/*- * Copyright (c) 1998 Andrzej Bialecki * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD$ */ /* * A primitive version of init(8) with simplistic user interface */ #include #include #include #include #include #include #include #include #include #ifdef USE_HISTORY #error "Not yet. But it's quite simple to add - patches are welcome!" #endif #include #include #include #include #include #include #include #include #include #include #include #define BUFSIZE 1024 #define MAX_CONS 12 #define NONE 0 #define SINGLE 1 #define MULTI 2 #define DEATH 3 #define FALSE 0 #define TRUE 1 char cwd[BUFSIZE]; char vty[]="0123456789abcdef"; char *progname; char *motd=NULL; int ncons=MAX_CONS; int Reboot=FALSE; int transition=MULTI; int prevtrans=SINGLE; jmp_buf machine; char *trans[]={ "NONE", "SINGLE", "MULTI", "DEATH" }; extern char **environ; /* Struct for holding session state */ struct sess { char tty[16]; /* vty device path */ pid_t pid; /* pid of process running on it */ int (*func)(int argc, char **argv); /* internal function to run on it (after forking) */ } ttys[MAX_CONS]; /* Struct for built-in command */ struct command { char *cmd; /* command name */ char *descr; /* command description */ char *usage; /* usage */ char *example; /* example of usage */ int (*func)(char *); /* callback function */ }; /* Prototypes */ int cd __P((char *)); int pwd __P((char *)); int echo __P((char *)); int xit __P((char *)); int set __P((char *)); int unset __P((char *)); int env __P((char *)); int help __P((char *)); int sourcer __P((char *)); void do_command __P((int shell, char *cmdline)); void transition_handler __P((int)); /* Table of built-in functions */ struct command bltins[]={ {"cd","Change working directory","cd [dir]","cd /etc",cd}, {"pwd","Print current directory","pwd","pwd",pwd}, {"exit","Exit from shell()","exit","exit",xit}, {"set","Set environment variable","set [VAR=value]","set TERM=cons25",set}, {"unset","Unset environment variable","unset VAR","unset EDITOR",unset}, {"echo","Echo arguments on stdout","echo arg1 arg2 ...","echo Hello World!",echo}, {"env","Print all environment variables","env","env",env}, {".","Source-in a file with commands",". filename",". /etc/rc",sourcer}, {"?","Print this help :-)","? [command]","? set",help}, {NULL,NULL,NULL,NULL,NULL} }; /* * Built-in 'cd ' handler */ int cd(char *path) { if(chdir(path)) return(-1); getcwd(cwd,BUFSIZE); return(0); } /* * Built-in 'pwd' handler */ int pwd(char *dummy) { if(getcwd(cwd,BUFSIZE)==NULL) return(-1); printf("%s\n",cwd); return(0); } /* * Built-in 'exit' handler */ int xit(char *dummy) { _exit(0); } /* * Built-in 'echo' handler */ int echo(char *args) { int i=0,j; int len; char c; int s_quote=0,d_quote=0; int sep=0,no_lf=0; if(args==NULL) { printf("\n"); return; } len=strlen(args); if(len>=2) { if(args[0]=='-' && args[1]=='n') { no_lf++; i=2; while(icmd!=NULL) { printf("%s\t%s\n",x->cmd,x->descr); x++; } printf("\nEnter '? ' for details.\n\n"); return(0); } else { x=bltins; while(x->cmd!=NULL) { if(strcmp(x->cmd,cmd)==0) { found++; break; } x++; } if(found) { printf("\n%s\t%s:\n",x->cmd,x->descr); printf("\tUsage:\n\t\t%s\n",x->usage); printf("\te.g:\n\t\t%s\n\n",x->example); return(0); } else { printf("\n%s: no such command.