/*
* cdpr - Cisco Discovery Protocol Reporter
* Copyright (c) 2002-2006 MonkeyMental.com
*
* This program will show you which Cisco device your machine is
* connected to based on CDP packets received.
*
* This program 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.
*
* This program 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; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*
* Version History:
*
* 1.0.0	LO	02-06-30	Initial Release
* 1.0.1	LO	02-07-01	ifdef/endif DLT types to deal with older bpf.h headers
* 1.0.2 LO	02-07-02	New filter to better identify CDP packets
* 1.0.3 LO	02-07-03	loop on pcap_next until a valid packet is received.
*						(patch provided Martin Buck <martin.buck@ascom.ch>)
* 1.0.4	LO	02-07-10	Added 1ms timeout to pcap_open_live to fix *BSD
* 1.0.5	LO	02-07-14	Copy packet data to local struct to resolve Bus Errors
*						on Sun machines.
* 1.0.6	LO	02-07-15	More alignment fixes.
* 1.0.7	LO	02-10-29	Port to Win32, autodetection and list generation of
*						PCAP capable devices.
* 1.0.8	LO	03-02-13	Port to arm processor (Zaurus) using a filter specific
* 						to arm processors to work around pcap bug
* 1.1.0	LO	03-04-25	Add central server reporting code
* 1.1.1	LO	03-04-26	Fix compile errors for Win32 on server code
* 1.1.2	LO	03-04-27	Add config file support
* 1.1.3	LO	03-04-28	Add location/description flag for extended info on server
*						Split server code and conf file code into seperate source files
*						Cleanup old server/config file code. Remove cond. compile for CDPRS
*						Create cdpr.h for ext. functions and common defines.
*						Add DNS support to the config file so you can specify a hostname
* 1.1.4	LO	03-06-20	Added -n flag to override hostname sent to server. Added error
*						checking to the socket code.
* 1.1.5	LO	03-06-23	Fix bug where hostname would not be transmitted w/o location set
* 2.0.0	LO	03-06-25	Release - Major revision change due to server reporting code
* 2.0.1	LO	03-07-01	Add sys/types.h to the includes in conffile.c for BSD support
* 2.0.2 LO	03-08-03	Enable timeouts so that cdpr won't wait forever looking for a packet
* 2.0.3	LO	03-08-04	Better cleanup after aborting due to timeout. 
* 2.0.4	LO	03-08-05	Timeout code that actually timesout. Set device to nonblocking
*						mode and loop until packet or timeout. Before, pcap_next would
*						block so the signal handler couldn't acutally exit.
* 2.0.5	LO	03-10-22	Went back to pcap_next() to get the packet, add a default timeout
*						of 5 minutes. Got rid of pktcap.c and timeout.c as they are no
*						longer needed.
* 2.1.0	LO	03-11-08	Release - Got timeout code working on WIN32 port
* 2.2.0	LO	04-04-14	Added the ability specify the port to send the cdpr updates to.
* 2.2.1 LO	06-07-28	Fixed segfault when not providing port to a command line selected server (-s)
*/

/*#include "pcap.h" */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#ifdef WIN32
#include "xgetopt.h"
#include "time.h"
#else
#include <unistd.h>
#endif
#ifdef SOLARIS
#include "u_ints.h"
#endif
#include "cdpr.h"
#include "cdp.h"

void
dump_ip (const u_char *ip)
{
	char switch_ip[100];
	if(cdprs>=1)
	{
		sprintf (switch_ip, "switch_ip=%d.%d.%d.%d",
			(int) ip[0], (int) ip[1], (int) ip[2], (int) ip[3]);
		cdprs_action(CDPRS_DATA, switch_ip, 0);
	}
	printf ("%d.%d.%d.%d",
		(int) ip[0], (int) ip[1], (int) ip[2], (int) ip[3]);
}

void
dump_hex (const u_char *p, int len)
{
	while (len--)
	{
		printf ("%02X ", *p++);
	}
}

void
dump_ascii (const u_char *p, int len)
{
	while (len--)
	{
		printf ("%c", (*p < ' ' || *p > '~') ? '.' : *p);
		++p;
	}
}

void
dump_data (const u_char *p, int len)
{
	int i;

