usbip_common.h

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/*
 * Copyright (C) 2003-2008 Takahiro Hirofuchi
 *
 * This 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 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.
 */

#ifndef __USBIP_COMMON_H
#define __USBIP_COMMON_H

#include <linux/compiler.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/net.h>
#include <linux/printk.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/usb.h>
#include <linux/wait.h>

#define USBIP_VERSION "1.0.0"

#undef pr_fmt

#ifdef DEBUG
#define pr_fmt(fmt)     KBUILD_MODNAME ": %s:%d: " fmt, __func__, __LINE__
#else
#define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
#endif

enum {
    usbip_debug_xmit    = (1 << 0),
    usbip_debug_sysfs   = (1 << 1),
    usbip_debug_urb     = (1 << 2),
    usbip_debug_eh      = (1 << 3),

    usbip_debug_stub_cmp    = (1 << 8),
    usbip_debug_stub_dev    = (1 << 9),
    usbip_debug_stub_rx = (1 << 10),
    usbip_debug_stub_tx = (1 << 11),

    usbip_debug_vhci_rh = (1 << 8),
    usbip_debug_vhci_hc = (1 << 9),
    usbip_debug_vhci_rx = (1 << 10),
    usbip_debug_vhci_tx = (1 << 11),
    usbip_debug_vhci_sysfs  = (1 << 12)
};

#define usbip_dbg_flag_xmit (usbip_debug_flag & usbip_debug_xmit)
#define usbip_dbg_flag_vhci_rh  (usbip_debug_flag & usbip_debug_vhci_rh)
#define usbip_dbg_flag_vhci_hc  (usbip_debug_flag & usbip_debug_vhci_hc)
#define usbip_dbg_flag_vhci_rx  (usbip_debug_flag & usbip_debug_vhci_rx)
#define usbip_dbg_flag_vhci_tx  (usbip_debug_flag & usbip_debug_vhci_tx)
#define usbip_dbg_flag_stub_rx  (usbip_debug_flag & usbip_debug_stub_rx)
#define usbip_dbg_flag_stub_tx  (usbip_debug_flag & usbip_debug_stub_tx)
#define usbip_dbg_flag_vhci_sysfs  (usbip_debug_flag & usbip_debug_vhci_sysfs)

extern unsigned long usbip_debug_flag;
extern struct device_attribute dev_attr_usbip_debug;

#define usbip_dbg_with_flag(flag, fmt, args...)     \
    do {                        \
        if (flag & usbip_debug_flag)        \
            pr_debug(fmt, ##args);      \
    } while (0)

#define usbip_dbg_sysfs(fmt, args...) \
    usbip_dbg_with_flag(usbip_debug_sysfs, fmt , ##args)
#define usbip_dbg_xmit(fmt, args...) \
    usbip_dbg_with_flag(usbip_debug_xmit, fmt , ##args)
#define usbip_dbg_urb(fmt, args...) \
    usbip_dbg_with_flag(usbip_debug_urb, fmt , ##args)
#define usbip_dbg_eh(fmt, args...) \
    usbip_dbg_with_flag(usbip_debug_eh, fmt , ##args)

#define usbip_dbg_vhci_rh(fmt, args...) \
    usbip_dbg_with_flag(usbip_debug_vhci_rh, fmt , ##args)
#define usbip_dbg_vhci_hc(fmt, args...) \
    usbip_dbg_with_flag(usbip_debug_vhci_hc, fmt , ##args)
#define usbip_dbg_vhci_rx(fmt, args...) \
    usbip_dbg_with_flag(usbip_debug_vhci_rx, fmt , ##args)
#define usbip_dbg_vhci_tx(fmt, args...) \
    usbip_dbg_with_flag(usbip_debug_vhci_tx, fmt , ##args)
#define usbip_dbg_vhci_sysfs(fmt, args...) \
    usbip_dbg_with_flag(usbip_debug_vhci_sysfs, fmt , ##args)

#define usbip_dbg_stub_cmp(fmt, args...) \
    usbip_dbg_with_flag(usbip_debug_stub_cmp, fmt , ##args)
#define usbip_dbg_stub_rx(fmt, args...) \
    usbip_dbg_with_flag(usbip_debug_stub_rx, fmt , ##args)
#define usbip_dbg_stub_tx(fmt, args...) \
    usbip_dbg_with_flag(usbip_debug_stub_tx, fmt , ##args)

/*
 * USB/IP request headers
 *
 * Each request is transferred across the network to its counterpart, which
 * facilitates the normal USB communication. The values contained in the headers
 * are basically the same as in a URB. Currently, four request types are
 * defined:
 *
 *  - USBIP_CMD_SUBMIT: a USB request block, corresponds to usb_submit_urb()
 *    (client to server)
 *
 *  - USBIP_RET_SUBMIT: the result of USBIP_CMD_SUBMIT
 *    (server to client)
 *
 *  - USBIP_CMD_UNLINK: an unlink request of a pending USBIP_CMD_SUBMIT,
 *    corresponds to usb_unlink_urb()
 *    (client to server)
 *
 *  - USBIP_RET_UNLINK: the result of USBIP_CMD_UNLINK
 *    (server to client)
 *
 */
#define USBIP_CMD_SUBMIT    0x0001
#define USBIP_CMD_UNLINK    0x0002
#define USBIP_RET_SUBMIT    0x0003
#define USBIP_RET_UNLINK    0x0004

