BSD 4_2 release

[unix-history] / usr / src / old / berknet / nsh.c

static char sccsid[] = "@(#)nsh.c       4.3     (Berkeley)      5/20/83";

# include "defs.h"
/*
       nsh -c "comand to be executed"

       This pseudo-shell is executed over the network
       as the login shell of an acount "network", no passwd.
       It will only execute certain allowed commands.

       has these exit codes:
               EX_USAGE =      wrong # arguments to nsh
               9 =             command you execute may not take arguments
               10=             the execl failed
               EX_UNAVAILABLE= could not find full path name for the command

       count is the # of arguments (= argc) allowed.
       a count of 0 turns off the command
*/

struct {
       char *app;
       char count;
       char *full;
       char *full1;
       } st[] = {
/* I assume these are the same for RAND */
       "mmail",        20,     "/usr/net/bin/mmail",   "/usr/net/bin/mmail",
       "mwrite",       20,     "/usr/net/bin/mwrite",  "/usr/net/bin/mwrite",
       "prmail",       20,     "/usr/net/bin/prmail",  "/usr/net/bin/prmail",
# ifndef NFREECMD
       "finger",       20,     "/usr/ucb/finger",      "/usr/bin/finger",
       "lpq",          20,     "/usr/ucb/lpq",         "/usr/bin/lpq",
# ifdef FREELPR
       "lpr",          20,     "/usr/ucb/lpr",         "/usr/bin/lpr",
# endif
       "netlog",       20,     "/usr/bin/netlog",      "/usr/ucb/netlog",
       "netq",         20,     "/usr/bin/netq",        "/usr/ucb/netq",
       "ps",           20,     "/bin/ps",              "/usr/bin/ps",
       "pstat",        20,     "/etc/pstat",           "/usr/bin/pstat",
       "vpq",          20,     "/usr/ucb/vpq",         "/usr/bin/vpq",
       "w",            20,     "/usr/ucb/w",           "/usr/bin/w",
       "wc",           20,     "/usr/bin/wc",          "/bin/wc",
       "who",          20,     "/bin/who",             "/usr/bin/who",
       "whom",         20,     "/usr/ucb/whom",        "/usr/bin/whom",
       "yank",         20,     "/usr/ucb/yank",        "/usr/bin/yank",
# endif
       0,              0,              0,              0
       };
/* nsh -c cmd */
main(argc,argv)
 char **argv; {
       char *s, buf[500];
       int i, flg = 0;
       if(argc != 3){
               fprintf(stderr,"Wrong number of arguments to nsh.\n");
               exit(EX_USAGE);
       }
       s = argv[2];
       while (*s)
               if (*s == ';'
                || *s == '|'
                || *s == '&'
                || *s == '?'
                || *s == '*'
                || *s == '['
                || *s == '~'
                || *s == '{'
                || *s == '<'
                || *s == '>'
                || *s == '$'
                || *s == '`') {
                       fprintf(stderr, "Illegal shell metacharacter in command.\n");
                       exit(9);
               } else
                       ++s;
       s = argv[2];
       while(*s && *s != ' ')s++;
       if(*s == ' ')flg++;
       *s = 0;
       if((i = mlookup(argv[2])) < 0){
               fprintf(stderr,
               "Command '%s' is not allowed if logged in as 'network'.\n",
                       argv[2]);
               exit(11);
       }
       if(st[i].count == 0){
               fprintf(stderr,
               "The command '%s' is not allowed to have arguments.\n",argv[2]);
               exit(9);
               }
       if(stat(st[i].full,buf) >= 0)
               strcpy(buf,st[i].full);
       else strcpy(buf,st[i].full1);
       if(flg && st[i].count > 1){  /* some cmds don't allow parms */
               *s = ' ';
               strcat(buf,s);
               }
       /*
       fprintf(stderr,"%s\n",buf);
       */
       execl(Bsh,"sh","-c",buf,0);
       fprintf(stderr,"Execute of shell failed.\n");
       exit(EX_UNAVAILABLE);
       }
mlookup(s)
 char *s; {
       int i;
       for(i = 0; st[i].app; i++)
               if(strcmp(st[i].app,s) == 0 || strcmp(st[i].full,s) == 0
                || strcmp(st[i].full1,s) == 0)return(i);
       return(-1);
       }