diff options
Diffstat (limited to 'net/nfc/rawsock.c')
-rw-r--r-- | net/nfc/rawsock.c | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/net/nfc/rawsock.c b/net/nfc/rawsock.c new file mode 100644 index 000000000..8dd569765 --- /dev/null +++ b/net/nfc/rawsock.c @@ -0,0 +1,418 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2011 Instituto Nokia de Tecnologia + * + * Authors: + * Aloisio Almeida Jr <aloisio.almeida@openbossa.org> + * Lauro Ramos Venancio <lauro.venancio@openbossa.org> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__ + +#include <net/tcp_states.h> +#include <linux/nfc.h> +#include <linux/export.h> + +#include "nfc.h" + +static struct nfc_sock_list raw_sk_list = { + .lock = __RW_LOCK_UNLOCKED(raw_sk_list.lock) +}; + +static void nfc_sock_link(struct nfc_sock_list *l, struct sock *sk) +{ + write_lock(&l->lock); + sk_add_node(sk, &l->head); + write_unlock(&l->lock); +} + +static void nfc_sock_unlink(struct nfc_sock_list *l, struct sock *sk) +{ + write_lock(&l->lock); + sk_del_node_init(sk); + write_unlock(&l->lock); +} + +static void rawsock_write_queue_purge(struct sock *sk) +{ + pr_debug("sk=%p\n", sk); + + spin_lock_bh(&sk->sk_write_queue.lock); + __skb_queue_purge(&sk->sk_write_queue); + nfc_rawsock(sk)->tx_work_scheduled = false; + spin_unlock_bh(&sk->sk_write_queue.lock); +} + +static void rawsock_report_error(struct sock *sk, int err) +{ + pr_debug("sk=%p err=%d\n", sk, err); + + sk->sk_shutdown = SHUTDOWN_MASK; + sk->sk_err = -err; + sk_error_report(sk); + + rawsock_write_queue_purge(sk); +} + +static int rawsock_release(struct socket *sock) +{ + struct sock *sk = sock->sk; + + pr_debug("sock=%p sk=%p\n", sock, sk); + + if (!sk) + return 0; + + if (sock->type == SOCK_RAW) + nfc_sock_unlink(&raw_sk_list, sk); + + sock_orphan(sk); + sock_put(sk); + + return 0; +} + +static int rawsock_connect(struct socket *sock, struct sockaddr *_addr, + int len, int flags) +{ + struct sock *sk = sock->sk; + struct sockaddr_nfc *addr = (struct sockaddr_nfc *)_addr; + struct nfc_dev *dev; + int rc = 0; + + pr_debug("sock=%p sk=%p flags=%d\n", sock, sk, flags); + + if (!addr || len < sizeof(struct sockaddr_nfc) || + addr->sa_family != AF_NFC) + 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 (sock->state == SS_CONNECTED) { + rc = -EISCONN; + goto error; + } + + dev = nfc_get_device(addr->dev_idx); + if (!dev) { + rc = -ENODEV; + goto error; + } + + if (addr->target_idx > dev->target_next_idx - 1 || + addr->target_idx < dev->target_next_idx - dev->n_targets) { + rc = -EINVAL; + goto put_dev; + } + + rc = nfc_activate_target(dev, addr->target_idx, addr->nfc_protocol); + if (rc) + goto put_dev; + + nfc_rawsock(sk)->dev = dev; + nfc_rawsock(sk)->target_idx = addr->target_idx; + sock->state = SS_CONNECTED; + sk->sk_state = TCP_ESTABLISHED; + sk->sk_state_change(sk); + + release_sock(sk); + return 0; + +put_dev: + nfc_put_device(dev); +error: + release_sock(sk); + return rc; +} + +static int rawsock_add_header(struct sk_buff *skb) +{ + *(u8 *)skb_push(skb, NFC_HEADER_SIZE) = 0; + + return 