#define USBIP_DIR_OUT   0x00
#define USBIP_DIR_IN    0x01

struct usbip_header_basic {
    __u32 command;
    __u32 seqnum;
    __u32 devid;
    __u32 direction;
    __u32 ep;
} __packed;

struct usbip_header_cmd_submit {
    __u32 transfer_flags;
    __s32 transfer_buffer_length;

    /* it is difficult for usbip to sync frames (reserved only?) */
    __s32 start_frame;
    __s32 number_of_packets;
    __s32 interval;

    unsigned char setup[8];
} __packed;

struct usbip_header_ret_submit {
    __s32 status;
    __s32 actual_length;
    __s32 start_frame;
    __s32 number_of_packets;
    __s32 error_count;
} __packed;

struct usbip_header_cmd_unlink {
    __u32 seqnum;
} __packed;

struct usbip_header_ret_unlink {
    __s32 status;
} __packed;

struct usbip_header {
    struct usbip_header_basic base;

    union {
        struct usbip_header_cmd_submit  cmd_submit;
        struct usbip_header_ret_submit  ret_submit;
        struct usbip_header_cmd_unlink  cmd_unlink;
        struct usbip_header_ret_unlink  ret_unlink;
    } u;
} __packed;

/*
 * This is the same as usb_iso_packet_descriptor but packed for pdu.
 */
struct usbip_iso_packet_descriptor {
    __u32 offset;
    __u32 length;           /* expected length */
    __u32 actual_length;
    __u32 status;
} __packed;

enum usbip_side {
    USBIP_VHCI,
    USBIP_STUB,
};

enum usbip_status {
    /* sdev is available. */
    SDEV_ST_AVAILABLE = 0x01,
    /* sdev is now used. */
    SDEV_ST_USED,
    /* sdev is unusable because of a fatal error. */
    SDEV_ST_ERROR,

    /* vdev does not connect a remote device. */
    VDEV_ST_NULL,
    /* vdev is used, but the USB address is not assigned yet */
    VDEV_ST_NOTASSIGNED,
    VDEV_ST_USED,
    VDEV_ST_ERROR
};

/* event handler */
#define USBIP_EH_SHUTDOWN   (1 << 0)
#define USBIP_EH_BYE        (1 << 1)
#define USBIP_EH_RESET      (1 << 2)
#define USBIP_EH_UNUSABLE   (1 << 3)

#define SDEV_EVENT_REMOVED   (USBIP_EH_SHUTDOWN | USBIP_EH_RESET | USBIP_EH_BYE)
#define SDEV_EVENT_DOWN     (USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
#define SDEV_EVENT_ERROR_TCP    (USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
#define SDEV_EVENT_ERROR_SUBMIT (USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
#define SDEV_EVENT_ERROR_MALLOC (USBIP_EH_SHUTDOWN | USBIP_EH_UNUSABLE)

#define VDEV_EVENT_REMOVED  (USBIP_EH_SHUTDOWN | USBIP_EH_BYE)
#define VDEV_EVENT_DOWN     (USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
#define VDEV_EVENT_ERROR_TCP    (USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
#define VDEV_EVENT_ERROR_MALLOC (USBIP_EH_SHUTDOWN | USBIP_EH_UNUSABLE)

/* a common structure for stub_device and vhci_device */
struct usbip_device {
    enum usbip_side side;
    enum usbip_status status;

    /* lock for status */
    spinlock_t lock;

    struct socket *tcp_socket;

    struct task_struct *tcp_rx;
    struct task_struct *tcp_tx;

    unsigned long event;
    struct task_struct *eh;
    wait_queue_head_t eh_waitq;

    struct eh_ops {
        void (*shutdown)(struct usbip_device *);
        void (*reset)(struct usbip_device *);
        void (*unusable)(struct usbip_device *);
    } eh_ops;
};

#define kthread_get_run(threadfn, data, namefmt, ...)              \
({                                     \
    struct task_struct *__k                        \
        = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
    if (!IS_ERR(__k)) {                        \
        get_task_struct(__k);                      \
        wake_up_process(__k);                      \
    }                                  \
    __k;                                   \
})

#define kthread_stop_put(k)     \
    do {                \
        kthread_stop(k);    \
        put_task_struct(k); \
    } while (0)

/* usbip_common.c */
void usbip_dump_urb(struct urb *purb);
void usbip_dump_header(struct usbip_header *pdu);

int usbip_recv(struct socket *sock, void *buf, int size);
struct socket *sockfd_to_socket(unsigned int sockfd);

void usbip_pack_pdu(struct usbip_header *pdu, struct urb *urb, int cmd,
            int pack);
void usbip_header_correct_endian(struct usbip_header *pdu, int send);

void *usbip_alloc_iso_desc_pdu(struct urb *urb, ssize_t *bufflen);
/* some members of urb must be substituted before. */
int usbip_recv_iso(struct usbip_device *ud, struct urb *urb);
void usbip_pad_iso(struct usbip_device *ud, struct urb *urb);
int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb);

/* usbip_event.c */
int usbip_start_eh(struct usbip_device *ud);
void usbip_stop_eh(struct usbip_device *ud);
void usbip_event_add(struct usbip_device *ud, unsigned long event);
int usbip_event_happened(struct usbip_device *ud);

static inline int interface_to_busnum(struct usb_interface *interface)
{
    struct usb_device *udev = interface_to_usbdev(interface);
    return udev->bus->busnum;
}

static inline int interface_to_devnum(struct usb_interface *interface)
{
    struct usb_device *udev = interface_to_usbdev(interface);
    return udev->devnum;
}

#endif /* __USBIP_COMMON_H */