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path: root/release/src/router/busybox/networking/slattach.c
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-rw-r--r--release/src/router/busybox/networking/slattach.c245
1 files changed, 245 insertions, 0 deletions
diff --git a/release/src/router/busybox/networking/slattach.c b/release/src/router/busybox/networking/slattach.c
new file mode 100644
index 00000000..d3212bb4
--- /dev/null
+++ b/release/src/router/busybox/networking/slattach.c
@@ -0,0 +1,245 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Stripped down version of net-tools for busybox.
+ *
+ * Author: Ignacio Garcia Perez (iggarpe at gmail dot com)
+ *
+ * License: GPLv2 or later, see LICENSE file in this tarball.
+ *
+ * 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.
+ */
+
+#include "libbb.h"
+#include "libiproute/utils.h" /* invarg() */
+
+struct globals {
+ int handle;
+ int saved_disc;
+ struct termios saved_state;
+};
+#define G (*(struct globals*)&bb_common_bufsiz1)
+#define handle (G.handle )
+#define saved_disc (G.saved_disc )
+#define saved_state (G.saved_state )
+#define INIT_G() do { } while (0)
+
+
+/*
+ * Save tty state and line discipline
+ *
+ * It is fine here to bail out on errors, since we haven modified anything yet
+ */
+static void save_state(void)
+{
+ /* Save line status */
+ if (tcgetattr(handle, &saved_state) < 0)
+ bb_perror_msg_and_die("get state");
+
+ /* Save line discipline */
+ xioctl(handle, TIOCGETD, &saved_disc);
+}
+
+static int set_termios_state_or_warn(struct termios *state)
+{
+ int ret;
+
+ ret = tcsetattr(handle, TCSANOW, state);
+ if (ret < 0) {
+ bb_perror_msg("set state");
+ return 1; /* used as exitcode */
+ }
+ return 0;
+}
+
+/*
+ * Restore state and line discipline for ALL managed ttys
+ *
+ * Restoring ALL managed ttys is the only way to have a single
+ * hangup delay.
+ *
+ * Go on after errors: we want to restore as many controlled ttys
+ * as possible.
+ */
+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(handle, TIOCSETD, &saved_disc) < 0) {
+ exitcode = 1;
+ }
+
+ /* Hangup */
+ memcpy(&state, &saved_state, sizeof(state));
+ cfsetispeed(&state, B0);
+ cfsetospeed(&state, B0);
+ if (set_termios_state_or_warn(&state))
+ exitcode = 1;
+ sleep(1);
+
+ /* Restore line status */
+ if (set_termios_state_or_warn(&saved_state))
+ exit(EXIT_FAILURE);
+ if (ENABLE_FEATURE_CLEAN_UP)
+ close(handle);
+
+ exit(exitcode);
+}
+
+/*
+ * Set tty state, line discipline and encapsulation
+ */
+static void set_state(struct termios *state, int encap)
+{
+ int disc;
+
+ /* Set line status */
+ if (set_termios_state_or_warn(state))
+ goto bad;
+ /* Set line discliple (N_SLIP always) */
+ disc = N_SLIP;
+ if (ioctl_or_warn(handle, TIOCSETD, &disc) < 0) {
+ goto bad;
+ }
+
+ /* Set encapsulation (SLIP, CSLIP, etc) */
+ if (ioctl_or_warn(handle, SIOCSIFENCAP, &encap) < 0) {
+ bad:
+ restore_state_and_exit(EXIT_FAILURE);
+ }
+}
+
+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 */
+ ;
+
+ int i, encap, opt;
+ struct termios state;
+ const char *proto = "cslip";
+ const char *extcmd; /* Command to execute after hangup */
+ const char *baud_str;
+ int baud_code = -1; /* Line baud rate (system code) */
+
+ 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", &proto, &baud_str, &extcmd);
+ /*argc -= optind;*/
+ argv += optind;
+
+ if (!*argv)
+ bb_show_usage();
+
+ encap = index_in_strings(proto_names, proto);
+
+ if (encap < 0)
+ invarg(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(baud_str, "baud rate");
+ }
+
+ /* 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);
+ }
+
+ /* Open tty */
+ handle = open(*argv, O_RDWR | O_NDELAY);
+ if (handle < 0) {
+ char *buf = concat_path_file("/dev", *argv);
+ handle = xopen(buf, O_RDWR | O_NDELAY);
+ /* maybe if (ENABLE_FEATURE_CLEAN_UP) ?? */
+ free(buf);
+ }
+
+ /* Save current tty state */
+ save_state();
+
+ /* Configure tty */
+ memcpy(&state, &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(&saved_state));
+ cfsetospeed(&state, cfgetospeed(&saved_state));
+ }
+
+ if (opt & OPT_s_baud) {
+ cfsetispeed(&state, baud_code);
+ cfsetospeed(&state, baud_code);
+ }
+
+ set_state(&state, encap);
+
+ /* Exit now if option -e was passed */
+ if (opt & OPT_e_quit)
+ return 0;
+
+ /* 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) {
+ if (ioctl(handle, TIOCMGET, &i) < 0 || !(i & TIOCM_CAR))
+ goto no_carrier;
+ sleep(15);
+ }
+
+ no_carrier:
+
+ /* Execute command on hangup */
+ if (opt & OPT_c_extcmd)
+ system(extcmd);
+
+ /* Restore states and exit */
+ restore_state_and_exit(EXIT_SUCCESS);
+}