/
fmap.c
1109 lines (966 loc) · 32.8 KB
/
fmap.c
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/*
* Copyright (C) 2013-2020 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
* Copyright (C) 2009-2013 Sourcefire, Inc.
*
* Authors: aCaB <acab@clamav.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
/* an mmap "replacement" which doesn't suck */
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include <stdint.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <libgen.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef ANONYMOUS_MAP
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
#endif
#include <errno.h>
#ifdef C_LINUX
#include <pthread.h>
#endif
#include "clamav.h"
#include "others.h"
#include "str.h"
#define FM_MASK_COUNT 0x3fffffff
#define FM_MASK_PAGED 0x40000000
#define FM_MASK_SEEN 0x80000000
#define FM_MASK_LOCKED FM_MASK_SEEN
/* 2 high bits:
00 - not seen - not paged - N/A
01 - N/A - paged - not locked
10 - seen - not paged - N/A
11 - N/A - paged - locked
*/
/* FIXME: tune this stuff */
#define UNPAGE_THRSHLD_LO 4 * 1024 * 1024
#define UNPAGE_THRSHLD_HI 8 * 1024 * 1024
#define READAHEAD_PAGES 8
#if defined(ANONYMOUS_MAP) && defined(C_LINUX) && defined(CL_THREAD_SAFE)
/*
WORKAROUND
Relieve some stress on mmap_sem.
When mmap_sem is heavily hammered, the scheduler
tends to fail to wake us up properly.
*/
pthread_mutex_t fmap_mutex = PTHREAD_MUTEX_INITIALIZER;
#define fmap_lock pthread_mutex_lock(&fmap_mutex)
#define fmap_unlock pthread_mutex_unlock(&fmap_mutex);
#else
#define fmap_lock
#define fmap_unlock
#endif
#ifndef MADV_DONTFORK
#define MADV_DONTFORK 0
#endif
#define fmap_bitmap (m->bitmap)
static inline unsigned int fmap_align_items(unsigned int sz, unsigned int al);
static inline unsigned int fmap_align_to(unsigned int sz, unsigned int al);
static inline unsigned int fmap_which_page(fmap_t *m, size_t at);
static const void *handle_need(fmap_t *m, size_t at, size_t len, int lock);
static void handle_unneed_off(fmap_t *m, size_t at, size_t len);
static const void *handle_need_offstr(fmap_t *m, size_t at, size_t len_hint);
static const void *handle_gets(fmap_t *m, char *dst, size_t *at, size_t max_len);
static void unmap_mmap(fmap_t *m);
static void unmap_malloc(fmap_t *m);
#ifndef _WIN32
/* pread proto here in order to avoid the use of XOPEN and BSD_SOURCE
which may in turn prevent some mmap constants to be defined */
ssize_t pread(int fd, void *buf, size_t count, off_t offset);
/* vvvvv POSIX STUFF BELOW vvvvv */
static off_t pread_cb(void *handle, void *buf, size_t count, off_t offset)
{
return pread((int)(ssize_t)handle, buf, count, offset);
}
fmap_t *fmap_check_empty(int fd, off_t offset, size_t len, int *empty, const char *name)
{
STATBUF st;
fmap_t *m = NULL;
*empty = 0;
if (FSTAT(fd, &st)) {
cli_warnmsg("fmap: fstat failed\n");
return NULL;
}
if (!len) len = st.st_size - offset; /* bound checked later */
if (!len) {
cli_dbgmsg("fmap: attempted void mapping\n");
*empty = 1;
return NULL;
