disk.c

snmp的源代码,已经在我的ubuntu下编译通过

   * to the caller 
   */
#if HAVE_FSTAB_H || HAVE_GETMNTENT || HAVE_STATFS   
#if HAVE_GETMNTENT
#if HAVE_SETMNTENT
  mntfp = setmntent(ETC_MNTTAB, "r");
  while (NULL != (mntent = getmntent(mntfp))) {
    add_device(mntent->mnt_dir, mntent->mnt_fsname, -1, minpercent, 0);
    dummy = 1;
  }
  if (mntfp)
    endmntent(mntfp);
  if(dummy != 0) {
    /*
     * dummy clause for else below
     */
  }
#else                           /* getmentent but not setmntent */
  mntfp = fopen(ETC_MNTTAB, "r");
  while ((i = getmntent(mntfp, &mnttab)) == 0) {
    add_device(mnttab.mnt_mountp, mnttab.mnt_special, -1, minpercent, 0);
    dummy = 1;
  }
  fclose(mntfp);
  if(dummy != 0) {
    /*
     * dummy clause for else below
     */
  }
#endif /* HAVE_SETMNTENT */
#elif HAVE_FSTAB_H
  setfsent();			/* open /etc/fstab */
  while((fstab1 = getfsent()) != NULL) {
    add_device(fstab1->fs_file, fstab1->fs_spec, -1, minpercent, 0);
    dummy = 1;
  }
  endfsent();			/* close /etc/fstab */
  if(dummy != 0) {
    /*
     * dummy clause for else below
     */
  }
#elif HAVE_STATFS
  /*
   * since there is no way to get all the mounted systems with just
   * statfs we default to the root partition "/"
   */
  if (statfs("/", &statf) == 0) {
    add_device("/", statf.f_mntfromname, -1, minpercent, 0);
  }
#endif
  else {
    if (numdisks == MAXDISKS) {
      return;
    }
    snprintf(tmpbuf, sizeof(tmpbuf),
             "Couldn't find device for disk %s",
             disks[numdisks].path);
    tmpbuf[ sizeof(tmpbuf)-1 ] = 0;
    config_pwarn(tmpbuf);
    disks[numdisks].minimumspace = -1;
    disks[numdisks].minpercent = -1;
    disks[numdisks].path[0] = 0;
  }
#else
  config_perror("'disk' checks not supported on this architecture.");
#endif                   /* HAVE_FSTAB_H || HAVE_GETMNTENT || HAVE_STATFS */  
 
}

static u_char *
find_device(char *path)
{
#if HAVE_GETMNTENT
#if HAVE_SYS_MNTTAB_H
  struct mnttab   mnttab;
#else
  struct mntent  *mntent;
#endif
  FILE           *mntfp;
#elif HAVE_FSTAB_H
  struct fstab   *fstab;
  struct stat     stat1;
#elif HAVE_STATFS
  struct statfs   statf;
#endif
  char            tmpbuf[1024];
  static char     device[STRMAX];
#if defined(HAVE_GETMNTENT) && !defined(HAVE_SETMNTENT)
  int             i;
#endif

  device[0] = '\0';		/* null terminate the device */


  /* find the device for the path and copy the device into the
   * string declared above and at the end of the routine return it
   * to the caller 
   */
#if HAVE_FSTAB_H || HAVE_GETMNTENT || HAVE_STATFS   
#if HAVE_GETMNTENT
#if HAVE_SETMNTENT
  mntfp = setmntent(ETC_MNTTAB, "r");
  while (NULL != (mntent = getmntent(mntfp)))
    if (strcmp(path, mntent->mnt_dir) == 0) {
      copy_nword(mntent->mnt_fsname, device,
		 sizeof(device));
      DEBUGMSGTL(("ucd-snmp/disk", "Disk:  %s\n",
		  mntent->mnt_fsname));
      break;
    } else {
      DEBUGMSGTL(("ucd-snmp/disk", "  %s != %s\n",
		  path, mntent->mnt_dir));
    }
  if (mntfp)
    endmntent(mntfp);
#else                           /* getmentent but not setmntent */
  mntfp = fopen(ETC_MNTTAB, "r");
  while ((i = getmntent(mntfp, &mnttab)) == 0)
    if (strcmp(path, mnttab.mnt_mountp) == 0)
      break;
    else {
      DEBUGMSGTL(("ucd-snmp/disk", "  %s != %s\n",
		  path, mnttab.mnt_mountp));
    }
  fclose(mntfp);
  if (i == 0) {
    copy_nword(mnttab.mnt_special, device,
	       sizeof(device));
  }
#endif /* HAVE_SETMNTENT */
#elif HAVE_FSTAB_H
  stat(path, &stat1);
  setfsent();
  if ((fstab = getfsfile(path))) {
    copy_nword(fstab->fs_spec, device,
	       sizeof(device));
  }
  endfsent();
  if (device[0] != '\0') {
     /*
      * dummy clause for else below
      */
   }

