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path: root/pkg/sentry/socket/control/control.go
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Diffstat (limited to 'pkg/sentry/socket/control/control.go')
-rw-r--r--pkg/sentry/socket/control/control.go215
1 files changed, 158 insertions, 57 deletions
diff --git a/pkg/sentry/socket/control/control.go b/pkg/sentry/socket/control/control.go
index 4e95101b7..1684dfc24 100644
--- a/pkg/sentry/socket/control/control.go
+++ b/pkg/sentry/socket/control/control.go
@@ -23,6 +23,7 @@ import (
"gvisor.dev/gvisor/pkg/sentry/fs"
"gvisor.dev/gvisor/pkg/sentry/kernel"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/pkg/sentry/socket"
"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
"gvisor.dev/gvisor/pkg/sentry/usermem"
"gvisor.dev/gvisor/pkg/syserror"
@@ -194,15 +195,15 @@ func putCmsg(buf []byte, flags int, msgType uint32, align uint, data []int32) ([
// the available space, we must align down.
//
// align must be >= 4 and each data int32 is 4 bytes. The length of the
- // header is already aligned, so if we align to the with of the data there
+ // header is already aligned, so if we align to the width of the data there
// are two cases:
// 1. The aligned length is less than the length of the header. The
// unaligned length was also less than the length of the header, so we
// can't write anything.
// 2. The aligned length is greater than or equal to the length of the
- // header. We can write the header plus zero or more datas. We can't write
- // a partial int32, so the length of the message will be
- // min(aligned length, header + datas).
+ // header. We can write the header plus zero or more bytes of data. We can't
+ // write a partial int32, so the length of the message will be
+ // min(aligned length, header + data).
if space < linux.SizeOfControlMessageHeader {
flags |= linux.MSG_CTRUNC
return buf, flags
@@ -239,12 +240,12 @@ func putCmsgStruct(buf []byte, msgLevel, msgType uint32, align uint, data interf
buf = binary.Marshal(buf, usermem.ByteOrder, data)
- // Check if we went over.
+ // If the control message data brought us over capacity, omit it.
if cap(buf) != cap(ob) {
return hdrBuf
}
- // Fix up length.
+ // Update control message length to include data.
putUint64(ob, uint64(len(buf)-len(ob)))
return alignSlice(buf, align)
@@ -320,35 +321,109 @@ func PackInq(t *kernel.Task, inq int32, buf []byte) []byte {
buf,
linux.SOL_TCP,
linux.TCP_INQ,
- 4,
+ t.Arch().Width(),
inq,
)
}
+// PackTOS packs an IP_TOS socket control message.
+func PackTOS(t *kernel.Task, tos uint8, buf []byte) []byte {
+ return putCmsgStruct(
+ buf,
+ linux.SOL_IP,
+ linux.IP_TOS,
+ t.Arch().Width(),
+ tos,
+ )
+}
+
+// PackTClass packs an IPV6_TCLASS socket control message.
+func PackTClass(t *kernel.Task, tClass int32, buf []byte) []byte {
+ return putCmsgStruct(
+ buf,
+ linux.SOL_IPV6,
+ linux.IPV6_TCLASS,
+ t.Arch().Width(),
+ tClass,
+ )
+}
+
+// PackControlMessages packs control messages into the given buffer.
+//
+// We skip control messages specific to Unix domain sockets.
+//
+// Note that some control messages may be truncated if they do not fit under
+// the capacity of buf.
+func PackControlMessages(t *kernel.Task, cmsgs socket.ControlMessages, buf []byte) []byte {
+ if cmsgs.IP.HasTimestamp {
+ buf = PackTimestamp(t, cmsgs.IP.Timestamp, buf)
+ }
+
+ if cmsgs.IP.HasInq {
+ // In Linux, TCP_CM_INQ is added after SO_TIMESTAMP.
