sysklogd/syslogd.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini syslogd implementation for busybox
   4  *
   5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   6  *
   7  * Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.org>
   8  *
   9  * "circular buffer" Copyright (C) 2001 by Gennady Feldman <gfeldman@gena01.com>
  10  *
  11  * Maintainer: Gennady Feldman <gfeldman@gena01.com> as of Mar 12, 2001
  12  *
  13  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  14  */
  15
  16 /*
  17  * Done in syslogd_and_logger.c:
  18 #include "libbb.h"
  19 #define SYSLOG_NAMES
  20 #define SYSLOG_NAMES_CONST
  21 #include <syslog.h>
  22 */
  23
  24 #include <sys/un.h>
  25 #include <sys/uio.h>
  26
  27 #if ENABLE_FEATURE_REMOTE_LOG
  28 #include <netinet/in.h>
  29 #endif
  30
  31 #if ENABLE_FEATURE_IPC_SYSLOG
  32 #include <sys/ipc.h>
  33 #include <sys/sem.h>
  34 #include <sys/shm.h>
  35 #endif
  36
  37
  38 #define DEBUG 0
  39
  40 /* MARK code is not very useful, is bloat, and broken:
  41  * can deadlock if alarmed to make MARK while writing to IPC buffer
  42  * (semaphores are down but do_mark routine tries to down them again) */
  43 #undef SYSLOGD_MARK
  44
  45 /* Write locking does not seem to be useful either */
  46 #undef SYSLOGD_WRLOCK
  47
  48 enum {
  49         MAX_READ = 256,
  50         DNS_WAIT_SEC = 2 * 60,
  51 };
  52
  53 /* Semaphore operation structures */
  54 struct shbuf_ds {
  55         int32_t size;   /* size of data - 1 */
  56         int32_t tail;   /* end of message list */
  57         char data[1];   /* data/messages */
  58 };
  59
  60 /* Allows us to have smaller initializer. Ugly. */
  61 #define GLOBALS \
  62         const char *logFilePath;                \
  63         int logFD;                              \
  64         /* interval between marks in seconds */ \
  65         /*int markInterval;*/                   \
  66         /* level of messages to be logged */    \
  67         int logLevel;                           \
  68 IF_FEATURE_ROTATE_LOGFILE( \
  69         /* max size of file before rotation */  \
  70         unsigned logFileSize;                   \
  71         /* number of rotated message files */   \
  72         unsigned logFileRotate;                 \
  73         unsigned curFileSize;                   \
  74         smallint isRegular;                     \
  75 ) \
  76 IF_FEATURE_REMOTE_LOG( \
  77         /* udp socket for remote logging */     \
  78         int remoteFD;                           \
  79         len_and_sockaddr* remoteAddr;           \
  80 ) \
  81 IF_FEATURE_IPC_SYSLOG( \
  82         int shmid; /* ipc shared memory id */   \
  83         int s_semid; /* ipc semaphore id */     \
  84         int shm_size;                           \
  85         struct sembuf SMwup[1];                 \
  86         struct sembuf SMwdn[3];                 \
  87 )
  88
  89 struct init_globals {
  90         GLOBALS
  91 };
  92
  93 struct globals {
  94         GLOBALS
  95
  96 #if ENABLE_FEATURE_REMOTE_LOG
  97         unsigned last_dns_resolve;
  98         char *remoteAddrStr;
  99 #endif
 100
 101 #if ENABLE_FEATURE_IPC_SYSLOG
 102         struct shbuf_ds *shbuf;
 103 #endif
 104         time_t last_log_time;
 105         /* localhost's name. We print only first 64 chars */
 106         char *hostname;
 107
 108         /* We recv into recvbuf... */
 109         char recvbuf[MAX_READ * (1 + ENABLE_FEATURE_SYSLOGD_DUP)];
 110         /* ...then copy to parsebuf, escaping control chars */
 111         /* (can grow x2 max) */
 112         char parsebuf[MAX_READ*2];
