HardenedBSD/libexec/revnetgroup/parse_netgroup.c
Pedro F. Giffuni 8a16b7a18f General further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:49:47 +00:00

363 lines
9.2 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Rick Macklem at The University of Guelph.
*
* 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 the University 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 THE REGENTS 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 THE REGENTS 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.
*/
#ifndef lint
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
/*
* This is a specially hacked-up version of getnetgrent.c used to parse
* data from the stored hash table of netgroup info rather than from a
* file. It's used mainly for the parse_netgroup() function. All the YP
* stuff and file support has been stripped out since it isn't needed.
*/
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>
#include <unistd.h>
#include "hash.h"
/*
* Static Variables and functions used by setnetgrent(), getnetgrent() and
* __endnetgrent().
* There are two linked lists:
* - linelist is just used by setnetgrent() to parse the net group file via.
* parse_netgrp()
* - netgrp is the list of entries for the current netgroup
*/
struct linelist {
struct linelist *l_next; /* Chain ptr. */
int l_parsed; /* Flag for cycles */
char *l_groupname; /* Name of netgroup */
char *l_line; /* Netgroup entrie(s) to be parsed */
};
struct netgrp {
struct netgrp *ng_next; /* Chain ptr */
char *ng_str[3]; /* Field pointers, see below */
};
#define NG_HOST 0 /* Host name */
#define NG_USER 1 /* User name */
#define NG_DOM 2 /* and Domain name */
static struct linelist *linehead = (struct linelist *)0;
static struct netgrp *nextgrp = (struct netgrp *)0;
static struct {
struct netgrp *gr;
char *grname;
} grouphead = {
(struct netgrp *)0,
(char *)0,
};
static int parse_netgrp(char *group);
static struct linelist *read_for_group(char *group);
extern struct group_entry *gtable[];
/*
* setnetgrent()
* Parse the netgroup file looking for the netgroup and build the list
* of netgrp structures. Let parse_netgrp() and read_for_group() do
* most of the work.
*/
void
__setnetgrent(char *group)
{
/* Sanity check */
if (group == NULL || !strlen(group))
return;
if (grouphead.gr == (struct netgrp *)0 ||
strcmp(group, grouphead.grname)) {
__endnetgrent();
if (parse_netgrp(group))
__endnetgrent();
else {
grouphead.grname = (char *)
malloc(strlen(group) + 1);
strcpy(grouphead.grname, group);
}
}
nextgrp = grouphead.gr;
}
/*
* Get the next netgroup off the list.
*/
int
__getnetgrent(char **hostp, char **userp, char **domp)
{
if (nextgrp) {
*hostp = nextgrp->ng_str[NG_HOST];
*userp = nextgrp->ng_str[NG_USER];
*domp = nextgrp->ng_str[NG_DOM];
nextgrp = nextgrp->ng_next;
return (1);
}
return (0);
}
/*
* __endnetgrent() - cleanup
*/
void
__endnetgrent(void)
{
struct linelist *lp, *olp;
struct netgrp *gp, *ogp;
lp = linehead;
while (lp) {
olp = lp;
lp = lp->l_next;
free(olp->l_groupname);
free(olp->l_line);
free((char *)olp);
}
linehead = (struct linelist *)0;
if (grouphead.grname) {
free(grouphead.grname);
grouphead.grname = (char *)0;
}
gp = grouphead.gr;
while (gp) {
ogp = gp;
gp = gp->ng_next;
if (ogp->ng_str[NG_HOST])
free(ogp->ng_str[NG_HOST]);
if (ogp->ng_str[NG_USER])
free(ogp->ng_str[NG_USER]);
if (ogp->ng_str[NG_DOM])
free(ogp->ng_str[NG_DOM]);
free((char *)ogp);
}
grouphead.gr = (struct netgrp *)0;
}
/*
* Parse the netgroup file setting up the linked lists.
*/
static int
parse_netgrp(char *group)
{
char *spos, *epos;
int len, strpos;
#ifdef DEBUG
int fields;
#endif
char *pos, *gpos;
struct netgrp *grp;
struct linelist *lp = linehead;
/*
* First, see if the line has already been read in.
*/
while (lp) {
if (!strcmp(group, lp->l_groupname))
break;
lp = lp->l_next;
}
if (lp == (struct linelist *)0 &&
(lp = read_for_group(group)) == (struct linelist *)0)
return (1);
if (lp->l_parsed) {
#ifdef DEBUG
/*
* This error message is largely superfluous since the
* code handles the error condition successfully, and
* spewing it out from inside libc can actually hose
* certain programs.