}
if (!CLI_ISCONTAINED(0, st.st_size, offset, len)) {
cli_warnmsg("fmap: attempted oof mapping\n");
return NULL;
}
m = cl_fmap_open_handle((void *)(ssize_t)fd, offset, len, pread_cb, 1);
if (!m)
return NULL;
m->mtime = st.st_mtime;
if (NULL != name) {
m->name = cli_strdup(name);
if (NULL == m->name) {
funmap(m);
return NULL;
}
}
return m;
}
#else
/* vvvvv WIN32 STUFF BELOW vvvvv */
static void unmap_win32(fmap_t *m)
{
if (NULL != m) {
if (NULL != m->data) {
UnmapViewOfFile(m->data);
}
if (NULL != m->mh) {
CloseHandle(m->mh);
}
if (NULL != m->name) {
free(m->name);
}
free((void *)m);
}
}
fmap_t *fmap_check_empty(int fd, off_t offset, size_t len, int *empty, const char *name)
{ /* WIN32 */
unsigned int pages, mapsz;
int pgsz = cli_getpagesize();
STATBUF st;
fmap_t *m = NULL;
const void *data;
HANDLE fh;
HANDLE mh;
*empty = 0;
if (FSTAT(fd, &st)) {
cli_warnmsg("fmap: fstat failed\n");
return NULL;
}
if (offset < 0 || offset != fmap_align_to(offset, pgsz)) {
cli_warnmsg("fmap: attempted mapping with unaligned offset\n");
return NULL;
}
if (!len) len = st.st_size - offset; /* bound checked later */
if (!len) {
cli_dbgmsg("fmap: attempted void mapping\n");
*empty = 1;
return NULL;
}
if (!CLI_ISCONTAINED(0, st.st_size, offset, len)) {
cli_warnmsg("fmap: attempted oof mapping\n");
return NULL;
}
pages = fmap_align_items(len, pgsz);
if ((fh = (HANDLE)_get_osfhandle(fd)) == INVALID_HANDLE_VALUE) {
cli_errmsg("fmap: cannot get a valid handle for descriptor %d\n", fd);
return NULL;
}
if (!(mh = CreateFileMapping(fh, NULL, PAGE_READONLY, (DWORD)((len >> 31) >> 1), (DWORD)len, NULL))) {
cli_errmsg("fmap: cannot create a map of descriptor %d\n", fd);
return NULL;
}
if (!(data = MapViewOfFile(mh, FILE_MAP_READ, (DWORD)((offset >> 31) >> 1), (DWORD)(offset), len))) {
cli_errmsg("fmap: cannot map file descriptor %d\n", fd);
CloseHandle(mh);
return NULL;
}
if (!(m = cl_fmap_open_memory(data, len))) {
cli_errmsg("fmap: cannot allocate fmap_t\n", fd);
UnmapViewOfFile(data);
CloseHandle(mh);
return NULL;
}
m->handle = (void *)(size_t)fd;
m->handle_is_fd = 1; /* This is probably(?) needed so `fmap_fd()` can return the file descriptor. */
m->fh = fh;
m->mh = mh;
m->unmap = unmap_win32;
if (NULL != name) {
m->name = cli_strdup(name);
if (NULL == m->name) {
funmap(m);
return NULL;
}
}
return m;
}
#endif /* _WIN32 */
/* vvvvv SHARED STUFF BELOW vvvvv */
fmap_t *fmap_duplicate(cl_fmap_t *map, size_t offset, size_t length, const char *name)
{
cl_error_t status = CL_ERROR;
cl_fmap_t *duplicate_map = NULL;
if (NULL == map) {
cli_warnmsg("fmap_duplicate: map is NULL!\n");
goto done;
}
duplicate_map = cli_malloc(sizeof(cl_fmap_t));
if (!duplicate_map) {
cli_warnmsg("fmap_duplicate: map allocation failed\n");
goto done;
}
/* Duplicate the state of the original map */
memcpy(duplicate_map, map, sizeof(cl_fmap_t));
if (offset > map->len) {
/* invalid offset, exceeds length of map */
cli_warnmsg("fmap_duplicate: requested offset exceeds end of map\n");
goto done;
