/* Configuration generator.
 * Copyright (C) 2000 Kunihiro Ishiguro
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * GNU Zebra is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <zebra.h>

#include "command.h"
#include "linklist.h"
#include "memory.h"
#include "typesafe.h"

#include "vtysh/vtysh.h"
#include "vtysh/vtysh_user.h"

DEFINE_MGROUP(MVTYSH, "vtysh");
DEFINE_MTYPE_STATIC(MVTYSH, VTYSH_CONFIG, "Vtysh configuration");
DEFINE_MTYPE_STATIC(MVTYSH, VTYSH_CONFIG_LINE, "Vtysh configuration line");

vector configvec;

PREDECL_LIST(config_master);
PREDECL_HASH(config_master_hash);

struct config {
	/* Configuration node name. */
	char *name;

	/* Configuration string line. */
	struct list *line;

	/* Configuration can be nested. */
	struct config *parent;
	vector nested;

	/* Exit command. */
	char *exit;

	/* Index of this config. */
	uint32_t index;

	/* Node entry for the typed Red-black tree */
	struct config_master_item rbt_item;
	struct config_master_hash_item hash_item;
};

struct list *config_top;

static int line_cmp(char *c1, char *c2)
{
	return strcmp(c1, c2);
}

static void line_del(char *line)
{
	XFREE(MTYPE_VTYSH_CONFIG_LINE, line);
}

static struct config *config_new(void)
{
	struct config *config;
	config = XCALLOC(MTYPE_VTYSH_CONFIG, sizeof(struct config));
	return config;
}

static void config_del(struct config *config)
{
	vector_free(config->nested);
	list_delete(&config->line);
	if (config->exit)
		XFREE(MTYPE_VTYSH_CONFIG_LINE, config->exit);
	XFREE(MTYPE_VTYSH_CONFIG_LINE, config->name);
	XFREE(MTYPE_VTYSH_CONFIG, config);
}

static int config_cmp(const struct config *c1, const struct config *c2)
{
	return strcmp(c1->name, c2->name);
}

static uint32_t config_hash(const struct config *c)
{
	return string_hash_make(c->name);
}

DECLARE_LIST(config_master, struct config, rbt_item);
DECLARE_HASH(config_master_hash, struct config, hash_item, config_cmp,
	     config_hash);

/*
 * The config_master_head is a list for order of receipt
 * The hash is for quick lookup under this NODE
 */
struct configuration {
	struct config_master_head master;
	struct config_master_hash_head hash_master;
};

static struct config *config_get_vec(vector vec, int index, const char *line)
{
	struct config *config, *config_loop;
	struct configuration *configuration;
	struct config lookup;

	config = config_loop = NULL;

	configuration = vector_lookup_ensure(vec, index);

	if (!configuration) {
		configuration = XMALLOC(MTYPE_VTYSH_CONFIG,
					sizeof(struct configuration));
		config_master_init(&configuration->master);
		config_master_hash_init(&configuration->hash_master);
		vector_set_index(vec, index, configuration);
	}

	lookup.name = (char *)line;
	config = config_master_hash_find(&configuration->hash_master, &lookup);

	if (!config) {
		config = config_new();
		config->line = list_new();
		config->line->del = (void (*)(void *))line_del;
		config->line->cmp = (int (*)(void *, void *))line_cmp;
		config->name = XSTRDUP(MTYPE_VTYSH_CONFIG_LINE, line);
		config->exit = NULL;
		config->index = index;
		config->nested = vector_init(1);
		config_master_add_tail(&configuration->master, config);
		config_master_hash_add(&configuration->hash_master, config);
	}
	return config;
}

static struct config *config_get(int index, const char *line)
{
	return config_get_vec(configvec, index, line);
}

static struct config *config_get_nested(struct config *parent, int index,
					const char *line)
{
	struct config *config;

	config = config_get_vec(parent->nested, index, line);
	config->parent = parent;

	return config;
}

void config_add_line(struct list *config, const char *line)
{
	listnode_add(config, XSTRDUP(MTYPE_VTYSH_CONFIG_LINE, line));
}

static void config_add_line_uniq(struct list *config, const char *line)
{
	struct listnode *node, *nnode;
	char *pnt;

	for (ALL_LIST_ELEMENTS(config, node, nnode, pnt)) {
		if (strcmp(pnt, line) == 0)
			return;
	}
	listnode_add_sort(config, XSTRDUP(MTYPE_VTYSH_CONFIG_LINE, line));
}

