init

CMakeLists.txt

@@ -0,0 +1,33 @@
+cmake_minimum_required(VERSION 3.13)
+project(kmsvnc LANGUAGES C)
+
+IF(NOT CMAKE_BUILD_TYPE OR CMAKE_BUILD_TYPE STREQUAL "")
+  set(CMAKE_BUILD_TYPE "Release" CACHE STRING "" FORCE)
+endif()
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+find_package(PkgConfig REQUIRED)
+pkg_search_module(LIBDRM REQUIRED libdrm)
+pkg_search_module(LIBVNCSERVER REQUIRED libvncserver)
+pkg_search_module(XKBCOMMON REQUIRED xkbcommon)
+
+include(CheckIncludeFiles)
+CHECK_INCLUDE_FILES("linux/uinput.h;linux/dma-buf.h" HAVE_LINUX_API_HEADERS)
+IF(NOT HAVE_LINUX_API_HEADERS)
+  message(FATAL_ERROR "linux-api-headers not found")
+ENDIF()
+
+add_executable(kmsvnc kmsvnc.c drm.c input.c keymap.c)
+target_include_directories(kmsvnc PUBLIC
+  ${LIBDRM_INCLUDEDIR}
+  ${LIBDRM_INCLUDEDIR}/libdrm
+  ${LIBVNCSERVER_INCLUDEDIR}
+  ${XKBCOMMON_INCLUDEDIR}
+)
+target_link_libraries(kmsvnc PUBLIC
+  m
+  ${LIBDRM_LIBRARIES}
+  ${LIBVNCSERVER_LIBRARIES}
+  ${XKBCOMMON_LIBRARIES}
+)
+install(TARGETS kmsvnc RUNTIME DESTINATION bin)

README.md

@@ -0,0 +1,25 @@
+# kmsvnc
+
+## Introduction
+A VNC server for DRM/KMS capable GNU/Linux devices.  
+The goal is to simply have a universally working vncserver on X, wayland and even something like kmscon.  
+Currently in very early stage.
+
+## Dependencies
+ * cmake
+ * libvncserver
+ * libxkbcommon
+ * libdrm
+
+## Building
+```
+mkdir build
+cd build
+cmake ..
+make
+```
+
+## Running
+Helps are available via `kmsvnc --help`.  
+For example, `kmsvnc -p 5901 -b 0.0.0.0 -4 -d /dev/dri/card2`  
+Note that no security is currently supported.

