コード例 #1
0
ファイル: help.c プロジェクト: CharizTeam/dpkg
/*
 * Returns true if the file is used by packages other than pkg,
 * false otherwise.
 */
bool
dir_is_used_by_others(struct filenamenode *file, struct pkginfo *pkg)
{
  struct filepackages_iterator *iter;
  struct pkginfo *other_pkg;

  debug(dbg_veryverbose, "dir_is_used_by_others '%s' (except %s)", file->name,
        pkg ? pkg_name(pkg, pnaw_always) : "<none>");

  iter = filepackages_iter_new(file);
  while ((other_pkg = filepackages_iter_next(iter))) {
    debug(dbg_veryverbose, "dir_is_used_by_others considering %s ...",
          pkg_name(other_pkg, pnaw_always));
    if (other_pkg == pkg)
      continue;

    filepackages_iter_free(iter);
    debug(dbg_veryverbose, "dir_is_used_by_others yes");
    return true;
  }
  filepackages_iter_free(iter);

  debug(dbg_veryverbose, "dir_is_used_by_others no");
  return false;
}
コード例 #2
0
ファイル: archives.c プロジェクト: Minipig/dpkg
/**
 * Check if a file or directory will save a package from disappearance.
 *
 * A package can only be saved by a file or directory which is part
 * only of itself - it must be neither part of the new package being
 * installed nor part of any 3rd package (this is important so that
 * shared directories don't stop packages from disappearing).
 */
bool
filesavespackage(struct fileinlist *file,
                 struct pkginfo *pkgtobesaved,
                 struct pkginfo *pkgbeinginstalled)
{
  struct filepackages_iterator *iter;
  struct pkginfo *divpkg, *thirdpkg;

  debug(dbg_eachfiledetail,"filesavespackage file `%s' package %s",
        file->namenode->name,pkgtobesaved->name);

  /* If the file is a contended one and it's overridden by either
   * the package we're considering disappearing or the package
   * we're installing then they're not actually the same file, so
   * we can't disappear the package - it is saved by this file. */
  if (file->namenode->divert && file->namenode->divert->useinstead) {
    divpkg= file->namenode->divert->pkg;
    if (divpkg == pkgtobesaved || divpkg == pkgbeinginstalled) {
      debug(dbg_eachfiledetail,"filesavespackage ... diverted -- save!");
      return true;
    }
  }
  /* Is the file in the package being installed? If so then it can't save. */
  if (file->namenode->flags & fnnf_new_inarchive) {
    debug(dbg_eachfiledetail,"filesavespackage ... in new archive -- no save");
    return false;
  }
  /* Look for a 3rd package which can take over the file (in case
   * it's a directory which is shared by many packages. */
  iter = filepackages_iter_new(file->namenode);
  while ((thirdpkg = filepackages_iter_next(iter))) {
    debug(dbg_eachfiledetail, "filesavespackage ... also in %s",
          thirdpkg->name);

    /* Is this not the package being installed or the one being
     * checked for disappearance? */
    if (thirdpkg == pkgbeinginstalled || thirdpkg == pkgtobesaved)
      continue;

    /* If !fileslistvalid then we've already disappeared this one, so
     * we shouldn't try to make it take over this shared directory. */
    debug(dbg_eachfiledetail,"filesavespackage ...  is 3rd package");

    if (!thirdpkg->clientdata->fileslistvalid) {
      debug(dbg_eachfiledetail, "process_archive ... already disappeared!");
      continue;
    }

    /* We've found a package that can take this file. */
    debug(dbg_eachfiledetail, "filesavespackage ...  taken -- no save");
    return false;
  }
  filepackages_iter_free(iter);

  debug(dbg_eachfiledetail, "filesavespackage ... not taken -- save !");
  return true;
}
コード例 #3
0
void process_archive(const char *filename) {
  static const struct tar_operations tf = {
    .read = tarfileread,
    .extract_file = tarobject,
    .link = tarobject,
    .symlink = tarobject,
    .mkdir = tarobject,
    .mknod = tarobject,
  };

  /* These need to be static so that we can pass their addresses to
   * push_cleanup as arguments to the cu_xxx routines; if an error occurs
   * we unwind the stack before processing the cleanup list, and these
   * variables had better still exist ... */
  static int p1[2];
  static char *cidir = NULL;
  static struct fileinlist *newconffiles, *newfileslist;
  static enum pkgstatus oldversionstatus;
  static struct varbuf depprobwhy;
  static struct tarcontext tc;

  int r, i;
  pid_t pid;
  struct pkgiterator *it;
  struct pkginfo *pkg, *otherpkg;
  char *cidirrest, *p;
  char conffilenamebuf[MAXCONFFILENAME];
  char *psize;
  const char *pfilename;
  struct fileinlist *newconff, **newconffileslastp;
  struct fileinlist *cfile;
  struct reversefilelistiter rlistit;
  struct conffile *searchconff, **iconffileslastp, *newiconff;
  struct dependency *dsearch, *newdeplist, **newdeplistlastp;
  struct dependency *newdep, *dep, *providecheck;
  struct deppossi *psearch, **newpossilastp, *possi, *newpossi, *pdep;
  FILE *conff;
  struct filenamenode *namenode;
  struct stat stab, oldfs;
  struct pkg_deconf_list *deconpil, *deconpiltemp;
  struct pkginfo *fixbytrigaw;

  cleanup_pkg_failed= cleanup_conflictor_failed= 0;

  pfilename = summarize_filename(filename);

  if (stat(filename,&stab)) ohshite(_("cannot access archive"));

  /* We can't ‘tentatively-reassemble’ packages. */
  if (!f_noact) {
    if (!deb_reassemble(&filename, &pfilename))
      return;
  }

  /* Verify the package. */
  if (!f_nodebsig)
    deb_verify(filename);

  /* Get the control information directory. */
  cidir = get_control_dir(cidir);
  cidirrest = cidir + strlen(cidir);
  push_cleanup(cu_cidir, ~0, NULL, 0, 2, (void *)cidir, (void *)cidirrest);

  pid = subproc_fork();
  if (pid == 0) {
    cidirrest[-1] = '\0';
    execlp(BACKEND, BACKEND, "--control", filename, cidir, NULL);
    ohshite(_("unable to execute %s (%s)"),
            _("package control information extraction"), BACKEND);
  }
  subproc_wait_check(pid, BACKEND " --control", 0);

  /* We want to guarantee the extracted files are on the disk, so that the
   * subsequent renames to the info database do not end up with old or zero
   * length files in case of a system crash. As neither dpkg-deb nor tar do
   * explicit fsync()s, we have to do them here.
   * XXX: This could be avoided by switching to an internal tar extractor. */
  dir_sync_contents(cidir);

  strcpy(cidirrest,CONTROLFILE);

  parsedb(cidir, pdb_parse_binary | pdb_ignorefiles | parsedb_force_flags(),
          &pkg);
  if (!pkg->files) {
    pkg->files= nfmalloc(sizeof(struct filedetails));
    pkg->files->next = NULL;
    pkg->files->name = pkg->files->msdosname = pkg->files->md5sum = NULL;
  }
  /* Always nfmalloc. Otherwise, we may overwrite some other field (like
   * md5sum). */
  psize = nfmalloc(30);
  sprintf(psize, "%jd", (intmax_t)stab.st_size);
  pkg->files->size = psize;

  if (cipaction->arg_int == act_avail) {
    printf(_("Recorded info about %s from %s.\n"),
           pkgbin_name(pkg, &pkg->available, pnaw_nonambig), pfilename);
    pop_cleanup(ehflag_normaltidy);
    return;
  }

  if (pkg->available.arch->type != arch_all &&
      pkg->available.arch->type != arch_native)
    forcibleerr(fc_architecture,
                _("package architecture (%s) does not match system (%s)"),
                pkg->available.arch->name, dpkg_arch_get(arch_native)->name);

  for (deconpil= deconfigure;
       deconpil;
       deconpil= deconpiltemp) {
    deconpiltemp= deconpil->next;
    free(deconpil);
  }
  deconfigure = NULL;
  clear_istobes();

  if (!wanttoinstall(pkg)) {
      pop_cleanup(ehflag_normaltidy);
      return;
  }

