getaddrinfo.c

来自「Axis 221 camera embedded programing inte」· C语言 代码 · 共 874 行 · 第 1/2 页

    }
    else if (req->ai_socktype || req->ai_protocol)
    {
	st = alloca (sizeof (struct gaih_servtuple));
	st->next = NULL;
	st->socktype = tp->socktype;
	st->protocol = ((tp->protoflag & GAI_PROTO_PROTOANY)
			? req->ai_protocol : tp->protocol);
	st->port = 0;
    }
    else
    {
	/* 
	 * Neither socket type nor protocol is set.  Return all socket types
	 * we know about.
	 */
	struct gaih_servtuple **lastp = &st;
	for (++tp; tp->name[0]; ++tp)
	{
	    struct gaih_servtuple *newp;

	    newp = alloca (sizeof (struct gaih_servtuple));
	    newp->next = NULL;
	    newp->socktype = tp->socktype;
	    newp->protocol = tp->protocol;
	    newp->port = 0;

	    *lastp = newp;
	    lastp = &newp->next;
	}
    }

    if (name != NULL)
    {
	at = alloca (sizeof (struct gaih_addrtuple));

	at->family = AF_UNSPEC;
	at->scopeid = 0;
	at->next = NULL;

	if (inet_pton (AF_INET, name, at->addr) > 0)
	{
	    if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET || v4mapped)
		at->family = AF_INET;
	    else
		return -EAI_FAMILY;
	}

#if __UCLIBC_HAS_IPV6__
	if (at->family == AF_UNSPEC)
	{
	    char *namebuf = strdupa (name);
	    char *scope_delim;

	    scope_delim = strchr (namebuf, SCOPE_DELIMITER);
	    if (scope_delim != NULL)
		*scope_delim = '\0';

	    if (inet_pton (AF_INET6, namebuf, at->addr) > 0)
	    {
		if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET6)
		    at->family = AF_INET6;
		else
		    return -EAI_FAMILY;

		if (scope_delim != NULL)
		{
		    int try_numericscope = 0;
		    if (IN6_IS_ADDR_LINKLOCAL (at->addr)
			|| IN6_IS_ADDR_MC_LINKLOCAL (at->addr))
		    {
			at->scopeid = if_nametoindex (scope_delim + 1);
			if (at->scopeid == 0)
			    try_numericscope = 1;
		    }
		    else
			try_numericscope = 1;

		    if (try_numericscope != 0)
		    {
			char *end;
			assert (sizeof (uint32_t) <= sizeof (unsigned long));
			at->scopeid = (uint32_t) strtoul (scope_delim + 1, &end,
							  10);
			if (*end != '\0')
			    return GAIH_OKIFUNSPEC | -EAI_NONAME;
		    }
		}
	    }
	}
#endif

	if (at->family == AF_UNSPEC && (req->ai_flags & AI_NUMERICHOST) == 0)
	{
	    struct hostent *h;
	    struct gaih_addrtuple **pat = &at;
	    int no_data = 0;
	    int no_inet6_data;

	    /*
	     * If we are looking for both IPv4 and IPv6 address we don't want
	     * the lookup functions to automatically promote IPv4 addresses to
	     * IPv6 addresses.
	     */

#if __UCLIBC_HAS_IPV6__
	    if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET6)
		gethosts (AF_INET6, struct in6_addr);
#endif
	    no_inet6_data = no_data;

	    if (req->ai_family == AF_INET ||
		(!v4mapped && req->ai_family == AF_UNSPEC) ||
		(v4mapped && (no_inet6_data != 0 || (req->ai_flags & AI_ALL))))
		gethosts (AF_INET, struct in_addr);

	    if (no_data != 0 && no_inet6_data != 0)
	    {
		/* If both requests timed out report this. */
		if (no_data == EAI_AGAIN && no_inet6_data == EAI_AGAIN)
		    return -EAI_AGAIN;

		/*
		 * We made requests but they turned out no data.
		 * The name is known, though.
		 */
		return (GAIH_OKIFUNSPEC | -EAI_AGAIN);
	    }
	}

	if (at->family == AF_UNSPEC)
	    return (GAIH_OKIFUNSPEC | -EAI_NONAME);
    }
    else
    {
	struct gaih_addrtuple *atr;
	atr = at = alloca (sizeof (struct gaih_addrtuple));
	memset (at, '\0', sizeof (struct gaih_addrtuple));

	if (req->ai_family == 0)
	{
	    at->next = alloca (sizeof (struct gaih_addrtuple));
	    memset (at->next, '\0', sizeof (struct gaih_addrtuple));
	}

