66 lines
1.1 KiB
C
66 lines
1.1 KiB
C
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/*
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* runs a proper tty on a serial port
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <syscall.h>
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int main(int argc, char * argv[]) {
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int fd_master, fd_slave, fd_serial;
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char * file = "/dev/ttyS0";
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if (getuid() != 0) {
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fprintf(stderr, "%s: only root can do that\n", argv[0]);
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return 1;
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}
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if (!fork()) {
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if (argc > 1) {
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file = argv[1];
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}
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syscall_openpty(&fd_master, &fd_slave, NULL, NULL, NULL);
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fd_serial = open(file, O_RDWR);
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if (!fork()) {
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dup2(fd_slave, 0);
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dup2(fd_slave, 1);
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dup2(fd_slave, 2);
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char * tokens[] = {"/bin/login",NULL};
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execvp(tokens[0], tokens);
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exit(1);
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} else {
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int fds[2] = {fd_serial, fd_master};
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while (1) {
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int index = syscall_fswait2(2,fds,200);
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char buf[1024];
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int r;
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switch (index) {
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case 0: /* fd_serial */
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r = read(fd_serial, buf, 1);
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write(fd_master, buf, 1);
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break;
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case 1: /* fd_master */
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r = read(fd_master, buf, 1024);
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write(fd_serial, buf, r);
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break;
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default: /* timeout */
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break;
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}
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}
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}
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return 1;
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}
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return 0;
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}
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