| 1 | /* |
| 2 | * This file is part of DisOrder. |
| 3 | * Copyright (C) 2004-9, 2013 Richard Kettlewell |
| 4 | * |
| 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. |
| 9 | * |
| 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. |
| 14 | * |
| 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/>. |
| 17 | */ |
| 18 | /** @file lib/log.c @brief Errors and logging |
| 19 | * |
| 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. |
| 23 | * |
| 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 |
| 26 | * log_syslog instead. |
| 27 | * |
| 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. |
| 32 | */ |
| 33 | |
| 34 | #define NO_MEMORY_ALLOCATION |
| 35 | /* because the memory allocation functions report errors */ |
| 36 | |
| 37 | #include "common.h" |
| 38 | |
| 39 | #include <errno.h> |
| 40 | #include <sys/types.h> |
| 41 | #if HAVE_SYSLOG_H |
| 42 | # include <syslog.h> |
| 43 | #endif |
| 44 | #if HAVE_SYS_TIME_H |
| 45 | # include <sys/time.h> |
| 46 | #endif |
| 47 | #if HAVE_SYS_SOCKET_H |
| 48 | # include <sys/socket.h> |
| 49 | #endif |
| 50 | #if HAVE_NETDB_H |
| 51 | # include <netdb.h> |
| 52 | #endif |
| 53 | #include <time.h> |
| 54 | |
| 55 | #include "log.h" |
| 56 | #include "disorder.h" |
| 57 | #include "printf.h" |
| 58 | |
| 59 | /** @brief Definition of a log output */ |
| 60 | struct log_output { |
| 61 | /** @brief Function to call */ |
| 62 | void (*fn)(int pri, const char *msg, void *user); |
| 63 | /** @brief User data */ |
| 64 | void *user; |
| 65 | }; |
| 66 | |
| 67 | /** @brief Function to call on a fatal error |
| 68 | * |
| 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; |
| 72 | |
| 73 | /** @brief Debug flag */ |
| 74 | int debugging; |
| 75 | |
| 76 | /** @brief Program name */ |
| 77 | const char *progname; |
| 78 | |
| 79 | /** @brief Filename for debug messages */ |
| 80 | const char *debug_filename; |
| 81 | |
| 82 | /** @brief Set to include timestamps in log messages */ |
| 83 | int logdate; |
| 84 | |
| 85 | /** @brief Line number for debug messages */ |
| 86 | int debug_lineno; |
| 87 | |
| 88 | /** @brief Pointer to chosen log output structure */ |
| 89 | struct log_output *log_default = &log_stderr; |
| 90 | |
| 91 | /** @brief Filename to debug for */ |
| 92 | static const char *debug_only; |
| 93 | |
| 94 | /** @brief Construct log line, encoding special characters |
| 95 | * |
| 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. |
| 99 | */ |
| 100 | static void format(char buffer[], size_t bufsize, const char *fmt, va_list ap) { |
| 101 | char t[1024]; |
| 102 | const char *p; |
| 103 | int ch; |
| 104 | size_t n = 0; |
| 105 | |
| 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); |
| 109 | } |
| 110 | p = t; |
| 111 | while((ch = (unsigned char)*p++)) { |
| 112 | if(ch >= ' ' && ch <= 126) { |
| 113 | if(n < bufsize) buffer[n++] = ch; |
| 114 | } else { |
| 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); |
| 119 | } |
| 120 | } |
| 121 | if(n >= bufsize) |
| 122 | n = bufsize - 1; |
| 123 | buffer[n] = 0; |
| 124 | } |
| 125 | |
| 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 |
| 130 | */ |
| 131 | static void logfp(int pri, const char *msg, void *user) { |
| 132 | struct timeval tv; |
| 133 | FILE *fp = user ? user : stderr; |
| 134 | /* ...because stderr is not a constant so we can't initialize log_stderr |
| 135 | * sanely */ |
| 136 | const char *p; |
| 137 | |
| 138 | if(logdate) { |
| 139 | char timebuf[64]; |
| 140 | struct tm *tm; |
| 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); |
| 145 | } |
| 146 | if(progname) |
| 147 | fprintf(fp, "%s: ", progname); |
| 148 | if(pri <= LOG_ERR) |
| 149 | fputs("ERROR: ", fp); |
| 150 | else if(pri < LOG_DEBUG) |
| 151 | fputs("INFO: ", fp); |
| 152 | else { |
| 153 | if(!debug_only) { |
| 154 | if(!(debug_only = getenv("DISORDER_DEBUG_ONLY"))) |
| 155 | debug_only = ""; |
| 156 | } |
| 157 | gettimeofday(&tv, 0); |
| 158 | p = debug_filename; |
| 159 | while(!strncmp(p, "../", 3)) p += 3; |
| 160 | if(*debug_only && strcmp(p, debug_only)) |
| 161 | return; |
| 162 | fprintf(fp, "%llu.%06lu: %s:%d: ", |
| 163 | (unsigned long long)tv.tv_sec, (unsigned long)tv.tv_usec, |
| 164 | p, debug_lineno); |
| 165 | } |
| 166 | fputs(msg, fp); |
| 167 | fputc('\n', fp); |
| 168 | } |
| 169 | |
| 170 | #if HAVE_SYSLOG_H |
| 171 | /** @brief Log to syslog */ |
| 172 | static void logsyslog(int pri, const char *msg, |
