syslogd: reduce data/bss usage. Code size is practically the same.
[oweals/busybox.git] / sysklogd / syslogd.c
index 8ae70a1eda4057d5e72d9c63541d76ffabcad3b5..8ae75c9743eb269adbffbe025b0c75d1de384574 100644 (file)
 /*
  * Mini syslogd implementation for busybox
  *
- * Copyright (C) 1999,2000,2001 by Lineo, inc.
- * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
  *
  * Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.org>
  *
- * "circular buffer" Copyright (C) 2001 by Gennady Feldman <gfeldman@cachier.com>
+ * "circular buffer" Copyright (C) 2001 by Gennady Feldman <gfeldman@gena01.com>
  *
- * Maintainer: Gennady Feldman <gena01@cachier.com> as of Mar 12, 2001
- *
- * 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.
- *
- * 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.
- *
- * 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 <stdio.h>
-#include <stdlib.h>
-#include <ctype.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <netdb.h>
+#include "busybox.h"
 #include <paths.h>
-#include <signal.h>
-#include <stdarg.h>
-#include <time.h>
-#include <string.h>
-#include <unistd.h>
-#include <sys/socket.h>
-#include <sys/types.h>
 #include <sys/un.h>
-#include <sys/param.h>
 
-#include "busybox.h"
+/* 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"
+#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
 
-/* Path to the unix socket */
-static char lfile[BUFSIZ];
 
-static char *logFilePath = __LOG_FILE;
+#define DEBUG 0
 
-/* interval between marks in seconds */
-static int MarkInterval = 20 * 60;
+// 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
+};                      // shared memory pointer
+
+struct globals {
+
+       const char *logFilePath;
+       int logFD;
+
+       /* This 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) */
+#ifdef SYSLOGD_MARK
+       /* interval between marks in seconds */
+       int markInterval;
+#endif
 
-/* localhost's name */
-static char LocalHostName[32];
+       /* level of messages to be locally logged */
+       int logLevel;
 
-#ifdef BB_FEATURE_REMOTE_LOG
-#include <netinet/in.h>
-/* udp socket for logging to remote host */
-static int remotefd = -1;
-/* where do we log? */
-static char *RemoteHost;
-/* what port to log to? */
-static int RemotePort = 514;
-/* To remote log or not to remote log, that is the question. */
-static int doRemoteLog = FALSE;
-static int local_logging = FALSE;
+#if ENABLE_FEATURE_ROTATE_LOGFILE
+       /* max size of message file before being rotated */
+       unsigned logFileSize;
+       /* number of rotated message files */
+       unsigned logFileRotate;
+       unsigned curFileSize;
+       smallint isRegular;
 #endif
 
-/* circular buffer variables/structures */
-#ifdef BB_FEATURE_IPC_SYSLOG
+#if ENABLE_FEATURE_REMOTE_LOG
+       /* udp socket for logging to remote host */
+       int remoteFD;
+       len_and_sockaddr* remoteAddr;
+#endif
 
-#include <sys/ipc.h>
-#include <sys/sem.h>
-#include <sys/shm.h>
+#if ENABLE_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 shbuf_ds *shbuf;
+#endif
 
-/* our shared key */
-static const long KEY_ID = 0x414e4547; /*"GENA"*/
+       time_t last_log_time;
+       /* localhost's name */
+       char localHostName[64];
 
-// Semaphore operation structures
-static struct shbuf_ds {
-       int size;               // size of data written
-       int head;               // start of message list
-       int tail;               // end of message list
-       char data[1];           // data/messages
-} *buf = NULL;                 // shared memory pointer
-
-static struct sembuf SMwup[1] = {{1, -1, IPC_NOWAIT}}; // set SMwup
-static struct sembuf SMwdn[3] = {{0, 0}, {1, 0}, {1, +1}}; // set SMwdn
-
-static int     shmid = -1;     // ipc shared memory id
-static int     s_semid = -1;   // ipc semaphore id
-int    data_size = 16000; // data size
-int    shm_size = 16000 + sizeof(*buf); // our buffer size
-static int circular_logging = FALSE;
+}; /* struct globals */
 