 113         /* ...then sprintf into printbuf, adding timestamp (15 chars),
 114          * host (64), fac.prio (20) to the message */
 115         /* (growth by: 15 + 64 + 20 + delims = ~110) */
 116         char printbuf[MAX_READ*2 + 128];
 117 };
 118
 119 static const struct init_globals init_data = {
 120         .logFilePath = "/var/log/messages",
 121         .logFD = -1,
 122 #ifdef SYSLOGD_MARK
 123         .markInterval = 20 * 60,
 124 #endif
 125         .logLevel = 8,
 126 #if ENABLE_FEATURE_ROTATE_LOGFILE
 127         .logFileSize = 200 * 1024,
 128         .logFileRotate = 1,
 129 #endif
 130 #if ENABLE_FEATURE_REMOTE_LOG
 131         .remoteFD = -1,
 132 #endif
 133 #if ENABLE_FEATURE_IPC_SYSLOG
 134         .shmid = -1,
 135         .s_semid = -1,
 136         .shm_size = ((CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE)*1024), // default shm size
 137         .SMwup = { {1, -1, IPC_NOWAIT} },
 138         .SMwdn = { {0, 0}, {1, 0}, {1, +1} },
 139 #endif
 140 };
 141
 142 #define G (*ptr_to_globals)
 143 #define INIT_G() do { \
 144         SET_PTR_TO_GLOBALS(memcpy(xzalloc(sizeof(G)), &init_data, sizeof(init_data))); \
 145 } while (0)
 146
 147
 148 /* Options */
 149 enum {
 150         OPTBIT_mark = 0, // -m
 151         OPTBIT_nofork, // -n
 152         OPTBIT_outfile, // -O
 153         OPTBIT_loglevel, // -l
 154         OPTBIT_small, // -S
 155         IF_FEATURE_ROTATE_LOGFILE(OPTBIT_filesize   ,)  // -s
 156         IF_FEATURE_ROTATE_LOGFILE(OPTBIT_rotatecnt  ,)  // -b
 157         IF_FEATURE_REMOTE_LOG(    OPTBIT_remotelog  ,)  // -R
 158         IF_FEATURE_REMOTE_LOG(    OPTBIT_locallog   ,)  // -L
 159         IF_FEATURE_IPC_SYSLOG(    OPTBIT_circularlog,)  // -C
 160         IF_FEATURE_SYSLOGD_DUP(   OPTBIT_dup        ,)  // -D
 161
 162         OPT_mark        = 1 << OPTBIT_mark    ,
 163         OPT_nofork      = 1 << OPTBIT_nofork  ,
 164         OPT_outfile     = 1 << OPTBIT_outfile ,
 165         OPT_loglevel    = 1 << OPTBIT_loglevel,
 166         OPT_small       = 1 << OPTBIT_small   ,
 167         OPT_filesize    = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_filesize   )) + 0,
 168         OPT_rotatecnt   = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_rotatecnt  )) + 0,
 169         OPT_remotelog   = IF_FEATURE_REMOTE_LOG(    (1 << OPTBIT_remotelog  )) + 0,
 170         OPT_locallog    = IF_FEATURE_REMOTE_LOG(    (1 << OPTBIT_locallog   )) + 0,
 171         OPT_circularlog = IF_FEATURE_IPC_SYSLOG(    (1 << OPTBIT_circularlog)) + 0,
 172         OPT_dup         = IF_FEATURE_SYSLOGD_DUP(   (1 << OPTBIT_dup        )) + 0,
 173 };
 174 #define OPTION_STR "m:nO:l:S" \
 175         IF_FEATURE_ROTATE_LOGFILE("s:" ) \
 176         IF_FEATURE_ROTATE_LOGFILE("b:" ) \
 177         IF_FEATURE_REMOTE_LOG(    "R:" ) \
 178         IF_FEATURE_REMOTE_LOG(    "L"  ) \
 179         IF_FEATURE_IPC_SYSLOG(    "C::") \
 180         IF_FEATURE_SYSLOGD_DUP(   "D"  )
 181 #define OPTION_DECL *opt_m, *opt_l \
 182         IF_FEATURE_ROTATE_LOGFILE(,*opt_s) \
 183         IF_FEATURE_ROTATE_LOGFILE(,*opt_b) \
 184         IF_FEATURE_IPC_SYSLOG(    ,*opt_C = NULL)
 185 #define OPTION_PARAM &opt_m, &G.logFilePath, &opt_l \
 186         IF_FEATURE_ROTATE_LOGFILE(,&opt_s) \
 187         IF_FEATURE_ROTATE_LOGFILE(,&opt_b) \
 188         IF_FEATURE_REMOTE_LOG(    ,&G.remoteAddrStr) \
 189         IF_FEATURE_IPC_SYSLOG(    ,&opt_C)
 190
 191
 192 /* circular buffer variables/structures */
 193 #if ENABLE_FEATURE_IPC_SYSLOG
 194
 195 #if CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE < 4
 196 #error Sorry, you must set the syslogd buffer size to at least 4KB.
