]> git.ipfire.org Git - thirdparty/wireguard-go.git/commitdiff
wintun: load wintun.dll from RCDATA resource
authorSimon Rozman <simon@rozman.si>
Fri, 6 Nov 2020 04:24:50 +0000 (05:24 +0100)
committerJason A. Donenfeld <Jason@zx2c4.com>
Sat, 7 Nov 2020 14:20:49 +0000 (15:20 +0100)
Signed-off-by: Simon Rozman <simon@rozman.si>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
19 files changed:
go.mod
go.sum
tun/wintun/dll_windows.go [new file with mode: 0644]
tun/wintun/memmod/memmod_windows.go [new file with mode: 0644]
tun/wintun/memmod/memmod_windows_32.go [new file with mode: 0644]
tun/wintun/memmod/memmod_windows_386.go [new file with mode: 0644]
tun/wintun/memmod/memmod_windows_64.go [new file with mode: 0644]
tun/wintun/memmod/memmod_windows_amd64.go [new file with mode: 0644]
tun/wintun/memmod/memmod_windows_arm.go [new file with mode: 0644]
tun/wintun/memmod/memmod_windows_arm64.go [new file with mode: 0644]
tun/wintun/memmod/mksyscall.go [new file with mode: 0644]
tun/wintun/memmod/syscall_windows.go [new file with mode: 0644]
tun/wintun/memmod/syscall_windows_32.go [new file with mode: 0644]
tun/wintun/memmod/syscall_windows_64.go [new file with mode: 0644]
tun/wintun/memmod/zsyscall_windows.go [new file with mode: 0644]
tun/wintun/resource/mksyscall.go [new file with mode: 0644]
tun/wintun/resource/resource_windows.go [new file with mode: 0644]
tun/wintun/resource/zsyscall_windows.go [new file with mode: 0644]
tun/wintun/wintun_windows.go

diff --git a/go.mod b/go.mod
index 12f27f7710c4d07c5d55950ad8dc78f8e0911def..1d98c6d1192339139c1e18e8247781034b38789f 100644 (file)
--- a/go.mod
+++ b/go.mod
@@ -5,6 +5,6 @@ go 1.13
 require (
        golang.org/x/crypto v0.0.0-20200429183012-4b2356b1ed79
        golang.org/x/net v0.0.0-20200501053045-e0ff5e5a1de5
-       golang.org/x/sys v0.0.0-20201027130517-9d1ec526b7bf
+       golang.org/x/sys v0.0.0-20201107080550-4d91cf3a1aaf
        golang.org/x/text v0.3.2
 )
diff --git a/go.sum b/go.sum
index d7777d80cc71f89a04d4f8402a5f4c25f65fba2d..bce33450b7136ae2135451667bc169e0526c25ef 100644 (file)
--- a/go.sum
+++ b/go.sum
@@ -9,6 +9,8 @@ golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201027130517-9d1ec526b7bf h1:HmHgHRpqpvB74D7bjXkue6kkHJfOrKyYJtW6Sv4jpI4=
 golang.org/x/sys v0.0.0-20201027130517-9d1ec526b7bf/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201107080550-4d91cf3a1aaf h1:kt3wY1Lu5MJAnKTfoMR52Cu4gwvna4VTzNOiT8tY73s=
+golang.org/x/sys v0.0.0-20201107080550-4d91cf3a1aaf/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
diff --git a/tun/wintun/dll_windows.go b/tun/wintun/dll_windows.go
new file mode 100644 (file)
index 0000000..af1e016
--- /dev/null
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package wintun
+
+import (
+       "fmt"
+       "sync"
+       "sync/atomic"
+       "unsafe"
+
+       "golang.org/x/sys/windows"
+       "golang.zx2c4.com/wireguard/tun/wintun/memmod"
+       "golang.zx2c4.com/wireguard/tun/wintun/resource"
+)
+
+type lazyDLL struct {
+       Name   string
+       mu     sync.Mutex
+       module *memmod.Module
+}
+
+func newLazyDLL(name string) *lazyDLL {
+       return &lazyDLL{Name: name}
+}
+
+func (d *lazyDLL) Load() error {
+       if atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&d.module))) != nil {
+               return nil
+       }
+       d.mu.Lock()
+       defer d.mu.Unlock()
+       if d.module != nil {
+               return nil
+       }
+
+       const ourModule windows.Handle = 0
+       resInfo, err := resource.FindByName(ourModule, d.Name, resource.RT_RCDATA)
+       if err != nil {
+               return fmt.Errorf("Unable to find \"%v\" RCDATA resource: %v", d.Name, err)
+       }
+       data, err := resource.Load(ourModule, resInfo)
+       if err != nil {
+               return fmt.Errorf("Unable to load resource: %v", err)
+       }
+       module, err := memmod.LoadLibrary(data)
+       if err != nil {
+               return fmt.Errorf("Unable to load library: %v", err)
+       }
+
+       atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&d.module)), unsafe.Pointer(module))
+       return nil
+}
+
+func (d *lazyDLL) NewProc(name string) *lazyProc {
+       return &lazyProc{dll: d, Name: name}
+}
+
+type lazyProc struct {
+       Name string
+       mu   sync.Mutex
+       dll  *lazyDLL
+       addr uintptr
+}
+
+func (p *lazyProc) Find() error {
+       if atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&p.addr))) != nil {
+               return nil
+       }
+       p.mu.Lock()
+       defer p.mu.Unlock()
+       if p.addr != 0 {
+               return nil
+       }
+
+       err := p.dll.Load()
+       if err != nil {
+               return fmt.Errorf("Error loading %v DLL: %v", p.dll.Name, err)
+       }
+       addr, err := p.dll.module.ProcAddressByName(p.Name)
+       if err != nil {
+               return fmt.Errorf("Error getting %v address: %v", p.Name, err)
+       }
+
+       atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&p.addr)), unsafe.Pointer(addr))
+       return nil
+}
+
+func (p *lazyProc) Addr() uintptr {
+       err := p.Find()
+       if err != nil {
+               panic(err)
+       }
+       return p.addr
+}
diff --git a/tun/wintun/memmod/memmod_windows.go b/tun/wintun/memmod/memmod_windows.go
new file mode 100644 (file)
index 0000000..a168c4d
--- /dev/null
@@ -0,0 +1,620 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+import (
+       "errors"
+       "fmt"
+       "syscall"
+       "unsafe"
+
+       "golang.org/x/sys/windows"
+)
+
+type addressList struct {
+       next    *addressList
+       address uintptr
+}
+
+func (head *addressList) free() {
+       for node := head; node != nil; node = node.next {
+               windows.VirtualFree(node.address, 0, windows.MEM_RELEASE)
+       }
+}
+
+type Module struct {
+       headers       *IMAGE_NT_HEADERS
+       codeBase      uintptr
+       modules       []windows.Handle
+       initialized   bool
+       isDLL         bool
+       isRelocated   bool
+       nameExports   map[string]uint16
+       entry         uintptr
+       blockedMemory *addressList
+}
+
+func (module *Module) headerDirectory(idx int) *IMAGE_DATA_DIRECTORY {
+       return &module.headers.OptionalHeader.DataDirectory[idx]
+}
+
+func (module *Module) copySections(address uintptr, size uintptr, old_headers *IMAGE_NT_HEADERS) error {
+       sections := module.headers.Sections()
+       for i := range sections {
+               if sections[i].SizeOfRawData == 0 {
+                       // Section doesn't contain data in the dll itself, but may define uninitialized data.
+                       sectionSize := old_headers.OptionalHeader.SectionAlignment
+                       if sectionSize == 0 {
+                               continue
+                       }
+                       dest, err := windows.VirtualAlloc(module.codeBase+uintptr(sections[i].VirtualAddress),
+                               uintptr(sectionSize),
+                               windows.MEM_COMMIT,
+                               windows.PAGE_READWRITE)
+                       if err != nil {
+                               return fmt.Errorf("Error allocating section: %v", err)
+                       }
+
+                       // Always use position from file to support alignments smaller than page size (allocation above will align to page size).
+                       dest = module.codeBase + uintptr(sections[i].VirtualAddress)
+                       // NOTE: On 64bit systems we truncate to 32bit here but expand again later when "PhysicalAddress" is used.
+                       sections[i].SetPhysicalAddress((uint32)(dest & 0xffffffff))
+                       var dst []byte
+                       unsafeSlice(unsafe.Pointer(&dst), a2p(dest), int(sectionSize))
+                       for j := range dst {
+                               dst[j] = 0
+                       }
+                       continue
+               }
+
+               if size < uintptr(sections[i].PointerToRawData+sections[i].SizeOfRawData) {
+                       return errors.New("Incomplete section")
+               }
+
+               // Commit memory block and copy data from dll.
+               dest, err := windows.VirtualAlloc(module.codeBase+uintptr(sections[i].VirtualAddress),
+                       uintptr(sections[i].SizeOfRawData),
+                       windows.MEM_COMMIT,
+                       windows.PAGE_READWRITE)
+               if err != nil {
+                       return fmt.Errorf("Error allocating memory block: %v", err)
+               }
+
+               // Always use position from file to support alignments smaller than page size (allocation above will align to page size).
+               memcpy(
+                       module.codeBase+uintptr(sections[i].VirtualAddress),
+                       address+uintptr(sections[i].PointerToRawData),
+                       uintptr(sections[i].SizeOfRawData))
+               // NOTE: On 64bit systems we truncate to 32bit here but expand again later when "PhysicalAddress" is used.
