[bug-inetutils] syslogd - clog.patch - port clog from bsd version to inetutils linux

[Daniel Lehne]

Hello,

i've tried to create a patch for the inetutils, which adds a circular log functionality of Jeff Wheelhouse (http://software.wwwi.com/syslogd/) to the inetutils/syslogd. The patch is ported form BSD version of Jeff Wheelhouse to the inetuitls-1.6 version. The patch reference to the root dirctory "inetutils-1.6" and is created in the following way:
quilt new clog
quilt add Makefile.am clog/clog.8 clog/clog.c clog/clog.h clog/Makefile.am syslogd/syslogd.c syslogd/Makefile.am syslogd/syslog.conf.5
quilt refresh

The patch is not working because of the following reasons. The clog tool is not included in build and the reasons are unkown. Changes in inetutils-1.6/configure.ac are failed to achieve this. The syslogd couldn't build because of missing clog.h in inetutils/lib, assuming that clog.h automatically copied to inetutils-1.6/lib in install process of clog. The syslogd depends on clog.

All try to compile for an arm with OSELAS.Toolchain-2011.03.0 toolchain using ptx2.

Any suggests, what's my mistake? Thanks for support!

Best regards
Daniel Lehne

The patch contains the following:
Index: inetutils-1.6/Makefile.am
===================================================================
--- inetutils-1.6.orig/Makefile.am    2011-11-30 10:48:56.689500265 +0200
+++ inetutils-1.6/Makefile.am    2011-11-30 10:49:18.769499826 +0200
@@ -23,7 +23,7 @@
 EXTRA_DIST = README-alpha paths ChangeLog.0
 
 SUBDIRS = lib headers libinetutils libtelnet \
-    hostname inetd telnetd libls ftpd rshd rlogind uucpd rexecd syslogd \
+    hostname inetd telnetd libls ftpd rshd rlogind uucpd rexecd clog syslogd \
     tftpd talkd telnet ftp rsh rcp rlogin tftp logger gwhois talk \
     libicmp ping doc ifconfig traceroute tests
 