+ buf = PackInq(t, cmsgs.IP.Inq, buf)
+ }
+
+ if cmsgs.IP.HasTOS {
+ buf = PackTOS(t, cmsgs.IP.TOS, buf)
+ }
+
+ if cmsgs.IP.HasTClass {
+ buf = PackTClass(t, cmsgs.IP.TClass, buf)
+ }
+
+ return buf
+}
+
+// cmsgSpace is equivalent to CMSG_SPACE in Linux.
+func cmsgSpace(t *kernel.Task, dataLen int) int {
+ return linux.SizeOfControlMessageHeader + AlignUp(dataLen, t.Arch().Width())
+}
+
+// CmsgsSpace returns the number of bytes needed to fit the control messages
+// represented in cmsgs.
+func CmsgsSpace(t *kernel.Task, cmsgs socket.ControlMessages) int {
+ space := 0
+
+ if cmsgs.IP.HasTimestamp {
+ space += cmsgSpace(t, linux.SizeOfTimeval)
+ }
+
+ if cmsgs.IP.HasInq {
+ space += cmsgSpace(t, linux.SizeOfControlMessageInq)
+ }
+
+ if cmsgs.IP.HasTOS {
+ space += cmsgSpace(t, linux.SizeOfControlMessageTOS)
+ }
+
+ if cmsgs.IP.HasTClass {
+ space += cmsgSpace(t, linux.SizeOfControlMessageTClass)
+ }
+
+ return space
+}
+
// Parse parses a raw socket control message into portable objects.
-func Parse(t *kernel.Task, socketOrEndpoint interface{}, buf []byte) (transport.ControlMessages, error) {
+func Parse(t *kernel.Task, socketOrEndpoint interface{}, buf []byte) (socket.ControlMessages, error) {
var (
- fds linux.ControlMessageRights
- haveCreds bool
- creds linux.ControlMessageCredentials
+ cmsgs socket.ControlMessages
+ fds linux.ControlMessageRights
)
for i := 0; i < len(buf); {
if i+linux.SizeOfControlMessageHeader > len(buf) {
- return transport.ControlMessages{}, syserror.EINVAL
+ return cmsgs, syserror.EINVAL
}
var h linux.ControlMessageHeader
binary.Unmarshal(buf[i:i+linux.SizeOfControlMessageHeader], usermem.ByteOrder, &h)
if h.Length < uint64(linux.SizeOfControlMessageHeader) {
- return transport.ControlMessages{}, syserror.EINVAL
+ return socket.ControlMessages{}, syserror.EINVAL
}
if h.Length > uint64(len(buf)-i) {
- return transport.ControlMessages{}, syserror.EINVAL
- }
- if h.Level != linux.SOL_SOCKET {
- return transport.ControlMessages{}, syserror.EINVAL
+ return socket.ControlMessages{}, syserror.EINVAL
}
i += linux.SizeOfControlMessageHeader
@@ -358,59 +433,85 @@ func Parse(t *kernel.Task, socketOrEndpoint interface{}, buf []byte) (transport.
// sizeof(long) in CMSG_ALIGN.
width := t.Arch().Width()
- switch h.Type {
- case linux.SCM_RIGHTS:
- rightsSize := AlignDown(length, linux.SizeOfControlMessageRight)
- numRights := rightsSize / linux.SizeOfControlMessageRight
-
- if len(fds)+numRights > linux.SCM_MAX_FD {
- return transport.ControlMessages{}, syserror.EINVAL
+ switch h.Level {
+ case linux.SOL_SOCKET:
+ switch h.Type {
+ case linux.SCM_RIGHTS:
+ rightsSize := AlignDown(length, linux.SizeOfControlMessageRight)
+ numRights := rightsSize / linux.SizeOfControlMessageRight
+
+ if len(fds)+numRights > linux.SCM_MAX_FD {
+ return socket.ControlMessages{}, syserror.EINVAL
+ }
+
+ for j := i; j < i+rightsSize; j += linux.SizeOfControlMessageRight {
+ fds = append(fds, int32(usermem.ByteOrder.Uint32(buf[j:j+linux.SizeOfControlMessageRight])))
+ }
+
+ i += AlignUp(length, width)
+
+ case linux.SCM_CREDENTIALS:
+ if length < linux.SizeOfControlMessageCredentials {
+ return socket.ControlMessages{}, syserror.EINVAL
+ }
+
+ var creds linux.ControlMessageCredentials
+ binary.Unmarshal(buf[i:i+linux.SizeOfControlMessageCredentials], usermem.ByteOrder, &creds)
+ scmCreds, err := NewSCMCredentials(t, creds)
+ if err != nil {
+ return socket.ControlMessages{}, err
+ }
+ cmsgs.Unix.Credentials = scmCreds
+ i += AlignUp(length, width)
+
+ default:
+ // Unknown message type.
