getaddrinfo.c

Linux 2.6 内核上配置IPSec VPN 的工具

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 * 
 * 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. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``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 PROJECT OR CONTRIBUTORS 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.
 */

/*
 * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator.
 *
 * Issues to be discussed:
 * - Thread safe-ness must be checked.
 * - Return values.  There are nonstandard return values defined and used
 *   in the source code.  This is because RFC2553 is silent about which error
 *   code must be returned for which situation.
 * - PF_UNSPEC case would be handled in getipnodebyname() with the AI_ALL flag.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/sysctl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <netdb.h>
#include <resolv.h>
#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include <ctype.h>
#include <unistd.h>

#include "missing/addrinfo.h"

#if defined(__KAME__) && defined(INET6)
# define FAITH
#endif

#define SUCCESS 0
#define ANY 0
#define YES 1
#define NO  0

#ifdef FAITH
static int translate = NO;
static struct in6_addr faith_prefix = IN6ADDR_ANY_INIT;
#endif

static const char in_addrany[] = { 0, 0, 0, 0 };
static const char in6_addrany[] = {
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
static const char in_loopback[] = { 127, 0, 0, 1 }; 
static const char in6_loopback[] = {
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
};

struct sockinet {
	u_char	si_len;
	u_char	si_family;
	u_short	si_port;
};

static struct afd {
	int a_af;
	int a_addrlen;
	int a_socklen;
	int a_off;
	const char *a_addrany;
	const char *a_loopback;	
} afdl [] = {
#ifdef INET6
#define N_INET6 0
	{PF_INET6, sizeof(struct in6_addr),
	 sizeof(struct sockaddr_in6),
	 offsetof(struct sockaddr_in6, sin6_addr),
	 in6_addrany, in6_loopback},
#define N_INET  1
#else
#define N_INET  0
#endif
	{PF_INET, sizeof(struct in_addr),
	 sizeof(struct sockaddr_in),
	 offsetof(struct sockaddr_in, sin_addr),
	 in_addrany, in_loopback},
	{0, 0, 0, 0, NULL, NULL},
};

#ifdef INET6
#define PTON_MAX	16
#else
#define PTON_MAX	4
#endif


static int get_name __P((const char *, struct afd *,
			  struct addrinfo **, char *, struct addrinfo *,
			  int));
static int get_addr __P((const char *, int, struct addrinfo **,
			struct addrinfo *, int));
static int get_addr0 __P((const char *, int, struct addrinfo **,
			struct addrinfo *, int));
static int str_isnumber __P((const char *));
	
static char *ai_errlist[] = {
	"Success",
	"Address family for hostname not supported",	/* EAI_ADDRFAMILY */
	"Temporary failure in name resolution",		/* EAI_AGAIN      */
	"Invalid value for ai_flags",		       	/* EAI_BADFLAGS   */
	"Non-recoverable failure in name resolution", 	/* EAI_FAIL       */
	"ai_family not supported",			/* EAI_FAMILY     */
	"Memory allocation failure", 			/* EAI_MEMORY     */
	"No address associated with hostname", 		/* EAI_NODATA     */
	"hostname nor servname provided, or not known",/* EAI_NONAME     */
	"servname not supported for ai_socktype",	/* EAI_SERVICE    */
	"ai_socktype not supported", 			/* EAI_SOCKTYPE   */
	"System error returned in errno", 		/* EAI_SYSTEM     */
	"Invalid value for hints",			/* EAI_BADHINTS	  */
	"Resolved protocol is unknown",			/* EAI_PROTOCOL   */
	"Unknown error", 				/* EAI_MAX        */
};

#define GET_CANONNAME(ai, str) \
if (pai->ai_flags & AI_CANONNAME) {\
	if (((ai)->ai_canonname = (char *)malloc(strlen(str) + 1)) != NULL) {\
		strcpy((ai)->ai_canonname, (str));\
	} else {\
		error = EAI_MEMORY;\
		goto free;\
	}\
}

#define GET_AI(ai, afd, addr, port) {\
	char *p;\
	if (((ai) = (struct addrinfo *)malloc(sizeof(struct addrinfo) +\
					      ((afd)->a_socklen)))\
	    == NULL) {\
		error = EAI_MEMORY;\
		goto free;\
	}\
	memcpy(ai, pai, sizeof(struct addrinfo));\
	(ai)->ai_addr = (struct sockaddr *)((ai) + 1);\
	memset((ai)->ai_addr, 0, (afd)->a_socklen);\
	(ai)->ai_addr->sa_len = (ai)->ai_addrlen = (afd)->a_socklen;\
	(ai)->ai_addr->sa_family = (ai)->ai_family = (afd)->a_af;\
	((struct sockinet *)(ai)->ai_addr)->si_port = port;\
	p = (char *)((ai)->ai_addr);\
	memcpy(p + (afd)->a_off, (addr), (afd)->a_addrlen);\
}

