shell.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

	FILE * fd;
	int c;
	if (out) {
	  fd=fopen(name,"r");
	  if (fd) {
  	   while ((c=fgetc(fd))!=EOF) fputc(c,out);
	   fclose(fd);
	  };
	};  
}

void write_file(char * name,char * content) {
	FILE * fd;
	fd=fopen(name,"w");
	if (fd) {
  	 fwrite(content,1,strlen(content),fd);
	 fclose(fd);
	};  
}

void init_issue(void) {
 static char issue_inited=FALSE;
 struct stat buf;
 if (issue_inited) return;
 issue_inited=TRUE;
 getpwnam("root"); /* dummy call to init /etc dir */
 if (stat("/etc/issue",&buf)) 
  write_file("/etc/issue",
 	     "Welcome to @V\\n"
	     "Login into @S(@L)\\n");
 if (stat("/etc/issue.net",&buf)) 
  write_file("/etc/issue.net",
 	     "Welcome to %v\n"
	     "running on %m\n");
}

int shell_login(FILE * in,FILE * out) {
	FILE * fd;
	int c;
	time_t t;
	int times;
	char name[128];
	char pass[128];
	struct passwd * passwd;
	init_issue();
        setuid(0);
        setgid(0);
        rtems_current_user_env->euid=
        rtems_current_user_env->egid=0;
	if (out) {
         if((current_shell_env->devname[5]!='p')||
            (current_shell_env->devname[6]!='t')||
            (current_shell_env->devname[7]!='y')) {
	  fd=fopen("/etc/issue","r");
	  if (fd) {
  	   while ((c=fgetc(fd))!=EOF) {
 	    if (c=='@')  {
             switch(c=fgetc(fd)) {
	      case 'L':fprintf(out,"%s",current_shell_env->devname);
	 	      break;
	      case 'B':fprintf(out,"0");
		      break;
              case 'T':
              case 'D':time(&t);
		      fprintf(out,"%s",ctime(&t));
		      break;
              case 'S':fprintf(out,"RTEMS");
		      break;
              case 'V':fprintf(out,"%s\n%s",_RTEMS_version,_Copyright_Notice);
		      break;
              case '@':fprintf(out,"@");
		      break;
	      default :fprintf(out,"@%c",c);
		      break;
	     };
 	    } else 
 	    if (c=='\\')  {
             switch(c=fgetc(fd)) {
	      case '\\':fprintf(out,"\\");
	 	      break;
	      case 'b':fprintf(out,"\b"); break;
	      case 'f':fprintf(out,"\f"); break;
	      case 'n':fprintf(out,"\n"); break;
	      case 'r':fprintf(out,"\r"); break;
	      case 's':fprintf(out," "); break;
	      case 't':fprintf(out,"\t"); break;
              case '@':fprintf(out,"@"); break;
	     };
 	    } else {
             fputc(c,out);				
	    }; 
	   };
	   fclose(fd);
	  } 
	 } else {  
	  fd=fopen("/etc/issue.net","r");
	  if (fd) {
  	   while ((c=fgetc(fd))!=EOF) {
 	    if (c=='%')  {
             switch(c=fgetc(fd)) {
	      case 't':fprintf(out,"%s",current_shell_env->devname);
	 	      break;
	      case 'h':fprintf(out,"0");
		      break;
              case 'D':fprintf(out," ");
		      break;
              case 'd':time(&t);
		      fprintf(out,"%s",ctime(&t));
		      break;
              case 's':fprintf(out,"RTEMS");
		      break;
              case 'm':fprintf(out,"(" CPU_NAME "/" CPU_MODEL_NAME ")");
		      break;
              case 'r':fprintf(out,_RTEMS_version);
		      break;
              case 'v':fprintf(out,"%s\n%s",_RTEMS_version,_Copyright_Notice);
		      break;
              case '%':fprintf(out,"%%");
		      break;
	      default :fprintf(out,"%%%c",c);
		      break;
	     };
 	    } else {
             fputc(c,out);				
	    }; 
	   };
	   fclose(fd);
	  } 
	 };
 	};
	times=0;
	strcpy(name,"");
	strcpy(pass,"");
	for (;;) {
		times++;
		if (times>3) break;
		if (out) fprintf(out,"\nlogin: ");
                if (!shell_scanline(name,sizeof(name),in,out )) break;
		if (out) fprintf(out,"Password: ");
                if (!shell_scanline(pass,sizeof(pass),in,NULL)) break;
		if (out) fprintf(out,"\n");
		if ((passwd=getpwnam(name))) {
		 if (strcmp(passwd->pw_passwd,"!")) { /* valid user */
                  setuid(passwd->pw_uid);			
                  setgid(passwd->pw_gid);			
		  rtems_current_user_env->euid=
		  rtems_current_user_env->egid=0;
		  chown(current_shell_env->devname,passwd->pw_uid,0);
		  rtems_current_user_env->euid=passwd->pw_uid;			
		  rtems_current_user_env->egid=passwd->pw_gid;			
		  if (!strcmp(passwd->pw_passwd,"*")) {
		   /* /etc/shadow */
		   return 0;
		  } else {
		   /* crypt() */
		   return 0;
		  };
		 };
		};
		if (out) fprintf(out,"Login incorrect\n");
	        strcpy(name,"");
	        strcpy(pass,"");
	};
	return -1;
}

