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-rw-r--r--include/net/mac80211.h3
-rw-r--r--net/mac80211/ieee80211_sta.c90
-rw-r--r--net/mac80211/rx.c5
3 files changed, 67 insertions, 31 deletions
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 1a1d0d8203a..784ab769b00 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -276,7 +276,8 @@ struct ieee80211_tx_control {
* @RX_FLAG_FAILED_PLCP_CRC: Set this flag if the PCLP check failed on
* the frame.
* @RX_FLAG_TSFT: The timestamp passed in the RX status (@mactime field)
- * is valid.
+ * is valid. This is useful in monitor mode and necessary for beacon frames
+ * to enable IBSS merging.
*/
enum mac80211_rx_flags {
RX_FLAG_MMIC_ERROR = 1<<0,
diff --git a/net/mac80211/ieee80211_sta.c b/net/mac80211/ieee80211_sta.c
index a84ead49b1e..6e5b57dccc5 100644
--- a/net/mac80211/ieee80211_sta.c
+++ b/net/mac80211/ieee80211_sta.c
@@ -2199,7 +2199,7 @@ static void ieee80211_rx_bss_info(struct net_device *dev,
struct ieee80211_sta_bss *bss;
struct sta_info *sta;
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
- u64 timestamp;
+ u64 beacon_timestamp, rx_timestamp;
DECLARE_MAC_BUF(mac);
DECLARE_MAC_BUF(mac2);
@@ -2216,31 +2216,7 @@ static void ieee80211_rx_bss_info(struct net_device *dev,
if (baselen > len)
return;
- timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
-
- if (sdata->vif.type == IEEE80211_IF_TYPE_IBSS && beacon &&
- memcmp(mgmt->bssid, sdata->u.sta.bssid, ETH_ALEN) == 0) {
-#ifdef CONFIG_MAC80211_IBSS_DEBUG
- static unsigned long last_tsf_debug = 0;
- u64 tsf;
- if (local->ops->get_tsf)
- tsf = local->ops->get_tsf(local_to_hw(local));
- else
- tsf = -1LLU;
- if (time_after(jiffies, last_tsf_debug + 5 * HZ)) {
- printk(KERN_DEBUG "RX beacon SA=%s BSSID="
- "%s TSF=0x%llx BCN=0x%llx diff=%lld "
- "@%lu\n",
- print_mac(mac, mgmt->sa), print_mac(mac2, mgmt->bssid),
- (unsigned long long)tsf,
- (unsigned long long)timestamp,
- (unsigned long long)(tsf - timestamp),
- jiffies);
- last_tsf_debug = jiffies;
- }
-#endif /* CONFIG_MAC80211_IBSS_DEBUG */
- }
-
+ beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
if (sdata->vif.type == IEEE80211_IF_TYPE_IBSS && elems.supp_rates &&
@@ -2326,8 +2302,10 @@ static void ieee80211_rx_bss_info(struct net_device *dev,
bss->band = rx_status->band;
- if (bss->probe_resp && beacon) {
- /* Do not allow beacon to override data from Probe Response. */
+ if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
+ bss->probe_resp && beacon) {
+ /* STA mode:
+ * Do not allow beacon to override data from Probe Response. */
ieee80211_rx_bss_put(dev, bss);
return;
}
@@ -2424,13 +2402,67 @@ static void ieee80211_rx_bss_info(struct net_device *dev,
bss->ht_ie_len = 0;
}
- bss->timestamp = timestamp;
+ bss->timestamp = beacon_timestamp;
bss->last_update = jiffies;
bss->rssi = rx_status->ssi;
bss->signal = rx_status->signal;
bss->noise = rx_status->noise;
if (!beacon)
bss->probe_resp++;
+
+ /* check if we need to merge IBSS */
+ if (sdata->vif.type == IEEE80211_IF_TYPE_IBSS && beacon &&
+ !local->sta_sw_scanning && !local->sta_hw_scanning &&
+ mgmt->u.beacon.capab_info & WLAN_CAPABILITY_IBSS &&
+ bss->freq == local->oper_channel->center_freq &&
+ elems.ssid_len == sdata->u.sta.ssid_len &&
+ memcmp(elems.ssid, sdata->u.sta.ssid, sdata->u.sta.ssid_len) == 0) {
+ if (rx_status->flag & RX_FLAG_TSFT) {
+ /* in order for correct IBSS merging we need mactime
+ *
+ * since mactime is defined as the time the first data
+ * symbol of the frame hits the PHY, and the timestamp
+ * of the beacon is defined as "the time that the data
+ * symbol containing the first bit of the timestamp is
+ * transmitted to the PHY plus the transmitting STA’s
+ * delays through its local PHY from the MAC-PHY
+ * interface to its interface with the WM"
+ * (802.11 11.1.2) - equals the time this bit arrives at
+ * the receiver - we have to take into account the
+ * offset between the two.
+ * e.g: at 1 MBit that means mactime is 192 usec earlier
+ * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
+ */
+ int rate = local->hw.wiphy->bands[rx_status->band]->
+ bitrates[rx_status->rate_idx].bitrate;
+ rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
+ } else if (local && local->ops && local->ops->get_tsf)
+ /* second best option: get current TSF */
+ rx_timestamp = local->ops->get_tsf(local_to_hw(local));
+ else
+ /* can't merge without knowing the TSF */
+ rx_timestamp = -1LLU;
+#ifdef CONFIG_MAC80211_IBSS_DEBUG
+ printk(KERN_DEBUG "RX beacon SA=%s BSSID="
+ "%s TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
+ print_mac(mac, mgmt->sa),
+ print_mac(mac2, mgmt->bssid),
+ (unsigned long long)rx_timestamp,
+ (unsigned long long)beacon_timestamp,
+ (unsigned long long)(rx_timestamp - beacon_timestamp),
+ jiffies);
+#endif /* CONFIG_MAC80211_IBSS_DEBUG */
+ if (beacon_timestamp > rx_timestamp) {
+ if (CONFIG_MAC80211_IBSS_DEBUG || net_ratelimit())
+ printk(KERN_DEBUG "%s: beacon TSF higher than "
+ "local TSF - IBSS merge with BSSID %s\n",
+ dev->name, print_mac(mac, mgmt->bssid));
+ ieee80211_sta_join_ibss(dev, &sdata->u.sta, bss);
+ ieee80211_ibss_add_sta(dev, NULL,
+ mgmt->bssid, mgmt->sa);
+ }
+ }
+
ieee80211_rx_bss_put(dev, bss);
}
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 472b19fc914..279ee493520 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1695,7 +1695,10 @@ static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
case IEEE80211_IF_TYPE_IBSS:
if (!bssid)
return 0;
- if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
+ if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT &&
+ (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON)
+ return 1;
+ else if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
return 0;
rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-10 23:00:29 +0000