/*
 * Add a line that should only be shown once, and always show at the end of the
 * config block.
 *
 * If the line already exists, it will be moved to the end of the block. If it
 * does not exist, it will be added at the end of the block.
 *
 * Note that this only makes sense when there is just one such line that should
 * show up at the very end of a config block. Furthermore, if the same block
 * can show up from multiple daemons, all of them must make sure to print the
 * line at the end of their config, otherwise the line will show at the end of
 * the config for the last daemon that printed it.
 *
 * Here is a motivating example with the 'exit-vrf' command. Suppose we receive
 * a config from Zebra like so:
 *
 * vrf BLUE
 *    ip route A
 *    ip route B
 *    exit-vrf
 *
 * Then suppose we later receive this config from PIM:
 *
 * vrf BLUE
 *    ip msdp mesh-group MyGroup member 1.2.3.4
 *    exit-vrf
 *
 * Then we will combine them into one config block like so:
 *
 * vrf BLUE
 *    ip route A
 *    ip route B
 *    ip msdp mesh-group MyGroup member 1.2.3.4
 *    exit-vrf
 *
 * Because PIM also sent us an 'exit-vrf', we noticed that we already had one
 * under the 'vrf BLUE' config block and so we moved it to the end of the
 * config block again. If PIM had neglected to send us 'exit-vrf', the result
 * would be this:
 *
 * vrf BLUE
 *    ip route A
 *    ip route B
 *    exit-vrf
 *    ip msdp mesh-group MyGroup member 1.2.3.4
 *
 * Therefore, daemons that share config blocks must take care to consistently
 * print the same block terminators.
 *
 * Ideally this would be solved by adding a string to struct config that is
 * always printed at the end when dumping a config. However, this would only
 * work when the user is using integrated config. In the non-integrated config
 * case, daemons are responsible for writing their own config files, and so the
 * must be able to print these blocks correctly independently of vtysh, which
 * means they are the ones that need to handle printing the block terminators
 * and VTYSH needs to be smart enough to combine them properly.
 *
 * ---
 *
 * config
 *    The config to add the line to
 *
 * line
 *    The line to add to the end of the config
 */
static void config_add_line_uniq_end(struct list *config, const char *line)
{
	struct listnode *node;
	char *pnt;

	for (ALL_LIST_ELEMENTS_RO(config, node, pnt)) {
		if (strcmp(pnt, line) == 0)
			break;
	}

	if (!node)
		config_add_line(config, line);
	else
		listnode_move_to_tail(config, node);
}

void vtysh_config_parse_line(void *arg, const char *line)
{
	char c;
	static struct config *config = NULL;

	if (!line)
		return;

	c = line[0];

	if (c == '\0')
		return;

