// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2011 Intel Corporation. All rights reserved.
* Copyright (C) 2014 Marvell International Ltd.
*/
#define pr_fmt(fmt) "llcp: %s: " fmt, __func__
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/nfc.h>
#include "nfc.h"
#include "llcp.h"
static u8 llcp_magic[3] = {0x46, 0x66, 0x6d};
static LIST_HEAD(llcp_devices);
/* Protects llcp_devices list */
static DEFINE_SPINLOCK(llcp_devices_lock);
static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb);
void nfc_llcp_sock_link(struct llcp_sock_list *l, struct sock *sk)
{
write_lock(&l->lock);
sk_add_node(sk, &l->head);
write_unlock(&l->lock);
}
void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *sk)
{
write_lock(&l->lock);
sk_del_node_init(sk);
write_unlock(&l->lock);
}
void nfc_llcp_socket_remote_param_init(struct nfc_llcp_sock *sock)
{
sock->remote_rw = LLCP_DEFAULT_RW;
sock->remote_miu = LLCP_MAX_MIU + 1;
}
static void nfc_llcp_socket_purge(struct nfc_llcp_sock *sock)
{
struct nfc_llcp_local *local = sock->local;
struct sk_buff *s, *tmp;
skb_queue_purge(&sock->tx_queue);
skb_queue_purge(&sock->tx_pending_queue);
if (local == NULL)
return;
/* Search for local pending SKBs that are related to this socket */
skb_queue_walk_safe(&local->tx_queue, s, tmp) {
if (s->sk != &sock->sk)
continue;
skb_unlink(s, &local->tx_queue);
kfree_skb(s);
}
}
static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool device,
int err)
{
struct sock *sk;
struct hlist_node *tmp;
struct nfc_llcp_sock *llcp_sock;
skb_queue_purge(&local->tx_queue);
write_lock(&local->sockets.lock);
sk_for_each_safe(sk, tmp, &local->sockets.head) {
llcp_sock = nfc_llcp_sock(sk);
bh_lock_sock(sk);
nfc_llcp_socket_purge(llcp_sock);
if (sk->sk_state == LLCP_CONNECTED)
nfc_put_device(llcp_sock->dev);
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;
bh_lock_sock(accept_sk);
nfc_llcp_accept_unlink(accept_sk);
if (err)
accept_sk->sk_err = err;
accept_sk->sk_state = LLCP_CLOSED;
accept_sk->sk_state_change(sk);
bh_unlock_sock(accept_sk);
}
}
if (err)
sk->sk_err = err;
sk->sk_state = LLCP_CLOSED;
sk->sk_state_change(sk);
bh_unlock_sock(sk);
sk_del_node_init(sk);
}
write_unlock(&local->sockets.lock);
/* If we still have a device, we keep the RAW sockets alive */
if (device == true)
return;
write_lock(&local->raw_sockets.lock);
sk_for_each_safe(sk, tmp, &local->raw_sockets.head) {
llcp_sock = nfc_llcp_sock(sk);
bh_lock_sock(sk);
nfc_llcp_socket_purge(llcp_sock);
if (err)
sk->sk_err = err;
sk->sk_state = LLCP_CLOSED;
sk->sk_state_change(sk);
bh_unlock_sock(sk);
sk_del_node_init(sk);
}
write_unlock(&local->raw_sockets.lock);
}
static struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
{
/* Since using nfc_llcp_local may result in usage of nfc_dev, whenever
* we hold a reference to local, we also need to hold a reference to
* the device to avoid UAF.
*/
if (!nfc_get_device(local->dev->idx))
return NULL;
kref_get(&local->ref);
return local;
}
static void local_cleanup(struct nfc_llcp_local *local)
{
nfc_llcp_socket_release(local, false, ENXIO);
del_timer_sync(&local->link_timer);
skb_queue_purge(&local->tx_queue);
cancel_work_sync(&local->tx_work);
cancel_work_sync(&local->rx_work);
cancel_work_sync(&local->timeout_work);
kfree_skb(local->rx_pending);
local->rx_pending = NULL;
del_timer_sync(&local->sdreq_timer);
cancel_work_sync(&local->sdreq_timeout_work);
nfc_llcp_free_sdp_tlv_list(&local->pending_sdreqs);
}
static void local_release(struct kref *ref)
{
struct nfc_llcp_local *local;
local = container_of(ref, struct nfc_llcp_local, ref);
local_cleanup(local);
kfree(local);
}
int nfc_llcp_local_put(struct nfc_llcp_local *local)
{
struct nfc_dev *dev;
int ret;
if (local == NULL)
return 0;
dev = local->dev;
ret = kref_put(&local->ref, local_release);
nfc_put_device(dev);
return ret;
}
static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
u8 ssap, u8 dsap)
{
struct sock *sk;
struct nfc_llcp_sock *llcp_sock, *tmp_sock;
pr_debug("ssap dsap %d %d\n", ssap, dsap);
if (ssap == 0 && dsap == 0)
return NULL;
read_lock(&local->sockets.lock);
llcp_sock = NULL;
sk_for_each(sk, &local->sockets.head) {
tmp_sock = nfc_llcp_sock(sk);
if (tmp_sock->ssap == ssap && tmp_sock->dsap == dsap) {
