dpkg/src/archives.c

/*
 * dpkg - main program for package management
 * archives.c - actions that process archive files, mainly unpack
 *
 * Copyright © 1994,1995 Ian Jackson <ian@chiark.greenend.org.uk>
 * Copyright © 2000 Wichert Akkerman <wakkerma@debian.org>
 *
 * This is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2,
 * or (at your option) any later version.
 *
 * This 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
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with dpkg; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <config.h>
#include <compat.h>

#include <dpkg-i18n.h>

#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <utime.h>
#include <assert.h>
#include <time.h>
#include <ctype.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>

#include <obstack.h>
#define obstack_chunk_alloc m_malloc
#define obstack_chunk_free free

#include <dpkg.h>
#include <dpkg-db.h>
#include <tarfn.h>
#include <myopt.h>

#ifdef WITH_SELINUX
#include <selinux/selinux.h>
static int selinux_enabled=-1;
static security_context_t scontext    = NULL;
#endif

#include "filesdb.h"
#include "main.h"
#include "archives.h"

#define MAXCONFLICTORS 20

struct pkginfo *conflictor[MAXCONFLICTORS];
int cflict_index = 0;

/* snprintf(3) doesn't work if format contains %.<nnn>s and an argument has
 * invalid char for locale, then it returns -1.
 * ohshite() is ok, but fd_fd_copy(), which is used in tarobject() in this
 * file, is not ok, because
 * - fd_fd_copy() == buffer_copy_setup() [include/dpkg.h]
 * - buffer_copy_setup() uses varbufvprintf(&v, desc, al); [lib/mlib.c]
 * - varbufvprintf() fails and memory exausted, because it call
 *    fmt = "backend dpkg-deb during `%.255s'
 *    arg may contain some invalid char, for example,
 *    /usr/share/doc/console-tools/examples/unicode/\342\231\252\342\231\254
 *   in console-tools.
 *   In this case, if user uses some locale which doesn't support \342\231...,
 *   vsnprintf() always returns -1 and varbufextend() get called again
 *   and again until memory is exausted and it aborts.
 *
 * So, we need to escape invalid char, probably as in
 * tar-1.13.19/lib/quotearg.c: quotearg_buffer_restyled()
 * but here I escape all 8bit chars, in order to be simple.
 * - ukai@debian.or.jp
 */
static char *
quote_filename(char *buf, int size, char *s)
{
  char *r = buf;

  while (size > 0) {
    switch (*s) {
    case '\0':
      *buf = '\0';
      return r;
    case '\\':
      *buf++ = '\\';
      *buf++ = '\\';
      size -= 2;
      break;
    default:
      if (((*s) & 0x80) == 0) {
        *buf++ = *s++;
        --size;
      } else {
        if (size > 4) {
          sprintf(buf, "\\%03o", *(unsigned char *)s);
          size -= 4;
          buf += 4;
          s++;
        } else {
          /* buffer full */
          *buf = '\0'; /* XXX */
          return r;
        }
      }
    }
  }
  *buf = '\0'; /* XXX */

  return r;
}

/* special routine to handle partial reads from the tarfile */
static int safe_read(int fd, void *buf, int len)
{
  int r, have= 0;
  char *p = (char *)buf;
  while (have < len) {
    if ((r= read(fd,p,len-have))==-1) {
      if (errno==EINTR || errno==EAGAIN) continue;
      return r;
    }
    if (r==0)
      break;
    have+= r;
    p+= r;
  }
  return have;
}

static struct obstack tar_obs;
static int tarobs_init= 0;

/* ensure the obstack is properly initialized */
static void ensureobstackinit(void) {

  if (!tarobs_init) {
    obstack_init(&tar_obs);
    tarobs_init= 1;
  }
}

/* destroy the obstack */
static void destroyobstack(void) {
  if (tarobs_init) {
    obstack_free(&tar_obs, NULL);
    tarobs_init= 0;
  }
}

int filesavespackage(struct fileinlist *file, struct pkginfo *pkgtobesaved,
                     struct pkginfo *pkgbeinginstalled) {
  struct pkginfo *divpkg, *thirdpkg;
  struct filepackages *packageslump;
  int i;
  
  debug(dbg_eachfiledetail,"filesavespackage file `%s' package %s",
        file->namenode->name,pkgtobesaved->name);
  /* 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).
   */
  /* 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 1;
    }
  }
  /* 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 0;
  }
  /* Look for a 3rd package which can take over the file (in case
   * it's a directory which is shared by many packages.
   */
  for (packageslump= file->namenode->packages;
       packageslump;
       packageslump= packageslump->more) {
    for (i=0; i < PERFILEPACKAGESLUMP && packageslump->pkgs[i]; i++) {
      thirdpkg= packageslump->pkgs[i];
      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 0;
    }
  }
  debug(dbg_eachfiledetail, "filesavespackage ... not taken -- save !");
  return 1;
}

