| 1 | /* |
| 2 | * This file is part of DisOrder. |
| 3 | * Copyright (C) 2004-2008 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 <syslog.h> |
| 41 | #include <sys/time.h> |
| 42 | #include <time.h> |
| 43 | |
| 44 | #include "log.h" |
| 45 | #include "disorder.h" |
| 46 | #include "printf.h" |
| 47 | |
| 48 | /** @brief Definition of a log output */ |
| 49 | struct log_output { |
| 50 | /** @brief Function to call */ |
| 51 | void (*fn)(int pri, const char *msg, void *user); |
| 52 | /** @brief User data */ |
| 53 | void *user; |
| 54 | }; |
| 55 | |
| 56 | /** @brief Function to call on a fatal error |
| 57 | * |
| 58 | * This is normally @c exit() but in the presence of @c fork() it |
| 59 | * sometimes gets set to @c _exit(). */ |
| 60 | void (*exitfn)(int) attribute((noreturn)) = exit; |
| 61 | |
| 62 | /** @brief Debug flag */ |
| 63 | int debugging; |
| 64 | |
| 65 | /** @brief Program name */ |
| 66 | const char *progname; |
| 67 | |
| 68 | /** @brief Filename for debug messages */ |
| 69 | const char *debug_filename; |
| 70 | |
| 71 | /** @brief Set to include timestamps in log messages */ |
| 72 | int logdate; |
| 73 | |
| 74 | /** @brief Line number for debug messages */ |
| 75 | int debug_lineno; |
| 76 | |
| 77 | /** @brief Pointer to chosen log output structure */ |
| 78 | struct log_output *log_default = &log_stderr; |
| 79 | |
| 80 | /** @brief Filename to debug for */ |
| 81 | static const char *debug_only; |
| 82 | |
| 83 | /** @brief Construct log line, encoding special characters |
| 84 | * |
| 85 | * We might be receiving things in any old encoding, or binary rubbish |
| 86 | * in no encoding at all, so escape anything we don't like the look |
| 87 | * of. We limit the log message to a kilobyte. |
| 88 | */ |
| 89 | static void format(char buffer[], size_t bufsize, const char *fmt, va_list ap) { |
| 90 | char t[1024]; |
| 91 | const char *p; |
| 92 | int ch; |
| 93 | size_t n = 0; |
| 94 | |
| 95 | if(byte_vsnprintf(t, sizeof t, fmt, ap) < 0) { |
| 96 | strcpy(t, "[byte_vsnprintf failed: "); |
| 97 | strncat(t, fmt, sizeof t - strlen(t) - 1); |
| 98 | } |
| 99 | p = t; |
| 100 | while((ch = (unsigned char)*p++)) { |
| 101 | if(ch >= ' ' && ch <= 126) { |
| 102 | if(n < bufsize) buffer[n++] = ch; |
| 103 | } else { |
| 104 | if(n < bufsize) buffer[n++] = '\\'; |
| 105 | if(n < bufsize) buffer[n++] = '0' + ((ch >> 6) & 7); |
| 106 | if(n < bufsize) buffer[n++] = '0' + ((ch >> 3) & 7); |
| 107 | if(n < bufsize) buffer[n++] = '0' + ((ch >> 0) & 7); |
| 108 | } |
| 109 | } |
| 110 | if(n >= bufsize) |
| 111 | n = bufsize - 1; |
| 112 | buffer[n] = 0; |
| 113 | } |
| 114 | |
| 115 | /** @brief Log to a file |
| 116 | * @param pri Message priority (as per syslog) |
| 117 | * @param msg Messagge to log |
| 118 | * @param user The @c FILE @c * to log to or NULL for @c stderr |
| 119 | */ |
| 120 | static void logfp(int pri, const char *msg, void *user) { |
| 121 | struct timeval tv; |
| 122 | FILE *fp = user ? user : stderr; |
| 123 | /* ...because stderr is not a constant so we can't initialize log_stderr |
| 124 | * sanely */ |
| 125 | const char *p; |
| 126 | |
| 127 | if(logdate) { |
| 128 | char timebuf[64]; |
| 129 | struct tm *tm; |
| 130 | gettimeofday(&tv, 0); |
| 131 | tm = localtime(&tv.tv_sec); |
| 132 | strftime(timebuf, sizeof timebuf, "%Y-%m-%d %H:%M:%S %Z", tm); |
| 133 | fprintf(fp, "%s: ", timebuf); |
| 134 | } |
| 135 | if(progname) |
| 136 | fprintf(fp, "%s: ", progname); |
| 137 | if(pri <= LOG_ERR) |
| 138 | fputs("ERROR: ", fp); |
| 139 | else if(pri < LOG_DEBUG) |
| 140 | fputs("INFO: ", fp); |
| 141 | else { |
| 142 | if(!debug_only) { |
| 143 | if(!(debug_only = getenv("DISORDER_DEBUG_ONLY"))) |
| 144 | debug_only = ""; |
| 145 | } |
| 146 | gettimeofday(&tv, 0); |
