path: root/lib/libalpm/remove.c

/*
 *  remove.c
 *
 *  Copyright (c) 2006-2011 Pacman Development Team <pacman-dev@archlinux.org>
 *  Copyright (c) 2002-2006 by Judd Vinet <jvinet@zeroflux.org>
 *  Copyright (c) 2005 by Aurelien Foret <orelien@chez.com>
 *  Copyright (c) 2005 by Christian Hamar <krics@linuxforum.hu>
 *  Copyright (c) 2006 by David Kimpe <dnaku@frugalware.org>
 *  Copyright (c) 2005, 2006 by Miklos Vajna <vmiklos@frugalware.org>
 *
 *  This program 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 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <limits.h>
#include <unistd.h>
#include <sys/stat.h>

/* libalpm */
#include "remove.h"
#include "alpm_list.h"
#include "alpm.h"
#include "trans.h"
#include "util.h"
#include "log.h"
#include "backup.h"
#include "package.h"
#include "db.h"
#include "deps.h"
#include "handle.h"

int SYMEXPORT alpm_remove_pkg(alpm_handle_t *handle, alpm_pkg_t *pkg)
{
  const char *pkgname;
  alpm_trans_t *trans;

  /* Sanity checks */
  CHECK_HANDLE(handle, return -1);
  ASSERT(pkg != NULL, RET_ERR(handle, PM_ERR_WRONG_ARGS, -1));
  ASSERT(handle == pkg->handle, RET_ERR(handle, PM_ERR_WRONG_ARGS, -1));
  trans = handle->trans;
  ASSERT(trans != NULL, RET_ERR(handle, PM_ERR_TRANS_NULL, -1));
  ASSERT(trans->state == STATE_INITIALIZED,
      RET_ERR(handle, PM_ERR_TRANS_NOT_INITIALIZED, -1));

  pkgname = pkg->name;

  if(_alpm_pkg_find(trans->remove, pkgname)) {
    RET_ERR(handle, PM_ERR_TRANS_DUP_TARGET, -1);
  }

  _alpm_log(handle, PM_LOG_DEBUG, "adding package %s to the transaction remove list\n",
      pkgname);
  trans->remove = alpm_list_add(trans->remove, _alpm_pkg_dup(pkg));
  return 0;
}

static void remove_prepare_cascade(alpm_handle_t *handle, alpm_list_t *lp)
{
  alpm_trans_t *trans = handle->trans;

  while(lp) {
    alpm_list_t *i;
    for(i = lp; i; i = i->next) {
      alpm_depmissing_t *miss = (alpm_depmissing_t *)i->data;
      alpm_pkg_t *info = _alpm_db_get_pkgfromcache(handle->db_local, miss->target);
      if(info) {
        if(!_alpm_pkg_find(trans->remove, alpm_pkg_get_name(info))) {
          _alpm_log(handle, PM_LOG_DEBUG, "pulling %s in target list\n",
              alpm_pkg_get_name(info));
          trans->remove = alpm_list_add(trans->remove, _alpm_pkg_dup(info));
        }
      } else {
        _alpm_log(handle, PM_LOG_ERROR, _("could not find %s in database -- skipping\n"),
                  miss->target);
      }
    }
    alpm_list_free_inner(lp, (alpm_list_fn_free)_alpm_depmiss_free);
    alpm_list_free(lp);
    lp = alpm_checkdeps(handle, _alpm_db_get_pkgcache(handle->db_local),
        trans->remove, NULL, 1);
  }
}

static void remove_prepare_keep_needed(alpm_handle_t *handle, alpm_list_t *lp)
{
  alpm_trans_t *trans = handle->trans;

  /* Remove needed packages (which break dependencies) from target list */
  while(lp != NULL) {
    alpm_list_t *i;
    for(i = lp; i; i = i->next) {
      alpm_depmissing_t *miss = (alpm_depmissing_t *)i->data;
      void *vpkg;
      alpm_pkg_t *pkg = _alpm_pkg_find(trans->remove, miss->causingpkg);
      if(pkg == NULL) {
        continue;
      }
      trans->remove = alpm_list_remove(trans->remove, pkg, _alpm_pkg_cmp,
          &vpkg);
      pkg = vpkg;
      if(pkg) {
        _alpm_log(handle, PM_LOG_WARNING, _("removing %s from target list\n"),
            alpm_pkg_get_name(pkg));
        _alpm_pkg_free(pkg);
      }
    }
    alpm_list_free_inner(lp, (alpm_list_fn_free)_alpm_depmiss_free);
    alpm_list_free(lp);
    lp = alpm_checkdeps(handle, _alpm_db_get_pkgcache(handle->db_local),
        trans->remove, NULL, 1);
  }
}