0; +} + +static void rawsock_data_exchange_complete(void *context, struct sk_buff *skb, + int err) +{ + struct sock *sk = (struct sock *) context; + + BUG_ON(in_hardirq()); + + pr_debug("sk=%p err=%d\n", sk, err); + + if (err) + goto error; + + err = rawsock_add_header(skb); + if (err) + goto error_skb; + + err = sock_queue_rcv_skb(sk, skb); + if (err) + goto error_skb; + + spin_lock_bh(&sk->sk_write_queue.lock); + if (!skb_queue_empty(&sk->sk_write_queue)) + schedule_work(&nfc_rawsock(sk)->tx_work); + else + nfc_rawsock(sk)->tx_work_scheduled = false; + spin_unlock_bh(&sk->sk_write_queue.lock); + + sock_put(sk); + return; + +error_skb: + kfree_skb(skb); + +error: + rawsock_report_error(sk, err); + sock_put(sk); +} + +static void rawsock_tx_work(struct work_struct *work) +{ + struct sock *sk = to_rawsock_sk(work); + struct nfc_dev *dev = nfc_rawsock(sk)->dev; + u32 target_idx = nfc_rawsock(sk)->target_idx; + struct sk_buff *skb; + int rc; + + pr_debug("sk=%p target_idx=%u\n", sk, target_idx); + + if (sk->sk_shutdown & SEND_SHUTDOWN) { + rawsock_write_queue_purge(sk); + return; + } + + skb = skb_dequeue(&sk->sk_write_queue); + + sock_hold(sk); + rc = nfc_data_exchange(dev, target_idx, skb, + rawsock_data_exchange_complete, sk); + if (rc) { + rawsock_report_error(sk, rc); + sock_put(sk); + } +} + +static int rawsock_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) +{ + struct sock *sk = sock->sk; + struct nfc_dev *dev = nfc_rawsock(sk)->dev; + struct sk_buff *skb; + int rc; + + pr_debug("sock=%p sk=%p len=%zu\n", sock, sk, len); + + if (msg->msg_namelen) + return -EOPNOTSUPP; + + if (sock->state != SS_CONNECTED) + return -ENOTCONN; + + skb = nfc_alloc_send_skb(dev, sk, msg->msg_flags, len, &rc); + if (skb == NULL) + return rc; + + rc = memcpy_from_msg(skb_put(skb, len), msg, len); + if (rc < 0) { + kfree_skb(skb); + return rc; + } + + spin_lock_bh(&sk->sk_write_queue.lock); + __skb_queue_tail(&sk->sk_write_queue, skb); + if (!nfc_rawsock(sk)->tx_work_scheduled) { + schedule_work(&nfc_rawsock(sk)->tx_work); + nfc_rawsock(sk)->tx_work_scheduled = true; + } + spin_unlock_bh(&sk->sk_write_queue.lock); + + return len; +} + +static int rawsock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, + int flags) +{ + struct sock *sk = sock->sk; + struct sk_buff *skb; + int copied; + int rc; + + pr_debug("sock=%p sk=%p len=%zu flags=%d\n", sock, sk, len, flags); + + skb = skb_recv_datagram(sk, flags, &rc); + if (!skb) + return rc; + + copied = skb->len; + if (len < copied) { + msg->msg_flags |= MSG_TRUNC; + copied = len; + } + + rc = skb_copy_datagram_msg(skb, 0, msg, copied); + + skb_free_datagram(sk, skb); + + return rc ? : copied; +} + +static const struct proto_ops rawsock_ops = { + .family = PF_NFC, + .owner = THIS_MODULE, + .release = rawsock_release, + .bind = sock_no_bind, + .connect = rawsock_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = sock_no_getname, + .poll = datagram_poll, + .ioctl = sock_no_ioctl, + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .sendmsg = rawsock_sendmsg, + .recvmsg = rawsock_recvmsg, + .mmap = sock_no_mmap, +}; + +static const struct proto_ops rawsock_raw_ops = { + .family = PF_NFC, + .owner = THIS_MODULE, + .release = rawsock_release, + .bind = sock_no_bind, + .connect = sock_no_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = sock_no_getname, + .poll = datagram_poll, + .ioctl = sock_no_ioctl, + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .sendmsg = sock_no_sendmsg, + .recvmsg = rawsock_recvmsg, + .mmap = sock_no_mmap, +}; + +static void rawsock_destruct(struct sock *sk) +{ + pr_debug("sk=%p\n", sk); + + if (sk->sk_state == TCP_ESTABLISHED) { + nfc_deactivate_target(nfc_rawsock(sk)->dev, + nfc_rawsock(sk)->target_idx, + NFC_TARGET_MODE_IDLE); + nfc_put_device(nfc_rawsock(sk)->dev); + } + + skb_queue_purge(&sk->sk_receive_queue); + + if (!sock_flag(sk, SOCK_DEAD)) { + pr_err("Freeing alive NFC raw socket %p\n", sk); + return; + } +} + +static int rawsock_create(struct net *net, struct socket *sock, + const struct nfc_protocol *nfc_proto, int kern) +{ + struct sock *sk; + + pr_debug("sock=%p\n", sock); + + if ((sock->type != SOCK_SEQPACKET) && (sock->type != SOCK_RAW)) + return -ESOCKTNOSUPPORT; + + if (sock->type == SOCK_RAW) { + if (!ns_capable(net->user_ns, CAP_NET_RAW)) + return -EPERM; + sock->ops = &rawsock_raw_ops; + } else { + sock->ops = &rawsock_ops; + } + + sk = sk_alloc(net, PF_NFC, GFP_ATOMIC, nfc_proto->proto, kern); + if (!sk) + return -ENOMEM; + + sock_init_data(sock, sk); + sk->sk_protocol = nfc_proto->id; + sk->sk_destruct = rawsock_destruct; + sock->state = SS_UNCONNECTED; + if (sock->type == SOCK_RAW) + nfc_sock_link(&raw_sk_list, sk); + else { + INIT_WORK(&nfc_rawsock(sk)->tx_work, rawsock_tx_work); + nfc_rawsock(sk)->tx_work_scheduled = false; + } + + return 0; +} + +void nfc_send_to_raw_sock(struct nfc_dev *dev, struct sk_buff *skb, + u8 payload_type, u8 direction) +{ + struct sk_buff *skb_copy = NULL, *nskb; + struct sock *sk; + u8 *data; + + read_lock(&raw_sk_list.lock); + + sk_for_each(sk, &raw_sk_list.head) { + if (!skb_copy) { + skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE, + GFP_ATOMIC, true); + if (!skb_copy) + continue; + + data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE); + + data[0] = dev ? dev->idx : 0xFF; + data[1] = direction & 0x01; + data[1] |= (payload_type << 1); + } + + nskb = skb_clone(skb_copy, GFP_ATOMIC); + if (!nskb) + continue; + + if (sock_queue_rcv_skb(sk, nskb)) + kfree_skb(nskb); + } + + read_unlock(&raw_sk_list.lock); + + kfree_skb(skb_copy); +} +EXPORT_SYMBOL(nfc_send_to_raw_sock); + +static struct proto rawsock_proto = { + .name = "NFC_RAW", + .owner = THIS_MODULE, + .obj_size = sizeof(struct nfc_rawsock), +}; + +static const struct nfc_protocol rawsock_nfc_proto = { + .id = NFC_SOCKPROTO_RAW, + .proto = &rawsock_proto, + .owner = THIS_MODULE, + .create = rawsock_create +}; + +int __init rawsock_init(void) +{ + int rc; + + rc = nfc_proto_register(&rawsock_nfc_proto); + + return rc; +} + +void rawsock_exit(void) +{ + nfc_proto_unregister(&rawsock_nfc_proto); +} |