@@ -7,14 +7,41 @@ const elf = std.elf;
const windows = std.os.windows;
const system = std.os.system;
pub const DynLib = switch (builtin.os.tag) {
.linux => if (!builtin.link_libc or builtin.abi == .musl and builtin.link_mode == .static)
ElfDynLib
else
DlDynLib,
.windows => WindowsDynLib,
.macos, .tvos, .watchos, .ios, .freebsd, .netbsd, .openbsd, .dragonfly, .solaris, .illumos => DlDynLib,
else => void,
/// Cross-platform dynamic library loading and symbol lookup.
/// Platform-specific functionality is available through the `inner` field.
pub const DynLib = struct {
const InnerType = switch (builtin.os.tag) {
.linux => if (!builtin.link_libc or builtin.abi == .musl and builtin.link_mode == .static)
ElfDynLib
else
DlDynLib,
.windows => WindowsDynLib,
.macos, .tvos, .watchos, .ios, .freebsd, .netbsd, .openbsd, .dragonfly, .solaris, .illumos => DlDynLib,
else => @compileError("unsupported platform"),
};
inner: InnerType,
pub const Error = ElfDynLib.Error || DlDynLib.Error || WindowsDynLib.Error;
/// Trusts the file. Malicious file will be able to execute arbitrary code.
pub fn open(path: []const u8) Error!DynLib {
return .{ .inner = try InnerType.open(path) };
}
/// Trusts the file. Malicious file will be able to execute arbitrary code.
pub fn openZ(path_c: [*:0]const u8) Error!DynLib {
return .{ .inner = try InnerType.open(path_c) };
}
/// Trusts the file.
pub fn close(self: *DynLib) void {
return self.inner.close();
}
pub fn lookup(self: *DynLib, comptime T: type, name: [:0]const u8) ?T {
return self.inner.lookup(T, name);
}
};
// The link_map structure is not completely specified beside the fields
@@ -59,12 +86,12 @@ pub fn get_DYNAMIC() ?[*]elf.Dyn {
return @extern([*]elf.Dyn, .{ .name = "_DYNAMIC", .linkage = .weak });
}
pub fn linkmap_iterator(phdrs: []elf.Phdr) !LinkMap.Iterator {
pub fn linkmap_iterator(phdrs: []elf.Phdr) error{InvalidExe}!LinkMap.Iterator {
_ = phdrs;
const _DYNAMIC = get_DYNAMIC() orelse {
// No PT_DYNAMIC means this is either a statically-linked program or a
// badly corrupted dynamically-linked one.
return LinkMap.Iterator{ .current = null };
return .{ .current = null };
};
const link_map_ptr = init: {
@@ -89,10 +116,10 @@ pub fn linkmap_iterator(phdrs: []elf.Phdr) !LinkMap.Iterator {
else => {},
}
}
return LinkMap.Iterator{ .current = null };
return .{ .current = null };
};
return LinkMap.Iterator{ .current = link_map_ptr };
return .{ .current = link_map_ptr };
}
pub const ElfDynLib = struct {
@@ -111,10 +138,10 @@ pub const ElfDynLib = struct {
ElfStringSectionNotFound,
ElfSymSectionNotFound,
ElfHashTableNotFound,
};
} || os.OpenError || os.MMapError;
/// Trusts the file. Malicious file will be able to execute arbitrary code.
pub fn open(path: []const u8) !ElfDynLib {
pub fn open(path: []const u8) Error!ElfDynLib {
const fd = try os.open(path, .{ .ACCMODE = .RDONLY, .CLOEXEC = true }, 0);
defer os.close(fd);
@@ -239,7 +266,7 @@ pub const ElfDynLib = struct {
}
}
return ElfDynLib{
return .{
.memory = all_loaded_mem,
.strings = maybe_strings orelse return error.ElfStringSectionNotFound,
.syms = maybe_syms orelse return error.ElfSymSectionNotFound,
@@ -250,7 +277,7 @@ pub const ElfDynLib = struct {
}
/// Trusts the file. Malicious file will be able to execute arbitrary code.