/** Transaction preparation for remove actions.
 * This functions takes a pointer to a alpm_list_t which will be
 * filled with a list of alpm_depmissing_t* objects representing
 * the packages blocking the transaction.
 * @param handle the context handle
 * @param data a pointer to an alpm_list_t* to fill
 */
int _alpm_remove_prepare(alpm_handle_t *handle, alpm_list_t **data)
{
  alpm_list_t *lp;
  alpm_trans_t *trans = handle->trans;
  alpm_db_t *db = handle->db_local;

  if((trans->flags & PM_TRANS_FLAG_RECURSE) && !(trans->flags & PM_TRANS_FLAG_CASCADE)) {
    _alpm_log(handle, PM_LOG_DEBUG, "finding removable dependencies\n");
    _alpm_recursedeps(db, trans->remove,
        trans->flags & PM_TRANS_FLAG_RECURSEALL);
  }

  if(!(trans->flags & PM_TRANS_FLAG_NODEPS)) {
    EVENT(trans, PM_TRANS_EVT_CHECKDEPS_START, NULL, NULL);

    _alpm_log(handle, PM_LOG_DEBUG, "looking for unsatisfied dependencies\n");
    lp = alpm_checkdeps(handle, _alpm_db_get_pkgcache(db), trans->remove, NULL, 1);
    if(lp != NULL) {

      if(trans->flags & PM_TRANS_FLAG_CASCADE) {
        remove_prepare_cascade(handle, lp);
      } else if(trans->flags & PM_TRANS_FLAG_UNNEEDED) {
        /* Remove needed packages (which would break dependencies)
         * from target list */
        remove_prepare_keep_needed(handle, lp);
      } else {
        if(data) {
          *data = lp;
        } else {
          alpm_list_free_inner(lp, (alpm_list_fn_free)_alpm_depmiss_free);
          alpm_list_free(lp);
        }
        RET_ERR(handle, PM_ERR_UNSATISFIED_DEPS, -1);
      }
    }
  }

  /* re-order w.r.t. dependencies */
  _alpm_log(handle, PM_LOG_DEBUG, "sorting by dependencies\n");
  lp = _alpm_sortbydeps(handle, trans->remove, 1);
  /* free the old alltargs */
  alpm_list_free(trans->remove);
  trans->remove = lp;

  /* -Rcs == -Rc then -Rs */
  if((trans->flags & PM_TRANS_FLAG_CASCADE) && (trans->flags & PM_TRANS_FLAG_RECURSE)) {
    _alpm_log(handle, PM_LOG_DEBUG, "finding removable dependencies\n");
    _alpm_recursedeps(db, trans->remove, trans->flags & PM_TRANS_FLAG_RECURSEALL);
  }

  if(!(trans->flags & PM_TRANS_FLAG_NODEPS)) {
    EVENT(trans, PM_TRANS_EVT_CHECKDEPS_DONE, NULL, NULL);
  }

  return 0;
}

static int can_remove_file(alpm_handle_t *handle, const char *path,
    alpm_list_t *skip_remove)
{
  char file[PATH_MAX];

  snprintf(file, PATH_MAX, "%s%s", handle->root, path);

  if(alpm_list_find_str(skip_remove, file)) {
    /* return success because we will never actually remove this file */
    return 1;
  }
  /* If we fail write permissions due to a read-only filesystem, abort.
   * Assume all other possible failures are covered somewhere else */
  if(access(file, W_OK) == -1) {
    if(errno != EACCES && errno != ETXTBSY && access(file, F_OK) == 0) {
      /* only return failure if the file ACTUALLY exists and we can't write to
       * it - ignore "chmod -w" simple permission failures */
      _alpm_log(handle, PM_LOG_ERROR, _("cannot remove file '%s': %s\n"),
          file, strerror(errno));
      return 0;
    }
  }

  return 1;
}

/* Helper function for iterating through a package's file and deleting them
 * Used by _alpm_remove_commit. */
static void unlink_file(alpm_handle_t *handle, alpm_pkg_t *info, const char *filename,
    alpm_list_t *skip_remove, int nosave)
{
  struct stat buf;
  char file[PATH_MAX];

  snprintf(file, PATH_MAX, "%s%s", handle->root, filename);

  /* check the remove skip list before removing the file.
   * see the big comment block in db_find_fileconflicts() for an
   * explanation. */
  if(alpm_list_find_str(skip_remove, filename)) {
    _alpm_log(handle, PM_LOG_DEBUG, "%s is in skip_remove, skipping removal\n",
        file);
    return;
  }