+               sections[i].SetPhysicalAddress((uint32)(dest & 0xffffffff))
+       }
+
+       return nil
+}
+
+func (module *Module) realSectionSize(section *IMAGE_SECTION_HEADER) uintptr {
+       size := section.SizeOfRawData
+       if size != 0 {
+               return uintptr(size)
+       }
+       if (section.Characteristics & IMAGE_SCN_CNT_INITIALIZED_DATA) != 0 {
+               return uintptr(module.headers.OptionalHeader.SizeOfInitializedData)
+       }
+       if (section.Characteristics & IMAGE_SCN_CNT_UNINITIALIZED_DATA) != 0 {
+               return uintptr(module.headers.OptionalHeader.SizeOfUninitializedData)
+       }
+       return 0
+}
+
+type sectionFinalizeData struct {
+       address         uintptr
+       alignedAddress  uintptr
+       size            uintptr
+       characteristics uint32
+       last            bool
+}
+
+func (module *Module) finalizeSection(sectionData *sectionFinalizeData) error {
+       if sectionData.size == 0 {
+               return nil
+       }
+
+       if (sectionData.characteristics & IMAGE_SCN_MEM_DISCARDABLE) != 0 {
+               // Section is not needed any more and can safely be freed.
+               if sectionData.address == sectionData.alignedAddress &&
+                       (sectionData.last ||
+                               (sectionData.size%uintptr(module.headers.OptionalHeader.SectionAlignment)) == 0) {
+                       // Only allowed to decommit whole pages.
+                       windows.VirtualFree(sectionData.address, sectionData.size, windows.MEM_DECOMMIT)
+               }
+               return nil
+       }
+
+       // determine protection flags based on characteristics
+       var ProtectionFlags = [8]uint32{
+               windows.PAGE_NOACCESS,          // not writeable, not readable, not executable
+               windows.PAGE_EXECUTE,           // not writeable, not readable, executable
+               windows.PAGE_READONLY,          // not writeable, readable, not executable
+               windows.PAGE_EXECUTE_READ,      // not writeable, readable, executable
+               windows.PAGE_WRITECOPY,         // writeable, not readable, not executable
+               windows.PAGE_EXECUTE_WRITECOPY, // writeable, not readable, executable
+               windows.PAGE_READWRITE,         // writeable, readable, not executable
+               windows.PAGE_EXECUTE_READWRITE, // writeable, readable, executable
+       }
+       protect := ProtectionFlags[sectionData.characteristics>>29]
+       if (sectionData.characteristics & IMAGE_SCN_MEM_NOT_CACHED) != 0 {
+               protect |= windows.PAGE_NOCACHE
+       }
+
+       // Change memory access flags.
+       var oldProtect uint32
+       err := windows.VirtualProtect(sectionData.address, sectionData.size, protect, &oldProtect)
+       if err != nil {
+               return fmt.Errorf("Error protecting memory page: %v", err)
+       }
+
+       return nil
+}
+
+func (module *Module) finalizeSections() error {
+       sections := module.headers.Sections()
+       imageOffset := module.headers.OptionalHeader.imageOffset()
+       sectionData := sectionFinalizeData{}
+       sectionData.address = uintptr(sections[0].PhysicalAddress()) | imageOffset
+       sectionData.alignedAddress = alignDown(sectionData.address, uintptr(module.headers.OptionalHeader.SectionAlignment))
+       sectionData.size = module.realSectionSize(&sections[0])
+       sectionData.characteristics = sections[0].Characteristics
+
+       // Loop through all sections and change access flags.
+       for i := uint16(1); i < module.headers.FileHeader.NumberOfSections; i++ {
+               sectionAddress := uintptr(sections[i].PhysicalAddress()) | imageOffset
+               alignedAddress := alignDown(sectionAddress, uintptr(module.headers.OptionalHeader.SectionAlignment))
+               sectionSize := module.realSectionSize(&sections[i])
+               // Combine access flags of all sections that share a page.
+               // TODO: We currently share flags of a trailing large section with the page of a first small section. This should be optimized.
+               if sectionData.alignedAddress == alignedAddress || sectionData.address+sectionData.size > alignedAddress {
+                       // Section shares page with previous.
+                       if (sections[i].Characteristics&IMAGE_SCN_MEM_DISCARDABLE) == 0 || (sectionData.characteristics&IMAGE_SCN_MEM_DISCARDABLE) == 0 {
+                               sectionData.characteristics = (sectionData.characteristics | sections[i].Characteristics) &^ IMAGE_SCN_MEM_DISCARDABLE
+                       } else {
+                               sectionData.characteristics |= sections[i].Characteristics
+                       }
+                       sectionData.size = sectionAddress + sectionSize - sectionData.address
+                       continue
+               }
+
+               err := module.finalizeSection(&sectionData)
+               if err != nil {
+                       return fmt.Errorf("Error finalizing section: %v", err)
+               }
+               sectionData.address = sectionAddress
+               sectionData.alignedAddress = alignedAddress
+               sectionData.size = sectionSize
+               sectionData.characteristics = sections[i].Characteristics
+       }
+       sectionData.last = true
+       err := module.finalizeSection(&sectionData)
+       if err != nil {
+               return fmt.Errorf("Error finalizing section: %v", err)
+       }
+       return nil
+}
+
+func (module *Module) executeTLS() {
+       directory := module.headerDirectory(IMAGE_DIRECTORY_ENTRY_TLS)
+       if directory.VirtualAddress == 0 {
+               return
+       }
+
+       tls := (*IMAGE_TLS_DIRECTORY)(a2p(module.codeBase + uintptr(directory.VirtualAddress)))
+       callback := tls.AddressOfCallbacks
+       if callback != 0 {
+               for {
+                       f := *(*uintptr)(a2p(callback))
+                       if f == 0 {
+                               break
+                       }
+                       syscall.Syscall(f, 3, module.codeBase, uintptr(DLL_PROCESS_ATTACH), uintptr(0))
+                       callback += unsafe.Sizeof(f)
+               }
+       }
+}
+
+func (module *Module) performBaseRelocation(delta uintptr) (relocated bool, err error) {
+       directory := module.headerDirectory(IMAGE_DIRECTORY_ENTRY_BASERELOC)
+       if directory.Size == 0 {
+               return delta == 0, nil
+       }
+
+       relocationHdr := (*IMAGE_BASE_RELOCATION)(a2p(module.codeBase + uintptr(directory.VirtualAddress)))
+       for relocationHdr.VirtualAddress > 0 {
+               dest := module.codeBase + uintptr(relocationHdr.VirtualAddress)
+
+               var relInfos []uint16
+               unsafeSlice(
+                       unsafe.Pointer(&relInfos),
+                       a2p(uintptr(unsafe.Pointer(relocationHdr))+unsafe.Sizeof(*relocationHdr)),
+                       int((uintptr(relocationHdr.SizeOfBlock)-unsafe.Sizeof(*relocationHdr))/unsafe.Sizeof(relInfos[0])))
+               for _, relInfo := range relInfos {
+                       // The upper 4 bits define the type of relocation.
+                       relType := relInfo >> 12
+                       // The lower 12 bits define the offset.
+                       relOffset := uintptr(relInfo & 0xfff)
+
+                       switch relType {
+                       case IMAGE_REL_BASED_ABSOLUTE:
+                               // Skip relocation.
+
+                       case IMAGE_REL_BASED_LOW:
+                               *(*uint16)(a2p(dest + relOffset)) += uint16(delta & 0xffff)
+                               break
+
+                       case IMAGE_REL_BASED_HIGH:
+                               *(*uint16)(a2p(dest + relOffset)) += uint16(uint32(delta) >> 16)
+                               break
+
+                       case IMAGE_REL_BASED_HIGHLOW:
+                               *(*uint32)(a2p(dest + relOffset)) += uint32(delta)
+
+                       case IMAGE_REL_BASED_DIR64:
+                               *(*uint64)(a2p(dest + relOffset)) += uint64(delta)
+
+                       case IMAGE_REL_BASED_THUMB_MOV32:
+                               inst := *(*uint32)(a2p(dest + relOffset))
+                               imm16 := ((inst << 1) & 0x0800) + ((inst << 12) & 0xf000) +
+                                       ((inst >> 20) & 0x0700) + ((inst >> 16) & 0x00ff)
+                               if (inst & 0x8000fbf0) != 0x0000f240 {
+                                       return false, fmt.Errorf("Wrong Thumb2 instruction %08x, expected MOVW", inst)
+                               }
+                               imm16 += uint32(delta) & 0xffff
+                               hiDelta := (uint32(delta&0xffff0000) >> 16) + ((imm16 & 0xffff0000) >> 16)
+                               *(*uint32)(a2p(dest + relOffset)) = (inst & 0x8f00fbf0) + ((imm16 >> 1) & 0x0400) +
+                                       ((imm16 >> 12) & 0x000f) +
+                                       ((imm16 << 20) & 0x70000000) +
+                                       ((imm16 << 16) & 0xff0000)
+                               if hiDelta != 0 {
+                                       inst = *(*uint32)(a2p(dest + relOffset + 4))
+                                       imm16 = ((inst << 1) & 0x0800) + ((inst << 12) & 0xf000) +
+                                               ((inst >> 20) & 0x0700) + ((inst >> 16) & 0x00ff)
+                                       if (inst & 0x8000fbf0) != 0x0000f2c0 {
+                                               return false, fmt.Errorf("Wrong Thumb2 instruction %08x, expected MOVT", inst)
+                                       }
+                                       imm16 += hiDelta
+                                       if imm16 > 0xffff {
+                                               return false, fmt.Errorf("Resulting immediate value won't fit: %08x", imm16)
+                                       }
+                                       *(*uint32)(a2p(dest + relOffset + 4)) = (inst & 0x8f00fbf0) +
+                                               ((imm16 >> 1) & 0x0400) +
+                                               ((imm16 >> 12) & 0x000f) +
+                                               ((imm16 << 20) & 0x70000000) +
+                                               ((imm16 << 16) & 0xff0000)
+                               }
+
+                       default:
+                               return false, fmt.Errorf("Unsupported relocation: %v", relType)
+                       }
+               }
+
+               // Advance to next relocation block.
