Files
gpu-screen-recorder/kms/server/kms_server.c
2025-12-28 13:55:10 -08:00

627 lines
23 KiB
C

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include "../kms_shared.h"
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <locale.h>
#include <unistd.h>
#include <limits.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <time.h>
#include <xf86drm.h>
#include <xf86drmMode.h>
#include <drm_mode.h>
#include <drm_fourcc.h>
#define MAX_CONNECTORS 32
typedef struct {
int drmfd;
} gsr_drm;
typedef struct {
uint32_t connector_id;
uint64_t crtc_id;
uint64_t hdr_metadata_blob_id;
} connector_crtc_pair;
typedef struct {
connector_crtc_pair maps[MAX_CONNECTORS];
int num_maps;
} connector_to_crtc_map;
static int max_int(int a, int b) {
return a > b ? a : b;
}
static int count_num_fds(const gsr_kms_response *response) {
int num_fds = 0;
for(int i = 0; i < response->num_items; ++i) {
num_fds += response->items[i].num_dma_bufs;
}
return num_fds;
}
static int send_msg_to_client(int client_fd, gsr_kms_response *response) {
struct iovec iov;
iov.iov_base = response;
iov.iov_len = sizeof(*response);
struct msghdr response_message = {0};
response_message.msg_iov = &iov;
response_message.msg_iovlen = 1;
const int num_fds = count_num_fds(response);
char cmsgbuf[CMSG_SPACE(sizeof(int) * max_int(1, num_fds))];
memset(cmsgbuf, 0, sizeof(cmsgbuf));
if(num_fds > 0) {
response_message.msg_control = cmsgbuf;
response_message.msg_controllen = sizeof(cmsgbuf);
struct cmsghdr *cmsg = CMSG_FIRSTHDR(&response_message);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(int) * num_fds);
int *fds = (int*)CMSG_DATA(cmsg);
int fd_index = 0;
for(int i = 0; i < response->num_items; ++i) {
for(int j = 0; j < response->items[i].num_dma_bufs; ++j) {
fds[fd_index++] = response->items[i].dma_buf[j].fd;
}
}
response_message.msg_controllen = cmsg->cmsg_len;
}
return sendmsg(client_fd, &response_message, 0);
}
static int recv_msg_from_client(int client_fd, gsr_kms_request *request) {
struct iovec iov;
iov.iov_base = request;
iov.iov_len = sizeof(*request);
struct msghdr response_message = {0};
response_message.msg_iov = &iov;
response_message.msg_iovlen = 1;
char cmsgbuf[CMSG_SPACE(sizeof(int) * 1)];
memset(cmsgbuf, 0, sizeof(cmsgbuf));
response_message.msg_control = cmsgbuf;
response_message.msg_controllen = sizeof(cmsgbuf);
int res = recvmsg(client_fd, &response_message, MSG_WAITALL);
if(res <= 0)
return res;
if(request->new_connection_fd > 0) {
struct cmsghdr *cmsg = CMSG_FIRSTHDR(&response_message);
if(cmsg) {
int *fds = (int*)CMSG_DATA(cmsg);
request->new_connection_fd = fds[0];
} else {
if(request->new_connection_fd > 0) {
close(request->new_connection_fd);
request->new_connection_fd = 0;
}
}
}
return res;
}
static bool connector_get_property_by_name(int drmfd, drmModeConnectorPtr props, const char *name, uint64_t *result) {
for(int i = 0; i < props->count_props; ++i) {
drmModePropertyPtr prop = drmModeGetProperty(drmfd, props->props[i]);
if(prop) {
if(strcmp(name, prop->name) == 0) {
*result = props->prop_values[i];
drmModeFreeProperty(prop);
return true;
}
drmModeFreeProperty(prop);
}
}
return false;
}
typedef enum {
