1 /* SPDX-License-Identifier: BSD-2-Clause */ 2 /* 3 * logerr: errx with logging 4 * Copyright (c) 2006-2020 Roy Marples <roy@marples.name> 5 * All rights reserved 6 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/time.h> 30 #include <errno.h> 31 #include <stdbool.h> 32 #include <stdarg.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <string.h> 36 #include <syslog.h> 37 #include <time.h> 38 #include <unistd.h> 39 40 #include "logerr.h" 41 42 #ifndef LOGERR_SYSLOG_FACILITY 43 #define LOGERR_SYSLOG_FACILITY LOG_DAEMON 44 #endif 45 46 #ifdef SMALL 47 #undef LOGERR_TAG 48 #endif 49 50 #define UNUSED(a) (void)(a) 51 52 struct logctx { 53 char log_buf[BUFSIZ]; 54 unsigned int log_opts; 55 FILE *log_err; 56 #ifndef SMALL 57 FILE *log_file; 58 #ifdef LOGERR_TAG 59 const char *log_tag; 60 #endif 61 #endif 62 }; 63 64 static struct logctx _logctx = { 65 /* syslog style, but without the hostname or tag. */ 66 .log_opts = LOGERR_LOG | LOGERR_LOG_DATE | LOGERR_LOG_PID, 67 }; 68 69 #if defined(LOGERR_TAG) && defined(__linux__) 70 /* Poor man's getprogname(3). */ 71 static char *_logprog; 72 static const char * 73 getprogname(void) 74 { 75 const char *p; 76 77 /* Use PATH_MAX + 1 to avoid truncation. */ 78 if (_logprog == NULL) { 79 /* readlink(2) does not append a NULL byte, 80 * so zero the buffer. */ 81 if ((_logprog = calloc(1, PATH_MAX + 1)) == NULL) 82 return NULL; 83 } 84 if (readlink("/proc/self/exe", _logprog, PATH_MAX + 1) == -1) 85 return NULL; 86 if (_logprog[0] == '[') 87 return NULL; 88 p = strrchr(_logprog, '/'); 89 if (p == NULL) 90 return _logprog; 91 return p + 1; 92 } 93 #endif 94 95 #ifndef SMALL 96 /* Write the time, syslog style. month day time - */ 97 static int 98 logprintdate(FILE *stream) 99 { 100 struct timeval tv; 101 time_t now; 102 struct tm tmnow; 103 char buf[32]; 104 105 if (gettimeofday(&tv, NULL) == -1) 106 return -1; 107 108 now = tv.tv_sec; 109 if (localtime_r(&now, &tmnow) == NULL) 110 return -1; 111 if (strftime(buf, sizeof(buf), "%b %d %T ", &tmnow) == 0) 112 return -1; 113 return fprintf(stream, "%s", buf); 114 } 115 #endif 116 117 __printflike(3, 0) static int 118 vlogprintf_r(struct logctx *ctx, FILE *stream, const char *fmt, va_list args) 119 { 120 int len = 0, e; 121 va_list a; 122 #ifndef SMALL 123 FILE *err = ctx->log_err == NULL ? stderr : ctx->log_err; 124 bool log_pid; 125 #ifdef LOGERR_TAG 126 bool log_tag; 127 #endif 128 129 if ((stream == err && ctx->log_opts & LOGERR_ERR_DATE) || 130 (stream != err && ctx->log_opts & LOGERR_LOG_DATE)) 131 { 132 if ((e = logprintdate(stream)) == -1) 133 return -1; 134 len += e; 135 } 136 137 #ifdef LOGERR_TAG 138 log_tag = ((stream == err && ctx->log_opts & LOGERR_ERR_TAG) || 139 (stream != err && ctx->log_opts & LOGERR_LOG_TAG)); 140 if (log_tag) { 141 if (ctx->log_tag == NULL) 142 ctx->log_tag = getprogname(); 143 if ((e = fprintf(stream, "%s", ctx->log_tag)) == -1) 144 return -1; 145 len += e; 146 } 147 #endif 148 149 log_pid = ((stream == err && ctx->log_opts & LOGERR_ERR_PID) || 150 (stream != err && ctx->log_opts & LOGERR_LOG_PID)); 151 if (log_pid) { 152 if ((e = fprintf(stream, "[%d]", getpid())) == -1) 153 return -1; 154 len += e; 155 } 156 157 #ifdef LOGERR_TAG 158 if (log_tag || log_pid) 159 #else 160 if (log_pid) 161 #endif 162 { 163 if ((e = fprintf(stream, ": ")) == -1) 164 return -1; 165 len += e; 166 } 167 #else 168 UNUSED(ctx); 169 #endif 170 171 va_copy(a, args); 172 e = vfprintf(stream, fmt, a); 173 if (fputc('\n', stream) == EOF) 174 e = -1; 175 else if (e != -1) 176 e++; 177 va_end(a); 178 179 return e == -1 ? -1 : len + e; 180 } 181 182 /* 183 * NetBSD's gcc has been modified to check for the non standard %m in printf 184 * like functions and warn noisily about it that they should be marked as 185 * syslog like instead. 186 * This is all well and good, but our logger also goes via vfprintf and 187 * when marked as a sysloglike funcion, gcc will then warn us that the 188 * function should be printflike instead! 189 * This creates an infinte loop of gcc warnings. 190 * Until NetBSD solves this issue, we have to disable a gcc diagnostic 191 * for our fully standards compliant code in the logger function. 192 */ 193 #if defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ > 5)) 194 #pragma GCC diagnostic push 195 #pragma GCC diagnostic ignored "-Wmissing-format-attribute" 196 #endif 197 __printflike(2, 0) static int 198 vlogmessage(int pri, const char *fmt, va_list args) 199 { 200 struct logctx *ctx = &_logctx; 201 int len = 0; 202 203 if (ctx->log_opts & LOGERR_ERR && 204 (pri <= LOG_ERR || 205 (!(ctx->log_opts & LOGERR_QUIET) && pri <= LOG_INFO) || 206 (ctx->log_opts & LOGERR_DEBUG && pri <= LOG_DEBUG))) 207 { 208 FILE *err; 209 210 err = ctx->log_err == NULL ? stderr : ctx->log_err; 211 len = vlogprintf_r(ctx, err, fmt, args); 212 } 213 214 if (!(ctx->log_opts & LOGERR_LOG)) 215 return len; 216 217 #ifndef SMALL 218 if (ctx->log_file != NULL && 219 (pri != LOG_DEBUG || (ctx->log_opts & LOGERR_DEBUG))) 220 len = vlogprintf_r(ctx, ctx->log_file, fmt, args); 221 #endif 222 223 vsyslog(pri, fmt, args); 224 return len; 225 } 226 #if defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ > 5)) 227 #pragma GCC diagnostic pop 228 #endif 229 230 __printflike(2, 3) void 231 logmessage(int pri, const char *fmt, ...) 232 { 233 va_list args; 234 235 va_start(args, fmt); 236 vlogmessage(pri, fmt, args); 237 va_end(args); 238 } 239 240 __printflike(2, 0) static void 241 vlogerrmessage(int pri, const char *fmt, va_list args) 242 { 243 int _errno = errno; 244 char buf[1024]; 245 246 vsnprintf(buf, sizeof(buf), fmt, args); 247 logmessage(pri, "%s: %s", buf, strerror(_errno)); 248 errno = _errno; 249 } 250 251 __printflike(2, 3) void 252 logerrmessage(int pri, const char *fmt, ...) 253 { 254 va_list args; 255 256 va_start(args, fmt); 257 vlogerrmessage(pri, fmt, args); 258 va_end(args); 259 } 260 261 void 262 log_debug(const char *fmt, ...) 263 { 264 va_list args; 265 266 va_start(args, fmt); 267 vlogerrmessage(LOG_DEBUG, fmt, args); 268 va_end(args); 269 } 270 271 void 272 log_debugx(const char *fmt, ...) 