/*
    Copyright (c)  2006, 2007		Dmitry Butskoy
					<buc@citadel.stu.neva.ru>
    License:  GPL v2 or any later

    See COPYING for the status of this software.
*/

#include <netinet/in.h>

#include <clif.h>


union common_sockaddr {
	struct sockaddr sa;
	struct sockaddr_in sin;
	struct sockaddr_in6 sin6;
};
typedef union common_sockaddr sockaddr_any;

struct probe_struct {
	int done;
	int final;
	sockaddr_any res;
	double send_time;
	double recv_time;
	int recv_ttl;
	int sk;
	int seq;
	char *ext;
	char err_str[16];	/*  assume enough   */
};
typedef struct probe_struct probe;


struct tr_module_struct {
	struct tr_module_struct *next;
	const char *name;
	int (*init) (const sockaddr_any *dest,
				unsigned int port_seq, size_t *packet_len);
	void (*send_probe) (probe *pb, int ttl);
	void (*recv_probe) (int fd, int revents);
	void (*expire_probe) (probe *pb);
	CLIF_option *options;	/*  per module options, if any   */
	int one_per_time;	/*  no simultaneous probes   */
	size_t header_len;	/*  additional header length (aka for udp)   */
};
typedef struct tr_module_struct tr_module;


#define __TEXT(X)       #X
#define _TEXT(X)        __TEXT(X)

#define DEF_START_PORT	33434	/*  start for traditional udp method   */
#define DEF_UDP_PORT	53	/*  dns   */
#define DEF_TCP_PORT	80	/*  web   */
#define DEF_DCCP_PORT	DEF_START_PORT	/*  is it a good choice?...  */
#define DEF_RAW_PROT	253	/*  for experimentation and testing, rfc3692  */


void error (const char *str) __attribute__((noreturn));
void error_or_perm (const char *str) __attribute__((noreturn));

double get_time (void);
void tune_socket (int sk);
void parse_icmp_res (probe *pb, int type, int code, int info);
void probe_done (probe *pb);

typedef probe *(*check_reply_t) (int sk, int err, sockaddr_any *from,
							char *buf, size_t len);
void recv_reply (int sk, int err, check_reply_t check_reply);

int equal_addr (const sockaddr_any *a, const sockaddr_any *b);

probe *probe_by_seq (int seq);
probe *probe_by_sk (int sk);

void bind_socket (int sk);
void use_timestamp (int sk);
void use_recv_ttl (int sk);
void use_recverr (int sk);
void set_ttl (int sk, int ttl);
int do_send (int sk, const void *data, size_t len, const sockaddr_any *addr);

void add_poll (int fd, int events);
void del_poll (int fd);
void do_poll (double timeout, void (*callback) (int fd, int revents));

void handle_extensions (probe *pb, char *buf, int len, int step);
const char *get_as_path (const char *query);

int raw_can_connect (void);

unsigned int random_seq (void);
uint16_t in_csum (const void *ptr, size_t len);


void tr_register_module (tr_module *module);
const tr_module *tr_get_module (const char *name);

#define TR_MODULE(MOD)	\
static void __init_ ## MOD (void) __attribute__ ((constructor));	\
static void __init_ ## MOD (void) {	\
				\
	tr_register_module (&MOD);	\
}