cfg80211-wext: return -E2BIG when buffer can't hold full BSS entry
When using the wext compatibility code in cfg80211, part of the IEs can be truncated if the passed user buffer is large enough for part of the BSS but not large enough for all of the IEs. This can cause an EAP network to show up as a PSK network. Always return -E2BIG in this case to avoid truncating data. Since this changes the control flow, use an on-stack variable for a small buffer instead of allocating it. Signed-off-by: James Minor <james.minor@ni.com> [rework patch to error out immediately, use _check wrappers] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
parent
36ef906ee8
commit
76a70e9c4b
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@ -1239,15 +1239,15 @@ int cfg80211_wext_siwscan(struct net_device *dev,
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}
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EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);
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static void ieee80211_scan_add_ies(struct iw_request_info *info,
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const struct cfg80211_bss_ies *ies,
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char **current_ev, char *end_buf)
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static char *ieee80211_scan_add_ies(struct iw_request_info *info,
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const struct cfg80211_bss_ies *ies,
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char *current_ev, char *end_buf)
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{
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const u8 *pos, *end, *next;
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struct iw_event iwe;
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if (!ies)
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return;
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return current_ev;
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/*
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* If needed, fragment the IEs buffer (at IE boundaries) into short
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@ -1264,10 +1264,11 @@ static void ieee80211_scan_add_ies(struct iw_request_info *info,
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memset(&iwe, 0, sizeof(iwe));
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iwe.cmd = IWEVGENIE;
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iwe.u.data.length = next - pos;
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*current_ev = iwe_stream_add_point(info, *current_ev,
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end_buf, &iwe,
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(void *)pos);
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current_ev = iwe_stream_add_point_check(info, current_ev,
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end_buf, &iwe,
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(void *)pos);
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if (IS_ERR(current_ev))
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return current_ev;
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pos = next;
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}
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@ -1275,10 +1276,14 @@ static void ieee80211_scan_add_ies(struct iw_request_info *info,
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memset(&iwe, 0, sizeof(iwe));
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iwe.cmd = IWEVGENIE;
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iwe.u.data.length = end - pos;
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*current_ev = iwe_stream_add_point(info, *current_ev,
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end_buf, &iwe,
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(void *)pos);
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current_ev = iwe_stream_add_point_check(info, current_ev,
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end_buf, &iwe,
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(void *)pos);
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if (IS_ERR(current_ev))
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return current_ev;
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}
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return current_ev;
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}
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static char *
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@ -1289,7 +1294,8 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
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const struct cfg80211_bss_ies *ies;
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struct iw_event iwe;
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const u8 *ie;
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u8 *buf, *cfg, *p;
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u8 buf[50];
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u8 *cfg, *p, *tmp;
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int rem, i, sig;
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bool ismesh = false;
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@ -1297,22 +1303,28 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
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iwe.cmd = SIOCGIWAP;
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iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
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memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
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current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
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IW_EV_ADDR_LEN);
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current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
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IW_EV_ADDR_LEN);
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if (IS_ERR(current_ev))
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return current_ev;
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memset(&iwe, 0, sizeof(iwe));
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iwe.cmd = SIOCGIWFREQ;
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iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
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iwe.u.freq.e = 0;
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current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
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IW_EV_FREQ_LEN);
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current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
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IW_EV_FREQ_LEN);
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if (IS_ERR(current_ev))
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return current_ev;
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memset(&iwe, 0, sizeof(iwe));
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iwe.cmd = SIOCGIWFREQ;
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iwe.u.freq.m = bss->pub.channel->center_freq;
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iwe.u.freq.e = 6;
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current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
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IW_EV_FREQ_LEN);
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current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
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IW_EV_FREQ_LEN);
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if (IS_ERR(current_ev))
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return current_ev;
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if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
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memset(&iwe, 0, sizeof(iwe));
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@ -1341,8 +1353,11 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
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/* not reached */
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break;
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}
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current_ev = iwe_stream_add_event(info, current_ev, end_buf,
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&iwe, IW_EV_QUAL_LEN);
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current_ev = iwe_stream_add_event_check(info, current_ev,
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end_buf, &iwe,
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IW_EV_QUAL_LEN);
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if (IS_ERR(current_ev))
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return current_ev;
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}
