/*
 * Copyright (C) 2017 Netronome Systems, Inc.
 *
 * This software is dual licensed under the GNU General License Version 2,
 * June 1991 as shown in the file COPYING in the top-level directory of this
 * source tree or the BSD 2-Clause License provided below.  You have the
 * option to license this software under the complete terms of either license.
 *
 * The BSD 2-Clause License:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      1. Redistributions of source code must retain the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer.
 *
 *      2. Redistributions in binary form must reproduce the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer in the documentation and/or other materials
 *         provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/bitfield.h>
#include <net/pkt_cls.h>
#include <net/switchdev.h>
#include <net/tc_act/tc_gact.h>
#include <net/tc_act/tc_mirred.h>
#include <net/tc_act/tc_pedit.h>
#include <net/tc_act/tc_vlan.h>
#include <net/tc_act/tc_tunnel_key.h>

#include "cmsg.h"
#include "main.h"
#include "../nfp_net_repr.h"

static void nfp_fl_pop_vlan(struct nfp_fl_pop_vlan *pop_vlan)
{
        size_t act_size = sizeof(struct nfp_fl_pop_vlan);
        u16 tmp_pop_vlan_op;

        tmp_pop_vlan_op =
                FIELD_PREP(NFP_FL_ACT_LEN_LW, act_size >> NFP_FL_LW_SIZ) |
                FIELD_PREP(NFP_FL_ACT_JMP_ID, NFP_FL_ACTION_OPCODE_POP_VLAN);

        pop_vlan->a_op = cpu_to_be16(tmp_pop_vlan_op);
        pop_vlan->reserved = 0;
}

static void
nfp_fl_push_vlan(struct nfp_fl_push_vlan *push_vlan,
                 const struct tc_action *action)
{
        size_t act_size = sizeof(struct nfp_fl_push_vlan);
        struct tcf_vlan *vlan = to_vlan(action);
        u16 tmp_push_vlan_tci;
        u16 tmp_push_vlan_op;

        tmp_push_vlan_op =
                FIELD_PREP(NFP_FL_ACT_LEN_LW, act_size >> NFP_FL_LW_SIZ) |
                FIELD_PREP(NFP_FL_ACT_JMP_ID, NFP_FL_ACTION_OPCODE_PUSH_VLAN);

        push_vlan->a_op = cpu_to_be16(tmp_push_vlan_op);
        /* Set action push vlan parameters. */
        push_vlan->reserved = 0;
        push_vlan->vlan_tpid = tcf_vlan_push_proto(action);

        tmp_push_vlan_tci =
                FIELD_PREP(NFP_FL_PUSH_VLAN_PRIO, vlan->tcfv_push_prio) |
                FIELD_PREP(NFP_FL_PUSH_VLAN_VID, vlan->tcfv_push_vid) |
                NFP_FL_PUSH_VLAN_CFI;
        push_vlan->vlan_tci = cpu_to_be16(tmp_push_vlan_tci);
}

static bool nfp_fl_netdev_is_tunnel_type(struct net_device *out_dev,
                                         enum nfp_flower_tun_type tun_type)
{
        if (!out_dev->rtnl_link_ops)
                return false;

        if (!strcmp(out_dev->rtnl_link_ops->kind, "vxlan"))
                return tun_type == NFP_FL_TUNNEL_VXLAN;

        return false;
}

static int
nfp_fl_output(struct nfp_fl_output *output, const struct tc_action *action,
              struct nfp_fl_payload *nfp_flow, bool last,
              struct net_device *in_dev, enum nfp_flower_tun_type tun_type,
              int *tun_out_cnt)
{
        size_t act_size = sizeof(struct nfp_fl_output);
        u16 tmp_output_op, tmp_flags;
        struct net_device *out_dev;
        int ifindex;