	for (i = 0; i < len; i += 16, p += 16)
	{
		printf ("%p:  ", p);
		dump_hex (p, 16);
		printf (" ");
		dump_ascii (p, 16);
		printf ("\n");
	}
}
char *
get_cdp_type (int type)
{
    int i;

    for (i = 0; type_vals[i].type != 0; ++i)
    {
    	if (type == type_vals[i].type)
    	{
    		return type_vals[i].val;
    	}
    }
    return "Unknown type";
}

void
print_cdp_address (u_char *v, int verbose)
{
	u_int32_t i;
	u_int32_t number;

	memcpy (&number, v, sizeof (number));
	number = ntohl (number);

	if (verbose > 0)
	{
		printf ("  number: %d\n", number);
	}

	v += sizeof (u_int32_t);
	for (i = 0; i < number; ++i)
	{
		u_char protocol      = *v;
		u_char protocol_len  = *(v+1);
		u_char *protocol_val = v+2;
/*		int    address_len   = ntohs(*((u_int16_t *)(v+2+protocol_len)));*/
		u_int16_t address_len;
		u_char *address_val  = v+2+protocol_len+2;

		memcpy (&address_len, (v+2+protocol_len), sizeof(address_len));
		address_len = ntohs(address_len);

		
		if (verbose > 0)
		{
			printf ("  protocol: %02x\n", protocol);
			printf ("  protocol len: %02x\n", protocol_len);
			printf ("  protocol val: ");
			dump_hex (protocol_val, protocol_len);
			printf ("\n");
		
			printf ("  address len: %02x\n", address_len);
			printf ("  address val: ");
		}
		else
		{
			printf ("  value:  ");
		}
		if (protocol_len == 1 && *protocol_val == 0xCC && address_len == 4)
			dump_ip (address_val);
		else
			dump_hex (address_val, address_len);
		printf ("\n");

		v += (2+protocol_len+2+address_len);
	}
}

void
print_cdp_capabilities (u_char *v)
{
	u_int32_t cap;

	memcpy (&cap, v, sizeof (cap));
	cap = ntohl (cap);

	printf ("  value:  %08x\n", cap);
	if (cap & 0x01) printf ("          Performs level 3 routing for at least one network layer protocol.\n");
	if (cap & 0x02) printf ("          Performs level 2 transparent bridging.\n");
	if (cap & 0x04) printf ("          Performs level 2 source-route bridging.\n");
	if (cap & 0x08) printf ("          Performs level 2 switching.\n");
	if (cap & 0x10) printf ("          Sends and receives packets for at least one network layer protocol.\n");
	if (cap & 0x20) printf ("          The bridge or switch does not forward IGMP Report packets on nonrouter ports.\n");
	if (cap & 0x40) printf ("          Provides level 1 functionality.\n");
}

void
print_cdp_packet (const u_char *p, unsigned int plen, int verbose)
{
	CDP_HDR *h;
	CDP_DATA *d;

	h = (CDP_HDR *) p;


	// dump_data (p, 128);

	if (verbose > 1 )
	{
		printf ("\ncdp packet:\n");
		printf ("  version:      %02x\n", h->version);
		printf ("  time to live: %02x\n", h->time_to_live);
		printf ("  checksum:     %04x\n", ntohs (h->checksum));
	}

	d = (CDP_DATA *) (p + sizeof (CDP_HDR));
	plen -= sizeof (CDP_HDR);

	while (plen > sizeof (CDP_DATA))
	{
		int type;
		int length;
		u_char *v;  /* variable data */
		int vlen;   /* length of variable data */
		CDP_DATA data;

		memcpy (&data, d, sizeof (CDP_DATA));
		type = ntohs (data.type);
		length = ntohs (data.length);
		v = (u_char *) d + sizeof (CDP_DATA);
		vlen = length - sizeof (CDP_DATA);
	
		if(verbose > 0 )
		{
            printf ("\ncdp type/len/val:\n");
			printf ("  type:   %04x - %s\n", type, get_cdp_type (type));
			printf ("  length: %04x\n", length);
		}
		switch (type)
		{
		case TYPE_DEVICE_ID:
			printf ("%s\n", get_cdp_type (type));
			printf ("  value:  %.*s\n", vlen, v);
			break;

