/*

 * Copyright (c) 2017 Red Hat, Inc.

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at:

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include <config.h>

#include "dpif-netlink-rtnl.h"

#include <net/if.h>

#include <linux/ip.h>

#include <linux/rtnetlink.h>

#include "dpif-netlink.h"

#include "netdev-vport.h"

#include "netlink-socket.h"

#include "openvswitch/vlog.h"

VLOG_DEFINE_THIS_MODULE(dpif_netlink_rtnl);

/* On some older systems, these enums are not defined. */

#ifndef IFLA_VXLAN_MAX

#define IFLA_VXLAN_MAX 0

#endif

#if IFLA_VXLAN_MAX < 27

#define IFLA_VXLAN_LEARNING 7

#define IFLA_VXLAN_PORT 15

#define IFLA_VXLAN_UDP_ZERO_CSUM6_RX 20

#define IFLA_VXLAN_GBP 23

#define IFLA_VXLAN_COLLECT_METADATA 25

#define IFLA_VXLAN_GPE 27

#endif

#ifndef IFLA_GRE_MAX

#define IFLA_GRE_MAX 0

#endif

#if IFLA_GRE_MAX < 18

#define IFLA_GRE_COLLECT_METADATA 18

#endif

#ifndef IFLA_GENEVE_MAX

#define IFLA_GENEVE_MAX 0

#endif

#if IFLA_GENEVE_MAX < 10

#define IFLA_GENEVE_PORT 5

#define IFLA_GENEVE_COLLECT_METADATA 6

#define IFLA_GENEVE_UDP_ZERO_CSUM6_RX 10

#endif

#ifndef IFLA_BAREUDP_MAX

#define IFLA_BAREUDP_MAX 0

#endif

#if IFLA_BAREUDP_MAX < 4

#define IFLA_BAREUDP_PORT 1

#define IFLA_BAREUDP_ETHERTYPE 2

#define IFLA_BAREUDP_SRCPORT_MIN 3

#define IFLA_BAREUDP_MULTIPROTO_MODE 4

#endif

#define BAREUDP_SRCPORT_MIN 49153

static const struct nl_policy rtlink_policy[] = {

    [IFLA_LINKINFO] = { .type = NL_A_NESTED },

};

static const struct nl_policy linkinfo_policy[] = {

    [IFLA_INFO_KIND] = { .type = NL_A_STRING },

    [IFLA_INFO_DATA] = { .type = NL_A_NESTED },

};

static const struct nl_policy vxlan_policy[] = {

    [IFLA_VXLAN_COLLECT_METADATA] = { .type = NL_A_U8 },

    [IFLA_VXLAN_LEARNING] = { .type = NL_A_U8 },

    [IFLA_VXLAN_UDP_ZERO_CSUM6_RX] = { .type = NL_A_U8 },

    [IFLA_VXLAN_PORT] = { .type = NL_A_U16 },

    [IFLA_VXLAN_GBP] = { .type = NL_A_FLAG, .optional = true },

    [IFLA_VXLAN_GPE] = { .type = NL_A_FLAG, .optional = true },

};

static const struct nl_policy gre_policy[] = {

    [IFLA_GRE_COLLECT_METADATA] = { .type = NL_A_FLAG },

};

static const struct nl_policy geneve_policy[] = {

    [IFLA_GENEVE_COLLECT_METADATA] = { .type = NL_A_FLAG },

    [IFLA_GENEVE_UDP_ZERO_CSUM6_RX] = { .type = NL_A_U8 },

    [IFLA_GENEVE_PORT] = { .type = NL_A_U16 },

};

static const struct nl_policy bareudp_policy[] = {

    [IFLA_BAREUDP_PORT] = { .type = NL_A_U16 },

    [IFLA_BAREUDP_ETHERTYPE] = { .type = NL_A_U16 },

};

static const char *

vport_type_to_kind(enum ovs_vport_type type,

                   const struct netdev_tunnel_config *tnl_cfg)

{

    switch (type) {

    case OVS_VPORT_TYPE_VXLAN:

        return "vxlan";

    case OVS_VPORT_TYPE_GRE:

        if (tnl_cfg->pt_mode == NETDEV_PT_LEGACY_L3) {

            return "gre";

