fw.c

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/*
 * Atheros CARL9170 driver
 *
 * firmware parser
 *
 * Copyright 2009, 2010, Christian Lamparter <[email protected]>
 *
 * 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; see the file COPYING.  If not, see
 * http://www.gnu.org/licenses/.
 */

#include <linux/kernel.h>
#include <linux/firmware.h>
#include <linux/crc32.h>
#include <linux/module.h>
#include "carl9170.h"
#include "fwcmd.h"
#include "version.h"

#define MAKE_STR(symbol) #symbol
#define TO_STR(symbol) MAKE_STR(symbol)
#define CARL9170FW_API_VER_STR TO_STR(CARL9170FW_API_MAX_VER)
MODULE_VERSION(CARL9170FW_API_VER_STR ":" CARL9170FW_VERSION_GIT);

static const u8 otus_magic[4] = { OTUS_MAGIC };

static const void *carl9170_fw_find_desc(struct ar9170 *ar, const u8 descid[4],
    const unsigned int len, const u8 compatible_revision)
{
    const struct carl9170fw_desc_head *iter;

    carl9170fw_for_each_hdr(iter, ar->fw.desc) {
        if (carl9170fw_desc_cmp(iter, descid, len,
                    compatible_revision))
            return (void *)iter;
    }

    /* needed to find the LAST desc */
    if (carl9170fw_desc_cmp(iter, descid, len,
                compatible_revision))
        return (void *)iter;

    return NULL;
}

static int carl9170_fw_verify_descs(struct ar9170 *ar,
    const struct carl9170fw_desc_head *head, unsigned int max_len)
{
    const struct carl9170fw_desc_head *pos;
    unsigned long pos_addr, end_addr;
    unsigned int pos_length;

    if (max_len < sizeof(*pos))
        return -ENODATA;

    max_len = min_t(unsigned int, CARL9170FW_DESC_MAX_LENGTH, max_len);

    pos = head;
    pos_addr = (unsigned long) pos;
    end_addr = pos_addr + max_len;

    while (pos_addr < end_addr) {
        if (pos_addr + sizeof(*head) > end_addr)
            return -E2BIG;

        pos_length = le16_to_cpu(pos->length);

        if (pos_length < sizeof(*head))
            return -EBADMSG;

        if (pos_length > max_len)
            return -EOVERFLOW;

        if (pos_addr + pos_length > end_addr)
            return -EMSGSIZE;

        if (carl9170fw_desc_cmp(pos, LAST_MAGIC,
                    CARL9170FW_LAST_DESC_SIZE,
                    CARL9170FW_LAST_DESC_CUR_VER))
            return 0;

        pos_addr += pos_length;
        pos = (void *)pos_addr;
        max_len -= pos_length;
    }
    return -EINVAL;
}

static void carl9170_fw_info(struct ar9170 *ar)
{
    const struct carl9170fw_motd_desc *motd_desc;
    unsigned int str_ver_len;
    u32 fw_date;

    dev_info(&ar->udev->dev, "driver   API: %s 2%03d-%02d-%02d [%d-%d]\n",
        CARL9170FW_VERSION_GIT, CARL9170FW_VERSION_YEAR,
        CARL9170FW_VERSION_MONTH, CARL9170FW_VERSION_DAY,
        CARL9170FW_API_MIN_VER, CARL9170FW_API_MAX_VER);

    motd_desc = carl9170_fw_find_desc(ar, MOTD_MAGIC,
        sizeof(*motd_desc), CARL9170FW_MOTD_DESC_CUR_VER);

    if (motd_desc) {
        str_ver_len = strnlen(motd_desc->release,
            CARL9170FW_MOTD_RELEASE_LEN);

        fw_date = le32_to_cpu(motd_desc->fw_year_month_day);

        dev_info(&ar->udev->dev, "firmware API: %.*s 2%03d-%02d-%02d\n",
             str_ver_len, motd_desc->release,
             CARL9170FW_GET_YEAR(fw_date),
             CARL9170FW_GET_MONTH(fw_date),
             CARL9170FW_GET_DAY(fw_date));

