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 GPLv2 or later, see file LICENSE in this source tree.
  14  */
  15
  16 //usage:#define syslogd_trivial_usage
  17 //usage:       "[OPTIONS]"
  18 //usage:#define syslogd_full_usage "\n\n"
  19 //usage:       "System logging utility\n"
  20 //usage:        IF_NOT_FEATURE_SYSLOGD_CFG(
  21 //usage:       "(this version of syslogd ignores /etc/syslog.conf)\n"
  22 //usage:        )
  23 //usage:     "\n        -n              Run in foreground"
  24 //usage:     "\n        -O FILE         Log to FILE (default:/var/log/messages)"
  25 //usage:     "\n        -l N            Log only messages more urgent than prio N (1-8)"
  26 //usage:     "\n        -S              Smaller output"
  27 //usage:        IF_FEATURE_ROTATE_LOGFILE(
  28 //usage:     "\n        -s SIZE         Max size (KB) before rotation (default:200KB, 0=off)"
  29 //usage:     "\n        -b N            N rotated logs to keep (default:1, max=99, 0=purge)"
  30 //usage:        )
  31 //usage:        IF_FEATURE_REMOTE_LOG(
  32 //usage:     "\n        -R HOST[:PORT]  Log to IP or hostname on PORT (default PORT=514/UDP)"
  33 //usage:     "\n        -L              Log locally and via network (default is network only if -R)"
  34 //usage:        )
  35 //usage:        IF_FEATURE_SYSLOGD_DUP(
  36 //usage:     "\n        -D              Drop duplicates"
  37 //usage:        )
  38 //usage:        IF_FEATURE_IPC_SYSLOG(
  39 /* NB: -Csize shouldn't have space (because size is optional) */
  40 //usage:     "\n        -C[size_kb]     Log to shared mem buffer (use logread to read it)"
  41 //usage:        )
  42 //usage:        IF_FEATURE_SYSLOGD_CFG(
  43 //usage:     "\n        -f FILE         Use FILE as config (default:/etc/syslog.conf)"
  44 //usage:        )
  45 /* //usage:  "\n        -m MIN          Minutes between MARK lines (default:20, 0=off)" */
  46 //usage:
  47 //usage:#define syslogd_example_usage
  48 //usage:       "$ syslogd -R masterlog:514\n"
  49 //usage:       "$ syslogd -R 192.168.1.1:601\n"
  50
  51 /*
  52  * Done in syslogd_and_logger.c:
  53 #include "libbb.h"
  54 #define SYSLOG_NAMES
  55 #define SYSLOG_NAMES_CONST
  56 #include <syslog.h>
  57 */
  58
  59 #include <sys/un.h>
  60 #include <sys/uio.h>
  61
  62 #if ENABLE_FEATURE_REMOTE_LOG
  63 #include <netinet/in.h>
  64 #endif
  65
  66 #if ENABLE_FEATURE_IPC_SYSLOG
  67 #include <sys/ipc.h>
  68 #include <sys/sem.h>
  69 #include <sys/shm.h>
  70 #endif
  71
  72
  73 #define DEBUG 0
  74
  75 /* MARK code is not very useful, is bloat, and broken:
  76  * can deadlock if alarmed to make MARK while writing to IPC buffer
  77  * (semaphores are down but do_mark routine tries to down them again) */
  78 #undef SYSLOGD_MARK
  79
  80 /* Write locking does not seem to be useful either */
  81 #undef SYSLOGD_WRLOCK
  82
  83 enum {
  84         MAX_READ = CONFIG_FEATURE_SYSLOGD_READ_BUFFER_SIZE,
  85         DNS_WAIT_SEC = 2 * 60,
  86 };
  87
  88 /* Semaphore operation structures */
  89 struct shbuf_ds {
  90         int32_t size;   /* size of data - 1 */
  91         int32_t tail;   /* end of message list */
  92         char data[1];   /* data/messages */
  93 };
  94
  95 #if ENABLE_FEATURE_REMOTE_LOG
  96 typedef struct {
  97         int remoteFD;
  98         unsigned last_dns_resolve;
  99         len_and_sockaddr *remoteAddr;
 100         const char *remoteHostname;
 101 } remoteHost_t;
 102 #endif
 103
 104 typedef struct logFile_t {
 105         const char *path;
 106         int fd;
 107 #if ENABLE_FEATURE_ROTATE_LOGFILE
 108         unsigned size;
 109         uint8_t isRegular;
 110 #endif
 111 } logFile_t;
 112
 113 #if ENABLE_FEATURE_SYSLOGD_CFG
 114 typedef struct logRule_t {
 115         uint8_t enabled_facility_priomap[LOG_NFACILITIES];
 116         struct logFile_t *file;
 117         struct logRule_t *next;
 118 } logRule_t;
 119 #endif
 120
 121 /* Allows us to have smaller initializer. Ugly. */
 122 #define GLOBALS \
 123         logFile_t logFile;                      \
 124         /* interval between marks in seconds */ \
 125         /*int markInterval;*/                   \
 126         /* level of messages to be logged */    \
 127         int logLevel;                           \
 128 IF_FEATURE_ROTATE_LOGFILE( \
 129         /* max size of file before rotation */  \
 130         unsigned logFileSize;                   \
 131         /* number of rotated message files */   \
 132         unsigned logFileRotate;                 \
 133 ) \
 134 IF_FEATURE_IPC_SYSLOG( \
 135         int shmid; /* ipc shared memory id */   \
 136         int s_semid; /* ipc semaphore id */     \
 137         int shm_size;                           \
 138         struct sembuf SMwup[1];                 \
 139         struct sembuf SMwdn[3];                 \
 140 ) \
 141 IF_FEATURE_SYSLOGD_CFG( \
 142         logRule_t *log_rules; \
 143 )
 144
 145 struct init_globals {
 146         GLOBALS
 147 };
 148
 149 struct globals {
 150         GLOBALS
 151
 152 #if ENABLE_FEATURE_REMOTE_LOG
 153         llist_t *remoteHosts;
 154 #endif
 155 #if ENABLE_FEATURE_IPC_SYSLOG
 156         struct shbuf_ds *shbuf;
 157 #endif
 158         time_t last_log_time;
 159         /* localhost's name. We print only first 64 chars */
 160         char *hostname;
 161
 162         /* We recv into recvbuf... */
 163         char recvbuf[MAX_READ * (1 + ENABLE_FEATURE_SYSLOGD_DUP)];