PLANE_PROPERTY_X = 1 << 0,
PLANE_PROPERTY_Y = 1 << 1,
PLANE_PROPERTY_SRC_X = 1 << 2,
PLANE_PROPERTY_SRC_Y = 1 << 3,
PLANE_PROPERTY_SRC_W = 1 << 4,
PLANE_PROPERTY_SRC_H = 1 << 5,
PLANE_PROPERTY_IS_CURSOR = 1 << 6,
PLANE_PROPERTY_IS_PRIMARY = 1 << 7,
PLANE_PROPERTY_ROTATION = 1 << 8,
} plane_property_mask;
/* Returns plane_property_mask */
static uint32_t plane_get_properties(int drmfd, uint32_t plane_id, int *x, int *y, int *src_x, int *src_y, int *src_w, int *src_h, gsr_kms_rotation *rotation) {
*x = 0;
*y = 0;
*src_x = 0;
*src_y = 0;
*src_w = 0;
*src_h = 0;
*rotation = KMS_ROT_0;
plane_property_mask property_mask = 0;
drmModeObjectPropertiesPtr props = drmModeObjectGetProperties(drmfd, plane_id, DRM_MODE_OBJECT_PLANE);
if(!props)
return property_mask;
// TODO: Dont do this every frame
for(uint32_t i = 0; i < props->count_props; ++i) {
drmModePropertyPtr prop = drmModeGetProperty(drmfd, props->props[i]);
if(!prop)
continue;
// SRC_* values are fixed 16.16 points
const uint32_t type = prop->flags & (DRM_MODE_PROP_LEGACY_TYPE | DRM_MODE_PROP_EXTENDED_TYPE);
if((type & DRM_MODE_PROP_SIGNED_RANGE) && strcmp(prop->name, "CRTC_X") == 0) {
*x = (int)props->prop_values[i];
property_mask |= PLANE_PROPERTY_X;
} else if((type & DRM_MODE_PROP_SIGNED_RANGE) && strcmp(prop->name, "CRTC_Y") == 0) {
*y = (int)props->prop_values[i];
property_mask |= PLANE_PROPERTY_Y;
} else if((type & DRM_MODE_PROP_RANGE) && strcmp(prop->name, "SRC_X") == 0) {
*src_x = (int)(props->prop_values[i] >> 16);
property_mask |= PLANE_PROPERTY_SRC_X;
} else if((type & DRM_MODE_PROP_RANGE) && strcmp(prop->name, "SRC_Y") == 0) {
*src_y = (int)(props->prop_values[i] >> 16);
property_mask |= PLANE_PROPERTY_SRC_Y;
} else if((type & DRM_MODE_PROP_RANGE) && strcmp(prop->name, "SRC_W") == 0) {
*src_w = (int)(props->prop_values[i] >> 16);
property_mask |= PLANE_PROPERTY_SRC_W;
} else if((type & DRM_MODE_PROP_RANGE) && strcmp(prop->name, "SRC_H") == 0) {
*src_h = (int)(props->prop_values[i] >> 16);
property_mask |= PLANE_PROPERTY_SRC_H;
} else if((type & DRM_MODE_PROP_ENUM) && strcmp(prop->name, "type") == 0) {
const uint64_t current_enum_value = props->prop_values[i];
for(int j = 0; j < prop->count_enums; ++j) {
if(prop->enums[j].value == current_enum_value && strcmp(prop->enums[j].name, "Primary") == 0) {
property_mask |= PLANE_PROPERTY_IS_PRIMARY;
break;
} else if(prop->enums[j].value == current_enum_value && strcmp(prop->enums[j].name, "Cursor") == 0) {
property_mask |= PLANE_PROPERTY_IS_CURSOR;
break;
}
}
} else if((type & DRM_MODE_PROP_BITMASK) && strcmp(prop->name, "rotation") == 0) {
const uint64_t rotation_bitmask = props->prop_values[i];
*rotation = KMS_ROT_0;
if(rotation_bitmask & 2)
*rotation = (*rotation + KMS_ROT_90) % 4;
if(rotation_bitmask & 4)
*rotation = (*rotation + KMS_ROT_180) % 4;
if(rotation_bitmask & 8)
*rotation = (*rotation + KMS_ROT_270) % 4;
}
drmModeFreeProperty(prop);
}
drmModeFreeObjectProperties(props);
return property_mask;
}
/* Returns NULL if not found */
static const connector_crtc_pair* get_connector_pair_by_crtc_id(const connector_to_crtc_map *c2crtc_map, uint32_t crtc_id) {
for(int i = 0; i < c2crtc_map->num_maps; ++i) {
