#!/usr/bin/env python3 import argparse import hashlib import json import os import re import shutil import subprocess import sys import time from glob import glob from typing import List, Literal, Dict, Tuple, TypedDict, TextIO, Optional IN_NIX_STORE = False 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: def __init__(self, name: str, fullpath: str, sha256: Optional[str] = None): self.name: str = name self.fullpath: str = fullpath if sha256 is None: h = hashlib.sha256() with open(fullpath, "rb") as f: h.update(f.read()) sha: str = h.hexdigest() else: sha = sha256 self.sha256: str = sha def __repr__(self): return f"ResolvedLib<{self.name}, {self.fullpath}, {self.sha256}>" def to_dict(self) -> Dict: return {"name": self.name, "fullpath": self.fullpath, "sha256": self.sha256} def __eq__(self, o): return ( self.name == o.name and self.fullpath == o.fullpath and self.sha256 == o.sha256 ) @classmethod def from_dict(cls, d: Dict): return ResolvedLib(d["name"], d["fullpath"], d["sha256"]) class HostDSOs: def __init__( self, glx: Dict[str, ResolvedLib], cuda: Dict[str, ResolvedLib], generic: Dict[str, ResolvedLib], version: int = 1, ): self.glx = glx self.cuda = cuda self.generic = generic self.version = version def __eq__(self, other): return ( self.glx == other.glx and self.cuda == other.cuda and self.generic == other.generic and self.version == other.version ) def to_json(self) -> str: return json.dumps( { "version": 1, "glx": {k: v.to_dict() for k, v in self.glx.items()}, "cuda": {k: v.to_dict() for k, v in self.cuda.items()}, "generic": {k: v.to_dict() for k, v in self.generic.items()}, }, sort_keys=True, ) @classmethod def from_json(cls, o: str): d: Dict = json.loads(o) return HostDSOs( version=d["version"], glx={k: ResolvedLib.from_dict(v) for k, v in d["glx"].items()}, cuda={k: ResolvedLib.from_dict(v) for k, v in d["cuda"].items()}, generic={k: ResolvedLib.from_dict(v) for k, v in d["generic"].items()}, ) # 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$". # # TODO: find a more systematic way to figure out these names *not # requiring to build/fetch the nvidia driver at runtime*. NVIDIA_DSO_PATTERNS = [ "libEGL_nvidia\.so.*$", "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.*$", "libnvoptix\.so.*$", # Host dependencies required by the nvidia DSOs to properly # operate # libdrm "libdrm\.so.*$", # libffi "libffi\.so.*$", # libgbm "libgbm\.so.*$", # Cannot find that one :( "libnvtegrahv\.so.*$", # 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.*$"] GLX_DSO_PATTERNS = ["libGLX_nvidia\.so.*$"] 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( paths: List[str], files_patterns: List[str] ) -> Dict[str, ResolvedLib]: """Scans the PATH directory looking for the files complying with the FILES_PATTERNS regexes list. Each file matching the pattern will be found only once Returns the list of the resolved DSOs.""" libraries: Dict[str, ResolvedLib] = {} def is_dso_matching_pattern(filename): for pattern in files_patterns: if re.search(pattern, filename): return True return False for path in paths: 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) and (fname not in libraries) ): libraries[fname] = ResolvedLib(fname, abs_file_path) return libraries def copy_and_patch_libs(dsos: List[ResolvedLib], libs_dir: str, rpath=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, 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 libs_dir for dso in dsos: basename = os.path.basename(dso.fullpath) newpath = os.path.join(libs_dir, basename) log_info(f"Copying and patching {dso} to {newpath}") shutil.copyfile(dso.fullpath, newpath) shutil.copymode(dso.fullpath, newpath) 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}" ) # NOTE: is this the right abstraction? Looks like I'm stitching # some loosely connected parts together for no good reason. def generate_nvidia_egl_config_files( cache_dir: str, libs_dir: str, egl_conf_dir: str ) -> str: """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.""" 