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 #if ENABLE_FEATURE_REMOTE_LOG
  61 typedef struct {
  62         int remoteFD;
  63         unsigned last_dns_resolve;
  64         len_and_sockaddr *remoteAddr;
  65         const char *remoteHostname;
  66 } remoteHost_t;
  67 #endif
  68
  69 /* Allows us to have smaller initializer. Ugly. */
  70 #define GLOBALS \
  71         const char *logFilePath;                \
  72         int logFD;                              \
  73         /* interval between marks in seconds */ \
  74         /*int markInterval;*/                   \
  75         /* level of messages to be logged */    \
  76         int logLevel;                           \
  77 IF_FEATURE_ROTATE_LOGFILE( \
  78         /* max size of file before rotation */  \
  79         unsigned logFileSize;                   \
  80         /* number of rotated message files */   \
  81         unsigned logFileRotate;                 \
  82         unsigned curFileSize;                   \
  83         smallint isRegular;                     \
  84 ) \
  85 IF_FEATURE_IPC_SYSLOG( \
  86         int shmid; /* ipc shared memory id */   \
  87         int s_semid; /* ipc semaphore id */     \
  88         int shm_size;                           \
  89         struct sembuf SMwup[1];                 \
  90         struct sembuf SMwdn[3];                 \
  91 )
  92
  93 struct init_globals {
  94         GLOBALS
  95 };
  96
  97 struct globals {
  98         GLOBALS
  99
 100 #if ENABLE_FEATURE_REMOTE_LOG
 101         llist_t *remoteHosts;
 102 #endif
 103 #if ENABLE_FEATURE_IPC_SYSLOG
 104         struct shbuf_ds *shbuf;
 105 #endif
 106         time_t last_log_time;
 107         /* localhost's name. We print only first 64 chars */
 108         char *hostname;
 109
 110         /* We recv into recvbuf... */
 111         char recvbuf[MAX_READ * (1 + ENABLE_FEATURE_SYSLOGD_DUP)];
 112         /* ...then copy to parsebuf, escaping control chars */
 113         /* (can grow x2 max) */
 114         char parsebuf[MAX_READ*2];
 115         /* ...then sprintf into printbuf, adding timestamp (15 chars),
 116          * host (64), fac.prio (20) to the message */
 117         /* (growth by: 15 + 64 + 20 + delims = ~110) */
 118         char printbuf[MAX_READ*2 + 128];
 119 };
 120
 121 static const struct init_globals init_data = {
 122         .logFilePath = "/var/log/messages",
 123         .logFD = -1,
 124 #ifdef SYSLOGD_MARK
 125         .markInterval = 20 * 60,
 126 #endif
 127         .logLevel = 8,
 128 #if ENABLE_FEATURE_ROTATE_LOGFILE
 129         .logFileSize = 200 * 1024,
 130         .logFileRotate = 1,
 131 #endif
 132 #if ENABLE_FEATURE_IPC_SYSLOG
 133         .shmid = -1,
 134         .s_semid = -1,
 135         .shm_size = ((CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE)*1024), // default shm size
 136         .SMwup = { {1, -1, IPC_NOWAIT} },
 137         .SMwdn = { {0, 0}, {1, 0}, {1, +1} },
 138 #endif
 139 };
 140
 141 #define G (*ptr_to_globals)
 142 #define INIT_G() do { \
 143         SET_PTR_TO_GLOBALS(memcpy(xzalloc(sizeof(G)), &init_data, sizeof(init_data))); \
 144 } while (0)
 145
 146
 147 /* Options */
 148 enum {
 149         OPTBIT_mark = 0, // -m
 150         OPTBIT_nofork, // -n
 151         OPTBIT_outfile, // -O
 152         OPTBIT_loglevel, // -l
 153         OPTBIT_small, // -S
 154         IF_FEATURE_ROTATE_LOGFILE(OPTBIT_filesize   ,)  // -s
 155         IF_FEATURE_ROTATE_LOGFILE(OPTBIT_rotatecnt  ,)  // -b
 156         IF_FEATURE_REMOTE_LOG(    OPTBIT_remotelog  ,)  // -R
 157         IF_FEATURE_REMOTE_LOG(    OPTBIT_locallog   ,)  // -L
 158         IF_FEATURE_IPC_SYSLOG(    OPTBIT_circularlog,)  // -C
 159         IF_FEATURE_SYSLOGD_DUP(   OPTBIT_dup        ,)  // -D
 160
 161         OPT_mark        = 1 << OPTBIT_mark    ,
 162         OPT_nofork      = 1 << OPTBIT_nofork  ,
 163         OPT_outfile     = 1 << OPTBIT_outfile ,
