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