 164         /* ...then copy to parsebuf, escaping control chars */
 165         /* (can grow x2 max) */
 166         char parsebuf[MAX_READ*2];
 167         /* ...then sprintf into printbuf, adding timestamp (15 chars),
 168          * host (64), fac.prio (20) to the message */
 169         /* (growth by: 15 + 64 + 20 + delims = ~110) */
 170         char printbuf[MAX_READ*2 + 128];
 171 };
 172
 173 static const struct init_globals init_data = {
 174         .logFile = {
 175                 .path = "/var/log/messages",
 176                 .fd = -1,
 177         },
 178 #ifdef SYSLOGD_MARK
 179         .markInterval = 20 * 60,
 180 #endif
 181         .logLevel = 8,
 182 #if ENABLE_FEATURE_ROTATE_LOGFILE
 183         .logFileSize = 200 * 1024,
 184         .logFileRotate = 1,
 185 #endif
 186 #if ENABLE_FEATURE_IPC_SYSLOG
 187         .shmid = -1,
 188         .s_semid = -1,
 189         .shm_size = ((CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE)*1024), /* default shm size */
 190         .SMwup = { {1, -1, IPC_NOWAIT} },
 191         .SMwdn = { {0, 0}, {1, 0}, {1, +1} },
 192 #endif
 193 };
 194
 195 #define G (*ptr_to_globals)
 196 #define INIT_G() do { \
 197         SET_PTR_TO_GLOBALS(memcpy(xzalloc(sizeof(G)), &init_data, sizeof(init_data))); \
 198 } while (0)
 199
 200
 201 /* Options */
 202 enum {
 203         OPTBIT_mark = 0, // -m
 204         OPTBIT_nofork, // -n
 205         OPTBIT_outfile, // -O
 206         OPTBIT_loglevel, // -l
 207         OPTBIT_small, // -S
 208         IF_FEATURE_ROTATE_LOGFILE(OPTBIT_filesize   ,)  // -s
 209         IF_FEATURE_ROTATE_LOGFILE(OPTBIT_rotatecnt  ,)  // -b
 210         IF_FEATURE_REMOTE_LOG(    OPTBIT_remotelog  ,)  // -R
 211         IF_FEATURE_REMOTE_LOG(    OPTBIT_locallog   ,)  // -L
 212         IF_FEATURE_IPC_SYSLOG(    OPTBIT_circularlog,)  // -C
 213         IF_FEATURE_SYSLOGD_DUP(   OPTBIT_dup        ,)  // -D
 214         IF_FEATURE_SYSLOGD_CFG(   OPTBIT_cfg        ,)  // -f
 215
 216         OPT_mark        = 1 << OPTBIT_mark    ,
 217         OPT_nofork      = 1 << OPTBIT_nofork  ,
 218         OPT_outfile     = 1 << OPTBIT_outfile ,
 219         OPT_loglevel    = 1 << OPTBIT_loglevel,
 220         OPT_small       = 1 << OPTBIT_small   ,
 221         OPT_filesize    = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_filesize   )) + 0,
 222         OPT_rotatecnt   = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_rotatecnt  )) + 0,
 223         OPT_remotelog   = IF_FEATURE_REMOTE_LOG(    (1 << OPTBIT_remotelog  )) + 0,
 224         OPT_locallog    = IF_FEATURE_REMOTE_LOG(    (1 << OPTBIT_locallog   )) + 0,
 225         OPT_circularlog = IF_FEATURE_IPC_SYSLOG(    (1 << OPTBIT_circularlog)) + 0,
 226         OPT_dup         = IF_FEATURE_SYSLOGD_DUP(   (1 << OPTBIT_dup        )) + 0,
 227         OPT_cfg         = IF_FEATURE_SYSLOGD_CFG(   (1 << OPTBIT_cfg        )) + 0,
 228 };
 229 #define OPTION_STR "m:nO:l:S" \
 230         IF_FEATURE_ROTATE_LOGFILE("s:" ) \
 231         IF_FEATURE_ROTATE_LOGFILE("b:" ) \
 232         IF_FEATURE_REMOTE_LOG(    "R:" ) \
 233         IF_FEATURE_REMOTE_LOG(    "L"  ) \
 234         IF_FEATURE_IPC_SYSLOG(    "C::") \
 235         IF_FEATURE_SYSLOGD_DUP(   "D"  ) \
 236         IF_FEATURE_SYSLOGD_CFG(   "f:"  )
 237 #define OPTION_DECL *opt_m, *opt_l \
 238         IF_FEATURE_ROTATE_LOGFILE(,*opt_s) \
 239         IF_FEATURE_ROTATE_LOGFILE(,*opt_b) \
 240         IF_FEATURE_IPC_SYSLOG(    ,*opt_C = NULL) \
 241         IF_FEATURE_SYSLOGD_CFG(   ,*opt_f = NULL)
 242 #define OPTION_PARAM &opt_m, &(G.logFile.path), &opt_l \
 243         IF_FEATURE_ROTATE_LOGFILE(,&opt_s) \
 244         IF_FEATURE_ROTATE_LOGFILE(,&opt_b) \
 245         IF_FEATURE_REMOTE_LOG(    ,&remoteAddrList) \
 246         IF_FEATURE_IPC_SYSLOG(    ,&opt_C) \
 247         IF_FEATURE_SYSLOGD_CFG(   ,&opt_f)
 248
 249
 250 #if ENABLE_FEATURE_SYSLOGD_CFG
 251 static const CODE* find_by_name(char *name, const CODE* c_set)
 252 {
 253         for (; c_set->c_name; c_set++) {
 254                 if (strcmp(name, c_set->c_name) == 0)
 255                         return c_set;
 256         }
 257         return NULL;
 258 }
 259 #endif
 260 static const CODE* find_by_val(int val, const CODE* c_set)
 261 {
 262         for (; c_set->c_name; c_set++) {
 263                 if (c_set->c_val == val)
 264                         return c_set;
 265         }
 266         return NULL;
 267 }
 268
 269 #if ENABLE_FEATURE_SYSLOGD_CFG
 270 static void parse_syslogdcfg(const char *file)
 271 {
 272         char *t;
 273         logRule_t **pp_rule;
 274         /* tok[0] set of selectors */
 275         /* tok[1] file name */
 276         /* tok[2] has to be NULL */
 277         char *tok[3];
 278         parser_t *parser;
 279
 280         parser = config_open2(file ? file : "/etc/syslog.conf",
 281                                 file ? xfopen_for_read : fopen_for_read);
 282         if (!parser)
 283                 /* didn't find default /etc/syslog.conf */
 284                 /* proceed as if we built busybox without config support */
 285                 return;
 286
 287         /* use ptr to ptr to avoid checking whether head was initialized */
 288         pp_rule = &G.log_rules;
 289         /* iterate through lines of config, skipping comments */
 290         while (config_read(parser, tok, 3, 2, "# \t", PARSE_NORMAL | PARSE_MIN_DIE)) {
