/*
 * 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/fib/fib_table.h>
#include <vnet/fib/fib_entry.h>
#include <vnet/fib/ip4_fib.h>

/*
 * A table of prefixes to be added to tables and the sources for them
 */
typedef struct ip4_fib_table_special_prefix_t_ {
    fib_prefix_t ift_prefix;
    fib_source_t ift_source;
    fib_entry_flag_t ift_flag;
} ip4_fib_table_special_prefix_t;

static const ip4_fib_table_special_prefix_t ip4_specials[] = {
    {
	/* 0.0.0.0/0*/
	.ift_prefix = {
	    .fp_addr = {
		.ip4.data_u32 = 0,
	    },
	    .fp_len  = 0,
	    .fp_proto = FIB_PROTOCOL_IP4,
	},
	.ift_source = FIB_SOURCE_DEFAULT_ROUTE,
	.ift_flag   = FIB_ENTRY_FLAG_DROP,
    },
    {
	/* 0.0.0.0/32*/
	.ift_prefix = {
	    .fp_addr = {
		.ip4.data_u32 = 0,
	    },
	    .fp_len  = 32,
	    .fp_proto = FIB_PROTOCOL_IP4,
	},
	.ift_source = FIB_SOURCE_DEFAULT_ROUTE,
	.ift_flag   = FIB_ENTRY_FLAG_DROP,
    },
    {
	/*
	 * 240.0.0.0/4
	 * drop class E
	 */
	.ift_prefix = {
	    .fp_addr = {
		.ip4.data_u32 = 0xf0000000,
	    },
	    .fp_len   = 4,
	    .fp_proto = FIB_PROTOCOL_IP4,
	},
	.ift_source = FIB_SOURCE_SPECIAL,
	.ift_flag   = FIB_ENTRY_FLAG_DROP,

    },
    {
	/*
	 * 224.0.0.0/4
	 * drop all mcast
	 */
	.ift_prefix = {
	    .fp_addr = {
		.ip4.data_u32 = 0xe0000000,
	    },
	    .fp_len   = 4,
	    .fp_proto = FIB_PROTOCOL_IP4,
	},
	.ift_source = FIB_SOURCE_SPECIAL,
	.ift_flag    = FIB_ENTRY_FLAG_DROP,
    },
    {
	/*
	 * 255.255.255.255/32
	 * drop, but we'll allow it to be usurped by the likes of DHCP
	 */
	.ift_prefix = {
	    .fp_addr = {
		.ip4.data_u32 = 0xffffffff,
	    },
	    .fp_len   = 32,
	    .fp_proto = FIB_PROTOCOL_IP4,
	},
	.ift_source = FIB_SOURCE_DEFAULT_ROUTE,
	.ift_flag   = FIB_ENTRY_FLAG_DROP,
    }
};

void
ip4_fib_hash_load_specials (u32 fib_index)
{
    /*
     * add the special entries into the new FIB
     */
    int ii;

    for (ii = 0; ii < ARRAY_LEN(ip4_specials); ii++)
    {
	fib_prefix_t prefix = ip4_specials[ii].ift_prefix;

	prefix.fp_addr.ip4.data_u32 =
	    clib_host_to_net_u32(prefix.fp_addr.ip4.data_u32);

	fib_table_entry_special_add(fib_index,
				    &prefix,
				    ip4_specials[ii].ift_source,
				    ip4_specials[ii].ift_flag);
    }
}

void
ip4_fib_hash_flush_specials (u32 fib_index)
{
    int ii;

