tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
candev: add/update helpers for CAN FD
- update sanity checks
- add DLC to length conversion helpers
- can_dlc2len() - get data length from can_dlc with sanitized can_dlc
- can_len2dlc() - map the sanitized data length to an appropriate DLC
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
authored by
Oliver Hartkopp
and committed by
Marc Kleine-Budde
1e0625fa
e2d265d3
+58
-8
+34
-1
drivers/net/can/dev.c
+34
-1
drivers/net/can/dev.c
···
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
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+
/* CAN DLC to real data length conversion helpers */
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static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
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8, 12, 16, 20, 24, 32, 48, 64};
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/* get data length from can_dlc with sanitized can_dlc */
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u8 can_dlc2len(u8 can_dlc)
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{
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return dlc2len[can_dlc & 0x0F];
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}
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EXPORT_SYMBOL_GPL(can_dlc2len);
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static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */
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9, 9, 9, 9, /* 9 - 12 */
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10, 10, 10, 10, /* 13 - 16 */
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11, 11, 11, 11, /* 17 - 20 */
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12, 12, 12, 12, /* 21 - 24 */
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13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */
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14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */
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14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */
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15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */
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15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */
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/* map the sanitized data length to an appropriate data length code */
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u8 can_len2dlc(u8 len)
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{
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if (unlikely(len > 64))
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return 0xF;
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return len2dlc[len];
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}
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EXPORT_SYMBOL_GPL(can_len2dlc);
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#ifdef CONFIG_CAN_CALC_BITTIMING
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#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
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···
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static void can_setup(struct net_device *dev)
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{
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dev->type = ARPHRD_CAN;
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-
dev->mtu = sizeof(struct can_frame);
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dev->mtu = CAN_MTU;
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dev->hard_header_len = 0;
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dev->addr_len = 0;
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dev->tx_queue_len = 10;
+24
-7
include/linux/can/dev.h
+24
-7
include/linux/can/dev.h
···
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* To be used in the CAN netdriver receive path to ensure conformance with
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* ISO 11898-1 Chapter 8.4.2.3 (DLC field)
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*/
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#define get_can_dlc(i) (min_t(__u8, (i), 8))
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#define get_can_dlc(i) (min_t(__u8, (i), CAN_MAX_DLC))
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#define get_canfd_dlc(i) (min_t(__u8, (i), CANFD_MAX_DLC))
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/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
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static inline int can_dropped_invalid_skb(struct net_device *dev,
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struct sk_buff *skb)
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{
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-
const struct can_frame *cf = (struct can_frame *)skb->data;
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const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
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if (unlikely(skb->len != sizeof(*cf) || cf->can_dlc > 8)) {
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kfree_skb(skb);
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dev->stats.tx_dropped++;
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return 1;
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}
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if (skb->protocol == htons(ETH_P_CAN)) {
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if (unlikely(skb->len != CAN_MTU ||
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cfd->len > CAN_MAX_DLEN))
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goto inval_skb;
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} else if (skb->protocol == htons(ETH_P_CANFD)) {
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if (unlikely(skb->len != CANFD_MTU ||
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cfd->len > CANFD_MAX_DLEN))
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goto inval_skb;
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} else
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goto inval_skb;
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return 0;
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inval_skb:
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kfree_skb(skb);
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dev->stats.tx_dropped++;
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return 1;
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}
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/* get data length from can_dlc with sanitized can_dlc */
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u8 can_dlc2len(u8 can_dlc);
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/* map the sanitized data length to an appropriate data length code */
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u8 can_len2dlc(u8 len);
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struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
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void free_candev(struct net_device *dev);