#elif HAVE_STATFS
  if (statfs(path, &statf) == 0) {
    copy_word(statf.f_mntfromname, device);
    DEBUGMSGTL(("ucd-snmp/disk", "Disk:  %s\n",
		statf.f_mntfromname));
  }
#endif
  else {
    sprintf(tmpbuf, "Couldn't find device for disk %s",
	    path);
    config_pwarn(tmpbuf);
  }
#else
  config_perror("'disk' checks not supported on this architecture.");
#endif                   /* HAVE_FSTAB_H || HAVE_GETMNTENT || HAVE_STATFS */  
  return device;
}


/*
 * var_extensible_disk(...
 * Arguments:
 * vp     IN      - pointer to variable entry that points here
 * name    IN/OUT  - IN/name requested, OUT/name found
 * length  IN/OUT  - length of IN/OUT oid's 
 * exact   IN      - TRUE if an exact match was requested
 * var_len OUT     - length of variable or 0 if function returned
 * write_method
 * 
 */
u_char         *
var_extensible_disk(struct variable *vp,
                    oid * name,
                    size_t * length,
                    int exact,
                    size_t * var_len, WriteMethod ** write_method)
{

    int             percent, iserror, disknum = 0;
#if !defined(HAVE_SYS_STATVFS_H) && !defined(HAVE_STATFS)
    double          totalblks, free, used, avail, availblks;
#else
    static long     avail;
#if defined(STRUCT_STATVFS_HAS_F_FILES) || defined(STRUCT_STATFS_HAS_F_FILES)
    int             percent_inode;
#endif
#endif
    static long     long_ret;
    static char     errmsg[300];
    float           multiplier;

#if defined(HAVE_STATVFS) || defined(HAVE_STATFS)
#ifdef STAT_STATFS_FS_DATA
    struct fs_data  fsd;
    struct {
        u_int           f_blocks, f_bfree, f_bavail, f_bsize;
    } vfs;
#else
    struct statvfs  vfs;
#endif
#else
#if HAVE_FSTAB_H
    int             file;
    union {
        struct fs       iu_fs;
        char            dummy[SBSIZE];
    } sb;
#define filesys sb.iu_fs
#endif
#endif