-/*
- * sem_up - up()'s a semaphore.
- */
-static inline void sem_up(int semid)
-{
-       if ( semop(semid, SMwup, 1) == -1 )
-               perror_msg_and_die("semop[SMwup]");
-}
+static const struct globals init_globals = {
+       .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
+       // FIXME: hidden tail with lotsa zeroes is here....
+};
+
+#define G (*ptr_to_globals)
+
+
+/* We are using bb_common_bufsiz1 for buffering: */
+enum { MAX_READ = (BUFSIZ/6) & ~0xf };
+/* We recv into RECVBUF... (size: MAX_READ ~== BUFSIZ/6) */
+#define RECVBUF  bb_common_bufsiz1
+/* ...then copy to PARSEBUF, escaping control chars */
+/* (can grow x2 max ~== BUFSIZ/3) */
+#define PARSEBUF (bb_common_bufsiz1 + MAX_READ)
+/* ...then sprintf into PRINTBUF, adding timestamp (15 chars),
+ * host (64), fac.prio (20) to the message */
+/* (growth by: 15 + 64 + 20 + delims = ~110) */
+#define PRINTBUF (bb_common_bufsiz1 + 3*MAX_READ)
+/* totals: BUFSIZ == BUFSIZ/6 + BUFSIZ/3 + (BUFSIZ/3+BUFSIZ/6)
+ * -- we have BUFSIZ/6 extra at the ent of PRINTBUF
+ * which covers needed ~110 extra bytes (and much more) */
+
+
+/* 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)
 
-/*
- * sem_down - down()'s a semaphore
- */
-static inline void sem_down(int semid)
-{
-       if ( semop(semid, SMwdn, 3) == -1 )
-               perror_msg_and_die("semop[SMwdn]");
-}
 
+/* circular buffer variables/structures */
+#if ENABLE_FEATURE_IPC_SYSLOG
 
-void ipcsyslog_cleanup(void){
-       printf("Exiting Syslogd!\n");
-       if (shmid != -1)
-               shmdt(buf);
+#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
 
-       if (shmid != -1)
-               shmctl(shmid, IPC_RMID, NULL);
-       if (s_semid != -1)
-               semctl(s_semid, 0, IPC_RMID, 0);
-}
+/* our shared key */
+#define KEY_ID ((long)0x414e4547) /* "GENA" */
 
-void ipcsyslog_init(void){
-       if (buf == NULL){
-           if ((shmid = shmget(KEY_ID, shm_size, IPC_CREAT | 1023)) == -1)
-                       perror_msg_and_die("shmget");
+static void ipcsyslog_cleanup(void)
+{
+       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);
+       }
+}
 
+static void ipcsyslog_init(void)
+{
+       if (DEBUG)
+               printf("shmget(%lx, %d,...)\n", KEY_ID, G.shm_size);
 
-           if ((buf = shmat(shmid, NULL, 0)) == NULL)
-                       perror_msg_and_die("shmat");
+       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");
+       }
 
-           buf->size=data_size;
-           buf->head=buf->tail=0;
+       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)
-           if ((s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023)) == -1){
-               if (errno == EEXIST){
-                  if ((s_semid = semget(KEY_ID, 2, 0)) == -1)
-                   perror_msg_and_die("semget");
-               }else
-                       perror_msg_and_die("semget");
-           }
-       }else{
-               printf("Buffer already allocated just grab the semaphore?");
+       // 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");
        }
 }
 
-/* write message to buffer */
-void circ_message(const char *msg){
-       int l=strlen(msg)+1; /* count the whole message w/ '\0' included */
+/* Write message to shared mem buffer */
+static void log_to_shmem(const char *msg, int len)
+{
+       int old_tail, new_tail;
+       char *c;
 
-       sem_down(s_semid);
+       if (semop(G.s_semid, G.SMwdn, 3) == -1) {
+               bb_perror_msg_and_die("SMwdn");
+       }
 