drm.c

@@ -0,0 +1,356 @@
+#include <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+
+#include "drm.h"
+
+extern struct kmsvnc_data *kmsvnc;
+
+static void convert_copy(const char *in, int width, int height, char *buff) {
+    memcpy(buff, in, width * height * 4);
+}
+
+static void convert_bgrx_to_rgb(const char *in, int width, int height, char *buff)
+{
+    for (int y = 0; y < height; y++)
+    {
+        for (int x = 0; x < width; x++)
+        {
+            buff[(y * width + x) * 4] = in[(y * width + x) * 4 + 2];
+            buff[(y * width + x) * 4 + 1] = in[(y * width + x) * 4 + 1];
+            buff[(y * width + x) * 4 + 2] = in[(y * width + x) * 4];
+        }
+    }
+}
+
+static char *kms_convert_buf = NULL;
+static size_t kms_convert_buf_len = 0;
+static char *kms_cpy_tmp_buf = NULL;
+static size_t kms_cpy_tmp_buf_len = 0;
+static inline void convert_kmsbuf(const int XSTRIPE, const int YSTRIPE, const char *in, int width, int height, char *buff)
+{
+    if (width % XSTRIPE)
+    {
+        return;
+    }
+    if (height % YSTRIPE)
+    {
+        int sno = (width / XSTRIPE) + (height / YSTRIPE) * (width / XSTRIPE);
+        int ord = (width % XSTRIPE) + (height % YSTRIPE) * XSTRIPE;
+        int max_offset = sno * XSTRIPE * YSTRIPE + ord;
+        if (kms_cpy_tmp_buf_len < max_offset * 4 + 4)
+        {
+            if (kms_cpy_tmp_buf)
+                free(kms_convert_buf);
+            kms_cpy_tmp_buf = malloc(max_offset * 4 + 4);
+            kms_cpy_tmp_buf_len = max_offset * 4 + 4;
+        }
+        memcpy(kms_cpy_tmp_buf, in, max_offset * 4 + 4);
+        in = (const char *)kms_cpy_tmp_buf;
+    }
+    if (kms_convert_buf_len < width * height * 4)
+    {
+        if (kms_convert_buf)
+            free(kms_convert_buf);
+        kms_convert_buf = malloc(width * height * 4);
+        kms_convert_buf_len = width * height * 4;
+    }
+    for (int y = 0; y < height; y++)
+    {
+        for (int x = 0; x < width; x++)
+        {
+            int sno = (x / XSTRIPE) + (y / YSTRIPE) * (width / XSTRIPE);
+            int ord = (x % XSTRIPE) + (y % YSTRIPE) * XSTRIPE;
+            int offset = sno * XSTRIPE * YSTRIPE + ord;
+            memcpy(kms_convert_buf + (x + y * width) * 4, in + offset * 4, 4);
+        }
+    }
+    convert_bgrx_to_rgb(kms_convert_buf, width, height, buff);
+}
+
+#define XSTRIPE_INTEL 128
+#define YSTRIPE_INTEL 8
+#define XSTRIPE_NVIDIA 16
+#define YSTRIPE_NVIDIA 128
+
+void convert_nvidia_kmsbuf(const char *in, int width, int height, char *buff)
+{
+    convert_kmsbuf(XSTRIPE_NVIDIA, YSTRIPE_NVIDIA, in, width, height, buff);
+}
+void convert_intel_kmsbuf(const char *in, int width, int height, char *buff)
+{
+    convert_kmsbuf(XSTRIPE_INTEL, YSTRIPE_INTEL, in, width, height, buff);
+}
+
+static inline void drm_sync(int drmfd, uint64_t flags)
+{
+    int ioctl_err;
+    struct dma_buf_sync sync = {
+        .flags = flags,
+    };
+    if (ioctl_err = ioctl(drmfd, DMA_BUF_IOCTL_SYNC, &sync)) {
+        fprintf(stderr, "DRM ioctl error %d on line %d\n", ioctl_err, __LINE__);
+    }
+}
+
+void drm_sync_start(int drmfd)
+{
+    drm_sync(drmfd, DMA_BUF_SYNC_START | DMA_BUF_SYNC_READ);
+}
+void drm_sync_end(int drmfd)
+{
+    drm_sync(drmfd, DMA_BUF_SYNC_END | DMA_BUF_SYNC_READ);
+}
+void drm_sync_noop(int drmfd)
+{
+}
+
+void drm_cleanup() {
+    if (kmsvnc->drm) {
+        if (kmsvnc->drm->drm_ver) {
+            drmFreeVersion(kmsvnc->drm->drm_ver);
+            kmsvnc->drm->drm_ver = NULL;
+        }
+        if (kmsvnc->drm->plane) {
+            drmModeFreePlane(kmsvnc->drm->plane);
+            kmsvnc->drm->plane = NULL;
+        }
+        if (kmsvnc->drm->mfb) {
+            drmModeFreeFB(kmsvnc->drm->mfb);
+            kmsvnc->drm->mfb = NULL;
+        }
+        if (kmsvnc->drm->mapped) {
+            munmap(kmsvnc->drm->mapped, kmsvnc->drm->mmap_size);
+            kmsvnc->drm->mapped = NULL;
+        }
+        if (kmsvnc->drm->prime_fd > 0) {
+            close(kmsvnc->drm->prime_fd);
+            kmsvnc->drm->prime_fd = 0;
+        }
+        if (kmsvnc->drm->drm_fd > 0) {
+            close(kmsvnc->drm->drm_fd);
+            kmsvnc->drm->drm_fd = 0;
+        }
+        free(kmsvnc->drm);
+        kmsvnc->drm = NULL;
+    }
+}
+
+int drm_open() {
+    struct kmsvnc_drm_data *drm = malloc(sizeof(struct kmsvnc_drm_data));
+    memset(drm, 0, sizeof(struct kmsvnc_drm_data));
+    kmsvnc->drm = drm;
+
+    drm->drm_fd = open(kmsvnc->card, O_RDONLY);
+    if (drm->drm_fd < 0)
+    {
+        DRM_FATAL("card %s open failed: %s\n", kmsvnc->card, strerror(errno));
+    }
+    drm->drm_ver = drmGetVersion(drm->drm_fd);
+    int err = drmSetClientCap(drm->drm_fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);
+    if (err < 0)
+    {
+        perror("Failed to set universal planes capability: primary planes will not be usable");
+    }
+    if (drm->source_plane > 0)
+    {
+        drm->plane = drmModeGetPlane(drm->drm_fd, drm->source_plane);
+        if (!drm->plane)
+            DRM_FATAL("Failed to get plane %d: %s\n", drm->source_plane, strerror(errno));
+        if (drm->plane->fb_id == 0)
+            fprintf(stderr, "Place %d does not have an attached framebuffer\n", drm->source_plane);
+    }
+    else
+    {
+        drm->plane_res = drmModeGetPlaneResources(drm->drm_fd);
+        if (!drm->plane_res)
+            DRM_FATAL("Failed to get plane resources: %s\n", strerror(errno));
+        int i;
+        for (i = 0; i < drm->plane_res->count_planes; i++)
+        {
+            drm->plane = drmModeGetPlane(drm->drm_fd, drm->plane_res->planes[i]);
+            if (!drm->plane)
+            {
+                fprintf(stderr, "Failed to get plane %u: %s\n", drm->plane_res->planes[i], strerror(errno));