void cu_pathname(int argc, void **argv) {
  ensure_pathname_nonexisting((char*)(argv[0]));
} 

int tarfileread(void *ud, char *buf, int len) {
  struct tarcontext *tc= (struct tarcontext*)ud;
  int r;
  if ((r= safe_read(tc->backendpipe,buf,len)) == -1)
    ohshite(_("error reading from dpkg-deb pipe"));
  return r;
}

static void
tarfile_skip_one_forward(struct TarInfo *ti,
                         struct fileinlist **oldnifd,
                         struct fileinlist *nifd)
{
  struct tarcontext *tc = (struct tarcontext *)ti->UserData;
  size_t r;
  char databuf[TARBLKSZ];

  obstack_free(&tar_obs, nifd);
  tc->newfilesp = oldnifd;
  *oldnifd = NULL;

  /* We need to advance the tar file to the next object, so read the
   * file data and set it to oblivion.
   */
  if ((ti->Type == NormalFile0) || (ti->Type == NormalFile1)) {
    char fnamebuf[256];

    fd_null_copy(tc->backendpipe, ti->Size,
                 _("skipped unpacking file '%.255s' (replaced or excluded?)"),
                 quote_filename(fnamebuf, 256, ti->Name));
    r = ti->Size % TARBLKSZ;
    if (r > 0)
      r = safe_read(tc->backendpipe, databuf, TARBLKSZ - r);
  }
}

int fnameidlu;
struct varbuf fnamevb;
struct varbuf fnametmpvb;
struct varbuf fnamenewvb;
struct pkg_deconf_list *deconfigure = NULL;

static time_t currenttime;

static int does_replace(struct pkginfo *newpigp,
                          struct pkginfoperfile *newpifp,
                          struct pkginfo *oldpigp) {
  struct dependency *dep;
  
  debug(dbg_depcon,"does_replace new=%s old=%s (%s)",newpigp->name,
        oldpigp->name,versiondescribe(&oldpigp->installed.version,
                                      vdew_always));
  for (dep= newpifp->depends; dep; dep= dep->next) {
    if (dep->type != dep_replaces || dep->list->ed != oldpigp) continue;
    debug(dbg_depcondetail,"does_replace ... found old, version %s",
          versiondescribe(&dep->list->version,vdew_always));
    if (!versionsatisfied(&oldpigp->installed,dep->list)) continue;
    debug(dbg_depcon,"does_replace ... yes");
    return 1;
  }
  debug(dbg_depcon,"does_replace ... no");
  return 0;
}

static void newtarobject_utime(const char *path, struct TarInfo *ti) {
  struct utimbuf utb;
  utb.actime= currenttime;
  utb.modtime= ti->ModTime;
  if (utime(path,&utb))
    ohshite(_("error setting timestamps of `%.255s'"),ti->Name);
}

static void newtarobject_allmodes(const char *path, struct TarInfo *ti, struct filestatoverride* statoverride) {
  if (chown(path,
	    statoverride ? statoverride->uid : ti->UserID,
	    statoverride ? statoverride->gid : ti->GroupID))
    ohshite(_("error setting ownership of `%.255s'"),ti->Name);
  if (chmod(path,(statoverride ? statoverride->mode : ti->Mode) & ~S_IFMT))
    ohshite(_("error setting permissions of `%.255s'"),ti->Name);
  newtarobject_utime(path,ti);
}

void setupfnamevbs(const char *filename) {
  fnamevb.used= fnameidlu;
  varbufaddstr(&fnamevb,filename);
  varbufaddc(&fnamevb,0);

  fnametmpvb.used= fnameidlu;
  varbufaddstr(&fnametmpvb,filename);
  varbufaddstr(&fnametmpvb,DPKGTEMPEXT);
  varbufaddc(&fnametmpvb,0);

  fnamenewvb.used= fnameidlu;
  varbufaddstr(&fnamenewvb,filename);
  varbufaddstr(&fnamenewvb,DPKGNEWEXT);
  varbufaddc(&fnamenewvb,0);

  debug(dbg_eachfiledetail, "setupvnamevbs main=`%s' tmp=`%s' new=`%s'",
        fnamevb.buf, fnametmpvb.buf, fnamenewvb.buf);
}

int unlinkorrmdir(const char *filename) {
  /* Returns 0 on success or -1 on failure, just like unlink & rmdir */
  int r, e;
  
  if (!rmdir(filename)) {
    debug(dbg_eachfiledetail,"unlinkorrmdir `%s' rmdir OK",filename);
    return 0;
  }
  
  if (errno != ENOTDIR) {
    e= errno;
    debug(dbg_eachfiledetail,"unlinkorrmdir `%s' rmdir %s",filename,strerror(e));
    errno= e; return -1;
  }
  
