From nobody Tue Feb 10 10:20:45 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 758C733E35F; Thu, 29 Jan 2026 16:29:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769704193; cv=none; b=dGCnqDC3iPZqeQPygn3K8PNpucWEWDDzb59VmPkoHF2SqezUEMiycclxOL6PXlfkjNXcriFru7XcodOYNU+SANmHCGMpzRWCAvYpW6eo8qTN5s1jzZutYuhoAB6SivUiMFT94DqbaD8xOaJm2saIRyiBwm0jLG7ePY3WdOdReOI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769704193; c=relaxed/simple; bh=Zr207pLpoOl8Efcuhmt4eGa2fB+p37mmTKkFlqtp/zU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=PXR9RiuN2Dmlh3o2xwOwVYjLs41i+G4KqcwaMwgu3N2pEiFbiWwfyvbghw7IcQS8T9MCDe2yTLmmnD/dpNUYOkbqD0jHag+d4fPgWtDgrfuo4nPr/gUOWuWyvRDt+zW/q4ZXY/tG9CdsYVfCMl9mPvU1W/ieXe0J6H9nGNqVneE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VYxHln/q; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VYxHln/q" Received: by smtp.kernel.org (Postfix) with ESMTPS id 4AF85C2BCAF; Thu, 29 Jan 2026 16:29:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769704193; bh=Zr207pLpoOl8Efcuhmt4eGa2fB+p37mmTKkFlqtp/zU=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=VYxHln/qtIR4/i9Q2Ak31wt5cXmbejvPU7WH3f8erLZsNfgQ43Y06vC81xKDygx6D gNKkKuWJqPLKPVNoagIgAeNJoYW3Uc3HJ0+NL54OdOSiUhnX6QfnQmzxHusAod0TEE dJUo6nSjqAjvaBHajS3f6OfyOAtreVnw5oWhvv+dqfE7edgD+LQ0iEEhistacSQ+Xc ZXZIlkL99N4j7dlpzJKitNvzOO2iP+FcamUTfngLcVBKPzke4+GNHiinPF+A8OubqH fwZM1Rp6ZbxpJU+kXdBmLQU8KuCn9GAqvBrgAWj5oVxBx0zTItlebPZS+tE4S0bqvk sr+OCbB//obrA== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4313FD6B08E; Thu, 29 Jan 2026 16:29:53 +0000 (UTC) From: Oliver Hartkopp via B4 Relay Date: Thu, 29 Jan 2026 17:29:09 +0100 Subject: [PATCH net-next v5 3/6] can: move ifindex to CAN skb extensions Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260129-can_skb_ext-v5-3-21252fdc8900@hartkopp.net> References: <20260129-can_skb_ext-v5-0-21252fdc8900@hartkopp.net> In-Reply-To: <20260129-can_skb_ext-v5-0-21252fdc8900@hartkopp.net> To: Marc Kleine-Budde , Vincent Mailhol , Oliver Hartkopp , Robin van der Gracht , Oleksij Rempel , kernel@pengutronix.de, "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman Cc: linux-can@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org X-Mailer: b4 0.15-dev-47773 X-Developer-Signature: v=1; a=ed25519-sha256; t=1769704191; l=7268; i=socketcan@hartkopp.net; s=20260128; h=from:subject:message-id; bh=bcCoI+Uop6YGtSYl6caeeERcJlCjQpj1nFnUHuTQg+c=; b=dd+Fe9rCzU65uFyO/yW8CRz4KmANSUFopcsH+Lrhe3scMWR5rVv59k8IJY+gqYld3jl4q+eVI lb0Z6kC5rcEBf4jyeLQ6nka0yHY5TbtTPExejRZNuUwPSuD7cGkXcEC X-Developer-Key: i=socketcan@hartkopp.net; a=ed25519; pk=/gU/7/wBqak3kTsTeFbCCqUi9dnh+1i6ITEkfPj/BvU= X-Endpoint-Received: by B4 Relay for socketcan@hartkopp.net/20260128 with auth_id=620 X-Original-From: Oliver Hartkopp Reply-To: socketcan@hartkopp.net From: Oliver Hartkopp When routing CAN frames over different CAN interfaces the interface index skb->iif is overwritten with every single hop. To prevent sending a CAN frame back to its originating (first) incoming CAN interface another ifindex variable is needed, which was stored in can_skb_priv::ifindex. Move the can_skb_priv::ifindex content to can_skb_ext::can_iif. Signed-off-by: Marc Kleine-Budde Signed-off-by: Oliver Hartkopp --- drivers/net/can/dev/skb.c | 9 ++++----- net/can/bcm.c | 4 ++-- net/can/gw.c | 2 +- net/can/isotp.c | 6 +++--- net/can/j1939/socket.c | 2 +- net/can/j1939/transport.c | 4 ++-- net/can/raw.c | 2 +- 7 files changed, 14 insertions(+), 15 deletions(-) diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c index c572745565f6..470255fe7367 100644 --- a/drivers/net/can/dev/skb.c +++ b/drivers/net/can/dev/skb.c @@ -221,11 +221,11 @@ struct sk_buff *alloc_can_skb(struct net_device *dev,= struct can_frame **cf) goto out_error_cc; } =20 skb->protocol =3D htons(ETH_P_CAN); init_can_skb_reserve(skb); - can_skb_prv(skb)->ifindex =3D dev->ifindex; + csx->can_iif =3D dev->ifindex; =20 *cf =3D skb_put_zero(skb, sizeof(struct can_frame)); =20 return skb; =20 @@ -253,11 +253,11 @@ struct sk_buff *alloc_canfd_skb(struct net_device *de= v, goto out_error_fd; } =20 skb->protocol =3D htons(ETH_P_CANFD); init_can_skb_reserve(skb); - can_skb_prv(skb)->ifindex =3D dev->ifindex; + csx->can_iif =3D dev->ifindex; =20 *cfd =3D skb_put_zero(skb, sizeof(struct canfd_frame)); =20 /* set CAN FD flag by default */ (*cfd)->flags =3D CANFD_FDF; @@ -292,11 +292,11 @@ struct sk_buff *alloc_canxl_skb(struct net_device *de= v, goto out_error_xl; } =20 skb->protocol =3D htons(ETH_P_CANXL); init_can_skb_reserve(skb); - can_skb_prv(skb)->ifindex =3D dev->ifindex; + csx->can_iif =3D dev->ifindex; =20 *cxl =3D skb_put_zero(skb, CANXL_HDR_SIZE + data_len); =20 /* set CAN XL flag and length information by default */ (*cxl)->flags =3D CANXL_XLF; @@ -342,12 +342,11 @@ static bool can_skb_headroom_valid(struct net_device = *dev, struct sk_buff *skb) csx =3D can_skb_ext_add(skb); if (!csx) return false; } =20 - can_skb_prv(skb)->ifindex =3D dev->ifindex; - + csx->can_iif =3D dev->ifindex; skb->ip_summed =3D CHECKSUM_UNNECESSARY; =20 /* perform proper loopback on capable devices */ if (dev->flags & IFF_ECHO) skb->pkt_type =3D PACKET_LOOPBACK; diff --git a/net/can/bcm.c b/net/can/bcm.c index 38452069dea8..f102d17e8619 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -321,11 +321,11 @@ static void bcm_can_tx(struct bcm_op *op) kfree_skb(skb); goto out; } =20 can_skb_reserve(skb); - can_skb_prv(skb)->ifindex =3D dev->ifindex; + csx->can_iif =3D dev->ifindex; =20 skb_put_data(skb, cf, op->cfsiz); =20 /* send with loopback */ skb->dev =3D dev; @@ -1355,11 +1355,11 @@ static int bcm_tx_send(struct msghdr *msg, int ifin= dex, struct sock *sk, if (!dev) { kfree_skb(skb); return -ENODEV; } =20 - can_skb_prv(skb)->ifindex =3D dev->ifindex; + csx->can_iif =3D dev->ifindex; skb->dev =3D dev; can_skb_set_owner(skb, sk); err =3D can_send(skb, 1); /* send with loopback */ dev_put(dev); =20 diff --git a/net/can/gw.c b/net/can/gw.c index 66df208f52a0..6f158abd61aa 100644 --- a/net/can/gw.c +++ b/net/can/gw.c @@ -503,11 +503,11 @@ static void can_can_gw_rcv(struct sk_buff *skb, void = *data) return; } =20 /* is sending the skb back to the incoming interface not allowed? */ if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) && - can_skb_prv(skb)->ifindex =3D=3D gwj->dst.dev->ifindex) + csx->can_iif =3D=3D gwj->dst.dev->ifindex) return; =20 /* clone the given skb, which has not been done in can_rcv() * * When there is at least one