path: root/lib/libalpm/conflict.c

/*
 *  conflict.c
 *
 *  Copyright (c) 2006-2014 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) 2006 by David Kimpe <dnaku@frugalware.org>
 *  Copyright (c) 2006 by Miklos Vajna <vmiklos@frugalware.org>
 *  Copyright (c) 2006 by Christian Hamar <krics@linuxforum.hu>
 *
 *  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 <stdio.h>
#include <string.h>
#include <limits.h>
#include <sys/stat.h>
#include <dirent.h>

/* libalpm */
#include "conflict.h"
#include "alpm_list.h"
#include "alpm.h"
#include "handle.h"
#include "trans.h"
#include "util.h"
#include "log.h"
#include "deps.h"
#include "filelist.h"

/**
 * @brief Creates a new conflict.
 */
static alpm_conflict_t *conflict_new(alpm_pkg_t *pkg1, alpm_pkg_t *pkg2,
                alpm_depend_t *reason)
{
        alpm_conflict_t *conflict;

        MALLOC(conflict, sizeof(alpm_conflict_t), return NULL);

        conflict->package1_hash = pkg1->name_hash;
        conflict->package2_hash = pkg2->name_hash;
        STRDUP(conflict->package1, pkg1->name, goto error);
        STRDUP(conflict->package2, pkg2->name, goto error);
        conflict->reason = reason;

        return conflict;

error:
        alpm_conflict_free(conflict);
        return NULL;
}

/**
 * @brief Free a conflict and its members.
 */
void SYMEXPORT alpm_conflict_free(alpm_conflict_t *conflict)
{
        FREE(conflict->package2);
        FREE(conflict->package1);
        FREE(conflict);
}

/**
 * @brief Creates a copy of a conflict.
 */
alpm_conflict_t *_alpm_conflict_dup(const alpm_conflict_t *conflict)
{
        alpm_conflict_t *newconflict;
        CALLOC(newconflict, 1, sizeof(alpm_conflict_t), return NULL);

        newconflict->package1_hash = conflict->package1_hash;
        newconflict->package2_hash = conflict->package2_hash;
        STRDUP(newconflict->package1, conflict->package1, goto error);
        STRDUP(newconflict->package2, conflict->package2, goto error);
        newconflict->reason = conflict->reason;

        return newconflict;

error:
        alpm_conflict_free(newconflict);
        return NULL;
}

/**
 * @brief Searches for a conflict in a list.
 *
 * @param needle conflict to search for
 * @param haystack list of conflicts to search
 *
 * @return 1 if needle is in haystack, 0 otherwise
 */
static int conflict_isin(alpm_conflict_t *needle, alpm_list_t *haystack)
{
        alpm_list_t *i;
        for(i = haystack; i; i = i->next) {
                alpm_conflict_t *conflict = i->data;
                if(needle->package1_hash == conflict->package1_hash
                                && needle->package2_hash == conflict->package2_hash
                                && strcmp(needle->package1, conflict->package1) == 0
                                && strcmp(needle->package2, conflict->package2) == 0) {
                        return 1;
                }
        }

        return 0;
}

/**
 * @brief Adds the pkg1/pkg2 conflict to the baddeps list.
 *
 * @param handle the context handle
 * @param baddeps list to add conflict to
 * @param pkg1 first package
 * @param pkg2 package causing conflict
 * @param reason reason for this conflict
 *
 * @return 0 on success, -1 on error
 */
static int add_conflict(alpm_handle_t *handle, alpm_list_t **baddeps,
                alpm_pkg_t *pkg1, alpm_pkg_t *pkg2, alpm_depend_t *reason)
{
        alpm_conflict_t *conflict = conflict_new(pkg1, pkg2, reason);
        if(!conflict) {
                return -1;
        }
        if(!conflict_isin(conflict, *baddeps)) {
                char *conflict_str = alpm_dep_compute_string(reason);
                *baddeps = alpm_list_add(*baddeps, conflict);
                _alpm_log(handle, ALPM_LOG_DEBUG, "package %s conflicts with %s (by %s)\n",
                                pkg1->name, pkg2->name, conflict_str);
                free(conflict_str);
        } else {
                alpm_conflict_free(conflict);
        }
        return 0;
}

