/* * 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 #include #include #include #include #include "../nfc.h" #include "llcp.h" static u8 llcp_tlv_length[LLCP_TLV_MAX] = { 0, 1, /* VERSION */ 2, /* MIUX */ 2, /* WKS */ 1, /* LTO */ 1, /* RW */ 0, /* SN */ 1, /* OPT */ 0, /* SDREQ */ 2, /* SDRES */ }; static u8 llcp_tlv8(u8 *tlv, u8 type) { if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]]) return 0; return tlv[2]; } static u8 llcp_tlv16(u8 *tlv, u8 type) { if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]]) return 0; return be16_to_cpu(*((__be16 *)(tlv + 2))); } static u8 llcp_tlv_version(u8 *tlv) { return llcp_tlv8(tlv, LLCP_TLV_VERSION); } static u16 llcp_tlv_miux(u8 *tlv) { return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7f; } static u16 llcp_tlv_wks(u8 *tlv) { return llcp_tlv16(tlv, LLCP_TLV_WKS); } static u16 llcp_tlv_lto(u8 *tlv) { return llcp_tlv8(tlv, LLCP_TLV_LTO); } static u8 llcp_tlv_opt(u8 *tlv) { return llcp_tlv8(tlv, LLCP_TLV_OPT); } static u8 llcp_tlv_rw(u8 *tlv) { return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf; } u8 *nfc_llcp_build_tlv(u8 type, u8 *value, u8 value_length, u8 *tlv_length) { u8 *tlv, length; pr_debug("type %d\n", type); if (type >= LLCP_TLV_MAX) return NULL; length = llcp_tlv_length[type]; if (length == 0 && value_length == 0) return NULL; else length = value_length; *tlv_length = 2 + length; tlv = kzalloc(2 + length, GFP_KERNEL); if (tlv == NULL) return tlv; tlv[0] = type; tlv[1] = length; memcpy(tlv + 2, value, length); return tlv; } int nfc_llcp_parse_tlv(struct nfc_llcp_local *local, u8 *tlv_array, u16 tlv_array_len) { u8 *tlv = tlv_array, type, length, offset = 0; pr_debug("TLV array length %d\n", tlv_array_len); if (local == NULL) return -ENODEV; while (offset < tlv_array_len) { type = tlv[0]; length = tlv[1]; pr_debug("type 0x%x length %d\n", type, length); switch (type) { case LLCP_TLV_VERSION: local->remote_version = llcp_tlv_version(tlv); break; case LLCP_TLV_MIUX: local->remote_miu = llcp_tlv_miux(tlv) + 128; break; case LLCP_TLV_WKS: local->remote_wks = llcp_tlv_wks(tlv); break; case LLCP_TLV_LTO: local->remote_lto = llcp_tlv_lto(tlv) * 10; break; case LLCP_TLV_OPT: local->remote_opt = llcp_tlv_opt(tlv); break; case LLCP_TLV_RW: local->remote_rw = llcp_tlv_rw(tlv); break; case LLCP_TLV_SN: break; default: pr_err("Invalid gt tlv value 0x%x\n", type); break; } offset += length + 2; tlv += length + 2; } pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x rw %d\n", local->remote_version, local->remote_miu, local->remote_lto, local->remote_opt, local->remote_wks, local->remote_rw); return 0; } static struct sk_buff *llcp_add_header(struct sk_buff *pdu, u8 dsap, u8 ssap, u8 ptype) { u8 header[2]; pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap); header[0] = (u8)((dsap << 2) | (ptype >> 2)); header[1] = (u8)((ptype << 6) | ssap); pr_debug("header 0x%x 0x%x\n", header[0], header[1]); memcpy(skb_put(pdu, LLCP_HEADER_SIZE), header, LLCP_HEADER_SIZE); return pdu; } static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv, u8 tlv_length) { /* XXX Add an skb length check */ if (tlv == NULL) return NULL; memcpy(skb_put(pdu, tlv_length), tlv, tlv_length); return pdu; } static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock, u8 cmd, u16 size) { struct sk_buff *skb; int err; if (sock->ssap == 0) return NULL; skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT, size + LLCP_HEADER_SIZE, &err); if (skb == NULL) { pr_err("Could not allocate PDU\n"); return NULL; } skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd); return skb; } int nfc_llcp_disconnect(struct nfc_llcp_sock *sock) { struct sk_buff *skb; struct nfc_dev *dev; struct nfc_llcp_local *local; u16 size = 0; pr_debug("Sending DISC\n"); local = sock->local; if (local == NULL) return -ENODEV; dev = sock->dev; if (dev == NULL) return -ENODEV; size += LLCP_HEADER_SIZE; size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; skb = alloc_skb(size, GFP_ATOMIC); if (skb == NULL) return -ENOMEM; skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); skb = llcp_add_header(skb, sock->ssap, sock->dsap, LLCP_PDU_DISC); skb_queue_tail(&local->tx_queue, skb); return 0; } int nfc_llcp_send_symm(struct nfc_dev *dev) { struct sk_buff *skb; struct nfc_llcp_local *local; u16 size = 0; pr_debug("Sending SYMM\n"); local = nfc_llcp_find_local(dev); if (local == NULL) return -ENODEV; size += LLCP_HEADER_SIZE; size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; skb = alloc_skb(size, GFP_KERNEL); if (skb == NULL) return -ENOMEM; skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM); return nfc_data_exchange(dev, local->target_idx, skb, nfc_llcp_recv, local); } int