        strlcpy(ar->hw->wiphy->fw_version, motd_desc->release,
            sizeof(ar->hw->wiphy->fw_version));
    }
}

static bool valid_dma_addr(const u32 address)
{
    if (address >= AR9170_SRAM_OFFSET &&
        address < (AR9170_SRAM_OFFSET + AR9170_SRAM_SIZE))
        return true;

    return false;
}

static bool valid_cpu_addr(const u32 address)
{
    if (valid_dma_addr(address) || (address >= AR9170_PRAM_OFFSET &&
        address < (AR9170_PRAM_OFFSET + AR9170_PRAM_SIZE)))
        return true;

    return false;
}

static int carl9170_fw_checksum(struct ar9170 *ar, const __u8 *data,
                size_t len)
{
    const struct carl9170fw_otus_desc *otus_desc;
    const struct carl9170fw_last_desc *last_desc;
    const struct carl9170fw_chk_desc *chk_desc;
    unsigned long fin, diff;
    unsigned int dsc_len;
    u32 crc32;

    last_desc = carl9170_fw_find_desc(ar, LAST_MAGIC,
        sizeof(*last_desc), CARL9170FW_LAST_DESC_CUR_VER);
    if (!last_desc)
        return -EINVAL;

    otus_desc = carl9170_fw_find_desc(ar, OTUS_MAGIC,
        sizeof(*otus_desc), CARL9170FW_OTUS_DESC_CUR_VER);
    if (!otus_desc) {
        dev_err(&ar->udev->dev, "failed to find compatible firmware "
            "descriptor.\n");
        return -ENODATA;
    }

    chk_desc = carl9170_fw_find_desc(ar, CHK_MAGIC,
        sizeof(*chk_desc), CARL9170FW_CHK_DESC_CUR_VER);

    if (!chk_desc) {
        dev_warn(&ar->udev->dev, "Unprotected firmware image.\n");
        return 0;
    }

    dsc_len = min_t(unsigned int, len,
            (unsigned long)chk_desc - (unsigned long)otus_desc);

    fin = (unsigned long) last_desc + sizeof(*last_desc);
    diff = fin - (unsigned long) otus_desc;

    if (diff < len)
        len -= diff;

    if (len < 256)
        return -EIO;

    crc32 = crc32_le(~0, data, len);
    if (cpu_to_le32(crc32) != chk_desc->fw_crc32) {
        dev_err(&ar->udev->dev, "fw checksum test failed.\n");
        return -ENOEXEC;
    }

    crc32 = crc32_le(crc32, (void *)otus_desc, dsc_len);
    if (cpu_to_le32(crc32) != chk_desc->hdr_crc32) {
        dev_err(&ar->udev->dev, "descriptor check failed.\n");
        return -EINVAL;
    }
    return 0;
}

static int carl9170_fw_tx_sequence(struct ar9170 *ar)
{
    const struct carl9170fw_txsq_desc *txsq_desc;

    txsq_desc = carl9170_fw_find_desc(ar, TXSQ_MAGIC, sizeof(*txsq_desc),
                      CARL9170FW_TXSQ_DESC_CUR_VER);
    if (txsq_desc) {
        ar->fw.tx_seq_table = le32_to_cpu(txsq_desc->seq_table_addr);
        if (!valid_cpu_addr(ar->fw.tx_seq_table))
            return -EINVAL;
    } else {
        ar->fw.tx_seq_table = 0;
    }

    return 0;
}

static int carl9170_fw(struct ar9170 *ar, const __u8 *data, size_t len)
{
    const struct carl9170fw_otus_desc *otus_desc;
    int err;
    u16 if_comb_types;

    err = carl9170_fw_checksum(ar, data, len);
    if (err)
        return err;

    otus_desc = carl9170_fw_find_desc(ar, OTUS_MAGIC,
        sizeof(*otus_desc), CARL9170FW_OTUS_DESC_CUR_VER);
    if (!otus_desc) {
        return -ENODATA;
    }

