/*
 * ip-address.c
 * This file is part of Network-inador
 *
 * Copyright (C) 2019, 2020 - Félix Arreola Rodríguez
 *
 * Network-inador 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 of the License, or
 * (at your option) any later version.
 *
 * Network-inador 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 Network-inador; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, 
 * Boston, MA  02110-1301  USA
 */

#include <string.h>

#include <netlink/socket.h>
#include <netlink/msg.h>

#include <net/if_arp.h>
#include <linux/if_addr.h>
#include <arpa/inet.h>

#include "network-inador-private.h"
#include "ip-address.h"
#include "interfaces.h"
//#include "manager.h"
#include "routes.h"

IPAddr *_ip_address_search_addr (Interface *iface, sa_family_t family, void *addr, uint32_t prefix, void *local_addr) {
	FList *g;
	IPAddr *ip_addr;
	int family_size = 0;
	
	if (family == AF_INET) {
		family_size = sizeof (struct in_addr);
	} else if (family == AF_INET6) {
		family_size = sizeof (struct in6_addr);
	}
	
	for (g = iface->address; g != NULL; g = g->next) {
		ip_addr = (IPAddr *) g->data;
		
		if (ip_addr->family != family) continue;
		
		if (memcmp (&ip_addr->addr, addr, family_size) == 0 && ip_addr->prefix == prefix) {
			if (local_addr != NULL) {
				if (memcmp (&ip_addr->local_addr, local_addr, family_size) == 0) {
					return ip_addr;
				}
			} else {
				return ip_addr;
			}
		}
	}
	
	return NULL;
}

int ip_address_receive_message_newaddr (struct nl_msg *msg, void *arg) {
	NetworkInadorHandle *handle = (NetworkInadorHandle *) arg;
	Interface *iface;
	IPAddr *ip_addr;
	
	struct nlmsghdr *reply;
	struct ifaddrmsg *addr_msg;
	int remaining;
	struct nlattr *attr;
	struct ifa_cacheinfo cacheinfo;
	char label[256];
	int label_len;
	
	struct_addr addr;
	struct_addr local_addr;
	struct_addr brd_addr;
	uint32_t new_flags;
	
	/* TODO: Decidir si guardamos también la IP anycast */
	
	int family;
	int has_brd = 0, has_local = 0, has_cacheinfo = 0;
	int family_size = 0;
	int was_new = 0;
	
	reply = nlmsg_hdr (msg);
	
	if (reply->nlmsg_type != RTM_NEWADDR) return NL_SKIP;
	
	addr_msg = nlmsg_data (reply);
	
	iface = _interfaces_locate_by_index (handle->interfaces, addr_msg->ifa_index);
	
	if (iface == NULL) {
		printf ("IP para una interfaz desconocida\n");
		return NL_SKIP;
	}
	
	//printf ("-> New addr\n");
	
	new_flags = addr_msg->ifa_flags;
	
	family = addr_msg->ifa_family;
	if (family == AF_INET) {
		family_size = sizeof (struct in_addr);
	} else if (family == AF_INET6) {
		family_size = sizeof (struct in6_addr);
	}
	
	label[0] = 0;
	label_len = 0;
	
	/* Prevaciar el cacheinfo */
	cacheinfo.ifa_prefered = INFINITY_LIFE_TIME;
	cacheinfo.ifa_valid = INFINITY_LIFE_TIME;
	cacheinfo.cstamp = 0;
	cacheinfo.tstamp = 0;
	
	nlmsg_for_each_attr(attr, reply, sizeof (struct ifaddrmsg), remaining) {
		//printf ("-> new addr type attr: %i\n", nla_type (attr));
		switch (nla_type (attr)) {
			case IFA_FLAGS:
				new_flags = nla_get_u32 (attr);
				break;
			case IFA_ADDRESS:
				memcpy (&addr, nla_data (attr), nla_len (attr));
				break;
			case IFA_LOCAL:
				memcpy (&local_addr, nla_data (attr), nla_len (attr));
				has_local = 1;
				break;
			case IFA_BROADCAST:
				memcpy (&brd_addr, nla_data (attr), nla_len (attr));
				has_brd = 1;
				break;
			case IFA_CACHEINFO:
				memcpy (&cacheinfo, nla_data (attr), nla_len (attr));
				printf ("Cache info timestamp: preferred: %u, valid: %u, created: %u, updated: %u\n", cacheinfo.ifa_prefered, cacheinfo.ifa_valid, cacheinfo.cstamp, cacheinfo.tstamp);
				has_cacheinfo = 1;
				break;
			case IFA_LABEL:
				label_len = nla_len (attr);
				memcpy (label, nla_data(attr), label_len);
				label[label_len] = 0;
				printf ("-> La IP tiene label: %s\n", label);
				break;
		}
	}
	
	ip_addr = _ip_address_search_addr (iface, family, &addr, addr_msg->ifa_prefixlen, (has_local ? &local_addr : NULL));
	
