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1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "wificond/net/netlink_utils.h"
18 
19 #include <array>
20 #include <algorithm>
21 #include <bitset>
22 #include <map>
23 #include <string>
24 #include <vector>
25 
26 #include <net/if.h>
27 #include <linux/netlink.h>
28 
29 #include <android-base/logging.h>
30 
31 #include "wificond/net/kernel-header-latest/nl80211.h"
32 #include "wificond/net/mlme_event_handler.h"
33 #include "wificond/net/nl80211_packet.h"
34 
35 using std::array;
36 using std::make_pair;
37 using std::make_unique;
38 using std::map;
39 using std::move;
40 using std::pair;
41 using std::string;
42 using std::unique_ptr;
43 using std::vector;
44 
45 namespace android {
46 namespace wificond {
47 
48 namespace {
49 
50 uint32_t k2GHzFrequencyLowerBound = 2400;
51 uint32_t k2GHzFrequencyUpperBound = 2500;
52 
53 uint32_t k5GHzFrequencyLowerBound = 5000;
54 uint32_t k5GHzFrequencyUpperBound = 5885;
55 
56 uint32_t k6GHzFrequencyLowerBound = 5925;
57 uint32_t k6GHzFrequencyUpperBound = 7125;
58 
59 uint32_t k60GHzFrequencyLowerBound = 58320;
60 uint32_t k60GHzFrequencyUpperBound = 70200;
61 
62 constexpr uint8_t kHtMcsSetNumByte = 16;
63 constexpr uint8_t kVhtMcsSetNumByte = 8;
64 constexpr uint8_t kHeMcsSetNumByteMin = 4;
65 constexpr uint8_t kMaxStreams = 8;
66 constexpr uint8_t kVht160MhzBitMask = 0x4;
67 constexpr uint8_t kVht80p80MhzBitMask = 0x8;
68 // Some old Linux kernel versions set it to 9.
69 // 9 is OK because only 1st byte is used
70 constexpr uint8_t kHeCapPhyNumByte = 9; // Should be 11
71 constexpr uint8_t kHe160MhzBitMask = 0x8;
72 constexpr uint8_t kHe80p80MhzBitMask = 0x10;
73 
74 constexpr uint8_t kEhtCapPhyNumByte = 8;
75 constexpr uint8_t kEht320MhzBitMask = 0x2;
76 constexpr int kNl80211CmdRetryCount = 1;
77 
IsExtFeatureFlagSet(const std::vector<uint8_t> & ext_feature_flags_bytes,enum nl80211_ext_feature_index ext_feature_flag)78 bool IsExtFeatureFlagSet(
79     const std::vector<uint8_t>& ext_feature_flags_bytes,
80     enum nl80211_ext_feature_index ext_feature_flag) {
81   static_assert(NUM_NL80211_EXT_FEATURES <= SIZE_MAX,
82                 "Ext feature values doesn't fit in |size_t|");
83   // TODO:This is an unsafe cast because this assumes that the values
84   // are always unsigned!
85   size_t ext_feature_flag_idx = static_cast<size_t>(ext_feature_flag);
86   size_t ext_feature_flag_byte_pos = ext_feature_flag_idx / 8;
87   size_t ext_feature_flag_bit_pos = ext_feature_flag_idx % 8;
88   if (ext_feature_flag_byte_pos >= ext_feature_flags_bytes.size()) {
89     return false;
90   }
91   uint8_t ext_feature_flag_byte =
92       ext_feature_flags_bytes[ext_feature_flag_byte_pos];
93   return (ext_feature_flag_byte & (1U << ext_feature_flag_bit_pos));
94 }
95 }  // namespace
96 
WiphyFeatures(uint32_t feature_flags,const std::vector<uint8_t> & ext_feature_flags_bytes)97 WiphyFeatures::WiphyFeatures(uint32_t feature_flags,
98                              const std::vector<uint8_t>& ext_feature_flags_bytes)
99     : supports_random_mac_oneshot_scan(
100             feature_flags & NL80211_FEATURE_SCAN_RANDOM_MAC_ADDR),
101         supports_random_mac_sched_scan(
102             feature_flags & NL80211_FEATURE_SCHED_SCAN_RANDOM_MAC_ADDR) {
103   supports_low_span_oneshot_scan =
104       IsExtFeatureFlagSet(ext_feature_flags_bytes,
105                           NL80211_EXT_FEATURE_LOW_SPAN_SCAN);
106   supports_low_power_oneshot_scan =
107       IsExtFeatureFlagSet(ext_feature_flags_bytes,
108                           NL80211_EXT_FEATURE_LOW_POWER_SCAN);
109   supports_high_accuracy_oneshot_scan =
110       IsExtFeatureFlagSet(ext_feature_flags_bytes,
111                           NL80211_EXT_FEATURE_HIGH_ACCURACY_SCAN);
112   // TODO (b/112029045) check if sending frame at specified MCS is supported
113   supports_tx_mgmt_frame_mcs = false;
114   supports_ext_sched_scan_relative_rssi =
115       IsExtFeatureFlagSet(ext_feature_flags_bytes,
116                           NL80211_EXT_FEATURE_SCHED_SCAN_RELATIVE_RSSI);
117 }
118 
NetlinkUtils(NetlinkManager * netlink_manager)119 NetlinkUtils::NetlinkUtils(NetlinkManager* netlink_manager)
120     : netlink_manager_(netlink_manager) {
121   if (!netlink_manager_->IsStarted()) {
122     netlink_manager_->Start();
123   }
124   uint32_t protocol_features = 0;
125   supports_split_wiphy_dump_ = GetProtocolFeatures(&protocol_features) &&
126       (protocol_features & NL80211_PROTOCOL_FEATURE_SPLIT_WIPHY_DUMP);
127 }
128 
~NetlinkUtils()129 NetlinkUtils::~NetlinkUtils() {}
130 
GetWiphyIndex(uint32_t * out_wiphy_index,const std::string & iface_name)131 bool NetlinkUtils::GetWiphyIndex(uint32_t* out_wiphy_index,
132                                  const std::string& iface_name) {
