initial commit

Makefile

+all: build
+
+deps:
+	go get ./...
+
+build:
+	go build
+
+install: build
+	go install
+
+watch:
+	-make build
+	@echo "[watching *.go for recompilation]"
+	# for portability, use watchmedo -- pip install watchmedo
+	@watchmedo shell-command --patterns="*.go;" --recursive \
+		--command='make build' .

sockaddr.go

+package sockaddr
+
+import (
+	"syscall"
+)
+
+type Socklen uint
+
+type RawSockaddr struct {
+	Raw syscall.RawSockaddrAny
+	Len Socklen
+}
+
+func NewRawSockaddr(s *syscall.Sockaddr) (*RawSockaddr, error) {
+	r := new(RawSockaddr)
+	err := r.Update(s)
+	return r, err
+}

sockaddr_bsd.go

+// sockaddr syscall extensions
+package sockaddr
+
+import (
+	"fmt"
+	"syscall"
+	"unsafe"
+)
+
+func (r *RawSockaddr) Update(s *syscall.Sockaddr) error {
+
+	si4, ok := (*s).(*syscall.SockaddrInet4)
+	if ok {
+		return r.UpdateInet4(si4)
+	}
+
+	si6, ok := (*s).(*syscall.SockaddrInet6)
+	if ok {
+		return r.UpdateInet6(si6)
+	}
+
+	su, ok := (*s).(*syscall.SockaddrUnix)
+	if ok {
+		return r.UpdateUnix(su)
+	}
+
+	sdl, ok := (*s).(*syscall.SockaddrDatalink)
+	if ok {
+		return r.UpdateDatalink(sdl)
+	}
+
+	return fmt.Errorf("unknown sockaddr type")
+}
+
+func (r *RawSockaddr) UpdateInet4(sa *syscall.SockaddrInet4) error {
+	if sa.Port < 0 || sa.Port > 0xFFFF {
+		return syscall.EINVAL
+	}
+	raw := (*syscall.RawSockaddrInet4)(unsafe.Pointer(&r.Raw))
+	raw.Len = syscall.SizeofSockaddrInet4
+	raw.Family = syscall.AF_INET
+	p := (*[2]byte)(unsafe.Pointer(&raw.Port))
+	p[0] = byte(sa.Port >> 8)
+	p[1] = byte(sa.Port)
+	for i := 0; i < len(sa.Addr); i++ {
+		raw.Addr[i] = sa.Addr[i]
+	}
+	r.Len = Socklen(raw.Len)
+	return nil
+}
+
+func (r *RawSockaddr) UpdateInet6(sa *syscall.SockaddrInet6) error {
+	if sa.Port < 0 || sa.Port > 0xFFFF {
+		return syscall.EINVAL
+	}
+	raw := (*syscall.RawSockaddrInet6)(unsafe.Pointer(&r.Raw))
+	raw.Len = syscall.SizeofSockaddrInet6
+	raw.Family = syscall.AF_INET6
+	p := (*[2]byte)(unsafe.Pointer(&raw.Port))
+	p[0] = byte(sa.Port >> 8)
+	p[1] = byte(sa.Port)
+	raw.Scope_id = sa.ZoneId
+	for i := 0; i < len(sa.Addr); i++ {
+		raw.Addr[i] = sa.Addr[i]
+	}
+	r.Len = Socklen(raw.Len)
+	return nil
+}
+
+func (r *RawSockaddr) UpdateUnix(sa *syscall.SockaddrUnix) error {
+	raw := (*syscall.RawSockaddrUnix)(unsafe.Pointer(&r.Raw))
+	name := sa.Name
+	n := len(name)
+	if n >= len(raw.Path) || n == 0 {
+		return syscall.EINVAL
+	}
+	raw.Len = byte(3 + n) // 2 for Family, Len; 1 for NUL
+	raw.Family = syscall.AF_UNIX
+	for i := 0; i < n; i++ {
+		raw.Path[i] = int8(name[i])
+	}
+	r.Len = Socklen(raw.Len)
+	return nil
+}
+
+func (r *RawSockaddr) UpdateDatalink(sa *syscall.SockaddrDatalink) error {
+	if sa.Index == 0 {
+		return syscall.EINVAL
+	}
+	raw := (*syscall.RawSockaddrDatalink)(unsafe.Pointer(&r.Raw))
+	raw.Len = sa.Len
+	raw.Family = syscall.AF_LINK
+	raw.Index = sa.Index
+	raw.Type = sa.Type
+	raw.Nlen = sa.Nlen
+	raw.Alen = sa.Alen
+	raw.Slen = sa.Slen
+	for i := 0; i < len(raw.Data); i++ {
+		raw.Data[i] = sa.Data[i]
+	}
+	r.Len = Socklen(syscall.SizeofSockaddrDatalink)
+	return nil
+}
+
+func AnyToSockaddr(rsa *syscall.RawSockaddrAny) (syscall.Sockaddr, error) {
+	switch rsa.Addr.Family {
+	case syscall.AF_LINK:
+		pp := (*syscall.RawSockaddrDatalink)(unsafe.Pointer(rsa))
+		sa := new(syscall.SockaddrDatalink)
+		sa.Len = pp.Len
+		sa.Family = pp.Family
+		sa.Index = pp.Index
+		sa.Type = pp.Type
+		sa.Nlen = pp.Nlen
+		sa.Alen = pp.Alen
+		sa.Slen = pp.Slen
+		for i := 0; i < len(sa.Data); i++ {
+			sa.Data[i] = pp.Data[i]
+		}
+		return sa, nil
+
+	case syscall.AF_UNIX:
+		pp := (*syscall.RawSockaddrUnix)(unsafe.Pointer(rsa))
+		if pp.Len < 3 || pp.Len > syscall.SizeofSockaddrUnix {
+			return nil, syscall.EINVAL
+		}
+		sa := new(syscall.SockaddrUnix)
+		n := int(pp.Len) - 3 // subtract leading Family, Len, terminating NUL
+		for i := 0; i < n; i++ {
+			if pp.Path[i] == 0 {
+				// found early NUL; assume Len is overestimating
+				n = i
+				break
+			}
+		}
+		bytes := (*[10000]byte)(unsafe.Pointer(&pp.Path[0]))[0:n]
+		sa.Name = string(bytes)
+		return sa, nil
+
+	case syscall.AF_INET:
+		pp := (*syscall.RawSockaddrInet4)(unsafe.Pointer(rsa))
+		sa := new(syscall.SockaddrInet4)
+		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
+		sa.Port = int(p[0])<<8 + int(p[1])
+		for i := 0; i < len(sa.Addr); i++ {
+			sa.Addr[i] = pp.Addr[i]
+		}
+		return sa, nil
+
+	case syscall.AF_INET6:
+		pp := (*syscall.RawSockaddrInet6)(unsafe.Pointer(rsa))
+		sa := new(syscall.SockaddrInet6)
+		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
+		sa.Port = int(p[0])<<8 + int(p[1])
+		sa.ZoneId = pp.Scope_id
+		for i := 0; i < len(sa.Addr); i++ {
+			sa.Addr[i] = pp.Addr[i]
+		}
+		return sa, nil
+	}
+	return nil, syscall.EAFNOSUPPORT
+}

