linux/net/nfc/llcp/sock.c
Samuel Ortiz d646960f79 NFC: Initial LLCP support
This patch is an initial implementation for the NFC Logical Link Control
protocol. It's also known as NFC peer to peer mode.
This is a basic implementation as it lacks SDP (services Discovery
Protocol), frames aggregation support, and frame rejecion parsing.
Follow up patches will implement those missing features.
This code has been tested against a Nexus S phone implementing LLCP 1.0.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-12-14 14:50:13 -05:00

676 lines
15 KiB
C

/*
* Copyright (C) 2011 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the
* Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#define pr_fmt(fmt) "llcp: %s: " fmt, __func__
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/nfc.h>
#include "../nfc.h"
#include "llcp.h"
static struct proto llcp_sock_proto = {
.name = "NFC_LLCP",
.owner = THIS_MODULE,
.obj_size = sizeof(struct nfc_llcp_sock),
};
static int llcp_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
{
struct sock *sk = sock->sk;
struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
struct nfc_llcp_local *local;
struct nfc_dev *dev;
struct sockaddr_nfc_llcp llcp_addr;
int len, ret = 0;
pr_debug("sk %p addr %p family %d\n", sk, addr, addr->sa_family);
if (!addr || addr->sa_family != AF_NFC)
return -EINVAL;
memset(&llcp_addr, 0, sizeof(llcp_addr));
len = min_t(unsigned int, sizeof(llcp_addr), alen);
memcpy(&llcp_addr, addr, len);
/* This is going to be a listening socket, dsap must be 0 */
if (llcp_addr.dsap != 0)
return -EINVAL;
lock_sock(sk);
if (sk->sk_state != LLCP_CLOSED) {
ret = -EBADFD;
goto error;
}
dev = nfc_get_device(llcp_addr.dev_idx);
if (dev == NULL) {
ret = -ENODEV;
goto error;
}
local = nfc_llcp_find_local(dev);
if (local == NULL) {
ret = -ENODEV;
goto put_dev;
}
llcp_sock->dev = dev;
llcp_sock->local = local;
llcp_sock->nfc_protocol = llcp_addr.nfc_protocol;
llcp_sock->service_name_len = min_t(unsigned int,
llcp_addr.service_name_len, NFC_LLCP_MAX_SERVICE_NAME);
llcp_sock->service_name = kmemdup(llcp_addr.service_name,
llcp_sock->service_name_len, GFP_KERNEL);
llcp_sock->ssap = nfc_llcp_get_sdp_ssap(local, llcp_sock);
if (llcp_sock->ssap == LLCP_MAX_SAP)
goto put_dev;
local->sockets[llcp_sock->ssap] = llcp_sock;
pr_debug("Socket bound to SAP %d\n", llcp_sock->ssap);
sk->sk_state = LLCP_BOUND;
put_dev:
nfc_put_device(dev);
error:
release_sock(sk);
return ret;
}
static int llcp_sock_listen(struct socket *sock, int backlog)
{
struct sock *sk = sock->sk;
int ret = 0;
pr_debug("sk %p backlog %d\n", sk, backlog);
lock_sock(sk);
if ((sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM)
|| sk->sk_state != LLCP_BOUND) {
ret = -EBADFD;
goto error;
}
sk->sk_max_ack_backlog = backlog;
sk->sk_ack_backlog = 0;
pr_debug("Socket listening\n");
sk->sk_state = LLCP_LISTEN;
error:
release_sock(sk);
return ret;
}
void nfc_llcp_accept_unlink(struct sock *sk)
{
struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
pr_debug("state %d\n", sk->sk_state);
list_del_init(&llcp_sock->accept_queue);
sk_acceptq_removed(llcp_sock->parent);
llcp_sock->parent = NULL;
sock_put(sk);
}
void nfc_llcp_accept_enqueue(struct sock *parent, struct sock *sk)
{
struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
struct nfc_llcp_sock *llcp_sock_parent = nfc_llcp_sock(parent);
/* Lock will be free from unlink */
sock_hold(sk);
list_add_tail(&llcp_sock->accept_queue,
&llcp_sock_parent->accept_queue);
