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 | * RĂ©mi 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 */ |
26 | static void pn_sock_close(struct sock *sk, long timeout) |
27 | { |
28 | sk_common_release(sk); |
29 | } |
30 | |
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(lock: &sk->sk_receive_queue.lock); |
38 | skb = skb_peek(list_: &sk->sk_receive_queue); |
39 | *karg = skb ? skb->len : 0; |
40 | spin_unlock_bh(lock: &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(sock: 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. */ |
59 | static void pn_destruct(struct sock *sk) |
60 | { |
61 | skb_queue_purge(list: &sk->sk_receive_queue); |
62 | } |
63 | |
64 | static int pn_init(struct sock *sk) |
65 | { |
66 | sk->sk_destruct = pn_destruct; |
67 | return 0; |
68 | } |
69 | |
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 | noblock: msg->msg_flags & MSG_DONTWAIT, errcode: &err); |
91 | if (skb == NULL) |
92 | return err; |
93 | skb_reserve(skb, MAX_PHONET_HEADER); |
94 | |
95 | err = memcpy_from_msg(data: (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 | |
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, err: &rval); |
124 | if (skb == NULL) |
125 | goto out_nofree; |
126 | |
127 | pn_skb_get_src_sockaddr(skb, sa: &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(from: skb, offset: 0, msg, size: 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. */ |
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 | |
188 | int __init isi_register(void) |
189 | { |
190 | return phonet_proto_register(PN_PROTO_PHONET, pp: &pn_dgram_proto); |
191 | } |
192 | |
193 | void __exit isi_unregister(void) |
194 | { |
195 | phonet_proto_unregister(PN_PROTO_PHONET, pp: &pn_dgram_proto); |
196 | } |
197 | |