Check local DB version before continuing transaction

Ensure we have a local DB version that is up to par with what we expect
before we go down any road that might modify it. This should prevent
stupid mistakes with the 3.5.X upgrade and people not running
pacman-db-upgrade after the transaction as they will need to.

Signed-off-by: Dan McGee <dan@archlinux.org>

8 files changed, 88 insertions, 3 deletions

diff --git a/lib/libalpm/alpm.c b/lib/libalpm/alpm.c
index 7c3bfc26..4f95832d 100644
--- a/lib/libalpm/alpm.c
+++ b/lib/libalpm/alpm.c
@@ -56,6 +56,8 @@ int SYMEXPORT alpm_initialize(void)
 	}
 	if(_alpm_db_register_local() == NULL) {
 		/* error code should be set */
+		_alpm_handle_free(handle);
+		handle = NULL;
 		return(-1);
 	}
 
diff --git a/lib/libalpm/alpm.h b/lib/libalpm/alpm.h
index cf3a9135..0f3b7166 100644
--- a/lib/libalpm/alpm.h
+++ b/lib/libalpm/alpm.h
@@ -497,6 +497,7 @@ enum _pmerrno_t {
 	PM_ERR_DB_NULL,
 	PM_ERR_DB_NOT_NULL,
 	PM_ERR_DB_NOT_FOUND,
+	PM_ERR_DB_VERSION,
 	PM_ERR_DB_WRITE,
 	PM_ERR_DB_REMOVE,
 	/* Servers */
diff --git a/lib/libalpm/be_local.c b/lib/libalpm/be_local.c
index c1e86a63..848ecc58 100644
--- a/lib/libalpm/be_local.c
+++ b/lib/libalpm/be_local.c
@@ -924,9 +924,62 @@ int _alpm_local_db_remove(pmdb_t *db, pmpkg_t *info)
 	return(ret);
 }
 
+static int local_db_version(pmdb_t *db)
+{
+	struct dirent *ent = NULL;
+	const char *dbpath;
+	DIR *dbdir;
+	int version;
+
+	dbpath = _alpm_db_path(db);
+	if(dbpath == NULL) {
+		RET_ERR(PM_ERR_DB_OPEN, -1);
+	}
+	dbdir = opendir(dbpath);
+	if(dbdir == NULL) {
+		if(errno == ENOENT) {
+			/* database dir doesn't exist yet */
+			version = 2;
+			goto done;
+		} else {
+			RET_ERR(PM_ERR_DB_OPEN, -1);
+		}
+	}
+
+	while((ent = readdir(dbdir)) != NULL) {
+		const char *name = ent->d_name;
+		char path[PATH_MAX];
+
+		if(strcmp(name, ".") == 0 || strcmp(name, "..") == 0) {
+			continue;
+		}
+		if(!is_dir(dbpath, ent)) {
+			continue;
+		}
+
+		snprintf(path, PATH_MAX, "%s%s/depends", dbpath, name);
+		if(access(path, F_OK) == 0) {
+			/* we found a depends file- bail */
+			version = 1;
+			goto done;
+		}
+	}
+	/* we found no depends file after full scan */
+	version = 2;
+
+done:
+	if(dbdir) {
+		closedir(dbdir);
+	}
+
+	_alpm_log(PM_LOG_DEBUG, "local database version %d\n", version);
+	return(version);
+}
+
 struct db_operations local_db_ops = {
 	.populate         = local_db_populate,
 	.unregister       = _alpm_db_unregister,
+	.version          = local_db_version,
 };
 
 pmdb_t *_alpm_db_register_local(void)
diff --git a/lib/libalpm/be_sync.c b/lib/libalpm/be_sync.c
index 69f7663d..21914944 100644
--- a/lib/libalpm/be_sync.c
+++ b/lib/libalpm/be_sync.c
@@ -443,9 +443,15 @@ error:
 	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)
diff --git a/lib/libalpm/db.c b/lib/libalpm/db.c
index 2a8db8e0..fb64faed 100644
--- a/lib/libalpm/db.c
+++ b/lib/libalpm/db.c
@@ -405,6 +405,14 @@ const char *_alpm_db_path(pmdb_t *db)
 	return(db->_path);
 }
 