rtems_task shell_shell(rtems_task_argument task_argument) {

  shell_env_t * shell_env =(shell_env_t*) task_argument;
  shell_cmd_t * shell_cmd;

  rtems_status_code sc;

  struct termios term;	
  char * devname;

  char curdir[256];
  char cmd[256];
  char last_cmd[256]; /* to repeat 'r' */
  int  argc;
  char * argv[128];

  sc=rtems_task_variable_add(RTEMS_SELF,(void*)&current_shell_env,free);
  if (sc!=RTEMS_SUCCESSFUL) {
   rtems_error(sc,"rtems_task_variable_add(current_shell_env):");	 
   rtems_task_delete(RTEMS_SELF);
  }; 

  current_shell_env=shell_env;  
  
  sc=rtems_libio_set_private_env();
  if (sc!=RTEMS_SUCCESSFUL) {
   rtems_error(sc,"rtems_libio_set_private_env():");	 
   rtems_task_delete(RTEMS_SELF);
  }; 


  devname=shell_env->devname;
  setuid(0);
  setgid(0);
  rtems_current_user_env->euid=
  rtems_current_user_env->egid=0;

  stdin =fopen(devname,"r+");
    
  if (!stdin) {
   fprintf(stderr,"shell:unable to open stdin.%s:%s\n",devname,strerror(errno));
   rtems_task_delete(RTEMS_SELF);
  };
  setvbuf(stdin,NULL,_IONBF,0); /* Not buffered*/
  /* make a raw terminal,Linux MANuals */
  if (tcgetattr (fileno(stdin), &term)>=0) {
   term.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP|INLCR|IGNCR|ICRNL|IXON);
   term.c_oflag &= ~OPOST;
   term.c_oflag |= (OPOST|ONLCR); /* But with cr+nl on output */
   term.c_lflag &= ~(ECHO|ECHONL|ICANON|ISIG|IEXTEN);
   term.c_cflag  = CLOCAL | CREAD |(shell_env->tcflag);
   term.c_cc[VMIN]  = 1;
   term.c_cc[VTIME] = 0;
   if (tcsetattr (fileno(stdin), TCSADRAIN, &term) < 0) {
     fprintf(stderr,"shell:cannot set terminal attributes(%s)\n",devname);
   };
   stdout=fopen(devname,"r+");
   if (!stdout) {
    fprintf(stderr,"shell:unable to open stdout.%s:%s\n",devname,strerror(errno));
   };
   setvbuf(stdout,NULL,_IONBF,0); /* Not buffered*/
   stderr=fopen(devname,"r+");
   if (!stderr) {
    printf("shell:unable to open stderr.%s:%s\n",devname,strerror(errno));
   };
   /* when the future user environment runs ok
    * a freopen() reopens the terminals. Now this don't work
    * (sorry but you can't use because FILENO_STDIN!=0. Better fileno(stdin))
    */
  };
  shell_add_cmd(NULL,NULL,NULL,NULL); /* init the chain list*/
  do {
   /* Set again root user and root filesystem, side effect of set_priv..*/	  
  sc=rtems_libio_set_private_env();
  if (sc!=RTEMS_SUCCESSFUL) {
   rtems_error(sc,"rtems_libio_set_private_env():");	 
   rtems_task_delete(RTEMS_SELF);
  };
  if (!shell_login(stdin,stdout))  {
   cat_file(stdout,"/etc/motd");
   strcpy(last_cmd,"");
   strcpy(cmd,"");
   printf("\n"
          "RTEMS SHELL (Ver.1.0-FRC):%s. "__DATE__". 'help' to list commands.\n",devname);
   chdir("/"); /* XXX: chdir to getpwent homedir */
   shell_env->exit_shell=FALSE;
   for (;;) {
    /* Prompt section */	  
