getaddrinfo.c

/*
  $NiH: getaddrinfo.c,v 1.10 2001/12/11 14:37:33 dillo Exp $

  getaddrinfo.c -- name-to-address translation in protocol-independent manner
  Copyright (C) 2000-2002 Dieter Baron

  This file is a replacement for the following library functions:
    getaddrinfo, freeaddrinfo, gai_strerror.
  The author can be contacted at <dillo@giga.or.at>
  
  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:
  1. Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
  2. Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in
     the documentation and/or other materials provided with the
     distribution.
  3. The name of the author may not be used to endorse or promote
     products derived from this software without specific prior
     written permission.
 
  THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
  IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
  IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/



#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>	
#include <netdb.h>
#include <stdlib.h>

#include "config.h"
#include "sockets.h"

#ifndef HAVE_DECL_H_ERRNO
extern int h_errno;
#endif



int
getaddrinfo(const char *nodename, const char *servname,
	    const struct addrinfo *hints, struct addrinfo **res)
{
    struct addrinfo *ai, *airet, *aiprev;
    struct hostent *hp;
    struct sockaddr_in sa;
    struct servent *serv;
    u_short port;
    char addr[4], *s_addr_list[2], **addr_list;
    int addr_len;
    int i;

    /* XXX: check arguments */
    /* XXX: get proto */

    if (hints && hints->ai_family != PF_UNSPEC
	&& hints->ai_family != PF_INET)
	return EAI_FAMILY;

    if ((serv = getservbyname(servname, "tcp")) == NULL) {
	if ((port=atoi(servname))==0
	    && (servname[0]!='0' || servname[1]!='\0')) {
	    return EAI_SERVICE;
	}
	port = htons(port);
    }
    else
	port = (u_short)serv->s_port;

    sa.sin_family = AF_INET;
    sa.sin_port = port;
    memset(sa.sin_zero, 0, 8);

    addr_list = s_addr_list;
    addr_list[0] = addr;
    addr_list[1] = NULL;
    addr_len = 4;

    if (hints->ai_flags & AI_PASSIVE && nodename == NULL) {
	sa.sin_addr.s_addr = INADDR_ANY;
	memcpy(addr_list[0], &sa.sin_addr.s_addr, addr_len);
    }
    else if (inet_aton(nodename, &sa.sin_addr) == 1) {
	memcpy(addr_list[0], &sa.sin_addr.s_addr, addr_len);
    }
    else {
	if ((hp = gethostbyname(nodename)) == NULL) {
	    switch (h_errno) {
	    case TRY_AGAIN:
		return EAI_AGAIN;
	    case HOST_NOT_FOUND:
	    case NO_DATA:
		return EAI_NODATA;
	    case NO_RECOVERY:
	    default:
		return EAI_FAIL;
	    }
	}
	addr_list = hp->h_addr_list;
	addr_len = hp->h_length;
    }

    airet = aiprev = NULL;
    for (i=0; addr_list[i]; i++) {
	if ((ai=malloc(sizeof(struct addrinfo))) == NULL) {
	    freeaddrinfo(airet);
	    return EAI_MEMORY;
	}
	if (airet == NULL)
	    airet = ai;
	if (aiprev)
	    aiprev->ai_next = ai;
	aiprev = ai;

	ai->ai_next = NULL;
	ai->ai_family = AF_INET;
	ai->ai_socktype = SOCK_STREAM; /* XXX: from hints */
	ai->ai_protocol = IPPROTO_TCP; /* XXX: from hints */
	memcpy(&sa.sin_addr, addr_list[i], addr_len);
	if ((ai->ai_addr=malloc(sizeof(struct sockaddr_in))) == NULL) {
	    freeaddrinfo(airet);
	    return EAI_MEMORY;
	}
	memcpy(ai->ai_addr, &sa, sizeof(struct sockaddr_in));
	ai->ai_addrlen = sizeof(struct sockaddr_in);
    }

    *res = airet;
    return 0;
}



void
freeaddrinfo(struct addrinfo *ai)
{
    struct addrinfo *ai2;

    while (ai) {
	ai2 = ai->ai_next;
	free(ai->ai_addr);
	free(ai);
	ai = ai2;
    }
}



char *
gai_strerror(int ecode)
{
    static char *estr[] = {
	"Success",
	"Address family for hostname not supported",
	"Temporary failure in name resolution",
	"Invalid value for ai_flags",
	"Non-recoverable failure in name resolution",
	"ai_family not supported",
	"Memory allocation failure",
	"No address associated with hostname",
	"hostname nor servname provided, or not known",
	"servname not supported for ai_socktype",
	"ai_socktype not supported",
	"System error returned in errno"
    };
    static const int nestr = sizeof(estr)/sizeof(estr[0]);

    return (int)ecode < nestr ? estr[ecode] : "Unknown error";
}