 197 #error Please check CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE
 198 #endif
 199
 200 /* our shared key (syslogd.c and logread.c must be in sync) */
 201 enum { KEY_ID = 0x414e4547 }; /* "GENA" */
 202
 203 static void ipcsyslog_cleanup(void)
 204 {
 205         if (G.shmid != -1) {
 206                 shmdt(G.shbuf);
 207         }
 208         if (G.shmid != -1) {
 209                 shmctl(G.shmid, IPC_RMID, NULL);
 210         }
 211         if (G.s_semid != -1) {
 212                 semctl(G.s_semid, 0, IPC_RMID, 0);
 213         }
 214 }
 215
 216 static void ipcsyslog_init(void)
 217 {
 218         if (DEBUG)
 219                 printf("shmget(%x, %d,...)\n", (int)KEY_ID, G.shm_size);
 220
 221         G.shmid = shmget(KEY_ID, G.shm_size, IPC_CREAT | 0644);
 222         if (G.shmid == -1) {
 223                 bb_perror_msg_and_die("shmget");
 224         }
 225
 226         G.shbuf = shmat(G.shmid, NULL, 0);
 227         if (G.shbuf == (void*) -1L) { /* shmat has bizarre error return */
 228                 bb_perror_msg_and_die("shmat");
 229         }
 230
 231         memset(G.shbuf, 0, G.shm_size);
 232         G.shbuf->size = G.shm_size - offsetof(struct shbuf_ds, data) - 1;
 233         /*G.shbuf->tail = 0;*/
 234
 235         // we'll trust the OS to set initial semval to 0 (let's hope)
 236         G.s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023);
 237         if (G.s_semid == -1) {
 238                 if (errno == EEXIST) {
 239                         G.s_semid = semget(KEY_ID, 2, 0);
 240                         if (G.s_semid != -1)
 241                                 return;
 242                 }
 243                 bb_perror_msg_and_die("semget");
 244         }
 245 }
 246
 247 /* Write message to shared mem buffer */
 248 static void log_to_shmem(const char *msg, int len)
 249 {
 250         int old_tail, new_tail;
 251
 252         if (semop(G.s_semid, G.SMwdn, 3) == -1) {
 253                 bb_perror_msg_and_die("SMwdn");
 254         }
 255
 256         /* Circular Buffer Algorithm:
 257          * --------------------------
 258          * tail == position where to store next syslog message.
 259          * tail's max value is (shbuf->size - 1)
 260          * Last byte of buffer is never used and remains NUL.
 261          */
 262         len++; /* length with NUL included */
 263  again:
 264         old_tail = G.shbuf->tail;
 265         new_tail = old_tail + len;
 266         if (new_tail < G.shbuf->size) {
 267                 /* store message, set new tail */
 268                 memcpy(G.shbuf->data + old_tail, msg, len);
 269                 G.shbuf->tail = new_tail;
 270         } else {
 271                 /* k == available buffer space ahead of old tail */
 272                 int k = G.shbuf->size - old_tail;
 273                 /* copy what fits to the end of buffer, and repeat */
 274                 memcpy(G.shbuf->data + old_tail, msg, k);
 275                 msg += k;
 276                 len -= k;
 277                 G.shbuf->tail = 0;
 278                 goto again;
 279         }
 280         if (semop(G.s_semid, G.SMwup, 1) == -1) {
 281                 bb_perror_msg_and_die("SMwup");
 282         }
 283         if (DEBUG)
 284                 printf("tail:%d\n", G.shbuf->tail);
 285 }
 286 #else
 287 void ipcsyslog_cleanup(void);
 288 void ipcsyslog_init(void);
 289 void log_to_shmem(const char *msg);
 290 #endif /* FEATURE_IPC_SYSLOG */
 291
 292
 293 /* Print a message to the log file. */
 294 static void log_locally(time_t now, char *msg)
 295 {
 296 #ifdef SYSLOGD_WRLOCK
 297         struct flock fl;
 298 #endif
 299         int len = strlen(msg);
 300
 301 #if ENABLE_FEATURE_IPC_SYSLOG
 302         if ((option_mask32 & OPT_circularlog) && G.shbuf) {
 303                 log_to_shmem(msg, len);
 304                 return;
 305         }
 306 #endif
 307         if (G.logFD >= 0) {
 308                 /* Reopen log file every second. This allows admin
 309                  * to delete the file and not worry about restarting us.
