Implement stubs for msgsnd(2) and msgrcv(2).

Add support for msgsnd and msgrcv and enable syscall tests.

Updates #135

3 files changed, 87 insertions, 4 deletions

diff --git a/pkg/sentry/syscalls/linux/BUILD b/pkg/sentry/syscalls/linux/BUILD
index ccccce6a9..b5a371d9a 100644
--- a/pkg/sentry/syscalls/linux/BUILD
+++ b/pkg/sentry/syscalls/linux/BUILD
@@ -86,6 +86,7 @@ go_library(
         "//pkg/sentry/kernel/eventfd",
         "//pkg/sentry/kernel/fasync",
         "//pkg/sentry/kernel/ipc",
+        "//pkg/sentry/kernel/msgqueue",
         "//pkg/sentry/kernel/pipe",
         "//pkg/sentry/kernel/sched",
         "//pkg/sentry/kernel/shm",
diff --git a/pkg/sentry/syscalls/linux/linux64.go b/pkg/sentry/syscalls/linux/linux64.go
index 6f44d767b..6a5a30516 100644
--- a/pkg/sentry/syscalls/linux/linux64.go
+++ b/pkg/sentry/syscalls/linux/linux64.go
@@ -122,8 +122,8 @@ var AMD64 = &kernel.SyscallTable{
 		66:  syscalls.Supported("semctl", Semctl),
 		67:  syscalls.Supported("shmdt", Shmdt),
 		68:  syscalls.Supported("msgget", Msgget),
-		69:  syscalls.ErrorWithEvent("msgsnd", linuxerr.ENOSYS, "", []string{"gvisor.dev/issue/135"}), // TODO(b/29354921)
-		70:  syscalls.ErrorWithEvent("msgrcv", linuxerr.ENOSYS, "", []string{"gvisor.dev/issue/135"}), // TODO(b/29354921)
+		69:  syscalls.Supported("msgsnd", Msgsnd),
+		70:  syscalls.PartiallySupported("msgrcv", Msgrcv, "Doesn't support MSG_COPY option.", []string{"gvisor.dev/issue/135"}),
 		71:  syscalls.PartiallySupported("msgctl", Msgctl, "Only supports IPC_RMID option.", []string{"gvisor.dev/issue/135"}),
 		72:  syscalls.PartiallySupported("fcntl", Fcntl, "Not all options are supported.", nil),
 		73:  syscalls.PartiallySupported("flock", Flock, "Locks are held within the sandbox only.", nil),
@@ -618,8 +618,8 @@ var ARM64 = &kernel.SyscallTable{
 		185: syscalls.ErrorWithEvent("mq_getsetattr", syserror.ENOSYS, "", []string{"gvisor.dev/issue/136"}),   // TODO(b/29354921)
 		186: syscalls.Supported("msgget", Msgget),
 		187: syscalls.PartiallySupported("msgctl", Msgctl, "Only supports IPC_RMID option.", []string{"gvisor.dev/issue/135"}),
-		188: syscalls.ErrorWithEvent("msgrcv", linuxerr.ENOSYS, "", []string{"gvisor.dev/issue/135"}), // TODO(b/29354921)
-		189: syscalls.ErrorWithEvent("msgsnd", linuxerr.ENOSYS, "", []string{"gvisor.dev/issue/135"}), // TODO(b/29354921)
+		188: syscalls.PartiallySupported("msgrcv", Msgrcv, "Doesn't support MSG_COPY option.", []string{"gvisor.dev/issue/135"}),
+		189: syscalls.Supported("msgsnd", Msgsnd),
 		190: syscalls.Supported("semget", Semget),
 		191: syscalls.Supported("semctl", Semctl),
 		192: syscalls.Supported("semtimedop", Semtimedop),
diff --git a/pkg/sentry/syscalls/linux/sys_msgqueue.go b/pkg/sentry/syscalls/linux/sys_msgqueue.go
index 3476e218d..d61777d02 100644
--- a/pkg/sentry/syscalls/linux/sys_msgqueue.go
+++ b/pkg/sentry/syscalls/linux/sys_msgqueue.go
@@ -17,10 +17,12 @@ package linux
 import (
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/errors/linuxerr"
+	"gvisor.dev/gvisor/pkg/marshal/primitive"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/ipc"
+	"gvisor.dev/gvisor/pkg/sentry/kernel/msgqueue"
 )
 
 // Msgget implements msgget(2).
@@ -41,6 +43,86 @@ func Msgget(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
 	return uintptr(queue.ID()), nil, nil
 }
 
+// Msgsnd implements msgsnd(2).
+func Msgsnd(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	id := ipc.ID(args[0].Int())
+	msgAddr := args[1].Pointer()
+	size := args[2].Int64()
+	flag := args[3].Int()
+
+	if size < 0 || size > linux.MSGMAX {
+		return 0, nil, linuxerr.EINVAL
+	}
+
+	wait := flag&linux.IPC_NOWAIT != linux.IPC_NOWAIT
+	pid := int32(t.ThreadGroup().ID())
+
+	buf := linux.MsgBuf{
+		Text: make([]byte, size),
+	}
+	if _, err := buf.CopyIn(t, msgAddr); err != nil {
+		return 0, nil, err
+	}
+
+	queue, err := t.IPCNamespace().MsgqueueRegistry().FindByID(id)
+	if err != nil {
+		return 0, nil, err
+	}
+
+	msg := msgqueue.Message{
+		Type: int64(buf.Type),
+		Text: buf.Text,
+		Size: uint64(size),
+	}
+	return 0, nil, queue.Send(t, msg, t, wait, pid)
+}
+
+// Msgrcv implements msgrcv(2).
+func Msgrcv(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	id := ipc.ID(args[0].Int())
+	msgAddr := args[1].Pointer()
+	size := args[2].Int64()
+	mType := args[3].Int64()
+	flag := args[4].Int()
+
+	wait := flag&linux.IPC_NOWAIT != linux.IPC_NOWAIT
+	except := flag&linux.MSG_EXCEPT == linux.MSG_EXCEPT
+	truncate := flag&linux.MSG_NOERROR == linux.MSG_NOERROR
+
+	msgCopy := flag&linux.MSG_COPY == linux.MSG_COPY
+
+	msg, err := receive(t, id, mType, size, msgCopy, wait, truncate, except)
+	if err != nil {
+		return 0, nil, err
+	}
+
+	buf := linux.MsgBuf{
+		Type: primitive.Int64(msg.Type),
+		Text: msg.Text,
+	}
+	if _, err := buf.CopyOut(t, msgAddr); err != nil {
+		return 0, nil, err
+	}
+	return uintptr(msg.Size), nil, nil
+}
+
+// receive returns a message from the queue with the given ID. If msgCopy is
+// true, a message is copied from the queue without being removed. Otherwise,
+// a message is removed from the queue and returned.
+func receive(t *kernel.Task, id ipc.ID, mType int64, maxSize int64, msgCopy, wait, truncate, except bool) (*msgqueue.Message, error) {
+	pid := int32(t.ThreadGroup().ID())
+
+	queue, err := t.IPCNamespace().MsgqueueRegistry().FindByID(id)
+	if err != nil {
+		return nil, err
+	}
+
+	if msgCopy {
+		return queue.Copy()
+	}
+	return queue.Receive(t, t, mType, maxSize, wait, truncate, except, pid)
+}
+
 // Msgctl implements msgctl(2).
 func Msgctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
 	id := ipc.ID(args[0].Int())