+/* read data from pty, send CAN frames to CAN socket and answer commands */
+int pty2can(int pty, int socket, struct can_filter *fi,
+ int *is_open, int *tstamp)
+{
+ int nbytes;
+ char cmd;
+ static char buf[200];
+ char replybuf[10]; /* for answers to received commands */
+ int ptr;
+ struct can_frame frame;
+ int tmp, i;
+ static int rxoffset = 0; /* points to the end of an received incomplete SLCAN message */
+
+ nbytes = read(pty, &buf[rxoffset], sizeof(buf)-rxoffset-1);
+ if (nbytes <= 0) {
+ /* nbytes == 0 : no error but pty decriptor has been closed */
+ if (nbytes < 0)
+ perror("read pty");
+
+ return 1;
+ }
+
+ /* reset incomplete message offset */
+ nbytes += rxoffset;
+ rxoffset = 0;
+
+rx_restart:
+ /* remove trailing '\r' characters to be robust against some apps */
+ while (buf[0] == '\r' && nbytes > 0) {
+ for (tmp = 0; tmp < nbytes; tmp++)
+ buf[tmp] = buf[tmp+1];
+ nbytes--;
+ }
+
+ if (!nbytes)
+ return 0;
+
+ /* check if we can detect a complete SLCAN message including '\r' */
+ for (tmp = 0; tmp < nbytes; tmp++) {
+ if (buf[tmp] == '\r')
+ break;
+ }
+
+ /* no '\r' found in the message buffer? */
+ if (tmp == nbytes) {
+ /* save incomplete message */
+ rxoffset = nbytes;
+
+ /* leave here and read from pty again */
+ return 0;
+ }
+
+ cmd = buf[0];
+ buf[nbytes] = 0;
+
+#ifdef DEBUG
+ for (tmp = 0; tmp < nbytes; tmp++)
+ if (buf[tmp] == '\r')
+ putchar('@');
+ else
+ putchar(buf[tmp]);
+ printf("\n");
+#endif
+
+ /* check for filter configuration commands */
+ if (cmd == 'm' || cmd == 'M') {
+ buf[9] = 0; /* terminate filter string */
+ ptr = 9;
+#if 0
+ /* the filter is no SocketCAN filter :-( */
+
+ /* TODO: behave like a SJA1000 controller specific filter */
+
+ if (cmd == 'm') {
+ fi->can_id = strtoul(buf+1,NULL,16);
+ fi->can_id &= CAN_EFF_MASK;
+ } else {
+ fi->can_mask = strtoul(buf+1,NULL,16);
+ fi->can_mask &= CAN_EFF_MASK;
+ }
+
+ if (*is_open)
+ setsockopt(socket, SOL_CAN_RAW,
+ CAN_RAW_FILTER, fi,
+ sizeof(struct can_filter));
+#endif
+ goto rx_out_ack;
+ }
+
+
+ /* check for timestamp on/off command */
+ if (cmd == 'Z') {
+ *tstamp = buf[1] & 0x01;
+ ptr = 2;
+ goto rx_out_ack;
+ }
+
+ /* check for 'O'pen command */
+ if (cmd == 'O') {
+ setsockopt(socket, SOL_CAN_RAW,
+ CAN_RAW_FILTER, fi,
+ sizeof(struct can_filter));
+ ptr = 1;
+ *is_open = 1;
+ goto rx_out_ack;
+ }
+
+ /* check for 'C'lose command */
+ if (cmd == 'C') {
+ setsockopt(socket, SOL_CAN_RAW, CAN_RAW_FILTER,
+ NULL, 0);
+ ptr = 1;
+ *is_open = 0;
+ goto rx_out_ack;
+ }
+
+ /* check for 'V'ersion command */
+ if (cmd == 'V') {
+ sprintf(replybuf, "V1013\r");
+ tmp = strlen(replybuf);
+ ptr = 1;
+ goto rx_out;
+ }
+
+ /* check for serial 'N'umber command */
+ if (cmd == 'N') {
+ sprintf(replybuf, "N4242\r");
+ tmp = strlen(replybuf);
+ ptr = 1;
+ goto rx_out;
+ }
+
+ /* check for read status 'F'lags */
+ if (cmd == 'F') {
+ sprintf(replybuf, "F00\r");
+ tmp = strlen(replybuf);
+ ptr = 1;
+ goto rx_out;
+ }
+
+ /* correctly answer unsupported commands */
+ if (cmd == 'U') {
+ ptr = 2;
+ goto rx_out_ack;
+ }
+ if (cmd == 'S') {
+ ptr = 2;
+ goto rx_out_ack;
+ }
+ if (cmd == 's') {
+ ptr = 5;
+ goto rx_out_ack;
+ }
+ if (cmd == 'P' || cmd == 'A') {
+ ptr = 1;
+ goto rx_out_nack;
+ }
+ if (cmd == 'X') {
+ ptr = 2;
+ if (buf[1] & 0x01)
+ goto rx_out_ack;
+ else
+ goto rx_out_nack;
+ }
+
+ /* catch unknown commands */
+ if ((cmd != 't') && (cmd != 'T') &&
+ (cmd != 'r') && (cmd != 'R')) {
+ ptr = nbytes-1;
+ goto rx_out_nack;
+ }
+
+ if (cmd & 0x20) /* tiny chars 'r' 't' => SFF */
+ ptr = 4; /* dlc position tiiid */
+ else
+ ptr = 9; /* dlc position Tiiiiiiiid */
+
+ *(unsigned long long *) (&frame.data) = 0ULL; /* clear data[] */
+
+ if ((cmd | 0x20) == 'r' && buf[ptr] != '0') {
+
+ /*
+ * RTR frame without dlc information!
