shadow.c

这是一个SIGMA方案的PMP播放器的UCLINUX程序,可播放DVD,VCD,CD MP3...有很好的参考价值.

/* vi: set sw=4 ts=4: */
/*
 * Copyright 1989 - 1994, Julianne Frances Haugh 
 *			<[e-mail]>, <[e-mail]>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Julianne F. Haugh nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/* TODO:  fgetspent_r.c  getspent_r.c  getspnam_r.c sgetspent_r.c 
 *		  lckpwdf  ulckpwdf 
 */

#include "busybox.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "shadow_.h"

static FILE *shadow;
static char spwbuf[BUFSIZ];
static struct spwd spwd;

#define	FIELDS	9
#define	OFIELDS	5

/* setspent - initialize access to shadow text and DBM files */
void setspent(void)
{
	if (shadow) {
		rewind(shadow);
	} else {
		if ((shadow = fopen("/etc/shadow", "r")) == NULL)
			perror_msg_and_die("/etc/shadow");
	}
}

/* endspent - terminate access to shadow text and DBM files */
void endspent(void)
{
	if (shadow)
		(void) fclose(shadow);
	shadow = (FILE *) 0;
}

/* getspent - get a (struct spwd *) from the current shadow file */
struct spwd *getspent(void)
{
	if (!shadow)
		setspent();
	return (fgetspent(shadow));
}

/* getspnam - get a shadow entry by name */
struct spwd *getspnam(const char *name)
{
	struct spwd *sp;

	if (!name || !strlen(name))
		return NULL;

	setspent();
	while ((sp = getspent()) != NULL) {
		if (strcmp(name, sp->sp_namp) == 0)
			break;
	}
	endspent();
	return (sp);
}


/* sgetspent - convert string in shadow file format to (struct spwd *) */
/* returns NULL on error */
struct spwd *sgetspent(const char *string)
{
	char *fields[FIELDS];
	char *cp;
	char *cpp;
	int i;

	/*
	 * Copy string to local buffer.  It has to be tokenized and we
	 * have to do that to our private copy.
	 */

	if (strlen(string) >= sizeof spwbuf)
		/* return 0; */
		return NULL;
	strcpy(spwbuf, string);

	if ((cp = strrchr(spwbuf, '\n')))
		*cp = '\0';

	/*
	 * Tokenize the string into colon separated fields.  Allow up to
	 * FIELDS different fields.
	 */

	for (cp = spwbuf, i = 0; *cp && i < FIELDS; i++) {
		fields[i] = cp;
		while (*cp && *cp != ':')
			cp++;

		if (*cp)
			*cp++ = '\0';
	}

	/*
	 * It is acceptable for the last SVR4 field to be blank.  This
	 * results in the loop being terminated early.  In which case,
	 * we just make the last field be blank and be done with it.
	 */

	if (i == (FIELDS - 1))
		fields[i++] = cp;

	if ((cp && *cp) || (i != FIELDS && i != OFIELDS))
		/* return 0; */
		return NULL;

	/*
	 * Start populating the structure.  The fields are all in
	 * static storage, as is the structure we pass back.  If we
	 * ever see a name with '+' as the first character, we try
	 * to turn on NIS processing.
	 */

	spwd.sp_namp = fields[0];
	spwd.sp_pwdp = fields[1];

	/*
	 * Get the last changed date.  For all of the integer fields,
	 * we check for proper format.  It is an error to have an
	 * incorrectly formatted number, unless we are using NIS.
	 */

	if ((spwd.sp_lstchg = strtol(fields[2], &cpp, 10)) == 0 && *cpp) {
		/* return 0; */
		return NULL;
	} else if (fields[2][0] == '\0')
		spwd.sp_lstchg = -1;

	/*
	 * Get the minimum period between password changes.
	 */

	if ((spwd.sp_min = strtol(fields[3], &cpp, 10)) == 0 && *cpp) {
		/* return 0; */
		return NULL;
	} else if (fields[3][0] == '\0')
		spwd.sp_min = -1;

	/*
	 * Get the maximum number of days a password is valid.
	 */

	if ((spwd.sp_max = strtol(fields[4], &cpp, 10)) == 0 && *cpp) {
		/* return 0; */
		return NULL;
	} else if (fields[4][0] == '\0')
		spwd.sp_max = -1;

	/*
	 * If there are only OFIELDS fields (this is a SVR3.2 /etc/shadow
	 * formatted file), initialize the other field members to -1.
	 */

	if (i == OFIELDS) {
		spwd.sp_warn = spwd.sp_inact = spwd.sp_expire = spwd.sp_flag = -1;

		return &spwd;
	}

	/*
	 * The rest of the fields are mandatory for SVR4, but optional
	 * for anything else.  However, if one is present the others
	 * must be as well.
	 */

	/*
	 * Get the number of days of password expiry warning.
	 */

	if ((spwd.sp_warn = strtol(fields[5], &cpp, 10)) == 0 && *cpp) {
		/* return 0; */
		return NULL;
	} else if (fields[5][0] == '\0')
		spwd.sp_warn = -1;

	/*
	 * Get the number of days of inactivity before an account is
	 * disabled.
	 */

	if ((spwd.sp_inact = strtol(fields[6], &cpp, 10)) == 0 && *cpp) {
		/* return 0; */
		return NULL;
	} else if (fields[6][0] == '\0')
		spwd.sp_inact = -1;

	/*
	 * Get the number of days after the epoch before the account is
	 * set to expire.
	 */

	if ((spwd.sp_expire = strtol(fields[7], &cpp, 10)) == 0 && *cpp) {
		/* return 0; */
		return NULL;
	} else if (fields[7][0] == '\0')
		spwd.sp_expire = -1;

	/*
	 * This field is reserved for future use.  But it isn't supposed
	 * to have anything other than a valid integer in it.
	 */

	if ((spwd.sp_flag = strtol(fields[8], &cpp, 10)) == 0 && *cpp) {
		/* return 0; */
		return NULL;
	} else if (fields[8][0] == '\0')
		spwd.sp_flag = -1;

	return (&spwd);
}

/* fgetspent - get an entry from an /etc/shadow formatted stream */
struct spwd *fgetspent(FILE *fp)
{
	char buf[BUFSIZ];
	char *cp;

	if (!fp)
		/* return (0); */
		return NULL;

	if (fgets(buf, sizeof buf, fp) != (char *) 0) {
		if ((cp = strchr(buf, '\n')))
			*cp = '\0';
		return (sgetspent(buf));
	}
	/* return 0; */
	return NULL;
}

/*
 * putspent - put a (struct spwd *) into the (FILE *) you provide.
 * 
 *	this was described in shadow_.h but not implemented, so here
 *	I go.  -beppu
 *
 */
int putspent(const struct spwd *sp, FILE *fp)
{
	int ret;

	/* seek to end */
	ret = fseek(fp, 0, SEEK_END);
	if (ret == -1) {
		/* return -1; */
		return 1;
	}

	/* powered by fprintf */
	fprintf(fp, "%s:%s:%ld:%ld:%ld:%ld:%ld:%ld:%s\n", sp->sp_namp,	/* login name */
			sp->sp_pwdp,		/* encrypted password */
			sp->sp_lstchg,		/* date of last change */
			sp->sp_min,			/* minimum number of days between changes */
			sp->sp_max,			/* maximum number of days between changes */
			sp->sp_warn,		/* number of days of warning before password expires */
			sp->sp_inact,		/* number of days after password expires until 
								   the account becomes unusable */
			sp->sp_expire,		/* days since 1/1/70 until account expires */
			"");
	return 0;
}