    /*
     * remove all the specials we added when the table was created.
     * In reverse order so the default route is last.
     */
    for (ii = ARRAY_LEN(ip4_specials) - 1; ii >= 0; ii--)
    {
	fib_prefix_t prefix = ip4_specials[ii].ift_prefix;

	prefix.fp_addr.ip4.data_u32 =
	    clib_host_to_net_u32(prefix.fp_addr.ip4.data_u32);

	fib_table_entry_special_remove(fib_index,
				       &prefix,
				       ip4_specials[ii].ift_source);
    }
}

static u32
ip4_create_fib_with_table_id (u32 table_id,
                              fib_source_t src)
{
    fib_table_t *fib_table;
    ip4_fib_t *v4_fib;

    pool_get(ip4_main.fibs, fib_table);
    clib_memset(fib_table, 0, sizeof(*fib_table));

    pool_get_aligned(ip4_fibs, v4_fib, CLIB_CACHE_LINE_BYTES);

    fib_table->ft_proto = FIB_PROTOCOL_IP4;
    fib_table->ft_index = (v4_fib - ip4_fibs);

    /*
     * It is required that the index of the fib_table_t in its pool
     * is the same as the index of the ip4_fib_t in its pool, since the
     * rest of the code usues the 'fib_index' to mean either of these
     * objects, depending on the context.
     */
    ASSERT(fib_table->ft_index == fib_table - ip4_main.fibs);

    hash_set (ip4_main.fib_index_by_table_id, table_id, fib_table->ft_index);

    fib_table->ft_table_id =
	v4_fib->hash.table_id =
	    table_id;
    fib_table->ft_flow_hash_config = IP_FLOW_HASH_DEFAULT;

    fib_table_lock(fib_table->ft_index, FIB_PROTOCOL_IP4, src);

    ip4_fib_table_init(v4_fib);

    /*
     * add the special entries into the new FIB
     */
    ip4_fib_hash_load_specials(fib_table - ip4_main.fibs);

    return (fib_table->ft_index);
}

void
ip4_fib_table_destroy (u32 fib_index)
{
    fib_table_t *fib_table = pool_elt_at_index(ip4_main.fibs, fib_index);
    ip4_fib_t *v4_fib = pool_elt_at_index(ip4_fibs, fib_table->ft_index);
    u32 *n_locks;

    /*
     * remove all the specials we added when the table was created.
     * In reverse order so the default route is last.
     */
    ip4_fib_hash_flush_specials(fib_table - ip4_main.fibs);

    /*
     * validate no more routes.
     */
    fib_table_assert_empty(fib_table);

    vec_foreach(n_locks, fib_table->ft_src_route_counts)
    {
	ASSERT(0 == *n_locks);
    }

    if (~0 != fib_table->ft_table_id)
    {
	hash_unset (ip4_main.fib_index_by_table_id, fib_table->ft_table_id);
    }

    vec_free (fib_table->ft_locks);
    vec_free(fib_table->ft_src_route_counts);
    ip4_fib_table_free(v4_fib);

    pool_put(ip4_fibs, v4_fib);
    pool_put(ip4_main.fibs, fib_table);
}


u32
ip4_fib_table_find_or_create_and_lock (u32 table_id,
                                       fib_source_t src)
{
    u32 index;

    index = ip4_fib_index_from_table_id(table_id);
    if (~0 == index)
	return ip4_create_fib_with_table_id(table_id, src);

    fib_table_lock(index, FIB_PROTOCOL_IP4, src);

    return (index);
}

u32
ip4_fib_table_create_and_lock (fib_source_t src)
{
    return (ip4_create_fib_with_table_id(~0, src));
}

u32
ip4_fib_table_get_index_for_sw_if_index (u32 sw_if_index)
{
    if (sw_if_index >= vec_len(ip4_main.fib_index_by_sw_if_index))
    {
	/*
	 * This is the case for interfaces that are not yet mapped to
	 * a IP table
	 */
	return (~0);
    }
    return (ip4_main.fib_index_by_sw_if_index[sw_if_index]);
}


