lash: make -c work; crush buffer overrun and free of non-malloced ptr
[oweals/busybox.git] / sysklogd / syslogd.c
index 0be9ded06cac9c589efb2ffb182867b5fd2b97b3..76a446b6a8f7770fb9c4163dddcbfe71bc5852bb 100644 (file)
+/* vi: set sw=4 ts=4: */
 /*
  * Mini syslogd implementation for busybox
  *
- * Copyright (C) 1999 by Lineo, inc.
- * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.org>
  *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
+ * "circular buffer" Copyright (C) 2001 by Gennady Feldman <gfeldman@gena01.com>
  *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Maintainer: Gennady Feldman <gfeldman@gena01.com> as of Mar 12, 2001
  *
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  */
 
-#include "internal.h"
-#include <stdio.h>
-#include <stdarg.h>
-#include <sys/socket.h>
-#include <sys/un.h>
-#include <unistd.h>
-#include <time.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <ctype.h>
-#include <netdb.h>
-#include <sys/klog.h>
-#include <errno.h>
+#include "busybox.h"
 #include <paths.h>
+#include <sys/un.h>
 
-#define ksyslog klogctl
-extern int ksyslog(int type, char *buf, int len);
-
+/* SYSLOG_NAMES defined to pull some extra junk from syslog.h: */
+/* prioritynames[] and facilitynames[]. uclibc pulls those in _rwdata_! :( */
 
-/* SYSLOG_NAMES defined to pull some extra junk from syslog.h */
 #define SYSLOG_NAMES
 #include <sys/syslog.h>
+#include <sys/uio.h>
 