 291                 char *cur_selector;
 292                 logRule_t *cur_rule;
 293
 294                 /* unexpected trailing token? */
 295                 if (tok[2])
 296                         goto cfgerr;
 297
 298                 cur_rule = *pp_rule = xzalloc(sizeof(*cur_rule));
 299
 300                 cur_selector = tok[0];
 301                 /* iterate through selectors: "kern.info;kern.!err;..." */
 302                 do {
 303                         const CODE *code;
 304                         char *next_selector;
 305                         uint8_t negated_prio; /* "kern.!err" */
 306                         uint8_t single_prio;  /* "kern.=err" */
 307                         uint32_t facmap; /* bitmap of enabled facilities */
 308                         uint8_t primap;  /* bitmap of enabled priorities */
 309                         unsigned i;
 310
 311                         next_selector = strchr(cur_selector, ';');
 312                         if (next_selector)
 313                                 *next_selector++ = '\0';
 314
 315                         t = strchr(cur_selector, '.');
 316                         if (!t)
 317                                 goto cfgerr;
 318                         *t++ = '\0'; /* separate facility from priority */
 319
 320                         negated_prio = 0;
 321                         single_prio = 0;
 322                         if (*t == '!') {
 323                                 negated_prio = 1;
 324                                 ++t;
 325                         }
 326                         if (*t == '=') {
 327                                 single_prio = 1;
 328                                 ++t;
 329                         }
 330
 331                         /* parse priority */
 332                         if (*t == '*')
 333                                 primap = 0xff; /* all 8 log levels enabled */
 334                         else {
 335                                 uint8_t priority;
 336                                 code = find_by_name(t, prioritynames);
 337                                 if (!code)
 338                                         goto cfgerr;
 339                                 primap = 0;
 340                                 priority = code->c_val;
 341                                 if (priority == INTERNAL_NOPRI) {
 342                                         /* ensure we take "enabled_facility_priomap[fac] &= 0" branch below */
 343                                         negated_prio = 1;
 344                                 } else {
 345                                         priority = 1 << priority;
 346                                         do {
 347                                                 primap |= priority;
 348                                                 if (single_prio)
 349                                                         break;
 350                                                 priority >>= 1;
 351                                         } while (priority);
 352                                         if (negated_prio)
 353                                                 primap = ~primap;
 354                                 }
 355                         }
 356
 357                         /* parse facility */
 358                         if (*cur_selector == '*')
 359                                 facmap = (1<<LOG_NFACILITIES) - 1;
 360                         else {
 361                                 char *next_facility;
 362                                 facmap = 0;
 363                                 t = cur_selector;
 364                                 /* iterate through facilities: "kern,daemon.<priospec>" */
 365                                 do {
 366                                         next_facility = strchr(t, ',');
 367                                         if (next_facility)
 368                                                 *next_facility++ = '\0';
 369                                         code = find_by_name(t, facilitynames);
 370                                         if (!code)
 371                                                 goto cfgerr;
 372                                         /* "mark" is not a real facility, skip it */
 373                                         if (code->c_val != INTERNAL_MARK)
 374                                                 facmap |= 1<<(LOG_FAC(code->c_val));
 375                                         t = next_facility;
 376                                 } while (t);
 377                         }
 378
 379                         /* merge result with previous selectors */
 380                         for (i = 0; i < LOG_NFACILITIES; ++i) {
 381                                 if (!(facmap & (1<<i)))
 382                                         continue;
 383                                 if (negated_prio)
 384                                         cur_rule->enabled_facility_priomap[i] &= primap;
 385                                 else
 386                                         cur_rule->enabled_facility_priomap[i] |= primap;
 387                         }
 388
 389                         cur_selector = next_selector;
 390                 } while (cur_selector);
 391
 392                 /* check whether current file name was mentioned in previous rules or
 393                  * as global logfile (G.logFile).