sockaddr_linux.go

+// sockaddr syscall extensions
+package sockaddr
+
+import (
+	"fmt"
+	"syscall"
+	"unsafe"
+)
+
+func (r *RawSockaddr) Update(s *syscall.Sockaddr) error {
+
+	si4, ok := (*s).(*syscall.SockaddrInet4)
+	if ok {
+		return r.UpdateInet4(si4)
+	}
+
+	si6, ok := (*s).(*syscall.SockaddrInet6)
+	if ok {
+		return r.UpdateInet6(si6)
+	}
+
+	su, ok := (*s).(*syscall.SockaddrUnix)
+	if ok {
+		return r.UpdateUnix(su)
+	}
+
+	sdl, ok := (*s).(*syscall.SockaddrDatalink)
+	if ok {
+		return r.UpdateDatalink(sdl)
+	}
+
+	return fmt.Errorf("unknown sockaddr type")
+}
+
+func (r *RawSockaddr) UpdateInet4(sa *syscall.SockaddrInet4) error {
+	if sa.Port < 0 || sa.Port > 0xFFFF {
+		return syscall.EINVAL
+	}
+	raw := (*syscall.RawSockaddrInet4)(unsafe.Pointer(&r.Raw))
+	raw.Family = syscall.AF_INET
+	p := (*[2]byte)(unsafe.Pointer(&raw.Port))
+	p[0] = byte(sa.Port >> 8)
+	p[1] = byte(sa.Port)
+	for i := 0; i < len(sa.Addr); i++ {
+		raw.Addr[i] = sa.Addr[i]
+	}
+	r.Len = Socklen(syscall.SizeofSockaddrInet4)
+	return nil
+}
+
+func (r *RawSockaddr) UpdateInet6x(sa *syscall.SockaddrInet6) error {
+	if sa.Port < 0 || sa.Port > 0xFFFF {
+		return syscall.EINVAL
+	}
+	raw := (*syscall.RawSockaddrInet6)(unsafe.Pointer(&r.Raw))
+	raw.Family = syscall.AF_INET6
+	p := (*[2]byte)(unsafe.Pointer(&raw.Port))
+	p[0] = byte(sa.Port >> 8)
+	p[1] = byte(sa.Port)
+	raw.Scope_id = sa.ZoneId
+	for i := 0; i < len(sa.Addr); i++ {
+		raw.Addr[i] = sa.Addr[i]
+	}
+	r.Len = Socklen(syscall.SizeofSockaddrInet6)
+	return nil
+}
+
+func (r *RawSockaddr) UpdateUnix(sa *syscall.SockaddrUnix) error {
+	raw := (*syscall.RawSockaddrUnix)(unsafe.Pointer(&r.Raw))
+	name := sa.Name
+	n := len(name)
+	if n >= len(raw.Path) {
+		return syscall.EINVAL
+	}
+	raw.Family = syscall.AF_UNIX
+	for i := 0; i < n; i++ {
+		raw.Path[i] = int8(name[i])
+	}
+	// length is family (uint16), name, NUL.
+	sl := Socklen(2)
+	if n > 0 {
+		sl += Socklen(n) + 1
+	}
+	if raw.Path[0] == '@' {
+		raw.Path[0] = 0
+		// Don't count trailing NUL for abstract address.
+		sl--
+	}
+
+	r.Len = Socklen(s)
+	return nil
+}
+
+func (r *RawSockaddr) UpdateLinklayer(sa *syscall.SockarrLinklayer) error {
+	if sa.Ifindex < 0 || sa.Ifindex > 0x7fffffff {
+		return syscall.EINVAL
+	}
+	raw := (*syscall.RawSockaddrLinklayer)(unsafe.Pointer(&r.Raw))
+	raw.Family = syscall.AF_PACKET
+	raw.Protocol = sa.Protocol
+	raw.Ifindex = int32(sa.Ifindex)
+	raw.Hatype = sa.Hatype
+	raw.Pkttype = sa.Pkttype
+	raw.Halen = sa.Halen
+	for i := 0; i < len(sa.Addr); i++ {
+		raw.Addr[i] = sa.Addr[i]
