getaddrinfo.c

bind 9.3结合mysql数据库

	if (!strchr(hostname, '.') &&
	    (cp = res_hostalias(net_data->res, hostname,
				tmp, sizeof(tmp))))
		hostname = cp;
	result = (*ho->addrinfo)(ho, hostname, pai);
	if (!net_data->ho_stayopen) {
		(*ho->minimize)(ho);
	}
	if (result == NULL) {
		int e = h_errno;

		switch(e) {
		case NETDB_INTERNAL:
			error = EAI_SYSTEM;
			break;
		case TRY_AGAIN:
			error = EAI_AGAIN;
			break;
		case NO_RECOVERY:
			error = EAI_FAIL;
			break;
		case HOST_NOT_FOUND:
		case NO_DATA:
			error = EAI_NONAME;
			break;
		default:
		case NETDB_SUCCESS: /* should be impossible... */
			error = EAI_NONAME;
			break;
		}
		goto free;
	}

	for (cur = result; cur; cur = cur->ai_next) {
		GET_PORT(cur, servname); /* XXX: redundant lookups... */
		/* canonname should already be filled. */
	}

	*res = result;

	return(0);

free:
	if (result)
		freeaddrinfo(result);
	return error;
}

static int
explore_copy(pai, src0, res)
	const struct addrinfo *pai;	/* seed */
	const struct addrinfo *src0;	/* source */
	struct addrinfo **res;
{
	int error;
	struct addrinfo sentinel, *cur;
	const struct addrinfo *src;

	error = 0;
	sentinel.ai_next = NULL;
	cur = &sentinel;

	for (src = src0; src != NULL; src = src->ai_next) {
		if (src->ai_family != pai->ai_family)
			continue;

		cur->ai_next = copy_ai(src);
		if (!cur->ai_next) {
			error = EAI_MEMORY;
			goto fail;
		}

		cur->ai_next->ai_socktype = pai->ai_socktype;
		cur->ai_next->ai_protocol = pai->ai_protocol;
		cur = cur->ai_next;
	}

	*res = sentinel.ai_next;
	return 0;

fail:
	freeaddrinfo(sentinel.ai_next);
	return error;
}

/*
 * hostname == NULL.
 * passive socket -> anyaddr (0.0.0.0 or ::)
 * non-passive socket -> localhost (127.0.0.1 or ::1)
 */
static int
explore_null(pai, servname, res)
	const struct addrinfo *pai;
	const char *servname;
	struct addrinfo **res;
{
	const struct afd *afd;
	struct addrinfo *cur;
	struct addrinfo sentinel;
	int error;

	*res = NULL;
	sentinel.ai_next = NULL;
	cur = &sentinel;

	afd = find_afd(pai->ai_family);
	if (afd == NULL)
		return 0;

	if (pai->ai_flags & AI_PASSIVE) {
		GET_AI(cur->ai_next, afd, afd->a_addrany);
		/* xxx meaningless?
		 * GET_CANONNAME(cur->ai_next, "anyaddr");
		 */
		GET_PORT(cur->ai_next, servname);
	} else {
		GET_AI(cur->ai_next, afd, afd->a_loopback);
		/* xxx meaningless?
		 * GET_CANONNAME(cur->ai_next, "localhost");
		 */
		GET_PORT(cur->ai_next, servname);
	}
	cur = cur->ai_next;

	*res = sentinel.ai_next;
	return 0;

free:
	if (sentinel.ai_next)
		freeaddrinfo(sentinel.ai_next);
	return error;
}

/*
 * numeric hostname
 */
static int
explore_numeric(pai, hostname, servname, res)
	const struct addrinfo *pai;
	const char *hostname;
	const char *servname;
	struct addrinfo **res;
{
	const struct afd *afd;
	struct addrinfo *cur;
	struct addrinfo sentinel;
	int error;
	char pton[PTON_MAX];

