Replace open coded checks for sk_buffs containing Classical CAN and
CAN FD frame structures as a preparation for CAN XL support.
With the added length check the unintended processing of CAN XL frames
having the CANXL_XLF bit set can be suppressed even when the skb->len
fits to non CAN XL frames.
The CAN_RAW socket needs a rework to use these helpers. Therefore the
use of these helpers is postponed to the CAN_RAW CAN XL integration.
The J1939 protocol gets a check for Classical CAN frames too.
Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
---
drivers/net/can/dev/skb.c | 18 +++++++-------
include/linux/can/skb.h | 12 +++++++++-
net/can/af_can.c | 50 ++++++++-------------------------------
net/can/bcm.c | 9 +++++--
net/can/gw.c | 4 ++--
net/can/isotp.c | 2 +-
net/can/j1939/main.c | 4 ++++
7 files changed, 45 insertions(+), 54 deletions(-)
diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
index 8bb62dd864c8..45313b90005c 100644
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c
@@ -291,22 +291,24 @@ static bool can_skb_headroom_valid(struct net_device *dev, struct sk_buff *skb)
}
/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb)
{
- const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
struct can_priv *priv = netdev_priv(dev);
- if (skb->protocol == htons(ETH_P_CAN)) {
- if (unlikely(skb->len != CAN_MTU ||
- cfd->len > CAN_MAX_DLEN))
+ switch (ntohs(skb->protocol)) {
+ case ETH_P_CAN:
+ if (!can_is_can_skb(skb))
goto inval_skb;
- } else if (skb->protocol == htons(ETH_P_CANFD)) {
- if (unlikely(skb->len != CANFD_MTU ||
- cfd->len > CANFD_MAX_DLEN))
+ break;
+
+ case ETH_P_CANFD:
+ if (!can_is_canfd_skb(skb))
goto inval_skb;
- } else {
+ break;
+
+ default:
goto inval_skb;
}
if (!can_skb_headroom_valid(dev, skb)) {
goto inval_skb;
diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
index 182749e858b3..27ebfc28510f 100644
--- a/include/linux/can/skb.h
+++ b/include/linux/can/skb.h
@@ -95,12 +95,22 @@ static inline struct sk_buff *can_create_echo_skb(struct sk_buff *skb)
can_skb_set_owner(nskb, skb->sk);
consume_skb(skb);
return nskb;
}
+static inline bool can_is_can_skb(const struct sk_buff *skb)
+{
+ struct can_frame *cf = (struct can_frame *)skb->data;
+
+ /* the CAN specific type of skb is identified by its data length */
+ return (skb->len == CAN_MTU && cf->len <= CAN_MAX_DLEN);
+}
+
static inline bool can_is_canfd_skb(const struct sk_buff *skb)
{
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
/* the CAN specific type of skb is identified by its data length */
- return skb->len == CANFD_MTU;
+ return (skb->len == CANFD_MTU && cfd->len <= CANFD_MAX_DLEN);
}
#endif /* !_CAN_SKB_H */
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 1fb49d51b25d..afa6c2151bc4 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -197,31 +197,23 @@ static int can_create(struct net *net, struct socket *sock, int protocol,
* -EINVAL when the skb->data does not contain a valid CAN frame
*/
int can_send(struct sk_buff *skb, int loop)
{
struct sk_buff *newskb = NULL;
- struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
struct can_pkg_stats *pkg_stats = dev_net(skb->dev)->can.pkg_stats;
int err = -EINVAL;
- if (skb->len == CAN_MTU) {
+ if (can_is_can_skb(skb)) {
skb->protocol = htons(ETH_P_CAN);
- if (unlikely(cfd->len > CAN_MAX_DLEN))
- goto inval_skb;
- } else if (skb->len == CANFD_MTU) {
+ } else if (can_is_canfd_skb(skb)) {
skb->protocol = htons(ETH_P_CANFD);
- if (unlikely(cfd->len > CANFD_MAX_DLEN))
- goto inval_skb;
} else {
goto inval_skb;
}
- /* Make sure the CAN frame can pass the selected CAN netdevice.