133   NL80211Packet get_wiphy(
134       netlink_manager_->GetFamilyId(),
135       NL80211_CMD_GET_WIPHY,
136       netlink_manager_->GetSequenceNumber(),
137       getpid());
138   get_wiphy.AddFlag(NLM_F_DUMP);
139   int ifindex = 0;
140   if (!iface_name.empty()) {
141     ifindex = if_nametoindex(iface_name.c_str());
142     if (ifindex == 0) {
143       PLOG(ERROR) << "Can't get " << iface_name << " index";
144       return false;
145     }
146     get_wiphy.AddAttribute(NL80211Attr<uint32_t>(NL80211_ATTR_IFINDEX, ifindex));
147   }
148   vector<unique_ptr<const NL80211Packet>> response;
149   for (int i = kNl80211CmdRetryCount; i >= 0; i--) {
150       if (netlink_manager_->SendMessageAndGetResponses(get_wiphy, &response))  {
151           break;
152       } else {
153         if (i == 0) {
154             LOG(ERROR) << "NL80211_CMD_GET_WIPHY dump failed, ifindex: "
155                        << ifindex << " and name: " << iface_name.c_str();
156             return false;
157         } else {
158             LOG(INFO) << "Failed to get wiphy index, retry again";
159         }
160       }
161   }
162 
163   if (response.empty()) {
164     LOG(INFO) << "No wiphy is found";
165     return false;
166   }
167   for (auto& packet : response) {
168     if (packet->GetMessageType() == NLMSG_ERROR) {
169       LOG(ERROR) << "Receive ERROR message: "
170                  << strerror(packet->GetErrorCode());
171       return false;
172     }
173     if (packet->GetMessageType() != netlink_manager_->GetFamilyId()) {
174       LOG(ERROR) << "Wrong message type for new interface message: "
175                  << packet->GetMessageType();
176       return false;
177     }
178     if (packet->GetCommand() != NL80211_CMD_NEW_WIPHY) {
179       LOG(ERROR) << "Wrong command in response to "
180                  << "a wiphy dump request: "
181                  << static_cast<int>(packet->GetCommand());
182       return false;
183     }
184     if (!packet->GetAttributeValue(NL80211_ATTR_WIPHY, out_wiphy_index)) {
185       LOG(ERROR) << "Failed to get wiphy index from reply message";
186       return false;
187     }
188   }
189   return true;
190 }
191 
GetWiphyIndex(uint32_t * out_wiphy_index)192 bool NetlinkUtils::GetWiphyIndex(uint32_t* out_wiphy_index) {
193   return GetWiphyIndex(out_wiphy_index, "");
194 }
195 
GetInterfaces(uint32_t wiphy_index,vector<InterfaceInfo> * interface_info)196 bool NetlinkUtils::GetInterfaces(uint32_t wiphy_index,
197                                  vector<InterfaceInfo>* interface_info) {
198   NL80211Packet get_interfaces(
199       netlink_manager_->GetFamilyId(),
200       NL80211_CMD_GET_INTERFACE,
201       netlink_manager_->GetSequenceNumber(),
202       getpid());
203 
204   get_interfaces.AddFlag(NLM_F_DUMP);
205   get_interfaces.AddAttribute(
206       NL80211Attr<uint32_t>(NL80211_ATTR_WIPHY, wiphy_index));
207   vector<unique_ptr<const NL80211Packet>> response;
208   if (!netlink_manager_->SendMessageAndGetResponses(get_interfaces, &response)) {
209     LOG(ERROR) << "NL80211_CMD_GET_INTERFACE dump failed";
210     return false;
211   }
212   if (response.empty()) {
213     LOG(ERROR) << "No interface is found";
214     return false;
215   }
216   for (auto& packet : response) {
217     if (packet->GetMessageType() == NLMSG_ERROR) {
218       LOG(ERROR) << "Receive ERROR message: "
219                  << strerror(packet->GetErrorCode());
220       return false;
221     }
222     if (packet->GetMessageType() != netlink_manager_->GetFamilyId()) {
223       LOG(ERROR) << "Wrong message type for new interface message: "
224                  << packet->GetMessageType();
225       return false;
226     }
227     if (packet->GetCommand() != NL80211_CMD_NEW_INTERFACE) {
228       LOG(ERROR) << "Wrong command in response to "
229                  << "an interface dump request: "
230                  << static_cast<int>(packet->GetCommand());
231       return false;
232     }
233 
234     // In some situations, it has been observed that the kernel tells us
235     // about a pseudo interface that does not have a real netdev.  In this
236     // case, responses will have a NL80211_ATTR_WDEV, and not the expected
237     // IFNAME/IFINDEX. In this case we just skip these pseudo interfaces.
238     uint32_t if_index;
239     if (!packet->GetAttributeValue(NL80211_ATTR_IFINDEX, &if_index)) {
240       LOG(DEBUG) << "Failed to get interface index";
241       continue;
242     }
243 
244     // Today we don't check NL80211_ATTR_IFTYPE because at this point of time
245     // driver always reports that interface is in STATION mode. Even when we
246     // are asking interfaces infomation on behalf of tethering, it is still so
247     // because hostapd is supposed to set interface to AP mode later.