#if __UCLIBC_HAS_IPV6__
	if (req->ai_family == 0 || req->ai_family == AF_INET6)
	{
	    extern const struct in6_addr __in6addr_loopback;
	    at->family = AF_INET6;
	    if ((req->ai_flags & AI_PASSIVE) == 0)
		memcpy (at->addr, &__in6addr_loopback, sizeof (struct in6_addr));
	    atr = at->next;
	}
#endif

	if (req->ai_family == 0 || req->ai_family == AF_INET)
	{
	    atr->family = AF_INET;
	    if ((req->ai_flags & AI_PASSIVE) == 0)
		*(uint32_t *) atr->addr = htonl (INADDR_LOOPBACK);
	}
    }

    if (pai == NULL)
	return 0;

    {
	const char *c = NULL;
	struct gaih_servtuple *st2;
	struct gaih_addrtuple *at2 = at;
	size_t socklen, namelen;
	sa_family_t family;

	/*
	 * buffer is the size of an unformatted IPv6 address in
	 * printable format.
	 */
	char buffer[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"];

	while (at2 != NULL)
	{
	    if (req->ai_flags & AI_CANONNAME)
	    {
		struct hostent *h = NULL;

		int herrno;
		struct hostent th;
		size_t tmpbuflen = 512;
		char *tmpbuf;

		do
		{
		    tmpbuflen *= 2;
		    tmpbuf = alloca (tmpbuflen);

		    if (tmpbuf == NULL)
			return -EAI_MEMORY;

		    rc = gethostbyaddr_r (at2->addr,
					  ((at2->family == AF_INET6)
					   ? sizeof(struct in6_addr)
					   : sizeof(struct in_addr)),
					  at2->family, &th, tmpbuf, tmpbuflen,
					  &h, &herrno);

		}
		while (rc == errno && herrno == NETDB_INTERNAL);

		if (rc != 0 && herrno == NETDB_INTERNAL)
		{
		    __set_h_errno (herrno);
		    return -EAI_SYSTEM;
		}

		if (h == NULL)
		    c = inet_ntop (at2->family, at2->addr, buffer, sizeof(buffer));
		else
		    c = h->h_name;

		if (c == NULL)
		    return GAIH_OKIFUNSPEC | -EAI_NONAME;

		namelen = strlen (c) + 1;
	    }
	    else
		namelen = 0;

#if __UCLIBC_HAS_IPV6__
	    if (at2->family == AF_INET6 || v4mapped)
	    {
		family = AF_INET6;
		socklen = sizeof (struct sockaddr_in6);
	    }
	    else
#endif
	    {
		family = AF_INET;
		socklen = sizeof (struct sockaddr_in);
	    }

	    for (st2 = st; st2 != NULL; st2 = st2->next)
	    {
		*pai = malloc (sizeof (struct addrinfo) + socklen + namelen);
		if (*pai == NULL)
		    return -EAI_MEMORY;

		(*pai)->ai_flags = req->ai_flags;
		(*pai)->ai_family = family;
		(*pai)->ai_socktype = st2->socktype;
		(*pai)->ai_protocol = st2->protocol;
		(*pai)->ai_addrlen = socklen;
		(*pai)->ai_addr = (void *) (*pai) + sizeof(struct addrinfo);
#if SALEN
		(*pai)->ai_addr->sa_len = socklen;
#endif /* SALEN */
		(*pai)->ai_addr->sa_family = family;

