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-rw-r--r--pkg/sentry/kernel/msgqueue/msgqueue.go278
-rw-r--r--pkg/sentry/kernel/msgqueue/msgqueue_state_autogen.go18
-rw-r--r--pkg/sentry/syscalls/linux/linux64.go8
-rw-r--r--pkg/sentry/syscalls/linux/sys_msgqueue.go85
4 files changed, 370 insertions, 19 deletions
diff --git a/pkg/sentry/kernel/msgqueue/msgqueue.go b/pkg/sentry/kernel/msgqueue/msgqueue.go
index 3ce926950..c111297d7 100644
--- a/pkg/sentry/kernel/msgqueue/msgqueue.go
+++ b/pkg/sentry/kernel/msgqueue/msgqueue.go
@@ -119,14 +119,21 @@ type Queue struct {
type Message struct {
msgEntry
- // mType is an integer representing the type of the sent message.
- mType int64
+ // Type is an integer representing the type of the sent message.
+ Type int64
- // mText is an untyped block of memory.
- mText []byte
+ // Text is an untyped block of memory.
+ Text []byte
- // mSize is the size of mText.
- mSize uint64
+ // Size is the size of Text.
+ Size uint64
+}
+
+// Blocker is used for blocking Queue.Send, and Queue.Receive calls that serves
+// as an abstracted version of kernel.Task. kernel.Task is not directly used to
+// prevent circular dependencies.
+type Blocker interface {
+ Block(C <-chan struct{}) error
}
// FindOrCreate creates a new message queue or returns an existing one. See
@@ -186,6 +193,265 @@ func (r *Registry) Remove(id ipc.ID, creds *auth.Credentials) error {
return nil
}
+// FindByID returns the queue with the specified ID and an error if the ID
+// doesn't exist.
+func (r *Registry) FindByID(id ipc.ID) (*Queue, error) {
+ r.mu.Lock()
+ defer r.mu.Unlock()
+
+ mech := r.reg.FindByID(id)
+ if mech == nil {
+ return nil, linuxerr.EINVAL
+ }
+ return mech.(*Queue), nil
+}
+
+// Send appends a message to the message queue, and returns an error if sending
+// fails. See msgsnd(2).
+func (q *Queue) Send(ctx context.Context, m Message, b Blocker, wait bool, pid int32) (err error) {
+ // Try to perform a non-blocking send using queue.append. If EWOULDBLOCK
+ // is returned, start the blocking procedure. Otherwise, return normally.
+ creds := auth.CredentialsFromContext(ctx)
+ if err := q.append(ctx, m, creds, pid); err != linuxerr.EWOULDBLOCK {
+ return err
+ }
+
+ if !wait {
+ return linuxerr.EAGAIN
+ }
+
+ e, ch := waiter.NewChannelEntry(nil)
+ q.senders.EventRegister(&e, waiter.EventOut)
+
+ for {
+ if err = q.append(ctx, m, creds, pid); err != linuxerr.EWOULDBLOCK {
+ break
+ }
+ b.Block(ch)
+ }
+
+ q.senders.EventUnregister(&e)
+ return err
+}
+
+// append appends a message to the queue's message list and notifies waiting
+// receivers that a message has been inserted. It returns an error if adding
+// the message would cause the queue to exceed its maximum capacity, which can
+// be used as a signal to block the task. Other errors should be returned as is.
+func (q *Queue) append(ctx context.Context, m Message, creds *auth.Credentials, pid int32) error {
+ if m.Type <= 0 {
+ return linuxerr.EINVAL
+ }
+
+ q.mu.Lock()
+ defer q.mu.Unlock()
+
+ if !q.obj.CheckPermissions(creds, fs.PermMask{Write: true}) {
+ // The calling process does not have write permission on the message
+ // queue, and does not have the CAP_IPC_OWNER capability in the user
+ // namespace that governs its IPC namespace.
+ return linuxerr.EACCES
+ }
+
+ // Queue was removed while the process was waiting.
+ if q.dead {
+ return linuxerr.EIDRM
+ }
+
+ // Check if sufficient space is available (the queue isn't full.) From
+ // the man pages:
+ //
+ // "A message queue is considered to be full if either of the following
+ // conditions is true:
+ //
+ // • Adding a new message to the queue would cause the total number
+ // of bytes in the queue to exceed the queue's maximum size (the
+ // msg_qbytes field).
