#!/usr/bin/env python3 import argparse import hashlib import json import os import re import shutil import subprocess import stat import sys import time from glob import glob from typing import List, Literal, Dict, Tuple, TypedDict, TextIO, Optional IN_NIX_STORE = False CACHE_VERSION = 3 if IN_NIX_STORE: # The following paths are meant to be substituted by Nix at build # time. PATCHELF_PATH = "@patchelf-bin@" else: PATCHELF_PATH = "patchelf" class ResolvedLib: """This data type encapsulate one host dynamically shared object together with some metadata helping us to uniquely identify it.""" def __init__( self, name: str, dirpath: str, fullpath: str, last_modification: Optional[float] = None, size: Optional[int] = None, ): self.name: str = name self.dirpath: str = dirpath self.fullpath: str = fullpath if size is None or last_modification is None: stat = os.stat(fullpath) self.last_modification: float = stat.st_atime self.size: int = stat.st_size else: self.last_modification = last_modification self.size = size def __repr__(self): return f"ResolvedLib<{self.name}, {self.dirpath}, {self.fullpath}, {self.last_modification}, {self.size}>" def to_dict(self) -> Dict: return { "name": self.name, "dirpath": self.dirpath, "fullpath": self.fullpath, "last_modification": self.last_modification, "size": self.size, } def __hash__(self): return hash( (self.name, self.dirpath, self.fullpath, self.last_modification, self.size) ) def __eq__(self, o): return ( self.name == o.name and self.fullpath == o.fullpath and self.dirpath == o.dirpath and self.last_modification == o.last_modification and self.size == o.size ) @classmethod def from_dict(cls, d: Dict): return ResolvedLib( d["name"], d["dirpath"], d["fullpath"], d["last_modification"], d["size"] ) class LibraryPath: """This data type encapsulates a directory containing some GL/Cuda dynamically shared objects.""" def __init__( self, glx: List[ResolvedLib], cuda: List[ResolvedLib], generic: List[ResolvedLib], egl: List[ResolvedLib], path: str, ): self.glx = glx self.cuda = cuda self.generic = generic self.egl = egl self.path = path def __eq__(self, other): return ( set(self.glx) == set(other.glx) and set(self.cuda) == set(other.cuda) and set(self.generic) == set(other.generic) and set(self.egl) == set(other.egl) and self.path == other.path ) def __hash__(self): return hash( ( tuple(self.glx), tuple(self.cuda), tuple(self.generic), tuple(self.egl), self.path, ) ) def to_dict(self) -> Dict: return { "glx": [v.to_dict() for v in self.glx], "cuda": [v.to_dict() for v in self.cuda], "generic": [v.to_dict() for v in self.generic], "egl": [v.to_dict() for v in self.egl], "path": self.path, } @classmethod def from_dict(cls, d: Dict): return LibraryPath( glx=[ResolvedLib.from_dict(v) for v in d["glx"]], cuda=[ResolvedLib.from_dict(v) for v in d["cuda"]], generic=[ResolvedLib.from_dict(v) for v in d["generic"]], egl=[ResolvedLib.from_dict(v) for v in d["egl"]], path=d["path"], ) class CacheDirContent: """This datatype encapsulates all the dynamically shared objects living in the nix-gl-host cache. We mostly use it to serialize what's in the cache on the disk and compare this content to what we scanned in the host system.""" def __init__(self, paths: List[LibraryPath], version: int = CACHE_VERSION): self.paths: List[LibraryPath] = paths self.version: int = CACHE_VERSION def to_json(self): d = {"paths": [p.to_dict() for p in self.paths], "version": self.version} return json.dumps(d, sort_keys=True) def __eq__(self, o): return self.version == o.version and set(self.paths) == set(o.paths) @classmethod def from_json(cls, j: str): d: Dict = json.loads(j) return CacheDirContent( version=d["version"], paths=[LibraryPath.from_dict(p) for p in d["paths"]] ) # The following regexes list has been figured out by looking at the # output of nix-build -A linuxPackages.nvidia_x11 before running # ls ./result/lib | grep -E ".so$". # # TODO: find a more systematic way to figure out these names *not # requiring to build/fetch the nvidia driver at runtime*. # TODO: compile the regexes NVIDIA_DSO_PATTERNS = [ "libEGL_nvidia\.so.