  /* Check if anything is installed that we conflict with, or not installed
   * that we need. */
  pkg->clientdata->istobe= itb_installnew;

  for (dsearch= pkg->available.depends; dsearch; dsearch= dsearch->next) {
    switch (dsearch->type) {
    case dep_conflicts:
      /* Look for things we conflict with. */
      check_conflict(dsearch, pkg, pfilename);
      break;
    case dep_breaks:
      /* Look for things we break. */
      check_breaks(dsearch, pkg, pfilename);
      break;
    case dep_provides:
      /* Look for things that conflict with what we provide. */
      for (psearch = dsearch->list->ed->depended.installed;
           psearch;
           psearch = psearch->rev_next) {
        if (psearch->up->type != dep_conflicts)
          continue;
        check_conflict(psearch->up, pkg, pfilename);
      }
      break;
    case dep_suggests:
    case dep_recommends:
    case dep_depends:
    case dep_replaces:
    case dep_enhances:
      /* Ignore these here. */
      break;
    case dep_predepends:
      if (!depisok(dsearch, &depprobwhy, NULL, &fixbytrigaw, true)) {
        if (fixbytrigaw) {
          while (fixbytrigaw->trigaw.head)
            trigproc(fixbytrigaw->trigaw.head->pend);
        } else {
          varbuf_end_str(&depprobwhy);
          fprintf(stderr, _("dpkg: regarding %s containing %s, pre-dependency problem:\n%s"),
                  pfilename, pkgbin_name(pkg, &pkg->available, pnaw_nonambig),
                  depprobwhy.buf);
          if (!force_depends(dsearch->list))
            ohshit(_("pre-dependency problem - not installing %.250s"),
                   pkgbin_name(pkg, &pkg->available, pnaw_nonambig));
          warning(_("ignoring pre-dependency problem!"));
        }
      }
    }
  }
  /* Look for things that conflict with us. */
  for (psearch = pkg->set->depended.installed; psearch; psearch = psearch->rev_next) {
    if (psearch->up->type != dep_conflicts) continue;
    check_conflict(psearch->up, pkg, pfilename);
  }

  ensure_allinstfiles_available();
  filesdbinit();
  trig_file_interests_ensure();

  if (pkg->status != stat_notinstalled && pkg->status != stat_configfiles) {
    printf(_("Preparing to replace %s %s (using %s) ...\n"),
           pkg_name(pkg, pnaw_nonambig),
           versiondescribe(&pkg->installed.version,vdew_nonambig),
           pfilename);
    log_action("upgrade", pkg, &pkg->installed);
  } else {
    printf(_("Unpacking %s (from %s) ...\n"),
           pkgbin_name(pkg, &pkg->available, pnaw_nonambig), pfilename);
    log_action("install", pkg, &pkg->available);
  }

  if (f_noact) {
    pop_cleanup(ehflag_normaltidy);
    return;
  }

  /*
   * OK, we're going ahead.
   */

  trig_activate_packageprocessing(pkg);
  strcpy(cidirrest, TRIGGERSCIFILE);
  trig_parse_ci(cidir, NULL, trig_cicb_statuschange_activate, pkg, &pkg->available);

  /* Read the conffiles, and copy the hashes across. */
  newconffiles = NULL;
  newconffileslastp = &newconffiles;
  push_cleanup(cu_fileslist, ~0, NULL, 0, 0);
  strcpy(cidirrest,CONFFILESFILE);
  conff= fopen(cidir,"r");
  if (conff) {
    push_cleanup(cu_closestream, ehflag_bombout, NULL, 0, 1, (void *)conff);
    while (fgets(conffilenamebuf,MAXCONFFILENAME-2,conff)) {
      struct filepackages_iterator *iter;

      p= conffilenamebuf + strlen(conffilenamebuf);
      assert(p != conffilenamebuf);
      if (p[-1] != '\n')
        ohshit(_("name of conffile (starting `%.250s') is too long (>%d characters)"),
               conffilenamebuf, MAXCONFFILENAME);
      while (p > conffilenamebuf && isspace(p[-1])) --p;
      if (p == conffilenamebuf) continue;
      *p = '\0';
      namenode= findnamenode(conffilenamebuf, 0);
      namenode->oldhash= NEWCONFFILEFLAG;
      newconff= newconff_append(&newconffileslastp, namenode);

      /* Let's see if any packages have this file. If they do we
       * check to see if they listed it as a conffile, and if they did
       * we copy the hash across. Since (for plain file conffiles,
       * which is the only kind we are supposed to have) there will
       * only be one package which ‘has’ the file, this will usually
       * mean we only look in the package which we're installing now.
       * The ‘conffiles’ data in the status file is ignored when a
       * package isn't also listed in the file ownership database as
       * having that file. If several packages are listed as owning
       * the file we pick one at random. */
      searchconff = NULL;

      iter = filepackages_iter_new(newconff->namenode);
      while ((otherpkg = filepackages_iter_next(iter))) {
        debug(dbg_conffdetail,
              "process_archive conffile `%s' in package %s - conff ?",
              newconff->namenode->name, pkg_name(otherpkg, pnaw_nonambig));
        for (searchconff = otherpkg->installed.conffiles;
             searchconff && strcmp(newconff->namenode->name, searchconff->name);
             searchconff = searchconff->next)
          debug(dbg_conffdetail,
                "process_archive conffile `%s' in package %s - conff ? not `%s'",
                newconff->namenode->name, pkg_name(otherpkg, pnaw_nonambig),
                searchconff->name);
        if (searchconff) {
          debug(dbg_conff,
                "process_archive conffile `%s' package=%s %s hash=%s",
                newconff->namenode->name, pkg_name(otherpkg, pnaw_nonambig),
                otherpkg == pkg ? "same" : "different!",
                searchconff->hash);
          if (otherpkg == pkg)
            break;
        }
      }
      filepackages_iter_free(iter);

      if (searchconff) {
        newconff->namenode->oldhash= searchconff->hash;
	/* We don't copy ‘obsolete’; it's not obsolete in the new package. */
      } else {
        debug(dbg_conff,"process_archive conffile `%s' no package, no hash",
              newconff->namenode->name);
      }
      newconff->namenode->flags |= fnnf_new_conff;
    }
    if (ferror(conff)) ohshite(_("read error in %.250s"),cidir);
    pop_cleanup(ehflag_normaltidy); /* conff = fopen() */
    if (fclose(conff)) ohshite(_("error closing %.250s"),cidir);
  } else {
    if (errno != ENOENT) ohshite(_("error trying to open %.250s"),cidir);
  }

