On Wed, 2010-01-06 at 16:19 +0200, Jouni Malinen wrote:
> Store information elements from Beacon and Probe Response frames in
> separate buffers to allow both sets to be made available through
> nl80211. This allows user space applications to get access to IEs from
> Beacon frames even if we have received Probe Response frames from the
> BSS. Previously, the IEs from Probe Response frames would have
> overridden the IEs from Beacon frames.
>
> This feature is of somewhat limited use since most protocols include
> the same (or extended) information in Probe Response frames. However,
> there are couple of exceptions where the IEs from Beacon frames could
> be of some use: TIM IE is only included in Beacon frames (and it would
> be needed to figure out the DTIM period used in the BSS) and at least
> some implementations of Wireless Provisioning Services seem to include
> the full IE only in Beacon frames).
>
> The new BSS attribute for scan results is added to allow both the IE
> sets to be delivered. This is done in a way that maintains the
> previously used behavior for applications that are not aware of the
> new NL80211_BSS_BEACON_IES attribute.
>
> Signed-off-by: Jouni Malinen <j@xxxxx>
Acked-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
>
> ---
> include/linux/nl80211.h | 10 +++-
> include/net/cfg80211.h | 12 ++++
> net/wireless/core.h | 3 -
> net/wireless/nl80211.c | 4 +
> net/wireless/scan.c | 120
> ++++++++++++++++++++++++++++++++++++------------
> 5 files changed, 116 insertions(+), 33 deletions(-)
>
> --- uml.orig/include/linux/nl80211.h 2010-01-06 14:50:20.000000000
> +0200
> +++ uml/include/linux/nl80211.h 2010-01-06 16:03:25.000000000 +0200
> @@ -1399,13 +1399,20 @@ enum nl80211_channel_type {
> * @NL80211_BSS_BEACON_INTERVAL: beacon interval of the (I)BSS (u16)
> * @NL80211_BSS_CAPABILITY: capability field (CPU order, u16)
> * @NL80211_BSS_INFORMATION_ELEMENTS: binary attribute containing the
> - * raw information elements from the probe response/beacon (bin)
> + * raw information elements from the probe response/beacon (bin);
> + * if the %NL80211_BSS_BEACON_IES attribute is present, the IEs here
> are
> + * from a Probe Response frame; otherwise they are from a Beacon
> frame.
> + * However, if the driver does not indicate the source of the IEs,
> these
> + * IEs may be from either frame subtype.
> * @NL80211_BSS_SIGNAL_MBM: signal strength of probe response/beacon
> * in mBm (100 * dBm) (s32)
> * @NL80211_BSS_SIGNAL_UNSPEC: signal strength of the probe
> response/beacon
> * in unspecified units, scaled to 0..100 (u8)
> * @NL80211_BSS_STATUS: status, if this BSS is "used"
> * @NL80211_BSS_SEEN_MS_AGO: age of this BSS entry in ms
> + * @NL80211_BSS_BEACON_IES: binary attribute containing the raw
> information
> + * elements from a Beacon frame (bin); not present if no Beacon frame
> has
> + * yet been received
> * @__NL80211_BSS_AFTER_LAST: internal
> * @NL80211_BSS_MAX: highest BSS attribute
> */
> @@ -1421,6 +1428,7 @@ enum nl80211_bss {
> NL80211_BSS_SIGNAL_UNSPEC,
> NL80211_BSS_STATUS,
> NL80211_BSS_SEEN_MS_AGO,
> + NL80211_BSS_BEACON_IES,
>
> /* keep last */
> __NL80211_BSS_AFTER_LAST,
> --- uml.orig/include/net/cfg80211.h 2010-01-06 14:47:50.000000000
> +0200
> +++ uml/include/net/cfg80211.h 2010-01-06 14:49:50.000000000 +0200
> @@ -626,8 +626,14 @@ enum cfg80211_signal_type {
> * @beacon_interval: the beacon interval as from the frame
> * @capability: the capability field in host byte order
> * @information_elements: the information elements (Note that there
> - * is no guarantee that these are well-formed!)