Index: inetutils-1.6/clog/Makefile.am
===================================================================
--- /dev/null    1970-01-01 00:00:00.000000000 +0000
+++ inetutils-1.6/clog/Makefile.am    2011-11-30 10:49:18.769499826 +0200
@@ -0,0 +1,31 @@
+# Copyright (C) 2008 Free Software Foundation, Inc.
+# This file is part of GNU Inetutils.
+#
+# GNU Inetutils 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 3, or (at your option)
+# any later version.
+#
+# GNU Inetutils is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR 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 GNU Inetutils; see the file COPYING.  If not, write
+# to the Free Software Foundation, Inc., 51 Franklin Street,
+# Fifth Floor, Boston, MA 02110-1301 USA.
+
+bin_PROGRAMS = @clog_BUILD@
+
+EXTRA_PROGRAMS = clog
+
+clog_SOURCES = clog.c
+
+man_MANS = clog.8
+
+INCLUDES = -I$(top_srcdir)/lib -I$(top_srcdir)/libinetutils
+
+LDADD = -L$(top_builddir)/lib -lgnu
+
+EXTRA_DIST = $(man_MANS)
Index: inetutils-1.6/clog/clog.8
===================================================================
--- /dev/null    1970-01-01 00:00:00.000000000 +0000
+++ inetutils-1.6/clog/clog.8    2011-11-30 10:49:18.769499826 +0200
@@ -0,0 +1,98 @@
+.\" Copyright (c) 2001
+.\"    Jeffrey D. Wheelhouse.  All rights reserved.
+.\"
+.\" This code was originally developed by Jeff Wheelhouse (address@hidden).
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY JEFF WHEELHOUSE ``AS IS'' AND ANY EXPRESS OR
+.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
+.\" NO EVENT SHALL JEFF WHEELHOUSE BE LIABLE FOR ANY DIRECT, INDIRECT,
+.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING BUT NOT
+.\" LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
+.\" OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+.\" LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+.\" NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.\"
+.\"     $Id: clog.8,v 1.2 2001/10/02 04:41:21 jdw Exp $
+.\"
+.Dd October 1, 2001
+.Dt CLOG 8
+.Os BSD 4
+.Sh NAME
+.Nm clog
+.Nd "display or initialize a circular system log"
+.Sh SYNOPSIS
+.Nm
+.Op Fl f
+.Op Fl i Fl s Ar size
+.Ar logfile
+.Sh DESCRIPTION
+.Nm Clog
+displays or initializes a circular log file.
+.Pp
+The options are as follows:
+.Bl -tag -width indent
+.It Fl f
+Display the contents of the circular logfile
+.Ar logfile ,
+then go into a loop waiting for
+new material to arrive.  This is essentially the same as using the
+.Fl f
+option of the
+.Xr tail 1
+command on a standard syslog file.
+.It Fl i
+Initialize
+.Ar logfile
+rather than reading it.  This option requires the
+.Fl s
+option.  If
+.Ar logfile
+already exists, it will be truncated and recreated by this command.
+.It Fl s
+This option specifies the size in bytes of the circular logfile that should
+be created.  This option requires the
+.Fl i
+option.
+.El
+.Sh ABOUT CIRCULAR LOGFILES
+The
+.Nm
+command supports circular logfiles for
+.Xr syslogd 8 .
+A circular logfile differs from a standard syslog file in that is has a fixed
+size.  It does not grow, and does not need to be rotated.  When
+.Xr syslogd 8
+reaches the end of a circular logfile, it simply begins again at the beginning,
+overwriting the oldest data.  The circular logfile also contains information
+allowing
+.Nm
+to establish what parts of the file are valid, and in what order they should
+be displayed.
+.Pp
+Circular logfiles are primarily useful for their ability to control the amount
+of storage devoted to logfiles.  This may be valuable when storage space is
+at a premium or when the consequences of running out of storage space are
+unacceptable.  Circular logfiles can safely be used on a memory disk (see
+.Xr md 4 ).
+.Pp
+Circular logfiles are also useful to catch messages that are generated rapidly
+but soon lose relevance, such as messages logged at debug priority.
+
+.Sh SEE ALSO
+.Xr syslogd 8 ,
+.Xr syslog.conf 5
+.Sh HISTORY
+The
+.Nm
+command was written for FreeBSD 4.3 but is not yet part of a BSD distribution.
Index: inetutils-1.6/clog/clog.c
===================================================================
--- /dev/null    1970-01-01 00:00:00.000000000 +0000
+++ inetutils-1.6/clog/clog.c    2011-11-30 10:49:18.769499826 +0200
@@ -0,0 +1,226 @@
+/*-
+ * Copyright (c) 2001
+ *     Jeff Wheelhouse (address@hidden)
+ *
+ * This code was originally developed by Jeff Wheelhouse (address@hidden).
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistribution of source code must retail the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JEFF WHEELHOUSE ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
+ * NO EVENT SHALL JEFF WHEELHOUSE BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
+ * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *  $Id: clog.c,v 1.3 2001/10/02 18:51:26 jdw Exp $
+ */
+
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdint.h>
+
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/uio.h>
+
+
+#include "clog.h"
+
+
+/*
+ *  The BUFFER_SIZE value is just used to allocate a buffer full of NULLs
+ *  so that a new logfile can be extended to its full size.
+ *
+ *  Compiling with -pedantic complains when the buffer array is declared
+ *  if I declare this as a const instead of a #define.
+ */
+#define BUFFER_SIZE 16384
+
+void init_log __P((const char *lname, size_t size));
+void read_log __P((const char *lname, int optf));
+void usage __P((void));
+
+const char *pname;
+
+int main(int argc, char **argv) {
+    int ch;
+    int init = 0;
+    int size = 0;
+    int optf = 0;
+
+    pname = argv[0];
+
+    while ((ch = getopt(argc, argv, "fis:")) != -1)
+        switch(ch) {
+        case 'i':
+            init = 1;
+            break;
+        case 's':
+            size = atol(optarg);
+            if (size==0) usage();
+            break;
+        case 'f':
+            optf = 1;
+        }
+
+    if ((size>0)&&(init==0)) {
+        fprintf(stderr,"%s: WARNING: -s argument ignored without -i.\n",pname);
+        size = 0;
+    }
+    if (argv[optind]==NULL) {
+        fprintf(stderr,"%s: ERROR: log_file argument must be specified.\n",pname);