        } else if (tnl_cfg->pt_mode == NETDEV_PT_LEGACY_L2) {

            return "gretap";

        } else {

            return NULL;

        }

    case OVS_VPORT_TYPE_GENEVE:

        return "geneve";

    case OVS_VPORT_TYPE_ERSPAN:

        return "erspan";

    case OVS_VPORT_TYPE_IP6ERSPAN:

        return "ip6erspan";

    case OVS_VPORT_TYPE_IP6GRE:

        if (tnl_cfg->pt_mode == NETDEV_PT_LEGACY_L2) {

            return "ip6gretap";

        } else if (tnl_cfg->pt_mode == NETDEV_PT_LEGACY_L3) {

            return NULL;

        } else {

            return NULL;

        }

    case OVS_VPORT_TYPE_GTPU:

        return NULL;

    case OVS_VPORT_TYPE_SRV6:

        return "srv6";

    case OVS_VPORT_TYPE_BAREUDP:

        return "bareudp";

    case OVS_VPORT_TYPE_NETDEV:

    case OVS_VPORT_TYPE_INTERNAL:

    case OVS_VPORT_TYPE_UNSPEC:

    case __OVS_VPORT_TYPE_MAX:

    default:

        break;

    }

    return NULL;

}

static int

rtnl_transact(uint32_t type, uint32_t flags, const char *name,

              struct ofpbuf **reply)

{

    struct ofpbuf request;

    int err;

    ofpbuf_init(&request, 0);

    nl_msg_put_nlmsghdr(&request, 0, type, flags);

    ofpbuf_put_zeros(&request, sizeof(struct ifinfomsg));

    nl_msg_put_string(&request, IFLA_IFNAME, name);

    err = nl_transact(NETLINK_ROUTE, &request, reply);

    ofpbuf_uninit(&request);

    return err;

}

static int

dpif_netlink_rtnl_destroy(const char *name)

{

    return rtnl_transact(RTM_DELLINK, NLM_F_REQUEST | NLM_F_ACK, name, NULL);

}

static int

dpif_netlink_rtnl_getlink(const char *name, struct ofpbuf **reply)

{

    return rtnl_transact(RTM_GETLINK, NLM_F_REQUEST, name, reply);

}

static int

rtnl_policy_parse(const char *kind, struct ofpbuf *reply,

                  const struct nl_policy *policy,

                  struct nlattr *tnl_info[],

                  size_t policy_size)

{

    struct nlattr *linkinfo[ARRAY_SIZE(linkinfo_policy)];

    struct nlattr *rtlink[ARRAY_SIZE(rtlink_policy)];

    int error = 0;

    if (!nl_policy_parse(reply, NLMSG_HDRLEN + sizeof(struct ifinfomsg),

                         rtlink_policy, rtlink, ARRAY_SIZE(rtlink_policy))

        || !nl_parse_nested(rtlink[IFLA_LINKINFO], linkinfo_policy,

                            linkinfo, ARRAY_SIZE(linkinfo_policy))

        || strcmp(nl_attr_get_string(linkinfo[IFLA_INFO_KIND]), kind)

        || !nl_parse_nested(linkinfo[IFLA_INFO_DATA], policy,

                            tnl_info, policy_size)) {

        error = EINVAL;

    }

    return error;

}

static int

dpif_netlink_rtnl_vxlan_verify(const struct netdev_tunnel_config *tnl_cfg,

                               const char *kind, struct ofpbuf *reply)

{

    struct nlattr *vxlan[ARRAY_SIZE(vxlan_policy)];

    int err;

    err = rtnl_policy_parse(kind, reply, vxlan_policy, vxlan,

                            ARRAY_SIZE(vxlan_policy));

    if (!err) {

        if (0 != nl_attr_get_u8(vxlan[IFLA_VXLAN_LEARNING])

            || 1 != nl_attr_get_u8(vxlan[IFLA_VXLAN_COLLECT_METADATA])

            || 1 != nl_attr_get_u8(vxlan[IFLA_VXLAN_UDP_ZERO_CSUM6_RX])

            || (tnl_cfg->dst_port

                != nl_attr_get_be16(vxlan[IFLA_VXLAN_PORT]))

            || (tnl_cfg->exts & (1 << OVS_VXLAN_EXT_GBP)

