# HG changeset patch # User Rob Landley # Date 1375594287 18000 # Node ID 69adf14d70e167e403060f951dcb0c997d215e76 # Parent 32644e4439bda8b59b39f764d8382f8deb9e1844 System V style init, submitted by Kyungwan Han. diff -r 32644e4439bd -r 69adf14d70e1 toys/pending/init.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/toys/pending/init.c Sun Aug 04 00:31:27 2013 -0500 @@ -0,0 +1,470 @@ +/* init.c - init program. + * + * Copyright 2012 Harvind Singh + * Copyright 2013 Kyungwan Han + * + * No Standard + +USE_INIT(NEWTOY(init, "", TOYFLAG_SBIN)) + +config INIT + bool "init" + default n + help + usage: init + + init the system. +*/ + +#include "toys.h" +#include +#include + +struct action_list_seed { + struct action_list_seed *next; + pid_t pid; + uint8_t action; + char *terminal_name; + char *command; +}; +struct action_list_seed *action_list_pointer = NULL; +int caught_signal; + +//INITTAB action defination +#define SYSINIT 0x01 +#define WAIT 0x02 +#define ONCE 0x04 +#define RESPAWN 0x08 +#define ASKFIRST 0x10 +#define CTRLALTDEL 0x20 +#define SHUTDOWN 0x40 +#define RESTART 0x80 + +static void initialize_console(void) +{ + int fd; + char *p = (p = getenv("CONSOLE")) ? p : getenv("console"); + if (!p) { + fd = open("/dev/null", O_RDWR); + if (fd >= 0) { + while(fd < 2) fd = dup(fd); + while(fd > 2) close(fd--); + } + } else { + fd = open(p, O_RDWR | O_NONBLOCK | O_NOCTTY); + if (fd < 0) xprintf("Unable to open console %s\n",p); + else { + dup2(fd,0); + dup2(fd,1); + dup2(fd,2); + } + } + p = getenv("TERM"); +#ifdef VT_OPENQRY + int terminal_no; + if (ioctl(0, VT_OPENQRY, &terminal_no)) { + if (!p || !strcmp(p,"linux")) putenv((char*)"TERM=vt102"); + } else +#endif + if (!p) putenv((char*)"TERM=linux"); +} + +static void set_sane_term(void) +{ + struct termios terminal; + tcgetattr(0, &terminal); + terminal.c_cc[VINTR] = 3;//ctrl-c + terminal.c_cc[VQUIT] = 28;/*ctrl-\*/ + terminal.c_cc[VERASE] = 127;//ctrl-? + terminal.c_cc[VKILL] = 21;//ctrl-u + terminal.c_cc[VEOF] = 4;//ctrl-d + terminal.c_cc[VSTART] = 17;//ctrl-q + terminal.c_cc[VSTOP] = 19;//ctrl-s + terminal.c_cc[VSUSP] = 26;//ctrl-z + + terminal.c_line = 0; + terminal.c_cflag = terminal.c_cflag&(CRTSCTS|PARODD|PARENB|CSTOPB|CSIZE|CBAUDEX|CBAUD); + terminal.c_cflag = terminal.c_cflag|(CLOCAL|HUPCL|CREAD); + terminal.c_iflag = IXON|IXOFF|ICRNL;//enable start/stop input and output control + map CR to NL on input + terminal.c_oflag = ONLCR|OPOST;//Map NL to CR-NL on output + terminal.c_lflag = IEXTEN|ECHOKE|ECHOCTL|ECHOK|ECHOE|ECHO|ICANON|ISIG; + tcsetattr(0, TCSANOW, &terminal); +} + +static void set_enviornment(void) +{ + putenv((char*)"HOME=/"); + putenv((char*)"PATH=/sbin:/usr/sbin:/bin:/usr/bin"); + putenv((char*)"SHELL=/bin/sh"); + putenv((char*)"USER=root"); +} + +static void add_new_action(uint8_t action,char *command,char *term) +{ + struct action_list_seed *x,**y; + y = &action_list_pointer; + x = *y; + while(x) { + if (!(strcmp(x->command,command)) && !(strcmp(x->terminal_name,term))) { + *y = x->next;//remove from the list + while(*y) y = &(*y)->next;//traverse through list till end + x->next = NULL; + break; + } + y = &(x)->next; + x = *y; + } + //create a new node + if (!x) { + x = xzalloc(sizeof(*x)); + x->command = xstrdup(command); + x->terminal_name = xstrdup(term); + } + x->action = action; + *y = x; +} + +static void inittab_parsing(void) +{ + int i, fd, line_number = 0, token_count = 0; + char *p, *q, *extracted_token, *tty_name = NULL, *command = NULL, *tmp; + uint8_t action = 0; + char *act_name = "sysinit\0wait\0once\0respawn\0askfirst\0ctrlaltdel\0" + "shutdown\0restart\0"; + + fd = open("/etc/inittab", O_RDONLY); + if (fd < 0) { + error_msg("Unable to open /etc/inittab. Using Default inittab"); + add_new_action(SYSINIT, "/etc/init.d/rcS", ""); + add_new_action(RESPAWN, "/sbin/getty -n -l /bin/sh -L 115200 tty1 vt100", ""); + } else { + while((q = p = get_line(fd))) { //read single line from /etc/inittab + char *x; + if((x = strchr(p, '#'))) *x = '\0'; + line_number++; + token_count = 0; + action = 0; + while((extracted_token = strsep(&p,":"))) { + token_count++; + switch (token_count) { + case 1: + if (*extracted_token) { + if(!strncmp(extracted_token, "/dev/", 5)) + tty_name = xmsprintf("%s",extracted_token); + else tty_name = xmsprintf("/dev/%s",extracted_token); + } else tty_name = xstrdup(""); + break; + case 2: + break; + case 3: + for(tmp = act_name, i = 0; *tmp; i++, tmp += strlen(tmp) +1) { + if ( !strcmp(tmp, extracted_token)) { + action = 1 << i; + break; + } + } + if (!