-       /*
-        * Circular Buffer Algorithm:
+       /* Circular Buffer Algorithm:
         * --------------------------
-        *
-        * Start-off w/ empty buffer of specific size SHM_SIZ
-        * Start filling it up w/ messages. I use '\0' as separator to break up messages.
-        * This is also very handy since we can do printf on message.
-        *
-        * Once the buffer is full we need to get rid of the first message in buffer and
-        * insert the new message. (Note: if the message being added is >1 message then
-        * we will need to "remove" >1 old message from the buffer). The way this is done
-        * is the following:
-        *      When we reach the end of the buffer we set a mark and start from the beginning.
-        *      Now what about the beginning and end of the buffer? Well we have the "head"
-        *      index/pointer which is the starting point for the messages and we have "tail"
-        *      index/pointer which is the ending point for the messages. When we "display" the
-        *      messages we start from the beginning and continue until we reach "tail". If we
-        *      reach end of buffer, then we just start from the beginning (offset 0). "head" and
-        *      "tail" are actually offsets from the beginning of the buffer.
-        *
-        * Note: This algorithm uses Linux IPC mechanism w/ shared memory and semaphores to provide
-        *       a threasafe way of handling shared memory operations.
+        * 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.
         */
-       if ( (buf->tail + l) < buf->size ){
-               /* before we append the message we need to check the HEAD so that we won't
-                  overwrite any of the message that we still need and adjust HEAD to point
-                  to the next message! */
-               if ( buf->tail < buf->head){
-                       if ( (buf->tail + l) >= buf->head ){
-                         /* we need to move the HEAD to point to the next message
-                          * Theoretically we have enough room to add the whole message to the
-                          * buffer, because of the first outer IF statement, so we don't have
-                          * to worry about overflows here!
-                          */
-                          int k= buf->tail + l - buf->head; /* we need to know how many bytes
-                                                               we are overwriting to make
-                                                               enough room */
-                          char *c=memchr(buf->data+buf->head + k,'\0',buf->size - (buf->head + k));
-                          if (c != NULL) {/* do a sanity check just in case! */
-                               buf->head = c - buf->data + 1; /* we need to convert pointer to
-                                                                 offset + skip the '\0' since
-                                                                 we need to point to the beginning
-                                                                 of the next message */
-                               /* Note: HEAD is only used to "retrieve" messages, it's not used
-                                       when writing messages into our buffer */
-                          }else{ /* show an error message to know we messed up? */
-                               printf("Weird! Can't find the terminator token??? \n");
-                               buf->head=0;
-                          }
+       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;
                        }
-               } /* in other cases no overflows have been done yet, so we don't care! */
-
-               /* we should be ok to append the message now */
-               strncpy(buf->data + buf->tail,msg,l); /* append our message */
-               buf->tail+=l; /* count full message w/ '\0' terminating char */
-       }else{
-               /* we need to break up the message and "circle" it around */
-               char *c;
-               int k=buf->tail + l - buf->size; /* count # of bytes we don't fit */
-               
-               /* We need to move HEAD! This is always the case since we are going
-                * to "circle" the message.
-                */
-               c=memchr(buf->data + k ,'\0', buf->size - k);
-               
-               if (c != NULL) /* if we don't have '\0'??? weird!!! */{
-                       /* move head pointer*/
-                       buf->head=c-buf->data+1; 
-                       
-                       /* now write the first part of the message */                   
-                       strncpy(buf->data + buf->tail, msg, l - k - 1);
-                       
-                       /* ALWAYS terminate end of buffer w/ '\0' */
-                       buf->data[buf->size-1]='\0'; 
-                       
-                       /* now write out the rest of the string to the beginning of the buffer */
-                       strcpy(buf->data, &msg[l-k-1]);
-
-                       /* we need to place the TAIL at the end of the message */
-                       buf->tail = k + 1;
-               }else{
-                       printf("Weird! Can't find the terminator token from the beginning??? \n");
-                       buf->head = buf->tail = 0; /* reset buffer, since it's probably corrupted */
                }
-               
+               /* 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;
        }
-       sem_up(s_semid);
+       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);
 }
-#endif
-/* Note: There is also a function called "message()" in init.c */
+#else
+void ipcsyslog_cleanup(void);
+void ipcsyslog_init(void);
+void log_to_shmem(const char *msg);
+#endif /* FEATURE_IPC_SYSLOG */
+
+
 /* Print a message to the log file. */
-static void message (char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
-static void message (char *fmt, ...)
+static void log_locally(char *msg)
 {
-       int fd;
        struct flock fl;
-       va_list arguments;
+       int len = strlen(msg);
 
