dblib.c

在Linux/Unix下面访问WINDOWS SQLSERVER 的ODBC驱动程序

static char *
dbstring_get(DBSTRING * dbstr)
{
	DBSTRING *next;
	int len;
	char *ret;
	char *cp;

	/* tdsdump_log(TDS_DBG_FUNC, "dbstring_get(%p)\n", dbstr); */

	if (dbstr == NULL) {
		return NULL;
	}
	len = dbstring_length(dbstr);
	if ((ret = malloc(len + 1)) == NULL) {
		dbperror(NULL, SYBEMEM, errno);
		return NULL;
	}
	cp = ret;
	for (next = dbstr; next != NULL; next = next->strnext) {
		memcpy(cp, next->strtext, next->strtotlen);
		cp += next->strtotlen;
	}
	*cp = '\0';
	return ret;
}

static const char *const opttext[DBNUMOPTIONS] = {
	"parseonly",
	"estimate",
	"showplan",
	"noexec",
	"arithignore",
	"nocount",
	"arithabort",
	"textlimit",
	"browse",
	"offsets",
	"statistics",
	"errlvl",
	"confirm",
	"spid",
	"buffer",
	"noautofree",
	"rowcount",
	"textsize",
	"language",
	"dateformat",
	"prpad",
	"prcolsep",
	"prlinelen",
	"prlinesep",
	"lfconvert",
	"datefirst",
	"chained",
	"fipsflagger",
	"transaction isolation level",
	"auth",
	"identity_insert",
	"no_identity_column",
	"cnv_date2char_short",
	"client cursors",
	"set time",
	"quoted_identifier"
};

static DBOPTION *
init_dboptions(void)
{
	DBOPTION *dbopts;
	int i;

	if ((dbopts = calloc(DBNUMOPTIONS, sizeof(DBOPTION))) == NULL) {
		dbperror(NULL, SYBEMEM, errno);
		return NULL;
	}
	for (i = 0; i < DBNUMOPTIONS; i++) {
		tds_strlcpy(dbopts[i].text, opttext[i], sizeof(dbopts[i].text));
		dbopts[i].param = NULL;
		dbopts[i].factive = FALSE;
	}
	dbstring_assign(&(dbopts[DBPRPAD].param), " ");
	dbstring_assign(&(dbopts[DBPRCOLSEP].param), " ");
	dbstring_assign(&(dbopts[DBPRLINELEN].param), "80");
	dbstring_assign(&(dbopts[DBPRLINESEP].param), "\n");
	dbstring_assign(&(dbopts[DBCLIENTCURSORS].param), " ");
	dbstring_assign(&(dbopts[DBSETTIME].param), " ");
	return dbopts;
}

/** \internal
 * \ingroup dblib_internal
 * \brief Form a connection with the server.
 *   
 * Called by the \c dbopen() macro, normally.  If FreeTDS was configured with \c --enable-msdblib, this
 * function is called by (exported) \c dbopen() function.  \c tdsdbopen is so-named to avoid
 * namespace conflicts with other database libraries that use the same function name.  
 * \param login \c LOGINREC* carrying the account information.
 * \param server name of the dataserver to connect to.  
 * \return valid pointer on successful login.  
 * \retval NULL insufficient memory, unable to connect for any reason.
 * \sa dbopen()
 * \todo use \c asprintf() to avoid buffer overflow.
 * \todo separate error messages for \em no-such-server and \em no-such-user. 
 */
DBPROCESS *
tdsdbopen(LOGINREC * login, const char *server, int msdblib)
{
	DBPROCESS *dbproc;
	TDSCONNECTION *connection;

	tdsdump_log(TDS_DBG_FUNC, "dbopen(%p, %s, [%s])\n", login, server, msdblib? "microsoft" : "sybase");

	if ((dbproc = calloc(1, sizeof(DBPROCESS))) == NULL) {
		dbperror(NULL, SYBEMEM, errno);
		return NULL;
	}
	dbproc->msdblib = msdblib;

	dbproc->dbopts = init_dboptions();
	if (dbproc->dbopts == NULL) {
		free(dbproc);
		return NULL;
	}
	
	dbproc->dboptcmd = NULL;
	dbproc->avail_flag = TRUE;
	dbproc->command_state = DBCMDNONE;

	tds_set_server(login->tds_login, server);

	dbproc->tds_socket = tds_alloc_socket(dblib_get_tds_ctx(), 512);

