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linux/net/nfc/llcp_sock.c
David Howells cdfbabfb2f net: Work around lockdep limitation in sockets that use sockets 
Lockdep issues a circular dependency warning when AFS issues an operation
through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem.

The theory lockdep comes up with is as follows:

 (1) If the pagefault handler decides it needs to read pages from AFS, it
     calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but
     creating a call requires the socket lock:

	mmap_sem must be taken before sk_lock-AF_RXRPC

 (2) afs_open_socket() opens an AF_RXRPC socket and binds it.  rxrpc_bind()
     binds the underlying UDP socket whilst holding its socket lock.
     inet_bind() takes its own socket lock:

	sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET

 (3) Reading from a TCP socket into a userspace buffer might cause a fault
     and thus cause the kernel to take the mmap_sem, but the TCP socket is
     locked whilst doing this:

	sk_lock-AF_INET must be taken before mmap_sem

However, lockdep's theory is wrong in this instance because it deals only
with lock classes and not individual locks.  The AF_INET lock in (2) isn't
really equivalent to the AF_INET lock in (3) as the former deals with a
socket entirely internal to the kernel that never sees userspace.  This is
a limitation in the design of lockdep.

Fix the general case by:

 (1) Double up all the locking keys used in sockets so that one set are
     used if the socket is created by userspace and the other set is used
     if the socket is created by the kernel.

 (2) Store the kern parameter passed to sk_alloc() in a variable in the
     sock struct (sk_kern_sock).  This informs sock_lock_init(),
     sock_init_data() and sk_clone_lock() as to the lock keys to be used.

     Note that the child created by sk_clone_lock() inherits the parent's
     kern setting.

 (3) Add a 'kern' parameter to ->accept() that is analogous to the one
     passed in to ->create() that distinguishes whether kernel_accept() or
     sys_accept4() was the caller and can be passed to sk_alloc().

     Note that a lot of accept functions merely dequeue an already
     allocated socket.  I haven't touched these as the new socket already
     exists before we get the parameter.

     Note also that there are a couple of places where I've made the accepted
     socket unconditionally kernel-based:

	irda_accept()
	rds_rcp_accept_one()
	tcp_accept_from_sock()

     because they follow a sock_create_kern() and accept off of that.

Whilst creating this, I noticed that lustre and ocfs don't create sockets
through sock_create_kern() and thus they aren't marked as for-kernel,
though they appear to be internal.  I wonder if these should do that so
that they use the new set of lock keys.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-09 18:23:27 -08:00

