/*
 * Mar  8, 2000 by Hajimu UMEMOTO <ume@mahoroba.org>
 * $Id: getaddrinfo.c 125 2005-08-27 16:33:10Z ume $
 *
 * This module is besed on ssh-1.2.27-IPv6-1.5 written by
 * KIKUCHI Takahiro <kick@kyoto.wide.ad.jp>
 */
/*
 * fake library for ssh
 *
 * This file includes getaddrinfo(), freeaddrinfo() and gai_strerror().
 * These funtions are defined in rfc2133.
 *
 * But these functions are not implemented correctly. The minimum subset
 * is implemented for ssh use only. For exapmle, this routine assumes
 * that ai_family is AF_INET. Don't use it for another purpose.
 * 
 * In the case not using 'configure --enable-ipv6', this getaddrinfo.c
 * will be used if you have broken getaddrinfo or no getaddrinfo.
 */
#include <sys/param.h>
#include "gai.h"
static struct addrinfo *
malloc_ai(int port, u_long addr, int socktype, int proto)
{
    struct addrinfo *ai;
    ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) +
                                   sizeof(struct sockaddr_in));
    if (ai) {
        memset(ai, 0, sizeof(struct addrinfo) + sizeof(struct sockaddr_in));
        ai->ai_addr = (struct sockaddr *)(ai + 1);
        /* XXX -- ssh doesn't use sa_len */
        ai->ai_addrlen = sizeof(struct sockaddr_in);
#ifdef HAVE_SOCKADDR_SA_LEN
        ai->ai_addr->sa_len = sizeof(struct sockaddr_in);
#endif
        ai->ai_addr->sa_family = ai->ai_family = AF_INET;
        ((struct sockaddr_in *)(ai)->ai_addr)->sin_port = port;
        ((struct sockaddr_in *)(ai)->ai_addr)->sin_addr.s_addr = addr;
        ai->ai_socktype = socktype;
        ai->ai_protocol = proto;
        return ai;
    } else {
        return NULL;
    }
}
char *
gai_strerror(int ecode)
{
    switch (ecode) {
    case EAI_MEMORY:
        return "memory allocation failure.";
    case EAI_FAMILY:
        return "ai_family not supported.";
    case EAI_NONAME:
        return "hostname nor servname provided, or not known.";
    case EAI_SERVICE:
        return "servname not supported for ai_socktype.";
    default:
        return "unknown error.";
    }
}
void
freeaddrinfo(struct addrinfo *ai)
{
    struct addrinfo *next;
    if (ai->ai_canonname)
        free(ai->ai_canonname);
    do {
        next = ai->ai_next;
        free(ai);
    } while ((ai = next) != NULL);
}
int
getaddrinfo(const char *hostname, const char *servname,
            const struct addrinfo *hints, struct addrinfo **res)
{
    struct addrinfo *cur, *prev = NULL;
    struct hostent *hp;
    struct in_addr in;
    int i, port = 0, socktype, proto;
    if (hints && hints->ai_family != PF_INET && hints->ai_family != PF_UNSPEC)
        return EAI_FAMILY;
    socktype = (hints && hints->ai_socktype) ? hints->ai_socktype
                                             : SOCK_STREAM;
    if (hints && hints->ai_protocol)
        proto = hints->ai_protocol;
    else {
        switch (socktype) {
        case SOCK_DGRAM:
            proto = IPPROTO_UDP;
            break;
        case SOCK_STREAM:
            proto = IPPROTO_TCP;
            break;
        default:
            proto = 0;
            break;
        }
    }
    if (servname) {
        if (isdigit((int)*servname))
            port = htons(atoi(servname));
        else {
            struct servent *se;
            char *pe_proto;
            if (hints && hints->ai_flags & AI_NUMERICSERV)
                    return EAI_NONAME;
            switch (socktype) {
            case SOCK_DGRAM:
                pe_proto = "udp";
                break;
            case SOCK_STREAM:
                pe_proto = "tcp";
                break;
            default:
                pe_proto = NULL;
                break;
            }
            if ((se = getservbyname(servname, pe_proto)) == NULL)
                return EAI_SERVICE;
            port = se->s_port;
        }
    }
    if (!hostname) {
        if (hints && hints->ai_flags & AI_PASSIVE)
            *res = malloc_ai(port, htonl(0x00000000), socktype, proto);
        else
            *res = malloc_ai(port, htonl(0x7f000001), socktype, proto);
        if (*res)
            return 0;
        else
            return EAI_MEMORY;
    }
    if (inet_aton(hostname, &in)) {
        *res = malloc_ai(port, in.s_addr, socktype, proto);
        if (*res)
            return 0;
        else
            return EAI_MEMORY;
    }
    if (hints && hints->ai_flags & AI_NUMERICHOST)
        return EAI_NONAME;
    if ((hp = gethostbyname(hostname)) &&
        hp->h_name && hp->h_name[0] && hp->h_addr_list[0]) {
        for (i = 0; hp->h_addr_list[i]; i++) {
            if ((cur = malloc_ai(port,
                                ((struct in_addr *)hp->h_addr_list[i])->s_addr,
                                socktype, proto)) == NULL) {
                if (*res)
                    freeaddrinfo(*res);
                return EAI_MEMORY;
            }
            if (prev)
                prev->ai_next = cur;
            else
                *res = cur;
            prev = cur;
        }
        if (hints && hints->ai_flags & AI_CANONNAME && *res) {
            if (((*res)->ai_canonname = strdup(hp->h_name)) == NULL) {
                freeaddrinfo(*res);
                return EAI_MEMORY;
            }
        }
        return 0;
    }
    return EAI_NONAME;
}