 164         OPT_loglevel    = 1 << OPTBIT_loglevel,
 165         OPT_small       = 1 << OPTBIT_small   ,
 166         OPT_filesize    = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_filesize   )) + 0,
 167         OPT_rotatecnt   = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_rotatecnt  )) + 0,
 168         OPT_remotelog   = IF_FEATURE_REMOTE_LOG(    (1 << OPTBIT_remotelog  )) + 0,
 169         OPT_locallog    = IF_FEATURE_REMOTE_LOG(    (1 << OPTBIT_locallog   )) + 0,
 170         OPT_circularlog = IF_FEATURE_IPC_SYSLOG(    (1 << OPTBIT_circularlog)) + 0,
 171         OPT_dup         = IF_FEATURE_SYSLOGD_DUP(   (1 << OPTBIT_dup        )) + 0,
 172 };
 173 #define OPTION_STR "m:nO:l:S" \
 174         IF_FEATURE_ROTATE_LOGFILE("s:" ) \
 175         IF_FEATURE_ROTATE_LOGFILE("b:" ) \
 176         IF_FEATURE_REMOTE_LOG(    "R:" ) \
 177         IF_FEATURE_REMOTE_LOG(    "L"  ) \
 178         IF_FEATURE_IPC_SYSLOG(    "C::") \
 179         IF_FEATURE_SYSLOGD_DUP(   "D"  )
 180 #define OPTION_DECL *opt_m, *opt_l \
 181         IF_FEATURE_ROTATE_LOGFILE(,*opt_s) \
 182         IF_FEATURE_ROTATE_LOGFILE(,*opt_b) \
 183         IF_FEATURE_IPC_SYSLOG(    ,*opt_C = NULL)
 184 #define OPTION_PARAM &opt_m, &G.logFilePath, &opt_l \
 185         IF_FEATURE_ROTATE_LOGFILE(,&opt_s) \
 186         IF_FEATURE_ROTATE_LOGFILE(,&opt_b) \
 187         IF_FEATURE_REMOTE_LOG(    ,&remoteAddrList) \
 188         IF_FEATURE_IPC_SYSLOG(    ,&opt_C)
 189
 190
 191 /* circular buffer variables/structures */
 192 #if ENABLE_FEATURE_IPC_SYSLOG
 193
 194 #if CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE < 4
 195 #error Sorry, you must set the syslogd buffer size to at least 4KB.
 196 #error Please check CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE
 197 #endif
 198
 199 /* our shared key (syslogd.c and logread.c must be in sync) */
 200 enum { KEY_ID = 0x414e4547 }; /* "GENA" */
 201
 202 static void ipcsyslog_cleanup(void)
 203 {
 204         if (G.shmid != -1) {
 205                 shmdt(G.shbuf);
 206         }
 207         if (G.shmid != -1) {
 208                 shmctl(G.shmid, IPC_RMID, NULL);
 209         }
 210         if (G.s_semid != -1) {
 211                 semctl(G.s_semid, 0, IPC_RMID, 0);
 212         }
 213 }
 214
 215 static void ipcsyslog_init(void)
 216 {
 217         if (DEBUG)
 218                 printf("shmget(%x, %d,...)\n", (int)KEY_ID, G.shm_size);
 219
 220         G.shmid = shmget(KEY_ID, G.shm_size, IPC_CREAT | 0644);
 221         if (G.shmid == -1) {
 222                 bb_perror_msg_and_die("shmget");
 223         }
 224
 225         G.shbuf = shmat(G.shmid, NULL, 0);
 226         if (G.shbuf == (void*) -1L) { /* shmat has bizarre error return */
 227                 bb_perror_msg_and_die("shmat");
 228         }
 229
 230         memset(G.shbuf, 0, G.shm_size);
 231         G.shbuf->size = G.shm_size - offsetof(struct shbuf_ds, data) - 1;
 232         /*G.shbuf->tail = 0;*/
 233
 234         // we'll trust the OS to set initial semval to 0 (let's hope)
 235         G.s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023);
 236         if (G.s_semid == -1) {
 237                 if (errno == EEXIST) {
 238                         G.s_semid = semget(KEY_ID, 2, 0);
 239                         if (G.s_semid != -1)
 240                                 return;
 241                 }
 242                 bb_perror_msg_and_die("semget");
 243         }
 244 }
 245
 246 /* Write message to shared mem buffer */
 247 static void log_to_shmem(const char *msg, int len)
 248 {
 249         int old_tail, new_tail;
 250
 251         if (semop(G.s_semid, G.SMwdn, 3) == -1) {
 252                 bb_perror_msg_and_die("SMwdn");
 253         }
 254
 255         /* Circular Buffer Algorithm:
 256          * --------------------------
 257          * tail == position where to store next syslog message.