	switch (c) {
	/* Suppress exclamation points ! and commented lines. The !s are
	 * generated
	 * dynamically in vtysh_config_dump() */
	case '!':
	case '#':
		break;
	case ' ':
		/* Store line to current configuration. */
		if (config) {
			if (config->index == KEYCHAIN_NODE
			    && strncmp(line, " key", strlen(" key")) == 0) {
				config = config_get_nested(
					config, KEYCHAIN_KEY_NODE, line);
			} else if (config->index == KEYCHAIN_KEY_NODE) {
				if (strncmp(line, " exit", strlen(" exit"))
				    == 0) {
					config_add_line_uniq_end(config->line,
								 line);
					config = config->parent;
				} else {
					config_add_line_uniq(config->line,
							     line);
				}
			} else if (strncmp(line, " link-params",
					   strlen(" link-params"))
				   == 0) {
				config_add_line(config->line, line);
				config->index = LINK_PARAMS_NODE;
			} else if (strncmp(line, " ip multicast boundary",
					   strlen(" ip multicast boundary"))
				   == 0) {
				config_add_line_uniq_end(config->line, line);
			} else if (strncmp(line, " ip igmp query-interval",
					   strlen(" ip igmp query-interval"))
				   == 0) {
				config_add_line_uniq_end(config->line, line);
			} else if (config->index == LINK_PARAMS_NODE
				   && strncmp(line, " exit-link-params",
					      strlen(" exit"))
					      == 0) {
				config_add_line(config->line, line);
				config->index = INTERFACE_NODE;
			} else if (!strncmp(line, " vrrp", strlen(" vrrp"))
				   || !strncmp(line, " no vrrp",
					       strlen(" no vrrp"))) {
				config_add_line(config->line, line);
			} else if (!strncmp(line, " ip mroute",
					    strlen(" ip mroute"))) {
				config_add_line_uniq_end(config->line, line);
			} else if (config->index == RMAP_NODE
				   || config->index == INTERFACE_NODE
				   || config->index == VTY_NODE
				   || config->index == NH_GROUP_NODE)
				config_add_line_uniq(config->line, line);
			else
				config_add_line(config->line, line);
		} else
			config_add_line(config_top, line);
		break;
	default:
		if (strncmp(line, "exit", strlen("exit")) == 0) {
			if (config)
				config->exit =
					XSTRDUP(MTYPE_VTYSH_CONFIG_LINE, line);
		} else if (strncmp(line, "interface", strlen("interface")) == 0)
			config = config_get(INTERFACE_NODE, line);
		else if (strncmp(line, "pseudowire", strlen("pseudowire")) == 0)
			config = config_get(PW_NODE, line);
		else if (strncmp(line, "vrf", strlen("vrf")) == 0)
			config = config_get(VRF_NODE, line);
		else if (strncmp(line, "nexthop-group", strlen("nexthop-group"))
			 == 0)
			config = config_get(NH_GROUP_NODE, line);
		else if (strncmp(line, "router-id", strlen("router-id")) == 0)
			config = config_get(ZEBRA_NODE, line);
		else if (strncmp(line, "router rip", strlen("router rip")) == 0)
			config = config_get(RIP_NODE, line);
		else if (strncmp(line, "router ripng", strlen("router ripng"))
			 == 0)
			config = config_get(RIPNG_NODE, line);
		else if (strncmp(line, "router eigrp", strlen("router eigrp"))
			 == 0)
			config = config_get(EIGRP_NODE, line);
		else if (strncmp(line, "router babel", strlen("router babel"))
			 == 0)
			config = config_get(BABEL_NODE, line);
		else if (strncmp(line, "router ospf", strlen("router ospf"))
			 == 0)
			config = config_get(OSPF_NODE, line);
		else if (strncmp(line, "router ospf6", strlen("router ospf6"))
			 == 0)
			config = config_get(OSPF6_NODE, line);
		else if (strncmp(line, "mpls ldp", strlen("mpls ldp")) == 0)
			config = config_get(LDP_NODE, line);
		else if (strncmp(line, "l2vpn", strlen("l2vpn")) == 0)
			config = config_get(LDP_L2VPN_NODE, line);
		else if (strncmp(line, "router bgp", strlen("router bgp")) == 0)
			config = config_get(BGP_NODE, line);
		else if (strncmp(line, "router isis", strlen("router isis"))
			 == 0)
			config = config_get(ISIS_NODE, line);
		else if (strncmp(line, "router openfabric", strlen("router openfabric"))
			 == 0)
			config = config_get(OPENFABRIC_NODE, line);
		else if (strncmp(line, "route-map", strlen("route-map")) == 0)
			config = config_get(RMAP_NODE, line);
		else if (strncmp(line, "no route-map", strlen("no route-map"))
			 == 0)
			config = config_get(RMAP_NODE, line);
		else if (strncmp(line, "pbr-map", strlen("pbr-map")) == 0)
			config = config_get(PBRMAP_NODE, line);
		else if (strncmp(line, "access-list", strlen("access-list"))
			 == 0)
			config = config_get(ACCESS_NODE, line);
		else if (strncmp(line, "ipv6 access-list",
				 strlen("ipv6 access-list"))