if(c2crtc_map->maps[i].crtc_id == crtc_id)
return &c2crtc_map->maps[i];
}
return NULL;
}
static void map_crtc_to_connector_ids(gsr_drm *drm, connector_to_crtc_map *c2crtc_map) {
c2crtc_map->num_maps = 0;
drmModeResPtr resources = drmModeGetResources(drm->drmfd);
if(!resources)
return;
for(int i = 0; i < resources->count_connectors && c2crtc_map->num_maps < MAX_CONNECTORS; ++i) {
drmModeConnectorPtr connector = drmModeGetConnectorCurrent(drm->drmfd, resources->connectors[i]);
if(!connector)
continue;
uint64_t crtc_id = 0;
connector_get_property_by_name(drm->drmfd, connector, "CRTC_ID", &crtc_id);
uint64_t hdr_output_metadata_blob_id = 0;
connector_get_property_by_name(drm->drmfd, connector, "HDR_OUTPUT_METADATA", &hdr_output_metadata_blob_id);
c2crtc_map->maps[c2crtc_map->num_maps].connector_id = connector->connector_id;
c2crtc_map->maps[c2crtc_map->num_maps].crtc_id = crtc_id;
c2crtc_map->maps[c2crtc_map->num_maps].hdr_metadata_blob_id = hdr_output_metadata_blob_id;
++c2crtc_map->num_maps;
drmModeFreeConnector(connector);
}
drmModeFreeResources(resources);
}
static void drm_mode_cleanup_handles(int drmfd, drmModeFB2Ptr drmfb) {
for(int i = 0; i < 4; ++i) {
if(!drmfb->handles[i])
continue;
bool already_closed = false;
for(int j = 0; j < i; ++j) {
if(drmfb->handles[i] == drmfb->handles[j]) {
already_closed = true;
break;
}
}
if(already_closed)
continue;
drmCloseBufferHandle(drmfd, drmfb->handles[i]);
}
}
static bool get_hdr_metadata(int drm_fd, uint64_t hdr_metadata_blob_id, struct hdr_output_metadata *hdr_metadata) {
drmModePropertyBlobPtr hdr_metadata_blob = drmModeGetPropertyBlob(drm_fd, hdr_metadata_blob_id);
if(!hdr_metadata_blob)
return false;
if(hdr_metadata_blob->length >= sizeof(struct hdr_output_metadata))
*hdr_metadata = *(struct hdr_output_metadata*)hdr_metadata_blob->data;
drmModeFreePropertyBlob(hdr_metadata_blob);
return true;
}
/* Returns the number of drm handles that we managed to get */
static int drm_prime_handles_to_fds(gsr_drm *drm, drmModeFB2Ptr drmfb, int *fb_fds) {
for(int i = 0; i < GSR_KMS_MAX_DMA_BUFS; ++i) {
if(!drmfb->handles[i])
return i;
const int ret = drmPrimeHandleToFD(drm->drmfd, drmfb->handles[i], O_RDONLY, &fb_fds[i]);
if(ret != 0 || fb_fds[i] == -1)
return i;
}
return GSR_KMS_MAX_DMA_BUFS;
}
static int kms_get_fb(gsr_drm *drm, gsr_kms_response *response) {
int result = -1;
response->result = KMS_RESULT_OK;
response->err_msg[0] = '\0';
response->num_items = 0;
connector_to_crtc_map c2crtc_map;
c2crtc_map.num_maps = 0;
map_crtc_to_connector_ids(drm, &c2crtc_map);
drmModePlaneResPtr planes = drmModeGetPlaneResources(drm->drmfd);
if(!planes) {
fprintf(stderr, "kms server error: failed to get plane resources, error: %s\n", strerror(errno));
goto done;
}
for(uint32_t i = 0; i < planes->count_planes && response->num_items < GSR_KMS_MAX_ITEMS; ++i) {
drmModePlanePtr plane = NULL;
drmModeFB2Ptr drmfb = NULL;
plane = drmModeGetPlane(drm->drmfd, planes->planes[i]);
if(!plane) {
response->result = KMS_RESULT_FAILED_TO_GET_PLANE;
snprintf(response->err_msg, sizeof(response->err_msg), "failed to get drm plane with id %u, error: %s\n", planes->planes[i], strerror(errno));