-       fl.l_whence = SEEK_SET;
-       fl.l_start  = 0;
-       fl.l_len    = 1;
-
-#ifdef BB_FEATURE_IPC_SYSLOG
-       if ((circular_logging == TRUE) && (buf != NULL)){
-                       char b[1024];
-                       va_start (arguments, fmt);
-                       vsprintf (b, fmt, arguments);
-                       va_end (arguments);
-                       circ_message(b);
-
-       }else
+#if ENABLE_FEATURE_IPC_SYSLOG
+       if ((option_mask32 & OPT_circularlog) && G.shbuf) {
+               log_to_shmem(msg, len);
+               return;
+       }
 #endif
-       if ((fd = device_open (logFilePath,
-                                                  O_WRONLY | O_CREAT | O_NOCTTY | O_APPEND |
-                                                  O_NONBLOCK)) >= 0) {
-               fl.l_type = F_WRLCK;
-               fcntl (fd, F_SETLKW, &fl);
-               va_start (arguments, fmt);
-               vdprintf (fd, fmt, arguments);
-               va_end (arguments);
-               fl.l_type = F_UNLCK;
-               fcntl (fd, F_SETLKW, &fl);
-               close (fd);
+       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 {
-               /* 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);
+ 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 logMessage (int pri, char *msg)
+static void parse_fac_prio_20(int pri, char *res20)
 {
-       time_t now;
-       char *timestamp;
-       static char res[20] = "";
        CODE *c_pri, *c_fac;
 
        if (pri != 0) {
-               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 == NULL || c_pri->c_name == NULL)
-                       snprintf(res, sizeof(res), "<%d>", pri);
-               else
-                       snprintf(res, sizeof(res), "%s.%s", c_fac->c_name, c_pri->c_name);
+               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);
        }
+}
 
-       if (strlen(msg) < 16 || msg[3] != ' ' || msg[6] != ' ' ||
-                       msg[9] != ':' || msg[12] != ':' || msg[15] != ' ') {
+/* 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)
+{
+       char *timestamp;
+
+       if (len < 16 || msg[3] != ' ' || msg[6] != ' '
+        || msg[9] != ':' || msg[12] != ':' || msg[15] != ' '
+       ) {
+               time_t now;
                time(&now);
                timestamp = ctime(&now) + 4;
-               timestamp[15] = '\0';
        } else {
                timestamp = msg;
-               timestamp[15] = '\0';
                msg += 16;
        }
-
-       /* todo: supress duplicates */
-
-#ifdef BB_FEATURE_REMOTE_LOG
-       /* send message to remote logger */
-       if ( -1 != remotefd){
-static const int IOV_COUNT = 2;
-               struct iovec iov[IOV_COUNT];
-               struct iovec *v = iov;
-
-               memset(&res, 0, sizeof(res));
-               snprintf(res, sizeof(res), "<%d>", pri);
-               v->iov_base = res ;
-               v->iov_len = strlen(res);          
-               v++;
-
-               v->iov_base = msg;
-               v->iov_len = strlen(msg);          
-
-               if ( -1 == writev(remotefd,iov, IOV_COUNT)){
-                       error_msg_and_die("syslogd: cannot write to remote file handle on" 
-                                       "%s:%d",RemoteHost,RemotePort);
+       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(PRINTBUF, "%s %s\n", timestamp, msg);
+                       else {
+                               char res[20];
+                               parse_fac_prio_20(pri, res);
+                               sprintf(PRINTBUF, "%s %s %s %s\n", timestamp, G.localHostName, res, msg);
+                       }
+                       log_locally(PRINTBUF);
                }
        }
-       if (local_logging == TRUE)
-#endif
-               /* now spew out the message to wherever it is supposed to go */
-               message("%s %s %s %s\n", timestamp, LocalHostName, res, msg);
-
-
-}
-
-static void quit_signal(int sig)
-{
-       logMessage(LOG_SYSLOG | LOG_INFO, "System log daemon exiting.");
-       unlink(lfile);
-#ifdef BB_FEATURE_IPC_SYSLOG
-       ipcsyslog_cleanup();
-#endif
-
-       exit(TRUE);
-}
-
-static void domark(int sig)
-{
-       if (MarkInterval > 0) {
-               logMessage(LOG_SYSLOG | LOG_INFO, "-- MARK --");
-               alarm(MarkInterval);
-       }
 }
 
