path: root/lib/libalpm/conflict.c

/*
 *  conflict.c
 * 
 *  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, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 
 *  USA.
 */

#include "config.h"

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

/* libalpm */
#include "conflict.h"
#include "alpm_list.h"
#include "handle.h"
#include "trans.h"
#include "util.h"
#include "error.h"
#include "log.h"
#include "cache.h"
#include "deps.h"


/** Check if pkg1 conflicts with pkg2
 * @param pkg1 package we are looking at
 * @param conflict name of the possible conflict
 * @param pkg2 package to check
 * @return 0 for no conflict, non-zero otherwise
 */
static int does_conflict(pmpkg_t *pkg1, const char *conflict, pmpkg_t *pkg2)
{
  const char *pkg1name = alpm_pkg_get_name(pkg1);
  const char *pkg2name = alpm_pkg_get_name(pkg2);
  pmdepend_t *conf = alpm_splitdep(conflict);
  int match = 0;

  match = alpm_depcmp(pkg2, conf);
  if(match) {
    _alpm_log(PM_LOG_DEBUG, "package %s conflicts with %s (by %s)\n",
        pkg1name, pkg2name, conflict);
  }
  FREE(conf);
  return(match);
}

/** Adds the pkg1/pkg2 conflict to the baddeps list
 * @param *baddeps list to add conflict to
 * @param pkg1 first package
 * @param pkg2 package causing conflict
 */
/* TODO WTF is a 'depmissing' doing indicating a conflict? */
static void add_conflict(alpm_list_t **baddeps, const char *pkg1,
    const char *pkg2)
{
  pmdepmissing_t *miss = _alpm_depmiss_new(pkg1, PM_DEP_TYPE_CONFLICT,
      PM_DEP_MOD_ANY, pkg2, NULL);
  if(miss && !_alpm_depmiss_isin(miss, *baddeps)) {
    *baddeps = alpm_list_add(*baddeps, miss);
  } else {
    FREE(miss);
  }
}

/** Check if packages from list1 conflict with packages from list2.
 * 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 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_list_t *list1, alpm_list_t *list2,
    alpm_list_t **baddeps, int order) {
  alpm_list_t *i, *j, *k;

  if(!baddeps) {
    return;
  }
  for(i = list1; i; i = i->next) {
    pmpkg_t *pkg1 = i->data;
    const char *pkg1name = alpm_pkg_get_name(pkg1);

    for(j = alpm_pkg_get_conflicts(pkg1); j; j = j->next) {
      const char *conflict = j->data;

      for(k = list2; k; k = k->next) {
        pmpkg_t *pkg2 = k->data;
        const char *pkg2name = alpm_pkg_get_name(pkg2);

        if(strcmp(pkg1name, pkg2name) == 0) {
          /* skip the package we're currently processing */
          continue;
        }

        if(does_conflict(pkg1, conflict, pkg2)) {
          if(order >= 0) {
            add_conflict(baddeps, pkg1name, pkg2name);
          } else {
            add_conflict(baddeps, pkg2name, pkg1name);
          }
        }
      }
    }
  }
}

/* Returns a alpm_list_t* of pmdepmissing_t pointers. */
alpm_list_t *_alpm_checkconflicts(pmdb_t *db, alpm_list_t *packages)
{
  alpm_list_t *baddeps = NULL;

  ALPM_LOG_FUNC;

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

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

  /* three checks to be done here for conflicts */
  _alpm_log(PM_LOG_DEBUG, "check targets vs db\n");
  check_conflict(packages, dblist, &baddeps, 1);
  _alpm_log(PM_LOG_DEBUG, "check db vs targets\n");
  check_conflict(dblist, packages, &baddeps, -1);
  _alpm_log(PM_LOG_DEBUG, "check targets vs targets\n");
  check_conflict(packages, packages, &baddeps, 0);

  alpm_list_free(dblist);
  return(baddeps);
}

/* Returns a alpm_list_t* of file conflicts.
 *  Hooray for set-intersects!
 *  Pre-condition: both lists are sorted!
 */
static alpm_list_t *chk_fileconflicts(alpm_list_t *filesA, alpm_list_t *filesB)
{
  alpm_list_t *ret = NULL;
  alpm_list_t *pA = filesA, *pB = filesB;

  while(pA && pB) {
    const char *strA = pA->data;
    const char *strB = pB->data;
    /* skip directories, we don't care about dir conflicts */
    if(strA[strlen(strA)-1] == '/') {
      pA = pA->next;
    } else if(strB[strlen(strB)-1] == '/') {
      pB = pB->next;
    } else {
      int cmp = strcmp(strA, strB);
      if(cmp < 0) {
        /* item only in filesA, ignore it */
        pA = pA->next;
      } else if(cmp > 0) {
        /* item only in filesB, ignore it */
        pB = pB->next;
      } else {
        /* item in both, record it */
        ret = alpm_list_add(ret, strdup(strA));
        pA = pA->next;
        pB = pB->next;
      }
    }
  }

