dmsdos-0.9.2.2 addeddmsdos-0.9.2.2

1 files changed, 301 insertions, 0 deletions

diff --git a/src/daemon_actions.c b/src/daemon_actions.c
new file mode 100644
index 0000000..89e15e8
--- /dev/null
+++ b/src/daemon_actions.c
@@ -0,0 +1,301 @@
+/* 
+daemon_actions.c
+
+DMSDOS CVF-FAT module: external dmsdos daemon.
+
+******************************************************************************
+DMSDOS (compressed MSDOS filesystem support) for Linux
+written 1995-1998 by Frank Gockel and Pavel Pisa
+
+    (C) Copyright 1995-1998 by Frank Gockel
+    (C) Copyright 1996-1998 by Pavel Pisa
+
+Some code of dmsdos has been copied from the msdos filesystem
+so there are the following additional copyrights:
+
+    (C) Copyright 1992,1993 by Werner Almesberger (msdos filesystem)
+    (C) Copyright 1994,1995 by Jacques Gelinas (mmap code)
+    (C) Copyright 1992-1995 by Linus Torvalds
+
+DMSDOS was inspired by the THS filesystem (a simple doublespace
+DS-0-2 compressed read-only filesystem) written 1994 by Thomas Scheuermann.
+
+The DMSDOS code is distributed under the Gnu General Public Licence.
+See file COPYING for details.
+******************************************************************************
+
+*/
+
+#include<stdio.h>
+#include "dmsdos.h"
+#include<sys/ioctl.h>
+#include<sys/types.h>
+#include<sys/stat.h>
+#include<fcntl.h>
+#include<string.h>
+#include<errno.h>
+#include<signal.h>
+#include<unistd.h>
+
+/* default compression level minus 1 for dmsdosd */
+int cfaktor=11;
+
+int debug=0;
+
+int exit_signaled=0;
+
+#define CONTINUE 0
+#define EXIT_AND_FINISH 1
+#define EXIT_IMMEDIATELY 2
+
+/* time to sleep between two idle calls (in seconds) 
+   for slower systems you can use a higher value in order to reduce 
+   unnecessary polling */
+#define SLEEPTIME 30
+
+#define PIDFILE "/var/run/dmsdosd.pid"
+
+typedef struct
+{ long val1;
+  long val2;
+  long val3;
+  unsigned char data[32*1024];
+} Cdata;
+
+Cdata cdata;
+Cdata ckdata;
+
+void signal_handler(int a)
+{ if(a==SIGINT)exit_signaled=EXIT_AND_FINISH;
+  if(a==SIGTERM)exit_signaled=EXIT_IMMEDIATELY;
+  /* reactivate again */
+  signal(SIGINT,signal_handler);
+  signal(SIGTERM,signal_handler);
+  signal(SIGUSR1,signal_handler); /* this should just wake up */
+}
+
+void pidfile(void)
+{ struct stat buf;
+  int pid=0;
+  char str[100];
+  FILE*f;
+
+  if(stat(PIDFILE,&buf)>=0)
+  { if(debug)fprintf(stderr,"pidfile exists");
+    f=fopen(PIDFILE,"r");
+    if(f)
+    { fscanf(f,"%d",&pid);
+      fclose(f);
+      sprintf(str,"/proc/%d/stat",pid);
+      if(stat(str,&buf)>=0)
+      { fprintf(stderr,"dmsdosd already running\n");
+        exit(1);
+      }
+    }
+    unlink(PIDFILE);
+  }
+
+  f=fopen(PIDFILE,"w");
+  if(f==NULL)
+  { fprintf(stderr,"cannot write pidfile %s\n",PIDFILE);
+    exit(1);
+  }
+  fprintf(f,"%d\n",getpid());
+  fclose(f);
+}
+
+#include <stdarg.h>
+int printk(const char *fmt, ...)
+{ va_list ap;
+  char buf[500];
+  char*p=buf;
+  int i;
+
+  va_start(ap, fmt);
+  i=vsnprintf(buf, 500, fmt, ap);
+  va_end(ap);
+
+  if(p[0]=='<'&&p[1]>='0'&&p[1]<='7'&&p[2]=='>')p+=3;
+  if(strncmp(p,"DMSDOS: ",8)==0)p+=8;
+  
+  fprintf(stderr,"dmsdosd: %s",p);
+
+  return i;
+}
+
+int errm=0;
+
+int get_and_compress_one(int fd)
+{ int ret;
+  int handle;
+  int length;
+  int size;
+  int method;
+  
+  /* get cluster to compress */
+  if(exit_signaled!=CONTINUE)return 2;
+  if(debug)fprintf(stderr,"dmsdosd: Trying to read...\n");
+  ret=ioctl(fd,DMSDOS_D_READ,&cdata);
+  if(ret!=1)
+  { if(debug)fprintf(stderr,"dmsdosd: nothing there - D_READ ioctl returned %d\n",ret);
+    return ret;
+  }
+  
+  handle=cdata.val1;
+  length=cdata.val2;
+  size=(length-1)/512+1;
+  method=cdata.val3;
+  if(debug)fprintf(stderr,"dmsdosd: compressing...\n");
+  
+  if(method==SD_3||method==SD_4)
+  {
+#ifdef DMSDOS_CONFIG_STAC
+    ret=stac_compress(cdata.data,length,ckdata.data,
+                     sizeof(ckdata.data),method,cfaktor);