llcp_sock = tmp_sock;
sock_hold(&llcp_sock->sk);
break;
}
}
read_unlock(&local->sockets.lock);
return llcp_sock;
}
static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
{
sock_put(&sock->sk);
}
static void nfc_llcp_timeout_work(struct work_struct *work)
{
struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
timeout_work);
nfc_dep_link_down(local->dev);
}
static void nfc_llcp_symm_timer(struct timer_list *t)
{
struct nfc_llcp_local *local = from_timer(local, t, link_timer);
pr_err("SYMM timeout\n");
schedule_work(&local->timeout_work);
}
static void nfc_llcp_sdreq_timeout_work(struct work_struct *work)
{
unsigned long time;
HLIST_HEAD(nl_sdres_list);
struct hlist_node *n;
struct nfc_llcp_sdp_tlv *sdp;
struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
sdreq_timeout_work);
mutex_lock(&local->sdreq_lock);
time = jiffies - msecs_to_jiffies(3 * local->remote_lto);
hlist_for_each_entry_safe(sdp, n, &local->pending_sdreqs, node) {
if (time_after(sdp->time, time))
continue;
sdp->sap = LLCP_SDP_UNBOUND;
hlist_del(&sdp->node);
hlist_add_head(&sdp->node, &nl_sdres_list);
}
if (!hlist_empty(&local->pending_sdreqs))
mod_timer(&local->sdreq_timer,
jiffies + msecs_to_jiffies(3 * local->remote_lto));
mutex_unlock(&local->sdreq_lock);
if (!hlist_empty(&nl_sdres_list))
nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
}
static void nfc_llcp_sdreq_timer(struct timer_list *t)
{
struct nfc_llcp_local *local = from_timer(local, t, sdreq_timer);
schedule_work(&local->sdreq_timeout_work);
}
struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
{
struct nfc_llcp_local *local;
struct nfc_llcp_local *res = NULL;
spin_lock(&llcp_devices_lock);
list_for_each_entry(local, &llcp_devices, list)
if (local->dev == dev) {
res = nfc_llcp_local_get(local);
break;
}
spin_unlock(&llcp_devices_lock);
return res;
}
static struct nfc_llcp_local *nfc_llcp_remove_local(struct nfc_dev *dev)
{
struct nfc_llcp_local *local, *tmp;
spin_lock(&llcp_devices_lock);
list_for_each_entry_safe(local, tmp, &llcp_devices, list)
if (local->dev == dev) {
list_del(&local->list);
spin_unlock(&llcp_devices_lock);
return local;
}
spin_unlock(&llcp_devices_lock);
pr_warn("Shutting down device not found\n");
return NULL;
}
static char *wks[] = {
NULL,
NULL, /* SDP */
"urn:nfc:sn:ip",
"urn:nfc:sn:obex",
"urn:nfc:sn:snep",
};
static int nfc_llcp_wks_sap(const char *service_name, size_t service_name_len)
{
int sap, num_wks;
pr_debug("%s\n", service_name);
if (service_name == NULL)
return -EINVAL;
num_wks = ARRAY_SIZE(wks);
for (sap = 0; sap < num_wks; sap++) {
if (wks[sap] == NULL)
continue;
if (strncmp(wks[sap], service_name, service_name_len) == 0)
return sap;
}
return -EINVAL;
}
static
struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
const u8 *sn, size_t sn_len,
bool needref)
{
struct sock *sk;
struct nfc_llcp_sock *llcp_sock, *tmp_sock;
pr_debug("sn %zd %p\n", sn_len, sn);
if (sn == NULL || sn_len == 0)
return NULL;
read_lock(&local->sockets.lock);
llcp_sock = NULL;
sk_for_each(sk, &local->sockets.head) {
tmp_sock = nfc_llcp_sock(sk);
pr_debug("llcp sock %p\n", tmp_sock);
if (tmp_sock->sk.sk_type == SOCK_STREAM &&
tmp_sock->sk.sk_state != LLCP_LISTEN)
continue;
if (tmp_sock->sk.sk_type == SOCK_DGRAM &&
tmp_sock->sk.sk_state != LLCP_BOUND)
continue;
if (tmp_sock->service_name == NULL ||
tmp_sock->service_name_len == 0)
continue;
if (tmp_sock->service_name_len != sn_len)
continue;
if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
llcp_sock = tmp_sock;
if (needref)
sock_hold(&llcp_sock->sk);
break;
}
}
read_unlock(&local->sockets.lock);
pr_debug("Found llcp sock %p\n", llcp_sock);
return llcp_sock;
}
u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
struct nfc_llcp_sock *sock)
{
mutex_lock(&local->sdp_lock);
if (sock->service_name != NULL && sock->service_name_len > 0) {
int ssap = nfc_llcp_wks_sap(sock->service_name,
sock->service_name_len);
if (ssap > 0) {
pr_debug("WKS %d\n", ssap);
/* This is a WKS, let's check if it's free */
if (test_bit(ssap, &local->local_wks)) {
mutex_unlock(&local->sdp_lock);
return LLCP_SAP_MAX;
}
set_bit(ssap, &local->local_wks);
mutex_unlock(&local->sdp_lock);
return ssap;
}
/*
* Check if there already is a non WKS socket bound
* to this service name.
