// SPDX-License-Identifier: GPL-2.0-only
/*
 *  The NFC Controller Interface is the communication protocol between an
 *  NFC Controller (NFCC) and a Device Host (DH).
 *  This is the HCI over NCI implementation, as specified in the 10.2
 *  section of the NCI 1.1 specification.
 *
 *  Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
 */

#include <linux/skbuff.h>

#include "../nfc.h"
#include <net/nfc/nci.h>
#include <net/nfc/nci_core.h>
#include <linux/nfc.h>
#include <linux/kcov.h>

struct nci_data {
        u8 conn_id;
        u8 pipe;
        u8 cmd;
        const u8 *data;
        u32 data_len;
} __packed;

struct nci_hci_create_pipe_params {
        u8 src_gate;
        u8 dest_host;
        u8 dest_gate;
} __packed;

struct nci_hci_create_pipe_resp {
        u8 src_host;
        u8 src_gate;
        u8 dest_host;
        u8 dest_gate;
        u8 pipe;
} __packed;

struct nci_hci_delete_pipe_noti {
        u8 pipe;
} __packed;

struct nci_hci_all_pipe_cleared_noti {
        u8 host;
} __packed;

struct nci_hcp_message {
        u8 header;      /* type -cmd,evt,rsp- + instruction */
        u8 data[];
} __packed;

struct nci_hcp_packet {
        u8 header;      /* cbit+pipe */
        struct nci_hcp_message message;
} __packed;

#define NCI_HCI_ANY_SET_PARAMETER  0x01
#define NCI_HCI_ANY_GET_PARAMETER  0x02
#define NCI_HCI_ANY_CLOSE_PIPE     0x04
#define NCI_HCI_ADM_CLEAR_ALL_PIPE 0x14

#define NCI_HFP_NO_CHAINING        0x80

#define NCI_NFCEE_ID_HCI                0x80

#define NCI_EVT_HOT_PLUG           0x03

#define NCI_HCI_ADMIN_PARAM_SESSION_IDENTITY       0x01
#define NCI_HCI_ADM_CREATE_PIPE                 0x10
#define NCI_HCI_ADM_DELETE_PIPE                 0x11

/* HCP headers */
#define NCI_HCI_HCP_PACKET_HEADER_LEN      1
#define NCI_HCI_HCP_MESSAGE_HEADER_LEN     1
#define NCI_HCI_HCP_HEADER_LEN             2

/* HCP types */
#define NCI_HCI_HCP_COMMAND        0x00
#define NCI_HCI_HCP_EVENT          0x01
#define NCI_HCI_HCP_RESPONSE       0x02

#define NCI_HCI_ADM_NOTIFY_PIPE_CREATED     0x12
#define NCI_HCI_ADM_NOTIFY_PIPE_DELETED     0x13
#define NCI_HCI_ADM_NOTIFY_ALL_PIPE_CLEARED 0x15

#define NCI_HCI_FRAGMENT           0x7f
#define NCI_HCP_HEADER(type, instr) ((((type) & 0x03) << 6) |\
                                      ((instr) & 0x3f))

#define NCI_HCP_MSG_GET_TYPE(header) ((header & 0xc0) >> 6)
#define NCI_HCP_MSG_GET_CMD(header)  (header & 0x3f)
#define NCI_HCP_MSG_GET_PIPE(header) (header & 0x7f)

static int nci_hci_result_to_errno(u8 result)
{
        switch (result) {
        case NCI_HCI_ANY_OK:
                return 0;
        case NCI_HCI_ANY_E_REG_PAR_UNKNOWN:
                return -EOPNOTSUPP;
        case NCI_HCI_ANY_E_TIMEOUT:
                return -ETIME;
        default:
                return -1;
        }
}