-/* Path for the file where all log messages are written */
-#define __LOG_FILE             "/var/log/messages"
-
-
-static char* logFilePath = __LOG_FILE;
-/* interval between marks in seconds */
-static int MarkInterval = 20*60;
-/* localhost's name */
-static char LocalHostName[32];
-
-static const char syslogd_usage[] =
-    "syslogd [OPTION]...\n\n"
-    "Linux system and kernel (provides klogd) logging utility.\n"
-    "Note that this version of syslogd/klogd ignores /etc/syslog.conf.\n\n"
-    "Options:\n"
-    "\t-m\tChange the mark timestamp interval. default=20min. 0=off\n"
-    "\t-n\tDo not fork into the background (for when run by init)\n"
-#ifdef BB_KLOGD
-    "\t-K\tDo not start up the klogd process (by default syslogd spawns klogd).\n"
+#if ENABLE_FEATURE_REMOTE_LOG
+#include <netinet/in.h>
+#endif
+
+#if ENABLE_FEATURE_IPC_SYSLOG
+#include <sys/ipc.h>
+#include <sys/sem.h>
+#include <sys/shm.h>
+#endif
+
+
+#define DEBUG 0
+
+/* MARK code is not very useful, is bloat, and broken:
+ * can deadlock if alarmed to make MARK while writing to IPC buffer
+ * (semaphores are down but do_mark routine tries to down them again) */
+#undef SYSLOGD_MARK
+
+enum { MAX_READ = 256 };
+
+/* Semaphore operation structures */
+struct shbuf_ds {
+       int32_t size;   /* size of data written */
+       int32_t head;   /* start of message list */
+       int32_t tail;   /* end of message list */
+       char data[1];   /* data/messages */
+};
+
+/* Allows us to have smaller initializer. Ugly. */
+#define GLOBALS \
+       const char *logFilePath;                \
+       int logFD;                              \
+       /* interval between marks in seconds */ \
+       /*int markInterval;*/                   \
+       /* level of messages to be logged */    \
+       int logLevel;                           \
+USE_FEATURE_ROTATE_LOGFILE( \
+       /* max size of file before rotation */  \
+       unsigned logFileSize;                   \
+       /* number of rotated message files */   \
+       unsigned logFileRotate;                 \
+       unsigned curFileSize;                   \
+       smallint isRegular;                     \
+) \
+USE_FEATURE_REMOTE_LOG( \
+       /* udp socket for remote logging */     \
+       int remoteFD;                           \
+       len_and_sockaddr* remoteAddr;           \
+) \
+USE_FEATURE_IPC_SYSLOG( \
+       int shmid; /* ipc shared memory id */   \
+       int s_semid; /* ipc semaphore id */     \
+       int shm_size;                           \
+       struct sembuf SMwup[1];                 \
+       struct sembuf SMwdn[3];                 \
+)
+
+struct init_globals {
+       GLOBALS
+};
+
+struct globals {
+       GLOBALS
+#if ENABLE_FEATURE_IPC_SYSLOG
+       struct shbuf_ds *shbuf;
+#endif
+       time_t last_log_time;
+       /* localhost's name */
+       char localHostName[64];
+
+       /* We recv into recvbuf... */
+       char recvbuf[MAX_READ];
+       /* ...then copy to parsebuf, escaping control chars */
+       /* (can grow x2 max) */
+       char parsebuf[MAX_READ*2];
+       /* ...then sprintf into printbuf, adding timestamp (15 chars),
+        * host (64), fac.prio (20) to the message */
+       /* (growth by: 15 + 64 + 20 + delims = ~110) */
+       char printbuf[MAX_READ*2 + 128];
+};
+
+static const struct init_globals init_data = {
+       .logFilePath = "/var/log/messages",
+       .logFD = -1,
+#ifdef SYSLOGD_MARK
+       .markInterval = 20 * 60,
+#endif
+       .logLevel = 8,
+#if ENABLE_FEATURE_ROTATE_LOGFILE
+       .logFileSize = 200 * 1024,
+       .logFileRotate = 1,
+#endif
+#if ENABLE_FEATURE_REMOTE_LOG
+       .remoteFD = -1,
+#endif
+#if ENABLE_FEATURE_IPC_SYSLOG
+       .shmid = -1,
+       .s_semid = -1,
+       .shm_size = ((CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE)*1024), // default shm size
+       .SMwup = { {1, -1, IPC_NOWAIT} },
+       .SMwdn = { {0, 0}, {1, 0}, {1, +1} },
+#endif
+};
+
+#define G (*ptr_to_globals)
+
+
+/* Options */
+enum {
+       OPTBIT_mark = 0, // -m
+       OPTBIT_nofork, // -n
+       OPTBIT_outfile, // -O
+       OPTBIT_loglevel, // -l
+       OPTBIT_small, // -S
+       USE_FEATURE_ROTATE_LOGFILE(OPTBIT_filesize   ,) // -s
+       USE_FEATURE_ROTATE_LOGFILE(OPTBIT_rotatecnt  ,) // -b
+       USE_FEATURE_REMOTE_LOG(    OPTBIT_remote     ,) // -R
+       USE_FEATURE_REMOTE_LOG(    OPTBIT_localtoo   ,) // -L
+       USE_FEATURE_IPC_SYSLOG(    OPTBIT_circularlog,) // -C
+
+       OPT_mark        = 1 << OPTBIT_mark    ,
+       OPT_nofork      = 1 << OPTBIT_nofork  ,
+       OPT_outfile     = 1 << OPTBIT_outfile ,
+       OPT_loglevel    = 1 << OPTBIT_loglevel,
+       OPT_small       = 1 << OPTBIT_small   ,
+       OPT_filesize    = USE_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_filesize   )) + 0,
+       OPT_rotatecnt   = USE_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_rotatecnt  )) + 0,
+       OPT_remotelog   = USE_FEATURE_REMOTE_LOG(    (1 << OPTBIT_remote     )) + 0,
+       OPT_locallog    = USE_FEATURE_REMOTE_LOG(    (1 << OPTBIT_localtoo   )) + 0,
+       OPT_circularlog = USE_FEATURE_IPC_SYSLOG(    (1 << OPTBIT_circularlog)) + 0,
+};
+#define OPTION_STR "m:nO:l:S" \
+       USE_FEATURE_ROTATE_LOGFILE("s:" ) \
+       USE_FEATURE_ROTATE_LOGFILE("b:" ) \
+       USE_FEATURE_REMOTE_LOG(    "R:" ) \
+       USE_FEATURE_REMOTE_LOG(    "L"  ) \
+       USE_FEATURE_IPC_SYSLOG(    "C::")
+#define OPTION_DECL *opt_m, *opt_l \
+       USE_FEATURE_ROTATE_LOGFILE(,*opt_s) \
+       USE_FEATURE_ROTATE_LOGFILE(,*opt_b) \
+       USE_FEATURE_REMOTE_LOG(    ,*opt_R) \
+       USE_FEATURE_IPC_SYSLOG(    ,*opt_C = NULL)
+#define OPTION_PARAM &opt_m, &G.logFilePath, &opt_l \
+       USE_FEATURE_ROTATE_LOGFILE(,&opt_s) \
+       USE_FEATURE_ROTATE_LOGFILE(,&opt_b) \
+       USE_FEATURE_REMOTE_LOG(    ,&opt_R) \
+       USE_FEATURE_IPC_SYSLOG(    ,&opt_C)
+
+
+/* circular buffer variables/structures */
+#if ENABLE_FEATURE_IPC_SYSLOG
+
+#if CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE < 4
+#error Sorry, you must set the syslogd buffer size to at least 4KB.
+#error Please check CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE
 #endif
-    "\t-O\tSpecify an alternate log file.  default=/var/log/messages\n";
 
