/* $NetBSD: utils.c,v 1.21 2012/03/20 18:50:30 matt Exp $ */

/*-
 * Copyright (c) 2002, 2003 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Roland C. Dowdeswell.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: utils.c,v 1.21 2012/03/20 18:50:30 matt Exp $");
#endif

#include <sys/param.h>

#include <stdlib.h>
#include <string.h>
#include <err.h>
#include <util.h>

/* include the resolver gunk in order that we can use b64 routines */
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>

#include "utils.h"


/* just strsep(3), but skips empty fields. */

static char *
strsep_getnext(char **stringp, const char *delim)
{
        char    *ret;

        ret = strsep(stringp, delim);
        while (ret && index(delim, *ret))
                ret = strsep(stringp, delim);
        return ret;
}

/*
 * this function returns a dynamically sized char ** of the words
 * in the line.  the caller is responsible for both free(3)ing
 * each word and the superstructure by calling words_free().
 */
char **
words(const char *line, int *num)
{
        int       i = 0;
        int       nwords = 0;
        char     *cur;
        char    **ret;
        const char       *tmp;
        char     *tmp1, *tmpf;

        *num = 0;
        tmp = line;
        if (tmp[0] == '\0')
                return NULL;
        while (tmp[0]) {
                if ((tmp[1] == ' ' || tmp[1] == '\t' || tmp[1] == '\0') &&
                    (tmp[0] != ' ' && tmp[0] != '\t'))
                        nwords++;
                tmp++;
        }
        ret = emalloc((nwords+1) * sizeof(char *));
        tmp1 = tmpf = estrdup(line);
        while ((cur = strsep_getnext(&tmpf, " \t")) != NULL)
                ret[i++] = estrdup(cur);
        ret[i] = NULL;
        free(tmp1);
        *num = nwords;
        return ret;
}

void
words_free(char **w, int num)
{
        int     i;

        for (i=0; i < num; i++)
                free(w[i]);
}

/*
 * this is a simple xor that has the same calling conventions as
 * memcpy(3).
 */

void
memxor(void *res, const void *src, size_t len)
{
        char *r;
        const char *s;
        size_t i;

        r = res;
        s = src;
        for (i = 0; i < len; i++)
                r[i] ^= s[i];
}

/*
 * well, a very simple set of string functions...
 *
 * The goal here is basically to manage length encoded strings,
 * but just for safety we nul terminate them anyway.
 */

/* for now we use a very simple encoding */

struct string {
        char    *text;
        size_t   length;
};

string_t *
string_zero(void)
{
        string_t *out;

        out = emalloc(sizeof(*out));
        out->length = 0;
        out->text = NULL;
        return out;
}

string_t *
string_new(const char *intext, size_t inlength)
{
        string_t *out;

        out = emalloc(sizeof(*out));
        out->length = inlength;
        out->text = emalloc(out->length + 1);
        (void)memcpy(out->text, intext, out->length);
        out->text[out->length] = '\0';
        return out;
}

string_t *
string_dup(const string_t *in)
{

        return string_new(in->text, in->length);
}

void
string_free(string_t *s)
{

        if (!s)
                return;
        free(s->text);
        free(s);
}

void
string_assign(string_t **lhs, string_t *rhs)
{

        string_free(*lhs);
        *lhs = rhs;
}

string_t *
string_add(const string_t *a1, const string_t *a2)
{
        string_t *sum;

        sum = emalloc(sizeof(*sum));
        sum->length = a1->length + a2->length;
        sum->text = emalloc(sum->length + 1);
        (void)memcpy(sum->text, a1->text, a1->length);
        (void)memcpy(sum->text + a1->length, a2->text, a2->length);
        sum->text[sum->length] = '\0';
        return sum;
}

string_t *
string_add_d(string_t *a1, string_t *a2)
{
        string_t *sum;

        sum = string_add(a1, a2);
        string_free(a1);
        string_free(a2);
        return sum;
}

string_t *
string_fromcharstar(const char *in)
{

        return string_new(in, strlen(in));
}

const char *
string_tocharstar(const string_t *in)
{

        return in->text;
}

string_t *
string_fromint(int in)
{
        string_t *ret;

        ret = emalloc(sizeof(*ret));
        ret->length = asprintf(&ret->text, "%d", in);
        if (ret->text == NULL)
                err(1, NULL);
        return ret;
}

void
string_fprint(FILE *f, const string_t *s)
{
        (void)fwrite(s->text, s->length, 1, f);
}

struct bits {
        size_t   length;
        char    *text;
};

bits_t *
bits_new(const void *buf, size_t len)
{
        bits_t  *b;

        b = emalloc(sizeof(*b));
        b->length = len;
        b->text = emalloc(BITS2BYTES(b->length));
        (void)memcpy(b->text, buf, BITS2BYTES(b->length));
        return b;
}

