diff options
author | Thierry Escande <thierry.escande@linux.intel.com> | 2013-09-19 15:55:29 (GMT) |
---|---|---|
committer | Samuel Ortiz <sameo@linux.intel.com> | 2013-09-25 00:02:27 (GMT) |
commit | 7d0911c02fa2a448a28d7844d2a0c439ff8397b1 (patch) | |
tree | c9638f5b6ebab6323c51037a8e871d6cf91d8efd /net/nfc/digital_dep.c | |
parent | 8c0695e4998dd268ff2a05951961247b7e015651 (diff) | |
download | linux-7d0911c02fa2a448a28d7844d2a0c439ff8397b1.tar.xz |
NFC Digital: Add initiator NFC-DEP support
This adds support for NFC-DEP protocol in initiator mode for NFC-A and
NFC-F technologies.
When a target is detected, the process flow is as follow:
For NFC-A technology:
1 - The digital stack receives a SEL_RES as the reply of the SEL_REQ
command.
2 - If b7 of SEL_RES is set, the peer device is configure for NFC-DEP
protocol. NFC core is notified through nfc_targets_found().
Execution continues at step 4.
3 - Otherwise, it's a tag and the NFC core is notified. Detection
ends.
4 - The digital stacks sends an ATR_REQ command containing a randomly
generated NFCID3 and the general bytes obtained from the LLCP layer
of NFC core.
For NFC-F technology:
1 - The digital stack receives a SENSF_RES as the reply of the
SENSF_REQ command.
2 - If B1 and B2 of NFCID2 are 0x01 and 0xFE respectively, the peer
device is configured for NFC-DEP protocol. NFC core is notified
through nfc_targets_found(). Execution continues at step 4.
3 - Otherwise it's a type 3 tag. NFC core is notified. Detection
ends.
4 - The digital stacks sends an ATR_REQ command containing the NFC-F
NFCID2 as NFCID3 and the general bytes obtained from the LLCP layer
of NFC core.
For both technologies:
5 - The digital stacks receives the ATR_RES response containing the
NFCID3 and the general bytes of the peer device.
6 - The digital stack notifies NFC core that the DEP link is up through
nfc_dep_link_up().
7 - The NFC core performs data exchange through tm_transceive().
8 - The digital stack sends a DEP_REQ command containing an I PDU with
the data from NFC core.
9 - The digital stack receives a DEP_RES command
10 - If the DEP_RES response contains a supervisor PDU with timeout
extension request (RTOX) the digital stack sends a DEP_REQ
command containing a supervisor PDU acknowledging the RTOX
request. The execution continues at step 9.
11 - If the DEP_RES response contains an I PDU, the response data is
passed back to NFC core through the response callback. The
execution continues at step 8.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Diffstat (limited to 'net/nfc/digital_dep.c')
-rw-r--r-- | net/nfc/digital_dep.c | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/net/nfc/digital_dep.c b/net/nfc/digital_dep.c new file mode 100644 index 0000000..be984c4 --- /dev/null +++ b/net/nfc/digital_dep.c @@ -0,0 +1,381 @@ +/* + * NFC Digital Protocol stack + * Copyright (c) 2013, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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. + * + */ + +#include "digital.h" + +#define DIGITAL_NFC_DEP_FRAME_DIR_OUT 0xD4 +#define DIGITAL_NFC_DEP_FRAME_DIR_IN 0xD5 + +#define DIGITAL_NFC_DEP_NFCA_SOD_SB 0xF0 + +#define DIGITAL_CMD_ATR_REQ 0x00 +#define DIGITAL_CMD_ATR_RES 0x01 +#define DIGITAL_CMD_PSL_REQ 0x04 +#define DIGITAL_CMD_PSL_RES 0x05 +#define DIGITAL_CMD_DEP_REQ 0x06 +#define DIGITAL_CMD_DEP_RES 0x07 + +#define DIGITAL_ATR_REQ_MIN_SIZE 16 +#define DIGITAL_ATR_REQ_MAX_SIZE 64 + +#define DIGITAL_NFCID3_LEN ((u8)8) +#define DIGITAL_LR_BITS_PAYLOAD_SIZE_254B 0x30 +#define DIGITAL_GB_BIT 0x02 + +#define DIGITAL_NFC_DEP_PFB_TYPE(pfb) ((pfb) & 0xE0) + +#define DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT 0x10 + +#define DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb) \ + ((pfb) & DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT) +#define DIGITAL_NFC_DEP_MI_BIT_SET(pfb) ((pfb) & 0x10) +#define DIGITAL_NFC_DEP_NAD_BIT_SET(pfb) ((pfb) & 0x08) +#define DIGITAL_NFC_DEP_DID_BIT_SET(pfb) ((pfb) & 0x04) +#define DIGITAL_NFC_DEP_PFB_PNI(pfb) ((pfb) & 0x03) + +#define DIGITAL_NFC_DEP_PFB_I_PDU 0x00 +#define DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU 0x40 +#define DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU 0x80 + +struct digital_atr_req { + u8 dir; + u8 cmd; + u8 nfcid3[10]; + u8 did; + u8 bs; + u8 br; + u8 pp; + u8 gb[0]; +} __packed; + +struct digital_atr_res { + u8 dir; + u8 cmd; + u8 nfcid3[10]; + u8 did; + u8 bs; + u8 br; + u8 to; + u8 pp; + u8 gb[0]; +} __packed; + +struct digital_psl_req { + u8 dir; + u8 cmd; + u8 did; + u8 brs; + u8 fsl; +} __packed; + +struct digital_psl_res { + u8 dir; + u8 cmd; + u8 did; +} __packed; + +struct digital_dep_req_res { + u8 dir; + u8 cmd; + u8 pfb; +} __packed; + +static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg, + struct sk_buff *resp); + +static void digital_skb_push_dep_sod(struct nfc_digital_dev *ddev, + struct sk_buff *skb) +{ + skb_push(skb, sizeof(u8)); + + skb->data[0] = skb->len; + + if (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A) + *skb_push(skb, sizeof(u8)) = DIGITAL_NFC_DEP_NFCA_SOD_SB; +} + +static int digital_skb_pull_dep_sod(struct nfc_digital_dev *ddev, + struct sk_buff *skb) +{ + u8 size; + + if (skb->len < 2) + return -EIO; + + if (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A) + skb_pull(skb, sizeof(u8)); + + size = skb->data[0]; + if (size != skb->len) + return -EIO; + + skb_pull(skb, sizeof(u8)); + + return 0; +} + +static void digital_in_recv_atr_res(struct nfc_digital_dev *ddev, void *arg, + struct sk_buff *resp) +{ + struct nfc_target *target = arg; + struct digital_atr_res *atr_res; + u8 gb_len; + int rc; + + if (IS_ERR(resp)) { + rc = PTR_ERR(resp); + resp = NULL; + goto exit; + } + + rc = ddev->skb_check_crc(resp); + if (rc) { + PROTOCOL_ERR("14.4.1.6"); + goto exit; + } + + rc = digital_skb_pull_dep_sod(ddev, resp); + if (rc) { + PROTOCOL_ERR("14.4.1.2"); + goto exit; + } + + if (resp->len < sizeof(struct digital_atr_res)) { + rc = -EIO; + goto exit; + } + + gb_len = resp->len - sizeof(struct digital_atr_res); + + atr_res = (struct digital_atr_res *)resp->data; + + rc = nfc_set_remote_general_bytes(ddev->nfc_dev, atr_res->gb, gb_len); + if (rc) + goto exit; + + rc = nfc_dep_link_is_up(ddev->nfc_dev, target->idx, NFC_COMM_ACTIVE, + NFC_RF_INITIATOR); + + ddev->curr_nfc_dep_pni = 0; + +exit: + dev_kfree_skb(resp); + + if (rc) + ddev->curr_protocol = 0; +} + +int digital_in_send_atr_req(struct nfc_digital_dev *ddev, + struct nfc_target *target, __u8 comm_mode, __u8 *gb, + size_t gb_len) +{ + struct sk_buff *skb; + struct digital_atr_req *atr_req; + uint size; + + size = DIGITAL_ATR_REQ_MIN_SIZE + gb_len; + + if (size > DIGITAL_ATR_REQ_MAX_SIZE) { + PROTOCOL_ERR("14.6.1.1"); + return -EINVAL; + } + + skb = digital_skb_alloc(ddev, size); + if (!skb) + return -ENOMEM; + + skb_put(skb, sizeof(struct digital_atr_req)); + + atr_req = (struct digital_atr_req *)skb->data; + memset(atr_req, 0, sizeof(struct digital_atr_req)); + + atr_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT; + atr_req->cmd = DIGITAL_CMD_ATR_REQ; + if (target->nfcid2_len) + memcpy(atr_req->nfcid3, target->nfcid2, + max(target->nfcid2_len, DIGITAL_NFCID3_LEN)); + else + get_random_bytes(atr_req->nfcid3, DIGITAL_NFCID3_LEN); + + atr_req->did = 