slattach: code shrink, better --help text
function old new delta
tcsetattr_serial_or_warn - 34 +34
static.int_N_SLIP - 4 +4
restore_state_and_exit 123 117 -6
packed_usage 31774 31747 -27
set_termios_state_or_warn 42 - -42
slattach_main 673 624 -49
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 0/3 up/down: 38/-124) Total: -86 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/NOFORK_NOEXEC.lst b/NOFORK_NOEXEC.lst
index 9b33afc..3bd82aa 100644
--- a/NOFORK_NOEXEC.lst
+++ b/NOFORK_NOEXEC.lst
@@ -78,7 +78,7 @@
cp - noexec. runner
cpio - runner
crond - daemon
-crontab 0 leaks: open+xasprintf
+crontab - longterm (runs $EDITOR), leaks: open+xasprintf
cryptpw - noexec. changes state: with --password-fd=N, moves N to stdin
cttyhack - noexec. spawner
cut - noexec. runner
@@ -311,7 +311,7 @@
setlogcons
setpriv - spawner, changes state, let's play safe and not be noexec
setserial
-setsid - spawner, uses fork_or_rexec() [not audted to work in noexec], let's play safe and not be noexec
+setsid - spawner, uses fork_or_rexec() [not audited to work in noexec], let's play safe and not be noexec
setuidgid - noexec. spawner
sha1sum - noexec. runner
sha256sum - noexec. runner
@@ -320,7 +320,7 @@
showkey - interactive, longterm
shred - runner
shuf - noexec. runner
-slattach
+slattach - longterm (may sleep forever), uses bb_common_bufsiz1
sleep - runner, longterm
smemcap - runner
softlimit - noexec. spawner
diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index 98d3531..1b3a166 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -313,7 +313,7 @@
int FAST_FUNC set_termios_to_raw(int fd, struct termios *oldterm, int flags)
{
-//TODO: lineedit, microcom and less might be adapted to use this too:
+//TODO: lineedit, microcom, slattach, less might be adapted to use this too:
// grep for "tcsetattr"
struct termios newterm;
diff --git a/networking/slattach.c b/networking/slattach.c
index 71b5bf4..d4659a3 100644
--- a/networking/slattach.c
+++ b/networking/slattach.c
@@ -17,23 +17,23 @@
//config: default y
//config: select PLATFORM_LINUX
//config: help
-//config: slattach is a small utility to attach network interfaces to serial
-//config: lines.
+//config: slattach configures serial line as SLIP network interface.
//applet:IF_SLATTACH(APPLET(slattach, BB_DIR_SBIN, BB_SUID_DROP))
+/* shouldn't be NOEXEC: may sleep indefinitely */
//kbuild:lib-$(CONFIG_SLATTACH) += slattach.o
//usage:#define slattach_trivial_usage
-//usage: "[-cehmLF] [-s SPEED] [-p PROTOCOL] DEVICE"
+//usage: "[-ehmLF] [-c SCRIPT] [-s BAUD] [-p PROTOCOL] SERIAL_DEVICE"
//usage:#define slattach_full_usage "\n\n"
-//usage: "Attach network interface(s) to serial line(s)\n"
-//usage: "\n -p PROT Set protocol (slip, cslip, slip6, clisp6 or adaptive)"
-//usage: "\n -s SPD Set line speed"
-//usage: "\n -e Exit after initializing device"
-//usage: "\n -h Exit when the carrier is lost"
-//usage: "\n -c PROG Run PROG when the line is hung up"
-//usage: "\n -m Do NOT initialize the line in raw 8 bits mode"
+//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"
@@ -42,103 +42,53 @@
#include "libiproute/utils.h" /* invarg_1_to_2() */
struct globals {
- int handle;
int saved_disc;
struct termios saved_state;
} FIX_ALIASING;
#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 { setup_common_bufsiz(); } while (0)
+#define serial_fd 3
-/*
- * 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)
+static int tcsetattr_serial_or_warn(struct termios *state)
{
int ret;
- ret = tcsetattr(handle, TCSANOW, state);
- if (ret < 0) {
- bb_perror_msg("set state");
+ ret = tcsetattr(serial_fd, TCSANOW, state);
+ if (ret != 0) {
+ bb_perror_msg("tcsetattr");
return 1; /* used as exitcode */
}
- return 0;
+ return ret; /* 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) {
+ if (ioctl_or_warn(serial_fd, TIOCSETD, &G.saved_disc)) {
exitcode = 1;
}
/* Hangup */
- memcpy(&state, &saved_state, sizeof(state));
+ memcpy(&state, &G.saved_state, sizeof(state));
cfsetispeed(&state, B0);
cfsetospeed(&state, B0);
- if (set_termios_state_or_warn(&state))
- exitcode = 1;
+ exitcode |= tcsetattr_serial_or_warn(&state);
sleep(1);
/* Restore line status */
- if (set_termios_state_or_warn(&saved_state))
+ if (tcsetattr_serial_or_warn(&G.saved_state))
exit(EXIT_FAILURE);
+
if (ENABLE_FEATURE_CLEAN_UP)
- close(handle);
+ close(serial_fd);
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);
@@ -155,13 +105,14 @@
"cslip6\0" /* 3 */
"adaptive\0" /* 8 */
;
+ static const int int_N_SLIP = N_SLIP;
- int i, encap, opt;
+ 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 = -1; /* Line baud rate (system code) */
+ int baud_code = baud_code; /* for compiler */
enum {
OPT_p_proto = 1 << 0,
@@ -177,15 +128,12 @@
INIT_G();
/* Parse command line options */
+ opt_complementary = "=1";
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_1_to_2(proto, "protocol");
if (encap > 3)
@@ -198,6 +146,22 @@
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_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
@@ -208,43 +172,37 @@
, 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));
+ 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_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));
+ 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_state(&state, encap);
+ /* 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 0;
+ return EXIT_SUCCESS;
/* If we're not requested to watch, just keep descriptor open
* until we are killed */
@@ -254,17 +212,20 @@
/* Watch line for hangup */
while (1) {
- if (ioctl(handle, TIOCMGET, &i) < 0 || !(i & TIOCM_CAR))
- goto no_carrier;
+ int modem_stat;
+ if (ioctl(serial_fd, TIOCMGET, &modem_stat))
+ break;
+ if (!(modem_stat & TIOCM_CAR))
+ break;
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);
+ bad:
+ restore_state_and_exit(EXIT_FAILURE);
}