        /* Set action opcode to output action. */
        tmp_output_op =
                FIELD_PREP(NFP_FL_ACT_LEN_LW, act_size >> NFP_FL_LW_SIZ) |
                FIELD_PREP(NFP_FL_ACT_JMP_ID, NFP_FL_ACTION_OPCODE_OUTPUT);

        output->a_op = cpu_to_be16(tmp_output_op);

        ifindex = tcf_mirred_ifindex(action);
        out_dev = __dev_get_by_index(dev_net(in_dev), ifindex);
        if (!out_dev)
                return -EOPNOTSUPP;

        tmp_flags = last ? NFP_FL_OUT_FLAGS_LAST : 0;

        if (tun_type) {
                /* Verify the egress netdev matches the tunnel type. */
                if (!nfp_fl_netdev_is_tunnel_type(out_dev, tun_type))
                        return -EOPNOTSUPP;

                if (*tun_out_cnt)
                        return -EOPNOTSUPP;
                (*tun_out_cnt)++;

                output->flags = cpu_to_be16(tmp_flags |
                                            NFP_FL_OUT_FLAGS_USE_TUN);
                output->port = cpu_to_be32(NFP_FL_PORT_TYPE_TUN | tun_type);
        } else {
                /* Set action output parameters. */
                output->flags = cpu_to_be16(tmp_flags);

                /* Only offload if egress ports are on the same device as the
                 * ingress port.
                 */
                if (!switchdev_port_same_parent_id(in_dev, out_dev))
                        return -EOPNOTSUPP;
                if (!nfp_netdev_is_nfp_repr(out_dev))
                        return -EOPNOTSUPP;

                output->port = cpu_to_be32(nfp_repr_get_port_id(out_dev));
                if (!output->port)
                        return -EOPNOTSUPP;
        }
        nfp_flow->meta.shortcut = output->port;

        return 0;
}

static bool nfp_fl_supported_tun_port(const struct tc_action *action)
{
        struct ip_tunnel_info *tun = tcf_tunnel_info(action);

        return tun->key.tp_dst == htons(NFP_FL_VXLAN_PORT);
}

static struct nfp_fl_pre_tunnel *nfp_fl_pre_tunnel(char *act_data, int act_len)
{
        size_t act_size = sizeof(struct nfp_fl_pre_tunnel);
        struct nfp_fl_pre_tunnel *pre_tun_act;
        u16 tmp_pre_tun_op;

        /* Pre_tunnel action must be first on action list.
         * If other actions already exist they need pushed forward.
         */
        if (act_len)
                memmove(act_data + act_size, act_data, act_len);

        pre_tun_act = (struct nfp_fl_pre_tunnel *)act_data;

        memset(pre_tun_act, 0, act_size);

        tmp_pre_tun_op =
                FIELD_PREP(NFP_FL_ACT_LEN_LW, act_size >> NFP_FL_LW_SIZ) |
                FIELD_PREP(NFP_FL_ACT_JMP_ID, NFP_FL_ACTION_OPCODE_PRE_TUNNEL);

        pre_tun_act->a_op = cpu_to_be16(tmp_pre_tun_op);

        return pre_tun_act;
}

static int
nfp_fl_set_vxlan(struct nfp_fl_set_vxlan *set_vxlan,
                 const struct tc_action *action,
                 struct nfp_fl_pre_tunnel *pre_tun)
{
        struct ip_tunnel_info *vxlan = tcf_tunnel_info(action);
        size_t act_size = sizeof(struct nfp_fl_set_vxlan);
        u32 tmp_set_vxlan_type_index = 0;
        u16 tmp_set_vxlan_op;
        /* Currently support one pre-tunnel so index is always 0. */
        int pretun_idx = 0;

        if (vxlan->options_len) {
                /* Do not support options e.g. vxlan gpe. */
                return -EOPNOTSUPP;
        }

        tmp_set_vxlan_op =
                FIELD_PREP(NFP_FL_ACT_LEN_LW, act_size >> NFP_FL_LW_SIZ) |
                FIELD_PREP(NFP_FL_ACT_JMP_ID,
                           NFP_FL_ACTION_OPCODE_SET_IPV4_TUNNEL);

        set_vxlan->a_op = cpu_to_be16(tmp_set_vxlan_op);