 258          * tail's max value is (shbuf->size - 1)
 259          * Last byte of buffer is never used and remains NUL.
 260          */
 261         len++; /* length with NUL included */
 262  again:
 263         old_tail = G.shbuf->tail;
 264         new_tail = old_tail + len;
 265         if (new_tail < G.shbuf->size) {
 266                 /* store message, set new tail */
 267                 memcpy(G.shbuf->data + old_tail, msg, len);
 268                 G.shbuf->tail = new_tail;
 269         } else {
 270                 /* k == available buffer space ahead of old tail */
 271                 int k = G.shbuf->size - old_tail;
 272                 /* copy what fits to the end of buffer, and repeat */
 273                 memcpy(G.shbuf->data + old_tail, msg, k);
 274                 msg += k;
 275                 len -= k;
 276                 G.shbuf->tail = 0;
 277                 goto again;
 278         }
 279         if (semop(G.s_semid, G.SMwup, 1) == -1) {
 280                 bb_perror_msg_and_die("SMwup");
 281         }
 282         if (DEBUG)
 283                 printf("tail:%d\n", G.shbuf->tail);
 284 }
 285 #else
 286 void ipcsyslog_cleanup(void);
 287 void ipcsyslog_init(void);
 288 void log_to_shmem(const char *msg);
 289 #endif /* FEATURE_IPC_SYSLOG */
 290
 291
 292 /* Print a message to the log file. */
 293 static void log_locally(time_t now, char *msg)
 294 {
 295 #ifdef SYSLOGD_WRLOCK
 296         struct flock fl;
 297 #endif
 298         int len = strlen(msg);
 299
 300 #if ENABLE_FEATURE_IPC_SYSLOG
 301         if ((option_mask32 & OPT_circularlog) && G.shbuf) {
 302                 log_to_shmem(msg, len);
 303                 return;
 304         }
 305 #endif
 306         if (G.logFD >= 0) {
 307                 /* Reopen log file every second. This allows admin
 308                  * to delete the file and not worry about restarting us.
 309                  * This costs almost nothing since it happens
 310                  * _at most_ once a second.
