path: root/lib/libalpm/be_sync.c

/*
 *  be_sync.c
 *
 *  Copyright (c) 2006-2011 Pacman Development Team <pacman-dev@archlinux.org>
 *  Copyright (c) 2002-2006 by Judd Vinet <jvinet@zeroflux.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 <sys/stat.h>

/* libarchive */
#include <archive.h>
#include <archive_entry.h>

/* libalpm */
#include "util.h"
#include "log.h"
#include "alpm.h"
#include "alpm_list.h"
#include "package.h"
#include "handle.h"
#include "delta.h"
#include "deps.h"
#include "dload.h"

/** Update a package database
 *
 * An update of the package database \a db will be attempted. Unless
 * \a force is true, the update will only be performed if the remote
 * database was modified since the last update.
 *
 * A transaction is necessary for this operation, in order to obtain a
 * database lock. During this transaction the front-end will be informed
 * of the download progress of the database via the download callback.
 *
 * Example:
 * @code
 * alpm_list_t *syncs = alpm_option_get_syncdbs();
 * if(alpm_trans_init(0, NULL, NULL, NULL) == 0) {
 *     for(i = syncs; i; i = alpm_list_next(i)) {
 *         pmdb_t *db = alpm_list_getdata(i);
 *         result = alpm_db_update(0, db);
 *         alpm_trans_release();
 *
 *         if(result < 0) {
 *             printf("Unable to update database: %s\n", alpm_strerrorlast());
 *         } else if(result == 1) {
 *             printf("Database already up to date\n");
 *         } else {
 *             printf("Database updated\n");
 *         }
 *     }
 * }
 * @endcode
 *
 * @ingroup alpm_databases
 * @note After a successful update, the \link alpm_db_get_pkgcache()
 * package cache \endlink will be invalidated
 * @param force if true, then forces the update, otherwise update only in case
 * the database isn't up to date
 * @param db pointer to the package database to update
 * @return 0 on success, -1 on error (pm_errno is set accordingly), 1 if up to
 * to date
 */
int SYMEXPORT alpm_db_update(int force, pmdb_t *db)
{
  char *dbfile, *syncpath;
  const char *dbpath;
  struct stat buf;
  size_t len;
  int ret;
  mode_t oldmask;

  ALPM_LOG_FUNC;

  /* Sanity checks */
  ASSERT(handle != NULL, RET_ERR(PM_ERR_HANDLE_NULL, -1));
  ASSERT(db != NULL && db != handle->db_local, RET_ERR(PM_ERR_WRONG_ARGS, -1));

  if(!alpm_list_find_ptr(handle->dbs_sync, db)) {
    RET_ERR(PM_ERR_DB_NOT_FOUND, -1);
  }

  len = strlen(db->treename) + 4;
  MALLOC(dbfile, len, RET_ERR(PM_ERR_MEMORY, -1));
  sprintf(dbfile, "%s.db", db->treename);

  dbpath = alpm_option_get_dbpath();
  len = strlen(dbpath) + 6;
  MALLOC(syncpath, len, RET_ERR(PM_ERR_MEMORY, -1));
  sprintf(syncpath, "%s%s", dbpath, "sync/");

  /* make sure we have a sane umask */
  oldmask = umask(0022);

  if(stat(syncpath, &buf) != 0) {
    _alpm_log(PM_LOG_DEBUG, "database dir '%s' does not exist, creating it\n",
        syncpath);
    if(_alpm_makepath(syncpath) != 0) {
      free(dbfile);
      free(syncpath);
      RET_ERR(PM_ERR_SYSTEM, -1);
    }
  } else if(!S_ISDIR(buf.st_mode)) {
    _alpm_log(PM_LOG_WARNING, _("removing invalid file: %s\n"), syncpath);
    if(unlink(syncpath) != 0 || _alpm_makepath(syncpath) != 0) {
      free(dbfile);
      free(syncpath);
      RET_ERR(PM_ERR_SYSTEM, -1);
    }
  }

  ret = _alpm_download_single_file(dbfile, db->servers, syncpath, force);

  if(ret == 1) {
    /* files match, do nothing */
    pm_errno = 0;
    goto cleanup;
  } else if(ret == -1) {
    /* pm_errno was set by the download code */
    _alpm_log(PM_LOG_DEBUG, "failed to sync db: %s\n", alpm_strerrorlast());
    goto cleanup;
  }

