aligned(NETDEV_ALIGN); diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c index 390198b..719c2f8 100644 --- a/net/wireless/mlme.c +++ b/net/wireless/mlme.c @@ -648,6 +648,11 @@ void cfg80211_mlme_unregister_socket(struct wireless_dev *wdev, u32 nlportid) spin_unlock_bh(&wdev->mgmt_registrations_lock); + if (nlportid && rdev->crit_proto_nlportid == nlportid) { + rdev_crit_proto_stop(rdev, wdev); + rdev->crit_proto_nlportid = 0; + } + if (nlportid == wdev->ap_unexpected_nlportid) wdev->ap_unexpected_nlportid = 0; } diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index f924d45..533eccf 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -1417,6 +1417,10 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, } CMD(start_p2p_device, START_P2P_DEVICE); CMD(set_mcast_rate, SET_MCAST_RATE); + if (split) { + CMD(crit_proto_start, CRIT_PROTOCOL_START); + CMD(crit_proto_stop, CRIT_PROTOCOL_STOP); + } #ifdef CONFIG_NL80211_TESTMODE CMD(testmode_cmd, TESTMODE); @@ -8196,6 +8200,64 @@ static int nl80211_update_ft_ies(struct sk_buff *skb, struct genl_info *info) return rdev_update_ft_ies(rdev, dev, &ft_params); } +static int nl80211_crit_protocol_start(struct sk_buff *skb, + struct genl_info *info) +{ + struct cfg80211_registered_device *rdev = info->user_ptr[0]; + struct wireless_dev *wdev = info->user_ptr[1]; + enum nl80211_crit_proto_id proto = NL80211_CRIT_PROTO_UNSPEC; + u16 duration; + int ret; + + if (!rdev->ops->crit_proto_start) + return -EOPNOTSUPP; + + if (WARN_ON(!rdev->ops->crit_proto_stop)) + return -EINVAL; + + if (rdev->crit_proto_nlportid) + return -EBUSY; + + /* determine protocol if provided */ + if (info->attrs[NL80211_ATTR_CRIT_PROT_ID]) + proto = nla_get_u16(info->attrs[NL80211_ATTR_CRIT_PROT_ID]); + + if (proto >= NUM_NL80211_CRIT_PROTO) + return -EINVAL; + + /* timeout must be provided */ + if (!info->attrs[NL80211_ATTR_MAX_CRIT_PROT_DURATION]) + return -EINVAL; + + duration = + nla_get_u16(info->attrs[NL80211_ATTR_MAX_CRIT_PROT_DURATION]); + + if (duration > NL80211_CRIT_PROTO_MAX_DURATION) + return -ERANGE; + + ret = rdev_crit_proto_start(rdev, wdev, proto, duration); + if (!ret) + rdev->crit_proto_nlportid = info->snd_portid; + + return ret; +} + +static int nl80211_crit_protocol_stop(struct sk_buff *skb, + struct genl_info *info) +{ + struct cfg80211_registered_device *rdev = info->user_ptr[0]; + struct wireless_dev *wdev = info->user_ptr[1]; + + if (!rdev->ops->crit_proto_stop) + return -EOPNOTSUPP; + + if (rdev->crit_proto_nlportid) { + rdev_crit_proto_stop(rdev, wdev); + rdev->crit_proto_nlportid = 0; + } + return 0; +} + #define NL80211_FLAG_NEED_WIPHY 0x01 #define NL80211_FLAG_NEED_NETDEV 0x02 #define NL80211_FLAG_NEED_RTNL 0x04 @@ -8885,6 +8947,22 @@ static struct genl_ops nl80211_ops[] = { .internal_flags = NL80211_FLAG_NEED_NETDEV_UP | NL80211_FLAG_NEED_RTNL, }, + { + .cmd = NL80211_CMD_CRIT_PROTOCOL_START, + .doit = nl80211_crit_protocol_start, + .policy = nl80211_policy, + .flags = GENL_ADMIN_PERM, + .internal_flags = NL80211_FLAG_NEED_WDEV_UP | + NL80211_FLAG_NEED_RTNL, + }, + { + .cmd = NL80211_CMD_CRIT_PROTOCOL_STOP, + .doit = nl80211_crit_protocol_stop, + .policy = nl80211_policy, + .flags = GENL_ADMIN_PERM, + .internal_flags = NL80211_FLAG_NEED_WDEV_UP | + NL80211_FLAG_NEED_RTNL, + } }; static struct genl_multicast_group nl80211_mlme_mcgrp = { @@ -10630,6 +10708,44 @@ void cfg80211_ft_event(struct net_device *netdev, } EXPORT_SYMBOL(cfg80211_ft_event); +void cfg80211_crit_proto_stopped(struct