+/* our shared key */
+#define KEY_ID ((long)0x414e4547) /* "GENA" */
 
-/* try to open up the specified device */
-static int device_open(char *device, int mode)
+static void ipcsyslog_cleanup(void)
 {
-    int m, f, fd = -1;
-
-    m = mode | O_NONBLOCK;
-
-    /* Retry up to 5 times */
-    for (f = 0; f < 5; f++)
-       if ((fd = open(device, m)) >= 0)
-           break;
-    if (fd < 0)
-       return fd;
-    /* Reset original flags. */
-    if (m != mode)
-       fcntl(fd, F_SETFL, mode);
-    return fd;
+       if (G.shmid != -1) {
+               shmdt(G.shbuf);
+       }
+       if (G.shmid != -1) {
+               shmctl(G.shmid, IPC_RMID, NULL);
+       }
+       if (G.s_semid != -1) {
+               semctl(G.s_semid, 0, IPC_RMID, 0);
+       }
 }
 
-/* print a message to the log file */
-static void message(char *fmt, ...)
+static void ipcsyslog_init(void)
 {
-    int fd;
-    va_list arguments;
-
-    if ((fd = device_open(logFilePath, O_WRONLY|O_CREAT|O_NOCTTY|O_APPEND|O_NONBLOCK)) >= 0) {
-       va_start(arguments, fmt);
-       vdprintf(fd, fmt, arguments);
-       va_end(arguments);
-       close(fd);
-    } else {
-       /* Always send console messages to /dev/console so people will see them. */
-       if ((fd = device_open(_PATH_CONSOLE, O_WRONLY|O_NOCTTY|O_NONBLOCK)) >= 0) {
-           va_start(arguments, fmt);
-           vdprintf(fd, fmt, arguments);
-           va_end(arguments);
-           close(fd);
-       } else {
-           fprintf(stderr, "Bummer, can't print: ");
-           va_start(arguments, fmt);
-           vfprintf(stderr, fmt, arguments);
-           fflush(stderr);
-           va_end(arguments);
+       if (DEBUG)
+               printf("shmget(%lx, %d,...)\n", KEY_ID, G.shm_size);
+
+       G.shmid = shmget(KEY_ID, G.shm_size, IPC_CREAT | 1023);
+       if (G.shmid == -1) {
+               bb_perror_msg_and_die("shmget");
+       }
+
+       G.shbuf = shmat(G.shmid, NULL, 0);
+       if (!G.shbuf) {
+               bb_perror_msg_and_die("shmat");
+       }
+
+       G.shbuf->size = G.shm_size - offsetof(struct shbuf_ds, data);
+       G.shbuf->head = G.shbuf->tail = 0;
+
+       // we'll trust the OS to set initial semval to 0 (let's hope)
+       G.s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023);
+       if (G.s_semid == -1) {
+               if (errno == EEXIST) {
+                       G.s_semid = semget(KEY_ID, 2, 0);
+                       if (G.s_semid != -1)
+                               return;
+               }
+               bb_perror_msg_and_die("semget");
        }
-    }
 }
 
-static void logMessage( int pri, char* msg) 
+/* Write message to shared mem buffer */
+static void log_to_shmem(const char *msg, int len)
 {
-    time_t  now;
-    char *timestamp;
-    static char res[20];
-    CODE *c_pri, *c_fac;
-
-    for (c_fac=facilitynames; c_fac->c_name && !(c_fac->c_val==LOG_FAC(pri)<<3); c_fac++);
-    for (c_pri=prioritynames; c_pri->c_name && !(c_pri->c_val==LOG_PRI(pri)); c_pri++);
-    if (*c_fac->c_name=='\0' || *c_pri->c_name=='\0')
-       snprintf (res, sizeof(res), "<%d>", pri);
-    else
-       snprintf (res, sizeof(res), "%s.%s", c_fac->c_name, c_pri->c_name);
-
-    if (strlen(msg) < 16 || msg[3] != ' ' || msg[6] != ' ' || 
-           msg[9] != ':' || msg[12] != ':' || msg[15] != ' ') 
-    {
-       time(&now);
-       timestamp = ctime(&now) + 4;
-       timestamp[15] = '\0';
-    } else {
-       timestamp = msg;
-       timestamp[15] = '\0';
-       msg += 16;
-    }
+       int old_tail, new_tail;
+       char *c;
 
-    /* todo: supress duplicates */
+       if (semop(G.s_semid, G.SMwdn, 3) == -1) {
+               bb_perror_msg_and_die("SMwdn");
+       }
 