  return(ret);
}

/* Returns a alpm_list_t* of files that are in filesA but *NOT* in filesB
 *  This is an 'A minus B' set operation
 *  Pre-condition: both lists are sorted!
 */
static alpm_list_t *chk_filedifference(alpm_list_t *filesA, alpm_list_t *filesB)
{
  alpm_list_t *ret = NULL;
  alpm_list_t *pA = filesA, *pB = filesB;

  while(pA && pB) {
    const char *strA = pA->data;
    const char *strB = pB->data;
    /* skip directories, we don't care about dir conflicts */
    if(strA[strlen(strA)-1] == '/') {
      pA = pA->next;
    } else if(strB[strlen(strB)-1] == '/') {
      pB = pB->next;
    } else {
      int cmp = strcmp(strA, strB);
      if(cmp < 0) {
        /* item only in filesA, record it */
        ret = alpm_list_add(ret, strdup(strA));
        pA = pA->next;
      } else if(cmp > 0) {
        /* item only in fileB, but this means nothing */
        pB = pB->next;
      } else {
        /* item in both, ignore it */
        pA = pA->next;
        pB = pB->next;
      }
    }
  }

  return(ret);
}

/* Adds pmconflict_t to a conflicts list. Pass the conflicts list, type (either
 * PM_CONFLICT_TYPE_TARGET or PM_CONFLICT_TYPE_FILE), a file string, and either
 * two package names or one package name and NULL. This is a wrapper for former
 * functionality that was done inline.
 */
static alpm_list_t *add_fileconflict(alpm_list_t *conflicts,
                    pmconflicttype_t type, const char *filestr,
                    const char* name1, const char* name2)
{
  pmconflict_t *conflict;
  MALLOC(conflict, sizeof(pmconflict_t), return(conflicts));

  conflict->type = type;
  strncpy(conflict->target, name1, PKG_NAME_LEN);
  strncpy(conflict->file, filestr, CONFLICT_FILE_LEN);
  if(name2) {
    strncpy(conflict->ctarget, name2, PKG_NAME_LEN);
  } else {
    conflict->ctarget[0] = '\0';
  }

  conflicts = alpm_list_add(conflicts, conflict);
  _alpm_log(PM_LOG_DEBUG, "found file conflict %s, packages %s and %s\n",
            filestr, name1, name2 ? name2 : "(filesystem)");

  return(conflicts);
}

/* Find file conflicts that may occur during the transaction with two checks:
 * 1: check every target against every target
 * 2: check every target against the filesystem */
alpm_list_t *_alpm_db_find_conflicts(pmdb_t *db, pmtrans_t *trans, char *root)
{
  alpm_list_t *i, *conflicts = NULL;
  alpm_list_t *targets = trans->packages;
  int numtargs = alpm_list_count(targets);
  int current;

  ALPM_LOG_FUNC;

  if(db == NULL || targets == NULL || root == NULL) {
    return(NULL);
  }

  for(current = 1, i = targets; i; i = i->next, current++) {
    alpm_list_t *j, *k, *tmpfiles = NULL;
    pmpkg_t *p1, *p2, *dbpkg;
    char path[PATH_MAX+1];

    p1 = i->data;
    if(!p1) {
      continue;
    }

    double percent = (double)current / numtargs;
    PROGRESS(trans, PM_TRANS_PROGRESS_CONFLICTS_START, "", (percent * 100),
             numtargs, current);
    /* CHECK 1: check every target against every target */
    for(j = i->next; j; j = j->next) {
      p2 = j->data;
      if(!p2) {
        continue;
      }
      _alpm_log(PM_LOG_DEBUG, "searching for file conflicts: %s and %s\n",
                alpm_pkg_get_name(p1), alpm_pkg_get_name(p2));
      tmpfiles = chk_fileconflicts(alpm_pkg_get_files(p1), alpm_pkg_get_files(p2));

      if(tmpfiles) {
        for(k = tmpfiles; k; k = k->next) {
          snprintf(path, PATH_MAX, "%s%s", root, (char *)k->data);
          conflicts = add_fileconflict(conflicts, PM_CONFLICT_TYPE_TARGET, path,
                                       alpm_pkg_get_name(p1), alpm_pkg_get_name(p2));
        }
        alpm_list_free_inner(tmpfiles, &free);
        alpm_list_free(tmpfiles);
      }
    }

    /* declarations for second check */
    struct stat buf;
    char *filestr = NULL;

