[PATCH 1/1] can: skb: add and set local_origin flag

From: Oleksij Rempel
Date: Wed May 11 2022 - 08:19:53 EST


Add new can_skb_priv::local_origin flag to be able detect egress
packages even if they was sent directly from kernel and not assigned to
some socket.

Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Cc: Devid Antonio Filoni <devid.filoni@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/net/can/dev/skb.c | 3 +++
include/linux/can/skb.h | 1 +
net/can/raw.c | 2 +-
3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
index 61660248c69e..3e2357fb387e 100644
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c
@@ -63,6 +63,7 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,

/* save frame_len to reuse it when transmission is completed */
can_skb_prv(skb)->frame_len = frame_len;
+ can_skb_prv(skb)->local_origin = true;

skb_tx_timestamp(skb);

@@ -200,6 +201,7 @@ struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
can_skb_reserve(skb);
can_skb_prv(skb)->ifindex = dev->ifindex;
can_skb_prv(skb)->skbcnt = 0;
+ can_skb_prv(skb)->local_origin = false;

*cf = skb_put_zero(skb, sizeof(struct can_frame));

@@ -231,6 +233,7 @@ struct sk_buff *alloc_canfd_skb(struct net_device *dev,
can_skb_reserve(skb);
can_skb_prv(skb)->ifindex = dev->ifindex;
can_skb_prv(skb)->skbcnt = 0;
+ can_skb_prv(skb)->local_origin = false;

*cfd = skb_put_zero(skb, sizeof(struct canfd_frame));

diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
index fdb22b00674a..1b8a8cf2b13b 100644
--- a/include/linux/can/skb.h
+++ b/include/linux/can/skb.h
@@ -52,6 +52,7 @@ struct can_skb_priv {
int ifindex;
int skbcnt;
unsigned int frame_len;
+ bool local_origin;
struct can_frame cf[];
};

diff --git a/net/can/raw.c b/net/can/raw.c
index b7dbb57557f3..df2d9334b395 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -173,7 +173,7 @@ static void raw_rcv(struct sk_buff *oskb, void *data)
/* add CAN specific message flags for raw_recvmsg() */
pflags = raw_flags(skb);
*pflags = 0;
- if (oskb->sk)
+ if (can_skb_prv(skb)->local_origin)
*pflags |= MSG_DONTROUTE;
if (oskb->sk == sk)
*pflags |= MSG_CONFIRM;
--
2.30.2