        /* Set tunnel type and pre-tunnel index. */
        tmp_set_vxlan_type_index |=
                FIELD_PREP(NFP_FL_IPV4_TUNNEL_TYPE, NFP_FL_TUNNEL_VXLAN) |
                FIELD_PREP(NFP_FL_IPV4_PRE_TUN_INDEX, pretun_idx);

        set_vxlan->tun_type_index = cpu_to_be32(tmp_set_vxlan_type_index);

        set_vxlan->tun_id = vxlan->key.tun_id;
        set_vxlan->tun_flags = vxlan->key.tun_flags;
        set_vxlan->ipv4_ttl = vxlan->key.ttl;
        set_vxlan->ipv4_tos = vxlan->key.tos;

        /* Complete pre_tunnel action. */
        pre_tun->ipv4_dst = vxlan->key.u.ipv4.dst;

        return 0;
}

static void nfp_fl_set_helper32(u32 value, u32 mask, u8 *p_exact, u8 *p_mask)
{
        u32 oldvalue = get_unaligned((u32 *)p_exact);
        u32 oldmask = get_unaligned((u32 *)p_mask);

        value &= mask;
        value |= oldvalue & ~mask;

        put_unaligned(oldmask | mask, (u32 *)p_mask);
        put_unaligned(value, (u32 *)p_exact);
}

static int
nfp_fl_set_eth(const struct tc_action *action, int idx, u32 off,
               struct nfp_fl_set_eth *set_eth)
{
        u16 tmp_set_eth_op;
        u32 exact, mask;

        if (off + 4 > ETH_ALEN * 2)
                return -EOPNOTSUPP;

        mask = ~tcf_pedit_mask(action, idx);
        exact = tcf_pedit_val(action, idx);

        if (exact & ~mask)
                return -EOPNOTSUPP;

        nfp_fl_set_helper32(exact, mask, &set_eth->eth_addr_val[off],
                            &set_eth->eth_addr_mask[off]);

        set_eth->reserved = cpu_to_be16(0);
        tmp_set_eth_op = FIELD_PREP(NFP_FL_ACT_LEN_LW,
                                    sizeof(*set_eth) >> NFP_FL_LW_SIZ) |
                         FIELD_PREP(NFP_FL_ACT_JMP_ID,
                                    NFP_FL_ACTION_OPCODE_SET_ETHERNET);
        set_eth->a_op = cpu_to_be16(tmp_set_eth_op);

        return 0;
}

static int
nfp_fl_set_ip4(const struct tc_action *action, int idx, u32 off,
               struct nfp_fl_set_ip4_addrs *set_ip_addr)
{
        u16 tmp_set_ipv4_op;
        __be32 exact, mask;

        /* We are expecting tcf_pedit to return a big endian value */
        mask = (__force __be32)~tcf_pedit_mask(action, idx);
        exact = (__force __be32)tcf_pedit_val(action, idx);

        if (exact & ~mask)
                return -EOPNOTSUPP;

        switch (off) {
        case offsetof(struct iphdr, daddr):
                set_ip_addr->ipv4_dst_mask = mask;
                set_ip_addr->ipv4_dst = exact;
                break;
        case offsetof(struct iphdr, saddr):
                set_ip_addr->ipv4_src_mask = mask;
                set_ip_addr->ipv4_src = exact;
                break;
        default:
                return -EOPNOTSUPP;
        }

        set_ip_addr->reserved = cpu_to_be16(0);
        tmp_set_ipv4_op = FIELD_PREP(NFP_FL_ACT_LEN_LW,
                                     sizeof(*set_ip_addr) >> NFP_FL_LW_SIZ) |
                          FIELD_PREP(NFP_FL_ACT_JMP_ID,
                                     NFP_FL_ACTION_OPCODE_SET_IPV4_ADDRS);
        set_ip_addr->a_op = cpu_to_be16(tmp_set_ipv4_op);

        return 0;
}

static void
nfp_fl_set_ip6_helper(int opcode_tag, int idx, __be32 exact, __be32 mask,
                      struct nfp_fl_set_ipv6_addr *ip6)
{
        u16 tmp_set_op;