  /* All the old conffiles are marked with a flag, so that we don't delete
   * them if they seem to disappear completely. */
  oldconffsetflags(pkg->installed.conffiles);
  for (i = 0 ; i < cflict_index ; i++) {
    oldconffsetflags(conflictor[i]->installed.conffiles);
  }

  oldversionstatus= pkg->status;

  assert(oldversionstatus <= stat_installed);
  debug(dbg_general,"process_archive oldversionstatus=%s",
        statusstrings[oldversionstatus]);

  if (oldversionstatus == stat_halfconfigured ||
      oldversionstatus == stat_triggersawaited ||
      oldversionstatus == stat_triggerspending ||
      oldversionstatus == stat_installed) {
    pkg_set_eflags(pkg, eflag_reinstreq);
    pkg_set_status(pkg, stat_halfconfigured);
    modstatdb_note(pkg);
    push_cleanup(cu_prermupgrade, ~ehflag_normaltidy, NULL, 0, 1, (void *)pkg);
    if (versioncompare(&pkg->available.version,
                       &pkg->installed.version) >= 0) /* Upgrade or reinstall */
      maintainer_script_alternative(pkg, PRERMFILE, "pre-removal", cidir, cidirrest,
                                    "upgrade", "failed-upgrade");
    else /* Downgrade => no fallback */
      maintainer_script_installed(pkg, PRERMFILE, "pre-removal", "upgrade",
                                  versiondescribe(&pkg->available.version,
                                                  vdew_nonambig), NULL);
    pkg_set_status(pkg, stat_unpacked);
    oldversionstatus= stat_unpacked;
    modstatdb_note(pkg);
  }

  for (deconpil= deconfigure; deconpil; deconpil= deconpil->next) {
    struct pkginfo *removing = deconpil->pkg_removal;

    if (removing)
      printf(_("De-configuring %s, to allow removal of %s ...\n"),
             pkg_name(deconpil->pkg, pnaw_nonambig),
             pkg_name(removing, pnaw_nonambig));
    else
      printf(_("De-configuring %s ...\n"),
             pkg_name(deconpil->pkg, pnaw_nonambig));

    trig_activate_packageprocessing(deconpil->pkg);
    pkg_set_status(deconpil->pkg, stat_halfconfigured);
    modstatdb_note(deconpil->pkg);

    /* This means that we *either* go and run postinst abort-deconfigure,
     * *or* queue the package for later configure processing, depending
     * on which error cleanup route gets taken. */
    push_cleanup(cu_prermdeconfigure, ~ehflag_normaltidy,
                 ok_prermdeconfigure, ehflag_normaltidy,
                 3, (void*)deconpil->pkg, (void*)removing, (void*)pkg);

    if (removing) {
      maintainer_script_installed(deconpil->pkg, PRERMFILE, "pre-removal",
                                  "deconfigure", "in-favour", pkg->set->name,
                                  versiondescribe(&pkg->available.version,
                                                  vdew_nonambig),
                                  "removing", removing->set->name,
                                  versiondescribe(&removing->installed.version,
                                                  vdew_nonambig),
                                  NULL);
    } else {
      maintainer_script_installed(deconpil->pkg, PRERMFILE, "pre-removal",
                                  "deconfigure", "in-favour", pkg->set->name,
                                  versiondescribe(&pkg->available.version,
                                                  vdew_nonambig),
                                  NULL);
    }
  }

  for (i = 0 ; i < cflict_index; i++) {
    if (!(conflictor[i]->status == stat_halfconfigured ||
          conflictor[i]->status == stat_triggersawaited ||
          conflictor[i]->status == stat_triggerspending ||
          conflictor[i]->status == stat_installed)) continue;
    trig_activate_packageprocessing(conflictor[i]);
    pkg_set_status(conflictor[i], stat_halfconfigured);
    modstatdb_note(conflictor[i]);
    push_cleanup(cu_prerminfavour, ~ehflag_normaltidy, NULL, 0,
                 2,(void*)conflictor[i],(void*)pkg);
    maintainer_script_installed(conflictor[i], PRERMFILE, "pre-removal",
                                "remove", "in-favour", pkg->set->name,
                                versiondescribe(&pkg->available.version,
                                                vdew_nonambig),
                                NULL);
    pkg_set_status(conflictor[i], stat_halfinstalled);
    modstatdb_note(conflictor[i]);
  }

  pkg_set_eflags(pkg, eflag_reinstreq);
  if (pkg->status == stat_notinstalled)
    pkg->installed.version= pkg->available.version;
  pkg_set_status(pkg, stat_halfinstalled);
  modstatdb_note(pkg);
  if (oldversionstatus == stat_notinstalled) {
    push_cleanup(cu_preinstverynew, ~ehflag_normaltidy, NULL, 0,
                 3,(void*)pkg,(void*)cidir,(void*)cidirrest);
    maintainer_script_new(pkg, PREINSTFILE, "pre-installation", cidir, cidirrest,
                          "install", NULL);
  } else if (oldversionstatus == stat_configfiles) {
    push_cleanup(cu_preinstnew, ~ehflag_normaltidy, NULL, 0,
                 3,(void*)pkg,(void*)cidir,(void*)cidirrest);
    maintainer_script_new(pkg, PREINSTFILE, "pre-installation", cidir, cidirrest,
                          "install", versiondescribe(&pkg->installed.version,
                                                     vdew_nonambig),
                          NULL);
  } else {
    push_cleanup(cu_preinstupgrade, ~ehflag_normaltidy, NULL, 0,
                 4,(void*)pkg,(void*)cidir,(void*)cidirrest,(void*)&oldversionstatus);
    maintainer_script_new(pkg, PREINSTFILE, "pre-installation", cidir, cidirrest,
                          "upgrade", versiondescribe(&pkg->installed.version,
                                                     vdew_nonambig),
                          NULL);
    printf(_("Unpacking replacement %.250s ...\n"),
           pkgbin_name(pkg, &pkg->available, pnaw_nonambig));
  }

  /*
   * Now we unpack the archive, backing things up as we go.
   * For each file, we check to see if it already exists.
   * There are several possibilities:
   *
   * + We are trying to install a non-directory ...
   *  - It doesn't exist. In this case we simply extract it.
   *  - It is a plain file, device, symlink, &c. We do an ‘atomic
   *    overwrite’ using link() and rename(), but leave a backup copy.
   *    Later, when we delete the backup, we remove it from any other
   *    packages' lists.
   *  - It is a directory. In this case it depends on whether we're
   *    trying to install a symlink or something else.
   *   = If we're not trying to install a symlink we move the directory
   *     aside and extract the node. Later, when we recursively remove
   *     the backed-up directory, we remove it from any other packages'
   *     lists.
   *   = If we are trying to install a symlink we do nothing - ie,
   *     dpkg will never replace a directory tree with a symlink. This
   *     is to avoid embarrassing effects such as replacing a directory
   *     tree with a link to a link to the original directory tree.
   * + We are trying to install a directory ...
   *  - It doesn't exist. We create it with the appropriate modes.
   *  - It exists as a directory or a symlink to one. We do nothing.
   *  - It is a plain file or a symlink (other than to a directory).
   *    We move it aside and create the directory. Later, when we
   *    delete the backup, we remove it from any other packages' lists.
   *
   *                   Install non-dir   Install symlink   Install dir
   *  Exists not               X               X                X
   *  File/node/symlink       LXR             LXR              BXR
   *  Directory               BXR              -                -
   *
   *    X: extract file/node/link/directory
   *   LX: atomic overwrite leaving backup
   *    B: ordinary backup
   *    R: later remove from other packages' lists
   *    -: do nothing
   *
   * After we've done this we go through the remaining things in the
   * lists of packages we're trying to remove (including the old
   * version of the current package). This happens in reverse order,
   * so that we process files before the directories (or symlinks-to-
   * directories) containing them.
   *
   * + If the thing is a conffile then we leave it alone for the purge
   *   operation.
   * + Otherwise, there are several possibilities too:
   *  - The listed thing does not exist. We ignore it.
   *  - The listed thing is a directory or a symlink to a directory.
   *    We delete it only if it isn't listed in any other package.
   *  - The listed thing is not a directory, but was part of the package
   *    that was upgraded, we check to make sure the files aren't the
   *    same ones from the old package by checking dev/inode
   *  - The listed thing is not a directory or a symlink to one (ie,
   *    it's a plain file, device, pipe, &c, or a symlink to one, or a
   *    dangling symlink). We delete it.
   *
   * The removed packages' list becomes empty (of course, the new
   * version of the package we're installing will have a new list,
   * which replaces the old version's list).
   *
   * If at any stage we remove a file from a package's list, and the
   * package isn't one we're already processing, and the package's
   * list becomes empty as a result, we ‘vanish’ the package. This
   * means that we run its postrm with the ‘disappear’ argument, and
   * put the package in the ‘not-installed’ state. If it had any
   * conffiles, their hashes and ownership will have been transferred
   * already, so we just ignore those and forget about them from the
   * point of view of the disappearing package.
   *
   * NOTE THAT THE OLD POSTRM IS RUN AFTER THE NEW PREINST, since the
   * files get replaced ‘as we go’.
   */