	*res = NULL;
	sentinel.ai_next = NULL;
	cur = &sentinel;

	afd = find_afd(pai->ai_family);
	if (afd == NULL)
		return 0;

	switch (afd->a_af) {
#if 0 /*X/Open spec*/
	case AF_INET:
		if (inet_aton(hostname, (struct in_addr *)pton) == 1) {
			if (pai->ai_family == afd->a_af ||
			    pai->ai_family == PF_UNSPEC /*?*/) {
				GET_AI(cur->ai_next, afd, pton);
				GET_PORT(cur->ai_next, servname);
				while (cur && cur->ai_next)
					cur = cur->ai_next;
			} else
				ERR(EAI_FAMILY);	/*xxx*/
		}
		break;
#endif
	default:
		if (inet_pton(afd->a_af, hostname, pton) == 1) {
			if (pai->ai_family == afd->a_af ||
			    pai->ai_family == PF_UNSPEC /*?*/) {
				GET_AI(cur->ai_next, afd, pton);
				GET_PORT(cur->ai_next, servname);
				while (cur && cur->ai_next)
					cur = cur->ai_next;
			} else
				ERR(EAI_FAMILY);	/*xxx*/
		}
		break;
	}

	*res = sentinel.ai_next;
	return 0;

free:
bad:
	if (sentinel.ai_next)
		freeaddrinfo(sentinel.ai_next);
	return error;
}

/*
 * numeric hostname with scope
 */
static int
explore_numeric_scope(pai, hostname, servname, res)
	const struct addrinfo *pai;
	const char *hostname;
	const char *servname;
	struct addrinfo **res;
{
#ifndef SCOPE_DELIMITER
	return explore_numeric(pai, hostname, servname, res);
#else
	const struct afd *afd;
	struct addrinfo *cur;
	int error;
	char *cp, *hostname2 = NULL, *scope, *addr;
	struct sockaddr_in6 *sin6;

	afd = find_afd(pai->ai_family);
	if (afd == NULL)
		return 0;

	if (!afd->a_scoped)
		return explore_numeric(pai, hostname, servname, res);

	cp = strchr(hostname, SCOPE_DELIMITER);
	if (cp == NULL)
		return explore_numeric(pai, hostname, servname, res);

	/*
	 * Handle special case of <scoped_address><delimiter><scope id>
	 */
	hostname2 = strdup(hostname);
	if (hostname2 == NULL)
		return EAI_MEMORY;
	/* terminate at the delimiter */
	hostname2[cp - hostname] = '\0';
	addr = hostname2;
	scope = cp + 1;

	error = explore_numeric(pai, addr, servname, res);
	if (error == 0) {
		u_int32_t scopeid = 0;

		for (cur = *res; cur; cur = cur->ai_next) {
			if (cur->ai_family != AF_INET6)
				continue;
			sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr;
			if (!ip6_str2scopeid(scope, sin6, &scopeid)) {
				free(hostname2);
				return(EAI_NONAME); /* XXX: is return OK? */
			}
#ifdef HAVE_SIN6_SCOPE_ID
			sin6->sin6_scope_id = scopeid;
#endif
		}
	}

	free(hostname2);

	return error;
#endif
}

static int
get_canonname(pai, ai, str)
	const struct addrinfo *pai;
	struct addrinfo *ai;
	const char *str;
{
	if ((pai->ai_flags & AI_CANONNAME) != 0) {
		ai->ai_canonname = (char *)malloc(strlen(str) + 1);
		if (ai->ai_canonname == NULL)
			return EAI_MEMORY;
		strcpy(ai->ai_canonname, str);
	}
	return 0;
}

static struct addrinfo *
get_ai(pai, afd, addr)
	const struct addrinfo *pai;
	const struct afd *afd;
	const char *addr;
{
	char *p;
	struct addrinfo *ai;

	ai = (struct addrinfo *)malloc(sizeof(struct addrinfo)
		+ (afd->a_socklen));
	if (ai == NULL)
		return NULL;

	memcpy(ai, pai, sizeof(struct addrinfo));
	ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
	memset(ai->ai_addr, 0, (size_t)afd->a_socklen);
#ifdef HAVE_SA_LEN
	ai->ai_addr->sa_len = afd->a_socklen;
#endif
	ai->ai_addrlen = afd->a_socklen;
	ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
	p = (char *)(void *)(ai->ai_addr);
	memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
	return ai;
}