}
if (offset > 0 || length < map->len) {
/* Caller requested a window into the current map, not the whole map */
unsigned char hash[16] = {'\0'};
/* Set the new nested offset and (nested) length for the new map */
/* can't change offset because then we'd have to discard/move cached
* data, instead use nested_offset to reuse the already cached data */
duplicate_map->nested_offset += offset;
duplicate_map->len = MIN(length, map->len - offset);
if (!CLI_ISCONTAINED2(map->nested_offset, map->len,
duplicate_map->nested_offset, duplicate_map->len)) {
size_t len1, len2;
len1 = map->nested_offset + map->len;
len2 = duplicate_map->nested_offset + duplicate_map->len;
cli_warnmsg("fmap_duplicate: internal map error: %zu, %zu; %zu, %zu\n",
map->nested_offset, len1,
duplicate_map->offset, len2);
}
/* Calculate the fmap hash to be used by the FP check later */
if (CL_SUCCESS != fmap_get_MD5(hash, duplicate_map)) {
cli_warnmsg("fmap_duplicate: failed to get fmap MD5\n");
goto done;
}
memcpy(duplicate_map->maphash, hash, 16);
}
if (NULL != name) {
duplicate_map->name = cli_strdup(name);
if (NULL == duplicate_map->name) {
free(duplicate_map);
return NULL;
}
} else {
duplicate_map->name = NULL;
}
status = CL_SUCCESS;
done:
if (CL_SUCCESS != status) {
if (NULL != duplicate_map) {
free(duplicate_map);
duplicate_map = NULL;
}
}
return duplicate_map;
}
void free_duplicate_fmap(cl_fmap_t *map)
{
if (NULL != map) {
if (NULL != map->name) {
free(map->name);
map->name = NULL;
}
free(map);
}
}
static void unmap_handle(fmap_t *m)
{
if (NULL != m) {
if (NULL != m->data) {
if (m->aging) {
unmap_mmap(m);
} else {
free((void *)m->data);
}
m->data = NULL;
}
if (NULL != m->bitmap) {
free(m->bitmap);
m->bitmap = NULL;
}
if (NULL != m->name) {
free(m->name);
}
free((void *)m);
}
}
extern cl_fmap_t *cl_fmap_open_handle(void *handle, size_t offset, size_t len,
clcb_pread pread_cb, int use_aging)
{
cl_error_t status = CL_EMEM;
unsigned int pages;
size_t mapsz, bitmap_size;
cl_fmap_t *m = NULL;
int pgsz = cli_getpagesize();
unsigned char hash[16] = {'\0'};
if ((off_t)offset < 0 || offset != fmap_align_to(offset, pgsz)) {
cli_warnmsg("fmap: attempted mapping with unaligned offset\n");
goto done;
}
if (!len) {
cli_dbgmsg("fmap: attempted void mapping\n");
goto done;
}
if (offset >= len) {
cli_warnmsg("fmap: attempted oof mapping\n");
goto done;
}
pages = fmap_align_items(len, pgsz);
bitmap_size = pages * sizeof(uint32_t);
mapsz = pages * pgsz;
m = cli_calloc(1, sizeof(fmap_t));
if (!m) {
cli_warnmsg("fmap: map header allocation failed\n");
goto done;
}
m->bitmap = cli_calloc(1, bitmap_size);
if (!m->bitmap) {
cli_warnmsg("fmap: map header allocation failed\n");
goto done;
}
#ifndef ANONYMOUS_MAP
use_aging = 0;
#endif
#ifdef ANONYMOUS_MAP
if (use_aging) {
fmap_lock;
if ((m->data = (fmap_t *)mmap(NULL,
mapsz,
PROT_READ | PROT_WRITE, MAP_PRIVATE | /* FIXME: MAP_POPULATE is ~8% faster but more memory intensive */ ANONYMOUS_MAP,
-1,
0)) == MAP_FAILED) {
m->data = NULL;
} else {
