| /* getty.c - A getty program to get controlling terminal. |
| * |
| * Copyright 2012 Sandeep Sharma <sandeep.jack2756@gamil.com> |
| * Copyright 2013 Kyungwan Han <asura321@gmail.com> |
| * |
| * No Standard. |
| |
| USE_GETTY(NEWTOY(getty, "<2t#<0H:I:l:f:iwnmLh", TOYFLAG_SBIN)) |
| |
| config GETTY |
| bool "getty" |
| default n |
| help |
| usage: getty [OPTIONS] BAUD_RATE[,BAUD_RATE]... TTY [TERMTYPE] |
| |
| Wait for a modem to dial into serial port, adjust baud rate, call login. |
| |
| -h Enable hardware RTS/CTS flow control |
| -L Set CLOCAL (ignore Carrier Detect state) |
| -m Get baud rate from modem's CONNECT status message |
| -n Don't prompt for login name |
| -w Wait for CR or LF before sending /etc/issue |
| -i Don't display /etc/issue |
| -f ISSUE_FILE Display ISSUE_FILE instead of /etc/issue |
| -l LOGIN Invoke LOGIN instead of /bin/login |
| -t SEC Terminate after SEC if no login name is read |
| -I INITSTR Send INITSTR before anything else |
| -H HOST Log HOST into the utmp file as the hostname |
| */ |
| |
| #define FOR_getty |
| #include "toys.h" |
| |
| GLOBALS( |
| char *f, *l, *I, *H; |
| long t; |
| |
| char *tty_name, buff[128]; |
| int speeds[20], sc; |
| struct termios termios; |
| ) |
| |
| #define CTL(x) ((x) ^ 0100) |
| #define HOSTNAME_SIZE 32 |
| |
| static void parse_speeds(char *sp) |
| { |
| char *ptr; |
| |
| TT.sc = 0; |
| while ((ptr = strsep(&sp, ","))) { |
| TT.speeds[TT.sc] = atolx_range(ptr, 0, INT_MAX); |
| if (TT.speeds[TT.sc] < 0) perror_exit("bad speed %s", ptr); |
| if (++TT.sc > 10) perror_exit("too many speeds, max is 10"); |
| } |
| } |
| |
| // Get controlling terminal and redirect stdio |
| static void open_tty(void) |
| { |
| if (strcmp(TT.tty_name, "-")) { |
| if (*(TT.tty_name) != '/') TT.tty_name = xmprintf("/dev/%s", TT.tty_name); |
| // Sends SIGHUP to all foreground process if Session leader don't die,Ignore |
| void* handler = signal(SIGHUP, SIG_IGN); |
| ioctl(0, TIOCNOTTY, 0); // Giveup if there is any controlling terminal |
| signal(SIGHUP, handler); |
| if ((setsid() < 0) && (getpid() != getsid(0))) perror_exit("setsid"); |
| xclose(0); |
| xopen_stdio(TT.tty_name, O_RDWR|O_NDELAY|O_CLOEXEC); |
| fcntl(0, F_SETFL, fcntl(0, F_GETFL) & ~O_NONBLOCK); // Block read |
| dup2(0, 1); |
| dup2(0, 2); |
| if (ioctl(0, TIOCSCTTY, 1) < 0) perror_msg("ioctl(TIOCSCTTY)"); |
| if (!isatty(0)) perror_exit("/dev/%s: not a tty", TT.tty_name); |
| chown(TT.tty_name, 0, 0); // change ownership, Hope login will change this |
| chmod(TT.tty_name, 0620); |
| } else { // We already have opened TTY |
| if (setsid() < 0) perror_msg("setsid failed"); |
| if ((fcntl(0, F_GETFL) & (O_RDWR|O_RDONLY|O_WRONLY)) != O_RDWR) |
| perror_exit("no read/write permission"); |
| } |
| } |
| |
| static void termios_init(void) |
| { |
| if (tcgetattr(0, &TT.termios) < 0) perror_exit("tcgetattr"); |
| // Flush input and output queues, important for modems! |
| tcflush(0, TCIOFLUSH); |
| TT.termios.c_cflag &= (0|CSTOPB|PARENB|PARODD); |
| #ifdef CRTSCTS |
| if (FLAG(h)) TT.termios.c_cflag |= CRTSCTS; |
| #endif |
| if (FLAG(L)) TT.termios.c_cflag |= CLOCAL; |
| TT.termios.c_cc[VTIME] = 0; |
| TT.termios.c_cc[VMIN] = 1; |
| TT.termios.c_oflag = OPOST|ONLCR; |
| TT.termios.c_cflag |= CS8|CREAD|HUPCL|CBAUDEX; |
| // login will disable echo for passwd. |
| TT.termios.c_lflag |= ISIG|ICANON|ECHO|ECHOE|ECHOK|ECHOKE; |
| TT.termios.c_cc[VINTR] = CTL('C'); |
| TT.termios.c_cc[VQUIT] = CTL('\\'); |
| TT.termios.c_cc[VEOF] = CTL('D'); |
| TT.termios.c_cc[VEOL] = '\n'; |
| TT.termios.c_cc[VKILL] = CTL('U'); |
| TT.termios.c_cc[VERASE] = 127; // CERASE |
| TT.termios.c_iflag = ICRNL|IXON|IXOFF; |
| // Set non-zero baud rate. Zero baud rate left it unchanged. |
| if (TT.speeds[0] != 0) xsetspeed(&TT.termios, TT.speeds[0]); |
| if (tcsetattr(0, TCSANOW, &TT.termios) < 0) perror_exit("tcsetattr"); |
| } |
| |
| // Get the baud rate from modems CONNECT mesage, Its of form <junk><BAUD><Junk> |
| static void sense_baud(void) |
| { |
