diff options
Diffstat (limited to 'net/nfc/llcp_core.c')
| -rw-r--r-- | net/nfc/llcp_core.c | 1624 |
1 files changed, 1624 insertions, 0 deletions
diff --git a/net/nfc/llcp_core.c b/net/nfc/llcp_core.c new file mode 100644 index 000000000000..158bdbf668cc --- /dev/null +++ b/net/nfc/llcp_core.c @@ -0,0 +1,1624 @@ +/* + * 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/list.h> +#include <linux/nfc.h> + +#include "nfc.h" +#include "llcp.h" + +static u8 llcp_magic[3] = {0x46, 0x66, 0x6d}; + +static struct list_head llcp_devices; + +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; + + pr_debug("%p\n", &sock->sk); + + 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); +} + +struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local) +{ + 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); + 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); + + list_del(&local->list); + local_cleanup(local); + kfree(local); +} + +int nfc_llcp_local_put(struct nfc_llcp_local *local) +{ + if (local == NULL) + return 0; + + return kref_put(&local->ref, local_release); +} + +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; + break; + } + } + + read_unlock(&local->sockets.lock); + + if (llcp_sock == NULL) + return NULL; + + sock_hold(&llcp_sock->sk); + + 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(unsigned long data) +{ + struct nfc_llcp_local *local = (struct nfc_llcp_local *) data; + + 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(unsigned long data) +{ + struct nfc_llcp_local *local = (struct nfc_llcp_local *) data; + + schedule_work(&local->sdreq_timeout_work); +} + +struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev) +{ + struct nfc_llcp_local *local, *n; + + list_for_each_entry_safe(local, n, &llcp_devices, list) + if (local->dev == dev) + return local; + + pr_debug("No device 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(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, + u8 *sn, size_t sn_len) +{ + 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; + 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 (local->local_wks & BIT(ssap)) { + 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) != 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_tlv, version, version_length; + u8 *lto_tlv, lto_length; + u8 *wks_tlv, wks_length; + u8 *miux_tlv, miux_length; + u8 gb_len = 0; + int ret = 0; + + version = LLCP_VERSION_11; + version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version, + 1, &version_length); + gb_len += version_length; + + lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, <o_length); + gb_len += lto_length; + + pr_debug("Local wks 0x%lx\n", local->local_wks); + wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&local->local_wks, 2, + &wks_length); + gb_len += wks_length; + + miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0, + &miux_length); + 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; + + return local->gb; +} + +int nfc_llcp_set_remote_gb(struct nfc_dev *dev, u8 *gb, u8 gb_len) +{ + struct nfc_llcp_local *local = nfc_llcp_find_local(dev); + + if (local == NULL) { + pr_err("No LLCP device\n"); + return -ENODEV; + } + if (gb_len < 3) + return -EINVAL; + + 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"); + return -EINVAL; + } + + return nfc_llcp_parse_gb_tlv(local, + &local->remote_gb[3], + local->remote_gb_len - 3); +} + +static u8 nfc_llcp_dsap(struct sk_buff *pdu) +{ + return (pdu->data[0] & 0xfc) >> 2; +} + +static u8 nfc_llcp_ptype(struct sk_buff *pdu) +{ + return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6); +} + +static u8 nfc_llcp_ssap(struct sk_buff *pdu) +{ + return pdu->data[1] & 0x3f; +} + +static u8 nfc_llcp_ns(struct sk_buff *pdu) +{ + return pdu->data[2] >> 4; +} + +static u8 nfc_llcp_nr(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(skb, NFC_LLCP_RAW_HEADER_SIZE, + GFP_ATOMIC); + + if (skb_copy == NULL) + continue; + + data = skb_push(skb_copy, NFC_LLCP_RAW_HEADER_SIZE); + + data[0] = local->dev ? local->dev->idx : 0xFF; + data[1] = direction; + } + + 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) { + 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(KERN_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_LLCP_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, + u8 *sn, size_t sn_len) +{ + struct nfc_llcp_sock *llcp_sock; + + llcp_sock = nfc_llcp_sock_from_sn(local, sn, sn_len); + + if (llcp_sock == NULL) + return NULL; + + sock_hold(&llcp_sock->sk); + + return llcp_sock; +} + +static u8 *nfc_llcp_connect_sn(struct sk_buff *skb, size_t *sn_len) +{ + u8 *tlv = &skb->data[2], type, length; + 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, + 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 { + 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); + 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->dev = local->dev; + new_sock->local = nfc_llcp_local_get(local); + new_sock->rw = sock->rw; + new_sock->miux = sock->miux; + new_sock->remote_miu = local->remote_miu; + 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, 0); + + /* 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, + 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, 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, 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, + struct sk_buff *skb) +{ + struct nfc_llcp_sock *llcp_sock; + u8 dsap, ssap, *tlv, type, length, tid, sap; + u16 tlv_len, offset; + 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); + 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; + 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); + +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; + } + + memcpy(skb_put(new_skb, pdu_len), 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(KERN_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_LLCP_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; + + pr_debug("Received an LLCP PDU\n"); + if (err < 0) { + pr_err("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) + return -ENODEV; + + __nfc_llcp_recv(local, skb); + + 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); +} + +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)); + } +} + +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; + + local->dev = ndev; + INIT_LIST_HEAD(&local->list); + kref_init(&local->ref); + mutex_init(&local->sdp_lock); + init_timer(&local->link_timer); + local->link_timer.data = (unsigned long) local; + local->link_timer.function = nfc_llcp_symm_timer; + + 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); + + 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); + init_timer(&local->sdreq_timer); + local->sdreq_timer.data = (unsigned long) local; + local->sdreq_timer.function = nfc_llcp_sdreq_timer; + INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work); + + list_add(&local->list, &llcp_devices); + + return 0; +} + +void nfc_llcp_unregister_device(struct nfc_dev *dev) +{ + struct nfc_llcp_local *local = nfc_llcp_find_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) +{ + INIT_LIST_HEAD(&llcp_devices); + + return nfc_llcp_sock_init(); +} + +void nfc_llcp_exit(void) +{ + nfc_llcp_sock_exit(); +} |
