netdev_settings.c

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/*
 * Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * 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 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; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * You can also choose to distribute this program under the terms of
 * the Unmodified Binary Distribution Licence (as given in the file
 * COPYING.UBDL), provided that you have satisfied its requirements.
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <string.h>
#include <errno.h>
#include <byteswap.h>
#include <ipxe/dhcp.h>
#include <ipxe/dhcpopts.h>
#include <ipxe/settings.h>
#include <ipxe/device.h>
#include <ipxe/netdevice.h>
#include <ipxe/init.h>

/** @file
 *
 * Network device configuration settings
 *
 */

/** Network device predefined settings */
const struct setting mac_setting __setting ( SETTING_NETDEV, mac ) = {
        .name = "mac",
        .description = "MAC address",
        .type = &setting_type_hex,
};
const struct setting hwaddr_setting __setting ( SETTING_NETDEV, hwaddr ) = {
        .name = "hwaddr",
        .description = "Hardware address",
        .type = &setting_type_hex,
};
const struct setting bustype_setting __setting ( SETTING_NETDEV, bustype ) = {
        .name = "bustype",
        .description = "Bus type",
        .type = &setting_type_string,
};
const struct setting busloc_setting __setting ( SETTING_NETDEV, busloc ) = {
        .name = "busloc",
        .description = "Bus location",
        .type = &setting_type_uint32,
};
const struct setting busid_setting __setting ( SETTING_NETDEV, busid ) = {
        .name = "busid",
        .description = "Bus ID",
        .type = &setting_type_hex,
};
const struct setting linktype_setting __setting ( SETTING_NETDEV, linktype ) = {
        .name = "linktype",
        .description = "Link-layer type",
        .type = &setting_type_string,
};
const struct setting chip_setting __setting ( SETTING_NETDEV, chip ) = {
        .name = "chip",
        .description = "Chip",
        .type = &setting_type_string,
};
const struct setting ifname_setting __setting ( SETTING_NETDEV, ifname ) = {
        .name = "ifname",
        .description = "Interface name",
        .type = &setting_type_string,
};
const struct setting mtu_setting __setting ( SETTING_NETDEV, mtu ) = {
        .name = "mtu",
        .description = "MTU",
        .type = &setting_type_int16,
        .tag = DHCP_MTU,
};

/**
 * Store link-layer address setting
 *
 * @v netdev            Network device
 * @v data              Setting data, or NULL to clear setting
 * @v len               Length of setting data
 * @ret rc              Return status code
 */
static int netdev_store_mac ( struct net_device *netdev,
                              const void *data, size_t len ) {
        struct ll_protocol *ll_protocol = netdev->ll_protocol;

        /* Record new MAC address */
        if ( data ) {
                if ( len != netdev->ll_protocol->ll_addr_len )
                        return -EINVAL;
                memcpy ( netdev->ll_addr, data, len );
        } else {
                /* Reset MAC address if clearing setting */
                ll_protocol->init_addr ( netdev->hw_addr, netdev->ll_addr );
        }

        return 0;
}

/**
 * Fetch link-layer address setting
 *
 * @v netdev            Network device
 * @v data              Buffer to fill with setting data
 * @v len               Length of buffer
 * @ret len             Length of setting data, or negative error
 */
static int netdev_fetch_mac ( struct net_device *netdev, void *data,
                              size_t len ) {
        size_t max_len = netdev->ll_protocol->ll_addr_len;

        if ( len > max_len )
                len = max_len;
        memcpy ( data, netdev->ll_addr, len );
        return max_len;
}

/**
 * Fetch hardware address setting
 *
 * @v netdev            Network device
 * @v data              Buffer to fill with setting data
 * @v len               Length of buffer
 * @ret len             Length of setting data, or negative error
 */
static int netdev_fetch_hwaddr ( struct net_device *netdev, void *data,
                                 size_t len ) {
        size_t max_len = netdev->ll_protocol->hw_addr_len;

        if ( len > max_len )
                len = max_len;
        memcpy ( data, netdev->hw_addr, len );
        return max_len;
}

/**
 * Fetch bus type setting
 *
 * @v netdev            Network device
 * @v data              Buffer to fill with setting data
 * @v len               Length of buffer
 * @ret len             Length of setting data, or negative error
 */
static int netdev_fetch_bustype ( struct net_device *netdev, void *data,
                                  size_t len ) {
        static const char *bustypes[] = {
                [BUS_TYPE_PCI] = "PCI",
                [BUS_TYPE_ISAPNP] = "ISAPNP",
                [BUS_TYPE_EISA] = "EISA",
                [BUS_TYPE_MCA] = "MCA",
                [BUS_TYPE_ISA] = "ISA",
                [BUS_TYPE_TAP] = "TAP",
                [BUS_TYPE_EFI] = "EFI",
                [BUS_TYPE_XEN] = "XEN",
                [BUS_TYPE_HV] = "HV",
                [BUS_TYPE_USB] = "USB",
        };
        struct device_description *desc = &netdev->dev->desc;
        const char *bustype;

        assert ( desc->bus_type < ( sizeof ( bustypes ) /
                                    sizeof ( bustypes[0] ) ) );
        bustype = bustypes[desc->bus_type];
        if ( ! bustype )
                return -ENOENT;
        strncpy ( data, bustype, len );
        return strlen ( bustype );
}