 394                  */
 395                 if (strcmp(G.logFile.path, tok[1]) == 0) {
 396                         cur_rule->file = &G.logFile;
 397                         goto found;
 398                 }
 399                 /* temporarily use cur_rule as iterator, but *pp_rule still points
 400                  * to currently processing rule entry.
 401                  * NOTE: *pp_rule points to the current (and last in the list) rule.
 402                  */
 403                 for (cur_rule = G.log_rules; cur_rule != *pp_rule; cur_rule = cur_rule->next) {
 404                         if (strcmp(cur_rule->file->path, tok[1]) == 0) {
 405                                 /* found - reuse the same file structure */
 406                                 (*pp_rule)->file = cur_rule->file;
 407                                 cur_rule = *pp_rule;
 408                                 goto found;
 409                         }
 410                 }
 411                 cur_rule->file = xzalloc(sizeof(*cur_rule->file));
 412                 cur_rule->file->fd = -1;
 413                 cur_rule->file->path = xstrdup(tok[1]);
 414  found:
 415                 pp_rule = &cur_rule->next;
 416         }
 417         config_close(parser);
 418         return;
 419
 420  cfgerr:
 421         bb_error_msg_and_die("error in '%s' at line %d", file, parser->lineno);
 422 }
 423 #endif
 424
 425 /* circular buffer variables/structures */
 426 #if ENABLE_FEATURE_IPC_SYSLOG
 427
 428 #if CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE < 4
 429 #error Sorry, you must set the syslogd buffer size to at least 4KB.
 430 #error Please check CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE
 431 #endif
 432
 433 /* our shared key (syslogd.c and logread.c must be in sync) */
 434 enum { KEY_ID = 0x414e4547 }; /* "GENA" */
 435
 436 static void ipcsyslog_cleanup(void)
 437 {
 438         if (G.shmid != -1) {
 439                 shmdt(G.shbuf);
 440         }
 441         if (G.shmid != -1) {
 442                 shmctl(G.shmid, IPC_RMID, NULL);
 443         }
 444         if (G.s_semid != -1) {
 445                 semctl(G.s_semid, 0, IPC_RMID, 0);
 446         }
 447 }
 448
 449 static void ipcsyslog_init(void)
 450 {
 451         if (DEBUG)
 452                 printf("shmget(%x, %d,...)\n", (int)KEY_ID, G.shm_size);
 453
 454         G.shmid = shmget(KEY_ID, G.shm_size, IPC_CREAT | 0644);
 455         if (G.shmid == -1) {
 456                 bb_perror_msg_and_die("shmget");
 457         }
 458
 459         G.shbuf = shmat(G.shmid, NULL, 0);
 460         if (G.shbuf == (void*) -1L) { /* shmat has bizarre error return */
 461                 bb_perror_msg_and_die("shmat");
 462         }
 463
 464         memset(G.shbuf, 0, G.shm_size);
 465         G.shbuf->size = G.shm_size - offsetof(struct shbuf_ds, data) - 1;
 466         /*G.shbuf->tail = 0;*/
 467
 468         /* we'll trust the OS to set initial semval to 0 (let's hope) */
 469         G.s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023);
 470         if (G.s_semid == -1) {
 471                 if (errno == EEXIST) {
 472                         G.s_semid = semget(KEY_ID, 2, 0);
 473                         if (G.s_semid != -1)
 474                                 return;
 475                 }
 476                 bb_perror_msg_and_die("semget");
 477         }
 478 }
 479
 480 /* Write message to shared mem buffer */
 481 static void log_to_shmem(const char *msg)
 482 {
 483         int old_tail, new_tail;
 484         int len;
 485
 486         if (semop(G.s_semid, G.SMwdn, 3) == -1) {
 487                 bb_perror_msg_and_die("SMwdn");
 488         }
 489
 490         /* Circular Buffer Algorithm:
 491          * --------------------------
 492          * tail == position where to store next syslog message.
