summaryrefslogtreecommitdiffstats
path: root/net/phonet/datagram.c
blob: 393e6aa7a5927d4b8ef61a35d99d41c4cad8c815 (plain)
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
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
// SPDX-License-Identifier: GPL-2.0-only
/*
 * File: datagram.c
 *
 * Datagram (ISI) Phonet sockets
 *
 * Copyright (C) 2008 Nokia Corporation.
 *
 * Authors: Sakari Ailus <sakari.ailus@nokia.com>
 *          Rémi Denis-Courmont
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/socket.h>
#include <asm/ioctls.h>
#include <net/sock.h>

#include <linux/phonet.h>
#include <linux/export.h>
#include <net/phonet/phonet.h>

static int pn_backlog_rcv(struct sock *sk, struct sk_buff *skb);

/* associated socket ceases to exist */
static void pn_sock_close(struct sock *sk, long timeout)
{
	sk_common_release(sk);
}

static int pn_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
	struct sk_buff *skb;
	int answ;

	switch (cmd) {
	case SIOCINQ:
		lock_sock(sk);
		skb = skb_peek(&sk->sk_receive_queue);
		answ = skb ? skb->len : 0;
		release_sock(sk);
		return put_user(answ, (int __user *)arg);

	case SIOCPNADDRESOURCE:
	case SIOCPNDELRESOURCE: {
			u32 res;
			if (get_user(res, (u32 __user *)arg))
				return -EFAULT;
			if (res >= 256)
				return -EINVAL;
			if (cmd == SIOCPNADDRESOURCE)
				return pn_sock_bind_res(sk, res);
			else
				return pn_sock_unbind_res(sk, res);
		}
	}

	return -ENOIOCTLCMD;
}

/* Destroy socket. All references are gone. */
static void pn_destruct(struct sock *sk)
{
	skb_queue_purge(&sk->sk_receive_queue);
}

static int pn_init(struct sock *sk)
{
	sk->sk_destruct = pn_destruct;
	return 0;
}

static int pn_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
{
	DECLARE_SOCKADDR(struct sockaddr_pn *, target, msg->msg_name);
	struct sk_buff *skb;
	int err;

	if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
				MSG_CMSG_COMPAT))
		return -EOPNOTSUPP;

	if (target == NULL)
		return -EDESTADDRREQ;

	if (msg->msg_namelen < sizeof(struct sockaddr_pn))
		return -EINVAL;

	if (target->spn_family != AF_PHONET)
		return -EAFNOSUPPORT;

	skb = sock_alloc_send_skb(sk, MAX_PHONET_HEADER + len,
					msg->msg_flags & MSG_DONTWAIT, &err);
	if (skb == NULL)
		return err;
	skb_reserve(skb, MAX_PHONET_HEADER);

	err = memcpy_from_msg((void *)skb_put(skb, len), msg, len);
	if (err < 0) {
		kfree_skb(skb);
		return err;
	}

	/*
	 * Fill in the Phonet header and
	 * finally pass the packet forwards.
	 */
	err = pn_skb_send(sk, skb, target);

	/* If ok, return len. */
	return (err >= 0) ? len : err;
}

static int pn_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
		      int noblock, int flags, int *addr_len)
{
	struct sk_buff *skb = NULL;
	struct sockaddr_pn sa;
	int rval = -EOPNOTSUPP;
	int copylen;

	if (flags & ~(MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_NOSIGNAL|
			MSG_CMSG_COMPAT))
		goto out_nofree;

	skb = skb_recv_datagram(sk, flags, noblock, &rval);
	if (skb == NULL)
		goto out_nofree;

	pn_skb_get_src_sockaddr(skb, &sa);

	copylen = skb->len;
	if (len < copylen) {
		msg->msg_flags |= MSG_TRUNC;
		copylen = len;
	}

	rval = skb_copy_datagram_msg(skb, 0, msg, copylen);
	if (rval) {
		rval = -EFAULT;
		goto out;
	}

	rval = (flags & MSG_TRUNC) ? skb->len : copylen;

	if (msg->msg_name != NULL) {
		__sockaddr_check_size(sizeof(sa));
		memcpy(msg->msg_name, &sa, sizeof(sa));
		*addr_len = sizeof(sa);
	}

out:
	skb_free_datagram(sk, skb);

out_nofree:
	return rval;
}

/* Queue an skb for a sock. */
static int pn_backlog_rcv(struct sock *sk, struct sk_buff *skb)
{
	int err = sock_queue_rcv_skb(sk, skb);

	if (err < 0)
		kfree_skb(skb);
	return err ? NET_RX_DROP : NET_RX_SUCCESS;
}

/* Module registration */
static struct proto pn_proto = {
	.close		= pn_sock_close,
	.ioctl		= pn_ioctl,
	.init		= pn_init,
	.sendmsg	= pn_sendmsg,
	.recvmsg	= pn_recvmsg,
	.backlog_rcv	= pn_backlog_rcv,
	.hash		= pn_sock_hash,
	.unhash		= pn_sock_unhash,
	.get_port	= pn_sock_get_port,
	.obj_size	= sizeof(struct pn_sock),
	.owner		= THIS_MODULE,
	.name		= "PHONET",
};

static const struct phonet_protocol pn_dgram_proto = {
	.ops		= &phonet_dgram_ops,
	.prot		= &pn_proto,
	.sock_type	= SOCK_DGRAM,
};

int __init isi_register(void)
{
	return phonet_proto_register(PN_PROTO_PHONET, &pn_dgram_proto);
}

void __exit isi_unregister(void)
{
	phonet_proto_unregister(PN_PROTO_PHONET, &pn_dgram_proto);
}
OpenPOWER on IntegriCloud