nfc_llcp_send_connect(struct nfc_llcp_sock *sock) { struct nfc_llcp_local *local; struct sk_buff *skb; u8 *service_name_tlv = NULL, service_name_tlv_length; u8 *miux_tlv = NULL, miux_tlv_length; u8 *rw_tlv = NULL, rw_tlv_length, rw; __be16 miux; int err; u16 size = 0; pr_debug("Sending CONNECT\n"); local = sock->local; if (local == NULL) return -ENODEV; if (sock->service_name != NULL) { service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN, sock->service_name, sock->service_name_len, &service_name_tlv_length); size += service_name_tlv_length; } miux = cpu_to_be16(LLCP_MAX_MIUX); miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0, &miux_tlv_length); size += miux_tlv_length; rw = LLCP_MAX_RW; rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); size += rw_tlv_length; pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len); skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size); if (skb == NULL) { err = -ENOMEM; goto error_tlv; } if (service_name_tlv != NULL) skb = llcp_add_tlv(skb, service_name_tlv, service_name_tlv_length); skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length); skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length); skb_queue_tail(&local->tx_queue, skb); return 0; error_tlv: pr_err("error %d\n", err); kfree(service_name_tlv); kfree(miux_tlv); kfree(rw_tlv); return err; } int nfc_llcp_send_cc(struct nfc_llcp_sock *sock) { struct nfc_llcp_local *local; struct sk_buff *skb; u8 *miux_tlv = NULL, miux_tlv_length; u8 *rw_tlv = NULL, rw_tlv_length, rw; __be16 miux; int err; u16 size = 0; pr_debug("Sending CC\n"); local = sock->local; if (local == NULL) return -ENODEV; miux = cpu_to_be16(LLCP_MAX_MIUX); miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0, &miux_tlv_length); size += miux_tlv_length; rw = LLCP_MAX_RW; rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); size += rw_tlv_length; skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size); if (skb == NULL) { err = -ENOMEM; goto error_tlv; } skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length); skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length); skb_queue_tail(&local->tx_queue, skb); return 0; error_tlv: pr_err("error %d\n", err); kfree(miux_tlv); kfree(rw_tlv); return err; } int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason) { struct sk_buff *skb; struct nfc_dev *dev; u16 size = 1; /* Reason code */ pr_debug("Sending DM reason 0x%x\n", reason); if (local == NULL) return -ENODEV; dev = local->dev; if (dev == NULL) return -ENODEV; size += LLCP_HEADER_SIZE; size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; skb = alloc_skb(size, GFP_KERNEL); if (skb == NULL) return -ENOMEM; skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); skb = llcp_add_header(skb, ssap, dsap, LLCP_PDU_DM); memcpy(skb_put(skb, 1), &reason, 1); skb_queue_head(&local->tx_queue, skb); return 0; } int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock) { struct sk_buff *skb; struct nfc_llcp_local *local; pr_debug("Send DISC\n"); local = sock->local; if (local == NULL) return -ENODEV; skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0); if (skb == NULL) return -ENOMEM; skb_queue_head(&local->tx_queue, skb); return 0; } int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock, struct msghdr *msg, size_t len) { struct sk_buff *pdu; struct sock *sk = &sock->sk; struct nfc_llcp_local *local; size_t frag_len = 0, remaining_len; u8 *msg_data, *msg_ptr; pr_debug("Send I frame len %zd\n", len); local = sock->local; if (local == NULL) return -ENODEV; msg_data = kzalloc(len, GFP_KERNEL); if (msg_data == NULL) return -ENOMEM; if (memcpy_fromiovec(msg_data, msg->msg_iov, len)) { kfree(msg_data); return -EFAULT; } remaining_len = len; msg_ptr = msg_data; while (remaining_len > 0) { frag_len = min_t(size_t, local->remote_miu, remaining_len); pr_debug("Fragment %zd bytes remaining %zd", frag_len, remaining_len); pdu = llcp_allocate_pdu(sock, LLCP_PDU_I, frag_len + LLCP_SEQUENCE_SIZE); if (pdu == NULL) return -ENOMEM; skb_put(pdu, LLCP_SEQUENCE_SIZE); memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len); skb_queue_head(&sock->tx_queue, pdu); lock_sock(sk); nfc_llcp_queue_i_frames(sock); release_sock(sk); remaining_len -= frag_len; msg_ptr += frag_len; } kfree(msg_data); return 0; } int nfc_llcp_send_rr(struct nfc_llcp_sock *sock) { struct sk_buff *skb; struct nfc_llcp_local *local; pr_debug("Send rr nr %d\n", sock->recv_n); local = sock->local; if (local == NULL) return -ENODEV; skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE); if (skb == NULL) return -ENOMEM; skb_put(skb, LLCP_SEQUENCE_SIZE); skb->data[2] = sock->recv_n % 16; skb_queue_head(&local->tx_queue, skb); return 0; }