// SPDX-License-Identifier: GPL-2.0
/* Copyright 2011-2014 Autronica Fire and Security AS
 *
 * Author(s):
 *      2011-2014 Arvid Brodin, arvid.brodin@alten.se
 *
 * Routines for handling Netlink messages for HSR and PRP.
 */

#include "hsr_netlink.h"
#include <linux/kernel.h>
#include <net/rtnetlink.h>
#include <net/genetlink.h>
#include "hsr_main.h"
#include "hsr_device.h"
#include "hsr_framereg.h"

static const struct nla_policy hsr_policy[IFLA_HSR_MAX + 1] = {
        [IFLA_HSR_SLAVE1]               = { .type = NLA_U32 },
        [IFLA_HSR_SLAVE2]               = { .type = NLA_U32 },
        [IFLA_HSR_MULTICAST_SPEC]       = { .type = NLA_U8 },
        [IFLA_HSR_VERSION]      = { .type = NLA_U8 },
        [IFLA_HSR_SUPERVISION_ADDR]     = { .len = ETH_ALEN },
        [IFLA_HSR_SEQ_NR]               = { .type = NLA_U16 },
        [IFLA_HSR_PROTOCOL]             = { .type = NLA_U8 },
        [IFLA_HSR_INTERLINK]            = { .type = NLA_U32 },
};

/* Here, it seems a netdevice has already been allocated for us, and the
 * hsr_dev_setup routine has been executed. Nice!
 */
static int hsr_newlink(struct net_device *dev,
                       struct rtnl_newlink_params *params,
                       struct netlink_ext_ack *extack)
{
        struct net *link_net = rtnl_newlink_link_net(params);
        struct net_device *link[2], *interlink = NULL;
        struct nlattr **data = params->data;
        enum hsr_version proto_version;
        unsigned char multicast_spec;
        u8 proto = HSR_PROTOCOL_HSR;

        if (!net_eq(link_net, dev_net(dev))) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "HSR slaves/interlink must be on the same net namespace than HSR link");
                return -EINVAL;
        }

        if (!data) {
                NL_SET_ERR_MSG_MOD(extack, "No slave devices specified");
                return -EINVAL;
        }
        if (!data[IFLA_HSR_SLAVE1]) {
                NL_SET_ERR_MSG_MOD(extack, "Slave1 device not specified");
                return -EINVAL;
        }
        link[0] = __dev_get_by_index(link_net,
                                     nla_get_u32(data[IFLA_HSR_SLAVE1]));
        if (!link[0]) {
                NL_SET_ERR_MSG_MOD(extack, "Slave1 does not exist");
                return -EINVAL;
        }
        if (!data[IFLA_HSR_SLAVE2]) {
                NL_SET_ERR_MSG_MOD(extack, "Slave2 device not specified");
                return -EINVAL;
        }
        link[1] = __dev_get_by_index(link_net,
                                     nla_get_u32(data[IFLA_HSR_SLAVE2]));
        if (!link[1]) {
                NL_SET_ERR_MSG_MOD(extack, "Slave2 does not exist");
                return -EINVAL;
        }

        if (link[0] == link[1]) {
                NL_SET_ERR_MSG_MOD(extack, "Slave1 and Slave2 are same");
                return -EINVAL;
        }

        if (data[IFLA_HSR_INTERLINK])
                interlink = __dev_get_by_index(link_net,
                                               nla_get_u32(data[IFLA_HSR_INTERLINK]));

        if (interlink && interlink == link[0]) {
                NL_SET_ERR_MSG_MOD(extack, "Interlink and Slave1 are the same");
                return -EINVAL;
        }

        if (interlink && interlink == link[1]) {
                NL_SET_ERR_MSG_MOD(extack, "Interlink and Slave2 are the same");
                return -EINVAL;
        }

        multicast_spec = nla_get_u8_default(data[IFLA_HSR_MULTICAST_SPEC], 0);

        if (data[IFLA_HSR_PROTOCOL])
                proto = nla_get_u8(data[IFLA_HSR_PROTOCOL]);

