1 /* vi: set sw=4 ts=4: */
3 * Stripped down version of net-tools for busybox.
5 * Author: Ignacio Garcia Perez (iggarpe at gmail dot com)
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
9 * There are some differences from the standard net-tools slattach:
11 * - The -l option is not supported.
13 * - The -F options allows disabling of RTS/CTS flow control.
15 //config:config SLATTACH
16 //config: bool "slattach (6.1 kb)"
18 //config: select PLATFORM_LINUX
20 //config: slattach configures serial line as SLIP network interface.
22 //applet:IF_SLATTACH(APPLET(slattach, BB_DIR_SBIN, BB_SUID_DROP))
23 /* shouldn't be NOEXEC: may sleep indefinitely */
25 //kbuild:lib-$(CONFIG_SLATTACH) += slattach.o
27 //usage:#define slattach_trivial_usage
28 //usage: "[-ehmLF] [-c SCRIPT] [-s BAUD] [-p PROTOCOL] SERIAL_DEVICE"
29 //usage:#define slattach_full_usage "\n\n"
30 //usage: "Configure serial line as SLIP network interface\n"
31 //usage: "\n -p PROT Protocol: slip, cslip (default), slip6, clisp6, adaptive"
32 //usage: "\n -s BAUD Line speed"
33 //usage: "\n -e Exit after initialization"
34 //usage: "\n -h Exit if carrier is lost (else never exits)"
35 //usage: "\n -c PROG Run PROG on carrier loss"
36 //usage: "\n -m Do NOT set raw 8bit mode"
37 //usage: "\n -L Enable 3-wire operation"
38 //usage: "\n -F Disable RTS/CTS flow control"
41 #include "common_bufsiz.h"
42 #include "libiproute/utils.h" /* invarg_1_to_2() */
46 struct termios saved_state;
48 #define G (*(struct globals*)bb_common_bufsiz1)
49 #define INIT_G() do { setup_common_bufsiz(); } while (0)
53 static int tcsetattr_serial_or_warn(struct termios *state)
57 ret = tcsetattr(serial_fd, TCSANOW, state);
59 bb_perror_msg("tcsetattr");
60 return 1; /* used as exitcode */
65 static void restore_state_and_exit(int exitcode) NORETURN;
66 static void restore_state_and_exit(int exitcode)
70 /* Restore line discipline */
71 if (ioctl_or_warn(serial_fd, TIOCSETD, &G.saved_disc)) {
76 memcpy(&state, &G.saved_state, sizeof(state));
77 cfsetispeed(&state, B0);
78 cfsetospeed(&state, B0);
79 exitcode |= tcsetattr_serial_or_warn(&state);
82 /* Restore line status */
83 if (tcsetattr_serial_or_warn(&G.saved_state))
86 if (ENABLE_FEATURE_CLEAN_UP)
92 static void sig_handler(int signo UNUSED_PARAM)
94 restore_state_and_exit(EXIT_SUCCESS);
97 int slattach_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
98 int slattach_main(int argc UNUSED_PARAM, char **argv)
100 /* Line discipline code table */
101 static const char proto_names[] ALIGN1 =
108 static const int int_N_SLIP = N_SLIP;
111 struct termios state;
112 const char *proto = "cslip";
113 const char *extcmd; /* Command to execute after hangup */
114 const char *baud_str;
115 int baud_code = baud_code; /* for compiler */
118 OPT_p_proto = 1 << 0,
120 OPT_c_extcmd = 1 << 2,
122 OPT_h_watch = 1 << 4,
123 OPT_m_nonraw = 1 << 5,
124 OPT_L_local = 1 << 6,
125 OPT_F_noflow = 1 << 7
130 /* Parse command line options */
131 opt_complementary = "=1";
132 opt = getopt32(argv, "p:s:c:ehmLF", &proto, &baud_str, &extcmd);
136 encap = index_in_strings(proto_names, proto);
138 invarg_1_to_2(proto, "protocol");
142 /* We want to know if the baud rate is valid before we start touching the ttys */
143 if (opt & OPT_s_baud) {
144 baud_code = tty_value_to_baud(xatoi(baud_str));
146 invarg_1_to_2(baud_str, "baud rate");
150 fd = open(*argv, O_RDWR | O_NDELAY);
152 char *buf = concat_path_file("/dev", *argv);
153 fd = xopen(buf, O_RDWR | O_NDELAY);
154 /* maybe if (ENABLE_FEATURE_CLEAN_UP) ?? */
157 xmove_fd(fd, serial_fd);
159 /* Save current tty state */
160 if (tcgetattr(serial_fd, &G.saved_state) != 0)
161 bb_perror_msg_and_die("tcgetattr");
162 /* Save line discipline */
163 xioctl(serial_fd, TIOCGETD, &G.saved_disc);
165 /* Trap signals in order to restore tty states upon exit */
166 if (!(opt & OPT_e_quit)) {
176 memcpy(&state, &G.saved_state, sizeof(state));
177 if (!(opt & OPT_m_nonraw)) { /* raw not suppressed */
178 memset(&state.c_cc, 0, sizeof(state.c_cc));
179 state.c_cc[VMIN] = 1;
180 state.c_iflag = IGNBRK | IGNPAR;
181 /*state.c_oflag = 0;*/
182 /*state.c_lflag = 0;*/
183 state.c_cflag = CS8 | HUPCL | CREAD
184 | ((opt & OPT_L_local) ? CLOCAL : 0)
185 | ((opt & OPT_F_noflow) ? 0 : CRTSCTS);
186 cfsetispeed(&state, cfgetispeed(&G.saved_state));
187 cfsetospeed(&state, cfgetospeed(&G.saved_state));
189 if (opt & OPT_s_baud) {
190 cfsetispeed(&state, baud_code);
191 cfsetospeed(&state, baud_code);
193 /* Set line status */
194 if (tcsetattr_serial_or_warn(&state))
196 /* Set line disclipline (N_SLIP always) */
197 if (ioctl_or_warn(serial_fd, TIOCSETD, (void*)&int_N_SLIP))
199 /* Set encapsulation (SLIP, CSLIP, etc) */
200 if (ioctl_or_warn(serial_fd, SIOCSIFENCAP, &encap))
203 /* Exit now if option -e was passed */
204 if (opt & OPT_e_quit)
207 /* If we're not requested to watch, just keep descriptor open
208 * until we are killed */
209 if (!(opt & OPT_h_watch))
213 /* Watch line for hangup */
216 if (ioctl(serial_fd, TIOCMGET, &modem_stat))
218 if (!(modem_stat & TIOCM_CAR))
223 /* Execute command on hangup */
224 if (opt & OPT_c_extcmd)
227 /* Restore states and exit */
228 restore_state_and_exit(EXIT_SUCCESS);
230 restore_state_and_exit(EXIT_FAILURE);