4.3BSD - /usr/src/old/berknet/nsh.c

   1: static char sccsid[] = "@(#)nsh.c	4.3	(Berkeley)	5/20/83";
   2: 
   3: # include "defs.h"
   4: /*
   5: 	nsh -c "comand to be executed"
   6: 
   7: 	This pseudo-shell is executed over the network
   8: 	as the login shell of an acount "network", no passwd.
   9: 	It will only execute certain allowed commands.
  10: 
  11: 	has these exit codes:
  12: 		EX_USAGE = 	wrong # arguments to nsh
  13: 		9 = 		command you execute may not take arguments
  14: 		10= 		the execl failed
  15: 		EX_UNAVAILABLE= could not find full path name for the command
  16: 
  17: 	count is the # of arguments (= argc) allowed.
  18: 	a count of 0 turns off the command
  19: */
  20: 
  21: struct {
  22:     char *app;
  23:     char count;
  24:     char *full;
  25:     char *full1;
  26:     } st[] = {
  27: /* I assume these are the same for RAND */
  28:     "mmail",    20, "/usr/net/bin/mmail",   "/usr/net/bin/mmail",
  29:     "mwrite",   20, "/usr/net/bin/mwrite",  "/usr/net/bin/mwrite",
  30:     "prmail",   20, "/usr/net/bin/prmail",  "/usr/net/bin/prmail",
  31: # ifndef NFREECMD
  32:     "finger",   20, "/usr/ucb/finger",  "/usr/bin/finger",
  33:     "lpq",      20, "/usr/ucb/lpq",     "/usr/bin/lpq",
  34: # ifdef FREELPR
  35:     "lpr",      20, "/usr/ucb/lpr",     "/usr/bin/lpr",
  36: # endif
  37:     "netlog",   20, "/usr/bin/netlog",  "/usr/ucb/netlog",
  38:     "netq",     20, "/usr/bin/netq",    "/usr/ucb/netq",
  39:     "ps",       20, "/bin/ps",      "/usr/bin/ps",
  40:     "pstat",    20, "/etc/pstat",       "/usr/bin/pstat",
  41:     "vpq",      20, "/usr/ucb/vpq",     "/usr/bin/vpq",
  42:     "w",        20, "/usr/ucb/w",       "/usr/bin/w",
  43:     "wc",       20, "/usr/bin/wc",      "/bin/wc",
  44:     "who",      20, "/bin/who",     "/usr/bin/who",
  45:     "whom",     20, "/usr/ucb/whom",    "/usr/bin/whom",
  46:     "yank",     20, "/usr/ucb/yank",    "/usr/bin/yank",
  47: # endif
  48:     0,      0,      0,      0
  49:     };
  50: /* nsh -c cmd */
  51: main(argc,argv)
  52:   char **argv; {
  53:     char *s, buf[500];
  54:     int i, flg = 0;
  55:     if(argc != 3){
  56:         fprintf(stderr,"Wrong number of arguments to nsh.\n");
  57:         exit(EX_USAGE);
  58:     }
  59:     s = argv[2];
  60:     while (*s)
  61:         if (*s == ';'
  62:          || *s == '|'
  63:          || *s == '&'
  64:          || *s == '?'
  65:          || *s == '*'
  66:          || *s == '['
  67:          || *s == '~'
  68:          || *s == '{'
  69:          || *s == '<'
  70:          || *s == '>'
  71:          || *s == '$'
  72:          || *s == '`') {
  73:             fprintf(stderr, "Illegal shell metacharacter in command.\n");
  74:             exit(9);
  75:         } else
  76:             ++s;
  77:     s = argv[2];
  78:     while(*s && *s != ' ')s++;
  79:     if(*s == ' ')flg++;
  80:     *s = 0;
  81:     if((i = mlookup(argv[2])) < 0){
  82:         fprintf(stderr,
  83:         "Command '%s' is not allowed if logged in as 'network'.\n",
  84:             argv[2]);
  85:         exit(11);
  86:     }
  87:     if(st[i].count == 0){
  88:         fprintf(stderr,
  89:         "The command '%s' is not allowed to have arguments.\n",argv[2]);
  90:         exit(9);
  91:         }
  92:     if(stat(st[i].full,buf) >= 0)
  93:         strcpy(buf,st[i].full);
  94:     else strcpy(buf,st[i].full1);
  95:     if(flg && st[i].count > 1){  /* some cmds don't allow parms */
  96:         *s = ' ';
  97:         strcat(buf,s);
  98:         }
  99:     /*
 100: 	fprintf(stderr,"%s\n",buf);
 101: 	*/
 102:     execl(Bsh,"sh","-c",buf,0);
 103:     fprintf(stderr,"Execute of shell failed.\n");
 104:     exit(EX_UNAVAILABLE);
 105:     }
 106: mlookup(s)
 107:   char *s; {
 108:     int i;
 109:     for(i = 0; st[i].app; i++)
 110:         if(strcmp(st[i].app,s) == 0 || strcmp(st[i].full,s) == 0
 111:          || strcmp(st[i].full1,s) == 0)return(i);
 112:     return(-1);
 113:     }

Defined functions

Defined variables