1// socket_linux.go -- Socket handling specific to GNU/Linux.
2
3// Copyright 2010 The Go Authors. All rights reserved.
4// Use of this source code is governed by a BSD-style
5// license that can be found in the LICENSE file.
6
7package syscall
8
9import "unsafe"
10
11const SizeofSockaddrInet4 = 16
12const SizeofSockaddrInet6 = 28
13const SizeofSockaddrUnix = 110
14const SizeofSockaddrLinklayer = 20
15const SizeofSockaddrNetlink = 12
16
17type SockaddrLinklayer struct {
18	Protocol uint16
19	Ifindex  int
20	Hatype   uint16
21	Pkttype  uint8
22	Halen    uint8
23	Addr     [8]byte
24	raw      RawSockaddrLinklayer
25}
26
27func (sa *SockaddrLinklayer) sockaddr() (*RawSockaddrAny, Socklen_t, error) {
28	if sa.Ifindex < 0 || sa.Ifindex > 0x7fffffff {
29		return nil, 0, EINVAL
30	}
31	sa.raw.Family = AF_PACKET
32	sa.raw.Protocol = sa.Protocol
33	sa.raw.Ifindex = int32(sa.Ifindex)
34	sa.raw.Hatype = sa.Hatype
35	sa.raw.Pkttype = sa.Pkttype
36	sa.raw.Halen = sa.Halen
37	for i := 0; i < len(sa.Addr); i++ {
38		sa.raw.Addr[i] = sa.Addr[i]
39	}
40	return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), SizeofSockaddrLinklayer, nil
41}
42
43type SockaddrNetlink struct {
44	Family uint16
45	Pad    uint16
46	Pid    uint32
47	Groups uint32
48	raw    RawSockaddrNetlink
49}
50
51func (sa *SockaddrNetlink) sockaddr() (*RawSockaddrAny, Socklen_t, error) {
52	sa.raw.Family = AF_NETLINK
53	sa.raw.Pad = sa.Pad
54	sa.raw.Pid = sa.Pid
55	sa.raw.Groups = sa.Groups
56	return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), SizeofSockaddrNetlink, nil
57}
58
59type RawSockaddrInet4 struct {
60	Family uint16
61	Port   uint16
62	Addr   [4]byte /* in_addr */
63	Zero   [8]uint8
64}
65
66func (sa *RawSockaddrInet4) setLen() Socklen_t {
67	return SizeofSockaddrInet4
68}
69
70type RawSockaddrInet6 struct {
71	Family   uint16
72	Port     uint16
73	Flowinfo uint32
74	Addr     [16]byte /* in6_addr */
75	Scope_id uint32
76}
77
78func (sa *RawSockaddrInet6) setLen() Socklen_t {
79	return SizeofSockaddrInet6
80}
81
82type RawSockaddrUnix struct {
83	Family uint16
84	Path   [108]int8
85}
86
87func (sa *RawSockaddrUnix) setLen(int) {
88}
89
90func (sa *RawSockaddrUnix) getLen() (int, error) {
91	if sa.Path[0] == 0 {
92		// "Abstract" Unix domain socket.
93		// Rewrite leading NUL as @ for textual display.
94		// (This is the standard convention.)
95		// Not friendly to overwrite in place,
96		// but the callers below don't care.
97		sa.Path[0] = '@'
98	}
99
100	// Assume path ends at NUL.
101	// This is not technically the GNU/Linux semantics for
102	// abstract Unix domain sockets--they are supposed
103	// to be uninterpreted fixed-size binary blobs--but
104	// everyone uses this convention.
105	n := 0
106	for n < len(sa.Path) && sa.Path[n] != 0 {
107		n++
108	}
109
110	return n, nil
111}
112
113func (sa *RawSockaddrUnix) adjustAbstract(sl Socklen_t) Socklen_t {
114	if sa.Path[0] == '@' {
115		sa.Path[0] = 0
116		// Don't count trailing NUL for abstract address.
117		sl--
118	}
119	return sl
120}
121
122type RawSockaddrLinklayer struct {
123	Family   uint16
124	Protocol uint16
125	Ifindex  int32
126	Hatype   uint16
127	Pkttype  uint8
128	Halen    uint8
129	Addr     [8]uint8
130}
131
132type RawSockaddrNetlink struct {
133	Family uint16
134	Pad    uint16
135	Pid    uint32
136	Groups uint32
137}
138
139// BindToDevice binds the socket associated with fd to device.
140func BindToDevice(fd int, device string) (err error) {
141	return SetsockoptString(fd, SOL_SOCKET, SO_BINDTODEVICE, device)
142}
143
144func anyToSockaddrOS(rsa *RawSockaddrAny) (Sockaddr, error) {
145	switch rsa.Addr.Family {
146	case AF_NETLINK:
147		pp := (*RawSockaddrNetlink)(unsafe.Pointer(rsa))
148		sa := new(SockaddrNetlink)
149		sa.Family = pp.Family
150		sa.Pad = pp.Pad
151		sa.Pid = pp.Pid
152		sa.Groups = pp.Groups
153		return sa, nil
154
155	case AF_PACKET:
156		pp := (*RawSockaddrLinklayer)(unsafe.Pointer(rsa))
157		sa := new(SockaddrLinklayer)
158		sa.Protocol = pp.Protocol
159		sa.Ifindex = int(pp.Ifindex)
160		sa.Hatype = pp.Hatype
161		sa.Pkttype = pp.Pkttype
162		sa.Halen = pp.Halen
163		for i := 0; i < len(sa.Addr); i++ {
164			sa.Addr[i] = pp.Addr[i]
165		}
166		return sa, nil
167	}
168	return nil, EAFNOSUPPORT
169}
170
171func GetsockoptIPv6MTUInfo(fd, level, opt int) (*IPv6MTUInfo, error) {
172	var value IPv6MTUInfo
173	vallen := Socklen_t(SizeofIPv6MTUInfo)
174	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
175	return &value, err
176}
177
178func GetsockoptUcred(fd, level, opt int) (*Ucred, error) {
179	var value Ucred
180	vallen := Socklen_t(SizeofUcred)
181	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
182	return &value, err
183}
184
185//sysnb	EpollCreate(size int) (fd int, err error)
186//epoll_create(size _C_int) _C_int
187
188//sysnb EpollCreate1(flags int) (fd int, err error)
189//epoll_create1(flags _C_int) _C_int
190
191//sysnb	EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error)
192//epoll_ctl(epfd _C_int, op _C_int, fd _C_int, event *EpollEvent) _C_int
193
194//sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
195//epoll_wait(epfd _C_int, events *EpollEvent, maxevents _C_int, timeout _C_int) _C_int
196