/**
 * Walk show context
 */
typedef struct ip4_fib_show_walk_ctx_t_
{
    fib_node_index_t *ifsw_indicies;
} ip4_fib_show_walk_ctx_t;

static fib_table_walk_rc_t
ip4_fib_show_walk_cb (fib_node_index_t fib_entry_index,
                      void *arg)
{
    ip4_fib_show_walk_ctx_t *ctx = arg;

    vec_add1(ctx->ifsw_indicies, fib_entry_index);

    return (FIB_TABLE_WALK_CONTINUE);
}

static void
ip4_fib_table_show_all (ip4_fib_t *fib,
			vlib_main_t * vm)
{
    ip4_fib_show_walk_ctx_t ctx = {
        .ifsw_indicies = NULL,
    };
    fib_node_index_t *fib_entry_index;

    ip4_fib_table_walk(fib, ip4_fib_show_walk_cb, &ctx);
    vec_sort_with_function(ctx.ifsw_indicies,
                           fib_entry_cmp_for_sort);

    vec_foreach(fib_entry_index, ctx.ifsw_indicies)
    {
	vlib_cli_output(vm, "%U",
                        format_fib_entry,
                        *fib_entry_index,
                        FIB_ENTRY_FORMAT_BRIEF);
    }

    vec_free(ctx.ifsw_indicies);
}

static void
ip4_fib_table_show_one (ip4_fib_t *fib,
			vlib_main_t * vm,
			ip4_address_t *address,
			u32 mask_len,
                        int detail)
{
    vlib_cli_output(vm, "%U",
                    format_fib_entry,
                    ip4_fib_table_lookup(fib, address, mask_len),
                    (detail ?
                     FIB_ENTRY_FORMAT_DETAIL2 :
                     FIB_ENTRY_FORMAT_DETAIL));
}

u8 *
format_ip4_fib_table_memory (u8 * s, va_list * args)
{
    s = format(s, "%=30s %=6d\n",
               "IPv4 unicast",
               pool_elts(ip4_main.fibs));
    return (s);
}

static clib_error_t *
ip4_show_fib (vlib_main_t * vm,
	      unformat_input_t * input,
	      vlib_cli_command_t * cmd)
{
    ip4_main_t * im4 = &ip4_main;
    u64 total_mtrie_memory, total_hash_memory;
    int verbose, matching, mtrie, memory;
    ip4_address_t matching_address;
    u32 fib_index, matching_mask = 32;
    int i, table_id = -1, user_fib_index = ~0;
    int detail = 0;

    verbose = 1;
    matching = mtrie = memory = 0;
    total_hash_memory = total_mtrie_memory = 0;

    while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
	if (unformat (input, "brief") || unformat (input, "summary")
	    || unformat (input, "sum"))
	    verbose = 0;

	else if (unformat (input, "detail") || unformat (input, "det"))
	    detail = 1;

	else if (unformat (input, "mtrie"))
	    mtrie = 1;

        else if (unformat (input, "mem") ||
                 unformat (input, "memory"))
	    memory = 1;

	else if (unformat (input, "%U/%d",
			   unformat_ip4_address, &matching_address, &matching_mask))
	    matching = 1;

	else if (unformat (input, "%U", unformat_ip4_address, &matching_address))
	    matching = 1;

	else if (unformat (input, "table %d", &table_id))
	    ;
	else if (unformat (input, "index %d", &user_fib_index))
	    ;
	else
	    break;
    }

    pool_foreach_index (fib_index, im4->fibs)
     {
	fib_table_t *fib_table = pool_elt_at_index(im4->fibs, fib_index);
	ip4_fib_t *fib = pool_elt_at_index(ip4_fibs, fib_table->ft_index);
        fib_source_t source;
        u8 *s = NULL;

	if (table_id >= 0 && table_id != (int)fib->hash.table_id)
	    continue;
	if (user_fib_index != ~0 && user_fib_index != fib_index)
	    continue;

        if (memory)
        {
            uword mtrie_size, hash_size;


            mtrie_size = ip4_mtrie_memory_usage(&fib->mtrie);
            hash_size = 0;

	    for (i = 0; i < ARRAY_LEN (fib->hash.fib_entry_by_dst_address); i++)
	    {
		uword * hash = fib->hash.fib_entry_by_dst_address[i];
                if (NULL != hash)
                {
                    hash_size += hash_bytes(hash);
                }
            }

            if (verbose)
                vlib_cli_output (vm, "%U mtrie:%d hash:%d",
                                 format_fib_table_name, fib_index,
                                 FIB_PROTOCOL_IP4,
                                 mtrie_size,
                                 hash_size);
            total_mtrie_memory += mtrie_size;
            total_hash_memory += hash_size;
            continue;
        }