+               relocationHdr = (*IMAGE_BASE_RELOCATION)(a2p(uintptr(unsafe.Pointer(relocationHdr)) + uintptr(relocationHdr.SizeOfBlock)))
+       }
+       return true, nil
+}
+
+func (module *Module) buildImportTable() error {
+       directory := module.headerDirectory(IMAGE_DIRECTORY_ENTRY_IMPORT)
+       if directory.Size == 0 {
+               return nil
+       }
+
+       module.modules = make([]windows.Handle, 0, 16)
+       importDesc := (*IMAGE_IMPORT_DESCRIPTOR)(a2p(module.codeBase + uintptr(directory.VirtualAddress)))
+       for !isBadReadPtr(uintptr(unsafe.Pointer(importDesc)), unsafe.Sizeof(*importDesc)) && importDesc.Name != 0 {
+               handle, err := loadLibraryA((*byte)(a2p(module.codeBase + uintptr(importDesc.Name))))
+               if err != nil {
+                       return fmt.Errorf("Error loading module: %v", err)
+               }
+               var thunkRef, funcRef *uintptr
+               if importDesc.OriginalFirstThunk() != 0 {
+                       thunkRef = (*uintptr)(a2p(module.codeBase + uintptr(importDesc.OriginalFirstThunk())))
+                       funcRef = (*uintptr)(a2p(module.codeBase + uintptr(importDesc.FirstThunk)))
+               } else {
+                       // No hint table.
+                       thunkRef = (*uintptr)(a2p(module.codeBase + uintptr(importDesc.FirstThunk)))
+                       funcRef = (*uintptr)(a2p(module.codeBase + uintptr(importDesc.FirstThunk)))
+               }
+               for *thunkRef != 0 {
+                       if IMAGE_SNAP_BY_ORDINAL(*thunkRef) {
+                               *funcRef, err = getProcAddress(handle, (*byte)(a2p(IMAGE_ORDINAL(*thunkRef))))
+                       } else {
+                               thunkData := (*IMAGE_IMPORT_BY_NAME)(a2p(module.codeBase + *thunkRef))
+                               *funcRef, err = getProcAddress(handle, &thunkData.Name[0])
+                       }
+                       if err != nil {
+                               windows.FreeLibrary(handle)
+                               return fmt.Errorf("Error getting function address: %v", err)
+                       }
+                       thunkRef = (*uintptr)(a2p(uintptr(unsafe.Pointer(thunkRef)) + unsafe.Sizeof(*thunkRef)))
+                       funcRef = (*uintptr)(a2p(uintptr(unsafe.Pointer(funcRef)) + unsafe.Sizeof(*funcRef)))
+               }
+               module.modules = append(module.modules, handle)
+               importDesc = (*IMAGE_IMPORT_DESCRIPTOR)(a2p(uintptr(unsafe.Pointer(importDesc)) + unsafe.Sizeof(*importDesc)))
+       }
+       return nil
+}
+
+func (module *Module) buildNameExports() error {
+       directory := module.headerDirectory(IMAGE_DIRECTORY_ENTRY_EXPORT)
+       if directory.Size == 0 {
+               return errors.New("No export table found")
+       }
+       exports := (*IMAGE_EXPORT_DIRECTORY)(a2p(module.codeBase + uintptr(directory.VirtualAddress)))
+       if exports.NumberOfNames == 0 || exports.NumberOfFunctions == 0 {
+               return errors.New("No functions exported")
+       }
+       if exports.NumberOfNames == 0 {
+               return errors.New("No functions exported by name")
+       }
+       var nameRefs []uint32
+       unsafeSlice(unsafe.Pointer(&nameRefs), a2p(module.codeBase+uintptr(exports.AddressOfNames)), int(exports.NumberOfNames))
+       var ordinals []uint16
+       unsafeSlice(unsafe.Pointer(&ordinals), a2p(module.codeBase+uintptr(exports.AddressOfNameOrdinals)), int(exports.NumberOfNames))
+       module.nameExports = make(map[string]uint16)
+       for i := range nameRefs {
+               nameArray := windows.BytePtrToString((*byte)(a2p(module.codeBase + uintptr(nameRefs[i]))))
+               module.nameExports[nameArray] = ordinals[i]
+       }
+       return nil
+}
+
+// LoadLibrary loads module image to memory.
+func LoadLibrary(data []byte) (module *Module, err error) {
+       addr := uintptr(unsafe.Pointer(&data[0]))
+       size := uintptr(len(data))
+       if size < unsafe.Sizeof(IMAGE_DOS_HEADER{}) {
+               return nil, errors.New("Incomplete IMAGE_DOS_HEADER")
+       }
+       dosHeader := (*IMAGE_DOS_HEADER)(a2p(addr))
+       if dosHeader.E_magic != IMAGE_DOS_SIGNATURE {
+               return nil, fmt.Errorf("Not an MS-DOS binary (provided: %x, expected: %x)", dosHeader.E_magic, IMAGE_DOS_SIGNATURE)
+       }
+       if (size < uintptr(dosHeader.E_lfanew)+unsafe.Sizeof(IMAGE_NT_HEADERS{})) {
+               return nil, errors.New("Incomplete IMAGE_NT_HEADERS")
+       }
+       oldHeader := (*IMAGE_NT_HEADERS)(a2p(addr + uintptr(dosHeader.E_lfanew)))
+       if oldHeader.Signature != IMAGE_NT_SIGNATURE {
+               return nil, fmt.Errorf("Not an NT binary (provided: %x, expected: %x)", oldHeader.Signature, IMAGE_NT_SIGNATURE)
+       }
+       if oldHeader.FileHeader.Machine != imageFileProcess {
+               return nil, fmt.Errorf("Foreign platform (provided: %x, expected: %x)", oldHeader.FileHeader.Machine, imageFileProcess)
+       }
+       if (oldHeader.OptionalHeader.SectionAlignment & 1) != 0 {
+               return nil, errors.New("Unaligned section")
+       }
+       lastSectionEnd := uintptr(0)
+       sections := oldHeader.Sections()
+       optionalSectionSize := oldHeader.OptionalHeader.SectionAlignment
+       for i := range sections {
+               var endOfSection uintptr
+               if sections[i].SizeOfRawData == 0 {
+                       // Section without data in the DLL
+                       endOfSection = uintptr(sections[i].VirtualAddress) + uintptr(optionalSectionSize)
+               } else {
+                       endOfSection = uintptr(sections[i].VirtualAddress) + uintptr(sections[i].SizeOfRawData)
+               }
+               if endOfSection > lastSectionEnd {
+                       lastSectionEnd = endOfSection
+               }
+       }
+       alignedImageSize := alignUp(uintptr(oldHeader.OptionalHeader.SizeOfImage), uintptr(oldHeader.OptionalHeader.SectionAlignment))
+       if alignedImageSize != alignUp(lastSectionEnd, uintptr(oldHeader.OptionalHeader.SectionAlignment)) {
+               return nil, errors.New("Section is not page-aligned")
+       }
+
+       module = &Module{isDLL: (oldHeader.FileHeader.Characteristics & IMAGE_FILE_DLL) != 0}
+       defer func() {
+               if err != nil {
+                       module.Free()
+                       module = nil
+               }
+       }()
+
+       // Reserve memory for image of library.
+       // TODO: Is it correct to commit the complete memory region at once? Calling DllEntry raises an exception if we don't.
+       module.codeBase, err = windows.VirtualAlloc(oldHeader.OptionalHeader.ImageBase,
+               alignedImageSize,
+               windows.MEM_RESERVE|windows.MEM_COMMIT,
+               windows.PAGE_READWRITE)
+       if err != nil {
+               // Try to allocate memory at arbitrary position.
+               module.codeBase, err = windows.VirtualAlloc(0,
+                       alignedImageSize,
+                       windows.MEM_RESERVE|windows.MEM_COMMIT,
+                       windows.PAGE_READWRITE)
+               if err != nil {
+                       err = fmt.Errorf("Error allocating code: %v", err)
+                       return
+               }
+       }
+       err = module.check4GBBoundaries(alignedImageSize)
+       if err != nil {
+               err = fmt.Errorf("Error reallocating code: %v", err)
+               return
+       }
+
+       if size < uintptr(oldHeader.OptionalHeader.SizeOfHeaders) {
+               err = errors.New("Incomplete headers")
+               return
+       }
+       // Commit memory for headers.
+       headers, err := windows.VirtualAlloc(module.codeBase,
+               uintptr(oldHeader.OptionalHeader.SizeOfHeaders),
+               windows.MEM_COMMIT,
+               windows.PAGE_READWRITE)
+       if err != nil {
+               err = fmt.Errorf("Error allocating headers: %v", err)
+               return
+       }
+       // Copy PE header to code.
