/*
 * Copyright (C) NEC Europe Ltd., 2003
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#if TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <sys/timeb.h>
# include <time.h>
#else
# if HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  include <time.h>
# endif
#endif
#include <sys/socket.h>
#include <arpa/inet.h>

#include "relay6_parser.h"
#include "relay6_socket.h"
#include "relay6_database.h"

int 
main(argc, argv)
	int argc;
	char **argv;
{
	int err =0, i;
	FILE *fp;
	int sw = 0;
	int du = 0;
	struct interface *iface;
	struct sockaddr_in6 sin6; 
	char *sf, *eth, *addr;
	struct cifaces *ci;
	struct sifaces *si;
	struct IPv6_uniaddr *unia;
	struct server *sa;
	struct msg_parser *mesg;

	fp = fopen(PIDFILE, "w+");
	if (fp == NULL) {
		printf("COULD NOT WRITE PID FILE\n");
		exit(1);
	}
	fprintf(fp, "%d", getpid());
	fclose(fp);

	signal(SIGINT, handler);
	init_relay();

	if (argc > 1) {
		for (i = 1; i < argc; ++i) {
			if (strcmp(argv[i], "-d") == 0)
				du = 1;
		}
		if (du == 0) {        
			dump = fopen(DUMPFILE, "w+");
			if (dump == NULL) {
				printf("COULD NOT WRITE DUMP FILE: %s\n", DUMPFILE);
				exit(1);
			}               
    	}
		else {
			dump = stderr;
    	}

		if (get_interface_info() == 0)
			goto ERROR;
     
		for(i = 1; i < argc; ++i) {     	
			if (strcmp(argv[i], "-cm") == 0) {
				i++;
				if (get_interface_s(argv[i]) == NULL) {
					err = 5;
					goto ERROR;	
				}     

				sw = 1;
				ci = (struct cifaces *) malloc(sizeof(struct cifaces));
				if (ci == NULL) {
					TRACE(dump, "%s - %s ", dhcp6r_clock(),  
					      "Main--> ERROR NO MORE MEMORY AVAILABLE\n");
					exit(1);
				}
				ci->ciface = strdup(argv[i]);
				ci->next = cifaces_list.next;
				cifaces_list.next = ci;	
          	
				TRACE(dump, "%s - %s'%s'\n", dhcp6r_clock(), 
				      "SETTING UP CLIENT INTERFACE: ", argv[i]);
				continue;  	
			}
			else if (strcmp(argv[i], "-cu") == 0) {
				multicast_off = 1;          		         		
			}
			else if (strcmp(argv[i], "-sm") == 0) {
          		i++;
          		if (get_interface_s(argv[i]) == NULL) {
					err = 5;
					goto ERROR;	
          		} 
				si = (struct sifaces *) malloc(sizeof(struct sifaces));
				if (si == NULL) {
					TRACE(dump, "%s - %s", dhcp6r_clock(), 
					      "Main--> ERROR NO MORE MEMORY AVAILABLE\n");
					exit(1);
				}
				si->siface = strdup(argv[i]);
				si->next = sifaces_list.next;
				sifaces_list.next = si;	
          	
				TRACE(dump, "%s - %s'%s'\n", dhcp6r_clock(), 
				      "SETTING UP SERVER INTERFACE: ", argv[i]);         	    
          	
				continue;
			}
			else if (strcmp(argv[i], "-d") == 0) {
				continue; 
			}
			else if (strcmp(argv[i], "-su") == 0) {	
				i++;
				/* destination address */
				if (inet_pton(AF_INET6, argv[i] , &sin6.sin6_addr) <= 0) { 
					err = 3;
					goto ERROR;	
				}   
          	               
				if (IN6_IS_ADDR_UNSPECIFIED(&sin6.sin6_addr)) {
					err = 3;
					goto ERROR;
				} 
          	
				unia = (struct IPv6_uniaddr *) 
				       malloc(sizeof(struct IPv6_uniaddr));
				if (unia == NULL) {
					TRACE(dump, "%s - %s", dhcp6r_clock(), 
				      	"Main--> ERROR NO MORE MEMORY AVAILABLE\n");
   	            	exit(1);
				}
				unia->uniaddr = strdup(argv[i]);
				unia->next = IPv6_uniaddr_list.next;
				IPv6_uniaddr_list.next = unia;	
          	
