view loadtools/ttypassthru.c @ 964:a96cb97b66a2

ringtools/imy: fix duplicate definition of tdma_durations[] The bug was reported by Vadim Yanitskiy <fixeria@osmocom.org>, although the present fix is slightly different from the contributed patch: because main.c doesn't need this tdma_durations[] array at all, let's simply remove the reference to this array from main.c rather than turn it into an extern. I no longer remember my original thought flow that resulted (by mistake) in tdma_durations[] being multiply defined in main.c and durations.c. My intent might have been to define all globals in main.c and have the reference in durations.c be an extern - and I missed that extern - but without clear memory, I have no certainty. In any case, having this data array defined in the same module that fills it (durations.c) is sensible, so let's make it the new way.
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 31 Aug 2023 19:38:18 +0000
parents e7502631a0f9
children
line wrap: on
line source

/*
 * This module implements the pass-thru operation mode, in which
 * the Unix host tty is cross-connected directly to the target
 * running some code we have just loaded.
 */

#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#include <termios.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <strings.h>

extern int errno;

extern int target_fd;

static struct termios saved_termios, my_termios;

static void
safe_output(buf, cc)
	u_char *buf;
{
	int i, c;

	for (i = 0; i < cc; i++) {
		c = buf[i];
		if (c == '\r' || c == '\n' || c == '\t' || c == '\b') {
			putchar(c);
			continue;
		}
		if (c & 0x80) {
			putchar('M');
			putchar('-');
			c &= 0x7F;
		}
		if (c < 0x20) {
			putchar('^');
			putchar(c + '@');
		} else if (c == 0x7F) {
			putchar('^');
			putchar('?');
		} else
			putchar(c);
	}
	fflush(stdout);
}

static void
loop()
{
	char buf[BUFSIZ];
	fd_set fds, fds1;
	register int i, cc, max;

	FD_ZERO(&fds);
	FD_SET(0, &fds);
	FD_SET(target_fd, &fds);
	max = target_fd + 1;
	for (;;) {
		bcopy(&fds, &fds1, sizeof(fd_set));
		i = select(max, &fds1, NULL, NULL, NULL);
		if (i < 0) {
			if (errno == EINTR)
				continue;
			tcsetattr(0, TCSAFLUSH, &saved_termios);
			perror("select");
			exit(1);
		}
		if (FD_ISSET(0, &fds1)) {
			cc = read(0, buf, sizeof buf);
			if (cc <= 0)
				return;
			if (cc == 1 && buf[0] == 0x1C)
				return;
			write(target_fd, buf, cc);
		}
		if (FD_ISSET(target_fd, &fds1)) {
			cc = read(target_fd, buf, sizeof buf);
			if (cc <= 0) {
				tcsetattr(0, TCSAFLUSH, &saved_termios);
				fprintf(stderr, "EOF/error on target tty\n");
				exit(1);
			}
			safe_output(buf, cc);
		}
	}
}

tty_passthru()
{
	static int zero = 0;

	ioctl(target_fd, FIONBIO, &zero);

	tcgetattr(0, &saved_termios);
	bcopy(&saved_termios, &my_termios, sizeof(struct termios));
	cfmakeraw(&my_termios);
	my_termios.c_cc[VMIN] = 1;
	my_termios.c_cc[VTIME] = 0;
	tcsetattr(0, TCSAFLUSH, &my_termios);

	printf("Entering tty pass-thru; type ^\\ to exit\r\n\n");
	loop();
	tcsetattr(0, TCSAFLUSH, &saved_termios);
	return 0;
}