| 147 | p = debug_filename; |
| 148 | while(!strncmp(p, "../", 3)) p += 3; |
| 149 | if(*debug_only && strcmp(p, debug_only)) |
| 150 | return; |
| 151 | fprintf(fp, "%llu.%06lu: %s:%d: ", |
| 152 | (unsigned long long)tv.tv_sec, (unsigned long)tv.tv_usec, |
| 153 | p, debug_lineno); |
| 154 | } |
| 155 | fputs(msg, fp); |
| 156 | fputc('\n', fp); |
| 157 | } |
| 158 | |
| 159 | /** @brief Log to syslog */ |
| 160 | static void logsyslog(int pri, const char *msg, |
| 161 | void attribute((unused)) *user) { |
| 162 | if(pri < LOG_DEBUG) |
| 163 | syslog(pri, "%s", msg); |
| 164 | else |
| 165 | syslog(pri, "%s:%d: %s", debug_filename, debug_lineno, msg); |
| 166 | } |
| 167 | |
| 168 | /** @brief Log output that writes to @c stderr */ |
| 169 | struct log_output log_stderr = { logfp, 0 }; |
| 170 | |
| 171 | /** @brief Log output that sends to syslog */ |
| 172 | struct log_output log_syslog = { logsyslog, 0 }; |
| 173 | |
| 174 | /** @brief Format and log a message */ |
| 175 | static void vlogger(int pri, const char *fmt, va_list ap) { |
| 176 | char buffer[1024]; |
| 177 | |
| 178 | format(buffer, sizeof buffer, fmt, ap); |
| 179 | log_default->fn(pri, buffer, log_default->user); |
| 180 | } |
| 181 | |
| 182 | /** @brief Format and log a message */ |
| 183 | static void logger(int pri, const char *fmt, ...) { |
| 184 | va_list ap; |
| 185 | |
| 186 | va_start(ap, fmt); |
| 187 | vlogger(pri, fmt, ap); |
| 188 | va_end(ap); |
| 189 | } |
| 190 | |
| 191 | /** @brief Format and log a message |
| 192 | * @param pri Message priority (as per syslog) |
| 193 | * @param fmt Format string |
| 194 | * @param errno_value Errno value to include as a string, or 0 |
| 195 | * @param ap Argument list |
| 196 | */ |
| 197 | void elog(int pri, int errno_value, const char *fmt, va_list ap) { |
| 198 | char buffer[1024]; |
| 199 | |
| 200 | if(errno_value == 0) |
| 201 | vlogger(pri, fmt, ap); |
| 202 | else { |
| 203 | memset(buffer, 0, sizeof buffer); |
| 204 | byte_vsnprintf(buffer, sizeof buffer, fmt, ap); |
| 205 | buffer[sizeof buffer - 1] = 0; |
| 206 | logger(pri, "%s: %s", buffer, strerror(errno_value)); |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | /** @brief Log an error and quit |
| 211 | * |
| 212 | * If @c ${DISORDER_FATAL_ABORT} is defined (as anything) then the process |
| 213 | * is aborted, so you can get a backtrace. |
| 214 | */ |
| 215 | void disorder_fatal(int errno_value, const char *msg, ...) { |
| 216 | va_list ap; |
| 217 | |
| 218 | va_start(ap, msg); |
| 219 | elog(LOG_CRIT, errno_value, msg, ap); |
| 220 | va_end(ap); |
| 221 | if(getenv("DISORDER_FATAL_ABORT")) abort(); |
| 222 | exitfn(EXIT_FAILURE); |
| 223 | } |
| 224 | |
| 225 | /** @brief Log an error */ |
| 226 | void disorder_error(int errno_value, const char *msg, ...) { |
| 227 | va_list ap; |
| 228 | |
| 229 | va_start(ap, msg); |
| 230 | elog(LOG_ERR, errno_value, msg, ap); |
| 231 | va_end(ap); |
| 232 | } |
| 233 | |
| 234 | /** @brief Log an informational message */ |
| 235 | void disorder_info(const char *msg, ...) { |
| 236 | va_list ap; |
| 237 | |
| 238 | va_start(ap, msg); |
| 239 | elog(LOG_INFO, 0, msg, ap); |
| 240 | va_end(ap); |
| 241 | } |
| 242 | |
| 243 | /** @brief Log a debug message */ |
| 244 | void disorder_debug(const char *msg, ...) { |
| 245 | va_list ap; |
| 246 | |
| 247 | va_start(ap, msg); |
| 248 | vlogger(LOG_DEBUG, msg, ap); |
| 249 | va_end(ap); |
| 250 | } |
| 251 | |
| 252 | /** @brief Set the program name from @c argc */ |
| 253 | void set_progname(char **argv) { |
| 254 | if((progname = strrchr(argv[0], '/'))) |
| 255 | ++progname; |
| 256 | else |
| 257 | progname = argv[0]; |
| 258 | } |
| 259 | |
| 260 | /* |
| 261 | Local Variables: |
| 262 | c-basic-offset:2 |
| 263 | comment-column:40 |
| 264 | End: |
| 265 | */ |