1042 lines
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/*
* 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, see <http://www.gnu.org/licenses/>.
*/
#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 <linux/sched/signal.h>
#include "nfc.h"
#include "llcp.h"
static int sock_wait_state(struct sock *sk, int state, unsigned long timeo)
{
DECLARE_WAITQUEUE(wait, current);
int err = 0;
pr_debug("sk %p", sk);
add_wait_queue(sk_sleep(sk), &wait);
set_current_state(TASK_INTERRUPTIBLE);
while (sk->sk_state != state) {
if (!timeo) {
err = -EINPROGRESS;
break;
}
if (signal_pending(current)) {
err = sock_intr_errno(timeo);
break;
}
release_sock(sk);
timeo = schedule_timeout(timeo);
lock_sock(sk);
set_current_state(TASK_INTERRUPTIBLE);
err = sock_error(sk);
if (err)
break;
}
__set_current_state(TASK_RUNNING);
remove_wait_queue(sk_sleep(sk), &wait);
return err;
}
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;
if (!addr || addr->sa_family != AF_NFC)
return -EINVAL;
pr_debug("sk %p addr %p family %d\n", sk, addr, addr->sa_family);
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 = nfc_llcp_local_get(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_SAP_MAX) {
ret = -EADDRINUSE;
goto put_dev;
}
llcp_sock->reserved_ssap = llcp_sock->ssap;
nfc_llcp_sock_link(&local->sockets, sk);
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_raw_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;
if (!addr || addr->sa_family != AF_NFC)
return -EINVAL;
pr_debug("sk %p addr %p family %d\n", sk, addr, addr->sa_family);
memset(&llcp_addr, 0, sizeof(llcp_addr));
len = min_t(unsigned int, sizeof(llcp_addr), alen);
memcpy(&llcp_addr, addr, len);
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 = nfc_llcp_local_get(local);
llcp_sock->nfc_protocol = llcp_addr.nfc_protocol;
nfc_llcp_sock_link(&local->raw_sockets, sk);
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;
}
static int nfc_llcp_setsockopt(struct socket *sock, int level, int optname,
char __user *optval, unsigned int optlen)
{
struct sock *sk = sock->sk;
struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
u32 opt;
int err = 0;
pr_debug("%p optname %d\n", sk, optname);
if (level != SOL_NFC)
return -ENOPROTOOPT;
lock_sock(sk);
switch (optname) {
case NFC_LLCP_RW:
if (sk->sk_state == LLCP_CONNECTED ||
sk->sk_state == LLCP_BOUND ||
sk->sk_state == LLCP_LISTEN) {
err = -EINVAL;
break;
}
if (get_user(opt, (u32 __user *) optval)) {
err = -EFAULT;
break;
}
if (opt > LLCP_MAX_RW) {
err = -EINVAL;
break;
}
llcp_sock->rw = (u8) opt;
break;
case NFC_LLCP_MIUX:
if (sk->sk_state == LLCP_CONNECTED ||
sk->sk_state == LLCP_BOUND ||
sk->sk_state == LLCP_LISTEN) {
err = -EINVAL;
break;
}
if (get_user(opt, (u32 __user *) optval)) {
err = -EFAULT;
break;
}
if (opt > LLCP_MAX_MIUX) {
err = -EINVAL;
break;
}
llcp_sock->miux = cpu_to_be16((u16) opt);
break;
default:
err = -ENOPROTOOPT;
break;
}
release_sock(sk);
pr_debug("%p rw %d miux %d\n", llcp_sock,
llcp_sock->rw, llcp_sock->miux);
return err;
}
static int nfc_llcp_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen)
{
struct nfc_llcp_local *local;
struct sock *sk = sock->sk;
struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
int len, err = 0;
u16 miux, remote_miu;
u8 rw;
pr_debug("%p optname %d\n", sk, optname);
if (level != SOL_NFC)
return -ENOPROTOOPT;
if (get_user(len, optlen))
return -EFAULT;
local = llcp_sock->local;
if (!local)
return -ENODEV;
len = min_t(u32, len, sizeof(u32));
lock_sock(sk);
switch (optname) {
case NFC_LLCP_RW:
rw = llcp_sock->rw > LLCP_MAX_RW ? local->rw : llcp_sock->rw;
if (put_user(rw, (u32 __user *) optval))
err = -EFAULT;
break;
case NFC_LLCP_MIUX:
miux = be16_to_cpu(llcp_sock->miux) > LLCP_MAX_MIUX ?
be16_to_cpu(local->miux) : be16_to_cpu(llcp_sock->miux);
if (put_user(miux, (u32 __user *) optval))
err = -EFAULT;
break;
