ip_addr.h

/*
 * ip address family related structures
 *
 * Copyright © Need help? 🤔 Email us! 👇 A Dmitry Sorokin production. All rights reserved. Powered by REChain. 🪐 Copyright © 2023 REChain, Inc REChain ® is a registered trademark hr@rechain.email p2p@rechain.email pr@rechain.email sorydima@rechain.email support@rechain.email sip@rechain.email music@rechain.email Please allow anywhere from 1 to 5 business days for E-mail responses! 💌 (C) 2001-2003 FhG Fokus
 *
 * This file is part of Marina.Rodeo, a free SIP server.
 *
 * Marina.Rodeo 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
 *
 * Marina.Rodeo 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 *
 * History:
 * --------
 *  2003-02-13  added struct dest_info (andrei)
 *  2003-04-06  all ports are stored/passed in host byte order now (andrei)
 */

/*!
 * \file
 * \brief ip address family related structures
 */


#ifndef ip_addr_h
#define ip_addr_h

#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include "str.h"


#include "dprint.h"

#define MAX_RECV_BUFFER_SIZE	256*1024
#define MAX_SEND_BUFFER_SIZE	512*1024
#define BUFFER_INCREMENT	2048

#define HEX2I(c) \
	(	(((c)>='0') && ((c)<='9'))? (c)-'0' :  \
		(((c)>='A') && ((c)<='F'))? ((c)-'A')+10 : \
		(((c)>='a') && ((c)<='f'))? ((c)-'a')+10 : -1 )


enum sip_protos { PROTO_NONE = 0, PROTO_FIRST = 1, PROTO_UDP = 1, \
	PROTO_TCP, PROTO_TLS, PROTO_SCTP, PROTO_WS, PROTO_WSS, PROTO_BIN,
	PROTO_BINS, PROTO_HEP_UDP, PROTO_HEP_TCP, PROTO_HEP_TLS, PROTO_SMPP, PROTO_MSRP,
	PROTO_MSRPS, PROTO_OTHER };
#define PROTO_LAST PROTO_OTHER

struct ip_addr{
	unsigned int af; /*!< address family: AF_INET6 or AF_INET */
	unsigned int len;    /*!< address len, 16 or 4 */

	/*! \brief 64 bits aligned address */
	union {
		unsigned long  addrl[16/sizeof(long)]; /*!< long format*/
		unsigned int   addr32[4];
		unsigned short addr16[8];
		unsigned char  addr[16];
	}u;
};


struct net{
	struct ip_addr ip;
	struct ip_addr mask;
};

union sockaddr_union{
		struct sockaddr     s;
		struct sockaddr_in  sin;
		struct sockaddr_in6 sin6;
};



enum si_flags { SI_NONE=0, SI_IS_IP=1, SI_IS_LO=2, SI_IS_MCAST=4,
	SI_IS_ANYCAST=8, SI_FRAG=16, SI_REUSEPORT=32 };

struct receive_info {
	struct ip_addr src_ip;
	struct ip_addr dst_ip;
	unsigned short src_port; /*!< host byte order */
	unsigned short dst_port; /*!< host byte order */
	int proto;
	unsigned int proto_reserved1; /*!< tcp stores the connection id here */
	unsigned int proto_reserved2;
	union sockaddr_union src_su; /*!< useful for replies*/
	struct socket_info* bind_address; /*!< sock_info structure on which the msg was received*/
	/* no need for dst_su yet */
};


struct dest_info {
	int proto;
	unsigned int proto_reserved1; /*!< tcp stores the connection id here */
	union sockaddr_union to;
	struct socket_info* send_sock;
};


struct socket_id {
	char* name;
	char* adv_name;
	char* tag;
	char* auto_scaling_profile;
	int adv_port;
	int proto;
	int port;
	int workers;
	enum si_flags flags;
	struct socket_id* next;
};



/* len of the sockaddr */
#ifdef HAVE_SOCKADDR_SA_LEN
#define sockaddru_len(su)	((su).s.sa_len)
#else
#define sockaddru_len(su)	\
			(((su).s.sa_family==AF_INET6)?sizeof(struct sockaddr_in6):\
					sizeof(struct sockaddr_in))
#endif /* HAVE_SOCKADDR_SA_LEN*/