\n\n",cmd); return(-1); } } } /* * Signal handler for shell() */ void shell_sig(int sig) { switch(sig) { case SIGINT: case SIGQUIT: case SIGTERM: /* ignore ? */ break; default: break; } } /* * Built-in '.' handler (read-in and execute commands from file) */ int sourcer(char *fname) { FILE *fd; char buf[512],*tok,*arg,**av; int ac,len,f,res,i; pid_t pid; char *sep=" \t"; fd=fopen(fname,"r"); if(fd==NULL) { printf("Couldn't open file '%s'\n",fname); return(-1); } while(!feof(fd)) { memset(buf,0,512); if(fgets(buf,512,fd)==NULL) continue; if((*buf=='#') || (*buf=='\n')) continue; len=strlen(buf); buf[len-1]='\0'; if(strncmp(buf,"ncons",5)==0) { tok=strtok(buf,sep); tok=strtok(NULL,sep); ncons=atoi(tok); if((ncons<1)||(ncons>MAX_CONS)) { syslog(LOG_EMERG,"%s: bad ncons value; defaulting to %d\n",fname,MAX_CONS); ncons=MAX_CONS; } continue; } else if(strncmp(buf,"motd",4)==0) { tok=strtok(buf,sep); motd=strdup(strtok(NULL,sep)); continue; } else { do_command(0,buf); } /* Next command, please. */ } fclose(fd); syslog(LOG_EMERG,"Done with %s",fname); } void do_command(int shell, char *cmdline) { char *tok,*c,*sep=" \t"; char **av; struct command *x; int found,len; int ac,i,f,res; int bg=0; pid_t pid; len=strlen(cmdline); if(cmdline[len-1]=='&') { bg++; cmdline[len-1]='\0'; len--; } else bg=0; tok=strtok(cmdline,sep); x=bltins; found=0; while(x->cmd!=NULL) { if(strcmp(x->cmd,tok)==0) { found++; break; } x++; } if(found) { tok=cmdline+strlen(x->cmd)+1; while(*tok && isblank(*tok) && (tok<(cmdline+len))) tok++; if(*tok==NULL) tok=NULL; x->func(tok); return; } ac=0; av=(char **)calloc(((len+1)/2+1),sizeof(char *)); av[ac++]=tok; while((av[ac++]=strtok(NULL,sep))!=NULL) continue; switch((pid=fork())) { case 0: if(shell) { signal(SIGINT,SIG_DFL); signal(SIGQUIT,SIG_DFL); signal(SIGTERM,SIG_DFL); signal(SIGHUP,SIG_DFL); } else { close(0); close(1); close(2); f=open(_PATH_CONSOLE,O_RDWR); dup2(f,0); dup2(f,1); dup2(f,2); if(f>2) close(f); } if(bg) { if(daemon(0,0)) { printf("do_command(%s): failed to run bg: %s\n", av[0],strerror(errno)); _exit(100); } } execvp(av[0],av); /* Something went wrong... */ printf("do_command(%s): %s\n",av[0],strerror(errno)); _exit(100); break; case -1: printf("do_command(): %s\n",strerror(errno)); break; default: while(waitpid(pid,&res,0)!=pid) continue; if(WEXITSTATUS(res)) { printf("do_command(%s): exit code=%d\n", av[0],WEXITSTATUS(res)); } break; } free(av); return; } /* * This is the user interface. This routine gets executed on each * virtual console serviced by init. * * It works as normal shell does - for each external command it forks * and execs, for each internal command just executes a function. */ int shell(int argc, char **argv) { char buf[BUFSIZE]; char *prompt=" # "; int fd; int res; pid_t mypid; if(motd!=NULL) { if((fd=open(motd,O_RDONLY))!=-1) { do { res=read(fd,buf,BUFSIZE); res=write(1,buf,res); } while(res>0); close(fd); } } printf("\n\n+=========================================================+\n"); printf("| Built-in shell() (enter '?' for short help on commands) |\n"); printf("+=========================================================+\n\n"); getcwd(cwd,BUFSIZE); mypid=getpid(); signal(SIGINT,shell_sig); signal(SIGQUIT,shell_sig); signal(SIGTERM,shell_sig); while(!feof(stdin)) { memset(buf,0,BUFSIZE); printf("(%d)%s%s",mypid,cwd,prompt); fflush(stdout); if(fgets(buf,BUFSIZE-1,stdin)==NULL) continue; buf[strlen(buf)-1]='\0'; if(strlen(buf)==0) continue; do_command(1,buf); } return(0); } /* * Stub for executing some external program on a console. This is called * from previously forked copy of our process, so that exec is ok. */ int external_cmd(int argc, char **argv) { execvp(argv[0],argv); } /* * Acquire vty and properly attach ourselves to it. * Also, build basic environment for running user interface. */ int start_session(int vty, int argc, char **argv) { int fd; char *t; close(0); close(1); close(2); revoke(ttys[vty].tty); fd=open(ttys[vty].tty,O_RDWR); dup2(fd,0); dup2(fd,1); dup2(fd,2); if(fd>2) close(fd); login_tty(fd); setpgid(0,getpid()); putenv("TERM=cons25"); putenv("HOME=/"); putenv("PATH=/stand:/bin:/usr/bin:/sbin:."); signal(SIGHUP,SIG_DFL); signal(SIGINT,SIG_DFL); signal(SIGQUIT,SIG_DFL); signal(SIGTERM,SIG_DFL); chdir("/"); t=(char *)(rindex(ttys[vty].tty,'/')+1); printf("\n\n\nStarting session on %s.