*/
if (nfc_llcp_sock_from_sn(local, sock->service_name,
sock->service_name_len,
false) != NULL) {
mutex_unlock(&local->sdp_lock);
return LLCP_SAP_MAX;
}
mutex_unlock(&local->sdp_lock);
return LLCP_SDP_UNBOUND;
} else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
if (!test_bit(sock->ssap, &local->local_wks)) {
set_bit(sock->ssap, &local->local_wks);
mutex_unlock(&local->sdp_lock);
return sock->ssap;
}
}
mutex_unlock(&local->sdp_lock);
return LLCP_SAP_MAX;
}
u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
{
u8 local_ssap;
mutex_lock(&local->sdp_lock);
local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
if (local_ssap == LLCP_LOCAL_NUM_SAP) {
mutex_unlock(&local->sdp_lock);
return LLCP_SAP_MAX;
}
set_bit(local_ssap, &local->local_sap);
mutex_unlock(&local->sdp_lock);
return local_ssap + LLCP_LOCAL_SAP_OFFSET;
}
void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
{
u8 local_ssap;
unsigned long *sdp;
if (ssap < LLCP_WKS_NUM_SAP) {
local_ssap = ssap;
sdp = &local->local_wks;
} else if (ssap < LLCP_LOCAL_NUM_SAP) {
atomic_t *client_cnt;
local_ssap = ssap - LLCP_WKS_NUM_SAP;
sdp = &local->local_sdp;
client_cnt = &local->local_sdp_cnt[local_ssap];
pr_debug("%d clients\n", atomic_read(client_cnt));
mutex_lock(&local->sdp_lock);
if (atomic_dec_and_test(client_cnt)) {
struct nfc_llcp_sock *l_sock;
pr_debug("No more clients for SAP %d\n", ssap);
clear_bit(local_ssap, sdp);
/* Find the listening sock and set it back to UNBOUND */
l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
if (l_sock) {
l_sock->ssap = LLCP_SDP_UNBOUND;
nfc_llcp_sock_put(l_sock);
}
}
mutex_unlock(&local->sdp_lock);
return;
} else if (ssap < LLCP_MAX_SAP) {
local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
sdp = &local->local_sap;
} else {
return;
}
mutex_lock(&local->sdp_lock);
clear_bit(local_ssap, sdp);
mutex_unlock(&local->sdp_lock);
}
static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
{
u8 ssap;
mutex_lock(&local->sdp_lock);
ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
if (ssap == LLCP_SDP_NUM_SAP) {
mutex_unlock(&local->sdp_lock);
return LLCP_SAP_MAX;
}
pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
set_bit(ssap, &local->local_sdp);
mutex_unlock(&local->sdp_lock);
return LLCP_WKS_NUM_SAP + ssap;
}
static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
{
u8 *gb_cur, version, version_length;
u8 lto_length, wks_length, miux_length;
const u8 *version_tlv = NULL, *lto_tlv = NULL,
*wks_tlv = NULL, *miux_tlv = NULL;
__be16 wks = cpu_to_be16(local->local_wks);
u8 gb_len = 0;
int ret = 0;
version = LLCP_VERSION_11;
version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
1, &version_length);
if (!version_tlv) {
ret = -ENOMEM;
goto out;
}
gb_len += version_length;
lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, <o_length);
if (!lto_tlv) {
ret = -ENOMEM;
goto out;
}
gb_len += lto_length;
pr_debug("Local wks 0x%lx\n", local->local_wks);
wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&wks, 2, &wks_length);
if (!wks_tlv) {
ret = -ENOMEM;
goto out;
}
gb_len += wks_length;
miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
&miux_length);
if (!miux_tlv) {
ret = -ENOMEM;
goto out;
}
gb_len += miux_length;
gb_len += ARRAY_SIZE(llcp_magic);
if (gb_len > NFC_MAX_GT_LEN) {
ret = -EINVAL;
goto out;
}
gb_cur = local->gb;
memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
gb_cur += ARRAY_SIZE(llcp_magic);
memcpy(gb_cur, version_tlv, version_length);
gb_cur += version_length;
memcpy(gb_cur, lto_tlv, lto_length);
gb_cur += lto_length;
memcpy(gb_cur, wks_tlv, wks_length);
gb_cur += wks_length;
memcpy(gb_cur, miux_tlv, miux_length);
gb_cur += miux_length;
local->gb_len = gb_len;
out:
kfree(version_tlv);
kfree(lto_tlv);
kfree(wks_tlv);
kfree(miux_tlv);
return ret;
}
u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
{
struct nfc_llcp_local *local;
local = nfc_llcp_find_local(dev);
if (local == NULL) {
*general_bytes_len = 0;
return NULL;
}
nfc_llcp_build_gb(local);
*general_bytes_len = local->gb_len;
nfc_llcp_local_put(local);
return local->gb;
}
int nfc_llcp_set_remote_gb(struct nfc_dev *dev, const u8 *gb, u8 gb_len)
{
struct nfc_llcp_local *local;
int err;
if (gb_len < 3 || gb_len > NFC_MAX_GT_LEN)
return -EINVAL;
local = nfc_llcp_find_local(dev);
if (local == NULL) {
pr_err("No LLCP device\n");
return -ENODEV;
}
memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
memcpy(local->remote_gb, gb, gb_len);
local->remote_gb_len = gb_len;
if (memcmp(local->remote_gb, llcp_magic, 3)) {