        if (proto >= HSR_PROTOCOL_MAX) {
                NL_SET_ERR_MSG_MOD(extack, "Unsupported protocol");
                return -EINVAL;
        }

        if (!data[IFLA_HSR_VERSION]) {
                proto_version = HSR_V0;
        } else {
                if (proto == HSR_PROTOCOL_PRP) {
                        NL_SET_ERR_MSG_MOD(extack, "PRP version unsupported");
                        return -EINVAL;
                }

                proto_version = nla_get_u8(data[IFLA_HSR_VERSION]);
                if (proto_version > HSR_V1) {
                        NL_SET_ERR_MSG_MOD(extack,
                                           "Only HSR version 0/1 supported");
                        return -EINVAL;
                }
        }

        if (proto == HSR_PROTOCOL_PRP) {
                proto_version = PRP_V1;
                if (interlink) {
                        NL_SET_ERR_MSG_MOD(extack,
                                           "Interlink only works with HSR");
                        return -EINVAL;
                }
        }

        return hsr_dev_finalize(dev, link, interlink, multicast_spec,
                                proto_version, extack);
}

static void hsr_dellink(struct net_device *dev, struct list_head *head)
{
        struct hsr_priv *hsr = netdev_priv(dev);

        timer_delete_sync(&hsr->prune_timer);
        timer_delete_sync(&hsr->prune_proxy_timer);
        timer_delete_sync(&hsr->announce_timer);
        timer_delete_sync(&hsr->announce_proxy_timer);

        hsr_debugfs_term(hsr);
        hsr_del_ports(hsr);

        hsr_del_self_node(hsr);
        hsr_del_nodes(&hsr->node_db);
        hsr_del_nodes(&hsr->proxy_node_db);

        unregister_netdevice_queue(dev, head);
}

static int hsr_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
        struct hsr_priv *hsr = netdev_priv(dev);
        u8 proto = HSR_PROTOCOL_HSR;
        struct hsr_port *port;

        port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
        if (port) {
                if (nla_put_u32(skb, IFLA_HSR_SLAVE1, port->dev->ifindex))
                        goto nla_put_failure;
        }

        port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
        if (port) {
                if (nla_put_u32(skb, IFLA_HSR_SLAVE2, port->dev->ifindex))
                        goto nla_put_failure;
        }

        port = hsr_port_get_hsr(hsr, HSR_PT_INTERLINK);
        if (port) {
                if (nla_put_u32(skb, IFLA_HSR_INTERLINK, port->dev->ifindex))
                        goto nla_put_failure;
        }

        if (nla_put(skb, IFLA_HSR_SUPERVISION_ADDR, ETH_ALEN,
                    hsr->sup_multicast_addr) ||
            nla_put_u16(skb, IFLA_HSR_SEQ_NR, hsr->sequence_nr))
                goto nla_put_failure;
        if (hsr->prot_version == PRP_V1)
                proto = HSR_PROTOCOL_PRP;
        else if (nla_put_u8(skb, IFLA_HSR_VERSION, hsr->prot_version))
                goto nla_put_failure;
        if (nla_put_u8(skb, IFLA_HSR_PROTOCOL, proto))
                goto nla_put_failure;

        return 0;

nla_put_failure:
        return -EMSGSIZE;
}

static struct rtnl_link_ops hsr_link_ops __read_mostly = {
        .kind           = "hsr",
        .maxtype        = IFLA_HSR_MAX,
        .policy         = hsr_policy,
        .priv_size      = sizeof(struct hsr_priv),
        .setup          = hsr_dev_setup,
        .newlink        = hsr_newlink,
        .dellink        = hsr_dellink,
        .fill_info      = hsr_fill_info,
};

