Denis Vlasenko | 8333587 | 2007-06-21 07:27:43 +0000 | [diff] [blame] | 1 | /* vi: set sw=4 ts=4: */ |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 2 | /* |
| 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 Vlasenko | 8333587 | 2007-06-21 07:27:43 +0000 | [diff] [blame] | 17 | #include "libiproute/utils.h" /* invarg() */ |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 18 | |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 19 | struct 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 | */ |
| 36 | static 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 Vlasenko | fb79a2e | 2007-07-14 22:07:14 +0000 | [diff] [blame] | 43 | xioctl(handle, TIOCGETD, &saved_disc); |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 44 | } |
| 45 | |
Denis Vlasenko | 8333587 | 2007-06-21 07:27:43 +0000 | [diff] [blame] | 46 | static 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 Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 58 | /* |
| 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 | */ |
| 67 | static void restore_state_and_exit(int exitcode) ATTRIBUTE_NORETURN; |
| 68 | static void restore_state_and_exit(int exitcode) |
| 69 | { |
| 70 | struct termios state; |
| 71 | |
| 72 | /* Restore line discipline */ |
Denis Vlasenko | fb79a2e | 2007-07-14 22:07:14 +0000 | [diff] [blame] | 73 | if (ioctl_or_warn(handle, TIOCSETD, &saved_disc) < 0) { |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 74 | exitcode = 1; |
| 75 | } |
| 76 | |
| 77 | /* Hangup */ |
| 78 | memcpy(&state, &saved_state, sizeof(state)); |
| 79 | cfsetispeed(&state, B0); |
| 80 | cfsetospeed(&state, B0); |
Denis Vlasenko | 8333587 | 2007-06-21 07:27:43 +0000 | [diff] [blame] | 81 | if (set_termios_state_and_warn(&state)) |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 82 | exitcode = 1; |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 83 | sleep(1); |
| 84 | |
| 85 | /* Restore line status */ |
Denis Vlasenko | 8333587 | 2007-06-21 07:27:43 +0000 | [diff] [blame] | 86 | if (set_termios_state_and_warn(&saved_state)) |
| 87 | exit(EXIT_FAILURE); |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 88 | if (ENABLE_FEATURE_CLEAN_UP) |
| 89 | close(handle); |
| 90 | |
| 91 | exit(exitcode); |
| 92 | } |
| 93 | |
| 94 | /* |
| 95 | * Set tty state, line discipline and encapsulation |
| 96 | */ |
| 97 | static void set_state(struct termios *state, int encap) |
| 98 | { |
| 99 | int disc; |
| 100 | |
| 101 | /* Set line status */ |
Denis Vlasenko | 8333587 | 2007-06-21 07:27:43 +0000 | [diff] [blame] | 102 | if (set_termios_state_and_warn(state)) |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 103 | goto bad; |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 104 | /* Set line discliple (N_SLIP always) */ |
| 105 | disc = N_SLIP; |
Denis Vlasenko | fb79a2e | 2007-07-14 22:07:14 +0000 | [diff] [blame] | 106 | if (ioctl_or_warn(handle, TIOCSETD, &disc) < 0) { |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 107 | goto bad; |
| 108 | } |
| 109 | |
| 110 | /* Set encapsulation (SLIP, CSLIP, etc) */ |
Denis Vlasenko | fb79a2e | 2007-07-14 22:07:14 +0000 | [diff] [blame] | 111 | if (ioctl_or_warn(handle, SIOCSIFENCAP, &encap) < 0) { |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 112 | bad: |
| 113 | restore_state_and_exit(1); |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | static void sig_handler(int signo) |
| 118 | { |
| 119 | restore_state_and_exit(0); |
| 120 | } |
| 121 | |
| 122 | int slattach_main(int argc, char **argv); |
| 123 | int slattach_main(int argc, char **argv) |
| 124 | { |
Denis Vlasenko | 990d0f6 | 2007-07-24 15:54:42 +0000 | [diff] [blame^] | 125 | /* 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 Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 134 | 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 Vlasenko | 8333587 | 2007-06-21 07:27:43 +0000 | [diff] [blame] | 149 | OPT_F_noflow = 1 << 7 |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 150 | }; |
| 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 Vlasenko | 990d0f6 | 2007-07-24 15:54:42 +0000 | [diff] [blame^] | 162 | encap = index_in_strings(proto_names, proto); |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 163 | |
| 164 | if (encap < 0) |
Denis Vlasenko | 8333587 | 2007-06-21 07:27:43 +0000 | [diff] [blame] | 165 | invarg(proto, "protocol"); |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 166 | 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 Vlasenko | 8333587 | 2007-06-21 07:27:43 +0000 | [diff] [blame] | 173 | invarg(baud_str, "baud rate"); |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 174 | } |
| 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 Vlasenko | 8333587 | 2007-06-21 07:27:43 +0000 | [diff] [blame] | 184 | /* Open tty */ |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 185 | handle = open(*argv, O_RDWR | O_NDELAY); |
| 186 | if (handle < 0) { |
Denis Vlasenko | 8333587 | 2007-06-21 07:27:43 +0000 | [diff] [blame] | 187 | char *buf = concat_path_file("/dev", *argv); |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 188 | 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 Vlasenko | 8333587 | 2007-06-21 07:27:43 +0000 | [diff] [blame] | 196 | /* Configure tty */ |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 197 | 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 Vlasenko | 8333587 | 2007-06-21 07:27:43 +0000 | [diff] [blame] | 221 | * until we are killed */ |
Denis Vlasenko | 14923db | 2007-06-20 15:23:03 +0000 | [diff] [blame] | 222 | 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 | } |