/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 * Common Development and Distribution License, Version 1.0 only

 * (the "License").  You may not use this file except in compliance

 * with the License.

 *

 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

 * or http://www.opensolaris.org/os/licensing.

 * See the License for the specific language governing permissions

 * and limitations under the License.

 *

 * When distributing Covered Code, include this CDDL HEADER in each

 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.

 * If applicable, add the following below this CDDL HEADER, with the

 * fields enclosed by brackets "[]" replaced with your own identifying

 * information: Portions Copyright [yyyy] [name of copyright owner]

 *

 * CDDL HEADER END

 */

/*

 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/

/*	  All Rights Reserved  	*/

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*

 * UNIX shell

 */

#include	"defs.h"

#include	"sym.h"

#include	"timeout.h"

#include	<stdio.h>

#include	<sys/types.h>

#include	<sys/stat.h>

#include	<sys/wait.h>

#include	"dup.h"

#include	"sh_policy.h"

#ifdef RES

#include	<sgtty.h>

#endif

pid_t mypid, mypgid, mysid;

static BOOL	beenhere = FALSE;

unsigned char	tmpout[TMPOUTSZ];

struct fileblk	stdfile;

struct fileblk *standin = &stdfile;

int mailchk = 0;

static unsigned char	*mailp;

static long	*mod_time = 0;

static BOOL login_shell = FALSE;

#if vax

char **execargs = (char **)(0x7ffffffc);

#endif

#if pdp11

char **execargs = (char **)(-2);

#endif

static void	exfile();

extern unsigned char 	*simple();

static void Ldup(int, int);

void settmp(void);

void chkmail(void);

void setmail(unsigned char *);

int

main(int c, char *v[], char *e[])

{

	int		rflag = ttyflg;

	int		rsflag = 1;	/* local restricted flag */

	unsigned char	*flagc = flagadr;

	struct namnod	*n;

	mypid = getpid();

	mypgid = getpgid(mypid);

	mysid = getsid(mypid);

	/*

	 * Do locale processing only if /usr is mounted.

	 */

	localedir_exists = (access(localedir, F_OK) == 0);

	/*

	 * initialize storage allocation

	 */

	if (stakbot == 0) {

	addblok((unsigned)0);

	}

	/*

	 * If the first character of the last path element of v[0] is "-"

	 * (ex. -sh, or /bin/-sh), this is a login shell

	 */

	if (*simple(v[0]) == '-') {

		signal(SIGXCPU, SIG_DFL);

		signal(SIGXFSZ, SIG_DFL);

		/*

		 * As the previous comment states, this is a login shell.

		 * Therefore, we set the login_shell flag to explicitly

		 * indicate this condition.

		 */

		login_shell = TRUE;

	}

	stdsigs();

	/*

	 * set names from userenv

	 */

	setup_env();

	/*

	 * LC_MESSAGES is set here so that early error messages will

	 * come out in the right style.

	 * Note that LC_CTYPE is done later on and is *not*

	 * taken from the previous environ

	 */

	/*

	 * Do locale processing only if /usr is mounted.

	 */

	if (localedir_exists)

		(void) setlocale(LC_ALL, "");

#if !defined(TEXT_DOMAIN)	/* Should be defined by cc -D */

#define	TEXT_DOMAIN "SYS_TEST"	/* Use this only if it weren't */

#endif

	(void) textdomain(TEXT_DOMAIN);

	/*

	 * This is a profile shell if the simple name of argv[0] is

	 * pfsh or -pfsh

	 */

	if (c > 0 && (eq("pfsh", simple(*v)) || eq("-pfsh", simple(*v)))) {

		flags |= pfshflg;

		secpolicy_init();

	}

	/*

	 * 'rsflag' is zero if SHELL variable is

	 *  set in environment and

	 *  the simple file part of the value.

	 *  is rsh

	 */

		if (eq("rsh", simple(n->namval)))

			rsflag = 0;

	}

	/*

	 * a shell is also restricted if the simple name of argv(0) is

	 * rsh or -rsh in its simple name

	 */

#ifndef RES

	if (c > 0 && (eq("rsh", simple(*v)) || eq("-rsh", simple(*v))))

		rflag = 0;

#endif

	if (eq("jsh", simple(*v)) || eq("-jsh", simple(*v)))

		flags |= monitorflg;

	hcreate();

	set_dotpath();

	/*

	 * look for options

	 * dolc is $#

	 */

	dolc = options(c, v);

		flags |= stdflg;

		{

			while (*flagc)

				flagc++;

			*flagc++ = STDFLG;

			*flagc = 0;

		}

	}

	if ((flags & stdflg) == 0)

		dolc--;

	if ((flags & privflg) == 0) {

		uid_t euid;

		gid_t egid;

		uid_t ruid;

		gid_t rgid;

		/*

		 * Determine all of the user's id #'s for this process and

		 * then decide if this shell is being entered as a result

		 * of a fork/exec.

		 * If the effective uid/gid do NOT match and the euid/egid

		 * is < 100 and the egid is NOT 1, reset the uid and gid to

		 * the user originally calling this process.

		 */

		euid = geteuid();

		ruid = getuid();

		egid = getegid();

		rgid = getgid();

		if ((euid != ruid) && (euid < 100))

			setuid(ruid);   /* reset the uid to the orig user */

		if ((egid != rgid) && ((egid < 100) && (egid != 1)))

			setgid(rgid);   /* reset the gid to the orig user */

	}

	dolv = (unsigned char **)v + c - dolc;

	dolc--;

	/*

	 * return here for shell file execution

	 * but not for parenthesis subshells

	 */

	if (setjmp(subshell)) {

		freejobs();

		flags |= subsh;

	}

	/*

	 * number of positional parameters

	 */

	replace(&cmdadr, dolv[0]);	/* cmdadr is $0 */

	/*

	 * set pidname '$$'

	 */

	assnum(&pidadr, (long)mypid);

	/*

	 * set up temp file names

	 */

	settmp();

	/*

	 * default internal field separators

	 * Do not allow importing of IFS from parent shell.