	tds_set_parent(dbproc->tds_socket, dbproc);
	dbproc->tds_socket->option_flag2 &= ~0x02;	/* we're not an ODBC driver */
	dbproc->tds_socket->env_chg_func = db_env_chg;
	dbproc->envchange_rcv = 0;
	dbproc->dbcurdb[0] = '\0';
	dbproc->servcharset[0] = '\0';

	connection = tds_read_config_info(NULL, login->tds_login, g_dblib_ctx.tds_ctx->locale);
	if (!connection) {
		dbclose(dbproc);
		return NULL;
	}

	dbproc->chkintr = NULL;
	dbproc->hndlintr = NULL;

	TDS_MUTEX_LOCK(&dblib_mutex);

	/* override connection timeout if dbsetlogintime() was called */
	if (g_dblib_ctx.login_timeout > 0) {
		connection->connect_timeout = g_dblib_ctx.login_timeout;
	}

	/* override query timeout if dbsettime() was called */
	if (g_dblib_ctx.query_timeout > 0) {
		connection->query_timeout = g_dblib_ctx.query_timeout;
	}

	TDS_MUTEX_UNLOCK(&dblib_mutex);

	if (tds_connect(dbproc->tds_socket, connection) == TDS_FAIL) {
		tds_free_connection(connection);
		dbclose(dbproc);
		return NULL;
	}
	tds_free_connection(connection);

	dbproc->dbbuf = NULL;
	dbproc->dbbufsz = 0;

	TDS_MUTEX_LOCK(&dblib_mutex);
	dblib_add_connection(&g_dblib_ctx, dbproc->tds_socket);
	TDS_MUTEX_UNLOCK(&dblib_mutex);

	/* set the DBBUFFER capacity to nil */
	buffer_set_capacity(dbproc, 0);

	TDS_MUTEX_LOCK(&dblib_mutex);

	if (g_dblib_ctx.recftos_filename != NULL) {
		char *temp_filename = NULL;
		const int len = asprintf(&temp_filename, "%s.%d", 
					 g_dblib_ctx.recftos_filename, g_dblib_ctx.recftos_filenum);
		if (len >= 0) {
			dbproc->ftos = fopen(temp_filename, "w");
			if (dbproc->ftos != NULL) {
				fprintf(dbproc->ftos, "/* dbopen() at %s */\n", _dbprdate(temp_filename));
				fflush(dbproc->ftos);
				g_dblib_ctx.recftos_filenum++;
			}
			free(temp_filename);
		}
	}
	
	memcpy(dbproc->nullreps, default_null_representations, sizeof(default_null_representations));

	TDS_MUTEX_UNLOCK(&dblib_mutex);

	return dbproc;
}

/**
 * \ingroup dblib_core
 * \brief \c printf-like way to form SQL to send to the server.  
 *
 * Forms a command string and writes to the command buffer with dbcmd().  
 * \param dbproc contains all information needed by db-lib to manage communications with the server.
 * \param fmt <tt> man vasprintf</tt> for details.  
 * \retval SUCCEED success.
 * \retval FAIL insufficient memory, or dbcmd() failed.
 * \sa dbcmd(), dbfreebuf(), dbgetchar(), dbopen(), dbstrcpy(), dbstrlen().
 */
RETCODE
dbfcmd(DBPROCESS * dbproc, const char *fmt, ...)
{
	va_list ap;
	char *s;
	int len;
	RETCODE ret;

	tdsdump_log(TDS_DBG_FUNC, "dbfcmd(%p, %s, ...)\n", dbproc, fmt);
	CHECK_DBPROC();
	DBPERROR_RETURN(IS_TDSDEAD(dbproc->tds_socket), SYBEDDNE);
	CHECK_NULP(fmt, "dbfcmd", 2, FAIL);
	
	va_start(ap, fmt);
	len = vasprintf(&s, fmt, ap);
	va_end(ap);

	if (len < 0) {
		dbperror(NULL, SYBEMEM, errno);
		return FAIL;
	}

	ret = dbcmd(dbproc, s);
	free(s);