- * As structs can_frame and canfd_frame are similar, we can provide
- * CAN FD frames to legacy CAN drivers as long as the length is <= 8
- */
- if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) {
+ /* Make sure the CAN frame can pass the selected CAN netdevice. */
+ if (unlikely(skb->len > skb->dev->mtu)) {
err = -EMSGSIZE;
goto inval_skb;
}
if (unlikely(skb->dev->type != ARPHRD_CAN)) {
@@ -676,57 +668,35 @@ static void can_receive(struct sk_buff *skb, struct net_device *dev)
}
static int can_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
- struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
-
- if (unlikely(dev->type != ARPHRD_CAN || skb->len != CAN_MTU)) {
+ if (unlikely(dev->type != ARPHRD_CAN || (!can_is_can_skb(skb)))) {
pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d\n",
dev->type, skb->len);
- goto free_skb;
- }
- /* This check is made separately since cfd->len would be uninitialized if skb->len = 0. */
- if (unlikely(cfd->len > CAN_MAX_DLEN)) {
- pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d, datalen %d\n",
- dev->type, skb->len, cfd->len);
- goto free_skb;
+ kfree_skb(skb);
+ return NET_RX_DROP;
}
can_receive(skb, dev);
return NET_RX_SUCCESS;
-
-free_skb:
- kfree_skb(skb);
- return NET_RX_DROP;
}
static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
- struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
-
- if (unlikely(dev->type != ARPHRD_CAN || skb->len != CANFD_MTU)) {
+ if (unlikely(dev->type != ARPHRD_CAN || (!can_is_canfd_skb(skb)))) {
pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d\n",
dev->type, skb->len);
- goto free_skb;
- }
- /* This check is made separately since cfd->len would be uninitialized if skb->len = 0. */
- if (unlikely(cfd->len > CANFD_MAX_DLEN)) {
- pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d, datalen %d\n",
- dev->type, skb->len, cfd->len);
- goto free_skb;
+ kfree_skb(skb);
+ return NET_RX_DROP;
}
can_receive(skb, dev);
return NET_RX_SUCCESS;
-
-free_skb:
- kfree_skb(skb);
- return NET_RX_DROP;
}
/* af_can protocol functions */
/**
diff --git a/net/can/bcm.c b/net/can/bcm.c
index e60161bec850..e5d179ba6f7d 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -646,12 +646,17 @@ static void bcm_rx_handler(struct sk_buff *skb, void *data)
if (op->can_id != rxframe->can_id)
return;
/* make sure to handle the correct frame type (CAN / CAN FD) */
- if (skb->len != op->cfsiz)
- return;
+ if (op->flags & CAN_FD_FRAME) {
+ if (!can_is_canfd_skb(skb))
+ return;
+ } else {
+ if (!can_is_can_skb(skb))
+ return;
+ }
/* disable timeout */
hrtimer_cancel(&op->timer);
/* save rx timestamp */
diff --git a/net/can/gw.c b/net/can/gw.c
index 1ea4cc527db3..23a3d89cad81 100644
--- a/net/can/gw.c
+++ b/net/can/gw.c
@@ -461,14 +461,14 @@ static void can_can_gw_rcv(struct sk_buff *skb, void *data)
struct sk_buff *nskb;
int modidx = 0;
/* process strictly Classic CAN or CAN FD frames */
if (gwj->flags & CGW_FLAGS_CAN_FD) {
- if (skb->len != CANFD_MTU)
+ if (!can_is_canfd_skb(skb))
return;
} else {
- if (skb->len != CAN_MTU)
+ if (!can_is_can_skb(skb))
return;
}
/* Do not handle CAN frames routed more than 'max_hops' times.
* In general we should never catch this delimiter which is intended
diff --git a/net/can/isotp.c b/net/can/isotp.c
index 43a27d19cdac..a9d1357f8489 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -667,11 +667,11 @@ static void isotp_rcv(struct sk_buff *skb, void *data)
sf_dl = cf->data[ae] & 0x0F;
if (cf->len <= CAN_MAX_DLEN) {
isotp_rcv_sf(sk, cf, SF_PCI_SZ4 + ae, skb, sf_dl);
} else {
- if (skb->len == CANFD_MTU) {
+ if (can_is_canfd_skb(skb)) {
/* We have a CAN FD frame and CAN_DL is greater than 8:
* Only frames with the SF_DL == 0 ESC value are valid.
*
* If so take care of the increased SF PCI size
* (SF_PCI_SZ8) to point to the message content behind
diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
index 8452b0fbb78c..ce09626038a1 100644
--- a/net/can/j1939/main.c
+++ b/net/can/j1939/main.c
@@ -40,10 +40,14 @@ static void j1939_can_recv(struct sk_buff *iskb, void *data)
struct j1939_priv *priv = data;
struct sk_buff *skb;
struct j1939_sk_buff_cb *skcb, *iskcb;
struct can_frame *cf;
+ /* make sure we only get Classical CAN frames */
+ if (!can_is_can_skb(iskb))
+ return;
+
/* create a copy of the skb
* j1939 only delivers the real data bytes,
* the header goes into sockaddr.
* j1939 may not touch the incoming skb in such way
*/
--
2.30.2
