1 /* 2 * File: datagram.c 3 * 4 * Datagram (ISI) Phonet sockets 5 * 6 * Copyright (C) 2008 Nokia Corporation. 7 * 8 * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com> 9 * Original author: Sakari Ailus <sakari.ailus@nokia.com> 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 <net/phonet/phonet.h> 34 35 static int pn_backlog_rcv(struct sock *sk, struct sk_buff *skb); 36 37 /* associated socket ceases to exist */ 38 static void pn_sock_close(struct sock *sk, long timeout) 39 { 40 sk_common_release(sk); 41 } 42 43 static int pn_ioctl(struct sock *sk, int cmd, unsigned long arg) 44 { 45 struct sk_buff *skb; 46 int answ; 47 48 switch (cmd) { 49 case SIOCINQ: 50 lock_sock(sk); 51 skb = skb_peek(&sk->sk_receive_queue); 52 answ = skb ? skb->len : 0; 53 release_sock(sk); 54 return put_user(answ, (int __user *)arg); 55 } 56 57 return -ENOIOCTLCMD; 58 } 59 60 /* Destroy socket. All references are gone. */ 61 static void pn_destruct(struct sock *sk) 62 { 63 skb_queue_purge(&sk->sk_receive_queue); 64 } 65 66 static int pn_init(struct sock *sk) 67 { 68 sk->sk_destruct = pn_destruct; 69 return 0; 70 } 71 72 static int pn_sendmsg(struct kiocb *iocb, struct sock *sk, 73 struct msghdr *msg, size_t len) 74 { 75 struct sockaddr_pn *target; 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 (msg->msg_name == NULL) 84 return -EDESTADDRREQ; 85 86 if (msg->msg_namelen < sizeof(struct sockaddr_pn)) 87 return -EINVAL; 88 89 target = (struct sockaddr_pn *)msg->msg_name; 90 if (target->spn_family != AF_PHONET) 91 return -EAFNOSUPPORT; 92 93 skb = sock_alloc_send_skb(sk, MAX_PHONET_HEADER + len, 94 msg->msg_flags & MSG_DONTWAIT, &err); 95 if (skb == NULL) 96 return err; 97 skb_reserve(skb, MAX_PHONET_HEADER); 98 99 err = memcpy_fromiovec((void *)skb_put(skb, len), msg->msg_iov, len); 100 if (err < 0) { 101 kfree_skb(skb); 102 return err; 103 } 104 105 /* 106 * Fill in the Phonet header and 107 * finally pass the packet forwards. 108 */ 109 err = pn_skb_send(sk, skb, target); 110 111 /* If ok, return len. */ 112 return (err >= 0) ? len : err; 113 } 114 115 static int pn_recvmsg(struct kiocb *iocb, struct sock *sk, 116 struct msghdr *msg, size_t len, int noblock, 117 int flags, int *addr_len) 118 { 119 struct sk_buff *skb = NULL; 120 struct sockaddr_pn sa; 121 int rval = -EOPNOTSUPP; 122 int copylen; 123 124 if (flags & ~(MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_NOSIGNAL| 125 MSG_CMSG_COMPAT)) 126 goto out_nofree; 127 128 if (addr_len) 129 *addr_len = sizeof(sa); 130 131 skb = skb_recv_datagram(sk, flags, noblock, &rval); 132 if (skb == NULL) 133 goto out_nofree; 134 135 pn_skb_get_src_sockaddr(skb, &sa); 136 137 copylen = skb->len; 138 if (len < copylen) { 139 msg->msg_flags |= MSG_TRUNC; 140 copylen = len; 141 } 142 143 rval = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copylen); 144 if (rval) { 145 rval = -EFAULT; 146 goto out; 147 } 148 149 rval = (flags & MSG_TRUNC) ? skb->len : copylen; 150 151 if (msg->msg_name != NULL) 152 memcpy(msg->msg_name, &sa, sizeof(struct sockaddr_pn)); 153 154 out: 155 skb_free_datagram(sk, skb); 156 157 out_nofree: 158 return rval; 159 } 160 161 /* Queue an skb for a sock. */ 162 static int pn_backlog_rcv(struct sock *sk, struct sk_buff *skb) 163 { 164 int err = sock_queue_rcv_skb(sk, skb); 165 166 if (err < 0) 167 kfree_skb(skb); 168 return err ? NET_RX_DROP : NET_RX_SUCCESS; 169 } 170 171 /* Module registration */ 172 static struct proto pn_proto = { 173 .close = pn_sock_close, 174 .ioctl = pn_ioctl, 175 .init = pn_init, 176 .sendmsg = pn_sendmsg, 177 .recvmsg = pn_recvmsg, 178 .backlog_rcv = pn_backlog_rcv, 179 .hash = pn_sock_hash, 180 .unhash = pn_sock_unhash, 181 .get_port = pn_sock_get_port, 182 .obj_size = sizeof(struct pn_sock), 183 .owner = THIS_MODULE, 184 .name = "PHONET", 185 }; 186 187 static struct phonet_protocol pn_dgram_proto = { 188 .ops = &phonet_dgram_ops, 189 .prot = &pn_proto, 190 .sock_type = SOCK_DGRAM, 191 }; 192 193 int __init isi_register(void) 194 { 195 return phonet_proto_register(PN_PROTO_PHONET, &pn_dgram_proto); 196 } 197 198 void __exit isi_unregister(void) 199 { 200 phonet_proto_unregister(PN_PROTO_PHONET, &pn_dgram_proto); 201 } 202