/* attribute policy */
static const struct nla_policy hsr_genl_policy[HSR_A_MAX + 1] = {
        [HSR_A_NODE_ADDR] = { .len = ETH_ALEN },
        [HSR_A_NODE_ADDR_B] = { .len = ETH_ALEN },
        [HSR_A_IFINDEX] = { .type = NLA_U32 },
        [HSR_A_IF1_AGE] = { .type = NLA_U32 },
        [HSR_A_IF2_AGE] = { .type = NLA_U32 },
        [HSR_A_IF1_SEQ] = { .type = NLA_U16 },
        [HSR_A_IF2_SEQ] = { .type = NLA_U16 },
};

static struct genl_family hsr_genl_family;

static const struct genl_multicast_group hsr_mcgrps[] = {
        { .name = "hsr-network", },
};

/* This is called if for some node with MAC address addr, we only get frames
 * over one of the slave interfaces. This would indicate an open network ring
 * (i.e. a link has failed somewhere).
 */
void hsr_nl_ringerror(struct hsr_priv *hsr, unsigned char addr[ETH_ALEN],
                      struct hsr_port *port)
{
        struct sk_buff *skb;
        void *msg_head;
        struct hsr_port *master;
        int res;

        skb = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
        if (!skb)
                goto fail;

        msg_head = genlmsg_put(skb, 0, 0, &hsr_genl_family, 0,
                               HSR_C_RING_ERROR);
        if (!msg_head)
                goto nla_put_failure;

        res = nla_put(skb, HSR_A_NODE_ADDR, ETH_ALEN, addr);
        if (res < 0)
                goto nla_put_failure;

        res = nla_put_u32(skb, HSR_A_IFINDEX, port->dev->ifindex);
        if (res < 0)
                goto nla_put_failure;

        genlmsg_end(skb, msg_head);
        genlmsg_multicast(&hsr_genl_family, skb, 0, 0, GFP_ATOMIC);

        return;

nla_put_failure:
        kfree_skb(skb);

fail:
        rcu_read_lock();
        master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
        netdev_warn(master->dev, "Could not send HSR ring error message\n");
        rcu_read_unlock();
}

/* This is called when we haven't heard from the node with MAC address addr for
 * some time (just before the node is removed from the node table/list).
 */
void hsr_nl_nodedown(struct hsr_priv *hsr, unsigned char addr[ETH_ALEN])
{
        struct sk_buff *skb;
        void *msg_head;
        struct hsr_port *master;
        int res;

        skb = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
        if (!skb)
                goto fail;

        msg_head = genlmsg_put(skb, 0, 0, &hsr_genl_family, 0, HSR_C_NODE_DOWN);
        if (!msg_head)
                goto nla_put_failure;

        res = nla_put(skb, HSR_A_NODE_ADDR, ETH_ALEN, addr);
        if (res < 0)
                goto nla_put_failure;

        genlmsg_end(skb, msg_head);
        genlmsg_multicast(&hsr_genl_family, skb, 0, 0, GFP_ATOMIC);

        return;

nla_put_failure:
        kfree_skb(skb);

fail:
        rcu_read_lock();
        master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
        netdev_warn(master->dev, "Could not send HSR node down\n");
        rcu_read_unlock();
}

/* HSR_C_GET_NODE_STATUS lets userspace query the internal HSR node table
 * about the status of a specific node in the network, defined by its MAC
 * address.
 *
 * Input: hsr ifindex, node mac address
 * Output: hsr ifindex, node mac address (copied from request),
 *         age of latest frame from node over slave 1, slave 2 [ms]
 */
static int hsr_get_node_status(struct sk_buff *skb_in, struct genl_info *info)
{
        /* For receiving */
        struct nlattr *na;
        struct net_device *hsr_dev;

        /* For sending */
        struct sk_buff *skb_out;
        void *msg_head;
        struct hsr_priv *hsr;
        struct hsr_port *port;
        unsigned char hsr_node_addr_b[ETH_ALEN];
        int hsr_node_if1_age;
        u16 hsr_node_if1_seq;
        int hsr_node_if2_age;
        u16 hsr_node_if2_seq;
        int addr_b_ifindex;
        int res;

        if (!info)
                goto invalid;

        na = info->attrs[HSR_A_IFINDEX];
        if (!na)
                goto invalid;
        na = info->attrs[HSR_A_NODE_ADDR];
        if (!na)
                goto invalid;

        rcu_read_lock();
        hsr_dev = dev_get_by_index_rcu(genl_info_net(info),
                                       nla_get_u32(info->attrs[HSR_A_IFINDEX]));
        if (!hsr_dev)
                goto rcu_unlock;
        if (!is_hsr_master(hsr_dev))
                goto rcu_unlock;