| 173 | void attribute((unused)) *user) { |
| 174 | if(pri < LOG_DEBUG) |
| 175 | syslog(pri, "%s", msg); |
| 176 | else |
| 177 | syslog(pri, "%s:%d: %s", debug_filename, debug_lineno, msg); |
| 178 | } |
| 179 | #endif |
| 180 | |
| 181 | /** @brief Log output that writes to @c stderr */ |
| 182 | struct log_output log_stderr = { logfp, 0 }; |
| 183 | |
| 184 | #if HAVE_SYSLOG_H |
| 185 | /** @brief Log output that sends to syslog */ |
| 186 | struct log_output log_syslog = { logsyslog, 0 }; |
| 187 | #endif |
| 188 | |
| 189 | /** @brief Format and log a message */ |
| 190 | static void vlogger(int pri, const char *fmt, va_list ap) { |
| 191 | char buffer[1024]; |
| 192 | |
| 193 | format(buffer, sizeof buffer, fmt, ap); |
| 194 | log_default->fn(pri, buffer, log_default->user); |
| 195 | } |
| 196 | |
| 197 | /** @brief Format and log a message */ |
| 198 | static void logger(int pri, const char *fmt, ...) { |
| 199 | va_list ap; |
| 200 | |
| 201 | va_start(ap, fmt); |
| 202 | vlogger(pri, fmt, ap); |
| 203 | va_end(ap); |
| 204 | } |
| 205 | |
| 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 |
| 212 | */ |
| 213 | void elog(int pri, enum error_class ec, int errno_value, const char *fmt, va_list ap) { |
| 214 | char buffer[1024]; |
| 215 | char errbuf[1024]; |
| 216 | |
| 217 | if(errno_value == 0) |
| 218 | vlogger(pri, fmt, ap); |
| 219 | else { |
| 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)); |
| 225 | } |
| 226 | } |
| 227 | |
| 228 | /** @brief Log an error and quit |
| 229 | * |
| 230 | * If @c ${DISORDER_FATAL_ABORT} is defined (as anything) then the process |
| 231 | * is aborted, so you can get a backtrace. |
| 232 | */ |
| 233 | void disorder_fatal(int errno_value, const char *msg, ...) { |
| 234 | va_list ap; |
| 235 | |
| 236 | va_start(ap, msg); |
| 237 | elog(LOG_CRIT, ec_errno, errno_value, msg, ap); |
| 238 | va_end(ap); |
| 239 | if(getenv("DISORDER_FATAL_ABORT")) abort(); |
| 240 | exitfn(EXIT_FAILURE); |
| 241 | } |
| 242 | |
| 243 | /** @brief Log an error and quit |
| 244 | * |
| 245 | * If @c ${DISORDER_FATAL_ABORT} is defined (as anything) then the process |
| 246 | * is aborted, so you can get a backtrace. |
| 247 | */ |
| 248 | void disorder_fatal_ec(enum error_class ec, int errno_value, const char *msg, ...) { |
| 249 | va_list ap; |
| 250 | |
| 251 | va_start(ap, msg); |
| 252 | elog(LOG_CRIT, ec, errno_value, msg, ap); |
| 253 | va_end(ap); |
| 254 | if(getenv("DISORDER_FATAL_ABORT")) abort(); |
| 255 | exitfn(EXIT_FAILURE); |
| 256 | } |
| 257 | |
| 258 | /** @brief Log an error */ |
| 259 | void disorder_error(int errno_value, const char *msg, ...) { |
| 260 | va_list ap; |
| 261 | |
| 262 | va_start(ap, msg); |
| 263 | elog(LOG_ERR, ec_errno, errno_value, msg, ap); |
| 264 | va_end(ap); |
| 265 | } |
| 266 | |
| 267 | /** @brief Log an error */ |
| 268 | void disorder_error_ec(enum error_class ec, int errno_value, const char *msg, ...) { |
| 269 | va_list ap; |
| 270 | |
| 271 | va_start(ap, msg); |
| 272 | elog(LOG_ERR, ec, errno_value, msg, ap); |
| 273 | va_end(ap); |
| 274 | } |
| 275 | |
| 276 | /** @brief Log an informational message */ |
| 277 | void disorder_info(const char *msg, ...) { |
| 278 | va_list ap; |
| 279 | |
| 280 | va_start(ap, msg); |
| 281 | elog(LOG_INFO, ec_none, 0, msg, ap); |
| 282 | va_end(ap); |
| 283 | } |
| 284 | |
| 285 | /** @brief Log a debug message */ |
| 286 | void disorder_debug(const char *msg, ...) { |
| 287 | va_list ap; |
| 288 | |
| 289 | va_start(ap, msg); |
| 290 | vlogger(LOG_DEBUG, msg, ap); |
| 291 | va_end(ap); |
| 292 | } |
| 293 | |
| 294 | /** @brief Set the program name from @c argc */ |
| 295 | void set_progname(char **argv) { |
| 296 | if((progname = strrchr(argv[0], '/'))) |
| 297 | ++progname; |
| 298 | else |
| 299 | progname = argv[0]; |
| 300 | } |
| 301 | |
| 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 |
| 308 | * |
| 309 | * The return value may or may not be @p buffer. |
| 310 | */ |
| 311 | #pragma GCC diagnostic ignored "-Wunused-parameter" |
| 312 | const char *format_error(enum error_class ec, int err, char buffer[], size_t bufsize) { |
| 313 | switch(ec) { |
| 314 | default: |
| 315 | return strerror(err); |
| 316 | case ec_getaddrinfo: |
| 317 | return gai_strerror(err); |
| 318 | case ec_none: |
| 319 | return "(none)"; |
| 320 | } |
| 321 | } |
| 322 | |
| 323 | /* |
| 324 | Local Variables: |
| 325 | c-basic-offset:2 |
| 326 | comment-column:40 |
| 327 | End: |
| 328 | */ |