    /* XXX: show_prompt user adjustable */
    getcwd(curdir,sizeof(curdir));
    printf("%s [%s] %c ",shell_env->taskname,curdir,geteuid()?'$':'#');
    /* getcmd section */	  
    if (!shell_scanline(cmd,sizeof(cmd),stdin,stdout)) break; /*EOF*/
    /* evaluate cmd section */	  
    if (!strcmp(cmd,"e")) {  /* edit last command */
     strcpy(cmd,last_cmd);
     continue;
    } else 
    if (!strcmp(cmd,"r")) {  /* repeat last command */
     strcpy(cmd,last_cmd);
    } else 
    if (strcmp(cmd,"")) { /* only for get a new prompt */
     strcpy(last_cmd,cmd);
    }; 
    /* exec cmd section */	  
    /* TODO: 
     *  To avoid user crash catch the signals. 
     *  Open a new stdio files with posibility of redirection *
     *  Run in a new shell task background. (unix &)
     *  Resuming. A little bash.
     */	  
    if (shell_make_args(cmd,&argc,argv)) {
     if ((shell_cmd=shell_lookup_cmd(argv[0]))!=NULL) {
      shell_env->errorlevel=shell_cmd->command(argc,argv);
     } else {
      printf("shell:%s command not found\n",argv[0]);
      shell_env->errorlevel=-1;
     };
    };
    /* end exec cmd section */	  
    if (shell_env->exit_shell)  break;
    cmd[0]=0;
   };
   printf("\nGoodbye from RTEMS SHELL :-(\n");
  };
  } while (shell_env->forever);
  fclose(stdin );
  fclose(stdout); 
  fclose(stderr);
  rtems_task_delete(RTEMS_SELF);
}
/* ----------------------------------------------- */
rtems_status_code   shell_init (char * task_name,
				rtems_unsigned32    task_stacksize,
				rtems_task_priority task_priority,
				char * devname,
				tcflag_t tcflag,
				int forever) {
 rtems_id task_id;
 rtems_status_code sc;
 shell_env_t * shell_env;
 sc=rtems_task_create(new_rtems_name(task_name),
 		     task_priority,
		     task_stacksize?task_stacksize:RTEMS_MINIMUM_STACK_SIZE,
		     RTEMS_DEFAULT_MODES,
		     RTEMS_LOCAL | RTEMS_FLOATING_POINT,
		     &task_id);
 if (sc!=RTEMS_SUCCESSFUL) {
  rtems_error(sc,"creating task %s in shell_init()",task_name);	 
  return sc;
 }; 
 shell_env=malloc(sizeof(shell_env_t));
 if (!shell_env) {
  rtems_task_delete(task_id);
  sc=RTEMS_NO_MEMORY;	 
  rtems_error(sc,"allocating shell_env %s in shell_init()",task_name);	 
  return sc;
 };
 if (global_shell_env.magic!=new_rtems_name("SENV")) {
  global_shell_env.magic     =new_rtems_name("SENV");
  global_shell_env.devname   ="/dev/console";
  global_shell_env.taskname  ="GLOBAL";
  global_shell_env.tcflag    =0;
  global_shell_env.exit_shell=0;
  global_shell_env.forever   =TRUE;
 }; 
 shell_env->magic     =global_shell_env.magic; 
 shell_env->devname   =devname;
 shell_env->taskname  =task_name;
 shell_env->tcflag    =tcflag;
 shell_env->exit_shell=FALSE;
 shell_env->forever   =forever;
 return rtems_task_start(task_id,shell_shell,(rtems_task_argument) shell_env);
}