guacamole-client/guacamole/proxy/proxy.c

#include <stdlib.h>
#include <stdio.h>
#include <png.h>

#include "guacio.h"
#include "proxy.h"

void guac_write_png(png_structp png, png_bytep data, png_size_t length) {

    if (guac_write_base64((GUACIO*) png->io_ptr, data, length) < 0) {
        perror("Error writing PNG");
        png_error(png, "Error writing PNG");
        return;
    }

}

void guac_write_flush(png_structp png) {
}

void proxy(int client_fd) {

    png_structp png;
    png_infop png_info;
    png_byte** png_rows;
    png_byte* row;

    int x, y;

    int test_index;

    GUACIO* io = guac_open(client_fd);

    /*** INIT ***/

    /* Allocate rows for PNG */
    png_rows = (png_byte**) malloc(100 /* height */ * sizeof(png_byte*));

    guac_write_string(io, "name:hello;size:1024,768;");

    for (test_index=0; test_index<200; test_index++) {

        /* For now, generate test white image */
        for (y=0; y<100 /* height */; y++) {

            row = (png_byte*) malloc(sizeof(png_byte) * 3 * 100 /* width */);
            png_rows[y] = row;

            for (x=0; x<100 /* width */; x++) {
                *row++ = random() % 0xFF;

                if (test_index % 2 == 0)
                    *row++ = random() % 0xFF;
                else
                    *row++ = 0x00;

                if (test_index % 3 == 0)
                    *row++ = random() % 0xFF;
                else
                    *row++ = 0x00;

            }
        }

        /* Write image */

        /* Set up PNG writer */
        png = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
        if (!png) {
            perror("Error initializing libpng write structure");
            return;
        }

        png_info = png_create_info_struct(png);
        if (!png_info) {
            perror("Error initializing libpng info structure");
            png_destroy_write_struct(&png, NULL);
            return;
        }

        /* Set error handler */
        if (setjmp(png_jmpbuf(png))) {
            perror("Error setting handler");
            png_destroy_write_struct(&png, &png_info);
            return;
        }

        png_set_write_fn(png, io, guac_write_png, guac_write_flush);

        /* Set PNG IHDR */
        png_set_IHDR(
                png,
                png_info,
                100, /* width */
                100, /* height */
                8,
                PNG_COLOR_TYPE_RGB,
                PNG_INTERLACE_NONE,
                PNG_COMPRESSION_TYPE_DEFAULT,
                PNG_FILTER_TYPE_DEFAULT
        );
        
        guac_write_string(io, "png:");
        guac_write_int(io, random()%1024);
        guac_write_string(io, ",");
        guac_write_int(io, random()%768);
        guac_write_string(io, ",");
        png_set_rows(png, png_info, png_rows);
        png_write_png(png, png_info, PNG_TRANSFORM_IDENTITY, NULL);
    
        if (guac_flush_base64(io) < 0) {
            perror("Error flushing PNG");
            png_error(png, "Error flushing PNG");
            return;
        }

        png_destroy_write_struct(&png, &png_info);

        guac_write_string(io, ";");
    }

    guac_write_string(io, "error:Test finished.;");

    /* Free PNG data */
    for (y = 0; y<100 /* height */; y++)
        free(png_rows[y]);
    free(png_rows);

    guac_close(io);
}