    if (header_simple_table
        (vp, name, length, exact, var_len, write_method, numdisks))
        return (NULL);
    disknum = name[*length - 1] - 1;
    switch (vp->magic) {
    case MIBINDEX:
        long_ret = disknum + 1;
        return ((u_char *) (&long_ret));
    case ERRORNAME:            /* DISKPATH */
        *var_len = strlen(disks[disknum].path);
        return ((u_char *) disks[disknum].path);
    case DISKDEVICE:
        *var_len = strlen(disks[disknum].device);
        return ((u_char *) disks[disknum].device);
    case DISKMINIMUM:
        long_ret = disks[disknum].minimumspace;
        return ((u_char *) (&long_ret));
    case DISKMINPERCENT:
        long_ret = disks[disknum].minpercent;
        return ((u_char *) (&long_ret));
    }
#if defined(HAVE_STATVFS) || defined(HAVE_STATFS)
#ifdef STAT_STATFS_FS_DATA
    if (statvfs(disks[disknum].path, &fsd) == -1)
#else
    if (statvfs(disks[disknum].path, &vfs) == -1)
#endif
    {
        snmp_log(LOG_ERR, "Couldn't open device %s\n",
                 disks[disknum].device);
        setPerrorstatus("statvfs dev/disk");
        return NULL;
    }
#ifdef STAT_STATFS_FS_DATA
    vfs.f_blocks = fsd.fd_btot;
    vfs.f_bfree = fsd.fd_bfree;
    vfs.f_bavail = fsd.fd_bfreen;
    vfs.f_bsize = 1024;         /*  Ultrix f_bsize is a VM parameter apparently.  */
#endif
#if defined(HAVE_ODS)
    vfs.f_blocks = vfs.f_spare[0];
    vfs.f_bfree = vfs.f_spare[1];
    vfs.f_bavail = vfs.f_spare[2];
#endif
    percent = vfs.f_bavail <= 0 ? 100 :
        (int) ((double) (vfs.f_blocks - vfs.f_bfree) /
               (double) (vfs.f_blocks -
                         (vfs.f_bfree - vfs.f_bavail)) * 100.0 + 0.5);
    multiplier = (float)vfs.f_bsize / (float)1024.0;
#ifdef STRUCT_STATVFS_HAS_F_FRSIZE
    if (vfs.f_frsize > 255)
        multiplier = (float)vfs.f_frsize / (float)1024.0;
#endif
    avail = (long)(vfs.f_bavail * multiplier);
    iserror = (disks[disknum].minimumspace >= 0 ?
               avail < disks[disknum].minimumspace :
               100 - percent <= disks[disknum].minpercent) ? 1 : 0;
#if defined(STRUCT_STATVFS_HAS_F_FILES) || defined STRUCT_STATFS_HAS_F_FAVAIL
    percent_inode = vfs.f_favail <= 0 ? 100 :
        (int) ((double) (vfs.f_files - vfs.f_ffree) /
               (double) (vfs.f_files -
                         (vfs.f_ffree - vfs.f_favail)) * 100.0 + 0.5);
#else
#if defined(STRUCT_STATFS_HAS_F_FILES) && defined(STRUCT_STATFS_HAS_F_FFREE)
   percent_inode = vfs.f_files == 0 ? 100.0 :
      (int) ((double) (vfs.f_files - vfs.f_ffree) /
	          (double) (vfs.f_files) * 100.0 + 0.5);
#endif 
#endif /* defined(STRUCT_STATVFS_HAS_F_FILES) */ 
    switch (vp->magic) {
    case DISKTOTAL:
        long_ret = (long)(vfs.f_blocks * multiplier);
        return ((u_char *) (&long_ret));
    case DISKAVAIL:
        return ((u_char *) (&avail));
    case DISKUSED:
        long_ret = (long)((vfs.f_blocks - vfs.f_bfree) * multiplier);
        return ((u_char *) (&long_ret));
    case DISKPERCENT:
        long_ret = percent;
        return ((u_char *) (&long_ret));
#if defined(STRUCT_STATVFS_HAS_F_FILES) || defined (STRUCT_STATFS_HAS_F_FILES)
    case DISKPERCENTNODE:
        long_ret = percent_inode;
        return ((u_char *) (&long_ret));
#endif
    case ERRORFLAG:
        long_ret = iserror;
        return ((u_char *) (&long_ret));
    case ERRORMSG:
        if (iserror) {
            if (disks[disknum].minimumspace >= 0)
                snprintf(errmsg, sizeof(errmsg),
                        "%s: less than %d free (= %d)",
                        disks[disknum].path, disks[disknum].minimumspace,
                        (int) avail);
            else
                snprintf(errmsg, sizeof(errmsg),
                        "%s: less than %d%% free (= %d%%)",
                        disks[disknum].path, disks[disknum].minpercent,
                        percent);
            errmsg[ sizeof(errmsg)-1 ] = 0;
        } else
            errmsg[0] = 0;
        *var_len = strlen(errmsg);
        return ((u_char *) (errmsg));
    }
#else
#if HAVE_FSTAB_H
    /*
     * read the disk information 
     */
    if ((file = open(disks[disknum].device, 0)) < 0) {
        snmp_log(LOG_ERR, "Couldn't open device %s\n",
                 disks[disknum].device);
        setPerrorstatus("open dev/disk");
        return (NULL);
    }
    lseek(file, (long) (SBLOCK * DEV_BSIZE), 0);
    if (read(file, (char *) &filesys, SBSIZE) != SBSIZE) {
        setPerrorstatus("open dev/disk");
        snmp_log(LOG_ERR, "Error reading device %s\n",
                 disks[disknum].device);
        close(file);
        return (NULL);
    }
    close(file);
    totalblks = filesys.fs_dsize;
    free = filesys.fs_cstotal.cs_nbfree * filesys.fs_frag +
        filesys.fs_cstotal.cs_nffree;
    used = totalblks - free;
    availblks = totalblks * (100 - filesys.fs_minfree) / 100;
    avail = availblks > used ? availblks - used : 0;
    percent =
        availblks ==
        0 ? 100 : (int) ((double) used / (double) totalblks * 100.0 + 0.5);
    multiplier = (float)filesys.fs_fsize / (float)1024.0;
    iserror =
        (disks[disknum].minimumspace >= 0
            ? avail * multiplier < disks[disknum].minimumspace
            : 100 - percent <= disks[disknum].minpercent) ? 1 : 0;
    switch (vp->magic) {
    case DISKTOTAL:
        long_ret = (long)(totalblks * multiplier);
        return ((u_char *) (&long_ret));
    case DISKAVAIL:
        long_ret = (long)(avail * multiplier);
        return ((u_char *) (&long_ret));
    case DISKUSED:
        long_ret = (long)(used * multiplier);
        return ((u_char *) (&long_ret));
    case DISKPERCENT:
        long_ret = percent;
        return ((u_char *) (&long_ret));
    case ERRORFLAG:
        long_ret = iserror;
        return ((u_char *) (&long_ret));
    case ERRORMSG:
        if (iserror) {
            if (disks[disknum].minimumspace >= 0)
                snprintf(errmsg, sizeof(errmsg),
                        "%s: less than %d free (= %d)",
                        disks[disknum].path, disks[disknum].minimumspace,
                        avail * filesys.fs_fsize / 1024);
            else
                snprintf(errmsg, sizeof(errmsg),
                        "%s: less than %d%% free (= %d%%)",
                        disks[disknum].path, disks[disknum].minpercent,
                        percent);
            errmsg[ sizeof(errmsg)-1 ] = 0;
        } else
            errmsg[0] = 0;
        *var_len = strlen(errmsg);
        return ((u_char *) (errmsg));
    }
#endif
#endif
    return NULL;
}