+#else
+    if(errm==0)
+    { errm=1;
+      fprintf(stderr,"dmsdosd: stacker compression requested, but not compiled in!\n");
+    }  
+    ret=-1;
+#endif
+  }
+  else
+    ret=dbl_compress(ckdata.data,cdata.data,size,method,cfaktor)*512;
+  
+  if(debug)fprintf(stderr,"dmsdosd: compress %X from %d returned %d\n",
+                  method,length,ret);
+  if(ret<0)ret=0; /* compression failed */
+  ckdata.val1=handle;
+  ckdata.val2=ret;
+  if(debug)fprintf(stderr,"dmsdosd: writing...\n");
+  ioctl(fd,DMSDOS_D_WRITE,&ckdata);
+  
+  return 1; /* one cluster compressed */
+}
+
+void do_dmsdosd_actions(int fd)
+{
+  /* register dmsdosd */
+  if(debug)fprintf(stderr,"dmsdosd: calling D_ASK...\n");
+  if(ioctl(fd,DMSDOS_D_ASK,getpid()))
+  { fprintf(stderr,"dmsdosd: can't get permissions (internal daemon running?)\n");
+    return;
+  }
+  
+  signal(SIGINT,signal_handler);
+  signal(SIGTERM,signal_handler);
+  signal(SIGUSR1,signal_handler); /* this should just wake up */
+
+  do
+  { while(get_and_compress_one(fd)==1);
+    /* don't kill the system performance when nothing to compress */
+    if(exit_signaled==CONTINUE)
+    { if(debug)fprintf(stderr,"dmsdosd: sleeping...\n"); 
+      sleep(SLEEPTIME);
+      /* throw away long idle mdfat/dfat/bitfat sectors */
+      ioctl(fd,DMSDOS_FREE_IDLE_CACHE,NULL);
+    }
+  }
+  while(exit_signaled==CONTINUE);  
+  
+  if(debug)fprintf(stderr,"dmsdosd: calling D_EXIT...\n");
+  ioctl(fd,DMSDOS_D_EXIT,NULL);
+  
+  if(exit_signaled==EXIT_AND_FINISH)
+  { exit_signaled=CONTINUE;
+    while(get_and_compress_one(fd)==1);
+  }
+  
+}
+
+int scan(char*arg)
+{ int w;
+
+  if(strncmp(arg,"0x",2)==0)sscanf(arg+2,"%x",&w);
+  else sscanf(arg,"%d",&w);
+  
+  return w;
+}
+
+int main(int argc, char*argv[])
+{ Dblsb dblsb;
+  int fd;
+  int ret;
+  
+  if(argc<2||argc>4)
+  {
+    fprintf(stderr,"DMSDOS daemon (C) 1996-1998 Frank Gockel, Pavel Pisa\n");
+    fprintf(stderr,"compiled " __DATE__ " " __TIME__ " under dmsdos version %d.%d.%d%s\n\n",
+           DMSDOS_MAJOR,DMSDOS_MINOR,DMSDOS_ACT_REL,DMSDOS_VLT);
+    fprintf(stderr,"Usage: %s (directory)\n",argv[0]);
+    fprintf(stderr,"       %s (directory) cf\n",argv[0]);
+    fprintf(stderr,"       %s (directory) cf debug\n",argv[0]);
+    return 1;
+  }
+
+  if(getuid())
+  { fprintf(stderr,"Sorry, you must be root to run me.\n");
+    exit(1);
+  }
+  
+  if(argc==4)debug=1;
+  
+  fd=open(argv[1],O_RDONLY);
+  if(fd<0)
+  { perror("open");
+    return 1;
+  }
+  
+  if(argc==3)
+  { cfaktor=scan(argv[2])-1;
+    if(cfaktor<0||cfaktor>11)
+    { fprintf(stderr,"cf parameter out of range\n");
+      close(fd);
+      return 1;
+    }
+  }
+
+  /* this hack enables reverse version check */
+  /* it must not be changed in order to recognize incompatible older versions */
+  /* this also depends on s_dcluster being the first record in Dblsb */
+  dblsb.s_dcluster=DMSDOS_VERSION;
+  
+  ret=ioctl(fd,DMSDOS_GET_DBLSB,&dblsb);
+  if(ret<0)
+  { printf("This is not a DMSDOS directory.\n");
+    close(fd);
+    return 1;
+  }
+  if(ret!=DMSDOS_VERSION)printf("You are running DMSDOS driver version %d.%d.%d.\n",(ret&0xff0000)>>16,
+         (ret&0x00ff00)>>8,ret&0xff);
+  /*printf("debug: ret=0x%08x\n",ret);*/
+  if(ret!=DMSDOS_VERSION)printf("This program was compiled for DMSDOS version %d.%d.%d",
+         (DMSDOS_VERSION&0xff0000)>>16,(DMSDOS_VERSION&0x00ff00)>>8,DMSDOS_VERSION&0xff);        
+  if(ret&0x0f000000)
+  { printf("\nSorry, this program is too old for the actual DMSDOS driver version.\n");
+    close(fd);
+    return 1;
+  }
+  if(ret<0x00000902)
+  { printf("\nSorry, this program requires at least DMSDOS driver version 0.9.2.\n");
+    close(fd);
+    return 1;
+  }
+  if(ret!=DMSDOS_VERSION)printf(" but should still work.\n\n");
+
+
+  if(!debug)
+  { if(fork())exit(0);
+  }
+
+  pidfile();
+
+  do_dmsdosd_actions(fd);
+  
+  close(fd);
+
+  unlink(PIDFILE);
+
+  return 0;
+}