From patchwork Fri Nov 20 13:33:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Kleine-Budde X-Patchwork-Id: 11920317 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4770C5519F for ; Fri, 20 Nov 2020 13:34:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8297522272 for ; Fri, 20 Nov 2020 13:34:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728373AbgKTNeB (ORCPT ); Fri, 20 Nov 2020 08:34:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728135AbgKTNda (ORCPT ); Fri, 20 Nov 2020 08:33:30 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36D57C061A4E for ; Fri, 20 Nov 2020 05:33:28 -0800 (PST) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=blackshift.org) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1kg6XW-0006Fn-8K; Fri, 20 Nov 2020 14:33:26 +0100 From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org, kernel@pengutronix.de, Oliver Hartkopp , Marc Kleine-Budde Subject: [net-next 11/25] can: gw: support modification of Classical CAN DLCs Date: Fri, 20 Nov 2020 14:33:04 +0100 Message-Id: <20201120133318.3428231-12-mkl@pengutronix.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201120133318.3428231-1-mkl@pengutronix.de> References: <20201120133318.3428231-1-mkl@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: netdev@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Oliver Hartkopp Add support for data length code modifications for Classical CAN. The netlink configuration interface always allowed to pass any value that fits into a byte, therefore only the modification process had to be extended to handle the raw DLC represenation of Classical CAN frames. When a DLC value from 0 .. F is provided for Classical CAN frame modifications the 'len' value is modified as-is with the exception that potentially existing 9 .. F DLC values in the len8_dlc element are moved to the 'len' element for the modification operation by mod_retrieve_ccdlc(). After the modification the Classical CAN frame DLC information is brought back into the correct format by mod_store_ccdlc() which is filling 'len' and 'len8_dlc' accordingly. Signed-off-by: Oliver Hartkopp Link: https://lore.kernel.org/r/20201119084921.2621-1-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde --- include/uapi/linux/can/gw.h | 4 +- net/can/gw.c | 78 +++++++++++++++++++++++++++++++++---- 2 files changed, 72 insertions(+), 10 deletions(-) diff --git a/include/uapi/linux/can/gw.h b/include/uapi/linux/can/gw.h index c2190bbe21d8..e4f0957554f3 100644 --- a/include/uapi/linux/can/gw.h +++ b/include/uapi/linux/can/gw.h @@ -98,8 +98,8 @@ enum { /* CAN frame elements that are affected by curr. 3 CAN frame modifications */ #define CGW_MOD_ID 0x01 -#define CGW_MOD_DLC 0x02 /* contains the data length in bytes */ -#define CGW_MOD_LEN CGW_MOD_DLC /* CAN FD length representation */ +#define CGW_MOD_DLC 0x02 /* Classical CAN data length code */ +#define CGW_MOD_LEN CGW_MOD_DLC /* CAN FD (plain) data length */ #define CGW_MOD_DATA 0x04 #define CGW_MOD_FLAGS 0x08 /* CAN FD flags */ diff --git a/net/can/gw.c b/net/can/gw.c index de5e8859ec9b..8598d9da0e5f 100644 --- a/net/can/gw.c +++ b/net/can/gw.c @@ -199,6 +199,68 @@ static void mod_set_fddata(struct canfd_frame *cf, struct cf_mod *mod) memcpy(cf->data, mod->modframe.set.data, CANFD_MAX_DLEN); } +/* retrieve valid CC DLC value and store it into 'len' */ +static void mod_retrieve_ccdlc(struct canfd_frame *cf) +{ + struct can_frame *ccf = (struct can_frame *)cf; + + /* len8_dlc is only valid if len == CAN_MAX_DLEN */ + if (ccf->len != CAN_MAX_DLEN) + return; + + /* do we have a valid len8_dlc value from 9 .. 15 ? */ + if (ccf->len8_dlc > CAN_MAX_DLEN && ccf->len8_dlc <= CAN_MAX_RAW_DLC) + ccf->len = ccf->len8_dlc; +} + +/* convert valid CC DLC value in 'len' into struct can_frame elements */ +static void mod_store_ccdlc(struct canfd_frame *cf) +{ + struct can_frame *ccf = (struct can_frame *)cf; + + /* clear potential leftovers */ + ccf->len8_dlc = 0; + + /* plain data length 0 .. 8 - that was easy */ + if (ccf->len <= CAN_MAX_DLEN) + return; + + /* potentially broken values are catched in can_can_gw_rcv() */ + if (ccf->len > CAN_MAX_RAW_DLC) + return; + + /* we have a valid dlc value from 9 .. 15 in ccf->len */ + ccf->len8_dlc = ccf->len; + ccf->len = CAN_MAX_DLEN; +} + +static void mod_and_ccdlc(struct canfd_frame *cf, struct cf_mod *mod) +{ + mod_retrieve_ccdlc(cf); + mod_and_len(cf, mod); + mod_store_ccdlc(cf); +} + +static void mod_or_ccdlc(struct canfd_frame *cf, struct cf_mod *mod) +{ + mod_retrieve_ccdlc(cf); + mod_or_len(cf, mod); + mod_store_ccdlc(cf); +} + +static void mod_xor_ccdlc(struct canfd_frame *cf, struct cf_mod *mod) +{ + mod_retrieve_ccdlc(cf); + mod_xor_len(cf, mod); + mod_store_ccdlc(cf); +} + +static void mod_set_ccdlc(struct canfd_frame *cf, struct cf_mod *mod) +{ + mod_set_len(cf, mod); + mod_store_ccdlc(cf); +} + static void canframecpy(struct canfd_frame *dst, struct can_frame *src) { /* Copy the struct members separately to ensure that no uninitialized @@ -842,8 +904,8 @@ static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod, if (mb.modtype & CGW_MOD_ID) mod->modfunc[modidx++] = mod_and_id; - if (mb.modtype & CGW_MOD_LEN) - mod->modfunc[modidx++] = mod_and_len; + if (mb.modtype & CGW_MOD_DLC) + mod->modfunc[modidx++] = mod_and_ccdlc; if (mb.modtype & CGW_MOD_DATA) mod->modfunc[modidx++] = mod_and_data; @@ -858,8 +920,8 @@ static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod, if (mb.modtype & CGW_MOD_ID) mod->modfunc[modidx++] = mod_or_id; - if (mb.modtype & CGW_MOD_LEN) - mod->modfunc[modidx++] = mod_or_len; + if (mb.modtype & CGW_MOD_DLC) + mod->modfunc[modidx++] = mod_or_ccdlc; if (mb.modtype & CGW_MOD_DATA) mod->modfunc[modidx++] = mod_or_data; @@ -874,8 +936,8 @@ static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod, if (mb.modtype & CGW_MOD_ID) mod->modfunc[modidx++] = mod_xor_id; - if (mb.modtype & CGW_MOD_LEN) - mod->modfunc[modidx++] = mod_xor_len; + if (mb.modtype & CGW_MOD_DLC) + mod->modfunc[modidx++] = mod_xor_ccdlc; if (mb.modtype & CGW_MOD_DATA) mod->modfunc[modidx++] = mod_xor_data; @@ -890,8 +952,8 @@ static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod, if (mb.modtype & CGW_MOD_ID) mod->modfunc[modidx++] = mod_set_id; - if (mb.modtype & CGW_MOD_LEN) - mod->modfunc[modidx++] = mod_set_len; + if (mb.modtype & CGW_MOD_DLC) + mod->modfunc[modidx++] = mod_set_ccdlc; if (mb.modtype & CGW_MOD_DATA) mod->modfunc[modidx++] = mod_set_data;