/*
 *------------------------------------------------------------------
 * bier_api.c - vnet BIER api
 *
 * Copyright (c) 2016 Cisco and/or its affiliates.
 * 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 <vnet/vnet.h>
#include <vlibmemory/api.h>

#include <vnet/api_errno.h>
#include <vnet/bier/bier_table.h>
#include <vnet/bier/bier_imp.h>
#include <vnet/bier/bier_disp_table.h>
#include <vnet/bier/bier_disp_entry.h>
#include <vnet/bier/bier_bit_string.h>
#include <vnet/bier/bier_hdr_inlines.h>
#include <vnet/fib/fib_path_list.h>
#include <vnet/fib/fib_api.h>
#include <vnet/fib/fib_table.h>
#include <vnet/mfib/mfib_table.h>

#include <vnet/format_fns.h>
#include <bier/bier.api_enum.h>
#include <bier/bier.api_types.h>

#define REPLY_MSG_ID_BASE bier_main.msg_id_base
#include <vlibapi/api_helper_macros.h>

typedef struct
{
  u16 msg_id_base;
} bier_main_t;

bier_main_t bier_main;

static void
vl_api_bier_table_add_del_t_handler (vl_api_bier_table_add_del_t * mp)
{
    vl_api_bier_table_add_del_reply_t *rmp;
    vnet_main_t *vnm;
    int rv;

    vnm = vnet_get_main ();
    vnm->api_errno = 0;

    if (mp->bt_tbl_id.bt_hdr_len_id >= BIER_HDR_LEN_2048)
    {
        rv = VNET_API_ERROR_BIER_BSL_UNSUP;
    }
    else
    {
        bier_table_id_t bti = {
            .bti_set = mp->bt_tbl_id.bt_set,
            .bti_sub_domain = mp->bt_tbl_id.bt_sub_domain,
            .bti_hdr_len = mp->bt_tbl_id.bt_hdr_len_id,
            .bti_type = BIER_TABLE_MPLS_SPF,
            .bti_ecmp = BIER_ECMP_TABLE_ID_MAIN,
        };

        if (mp->bt_is_add)
        {
            mpls_label_t label = ntohl(mp->bt_label);

            /*
             * convert acceptable 'don't want a label' values from 
             * the API to the correct internal INVLID value
             */
            if ((0 == label) || (~0 == label))
            {
                label = MPLS_LABEL_INVALID;
            }
            bier_table_add_or_lock(&bti, label);
        }
        else
        {
            bier_table_unlock(&bti);
        }

        rv = vnm->api_errno;
    }

    REPLY_MACRO (VL_API_BIER_TABLE_ADD_DEL_REPLY);
}

static void
send_bier_table_details (vl_api_registration_t * reg,
                         u32 context,
                         const bier_table_t *bt)
{
    vl_api_bier_table_details_t *mp;

    mp = vl_msg_api_alloc(sizeof(*mp));
    if (!mp)
        return;
    clib_memset(mp, 0, sizeof(*mp));
    mp->_vl_msg_id = ntohs (REPLY_MSG_ID_BASE + VL_API_BIER_TABLE_DETAILS);
    mp->context = context;

    mp->bt_label = bt->bt_ll;
    mp->bt_tbl_id.bt_set = bt->bt_id.bti_set;
    mp->bt_tbl_id.bt_sub_domain = bt->bt_id.bti_sub_domain;
    mp->bt_tbl_id.bt_hdr_len_id = bt->bt_id.bti_hdr_len;

    vl_api_send_msg (reg, (u8 *) mp);
}

static void
vl_api_bier_table_dump_t_handler (vl_api_bier_table_dump_t * mp)
{
    vl_api_registration_t *reg;
    bier_table_t *bt;

    reg = vl_api_client_index_to_registration (mp->client_index);
    if (!reg)
      return;

    pool_foreach (bt, bier_table_pool)
     {
        /*
         * skip the ecmp tables.
         */
        if (bier_table_is_main(bt))
        {
            send_bier_table_details(reg, mp->context, bt);
        }
    }
}

static void
vl_api_bier_route_add_del_t_handler (vl_api_bier_route_add_del_t * mp)
{
    vl_api_bier_route_add_del_reply_t *rmp;
    fib_route_path_t *brpaths, *brpath;
    vnet_main_t *vnm;
    bier_bp_t bp;
    int rv = 0;
    u8 ii;

