/* $OpenBSD: monitor_mm.c,v 1.21 2015/02/06 23:21:59 millert Exp $ */
/*
* Copyright 2002 Niels Provos <provos@citi.umich.edu>
* All rights reserved.
*
* 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 AUTHOR ``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 AUTHOR 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 "includes.h"
#include <sys/types.h>
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
#include "openbsd-compat/sys-tree.h"
#include <errno.h>
#include <stdarg.h>
#include <stddef.h>
#ifdef HAVE_STDINT_H
#include <stdint.h>
#endif
#include <stdlib.h>
#include <string.h>
#include "xmalloc.h"
#include "ssh.h"
#include "log.h"
#include "monitor_mm.h"
static int
mm_compare(struct mm_share *a, struct mm_share *b)
{
ptrdiff_t diff = (char *)a->address - (char *)b->address;
if (diff == 0)
return (0);
else if (diff < 0)
return (-1);
else
return (1);
}
RB_GENERATE(mmtree, mm_share, next, mm_compare)
static struct mm_share *
mm_make_entry(struct mm_master *mm, struct mmtree *head,
void *address, size_t size)
{
struct mm_share *tmp, *tmp2;
if (mm->mmalloc == NULL)
tmp = xcalloc(1, sizeof(struct mm_share));
else
tmp = mm_xmalloc(mm->mmalloc, sizeof(struct mm_share));
tmp->address = address;
tmp->size = size;
tmp2 = RB_INSERT(mmtree, head, tmp);
if (tmp2 != NULL)
fatal("mm_make_entry(%p): double address %p->%p(%zu)",
mm, tmp2, address, size);
return (tmp);
}
/* Creates a shared memory area of a certain size */
struct mm_master *
mm_create(struct mm_master *mmalloc, size_t size)
{
void *address;
struct mm_master *mm;
if (mmalloc == NULL)
mm = xcalloc(1, sizeof(struct mm_master));
else
mm = mm_xmalloc(mmalloc, sizeof(struct mm_master));
/*
* If the memory map has a mm_master it can be completely
* shared including authentication between the child
* and the client.
*/
mm->mmalloc = mmalloc;
address = xmmap(size);
if (address == (void *)MAP_FAILED)
fatal("mmap(%zu): %s", size, strerror(errno));
mm->address = address;
mm->size = size;
RB_INIT(&mm->rb_free);
RB_INIT(&mm->rb_allocated);
mm_make_entry(mm, &mm->rb_free, address, size);
return (mm);
}
/* Frees either the allocated or the free list */
static void
mm_freelist(struct mm_master *mmalloc, struct mmtree *head)
{
struct mm_share *mms, *next;
for (mms = RB_ROOT(head); mms; mms = next) {
next = RB_NEXT(mmtree, head, mms);
RB_REMOVE(mmtree, head, mms);
if (mmalloc == NULL)
free(mms);
else
mm_free(mmalloc, mms);
}
}
/* Destroys a memory mapped area */
void
mm_destroy(struct mm_master *mm)
{
mm_freelist(mm->mmalloc, &mm->rb_free);
mm_freelist(mm->mmalloc, &mm->rb_allocated);
#ifdef HAVE_MMAP
if (munmap(mm->address, mm->size) == -1)
fatal("munmap(%p, %zu): %s", mm->address, mm->size,
strerror(errno));
#else
fatal("%s: UsePrivilegeSeparation=yes and Compression=yes not supported",
__func__);
#endif
if (mm->mmalloc == NULL)
free(mm);
else
mm_free(mm->mmalloc, mm);
}
void *
mm_xmalloc(struct mm_master *mm, size_t size)
{
void *address;
address = mm_malloc(mm, size);
if (address == NULL)
fatal("%s: mm_malloc(%zu)", __func__, size);
memset(address, 0, size);
return (address);
}
/* Allocates data from a memory mapped area */
void *
mm_malloc(struct mm_master *mm, size_t size)
{
struct mm_share *mms, *tmp;
if (size == 0)
fatal("mm_malloc: try to allocate 0 space");
if (size > SIZE_MAX - MM_MINSIZE + 1)
fatal("mm_malloc: size too big");
size = ((size + (MM_MINSIZE - 1)) / MM_MINSIZE) * MM_MINSIZE;
RB_FOREACH(mms, mmtree, &mm->rb_free) {
if (mms->size >= size)
break;
}
if (mms == NULL)
return (NULL);
/* Debug */
memset(mms->address, 0xd0, size);
tmp = mm_make_entry(mm, &mm->rb_allocated, mms->address, size);