pr_err("MAC does not support LLCP\n");
err = -EINVAL;
goto out;
}
err = nfc_llcp_parse_gb_tlv(local,
&local->remote_gb[3],
local->remote_gb_len - 3);
out:
nfc_llcp_local_put(local);
return err;
}
static u8 nfc_llcp_dsap(const struct sk_buff *pdu)
{
return (pdu->data[0] & 0xfc) >> 2;
}
static u8 nfc_llcp_ptype(const struct sk_buff *pdu)
{
return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
}
static u8 nfc_llcp_ssap(const struct sk_buff *pdu)
{
return pdu->data[1] & 0x3f;
}
static u8 nfc_llcp_ns(const struct sk_buff *pdu)
{
return pdu->data[2] >> 4;
}
static u8 nfc_llcp_nr(const struct sk_buff *pdu)
{
return pdu->data[2] & 0xf;
}
static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
{
pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);
sock->send_n = (sock->send_n + 1) % 16;
sock->recv_ack_n = (sock->recv_n - 1) % 16;
}
void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
struct sk_buff *skb, u8 direction)
{
struct sk_buff *skb_copy = NULL, *nskb;
struct sock *sk;
u8 *data;
read_lock(&local->raw_sockets.lock);
sk_for_each(sk, &local->raw_sockets.head) {
if (sk->sk_state != LLCP_BOUND)
continue;
if (skb_copy == NULL) {
skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
GFP_ATOMIC, true);
if (skb_copy == NULL)
continue;
data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);
data[0] = local->dev ? local->dev->idx : 0xFF;
data[1] = direction & 0x01;
data[1] |= (RAW_PAYLOAD_LLCP << 1);
}
nskb = skb_clone(skb_copy, GFP_ATOMIC);
if (!nskb)
continue;
if (sock_queue_rcv_skb(sk, nskb))
kfree_skb(nskb);
}
read_unlock(&local->raw_sockets.lock);
kfree_skb(skb_copy);
}
static void nfc_llcp_tx_work(struct work_struct *work)
{
struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
tx_work);
struct sk_buff *skb;
struct sock *sk;
struct nfc_llcp_sock *llcp_sock;
skb = skb_dequeue(&local->tx_queue);
if (skb != NULL) {
sk = skb->sk;
llcp_sock = nfc_llcp_sock(sk);
if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
kfree_skb(skb);
nfc_llcp_send_symm(local->dev);
} else if (llcp_sock && !llcp_sock->remote_ready) {
skb_queue_head(&local->tx_queue, skb);
nfc_llcp_send_symm(local->dev);
} else {
struct sk_buff *copy_skb = NULL;
u8 ptype = nfc_llcp_ptype(skb);
int ret;
pr_debug("Sending pending skb\n");
print_hex_dump_debug("LLCP Tx: ", DUMP_PREFIX_OFFSET,
16, 1, skb->data, skb->len, true);
if (ptype == LLCP_PDU_I)
copy_skb = skb_copy(skb, GFP_ATOMIC);
__net_timestamp(skb);
nfc_llcp_send_to_raw_sock(local, skb,
NFC_DIRECTION_TX);
ret = nfc_data_exchange(local->dev, local->target_idx,
skb, nfc_llcp_recv, local);
if (ret) {
kfree_skb(copy_skb);
goto out;
}
if (ptype == LLCP_PDU_I && copy_skb)
skb_queue_tail(&llcp_sock->tx_pending_queue,
copy_skb);
}
} else {
nfc_llcp_send_symm(local->dev);
}
out:
mod_timer(&local->link_timer,
jiffies + msecs_to_jiffies(2 * local->remote_lto));
}
static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
u8 ssap)
{
struct sock *sk;
struct nfc_llcp_sock *llcp_sock;
read_lock(&local->connecting_sockets.lock);
sk_for_each(sk, &local->connecting_sockets.head) {
llcp_sock = nfc_llcp_sock(sk);
if (llcp_sock->ssap == ssap) {
sock_hold(&llcp_sock->sk);
goto out;
}
}
llcp_sock = NULL;
out:
read_unlock(&local->connecting_sockets.lock);
return llcp_sock;
}
static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
const u8 *sn, size_t sn_len)
{
return nfc_llcp_sock_from_sn(local, sn, sn_len, true);
}
static const u8 *nfc_llcp_connect_sn(const struct sk_buff *skb, size_t *sn_len)
{
u8 type, length;
const u8 *tlv = &skb->data[2];
size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
while (offset < tlv_array_len) {
type = tlv[0];
length = tlv[1];
pr_debug("type 0x%x length %d\n", type, length);
if (type == LLCP_TLV_SN) {
*sn_len = length;
return &tlv[2];
}
offset += length + 2;
tlv += length + 2;
}
return NULL;
}
static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
struct sk_buff *skb)
{
struct nfc_llcp_sock *llcp_sock;
struct nfc_llcp_ui_cb *ui_cb;
u8 dsap, ssap;
dsap = nfc_llcp_dsap(skb);
ssap = nfc_llcp_ssap(skb);
ui_cb = nfc_llcp_ui_skb_cb(skb);
ui_cb->dsap = dsap;
ui_cb->ssap = ssap;
pr_debug("%d %d\n", dsap, ssap);
/* We're looking for a bound socket, not a client one */
llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM)
return;
/* There is no sequence with UI frames */
skb_pull(skb, LLCP_HEADER_SIZE);
if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
/*
* UI frames will be freed from the socket layer, so we
* need to keep them alive until someone receives them.