		case TYPE_ADDRESS:
			printf ("%s\n", get_cdp_type (type));
			print_cdp_address (v, verbose);
			break;

		case TYPE_PORT_ID:
			printf ("%s\n", get_cdp_type (type));
			printf ("  value:  %.*s\n", vlen, v);
			if(cdprs >= 1)
			{
				char port[1024];
				char *portval;
				int portlen;
				portval = urlencode(v, strlen(v), &portlen);
				sprintf(port, "&port=%.*s", portlen, portval);
				free(portval);
				cdprs_action(CDPRS_DATA, port, verbose);
			}
			break;

		case TYPE_CAPABILITIES:
			if(verbose > 0)
			{
				printf ("%s\n", get_cdp_type (type));
				print_cdp_capabilities (v);
			}
			break;

		case TYPE_IOS_VERSION:
			if(verbose > 0)
			{
				printf ("%s\n", get_cdp_type (type));
				printf ("  value:  %.*s\n", vlen, v);
			}
			break;

		case TYPE_PLATFORM:
			if(verbose > 0)
			{
				printf ("%s\n", get_cdp_type (type));
				printf ("  value:  %.*s\n", vlen, v);
			}
			break;

		case TYPE_IP_PREFIX:
			if(verbose > 0)
			{
				printf ("%s\n", get_cdp_type (type));
				printf ("  value:  ");
				dump_hex (v, vlen);
				printf ("\n");
			}
			break;

		case TYPE_VTP_MGMT_DOMAIN:
			if(verbose > 0)
			{
				printf ("%s\n", get_cdp_type (type));
				printf ("  value:  %.*s\n", vlen, v);
			}
			break;

		case TYPE_NATIVE_VLAN:
			if(verbose > 0)
			{
				printf ("%s\n", get_cdp_type (type));
				printf ("  value:  ");
				dump_hex (v, vlen);
				printf ("\n");
			}
			break;
		
		case TYPE_DUPLEX:
			if(verbose > 0)
			{
				printf ("%s\n", get_cdp_type (type));
				printf ("  value:  ");
				dump_hex (v, vlen);
				printf ("\n");
			}
			break;

		default:
			if(verbose > 1)
			{
				printf ("%s\n", get_cdp_type (type));
				printf ("  value:  ");
				dump_hex (v, vlen);
				printf ("\n");
			}
		}

	    plen -= length;
	    d = (CDP_DATA *) ((u_char *) d + length);
	}
}


int
print_dlt(pcap_t *handle)
{
	int type;

	/* Print the DLL Type*/
	switch(type = pcap_datalink(handle))
	{
#ifdef DLT_NULL
		case DLT_NULL:
			printf("Data Link Type: BSD Loopback encapsulation.\n");
			break;
#endif
#ifdef DLT_EN10MB
		case DLT_EN10MB:
			printf("Data Link Type: Ethernet (10MB, 100MB, 1000MB and up).\n");
			break;
#endif
#ifdef DLT_IEEE802
		case DLT_IEEE802:
			printf("Data Link Type: IEEE 802.5 Token Ring.\n");
			break;
#endif
#ifdef DLT_ARCNET
		case DLT_ARCNET:
			printf("Data Link Type: ARCNET.\n");
			break;
#endif
#ifdef DLT_PPP
		case DLT_PPP:
			printf("Data Link Type: PPP (Point-to-Point Protocol).\n");
			break;
#endif
#ifdef DLT_FDDI
		case DLT_FDDI:
			printf("Data Link Type: FDDI.\n");
			break;
#endif
#ifdef DLT_ATM_RFC1483
		case DLT_ATM_RFC1483:
			printf("Data Link Type: RFC 1483 LLC/SNAP-encapsulated ATM.\n");
			break;
#endif
#ifdef DLT_RAW
		case DLT_RAW:
			printf("Data Link Type: raw IP.\n");
			break;
#endif
#ifdef DLT_PPP_SERIAL
		case DLT_PPP_SERIAL:
			printf("Data Link Type: PPP in HDLC-like framing.\n");
			break;
#endif
#ifdef DLT_PPP_ETHER
		case DLT_PPP_ETHER:
			printf("Data Link Type: PPPoE.\n");
			break;
#endif
#ifdef DLT_C_HDLC
		case DLT_C_HDLC:
			printf("Data Link Type: Cisco PPP with HDLC framing.\n");
			break;
#endif
#ifdef DLT_IEEE802_11
		case DLT_IEEE802_11:
			printf("Data Link Type: IEEE 802.11 wireless LAN.\n");
			break;
#endif
#ifdef DLT_LOOP
		case DLT_LOOP:
			printf("Data Link Type: OpenBSD loopback encapsulation.\n");
			break;
#endif
#ifdef DLT_LTALK
		case DLT_LTALK:
			printf("Data Link Type: Apple LocalTalk.\n");
			break;
#endif
		default:
			printf("%d is an unknown Data Link Transport\n", type);
	}

