1 /**
2 * Copyright © 2016 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
17 #pragma once
18
19 #include <systemd/sd-journal.h>
20
21 #include <phosphor-logging/sdjournal.hpp>
22 #include <sdbusplus/server/transaction.hpp>
23
24 #include <tuple>
25 #include <type_traits>
26
27 namespace phosphor
28 {
29
30 namespace logging
31 {
32
33 /** @enum level
34 * @brief Enum for priority level
35 */
36 enum class level
37 {
38 EMERG = LOG_EMERG,
39 ALERT = LOG_ALERT,
40 CRIT = LOG_CRIT,
41 ERR = LOG_ERR,
42 WARNING = LOG_WARNING,
43 NOTICE = LOG_NOTICE,
44 INFO = LOG_INFO,
45 DEBUG = LOG_DEBUG,
46 };
47
48 namespace details
49 {
50
51 /** @fn prio()
52 * @brief Prepend PRIORITY= to the input priority string.
53 * This is required by sd_journal_send().
54 * @tparam L - Priority level
55 */
56 template <level L>
prio()57 constexpr auto prio()
58 {
59 constexpr const char* prio_str = "PRIORITY=%d";
60 constexpr const auto prio_tuple = std::make_tuple(prio_str, L);
61 return prio_tuple;
62 }
63
64 /** @fn helper_log()
65 * @brief Helper function for details::log(). Log request to journal.
66 * @tparam T - Type of tuple
67 * @tparam I - std::integer_sequence of indexes (0..N) for each tuple element
68 * @param[in] e - Tuple containing the data to be logged
69 * @param[unnamed] - std::integer_sequence of tuple's index values
70 */
71 template <typename T, size_t... I>
helper_log(T && e,std::integer_sequence<size_t,I...>)72 void helper_log(T&& e, std::integer_sequence<size_t, I...>)
73 {
74 // https://www.freedesktop.org/software/systemd/man/sd_journal_print.html
75 // TODO: Re-enable call through interface for testing (or move the code
76 // into the body of the object).
77 sd_journal_send(std::get<I>(std::forward<T>(e))..., NULL);
78 }
79
80 /** @fn details::log()
81 * @brief Implementation of logging::log() function.
82 * Send request msg and size to helper funct to log it to the journal.
83 * @tparam T - Type of tuple
84 * @param[in] e - Tuple containing the data to be logged
85 */
86 template <typename T>
log(T && e)87 void log(T&& e)
88 {
89 constexpr auto e_size = std::tuple_size<std::decay_t<T>>::value;
90 helper_log(std::forward<T>(e), std::make_index_sequence<e_size>{});
91 }
92
93 } // namespace details
94
95 template <class T>
96 struct is_char_ptr_argtype :
97 std::integral_constant<
98 bool,
99 (std::is_pointer<typename std::decay<T>::type>::value &&
100 std::is_same<typename std::remove_cv<typename std::remove_pointer<
101 typename std::decay<T>::type>::type>::type,
102 char>::value)>
103 {};
104
105 template <class T>
106 struct is_printf_argtype :
107 std::integral_constant<
108 bool,
109 (std::is_integral<typename std::remove_reference<T>::type>::value ||
110 std::is_enum<typename std::remove_reference<T>::type>::value ||
111 std::is_floating_point<
112 typename std::remove_reference<T>::type>::value ||
113 std::is_pointer<typename std::decay<T>::type>::value)>
114 {};
115
116 template <bool...>
117 struct bool_pack;
118
119 template <bool... bs>
120 using all_true = std::is_same<bool_pack<bs..., true>, bool_pack<true, bs...>>;
121
122 /** @fn entry()
123 * @brief Pack each format string entry as a tuple to be able to validate
124 * the string and parameters when multiple entries are passed to be logged.
125 * @tparam Arg - Types of first argument
126 * @tparam Args - Types of remaining arguments
127 * @param[in] arg - First metadata string of form VAR=value where
128 * VAR is the variable name in uppercase and
129 * value is of any size and format
130 * @param[in] args - Remaining metadata strings
131 */
132 template <typename Arg, typename... Args>
entry(Arg && arg,Args &&...args)133 constexpr auto entry(Arg&& arg, Args&&... args)
134 {
135 static_assert(is_char_ptr_argtype<Arg>::value,
136 "bad argument type: use char*");
137 static_assert(all_true<is_printf_argtype<Args>::value...>::value,
138 "bad argument type: use string.c_str() if needed");
139 return std::make_tuple(std::forward<Arg>(arg), std::forward<Args>(args)...);
140 }
141
142 /** @fn log()
143 * @brief Log message to systemd journal
144 * @tparam L - Priority level
145 * @param[in] msg - Message to be logged in C-string format
146 * @param[in] entry - Metadata fields to be added to the message
147 * @details Usage: log<level::XX>(const char*, entry(*format), entry()...);
148 * @example log<level::DEBUG>(
149 * "Simple Example");
150 * char msg_str[] = "File not found";
151 * log<level::DEBUG>(
152 * msg_str,
153 * entry("MY_METADATA=%s_%x, name, number));
154 */
155 template <level L, typename Msg, typename... Entry>
log(Msg msg,Entry...e)156 void log(Msg msg, Entry... e)
157 {
158 static_assert((std::is_same<const char*, std::decay_t<Msg>>::value ||
159 std::is_same<char*, std::decay_t<Msg>>::value),
160 "First parameter must be a C-string.");
161
162 constexpr const char* msg_str = "MESSAGE=%s";
163 const auto msg_tuple = std::make_tuple(msg_str, std::forward<Msg>(msg));
164
165 constexpr auto transactionStr = "TRANSACTION_ID=%llu";
166 auto transactionId = sdbusplus::server::transaction::get_id();
167
168 auto log_tuple = std::tuple_cat(details::prio<L>(), msg_tuple,
169 entry(transactionStr, transactionId),
170 std::forward<Entry>(e)...);
171 details::log(log_tuple);
172 }
173
174 } // namespace logging
175
176 } // namespace phosphor
177