else if (entry == (struct __sockaddr_rb *)-1)						return -1;				}			}		}	}	#undef __offset	return 0;}#ifdef IPV6static int __proc_icmp6_packet(const struct icmp6_hdr *icmp6, size_t icmplen,							   struct sockaddr *saddr, socklen_t addrlen,							   struct rb_root *root){	struct __sockaddr_rb *entry;	const struct ip6_hdr *ip6hdr;	const struct tcphdr *tcphdr;	if (icmp6->icmp6_type == ICMP6_DST_UNREACH)	{		if (icmplen >= sizeof (struct icmp6_hdr) + sizeof (struct ip6_hdr) + 8)		{			ip6hdr = (const struct ip6_hdr *)(icmp6 + 1);			tcphdr = (const struct tcphdr *)(ip6hdr + 1);			if (ntohs(tcphdr->th_sport) == __tcp_scanner_port &&				ntohl(tcphdr->th_seq) == __tcp_header_seq)			{				((struct sockaddr_in6 *)saddr)->sin6_port = tcphdr->th_dport;				if (!(entry = __rb_insert_sockaddr(saddr, addrlen, root)))				{					if (__info(saddr, addrlen, TS_UNREACH, __arg) < 0)						return -1;				}				else if (entry == (struct __sockaddr_rb *)-1)					return -1;			}		}	}	return 0;}#endifstatic int __recv_icmp_packet(int sockfd, struct rb_root *root){	/* Biggest IPv4 header, ICMP header, the returned IP header with	   8 bytes TCP header. */	#define __BUFSIZE \		((0xf << 2) + sizeof (struct icmphdr) + (0xf << 2) + 8)	char buf[__BUFSIZE];	struct ip *iphdr = (struct ip *)buf;#ifdef IPV6	struct ip6_hdr *ip6hdr = (struct ip6_hdr *)buf;#endif	union __sa_union un;	socklen_t addrlen;	ssize_t n;	while (addrlen = sizeof (union __sa_union), (n = recvfrom(sockfd, buf,							__BUFSIZE, 0, &un.sockaddr, &addrlen)) >= 0)	{		if (un.sockaddr.sa_family == AF_INET)		{			if (n >= sizeof (struct ip) && iphdr->ip_p == IPPROTO_ICMP &&				n >= (iphdr->ip_hl << 2) + sizeof (struct icmp))			{				struct icmp *icmp = (struct icmp *)(buf + (iphdr->ip_hl << 2));				if (__proc_icmp_packet(icmp, n - (iphdr->ip_hl << 2),									   &un.sockaddr, addrlen, root) < 0)					break;			}		}#ifdef IPV6		else if (un.sockaddr.sa_family == AF_INET6)		{			if (n >= sizeof (struct ip6_hdr) + sizeof (struct icmp6_hdr) &&				ip6hdr->ip6_nxt == IPPROTO_ICMPV6)			{				struct icmp6_hdr *icmp6 = (struct icmp6_hdr *)(ip6hdr + 1);				if (__proc_icmp6_packet(icmp6, n - sizeof (struct ip6_hdr),										&un.sockaddr, addrlen, root) < 0)					break;			}		}#endif	}	#undef __BUFSIZE	return n < 0 && errno == EAGAIN ? 0 : -1;}inline static int#ifdef IPV6__scan_ip_seg(const struct in_addr *address, unsigned int bits,			  unsigned short port, int tcpsock, int icmpsock,			  int tcpsock6, int icmpsock6, const struct in_addr *myaddr,			  struct rb_root *root)#else__scan_ip_seg(const struct in_addr *address, unsigned int bits,			  unsigned short port, int tcpsock, int icmpsock,			  const struct in_addr *myaddr, struct rb_root *root)#endif{	unsigned int hostmax = 0;	unsigned int host;	struct sockaddr_in sin;	unsigned int bit = 1;	bzero(&sin, sizeof (struct sockaddr_in));	sin.sin_family = AF_INET;	for (host = 0; host < 32 - bits; host++)	{		hostmax |= bit;		bit <<= 1;	}	host = ntohl(address->s_addr) & ~hostmax;	hostmax |= ntohl(address->s_addr);	do	{		sin.sin_addr.s_addr = htonl(host);		if (!