        /* Send reply */
        skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
        if (!skb_out) {
                res = -ENOMEM;
                goto fail;
        }

        msg_head = genlmsg_put(skb_out, NETLINK_CB(skb_in).portid,
                               info->snd_seq, &hsr_genl_family, 0,
                               HSR_C_SET_NODE_STATUS);
        if (!msg_head) {
                res = -ENOMEM;
                goto nla_put_failure;
        }

        res = nla_put_u32(skb_out, HSR_A_IFINDEX, hsr_dev->ifindex);
        if (res < 0)
                goto nla_put_failure;

        hsr = netdev_priv(hsr_dev);
        res = hsr_get_node_data(hsr,
                                (unsigned char *)
                                nla_data(info->attrs[HSR_A_NODE_ADDR]),
                                         hsr_node_addr_b,
                                         &addr_b_ifindex,
                                         &hsr_node_if1_age,
                                         &hsr_node_if1_seq,
                                         &hsr_node_if2_age,
                                         &hsr_node_if2_seq);
        if (res < 0)
                goto nla_put_failure;

        res = nla_put(skb_out, HSR_A_NODE_ADDR, ETH_ALEN,
                      nla_data(info->attrs[HSR_A_NODE_ADDR]));
        if (res < 0)
                goto nla_put_failure;

        if (addr_b_ifindex > -1) {
                res = nla_put(skb_out, HSR_A_NODE_ADDR_B, ETH_ALEN,
                              hsr_node_addr_b);
                if (res < 0)
                        goto nla_put_failure;

                res = nla_put_u32(skb_out, HSR_A_ADDR_B_IFINDEX,
                                  addr_b_ifindex);
                if (res < 0)
                        goto nla_put_failure;
        }

        res = nla_put_u32(skb_out, HSR_A_IF1_AGE, hsr_node_if1_age);
        if (res < 0)
                goto nla_put_failure;
        res = nla_put_u16(skb_out, HSR_A_IF1_SEQ, hsr_node_if1_seq);
        if (res < 0)
                goto nla_put_failure;
        port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
        if (port)
                res = nla_put_u32(skb_out, HSR_A_IF1_IFINDEX,
                                  port->dev->ifindex);
        if (res < 0)
                goto nla_put_failure;

        res = nla_put_u32(skb_out, HSR_A_IF2_AGE, hsr_node_if2_age);
        if (res < 0)
                goto nla_put_failure;
        res = nla_put_u16(skb_out, HSR_A_IF2_SEQ, hsr_node_if2_seq);
        if (res < 0)
                goto nla_put_failure;
        port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
        if (port)
                res = nla_put_u32(skb_out, HSR_A_IF2_IFINDEX,
                                  port->dev->ifindex);
        if (res < 0)
                goto nla_put_failure;

        rcu_read_unlock();

        genlmsg_end(skb_out, msg_head);
        genlmsg_unicast(genl_info_net(info), skb_out, info->snd_portid);

        return 0;

rcu_unlock:
        rcu_read_unlock();
invalid:
        netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL, NULL);
        return 0;

nla_put_failure:
        kfree_skb(skb_out);
        /* Fall through */

fail:
        rcu_read_unlock();
        return res;
}

/* Get a list of MacAddressA of all nodes known to this node (including self).
 */
static int hsr_get_node_list(struct sk_buff *skb_in, struct genl_info *info)
{
        unsigned char addr[ETH_ALEN];
        struct net_device *hsr_dev;
        struct sk_buff *skb_out;
        struct hsr_priv *hsr;
        bool restart = false;
        struct nlattr *na;
        void *pos = NULL;
        void *msg_head;
        int res;