/**
 * @brief Check if packages from list1 conflict with packages from list2.
 *
 * @details This looks at the conflicts fields of all packages from list1, and
 * sees if they match packages from list2. If a conflict (pkg1, pkg2) is found,
 * it is added to the baddeps list in this order if order >= 0, or reverse
 * order (pkg2,pkg1) otherwise.
 *
 * @param handle the context handle
 * @param list1 first list of packages
 * @param list2 second list of packages
 * @param baddeps list to store conflicts
 * @param order if >= 0 the conflict order is preserved, if < 0 it's reversed
 */
static void check_conflict(alpm_handle_t *handle,
                alpm_list_t *list1, alpm_list_t *list2,
                alpm_list_t **baddeps, int order)
{
        alpm_list_t *i;

        if(!baddeps) {
                return;
        }
        for(i = list1; i; i = i->next) {
                alpm_pkg_t *pkg1 = i->data;
                alpm_list_t *j;

                for(j = alpm_pkg_get_conflicts(pkg1); j; j = j->next) {
                        alpm_depend_t *conflict = j->data;
                        alpm_list_t *k;

                        for(k = list2; k; k = k->next) {
                                alpm_pkg_t *pkg2 = k->data;

                                if(pkg1->name_hash == pkg2->name_hash
                                                && strcmp(pkg1->name, pkg2->name) == 0) {
                                        /* skip the package we're currently processing */
                                        continue;
                                }

                                if(_alpm_depcmp(pkg2, conflict)) {
                                        if(order >= 0) {
                                                add_conflict(handle, baddeps, pkg1, pkg2, conflict);
                                        } else {
                                                add_conflict(handle, baddeps, pkg2, pkg1, conflict);
                                        }
                                }
                        }
                }
        }
}

/**
 * @brief Check for inter-conflicts in a list of packages.
 *
 * @param handle the context handle
 * @param packages list of packages to check
 *
 * @return list of conflicts
 */
alpm_list_t *_alpm_innerconflicts(alpm_handle_t *handle, alpm_list_t *packages)
{
        alpm_list_t *baddeps = NULL;

        _alpm_log(handle, ALPM_LOG_DEBUG, "check targets vs targets\n");
        check_conflict(handle, packages, packages, &baddeps, 0);

        return baddeps;
}

/**
 * @brief Returns a list of conflicts between a db and a list of packages.
 */
alpm_list_t *_alpm_outerconflicts(alpm_db_t *db, alpm_list_t *packages)
{
        alpm_list_t *baddeps = NULL;

        if(db == NULL) {
                return NULL;
        }

        alpm_list_t *dblist = alpm_list_diff(_alpm_db_get_pkgcache(db),
                        packages, _alpm_pkg_cmp);

        /* two checks to be done here for conflicts */
        _alpm_log(db->handle, ALPM_LOG_DEBUG, "check targets vs db\n");
        check_conflict(db->handle, packages, dblist, &baddeps, 1);
        _alpm_log(db->handle, ALPM_LOG_DEBUG, "check db vs targets\n");
        check_conflict(db->handle, dblist, packages, &baddeps, -1);

        alpm_list_free(dblist);
        return baddeps;
}

/**
 * @brief Check the package conflicts in a database
 *
 * @param handle the context handle
 * @param pkglist the list of packages to check
 *
 * @return an alpm_list_t of alpm_conflict_t
 */
alpm_list_t SYMEXPORT *alpm_checkconflicts(alpm_handle_t *handle,
                alpm_list_t *pkglist)
{
        CHECK_HANDLE(handle, return NULL);
        return _alpm_innerconflicts(handle, pkglist);
}

/**
 * @brief Creates and adds a file conflict to a conflict list.
 *
 * @param handle the context handle
 * @param conflicts the list of conflicts to append to
 * @param filestr the conflicting file path
 * @param pkg1 package that wishes to install the file
 * @param pkg2 package that currently owns the file, or NULL if unowned
 *
 * @return the updated conflict list
 */
static alpm_list_t *add_fileconflict(alpm_handle_t *handle,
                alpm_list_t *conflicts, const char *filestr,
                alpm_pkg_t *pkg1, alpm_pkg_t *pkg2)
{
        alpm_fileconflict_t *conflict;
        MALLOC(conflict, sizeof(alpm_fileconflict_t), goto error);

        STRDUP(conflict->target, pkg1->name, goto error);
        STRDUP(conflict->file, filestr, goto error);
        if(pkg2) {
                conflict->type = ALPM_FILECONFLICT_TARGET;
                STRDUP(conflict->ctarget, pkg2->name, goto error);
        } else {
                conflict->type = ALPM_FILECONFLICT_FILESYSTEM;
                STRDUP(conflict->ctarget, "", goto error);
        }

        conflicts = alpm_list_add(conflicts, conflict);
        _alpm_log(handle, ALPM_LOG_DEBUG, "found file conflict %s, packages %s and %s\n",
                  filestr, pkg1->name, pkg2 ? pkg2->name : "(filesystem)");

        return conflicts;

error:
        alpm_fileconflict_free(conflict);
        RET_ERR(handle, ALPM_ERR_MEMORY, conflicts);
}

