OSDN Git Service

Fix bug in accepting buffer size argument
[android-x86/external-busybox.git] / sysklogd / syslogd.c
index f4e7f45..8534c0a 100644 (file)
@@ -2,11 +2,14 @@
 /*
  * Mini syslogd implementation for busybox
  *
- * Copyright (C) 1999,2000 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@gena01.com>
+ *
+ * Maintainer: Gennady Feldman <gfeldman@gena01.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
@@ -23,7 +26,6 @@
  *
  */
 
-#include "internal.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <paths.h>
 #include <signal.h>
 #include <stdarg.h>
+#include <stdbool.h>
 #include <time.h>
+#include <string.h>
 #include <unistd.h>
 #include <sys/socket.h>
-#include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/un.h>
 #include <sys/param.h>
-#include <linux/unistd.h>
-
-#if __GNU_LIBRARY__ < 5
-
-typedef unsigned int socklen_t;
-
-#ifndef __alpha__
-# define __NR_klogctl __NR_syslog
-static inline _syscall3(int, klogctl, int, type, char *, b, int, len);
-#else                                                  /* __alpha__ */
-#define klogctl syslog
-#endif
-
-#else
-# include <sys/klog.h>
-#endif
-
 
+#include "busybox.h"
 
 /* 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"
 
 /* Path to the unix socket */
-char lfile[BUFSIZ] = "";
+static char lfile[MAXPATHLEN];
+
+static const char *logFilePath = __LOG_FILE;
+
+#ifdef CONFIG_FEATURE_ROTATE_LOGFILE
+/* max size of message file before being rotated */
+static int logFileSize = 200 * 1024;
 
-static char *logFilePath = __LOG_FILE;
+/* number of rotated message files */
+static int logFileRotate = 1;
+#endif
 
 /* 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"
-#ifndef BB_FEATURE_TRIVIAL_HELP
-       "\nLinux 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 NUM\t\tInterval between MARK lines (default=20min, 0=off)\n"
-       "\t-n\t\tRun as a foreground process\n"
-#ifdef BB_KLOGD
-       "\t-K\t\tDo not start up the klogd process\n"
+static char LocalHostName[64];
+
+#ifdef CONFIG_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;
 #endif
-       "\t-O FILE\t\tUse an alternate log file (default=/var/log/messages)\n"
+
+/* Make loging output smaller. */
+static bool small = false;
+
+
+#define MAXLINE         1024   /* maximum line length */
+
+
+/* circular buffer variables/structures */
+#ifdef CONFIG_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
-       ;
+
+#include <sys/ipc.h>
+#include <sys/sem.h>
+#include <sys/shm.h>
+
+/* our shared key */
+static const long KEY_ID = 0x414e4547; /*"GENA" */
+
+// 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
+static int shm_size = ((CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE)*1024);  // default shm size
+static int circular_logging = FALSE;
+
+/*
+ * sem_up - up()'s a semaphore.
+ */
+static inline void sem_up(int semid)
+{
+       if (semop(semid, SMwup, 1) == -1) {
+               bb_perror_msg_and_die("semop[SMwup]");
+       }
+}
+
+/*
+ * sem_down - down()'s a semaphore
+ */
+static inline void sem_down(int semid)
+{
+       if (semop(semid, SMwdn, 3) == -1) {
+               bb_perror_msg_and_die("semop[SMwdn]");
+       }
+}
+
+
+void ipcsyslog_cleanup(void)
+{
+       printf("Exiting Syslogd!\n");
+       if (shmid != -1) {
+               shmdt(buf);
+       }
+
+       if (shmid != -1) {
+               shmctl(shmid, IPC_RMID, NULL);
+       }
+       if (s_semid != -1) {
+               semctl(s_semid, 0, IPC_RMID, 0);
+       }
+}
+
+void ipcsyslog_init(void)
+{
+       if (buf == NULL) {
+               if ((shmid = shmget(KEY_ID, shm_size, IPC_CREAT | 1023)) == -1) {
+                       bb_perror_msg_and_die("shmget");
+               }
+
+               if ((buf = shmat(shmid, NULL, 0)) == NULL) {
+                       bb_perror_msg_and_die("shmat");
+               }
+
+               buf->size = shm_size - sizeof(*buf);
+               buf->head = buf->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) {
+                                       bb_perror_msg_and_die("semget");
+                               }
+                       } else {
+                               bb_perror_msg_and_die("semget");
+                       }
+               }
+       } else {
+               printf("Buffer already allocated just grab the semaphore?");
+       }
+}
+
+/* write message to buffer */
+void circ_message(const char *msg)
+{
+       int l = strlen(msg) + 1;        /* count the whole message w/ '\0' included */
+
+       sem_down(s_semid);
+
+       /*
+        * 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.
+        */
+       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;
+                               }
+                       }
+               }
+
+               /* 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 */
+               }
+
+       }
+       sem_up(s_semid);
+}
+#endif                                                 /* CONFIG_FEATURE_IPC_SYSLOG */
 