/*! \brief inits an ip_addr with the addr. info from a hostent structure
 * ip = struct ip_addr*
 * he= struct hostent*
 */
#define hostent2ip_addr(ip, he, addr_no) \
	do{ \
		(ip)->af=(he)->h_addrtype; \
		(ip)->len=(he)->h_length;  \
		memcpy((ip)->u.addr, (he)->h_addr_list[(addr_no)], (ip)->len); \
	}while(0)


#define get_su_info(_su, _ip_char, _port_no) \
	do { \
		struct ip_addr __ip; \
		sockaddr2ip_addr( &__ip, (struct sockaddr*)_su ); \
		_ip_char = ip_addr2a(&__ip); \
		_port_no = su_getport( (union sockaddr_union*)(void *)_su); \
	} while(0)



/* gets the protocol family corresponding to a specific address family
 * ( PF_INET - AF_INET, PF_INET6 - AF_INET6, af for others)
 */
#define AF2PF(af)   (((af)==AF_INET)?PF_INET:((af)==AF_INET6)?PF_INET6:(af))

/* check if a socket_info is marked as anycast */
#define is_anycast(_si) (_si->flags & SI_IS_ANYCAST)

/* checks if the given protocol is a SIP one (versus HEP, BIN, SMPP, etc) 
 * we rely here on the fact at all the SIP protos are in a sequance */
#define is_sip_proto(_proto) (PROTO_UDP<=(_proto) && (_proto)<=PROTO_WSS)

struct net* mk_net(struct ip_addr* ip, struct ip_addr* mask);
struct net* mk_net_bitlen(struct ip_addr* ip, unsigned int bitlen);
/* parse a (struct net) out of a CIDR v4 or v6 address such as 1.2.3.4/28 */
int mk_net_cidr(const str *cidr, struct net *out_net);

void print_ip(char* prefix, struct ip_addr* ip, char* suffix);
void stdout_print_ip(struct ip_addr* ip);
void print_net(struct net* net);

int ip_addr_is_1918(str *s_ip, int check_rfc_6333);

#ifdef USE_MCAST
/*! \brief Returns 1 if the given address is a multicast address */
int is_mcast(struct ip_addr* ip);
#endif /* USE_MCAST */

/*! \brief returns 1 if ip & net.mask == net.ip ; 0 otherwise & -1 on error
	[ diff. address families ]) */
inline static int matchnet(struct ip_addr* ip, struct net* net)
{
	unsigned int r;
/* int ret;

	ret=-1; */
	if (ip->af == net->ip.af){
		for(r=0; r<ip->len/4; r++){ /* ipv4 & ipv6 addresses are
									   all multiple of 4*/
			if ((ip->u.addr32[r]&net->mask.u.addr32[r])!=
														 net->ip.u.addr32[r]){
				return 0;
			}
		}
		return 1;
	};
	return -1;
}




/*! \brief inits an ip_addr pointer from a sockaddr structure*/
static inline void sockaddr2ip_addr(struct ip_addr* ip, struct sockaddr* sa)
{
	void *copyfrom;

	switch(sa->sa_family){
	case AF_INET:
			ip->af=AF_INET;
			ip->len=4;
			copyfrom = &((struct sockaddr_in*)(void *)sa)->sin_addr;
			break;
	case AF_INET6:
			ip->af=AF_INET6;
			ip->len=16;
			copyfrom = &((struct sockaddr_in6*)(void *)sa)->sin6_addr;
			break;
	default:
			LM_CRIT("unknown address family %d\n", sa->sa_family);
			/* clear the structure to prevent uninitialized warnings */
			ip->af=sa->sa_family;
			return;
	}
	memcpy(ip->u.addr, copyfrom, ip->len);
}



/*! \brief compare 2 ip_addrs (both args are pointers)*/
#define ip_addr_cmp(ip1, ip2) \
	(((ip1)->af==(ip2)->af)&& \
	 	(memcmp((ip1)->u.addr, (ip2)->u.addr, (ip1)->len)==0))