 493          * tail's max value is (shbuf->size - 1)
 494          * Last byte of buffer is never used and remains NUL.
 495          */
 496         len = strlen(msg) + 1; /* length with NUL included */
 497  again:
 498         old_tail = G.shbuf->tail;
 499         new_tail = old_tail + len;
 500         if (new_tail < G.shbuf->size) {
 501                 /* store message, set new tail */
 502                 memcpy(G.shbuf->data + old_tail, msg, len);
 503                 G.shbuf->tail = new_tail;
 504         } else {
 505                 /* k == available buffer space ahead of old tail */
 506                 int k = G.shbuf->size - old_tail;
 507                 /* copy what fits to the end of buffer, and repeat */
 508                 memcpy(G.shbuf->data + old_tail, msg, k);
 509                 msg += k;
 510                 len -= k;
 511                 G.shbuf->tail = 0;
 512                 goto again;
 513         }
 514         if (semop(G.s_semid, G.SMwup, 1) == -1) {
 515                 bb_perror_msg_and_die("SMwup");
 516         }
 517         if (DEBUG)
 518                 printf("tail:%d\n", G.shbuf->tail);
 519 }
 520 #else
 521 void ipcsyslog_cleanup(void);
 522 void ipcsyslog_init(void);
 523 void log_to_shmem(const char *msg);
 524 #endif /* FEATURE_IPC_SYSLOG */
 525
 526 /* Print a message to the log file. */
 527 static void log_locally(time_t now, char *msg, logFile_t *log_file)
 528 {
 529 #ifdef SYSLOGD_WRLOCK
 530         struct flock fl;
 531 #endif
 532         int len = strlen(msg);
 533
 534         if (log_file->fd >= 0) {
 535                 /* Reopen log file every second. This allows admin
 536                  * to delete the file and not worry about restarting us.
 537                  * This costs almost nothing since it happens
 538                  * _at most_ once a second.
 539                  */
 540                 if (!now)
 541                         now = time(NULL);
 542                 if (G.last_log_time != now) {
 543                         G.last_log_time = now;
 544                         close(log_file->fd);
 545                         goto reopen;
 546                 }
 547         } else {
 548  reopen:
 549                 log_file->fd = open(log_file->path, O_WRONLY | O_CREAT
 550                                         | O_NOCTTY | O_APPEND | O_NONBLOCK,
 551                                         0666);
 552                 if (log_file->fd < 0) {
 553                         /* cannot open logfile? - print to /dev/console then */
 554                         int fd = device_open(DEV_CONSOLE, O_WRONLY | O_NOCTTY | O_NONBLOCK);
 555                         if (fd < 0)
 556                                 fd = 2; /* then stderr, dammit */
 557                         full_write(fd, msg, len);
 558                         if (fd != 2)
 559                                 close(fd);
 560                         return;
 561                 }
 562 #if ENABLE_FEATURE_ROTATE_LOGFILE
 563                 {
 564                         struct stat statf;
 565                         log_file->isRegular = (fstat(log_file->fd, &statf) == 0 && S_ISREG(statf.st_mode));
 566                         /* bug (mostly harmless): can wrap around if file > 4gb */
 567                         log_file->size = statf.st_size;
 568                 }
 569 #endif
 570         }
 571
 572 #ifdef SYSLOGD_WRLOCK
 573         fl.l_whence = SEEK_SET;
 574         fl.l_start = 0;
 575         fl.l_len = 1;
 576         fl.l_type = F_WRLCK;
 577         fcntl(log_file->fd, F_SETLKW, &fl);
 578 #endif
 579
 580 #if ENABLE_FEATURE_ROTATE_LOGFILE
 581         if (G.logFileSize && log_file->isRegular && log_file->size > G.logFileSize) {
 582                 if (G.logFileRotate) { /* always 0..99 */
 583                         int i = strlen(log_file->path) + 3 + 1;
 584                         char oldFile[i];
 585                         char newFile[i];
 586                         i = G.logFileRotate - 1;
 587                         /* rename: f.8 -> f.9; f.7 -> f.8; ... */
 588                         while (1) {
 589                                 sprintf(newFile, "%s.%d", log_file->path, i);
 590                                 if (i == 0) break;
 591                                 sprintf(oldFile, "%s.%d", log_file->path, --i);
 592                                 /* ignore errors - file might be missing */
 593                                 rename(oldFile, newFile);
 594                         }
 595                         /* newFile == "f.0" now */
 596                         rename(log_file->path, newFile);
 597                         /* Incredibly, if F and F.0 are hardlinks, POSIX
 598                          * _demands_ that rename returns 0 but does not
 599                          * remove F!!!
 600                          * (hardlinked F/F.0 pair was observed after
 601                          * power failure during rename()).
