blob: 12a3067de219ad277f823c623282775f67d0efd8 [file] [log] [blame]
Denis Vlasenko83335872007-06-21 07:27:43 +00001/* vi: set sw=4 ts=4: */
Denis Vlasenko14923db2007-06-20 15:23:03 +00002/*
3 * Stripped down version of net-tools for busybox.
4 *
5 * Author: Ignacio Garcia Perez (iggarpe at gmail dot com)
6 *
7 * License: GPLv2 or later, see LICENSE file in this tarball.
8 *
9 * There are some differences from the standard net-tools slattach:
10 *
11 * - The -l option is not supported.
12 *
13 * - The -F options allows disabling of RTS/CTS flow control.
14 */
15
16#include "libbb.h"
Denis Vlasenko83335872007-06-21 07:27:43 +000017#include "libiproute/utils.h" /* invarg() */
Denis Vlasenko14923db2007-06-20 15:23:03 +000018
Denis Vlasenko14923db2007-06-20 15:23:03 +000019struct globals {
20 int handle;
21 int saved_disc;
22 struct termios saved_state;
Denys Vlasenko98a4c7c2010-02-04 15:00:15 +010023} FIX_ALIASING;
Denis Vlasenko14923db2007-06-20 15:23:03 +000024#define G (*(struct globals*)&bb_common_bufsiz1)
25#define handle (G.handle )
26#define saved_disc (G.saved_disc )
27#define saved_state (G.saved_state )
Denis Vlasenko7049ff82008-06-25 09:53:17 +000028#define INIT_G() do { } while (0)
Denis Vlasenko14923db2007-06-20 15:23:03 +000029
30
31/*
32 * Save tty state and line discipline
33 *
34 * It is fine here to bail out on errors, since we haven modified anything yet
35 */
36static void save_state(void)
37{
38 /* Save line status */
39 if (tcgetattr(handle, &saved_state) < 0)
40 bb_perror_msg_and_die("get state");
41
42 /* Save line discipline */
Denis Vlasenkofb79a2e2007-07-14 22:07:14 +000043 xioctl(handle, TIOCGETD, &saved_disc);
Denis Vlasenko14923db2007-06-20 15:23:03 +000044}
45
Denis Vlasenko400d8bb2008-02-24 13:36:01 +000046static int set_termios_state_or_warn(struct termios *state)
Denis Vlasenko83335872007-06-21 07:27:43 +000047{
48 int ret;
49
50 ret = tcsetattr(handle, TCSANOW, state);
51 if (ret < 0) {
52 bb_perror_msg("set state");
53 return 1; /* used as exitcode */
54 }
55 return 0;
56}
57
Denis Vlasenko14923db2007-06-20 15:23:03 +000058/*
59 * Restore state and line discipline for ALL managed ttys
60 *
61 * Restoring ALL managed ttys is the only way to have a single
62 * hangup delay.
63 *
64 * Go on after errors: we want to restore as many controlled ttys
65 * as possible.
66 */
Denis Vlasenkoa60f84e2008-07-05 09:18:54 +000067static void restore_state_and_exit(int exitcode) NORETURN;
Denis Vlasenko14923db2007-06-20 15:23:03 +000068static void restore_state_and_exit(int exitcode)
69{
70 struct termios state;
71
72 /* Restore line discipline */
Denis Vlasenkofb79a2e2007-07-14 22:07:14 +000073 if (ioctl_or_warn(handle, TIOCSETD, &saved_disc) < 0) {
Denis Vlasenko14923db2007-06-20 15:23:03 +000074 exitcode = 1;
75 }
76
77 /* Hangup */
78 memcpy(&state, &saved_state, sizeof(state));
79 cfsetispeed(&state, B0);
80 cfsetospeed(&state, B0);
Denis Vlasenko400d8bb2008-02-24 13:36:01 +000081 if (set_termios_state_or_warn(&state))
Denis Vlasenko14923db2007-06-20 15:23:03 +000082 exitcode = 1;
Denis Vlasenko14923db2007-06-20 15:23:03 +000083 sleep(1);