 /* Note: There is also a function called "message()" in init.c */
 /* Print a message to the log file. */
-static void message (char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
-static void message (char *fmt, ...)
+static void message(char *fmt, ...) __attribute__ ((format(printf, 1, 2)));
+static void message(char *fmt, ...)
 {
        int fd;
        struct flock fl;
        va_list arguments;
 
        fl.l_whence = SEEK_SET;
-       fl.l_start  = 0;
-       fl.l_len    = 1;
+       fl.l_start = 0;
+       fl.l_len = 1;
 
-       if ((fd = device_open (logFilePath,
-                                                  O_WRONLY | O_CREAT | O_NOCTTY | O_APPEND |
-                                                  O_NONBLOCK)) >= 0) {
+#ifdef CONFIG_FEATURE_IPC_SYSLOG
+       if ((circular_logging == TRUE) && (buf != NULL)) {
+               char b[1024];
+
+               va_start(arguments, fmt);
+               vsnprintf(b, sizeof(b) - 1, fmt, arguments);
+               va_end(arguments);
+               circ_message(b);
+
+       } else
+#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);
+               fcntl(fd, F_SETLKW, &fl);
+#ifdef CONFIG_FEATURE_ROTATE_LOGFILE
+               if ( logFileSize > 0 ) {
+                       struct stat statf;
+                       int r = fstat(fd, &statf);
+                       if( !r && (statf.st_mode & S_IFREG)
+                               && (lseek(fd,0,SEEK_END) > logFileSize) ) {
+                               if(logFileRotate > 0) {
+                                       int i;
+                                       char oldFile[(strlen(logFilePath)+3)], newFile[(strlen(logFilePath)+3)];
+                                       for(i=logFileRotate-1;i>0;i--) {
+                                               sprintf(oldFile, "%s.%d", logFilePath, i-1);
+                                               sprintf(newFile, "%s.%d", logFilePath, i);
+                                               rename(oldFile, newFile);
+                                       }
+                                       sprintf(newFile, "%s.%d", logFilePath, 0);
+                                       fl.l_type = F_UNLCK;
+                                       fcntl (fd, F_SETLKW, &fl);
+                                       close(fd);
+                                       rename(logFilePath, newFile);
+                                       fd = device_open (logFilePath,
+                                                  O_WRONLY | O_CREAT | O_NOCTTY | O_APPEND |
+                                                  O_NONBLOCK);
+                                       fl.l_type = F_WRLCK;
+                                       fcntl (fd, F_SETLKW, &fl);
+                               } else {
+                                       ftruncate( fd, 0 );
+                               }
+                       }
+               }
+#endif
+               va_start(arguments, fmt);
+               vdprintf(fd, fmt, arguments);
+               va_end(arguments);
                fl.l_type = F_UNLCK;
-               fcntl (fd, F_SETLKW, &fl);
-               close (fd);
+               fcntl(fd, F_SETLKW, &fl);
+               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);
+               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);
+                       fprintf(stderr, "Bummer, can't print: ");
+                       va_start(arguments, fmt);
+                       vfprintf(stderr, fmt, arguments);
+                       fflush(stderr);
+                       va_end(arguments);
                }
        }
 }
 