+       memcpy(headers, addr, uintptr(oldHeader.OptionalHeader.SizeOfHeaders))
+       module.headers = (*IMAGE_NT_HEADERS)(a2p(headers + uintptr(dosHeader.E_lfanew)))
+
+       // Update position.
+       module.headers.OptionalHeader.ImageBase = module.codeBase
+
+       // Copy sections from DLL file block to new memory location.
+       err = module.copySections(addr, size, oldHeader)
+       if err != nil {
+               err = fmt.Errorf("Error copying sections: %v", err)
+               return
+       }
+
+       // Adjust base address of imported data.
+       locationDelta := module.headers.OptionalHeader.ImageBase - oldHeader.OptionalHeader.ImageBase
+       if locationDelta != 0 {
+               module.isRelocated, err = module.performBaseRelocation(locationDelta)
+               if err != nil {
+                       err = fmt.Errorf("Error relocating module: %v", err)
+                       return
+               }
+       } else {
+               module.isRelocated = true
+       }
+
+       // Load required dlls and adjust function table of imports.
+       err = module.buildImportTable()
+       if err != nil {
+               err = fmt.Errorf("Error building import table: %v", err)
+               return
+       }
+
+       // Mark memory pages depending on section headers and release sections that are marked as "discardable".
+       err = module.finalizeSections()
+       if err != nil {
+               err = fmt.Errorf("Error finalizing sections: %v", err)
+               return
+       }
+
+       // TLS callbacks are executed BEFORE the main loading.
+       module.executeTLS()
+
+       // Get entry point of loaded module.
+       if module.headers.OptionalHeader.AddressOfEntryPoint != 0 {
+               module.entry = module.codeBase + uintptr(module.headers.OptionalHeader.AddressOfEntryPoint)
+               if module.isDLL {
+                       // Notify library about attaching to process.
+                       r0, _, _ := syscall.Syscall(module.entry, 3, module.codeBase, uintptr(DLL_PROCESS_ATTACH), 0)
+                       successful := r0 != 0
+                       if !successful {
+                               err = windows.ERROR_DLL_INIT_FAILED
+                               return
+                       }
+                       module.initialized = true
+               }
+       }
+
+       module.buildNameExports()
+       return
+}
+
+// Free releases module resources and unloads it.
+func (module *Module) Free() {
+       if module.initialized {
+               // Notify library about detaching from process.
+               syscall.Syscall(module.entry, 3, module.codeBase, uintptr(DLL_PROCESS_DETACH), 0)
+               module.initialized = false
+       }
+       if module.modules != nil {
+               // Free previously opened libraries.
+               for _, handle := range module.modules {
+                       windows.FreeLibrary(handle)
+               }
+               module.modules = nil
+       }
+       if module.codeBase != 0 {
+               windows.VirtualFree(module.codeBase, 0, windows.MEM_RELEASE)
+               module.codeBase = 0
+       }
+       if module.blockedMemory != nil {
+               module.blockedMemory.free()
+               module.blockedMemory = nil
+       }
+}
+
+// ProcAddressByName returns function address by exported name.
+func (module *Module) ProcAddressByName(name string) (uintptr, error) {
+       directory := module.headerDirectory(IMAGE_DIRECTORY_ENTRY_EXPORT)
+       if directory.Size == 0 {
+               return 0, errors.New("No export table found")
+       }
+       exports := (*IMAGE_EXPORT_DIRECTORY)(a2p(module.codeBase + uintptr(directory.VirtualAddress)))
+       if module.nameExports == nil {
+               return 0, errors.New("No functions exported by name")
+       }
+       if idx, ok := module.nameExports[name]; ok {
+               if uint32(idx) > exports.NumberOfFunctions {
+                       return 0, errors.New("Ordinal number too high")
+               }
+               // AddressOfFunctions contains the RVAs to the "real" functions.
+               return module.codeBase + uintptr(*(*uint32)(a2p(module.codeBase + uintptr(exports.AddressOfFunctions) + uintptr(idx)*4))), nil
+       }
+       return 0, errors.New("Function not found by name")
+}
+
+// ProcAddressByOrdinal returns function address by exported ordinal.
+func (module *Module) ProcAddressByOrdinal(ordinal uint16) (uintptr, error) {
+       directory := module.headerDirectory(IMAGE_DIRECTORY_ENTRY_EXPORT)
+       if directory.Size == 0 {
+               return 0, errors.New("No export table found")
+       }
+       exports := (*IMAGE_EXPORT_DIRECTORY)(a2p(module.codeBase + uintptr(directory.VirtualAddress)))
+       if uint32(ordinal) < exports.Base {
+               return 0, errors.New("Ordinal number too low")
+       }
+       idx := ordinal - uint16(exports.Base)
+       if uint32(idx) > exports.NumberOfFunctions {
+               return 0, errors.New("Ordinal number too high")
+       }
+       // AddressOfFunctions contains the RVAs to the "real" functions.
+       return module.codeBase + uintptr(*(*uint32)(a2p(module.codeBase + uintptr(exports.AddressOfFunctions) + uintptr(idx)*4))), nil
+}
+
+func alignDown(value, alignment uintptr) uintptr {
+       return value & ^(alignment - 1)
+}
+
+func alignUp(value, alignment uintptr) uintptr {
+       return (value + alignment - 1) & ^(alignment - 1)
+}
+
+func a2p(addr uintptr) unsafe.Pointer {
+       return unsafe.Pointer(addr)
+}
+
+func memcpy(dst, src, size uintptr) {
+       var d, s []byte
+       unsafeSlice(unsafe.Pointer(&d), a2p(dst), int(size))
+       unsafeSlice(unsafe.Pointer(&s), a2p(src), int(size))
+       copy(d, s)
+}
+
+// unsafeSlice updates the slice slicePtr to be a slice
+// referencing the provided data with its length & capacity set to
+// lenCap.
+//
+// TODO: when Go 1.16 or Go 1.17 is the minimum supported version,
+// update callers to use unsafe.Slice instead of this.
+func unsafeSlice(slicePtr, data unsafe.Pointer, lenCap int) {
+       type sliceHeader struct {
+               Data unsafe.Pointer
+               Len  int
+               Cap  int
+       }
+       h := (*sliceHeader)(slicePtr)
+       h.Data = data
+       h.Len = lenCap
+       h.Cap = lenCap
+}
diff --git a/tun/wintun/memmod/memmod_windows_32.go b/tun/wintun/memmod/memmod_windows_32.go
new file mode 100644 (file)
index 0000000..bd2e254
--- /dev/null
@@ -0,0 +1,16 @@
+// +build 386 arm
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+func (opthdr *IMAGE_OPTIONAL_HEADER) imageOffset() uintptr {
+       return 0
+}
+
+func (module *Module) check4GBBoundaries(alignedImageSize uintptr) (err error) {
+       return
+}
diff --git a/tun/wintun/memmod/memmod_windows_386.go b/tun/wintun/memmod/memmod_windows_386.go
new file mode 100644 (file)
index 0000000..16f3672
--- /dev/null
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+const imageFileProcess = IMAGE_FILE_MACHINE_I386
diff --git a/tun/wintun/memmod/memmod_windows_64.go b/tun/wintun/memmod/memmod_windows_64.go
new file mode 100644 (file)
index 0000000..46ac677
--- /dev/null
@@ -0,0 +1,36 @@
+// +build amd64 arm64
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+import (
+       "fmt"
+
+       "golang.org/x/sys/windows"
+)
+
+func (opthdr *IMAGE_OPTIONAL_HEADER) imageOffset() uintptr {
+       return uintptr(opthdr.ImageBase & 0xffffffff00000000)
+}
+
+func (module *Module) check4GBBoundaries(alignedImageSize uintptr) (err error) {
+       for (module.codeBase >> 32) < ((module.codeBase + alignedImageSize) >> 32) {
+               node := &addressList{
+                       next:    module.blockedMemory,
+                       address: module.codeBase,
+               }
+               module.blockedMemory = node
+               module.codeBase, err = windows.VirtualAlloc(0,
+                       alignedImageSize,
+                       windows.MEM_RESERVE|windows.MEM_COMMIT,
+                       windows.PAGE_READWRITE)
+               if err != nil {
+                       return fmt.Errorf("Error allocating memory block: %v", err)
+               }
+       }
+       return
+}
diff --git a/tun/wintun/memmod/memmod_windows_amd64.go b/tun/wintun/memmod/memmod_windows_amd64.go
new file mode 100644 (file)
index 0000000..934ae8e
--- /dev/null
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+const imageFileProcess = IMAGE_FILE_MACHINE_AMD64
diff --git a/tun/wintun/memmod/memmod_windows_arm.go b/tun/wintun/memmod/memmod_windows_arm.go
new file mode 100644 (file)
index 0000000..301f1b4
--- /dev/null
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+const imageFileProcess = IMAGE_FILE_MACHINE_ARMNT
diff --git a/tun/wintun/memmod/memmod_windows_arm64.go b/tun/wintun/memmod/memmod_windows_arm64.go
new file mode 100644 (file)
index 0000000..82fd2a6
--- /dev/null
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+const imageFileProcess = IMAGE_FILE_MACHINE_ARM64
diff --git a/tun/wintun/memmod/mksyscall.go b/tun/wintun/memmod/mksyscall.go
new file mode 100644 (file)
index 0000000..81400ea
--- /dev/null
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+//go:generate go run golang.org/x/sys/windows/mkwinsyscall -output zsyscall_windows.go syscall_windows.go
diff --git a/tun/wintun/memmod/syscall_windows.go b/tun/wintun/memmod/syscall_windows.go
new file mode 100644 (file)
index 0000000..beae415
--- /dev/null
@@ -0,0 +1,343 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+import "unsafe"
+
+const (
+       IMAGE_DOS_SIGNATURE    = 0x5A4D     // MZ
+       IMAGE_OS2_SIGNATURE    = 0x454E     // NE
+       IMAGE_OS2_SIGNATURE_LE = 0x454C     // LE
+       IMAGE_VXD_SIGNATURE    = 0x454C     // LE
+       IMAGE_NT_SIGNATURE     = 0x00004550 // PE00
+)
+
+// DOS .EXE header
+type IMAGE_DOS_HEADER struct {
+       E_magic    uint16     // Magic number
+       E_cblp     uint16     // Bytes on last page of file
+       E_cp       uint16     // Pages in file
+       E_crlc     uint16     // Relocations
+       E_cparhdr  uint16     // Size of header in paragraphs
+       E_minalloc uint16     // Minimum extra paragraphs needed
+       E_maxalloc uint16     // Maximum extra paragraphs needed
+       E_ss       uint16     // Initial (relative) SS value
+       E_sp       uint16     // Initial SP value
+       E_csum     uint16     // Checksum
+       E_ip       uint16     // Initial IP value
+       E_cs       uint16     // Initial (relative) CS value
+       E_lfarlc   uint16     // File address of relocation table
+       E_ovno     uint16     // Overlay number
+       E_res      [4]uint16  // Reserved words
+       E_oemid    uint16     // OEM identifier (for e_oeminfo)
+       E_oeminfo  uint16     // OEM information; e_oemid specific
+       E_res2     [10]uint16 // Reserved words
+       E_lfanew   int32      // File address of new exe header
+}
+
+// File header format
+type IMAGE_FILE_HEADER struct {
+       Machine              uint16
+       NumberOfSections     uint16
+       TimeDateStamp        uint32
+       PointerToSymbolTable uint32
+       NumberOfSymbols      uint32
+       SizeOfOptionalHeader uint16
+       Characteristics      uint16
+}
+
+const (
+       IMAGE_SIZEOF_FILE_HEADER = 20
+
+       IMAGE_FILE_RELOCS_STRIPPED         = 0x0001 // Relocation info stripped from file.
