| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| #include "guest/commands/wifi_setup/cmd.h" |
| |
| namespace cvd { |
| |
| Cmd::Cmd() : msg_(nlmsg_alloc()) {} |
| |
| Cmd::Cmd(nlmsghdr* h) : msg_(nlmsg_convert(h)) {} |
| |
| Cmd::Cmd(nl_msg* h) { |
| nlmsg_get(h); |
| msg_ = h; |
| } |
| |
| Cmd::~Cmd() { |
| for (auto& msg : responses_) { |
| nlmsg_free(msg); |
| } |
| nlmsg_free(msg_); |
| } |
| |
| bool Cmd::OnResponse(nl_msg* msg) { |
| // nlmsg_get increases refcount on msg, but does not return the msg |
| // so we can't exactly use it as an argument to unique_ptr. |
| nlmsg_get(msg); |
| responses_.emplace_back(msg); |
| auto hdr = nlmsg_hdr(msg); |
| |
| // Kernel documentation seems to be a bit misleading on this topic saying: |
| // |
| // In multipart messages (multiple nlmsghdr headers with associated |
| // payload in one byte stream) the first and all following headers have |
| // the NLM_F_MULTI flag set, except for the last header which has the type |
| // NLMSG_DONE. |
| // |
| // In theory, that would make processing multi-part messages simple, but in |
| // practice this does not seem to be true. Specifying exit criteria solely on |
| // NLM_F_MULTI flag setting will block some, if not all calls that dump |
| // NL80211 wifi interfaces for example. |
| if (!(hdr->nlmsg_flags & NLM_F_MULTI) || (hdr->nlmsg_type == NLMSG_DONE) || |
| (hdr->nlmsg_type == NLMSG_ERROR)) { |
| std::lock_guard<std::mutex> lock(ready_mutex_); |
| ready_signal_.notify_all(); |
| return true; |
| } |
| |
| return false; |
| } |
| |
| const std::vector<nl_msg*> Cmd::Responses() const { |
| WaitComplete(); |
| return responses_; |
| } |
| |
| void Cmd::WaitComplete() const { |
| std::unique_lock<std::mutex> lock(ready_mutex_); |
| ready_signal_.wait(lock, [this]() { return responses_.size() > 0; }); |
| } |
| |
| } // namespace cvd |