/*
   Copyright (C) 2000-2005 Kern Sibbald

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   version 2 as amended with additional clauses defined in the
   file LICENSE in the main source directory.

   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 
   the file LICENSE for additional details.

 */

/*

   This file is based on GNU TAR source code. Except for a few key
   ideas, it has been entirely rewritten for Bacula.

      Kern Sibbald, MM

   Thanks to the TAR programmers.

     Version $Id: find_one.c,v 1.49.2.1 2005/12/10 13:18:03 kerns Exp $

 */

#include "bacula.h"
#include "find.h"
#ifdef HAVE_DARWIN_OS
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/attr.h>
#endif

extern int32_t name_max;              /* filename max length */
extern int32_t path_max;              /* path name max length */

/*
 * Structure for keeping track of hard linked files, we
 *   keep an entry for each hardlinked file that we save,
 *   which is the first one found. For all the other files that
 *   are linked to this one, we save only the directory
 *   entry so we can link it.
 */
struct f_link {
    struct f_link *next;
    dev_t dev;                        /* device */
    ino_t ino;                        /* inode with device is unique */
    short linkcount;
    uint32_t FileIndex;               /* Bacula FileIndex of this file */
    char name[1];                     /* The name */
};

static void free_dir_ff_pkt(FF_PKT *dir_ff_pkt)
{
   free(dir_ff_pkt->fname);
   free(dir_ff_pkt->link);
   free_pool_memory(dir_ff_pkt->sys_fname);
   free(dir_ff_pkt);
}

/*
 * Check to see if we allow the file system type of a file or directory.
 * If we do not have a list of file system types, we accept anything.
 */
static int accept_fstype(FF_PKT *ff, void *dummy) {
   int i;
   char fs[1000];
   bool accept = true;

   if (ff->fstypes.size()) {
      accept = false;
      if (!fstype(ff->fname, fs, sizeof(fs))) {
         Dmsg1(50, "Cannot determine file system type for \"%s\"\n", ff->fname);
      } else {
         for (i = 0; i < ff->fstypes.size(); ++i) {
            if (strcmp(fs, (char *)ff->fstypes.get(i)) == 0) {
               Dmsg2(100, "Accepting fstype %s for \"%s\"\n", fs, ff->fname);
               accept = true;
               break;
            }
            Dmsg3(200, "fstype %s for \"%s\" does not match %s\n", fs,
                  ff->fname, ff->fstypes.get(i));
         }
      }
   }
   return accept;
}

/*
 * This function determines whether we can use getattrlist()
 * It's odd, but we have to use the function to determine that...
 * Also, the man pages talk about things as if they were implemented.
 *
 * On Mac OS X, this succesfully differentiates between HFS+ and UFS
 * volumes, which makes me trust it is OK for others, too.
 */
static bool volume_has_attrlist(const char *fname)
{
#ifdef HAVE_DARWIN_OS
   struct statfs st;
   struct volinfo_struct {
      unsigned long length;               /* Mandatory field */
      vol_capabilities_attr_t info;       /* Volume capabilities */
   } vol;
   struct attrlist attrList;

   memset(&attrList, 0, sizeof(attrList));
   attrList.bitmapcount = ATTR_BIT_MAP_COUNT;
   attrList.volattr = ATTR_VOL_INFO | ATTR_VOL_CAPABILITIES;
   if (statfs(fname, &st) == 0) {
      /* We need to check on the mount point */
      if (getattrlist(st.f_mntonname, &attrList, &vol, sizeof(vol), FSOPT_NOFOLLOW) == 0
            && (vol.info.capabilities[VOL_CAPABILITIES_INTERFACES] & VOL_CAP_INT_ATTRLIST)
            && (vol.info.valid[VOL_CAPABILITIES_INTERFACES] & VOL_CAP_INT_ATTRLIST)) {
         return true;
      }
   }
#endif
   return false;
}

/*
 * Find a single file.
 * handle_file is the callback for handling the file.
 * p is the filename
 * parent_device is the device we are currently on
 * top_level is 1 when not recursing or 0 when
 *  descending into a directory.
 */
int
find_one_file(JCR *jcr, FF_PKT *ff_pkt, 
               int handle_file(FF_PKT *ff, void *hpkt, bool top_level),
               void *pkt, char *fname, dev_t parent_device, bool top_level)
{
   struct utimbuf restore_times;
   int rtn_stat;
   int len;

   ff_pkt->fname = ff_pkt->link = fname;

   if (lstat(fname, &ff_pkt->statp) != 0) {
       /* Cannot stat file */
       ff_pkt->type = FT_NOSTAT;
       ff_pkt->ff_errno = errno;
       return handle_file(ff_pkt, pkt, top_level);
   }