  m_pipe(p1);
  push_cleanup(cu_closepipe, ehflag_bombout, NULL, 0, 1, (void *)&p1[0]);
  pid = subproc_fork();
  if (pid == 0) {
    m_dup2(p1[1],1); close(p1[0]); close(p1[1]);
    execlp(BACKEND, BACKEND, "--fsys-tarfile", filename, NULL);
    ohshite(_("unable to execute %s (%s)"),
            _("package filesystem archive extraction"), BACKEND);
  }
  close(p1[1]);
  p1[1] = -1;

  newfileslist = NULL;
  tc.newfilesp = &newfileslist;
  push_cleanup(cu_fileslist, ~0, NULL, 0, 0);
  tc.pkg= pkg;
  tc.backendpipe= p1[0];

  r = tar_extractor(&tc, &tf);
  if (r) {
    if (errno) {
      ohshite(_("error reading dpkg-deb tar output"));
    } else {
      ohshit(_("corrupted filesystem tarfile - corrupted package archive"));
    }
  }
  fd_skip(p1[0], -1, _("dpkg-deb: zap possible trailing zeros"));
  close(p1[0]);
  p1[0] = -1;
  subproc_wait_check(pid, BACKEND " --fsys-tarfile", PROCPIPE);

  tar_deferred_extract(newfileslist, pkg);

  if (oldversionstatus == stat_halfinstalled || oldversionstatus == stat_unpacked) {
    /* Packages that were in ‘installed’ and ‘postinstfailed’ have been
     * reduced to ‘unpacked’ by now, by the running of the prerm script. */
    pkg_set_status(pkg, stat_halfinstalled);
    modstatdb_note(pkg);
    push_cleanup(cu_postrmupgrade, ~ehflag_normaltidy, NULL, 0, 1, (void *)pkg);
    maintainer_script_alternative(pkg, POSTRMFILE, "post-removal", cidir, cidirrest,
                                  "upgrade", "failed-upgrade");
  }

  /* If anything goes wrong while tidying up it's a bit late to do
   * anything about it. However, we don't install the new status
   * info yet, so that a future dpkg installation will put everything
   * right (we hope).
   *
   * If something does go wrong later the ‘conflictor’ package will be
   * left in the ‘removal_failed’ state. Removing or installing it
   * will be impossible if it was required because of the conflict with
   * the package we're installing now and (presumably) the dependency
   * by other packages. This means that the files it contains in
   * common with this package will hang around until we successfully
   * get this package installed, after which point we can trust the
   * conflicting package's file list, which will have been updated to
   * remove any files in this package. */
  push_checkpoint(~ehflag_bombout, ehflag_normaltidy);

  /* Now we delete all the files that were in the old version of
   * the package only, except (old or new) conffiles, which we leave
   * alone. */
  reversefilelist_init(&rlistit,pkg->clientdata->files);
  while ((namenode= reversefilelist_next(&rlistit))) {
    struct filenamenode *usenode;

    if ((namenode->flags & fnnf_new_conff) ||
        (namenode->flags & fnnf_new_inarchive))
      continue;

    usenode = namenodetouse(namenode, pkg, &pkg->installed);
    trig_file_activate(usenode, pkg);

    varbuf_trunc(&fnamevb, fnameidlu);
    varbuf_add_str(&fnamevb, usenode->name);
    varbuf_end_str(&fnamevb);

    if (!stat(namenode->name,&stab) && S_ISDIR(stab.st_mode)) {
      debug(dbg_eachfiledetail, "process_archive: %s is a directory",
	    namenode->name);
      if (dir_is_used_by_others(namenode, pkg))
        continue;
    }

    if (lstat(fnamevb.buf, &oldfs)) {
      if (!(errno == ENOENT || errno == ELOOP || errno == ENOTDIR))
	warning(_("could not stat old file '%.250s' so not deleting it: %s"),
	        fnamevb.buf, strerror(errno));
      continue;
    }
    if (S_ISDIR(oldfs.st_mode)) {
      if (rmdir(fnamevb.buf)) {
	warning(_("unable to delete old directory '%.250s': %s"),
	        namenode->name, strerror(errno));
      } else if ((namenode->flags & fnnf_old_conff)) {
	warning(_("old conffile '%.250s' was an empty directory "
	          "(and has now been deleted)"), namenode->name);
      }
    } else {
      struct fileinlist *sameas = NULL;
      static struct stat empty_stat;
      struct varbuf cfilename = VARBUF_INIT;

      /*
       * Ok, it's an old file, but is it really not in the new package?
       * It might be known by a different name because of symlinks.
       *
       * We need to check to make sure, so we stat the file, then compare
       * it to the new list. If we find a dev/inode match, we assume they
       * are the same file, and leave it alone. NOTE: we don't check in
       * other packages for sanity reasons (we don't want to stat _all_
       * the files on the system).
       *
       * We run down the list of _new_ files in this package. This keeps
       * the process a little leaner. We are only worried about new ones
       * since ones that stayed the same don't really apply here.
       */

      /* If we can't stat the old or new file, or it's a directory,
       * we leave it up to the normal code. */
      debug(dbg_eachfile, "process_archive: checking %s for same files on "
	    "upgrade/downgrade", fnamevb.buf);

      for (cfile= newfileslist; cfile; cfile= cfile->next) {
	/* If the file has been filtered then treat it as if it didn't exist
	 * on the file system. */
	if (cfile->namenode->flags & fnnf_filtered)
	  continue;
	if (!cfile->namenode->filestat) {
	  struct stat tmp_stat;

	  varbuf_reset(&cfilename);
	  varbuf_add_str(&cfilename, instdir);
	  varbuf_add_char(&cfilename, '/');
	  varbuf_add_str(&cfilename, cfile->namenode->name);
	  varbuf_end_str(&cfilename);

	  if (lstat(cfilename.buf, &tmp_stat) == 0) {
	    cfile->namenode->filestat = nfmalloc(sizeof(struct stat));
	    memcpy(cfile->namenode->filestat, &tmp_stat, sizeof(struct stat));
	  } else {
	    if (!(errno == ENOENT || errno == ELOOP || errno == ENOTDIR))
	      ohshite(_("unable to stat other new file `%.250s'"),
		      cfile->namenode->name);
	    cfile->namenode->filestat = &empty_stat;
	    continue;
	  }
	}
	if (cfile->namenode->filestat == &empty_stat)
	  continue;
	if (oldfs.st_dev == cfile->namenode->filestat->st_dev &&
	    oldfs.st_ino == cfile->namenode->filestat->st_ino) {
	  if (sameas)
	    warning(_("old file '%.250s' is the same as several new files! "
	              "(both '%.250s' and '%.250s')"), fnamevb.buf,
		    sameas->namenode->name, cfile->namenode->name);
	  sameas= cfile;
	  debug(dbg_eachfile, "process_archive: not removing %s,"
		" since it matches %s", fnamevb.buf, cfile->namenode->name);
	}
      }

      varbuf_destroy(&cfilename);

      if ((namenode->flags & fnnf_old_conff)) {
	if (sameas) {
	  if (sameas->namenode->flags & fnnf_new_conff) {
	    if (!strcmp(sameas->namenode->oldhash, NEWCONFFILEFLAG)) {
	      sameas->namenode->oldhash= namenode->oldhash;
	      debug(dbg_eachfile, "process_archive: old conff %s"
		    " is same as new conff %s, copying hash",
		    namenode->name, sameas->namenode->name);
	    } else {
	      debug(dbg_eachfile, "process_archive: old conff %s"
		    " is same as new conff %s but latter already has hash",
		    namenode->name, sameas->namenode->name);
	    }
	  }
	} else {
	  debug(dbg_eachfile, "process_archive: old conff %s"
		" is disappearing", namenode->name);
	  namenode->flags |= fnnf_obs_conff;
	  newconff_append(&newconffileslastp, namenode);
	  addfiletolist(&tc, namenode);
	}
	continue;
      }

      if (sameas)
	continue;

      if (secure_unlink_statted(fnamevb.buf, &oldfs)) {
        warning(_("unable to securely remove old file '%.250s': %s"),
                namenode->name, strerror(errno));
      }