  /* Download and check the signature of the database if needed */
  if(db->pgp_verify != PM_PGP_VERIFY_NEVER) {
    char *sigfile, *sigfilepath;
    int sigret;

    len = strlen(dbfile) + 5;
    MALLOC(sigfile, len, RET_ERR(PM_ERR_MEMORY, -1));
    sprintf(sigfile, "%s.sig", dbfile);

    /* prevent old signature being used if the following download fails */
    len = strlen(syncpath) + strlen(sigfile) + 1;
    MALLOC(sigfilepath, len, RET_ERR(PM_ERR_MEMORY, -1));
    sprintf(sigfilepath, "%s%s", syncpath, sigfile);
    _alpm_rmrf(sigfilepath);
    free(sigfilepath);

    sigret = _alpm_download_single_file(sigfile, db->servers, syncpath, 0);
    free(sigfile);

    if(sigret == -1 && db->pgp_verify == PM_PGP_VERIFY_ALWAYS) {
      _alpm_log(PM_LOG_ERROR, _("Failed to download signature for db: %s\n"),
          alpm_strerrorlast());
      pm_errno = PM_ERR_SIG_INVALID;
      ret = -1;
      goto cleanup;
    }

    sigret = alpm_db_check_pgp_signature(db);
    if((db->pgp_verify == PM_PGP_VERIFY_ALWAYS && sigret != 0) ||
        (db->pgp_verify == PM_PGP_VERIFY_OPTIONAL && sigret == 1)) {
      /* pm_errno was set by the checking code */
      /* TODO: should we just leave the unverified database */
      ret = -1;
      goto cleanup;
    }
  }

  /* Cache needs to be rebuilt */
  _alpm_db_free_pkgcache(db);

cleanup:

  free(dbfile);
  free(syncpath);
  umask(oldmask);
  return ret;
}

/* Forward decl so I don't reorganize the whole file right now */
static int sync_db_read(pmdb_t *db, struct archive *archive,
    struct archive_entry *entry, pmpkg_t *likely_pkg);

/*
 * This is the data table used to generate the estimating function below.
 * "Weighted Avg" means averaging the bottom table values; thus each repo, big
 * or small, will have equal influence.  "Unweighted Avg" means averaging the
 * sums of the top table columns, thus each package has equal influence.  The
 * final values are calculated by (surprise) averaging the averages, because
 * why the hell not.
 *
 * Database   Pkgs  tar      bz2     gz      xz
 * community  2096  5294080  256391  421227  301296
 * core        180   460800   25257   36850   29356
 * extra      2606  6635520  294647  470818  339392
 * multilib    126   327680   16120   23261   18732
 * testing      76   204800   10902   14348   12100
 *
 * Bytes Per Package
 * community  2096  2525.80  122.32  200.97  143.75
 * core        180  2560.00  140.32  204.72  163.09
 * extra      2606  2546.25  113.06  180.67  130.23
 * multilib    126  2600.63  127.94  184.61  148.67
 * testing      76  2694.74  143.45  188.79  159.21

 * Weighted Avg     2585.48  129.42  191.95  148.99
 * Unweighted Avg   2543.39  118.74  190.16  137.93
 * Average of Avgs  2564.44  124.08  191.06  143.46
 */
static size_t estimate_package_count(struct stat *st, struct archive *archive)
{
  unsigned int per_package;

