syscall, net: Add Recvmsg and Sendmsg on Linux.

Working on issue 1101.

R=rsc
CC=golang-dev
https://golang.org/cl/2331044

src/pkg/net/fd.go

@@ -401,6 +401,42 @@ func (fd *netFD) ReadFrom(p []byte) (n int, sa syscall.Sockaddr, err os.Error) {
 	return
 }
 
+func (fd *netFD) ReadMsg(p []byte, oob []byte) (n, oobn, flags int, sa syscall.Sockaddr, err os.Error) {
+	if fd == nil || fd.sysfile == nil {
+		return 0, 0, 0, nil, os.EINVAL
+	}
+	fd.rio.Lock()
+	defer fd.rio.Unlock()
+	fd.incref()
+	defer fd.decref()
+	if fd.rdeadline_delta > 0 {
+		fd.rdeadline = pollserver.Now() + fd.rdeadline_delta
+	} else {
+		fd.rdeadline = 0
+	}
+	var oserr os.Error
+	for {
+		var errno int
+		n, oobn, flags, errno = syscall.Recvmsg(fd.sysfd, p, oob, sa, 0)
+		if errno == syscall.EAGAIN && fd.rdeadline >= 0 {
+			pollserver.WaitRead(fd)
+			continue
+		}
+		if errno != 0 {
+			oserr = os.Errno(errno)
+		}
+		if n == 0 {
+			oserr = os.EOF
+		}
+		break
+	}
+	if oserr != nil {
+		err = &OpError{"read", fd.net, fd.laddr, oserr}
+		return
+	}
+	return
+}
+
 func (fd *netFD) Write(p []byte) (n int, err os.Error) {
 	if fd == nil {
 		return 0, os.EINVAL
@@ -481,6 +517,41 @@ func (fd *netFD) WriteTo(p []byte, sa syscall.Sockaddr) (n int, err os.Error) {
 	return
 }
 
+func (fd *netFD) WriteMsg(p []byte, oob []byte, sa syscall.Sockaddr) (n int, oobn int, err os.Error) {
+	if fd == nil || fd.sysfile == nil {
+		return 0, 0, os.EINVAL
+	}
+	fd.wio.Lock()
+	defer fd.wio.Unlock()
+	fd.incref()
+	defer fd.decref()
+	if fd.wdeadline_delta > 0 {
+		fd.wdeadline = pollserver.Now() + fd.wdeadline_delta
+	} else {
+		fd.wdeadline = 0
+	}
+	var oserr os.Error
+	for {
+		var errno int
+		errno = syscall.Sendmsg(fd.sysfd, p, oob, sa, 0)
+		if errno == syscall.EAGAIN && fd.wdeadline >= 0 {
+			pollserver.WaitWrite(fd)
+			continue
+		}
+		if errno != 0 {
+			oserr = os.Errno(errno)
+		}
+		break
+	}
+	if oserr == nil {
+		n = len(p)
+		oobn = len(oob)
+	} else {
+		err = &OpError{"write", fd.net, fd.raddr, oserr}
+	}
+	return
+}
+
 func (fd *netFD) accept(toAddr func(syscall.Sockaddr) Addr) (nfd *netFD, err os.Error) {
 	if fd == nil || fd.sysfile == nil {
 		return nil, os.EINVAL

src/pkg/net/fd_windows.go

@@ -445,3 +445,11 @@ func (fd *netFD) dup() (f *os.File, err os.Error) {
 	// TODO: Implement this
 	return nil, os.NewSyscallError("dup", syscall.EWINDOWS)
 }
+
+func (fd *netFD) ReadMsg(p []byte, oob []byte) (n, oobn, flags int, sa syscall.Sockaddr, err os.Error) {
+	return 0, 0, 0, nil, os.EAFNOSUPPORT
+}
+
+func (fd *netFD) WriteMsg(p []byte, oob []byte, sa syscall.Sockaddr) (n int, oobn int, err os.Error) {
+	return 0, 0, os.EAFNOSUPPORT
+}

src/pkg/net/unixsock.go

@@ -277,6 +277,32 @@ func (c *UnixConn) WriteTo(b []byte, addr Addr) (n int, err os.Error) {
 	return c.WriteToUnix(b, a)
 }
 
