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/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
* read_sparse_map_new.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#include "config.h"
#include "internal.h"
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
static int decode(const char *str, size_t len, size_t *out)
{
size_t count = 0;
*out = 0;
while (count < len && isdigit(*str)) {
if (SZ_MUL_OV(*out, 10, out))
return -1;
if (SZ_ADD_OV(*out, (*(str++) - '0'), out))
return -1;
++count;
}
if (count == 0 || count == len)
return 0;
return (*str == '\n') ? ((int)count + 1) : -1;
}
sparse_map_t *read_gnu_new_sparse(sqfs_istream_t *fp, tar_header_decoded_t *out)
{
sparse_map_t *last = NULL, *list = NULL, *ent = NULL;
size_t i, count, value;
char buffer[1024];
int diff, ret;
if (out->record_size < 512)
goto fail_format;
ret = sqfs_istream_read(fp, buffer, 512);
if (ret < 0) {
sqfs_perror(fp->get_filename(fp), "reading sparse list", ret);
goto fail;
}
if (ret < 512)
goto fail_format;
diff = decode(buffer, 512, &count);
if (diff <= 0)
goto fail_format;
out->record_size -= 512;
if (count == 0 || count > TAR_MAX_SPARSE_ENT)
goto fail_format;
for (i = 0; i < (count * 2); ++i) {
ret = decode(buffer + diff, 512 - diff, &value);
if (ret < 0)
goto fail_format;
if (ret > 0) {
diff += ret;
} else {
if (out->record_size < 512)
goto fail_format;
ret = sqfs_istream_read(fp, buffer + 512, 512);
if (ret < 0) {
sqfs_perror(fp->get_filename(fp),
"reading sparse list", ret);
goto fail;
}
if (ret < 512)
goto fail_format;
ret = decode(buffer + diff, 1024 - diff, &value);
if (ret <= 0)
goto fail_format;
memcpy(buffer, buffer + 512, 512);
diff = diff + ret - 512;
out->record_size -= 512;
}
if ((i & 0x01) == 0) {
ent = calloc(1, sizeof(*ent));
if (ent == NULL)
goto fail_errno;
if (list == NULL) {
list = last = ent;
} else {
last->next = ent;
last = ent;
}
ent->offset = value;
} else {
ent->count = value;
}
}
return list;
fail_errno:
perror("parsing GNU 1.0 style sparse file record");
goto fail;
fail_format:
fputs("Malformed GNU 1.0 style sparse file map.\n", stderr);
goto fail;
fail:
free_sparse_list(list);
return NULL;
}
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