xref: /openbmc/phosphor-logging/extensions/openpower-pels/journal.cpp (revision 9fd25af597865f7e69bfb4f15338782370e61baa)
1 /**
2  * Copyright © 2023 IBM Corporation
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 #include "journal.hpp"
17 
18 #include "util.hpp"
19 
20 #include <phosphor-logging/lg2.hpp>
21 
22 namespace openpower::pels
23 {
24 
25 using namespace phosphor::logging;
26 
27 /**
28  * @class JournalCloser
29  *
30  * Closes the journal on destruction
31  */
32 class JournalCloser
33 {
34   public:
35     JournalCloser() = delete;
36     JournalCloser(const JournalCloser&) = delete;
37     JournalCloser(JournalCloser&&) = delete;
38     JournalCloser& operator=(const JournalCloser&) = delete;
39     JournalCloser& operator=(JournalCloser&&) = delete;
40 
41     explicit JournalCloser(sd_journal* journal) : journal{journal} {}
42 
43     ~JournalCloser()
44     {
45         sd_journal_close(journal);
46     }
47 
48   private:
49     sd_journal* journal{nullptr};
50 };
51 
52 void Journal::sync() const
53 {
54     auto start = std::chrono::steady_clock::now();
55 
56     util::journalSync();
57 
58     auto end = std::chrono::steady_clock::now();
59     auto duration =
60         std::chrono::duration_cast<std::chrono::milliseconds>(end - start);
61 
62     if (duration.count() > 100)
63     {
64         lg2::info("Journal sync took {DURATION}ms", "DURATION",
65                   duration.count());
66     }
67 }
68 
69 std::vector<std::string> Journal::getMessages(const std::string& syslogID,
70                                               size_t maxMessages) const
71 {
72     // The message registry JSON schema will also fail if a zero is in the JSON
73     if (0 == maxMessages)
74     {
75         lg2::error(
76             "maxMessages value of zero passed into Journal::getMessages");
77         return std::vector<std::string>{};
78     }
79 
80     sd_journal* journal;
81     int rc = sd_journal_open(&journal, SD_JOURNAL_LOCAL_ONLY);
82     if (rc < 0)
83     {
84         throw std::runtime_error{
85             std::string{"Failed to open journal: "} + strerror(-rc)};
86     }
87 
88     JournalCloser closer{journal};
89 
90     if (!syslogID.empty())
91     {
92         std::string match{"SYSLOG_IDENTIFIER=" + syslogID};
93 
94         rc = sd_journal_add_match(journal, match.c_str(), 0);
95         if (rc < 0)
96         {
97             throw std::runtime_error{
98                 std::string{"Failed to add journal match: "} + strerror(-rc)};
99         }
100     }
101 
102     // Loop through matching entries from newest to oldest
103     std::vector<std::string> messages;
104     messages.reserve(maxMessages);
105     std::string sID, pid, message, timeStamp, line;
106 
107     SD_JOURNAL_FOREACH_BACKWARDS(journal)
108     {
109         timeStamp = getTimeStamp(journal);
110         sID = getFieldValue(journal, "SYSLOG_IDENTIFIER");
111         pid = getFieldValue(journal, "_PID");
112         message = getFieldValue(journal, "MESSAGE");
113 
114         line = timeStamp + " " + sID + "[" + pid + "]: " + message;
115         messages.emplace(messages.begin(), line);
116 
117         if (messages.size() >= maxMessages)
118         {
119             break;
120         }
121     }
122 
123     return messages;
124 }
125 
126 std::string Journal::getFieldValue(sd_journal* journal,
127                                    const std::string& field) const
128 {
129     std::string value{};
130 
131     const void* data{nullptr};
132     size_t length{0};
133     int rc = sd_journal_get_data(journal, field.c_str(), &data, &length);
134     if (rc < 0)
135     {
136         if (-rc == ENOENT)
137         {
138             // Current entry does not include this field; return empty value
139             return value;
140         }
141         else
142         {
143             throw std::runtime_error{
144                 std::string{"Failed to read journal entry field: "} +
145                 strerror(-rc)};
146         }
147     }
148 
149     // Get value from field data.  Field data in format "FIELD=value".
150     std::string dataString{static_cast<const char*>(data), length};
151     std::string::size_type pos = dataString.find('=');
152     if ((pos != std::string::npos) && ((pos + 1) < dataString.size()))
153     {
154         // Value is substring after the '='
155         value = dataString.substr(pos + 1);
156     }
157 
158     return value;
159 }
160 
161 std::string Journal::getTimeStamp(sd_journal* journal) const
162 {
163     // Get realtime (wallclock) timestamp of current journal entry.  The
164     // timestamp is in microseconds since the epoch.
165     uint64_t usec{0};
166     int rc = sd_journal_get_realtime_usec(journal, &usec);
167     if (rc < 0)
168     {
169         throw std::runtime_error{
170             std::string{"Failed to get journal entry timestamp: "} +
171             strerror(-rc)};
172     }
173 
174     // Convert to number of seconds since the epoch
175     time_t secs = usec / 1000000;
176 
177     // Convert seconds to tm struct required by strftime()
178     struct tm* timeStruct = gmtime(&secs);
179     if (timeStruct == nullptr)
180     {
181         throw std::runtime_error{
182             std::string{"Invalid journal entry timestamp: "} + strerror(errno)};
183     }
184 
185     // Convert tm struct into a date/time string
186     char timeStamp[80];
187     strftime(timeStamp, sizeof(timeStamp), "%b %d %H:%M:%S", timeStruct);
188 
189     return timeStamp;
190 }
191 
192 } // namespace openpower::pels
193