248 
249     string if_name;
250     if (!packet->GetAttributeValue(NL80211_ATTR_IFNAME, &if_name)) {
251       LOG(WARNING) << "Failed to get interface name";
252       continue;
253     }
254 
255     array<uint8_t, ETH_ALEN> if_mac_addr;
256     if (!packet->GetAttributeValue(NL80211_ATTR_MAC, &if_mac_addr)) {
257       LOG(WARNING) << "Failed to get interface mac address";
258       continue;
259     }
260 
261     interface_info->emplace_back(if_index, wiphy_index, if_name, if_mac_addr);
262   }
263 
264   return true;
265 }
266 
SetInterfaceMode(uint32_t interface_index,InterfaceMode mode)267 bool NetlinkUtils::SetInterfaceMode(uint32_t interface_index,
268                                     InterfaceMode mode) {
269   uint32_t set_to_mode = NL80211_IFTYPE_UNSPECIFIED;
270   if (mode == STATION_MODE) {
271     set_to_mode = NL80211_IFTYPE_STATION;
272   } else {
273     LOG(ERROR) << "Unexpected mode for interface with index: "
274                << interface_index;
275     return false;
276   }
277   NL80211Packet set_interface_mode(
278       netlink_manager_->GetFamilyId(),
279       NL80211_CMD_SET_INTERFACE,
280       netlink_manager_->GetSequenceNumber(),
281       getpid());
282   // Force an ACK response upon success.
283   set_interface_mode.AddFlag(NLM_F_ACK);
284 
285   set_interface_mode.AddAttribute(
286       NL80211Attr<uint32_t>(NL80211_ATTR_IFINDEX, interface_index));
287   set_interface_mode.AddAttribute(
288       NL80211Attr<uint32_t>(NL80211_ATTR_IFTYPE, set_to_mode));
289 
290   if (!netlink_manager_->SendMessageAndGetAck(set_interface_mode)) {
291     LOG(ERROR) << "NL80211_CMD_SET_INTERFACE failed";
292     return false;
293   }
294 
295   return true;
296 }
297 
GetProtocolFeatures(uint32_t * features)298 bool NetlinkUtils::GetProtocolFeatures(uint32_t* features) {
299   NL80211Packet get_protocol_features(
300       netlink_manager_->GetFamilyId(),
301       NL80211_CMD_GET_PROTOCOL_FEATURES,
302       netlink_manager_->GetSequenceNumber(),
303       getpid());
304   unique_ptr<const NL80211Packet> response;
305   if (!netlink_manager_->SendMessageAndGetSingleResponse(get_protocol_features,
306                                                          &response)) {
307     LOG(ERROR) << "NL80211_CMD_GET_PROTOCOL_FEATURES failed";
308     return false;
309   }
310   if (!response->GetAttributeValue(NL80211_ATTR_PROTOCOL_FEATURES, features)) {
311     LOG(ERROR) << "Failed to get NL80211_ATTR_PROTOCOL_FEATURES";
312     return false;
313   }
314   return true;
315 }
316 
GetWiphyInfo(uint32_t wiphy_index,BandInfo * out_band_info,ScanCapabilities * out_scan_capabilities,WiphyFeatures * out_wiphy_features)317 bool NetlinkUtils::GetWiphyInfo(
318     uint32_t wiphy_index,
319     BandInfo* out_band_info,
320     ScanCapabilities* out_scan_capabilities,
321     WiphyFeatures* out_wiphy_features) {
322   NL80211Packet get_wiphy(
323       netlink_manager_->GetFamilyId(),
324       NL80211_CMD_GET_WIPHY,
325       netlink_manager_->GetSequenceNumber(),
326       getpid());
327   get_wiphy.AddAttribute(NL80211Attr<uint32_t>(NL80211_ATTR_WIPHY, wiphy_index));
328   if (supports_split_wiphy_dump_) {
329     get_wiphy.AddFlagAttribute(NL80211_ATTR_SPLIT_WIPHY_DUMP);
330     get_wiphy.AddFlag(NLM_F_DUMP);
331   }
332   vector<unique_ptr<const NL80211Packet>> response;
333   for (int i = kNl80211CmdRetryCount; i >= 0; i--) {
334       if (netlink_manager_->SendMessageAndGetResponses(get_wiphy, &response))  {
335           break;
336       } else {
337         if (i == 0) {
338             LOG(ERROR) << "NL80211_CMD_GET_WIPHY dump failed";
339             return false;
340         } else {
341             LOG(INFO) << "Failed to get wiphy info, retry again";
342         }
343       }
344   }
345 
346   vector<NL80211Packet> packet_per_wiphy;
347   if (supports_split_wiphy_dump_) {
348     if (!MergePacketsForSplitWiphyDump(response, &packet_per_wiphy)) {
349       LOG(WARNING) << "Failed to merge responses from split wiphy dump";
350     }
351   } else {
352     for (auto& packet : response) {
353       packet_per_wiphy.push_back(std::move(*(packet.release())));
354     }
355   }
356 
357   for (const auto& packet : packet_per_wiphy) {
358     uint32_t current_wiphy_index;
359     if (!packet.GetAttributeValue(NL80211_ATTR_WIPHY, &current_wiphy_index) ||
360         // Not the wihpy we requested.