        if (!info)
                goto invalid;

        na = info->attrs[HSR_A_IFINDEX];
        if (!na)
                goto invalid;

        rcu_read_lock();
        hsr_dev = dev_get_by_index_rcu(genl_info_net(info),
                                       nla_get_u32(info->attrs[HSR_A_IFINDEX]));
        if (!hsr_dev)
                goto rcu_unlock;
        if (!is_hsr_master(hsr_dev))
                goto rcu_unlock;

restart:
        /* Send reply */
        skb_out = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_ATOMIC);
        if (!skb_out) {
                res = -ENOMEM;
                goto fail;
        }

        msg_head = genlmsg_put(skb_out, NETLINK_CB(skb_in).portid,
                               info->snd_seq, &hsr_genl_family, 0,
                               HSR_C_SET_NODE_LIST);
        if (!msg_head) {
                res = -ENOMEM;
                goto nla_put_failure;
        }

        if (!restart) {
                res = nla_put_u32(skb_out, HSR_A_IFINDEX, hsr_dev->ifindex);
                if (res < 0)
                        goto nla_put_failure;
        }

        hsr = netdev_priv(hsr_dev);

        if (!pos)
                pos = hsr_get_next_node(hsr, NULL, addr);
        while (pos) {
                res = nla_put(skb_out, HSR_A_NODE_ADDR, ETH_ALEN, addr);
                if (res < 0) {
                        if (res == -EMSGSIZE) {
                                genlmsg_end(skb_out, msg_head);
                                genlmsg_unicast(genl_info_net(info), skb_out,
                                                info->snd_portid);
                                restart = true;
                                goto restart;
                        }
                        goto nla_put_failure;
                }
                pos = hsr_get_next_node(hsr, pos, addr);
        }
        rcu_read_unlock();

        genlmsg_end(skb_out, msg_head);
        genlmsg_unicast(genl_info_net(info), skb_out, info->snd_portid);

        return 0;

rcu_unlock:
        rcu_read_unlock();
invalid:
        netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL, NULL);
        return 0;

nla_put_failure:
        nlmsg_free(skb_out);
        /* Fall through */

fail:
        rcu_read_unlock();
        return res;
}

static const struct genl_small_ops hsr_ops[] = {
        {
                .cmd = HSR_C_GET_NODE_STATUS,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .flags = 0,
                .doit = hsr_get_node_status,
                .dumpit = NULL,
        },
        {
                .cmd = HSR_C_GET_NODE_LIST,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .flags = 0,
                .doit = hsr_get_node_list,
                .dumpit = NULL,
        },
};

static struct genl_family hsr_genl_family __ro_after_init = {
        .hdrsize = 0,
        .name = "HSR",
        .version = 1,
        .maxattr = HSR_A_MAX,
        .policy = hsr_genl_policy,
        .netnsok = true,
        .module = THIS_MODULE,
        .small_ops = hsr_ops,
        .n_small_ops = ARRAY_SIZE(hsr_ops),
        .resv_start_op = HSR_C_SET_NODE_LIST + 1,
        .mcgrps = hsr_mcgrps,
        .n_mcgrps = ARRAY_SIZE(hsr_mcgrps),
};

int __init hsr_netlink_init(void)
{
        int rc;

        rc = rtnl_link_register(&hsr_link_ops);
        if (rc)
                goto fail_rtnl_link_register;

        rc = genl_register_family(&hsr_genl_family);
        if (rc)
                goto fail_genl_register_family;

        hsr_debugfs_create_root();
        return 0;

fail_genl_register_family:
        rtnl_link_unregister(&hsr_link_ops);
fail_rtnl_link_register:

        return rc;
}

void __exit hsr_netlink_exit(void)
{
        genl_unregister_family(&hsr_genl_family);
        rtnl_link_unregister(&hsr_link_ops);
}

MODULE_ALIAS_RTNL_LINK("hsr");