			 == 0)
			config = config_get(ACCESS_IPV6_NODE, line);
		else if (strncmp(line, "mac access-list",
				 strlen("mac access-list"))
			 == 0)
			config = config_get(ACCESS_MAC_NODE, line);
		else if (strncmp(line, "ip prefix-list",
				 strlen("ip prefix-list"))
			 == 0)
			config = config_get(PREFIX_NODE, line);
		else if (strncmp(line, "ipv6 prefix-list",
				 strlen("ipv6 prefix-list"))
			 == 0)
			config = config_get(PREFIX_IPV6_NODE, line);
		else if (strncmp(line, "bgp as-path access-list",
				 strlen("bgp as-path access-list"))
			 == 0)
			config = config_get(AS_LIST_NODE, line);
		else if (strncmp(line, "bgp community-list",
				 strlen("bgp community-list"))
				 == 0
			 || strncmp(line, "bgp extcommunity-list",
				    strlen("bgp extcommunity-list"))
				    == 0
			 || strncmp(line, "bgp large-community-list",
				    strlen("bgp large-community-list"))
				    == 0)
			config = config_get(COMMUNITY_LIST_NODE, line);
		else if (strncmp(line, "bgp community alias",
				 strlen("bgp community alias")) == 0)
			config = config_get(COMMUNITY_ALIAS_NODE, line);
		else if (strncmp(line, "ip route", strlen("ip route")) == 0)
			config = config_get(IP_NODE, line);
		else if (strncmp(line, "ipv6 route", strlen("ipv6 route")) == 0)
			config = config_get(IP_NODE, line);
		else if (strncmp(line, "key", strlen("key")) == 0)
			config = config_get(KEYCHAIN_NODE, line);
		else if (strncmp(line, "line", strlen("line")) == 0)
			config = config_get(VTY_NODE, line);
		else if ((strncmp(line, "ipv6 forwarding",
				  strlen("ipv6 forwarding"))
			  == 0)
			 || (strncmp(line, "ip forwarding",
				     strlen("ip forwarding"))
			     == 0))
			config = config_get(FORWARDING_NODE, line);
		else if (strncmp(line, "debug vrf", strlen("debug vrf")) == 0)
			config = config_get(VRF_DEBUG_NODE, line);
		else if (strncmp(line, "debug northbound",
				 strlen("debug northbound"))
			 == 0)
			config = config_get(NORTHBOUND_DEBUG_NODE, line);
		else if (strncmp(line, "debug route-map",
				 strlen("debug route-map"))
			 == 0)
			config = config_get(RMAP_DEBUG_NODE, line);
		else if (strncmp(line, "debug resolver",
				 strlen("debug resolver")) == 0)
			config = config_get(RESOLVER_DEBUG_NODE, line);
		else if (strncmp(line, "debug", strlen("debug")) == 0)
			config = config_get(DEBUG_NODE, line);
		else if (strncmp(line, "password", strlen("password")) == 0
			 || strncmp(line, "enable password",
				    strlen("enable password"))
				    == 0)
			config = config_get(AAA_NODE, line);
		else if (strncmp(line, "ip protocol", strlen("ip protocol"))
			 == 0)
			config = config_get(PROTOCOL_NODE, line);
		else if (strncmp(line, "ipv6 protocol", strlen("ipv6 protocol"))
			 == 0)
			config = config_get(PROTOCOL_NODE, line);
		else if (strncmp(line, "ip nht", strlen("ip nht")) == 0)
			config = config_get(PROTOCOL_NODE, line);
		else if (strncmp(line, "ipv6 nht", strlen("ipv6 nht")) == 0)
			config = config_get(PROTOCOL_NODE, line);
		else if (strncmp(line, "mpls", strlen("mpls")) == 0)
			config = config_get(MPLS_NODE, line);
		else if (strncmp(line, "segment-routing",
				 strlen("segment-routing"))
			 == 0)
			config = config_get(SEGMENT_ROUTING_NODE, line);
		else if (strncmp(line, "bfd", strlen("bfd")) == 0)
			config = config_get(BFD_NODE, line);
		else if (strncmp(line, "rpki", strlen("rpki")) == 0)
			config = config_get(RPKI_NODE, line);
		else {
			if (strncmp(line, "log", strlen("log")) == 0 ||
			    strncmp(line, "hostname", strlen("hostname")) ==
				    0 ||
			    strncmp(line, "domainname", strlen("domainname")) ==
				    0 ||
			    strncmp(line, "allow-reserved-ranges",
				    strlen("allow-reserved-ranges")) == 0 ||
			    strncmp(line, "frr", strlen("frr")) == 0 ||
			    strncmp(line, "agentx", strlen("agentx")) == 0 ||
			    strncmp(line, "no log", strlen("no log")) == 0 ||
			    strncmp(line, "no ip prefix-list",
				    strlen("no ip prefix-list")) == 0 ||
			    strncmp(line, "no ipv6 prefix-list",
				    strlen("no ipv6 prefix-list")) == 0 ||
			    strncmp(line, "service cputime-stats",
				    strlen("service cputime-stats")) == 0 ||
			    strncmp(line, "no service cputime-stats",
				    strlen("no service cputime-stats")) == 0 ||
			    strncmp(line, "service cputime-warning",
				    strlen("service cputime-warning")) == 0)
				config_add_line_uniq(config_top, line);
			else
				config_add_line(config_top, line);
			config = NULL;
		}
		break;
	}
}