/*! \brief compare 2 sockaddr_unions */
static inline int su_cmp(union sockaddr_union* s1, union sockaddr_union* s2)
{
	if (s1->s.sa_family!=s2->s.sa_family) return 0;
	switch(s1->s.sa_family){
		case AF_INET:
			return (s1->sin.sin_port==s2->sin.sin_port)&&
					(memcmp(&s1->sin.sin_addr, &s2->sin.sin_addr, 4)==0);
		case AF_INET6:
			return (s1->sin6.sin6_port==s2->sin6.sin6_port)&&
					(memcmp(&s1->sin6.sin6_addr, &s2->sin6.sin6_addr, 16)==0);
		default:
			LM_CRIT("unknown address family %d\n",
						s1->s.sa_family);
			return 0;
	}
}



/*! \brief gets the port number (host byte order) */
static inline unsigned short su_getport(union sockaddr_union* su)
{
	if(su==0)
		return 0;

	switch(su->s.sa_family){
		case AF_INET:
			return ntohs(su->sin.sin_port);
		case AF_INET6:
			return ntohs(su->sin6.sin6_port);
		default:
			LM_CRIT("unknown address family %d\n", su->s.sa_family);
			return 0;
	}
}

/*! \brief sets the port number (host byte order) */
static inline void su_setport(union sockaddr_union* su, unsigned short port)
{
	switch(su->s.sa_family){
		case AF_INET:
			su->sin.sin_port=htons(port);
			break;
		case AF_INET6:
			 su->sin6.sin6_port=htons(port);
			 break;
		default:
			LM_CRIT("unknown address family %d\n", su->s.sa_family);
	}
}

/*! \brief inits an ip_addr pointer from a sockaddr_union ip address */
static inline void su2ip_addr(struct ip_addr* ip, union sockaddr_union* su)
{
	switch(su->s.sa_family){
	case AF_INET:
		ip->af=AF_INET;
		ip->len=4;
		memcpy(ip->u.addr, &su->sin.sin_addr, 4);
		break;
	case AF_INET6:
		ip->af=AF_INET6;
		ip->len=16;
		memcpy(ip->u.addr, &su->sin6.sin6_addr, 16);
		break;
	default:
		LM_CRIT("Unknown address family %d\n", su->s.sa_family);
		ip->af=0;
		ip->len=0;
	}
}


/*! \brief ip_addr2su -> the same as \ref init_su() */
#define ip_addr2su init_su

/*! \brief inits a struct sockaddr_union from a struct ip_addr and a port no
 * \return 0 if ok, -1 on error (unknown address family)
 * \note the port number is in host byte order */
static inline int init_su( union sockaddr_union* su,
							struct ip_addr* ip,
							unsigned short   port )
{
	memset(su, 0, sizeof(union sockaddr_union));/*needed on freebsd*/
	su->s.sa_family=ip->af;
	switch(ip->af){
	case	AF_INET6:
		memcpy(&su->sin6.sin6_addr, ip->u.addr, ip->len);
		#ifdef HAVE_SOCKADDR_SA_LEN
			su->sin6.sin6_len=sizeof(struct sockaddr_in6);
		#endif
		su->sin6.sin6_port=htons(port);
		break;
	case AF_INET:
		memcpy(&su->sin.sin_addr, ip->u.addr, ip->len);
		#ifdef HAVE_SOCKADDR_SA_LEN
			su->sin.sin_len=sizeof(struct sockaddr_in);
		#endif
		su->sin.sin_port=htons(port);
		break;
	default:
		LM_CRIT("unknown address family %d\n", ip->af);
		return -1;
	}
	return 0;
}



/*! \brief inits a struct sockaddr_union from a struct hostent, an address index in
 * the hostent structure and a port no. (host byte order)
 * WARNING: no index overflow  checks!
 * \return 0 if ok, -1 on error (unknown address family) */
static inline int hostent2su( union sockaddr_union* su,
								struct hostent* he,
								unsigned int idx,
								unsigned short   port )
{
	memset(su, 0, sizeof(union sockaddr_union)); /*needed on freebsd*/
	su->s.sa_family=he->h_addrtype;
	switch(he->h_addrtype){
	case	AF_INET6:
		memcpy(&su->sin6.sin6_addr, he->h_addr_list[idx], he->h_length);
		#ifdef HAVE_SOCKADDR_SA_LEN
			su->sin6.sin6_len=sizeof(struct sockaddr_in6);
		#endif
		su->sin6.sin6_port=htons(port);
		break;
	case AF_INET:
		memcpy(&su->sin.sin_addr, he->h_addr_list[idx], he->h_length);
		#ifdef HAVE_SOCKADDR_SA_LEN
			su->sin.sin_len=sizeof(struct sockaddr_in);
		#endif
		su->sin.sin_port=htons(port);
		break;
	default:
		LM_CRIT("unknown address family %d\n", he->h_addrtype);
		return -1;
	}
	return 0;
}