-/* This must be a #define, since when DODEBUG and BUFFERS_GO_IN_BSS are
- * enabled, we otherwise get a "storage size isn't constant error. */
-#define BUFSIZE 1023
-static int serveConnection (int conn)
+static void split_escape_and_log(char *tmpbuf, int len)
 {
-       RESERVE_BB_BUFFER(tmpbuf, BUFSIZE + 1);
-       int    n_read;
-
-       n_read = read (conn, tmpbuf, BUFSIZE );
-
-       if (n_read > 0) {
-
-               int           pri = (LOG_USER | LOG_NOTICE);
-               char          line[ BUFSIZE + 1 ];
-               unsigned char c;
-
-               char *p = tmpbuf, *q = line;
-
-               tmpbuf[ n_read - 1 ] = '\0';
+       char *p = tmpbuf;
+
+       tmpbuf += len;
+       while (p < tmpbuf) {
+               char c;
+               char *q = 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);
+                       }
+               }
 
-               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)) {
+               while ((c = *p++)) {
+                       if (c == '\n')
+                               c = ' ';
+                       if (!(c & ~0x1f)) {
                                *q++ = '^';
-                               *q++ = c ^ 0100;
-                       } else {
-                               *q++ = c;
+                               c += '@'; /* ^@, ^A, ^B... */
                        }
-                       p++;
+                       *q++ = c;
                }
                *q = '\0';
                /* Now log it */
-               logMessage (pri, line);
+               timestamp_and_log(pri, PARSEBUF, q - PARSEBUF);
        }
-       return n_read;
 }
 
+static void quit_signal(int sig)
+{
+       timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)"syslogd exiting", 0);
+       puts("syslogd exiting");
+       if (ENABLE_FEATURE_IPC_SYSLOG)
+               ipcsyslog_cleanup();
+       exit(1);
+}
 
-#ifdef BB_FEATURE_REMOTE_LOG
-static void init_RemoteLog (void){
-
-  struct sockaddr_in remoteaddr;
-  struct hostent *hostinfo;
-  int len = sizeof(remoteaddr);
-
-  memset(&remoteaddr, 0, len);
-
-  remotefd = socket(AF_INET, SOCK_DGRAM, 0);
-
-  if (remotefd < 0) {
-    error_msg_and_die("syslogd: cannot create socket");
-  }
-
-  hostinfo = xgethostbyname(RemoteHost);
-
-  remoteaddr.sin_family = AF_INET;
-  remoteaddr.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
-  remoteaddr.sin_port = htons(RemotePort);
-
-  /* 
-     Since we are using UDP sockets, connect just sets the default host and port 
-     for future operations
-  */
-  if ( 0 != (connect(remotefd, (struct sockaddr *) &remoteaddr, len))){
-    error_msg_and_die("syslogd: cannot connect to remote host %s:%d", RemoteHost, RemotePort);
-  }
-
+#ifdef SYSLOGD_MARK
+static void do_mark(int sig)
+{
+       if (G.markInterval) {
+               timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)"-- MARK --", 0);
+               alarm(G.markInterval);
+       }
 }
 #endif
 