*tmp) error_msg("Invalid action at line number %d ---- ignoring",line_number); + break; + case 4: + command = xstrdup(extracted_token); + break; + default: + error_msg("Bad inittab entry at line %d", line_number); + break; + } + } //while token + if (q) free(q); + if (token_count != 4) continue; + if (action) add_new_action(action, command, tty_name); + free(tty_name); + free(command); + }//while line + close(fd); + } +} + +static void run_command(char *command) +{ + char *final_command[128]; + int hyphen = (command[0]=='-'); + + command = command + hyphen; + if (!strpbrk(command, "?<>'\";[]{}\\|=()*&^$!`~")) { + char *next_command; + char *extracted_command; + int x = 0; + next_command = strncpy(toybuf, command - hyphen, sizeof(toybuf)); + next_command[sizeof(toybuf) - 1] = toybuf[sizeof(toybuf) - 1 ] = '\0'; + command = next_command + hyphen; + while((extracted_command = strsep(&next_command," \t"))) { + if (*extracted_command) { + final_command[x] = extracted_command; + x++; + } + } + final_command[x] = NULL; + } else { + snprintf(toybuf, sizeof(toybuf), "exec %s", command); + command = "-/bin/sh"+1; + final_command[0] = (char*)("-/bin/sh"+!hyphen); + final_command[1] = (char*)"-c"; + final_command[2] = toybuf; + final_command[3] = NULL; + } + if (hyphen) ioctl(0, TIOCSCTTY, 0); + execvp(command, final_command); + error_msg("unable to run %s",command); +} + +//runs all same type of actions +static pid_t final_run(struct action_list_seed *x) +{ + pid_t pid; + int fd; + sigset_t signal_set; + + sigfillset(&signal_set); + sigprocmask(SIG_BLOCK, &signal_set, NULL); + if (x->action & ASKFIRST) pid = fork(); + else pid = vfork(); + if (pid > 0) { + //parent process or error + //unblock the signals + sigfillset(&signal_set); + sigprocmask(SIG_UNBLOCK, &signal_set, NULL); + return pid; + } else if (pid < 0) perror_exit("fork fail"); + //new born child process + sigset_t signal_set_c; + sigfillset(&signal_set_c); + sigprocmask(SIG_UNBLOCK, &signal_set_c, NULL); + setsid();//new session + if (x->terminal_name[0]) { + close(0); + fd = open(x->terminal_name,(O_RDWR|O_NONBLOCK),0600); + if (fd != 0) { + error_msg("Unable to open %s,%s\n",x->terminal_name,strerror(errno)); + _exit(EXIT_FAILURE); + } else { + dup2(0,1); + dup2(0,2); + } + } + set_sane_term(); + run_command(x->command); + _exit(-1); +} + +static struct action_list_seed* mark_as_terminated_process(pid_t pid) +{ + struct action_list_seed *x; + if (pid > 0) { + for (x = action_list_pointer; x; x = x->next) { + if (x->pid == pid) { + x->pid = 0; + return x; + } + } + } + return NULL; +} + +static void waitforpid(pid_t pid) +{ + if (pid <= 0) return; + for(;;) { + pid_t y = wait(NULL); + mark_as_terminated_process(y); + if (kill(y,0)) break; + } +} +static void run_action_from_list(int action) +{ + pid_t pid; + struct action_list_seed *x = action_list_pointer; + for (; x; x = x->next) { + if (!(x->action & action)) continue; + if (x->action & (SHUTDOWN|ONCE|SYSINIT|CTRLALTDEL|WAIT)) { + pid = final_run(x); + if (x->action & (SHUTDOWN|SYSINIT|CTRLALTDEL|WAIT)) waitforpid(pid); + } + if (x->action & (ASKFIRST|RESPAWN)) + if (!