 602                          * Ensure old file is gone:
 603                          */
 604                         unlink(log_file->path);
 605 #ifdef SYSLOGD_WRLOCK
 606                         fl.l_type = F_UNLCK;
 607                         fcntl(log_file->fd, F_SETLKW, &fl);
 608 #endif
 609                         close(log_file->fd);
 610                         goto reopen;
 611                 }
 612                 ftruncate(log_file->fd, 0);
 613         }
 614         log_file->size +=
 615 #endif
 616                         full_write(log_file->fd, msg, len);
 617 #ifdef SYSLOGD_WRLOCK
 618         fl.l_type = F_UNLCK;
 619         fcntl(log_file->fd, F_SETLKW, &fl);
 620 #endif
 621 }
 622
 623 static void parse_fac_prio_20(int pri, char *res20)
 624 {
 625         const CODE *c_pri, *c_fac;
 626
 627         c_fac = find_by_val(LOG_FAC(pri) << 3, facilitynames);
 628         if (c_fac) {
 629                 c_pri = find_by_val(LOG_PRI(pri), prioritynames);
 630                 if (c_pri) {
 631                         snprintf(res20, 20, "%s.%s", c_fac->c_name, c_pri->c_name);
 632                         return;
 633                 }
 634         }
 635         snprintf(res20, 20, "<%d>", pri);
 636 }
 637
 638 /* len parameter is used only for "is there a timestamp?" check.
 639  * NB: some callers cheat and supply len==0 when they know
 640  * that there is no timestamp, short-circuiting the test. */
 641 static void timestamp_and_log(int pri, char *msg, int len)
 642 {
 643         char *timestamp;
 644         time_t now;
 645
 646         /* Jan 18 00:11:22 msg... */
 647         /* 01234567890123456 */
 648         if (len < 16 || msg[3] != ' ' || msg[6] != ' '
 649          || msg[9] != ':' || msg[12] != ':' || msg[15] != ' '
 650         ) {
 651                 time(&now);
 652                 timestamp = ctime(&now) + 4; /* skip day of week */
 653         } else {
 654                 now = 0;
 655                 timestamp = msg;
 656                 msg += 16;
 657         }
 658         timestamp[15] = '\0';
 659
 660         if (option_mask32 & OPT_small)
 661                 sprintf(G.printbuf, "%s %s\n", timestamp, msg);
 662         else {
 663                 char res[20];
 664                 parse_fac_prio_20(pri, res);
 665                 sprintf(G.printbuf, "%s %.64s %s %s\n", timestamp, G.hostname, res, msg);
 666         }
 667
 668         /* Log message locally (to file or shared mem) */
 669 #if ENABLE_FEATURE_SYSLOGD_CFG
 670         {
 671                 bool match = 0;
 672                 logRule_t *rule;
 673                 uint8_t facility = LOG_FAC(pri);
 674                 uint8_t prio_bit = 1 << LOG_PRI(pri);
 675
 676                 for (rule = G.log_rules; rule; rule = rule->next) {
 677                         if (rule->enabled_facility_priomap[facility] & prio_bit) {
 678                                 log_locally(now, G.printbuf, rule->file);
 679                                 match = 1;
 680                         }
 681                 }
 682                 if (match)
 683                         return;
 684         }
 685 #endif
 686         if (LOG_PRI(pri) < G.logLevel) {
 687 #if ENABLE_FEATURE_IPC_SYSLOG
 688                 if ((option_mask32 & OPT_circularlog) && G.shbuf) {
 689                         log_to_shmem(G.printbuf);
 690                         return;
 691                 }
 692 #endif
 693                 log_locally(now, G.printbuf, &G.logFile);
 694         }
 695 }
 696
 697 static void timestamp_and_log_internal(const char *msg)
 698 {
 699         /* -L, or no -R */
 700         if (ENABLE_FEATURE_REMOTE_LOG && !(option_mask32 & OPT_locallog))
 701                 return;
 702         timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)msg, 0);
 703 }
 704
 705 /* tmpbuf[len] is a NUL byte (set by caller), but there can be other,
 706  * embedded NULs. Split messages on each of these NULs, parse prio,
 707  * escape control chars and log each locally. */
 708 static void split_escape_and_log(char *tmpbuf, int len)
 709 {
 710         char *p = tmpbuf;
 711
 712         tmpbuf += len;
 713         while (p < tmpbuf) {
 714                 char c;
 715                 char *q = G.parsebuf;
 716                 int pri = (LOG_USER | LOG_NOTICE);
 717
 718                 if (*p == '<') {
 719                         /* Parse the magic priority number */
 720                         pri = bb_strtou(p + 1, &p, 10);
 721                         if (*p == '>')
 722                                 p++;
 723                         if (pri & ~(LOG_FACMASK | LOG_PRIMASK))
 724                                 pri = (LOG_USER | LOG_NOTICE);
 725                 }
 726
 727                 while ((c = *p++)) {
 728                         if (c == '\n')
 729                                 c = ' ';
 730                         if (!(c & ~0x1f) && c != '\t') {
 731                                 *q++ = '^';
 732                                 c += '@'; /* ^@, ^A, ^B... */
 733                         }
 734                         *q++ = c;
 735                 }
 736                 *q = '\0';
 737
 738                 /* Now log it */
 739                 timestamp_and_log(pri, G.parsebuf, q - G.parsebuf);
 740         }
 741 }
 742
 743 #ifdef SYSLOGD_MARK
 744 static void do_mark(int sig)
 745 {
 746         if (G.markInterval) {
 747                 timestamp_and_log_internal("-- MARK --");
 748                 alarm(G.markInterval);
 749         }
 750 }
 751 #endif
 752
 753 /* Don't inline: prevent struct sockaddr_un to take up space on stack