__rb_search_sockaddr((struct sockaddr *)&sin,					sizeof (struct sockaddr_in), root))		{			__tcp_syn(tcpsock, __tcp_scanner_port, port,					  myaddr, (struct sockaddr *)&sin,					  sizeof (struct sockaddr_in));		}		if (__recv_tcp_packet(tcpsock, root) < 0)			return -1;		if (__recv_icmp_packet(icmpsock, root) < 0)			return -1;#ifdef IPV6		if (tcpsock6 >= 0)		{			if (__recv_tcp_packet(tcpsock6, root) < 0)				return -1;			if (__recv_icmp_packet(icmpsock6, root) < 0)				return -1;		}#endif	} while (host++ != hostmax);	return 0;}#ifdef IPV6inline static int__scan_ip6_seg(const struct in6_addr *address, unsigned int bits,			   unsigned short port, int tcpsock, int icmpsock,			   int tcpsock6, int icmpsock6, const struct in6_addr *myaddr,			   struct rb_root *root){	struct in6_addr hostmax;	struct in6_addr host;	struct sockaddr_in6 sin6;	unsigned char bit = 1;	int i, j;	bzero(&hostmax, sizeof (struct in6_addr));	for (i = 15; i > bits >> 3; i--)		hostmax.s6_addr[i] = 0xff;	for (j = 0; j < ((128 - bits) & 7); j++)	{		hostmax.s6_addr[i] |= bit;		bit <<= 1;	}	for (i = 0; i < 4; i++)	{		host.s6_addr32[i] = address->s6_addr32[i] & ~hostmax.s6_addr32[i];		hostmax.s6_addr32[i] |= address->s6_addr32[i];	}	bzero(&sin6, sizeof (struct sockaddr_in6));	sin6.sin6_family = AF_INET6;	while (1)	{		sin6.sin6_addr = host;		if (!__rb_search_sockaddr((struct sockaddr *)&sin6,					sizeof (struct sockaddr_in6), root))		{			__tcp_syn(tcpsock, __tcp_scanner_port, port,					  myaddr, (struct sockaddr *)&sin6,					  sizeof (struct sockaddr_in6));		}		if (tcpsock >= 0)		{			if (__recv_tcp_packet(tcpsock, root) < 0)				return -1;			if (__recv_icmp_packet(icmpsock, root) < 0)				return -1;		}		if (__recv_tcp_packet(tcpsock6, root) < 0)			return -1;		if (__recv_icmp_packet(icmpsock6, root) < 0)			return -1;		if (IN6_ARE_ADDR_EQUAL(&host, &hostmax))			break;		IN6_ADDR_NEXT(&host);	}	return 0;}#endif#ifdef IPV6static int __wait_response(int tcpsock, int icmpsock, int tcpsock6,						   int icmpsock6, struct rb_root *root)#elsestatic int __wait_response(int tcpsock, int icmpsock, struct rb_root *root)#endif{	time_t start = time(NULL);	fd_set all, rset;	struct timeval timeout;	int maxfd = -1;	int n;	#define __max(x, y)		((x) > (y) ? (x) : (y))	if (tcpsock >= 0)	{		FD_SET(tcpsock, &all);		FD_SET(icmpsock, &all);		maxfd = __max(tcpsock, icmpsock);	}#ifdef IPV6	if (tcpsock6 >= 0)	{		FD_SET(tcpsock6, &all);		FD_SET(icmpsock6, &all);		maxfd = __max(maxfd, __max(tcpsock6, icmpsock6));	}#endif	#undef __max	/* Wait at least 2*MSL for all IP segments to expire. */	while ((n = (__max_seg_lifetime << 1) - (time(NULL) - start)) >= 0)	{		timeout.tv_sec = n + 1;		timeout.tv_usec = 0;		rset = all;		if ((n = select(maxfd + 1, &rset, NULL, NULL, &timeout)) > 0)		{			if (tcpsock >= 0)			{				if (FD_ISSET(tcpsock, &rset))				{					if (__recv_tcp_packet(tcpsock, root) < 0)						return -1;				}				if (FD_ISSET(icmpsock, &rset))				{					if (__recv_icmp_packet(icmpsock, root) < 0)						return -1;				}			}#ifdef IPV6			if (tcpsock6 >= 0)			{				if (FD_ISSET(tcpsock6, &rset))				{					if (__recv_tcp_packet(tcpsock6, root) < 0)						return -1;				}				if (FD_ISSET(icmpsock6, &rset))				{					if (__recv_icmp_packet(icmpsock6, root) < 0)						return -1;				}			}#endif		}		else if (n == 0)			break;		else if (n < 0)			return -1;	