blob: 4bac879d29d8aee2683f118d819d4d0f0614e493 [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;
23};
24#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 )
28#define INIT_G() do {} while (0)
29
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 Vlasenko83335872007-06-21 07:27:43 +000046static int set_termios_state_and_warn(struct termios *state)
47{
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 */
67static void restore_state_and_exit(int exitcode) ATTRIBUTE_NORETURN;
68static 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 Vlasenko83335872007-06-21 07:27:43 +000081 if (set_termios_state_and_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 Vlasenko83335872007-06-21 07:27:43 +000086 if (set_termios_state_and_warn(&saved_state))
87 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 Vlasenko83335872007-06-21 07:27:43 +0000102 if (set_termios_state_and_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:
113 restore_state_and_exit(1);
114 }
115}
116
117static void sig_handler(int signo)
118{
119 restore_state_and_exit(0);
120}
121
122int slattach_main(int argc, char **argv);
123int slattach_main(int argc, char **argv)
124{
Denis Vlasenko990d0f62007-07-24 15:54:42 +0000125 /* Line discipline code table */
126 static const char proto_names[] =
127 "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 */
155 opt = getopt32(argc, argv, "p:s:c:ehmLF", &proto, &baud_str, &extcmd);
156 /*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)) {
178 signal(SIGHUP, sig_handler);
179 signal(SIGINT, sig_handler);
180 signal(SIGQUIT, sig_handler);
181 signal(SIGTERM, sig_handler);
182 }
183
Denis Vlasenko83335872007-06-21 07:27:43 +0000184 /* Open tty */
Denis Vlasenko14923db2007-06-20 15:23:03 +0000185 handle = open(*argv, O_RDWR | O_NDELAY);
186 if (handle < 0) {
Denis Vlasenko83335872007-06-21 07:27:43 +0000187 char *buf = concat_path_file("/dev", *argv);
Denis Vlasenko14923db2007-06-20 15:23:03 +0000188 handle = xopen(buf, O_RDWR | O_NDELAY);
189 /* maybe if (ENABLE_FEATURE_CLEAN_UP) ?? */
190 free(buf);
191 }
192
193 /* Save current tty state */
194 save_state();
195
Denis Vlasenko83335872007-06-21 07:27:43 +0000196 /* Configure tty */
Denis Vlasenko14923db2007-06-20 15:23:03 +0000197 memcpy(&state, &saved_state, sizeof(state));
198 if (!(opt & OPT_m_nonraw)) { /* raw not suppressed */
199 memset(&state.c_cc, 0, sizeof(state.c_cc));
200 state.c_cc[VMIN] = 1;
201 state.c_iflag = IGNBRK | IGNPAR;
202 state.c_oflag = 0;
203 state.c_lflag = 0;
204 state.c_cflag = CS8 | HUPCL | CREAD
205 | ((opt & OPT_L_local) ? CLOCAL : 0)
206 | ((opt & OPT_F_noflow) ? 0 : CRTSCTS);
207 }
208
209 if (opt & OPT_s_baud) {
210 cfsetispeed(&state, baud_code);
211 cfsetospeed(&state, baud_code);
212 }
213
214 set_state(&state, encap);
215
216 /* Exit now if option -e was passed */
217 if (opt & OPT_e_quit)
218 return 0;
219
220 /* If we're not requested to watch, just keep descriptor open
Denis Vlasenko83335872007-06-21 07:27:43 +0000221 * until we are killed */
Denis Vlasenko14923db2007-06-20 15:23:03 +0000222 if (!(opt & OPT_h_watch))
223 while (1)
224 sleep(24*60*60);
225
226 /* Watch line for hangup */
227 while (1) {
228 if (ioctl(handle, TIOCMGET, &i) < 0 || !(i & TIOCM_CAR))
229 goto no_carrier;
230 sleep(15);
231 }
232
233 no_carrier:
234
235 /* Execute command on hangup */
236 if (opt & OPT_c_extcmd)
237 system(extcmd);
238
239 /* Restore states and exit */
240 restore_state_and_exit(0);
241}