xref: /src/usr.sbin/rpc.pcnfsd/pcnfsd_misc.c

/*	$NetBSD: pcnfsd_misc.c,v 1.17 2020/04/22 23:46:02 joerg Exp $	*/

/* RE_SID: @(%)/usr/dosnfs/shades_SCCS/unix/pcnfsd/v2/src/SCCS/s.pcnfsd_misc.c 1.5 92/01/24 19:59:13 SMI */
/*
**=====================================================================
** Copyright (c) 1986,1987,1988,1989,1990,1991 by Sun Microsystems, Inc.
**	@(#)pcnfsd_misc.c	1.5	1/24/92
**=====================================================================
*/
/*
**=====================================================================
**             I N C L U D E   F I L E   S E C T I O N                *
**                                                                    *
** If your port requires different include files, add a suitable      *
** #define in the customization section, and make the inclusion or    *
** exclusion of the files conditional on this.                        *
**=====================================================================
*/

#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/wait.h>

#include <netinet/in.h>
#include <arpa/inet.h>

#include <ctype.h>
#include <errno.h>
#include <netdb.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <util.h>
#ifdef SUPPORT_UTMPX
#include <utmpx.h>
#endif

#ifdef ISC_2_0
#include <sys/fcntl.h>
#endif

#ifdef SHADOW_SUPPORT
#include <shadow.h>
#endif

#ifdef WTMP
int     wtmp_enabled = 1;
#endif

#include "common.h"
#include "pcnfsd.h"
#include "extern.h"

/*
**---------------------------------------------------------------------
** Other #define's
**---------------------------------------------------------------------
*/

#define	zchar		0x5b

char   *mapfont(char, char, char);
void	myhandler(int);
void	start_watchdog(int);
void	stop_watchdog(void);

/*
**=====================================================================
**                      C O D E   S E C T I O N                       *
**=====================================================================
*/
/*
**---------------------------------------------------------------------
**                          Support procedures
**---------------------------------------------------------------------
*/


void
scramble(char *s1, char *s2)
{
	while (*s1) {
		*s2++ = (*s1 ^ zchar) & 0x7f;
		s1++;
	}
	*s2 = 0;
}



struct passwd *
get_password(char *usrnam)
{
	struct passwd *p;
	static struct passwd localp;
	__aconst char *pswd, *ushell;


#ifdef SHADOW_SUPPORT
	struct spwd *sp;
	int     shadowfile;
#endif

#ifdef SHADOW_SUPPORT
/*
**--------------------------------------------------------------
** Check the existence of SHADOW.  If it is there, then we are
** running a two-password-file system.
**--------------------------------------------------------------
*/
	if (access(SHADOW, 0))
		shadowfile = 0;	/* SHADOW is not there */
	else
		shadowfile = 1;

	setpwent();
	if (shadowfile)
		(void) setspent();	/* Setting the shadow password file */
	if ((p = getpwnam(usrnam)) == NULL ||
	    (shadowfile && (sp = getspnam(usrnam)) == NULL))
		return (NULL);

	if (shadowfile) {
		pswd = sp->sp_pwdp;
		(void) endspent();
	} else
		pswd = p->pw_passwd;

#else
	p = getpwnam(usrnam);
	if (p == NULL)
		return (NULL);
	pswd = p->pw_passwd;
#endif

#ifdef ISC_2_0
/* *----------------------------------------------------------- * We
 * may have an 'x' in which case look in /etc/shadow ..
 * *----------------------------------------------------------- */
	if (((strlen(pswd)) == 1) && pswd[0] == 'x') {
		struct spwd *shadow = getspnam(usrnam);

		if (!shadow)
			return (NULL);
		pswd = shadow->sp_pwdp;
	}
#endif
	localp = *p;
	localp.pw_passwd = pswd;
#ifdef USE_GETUSERSHELL

	setusershell();
	while (ushell = getusershell()) {
		if (!strcmp(ushell, localp.pw_shell)) {
			ok = 1;
			break;
		}
	}
	endusershell();
	if (!ok)
		return (NULL);
#else
/*
* the best we can do is to ensure that the shell ends in "sh"
*/
	ushell = localp.pw_shell;
	if (strlen(ushell) < 2)
		return (NULL);
	ushell += strlen(ushell) - 2;
	if (strcmp(ushell, "sh"))
		return (NULL);