(x->pid)) x->pid = final_run(x); + } +} + +static void set_defualt(void) +{ + sigset_t signal_set_c; + + signal(SIGUSR1,SIG_DFL); + signal(SIGUSR2,SIG_DFL); + signal(SIGTERM,SIG_DFL); + signal(SIGQUIT,SIG_DFL); + signal(SIGINT,SIG_DFL); + signal(SIGHUP,SIG_DFL); + signal(SIGTSTP,SIG_DFL); + signal(SIGSTOP,SIG_DFL); + sigfillset(&signal_set_c); + sigprocmask(SIG_UNBLOCK,&signal_set_c, NULL); + run_action_from_list(SHUTDOWN); + error_msg("The system is going down NOW!"); + kill(-1, SIGTERM); + error_msg("Sent SIGTERM to all processes"); + sync(); + sleep(1); + kill(-1,SIGKILL); + sync(); +} + +static void halt_poweroff_reboot_handler(int sig_no) +{ + unsigned int reboot_magic_no = 0; + pid_t pid; + set_defualt(); + switch (sig_no) { + case SIGUSR1: + error_msg("Requesting system halt"); + reboot_magic_no=RB_HALT_SYSTEM; + break; + case SIGUSR2: + error_msg("Requesting system poweroff"); + reboot_magic_no=RB_POWER_OFF; + break; + case SIGTERM: + error_msg("Requesting system reboot"); + reboot_magic_no=RB_AUTOBOOT; + break; + default: + break; + } + sleep(1); + pid = vfork(); + if (pid == 0) { + reboot(reboot_magic_no); + _exit(EXIT_SUCCESS); + } + while(1) sleep(1); +} +static void restart_init_handler(int sig_no) +{ + struct action_list_seed *x; + pid_t pid; + int fd; + for (x = action_list_pointer; x; x = x->next) { + if (!(x->action & RESTART)) continue; + + set_defualt(); + if (x->terminal_name[0]) { + close(0); + fd = open(x->terminal_name,(O_RDWR|O_NONBLOCK),0600); + if (fd != 0) { + error_msg("Unable to open %s,%s\n",x->terminal_name,strerror(errno)); + sleep(1); + pid = vfork(); + if (pid == 0) { + reboot(RB_HALT_SYSTEM); + _exit(EXIT_SUCCESS); + } + while(1) sleep(1); + } else { + dup2(0,1); + dup2(0,2); + set_sane_term(); + run_command(x->command); + } + } + } +} + +static void catch_signal(int sig_no) +{ + caught_signal = sig_no; + error_msg("signal seen"); +} + +static void pause_handler(int sig_no) +{ + int signal_backup,errno_backup; + pid_t pid; + errno_backup = errno; + signal_backup = caught_signal; + signal(SIGCONT, catch_signal); + while(1) { + if (caught_signal == SIGCONT) break; + do + pid = waitpid(-1,NULL,WNOHANG); + while((pid==-1) && (errno=EINTR)); + mark_as_terminated_process(pid); + sleep(1); + } + signal(SIGCONT,SIG_DFL); + errno = errno_backup; + caught_signal = signal_backup; +} + +static void assign_signal_handler(void) +{ + struct sigaction sig_act; + signal(SIGUSR1, halt_poweroff_reboot_handler);//halt + signal(SIGUSR2, halt_poweroff_reboot_handler);//poweroff + signal(SIGTERM, halt_poweroff_reboot_handler);//reboot + signal(SIGQUIT, restart_init_handler);//restart init + memset(&sig_act, 0, sizeof(sig_act)); + sigfillset(&sig_act.sa_mask); + sigdelset(&sig_act.sa_mask, SIGCONT); + sig_act.sa_handler = pause_handler; + sigaction(SIGTSTP, &sig_act, NULL); + + memset(&sig_act, 0, sizeof(sig_act)); + sig_act.sa_handler = catch_signal; + sigaction(SIGINT, &sig_act, NULL); + sigaction(SIGHUP, &sig_act, NULL); +} + +static int check_if_pending_signals(void) +{ + int signal_caught = 0; + while(1) { + int sig = caught_signal; + if (!sig) return signal_caught; + caught_signal = 0; + signal_caught = 1; + if (sig == SIGINT) run_action_from_list(CTRLALTDEL); + } +} +void init_main(void) +{ + if (getpid() != 1) error_exit("Already running"); + xprintf("Started init\n"); + initialize_console(); + set_sane_term(); + + if (chdir("/")) perror_exit("Can't cd to /"); + setsid(); + + set_enviornment(); + inittab_parsing(); + assign_signal_handler(); + run_action_from_list(SYSINIT); + check_if_pending_signals(); + run_action_from_list(WAIT); + check_if_pending_signals(); + run_action_from_list(ONCE); + while(1) { + int suspected_WNOHANG; + suspected_WNOHANG = check_if_pending_signals(); + run_action_from_list(RESPAWN | ASKFIRST); + suspected_WNOHANG = suspected_WNOHANG|check_if_pending_signals(); + sleep(1);//let cpu breath + suspected_WNOHANG = suspected_WNOHANG|check_if_pending_signals(); + if (suspected_WNOHANG) suspected_WNOHANG=WNOHANG; + while(1) { + pid_t pid; + pid = waitpid(-1, NULL, suspected_WNOHANG); + if (pid <= 0) break; + mark_as_terminated_process(pid); + suspected_WNOHANG = WNOHANG; + } + } +}