// 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 #include #include #include #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; 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); } 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 (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, 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_DISC && sk != NULL && sk->sk_state == LLCP_DISCONNECTING) { nfc_llcp_sock_unlink(&local->sockets, sk); sock_orphan(sk); sock_put(sk); } 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; 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) { 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(); }