/* HCI core */
static void nci_hci_reset_pipes(struct nci_hci_dev *hdev)
{
        int i;

        for (i = 0; i < NCI_HCI_MAX_PIPES; i++) {
                hdev->pipes[i].gate = NCI_HCI_INVALID_GATE;
                hdev->pipes[i].host = NCI_HCI_INVALID_HOST;
        }
        memset(hdev->gate2pipe, NCI_HCI_INVALID_PIPE, sizeof(hdev->gate2pipe));
}

static void nci_hci_reset_pipes_per_host(struct nci_dev *ndev, u8 host)
{
        int i;

        for (i = 0; i < NCI_HCI_MAX_PIPES; i++) {
                if (ndev->hci_dev->pipes[i].host == host) {
                        ndev->hci_dev->pipes[i].gate = NCI_HCI_INVALID_GATE;
                        ndev->hci_dev->pipes[i].host = NCI_HCI_INVALID_HOST;
                }
        }
}

/* Fragment HCI data over NCI packet.
 * NFC Forum NCI 10.2.2 Data Exchange:
 * The payload of the Data Packets sent on the Logical Connection SHALL be
 * valid HCP packets, as defined within [ETSI_102622]. Each Data Packet SHALL
 * contain a single HCP packet. NCI Segmentation and Reassembly SHALL NOT be
 * applied to Data Messages in either direction. The HCI fragmentation mechanism
 * is used if required.
 */
static int nci_hci_send_data(struct nci_dev *ndev, u8 pipe,
                             const u8 data_type, const u8 *data,
                             size_t data_len)
{
        const struct nci_conn_info *conn_info;
        struct sk_buff *skb;
        int len, i, r;
        u8 cb = pipe;

        conn_info = ndev->hci_dev->conn_info;
        if (!conn_info)
                return -EPROTO;

        i = 0;
        skb = nci_skb_alloc(ndev, conn_info->max_pkt_payload_len +
                            NCI_DATA_HDR_SIZE, GFP_ATOMIC);
        if (!skb)
                return -ENOMEM;

        skb_reserve(skb, NCI_DATA_HDR_SIZE + 2);
        *(u8 *)skb_push(skb, 1) = data_type;

        do {
                /* If last packet add NCI_HFP_NO_CHAINING */
                if (i + conn_info->max_pkt_payload_len -
                    (skb->len + 1) >= data_len) {
                        cb |= NCI_HFP_NO_CHAINING;
                        len = data_len - i;
                } else {
                        len = conn_info->max_pkt_payload_len - skb->len - 1;
                }

                *(u8 *)skb_push(skb, 1) = cb;

                if (len > 0)
                        skb_put_data(skb, data + i, len);

                r = nci_send_data(ndev, conn_info->conn_id, skb);
                if (r < 0)
                        return r;

                i += len;

                if (i < data_len) {
                        skb = nci_skb_alloc(ndev,
                                            conn_info->max_pkt_payload_len +
                                            NCI_DATA_HDR_SIZE, GFP_ATOMIC);
                        if (!skb)
                                return -ENOMEM;

                        skb_reserve(skb, NCI_DATA_HDR_SIZE + 1);
                }
        } while (i < data_len);

        return i;
}

static void nci_hci_send_data_req(struct nci_dev *ndev, const void *opt)
{
        const struct nci_data *data = opt;

        nci_hci_send_data(ndev, data->pipe, data->cmd,
                          data->data, data->data_len);
}

int nci_hci_send_event(struct nci_dev *ndev, u8 gate, u8 event,
                       const u8 *param, size_t param_len)
{
        u8 pipe = ndev->hci_dev->gate2pipe[gate];

        if (pipe == NCI_HCI_INVALID_PIPE)
                return -EADDRNOTAVAIL;

        return nci_hci_send_data(ndev, pipe,
                        NCI_HCP_HEADER(NCI_HCI_HCP_EVENT, event),
                        param, param_len);
}
EXPORT_SYMBOL(nci_hci_send_event);

int nci_hci_send_cmd(struct nci_dev *ndev, u8 gate, u8 cmd,
                     const u8 *param, size_t param_len,
                     struct sk_buff **skb)
{
        const struct nci_hcp_message *message;
        const struct nci_conn_info *conn_info;
        struct nci_data data;
        int r;
        u8 pipe = ndev->hci_dev->gate2pipe[gate];

        if (pipe == NCI_HCI_INVALID_PIPE)
                return -EADDRNOTAVAIL;

        conn_info = ndev->hci_dev->conn_info;
        if (!conn_info)
                return -EPROTO;