+func (c *UnixConn) ReadMsgUnix(b, oob []byte) (n, oobn, flags int, addr *UnixAddr, err os.Error) {
+	if !c.ok() {
+		return 0, 0, 0, nil, os.EINVAL
+	}
+	n, oobn, flags, sa, err := c.fd.ReadMsg(b, oob)
+	switch sa := sa.(type) {
+	case *syscall.SockaddrUnix:
+		addr = &UnixAddr{sa.Name, c.fd.proto == syscall.SOCK_DGRAM}
+	}
+	return
+}
+
+func (c *UnixConn) WriteMsgUnix(b, oob []byte, addr *UnixAddr) (n, oobn int, err os.Error) {
+	if !c.ok() {
+		return 0, 0, os.EINVAL
+	}
+	if addr != nil {
+		if addr.Datagram != (c.fd.proto == syscall.SOCK_DGRAM) {
+			return 0, 0, os.EAFNOSUPPORT
+		}
+		sa := &syscall.SockaddrUnix{Name: addr.Name}
+		return c.fd.WriteMsg(b, oob, sa)
+	}
+	return c.fd.WriteMsg(b, oob, nil)
+}
+
 // File returns a copy of the underlying os.File, set to blocking mode.
 // It is the caller's responsibility to close f when finished.
 // Closing c does not affect f, and closing f does not affect c.

src/pkg/syscall/mkerrors.sh

@@ -25,6 +25,8 @@ includes_Linux='
 #include <sys/epoll.h>
 #include <sys/inotify.h>
 #include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
 #include <linux/ptrace.h>
 #include <linux/wait.h>
 #include <netpacket/packet.h>
@@ -84,11 +86,13 @@ done
 		
 		$2 ~ /^E([ABCD]X|[BIS]P|[SD]I|S|FL)$/ {next}  # 386 registers
 		$2 ~ /^(SIGEV_|SIGSTKSZ|SIGRT(MIN|MAX))/ {next}
+		$2 ~ /^(SCM_SRCRT)$/ {next}
+		$2 ~ /^(MAP_FAILED)$/ {next}
 
 		$2 ~ /^E[A-Z0-9_]+$/ ||
 		$2 ~ /^SIG[^_]/ ||
 		$2 ~ /^IN_/ ||
-		$2 ~ /^(AF|SOCK|SO|SOL|IPPROTO|IP|IPV6|TCP|EVFILT|EV|SHUT|PROT|MAP|PACKET)_/ ||
+		$2 ~ /^(AF|SOCK|SO|SOL|IPPROTO|IP|IPV6|TCP|EVFILT|EV|SHUT|PROT|MAP|PACKET|MSG|SCM)_/ ||
 		$2 == "SOMAXCONN" ||
 		$2 == "NAME_MAX" ||
 		$2 ~ /^(O|F|FD|NAME|S|PTRACE)_/ ||

src/pkg/syscall/syscall_bsd.go

@@ -485,6 +485,13 @@ func Futimes(fd int, tv []Timeval) (errno int) {
 
 //sys	fcntl(fd int, cmd int, arg int) (val int, errno int)
 
+func Recvmsg(fd int, p, oob []byte, from Sockaddr, flags int) (n, oobn int, recvflags int, errno int) {
+	return 0, 0, 0, EAFNOSUPPORT
+}
+
+func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (errno int) {
+	return EAFNOSUPPORT
+}
 
 // TODO: wrap
 //	Acct(name nil-string) (errno int)
@@ -495,5 +502,3 @@ func Futimes(fd int, tv []Timeval) (errno int) {
 //	Msync(addr *byte, len int, flags int) (errno int)
 //	Munmap(addr *byte, len int) (errno int)
 //	Ptrace(req int, pid int, addr uintptr, data int) (ret uintptr, errno int)
-//	Recvmsg(s int, msg *Msghdr, flags int) (n int, errno int)
-//	Sendmsg(s int, msg *Msghdr, flags int) (n int, errno int)

src/pkg/syscall/syscall_linux.go

@@ -447,6 +447,72 @@ func Sendto(fd int, p []byte, flags int, to Sockaddr) (errno int) {
 	return sendto(fd, p, flags, ptr, n)
 }
 