/**
 * @brief Frees a conflict and its members.
 */
void SYMEXPORT alpm_fileconflict_free(alpm_fileconflict_t *conflict)
{
        FREE(conflict->ctarget);
        FREE(conflict->file);
        FREE(conflict->target);
        FREE(conflict);
}

/**
 * @brief Recursively checks if a set of packages own all subdirectories and
 * files in a directory.
 *
 * @param handle the context handle
 * @param dirpath path of the directory to check
 * @param pkgs packages being checked against
 *
 * @return 1 if a package owns all subdirectories and files, 0 otherwise
 */
static int dir_belongsto_pkgs(alpm_handle_t *handle, const char *dirpath,
                alpm_list_t *pkgs)
{
        char path[PATH_MAX], full_path[PATH_MAX];
        DIR *dir;
        struct dirent *ent = NULL;

        snprintf(full_path, PATH_MAX, "%s%s", handle->root, dirpath);
        dir = opendir(full_path);
        if(dir == NULL) {
                return 0;
        }

        while((ent = readdir(dir)) != NULL) {
                const char *name = ent->d_name;
                int owned = 0, is_dir = 0;
                alpm_list_t *i;
                struct stat sbuf;

                if(strcmp(name, ".") == 0 || strcmp(name, "..") == 0) {
                        continue;
                }

                snprintf(full_path, PATH_MAX, "%s%s%s", handle->root, dirpath, name);

                if(lstat(full_path, &sbuf) != 0) {
                        _alpm_log(handle, ALPM_LOG_DEBUG, "could not stat %s\n", full_path);
                        closedir(dir);
                        return 0;
                }
                is_dir = S_ISDIR(sbuf.st_mode);

                snprintf(path, PATH_MAX, "%s%s%s", dirpath, name, is_dir ? "/" : "");

                for(i = pkgs; i && !owned; i = i->next) {
                        if(alpm_filelist_contains(alpm_pkg_get_files(i->data), path)) {
                                owned = 1;
                        }
                }

                if(owned && is_dir) {
                        owned = dir_belongsto_pkgs(handle, path, pkgs);
                }

                if(!owned) {
                        closedir(dir);
                        _alpm_log(handle, ALPM_LOG_DEBUG,
                                        "unowned file %s found in directory\n", path);
                        return 0;
                }
        }
        closedir(dir);
        return 1;
}

static alpm_list_t *alpm_db_find_file_owners(alpm_db_t* db, const char *path)
{
        alpm_list_t *i, *owners = NULL;
        for(i = alpm_db_get_pkgcache(db); i; i = i->next) {
                if(alpm_filelist_contains(alpm_pkg_get_files(i->data), path)) {
                        owners = alpm_list_add(owners, i->data);
                }
        }
        return owners;
}

/**
 * @brief Find file conflicts that may occur during the transaction.
 *
 * @details Performs two checks:
 *   1. check every target against every target
 *   2. check every target against the filesystem
 *
 * @param handle the context handle
 * @param upgrade list of packages being installed
 * @param rem list of packages being removed
 *
 * @return list of file conflicts
 */
alpm_list_t *_alpm_db_find_fileconflicts(alpm_handle_t *handle,
                alpm_list_t *upgrade, alpm_list_t *rem)
{
        alpm_list_t *i, *conflicts = NULL;
        size_t numtargs = alpm_list_count(upgrade);
        size_t current;
        size_t rootlen;

        if(!upgrade) {
                return NULL;
        }

        rootlen = strlen(handle->root);

        /* TODO this whole function needs a huge change, which hopefully will
         * be possible with real transactions. Right now we only do half as much
         * here as we do when we actually extract files in add.c with our 12
         * different cases. */
        for(current = 0, i = upgrade; i; i = i->next, current++) {
                alpm_pkg_t *p1 = i->data;
                alpm_list_t *j;
                alpm_list_t *tmpfiles = NULL;
                alpm_pkg_t *dbpkg;

                int percent = (current * 100) / numtargs;
                PROGRESS(handle, ALPM_PROGRESS_CONFLICTS_START, "", percent,
                         numtargs, current);

                /* CHECK 1: check every target against every target */
                _alpm_log(handle, ALPM_LOG_DEBUG, "searching for file conflicts: %s\n",
                                p1->name);
                for(j = i->next; j; j = j->next) {
                        alpm_list_t *common_files;
                        alpm_pkg_t *p2 = j->data;