#if HAVE_MADVISE
madvise((void *)m->data, mapsz, MADV_RANDOM | MADV_DONTFORK);
#endif /* madvise */
}
fmap_unlock;
}
#endif /* ANONYMOUS_MAP */
if (!use_aging) {
m->data = (fmap_t *)cli_malloc(mapsz);
}
if (!m->data) {
cli_warnmsg("fmap: map allocation failed\n");
goto done;
}
m->handle = handle;
m->pread_cb = pread_cb;
m->aging = use_aging;
m->offset = offset;
m->nested_offset = 0;
m->len = len; /* m->nested_offset + m->len = m->real_len */
m->real_len = len;
m->pages = pages;
m->pgsz = pgsz;
m->paged = 0;
m->dont_cache_flag = 0;
m->unmap = unmap_handle;
m->need = handle_need;
m->need_offstr = handle_need_offstr;
m->gets = handle_gets;
m->unneed_off = handle_unneed_off;
m->handle_is_fd = 1;
/* Calculate the fmap hash to be used by the FP check later */
if (CL_SUCCESS != fmap_get_MD5(hash, m)) {
cli_warnmsg("fmap: failed to get MD5\n");
goto done;
}
memcpy(m->maphash, hash, 16);
status = CL_SUCCESS;
done:
if (CL_SUCCESS != status) {
unmap_handle(m);
m = NULL;
}
return m;
}
static void fmap_aging(fmap_t *m)
{
#ifdef ANONYMOUS_MAP
if (!m->aging) return;
if (m->paged * m->pgsz > UNPAGE_THRSHLD_HI) { /* we alloc'd too much */
unsigned int i, avail = 0, freeme[2048], maxavail = MIN(sizeof(freeme) / sizeof(*freeme), m->paged - UNPAGE_THRSHLD_LO / m->pgsz) - 1;
for (i = 0; i < m->pages; i++) {
uint32_t s = fmap_bitmap[i];
if ((s & (FM_MASK_PAGED | FM_MASK_LOCKED)) == FM_MASK_PAGED) {
/* page is paged and not locked: dec age */
if (s & FM_MASK_COUNT) fmap_bitmap[i]--;
/* and make it available for unpaging */
if (!avail) {
freeme[0] = i;
avail++;
} else {
/* Insert sort onto a stack'd array - same performance as quickselect */
unsigned int insert_to = MIN(maxavail, avail) - 1, age = fmap_bitmap[i] & FM_MASK_COUNT;
if (avail <= maxavail || (fmap_bitmap[freeme[maxavail]] & FM_MASK_COUNT) > age) {
while ((fmap_bitmap[freeme[insert_to]] & FM_MASK_COUNT) > age) {
freeme[insert_to + 1] = freeme[insert_to];
if (!insert_to--) break;
}
freeme[insert_to + 1] = i;
if (avail <= maxavail) avail++;
}
}
}
}
if (avail) { /* at least one page is paged and not locked */
char *lastpage = NULL;
char *firstpage = NULL;
for (i = 0; i < avail; i++) {
char *pptr = (char *)m->data + freeme[i] * m->pgsz;
/* we mark the page as seen */
fmap_bitmap[freeme[i]] = FM_MASK_SEEN;
/* and we mmap the page over so the kernel knows there's nothing good in there */
/* reduce number of mmap calls: if pages are adjacent only do 1 mmap call */
if (lastpage && pptr == lastpage) {
lastpage = pptr + m->pgsz;
continue;
}
if (!lastpage) {
firstpage = pptr;
lastpage = pptr + m->pgsz;
continue;
}
fmap_lock;
if (mmap(firstpage, lastpage - firstpage, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_PRIVATE | ANONYMOUS_MAP, -1, 0) == MAP_FAILED)
cli_dbgmsg("fmap_aging: kernel hates you\n");
fmap_unlock;
firstpage = pptr;
lastpage = pptr + m->pgsz;
}
if (lastpage) {
fmap_lock;
if (mmap(firstpage, lastpage - firstpage, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_PRIVATE | ANONYMOUS_MAP, -1, 0) == MAP_FAILED)