84
85 /* Restore line status */
Denis Vlasenko400d8bb2008-02-24 13:36:01 +000086 if (set_termios_state_or_warn(&saved_state))
Denis Vlasenko83335872007-06-21 07:27:43 +000087 exit(EXIT_FAILURE);
Denis Vlasenko14923db2007-06-20 15:23:03 +000088 if (ENABLE_FEATURE_CLEAN_UP)
89 close(handle);
90
91 exit(exitcode);
92}
93
94/*
95 * Set tty state, line discipline and encapsulation
96 */
97static void set_state(struct termios *state, int encap)
98{
99 int disc;
100
101 /* Set line status */
Denis Vlasenko400d8bb2008-02-24 13:36:01 +0000102 if (set_termios_state_or_warn(state))
Denis Vlasenko14923db2007-06-20 15:23:03 +0000103 goto bad;
Denis Vlasenko14923db2007-06-20 15:23:03 +0000104 /* Set line discliple (N_SLIP always) */
105 disc = N_SLIP;
Denis Vlasenkofb79a2e2007-07-14 22:07:14 +0000106 if (ioctl_or_warn(handle, TIOCSETD, &disc) < 0) {
Denis Vlasenko14923db2007-06-20 15:23:03 +0000107 goto bad;
108 }
109
110 /* Set encapsulation (SLIP, CSLIP, etc) */
Denis Vlasenkofb79a2e2007-07-14 22:07:14 +0000111 if (ioctl_or_warn(handle, SIOCSIFENCAP, &encap) < 0) {
Denis Vlasenko14923db2007-06-20 15:23:03 +0000112 bad:
Bernhard Reutner-Fischer636a1f82008-05-19 09:29:47 +0000113 restore_state_and_exit(EXIT_FAILURE);
Denis Vlasenko14923db2007-06-20 15:23:03 +0000114 }
115}
116
Denis Vlasenkoa60f84e2008-07-05 09:18:54 +0000117static void sig_handler(int signo UNUSED_PARAM)
Denis Vlasenko14923db2007-06-20 15:23:03 +0000118{
Bernhard Reutner-Fischer636a1f82008-05-19 09:29:47 +0000119 restore_state_and_exit(EXIT_SUCCESS);
Denis Vlasenko14923db2007-06-20 15:23:03 +0000120}
121
Denis Vlasenko9b49a5e2007-10-11 10:05:36 +0000122int slattach_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
Denis Vlasenkoa60f84e2008-07-05 09:18:54 +0000123int slattach_main(int argc UNUSED_PARAM, char **argv)
Denis Vlasenko14923db2007-06-20 15:23:03 +0000124{
Denis Vlasenko990d0f62007-07-24 15:54:42 +0000125 /* Line discipline code table */
Denis Vlasenko6ca409e2007-08-12 20:58:27 +0000126 static const char proto_names[] ALIGN1 =
Denis Vlasenko990d0f62007-07-24 15:54:42 +0000127 "slip\0" /* 0 */
128 "cslip\0" /* 1 */
129 "slip6\0" /* 2 */
130 "cslip6\0" /* 3 */
131 "adaptive\0" /* 8 */
132 ;
133
Denis Vlasenko14923db2007-06-20 15:23:03 +0000134 int i, encap, opt;
135 struct termios state;
136 const char *proto = "cslip";
137 const char *extcmd; /* Command to execute after hangup */
138 const char *baud_str;
139 int baud_code = -1; /* Line baud rate (system code) */
140
141 enum {
142 OPT_p_proto = 1 << 0,
143 OPT_s_baud = 1 << 1,
144 OPT_c_extcmd = 1 << 2,
145 OPT_e_quit = 1 << 3,
146 OPT_h_watch = 1 << 4,
147 OPT_m_nonraw = 1 << 5,
148 OPT_L_local = 1 << 6,
Denis Vlasenko83335872007-06-21 07:27:43 +0000149 OPT_F_noflow = 1 << 7
Denis Vlasenko14923db2007-06-20 15:23:03 +0000150 };
151
152 INIT_G();
153
154 /* Parse command line options */
Denis Vlasenkofe7cd642007-08-18 15:32:12 +0000155 opt = getopt32(argv, "p:s:c:ehmLF", &proto, &baud_str, &extcmd);
Denis Vlasenko14923db2007-06-20 15:23:03 +0000156 /*argc -= optind;*/
157 argv += optind;
158
159 if (!*argv)
160 bb_show_usage();