+                continue;
+            }
+            printf("Plane %u CRTC %u FB %u\n", drm->plane->plane_id, drm->plane->crtc_id, drm->plane->fb_id);
+            if ((drm->source_crtc > 0 && drm->plane->crtc_id != drm->source_crtc) || drm->plane->fb_id == 0)
+            {
+                // Either not connected to the target source CRTC
+                // or not active.
+                drmModeFreePlane(drm->plane);
+                drm->plane = NULL;
+                continue;
+            }
+            break;
+        }
+        if (i == drm->plane_res->count_planes)
+        {
+            if (drm->source_crtc > 0)
+            {
+                DRM_FATAL("No usable planes found on CRTC %d\n", drm->source_crtc);
+            }
+            else
+            {
+                DRM_FATAL("No usable planes found\n");
+            }
+        }
+        printf("Using plane %u to locate framebuffers\n", drm->plane->plane_id);
+    }
+    uint32_t plane_id = drm->plane->plane_id;
+
+    drm->mfb = drmModeGetFB(drm->drm_fd, drm->plane->fb_id);
+    if (!drm->mfb)
+    {
+        DRM_FATAL("Failed to get framebuffer %u: %s\n", drm->plane->fb_id, strerror(errno));
+    }
+    printf("Template framebuffer is %u: %ux%u %ubpp %ub depth %u pitch\n", drm->mfb->fb_id, drm->mfb->width, drm->mfb->height, drm->mfb->bpp, drm->mfb->depth, drm->mfb->pitch);
+
+    if (drm->mfb->bpp != BYTES_PER_PIXEL * 8 || drm->mfb->depth != 24)
+    {
+        DRM_FATAL("Unsupported pixfmt\n");
+    }
+
+    if (!drm->mfb->handle)
+    {
+        DRM_FATAL("No handle set on framebuffer: maybe you need some additional capabilities?\n");
+    }
+
+    int ioctl_err = 0;
+
+    printf("drm driver is %s\n", drm->drm_ver->name);
+
+    drm->mmap_fd = drm->drm_fd;
+    drm->mmap_size = drm->mfb->width * drm->mfb->height * BYTES_PER_PIXEL;
+    drm->funcs = malloc(sizeof(struct kmsvnc_drm_funcs));
+    drm->funcs->convert = convert_bgrx_to_rgb;
+    drm->funcs->sync_start = drm_sync_noop;
+    drm->funcs->sync_end = drm_sync_noop;
+
+    if (drm_vendors()) return 1;
+
+    return 0;
+}
+
+
+static int drm_kmsbuf_prime() {
+    struct kmsvnc_drm_data *drm = kmsvnc->drm;
+
+    int err = drmPrimeHandleToFD(drm->drm_fd, drm->mfb->handle, O_RDWR, &drm->prime_fd);
+    if (err < 0 || drm->prime_fd < 0)
+    {
+        DRM_FATAL("Failed to get PRIME fd from framebuffer handle");
+    }
+    drm->funcs->sync_start = &drm_sync_start;
+    drm->funcs->sync_end = &drm_sync_end;
+    drm->mmap_fd = drm->prime_fd;
+    return 0;
+}
+
+static int drm_kmsbuf_dumb() {
+    struct kmsvnc_drm_data *drm = kmsvnc->drm;
+
+    struct drm_gem_flink flink;
+    flink.handle = drm->mfb->handle;
+    DRM_IOCTL_MUST(drm->drm_fd, DRM_IOCTL_GEM_FLINK, &flink);
+
+    struct drm_gem_open open_arg;
+    open_arg.name = flink.name;
+    DRM_IOCTL_MUST(drm->drm_fd, DRM_IOCTL_GEM_OPEN, &open_arg);
+
+    struct drm_mode_map_dumb mreq;
+    memset(&mreq, 0, sizeof(mreq));
+    mreq.handle = open_arg.handle;
+    DRM_IOCTL_MUST(drm->drm_fd, DRM_IOCTL_MODE_MAP_DUMB, &mreq);
+
+    drm->mmap_size = open_arg.size;
+    drm->mmap_offset = mreq.offset;
+
+    drm->funcs->sync_start = &drm_sync_noop;
+    drm->funcs->sync_end = &drm_sync_noop;
+    return 0;
+}
+
+int drm_vendors() {
+    struct kmsvnc_drm_data *drm = kmsvnc->drm;
+
+    char *driver_name;
+    if (kmsvnc->force_driver) {
+        printf("using %s instead of %s\n", kmsvnc->force_driver, drm->drm_ver->name);
+        driver_name = kmsvnc->force_driver;
+    }
+    else {
+        driver_name = drm->drm_ver->name;
+    }
+
+    if (strcmp(driver_name, "i915") == 0)
+    {
+        drm->funcs->convert = &convert_intel_kmsbuf;
+        if (drm_kmsbuf_prime()) return 1;
+    }
+    else if (strcmp(driver_name, "amdgpu") == 0)
+    {
+        struct drm_gem_flink flink;
+        flink.handle = drm->mfb->handle;
+        DRM_IOCTL_MUST(drm->drm_fd, DRM_IOCTL_GEM_FLINK, &flink);
+
+        struct drm_gem_open open_arg;
+        open_arg.name = flink.name;
+        DRM_IOCTL_MUST(drm->drm_fd, DRM_IOCTL_GEM_OPEN, &open_arg);
+
+        union drm_amdgpu_gem_mmap mmap_arg;
+        memset(&mmap_arg, 0, sizeof(mmap_arg));
+        mmap_arg.in.handle = open_arg.handle;
+        DRM_IOCTL_MUST(drm->drm_fd, DRM_IOCTL_AMDGPU_GEM_MMAP, &mmap_arg);
+
+        drm->mmap_size = open_arg.size;
+        drm->mmap_offset = mmap_arg.out.addr_ptr;
+
+        drm->funcs->sync_start = &drm_sync_noop;
+        drm->funcs->sync_end = &drm_sync_noop;
+    }
+    else if (strcmp(driver_name, "nvidia-drm") == 0)
+    {
+        // quirky and slow
+        drm->funcs->convert = &convert_nvidia_kmsbuf;
+        if (drm_kmsbuf_dumb()) return 1;
+    }
+    else if (strcmp(driver_name, "vmwgfx") == 0 ||
+             strcmp(driver_name, "vboxvideo") == 0 ||
+             strcmp(driver_name, "virtio_gpu") == 0
+    )
+    {
+        // virgl does not work
+        if (drm_kmsbuf_dumb()) return 1;
+    }
+    else if (strcmp(driver_name, "test-prime") == 0)
+    {
+        if (drm_kmsbuf_prime()) return 1;
+    }
+    else if (strcmp(driver_name, "test-map-dumb") == 0)
+    {
+        if (drm_kmsbuf_dumb()) return 1;
+    }
+    else
+    {
+        fprintf(stderr, "Untested drm driver, use at your own risk!\n");
+        if (drm_kmsbuf_dumb()) return 1;
+    }
+
+    if (!drm->mapped)
+    {
+        printf("mapping with size = %d, offset = %d, fd = %d\n", drm->mmap_size, drm->mmap_offset, drm->mmap_fd);
+        drm->mapped = mmap(NULL, drm->mmap_size, PROT_READ, MAP_SHARED, drm->mmap_fd, drm->mmap_offset);
+        if (drm->mapped == MAP_FAILED)
+        {
+            DRM_FATAL("Failed to mmap: %s\n", strerror(errno));
+        }
+    }
+
+    return 0;
+}