    vnm = vnet_get_main ();
    vnm->api_errno = 0;
    bp = ntohl(mp->br_route.br_bp);
    brpaths = NULL;

    if (mp->br_route.br_tbl_id.bt_hdr_len_id >= BIER_HDR_LEN_2048)
    {
        rv = VNET_API_ERROR_BIER_BSL_UNSUP;
        goto done;
    }
    if (0 == bp || bp > BIER_BP_MAX)
    {
        rv = -1;
        goto done;
    }

    bier_table_id_t bti = {
        .bti_set = mp->br_route.br_tbl_id.bt_set,
        .bti_sub_domain = mp->br_route.br_tbl_id.bt_sub_domain,
        .bti_hdr_len = mp->br_route.br_tbl_id.bt_hdr_len_id,
        .bti_type = BIER_TABLE_MPLS_SPF,
        .bti_ecmp = BIER_ECMP_TABLE_ID_MAIN,
    };

    vec_validate(brpaths, mp->br_route.br_n_paths - 1);

    vec_foreach_index(ii, brpaths)
    {
        brpath = &brpaths[ii];
        rv = fib_api_path_decode(&mp->br_route.br_paths[ii], brpath);

        if (0 != rv)
        {
            goto done;
        }
    }

    if (mp->br_is_replace)
    {
        if (0 == vec_len(brpaths))
        {
            bier_table_route_delete(&bti, bp);
        }
        else
        {
            bier_table_route_path_update(&bti, bp, brpaths);
        }
    }
    else if (mp->br_is_add)
    {
        bier_table_route_path_add(&bti, bp, brpaths);
    }
    else
    {
        bier_table_route_path_remove(&bti, bp, brpaths);
    }
    vec_free(brpaths);

done:
    rv = (rv == 0) ? vnm->api_errno : rv;

    REPLY_MACRO (VL_API_BIER_ROUTE_ADD_DEL_REPLY);
}

typedef struct bier_route_details_walk_t_
{
    vl_api_registration_t * reg;
    u32 context;
} bier_route_details_walk_t;

static void
send_bier_route_details (const bier_table_t *bt,
                         const bier_entry_t *be,
                         void *args)
{
    bier_route_details_walk_t *ctx = args;
    vl_api_bier_route_details_t *mp;
    fib_path_encode_ctx_t path_ctx = {
        .rpaths = NULL,
    };
    fib_route_path_t *rpath;
    vl_api_fib_path_t *fp;
    u32 n_paths, m_size;

    n_paths = fib_path_list_get_n_paths(be->be_path_list);
    m_size = sizeof(*mp) + (n_paths * sizeof(vl_api_fib_path_t));
    mp = vl_msg_api_alloc(m_size);
    if (!mp)
        return;

    clib_memset(mp, 0, m_size);
    mp->_vl_msg_id = ntohs (REPLY_MSG_ID_BASE + VL_API_BIER_ROUTE_DETAILS);
    mp->context = ctx->context;

    mp->br_route.br_tbl_id.bt_set = bt->bt_id.bti_set;
    mp->br_route.br_tbl_id.bt_sub_domain = bt->bt_id.bti_sub_domain;
    mp->br_route.br_tbl_id.bt_hdr_len_id = bt->bt_id.bti_hdr_len;
    mp->br_route.br_bp = htonl(be->be_bp);
    mp->br_route.br_n_paths = htonl(n_paths);

    fib_path_list_walk_w_ext(be->be_path_list,
                             NULL,
                             fib_path_encode,
                            &path_ctx);

    fp = mp->br_route.br_paths;
    vec_foreach (rpath, path_ctx.rpaths)
    {
        fib_api_path_encode(rpath, fp);
        fp++;
    }

    vec_free(path_ctx.rpaths);
    vl_api_send_msg (ctx->reg, (u8 *) mp);
}

static void
vl_api_bier_route_dump_t_handler (vl_api_bier_route_dump_t * mp)
{
    vl_api_registration_t *reg;

    reg = vl_api_client_index_to_registration (mp->client_index);
    if (!reg)
      return;