-static void logMessage (int pri, char *msg)
+static void logMessage(int pri, char *msg)
 {
        time_t now;
        char *timestamp;
@@ -146,10 +390,11 @@ static void logMessage (int pri, char *msg)
                         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')
+               if (c_fac->c_name == NULL || c_pri->c_name == NULL) {
                        snprintf(res, sizeof(res), "<%d>", pri);
-               else
+               } else {
                        snprintf(res, sizeof(res), "%s.%s", c_fac->c_name, c_pri->c_name);
+               }
        }
 
        if (strlen(msg) < 16 || msg[3] != ' ' || msg[6] != ' ' ||
@@ -165,14 +410,45 @@ static void logMessage (int pri, char *msg)
 
        /* todo: supress duplicates */
 
-       /* now spew out the message to wherever it is supposed to go */
-       message("%s %s %s %s\n", timestamp, LocalHostName, res, msg);
+#ifdef CONFIG_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);
+         writev_retry:
+               if ((-1 == writev(remotefd, iov, IOV_COUNT)) && (errno == EINTR)) {
+                       goto writev_retry;
+               }
+       }
+       if (local_logging == TRUE)
+#endif
+       {
+               /* now spew out the message to wherever it is supposed to go */
+               if (small)
+                       message("%s %s\n", timestamp, msg);
+               else
+                       message("%s %s %s %s\n", timestamp, LocalHostName, res, msg);
+       }
 }
 
 static void quit_signal(int sig)
 {
-       logMessage(0, "System log daemon exiting.");
+       logMessage(LOG_SYSLOG | LOG_INFO, "System log daemon exiting.");
        unlink(lfile);
+#ifdef CONFIG_FEATURE_IPC_SYSLOG
+       ipcsyslog_cleanup();
+#endif
+
        exit(TRUE);
 }
 
@@ -184,34 +460,34 @@ static void domark(int sig)
        }
 }
 
-#define BUFSIZE 1023
-static int serveConnection (int conn)
+/* This must be a #define, since when CONFIG_DEBUG and BUFFERS_GO_IN_BSS are
+ * enabled, we otherwise get a "storage size isn't constant error. */
+static int serveConnection(char *tmpbuf, int n_read)
 {
-       char   buf[ BUFSIZE + 1 ];
-       int    n_read;
+       char *p = tmpbuf;
 
-       while ((n_read = read (conn, buf, BUFSIZE )) > 0) {
+       while (p < tmpbuf + n_read) {
 
-               int           pri = (LOG_USER | LOG_NOTICE);
-               char          line[ BUFSIZE + 1 ];
+               int pri = (LOG_USER | LOG_NOTICE);
+               int num_lt = 0;
+               char line[MAXLINE + 1];
                unsigned char c;
+               char *q = line;
 
-               char *p = buf, *q = line;
-
-               buf[ n_read - 1 ] = '\0';
-
-               while (p && (c = *p) && q < &line[ sizeof (line) - 1 ]) {
-                       if (c == '<') {
-                       /* Parse the magic priority number. */
+               while ((c = *p) && q < &line[sizeof(line) - 1]) {
+                       if (c == '<' && num_lt == 0) {
+                               /* Parse the magic priority number. */
+                               num_lt++;
                                pri = 0;
-                               while (isdigit (*(++p))) {
+                               while (isdigit(*(++p))) {
                                        pri = 10 * pri + (*p - '0');
                                }
-                               if (pri & ~(LOG_FACMASK | LOG_PRIMASK))
+                               if (pri & ~(LOG_FACMASK | LOG_PRIMASK)) {
                                        pri = (LOG_USER | LOG_NOTICE);
+                               }
                        } else if (c == '\n') {
                                *q++ = ' ';
-                       } else if (iscntrl (c) && (c < 0177)) {
+                       } else if (iscntrl(c) && (c < 0177)) {
                                *q++ = '^';
                                *q++ = c ^ 0100;
                        } else {
@@ -220,264 +496,219 @@ static int serveConnection (int conn)
                        p++;
                }
                *q = '\0';
+               p++;
                /* Now log it */
-               logMessage (pri, line);
+               logMessage(pri, line);
        }
-       return (0);
+       return n_read;
 }
 