    } /* !S_ISDIR */
  }

  /* OK, now we can write the updated files-in-this package list,
   * since we've done away (hopefully) with all the old junk. */
  write_filelist_except(pkg, &pkg->available, newfileslist, 0);

  /* Trigger interests may have changed.
   * Firstly we go through the old list of interests deleting them.
   * Then we go through the new list adding them. */
  strcpy(cidirrest, TRIGGERSCIFILE);
  trig_parse_ci(pkgadminfile(pkg, &pkg->installed, TRIGGERSCIFILE),
                trig_cicb_interest_delete, NULL, pkg, &pkg->installed);
  trig_parse_ci(cidir, trig_cicb_interest_add, NULL, pkg, &pkg->available);
  trig_file_interests_save();

  /* We also install the new maintainer scripts, and any other
   * cruft that may have come along with the package. First
   * we go through the existing scripts replacing or removing
   * them as appropriate; then we go through the new scripts
   * (any that are left) and install them. */
  debug(dbg_general, "process_archive updating info directory");
  pkg_infodb_update(pkg, cidir, cidirrest);

  /*
   * Update the status database.
   *
   * This involves copying each field across from the ‘available’
   * to the ‘installed’ half of the pkg structure.
   * For some of the fields we have to do a complicated construction
   * operation; for others we can just copy the value.
   * We tackle the fields in the order they appear, so that
   * we don't miss any out :-).
   * At least we don't have to copy any strings that are referred
   * to, because these are never modified and never freed.
   */

  /* The dependencies are the most difficult. We have to build
   * a whole new forward dependency tree. At least the reverse
   * links (linking our deppossi's into the reverse chains)
   * can be done by copy_dependency_links. */
  newdeplist = NULL;
  newdeplistlastp = &newdeplist;
  for (dep= pkg->available.depends; dep; dep= dep->next) {
    newdep= nfmalloc(sizeof(struct dependency));
    newdep->up= pkg;
    newdep->next = NULL;
    newdep->list = NULL;
    newpossilastp = &newdep->list;
    for (possi= dep->list; possi; possi= possi->next) {
      newpossi= nfmalloc(sizeof(struct deppossi));
      newpossi->up= newdep;
      newpossi->ed= possi->ed;
      newpossi->next = NULL;
      newpossi->rev_next = newpossi->rev_prev = NULL;
      newpossi->arch_is_implicit = possi->arch_is_implicit;
      newpossi->arch = possi->arch;
      newpossi->verrel= possi->verrel;
      if (possi->verrel != dvr_none)
        newpossi->version= possi->version;
      else
        blankversion(&newpossi->version);
      newpossi->cyclebreak = false;
      *newpossilastp= newpossi;
      newpossilastp= &newpossi->next;
    }
    newdep->type= dep->type;
    *newdeplistlastp= newdep;
    newdeplistlastp= &newdep->next;
  }
  /* Right, now we've replicated the forward tree, we
   * get copy_dependency_links to remove all the old dependency
   * structures from the reverse links and add the new dependency
   * structures in instead. It also copies the new dependency
   * structure pointer for this package into the right field. */
  copy_dependency_links(pkg,&pkg->installed.depends,newdeplist,0);

  /* We copy the text fields. */
  pkg->installed.essential= pkg->available.essential;
  pkg->installed.multiarch = pkg->available.multiarch;
  pkg->installed.description= pkg->available.description;
  pkg->installed.maintainer= pkg->available.maintainer;
  pkg->installed.source= pkg->available.source;
  pkg->installed.arch = pkg->available.arch;
  pkg->installed.installedsize= pkg->available.installedsize;
  pkg->installed.version= pkg->available.version;
  pkg->installed.origin = pkg->available.origin;
  pkg->installed.bugs = pkg->available.bugs;

  /* We have to generate our own conffiles structure. */
  pkg->installed.conffiles = NULL;
  iconffileslastp = &pkg->installed.conffiles;
  for (cfile= newconffiles; cfile; cfile= cfile->next) {
    newiconff= nfmalloc(sizeof(struct conffile));
    newiconff->next = NULL;
    newiconff->name= nfstrsave(cfile->namenode->name);
    newiconff->hash= nfstrsave(cfile->namenode->oldhash);
    newiconff->obsolete= !!(cfile->namenode->flags & fnnf_obs_conff);
    *iconffileslastp= newiconff;
    iconffileslastp= &newiconff->next;
  }

  /* We can just copy the arbitrary fields list, because it is
   * never even rearranged. Phew! */
  pkg->installed.arbs= pkg->available.arbs;

  /* Check for disappearing packages:
   * We go through all the packages on the system looking for ones
   * whose files are entirely part of the one we've just unpacked
   * (and which actually *have* some files!).
   *
   * Any that we find are removed - we run the postrm with ‘disappear’
   * as an argument, and remove their info/... files and status info.
   * Conffiles are ignored (the new package had better do something
   * with them!). */
  it = pkg_db_iter_new();
  while ((otherpkg = pkg_db_iter_next_pkg(it)) != NULL) {
    ensure_package_clientdata(otherpkg);
    if (otherpkg == pkg ||
        otherpkg->status == stat_notinstalled ||
        otherpkg->status == stat_configfiles ||
	otherpkg->clientdata->istobe == itb_remove ||
        !otherpkg->clientdata->files) continue;
    debug(dbg_veryverbose, "process_archive checking disappearance %s",
          pkg_name(otherpkg, pnaw_nonambig));
    assert(otherpkg->clientdata->istobe == itb_normal ||
           otherpkg->clientdata->istobe == itb_deconfigure);
    for (cfile= otherpkg->clientdata->files;
         cfile && !strcmp(cfile->namenode->name,"/.");
         cfile= cfile->next);
    if (!cfile) {
      debug(dbg_stupidlyverbose, "process_archive no non-root, no disappear");
      continue;
    }
    for (cfile= otherpkg->clientdata->files;
         cfile && !filesavespackage(cfile,otherpkg,pkg);
         cfile= cfile->next);
    if (cfile) continue;

    /* So dependency things will give right answers ... */
    otherpkg->clientdata->istobe= itb_remove;
    debug(dbg_veryverbose, "process_archive disappear checking dependencies");
    for (pdep = otherpkg->set->depended.installed;
         pdep;
         pdep = pdep->rev_next) {
      if (pdep->up->type != dep_depends && pdep->up->type != dep_predepends &&
          pdep->up->type != dep_recommends) continue;
      if (depisok(pdep->up, &depprobwhy, NULL, NULL, false))
        continue;
      varbuf_end_str(&depprobwhy);
      debug(dbg_veryverbose,"process_archive cannot disappear: %s",depprobwhy.buf);
      break;
    }
    if (!pdep) {
      /* If we haven't found a reason not to yet, let's look some more. */
      for (providecheck= otherpkg->installed.depends;
           providecheck;
           providecheck= providecheck->next) {
        if (providecheck->type != dep_provides) continue;
        for (pdep = providecheck->list->ed->depended.installed;
             pdep;
             pdep = pdep->rev_next) {
          if (pdep->up->type != dep_depends && pdep->up->type != dep_predepends &&
              pdep->up->type != dep_recommends)
            continue;
          if (depisok(pdep->up, &depprobwhy, NULL, NULL, false))
            continue;
          varbuf_end_str(&depprobwhy);
          debug(dbg_veryverbose,"process_archive cannot disappear (provides %s): %s",
                providecheck->list->ed->name, depprobwhy.buf);
          goto break_from_both_loops_at_once;
        }
      }
    break_from_both_loops_at_once:;
    }
    otherpkg->clientdata->istobe= itb_normal;
    if (pdep) continue;