*/
skb_get(skb);
} else {
pr_err("Receive queue is full\n");
}
nfc_llcp_sock_put(llcp_sock);
}
static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
const struct sk_buff *skb)
{
struct sock *new_sk, *parent;
struct nfc_llcp_sock *sock, *new_sock;
u8 dsap, ssap, reason;
dsap = nfc_llcp_dsap(skb);
ssap = nfc_llcp_ssap(skb);
pr_debug("%d %d\n", dsap, ssap);
if (dsap != LLCP_SAP_SDP) {
sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
reason = LLCP_DM_NOBOUND;
goto fail;
}
} else {
const u8 *sn;
size_t sn_len;
sn = nfc_llcp_connect_sn(skb, &sn_len);
if (sn == NULL) {
reason = LLCP_DM_NOBOUND;
goto fail;
}
pr_debug("Service name length %zu\n", sn_len);
sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
if (sock == NULL) {
reason = LLCP_DM_NOBOUND;
goto fail;
}
}
lock_sock(&sock->sk);
parent = &sock->sk;
if (sk_acceptq_is_full(parent)) {
reason = LLCP_DM_REJ;
release_sock(&sock->sk);
sock_put(&sock->sk);
goto fail;
}
if (sock->ssap == LLCP_SDP_UNBOUND) {
u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
pr_debug("First client, reserving %d\n", ssap);
if (ssap == LLCP_SAP_MAX) {
reason = LLCP_DM_REJ;
release_sock(&sock->sk);
sock_put(&sock->sk);
goto fail;
}
sock->ssap = ssap;
}
new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC, 0);
if (new_sk == NULL) {
reason = LLCP_DM_REJ;
release_sock(&sock->sk);
sock_put(&sock->sk);
goto fail;
}
new_sock = nfc_llcp_sock(new_sk);
new_sock->local = nfc_llcp_local_get(local);
if (!new_sock->local) {
reason = LLCP_DM_REJ;
sock_put(&new_sock->sk);
release_sock(&sock->sk);
sock_put(&sock->sk);
goto fail;
}
new_sock->dev = local->dev;
new_sock->rw = sock->rw;
new_sock->miux = sock->miux;
new_sock->nfc_protocol = sock->nfc_protocol;
new_sock->dsap = ssap;
new_sock->target_idx = local->target_idx;
new_sock->parent = parent;
new_sock->ssap = sock->ssap;
if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
atomic_t *client_count;
pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
client_count =
&local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
atomic_inc(client_count);
new_sock->reserved_ssap = sock->ssap;
}
nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
skb->len - LLCP_HEADER_SIZE);
pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
nfc_llcp_sock_link(&local->sockets, new_sk);
nfc_llcp_accept_enqueue(&sock->sk, new_sk);
nfc_get_device(local->dev->idx);
new_sk->sk_state = LLCP_CONNECTED;
/* Wake the listening processes */
parent->sk_data_ready(parent);
/* Send CC */
nfc_llcp_send_cc(new_sock);
release_sock(&sock->sk);
sock_put(&sock->sk);
return;
fail:
/* Send DM */
nfc_llcp_send_dm(local, dsap, ssap, reason);
}
int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)
{
int nr_frames = 0;
struct nfc_llcp_local *local = sock->local;
pr_debug("Remote ready %d tx queue len %d remote rw %d",
sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),
sock->remote_rw);
/* Try to queue some I frames for transmission */
while (sock->remote_ready &&
skb_queue_len(&sock->tx_pending_queue) < sock->remote_rw) {
struct sk_buff *pdu;
pdu = skb_dequeue(&sock->tx_queue);
if (pdu == NULL)
break;
/* Update N(S)/N(R) */
nfc_llcp_set_nrns(sock, pdu);
skb_queue_tail(&local->tx_queue, pdu);
nr_frames++;
}
return nr_frames;
}
static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
struct sk_buff *skb)
{
struct nfc_llcp_sock *llcp_sock;
struct sock *sk;
u8 dsap, ssap, ptype, ns, nr;
ptype = nfc_llcp_ptype(skb);
dsap = nfc_llcp_dsap(skb);
ssap = nfc_llcp_ssap(skb);
ns = nfc_llcp_ns(skb);
nr = nfc_llcp_nr(skb);
pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
if (llcp_sock == NULL) {
nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
return;
}
sk = &llcp_sock->sk;
lock_sock(sk);
if (sk->sk_state == LLCP_CLOSED) {
release_sock(sk);
nfc_llcp_sock_put(llcp_sock);
}
/* Pass the payload upstream */
if (ptype == LLCP_PDU_I) {
pr_debug("I frame, queueing on %p\n", &llcp_sock->sk);
if (ns == llcp_sock->recv_n)
llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
else
pr_err("Received out of sequence I PDU\n");
skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
/*
* I frames will be freed from the socket layer, so we
* need to keep them alive until someone receives them.
