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