    /* No, we're disappearing it. This is the wrong time to go and
     * run maintainer scripts and things, as we can't back out. But
     * what can we do ?  It has to be run this late. */
    pkg_disappear(otherpkg, pkg);
  } /* while (otherpkg= ... */
  pkg_db_iter_free(it);

  /* Delete files from any other packages' lists.
   * We have to do this before we claim this package is in any
   * sane kind of state, as otherwise we might delete by mistake
   * a file that we overwrote, when we remove the package which
   * had the version we overwrote. To prevent this we make
   * sure that we don't claim this package is OK until we
   * have claimed ‘ownership’ of all its files. */
  for (cfile= newfileslist; cfile; cfile= cfile->next) {
    struct filepackages_iterator *iter;
    struct pkgset *divpkgset;

    if (!(cfile->namenode->flags & fnnf_elide_other_lists)) continue;
    if (cfile->namenode->divert && cfile->namenode->divert->useinstead) {
      divpkgset = cfile->namenode->divert->pkgset;
      if (divpkgset == pkg->set) {
        debug(dbg_eachfile,
              "process_archive not overwriting any `%s' (overriding, `%s')",
              cfile->namenode->name, cfile->namenode->divert->useinstead->name);
        continue;
      } else {
        debug(dbg_eachfile,
              "process_archive looking for overwriting `%s' (overridden by %s)",
              cfile->namenode->name, divpkgset ? divpkgset->name : "<local>");
      }
    } else {
      divpkgset = NULL;
      debug(dbg_eachfile, "process_archive looking for overwriting `%s'",
            cfile->namenode->name);
    }
    iter = filepackages_iter_new(cfile->namenode);
    while ((otherpkg = filepackages_iter_next(iter))) {
      debug(dbg_eachfiledetail, "process_archive ... found in %s",
            pkg_name(otherpkg, pnaw_nonambig));
      /* If !fileslistvalid then it's one of the disappeared packages above
       * and we don't bother with it here, clearly. */
      if (otherpkg == pkg || !otherpkg->clientdata->fileslistvalid)
        continue;
      if (otherpkg->set == divpkgset) {
        debug(dbg_eachfiledetail, "process_archive ... diverted, skipping");
        continue;
      }

      /* Found one. We delete remove the list entry for this file,
       * (and any others in the same package) and then mark the package
       * as requiring a reread. */
      write_filelist_except(otherpkg, &otherpkg->installed,
                            otherpkg->clientdata->files, fnnf_elide_other_lists);
      ensure_package_clientdata(otherpkg);
      debug(dbg_veryverbose, "process_archive overwrote from %s",
            pkg_name(otherpkg, pnaw_nonambig));
    }
    filepackages_iter_free(iter);
  }

  /* Right, the package we've unpacked is now in a reasonable state.
   * The only thing that we have left to do with it is remove
   * backup files, and we can leave the user to fix that if and when
   * it happens (we leave the reinstall required flag, of course). */
  pkg_set_status(pkg, stat_unpacked);
  modstatdb_note(pkg);

  /* Now we delete all the backup files that we made when
   * extracting the archive - except for files listed as conffiles
   * in the new package.
   * This time we count it as an error if something goes wrong.
   *
   * Note that we don't ever delete things that were in the old
   * package as a conffile and don't appear at all in the new.
   * They stay recorded as obsolete conffiles and will eventually
   * (if not taken over by another package) be forgotten. */
  for (cfile= newfileslist; cfile; cfile= cfile->next) {
    if (cfile->namenode->flags & fnnf_new_conff) continue;
    varbuf_trunc(&fnametmpvb, fnameidlu);
    varbuf_add_str(&fnametmpvb,
                   namenodetouse(cfile->namenode, pkg, &pkg->installed)->name);
    varbuf_add_str(&fnametmpvb, DPKGTEMPEXT);
    varbuf_end_str(&fnametmpvb);
    ensure_pathname_nonexisting(fnametmpvb.buf);
  }

  /* OK, we're now fully done with the main package.
   * This is quite a nice state, so we don't unwind past here. */
  pkg_reset_eflags(pkg);
  modstatdb_note(pkg);
  push_checkpoint(~ehflag_bombout, ehflag_normaltidy);

  /* Only the removal of the conflictor left to do.
   * The files list for the conflictor is still a little inconsistent in-core,
   * as we have not yet updated the filename->packages mappings; however,
   * the package->filenames mapping is. */
  for (i = 0 ; i < cflict_index ; i++) {
    /* We need to have the most up-to-date info about which files are
     * what ... */
    ensure_allinstfiles_available();
    removal_bulk(conflictor[i]);
  }

  if (cipaction->arg_int == act_install)
    add_to_queue(pkg);
}
コード例 #4
0
ファイル: archives.c プロジェクト: Minipig/dpkg
int
tarobject(void *ctx, struct tar_entry *ti)
{
  static struct varbuf conffderefn, hardlinkfn, symlinkfn;
  static int fd;
  const char *usename;
  struct filenamenode *usenode;
  struct filenamenode *linknode;

  struct conffile *conff;
  struct tarcontext *tc = ctx;
  bool existingdirectory, keepexisting;
  int statr;
  ssize_t r;
  struct stat stab, stabtmp;
  char databuf[TARBLKSZ];
  struct file_stat *st;
  struct fileinlist *nifd, **oldnifd;
  struct pkginfo *divpkg, *otherpkg;

  ensureobstackinit();

  /* Append to list of files.
   * The trailing ‘/’ put on the end of names in tarfiles has already
   * been stripped by tar_extractor(). */
  oldnifd= tc->newfilesp;
  nifd= addfiletolist(tc, findnamenode(ti->name, 0));
  nifd->namenode->flags |= fnnf_new_inarchive;

  debug(dbg_eachfile,
        "tarobject ti->name='%s' mode=%lo owner=%u.%u type=%d(%c)"
        " ti->linkname='%s' namenode='%s' flags=%o instead='%s'",
        ti->name, (long)ti->stat.mode,
        (unsigned)ti->stat.uid, (unsigned)ti->stat.gid,
        ti->type,
        ti->type >= '0' && ti->type <= '6' ? "-hlcbdp"[ti->type - '0'] : '?',
        ti->linkname,
        nifd->namenode->name, nifd->namenode->flags,
        nifd->namenode->divert && nifd->namenode->divert->useinstead
        ? nifd->namenode->divert->useinstead->name : "<none>");

  if (nifd->namenode->divert && nifd->namenode->divert->camefrom) {
    divpkg= nifd->namenode->divert->pkg;

    if (divpkg) {
      forcibleerr(fc_overwritediverted,
                  _("trying to overwrite `%.250s', which is the "
                    "diverted version of `%.250s' (package: %.100s)"),
                  nifd->namenode->name, nifd->namenode->divert->camefrom->name,
                  divpkg->name);
    } else {
      forcibleerr(fc_overwritediverted,
                  _("trying to overwrite `%.250s', which is the "
                    "diverted version of `%.250s'"),
                  nifd->namenode->name, nifd->namenode->divert->camefrom->name);
    }
  }

  if (nifd->namenode->statoverride)
    st = nifd->namenode->statoverride;
  else
    st = &ti->stat;

  usenode = namenodetouse(nifd->namenode, tc->pkg);
  usename = usenode->name + 1; /* Skip the leading '/'. */

  trig_file_activate(usenode, tc->pkg);

  if (nifd->namenode->flags & fnnf_new_conff) {
    /* If it's a conffile we have to extract it next to the installed
     * version (i.e. we do the usual link-following). */
    if (conffderef(tc->pkg, &conffderefn, usename))
      usename= conffderefn.buf;
    debug(dbg_conff,"tarobject fnnf_new_conff deref=`%s'",usename);
  }