 310                  * This costs almost nothing since it happens
 311                  * _at most_ once a second.
 312                  */
 313                 if (!now)
 314                         now = time(NULL);
 315                 if (G.last_log_time != now) {
 316                         G.last_log_time = now;
 317                         close(G.logFD);
 318                         goto reopen;
 319                 }
 320         } else {
 321  reopen:
 322                 G.logFD = open(G.logFilePath, O_WRONLY | O_CREAT
 323                                         | O_NOCTTY | O_APPEND | O_NONBLOCK,
 324                                         0666);
 325                 if (G.logFD < 0) {
 326                         /* cannot open logfile? - print to /dev/console then */
 327                         int fd = device_open(DEV_CONSOLE, O_WRONLY | O_NOCTTY | O_NONBLOCK);
 328                         if (fd < 0)
 329                                 fd = 2; /* then stderr, dammit */
 330                         full_write(fd, msg, len);
 331                         if (fd != 2)
 332                                 close(fd);
 333                         return;
 334                 }
 335 #if ENABLE_FEATURE_ROTATE_LOGFILE
 336                 {
 337                         struct stat statf;
 338                         G.isRegular = (fstat(G.logFD, &statf) == 0 && S_ISREG(statf.st_mode));
 339                         /* bug (mostly harmless): can wrap around if file > 4gb */
 340                         G.curFileSize = statf.st_size;
 341                 }
 342 #endif
 343         }
 344
 345 #ifdef SYSLOGD_WRLOCK
 346         fl.l_whence = SEEK_SET;
 347         fl.l_start = 0;
 348         fl.l_len = 1;
 349         fl.l_type = F_WRLCK;
 350         fcntl(G.logFD, F_SETLKW, &fl);
 351 #endif
 352
 353 #if ENABLE_FEATURE_ROTATE_LOGFILE
 354         if (G.logFileSize && G.isRegular && G.curFileSize > G.logFileSize) {
 355                 if (G.logFileRotate) { /* always 0..99 */
 356                         int i = strlen(G.logFilePath) + 3 + 1;
 357                         char oldFile[i];
 358                         char newFile[i];
 359                         i = G.logFileRotate - 1;
 360                         /* rename: f.8 -> f.9; f.7 -> f.8; ... */
 361                         while (1) {
 362                                 sprintf(newFile, "%s.%d", G.logFilePath, i);
 363                                 if (i == 0) break;
 364                                 sprintf(oldFile, "%s.%d", G.logFilePath, --i);
 365                                 /* ignore errors - file might be missing */
 366                                 rename(oldFile, newFile);
 367                         }
 368                         /* newFile == "f.0" now */
 369                         rename(G.logFilePath, newFile);
 370 #ifdef SYSLOGD_WRLOCK
 371                         fl.l_type = F_UNLCK;
 372                         fcntl(G.logFD, F_SETLKW, &fl);
 373 #endif
 374                         close(G.logFD);
 375                         goto reopen;
 376                 }
 377                 ftruncate(G.logFD, 0);
 378         }
 379         G.curFileSize +=
 380 #endif
 381                         full_write(G.logFD, msg, len);
 382 #ifdef SYSLOGD_WRLOCK
 383         fl.l_type = F_UNLCK;
 384         fcntl(G.logFD, F_SETLKW, &fl);
 385 #endif
 386 }
 387
 388 static void parse_fac_prio_20(int pri, char *res20)
 389 {
 390         const CODE *c_pri, *c_fac;
 391
 392         if (pri != 0) {
 393                 c_fac = facilitynames;
 394                 while (c_fac->c_name) {
 395                         if (c_fac->c_val != (LOG_FAC(pri) << 3)) {
 396                                 c_fac++;
 397                                 continue;
 398                         }
 399                         /* facility is found, look for prio */
 400                         c_pri = prioritynames;
 401                         while (c_pri->c_name) {
 402                                 if (c_pri->c_val != LOG_PRI(pri)) {
 403                                         c_pri++;
 404                                         continue;
 405                                 }
 406                                 snprintf(res20, 20, "%s.%s",
 407                                                 c_fac->c_name, c_pri->c_name);
 408                                 return;
 409                         }
 410                         /* prio not found, bail out */
 411                         break;
 412                 }
 413                 snprintf(res20, 20, "<%d>", pri);
 414         }
 415 }
 416
 417 /* len parameter is used only for "is there a timestamp?" check.
