can: remove private CAN skb headroom infrastructure

This patch removes struct can_skb_priv which was stored at skb->head and
the can_skb_reserve() helper which was used to shift skb->head.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20260201-can_skb_ext-v8-5-3635d790fe8b@hartkopp.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
index 408ee49abce145f49c7837ff30809bc3e42f8ab5..95fcdc1026f808656551c0253faafafd1018f48c 100644 (file)
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c
@@ -206,16 +206,10 @@ void can_free_echo_skb(struct net_device *dev, unsigned int idx,
 EXPORT_SYMBOL_GPL(can_free_echo_skb);
 
 /* fill common values for CAN sk_buffs */
-static void init_can_skb_reserve(struct sk_buff *skb)
+static void init_can_skb(struct sk_buff *skb)
 {
        skb->pkt_type = PACKET_BROADCAST;
        skb->ip_summed = CHECKSUM_UNNECESSARY;
-
-       skb_reset_mac_header(skb);
-       skb_reset_network_header(skb);
-       skb_reset_transport_header(skb);
-
-       can_skb_reserve(skb);
 }
 
 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
@@ -223,8 +217,7 @@ struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
        struct sk_buff *skb;
        struct can_skb_ext *csx;
 
-       skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
-                              sizeof(struct can_frame));
+       skb = netdev_alloc_skb(dev, sizeof(struct can_frame));
        if (unlikely(!skb))
                goto out_error_cc;
 
@@ -235,7 +228,7 @@ 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);
+       init_can_skb(skb);
        csx->can_iif = dev->ifindex;
 
        *cf = skb_put_zero(skb, sizeof(struct can_frame));
@@ -255,8 +248,7 @@ struct sk_buff *alloc_canfd_skb(struct net_device *dev,
        struct sk_buff *skb;
        struct can_skb_ext *csx;
 
-       skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
-                              sizeof(struct canfd_frame));
+       skb = netdev_alloc_skb(dev, sizeof(struct canfd_frame));
        if (unlikely(!skb))
                goto out_error_fd;
 
@@ -267,7 +259,7 @@ struct sk_buff *alloc_canfd_skb(struct net_device *dev,
        }
 
        skb->protocol = htons(ETH_P_CANFD);
-       init_can_skb_reserve(skb);
+       init_can_skb(skb);
        csx->can_iif = dev->ifindex;
 
        *cfd = skb_put_zero(skb, sizeof(struct canfd_frame));
@@ -294,8 +286,7 @@ struct sk_buff *alloc_canxl_skb(struct net_device *dev,
        if (data_len < CANXL_MIN_DLEN || data_len > CANXL_MAX_DLEN)
                goto out_error_xl;
 
-       skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
-                              CANXL_HDR_SIZE + data_len);
+       skb = netdev_alloc_skb(dev, CANXL_HDR_SIZE + data_len);
        if (unlikely(!skb))
                goto out_error_xl;
 
@@ -306,7 +297,7 @@ struct sk_buff *alloc_canxl_skb(struct net_device *dev,
        }
 
        skb->protocol = htons(ETH_P_CANXL);
-       init_can_skb_reserve(skb);
+       init_can_skb(skb);
        csx->can_iif = dev->ifindex;
 
        *cxl = skb_put_zero(skb, CANXL_HDR_SIZE + data_len);
@@ -340,14 +331,10 @@ struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
 EXPORT_SYMBOL_GPL(alloc_can_err_skb);
 
 /* Check for outgoing skbs that have not been created by the CAN subsystem */
-static bool can_skb_headroom_valid(struct net_device *dev, struct sk_buff *skb)
+static bool can_skb_init_valid(struct net_device *dev, struct sk_buff *skb)
 {
        struct can_skb_ext *csx = can_skb_ext_find(skb);
 
-       /* af_packet creates a headroom of HH_DATA_MOD bytes which is fine */
-       if (WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct can_skb_priv)))
-               return false;
-
        /* af_packet does not apply CAN skb specific settings */
        if (skb->ip_summed == CHECKSUM_NONE || !csx) {
                /* init CAN skb content */
@@ -405,7 +392,7 @@ bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb)
                goto inval_skb;
        }
 
