From 2262746e2b798361a9c293e02f76cb4f06b7b100 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sun, 6 Aug 2017 17:14:09 +0200 Subject: 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 --- NOFORK_NOEXEC.lst | 6 +- libbb/xfuncs.c | 2 +- networking/slattach.c | 167 +++++++++++++++++++------------------------------- 3 files changed, 68 insertions(+), 107 deletions(-) diff --git a/NOFORK_NOEXEC.lst b/NOFORK_NOEXEC.lst index 9b33afc32..3bd82aa60 100644 --- a/NOFORK_NOEXEC.lst +++ b/NOFORK_NOEXEC.lst @@ -78,7 +78,7 @@ conspy - interactive, longterm cp - noexec. runner cpio - runner crond - daemon -crontab 0 leaks: open+xasprintf +crontab - longterm (runs $EDITOR), leaks: open+xasprintf cryptpw - noexec. changes state: with --password-fd=N, moves N to stdin cttyhack - noexec. spawner cut - noexec. runner @@ -311,7 +311,7 @@ setkeycodes setlogcons setpriv - spawner, changes state, let's play safe and not be noexec setserial -setsid - spawner, uses fork_or_rexec() [not audted to work in noexec], let's play safe and not be noexec +setsid - spawner, uses fork_or_rexec() [not audited to work in noexec], let's play safe and not be noexec setuidgid - noexec. spawner sha1sum - noexec. runner sha256sum - noexec. runner @@ -320,7 +320,7 @@ sha512sum - noexec. runner showkey - interactive, longterm shred - runner shuf - noexec. runner -slattach +slattach - longterm (may sleep forever), uses bb_common_bufsiz1 sleep - runner, longterm smemcap - runner softlimit - noexec. spawner diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c index 98d3531d6..1b3a1667b 100644 --- a/libbb/xfuncs.c +++ b/libbb/xfuncs.c @@ -313,7 +313,7 @@ int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp) int FAST_FUNC set_termios_to_raw(int fd, struct termios *oldterm, int flags) { -//TODO: lineedit, microcom and less might be adapted to use this too: +//TODO: lineedit, microcom, slattach, less might be adapted to use this too: // grep for "tcsetattr" struct termios newterm; diff --git a/networking/slattach.c b/networking/slattach.c index 71b5bf427..d4659a314 100644 --- a/networking/slattach.c +++ b/networking/slattach.c @@ -17,23 +17,23 @@ //config: default y //config: select PLATFORM_LINUX //config: help -//config: slattach is a small utility to attach network interfaces to serial -//config: lines. +//config: slattach configures serial line as SLIP network interface. //applet:IF_SLATTACH(APPLET(slattach, BB_DIR_SBIN, BB_SUID_DROP)) +/* shouldn't be NOEXEC: may sleep indefinitely */ //kbuild:lib-$(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 @@ int slattach_main(int argc UNUSED_PARAM, char **argv) "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 @@ int slattach_main(int argc UNUSED_PARAM, char **argv) 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 @@ int slattach_main(int argc UNUSED_PARAM, char **argv) 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 @@ int slattach_main(int argc UNUSED_PARAM, char **argv) , 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 @@ int slattach_main(int argc UNUSED_PARAM, char **argv) /* 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); } -- cgit v1.2.3