#define SUPP(feat)                      \
    (carl9170fw_supports(otus_desc->feature_set, feat))

    if (!SUPP(CARL9170FW_DUMMY_FEATURE)) {
        dev_err(&ar->udev->dev, "invalid firmware descriptor "
            "format detected.\n");
        return -EINVAL;
    }

    ar->fw.api_version = otus_desc->api_ver;

    if (ar->fw.api_version < CARL9170FW_API_MIN_VER ||
        ar->fw.api_version > CARL9170FW_API_MAX_VER) {
        dev_err(&ar->udev->dev, "unsupported firmware api version.\n");
        return -EINVAL;
    }

    if (!SUPP(CARL9170FW_COMMAND_PHY) || SUPP(CARL9170FW_UNUSABLE) ||
        !SUPP(CARL9170FW_HANDLE_BACK_REQ)) {
        dev_err(&ar->udev->dev, "firmware does support "
            "mandatory features.\n");
        return -ECANCELED;
    }

    if (ilog2(le32_to_cpu(otus_desc->feature_set)) >=
        __CARL9170FW_FEATURE_NUM) {
        dev_warn(&ar->udev->dev, "driver does not support all "
             "firmware features.\n");
    }

    if (!SUPP(CARL9170FW_COMMAND_CAM)) {
        dev_info(&ar->udev->dev, "crypto offloading is disabled "
             "by firmware.\n");
        ar->disable_offload = true;
    }

    if (SUPP(CARL9170FW_PSM) && SUPP(CARL9170FW_FIXED_5GHZ_PSM))
        ar->hw->flags |= IEEE80211_HW_SUPPORTS_PS;

    if (!SUPP(CARL9170FW_USB_INIT_FIRMWARE)) {
        dev_err(&ar->udev->dev, "firmware does not provide "
            "mandatory interfaces.\n");
        return -EINVAL;
    }

    if (SUPP(CARL9170FW_MINIBOOT))
        ar->fw.offset = le16_to_cpu(otus_desc->miniboot_size);
    else
        ar->fw.offset = 0;

    if (SUPP(CARL9170FW_USB_DOWN_STREAM)) {
        ar->hw->extra_tx_headroom += sizeof(struct ar9170_stream);
        ar->fw.tx_stream = true;
    }

    if (SUPP(CARL9170FW_USB_UP_STREAM))
        ar->fw.rx_stream = true;

    if (SUPP(CARL9170FW_RX_FILTER)) {
        ar->fw.rx_filter = true;
        ar->rx_filter_caps = FIF_FCSFAIL | FIF_PLCPFAIL |
            FIF_CONTROL | FIF_PSPOLL | FIF_OTHER_BSS |
            FIF_PROMISC_IN_BSS;
    }

    if (SUPP(CARL9170FW_HW_COUNTERS))
        ar->fw.hw_counters = true;

    if (SUPP(CARL9170FW_WOL))
        device_set_wakeup_enable(&ar->udev->dev, true);

    if (SUPP(CARL9170FW_RX_BA_FILTER))
        ar->fw.ba_filter = true;

    if_comb_types = BIT(NL80211_IFTYPE_STATION) |
            BIT(NL80211_IFTYPE_P2P_CLIENT);

    ar->fw.vif_num = otus_desc->vif_num;
    ar->fw.cmd_bufs = otus_desc->cmd_bufs;
    ar->fw.address = le32_to_cpu(otus_desc->fw_address);
    ar->fw.rx_size = le16_to_cpu(otus_desc->rx_max_frame_len);
    ar->fw.mem_blocks = min_t(unsigned int, otus_desc->tx_descs, 0xfe);
    atomic_set(&ar->mem_free_blocks, ar->fw.mem_blocks);
    ar->fw.mem_block_size = le16_to_cpu(otus_desc->tx_frag_len);