llcp_sock->parent = parent;
sk_acceptq_added(parent);
}
struct sock *nfc_llcp_accept_dequeue(struct sock *parent,
struct socket *newsock)
{
struct nfc_llcp_sock *lsk, *n, *llcp_parent;
struct sock *sk;
llcp_parent = nfc_llcp_sock(parent);
list_for_each_entry_safe(lsk, n, &llcp_parent->accept_queue,
accept_queue) {
sk = &lsk->sk;
lock_sock(sk);
if (sk->sk_state == LLCP_CLOSED) {
release_sock(sk);
nfc_llcp_accept_unlink(sk);
continue;
}
if (sk->sk_state == LLCP_CONNECTED || !newsock) {
nfc_llcp_accept_unlink(sk);
if (newsock)
sock_graft(sk, newsock);
release_sock(sk);
pr_debug("Returning sk state %d\n", sk->sk_state);
return sk;
}
release_sock(sk);
}
return NULL;
}
static int llcp_sock_accept(struct socket *sock, struct socket *newsock,
int flags)
{
DECLARE_WAITQUEUE(wait, current);
struct sock *sk = sock->sk, *new_sk;
long timeo;
int ret = 0;
pr_debug("parent %p\n", sk);
lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
if (sk->sk_state != LLCP_LISTEN) {
ret = -EBADFD;
goto error;
}
timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
/* Wait for an incoming connection. */
add_wait_queue_exclusive(sk_sleep(sk), &wait);
while (!(new_sk = nfc_llcp_accept_dequeue(sk, newsock))) {
set_current_state(TASK_INTERRUPTIBLE);
if (!timeo) {
ret = -EAGAIN;
break;
}
if (signal_pending(current)) {
ret = sock_intr_errno(timeo);
break;
}
release_sock(sk);
timeo = schedule_timeout(timeo);
lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
}
__set_current_state(TASK_RUNNING);
remove_wait_queue(sk_sleep(sk), &wait);
if (ret)
goto error;
newsock->state = SS_CONNECTED;
pr_debug("new socket %p\n", new_sk);
error:
release_sock(sk);
return ret;
}
static int llcp_sock_getname(struct socket *sock, struct sockaddr *addr,
int *len, int peer)
{
struct sockaddr_nfc_llcp *llcp_addr = (struct sockaddr_nfc_llcp *) addr;
struct sock *sk = sock->sk;
struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
pr_debug("%p\n", sk);
addr->sa_family = AF_NFC;
*len = sizeof(struct sockaddr_nfc_llcp);
llcp_addr->dev_idx = llcp_sock->dev->idx;
llcp_addr->dsap = llcp_sock->dsap;
llcp_addr->ssap = llcp_sock->ssap;
llcp_addr->service_name_len = llcp_sock->service_name_len;
memcpy(llcp_addr->service_name, llcp_sock->service_name,
llcp_addr->service_name_len);
return 0;
}
static inline unsigned int llcp_accept_poll(struct sock *parent)
{
struct nfc_llcp_sock *llcp_sock, *n, *parent_sock;
struct sock *sk;
parent_sock = nfc_llcp_sock(parent);
list_for_each_entry_safe(llcp_sock, n, &parent_sock->accept_queue,
accept_queue) {
sk = &llcp_sock->sk;
if (sk->sk_state == LLCP_CONNECTED)
return POLLIN | POLLRDNORM;
}
return 0;
}
static unsigned int llcp_sock_poll(struct file *file, struct socket *sock,
poll_table *wait)
{
struct sock *sk = sock->sk;
unsigned int mask = 0;
pr_debug("%p\n", sk);
sock_poll_wait(file, sk_sleep(sk), wait);
if (sk->sk_state == LLCP_LISTEN)
return llcp_accept_poll(sk);
if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
mask |= POLLERR;
if (!skb_queue_empty(&sk->sk_receive_queue))
mask |= POLLIN;
if (sk->sk_state == LLCP_CLOSED)
mask |= POLLHUP;
return mask;
}
static int llcp_sock_release(struct socket *sock)
{
struct sock *sk = sock->sk;
struct nfc_llcp_local *local;
struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
if (!sk)
return 0;
pr_debug("%p\n", sk);
local = llcp_sock->local;
if (local == NULL)
return -ENODEV;
mutex_lock(&local->socket_lock);
if (llcp_sock == local->sockets[llcp_sock->ssap]) {
local->sockets[llcp_sock->ssap] = NULL;
