buf_mmap.c

Go to the documentation of this file.

// SPDX-FileCopyrightText: 2009-2020 ret2libc <sirmy15@gmail.com>
// SPDX-License-Identifier: LGPL-3.0-only
 
#include <rz_util.h>
 
struct buf_mmap_user {
    const char *filename;
    int perm;
    int mode;
};
 
// "subclass"" of buf_bytes_priv
struct buf_mmap_priv {
    // NOTE: this needs to be first, so that bytes operations will work without changes
    struct buf_bytes_priv bytes_priv;
    RzMmap *mmap;
};
 
static inline struct buf_mmap_priv *get_priv_mmap(RzBuffer *b) {
    struct buf_mmap_priv *priv = (struct buf_mmap_priv *)b->priv;
    rz_warn_if_fail(priv);
    return priv;
}
 
static bool buf_mmap_init(RzBuffer *b, const void *user) {
    const struct buf_mmap_user *u = (const struct buf_mmap_user *)user;
    struct buf_mmap_priv *priv = RZ_NEW0(struct buf_mmap_priv);
    if (!priv) {
        return false;
    }
 
    priv->mmap = rz_file_mmap(u->filename, u->perm, u->mode, 0);
    if (!priv->mmap) {
        free(priv);
        return false;
    }
    priv->bytes_priv.buf = priv->mmap->buf;
    priv->bytes_priv.length = priv->mmap->len;
    priv->bytes_priv.offset = 0;
    b->priv = priv;
    b->fd = priv->mmap->fd;
    return true;
}
 
static bool buf_mmap_fini(RzBuffer *b) {
    struct buf_mmap_priv *priv = get_priv_mmap(b);
    rz_file_mmap_free(priv->mmap);
    RZ_FREE(b->priv);
    return true;
}
 
static bool buf_mmap_resize(RzBuffer *b, ut64 newsize) {
    struct buf_mmap_priv *priv = get_priv_mmap(b);
    if (newsize > priv->mmap->len) {
        ut8 *t = rz_file_mmap_resize(priv->mmap, newsize);
        if (!t) {
            return false;
        }
        priv->bytes_priv.buf = t;
    }
    priv->bytes_priv.length = newsize;
    return true;
}
 
static ut8 *buf_mmap_get_whole_buf(RzBuffer *b, ut64 *size) {
    struct buf_mmap_priv *priv = get_priv_mmap(b);
    if (size) {
        *size = priv->mmap->len;
    }
    return priv->mmap->buf;
}
 
static const RzBufferMethods buffer_mmap_methods = {
    .init = buf_mmap_init,
    .fini = buf_mmap_fini,
    .read = buf_bytes_read,
    .write = buf_bytes_write,
    .get_size = buf_bytes_get_size,
    .resize = buf_mmap_resize,
    .seek = buf_bytes_seek,
    .get_whole_buf = buf_mmap_get_whole_buf
};