Remove squashfuse and fuse-overlayfs binaries

.gitmodules

@@ -13,3 +13,9 @@
 [submodule "zstd"]
 	path = zstd
 	url = https://github.com/facebook/zstd.git
+[submodule "squashfuse"]
+	path = squashfuse
+	url = https://github.com/vasi/squashfuse.git
+[submodule "fuse-overlayfs"]
+	path = fuse-overlayfs
+	url = https://github.com/containers/fuse-overlayfs.git

build.zig

@@ -17,6 +17,140 @@ pub fn build(b: *std.Build) void {
     // set a preferred release mode, allowing the user to decide how to optimize.
     const optimize = b.standardOptimizeOption(.{});
 
+    const zstd = b.addStaticLibrary(.{
+        .name = "zstd",
+        .target = target,
+        .optimize = optimize,
+        .link_libc = true,
+    });
+    zstd.addAssemblyFile(b.path("zstd/lib/decompress/huf_decompress_amd64.S"));
+    zstd.addCSourceFiles(.{
+        .files = &[_][]const u8{
+            "zstd/lib/common/debug.c",
+            "zstd/lib/common/entropy_common.c",
+            "zstd/lib/common/error_private.c",
+            "zstd/lib/common/fse_decompress.c",
+            "zstd/lib/common/pool.c",
+            "zstd/lib/common/threading.c",
+            "zstd/lib/common/xxhash.c",
+            "zstd/lib/common/zstd_common.c",
+
+            "zstd/lib/compress/fse_compress.c",
+            "zstd/lib/compress/hist.c",
+            "zstd/lib/compress/huf_compress.c",
+            "zstd/lib/compress/zstd_compress.c",
+            "zstd/lib/compress/zstd_compress_literals.c",
+            "zstd/lib/compress/zstd_compress_sequences.c",
+            "zstd/lib/compress/zstd_compress_superblock.c",
+            "zstd/lib/compress/zstd_double_fast.c",
+            "zstd/lib/compress/zstd_fast.c",
+            "zstd/lib/compress/zstd_lazy.c",
+            "zstd/lib/compress/zstd_ldm.c",
+            "zstd/lib/compress/zstdmt_compress.c",
+            "zstd/lib/compress/zstd_opt.c",
+
+            "zstd/lib/decompress/huf_decompress.c",
+            "zstd/lib/decompress/zstd_ddict.c",
+            "zstd/lib/decompress/zstd_decompress_block.c",
+            "zstd/lib/decompress/zstd_decompress.c",
+        },
+    });
+
+    const squashfuse_autogen = b.addSystemCommand(&[_][]const u8{
+        "./autogen.sh",
+    });
+    squashfuse_autogen.setCwd(b.path("squashfuse"));
+
+    const squashfuse_configure = b.addSystemCommand(&[_][]const u8{
+        "./configure",
+        "--without-zlib",
+        "--without-xz",
+        "--without-lzo",
+        "--without-lz4",
+        "--with-zstd",
+    });
+    squashfuse_configure.setCwd(b.path("squashfuse"));
+    squashfuse_configure.step.dependOn(&squashfuse_autogen.step);
+
+    const squashfuse_make_generate_swap = b.addSystemCommand(&[_][]const u8{
+        "make",
+        "swap.h.inc",
+        "swap.c.inc",
+    });
+    squashfuse_make_generate_swap.setCwd(b.path("squashfuse"));
+    squashfuse_make_generate_swap.step.dependOn(&squashfuse_configure.step);
+
+    const overlayfs_autogen = b.addSystemCommand(&[_][]const u8{
+        "./autogen.sh",
+    });
+    overlayfs_autogen.setCwd(b.path("fuse-overlayfs"));
+
+    const overlayfs_configure = b.addSystemCommand(&[_][]const u8{
+        "./configure",
+    });
+    overlayfs_configure.setCwd(b.path("fuse-overlayfs"));
+    overlayfs_configure.step.dependOn(&overlayfs_autogen.step);
+
+    const fuse_fss = b.addStaticLibrary(.{
+        .name = "fuse-overlayfs",
+        .target = target,
+        .optimize = optimize,
+        .link_libc = true,
+    });
+    fuse_fss.addIncludePath(b.path("zstd/lib"));
+
+    fuse_fss.linkSystemLibrary("fuse3");
+    fuse_fss.addIncludePath(b.path("fuse-overlayfs"));
+    fuse_fss.addIncludePath(b.path("fuse-overlayfs/lib"));
+    fuse_fss.addCSourceFiles(.{
+        .files = &[_][]const u8{
+            "fuse-overlayfs/main.c",
+            "fuse-overlayfs/lib/hash.c",
+            "fuse-overlayfs/lib/bitrotate.c",
+            "fuse-overlayfs/utils.c",
+            "fuse-overlayfs/plugin-manager.c",
+            "fuse-overlayfs/direct.c",
+        },
+        .flags = &[_][]const u8{
+            "-Dmain=overlayfs_main",
+            // collision with libcrun
+            "-Dsafe_openat=overlayfs_safe_openat",
+            "-DPKGLIBEXECDIR=\"\"",
+            "-Wno-format",
+            "-Wno-switch",
+        },
+    });
+    fuse_fss.addCSourceFiles(.{
+        .files = &[_][]const u8{
+            "squashfuse/ll_main.c",
+            "squashfuse/ll.c",
+            "squashfuse/ll_inode.c",
+            "squashfuse/fs.c",
+            "squashfuse/fuseprivate.c",
+            "squashfuse/stat.c",
+            "squashfuse/dir.c",
+            "squashfuse/file.c",
+            "squashfuse/xattr.c",
+            "squashfuse/nonstd-enoattr.c",
+            "squashfuse/nonstd-makedev.c",
+            "squashfuse/util.c",
+            "squashfuse/nonstd-daemon.c",
+            "squashfuse/nonstd-pread.c",
+            "squashfuse/swap.c",
+            "squashfuse/table.c",
+            "squashfuse/cache_mt.c",
+            "squashfuse/decompress.c",
+            "squashfuse/nonstd-stat.c",
+        },
+        .flags = &[_][]const u8{
+            "-Dmain=squashfuse_main",
+            "-D_FILE_OFFSET_BITS=64",
+        },
+    });
+
+    fuse_fss.step.dependOn(&squashfuse_make_generate_swap.step);
+    fuse_fss.step.dependOn(&overlayfs_configure.step);
+
     const clap = b.dependency("clap", .{
         .optimize = optimize,
         .target = target,
@@ -30,6 +164,9 @@ pub fn build(b: *std.Build) void {
         .link_libc = true,
     });
 
