diff options
Diffstat (limited to 'drivers/net/can')
-rw-r--r-- | drivers/net/can/slcan.c | 136 |
1 files changed, 87 insertions, 49 deletions
diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index d571e2e..25377e5 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; + } + + /* 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; - idx = strlen(sl->xbuff); + *pos++ = cf->can_dlc + '0'; - for (i = 0; i < cf->can_dlc; i++) - sprintf(&sl->xbuff[idx + 2*i], "%02X", cf->data[i]); + /* 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; } |