<NME> mod.rs
<BEF> //! This module represents abstraction on top the linux direct rendering manager api (drm).
//!
//! ## [`DrmDevice`]
//!
//! A device exposes certain properties, which are directly derived
//! from the *device* as perceived by the direct rendering manager api (drm). These resources consists
//! out of connectors, encoders, framebuffers, planes and crtcs.
//!
//! [`crtc`](drm::control::crtc)s represent scanout engines of the device pointer to one framebuffer.
//! Their responsibility is to read the data of the framebuffer and export it into an "Encoder".
//! The number of crtc's represent the number of independent output devices the hardware may handle.
//!
//! On modern graphic cards it is better to think about the `crtc` as some sort of rendering engine.
//! You can only have so many different pictures, you may display, as you have `crtc`s, but a single image
//! may be put onto multiple displays.
//!
//! An [`encoder`](drm::control::encoder) encodes the data of connected crtcs into a video signal for a fixed set of connectors.
//! E.g. you might have an analog encoder based on a DAG for VGA ports, but another one for digital ones.
//! Also not every encoder might be connected to every crtc.
//!
//! A [`connector`](drm::control::connector) represents a port on your computer, possibly with a connected monitor, TV, capture card, etc.
//!
//! A [`framebuffer`](drm::control::framebuffer) represents a buffer you may display, see `DrmSurface` below.
//!
//! A [`plane`](drm::control::plane) adds another layer on top of the crtcs, which allow us to layer multiple images on top of each other more efficiently
//! then by combining the rendered images in the rendering phase, e.g. via OpenGL. Planes have to be explicitly used by the user to be useful.
//! Every device has at least one primary plane used to display an image to the whole crtc. Additionally cursor and overlay planes may be present.
//! Cursor planes are usually very restricted in size and meant to be used for hardware cursors, while overlay planes may
//! be used for performance reasons to display any overlay on top of the image, e.g. the top-most windows.
//! Overlay planes may have a bunch of weird limitation, that you cannot query, e.g. only working on round pixel coordinates.
//! You code should never rely on a fixed set of overlay planes, but always have a fallback solution in place.
//!
//! The main functionality of a `Device` in smithay is to give access to all these properties for the user to
//! choose an appropriate rendering configuration. What that means is defined by the requirements and constraints documented
//! in the specific device implementations. The second functionality is the creation of a `Surface`.
//! Surface creation requires a `crtc` (which cannot be the same as another existing `Surface`'s crtc), a plane,
//! as well as a `Mode` and a set of `connectors`.
//!
//! smithay does not make sure that `connectors` are not already in use by another `Surface`. Overlapping `connector`-Sets may
//! be an error or result in undefined rendering behavior depending on the `Surface` implementation.
//!
//! ## [`DrmSurface`]
//!
//! A surface is a part of a `Device` that may output a picture to a number of connectors. It pumps pictures of buffers to outputs.
//!
//! On surface creation a matching encoder for your `connector` is automatically selected, if one exists(!),
//! which means you still need to check your configuration beforehand, even if you do not need to provide an encoder.
//!
//! A surface consists of one `crtc` that is rendered to by the user. This is fixed for the `Surface`s lifetime and cannot be changed.
//! A surface also always needs at least one connector to output the resulting image to as well as a `Mode` that is valid for the given connectors.
//!
//! The state of a `Surface` is double-buffered, meaning all operations that chance the set of `connector`s or their `Mode` are stored and
//! only applied on the next commit. `Surface`s do their best to validate these changes, if possible.
//!
//! A commit/page_flip may be triggered to apply the pending state.
//!
//! ## Rendering
//!
//! The drm infrastructure makes no assumptions about the used renderer and does not interface with them directly.
//! It just provides a way to create framebuffers from various buffer types (mainly `DumbBuffer`s and hardware-backed gbm `BufferObject`s).
//!
//! Buffer management and details about the various types can be found in the [`allocator`-Module](crate::backend::allocator) and
//! rendering abstractions, which can target these buffers can be found in the [`renderer`-Module](crate::backend::renderer).
//!
//! ## [`DrmNode`]
//!
//! A drm node refers to a drm device and the capabilities that may be performed using the node.
//! Generally [`DrmNode`] is primarily used by clients (such as the output backends) which need
//! to allocate buffers for use in X11 or Wayland. If you need to do mode setting, you should use
//! [`DrmDevice`] instead.