case NFC_LLCP_REMOTE_MIU:
remote_miu = llcp_sock->remote_miu > LLCP_MAX_MIU ?
local->remote_miu : llcp_sock->remote_miu;
if (put_user(remote_miu, (u32 __user *) optval))
err = -EFAULT;
break;
case NFC_LLCP_REMOTE_LTO:
if (put_user(local->remote_lto / 10, (u32 __user *) optval))
err = -EFAULT;
break;
case NFC_LLCP_REMOTE_RW:
if (put_user(llcp_sock->remote_rw, (u32 __user *) optval))
err = -EFAULT;
break;
default:
err = -ENOPROTOOPT;
break;
}
release_sock(sk);
if (put_user(len, optlen))
return -EFAULT;
return err;
}
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) {
list_del_init(&lsk->accept_queue);
sock_put(sk);
if (newsock)
sock_graft(sk, newsock);
release_sock(sk);
pr_debug("Returning sk state %d\n", sk->sk_state);
sk_acceptq_removed(parent);
return sk;
}
release_sock(sk);
}
return NULL;
}
static int llcp_sock_accept(struct socket *sock, struct socket *newsock,
int flags, bool kern)
{
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 *uaddr,
int *len, int peer)
{
struct sock *sk = sock->sk;
struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
DECLARE_SOCKADDR(struct sockaddr_nfc_llcp *, llcp_addr, uaddr);
if (llcp_sock == NULL || llcp_sock->dev == NULL)
return -EBADFD;
pr_debug("%p %d %d %d\n", sk, llcp_sock->target_idx,
llcp_sock->dsap, llcp_sock->ssap);
memset(llcp_addr, 0, sizeof(*llcp_addr));
*len = sizeof(struct sockaddr_nfc_llcp);
lock_sock(sk);
if (!llcp_sock->dev) {
release_sock(sk);
return -EBADFD;
}
llcp_addr->sa_family = AF_NFC;
llcp_addr->dev_idx = llcp_sock->dev->idx;
llcp_addr->target_idx = llcp_sock->target_idx;
llcp_addr->nfc_protocol = llcp_sock->nfc_protocol;
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);
release_sock(sk);
return 0;
}
static inline unsigned int llcp_accept_poll(struct sock *parent)
{
struct nfc_llcp_sock *llcp_sock, *parent_sock;
struct sock *sk;
parent_sock = nfc_llcp_sock(parent);
list_for_each_entry(llcp_sock, &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 |
(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0);
if (!skb_queue_empty(&sk->sk_receive_queue))
mask |= POLLIN | POLLRDNORM;
if (sk->sk_state == LLCP_CLOSED)
mask |= POLLHUP;
if (sk->sk_shutdown & RCV_SHUTDOWN)
mask |= POLLRDHUP | POLLIN | POLLRDNORM;
if (sk->sk_shutdown == SHUTDOWN_MASK)
mask |= POLLHUP;
if (sock_writeable(sk) && sk->sk_state == LLCP_CONNECTED)
mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
else
sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
pr_debug("mask 0x%x\n", mask);
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);
int err = 0;
if (!sk)
return 0;
pr_debug("%p\n", sk);
local = llcp_sock->local;
if (local == NULL) {
err = -ENODEV;
goto out;
}
lock_sock(sk);
/* Send a DISC */
if (sk->sk_state == LLCP_CONNECTED)
nfc_llcp_send_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_send_disconnect(lsk);
nfc_llcp_accept_unlink(accept_sk);
release_sock(accept_sk);
}
}
if (llcp_sock->reserved_ssap < LLCP_SAP_MAX)
nfc_llcp_put_ssap(llcp_sock->local, llcp_sock->ssap);
release_sock(sk);
/* Keep this sock alive and therefore do not remove it from the sockets
* list until the DISC PDU has been actually sent. Otherwise we would
* reply with DM PDUs before sending the DISC one.
*/
if (sk->sk_state == LLCP_DISCONNECTING)
return err;
if (sock->type == SOCK_RAW)
nfc_llcp_sock_unlink(&local->raw_sockets, sk);
else
nfc_llcp_sock_unlink(&local->sockets, sk);
out:
sock_orphan(sk);
sock_put(sk);
return err;
}
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)
return -EINVAL;
if (addr->service_name_len == 0 && addr->dsap == 0)
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 = nfc_llcp_local_get(local);
llcp_sock->ssap = nfc_llcp_get_local_ssap(local);
if (llcp_sock->ssap == LLCP_SAP_MAX) {
ret = -ENOMEM;
goto put_dev;
}
llcp_sock->reserved_ssap = llcp_sock->ssap;
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);
