2 * This file is part of DisOrder.
3 * Copyright (C) 2004-9, 2013 Richard Kettlewell
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 /** @file lib/log.c @brief Errors and logging
20 * All messages are initially emitted by one of the four functions
21 * below. disorder_debug() is generally invoked via D() so that
22 * mostly you just do a test rather than a complete subroutine call.
24 * Messages are dispatched via @ref log_default. This defaults to @ref
25 * log_stderr. daemonize() will turn off @ref log_stderr and use @ref
28 * disorder_fatal() will call exitfn() with a nonzero status. The
29 * default value is exit(), but it should be set to _exit() anywhere
30 * but the 'main line' of the program, to guarantee that exit() gets
31 * called at most once.
34 #define NO_MEMORY_ALLOCATION
35 /* because the memory allocation functions report errors */
40 #include <sys/types.h>
45 # include <sys/time.h>
48 # include <sys/socket.h>
59 /** @brief Definition of a log output */
61 /** @brief Function to call */
62 void (*fn
)(int pri
, const char *msg
, void *user
);
63 /** @brief User data */
67 /** @brief Function to call on a fatal error
69 * This is normally @c exit() but in the presence of @c fork() it
70 * sometimes gets set to @c _exit(). */
71 void (*exitfn
)(int) attribute((noreturn
)) = exit
;
73 /** @brief Debug flag */
76 /** @brief Program name */
79 /** @brief Filename for debug messages */
80 const char *debug_filename
;
82 /** @brief Set to include timestamps in log messages */
85 /** @brief Line number for debug messages */
88 /** @brief Pointer to chosen log output structure */
89 struct log_output
*log_default
= &log_stderr
;
91 /** @brief Filename to debug for */
92 static const char *debug_only
;
94 /** @brief Construct log line, encoding special characters
96 * We might be receiving things in any old encoding, or binary rubbish
97 * in no encoding at all, so escape anything we don't like the look
98 * of. We limit the log message to a kilobyte.
100 static void format(char buffer
[], size_t bufsize
, const char *fmt
, va_list ap
) {
106 if(byte_vsnprintf(t
, sizeof t
, fmt
, ap
) < 0) {
107 strcpy(t
, "[byte_vsnprintf failed: ");
108 strncat(t
, fmt
, sizeof t
- strlen(t
) - 1);
111 while((ch
= (unsigned char)*p
++)) {
112 if(ch
>= ' ' && ch
<= 126) {
113 if(n
< bufsize
) buffer
[n
++] = ch
;
115 if(n
< bufsize
) buffer
[n
++] = '\\';
116 if(n
< bufsize
) buffer
[n
++] = '0' + ((ch
>> 6) & 7);
117 if(n
< bufsize
) buffer
[n
++] = '0' + ((ch
>> 3) & 7);
118 if(n
< bufsize
) buffer
[n
++] = '0' + ((ch
>> 0) & 7);
126 /** @brief Log to a file
127 * @param pri Message priority (as per syslog)
128 * @param msg Messagge to log
129 * @param user The @c FILE @c * to log to or NULL for @c stderr
131 static void logfp(int pri
, const char *msg
, void *user
) {
133 FILE *fp
= user ? user
: stderr
;
134 /* ...because stderr is not a constant so we can't initialize log_stderr
141 gettimeofday(&tv
, 0);
142 tm
= localtime(&tv
.tv_sec
);
143 strftime(timebuf
, sizeof timebuf
, "%Y-%m-%d %H:%M:%S %Z", tm
);
144 fprintf(fp
, "%s: ", timebuf
);
147 fprintf(fp
, "%s: ", progname
);
149 fputs("ERROR: ", fp
);
150 else if(pri
< LOG_DEBUG
)
154 if(!(debug_only
= getenv("DISORDER_DEBUG_ONLY")))
157 gettimeofday(&tv
, 0);
159 while(!strncmp(p
, "../", 3)) p
+= 3;
160 if(*debug_only
&& strcmp(p
, debug_only
))
162 fprintf(fp
, "%llu.%06lu: %s:%d: ",