  r= unlink(filename); e= errno;
  debug(dbg_eachfiledetail,"unlinkorrmdir `%s' unlink %s",
        filename, r ? strerror(e) : "OK");
  errno= e; return r;
}

struct fileinlist *addfiletolist(struct tarcontext *tc,
				 struct filenamenode *namenode) {
  struct fileinlist *nifd;
  
  nifd= obstack_alloc(&tar_obs, sizeof(struct fileinlist));
  nifd->namenode= namenode;
  nifd->next = NULL;
  *tc->newfilesp = nifd;
  tc->newfilesp = &nifd->next;
  return nifd;
}

static int linktosameexistingdir(const struct TarInfo *ti,
                                 const char *fname,
                                 struct varbuf *symlinkfn) {
  struct stat oldstab, newstab;
  int statr;
  const char *lastslash;

  statr= stat(fname, &oldstab);
  if (statr) {
    if (!(errno == ENOENT || errno == ELOOP || errno == ENOTDIR))
      ohshite(_("failed to stat (dereference) existing symlink `%.250s'"),
              fname);
    return 0;
  }
  if (!S_ISDIR(oldstab.st_mode)) return 0;

  /* But is it to the same dir ? */
  varbufreset(symlinkfn);
  if (ti->LinkName[0] == '/') {
    varbufaddstr(symlinkfn, instdir);
  } else {
    lastslash= strrchr(fname, '/');
    assert(lastslash);
    varbufaddbuf(symlinkfn, fname, (lastslash - fname) + 1);
  }
  varbufaddstr(symlinkfn, ti->LinkName);
  varbufaddc(symlinkfn, 0);

  statr= stat(symlinkfn->buf, &newstab);
  if (statr) {
    if (!(errno == ENOENT || errno == ELOOP || errno == ENOTDIR))
      ohshite(_("failed to stat (dereference) proposed new symlink target"
                " `%.250s' for symlink `%.250s'"), symlinkfn->buf, fname);
    return 0;
  }
  if (!S_ISDIR(newstab.st_mode)) return 0;
  if (newstab.st_dev != oldstab.st_dev ||
      newstab.st_ino != oldstab.st_ino) return 0;
  return 1;
}

int tarobject(struct TarInfo *ti) {
  static struct varbuf conffderefn, hardlinkfn, symlinkfn;
  static int fd;
  const char *usename;
  struct filenamenode *usenode;

  struct conffile *conff;
  struct tarcontext *tc= (struct tarcontext*)ti->UserData;
  int statr, i, existingdirectory, keepexisting;
  ssize_t r;
  struct stat stab, stabtmp;
  char databuf[TARBLKSZ];
  struct fileinlist *nifd, **oldnifd;
  struct pkginfo *divpkg, *otherpkg;
  struct filepackages *packageslump;
  mode_t am;

  ensureobstackinit();

  /* Append to list of files.
   * The trailing / put on the end of names in tarfiles has already
   * been stripped by TarExtractor (lib/tarfn.c).
   */
  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->Mode, (unsigned)ti->UserID, (unsigned)ti->GroupID, ti->Type,
        ti->Type == '\0' ? '_' :
        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);
    }
  }

  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 (ie, 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= 0;
  switch (ti->Type) {
  case SymbolicLink:
    /* If it's already an existing directory, do nothing. */
    if (!statr && S_ISDIR(stab.st_mode)) {
      debug(dbg_eachfiledetail,"tarobject SymbolicLink exists as directory");
      existingdirectory= 1;
    } else if (!statr && S_ISLNK(stab.st_mode)) {
      if (linktosameexistingdir(ti, fnamevb.buf, &symlinkfn))
        existingdirectory= 1;
    }
    break;
  case Directory:
    /* 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= 1;
    }
    break;
  case NormalFile0: case NormalFile1:
  case CharacterDevice: case BlockDevice: case FIFO:
  case HardLink:
    break;
  default:
    ohshit(_("archive contained object `%.255s' of unknown type 0x%x"),ti->Name,ti->Type);
  }

  keepexisting= 0;
  if (!existingdirectory) {
    for (packageslump= nifd->namenode->packages;
         packageslump;
         packageslump= packageslump->more) {
      for (i=0; i < PERFILEPACKAGESLUMP && packageslump->pkgs[i]; i++) {
        otherpkg= packageslump->pkgs[i];
        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= 1;
	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");
	    /* processarc.c will have copied its hash already. */
	    continue;
	}