361         current_wiphy_index != wiphy_index) {
362       continue;
363     }
364     if (ParseWiphyInfoFromPacket(packet, out_band_info,
365                                  out_scan_capabilities, out_wiphy_features)) {
366       return true;
367     }
368   }
369 
370   LOG(ERROR) << "Failed to find expected wiphy info "
371              << "from NL80211_CMD_GET_WIPHY responses";
372   return false;
373 }
374 
ParseWiphyInfoFromPacket(const NL80211Packet & packet,BandInfo * out_band_info,ScanCapabilities * out_scan_capabilities,WiphyFeatures * out_wiphy_features)375 bool NetlinkUtils::ParseWiphyInfoFromPacket(
376     const NL80211Packet& packet,
377     BandInfo* out_band_info,
378     ScanCapabilities* out_scan_capabilities,
379     WiphyFeatures* out_wiphy_features) {
380   if (packet.GetCommand() != NL80211_CMD_NEW_WIPHY) {
381     LOG(ERROR) << "Wrong command in response to a get wiphy request: "
382                << static_cast<int>(packet.GetCommand());
383     return false;
384   }
385   if (!ParseBandInfo(&packet, out_band_info) ||
386       !ParseScanCapabilities(&packet, out_scan_capabilities)) {
387     return false;
388   }
389   uint32_t feature_flags;
390   if (!packet.GetAttributeValue(NL80211_ATTR_FEATURE_FLAGS,
391                                  &feature_flags)) {
392     LOG(ERROR) << "Failed to get NL80211_ATTR_FEATURE_FLAGS";
393     return false;
394   }
395   std::vector<uint8_t> ext_feature_flags_bytes;
396   if (!packet.GetAttributeValue(NL80211_ATTR_EXT_FEATURES,
397                                 &ext_feature_flags_bytes)) {
398     LOG(WARNING) << "Failed to get NL80211_ATTR_EXT_FEATURES";
399   }
400   *out_wiphy_features = WiphyFeatures(feature_flags,
401                                       ext_feature_flags_bytes);
402   return true;
403 }
404 
ParseScanCapabilities(const NL80211Packet * const packet,ScanCapabilities * out_scan_capabilities)405 bool NetlinkUtils::ParseScanCapabilities(
406     const NL80211Packet* const packet,
407     ScanCapabilities* out_scan_capabilities) {
408   uint8_t max_num_scan_ssids;
409   if (!packet->GetAttributeValue(NL80211_ATTR_MAX_NUM_SCAN_SSIDS,
410                                    &max_num_scan_ssids)) {
411     LOG(ERROR) << "Failed to get the capacity of maximum number of scan ssids";
412     return false;
413   }
414 
415   uint8_t max_num_sched_scan_ssids;
416   if (!packet->GetAttributeValue(NL80211_ATTR_MAX_NUM_SCHED_SCAN_SSIDS,
417                                  &max_num_sched_scan_ssids)) {
418     LOG(ERROR) << "Failed to get the capacity of "
419                << "maximum number of scheduled scan ssids";
420     return false;
421   }
422 
423   // Use default value 0 for scan plan capabilities if attributes are missing.
424   uint32_t max_num_scan_plans = 0;
425   packet->GetAttributeValue(NL80211_ATTR_MAX_NUM_SCHED_SCAN_PLANS,
426                             &max_num_scan_plans);
427   uint32_t max_scan_plan_interval = 0;
428   packet->GetAttributeValue(NL80211_ATTR_MAX_SCAN_PLAN_INTERVAL,
429                             &max_scan_plan_interval);
430   uint32_t max_scan_plan_iterations = 0;
431   packet->GetAttributeValue(NL80211_ATTR_MAX_SCAN_PLAN_ITERATIONS,
432                             &max_scan_plan_iterations);
433 
434   uint8_t max_match_sets;
435   if (!packet->GetAttributeValue(NL80211_ATTR_MAX_MATCH_SETS,
436                                    &max_match_sets)) {
437     LOG(ERROR) << "Failed to get the capacity of maximum number of match set"
438                << "of a scheduled scan";
439     return false;
440   }
441   *out_scan_capabilities = ScanCapabilities(max_num_scan_ssids,
442                                             max_num_sched_scan_ssids,
443                                             max_match_sets,
444                                             max_num_scan_plans,
445                                             max_scan_plan_interval,
446                                             max_scan_plan_iterations);
447   return true;
448 }
449 
ParseBandInfo(const NL80211Packet * const packet,BandInfo * out_band_info)450 bool NetlinkUtils::ParseBandInfo(const NL80211Packet* const packet,
451                                  BandInfo* out_band_info) {
452 
453   NL80211NestedAttr bands_attr(0);
454   if (!packet->GetAttribute(NL80211_ATTR_WIPHY_BANDS, &bands_attr)) {
455     LOG(ERROR) << "Failed to get NL80211_ATTR_WIPHY_BANDS";
456     return false;
457   }
458   vector<NL80211NestedAttr> bands;
459   if (!bands_attr.GetListOfNestedAttributes(&bands)) {
460     LOG(ERROR) << "Failed to get bands within NL80211_ATTR_WIPHY_BANDS";
461     return false;
462   }
463 
464   *out_band_info = BandInfo();
465   for (auto& band : bands) {
466     NL80211NestedAttr freqs_attr(0);
467     if (band.GetAttribute(NL80211_BAND_ATTR_FREQS, &freqs_attr)) {
468       handleBandFreqAttributes(freqs_attr, out_band_info);
469     }
470     if (band.HasAttribute(NL80211_BAND_ATTR_HT_CAPA)) {
471       out_band_info->is_80211n_supported = true;
472     }
473     if (band.HasAttribute(NL80211_BAND_ATTR_VHT_CAPA)) {
474       out_band_info->is_80211ac_supported = true;
475     }
476 
477     NL80211NestedAttr iftype_data_attr(0);
478     if (band.GetAttribute(NL80211_BAND_ATTR_IFTYPE_DATA,
479         &iftype_data_attr)) {
480       ParseIfTypeDataAttributes(iftype_data_attr, out_band_info);
481     }
482     ParseHtVhtPhyCapabilities(band, out_band_info);
483   }
484 
485   return true;
486 }
487 
ParseIfTypeDataAttributes(const NL80211NestedAttr & iftype_data_attr,BandInfo * out_band_info)488 void NetlinkUtils::ParseIfTypeDataAttributes(
489     const NL80211NestedAttr& iftype_data_attr,
490     BandInfo* out_band_info) {
491   vector<NL80211NestedAttr> attrs;
492   if (!iftype_data_attr.GetListOfNestedAttributes(&attrs) || attrs.empty()) {
493     LOG(ERROR) << "Failed to get the list of attributes under iftype_data_attr";
494     return;
495   }
496 
497   NL80211NestedAttr attr = attrs[0];
498   if (attr.HasAttribute(NL80211_BAND_IFTYPE_ATTR_HE_CAP_PHY)) {
499     out_band_info->is_80211ax_supported = true;
500     ParseHeCapPhyAttribute(attr, out_band_info);
501   }
502   if (attr.HasAttribute(NL80211_BAND_IFTYPE_ATTR_HE_CAP_MCS_SET)) {
503     ParseHeMcsSetAttribute(attr, out_band_info);
504   }
505   if (attr.HasAttribute(NL80211_BAND_IFTYPE_ATTR_EHT_CAP_PHY)) {
506     out_band_info->is_80211be_supported = true;
507     ParseEhtCapPhyAttribute(attr, out_band_info);
508   }
509   return;
510 }
511 
handleBandFreqAttributes(const NL80211NestedAttr & freqs_attr,BandInfo * out_band_info)512 void NetlinkUtils::handleBandFreqAttributes(const NL80211NestedAttr& freqs_attr,
513                                             BandInfo* out_band_info) {
514   vector<NL80211NestedAttr> freqs;
515   if (!freqs_attr.GetListOfNestedAttributes(&freqs)) {
516     LOG(ERROR) << "Failed to get frequency attributes";
517     return;
518   }
519 
520   for (auto& freq : freqs) {
521     uint32_t frequency_value;
522     if (!freq.GetAttributeValue(NL80211_FREQUENCY_ATTR_FREQ,
523                                 &frequency_value)) {
524       LOG(DEBUG) << "Failed to get NL80211_FREQUENCY_ATTR_FREQ";
525       continue;
526     }
527     // Channel is disabled in current regulatory domain.