	s = format(s, "%U, fib_index:%d, flow hash:[%U] epoch:%d flags:%U locks:[",
                   format_fib_table_name, fib_index,
                   FIB_PROTOCOL_IP4,
                   fib_index,
                   format_ip_flow_hash_config,
                   fib_table->ft_flow_hash_config,
                   fib_table->ft_epoch,
                   format_fib_table_flags, fib_table->ft_flags);
        vec_foreach_index(source, fib_table->ft_locks)
        {
            if (0 != fib_table->ft_locks[source])
            {
                s = format(s, "%U:%d, ",
                           format_fib_source, source,
                           fib_table->ft_locks[source]);
            }
        }
        s = format (s, "]");
        vlib_cli_output (vm, "%v", s);
        vec_free(s);

	/* Show summary? */
	if (mtrie)
        {
	    vlib_cli_output (vm, "%U", format_ip4_mtrie, &fib->mtrie, verbose);
            continue;
        }
	if (! verbose)
	{
	    vlib_cli_output (vm, "%=20s%=16s", "Prefix length", "Count");
	    for (i = 0; i < ARRAY_LEN (fib->hash.fib_entry_by_dst_address); i++)
	    {
		uword * hash = fib->hash.fib_entry_by_dst_address[i];
		uword n_elts = hash_elts (hash);
		if (n_elts > 0)
		    vlib_cli_output (vm, "%20d%16d", i, n_elts);
	    }
	    continue;
	}

	if (!matching)
	{
	    ip4_fib_table_show_all(fib, vm);
	}
	else
	{
	    ip4_fib_table_show_one(fib, vm, &matching_address,
                                   matching_mask, detail);
	}
    }

    if (memory)
    {
        vlib_cli_output (vm, "totals: mtrie:%ld hash:%ld all:%ld",
                         total_mtrie_memory,
                         total_hash_memory,
                         total_mtrie_memory + total_hash_memory);
    }
    return 0;
}