-    /* now spew out the message to wherever it is supposed to go */
-    message( "%s %s %s %s\n", timestamp, LocalHostName, res, msg);
+       /* Circular Buffer Algorithm:
+        * --------------------------
+        * tail == position where to store next syslog message.
+        * head == position of next message to retrieve ("print").
+        * if head == tail, there is no "unprinted" messages left.
+        * head is typically advanced by separate "reader" program,
+        * but if there isn't one, we have to do it ourself.
+        * messages are NUL-separated.
+        */
+       len++; /* length with NUL included */
+ again:
+       old_tail = G.shbuf->tail;
+       new_tail = old_tail + len;
+       if (new_tail < G.shbuf->size) {
+               /* No need to move head if shbuf->head <= old_tail,
+                * else... */
+               if (old_tail < G.shbuf->head && G.shbuf->head <= new_tail) {
+                       /* ...need to move head forward */
+                       c = memchr(G.shbuf->data + new_tail, '\0',
+                                          G.shbuf->size - new_tail);
+                       if (!c) /* no NUL ahead of us, wrap around */
+                               c = memchr(G.shbuf->data, '\0', old_tail);
+                       if (!c) { /* still nothing? point to this msg... */
+                               G.shbuf->head = old_tail;
+                       } else {
+                               /* convert pointer to offset + skip NUL */
+                               G.shbuf->head = c - G.shbuf->data + 1;
+                       }
+               }
+               /* store message, set new tail */
+               memcpy(G.shbuf->data + old_tail, msg, len);
+               G.shbuf->tail = new_tail;
+       } else {
+               /* we need to break up the message and wrap it around */
+               /* k == available buffer space ahead of old tail */
+               int k = G.shbuf->size - old_tail - 1;
+               if (G.shbuf->head > old_tail) {
+                       /* we are going to overwrite head, need to
+                        * move it out of the way */
+                       c = memchr(G.shbuf->data, '\0', old_tail);
+                       if (!c) { /* nothing? point to this msg... */
+                               G.shbuf->head = old_tail;
+                       } else { /* convert pointer to offset + skip NUL */
+                               G.shbuf->head = c - G.shbuf->data + 1;
+                       }
+               }
+               /* copy what fits to the end of buffer, and repeat */
+               memcpy(G.shbuf->data + old_tail, msg, k);
+               msg += k;
+               len -= k;
+               G.shbuf->tail = 0;
+               goto again;
+       }
+       if (semop(G.s_semid, G.SMwup, 1) == -1) {
+               bb_perror_msg_and_die("SMwup");
+       }
+       if (DEBUG)
+               printf("head:%d tail:%d\n", G.shbuf->head, G.shbuf->tail);
 }
+#else
+void ipcsyslog_cleanup(void);
+void ipcsyslog_init(void);
+void log_to_shmem(const char *msg);
+#endif /* FEATURE_IPC_SYSLOG */
 
-static void quit_signal(int sig)
+
+/* Print a message to the log file. */
+static void log_locally(char *msg)
 {
-    logMessage(LOG_SYSLOG|LOG_INFO, "System log daemon exiting.");
-    unlink( _PATH_LOG);
-    exit( TRUE);
+       struct flock fl;
+       int len = strlen(msg);
+
+#if ENABLE_FEATURE_IPC_SYSLOG
+       if ((option_mask32 & OPT_circularlog) && G.shbuf) {
+               log_to_shmem(msg, len);
+               return;
+       }
+#endif
+       if (G.logFD >= 0) {
+               time_t cur;
+               time(&cur);
+               if (G.last_log_time != cur) {
+                       G.last_log_time = cur; /* reopen log file every second */
+                       close(G.logFD);
+                       goto reopen;
+               }
+       } else {
+ reopen:
+               G.logFD = device_open(G.logFilePath, O_WRONLY | O_CREAT
+                                       | O_NOCTTY | O_APPEND | O_NONBLOCK);
+               if (G.logFD < 0) {
+                       /* cannot open logfile? - print to /dev/console then */
+                       int fd = device_open(_PATH_CONSOLE, O_WRONLY | O_NOCTTY | O_NONBLOCK);
+                       if (fd < 0)
+                               fd = 2; /* then stderr, dammit */
+                       full_write(fd, msg, len);
+                       if (fd != 2)
+                               close(fd);
+                       return;
+               }
+#if ENABLE_FEATURE_ROTATE_LOGFILE
+               {
+               struct stat statf;
+
+               G.isRegular = (fstat(G.logFD, &statf) == 0 && (statf.st_mode & S_IFREG));
+               /* bug (mostly harmless): can wrap around if file > 4gb */
+               G.curFileSize = statf.st_size;
+               }
+#endif
+       }
+
+       fl.l_whence = SEEK_SET;
+       fl.l_start = 0;
+       fl.l_len = 1;
+       fl.l_type = F_WRLCK;
+       fcntl(G.logFD, F_SETLKW, &fl);
+
+#if ENABLE_FEATURE_ROTATE_LOGFILE
+       if (G.logFileSize && G.isRegular && G.curFileSize > G.logFileSize) {
+               if (G.logFileRotate) { /* always 0..99 */
+                       int i = strlen(G.logFilePath) + 3 + 1;
+                       char oldFile[i];
+                       char newFile[i];
+                       i = G.logFileRotate - 1;
+                       /* rename: f.8 -> f.9; f.7 -> f.8; ... */
+                       while (1) {
+                               sprintf(newFile, "%s.%d", G.logFilePath, i);
+                               if (i == 0) break;
+                               sprintf(oldFile, "%s.%d", G.logFilePath, --i);
+                               rename(oldFile, newFile);
+                       }
+                       /* newFile == "f.0" now */
+                       rename(G.logFilePath, newFile);
+                       fl.l_type = F_UNLCK;
+                       fcntl(G.logFD, F_SETLKW, &fl);
+                       close(G.logFD);
+                       goto reopen;
+               }
+               ftruncate(G.logFD, 0);
+       }
+       G.curFileSize +=
+#endif
+                       full_write(G.logFD, msg, len);
+       fl.l_type = F_UNLCK;
+       fcntl(G.logFD, F_SETLKW, &fl);
 }
 