-       if (!can_skb_headroom_valid(dev, skb))
+       if (!can_skb_init_valid(dev, skb))
                goto inval_skb;
 
        return false;

diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
index 68c0f24e69149707e38d657e821d6cbe129f7d1d..a70a0296707115c71e2f228d434cf4d76ffa9c06 100644 (file)
--- a/include/linux/can/skb.h
+++ b/include/linux/can/skb.h
@@ -38,37 +38,6 @@ struct sk_buff *alloc_can_err_skb(struct net_device *dev,
                                  struct can_frame **cf);
 bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb);
 
-/*
- * The struct can_skb_priv is used to transport additional information along
- * with the stored struct can(fd)_frame that can not be contained in existing
- * struct sk_buff elements.
- * N.B. that this information must not be modified in cloned CAN sk_buffs.
- * To modify the CAN frame content or the struct can_skb_priv content
- * skb_copy() needs to be used instead of skb_clone().
- */
-
-/**
- * struct can_skb_priv - private additional data inside CAN sk_buffs
- * @ifindex:   ifindex of the first interface the CAN frame appeared on
- * @frame_len: length of CAN frame in data link layer
- * @cf:                align to the following CAN frame at skb->data
- */
-struct can_skb_priv {
-       int ifindex;
-       unsigned int frame_len;
-       struct can_frame cf[];
-};
-
-static inline struct can_skb_priv *can_skb_prv(struct sk_buff *skb)
-{
-       return (struct can_skb_priv *)(skb->head);
-}
-
-static inline void can_skb_reserve(struct sk_buff *skb)
-{
-       skb_reserve(skb, sizeof(struct can_skb_priv));
-}
-
 static inline struct can_skb_ext *can_skb_ext_add(struct sk_buff *skb)
 {
        struct can_skb_ext *csx = skb_ext_add(skb, SKB_EXT_CAN);

diff --git a/net/can/bcm.c b/net/can/bcm.c
index f102d17e86190b7a46f806870991136c0b416b0d..b7324e9c955b7f03a8f032676bbd89aa8e06bded 100644 (file)
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -312,7 +312,7 @@ static void bcm_can_tx(struct bcm_op *op)
                return;
        }
 
-       skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
+       skb = alloc_skb(op->cfsiz, gfp_any());
        if (!skb)
                goto out;
 
@@ -322,7 +322,6 @@ static void bcm_can_tx(struct bcm_op *op)
                goto out;
        }
 
-       can_skb_reserve(skb);
        csx->can_iif = dev->ifindex;
 
        skb_put_data(skb, cf, op->cfsiz);
@@ -1333,7 +1332,7 @@ static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
        if (!ifindex)
                return -ENODEV;
 
-       skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
+       skb = alloc_skb(cfsiz, GFP_KERNEL);
        if (!skb)
                return -ENOMEM;
 
@@ -1343,8 +1342,6 @@ static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
                return -ENOMEM;
        }
 
-       can_skb_reserve(skb);
-
        err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
        if (err < 0) {
                kfree_skb(skb);

diff --git a/net/can/isotp.c b/net/can/isotp.c
index 164c4fbf3e2310a64631eb296e3b68b9c7d70ac3..da3b72e7afccb731734b525ce2136f469ad889aa 100644 (file)
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -220,7 +220,7 @@ static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
        struct isotp_sock *so = isotp_sk(sk);
        int can_send_ret;
 
-       nskb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), gfp_any());
+       nskb = alloc_skb(so->ll.mtu, gfp_any());
        if (!nskb)
                return 1;
 
@@ -236,9 +236,7 @@ static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
                return 1;
        }
 
-       can_skb_reserve(nskb);
        csx->can_iif = dev->ifindex;
-
        nskb->dev = dev;
        can_skb_set_owner(nskb, sk);
        ncf = (struct canfd_frame *)nskb->data;
@@ -780,7 +778,7 @@ static void isotp_send_cframe(struct isotp_sock *so)
        if (!dev)
                return;
 
-       skb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), GFP_ATOMIC);
+       skb = alloc_skb(so->ll.mtu, GFP_ATOMIC);
        if (!skb) {
                dev_put(dev);
                return;
@@ -793,7 +791,6 @@ static void isotp_send_cframe(struct isotp_sock *so)
                return;
        }
 