  switch(archive_compression(archive)) {
    case ARCHIVE_COMPRESSION_NONE:
      per_package = 2564;
      break;
    case ARCHIVE_COMPRESSION_GZIP:
      per_package = 191;
      break;
    case ARCHIVE_COMPRESSION_BZIP2:
      per_package = 124;
      break;
    case ARCHIVE_COMPRESSION_COMPRESS:
      per_package = 193;
      break;
    case ARCHIVE_COMPRESSION_LZMA:
    case ARCHIVE_COMPRESSION_XZ:
      per_package = 143;
      break;
#ifdef ARCHIVE_COMPRESSION_UU
    case ARCHIVE_COMPRESSION_UU:
      per_package = 3543;
      break;
#endif
    default:
      /* assume it is at least somewhat compressed */
      per_package = 200;
  }
  return (size_t)((st->st_size / per_package) + 1);
}

static int sync_db_populate(pmdb_t *db)
{
  const char *dbpath;
  size_t est_count;
  int count = 0;
  struct stat buf;
  struct archive *archive;
  struct archive_entry *entry;
  pmpkg_t *pkg = NULL;

  ALPM_LOG_FUNC;

  ASSERT(db != NULL, RET_ERR(PM_ERR_DB_NULL, -1));

  if((archive = archive_read_new()) == NULL)
    RET_ERR(PM_ERR_LIBARCHIVE, 1);

  archive_read_support_compression_all(archive);
  archive_read_support_format_all(archive);

  dbpath = _alpm_db_path(db);
  if(!dbpath) {
    /* pm_errno set in _alpm_db_path() */
    return 1;
  }

  _alpm_log(PM_LOG_DEBUG, "opening database archive %s\n", dbpath);

  if(archive_read_open_filename(archive, dbpath,
        ARCHIVE_DEFAULT_BYTES_PER_BLOCK) != ARCHIVE_OK) {
    _alpm_log(PM_LOG_ERROR, _("could not open file %s: %s\n"), dbpath,
        archive_error_string(archive));
    archive_read_finish(archive);
    RET_ERR(PM_ERR_DB_OPEN, 1);
  }
  if(stat(dbpath, &buf) != 0) {
    RET_ERR(PM_ERR_DB_OPEN, 1);
  }
  est_count = estimate_package_count(&buf, archive);

  /* initialize hash at 66% full */
  db->pkgcache = _alpm_pkghash_create(est_count * 3 / 2);
  if(db->pkgcache == NULL) {
    RET_ERR(PM_ERR_MEMORY, -1);
  }

  while(archive_read_next_header(archive, &entry) == ARCHIVE_OK) {
    const struct stat *st;

    st = archive_entry_stat(entry);

    if(S_ISDIR(st->st_mode)) {
      const char *name;

      pkg = _alpm_pkg_new();
      if(pkg == NULL) {
        archive_read_finish(archive);
        RET_ERR(PM_ERR_MEMORY, -1);
      }

      name = archive_entry_pathname(entry);

      if(_alpm_splitname(name, pkg) != 0) {
        _alpm_log(PM_LOG_ERROR, _("invalid name for database entry '%s'\n"),
            name);
        _alpm_pkg_free(pkg);
        continue;
      }

      /* duplicated database entries are not allowed */
      if(_alpm_pkghash_find(db->pkgcache, pkg->name)) {
        _alpm_log(PM_LOG_ERROR, _("duplicated database entry '%s'\n"), pkg->name);
        _alpm_pkg_free(pkg);
        continue;
      }

      pkg->origin = PKG_FROM_SYNCDB;
      pkg->ops = &default_pkg_ops;
      pkg->origin_data.db = db;

      /* add to the collection */
      _alpm_log(PM_LOG_FUNCTION, "adding '%s' to package cache for db '%s'\n",
          pkg->name, db->treename);
      db->pkgcache = _alpm_pkghash_add(db->pkgcache, pkg);
      count++;
    } else {
      /* we have desc, depends or deltas - parse it */
      sync_db_read(db, archive, entry, pkg);
    }
  }

  if(count > 0) {
    db->pkgcache->list = alpm_list_msort(db->pkgcache->list, (size_t)count, _alpm_pkg_cmp);
  }
  archive_read_finish(archive);

  return count;
}

#define READ_NEXT(s) do { \
  if(_alpm_archive_fgets(archive, &buf) != ARCHIVE_OK) goto error; \
  s = _alpm_strtrim(buf.line); \
} while(0)