-static void doSyslogd (void) __attribute__ ((noreturn));
-static void doSyslogd (void)
-{
-       struct sockaddr_un sunx;
-       socklen_t addrLength;
-
-
-       int sock_fd;
-       fd_set fds;
-
-       char lfile[BUFSIZ];
 
-       /* Set up signal handlers. */
-       signal (SIGINT,  quit_signal);
-       signal (SIGTERM, quit_signal);
-       signal (SIGQUIT, quit_signal);
-       signal (SIGHUP,  SIG_IGN);
-       signal (SIGCLD,  SIG_IGN);
-       signal (SIGALRM, domark);
-       alarm (MarkInterval);
-
-       /* Create the syslog file so realpath() can work. */
-       close (open (_PATH_LOG, O_RDWR | O_CREAT, 0644));
-       if (realpath (_PATH_LOG, lfile) == NULL)
-               fatalError ("Could not resolv path to " _PATH_LOG ": %s\n", strerror (errno));
-
-       unlink (lfile);
-
-       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)
-               fatalError ("Couldn't obtain descriptor for socket " _PATH_LOG ": %s\n", strerror (errno));
-
-       addrLength = sizeof (sunx.sun_family) + strlen (sunx.sun_path);
-       if ((bind (sock_fd, (struct sockaddr *) &sunx, addrLength)) || (listen (sock_fd, 5)))
-               fatalError ("Could not connect to socket " _PATH_LOG ": %s\n", strerror (errno));
+#ifdef CONFIG_FEATURE_REMOTE_LOG
+static void init_RemoteLog(void)
+{
 
-       if (chmod (lfile, 0666) < 0)
-               fatalError ("Could not set permission on " _PATH_LOG ": %s\n", strerror (errno));
+       struct sockaddr_in remoteaddr;
+       struct hostent *hostinfo;
+       int len = sizeof(remoteaddr);
 
-       FD_ZERO (&fds);
-       FD_SET (sock_fd, &fds);
+       memset(&remoteaddr, 0, len);
 
-       logMessage (0, "syslogd started: BusyBox v" BB_VER " (" BB_BT ")");
+       remotefd = socket(AF_INET, SOCK_DGRAM, 0);
 
-       for (;;) {
-
-               fd_set readfds;
-               int    n_ready;
-               int    fd;
+       if (remotefd < 0) {
+               bb_error_msg_and_die("cannot create socket");
+       }
 
-               memcpy (&readfds, &fds, sizeof (fds));
+       hostinfo = xgethostbyname(RemoteHost);
 
-               if ((n_ready = select (FD_SETSIZE, &readfds, NULL, NULL, NULL)) < 0) {
-                       if (errno == EINTR) continue; /* alarm may have happened. */
-                       fatalError ("select error: %s\n", strerror (errno));
-               }
+       remoteaddr.sin_family = AF_INET;
+       remoteaddr.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
+       remoteaddr.sin_port = htons(RemotePort);
 
-               for (fd = 0; (n_ready > 0) && (fd < FD_SETSIZE); fd++) {
-                       if (FD_ISSET (fd, &readfds)) {
+       /* 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))) {
+               bb_error_msg_and_die("cannot connect to remote host %s:%d", RemoteHost,
+                                                 RemotePort);
+       }
 
-                               --n_ready;
+}
+#endif
 
-                               if (fd == sock_fd) {
+static void doSyslogd(void) __attribute__ ((noreturn));
+static void doSyslogd(void)
+{
+       struct sockaddr_un sunx;
+       socklen_t addrLength;
 