	return ret;
}

/**
 * \ingroup dblib_core
 * \brief \c Append SQL to the command buffer.  
 *
 * \param dbproc contains all information needed by db-lib to manage communications with the server.
 * \param cmdstring SQL to append to the command buffer.  
 * \retval SUCCEED success.
 * \retval FAIL insufficient memory.  
 * \remarks set command state to \c  DBCMDPEND unless the command state is DBCMDSENT, in which case 
 * it frees the command buffer.  This latter may or may not be the Right Thing to do.  
 * \sa dbfcmd(), dbfreebuf(), dbgetchar(), dbopen(), dbstrcpy(), dbstrlen().
 */
RETCODE
dbcmd(DBPROCESS * dbproc, const char *cmdstring)
{
	int newsz;
	void *p;

	tdsdump_log(TDS_DBG_FUNC, "dbcmd(%p, %s)\n", dbproc, cmdstring);
	CHECK_DBPROC();
	DBPERROR_RETURN(IS_TDSDEAD(dbproc->tds_socket), SYBEDDNE);
	CHECK_NULP(cmdstring, "dbcmd", 2, FAIL);

	dbproc->avail_flag = FALSE;

	tdsdump_log(TDS_DBG_FUNC, "dbcmd() bufsz = %d\n", dbproc->dbbufsz);

	if (dbproc->command_state == DBCMDSENT) {
		if (!dbproc->noautofree) {
			dbfreebuf(dbproc);
		}
	}

	if (dbproc->dbbufsz == 0) {
		dbproc->dbbuf = malloc(strlen(cmdstring) + 1);
		if (dbproc->dbbuf == NULL) {
			dbperror(NULL, SYBEMEM, errno);
			return FAIL;
		}
		strcpy((char *) dbproc->dbbuf, cmdstring);
		dbproc->dbbufsz = strlen(cmdstring) + 1;
	} else {
		newsz = strlen(cmdstring) + dbproc->dbbufsz;
		if ((p = realloc(dbproc->dbbuf, newsz)) == NULL) {
			dbperror(NULL, SYBEMEM, errno);
			return FAIL;
		}
		dbproc->dbbuf = (unsigned char *) p;
		strcat((char *) dbproc->dbbuf, cmdstring);
		dbproc->dbbufsz = newsz;
	}

	dbproc->command_state = DBCMDPEND;

	return SUCCEED;
}

/**
 * \ingroup dblib_core
 * \brief send the SQL command to the server and wait for an answer.  
 * 
 * Please be patient.  This function waits for the server to respond.   \c dbsqlexec is equivalent
 * to dbsqlsend() followed by dbsqlok(). 
 * \param dbproc contains all information needed by db-lib to manage communications with the server.
 * \retval SUCCEED query was processed without errors.
 * \retval FAIL was returned by dbsqlsend() or dbsqlok().
 * \sa dbcmd(), dbfcmd(), dbnextrow(), dbresults(), dbretstatus(), dbsettime(), dbsqlok(), dbsqlsend()
 */
RETCODE
dbsqlexec(DBPROCESS * dbproc)
{
	RETCODE rc = FAIL;

	tdsdump_log(TDS_DBG_FUNC, "dbsqlexec(%p)\n", dbproc);
	CHECK_DBPROC();
	DBPERROR_RETURN(IS_TDSDEAD(dbproc->tds_socket), SYBEDDNE);

	if (SUCCEED == (rc = dbsqlsend(dbproc))) {
		rc = dbsqlok(dbproc);
	}
	return rc;
}

/**
 * \ingroup dblib_core
 * \brief Change current database. 
 * 
 * Analagous to the unix command \c cd, dbuse() makes \a name the default database.  Waits for an answer
 * from the server.  
 * \param dbproc contains all information needed by db-lib to manage communications with the server.
 * \param name database to use.
 * \retval SUCCEED query was processed without errors.
 * \retval FAIL query was not processed
 * \todo \a name should be quoted.
 * \sa dbchange(), dbname().
 */
RETCODE
dbuse(DBPROCESS * dbproc, const char *name)
{
	RETCODE rc;
	char *query;

	tdsdump_log(TDS_DBG_FUNC, "dbuse(%p, %s)\n", dbproc, name);
	CHECK_DBPROC();
	DBPERROR_RETURN(IS_TDSDEAD(dbproc->tds_socket), SYBEDDNE);
	CHECK_NULP(name, "dbuse", 2, FAIL);

	if (!dbproc->tds_socket)
		return FAIL;