528     if (freq.HasAttribute(NL80211_FREQUENCY_ATTR_DISABLED)) {
529       continue;
530     }
531 
532     if (frequency_value > k2GHzFrequencyLowerBound &&
533         frequency_value < k2GHzFrequencyUpperBound) {
534       out_band_info->band_2g.push_back(frequency_value);
535     } else if (frequency_value > k5GHzFrequencyLowerBound &&
536         frequency_value <= k5GHzFrequencyUpperBound) {
537       // If this is an available/usable DFS frequency, we should save it to
538       // DFS frequencies list.
539       uint32_t dfs_state;
540       if (freq.GetAttributeValue(NL80211_FREQUENCY_ATTR_DFS_STATE,
541                                  &dfs_state) &&
542         (dfs_state == NL80211_DFS_AVAILABLE ||
543             dfs_state == NL80211_DFS_USABLE)) {
544         out_band_info->band_dfs.push_back(frequency_value);
545         continue;
546       }
547 
548       // Put non-dfs passive-only channels into the dfs category.
549       // This aligns with what framework always assumes.
550       if (freq.HasAttribute(NL80211_FREQUENCY_ATTR_NO_IR)) {
551         out_band_info->band_dfs.push_back(frequency_value);
552         continue;
553       }
554 
555       // Otherwise, this is a regular 5g frequency.
556       out_band_info->band_5g.push_back(frequency_value);
557     } else if (frequency_value > k6GHzFrequencyLowerBound &&
558         frequency_value < k6GHzFrequencyUpperBound) {
559       out_band_info->band_6g.push_back(frequency_value);
560     } else if (frequency_value >= k60GHzFrequencyLowerBound &&
561         frequency_value < k60GHzFrequencyUpperBound) {
562       out_band_info->band_60g.push_back(frequency_value);
563     }
564   }
565 }
566 
ParseHtVhtPhyCapabilities(const NL80211NestedAttr & band,BandInfo * out_band_info)567 void NetlinkUtils::ParseHtVhtPhyCapabilities(const NL80211NestedAttr& band,
568                                              BandInfo* out_band_info) {
569   ParseHtMcsSetAttribute(band, out_band_info);
570   ParseVhtMcsSetAttribute(band, out_band_info);
571   ParseVhtCapAttribute(band, out_band_info);
572 }
573 
ParseHtMcsSetAttribute(const NL80211NestedAttr & band,BandInfo * out_band_info)574 void NetlinkUtils::ParseHtMcsSetAttribute(const NL80211NestedAttr& band,
575                                           BandInfo* out_band_info) {
576   vector<uint8_t> ht_mcs_set;
577   if (!band.GetAttributeValue(NL80211_BAND_ATTR_HT_MCS_SET, &ht_mcs_set)) {
578     return;
579   }
580   if (ht_mcs_set.size() < kHtMcsSetNumByte) {
581     LOG(ERROR) << "HT MCS set size is incorrect";
582     return;
583   }
584   pair<uint32_t, uint32_t> max_streams_ht = ParseHtMcsSet(ht_mcs_set);
585   out_band_info->max_tx_streams = std::max(out_band_info->max_tx_streams,
586                                            max_streams_ht.first);
587   out_band_info->max_rx_streams = std::max(out_band_info->max_rx_streams,
588                                            max_streams_ht.second);
589 }
590 
ParseHtMcsSet(const vector<uint8_t> & ht_mcs_set)591 pair<uint32_t, uint32_t> NetlinkUtils::ParseHtMcsSet(
592     const vector<uint8_t>& ht_mcs_set) {
593   uint32_t max_rx_streams = 1;
594   for (int i = 4; i >= 1; i--) {
595     if (ht_mcs_set[i - 1] > 0) {
596       max_rx_streams = i;
597       break;
598     }
599   }
600 
601   uint32_t max_tx_streams = max_rx_streams;
602   uint8_t supported_tx_mcs_set = ht_mcs_set[12];
603   uint8_t tx_mcs_set_defined = supported_tx_mcs_set & 0x1;
604   uint8_t tx_rx_mcs_set_not_equal = (supported_tx_mcs_set >> 1) & 0x1;
605   if (tx_mcs_set_defined && tx_rx_mcs_set_not_equal) {
606     uint8_t max_nss_tx_field_value = (supported_tx_mcs_set >> 2) & 0x3;
607     // The maximum number of Tx streams is 1 more than the field value.
