remove.c

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/*
 *  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 <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"
#include "conflict.h"

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

    /* Sanity checks */
    CHECK_HANDLE(handle, return -1);
    ASSERT(pkg != NULL, RET_ERR(handle, ALPM_ERR_WRONG_ARGS, -1));
    ASSERT(handle == pkg->handle, RET_ERR(handle, ALPM_ERR_WRONG_ARGS, -1));
    trans = handle->trans;
    ASSERT(trans != NULL, RET_ERR(handle, ALPM_ERR_TRANS_NULL, -1));
    ASSERT(trans->state == STATE_INITIALIZED,
            RET_ERR(handle, ALPM_ERR_TRANS_NOT_INITIALIZED, -1));

    pkgname = pkg->name;

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

    _alpm_log(handle, ALPM_LOG_DEBUG, "adding package %s to the transaction remove list\n",
            pkgname);
    if(_alpm_pkg_dup(pkg, &copy) == -1) {
        return -1;
    }
    trans->remove = alpm_list_add(trans->remove, copy);
    return 0;
}

static int 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 = i->data;
            alpm_pkg_t *info = _alpm_db_get_pkgfromcache(handle->db_local, miss->target);
            if(info) {
                alpm_pkg_t *copy;
                if(!_alpm_pkg_find(trans->remove, info->name)) {
                    _alpm_log(handle, ALPM_LOG_DEBUG, "pulling %s in target list\n",
                            info->name);
                    if(_alpm_pkg_dup(info, &copy) == -1) {
                        return -1;
                    }
                    trans->remove = alpm_list_add(trans->remove, copy);
                }
            } else {
                _alpm_log(handle, ALPM_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);
    }
    return 0;
}

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 = 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, ALPM_LOG_WARNING, _("removing %s from target list\n"),
                        pkg->name);
                _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
 * @return 0 on success, -1 on error
 */
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 & ALPM_TRANS_FLAG_RECURSE)
            && !(trans->flags & ALPM_TRANS_FLAG_CASCADE)) {
        _alpm_log(handle, ALPM_LOG_DEBUG, "finding removable dependencies\n");
        if(_alpm_recursedeps(db, trans->remove,
                trans->flags & ALPM_TRANS_FLAG_RECURSEALL)) {
            return -1;
        }
    }

    if(!(trans->flags & ALPM_TRANS_FLAG_NODEPS)) {
        EVENT(handle, ALPM_EVENT_CHECKDEPS_START, NULL, NULL);

        _alpm_log(handle, ALPM_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 & ALPM_TRANS_FLAG_CASCADE) {
                if(remove_prepare_cascade(handle, lp)) {
                    return -1;
                }
            } else if(trans->flags & ALPM_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, ALPM_ERR_UNSATISFIED_DEPS, -1);
            }
        }
    }

    /* re-order w.r.t. dependencies */
    _alpm_log(handle, ALPM_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 & ALPM_TRANS_FLAG_CASCADE)
            && (trans->flags & ALPM_TRANS_FLAG_RECURSE)) {
        _alpm_log(handle, ALPM_LOG_DEBUG, "finding removable dependencies\n");
        if(_alpm_recursedeps(db, trans->remove,
                    trans->flags & ALPM_TRANS_FLAG_RECURSEALL)) {
            return -1;
        }
    }

    if(!(trans->flags & ALPM_TRANS_FLAG_NODEPS)) {
        EVENT(handle, ALPM_EVENT_CHECKDEPS_DONE, NULL, NULL);
    }

    return 0;
}

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

    if(alpm_list_find(skip_remove, file->name, _alpm_fnmatch)) {
        /* return success because we will never actually remove this file */
        return 1;
    }

    snprintf(filepath, PATH_MAX, "%s%s", handle->root, file->name);
    /* If we fail write permissions due to a read-only filesystem, abort.
     * Assume all other possible failures are covered somewhere else */
    if(_alpm_access(handle, NULL, filepath, W_OK) == -1) {
        if(errno != EACCES && errno != ETXTBSY && access(filepath, 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, ALPM_LOG_ERROR, _("cannot remove file '%s': %s\n"),
                    filepath, strerror(errno));
            return 0;
        }
    }

    return 1;
}

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

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

    /* 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(skip_remove, fileobj->name, _alpm_fnmatch)) {
        _alpm_log(handle, ALPM_LOG_DEBUG,
                "%s is in skip_remove, skipping removal\n", file);
        return 1;
    }