        data.conn_id = conn_info->conn_id;
        data.pipe = pipe;
        data.cmd = NCI_HCP_HEADER(NCI_HCI_HCP_COMMAND, cmd);
        data.data = param;
        data.data_len = param_len;

        r = nci_request(ndev, nci_hci_send_data_req, &data,
                        msecs_to_jiffies(NCI_DATA_TIMEOUT));
        if (r == NCI_STATUS_OK) {
                message = (struct nci_hcp_message *)conn_info->rx_skb->data;
                r = nci_hci_result_to_errno(
                        NCI_HCP_MSG_GET_CMD(message->header));
                skb_pull(conn_info->rx_skb, NCI_HCI_HCP_MESSAGE_HEADER_LEN);

                if (!r && skb)
                        *skb = conn_info->rx_skb;
        }

        return r;
}
EXPORT_SYMBOL(nci_hci_send_cmd);

int nci_hci_clear_all_pipes(struct nci_dev *ndev)
{
        int r;

        r = nci_hci_send_cmd(ndev, NCI_HCI_ADMIN_GATE,
                             NCI_HCI_ADM_CLEAR_ALL_PIPE, NULL, 0, NULL);
        if (r < 0)
                return r;

        nci_hci_reset_pipes(ndev->hci_dev);
        return r;
}
EXPORT_SYMBOL(nci_hci_clear_all_pipes);

static void nci_hci_event_received(struct nci_dev *ndev, u8 pipe,
                                   u8 event, struct sk_buff *skb)
{
        if (ndev->ops->hci_event_received)
                ndev->ops->hci_event_received(ndev, pipe, event, skb);
}

static void nci_hci_cmd_received(struct nci_dev *ndev, u8 pipe,
                                 u8 cmd, struct sk_buff *skb)
{
        u8 gate = ndev->hci_dev->pipes[pipe].gate;
        u8 status = NCI_HCI_ANY_OK | ~NCI_HCI_FRAGMENT;
        u8 dest_gate, new_pipe;
        struct nci_hci_create_pipe_resp *create_info;
        struct nci_hci_delete_pipe_noti *delete_info;
        struct nci_hci_all_pipe_cleared_noti *cleared_info;

        pr_debug("from gate %x pipe %x cmd %x\n", gate, pipe, cmd);

        switch (cmd) {
        case NCI_HCI_ADM_NOTIFY_PIPE_CREATED:
                if (skb->len != 5) {
                        status = NCI_HCI_ANY_E_NOK;
                        goto exit;
                }
                create_info = (struct nci_hci_create_pipe_resp *)skb->data;
                dest_gate = create_info->dest_gate;
                new_pipe = create_info->pipe;
                if (new_pipe >= NCI_HCI_MAX_PIPES) {
                        status = NCI_HCI_ANY_E_NOK;
                        goto exit;
                }

                /* Save the new created pipe and bind with local gate,
                 * the description for skb->data[3] is destination gate id
                 * but since we received this cmd from host controller, we
                 * are the destination and it is our local gate
                 */
                ndev->hci_dev->gate2pipe[dest_gate] = new_pipe;
                ndev->hci_dev->pipes[new_pipe].gate = dest_gate;
                ndev->hci_dev->pipes[new_pipe].host =
                                                create_info->src_host;
                break;
        case NCI_HCI_ANY_OPEN_PIPE:
                /* If the pipe is not created report an error */
                if (gate == NCI_HCI_INVALID_GATE) {
                        status = NCI_HCI_ANY_E_NOK;
                        goto exit;
                }
                break;
        case NCI_HCI_ADM_NOTIFY_PIPE_DELETED:
                if (skb->len != 1) {
                        status = NCI_HCI_ANY_E_NOK;
                        goto exit;
                }
                delete_info = (struct nci_hci_delete_pipe_noti *)skb->data;
                if (delete_info->pipe >= NCI_HCI_MAX_PIPES) {
                        status = NCI_HCI_ANY_E_NOK;
                        goto exit;
                }