}	return 0;}int tcp_scan(const struct addrseg *scope, const unsigned short *ports,			 unsigned int ifindex, const char *ifname, int resetuid,			 scan_info_t info, void *arg){	const struct addrseg *p;	const short *port;	int tcpsock = -1, icmpsock = -1;	struct in_addr ipaddr;#ifdef IPV6	int tcpsock6 = -1, icmpsock6 = -1;	struct in6_addr ip6addr;#endif	union __sa_union un;	int i, ret = -1;	struct rb_root root = RB_ROOT;	for (p = scope; p; p = p->as_next)	{		switch (p->as_family)		{		case AF_INET:			tcpsock = -2;			break;#ifdef IPV6		case AF_INET6:			tcpsock6 = -2;			break;#endif		default:			errno = EAFNOSUPPORT;			return -1;		}	}	if (tcpsock == -2)	{		if (getifaddr(AF_INET, ifindex, ifname, &ipaddr) < 0)			goto error;		if ((tcpsock = socket(AF_INET, SOCK_RAW, IPPROTO_TCP)) < 0)			goto error;		if ((icmpsock = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) < 0)			goto error;		bzero(&un.sin, sizeof (struct sockaddr_in));		un.sin.sin_family = AF_INET;		un.sin.sin_addr = ipaddr;		if (bind(tcpsock, &un.sockaddr, sizeof (struct sockaddr_in)) < 0)			goto error;		if (bind(icmpsock, &un.sockaddr, sizeof (struct sockaddr_in)) < 0)			goto error;		if (SET_FD_NONBLOCK(tcpsock) < 0)			goto error;		if (SET_FD_NONBLOCK(icmpsock) < 0)			goto error;	}#ifdef IPV6	if (tcpsock6 == -2)	{		if (getifaddr(AF_INET6, ifindex, ifname, &ip6addr) < 0)			goto error;		if ((tcpsock6 = socket(AF_INET6, SOCK_RAW, IPPROTO_TCP)) < 0)			goto error;		if ((icmpsock6 = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0)			goto error;		bzero(&un.sin6, sizeof (struct sockaddr_in6));		un.sin6.sin6_family = AF_INET6;		un.sin6.sin6_addr = ip6addr;		if (bind(tcpsock6, &un.sockaddr, sizeof (struct sockaddr_in6)) < 0)			goto error;		if (bind(icmpsock6, &un.sockaddr, sizeof (struct sockaddr_in6)) < 0)			goto error;		if (SET_FD_NONBLOCK(tcpsock6) < 0)			goto error;		if (SET_FD_NONBLOCK(icmpsock6) < 0)			goto error;	}#endif	/* We no longer need root privilege. */	if (resetuid)		setuid(getuid());	/* Generate a random TCP sequance. */	srand(time(NULL));	__tcp_header_seq = rand();	__info = info;	__arg = arg;	for (i = 0; i < __tcp_scan_repeats; i++)	{		for (port = ports; *port; port++)		{			for (p = scope; p; p = p->as_next)			{				if (p->as_family == AF_INET)				{#ifdef IPV6					if (__scan_ip_seg(p->as_address, p->as_bits, *port,									  tcpsock, icmpsock, tcpsock6,									  icmpsock6, &ipaddr, &root) < 0)						goto error;#else					if (__scan_ip_seg(p->as_address, p->as_bits,									  *port, tcpsock, icmpsock,									  &ipaddr, &root) < 0)						goto error;#endif				}#ifdef IPV6				else /* if (p->as_family == AF_INET6) */				{					if (__scan_ip6_seg(p->as_address, p->as_bits, *port,									   tcpsock, icmpsock, tcpsock6,									   icmpsock6, &ip6addr, &root) < 0)						goto error;				}#endif			}		}	}#ifdef IPV6	if (__wait_response(tcpsock, icmpsock, tcpsock6, icmpsock6, &root) >= 0)		ret = 0;#else	if (__wait_response(tcpsock, icmpsock, &root) >= 0)		ret = 0;#endiferror:	__rb_destroy_sockaddr(&root);	if (tcpsock >= 0)		close(tcpsock);	if (icmpsock >= 0)		close(icmpsock);#ifdef IPV6	if (tcpsock6 >= 0)		close(tcpsock6);	if (icmpsock6 >= 0)		close(icmpsock6);#endif	return ret;}