	/* Agregar los datos al objeto */
	if (ip_addr == NULL) {
		ip_addr = malloc (sizeof (IPAddr));
		memset (ip_addr, 0, sizeof (*ip_addr));
		
		iface->address = f_list_append (iface->address, ip_addr);
		
		ip_addr->family = addr_msg->ifa_family;
		memcpy (&ip_addr->addr, &addr, family_size);
		
		ip_addr->prefix = addr_msg->ifa_prefixlen;
		ip_addr->iface = iface;
		
		was_new = 1;
	}
	
	ip_addr->flags = new_flags;
	ip_addr->scope = addr_msg->ifa_scope;
	
	/* Actualizar la local o la broadcast */
	ip_addr->is_p2p = 0;
	
	if (has_local) {
		ip_addr->has_local = 1;
		memcpy (&ip_addr->local_addr, &local_addr, family_size);
		/* Revisar si las direcciones son P2P */
		if (memcmp (&local_addr, &addr, family_size) != 0) {
			ip_addr->is_p2p = 1;
		}
	}
	
	ip_addr->label[0] = 0;
	if (label[0] != 0) {
		memcpy (ip_addr->label, label, label_len);
		ip_addr->label[label_len] = 0;
	}
	
	if (has_brd) {
		ip_addr->has_brd = 1;
		memcpy (&ip_addr->brd_addr, &brd_addr, family_size);
	}
	
	if (has_cacheinfo) {
		memcpy (&ip_addr->cacheinfo, &cacheinfo, sizeof (cacheinfo));
	}
	
	if (was_new) {
		//manager_send_event_ip_add (handle, ip_addr);
	} else {
		/* En caso contrario, enviar una actualización de IP */
	}
	
	char buffer[2048];
	char buffer_2[2048];
	if (ip_addr->is_p2p) {
		inet_ntop (ip_addr->family, &ip_addr->addr, buffer_2, sizeof (buffer_2));
		inet_ntop (ip_addr->family, &ip_addr->local_addr, buffer, sizeof (buffer));
		
		printf ("Dirección IP + %s/%d peer %s sobre interfaz: %d, scope: %d, flags: %u\n", buffer, ip_addr->prefix, buffer_2, iface->index, (unsigned int) ip_addr->scope, ip_addr->flags);
	} else {
		inet_ntop (ip_addr->family, &ip_addr->addr, buffer, sizeof (buffer));
		printf ("Dirección IP + %s/%d sobre interfaz: %d, scope: %d, flags: %u\n", buffer, ip_addr->prefix, iface->index, (unsigned int) ip_addr->scope, ip_addr->flags);
	}
	
	return NL_SKIP;
}

int ip_address_receive_message_deladdr (struct nl_msg *msg, void *arg) {
	NetworkInadorHandle *handle = (NetworkInadorHandle *) arg;
	Interface *iface;
	IPAddr *ip_addr = NULL;
	
	struct nlmsghdr *reply;
	struct ifaddrmsg *addr_msg;
	int remaining;
	struct nlattr *attr;
	
	struct_addr addr;
	struct_addr local_addr;
	int family, family_size = 0;
	int has_local = 0;
	
	reply = nlmsg_hdr (msg);
	
	if (reply->nlmsg_type != RTM_DELADDR) return NL_SKIP;
	
	addr_msg = nlmsg_data (reply);
	
	iface = _interfaces_locate_by_index (handle->interfaces, addr_msg->ifa_index);
	
	if (iface == NULL) {
		printf ("IP para una interfaz desconocida\n");
		return NL_SKIP;
	}
	
	family = addr_msg->ifa_family;
	if (family == AF_INET) {
		family_size = sizeof (struct in_addr);
	} else if (family == AF_INET6) {
		family_size = sizeof (struct in6_addr);
	}
	