				TRACE(dump, "%s - %s'%s'\n", dhcp6r_clock(),
				      "SETTING UP SERVER ADDRESS: ", argv[i]); 
				nr_of_uni_addr += 1;    

          		continue;  		  
			}
			else if (strcmp(argv[i], "-sf") == 0) {
				i++;
				sf = strdup(argv[i]);

				eth = strtok(sf, "+");
				if (eth == NULL) {
					err = 4;
					goto ERROR;
				}
				addr = strtok((sf+strlen(eth)+1), "\0");
				if (addr == NULL) {
					err = 4;
					goto ERROR;
				}               
              
			 	/* destination address	*/
				if (inet_pton(AF_INET6, addr , &sin6.sin6_addr) <= 0) { 
					err = 3;
					goto ERROR;
				}

				if (IN6_IS_ADDR_UNSPECIFIED(&sin6.sin6_addr) ) {
					err = 3;
					goto ERROR;
				}

				if ((iface = get_interface_s(eth)) != NULL) {
					sa = (struct server *) malloc(sizeof(struct server));
					if (sa == NULL) {
						TRACE(dump, "%s - %s", dhcp6r_clock(), 
						      "Main--> ERROR NO MORE MEMORY AVAILABLE\n");
						exit(1);
					}
					sa->serv = strdup(addr);
					sa->next = NULL;
					if (iface->sname != NULL)
						sa->next = iface->sname;                   
					iface->sname = sa;                                                       
					TRACE(dump, "%s - %s%s FOR INTERFACE: %s\n", dhcp6r_clock(),
					      "SETTING UP SERVER ADDRESS: ", addr, eth);
					free(sf);
				}
				else {
					err = 5;
					goto ERROR;
				}

				continue;
			}
			else if ((strcmp(argv[i], "-h") == 0) || 
			         (strcmp(argv[i], "--help") == 0)) {
				command_text();
			}
			else {
				err = 4;
				goto ERROR;	  
			}
		}
	}
	else {
		dump = fopen(DUMPFILE, "w+");
		if (dump == NULL) {
			printf("COULD NOT WRITE DUMP FILE: %s\n", DUMPFILE);
			exit(1);
		}  
             
		if (get_interface_info() == 0)
			goto ERROR;
	}

	if (sw == 1)
		multicast_off = 0;   
     
	init_socket();
  
	if (set_sock_opt() == 0)
		goto ERROR;

	if (fill_addr_struct() == 0)
		goto ERROR;

	if (du == 0) {
		switch(fork()) {
			case 0:
				break;
			case -1:
				perror("fork");
				exit(1);
			default:
				exit(0);
		} 
	}

	while (1) {
		if (check_select() == 1) {
			if (recv_data() == 1) {
				if (get_recv_data() == 1) {
					mesg = create_parser_obj();                  
					if (put_msg_in_store (mesg) == 0)
						mesg->sent = 1; /* mark it for deletion */
				}
			}
		}
	
		send_message();
		delete_messages();
	}

ERROR:
	
	if (err == 3) {
		printf("dhcp6r: malformed address '%s'\n", argv[i]); 
		exit(1);
	} 	

	if (err == 4) {
		printf("dhcp6r: option '%s' not recognized\n", argv[i]); 
		exit(1);
	} 	
 
	if (err == 5) {
		printf("dhcp6r: interface '%s' does not exist \n", argv[i]);
		exit(1);
	}
 
	printf("ERROR OCCURED IN THE RELAY AGENT LOOP, EXITING..........\n");
	exit(1);
}

void 
command_text() 
{
	printf("Usage:\n");
	printf("       dhcp6r [-d] [-cu] [-cm <interface>] [-sm <interface>] "
	       "[-su <address>] [-sf <interface>+<address>] \n");
	exit(1);
}

char*  
dhcp6r_clock() 
{
	time_t tim;
	char *s, *p;

	time(&tim);
	s = ctime(&tim);
  
	p = s;
	do {
		p = strstr(p, " ");
		if (p != NULL) {
			if (*(p-1) == '/')
				*p = '0';
			else
				*p = '/';
		}
	} while(p != NULL);  
  
	p = strstr(s, "\n");
	if (p != NULL)
		*p = '\0';
  
	return s;
}

void  handler(int signo) {
	close(recvsock->recv_sock_desc);
	close(sendsock->send_sock_desc);
	TRACE(dump, "%s - %s", dhcp6r_clock(), 
	      "RELAY AGENT IS STOPPING............\n");  
	fflush(dump);

	exit(0);
}