fprintf(stderr, "kms server error: %s\n", response->err_msg);
goto next;
}
if(!plane->fb_id)
goto next;
drmfb = drmModeGetFB2(drm->drmfd, plane->fb_id);
if(!drmfb) {
// Commented out for now because we get here if the cursor is moved to another monitor and we dont care about the cursor
//response->result = KMS_RESULT_FAILED_TO_GET_PLANE;
//snprintf(response->err_msg, sizeof(response->err_msg), "drmModeGetFB2 failed, error: %s", strerror(errno));
//fprintf(stderr, "kms server error: %s\n", response->err_msg);
goto next;
}
if(!drmfb->handles[0]) {
response->result = KMS_RESULT_FAILED_TO_GET_PLANE;
snprintf(response->err_msg, sizeof(response->err_msg), "drmfb handle is NULL");
fprintf(stderr, "kms server error: %s\n", response->err_msg);
goto cleanup_handles;
}
// TODO: Check if dimensions have changed by comparing width and height to previous time this was called.
// TODO: Support other plane formats than rgb (with multiple planes, such as direct YUV420 on wayland).
int x = 0, y = 0, src_x = 0, src_y = 0, src_w = 0, src_h = 0;
gsr_kms_rotation rotation = KMS_ROT_0;
const uint32_t property_mask = plane_get_properties(drm->drmfd, plane->plane_id, &x, &y, &src_x, &src_y, &src_w, &src_h, &rotation);
if(!(property_mask & PLANE_PROPERTY_IS_PRIMARY) && !(property_mask & PLANE_PROPERTY_IS_CURSOR))
continue;
int fb_fds[GSR_KMS_MAX_DMA_BUFS];
const int num_fb_fds = drm_prime_handles_to_fds(drm, drmfb, fb_fds);
if(num_fb_fds == 0) {
response->result = KMS_RESULT_FAILED_TO_GET_PLANE;
snprintf(response->err_msg, sizeof(response->err_msg), "failed to get fd from drm handle, error: %s", strerror(errno));
fprintf(stderr, "kms server error: %s\n", response->err_msg);
goto cleanup_handles;
}
const int item_index = response->num_items;
const connector_crtc_pair *crtc_pair = get_connector_pair_by_crtc_id(&c2crtc_map, plane->crtc_id);
if(crtc_pair && crtc_pair->hdr_metadata_blob_id) {
response->items[item_index].has_hdr_metadata = get_hdr_metadata(drm->drmfd, crtc_pair->hdr_metadata_blob_id, &response->items[item_index].hdr_metadata);
} else {
response->items[item_index].has_hdr_metadata = false;
}
for(int j = 0; j < num_fb_fds; ++j) {
response->items[item_index].dma_buf[j].fd = fb_fds[j];
response->items[item_index].dma_buf[j].pitch = drmfb->pitches[j];
response->items[item_index].dma_buf[j].offset = drmfb->offsets[j];
}
response->items[item_index].num_dma_bufs = num_fb_fds;
response->items[item_index].width = drmfb->width;
response->items[item_index].height = drmfb->height;
response->items[item_index].pixel_format = drmfb->pixel_format;
response->items[item_index].modifier = drmfb->flags & DRM_MODE_FB_MODIFIERS ? drmfb->modifier : DRM_FORMAT_MOD_INVALID;
response->items[item_index].connector_id = crtc_pair ? crtc_pair->connector_id : 0;
response->items[item_index].rotation = rotation;
response->items[item_index].is_cursor = property_mask & PLANE_PROPERTY_IS_CURSOR;
if(property_mask & PLANE_PROPERTY_IS_CURSOR) {
response->items[item_index].x = x;
response->items[item_index].y = y;
response->items[item_index].src_w = 0;
response->items[item_index].src_h = 0;
} else {
response->items[item_index].x = src_x;
response->items[item_index].y = src_y;