        if (does_replace(tc->pkg,&tc->pkg->available,otherpkg)) {
          printf(_("Replacing files in old package %s ...\n"),otherpkg->name);
          otherpkg->clientdata->replacingfilesandsaid= 1;
	} else if (does_replace(otherpkg,&otherpkg->installed,tc->pkg)) {
	  printf(_("Replaced by files in installed package %s ...\n"),
		 otherpkg->name);
          otherpkg->clientdata->replacingfilesandsaid= 2;
	  keepexisting = 1;
        } else {
          if (!statr && S_ISDIR(stab.st_mode)) {
            forcibleerr(fc_overwritedir, _("trying to overwrite directory `%.250s' "
                        "in package %.250s with nondirectory"),
                        nifd->namenode->name,otherpkg->name);
          } else {
            /* WTA: 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==Directory))
              forcibleerr(fc_overwrite,
                        _("trying to overwrite `%.250s', which is also in package %.250s"),
                        nifd->namenode->name,otherpkg->name);
          }
        }
      }
    }
  }
       
  /* 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);

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

  /* 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.
   */

#ifdef WITH_SELINUX
  /* Set selinux_enabled if it is not already set (singleton) */
  if (selinux_enabled < 0)
    selinux_enabled = (is_selinux_enabled() > 0);

  /* Since selinux is enabled, try and set the context */
  if (selinux_enabled > 0) {
    /*
     * well, we could use
     *   void set_matchpathcon_printf(void (*f)(const char *fmt, ...));
     * to redirect the errors from the following bit, but that
     * seems too much effort.
     */

    /*
     * Do nothing if we can't figure out what the context is,
     * or if it has no context; in which case the default
     * context shall be applied.
     */
    if( ! ((matchpathcon(fnamevb.buf,
                         (nifd->namenode->statoverride ?
                          nifd->namenode->statoverride->mode : ti->Mode)
                         & ~S_IFMT, &scontext) != 0) ||
           (strcmp(scontext, "<<none>>") == 0)))
     {
       if(setfscreatecon(scontext) < 0)
	 perror("Error setting security context for file object:");
     }
  }
#endif /* WITH_SELINUX */


  /* Extract whatever it is as .dpkg-new ... */
  switch (ti->Type) {
  case NormalFile0: case NormalFile1:
    /* 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 NormalFile[01] open size=%lu",
          (unsigned long)ti->Size);
    { char fnamebuf[256];
    fd_fd_copy(tc->backendpipe, fd, ti->Size, _("backend dpkg-deb during `%.255s'"),quote_filename(fnamebuf,256,ti->Name));
    }
    r= ti->Size % TARBLKSZ;
    if (r > 0) r= safe_read(tc->backendpipe,databuf,TARBLKSZ - r);
    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,
	    nifd->namenode->statoverride ? nifd->namenode->statoverride->uid : ti->UserID,
	    nifd->namenode->statoverride ? nifd->namenode->statoverride->gid : ti->GroupID))
      ohshite(_("error setting ownership of `%.255s'"),ti->Name);
    am=(nifd->namenode->statoverride ? nifd->namenode->statoverride->mode : ti->Mode) & ~S_IFMT;
    if (fchmod(fd,am))
      ohshite(_("error setting permissions of `%.255s'"),ti->Name);
    pop_cleanup(ehflag_normaltidy); /* fd= open(fnamenewvb.buf) */
    if (close(fd))
      ohshite(_("error closing/writing `%.255s'"),ti->Name);
    newtarobject_utime(fnamenewvb.buf,ti);
    break;
  case FIFO:
    if (mkfifo(fnamenewvb.buf,0))
      ohshite(_("error creating pipe `%.255s'"),ti->Name);
    debug(dbg_eachfiledetail,"tarobject FIFO");
    newtarobject_allmodes(fnamenewvb.buf,ti, nifd->namenode->statoverride);
    break;
  case CharacterDevice:
    if (mknod(fnamenewvb.buf,S_IFCHR, ti->Device))
      ohshite(_("error creating device `%.255s'"),ti->Name);
    debug(dbg_eachfiledetail,"tarobject CharacterDevice");
    newtarobject_allmodes(fnamenewvb.buf,ti, nifd->namenode->statoverride);
    break; 
  case BlockDevice:
    if (mknod(fnamenewvb.buf,S_IFBLK, ti->Device))
      ohshite(_("error creating device `%.255s'"),ti->Name);
    debug(dbg_eachfiledetail,"tarobject BlockDevice");
    newtarobject_allmodes(fnamenewvb.buf,ti, nifd->namenode->statoverride);
    break; 
  case HardLink:
    varbufreset(&hardlinkfn);
    varbufaddstr(&hardlinkfn,instdir); varbufaddc(&hardlinkfn,'/');
    varbufaddstr(&hardlinkfn,ti->LinkName); 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,ti, nifd->namenode->statoverride);
    break;
  case SymbolicLink:
    /* 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 SymbolicLink creating");
#ifdef HAVE_LCHOWN
    if (lchown(fnamenewvb.buf,
	    nifd->namenode->statoverride ? nifd->namenode->statoverride->uid : ti->UserID,
	    nifd->namenode->statoverride ? nifd->namenode->statoverride->gid : ti->GroupID))
      ohshite(_("error setting ownership of symlink `%.255s'"),ti->Name);
#else
    if (chown(fnamenewvb.buf,
	    nifd->namenode->statoverride ? nifd->namenode->statoverride->uid : ti->UserID,
	    nifd->namenode->statoverride ? nifd->namenode->statoverride->gid : ti->GroupID))
      ohshite(_("error setting ownership of symlink `%.255s'"),ti->Name);
#endif
    break;
  case Directory:
    /* 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,ti,nifd->namenode->statoverride);
    break;
  default:
    internerr("unknown tar type '%d', but already checked", ti->Type);
  }
  /* 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 == Directory || 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);
      do {
        varbufextend(&symlinkfn);
        r= readlink(fnamevb.buf,symlinkfn.buf,symlinkfn.size);
        if (r<0) ohshite(_("unable to read link `%.255s'"),ti->Name);
      } while ((size_t)r == symlinkfn.size);
      symlinkfn.used= r; varbufaddc(&symlinkfn,0);
      if (symlink(symlinkfn.buf,fnametmpvb.buf))
        ohshite(_("unable to make backup symlink for `%.255s'"),ti->Name);
#ifdef HAVE_LCHOWN
      if (lchown(fnametmpvb.buf,stab.st_uid,stab.st_gid))
        ohshite(_("unable to chown backup symlink for `%.255s'"),ti->Name);
#else
      if (chown(fnametmpvb.buf,stab.st_uid,stab.st_gid))
        ohshite(_("unable to chown backup symlink for `%.255s'"),ti->Name);
#endif
    } 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.
   */