                && !nl_attr_get_flag(vxlan[IFLA_VXLAN_GBP]))

            || (tnl_cfg->exts & (1 << OVS_VXLAN_EXT_GPE)

                && !nl_attr_get_flag(vxlan[IFLA_VXLAN_GPE]))) {

            err = EINVAL;

        }

    }

    return err;

}

static int

dpif_netlink_rtnl_gre_verify(const struct netdev_tunnel_config OVS_UNUSED *tnl,

                             const char *kind, struct ofpbuf *reply)

{

    struct nlattr *gre[ARRAY_SIZE(gre_policy)];

    int err;

    err = rtnl_policy_parse(kind, reply, gre_policy, gre,

                            ARRAY_SIZE(gre_policy));

    if (!err) {

        if (!nl_attr_get_flag(gre[IFLA_GRE_COLLECT_METADATA])) {

            err = EINVAL;

        }

    }

    return err;

}

static int

dpif_netlink_rtnl_geneve_verify(const struct netdev_tunnel_config *tnl_cfg,

                                const char *kind, struct ofpbuf *reply)

{

    struct nlattr *geneve[ARRAY_SIZE(geneve_policy)];

    int err;

    err = rtnl_policy_parse(kind, reply, geneve_policy, geneve,

                            ARRAY_SIZE(geneve_policy));

    if (!err) {

        if (!nl_attr_get_flag(geneve[IFLA_GENEVE_COLLECT_METADATA])

            || 1 != nl_attr_get_u8(geneve[IFLA_GENEVE_UDP_ZERO_CSUM6_RX])

            || (tnl_cfg->dst_port

                != nl_attr_get_be16(geneve[IFLA_GENEVE_PORT]))) {

            err = EINVAL;

        }

    }

    return err;

}

static int

dpif_netlink_rtnl_bareudp_verify(const struct netdev_tunnel_config *tnl_cfg,

                                const char *kind, struct ofpbuf *reply)

{

    struct nlattr *bareudp[ARRAY_SIZE(bareudp_policy)];

    int err;

    err = rtnl_policy_parse(kind, reply, bareudp_policy, bareudp,

                            ARRAY_SIZE(bareudp_policy));

    if (!err) {

        if ((tnl_cfg->dst_port != nl_attr_get_be16(bareudp[IFLA_BAREUDP_PORT]))

            || (tnl_cfg->payload_ethertype

                != nl_attr_get_be16(bareudp[IFLA_BAREUDP_ETHERTYPE]))) {

            err = EINVAL;

        }

    }

    return err;

}

static int

dpif_netlink_rtnl_verify(const struct netdev_tunnel_config *tnl_cfg,

                         enum ovs_vport_type type, const char *name)

{

    struct ofpbuf *reply;

    const char *kind;

    int err;

    kind = vport_type_to_kind(type, tnl_cfg);

    if (!kind) {

        return EOPNOTSUPP;

    }

    err = dpif_netlink_rtnl_getlink(name, &reply);

    if (err) {

        return err;

    }

    switch (type) {

    case OVS_VPORT_TYPE_VXLAN:

        err = dpif_netlink_rtnl_vxlan_verify(tnl_cfg, kind, reply);

        break;

    case OVS_VPORT_TYPE_GRE:

    case OVS_VPORT_TYPE_ERSPAN:

    case OVS_VPORT_TYPE_IP6ERSPAN:

    case OVS_VPORT_TYPE_IP6GRE:

        err = dpif_netlink_rtnl_gre_verify(tnl_cfg, kind, reply);

        break;

    case OVS_VPORT_TYPE_GENEVE:

        err = dpif_netlink_rtnl_geneve_verify(tnl_cfg, kind, reply);

        break;

    case OVS_VPORT_TYPE_BAREUDP:

        err = dpif_netlink_rtnl_bareudp_verify(tnl_cfg, kind, reply);

        break;

    case OVS_VPORT_TYPE_NETDEV:

    case OVS_VPORT_TYPE_INTERNAL:

    case OVS_VPORT_TYPE_GTPU:

    case OVS_VPORT_TYPE_SRV6:

    case OVS_VPORT_TYPE_UNSPEC:

    case __OVS_VPORT_TYPE_MAX:

    default:

