1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * File: datagram.c
4 *
5 * Datagram (ISI) Phonet sockets
6 *
7 * Copyright (C) 2008 Nokia Corporation.
8 *
9 * Authors: Sakari Ailus <sakari.ailus@nokia.com>
10 * Rémi Denis-Courmont
11 */
12
13 #include <linux/kernel.h>
14 #include <linux/slab.h>
15 #include <linux/socket.h>
16 #include <asm/ioctls.h>
17 #include <net/sock.h>
18
19 #include <linux/phonet.h>
20 #include <linux/export.h>
21 #include <net/phonet/phonet.h>
22
23 static int pn_backlog_rcv(struct sock *sk, struct sk_buff *skb);
24
25 /* associated socket ceases to exist */
pn_sock_close(struct sock * sk,long timeout)26 static void pn_sock_close(struct sock *sk, long timeout)
27 {
28 sk_common_release(sk);
29 }
30
pn_ioctl(struct sock * sk,int cmd,unsigned long arg)31 static int pn_ioctl(struct sock *sk, int cmd, unsigned long arg)
32 {
33 struct sk_buff *skb;
34 int answ;
35
36 switch (cmd) {
37 case SIOCINQ:
38 lock_sock(sk);
39 skb = skb_peek(&sk->sk_receive_queue);
40 answ = skb ? skb->len : 0;
41 release_sock(sk);
42 return put_user(answ, (int __user *)arg);
43
44 case SIOCPNADDRESOURCE:
45 case SIOCPNDELRESOURCE: {
46 u32 res;
47 if (get_user(res, (u32 __user *)arg))
48 return -EFAULT;
49 if (res >= 256)
50 return -EINVAL;
51 if (cmd == SIOCPNADDRESOURCE)
52 return pn_sock_bind_res(sk, res);
53 else
54 return pn_sock_unbind_res(sk, res);
55 }
56 }
57
58 return -ENOIOCTLCMD;
59 }
60
61 /* Destroy socket. All references are gone. */
pn_destruct(struct sock * sk)62 static void pn_destruct(struct sock *sk)
63 {
64 skb_queue_purge(&sk->sk_receive_queue);
65 }
66
pn_init(struct sock * sk)67 static int pn_init(struct sock *sk)
68 {
69 sk->sk_destruct = pn_destruct;
70 return 0;
71 }
72
pn_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)73 static int pn_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
74 {
75 DECLARE_SOCKADDR(struct sockaddr_pn *, target, msg->msg_name);
76 struct sk_buff *skb;
77 int err;
78
79 if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
80 MSG_CMSG_COMPAT))
81 return -EOPNOTSUPP;
82
83 if (target == NULL)
84 return -EDESTADDRREQ;
85
86 if (msg->msg_namelen < sizeof(struct sockaddr_pn))
87 return -EINVAL;
88
89 if (target->spn_family != AF_PHONET)
90 return -EAFNOSUPPORT;
91
92 skb = sock_alloc_send_skb(sk, MAX_PHONET_HEADER + len,
93 msg->msg_flags & MSG_DONTWAIT, &err);
94 if (skb == NULL)
95 return err;
96 skb_reserve(skb, MAX_PHONET_HEADER);
97
98 err = memcpy_from_msg((void *)skb_put(skb, len), msg, len);
99 if (err < 0) {
100 kfree_skb(skb);
101 return err;
102 }
103
104 /*
105 * Fill in the Phonet header and
106 * finally pass the packet forwards.
107 */
108 err = pn_skb_send(sk, skb, target);
109
110 /* If ok, return len. */
111 return (err >= 0) ? len : err;
112 }
113
pn_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int flags,int * addr_len)114 static int pn_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
115 int flags, int *addr_len)
116 {
117 struct sk_buff *skb = NULL;
118 struct sockaddr_pn sa;
119 int rval = -EOPNOTSUPP;
120 int copylen;
121
122 if (flags & ~(MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_NOSIGNAL|
123 MSG_CMSG_COMPAT))
124 goto out_nofree;
125
126 skb = skb_recv_datagram(sk, flags, &rval);
127 if (skb == NULL)
128 goto out_nofree;
129
130 pn_skb_get_src_sockaddr(skb, &sa);
131
132 copylen = skb->len;
133 if (len < copylen) {
134 msg->msg_flags |= MSG_TRUNC;
135 copylen = len;
136 }
137
138 rval = skb_copy_datagram_msg(skb, 0, msg, copylen);
139 if (rval) {
140 rval = -EFAULT;
141 goto out;
142 }
143
144 rval = (flags & MSG_TRUNC) ? skb->len : copylen;
145
146 if (msg->msg_name != NULL) {
147 __sockaddr_check_size(sizeof(sa));
148 memcpy(msg->msg_name, &sa, sizeof(sa));
149 *addr_len = sizeof(sa);
150 }
151
152 out:
153 skb_free_datagram(sk, skb);
154
155 out_nofree:
156 return rval;
157 }
158
159 /* Queue an skb for a sock. */
pn_backlog_rcv(struct sock * sk,struct sk_buff * skb)160 static int pn_backlog_rcv(struct sock *sk, struct sk_buff *skb)
161 {
162 int err = sock_queue_rcv_skb(sk, skb);
163
164 if (err < 0)
165 kfree_skb(skb);
166 return err ? NET_RX_DROP : NET_RX_SUCCESS;
167 }
168
169 /* Module registration */
170 static struct proto pn_proto = {
171 .close = pn_sock_close,
172 .ioctl = pn_ioctl,
173 .init = pn_init,
174 .sendmsg = pn_sendmsg,
175 .recvmsg = pn_recvmsg,
176 .backlog_rcv = pn_backlog_rcv,
177 .hash = pn_sock_hash,
178 .unhash = pn_sock_unhash,
179 .get_port = pn_sock_get_port,
180 .obj_size = sizeof(struct pn_sock),
181 .owner = THIS_MODULE,
182 .name = "PHONET",
183 };
184
185 static const struct phonet_protocol pn_dgram_proto = {
186 .ops = &phonet_dgram_ops,
187 .prot = &pn_proto,
188 .sock_type = SOCK_DGRAM,
189 };
190
isi_register(void)191 int __init isi_register(void)
192 {
193 return phonet_proto_register(PN_PROTO_PHONET, &pn_dgram_proto);
194 }
195
isi_unregister(void)196 void __exit isi_unregister(void)
197 {
198 phonet_proto_unregister(PN_PROTO_PHONET, &pn_dgram_proto);
199 }
200