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pacman/lib/libalpm/remove.c
Dan McGee aec60e3782 Fix segfault when uninstalling broken backed-up symlink
Issue FS#24230. If a symlink is broken and included in the removal
process of a package, we blew up and segfaulted due to
alpm_compute_md5sum() returning NULL and then performing a strcmp()
operation.

Signed-off-by: Dan McGee <dan@archlinux.org>
2011-05-16 11:50:13 -05:00

472 lines
14 KiB
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 <time.h>
#include <fcntl.h>
#include <string.h>
#include <limits.h>
#include <unistd.h>
#include <sys/stat.h>
/* libalpm */
#include "remove.h"
#include "alpm_list.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 "alpm.h"
int SYMEXPORT alpm_remove_pkg(pmpkg_t *pkg)
{
pmtrans_t *trans;
const char *pkgname;
ALPM_LOG_FUNC;
/* Sanity checks */
ASSERT(pkg != NULL, RET_ERR(PM_ERR_WRONG_ARGS, -1));
ASSERT(handle != NULL, RET_ERR(PM_ERR_HANDLE_NULL, -1));
trans = handle->trans;
ASSERT(trans != NULL, RET_ERR(PM_ERR_TRANS_NULL, -1));
ASSERT(trans->state == STATE_INITIALIZED,
RET_ERR(PM_ERR_TRANS_NOT_INITIALIZED, -1));
pkgname = alpm_pkg_get_name(pkg);
if(_alpm_pkg_find(trans->remove, pkgname)) {
RET_ERR(PM_ERR_TRANS_DUP_TARGET, -1);
}
_alpm_log(PM_LOG_DEBUG, "adding %s in the target list\n", pkgname);
trans->remove = alpm_list_add(trans->remove, _alpm_pkg_dup(pkg));
return(0);
}
static void remove_prepare_cascade(pmtrans_t *trans, pmdb_t *db,
alpm_list_t *lp)
{
ALPM_LOG_FUNC;
while(lp) {
alpm_list_t *i;
for(i = lp; i; i = i->next) {
pmdepmissing_t *miss = (pmdepmissing_t *)i->data;
pmpkg_t *info = _alpm_db_get_pkgfromcache(db, miss->target);
if(info) {
if(!_alpm_pkg_find(trans->remove, alpm_pkg_get_name(info))) {
_alpm_log(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(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(_alpm_db_get_pkgcache(db), 1, trans->remove, NULL);
}
}
static void remove_prepare_keep_needed(pmtrans_t *trans, pmdb_t *db,
alpm_list_t *lp)
{
ALPM_LOG_FUNC;
/* Remove needed packages (which break dependencies) from target list */
while(lp != NULL) {
alpm_list_t *i;
for(i = lp; i; i = i->next) {
pmdepmissing_t *miss = (pmdepmissing_t *)i->data;
void *vpkg;
pmpkg_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(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(_alpm_db_get_pkgcache(db), 1, trans->remove, NULL);
}
}
/** Transaction preparation for remove actions.
* This functions takes a pointer to a alpm_list_t which will be
* filled with a list of pmdepmissing_t* objects representing
* the packages blocking the transaction.
* @param trans the transaction object
* @param db the database of local packages
* @param data a pointer to an alpm_list_t* to fill
*/
int _alpm_remove_prepare(pmtrans_t *trans, pmdb_t *db, alpm_list_t **data)
{
alpm_list_t *lp;
ALPM_LOG_FUNC;
ASSERT(db != NULL, RET_ERR(PM_ERR_DB_NULL, -1));
ASSERT(trans != NULL, RET_ERR(PM_ERR_TRANS_NULL, -1));
if((trans->flags & PM_TRANS_FLAG_RECURSE) && !(trans->flags & PM_TRANS_FLAG_CASCADE)) {
_alpm_log(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(PM_LOG_DEBUG, "looking for unsatisfied dependencies\n");
lp = alpm_checkdeps(_alpm_db_get_pkgcache(db), 1, trans->remove, NULL);
if(lp != NULL) {
if(trans->flags & PM_TRANS_FLAG_CASCADE) {
remove_prepare_cascade(trans, db, lp);
} else if (trans->flags & PM_TRANS_FLAG_UNNEEDED) {
/* Remove needed packages (which would break dependencies)
* from target list */
remove_prepare_keep_needed(trans, db, 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(PM_ERR_UNSATISFIED_DEPS, -1);
}
}
}
/* re-order w.r.t. dependencies */
_alpm_log(PM_LOG_DEBUG, "sorting by dependencies\n");
lp = _alpm_sortbydeps(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(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(const char *path, alpm_list_t *skip)
{
char file[PATH_MAX+1];
snprintf(file, PATH_MAX, "%s%s", handle->root, path);
if(alpm_list_find_str(skip, 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(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(pmpkg_t *info, char *filename, alpm_list_t *skip_remove, int nosave)
{
struct stat buf;
char file[PATH_MAX+1];
ALPM_LOG_FUNC;
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(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(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(PM_LOG_DEBUG, "keeping directory %s\n", file);