+        usage();
+    }
+    if ((init==1)&&(size==0)) {
+        fprintf(stderr,"%s: ERROR: -i argument requires -s.\n",pname);
+        usage();
+    }
+    if ((init==1)&&(optf==1)) {
+        fprintf(stderr,"%s: ERROR: flags -f and -i are incompatible.\n",pname);
+        usage();
+    }
+
+    if (init==1) init_log(argv[optind],size);
+    /* if (optf==1) follow_log(artv[optind]); */
+    read_log(argv[optind],optf);
+       
+    return 0;
+}
+
+
+void usage() {
+  fprintf(stderr,"usage: %s [-i -s log_size] [ -f ] log_file\n",pname);
+  exit(1);
+}
+
+
+void read_log(const char *lname, int optf) {
+    int fd;
+    struct stat sb;
+    struct clog_footer *pcf;
+    char *pbuffer;
+    struct iovec iov[2];
+    int iovcnt = 0;
+    uint32_t start = 0;
+    uint32_t next;
+    struct pollfd pfd;
+
+    pfd.fd = -1;
+
+    fd = open(lname,O_RDONLY);
+    if (fd==-1) {
+        fprintf(stderr,"%s: ERROR: could not open %s (%s)\n",pname,lname,strerror(errno));
+        exit(11);
+    }
+
+    if (fstat(fd,&sb)==-1) {
+        fprintf(stderr,"%s: ERROR: could not stat %s (%s)\n",pname,lname,strerror(errno));
+        exit(13);
+    }
+    pbuffer = (char*)mmap(NULL,sb.st_size,PROT_READ,MAP_SHARED,fd,0);
+    if (pbuffer==NULL) {
+        fprintf(stderr,"%s: ERROR: could not mmap %s body (%s)\n",pname,lname,strerror(errno));
+        exit(14);
+    }
+    pcf = (struct clog_footer*)(pbuffer + sb.st_size - sizeof(struct clog_footer));
+
+    if (pcf->cf_wrap==1) start = pcf->cf_next + 1;
+    while(1) {
+        while(pcf->cf_lock==1) sched_yield();
+        next = pcf->cf_next;
+        iovcnt = 0;
+        if (start>next) {
+            iov[iovcnt].iov_base = pbuffer + start;
+            iov[iovcnt++].iov_len = pcf->cf_max - start;
+            start = 0;
+        }
+        iov[iovcnt].iov_base = pbuffer + start;
+        iov[iovcnt++].iov_len = next - start;
+        if (writev(1,iov,iovcnt)==-1) {
+            fprintf(stderr,"%s: ERROR: could not write output (%s)\n",pname,strerror(errno));
+            exit(15);
+        }
+        start = next;
+        if (optf==0) break;
+        if (poll(&pfd,1,50)==-1) {
+            fprintf(stderr,"%s: ERROR: could not poll (%s)\n",pname,strerror(errno));
+            exit(16);
+        }
+    }
+   
+    (void)munmap(pbuffer,sb.st_size);
+    (void)close(fd);
+
+    exit(0);
+}
+
+
+void init_log(const char *lname, size_t size) {
+    int fd;
+    size_t fill = size;
+    char buffer[BUFFER_SIZE];
+    struct clog_footer cf;
+
+    memcpy(&cf.cf_magic,MAGIC_CONST,4);
+    cf.cf_max = size - sizeof(struct clog_footer);
+
+    (void)memset(buffer,0,BUFFER_SIZE);
+
+    fd = open(lname,O_RDWR|O_CREAT,0666);
+    if (fd==-1) {
+        fprintf(stderr,"%s: ERROR: could not open %s (%s)\n",pname,lname,strerror(errno));
+        exit(2);
+    }
+    if (ftruncate(fd,(off_t)0)==-1) {
+        fprintf(stderr,"%s: ERROR: could not truncate %s (%s)\n",pname,lname,strerror(errno));
+        exit(3);
+    }
+   
+    while(fill>BUFFER_SIZE) {
+        if (write(fd,buffer,BUFFER_SIZE)==-1){
+            fprintf(stderr,"%s: ERROR: could not write %s (%s)\n",pname,lname,strerror(errno));
+            exit(4);
+        }
+        fill -= BUFFER_SIZE;
+    }
+    assert(fill<=BUFFER_SIZE);
+    if (fill>0) {
+        if (write(fd,buffer,fill)==-1) {
+            fprintf(stderr,"%s: ERROR: could not write %s (%s)\n",pname,lname,strerror(errno));
+            exit(5);
+        }
+    }
+    if (lseek(fd,-(off_t)(sizeof(struct clog_footer)),SEEK_END)==-1) {
+        fprintf(stderr,"%s: ERROR: could not seek in %s (%s)\n",pname,lname,strerror(errno));
+        exit(6);
+    }
+    if (write(fd,&cf,sizeof(cf))==-1) {
+        fprintf(stderr,"%s: ERROR: could not write magic in %s (%s)\n",pname,lname,strerror(errno));
+        exit(7);
+    }
+    (void)close(fd);
+    exit(0);
+}
+
+
Index: inetutils-1.6/clog/clog.h
===================================================================
--- /dev/null    1970-01-01 00:00:00.000000000 +0000
+++ inetutils-1.6/clog/clog.h    2011-11-30 10:49:18.769499826 +0200
@@ -0,0 +1,53 @@
+/*-
+ * Copyright (c) 2001
+ *     Jeff Wheelhouse (address@hidden)
+ *
+ * This code was originally developed by Jeff Wheelhouse (address@hidden).
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistribution of source code must retail the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JEFF WHEELHOUSE ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
+ * NO EVENT SHALL JEFF WHEELHOUSE BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
+ * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *  $Id: clog.h,v 1.2 2001/10/02 04:43:52 jdw Exp $
+ */
+
+
+#ifndef _CLOG_H_
+#define _CLOG_H_
+
+/*
+ *  This magic constant is used to identify a valid circular log file.
+ *  syslogd will ignore any circular log file that doesn't have this constant.
+ */
+
+const char MAGIC_CONST[5] = "CLOG";
+
+
+struct clog_footer {
+    uint32_t cf_magic;
+    uint32_t cf_wrap;
+    uint32_t cf_next;
+    uint32_t cf_max;
+    uint32_t cf_lock;
+};
+
+
+#endif  /* _CLOG_H_ */
+   
+
Index: inetutils-1.6/syslogd/syslog.conf.5
===================================================================
--- inetutils-1.6.orig/syslogd/syslog.conf.5    2011-11-30 10:48:56.825498334 +0200
+++ inetutils-1.6/syslogd/syslog.conf.5    2011-11-30 10:49:18.769499826 +0200
@@ -197,6 +197,12 @@
 Selected messages are written to those users
 if they are logged in.
 .It
+A percent sign
+.Pq Dq \&% ,
+followed by a pathname (beginning with a leading slash).  Selected messages
+are written to a circular log file.  See clog(8) for a discussion of
+circular log files.
+.It
 An asterisk.
 Selected messages are written to all logged-in users.
 .El
Index: inetutils-1.6/syslogd/syslogd.c
===================================================================
--- inetutils-1.6.orig/syslogd/syslogd.c    2011-11-30 10:48:56.777498080 +0200
+++ inetutils-1.6/syslogd/syslogd.c    2011-11-30 10:49:18.773499498 +0200
@@ -137,6 +137,7 @@
 #include <progname.h>
 #include <libinetutils.h>
 #include <readutmp.h>
+#include <clog.h>
 