+    runtime.linkLibrary(zstd);
+    runtime.linkLibrary(fuse_fss);
+
     runtime.addIncludePath(b.path("crun"));
     runtime.addIncludePath(b.path("crun/src"));
     runtime.addIncludePath(b.path("crun/libocispec/src"));
@@ -115,36 +252,9 @@ pub fn build(b: *std.Build) void {
     });
 
     dockerc.addIncludePath(b.path("zstd/lib"));
+    dockerc.linkLibrary(zstd);
     dockerc.addCSourceFiles(.{
         .files = &[_][]const u8{
-            "zstd/lib/common/debug.c",
-            "zstd/lib/common/entropy_common.c",
-            "zstd/lib/common/error_private.c",
-            "zstd/lib/common/fse_decompress.c",
-            "zstd/lib/common/pool.c",
-            "zstd/lib/common/threading.c",
-            "zstd/lib/common/xxhash.c",
-            "zstd/lib/common/zstd_common.c",
-
-            "zstd/lib/compress/fse_compress.c",
-            "zstd/lib/compress/hist.c",
-            "zstd/lib/compress/huf_compress.c",
-            "zstd/lib/compress/zstd_compress.c",
-            "zstd/lib/compress/zstd_compress_literals.c",
-            "zstd/lib/compress/zstd_compress_sequences.c",
-            "zstd/lib/compress/zstd_compress_superblock.c",
-            "zstd/lib/compress/zstd_double_fast.c",
-            "zstd/lib/compress/zstd_fast.c",
-            "zstd/lib/compress/zstd_lazy.c",
-            "zstd/lib/compress/zstd_ldm.c",
-            "zstd/lib/compress/zstdmt_compress.c",
-            "zstd/lib/compress/zstd_opt.c",
-
-            "zstd/lib/decompress/huf_decompress.c",
-            "zstd/lib/decompress/zstd_ddict.c",
-            "zstd/lib/decompress/zstd_decompress_block.c",
-            "zstd/lib/decompress/zstd_decompress.c",
-
             "squashfs-tools/squashfs-tools/mksquashfs.c",
             "squashfs-tools/squashfs-tools/progressbar.c",
             "squashfs-tools/squashfs-tools/caches-queues-lists.c",
@@ -167,9 +277,6 @@ pub fn build(b: *std.Build) void {
         .flags = &[_][]const u8{
             // avoid collision of main function
             "-Dmain=mksquashfs_main",
-            // zstd: asm is only used for decompression so it is fine to disable
-            "-DZSTD_DISABLE_ASM",
-            // squashfs defines
             "-DZSTD_SUPPORT",
             "-D_GNU_SOURCE",
             "-DVERSION=\"dockerc\"",

src/main.zig

@@ -5,14 +5,14 @@ const common = @import("common.zig");
 const mkdtemp = common.mkdtemp;
 const extract_file = common.extract_file;
 