                ndev->hci_dev->pipes[delete_info->pipe].gate =
                                                NCI_HCI_INVALID_GATE;
                ndev->hci_dev->pipes[delete_info->pipe].host =
                                                NCI_HCI_INVALID_HOST;
                break;
        case NCI_HCI_ADM_NOTIFY_ALL_PIPE_CLEARED:
                if (skb->len != 1) {
                        status = NCI_HCI_ANY_E_NOK;
                        goto exit;
                }

                cleared_info =
                        (struct nci_hci_all_pipe_cleared_noti *)skb->data;
                nci_hci_reset_pipes_per_host(ndev, cleared_info->host);
                break;
        default:
                pr_debug("Discarded unknown cmd %x to gate %x\n", cmd, gate);
                break;
        }

        if (ndev->ops->hci_cmd_received)
                ndev->ops->hci_cmd_received(ndev, pipe, cmd, skb);

exit:
        nci_hci_send_data(ndev, pipe, status, NULL, 0);

        kfree_skb(skb);
}

static void nci_hci_resp_received(struct nci_dev *ndev, u8 pipe,
                                  struct sk_buff *skb)
{
        struct nci_conn_info *conn_info;

        conn_info = ndev->hci_dev->conn_info;
        if (!conn_info)
                goto exit;

        conn_info->rx_skb = skb;

exit:
        nci_req_complete(ndev, NCI_STATUS_OK);
}

/* Receive hcp message for pipe, with type and cmd.
 * skb contains optional message data only.
 */
static void nci_hci_hcp_message_rx(struct nci_dev *ndev, u8 pipe,
                                   u8 type, u8 instruction, struct sk_buff *skb)
{
        switch (type) {
        case NCI_HCI_HCP_RESPONSE:
                nci_hci_resp_received(ndev, pipe, skb);
                break;
        case NCI_HCI_HCP_COMMAND:
                nci_hci_cmd_received(ndev, pipe, instruction, skb);
                break;
        case NCI_HCI_HCP_EVENT:
                nci_hci_event_received(ndev, pipe, instruction, skb);
                break;
        default:
                pr_err("UNKNOWN MSG Type %d, instruction=%d\n",
                       type, instruction);
                kfree_skb(skb);
                break;
        }

        nci_req_complete(ndev, NCI_STATUS_OK);
}

static void nci_hci_msg_rx_work(struct work_struct *work)
{
        struct nci_hci_dev *hdev =
                container_of(work, struct nci_hci_dev, msg_rx_work);
        struct sk_buff *skb;
        const struct nci_hcp_message *message;
        u8 pipe, type, instruction;

        for (; (skb = skb_dequeue(&hdev->msg_rx_queue)); kcov_remote_stop()) {
                kcov_remote_start_common(skb_get_kcov_handle(skb));
                pipe = NCI_HCP_MSG_GET_PIPE(skb->data[0]);
                skb_pull(skb, NCI_HCI_HCP_PACKET_HEADER_LEN);
                message = (struct nci_hcp_message *)skb->data;
                type = NCI_HCP_MSG_GET_TYPE(message->header);
                instruction = NCI_HCP_MSG_GET_CMD(message->header);
                skb_pull(skb, NCI_HCI_HCP_MESSAGE_HEADER_LEN);

                nci_hci_hcp_message_rx(hdev->ndev, pipe,
                                       type, instruction, skb);
        }
}

void nci_hci_data_received_cb(void *context,
                              struct sk_buff *skb, int err)
{
        struct nci_dev *ndev = (struct nci_dev *)context;
        struct nci_hcp_packet *packet;
        u8 pipe, type;
        struct sk_buff *hcp_skb;
        struct sk_buff *frag_skb;
        int msg_len;

        if (err) {
                nci_req_complete(ndev, err);
                return;
        }

        packet = (struct nci_hcp_packet *)skb->data;
        if ((packet->header & ~NCI_HCI_FRAGMENT) == 0) {
                skb_queue_tail(&ndev->hci_dev->rx_hcp_frags, skb);
                return;
        }