        ip6->ipv6[idx % 4].mask = mask;
        ip6->ipv6[idx % 4].exact = exact;

        ip6->reserved = cpu_to_be16(0);
        tmp_set_op = FIELD_PREP(NFP_FL_ACT_LEN_LW, sizeof(*ip6) >>
                                NFP_FL_LW_SIZ) |
                     FIELD_PREP(NFP_FL_ACT_JMP_ID, opcode_tag);
        ip6->a_op = cpu_to_be16(tmp_set_op);
}

static int
nfp_fl_set_ip6(const struct tc_action *action, int idx, u32 off,
               struct nfp_fl_set_ipv6_addr *ip_dst,
               struct nfp_fl_set_ipv6_addr *ip_src)
{
        __be32 exact, mask;

        /* We are expecting tcf_pedit to return a big endian value */
        mask = (__force __be32)~tcf_pedit_mask(action, idx);
        exact = (__force __be32)tcf_pedit_val(action, idx);

        if (exact & ~mask)
                return -EOPNOTSUPP;

        if (off < offsetof(struct ipv6hdr, saddr))
                return -EOPNOTSUPP;
        else if (off < offsetof(struct ipv6hdr, daddr))
                nfp_fl_set_ip6_helper(NFP_FL_ACTION_OPCODE_SET_IPV6_SRC, idx,
                                      exact, mask, ip_src);
        else if (off < offsetof(struct ipv6hdr, daddr) +
                       sizeof(struct in6_addr))
                nfp_fl_set_ip6_helper(NFP_FL_ACTION_OPCODE_SET_IPV6_DST, idx,
                                      exact, mask, ip_dst);
        else
                return -EOPNOTSUPP;

        return 0;
}

static int
nfp_fl_set_tport(const struct tc_action *action, int idx, u32 off,
                 struct nfp_fl_set_tport *set_tport, int opcode)
{
        u32 exact, mask;
        u16 tmp_set_op;

        if (off)
                return -EOPNOTSUPP;

        mask = ~tcf_pedit_mask(action, idx);
        exact = tcf_pedit_val(action, idx);

        if (exact & ~mask)
                return -EOPNOTSUPP;

        nfp_fl_set_helper32(exact, mask, set_tport->tp_port_val,
                            set_tport->tp_port_mask);

        set_tport->reserved = cpu_to_be16(0);
        tmp_set_op = FIELD_PREP(NFP_FL_ACT_LEN_LW,
                                sizeof(*set_tport) >> NFP_FL_LW_SIZ);
        tmp_set_op |= FIELD_PREP(NFP_FL_ACT_JMP_ID, opcode);
        set_tport->a_op = cpu_to_be16(tmp_set_op);

        return 0;
}

static int
nfp_fl_pedit(const struct tc_action *action, char *nfp_action, int *a_len)
{
        struct nfp_fl_set_ipv6_addr set_ip6_dst, set_ip6_src;
        struct nfp_fl_set_ip4_addrs set_ip_addr;
        struct nfp_fl_set_tport set_tport;
        struct nfp_fl_set_eth set_eth;
        enum pedit_header_type htype;
        int idx, nkeys, err;
        size_t act_size;
        u32 offset, cmd;

        memset(&set_ip6_dst, 0, sizeof(set_ip6_dst));
        memset(&set_ip6_src, 0, sizeof(set_ip6_src));
        memset(&set_ip_addr, 0, sizeof(set_ip_addr));
        memset(&set_tport, 0, sizeof(set_tport));
        memset(&set_eth, 0, sizeof(set_eth));
        nkeys = tcf_pedit_nkeys(action);

        for (idx = 0; idx < nkeys; idx++) {
                cmd = tcf_pedit_cmd(action, idx);
                htype = tcf_pedit_htype(action, idx);
                offset = tcf_pedit_offset(action, idx);

                if (cmd != TCA_PEDIT_KEY_EX_CMD_SET)
                        return -EOPNOTSUPP;