    /* 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, ALPM_LOG_DEBUG, "file %s does not exist\n", file);
        return 1;
    }

    if(S_ISDIR(buf.st_mode)) {
        ssize_t files = _alpm_files_in_directory(handle, file, 0);
        /* if we have files, no need to remove the directory */
        if(files > 0) {
            _alpm_log(handle, ALPM_LOG_DEBUG, "keeping directory %s (contains files)\n",
                    file);
        } else if(files < 0) {
            _alpm_log(handle, ALPM_LOG_DEBUG,
                    "keeping directory %s (could not count files)\n", file);
        } else if(newpkg && _alpm_filelist_contains(alpm_pkg_get_files(newpkg),
                    fileobj->name)) {
            _alpm_log(handle, ALPM_LOG_DEBUG,
                    "keeping directory %s (in new package)\n", file);
        } else {
            /* one last check- does any other package own this file? */
            alpm_list_t *local, *local_pkgs;
            int found = 0;
            local_pkgs = _alpm_db_get_pkgcache(handle->db_local);
            for(local = local_pkgs; local && !found; local = local->next) {
                alpm_pkg_t *local_pkg = local->data;
                alpm_filelist_t *filelist;

                /* we duplicated the package when we put it in the removal list, so we
                 * so we can't use direct pointer comparison here. */
                if(oldpkg->name_hash == local_pkg->name_hash
                        && strcmp(oldpkg->name, local_pkg->name) == 0) {
                    continue;
                }
                filelist = alpm_pkg_get_files(local_pkg);
                if(_alpm_filelist_contains(filelist, fileobj->name)) {
                    _alpm_log(handle, ALPM_LOG_DEBUG,
                            "keeping directory %s (owned by %s)\n", file, local_pkg->name);
                    found = 1;
                }
            }
            if(!found) {
                if(rmdir(file)) {
                    _alpm_log(handle, ALPM_LOG_DEBUG,
                            "directory removal of %s failed: %s\n", file, strerror(errno));
                    return -1;
                } else {
                    _alpm_log(handle, ALPM_LOG_DEBUG,
                            "removed directory %s (no remaining owners)\n", file);
                }
            }
        }
    } else {
        /* if the file needs backup and has been modified, back it up to .pacsave */
        alpm_backup_t *backup = _alpm_needbackup(fileobj->name, oldpkg);
        if(backup) {
            if(nosave) {
                _alpm_log(handle, ALPM_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;
                    size_t len = strlen(file) + 8 + 1;
                    MALLOC(newpath, len, RET_ERR(handle, ALPM_ERR_MEMORY, -1));
                    snprintf(newpath, len, "%s.pacsave", file);
                    if(rename(file, newpath)) {
                        _alpm_log(handle, ALPM_LOG_ERROR, _("could not rename %s to %s (%s)\n"),
                                file, newpath, strerror(errno));
                        alpm_logaction(handle, "error: could not rename %s to %s (%s)\n",
                                file, newpath, strerror(errno));
                        free(newpath);
                        return -1;
                    }
                    _alpm_log(handle, ALPM_LOG_WARNING, _("%s saved as %s\n"), file, newpath);
                    alpm_logaction(handle, "warning: %s saved as %s\n", file, newpath);
                    free(newpath);
                    return 0;
                }
            }
        }

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

        if(unlink(file) == -1) {
            _alpm_log(handle, ALPM_LOG_ERROR, _("cannot remove %s (%s)\n"),
                    file, strerror(errno));
            alpm_logaction(handle, "error: cannot remove %s (%s)\n",
                    file, strerror(errno));
            return -1;
        }
    }
    return 0;
}

static int remove_package_files(alpm_handle_t *handle,
        alpm_pkg_t *oldpkg, alpm_pkg_t *newpkg,
        size_t targ_count, size_t pkg_count)
{
    alpm_list_t *skip_remove;
    alpm_filelist_t *filelist;
    size_t i;
    int err = 0;
    int nosave = handle->trans->flags & ALPM_TRANS_FLAG_NOSAVE;

    if(newpkg) {
        alpm_filelist_t *newfiles;
        alpm_list_t *b;
        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 */
        newfiles = alpm_pkg_get_files(newpkg);
        for(b = alpm_pkg_get_backup(newpkg); b; b = b->next) {
            const alpm_backup_t *backup = b->data;
            /* safety check (fix the upgrade026 pactest) */
            if(!_alpm_filelist_contains(newfiles, backup->name)) {
                continue;
            }
            _alpm_log(handle, ALPM_LOG_DEBUG, "adding %s to the skip_remove array\n",
                    backup->name);
            skip_remove = alpm_list_add(skip_remove, strdup(backup->name));
        }
    } else {
        skip_remove = alpm_list_strdup(handle->trans->skip_remove);
    }

    filelist = alpm_pkg_get_files(oldpkg);
    for(i = 0; i < filelist->count; i++) {
        alpm_file_t *file = filelist->files + i;
        if(!can_remove_file(handle, file, skip_remove)) {
            _alpm_log(handle, ALPM_LOG_DEBUG,
                    "not removing package '%s', can't remove all files\n",
                    oldpkg->name);
            FREELIST(skip_remove);
            RET_ERR(handle, ALPM_ERR_PKG_CANT_REMOVE, -1);
        }
    }