   Dmsg1(300, "File ----: %s\n", fname);

   /* Save current times of this directory in case we need to
    * reset them because the user doesn't want them changed.
    */
   restore_times.actime = ff_pkt->statp.st_atime;
   restore_times.modtime = ff_pkt->statp.st_mtime;

   /*
    * We check for allowed fstypes at top_level and fstype change (below).
    */
   if (top_level) {
      if (!accept_fstype(ff_pkt, NULL)) {
         ff_pkt->type = FT_INVALIDFS;
         if (ff_pkt->flags & FO_KEEPATIME) {
            utime(fname, &restore_times);
         }
         Jmsg1(jcr, M_ERROR, 0, _("Top level directory \"%s\" has an unlisted fstype\n"), fname);
         return 1;      /* Just ignore this error - or the whole backup is cancelled */
      }
      ff_pkt->volhas_attrlist = volume_has_attrlist(fname);
   }

   /*
    * If this is an Incremental backup, see if file was modified
    * since our last "save_time", presumably the last Full save
    * or Incremental.
    */
   if (ff_pkt->incremental && !S_ISDIR(ff_pkt->statp.st_mode)) {
      Dmsg1(300, "Non-directory incremental: %s\n", ff_pkt->fname);
      /* Not a directory */
      if (ff_pkt->statp.st_mtime < ff_pkt->save_time
          && ((ff_pkt->flags & FO_MTIMEONLY) ||
              ff_pkt->statp.st_ctime < ff_pkt->save_time)) {
         /* Incremental option, file not changed */
         ff_pkt->type = FT_NOCHG;
         return handle_file(ff_pkt, pkt, top_level);
      }
   }

#ifdef HAVE_DARWIN_OS
   if (ff_pkt->flags & FO_HFSPLUS && ff_pkt->volhas_attrlist
         && S_ISREG(ff_pkt->statp.st_mode)) {
       /* TODO: initialise attrList once elsewhere? */
       struct attrlist attrList;
       memset(&attrList, 0, sizeof(attrList));
       attrList.bitmapcount = ATTR_BIT_MAP_COUNT;
       attrList.commonattr = ATTR_CMN_FNDRINFO;
       attrList.fileattr = ATTR_FILE_RSRCLENGTH;
       if (getattrlist(fname, &attrList, &ff_pkt->hfsinfo,
                sizeof(ff_pkt->hfsinfo), FSOPT_NOFOLLOW) != 0) {
          ff_pkt->type = FT_NOSTAT;
          ff_pkt->ff_errno = errno;
          return handle_file(ff_pkt, pkt, top_level);
       }
   }
#endif

/* ***FIXME*** implement this */
#if xxxxxxx
   /* See if we are trying to dump the archive.  */
   if (ar_dev && ff_pkt->statp.st_dev == ar_dev && ff_pkt->statp.st_ino == ar_ino) {
       ff_pkt->type = FT_ISARCH;
       return handle_file(ff_pkt, pkt, top_level);
   }
#endif
   ff_pkt->LinkFI = 0;
   /*
    * Handle hard linked files
    *
    * Maintain a list of hard linked files already backed up. This
    *  allows us to ensure that the data of each file gets backed
    *  up only once.
    */
   if (!(ff_pkt->flags & FO_NO_HARDLINK)
       && ff_pkt->statp.st_nlink > 1
       && (S_ISREG(ff_pkt->statp.st_mode)
           || S_ISCHR(ff_pkt->statp.st_mode)
           || S_ISBLK(ff_pkt->statp.st_mode)
           || S_ISFIFO(ff_pkt->statp.st_mode)
           || S_ISSOCK(ff_pkt->statp.st_mode))) {

       struct f_link *lp;

