-/*
- * $Id$
- */
-
/*
* slcanpty.c - creates a pty for applications using the slcan ASCII protocol
* and converts the ASCII data to a CAN network interface (and vice versa)
*
*/
+/* To get ptsname grantpt and unlockpt definitions from stdlib.h */
+#define _GNU_SOURCE
+
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* maximum rx buffer len: extended CAN frame with timestamp */
#define SLC_MTU (sizeof("T1111222281122334455667788EA5F\r")+1)
+#define DEVICE_NAME_PTMX "/dev/ptmx"
#define DEBUG
/* 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 *is_open, int *tstamp)
{
int nbytes;
char cmd;
- char buf[200];
+ 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");
- nbytes = read(pty, &buf, sizeof(buf)-1);
- 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) {
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;
ptr = 1;
goto rx_out;
}
+ /* check for 'v'ersion command */
+ if (cmd == 'v') {
+ sprintf(replybuf, "v1014\r");
+ tmp = strlen(replybuf);
+ ptr = 1;
+ goto rx_out;
+ }
/* check for serial 'N'umber command */
if (cmd == 'N') {
ptr--;
}
- nbytes = write(socket, &frame, sizeof(frame));
- if (nbytes != sizeof(frame)) {
+ tmp = write(socket, &frame, sizeof(frame));
+ if (tmp != sizeof(frame)) {
perror("write socket");
return 1;
}
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;
+}
int main(int argc, char **argv)
{
int s; /* can raw socket */
struct sockaddr_can addr;
struct termios topts;
- struct ifreq ifr;
+ int select_stdin = 0;
int running = 1;
int tstamp = 0;
int is_open = 0;
fprintf(stderr, "Usage: %s <pty> <can interface>\n", argv[0]);
fprintf(stderr, "e.g. '%s /dev/ptyc0 can0' creates"
" /dev/ttyc0 for the slcan application\n", argv[0]);
+ fprintf(stderr, "e.g. for pseudo-terminal '%s %s can0' creates"
+ " /dev/pts/N\n", argv[0], DEVICE_NAME_PTMX);
fprintf(stderr, "\n");
return 1;
}
+ select_stdin = check_select_stdin();
+
/* open pty */
p = open(argv[1], O_RDWR);
if (p < 0) {
/* disable local echo which would cause double frames */
topts.c_lflag &= ~(ICANON | ECHO | ECHOE | ECHOK |
- ECHONL | ECHOPRT | ECHOKE | ICRNL);
+ ECHONL | ECHOPRT | ECHOKE);
+ topts.c_iflag &= ~(ICRNL);
+ topts.c_iflag |= INLCR;
tcsetattr(p, TCSANOW, &topts);
+ /* Support for the Unix 98 pseudo-terminal interface /dev/ptmx /dev/pts/N */
+ if (strcmp(argv[1], DEVICE_NAME_PTMX) == 0) {
+
+ char *name_pts = NULL; /* slave pseudo-terminal device name */
+
+ if (grantpt(p) < 0) {
+ perror("grantpt");
+ return 1;
+ }
+
+ if (unlockpt(p) < 0) {
+ perror("unlockpt");
+ return 1;
+ }
+
+ name_pts = ptsname(p);
+ if (name_pts == NULL) {
+ perror("ptsname");
+ return 1;
+ }
+ printf("open: %s: slave pseudo-terminal is %s\n", argv[1], name_pts);
+ }
+
/* open socket */
s = socket(PF_CAN, SOCK_RAW, CAN_RAW);
if (s < 0) {
}
addr.can_family = AF_CAN;
-
- strcpy(ifr.ifr_name, argv[2]);
- if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) {
- perror("SIOCGIFINDEX");
- return 1;
- }
- addr.can_ifindex = ifr.ifr_ifindex;
+ addr.can_ifindex = if_nametoindex(argv[2]);
/* disable reception of CAN frames until we are opened by 'O' */
setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0);
while (running) {
FD_ZERO(&rdfs);
- FD_SET(0, &rdfs);
+
+ if (select_stdin)
+ FD_SET(0, &rdfs);
+
FD_SET(p, &rdfs);
FD_SET(s, &rdfs);
projects / can-utils.git / blobdiff