+func Recvmsg(fd int, p, oob []byte, from Sockaddr, flags int) (n, oobn int, recvflags int, errno int) {
+	var msg Msghdr
+	var rsa RawSockaddrAny
+	msg.Name = (*byte)(unsafe.Pointer(&rsa))
+	msg.Namelen = uint32(SizeofSockaddrAny)
+	var iov Iovec
+	if len(p) > 0 {
+		iov.Base = (*byte)(unsafe.Pointer(&p[0]))
+		iov.SetLen(len(p))
+	}
+	var dummy byte
+	if len(oob) > 0 {
+		// receive at least one normal byte
+		if len(p) == 0 {
+			iov.Base = &dummy
+			iov.SetLen(1)
+		}
+		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
+		msg.SetControllen(len(oob))
+	}
+	msg.Iov = &iov
+	msg.Iovlen = 1
+	if n, errno = recvmsg(fd, &msg, flags); errno != 0 {
+		return
+	}
+	oobn = int(msg.Controllen)
+	recvflags = int(msg.Flags)
+	return
+}
+
+func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (errno int) {
+	var ptr uintptr
+	var nsock _Socklen
+	if to != nil {
+		var err int
+		ptr, nsock, err = to.sockaddr()
+		if err != 0 {
+			return err
+		}
+	}
+	var msg Msghdr
+	msg.Name = (*byte)(unsafe.Pointer(ptr))
+	msg.Namelen = uint32(nsock)
+	var iov Iovec
+	if len(p) > 0 {
+		iov.Base = (*byte)(unsafe.Pointer(&p[0]))
+		iov.SetLen(len(p))
+	}
+	var dummy byte
+	if len(oob) > 0 {
+		// send at least one normal byte
+		if len(p) == 0 {
+			iov.Base = &dummy
+			iov.SetLen(1)
+		}
+		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
+		msg.SetControllen(len(oob))
+	}
+	msg.Iov = &iov
+	msg.Iovlen = 1
+	if errno = sendmsg(fd, &msg, flags); errno != 0 {
+		return
+	}
+	return
+}
+
 // BindToDevice binds the socket associated with fd to device.
 func BindToDevice(fd int, device string) (errno int) {
 	return SetsockoptString(fd, SOL_SOCKET, SO_BINDTODEVICE, device)
@@ -592,8 +658,6 @@ func PtraceDetach(pid int) (errno int) { return ptrace(PTRACE_DETACH, pid, 0, 0)
 
 // Sendto
 // Recvfrom
-// Sendmsg
-// Recvmsg
 // Socketpair
 // Getsockopt
 

src/pkg/syscall/syscall_linux_386.go

@@ -151,6 +151,16 @@ func sendto(s int, p []byte, flags int, to uintptr, addrlen _Socklen) (errno int
 	return
 }
 
+func recvmsg(s int, msg *Msghdr, flags int) (n int, errno int) {
+	n, errno = socketcall(_RECVMSG, uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags), 0, 0, 0)
+	return
+}
+
+func sendmsg(s int, msg *Msghdr, flags int) (errno int) {
+	_, errno = socketcall(_SENDMSG, uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags), 0, 0, 0)
+	return
+}
+
 func Listen(s int, n int) (errno int) {
 	_, errno = socketcall(_LISTEN, uintptr(s), uintptr(n), 0, 0, 0, 0)
 	return
@@ -176,3 +186,15 @@ func Statfs(path string, buf *Statfs_t) (errno int) {
 func (r *PtraceRegs) PC() uint64 { return uint64(uint32(r.Eip)) }
 
 func (r *PtraceRegs) SetPC(pc uint64) { r.Eip = int32(pc) }
+
+func (iov *Iovec) SetLen(length int) {
+	iov.Len = uint32(length)
+}
+
+func (msghdr *Msghdr) SetControllen(length int) {
+	msghdr.Controllen = uint32(length)
+}
+
+func (cmsg *Cmsghdr) SetLen(length int) {
+	cmsg.Len = uint32(length)
+}

