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,int * karg)31 static int pn_ioctl(struct sock *sk, int cmd, int *karg)
32 {
33 struct sk_buff *skb;
34
35 switch (cmd) {
36 case SIOCINQ:
37 spin_lock_bh(&sk->sk_receive_queue.lock);
38 skb = skb_peek(&sk->sk_receive_queue);
39 *karg = skb ? skb->len : 0;
40 spin_unlock_bh(&sk->sk_receive_queue.lock);
41 return 0;
42
43 case SIOCPNADDRESOURCE:
44 case SIOCPNDELRESOURCE: {
45 u32 res = *karg;
46 if (res >= 256)
47 return -EINVAL;
48 if (cmd == SIOCPNADDRESOURCE)
49 return pn_sock_bind_res(sk, res);
50 else
51 return pn_sock_unbind_res(sk, res);
52 }
53 }
54
55 return -ENOIOCTLCMD;
56 }
57
58 /* Destroy socket. All references are gone. */
pn_destruct(struct sock * sk)59 static void pn_destruct(struct sock *sk)
60 {
61 skb_queue_purge(&sk->sk_receive_queue);
62 }
63
pn_init(struct sock * sk)64 static int pn_init(struct sock *sk)
65 {
66 sk->sk_destruct = pn_destruct;
67 return 0;
68 }
69
pn_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)70 static int pn_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
71 {
72 DECLARE_SOCKADDR(struct sockaddr_pn *, target, msg->msg_name);
73 struct sk_buff *skb;
74 int err;
75
76 if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
77 MSG_CMSG_COMPAT))
78 return -EOPNOTSUPP;
79
80 if (target == NULL)
81 return -EDESTADDRREQ;
82
83 if (msg->msg_namelen < sizeof(struct sockaddr_pn))
84 return -EINVAL;
85
86 if (target->spn_family != AF_PHONET)
87 return -EAFNOSUPPORT;
88
89 skb = sock_alloc_send_skb(sk, MAX_PHONET_HEADER + len,
90 msg->msg_flags & MSG_DONTWAIT, &err);
91 if (skb == NULL)
92 return err;
93 skb_reserve(skb, MAX_PHONET_HEADER);
94
95 err = memcpy_from_msg((void *)skb_put(skb, len), msg, len);
96 if (err < 0) {
97 kfree_skb(skb);
98 return err;
99 }
100
101 /*
102 * Fill in the Phonet header and
103 * finally pass the packet forwards.
104 */
105 err = pn_skb_send(sk, skb, target);
106
107 /* If ok, return len. */
108 return (err >= 0) ? len : err;
109 }
110
pn_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int flags,int * addr_len)111 static int pn_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
112 int flags, int *addr_len)
113 {
114 struct sk_buff *skb = NULL;
115 struct sockaddr_pn sa;
116 int rval = -EOPNOTSUPP;
117 int copylen;
118
119 if (flags & ~(MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_NOSIGNAL|
120 MSG_CMSG_COMPAT))
121 goto out_nofree;
122
123 skb = skb_recv_datagram(sk, flags, &rval);
124 if (skb == NULL)
125 goto out_nofree;
126
127 pn_skb_get_src_sockaddr(skb, &sa);
128
129 copylen = skb->len;
130 if (len < copylen) {
131 msg->msg_flags |= MSG_TRUNC;
132 copylen = len;
133 }
134
135 rval = skb_copy_datagram_msg(skb, 0, msg, copylen);
136 if (rval) {
137 rval = -EFAULT;
138 goto out;
139 }
140
141 rval = (flags & MSG_TRUNC) ? skb->len : copylen;
142
143 if (msg->msg_name != NULL) {
144 __sockaddr_check_size(sizeof(sa));
145 memcpy(msg->msg_name, &sa, sizeof(sa));
146 *addr_len = sizeof(sa);
147 }
148
149 out:
150 skb_free_datagram(sk, skb);
151
152 out_nofree:
153 return rval;
154 }
155
156 /* Queue an skb for a sock. */
pn_backlog_rcv(struct sock * sk,struct sk_buff * skb)157 static int pn_backlog_rcv(struct sock *sk, struct sk_buff *skb)
158 {
159 int err = sock_queue_rcv_skb(sk, skb);
160
161 if (err < 0)
162 kfree_skb(skb);
163 return err ? NET_RX_DROP : NET_RX_SUCCESS;
164 }
165
166 /* Module registration */
167 static struct proto pn_proto = {
168 .close = pn_sock_close,
169 .ioctl = pn_ioctl,
170 .init = pn_init,
171 .sendmsg = pn_sendmsg,
172 .recvmsg = pn_recvmsg,
173 .backlog_rcv = pn_backlog_rcv,
174 .hash = pn_sock_hash,
175 .unhash = pn_sock_unhash,
176 .get_port = pn_sock_get_port,
177 .obj_size = sizeof(struct pn_sock),
178 .owner = THIS_MODULE,
179 .name = "PHONET",
180 };
181
182 static const struct phonet_protocol pn_dgram_proto = {
183 .ops = &phonet_dgram_ops,
184 .prot = &pn_proto,
185 .sock_type = SOCK_DGRAM,
186 };
187
isi_register(void)188 int __init isi_register(void)
189 {
190 return phonet_proto_register(PN_PROTO_PHONET, &pn_dgram_proto);
191 }
192
isi_unregister(void)193 void __exit isi_unregister(void)
194 {
195 phonet_proto_unregister(PN_PROTO_PHONET, &pn_dgram_proto);
196 }
197