1 // Copyright 2020 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "base/fuchsia/scoped_fx_logger.h"
6
7 #include <lib/component/incoming/cpp/protocol.h>
8 #include <lib/fdio/directory.h>
9 #include <stdio.h>
10
11 #include <string_view>
12
13 #include "base/command_line.h"
14 #include "base/files/file_path.h"
15 #include "base/fuchsia/fuchsia_component_connect.h"
16 #include "base/fuchsia/fuchsia_logging.h"
17 #include "base/process/process.h"
18 #include "base/threading/platform_thread.h"
19
20 namespace base {
21
22 ScopedFxLogger::ScopedFxLogger() = default;
23 ScopedFxLogger::~ScopedFxLogger() = default;
24
25 ScopedFxLogger::ScopedFxLogger(ScopedFxLogger&& other) = default;
26 ScopedFxLogger& ScopedFxLogger::operator=(ScopedFxLogger&& other) = default;
27
28 // static
CreateForProcess(std::vector<std::string_view> tags)29 ScopedFxLogger ScopedFxLogger::CreateForProcess(
30 std::vector<std::string_view> tags) {
31 // CHECK()ing or LOG()ing inside this function is safe, since it is only
32 // called to initialize logging, not during individual logging operations.
33
34 auto log_sink_client_end = component::Connect<fuchsia_logger::LogSink>();
35 if (log_sink_client_end.is_error()) {
36 LOG(ERROR) << FidlConnectionErrorMessage(log_sink_client_end);
37 return {};
38 }
39
40 // Rather than relying on automatic LogSink attribution via COMPONENT_NAME,
41 // prepend a tag based on the calling process' name. COMPONENT_NAME may be
42 // mis-attributed, in some Component configurations, to a parent or caller
43 // component, from which the process' LogSink service is routed.
44 std::string program_name = base::CommandLine::ForCurrentProcess()
45 ->GetProgram()
46 .BaseName()
47 .AsUTF8Unsafe();
48 tags.insert(tags.begin(), program_name);
49
50 return CreateFromLogSink(std::move(log_sink_client_end.value()),
51 std::move(tags));
52 }
53
54 // static
CreateFromLogSink(fidl::ClientEnd<fuchsia_logger::LogSink> log_sink_client_end,std::vector<std::string_view> tags)55 ScopedFxLogger ScopedFxLogger::CreateFromLogSink(
56 fidl::ClientEnd<fuchsia_logger::LogSink> log_sink_client_end,
57 std::vector<std::string_view> tags) {
58 // CHECK()ing or LOG()ing inside this function is safe, since it is only
59 // called to initialize logging, not during individual logging operations.
60
61 // Attempts to create a kernel socket object should never fail.
62 zx::socket local, remote;
63 zx_status_t socket_status =
64 zx::socket::create(ZX_SOCKET_DATAGRAM, &local, &remote);
65 ZX_CHECK(socket_status == ZX_OK, socket_status)
66 << "zx_socket_create() failed";
67
68 // ConnectStructured() may fail if e.g. the LogSink has disconnected already.
69 fidl::SyncClient log_sink(std::move(log_sink_client_end));
70 auto connect_structured_result =
71 log_sink->ConnectStructured(std::move(remote));
72 if (connect_structured_result.is_error()) {
73 ZX_LOG(ERROR, connect_structured_result.error_value().status())
74 << "ConnectStructured() failed";
75 return {};
76 }
77
78 return ScopedFxLogger(std::move(tags), std::move(local));
79 }
80
LogMessage(std::string_view file,uint32_t line_number,std::string_view msg,FuchsiaLogSeverity severity)81 void ScopedFxLogger::LogMessage(std::string_view file,
82 uint32_t line_number,
83 std::string_view msg,
84 FuchsiaLogSeverity severity) {
85 if (!socket_.is_valid())
86 return;
87
88 // It is not safe to use e.g. CHECK() or LOG() macros here, since those
89 // may result in reentrancy if this instance is used for routing process-
90 // global logs to the system logger.
91
92 fuchsia_syslog::LogBuffer buffer;
93 buffer.BeginRecord(severity, cpp17::string_view(file.data(), file.size()),
94 line_number, cpp17::string_view(msg.data(), msg.size()),
95 socket_.borrow(), 0, base::Process::Current().Pid(),
96 base::PlatformThread::CurrentId());
97 for (const auto& tag : tags_) {
98 buffer.WriteKeyValue("tag", tag);
99 }
100 if (!buffer.FlushRecord())
101 fprintf(stderr, "fuchsia_syslog.LogBuffer.FlushRecord() failed\n");
102 }
103
ScopedFxLogger(std::vector<std::string_view> tags,zx::socket socket)104 ScopedFxLogger::ScopedFxLogger(std::vector<std::string_view> tags,
105 zx::socket socket)
106 : tags_(tags.begin(), tags.end()), socket_(std::move(socket)) {}
107
108 } // namespace base
109