> + * is no guarantee that these are well-formed!); this is a pointer to
> + * either the beacon_ies or proberesp_ies depending on whether Probe
> + * Response frame has been received
> * @len_information_elements: total length of the information
> elements
> + * @beacon_ies: the information elements from the last Beacon frame
> + * @len_beacon_ies: total length of the beacon_ies
> + * @proberesp_ies: the information elements from the last Probe
> Response frame
> + * @len_proberesp_ies: total length of the proberesp_ies
> * @signal: signal strength value (type depends on the wiphy's
> signal_type)
> * @free_priv: function pointer to free private data
> * @priv: private area for driver use, has at least wiphy->bss_priv_s
> ize bytes
> @@ -641,6 +647,10 @@ struct cfg80211_bss {
> u16 capability;
> u8 *information_elements;
> size_t len_information_elements;
> + u8 *beacon_ies;
> + size_t len_beacon_ies;
> + u8 *proberesp_ies;
> + size_t len_proberesp_ies;
>
> s32 signal;
>
> --- uml.orig/net/wireless/core.h 2010-01-06 14:55:19.000000000 +0200
> +++ uml/net/wireless/core.h 2010-01-06 14:55:37.000000000 +0200
> @@ -111,7 +111,8 @@ struct cfg80211_internal_bss {
> unsigned long ts;
> struct kref ref;
> atomic_t hold;
> - bool ies_allocated;
> + bool beacon_ies_allocated;
> + bool proberesp_ies_allocated;
>
> /* must be last because of priv member */
> struct cfg80211_bss pub;
> --- uml.orig/net/wireless/nl80211.c 2010-01-06 14:47:11.000000000
> +0200
> +++ uml/net/wireless/nl80211.c 2010-01-06 15:07:19.000000000 +0200
> @@ -3151,6 +3151,10 @@ static int nl80211_send_bss(struct sk_bu
> NLA_PUT(msg, NL80211_BSS_INFORMATION_ELEMENTS,
> res->len_information_elements,
> res->information_elements);
> + if (res->beacon_ies && res->len_beacon_ies &&
> + res->beacon_ies != res->information_elements)
> + NLA_PUT(msg, NL80211_BSS_BEACON_IES,
> + res->len_beacon_ies, res->beacon_ies);
> if (res->tsf)
> NLA_PUT_U64(msg, NL80211_BSS_TSF, res->tsf);
> if (res->beacon_interval)
> --- uml.orig/net/wireless/scan.c 2010-01-06 14:46:47.000000000 +0200
> +++ uml/net/wireless/scan.c 2010-01-06 15:34:30.000000000 +0200
> @@ -100,8 +100,10 @@ static void bss_release(struct kref *ref
> if (bss->pub.free_priv)
> bss->pub.free_priv(&bss->pub);
>
> - if (bss->ies_allocated)
> - kfree(bss->pub.information_elements);
> + if (bss->beacon_ies_allocated)
> + kfree(bss->pub.beacon_ies);
> + if (bss->proberesp_ies_allocated)
> + kfree(bss->pub.proberesp_ies);
>
> BUG_ON(atomic_read(&bss->hold));
>
> @@ -375,8 +377,7 @@ rb_find_bss(struct cfg80211_registered_d
>
> static struct cfg80211_internal_bss *
> cfg80211_bss_update(struct cfg80211_registered_device *dev,
> - struct cfg80211_internal_bss *res,
> - bool overwrite)
> + struct cfg80211_internal_bss *res)
> {
> struct cfg80211_internal_bss *found = NULL;
> const u8 *meshid, *meshcfg;
> @@ -418,28 +419,64 @@ cfg80211_bss_update(struct cfg80211_regi
> found->pub.capability = res->pub.capability;
> found->ts = res->ts;
>
> - /* overwrite IEs */
> - if (overwrite) {
> + /* Update IEs */
> + if (res->pub.proberesp_ies) {
> size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
> - size_t ielen = res->pub.len_information_elements;
> + size_t ielen = res->pub.len_proberesp_ies;
>
> - if (!found->ies_allocated && ksize(found) >= used + ielen) {
> - memcpy(found->pub.information_elements,
> - res->pub.information_elements, ielen);
> - found->pub.len_information_elements = ielen;
> + if (found->pub.proberesp_ies &&
> + !found->proberesp_ies_allocated &&
> + ksize(found) >= used + ielen) {
> + memcpy(found->pub.proberesp_ies,
> + res->pub.proberesp_ies, ielen);
> + found->pub.len_proberesp_ies = ielen;
> } else {
> - u8 *ies = found->pub.information_elements;
> + u8 *ies = found->pub.proberesp_ies;
>
> - if (found->ies_allocated)
> + if (found->proberesp_ies_allocated)
> ies = krealloc(ies, ielen, GFP_ATOMIC);
> else
> ies = kmalloc(ielen, GFP_ATOMIC);
>
> if (ies) {
> - memcpy(ies, res->pub.information_elements, ielen);
> - found->ies_allocated = true;
> - found->pub.information_elements = ies;
> - found->pub.len_information_elements = ielen;
> + memcpy(ies, res->pub.proberesp_ies,
> + ielen);
> + found->proberesp_ies_allocated = true;
> + found->pub.proberesp_ies = ies;