response->items[item_index].src_w = src_w;
response->items[item_index].src_h = src_h;
}
++response->num_items;
cleanup_handles:
drm_mode_cleanup_handles(drm->drmfd, drmfb);
next:
if(drmfb)
drmModeFreeFB2(drmfb);
if(plane)
drmModeFreePlane(plane);
}
done:
if(planes)
drmModeFreePlaneResources(planes);
if(response->num_items > 0)
response->result = KMS_RESULT_OK;
if(response->result == KMS_RESULT_OK) {
result = 0;
} else {
for(int i = 0; i < response->num_items; ++i) {
for(int j = 0; j < response->items[i].num_dma_bufs; ++j) {
gsr_kms_response_dma_buf *dma_buf = &response->items[i].dma_buf[j];
if(dma_buf->fd > 0) {
close(dma_buf->fd);
dma_buf->fd = -1;
}
}
response->items[i].num_dma_bufs = 0;
}
response->num_items = 0;
}
return result;
}
static double clock_get_monotonic_seconds(void) {
struct timespec ts;
ts.tv_sec = 0;
ts.tv_nsec = 0;
clock_gettime(CLOCK_MONOTONIC, &ts);
return (double)ts.tv_sec + (double)ts.tv_nsec * 0.000000001;
}
int main(int argc, char **argv) {
setlocale(LC_ALL, "C"); // Sigh... stupid C
int res = 0;
int socket_fd = 0;
gsr_drm drm;
drm.drmfd = 0;
if(argc != 3) {
fprintf(stderr, "usage: gsr-kms-server <domain_socket_path> <card_path>\n");
return 1;
}
const char *domain_socket_path = argv[1];
socket_fd = socket(AF_UNIX, SOCK_STREAM, 0);
if(socket_fd == -1) {
fprintf(stderr, "kms server error: failed to create socket, error: %s\n", strerror(errno));
return 2;
}
const char *card_path = argv[2];
drm.drmfd = open(card_path, O_RDONLY);
if(drm.drmfd < 0) {
fprintf(stderr, "kms server error: failed to open %s, error: %s", card_path, strerror(errno));
res = 2;
goto done;
}
if(drmSetClientCap(drm.drmfd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1) != 0) {
fprintf(stderr, "kms server error: drmSetClientCap DRM_CLIENT_CAP_UNIVERSAL_PLANES failed, error: %s\n", strerror(errno));
res = 2;
goto done;
}
if(drmSetClientCap(drm.drmfd, DRM_CLIENT_CAP_ATOMIC, 1) != 0) {
fprintf(stderr, "kms server warning: drmSetClientCap DRM_CLIENT_CAP_ATOMIC failed, error: %s. The wrong monitor may be captured as a result\n", strerror(errno));
}
fprintf(stderr, "kms server info: connecting to the client\n");
bool connected = false;
const double connect_timeout_sec = 5.0;
const double start_time = clock_get_monotonic_seconds();
while(clock_get_monotonic_seconds() - start_time < connect_timeout_sec) {
struct sockaddr_un remote_addr = {0};
remote_addr.sun_family = AF_UNIX;
snprintf(remote_addr.sun_path, sizeof(remote_addr.sun_path), "%s", domain_socket_path);
// TODO: Check if parent disconnected
if(connect(socket_fd, (struct sockaddr*)&remote_addr, sizeof(remote_addr.sun_family) + strlen(remote_addr.sun_path)) == -1) {
if(errno == ECONNREFUSED || errno == ENOENT) {
goto next;
} else if(errno == EISCONN) {
connected = true;
break;
}
fprintf(stderr, "kms server error: connect failed, error: %s (%d)\n", strerror(errno), errno);
res = 2;
goto done;
}
next:
usleep(30 * 1000); // 30 milliseconds
}
if(connected) {
fprintf(stderr, "kms server info: connected to the client\n");
} else {
fprintf(stderr, "kms server error: failed to connect to the client in %f seconds\n", connect_timeout_sec);
res = 2;