*/
skb_get(skb);
} else {
pr_err("Receive queue is full\n");
}
}
/* Remove skbs from the pending queue */
if (llcp_sock->send_ack_n != nr) {
struct sk_buff *s, *tmp;
u8 n;
llcp_sock->send_ack_n = nr;
/* Remove and free all skbs until ns == nr */
skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
n = nfc_llcp_ns(s);
skb_unlink(s, &llcp_sock->tx_pending_queue);
kfree_skb(s);
if (n == nr)
break;
}
/* Re-queue the remaining skbs for transmission */
skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
s, tmp) {
skb_unlink(s, &llcp_sock->tx_pending_queue);
skb_queue_head(&local->tx_queue, s);
}
}
if (ptype == LLCP_PDU_RR)
llcp_sock->remote_ready = true;
else if (ptype == LLCP_PDU_RNR)
llcp_sock->remote_ready = false;
if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)
nfc_llcp_send_rr(llcp_sock);
release_sock(sk);
nfc_llcp_sock_put(llcp_sock);
}
static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
const struct sk_buff *skb)
{
struct nfc_llcp_sock *llcp_sock;
struct sock *sk;
u8 dsap, ssap;
dsap = nfc_llcp_dsap(skb);
ssap = nfc_llcp_ssap(skb);
if ((dsap == 0) && (ssap == 0)) {
pr_debug("Connection termination");
nfc_dep_link_down(local->dev);
return;
}
llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
if (llcp_sock == NULL) {
nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
return;
}
sk = &llcp_sock->sk;
lock_sock(sk);
nfc_llcp_socket_purge(llcp_sock);
if (sk->sk_state == LLCP_CLOSED) {
release_sock(sk);
nfc_llcp_sock_put(llcp_sock);
}
if (sk->sk_state == LLCP_CONNECTED) {
nfc_put_device(local->dev);
sk->sk_state = LLCP_CLOSED;
sk->sk_state_change(sk);
}
nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
release_sock(sk);
nfc_llcp_sock_put(llcp_sock);
}
static void nfc_llcp_recv_cc(struct nfc_llcp_local *local,
const struct sk_buff *skb)
{
struct nfc_llcp_sock *llcp_sock;
struct sock *sk;
u8 dsap, ssap;
dsap = nfc_llcp_dsap(skb);
ssap = nfc_llcp_ssap(skb);
llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
if (llcp_sock == NULL) {
pr_err("Invalid CC\n");
nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
return;
}
sk = &llcp_sock->sk;
/* Unlink from connecting and link to the client array */
nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
nfc_llcp_sock_link(&local->sockets, sk);
llcp_sock->dsap = ssap;
nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
skb->len - LLCP_HEADER_SIZE);
sk->sk_state = LLCP_CONNECTED;
sk->sk_state_change(sk);
nfc_llcp_sock_put(llcp_sock);
}
static void nfc_llcp_recv_dm(struct nfc_llcp_local *local,
const struct sk_buff *skb)
{
struct nfc_llcp_sock *llcp_sock;
struct sock *sk;
u8 dsap, ssap, reason;
dsap = nfc_llcp_dsap(skb);
ssap = nfc_llcp_ssap(skb);
reason = skb->data[2];
pr_debug("%d %d reason %d\n", ssap, dsap, reason);
switch (reason) {
case LLCP_DM_NOBOUND:
case LLCP_DM_REJ:
llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
break;
default:
llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
break;
}
if (llcp_sock == NULL) {
pr_debug("Already closed\n");
return;
}
sk = &llcp_sock->sk;
sk->sk_err = ENXIO;
sk->sk_state = LLCP_CLOSED;
sk->sk_state_change(sk);
nfc_llcp_sock_put(llcp_sock);
}
static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
const struct sk_buff *skb)
{
struct nfc_llcp_sock *llcp_sock;
u8 dsap, ssap, type, length, tid, sap;
const u8 *tlv;
u16 tlv_len, offset;
const char *service_name;
size_t service_name_len;
struct nfc_llcp_sdp_tlv *sdp;
HLIST_HEAD(llc_sdres_list);
size_t sdres_tlvs_len;
HLIST_HEAD(nl_sdres_list);
dsap = nfc_llcp_dsap(skb);
ssap = nfc_llcp_ssap(skb);
pr_debug("%d %d\n", dsap, ssap);
if (dsap != LLCP_SAP_SDP || ssap != LLCP_SAP_SDP) {
pr_err("Wrong SNL SAP\n");
return;
}
tlv = &skb->data[LLCP_HEADER_SIZE];
tlv_len = skb->len - LLCP_HEADER_SIZE;
offset = 0;
sdres_tlvs_len = 0;
while (offset < tlv_len) {
type = tlv[0];
length = tlv[1];
switch (type) {
case LLCP_TLV_SDREQ:
tid = tlv[2];
service_name = (char *) &tlv[3];
service_name_len = length - 1;
pr_debug("Looking for %.16s\n", service_name);
if (service_name_len == strlen("urn:nfc:sn:sdp") &&
!strncmp(service_name, "urn:nfc:sn:sdp",
service_name_len)) {
sap = 1;
goto add_snl;
}
llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
service_name_len,
true);
if (!llcp_sock) {
sap = 0;
goto add_snl;
}
/*
* We found a socket but its ssap has not been reserved
* yet. We need to assign it for good and send a reply.