+	}
+	r.Len = Socklen(syscall.SizeofSockaddrLinklayer)
+	return nil
+}
+
+func (r *RawSockaddr) UpdateNetlink(sa *syscall.SockaddrNetlink) error {
+	raw := (*syscall.RawSockaddrNetlink)(unsafe.Pointer(&r.Raw))
+	raw.Family = syscall.AF_NETLINK
+	raw.Pad = sa.Pad
+	raw.Pid = sa.Pid
+	raw.Groups = sa.Groups
+	r.Len = syscall.SizeofSockaddrNetlink
+	return nil
+}
+
+func AnyToSockaddr(rsa *syscall.RawSockaddrAny) (syscall.Sockaddr, error) {
+	switch rsa.Addr.Family {
+	case syscall.AF_NETLINK:
+		pp := (*syscall.RawSockaddrNetlink)(unsafe.Pointer(rsa))
+		sa := new(syscall.SockaddrNetlink)
+		sa.Family = pp.Family
+		sa.Pad = pp.Pad
+		sa.Pid = pp.Pid
+		sa.Groups = pp.Groups
+		return sa, nil
+
+	case syscall.AF_PACKET:
+		pp := (*syscall.RawSockaddrLinklayer)(unsafe.Pointer(rsa))
+		sa := new(syscall.SockaddrLinklayer)
+		sa.Protocol = pp.Protocol
+		sa.Ifindex = int(pp.Ifindex)
+		sa.Hatype = pp.Hatype
+		sa.Pkttype = pp.Pkttype
+		sa.Halen = pp.Halen
+		for i := 0; i < len(sa.Addr); i++ {
+			sa.Addr[i] = pp.Addr[i]
+		}
+		return sa, nil
+
+	case syscall.AF_UNIX:
+		pp := (*syscall.RawSockaddrUnix)(unsafe.Pointer(rsa))
+		sa := new(syscall.SockaddrUnix)
+		if pp.Path[0] == 0 {
+			// "Abstract" Unix domain socket.
+			// Rewrite leading NUL as @ for textual display.
+			// (This is the standard convention.)
+			// Not friendly to overwrite in place,
+			// but the callers below don't care.
+			pp.Path[0] = '@'
+		}
+
+		// Assume path ends at NUL.
+		// This is not technically the Linux semantics for
+		// abstract Unix domain sockets--they are supposed
+		// to be uninterpreted fixed-size binary blobs--but
+		// everyone uses this convention.
+		n := 0
+		for n < len(pp.Path) && pp.Path[n] != 0 {
+			n++
+		}
+		bytes := (*[10000]byte)(unsafe.Pointer(&pp.Path[0]))[0:n]
+		sa.Name = string(bytes)
+		return sa, nil
+
+	case syscall.AF_INET:
+		pp := (*syscall.RawSockaddrInet4)(unsafe.Pointer(rsa))
+		sa := new(syscall.SockaddrInet4)
+		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
+		sa.Port = int(p[0])<<8 + int(p[1])
+		for i := 0; i < len(sa.Addr); i++ {
+			sa.Addr[i] = pp.Addr[i]
+		}
+		return sa, nil
+
+	case syscall.AF_INET6:
+		pp := (*syscall.RawSockaddrInet6)(unsafe.Pointer(rsa))
+		sa := new(syscall.SockaddrInet6)
+		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
+		sa.Port = int(p[0])<<8 + int(p[1])
+		sa.ZoneId = pp.Scope_id
+		for i := 0; i < len(sa.Addr); i++ {
+			sa.Addr[i] = pp.Addr[i]
+		}
+		return sa, nil
+	}
+	return nil, syscall.EAFNOSUPPORT
+}