608     max_tx_streams = max_nss_tx_field_value + 1;
609   }
610 
611   return std::make_pair(max_tx_streams, max_rx_streams);
612 }
613 
ParseVhtMcsSetAttribute(const NL80211NestedAttr & band,BandInfo * out_band_info)614 void NetlinkUtils::ParseVhtMcsSetAttribute(const NL80211NestedAttr& band,
615                                            BandInfo* out_band_info) {
616   vector<uint8_t> vht_mcs_set;
617   if (!band.GetAttributeValue(NL80211_BAND_ATTR_VHT_MCS_SET, &vht_mcs_set)) {
618     return;
619   }
620   if (vht_mcs_set.size() < kVhtMcsSetNumByte) {
621     LOG(ERROR) << "VHT MCS set size is incorrect";
622     return;
623   }
624   uint16_t vht_mcs_set_rx = (vht_mcs_set[1] << 8) | vht_mcs_set[0];
625   uint32_t max_rx_streams_vht = ParseMcsMap(vht_mcs_set_rx);
626   uint16_t vht_mcs_set_tx = (vht_mcs_set[5] << 8) | vht_mcs_set[4];
627   uint32_t max_tx_streams_vht = ParseMcsMap(vht_mcs_set_tx);
628   out_band_info->max_tx_streams = std::max(out_band_info->max_tx_streams,
629                                            max_tx_streams_vht);
630   out_band_info->max_rx_streams = std::max(out_band_info->max_rx_streams,
631                                            max_rx_streams_vht);
632 }
633 
ParseHeMcsSetAttribute(const NL80211NestedAttr & attribute,BandInfo * out_band_info)634 void NetlinkUtils::ParseHeMcsSetAttribute(const NL80211NestedAttr& attribute,
635                                           BandInfo* out_band_info) {
636   vector<uint8_t> he_mcs_set;
637   if (!attribute.GetAttributeValue(
638       NL80211_BAND_IFTYPE_ATTR_HE_CAP_MCS_SET,
639       &he_mcs_set)) {
640     LOG(ERROR) << " HE MCS set is not found ";
641     return;
642   }
643   if (he_mcs_set.size() < kHeMcsSetNumByteMin) {
644     LOG(ERROR) << "HE MCS set size is incorrect";
645     return;
646   }
647   uint16_t he_mcs_map_rx = (he_mcs_set[1] << 8) | he_mcs_set[0];
648   uint32_t max_rx_streams_he = ParseMcsMap(he_mcs_map_rx);
649   uint16_t he_mcs_map_tx = (he_mcs_set[3] << 8) | he_mcs_set[2];
650   uint32_t max_tx_streams_he = ParseMcsMap(he_mcs_map_tx);
651   out_band_info->max_tx_streams = std::max(out_band_info->max_tx_streams,
652                                            max_tx_streams_he);
653   out_band_info->max_rx_streams = std::max(out_band_info->max_rx_streams,
654                                            max_rx_streams_he);
655 }
656 
ParseMcsMap(uint16_t mcs_map)657 uint32_t NetlinkUtils::ParseMcsMap(uint16_t mcs_map)
658 {
659   uint32_t max_nss = 1;
660   for (int i = kMaxStreams; i >= 1; i--) {
661     uint16_t stream_map = (mcs_map >> ((i - 1) * 2)) & 0x3;
662     // 0x3 means unsupported
663     if (stream_map != 0x3) {
664       max_nss = i;
665       break;
666     }
667   }
668   return max_nss;
669 }
670 
ParseVhtCapAttribute(const NL80211NestedAttr & band,BandInfo * out_band_info)671 void NetlinkUtils::ParseVhtCapAttribute(const NL80211NestedAttr& band,
672                                         BandInfo* out_band_info) {
673   uint32_t vht_cap;
674   if (!band.GetAttributeValue(NL80211_BAND_ATTR_VHT_CAPA, &vht_cap)) {
675     return;
676   }
677 
678   if (vht_cap & kVht160MhzBitMask) {
679     out_band_info->is_160_mhz_supported = true;
680   }
681   if (vht_cap & kVht80p80MhzBitMask) {
682     out_band_info->is_80p80_mhz_supported = true;
683   }
684 }
685 
ParseHeCapPhyAttribute(const NL80211NestedAttr & attribute,BandInfo * out_band_info)686 void NetlinkUtils::ParseHeCapPhyAttribute(const NL80211NestedAttr& attribute,
687                                           BandInfo* out_band_info) {
688 
689   vector<uint8_t> he_cap_phy;
690   if (!attribute.GetAttributeValue(
691       NL80211_BAND_IFTYPE_ATTR_HE_CAP_PHY,
692       &he_cap_phy)) {
693     LOG(ERROR) << " HE CAP PHY is not found";
694     return;
695   }
696 
697   if (he_cap_phy.size() < kHeCapPhyNumByte) {
698     LOG(ERROR) << "HE Cap PHY size is incorrect";
699     return;
700   }
701   if (he_cap_phy[0] & kHe160MhzBitMask) {
702     out_band_info->is_160_mhz_supported = true;
703   }
704   if (he_cap_phy[0] & kHe80p80MhzBitMask) {
705     out_band_info->is_80p80_mhz_supported = true;
706   }
707 }
708 
ParseEhtCapPhyAttribute(const NL80211NestedAttr & attribute,BandInfo * out_band_info)709 void NetlinkUtils::ParseEhtCapPhyAttribute(const NL80211NestedAttr& attribute,
710                                            BandInfo* out_band_info) {
711   vector<uint8_t> eht_cap_phy;
712   if (!attribute.GetAttributeValue(
713       NL80211_BAND_IFTYPE_ATTR_EHT_CAP_PHY,
714       &eht_cap_phy)) {
715     LOG(ERROR) << " EHT CAP PHY is not found";
716     return;
717   }
718 
719   if (eht_cap_phy.size() < kEhtCapPhyNumByte) {
720     LOG(ERROR) << "EHT Cap PHY size is incorrect";
721     return;
722   }
723   if (eht_cap_phy[0] & kEht320MhzBitMask) {
724     out_band_info->is_320_mhz_supported = true;
725   }
726 }
727 
GetStationInfo(uint32_t interface_index,const array<uint8_t,ETH_ALEN> & mac_address,StationInfo * out_station_info)728 bool NetlinkUtils::GetStationInfo(uint32_t interface_index,