        /* it's the last fragment. Does it need re-aggregation? */
        if (skb_queue_len(&ndev->hci_dev->rx_hcp_frags)) {
                pipe = NCI_HCP_MSG_GET_PIPE(packet->header);
                skb_queue_tail(&ndev->hci_dev->rx_hcp_frags, skb);

                msg_len = 0;
                skb_queue_walk(&ndev->hci_dev->rx_hcp_frags, frag_skb) {
                        msg_len += (frag_skb->len -
                                    NCI_HCI_HCP_PACKET_HEADER_LEN);
                }

                hcp_skb = nfc_alloc_recv_skb(NCI_HCI_HCP_PACKET_HEADER_LEN +
                                             msg_len, GFP_KERNEL);
                if (!hcp_skb) {
                        nci_req_complete(ndev, -ENOMEM);
                        return;
                }

                skb_put_u8(hcp_skb, pipe);

                skb_queue_walk(&ndev->hci_dev->rx_hcp_frags, frag_skb) {
                        msg_len = frag_skb->len - NCI_HCI_HCP_PACKET_HEADER_LEN;
                        skb_put_data(hcp_skb,
                                     frag_skb->data + NCI_HCI_HCP_PACKET_HEADER_LEN,
                                     msg_len);
                }

                skb_queue_purge(&ndev->hci_dev->rx_hcp_frags);
        } else {
                packet->header &= NCI_HCI_FRAGMENT;
                hcp_skb = skb;
        }

        /* if this is a response, dispatch immediately to
         * unblock waiting cmd context. Otherwise, enqueue to dispatch
         * in separate context where handler can also execute command.
         */
        packet = (struct nci_hcp_packet *)hcp_skb->data;
        type = NCI_HCP_MSG_GET_TYPE(packet->message.header);
        if (type == NCI_HCI_HCP_RESPONSE) {
                pipe = NCI_HCP_MSG_GET_PIPE(packet->header);
                skb_pull(hcp_skb, NCI_HCI_HCP_PACKET_HEADER_LEN);
                nci_hci_hcp_message_rx(ndev, pipe, type,
                                       NCI_STATUS_OK, hcp_skb);
        } else {
                skb_queue_tail(&ndev->hci_dev->msg_rx_queue, hcp_skb);
                schedule_work(&ndev->hci_dev->msg_rx_work);
        }
}

int nci_hci_open_pipe(struct nci_dev *ndev, u8 pipe)
{
        struct nci_data data;
        const struct nci_conn_info *conn_info;

        conn_info = ndev->hci_dev->conn_info;
        if (!conn_info)
                return -EPROTO;

        data.conn_id = conn_info->conn_id;
        data.pipe = pipe;
        data.cmd = NCI_HCP_HEADER(NCI_HCI_HCP_COMMAND,
                                       NCI_HCI_ANY_OPEN_PIPE);
        data.data = NULL;
        data.data_len = 0;

        return nci_request(ndev, nci_hci_send_data_req, &data,
                           msecs_to_jiffies(NCI_DATA_TIMEOUT));
}
EXPORT_SYMBOL(nci_hci_open_pipe);

static u8 nci_hci_create_pipe(struct nci_dev *ndev, u8 dest_host,
                              u8 dest_gate, int *result)
{
        u8 pipe;
        struct sk_buff *skb;
        struct nci_hci_create_pipe_params params;
        const struct nci_hci_create_pipe_resp *resp;

        pr_debug("gate=%d\n", dest_gate);

        params.src_gate = NCI_HCI_ADMIN_GATE;
        params.dest_host = dest_host;
        params.dest_gate = dest_gate;

        *result = nci_hci_send_cmd(ndev, NCI_HCI_ADMIN_GATE,
                                   NCI_HCI_ADM_CREATE_PIPE,
                                   (u8 *)&params, sizeof(params), &skb);
        if (*result < 0)
                return NCI_HCI_INVALID_PIPE;

        resp = (struct nci_hci_create_pipe_resp *)skb->data;
        pipe = resp->pipe;
        kfree_skb(skb);

        pr_debug("pipe created=%d\n", pipe);

        if (pipe >= NCI_HCI_MAX_PIPES)
                pipe = NCI_HCI_INVALID_PIPE;
        return pipe;
}

static int nci_hci_delete_pipe(struct nci_dev *ndev, u8 pipe)
{
        return nci_hci_send_cmd(ndev, NCI_HCI_ADMIN_GATE,
                                NCI_HCI_ADM_DELETE_PIPE, &pipe, 1, NULL);
}