sockaddr_windows.go

+// sockaddr syscall extensions
+package sockaddr
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+/*
+type SockaddrInet4 struct {
+	Port int
+	Addr [4]byte
+	raw  RawSockaddrInet4
+}
+*/
+
+func (r *RawSockaddr) Update(s *syscall.Sockaddr) error {
+
+	si4, ok := (*s).(*syscall.SockaddrInet4)
+	if ok {
+		return r.UpdateInet4(si4)
+	}
+
+	si6, ok := (*s).(*syscall.SockaddrInet6)
+	if ok {
+		return r.UpdateInet6(si6)
+	}
+
+	su, ok := (*s).(*syscall.SockaddrUnix)
+	if ok {
+		return r.UpdateUnix(su)
+	}
+
+	sdl, ok := (*s).(*syscall.SockaddrDatalink)
+	if ok {
+		return r.UpdateDatalink(sdl)
+	}
+
+	return fmt.Errorf("unknown sockaddr type")
+}
+
+func (r *RawSockaddr) UpdateInet4(sa *syscall.SockaddrInet4) error {
+	if sa.Port < 0 || sa.Port > 0xFFFF {
+		return syscall.EINVAL
+	}
+	raw := (*syscall.RawSockaddrInet4)(unsafe.Pointer(&r.Raw))
+	raw.Family = syscall.AF_INET
+	p := (*[2]byte)(unsafe.Pointer(&raw.Port))
+	p[0] = byte(sa.Port >> 8)
+	p[1] = byte(sa.Port)
+	for i := 0; i < len(sa.Addr); i++ {
+		raw.Addr[i] = sa.Addr[i]
+	}
+	raw.Len = uint(unsafe.Sizeof(sa.raw))
+	return nil
+}
+
+/*
+type SockaddrInet6 struct {
+	Port   int
+	ZoneId uint32
+	Addr   [16]byte
+	raw    RawSockaddrInet6
+}
+*/
+
+func (r *RawSockaddr) UpdateInet6(sa *syscall.SockaddrInet6) error {
+	if sa.Port < 0 || sa.Port > 0xFFFF {
+		return 0, 0, syscall.EINVAL
+	}
+	raw := (*syscall.RawSockaddrInet6)(unsafe.Pointer(&r.Raw))
+	raw.Family = syscall.AF_INET6
+	p := (*[2]byte)(unsafe.Pointer(&raw.Port))
+	p[0] = byte(sa.Port >> 8)
+	p[1] = byte(sa.Port)
+	raw.Scope_id = sa.ZoneId
+	for i := 0; i < len(sa.Addr); i++ {
+		raw.Addr[i] = sa.Addr[i]
+	}
+	raw.Len = uint(unsafe.Sizeof(sa.raw))
+	return nil
+}
+
+/*
+type SockaddrUnix struct {
+	Name string
+}
+*/
+func (r *RawSockaddr) UpdateUnix(sa *syscall.SockaddrUnix) error {
+	// TODO(brainman): implement SockaddrUnix.sockaddr()
+	return syscall.EWINDOWS
+}