/* Macro to check delimiter is needed between each configuration line
 * or not. */
#define NO_DELIMITER(I)                                                        \
	((I) == ACCESS_NODE || (I) == PREFIX_NODE || (I) == IP_NODE            \
	 || (I) == AS_LIST_NODE || (I) == COMMUNITY_LIST_NODE                  \
	 || (I) == COMMUNITY_ALIAS_NODE || (I) == ACCESS_IPV6_NODE             \
	 || (I) == ACCESS_MAC_NODE || (I) == PREFIX_IPV6_NODE                  \
	 || (I) == FORWARDING_NODE || (I) == DEBUG_NODE || (I) == AAA_NODE     \
	 || (I) == VRF_DEBUG_NODE || (I) == NORTHBOUND_DEBUG_NODE              \
	 || (I) == RMAP_DEBUG_NODE || (I) == RESOLVER_DEBUG_NODE               \
	 || (I) == MPLS_NODE || (I) == KEYCHAIN_KEY_NODE)

static void configvec_dump(vector vec, bool nested)
{
	struct listnode *mnode, *mnnode;
	struct config *config;
	struct configuration *configuration;
	char *line;
	unsigned int i;

	for (i = 0; i < vector_active(vec); i++)
		if ((configuration = vector_slot(vec, i)) != NULL) {
			while ((config = config_master_pop(
					&configuration->master))) {
				config_master_hash_del(
					&configuration->hash_master, config);
				/* Don't print empty sections for interface.
				 * Route maps on the
				 * other hand could have a legitimate empty
				 * section at the end.
				 * VRF is handled in the backend, we could have
				 * "configured" VRFs with static routes which
				 * are not under the VRF node.
				 */
				if (config->index == INTERFACE_NODE
				    && (listcount(config->line) == 1)
				    && (line = listnode_head(config->line))
				    && strmatch(line, "exit")) {
					config_del(config);
					continue;
				}

