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path: root/drivers/net/can/slcan.c
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Diffstat (limited to 'drivers/net/can/slcan.c')
-rw-r--r--drivers/net/can/slcan.c139
1 files changed, 90 insertions, 49 deletions
diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c
index 874188ba06f..25377e547f9 100644
--- a/drivers/net/can/slcan.c
+++ b/drivers/net/can/slcan.c
@@ -76,6 +76,10 @@ MODULE_PARM_DESC(maxdev, "Maximum number of slcan interfaces");
/* maximum rx buffer len: extended CAN frame with timestamp */
#define SLC_MTU (sizeof("T1111222281122334455667788EA5F\r")+1)
+#define SLC_CMD_LEN 1
+#define SLC_SFF_ID_LEN 3
+#define SLC_EFF_ID_LEN 8
+
struct slcan {
int magic;
@@ -142,47 +146,63 @@ static void slc_bump(struct slcan *sl)
{
struct sk_buff *skb;
struct can_frame cf;
- int i, dlc_pos, tmp;
- unsigned long ultmp;
- char cmd = sl->rbuff[0];
-
- if ((cmd != 't') && (cmd != 'T') && (cmd != 'r') && (cmd != 'R'))
+ int i, tmp;
+ u32 tmpid;
+ char *cmd = sl->rbuff;
+
+ cf.can_id = 0;
+
+ switch (*cmd) {
+ case 'r':
+ cf.can_id = CAN_RTR_FLAG;
+ /* fallthrough */
+ case 't':
+ /* store dlc ASCII value and terminate SFF CAN ID string */
+ cf.can_dlc = sl->rbuff[SLC_CMD_LEN + SLC_SFF_ID_LEN];
+ sl->rbuff[SLC_CMD_LEN + SLC_SFF_ID_LEN] = 0;
+ /* point to payload data behind the dlc */
+ cmd += SLC_CMD_LEN + SLC_SFF_ID_LEN + 1;
+ break;
+ case 'R':
+ cf.can_id = CAN_RTR_FLAG;
+ /* fallthrough */
+ case 'T':
+ cf.can_id |= CAN_EFF_FLAG;
+ /* store dlc ASCII value and terminate EFF CAN ID string */
+ cf.can_dlc = sl->rbuff[SLC_CMD_LEN + SLC_EFF_ID_LEN];
+ sl->rbuff[SLC_CMD_LEN + SLC_EFF_ID_LEN] = 0;
+ /* point to payload data behind the dlc */
+ cmd += SLC_CMD_LEN + SLC_EFF_ID_LEN + 1;
+ break;
+ default:
return;
+ }
- if (cmd & 0x20) /* tiny chars 'r' 't' => standard frame format */
- dlc_pos = 4; /* dlc position tiiid */
- else
- dlc_pos = 9; /* dlc position Tiiiiiiiid */
-
- if (!((sl->rbuff[dlc_pos] >= '0') && (sl->rbuff[dlc_pos] < '9')))
+ if (kstrtou32(sl->rbuff + SLC_CMD_LEN, 16, &tmpid))
return;
- cf.can_dlc = sl->rbuff[dlc_pos] - '0'; /* get can_dlc from ASCII val */
+ cf.can_id |= tmpid;
- sl->rbuff[dlc_pos] = 0; /* terminate can_id string */
-
- if (kstrtoul(sl->rbuff+1, 16, &ultmp))
+ /* get can_dlc from sanitized ASCII value */
+ if (cf.can_dlc >= '0' && cf.can_dlc < '9')
+ cf.can_dlc -= '0';
+ else
return;
- cf.can_id = ultmp;
-
- if (!(cmd & 0x20)) /* NO tiny chars => extended frame format */
- cf.can_id |= CAN_EFF_FLAG;
-
- if ((cmd | 0x20) == 'r') /* RTR frame */
- cf.can_id |= CAN_RTR_FLAG;
-
*(u64 *) (&cf.data) = 0; /* clear payload */
- for (i = 0, dlc_pos++; i < cf.can_dlc; i++) {
- tmp = hex_to_bin(sl->rbuff[dlc_pos++]);
- if (tmp < 0)
- return;
- cf.data[i] = (tmp << 4);
- tmp = hex_to_bin(sl->rbuff[dlc_pos++]);
- if (tmp < 0)
- return;
- cf.data[i] |= tmp;
+ /* RTR frames may have a dlc > 0 but they never have any data bytes */
+ if (!(cf.can_id & CAN_RTR_FLAG)) {
+ for (i = 0; i < cf.can_dlc; i++) {
+ tmp = hex_to_bin(*cmd++);
+ if (tmp < 0)
+ return;
+ cf.data[i] = (tmp << 4);
+ tmp = hex_to_bin(*cmd++);
+ if (tmp < 0)
+ return;
+ cf.data[i] |= tmp;
+ }
}
skb = dev_alloc_skb(sizeof(struct can_frame) +
@@ -209,7 +229,6 @@ static void slc_bump(struct slcan *sl)
