OpenSolaris_b135/lib/nsswitch/user/common/user_common.c
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (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 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*
* Common code and structures used by name-service-switch "user" backends.
* Much of this was taken directly from the files_common.c source.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* An implementation that used mmap() sensibly would be a wonderful thing,
* but this here is just yer standard fgets() thang.
*/
#include "user_common.h"
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <fcntl.h>
#include <poll.h>
#include <unistd.h>
#include <sys/stat.h>
#include <string.h>
/*ARGSUSED*/
nss_status_t
_nss_user_setent(be, dummy)
user_backend_ptr_t be;
void *dummy;
{
if (be->f == 0) {
if (be->filename == 0) {
/* Backend isn't initialized properly? */
return (NSS_UNAVAIL);
}
if ((be->f = fopen(be->filename, "rF")) == 0) {
return (NSS_UNAVAIL);
}
} else {
rewind(be->f);
}
return (NSS_SUCCESS);
}
/*ARGSUSED*/
nss_status_t
_nss_user_endent(be, dummy)
user_backend_ptr_t be;
void *dummy;
{
if (be->f != 0) {
(void) fclose(be->f);
be->f = 0;
}
if (be->buf != 0) {
free(be->buf);
be->buf = 0;
}
return (NSS_SUCCESS);
}
/*
* This routine reads a line, including the processing of continuation
* characters. It always leaves (or inserts) \n\0 at the end of the line.
* It returns the length of the line read, excluding the \n\0. Who's idea
* was this?
* Returns -1 on EOF.
*
* Note that since each concurrent call to _nss_user_read_line has
* it's own FILE pointer, we can use getc_unlocked w/o difficulties,
* a substantial performance win.
*/
int
_nss_user_read_line(f, buffer, buflen)
FILE *f;
char *buffer;
int buflen;
{
int linelen; /* 1st unused slot in buffer */
int c;
/*CONSTCOND*/
while (1) {
linelen = 0;
while (linelen < buflen - 1) { /* "- 1" saves room for \n\0 */
switch (c = getc_unlocked(f)) {
case EOF:
if (linelen == 0 ||
buffer[linelen - 1] == '\\') {
return (-1);
} else {
buffer[linelen ] = '\n';
buffer[linelen + 1] = '\0';
return (linelen);
}
case '\n':
if (linelen > 0 &&
buffer[linelen - 1] == '\\') {
--linelen; /* remove the '\\' */
} else {
buffer[linelen ] = '\n';
buffer[linelen + 1] = '\0';
return (linelen);
}
break;
default:
buffer[linelen++] = c;
}
}
/* Buffer overflow -- eat rest of line and loop again */
/* ===> Should syslog() */
do {
c = getc_unlocked(f);
if (c == EOF) {
return (-1);
}
} while (c != '\n');
}
/*NOTREACHED*/
}
/*
* Could implement this as an iterator function on top of _nss_user_do_all(),
* but the shared code is small enough that it'd be pretty silly.
*/
nss_status_t
_nss_user_XY_all(be, args, netdb, filter, check)
user_backend_ptr_t be;
nss_XbyY_args_t *args;
int netdb; /* whether it uses netdb */
/* format or not */
const char *filter; /* advisory, to speed up */
/* string search */
user_XY_check_func check; /* NULL means one-shot, for getXXent */
{
nss_status_t res;
int parsestat;
if (be->buf == 0 &&
(be->buf = malloc(be->minbuf)) == 0) {
return (NSS_UNAVAIL); /* really panic, malloc failed */
}
if (check != 0 || be->f == 0) {
if ((res = _nss_user_setent(be, 0)) != NSS_SUCCESS) {
return (res);
}
}
res = NSS_NOTFOUND;
/*CONSTCOND*/
while (1) {
char *instr = be->buf;
int linelen;
if ((linelen = _nss_user_read_line(be->f, instr,
be->minbuf)) < 0) {
/* End of file */
args->returnval = 0;
args->erange = 0;
break;
}
if (filter != 0 && strstr(instr, filter) == 0) {
/*
* Optimization: if the entry doesn't contain the
* filter string then it can't be the entry we want,
* so don't bother looking more closely at it.
*/
continue;
}
if (netdb) {
char *first;
char *last;
if ((last = strchr(instr, '#')) == 0) {
last = instr + linelen;
}
*last-- = '\0'; /* Nuke '\n' or #comment */
/*
* Skip leading whitespace. Normally there isn't
* any, so it's not worth calling strspn().
*/
for (first = instr; isspace(*first); first++) {
;
}
if (*first == '\0') {
continue;
}
/*
* Found something non-blank on the line. Skip back
* over any trailing whitespace; since we know
* there's non-whitespace earlier in the line,
* checking for termination is easy.
*/
while (isspace(*last)) {
--last;
}
linelen = last - first + 1;
if (first != instr) {
instr = first;
}
}
args->returnval = 0;
parsestat = (*args->str2ent)(instr, linelen, args->buf.result,
args->buf.buffer, args->buf.buflen);
if (parsestat == NSS_STR_PARSE_SUCCESS) {
args->returnval = args->buf.result;
if (check == 0 || (*check)(args)) {
res = NSS_SUCCESS;
break;
}
} else if (parsestat == NSS_STR_PARSE_ERANGE) {
args->erange = 1; /* should we just skip this */
/* one long line ?? */
} /* else if (parsestat == NSS_STR_PARSE_PARSE) don't care ! */
}
/*
* stayopen is set to 0 by default in order to close the opened
* file. Some applications may break if it is set to 1.
*/
if (check != 0 && !args->stayopen) {
(void) _nss_user_endent(be, 0);
}
return (res);
}
/*ARGSUSED*/
nss_status_t
_nss_user_destr(be, dummy)
user_backend_ptr_t be;
void *dummy;
{
if (be != 0) {
if (be->f != 0) {
(void) _nss_user_endent(be, 0);
}
free((char *)be->filename);
free(be);
}
return (NSS_SUCCESS); /* In case anyone is dumb enough to check */
}
nss_backend_t *
_nss_user_constr(ops, n_ops, filename, min_bufsize)
user_backend_op_t ops[];
int n_ops;
const char *filename;
int min_bufsize;
{
user_backend_ptr_t be;
if ((be = (user_backend_ptr_t)malloc(sizeof (*be))) == 0) {
return (0);
}
be->ops = ops;
be->n_ops = n_ops;
if ((be->filename = strdup(filename)) == NULL) {
free(be);
return (NULL);
}
be->minbuf = min_bufsize;
be->f = 0;
be->buf = 0;
return ((nss_backend_t *)be);
}