 754  * permanently */
 755 static NOINLINE int create_socket(void)
 756 {
 757         struct sockaddr_un sunx;
 758         int sock_fd;
 759         char *dev_log_name;
 760
 761 #if ENABLE_FEATURE_SYSTEMD
 762         if (sd_listen_fds() == 1)
 763                 return SD_LISTEN_FDS_START;
 764 #endif
 765
 766         memset(&sunx, 0, sizeof(sunx));
 767         sunx.sun_family = AF_UNIX;
 768
 769         /* Unlink old /dev/log or object it points to. */
 770         /* (if it exists, bind will fail) */
 771         strcpy(sunx.sun_path, "/dev/log");
 772         dev_log_name = xmalloc_follow_symlinks("/dev/log");
 773         if (dev_log_name) {
 774                 safe_strncpy(sunx.sun_path, dev_log_name, sizeof(sunx.sun_path));
 775                 free(dev_log_name);
 776         }
 777         unlink(sunx.sun_path);
 778
 779         sock_fd = xsocket(AF_UNIX, SOCK_DGRAM, 0);
 780         xbind(sock_fd, (struct sockaddr *) &sunx, sizeof(sunx));
 781         chmod("/dev/log", 0666);
 782
 783         return sock_fd;
 784 }
 785
 786 #if ENABLE_FEATURE_REMOTE_LOG
 787 static int try_to_resolve_remote(remoteHost_t *rh)
 788 {
 789         if (!rh->remoteAddr) {
 790                 unsigned now = monotonic_sec();
 791
 792                 /* Don't resolve name too often - DNS timeouts can be big */
 793                 if ((now - rh->last_dns_resolve) < DNS_WAIT_SEC)
 794                         return -1;
 795                 rh->last_dns_resolve = now;
 796                 rh->remoteAddr = host2sockaddr(rh->remoteHostname, 514);
 797                 if (!rh->remoteAddr)
 798                         return -1;
 799         }
 800         return xsocket(rh->remoteAddr->u.sa.sa_family, SOCK_DGRAM, 0);
 801 }
 802 #endif
 803
 804 static void do_syslogd(void) NORETURN;
 805 static void do_syslogd(void)
 806 {
 807         int sock_fd;
 808 #if ENABLE_FEATURE_REMOTE_LOG
 809         llist_t *item;
 810 #endif
 811 #if ENABLE_FEATURE_SYSLOGD_DUP
 812         int last_sz = -1;
 813         char *last_buf;
 814         char *recvbuf = G.recvbuf;
 815 #else
 816 #define recvbuf (G.recvbuf)
 817 #endif
 818
 819         /* Set up signal handlers (so that they interrupt read()) */
 820         signal_no_SA_RESTART_empty_mask(SIGTERM, record_signo);
 821         signal_no_SA_RESTART_empty_mask(SIGINT, record_signo);
 822         //signal_no_SA_RESTART_empty_mask(SIGQUIT, record_signo);
 823         signal(SIGHUP, SIG_IGN);
 824 #ifdef SYSLOGD_MARK
 825         signal(SIGALRM, do_mark);
 826         alarm(G.markInterval);
 827 #endif
 828         sock_fd = create_socket();
 829
 830         if (ENABLE_FEATURE_IPC_SYSLOG && (option_mask32 & OPT_circularlog)) {
 831                 ipcsyslog_init();
 832         }
 833
 834         timestamp_and_log_internal("syslogd started: BusyBox v" BB_VER);
 835
 836         while (!bb_got_signal) {
 837                 ssize_t sz;
 838
 839 #if ENABLE_FEATURE_SYSLOGD_DUP
 840                 last_buf = recvbuf;
 841                 if (recvbuf == G.recvbuf)
 842                         recvbuf = G.recvbuf + MAX_READ;
 843                 else
 844                         recvbuf = G.recvbuf;
 845 #endif
 846  read_again:
 847                 sz = read(sock_fd, recvbuf, MAX_READ - 1);
 848                 if (sz < 0) {
 849                         if (!bb_got_signal)
 850                                 bb_perror_msg("read from /dev/log");
 851                         break;
 852                 }
 853
 854                 /* Drop trailing '\n' and NULs (typically there is one NUL) */
 855                 while (1) {
 856                         if (sz == 0)
 857                                 goto read_again;
 858                         /* man 3 syslog says: "A trailing newline is added when needed".
 859                          * However, neither glibc nor uclibc do this:
 860                          * syslog(prio, "test")   sends "test\0" to /dev/log,
 861                          * syslog(prio, "test\n") sends "test\n\0".
 862                          * IOW: newline is passed verbatim!
 863                          * I take it to mean that it's syslogd's job
 864                          * to make those look identical in the log files. */
 865                         if (recvbuf[sz-1] != '\0' && recvbuf[sz-1] != '\n')
 866                                 break;
 867                         sz--;
 868                 }
 869 #if ENABLE_FEATURE_SYSLOGD_DUP
 870                 if ((option_mask32 & OPT_dup) && (sz == last_sz))
 871                         if (memcmp(last_buf, recvbuf, sz) == 0)
 872                                 continue;
 873                 last_sz = sz;
 874 #endif
 875 #if ENABLE_FEATURE_REMOTE_LOG
 876                 /* Stock syslogd sends it '\n'-terminated
 877                  * over network, mimic that */
 878                 recvbuf[sz] = '\n';
 879
 880                 /* We are not modifying log messages in any way before send */
 881                 /* Remote site cannot trust _us_ anyway and need to do validation again */
 882                 for (item = G.remoteHosts; item != NULL; item = item->link) {
 883                         remoteHost_t *rh = (remoteHost_t *)item->data;
 884
 885                         if (rh->remoteFD == -1) {
 886                                 rh->remoteFD = try_to_resolve_remote(rh);
 887                                 if (rh->remoteFD == -1)
 888                                         continue;
 889                         }
 890
 891                         /* Send message to remote logger.
