1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
|
/* 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 (6.2 kb)"
//config: default y
//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_simple_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 = getopt32(argv, "^" "p:s:c:ehmLF" "\0" "=1",
&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_simple_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);
}
|
