address.c

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/*
 * Ultra Wide Band
 * Address management
 *
 * Copyright (C) 2005-2006 Intel Corporation
 * Inaky Perez-Gonzalez <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 *
 * FIXME: docs
 */

#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/random.h>
#include <linux/etherdevice.h>

#include "uwb-internal.h"


struct uwb_rc_cmd_dev_addr_mgmt {
    struct uwb_rccb rccb;
    u8 bmOperationType;
    u8 baAddr[6];
} __attribute__((packed));


static
int uwb_rc_dev_addr_mgmt(struct uwb_rc *rc,
             u8 bmOperationType, const u8 *baAddr,
             struct uwb_rc_evt_dev_addr_mgmt *reply)
{
    int result;
    struct uwb_rc_cmd_dev_addr_mgmt *cmd;

    result = -ENOMEM;
    cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
    if (cmd == NULL)
        goto error_kzalloc;
    cmd->rccb.bCommandType = UWB_RC_CET_GENERAL;
    cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_DEV_ADDR_MGMT);
    cmd->bmOperationType = bmOperationType;
    if (baAddr) {
        size_t size = 0;
        switch (bmOperationType >> 1) {
        case 0: size = 2; break;
        case 1: size = 6; break;
        default: BUG();
        }
        memcpy(cmd->baAddr, baAddr, size);
    }
    reply->rceb.bEventType = UWB_RC_CET_GENERAL;
    reply->rceb.wEvent = UWB_RC_CMD_DEV_ADDR_MGMT;
    result = uwb_rc_cmd(rc, "DEV-ADDR-MGMT",
                &cmd->rccb, sizeof(*cmd),
                &reply->rceb, sizeof(*reply));
    if (result < 0)
        goto error_cmd;
    if (result < sizeof(*reply)) {
        dev_err(&rc->uwb_dev.dev,
            "DEV-ADDR-MGMT: not enough data replied: "
            "%d vs %zu bytes needed\n", result, sizeof(*reply));
        result = -ENOMSG;
    } else if (reply->bResultCode != UWB_RC_RES_SUCCESS) {
        dev_err(&rc->uwb_dev.dev,
            "DEV-ADDR-MGMT: command execution failed: %s (%d)\n",
            uwb_rc_strerror(reply->bResultCode),
            reply->bResultCode);
        result = -EIO;
    } else
        result = 0;
error_cmd:
    kfree(cmd);
error_kzalloc:
    return result;
}


static int uwb_rc_addr_set(struct uwb_rc *rc,
            const void *_addr, enum uwb_addr_type type)
{
    int result;
    u8 bmOperationType = 0x1;       /* Set address */
    const struct uwb_dev_addr *dev_addr = _addr;
    const struct uwb_mac_addr *mac_addr = _addr;
    struct uwb_rc_evt_dev_addr_mgmt reply;
    const u8 *baAddr;

    result = -EINVAL;
    switch (type) {
    case UWB_ADDR_DEV:
        baAddr = dev_addr->data;
        break;
    case UWB_ADDR_MAC:
        baAddr = mac_addr->data;
        bmOperationType |= 0x2;
        break;
    default:
        return result;
    }
    return uwb_rc_dev_addr_mgmt(rc, bmOperationType, baAddr, &reply);
}


static int uwb_rc_addr_get(struct uwb_rc *rc,
            void *_addr, enum uwb_addr_type type)
{
    int result;
    u8 bmOperationType = 0x0;       /* Get address */
    struct uwb_rc_evt_dev_addr_mgmt evt;
    struct uwb_dev_addr *dev_addr = _addr;
    struct uwb_mac_addr *mac_addr = _addr;
    u8 *baAddr;

    result = -EINVAL;
    switch (type) {
    case UWB_ADDR_DEV:
        baAddr = dev_addr->data;
        break;
    case UWB_ADDR_MAC:
        bmOperationType |= 0x2;
        baAddr = mac_addr->data;
        break;
    default:
        return result;
    }
    result = uwb_rc_dev_addr_mgmt(rc, bmOperationType, baAddr, &evt);
    if (result == 0)
        switch (type) {
        case UWB_ADDR_DEV:
            memcpy(&dev_addr->data, evt.baAddr,
                   sizeof(dev_addr->data));
            break;
        case UWB_ADDR_MAC:
            memcpy(&mac_addr->data, evt.baAddr,
                   sizeof(mac_addr->data));
            break;
        default:        /* shut gcc up */
            BUG();
        }
    return result;
}


int uwb_rc_mac_addr_get(struct uwb_rc *rc,
            struct uwb_mac_addr *addr) {
    return uwb_rc_addr_get(rc, addr, UWB_ADDR_MAC);
}
EXPORT_SYMBOL_GPL(uwb_rc_mac_addr_get);


int uwb_rc_dev_addr_get(struct uwb_rc *rc,
            struct uwb_dev_addr *addr) {
    return uwb_rc_addr_get(rc, addr, UWB_ADDR_DEV);
}
EXPORT_SYMBOL_GPL(uwb_rc_dev_addr_get);