161
Denis Vlasenko990d0f62007-07-24 15:54:42 +0000162 encap = index_in_strings(proto_names, proto);
Denis Vlasenko14923db2007-06-20 15:23:03 +0000163
164 if (encap < 0)
Denis Vlasenko83335872007-06-21 07:27:43 +0000165 invarg(proto, "protocol");
Denis Vlasenko14923db2007-06-20 15:23:03 +0000166 if (encap > 3)
167 encap = 8;
168
169 /* We want to know if the baud rate is valid before we start touching the ttys */
170 if (opt & OPT_s_baud) {
171 baud_code = tty_value_to_baud(xatoi(baud_str));
172 if (baud_code < 0)
Denis Vlasenko83335872007-06-21 07:27:43 +0000173 invarg(baud_str, "baud rate");
Denis Vlasenko14923db2007-06-20 15:23:03 +0000174 }
175
176 /* Trap signals in order to restore tty states upon exit */
177 if (!(opt & OPT_e_quit)) {
Denis Vlasenko25591c32008-02-16 22:58:56 +0000178 bb_signals(0
179 + (1 << SIGHUP)
180 + (1 << SIGINT)
181 + (1 << SIGQUIT)
182 + (1 << SIGTERM)
183 , sig_handler);
Denis Vlasenko14923db2007-06-20 15:23:03 +0000184 }
185
Denis Vlasenko83335872007-06-21 07:27:43 +0000186 /* Open tty */
Denis Vlasenko14923db2007-06-20 15:23:03 +0000187 handle = open(*argv, O_RDWR | O_NDELAY);
188 if (handle < 0) {
Denis Vlasenko83335872007-06-21 07:27:43 +0000189 char *buf = concat_path_file("/dev", *argv);
Denis Vlasenko14923db2007-06-20 15:23:03 +0000190 handle = xopen(buf, O_RDWR | O_NDELAY);
191 /* maybe if (ENABLE_FEATURE_CLEAN_UP) ?? */
192 free(buf);
193 }
194
195 /* Save current tty state */
196 save_state();
197
Denis Vlasenko83335872007-06-21 07:27:43 +0000198 /* Configure tty */
Denis Vlasenko14923db2007-06-20 15:23:03 +0000199 memcpy(&state, &saved_state, sizeof(state));
200 if (!(opt & OPT_m_nonraw)) { /* raw not suppressed */
201 memset(&state.c_cc, 0, sizeof(state.c_cc));
202 state.c_cc[VMIN] = 1;
203 state.c_iflag = IGNBRK | IGNPAR;
204 state.c_oflag = 0;
205 state.c_lflag = 0;
206 state.c_cflag = CS8 | HUPCL | CREAD
207 | ((opt & OPT_L_local) ? CLOCAL : 0)
208 | ((opt & OPT_F_noflow) ? 0 : CRTSCTS);
Denis Vlasenko28f56192008-09-16 21:27:59 +0000209 cfsetispeed(&state, cfgetispeed(&saved_state));
210 cfsetospeed(&state, cfgetospeed(&saved_state));
Denis Vlasenko14923db2007-06-20 15:23:03 +0000211 }
212
213 if (opt & OPT_s_baud) {
214 cfsetispeed(&state, baud_code);
215 cfsetospeed(&state, baud_code);
216 }
217
218 set_state(&state, encap);
219
220 /* Exit now if option -e was passed */
221 if (opt & OPT_e_quit)
222 return 0;
223
224 /* If we're not requested to watch, just keep descriptor open
Denis Vlasenko83335872007-06-21 07:27:43 +0000225 * until we are killed */
Denis Vlasenko14923db2007-06-20 15:23:03 +0000226 if (!(opt & OPT_h_watch))
227 while (1)
228 sleep(24*60*60);
229
230 /* Watch line for hangup */
231 while (1) {
232 if (ioctl(handle, TIOCMGET, &i) < 0 || !(i & TIOCM_CAR))
233 goto no_carrier;
234 sleep(15);
235 }
236
237 no_carrier:
238
239 /* Execute command on hangup */
240 if (opt & OPT_c_extcmd)
241 system(extcmd);
242
243 /* Restore states and exit */
Bernhard Reutner-Fischer636a1f82008-05-19 09:29:47 +0000244 restore_state_and_exit(EXIT_SUCCESS);
Denis Vlasenko14923db2007-06-20 15:23:03 +0000245}