pub fn openZ(path_c: [*:0]const u8) !ElfDynLib {
pub fn openZ(path_c: [*:0]const u8) Error!ElfDynLib {
return open(mem.sliceTo(path_c, 0));
}
@@ -260,7 +287,7 @@ pub const ElfDynLib = struct {
self.* = undefined;
}
pub fn lookup(self: *ElfDynLib, comptime T: type, name: [:0]const u8) ?T {
pub fn lookup(self: *const ElfDynLib, comptime T: type, name: [:0]const u8) ?T {
if (self.lookupAddress("", name)) |symbol| {
return @as(T, @ptrFromInt(symbol));
} else {
@@ -268,6 +295,7 @@ pub const ElfDynLib = struct {
}
}
/// ElfDynLib specific
/// Returns the address of the symbol
pub fn lookupAddress(self: *const ElfDynLib, vername: []const u8, name: []const u8) ?usize {
const maybe_versym = if (self.verdef == null) null else self.versym;
@@ -314,41 +342,59 @@ fn checkver(def_arg: *elf.Verdef, vsym_arg: i32, vername: []const u8, strings: [
return mem.eql(u8, vername, mem.sliceTo(strings + aux.vda_name, 0));
}
test "ElfDynLib" {
if (builtin.os.tag != .linux) {
return error.SkipZigTest;
}
try testing.expectError(error.FileNotFound, ElfDynLib.open("invalid_so.so"));
}
pub const WindowsDynLib = struct {
pub const Error = error{FileNotFound};
pub const Error = error{
FileNotFound,
InvalidPath,
} || windows.LoadLibraryError;
dll: windows.HMODULE,
pub fn open(path: []const u8) !WindowsDynLib {
pub fn open(path: []const u8) Error!WindowsDynLib {
return openEx(path, .none);
}
pub fn openEx(path: []const u8, flags: windows.LoadLibraryFlags) !WindowsDynLib {
const path_w = try windows.sliceToPrefixedFileW(null, path);
/// WindowsDynLib specific
/// Opens dynamic library with specified library loading flags.
pub fn openEx(path: []const u8, flags: windows.LoadLibraryFlags) Error!WindowsDynLib {
const path_w = windows.sliceToPrefixedFileW(null, path) catch return error.InvalidPath;
return openExW(path_w.span().ptr, flags);
}
pub fn openZ(path_c: [*:0]const u8) !WindowsDynLib {
pub fn openZ(path_c: [*:0]const u8) Error!WindowsDynLib {
return openExZ(path_c, .none);
}
pub fn openExZ(path_c: [*:0]const u8, flags: windows.LoadLibraryFlags) !WindowsDynLib {
/// WindowsDynLib specific
/// Opens dynamic library with specified library loading flags.
pub fn openExZ(path_c: [*:0]const u8, flags: windows.LoadLibraryFlags) Error!WindowsDynLib {
const path_w = try windows.cStrToPrefixedFileW(null, path_c);
return openExW(path_w.span().ptr, flags);
}
pub fn openW(path_w: [*:0]const u16) !WindowsDynLib {
/// WindowsDynLib specific
pub fn openW(path_w: [*:0]const u16) Error!WindowsDynLib {
return openExW(path_w, .none);
}
pub fn openExW(path_w: [*:0]const u16, flags: windows.LoadLibraryFlags) !WindowsDynLib {
/// WindowsDynLib specific
/// Opens dynamic library with specified library loading flags.
pub fn openExW(path_w: [*:0]const u16, flags: windows.LoadLibraryFlags) Error!WindowsDynLib {
var offset: usize = 0;
if (path_w[0] == '\\' and path_w[1] == '?' and path_w[2] == '?' and path_w[3] == '\\') {
// + 4 to skip over the \??\
offset = 4;
}
return WindowsDynLib{
return .{
.dll = try windows.LoadLibraryExW(path_w + offset, flags),
};
}
@@ -368,17 +414,17 @@ pub const WindowsDynLib = struct {
};
pub const DlDynLib = struct {
pub const Error = error{FileNotFound};
pub const Error = error{ FileNotFound, NameTooLong };
handle: *anyopaque,
pub fn open(path: []const u8) !DlDynLib {
pub fn open(path: []const u8) Error!DlDynLib {
const path_c = try os.toPosixPath(path);
return openZ(&path_c);
}
pub fn openZ(path_c: [*:0]const u8) !DlDynLib {
return DlDynLib{
pub fn openZ(path_c: [*:0]const u8) Error!DlDynLib {
return .{
.handle = system.dlopen(path_c, system.RTLD.LAZY) orelse {
return error.FileNotFound;
},
@@ -386,7 +432,10 @@ pub const DlDynLib = struct {
}
pub fn close(self: *DlDynLib) void {
_ = system.dlclose(self.handle);
switch (std.os.errno(system.dlclose(self.handle))) {
.SUCCESS => return,
else => unreachable,
}
self.* = undefined;
}
@@ -399,6 +448,13 @@ pub const DlDynLib = struct {
return null;
}
}
/// DlDynLib specific
/// Returns human readable string describing most recent error than occurred from `lookup`
/// or `null` if no error has occurred since initialization or when `getError` was last called.
pub fn getError() ?[:0]const u8 {
return mem.span(system.dlerror());
}
};
test "dynamic_library" {
@@ -409,8 +465,5 @@ test "dynamic_library" {
else => return error.SkipZigTest,
};
_ = DynLib.open(libname) catch |err| {
try testing.expect(err == error.FileNotFound);
return;
};
try testing.expectError(error.FileNotFound, DynLib.open(libname));
}