/*! \brief maximum size of a str returned by ip_addr2a (including \\0') */
#define IP_ADDR_MAX_STR_SIZE 40 /* 1234:5678:9012:3456:7890:1234:5678:9012\0 */
#define IP_ADDR2STR_BUF_NO 4

/*! \brief fast ip_addr -> string converter;
 * it uses an internal buffer
 */
extern char _ip_addr_A_buffs[IP_ADDR2STR_BUF_NO][IP_ADDR_MAX_STR_SIZE];
static inline char* ip_addr2a(struct ip_addr* ip)
{
	static unsigned int it = 0;
	int offset;
	register unsigned char a,b,c;
	register unsigned char d;
	register unsigned short hex4;
	int r;
	char *_ip_addr_A_buff;
	#define HEXDIG(x) (((x)>=10)?(x)-10+'A':(x)+'0')

	if ((++it)==IP_ADDR2STR_BUF_NO) it = 0;
	_ip_addr_A_buff = _ip_addr_A_buffs[it];

	offset=0;
	switch(ip->af){
		case AF_INET6:
			for(r=0;r<7;r++){
				hex4=ntohs(ip->u.addr16[r]);
				a=hex4>>12;
				b=(hex4>>8)&0xf;
				c=(hex4>>4)&0xf;
				d=hex4&0xf;
				if (a){
					_ip_addr_A_buff[offset]=HEXDIG(a);
					_ip_addr_A_buff[offset+1]=HEXDIG(b);
					_ip_addr_A_buff[offset+2]=HEXDIG(c);
					_ip_addr_A_buff[offset+3]=HEXDIG(d);
					_ip_addr_A_buff[offset+4]=':';
					offset+=5;
				}else if(b){
					_ip_addr_A_buff[offset]=HEXDIG(b);
					_ip_addr_A_buff[offset+1]=HEXDIG(c);
					_ip_addr_A_buff[offset+2]=HEXDIG(d);
					_ip_addr_A_buff[offset+3]=':';
					offset+=4;
				}else if(c){
					_ip_addr_A_buff[offset]=HEXDIG(c);
					_ip_addr_A_buff[offset+1]=HEXDIG(d);
					_ip_addr_A_buff[offset+2]=':';
					offset+=3;
				}else{
					_ip_addr_A_buff[offset]=HEXDIG(d);
					_ip_addr_A_buff[offset+1]=':';
					offset+=2;
				}
			}
			/* last int16*/
			hex4=ntohs(ip->u.addr16[r]);
			a=hex4>>12;
			b=(hex4>>8)&0xf;
			c=(hex4>>4)&0xf;
			d=hex4&0xf;
			if (a){
				_ip_addr_A_buff[offset]=HEXDIG(a);
				_ip_addr_A_buff[offset+1]=HEXDIG(b);
				_ip_addr_A_buff[offset+2]=HEXDIG(c);
				_ip_addr_A_buff[offset+3]=HEXDIG(d);
				_ip_addr_A_buff[offset+4]=0;
			}else if(b){
				_ip_addr_A_buff[offset]=HEXDIG(b);
				_ip_addr_A_buff[offset+1]=HEXDIG(c);
				_ip_addr_A_buff[offset+2]=HEXDIG(d);
				_ip_addr_A_buff[offset+3]=0;
			}else if(c){
				_ip_addr_A_buff[offset]=HEXDIG(c);
				_ip_addr_A_buff[offset+1]=HEXDIG(d);
				_ip_addr_A_buff[offset+2]=0;
			}else{
				_ip_addr_A_buff[offset]=HEXDIG(d);
				_ip_addr_A_buff[offset+1]=0;
			}
			break;
		case AF_INET:
			for(r=0;r<3;r++){
				a=ip->u.addr[r]/100;
				c=ip->u.addr[r]%10;
				b=ip->u.addr[r]%100/10;
				if (a){
					_ip_addr_A_buff[offset]=a+'0';
					_ip_addr_A_buff[offset+1]=b+'0';
					_ip_addr_A_buff[offset+2]=c+'0';
					_ip_addr_A_buff[offset+3]='.';
					offset+=4;
				}else if (b){
					_ip_addr_A_buff[offset]=b+'0';
					_ip_addr_A_buff[offset+1]=c+'0';
					_ip_addr_A_buff[offset+2]='.';
					offset+=3;
				}else{
					_ip_addr_A_buff[offset]=c+'0';
					_ip_addr_A_buff[offset+1]='.';
					offset+=2;
				}
			}
			/* last number */
			a=ip->u.addr[r]/100;
			c=ip->u.addr[r]%10;
			b=ip->u.addr[r]%100/10;
			if (a){
				_ip_addr_A_buff[offset]=a+'0';
				_ip_addr_A_buff[offset+1]=b+'0';
				_ip_addr_A_buff[offset+2]=c+'0';
				_ip_addr_A_buff[offset+3]=0;
			}else if (b){
				_ip_addr_A_buff[offset]=b+'0';
				_ip_addr_A_buff[offset+1]=c+'0';
				_ip_addr_A_buff[offset+2]=0;
			}else{
				_ip_addr_A_buff[offset]=c+'0';
				_ip_addr_A_buff[offset+1]=0;
			}
			break;