+       IMAGE_FILE_EXECUTABLE_IMAGE        = 0x0002 // File is executable  (i.e. no unresolved external references).
+       IMAGE_FILE_LINE_NUMS_STRIPPED      = 0x0004 // Line nunbers stripped from file.
+       IMAGE_FILE_LOCAL_SYMS_STRIPPED     = 0x0008 // Local symbols stripped from file.
+       IMAGE_FILE_AGGRESIVE_WS_TRIM       = 0x0010 // Aggressively trim working set
+       IMAGE_FILE_LARGE_ADDRESS_AWARE     = 0x0020 // App can handle >2gb addresses
+       IMAGE_FILE_BYTES_REVERSED_LO       = 0x0080 // Bytes of machine word are reversed.
+       IMAGE_FILE_32BIT_MACHINE           = 0x0100 // 32 bit word machine.
+       IMAGE_FILE_DEBUG_STRIPPED          = 0x0200 // Debugging info stripped from file in .DBG file
+       IMAGE_FILE_REMOVABLE_RUN_FROM_SWAP = 0x0400 // If Image is on removable media, copy and run from the swap file.
+       IMAGE_FILE_NET_RUN_FROM_SWAP       = 0x0800 // If Image is on Net, copy and run from the swap file.
+       IMAGE_FILE_SYSTEM                  = 0x1000 // System File.
+       IMAGE_FILE_DLL                     = 0x2000 // File is a DLL.
+       IMAGE_FILE_UP_SYSTEM_ONLY          = 0x4000 // File should only be run on a UP machine
+       IMAGE_FILE_BYTES_REVERSED_HI       = 0x8000 // Bytes of machine word are reversed.
+
+       IMAGE_FILE_MACHINE_UNKNOWN     = 0
+       IMAGE_FILE_MACHINE_TARGET_HOST = 0x0001 // Useful for indicating we want to interact with the host and not a WoW guest.
+       IMAGE_FILE_MACHINE_I386        = 0x014c // Intel 386.
+       IMAGE_FILE_MACHINE_R3000       = 0x0162 // MIPS little-endian, 0x160 big-endian
+       IMAGE_FILE_MACHINE_R4000       = 0x0166 // MIPS little-endian
+       IMAGE_FILE_MACHINE_R10000      = 0x0168 // MIPS little-endian
+       IMAGE_FILE_MACHINE_WCEMIPSV2   = 0x0169 // MIPS little-endian WCE v2
+       IMAGE_FILE_MACHINE_ALPHA       = 0x0184 // Alpha_AXP
+       IMAGE_FILE_MACHINE_SH3         = 0x01a2 // SH3 little-endian
+       IMAGE_FILE_MACHINE_SH3DSP      = 0x01a3
+       IMAGE_FILE_MACHINE_SH3E        = 0x01a4 // SH3E little-endian
+       IMAGE_FILE_MACHINE_SH4         = 0x01a6 // SH4 little-endian
+       IMAGE_FILE_MACHINE_SH5         = 0x01a8 // SH5
+       IMAGE_FILE_MACHINE_ARM         = 0x01c0 // ARM Little-Endian
+       IMAGE_FILE_MACHINE_THUMB       = 0x01c2 // ARM Thumb/Thumb-2 Little-Endian
+       IMAGE_FILE_MACHINE_ARMNT       = 0x01c4 // ARM Thumb-2 Little-Endian
+       IMAGE_FILE_MACHINE_AM33        = 0x01d3
+       IMAGE_FILE_MACHINE_POWERPC     = 0x01F0 // IBM PowerPC Little-Endian
+       IMAGE_FILE_MACHINE_POWERPCFP   = 0x01f1
+       IMAGE_FILE_MACHINE_IA64        = 0x0200 // Intel 64
+       IMAGE_FILE_MACHINE_MIPS16      = 0x0266 // MIPS
+       IMAGE_FILE_MACHINE_ALPHA64     = 0x0284 // ALPHA64
+       IMAGE_FILE_MACHINE_MIPSFPU     = 0x0366 // MIPS
+       IMAGE_FILE_MACHINE_MIPSFPU16   = 0x0466 // MIPS
+       IMAGE_FILE_MACHINE_AXP64       = IMAGE_FILE_MACHINE_ALPHA64
+       IMAGE_FILE_MACHINE_TRICORE     = 0x0520 // Infineon
+       IMAGE_FILE_MACHINE_CEF         = 0x0CEF
+       IMAGE_FILE_MACHINE_EBC         = 0x0EBC // EFI Byte Code
+       IMAGE_FILE_MACHINE_AMD64       = 0x8664 // AMD64 (K8)
+       IMAGE_FILE_MACHINE_M32R        = 0x9041 // M32R little-endian
+       IMAGE_FILE_MACHINE_ARM64       = 0xAA64 // ARM64 Little-Endian
+       IMAGE_FILE_MACHINE_CEE         = 0xC0EE
+)
+
+// Directory format
+type IMAGE_DATA_DIRECTORY struct {
+       VirtualAddress uint32
+       Size           uint32
+}
+
+const IMAGE_NUMBEROF_DIRECTORY_ENTRIES = 16
+
+type IMAGE_NT_HEADERS struct {
+       Signature      uint32
+       FileHeader     IMAGE_FILE_HEADER
+       OptionalHeader IMAGE_OPTIONAL_HEADER
+}
+
+func (ntheader *IMAGE_NT_HEADERS) Sections() []IMAGE_SECTION_HEADER {
+       return (*[0xffff]IMAGE_SECTION_HEADER)(unsafe.Pointer(
+               (uintptr)(unsafe.Pointer(ntheader)) +
+                       unsafe.Offsetof(ntheader.OptionalHeader) +
+                       uintptr(ntheader.FileHeader.SizeOfOptionalHeader)))[:ntheader.FileHeader.NumberOfSections]
+}
+
+const (
+       IMAGE_DIRECTORY_ENTRY_EXPORT         = 0  // Export Directory
+       IMAGE_DIRECTORY_ENTRY_IMPORT         = 1  // Import Directory
+       IMAGE_DIRECTORY_ENTRY_RESOURCE       = 2  // Resource Directory
+       IMAGE_DIRECTORY_ENTRY_EXCEPTION      = 3  // Exception Directory
+       IMAGE_DIRECTORY_ENTRY_SECURITY       = 4  // Security Directory
+       IMAGE_DIRECTORY_ENTRY_BASERELOC      = 5  // Base Relocation Table
+       IMAGE_DIRECTORY_ENTRY_DEBUG          = 6  // Debug Directory
+       IMAGE_DIRECTORY_ENTRY_COPYRIGHT      = 7  // (X86 usage)
+       IMAGE_DIRECTORY_ENTRY_ARCHITECTURE   = 7  // Architecture Specific Data
+       IMAGE_DIRECTORY_ENTRY_GLOBALPTR      = 8  // RVA of GP
+       IMAGE_DIRECTORY_ENTRY_TLS            = 9  // TLS Directory
+       IMAGE_DIRECTORY_ENTRY_LOAD_CONFIG    = 10 // Load Configuration Directory
+       IMAGE_DIRECTORY_ENTRY_BOUND_IMPORT   = 11 // Bound Import Directory in headers
+       IMAGE_DIRECTORY_ENTRY_IAT            = 12 // Import Address Table
+       IMAGE_DIRECTORY_ENTRY_DELAY_IMPORT   = 13 // Delay Load Import Descriptors
+       IMAGE_DIRECTORY_ENTRY_COM_DESCRIPTOR = 14 // COM Runtime descriptor
+)
+
+const IMAGE_SIZEOF_SHORT_NAME = 8
+
+// Section header format
+type IMAGE_SECTION_HEADER struct {
+       Name                         [IMAGE_SIZEOF_SHORT_NAME]byte
+       physicalAddressOrVirtualSize uint32
+       VirtualAddress               uint32
+       SizeOfRawData                uint32
+       PointerToRawData             uint32
+       PointerToRelocations         uint32
+       PointerToLinenumbers         uint32
+       NumberOfRelocations          uint16
+       NumberOfLinenumbers          uint16
+       Characteristics              uint32
+}
+
+func (ishdr *IMAGE_SECTION_HEADER) PhysicalAddress() uint32 {
+       return ishdr.physicalAddressOrVirtualSize
+}
+
+func (ishdr *IMAGE_SECTION_HEADER) SetPhysicalAddress(addr uint32) {
+       ishdr.physicalAddressOrVirtualSize = addr
+}
+
+func (ishdr *IMAGE_SECTION_HEADER) VirtualSize() uint32 {
+       return ishdr.physicalAddressOrVirtualSize
+}
+
+func (ishdr *IMAGE_SECTION_HEADER) SetVirtualSize(addr uint32) {
+       ishdr.physicalAddressOrVirtualSize = addr
+}
+
+const (
+       // Section characteristics.
