mac80211: minstrel: avoid accessing negative indices in rix_to_ndx()
[linux-2.6] / net / mac80211 / spectmgmt.c
1 /*
2  * spectrum management
3  *
4  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5  * Copyright 2002-2005, Instant802 Networks, Inc.
6  * Copyright 2005-2006, Devicescape Software, Inc.
7  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
8  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9  * Copyright 2007-2008, Intel Corporation
10  * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License version 2 as
14  * published by the Free Software Foundation.
15  */
16
17 #include <linux/ieee80211.h>
18 #include <net/cfg80211.h>
19 #include <net/mac80211.h>
20 #include "ieee80211_i.h"
21 #include "sta_info.h"
22 #include "wme.h"
23
24 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
25                                         struct ieee80211_msrment_ie *request_ie,
26                                         const u8 *da, const u8 *bssid,
27                                         u8 dialog_token)
28 {
29         struct ieee80211_local *local = sdata->local;
30         struct sk_buff *skb;
31         struct ieee80211_mgmt *msr_report;
32
33         skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
34                                 sizeof(struct ieee80211_msrment_ie));
35
36         if (!skb) {
37                 printk(KERN_ERR "%s: failed to allocate buffer for "
38                                 "measurement report frame\n", sdata->dev->name);
39                 return;
40         }
41
42         skb_reserve(skb, local->hw.extra_tx_headroom);
43         msr_report = (struct ieee80211_mgmt *)skb_put(skb, 24);
44         memset(msr_report, 0, 24);
45         memcpy(msr_report->da, da, ETH_ALEN);
46         memcpy(msr_report->sa, sdata->dev->dev_addr, ETH_ALEN);
47         memcpy(msr_report->bssid, bssid, ETH_ALEN);
48         msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
49                                                 IEEE80211_STYPE_ACTION);
50
51         skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
52         msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
53         msr_report->u.action.u.measurement.action_code =
54                                 WLAN_ACTION_SPCT_MSR_RPRT;
55         msr_report->u.action.u.measurement.dialog_token = dialog_token;
56
57         msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
58         msr_report->u.action.u.measurement.length =
59                         sizeof(struct ieee80211_msrment_ie);
60
61         memset(&msr_report->u.action.u.measurement.msr_elem, 0,
62                 sizeof(struct ieee80211_msrment_ie));
63         msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
64         msr_report->u.action.u.measurement.msr_elem.mode |=
65                         IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
66         msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
67
68         ieee80211_tx_skb(sdata, skb, 1);
69 }
70
71 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
72                                        struct ieee80211_mgmt *mgmt,
73                                        size_t len)
74 {
75         /*
76          * Ignoring measurement request is spec violation.
77          * Mandatory measurements must be reported optional
78          * measurements might be refused or reported incapable
79          * For now just refuse
80          * TODO: Answer basic measurement as unmeasured
81          */
82         ieee80211_send_refuse_measurement_request(sdata,
83                         &mgmt->u.action.u.measurement.msr_elem,
84                         mgmt->sa, mgmt->bssid,
85                         mgmt->u.action.u.measurement.dialog_token);
86 }