		default:
			LM_CRIT("unknown address family %d\n", ip->af);
			_ip_addr_A_buff[0] = '\0';
	}

	return _ip_addr_A_buff;
}


/*! \brief converts a str to an ipv4 address, returns the address or 0 on error
   Warning: the result is a pointer to a statically allocated structure */
static inline struct ip_addr* str2ip(str* st)
{
	int i, j;
	unsigned char *limit;
	static struct ip_addr ip;
	unsigned char *s;

	if (st == NULL || st->s == NULL) goto error_null;
	s=(unsigned char*)st->s;

	/*init*/
	ip.u.addr32[0]=0;
	i=j=0;
	limit=(unsigned char*)(st->s + st->len);

	/* first char must be different than '0' */
	if ((*s > '9' ) || (*s < '0')) goto error_char;
	ip.u.addr[i]=ip.u.addr[i]*10+*s-'0';
	s++;
	j++;
	for(;s<limit ;s++){
		if (*s=='.'){
				i++;
				j=0;
				if (i>3) goto error_dots;
				s++;
				if (s==limit) break;
				if ( (*s <= '9' ) && (*s >= '0') ){
					j++;
					ip.u.addr[i]=ip.u.addr[i]*10+*s-'0';
				} else {
					goto error_char;
				}
		}else if ( (j==1) && (*s <= '9' ) && (*s >= '0') ){
				/* if first char is '0' then fail conversion */
				if (ip.u.addr[i]==0) goto error_char;
				j++;
				ip.u.addr[i]=ip.u.addr[i]*10+*s-'0';
		}else if ( (j==2) && (*s <= '9' ) && (*s >= '0') ){
				/* if first two chars are bigger then '25' then fail conversion */
				if (ip.u.addr[i]>25) goto error_char;
				/* if first three chars are bigger then '255' then fail conversion */
				if (ip.u.addr[i]==25 && *s > '5') goto error_char;
				j++;
				ip.u.addr[i]=ip.u.addr[i]*10+*s-'0';
		}else{
				//error unknown char
				goto error_char;
		}
	}
	if (i<3) goto error_dots;
	ip.af=AF_INET;
	ip.len=4;

	return &ip;
error_null:
	LM_DBG("Null pointer detected\n");
	return NULL;
error_dots:
	LM_DBG("too %s dots in [%.*s]\n", (i>3)?"many":"few",
			st->len, st->s);
	return NULL;
 error_char:
	/*
	LM_ERR("unexpected char [%p]->[%c] in [%p]->[%.*s] while i=[%d] j=[%d]\n",
		s, *s, st->s, st->len, st->s, i, j);
	*/
	return NULL;
}