      /* Search link list of hard linked files */
      for (lp = ff_pkt->linklist; lp; lp = lp->next)
         if (lp->ino == (ino_t)ff_pkt->statp.st_ino &&
             lp->dev == (dev_t)ff_pkt->statp.st_dev) {
             /* If we have already backed up the hard linked file don't do it again */
             if (strcmp(lp->name, fname) == 0) {
                return 1;             /* ignore */
             }
             ff_pkt->link = lp->name;
             ff_pkt->type = FT_LNKSAVED;       /* Handle link, file already saved */
             ff_pkt->LinkFI = lp->FileIndex;
             return handle_file(ff_pkt, pkt, top_level);
         }

      /* File not previously dumped. Chain it into our list. */
      len = strlen(fname) + 1;
      lp = (struct f_link *)bmalloc(sizeof(struct f_link) + len);
      lp->ino = ff_pkt->statp.st_ino;
      lp->dev = ff_pkt->statp.st_dev;
      bstrncpy(lp->name, fname, len);
      lp->next = ff_pkt->linklist;
      ff_pkt->linklist = lp;
      ff_pkt->linked = lp;            /* mark saved link */
   } else {
      ff_pkt->linked = NULL;
   }

   /* This is not a link to a previously dumped file, so dump it.  */
   if (S_ISREG(ff_pkt->statp.st_mode)) {
      off_t sizeleft;

      sizeleft = ff_pkt->statp.st_size;

      /* Don't bother opening empty, world readable files.  Also do not open
         files when archive is meant for /dev/null.  */
      if (ff_pkt->null_output_device || (sizeleft == 0
              && MODE_RALL == (MODE_RALL & ff_pkt->statp.st_mode))) {
         ff_pkt->type = FT_REGE;
      } else {
         ff_pkt->type = FT_REG;
      }
      rtn_stat = handle_file(ff_pkt, pkt, top_level);
      if (ff_pkt->linked) {
         ff_pkt->linked->FileIndex = ff_pkt->FileIndex;
      }
      if (ff_pkt->flags & FO_KEEPATIME) {
         utime(fname, &restore_times);
      }       
      return rtn_stat;


   } else if (S_ISLNK(ff_pkt->statp.st_mode)) {  /* soft link */
      int size;
      char *buffer = (char *)alloca(path_max + name_max + 102);

      size = readlink(fname, buffer, path_max + name_max + 101);
      if (size < 0) {
         /* Could not follow link */
         ff_pkt->type = FT_NOFOLLOW;
         ff_pkt->ff_errno = errno;
         rtn_stat = handle_file(ff_pkt, pkt, top_level);
         if (ff_pkt->linked) {
            ff_pkt->linked->FileIndex = ff_pkt->FileIndex;
         }
         return rtn_stat;
      }
      buffer[size] = 0;
      ff_pkt->link = buffer;          /* point to link */
      ff_pkt->type = FT_LNK;          /* got a real link */
      rtn_stat = handle_file(ff_pkt, pkt, top_level);
      if (ff_pkt->linked) {
         ff_pkt->linked->FileIndex = ff_pkt->FileIndex;
      }
      return rtn_stat;

   } else if (S_ISDIR(ff_pkt->statp.st_mode)) {
      DIR *directory;
      struct dirent *entry, *result;
      char *link;
      int link_len;
      int len;
      int status;
      dev_t our_device = ff_pkt->statp.st_dev;
      bool recurse = true;
      bool volhas_attrlist = ff_pkt->volhas_attrlist;    /* Remember this if we recurse */

      /*
       * If we are using Win32 (non-portable) backup API, don't check
       *  access as everything is more complicated, and
       *  in principle, we should be able to access everything.
       */
      if (!have_win32_api() || (ff_pkt->flags & FO_PORTABLE)) {
         if (access(fname, R_OK) == -1 && geteuid() != 0) {
            /* Could not access() directory */
            ff_pkt->type = FT_NOACCESS;
            ff_pkt->ff_errno = errno;
            rtn_stat = handle_file(ff_pkt, pkt, top_level);
            if (ff_pkt->linked) {
               ff_pkt->linked->FileIndex = ff_pkt->FileIndex;
            }
            return rtn_stat;
         }
      }