-static void doSyslogd (void) __attribute__ ((noreturn));
-static void doSyslogd (void)
+static void do_syslogd(void) ATTRIBUTE_NORETURN;
+static void do_syslogd(void)
 {
        struct sockaddr_un sunx;
-       socklen_t addrLength;
-
-
        int sock_fd;
        fd_set fds;
-
-       /* Set up signal handlers. */
-       signal (SIGINT,  quit_signal);
-       signal (SIGTERM, quit_signal);
-       signal (SIGQUIT, quit_signal);
-       signal (SIGHUP,  SIG_IGN);
-       signal (SIGCHLD,  SIG_IGN);
+       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);
+       signal(SIGCLD, SIG_IGN);
+#endif
+#ifdef SYSLOGD_MARK
+       signal(SIGALRM, do_mark);
+       alarm(G.markInterval);
 #endif
-       signal (SIGALRM, domark);
-       alarm (MarkInterval);
-
-       /* Create the syslog file so realpath() can work. */
-       if (realpath (_PATH_LOG, lfile) != NULL)
-               unlink (lfile);
 
-       memset (&sunx, 0, sizeof (sunx));
+       memset(&sunx, 0, sizeof(sunx));
        sunx.sun_family = AF_UNIX;
-       strncpy (sunx.sun_path, lfile, sizeof (sunx.sun_path));
-       if ((sock_fd = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
-               perror_msg_and_die ("Couldn't get file descriptor for socket " _PATH_LOG);
-
-       addrLength = sizeof (sunx.sun_family) + strlen (sunx.sun_path);
-       if ((bind (sock_fd, (struct sockaddr *) &sunx, addrLength)) || (listen (sock_fd, 5)))
-               perror_msg_and_die ("Could not connect to socket " _PATH_LOG);
-
-       if (chmod (lfile, 0666) < 0)
-               perror_msg_and_die ("Could not set permission on " _PATH_LOG);
+       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");
+       }
 
-       FD_ZERO (&fds);
-       FD_SET (sock_fd, &fds);
+       sock_fd = xsocket(AF_UNIX, SOCK_DGRAM, 0);
+       xbind(sock_fd, (struct sockaddr *) &sunx, sizeof(sunx));
 
-#ifdef BB_FEATURE_IPC_SYSLOG
-       if (circular_logging == TRUE ){
-          ipcsyslog_init();
+       if (chmod("/dev/log", 0666) < 0) {
+               bb_perror_msg_and_die("cannot set permission on /dev/log");
+       }
+       if (ENABLE_FEATURE_IPC_SYSLOG && (option_mask32 & OPT_circularlog)) {
+               ipcsyslog_init();
        }
-#endif
-
-        #ifdef BB_FEATURE_REMOTE_LOG
-        if (doRemoteLog == TRUE){
-          init_RemoteLog();
-        }
-        #endif
 
-       logMessage (LOG_SYSLOG | LOG_INFO, "syslogd started: " BB_BANNER);
+       timestamp_and_log(LOG_SYSLOG | LOG_INFO,
+                       (char*)"syslogd started: BusyBox v" BB_VER, 0);
 
        for (;;) {
+               FD_ZERO(&fds);
+               FD_SET(sock_fd, &fds);
 
-               fd_set readfds;
-               int    n_ready;
-               int    fd;
-
-               memcpy (&readfds, &fds, sizeof (fds));
-
-               if ((n_ready = select (FD_SETSIZE, &readfds, NULL, NULL, NULL)) < 0) {
-                       if (errno == EINTR) continue; /* alarm may have happened. */
-                       perror_msg_and_die ("select error");
+               if (select(sock_fd + 1, &fds, NULL, NULL, NULL) < 0) {
+                       if (errno == EINTR) {
+                               /* alarm may have happened */
+                               continue;
+                       }
+                       bb_perror_msg_and_die("select");
                }
 
