1 /* 2 * File: datagram.c 3 * 4 * Datagram (ISI) Phonet sockets 5 * 6 * Copyright (C) 2008 Nokia Corporation. 7 * 8 * Authors: Sakari Ailus <sakari.ailus@nokia.com> 9 * Rémi Denis-Courmont 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License 13 * version 2 as published by the Free Software Foundation. 14 * 15 * This program is distributed in the hope that it will be useful, but 16 * WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 18 * General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, write to the Free Software 22 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 23 * 02110-1301 USA 24 */ 25 26 #include <linux/kernel.h> 27 #include <linux/slab.h> 28 #include <linux/socket.h> 29 #include <asm/ioctls.h> 30 #include <net/sock.h> 31 32 #include <linux/phonet.h> 33 #include <linux/export.h> 34 #include <net/phonet/phonet.h> 35 36 static int pn_backlog_rcv(struct sock *sk, struct sk_buff *skb); 37 38 /* associated socket ceases to exist */ 39 static void pn_sock_close(struct sock *sk, long timeout) 40 { 41 sk_common_release(sk); 42 } 43 44 static int pn_ioctl(struct sock *sk, int cmd, unsigned long arg) 45 { 46 struct sk_buff *skb; 47 int answ; 48 49 switch (cmd) { 50 case SIOCINQ: 51 lock_sock(sk); 52 skb = skb_peek(&sk->sk_receive_queue); 53 answ = skb ? skb->len : 0; 54 release_sock(sk); 55 return put_user(answ, (int __user *)arg); 56 57 case SIOCPNADDRESOURCE: 58 case SIOCPNDELRESOURCE: { 59 u32 res; 60 if (get_user(res, (u32 __user *)arg)) 61 return -EFAULT; 62 if (res >= 256) 63 return -EINVAL; 64 if (cmd == SIOCPNADDRESOURCE) 65 return pn_sock_bind_res(sk, res); 66 else 67 return pn_sock_unbind_res(sk, res); 68 } 69 } 70 71 return -ENOIOCTLCMD; 72 } 73 74 /* Destroy socket. All references are gone. */ 75 static void pn_destruct(struct sock *sk) 76 { 77 skb_queue_purge(&sk->sk_receive_queue); 78 } 79 80 static int pn_init(struct sock *sk) 81 { 82 sk->sk_destruct = pn_destruct; 83 return 0; 84 } 85 86 static int pn_sendmsg(struct kiocb *iocb, struct sock *sk, 87 struct msghdr *msg, size_t len) 88 { 89 DECLARE_SOCKADDR(struct sockaddr_pn *, target, msg->msg_name); 90 struct sk_buff *skb; 91 int err; 92 93 if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL| 94 MSG_CMSG_COMPAT)) 95 return -EOPNOTSUPP; 96 97 if (target == NULL) 98 return -EDESTADDRREQ; 99 100 if (msg->msg_namelen < sizeof(struct sockaddr_pn)) 101 return -EINVAL; 102 103 if (target->spn_family != AF_PHONET) 104 return -EAFNOSUPPORT; 105 106 skb = sock_alloc_send_skb(sk, MAX_PHONET_HEADER + len, 107 msg->msg_flags & MSG_DONTWAIT, &err); 108 if (skb == NULL) 109 return err; 110 skb_reserve(skb, MAX_PHONET_HEADER); 111 112 err = memcpy_from_msg((void *)skb_put(skb, len), msg, len); 113 if (err < 0) { 114 kfree_skb(skb); 115 return err; 116 } 117 118 /* 119 * Fill in the Phonet header and 120 * finally pass the packet forwards. 121 */ 122 err = pn_skb_send(sk, skb, target); 123 124 /* If ok, return len. */ 125 return (err >= 0) ? len : err; 126 } 127 128 static int pn_recvmsg(struct kiocb *iocb, struct sock *sk, 129 struct msghdr *msg, size_t len, int noblock, 130 int flags, int *addr_len) 131 { 132 struct sk_buff *skb = NULL; 133 struct sockaddr_pn sa; 134 int rval = -EOPNOTSUPP; 135 int copylen; 136 137 if (flags & ~(MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_NOSIGNAL| 138 MSG_CMSG_COMPAT)) 139 goto out_nofree; 140 141 skb = skb_recv_datagram(sk, flags, noblock, &rval); 142 if (skb == NULL) 143 goto out_nofree; 144 145 pn_skb_get_src_sockaddr(skb, &sa); 146 147 copylen = skb->len; 148 if (len < copylen) { 149 msg->msg_flags |= MSG_TRUNC; 150 copylen = len; 151 } 152 153 rval = skb_copy_datagram_msg(skb, 0, msg, copylen); 154 if (rval) { 155 rval = -EFAULT; 156 goto out; 157 } 158 159 rval = (flags & MSG_TRUNC) ? skb->len : copylen; 160 161 if (msg->msg_name != NULL) { 162 __sockaddr_check_size(sizeof(sa)); 163 memcpy(msg->msg_name, &sa, sizeof(sa)); 164 *addr_len = sizeof(sa); 165 } 166 167 out: 168 skb_free_datagram(sk, skb); 169 170 out_nofree: 171 return rval; 172 } 173 174 /* Queue an skb for a sock. */ 175 static int pn_backlog_rcv(struct sock *sk, struct sk_buff *skb) 176 { 177 int err = sock_queue_rcv_skb(sk, skb); 178 179 if (err < 0) 180 kfree_skb(skb); 181 return err ? NET_RX_DROP : NET_RX_SUCCESS; 182 } 183 184 /* Module registration */ 185 static struct proto pn_proto = { 186 .close = pn_sock_close, 187 .ioctl = pn_ioctl, 188 .init = pn_init, 189 .sendmsg = pn_sendmsg, 190 .recvmsg = pn_recvmsg, 191 .backlog_rcv = pn_backlog_rcv, 192 .hash = pn_sock_hash, 193 .unhash = pn_sock_unhash, 194 .get_port = pn_sock_get_port, 195 .obj_size = sizeof(struct pn_sock), 196 .owner = THIS_MODULE, 197 .name = "PHONET", 198 }; 199 200 static struct phonet_protocol pn_dgram_proto = { 201 .ops = &phonet_dgram_ops, 202 .prot = &pn_proto, 203 .sock_type = SOCK_DGRAM, 204 }; 205 206 int __init isi_register(void) 207 { 208 return phonet_proto_register(PN_PROTO_PHONET, &pn_dgram_proto); 209 } 210 211 void __exit isi_unregister(void) 212 { 213 phonet_proto_unregister(PN_PROTO_PHONET, &pn_dgram_proto); 214 } 215