\n",t); ttys[vty].func(argc,argv); _exit(0); } /* * Execute system startup script /etc/rc * * (Of course if you don't like it - I don't - you can run anything you * want here. Perhaps it would be useful just to read some config DB and * do these things ourselves, avoiding forking lots of shells and scripts.) */ /* If OINIT_RC is defined, oinit will use it's own configuration file, * /etc/oinit.rc. It's format is described below. Otherwise, it will use * normal /etc/rc interpreted by Bourne shell. */ #ifndef OINIT_RC #ifndef SH_NAME #define SH_NAME "-sh" #endif #ifndef SH_PATH #define SH_PATH _PATH_BSHELL #endif #ifndef SH_ARG #define SH_ARG "/etc/rc" #endif void runcom() { char *argv[3]; pid_t pid; int st; int fd; if((pid=fork())==0) { /* child */ close(0); close(1); close(2); fd=open(_PATH_CONSOLE,O_RDWR); dup2(fd,0); dup2(fd,1); dup2(fd,2); if(fd>2) close(fd); argv[0]=SH_NAME; argv[1]=SH_ARG; argv[2]=0; execvp(SH_PATH,argv); printf("runcom(): %s\n",strerror(errno)); _exit(1); } /* Wait for child to exit */ while(pid!=waitpid(pid,(int *)0,0)) continue; return; } #else /* Alternative /etc/rc - default is /etc/oinit.rc. Its format is as follows: * - each empty line or line beginning with a '#' is discarded * - any other line must contain a keyword, or a (nonblocking) command to run. * * Thus far, the following keywords are defined: * ncons number of virtual consoles to open * motd full path to motd file * * Examples of commands to run: * * ifconfig lo0 inet 127.0.0.1 netmask 255.0.0.0 * ifconfig ed0 inet 148.81.168.10 netmask 255.255.255.0 * kbdcontrol -l /usr/share/syscons/my_map.kbd */ void runcom(char *fname) { int fd; close(0); close(1); close(2); fd=open(_PATH_CONSOLE,O_RDWR); dup2(fd,0); dup2(fd,1); dup2(fd,2); if(fd>2) close(fd); sourcer(fname); } #endif int run_multi() { int i,j; pid_t pid; int found; /* Run /etc/rc if not in single user */ #ifndef OINIT_RC if(prevtrans==SINGLE) runcom(); #else if(prevtrans==SINGLE) runcom(OINIT_RC); #endif if(transition!=MULTI) return(-1); syslog(LOG_EMERG,"*** Starting multi-user mode ***"); /* Fork shell interface for each console */ for(i=0;i %s\n",trans[prevtrans],trans[transition]); if(prevtrans!=transition) longjmp(machine,sig); break; case SIGINT: case SIGQUIT: prevtrans=transition; transition=DEATH; syslog(LOG_EMERG,"*** Going from %s -> %s\n",trans[prevtrans],trans[transition]); if(prevtrans!=transition) longjmp(machine,sig); break; default: syslog(LOG_EMERG,"pid=%d sig=%s (ignored)\n",getpid(),sys_siglist[sig]); break; } } /* * Change system state appropriately to the signals */ int transition_machine() { int i; while(transition!=DEATH) { switch(transition) { case MULTI: run_multi(); break; case SINGLE: run_single(); break; } } syslog(LOG_EMERG,"Killing all existing sessions..."); /* Kill all sessions */ kill(-1,SIGKILL); /* Be nice and wait for them */ while(waitpid(-1,(int *)0,WNOHANG|WUNTRACED)>0) continue; unmount("/",0); reboot(RB_AUTOBOOT); /* NOTREACHED */ } int main(int argc, char **argv) { int devfs=0,c,i; /* These are copied from real init(8) */ if(getuid()!=0) errx(1,"%s",strerror(EPERM)); openlog("init",LOG_CONS|LOG_ODELAY,LOG_AUTH); if(setsid()<0) warn("initial setsid() failed"); if(setlogin("root")<0) warn("setlogin() failed"); close(0); close(1); close(2); chdir("/"); progname=rindex(argv[0],'/'); if(progname==NULL) { progname=argv[0]; } else progname++; transition=MULTI; /* We must recognize the same options as real init does */ while((c=getopt(argc,argv,"dsf"))!=-1) { switch(c) { case 'd': devfs=1; break; case 's': transition=SINGLE; break; case 'f': break; default: printf("%s: unrecognized flag '-%c'\n",progname,c); break; } } if(devfs) mount("devfs",_PATH_DEV,MNT_NOEXEC|MNT_RDONLY,0); /* Fill in the sess structures. */ /* XXX Really, should be filled based upon config file. */ for(i=0;i