[release-branch.go1.12] syscall: on AIX use nsendmsg and nrecvmsg, define SockaddrDatalink

This commit changes sendmsg, recvmsg to use nsendmsg, nrecvmsg on AIX.
These syscalls support the new msghdr structure (with Control
and Controllen) which is needed for golang.org/x/net.
Also define SockaddrDataLink.

Fixes #33982

Change-Id: I233fbd24f9eb86648e0d4d50c2b56da3626292d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/170537
Run-TryBot: Ian Lance Taylor <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Tobias Klauser <[email protected]>
(cherry picked from commit e014184)
Reviewed-on: https://go-review.googlesource.com/c/go/+/193608
Reviewed-by: Brad Fitzpatrick <[email protected]>

Author: Clément Chigot

src/syscall/syscall_aix.go

@@ -217,8 +217,11 @@ func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int,
 //sys	recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error)
 //sys	sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (err error)
 //sys	Shutdown(s int, how int) (err error)
-//sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error)
-//sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error)
+
+// In order to use msghdr structure with Control, Controllen in golang.org/x/net,
+// nrecvmsg and nsendmsg must be used.
+//sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error) = nrecvmsg
+//sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error) = nsendmsg
 
 func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
 	if sa.Port < 0 || sa.Port > 0xFFFF {
@@ -434,6 +437,18 @@ func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, error) {
 	return nil, EAFNOSUPPORT
 }
 
+type SockaddrDatalink struct {
+	Len    uint8
+	Family uint8
+	Index  uint16
+	Type   uint8
+	Nlen   uint8
+	Alen   uint8
+	Slen   uint8
+	Data   [120]uint8
+	raw    RawSockaddrDatalink
+}
+
 /*
  * Wait
  */

src/syscall/types_aix.go

@@ -23,6 +23,7 @@ package syscall
 #include <sys/statfs.h>
 
 #include <net/if.h>
+#include <net/if_dl.h>
 #include <netinet/in.h>
 #include <netinet/icmp6.h>
 
@@ -112,6 +113,8 @@ type RawSockaddrInet6 C.struct_sockaddr_in6
 
 type RawSockaddrUnix C.struct_sockaddr_un
 
+type RawSockaddrDatalink C.struct_sockaddr_dl
+
 type RawSockaddr C.struct_sockaddr
 
 type RawSockaddrAny C.struct_sockaddr_any
@@ -133,16 +136,17 @@ type Linger C.struct_linger
 type Msghdr C.struct_msghdr
 
 const (
-	SizeofSockaddrInet4 = C.sizeof_struct_sockaddr_in
-	SizeofSockaddrInet6 = C.sizeof_struct_sockaddr_in6
-	SizeofSockaddrAny   = C.sizeof_struct_sockaddr_any
-	SizeofSockaddrUnix  = C.sizeof_struct_sockaddr_un
-	SizeofLinger        = C.sizeof_struct_linger
-	SizeofIPMreq        = C.sizeof_struct_ip_mreq
-	SizeofIPv6Mreq      = C.sizeof_struct_ipv6_mreq
-	SizeofMsghdr        = C.sizeof_struct_msghdr
-	SizeofCmsghdr       = C.sizeof_struct_cmsghdr
-	SizeofICMPv6Filter  = C.sizeof_struct_icmp6_filter
+	SizeofSockaddrInet4    = C.sizeof_struct_sockaddr_in
+	SizeofSockaddrInet6    = C.sizeof_struct_sockaddr_in6
+	SizeofSockaddrAny      = C.sizeof_struct_sockaddr_any
+	SizeofSockaddrUnix     = C.sizeof_struct_sockaddr_un
+	SizeofSockaddrDatalink = C.sizeof_struct_sockaddr_dl
+	SizeofLinger           = C.sizeof_struct_linger
+	SizeofIPMreq           = C.sizeof_struct_ip_mreq
+	SizeofIPv6Mreq         = C.sizeof_struct_ipv6_mreq
+	SizeofMsghdr           = C.sizeof_struct_msghdr
+	SizeofCmsghdr          = C.sizeof_struct_cmsghdr
+	SizeofICMPv6Filter     = C.sizeof_struct_icmp6_filter
 )
 
 // Ptrace requests