int nci_hci_set_param(struct nci_dev *ndev, u8 gate, u8 idx,
                      const u8 *param, size_t param_len)
{
        const struct nci_hcp_message *message;
        const struct nci_conn_info *conn_info;
        struct nci_data data;
        int r;
        u8 *tmp;
        u8 pipe = ndev->hci_dev->gate2pipe[gate];

        pr_debug("idx=%d to gate %d\n", idx, gate);

        if (pipe == NCI_HCI_INVALID_PIPE)
                return -EADDRNOTAVAIL;

        conn_info = ndev->hci_dev->conn_info;
        if (!conn_info)
                return -EPROTO;

        tmp = kmalloc(1 + param_len, GFP_KERNEL);
        if (!tmp)
                return -ENOMEM;

        *tmp = idx;
        memcpy(tmp + 1, param, param_len);

        data.conn_id = conn_info->conn_id;
        data.pipe = pipe;
        data.cmd = NCI_HCP_HEADER(NCI_HCI_HCP_COMMAND,
                                       NCI_HCI_ANY_SET_PARAMETER);
        data.data = tmp;
        data.data_len = param_len + 1;

        r = nci_request(ndev, nci_hci_send_data_req, &data,
                        msecs_to_jiffies(NCI_DATA_TIMEOUT));
        if (r == NCI_STATUS_OK) {
                message = (struct nci_hcp_message *)conn_info->rx_skb->data;
                r = nci_hci_result_to_errno(
                        NCI_HCP_MSG_GET_CMD(message->header));
                skb_pull(conn_info->rx_skb, NCI_HCI_HCP_MESSAGE_HEADER_LEN);
        }

        kfree(tmp);
        return r;
}
EXPORT_SYMBOL(nci_hci_set_param);

int nci_hci_get_param(struct nci_dev *ndev, u8 gate, u8 idx,
                      struct sk_buff **skb)
{
        const struct nci_hcp_message *message;
        const struct nci_conn_info *conn_info;
        struct nci_data data;
        int r;
        u8 pipe = ndev->hci_dev->gate2pipe[gate];

        pr_debug("idx=%d to gate %d\n", idx, gate);

        if (pipe == NCI_HCI_INVALID_PIPE)
                return -EADDRNOTAVAIL;

        conn_info = ndev->hci_dev->conn_info;
        if (!conn_info)
                return -EPROTO;

        data.conn_id = conn_info->conn_id;
        data.pipe = pipe;
        data.cmd = NCI_HCP_HEADER(NCI_HCI_HCP_COMMAND,
                                  NCI_HCI_ANY_GET_PARAMETER);
        data.data = &idx;
        data.data_len = 1;

        r = nci_request(ndev, nci_hci_send_data_req, &data,
                        msecs_to_jiffies(NCI_DATA_TIMEOUT));

        if (r == NCI_STATUS_OK) {
                message = (struct nci_hcp_message *)conn_info->rx_skb->data;
                r = nci_hci_result_to_errno(
                        NCI_HCP_MSG_GET_CMD(message->header));
                skb_pull(conn_info->rx_skb, NCI_HCI_HCP_MESSAGE_HEADER_LEN);

                if (!r && skb)
                        *skb = conn_info->rx_skb;
        }

        return r;
}
EXPORT_SYMBOL(nci_hci_get_param);

int nci_hci_connect_gate(struct nci_dev *ndev,
                         u8 dest_host, u8 dest_gate, u8 pipe)
{
        bool pipe_created = false;
        int r;

        if (pipe == NCI_HCI_DO_NOT_OPEN_PIPE)
                return 0;

        if (ndev->hci_dev->gate2pipe[dest_gate] != NCI_HCI_INVALID_PIPE)
                return -EADDRINUSE;

        if (pipe != NCI_HCI_INVALID_PIPE)
                goto open_pipe;

        switch (dest_gate) {
        case NCI_HCI_LINK_MGMT_GATE:
                pipe = NCI_HCI_LINK_MGMT_PIPE;
        break;
        case NCI_HCI_ADMIN_GATE:
                pipe = NCI_HCI_ADMIN_PIPE;
        break;
        default:
                pipe = nci_hci_create_pipe(ndev, dest_host, dest_gate, &r);
                if (pipe == NCI_HCI_INVALID_PIPE)
                        return r;
                pipe_created = true;
                break;
        }