 892                          * On some errors, close and set remoteFD to -1
 893                          * so that DNS resolution is retried.
 894                          */
 895                         if (sendto(rh->remoteFD, recvbuf, sz+1,
 896                                         MSG_DONTWAIT | MSG_NOSIGNAL,
 897                                         &(rh->remoteAddr->u.sa), rh->remoteAddr->len) == -1
 898                         ) {
 899                                 switch (errno) {
 900                                 case ECONNRESET:
 901                                 case ENOTCONN: /* paranoia */
 902                                 case EPIPE:
 903                                         close(rh->remoteFD);
 904                                         rh->remoteFD = -1;
 905                                         free(rh->remoteAddr);
 906                                         rh->remoteAddr = NULL;
 907                                 }
 908                         }
 909                 }
 910 #endif
 911                 if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) {
 912                         recvbuf[sz] = '\0'; /* ensure it *is* NUL terminated */
 913                         split_escape_and_log(recvbuf, sz);
 914                 }
 915         } /* while (!bb_got_signal) */
 916
 917         timestamp_and_log_internal("syslogd exiting");
 918         puts("syslogd exiting");
 919         remove_pidfile(CONFIG_PID_FILE_PATH "/syslogd.pid");
 920         if (ENABLE_FEATURE_IPC_SYSLOG)
 921                 ipcsyslog_cleanup();
 922         kill_myself_with_sig(bb_got_signal);
 923 #undef recvbuf
 924 }
 925
 926 int syslogd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 927 int syslogd_main(int argc UNUSED_PARAM, char **argv)
 928 {
 929         int opts;
 930         char OPTION_DECL;
 931 #if ENABLE_FEATURE_REMOTE_LOG
 932         llist_t *remoteAddrList = NULL;
 933 #endif
 934
 935         INIT_G();
 936
 937         /* No non-option params, -R can occur multiple times */
 938         opt_complementary = "=0" IF_FEATURE_REMOTE_LOG(":R::");
 939         opts = getopt32(argv, OPTION_STR, OPTION_PARAM);
 940 #if ENABLE_FEATURE_REMOTE_LOG
 941         while (remoteAddrList) {
 942                 remoteHost_t *rh = xzalloc(sizeof(*rh));
 943                 rh->remoteHostname = llist_pop(&remoteAddrList);
 944                 rh->remoteFD = -1;
 945                 rh->last_dns_resolve = monotonic_sec() - DNS_WAIT_SEC - 1;
 946                 llist_add_to(&G.remoteHosts, rh);
 947         }
 948 #endif
 949
 950 #ifdef SYSLOGD_MARK
 951         if (opts & OPT_mark) // -m
 952                 G.markInterval = xatou_range(opt_m, 0, INT_MAX/60) * 60;
 953 #endif
 954         //if (opts & OPT_nofork) // -n
 955         //if (opts & OPT_outfile) // -O
 956         if (opts & OPT_loglevel) // -l
 957                 G.logLevel = xatou_range(opt_l, 1, 8);
 958         //if (opts & OPT_small) // -S
 959 #if ENABLE_FEATURE_ROTATE_LOGFILE
 960         if (opts & OPT_filesize) // -s
 961                 G.logFileSize = xatou_range(opt_s, 0, INT_MAX/1024) * 1024;
 962         if (opts & OPT_rotatecnt) // -b
 963                 G.logFileRotate = xatou_range(opt_b, 0, 99);
 964 #endif
 965 #if ENABLE_FEATURE_IPC_SYSLOG
 966         if (opt_C) // -Cn
 967                 G.shm_size = xatoul_range(opt_C, 4, INT_MAX/1024) * 1024;
 968 #endif
 969         /* If they have not specified remote logging, then log locally */
 970         if (ENABLE_FEATURE_REMOTE_LOG && !(opts & OPT_remotelog)) // -R
 971                 option_mask32 |= OPT_locallog;
 972 #if ENABLE_FEATURE_SYSLOGD_CFG
 973         parse_syslogdcfg(opt_f);
 974 #endif
 975
 976         /* Store away localhost's name before the fork */
 977         G.hostname = safe_gethostname();
 978         *strchrnul(G.hostname, '.') = '\0';
 979
 980         if (!(opts & OPT_nofork)) {
 981                 bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
 982         }
 983
 984         //umask(0); - why??
 985         write_pidfile(CONFIG_PID_FILE_PATH "/syslogd.pid");
 986
 987         do_syslogd();
 988         /* return EXIT_SUCCESS; */
 989 }
 990
 991 /* Clean up. Needed because we are included from syslogd_and_logger.c */
 992 #undef DEBUG
 993 #undef SYSLOGD_MARK
 994 #undef SYSLOGD_WRLOCK
 995 #undef G
 996 #undef GLOBALS
 997 #undef INIT_G
 998 #undef OPTION_STR
 999 #undef OPTION_DECL
1000 #undef OPTION_PARAM