-static void restart_signal(int sig)
+static void parse_fac_prio_20(int pri, char *res20)
 {
-    /* pretend to restart */
-    logMessage(LOG_SYSLOG|LOG_INFO, "syslogd restarting");
+       CODE *c_pri, *c_fac;
+
+       if (pri != 0) {
+               c_fac = facilitynames;
+               while (c_fac->c_name) {
+                       if (c_fac->c_val != (LOG_FAC(pri) << 3)) {
+                               c_fac++; continue;
+                       }
+                       /* facility is found, look for prio */
+                       c_pri = prioritynames;
+                       while (c_pri->c_name) {
+                               if (c_pri->c_val != LOG_PRI(pri)) {
+                                       c_pri++; continue;
+                               }
+                               snprintf(res20, 20, "%s.%s",
+                                               c_fac->c_name, c_pri->c_name);
+                               return;
+                       }
+                       /* prio not found, bail out */
+                       break;
+               }
+               snprintf(res20, 20, "<%d>", pri);
+       }
 }
 
-static void domark(int sig)
+/* len parameter is used only for "is there a timestamp?" check.
+ * NB: some callers cheat and supply 0 when they know
+ * that there is no timestamp, short-cutting the test. */
+static void timestamp_and_log(int pri, char *msg, int len)
 {
-    if (MarkInterval > 0) {
-       logMessage(LOG_SYSLOG|LOG_INFO, "-- MARK --");
-       alarm(MarkInterval);
-    }
+       char *timestamp;
+
+       if (len < 16 || msg[3] != ' ' || msg[6] != ' '
+        || msg[9] != ':' || msg[12] != ':' || msg[15] != ' '
+       ) {
+               time_t now;
+               time(&now);
+               timestamp = ctime(&now) + 4;
+       } else {
+               timestamp = msg;
+               msg += 16;
+       }
+       timestamp[15] = '\0';
+
+       /* Log message locally (to file or shared mem) */
+       if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) {
+               if (LOG_PRI(pri) < G.logLevel) {
+                       if (option_mask32 & OPT_small)
+                               sprintf(G.printbuf, "%s %s\n", timestamp, msg);
+                       else {
+                               char res[20];
+                               parse_fac_prio_20(pri, res);
+                               sprintf(G.printbuf, "%s %s %s %s\n", timestamp, G.localHostName, res, msg);
+                       }
+                       log_locally(G.printbuf);
+               }
+       }
 }
 