                switch (htype) {
                case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH:
                        err = nfp_fl_set_eth(action, idx, offset, &set_eth);
                        break;
                case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4:
                        err = nfp_fl_set_ip4(action, idx, offset, &set_ip_addr);
                        break;
                case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6:
                        err = nfp_fl_set_ip6(action, idx, offset, &set_ip6_dst,
                                             &set_ip6_src);
                        break;
                case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP:
                        err = nfp_fl_set_tport(action, idx, offset, &set_tport,
                                               NFP_FL_ACTION_OPCODE_SET_TCP);
                        break;
                case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP:
                        err = nfp_fl_set_tport(action, idx, offset, &set_tport,
                                               NFP_FL_ACTION_OPCODE_SET_UDP);
                        break;
                default:
                        return -EOPNOTSUPP;
                }
                if (err)
                        return err;
        }

        if (set_eth.a_op) {
                act_size = sizeof(set_eth);
                memcpy(nfp_action, &set_eth, act_size);
                *a_len += act_size;
        } else if (set_ip_addr.a_op) {
                act_size = sizeof(set_ip_addr);
                memcpy(nfp_action, &set_ip_addr, act_size);
                *a_len += act_size;
        } else if (set_ip6_dst.a_op && set_ip6_src.a_op) {
                /* TC compiles set src and dst IPv6 address as a single action,
                 * the hardware requires this to be 2 separate actions.
                 */
                act_size = sizeof(set_ip6_src);
                memcpy(nfp_action, &set_ip6_src, act_size);
                *a_len += act_size;

                act_size = sizeof(set_ip6_dst);
                memcpy(&nfp_action[sizeof(set_ip6_src)], &set_ip6_dst,
                       act_size);
                *a_len += act_size;
        } else if (set_ip6_dst.a_op) {
                act_size = sizeof(set_ip6_dst);
                memcpy(nfp_action, &set_ip6_dst, act_size);
                *a_len += act_size;
        } else if (set_ip6_src.a_op) {
                act_size = sizeof(set_ip6_src);
                memcpy(nfp_action, &set_ip6_src, act_size);
                *a_len += act_size;
        } else if (set_tport.a_op) {
                act_size = sizeof(set_tport);
                memcpy(nfp_action, &set_tport, act_size);
                *a_len += act_size;
        }

        return 0;
}

static int
nfp_flower_loop_action(const struct tc_action *a,
                       struct nfp_fl_payload *nfp_fl, int *a_len,
                       struct net_device *netdev,
                       enum nfp_flower_tun_type *tun_type, int *tun_out_cnt)
{
        struct nfp_fl_pre_tunnel *pre_tun;
        struct nfp_fl_set_vxlan *s_vxl;
        struct nfp_fl_push_vlan *psh_v;
        struct nfp_fl_pop_vlan *pop_v;
        struct nfp_fl_output *output;
        int err;

        if (is_tcf_gact_shot(a)) {
                nfp_fl->meta.shortcut = cpu_to_be32(NFP_FL_SC_ACT_DROP);
        } else if (is_tcf_mirred_egress_redirect(a)) {
                if (*a_len + sizeof(struct nfp_fl_output) > NFP_FL_MAX_A_SIZ)
                        return -EOPNOTSUPP;

                output = (struct nfp_fl_output *)&nfp_fl->action_data[*a_len];
                err = nfp_fl_output(output, a, nfp_fl, true, netdev, *tun_type,
                                    tun_out_cnt);
                if (err)
                        return err;

                *a_len += sizeof(struct nfp_fl_output);
        } else if (is_tcf_mirred_egress_mirror(a)) {
                if (*a_len + sizeof(struct nfp_fl_output) > NFP_FL_MAX_A_SIZ)
                        return -EOPNOTSUPP;

                output = (struct nfp_fl_output *)&nfp_fl->action_data[*a_len];
                err = nfp_fl_output(output, a, nfp_fl, false, netdev, *tun_type,
                                    tun_out_cnt);
                if (err)
                        return err;