+ return socket.ControlMessages{}, syserror.EINVAL
}
-
- for j := i; j < i+rightsSize; j += linux.SizeOfControlMessageRight {
- fds = append(fds, int32(usermem.ByteOrder.Uint32(buf[j:j+linux.SizeOfControlMessageRight])))
+ case linux.SOL_IP:
+ switch h.Type {
+ case linux.IP_TOS:
+ if length < linux.SizeOfControlMessageTOS {
+ return socket.ControlMessages{}, syserror.EINVAL
+ }
+ cmsgs.IP.HasTOS = true
+ binary.Unmarshal(buf[i:i+linux.SizeOfControlMessageTOS], usermem.ByteOrder, &cmsgs.IP.TOS)
+ i += AlignUp(length, width)
+
+ default:
+ return socket.ControlMessages{}, syserror.EINVAL
}
-
- i += AlignUp(length, width)
-
- case linux.SCM_CREDENTIALS:
- if length < linux.SizeOfControlMessageCredentials {
- return transport.ControlMessages{}, syserror.EINVAL
+ case linux.SOL_IPV6:
+ switch h.Type {
+ case linux.IPV6_TCLASS:
+ if length < linux.SizeOfControlMessageTClass {
+ return socket.ControlMessages{}, syserror.EINVAL
+ }
+ cmsgs.IP.HasTClass = true
+ binary.Unmarshal(buf[i:i+linux.SizeOfControlMessageTClass], usermem.ByteOrder, &cmsgs.IP.TClass)
+ i += AlignUp(length, width)
+
+ default:
+ return socket.ControlMessages{}, syserror.EINVAL
}
-
- binary.Unmarshal(buf[i:i+linux.SizeOfControlMessageCredentials], usermem.ByteOrder, &creds)
- haveCreds = true
- i += AlignUp(length, width)
-
default:
- // Unknown message type.
- return transport.ControlMessages{}, syserror.EINVAL
+ return socket.ControlMessages{}, syserror.EINVAL
}
}
- var credentials SCMCredentials
- if haveCreds {
- var err error
- if credentials, err = NewSCMCredentials(t, creds); err != nil {
- return transport.ControlMessages{}, err
- }
- } else {
- credentials = makeCreds(t, socketOrEndpoint)
+ if cmsgs.Unix.Credentials == nil {
+ cmsgs.Unix.Credentials = makeCreds(t, socketOrEndpoint)
}
- var rights SCMRights
if len(fds) > 0 {
- var err error
- if rights, err = NewSCMRights(t, fds); err != nil {
- return transport.ControlMessages{}, err
+ rights, err := NewSCMRights(t, fds)
+ if err != nil {
+ return socket.ControlMessages{}, err
}
+ cmsgs.Unix.Rights = rights
}
- if credentials == nil && rights == nil {
- return transport.ControlMessages{}, nil
- }
-
- return transport.ControlMessages{Credentials: credentials, Rights: rights}, nil
+ return cmsgs, nil
}
func makeCreds(t *kernel.Task, socketOrEndpoint interface{}) SCMCredentials {
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-03 03:32:10 +0000