/* parse tty input stream */
static void slcan_unesc(struct slcan *sl, unsigned char s)
{
-
if ((s == '\r') || (s == '\a')) { /* CR or BEL ends the pdu */
if (!test_and_clear_bit(SLF_ERROR, &sl->flags) &&
(sl->rcount > 4)) {
@@ -236,27 +255,46 @@ static void slcan_unesc(struct slcan *sl, unsigned char s)
/* Encapsulate one can_frame and stuff into a TTY queue. */
static void slc_encaps(struct slcan *sl, struct can_frame *cf)
{
- int actual, idx, i;
- char cmd;
+ int actual, i;
+ unsigned char *pos;
+ unsigned char *endpos;
+ canid_t id = cf->can_id;
+
+ pos = sl->xbuff;
if (cf->can_id & CAN_RTR_FLAG)
- cmd = 'R'; /* becomes 'r' in standard frame format */
+ *pos = 'R'; /* becomes 'r' in standard frame format (SFF) */
else
- cmd = 'T'; /* becomes 't' in standard frame format */
+ *pos = 'T'; /* becomes 't' in standard frame format (SSF) */
- if (cf->can_id & CAN_EFF_FLAG)
- sprintf(sl->xbuff, "%c%08X%d", cmd,
- cf->can_id & CAN_EFF_MASK, cf->can_dlc);
- else
- sprintf(sl->xbuff, "%c%03X%d", cmd | 0x20,
- cf->can_id & CAN_SFF_MASK, cf->can_dlc);
+ /* determine number of chars for the CAN-identifier */
+ if (cf->can_id & CAN_EFF_FLAG) {
+ id &= CAN_EFF_MASK;
+ endpos = pos + SLC_EFF_ID_LEN;
+ } else {
+ *pos |= 0x20; /* convert R/T to lower case for SFF */
+ id &= CAN_SFF_MASK;
+ endpos = pos + SLC_SFF_ID_LEN;
+ }
- idx = strlen(sl->xbuff);
+ /* build 3 (SFF) or 8 (EFF) digit CAN identifier */
+ pos++;
+ while (endpos >= pos) {
+ *endpos-- = hex_asc_upper[id & 0xf];
+ id >>= 4;
+ }
+
+ pos += (cf->can_id & CAN_EFF_FLAG) ? SLC_EFF_ID_LEN : SLC_SFF_ID_LEN;
- for (i = 0; i < cf->can_dlc; i++)
- sprintf(&sl->xbuff[idx + 2*i], "%02X", cf->data[i]);
+ *pos++ = cf->can_dlc + '0';
+
+ /* RTR frames may have a dlc > 0 but they never have any data bytes */
+ if (!(cf->can_id & CAN_RTR_FLAG)) {
+ for (i = 0; i < cf->can_dlc; i++)
+ pos = hex_byte_pack_upper(pos, cf->data[i]);
+ }
- strcat(sl->xbuff, "\r"); /* add terminating character */
+ *pos++ = '\r';
/* Order of next two lines is *very* important.
* When we are sending a little amount of data,
@@ -267,8 +305,8 @@ static void slc_encaps(struct slcan *sl, struct can_frame *cf)
* 14 Oct 1994 Dmitry Gorodchanin.
*/
set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
- actual = sl->tty->ops->write(sl->tty, sl->xbuff, strlen(sl->xbuff));
- sl->xleft = strlen(sl->xbuff) - actual;
+ actual = sl->tty->ops->write(sl->tty, sl->xbuff, pos - sl->xbuff);
+ sl->xleft = (pos - sl->xbuff) - actual;
sl->xhead = sl->xbuff + actual;
sl->dev->stats.tx_bytes += cf->can_dlc;
}
@@ -286,11 +324,13 @@ static void slcan_write_wakeup(struct tty_struct *tty)
if (!sl || sl->magic != SLCAN_MAGIC || !netif_running(sl->dev))
return;
+ spin_lock(&sl->lock);
if (sl->xleft <= 0) {
/* Now serial buffer is almost free & we can start
* transmission of another packet */
sl->dev->stats.tx_packets++;
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+ spin_unlock(&sl->lock);
netif_wake_queue(sl->dev);
return;
}
@@ -298,6 +338,7 @@ static void slcan_write_wakeup(struct tty_struct *tty)
actual = tty->ops->write(tty, sl->xhead, sl->xleft);
sl->xleft -= actual;
sl->xhead += actual;
+ spin_unlock(&sl->lock);
}
/* Send a can_frame to a TTY queue. */
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-19 07:17:10 +0000