getgrent.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 830 行 · 第 1/2 页

		setgrent_local();
		return(NULL);
	}
	gp = interpret(line1, strlen(line1));
		switch(line1[0]) {
			case '+':
				goto again_local;
			case '-':
				goto again_local;
			default:
				return(gp);
		}
}

struct group *
getgrent_bind()
{
	char bindbuf[64];
	struct group *gp = NULL;

	sprintf(bindbuf, "group-%d", svc_getgrbind);
#ifdef DEBUG
	fprintf(stderr, "getgrent_bind(%s)\n", bindbuf);
#endif DEBUG
	if ((gp = getgrnam_bind(bindbuf)) == NULL)
		return(NULL);
	svc_getgrbind++;
	return(gp);
}

struct group *
getgrent_yp()
{
	char line1[BUFSIZ+1];
	static struct group *savegp, *gp;

#ifdef DEBUG
	fprintf (stderr,"getgrent_yp\n");
#endif DEBUG
	if (grf == NULL && (grf = fopen(GROUP, "r")) == NULL && (domain = yellowup(1)) == NULL)
		return(NULL);
again:
	if (yp) {
		gp = interpretwithsave(yp, yplen, savegp);
		free(yp);
		getnextfromyellow();
		if (onminuslist(gp))
			goto again;
		else
			return(gp);
	}
	else if (fgets(line1, BUFSIZ, grf) == NULL)
		return(NULL);
	gp = interpret(line1, strlen(line1));
		switch(line1[0]) {
			case '+':
				if (strcmp(gp->gr_name, "+") == 0) {
					getfirstfromyellow();
					savegp = save(gp);
					goto again;
				}
				savegp = save(gp);
				gp = getnamefromyellow(gp->gr_name+1, savegp);
				if (gp == NULL)
					goto again;
				else if (onminuslist(gp))
					goto again;
				else
					return(gp);
			case '-':
				addtominuslist(gp->gr_name+1);
				goto again;
			default:
				if (onminuslist(gp))
					goto again;
				return(gp);
		}
}

static char *
grskip(p,c)
	register char *p;
	register c;
{
	while(*p && *p != c && *p != '\n') ++p;
	if(*p) *p++ = 0;
	return(p);
}

static struct group *
interpret(val, len)
	char *val;
{
	register char *p, **q;
	static struct group gp;
	static char line[BUFSIZ+1];

	strncpy(line, val, len);
	p = line;
	line[len] = '\n';
	line[len+1] = 0;

	gp.gr_name = p;
	gp.gr_passwd = p = grskip(p,':');
	gp.gr_gid = atoi(p = grskip(p,':'));
	gp.gr_mem = gr_mem;
	p = grskip(p,':');
	grskip(p,'\n');
	q = gr_mem;
	while(*p){
		if (q < &gr_mem[MAXGRP-1])
			*q++ = p;
		p = grskip(p,',');
	}
	*q = NULL;
	return(&gp);
}

static
freeminuslist() {
	struct list *ls;
	
	for (ls = minuslist; ls != NULL; ls = ls->nxt) {
		free(ls->name);
		free(ls);
	}
	minuslist = NULL;
}

static struct group *
interpretwithsave(val, len, savegp)
	char *val;
	struct group *savegp;
{
	struct group *gp;
	
	gp = interpret(val, len);
	if (savegp->gr_passwd && *savegp->gr_passwd)
		gp->gr_passwd =  savegp->gr_passwd;
	if (savegp->gr_mem && *savegp->gr_mem)
		gp->gr_mem = savegp->gr_mem;
	return(gp);
}

static
onminuslist(gp)
	struct group *gp;
{
	struct list *ls;
	register char *nm;
	
	nm = gp->gr_name;
	for (ls = minuslist; ls != NULL; ls = ls->nxt)
		if (strcmp(ls->name, nm) == 0)
			return(1);
	return(0);
}

static
getnextfromyellow()
{
	int reason = 0;
	char *key = NULL;
	int keylen = 0;
	
	if (reason = yp_next(domain, "group.byname", oldyp, oldyplen, &key, &keylen, &yp, &yplen)) {
#ifdef DEBUG
		fprintf(stderr, "reason yp_next failed is %d\n", reason);
#endif
		yp = NULL;
	}
	if (oldyp)
		free(oldyp);
	oldyp = key;
	oldyplen = keylen;
}

static
getfirstfromyellow()
{
	int reason = 0;
	char *key = NULL;
	int keylen = 0;
	
	if (reason =  yp_first(domain, "group.byname", &key, &keylen, &yp, &yplen)) {
#ifdef DEBUG
		fprintf(stderr, "reason yp_first failed is %d\n", reason);
#endif
		yp = NULL;
	}
	if (oldyp)
		free(oldyp);
	oldyp = key;
	oldyplen = keylen;
}

static struct group *
getnamefromyellow(name, savegp)
	char *name;
	struct group *savegp;
{
	struct group *gp;
	int reason;
	char *val = NULL;
	int vallen = 0;
	
	if (reason = yp_match(domain, "group.byname", name, strlen(name), &val, &vallen)) {
#ifdef DEBUG
		fprintf(stderr, "reason yp_next failed is %d\n", reason);
#endif
		return(NULL);
	}
	else {
		gp = interpret(val, vallen);
		free(val);
		if (savegp->gr_passwd && *savegp->gr_passwd)
			gp->gr_passwd =  savegp->gr_passwd;
		if (savegp->gr_mem && *savegp->gr_mem)
			gp->gr_mem = savegp->gr_mem;
		return(gp);
	}
}

static
addtominuslist(name)
	char *name;
{
	struct list *ls;
	char *buf;
	
	ls = (struct list *)malloc(sizeof(struct list));
	buf = (char *)malloc(strlen(name) + 1);
	strcpy(buf, name);
	ls->name = buf;
	ls->nxt = minuslist;
	minuslist = ls;
}