goto done;
}
for(;;) {
gsr_kms_request request;
request.version = 0;
request.type = -1;
request.new_connection_fd = 0;
const int recv_res = recv_msg_from_client(socket_fd, &request);
if(recv_res == 0) {
fprintf(stderr, "kms server info: kms client shutdown, shutting down the server\n");
res = 3;
goto done;
} else if(recv_res == -1) {
const int err = errno;
fprintf(stderr, "kms server error: failed to read all data in client request (error: %s), ignoring\n", strerror(err));
if(err == EBADF) {
fprintf(stderr, "kms server error: invalid client fd, shutting down the server\n");
res = 3;
goto done;
}
continue;
}
if(request.version != GSR_KMS_PROTOCOL_VERSION) {
fprintf(stderr, "kms server error: expected gpu screen recorder protocol version to be %u, but it's %u. please reinstall gpu screen recorder\n", GSR_KMS_PROTOCOL_VERSION, request.version);
/*
if(request.new_connection_fd > 0)
close(request.new_connection_fd);
*/
continue;
}
switch(request.type) {
case KMS_REQUEST_TYPE_REPLACE_CONNECTION: {
gsr_kms_response response;
response.version = GSR_KMS_PROTOCOL_VERSION;
response.num_items = 0;
if(request.new_connection_fd > 0) {
if(socket_fd > 0)
close(socket_fd);
socket_fd = request.new_connection_fd;
response.result = KMS_RESULT_OK;
if(send_msg_to_client(socket_fd, &response) == -1)
fprintf(stderr, "kms server error: failed to respond to client KMS_REQUEST_TYPE_REPLACE_CONNECTION request\n");
} else {
response.result = KMS_RESULT_INVALID_REQUEST;
snprintf(response.err_msg, sizeof(response.err_msg), "received invalid connection fd");
fprintf(stderr, "kms server error: %s\n", response.err_msg);
if(send_msg_to_client(socket_fd, &response) == -1)
fprintf(stderr, "kms server error: failed to respond to client request\n");
}
break;
}
case KMS_REQUEST_TYPE_GET_KMS: {
gsr_kms_response response;
response.version = GSR_KMS_PROTOCOL_VERSION;
response.num_items = 0;
if(kms_get_fb(&drm, &response) == 0) {
if(send_msg_to_client(socket_fd, &response) == -1)
fprintf(stderr, "kms server error: failed to respond to client KMS_REQUEST_TYPE_GET_KMS request\n");
} else {
if(send_msg_to_client(socket_fd, &response) == -1)
fprintf(stderr, "kms server error: failed to respond to client KMS_REQUEST_TYPE_GET_KMS request\n");
}
for(int i = 0; i < response.num_items; ++i) {
for(int j = 0; j < response.items[i].num_dma_bufs; ++j) {
gsr_kms_response_dma_buf *dma_buf = &response.items[i].dma_buf[j];
if(dma_buf->fd > 0) {
close(dma_buf->fd);
dma_buf->fd = -1;
}
}
response.items[i].num_dma_bufs = 0;
}
response.num_items = 0;
break;
}
default: {
gsr_kms_response response;
response.version = GSR_KMS_PROTOCOL_VERSION;
response.result = KMS_RESULT_INVALID_REQUEST;
response.num_items = 0;
snprintf(response.err_msg, sizeof(response.err_msg), "invalid request type %d, expected %d (%s)", request.type, KMS_REQUEST_TYPE_GET_KMS, "KMS_REQUEST_TYPE_GET_KMS");
fprintf(stderr, "kms server error: %s\n", response.err_msg);
if(send_msg_to_client(socket_fd, &response) == -1)
fprintf(stderr, "kms server error: failed to respond to client request\n");
break;
}
}
}
done:
if(drm.drmfd > 0)
close(drm.drmfd);
if(socket_fd > 0)
close(socket_fd);
return res;
}