-static void doSyslogd(void)
+static void split_escape_and_log(char *tmpbuf, int len)
 {
-    struct sockaddr_un sunx;
-    int fd, conn;
-    size_t addrLength;
-    char buf[1024];
-    char *q, *p = buf;
-    int readSize;
-
-    /* Remove any preexisting socket/file */
-    unlink(_PATH_LOG);
-
-    /* Set up sig handlers */
-    signal(SIGINT,  quit_signal);
-    signal(SIGTERM, quit_signal);
-    signal(SIGQUIT, quit_signal);
-    signal(SIGHUP,  restart_signal);
-    signal(SIGALRM, domark);
-    alarm(MarkInterval);
-
-
-    unlink( _PATH_LOG);
-    memset(&sunx, 0, sizeof(sunx));
-    sunx.sun_family = AF_UNIX; /* Unix domain socket */
-    strncpy(sunx.sun_path, _PATH_LOG, sizeof(sunx.sun_path));
-    if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0 ) {
-        perror("Couldn't obtain descriptor for socket " _PATH_LOG);
-       exit( FALSE);
-    }
-
-    addrLength = sizeof(sunx.sun_family) + strlen(sunx.sun_path);
-    if ( (bind(fd, (struct sockaddr *) &sunx, addrLength)) ||
-           (fchmod(fd, 0666) < 0) || (listen(fd, 5)) ) 
-    {
-       perror("Could not connect to socket " _PATH_LOG);
-       exit( FALSE);
-    }
-    
-    
-    logMessage(LOG_SYSLOG|LOG_INFO, "syslogd started: "
-           "BusyBox v" BB_VER " (" BB_BT ")");
-
-
-    while ((conn = accept(fd, (struct sockaddr *) &sunx, 
-                          &addrLength)) >= 0) 
-    {
-       while ((readSize=read(conn, buf, sizeof(buf))) > 0)
-       {
-           char line[1025];
-           unsigned char c;
-           int pri = (LOG_USER|LOG_NOTICE);
-
-           memset (line, 0, sizeof(line));
-           p = buf;
-           q = line;
-           while ( p && (c = *p) && q < &line[sizeof(line) - 1]) {
-               if (c == '<') {
-                   /* Parse the magic priority number */
-                   pri = 0;
-                   while (isdigit(*(++p))) {
-                       pri = 10 * pri + (*p - '0');
-                   }
-                   if (pri &~ (LOG_FACMASK|LOG_PRIMASK))
-                       pri = (LOG_USER|LOG_NOTICE);
-               } else if (c == '\n') {
-                   *q++ = ' ';
-               } else if (iscntrl(c)&&(c<0177)) {
-                   *q++ = '^';
-                   *q++ = c ^ 0100;
-               } else {
-                   *q++ = c;
+       char *p = tmpbuf;
+
+       tmpbuf += len;
+       while (p < tmpbuf) {
+               char c;
+               char *q = G.parsebuf;
+               int pri = (LOG_USER | LOG_NOTICE);
+
+               if (*p == '<') {
+                       /* Parse the magic priority number */
+                       pri = bb_strtou(p + 1, &p, 10);
+                       if (*p == '>') p++;
+                       if (pri & ~(LOG_FACMASK | LOG_PRIMASK)) {
+                               pri = (LOG_USER | LOG_NOTICE);
+                       }
                }
-               p++;
-           }
-           *q = '\0';
 
-           /* Now log it */
-           logMessage( pri, line);
+               while ((c = *p++)) {
+                       if (c == '\n')
+                               c = ' ';
+                       if (!(c & ~0x1f)) {
+                               *q++ = '^';
+                               c += '@'; /* ^@, ^A, ^B... */
+                       }
+                       *q++ = c;
+               }
+               *q = '\0';
+               /* Now log it */
+               timestamp_and_log(pri, G.parsebuf, q - G.parsebuf);
        }
-        close(conn);
-    }
-
-    close(fd);
 }
 
-#ifdef BB_KLOGD
-
-static void klogd_signal(int sig)
+static void quit_signal(int sig)
 {
-    ksyslog(7, NULL, 0);
-    ksyslog(0, 0, 0);
-    logMessage(LOG_SYSLOG|LOG_INFO, "Kernel log daemon exiting.");
-    exit( TRUE);
+       timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)"syslogd exiting", 0);
+       puts("syslogd exiting");
+       if (ENABLE_FEATURE_IPC_SYSLOG)
+               ipcsyslog_cleanup();
+       exit(1);
 }
 
-static void doKlogd(void)
+#ifdef SYSLOGD_MARK
+static void do_mark(int sig)
 {
-    int priority=LOG_INFO;
-    char log_buffer[4096];
-    char *logp;
-
-    /* Set up sig handlers */
-    signal(SIGINT,  klogd_signal);
-    signal(SIGKILL, klogd_signal);
-    signal(SIGTERM, klogd_signal);
-    signal(SIGHUP,  klogd_signal);
-    logMessage(LOG_SYSLOG|LOG_INFO, "klogd started: "
-           "BusyBox v" BB_VER " (" BB_BT ")");
-
-    ksyslog(1, NULL, 0);
-
-    while (1) {
-       /* Use kernel syscalls */
-       memset(log_buffer, '\0', sizeof(log_buffer));
-       if ( ksyslog(2, log_buffer, sizeof(log_buffer)) < 0 ) {
-           char message[80];
-           if ( errno == EINTR )
-               continue;
-           snprintf(message, 79, "klogd: Error return from sys_sycall: " \
-                   "%d - %s.\n", errno, strerror(errno));
-           logMessage(LOG_SYSLOG|LOG_ERR, message);
-           exit(1);
+       if (G.markInterval) {
+               timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)"-- MARK --", 0);
+               alarm(G.markInterval);
        }
-       logp=log_buffer;
-        if ( *log_buffer == '<' )
-        {
-           switch ( *(log_buffer+1) )
-           {
-               case '0':
-                   priority = LOG_EMERG;
-                   break;
-               case '1':
-                   priority = LOG_ALERT;
-                   break;
-               case '2':
-                   priority = LOG_CRIT;
-                   break;
-               case '3':
-                   priority = LOG_ERR;
-                   break;
-               case '4':
-                   priority = LOG_WARNING;
-                   break;
-               case '5':
-                   priority = LOG_NOTICE;
-                   break;
-               case '6':
-                   priority = LOG_INFO;
-                   break;
-               case '7':
-               default:
-                   priority = LOG_DEBUG;
-           }
-           logp+=3;
-        }
-       logMessage(LOG_KERN|priority, logp);
-    }
-
 }
-
 #endif
 