 /* A mask of all facilities mentioned explicitly in the configuration file
  *
@@ -193,6 +194,11 @@
       char *f_hname;
       struct sockaddr_in f_addr;
     } f_forw;            /* Forwarding address.  */
+    struct {
+      char    f_rname[MAXPATHLEN];
+      struct clog_footer *f_footer;
+      size_t  f_size;
+    } f_ring; /* circular file */
     char *f_fname;        /* Name use for Files|Pipes|TTYs.  */
   } f_un;
   char f_prevline[MAXSVLINE];    /* Last message logged.  */
@@ -219,6 +225,7 @@
 #define F_FORW_SUSP    7    /* Suspended host forwarding.  */
 #define F_FORW_UNKN    8    /* Unknown host forwarding.  */
 #define F_PIPE        9    /* Named pipe.  */
+#define F_RING    10   /* ring buffer (circular log) */
 
 const char *TypeNames[] = {
   "UNUSED",
@@ -230,7 +237,8 @@
   "WALL",
   "FORW(SUSPENDED)",
   "FORW(UNKNOWN)",
-  "PIPE"
+  "PIPE",
+  "CLOG"
 };
 
 /* Flags in filed.f_flags.  */
@@ -270,6 +278,8 @@
 void printsys (const char *);
 char *ttymsg (struct iovec *, int, char *, int);
 void wallmsg (struct filed *, struct iovec *);
+ssize_t rbwrite __P((struct filed *, char *, size_t));
+ssize_t rbwritev __P((struct filed *, struct iovec *, int));
 char **crunch_list (char **oldlist, char *list);
 char *textpri (int pri);
 void dbg_toggle (int);
@@ -279,6 +289,7 @@
 static int create_unix_socket (const char *path);
 static int create_inet_socket (void);
 
+
 char *LocalHostName;        /* Our hostname.  */
 char *LocalDomain;        /* Our local domain name.  */
 int finet = -1;            /* Internet datagram socket fd.  */
@@ -1277,6 +1288,21 @@
     }
       break;
 