 311                  */
 312                 if (!now)
 313                         now = time(NULL);
 314                 if (G.last_log_time != now) {
 315                         G.last_log_time = now;
 316                         close(G.logFD);
 317                         goto reopen;
 318                 }
 319         } else {
 320  reopen:
 321                 G.logFD = open(G.logFilePath, O_WRONLY | O_CREAT
 322                                         | O_NOCTTY | O_APPEND | O_NONBLOCK,
 323                                         0666);
 324                 if (G.logFD < 0) {
 325                         /* cannot open logfile? - print to /dev/console then */
 326                         int fd = device_open(DEV_CONSOLE, O_WRONLY | O_NOCTTY | O_NONBLOCK);
 327                         if (fd < 0)
 328                                 fd = 2; /* then stderr, dammit */
 329                         full_write(fd, msg, len);
 330                         if (fd != 2)
 331                                 close(fd);
 332                         return;
 333                 }
 334 #if ENABLE_FEATURE_ROTATE_LOGFILE
 335                 {
 336                         struct stat statf;
 337                         G.isRegular = (fstat(G.logFD, &statf) == 0 && S_ISREG(statf.st_mode));
 338                         /* bug (mostly harmless): can wrap around if file > 4gb */
 339                         G.curFileSize = statf.st_size;
 340                 }
 341 #endif
 342         }
 343
 344 #ifdef SYSLOGD_WRLOCK
 345         fl.l_whence = SEEK_SET;
 346         fl.l_start = 0;
 347         fl.l_len = 1;
 348         fl.l_type = F_WRLCK;
 349         fcntl(G.logFD, F_SETLKW, &fl);
 350 #endif
 351
 352 #if ENABLE_FEATURE_ROTATE_LOGFILE
 353         if (G.logFileSize && G.isRegular && G.curFileSize > G.logFileSize) {
 354                 if (G.logFileRotate) { /* always 0..99 */
 355                         int i = strlen(G.logFilePath) + 3 + 1;
 356                         char oldFile[i];
 357                         char newFile[i];
 358                         i = G.logFileRotate - 1;
 359                         /* rename: f.8 -> f.9; f.7 -> f.8; ... */
 360                         while (1) {
 361                                 sprintf(newFile, "%s.%d", G.logFilePath, i);
 362                                 if (i == 0) break;
 363                                 sprintf(oldFile, "%s.%d", G.logFilePath, --i);
 364                                 /* ignore errors - file might be missing */
 365                                 rename(oldFile, newFile);
 366                         }
 367                         /* newFile == "f.0" now */
 368                         rename(G.logFilePath, newFile);
 369 #ifdef SYSLOGD_WRLOCK
 370                         fl.l_type = F_UNLCK;
 371                         fcntl(G.logFD, F_SETLKW, &fl);
 372 #endif
 373                         close(G.logFD);
 374                         goto reopen;
 375                 }
 376                 ftruncate(G.logFD, 0);
 377         }
 378         G.curFileSize +=
 379 #endif
 380                         full_write(G.logFD, msg, len);
 381 #ifdef SYSLOGD_WRLOCK
 382         fl.l_type = F_UNLCK;
 383         fcntl(G.logFD, F_SETLKW, &fl);
 384 #endif
 385 }
 386
 387 static void parse_fac_prio_20(int pri, char *res20)
 388 {
 389         const CODE *c_pri, *c_fac;
 390
 391         if (pri != 0) {
 392                 c_fac = facilitynames;
 393                 while (c_fac->c_name) {
 394                         if (c_fac->c_val != (LOG_FAC(pri) << 3)) {
 395                                 c_fac++;
 396                                 continue;
 397                         }
 398                         /* facility is found, look for prio */
 399                         c_pri = prioritynames;
 400                         while (c_pri->c_name) {
 401                                 if (c_pri->c_val != LOG_PRI(pri)) {
 402                                         c_pri++;
 403                                         continue;
 404                                 }
 405                                 snprintf(res20, 20, "%s.%s",
 406                                                 c_fac->c_name, c_pri->c_name);
 407                                 return;
 408                         }
 409                         /* prio not found, bail out */
 410                         break;
 411                 }
 412                 snprintf(res20, 20, "<%d>", pri);
 413         }
 414 }
 415
 416 /* len parameter is used only for "is there a timestamp?" check.
