// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *      Bridge per vlan tunnel port dst_metadata netlink control interface
 *
 *      Authors:
 *      Roopa Prabhu            <roopa@cumulusnetworks.com>
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/etherdevice.h>
#include <net/rtnetlink.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <uapi/linux/if_bridge.h>
#include <net/dst_metadata.h>

#include "br_private.h"
#include "br_private_tunnel.h"

static size_t __get_vlan_tinfo_size(void)
{
        return nla_total_size(0) + /* nest IFLA_BRIDGE_VLAN_TUNNEL_INFO */
                  nla_total_size(sizeof(u32)) + /* IFLA_BRIDGE_VLAN_TUNNEL_ID */
                  nla_total_size(sizeof(u16)) + /* IFLA_BRIDGE_VLAN_TUNNEL_VID */
                  nla_total_size(sizeof(u16)); /* IFLA_BRIDGE_VLAN_TUNNEL_FLAGS */
}

bool vlan_tunid_inrange(const struct net_bridge_vlan *v_curr,
                        const struct net_bridge_vlan *v_last)
{
        __be32 tunid_curr = tunnel_id_to_key32(v_curr->tinfo.tunnel_id);
        __be32 tunid_last = tunnel_id_to_key32(v_last->tinfo.tunnel_id);

        return (be32_to_cpu(tunid_curr) - be32_to_cpu(tunid_last)) == 1;
}

static int __get_num_vlan_tunnel_infos(struct net_bridge_vlan_group *vg)
{
        struct net_bridge_vlan *v, *vtbegin = NULL, *vtend = NULL;
        int num_tinfos = 0;

        /* Count number of vlan infos */
        list_for_each_entry_rcu(v, &vg->vlan_list, vlist) {
                /* only a context, bridge vlan not activated */
                if (!br_vlan_should_use(v) || !v->tinfo.tunnel_id)
                        continue;

                if (!vtbegin) {
                        goto initvars;
                } else if ((v->vid - vtend->vid) == 1 &&
                           vlan_tunid_inrange(v, vtend)) {
                        vtend = v;
                        continue;
                } else {
                        if ((vtend->vid - vtbegin->vid) > 0)
                                num_tinfos += 2;
                        else
                                num_tinfos += 1;
                }
initvars:
                vtbegin = v;
                vtend = v;
        }

        if (vtbegin && vtend) {
                if ((vtend->vid - vtbegin->vid) > 0)
                        num_tinfos += 2;
                else
                        num_tinfos += 1;
        }

        return num_tinfos;
}

int br_get_vlan_tunnel_info_size(struct net_bridge_vlan_group *vg)
{
        int num_tinfos;

        if (!vg)
                return 0;

        rcu_read_lock();
        num_tinfos = __get_num_vlan_tunnel_infos(vg);
        rcu_read_unlock();

        return num_tinfos * __get_vlan_tinfo_size();
}

static int br_fill_vlan_tinfo(struct sk_buff *skb, u16 vid,
                              __be64 tunnel_id, u16 flags)
{
        __be32 tid = tunnel_id_to_key32(tunnel_id);
        struct nlattr *tmap;

        tmap = nla_nest_start_noflag(skb, IFLA_BRIDGE_VLAN_TUNNEL_INFO);
        if (!tmap)
                return -EMSGSIZE;
        if (nla_put_u32(skb, IFLA_BRIDGE_VLAN_TUNNEL_ID,
                        be32_to_cpu(tid)))
                goto nla_put_failure;
        if (nla_put_u16(skb, IFLA_BRIDGE_VLAN_TUNNEL_VID,
                        vid))
                goto nla_put_failure;
        if (nla_put_u16(skb, IFLA_BRIDGE_VLAN_TUNNEL_FLAGS,
                        flags))
                goto nla_put_failure;
        nla_nest_end(skb, tmap);

        return 0;

nla_put_failure:
        nla_nest_cancel(skb, tmap);

        return -EMSGSIZE;
}

static int br_fill_vlan_tinfo_range(struct sk_buff *skb,
                                    struct net_bridge_vlan *vtbegin,
                                    struct net_bridge_vlan *vtend)
{
        int err;