-const squashfuse_content = @embedFile("tools/squashfuse");
-const overlayfs_content = @embedFile("tools/fuse-overlayfs");
-
 const c = @cImport({
     @cInclude("libcrun/container.h");
     @cInclude("libcrun/custom-handler.h");
 });
 
+extern fn squashfuse_main(argc: c_int, argv: [*:null]const ?[*:0]const u8) c_int;
+extern fn overlayfs_main(argc: c_int, argv: [*:null]const ?[*:0]const u8) c_int;
+
 fn getOffset(path: []const u8) !u64 {
     var file = try std.fs.cwd().openFile(path, .{});
     try file.seekFromEnd(-8);
@@ -174,12 +174,6 @@ pub fn main() !void {
     var temp_dir_path = "/tmp/dockerc-XXXXXX".*;
     try mkdtemp(&temp_dir_path);
 
-    const squashfuse_path = try extract_file(&temp_dir_path, "squashfuse", squashfuse_content, allocator);
-    defer allocator.free(squashfuse_path);
-
-    const overlayfs_path = try extract_file(&temp_dir_path, "fuse-overlayfs", overlayfs_content, allocator);
-    defer allocator.free(overlayfs_path);
-
     const filesystem_bundle_dir_null = try std.fmt.allocPrintZ(allocator, "{s}/{s}", .{ temp_dir_path, "bundle.squashfs" });
     defer allocator.free(filesystem_bundle_dir_null);
 
@@ -188,15 +182,25 @@ pub fn main() !void {
     const mount_dir_path = try std.fmt.allocPrintZ(allocator, "{s}/mount", .{temp_dir_path});
     defer allocator.free(mount_dir_path);
 
-    const offsetArg = try std.fmt.allocPrint(allocator, "offset={}", .{try getOffset(executable_path)});
+    const offsetArg = try std.fmt.allocPrintZ(allocator, "offset={}", .{try getOffset(executable_path)});
     defer allocator.free(offsetArg);
 
-    const args_buf = [_][]const u8{ squashfuse_path, "-o", offsetArg, executable_path, filesystem_bundle_dir_null };
+    const args_buf = [_:null]?[*:0]const u8{ "squashfuse", "-o", offsetArg, executable_path, filesystem_bundle_dir_null };
 
-    var mountProcess = std.process.Child.init(&args_buf, allocator);
-    _ = try mountProcess.spawnAndWait();
+    {
+        const pid = try std.posix.fork();
+        if (pid == 0) {
+            std.process.exit(@intCast(squashfuse_main(args_buf.len, &args_buf)));
+        }
 
-    const overlayfs_options = try std.fmt.allocPrint(allocator, "lowerdir={s},upperdir={s}/upper,workdir={s}/work", .{
+        const wait_pid_result = std.posix.waitpid(pid, 0);
+        if (wait_pid_result.status != 0) {
+            // TODO: extract instead of failing
+            std.debug.panic("failed to run squashfuse", .{});
+        }
+    }
+
+    const overlayfs_options = try std.fmt.allocPrintZ(allocator, "lowerdir={s},upperdir={s}/upper,workdir={s}/work", .{
         filesystem_bundle_dir_null,
         temp_dir_path,
         temp_dir_path,
@@ -212,8 +216,17 @@ pub fn main() !void {
         try tmpDir.makeDir("work");
         try tmpDir.makeDir("mount");
 
-        var overlayfsProcess = std.process.Child.init(&[_][]const u8{ overlayfs_path, "-o", overlayfs_options, mount_dir_path }, allocator);
-        _ = try overlayfsProcess.spawnAndWait();
+        const overlayfs_args = [_:null]?[*:0]const u8{ "fuse-overlayfs", "-o", overlayfs_options, mount_dir_path };
+
+        const pid = try std.posix.fork();
+        if (pid == 0) {
+            std.process.exit(@intCast(overlayfs_main(overlayfs_args.len, &overlayfs_args)));
+        }
+
+        const wait_pid_result = std.posix.waitpid(pid, 0);
+        if (wait_pid_result.status != 0) {
+            std.debug.panic("failed to run overlayfs", .{});
+        }
 
         const rootfs_absolute_path = try std.fmt.allocPrint(allocator, "{s}/mount/rootfs", .{temp_dir_path});
         defer allocator.free(rootfs_absolute_path);