wireless_dev *wdev, gfp_t gfp) +{ + struct cfg80211_registered_device *rdev; + struct sk_buff *msg; + void *hdr; + u32 nlportid; + + rdev = wiphy_to_dev(wdev->wiphy); + WARN_ON(!rdev->crit_proto_nlportid); + nlportid = rdev->crit_proto_nlportid; + rdev->crit_proto_nlportid = 0; + + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp); + if (!msg) + return; + + hdr = nl80211hdr_put(msg, 0, 0, 0, + NL80211_CMD_CRIT_PROTOCOL_STOPPED_EVENT); + if (!hdr) + goto nla_put_failure; + + if (nla_put_u32(msg, NL80211_ATTR_WIPHY, rdev->wiphy_idx) || + nla_put_u64(msg, NL80211_ATTR_WDEV, wdev_id(wdev))) + goto nla_put_failure; + + genlmsg_end(msg, hdr); + + genlmsg_unicast(wiphy_net(&rdev->wiphy), msg, nlportid); + return; + + nla_put_failure: + if (hdr) + genlmsg_cancel(msg, hdr); + nlmsg_free(msg); + +} +EXPORT_SYMBOL(cfg80211_crit_proto_stopped); + /* initialisation/exit functions */ int nl80211_init(void) diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h index d77e1c1..9f15f0a 100644 --- a/net/wireless/rdev-ops.h +++ b/net/wireless/rdev-ops.h @@ -875,7 +875,7 @@ static inline void rdev_stop_p2p_device(struct cfg80211_registered_device *rdev, trace_rdev_stop_p2p_device(&rdev->wiphy, wdev); rdev->ops->stop_p2p_device(&rdev->wiphy, wdev); trace_rdev_return_void(&rdev->wiphy); -} +} static inline int rdev_set_mac_acl(struct cfg80211_registered_device *rdev, struct net_device *dev, @@ -901,4 +901,26 @@ static inline int rdev_update_ft_ies(struct cfg80211_registered_device *rdev, return ret; } +static inline int rdev_crit_proto_start(struct cfg80211_registered_device *rdev, + struct wireless_dev *wdev, + enum nl80211_crit_proto_id protocol, + u16 duration) +{ + int ret; + + trace_rdev_crit_proto_start(&rdev->wiphy, wdev, protocol, duration); + ret = rdev->ops->crit_proto_start(&rdev->wiphy, wdev, + protocol, duration); + trace_rdev_return_int(&rdev->wiphy, ret); + return ret; +} + +static inline void rdev_crit_proto_stop(struct cfg80211_registered_device *rdev, + struct wireless_dev *wdev) +{ + trace_rdev_crit_proto_stop(&rdev->wiphy, wdev); + rdev->ops->crit_proto_stop(&rdev->wiphy, wdev); + trace_rdev_return_void(&rdev->wiphy); +} + #endif /* __CFG80211_RDEV_OPS */ diff --git a/net/wireless/trace.h b/net/wireless/trace.h index ccadef2..499c982 100644 --- a/net/wireless/trace.h +++ b/net/wireless/trace.h @@ -1805,6 +1805,41 @@ TRACE_EVENT(rdev_update_ft_ies, WIPHY_PR_ARG, NETDEV_PR_ARG, __entry->md) ); +TRACE_EVENT(rdev_crit_proto_start, + TP_PROTO(struct wiphy *wiphy, struct wireless_dev *wdev, + enum nl80211_crit_proto_id protocol, u16 duration), + TP_ARGS(wiphy, wdev, protocol, duration), + TP_STRUCT__entry( + WIPHY_ENTRY + WDEV_ENTRY + __field(u16, proto) + __field(u16, duration) + ), + TP_fast_assign( + WIPHY_ASSIGN; + WDEV_ASSIGN; + __entry->proto = protocol; + __entry->duration = duration; + ), + TP_printk(WIPHY_PR_FMT ", " WDEV_PR_FMT ", proto=%x, duration=%u", + WIPHY_PR_ARG, WDEV_PR_ARG, __entry->proto, __entry->duration) +); + +TRACE_EVENT(rdev_crit_proto_stop, + TP_PROTO(struct wiphy *wiphy, struct wireless_dev *wdev), + TP_ARGS(wiphy, wdev), + TP_STRUCT__entry( + WIPHY_ENTRY + WDEV_ENTRY + ), + TP_fast_assign( + WIPHY_ASSIGN; + WDEV_ASSIGN; + ), + TP_printk(WIPHY_PR_FMT ", " WDEV_PR_FMT, + WIPHY_PR_ARG, WDEV_PR_ARG) +); + /************************************************************* * cfg80211 exported functions traces * *************************************************************/ -- 1.7.10.4