io_gzip.c

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// SPDX-FileCopyrightText: 2008-2017 pancake <pancake@nopcode.org>
// SPDX-License-Identifier: LGPL-3.0-only
 
#include "rz_io.h"
#include "rz_lib.h"
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
 
typedef struct {
    ut8 *buf;
    ut32 size;
    ut64 offset;
} RzIOGzip;
 
static inline ut32 _io_malloc_sz(RzIODesc *desc) {
    if (!desc) {
        return 0;
    }
    RzIOGzip *mal = (RzIOGzip *)desc->data;
    return mal ? mal->size : 0;
}
 
static inline void _io_malloc_set_sz(RzIODesc *desc, ut32 sz) {
    if (!desc) {
        return;
    }
    RzIOGzip *mal = (RzIOGzip *)desc->data;
    if (mal) {
        mal->size = sz;
    }
}
 
static inline ut8 *_io_malloc_buf(RzIODesc *desc) {
    if (!desc) {
        return NULL;
    }
    RzIOGzip *mal = (RzIOGzip *)desc->data;
    return mal->buf;
}
 
static inline ut8 *_io_malloc_set_buf(RzIODesc *desc, ut8 *buf) {
    if (!desc) {
        return NULL;
    }
    RzIOGzip *mal = (RzIOGzip *)desc->data;
    return mal->buf = buf;
}
 
static inline ut64 _io_malloc_off(RzIODesc *desc) {
    if (!desc) {
        return 0;
    }
    RzIOGzip *mal = (RzIOGzip *)desc->data;
    return mal->offset;
}
 
static inline void _io_malloc_set_off(RzIODesc *desc, ut64 off) {
    if (!desc) {
        return;
    }
    RzIOGzip *mal = (RzIOGzip *)desc->data;
    mal->offset = off;
}
 
static int __write(RzIO *io, RzIODesc *fd, const ut8 *buf, int count) {
    if (!fd || !buf || count < 0 || !fd->data) {
        return -1;
    }
    if (_io_malloc_off(fd) > _io_malloc_sz(fd)) {
        return -1;
    }
    if (_io_malloc_off(fd) + count > _io_malloc_sz(fd)) {
        count -= (_io_malloc_off(fd) + count - _io_malloc_sz(fd));
    }
    if (count > 0) {
        memcpy(_io_malloc_buf(fd) + _io_malloc_off(fd), buf, count);
        _io_malloc_set_off(fd, _io_malloc_off(fd) + count);
        return count;
    }
    return -1;
}
 
static bool __resize(RzIO *io, RzIODesc *fd, ut64 count) {
    ut8 *new_buf = NULL;
    if (!fd || !fd->data || count == 0) {
        return false;
    }
    ut32 mallocsz = _io_malloc_sz(fd);
    if (_io_malloc_off(fd) > mallocsz) {
        return false;
    }
    new_buf = malloc(count);
    if (!new_buf) {
        return false;
    }
    memcpy(new_buf, _io_malloc_buf(fd), RZ_MIN(count, mallocsz));
    if (count > mallocsz) {
        memset(new_buf + mallocsz, 0, count - mallocsz);
    }
    free(_io_malloc_buf(fd));
    _io_malloc_set_buf(fd, new_buf);
    _io_malloc_set_sz(fd, count);
    return true;
}
 
static int __read(RzIO *io, RzIODesc *fd, ut8 *buf, int count) {
    memset(buf, 0xff, count);
    if (!fd || !fd->data) {
        return -1;
    }
    ut32 mallocsz = _io_malloc_sz(fd);
    if (_io_malloc_off(fd) > mallocsz) {
        return -1;
    }
    if (_io_malloc_off(fd) + count >= mallocsz) {
        count = mallocsz - _io_malloc_off(fd);
    }
    memcpy(buf, _io_malloc_buf(fd) + _io_malloc_off(fd), count);
    return count;
}
 
static int __close(RzIODesc *fd) {
    RzIOGzip *riom;
    if (!fd || !fd->data) {
        return -1;
    }
    riom = fd->data;
    RZ_FREE(riom->buf);
    RZ_FREE(fd->data);
    eprintf("TODO: Writing changes into gzipped files is not yet supported\n");
    return 0;
}
 
static ut64 __lseek(RzIO *io, RzIODesc *fd, ut64 offset, int whence) {
    ut64 rz_offset = offset;
    if (!fd || !fd->data) {
        return offset;
    }
    ut32 mallocsz = _io_malloc_sz(fd);
    switch (whence) {
    case SEEK_SET:
        rz_offset = (offset <= mallocsz) ? offset : mallocsz;
        break;
    case SEEK_CUR:
        rz_offset = (_io_malloc_off(fd) + offset <= mallocsz) ? _io_malloc_off(fd) + offset : mallocsz;
        break;
    case SEEK_END:
        rz_offset = _io_malloc_sz(fd);
        break;
    }
    _io_malloc_set_off(fd, rz_offset);
    return rz_offset;
}
 
static bool __plugin_open(RzIO *io, const char *pathname, bool many) {
    return (!strncmp(pathname, "gzip://", 7));
}
 
static RzIODesc *__open(RzIO *io, const char *pathname, int rw, int mode) {
    if (__plugin_open(io, pathname, 0)) {
        RzIOGzip *mal = RZ_NEW0(RzIOGzip);
        if (!mal) {
            return NULL;
        }
        size_t len;
        ut8 *data = (ut8 *)rz_file_slurp(pathname + 7, &len);
        int *size = (int *)&mal->size;
        mal->buf = rz_inflate(data, (int)len, NULL, size);
        if (mal->buf) {
            free(data);
            return rz_io_desc_new(io, &rz_io_plugin_gzip, pathname, rw, mode, mal);
        }
        free(data);
        eprintf("Cannot allocate (%s) %d byte(s)\n", pathname + 9, mal->size);
        free(mal);
    }
    return NULL;
}
 
RzIOPlugin rz_io_plugin_gzip = {
    .name = "gzip",
    .desc = "Read/write gzipped files",
    .license = "LGPL3",
    .uris = "gzip://",
    .open = __open,
    .close = __close,
    .read = __read,
    .check = __plugin_open,
    .lseek = __lseek,
    .write = __write,
    .resize = __resize,
};
 
#ifndef RZ_PLUGIN_INCORE
RZ_API RzLibStruct rizin_plugin = {
    .type = RZ_LIB_TYPE_IO,
    .data = &rz_io_plugin_gzip,
    .version = RZ_VERSION
};
#endif