/*?
 * This command displays the IPv4 FIB Tables (VRF Tables) and the route
 * entries for each table.
 *
 * @note This command will run for a long time when the FIB tables are
 * comprised of millions of entries. For those scenarios, consider displaying
 * a single table or summary mode.
 *
 * @cliexpar
 * Example of how to display all the IPv4 FIB tables:
 * @cliexstart{show ip fib}
 * ipv4-VRF:0, fib_index 0, flow hash: src dst sport dport proto
 * 0.0.0.0/0
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:0 buckets:1 uRPF:0 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * 0.0.0.0/32
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:1 buckets:1 uRPF:1 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * 6.0.1.2/32
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:30 buckets:1 uRPF:29 to:[0:0]]
 *     [0] [@3]: arp-ipv4: via 6.0.0.1 af_packet0
 * 7.0.0.1/32
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:31 buckets:4 uRPF:30 to:[0:0]]
 *     [0] [@3]: arp-ipv4: via 6.0.0.2 af_packet0
 *     [1] [@3]: arp-ipv4: via 6.0.0.2 af_packet0
 *     [2] [@3]: arp-ipv4: via 6.0.0.2 af_packet0
 *     [3] [@3]: arp-ipv4: via 6.0.0.1 af_packet0
 * 224.0.0.0/8
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:3 buckets:1 uRPF:3 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * 240.0.0.0/8
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:2 buckets:1 uRPF:2 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * 255.255.255.255/32
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:4 buckets:1 uRPF:4 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * ipv4-VRF:7, fib_index 1, flow hash: src dst sport dport proto
 * 0.0.0.0/0
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:12 buckets:1 uRPF:11 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * 0.0.0.0/32
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:13 buckets:1 uRPF:12 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * 172.16.1.0/24
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:17 buckets:1 uRPF:16 to:[0:0]]
 *     [0] [@4]: ipv4-glean: af_packet0
 * 172.16.1.1/32
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:18 buckets:1 uRPF:17 to:[1:84]]
 *     [0] [@2]: dpo-receive: 172.16.1.1 on af_packet0
 * 172.16.1.2/32
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:21 buckets:1 uRPF:20 to:[0:0]]
 *     [0] [@5]: ipv4 via 172.16.1.2 af_packet0: IP4: 02:fe:9e:70:7a:2b -> 26:a5:f6:9c:3a:36
 * 172.16.2.0/24
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:19 buckets:1 uRPF:18 to:[0:0]]
 *     [0] [@4]: ipv4-glean: af_packet1
 * 172.16.2.1/32
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:20 buckets:1 uRPF:19 to:[0:0]]
 *     [0] [@2]: dpo-receive: 172.16.2.1 on af_packet1
 * 224.0.0.0/8
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:15 buckets:1 uRPF:14 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * 240.0.0.0/8
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:14 buckets:1 uRPF:13 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * 255.255.255.255/32
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:16 buckets:1 uRPF:15 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * @cliexend
 * Example of how to display a single IPv4 FIB table:
 * @cliexstart{show ip fib table 7}
 * ipv4-VRF:7, fib_index 1, flow hash: src dst sport dport proto
 * 0.0.0.0/0
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:12 buckets:1 uRPF:11 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * 0.0.0.0/32
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:13 buckets:1 uRPF:12 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * 172.16.1.0/24
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:17 buckets:1 uRPF:16 to:[0:0]]
 *     [0] [@4]: ipv4-glean: af_packet0
 * 172.16.1.1/32
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:18 buckets:1 uRPF:17 to:[1:84]]
 *     [0] [@2]: dpo-receive: 172.16.1.1 on af_packet0
 * 172.16.1.2/32
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:21 buckets:1 uRPF:20 to:[0:0]]
 *     [0] [@5]: ipv4 via 172.16.1.2 af_packet0: IP4: 02:fe:9e:70:7a:2b -> 26:a5:f6:9c:3a:36
 * 172.16.2.0/24
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:19 buckets:1 uRPF:18 to:[0:0]]
 *     [0] [@4]: ipv4-glean: af_packet1
 * 172.16.2.1/32
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:20 buckets:1 uRPF:19 to:[0:0]]
 *     [0] [@2]: dpo-receive: 172.16.2.1 on af_packet1
 * 224.0.0.0/8
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:15 buckets:1 uRPF:14 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * 240.0.0.0/8
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:14 buckets:1 uRPF:13 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * 255.255.255.255/32
 *   unicast-ip4-chain
 *   [@0]: dpo-load-balance: [index:16 buckets:1 uRPF:15 to:[0:0]]
 *     [0] [@0]: dpo-drop ip6
 * @cliexend
 * Example of how to display a summary of all IPv4 FIB tables:
 * @cliexstart{show ip fib summary}
 * ipv4-VRF:0, fib_index 0, flow hash: src dst sport dport proto
 *     Prefix length         Count
 *                    0               1
 *                    8               2
 *                   32               4
 * ipv4-VRF:7, fib_index 1, flow hash: src dst sport dport proto
 *     Prefix length         Count
 *                    0               1
 *                    8               2
 *                   24               2
 *                   32               4
 * @cliexend
 ?*/
VLIB_CLI_COMMAND (ip4_show_fib_command, static) = {
    .path = "show ip fib",
    .short_help = "show ip fib [summary] [table <table-id>] [index <fib-id>] [<ip4-addr>[/<mask>]] [mtrie] [detail]",
    .function = ip4_show_fib,
};

static clib_error_t *
ip_config (vlib_main_t * vm, unformat_input_t * input)
{
    char *default_name = 0;

    while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
	if (unformat (input, "default-table-name %s", &default_name))
	    ;
	else
	    return clib_error_return (0, "unknown input '%U'",
				      format_unformat_error, input);
    }

    fib_table_default_names[FIB_PROTOCOL_IP4] = default_name;

    return 0;
}

VLIB_EARLY_CONFIG_FUNCTION (ip_config, "ip");