| int vmin, speed; |
| ssize_t size; |
| char *ptr; |
| |
| vmin = TT.termios.c_cc[VMIN]; // Store old |
| TT.termios.c_cc[VMIN] = 0; // No block even queue is empty. |
| if (tcsetattr(0, TCSANOW, &TT.termios) < 0) perror_exit("tcsetattr"); |
| size = readall(0, TT.buff, sizeof(TT.buff)-1); |
| if (size > 0) { |
| for (ptr = TT.buff; ptr < TT.buff+size; ptr++) { |
| if (isdigit(*ptr)) { |
| speed = atolx_range(ptr, 0, INT_MAX); |
| if (speed > 0) xsetspeed(&TT.termios, speed); |
| break; |
| } |
| } |
| } |
| TT.termios.c_cc[VMIN] = vmin; //restore old value |
| if (tcsetattr(0, TCSANOW, &TT.termios) < 0) perror_exit("tcsetattr"); |
| } |
| |
| // Print /etc/isuue with taking care of each escape sequence |
| void write_issue(char *file, struct utsname *uts) |
| { |
| char buff[20] = {0,}; |
| int fd = open(TT.f, O_RDONLY), size; |
| |
| if (fd < 0) return; |
| while ((size = readall(fd, buff, 1)) > 0) { |
| char *ch = buff; |
| |
| if (*ch == '\\' || *ch == '%') { |
| if (readall(fd, buff, 1) <= 0) perror_exit("readall"); |
| if (*ch == 's') fputs(uts->sysname, stdout); |
| if (*ch == 'n'|| *ch == 'h') fputs(uts->nodename, stdout); |
| if (*ch == 'r') fputs(uts->release, stdout); |
| if (*ch == 'm') fputs(uts->machine, stdout); |
| if (*ch == 'l') fputs(TT.tty_name, stdout); |
| } else xputc(*ch); |
| } |
| } |
| |
| // Read login name and print prompt and Issue file. |
| static int read_login_name(void) |
| { |
| tcflush(0, TCIFLUSH); // Flush pending speed switches |
| while (1) { |
| struct utsname uts; |
| int i = 0; |
| |
| uname(&uts); |
| |
| if (!FLAG(i)) write_issue(TT.f, &uts); |
| |
| printf("%s login: ", uts.nodename); |
| xflush(1); |
| |
| TT.buff[0] = getchar(); |
| if (!TT.buff[0] && TT.sc > 1) return 0; // Switch speed |
| if (TT.buff[0] == '\n') continue; |
| if (TT.buff[0] != '\n') |
| if (!fgets(&TT.buff[1], HOSTNAME_SIZE-1, stdin)) _exit(1); |
| while (i < HOSTNAME_SIZE-1 && isgraph(TT.buff[i])) i++; |
| TT.buff[i] = 0; |
| break; |
| } |
| return 1; |
| } |
| |
| static void utmp_entry(void) |
| { |
| struct utmpx entry = {.ut_pid = getpid()}, *ep; |
| int fd; |
| |
| // We're responsible for ensuring that the utmp file exists. |
| if (access(_PATH_UTMP, F_OK) && (fd = open(_PATH_UTMP, O_CREAT, 0664)) != -1) |
| close(fd); |
| |
| // Find any existing entry. |
| setutxent(); |
| while ((ep = getutxent())) |
| if (ep->ut_pid == entry.ut_pid && ep->ut_type >= INIT_PROCESS) break; |
| if (ep) entry = *ep; |
| else entry.ut_type = LOGIN_PROCESS; |
| |
| // Modify. |
| entry.ut_tv.tv_sec = time(0); |
| xstrncpy(entry.ut_user, "LOGIN", sizeof(entry.ut_user)); |
| xstrncpy(entry.ut_line, ttyname(0) + strlen("/dev/"), sizeof(entry.ut_line)); |
| if (FLAG(H)) xstrncpy(entry.ut_host, TT.H, sizeof(entry.ut_host)); |
| |
| // Write. |
| pututxline(&entry); |
| endutxent(); |
| } |
| |
| void getty_main(void) |
| { |
| char ch, *cmd[3] = {TT.l ? : "/bin/login", 0, 0}; // space to add username |
| |
| if (!FLAG(f)) TT.f = "/etc/issue"; |
| |
| // parse arguments and set $TERM |
| if (isdigit(**toys.optargs)) { |
| parse_speeds(*toys.optargs); |
| if (*++toys.optargs) TT.tty_name = xmprintf("%s", *toys.optargs); |
| } else { |
| TT.tty_name = xmprintf("%s", *toys.optargs); |
| if (*++toys.optargs) parse_speeds(*toys.optargs); |
| } |
| if (*++toys.optargs) setenv("TERM", *toys.optargs, 1); |
| |
| open_tty(); |
| termios_init(); |
| tcsetpgrp(0, getpid()); |
| utmp_entry(); |
| if (FLAG(I)) xputsn(TT.I); |
| if (FLAG(m)) sense_baud(); |
| if (FLAG(t)) alarm(TT.t); |
| if (FLAG(w)) while (readall(0, &ch, 1) != 1) if (ch=='\n' || ch=='\r') break; |
| if (!FLAG(n)) { |
| int index = 1; // 0th we already set. |
| |
| for (;;) { |
| if (read_login_name()) break; |
| index %= TT.sc; |
| xsetspeed(&TT.termios, TT.speeds[index]); |
| //Necessary after cfsetspeed |
| if (tcsetattr(0, TCSANOW, &TT.termios) < 0) perror_exit("tcsetattr"); |
| } |
| cmd[1] = TT.buff; //put the username in the login command line |
| } |
| xexec(cmd); |
| } |