pub(crate) mod device;
pub(self) mod error;
pub mod node;

#[cfg(feature = "backend_session")]
pub(self) mod session;
pub(self) mod surface;

pub use device::{DevPath, DrmDevice, DrmEvent, EventMetadata as DrmEventMetadata, Time as DrmEventTime};
pub use error::Error as DrmError;
pub use node::{CreateDrmNodeError, DrmNode, NodeType};
#[cfg(feature = "backend_gbm")]
pub use surface::gbm::{Error as GbmBufferedSurfaceError, GbmBufferedSurface};
pub use surface::DrmSurface;

use drm::control::{crtc, plane, Device as ControlDevice, PlaneType};

/// A set of planes as supported by a crtc
#[derive(Debug)]
pub struct Planes {
    /// The primary plane of the crtc (automatically selected for [DrmDevice::create_surface])
    pub primary: plane::Handle,
    /// The cursor plane of the crtc, if available
    pub cursor: Option<plane::Handle>,
    /// Overlay planes supported by the crtc, if available
    pub overlay: Vec<plane::Handle>,
}

fn planes(
    dev: &impl ControlDevice,
    crtc: &crtc::Handle,
    has_universal_planes: bool,
) -> Result<Planes, DrmError> {
    let mut primary = None;
    let mut cursor = None;
    let mut overlay = Vec::new();

    let planes = dev.plane_handles().map_err(|source| DrmError::Access {
        errmsg: "Error loading plane handles",
        dev: dev.dev_path(),
        source,
    })?;

    let resources = dev.resource_handles().map_err(|source| DrmError::Access {
        errmsg: "Error loading resource handles",
        dev: dev.dev_path(),
        source,
    })?;

    for plane in planes {
        let info = dev.get_plane(plane).map_err(|source| DrmError::Access {
            errmsg: "Failed to get plane information",
            dev: dev.dev_path(),
            source,
        })?;
        let filter = info.possible_crtcs();
        if resources.filter_crtcs(filter).contains(crtc) {
            match plane_type(dev, plane)? {
                PlaneType::Primary => {
                    primary = Some(plane);
                }
                PlaneType::Cursor => {
                    cursor = Some(plane);
                }
                PlaneType::Overlay => {
                    overlay.push(plane);
                }
            };
        }
    }

    Ok(Planes {
        primary: primary.expect("Crtc has no primary plane"),
        cursor: if has_universal_planes { cursor } else { None },
        overlay: if has_universal_planes { overlay } else { Vec::new() },
    })
}

fn plane_type(dev: &impl ControlDevice, plane: plane::Handle) -> Result<PlaneType, DrmError> {
    let props = dev.get_properties(plane).map_err(|source| DrmError::Access {
        errmsg: "Failed to get properties of plane",
        dev: dev.dev_path(),
        source,
    })?;
    let (ids, vals) = props.as_props_and_values();
    for (&id, &val) in ids.iter().zip(vals.iter()) {
        let info = dev.get_property(id).map_err(|source| DrmError::Access {
            errmsg: "Failed to get property info",
            dev: dev.dev_path(),
            source,
        })?;
        if info.name().to_str().map(|x| x == "type").unwrap_or(false) {
            return Ok(match val {
                x if x == (PlaneType::Primary as u64) => PlaneType::Primary,
                x if x == (PlaneType::Cursor as u64) => PlaneType::Cursor,
                _ => PlaneType::Overlay,
            });
        }
    }
    unreachable!()
}
    device_id: dev_t,
    backends: HashMap<crtc::Handle, Weak<DrmBackendInternal<A>>>,
    active: bool,
    logger: ::slog::Logger,
}

            device_id,
            old_state: HashMap::new(),
            active: true,
            logger: log.clone(),
        };

        info!(log, "DrmDevice initializing");

