cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

vnc-enc-zlib.c (4583B)

      1/*
      2 * QEMU VNC display driver: zlib encoding
      3 *
      4 * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
      5 * Copyright (C) 2006 Fabrice Bellard
      6 * Copyright (C) 2009 Red Hat, Inc
      7 *
      8 * Permission is hereby granted, free of charge, to any person obtaining a copy
      9 * of this software and associated documentation files (the "Software"), to deal
     10 * in the Software without restriction, including without limitation the rights
     11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     12 * copies of the Software, and to permit persons to whom the Software is
     13 * furnished to do so, subject to the following conditions:
     14 *
     15 * The above copyright notice and this permission notice shall be included in
     16 * all copies or substantial portions of the Software.
     17 *
     18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
     21 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
     24 * THE SOFTWARE.
     25 */
     26
     27#include "qemu/osdep.h"
     28#include "vnc.h"
     29
     30#define ZALLOC_ALIGNMENT 16
     31
     32void *vnc_zlib_zalloc(void *x, unsigned items, unsigned size)
     33{
     34    void *p;
     35
     36    size *= items;
     37    size = (size + ZALLOC_ALIGNMENT - 1) & ~(ZALLOC_ALIGNMENT - 1);
     38
     39    p = g_malloc0(size);
     40
     41    return (p);
     42}
     43
     44void vnc_zlib_zfree(void *x, void *addr)
     45{
     46    g_free(addr);
     47}
     48
     49static void vnc_zlib_start(VncState *vs)
     50{
     51    buffer_reset(&vs->zlib.zlib);
     52
     53    // make the output buffer be the zlib buffer, so we can compress it later
     54    vs->zlib.tmp = vs->output;
     55    vs->output = vs->zlib.zlib;
     56}
     57
     58static int vnc_zlib_stop(VncState *vs)
     59{
     60    z_streamp zstream = &vs->zlib.stream;
     61    int previous_out;
     62
     63    // switch back to normal output/zlib buffers
     64    vs->zlib.zlib = vs->output;
     65    vs->output = vs->zlib.tmp;
     66
     67    // compress the zlib buffer
     68
     69    // initialize the stream
     70    // XXX need one stream per session
     71    if (zstream->opaque != vs) {
     72        int err;
     73
     74        VNC_DEBUG("VNC: initializing zlib stream\n");
     75        VNC_DEBUG("VNC: opaque = %p | vs = %p\n", zstream->opaque, vs);
     76        zstream->zalloc = vnc_zlib_zalloc;
     77        zstream->zfree = vnc_zlib_zfree;
     78
     79        err = deflateInit2(zstream, vs->tight->compression, Z_DEFLATED,
     80                           MAX_WBITS,
     81                           MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
     82
     83        if (err != Z_OK) {
     84            fprintf(stderr, "VNC: error initializing zlib\n");
     85            return -1;
     86        }
     87
     88        vs->zlib.level = vs->tight->compression;
     89        zstream->opaque = vs;
     90    }
     91
     92    if (vs->tight->compression != vs->zlib.level) {
     93        if (deflateParams(zstream, vs->tight->compression,
     94                          Z_DEFAULT_STRATEGY) != Z_OK) {
     95            return -1;
     96        }
     97        vs->zlib.level = vs->tight->compression;
     98    }
     99
    100    // reserve memory in output buffer
    101    buffer_reserve(&vs->output, vs->zlib.zlib.offset + 64);
    102
    103    // set pointers
    104    zstream->next_in = vs->zlib.zlib.buffer;
    105    zstream->avail_in = vs->zlib.zlib.offset;
    106    zstream->next_out = vs->output.buffer + vs->output.offset;
    107    zstream->avail_out = vs->output.capacity - vs->output.offset;
    108    previous_out = zstream->avail_out;
    109    zstream->data_type = Z_BINARY;
    110
    111    // start encoding
    112    if (deflate(zstream, Z_SYNC_FLUSH) != Z_OK) {
    113        fprintf(stderr, "VNC: error during zlib compression\n");
    114        return -1;
    115    }
    116
    117    vs->output.offset = vs->output.capacity - zstream->avail_out;
    118    return previous_out - zstream->avail_out;
    119}
    120
    121int vnc_zlib_send_framebuffer_update(VncState *vs, int x, int y, int w, int h)
    122{
    123    int old_offset, new_offset, bytes_written;
    124
    125    vnc_framebuffer_update(vs, x, y, w, h, VNC_ENCODING_ZLIB);
    126
    127    // remember where we put in the follow-up size
    128    old_offset = vs->output.offset;
    129    vnc_write_s32(vs, 0);
    130
    131    // compress the stream
    132    vnc_zlib_start(vs);
    133    vnc_raw_send_framebuffer_update(vs, x, y, w, h);
    134    bytes_written = vnc_zlib_stop(vs);
    135
    136    if (bytes_written == -1)
    137        return 0;
    138
    139    // hack in the size
    140    new_offset = vs->output.offset;
    141    vs->output.offset = old_offset;
    142    vnc_write_u32(vs, bytes_written);
    143    vs->output.offset = new_offset;
    144
    145    return 1;
    146}
    147
    148void vnc_zlib_clear(VncState *vs)
    149{
    150    if (vs->zlib.stream.opaque) {
    151        deflateEnd(&vs->zlib.stream);
    152    }
    153    buffer_free(&vs->zlib.zlib);
    154}