* The ssap will be freed when the socket is closed.
*/
if (llcp_sock->ssap == LLCP_SDP_UNBOUND) {
atomic_t *client_count;
sap = nfc_llcp_reserve_sdp_ssap(local);
pr_debug("Reserving %d\n", sap);
if (sap == LLCP_SAP_MAX) {
sap = 0;
nfc_llcp_sock_put(llcp_sock);
goto add_snl;
}
client_count =
&local->local_sdp_cnt[sap -
LLCP_WKS_NUM_SAP];
atomic_inc(client_count);
llcp_sock->ssap = sap;
llcp_sock->reserved_ssap = sap;
} else {
sap = llcp_sock->ssap;
}
pr_debug("%p %d\n", llcp_sock, sap);
nfc_llcp_sock_put(llcp_sock);
add_snl:
sdp = nfc_llcp_build_sdres_tlv(tid, sap);
if (sdp == NULL)
goto exit;
sdres_tlvs_len += sdp->tlv_len;
hlist_add_head(&sdp->node, &llc_sdres_list);
break;
case LLCP_TLV_SDRES:
mutex_lock(&local->sdreq_lock);
pr_debug("LLCP_TLV_SDRES: searching tid %d\n", tlv[2]);
hlist_for_each_entry(sdp, &local->pending_sdreqs, node) {
if (sdp->tid != tlv[2])
continue;
sdp->sap = tlv[3];
pr_debug("Found: uri=%s, sap=%d\n",
sdp->uri, sdp->sap);
hlist_del(&sdp->node);
hlist_add_head(&sdp->node, &nl_sdres_list);
break;
}
mutex_unlock(&local->sdreq_lock);
break;
default:
pr_err("Invalid SNL tlv value 0x%x\n", type);
break;
}
offset += length + 2;
tlv += length + 2;
}
exit:
if (!hlist_empty(&nl_sdres_list))
nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
if (!hlist_empty(&llc_sdres_list))
nfc_llcp_send_snl_sdres(local, &llc_sdres_list, sdres_tlvs_len);
}
static void nfc_llcp_recv_agf(struct nfc_llcp_local *local, struct sk_buff *skb)
{
u8 ptype;
u16 pdu_len;
struct sk_buff *new_skb;
if (skb->len <= LLCP_HEADER_SIZE) {
pr_err("Malformed AGF PDU\n");
return;
}
skb_pull(skb, LLCP_HEADER_SIZE);
while (skb->len > LLCP_AGF_PDU_HEADER_SIZE) {
pdu_len = skb->data[0] << 8 | skb->data[1];
skb_pull(skb, LLCP_AGF_PDU_HEADER_SIZE);
if (pdu_len < LLCP_HEADER_SIZE || pdu_len > skb->len) {
pr_err("Malformed AGF PDU\n");
return;
}
ptype = nfc_llcp_ptype(skb);
if (ptype == LLCP_PDU_SYMM || ptype == LLCP_PDU_AGF)
goto next;
new_skb = nfc_alloc_recv_skb(pdu_len, GFP_KERNEL);
if (new_skb == NULL) {
pr_err("Could not allocate PDU\n");
return;
}
skb_put_data(new_skb, skb->data, pdu_len);
nfc_llcp_rx_skb(local, new_skb);
kfree_skb(new_skb);
next:
skb_pull(skb, pdu_len);
}
}
static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb)
{
u8 dsap, ssap, ptype;
ptype = nfc_llcp_ptype(skb);
dsap = nfc_llcp_dsap(skb);
ssap = nfc_llcp_ssap(skb);
pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
if (ptype != LLCP_PDU_SYMM)
print_hex_dump_debug("LLCP Rx: ", DUMP_PREFIX_OFFSET, 16, 1,
skb->data, skb->len, true);
switch (ptype) {
case LLCP_PDU_SYMM:
pr_debug("SYMM\n");
break;
case LLCP_PDU_UI:
pr_debug("UI\n");
nfc_llcp_recv_ui(local, skb);
break;
case LLCP_PDU_CONNECT:
pr_debug("CONNECT\n");
nfc_llcp_recv_connect(local, skb);
break;
case LLCP_PDU_DISC:
pr_debug("DISC\n");
nfc_llcp_recv_disc(local, skb);
break;
case LLCP_PDU_CC:
pr_debug("CC\n");
nfc_llcp_recv_cc(local, skb);
break;
case LLCP_PDU_DM:
pr_debug("DM\n");
nfc_llcp_recv_dm(local, skb);
break;
case LLCP_PDU_SNL:
pr_debug("SNL\n");
nfc_llcp_recv_snl(local, skb);
break;
case LLCP_PDU_I:
case LLCP_PDU_RR:
case LLCP_PDU_RNR:
pr_debug("I frame\n");
nfc_llcp_recv_hdlc(local, skb);
break;
case LLCP_PDU_AGF:
pr_debug("AGF frame\n");
nfc_llcp_recv_agf(local, skb);
break;
}
}
static void nfc_llcp_rx_work(struct work_struct *work)
{
struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
rx_work);
struct sk_buff *skb;
skb = local->rx_pending;
if (skb == NULL) {
pr_debug("No pending SKB\n");
return;
}