#ifdef WITH_SELINUX
  /*
   * if selinux is enabled, try and set the default security context
   * for the renamed file
   */
  if (selinux_enabled > 0)
    if(scontext) {
       if(setfscreatecon(scontext) < 0)
         perror("Error setting security context for next file object:");
       freecon(scontext);
       scontext = NULL;
     }
        
#endif /* WITH_SELINUX */

  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;

#ifdef WITH_SELINUX
  /*
   * if selinux is enabled, restore the default security context
   */
  if (selinux_enabled > 0)
    if(setfscreatecon(NULL) < 0)
      perror("Error restoring default security context:");
#endif /* WITH_SELINUX */


  nifd->namenode->flags |= fnnf_elide_other_lists;

  debug(dbg_eachfiledetail,"tarobject done and installed");
  return 0;
}

static int try_deconfigure_can(int (*force_p)(struct deppossi*),
                               struct pkginfo *pkg,
                               struct deppossi *pdep,
                               const char *action,
                               struct pkginfo *removal,
                          const char *why) {
  /* Also checks whether the pdep is forced, first, according to force_p.
   * force_p may be 0 in which case nothing is considered forced.
   *
   * Action is a string describing the action which causes the
   * deconfiguration:
   *     removal of <package>         (due to Conflicts+Depends   removal!=0)
   *     installation of <package>    (due to Breaks              removal==0)
   *
   * Return values:  2: forced (no deconfiguration needed, why is printed)
   *                 1: deconfiguration queued ok (no message printed)
   *                 0: not possible (why is printed)
   */
  struct pkg_deconf_list *newdeconf;
  
  if (force_p && force_p(pdep)) {
    warning(_("ignoring dependency problem with %s:\n%s"), action, why);
    return 2;
  } else if (f_autodeconf) {
    if (pkg->installed.essential) {
      if (fc_removeessential) {
        warning(_("considering deconfiguration of essential\n"
                  " package %s, to enable %s."), pkg->name, action);
      } else {
        fprintf(stderr, _("dpkg: no, %s is essential, will not deconfigure\n"
                          " it in order to enable %s.\n"),
                pkg->name, action);
        return 0;
      }
    }
    pkg->clientdata->istobe= itb_deconfigure;
    newdeconf = m_malloc(sizeof(struct pkg_deconf_list));
    newdeconf->next= deconfigure;
    newdeconf->pkg= pkg;
    newdeconf->pkg_removal = removal;
    deconfigure= newdeconf;
    return 1;
  } else {
    fprintf(stderr, _("dpkg: no, cannot proceed with %s (--auto-deconfigure will help):\n%s"),
            action, why);
    return 0;
  }
}

static int try_remove_can(struct deppossi *pdep,
                          struct pkginfo *fixbyrm,
                          const char *why) {
  char action[512];
  sprintf(action, _("removal of %.250s"), fixbyrm->name);
  return try_deconfigure_can(force_depends, pdep->up->up, pdep,
                             action, fixbyrm, why);
}