} else {
struct nfc_llcp_sock *parent, *s, *n;
parent = local->sockets[llcp_sock->ssap];
list_for_each_entry_safe(s, n, &parent->list, list)
if (llcp_sock == s) {
list_del(&s->list);
break;
}
}
mutex_unlock(&local->socket_lock);
lock_sock(sk);
/* Send a DISC */
if (sk->sk_state == LLCP_CONNECTED)
nfc_llcp_disconnect(llcp_sock);
if (sk->sk_state == LLCP_LISTEN) {
struct nfc_llcp_sock *lsk, *n;
struct sock *accept_sk;
list_for_each_entry_safe(lsk, n, &llcp_sock->accept_queue,
accept_queue) {
accept_sk = &lsk->sk;
lock_sock(accept_sk);
nfc_llcp_disconnect(lsk);
nfc_llcp_accept_unlink(accept_sk);
release_sock(accept_sk);
sock_set_flag(sk, SOCK_DEAD);
sock_orphan(accept_sk);
sock_put(accept_sk);
}
}
/* Freeing the SAP */
if ((sk->sk_state == LLCP_CONNECTED
&& llcp_sock->ssap > LLCP_LOCAL_SAP_OFFSET) ||
sk->sk_state == LLCP_BOUND ||
sk->sk_state == LLCP_LISTEN)
nfc_llcp_put_ssap(llcp_sock->local, llcp_sock->ssap);
sock_set_flag(sk, SOCK_DEAD);
release_sock(sk);
sock_orphan(sk);
sock_put(sk);
return 0;
}
static int llcp_sock_connect(struct socket *sock, struct sockaddr *_addr,
int len, int flags)
{
struct sock *sk = sock->sk;
struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
struct sockaddr_nfc_llcp *addr = (struct sockaddr_nfc_llcp *)_addr;
struct nfc_dev *dev;
struct nfc_llcp_local *local;
int ret = 0;
pr_debug("sock %p sk %p flags 0x%x\n", sock, sk, flags);
if (!addr || len < sizeof(struct sockaddr_nfc) ||
addr->sa_family != AF_NFC) {
pr_err("Invalid socket\n");
return -EINVAL;
}
if (addr->service_name_len == 0 && addr->dsap == 0) {
pr_err("Missing service name or dsap\n");
return -EINVAL;
}
pr_debug("addr dev_idx=%u target_idx=%u protocol=%u\n", addr->dev_idx,
addr->target_idx, addr->nfc_protocol);
lock_sock(sk);
if (sk->sk_state == LLCP_CONNECTED) {
ret = -EISCONN;
goto error;
}
dev = nfc_get_device(addr->dev_idx);
if (dev == NULL) {
ret = -ENODEV;
goto error;
}
local = nfc_llcp_find_local(dev);
if (local == NULL) {
ret = -ENODEV;
goto put_dev;
}
device_lock(&dev->dev);
if (dev->dep_link_up == false) {
ret = -ENOLINK;
device_unlock(&dev->dev);
goto put_dev;
}
device_unlock(&dev->dev);
if (local->rf_mode == NFC_RF_INITIATOR &&
addr->target_idx != local->target_idx) {
ret = -ENOLINK;
goto put_dev;
}
llcp_sock->dev = dev;
llcp_sock->local = local;
llcp_sock->ssap = nfc_llcp_get_local_ssap(local);
if (llcp_sock->ssap == LLCP_SAP_MAX) {
ret = -ENOMEM;
goto put_dev;
}
if (addr->service_name_len == 0)
llcp_sock->dsap = addr->dsap;
else
llcp_sock->dsap = LLCP_SAP_SDP;
llcp_sock->nfc_protocol = addr->nfc_protocol;
llcp_sock->service_name_len = min_t(unsigned int,
addr->service_name_len, NFC_LLCP_MAX_SERVICE_NAME);
llcp_sock->service_name = kmemdup(addr->service_name,
llcp_sock->service_name_len, GFP_KERNEL);
local->sockets[llcp_sock->ssap] = llcp_sock;
ret = nfc_llcp_send_connect(llcp_sock);
if (ret)
goto put_dev;
sk->sk_state = LLCP_CONNECTED;
release_sock(sk);
return 0;
put_dev:
nfc_put_device(dev);
error:
release_sock(sk);
return ret;
}
static int llcp_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t len, int flags)
{
int noblock = flags & MSG_DONTWAIT;
struct sock *sk = sock->sk;
unsigned int copied, rlen;
struct sk_buff *skb, *cskb;
int err = 0;
pr_debug("%p %zu\n", sk, len);
lock_sock(sk);
if (sk->sk_state == LLCP_CLOSED &&
skb_queue_empty(&sk->sk_receive_queue)) {
release_sock(sk);
return 0;
}
release_sock(sk);
if (flags & (MSG_OOB))
return -EOPNOTSUPP;
skb = skb_recv_datagram(sk, flags, noblock, &err);