 418  * NB: some callers cheat and supply len==0 when they know
 419  * that there is no timestamp, short-circuiting the test. */
 420 static void timestamp_and_log(int pri, char *msg, int len)
 421 {
 422         char *timestamp;
 423         time_t now;
 424
 425         /* Jan 18 00:11:22 msg... */
 426         /* 01234567890123456 */
 427         if (len < 16 || msg[3] != ' ' || msg[6] != ' '
 428          || msg[9] != ':' || msg[12] != ':' || msg[15] != ' '
 429         ) {
 430                 time(&now);
 431                 timestamp = ctime(&now) + 4; /* skip day of week */
 432         } else {
 433                 now = 0;
 434                 timestamp = msg;
 435                 msg += 16;
 436         }
 437         timestamp[15] = '\0';
 438
 439         if (option_mask32 & OPT_small)
 440                 sprintf(G.printbuf, "%s %s\n", timestamp, msg);
 441         else {
 442                 char res[20];
 443                 parse_fac_prio_20(pri, res);
 444                 sprintf(G.printbuf, "%s %.64s %s %s\n", timestamp, G.hostname, res, msg);
 445         }
 446
 447         /* Log message locally (to file or shared mem) */
 448         log_locally(now, G.printbuf);
 449 }
 450
 451 static void timestamp_and_log_internal(const char *msg)
 452 {
 453         /* -L, or no -R */
 454         if (ENABLE_FEATURE_REMOTE_LOG && !(option_mask32 & OPT_locallog))
 455                 return;
 456         timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)msg, 0);
 457 }
 458
 459 /* tmpbuf[len] is a NUL byte (set by caller), but there can be other,
 460  * embedded NULs. Split messages on each of these NULs, parse prio,
 461  * escape control chars and log each locally. */
 462 static void split_escape_and_log(char *tmpbuf, int len)
 463 {
 464         char *p = tmpbuf;
 465
 466         tmpbuf += len;
 467         while (p < tmpbuf) {
 468                 char c;
 469                 char *q = G.parsebuf;
 470                 int pri = (LOG_USER | LOG_NOTICE);
 471
 472                 if (*p == '<') {
 473                         /* Parse the magic priority number */
 474                         pri = bb_strtou(p + 1, &p, 10);
 475                         if (*p == '>')
 476                                 p++;
 477                         if (pri & ~(LOG_FACMASK | LOG_PRIMASK))
 478                                 pri = (LOG_USER | LOG_NOTICE);
 479                 }
 480
 481                 while ((c = *p++)) {
 482                         if (c == '\n')
 483                                 c = ' ';
 484                         if (!(c & ~0x1f) && c != '\t') {
 485                                 *q++ = '^';
 486                                 c += '@'; /* ^@, ^A, ^B... */
 487                         }
 488                         *q++ = c;
 489                 }
 490                 *q = '\0';
 491
 492                 /* Now log it */
 493                 if (LOG_PRI(pri) < G.logLevel)
 494                         timestamp_and_log(pri, G.parsebuf, q - G.parsebuf);
 495         }
 496 }
 497
 498 #ifdef SYSLOGD_MARK
 499 static void do_mark(int sig)
 500 {
 501         if (G.markInterval) {
 502                 timestamp_and_log_internal("-- MARK --");
 503                 alarm(G.markInterval);
 504         }
 505 }
 506 #endif
 507
 508 /* Don't inline: prevent struct sockaddr_un to take up space on stack
 509  * permanently */
 510 static NOINLINE int create_socket(void)
 511 {
 512         struct sockaddr_un sunx;
 513         int sock_fd;
 514         char *dev_log_name;
 515
 516         memset(&sunx, 0, sizeof(sunx));