-                                       int   conn;
-                                       pid_t pid;
+       int sock_fd;
+       fd_set fds;
 
-                                       if ((conn = accept (sock_fd, (struct sockaddr *) &sunx, &addrLength)) < 0) {
-                                               fatalError ("accept error: %s\n", strerror (errno));
-                                       }
+       /* 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
+       signal(SIGALRM, domark);
+       alarm(MarkInterval);
 
-                                       pid = fork();
+       /* Create the syslog file so realpath() can work. */
+       if (realpath(_PATH_LOG, lfile) != NULL) {
+               unlink(lfile);
+       }
 
-                                       if (pid < 0) {
-                                               perror ("syslogd: fork");
-                                               close (conn);
-                                               continue;
-                                       }
+       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_DGRAM, 0)) < 0) {
+               bb_perror_msg_and_die("Couldn't get file descriptor for socket "
+                                                  _PATH_LOG);
+       }
 
-                                       if (pid == 0)
-                                               serveConnection (conn);
-                                       close (conn);
-                               }
-                       }
-               }
+       addrLength = sizeof(sunx.sun_family) + strlen(sunx.sun_path);
+       if (bind(sock_fd, (struct sockaddr *) &sunx, addrLength) < 0) {
+               bb_perror_msg_and_die("Could not connect to socket " _PATH_LOG);
        }
-}
 
-#ifdef BB_KLOGD
+       if (chmod(lfile, 0666) < 0) {
+               bb_perror_msg_and_die("Could not set permission on " _PATH_LOG);
+       }
+#ifdef CONFIG_FEATURE_IPC_SYSLOG
+       if (circular_logging == TRUE) {
+               ipcsyslog_init();
+       }
+#endif
 
-static void klogd_signal(int sig)
-{
-       klogctl(7, NULL, 0);
-       klogctl(0, 0, 0);
-       logMessage(0, "Kernel log daemon exiting.");
-       exit(TRUE);
-}
+#ifdef CONFIG_FEATURE_REMOTE_LOG
+       if (doRemoteLog == TRUE) {
+               init_RemoteLog();
+       }
+#endif
 
-static void doKlogd (void) __attribute__ ((noreturn));
-static void doKlogd (void)
-{
-       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, SIG_IGN);
-       logMessage(0, "klogd started: "
-                          "BusyBox v" BB_VER " (" BB_BT ")");
+       logMessage(LOG_SYSLOG | LOG_INFO, "syslogd started: " BB_BANNER);
 
-       klogctl(1, NULL, 0);
+       for (;;) {
 
-       while (1) {
-               /* Use kernel syscalls */
-               memset(log_buffer, '\0', sizeof(log_buffer));
-               if (klogctl(2, log_buffer, sizeof(log_buffer)) < 0) {
-                       char message[80];
+               FD_ZERO(&fds);
+               FD_SET(sock_fd, &fds);
 
-                       if (errno == EINTR)
+               if (select(sock_fd + 1, &fds, NULL, NULL, NULL) < 0) {
+                       if (errno == EINTR) {
+                               /* alarm may have happened. */
                                continue;
-                       snprintf(message, 79, "klogd: Error return from sys_sycall: " \
-                                        "%d - %s.\n", errno, strerror(errno));
-                       logMessage(LOG_SYSLOG | LOG_ERR, message);
-                       exit(1);
-               }
-               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;
+                       bb_perror_msg_and_die("select error");
                }
-               logMessage(LOG_KERN | priority, logp);
-       }
 
-}
+               if (FD_ISSET(sock_fd, &fds)) {
+                       int i;
 
-#endif
+                       RESERVE_CONFIG_BUFFER(tmpbuf, MAXLINE + 1);
 