+       IMAGE_SCN_TYPE_REG    = 0x00000000 // Reserved.
+       IMAGE_SCN_TYPE_DSECT  = 0x00000001 // Reserved.
+       IMAGE_SCN_TYPE_NOLOAD = 0x00000002 // Reserved.
+       IMAGE_SCN_TYPE_GROUP  = 0x00000004 // Reserved.
+       IMAGE_SCN_TYPE_NO_PAD = 0x00000008 // Reserved.
+       IMAGE_SCN_TYPE_COPY   = 0x00000010 // Reserved.
+
+       IMAGE_SCN_CNT_CODE               = 0x00000020 // Section contains code.
+       IMAGE_SCN_CNT_INITIALIZED_DATA   = 0x00000040 // Section contains initialized data.
+       IMAGE_SCN_CNT_UNINITIALIZED_DATA = 0x00000080 // Section contains uninitialized data.
+
+       IMAGE_SCN_LNK_OTHER         = 0x00000100 // Reserved.
+       IMAGE_SCN_LNK_INFO          = 0x00000200 // Section contains comments or some other type of information.
+       IMAGE_SCN_TYPE_OVER         = 0x00000400 // Reserved.
+       IMAGE_SCN_LNK_REMOVE        = 0x00000800 // Section contents will not become part of image.
+       IMAGE_SCN_LNK_COMDAT        = 0x00001000 // Section contents comdat.
+       IMAGE_SCN_MEM_PROTECTED     = 0x00004000 // Obsolete.
+       IMAGE_SCN_NO_DEFER_SPEC_EXC = 0x00004000 // Reset speculative exceptions handling bits in the TLB entries for this section.
+       IMAGE_SCN_GPREL             = 0x00008000 // Section content can be accessed relative to GP
+       IMAGE_SCN_MEM_FARDATA       = 0x00008000
+       IMAGE_SCN_MEM_SYSHEAP       = 0x00010000 // Obsolete.
+       IMAGE_SCN_MEM_PURGEABLE     = 0x00020000
+       IMAGE_SCN_MEM_16BIT         = 0x00020000
+       IMAGE_SCN_MEM_LOCKED        = 0x00040000
+       IMAGE_SCN_MEM_PRELOAD       = 0x00080000
+
+       IMAGE_SCN_ALIGN_1BYTES    = 0x00100000 //
+       IMAGE_SCN_ALIGN_2BYTES    = 0x00200000 //
+       IMAGE_SCN_ALIGN_4BYTES    = 0x00300000 //
+       IMAGE_SCN_ALIGN_8BYTES    = 0x00400000 //
+       IMAGE_SCN_ALIGN_16BYTES   = 0x00500000 // Default alignment if no others are specified.
+       IMAGE_SCN_ALIGN_32BYTES   = 0x00600000 //
+       IMAGE_SCN_ALIGN_64BYTES   = 0x00700000 //
+       IMAGE_SCN_ALIGN_128BYTES  = 0x00800000 //
+       IMAGE_SCN_ALIGN_256BYTES  = 0x00900000 //
+       IMAGE_SCN_ALIGN_512BYTES  = 0x00A00000 //
+       IMAGE_SCN_ALIGN_1024BYTES = 0x00B00000 //
+       IMAGE_SCN_ALIGN_2048BYTES = 0x00C00000 //
+       IMAGE_SCN_ALIGN_4096BYTES = 0x00D00000 //
+       IMAGE_SCN_ALIGN_8192BYTES = 0x00E00000 //
+       IMAGE_SCN_ALIGN_MASK      = 0x00F00000
+
+       IMAGE_SCN_LNK_NRELOC_OVFL = 0x01000000 // Section contains extended relocations.
+       IMAGE_SCN_MEM_DISCARDABLE = 0x02000000 // Section can be discarded.
+       IMAGE_SCN_MEM_NOT_CACHED  = 0x04000000 // Section is not cachable.
+       IMAGE_SCN_MEM_NOT_PAGED   = 0x08000000 // Section is not pageable.
+       IMAGE_SCN_MEM_SHARED      = 0x10000000 // Section is shareable.
+       IMAGE_SCN_MEM_EXECUTE     = 0x20000000 // Section is executable.
+       IMAGE_SCN_MEM_READ        = 0x40000000 // Section is readable.
+       IMAGE_SCN_MEM_WRITE       = 0x80000000 // Section is writeable.
+
+       // TLS Characteristic Flags
+       IMAGE_SCN_SCALE_INDEX = 0x00000001 // Tls index is scaled.
+)
+
+// Based relocation format
+type IMAGE_BASE_RELOCATION struct {
+       VirtualAddress uint32
+       SizeOfBlock    uint32
+}
+
+const (
+       IMAGE_REL_BASED_ABSOLUTE           = 0
+       IMAGE_REL_BASED_HIGH               = 1
+       IMAGE_REL_BASED_LOW                = 2
+       IMAGE_REL_BASED_HIGHLOW            = 3
+       IMAGE_REL_BASED_HIGHADJ            = 4
+       IMAGE_REL_BASED_MACHINE_SPECIFIC_5 = 5
+       IMAGE_REL_BASED_RESERVED           = 6
+       IMAGE_REL_BASED_MACHINE_SPECIFIC_7 = 7
+       IMAGE_REL_BASED_MACHINE_SPECIFIC_8 = 8
+       IMAGE_REL_BASED_MACHINE_SPECIFIC_9 = 9
+       IMAGE_REL_BASED_DIR64              = 10
+
+       IMAGE_REL_BASED_IA64_IMM64 = 9
+
+       IMAGE_REL_BASED_MIPS_JMPADDR   = 5
+       IMAGE_REL_BASED_MIPS_JMPADDR16 = 9
+
+       IMAGE_REL_BASED_ARM_MOV32   = 5
+       IMAGE_REL_BASED_THUMB_MOV32 = 7
+)
+
+// Export Format
+type IMAGE_EXPORT_DIRECTORY struct {
+       Characteristics       uint32
+       TimeDateStamp         uint32
+       MajorVersion          uint16
+       MinorVersion          uint16
+       Name                  uint32
+       Base                  uint32
+       NumberOfFunctions     uint32
+       NumberOfNames         uint32
+       AddressOfFunctions    uint32 // RVA from base of image
+       AddressOfNames        uint32 // RVA from base of image
+       AddressOfNameOrdinals uint32 // RVA from base of image
+}
+
+type IMAGE_IMPORT_BY_NAME struct {
+       Hint uint16
+       Name [1]byte
+}
+
+func IMAGE_ORDINAL(ordinal uintptr) uintptr {
+       return ordinal & 0xffff
+}
+
+func IMAGE_SNAP_BY_ORDINAL(ordinal uintptr) bool {
+       return (ordinal & IMAGE_ORDINAL_FLAG) != 0
+}
+
+// Thread Local Storage
+type IMAGE_TLS_DIRECTORY struct {
+       StartAddressOfRawData uintptr
+       EndAddressOfRawData   uintptr
+       AddressOfIndex        uintptr // PDWORD
+       AddressOfCallbacks    uintptr // PIMAGE_TLS_CALLBACK *;
+       SizeOfZeroFill        uint32
+       Characteristics       uint32
+}
+
+type IMAGE_IMPORT_DESCRIPTOR struct {
+       characteristicsOrOriginalFirstThunk uint32 // 0 for terminating null import descriptor
+       // RVA to original unbound IAT (PIMAGE_THUNK_DATA)
+       TimeDateStamp uint32 // 0 if not bound,
+       // -1 if bound, and real date\time stamp
+       //     in IMAGE_DIRECTORY_ENTRY_BOUND_IMPORT (new BIND)
+       // O.W. date/time stamp of DLL bound to (Old BIND)
+       ForwarderChain uint32 // -1 if no forwarders
+       Name           uint32
+       FirstThunk     uint32 // RVA to IAT (if bound this IAT has actual addresses)
+}
+
+func (imgimpdesc *IMAGE_IMPORT_DESCRIPTOR) Characteristics() uint32 {
+       return imgimpdesc.characteristicsOrOriginalFirstThunk
+}
+
+func (imgimpdesc *IMAGE_IMPORT_DESCRIPTOR) OriginalFirstThunk() uint32 {
+       return imgimpdesc.characteristicsOrOriginalFirstThunk
+}
+
+const (
+       DLL_PROCESS_ATTACH = 1
+       DLL_THREAD_ATTACH  = 2
+       DLL_THREAD_DETACH  = 3
+       DLL_PROCESS_DETACH = 0
+)
+
+//sys  loadLibraryA(libFileName *byte) (module windows.Handle, err error) = kernel32.LoadLibraryA
+//sys  getProcAddress(module windows.Handle, procName *byte) (addr uintptr, err error) = kernel32.GetProcAddress
+//sys  isBadReadPtr(addr uintptr, ucb uintptr) (ret bool) = kernel32.IsBadReadPtr
+
+type SYSTEM_INFO struct {
+       ProcessorArchitecture     uint16
+       Reserved                  uint16
+       PageSize                  uint32
+       MinimumApplicationAddress uintptr
+       MaximumApplicationAddress uintptr
+       ActiveProcessorMask       uintptr
+       NumberOfProcessors        uint32
+       ProcessorType             uint32
+       AllocationGranularity     uint32
+       ProcessorLevel            uint16
+       ProcessorRevision         uint16
+}
diff --git a/tun/wintun/memmod/syscall_windows_32.go b/tun/wintun/memmod/syscall_windows_32.go
new file mode 100644 (file)
index 0000000..167d5fc
--- /dev/null
@@ -0,0 +1,45 @@
+// +build 386 arm
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+// Optional header format
+type IMAGE_OPTIONAL_HEADER struct {
+       Magic                       uint16
+       MajorLinkerVersion          uint8
+       MinorLinkerVersion          uint8
+       SizeOfCode                  uint32
+       SizeOfInitializedData       uint32
+       SizeOfUninitializedData     uint32
+       AddressOfEntryPoint         uint32
+       BaseOfCode                  uint32
+       BaseOfData                  uint32
+       ImageBase                   uintptr
+       SectionAlignment            uint32
+       FileAlignment               uint32