        OVS_NOT_REACHED();

    }

    ofpbuf_delete(reply);

    return err;

}

static int

rtnl_set_mtu(const char *name, uint32_t mtu, struct ofpbuf *request)

{

    ofpbuf_clear(request);

    nl_msg_put_nlmsghdr(request, 0, RTM_SETLINK,

                        NLM_F_REQUEST | NLM_F_ACK);

    ofpbuf_put_zeros(request, sizeof(struct ifinfomsg));

    nl_msg_put_string(request, IFLA_IFNAME, name);

    nl_msg_put_u32(request, IFLA_MTU, mtu);

    return nl_transact(NETLINK_ROUTE, request, NULL);

}

static int

dpif_netlink_rtnl_create(const struct netdev_tunnel_config *tnl_cfg,

                         const char *name, enum ovs_vport_type type,

                         const char *kind, uint32_t flags)

{

    enum {

        /* For performance, we want to use the largest MTU that the system

         * supports.  Most existing tunnels will accept UINT16_MAX, treating it

         * as the actual max MTU, but some do not.  Thus, we use a slightly

         * smaller value, that should always be safe yet does not noticeably

         * reduce performance. */

        MAX_MTU = 65000

    };

    size_t linkinfo_off, infodata_off;

    struct ifinfomsg *ifinfo;

    struct ofpbuf request;

    int err;

    ofpbuf_init(&request, 0);

    nl_msg_put_nlmsghdr(&request, 0, RTM_NEWLINK, flags);

    ifinfo = ofpbuf_put_zeros(&request, sizeof(struct ifinfomsg));

    ifinfo->ifi_change = ifinfo->ifi_flags = IFF_UP;

    nl_msg_put_string(&request, IFLA_IFNAME, name);

    nl_msg_put_u32(&request, IFLA_MTU, MAX_MTU);

    linkinfo_off = nl_msg_start_nested(&request, IFLA_LINKINFO);

    nl_msg_put_string(&request, IFLA_INFO_KIND, kind);

    infodata_off = nl_msg_start_nested(&request, IFLA_INFO_DATA);

    /* tunnel unique info */

    switch (type) {

    case OVS_VPORT_TYPE_VXLAN:

        nl_msg_put_u8(&request, IFLA_VXLAN_LEARNING, 0);

        nl_msg_put_u8(&request, IFLA_VXLAN_COLLECT_METADATA, 1);

        nl_msg_put_u8(&request, IFLA_VXLAN_UDP_ZERO_CSUM6_RX, 1);

        if (tnl_cfg->exts & (1 << OVS_VXLAN_EXT_GBP)) {

            nl_msg_put_flag(&request, IFLA_VXLAN_GBP);

        }

        if (tnl_cfg->exts & (1 << OVS_VXLAN_EXT_GPE)) {

            nl_msg_put_flag(&request, IFLA_VXLAN_GPE);

        }

        nl_msg_put_be16(&request, IFLA_VXLAN_PORT, tnl_cfg->dst_port);

        break;

    case OVS_VPORT_TYPE_GRE:

    case OVS_VPORT_TYPE_ERSPAN:

    case OVS_VPORT_TYPE_IP6ERSPAN:

    case OVS_VPORT_TYPE_IP6GRE:

        nl_msg_put_flag(&request, IFLA_GRE_COLLECT_METADATA);

        break;

    case OVS_VPORT_TYPE_GENEVE:

        nl_msg_put_flag(&request, IFLA_GENEVE_COLLECT_METADATA);

        nl_msg_put_u8(&request, IFLA_GENEVE_UDP_ZERO_CSUM6_RX, 1);

        nl_msg_put_be16(&request, IFLA_GENEVE_PORT, tnl_cfg->dst_port);

        break;