                        alpm_filelist_t *p1_files = alpm_pkg_get_files(p1);
                        alpm_filelist_t *p2_files = alpm_pkg_get_files(p2);

                        common_files = _alpm_filelist_intersection(p1_files, p2_files);

                        if(common_files) {
                                alpm_list_t *k;
                                char path[PATH_MAX];
                                for(k = common_files; k; k = k->next) {
                                        char *filename = k->data;
                                        snprintf(path, PATH_MAX, "%s%s", handle->root, filename);

                                        /* can skip file-file conflicts when forced *
                                         * checking presence in p2_files detects dir-file or file-dir
                                         * conflicts as the path from p1 is returned */
                                        if((handle->trans->flags & ALPM_TRANS_FLAG_FORCE) &&
                                                        alpm_filelist_contains(p2_files, filename)) {
                                                _alpm_log(handle, ALPM_LOG_DEBUG,
                                                        "%s exists in both '%s' and '%s'\n", filename,
                                                        p1->name, p2->name);
                                                _alpm_log(handle, ALPM_LOG_DEBUG,
                                                        "file-file conflict being forced\n");
                                                continue;
                                        }

                                        conflicts = add_fileconflict(handle, conflicts, path, p1, p2);
                                        if(handle->pm_errno == ALPM_ERR_MEMORY) {
                                                alpm_list_free_inner(conflicts,
                                                                (alpm_list_fn_free) alpm_conflict_free);
                                                alpm_list_free(conflicts);
                                                alpm_list_free(common_files);
                                                return NULL;
                                        }
                                }
                                alpm_list_free(common_files);
                        }
                }

                /* CHECK 2: check every target against the filesystem */
                _alpm_log(handle, ALPM_LOG_DEBUG, "searching for filesystem conflicts: %s\n",
                                p1->name);
                dbpkg = _alpm_db_get_pkgfromcache(handle->db_local, p1->name);

                /* Do two different checks here. If the package is currently installed,
                 * then only check files that are new in the new package. If the package
                 * is not currently installed, then simply stat the whole filelist. Note
                 * that the former list needs to be freed while the latter list should NOT
                 * be freed. */
                if(dbpkg) {
                        /* older ver of package currently installed */
                        tmpfiles = _alpm_filelist_difference(alpm_pkg_get_files(p1),
                                        alpm_pkg_get_files(dbpkg));
                } else {
                        /* no version of package currently installed */
                        alpm_filelist_t *fl = alpm_pkg_get_files(p1);
                        size_t filenum;
                        for(filenum = 0; filenum < fl->count; filenum++) {
                                tmpfiles = alpm_list_add(tmpfiles, fl->files[filenum].name);
                        }
                }

                for(j = tmpfiles; j; j = j->next) {
                        const char *filestr = j->data;
                        const char *relative_path;
                        alpm_list_t *k;
                        /* have we acted on this conflict? */
                        int resolved_conflict = 0;
                        struct stat lsbuf;
                        char path[PATH_MAX];
                        size_t pathlen;

                        pathlen = snprintf(path, PATH_MAX, "%s%s", handle->root, filestr);
                        relative_path = path + rootlen;

                        /* stat the file - if it exists, do some checks */
                        if(llstat(path, &lsbuf) != 0) {
                                continue;
                        }

                        _alpm_log(handle, ALPM_LOG_DEBUG, "checking possible conflict: %s\n", path);

                        if(path[pathlen - 1] == '/') {
                                if(S_ISDIR(lsbuf.st_mode)) {
                                        _alpm_log(handle, ALPM_LOG_DEBUG, "file is a directory, not a conflict\n");
                                        continue;
                                }
                                /* if we made it to here, we want all subsequent path comparisons to
                                 * not include the trailing slash. This allows things like file ->
                                 * directory replacements. */
                                path[pathlen - 1] = '\0';

                                /* Check if the directory was a file in dbpkg */
                                if(alpm_filelist_contains(alpm_pkg_get_files(dbpkg), relative_path)) {
                                        size_t fslen = strlen(filestr);
                                        _alpm_log(handle, ALPM_LOG_DEBUG,
                                                        "replacing package file with a directory, not a conflict\n");
                                        resolved_conflict = 1;

                                        /* go ahead and skip any files inside filestr as they will
                                         * necessarily be resolved by replacing the file with a dir
                                         * NOTE: afterward, j will point to the last file inside filestr */
                                        for( ; j->next; j = j->next) {
                                                const char *filestr2 = j->next->data;
                                                if(strncmp(filestr, filestr2, fslen) != 0) {
                                                        break;
                                                }
                                        }
                                }
                        }