	return 0;
}

int
usage(void)
{
	puts("d: Specify device to use (eth0, hme0, etc.)");
	puts("h: Print this usage");
	puts("t: time in seconds to abort waiting for a packet (should be > 60)");
	puts("v[vv]: Set verbose mode");
	puts("\n** Options dealing with server updates: **");
	puts(" u: Send cdpr information to a cdpr server\n    requires config file as arg");
	puts(" l: Location/description of this port for use with -u or -s and -p");
	puts(" n: Override the hostname reported to the server for use with -u or -s and -p");
	puts(" s: Server to send information to specify port with a : after Server/IP\n     Example: 192.168.1.20:88 (default: 80) requires -p (overridden by -u)");
	puts(" p: Path of server script to send data to requires -s (overridden by -u)");

	exit(0);
}

int
main(int argc, char *argv[])
{
	pcap_t *handle;
	char *dev = NULL;
	char *conf = NULL;
	char *loc = NULL;
	char *name = NULL;
	char *svr = NULL;
	char *path = NULL;
	char errbuf[PCAP_ERRBUF_SIZE];
	struct bpf_program filter;
	/*
	** Filter Expression: 01:00:0c:cc:cc:cc Multicast Mac Address
	** This filter doesn't work on the arm, so use all multicast
	** ether[20:2] = 0x2000: CDP signature in LLC
	*/
#ifdef ZAURUS
	char filter_app[] = "ether multicast and ether[20:2] = 0x2000";
#else
	char filter_app[] = "ether host 01:00:0c:cc:cc:cc and ether[20:2] = 0x2000";
#endif
	bpf_u_int32 mask;
	bpf_u_int32 net;
	struct pcap_pkthdr header;
	const u_char *packet;
	char version[] = "2.2.1";

	int c;
	int verbose=0;
	int locdetail=0;
	int nameoverride=0;
	int cdprs_config=0;
	int cdprs_cmdline=0;
	unsigned int seconds=300;
	time_t start_time=0;

	/* Zero out some global variables */
	timeout=1;
	cdprs=0;
	memset (errbuf, 0, sizeof (errbuf));

	/* Print out header */
	printf("cdpr - Cisco Discovery Protocol Reporter\nVersion %s\n", version);
	printf("Copyright (c) 2002-2006 - MonkeyMental.com\n\n");

	/* Check command-line options */
	while((c = getopt(argc, argv, "d:t:vhu:l:n:s:p:")) !=EOF)
		switch(c)
		{
			case 'd':
				dev = optarg;
				break;
			case 'v':
				verbose++;
				break;
			case 't':
				seconds = atoi(optarg);
				printf("Timeout enabled for %u seconds\n", seconds);
				break;
			case 'u':
				conf = optarg;
				cdprs = 1;
				cdprs_config=1;
				if(cdprs_cmdline)
				{
					puts("Overriding command line server arguments with config file\n");
					cdprs_cmdline = 0;
				}
				cdprs_action(CDPRS_INIT, conf, 0);
				break;
			case 'l':
				loc = optarg;
				locdetail = 1;
				break;
			case 'n':
				name = optarg;
				nameoverride = 1;
				break;
			case 's':
				svr = optarg;
				if(cdprs_config)
				{
					puts("Config file overrides cmd line");
				}
				else
				{
					if(cdprs != 1) cdprs = 1;
					cdprs_cmdline++;
				}
				break;
			case 'p':
				path = optarg;
				if(cdprs_config)
				{
					puts("Config file overrides cmd line");
				}
				else
				{
					if(cdprs != 1) cdprs = 1;
					cdprs_cmdline++;
				}
				break;
			case 'h':
			case '?':
				usage();
				break;
		}