  setupfnamevbs(usename);

  statr= lstat(fnamevb.buf,&stab);
  if (statr) {
    /* The lstat failed. */
    if (errno != ENOENT && errno != ENOTDIR)
      ohshite(_("unable to stat `%.255s' (which I was about to install)"),
              ti->name);
    /* OK, so it doesn't exist.
     * However, it's possible that we were in the middle of some other
     * backup/restore operation and were rudely interrupted.
     * So, we see if we have .dpkg-tmp, and if so we restore it. */
    if (rename(fnametmpvb.buf,fnamevb.buf)) {
      if (errno != ENOENT && errno != ENOTDIR)
        ohshite(_("unable to clean up mess surrounding `%.255s' before "
                  "installing another version"), ti->name);
      debug(dbg_eachfiledetail,"tarobject nonexistent");
    } else {
      debug(dbg_eachfiledetail,"tarobject restored tmp to main");
      statr= lstat(fnamevb.buf,&stab);
      if (statr) ohshite(_("unable to stat restored `%.255s' before installing"
                           " another version"), ti->name);
    }
  } else {
    debug(dbg_eachfiledetail,"tarobject already exists");
  }

  /* Check to see if it's a directory or link to one and we don't need to
   * do anything. This has to be done now so that we don't die due to
   * a file overwriting conflict. */
  existingdirectory = false;
  switch (ti->type) {
  case tar_filetype_symlink:
    /* If it's already an existing directory, do nothing. */
    if (!statr && S_ISDIR(stab.st_mode)) {
      debug(dbg_eachfiledetail, "tarobject symlink exists as directory");
      existingdirectory = true;
    } else if (!statr && S_ISLNK(stab.st_mode)) {
      if (linktosameexistingdir(ti, fnamevb.buf, &symlinkfn))
        existingdirectory = true;
    }
    break;
  case tar_filetype_dir:
    /* If it's already an existing directory, do nothing. */
    if (!stat(fnamevb.buf,&stabtmp) && S_ISDIR(stabtmp.st_mode)) {
      debug(dbg_eachfiledetail, "tarobject directory exists");
      existingdirectory = true;
    }
    break;
  case tar_filetype_file:
  case tar_filetype_chardev:
  case tar_filetype_blockdev:
  case tar_filetype_fifo:
  case tar_filetype_hardlink:
    break;
  default:
    ohshit(_("archive contained object `%.255s' of unknown type 0x%x"),
           ti->name, ti->type);
  }

  keepexisting = false;
  if (!existingdirectory) {
    struct filepackages_iterator *iter;

    iter = filepackages_iter_new(nifd->namenode);
    while ((otherpkg = filepackages_iter_next(iter))) {
      if (otherpkg == tc->pkg)
        continue;
      debug(dbg_eachfile, "tarobject ... found in %s", otherpkg->name);

      if (nifd->namenode->divert && nifd->namenode->divert->useinstead) {
        /* Right, so we may be diverting this file. This makes the conflict
         * OK iff one of us is the diverting package (we don't need to
         * check for both being the diverting package, obviously). */
        divpkg = nifd->namenode->divert->pkg;
        debug(dbg_eachfile, "tarobject ... diverted, divpkg=%s",
              divpkg ? divpkg->name : "<none>");
        if (otherpkg == divpkg || tc->pkg == divpkg)
          continue;
      }

      /* Nope? Hmm, file conflict, perhaps. Check Replaces. */
      switch (otherpkg->clientdata->replacingfilesandsaid) {
      case 2:
        keepexisting = true;
      case 1:
        continue;
      }

      /* Is the package with the conflicting file in the “config files only”
       * state? If so it must be a config file and we can silenty take it
       * over. */
      if (otherpkg->status == stat_configfiles)
        continue;

      /* Perhaps we're removing a conflicting package? */
      if (otherpkg->clientdata->istobe == itb_remove)
        continue;

      /* Is the file an obsolete conffile in the other package
       * and a conffile in the new package? */
      if ((nifd->namenode->flags & fnnf_new_conff) &&
          !statr && S_ISREG(stab.st_mode)) {
        for (conff = otherpkg->installed.conffiles;
             conff;
             conff = conff->next) {
          if (!conff->obsolete)
            continue;
          if (stat(conff->name, &stabtmp))
            if (errno == ENOENT || errno == ENOTDIR || errno == ELOOP)
              continue;
            if (stabtmp.st_dev == stab.st_dev &&
                stabtmp.st_ino == stab.st_ino)
              break;
        }
        if (conff) {
          debug(dbg_eachfiledetail, "tarobject other's obsolete conffile");
          /* process_archive() will have copied its hash already. */
          continue;
        }
      }

      if (does_replace(tc->pkg, &tc->pkg->available,
                       otherpkg, &otherpkg->installed)) {
        printf(_("Replacing files in old package %s ...\n"),otherpkg->name);
        otherpkg->clientdata->replacingfilesandsaid = 1;
      } else if (does_replace(otherpkg, &otherpkg->installed,
                              tc->pkg, &tc->pkg->available)) {
        printf(_("Replaced by files in installed package %s ...\n"),
               otherpkg->name);
        otherpkg->clientdata->replacingfilesandsaid = 2;
        nifd->namenode->flags &= ~fnnf_new_inarchive;
        keepexisting = true;
      } else {
        if (!statr && S_ISDIR(stab.st_mode)) {
          forcibleerr(fc_overwritedir,
                      _("trying to overwrite directory '%.250s' "
                        "in package %.250s %.250s with nondirectory"),
                      nifd->namenode->name, otherpkg->name,
                      versiondescribe(&otherpkg->installed.version,
                                      vdew_nonambig));
        } else {
          /* At this point we are replacing something without a Replaces.
           * If the new object is a directory and the previous object does
           * not exist assume it's also a directory and don't complain. */
          if (!(statr && ti->type == tar_filetype_dir))
            forcibleerr(fc_overwrite,
                        _("trying to overwrite '%.250s', "
                          "which is also in package %.250s %.250s"),
                        nifd->namenode->name, otherpkg->name,
                        versiondescribe(&otherpkg->installed.version,
                                        vdew_nonambig));
        }
      }
    }
    filepackages_iter_free(iter);
  }

  if (keepexisting) {
    remove_file_from_list(tc, ti, oldnifd, nifd);
    tarfile_skip_one_forward(tc, ti);
    return 0;
  }

  if (filter_should_skip(ti)) {
    nifd->namenode->flags &= ~fnnf_new_inarchive;
    nifd->namenode->flags |= fnnf_filtered;
    tarfile_skip_one_forward(tc, ti);

    return 0;
  }

  if (existingdirectory)
    return 0;

  /* Now, at this stage we want to make sure neither of .dpkg-new and
   * .dpkg-tmp are hanging around. */
  ensure_pathname_nonexisting(fnamenewvb.buf);
  ensure_pathname_nonexisting(fnametmpvb.buf);

  /* Now we start to do things that we need to be able to undo
   * if something goes wrong. Watch out for the CLEANUP comments to
   * keep an eye on what's installed on the disk at each point. */
  push_cleanup(cu_installnew, ~ehflag_normaltidy, NULL, 0, 1, (void *)nifd);

  /*
   * CLEANUP: Now we either have the old file on the disk, or not, in
   * its original filename.
   */