    bier_table_id_t bti = {
        .bti_set = mp->br_tbl_id.bt_set,
        .bti_sub_domain = mp->br_tbl_id.bt_sub_domain,
        .bti_hdr_len = mp->br_tbl_id.bt_hdr_len_id,
        .bti_type = BIER_TABLE_MPLS_SPF,
        .bti_ecmp = BIER_ECMP_TABLE_ID_MAIN,
    };
    bier_route_details_walk_t ctx = {
        .reg = reg,
        .context = mp->context,
    };
    bier_table_walk(&bti, send_bier_route_details, &ctx);
}

static void
vl_api_bier_imp_add_t_handler (vl_api_bier_imp_add_t * mp)
{
    vl_api_bier_imp_add_reply_t *rmp;
    vnet_main_t *vnm;
    index_t bii = ~0;
    int rv = 0;

    vnm = vnet_get_main ();
    vnm->api_errno = 0;

    /*
     * The BSL support by VPP is limited to the size of the
     * available space in the vlib_buffer_t
     */
    if (mp->bi_tbl_id.bt_hdr_len_id >= BIER_HDR_LEN_2048)
    {
        rv = VNET_API_ERROR_BIER_BSL_UNSUP;
    }
    else
    {
        bier_table_id_t bti = {
            .bti_set = mp->bi_tbl_id.bt_set,
            .bti_sub_domain = mp->bi_tbl_id.bt_sub_domain,
            .bti_hdr_len = mp->bi_tbl_id.bt_hdr_len_id,
            .bti_type = BIER_TABLE_MPLS_SPF,
            .bti_ecmp = BIER_ECMP_TABLE_ID_MAIN,
        };
        bier_bit_string_t bs = {
            .bbs_len = mp->bi_n_bytes,
            .bbs_buckets = mp->bi_bytes,
        };

        bii = bier_imp_add_or_lock(&bti, ntohs(mp->bi_src), &bs);
    }

    REPLY_MACRO2 (VL_API_BIER_IMP_ADD_REPLY,
    ({
        rmp->bi_index = ntohl (bii);
    }));
}

static void
vl_api_bier_imp_del_t_handler (vl_api_bier_imp_del_t * mp)
{
    vl_api_bier_imp_del_reply_t *rmp;
    vnet_main_t *vnm;
    int rv = 0;

    vnm = vnet_get_main ();
    vnm->api_errno = 0;

    bier_imp_unlock(ntohl(mp->bi_index));

    REPLY_MACRO(VL_API_BIER_IMP_DEL_REPLY);
}

static void
send_bier_imp_details (vl_api_registration_t * reg,
                       u32 context,
                       const bier_imp_t *bi)
{
    vl_api_bier_imp_details_t *mp;
    bier_hdr_t copy;
    u8 n_bytes;

    copy = bi->bi_hdr;
    bier_hdr_ntoh(&copy);

    n_bytes = bier_hdr_len_id_to_num_bytes(
                  bier_hdr_get_len_id(&copy));
    mp = vl_msg_api_alloc(sizeof(*mp) + n_bytes);
    if (!mp)
        return;
    clib_memset(mp, 0, sizeof(*mp)+n_bytes);
    mp->_vl_msg_id = ntohs (REPLY_MSG_ID_BASE + VL_API_BIER_IMP_DETAILS);
    mp->context = context;

    mp->bi_tbl_id.bt_set = bi->bi_tbl.bti_set;
    mp->bi_tbl_id.bt_sub_domain = bi->bi_tbl.bti_sub_domain;
    mp->bi_tbl_id.bt_hdr_len_id = bi->bi_tbl.bti_hdr_len;

    mp->bi_src = htons(bier_hdr_get_src_id(&copy));
    mp->bi_n_bytes = n_bytes;
    memcpy(mp->bi_bytes, bi->bi_bits, n_bytes);

    vl_api_send_msg (reg, (u8 *) mp);
}

static void
vl_api_bier_imp_dump_t_handler (vl_api_bier_imp_dump_t * mp)
{
    vl_api_registration_t *reg;
    bier_imp_t *bi;

    reg = vl_api_client_index_to_registration (mp->client_index);
    if (!reg)
      return;

    pool_foreach (bi, bier_imp_pool)
     {
        send_bier_imp_details(reg, mp->context, bi);
    }
}

static void
vl_api_bier_disp_table_add_del_t_handler (vl_api_bier_disp_table_add_del_t * mp)
{
    vl_api_bier_disp_table_add_del_reply_t *rmp;
    vnet_main_t *vnm;
    u32 table_id;
    int rv;

    vnm = vnet_get_main ();
    vnm->api_errno = 0;
    table_id = ntohl(mp->bdt_tbl_id);

    if (mp->bdt_is_add)
    {
        bier_disp_table_add_or_lock(table_id);
    }
    else
    {
        bier_disp_table_unlock_w_table_id(table_id);
    }

    rv = vnm->api_errno;