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"{libs_dir}/libEGL_nvidia.so.0"), ("10_nvidia_wayland.json", f"{libs_dir}/libnvidia-egl-wayland.so.1"), ("15_nvidia_gbm.json", f"{libs_dir}/libnvidia-egl-gbm.so.1"), ] for (conf_file_name, dso_path) in dso_paths: with open( os.path.join(egl_conf_dir, conf_file_name), "w", encoding="utf-8" ) as f: log_info(f"Writing {dso_path} conf to {egl_conf_dir}") f.write(generate_egl_conf_json(dso_path)) return egl_conf_dir def is_dso_cache_up_to_date(dsos: HostDSOs, cache_file_path: str) -> bool: """Check whether or not we need to udate the host DSOs cache. We keep what's in the cache through a JSON file stored at the root of the cache_dir. We consider a DSO to be up to date if its name and its content sha256 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: HostDSOs = HostDSOs.from_json(f.read()) except: return False return dsos == cached_dsos return False def nvidia_main(cache_dir: str, dso_vendor_paths: List[str]) -> 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_PATH. 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. Overall, we're using two different tricks to setup the GL/cuda envs: - For Cuda and GLX: we're isolating the main DSOs in their own dirs, add these dirs to the LD_LIBRARY_PATH and patch their runpath to point to the generic cache dir. - For EGL: we're generating some JSON configuration files. libglvnd will later use these configuration files to directly load the appropriate DSOs. We don't need any LD_LIBRARY_PATH-fueled trick. 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. 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") log_info("Setting up Nvidia cache directory") cache_dir = os.path.join(cache_dir, "nvidia") libs_dir = os.path.join(cache_dir, "lib") cuda_dir = os.path.join(cache_dir, "cuda") glx_dir = os.path.join(cache_dir, "glx") egl_dir = os.path.join(cache_dir, "egl-confs") cache_file_path = os.path.join(cache_dir, "cache.json") log_info(f"Nvidia libs dir: {libs_dir}") log_info(f"Nvidia cuda dir: {libs_dir}") os.makedirs(libs_dir, exist_ok=True) os.makedirs(cuda_dir, exist_ok=True) os.makedirs(glx_dir, exist_ok=True) os.makedirs(egl_dir, exist_ok=True) # Find Host DSOS log_info("Searching for the host DSOs") dsos: HostDSOs = HostDSOs( generic=resolve_libraries(dso_vendor_paths, NVIDIA_DSO_PATTERNS), cuda=resolve_libraries(dso_vendor_paths, CUDA_DSO_PATTERNS), glx=resolve_libraries(dso_vendor_paths, GLX_DSO_PATTERNS), ) log_info("Caching and patching host DSOs") # Cache/Patch DSOs if not is_dso_cache_up_to_date(dsos, cache_file_path): log_info("The cache is not up to date, regenerating it") shutil.rmtree(cache_dir) os.makedirs(libs_dir, exist_ok=True) os.makedirs(cuda_dir, exist_ok=True) os.makedirs(glx_dir, exist_ok=True) os.makedirs(egl_dir, exist_ok=True) copy_and_patch_libs(list(dsos.generic.values()), libs_dir, libs_dir) copy_and_patch_libs(list(dsos.glx.values()), glx_dir, libs_dir) copy_and_patch_libs(list(dsos.cuda.values()), cuda_dir, libs_dir) log_info("Setting up NVIDIA-specific execution env variables.") with open(cache_file_path, "w", encoding="utf8") as f: f.write(dsos.to_json()) else: log_info("The cache is up to date.") egl_config_files = generate_nvidia_egl_config_files(cache_dir, libs_dir, egl_dir) 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_config_files}") new_env["__EGL_VENDOR_LIBRARY_DIRS"] = egl_config_files ld_library_path = os.environ.get("LD_LIBRARY_PATH", None) nv_ld_library_path = f"{cuda_dir}:{glx_dir}" ld_library_path = ( nv_ld_library_path if ld_library_path is None else f"{nv_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.") # The following two env variables are required by our patched libglvnd # implementation to figure out what kind of driver the host # machine is using. os.execv(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) host_dsos_paths: List[str] = get_ld_paths() new_env = nvidia_main(cache_dir, host_dsos_paths) os.environ.update(new_env) log_info(f"{time.time() - start_time} seconds elapsed since script start.") 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( "NIX_BINARY", type=str, help="Nix-built binary you'd like to wrap.", ) parser.add_argument( "ARGS", type=str, nargs="*", help="The args passed to the wrapped binary.", ) args = parser.parse_args() ret = main(args) sys.exit(ret)