729                                   const array<uint8_t, ETH_ALEN>& mac_address,
730                                   StationInfo* out_station_info) {
731   NL80211Packet get_station(
732       netlink_manager_->GetFamilyId(),
733       NL80211_CMD_GET_STATION,
734       netlink_manager_->GetSequenceNumber(),
735       getpid());
736   get_station.AddAttribute(NL80211Attr<uint32_t>(NL80211_ATTR_IFINDEX,
737                                                  interface_index));
738   get_station.AddAttribute(NL80211Attr<array<uint8_t, ETH_ALEN>>(
739       NL80211_ATTR_MAC, mac_address));
740 
741   unique_ptr<const NL80211Packet> response;
742   if (!netlink_manager_->SendMessageAndGetSingleResponse(get_station,
743                                                          &response)) {
744     LOG(ERROR) << "NL80211_CMD_GET_STATION failed";
745     return false;
746   }
747   if (response->GetCommand() != NL80211_CMD_NEW_STATION) {
748     LOG(ERROR) << "Wrong command in response to a get station request: "
749                << static_cast<int>(response->GetCommand());
750     return false;
751   }
752   NL80211NestedAttr sta_info(0);
753   if (!response->GetAttribute(NL80211_ATTR_STA_INFO, &sta_info)) {
754     LOG(ERROR) << "Failed to get NL80211_ATTR_STA_INFO";
755     return false;
756   }
757   int32_t tx_good, tx_bad;
758   if (!sta_info.GetAttributeValue(NL80211_STA_INFO_TX_PACKETS, &tx_good)) {
759     LOG(ERROR) << "Failed to get NL80211_STA_INFO_TX_PACKETS";
760     return false;
761   }
762   if (!sta_info.GetAttributeValue(NL80211_STA_INFO_TX_FAILED, &tx_bad)) {
763     LOG(ERROR) << "Failed to get NL80211_STA_INFO_TX_FAILED";
764     return false;
765   }
766   int8_t current_rssi;
767   if (!sta_info.GetAttributeValue(NL80211_STA_INFO_SIGNAL, &current_rssi)) {
768     LOG(ERROR) << "Failed to get NL80211_STA_INFO_SIGNAL";
769     return false;
770   }
771   NL80211NestedAttr tx_bitrate_attr(0);
772   uint32_t tx_bitrate = 0;
773   if (sta_info.GetAttribute(NL80211_STA_INFO_TX_BITRATE,
774                             &tx_bitrate_attr)) {
775     if (!tx_bitrate_attr.GetAttributeValue(NL80211_RATE_INFO_BITRATE32,
776                                          &tx_bitrate)) {
777       // Return invalid tx rate to avoid breaking the get station cmd
778       tx_bitrate = 0;
779     }
780   }
781   NL80211NestedAttr rx_bitrate_attr(0);
782   uint32_t rx_bitrate = 0;
783   if (sta_info.GetAttribute(NL80211_STA_INFO_RX_BITRATE,
784                             &rx_bitrate_attr)) {
785     if (!rx_bitrate_attr.GetAttributeValue(NL80211_RATE_INFO_BITRATE32,
786                                          &rx_bitrate)) {
787       // Return invalid rx rate to avoid breaking the get station cmd
788       rx_bitrate = 0;
789     }
790   }
791   *out_station_info = StationInfo(tx_good, tx_bad, tx_bitrate, current_rssi, rx_bitrate);
792   return true;
793 }
794 
795 // This is a helper function for merging split NL80211_CMD_NEW_WIPHY packets.
796 // For example:
797 // First NL80211_CMD_NEW_WIPHY has attribute A with payload 0x1234.
798 // Second NL80211_CMD_NEW_WIPHY has attribute A with payload 0x5678.
799 // The generated NL80211_CMD_NEW_WIPHY will have attribute A with
800 // payload 0x12345678.
801 // NL80211_ATTR_WIPHY, NL80211_ATTR_IFINDEX, and NL80211_ATTR_WDEV
802 // are used for filtering packets so we know which packets should
803 // be merged together.
MergePacketsForSplitWiphyDump(const vector<unique_ptr<const NL80211Packet>> & split_dump_info,vector<NL80211Packet> * packet_per_wiphy)804 bool NetlinkUtils::MergePacketsForSplitWiphyDump(
805     const vector<unique_ptr<const NL80211Packet>>& split_dump_info,
806     vector<NL80211Packet>* packet_per_wiphy) {
807   map<uint32_t, map<int, BaseNL80211Attr>> attr_by_wiphy_and_id;
808 
809   // Construct the map using input packets.
810   for (const auto& packet : split_dump_info) {
811     uint32_t wiphy_index;
812     if (!packet->GetAttributeValue(NL80211_ATTR_WIPHY, &wiphy_index)) {
813       LOG(ERROR) << "Failed to get NL80211_ATTR_WIPHY from wiphy split dump";
814       return false;
815     }
816     vector<BaseNL80211Attr> attributes;
817     if (!packet->GetAllAttributes(&attributes)) {
818       return false;
819     }
820     for (auto& attr : attributes) {
821       int attr_id = attr.GetAttributeId();
822       if (attr_id != NL80211_ATTR_WIPHY &&
823           attr_id != NL80211_ATTR_IFINDEX &&
824               attr_id != NL80211_ATTR_WDEV) {
825           auto attr_id_and_attr =
826               attr_by_wiphy_and_id[wiphy_index].find(attr_id);
827           if (attr_id_and_attr == attr_by_wiphy_and_id[wiphy_index].end()) {
828             attr_by_wiphy_and_id[wiphy_index].
829                 insert(make_pair(attr_id, std::move(attr)));
830           } else {
831             attr_id_and_attr->second.Merge(attr);
832           }
833       }
834     }
835   }
836 
837   // Generate output packets using the constructed map.
