/* misc. universal things
 * Copyright (C) 1998, 1999  D. Hugh Redelmeier.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 * RCSID $Id: defs.c,v 1.16 2000/06/21 18:24:31 dhr Exp $
 */

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <sys/types.h>

#include "constants.h"
#include "defs.h"
#include "log.h"
#include "whack.h"	/* for RC_LOG_SERIOUS */

const chunk_t empty_chunk = { NULL, 0 };

void
passert_fail(const char *pred_str, const char *file_str, unsigned long line_no)
{
    /* we will get a possibly unplanned prefix.  Hope it works */
    loglog(RC_LOG_SERIOUS, "ASSERTION FAILED at %s:%lu: %s", file_str, line_no, pred_str);
    abort();	/* exiting correctly doesn't always work */
}


/* Convert MP_INT to network form (binary octets, big-endian).
 * We do the malloc; caller must eventually do free.
 */
chunk_t
mpz_to_n(const MP_INT *mp, size_t bytes)
{
    chunk_t r;
    MP_INT temp1, temp2;
    int i;

    r.len = bytes;
    r.ptr = alloc_bytes(r.len, "host representation of large integer");

    mpz_init(&temp1);
    mpz_init(&temp2);

    mpz_set(&temp1, mp);

    for (i = r.len-1; i >= 0; i--)
    {
	r.ptr[i] = mpz_mdivmod_ui(&temp2, NULL, &temp1, 1 << BITS_PER_BYTE);
	mpz_set(&temp1, &temp2);
    }

    passert(mpz_sgn(&temp1) == 0);	/* we must have done all the bits */
    mpz_clear(&temp1);
    mpz_clear(&temp2);

    return r;
}

/* Convert network form (binary bytes, big-endian) to MP_INT.
 * The *mp must not be previously mpz_inited.
 */
void
n_to_mpz(MP_INT *mp, const u_char *nbytes, size_t nlen)
{
    size_t i;

    mpz_init_set_ui(mp, 0);

    for (i = 0; i != nlen; i++)
    {
	mpz_mul_ui(mp, mp, 1 << BITS_PER_BYTE);
	mpz_add_ui(mp, mp, nbytes[i]);
    }
}


/* memory allocation
 *
 * LEAK_DETECTIVE puts a wrapper around each allocation and maintains
 * a list of live ones.  If a dead one is freed, an assertion MIGHT fail.
 * If the live list is currupted, that will often be detected.
 * In the end, report_leaks() is called, and the names of remaining
 * live allocations are printed.  At the moment, it is hoped, not that
 * the list is empty, but that there will be no surprises.
 *
 * Accepted Leaks:
 * - "struct iface" and "device name" (for "discovered" net interfaces)
 * - "struct event in event_schedule()" (events not associated with states)
 * - "Pluto lock name" (one only, needed until end -- why bother?)
 */

#ifdef LEAK_DETECTIVE

/* this magic number is 3671129837 decimal (623837458 complemented) */
#define LEAK_MAGIC 0xDAD0FEEDul

union mhdr {
    struct {
	const char *name;
	union mhdr *older, *newer;
	unsigned long magic;
    } i;    /* info */
    unsigned long junk;	/* force maximal alignment */
};

static union mhdr *allocs = NULL;

void *alloc_bytes(size_t size, const char *name)
{
	union mhdr *p = malloc(sizeof(union mhdr) + size);

	if (p == NULL)
		exit_log("unable to malloc %lu bytes for %s",
			(unsigned long) size, name);
	p->i.name = name;
	p->i.older = allocs;
	if (allocs != NULL)
	    allocs->i.newer = p;
	allocs = p;
	p->i.newer = NULL;
	p->i.magic = LEAK_MAGIC;

	memset(p+1, '\0', size);
	return p+1;
}

void *
clone_bytes(const void *orig, size_t size, const char *name)
{
	void *p = alloc_bytes(size, name);

	memcpy(p, orig, size);
	return p;
}

void
pfree(void *ptr)
{
	union mhdr *p;

	passert(ptr != NULL);
	p = ((union mhdr *)ptr) - 1;
	passert(p->i.magic == LEAK_MAGIC);
	if (p->i.older != NULL)
	{
		passert(p->i.older->i.newer == p);
		p->i.older->i.newer = p->i.newer;
	}
	if (p->i.newer == NULL)
	{
		passert(p == allocs);
		allocs = p->i.older;
	}
	else
	{
		passert(p->i.newer->i.older == p);
		p->i.newer->i.older = p->i.older;
	}
	p->i.magic = ~LEAK_MAGIC;
	free(p);
}

void
report_leaks(void)
{
	union mhdr
		*p = allocs,
		*pprev = NULL;
	unsigned long n = 0;

	while (p != NULL)
	{
		passert(p->i.magic == LEAK_MAGIC);
		passert(pprev == p->i.newer);
		pprev = p;
		p = p->i.older;
		n++;
		if (p == NULL || pprev->i.name != p->i.name)
		{
			if (n != 1)
			    log("leak: %lu * %s", n, pprev->i.name);
			else
			    log("leak: %s", pprev->i.name);
			n = 0;
		}
	}
}

#else /* !LEAK_DETECTIVE */

void *alloc_bytes(size_t size, const char *name)
{
	void *p = malloc(size);

	if (p == NULL)
		exit_log("unable to malloc %lu bytes for %s",
			(unsigned long) size, name);
	memset(p, '\0', size);
	return p;
}

void *clone_bytes(const void *orig, size_t size, const char *name)
{
	void *p = malloc(size);

	if (p == NULL)
		exit_log("unable to malloc %lu bytes for %s",
			(unsigned long) size, name);
	memcpy(p, orig, size);
	return p;
}
#endif /* !LEAK_DETECTIVE */