cli_dbgmsg("fmap_aging: kernel hates you\n");
fmap_unlock;
}
m->paged -= avail;
}
}
#endif
}
static int fmap_readpage(fmap_t *m, uint64_t first_page, uint32_t count, uint32_t lock_count)
{
size_t readsz = 0, eintr_off;
char *pptr = NULL, errtxt[256];
uint32_t sbitmap;
uint64_t i, page = first_page, force_read = 0;
if ((size_t)(m->real_len) > (size_t)(UINT_MAX)) {
cli_dbgmsg("fmap_readage: size of file exceeds total prefaultible page size (unpacked file is too large)\n");
return 1;
}
fmap_lock;
for (i = 0; i < count; i++) { /* prefault */
/* Not worth checking if the page is already paged, just ping each */
/* Also not worth reusing the loop below */
volatile char faultme;
faultme = ((char *)m->data)[(first_page + i) * m->pgsz];
}
fmap_unlock;
for (i = 0; i <= count; i++, page++) {
int lock;
if (lock_count) {
lock_count--;
lock = 1;
} else
lock = 0;
if (i == count) {
/* we count one page too much to flush pending reads */
if (!pptr) return 0; /* if we have any */
force_read = 1;
} else if ((sbitmap = fmap_bitmap[page]) & FM_MASK_PAGED) {
/* page already paged */
if (lock) {
/* we want locking */
if (sbitmap & FM_MASK_LOCKED) {
/* page already locked */
sbitmap &= FM_MASK_COUNT;
if (sbitmap == FM_MASK_COUNT) { /* lock count already at max: fial! */
cli_errmsg("fmap_readpage: lock count exceeded\n");
return 1;
}
/* acceptable lock count: inc lock count */
fmap_bitmap[page]++;
} else /* page not currently locked: set lock count = 1 */
fmap_bitmap[page] = 1 | FM_MASK_LOCKED | FM_MASK_PAGED;
} else {
/* we don't want locking */
if (!(sbitmap & FM_MASK_LOCKED)) {
/* page is not locked: we reset aging to max */
fmap_bitmap[page] = FM_MASK_PAGED | FM_MASK_COUNT;
}
}
if (!pptr) continue;
force_read = 1;
}
if (force_read) {
/* we have some pending reads to perform */
if (m->handle_is_fd) {
unsigned int j;
int _fd = (int)(ptrdiff_t)m->handle;
for (j = first_page; j < page; j++) {
if (fmap_bitmap[j] & FM_MASK_SEEN) {
/* page we've seen before: check mtime */
STATBUF st;
if (FSTAT(_fd, &st)) {
cli_strerror(errno, errtxt, sizeof(errtxt));
cli_warnmsg("fmap_readpage: fstat failed: %s\n", errtxt);
return 1;
}
if (m->mtime != st.st_mtime) {
cli_warnmsg("fmap_readpage: file changed as we read it\n");
return 1;
}
break;
}
}
}
eintr_off = 0;
while (readsz) {
ssize_t got;
off_t target_offset = eintr_off + m->offset + (first_page * m->pgsz);
got = m->pread_cb(m->handle, pptr, readsz, target_offset);
if (got < 0 && errno == EINTR)
continue;
if (got > 0) {
pptr += got;
eintr_off += got;
readsz -= got;
continue;
}
if (got < 0) {
cli_strerror(errno, errtxt, sizeof(errtxt));
cli_errmsg("fmap_readpage: pread error: %s\n", errtxt);
} else {
cli_warnmsg("fmap_readpage: pread fail: asked for %lu bytes @ offset %lu, got %lu\n", (long unsigned int)readsz, (long unsigned int)target_offset, (long unsigned int)got);
}
return 1;
}
pptr = NULL;
force_read = 0;
readsz = 0;
continue;
}
/* page is not already paged */
if (!pptr) {