/* XXX need to malloc() the same way we do from other functions! */
static struct addrinfo *
copy_ai(pai)
	const struct addrinfo *pai;
{
	struct addrinfo *ai;
	size_t l;

	l = sizeof(*ai) + pai->ai_addrlen;
	if ((ai = (struct addrinfo *)malloc(l)) == NULL)
		return NULL;
	memset(ai, 0, l);
	memcpy(ai, pai, sizeof(*ai));
	ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
	memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen);

	if (pai->ai_canonname) {
		l = strlen(pai->ai_canonname) + 1;
		if ((ai->ai_canonname = malloc(l)) == NULL) {
			free(ai);
			return NULL;
		}
		strcpy(ai->ai_canonname, pai->ai_canonname);	/* (checked) */
	} else {
		/* just to make sure */
		ai->ai_canonname = NULL;
	}

	ai->ai_next = NULL;

	return ai;
}

static int
get_portmatch(const struct addrinfo *ai, const char *servname) {

	/* get_port does not touch first argument. when matchonly == 1. */
	/* LINTED const cast */
	return get_port((const struct addrinfo *)ai, servname, 1);
}

static int
get_port(const struct addrinfo *ai, const char *servname, int matchonly) {
	const char *proto;
	struct servent *sp;
	int port;
	int allownumeric;

	if (servname == NULL)
		return 0;
	switch (ai->ai_family) {
	case AF_INET:
#ifdef AF_INET6
	case AF_INET6:
#endif
		break;
	default:
		return 0;
	}

	switch (ai->ai_socktype) {
	case SOCK_RAW:
		return EAI_SERVICE;
	case SOCK_DGRAM:
	case SOCK_STREAM:
		allownumeric = 1;
		break;
	case ANY:
		switch (ai->ai_family) {
		case AF_INET:
#ifdef AF_INET6
		case AF_INET6:
#endif
			allownumeric = 1;
			break;
		default:
			allownumeric = 0;
			break;
		}
		break;
	default:
		return EAI_SOCKTYPE;
	}

	if (str_isnumber(servname)) {
		if (!allownumeric)
			return EAI_SERVICE;
		port = atoi(servname);
		if (port < 0 || port > 65535)
			return EAI_SERVICE;
		port = htons(port);
	} else {
		switch (ai->ai_socktype) {
		case SOCK_DGRAM:
			proto = "udp";
			break;
		case SOCK_STREAM:
			proto = "tcp";
			break;
		default:
			proto = NULL;
			break;
		}

		if ((sp = getservbyname(servname, proto)) == NULL)
			return EAI_SERVICE;
		port = sp->s_port;
	}

	if (!matchonly) {
		switch (ai->ai_family) {
		case AF_INET:
			((struct sockaddr_in *)(void *)
			    ai->ai_addr)->sin_port = port;
			break;
		case AF_INET6:
			((struct sockaddr_in6 *)(void *)
			    ai->ai_addr)->sin6_port = port;
			break;
		}
	}

	return 0;
}

static const struct afd *
find_afd(af)
	int af;
{
	const struct afd *afd;

	if (af == PF_UNSPEC)
		return NULL;
	for (afd = afdl; afd->a_af; afd++) {
		if (afd->a_af == af)
			return afd;
	}
	return NULL;
}

/*
 * post-2553: AI_ADDRCONFIG check.  if we use getipnodeby* as backend, backend
 * will take care of it.
 * the semantics of AI_ADDRCONFIG is not defined well.  we are not sure
 * if the code is right or not.
 */
static int
addrconfig(af)
	int af;
{
	int s;

	/* XXX errno */
	s = socket(af, SOCK_DGRAM, 0);
	if (s < 0) {
		if (errno != EMFILE)
			return 0;
	} else
		close(s);
	return 1;
}