void check_breaks(struct dependency *dep, struct pkginfo *pkg,
                  const char *pfilename) {
  struct pkginfo *fixbydeconf;
  struct varbuf why = VARBUF_INIT;
  int ok;

  fixbydeconf = NULL;
  if (depisok(dep, &why, &fixbydeconf, 0)) {
    varbuffree(&why);
    return;
  }

  varbufaddc(&why, 0);

  if (fixbydeconf && f_autodeconf) {
    char action[512];

    ensure_package_clientdata(fixbydeconf);
    assert(fixbydeconf->clientdata->istobe == itb_normal);

    sprintf(action, _("installation of %.250s"), pkg->name);
    fprintf(stderr, _("dpkg: considering deconfiguration of %s,"
                      " which would be broken by %s ...\n"),
            fixbydeconf->name, action);

    ok= try_deconfigure_can(force_breaks, fixbydeconf, dep->list,
                            action, NULL, why.buf);
    if (ok == 1) {
      fprintf(stderr, _("dpkg: yes, will deconfigure %s (broken by %s).\n"),
              fixbydeconf->name, pkg->name);
    }
  } else {
    fprintf(stderr, _("dpkg: regarding %s containing %s:\n%s"),
            pfilename, pkg->name, why.buf);
    ok= 0;
  }
  varbuffree(&why);
  if (ok > 0) return;

  if (force_breaks(dep->list)) {
    warning(_("ignoring breakage, may proceed anyway!"));
    return;
  }

  if (fixbydeconf && !f_autodeconf) {
    ohshit(_("installing %.250s would break %.250s, and\n"
             " deconfiguration is not permitted (--auto-deconfigure might help)"),
           pkg->name, fixbydeconf->name);
  } else {
    ohshit(_("installing %.250s would break existing software"),
           pkg->name);
  }
}

void check_conflict(struct dependency *dep, struct pkginfo *pkg,
                    const char *pfilename) {
  struct pkginfo *fixbyrm;
  struct deppossi *pdep, flagdeppossi;
  struct varbuf conflictwhy = VARBUF_INIT, removalwhy = VARBUF_INIT;
  struct dependency *providecheck;

  fixbyrm = NULL;
  if (depisok(dep, &conflictwhy, &fixbyrm, 0)) {
    varbuffree(&conflictwhy);
    varbuffree(&removalwhy);
    return;
  }
  if (fixbyrm) {
    ensure_package_clientdata(fixbyrm);
    if (fixbyrm->clientdata->istobe == itb_installnew) {
      fixbyrm= dep->up;
      ensure_package_clientdata(fixbyrm);
    }
    if (((pkg->available.essential && fixbyrm->installed.essential) ||
         (((fixbyrm->want != want_install && fixbyrm->want != want_hold) ||
           does_replace(pkg,&pkg->available,fixbyrm)) &&
          (!fixbyrm->installed.essential || fc_removeessential)))) {
      assert(fixbyrm->clientdata->istobe == itb_normal || fixbyrm->clientdata->istobe == itb_deconfigure);
      fixbyrm->clientdata->istobe= itb_remove;
      fprintf(stderr, _("dpkg: considering removing %s in favour of %s ...\n"),
              fixbyrm->name, pkg->name);
      if (!(fixbyrm->status == stat_installed ||
            fixbyrm->status == stat_triggerspending ||
            fixbyrm->status == stat_triggersawaited)) {
        fprintf(stderr,
                _("%s is not properly installed - ignoring any dependencies on it.\n"),
                fixbyrm->name);
        pdep = NULL;
      } else {
        for (pdep= fixbyrm->installed.depended;
             pdep;
             pdep= pdep->nextrev) {
          if (pdep->up->type != dep_depends && pdep->up->type != dep_predepends)
            continue;
          if (depisok(pdep->up, &removalwhy, NULL, 0))
            continue;
          varbufaddc(&removalwhy,0);
          if (!try_remove_can(pdep,fixbyrm,removalwhy.buf))
            break;
        }
        if (!pdep) {
          /* If we haven't found a reason not to yet, let's look some more. */
          for (providecheck= fixbyrm->installed.depends;
               providecheck;
               providecheck= providecheck->next) {
            if (providecheck->type != dep_provides) continue;
            for (pdep= providecheck->list->ed->installed.depended;
                 pdep;
                 pdep= pdep->nextrev) {
              if (pdep->up->type != dep_depends && pdep->up->type != dep_predepends)
                continue;
              if (depisok(pdep->up, &removalwhy, NULL, 0))
                continue;
              varbufaddc(&removalwhy,0);
              fprintf(stderr, _("dpkg"
                      ": may have trouble removing %s, as it provides %s ...\n"),
                      fixbyrm->name, providecheck->list->ed->name);
              if (!try_remove_can(pdep,fixbyrm,removalwhy.buf))
                goto break_from_both_loops_at_once;
            }
          }
        break_from_both_loops_at_once:;
        }
      }
      if (!pdep && skip_due_to_hold(fixbyrm)) {
        pdep= &flagdeppossi;
      }
      if (!pdep && (fixbyrm->eflag & eflagf_reinstreq)) {
        if (fc_removereinstreq) {
          fprintf(stderr, _("dpkg: package %s requires reinstallation, but will"
                  " remove anyway as you request.\n"), fixbyrm->name);
        } else {
          fprintf(stderr, _("dpkg: package %s requires reinstallation, "
                  "will not remove.\n"), fixbyrm->name);
          pdep= &flagdeppossi;
        }
      }
      if (!pdep) {
	if (cflict_index >= MAXCONFLICTORS)
	  ohshit(_("package %s has too many Conflicts/Replaces pairs"),
		 pkg->name);

