1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
|
// Copyright 2018 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package netlink
import (
"fmt"
"gvisor.googlesource.com/gvisor/pkg/abi/linux"
"gvisor.googlesource.com/gvisor/pkg/sentry/context"
"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
"gvisor.googlesource.com/gvisor/pkg/sentry/kernel"
"gvisor.googlesource.com/gvisor/pkg/sentry/socket"
"gvisor.googlesource.com/gvisor/pkg/syserr"
"gvisor.googlesource.com/gvisor/pkg/tcpip/transport/unix"
)
// Protocol is the implementation of a netlink socket protocol.
type Protocol interface {
// Protocol returns the Linux netlink protocol value.
Protocol() int
// ProcessMessage processes a single message from userspace.
//
// If err == nil, any messages added to ms will be sent back to the
// other end of the socket. Setting ms.Multi will cause an NLMSG_DONE
// message to be sent even if ms contains no messages.
ProcessMessage(ctx context.Context, hdr linux.NetlinkMessageHeader, data []byte, ms *MessageSet) *syserr.Error
}
// Provider is a function that creates a new Protocol for a specific netlink
// protocol.
//
// Note that this is distinct from socket.Provider, which is used for all
// socket families.
type Provider func(t *kernel.Task) (Protocol, *syserr.Error)
// protocols holds a map of all known address protocols and their provider.
var protocols = make(map[int]Provider)
// RegisterProvider registers the provider of a given address protocol so that
// netlink sockets of that type can be created via socket(2).
//
// Preconditions: May only be called before any netlink sockets are created.
func RegisterProvider(protocol int, provider Provider) {
if p, ok := protocols[protocol]; ok {
panic(fmt.Sprintf("Netlink protocol %d already provided by %+v", protocol, p))
}
protocols[protocol] = provider
}
// socketProvider implements socket.Provider.
type socketProvider struct {
}
// Socket implements socket.Provider.Socket.
func (*socketProvider) Socket(t *kernel.Task, stype unix.SockType, protocol int) (*fs.File, *syserr.Error) {
// Netlink sockets must be specified as datagram or raw, but they
// behave the same regardless of type.
if stype != unix.SockDgram && stype != unix.SockRaw {
return nil, syserr.ErrSocketNotSupported
}
provider, ok := protocols[protocol]
if !ok {
return nil, syserr.ErrProtocolNotSupported
}
p, err := provider(t)
if err != nil {
return nil, err
}
s, err := NewSocket(t, p)
if err != nil {
return nil, err
}
d := socket.NewDirent(t, netlinkSocketDevice)
return fs.NewFile(t, d, fs.FileFlags{Read: true, Write: true}, s), nil
}
// Pair implements socket.Provider.Pair by returning an error.
func (*socketProvider) Pair(*kernel.Task, unix.SockType, int) (*fs.File, *fs.File, *syserr.Error) {
// Netlink sockets never supports creating socket pairs.
return nil, nil, syserr.ErrNotSupported
}
// init registers the socket provider.
func init() {
socket.RegisterProvider(linux.AF_NETLINK, &socketProvider{})
}
|