    case OVS_VPORT_TYPE_BAREUDP:

        nl_msg_put_be16(&request, IFLA_BAREUDP_ETHERTYPE,

                        tnl_cfg->payload_ethertype);

        nl_msg_put_u16(&request, IFLA_BAREUDP_SRCPORT_MIN,

                       BAREUDP_SRCPORT_MIN);

        nl_msg_put_be16(&request, IFLA_BAREUDP_PORT, tnl_cfg->dst_port);

        if (tnl_cfg->exts & (1 << OVS_BAREUDP_EXT_MULTIPROTO_MODE)) {

            nl_msg_put_flag(&request, IFLA_BAREUDP_MULTIPROTO_MODE);

        }

        break;

    case OVS_VPORT_TYPE_NETDEV:

    case OVS_VPORT_TYPE_INTERNAL:

    case OVS_VPORT_TYPE_GTPU:

    case OVS_VPORT_TYPE_SRV6:

    case OVS_VPORT_TYPE_UNSPEC:

    case __OVS_VPORT_TYPE_MAX:

    default:

        err = EOPNOTSUPP;

        goto exit;

    }

    nl_msg_end_nested(&request, infodata_off);

    nl_msg_end_nested(&request, linkinfo_off);

    err = nl_transact(NETLINK_ROUTE, &request, NULL);

    if (!err && (type == OVS_VPORT_TYPE_GRE ||

                 type == OVS_VPORT_TYPE_IP6GRE)) {

        /* Work around a bug in kernel GRE driver, which ignores IFLA_MTU in

         * RTM_NEWLINK, by setting the MTU again.  See

         * https://bugzilla.redhat.com/show_bug.cgi?id=1488484.

         *

         * In case of MAX_MTU exceeds hw max MTU, retry a smaller value. */

        int err2 = rtnl_set_mtu(name, MAX_MTU, &request);

        if (err2) {

            err2 = rtnl_set_mtu(name, 1450, &request);

        }

        if (err2) {

            static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);

            VLOG_WARN_RL(&rl, "setting MTU of tunnel %s failed (%s)",

                         name, ovs_strerror(err2));

        }

    }

exit:

    ofpbuf_uninit(&request);

    return err;

}

int

dpif_netlink_rtnl_port_create(struct netdev *netdev)

{

    const struct netdev_tunnel_config *tnl_cfg;

    char namebuf[NETDEV_VPORT_NAME_BUFSIZE];

    enum ovs_vport_type type;

    const char *name;

    const char *kind;

    uint32_t flags;

    int err;

    type = netdev_to_ovs_vport_type(netdev_get_type(netdev));

    tnl_cfg = netdev_get_tunnel_config(netdev);

    if (!tnl_cfg) {

        return EOPNOTSUPP;

    }

    kind = vport_type_to_kind(type, tnl_cfg);

    if (!kind) {

        return EOPNOTSUPP;

    }

    name = netdev_vport_get_dpif_port(netdev, namebuf, sizeof namebuf);

    flags = NLM_F_REQUEST | NLM_F_ACK | NLM_F_CREATE | NLM_F_EXCL;

    err = dpif_netlink_rtnl_create(tnl_cfg, name, type, kind, flags);

    /* If the device exists, validate and/or attempt to recreate it. */

    if (err == EEXIST) {

        err = dpif_netlink_rtnl_verify(tnl_cfg, type, name);

        if (!err) {

            return 0;

        }

        err = dpif_netlink_rtnl_destroy(name);

        if (err) {

            static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);

            VLOG_WARN_RL(&rl, "RTNL device %s exists and cannot be "

                         "deleted: %s", name, ovs_strerror(err));

            return err;

        }

        err = dpif_netlink_rtnl_create(tnl_cfg, name, type, kind, flags);

    }

    if (err) {

        return err;

    }

    err = dpif_netlink_rtnl_verify(tnl_cfg, type, name);

    if (err) {

        int err2 = dpif_netlink_rtnl_destroy(name);

        if (err2) {

            static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);

            VLOG_WARN_RL(&rl, "Failed to delete device %s during rtnl port "

                         "creation: %s", name, ovs_strerror(err2));