                        /* Check remove list (will we remove the conflicting local file?) */
                        for(k = rem; k && !resolved_conflict; k = k->next) {
                                alpm_pkg_t *rempkg = k->data;
                                if(rempkg && alpm_filelist_contains(alpm_pkg_get_files(rempkg),
                                                        relative_path)) {
                                        _alpm_log(handle, ALPM_LOG_DEBUG,
                                                        "local file will be removed, not a conflict\n");
                                        resolved_conflict = 1;
                                }
                        }

                        /* Look at all the targets to see if file has changed hands */
                        for(k = upgrade; k && !resolved_conflict; k = k->next) {
                                alpm_pkg_t *localp2, *p2 = k->data;
                                if(!p2 || p1 == p2) {
                                        /* skip p1; both p1 and p2 come directly from the upgrade list
                                         * so they can be compared directly */
                                        continue;
                                }
                                localp2 = _alpm_db_get_pkgfromcache(handle->db_local, p2->name);

                                /* localp2->files will be removed (target conflicts are handled by CHECK 1) */
                                if(localp2 && alpm_filelist_contains(alpm_pkg_get_files(localp2), relative_path)) {
                                        /* skip removal of file, but not add. this will prevent a second
                                         * package from removing the file when it was already installed
                                         * by its new owner (whether the file is in backup array or not */
                                        handle->trans->skip_remove =
                                                alpm_list_add(handle->trans->skip_remove, strdup(relative_path));
                                        _alpm_log(handle, ALPM_LOG_DEBUG,
                                                        "file changed packages, adding to remove skiplist\n");
                                        resolved_conflict = 1;
                                }
                        }

                        /* check if all files of the dir belong to the installed pkg */
                        if(!resolved_conflict && S_ISDIR(lsbuf.st_mode)) {
                                alpm_list_t *owners;
                                char *dir = malloc(strlen(relative_path) + 2);
                                sprintf(dir, "%s/", relative_path);

                                owners = alpm_db_find_file_owners(handle->db_local, dir);
                                if(owners) {
                                        alpm_list_t *pkgs = NULL, *diff;

                                        if(dbpkg) {
                                                pkgs = alpm_list_add(pkgs, dbpkg);
                                        }
                                        pkgs = alpm_list_join(pkgs, alpm_list_copy(rem));
                                        if((diff = alpm_list_diff(owners, pkgs, _alpm_pkg_cmp))) {
                                                /* dir is owned by files we aren't removing */
                                                /* TODO: with better commit ordering, we may be able to check
                                                 * against upgrades as well */
                                                alpm_list_free(diff);
                                        } else {
                                                _alpm_log(handle, ALPM_LOG_DEBUG,
                                                                "checking if all files in %s belong to removed packages\n",
                                                                dir);
                                                resolved_conflict = dir_belongsto_pkgs(handle, dir, owners);
                                        }
                                        alpm_list_free(pkgs);
                                        alpm_list_free(owners);
                                }
                                free(dir);
                        }

                        /* is the file unowned and in the backup list of the new package? */
                        if(!resolved_conflict && _alpm_needbackup(relative_path, p1)) {
                                alpm_list_t *local_pkgs = _alpm_db_get_pkgcache(handle->db_local);
                                int found = 0;
                                for(k = local_pkgs; k && !found; k = k->next) {
                                        if(alpm_filelist_contains(alpm_pkg_get_files(k->data), relative_path)) {
                                                        found = 1;
                                        }
                                }
                                if(!found) {
                                        _alpm_log(handle, ALPM_LOG_DEBUG,
                                                        "file was unowned but in new backup list\n");
                                        resolved_conflict = 1;
                                }
                        }

                        /* skip file-file conflicts when being forced */
                        if((handle->trans->flags & ALPM_TRANS_FLAG_FORCE) &&
                                        !S_ISDIR(lsbuf.st_mode)) {
                                _alpm_log(handle, ALPM_LOG_DEBUG,
                                                        "conflict with file on filesystem being forced\n");
                                resolved_conflict = 1;
                        }

                        if(!resolved_conflict) {
                                conflicts = add_fileconflict(handle, conflicts, path, p1, NULL);
                                if(handle->pm_errno == ALPM_ERR_MEMORY) {
                                        alpm_list_free_inner(conflicts,
                                                        (alpm_list_fn_free) alpm_conflict_free);
                                        alpm_list_free(conflicts);
                                        alpm_list_free(tmpfiles);
                                        return NULL;
                                }
                        }
                }
                alpm_list_free(tmpfiles);
        }
        PROGRESS(handle, ALPM_PROGRESS_CONFLICTS_START, "", 100,
                        numtargs, current);

        return conflicts;
}

/* vim: set noet: */