port/gen/nss_dbdefs.c

	nss_dbdefs.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include "synonyms.h"
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <nss_dbdefs.h>
#include <limits.h>

/*
 * ALIGN? is there an official definition of this?
 * We use sizeof(long) to cover what we want
 * for both the 32-bit world and 64-bit world.
 */

#define ALIGN(x) ((((long)(x)) + sizeof (long) - 1) & ~(sizeof (long) - 1))

nss_XbyY_buf_t *
_nss_XbyY_buf_alloc(int struct_size, int buffer_size)
{
    nss_XbyY_buf_t  *b;

    /* Use one malloc for dbargs, result struct and buffer */
    b = (nss_XbyY_buf_t *)
        malloc(ALIGN(sizeof (*b)) + struct_size + buffer_size);
    if (b == 0) {
        return (0);
    }
    b->result = (void *)ALIGN(&b[1]);
    b->buffer = (char *)(b->result) + struct_size;
    b->buflen = buffer_size;
    return (b);
}

void
_nss_XbyY_buf_free(nss_XbyY_buf_t *b)
{
    if (b != 0) {
        free(b);
    }
}

/* === Comment:  used by fget{gr,pw,sp}ent */
/* ==== Should do ye olde syslog()ing of suspiciously long lines */

void
_nss_XbyY_fgets(FILE *f, nss_XbyY_args_t *b)
{
    char        buf[LINE_MAX];
    int     len, parsestat;

    if (fgets(buf, LINE_MAX, f) == 0) {
        /* End of file */
        b->returnval = 0;
        b->erange    = 0;
        return;
    }
    len = (int)strlen(buf);
    /* len >= 0 (otherwise we would have got EOF) */
    if (buf[len - 1] != '\n') {
        if ((len + 1) == LINE_MAX) {
            /* Line too long for buffer; too bad */
            while (fgets(buf, LINE_MAX, f) != 0 &&
                buf[strlen(buf) - 1] != '\n') {
                ;
            }
            b->returnval = 0;
            b->erange    = 1;
            return;
        }
        /* case where the file is not terminated with a Newline */
        len++;
    }
    parsestat = (*b->str2ent)(buf, (len - 1), b->buf.result, b->buf.buffer,
        b->buf.buflen);
    if (parsestat == NSS_STR_PARSE_ERANGE) {
        b->returnval = 0;
        b->erange    = 1;
    } else if (parsestat == NSS_STR_PARSE_SUCCESS) {
        b->returnval = b->buf.result;
    }
}

/*
 * parse the aliases string into the buffer and if successful return
 * a char ** pointer to the beginning of the aliases.
 *
 * CAUTION: (instr, instr+lenstr) and (buffer, buffer+buflen) are
 * non-intersecting memory areas. Since this is an internal interface,
 * we should be able to live with that.
 */
char **
_nss_netdb_aliases(const char *instr, int lenstr, char *buffer, int buflen)
    /* "instr" is the beginning of the aliases string */
    /* "buffer" has the return val for success */
    /* "buflen" is the length of the buffer available for aliases */
{
    /*
     * Build the alias-list in the start of the buffer, and copy
     * the strings to the end of the buffer.
     */
    const char
        *instr_limit    = instr + lenstr;
    char    *copyptr    = buffer + buflen;
    char    **aliasp    = (char **)ROUND_UP(buffer, sizeof (*aliasp));
    char    **alias_start   = aliasp;
    int nstrings    = 0;

    for (;;) {
        const char  *str_start;
        size_t      str_len;

        while (instr < instr_limit && isspace(*instr)) {
            instr++;
        }
        if (instr >= instr_limit || *instr == '#') {
            break;
        }
        str_start = instr;
        while (instr < instr_limit && !isspace(*instr)) {
            instr++;
        }

        ++nstrings;

        str_len = instr - str_start;
        copyptr -= str_len + 1;
        if (copyptr <= (char *)(&aliasp[nstrings + 1])) {
            /* Has to be room for the pointer to */
            /* the alias we're about to add,   */
            /* as well as the final NULL ptr.  */
            return (0);
        }
        *aliasp++ = copyptr;
        (void) memcpy(copyptr, str_start, str_len);
        copyptr[str_len] = '\0';
    }
    *aliasp++ = 0;
    return (alias_start);
}