/**
 * Fetch bus location setting
 *
 * @v netdev            Network device
 * @v data              Buffer to fill with setting data
 * @v len               Length of buffer
 * @ret len             Length of setting data, or negative error
 */
static int netdev_fetch_busloc ( struct net_device *netdev, void *data,
                                 size_t len ) {
        struct device_description *desc = &netdev->dev->desc;
        uint32_t busloc;

        busloc = cpu_to_be32 ( desc->location );
        if ( len > sizeof ( busloc ) )
                len = sizeof ( busloc );
        memcpy ( data, &busloc, len );
        return sizeof ( busloc );
}

/**
 * Fetch bus ID setting
 *
 * @v netdev            Network device
 * @v data              Buffer to fill with setting data
 * @v len               Length of buffer
 * @ret len             Length of setting data, or negative error
 */
static int netdev_fetch_busid ( struct net_device *netdev, void *data,
                                size_t len ) {
        struct device_description *desc = &netdev->dev->desc;
        struct dhcp_netdev_desc dhcp_desc;

        dhcp_desc.type = desc->bus_type;
        dhcp_desc.vendor = htons ( desc->vendor );
        dhcp_desc.device = htons ( desc->device );
        if ( len > sizeof ( dhcp_desc ) )
                len = sizeof ( dhcp_desc );
        memcpy ( data, &dhcp_desc, len );
        return sizeof ( dhcp_desc );
}

/**
 * Fetch link layer type setting
 *
 * @v netdev            Network device
 * @v data              Buffer to fill with setting data
 * @v len               Length of buffer
 * @ret len             Length of setting data, or negative error
 */
static int netdev_fetch_linktype ( struct net_device *netdev, void *data,
                                   size_t len ) {
        const char *linktype = netdev->ll_protocol->name;

        strncpy ( data, linktype, len );
        return strlen ( linktype );
}

/**
 * Fetch chip setting
 *
 * @v netdev            Network device
 * @v data              Buffer to fill with setting data
 * @v len               Length of buffer
 * @ret len             Length of setting data, or negative error
 */
static int netdev_fetch_chip ( struct net_device *netdev, void *data,
                               size_t len ) {
        const char *chip = netdev->dev->driver_name;

        strncpy ( data, chip, len );
        return strlen ( chip );
}

/**
 * Fetch ifname setting
 *
 * @v netdev            Network device
 * @v data              Buffer to fill with setting data
 * @v len               Length of buffer
 * @ret len             Length of setting data, or negative error
 */
static int netdev_fetch_ifname ( struct net_device *netdev, void *data,
                                 size_t len ) {
        const char *ifname = netdev->name;

        strncpy ( data, ifname, len );
        return strlen ( ifname );
}

/** A network device setting operation */
struct netdev_setting_operation {
        /** Setting */
        const struct setting *setting;
        /** Store setting (or NULL if not supported)
         *
         * @v netdev            Network device
         * @v data              Setting data, or NULL to clear setting
         * @v len               Length of setting data
         * @ret rc              Return status code
         */
        int ( * store ) ( struct net_device *netdev, const void *data,
                          size_t len );
        /** Fetch setting
         *
         * @v netdev            Network device
         * @v data              Buffer to fill with setting data
         * @v len               Length of buffer
         * @ret len             Length of setting data, or negative error
         */
        int ( * fetch ) ( struct net_device *netdev, void *data, size_t len );
};

/** Network device settings */
static struct netdev_setting_operation netdev_setting_operations[] = {
        { &mac_setting, netdev_store_mac, netdev_fetch_mac },
        { &hwaddr_setting, NULL, netdev_fetch_hwaddr },
        { &bustype_setting, NULL, netdev_fetch_bustype },
        { &busloc_setting, NULL, netdev_fetch_busloc },
        { &busid_setting, NULL, netdev_fetch_busid },
        { &linktype_setting, NULL, netdev_fetch_linktype },
        { &chip_setting, NULL, netdev_fetch_chip },
        { &ifname_setting, NULL, netdev_fetch_ifname },
};

/**
 * Store value of network device setting
 *
 * @v settings          Settings block
 * @v setting           Setting to store
 * @v data              Setting data, or NULL to clear setting
 * @v len               Length of setting data
 * @ret rc              Return status code
 */
static int netdev_store ( struct settings *settings,
                          const struct setting *setting,
                          const void *data, size_t len ) {
        struct net_device *netdev = container_of ( settings, struct net_device,
                                                   settings.settings );
        struct netdev_setting_operation *op;
        unsigned int i;