 417  * NB: some callers cheat and supply len==0 when they know
 418  * that there is no timestamp, short-circuiting the test. */
 419 static void timestamp_and_log(int pri, char *msg, int len)
 420 {
 421         char *timestamp;
 422         time_t now;
 423
 424         /* Jan 18 00:11:22 msg... */
 425         /* 01234567890123456 */
 426         if (len < 16 || msg[3] != ' ' || msg[6] != ' '
 427          || msg[9] != ':' || msg[12] != ':' || msg[15] != ' '
 428         ) {
 429                 time(&now);
 430                 timestamp = ctime(&now) + 4; /* skip day of week */
 431         } else {
 432                 now = 0;
 433                 timestamp = msg;
 434                 msg += 16;
 435         }
 436         timestamp[15] = '\0';
 437
 438         if (option_mask32 & OPT_small)
 439                 sprintf(G.printbuf, "%s %s\n", timestamp, msg);
 440         else {
 441                 char res[20];
 442                 parse_fac_prio_20(pri, res);
 443                 sprintf(G.printbuf, "%s %.64s %s %s\n", timestamp, G.hostname, res, msg);
 444         }
 445
 446         /* Log message locally (to file or shared mem) */
 447         log_locally(now, G.printbuf);
 448 }
 449
 450 static void timestamp_and_log_internal(const char *msg)
 451 {
 452         /* -L, or no -R */
 453         if (ENABLE_FEATURE_REMOTE_LOG && !(option_mask32 & OPT_locallog))
 454                 return;
 455         timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)msg, 0);
 456 }
 457
 458 /* tmpbuf[len] is a NUL byte (set by caller), but there can be other,
 459  * embedded NULs. Split messages on each of these NULs, parse prio,
 460  * escape control chars and log each locally. */
 461 static void split_escape_and_log(char *tmpbuf, int len)
 462 {
 463         char *p = tmpbuf;
 464
 465         tmpbuf += len;
 466         while (p < tmpbuf) {
 467                 char c;
 468                 char *q = G.parsebuf;
 469                 int pri = (LOG_USER | LOG_NOTICE);
 470
 471                 if (*p == '<') {
 472                         /* Parse the magic priority number */
 473                         pri = bb_strtou(p + 1, &p, 10);
 474                         if (*p == '>')
 475                                 p++;
 476                         if (pri & ~(LOG_FACMASK | LOG_PRIMASK))
 477                                 pri = (LOG_USER | LOG_NOTICE);
 478                 }
 479
 480                 while ((c = *p++)) {
 481                         if (c == '\n')
 482                                 c = ' ';
 483                         if (!(c & ~0x1f) && c != '\t') {
 484                                 *q++ = '^';
 485                                 c += '@'; /* ^@, ^A, ^B... */
 486                         }
 487                         *q++ = c;
 488                 }
 489                 *q = '\0';
 490
 491                 /* Now log it */
 492                 if (LOG_PRI(pri) < G.logLevel)
 493                         timestamp_and_log(pri, G.parsebuf, q - G.parsebuf);
 494         }
 495 }
 496
 497 #ifdef SYSLOGD_MARK
 498 static void do_mark(int sig)
 499 {
 500         if (G.markInterval) {
 501                 timestamp_and_log_internal("-- MARK --");
 502                 alarm(G.markInterval);
 503         }
 504 }
 505 #endif
 506
 507 /* Don't inline: prevent struct sockaddr_un to take up space on stack
 508  * permanently */
 509 static NOINLINE int create_socket(void)
 510 {
 511         struct sockaddr_un sunx;
 512         int sock_fd;
 513         char *dev_log_name;
 514
 515         memset(&sunx, 0, sizeof(sunx));
 516         sunx.sun_family = AF_UNIX;
 517
 518         /* Unlink old /dev/log or object it points to. */
 519         /* (if it exists, bind will fail) */
 520         strcpy(sunx.sun_path, "/dev/log");
 521         dev_log_name = xmalloc_follow_symlinks("/dev/log");
 522         if (dev_log_name) {
 523                 safe_strncpy(sunx.sun_path, dev_log_name, sizeof(sunx.sun_path));
 524                 free(dev_log_name);
 525         }
 526         unlink(sunx.sun_path);
 527
 528         sock_fd = xsocket(AF_UNIX, SOCK_DGRAM, 0);