nfc_llcp_sock_link(&local->connecting_sockets, sk);
ret = nfc_llcp_send_connect(llcp_sock);
if (ret)
goto sock_unlink;
sk->sk_state = LLCP_CONNECTING;
ret = sock_wait_state(sk, LLCP_CONNECTED,
sock_sndtimeo(sk, flags & O_NONBLOCK));
if (ret && ret != -EINPROGRESS)
goto sock_unlink;
release_sock(sk);
return ret;
sock_unlink:
nfc_llcp_put_ssap(local, llcp_sock->ssap);
nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
put_dev:
nfc_put_device(dev);
error:
release_sock(sk);
return ret;
}
static int llcp_sock_sendmsg(struct socket *sock, struct msghdr *msg,
size_t len)
{
struct sock *sk = sock->sk;
struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
int ret;
pr_debug("sock %p sk %p", sock, sk);
ret = sock_error(sk);
if (ret)
return ret;
if (msg->msg_flags & MSG_OOB)
return -EOPNOTSUPP;
lock_sock(sk);
if (sk->sk_type == SOCK_DGRAM) {
DECLARE_SOCKADDR(struct sockaddr_nfc_llcp *, addr,
msg->msg_name);
if (msg->msg_namelen < sizeof(*addr)) {
release_sock(sk);
return -EINVAL;
}
release_sock(sk);
return nfc_llcp_send_ui_frame(llcp_sock, addr->dsap, addr->ssap,
msg, len);
}
if (sk->sk_state != LLCP_CONNECTED) {
release_sock(sk);
return -ENOTCONN;
}
release_sock(sk);
return nfc_llcp_send_i_frame(llcp_sock, msg, len);
}
static int llcp_sock_recvmsg(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 (skb_copy_datagram_msg(cskb, 0, msg, copied)) {
if (!(flags & MSG_PEEK))
skb_queue_head(&sk->sk_receive_queue, skb);
return -EFAULT;
}
sock_recv_timestamp(msg, sk, skb);
if (sk->sk_type == SOCK_DGRAM && msg->msg_name) {
struct nfc_llcp_ui_cb *ui_cb = nfc_llcp_ui_skb_cb(skb);
DECLARE_SOCKADDR(struct sockaddr_nfc_llcp *, sockaddr,
msg->msg_name);
msg->msg_namelen = sizeof(struct sockaddr_nfc_llcp);
pr_debug("Datagram socket %d %d\n", ui_cb->dsap, ui_cb->ssap);
memset(sockaddr, 0, sizeof(*sockaddr));
sockaddr->sa_family = AF_NFC;
sockaddr->nfc_protocol = NFC_PROTO_NFC_DEP;
sockaddr->dsap = ui_cb->dsap;
sockaddr->ssap = ui_cb->ssap;
}
/* 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 ||
sk->sk_type == SOCK_DGRAM ||
sk->sk_type == SOCK_RAW) {
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 = nfc_llcp_setsockopt,
.getsockopt = nfc_llcp_getsockopt,
.sendmsg = llcp_sock_sendmsg,
.recvmsg = llcp_sock_recvmsg,
.mmap = sock_no_mmap,
};
static const struct proto_ops llcp_rawsock_ops = {
.family = PF_NFC,
.owner = THIS_MODULE,
.bind = llcp_raw_sock_bind,
.connect = sock_no_connect,
.release = llcp_sock_release,
.socketpair = sock_no_socketpair,
.accept = sock_no_accept,
.getname = llcp_sock_getname,
.poll = llcp_sock_poll,
.ioctl = sock_no_ioctl,
.listen = sock_no_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, int kern)
{
struct sock *sk;
struct nfc_llcp_sock *llcp_sock;
sk = sk_alloc(&init_net, PF_NFC, gfp, &llcp_sock_proto, kern);
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->rw = LLCP_MAX_RW + 1;
llcp_sock->miux = cpu_to_be16(LLCP_MAX_MIUX + 1);
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;
llcp_sock->reserved_ssap = LLCP_SAP_MAX;
nfc_llcp_socket_remote_param_init(llcp_sock);
skb_queue_head_init(&llcp_sock->tx_queue);
skb_queue_head_init(&llcp_sock->tx_pending_queue);
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);
list_del_init(&sock->accept_queue);
sock->parent = NULL;
nfc_llcp_local_put(sock->local);
}
static int llcp_sock_create(struct net *net, struct socket *sock,
const struct nfc_protocol *nfc_proto, int kern)
{
struct sock *sk;
pr_debug("%p\n", sock);
if (sock->type != SOCK_STREAM &&
sock->type != SOCK_DGRAM &&
sock->type != SOCK_RAW)
return -ESOCKTNOSUPPORT;
if (sock->type == SOCK_RAW)
sock->ops = &llcp_rawsock_ops;
else
sock->ops = &llcp_sock_ops;
sk = nfc_llcp_sock_alloc(sock, sock->type, GFP_ATOMIC, kern);
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);
}
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