        }

    }

    return err;

}

int

dpif_netlink_rtnl_port_destroy(const char *name, const char *type)

{

    switch (netdev_to_ovs_vport_type(type)) {

    case OVS_VPORT_TYPE_VXLAN:

    case OVS_VPORT_TYPE_GRE:

    case OVS_VPORT_TYPE_GENEVE:

    case OVS_VPORT_TYPE_ERSPAN:

    case OVS_VPORT_TYPE_IP6ERSPAN:

    case OVS_VPORT_TYPE_IP6GRE:

    case OVS_VPORT_TYPE_SRV6:

    case OVS_VPORT_TYPE_BAREUDP:

        return dpif_netlink_rtnl_destroy(name);

    case OVS_VPORT_TYPE_NETDEV:

    case OVS_VPORT_TYPE_INTERNAL:

    case OVS_VPORT_TYPE_GTPU:

    case OVS_VPORT_TYPE_UNSPEC:

    case __OVS_VPORT_TYPE_MAX:

    default:

        return EOPNOTSUPP;

    }

    return 0;

}

/**

 * Probe for whether the modules are out-of-tree (openvswitch) or in-tree

 * (upstream kernel).

 *

 * We probe for "ovs_geneve" via rtnetlink. As long as this returns something

 * other than EOPNOTSUPP we know that the module in use is the out-of-tree one.

 * This will be used to determine which netlink interface to use when creating

 * ports; rtnetlink or compat/genetlink.

 *

 * See ovs_tunnels_out_of_tree

 */

bool

dpif_netlink_rtnl_probe_oot_tunnels(void)

{

    char namebuf[NETDEV_VPORT_NAME_BUFSIZE];

    struct netdev *netdev = NULL;

    bool out_of_tree = false;

    const char *name;

    int error;

    error = netdev_open("ovs-system-probe", "geneve", &netdev);

    if (!error) {

        struct ofpbuf *reply;

        const struct netdev_tunnel_config *tnl_cfg;

        tnl_cfg = netdev_get_tunnel_config(netdev);

        if (!tnl_cfg) {

            netdev_close(netdev);

            return true;

        }

        name = netdev_vport_get_dpif_port(netdev, namebuf, sizeof namebuf);

        /* The geneve module exists when ovs-vswitchd crashes

         * and restarts, handle the case here.

         */

        error = dpif_netlink_rtnl_getlink(name, &reply);

        if (!error) {

            struct nlattr *linkinfo[ARRAY_SIZE(linkinfo_policy)];

            struct nlattr *rtlink[ARRAY_SIZE(rtlink_policy)];

            const char *kind;

            if (!nl_policy_parse(reply,

                                 NLMSG_HDRLEN + sizeof(struct ifinfomsg),

                                 rtlink_policy, rtlink,

                                 ARRAY_SIZE(rtlink_policy))

                || !nl_parse_nested(rtlink[IFLA_LINKINFO], linkinfo_policy,

                                    linkinfo, ARRAY_SIZE(linkinfo_policy))) {

                VLOG_ABORT("Error fetching Geneve tunnel device %s "

                           "linkinfo", name);

            }

            kind = nl_attr_get_string(linkinfo[IFLA_INFO_KIND]);

            if (!strcmp(kind, "ovs_geneve")) {

                out_of_tree = true;

            } else if (!strcmp(kind, "geneve")) {

                out_of_tree = false;

            } else {

                VLOG_ABORT("Geneve tunnel device %s with kind %s"

                           " not supported", name, kind);

            }

            ofpbuf_delete(reply);

            netdev_close(netdev);

            return out_of_tree;

        }

        error = dpif_netlink_rtnl_create(tnl_cfg, name, OVS_VPORT_TYPE_GENEVE,

                                         "ovs_geneve",

                                         (NLM_F_REQUEST | NLM_F_ACK

                                          | NLM_F_CREATE));

        if (error != EOPNOTSUPP) {

            if (!error) {

                dpif_netlink_rtnl_destroy(name);

            }

            out_of_tree = true;

        }

        netdev_close(netdev);

    }

    return out_of_tree;

}