> + found->pub.len_proberesp_ies = ielen;
> + }
> + }
> +
> + /* Override possible earlier Beacon frame IEs */
> + found->pub.information_elements =
> + found->pub.proberesp_ies;
> + found->pub.len_information_elements =
> + found->pub.len_proberesp_ies;
> + }
> + if (res->pub.beacon_ies) {
> + size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
> + size_t ielen = res->pub.len_beacon_ies;
> +
> + if (found->pub.beacon_ies &&
> + !found->beacon_ies_allocated &&
> + ksize(found) >= used + ielen) {
> + memcpy(found->pub.beacon_ies,
> + res->pub.beacon_ies, ielen);
> + found->pub.len_beacon_ies = ielen;
> + } else {
> + u8 *ies = found->pub.beacon_ies;
> +
> + if (found->beacon_ies_allocated)
> + ies = krealloc(ies, ielen, GFP_ATOMIC);
> + else
> + ies = kmalloc(ielen, GFP_ATOMIC);
> +
> + if (ies) {
> + memcpy(ies, res->pub.beacon_ies,
> + ielen);
> + found->beacon_ies_allocated = true;
> + found->pub.beacon_ies = ies;
> + found->pub.len_beacon_ies = ielen;
> }
> }
> }
> @@ -489,14 +526,26 @@ cfg80211_inform_bss(struct wiphy *wiphy,
> res->pub.tsf = timestamp;
> res->pub.beacon_interval = beacon_interval;
> res->pub.capability = capability;
> - /* point to after the private area */
> - res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
> - memcpy(res->pub.information_elements, ie, ielen);
> - res->pub.len_information_elements = ielen;
> + /*
> + * Since we do not know here whether the IEs are from a Beacon or
> Probe
> + * Response frame, we need to pick one of the options and only use
> it
> + * with the driver that does not provide the full Beacon/Probe
> Response
> + * frame. Use Beacon frame pointer to avoid indicating that this
> should
> + * override the information_elements pointer should we have received
> an
> + * earlier indication of Probe Response data.
> + *
> + * The initial buffer for the IEs is allocated with the BSS entry
> and
> + * is located after the private area.
> + */
> + res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
> + memcpy(res->pub.beacon_ies, ie, ielen);
> + res->pub.len_beacon_ies = ielen;
> + res->pub.information_elements = res->pub.beacon_ies;
> + res->pub.len_information_elements = res->pub.len_beacon_ies;
>
> kref_init(&res->ref);
>
> - res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0);
> + res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
> if (!res)
> return NULL;
>
> @@ -517,7 +566,6 @@ cfg80211_inform_bss_frame(struct wiphy *
> struct cfg80211_internal_bss *res;
> size_t ielen = len - offsetof(struct ieee80211_mgmt,
> u.probe_resp.variable);
> - bool overwrite;
> size_t privsz = wiphy->bss_priv_size;
>
> if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
> @@ -538,16 +586,28 @@ cfg80211_inform_bss_frame(struct wiphy *
> res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
> res->pub.beacon_interval =
> le16_to_cpu(mgmt->u.probe_resp.beacon_int);
> res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
> - /* point to after the private area */
> - res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
> - memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable,
> ielen);
> - res->pub.len_information_elements = ielen;
> + /*
> + * The initial buffer for the IEs is allocated with the BSS entry
> and
> + * is located after the private area.
> + */
> + if (ieee80211_is_probe_resp(mgmt->frame_control)) {
> + res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
> + memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
> + ielen);
> + res->pub.len_proberesp_ies = ielen;
> + res->pub.information_elements = res->pub.proberesp_ies;
> + res->pub.len_information_elements = res->pub.len_proberesp_ies;
> + } else {
> + res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
> + memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
> + res->pub.len_beacon_ies = ielen;
> + res->pub.information_elements = res->pub.beacon_ies;
> + res->pub.len_information_elements = res->pub.len_beacon_ies;
> + }
>
> kref_init(&res->ref);
>
> - overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
> -
> - res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
> + res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
> if (!res)
> return NULL;
>
>
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