838   for (const auto& wiphy_and_attributes : attr_by_wiphy_and_id) {
839     NL80211Packet new_wiphy(0, NL80211_CMD_NEW_WIPHY, 0, 0);
840     new_wiphy.AddAttribute(
841         NL80211Attr<uint32_t>(NL80211_ATTR_WIPHY, wiphy_and_attributes.first));
842     for (const auto& attr : wiphy_and_attributes.second) {
843       new_wiphy.AddAttribute(attr.second);
844     }
845     packet_per_wiphy->emplace_back(std::move(new_wiphy));
846   }
847   return true;
848 }
849 
GetCountryCode(string * out_country_code)850 bool NetlinkUtils::GetCountryCode(string* out_country_code) {
851   NL80211Packet get_country_code(
852       netlink_manager_->GetFamilyId(),
853       NL80211_CMD_GET_REG,
854       netlink_manager_->GetSequenceNumber(),
855       getpid());
856   unique_ptr<const NL80211Packet> response;
857   if (!netlink_manager_->SendMessageAndGetSingleResponse(get_country_code,
858                                                          &response)) {
859     LOG(ERROR) << "NL80211_CMD_GET_REG failed";
860     return false;
861   }
862   if (!response->GetAttributeValue(NL80211_ATTR_REG_ALPHA2, out_country_code)) {
863     LOG(ERROR) << "Get NL80211_ATTR_REG_ALPHA2 failed";
864     return false;
865   }
866   return true;
867 }
868 
SendMgmtFrame(uint32_t interface_index,const vector<uint8_t> & frame,int32_t mcs,uint64_t * out_cookie)869 bool NetlinkUtils::SendMgmtFrame(uint32_t interface_index,
870     const vector<uint8_t>& frame, int32_t mcs, uint64_t* out_cookie) {
871 
872   NL80211Packet send_mgmt_frame(
873       netlink_manager_->GetFamilyId(),
874       NL80211_CMD_FRAME,
875       netlink_manager_->GetSequenceNumber(),
876       getpid());
877 
878   send_mgmt_frame.AddAttribute(
879       NL80211Attr<uint32_t>(NL80211_ATTR_IFINDEX, interface_index));
880 
881   send_mgmt_frame.AddAttribute(
882       NL80211Attr<vector<uint8_t>>(NL80211_ATTR_FRAME, frame));
883 
884   if (mcs >= 0) {
885     // TODO (b/112029045) if mcs >= 0, add MCS attribute
886   }
887 
888   unique_ptr<const NL80211Packet> response;
889   if (!netlink_manager_->SendMessageAndGetSingleResponse(
890       send_mgmt_frame, &response)) {
891     LOG(ERROR) << "NL80211_CMD_FRAME failed";
892     return false;
893   }
894 
895   if (!response->GetAttributeValue(NL80211_ATTR_COOKIE, out_cookie)) {
896     LOG(ERROR) << "Get NL80211_ATTR_COOKIE failed";
897     return false;
898   }
899 
900   return true;
901 }
902 
SubscribeMlmeEvent(uint32_t interface_index,MlmeEventHandler * handler)903 void NetlinkUtils::SubscribeMlmeEvent(uint32_t interface_index,
904                                       MlmeEventHandler* handler) {
905   netlink_manager_->SubscribeMlmeEvent(interface_index, handler);
906 }
907 
UnsubscribeMlmeEvent(uint32_t interface_index)908 void NetlinkUtils::UnsubscribeMlmeEvent(uint32_t interface_index) {
909   netlink_manager_->UnsubscribeMlmeEvent(interface_index);
910 }
911 
SubscribeRegDomainChange(uint32_t wiphy_index,OnRegDomainChangedHandler handler)912 void NetlinkUtils::SubscribeRegDomainChange(
913     uint32_t wiphy_index,
914     OnRegDomainChangedHandler handler) {
915   netlink_manager_->SubscribeRegDomainChange(wiphy_index, handler);
916 }
917 
UnsubscribeRegDomainChange(uint32_t wiphy_index)918 void NetlinkUtils::UnsubscribeRegDomainChange(uint32_t wiphy_index) {
919   netlink_manager_->UnsubscribeRegDomainChange(wiphy_index);
920 }
921 
SubscribeStationEvent(uint32_t interface_index,OnStationEventHandler handler)922 void NetlinkUtils::SubscribeStationEvent(uint32_t interface_index,
923                                          OnStationEventHandler handler) {
924   netlink_manager_->SubscribeStationEvent(interface_index, handler);
925 }
926 
UnsubscribeStationEvent(uint32_t interface_index)927 void NetlinkUtils::UnsubscribeStationEvent(uint32_t interface_index) {
928   netlink_manager_->UnsubscribeStationEvent(interface_index);
929 }
930 
SubscribeChannelSwitchEvent(uint32_t interface_index,OnChannelSwitchEventHandler handler)931 void NetlinkUtils::SubscribeChannelSwitchEvent(uint32_t interface_index,
932                                          OnChannelSwitchEventHandler handler) {
933   netlink_manager_->SubscribeChannelSwitchEvent(interface_index, handler);
934 }
935 
UnsubscribeChannelSwitchEvent(uint32_t interface_index)936 void NetlinkUtils::UnsubscribeChannelSwitchEvent(uint32_t interface_index) {
937   netlink_manager_->UnsubscribeChannelSwitchEvent(interface_index);
938 }
939 
SubscribeFrameTxStatusEvent(uint32_t interface_index,OnFrameTxStatusEventHandler handler)940 void NetlinkUtils::SubscribeFrameTxStatusEvent(
941     uint32_t interface_index, OnFrameTxStatusEventHandler handler) {
942   netlink_manager_->SubscribeFrameTxStatusEvent(interface_index, handler);
943 }
944 
UnsubscribeFrameTxStatusEvent(uint32_t interface_index)945 void NetlinkUtils::UnsubscribeFrameTxStatusEvent(uint32_t interface_index) {
946   netlink_manager_->UnsubscribeFrameTxStatusEvent(interface_index);
947 }
948 
949 }  // namespace wificond
950 }  // namespace android
951