#define READ_AND_STORE(f) do { \
  READ_NEXT(line); \
  STRDUP(f, line, goto error); \
} while(0)

#define READ_AND_STORE_ALL(f) do { \
  char *linedup; \
  READ_NEXT(line); \
  if(strlen(line) == 0) break; \
  STRDUP(linedup, line, goto error); \
  f = alpm_list_add(f, linedup); \
} while(1) /* note the while(1) and not (0) */

static int sync_db_read(pmdb_t *db, struct archive *archive,
    struct archive_entry *entry, pmpkg_t *likely_pkg)
{
  const char *entryname = NULL, *filename;
  char *pkgname, *p, *q;
  pmpkg_t *pkg;
  struct archive_read_buffer buf;

  ALPM_LOG_FUNC;

  if(db == NULL) {
    RET_ERR(PM_ERR_DB_NULL, -1);
  }

  if(entry != NULL) {
    entryname = archive_entry_pathname(entry);
  }
  if(entryname == NULL) {
    _alpm_log(PM_LOG_DEBUG, "invalid archive entry provided to _alpm_sync_db_read, skipping\n");
    return -1;
  }

  _alpm_log(PM_LOG_FUNCTION, "loading package data from archive entry %s\n",
      entryname);

  memset(&buf, 0, sizeof(buf));
  /* 512K for a line length seems reasonable */
  buf.max_line_size = 512 * 1024;

  /* get package and db file names */
  STRDUP(pkgname, entryname, RET_ERR(PM_ERR_MEMORY, -1));
  p = pkgname + strlen(pkgname);
  for(q = --p; *q && *q != '/'; q--);
  filename = q + 1;
  for(p = --q; *p && *p != '-'; p--);
  for(q = --p; *q && *q != '-'; q--);
  *q = '\0';

  /* package is already in db due to parsing of directory name */
  if(likely_pkg && strcmp(likely_pkg->name, pkgname) == 0) {
    pkg = likely_pkg;
  } else {
    if(db->pkgcache == NULL) {
      RET_ERR(PM_ERR_MEMORY, -1);
    }
    pkg = _alpm_pkghash_find(db->pkgcache, pkgname);
  }
  if(pkg == NULL) {
    _alpm_log(PM_LOG_DEBUG, "package %s not found in %s sync database",
          pkgname, db->treename);
    return -1;
  }

  if(strcmp(filename, "desc") == 0 || strcmp(filename, "depends") == 0
      || strcmp(filename, "deltas") == 0) {
    while(_alpm_archive_fgets(archive, &buf) == ARCHIVE_OK) {
      char *line = _alpm_strtrim(buf.line);