drm.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include "kmsvnc.h"
+
+#define DRM_FATAL(...) { fprintf(stderr, __VA_ARGS__); return 1; }
+#define DRM_IOCTL_MUST(...) { int e; if (e = drmIoctl(__VA_ARGS__)) DRM_FATAL("DRM ioctl error %d on line %d\n", e, __LINE__) }
+#define DRM_IOCTL_MAY(...) { int e; if (e = drmIoctl(__VA_ARGS__)) fprintf(stderr, "DRM ioctl error %d on line %d\n", e, __LINE__); }
+
+void drm_cleanup();
+int drm_open();
+int drm_vendors();

input.c

@@ -0,0 +1,185 @@
+#include <stdio.h>
+#include <fcntl.h>
+#include <linux/uinput.h>
+#include <math.h>
+#include <stdlib.h>
+
+#include "input.h"
+#include "keymap.h"
+
+extern struct kmsvnc_data *kmsvnc;
+
+void uinput_cleanup()
+{
+    if (kmsvnc->input) {
+        if (kmsvnc->input->uinput_fd > 0){
+            INP_IOCTL_MAY(kmsvnc->input->uinput_fd, UI_DEV_DESTROY);
+            close(kmsvnc->input->uinput_fd);
+            kmsvnc->input->uinput_fd = 0;
+        }
+        if (kmsvnc->input->keystate){
+            free(kmsvnc->input->keystate);
+            kmsvnc->input->keystate = NULL;
+        }
+        free(kmsvnc->input);
+        kmsvnc->input = NULL;
+    }
+}
+
+int uinput_init()
+{
+    struct kmsvnc_input_data *inp = malloc(sizeof(struct kmsvnc_input_data));
+    memset(inp, 0, sizeof(struct kmsvnc_input_data));
+    kmsvnc->input = inp;
+
+    inp->uinput_fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK);
+    if (inp->uinput_fd <= 0)
+    {
+        INP_FATAL("Failed to open uinput\n");
+    }
+    INP_IOCTL_MUST(inp->uinput_fd, UI_SET_EVBIT, EV_KEY);
+    INP_IOCTL_MUST(inp->uinput_fd, UI_SET_EVBIT, EV_SYN);
+    for (int i = 0; i < UINPUT_MAX_KEY; i++)
+    {
+        INP_IOCTL_MUST(inp->uinput_fd, UI_SET_KEYBIT, i);
+    }
+
+    INP_IOCTL_MUST(inp->uinput_fd, UI_SET_EVBIT, EV_ABS);
+    INP_IOCTL_MUST(inp->uinput_fd, UI_SET_ABSBIT, ABS_X);
+    INP_IOCTL_MUST(inp->uinput_fd, UI_SET_ABSBIT, ABS_Y);
+
+    INP_IOCTL_MUST(inp->uinput_fd, UI_SET_KEYBIT, BTN_LEFT);
+    INP_IOCTL_MUST(inp->uinput_fd, UI_SET_KEYBIT, BTN_MIDDLE);
+    INP_IOCTL_MUST(inp->uinput_fd, UI_SET_KEYBIT, BTN_RIGHT);
+    INP_IOCTL_MUST(inp->uinput_fd, UI_SET_EVBIT, EV_REL);
+    INP_IOCTL_MUST(inp->uinput_fd, UI_SET_RELBIT, REL_WHEEL);
+
+    struct uinput_abs_setup abs;
+    memset(&abs, 0, sizeof(abs));
+    abs.absinfo.maximum = UINPUT_ABS_MAX;
+    abs.absinfo.minimum = 0;
+    abs.code = ABS_X;
+    INP_IOCTL_MUST(inp->uinput_fd, UI_ABS_SETUP, &abs);
+    abs.code = ABS_Y;
+    INP_IOCTL_MUST(inp->uinput_fd, UI_ABS_SETUP, &abs);
+
+    struct uinput_setup usetup;
+    memset(&usetup, 0, sizeof(usetup));
+    usetup.id.bustype = BUS_USB;
+    usetup.id.vendor = 0x0011;
+    usetup.id.product = 0x4514;
+    strcpy(usetup.name, "kmsvnc");
+
+    INP_IOCTL_MUST(inp->uinput_fd, UI_DEV_SETUP, &usetup);
+    INP_IOCTL_MUST(inp->uinput_fd, UI_DEV_CREATE);
+
+    inp->keystate = malloc(UINPUT_MAX_KEY);
+    memset(inp->keystate, 0, UINPUT_MAX_KEY);
+
+    return 0;
+}
+
+void rfb_key_hook(rfbBool down, rfbKeySym keysym, rfbClientPtr cl)
+{
+    struct key_iter_search search = {
+        .keysym = keysym,
+        .keycode = XKB_KEYCODE_INVALID,
+        .level = 0,
+    };
+    xkb_keymap_key_for_each(kmsvnc->keymap->map, key_iter, &search);
+    if (search.keycode == XKB_KEYCODE_INVALID)
+    {
+        fprintf(stderr, "Keysym %04x not found in our keymap\n", keysym);
+        return;
+    }
+    // printf("key %s, keysym %04x, keycode %u\n", down ? "down" : "up", keysym, search.keycode);
+    if (search.keycode >= UINPUT_MAX_KEY)
+    {
+        fprintf(stderr, "Keycode %d >= %d\n", search.keycode, UINPUT_MAX_KEY);
+        return;
+    }
+    if (down != kmsvnc->input->keystate[search.keycode])
+    {
+        struct input_event ies[] = {
+            {
+                .type = EV_KEY,
+                .code = search.keycode - 8, // magic
+                .value = down,
+                .time.tv_sec = 0,
+                .time.tv_usec = 0,
+            },
+            {
+                .type = EV_SYN,
+                .code = SYN_REPORT,
+                .value = 0,
+            },
+        };
+        for (int i = 0; i < ARRAY_SIZE(ies); i++)
+        {
+            write(kmsvnc->input->uinput_fd, &ies[i], sizeof(ies[0]));
+        }
+
+        kmsvnc->input->keystate[search.keycode] = down;
+    }
+}
+
+void rfb_ptr_hook(int mask, int screen_x, int screen_y, rfbClientPtr cl)
+{
+    // printf("pointer to %d, %d\n", screen_x, screen_y);
+    float global_x = (float)screen_x;
+    float global_y = (float)screen_y;
+    int touch_x = round(global_x / kmsvnc->drm->mfb->width * UINPUT_ABS_MAX);
+    int touch_y = round(global_y / kmsvnc->drm->mfb->height * UINPUT_ABS_MAX);
+    struct input_event ies1[] = {
+        {
+            .type = EV_ABS,
+            .code = ABS_X,
+            .value = touch_x,
+        },
+        {
+            .type = EV_ABS,
+            .code = ABS_Y,
+            .value = touch_y,
+        },
+        {
+            .type = EV_KEY,
+            .code = BTN_LEFT,
+            .value = !!(mask & 0b1)},
+        {
+            .type = EV_KEY,
+            .code = BTN_MIDDLE,
+            .value = !!(mask & 0b10)},
+        {
+            .type = EV_KEY,
+            .code = BTN_RIGHT,
+            .value = !!(mask & 0b100)},
+        {
+            .type = EV_SYN,
+            .code = SYN_REPORT,
+            .value = 0,
+        },
+    };
+    for (int i = 0; i < ARRAY_SIZE(ies1); i++)
+    {
+        write(kmsvnc->input->uinput_fd, &ies1[i], sizeof(ies1[0]));
+    }
+    if (mask & 0b11000)
+    {
+        struct input_event ies2[] = {
+            {
+                .type = EV_REL,
+                .code = REL_WHEEL,
+                .value = mask & 0b1000 ? 1 : -1,
+            },
+            {
+                .type = EV_SYN,
+                .code = SYN_REPORT,
+                .value = 0,
+            },
+        };
+        for (int i = 0; i < ARRAY_SIZE(ies2); i++)
+        {
+            write(kmsvnc->input->uinput_fd, &ies2[i], sizeof(ies2[0]));
+        }
+    }
+}

input.h

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <rfb/rfb.h>
+
+#include "kmsvnc.h"
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
+
+#define UINPUT_ABS_MAX INT16_MAX
+#define UINPUT_MAX_KEY 256
+
+#define INP_FATAL(...) { fprintf(stderr, __VA_ARGS__); return 1; }
+#define INP_IOCTL_MUST(...) { int e; if (e = ioctl(__VA_ARGS__)) INP_FATAL("uinput ioctl error %d on line %d\n", e, __LINE__) }
+#define INP_IOCTL_MAY(...) { int e; if (e = ioctl(__VA_ARGS__)) fprintf(stderr, "uinput ioctl error %d on line %d\n", e, __LINE__); }
+
+void uinput_cleanup();
+int uinput_init();
+void rfb_key_hook(rfbBool down, rfbKeySym keysym, rfbClientPtr cl);
+void rfb_ptr_hook(int mask, int screen_x, int screen_y, rfbClientPtr cl);