#endif
	return (&localp);
}



/*
**---------------------------------------------------------------------
**                      Print support procedures
**---------------------------------------------------------------------
*/


char   *
mapfont(char f, char i, char b)
{
	static char fontname[64];

	fontname[0] = 0;	/* clear it out */

	switch (f) {
	case 'c':
		(void) strlcpy(fontname, "Courier", sizeof(fontname));
		break;
	case 'h':
		(void) strlcpy(fontname, "Helvetica", sizeof(fontname));
		break;
	case 't':
		(void) strlcpy(fontname, "Times", sizeof(fontname));
		break;
	default:
		(void) strlcpy(fontname, "Times-Roman", sizeof(fontname));
		goto finis;
	}
	if (i != 'o' && b != 'b') {	/* no bold or oblique */
		if (f == 't')	/* special case Times */
			(void) strlcat(fontname, "-Roman", sizeof(fontname));
		goto finis;
	}
	(void) strlcat(fontname, "-", sizeof(fontname));
	if (b == 'b')
		(void) strlcat(fontname, "Bold", sizeof(fontname));
	if (i == 'o')		/* o-blique */
		(void) strlcat(fontname, f == 't' ? "Italic" : "Oblique",
		    sizeof(fontname));

finis:	return (&fontname[0]);
}
/*
* run_ps630 performs the Diablo 630 emulation filtering process. ps630
* was broken in certain Sun releases: it would not accept point size or
* font changes. If your version is fixed, undefine the symbol
* PS630_IS_BROKEN and rebuild pc-nfsd.
*/
/* #define PS630_IS_BROKEN 1 */

void
run_ps630(char *f, char *opts)
{
	char    temp_file[256];
	char    commbuf[256];
	int     i;

	(void) strlcpy(temp_file, f, sizeof(temp_file));
	(void) strlcat(temp_file, "X", sizeof(temp_file)); /* intermediate file name */

#ifndef PS630_IS_BROKEN
	(void) snprintf(commbuf, sizeof(commbuf), "ps630 -s %c%c -p %s -f ",
	    opts[2], opts[3], temp_file);
	(void) strlcat(commbuf, mapfont(opts[4], opts[5], opts[6]),
	    sizeof(commbuf));
	(void) strlcat(commbuf, " -F ", sizeof(commbuf));
	(void) strlcat(commbuf, mapfont(opts[7], opts[8], opts[9]),
	    sizeof(commbuf));
	(void) strlcat(commbuf, "  ", sizeof(commbuf));
	(void) strlcat(commbuf, f, sizeof(commbuf));
#else				/* PS630_IS_BROKEN */
/*
 * The pitch and font features of ps630 appear to be broken at
 * this time.
 */
	(void) snprintf(commbuf, sizeof(commbuf), "ps630 -p %s %s",
	    temp_file, f);
#endif				/* PS630_IS_BROKEN */


	if ((i = system(commbuf)) != 0) {
		/*
		 * Under (un)certain conditions, ps630 may return -1 even
		 * if it worked. Hence the commenting out of this error
		 * report.
		 */
		 /* (void)fprintf(stderr, "\n\nrun_ps630 rc = %d\n", i) */ ;
		/* exit(1); */
	}
	if (rename(temp_file, f)) {
		perror("run_ps630: rename");
		exit(1);
	}
	return;
}





/*
**---------------------------------------------------------------------
**                      WTMP update support
**---------------------------------------------------------------------
*/


#ifdef WTMP
void
wlogin(char *name, struct svc_req *req)
{
	struct sockaddr_in *who;
	struct hostent *hp;
	char *host;

	if (!wtmp_enabled)
		return;

/* Get network address of client. */
	who = &req->rq_xprt->xp_raddr;

/* Get name of connected client */
	hp = gethostbyaddr((char *) &who->sin_addr,
	    sizeof(struct in_addr),
	    who->sin_family);

	if (hp) {
		host = hp->h_name;
	} else {
		host = inet_ntoa(who->sin_addr);
	}

#ifdef SUPPORT_UTMP
	logwtmp("PC-NFS", name, host);
#endif
#ifdef SUPPORT_UTMPX
	logwtmpx("PC-NFS", name, host, 0, USER_PROCESS);
#endif
}
#endif				/* WTMP */


/*
**---------------------------------------------------------------------
**                      Run-process-as-user procedures
**---------------------------------------------------------------------
*/


#define	READER_FD	0
#define	WRITER_FD	1

static int child_pid;

static char cached_user[64] = "";
static uid_t cached_uid;
static gid_t cached_gid;

static struct sigaction old_action;
static struct sigaction new_action;
static struct itimerval timer;

int     interrupted = 0;
static FILE *pipe_handle;

void
myhandler(int dummy)
{
	interrupted = 1;
	fclose(pipe_handle);
	kill(child_pid, SIGKILL);
	msg_out("rpc.pcnfsd: su_popen timeout - killed child process");
}

void
start_watchdog(int n)
{
/*
 * Setup SIGALRM handler, force interrupt of ongoing syscall
 */

	new_action.sa_handler = myhandler;
	sigemptyset(&(new_action.sa_mask));
	new_action.sa_flags = 0;
#ifdef SA_INTERRUPT
	new_action.sa_flags |= SA_INTERRUPT;
#endif
	sigaction(SIGALRM, &new_action, &old_action);

/*
 * Set interval timer for n seconds
 */
	timer.it_interval.tv_sec = 0;
	timer.it_interval.tv_usec = 0;
	timer.it_value.tv_sec = n;
	timer.it_value.tv_usec = 0;
	setitimer(ITIMER_REAL, &timer, NULL);
	interrupted = 0;