      /* Build a canonical directory name with a trailing slash in link var */
      len = strlen(fname);
      link_len = len + 200;
      link = (char *)bmalloc(link_len + 2);
      bstrncpy(link, fname, link_len);
      /* Strip all trailing slashes */
      while (len >= 1 && link[len - 1] == '/')
        len--;
      link[len++] = '/';             /* add back one */
      link[len] = 0;

      ff_pkt->link = link;
      if (ff_pkt->incremental &&
          (ff_pkt->statp.st_mtime < ff_pkt->save_time &&
             ((ff_pkt->flags & FO_MTIMEONLY) ||
               ff_pkt->statp.st_ctime < ff_pkt->save_time))) {
         /* Incremental option, directory entry not changed */
         ff_pkt->type = FT_DIRNOCHG;
      } else {
         ff_pkt->type = FT_DIRBEGIN;
      }
      /*
       * Note, we return the directory to the calling program (handle_file)
       * when we first see the directory (FT_DIRBEGIN.
       * This allows the program to apply matches and make a
       * choice whether or not to accept it.  If it is accepted, we
       * do not immediately save it, but do so only after everything
       * in the directory is seen (i.e. the FT_DIREND).
       */
      rtn_stat = handle_file(ff_pkt, pkt, top_level);
      if (rtn_stat < 1) {             /* ignore or error status */
         free(link);
         return rtn_stat;
      }
      /* Done with DIRBEGIN, next call will be DIREND */
      if (ff_pkt->type == FT_DIRBEGIN) {
         ff_pkt->type = FT_DIREND;
      }

      /*
       * Create a temporary ff packet for this directory
       *   entry, and defer handling the directory until
       *   we have recursed into it.  This saves the
       *   directory after all files have been processed, and
       *   during the restore, the directory permissions will
       *   be reset after all the files have been restored.
       */
      Dmsg1(300, "Create temp ff packet for dir: %s\n", ff_pkt->fname);
      FF_PKT *dir_ff_pkt = (FF_PKT *)bmalloc(sizeof(FF_PKT));
      memcpy(dir_ff_pkt, ff_pkt, sizeof(FF_PKT));
      dir_ff_pkt->fname = bstrdup(ff_pkt->fname);
      dir_ff_pkt->link = bstrdup(ff_pkt->link);
      dir_ff_pkt->sys_fname = get_pool_memory(PM_FNAME);
      dir_ff_pkt->included_files_list = NULL;
      dir_ff_pkt->excluded_files_list = NULL;
      dir_ff_pkt->excluded_paths_list = NULL;
      dir_ff_pkt->linklist = NULL;

      /*
       * Do not descend into subdirectories (recurse) if the
       * user has turned it off for this directory.
       *
       * If we are crossing file systems, we are either not allowed
       * to cross, or we may be restricted by a list of permitted
       * file systems.
       */
      if (!top_level && ff_pkt->flags & FO_NO_RECURSION) {
         ff_pkt->type = FT_NORECURSE;
         recurse = false;
      } else if (!top_level && parent_device != ff_pkt->statp.st_dev) {
         if(!(ff_pkt->flags & FO_MULTIFS)) {
            ff_pkt->type = FT_NOFSCHG;
            recurse = false;
         } else if (!accept_fstype(ff_pkt, NULL)) {
            ff_pkt->type = FT_INVALIDFS;
            recurse = false;
         } else {
            ff_pkt->volhas_attrlist = volume_has_attrlist(fname);
         }
      }
      /* If not recursing, just backup dir and return */
      if (!recurse) {
         rtn_stat = handle_file(ff_pkt, pkt, top_level);
         if (ff_pkt->linked) {
            ff_pkt->linked->FileIndex = ff_pkt->FileIndex;
         }
         free(link);
         free_dir_ff_pkt(dir_ff_pkt);
         ff_pkt->link = ff_pkt->fname;     /* reset "link" */
         if (ff_pkt->flags & FO_KEEPATIME) {
            utime(fname, &restore_times);
         }
         return rtn_stat;
      }

      ff_pkt->link = ff_pkt->fname;     /* reset "link" */

      /*
       * Descend into or "recurse" into the directory to read
       *   all the files in it.
       */
      errno = 0;
      if ((directory = opendir(fname)) == NULL) {
         ff_pkt->type = FT_NOOPEN;
         ff_pkt->ff_errno = errno;
         rtn_stat = handle_file(ff_pkt, pkt, top_level);
         if (ff_pkt->linked) {
            ff_pkt->linked->FileIndex = ff_pkt->FileIndex;
         }
         free(link);
         free_dir_ff_pkt(dir_ff_pkt);
         return rtn_stat;
      }