/* set a new start for pending reads if we don't have one */
pptr = (char *)m->data + page * m->pgsz;
first_page = page;
}
if ((page == m->pages - 1) && (m->real_len % m->pgsz))
readsz += m->real_len % m->pgsz;
else
readsz += m->pgsz;
if (lock) /* lock requested: set paged, lock page and set lock count to 1 */
fmap_bitmap[page] = FM_MASK_PAGED | FM_MASK_LOCKED | 1;
else /* no locking: set paged and set aging to max */
fmap_bitmap[page] = FM_MASK_PAGED | FM_MASK_COUNT;
m->paged++;
}
return 0;
}
static const void *handle_need(fmap_t *m, size_t at, size_t len, int lock)
{
uint64_t first_page, last_page, lock_count;
char *ret;
if (!len)
return NULL;
at += m->nested_offset;
if (!CLI_ISCONTAINED(0, m->real_len, at, len))
return NULL;
fmap_aging(m);
first_page = fmap_which_page(m, at);
last_page = fmap_which_page(m, at + len - 1);
lock_count = (lock != 0) * (last_page - first_page + 1);
#ifdef READAHED_PAGES
last_page += READAHED_PAGES;
if (last_page >= m->pages) last_page = m->pages - 1;
#endif
if (fmap_readpage(m, first_page, last_page - first_page + 1, lock_count))
return NULL;
ret = (char *)m->data + at;
return (void *)ret;
}
static void fmap_unneed_page(fmap_t *m, unsigned int page)
{
uint32_t s = fmap_bitmap[page];
if ((s & (FM_MASK_PAGED | FM_MASK_LOCKED)) == (FM_MASK_PAGED | FM_MASK_LOCKED)) {
/* page is paged and locked: check lock count */
s &= FM_MASK_COUNT;
if (s > 1) /* locked more than once: dec lock count */
fmap_bitmap[page]--;
else if (s == 1) /* only one lock left: unlock and begin aging */
fmap_bitmap[page] = FM_MASK_COUNT | FM_MASK_PAGED;
else
cli_errmsg("fmap_unneed: inconsistent map state\n");
return;
}
cli_warnmsg("fmap_unneed: unneed on a unlocked page\n");
return;
}
static void handle_unneed_off(fmap_t *m, size_t at, size_t len)
{
unsigned int i, first_page, last_page;
if (!m->aging) return;
if (!len) {
cli_warnmsg("fmap_unneed: attempted void unneed\n");
return;
}
at += m->nested_offset;
if (!CLI_ISCONTAINED(0, m->real_len, at, len)) {
cli_warnmsg("fmap: attempted oof unneed\n");
return;
}
first_page = fmap_which_page(m, at);
last_page = fmap_which_page(m, at + len - 1);
for (i = first_page; i <= last_page; i++) {
fmap_unneed_page(m, i);
}
}
static void unmap_mmap(fmap_t *m)
{
#ifdef ANONYMOUS_MAP
size_t len = m->pages * m->pgsz;
fmap_lock;
if (munmap((void *)m->data, len) == -1) /* munmap() failed */
cli_warnmsg("funmap: unable to unmap memory segment at address: %p with length: %zu\n", (void *)m->data, len);
fmap_unlock;
#endif
}
static void unmap_malloc(fmap_t *m)
{
if (NULL != m) {
if (NULL != m->name) {
free(m->name);
}
free((void *)m);
}
}
static const void *handle_need_offstr(fmap_t *m, size_t at, size_t len_hint)
{
unsigned int i, first_page, last_page;
void *ptr = (void *)((char *)m->data + at);
if (!len_hint || len_hint > m->real_len - at)
len_hint = m->real_len - at;
if (!CLI_ISCONTAINED(0, m->real_len, at, len_hint))
return NULL;
fmap_aging(m);
first_page = fmap_which_page(m, at);