keymap.c

@@ -0,0 +1,77 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "keymap.h"
+
+extern struct kmsvnc_data *kmsvnc;
+
+void xkb_cleanup() {
+    if (kmsvnc->keymap) {
+        if (kmsvnc->keymap->map) {
+            xkb_keymap_unref(kmsvnc->keymap->map);
+            kmsvnc->keymap->map = NULL;
+        }
+        if (kmsvnc->keymap->ctx) {
+            xkb_context_unref(kmsvnc->keymap->ctx);
+            kmsvnc->keymap->ctx = NULL;
+        }
+        free(kmsvnc->keymap);
+        kmsvnc->keymap = NULL;
+    }
+}
+
+int xkb_init()
+{
+    struct kmsvnc_keymap_data *xkb = malloc(sizeof(struct kmsvnc_keymap_data));
+    memset(xkb, 0, sizeof(struct kmsvnc_keymap_data));
+    kmsvnc->keymap = xkb;
+
+    xkb->ctx = xkb_context_new(XKB_CONTEXT_NO_FLAGS);
+    if (xkb->ctx == NULL)
+    {
+        XKB_FATAL("Failed to create XKB context\n");
+    }
+    struct xkb_rule_names names = {
+        .rules = NULL,
+        .model = NULL,
+        .layout = NULL,
+        .variant = NULL,
+        .options = NULL,
+    };
+    xkb->map = xkb_keymap_new_from_names(xkb->ctx, &names, 0);
+    if (xkb->map == NULL)
+    {
+        XKB_FATAL("Failed to create XKB keymap\n");
+    }
+    // printf("xkb: keymap string\n%s\n", xkb_keymap_get_as_string(xkb->map, XKB_KEYMAP_USE_ORIGINAL_FORMAT));
+    return 0;
+}
+
+
+void key_iter(struct xkb_keymap *xkb, xkb_keycode_t key, void *data)
+{
+    struct key_iter_search *search = data;
+    if (search->keycode != XKB_KEYCODE_INVALID)
+    {
+        return; // We are done
+    }
+    xkb_level_index_t num_levels = xkb_keymap_num_levels_for_key(xkb, key, 0);
+    for (xkb_level_index_t i = 0; i < num_levels; i++)
+    {
+        const xkb_keysym_t *syms;
+        int num_syms = xkb_keymap_key_get_syms_by_level(xkb, key, 0, i, &syms);
+        for (int k = 0; k < num_syms; k++)
+        {
+            if (syms[k] == search->keysym)
+            {
+                search->keycode = key;
+                search->level = i;
+                goto end;
+            }
+        }
+    }
+end:
+    return;
+}

keymap.h

@@ -0,0 +1,9 @@
+#pragma once
+
+#include "kmsvnc.h"
+
+#define XKB_FATAL(...) { fprintf(stderr, __VA_ARGS__); return 1; }
+
+void xkb_cleanup();
+int xkb_init();
+void key_iter(struct xkb_keymap *xkb, xkb_keycode_t key, void *data);