/* 
 * save away psswd, gr_mem fields, which are the only
 * ones which can be specified in a local + entry to override the
 * value in the yellow pages
 */
static struct group *
save(gp)
	struct group *gp;
{
	static struct group *sv;
	char *gr_mem[MAXGRP];	
	char **av, **q;
	int lnth;
	
	/*
	* free up stuff from last time around
	*/
	if (sv) {
		for (av = sv->gr_mem; *av != NULL; av++) {
			if (q >= &gr_mem[MAXGRP-1])
				break;
			free(*q);
			q++;
		}
		free(sv->gr_passwd);
		free(sv->gr_mem);
		free(sv);
	}
	sv = (struct group *)malloc(sizeof(struct group));
	sv->gr_passwd = (char *)malloc(strlen(gp->gr_passwd) + 1);
	strcpy(sv->gr_passwd, gp->gr_passwd);

	q = gr_mem;
	for (av = gp->gr_mem; *av != NULL; av++) {
		if (q >= &gr_mem[MAXGRP-1])
			break;
		*q = (char *)malloc(strlen(*av) + 1);
		strcpy(*q, *av);
		q++;
	}
	*q = 0;
	lnth = (sizeof (char *)) * (q - gr_mem + 1);
	sv->gr_mem = (char **)malloc(lnth);
	bcopy(gr_mem, sv->gr_mem, lnth);
	return(sv);
}

static
matchname(line1, gpp, name)
	char line1[];
	struct group **gpp;
	char *name;
{
	struct group *savegp;
	struct group *gp = *gpp;

	switch(line1[0]) {
		case '+':
			if (strcmp(gp->gr_name, "+") == 0) {
				savegp = save(gp);
				gp = getnamefromyellow(name, savegp);
				if (gp) {
					*gpp = gp;
					return(1);
				}
				else
					return(0);
			}
			if (strcmp(gp->gr_name+1, name) == 0) {
				savegp = save(gp);
				gp = getnamefromyellow(gp->gr_name+1, savegp);
				if (gp) {
					*gpp = gp;
					return(1);
				}
				else
					return(0);
			}
			break;
		case '-':
			if (strcmp(gp->gr_name+1, name) == 0) {
				*gpp = NULL;
				return(1);
			}
			break;
		default:
			if (strcmp(gp->gr_name, name) == 0)
				return(1);
	}
	return(0);
}

static
matchgid(line1, gpp, gid)
	char line1[];
	struct group **gpp;
{
	struct group *savegp;
	struct group *gp = *gpp;

	switch(line1[0]) {
		case '+':
			if (strcmp(gp->gr_name, "+") == 0) {
				savegp = save(gp);
				gp = getgidfromyellow(gid, savegp);
				if (gp) {
					*gpp = gp;
					return(1);
				}
				else
					return(0);
			}
			savegp = save(gp);
			gp = getnamefromyellow(gp->gr_name+1, savegp);
			if (gp && gp->gr_gid == gid) {
				*gpp = gp;
				return(1);
			}
			else
				return(0);
		case '-':
			if (gid == gidof(gp->gr_name+1)) {
				*gpp = NULL;
				return(1);
			}
			break;
		default:
			if (gp->gr_gid == gid)
				return(1);
	}
	return(0);
}

static
gidof(name)
	char *name;
{
	struct group *gp;
	struct group nullgp;
	
	nullgp = NULLGP;
	gp = getnamefromyellow(name, &nullgp);
	if (gp)
		return(gp->gr_gid);
	else
		return(MAXINT);
}

static struct group *
getgidfromyellow(gid, savegp)
	int gid;
	struct group *savegp;
{
	struct group *gp;
	int reason = 0;
	char *val = NULL;
	int vallen = 0;
	char gidstr[20];
	
	sprintf(gidstr, "%d", gid);
	if (reason = yp_match(domain, "group.bygid", gidstr, strlen(gidstr), &val, &vallen)) {
#ifdef DEBUG
		fprintf(stderr, "reason yp_next failed is %d\n", reason);
#endif
		return(NULL);
	}
	else {
		gp = interpret(val, vallen);
		free(val);
		if (savegp->gr_passwd && *savegp->gr_passwd)
			gp->gr_passwd =  savegp->gr_passwd;
		if (savegp->gr_mem && *savegp->gr_mem)
			gp->gr_mem = savegp->gr_mem;
		return(gp);
	}
}