+ //
+ // • Adding another message to the queue would cause the total
+ // number of messages in the queue to exceed the queue's maximum
+ // size (the msg_qbytes field). This check is necessary to
+ // prevent an unlimited number of zero-length messages being
+ // placed on the queue. Although such messages contain no data,
+ // they nevertheless consume (locked) kernel memory."
+ //
+ // The msg_qbytes field in our implementation is q.maxBytes.
+ if m.Size+q.byteCount > q.maxBytes || q.messageCount+1 > q.maxBytes {
+ return linuxerr.EWOULDBLOCK
+ }
+
+ // Copy the message into the queue.
+ q.messages.PushBack(&m)
+
+ q.byteCount += m.Size
+ q.messageCount++
+ q.sendPID = pid
+ q.sendTime = ktime.NowFromContext(ctx)
+
+ // Notify receivers about the new message.
+ q.receivers.Notify(waiter.EventIn)
+
+ return nil
+}
+
+// Receive removes a message from the queue and returns it. See msgrcv(2).
+func (q *Queue) Receive(ctx context.Context, b Blocker, mType int64, maxSize int64, wait, truncate, except bool, pid int32) (msg *Message, err error) {
+ if maxSize < 0 || maxSize > maxMessageBytes {
+ return nil, linuxerr.EINVAL
+ }
+ max := uint64(maxSize)
+
+ // Try to perform a non-blocking receive using queue.pop. If EWOULDBLOCK
+ // is returned, start the blocking procedure. Otherwise, return normally.
+ creds := auth.CredentialsFromContext(ctx)
+ if msg, err := q.pop(ctx, creds, mType, max, truncate, except, pid); err != linuxerr.EWOULDBLOCK {
+ return msg, err
+ }
+
+ if !wait {
+ return nil, linuxerr.ENOMSG
+ }
+
+ e, ch := waiter.NewChannelEntry(nil)
+ q.receivers.EventRegister(&e, waiter.EventIn)
+
+ for {
+ if msg, err = q.pop(ctx, creds, mType, max, truncate, except, pid); err != linuxerr.EWOULDBLOCK {
+ break
+ }
+ b.Block(ch)
+ }
+ q.receivers.EventUnregister(&e)
+ return msg, err
+}
+
+// pop pops the first message from the queue that matches the given type. It
+// returns an error for all the cases specified in msgrcv(2). If the queue is
+// empty or no message of the specified type is available, a EWOULDBLOCK error
+// is returned, which can then be used as a signal to block the process or fail.
+func (q *Queue) pop(ctx context.Context, creds *auth.Credentials, mType int64, maxSize uint64, truncate, except bool, pid int32) (msg *Message, _ error) {
+ q.mu.Lock()
+ defer q.mu.Unlock()
+
+ if !q.obj.CheckPermissions(creds, fs.PermMask{Read: true}) {
+ // The calling process does not have read permission on the message
+ // queue, and does not have the CAP_IPC_OWNER capability in the user
+ // namespace that governs its IPC namespace.
+ return nil, linuxerr.EACCES
+ }
+
+ // Queue was removed while the process was waiting.
+ if q.dead {
+ return nil, linuxerr.EIDRM
+ }
+
+ if q.messages.Empty() {
+ return nil, linuxerr.EWOULDBLOCK
+ }
+
+ // Get a message from the queue.
+ switch {
+ case mType == 0:
+ msg = q.messages.Front()
+ case mType > 0:
+ msg = q.msgOfType(mType, except)
+ case mType < 0:
+ msg = q.msgOfTypeLessThan(-1 * mType)
+ }
+
+ // If no message exists, return a blocking singal.
+ if msg == nil {
+ return nil, linuxerr.EWOULDBLOCK
+ }
+
+ // Check message's size is acceptable.
+ if maxSize < msg.Size {
+ if !truncate {
+ return nil, linuxerr.E2BIG
+ }
+ msg.Size = maxSize
+ msg.Text = msg.Text[:maxSize+1]
+ }
+
+ q.messages.Remove(msg)
+
+ q.byteCount -= msg.Size
+ q.messageCount--
+ q.receivePID = pid
+ q.receiveTime = ktime.NowFromContext(ctx)
+
+ // Notify senders about available space.
+ q.senders.Notify(waiter.EventOut)
+
+ return msg, nil
+}
+
+// Copy copies a message from the queue without deleting it. If no message
+// exists, an error is returned. See msgrcv(MSG_COPY).