-extern int syslogd_main(int argc, char **argv)
+static void do_syslogd(void) ATTRIBUTE_NORETURN;
+static void do_syslogd(void)
 {
-    int        pid, klogd_pid;
-    int doFork = TRUE;
-#ifdef BB_KLOGD
-    int startKlogd = TRUE;
+       struct sockaddr_un sunx;
+       int sock_fd;
+       fd_set fds;
+       char *dev_log_name;
+
+       /* Set up signal handlers */
+       signal(SIGINT, quit_signal);
+       signal(SIGTERM, quit_signal);
+       signal(SIGQUIT, quit_signal);
+       signal(SIGHUP, SIG_IGN);
+       signal(SIGCHLD, SIG_IGN);
+#ifdef SIGCLD
+       signal(SIGCLD, SIG_IGN);
 #endif
-    int stopDoingThat = FALSE;
-    char *p;
-    char **argv1=argv;
-    
-    while (--argc > 0 && **(++argv1) == '-') {
-       stopDoingThat = FALSE;
-       while (stopDoingThat == FALSE && *(++(*argv1))) {
-           switch (**argv1) {
-           case 'm':
-               if (--argc == 0) {
-                   usage(syslogd_usage);
-               }
-               MarkInterval = atoi(*(++argv1))*60;
-               break;
-           case 'n':
-               doFork = FALSE;
-               break;
-#ifdef BB_KLOGD
-           case 'K':
-               startKlogd = FALSE;
-               break;
+#ifdef SYSLOGD_MARK
+       signal(SIGALRM, do_mark);
+       alarm(G.markInterval);
 #endif
-           case 'O':
-               if (--argc == 0) {
-                   usage(syslogd_usage);
-               }
-               logFilePath = *(++argv1);
-               stopDoingThat = TRUE;
-               break;
-           default:
-               usage(syslogd_usage);
-           }
+       remove_pidfile("/var/run/syslogd.pid");
+
+       memset(&sunx, 0, sizeof(sunx));
+       sunx.sun_family = AF_UNIX;
+       strcpy(sunx.sun_path, "/dev/log");
+
+       /* Unlink old /dev/log or object it points to. */
+       /* (if it exists, bind will fail) */
+       logmode = LOGMODE_NONE;
+       dev_log_name = xmalloc_readlink_or_warn("/dev/log");
+       logmode = LOGMODE_STDIO;
+       if (dev_log_name) {
+               int fd = xopen(".", O_NONBLOCK);
+               xchdir("/dev");
+               /* we do not check whether this is a link also */
+               unlink(dev_log_name);
+               fchdir(fd);
+               close(fd);
+               safe_strncpy(sunx.sun_path, dev_log_name, sizeof(sunx.sun_path));
+               free(dev_log_name);
+       } else {
+               unlink("/dev/log");
        }
-    }
-    
-    /* Store away localhost's name before the fork */
-    gethostname(LocalHostName, sizeof(LocalHostName));
-    if ( (p = strchr(LocalHostName, '.')) ) {
-       *p++ = '\0';
-    }
-
-    if (doFork == TRUE) {
-       pid = fork();
-       if ( pid < 0 )
-           exit( pid);
-       else if ( pid == 0 ) {
-           strncpy(argv[0], "syslogd",strlen(argv[0]));
-           doSyslogd();
+
+       sock_fd = xsocket(AF_UNIX, SOCK_DGRAM, 0);
+       xbind(sock_fd, (struct sockaddr *) &sunx, sizeof(sunx));
+
+       if (chmod("/dev/log", 0666) < 0) {
+               bb_perror_msg_and_die("cannot set permission on /dev/log");
        }
-    } else {
-       doSyslogd();
-    }
-
-#ifdef BB_KLOGD
-    /* Start up the klogd process */
-    if (startKlogd == TRUE) {
-       klogd_pid = fork();
-       if (klogd_pid == 0 ) {
-               strncpy(argv[0], "klogd", strlen(argv[0]));
-               doKlogd();
+       if (ENABLE_FEATURE_IPC_SYSLOG && (option_mask32 & OPT_circularlog)) {
+               ipcsyslog_init();
        }
-    }
-#endif
 