	//printf ("DEL MSG\n");
	nlmsg_for_each_attr(attr, reply, sizeof (struct ifaddrmsg), remaining) {
		//printf ("-> del addr type attr: %i\n", nla_type (attr));
		switch (nla_type (attr)) {
			case IFA_ADDRESS:
				memcpy (&addr, nla_data (attr), nla_len (attr));
				break;
			case IFA_LOCAL:
				memcpy (&local_addr, nla_data (attr), nla_len (attr));
				has_local = 1;
				break;
		}
	}
	
	route_ask_delayed_delroute (handle);
	
	ip_addr = _ip_address_search_addr (iface, family, &addr, addr_msg->ifa_prefixlen, (has_local ? &local_addr : NULL));
	
	if (ip_addr == NULL) {
		//printf ("IP no encontrada\n");
		return NL_SKIP;
	}
	
	char buffer[2048];
	inet_ntop (ip_addr->family, &ip_addr->local_addr, buffer, sizeof (buffer));
	printf ("Dirección IP - %s/%d sobre interfaz: %d, scope: %d, flags: %u\n", buffer, ip_addr->prefix, iface->index, (unsigned int) ip_addr->scope, ip_addr->flags);
	
	/* Eliminar de la lista ligada */
	iface->address = f_list_remove (iface->address, ip_addr);
	
	/* Notificar del evento */
	//manager_send_event_ip_del (handle, ip_addr);
	
	free (ip_addr);
	
	return NL_SKIP;
}

static int _ip_address_wait_ack_or_error (struct nl_msg *msg, void *arg) {
	int *ret = (int *) arg;
	struct nlmsgerr *l_err;
	struct nlmsghdr *reply;
	
	reply = nlmsg_hdr (msg);
	
	if (reply->nlmsg_type == NLMSG_ERROR) {
		l_err = nlmsg_data (reply);
		
		*ret = l_err->error;
	}
	
	return NL_SKIP;
}

static int _ip_address_wait_error (struct sockaddr_nl *nla, struct nlmsgerr *l_err, void *arg) {
	int *ret = (int *) arg;
	
	*ret = l_err->error;
	
	return NL_SKIP;
}

int ip_address_add_ip (NetworkInadorHandle *handle, int index, IPAddr *ip_addr) {
	struct nl_msg * msg;
	struct ifaddrmsg addr_hdr;
	int ret, error;
	Interface *iface;
	int family_size = 0;
	
	/* TODO: Si no tenemos los route events, podríamos ejecutar una lectura de interfaces para refrescar la lista */
	iface = _interfaces_locate_by_index (handle->interfaces, index);
	
	if (iface == NULL) {
		printf ("Error, solicitaron operación sobre interfaz que no existe\n");
		
		return -1;
	}
	
	addr_hdr.ifa_family = ip_addr->family;
	addr_hdr.ifa_prefixlen = ip_addr->prefix;
	addr_hdr.ifa_flags = ip_addr->flags;
	addr_hdr.ifa_scope = ip_addr->scope;
	addr_hdr.ifa_index = index;
	
	msg = nlmsg_alloc_simple (RTM_NEWADDR, NLM_F_REQUEST);
	ret = nlmsg_append (msg, &addr_hdr, sizeof (addr_hdr), NLMSG_ALIGNTO);
	
	if (ret != 0) {
		nlmsg_free (msg);
		
		return -1;
	}
	
	if (ip_addr->family == AF_INET) {
		family_size = sizeof (struct in_addr);
	} else if (ip_addr->family == AF_INET6) {
		family_size = sizeof (struct in6_addr);
	}
	
	ret = nla_put (msg, IFA_ADDRESS, family_size, &ip_addr->addr);
	if (ip_addr->has_local) {
		ret |= nla_put (msg, IFA_LOCAL, family_size, &ip_addr->local_addr);
	} else {
		ret |= nla_put (msg, IFA_LOCAL, family_size, &ip_addr->addr);
	}
	if (ip_addr->has_brd) {
		ret |= nla_put (msg, IFA_BROADCAST, family_size, &ip_addr->brd_addr);
	}
	
	/* El tiempo preferido no puede ser mayor que el tiempo válido */
	if (ip_addr->cacheinfo.ifa_prefered > ip_addr->cacheinfo.ifa_valid) {
		ip_addr->cacheinfo.ifa_prefered = ip_addr->cacheinfo.ifa_valid;
	}
	
	ret |= nla_put (msg, IFA_CACHEINFO, 16, &ip_addr->cacheinfo);
	
	if (ret != 0) {
		nlmsg_free (msg);
		
		return -1;
	}
	
	nl_complete_msg (handle->nl_sock_route, msg);
	
	ret = nl_send (handle->nl_sock_route, msg);
	
	nlmsg_free (msg);
	if (ret <= 0) {
		return -1;
	}
	
	error = 0;
	nl_socket_modify_cb (handle->nl_sock_route, NL_CB_VALID, NL_CB_CUSTOM, _ip_address_wait_ack_or_error, &error);
	nl_socket_modify_cb (handle->nl_sock_route, NL_CB_INVALID, NL_CB_CUSTOM, _ip_address_wait_ack_or_error, &error);
	nl_socket_modify_cb (handle->nl_sock_route, NL_CB_ACK, NL_CB_CUSTOM, _ip_address_wait_ack_or_error, &error);
	nl_socket_modify_err_cb (handle->nl_sock_route, NL_CB_CUSTOM, _ip_address_wait_error, &error);
	