kmsvnc.c

@@ -0,0 +1,281 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <time.h>
+#include <argp.h>
+#include <arpa/inet.h>
+
+#include "kmsvnc.h"
+#include "keymap.h"
+#include "input.h"
+#include "drm.h"
+
+struct kmsvnc_data *kmsvnc = NULL;
+
+#define NS_IN_S 1000000000
+
+static void between_frames()
+{
+    static struct timespec now = {0, 0}, then = {0, 0}, tmp = {0, 0};
+
+    clock_gettime(CLOCK_MONOTONIC, &now);
+    memcpy((char *)&then, (char *)&tmp, sizeof(struct timespec));
+    tmp.tv_nsec += kmsvnc->vnc_opt->sleep_ns;
+    if (tmp.tv_nsec >= NS_IN_S)
+    {
+        tmp.tv_sec++;
+        tmp.tv_nsec %= NS_IN_S;
+    }
+    if (now.tv_sec < tmp.tv_sec || (now.tv_sec == tmp.tv_sec && now.tv_nsec < tmp.tv_nsec))
+    {
+        then.tv_sec = tmp.tv_sec - now.tv_sec;
+        then.tv_nsec = tmp.tv_nsec - now.tv_nsec;
+        if (then.tv_nsec < 0)
+        {
+            then.tv_sec--;
+            then.tv_nsec += NS_IN_S;
+        }
+        nanosleep(&then, &then);
+    }
+    memcpy((char *)&now, (char *)&then, sizeof(struct timespec));
+}
+
+static void update_screen_buf(char* to, char *from, int width, int height) {
+    uint64_t *double_pix_from = (uint64_t *)from;
+    uint64_t *double_pix_to = (uint64_t *)to;
+    int min_x = INT32_MAX;
+    int min_y = INT32_MAX;
+    int max_x = -1;
+    int max_y = -1;
+    if (width % 2 == 0) {
+        for (int y = 0; y < height; y++) {
+            for (int x = 0; x < width; x+=2) {
+                if (*double_pix_from != *double_pix_to) {
+                    if (x < min_x) {
+                        min_x = x;
+                    }
+                    if (x > max_x) {
+                        max_x = x;
+                    }
+                    if (y < min_y) {
+                        min_y = y;
+                    }
+                    if (y > max_y) {
+                        max_y = y;
+                    }
+                }
+                double_pix_from ++;
+                double_pix_to ++;
+            }
+        }
+    }
+    max_x = max_x < 0 ? 0 : max_x;
+    max_y = max_y < 0 ? 0 : max_y;
+    min_x = min_x > width ? 0 : min_x;
+    min_y = min_y > height ? 0 : min_y;
+
+    //printf("dirty: %d, %d, %d, %d\n", min_x, min_y, max_x, max_y);
+    if (max_x || max_y || min_x || min_y) {
+        memcpy(to, from, width * height * BYTES_PER_PIXEL);
+        rfbMarkRectAsModified(kmsvnc->server, min_x, min_y, max_x, max_y);
+    }
+}
+
+static void cleanup() {
+    if (kmsvnc->keymap) {
+        xkb_cleanup();
+    }
+    if (kmsvnc->input) {
+        uinput_cleanup();
+    }
+    if (kmsvnc->drm) {
+        drm_cleanup();
+    }
+    if (kmsvnc) {
+        if (kmsvnc->vnc_opt) {
+            free(kmsvnc->vnc_opt);
+            kmsvnc->vnc_opt = NULL;
+        }
+        if (kmsvnc->buf1) {
+            free(kmsvnc->buf1);
+            kmsvnc->buf1 = NULL;
+        }
+        if (kmsvnc->buf) {
+            free(kmsvnc->buf);
+            kmsvnc->buf = NULL;
+        }
+        free(kmsvnc);
+        kmsvnc = NULL;
+    }
+}
+
+void signal_handler(int signum){
+    if (kmsvnc->shutdown) {
+        return;
+    }
+    kmsvnc->shutdown = 1;
+    if (kmsvnc->server) {
+        rfbShutdownServer(kmsvnc->server,TRUE);
+    }
+}
+
+static struct argp_option kmsvnc_main_options[] = {
+    {"device", 'd', "/dev/dri/card0", 0, "DRM device"},
+    {"force-driver", 0xfefe, "i915", 0, "force a certain driver (for debug)"},
+    {"bind", 'b', "0.0.0.0", 0, "Listen on (ipv4 address)"},
+    {"bind6", 0xfeff, "::", 0, "Listen on (ipv6 address)"},
+    {"port", 'p', "5900", 0, "Listen port"},
+    {"disable-ipv6", '4', 0, OPTION_ARG_OPTIONAL, "Disable ipv6"},
+    {"fps", 0xff00, "30", 0, "Target frames per second"},
+    {"disable-always-shared", 0xff01, 0, OPTION_ARG_OPTIONAL, "Do not always treat incoming connections as shared"},
+    {"disable-input", 'i', 0, OPTION_ARG_OPTIONAL, "Disable uinput"},
+    {"desktop-name", 'n', "kmsvnc", 0, "Specify vnc desktop name"},
+    {0}
+};
+
+static error_t parse_opt(int key, char *arg, struct argp_state *state) {
+    int *arg_cout = state->input;
+
+    switch (key) {
+        case 'd':
+            argp_usage(state);
+            kmsvnc->card = arg;
+            break;
+        case 0xfefe:
+            kmsvnc->force_driver = arg;
+            break;
+        case 'b':
+            if (!inet_aton(arg, kmsvnc->vnc_opt->bind)) {