+    case F_RING:
+      dprintf(" %s\n", f->f_un.f_ring.f_rname);
+      v->iov_base = "\n";
+      v->iov_len = 1;
+      if (rbwritev(f, iov, 7)==-1) {
+        int e = errno;
+        (void)munmap(f->f_un.f_ring.f_footer,sizeof(struct clog_footer));
+        (void)close(f->f_file);
+        f->f_type = F_UNUSED;
+        errno = e;
+        logerror(f->f_un.f_fname);
+      }
+
+    break;
+   
     case F_CONSOLE:
       f->f_time = now;
       if (flags & IGN_CONS)
@@ -1595,6 +1621,10 @@
     case F_PIPE:
       close (f->f_file);
       break;
+  case F_RING:
+    (void)munmap(f->f_un.f_ring.f_footer,sizeof(struct clog_footer));
+    (void)close(f->f_file);
+    break;
     }
       next = f->f_next;
       free (f);
@@ -1736,7 +1766,9 @@
         case F_PIPE:
           dbg_printf ("%s", f->f_un.f_fname);
           break;
-
+      case F_RING:
+        printf("%s", f->f_un.f_ring.f_rname);
+        break;
         case F_FORW:
         case F_FORW_SUSP:
         case F_FORW_UNKN:
@@ -1772,6 +1804,7 @@
   char *bp;
   const char *p, *q;
   char buf[MAXLINE], ebuf[200];
+  struct stat sb;
 
   dbg_printf ("cfline(%s)\n", line);
 
@@ -1953,6 +1986,39 @@
     f->f_type = F_FILE;
       break;
 
+    /* circular log file */
+    case '%':
+      if ((f->f_file = open(p+1, O_RDWR, 0 )) < 0) {
+        f->f_type = F_UNUSED;
+        logerror(p+1);
+        break;
+      }
+      if (fstat(f->f_file,&sb)<0) {
+        (void)close(f->f_file);
+        f->f_type = F_UNUSED;
+        logerror(p+1);
+        break;
+      }
+      f->f_un.f_ring.f_footer = mmap(NULL,sizeof(struct clog_footer),PROT_READ|PROT_WRITE,MAP_SHARED,f->f_file,sb.st_size-sizeof(struct clog_footer));
+      if (f->f_un.f_ring.f_footer==NULL) {
+        (void)close(f->f_file);
+        f->f_type = F_UNUSED;
+        logerror(p+1);
+        break;
+      }
+      if (memcmp(&(f->f_un.f_ring.f_footer->cf_magic),MAGIC_CONST,4)!=0) {
+        (void)munmap(f->f_un.f_ring.f_footer,sizeof(struct clog_footer));
+        (void)close(f->f_file);
+        f->f_type = F_UNUSED;
+        errno = ENODEV;
+        logerror(p+1);
+        break;
+      }
+      f->f_un.f_ring.f_size = sb.st_size;
+      (void)strcpy(f->f_un.f_ring.f_rname, p + 1);
+      f->f_type = F_RING;
+      break;
+
     case '*':
       f->f_type = F_WALL;
       break;
@@ -2042,3 +2108,48 @@
 {
   restart = 1;
 }
+
+/* The following function handles the circular log file access */
+ssize_t rbwritev(struct filed *f, struct iovec *iov, int iovcnt) {
+  int i;
+  ssize_t out = 0;
+  ssize_t err;
+
+  for(i=0;i<iovcnt;i++) {
+    err = rbwrite(f,iov[i].iov_base,iov[i].iov_len);
+    if (err==-1) return -1;
+    out += err;
+  }
+  return out;
+}
+
+
+ssize_t rbwrite(struct filed *f, char *buf, size_t nbytes) {
+  size_t maxwrite = f->f_un.f_ring.f_footer->cf_max - f->f_un.f_ring.f_footer->cf_next;
+  ssize_t err;
+  ssize_t out = 0;
+
+  f->f_un.f_ring.f_footer->cf_lock = 1;
+  while (nbytes>0) {
+    maxwrite = f->f_un.f_ring.f_footer->cf_max - f->f_un.f_ring.f_footer->cf_next;
+    if (maxwrite>nbytes) maxwrite = nbytes;
+    err = pwrite(f->f_file,buf,maxwrite,f->f_un.f_ring.f_footer->cf_next);
+    if (err==-1) {
+      f->f_un.f_ring.f_footer->cf_lock = 0;
+      return -1;
+    }
+    nbytes -= err;
+    out += err;
+    buf += err;
+    f->f_un.f_ring.f_footer->cf_next += err;
+    if (f->f_un.f_ring.f_footer->cf_next==f->f_un.f_ring.f_footer->cf_max) {
+      f->f_un.f_ring.f_footer->cf_next = 0;
+      f->f_un.f_ring.f_footer->cf_wrap = 1;
+    }
+   
+  }
+     
+  f->f_un.f_ring.f_footer->cf_lock = 0;
+  return out;
+}
+