modification function activated, diff --git a/net/can/isotp.c b/net/can/isotp.c index 94103fe654ff..4a6ce6836b24 100644 --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -235,11 +235,11 @@ static int isotp_send_fc(struct sock *sk, int ae, u8 = flowstatus) kfree_skb(nskb); return 1; } =20 can_skb_reserve(nskb); - can_skb_prv(nskb)->ifindex =3D dev->ifindex; + csx->can_iif =3D dev->ifindex; =20 nskb->dev =3D dev; can_skb_set_owner(nskb, sk); ncf =3D (struct canfd_frame *)nskb->data; skb_put_zero(nskb, so->ll.mtu); @@ -792,11 +792,11 @@ static void isotp_send_cframe(struct isotp_sock *so) netdev_put(dev, NULL); return; } =20 can_skb_reserve(skb); - can_skb_prv(skb)->ifindex =3D dev->ifindex; + csx->can_iif =3D dev->ifindex; =20 cf =3D (struct canfd_frame *)skb->data; skb_put_zero(skb, so->ll.mtu); =20 /* create consecutive frame */ @@ -1028,11 +1028,11 @@ static int isotp_sendmsg(struct socket *sock, struc= t msghdr *msg, size_t size) netdev_put(dev, NULL); goto err_out_drop; } =20 can_skb_reserve(skb); - can_skb_prv(skb)->ifindex =3D dev->ifindex; + csx->can_iif =3D dev->ifindex; =20 so->tx.len =3D size; so->tx.idx =3D 0; =20 cf =3D (struct canfd_frame *)skb->data; diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c index fc28a7677369..f03bae79354e 100644 --- a/net/can/j1939/socket.c +++ b/net/can/j1939/socket.c @@ -902,11 +902,11 @@ static struct sk_buff *j1939_sk_alloc_skb(struct net_= device *ndev, kfree_skb(skb); goto failure; } =20 can_skb_reserve(skb); - can_skb_prv(skb)->ifindex =3D ndev->ifindex; + csx->can_iif =3D ndev->ifindex; skb_reserve(skb, offsetof(struct can_frame, data)); =20 ret =3D memcpy_from_msg(skb_put(skb, size), msg, size); if (ret < 0) goto free_skb; diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c index 0514f3504e39..96e02ad4a726 100644 --- a/net/can/j1939/transport.c +++ b/net/can/j1939/transport.c @@ -606,11 +606,11 @@ sk_buff *j1939_tp_tx_dat_new(struct j1939_priv *priv, return ERR_PTR(-ENOMEM); } =20 skb->dev =3D priv->ndev; can_skb_reserve(skb); - can_skb_prv(skb)->ifindex =3D priv->ndev->ifindex; + csx->can_iif =3D priv->ndev->ifindex; /* reserve CAN header */ skb_reserve(skb, offsetof(struct can_frame, data)); =20 /* skb->cb must be large enough to hold a j1939_sk_buff_cb structure */ BUILD_BUG_ON(sizeof(skb->cb) < sizeof(*re_skcb)); @@ -1547,11 +1547,11 @@ j1939_session *j1939_session_fresh_new(struct j1939= _priv *priv, return NULL; } =20 skb->dev =3D priv->ndev; can_skb_reserve(skb); - can_skb_prv(skb)->ifindex =3D priv->ndev->ifindex; + csx->can_iif =3D priv->ndev->ifindex; skcb =3D j1939_skb_to_cb(skb); memcpy(skcb, rel_skcb, sizeof(*skcb)); =20 session =3D j1939_session_new(priv, skb, size); if (!session) { diff --git a/net/can/raw.c b/net/can/raw.c index 03438e9bc535..7c89962ec913 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -963,11 +963,11 @@ static int raw_sendmsg(struct socket *sock, struct ms= ghdr *msg, size_t size) kfree_skb(skb); goto put_dev; } =20 can_skb_reserve(skb); - can_skb_prv(skb)->ifindex =3D dev->ifindex; + csx->can_iif =3D dev->ifindex; =20 /* fill the skb before testing for valid CAN frames */ err =3D memcpy_from_msg(skb_put(skb, size), msg, size); if (err < 0) goto free_skb; --=20 2.51.0