*$", "libGLESv1_CM_nvidia\.so.*$", "libGLESv2_nvidia\.so.*$", "libglxserver_nvidia\.so.*$", "libnvcuvid\.so.*$", "libnvidia-allocator\.so.*$", "libnvidia-cfg\.so.*$", "libnvidia-compiler\.so.*$", "libnvidia-eglcore\.so.*$", "libnvidia-egl-gbm\.so.*$", "libnvidia-egl-wayland\.so.*$", "libnvidia-encode\.so.*$", "libnvidia-fbc\.so.*$", "libnvidia-glcore\.so.*$", "libnvidia-glsi\.so.*$", "libnvidia-glvkspirv\.so.*$", "libnvidia-ml\.so.*$", "libnvidia-ngx\.so.*$", "libnvidia-nvvm\.so.*$", "libnvidia-opencl\.so.*$", "libnvidia-opticalflow\.so.*$", "libnvidia-ptxjitcompiler\.so.*$", "libnvidia-rtcore\.so.*$", "libnvidia-tls\.so.*$", "libnvidia-vulkan-producer\.so.*$", "libnvidia-wayland-client\.so.*$", "libnvoptix\.so.*$", # Cannot find that one :( "libnvtegrahv\.so.*$", # Host dependencies required by the nvidia DSOs to properly # operate # libdrm "libdrm\.so.*$", # libffi "libffi\.so.*$", # libgbm "libgbm\.so.*$", # libexpat "libexpat\.so.*$", # libxcb "libxcb-glx\.so.*$", # Coming from libx11 "libX11-xcb\.so.*$", "libX11\.so.*$", "libXext\.so.*$", # libwayland "libwayland-server\.so.*$", "libwayland-client\.so.*$", ] CUDA_DSO_PATTERNS = ["libcudadebugger\.so.*$", "libcuda\.so.*$"] GLX_DSO_PATTERNS = ["libGLX_nvidia\.so.*$"] EGL_DSO_PATTERNS = [ "libEGL_nvidia\.so.*$", "libnvidia-egl-wayland\.so.*$", "libnvidia-egl-gbm\.so.*$", ] def get_ld_paths() -> List[str]: """ Vendored from https://github.com/albertz/system-tools/blob/master/bin/find-lib-in-path.py Find all the directories pointed by LD_LIBRARY_PATH and the ld cache.""" def parse_ld_conf_file(fn: str) -> List[str]: paths = [] for l in open(fn).read().splitlines(): l = l.strip() if not l: continue if l.startswith("#"): continue if l.startswith("include "): dirglob = l[len("include ") :] if dirglob[0] != "/": dirglob = os.path.dirname(os.path.normpath(fn)) + "/" + dirglob for sub_fn in glob(dirglob): paths.extend(parse_ld_conf_file(sub_fn)) continue paths.append(l) return paths LDPATH = os.getenv("LD_LIBRARY_PATH") PREFIX = os.getenv("PREFIX") # Termux & etc. paths = [] if LDPATH: paths.extend(LDPATH.split(":")) if os.path.exists("/etc/ld.so.conf"): paths.extend(parse_ld_conf_file("/etc/ld.so.conf")) else: print('WARNING: file "/etc/ld.so.conf" not found.') if PREFIX: if os.path.exists(PREFIX + "/etc/ld.so.conf"): paths.extend(parse_ld_conf_file(PREFIX + "/etc/ld.so.conf")) else: print('WARNING: file "' + PREFIX + '/etc/ld.so.conf" not found.') paths.extend( [ PREFIX + "/lib", PREFIX + "/usr/lib", PREFIX + "/lib64", PREFIX + "/usr/lib64", ] ) paths.extend(["/lib", "/usr/lib", "/lib64", "/usr/lib64"]) return [path for path in paths if os.path.isdir(path)] def resolve_libraries(path: str, files_patterns: List[str]) -> List[ResolvedLib]: """Scans the PATH directory looking for the files complying with the FILES_PATTERNS regexes list. Returns the list of the resolved DSOs.""" libraries: List[ResolvedLib] = [] def is_dso_matching_pattern(filename): for pattern in files_patterns: if re.search(pattern, filename): return True return False for fname in os.listdir(path): abs_file_path = os.path.abspath(os.path.join(path, fname)) if os.path.isfile(abs_file_path) and