From a37e7134f76b7661b86bb9cc926f28f81b1e1109 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Tue, 19 Feb 2008 02:57:07 +0000 Subject: [PATCH] init: fix bug 1111: restart actions were not splitting words: ::restart:/sbin/rc restart resulted in: exec of '/sbin/rc restart' failed: No such file or directory --- init/Config.in | 15 ++-- init/init.c | 189 +++++++++++++++++++++++-------------------------- 2 files changed, 96 insertions(+), 108 deletions(-) diff --git a/init/Config.in b/init/Config.in index 4c5610246..f525abc8a 100644 --- a/init/Config.in +++ b/init/Config.in @@ -47,15 +47,18 @@ config FEATURE_KILL_DELAY wrong process!) config FEATURE_INIT_SCTTY - bool "Support running commands with a controlling-tty" + bool "Run commands with leading dash with controlling tty" default n depends on INIT help - If this option is enabled a command starting with hyphen (-) - is run in its own session (setsid(2)) and possibly with a - controlling tty (TIOCSCTTY). This is not the traditional init - behavour, but is often what you want in an embedded system where - the console is only accessed during development or for maintenance. + If this option is enabled, init will try to give a controlling + tty to any command which has leading hyphen (often it's "-/bin/sh"). + More precisely, init will do "ioctl(STDIN_FILENO, TIOCSCTTY, 0)". + If device attached to STDIN_FILENO can be a ctty but is not yet + a ctty for other session, it will become this process' ctty. + This is not the traditional init behavour, but is often what you want + in an embedded system where the console is only accessed during + development or for maintenance. NB: using cttyhack applet may work better. config FEATURE_INIT_SYSLOG diff --git a/init/init.c b/init/init.c index 080c5b3af..8d706fe1f 100644 --- a/init/init.c +++ b/init/init.c @@ -14,7 +14,7 @@ #include #include -#define INIT_BUFFS_SIZE 256 +#define COMMAND_SIZE 256 #define CONSOLE_NAME_SIZE 32 #define MAXENV 16 /* Number of env. vars */ @@ -55,9 +55,9 @@ struct init_action { struct init_action *next; pid_t pid; - uint8_t action; + uint8_t action_type; char terminal[CONSOLE_NAME_SIZE]; - char command[INIT_BUFFS_SIZE]; + char command[COMMAND_SIZE]; }; /* Static variables */ @@ -294,14 +294,57 @@ static void open_stdio_to_tty(const char* tty_name, int exit_on_failure) set_sane_term(); } +/* wrapper around exec: + * takes string (max COMMAND_SIZE chars) + * runs [-]/bin/sh -c "exec ......." if '>' etc detected. + * otherwise splits words on whitespace and deals with leading dash. + */ +static void init_exec(const char *command) +{ + char *cmd[COMMAND_SIZE / 2]; + char buf[COMMAND_SIZE + 6]; /* COMMAND_SIZE+strlen("exec ")+1 */ + int dash = (command[0] == '-'); + + /* See if any special /bin/sh requiring characters are present */ + if (strpbrk(command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) { + strcpy(buf, "exec "); + strcpy(buf + 5, command + dash); /* excluding "-" */ + /* LIBBB_DEFAULT_LOGIN_SHELL has leading dash */ + cmd[0] = (char*)(LIBBB_DEFAULT_LOGIN_SHELL + !dash); + cmd[1] = (char*)"-c"; + cmd[2] = buf; + cmd[3] = NULL; + } else { + /* Convert command (char*) into cmd (char**, one word per string) */ + char *word, *next; + int i = 0; + next = strcpy(buf, command); /* including "-" */ + while ((word = strsep(&next, " \t")) != NULL) { + if (*word != '\0') { /* not two spaces/tabs together? */ + cmd[i] = word; + i++; + } + } + cmd[i] = NULL; + } + /* If we saw leading "-", it is interactive shell. + * Try harder to give it a controlling tty. + * And skip "-" in actual exec call. */ + if (dash) { + /* _Attempt_ to make stdin a controlling tty. */ + if (ENABLE_FEATURE_INIT_SCTTY) + ioctl(STDIN_FILENO, TIOCSCTTY, 0 /*only try, don't steal*/); + } + BB_EXECVP(cmd[0] + dash, cmd); + message(L_LOG | L_CONSOLE, "Cannot run '%s': %s", + cmd[0], strerror(errno)); + /* returns if execvp fails */ +} + /* Used only by run_actions */ static pid_t run(const struct init_action *a) { - int i; pid_t pid; - char *s, *tmpCmd, *cmdpath; - char *cmd[INIT_BUFFS_SIZE]; - char buf[INIT_BUFFS_SIZE + 6]; /* INIT_BUFFS_SIZE+strlen("exec ")+1 */ sigset_t nmask, omask; /* Block sigchild while forking (why?) */ @@ -341,7 +384,7 @@ static pid_t run(const struct init_action *a) #ifdef BUT_RUN_ACTIONS_ALREADY_DOES_WAITING /* If the init Action requires us to wait, then force the * supplied terminal to be the controlling tty. */ - if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) { + if (a->action_type & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) { /* Now fork off another process to just hang around */ pid = fork(); if (pid < 0) { @@ -381,58 +424,7 @@ static pid_t run(const struct init_action *a) /* Child - fall though to actually execute things */ } #endif - - /* See if any special /bin/sh requiring characters are present */ - if (strpbrk(a->command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) { - cmd[0] = (char*)DEFAULT_SHELL; - cmd[1] = (char*)"-c"; - cmd[2] = strcat(strcpy(buf, "exec "), a->command); - cmd[3] = NULL; - } else { - /* Convert command (char*) into cmd (char**, one word per string) */ - strcpy(buf, a->command); - s = buf; - for (tmpCmd = buf, i = 0; (tmpCmd = strsep(&s, " \t")) != NULL;) { - if (*tmpCmd != '\0') { - cmd[i] = tmpCmd; - i++; - } - } - cmd[i] = NULL; - } - - cmdpath = cmd[0]; - - /* - * Interactive shells want to see a dash in argv[0]. This - * typically is handled by login, argv will be setup this - * way if a dash appears at the front of the command path - * (like "-/bin/sh"). - */ - if (*cmdpath == '-') { - /* skip over the dash */ - ++cmdpath; - -#ifdef WHY_WE_DO_THIS_SHELL_MUST_HANDLE_THIS_ITSELF - /* find the last component in the command pathname */ - s = bb_get_last_path_component_nostrip(cmdpath); - /* make a new argv[0] */ - cmd[0] = malloc(strlen(s) + 2); - if (cmd[0] == NULL) { - message(L_LOG | L_CONSOLE, bb_msg_memory_exhausted); - cmd[0] = cmdpath; - } else { - cmd[0][0] = '-'; - strcpy(cmd[0] + 1, s); - } -#endif - - /* _Attempt_ to make stdin a controlling tty. */ - if (ENABLE_FEATURE_INIT_SCTTY) - ioctl(0, TIOCSCTTY, 0 /*only try, don't steal*/); - } - - if (a->action & ASKFIRST) { + if (a->action_type & ASKFIRST) { static const char press_enter[] ALIGN1 = #ifdef CUSTOMIZED_BANNER #include CUSTOMIZED_BANNER @@ -449,58 +441,54 @@ static pid_t run(const struct init_action *a) */ messageD(L_LOG, "waiting for enter to start '%s'" "(pid %d, tty '%s')\n", - cmdpath, getpid(), a->terminal); + a->command, getpid(), a->terminal); full_write(1, press_enter, sizeof(press_enter) - 1); while (safe_read(0, &c, 1) == 1 && c != '\n') continue; } - /* Log the process name and args */ - message(L_LOG, "starting pid %d, tty '%s': '%s'", - getpid(), a->terminal, cmdpath); - if (ENABLE_FEATURE_INIT_COREDUMPS) { struct stat sb; if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) { struct rlimit limit; - limit.rlim_cur = RLIM_INFINITY; limit.rlim_max = RLIM_INFINITY; setrlimit(RLIMIT_CORE, &limit); } } + /* Log the process name and args */ + message(L_LOG, "starting pid %d, tty '%s': '%s'", + getpid(), a->terminal, a->command); + /* Now run it. The new program will take over this PID, * so nothing further in init.c should be run. */ - BB_EXECVP(cmdpath, cmd); - + init_exec(a->command); /* We're still here? Some error happened. */ - message(L_LOG | L_CONSOLE, "Cannot run '%s': %s", - cmdpath, strerror(errno)); _exit(-1); } /* Run all commands of a particular type */ -static void run_actions(int action) +static void run_actions(int action_type) { struct init_action *a, *tmp; for (a = init_action_list; a; a = tmp) { tmp = a->next; - if (a->action == action) { + if (a->action_type == action_type) { // Pointless: run() will error out if open of device fails. ///* a->terminal of "" means "init's console" */ //if (a->terminal[0] && access(a->terminal, R_OK | W_OK)) { // //message(L_LOG | L_CONSOLE, "Device %s cannot be opened in RW mode", a->terminal /*, strerror(errno)*/); // delete_init_action(a); //} else - if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) { + if (a->action_type & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) { waitfor(run(a)); delete_init_action(a); - } else if (a->action & ONCE) { + } else if (a->action_type & ONCE) { run(a); delete_init_action(a); - } else if (a->action & (RESPAWN | ASKFIRST)) { + } else if (a->action_type & (RESPAWN | ASKFIRST)) { /* Only run stuff with pid==0. If they have * a pid, that means it is still running */ if (a->pid == 0) { @@ -593,12 +581,11 @@ static void halt_reboot_pwoff(int sig) * else (no such action defined) do nothing */ static void exec_restart_action(int sig ATTRIBUTE_UNUSED) { - struct init_action *a, *tmp; + struct init_action *a; sigset_t unblock_signals; - for (a = init_action_list; a; a = tmp) { - tmp = a->next; - if (a->action & RESTART) { + for (a = init_action_list; a; a = a->next) { + if (a->action_type & RESTART) { kill_all_processes(); /* unblock all signals (blocked in kill_all_processes()) */ @@ -620,10 +607,7 @@ static void exec_restart_action(int sig ATTRIBUTE_UNUSED) open_stdio_to_tty(a->terminal, 0 /* - halt if open fails */); messageD(L_CONSOLE | L_LOG, "Trying to re-exec %s", a->command); - BB_EXECLP(a->command, a->command, NULL); - - message(L_CONSOLE | L_LOG, "Cannot run '%s': %s", - a->command, strerror(errno)); + init_exec(a->command); sleep(2); init_reboot(RB_HALT_SYSTEM); loop_forever(); @@ -654,12 +638,13 @@ static void cont_handler(int sig ATTRIBUTE_UNUSED) got_cont = 1; } -static void new_init_action(uint8_t action, const char *command, const char *cons) +static void new_init_action(uint8_t action_type, const char *command, const char *cons) { - struct init_action *new_action, *a, *last; + struct init_action *a, *last; - if (strcmp(cons, bb_dev_null) == 0 && (action & ASKFIRST)) - return; +// Why? +// if (strcmp(cons, bb_dev_null) == 0 && (action & ASKFIRST)) +// return; /* Append to the end of the list */ for (a = last = init_action_list; a; a = a->next) { @@ -668,23 +653,23 @@ static void new_init_action(uint8_t action, const char *command, const char *con if ((strcmp(a->command, command) == 0) && (strcmp(a->terminal, cons) == 0) ) { - a->action = action; + a->action_type = action_type; return; } last = a; } - new_action = xzalloc(sizeof(struct init_action)); + a = xzalloc(sizeof(*a)); if (last) { - last->next = new_action; + last->next = a; } else { - init_action_list = new_action; + init_action_list = a; } - strcpy(new_action->command, command); - new_action->action = action; - strcpy(new_action->terminal, cons); + a->action_type = action_type; + safe_strncpy(a->command, command, sizeof(a->command)); + safe_strncpy(a->terminal, cons, sizeof(a->terminal)); messageD(L_LOG | L_CONSOLE, "command='%s' action=%d tty='%s'\n", - new_action->command, new_action->action, new_action->terminal); + a->command, a->action_type, a->terminal); } static void delete_init_action(struct init_action *action) @@ -714,7 +699,7 @@ static void delete_init_action(struct init_action *action) static void parse_inittab(void) { FILE *file; - char buf[INIT_BUFFS_SIZE]; + char buf[COMMAND_SIZE]; if (ENABLE_FEATURE_USE_INITTAB) file = fopen(INITTAB, "r"); @@ -743,7 +728,7 @@ static void parse_inittab(void) return; } - while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) { + while (fgets(buf, COMMAND_SIZE, file) != NULL) { static const char actions[] = STR_SYSINIT "sysinit\0" STR_RESPAWN "respawn\0" @@ -810,7 +795,7 @@ static void reload_signal(int sig ATTRIBUTE_UNUSED) /* disable old entrys */ for (a = init_action_list; a; a = a->next) { - a->action = ONCE; + a->action_type = ONCE; } parse_inittab(); @@ -819,7 +804,7 @@ static void reload_signal(int sig ATTRIBUTE_UNUSED) /* Be nice and send SIGTERM first */ for (a = init_action_list; a; a = a->next) { pid_t pid = a->pid; - if ((a->action & ONCE) && pid != 0) { + if ((a->action_type & ONCE) && pid != 0) { kill(pid, SIGTERM); } } @@ -828,7 +813,7 @@ static void reload_signal(int sig ATTRIBUTE_UNUSED) sleep(CONFIG_FEATURE_KILL_DELAY); for (a = init_action_list; a; a = a->next) { pid_t pid = a->pid; - if ((a->action & ONCE) && pid != 0) { + if ((a->action_type & ONCE) && pid != 0) { kill(pid, SIGKILL); } } @@ -840,7 +825,7 @@ static void reload_signal(int sig ATTRIBUTE_UNUSED) /* remove unused entrys */ for (a = init_action_list; a; a = tmp) { tmp = a->next; - if ((a->action & (ONCE | SYSINIT | WAIT)) && a->pid == 0) { + if ((a->action_type & (ONCE | SYSINIT | WAIT)) && a->pid == 0) { delete_init_action(a); } } @@ -998,7 +983,7 @@ int init_main(int argc, char **argv) * restarted by run_actions() */ a->pid = 0; message(L_LOG, "process '%s' (pid %d) exited. " - "Scheduling it for restart.", + "Scheduling for restart.", a->command, wpid); } }