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/*
* Forks a shell for each terminal and waits for them.
* This is the final thing you should be executing
* (with kernel_execve) in kernel-land once everything works.
*/
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
char *empty[] = {NULL};
const char *hi = "init: starting shell on ";
const char *sh = "/bin/sh";
const char *ttystr = "tty";
const char *home = "/";
const char *alldone = "init: no remaining processes\n";
static int open_tty(char *tty)
{
if (-1 == open(tty, O_RDONLY, 0))
{
return -1;
}
else if (-1 == open(tty, O_WRONLY, 0))
{
return -1;
}
else if (2 != dup(1))
{
return -1;
}
else
{
return 0;
}
}
static int canary = 0x12345678;
static void spawn_shell_on(char *tty)
{
if (!fork())
{
close(0);
close(1);
close(2);
if (-1 == open_tty(tty))
{
exit(1);
}
chdir(home);
printf("%s%s\n", hi, tty);
execve(sh, empty, empty);
fprintf(stderr, "exec failed!\n");
}
}
int main(int argc, char **argv, char **envp)
{
int devdir, ii;
dirent_t d;
int status;
for (ii = 0; ii < NFILES; ii++)
{
close(ii);
}
ii = ii;
if (-1 == open_tty("/dev/tty0"))
{
exit(1);
}
chdir("/dev");
devdir = open("/dev", O_RDONLY, 0);
while (getdents(devdir, &d, sizeof(d)) > 0)
{
if (0 == strncmp(d.d_name, ttystr, strlen(ttystr)))
{
spawn_shell_on(d.d_name);
}
}
close(devdir);
int pid;
while (0 <= (pid = wait(&status)))
{
if (EFAULT == status)
{
printf("process %i faulted\n", pid);
}
}
if (ECHILD != errno)
{
printf("error: wait: %s\n", strerror(errno));
return 1;
}
else
{
printf("%s", alldone);
return 0;
}
}
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