is_dso_matching_pattern(abs_file_path): libraries.append( ResolvedLib(name=fname, dirpath=path, fullpath=abs_file_path) ) return libraries def copy_and_patch_libs( dsos: List[ResolvedLib], dest_dir: str, rpath: Optional[str] = None ) -> None: """Copies the graphic vendor DSOs to the cache directory before patchelf-ing them. The DSOs can dlopen each other. Sadly, we don't want any host libraries to the LD_LIBRARY_PATH to prevent polluting the nix binary env. The only option left is to patch their ELFs runpath to point to RPATH. We also don't want to directly modify the host DSOs. In the end, we first copy them to the user's personal cache directory, we then alter their runpath to point to the cache directory.""" rpath = rpath if (rpath is not None) else dest_dir for dso in dsos: basename = os.path.basename(dso.fullpath) newpath = os.path.join(dest_dir, basename) log_info(f"Copying and patching {dso} to {newpath}") shutil.copyfile(dso.fullpath, newpath) # Provide write permissions to ensure we can patch this binary. os.chmod(newpath, os.stat(dso.fullpath).st_mode | stat.S_IWUSR) patch_dso(newpath, rpath) def log_info(string: str) -> None: """Prints STR to STDERR if the DEBUG environment variable is set.""" if "DEBUG" in os.environ: print(f"[+] {string}", file=sys.stderr) def patch_dso(dsoPath: str, rpath: str) -> None: """Call patchelf to change the DSOPATH runpath with RPATH.""" log_info(f"Patching {dsoPath}") log_info(f"Exec: {PATCHELF_PATH} --set-rpath {rpath} {dsoPath}") res = subprocess.run([PATCHELF_PATH, "--set-rpath", rpath, dsoPath]) if res.returncode != 0: raise BaseException( f"Cannot patch {dsoPath}. Patchelf exited with {res.returncode}" ) def generate_nvidia_egl_config_files(egl_conf_dir: str) -> None: """Generates a set of JSON files describing the EGL exec envirnoment to libglvnd. These configuration files will point to the EGL, wayland and GBM Nvidia DSOs. We're only specifying the DSOs names here to give the linker enough legroom to load the most appropriate DSO from the LD_LIBRARY_PATH.""" def generate_egl_conf_json(dso): return json.dumps( {"file_format_version": "1.0.0", "ICD": {"library_path": dso}} ) dso_paths = [ ("10_nvidia.json", f"libEGL_nvidia.so.0"), ("10_nvidia_wayland.json", f"libnvidia-egl-wayland.so.1"), ("15_nvidia_gbm.json", f"libnvidia-egl-gbm.so.1"), ] for (conf_file_name, dso_name) in dso_paths: os.makedirs(egl_conf_dir, exist_ok=True) with open( os.path.join(egl_conf_dir, conf_file_name), "w", encoding="utf-8" ) as f: log_info(f"Writing {dso_name} conf to {egl_conf_dir}") f.write(generate_egl_conf_json(dso_name)) def is_dso_cache_up_to_date(dsos: CacheDirContent, cache_file_path: str) -> bool: """Check whether or not we need to update the cache. We keep what's in the cache through a JSON file stored at the root of the cache_dir. We consider a dynamically shared object to be up to date if its name, its full path, its size and last modification timestamp are equivalent.""" log_info("Checking if the cache is up to date") if os.path.isfile(cache_file_path): with open(cache_file_path, "r", encoding="utf8") as f: try: cached_dsos: CacheDirContent = CacheDirContent.from_json(f.read()) except: return False return dsos == cached_dsos return False def scan_dsos_from_dir(path: str) -> Optional[LibraryPath]: """Look for the different kind of DSOs we're searching in a particular library path. This will match and hash the content of each object we're interested in.""" generic = resolve_libraries(path, NVIDIA_DSO_PATTERNS) if len(generic) > 0: cuda = resolve_libraries(path, CUDA_DSO_PATTERNS) glx = resolve_libraries(path, GLX_DSO_PATTERNS) egl = resolve_libraries(path, EGL_DSO_PATTERNS) return LibraryPath(glx=glx, cuda=cuda, generic=generic, egl=egl, path=path) else: return None def cache_library_path(library_path: LibraryPath, cache_dir_root: str) -> str: """Generate a cache directory for the LIBRARY_PATH host directory. This cache directory is mirroring the host directory containing the graphics card drivers. Its full name is hashed: it's an attempt to keep the final LD_LIBRARY_PATH reasonably sized. Returns the full path of the cache directory created by this function.""" # Hash Computation h = hashlib.sha256() h.update(library_path.path.encode("utf8")) path_hash: str = h.hexdigest() # Paths cache_path_root: str = os.path.join(cache_dir_root, path_hash) lib_dir = os.path.join(cache_path_root, "lib") cuda_dir = os.path.join(cache_path_root, "cuda") egl_dir = os.path.join(cache_path_root, "egl") glx_dir = os.path.join(cache_path_root, "glx") # Copy and patch DSOs for dsos, d in [ (library_path.generic, lib_dir), (library_path.cuda, cuda_dir), (library_path.egl, egl_dir), (library_path.glx, glx_dir), ]: os.makedirs(d, exist_ok=True) copy_and_patch_libs(dsos=dsos, dest_dir=d, rpath=lib_dir) return cache_path_root def generate_cache_ld_library_path(cache_paths: List[str]) -> str: """Generates the LD_LIBRARY_PATH colon-separated string pointing to the cached DSOs living inside the CACHE_PATHS. CACHE_PATH being a list pointing to the root of all the cached library paths. """ ld_library_paths: List[str] = [] for path in cache_paths: ld_library_paths = ld_library_paths + [ f"{path}/glx", f"{path}/cuda", f"{path}/egl", ] return ":".join(ld_library_paths) def nvidia_main( cache_dir: str, dso_vendor_paths: List[str], print_ld_library_path: bool = False ) -> Dict: """Prepares the environment necessary to run a opengl/cuda program on a Nvidia graphics card. It is by definition really stateful. Roughly, we're going to: 1. Setup the nvidia cache directory. 2. Find the nvidia DSOs in the DSO_VENDOR_PATHS directories. 3. Copy these DSOs to their appropriate cache directories. 4. Generate the EGL configuration files. 5. Patchelf the runpath of what needs to be patched. 6. Generate the env variables the main process is supposed to set. Keep in mind we want to keep the host system out of the LD_LIBRARY_PATH to make sure we won't inject any host DSOs (other than the GL/Cuda ones OFC) to the nix-built program. We're isolating the main DSOs for GLX/EGL/Cuda in their own dirs, add add these directory to the LD_LIBRARY_PATH. We patch their runpaths to point to the generic cache dir, containing all the libraries we don't want to expose to the program we're wrapping. This function returns a dictionary containing the env variables supposed to be added to the current process down the line.""" log_info("Nvidia routine begins") # Find Host DSOS log_info("Searching for the host DSOs") cache_content: CacheDirContent = CacheDirContent(paths=[]) cache_file_path = os.path.join(cache_dir, "cache.json") cached_ld_library_path = os.path.join(cache_dir, "ld_library_path") paths = get_ld_paths() egl_conf_dir = os.path.join(cache_dir, "egl-confs") nix_gl_ld_library_path: Optional[str] = None # Cache/Patch DSOs for path in paths: res = scan_dsos_from_dir(path) if res: cache_content.paths.append(res) if not is_dso_cache_up_to_date( cache_content, cache_file_path ) or not os.path.isfile(cached_ld_library_path): log_info("The cache is not up to date, regenerating it") shutil.rmtree(cache_dir) cache_paths: List[str] = [] for p in cache_content.paths: np = cache_library_path(p, cache_dir) log_info(f"Caching {np}") log_info(f"p {p}") cache_paths.append(cache_library_path(p, cache_dir)) log_info(f"Caching ") with open(cache_file_path, "w", encoding="utf8") as f: f.write(cache_content.to_json()) nix_gl_ld_library_path = generate_cache_ld_library_path(cache_paths) log_info(f"Caching LD_LIBRARY_PATH: {nix_gl_ld_library_path}") with open(cached_ld_library_path, "w", encoding="utf8") as f: f.write(nix_gl_ld_library_path) generate_nvidia_egl_config_files(egl_conf_dir) else: log_info("The cache is up to date, re-using it.") with open(cached_ld_library_path, "r", encoding="utf8") as f: nix_gl_ld_library_path = f.read() assert nix_gl_ld_library_path, "The nix-host-gl LD_LIBRARY_PATH is not set" log_info(f"Injecting LD_LIBRARY_PATH: {nix_gl_ld_library_path}") os.makedirs(egl_conf_dir, exist_ok=True) new_env = {} log_info(f"__GLX_VENDOR_LIBRARY_NAME = nvidia") new_env["__GLX_VENDOR_LIBRARY_NAME"] = "nvidia" log_info(f"__EGL_VENDOR_LIBRARY_DIRS = {egl_conf_dir}") new_env["__EGL_VENDOR_LIBRARY_DIRS"] = egl_conf_dir ld_library_path = os.environ.get("LD_LIBRARY_PATH", None) if print_ld_library_path: print(nix_gl_ld_library_path) ld_library_path = ( nix_gl_ld_library_path if ld_library_path is None else f"{nix_gl_ld_library_path}:{ld_library_path}" ) log_info(f"LD_LIBRARY_PATH = {ld_library_path}") new_env["LD_LIBRARY_PATH"] = ld_library_path return new_env def exec_binary(bin_path: str, args: List[str]) -> None: """Replace the current python program with the program pointed by BIN_PATH. Sets the relevant libGLvnd env variables.""" log_info(f"Execv-ing {bin_path}") log_info(f"Goodbye now.") os.execvp(bin_path, [bin_path] + args) def main(args): start_time = time.time() home = os.path.expanduser("~") xdg_cache_home = os.environ.get("XDG_CACHE_HOME", os.path.join(home, ".cache")) cache_dir = os.path.join(xdg_cache_home, "nix-gl-host") log_info(f'Using "{cache_dir}" as cache dir.') os.makedirs(cache_dir, exist_ok=True) if args.driver_directory: log_info( f"Retreiving DSOs from the specified directory: {args.driver_directory}" ) host_dsos_paths: List[str] = [args.driver_directory] else: log_info("Retrieving DSOs from the load path.") host_dsos_paths: List[str] = get_ld_paths() new_env = nvidia_main(cache_dir, host_dsos_paths, args.print_ld_library_path) log_info(f"{time.time() - start_time} seconds elapsed since script start.") if args.NIX_BINARY: os.environ.update(new_env) exec_binary(args.NIX_BINARY, args.ARGS) return 0 if __name__ == "__main__": parser = argparse.ArgumentParser( prog="nixglhost-wrapper", description="Wrapper used to massage the host GL drivers to work with your nix-built binary.", ) parser.add_argument( "-d", "--driver-directory", type=str, help="Use the driver libraries contained in this directory instead of discovering them from the load path.", default=None, ) parser.add_argument( "-p", "--print-ld-library-path", action=argparse.BooleanOptionalAction, default=False, help="Print the GL/Cuda LD_LIBRARY_PATH env you should add to your environment.", ) parser.add_argument( "NIX_BINARY", type=str, nargs="?", help="Nix-built binary you'd like to wrap.", default=None, ) parser.add_argument( "ARGS", type=str, nargs="*", help="The args passed to the wrapped binary.", default=None, ) args = parser.parse_args() if args.print_ld_library_path and args.NIX_BINARY: print( "ERROR: -p and NIX_BINARY are both set. You have to choose between one of these options." ) print(" run nixglhost --help for more informations. ") sys.exit(1) elif not args.print_ld_library_path and not args.NIX_BINARY: print("ERROR: Please set the NIX_BINARY you want to run.") print(" run nixglhost --help for more informations. ") sys.exit(1) ret = main(args) sys.exit(ret)