        // we want to mode-set, so we better be the master
        drm.set_master().chain_err(|| ErrorKind::DrmMasterFailed)?;

        let res_handles = drm.resource_handles().chain_err(|| {
            ErrorKind::DrmDev(format!(
                );
            }
        }
        if let Err(err) = self.drop_master() {
            error!(
                self.logger,
                "Failed to drop drm master state. Error: {}", err
            );
        }
    }
}
               }
        }
        device.active = false;
        if let Err(err) = device.drop_master() {
            error!(
                device.logger,
                "Failed to drop drm master state. Error: {}", err
            );
        }
    }

            {
               return;
           } else if let Some(fd) = fd {
               nix::unistd::dup2(device.as_raw_fd(), fd).expect("Failed to replace file descriptor of drm device");
           }
        }
        device.active = true;
        if let Err(err) = device.set_master() {
            crit!(
                device.logger,
                "Failed to acquire drm master again. Error: {}",
                err
            );
        }
        let mut crtcs = Vec::new();
        for (crtc, backend) in device.backends.iter() {

<MSG> Fix trying to become drm master on logind session

<DFF> @@ -251,6 +251,7 @@ pub struct DrmDevice<A: ControlDevice + 'static> {
     device_id: dev_t,
     backends: HashMap<crtc::Handle, Weak<DrmBackendInternal<A>>>,
     active: bool,
+    priviledged: bool,
     logger: ::slog::Logger,
 }
 
@@ -319,13 +320,17 @@ impl<A: ControlDevice + 'static> DrmDevice<A> {
             device_id,
             old_state: HashMap::new(),
             active: true,
+            priviledged: true,
             logger: log.clone(),
         };
 
         info!(log, "DrmDevice initializing");
 
-        // we want to mode-set, so we better be the master
-        drm.set_master().chain_err(|| ErrorKind::DrmMasterFailed)?;
+        // we want to mode-set, so we better be the master, if we run via a tty session
+        if let Err(_) = drm.set_master() {
+            warn!(log, "Unable to become drm master, assuming unpriviledged mode");
+            drm.priviledged = false;
+        };
 
         let res_handles = drm.resource_handles().chain_err(|| {
             ErrorKind::DrmDev(format!(
@@ -506,11 +511,13 @@ impl<A: ControlDevice + 'static> Drop for DrmDevice<A> {
                 );
             }
         }
-        if let Err(err) = self.drop_master() {
-            error!(
-                self.logger,
-                "Failed to drop drm master state. Error: {}", err
-            );
+        if self.priviledged {
+            if let Err(err) = self.drop_master() {
+                error!(
+                    self.logger,
+                    "Failed to drop drm master state. Error: {}", err
+                );
+            }
         }
     }
 }
@@ -606,11 +613,13 @@ impl<A: ControlDevice + 'static> SessionObserver for StateToken<DrmDevice<A>> {
                }
         }
         device.active = false;
-        if let Err(err) = device.drop_master() {
-            error!(
-                device.logger,
-                "Failed to drop drm master state. Error: {}", err
-            );
+        if device.priviledged {
+            if let Err(err) = device.drop_master() {
+                error!(
+                    device.logger,
+                    "Failed to drop drm master state. Error: {}", err
+                );
+            }
         }
     }
 
@@ -622,16 +631,19 @@ impl<A: ControlDevice + 'static> SessionObserver for StateToken<DrmDevice<A>> {
             {
                return;
            } else if let Some(fd) = fd {
+               info!(device.logger, "Replacing fd");
                nix::unistd::dup2(device.as_raw_fd(), fd).expect("Failed to replace file descriptor of drm device");
            }
         }
         device.active = true;
-        if let Err(err) = device.set_master() {
-            crit!(
-                device.logger,
-                "Failed to acquire drm master again. Error: {}",
-                err
-            );
+        if device.priviledged {
+            if let Err(err) = device.set_master() {
+                crit!(
+                    device.logger,
+                    "Failed to acquire drm master again. Error: {}",
+                    err
+                );
+            }
         }
         let mut crtcs = Vec::new();
         for (crtc, backend) in device.backends.iter() {

Fix trying to become drm master on logind session