    REPLY_MACRO (VL_API_BIER_DISP_TABLE_ADD_DEL_REPLY);
}

static void
send_bier_disp_table_details (vl_api_registration_t * reg,
                              u32 context,
                              const bier_disp_table_t *bdt)
{
    vl_api_bier_disp_table_details_t *mp;

    mp = vl_msg_api_alloc(sizeof(*mp));
    if (!mp)
        return;
    clib_memset(mp, 0, sizeof(*mp));
    mp->_vl_msg_id =
      ntohs (REPLY_MSG_ID_BASE + VL_API_BIER_DISP_TABLE_DETAILS);
    mp->context = context;

    mp->bdt_tbl_id = htonl(bdt->bdt_table_id);

    vl_api_send_msg (reg, (u8 *) mp);
}

static void
vl_api_bier_disp_table_dump_t_handler (vl_api_bier_disp_table_dump_t * mp)
{
    vl_api_registration_t *reg;
    bier_disp_table_t *bdt;

    reg = vl_api_client_index_to_registration (mp->client_index);
    if (!reg)
      return;

    pool_foreach (bdt, bier_disp_table_pool)
     {
        send_bier_disp_table_details(reg, mp->context, bdt);
    }
}

static void
vl_api_bier_disp_entry_add_del_t_handler (vl_api_bier_disp_entry_add_del_t * mp)
{
    vl_api_bier_disp_entry_add_del_reply_t *rmp;
    fib_route_path_t *brps = NULL, *brp;
    vnet_main_t *vnm;
    bier_bp_t bp;
    u32 table_id;
    int rv = 0;
    u32 ii;

    vnm = vnet_get_main ();
    vnm->api_errno = 0;
    table_id = ntohl(mp->bde_tbl_id);
    bp = ntohs(mp->bde_bp);

    /*
     * BP=0 is the default route
     */
    if (bp > 0xffff)
    {
        rv = -1;
        goto done;
    }

    vec_validate(brps, mp->bde_n_paths - 1);
    vec_foreach_index(ii, brps)
    {
        brp = &brps[ii];
        brp->frp_fib_index = ntohl(mp->bde_paths[ii].table_id);
        brp->frp_sw_if_index = ntohl(mp->bde_paths[ii].sw_if_index);

        if (~0 != ntohl(mp->bde_paths[ii].rpf_id))
        {
            brp->frp_flags = FIB_ROUTE_PATH_RPF_ID;
            brp->frp_rpf_id = ntohl(mp->bde_paths[ii].rpf_id);
        }

        if (FIB_API_PATH_NH_PROTO_IP4 == mp->bde_paths[ii].proto)
        {
            clib_memcpy (&brp->frp_addr.ip4,
                         &mp->bde_paths[ii].nh.address.ip4,
                         sizeof (brp->frp_addr.ip4));
        }
        else if (FIB_API_PATH_NH_PROTO_IP6 == mp->bde_paths[ii].proto)
        {
            clib_memcpy (&brp->frp_addr.ip6,
                         &mp->bde_paths[ii].nh.address.ip6,
                         sizeof (brp->frp_addr.ip6));
        }
        if (ip46_address_is_zero(&brp->frp_addr))
        {
            index_t fti;

            switch (mp->bde_payload_proto)
            {
            case BIER_HDR_PROTO_INVALID:
            case BIER_HDR_PROTO_MPLS_DOWN_STREAM:
            case BIER_HDR_PROTO_MPLS_UP_STREAM:
            case BIER_HDR_PROTO_ETHERNET:
            case BIER_HDR_PROTO_VXLAN:
            case BIER_HDR_PROTO_CTRL:
            case BIER_HDR_PROTO_OAM:
                rv = VNET_API_ERROR_UNSUPPORTED;
                goto done;
                break;
            case BIER_HDR_PROTO_IPV4:
            case BIER_HDR_PROTO_IPV6:
            {
                fib_protocol_t fproto;