                *a_len += sizeof(struct nfp_fl_output);
        } else if (is_tcf_vlan(a) && tcf_vlan_action(a) == TCA_VLAN_ACT_POP) {
                if (*a_len + sizeof(struct nfp_fl_pop_vlan) > NFP_FL_MAX_A_SIZ)
                        return -EOPNOTSUPP;

                pop_v = (struct nfp_fl_pop_vlan *)&nfp_fl->action_data[*a_len];
                nfp_fl->meta.shortcut = cpu_to_be32(NFP_FL_SC_ACT_POPV);

                nfp_fl_pop_vlan(pop_v);
                *a_len += sizeof(struct nfp_fl_pop_vlan);
        } else if (is_tcf_vlan(a) && tcf_vlan_action(a) == TCA_VLAN_ACT_PUSH) {
                if (*a_len + sizeof(struct nfp_fl_push_vlan) > NFP_FL_MAX_A_SIZ)
                        return -EOPNOTSUPP;

                psh_v = (struct nfp_fl_push_vlan *)&nfp_fl->action_data[*a_len];
                nfp_fl->meta.shortcut = cpu_to_be32(NFP_FL_SC_ACT_NULL);

                nfp_fl_push_vlan(psh_v, a);
                *a_len += sizeof(struct nfp_fl_push_vlan);
        } else if (is_tcf_tunnel_set(a) && nfp_fl_supported_tun_port(a)) {
                /* Pre-tunnel action is required for tunnel encap.
                 * This checks for next hop entries on NFP.
                 * If none, the packet falls back before applying other actions.
                 */
                if (*a_len + sizeof(struct nfp_fl_pre_tunnel) +
                    sizeof(struct nfp_fl_set_vxlan) > NFP_FL_MAX_A_SIZ)
                        return -EOPNOTSUPP;

                *tun_type = NFP_FL_TUNNEL_VXLAN;
                pre_tun = nfp_fl_pre_tunnel(nfp_fl->action_data, *a_len);
                nfp_fl->meta.shortcut = cpu_to_be32(NFP_FL_SC_ACT_NULL);
                *a_len += sizeof(struct nfp_fl_pre_tunnel);

                s_vxl = (struct nfp_fl_set_vxlan *)&nfp_fl->action_data[*a_len];
                err = nfp_fl_set_vxlan(s_vxl, a, pre_tun);
                if (err)
                        return err;

                *a_len += sizeof(struct nfp_fl_set_vxlan);
        } else if (is_tcf_tunnel_release(a)) {
                /* Tunnel decap is handled by default so accept action. */
                return 0;
        } else if (is_tcf_pedit(a)) {
                if (nfp_fl_pedit(a, &nfp_fl->action_data[*a_len], a_len))
                        return -EOPNOTSUPP;
        } else {
                /* Currently we do not handle any other actions. */
                return -EOPNOTSUPP;
        }

        return 0;
}

int nfp_flower_compile_action(struct tc_cls_flower_offload *flow,
                              struct net_device *netdev,
                              struct nfp_fl_payload *nfp_flow)
{
        int act_len, act_cnt, err, tun_out_cnt;
        enum nfp_flower_tun_type tun_type;
        const struct tc_action *a;
        LIST_HEAD(actions);

        memset(nfp_flow->action_data, 0, NFP_FL_MAX_A_SIZ);
        nfp_flow->meta.act_len = 0;
        tun_type = NFP_FL_TUNNEL_NONE;
        act_len = 0;
        act_cnt = 0;
        tun_out_cnt = 0;

        tcf_exts_to_list(flow->exts, &actions);
        list_for_each_entry(a, &actions, list) {
                err = nfp_flower_loop_action(a, nfp_flow, &act_len, netdev,
                                             &tun_type, &tun_out_cnt);
                if (err)
                        return err;
                act_cnt++;
        }

        /* We optimise when the action list is small, this can unfortunately
         * not happen once we have more than one action in the action list.
         */
        if (act_cnt > 1)
                nfp_flow->meta.shortcut = cpu_to_be32(NFP_FL_SC_ACT_NULL);

        nfp_flow->meta.act_len = act_len;

        return 0;
}