 529         xbind(sock_fd, (struct sockaddr *) &sunx, sizeof(sunx));
 530         chmod("/dev/log", 0666);
 531
 532         return sock_fd;
 533 }
 534
 535 #if ENABLE_FEATURE_REMOTE_LOG
 536 static int try_to_resolve_remote(remoteHost_t *rh)
 537 {
 538         if (!rh->remoteAddr) {
 539                 unsigned now = monotonic_sec();
 540
 541                 /* Don't resolve name too often - DNS timeouts can be big */
 542                 if ((now - rh->last_dns_resolve) < DNS_WAIT_SEC)
 543                         return -1;
 544                 rh->last_dns_resolve = now;
 545                 rh->remoteAddr = host2sockaddr(rh->remoteHostname, 514);
 546                 if (!rh->remoteAddr)
 547                         return -1;
 548         }
 549         return socket(rh->remoteAddr->u.sa.sa_family, SOCK_DGRAM, 0);
 550 }
 551 #endif
 552
 553 static void do_syslogd(void) NORETURN;
 554 static void do_syslogd(void)
 555 {
 556         int sock_fd;
 557 #if ENABLE_FEATURE_REMOTE_LOG
 558         llist_t *item;
 559 #endif
 560 #if ENABLE_FEATURE_SYSLOGD_DUP
 561         int last_sz = -1;
 562         char *last_buf;
 563         char *recvbuf = G.recvbuf;
 564 #else
 565 #define recvbuf (G.recvbuf)
 566 #endif
 567
 568         /* Set up signal handlers (so that they interrupt read()) */
 569         signal_no_SA_RESTART_empty_mask(SIGTERM, record_signo);
 570         signal_no_SA_RESTART_empty_mask(SIGINT, record_signo);
 571         //signal_no_SA_RESTART_empty_mask(SIGQUIT, record_signo);
 572         signal(SIGHUP, SIG_IGN);
 573 #ifdef SYSLOGD_MARK
 574         signal(SIGALRM, do_mark);
 575         alarm(G.markInterval);
 576 #endif
 577         sock_fd = create_socket();
 578
 579         if (ENABLE_FEATURE_IPC_SYSLOG && (option_mask32 & OPT_circularlog)) {
 580                 ipcsyslog_init();
 581         }
 582
 583         timestamp_and_log_internal("syslogd started: BusyBox v" BB_VER);
 584
 585         while (!bb_got_signal) {
 586                 ssize_t sz;
 587
 588 #if ENABLE_FEATURE_SYSLOGD_DUP
 589                 last_buf = recvbuf;
 590                 if (recvbuf == G.recvbuf)
 591                         recvbuf = G.recvbuf + MAX_READ;
 592                 else
 593                         recvbuf = G.recvbuf;
 594 #endif
 595  read_again:
 596                 sz = read(sock_fd, recvbuf, MAX_READ - 1);
 597                 if (sz < 0) {
 598                         if (!bb_got_signal)
 599                                 bb_perror_msg("read from /dev/log");
 600                         break;
 601                 }
 602
 603                 /* Drop trailing '\n' and NULs (typically there is one NUL) */
 604                 while (1) {
 605                         if (sz == 0)
 606                                 goto read_again;
 607                         /* man 3 syslog says: "A trailing newline is added when needed".
 608                          * However, neither glibc nor uclibc do this:
 609                          * syslog(prio, "test")   sends "test\0" to /dev/log,
 610                          * syslog(prio, "test\n") sends "test\n\0".
 611                          * IOW: newline is passed verbatim!
 612                          * I take it to mean that it's syslogd's job
 613                          * to make those look identical in the log files. */
 614                         if (recvbuf[sz-1] != '\0' && recvbuf[sz-1] != '\n')
 615                                 break;
 616                         sz--;
 617                 }
 618 #if ENABLE_FEATURE_SYSLOGD_DUP
 619                 if ((option_mask32 & OPT_dup) && (sz == last_sz))
 620                         if (memcmp(last_buf, recvbuf, sz) == 0)
 621                                 continue;
 622                 last_sz = sz;
 623 #endif
 624 #if ENABLE_FEATURE_REMOTE_LOG
 625                 /* Stock syslogd sends it '\n'-terminated
 626                  * over network, mimic that */
 627                 recvbuf[sz] = '\n';
 628
 629                 /* We are not modifying log messages in any way before send */
 630                 /* Remote site cannot trust _us_ anyway and need to do validation again */