bits_t *
bits_dup(const bits_t *in)
{

        return bits_new(in->text, in->length);
}

void
bits_free(bits_t *b)
{

        if (!b)
                return;
        free(b->text);
        free(b);
}

void
bits_assign(bits_t **lhs, bits_t *rhs)
{

        bits_free(*lhs);
        *lhs = rhs;
}

const void *
bits_getbuf(bits_t *in)
{

        return in->text;
}

size_t
bits_len(bits_t *in)
{

        return in->length;
}

int
bits_match(const bits_t *b1, const bits_t *b2)
{
        size_t i;

        if (b1->length != b2->length)
                return 0;

        for (i = 0; i < BITS2BYTES(b1->length); i++)
                if (b1->text[i] != b2->text[i])
                        return 0;

        return 1;
}

bits_t *
bits_xor(const bits_t *x1, const bits_t *x2)
{
        bits_t  *b;
        size_t   i;

        b = emalloc(sizeof(*b));
        b->length = MAX(x1->length, x2->length);
        b->text = ecalloc(1, BITS2BYTES(b->length));
        for (i=0; i < BITS2BYTES(MIN(x1->length, x2->length)); i++)
                b->text[i] = x1->text[i] ^ x2->text[i];
        return b;
}

bits_t *
bits_xor_d(bits_t *x1, bits_t *x2)
{
        bits_t  *ret;

        ret = bits_xor(x1, x2);
        bits_free(x1);
        bits_free(x2);
        return ret;
}

/*
 * bits_decode() reads an encoded base64 stream.  We interpret
 * the first 32 bits as an unsigned integer in network byte order
 * specifying the number of bits in the stream to give a little
 * resilience.
 */

bits_t *
bits_decode(const string_t *in)
{
        bits_t  *ret;
        size_t   len;
        size_t   nbits;
        u_int32_t       *tmp;

        len = in->length;
        tmp = emalloc(len);

        len = __b64_pton(in->text, (void *)tmp, len);

        if (len == (size_t)-1) {
                warnx("bits_decode: mangled base64 stream");
                warnx("  %s", in->text);
                free(tmp);
                return NULL;
        }

        nbits = ntohl(*tmp);
        if (nbits > (len - sizeof(*tmp)) * NBBY) {
                warnx("bits_decode: encoded bits claim to be "
                    "longer than they are (nbits=%zu, stream len=%zu bytes)",
                    nbits, len);
                free(tmp);
                return NULL;
        }

        ret = bits_new(tmp + 1, nbits);
        free(tmp);
        return ret;
}

bits_t *
bits_decode_d(string_t *in)
{
        bits_t *ret;

        ret = bits_decode(in);
        string_free(in);
        return ret;
}

string_t *
bits_encode(const bits_t *in)
{
        string_t *ret;
        size_t   len;
        char    *out;
        u_int32_t *tmp;

        if (!in)
                return NULL;

        /* compute the total size of the input stream */
        len = BITS2BYTES(in->length) + sizeof(*tmp);

        tmp = emalloc(len);
        out = emalloc(len * 2);
        /* stuff the length up front */
        *tmp = htonl(in->length);
        (void)memcpy(tmp + 1, in->text, len - sizeof(*tmp));

        if ((len = __b64_ntop((void *)tmp, len, out, len * 2)) == (size_t)-1) {
                free(out);
                free(tmp);
                return NULL;
        }
        ret = string_new(out, len);
        free(tmp);
        free(out);
        return ret;
}

string_t *
bits_encode_d(bits_t *in)
{
        string_t *ret;

        ret = bits_encode(in);
        bits_free(in);
        return ret;
}

bits_t *
bits_fget(FILE *f, size_t len)
{
        bits_t  *bits;
        int      ret;

        bits = emalloc(sizeof(*bits));
        bits->length = len;
        bits->text = emalloc(BITS2BYTES(bits->length));
        ret = fread(bits->text, BITS2BYTES(bits->length), 1, f);
        if (ret != 1) {
                bits_free(bits);
                return NULL;
        }
        return bits;
}

bits_t *
bits_cget(const char *fn, size_t len)
{
        bits_t  *bits;
        FILE    *f;

        f = fopen(fn, "r");
        if (!f)
                return NULL;

        bits = bits_fget(f, len);
        (void)fclose(f);
        return bits;
}

bits_t *
bits_getrandombits(size_t len, int hard)
{

        return bits_cget((hard ? "/dev/random" : "/dev/urandom"), len);
}

void
bits_fprint(FILE *f, const bits_t *bits)
{
        string_t *s;

        s = bits_encode(bits);
        string_fprint(f, s);
        free(s);
}