    _alpm_log(handle, ALPM_LOG_DEBUG, "removing %zd files\n", filelist->count);

    if(!newpkg) {
        /* init progress bar, but only on true remove transactions */
        PROGRESS(handle, ALPM_PROGRESS_REMOVE_START, oldpkg->name, 0,
                pkg_count, targ_count);
    }

    /* iterate through the list backwards, unlinking files */
    for(i = filelist->count; i > 0; i--) {
        alpm_file_t *file = filelist->files + i - 1;
        if(unlink_file(handle, oldpkg, newpkg, file, skip_remove, nosave) < 0) {
            err++;
        }

        if(!newpkg) {
            /* update progress bar after each file */
            int percent = ((filelist->count - i) * 100) / filelist->count;
            PROGRESS(handle, ALPM_PROGRESS_REMOVE_START, oldpkg->name,
                    percent, pkg_count, targ_count);
        }
    }
    FREELIST(skip_remove);

    if(!newpkg) {
        /* set progress to 100% after we finish unlinking files */
        PROGRESS(handle, ALPM_PROGRESS_REMOVE_START, oldpkg->name, 100,
                pkg_count, targ_count);
    }

    return err;
}

int _alpm_remove_single_package(alpm_handle_t *handle,
        alpm_pkg_t *oldpkg, alpm_pkg_t *newpkg,
        size_t targ_count, size_t pkg_count)
{
    const char *pkgname = oldpkg->name;
    const char *pkgver = oldpkg->version;

    if(newpkg) {
        _alpm_log(handle, ALPM_LOG_DEBUG, "removing old package first (%s-%s)\n",
                pkgname, pkgver);
    } else {
        EVENT(handle, ALPM_EVENT_REMOVE_START, oldpkg, NULL);
        _alpm_log(handle, ALPM_LOG_DEBUG, "removing package %s-%s\n",
                pkgname, pkgver);

        /* run the pre-remove scriptlet if it exists  */
        if(alpm_pkg_has_scriptlet(oldpkg) &&
                !(handle->trans->flags & ALPM_TRANS_FLAG_NOSCRIPTLET)) {
            char *scriptlet = _alpm_local_db_pkgpath(handle->db_local,
                    oldpkg, "install");
            _alpm_runscriptlet(handle, scriptlet, "pre_remove", pkgver, NULL, 0);
            free(scriptlet);
        }
    }

    if(!(handle->trans->flags & ALPM_TRANS_FLAG_DBONLY)) {
        /* TODO check returned errors if any */
        remove_package_files(handle, oldpkg, newpkg, targ_count, pkg_count);
    }

    /* run the post-remove script if it exists  */
    if(!newpkg && alpm_pkg_has_scriptlet(oldpkg) &&
            !(handle->trans->flags & ALPM_TRANS_FLAG_NOSCRIPTLET)) {
        char *scriptlet = _alpm_local_db_pkgpath(handle->db_local,
                oldpkg, "install");
        _alpm_runscriptlet(handle, scriptlet, "post_remove", pkgver, NULL, 0);
        free(scriptlet);
    }

    if(!newpkg) {
        EVENT(handle, ALPM_EVENT_REMOVE_DONE, oldpkg, NULL);
    }

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

    return 0;
}

int _alpm_remove_packages(alpm_handle_t *handle, int run_ldconfig)
{
    alpm_list_t *targ;
    size_t pkg_count, targ_count;
    alpm_trans_t *trans = handle->trans;
    int ret = 0;

    pkg_count = alpm_list_count(trans->remove);
    targ_count = 1;

    for(targ = trans->remove; targ; targ = targ->next) {
        alpm_pkg_t *pkg = targ->data;

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

        if(_alpm_remove_single_package(handle, pkg, NULL,
                    targ_count, pkg_count) == -1) {
            handle->pm_errno = ALPM_ERR_TRANS_ABORT;
            /* running ldconfig at this point could possibly screw system */
            run_ldconfig = 0;
            ret = -1;
        }

        targ_count++;
    }

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

    return ret;
}

/* vim: set ts=2 sw=2 noet: */