        /* Handle network device-specific settings */
        for ( i = 0 ; i < ( sizeof ( netdev_setting_operations ) /
                            sizeof ( netdev_setting_operations[0] ) ) ; i++ ) {
                op = &netdev_setting_operations[i];
                if ( setting_cmp ( setting, op->setting ) == 0 ) {
                        if ( op->store ) {
                                return op->store ( netdev, data, len );
                        } else {
                                return -ENOTSUP;
                        }
                }
        }

        return generic_settings_store ( settings, setting, data, len );
}

/**
 * Fetch value of network device setting
 *
 * @v settings          Settings block
 * @v setting           Setting to fetch
 * @v data              Buffer to fill with setting data
 * @v len               Length of buffer
 * @ret len             Length of setting data, or negative error
 */
static int netdev_fetch ( struct settings *settings, struct setting *setting,
                          void *data, size_t len ) {
        struct net_device *netdev = container_of ( settings, struct net_device,
                                                   settings.settings );
        struct netdev_setting_operation *op;
        unsigned int i;

        /* Handle network device-specific settings */
        for ( i = 0 ; i < ( sizeof ( netdev_setting_operations ) /
                            sizeof ( netdev_setting_operations[0] ) ) ; i++ ) {
                op = &netdev_setting_operations[i];
                if ( setting_cmp ( setting, op->setting ) == 0 )
                        return op->fetch ( netdev, data, len );
        }

        return generic_settings_fetch ( settings, setting, data, len );
}

/**
 * Clear network device settings
 *
 * @v settings          Settings block
 */
static void netdev_clear ( struct settings *settings ) {
        generic_settings_clear ( settings );
}

/** Network device configuration settings operations */
struct settings_operations netdev_settings_operations = {
        .store = netdev_store,
        .fetch = netdev_fetch,
        .clear = netdev_clear,
};

/**
 * Redirect "netX" settings block
 *
 * @v settings          Settings block
 * @ret settings        Underlying settings block
 */
static struct settings * netdev_redirect ( struct settings *settings ) {
        struct net_device *netdev;

        /* Redirect to "netX" network device */
        netdev = find_netdev ( settings->name );
        if ( netdev ) {
                return netdev_settings ( netdev );
        } else {
                return settings;
        }
}

/** "netX" settings operations */
static struct settings_operations netdev_redirect_settings_operations = {
        .redirect = netdev_redirect,
};

/** "netX" settings */
static struct settings netdev_redirect_settings = {
        .refcnt = NULL,
        .siblings = LIST_HEAD_INIT ( netdev_redirect_settings.siblings ),
        .children = LIST_HEAD_INIT ( netdev_redirect_settings.children ),
        .op = &netdev_redirect_settings_operations,
};

/** Initialise "netX" settings */
static void netdev_redirect_settings_init ( void ) {
        int rc;

        if ( ( rc = register_settings ( &netdev_redirect_settings, NULL,
                                        "netX" ) ) != 0 ) {
                DBG ( "Could not register netX settings: %s\n",
                      strerror ( rc ) );
                return;
        }
}

/** "netX" settings initialiser */
struct init_fn netdev_redirect_settings_init_fn __init_fn ( INIT_LATE ) = {
        .initialise = netdev_redirect_settings_init,
};

/**
 * Apply network device settings
 *
 * @ret rc              Return status code
 */
static int apply_netdev_settings ( void ) {
        struct net_device *netdev;
        struct settings *settings;
        struct ll_protocol *ll_protocol;
        size_t max_mtu;
        size_t old_mtu;
        size_t mtu;
        int rc;

        /* Process settings for each network device */
        for_each_netdev ( netdev ) {

                /* Get network device settings */
                settings = netdev_settings ( netdev );

                /* Get MTU */
                mtu = fetch_uintz_setting ( settings, &mtu_setting );

                /* Do nothing unless MTU is specified */
                if ( ! mtu )
                        continue;

                /* Limit MTU to maximum supported by hardware */
                ll_protocol = netdev->ll_protocol;
                max_mtu = ( netdev->max_pkt_len - ll_protocol->ll_header_len );
                if ( mtu > max_mtu ) {
                        DBGC ( netdev, "NETDEV %s cannot support MTU %zd (max "
                               "%zd)\n", netdev->name, mtu, max_mtu );
                        mtu = max_mtu;
                }

                /* Update maximum packet length */
                old_mtu = netdev->mtu;
                netdev->mtu = mtu;
                if ( mtu != old_mtu ) {
                        DBGC ( netdev, "NETDEV %s MTU is %zd\n",
                               netdev->name, mtu );
                }

                /* Close and reopen network device if MTU has increased */
                if ( netdev_is_open ( netdev ) && ( mtu > old_mtu ) ) {
                        netdev_close ( netdev );
                        if ( ( rc = netdev_open ( netdev ) ) != 0 ) {
                                DBGC ( netdev, "NETDEV %s could not reopen: "
                                       "%s\n", netdev->name, strerror ( rc ) );
                                return rc;
                        }
                }
        }

        return 0;
}

/** Network device settings applicator */
struct settings_applicator netdev_applicator __settings_applicator = {
        .apply = apply_netdev_settings,
};