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/* vi: set sw=4 ts=4: */
/*
* Stripped down version of net-tools for busybox.
*
* Author: Ignacio Garcia Perez (iggarpe at gmail dot com)
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*
* There are some differences from the standard net-tools slattach:
*
* - The -l option is not supported.
*
* - The -F options allows disabling of RTS/CTS flow control.
*/
//config:config SLATTACH
//config: bool "slattach (6.1 kb)"
//config: default y
//config: select PLATFORM_LINUX
//config: help
//config: slattach configures serial line as SLIP network interface.
//applet:IF_SLATTACH(APPLET(slattach, BB_DIR_SBIN, BB_SUID_DROP))
/* shouldn't be NOEXEC: may sleep indefinitely */
//kbuild:lib-$(CONFIG_SLATTACH) += slattach.o
//usage:#define slattach_trivial_usage
//usage: "[-ehmLF] [-c SCRIPT] [-s BAUD] [-p PROTOCOL] SERIAL_DEVICE"
//usage:#define slattach_full_usage "\n\n"
//usage: "Configure serial line as SLIP network interface\n"
//usage: "\n -p PROT Protocol: slip, cslip (default), slip6, clisp6, adaptive"
//usage: "\n -s BAUD Line speed"
//usage: "\n -e Exit after initialization"
//usage: "\n -h Exit if carrier is lost (else never exits)"
//usage: "\n -c PROG Run PROG on carrier loss"
//usage: "\n -m Do NOT set raw 8bit mode"
//usage: "\n -L Enable 3-wire operation"
//usage: "\n -F Disable RTS/CTS flow control"
#include "libbb.h"
#include "common_bufsiz.h"
#include "libiproute/utils.h" /* invarg_1_to_2() */
struct globals {
int saved_disc;
struct termios saved_state;
} FIX_ALIASING;
#define G (*(struct globals*)bb_common_bufsiz1)
#define INIT_G() do { setup_common_bufsiz(); } while (0)
#define serial_fd 3
static int tcsetattr_serial_or_warn(struct termios *state)
{
int ret;
ret = tcsetattr(serial_fd, TCSANOW, state);
if (ret != 0) {
bb_perror_msg("tcsetattr");
return 1; /* used as exitcode */
}
return ret; /* 0 */
}
static void restore_state_and_exit(int exitcode) NORETURN;
static void restore_state_and_exit(int exitcode)
{
struct termios state;
/* Restore line discipline */
if (ioctl_or_warn(serial_fd, TIOCSETD, &G.saved_disc)) {
exitcode = 1;
}
/* Hangup */
memcpy(&state, &G.saved_state, sizeof(state));
cfsetispeed(&state, B0);
cfsetospeed(&state, B0);
exitcode |= tcsetattr_serial_or_warn(&state);
sleep(1);
/* Restore line status */
if (tcsetattr_serial_or_warn(&G.saved_state))
exit(EXIT_FAILURE);
if (ENABLE_FEATURE_CLEAN_UP)
close(serial_fd);
exit(exitcode);
}
static void sig_handler(int signo UNUSED_PARAM)
{
restore_state_and_exit(EXIT_SUCCESS);
}
int slattach_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int slattach_main(int argc UNUSED_PARAM, char **argv)
{
/* Line discipline code table */
static const char proto_names[] ALIGN1 =
"slip\0" /* 0 */
"cslip\0" /* 1 */
"slip6\0" /* 2 */
"cslip6\0" /* 3 */
"adaptive\0" /* 8 */
;
static const int int_N_SLIP = N_SLIP;
int encap, opt, fd;
struct termios state;
const char *proto = "cslip";
const char *extcmd; /* Command to execute after hangup */
const char *baud_str;
int baud_code = baud_code; /* for compiler */
enum {
OPT_p_proto = 1 << 0,
OPT_s_baud = 1 << 1,
OPT_c_extcmd = 1 << 2,
OPT_e_quit = 1 << 3,
OPT_h_watch = 1 << 4,
OPT_m_nonraw = 1 << 5,
OPT_L_local = 1 << 6,
OPT_F_noflow = 1 << 7
};
INIT_G();
/* Parse command line options */
opt_complementary = "=1";
opt = getopt32(argv, "p:s:c:ehmLF", &proto, &baud_str, &extcmd);
/*argc -= optind;*/
argv += optind;
encap = index_in_strings(proto_names, proto);
if (encap < 0)
invarg_1_to_2(proto, "protocol");
if (encap > 3)
encap = 8;
/* We want to know if the baud rate is valid before we start touching the ttys */
if (opt & OPT_s_baud) {
baud_code = tty_value_to_baud(xatoi(baud_str));
if (baud_code < 0)
invarg_1_to_2(baud_str, "baud rate");
}
/* Open tty */
fd = open(*argv, O_RDWR | O_NDELAY);
if (fd < 0) {
char *buf = concat_path_file("/dev", *argv);
fd = xopen(buf, O_RDWR | O_NDELAY);
/* maybe if (ENABLE_FEATURE_CLEAN_UP) ?? */
free(buf);
}
xmove_fd(fd, serial_fd);
/* Save current tty state */
if (tcgetattr(serial_fd, &G.saved_state) != 0)
bb_perror_msg_and_die("tcgetattr");
/* Save line discipline */
xioctl(serial_fd, TIOCGETD, &G.saved_disc);
/* Trap signals in order to restore tty states upon exit */
if (!(opt & OPT_e_quit)) {
bb_signals(0
+ (1 << SIGHUP)
+ (1 << SIGINT)
+ (1 << SIGQUIT)
+ (1 << SIGTERM)
, sig_handler);
}
/* Configure tty */
memcpy(&state, &G.saved_state, sizeof(state));
if (!(opt & OPT_m_nonraw)) { /* raw not suppressed */
memset(&state.c_cc, 0, sizeof(state.c_cc));
state.c_cc[VMIN] = 1;
state.c_iflag = IGNBRK | IGNPAR;
/*state.c_oflag = 0;*/
/*state.c_lflag = 0;*/
state.c_cflag = CS8 | HUPCL | CREAD
| ((opt & OPT_L_local) ? CLOCAL : 0)
| ((opt & OPT_F_noflow) ? 0 : CRTSCTS);
cfsetispeed(&state, cfgetispeed(&G.saved_state));
cfsetospeed(&state, cfgetospeed(&G.saved_state));
}
if (opt & OPT_s_baud) {
cfsetispeed(&state, baud_code);
cfsetospeed(&state, baud_code);
}
/* Set line status */
if (tcsetattr_serial_or_warn(&state))
goto bad;
/* Set line disclipline (N_SLIP always) */
if (ioctl_or_warn(serial_fd, TIOCSETD, (void*)&int_N_SLIP))
goto bad;
/* Set encapsulation (SLIP, CSLIP, etc) */
if (ioctl_or_warn(serial_fd, SIOCSIFENCAP, &encap))
goto bad;
/* Exit now if option -e was passed */
if (opt & OPT_e_quit)
return EXIT_SUCCESS;
/* If we're not requested to watch, just keep descriptor open
* until we are killed */
if (!(opt & OPT_h_watch))
while (1)
sleep(24*60*60);
/* Watch line for hangup */
while (1) {
int modem_stat;
if (ioctl(serial_fd, TIOCMGET, &modem_stat))
break;
if (!(modem_stat & TIOCM_CAR))
break;
sleep(15);
}
/* Execute command on hangup */
if (opt & OPT_c_extcmd)
system(extcmd);
/* Restore states and exit */
restore_state_and_exit(EXIT_SUCCESS);
bad:
restore_state_and_exit(EXIT_FAILURE);
}
|