__net_timestamp(skb);
nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_RX);
nfc_llcp_rx_skb(local, skb);
schedule_work(&local->tx_work);
kfree_skb(local->rx_pending);
local->rx_pending = NULL;
}
static void __nfc_llcp_recv(struct nfc_llcp_local *local, struct sk_buff *skb)
{
local->rx_pending = skb;
del_timer(&local->link_timer);
schedule_work(&local->rx_work);
}
void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
{
struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
if (err < 0) {
pr_err("LLCP PDU receive err %d\n", err);
return;
}
__nfc_llcp_recv(local, skb);
}
int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
{
struct nfc_llcp_local *local;
local = nfc_llcp_find_local(dev);
if (local == NULL) {
kfree_skb(skb);
return -ENODEV;
}
__nfc_llcp_recv(local, skb);
nfc_llcp_local_put(local);
return 0;
}
void nfc_llcp_mac_is_down(struct nfc_dev *dev)
{
struct nfc_llcp_local *local;
local = nfc_llcp_find_local(dev);
if (local == NULL)
return;
local->remote_miu = LLCP_DEFAULT_MIU;
local->remote_lto = LLCP_DEFAULT_LTO;
/* Close and purge all existing sockets */
nfc_llcp_socket_release(local, true, 0);
nfc_llcp_local_put(local);
}
void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
u8 comm_mode, u8 rf_mode)
{
struct nfc_llcp_local *local;
pr_debug("rf mode %d\n", rf_mode);
local = nfc_llcp_find_local(dev);
if (local == NULL)
return;
local->target_idx = target_idx;
local->comm_mode = comm_mode;
local->rf_mode = rf_mode;
if (rf_mode == NFC_RF_INITIATOR) {
pr_debug("Queueing Tx work\n");
schedule_work(&local->tx_work);
} else {
mod_timer(&local->link_timer,
jiffies + msecs_to_jiffies(local->remote_lto));
}
nfc_llcp_local_put(local);
}
int nfc_llcp_register_device(struct nfc_dev *ndev)
{
struct nfc_llcp_local *local;
local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
if (local == NULL)
return -ENOMEM;
/* As we are going to initialize local's refcount, we need to get the
* nfc_dev to avoid UAF, otherwise there is no point in continuing.
* See nfc_llcp_local_get().
*/
local->dev = nfc_get_device(ndev->idx);
if (!local->dev) {
kfree(local);
return -ENODEV;
}
INIT_LIST_HEAD(&local->list);
kref_init(&local->ref);
mutex_init(&local->sdp_lock);
timer_setup(&local->link_timer, nfc_llcp_symm_timer, 0);
skb_queue_head_init(&local->tx_queue);
INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
local->rx_pending = NULL;
INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
rwlock_init(&local->sockets.lock);
rwlock_init(&local->connecting_sockets.lock);
rwlock_init(&local->raw_sockets.lock);
local->lto = 150; /* 1500 ms */
local->rw = LLCP_MAX_RW;
local->miux = cpu_to_be16(LLCP_MAX_MIUX);
local->local_wks = 0x1; /* LLC Link Management */
nfc_llcp_build_gb(local);
local->remote_miu = LLCP_DEFAULT_MIU;
local->remote_lto = LLCP_DEFAULT_LTO;
mutex_init(&local->sdreq_lock);
INIT_HLIST_HEAD(&local->pending_sdreqs);
timer_setup(&local->sdreq_timer, nfc_llcp_sdreq_timer, 0);
INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work);
spin_lock(&llcp_devices_lock);
list_add(&local->list, &llcp_devices);
spin_unlock(&llcp_devices_lock);
return 0;
}
void nfc_llcp_unregister_device(struct nfc_dev *dev)
{
struct nfc_llcp_local *local = nfc_llcp_remove_local(dev);
if (local == NULL) {
pr_debug("No such device\n");
return;
}
local_cleanup(local);
nfc_llcp_local_put(local);
}
int __init nfc_llcp_init(void)
{
return nfc_llcp_sock_init();
}
void nfc_llcp_exit(void)
{
nfc_llcp_sock_exit();
}
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