	ret = nl_recvmsgs_default (handle->nl_sock_route);
	
	if (ret < 0 || error < 0) {
		return -1;
	}
	
	return 0;
}

int ip_address_del_ip (NetworkInadorHandle *handle, int index, IPAddr *ip_addr) {
	struct nl_msg * msg;
	struct ifaddrmsg addr_hdr;
	int ret, error;
	Interface *iface;
	FList *addr_pos;
	int family_size = 0;
	
	/* TODO: Si no tenemos los eventos, podemos ejecutar una lectura de interfaces para refrescar la información */
	iface = _interfaces_locate_by_index (handle->interfaces, index);
	
	if (iface == NULL) {
		printf ("Error, solicitaron operación sobre interfaz que no existe\n");
		
		return -1;
	}
	
	addr_pos = f_list_find (iface->address, ip_addr);
	
	if (addr_pos == NULL) {
		printf ("Error, la dirección solicitada no pertenece a la interfaz\n");
		
		return -1;
	}
	
	addr_hdr.ifa_family = ip_addr->family;
	addr_hdr.ifa_prefixlen = ip_addr->prefix;
	addr_hdr.ifa_flags = ip_addr->flags;
	addr_hdr.ifa_scope = ip_addr->scope;
	addr_hdr.ifa_index = index;
	
	msg = nlmsg_alloc_simple (RTM_DELADDR, NLM_F_REQUEST);
	ret = nlmsg_append (msg, &addr_hdr, sizeof (addr_hdr), NLMSG_ALIGNTO);
	
	if (ret != 0) {
		nlmsg_free (msg);
		
		return -1;
	}
	
	if (ip_addr->family == AF_INET) {
		family_size = sizeof (struct in_addr);
	} else if (ip_addr->family == AF_INET6) {
		family_size = sizeof (struct in6_addr);
	}
	
	ret = nla_put (msg, IFA_ADDRESS, family_size, &ip_addr->addr);
	if (ip_addr->has_local) {
		ret |= nla_put (msg, IFA_LOCAL, family_size, &ip_addr->local_addr);
	}
	if (ip_addr->has_brd) {
		ret |= nla_put (msg, IFA_BROADCAST, family_size, &ip_addr->brd_addr);
	}
	
	if (ret != 0) {
		nlmsg_free (msg);
		
		return -1;
	}
	
	nl_complete_msg (handle->nl_sock_route, msg);
	
	ret = nl_send (handle->nl_sock_route, msg);
	
	nlmsg_free (msg);
	if (ret <= 0) {
		return -1;
	}
	
	error = 0;
	nl_socket_modify_cb (handle->nl_sock_route, NL_CB_VALID, NL_CB_CUSTOM, _ip_address_wait_ack_or_error, &error);
	nl_socket_modify_cb (handle->nl_sock_route, NL_CB_INVALID, NL_CB_CUSTOM, _ip_address_wait_ack_or_error, &error);
	nl_socket_modify_cb (handle->nl_sock_route, NL_CB_ACK, NL_CB_CUSTOM, _ip_address_wait_ack_or_error, &error);
	nl_socket_modify_err_cb (handle->nl_sock_route, NL_CB_CUSTOM, _ip_address_wait_error, &error);
	
	ret = nl_recvmsgs_default (handle->nl_sock_route);
	
	if (ret < 0 || error < 0) {
		return -1;
	}
	
	return 0;
}

void ip_address_init (NetworkInadorHandle *handle) {
	/* Si es la primera vez que nos llaman, descargar una primera lista de direcciones en todas las interfaces */
	struct nl_msg * msg;
	struct ifaddrmsg addr_hdr = {
		.ifa_family = AF_UNSPEC,
	};
	int ret;
	
	msg = nlmsg_alloc_simple (RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP);
	ret = nlmsg_append (msg, &addr_hdr, sizeof (addr_hdr), NLMSG_ALIGNTO);
	
	if (ret != 0) {
		return;
	}
	
	nl_complete_msg (handle->nl_sock_route, msg);
	
	ret = nl_send (handle->nl_sock_route, msg);
	
	nlmsg_free (msg);
	
	nl_socket_modify_cb (handle->nl_sock_route, NL_CB_VALID, NL_CB_CUSTOM, ip_address_receive_message_newaddr, handle);
	
	nl_recvmsgs_default (handle->nl_sock_route);
}