        if (vtend && (vtend->vid - vtbegin->vid) > 0) {
                /* add range to skb */
                err = br_fill_vlan_tinfo(skb, vtbegin->vid,
                                         vtbegin->tinfo.tunnel_id,
                                         BRIDGE_VLAN_INFO_RANGE_BEGIN);
                if (err)
                        return err;

                err = br_fill_vlan_tinfo(skb, vtend->vid,
                                         vtend->tinfo.tunnel_id,
                                         BRIDGE_VLAN_INFO_RANGE_END);
                if (err)
                        return err;
        } else {
                err = br_fill_vlan_tinfo(skb, vtbegin->vid,
                                         vtbegin->tinfo.tunnel_id,
                                         0);
                if (err)
                        return err;
        }

        return 0;
}

int br_fill_vlan_tunnel_info(struct sk_buff *skb,
                             struct net_bridge_vlan_group *vg)
{
        struct net_bridge_vlan *vtbegin = NULL;
        struct net_bridge_vlan *vtend = NULL;
        struct net_bridge_vlan *v;
        int err;

        /* Count number of vlan infos */
        list_for_each_entry_rcu(v, &vg->vlan_list, vlist) {
                /* only a context, bridge vlan not activated */
                if (!br_vlan_should_use(v))
                        continue;

                if (!v->tinfo.tunnel_dst)
                        continue;

                if (!vtbegin) {
                        goto initvars;
                } else if ((v->vid - vtend->vid) == 1 &&
                            vlan_tunid_inrange(v, vtend)) {
                        vtend = v;
                        continue;
                } else {
                        err = br_fill_vlan_tinfo_range(skb, vtbegin, vtend);
                        if (err)
                                return err;
                }
initvars:
                vtbegin = v;
                vtend = v;
        }

        if (vtbegin) {
                err = br_fill_vlan_tinfo_range(skb, vtbegin, vtend);
                if (err)
                        return err;
        }

        return 0;
}

static const struct nla_policy vlan_tunnel_policy[IFLA_BRIDGE_VLAN_TUNNEL_MAX + 1] = {
        [IFLA_BRIDGE_VLAN_TUNNEL_UNSPEC] = {
                .strict_start_type = IFLA_BRIDGE_VLAN_TUNNEL_FLAGS + 1
        },
        [IFLA_BRIDGE_VLAN_TUNNEL_ID] = { .type = NLA_U32 },
        [IFLA_BRIDGE_VLAN_TUNNEL_VID] = { .type = NLA_U16 },
        [IFLA_BRIDGE_VLAN_TUNNEL_FLAGS] = { .type = NLA_U16 },
};

int br_vlan_tunnel_info(const struct net_bridge_port *p, int cmd,
                        u16 vid, u32 tun_id, bool *changed)
{
        int err = 0;

        if (!p)
                return -EINVAL;

        switch (cmd) {
        case RTM_SETLINK:
                err = nbp_vlan_tunnel_info_add(p, vid, tun_id);
                if (!err)
                        *changed = true;
                break;
        case RTM_DELLINK:
                if (!nbp_vlan_tunnel_info_delete(p, vid))
                        *changed = true;
                break;
        }

        return err;
}

int br_parse_vlan_tunnel_info(struct nlattr *attr,
                              struct vtunnel_info *tinfo)
{
        struct nlattr *tb[IFLA_BRIDGE_VLAN_TUNNEL_MAX + 1];
        u32 tun_id;
        u16 vid, flags = 0;
        int err;

        memset(tinfo, 0, sizeof(*tinfo));

        err = nla_parse_nested_deprecated(tb, IFLA_BRIDGE_VLAN_TUNNEL_MAX,
                                          attr, vlan_tunnel_policy, NULL);
        if (err < 0)
                return err;

        if (!tb[IFLA_BRIDGE_VLAN_TUNNEL_ID] ||
            !tb[IFLA_BRIDGE_VLAN_TUNNEL_VID])
                return -EINVAL;

