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/*
* Copyright (c) 2013 Todd C. Miller <millert@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/wait.h>
#include <err.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <util.h>
#define BUF_SIZE 1024
/*
* Exercise a bug in ptcwrite() when we hit the TTYHOG limit if
* the tty is in raw mode.
*/
static void sigalrm(int signo)
{
/* just return */
return;
}
int
main(int argc, char *argv[])
{
struct sigaction sa;
unsigned char buf[BUF_SIZE];
int mfd, sfd, status;
struct termios term;
size_t i, nwritten = 0, nread= 0;
ssize_t n;
/*
* Open pty and set slave to raw mode.
*/
if (openpty(&mfd, &sfd, NULL, NULL, NULL) == -1)
err(1, "openpty");
if (tcgetattr(sfd, &term) == -1)
err(1, "tcgetattr");
cfmakeraw(&term);
if (tcsetattr(sfd, TCSAFLUSH, &term) == -1)
err(1, "tcsetattr");
switch (fork()) {
case -1:
err(1, "fork");
case 0:
/* prevent a hang if the bug is present */
memset(&sa, 0, sizeof(sa));
sa.sa_handler = sigalrm;
sigemptyset(&sa.sa_mask);
sigaction(SIGALRM, &sa, NULL);
alarm(5);
/* child, read data from slave */
do {
n = read(sfd, buf + nread, sizeof(buf) - nread);
if (n == -1) {
if (errno == EINTR)
errx(1, "timed out @ %zd", nread);
err(1, "read @ %zd", nread);
}
nread += n;
} while (nread != sizeof(buf));
for (i = 0; i < sizeof(buf); i++) {
if (buf[i] != (i & 0xff)) {
errx(1, "buffer corrupted at %zd "
"(got %u, expected %zd)", i,
buf[i], (i & 0xff));
}
}
printf("all data received\n");
exit(0);
default:
/* parent, write data to master */
for (i = 0; i < sizeof(buf); i++)
buf[i] = (i & 0xff);
do {
n = write(mfd, buf + nwritten, sizeof(buf) - nwritten);
if (n == -1)
err(1, "write @ %zd", nwritten);
nwritten += n;
} while (nwritten != sizeof(buf));
wait(&status);
exit(WIFEXITED(status) ? WEXITSTATUS(status) : WTERMSIG(status) + 128);
}
}
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