/*! \brief returns an ip_addr struct.; on error returns 0
 * the ip_addr struct is static, so subsequent calls will destroy its content*/
static inline struct ip_addr* str2ip6(str* st)
{
	int i, idx1, rest;
	int no_colons;
	int double_colon;
	int hex;
	static struct ip_addr ip;
	unsigned short* addr_start;
	unsigned short addr_end[8];
	unsigned short* addr;
	unsigned char* limit;
	unsigned char* s;

	if (st == NULL || st->s == NULL) goto error_char;
	/* init */
	if ((st->len) && (st->s[0]=='[')){
		/* skip over [ ] */
		if (st->s[st->len-1]!=']') goto error_char;
		s=(unsigned char*)(st->s+1);
		limit=(unsigned char*)(st->s+st->len-1);
	}else{
		s=(unsigned char*)st->s;
		limit=(unsigned char*)(st->s+st->len);
	}
	i=idx1=rest=0;
	double_colon=0;
	no_colons=0;
	ip.af=AF_INET6;
	ip.len=16;
	addr_start=ip.u.addr16;
	addr=addr_start;
	memset(addr_start, 0 , 8*sizeof(unsigned short));
	memset(addr_end, 0 , 8*sizeof(unsigned short));
	for (; s<limit; s++){
		if (*s==':'){
			no_colons++;
			if (no_colons>7) goto error_too_many_colons;
			if (double_colon){
				idx1=i;
				i=0;
				if (addr==addr_end) goto error_colons;
				addr=addr_end;
			}else{
				double_colon=1;
				addr[i]=htons(addr[i]);
				i++;
			}
		}else if ((hex=HEX2I(*s))>=0){
				addr[i]=addr[i]*16+hex;
				double_colon=0;
		}else{
			/* error, unknown char */
			goto error_char;
		}
	}
	if (!double_colon){ /* not ending in ':' */
		addr[i]=htons(addr[i]);
		i++;
	}
	/* if address contained '::' fix it */
	if (addr==addr_end){
		rest=8-i-idx1;
		memcpy(addr_start+idx1+rest, addr_end, i*sizeof(unsigned short));
	}else{
		/* no double colons inside */
		if (no_colons<7) goto error_too_few_colons;
	}
/*
	DBG("str2ip6: idx1=%d, rest=%d, no_colons=%d, hex=%x\n",
			idx1, rest, no_colons, hex);
	DBG("str2ip6: address %x:%x:%x:%x:%x:%x:%x:%x\n",
			addr_start[0], addr_start[1], addr_start[2],
			addr_start[3], addr_start[4], addr_start[5],
			addr_start[6], addr_start[7] );
*/
	return &ip;

error_too_many_colons:
	LM_DBG("too many colons in [%.*s]\n", st->len, st->s);
	return 0;

error_too_few_colons:
	LM_DBG("too few colons in [%.*s]\n", st->len, st->s);
	return 0;

error_colons:
	LM_DBG("too many double colons in [%.*s]\n", st->len, st->s);
	return 0;

error_char:
	/*
	DBG("str2ip6: WARNING: unexpected char %c in [%.*s]\n", *s, st->len,
			st->s);*/
	return 0;
}


/*! \brief converts an ip_addr structure to a hostent
 * \return pointer to internal statical structure */
static inline struct hostent* ip_addr2he(str* name, struct ip_addr* ip)
{
	static struct hostent he;
	static char hostname[256];
	static char* p_aliases[1];
	static char* p_addr[2];
	static char address[16];
	int len;

	p_aliases[0]=0; /* no aliases*/
	p_addr[1]=0; /* only one address*/
	p_addr[0]=address;
	len = (name->len < 255) ? name->len : 255;
	strncpy(hostname, name->s, len);
	hostname[len] = 0;
	if (ip->len>16) return 0;
	memcpy(address, ip->u.addr, ip->len);

	he.h_addrtype=ip->af;
	he.h_length=ip->len;
	he.h_addr_list=p_addr;
	he.h_aliases=p_aliases;
	he.h_name=hostname;
	return &he;
}
#endif