int uwb_rc_mac_addr_set(struct uwb_rc *rc,
            const struct uwb_mac_addr *addr)
{
    int result = -EINVAL;
    mutex_lock(&rc->uwb_dev.mutex);
    result = uwb_rc_addr_set(rc, addr, UWB_ADDR_MAC);
    mutex_unlock(&rc->uwb_dev.mutex);
    return result;
}


int uwb_rc_dev_addr_set(struct uwb_rc *rc,
            const struct uwb_dev_addr *addr)
{
    int result = -EINVAL;
    mutex_lock(&rc->uwb_dev.mutex);
    result = uwb_rc_addr_set(rc, addr, UWB_ADDR_DEV);
    rc->uwb_dev.dev_addr = *addr;
    mutex_unlock(&rc->uwb_dev.mutex);
    return result;
}

/* Returns !0 if given address is already assigned to device. */
int __uwb_mac_addr_assigned_check(struct device *dev, void *_addr)
{
    struct uwb_dev *uwb_dev = to_uwb_dev(dev);
    struct uwb_mac_addr *addr = _addr;

    if (!uwb_mac_addr_cmp(addr, &uwb_dev->mac_addr))
        return !0;
    return 0;
}

/* Returns !0 if given address is already assigned to device. */
int __uwb_dev_addr_assigned_check(struct device *dev, void *_addr)
{
    struct uwb_dev *uwb_dev = to_uwb_dev(dev);
    struct uwb_dev_addr *addr = _addr;
    if (!uwb_dev_addr_cmp(addr, &uwb_dev->dev_addr))
        return !0;
    return 0;
}

int uwb_rc_dev_addr_assign(struct uwb_rc *rc)
{
    struct uwb_dev_addr new_addr;

    do {
        get_random_bytes(new_addr.data, sizeof(new_addr.data));
    } while (new_addr.data[0] == 0x00 || new_addr.data[0] == 0xff
         || __uwb_dev_addr_assigned(rc, &new_addr));

    return uwb_rc_dev_addr_set(rc, &new_addr);
}

int uwbd_evt_handle_rc_dev_addr_conflict(struct uwb_event *evt)
{
    struct uwb_rc *rc = evt->rc;

    return uwb_rc_dev_addr_assign(rc);
}

/*
 * Print the 48-bit EUI MAC address of the radio controller when
 * reading /sys/class/uwb_rc/XX/mac_address
 */
static ssize_t uwb_rc_mac_addr_show(struct device *dev,
                    struct device_attribute *attr, char *buf)
{
    struct uwb_dev *uwb_dev = to_uwb_dev(dev);
    struct uwb_rc *rc = uwb_dev->rc;
    struct uwb_mac_addr addr;
    ssize_t result;

    mutex_lock(&rc->uwb_dev.mutex);
    result = uwb_rc_addr_get(rc, &addr, UWB_ADDR_MAC);
    mutex_unlock(&rc->uwb_dev.mutex);
    if (result >= 0) {
        result = uwb_mac_addr_print(buf, UWB_ADDR_STRSIZE, &addr);
        buf[result++] = '\n';
    }
    return result;
}

/*
 * Parse a 48 bit address written to /sys/class/uwb_rc/XX/mac_address
 * and if correct, set it.
 */
static ssize_t uwb_rc_mac_addr_store(struct device *dev,
                     struct device_attribute *attr,
                     const char *buf, size_t size)
{
    struct uwb_dev *uwb_dev = to_uwb_dev(dev);
    struct uwb_rc *rc = uwb_dev->rc;
    struct uwb_mac_addr addr;
    ssize_t result;

    result = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx\n",
            &addr.data[0], &addr.data[1], &addr.data[2],
            &addr.data[3], &addr.data[4], &addr.data[5]);
    if (result != 6) {
        result = -EINVAL;
        goto out;
    }
    if (is_multicast_ether_addr(addr.data)) {
        dev_err(&rc->uwb_dev.dev, "refusing to set multicast "
            "MAC address %s\n", buf);
        result = -EINVAL;
        goto out;
    }
    result = uwb_rc_mac_addr_set(rc, &addr);
    if (result == 0)
        rc->uwb_dev.mac_addr = addr;
out:
    return result < 0 ? result : size;
}
DEVICE_ATTR(mac_address, S_IRUGO | S_IWUSR, uwb_rc_mac_addr_show, uwb_rc_mac_addr_store);

size_t __uwb_addr_print(char *buf, size_t buf_size, const unsigned char *addr,
            int type)
{
    size_t result;
    if (type)
        result = scnprintf(buf, buf_size, "%pM", addr);
    else
        result = scnprintf(buf, buf_size, "%02x:%02x",
                  addr[1], addr[0]);
    return result;
}
EXPORT_SYMBOL_GPL(__uwb_addr_print);