+ * This is against the SLCAN spec but sent
+ * by a commercial CAN tool ... so we are
+ * robust against this protocol violation.
+ */
+
+ frame.can_dlc = buf[ptr]; /* save following byte */
+
+ buf[ptr] = 0; /* terminate can_id string */
+
+ frame.can_id = strtoul(buf+1, NULL, 16);
+ frame.can_id |= CAN_RTR_FLAG;
+
+ if (!(cmd & 0x20)) /* NO tiny chars => EFF */
+ frame.can_id |= CAN_EFF_FLAG;
+
+ buf[ptr] = frame.can_dlc; /* restore following byte */
+ frame.can_dlc = 0;
+ ptr--; /* we have no dlc component in the violation case */
+
+ } else {
+
+ if (!(buf[ptr] >= '0' && buf[ptr] < '9'))
+ goto rx_out_nack;
+
+ frame.can_dlc = buf[ptr] - '0'; /* get dlc from ASCII val */
+
+ buf[ptr] = 0; /* terminate can_id string */
+
+ frame.can_id = strtoul(buf+1, NULL, 16);
+
+ if (!(cmd & 0x20)) /* NO tiny chars => EFF */
+ frame.can_id |= CAN_EFF_FLAG;
+
+ if ((cmd | 0x20) == 'r') /* RTR frame */
+ frame.can_id |= CAN_RTR_FLAG;
+
+ for (i = 0, ptr++; i < frame.can_dlc; i++) {
+
+ tmp = asc2nibble(buf[ptr++]);
+ if (tmp > 0x0F)
+ goto rx_out_nack;
+ frame.data[i] = (tmp << 4);
+ tmp = asc2nibble(buf[ptr++]);
+ if (tmp > 0x0F)
+ goto rx_out_nack;
+ frame.data[i] |= tmp;
+ }
+ /* point to last real data */
+ if (frame.can_dlc)
+ ptr--;
+ }
+
+ tmp = write(socket, &frame, sizeof(frame));
+ if (tmp != sizeof(frame)) {
+ perror("write socket");
+ return 1;
+ }
+
+rx_out_ack:
+ replybuf[0] = '\r';
+ tmp = 1;
+ goto rx_out;
+rx_out_nack:
+ replybuf[0] = '\a';
+ tmp = 1;
+rx_out:
+ tmp = write(pty, replybuf, tmp);
+ if (tmp < 0) {
+ perror("write pty replybuf");
+ return 1;
+ }
+
+ /* check if there is another command in this buffer */
+ if (nbytes > ptr+1) {
+ for (tmp = 0, ptr++; ptr+tmp < nbytes; tmp++)
+ buf[tmp] = buf[ptr+tmp];
+ nbytes = tmp;
+ goto rx_restart;
+ }
+
+ return 0;
+}
+
+/* read CAN frames from CAN interface and write it to the pty */
+int can2pty(int pty, int socket, int *tstamp)
+{
+ int nbytes;
+ char cmd;
+ char buf[SLC_MTU];
+ int ptr;
+ struct can_frame frame;
+ int i;
+
+ nbytes = read(socket, &frame, sizeof(frame));
+ if (nbytes != sizeof(frame)) {
+ perror("read socket");
+ return 1;
+ }
+
+ /* convert to slcan ASCII frame */
+ if (frame.can_id & CAN_RTR_FLAG)
+ cmd = 'R'; /* becomes 'r' in SFF format */
+ else
+ cmd = 'T'; /* becomes 't' in SFF format */
+
+ if (frame.can_id & CAN_EFF_FLAG)
+ sprintf(buf, "%c%08X%d", cmd,
+ frame.can_id & CAN_EFF_MASK,
+ frame.can_dlc);
+ else
+ sprintf(buf, "%c%03X%d", cmd | 0x20,
+ frame.can_id & CAN_SFF_MASK,
+ frame.can_dlc);
+
+ ptr = strlen(buf);
+
+ for (i = 0; i < frame.can_dlc; i++)
+ sprintf(&buf[ptr + 2*i], "%02X",
+ frame.data[i]);
+
+ if (*tstamp) {
+ struct timeval tv;
+
+ if (ioctl(socket, SIOCGSTAMP, &tv) < 0)
+ perror("SIOCGSTAMP");
+
+ sprintf(&buf[ptr + 2*frame.can_dlc], "%04lX",
+ (tv.tv_sec%60)*1000 + tv.tv_usec/1000);
+ }
+
+ strcat(buf, "\r"); /* add terminating character */
+ nbytes = write(pty, buf, strlen(buf));
+ if (nbytes < 0) {
+ perror("write pty");
+ return 1;
+ }
+ fflush(NULL);
+
+ return 0;
+}
+
+int check_select_stdin(void)
+{
+ fd_set rdfs;
+ struct timeval timeout;
+ int ret;
+
+ FD_ZERO(&rdfs);
+ FD_SET(0, &rdfs);
+ timeout.tv_sec = 0;
+ timeout.tv_usec = 0;
+
+ ret = select(1, &rdfs, NULL, NULL, &timeout);
+
+ if (ret < 0)
+ return 0; /* not selectable */
+
+ if (ret > 0 && getchar() == EOF)
+ return 0; /* EOF, eg. /dev/null */
+
+ return 1;
+}
+