} else {
_alpm_log(PM_LOG_DEBUG, "removing directory %s\n", file);
}
} else {
/* if the file needs backup and has been modified, back it up to .pacsave */
char *pkghash = _alpm_needbackup(filename, alpm_pkg_get_backup(info));
if(pkghash) {
if(nosave) {
_alpm_log(PM_LOG_DEBUG, "transaction is set to NOSAVE, not backing up '%s'\n", file);
FREE(pkghash);
} else {
char *filehash = alpm_compute_md5sum(file);
int cmp = filehash ? strcmp(filehash, pkghash) : 0;
FREE(filehash);
FREE(pkghash);
if(cmp != 0) {
char newpath[PATH_MAX];
snprintf(newpath, PATH_MAX, "%s.pacsave", file);
rename(file, newpath);
_alpm_log(PM_LOG_WARNING, _("%s saved as %s\n"), file, newpath);
alpm_logaction("warning: %s saved as %s\n", file, newpath);
return;
}
}
}
_alpm_log(PM_LOG_DEBUG, "unlinking %s\n", file);
if(unlink(file) == -1) {
_alpm_log(PM_LOG_ERROR, _("cannot remove file '%s': %s\n"),
filename, strerror(errno));
}
}
}
int _alpm_upgraderemove_package(pmpkg_t *oldpkg, pmpkg_t *newpkg,
pmtrans_t *trans)
{
alpm_list_t *skip_remove, *b;
alpm_list_t *newfiles, *lp;
size_t filenum;
alpm_list_t *files = alpm_pkg_get_files(oldpkg);
const char *pkgname = alpm_pkg_get_name(oldpkg);
ALPM_LOG_FUNC;
_alpm_log(PM_LOG_DEBUG, "removing old package first (%s-%s)\n",
oldpkg->name, oldpkg->version);
if(trans->flags & PM_TRANS_FLAG_DBONLY) {
goto db;
}
/* copy the remove skiplist over */
skip_remove = alpm_list_join(
alpm_list_strdup(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) {
char *backup = _alpm_backup_file(b->data);
/* safety check (fix the upgrade026 pactest) */
if(!alpm_list_find_str(filelist, backup)) {
FREE(backup);
continue;
}
_alpm_log(PM_LOG_DEBUG, "adding %s to the skip_remove array\n", backup);
skip_remove = alpm_list_add(skip_remove, backup);
}
for(lp = files; lp; lp = lp->next) {
if(!can_remove_file(lp->data, skip_remove)) {
_alpm_log(PM_LOG_DEBUG, "not removing package '%s', can't remove all files\n",
pkgname);
RET_ERR(PM_ERR_PKG_CANT_REMOVE, -1);
}
}
filenum = alpm_list_count(files);
_alpm_log(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(oldpkg, lp->data, skip_remove, 0);
}
alpm_list_free(newfiles);
FREELIST(skip_remove);
db:
/* remove the package from the database */
_alpm_log(PM_LOG_DEBUG, "updating database\n");
_alpm_log(PM_LOG_DEBUG, "removing database entry '%s'\n", pkgname);
if(_alpm_local_db_remove(handle->db_local, oldpkg) == -1) {
_alpm_log(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(PM_LOG_ERROR, _("could not remove entry '%s' from cache\n"),
pkgname);
}
return(0);
}
int _alpm_remove_packages(pmtrans_t *trans, pmdb_t *db)
{
pmpkg_t *info;
alpm_list_t *targ, *lp;
size_t pkg_count;
ALPM_LOG_FUNC;
ASSERT(db != NULL, RET_ERR(PM_ERR_DB_NULL, -1));
ASSERT(trans != NULL, RET_ERR(PM_ERR_TRANS_NULL, -1));
pkg_count = alpm_list_count(trans->remove);
for(targ = trans->remove; targ; targ = targ->next) {
int position = 0;
char scriptlet[PATH_MAX];
info = (pmpkg_t*)targ->data;
const char *pkgname = NULL;
size_t targcount = alpm_list_count(targ);
if(handle->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(db), pkgname, alpm_pkg_get_version(info));
EVENT(trans, PM_TRANS_EVT_REMOVE_START, info, NULL);
_alpm_log(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->root, scriptlet, "pre_remove",
alpm_pkg_get_version(info), NULL, trans);
}
if(!(trans->flags & PM_TRANS_FLAG_DBONLY)) {
alpm_list_t *files = alpm_pkg_get_files(info);
alpm_list_t *newfiles;
size_t filenum;
for(lp = files; lp; lp = lp->next) {
if(!can_remove_file(lp->data, NULL)) {
_alpm_log(PM_LOG_DEBUG, "not removing package '%s', can't remove all files\n",
pkgname);
RET_ERR(PM_ERR_PKG_CANT_REMOVE, -1);
}
}
filenum = alpm_list_count(files);
_alpm_log(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(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->root, scriptlet, "post_remove",
alpm_pkg_get_version(info), NULL, trans);
}
/* remove the package from the database */
_alpm_log(PM_LOG_DEBUG, "updating database\n");
_alpm_log(PM_LOG_DEBUG, "removing database entry '%s'\n", pkgname);
if(_alpm_local_db_remove(db, info) == -1) {
_alpm_log(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(db, info) == -1) {
_alpm_log(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->root);
return(0);
}
/* vim: set ts=2 sw=2 noet: */