    if (ar->fw.vif_num >= AR9170_MAX_VIRTUAL_MAC || !ar->fw.vif_num ||
        ar->fw.mem_blocks < 16 || !ar->fw.cmd_bufs ||
        ar->fw.mem_block_size < 64 || ar->fw.mem_block_size > 512 ||
        ar->fw.rx_size > 32768 || ar->fw.rx_size < 4096 ||
        !valid_cpu_addr(ar->fw.address)) {
        dev_err(&ar->udev->dev, "firmware shows obvious signs of "
            "malicious tampering.\n");
        return -EINVAL;
    }

    ar->fw.beacon_addr = le32_to_cpu(otus_desc->bcn_addr);
    ar->fw.beacon_max_len = le16_to_cpu(otus_desc->bcn_len);

    if (valid_dma_addr(ar->fw.beacon_addr) && ar->fw.beacon_max_len >=
        AR9170_MAC_BCN_LENGTH_MAX) {
        ar->hw->wiphy->interface_modes |= BIT(NL80211_IFTYPE_ADHOC);

        if (SUPP(CARL9170FW_WLANTX_CAB)) {
            if_comb_types |=
                BIT(NL80211_IFTYPE_AP) |
                BIT(NL80211_IFTYPE_MESH_POINT) |
                BIT(NL80211_IFTYPE_P2P_GO);
        }
    }

    ar->if_comb_limits[0].max = ar->fw.vif_num;
    ar->if_comb_limits[0].types = if_comb_types;

    ar->if_combs[0].num_different_channels = 1;
    ar->if_combs[0].max_interfaces = ar->fw.vif_num;
    ar->if_combs[0].limits = ar->if_comb_limits;
    ar->if_combs[0].n_limits = ARRAY_SIZE(ar->if_comb_limits);

    ar->hw->wiphy->iface_combinations = ar->if_combs;
    ar->hw->wiphy->n_iface_combinations = ARRAY_SIZE(ar->if_combs);

    ar->hw->wiphy->interface_modes |= if_comb_types;

    ar->hw->wiphy->flags |= WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;

#undef SUPPORTED
    return carl9170_fw_tx_sequence(ar);
}

static struct carl9170fw_desc_head *
carl9170_find_fw_desc(struct ar9170 *ar, const __u8 *fw_data, const size_t len)

{
    int scan = 0, found = 0;

    if (!carl9170fw_size_check(len)) {
        dev_err(&ar->udev->dev, "firmware size is out of bound.\n");
        return NULL;
    }

    while (scan < len - sizeof(struct carl9170fw_desc_head)) {
        if (fw_data[scan++] == otus_magic[found])
            found++;
        else
            found = 0;

        if (scan >= len)
            break;

        if (found == sizeof(otus_magic))
            break;
    }

    if (found != sizeof(otus_magic))
        return NULL;

    return (void *)&fw_data[scan - found];
}

int carl9170_parse_firmware(struct ar9170 *ar)
{
    const struct carl9170fw_desc_head *fw_desc = NULL;
    const struct firmware *fw = ar->fw.fw;
    unsigned long header_offset = 0;
    int err;

    if (WARN_ON(!fw))
        return -EINVAL;

    fw_desc = carl9170_find_fw_desc(ar, fw->data, fw->size);

    if (!fw_desc) {
        dev_err(&ar->udev->dev, "unsupported firmware.\n");
        return -ENODATA;
    }

    header_offset = (unsigned long)fw_desc - (unsigned long)fw->data;

    err = carl9170_fw_verify_descs(ar, fw_desc, fw->size - header_offset);
    if (err) {
        dev_err(&ar->udev->dev, "damaged firmware (%d).\n", err);
        return err;
    }

    ar->fw.desc = fw_desc;

    carl9170_fw_info(ar);

    err = carl9170_fw(ar, fw->data, fw->size);
    if (err) {
        dev_err(&ar->udev->dev, "failed to parse firmware (%d).\n",
            err);
        return err;
    }

    return 0;
}