open_pipe:
        r = nci_hci_open_pipe(ndev, pipe);
        if (r < 0) {
                if (pipe_created) {
                        if (nci_hci_delete_pipe(ndev, pipe) < 0) {
                                /* TODO: Cannot clean by deleting pipe...
                                 * -> inconsistent state
                                 */
                        }
                }
                return r;
        }

        ndev->hci_dev->pipes[pipe].gate = dest_gate;
        ndev->hci_dev->pipes[pipe].host = dest_host;
        ndev->hci_dev->gate2pipe[dest_gate] = pipe;

        return 0;
}
EXPORT_SYMBOL(nci_hci_connect_gate);

static int nci_hci_dev_connect_gates(struct nci_dev *ndev,
                                     u8 gate_count,
                                     const struct nci_hci_gate *gates)
{
        int r;

        while (gate_count--) {
                r = nci_hci_connect_gate(ndev, gates->dest_host,
                                         gates->gate, gates->pipe);
                if (r < 0)
                        return r;
                gates++;
        }

        return 0;
}

int nci_hci_dev_session_init(struct nci_dev *ndev)
{
        struct nci_conn_info *conn_info;
        struct sk_buff *skb;
        int r;

        ndev->hci_dev->count_pipes = 0;
        ndev->hci_dev->expected_pipes = 0;

        conn_info = ndev->hci_dev->conn_info;
        if (!conn_info)
                return -EPROTO;

        conn_info->data_exchange_cb = nci_hci_data_received_cb;
        conn_info->data_exchange_cb_context = ndev;

        nci_hci_reset_pipes(ndev->hci_dev);

        if (ndev->hci_dev->init_data.gates[0].gate != NCI_HCI_ADMIN_GATE)
                return -EPROTO;

        r = nci_hci_connect_gate(ndev,
                                 ndev->hci_dev->init_data.gates[0].dest_host,
                                 ndev->hci_dev->init_data.gates[0].gate,
                                 ndev->hci_dev->init_data.gates[0].pipe);
        if (r < 0)
                return r;

        r = nci_hci_get_param(ndev, NCI_HCI_ADMIN_GATE,
                              NCI_HCI_ADMIN_PARAM_SESSION_IDENTITY, &skb);
        if (r < 0)
                return r;

        if (skb->len &&
            skb->len == strlen(ndev->hci_dev->init_data.session_id) &&
            !memcmp(ndev->hci_dev->init_data.session_id, skb->data, skb->len) &&
            ndev->ops->hci_load_session) {
                /* Restore gate<->pipe table from some proprietary location. */
                r = ndev->ops->hci_load_session(ndev);
        } else {
                r = nci_hci_clear_all_pipes(ndev);
                if (r < 0)
                        goto exit;

                r = nci_hci_dev_connect_gates(ndev,
                                              ndev->hci_dev->init_data.gate_count,
                                              ndev->hci_dev->init_data.gates);
                if (r < 0)
                        goto exit;

                r = nci_hci_set_param(ndev, NCI_HCI_ADMIN_GATE,
                                      NCI_HCI_ADMIN_PARAM_SESSION_IDENTITY,
                                      ndev->hci_dev->init_data.session_id,
                                      strlen(ndev->hci_dev->init_data.session_id));
        }

exit:
        kfree_skb(skb);

        return r;
}
EXPORT_SYMBOL(nci_hci_dev_session_init);

struct nci_hci_dev *nci_hci_allocate(struct nci_dev *ndev)
{
        struct nci_hci_dev *hdev;

        hdev = kzalloc_obj(*hdev);
        if (!hdev)
                return NULL;

        skb_queue_head_init(&hdev->rx_hcp_frags);
        INIT_WORK(&hdev->msg_rx_work, nci_hci_msg_rx_work);
        skb_queue_head_init(&hdev->msg_rx_queue);
        hdev->ndev = ndev;

        return hdev;
}

void nci_hci_deallocate(struct nci_dev *ndev)
{
        kfree(ndev->hci_dev);
}