src/pkg/syscall/syscall_linux_amd64.go

@@ -46,6 +46,8 @@ package syscall
 //sys	getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (errno int)
 //sys	recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, errno int)
 //sys	sendto(s int, buf []byte, flags int, to uintptr, addrlen _Socklen) (errno int)
+//sys	recvmsg(s int, msg *Msghdr, flags int) (n int, errno int)
+//sys	sendmsg(s int, msg *Msghdr, flags int) (errno int)
 
 func Getpagesize() int { return 4096 }
 
@@ -72,3 +74,15 @@ func NsecToTimeval(nsec int64) (tv Timeval) {
 func (r *PtraceRegs) PC() uint64 { return r.Rip }
 
 func (r *PtraceRegs) SetPC(pc uint64) { r.Rip = pc }
+
+func (iov *Iovec) SetLen(length int) {
+	iov.Len = uint64(length)
+}
+
+func (msghdr *Msghdr) SetControllen(length int) {
+	msghdr.Controllen = uint64(length)
+}
+
+func (cmsg *Cmsghdr) SetLen(length int) {
+	cmsg.Len = uint64(length)
+}

src/pkg/syscall/zerrors_linux_386.go

@@ -385,6 +385,40 @@ const (
 	IP_TOS                           = 0x1
 	IP_TTL                           = 0x2
 	IP_UNBLOCK_SOURCE                = 0x25
+	MAP_32BIT                        = 0x40
+	MAP_ANON                         = 0x20
+	MAP_ANONYMOUS                    = 0x20
+	MAP_DENYWRITE                    = 0x800
+	MAP_EXECUTABLE                   = 0x1000
+	MAP_FILE                         = 0
+	MAP_FIXED                        = 0x10
+	MAP_GROWSDOWN                    = 0x100
+	MAP_LOCKED                       = 0x2000
+	MAP_NONBLOCK                     = 0x10000
+	MAP_NORESERVE                    = 0x4000
+	MAP_POPULATE                     = 0x8000
+	MAP_PRIVATE                      = 0x2
+	MAP_SHARED                       = 0x1
+	MAP_STACK                        = 0x20000
+	MAP_TYPE                         = 0xf
+	MSG_CMSG_CLOEXEC                 = 0x40000000
+	MSG_CONFIRM                      = 0x800
+	MSG_CTRUNC                       = 0x8
+	MSG_DONTROUTE                    = 0x4
+	MSG_DONTWAIT                     = 0x40
+	MSG_EOR                          = 0x80
+	MSG_ERRQUEUE                     = 0x2000
+	MSG_FIN                          = 0x200
+	MSG_MORE                         = 0x8000
+	MSG_NOSIGNAL                     = 0x4000
+	MSG_OOB                          = 0x1
+	MSG_PEEK                         = 0x2
+	MSG_PROXY                        = 0x10
+	MSG_RST                          = 0x1000
+	MSG_SYN                          = 0x400
+	MSG_TRUNC                        = 0x20
+	MSG_TRYHARD                      = 0x4
+	MSG_WAITALL                      = 0x100
 	NAME_MAX                         = 0xff
 	O_ACCMODE                        = 0x3
 	O_APPEND                         = 0x400
@@ -423,6 +457,12 @@ const (
 	PACKET_RECV_OUTPUT               = 0x3
 	PACKET_RX_RING                   = 0x5
 	PACKET_STATISTICS                = 0x6
+	PROT_EXEC                        = 0x4
+	PROT_GROWSDOWN                   = 0x1000000
+	PROT_GROWSUP                     = 0x2000000
+	PROT_NONE                        = 0
+	PROT_READ                        = 0x1
+	PROT_WRITE                       = 0x2
 	PTRACE_ATTACH                    = 0x10
 	PTRACE_BTS_CLEAR                 = 0x2c
 	PTRACE_BTS_CONFIG                = 0x28
@@ -476,6 +516,11 @@ const (
 	PTRACE_SYSEMU                    = 0x1f
 	PTRACE_SYSEMU_SINGLESTEP         = 0x20
 	PTRACE_TRACEME                   = 0
+	SCM_CREDENTIALS                  = 0x2
+	SCM_RIGHTS                       = 0x1
+	SCM_TIMESTAMP                    = 0x1d
+	SCM_TIMESTAMPING                 = 0x25
+	SCM_TIMESTAMPNS                  = 0x23
 	SHUT_RD                          = 0
 	SHUT_RDWR                        = 0x2
 	SHUT_WR                          = 0x1