*/
warnx("cycle in netgroup %s", lp->l_groupname);
#endif
return (1);
} else
lp->l_parsed = 1;
pos = lp->l_line;
/* Watch for null pointer dereferences, dammit! */
while (pos != NULL && *pos != '\0') {
if (*pos == '(') {
grp = (struct netgrp *)malloc(sizeof (struct netgrp));
bzero((char *)grp, sizeof (struct netgrp));
grp->ng_next = grouphead.gr;
grouphead.gr = grp;
pos++;
gpos = strsep(&pos, ")");
#ifdef DEBUG
fields = 0;
#endif
for (strpos = 0; strpos < 3; strpos++) {
if ((spos = strsep(&gpos, ","))) {
#ifdef DEBUG
fields++;
#endif
while (*spos == ' ' || *spos == '\t')
spos++;
if ((epos = strpbrk(spos, " \t"))) {
*epos = '\0';
len = epos - spos;
} else
len = strlen(spos);
if (len > 0) {
grp->ng_str[strpos] = (char *)
malloc(len + 1);
bcopy(spos, grp->ng_str[strpos],
len + 1);
}
} else {
/*
* All other systems I've tested
* return NULL for empty netgroup
* fields. It's up to user programs
* to handle the NULLs appropriately.
*/
grp->ng_str[strpos] = NULL;
}
}
#ifdef DEBUG
/*
* Note: on other platforms, malformed netgroup
* entries are not normally flagged. While we
* can catch bad entries and report them, we should
* stay silent by default for compatibility's sake.
*/
if (fields < 3)
warnx("bad entry (%s%s%s%s%s) in netgroup \"%s\"",
grp->ng_str[NG_HOST] == NULL ? "" : grp->ng_str[NG_HOST],
grp->ng_str[NG_USER] == NULL ? "" : ",",
grp->ng_str[NG_USER] == NULL ? "" : grp->ng_str[NG_USER],
grp->ng_str[NG_DOM] == NULL ? "" : ",",
grp->ng_str[NG_DOM] == NULL ? "" : grp->ng_str[NG_DOM],
lp->l_groupname);
#endif
} else {
spos = strsep(&pos, ", \t");
if (parse_netgrp(spos))
continue;
}
/* Watch for null pointer dereferences, dammit! */
if (pos != NULL)
while (*pos == ' ' || *pos == ',' || *pos == '\t')
pos++;
}
return (0);
}
/*
* Read the netgroup file and save lines until the line for the netgroup
* is found. Return 1 if eof is encountered.
*/
static struct linelist *
read_for_group(char *group)
{
char *pos, *spos, *linep = NULL, *olinep = NULL;
int len, olen;
int cont;
struct linelist *lp;
char line[LINSIZ + 1];
char *data = NULL;
data = lookup (gtable, group);
sprintf(line, "%s %s", group, data);
pos = (char *)&line;
#ifdef CANT_HAPPEN
if (*pos == '#')
continue;
#endif
while (*pos == ' ' || *pos == '\t')
pos++;
spos = pos;
while (*pos != ' ' && *pos != '\t' && *pos != '\n' &&
*pos != '\0')
pos++;
len = pos - spos;
while (*pos == ' ' || *pos == '\t')
pos++;
if (*pos != '\n' && *pos != '\0') {
lp = (struct linelist *)malloc(sizeof (*lp));
lp->l_parsed = 0;
lp->l_groupname = (char *)malloc(len + 1);
bcopy(spos, lp->l_groupname, len);
*(lp->l_groupname + len) = '\0';
len = strlen(pos);
olen = 0;
/*
* Loop around handling line continuations.
*/
do {
if (*(pos + len - 1) == '\n')
len--;
if (*(pos + len - 1) == '\\') {
len--;
cont = 1;
} else
cont = 0;
if (len > 0) {
linep = (char *)malloc(olen + len + 1);
if (olen > 0) {
bcopy(olinep, linep, olen);
free(olinep);
}
bcopy(pos, linep + olen, len);
olen += len;
*(linep + olen) = '\0';
olinep = linep;
}
#ifdef CANT_HAPPEN
if (cont) {
if (fgets(line, LINSIZ, netf)) {
pos = line;
len = strlen(pos);
} else
cont = 0;
}
#endif
} while (cont);
lp->l_line = linep;
lp->l_next = linehead;
linehead = lp;
#ifdef CANT_HAPPEN
/*
* If this is the one we wanted, we are done.
*/
if (!strcmp(lp->l_groupname, group))
#endif
return (lp);
}
return ((struct linelist *)0);
}