	 * setup_env() may have set anything from parent shell to IFS.

	 * Always set the default ifs to IFS.

	 */

	assign(&ifsnod, (unsigned char *)sptbnl);

	dfault(&mchknod, MAILCHECK);

	mailchk = stoi(mchknod.namval);

	/* initialize OPTIND for getopt */

	n = lookup("OPTIND");

	assign(n, (unsigned char *)"1");

	/*

	 * make sure that option parsing starts

	 * at first character

	 */

	_sp = 1;

	/* initialize multibyte information */

	setwidth();

	if ((beenhere++) == FALSE)	/* ? profile */

	{

		if ((login_shell == TRUE) && (flags & privflg) == 0) {

			/* system profile */

#ifndef RES

			if ((input = pathopen(nullstr, sysprofile)) >= 0)

				exfile(rflag);		/* file exists */

#endif

			/* user profile */

				exfile(rflag);

				flags &= ~ttyflg;

			}

		}

		if (rsflag == 0 || rflag == 0) {

			if ((flags & rshflg) == 0) {

				while (*flagc)

					flagc++;

				*flagc++ = 'r';

				*flagc = '\0';

			}

			flags |= rshflg;

		}

		/*

		 * open input file if specified

		 */

			estabf(comdiv);

			input = -1;

		}

		else

		{

			if (flags & stdflg) {

				input = 0;

			} else {

			/*

			 * If the command file specified by 'cmdadr'

			 * doesn't exist, chkopen() will fail calling

			 * exitsh(). If this is a login shell and

			 * the $HOME/.profile file does not exist, the

			 * above statement "flags &= ~ttyflg" does not

			 * get executed and this makes exitsh() call

			 * longjmp() instead of exiting. longjmp() will

			 * return to the location specified by the last

			 * active jmpbuffer, which is the one set up in

			 * the function exfile() called after the system

			 * profile file is executed (see lines above).

			 * This would cause an infinite loop, because

			 * chkopen() will continue to fail and exitsh()

			 * to call longjmp(). To make exitsh() exit instead

			 * of calling longjmp(), we then set the flag forcexit

			 * at this stage.

			 */

				flags |= forcexit;

				input = chkopen(cmdadr, 0);

				flags &= ~forcexit;

			}

#ifdef ACCT

			if (input != 0)

				preacct(cmdadr);

#endif

			comdiv--;

		}

	}

#ifdef pdp11

	else

		*execargs = (char *)dolv;	/* for `ps' cmd */

#endif

	exfile(0);

	done(0);

}

static void

exfile(int prof)

{

	time_t	mailtime = 0;	/* Must not be a register variable */

	time_t 	curtime = 0;

	/*

	 * move input

	 */

		Ldup(input, INIO);

		input = INIO;

	}

	setmode(prof);

		close(input);

		(void) endjobs(0);

		return;

	}

	/*

	 * error return here

	 */

	loopcnt = peekc = peekn = 0;

	fndef = 0;

	nohash = 0;

	iopend = 0;

	if (input >= 0)

		initf(input);

	/*

	 * command loop

	 */

		tdystak(0);

		stakchk();	/* may reduce sbrk */

		exitset();

				time(&curtime);

					chkmail();

					mailtime = curtime;

				}

			}

			/* necessary to print jobs in a timely manner */

			if (trapnote & TRAPSET)

				chktrap();

			prs(ps1nod.namval);

#ifdef TIME_OUT

			alarm(TIMEOUT);

#endif

		}

		trapnote = 0;

		peekc = readwc();

		if (eof) {

			if (endjobs(JOB_STOPPED))

				return;

			eof = 0;

		}

#ifdef TIME_OUT

		alarm(0);

#endif

		{

			struct trenod *t;

			t = cmd(NL, MTFLG);

			if (t == NULL && flags & ttyflg)

				freejobs();

			else

				execute(t, 0, eflag);

		}

		eof |= (flags & oneflg);

	}

}

void

chkpr(void)

{

	if ((flags & prompt) && standin->fstak == 0)

		prs(ps2nod.namval);

}

void

settmp(void)

{

	int len;

	serial = 0;

	if ((len = snprintf((char *)tmpout, TMPOUTSZ, "/tmp/sh%u", mypid)) >=

	    TMPOUTSZ) {

		/*

		 * TMPOUTSZ should be big enough, but if it isn't,

		 * we'll at least try to create tmp files with

		 * a truncated tmpfile name at tmpout.

		 */

		tmpout_offset = TMPOUTSZ - 1;

	} else {

		tmpout_offset = len;

	}

}

static void

Ldup(int fa, int fb)

{

#ifdef RES

	dup(fa | DUPFLG, fb);

	close(fa);

	ioctl(fb, FIOCLEX, 0);

#else

	if (fa >= 0) {

			close(fb);

			fcntl(fa, 0, fb); /* normal dup */

			close(fa);

		}

		fcntl(fb, 2, 1);	/* autoclose for fb */

	}

#endif

}

void

chkmail(void)

{

	unsigned char 	*s = mailp;

	unsigned char	*save;

	long	*ptr = mod_time;

	unsigned char	*start;

	BOOL	flg;

	struct stat	statb;

	while (*s) {

		start = s;

		save = 0;

		flg = 0;

		while (*s) {

			if (*s != COLON) {

				if (*s == '%' && save == 0)

					save = s;

				s++;

			} else {