if (net != &init_net)
return -EAFNOSUPPORT;
-#ifdef CONFIG_KMOD
- /* try to load protocol module, when CONFIG_KMOD is defined */
+#ifdef CONFIG_MODULES
+ /* try to load protocol module kernel is modular */
if (!proto_tab[protocol]) {
err = request_module("can-proto-%d", protocol);
* @skb: pointer to socket buffer with CAN frame in data section
* @loop: loopback for listeners on local CAN sockets (recommended default!)
*
+ * Due to the loopback this routine must not be called from hardirq context.
+ *
* Return:
* 0 on success
* -ENETDOWN when the selected interface is down
* -ENOBUFS on full driver queue (see net_xmit_errno())
* -ENOMEM when local loopback failed at calling skb_clone()
* -EPERM when trying to send on a non-CAN interface
+ * -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 can_frame *cf = (struct can_frame *)skb->data;
int err;
+ if (skb->len != sizeof(struct can_frame) || cf->can_dlc > 8) {
+ kfree_skb(skb);
+ return -EINVAL;
+ }
+
if (skb->dev->type != ARPHRD_CAN) {
kfree_skb(skb);
return -EPERM;
err = net_xmit_errno(err);
if (err) {
- if (newskb)
- kfree_skb(newskb);
+ kfree_skb(newskb);
return err;
}
if (newskb)
- netif_rx(newskb);
+ netif_rx_ni(newskb);
/* update statistics */
can_stats.tx_frames++;
return n ? d : NULL;
}
+/**
+ * find_rcv_list - determine optimal filterlist inside device filter struct
+ * @can_id: pointer to CAN identifier of a given can_filter
+ * @mask: pointer to CAN mask of a given can_filter
+ * @d: pointer to the device filter struct
+ *
+ * Description:
+ * Returns the optimal filterlist to reduce the filter handling in the
+ * receive path. This function is called by service functions that need
+ * to register or unregister a can_filter in the filter lists.
+ *
+ * A filter matches in general, when
+ *
+ * <received_can_id> & mask == can_id & mask
+ *
+ * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
+ * relevant bits for the filter.
+ *
+ * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
+ * filter for error frames (CAN_ERR_FLAG bit set in mask). For error frames
+ * there is a special filterlist and a special rx path filter handling.
+ *
+ * Return:
+ * Pointer to optimal filterlist for the given can_id/mask pair.
+ * Constistency checked mask.
+ * Reduced can_id to have a preprocessed filter compare value.
+ */
static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
struct dev_rcv_lists *d)
{
canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
- /* filter error frames */
+ /* filter for error frames in extra filterlist */
if (*mask & CAN_ERR_FLAG) {
- /* clear CAN_ERR_FLAG in list entry */
+ /* clear CAN_ERR_FLAG in filter entry */
*mask &= CAN_ERR_MASK;
return &d->rx[RX_ERR];
}
- /* ensure valid values in can_mask */
- if (*mask & CAN_EFF_FLAG)
- *mask &= (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG);
- else
- *mask &= (CAN_SFF_MASK | CAN_RTR_FLAG);
+ /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
+
+#define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
+
+ /* ensure valid values in can_mask for 'SFF only' frame filtering */
+ if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
+ *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
/* reduce condition testing at receive time */
*can_id &= *mask;
if (!(*mask))
return &d->rx[RX_ALL];
- /* use extra filterset for the subscription of exactly *ONE* can_id */
- if (*can_id & CAN_EFF_FLAG) {
- if (*mask == (CAN_EFF_MASK | CAN_EFF_FLAG)) {
- /* RFC: a use-case for hash-tables in the future? */
- return &d->rx[RX_EFF];
+ /* extra filterlists for the subscription of a single non-RTR can_id */
+ if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS)
+ && !(*can_id & CAN_RTR_FLAG)) {
+
+ if (*can_id & CAN_EFF_FLAG) {
+ if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) {
+ /* RFC: a future use-case for hash-tables? */
+ return &d->rx[RX_EFF];
+ }
+ } else {
+ if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
+ return &d->rx_sff[*can_id];
}
- } else {
- if (*mask == CAN_SFF_MASK)
- return &d->rx_sff[*can_id];
}
/* default: filter via can_id/can_mask */
* The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
* filter for error frames (CAN_ERR_FLAG bit set in mask).
*
+ * The provided pointer to the sk_buff is guaranteed to be valid as long as
+ * the callback function is running. The callback function must *not* free
+ * the given sk_buff while processing it's task. When the given sk_buff is
+ * needed after the end of the callback function it must be cloned inside
+ * the callback function with skb_clone().
+ *
* Return:
* 0 on success
* -ENOMEM on missing cache mem to create subscription entry
static inline void deliver(struct sk_buff *skb, struct receiver *r)
{
- struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);
-
- if (clone) {
- clone->sk = skb->sk;
- r->func(clone, r->data);
- r->matches++;
- }
+ r->func(skb, r->data);
+ r->matches++;
}
static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
}
}
- /* check CAN_ID specific entries */
+ /* check filterlists for single non-RTR can_ids */
+ if (can_id & CAN_RTR_FLAG)
+ return matches;
+
if (can_id & CAN_EFF_FLAG) {
hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) {
if (r->can_id == can_id) {
struct packet_type *pt, struct net_device *orig_dev)
{
struct dev_rcv_lists *d;
+ struct can_frame *cf = (struct can_frame *)skb->data;
int matches;
- if (dev->type != ARPHRD_CAN || dev_net(dev) != &init_net) {
- kfree_skb(skb);
- return 0;
- }
+ if (!net_eq(dev_net(dev), &init_net))
+ goto drop;
+
+ if (WARN_ONCE(dev->type != ARPHRD_CAN ||
+ skb->len != sizeof(struct can_frame) ||
+ cf->can_dlc > 8,
+ "PF_CAN: dropped non conform skbuf: "
+ "dev type %d, len %d, can_dlc %d\n",
+ dev->type, skb->len, cf->can_dlc))
+ goto drop;
/* update statistics */
can_stats.rx_frames++;
rcu_read_unlock();
- /* free the skbuff allocated by the netdevice driver */
- kfree_skb(skb);
+ /* consume the skbuff allocated by the netdevice driver */
+ consume_skb(skb);
if (matches > 0) {
can_stats.matches++;
can_stats.matches_delta++;
}
- return 0;
+ return NET_RX_SUCCESS;
+
+drop:
+ kfree_skb(skb);
+ return NET_RX_DROP;
}
/*
struct net_device *dev = (struct net_device *)data;
struct dev_rcv_lists *d;
- if (dev_net(dev) != &init_net)
+ if (!net_eq(dev_net(dev), &init_net))
return NOTIFY_DONE;
if (dev->type != ARPHRD_CAN)
*/
static struct packet_type can_packet __read_mostly = {
- .type = __constant_htons(ETH_P_CAN),
+ .type = cpu_to_be16(ETH_P_CAN),
.dev = NULL,
.func = can_rcv,
};
}
spin_unlock(&can_rcvlists_lock);
+ rcu_barrier(); /* Wait for completion of call_rcu()'s */
+
kmem_cache_destroy(rcv_cache);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff