~wkenzie/invizible/master

/**
 * @file invizible.h
 * @project invizible
 * @author Wesley Kenzie (wkenzie@gmail.com PGP 4c945266)
 * @created April 20, 2011
 * @modified June 19, 2011
 * @version 0.95
 * @copyright 2011. Arthur (Wesley) Kenzie. All Rights Reserved.
 * @license 3-clause BSD License. See accompanying LICENSE file.
 */

#ifndef _INVIZIBLE_H
#define	_INVIZIBLE_H

#ifdef	__cplusplus
extern "C" {
#endif

#include <errno.h>
#include <error.h>
#include <netdb.h>
#include <time.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <netinet/if_ether.h>
#include <arpa/inet.h>
#include <linux/ip.h>
#include <sys/socket.h>
#include "libevwrap.h"
#include "pkcommon.h"

#define INVIZ_MAJOR_VERSION "0.25"
#define INVIZ_MINOR_VERSION "6d"
#define INVIZ_VERSION INVIZ_MAJOR_VERSION"."INVIZ_MINOR_VERSION
#define INVIZ_USING_HPING 1
#define INVIZ_USING_SIGNALS 0
#define HAVE_CTYPE_H 1
//
// /dev/random is blocking and so may be very slow
// /dev/urandom is non-blocking but not as high quality randomness
// can be user-defined with --devrandom= parameter
//
#define INVIZ_DEFAULT_DEVRANDOM "/dev/urandom"
//
#define INVIZ_DEFAULT_SEED_CONSTANT 10253
#define INVIZ_MAX_SEED_CONSTANT 10249000
#define INVIZ_PROTOCOL_SOCKS_PROXY 202 // why this?
#define INVIZ_PROTOCOL_HTTP_PROXY 203 // aribitrary
#define INVIZ_PROTOCOL_UNKNOWN 204 // also arbitrary
#define INVIZ_PROTOCOL_UNKNOWN_PROXY 205 // and this
#define MAX_PROTOCOL_DESC_LEN 16
#define IPPROTO_UDP_DESC "udp"
#define IPPROTO_TCP_DESC "tcp"
#define IPPROTO_ICMP_DESC "icmp"
#define IPPROTO_IP_DESC "ip"
#define IPPROTO_SCTP_DESC "sctp"
#define IPPROTO_RAW_DESC "raw"
#define IPPROTO_HTTPPROXY_DESC "http"
#define IPPROTO_HTTPPROXY_DESC_UPPER "HTTP"
#define IPPROTO_SOCKSPROXY_DESC "socks"
#define IPPROTO_SOCKSPROXY_DESC_UPPER "SOCKS"
#define IPPROTO_PROXY_DESC "proxy"
#define INVIZ_PROTOCOL_UNKNOWN_DESC "unknown"
#define DNS_QUERY_HOSTNAME_SEPARATOR "+"
#define HOST_COM_COUNT 144
#define HOST_ORG_COUNT 12
#define HOST_NET_COUNT 16
#define HOST_OTHER_COUNT 118
#define PK_BUFFER_LEN 512
#define MAX_HOSTNAME_EXT_LEN 16
#define MAX_FILENAME_LEN 512
#define MAX_IP4_LEN 16
#define MAX_IP6_LEN 64
#define MAX_MAC_ADDRESS_LEN 512
#define MAX_IFNAME_LEN 128
#define MIN_IFNAME_LEN 2
#define MAX_PACKETFILTER_LEN 128
#define RECEIVE_PACKET_SIZE 10240
#define UDP_HDR_LEN 8
#define INVIZ_TCP_SYN_WINDOW_SIZE 512
#define IP_TTL_DEFAULT 64
/** DNS error codes 0-5 are as described in RFC 1035. */
#define DNS_ERR_NONE 0
/** The name server was unable to interpret the query */
#define DNS_ERR_FORMAT 1
/** The name server was unable to process this query due to a problem with the name server */
#define DNS_ERR_SERVERFAILED 2
/** The domain name does not exist */
#define DNS_ERR_NOTEXIST 3
/** The name server does not support the requested kind of query */
#define DNS_ERR_NOTIMPL 4
/** The name server refuses to reform the specified operation for policy reasons */
#define DNS_ERR_REFUSED 5
/** The reply was truncated or ill-formatted */
#define DNS_ERR_TRUNCATED 65
/** An unknown error occurred */
#define DNS_ERR_UNKNOWN 66
/** Communication with the server timed out */
#define DNS_ERR_TIMEOUT 67
/** The request was canceled because the DNS subsystem was shut down. */
#define DNS_ERR_SHUTDOWN 68
/** The request was canceled via a call to evdns_cancel_request */
#define DNS_ERR_CANCEL 69
#define DNS_IP4_A 1
#define DNS_PTR 2
#define DNS_IP6_AAAA 3
#define DNS_QUERY_NO_SEARCH 1
#define DNS_OPTION_SEARCH 1
#define DNS_OPTION_NAMESERVERS 2
#define DNS_OPTION_MISC 4
#define DNS_OPTION_HOSTSFILE 8
#define DNS_OPTIONS_ALL 15
#define DNS_ANSWER_SECTION 0
#define DNS_AUTHORITY_SECTION 1
#define DNS_ADDITIONAL_SECTION 2
#define DNS_TYPE_A 1
#define DNS_TYPE_NS 2
#define DNS_TYPE_CNAME 5
#define DNS_TYPE_SOA 6
#define DNS_TYPE_PTR 12
#define DNS_TYPE_MX 15
#define DNS_TYPE_TXT 16
#define DNS_TYPE_AAAA 28
#define DNS_QTYPE_AXFR 252
#define DNS_QTYPE_ALL 255
#define DNS_CLASS_INET 1
#define DNS_FLAGS_AA 0x400
#define DNS_FLAGS_RD 0x080
#define DNS_MAX_IP4_ADDRS 32
#define DNS_MAX_IP6_ADDRS 32
//
// global variables
//
char * hostcoms[HOST_COM_COUNT];
char * hostorgs[HOST_ORG_COUNT];
char * hostnets[HOST_NET_COUNT];
char * hostothers[HOST_OTHER_COUNT];
struct ev_loop * loop;
struct ev_signal signal_watcher;
struct ev_io io_watcher;
struct ev_stat stat_watcher;
struct ev_timer timer_watcher;
struct ev_periodic periodic_watcher;
//
//
//
struct send_tcp {
    struct iphdr ip;
    struct tcphdr tcp;
};
struct recv_tcp {
    struct iphdr ip;
    struct tcphdr tcp;
    char buffer[RECEIVE_PACKET_SIZE];
};
//
// based on libevent dns_struct.h
//
struct dns_server_question {
    int type;
    int dns_question_class;
    char name[1];
};
struct dns_server_request {
    int flags;
    int nquestions;
    struct dns_server_question **questions;
};
struct nameserver {
    int socket;	 /* a connected UDP socket */
    struct sockaddr_storage address;
    socklen_t addrlen;
    int failed_times;  /* number of times which we have given this server a chance */
    int timedout;  /* number of times in a row a request has timed out */
    /* these objects are kept in a circular list */
    struct nameserver *next, *prev;
    /* Outstanding probe request for this nameserver, if any */
    struct request *probe_request;
    char state;  /* zero if we think that this server is down */
    char choked;  /* true if we have an EAGAIN from this server's socket */
    char write_waiting;  /* true if we are waiting for EV_WRITE events */
};
struct request {
    uint8_t *request;  /* the dns packet data */
    uint8_t request_type; /* TYPE_PTR or TYPE_A or TYPE_AAAA */
    unsigned int request_len;
    int reissue_count;
    int tx_count;  /* the number of times that this packet has been sent */
    void *user_pointer;  /* the pointer given to us for this request */
    struct nameserver *ns;	/* the server which we last sent it */
    /* these objects are kept in a circular list */
    struct request *next, *prev;
    uint16_t trans_id;  /* the transaction id */
    unsigned request_appended :1;	/* true if the request pointer is data which follows this struct */
    unsigned transmit_me :1;  /* needs to be transmitted */
    /* XXXX This is a horrible hack. */
    char **put_cname_in_ptr; /* store the cname here if we get one. */
};
struct reply {
    unsigned int type;
    unsigned int have_answer : 1;
    union {
        struct {
            uint32_t addrcount;
            uint32_t addresses[DNS_MAX_IP4_ADDRS];
        } a;
	struct {
            uint32_t addrcount;
            struct in6_addr addresses[DNS_MAX_IP6_ADDRS];
	} aaaa;
	struct {
            char name[NI_MAXHOST];
	} ptr;
    } data;
};
struct udpdata_part1 {
    uint16_t trans_id; // __be16?
    uint16_t flags;
    uint16_t questions;
    uint16_t answers;
    uint16_t authorities;
    uint16_t additionals;
};
struct udpdata_part2 {
    char query_hostname[NI_MAXHOST];
    uint16_t query_type;
    uint16_t query_class;
};
struct udpdata {
    struct udpdata_part1 hdr;
    struct udpdata_part2 qry;
};

struct send_udp {
    struct iphdr ip;
    struct udphdr udp;
    struct udpdata dns;
    char * nextlookuphost;
};
struct recv_udp {
    struct iphdr ip;
    struct udphdr udp;
    char buffer[RECEIVE_PACKET_SIZE];
};
//
/* From synhose.c by knight */
//
struct pseudo_header_tcp {
    unsigned int source_address;
    unsigned int dest_address;
    unsigned char placeholder;
    unsigned char protocol;
    unsigned short tcp_length;
    struct tcphdr tcp;
};
struct pseudo_header_udp {
    unsigned int source_address;
    unsigned int dest_address;
    unsigned char placeholder;
    unsigned char protocol;
    unsigned short udp_length;
    struct udphdr udp;
    struct udpdata dns;
};
//
// courtesy of libevent2/evdns.c
/* Represents part of a reply being built.	(That is, a single RR.) */
//
struct server_reply_item {
	struct server_reply_item *next; /* next item in sequence. */
	char *name; /* name part of the RR */
	uint16_t dns_type; /* The RR type */
	uint16_t dns_class; /* The RR class (usually CLASS_INET) */
	uint32_t ttl; /* The RR TTL */
	char is_name; /* True iff data is a label */
	uint16_t datalen; /* Length of data; -1 if data is a label */
	void *data; /* The contents of the RR */
};
//
// courtesy of libevent2/evdns.c
/* Represents a request that we've received as a DNS server, and holds */
/* the components of the reply as we're constructing it. */
//
struct server_request {
	/* Pointers to the next and previous entries on the list of replies */
	/* that we're waiting to write.	 Only set if we have tried to respond */
	/* and gotten EAGAIN. */
	struct server_request *next_pending;
	struct server_request *prev_pending;

	uint16_t trans_id; /* Transaction id. */
	struct sockaddr_storage addr; /* Where to send the response */
	socklen_t addrlen; /* length of addr */

	int n_answer; /* how many answer RRs have been set? */
	int n_authority; /* how many authority RRs have been set? */
	int n_additional; /* how many additional RRs have been set? */

	struct server_reply_item *answer; /* linked list of answer RRs */
	struct server_reply_item *authority; /* linked list of authority RRs */
	struct server_reply_item *additional; /* linked list of additional RRs */

	/* Constructed response.  Only set once we're ready to send a reply. */
	/* Once this is set, the RR fields are cleared, and no more should be set. */
	char *response;
	size_t response_len;

        struct dns_server_request base;
};
//
// function prototypes
//
void doinvizible(unsigned int, unsigned int, const char *, int, int, int, int);
void usage(char *);
char * get_lookuphost(const int, char[(int)MAX_HOSTNAME_EXT_LEN]);
char get_lookupchar(char[NI_MAXHOST], int);
void set_socket_recv_buff_size();
//
// callback function(s) for signals
//
#ifdef LIBEV
void sigint_cb(EV_P_ struct ev_signal *, int);
#endif

#ifdef	__cplusplus
}
#endif

#endif	/* _INVIZIBLE_H */