}

void
stop_watchdog()
{
/*
 * Cancel timer
 */

	timer.it_interval.tv_sec = 0;
	timer.it_interval.tv_usec = 0;
	timer.it_value.tv_sec = 0;
	timer.it_value.tv_usec = 0;
	setitimer(ITIMER_REAL, &timer, NULL);

/*
 * restore old signal handling
 */
	sigaction(SIGALRM, &old_action, NULL);
}

FILE   *
su_popen(char *user, char *cmd, int maxtime)
{
	int     p[2];
	int     parent_fd, child_fd, pid;
	struct passwd *pw;

	if (strcmp(cached_user, user)) {
		pw = getpwnam(user);
		if (!pw)
			pw = getpwnam("nobody");
		if (pw) {
			cached_uid = pw->pw_uid;
			cached_gid = pw->pw_gid;
			strlcpy(cached_user, user, sizeof(cached_user));
		} else {
			cached_uid = (uid_t) (-2);
			cached_gid = (gid_t) (-2);
			cached_user[0] = '\0';
		}
	}
	if (pipe(p) < 0) {
		msg_out("rpc.pcnfsd: unable to create pipe in su_popen");
		return (NULL);
	}
	parent_fd = p[READER_FD];
	child_fd = p[WRITER_FD];
	if ((pid = fork()) == 0) {
		int     i;

		for (i = 0; i < 10; i++)
			if (i != child_fd)
				(void) close(i);
		if (child_fd != 1) {
			(void) dup2(child_fd, 1);
			(void) close(child_fd);
		}
		dup2(1, 2);	/* let's get stderr as well */

		(void) setgid(cached_gid);
		(void) setuid(cached_uid);

		(void) execl("/bin/sh", "sh", "-c", cmd, (char *) NULL);
		_exit(255);
	}
	if (pid == -1) {
		msg_out("rpc.pcnfsd: fork failed");
		close(parent_fd);
		close(child_fd);
		return (NULL);
	}
	child_pid = pid;
	close(child_fd);
	start_watchdog(maxtime);
	pipe_handle = fdopen(parent_fd, "r");
	return (pipe_handle);
}

int
su_pclose(FILE *ptr)
{
	int     pid, status;

	stop_watchdog();

	fclose(ptr);
	if (child_pid == -1)
		return (-1);
	while ((pid = wait(&status)) != child_pid && pid != -1);
	return (pid == -1 ? -1 : status);
}



/*
** The following routine reads a file "/etc/pcnfsd.conf" if present,
** and uses it to replace certain builtin elements, like the
** name of the print spool directory. The configuration file
** Is the usual kind: Comments begin with '#', blank lines are ignored,
** and valid lines are of the form
**
**	<keyword><whitespace><value>
**
** The following keywords are recognized:
**
**	spooldir
**	printer name alias-for command
**	wtmp yes|no
*/
static void
config_from_file(void)
{
	FILE   *fd;
	char    buff[1024];
	char   *cp;
	char   *kw;
	char   *val;
	char   *arg1;
	char   *arg2;

	if ((fd = fopen("/etc/pcnfsd.conf", "r")) == NULL)
		return;
	while (fgets(buff, 1024, fd)) {
		cp = strchr(buff, '\n');
		*cp = '\0';
		cp = strchr(buff, '#');
		if (cp)
			*cp = '\0';
		kw = strtok(buff, " \t");
		if (kw == NULL)
			continue;
		val = strtok(NULL, " \t");
		if (val == NULL)
			continue;
		if (!strcasecmp(kw, "spooldir")) {
			strlcpy(sp_name, val, sizeof(sp_name));
			continue;
		}
#ifdef WTMP
		if (!strcasecmp(kw, "wtmp")) {
			/* assume default is YES, just look for negatives */
			if (!strcasecmp(val, "no") ||
			    !strcasecmp(val, "off") ||
			    !strcasecmp(val, "disable") ||
			    !strcmp(val, "0"))
				wtmp_enabled = 0;
			continue;
		}
#endif
		if (!strcasecmp(kw, "printer")) {
			arg1 = strtok(NULL, " \t");
			arg2 = strtok(NULL, "");
			(void) add_printer_alias(val, arg1, arg2);
			continue;
		}
/*
** Add new cases here
*/
	}
	fclose(fd);
}

/*
** hack for main() - call config_from_file() then the real main
** in the rpcgen output, which is hacked by CPPFLAGS to be "mymain"
*/
#undef main

int mymain(int argc, char *argv[]);

int
main(int argc, char *argv[])
{
	config_from_file();
	return mymain(argc, argv);
}

/*
** strembedded - returns true if s1 is embedded (in any case) in s2
*/

int
strembedded(const char *s1, const char *s2)
{
	while (*s2) {
		if (!strcasecmp(s1, s2))
			return 1;
		s2++;
	}
	return 0;
}