if (!skb) {
pr_err("Recv datagram failed state %d %d %d",
sk->sk_state, err, sock_error(sk));
if (sk->sk_shutdown & RCV_SHUTDOWN)
return 0;
return err;
}
rlen = skb->len; /* real length of skb */
copied = min_t(unsigned int, rlen, len);
cskb = skb;
if (memcpy_toiovec(msg->msg_iov, cskb->data, copied)) {
if (!(flags & MSG_PEEK))
skb_queue_head(&sk->sk_receive_queue, skb);
return -EFAULT;
}
/* Mark read part of skb as used */
if (!(flags & MSG_PEEK)) {
/* SOCK_STREAM: re-queue skb if it contains unreceived data */
if (sk->sk_type == SOCK_STREAM) {
skb_pull(skb, copied);
if (skb->len) {
skb_queue_head(&sk->sk_receive_queue, skb);
goto done;
}
}
kfree_skb(skb);
}
/* XXX Queue backlogged skbs */
done:
/* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
copied = rlen;
return copied;
}
static const struct proto_ops llcp_sock_ops = {
.family = PF_NFC,
.owner = THIS_MODULE,
.bind = llcp_sock_bind,
.connect = llcp_sock_connect,
.release = llcp_sock_release,
.socketpair = sock_no_socketpair,
.accept = llcp_sock_accept,
.getname = llcp_sock_getname,
.poll = llcp_sock_poll,
.ioctl = sock_no_ioctl,
.listen = llcp_sock_listen,
.shutdown = sock_no_shutdown,
.setsockopt = sock_no_setsockopt,
.getsockopt = sock_no_getsockopt,
.sendmsg = sock_no_sendmsg,
.recvmsg = llcp_sock_recvmsg,
.mmap = sock_no_mmap,
};
static void llcp_sock_destruct(struct sock *sk)
{
struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
pr_debug("%p\n", sk);
if (sk->sk_state == LLCP_CONNECTED)
nfc_put_device(llcp_sock->dev);
skb_queue_purge(&sk->sk_receive_queue);
nfc_llcp_sock_free(llcp_sock);
if (!sock_flag(sk, SOCK_DEAD)) {
pr_err("Freeing alive NFC LLCP socket %p\n", sk);
return;
}
}
struct sock *nfc_llcp_sock_alloc(struct socket *sock, int type, gfp_t gfp)
{
struct sock *sk;
struct nfc_llcp_sock *llcp_sock;
sk = sk_alloc(&init_net, PF_NFC, gfp, &llcp_sock_proto);
if (!sk)
return NULL;
llcp_sock = nfc_llcp_sock(sk);
sock_init_data(sock, sk);
sk->sk_state = LLCP_CLOSED;
sk->sk_protocol = NFC_SOCKPROTO_LLCP;
sk->sk_type = type;
sk->sk_destruct = llcp_sock_destruct;
llcp_sock->ssap = 0;
llcp_sock->dsap = LLCP_SAP_SDP;
llcp_sock->send_n = llcp_sock->send_ack_n = 0;
llcp_sock->recv_n = llcp_sock->recv_ack_n = 0;
llcp_sock->remote_ready = 1;
skb_queue_head_init(&llcp_sock->tx_queue);
skb_queue_head_init(&llcp_sock->tx_pending_queue);
skb_queue_head_init(&llcp_sock->tx_backlog_queue);
INIT_LIST_HEAD(&llcp_sock->list);
INIT_LIST_HEAD(&llcp_sock->accept_queue);
if (sock != NULL)
sock->state = SS_UNCONNECTED;
return sk;
}
void nfc_llcp_sock_free(struct nfc_llcp_sock *sock)
{
kfree(sock->service_name);
skb_queue_purge(&sock->tx_queue);
skb_queue_purge(&sock->tx_pending_queue);
skb_queue_purge(&sock->tx_backlog_queue);
list_del_init(&sock->accept_queue);
sock->parent = NULL;
}
static int llcp_sock_create(struct net *net, struct socket *sock,
const struct nfc_protocol *nfc_proto)
{
struct sock *sk;
pr_debug("%p\n", sock);
if (sock->type != SOCK_STREAM && sock->type != SOCK_DGRAM)
return -ESOCKTNOSUPPORT;
sock->ops = &llcp_sock_ops;
sk = nfc_llcp_sock_alloc(sock, sock->type, GFP_ATOMIC);
if (sk == NULL)
return -ENOMEM;
return 0;
}
static const struct nfc_protocol llcp_nfc_proto = {
.id = NFC_SOCKPROTO_LLCP,
.proto = &llcp_sock_proto,
.owner = THIS_MODULE,
.create = llcp_sock_create
};
int __init nfc_llcp_sock_init(void)
{
return nfc_proto_register(&llcp_nfc_proto);
}
void nfc_llcp_sock_exit(void)
{
nfc_proto_unregister(&llcp_nfc_proto);
}