+int _alpm_db_version(pmdb_t *db)
+{
+	if(!db) {
+		return(-1);
+	}
+	return(db->ops->version(db));
+}
+
 int _alpm_db_cmp(const void *d1, const void *d2)
 {
 	pmdb_t *db1 = (pmdb_t *)d1;
diff --git a/lib/libalpm/db.h b/lib/libalpm/db.h
index a530a2e9..75776d71 100644
--- a/lib/libalpm/db.h
+++ b/lib/libalpm/db.h
@@ -45,6 +45,7 @@ typedef enum _pmdbinfrq_t {
 struct db_operations {
 	int (*populate) (pmdb_t *);
 	void (*unregister) (pmdb_t *);
+	int (*version) (pmdb_t *);
 };
 
 /* Database */
@@ -65,14 +66,15 @@ struct __pmdb_t {
 
 
 /* db.c, database general calls */
+pmdb_t *_alpm_db_new(const char *treename, int is_local);
 void _alpm_db_free(pmdb_t *db);
 const char *_alpm_db_path(pmdb_t *db);
+int _alpm_db_version(pmdb_t *db);
 int _alpm_db_cmp(const void *d1, const void *d2);
 alpm_list_t *_alpm_db_search(pmdb_t *db, const alpm_list_t *needles);
 pmdb_t *_alpm_db_register_local(void);
 pmdb_t *_alpm_db_register_sync(const char *treename);
 void _alpm_db_unregister(pmdb_t *db);
-pmdb_t *_alpm_db_new(const char *treename, int is_local);
 
 /* be_*.c, backend specific calls */
 int _alpm_local_db_read(pmdb_t *db, pmpkg_t *info, pmdbinfrq_t inforeq);
diff --git a/lib/libalpm/error.c b/lib/libalpm/error.c
index 2cc66851..21fbb48f 100644
--- a/lib/libalpm/error.c
+++ b/lib/libalpm/error.c
@@ -77,6 +77,8 @@ const char SYMEXPORT *alpm_strerror(int err)
 			return _("database already registered");
 		case PM_ERR_DB_NOT_FOUND:
 			return _("could not find database");
+		case PM_ERR_DB_VERSION:
+			return _("database is incorrect version");
 		case PM_ERR_DB_WRITE:
 			return _("could not update database");
 		case PM_ERR_DB_REMOVE:
diff --git a/lib/libalpm/trans.c b/lib/libalpm/trans.c
index 8e47f377..4b29f9a8 100644
--- a/lib/libalpm/trans.c
+++ b/lib/libalpm/trans.c
@@ -105,10 +105,12 @@ static int remove_lock(pmhandle_t *handle)
  * @return 0 on success, -1 on error (pm_errno is set accordingly)
  */
 int SYMEXPORT alpm_trans_init(pmtransflag_t flags,
-                              alpm_trans_cb_event event, alpm_trans_cb_conv conv,
-                              alpm_trans_cb_progress progress)
+		alpm_trans_cb_event event, alpm_trans_cb_conv conv,
+		alpm_trans_cb_progress progress)
 {
 	pmtrans_t *trans;
+	const int required_db_version = 2;
+	int db_version;
 
 	ALPM_LOG_FUNC;
 
@@ -124,6 +126,15 @@ int SYMEXPORT alpm_trans_init(pmtransflag_t flags,
 		}
 	}
 
+	/* check database version */
+	db_version = _alpm_db_version(handle->db_local);
+	if(db_version < required_db_version) {
+		_alpm_log(PM_LOG_ERROR,
+				_("%s database version is too old\n"), handle->db_local->treename);
+		remove_lock(handle);
+		RET_ERR(PM_ERR_DB_VERSION, -1);
+	}
+
 	trans = _alpm_trans_new();
 	if(trans == NULL) {
 		RET_ERR(PM_ERR_MEMORY, -1);