last_page = fmap_which_page(m, at + len_hint - 1);
for (i = first_page; i <= last_page; i++) {
char *thispage = (char *)m->data + i * m->pgsz;
unsigned int scanat, scansz;
if (fmap_readpage(m, i, 1, 1)) {
last_page = i - 1;
break;
}
if (i == first_page) {
scanat = at % m->pgsz;
scansz = MIN(len_hint, m->pgsz - scanat);
} else {
scanat = 0;
scansz = MIN(len_hint, m->pgsz);
}
len_hint -= scansz;
if (memchr(&thispage[scanat], 0, scansz))
return ptr;
}
for (i = first_page; i <= last_page; i++)
fmap_unneed_page(m, i);
return NULL;
}
static const void *handle_gets(fmap_t *m, char *dst, size_t *at, size_t max_len)
{
unsigned int i, first_page, last_page;
char *src = (void *)((char *)m->data + *at);
char *endptr = NULL;
size_t len = MIN(max_len - 1, m->real_len - *at);
size_t fullen = len;
if (!len || !CLI_ISCONTAINED(0, m->real_len, *at, len))
return NULL;
fmap_aging(m);
first_page = fmap_which_page(m, *at);
last_page = fmap_which_page(m, *at + len - 1);
for (i = first_page; i <= last_page; i++) {
char *thispage = (char *)m->data + i * m->pgsz;
unsigned int scanat, scansz;
if (fmap_readpage(m, i, 1, 0))
return NULL;
if (i == first_page) {
scanat = *at % m->pgsz;
scansz = MIN(len, m->pgsz - scanat);
} else {
scanat = 0;
scansz = MIN(len, m->pgsz);
}
len -= scansz;
if ((endptr = memchr(&thispage[scanat], '\n', scansz))) {
endptr++;
break;
}
}
if (endptr) {
memcpy(dst, src, endptr - src);
dst[endptr - src] = '\0';
*at += endptr - src;
} else {
memcpy(dst, src, fullen);
dst[fullen] = '\0';
*at += fullen;
}
return dst;
}
/* vvvvv MEMORY STUFF BELOW vvvvv */
static const void *mem_need(fmap_t *m, size_t at, size_t len, int lock);
static void mem_unneed_off(fmap_t *m, size_t at, size_t len);
static const void *mem_need_offstr(fmap_t *m, size_t at, size_t len_hint);
static const void *mem_gets(fmap_t *m, char *dst, size_t *at, size_t max_len);
fmap_t *fmap_open_memory(const void *start, size_t len, const char *name)
{
unsigned char hash[16] = {'\0'};
int pgsz = cli_getpagesize();
cl_fmap_t *m = cli_calloc(1, sizeof(*m));
if (!m) {
cli_warnmsg("fmap: map allocation failed\n");
return NULL;
}
m->data = start;
m->len = len;
m->real_len = len;
m->pgsz = pgsz;
m->pages = fmap_align_items(len, pgsz);
m->unmap = unmap_malloc;
m->need = mem_need;
m->need_offstr = mem_need_offstr;
m->gets = mem_gets;
m->unneed_off = mem_unneed_off;
if (NULL != name) {
m->name = cli_strdup(name);
if (NULL == m->name) {
free(m);
return NULL;
}
}
/* Calculate the fmap hash to be used by the FP check later */
if (CL_SUCCESS != fmap_get_MD5(hash, m)) {
if (NULL != m->name) {
free(m->name);
}
free(m);
return NULL;
}
memcpy(m->maphash, hash, 16);
return m;
}
extern cl_fmap_t *cl_fmap_open_memory(const void *start, size_t len)
{
return (cl_fmap_t *)fmap_open_memory(start, len, NULL);
}
static const void *mem_need(fmap_t *m, size_t at, size_t len, int lock)
{ /* WIN32 */
UNUSEDPARAM(lock);
if (!len) {
return NULL;
}
at += m->nested_offset;
if (!CLI_ISCONTAINED(0, m->real_len, at, len)) {
return NULL;