/* Does not change order in RB tree */
mms->size -= size;
mms->address = (char *)mms->address + size;
if (mms->size == 0) {
RB_REMOVE(mmtree, &mm->rb_free, mms);
if (mm->mmalloc == NULL)
free(mms);
else
mm_free(mm->mmalloc, mms);
}
return (tmp->address);
}
/* Frees memory in a memory mapped area */
void
mm_free(struct mm_master *mm, void *address)
{
struct mm_share *mms, *prev, tmp;
tmp.address = address;
mms = RB_FIND(mmtree, &mm->rb_allocated, &tmp);
if (mms == NULL)
fatal("mm_free(%p): can not find %p", mm, address);
/* Debug */
memset(mms->address, 0xd0, mms->size);
/* Remove from allocated list and insert in free list */
RB_REMOVE(mmtree, &mm->rb_allocated, mms);
if (RB_INSERT(mmtree, &mm->rb_free, mms) != NULL)
fatal("mm_free(%p): double address %p", mm, address);
/* Find previous entry */
prev = mms;
if (RB_LEFT(prev, next)) {
prev = RB_LEFT(prev, next);
while (RB_RIGHT(prev, next))
prev = RB_RIGHT(prev, next);
} else {
if (RB_PARENT(prev, next) &&
(prev == RB_RIGHT(RB_PARENT(prev, next), next)))
prev = RB_PARENT(prev, next);
else {
while (RB_PARENT(prev, next) &&
(prev == RB_LEFT(RB_PARENT(prev, next), next)))
prev = RB_PARENT(prev, next);
prev = RB_PARENT(prev, next);
}
}
/* Check if range does not overlap */
if (prev != NULL && MM_ADDRESS_END(prev) > address)
fatal("mm_free: memory corruption: %p(%zu) > %p",
prev->address, prev->size, address);
/* See if we can merge backwards */
if (prev != NULL && MM_ADDRESS_END(prev) == address) {
prev->size += mms->size;
RB_REMOVE(mmtree, &mm->rb_free, mms);
if (mm->mmalloc == NULL)
free(mms);
else
mm_free(mm->mmalloc, mms);
} else
prev = mms;
if (prev == NULL)
return;
/* Check if we can merge forwards */
mms = RB_NEXT(mmtree, &mm->rb_free, prev);
if (mms == NULL)
return;
if (MM_ADDRESS_END(prev) > mms->address)
fatal("mm_free: memory corruption: %p < %p(%zu)",
mms->address, prev->address, prev->size);
if (MM_ADDRESS_END(prev) != mms->address)
return;
prev->size += mms->size;
RB_REMOVE(mmtree, &mm->rb_free, mms);
if (mm->mmalloc == NULL)
free(mms);
else
mm_free(mm->mmalloc, mms);
}
static void
mm_sync_list(struct mmtree *oldtree, struct mmtree *newtree,
struct mm_master *mm, struct mm_master *mmold)
{
struct mm_master *mmalloc = mm->mmalloc;
struct mm_share *mms, *new;
/* Sync free list */
RB_FOREACH(mms, mmtree, oldtree) {
/* Check the values */
mm_memvalid(mmold, mms, sizeof(struct mm_share));
mm_memvalid(mm, mms->address, mms->size);
new = mm_xmalloc(mmalloc, sizeof(struct mm_share));
memcpy(new, mms, sizeof(struct mm_share));
RB_INSERT(mmtree, newtree, new);
}
}
void
mm_share_sync(struct mm_master **pmm, struct mm_master **pmmalloc)
{
struct mm_master *mm;
struct mm_master *mmalloc;
struct mm_master *mmold;
struct mmtree rb_free, rb_allocated;
debug3("%s: Share sync", __func__);
mm = *pmm;
mmold = mm->mmalloc;
mm_memvalid(mmold, mm, sizeof(*mm));
mmalloc = mm_create(NULL, mm->size);
mm = mm_xmalloc(mmalloc, sizeof(struct mm_master));
memcpy(mm, *pmm, sizeof(struct mm_master));
mm->mmalloc = mmalloc;
rb_free = mm->rb_free;
rb_allocated = mm->rb_allocated;
RB_INIT(&mm->rb_free);
RB_INIT(&mm->rb_allocated);
mm_sync_list(&rb_free, &mm->rb_free, mm, mmold);
mm_sync_list(&rb_allocated, &mm->rb_allocated, mm, mmold);
mm_destroy(mmold);
*pmm = mm;
*pmmalloc = mmalloc;
debug3("%s: Share sync end", __func__);
}
void
mm_memvalid(struct mm_master *mm, void *address, size_t size)
{
void *end = (char *)address + size;
if (address < mm->address)
fatal("mm_memvalid: address too small: %p", address);
if (end < address)
fatal("mm_memvalid: end < address: %p < %p", end, address);
if (end > MM_ADDRESS_END(mm))
fatal("mm_memvalid: address too large: %p", address);
}