                fproto = (mp->bde_payload_proto == BIER_HDR_PROTO_IPV4 ?
                          FIB_PROTOCOL_IP4 :
                          FIB_PROTOCOL_IP6);

                if (brp->frp_flags & FIB_ROUTE_PATH_RPF_ID)
                {
                    fti = mfib_table_find (fproto,
                                           ntohl (mp->bde_paths[ii].table_id));
                }
                else
                {
                    fti = fib_table_find (fproto,
                                          ntohl (mp->bde_paths[ii].table_id));
                }

                if (INDEX_INVALID != fti)
                {
                    brp->frp_fib_index = fti;
                }
                else
                {
                    rv = VNET_API_ERROR_NO_SUCH_FIB;
                    goto done;
                }
                break;
            }
            }
        }
    }

    if (mp->bde_is_add)
    {
        bier_disp_table_entry_path_add(table_id, bp,
                                       mp->bde_payload_proto,
                                       brps);
    }
    else
    {
        bier_disp_table_entry_path_remove(table_id, bp,
                                          mp->bde_payload_proto,
                                          brps);
    }

done:
    vec_free(brps);
    rv = (rv == 0) ? vnm->api_errno : rv;

    REPLY_MACRO (VL_API_BIER_DISP_ENTRY_ADD_DEL_REPLY);
}

typedef struct bier_disp_entry_details_walk_t_
{
    vl_api_registration_t * reg;
    u32 context;
} bier_disp_entry_details_walk_t;

static void
send_bier_disp_entry_details (const bier_disp_table_t *bdt,
                              const bier_disp_entry_t *bde,
                              u16 bp,
                              void *args)
{
    bier_disp_entry_details_walk_t *ctx = args;
    vl_api_bier_disp_entry_details_t *mp;
    bier_hdr_proto_id_t pproto;
    vl_api_fib_path_t *fp;
    u32 n_paths, m_size;

    FOR_EACH_BIER_HDR_PROTO(pproto)
    {
        fib_node_index_t pl = bde->bde_pl[pproto];

        if (INDEX_INVALID != pl)
        {
            fib_path_encode_ctx_t path_ctx = {
                .rpaths = NULL,
            };
            fib_route_path_t *rpath;

            n_paths = fib_path_list_get_n_paths(pl);
            m_size = sizeof(*mp) + (n_paths * sizeof(vl_api_fib_path_t));
            mp = vl_msg_api_alloc(m_size);
            if (!mp)
                return;

            clib_memset(mp, 0, m_size);
	    mp->_vl_msg_id =
	      ntohs (REPLY_MSG_ID_BASE + VL_API_BIER_DISP_ENTRY_DETAILS);
	    mp->context = ctx->context;

	    mp->bde_tbl_id = htonl (bdt->bdt_table_id);
	    mp->bde_n_paths = htonl (n_paths);
	    mp->bde_payload_proto = pproto;
	    mp->bde_bp = htons (bp);

	    fib_path_list_walk_w_ext (pl, NULL, fib_path_encode, &path_ctx);

	    fp = mp->bde_paths;
	    vec_foreach (rpath, path_ctx.rpaths)
	      {
		fib_api_path_encode (rpath, fp);
		fp++;
	      }

	    vl_api_send_msg (ctx->reg, (u8 *) mp);
	    vec_free (path_ctx.rpaths);
	}
    }
}

static void
vl_api_bier_disp_entry_dump_t_handler (vl_api_bier_disp_entry_dump_t * mp)
{
    vl_api_registration_t *reg;

    reg = vl_api_client_index_to_registration (mp->client_index);
    if (!reg)
      return;

    bier_disp_entry_details_walk_t ctx = {
        .reg = reg,
        .context = mp->context,
    };
    bier_disp_table_walk(ntohl(mp->bde_tbl_id),
                         send_bier_disp_entry_details,
                         &ctx);
}

#include <bier/bier.api.c>

static clib_error_t *
bier_api_hookup (vlib_main_t * vm)
{
  bier_main.msg_id_base = setup_message_id_table ();

  return 0;
}

VLIB_API_INIT_FUNCTION (bier_api_hookup);