-static void daemon_init (char **argv, char *dz, void fn (void))
-{
-       setsid();
-       chdir ("/");
-       strncpy(argv[0], dz, strlen(argv[0]));
-       fn();
-       exit(0);
+                       memset(tmpbuf, '\0', MAXLINE + 1);
+                       if ((i = recv(sock_fd, tmpbuf, MAXLINE, 0)) > 0) {
+                               serveConnection(tmpbuf, i);
+                       } else {
+                               bb_perror_msg_and_die("UNIX socket error");
+                       }
+                       RELEASE_CONFIG_BUFFER(tmpbuf);
+               }                               /* FD_ISSET() */
+       }                                       /* for main loop */
 }
 
 extern int syslogd_main(int argc, char **argv)
 {
-       int pid, klogd_pid;
+       int opt;
+
        int doFork = TRUE;
 
-#ifdef BB_KLOGD
-       int startKlogd = TRUE;
-#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;
+
+       /* do normal option parsing */
+       while ((opt = getopt(argc, argv, "m:nO:s:Sb:R:LC:")) > 0) {
+               switch (opt) {
+               case 'm':
+                       MarkInterval = atoi(optarg) * 60;
+                       break;
+               case 'n':
+                       doFork = FALSE;
+                       break;
+               case 'O':
+                       logFilePath = optarg;
+                       break;
+#ifdef CONFIG_FEATURE_ROTATE_LOGFILE
+               case 's':
+                       logFileSize = atoi(optarg) * 1024;
+                       break;
+               case 'b':
+                       logFileRotate = atoi(optarg);
+                       if( logFileRotate > 99 ) logFileRotate = 99;
+                       break;
 #endif
-                       case 'O':
-                               if (--argc == 0) {
-                                       usage(syslogd_usage);
+#ifdef CONFIG_FEATURE_REMOTE_LOG
+               case 'R':
+                       RemoteHost = bb_xstrdup(optarg);
+                       if ((p = strchr(RemoteHost, ':'))) {
+                               RemotePort = atoi(p + 1);
+                               *p = '\0';
+                       }
+                       doRemoteLog = TRUE;
+                       break;
+               case 'L':
+                       local_logging = TRUE;
+                       break;
+#endif
+#ifdef CONFIG_FEATURE_IPC_SYSLOG
+               case 'C':
+                       if (optarg) {
+                               int buf_size = atoi(optarg);
+                               if (buf_size >= 4) {
+                                       shm_size = buf_size * 1024;
                                }
-                               logFilePath = *(++argv1);
-                               stopDoingThat = TRUE;
-                               break;
-                       default:
-                               usage(syslogd_usage);
                        }
+                       circular_logging = TRUE;
+                       break;
+#endif
+               case 'S':
+                       small = true;
+                       break;
+               default:
+                       bb_show_usage();
                }
        }
 
-       if (argc > 0)
-               usage(syslogd_usage);
+#ifdef CONFIG_FEATURE_REMOTE_LOG
+       /* If they have not specified remote logging, then log locally */
+       if (doRemoteLog == FALSE)
+               local_logging = TRUE;
+#endif
+
 
        /* Store away localhost's name before the fork */
        gethostname(LocalHostName, sizeof(LocalHostName));
        if ((p = strchr(LocalHostName, '.'))) {
-               *p++ = '\0';
+               *p = '\0';
        }
 
        umask(0);
 
-#ifdef BB_KLOGD
-       /* Start up the klogd process */
-       if (startKlogd == TRUE) {
-               klogd_pid = fork();
-               if (klogd_pid == 0) {
-                       daemon_init (argv, "klogd", doKlogd);
-               }
-       }
-#endif
-
        if (doFork == TRUE) {
-               pid = fork();
-               if (pid < 0)
-                       exit(pid);
-               else if (pid == 0) {
-                       daemon_init (argv, "syslogd", doSyslogd);
-               }
-       } else {
-               doSyslogd();
+#if defined(__uClinux__)
+               vfork_daemon_rexec(0, 1, argc, argv, "-n");
+#else /* __uClinux__ */
+               if(daemon(0, 1) < 0)
+                       bb_perror_msg_and_die("daemon");
+#endif /* __uClinux__ */
        }
+       doSyslogd();
 
-       return(TRUE);
+       return EXIT_SUCCESS;
 }
 
 /*