 517         sunx.sun_family = AF_UNIX;
 518
 519         /* Unlink old /dev/log or object it points to. */
 520         /* (if it exists, bind will fail) */
 521         strcpy(sunx.sun_path, "/dev/log");
 522         dev_log_name = xmalloc_follow_symlinks("/dev/log");
 523         if (dev_log_name) {
 524                 safe_strncpy(sunx.sun_path, dev_log_name, sizeof(sunx.sun_path));
 525                 free(dev_log_name);
 526         }
 527         unlink(sunx.sun_path);
 528
 529         sock_fd = xsocket(AF_UNIX, SOCK_DGRAM, 0);
 530         xbind(sock_fd, (struct sockaddr *) &sunx, sizeof(sunx));
 531         chmod("/dev/log", 0666);
 532
 533         return sock_fd;
 534 }
 535
 536 #if ENABLE_FEATURE_REMOTE_LOG
 537 static int try_to_resolve_remote(void)
 538 {
 539         if (!G.remoteAddr) {
 540                 unsigned now = monotonic_sec();
 541
 542                 /* Don't resolve name too often - DNS timeouts can be big */
 543                 if ((now - G.last_dns_resolve) < DNS_WAIT_SEC)
 544                         return -1;
 545                 G.last_dns_resolve = now;
 546                 G.remoteAddr = host2sockaddr(G.remoteAddrStr, 514);
 547                 if (!G.remoteAddr)
 548                         return -1;
 549         }
 550         return socket(G.remoteAddr->u.sa.sa_family, SOCK_DGRAM, 0);
 551 }
 552 #endif
 553
 554 static void do_syslogd(void) NORETURN;
 555 static void do_syslogd(void)
 556 {
 557         int sock_fd;
 558 #if ENABLE_FEATURE_SYSLOGD_DUP
 559         int last_sz = -1;
 560         char *last_buf;
 561         char *recvbuf = G.recvbuf;
 562 #else
 563 #define recvbuf (G.recvbuf)
 564 #endif
 565
 566         /* Set up signal handlers (so that they interrupt read()) */
 567         signal_no_SA_RESTART_empty_mask(SIGTERM, record_signo);
 568         signal_no_SA_RESTART_empty_mask(SIGINT, record_signo);
 569         //signal_no_SA_RESTART_empty_mask(SIGQUIT, record_signo);
 570         signal(SIGHUP, SIG_IGN);
 571 #ifdef SYSLOGD_MARK
 572         signal(SIGALRM, do_mark);
 573         alarm(G.markInterval);
 574 #endif
 575         sock_fd = create_socket();
 576
 577         if (ENABLE_FEATURE_IPC_SYSLOG && (option_mask32 & OPT_circularlog)) {
 578                 ipcsyslog_init();
 579         }
 580
 581         timestamp_and_log_internal("syslogd started: BusyBox v" BB_VER);
 582
 583         while (!bb_got_signal) {
 584                 ssize_t sz;
 585
 586 #if ENABLE_FEATURE_SYSLOGD_DUP
 587                 last_buf = recvbuf;
 588                 if (recvbuf == G.recvbuf)
 589                         recvbuf = G.recvbuf + MAX_READ;
 590                 else
 591                         recvbuf = G.recvbuf;
 592 #endif
 593  read_again:
 594                 sz = read(sock_fd, recvbuf, MAX_READ - 1);
 595                 if (sz < 0) {
 596                         if (!bb_got_signal)
 597                                 bb_perror_msg("read from /dev/log");
 598                         break;
 599                 }
 600
 601                 /* Drop trailing '\n' and NULs (typically there is one NUL) */
 602                 while (1) {
 603                         if (sz == 0)
 604                                 goto read_again;
 605                         /* man 3 syslog says: "A trailing newline is added when needed".
 606                          * However, neither glibc nor uclibc do this:
 607                          * syslog(prio, "test")   sends "test\0" to /dev/log,
 608                          * syslog(prio, "test\n") sends "test\n\0".
 609                          * IOW: newline is passed verbatim!