      /*
       * Process all files in this directory entry (recursing).
       *    This would possibly run faster if we chdir to the directory
       *    before traversing it.
       */
      rtn_stat = 1;
      entry = (struct dirent *)malloc(sizeof(struct dirent) + name_max + 100);
      for ( ; !job_canceled(jcr); ) {
         char *p, *q;
         int i;

         status  = readdir_r(directory, entry, &result);
         if (status != 0 || result == NULL) {
//          Dmsg2(99, "readdir returned stat=%d result=0x%x\n",
//             status, (long)result);
            break;
         }
         ASSERT(name_max+1 > (int)sizeof(struct dirent) + (int)NAMELEN(entry));
         p = entry->d_name;
         /* Skip `.', `..', and excluded file names.  */
         if (p[0] == '\0' || (p[0] == '.' && (p[1] == '\0' ||
             (p[1] == '.' && p[2] == '\0')))) {
            continue;
         }

         if ((int)NAMELEN(entry) + len >= link_len) {
             link_len = len + NAMELEN(entry) + 1;
             link = (char *)brealloc(link, link_len + 1);
         }
         q = link + len;
         for (i=0; i < (int)NAMELEN(entry); i++) {
            *q++ = *p++;
         }
         *q = 0;
         if (!file_is_excluded(ff_pkt, link)) {
            rtn_stat = find_one_file(jcr, ff_pkt, handle_file, pkt, link, our_device, false);
            if (ff_pkt->linked) {
               ff_pkt->linked->FileIndex = ff_pkt->FileIndex;
            }
         }
      }
      closedir(directory);
      free(link);
      free(entry);

      /*
       * Now that we have recursed through all the files in the
       *  directory, we "save" the directory so that after all
       *  the files are restored, this entry will serve to reset
       *  the directory modes and dates.  Temp directory values
       *  were used without this record.
       */
      handle_file(dir_ff_pkt, pkt, top_level);       /* handle directory entry */
      if (ff_pkt->linked) {
         ff_pkt->linked->FileIndex = dir_ff_pkt->FileIndex;
      }
      free_dir_ff_pkt(dir_ff_pkt);

      if (ff_pkt->flags & FO_KEEPATIME) {
         utime(fname, &restore_times);
      }
      ff_pkt->volhas_attrlist = volhas_attrlist;      /* Restore value in case it changed. */
      return rtn_stat;
   } /* end check for directory */

   /*
    * If it is explicitly mentioned (i.e. top_level) and is
    *  a block device, we do a raw backup of it or if it is
    *  a fifo, we simply read it.
    */
#ifdef HAVE_FREEBSD_OS
   /*
    * On FreeBSD, all block devices are character devices, so
    *   to be able to read a raw disk, we need the check for
    *   a character device.
    * crw-r-----  1 root  operator  - 116, 0x00040002 Jun  9 19:32 /dev/ad0s3
    * crw-r-----  1 root  operator  - 116, 0x00040002 Jun  9 19:32 /dev/rad0s3
    */
   if (top_level && (S_ISBLK(ff_pkt->statp.st_mode) || S_ISCHR(ff_pkt->statp.st_mode))) {
#else
   if (top_level && S_ISBLK(ff_pkt->statp.st_mode)) {
#endif
      ff_pkt->type = FT_RAW;          /* raw partition */
   } else if (top_level && S_ISFIFO(ff_pkt->statp.st_mode) &&
              ff_pkt->flags & FO_READFIFO) {
      ff_pkt->type = FT_FIFO;
   } else {
      /* The only remaining types are special (character, ...) files */
      ff_pkt->type = FT_SPEC;
   }
   rtn_stat = handle_file(ff_pkt, pkt, top_level);
   if (ff_pkt->linked) {
      ff_pkt->linked->FileIndex = ff_pkt->FileIndex;
   }
   return rtn_stat;
}

int term_find_one(FF_PKT *ff)
{
   struct f_link *lp, *lc;
   int count = 0;

   /* Free up list of hard linked files */
   for (lp = ff->linklist; lp;) {
      lc = lp;
      lp = lp->next;
      if (lc) {
         free(lc);
         count++;
      }
   }
   ff->linklist = NULL;
   return count;
}
