[PATCH can-next v2 3/6] can: move ifindex to CAN skb extensions
From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: 2026-01-28 09:29:30
Also in:
linux-can, lkml
Subsystem:
can network drivers, can network layer, can-j1939 network layer, the rest · Maintainers:
Marc Kleine-Budde, Vincent Mailhol, Oliver Hartkopp, Robin van der Gracht, Oleksij Rempel, Linus Torvalds
From: Oliver Hartkopp <socketcan@hartkopp.net> 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: Oliver Hartkopp <socketcan@hartkopp.net> --- 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@@ -223,7 +223,7 @@ struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf) skb->protocol = htons(ETH_P_CAN); init_can_skb_reserve(skb); - can_skb_prv(skb)->ifindex = dev->ifindex; + csx->can_iif = dev->ifindex; *cf = skb_put_zero(skb, sizeof(struct can_frame));
@@ -255,7 +255,7 @@ struct sk_buff *alloc_canfd_skb(struct net_device *dev, skb->protocol = htons(ETH_P_CANFD); init_can_skb_reserve(skb); - can_skb_prv(skb)->ifindex = dev->ifindex; + csx->can_iif = dev->ifindex; *cfd = skb_put_zero(skb, sizeof(struct canfd_frame));
@@ -294,7 +294,7 @@ struct sk_buff *alloc_canxl_skb(struct net_device *dev, skb->protocol = htons(ETH_P_CANXL); init_can_skb_reserve(skb); - can_skb_prv(skb)->ifindex = dev->ifindex; + csx->can_iif = dev->ifindex; *cxl = skb_put_zero(skb, CANXL_HDR_SIZE + data_len);
@@ -344,8 +344,7 @@ static bool can_skb_headroom_valid(struct net_device *dev, struct sk_buff *skb) return false; } - can_skb_prv(skb)->ifindex = dev->ifindex; - + csx->can_iif = dev->ifindex; skb->ip_summed = CHECKSUM_UNNECESSARY; /* perform proper loopback on capable devices */
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@@ -323,7 +323,7 @@ static void bcm_can_tx(struct bcm_op *op) } can_skb_reserve(skb); - can_skb_prv(skb)->ifindex = dev->ifindex; + csx->can_iif = dev->ifindex; skb_put_data(skb, cf, op->cfsiz);
@@ -1357,7 +1357,7 @@ static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk, return -ENODEV; } - can_skb_prv(skb)->ifindex = dev->ifindex; + csx->can_iif = dev->ifindex; skb->dev = dev; can_skb_set_owner(skb, sk); err = can_send(skb, 1); /* send with loopback */
diff --git a/net/can/gw.c b/net/can/gw.c
index 8894ab5d2087..ad89a1913b34 100644
--- a/net/can/gw.c
+++ b/net/can/gw.c@@ -505,7 +505,7 @@ static void can_can_gw_rcv(struct sk_buff *skb, void *data) /* 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 == gwj->dst.dev->ifindex) + csx->can_iif == gwj->dst.dev->ifindex) return; /* clone the given skb, which has not been done in can_rcv()
diff --git a/net/can/isotp.c b/net/can/isotp.c
index c4fb8afde165..01ceb3febbb7 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c@@ -237,7 +237,7 @@ static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus) } can_skb_reserve(nskb); - can_skb_prv(nskb)->ifindex = dev->ifindex; + csx->can_iif = dev->ifindex; nskb->dev = dev; can_skb_set_owner(nskb, sk);
@@ -794,7 +794,7 @@ static void isotp_send_cframe(struct isotp_sock *so) } can_skb_reserve(skb); - can_skb_prv(skb)->ifindex = dev->ifindex; + csx->can_iif = dev->ifindex; cf = (struct canfd_frame *)skb->data; skb_put_zero(skb, so->ll.mtu);
@@ -1030,7 +1030,7 @@ static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) } can_skb_reserve(skb); - can_skb_prv(skb)->ifindex = dev->ifindex; + csx->can_iif = dev->ifindex; so->tx.len = size; so->tx.idx = 0;
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@@ -904,7 +904,7 @@ static struct sk_buff *j1939_sk_alloc_skb(struct net_device *ndev, } can_skb_reserve(skb); - can_skb_prv(skb)->ifindex = ndev->ifindex; + csx->can_iif = ndev->ifindex; skb_reserve(skb, offsetof(struct can_frame, data)); ret = memcpy_from_msg(skb_put(skb, size), msg, size);
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@@ -608,7 +608,7 @@ sk_buff *j1939_tp_tx_dat_new(struct j1939_priv *priv, skb->dev = priv->ndev; can_skb_reserve(skb); - can_skb_prv(skb)->ifindex = priv->ndev->ifindex; + csx->can_iif = priv->ndev->ifindex; /* reserve CAN header */ skb_reserve(skb, offsetof(struct can_frame, data));
@@ -1549,7 +1549,7 @@ j1939_session *j1939_session_fresh_new(struct j1939_priv *priv, skb->dev = priv->ndev; can_skb_reserve(skb); - can_skb_prv(skb)->ifindex = priv->ndev->ifindex; + csx->can_iif = priv->ndev->ifindex; skcb = j1939_skb_to_cb(skb); memcpy(skcb, rel_skcb, sizeof(*skcb));
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@@ -965,7 +965,7 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) } can_skb_reserve(skb); - can_skb_prv(skb)->ifindex = dev->ifindex; + csx->can_iif = dev->ifindex; /* fill the skb before testing for valid CAN frames */ err = memcpy_from_msg(skb_put(skb, size), msg, size);
--
2.51.0