163 (unsigned long long)tv
.tv_sec
, (unsigned long)tv
.tv_usec
,
171 /** @brief Log to syslog */
172 static void logsyslog(int pri
, const char *msg
,
173 void attribute((unused
)) *user
) {
175 syslog(pri
, "%s", msg
);
177 syslog(pri
, "%s:%d: %s", debug_filename
, debug_lineno
, msg
);
181 /** @brief Log output that writes to @c stderr */
182 struct log_output log_stderr
= { logfp
, 0 };
185 /** @brief Log output that sends to syslog */
186 struct log_output log_syslog
= { logsyslog
, 0 };
189 /** @brief Format and log a message */
190 static void vlogger(int pri
, const char *fmt
, va_list ap
) {
193 format(buffer
, sizeof buffer
, fmt
, ap
);
194 log_default
->fn(pri
, buffer
, log_default
->user
);
197 /** @brief Format and log a message */
198 static void logger(int pri
, const char *fmt
, ...) {
202 vlogger(pri
, fmt
, ap
);
206 /** @brief Format and log a message
207 * @param pri Message priority (as per syslog)
208 * @param ec Error class
209 * @param fmt Format string
210 * @param errno_value Errno value to include as a string, or 0
211 * @param ap Argument list
213 void elog(int pri
, enum error_class ec
, int errno_value
, const char *fmt
, va_list ap
) {
218 vlogger(pri
, fmt
, ap
);
220 memset(buffer
, 0, sizeof buffer
);
221 byte_vsnprintf(buffer
, sizeof buffer
, fmt
, ap
);
222 buffer
[sizeof buffer
- 1] = 0;
223 logger(pri
, "%s: %s", buffer
,
224 format_error(ec
, errno_value
, errbuf
, sizeof errbuf
));
228 /** @brief Log an error and quit
230 * If @c ${DISORDER_FATAL_ABORT} is defined (as anything) then the process
231 * is aborted, so you can get a backtrace.
233 void disorder_fatal(int errno_value
, const char *msg
, ...) {
237 elog(LOG_CRIT
, ec_errno
, errno_value
, msg
, ap
);
239 if(getenv("DISORDER_FATAL_ABORT")) abort();
240 exitfn(EXIT_FAILURE
);
243 /** @brief Log an error and quit
245 * If @c ${DISORDER_FATAL_ABORT} is defined (as anything) then the process
246 * is aborted, so you can get a backtrace.
248 void disorder_fatal_ec(enum error_class ec
, int errno_value
, const char *msg
, ...) {
252 elog(LOG_CRIT
, ec
, errno_value
, msg
, ap
);
254 if(getenv("DISORDER_FATAL_ABORT")) abort();
255 exitfn(EXIT_FAILURE
);
258 /** @brief Log an error */
259 void disorder_error(int errno_value
, const char *msg
, ...) {
263 elog(LOG_ERR
, ec_errno
, errno_value
, msg
, ap
);
267 /** @brief Log an error */
268 void disorder_error_ec(enum error_class ec
, int errno_value
, const char *msg
, ...) {
272 elog(LOG_ERR
, ec
, errno_value
, msg
, ap
);
276 /** @brief Log an informational message */
277 void disorder_info(const char *msg
, ...) {
281 elog(LOG_INFO
, ec_none
, 0, msg
, ap
);
285 /** @brief Log a debug message */
286 void disorder_debug(const char *msg
, ...) {
290 vlogger(LOG_DEBUG
, msg
, ap
);
294 /** @brief Set the program name from @c argc */
295 void set_progname(char **argv
) {
296 if((progname
= strrchr(argv
[0], '/')))
302 /** @brief Format an error string
303 * @param ec Error class
304 * @param err Error code (interpretation defined by @p ec)
305 * @param buffer Output buffer
306 * @param bufsize Size of output buffer
307 * @return Pointer to error string
309 * The return value may or may not be @p buffer.
311 #pragma GCC diagnostic ignored "-Wunused-parameter"
312 const char *format_error(enum error_class ec
, int err
, char buffer
[], size_t bufsize
) {
315 return strerror(err
);
317 return gai_strerror(err
);