  /* Extract whatever it is as .dpkg-new ... */
  switch (ti->type) {
  case tar_filetype_file:
    /* We create the file with mode 0 to make sure nobody can do anything with
     * it until we apply the proper mode, which might be a statoverride. */
    fd= open(fnamenewvb.buf, (O_CREAT|O_EXCL|O_WRONLY), 0);
    if (fd < 0)
      ohshite(_("unable to create `%.255s' (while processing `%.255s')"),
              fnamenewvb.buf, ti->name);
    push_cleanup(cu_closefd, ehflag_bombout, NULL, 0, 1, &fd);
    debug(dbg_eachfiledetail, "tarobject file open size=%lu",
          (unsigned long)ti->size);
    { char fnamebuf[256];
    fd_fd_copy(tc->backendpipe, fd, ti->size,
               _("backend dpkg-deb during `%.255s'"),
               path_quote_filename(fnamebuf, ti->name, 256));
    }
    r = ti->size % TARBLKSZ;
    if (r > 0)
      if (safe_read(tc->backendpipe, databuf, TARBLKSZ - r) == -1)
        ohshite(_("error reading from dpkg-deb pipe"));

    fd_writeback_init(fd);

    if (nifd->namenode->statoverride)
      debug(dbg_eachfile, "tarobject ... stat override, uid=%d, gid=%d, mode=%04o",
			  nifd->namenode->statoverride->uid,
			  nifd->namenode->statoverride->gid,
			  nifd->namenode->statoverride->mode);
    if (fchown(fd, st->uid, st->gid))
      ohshite(_("error setting ownership of `%.255s'"), ti->name);
    if (fchmod(fd, st->mode & ~S_IFMT))
      ohshite(_("error setting permissions of `%.255s'"), ti->name);

    /* Postpone the fsync, to try to avoid massive I/O degradation. */
    if (!fc_unsafe_io)
      nifd->namenode->flags |= fnnf_deferred_fsync;

    pop_cleanup(ehflag_normaltidy); /* fd = open(fnamenewvb.buf) */
    if (close(fd))
      ohshite(_("error closing/writing `%.255s'"), ti->name);
    newtarobject_utime(fnamenewvb.buf, st);
    break;
  case tar_filetype_fifo:
    if (mkfifo(fnamenewvb.buf,0))
      ohshite(_("error creating pipe `%.255s'"), ti->name);
    debug(dbg_eachfiledetail, "tarobject fifo");
    newtarobject_allmodes(fnamenewvb.buf, st);
    break;
  case tar_filetype_chardev:
    if (mknod(fnamenewvb.buf, S_IFCHR, ti->dev))
      ohshite(_("error creating device `%.255s'"), ti->name);
    debug(dbg_eachfiledetail, "tarobject chardev");
    newtarobject_allmodes(fnamenewvb.buf, st);
    break;
  case tar_filetype_blockdev:
    if (mknod(fnamenewvb.buf, S_IFBLK, ti->dev))
      ohshite(_("error creating device `%.255s'"), ti->name);
    debug(dbg_eachfiledetail, "tarobject blockdev");
    newtarobject_allmodes(fnamenewvb.buf, st);
    break;
  case tar_filetype_hardlink:
    varbufreset(&hardlinkfn);
    varbufaddstr(&hardlinkfn,instdir); varbufaddc(&hardlinkfn,'/');
    varbufaddstr(&hardlinkfn, ti->linkname);
    linknode = findnamenode(ti->linkname, 0);
    if (linknode->flags & fnnf_deferred_rename)
      varbufaddstr(&hardlinkfn, DPKGNEWEXT);
    varbufaddc(&hardlinkfn, '\0');
    if (link(hardlinkfn.buf,fnamenewvb.buf))
      ohshite(_("error creating hard link `%.255s'"), ti->name);
    debug(dbg_eachfiledetail, "tarobject hardlink");
    newtarobject_allmodes(fnamenewvb.buf, st);
    break;
  case tar_filetype_symlink:
    /* We've already cheched for an existing directory. */
    if (symlink(ti->linkname, fnamenewvb.buf))
      ohshite(_("error creating symbolic link `%.255s'"), ti->name);
    debug(dbg_eachfiledetail, "tarobject symlink creating");
    if (lchown(fnamenewvb.buf, st->uid, st->gid))
      ohshite(_("error setting ownership of symlink `%.255s'"), ti->name);
    break;
  case tar_filetype_dir:
    /* We've already checked for an existing directory. */
    if (mkdir(fnamenewvb.buf,0))
      ohshite(_("error creating directory `%.255s'"), ti->name);
    debug(dbg_eachfiledetail, "tarobject directory creating");
    newtarobject_allmodes(fnamenewvb.buf, st);
    break;
  default:
    internerr("unknown tar type '%d', but already checked", ti->type);
  }

  set_selinux_path_context(fnamevb.buf, fnamenewvb.buf, st->mode);

  /*
   * CLEANUP: Now we have extracted the new object in .dpkg-new (or,
   * if the file already exists as a directory and we were trying to
   * extract a directory or symlink, we returned earlier, so we don't
   * need to worry about that here).
   *
   * The old file is still in the original filename,
   */

  /* First, check to see if it's a conffile. If so we don't install
   * it now - we leave it in .dpkg-new for --configure to take care of. */
  if (nifd->namenode->flags & fnnf_new_conff) {
    debug(dbg_conffdetail,"tarobject conffile extracted");
    nifd->namenode->flags |= fnnf_elide_other_lists;
    return 0;
  }

  /* Now we move the old file out of the way, the backup file will
   * be deleted later. */
  if (statr) {
    /* Don't try to back it up if it didn't exist. */
    debug(dbg_eachfiledetail,"tarobject new - no backup");
  } else {
    if (ti->type == tar_filetype_dir || S_ISDIR(stab.st_mode)) {
      /* One of the two is a directory - can't do atomic install. */
      debug(dbg_eachfiledetail,"tarobject directory, nonatomic");
      nifd->namenode->flags |= fnnf_no_atomic_overwrite;
      if (rename(fnamevb.buf,fnametmpvb.buf))
        ohshite(_("unable to move aside `%.255s' to install new version"),
                ti->name);
    } else if (S_ISLNK(stab.st_mode)) {
      /* We can't make a symlink with two hardlinks, so we'll have to
       * copy it. (Pretend that making a copy of a symlink is the same
       * as linking to it.) */
      varbufreset(&symlinkfn);
      varbuf_grow(&symlinkfn, stab.st_size + 1);
      r = readlink(fnamevb.buf, symlinkfn.buf, symlinkfn.size);
      if (r < 0)
        ohshite(_("unable to read link `%.255s'"), ti->name);
      assert(r == stab.st_size);
      varbuf_trunc(&symlinkfn, r);
      varbufaddc(&symlinkfn, '\0');
      if (symlink(symlinkfn.buf,fnametmpvb.buf))
        ohshite(_("unable to make backup symlink for `%.255s'"), ti->name);
      if (lchown(fnametmpvb.buf,stab.st_uid,stab.st_gid))
        ohshite(_("unable to chown backup symlink for `%.255s'"), ti->name);
      set_selinux_path_context(fnamevb.buf, fnametmpvb.buf, stab.st_mode);
    } else {
      debug(dbg_eachfiledetail,"tarobject nondirectory, `link' backup");
      if (link(fnamevb.buf,fnametmpvb.buf))
        ohshite(_("unable to make backup link of `%.255s' before installing new version"),
                ti->name);
    }
  }

  /*
   * CLEANUP: Now the old file is in .dpkg-tmp, and the new file is still
   * in .dpkg-new.
   */

  if (ti->type == tar_filetype_file || ti->type == tar_filetype_symlink) {
    nifd->namenode->flags |= fnnf_deferred_rename;

    debug(dbg_eachfiledetail, "tarobject done and installation deferred");
  } else {
    if (rename(fnamenewvb.buf, fnamevb.buf))
      ohshite(_("unable to install new version of `%.255s'"), ti->name);

    /*
     * CLEANUP: Now the new file is in the destination file, and the
     * old file is in .dpkg-tmp to be cleaned up later. We now need
     * to take a different attitude to cleanup, because we need to
     * remove the new file.
     */

    nifd->namenode->flags |= fnnf_placed_on_disk;
    nifd->namenode->flags |= fnnf_elide_other_lists;

    debug(dbg_eachfiledetail, "tarobject done and installed");
  }

  return 0;
}