      if(strcmp(line, "%NAME%") == 0) {
        READ_NEXT(line);
        if(strcmp(line, pkg->name) != 0) {
          _alpm_log(PM_LOG_ERROR, _("%s database is inconsistent: name "
                "mismatch on package %s\n"), db->treename, pkg->name);
        }
      } else if(strcmp(line, "%VERSION%") == 0) {
        READ_NEXT(line);
        if(strcmp(line, pkg->version) != 0) {
          _alpm_log(PM_LOG_ERROR, _("%s database is inconsistent: version "
                "mismatch on package %s\n"), db->treename, pkg->name);
        }
      } else if(strcmp(line, "%FILENAME%") == 0) {
        READ_AND_STORE(pkg->filename);
      } else if(strcmp(line, "%DESC%") == 0) {
        READ_AND_STORE(pkg->desc);
      } else if(strcmp(line, "%GROUPS%") == 0) {
        READ_AND_STORE_ALL(pkg->groups);
      } else if(strcmp(line, "%URL%") == 0) {
        READ_AND_STORE(pkg->url);
      } else if(strcmp(line, "%LICENSE%") == 0) {
        READ_AND_STORE_ALL(pkg->licenses);
      } else if(strcmp(line, "%ARCH%") == 0) {
        READ_AND_STORE(pkg->arch);
      } else if(strcmp(line, "%BUILDDATE%") == 0) {
        READ_NEXT(line);
        pkg->builddate = _alpm_parsedate(line);
      } else if(strcmp(line, "%PACKAGER%") == 0) {
        READ_AND_STORE(pkg->packager);
      } else if(strcmp(line, "%CSIZE%") == 0) {
        /* Note: the CSIZE and SIZE fields both share the "size" field in the
         * pkginfo_t struct. This can be done b/c CSIZE is currently only used
         * in sync databases, and SIZE is only used in local databases.
         */
        READ_NEXT(line);
        pkg->size = atol(line);
        /* also store this value to isize if isize is unset */
        if(pkg->isize == 0) {
          pkg->isize = pkg->size;
        }
      } else if(strcmp(line, "%ISIZE%") == 0) {
        READ_NEXT(line);
        pkg->isize = atol(line);
      } else if(strcmp(line, "%MD5SUM%") == 0) {
        READ_AND_STORE(pkg->md5sum);
      } else if(strcmp(line, "%SHA256SUM%") == 0) {
        /* we don't do anything with this value right now */
        READ_NEXT(line);
      } else if(strcmp(line, "%PGPSIG%") == 0) {
        READ_AND_STORE(pkg->pgpsig.base64_data);
      } else if(strcmp(line, "%REPLACES%") == 0) {
        READ_AND_STORE_ALL(pkg->replaces);
      } else if(strcmp(line, "%DEPENDS%") == 0) {
        /* Different than the rest because of the _alpm_splitdep call. */
        while(1) {
          READ_NEXT(line);
          if(strlen(line) == 0) break;
          pkg->depends = alpm_list_add(pkg->depends, _alpm_splitdep(line));
        }
      } else if(strcmp(line, "%OPTDEPENDS%") == 0) {
        READ_AND_STORE_ALL(pkg->optdepends);
      } else if(strcmp(line, "%CONFLICTS%") == 0) {
        READ_AND_STORE_ALL(pkg->conflicts);
      } else if(strcmp(line, "%PROVIDES%") == 0) {
        READ_AND_STORE_ALL(pkg->provides);
      } else if(strcmp(line, "%DELTAS%") == 0) {
        /* Different than the rest because of the _alpm_delta_parse call. */
        while(1) {
          READ_NEXT(line);
          if(strlen(line) == 0) break;
          pkg->deltas = alpm_list_add(pkg->deltas, _alpm_delta_parse(line));
        }
      }
    }
  } else if(strcmp(filename, "files") == 0) {
    /* currently do nothing with this file */
  } else {
    /* unknown database file */
    _alpm_log(PM_LOG_DEBUG, "unknown database file: %s\n", filename);
  }

error:
  FREE(pkgname);
  /* TODO: return 0 always? */
  return 0;
}

static int sync_db_version(pmdb_t *db)
{
  return 2;
}

struct db_operations sync_db_ops = {
  .populate         = sync_db_populate,
  .unregister       = _alpm_db_unregister,
  .version          = sync_db_version,
};

pmdb_t *_alpm_db_register_sync(const char *treename)
{
  pmdb_t *db;
  alpm_list_t *i;

  ALPM_LOG_FUNC;

  for(i = handle->dbs_sync; i; i = i->next) {
    pmdb_t *sdb = i->data;
    if(strcmp(treename, sdb->treename) == 0) {
      _alpm_log(PM_LOG_DEBUG, "attempt to re-register the '%s' database, using existing\n", sdb->treename);
      return sdb;
    }
  }

  _alpm_log(PM_LOG_DEBUG, "registering sync database '%s'\n", treename);

  db = _alpm_db_new(treename, 0);
  if(db == NULL) {
    RET_ERR(PM_ERR_DB_CREATE, NULL);
  }
  db->ops = &sync_db_ops;

  handle->dbs_sync = alpm_list_add(handle->dbs_sync, db);
  return db;
}


/* vim: set ts=2 sw=2 noet: */