				vty_out(vty, "%s\n", config->name);

				for (ALL_LIST_ELEMENTS(config->line, mnode,
						       mnnode, line))
					vty_out(vty, "%s\n", line);

				configvec_dump(config->nested, true);

				if (config->exit)
					vty_out(vty, "%s\n", config->exit);

				if (!NO_DELIMITER(i))
					vty_out(vty, "!\n");

				config_del(config);
			}
			config_master_fini(&configuration->master);
			config_master_hash_fini(&configuration->hash_master);
			XFREE(MTYPE_VTYSH_CONFIG, configuration);
			vector_slot(vec, i) = NULL;
			if (!nested && NO_DELIMITER(i))
				vty_out(vty, "!\n");
		}
}

void vtysh_config_dump(void)
{
	struct listnode *node, *nnode;
	char *line;

	for (ALL_LIST_ELEMENTS(config_top, node, nnode, line))
		vty_out(vty, "%s\n", line);

	list_delete_all_node(config_top);

	vty_out(vty, "!\n");

	configvec_dump(configvec, false);
}

/* Read up configuration file from file_name. */
static int vtysh_read_file(FILE *confp, bool dry_run)
{
	struct vty *vty;
	int ret;

	vty = vty_new();
	vty->wfd = STDERR_FILENO;
	vty->type = VTY_TERM;
	vty->node = CONFIG_NODE;

	vtysh_execute_no_pager("enable");
	vtysh_execute_no_pager("configure terminal");

	if (!dry_run)
		vtysh_execute_no_pager("XFRR_start_configuration");

	/* Execute configuration file. */
	ret = vtysh_config_from_file(vty, confp);

	if (!dry_run)
		vtysh_execute_no_pager("XFRR_end_configuration");

	vtysh_execute_no_pager("end");
	vtysh_execute_no_pager("disable");

	vty_close(vty);

	return (ret);
}

/* Read up configuration file from config_default_dir. */
int vtysh_read_config(const char *config_default_dir, bool dry_run)
{
	FILE *confp = NULL;
	bool save;
	int ret;

	confp = fopen(config_default_dir, "r");
	if (confp == NULL) {
		fprintf(stderr,
			"%% Can't open configuration file %s due to '%s'.\n",
			config_default_dir, safe_strerror(errno));
		return CMD_ERR_NO_FILE;
	}

	save = vtysh_add_timestamp;
	vtysh_add_timestamp = false;

	ret = vtysh_read_file(confp, dry_run);
	fclose(confp);

	vtysh_add_timestamp = save;

	return (ret);
}

/* We don't write vtysh specific into file from vtysh. vtysh.conf should
 * be edited by hand. So, we handle only "write terminal" case here and
 * integrate vtysh specific conf with conf from daemons.
 */
void vtysh_config_write(void)
{
	char line[512];

	if (cmd_hostname_get()) {
		snprintf(line, sizeof(line), "hostname %s", cmd_hostname_get());
		vtysh_config_parse_line(NULL, line);
	}

	if (cmd_domainname_get()) {
		snprintf(line, sizeof(line), "domainname %s",
			 cmd_domainname_get());
		vtysh_config_parse_line(NULL, line);
	}
	if (vtysh_write_integrated == WRITE_INTEGRATED_NO)
		vtysh_config_parse_line(NULL,
					"no service integrated-vtysh-config");
	if (vtysh_write_integrated == WRITE_INTEGRATED_YES)
		vtysh_config_parse_line(NULL,
					"service integrated-vtysh-config");

	user_config_write();
}

void vtysh_config_init(void)
{
	config_top = list_new();
	config_top->del = (void (*)(void *))line_del;
	configvec = vector_init(1);
}