darling-dyld/chroot_util.cpp
2023-04-29 11:24:58 -07:00

211 lines
7.5 KiB
C++

/*
* Copyright (c) 2019 Apple Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* "Portions Copyright (c) 1999 Apple Computer, Inc. All Rights
* Reserved. This file contains Original Code and/or Modifications of
* Original Code as defined in and that are subject to the Apple Public
* Source License Version 1.0 (the 'License'). You may not use this file
* except in compliance with the License. Please obtain a copy of the
* License at http://www.apple.com/publicsource and read it before using
* this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
* License for the specific language governing rights and limitations
* under the License."
*
* @APPLE_LICENSE_HEADER_END@
*/
#include <cassert>
#include <cstdio>
#include <cstring>
#include <fcntl.h>
#include <dirent.h>
#include <libgen.h>
#include <unistd.h>
#include <sys/attr.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <mach-o/fat.h>
#include <mach-o/loader.h>
#include <copyfile.h>
#include <set>
#include <string>
#include <vector>
#include <functional>
#include <filesystem>
#include "StringUtils.h"
#include "MachOFile.h"
std::set<std::string> scanForDependencies(const std::string& path) {
__block std::set<std::string> result;
struct stat stat_buf;
int fd = open(path.c_str(), O_RDONLY, 0);
if (fd == -1) {
return result;
}
if (fstat(fd, &stat_buf) == -1) {
close(fd);
return result;
}
const void* buffer = mmap(NULL, (size_t)stat_buf.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (buffer == MAP_FAILED) {
close(fd);
return result;
}
auto scanner = ^(const char *loadPath, bool isWeak, bool isReExport, bool isUpward, uint32_t compatVersion, uint32_t curVersion, bool &stop) {
if (isWeak) { return; } // We explicily avoid LC_LOAD_WEAK_DYLIB since we are trying to build a minimal chroot
if (loadPath[0] != '/') { return; } // Only include absolute dependencies
result.insert(loadPath);
};
Diagnostics diag;
if ( dyld3::FatFile::isFatFile(buffer) ) {
const dyld3::FatFile* ff = (dyld3::FatFile*)buffer;
ff->forEachSlice(diag, stat_buf.st_size, ^(uint32_t sliceCpuType, uint32_t sliceCpuSubType, const void* sliceStart, uint64_t sliceSize, bool& stop) {
const dyld3::MachOFile* mf = (dyld3::MachOFile*)sliceStart;
mf->forEachDependentDylib(scanner);
});
} else {
const dyld3::MachOFile* mf = (dyld3::MachOFile*)buffer;
if (mf->isMachO(diag, stat_buf.st_size)) {
mf->forEachDependentDylib(scanner);
}
}
close(fd);
return result;
}
std::string withoutPrefixPath(const std::string& path, const std::string& prefix ) {
std::string result = path;
size_t pos = result.find(prefix);
result.erase(pos, prefix.length());
return result;
}
void add_symlinks_to_dylib(const std::string path) {
static std::set<std::string> alreadyMatched;
size_t pos = path.rfind(".framework/Versions/");
auto prefixPath = path.substr(0, pos);
if (alreadyMatched.find(prefixPath) != alreadyMatched.end()) { return; }
if (pos == std::string::npos) { return; }
// fprintf(stderr, "PATH: %s\n", path.c_str());
size_t versionStart = pos+20;
size_t versionEnd = versionStart;
while (path[versionEnd] != '/') {
++versionEnd;
}
size_t frameworkNameBegin = pos;
while (path[frameworkNameBegin-1] != '/') {
--frameworkNameBegin;
}
auto frameworkName = path.substr(frameworkNameBegin, pos-frameworkNameBegin);
auto version = path.substr(versionStart, versionEnd-versionStart);
std::string mainLinkPath = prefixPath + ".framework/" + frameworkName;
std::string mainLinkTarget = "Versions/Current/" + frameworkName;
std::string versionLinkPath = prefixPath + ".framework/Versions/Current";
std::string versionLinkTarget = version;;
alreadyMatched.insert(prefixPath);
if (!std::filesystem::exists(versionLinkPath)) {
std::filesystem::create_symlink(version, versionLinkPath);
}
if (!std::filesystem::exists(mainLinkPath)) {
std::filesystem::create_symlink(mainLinkTarget, mainLinkPath);
}
}
void add_symlink(const std::string& target, const std::string& path) {
if (!std::filesystem::exists(path)) {
std::filesystem::create_symlink(target, path);
}
}
void buildChroot(const std::string& chroot, const std::string& fallback, const std::vector<std::string>& binaries) {
auto chrootPath = std::filesystem::path(chroot);
auto fallbackPath = std::filesystem::path(fallback);
for (const auto& binary : binaries) {
if (std::filesystem::exists(chroot + binary)) { continue; }
std::filesystem::create_directories(std::filesystem::path(chroot + binary).parent_path());
std::filesystem::copy(fallback + binary, chroot + binary);
}
bool foundNewEntries = true;
std::set<std::string> scannedFiles;
std::string devfsPath = chroot + "/dev";
while (foundNewEntries) {
foundNewEntries = false;
for(auto file = std::filesystem::recursive_directory_iterator(chroot);
file != std::filesystem::recursive_directory_iterator();
++file ) {
auto filePath = file->path().string();
if (filePath == devfsPath) {
file.disable_recursion_pending();
continue;
}
if (scannedFiles.find(filePath) != scannedFiles.end()) { continue; }
scannedFiles.insert(filePath);
auto candidates = scanForDependencies(filePath);
for (const auto& candidate : candidates) {
if (std::filesystem::exists(chroot + candidate)) { continue; }
if (!std::filesystem::exists(fallback + candidate)) { continue; }
std::filesystem::create_directories(std::filesystem::path(chroot + candidate).parent_path());
std::filesystem::copy(fallback + candidate, chroot + candidate);
add_symlinks_to_dylib(chroot + candidate);
foundNewEntries = true;
}
}
}
add_symlink("libSystem.B.dylib", chroot + "/usr/lib/libSystem.dylib");
add_symlink("libSystem.dylib", chroot + "/usr/lib/libc.dylib");
}
int main(int argc, const char * argv[]) {
std::vector<std::string> binaries;
std::vector<std::string> overlays;
std::string fallback;
std::string chroot;
for (int i = 1; i < argc; ++i) {
const char* arg = argv[i];
if (arg[0] == '-') {
if (strcmp(arg, "-chroot") == 0) {
chroot = argv[++i];
} else if (strcmp(arg, "-fallback") == 0) {
fallback = argv[++i];
} else if (strcmp(arg, "-add_file") == 0) {
binaries.push_back(argv[++i]);
} else {
fprintf(stderr, "unknown option: %s\n", arg);
exit(-1);
}
} else {
fprintf(stderr, "unknown option: %s\n", arg);
exit(-1);
}
}
if (chroot.length() == 0) {
fprintf(stderr, "No -chroot <dir>\n");
exit(-1);
}
if (fallback.length() == 0) {
fprintf(stderr, "No -fallback <dir>\n");
exit(-1);
}
buildChroot(chroot, fallback, binaries);
// insert code here...
return 0;
}