-       can_skb_reserve(skb);
        csx->can_iif = dev->ifindex;
 
        cf = (struct canfd_frame *)skb->data;
@@ -1015,8 +1012,8 @@ static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
                goto err_out_drop;
        }
 
-       skb = sock_alloc_send_skb(sk, so->ll.mtu + sizeof(struct can_skb_priv),
-                                 msg->msg_flags & MSG_DONTWAIT, &err);
+       skb = sock_alloc_send_skb(sk, so->ll.mtu, msg->msg_flags & MSG_DONTWAIT,
+                                 &err);
        if (!skb) {
                dev_put(dev);
                goto err_out_drop;
@@ -1030,7 +1027,6 @@ static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
                goto err_out_drop;
        }
 
-       can_skb_reserve(skb);
        csx->can_iif = dev->ifindex;
 
        so->tx.len = size;

diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c
index cc698a6dc3635d8f7c9682040271295eec196912..0502b030d23851652be252f1342861332ce97367 100644 (file)
--- a/net/can/j1939/socket.c
+++ b/net/can/j1939/socket.c
@@ -891,8 +891,7 @@ static struct sk_buff *j1939_sk_alloc_skb(struct net_device *ndev,
        skb = sock_alloc_send_skb(sk,
                                  size +
                                  sizeof(struct can_frame) -
-                                 sizeof(((struct can_frame *)NULL)->data) +
-                                 sizeof(struct can_skb_priv),
+                                 sizeof(((struct can_frame *)NULL)->data),
                                  msg->msg_flags & MSG_DONTWAIT, &ret);
        if (!skb)
                goto failure;
@@ -904,7 +903,6 @@ static struct sk_buff *j1939_sk_alloc_skb(struct net_device *ndev,
                goto failure;
        }
 
-       can_skb_reserve(skb);
        csx->can_iif = ndev->ifindex;
        skb_reserve(skb, offsetof(struct can_frame, data));
 

diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index 3456ef481799a2a25ec282629d0d1fa6a1d0686e..2cbe94fc487a320719aa951d9c860f45f15d693d 100644 (file)
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -595,8 +595,7 @@ sk_buff *j1939_tp_tx_dat_new(struct j1939_priv *priv,
        struct can_skb_ext *csx;
        struct j1939_sk_buff_cb *skcb;
 
-       skb = alloc_skb(sizeof(struct can_frame) + sizeof(struct can_skb_priv),
-                       GFP_ATOMIC);
+       skb = alloc_skb(sizeof(struct can_frame), GFP_ATOMIC);
        if (unlikely(!skb))
                return ERR_PTR(-ENOMEM);
 
@@ -607,7 +606,6 @@ sk_buff *j1939_tp_tx_dat_new(struct j1939_priv *priv,
        }
 
        skb->dev = priv->ndev;
-       can_skb_reserve(skb);
        csx->can_iif = priv->ndev->ifindex;
        /* reserve CAN header */
        skb_reserve(skb, offsetof(struct can_frame, data));
@@ -1548,7 +1546,7 @@ j1939_session *j1939_session_fresh_new(struct j1939_priv *priv,
        struct j1939_sk_buff_cb *skcb;
        struct j1939_session *session;
 
-       skb = alloc_skb(size + sizeof(struct can_skb_priv), GFP_ATOMIC);
+       skb = alloc_skb(size, GFP_ATOMIC);
        if (unlikely(!skb))
                return NULL;
 
@@ -1559,7 +1557,6 @@ j1939_session *j1939_session_fresh_new(struct j1939_priv *priv,
        }
 
        skb->dev = priv->ndev;
-       can_skb_reserve(skb);
        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 022154b0f6cc610cdc35af1b18c0fa8777775ee3..eee244ffc31ecc0e1cc1aae29cd1d13a4e6b54ca 100644 (file)
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -953,8 +953,8 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
                goto put_dev;
        }
 
-       skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
-                                 msg->msg_flags & MSG_DONTWAIT, &err);
+       skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT,
+                                 &err);
        if (!skb)
                goto put_dev;
 
@@ -965,7 +965,6 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
                goto put_dev;
        }
 
-       can_skb_reserve(skb);
        csx->can_iif = dev->ifindex;
 
        /* fill the skb before testing for valid CAN frames */