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memset(&iwe, 0, sizeof(iwe));
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@ -1352,8 +1367,10 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
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else
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iwe.u.data.flags = IW_ENCODE_DISABLED;
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iwe.u.data.length = 0;
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current_ev = iwe_stream_add_point(info, current_ev, end_buf,
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&iwe, "");
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current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
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&iwe, "");
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if (IS_ERR(current_ev))
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return current_ev;
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rcu_read_lock();
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ies = rcu_dereference(bss->pub.ies);
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@ -1371,66 +1388,91 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
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iwe.cmd = SIOCGIWESSID;
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iwe.u.data.length = ie[1];
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iwe.u.data.flags = 1;
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current_ev = iwe_stream_add_point(info, current_ev, end_buf,
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&iwe, (u8 *)ie + 2);
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current_ev = iwe_stream_add_point_check(info,
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current_ev,
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end_buf, &iwe,
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(u8 *)ie + 2);
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if (IS_ERR(current_ev))
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goto unlock;
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break;
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case WLAN_EID_MESH_ID:
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memset(&iwe, 0, sizeof(iwe));
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iwe.cmd = SIOCGIWESSID;
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iwe.u.data.length = ie[1];
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iwe.u.data.flags = 1;
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current_ev = iwe_stream_add_point(info, current_ev, end_buf,
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&iwe, (u8 *)ie + 2);
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current_ev = iwe_stream_add_point_check(info,
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current_ev,
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end_buf, &iwe,
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(u8 *)ie + 2);
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if (IS_ERR(current_ev))
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goto unlock;
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break;
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case WLAN_EID_MESH_CONFIG:
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ismesh = true;
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if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
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break;
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buf = kmalloc(50, GFP_ATOMIC);
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if (!buf)
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break;
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cfg = (u8 *)ie + 2;
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memset(&iwe, 0, sizeof(iwe));
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iwe.cmd = IWEVCUSTOM;
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sprintf(buf, "Mesh Network Path Selection Protocol ID: "
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"0x%02X", cfg[0]);
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iwe.u.data.length = strlen(buf);
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current_ev = iwe_stream_add_point(info, current_ev,
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end_buf,
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&iwe, buf);
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current_ev = iwe_stream_add_point_check(info,
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current_ev,
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end_buf,
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&iwe, buf);
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if (IS_ERR(current_ev))
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goto unlock;
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sprintf(buf, "Path Selection Metric ID: 0x%02X",
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cfg[1]);
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iwe.u.data.length = strlen(buf);
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current_ev = iwe_stream_add_point(info, current_ev,
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end_buf,
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&iwe, buf);
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current_ev = iwe_stream_add_point_check(info,
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current_ev,
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end_buf,
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&iwe, buf);
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if (IS_ERR(current_ev))
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goto unlock;
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sprintf(buf, "Congestion Control Mode ID: 0x%02X",
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cfg[2]);
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iwe.u.data.length = strlen(buf);
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current_ev = iwe_stream_add_point(info, current_ev,
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end_buf,
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&iwe, buf);
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current_ev = iwe_stream_add_point_check(info,
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current_ev,
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end_buf,
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&iwe, buf);
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if (IS_ERR(current_ev))
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goto unlock;
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sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
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iwe.u.data.length = strlen(buf);
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current_ev = iwe_stream_add_point(info, current_ev,
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end_buf,
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&iwe, buf);
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current_ev = iwe_stream_add_point_check(info,
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current_ev,
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end_buf,
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&iwe, buf);
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if (IS_ERR(current_ev))
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goto unlock;
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sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
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iwe.u.data.length = strlen(buf);
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current_ev = iwe_stream_add_point(info, current_ev,
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end_buf,
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&iwe, buf);
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current_ev = iwe_stream_add_point_check(info,
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current_ev,
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end_buf,
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&iwe, buf);
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if (IS_ERR(current_ev))
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goto unlock;
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sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
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iwe.u.data.length = strlen(buf);
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current_ev = iwe_stream_add_point(info, current_ev,
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end_buf,
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&iwe, buf);
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current_ev = iwe_stream_add_point_check(info,