-    exit( TRUE);
+       timestamp_and_log(LOG_SYSLOG | LOG_INFO,
+                       (char*)"syslogd started: BusyBox v" BB_VER, 0);
+
+       for (;;) {
+               FD_ZERO(&fds);
+               FD_SET(sock_fd, &fds);
+
+               if (select(sock_fd + 1, &fds, NULL, NULL, NULL) < 0) {
+                       if (errno == EINTR) {
+                               /* alarm may have happened */
+                               continue;
+                       }
+                       bb_perror_msg_and_die("select");
+               }
+
+               if (FD_ISSET(sock_fd, &fds)) {
+                       int i;
+                       i = recv(sock_fd, G.recvbuf, MAX_READ - 1, 0);
+                       if (i <= 0)
+                               bb_perror_msg_and_die("UNIX socket error");
+                       /* TODO: maybe suppress duplicates? */
+#if ENABLE_FEATURE_REMOTE_LOG
+                       /* We are not modifying log messages in any way before send */
+                       /* Remote site cannot trust _us_ anyway and need to do validation again */
+                       if (G.remoteAddr) {
+                               if (-1 == G.remoteFD) {
+                                       G.remoteFD = socket(G.remoteAddr->sa.sa_family, SOCK_DGRAM, 0);
+                               }
+                               if (-1 != G.remoteFD) {
+                                       /* send message to remote logger, ignore possible error */
+                                       sendto(G.remoteFD, G.recvbuf, i, MSG_DONTWAIT,
+                                               &G.remoteAddr->sa, G.remoteAddr->len);
+                               }
+                       }
+#endif
+                       G.recvbuf[i] = '\0';
+                       split_escape_and_log(G.recvbuf, i);
+               } /* FD_ISSET() */
+       } /* for */
 }
 
+int syslogd_main(int argc, char **argv);
+int syslogd_main(int argc, char **argv)
+{
+       char OPTION_DECL;
+       char *p;
 
+       PTR_TO_GLOBALS = memcpy(xzalloc(sizeof(G)), &init_data, sizeof(init_data));
+
+       /* do normal option parsing */
+       opt_complementary = "=0"; /* no non-option params */
+       getopt32(argc, argv, OPTION_STR, OPTION_PARAM);
+#ifdef SYSLOGD_MARK
+       if (option_mask32 & OPT_mark) // -m
+               G.markInterval = xatou_range(opt_m, 0, INT_MAX/60) * 60;
+#endif
+       //if (option_mask32 & OPT_nofork) // -n
+       //if (option_mask32 & OPT_outfile) // -O
+       if (option_mask32 & OPT_loglevel) // -l
+               G.logLevel = xatou_range(opt_l, 1, 8);
+       //if (option_mask32 & OPT_small) // -S
+#if ENABLE_FEATURE_ROTATE_LOGFILE
+       if (option_mask32 & OPT_filesize) // -s
+               G.logFileSize = xatou_range(opt_s, 0, INT_MAX/1024) * 1024;
+       if (option_mask32 & OPT_rotatecnt) // -b
+               G.logFileRotate = xatou_range(opt_b, 0, 99);
+#endif
+#if ENABLE_FEATURE_REMOTE_LOG
+       if (option_mask32 & OPT_remotelog) { // -R
+               G.remoteAddr = xhost2sockaddr(opt_R, 514);
+       }
+       //if (option_mask32 & OPT_locallog) // -L
+#endif
+#if ENABLE_FEATURE_IPC_SYSLOG
+       if (opt_C) // -Cn
+               G.shm_size = xatoul_range(opt_C, 4, INT_MAX/1024) * 1024;
+#endif
+
+       /* If they have not specified remote logging, then log locally */
+       if (ENABLE_FEATURE_REMOTE_LOG && !(option_mask32 & OPT_remotelog))
+               option_mask32 |= OPT_locallog;
+
+       /* Store away localhost's name before the fork */
+       gethostname(G.localHostName, sizeof(G.localHostName));
+       p = strchr(G.localHostName, '.');
+       if (p) {
+               *p = '\0';
+       }
+
+       if (!(option_mask32 & OPT_nofork)) {
+               bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
+       }
+       umask(0);
+       write_pidfile("/var/run/syslogd.pid");
+       do_syslogd();
+       /* return EXIT_SUCCESS; */
+}