}
return (void *)((char *)m->data + at);
}
static void mem_unneed_off(fmap_t *m, size_t at, size_t len)
{
UNUSEDPARAM(m);
UNUSEDPARAM(at);
UNUSEDPARAM(len);
}
static const void *mem_need_offstr(fmap_t *m, size_t at, size_t len_hint)
{
char *ptr = (char *)m->data + at;
if (!len_hint || len_hint > m->real_len - at)
len_hint = m->real_len - at;
if (!CLI_ISCONTAINED(0, m->real_len, at, len_hint))
return NULL;
if (memchr(ptr, 0, len_hint))
return (void *)ptr;
return NULL;
}
static const void *mem_gets(fmap_t *m, char *dst, size_t *at, size_t max_len)
{
char *src = (char *)m->data + *at, *endptr = NULL;
size_t len = MIN(max_len - 1, m->real_len - *at);
if (!len || !CLI_ISCONTAINED(0, m->real_len, *at, len))
return NULL;
if ((endptr = memchr(src, '\n', len))) {
endptr++;
memcpy(dst, src, endptr - src);
dst[endptr - src] = '\0';
*at += endptr - src;
} else {
memcpy(dst, src, len);
dst[len] = '\0';
*at += len;
}
return dst;
}
fmap_t *fmap(int fd, off_t offset, size_t len, const char *name)
{
int unused;
return fmap_check_empty(fd, offset, len, &unused, name);
}
static inline unsigned int fmap_align_items(unsigned int sz, unsigned int al)
{
return sz / al + (sz % al != 0);
}
static inline unsigned int fmap_align_to(unsigned int sz, unsigned int al)
{
return al * fmap_align_items(sz, al);
}
static inline unsigned int fmap_which_page(fmap_t *m, size_t at)
{
return at / m->pgsz;
}
cl_error_t fmap_dump_to_file(fmap_t *map, const char *filepath, const char *tmpdir, char **outname, int *outfd, size_t start_offset, size_t end_offset)
{
cl_error_t ret = CL_EARG;
char *filebase = NULL;
char *prefix = NULL;
char *tmpname = NULL;
int tmpfd = -1;
size_t pos = 0, len = 0, bytes_remaining = 0, write_size = 0;
if ((start_offset > map->real_len) || (end_offset < start_offset)) {
cli_dbgmsg("fmap_dump_to_file: Invalid offset arguments: start %zu, end %zu\n", start_offset, end_offset);
return ret;
}
pos = start_offset;
end_offset = MIN(end_offset, map->real_len);
bytes_remaining = end_offset - start_offset;
/* Create a filename prefix that includes the original filename, if available */
if (filepath != NULL) {
if (CL_SUCCESS != cli_basename(filepath, strlen(filepath), &filebase)) {
cli_dbgmsg("fmap_dump_to_file: Unable to determine basename from filepath.\n");
} else if ((start_offset != 0) && (end_offset != map->real_len)) {
/* If we're only dumping a portion of the file, inlcude the offsets in the prefix,...
* e.g. tmp filename will become something like: filebase.500-1200.<randhex> */
uint32_t prefix_len = strlen(filebase) + 1 + SIZE_T_CHARLEN + 1 + SIZE_T_CHARLEN + 1;
prefix = malloc(prefix_len);
if (NULL == prefix) {
cli_errmsg("fmap_dump_to_file: Failed to allocate memory for tempfile prefix.\n");
if (NULL != filebase)
free(filebase);
return CL_EMEM;
}
snprintf(prefix, prefix_len, "%s.%zu-%zu", filebase, start_offset, end_offset);
free(filebase);
filebase = NULL;
} else {
/* Else if we're dumping the whole thing, use the filebase as the prefix */