        /* This conflict is OK - we'll remove the conflictor. */
	conflictor[cflict_index++]= fixbyrm;
        varbuffree(&conflictwhy); varbuffree(&removalwhy);
        fprintf(stderr, _("dpkg: yes, will remove %s in favour of %s.\n"),
                fixbyrm->name, pkg->name);
        return;
      }
      fixbyrm->clientdata->istobe= itb_normal; /* put it back */
    }
  }
  varbufaddc(&conflictwhy,0);
  fprintf(stderr, _("dpkg: regarding %s containing %s:\n%s"),
          pfilename, pkg->name, conflictwhy.buf);
  if (!force_conflicts(dep->list))
    ohshit(_("conflicting packages - not installing %.250s"),pkg->name);
  warning(_("ignoring conflict, may proceed anyway!"));
  varbuffree(&conflictwhy);
  
  return;
}

void cu_cidir(int argc, void **argv) {
  char *cidir= (char*)argv[0];
  char *cidirrest= (char*)argv[1];
  cidirrest[-1]= 0;
  ensure_pathname_nonexisting(cidir);
}  

void cu_fileslist(int argc, void **argv) {
  destroyobstack();
}  

void archivefiles(const char *const *argv) {
  const char *volatile thisarg;
  const char *const *volatile argp;
  jmp_buf ejbuf;
  int pi[2], fc, nfiles, c, i, r;
  FILE *pf;
  static struct varbuf findoutput;
  const char **arglist;
  char *p;

  trigproc_install_hooks();

  modstatdb_init(admindir,
                 f_noact ?                     msdbrw_readonly
               : cipaction->arg == act_avail ? msdbrw_write
               : fc_nonroot ?                  msdbrw_write
               :                               msdbrw_needsuperuser);

  checkpath();
  log_message("startup archives %s", cipaction->olong);
  
  if (f_recursive) {
    
    if (!*argv)
      badusage(_("--%s --recursive needs at least one path argument"),cipaction->olong);
    
    m_pipe(pi);
    if (!(fc= m_fork())) {
      const char *const *ap;
      int i;
      m_dup2(pi[1],1); close(pi[0]); close(pi[1]);
      for (i=0, ap=argv; *ap; ap++, i++);
      arglist = m_malloc(sizeof(char *) * (i + 15));
      arglist[0] = FIND;
      for (i=1, ap=argv; *ap; ap++, i++) {
        if (strchr(FIND_EXPRSTARTCHARS,(*ap)[0])) {
          char *a;
          a= m_malloc(strlen(*ap)+10);
          strcpy(a,"./");
          strcat(a,*ap);
          arglist[i] = a;
        } else {
          arglist[i] = (const char *)*ap;
        }
      }
      /* When editing these, make sure that arglist is malloced big enough,
       * above.
       */
      arglist[i++] = "-follow";
      arglist[i++] = "-name";
      arglist[i++] = ARCHIVE_FILENAME_PATTERN;
      arglist[i++] = "-type";
      arglist[i++] = "f";
      arglist[i++] = "-print0";
      arglist[i++] = NULL;
      execvp(FIND, (char *const *)arglist);
      ohshite(_("failed to exec find for --recursive"));
    }
    close(pi[1]);

    nfiles= 0;
    pf= fdopen(pi[0],"r");  if (!pf) ohshite(_("failed to fdopen find's pipe"));
    varbufreset(&findoutput);
    while ((c= fgetc(pf)) != EOF) {
      varbufaddc(&findoutput,c);
      if (!c) nfiles++;
    }
    if (ferror(pf)) ohshite(_("error reading find's pipe"));
    if (fclose(pf)) ohshite(_("error closing find's pipe"));
    r= waitsubproc(fc,"find",PROCNOERR);
    if(!(r==0 || r==1))
      ohshit(_("find for --recursive returned unhandled error %i"),r);

    if (!nfiles)
      ohshit(_("searched, but found no packages (files matching *.deb)"));

    varbufaddc(&findoutput,0);
    varbufaddc(&findoutput,0);
    
    arglist= m_malloc(sizeof(char*)*(nfiles+1));
    p= findoutput.buf; i=0;
    while (*p) {
      arglist[i++]= p;
      while ((c= *p++) != 0);
    }
    arglist[i] = NULL;
    argp= arglist;