#define ERR(err) { error = (err); goto bad; }

char *
gai_strerror(ecode)
	int ecode;
{
	if (ecode < 0 || ecode > EAI_MAX)
		ecode = EAI_MAX;
	return ai_errlist[ecode];
}

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

	do {
		next = ai->ai_next;
		if (ai->ai_canonname)
			free(ai->ai_canonname);
		/* no need to free(ai->ai_addr) */
		free(ai);
	} while ((ai = next) != NULL);
}

static int
str_isnumber(p)
	const char *p;
{
	char *q = (char *)p;
	while (*q) {
		if (! isdigit(*q))
			return NO;
		q++;
	}
	return YES;
}

int
getaddrinfo(hostname, servname, hints, res)
	const char *hostname, *servname;
	const struct addrinfo *hints;
	struct addrinfo **res;
{
	struct addrinfo sentinel;
	struct addrinfo *top = NULL;
	struct addrinfo *cur;
	int i, error = 0;
	char pton[PTON_MAX];
	struct addrinfo ai;
	struct addrinfo *pai;
	u_short port;

#ifdef FAITH
	static int firsttime = 1;

	if (firsttime) {
		/* translator hack */
		{
			char *q = getenv("GAI");
			if (q && inet_pton(AF_INET6, q, &faith_prefix) == 1)
				translate = YES;
		}
		firsttime = 0;
	}
#endif

	/* initialize file static vars */
	sentinel.ai_next = NULL;
	cur = &sentinel;
	pai = &ai;
	pai->ai_flags = 0;
	pai->ai_family = PF_UNSPEC;
	pai->ai_socktype = ANY;
	pai->ai_protocol = ANY;
	pai->ai_addrlen = 0;
	pai->ai_canonname = NULL;
	pai->ai_addr = NULL;
	pai->ai_next = NULL;
	port = ANY;
	
	if (hostname == NULL && servname == NULL)
		return EAI_NONAME;
	if (hints) {
		/* error check for hints */
		if (hints->ai_addrlen || hints->ai_canonname ||
		    hints->ai_addr || hints->ai_next)
			ERR(EAI_BADHINTS); /* xxx */
		if (hints->ai_flags & ~AI_MASK)
			ERR(EAI_BADFLAGS);
		switch (hints->ai_family) {
		case PF_UNSPEC:
		case PF_INET:
#ifdef INET6
		case PF_INET6:
#endif
			break;
		default:
			ERR(EAI_FAMILY);
		}
		memcpy(pai, hints, sizeof(*pai));
		switch (pai->ai_socktype) {
		case ANY:
			switch (pai->ai_protocol) {
			case ANY:
				break;
			case IPPROTO_UDP:
				pai->ai_socktype = SOCK_DGRAM;
				break;
			case IPPROTO_TCP:
				pai->ai_socktype = SOCK_STREAM;
				break;
			default:
				pai->ai_socktype = SOCK_RAW;
				break;
			}
			break;
		case SOCK_RAW:
			break;
		case SOCK_DGRAM:
			if (pai->ai_protocol != IPPROTO_UDP &&
			    pai->ai_protocol != ANY)
				ERR(EAI_BADHINTS);	/*xxx*/
			pai->ai_protocol = IPPROTO_UDP;
			break;
		case SOCK_STREAM:
			if (pai->ai_protocol != IPPROTO_TCP &&
			    pai->ai_protocol != ANY)
				ERR(EAI_BADHINTS);	/*xxx*/
			pai->ai_protocol = IPPROTO_TCP;
			break;
		default:
			ERR(EAI_SOCKTYPE);
			break;
		}
	}

	/*
	 * service port
	 */
	if (servname) {
		if (str_isnumber(servname)) {
			if (pai->ai_socktype == ANY) {
				/* caller accept *ANY* socktype */
				pai->ai_socktype = SOCK_DGRAM;
				pai->ai_protocol = IPPROTO_UDP;
			}
			port = htons(atoi(servname));
		} else {
			struct servent *sp;
			char *proto;

			proto = NULL;
			switch (pai->ai_socktype) {
			case ANY:
				proto = NULL;
				break;
			case SOCK_DGRAM:
				proto = "udp";
				break;
			case SOCK_STREAM:
				proto = "tcp";
				break;
			default:
				fprintf(stderr, "panic!\n");
				break;
			}
			if ((sp = getservbyname(servname, proto)) == NULL)
				ERR(EAI_SERVICE);
			port = sp->s_port;
			if (pai->ai_socktype == ANY) {
				if (strcmp(sp->s_proto, "udp") == 0) {
					pai->ai_socktype = SOCK_DGRAM;
					pai->ai_protocol = IPPROTO_UDP;
				} else if (strcmp(sp->s_proto, "tcp") == 0) {