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current_ev,
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end_buf,
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&iwe, buf);
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if (IS_ERR(current_ev))
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goto unlock;
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sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
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iwe.u.data.length = strlen(buf);
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current_ev = iwe_stream_add_point(info, current_ev,
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end_buf,
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&iwe, buf);
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kfree(buf);
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current_ev = iwe_stream_add_point_check(info,
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current_ev,
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end_buf,
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&iwe, buf);
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if (IS_ERR(current_ev))
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goto unlock;
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break;
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case WLAN_EID_SUPP_RATES:
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case WLAN_EID_EXT_SUPP_RATES:
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@ -1445,8 +1487,14 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
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for (i = 0; i < ie[1]; i++) {
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iwe.u.bitrate.value =
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((ie[i + 2] & 0x7f) * 500000);
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tmp = p;
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p = iwe_stream_add_value(info, current_ev, p,
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end_buf, &iwe, IW_EV_PARAM_LEN);
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end_buf, &iwe,
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IW_EV_PARAM_LEN);
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if (p == tmp) {
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current_ev = ERR_PTR(-E2BIG);
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goto unlock;
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}
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}
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current_ev = p;
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break;
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@ -1465,31 +1513,35 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
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iwe.u.mode = IW_MODE_MASTER;
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else
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iwe.u.mode = IW_MODE_ADHOC;
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current_ev = iwe_stream_add_event(info, current_ev, end_buf,
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&iwe, IW_EV_UINT_LEN);
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current_ev = iwe_stream_add_event_check(info, current_ev,
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end_buf, &iwe,
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IW_EV_UINT_LEN);
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if (IS_ERR(current_ev))
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goto unlock;
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}
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buf = kmalloc(31, GFP_ATOMIC);
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if (buf) {
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memset(&iwe, 0, sizeof(iwe));
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iwe.cmd = IWEVCUSTOM;
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sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
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iwe.u.data.length = strlen(buf);
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current_ev = iwe_stream_add_point(info, current_ev, end_buf,
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&iwe, buf);
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memset(&iwe, 0, sizeof(iwe));
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iwe.cmd = IWEVCUSTOM;
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sprintf(buf, " Last beacon: %ums ago",
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elapsed_jiffies_msecs(bss->ts));
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iwe.u.data.length = strlen(buf);
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current_ev = iwe_stream_add_point(info, current_ev,
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end_buf, &iwe, buf);
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kfree(buf);
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}
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memset(&iwe, 0, sizeof(iwe));
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iwe.cmd = IWEVCUSTOM;
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sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
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iwe.u.data.length = strlen(buf);
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current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
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&iwe, buf);
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if (IS_ERR(current_ev))
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goto unlock;
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memset(&iwe, 0, sizeof(iwe));
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iwe.cmd = IWEVCUSTOM;
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sprintf(buf, " Last beacon: %ums ago",
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elapsed_jiffies_msecs(bss->ts));
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iwe.u.data.length = strlen(buf);
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current_ev = iwe_stream_add_point_check(info, current_ev,
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end_buf, &iwe, buf);
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if (IS_ERR(current_ev))
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goto unlock;
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ieee80211_scan_add_ies(info, ies, ¤t_ev, end_buf);
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current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);
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unlock:
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rcu_read_unlock();
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return current_ev;
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}
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@ -1501,19 +1553,27 @@ static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
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char *current_ev = buf;
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char *end_buf = buf + len;
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struct cfg80211_internal_bss *bss;
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int err = 0;
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spin_lock_bh(&rdev->bss_lock);
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cfg80211_bss_expire(rdev);
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list_for_each_entry(bss, &rdev->bss_list, list) {
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if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
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spin_unlock_bh(&rdev->bss_lock);
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return -E2BIG;
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err = -E2BIG;
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break;
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}
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current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
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current_ev, end_buf);
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if (IS_ERR(current_ev)) {
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err = PTR_ERR(current_ev);
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break;
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}
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}
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spin_unlock_bh(&rdev->bss_lock);
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if (err)
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return err;
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return current_ev - buf;
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}
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