/* convert a string to a scope identifier. XXX: IPv6 specific */
static int
ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6,
		u_int32_t *scopeidp)
{
	u_int32_t scopeid;
	u_long lscopeid;
	struct in6_addr *a6 = &sin6->sin6_addr;
	char *ep;
	
	/* empty scopeid portion is invalid */
	if (*scope == '\0')
		return (0);

#ifdef USE_IFNAMELINKID
	if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) ||
	    IN6_IS_ADDR_MC_NODELOCAL(a6)) {
		/*
		 * Using interface names as link indices can be allowed
		 * only when we can assume a one-to-one mappings between
		 * links and interfaces.  See comments in getnameinfo.c.
		 */
		scopeid = if_nametoindex(scope);
		if (scopeid == 0)
			goto trynumeric;
		*scopeidp = scopeid;
		return (1);
	}
#endif

	/* still unclear about literal, allow numeric only - placeholder */
	if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6))
		goto trynumeric;
	if (IN6_IS_ADDR_MC_ORGLOCAL(a6))
		goto trynumeric;
	else
		goto trynumeric;	/* global */

	/* try to convert to a numeric id as a last resort */
trynumeric:
	errno = 0;
	lscopeid = strtoul(scope, &ep, 10);
	scopeid = lscopeid & 0xffffffff;
	if (errno == 0 && ep && *ep == '\0' && scopeid == lscopeid) {
		*scopeidp = scopeid;
		return (1);
	} else
		return (0);
}

struct addrinfo *
hostent2addrinfo(hp, pai)
	struct hostent *hp;
	const struct addrinfo *pai;
{
	int i, af, error = 0;
	char **aplist = NULL, *ap;
	struct addrinfo sentinel, *cur;
	const struct afd *afd;

	af = hp->h_addrtype;
	if (pai->ai_family != AF_UNSPEC && af != pai->ai_family)
		return(NULL);

	afd = find_afd(af);
	if (afd == NULL)
		return(NULL);

	aplist = hp->h_addr_list;

	memset(&sentinel, 0, sizeof(sentinel));
	cur = &sentinel;

	for (i = 0; (ap = aplist[i]) != NULL; i++) {
#if 0				/* the trick seems too much */
		af = hp->h_addr_list;
		if (af == AF_INET6 &&
		    IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) {
			af = AF_INET;
			ap = ap + sizeof(struct in6_addr)
				- sizeof(struct in_addr);
		}
		afd = find_afd(af);
		if (afd == NULL)
			continue;
#endif /* 0 */

		GET_AI(cur->ai_next, afd, ap);

		/* GET_PORT(cur->ai_next, servname); */
		if ((pai->ai_flags & AI_CANONNAME) != 0) {
			/*
			 * RFC2553 says that ai_canonname will be set only for
			 * the first element.  we do it for all the elements,
			 * just for convenience.
			 */
			GET_CANONNAME(cur->ai_next, hp->h_name);
		}
		while (cur && cur->ai_next) /* no need to loop, actually. */
			cur = cur->ai_next;
		continue;

	free:
		if (cur->ai_next)
			freeaddrinfo(cur->ai_next);
		cur->ai_next = NULL;
		/* continue, without tht pointer CUR advanced. */
	}

	return(sentinel.ai_next);
}

struct addrinfo *
addr2addrinfo(pai, cp)
	const struct addrinfo *pai;
	const char *cp;
{
	const struct afd *afd;

	afd = find_afd(pai->ai_family);
	if (afd == NULL)
		return(NULL);

	return(get_ai(pai, afd, cp));
}

static struct net_data *
init()
{
	struct net_data *net_data;

	if (!(net_data = net_data_init(NULL)))
		goto error;
	if (!net_data->ho) {
		net_data->ho = (*net_data->irs->ho_map)(net_data->irs);
		if (!net_data->ho || !net_data->res) {
error:
			errno = EIO;
			if (net_data && net_data->res)
				RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
			return (NULL);
		}

		(*net_data->ho->res_set)(net_data->ho, net_data->res, NULL);
	}

	return (net_data);
}