  /* we want to do a lstat here, and not a _alpm_lstat.
   * if a directory in the package is actually a directory symlink on the
   * filesystem, we want to work with the linked directory instead of the
   * actual symlink */
  if(lstat(file, &buf)) {
    _alpm_log(handle, PM_LOG_DEBUG, "file %s does not exist\n", file);
    return;
  }

  if(S_ISDIR(buf.st_mode)) {
    if(rmdir(file)) {
      /* this is okay, other packages are probably using it (like /usr) */
      _alpm_log(handle, PM_LOG_DEBUG, "keeping directory %s\n", file);
    } else {
      _alpm_log(handle, PM_LOG_DEBUG, "removing directory %s\n", file);
    }
  } else {
    /* if the file needs backup and has been modified, back it up to .pacsave */
    pmbackup_t *backup = _alpm_needbackup(filename, alpm_pkg_get_backup(info));
    if(backup) {
      if(nosave) {
        _alpm_log(handle, PM_LOG_DEBUG, "transaction is set to NOSAVE, not backing up '%s'\n", file);
      } else {
        char *filehash = alpm_compute_md5sum(file);
        int cmp = filehash ? strcmp(filehash, backup->hash) : 0;
        FREE(filehash);
        if(cmp != 0) {
          char newpath[PATH_MAX];
          snprintf(newpath, PATH_MAX, "%s.pacsave", file);
          rename(file, newpath);
          _alpm_log(handle, PM_LOG_WARNING, _("%s saved as %s\n"), file, newpath);
          alpm_logaction(handle, "warning: %s saved as %s\n", file, newpath);
          return;
        }
      }
    }

    _alpm_log(handle, PM_LOG_DEBUG, "unlinking %s\n", file);

    if(unlink(file) == -1) {
      _alpm_log(handle, PM_LOG_ERROR, _("cannot remove file '%s': %s\n"),
          filename, strerror(errno));
    }
  }
}

int _alpm_upgraderemove_package(alpm_handle_t *handle,
    alpm_pkg_t *oldpkg, alpm_pkg_t *newpkg)
{
  alpm_list_t *skip_remove, *b;
  alpm_list_t *newfiles, *lp;
  size_t filenum = 0;
  alpm_list_t *files = alpm_pkg_get_files(oldpkg);
  const char *pkgname = alpm_pkg_get_name(oldpkg);

  _alpm_log(handle, PM_LOG_DEBUG, "removing old package first (%s-%s)\n",
      oldpkg->name, oldpkg->version);

  if(handle->trans->flags & PM_TRANS_FLAG_DBONLY) {
    goto db;
  }

  /* copy the remove skiplist over */
  skip_remove = alpm_list_join(
      alpm_list_strdup(handle->trans->skip_remove),
      alpm_list_strdup(handle->noupgrade));
  /* Add files in the NEW backup array to the skip_remove array
   * so this removal operation doesn't kill them */
  /* old package backup list */
  alpm_list_t *filelist = alpm_pkg_get_files(newpkg);
  for(b = alpm_pkg_get_backup(newpkg); b; b = b->next) {
    const pmbackup_t *backup = b->data;
    /* safety check (fix the upgrade026 pactest) */
    if(!alpm_list_find_str(filelist, backup->name)) {
      continue;
    }
    _alpm_log(handle, PM_LOG_DEBUG, "adding %s to the skip_remove array\n",
        backup->name);
    skip_remove = alpm_list_add(skip_remove, strdup(backup->name));
  }

  for(lp = files; lp; lp = lp->next) {
    if(!can_remove_file(handle, lp->data, skip_remove)) {
      _alpm_log(handle, PM_LOG_DEBUG,
          "not removing package '%s', can't remove all files\n", pkgname);
      RET_ERR(handle, PM_ERR_PKG_CANT_REMOVE, -1);
    }
    filenum++;
  }

  _alpm_log(handle, PM_LOG_DEBUG, "removing %ld files\n", (unsigned long)filenum);

  /* iterate through the list backwards, unlinking files */
  newfiles = alpm_list_reverse(files);
  for(lp = newfiles; lp; lp = alpm_list_next(lp)) {
    unlink_file(handle, oldpkg, lp->data, skip_remove, 0);
  }
  alpm_list_free(newfiles);
  FREELIST(skip_remove);

db:
  /* remove the package from the database */
  _alpm_log(handle, PM_LOG_DEBUG, "updating database\n");
  _alpm_log(handle, PM_LOG_DEBUG, "removing database entry '%s'\n", pkgname);
  if(_alpm_local_db_remove(handle->db_local, oldpkg) == -1) {
    _alpm_log(handle, PM_LOG_ERROR, _("could not remove database entry %s-%s\n"),
        pkgname, alpm_pkg_get_version(oldpkg));
  }
  /* remove the package from the cache */
  if(_alpm_db_remove_pkgfromcache(handle->db_local, oldpkg) == -1) {
    _alpm_log(handle, PM_LOG_ERROR, _("could not remove entry '%s' from cache\n"),
        pkgname);
  }