	/*
	** If we are using command line server paths, validate and buld
	** build data structure using functions that are normally used
	** when parsing the config file
	*/
	if(cdprs && (cdprs_cmdline == 2))
	{
		cdprs_action(CDPRS_INIT, "", 0);
		do_something_with(svr, path);
	}
	else if(cdprs && (cdprs_cmdline != 0))
	{
		puts("Error only -s or -p was specified but not both");
		exit(2);
	}

	/* Get a pcap capable device */
	if(dev == NULL)
	{
		int i = 0;
		int inum;
		pcap_if_t *d;
		pcap_if_t *alldevs;

		/* The user didn't provide a packet source: Retrieve the device list */
		if (pcap_findalldevs(&alldevs, errbuf) == -1)
		{
			fprintf(stderr,"Error in pcap_findalldevs: %s\n", errbuf);
			exit(1);
		}
		
		/* Print the list */
		for(d=alldevs; d; d=d->next)
		{
			printf("%d. %s", ++i, d->name);
			if (d->description)
				printf(" (%s)\n", d->description);
			else
				printf(" (No description available)\n");
		}
		
		if(i==0)
		{
			printf("\nNo interfaces found! Make sure pcap is installed.\n");
			return -1;
		}
		
		printf("Enter the interface number (1-%d):",i);
		scanf("%d", &inum);
		
		if(inum < 1 || inum > i)
		{
			printf("\nInterface number out of range.\n");
			/* Free the device list */
			pcap_freealldevs(alldevs);
			return -1;
		}
		
		/* Jump to the selected adapter */
		for(d=alldevs, i=0; i< inum-1 ;d=d->next, i++)
		{
			;
		}
		
		dev = d->name;
	}

	printf("Using Device: %s\n", dev);

	/* Get the network number and netmask */
	pcap_lookupnet(dev, &net, &mask, errbuf);

	/* Open the pcap device */
	if((handle = pcap_open_live(dev, BUFSIZ, 1, 0, errbuf)) == NULL)
	{
		printf("Error opening device (%s)\n", errbuf);
		exit(1);
	}
	else if (strlen(errbuf))
	{
		printf("Warning opening device (%s)\n", errbuf);
	}

	/* Compile the pcap filter */
	pcap_compile(handle, &filter, filter_app, 0, net);

	/* Activate the pcap filter */
	pcap_setfilter(handle, &filter);
	pcap_freecode(&filter);

	/* Set non-blocking mode */
	if(pcap_setnonblock(handle, 1, errbuf))
	{
		pcap_perror(handle, NULL);
	}

	/* Get the next packet that comes in, we only need one */
	printf("Waiting for CDP advertisement:\n");
	printf("(default config is to transmit CDP packets every 60 seconds)\n");

	/* Get current time to check for timeout */
	start_time = time(NULL);
	do
	{
		packet = pcap_next(handle, &header);
#ifdef WIN32
		Sleep(10000);
#else
		usleep(10000);
#endif
	} while ((!packet) && ( timeout=((start_time+seconds) > (unsigned int)time(NULL))) );

	/*
	** timeout expired. clean up and exit
	*/
	if(timeout == 0)
	{
		puts("Aborting due to timeout");
		pcap_close(handle);
		return(2);
	}

	/* Print its length */
	if(verbose > 0)
	{
		printf("Received a CDP packet, header length: %d\n", header.len);
	}

	// print cdp packet, 22 bytes into packet
	print_cdp_packet (packet+22, header.len-22, verbose);

	if (verbose > 1)
	{
		print_dlt(handle);
	}
	
	pcap_close(handle);
	if(cdprs >=1)
	{
		if(locdetail >=1)
		{
			set_location(loc);
		}
		if(nameoverride >= 1)
		{
			get_hostname(nameoverride, name);
		}
		else
		{
			get_hostname(0, NULL);
		}

		cdprs_action(CDPRS_SEND, "", verbose);
	}
	return(0);
}