+func (q *Queue) Copy(mType int64) (*Message, error) {
+ q.mu.Lock()
+ defer q.mu.Unlock()
+
+ if mType < 0 || q.messages.Empty() {
+ return nil, linuxerr.ENOMSG
+ }
+
+ msg := q.msgAtIndex(mType)
+ if msg == nil {
+ return nil, linuxerr.ENOMSG
+ }
+ return msg, nil
+}
+
+// msgOfType returns the first message with the specified type, nil if no
+// message is found. If except is true, the first message of a type not equal
+// to mType will be returned.
+//
+// Precondition: caller must hold q.mu.
+func (q *Queue) msgOfType(mType int64, except bool) *Message {
+ if except {
+ for msg := q.messages.Front(); msg != nil; msg = msg.Next() {
+ if msg.Type != mType {
+ return msg
+ }
+ }
+ return nil
+ }
+
+ for msg := q.messages.Front(); msg != nil; msg = msg.Next() {
+ if msg.Type == mType {
+ return msg
+ }
+ }
+ return nil
+}
+
+// msgOfTypeLessThan return the the first message with the lowest type less
+// than or equal to mType, nil if no such message exists.
+//
+// Precondition: caller must hold q.mu.
+func (q *Queue) msgOfTypeLessThan(mType int64) (m *Message) {
+ min := mType
+ for msg := q.messages.Front(); msg != nil; msg = msg.Next() {
+ if msg.Type <= mType && msg.Type < min {
+ m = msg
+ min = msg.Type
+ }
+ }
+ return m
+}
+
+// msgAtIndex returns a pointer to a message at given index, nil if non exits.
+//
+// Precondition: caller must hold q.mu.
+func (q *Queue) msgAtIndex(mType int64) *Message {
+ msg := q.messages.Front()
+ for ; mType != 0 && msg != nil; mType-- {
+ msg = msg.Next()
+ }
+ return msg
+}
+
// Lock implements ipc.Mechanism.Lock.
func (q *Queue) Lock() {
q.mu.Lock()
diff --git a/pkg/sentry/kernel/msgqueue/msgqueue_state_autogen.go b/pkg/sentry/kernel/msgqueue/msgqueue_state_autogen.go
index 3dfcd09cb..373e01cff 100644
--- a/pkg/sentry/kernel/msgqueue/msgqueue_state_autogen.go
+++ b/pkg/sentry/kernel/msgqueue/msgqueue_state_autogen.go
@@ -158,9 +158,9 @@ func (m *Message) StateTypeName() string {
func (m *Message) StateFields() []string {
return []string{
"msgEntry",
- "mType",
- "mText",
- "mSize",
+ "Type",
+ "Text",
+ "Size",
}
}
@@ -170,9 +170,9 @@ func (m *Message) beforeSave() {}
func (m *Message) StateSave(stateSinkObject state.Sink) {
m.beforeSave()
stateSinkObject.Save(0, &m.msgEntry)
- stateSinkObject.Save(1, &m.mType)
- stateSinkObject.Save(2, &m.mText)
- stateSinkObject.Save(3, &m.mSize)
+ stateSinkObject.Save(1, &m.Type)
+ stateSinkObject.Save(2, &m.Text)
+ stateSinkObject.Save(3, &m.Size)
}
func (m *Message) afterLoad() {}
@@ -180,9 +180,9 @@ func (m *Message) afterLoad() {}
// +checklocksignore
func (m *Message) StateLoad(stateSourceObject state.Source) {
stateSourceObject.Load(0, &m.msgEntry)
- stateSourceObject.Load(1, &m.mType)
- stateSourceObject.Load(2, &m.mText)
- stateSourceObject.Load(3, &m.mSize)
+ stateSourceObject.Load(1, &m.Type)
+ stateSourceObject.Load(2, &m.Text)
+ stateSourceObject.Load(3, &m.Size)
}
func init() {
diff --git a/pkg/sentry/syscalls/linux/linux64.go b/pkg/sentry/syscalls/linux/linux64.go
index 6f44d767b..1ead3c7e8 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.Supported("msgrcv", Msgrcv),
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.Supported("msgrcv", Msgrcv),
+ 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..5259ade90 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 +43,89 @@ 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 {
+ if wait || except {
+ return nil, linuxerr.EINVAL
+ }
+ return queue.Copy(mType)
+ }
+ 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())
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-30 13:20:23 +0000