+       MajorOperatingSystemVersion uint16
+       MinorOperatingSystemVersion uint16
+       MajorImageVersion           uint16
+       MinorImageVersion           uint16
+       MajorSubsystemVersion       uint16
+       MinorSubsystemVersion       uint16
+       Win32VersionValue           uint32
+       SizeOfImage                 uint32
+       SizeOfHeaders               uint32
+       CheckSum                    uint32
+       Subsystem                   uint16
+       DllCharacteristics          uint16
+       SizeOfStackReserve          uintptr
+       SizeOfStackCommit           uintptr
+       SizeOfHeapReserve           uintptr
+       SizeOfHeapCommit            uintptr
+       LoaderFlags                 uint32
+       NumberOfRvaAndSizes         uint32
+       DataDirectory               [IMAGE_NUMBEROF_DIRECTORY_ENTRIES]IMAGE_DATA_DIRECTORY
+}
+
+const IMAGE_ORDINAL_FLAG uintptr = 0x80000000
diff --git a/tun/wintun/memmod/syscall_windows_64.go b/tun/wintun/memmod/syscall_windows_64.go
new file mode 100644 (file)
index 0000000..888acc4
--- /dev/null
@@ -0,0 +1,44 @@
+// +build amd64 arm64
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+// Optional header format
+type IMAGE_OPTIONAL_HEADER struct {
+       Magic                       uint16
+       MajorLinkerVersion          uint8
+       MinorLinkerVersion          uint8
+       SizeOfCode                  uint32
+       SizeOfInitializedData       uint32
+       SizeOfUninitializedData     uint32
+       AddressOfEntryPoint         uint32
+       BaseOfCode                  uint32
+       ImageBase                   uintptr
+       SectionAlignment            uint32
+       FileAlignment               uint32
+       MajorOperatingSystemVersion uint16
+       MinorOperatingSystemVersion uint16
+       MajorImageVersion           uint16
+       MinorImageVersion           uint16
+       MajorSubsystemVersion       uint16
+       MinorSubsystemVersion       uint16
+       Win32VersionValue           uint32
+       SizeOfImage                 uint32
+       SizeOfHeaders               uint32
+       CheckSum                    uint32
+       Subsystem                   uint16
+       DllCharacteristics          uint16
+       SizeOfStackReserve          uintptr
+       SizeOfStackCommit           uintptr
+       SizeOfHeapReserve           uintptr
+       SizeOfHeapCommit            uintptr
+       LoaderFlags                 uint32
+       NumberOfRvaAndSizes         uint32
+       DataDirectory               [IMAGE_NUMBEROF_DIRECTORY_ENTRIES]IMAGE_DATA_DIRECTORY
+}
+
+const IMAGE_ORDINAL_FLAG uintptr = 0x8000000000000000
diff --git a/tun/wintun/memmod/zsyscall_windows.go b/tun/wintun/memmod/zsyscall_windows.go
new file mode 100644 (file)
index 0000000..c56b650
--- /dev/null
@@ -0,0 +1,70 @@
+// Code generated by 'go generate'; DO NOT EDIT.
+
+package memmod
+
+import (
+       "syscall"
+       "unsafe"
+
+       "golang.org/x/sys/windows"
+)
+
+var _ unsafe.Pointer
+
+// Do the interface allocations only once for common
+// Errno values.
+const (
+       errnoERROR_IO_PENDING = 997
+)
+
+var (
+       errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+       errERROR_EINVAL     error = syscall.EINVAL
+)
+
+// errnoErr returns common boxed Errno values, to prevent
+// allocations at runtime.
+func errnoErr(e syscall.Errno) error {
+       switch e {
+       case 0:
+               return errERROR_EINVAL
+       case errnoERROR_IO_PENDING:
+               return errERROR_IO_PENDING
+       }
+       // TODO: add more here, after collecting data on the common
+       // error values see on Windows. (perhaps when running
+       // all.bat?)
+       return e
+}
+
+var (
+       modkernel32 = windows.NewLazySystemDLL("kernel32.dll")
+
+       procGetProcAddress = modkernel32.NewProc("GetProcAddress")
+       procIsBadReadPtr   = modkernel32.NewProc("IsBadReadPtr")
+       procLoadLibraryA   = modkernel32.NewProc("LoadLibraryA")
+)
+
+func getProcAddress(module windows.Handle, procName *byte) (addr uintptr, err error) {
+       r0, _, e1 := syscall.Syscall(procGetProcAddress.Addr(), 2, uintptr(module), uintptr(unsafe.Pointer(procName)), 0)
+       addr = uintptr(r0)
+       if addr == 0 {
+               err = errnoErr(e1)
+       }
+       return
+}
+
+func isBadReadPtr(addr uintptr, ucb uintptr) (ret bool) {
+       r0, _, _ := syscall.Syscall(procIsBadReadPtr.Addr(), 2, uintptr(addr), uintptr(ucb), 0)
+       ret = r0 != 0
+       return
+}
+
+func loadLibraryA(libFileName *byte) (module windows.Handle, err error) {
+       r0, _, e1 := syscall.Syscall(procLoadLibraryA.Addr(), 1, uintptr(unsafe.Pointer(libFileName)), 0, 0)
+       module = windows.Handle(r0)
+       if module == 0 {
+               err = errnoErr(e1)
+       }
+       return
+}
diff --git a/tun/wintun/resource/mksyscall.go b/tun/wintun/resource/mksyscall.go
new file mode 100644 (file)
index 0000000..9235614
--- /dev/null
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package resource
+
+//go:generate go run golang.org/x/sys/windows/mkwinsyscall -output zsyscall_windows.go resource_windows.go
diff --git a/tun/wintun/resource/resource_windows.go b/tun/wintun/resource/resource_windows.go
new file mode 100644 (file)
index 0000000..109c2ca
--- /dev/null
@@ -0,0 +1,143 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package resource
+
+import (
+       "errors"
+       "fmt"
+       "unsafe"
+
+       "golang.org/x/sys/windows"
+)
+
+func MAKEINTRESOURCE(i uint16) *uint16 {
+       return (*uint16)(unsafe.Pointer(uintptr(i)))
+}
+
+// Predefined Resource Types
+var (
+       VS_VERSION_INFO uint16 = 1
+
+       RT_CURSOR                                          = MAKEINTRESOURCE(1)
+       RT_BITMAP                                          = MAKEINTRESOURCE(2)
+       RT_ICON                                            = MAKEINTRESOURCE(3)
+       RT_MENU                                            = MAKEINTRESOURCE(4)
+       RT_DIALOG                                          = MAKEINTRESOURCE(5)
+       RT_STRING                                          = MAKEINTRESOURCE(6)
+       RT_FONTDIR                                         = MAKEINTRESOURCE(7)
+       RT_FONT                                            = MAKEINTRESOURCE(8)
+       RT_ACCELERATOR                                     = MAKEINTRESOURCE(9)
+       RT_RCDATA                                          = MAKEINTRESOURCE(10)
+       RT_MESSAGETABLE                                    = MAKEINTRESOURCE(11)
+       RT_GROUP_CURSOR                                    = MAKEINTRESOURCE(12)
+       RT_GROUP_ICON                                      = MAKEINTRESOURCE(14)
+       RT_VERSION                                         = MAKEINTRESOURCE(16)
+       RT_DLGINCLUDE                                      = MAKEINTRESOURCE(17)
+       RT_PLUGPLAY                                        = MAKEINTRESOURCE(19)
+       RT_VXD                                             = MAKEINTRESOURCE(20)
+       RT_ANICURSOR                                       = MAKEINTRESOURCE(21)
+       RT_ANIICON                                         = MAKEINTRESOURCE(22)
+       RT_HTML                                            = MAKEINTRESOURCE(23)
+       RT_MANIFEST                                        = MAKEINTRESOURCE(24)
+       CREATEPROCESS_MANIFEST_RESOURCE_ID                 = MAKEINTRESOURCE(1)
+       ISOLATIONAWARE_MANIFEST_RESOURCE_ID                = MAKEINTRESOURCE(2)
+       ISOLATIONAWARE_NOSTATICIMPORT_MANIFEST_RESOURCE_ID = MAKEINTRESOURCE(3)
+       ISOLATIONPOLICY_MANIFEST_RESOURCE_ID               = MAKEINTRESOURCE(4)
+       ISOLATIONPOLICY_BROWSER_MANIFEST_RESOURCE_ID       = MAKEINTRESOURCE(5)