  return 0;
}

int _alpm_remove_packages(alpm_handle_t *handle)
{
  alpm_pkg_t *info;
  alpm_list_t *targ, *lp;
  size_t pkg_count;
  alpm_trans_t *trans = handle->trans;

  pkg_count = alpm_list_count(trans->remove);

  for(targ = trans->remove; targ; targ = targ->next) {
    int position = 0;
    char scriptlet[PATH_MAX];
    info = (alpm_pkg_t *)targ->data;
    const char *pkgname = NULL;
    size_t targcount = alpm_list_count(targ);

    if(trans->state == STATE_INTERRUPTED) {
      return 0;
    }

    /* get the name now so we can use it after package is removed */
    pkgname = alpm_pkg_get_name(info);
    snprintf(scriptlet, PATH_MAX, "%s%s-%s/install",
        _alpm_db_path(handle->db_local), pkgname, alpm_pkg_get_version(info));

    EVENT(trans, PM_TRANS_EVT_REMOVE_START, info, NULL);
    _alpm_log(handle, PM_LOG_DEBUG, "removing package %s-%s\n",
        pkgname, alpm_pkg_get_version(info));

    /* run the pre-remove scriptlet if it exists  */
    if(alpm_pkg_has_scriptlet(info) && !(trans->flags & PM_TRANS_FLAG_NOSCRIPTLET)) {
      _alpm_runscriptlet(handle, scriptlet, "pre_remove",
          alpm_pkg_get_version(info), NULL);
    }

    if(!(trans->flags & PM_TRANS_FLAG_DBONLY)) {
      alpm_list_t *files = alpm_pkg_get_files(info);
      alpm_list_t *newfiles;
      size_t filenum = 0;

      for(lp = files; lp; lp = lp->next) {
        if(!can_remove_file(handle, lp->data, NULL)) {
          _alpm_log(handle, PM_LOG_DEBUG, "not removing package '%s', can't remove all files\n",
                    pkgname);
          RET_ERR(handle, PM_ERR_PKG_CANT_REMOVE, -1);
        }
        filenum++;
      }

      _alpm_log(handle, PM_LOG_DEBUG, "removing %ld files\n", (unsigned long)filenum);

      /* init progress bar */
      PROGRESS(trans, PM_TRANS_PROGRESS_REMOVE_START, info->name, 0,
          pkg_count, (pkg_count - targcount + 1));

      /* iterate through the list backwards, unlinking files */
      newfiles = alpm_list_reverse(files);
      for(lp = newfiles; lp; lp = alpm_list_next(lp)) {
        int percent;
        unlink_file(handle, info, lp->data, NULL, trans->flags & PM_TRANS_FLAG_NOSAVE);

        /* update progress bar after each file */
        percent = (position * 100) / filenum;
        PROGRESS(trans, PM_TRANS_PROGRESS_REMOVE_START, info->name,
            percent, pkg_count, (pkg_count - targcount + 1));
        position++;
      }
      alpm_list_free(newfiles);
    }

    /* set progress to 100% after we finish unlinking files */
    PROGRESS(trans, PM_TRANS_PROGRESS_REMOVE_START, pkgname, 100,
             pkg_count, (pkg_count - targcount + 1));

    /* run the post-remove script if it exists  */
    if(alpm_pkg_has_scriptlet(info) && !(trans->flags & PM_TRANS_FLAG_NOSCRIPTLET)) {
      _alpm_runscriptlet(handle, scriptlet, "post_remove",
          alpm_pkg_get_version(info), NULL);
    }

    /* remove the package from the database */
    _alpm_log(handle, PM_LOG_DEBUG, "updating database\n");
    _alpm_log(handle, PM_LOG_DEBUG, "removing database entry '%s'\n", pkgname);
    if(_alpm_local_db_remove(handle->db_local, info) == -1) {
      _alpm_log(handle, PM_LOG_ERROR, _("could not remove database entry %s-%s\n"),
                pkgname, alpm_pkg_get_version(info));
    }
    /* remove the package from the cache */
    if(_alpm_db_remove_pkgfromcache(handle->db_local, info) == -1) {
      _alpm_log(handle, PM_LOG_ERROR, _("could not remove entry '%s' from cache\n"),
                pkgname);
    }

    EVENT(trans, PM_TRANS_EVT_REMOVE_DONE, info, NULL);
  }

  /* run ldconfig if it exists */
  _alpm_ldconfig(handle);

  return 0;
}

/* vim: set ts=2 sw=2 noet: */