 631                 for (item = G.remoteHosts; item != NULL; item = item->link) {
 632                         remoteHost_t *rh = (remoteHost_t *)item->data;
 633
 634                         if (rh->remoteFD == -1) {
 635                                 rh->remoteFD = try_to_resolve_remote(rh);
 636                                 if (rh->remoteFD == -1)
 637                                         continue;
 638                         }
 639                         /* Send message to remote logger, ignore possible error */
 640                         /* TODO: on some errors, close and set G.remoteFD to -1
 641                          * so that DNS resolution and connect is retried? */
 642                         sendto(rh->remoteFD, recvbuf, sz+1, MSG_DONTWAIT,
 643                                 &(rh->remoteAddr->u.sa), rh->remoteAddr->len);
 644                 }
 645 #endif
 646                 if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) {
 647                         recvbuf[sz] = '\0'; /* ensure it *is* NUL terminated */
 648                         split_escape_and_log(recvbuf, sz);
 649                 }
 650         } /* while (!bb_got_signal) */
 651
 652         timestamp_and_log_internal("syslogd exiting");
 653         puts("syslogd exiting");
 654         if (ENABLE_FEATURE_IPC_SYSLOG)
 655                 ipcsyslog_cleanup();
 656         kill_myself_with_sig(bb_got_signal);
 657 #undef recvbuf
 658 }
 659
 660 int syslogd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 661 int syslogd_main(int argc UNUSED_PARAM, char **argv)
 662 {
 663         int opts;
 664         char OPTION_DECL;
 665 #if ENABLE_FEATURE_REMOTE_LOG
 666         llist_t *remoteAddrList = NULL;
 667 #endif
 668
 669         INIT_G();
 670
 671         /* No non-option params, -R can occur multiple times */
 672         opt_complementary = "=0" IF_FEATURE_REMOTE_LOG(":R::");
 673         opts = getopt32(argv, OPTION_STR, OPTION_PARAM);
 674 #if ENABLE_FEATURE_REMOTE_LOG
 675         while (remoteAddrList) {
 676                 remoteHost_t *rh = xzalloc(sizeof(*rh));
 677                 rh->remoteHostname = llist_pop(&remoteAddrList);
 678                 rh->remoteFD = -1;
 679                 rh->last_dns_resolve = monotonic_sec() - DNS_WAIT_SEC - 1;
 680                 llist_add_to(&G.remoteHosts, rh);
 681         }
 682 #endif
 683
 684 #ifdef SYSLOGD_MARK
 685         if (opts & OPT_mark) // -m
 686                 G.markInterval = xatou_range(opt_m, 0, INT_MAX/60) * 60;
 687 #endif
 688         //if (opts & OPT_nofork) // -n
 689         //if (opts & OPT_outfile) // -O
 690         if (opts & OPT_loglevel) // -l
 691                 G.logLevel = xatou_range(opt_l, 1, 8);
 692         //if (opts & OPT_small) // -S
 693 #if ENABLE_FEATURE_ROTATE_LOGFILE
 694         if (opts & OPT_filesize) // -s
 695                 G.logFileSize = xatou_range(opt_s, 0, INT_MAX/1024) * 1024;
 696         if (opts & OPT_rotatecnt) // -b
 697                 G.logFileRotate = xatou_range(opt_b, 0, 99);
 698 #endif
 699 #if ENABLE_FEATURE_IPC_SYSLOG
 700         if (opt_C) // -Cn
 701                 G.shm_size = xatoul_range(opt_C, 4, INT_MAX/1024) * 1024;
 702 #endif
 703
 704         /* If they have not specified remote logging, then log locally */
 705         if (ENABLE_FEATURE_REMOTE_LOG && !(opts & OPT_remotelog)) // -R
 706                 option_mask32 |= OPT_locallog;
 707
 708         /* Store away localhost's name before the fork */
 709         G.hostname = safe_gethostname();
 710         *strchrnul(G.hostname, '.') = '\0';
 711
 712         if (!(opts & OPT_nofork)) {
 713                 bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
 714         }
 715         //umask(0); - why??
 716         write_pidfile("/var/run/syslogd.pid");
 717         do_syslogd();
 718         /* return EXIT_SUCCESS; */
 719 }
 720
 721 /* Clean up. Needed because we are included from syslogd_and_logger.c */
 722 #undef DEBUG
 723 #undef SYSLOGD_MARK
 724 #undef SYSLOGD_WRLOCK
 725 #undef G
 726 #undef GLOBALS
 727 #undef INIT_G
 728 #undef OPTION_STR
 729 #undef OPTION_DECL
 730 #undef OPTION_PARAM