+                argp_error(state, "invalid ipv4 address %s", arg);
+            }
+            break;
+        case 0xfeff:
+            kmsvnc->vnc_opt->bind6 = arg;
+            break;
+        case 'p':
+            int port = atoi(arg);
+            if (port > 0 && port < 65536) {
+                kmsvnc->vnc_opt->port = port;
+            }
+            else {
+                argp_error(state, "invalid port %s", arg);
+            }
+            break;
+        case '4':
+            kmsvnc->vnc_opt->disable_ipv6 = 1;
+            break;
+        case 0xff00:
+            int fps = atoi(arg);
+            if (fps > 0 && fps < 1000) {
+                kmsvnc->vnc_opt->sleep_ns = NS_IN_S / fps;
+            }
+            else {
+                argp_error(state, "invalid fps %s", arg);
+            }
+            break;
+        case 0xff01:
+            kmsvnc->vnc_opt->always_shared = 0;
+            break;
+        case 'i':
+            kmsvnc->disable_input = 1;
+            break;
+        case 'n':
+            kmsvnc->vnc_opt->desktop_name = arg;
+            break;
+        case ARGP_KEY_ARG:
+            return ARGP_ERR_UNKNOWN;
+        default:
+            return ARGP_ERR_UNKNOWN;
+    }
+    return 0;
+}
+
+int main(int argc, char **argv)
+{
+    struct vnc_opt *vncopt = malloc(sizeof(struct vnc_opt));
+    memset(vncopt, 0, sizeof(struct vnc_opt));
+
+    kmsvnc = malloc(sizeof(struct kmsvnc_data));
+    memset(kmsvnc, 0, sizeof(struct kmsvnc_data));
+
+    kmsvnc->vnc_opt = vncopt;
+
+    kmsvnc->card = "/dev/dri/card0";
+    kmsvnc->vnc_opt->bind = &(struct in_addr){0};
+    kmsvnc->vnc_opt->always_shared = 1;
+    kmsvnc->vnc_opt->port = 5900;
+    kmsvnc->vnc_opt->sleep_ns = NS_IN_S / 30;
+    kmsvnc->vnc_opt->desktop_name = "kmsvnc";
+
+    static char *args_doc = "";
+    static char *doc = "kmsvnc -- vncserver for DRM/KMS capable GNU/Linux devices";
+
+    struct argp argp = {kmsvnc_main_options, parse_opt, args_doc, doc};
+    argp_parse(&argp, argc, argv, 0, 0, NULL);
+
+    const char* XKB_DEFAULT_LAYOUT = getenv("XKB_DEFAULT_LAYOUT");
+    if (!XKB_DEFAULT_LAYOUT || strcmp(XKB_DEFAULT_LAYOUT, "") == 0) {
+        printf("No keyboard layout set from environment variables, use US layout by default\n");
+        printf("See https://xkbcommon.org/doc/current/structxkb__rule__names.html\n");
+        setenv("XKB_DEFAULT_LAYOUT", "us", 1);
+    }
+
+    if (!kmsvnc->disable_input) {
+        if (xkb_init()) {
+            cleanup();
+            return 1;
+        }
+        if (uinput_init()) {
+            cleanup();
+            return 1;
+        }
+    }
+    if (drm_open()) {
+        cleanup();
+        return 1;
+    }
+
+    size_t buflen = kmsvnc->drm->mfb->width * kmsvnc->drm->mfb->height * BYTES_PER_PIXEL;
+    kmsvnc->buf = malloc(buflen);
+    memset(kmsvnc->buf, 0, buflen);
+    kmsvnc->buf1 = malloc(buflen);
+    memset(kmsvnc->buf1, 0, buflen);
+
+    signal(SIGHUP, &signal_handler);
+    signal(SIGINT, &signal_handler);
+    signal(SIGTERM, &signal_handler);
+
+    kmsvnc->server = rfbGetScreen(0, NULL, kmsvnc->drm->mfb->width, kmsvnc->drm->mfb->height, 8, 3, 4);
+    if (!kmsvnc->server) {
+        cleanup();
+        return 1;
+    }
+    kmsvnc->server->desktopName = kmsvnc->vnc_opt->desktop_name;
+    kmsvnc->server->frameBuffer = kmsvnc->buf;
+    kmsvnc->server->port = kmsvnc->vnc_opt->port;
+    kmsvnc->server->listenInterface = kmsvnc->vnc_opt->bind->s_addr;
+    kmsvnc->server->ipv6port = kmsvnc->vnc_opt->disable_ipv6 ? 0 : kmsvnc->vnc_opt->port;
+    kmsvnc->server->listen6Interface = kmsvnc->vnc_opt->bind6;
+    kmsvnc->server->alwaysShared = kmsvnc->vnc_opt->always_shared;
+    if (!kmsvnc->disable_input) {
+        kmsvnc->server->kbdAddEvent = rfb_key_hook;
+        kmsvnc->server->ptrAddEvent = rfb_ptr_hook;
+    }
+    rfbInitServer(kmsvnc->server);
+    rfbRunEventLoop(kmsvnc->server, -1, TRUE);
+    while (rfbIsActive(kmsvnc->server))
+    {
+        between_frames();
+        if (kmsvnc->server->clientHead)
+        {
+            kmsvnc->drm->funcs->sync_start(kmsvnc->drm->prime_fd);
+            kmsvnc->drm->funcs->convert(kmsvnc->drm->mapped, kmsvnc->drm->mfb->width, kmsvnc->drm->mfb->height, kmsvnc->buf1);
+            kmsvnc->drm->funcs->sync_end(kmsvnc->drm->prime_fd);
+            update_screen_buf(kmsvnc->buf, kmsvnc->buf1, kmsvnc->drm->mfb->width, kmsvnc->drm->mfb->height);
+        }
+    }
+    cleanup();
+    return 0;
+}

