NetworkInador/src/dhcp_client.c

/*
 * dhcp_client.c
 * This file is part of Network Inador
 *
 * Copyright (C) 2021 - 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 <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <fcntl.h>
#include <sys/types.h>
#include <signal.h>

#include "interfaces.h"
#include "common.h"

#include "dhcp_client.h"
#include "network-inador-manager.h"

void interfaces_dhcp_client_ignore_kill (GPid pid, gint status, gpointer data) {
	g_spawn_check_exit_status (status, NULL);
}

void interfaces_dhcp_prepare_args_for_dhclient (char **argv, int size, char *iface_name) {
	gchar pid_file[256];
	
	snprintf (pid_file, sizeof (pid_file), "/run/dhclient-%s.pid", iface_name);
	/* Preparar los argumentos para el proceso */
	argv[0] = "/sbin/dhclient";
	argv[1] = "-d";
	argv[2] = "-q";
	argv[3] = "-pf";
	argv[4] = pid_file;
	argv[5] = "-sf";
	argv[6] = "/home/gatuno/Proyectos/NetworkInador/src/ni-iface-helper";
	argv[7] = iface_name;
	argv[8] = NULL;
}

void interfaces_dhcp_client_killed_cb (GPid pid, gint status, gpointer data) {
	Interface *iface = (Interface *) data;
	gboolean ret;
	GError *error = NULL;
	char *argv[20];
	
	/* Preparar los argumentos */
	interfaces_dhcp_prepare_args_for_dhclient (argv, 20, iface->name);
	
	if (g_spawn_check_exit_status (status, NULL)) {
		/* Revisar si necesito algo */
	}
	
	if (iface->dhcpc.type == IFACE_ISC_DHCLIENT) {
		if (iface->dhcpc.flags & DHCP_CLIENT_FLAG_AUTO_RESTART) {
			/* Se cerró o mataron el proceso, reiniciar */
			ret = g_spawn_async_with_pipes (
				"/",
				argv,
				NULL,
				G_SPAWN_DO_NOT_REAP_CHILD,
				NULL,
				NULL, 
				&iface->dhcpc.process_pid,
				NULL,
				NULL,
				NULL,
				&error);

			if (ret == FALSE) {
				printf ("Error dhcp: %s\n", error->message);
				g_error_free (error);
				error = NULL;
				
				iface->dhcpc.flags = DHCP_CLIENT_KILLED;
				iface->dhcpc.process_watch = 0;
			} else {
				iface->dhcpc.dhcp_state = DHCP_CLIENT_EXTERNAL_RUNNING;
				iface->dhcpc.process_watch = g_child_watch_add (iface->dhcpc.process_pid, interfaces_dhcp_client_killed_cb, iface);
			}
		} else {
			/* En caso contrario, solo dejar la muerte escrita */
			iface->dhcpc.flags = DHCP_CLIENT_KILLED;
			iface->dhcpc.process_watch = 0;
		}
	}
}

int interfaces_dhcp_client_run (NetworkInadorHandle *handle, int index, int type, uint32_t flags) {
	/* IFNAMSIZ */
	Interface *iface;
	gboolean ret;
	GError *error = NULL;
	char *argv[20];
	
	iface = _interfaces_locate_by_index (handle->interfaces, index);
	
	if (iface == NULL) {
		printf ("Error, solicitaron operación sobre interfaz que no existe\n");
		
		return -1;
	}
	
	/* Preparar los argumentos */
	interfaces_dhcp_prepare_args_for_dhclient (argv, 20, iface->name);
	
	if (iface->dhcpc.type != IFACE_NO_DHCP) {
		/* No puedo correr otro tipo de DHCP */
		return -1;
	}
	
	if (iface->dhcpc.type == IFACE_ISC_DHCLIENT && iface->dhcpc.dhcp_state != DHCP_CLIENT_KILLED) {
		/* El cliente de dhcp ya está corriendo, no hacer nada */
		return -1;
	}
	
	ret = g_spawn_async_with_pipes (
		"/",
		argv,
		NULL,
		G_SPAWN_DO_NOT_REAP_CHILD,
		NULL,
		NULL, 
		&iface->dhcpc.process_pid,
		NULL,
		NULL,
		NULL,
		&error);
	
	if (ret == FALSE) {
		
		printf ("Error dhcp: %s\n", error->message);
		g_error_free (error);
		error = NULL;
		
		return -1;
	}
	
	iface->dhcpc.dhcp_state = DHCP_CLIENT_EXTERNAL_RUNNING;
	iface->dhcpc.type = IFACE_ISC_DHCLIENT;
	iface->dhcpc.flags = flags;
	
	iface->dhcpc.process_watch = g_child_watch_add (iface->dhcpc.process_pid, interfaces_dhcp_client_killed_cb, iface);
	
	return 0;
}

void interfaces_dhcp_client_stop (NetworkInadorHandle *handle, int index) {
	Interface *iface;
	
	iface = _interfaces_locate_by_index (handle->interfaces, index);
	
	if (iface == NULL) {
		printf ("Error, solicitaron operación sobre interfaz que no existe\n");
		
		return;
	}
	
	if (iface->dhcpc.type == IFACE_NO_DHCP) {
		return;
	}
	
	if (iface->dhcpc.type == IFACE_ISC_DHCLIENT) {
		if (iface->dhcpc.dhcp_state == DHCP_CLIENT_KILLED) return;
		
		/* Proceso, matar y reiniciar estado */
		iface->dhcpc.type = IFACE_NO_DHCP;
		iface->dhcpc.flags &= (~DHCP_CLIENT_FLAG_AUTO_RESTART);
		
		g_source_remove (iface->dhcpc.process_watch);
		iface->dhcpc.process_watch = 0;
		g_child_watch_add (iface->dhcpc.process_pid, interfaces_dhcp_client_ignore_kill, NULL);
		
		kill (iface->dhcpc.process_pid, SIGTERM);
	}
}

void interfaces_dhcp_client_internal_set_status (NetworkInadorHandle *handle, int index, int status) {
	Interface *iface;
	
	iface = _interfaces_locate_by_index (handle->interfaces, index);
	
	if (iface == NULL) {
		printf ("Error, solicitaron operación sobre interfaz que no existe\n");
		
		return;
	}
	
	if (iface->dhcpc.type == IFACE_NO_DHCP) {
		return;
	}
	
	if (iface->dhcpc.type == IFACE_ISC_DHCLIENT) {
		/* Un proceso muerto no puede informar de cambios de estados */
		if (iface->dhcpc.dhcp_state == DHCP_CLIENT_KILLED) return;
		
		switch (status) {
			case NET_INADOR_DHCP_STATUS_INITING:
				iface->dhcpc.dhcp_state = DHCP_CLIENT_INITING;
				break;
		}
	}
}