 610                          * I take it to mean that it's syslogd's job
 611                          * to make those look identical in the log files. */
 612                         if (recvbuf[sz-1] != '\0' && recvbuf[sz-1] != '\n')
 613                                 break;
 614                         sz--;
 615                 }
 616 #if ENABLE_FEATURE_SYSLOGD_DUP
 617                 if ((option_mask32 & OPT_dup) && (sz == last_sz))
 618                         if (memcmp(last_buf, recvbuf, sz) == 0)
 619                                 continue;
 620                 last_sz = sz;
 621 #endif
 622 #if ENABLE_FEATURE_REMOTE_LOG
 623                 /* We are not modifying log messages in any way before send */
 624                 /* Remote site cannot trust _us_ anyway and need to do validation again */
 625                 if (G.remoteAddrStr) {
 626                         if (-1 == G.remoteFD) {
 627                                 G.remoteFD = try_to_resolve_remote();
 628                                 if (-1 == G.remoteFD)
 629                                         goto no_luck;
 630                         }
 631                         /* Stock syslogd sends it '\n'-terminated
 632                          * over network, mimic that */
 633                         recvbuf[sz] = '\n';
 634                         /* send message to remote logger, ignore possible error */
 635                         /* TODO: on some errors, close and set G.remoteFD to -1
 636                          * so that DNS resolution and connect is retried? */
 637                         sendto(G.remoteFD, recvbuf, sz+1, MSG_DONTWAIT,
 638                                     &G.remoteAddr->u.sa, G.remoteAddr->len);
 639  no_luck: ;
 640                 }
 641 #endif
 642                 if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) {
 643                         recvbuf[sz] = '\0'; /* ensure it *is* NUL terminated */
 644                         split_escape_and_log(recvbuf, sz);
 645                 }
 646         } /* while (!bb_got_signal) */
 647
 648         timestamp_and_log_internal("syslogd exiting");
 649         puts("syslogd exiting");
 650         if (ENABLE_FEATURE_IPC_SYSLOG)
 651                 ipcsyslog_cleanup();
 652         kill_myself_with_sig(bb_got_signal);
 653 #undef recvbuf
 654 }
 655
 656 int syslogd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 657 int syslogd_main(int argc UNUSED_PARAM, char **argv)
 658 {
 659         char OPTION_DECL;
 660         int opts;
 661
 662         INIT_G();
 663 #if ENABLE_FEATURE_REMOTE_LOG
 664         G.last_dns_resolve = monotonic_sec() - DNS_WAIT_SEC - 1;
 665 #endif
 666
 667         /* do normal option parsing */
 668         opt_complementary = "=0"; /* no non-option params */
 669         opts = getopt32(argv, OPTION_STR, OPTION_PARAM);
 670 #ifdef SYSLOGD_MARK
 671         if (opts & OPT_mark) // -m
 672                 G.markInterval = xatou_range(opt_m, 0, INT_MAX/60) * 60;
 673 #endif
 674         //if (opts & OPT_nofork) // -n
 675         //if (opts & OPT_outfile) // -O
 676         if (opts & OPT_loglevel) // -l
 677                 G.logLevel = xatou_range(opt_l, 1, 8);
 678         //if (opts & OPT_small) // -S
 679 #if ENABLE_FEATURE_ROTATE_LOGFILE
 680         if (opts & OPT_filesize) // -s
 681                 G.logFileSize = xatou_range(opt_s, 0, INT_MAX/1024) * 1024;
 682         if (opts & OPT_rotatecnt) // -b
 683                 G.logFileRotate = xatou_range(opt_b, 0, 99);
 684 #endif
 685 #if ENABLE_FEATURE_IPC_SYSLOG
 686         if (opt_C) // -Cn
 687                 G.shm_size = xatoul_range(opt_C, 4, INT_MAX/1024) * 1024;
 688 #endif
 689
 690         /* If they have not specified remote logging, then log locally */
 691         if (ENABLE_FEATURE_REMOTE_LOG && !(opts & OPT_remotelog)) // -R
 692                 option_mask32 |= OPT_locallog;
 693
 694         /* Store away localhost's name before the fork */
 695         G.hostname = safe_gethostname();
 696         *strchrnul(G.hostname, '.') = '\0';
 697
 698         if (!(opts & OPT_nofork)) {
 699                 bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
 700         }
 701         //umask(0); - why??
 702         write_pidfile("/var/run/syslogd.pid");
 703         do_syslogd();
 704         /* return EXIT_SUCCESS; */
 705 }
 706
 707 /* Clean up. Needed because we are included from syslogd_and_logger.c */
 708 #undef DEBUG
 709 #undef SYSLOGD_MARK
 710 #undef SYSLOGD_WRLOCK
 711 #undef G
 712 #undef GLOBALS
 713 #undef INIT_G
 714 #undef OPTION_STR
 715 #undef OPTION_DECL
 716 #undef OPTION_PARAM