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[80.116.90.174]) by smtp.gmail.com with ESMTPSA id z22-20020a17090655d600b006f3ef214e2csm5087043ejp.146.2022.06.14.05.28.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Jun 2022 05:28:29 -0700 (PDT) From: Dario Binacchi To: linux-kernel@vger.kernel.org Cc: Amarula patchwork , Oliver Hartkopp , michael@amarulasolutions.com, Dario Binacchi , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Marc Kleine-Budde , Paolo Abeni , Wolfgang Grandegger , linux-can@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH v4 03/12] can: slcan: use the alloc_can_skb() helper Date: Tue, 14 Jun 2022 14:28:12 +0200 Message-Id: <20220614122821.3646071-4-dario.binacchi@amarulasolutions.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220614122821.3646071-1-dario.binacchi@amarulasolutions.com> References: <20220614122821.3646071-1-dario.binacchi@amarulasolutions.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org It is used successfully by most (if not all) CAN device drivers. It allows to remove replicated code. Signed-off-by: Dario Binacchi --- (no changes since v3) Changes in v3: - Increment the error counter in case of decoding failure. Changes in v2: - Put the data into the allocated skb directly instead of first filling the "cf" on the stack and then doing a memcpy(). drivers/net/can/slcan.c | 70 +++++++++++++++++++---------------------- 1 file changed, 33 insertions(+), 37 deletions(-) diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index 6162a9c21672..c39580b142e0 100644 --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -54,6 +54,7 @@ #include #include #include +#include #include #include @@ -143,85 +144,80 @@ static struct net_device **slcan_devs; static void slc_bump(struct slcan *sl) { struct sk_buff *skb; - struct can_frame cf; + struct can_frame *cf; int i, tmp; u32 tmpid; char *cmd = sl->rbuff; - memset(&cf, 0, sizeof(cf)); + skb = alloc_can_skb(sl->dev, &cf); + if (unlikely(!skb)) { + sl->dev->stats.rx_dropped++; + return; + } switch (*cmd) { case 'r': - cf.can_id = CAN_RTR_FLAG; + cf->can_id = CAN_RTR_FLAG; fallthrough; case 't': /* store dlc ASCII value and terminate SFF CAN ID string */ - cf.len = sl->rbuff[SLC_CMD_LEN + SLC_SFF_ID_LEN]; + cf->len = sl->rbuff[SLC_CMD_LEN + SLC_SFF_ID_LEN]; sl->rbuff[SLC_CMD_LEN + SLC_SFF_ID_LEN] = 0; /* point to payload data behind the dlc */ cmd += SLC_CMD_LEN + SLC_SFF_ID_LEN + 1; break; case 'R': - cf.can_id = CAN_RTR_FLAG; + cf->can_id = CAN_RTR_FLAG; fallthrough; case 'T': - cf.can_id |= CAN_EFF_FLAG; + cf->can_id |= CAN_EFF_FLAG; /* store dlc ASCII value and terminate EFF CAN ID string */ - cf.len = sl->rbuff[SLC_CMD_LEN + SLC_EFF_ID_LEN]; + cf->len = sl->rbuff[SLC_CMD_LEN + SLC_EFF_ID_LEN]; sl->rbuff[SLC_CMD_LEN + SLC_EFF_ID_LEN] = 0; /* point to payload data behind the dlc */ cmd += SLC_CMD_LEN + SLC_EFF_ID_LEN + 1; break; default: - return; + goto decode_failed; } if (kstrtou32(sl->rbuff + SLC_CMD_LEN, 16, &tmpid)) - return; + goto decode_failed; - cf.can_id |= tmpid; + cf->can_id |= tmpid; /* get len from sanitized ASCII value */ - if (cf.len >= '0' && cf.len < '9') - cf.len -= '0'; + if (cf->len >= '0' && cf->len < '9') + cf->len -= '0'; else - return; + goto decode_failed; /* RTR frames may have a dlc > 0 but they never have any data bytes */ - if (!(cf.can_id & CAN_RTR_FLAG)) { - for (i = 0; i < cf.len; i++) { + if (!(cf->can_id & CAN_RTR_FLAG)) { + for (i = 0; i < cf->len; i++) { tmp = hex_to_bin(*cmd++); if (tmp < 0) - return; - cf.data[i] = (tmp << 4); + goto decode_failed; + + cf->data[i] = (tmp << 4); tmp = hex_to_bin(*cmd++); if (tmp < 0) - return; - cf.data[i] |= tmp; + goto decode_failed; + + cf->data[i] |= tmp; } } - skb = dev_alloc_skb(sizeof(struct can_frame) + - sizeof(struct can_skb_priv)); - if (!skb) - return; - - skb->dev = sl->dev; - skb->protocol = htons(ETH_P_CAN); - skb->pkt_type = PACKET_BROADCAST; - skb->ip_summed = CHECKSUM_UNNECESSARY; - - can_skb_reserve(skb); - can_skb_prv(skb)->ifindex = sl->dev->ifindex; - can_skb_prv(skb)->skbcnt = 0; - - skb_put_data(skb, &cf, sizeof(struct can_frame)); - sl->dev->stats.rx_packets++; - if (!(cf.can_id & CAN_RTR_FLAG)) - sl->dev->stats.rx_bytes += cf.len; + if (!(cf->can_id & CAN_RTR_FLAG)) + sl->dev->stats.rx_bytes += cf->len; netif_rx(skb); + return; + +decode_failed: + sl->dev->stats.rx_errors++; + dev_kfree_skb(skb); } /* parse tty input stream */