kmsvnc.h

@@ -0,0 +1,88 @@
+#pragma once
+
+#include <rfb/rfb.h>
+#include <xkbcommon/xkbcommon.h>
+
+#include <xf86drm.h>
+#include <i915_drm.h>
+#include <amdgpu_drm.h>
+#include <xf86drmMode.h>
+#include <linux/dma-buf.h>
+
+
+#define BYTES_PER_PIXEL 4
+
+struct vnc_opt
+{
+    int port;
+    struct in_addr *bind;
+    char *bind6;
+    char disable_ipv6;
+    int sleep_ns;
+    int always_shared;
+    char *desktop_name;
+};
+
+struct kmsvnc_data
+{
+    char *card;
+    char *force_driver;
+    struct vnc_opt *vnc_opt;
+    char disable_input;
+    struct kmsvnc_drm_data *drm;
+    struct kmsvnc_input_data *input;
+    struct kmsvnc_keymap_data *keymap;
+    rfbScreenInfoPtr server;
+    char shutdown;
+    char *buf;
+    char *buf1;
+};
+
+
+
+struct key_iter_search
+{
+    xkb_keysym_t keysym;
+
+    xkb_keycode_t keycode;
+    xkb_level_index_t level;
+};
+
+struct kmsvnc_keymap_data
+{
+    struct xkb_context *ctx;
+    struct xkb_keymap *map;
+};
+
+
+struct kmsvnc_input_data {
+    int uinput_fd;
+    char *keystate;
+};
+
+
+struct kmsvnc_drm_funcs
+{
+    void (*sync_start)(int);
+    void (*sync_end)(int);
+    void (*convert)(const char *, int, int, char *);
+};
+
+struct kmsvnc_drm_data
+{
+    int drm_fd;
+    drmVersionPtr drm_ver;
+    int prime_fd;
+    int source_plane;
+    int source_crtc;
+    drmModePlane *plane;
+    drmModePlaneRes *plane_res;
+    drmModeFB *mfb;
+    u_int32_t plane_id;
+    int mmap_fd;
+    size_t mmap_size;
+    off_t mmap_offset;
+    char *mapped;
+    struct kmsvnc_drm_funcs *funcs;
+};
+