273 { 274 va_list args; 275 276 va_start(args, fmt); 277 vlogmessage(LOG_DEBUG, fmt, args); 278 va_end(args); 279 } 280 281 void 282 log_info(const char *fmt, ...) 283 { 284 va_list args; 285 286 va_start(args, fmt); 287 vlogerrmessage(LOG_INFO, fmt, args); 288 va_end(args); 289 } 290 291 void 292 log_infox(const char *fmt, ...) 293 { 294 va_list args; 295 296 va_start(args, fmt); 297 vlogmessage(LOG_INFO, fmt, args); 298 va_end(args); 299 } 300 301 void 302 log_warn(const char *fmt, ...) 303 { 304 va_list args; 305 306 va_start(args, fmt); 307 vlogerrmessage(LOG_WARNING, fmt, args); 308 va_end(args); 309 } 310 311 void 312 log_warnx(const char *fmt, ...) 313 { 314 va_list args; 315 316 va_start(args, fmt); 317 vlogmessage(LOG_WARNING, fmt, args); 318 va_end(args); 319 } 320 321 void 322 log_err(const char *fmt, ...) 323 { 324 va_list args; 325 326 va_start(args, fmt); 327 vlogerrmessage(LOG_ERR, fmt, args); 328 va_end(args); 329 } 330 331 void 332 log_errx(const char *fmt, ...) 333 { 334 va_list args; 335 336 va_start(args, fmt); 337 vlogmessage(LOG_ERR, fmt, args); 338 va_end(args); 339 } 340 341 unsigned int 342 loggetopts(void) 343 { 344 struct logctx *ctx = &_logctx; 345 346 return ctx->log_opts; 347 } 348 349 void 350 logsetopts(unsigned int opts) 351 { 352 struct logctx *ctx = &_logctx; 353 354 ctx->log_opts = opts; 355 setlogmask(LOG_UPTO(opts & LOGERR_DEBUG ? LOG_DEBUG : LOG_INFO)); 356 } 357 358 #ifdef LOGERR_TAG 359 void 360 logsettag(const char *tag) 361 { 362 #if !defined(SMALL) 363 struct logctx *ctx = &_logctx; 364 365 ctx->log_tag = tag; 366 #else 367 UNUSED(tag); 368 #endif 369 } 370 #endif 371 372 int 373 loggeterrfd(void) 374 { 375 struct logctx *ctx = &_logctx; 376 FILE *err = ctx->log_err == NULL ? stderr : ctx->log_err; 377 378 return fileno(err); 379 } 380 381 int 382 logseterrfd(int fd) 383 { 384 struct logctx *ctx = &_logctx; 385 386 if (ctx->log_err != NULL) 387 fclose(ctx->log_err); 388 if (fd == -1) { 389 ctx->log_err = NULL; 390 return 0; 391 } 392 ctx->log_err = fdopen(fd, "a"); 393 return ctx->log_err == NULL ? -1 : 0; 394 } 395 396 int 397 logopen(const char *path) 398 { 399 struct logctx *ctx = &_logctx; 400 401 /* Cache timezone */ 402 tzset(); 403 404 (void)setvbuf(stderr, ctx->log_buf, _IOLBF, sizeof(ctx->log_buf)); 405 406 if (path == NULL) { 407 int opts = 0; 408 409 if (ctx->log_opts & LOGERR_LOG_PID) 410 opts |= LOG_PID; 411 openlog(NULL, opts, LOGERR_SYSLOG_FACILITY); 412 return 1; 413 } 414 415 #ifndef SMALL 416 if ((ctx->log_file = fopen(path, "a")) == NULL) 417 return -1; 418 setlinebuf(ctx->log_file); 419 return fileno(ctx->log_file); 420 #else 421 errno = ENOTSUP; 422 return -1; 423 #endif 424 } 425 426 void 427 logclose(void) 428 { 429 #ifndef SMALL 430 struct logctx *ctx = &_logctx; 431 #endif 432 433 closelog(); 434 #ifndef SMALL 435 if (ctx->log_file == NULL) 436 return; 437 fclose(ctx->log_file); 438 ctx->log_file = NULL; 439 #endif 440 #if defined(LOGERR_TAG) && defined(__linux__) 441 free(_logprog); 442 #endif 443 } 444