-               for (fd = 0; (n_ready > 0) && (fd < FD_SETSIZE); fd++) {
-                       if (FD_ISSET (fd, &readfds)) {
-
-                               --n_ready;
-
-                               if (fd == sock_fd) {
-                                       int   conn;
-
-                                       //printf("New Connection request.\n");
-                                       if ((conn = accept (sock_fd, (struct sockaddr *) &sunx, &addrLength)) < 0) {
-                                               perror_msg_and_die ("accept error");
-                                       }
-
-                                       FD_SET(conn, &fds);
-                                       //printf("conn: %i, set_size: %i\n",conn,FD_SETSIZE);
-                               } else {
-                                       //printf("Serving connection: %i\n",fd);
-                                         if ( serveConnection(fd) <= 0 ) {
-                                           close (fd);
-                                           FD_CLR(fd, &fds);
-            }
-                               } /* fd == sock_fd */
-                       }/* FD_ISSET() */
-               }/* for */
-       } /* for main loop */
+               if (FD_ISSET(sock_fd, &fds)) {
+                       int i;
+                       i = recv(sock_fd, 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, RECVBUF, i, MSG_DONTWAIT,
+                                               &G.remoteAddr->sa, G.remoteAddr->len);
+                               }
+                       }
+#endif
+                       RECVBUF[i] = '\0';
+                       split_escape_and_log(RECVBUF, i);
+               } /* FD_ISSET() */
+       } /* for */
 }
 
-extern int syslogd_main(int argc, char **argv)
+int syslogd_main(int argc, char **argv);
+int syslogd_main(int argc, char **argv)
 {
-       int opt;
-       int doFork = TRUE;
-
+       char OPTION_DECL;
        char *p;
 
+       PTR_TO_GLOBALS = xzalloc(sizeof(G));
+       memcpy(ptr_to_globals, &init_globals, sizeof(init_globals));
+
        /* do normal option parsing */
-       while ((opt = getopt(argc, argv, "m:nO:R:LC")) > 0) {
-               switch (opt) {
-                       case 'm':
-                               MarkInterval = atoi(optarg) * 60;
-                               break;
-                       case 'n':
-                               doFork = FALSE;
-                               break;
-                       case 'O':
-                               logFilePath = strdup(optarg);
-                               break;
-#ifdef BB_FEATURE_REMOTE_LOG
-                       case 'R':
-                               RemoteHost = strdup(optarg);
-                               if ( (p = strchr(RemoteHost, ':'))){
-                                       RemotePort = atoi(p+1);
-                                       *p = '\0';
-                               }
-                               doRemoteLog = TRUE;
-                               break;
-                       case 'L':
-                               local_logging = TRUE;
-                               break;
+       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
-#ifdef BB_FEATURE_IPC_SYSLOG
-                       case 'C':
-                               circular_logging = TRUE;
-                               break;
+       //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
-                       default:
-                               show_usage();
-               }
+#if ENABLE_FEATURE_REMOTE_LOG
+       if (option_mask32 & OPT_remotelog) { // -R
+               G.remoteAddr = xhost2sockaddr(opt_R, 514);
        }
-
-#ifdef BB_FEATURE_REMOTE_LOG
-       /* If they have not specified remote logging, then log locally */
-       if (doRemoteLog == FALSE)
-               local_logging = TRUE;
+       //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(LocalHostName, sizeof(LocalHostName));
-       if ((p = strchr(LocalHostName, '.'))) {
-               *p++ = '\0';
+       gethostname(G.localHostName, sizeof(G.localHostName));
+       p = strchr(G.localHostName, '.');
+       if (p) {
+               *p = '\0';
        }
 
-       umask(0);
-
-       if (doFork == TRUE) {
-               if (daemon(0, 1) < 0)
-                       perror_msg_and_die("daemon");
+       if (!(option_mask32 & OPT_nofork)) {
+#ifdef BB_NOMMU
+               vfork_daemon_rexec(0, 1, argc, argv, "-n");
+#else
+               bb_daemonize();
+#endif
        }
-       doSyslogd();
-
-       return EXIT_SUCCESS;
+       umask(0);
+       do_syslogd();
+       /* return EXIT_SUCCESS; */
 }
-
-/*
-Local Variables
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/