0; + atr_req->bs = 0; + atr_req->br = 0; + + atr_req->pp = DIGITAL_LR_BITS_PAYLOAD_SIZE_254B; + + if (gb_len) { + atr_req->pp |= DIGITAL_GB_BIT; + memcpy(skb_put(skb, gb_len), gb, gb_len); + } + + digital_skb_push_dep_sod(ddev, skb); + + ddev->skb_add_crc(skb); + + digital_in_send_cmd(ddev, skb, 500, digital_in_recv_atr_res, target); + + return 0; +} + +static int digital_in_send_rtox(struct nfc_digital_dev *ddev, + struct digital_data_exch *data_exch, u8 rtox) +{ + struct digital_dep_req_res *dep_req; + struct sk_buff *skb; + int rc; + + skb = digital_skb_alloc(ddev, 1); + if (!skb) + return -ENOMEM; + + *skb_put(skb, 1) = rtox; + + skb_push(skb, sizeof(struct digital_dep_req_res)); + + dep_req = (struct digital_dep_req_res *)skb->data; + + dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT; + dep_req->cmd = DIGITAL_CMD_DEP_REQ; + dep_req->pfb = DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU | + DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT; + + digital_skb_push_dep_sod(ddev, skb); + + ddev->skb_add_crc(skb); + + rc = digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res, + data_exch); + + return rc; +} + +static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg, + struct sk_buff *resp) +{ + struct digital_data_exch *data_exch = arg; + struct digital_dep_req_res *dep_res; + u8 pfb; + uint size; + int rc; + + if (IS_ERR(resp)) { + rc = PTR_ERR(resp); + resp = NULL; + goto exit; + } + + rc = ddev->skb_check_crc(resp); + if (rc) { + PROTOCOL_ERR("14.4.1.6"); + goto error; + } + + rc = digital_skb_pull_dep_sod(ddev, resp); + if (rc) { + PROTOCOL_ERR("14.4.1.2"); + goto exit; + } + + dep_res = (struct digital_dep_req_res *)resp->data; + + if (resp->len < sizeof(struct digital_dep_req_res) || + dep_res->dir != DIGITAL_NFC_DEP_FRAME_DIR_IN || + dep_res->cmd != DIGITAL_CMD_DEP_RES) { + rc = -EIO; + goto error; + } + + pfb = dep_res->pfb; + + switch (DIGITAL_NFC_DEP_PFB_TYPE(pfb)) { + case DIGITAL_NFC_DEP_PFB_I_PDU: + if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) { + PROTOCOL_ERR("14.12.3.3"); + rc = -EIO; + goto error; + } + + ddev->curr_nfc_dep_pni = + DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1); + rc = 0; + break; + + case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU: + PR_ERR("Received a ACK/NACK PDU"); + rc = -EIO; + goto error; + + case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU: + if (!DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) { + rc = -EINVAL; + goto error; + } + + rc = digital_in_send_rtox(ddev, data_exch, resp->data[3]); + if (rc) + goto error; + + kfree_skb(resp); + return; + } + + if (DIGITAL_NFC_DEP_MI_BIT_SET(pfb)) { + PR_ERR("MI bit set. Chained PDU not supported."); + rc = -EIO; + goto error; + } + + size = sizeof(struct digital_dep_req_res); + + if (DIGITAL_NFC_DEP_DID_BIT_SET(pfb)) + size++; + + if (size > resp->len) { + rc = -EIO; + goto error; + } + + skb_pull(resp, size); + +exit: + data_exch->cb(data_exch->cb_context, resp, rc); + +error: + kfree(data_exch); + + if (rc) + kfree_skb(resp); +} + +int digital_in_send_dep_req(struct nfc_digital_dev *ddev, + struct nfc_target *target, struct sk_buff *skb, + struct digital_data_exch *data_exch) +{ + struct digital_dep_req_res *dep_req; + + skb_push(skb, sizeof(struct digital_dep_req_res)); + + dep_req = (struct digital_dep_req_res *)skb->data; + dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT; + dep_req->cmd = DIGITAL_CMD_DEP_REQ; + dep_req->pfb = ddev->curr_nfc_dep_pni; + + digital_skb_push_dep_sod(ddev, skb); + + ddev->skb_add_crc(skb); + + return digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res, + data_exch); +} |