  } else {

    if (!*argv) badusage(_("--%s needs at least one package archive file argument"),
                         cipaction->olong);
    argp= argv;
    
  }

  currenttime = time(NULL);

  /* Initialize fname variables contents. */

  varbufreset(&fnamevb);
  varbufreset(&fnametmpvb);
  varbufreset(&fnamenewvb);

  varbufaddstr(&fnamevb,instdir); varbufaddc(&fnamevb,'/');
  varbufaddstr(&fnametmpvb,instdir); varbufaddc(&fnametmpvb,'/');
  varbufaddstr(&fnamenewvb,instdir); varbufaddc(&fnamenewvb,'/');
  fnameidlu= fnamevb.used;

  ensure_diversions();
  ensure_statoverrides();
  
  while ((thisarg = *argp++) != NULL) {
    if (setjmp(ejbuf)) {
      error_unwind(ehflag_bombout);
      if (abort_processing)
        break;
      continue;
    }
    push_error_handler(&ejbuf,print_error_perpackage,thisarg);
    process_archive(thisarg);
    onerr_abort++;
    if (ferror(stdout)) werr("stdout");
    if (ferror(stderr)) werr("stderr");
    onerr_abort--;
    set_error_display(NULL, NULL);
    error_unwind(ehflag_normaltidy);
  }

  switch (cipaction->arg) {
  case act_install:
  case act_configure:
  case act_triggers:
  case act_remove:
  case act_purge:
    process_queue();
  case act_unpack:
  case act_avail:
    break;
  default:
    internerr("unknown action '%d'", cipaction->arg);
  }

  trigproc_run_deferred();
  modstatdb_shutdown();
}

int wanttoinstall(struct pkginfo *pkg, const struct versionrevision *ver, int saywhy) {
  /* Decide whether we want to install a new version of the package.
   * ver is the version we might want to install.  If saywhy is 1 then
   * if we skip the package we say what we are doing (and, if we are
   * selecting a previously deselected package, say so and actually do
   * the select).  want_install returns 0 if the package should be
   * skipped and 1 if it should be installed.
   *
   * ver may be 0, in which case saywhy must be 0 and want_install may
   * also return -1 to mean it doesn't know because it would depend on
   * the version number.
   */
  int r;

  if (pkg->want != want_install && pkg->want != want_hold) {
    if (f_alsoselect) {
      if (saywhy) {
   printf(_("Selecting previously deselected package %s.\n"),pkg->name);
   pkg->want= want_install;
      }
      return 1;
    } else {
      if (saywhy) printf(_("Skipping deselected package %s.\n"),pkg->name);
      return 0;
    }
  }

  if (!(pkg->status == stat_installed ||
        pkg->status == stat_triggersawaited ||
        pkg->status == stat_triggerspending))
    return 1;
  if (!ver) return -1;

  r= versioncompare(ver,&pkg->installed.version);
  if (r > 0) {
    return 1;
  } else if (r == 0) {
    /* Same version fully installed. */
    if (f_skipsame) {
      if (saywhy) fprintf(stderr, _("Version %.250s of %.250s already installed, "
             "skipping.\n"),
             versiondescribe(&pkg->installed.version, vdew_nonambig),
             pkg->name);
      return 0;
    } else {
      return 1;
    }
  } else {
    if (fc_downgrade) {
      if (saywhy)
        warning(_("downgrading %.250s from %.250s to %.250s."), pkg->name,
             versiondescribe(&pkg->installed.version, vdew_nonambig),
             versiondescribe(&pkg->available.version, vdew_nonambig));
      return 1;
    } else {
      if (saywhy) fprintf(stderr, _("Will not downgrade %.250s from version %.250s "
             "to %.250s, skipping.\n"), pkg->name,
             versiondescribe(&pkg->installed.version, vdew_nonambig),
             versiondescribe(&pkg->available.version, vdew_nonambig));
      return 0;
    }
  }
}

struct fileinlist *newconff_append(struct fileinlist ***newconffileslastp_io,
				   struct filenamenode *namenode) {
  struct fileinlist *newconff;

  newconff= m_malloc(sizeof(struct fileinlist));
  newconff->next = NULL;
  newconff->namenode= namenode;
  **newconffileslastp_io= newconff;
  *newconffileslastp_io= &newconff->next;
  return newconff;
}

/* vi: ts=8 sw=2
 */