+       MINIMUM_RESERVED_MANIFEST_RESOURCE_ID              = MAKEINTRESOURCE(1 /*inclusive*/)
+       MAXIMUM_RESERVED_MANIFEST_RESOURCE_ID              = MAKEINTRESOURCE(16 /*inclusive*/)
+)
+
+//sys  findResource(module windows.Handle, name *uint16, resType *uint16) (resInfo windows.Handle, err error) = kernel32.FindResourceW
+
+func FindByID(module windows.Handle, id uint16, resType *uint16) (resInfo windows.Handle, err error) {
+       return findResource(module, MAKEINTRESOURCE(id), resType)
+}
+
+func FindByName(module windows.Handle, name string, resType *uint16) (resInfo windows.Handle, err error) {
+       var name16 *uint16
+       name16, err = windows.UTF16PtrFromString(name)
+       if err != nil {
+               return
+       }
+       resInfo, err = findResource(module, name16, resType)
+       return
+}
+
+//sys  sizeofResource(module windows.Handle, resInfo windows.Handle) (size uint32, err error) = kernel32.SizeofResource
+//sys  loadResource(module windows.Handle, resInfo windows.Handle) (resData windows.Handle, err error) = kernel32.LoadResource
+//sys  lockResource(resData windows.Handle) (addr uintptr, err error) = kernel32.LockResource
+
+func Load(module, resInfo windows.Handle) (data []byte, err error) {
+       size, err := sizeofResource(module, resInfo)
+       if err != nil {
+               err = fmt.Errorf("Unable to size resource: %v", err)
+               return
+       }
+       resData, err := loadResource(module, resInfo)
+       if err != nil {
+               err = fmt.Errorf("Unable to load resource: %v", err)
+               return
+       }
+       ptr, err := lockResource(resData)
+       if err != nil {
+               err = fmt.Errorf("Unable to lock resource: %v", err)
+               return
+       }
+       unsafeSlice(unsafe.Pointer(&data), unsafe.Pointer(ptr), int(size))
+       return
+}
+
+type VS_FIXEDFILEINFO struct {
+       Signature        uint32
+       StrucVersion     uint32
+       FileVersionMS    uint32
+       FileVersionLS    uint32
+       ProductVersionMS uint32
+       ProductVersionLS uint32
+       FileFlagsMask    uint32
+       FileFlags        uint32
+       FileOS           uint32
+       FileType         uint32
+       FileSubtype      uint32
+       FileDateMS       uint32
+       FileDateLS       uint32
+}
+
+//sys  verQueryValue(block *byte, section *uint16, value **byte, size *uint32) (err error) = version.VerQueryValueW
+
+func VerQueryRootValue(block []byte) (ffi *VS_FIXEDFILEINFO, err error) {
+       var data *byte
+       var size uint32
+       err = verQueryValue(&block[0], windows.StringToUTF16Ptr("\\"), &data, &size)
+       if err != nil {
+               return
+       }
+       if uintptr(size) < unsafe.Sizeof(VS_FIXEDFILEINFO{}) {
+               err = errors.New("Incomplete VS_FIXEDFILEINFO")
+               return
+       }
+       ffi = (*VS_FIXEDFILEINFO)(unsafe.Pointer(data))
+       return
+}
+
+// unsafeSlice updates the slice slicePtr to be a slice
+// referencing the provided data with its length & capacity set to
+// lenCap.
+//
+// TODO: when Go 1.16 or Go 1.17 is the minimum supported version,
+// update callers to use unsafe.Slice instead of this.
+func unsafeSlice(slicePtr, data unsafe.Pointer, lenCap int) {
+       type sliceHeader struct {
+               Data unsafe.Pointer
+               Len  int
+               Cap  int
+       }
+       h := (*sliceHeader)(slicePtr)
+       h.Data = data
+       h.Len = lenCap
+       h.Cap = lenCap
+}
diff --git a/tun/wintun/resource/zsyscall_windows.go b/tun/wintun/resource/zsyscall_windows.go
new file mode 100644 (file)
index 0000000..e4c4bf1
--- /dev/null
@@ -0,0 +1,112 @@
+// Code generated by 'go generate'; DO NOT EDIT.
+
+package resource
+
+import (
+       "syscall"
+       "unsafe"
+
+       "golang.org/x/sys/windows"
+)
+
+var _ unsafe.Pointer
+
+// Do the interface allocations only once for common
+// Errno values.
+const (
+       errnoERROR_IO_PENDING = 997
+)
+
+var (
+       errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+)
+
+// errnoErr returns common boxed Errno values, to prevent
+// allocations at runtime.
+func errnoErr(e syscall.Errno) error {
+       switch e {
+       case 0:
+               return nil
+       case errnoERROR_IO_PENDING:
+               return errERROR_IO_PENDING
+       }
+       // TODO: add more here, after collecting data on the common
+       // error values see on Windows. (perhaps when running
+       // all.bat?)
+       return e
+}
+
+var (
+       modkernel32 = windows.NewLazySystemDLL("kernel32.dll")
+       modversion  = windows.NewLazySystemDLL("version.dll")
+
+       procFindResourceW  = modkernel32.NewProc("FindResourceW")
+       procSizeofResource = modkernel32.NewProc("SizeofResource")
+       procLoadResource   = modkernel32.NewProc("LoadResource")
+       procLockResource   = modkernel32.NewProc("LockResource")
+       procVerQueryValueW = modversion.NewProc("VerQueryValueW")
+)
+
+func findResource(module windows.Handle, name *uint16, resType *uint16) (resInfo windows.Handle, err error) {
+       r0, _, e1 := syscall.Syscall(procFindResourceW.Addr(), 3, uintptr(module), uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(resType)))
+       resInfo = windows.Handle(r0)
+       if resInfo == 0 {
+               if e1 != 0 {
+                       err = errnoErr(e1)
+               } else {
+                       err = syscall.EINVAL
+               }
+       }
+       return
+}
+
+func sizeofResource(module windows.Handle, resInfo windows.Handle) (size uint32, err error) {
+       r0, _, e1 := syscall.Syscall(procSizeofResource.Addr(), 2, uintptr(module), uintptr(resInfo), 0)
+       size = uint32(r0)
+       if size == 0 {
+               if e1 != 0 {
+                       err = errnoErr(e1)
+               } else {
+                       err = syscall.EINVAL
+               }
+       }
+       return
+}
+
+func loadResource(module windows.Handle, resInfo windows.Handle) (resData windows.Handle, err error) {
+       r0, _, e1 := syscall.Syscall(procLoadResource.Addr(), 2, uintptr(module), uintptr(resInfo), 0)
+       resData = windows.Handle(r0)
+       if resData == 0 {
+               if e1 != 0 {
+                       err = errnoErr(e1)
+               } else {
+                       err = syscall.EINVAL
+               }
+       }
+       return
+}
+
+func lockResource(resData windows.Handle) (addr uintptr, err error) {
+       r0, _, e1 := syscall.Syscall(procLockResource.Addr(), 1, uintptr(resData), 0, 0)
+       addr = uintptr(r0)
+       if addr == 0 {
+               if e1 != 0 {
+                       err = errnoErr(e1)
+               } else {
+                       err = syscall.EINVAL
+               }
+       }
+       return
+}
+
+func verQueryValue(block *byte, section *uint16, value **byte, size *uint32) (err error) {
+       r1, _, e1 := syscall.Syscall6(procVerQueryValueW.Addr(), 4, uintptr(unsafe.Pointer(block)), uintptr(unsafe.Pointer(section)), uintptr(unsafe.Pointer(value)), uintptr(unsafe.Pointer(size)), 0, 0)
+       if r1 == 0 {
+               if e1 != 0 {
+                       err = errnoErr(e1)
+               } else {
+                       err = syscall.EINVAL
+               }
+       }
+       return
+}
index 14b0260cadc93d29615fb9e99eb1e368ddb17b93..ac3357992063cd613ecb95db1447f811e51a8867 100644 (file)
@@ -34,7 +34,7 @@ type Adapter struct {
 }
 
 var (
-       modwintun = windows.NewLazyDLL("wintun.dll")
+       modwintun = newLazyDLL("wintun.dll")
 
        procWintunCreateAdapter           = modwintun.NewProc("WintunCreateAdapter")
        procWintunDeleteAdapter           = modwintun.NewProc("WintunDeleteAdapter")