	/* quote name */
	query = malloc(tds_quote_id(dbproc->tds_socket, NULL, name, -1) + 6);
	if (!query) {
		dbperror(NULL, SYBEMEM, errno);
		return FAIL;
	}
	strcpy(query, "use ");
	/* TODO PHP suggest to quote by yourself with []... what should I do ?? quote or not ?? */
	if (name[0] == '[' && name[strlen(name)-1] == ']')
		strcat(query, name);
	else
		tds_quote_id(dbproc->tds_socket, query + 4, name, -1);

	rc = SUCCEED;
	if ((dbcmd(dbproc, query) == FAIL)
	    || (dbsqlexec(dbproc) == FAIL)
	    || (dbresults(dbproc) == FAIL)
	    || (dbcanquery(dbproc) == FAIL))
		rc = FAIL;
	free(query);
	return rc;
}

/**
 * \ingroup dblib_core
 * \brief Close a connection to the server and free associated resources.  
 * 
 * \param dbproc contains all information needed by db-lib to manage communications with the server.
 * \sa dbexit(), dbopen().
 */
void
dbclose(DBPROCESS * dbproc)
{
	TDSSOCKET *tds;
	int i;
	char timestr[256];

	tdsdump_log(TDS_DBG_FUNC, "dbclose(%p)\n", dbproc);	
	CHECK_PARAMETER(dbproc, SYBENULL, );

	tds = dbproc->tds_socket;
	if (tds) {
		/* 
		 * this MUST be done before socket destruction
		 * it is possible that a TDSSOCKET is allocated on same position
		 */
		TDS_MUTEX_LOCK(&dblib_mutex);
		dblib_del_connection(&g_dblib_ctx, dbproc->tds_socket);
		TDS_MUTEX_UNLOCK(&dblib_mutex);

		tds_free_socket(tds);
		dblib_release_tds_ctx(1);
	}
	buffer_free(&(dbproc->row_buf));

	if (dbproc->ftos != NULL) {
		fprintf(dbproc->ftos, "/* dbclose() at %s */\n", _dbprdate(timestr));
		fclose(dbproc->ftos);
	}

	if (dbproc->bcpinfo)
		free(dbproc->bcpinfo->tablename);
	if (dbproc->hostfileinfo) {
		free(dbproc->hostfileinfo->hostfile);
		free(dbproc->hostfileinfo->errorfile);
		if (dbproc->hostfileinfo->host_columns) {
			for (i = 0; i < dbproc->hostfileinfo->host_colcount; i++) {
				free(dbproc->hostfileinfo->host_columns[i]->terminator);
				free(dbproc->hostfileinfo->host_columns[i]);
			}
			free(dbproc->hostfileinfo->host_columns);
		}
	}

	for (i = 0; i < DBNUMOPTIONS; i++) {
		dbstring_free(&(dbproc->dbopts[i].param));
	}
	free(dbproc->dbopts);

	dbstring_free(&(dbproc->dboptcmd));

	for (i=0; i < MAXBINDTYPES; i++) {
		if (dbproc->nullreps[i].bindval != default_null_representations[i].bindval)
			free((BYTE*)dbproc->nullreps[i].bindval);
	}

	dbfreebuf(dbproc);
	free(dbproc);

	return;
}

/**
 * \ingroup dblib_core
 * \brief Close server connections and free all related structures.  
 * 
 * \sa dbclose(), dbinit(), dbopen().
 * \todo breaks if ctlib/dblib used in same process.
 */
void
dbexit()
{
	TDSSOCKET *tds;
	DBPROCESS *dbproc;
	int i, list_size;
	int count = 1;

	tdsdump_log(TDS_DBG_FUNC, "dbexit(void)\n");

	TDS_MUTEX_LOCK(&dblib_mutex);

	if (--g_dblib_ctx.ref_count != 0) {
		TDS_MUTEX_UNLOCK(&dblib_mutex);
		return;
	}

	list_size = g_dblib_ctx.connection_list_size;

	for (i = 0; i < list_size; i++) {
		tds = g_dblib_ctx.connection_list[i];
		g_dblib_ctx.connection_list[i] = NULL;
		if (tds) {
			++count;
			dbproc = (DBPROCESS *) tds->parent;
			tds_free_socket(tds);
			if (dbproc) {
				/* avoid locking in dbclose */
				dbproc->tds_socket = NULL;
				dbclose(dbproc);
			}
		}
	}
	if (g_dblib_ctx.connection_list) {
		TDS_ZERO_FREE(g_dblib_ctx.connection_list);
		g_dblib_ctx.connection_list_size = 0;
	}