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

    /* Do two different checks here. f 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 */
    if(dbpkg) {
      /* older ver of package currently installed */
      tmpfiles = chk_filedifference(alpm_pkg_get_files(p1), alpm_pkg_get_files(dbpkg));
    } else {
      /* no version of package currently installed */
      tmpfiles = alpm_list_strdup(alpm_pkg_get_files(p1));
    }

    /* loop over each file to be installed */
    for(j = tmpfiles; j; j = j->next) {
      filestr = j->data;

      snprintf(path, PATH_MAX, "%s%s", root, filestr);

      /* stat the file - if it exists, do some checks */
      if(lstat(path, &buf) != 0) {
        continue;
      }
      if(S_ISDIR(buf.st_mode)) {
        _alpm_log(PM_LOG_DEBUG, "%s is a directory, not a conflict\n", path);
      } else {
        _alpm_log(PM_LOG_DEBUG, "checking possible conflict: %s\n", path);

        /* Make sure the possible conflict is not a symlink that points to a
         * path in the old package. This is kind of dirty with inode usage */
        if(dbpkg) {
          struct stat buf2;
          char str[PATH_MAX+1];
          unsigned ok = 0;
          for(k = dbpkg->files; k; k = k->next) {
            snprintf(str, PATH_MAX, "%s%s", root, (char*)k->data);
            if(!lstat(str, &buf2) && buf.st_ino == buf2.st_ino) {
              ok = 1;
              _alpm_log(PM_LOG_DEBUG, "conflict was a symlink: %s\n", path);
              break;
            }
          }
          if(ok == 1) {
            continue;
          }
        }

        /* Look at all the targets to see if file has changed hands */
        int resolved_conflict = 0; /* have we acted on this conflict? */
        for(k = targets; k; k = k->next) {
          p2 = k->data;
          if(!p2 || strcmp(p1->name, p2->name) == 0) {
            continue;
          }

          pmpkg_t *localp2 = _alpm_db_get_pkgfromcache(db, p2->name);

          /* Check if it used to exist in a package, but doesn't anymore */
          alpm_list_t *pkgfiles, *localfiles; /* added for readability */
          pkgfiles = alpm_pkg_get_files(p2);
          localfiles = alpm_pkg_get_files(localp2);

          if(localp2 && !alpm_list_find_str(pkgfiles, filestr)
             && alpm_list_find_str(localfiles, filestr)) {
            /* check if the file is now in the backup array */
            if(alpm_list_find_str(alpm_pkg_get_backup(p1), filestr)) {
              /* keep file intact if it is in backup array */
              trans->skip_add = alpm_list_add(trans->skip_add, strdup(path));
              trans->skip_remove = alpm_list_add(trans->skip_remove, strdup(path));
              _alpm_log(PM_LOG_DEBUG, "file in backup array, adding to add and remove skiplist: %s\n", filestr);
              resolved_conflict = 1;
              break;
            } else {
              /* 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 */
              trans->skip_remove = alpm_list_add(trans->skip_remove, strdup(path));
              _alpm_log(PM_LOG_DEBUG, "file changed packages, adding to remove skiplist: %s\n", filestr);
              resolved_conflict = 1;
              break;
            }
          }
        }
        if(!resolved_conflict) {
          _alpm_log(PM_LOG_DEBUG, "file found in conflict: %s\n", path);
          conflicts = add_fileconflict(conflicts, PM_CONFLICT_TYPE_FILE,
                                       path, p1->name, NULL);
        }
      }
    }
    alpm_list_free_inner(tmpfiles, &free);
    alpm_list_free(tmpfiles);
  }

  return(conflicts);
}

const char SYMEXPORT *alpm_conflict_get_target(pmconflict_t *conflict)
{
  ALPM_LOG_FUNC;

  /* Sanity checks */
  ASSERT(handle != NULL, return(NULL));
  ASSERT(conflict != NULL, return(NULL));

  return conflict->target;
}

pmconflicttype_t SYMEXPORT alpm_conflict_get_type(pmconflict_t *conflict)
{
  ALPM_LOG_FUNC;

  /* Sanity checks */
  ASSERT(handle != NULL, return(-1));
  ASSERT(conflict != NULL, return(-1));

  return conflict->type;
}

const char SYMEXPORT *alpm_conflict_get_file(pmconflict_t *conflict)
{
  ALPM_LOG_FUNC;

  /* Sanity checks */
  ASSERT(handle != NULL, return(NULL));
  ASSERT(conflict != NULL, return(NULL));

  return conflict->file;
}

const char SYMEXPORT *alpm_conflict_get_ctarget(pmconflict_t *conflict)
{
  ALPM_LOG_FUNC;

  /* Sanity checks */
  ASSERT(handle != NULL, return(NULL));
  ASSERT(conflict != NULL, return(NULL));

  return conflict->ctarget;
}
/* vim: set ts=2 sw=2 noet: */