#if __UCLIBC_HAS_IPV6__
		if (family == AF_INET6)
		{
		    struct sockaddr_in6 *sin6p =
			(struct sockaddr_in6 *) (*pai)->ai_addr;

		    sin6p->sin6_flowinfo = 0;
		    if (at2->family == AF_INET6)
		    {
			memcpy (&sin6p->sin6_addr,
				at2->addr, sizeof (struct in6_addr));
		    }
		    else
		    {
			sin6p->sin6_addr.s6_addr32[0] = 0;
			sin6p->sin6_addr.s6_addr32[1] = 0;
			sin6p->sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
			memcpy(&sin6p->sin6_addr.s6_addr32[3], 
			       at2->addr, sizeof (sin6p->sin6_addr.s6_addr32[3]));
		    }
		    sin6p->sin6_port = st2->port;
		    sin6p->sin6_scope_id = at2->scopeid;
		}
		else
#endif
		{
		    struct sockaddr_in *sinp =
			(struct sockaddr_in *) (*pai)->ai_addr;

		    memcpy (&sinp->sin_addr,
			    at2->addr, sizeof (struct in_addr));
		    sinp->sin_port = st2->port;
		    memset (sinp->sin_zero, '\0', sizeof (sinp->sin_zero));
		}

		if (c)
		{
		    (*pai)->ai_canonname = ((void *) (*pai) +
					    sizeof (struct addrinfo) + socklen);
		    strcpy ((*pai)->ai_canonname, c);
		}
		else
		    (*pai)->ai_canonname = NULL;

		(*pai)->ai_next = NULL;
		pai = &((*pai)->ai_next);
	    }

	    at2 = at2->next;
	}
    }
    return 0;
}

static struct gaih gaih[] =
{
#if __UCLIBC_HAS_IPV6__
    { PF_INET6, gaih_inet },
#endif
    { PF_INET, gaih_inet },
#if 0
    { PF_LOCAL, gaih_local },
#endif
    { PF_UNSPEC, NULL }
};

int
getaddrinfo (const char *name, const char *service,
	     const struct addrinfo *hints, struct addrinfo **pai)
{
    int i = 0, j = 0, last_i = 0;
    struct addrinfo *p = NULL, **end;
    struct gaih *g = gaih, *pg = NULL;
    struct gaih_service gaih_service, *pservice;

    if (name != NULL && name[0] == '*' && name[1] == 0)
	name = NULL;

    if (service != NULL && service[0] == '*' && service[1] == 0)
	service = NULL;

    if (name == NULL && service == NULL)
	return EAI_NONAME;

    if (hints == NULL)
	hints = &default_hints;

    if (hints->ai_flags & ~(AI_PASSIVE|AI_CANONNAME|AI_NUMERICHOST|
			    AI_ADDRCONFIG|AI_V4MAPPED|AI_ALL))
	return EAI_BADFLAGS;

    if ((hints->ai_flags & AI_CANONNAME) && name == NULL)
	return EAI_BADFLAGS;

    if (service && service[0])
    {
	char *c;
	gaih_service.name = service;
	gaih_service.num = strtoul (gaih_service.name, &c, 10);
	if (*c)
	    gaih_service.num = -1;
	else
	    /*
	     * Can't specify a numerical socket unless a protocol
	     * family was given.
	     */
	    if (hints->ai_socktype == 0 && hints->ai_protocol == 0)
		return EAI_SERVICE;
	pservice = &gaih_service;
    }
    else
	pservice = NULL;

    if (pai)
	end = &p;
    else
	end = NULL;

    while (g->gaih)
    {
	if (hints->ai_family == g->family || hints->ai_family == AF_UNSPEC)
	{
	    if ((hints->ai_flags & AI_ADDRCONFIG) && !addrconfig(g->family))
		continue;
	    j++;
	    if (pg == NULL || pg->gaih != g->gaih)
	    {
		pg = g;
		i = g->gaih (name, pservice, hints, end);
		if (i != 0)
		{
		    last_i = i;

		    if (hints->ai_family == AF_UNSPEC && (i & GAIH_OKIFUNSPEC))
			continue;

		    if (p)
			freeaddrinfo (p);

		    return -(i & GAIH_EAI);
		}
		if (end)
		    while(*end) end = &((*end)->ai_next);
	    }
	}
	++g;
    }

    if (j == 0)
	return EAI_FAMILY;

    if (p)
    {
	*pai = p;
	return 0;
    }

    if (pai == NULL && last_i == 0)
	return 0;

    if (p)
	freeaddrinfo (p);

    return last_i ? -(last_i & GAIH_EAI) : EAI_NONAME;
}

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

    while (ai != NULL)
    {
	p = ai;
	ai = ai->ai_next;
	free (p);
    }
}