src/pkg/syscall/zerrors_linux_amd64.go

@@ -385,6 +385,40 @@ const (
 	IP_TOS                           = 0x1
 	IP_TTL                           = 0x2
 	IP_UNBLOCK_SOURCE                = 0x25
+	MAP_32BIT                        = 0x40
+	MAP_ANON                         = 0x20
+	MAP_ANONYMOUS                    = 0x20
+	MAP_DENYWRITE                    = 0x800
+	MAP_EXECUTABLE                   = 0x1000
+	MAP_FILE                         = 0
+	MAP_FIXED                        = 0x10
+	MAP_GROWSDOWN                    = 0x100
+	MAP_LOCKED                       = 0x2000
+	MAP_NONBLOCK                     = 0x10000
+	MAP_NORESERVE                    = 0x4000
+	MAP_POPULATE                     = 0x8000
+	MAP_PRIVATE                      = 0x2
+	MAP_SHARED                       = 0x1
+	MAP_STACK                        = 0x20000
+	MAP_TYPE                         = 0xf
+	MSG_CMSG_CLOEXEC                 = 0x40000000
+	MSG_CONFIRM                      = 0x800
+	MSG_CTRUNC                       = 0x8
+	MSG_DONTROUTE                    = 0x4
+	MSG_DONTWAIT                     = 0x40
+	MSG_EOR                          = 0x80
+	MSG_ERRQUEUE                     = 0x2000
+	MSG_FIN                          = 0x200
+	MSG_MORE                         = 0x8000
+	MSG_NOSIGNAL                     = 0x4000
+	MSG_OOB                          = 0x1
+	MSG_PEEK                         = 0x2
+	MSG_PROXY                        = 0x10
+	MSG_RST                          = 0x1000
+	MSG_SYN                          = 0x400
+	MSG_TRUNC                        = 0x20
+	MSG_TRYHARD                      = 0x4
+	MSG_WAITALL                      = 0x100
 	NAME_MAX                         = 0xff
 	O_ACCMODE                        = 0x3
 	O_APPEND                         = 0x400
@@ -423,6 +457,12 @@ const (
 	PACKET_RECV_OUTPUT               = 0x3
 	PACKET_RX_RING                   = 0x5
 	PACKET_STATISTICS                = 0x6
+	PROT_EXEC                        = 0x4
+	PROT_GROWSDOWN                   = 0x1000000
+	PROT_GROWSUP                     = 0x2000000
+	PROT_NONE                        = 0
+	PROT_READ                        = 0x1
+	PROT_WRITE                       = 0x2
 	PTRACE_ARCH_PRCTL                = 0x1e
 	PTRACE_ATTACH                    = 0x10
 	PTRACE_BTS_CLEAR                 = 0x2c
@@ -477,6 +517,11 @@ const (
 	PTRACE_SYSEMU                    = 0x1f
 	PTRACE_SYSEMU_SINGLESTEP         = 0x20
 	PTRACE_TRACEME                   = 0
+	SCM_CREDENTIALS                  = 0x2
+	SCM_RIGHTS                       = 0x1
+	SCM_TIMESTAMP                    = 0x1d
+	SCM_TIMESTAMPING                 = 0x25
+	SCM_TIMESTAMPNS                  = 0x23
 	SHUT_RD                          = 0
 	SHUT_RDWR                        = 0x2
 	SHUT_WR                          = 0x1

src/pkg/syscall/zsyscall_linux_amd64.go

@@ -1089,3 +1089,20 @@ func sendto(s int, buf []byte, flags int, to uintptr, addrlen _Socklen) (errno i
 	errno = int(e1)
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func recvmsg(s int, msg *Msghdr, flags int) (n int, errno int) {
+	r0, _, e1 := Syscall(SYS_RECVMSG, uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
+	n = int(r0)
+	errno = int(e1)
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func sendmsg(s int, msg *Msghdr, flags int) (errno int) {
+	_, _, e1 := Syscall(SYS_SENDMSG, uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
+	errno = int(e1)
+	return
+}