        tun_id = nla_get_u32(tb[IFLA_BRIDGE_VLAN_TUNNEL_ID]);
        vid = nla_get_u16(tb[IFLA_BRIDGE_VLAN_TUNNEL_VID]);
        if (vid >= VLAN_VID_MASK)
                return -ERANGE;

        if (tb[IFLA_BRIDGE_VLAN_TUNNEL_FLAGS])
                flags = nla_get_u16(tb[IFLA_BRIDGE_VLAN_TUNNEL_FLAGS]);

        tinfo->tunid = tun_id;
        tinfo->vid = vid;
        tinfo->flags = flags;

        return 0;
}

/* send a notification if v_curr can't enter the range and start a new one */
static void __vlan_tunnel_handle_range(const struct net_bridge_port *p,
                                       struct net_bridge_vlan **v_start,
                                       struct net_bridge_vlan **v_end,
                                       int v_curr, bool curr_change)
{
        struct net_bridge_vlan_group *vg;
        struct net_bridge_vlan *v;

        vg = nbp_vlan_group(p);
        if (!vg)
                return;

        v = br_vlan_find(vg, v_curr);

        if (!*v_start)
                goto out_init;

        if (v && curr_change && br_vlan_can_enter_range(v, *v_end)) {
                *v_end = v;
                return;
        }

        br_vlan_notify(p->br, p, (*v_start)->vid, (*v_end)->vid, RTM_NEWVLAN);
out_init:
        /* we start a range only if there are any changes to notify about */
        *v_start = curr_change ? v : NULL;
        *v_end = *v_start;
}

int br_process_vlan_tunnel_info(const struct net_bridge *br,
                                const struct net_bridge_port *p, int cmd,
                                struct vtunnel_info *tinfo_curr,
                                struct vtunnel_info *tinfo_last,
                                bool *changed)
{
        int err;

        if (tinfo_curr->flags & BRIDGE_VLAN_INFO_RANGE_BEGIN) {
                if (tinfo_last->flags & BRIDGE_VLAN_INFO_RANGE_BEGIN)
                        return -EINVAL;
                memcpy(tinfo_last, tinfo_curr, sizeof(struct vtunnel_info));
        } else if (tinfo_curr->flags & BRIDGE_VLAN_INFO_RANGE_END) {
                struct net_bridge_vlan *v_start = NULL, *v_end = NULL;
                int t, v;

                if (!(tinfo_last->flags & BRIDGE_VLAN_INFO_RANGE_BEGIN))
                        return -EINVAL;
                if ((tinfo_curr->vid - tinfo_last->vid) !=
                    (tinfo_curr->tunid - tinfo_last->tunid))
                        return -EINVAL;
                t = tinfo_last->tunid;
                for (v = tinfo_last->vid; v <= tinfo_curr->vid; v++) {
                        bool curr_change = false;

                        err = br_vlan_tunnel_info(p, cmd, v, t, &curr_change);
                        if (err)
                                break;
                        t++;

                        if (curr_change)
                                *changed = curr_change;
                        __vlan_tunnel_handle_range(p, &v_start, &v_end, v,
                                                   curr_change);
                }
                if (v_start && v_end)
                        br_vlan_notify(br, p, v_start->vid, v_end->vid,
                                       RTM_NEWVLAN);
                if (err)
                        return err;

                memset(tinfo_last, 0, sizeof(struct vtunnel_info));
                memset(tinfo_curr, 0, sizeof(struct vtunnel_info));
        } else {
                if (tinfo_last->flags)
                        return -EINVAL;
                err = br_vlan_tunnel_info(p, cmd, tinfo_curr->vid,
                                          tinfo_curr->tunid, changed);
                if (err)
                        return err;
                br_vlan_notify(br, p, tinfo_curr->vid, 0, RTM_NEWVLAN);
                memset(tinfo_last, 0, sizeof(struct vtunnel_info));
                memset(tinfo_curr, 0, sizeof(struct vtunnel_info));
        }

        return 0;
}