gethostent.c

bind 9.3结合mysql数据库

/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 1996-1999 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#if !defined(LINT) && !defined(CODECENTER)
static const char rcsid[] = "$Id: gethostent.c,v 1.1.2.2.4.2 2004/03/17 01:49:40 marka Exp $";
#endif

/* Imports */

#include "port_before.h"

#if !defined(__BIND_NOSTATIC)

#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <net/if.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>

#include <ctype.h>
#include <errno.h>
#include <stdlib.h>
#include <netdb.h>
#include <resolv.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include <irs.h>
#include <isc/memcluster.h>

#include "port_after.h"

#include "irs_p.h"
#include "irs_data.h"

/* Definitions */

struct pvt {
	char *		aliases[1];
	char *		addrs[2];
	char		addr[NS_IN6ADDRSZ];
	char		name[NS_MAXDNAME + 1];
	struct hostent	host;
};

/* Forward */

static struct net_data *init(void);
static void		freepvt(struct net_data *);
static struct hostent  *fakeaddr(const char *, int, struct net_data *);


/* Public */

struct hostent *
gethostbyname(const char *name) {
	struct net_data *net_data = init();

	return (gethostbyname_p(name, net_data));
}

struct hostent *
gethostbyname2(const char *name, int af) {
	struct net_data *net_data = init();

	return (gethostbyname2_p(name, af, net_data));
}

struct hostent *
gethostbyaddr(const char *addr, int len, int af) {
	struct net_data *net_data = init();

	return (gethostbyaddr_p(addr, len, af, net_data));
}

struct hostent *
gethostent() {
	struct net_data *net_data = init();

	return (gethostent_p(net_data));
}

void
sethostent(int stayopen) {
	struct net_data *net_data = init();
	sethostent_p(stayopen, net_data);
}


void
endhostent() {
	struct net_data *net_data = init();
	endhostent_p(net_data);
}

/* Shared private. */

struct hostent *
gethostbyname_p(const char *name, struct net_data *net_data) {
	struct hostent *hp;

	if (!net_data)
		return (NULL);

	if (net_data->res->options & RES_USE_INET6) {
		hp = gethostbyname2_p(name, AF_INET6, net_data);
		if (hp)
			return (hp);
	}
	return (gethostbyname2_p(name, AF_INET, net_data));
}

struct hostent *
gethostbyname2_p(const char *name, int af, struct net_data *net_data) {
	struct irs_ho *ho;
	char tmp[NS_MAXDNAME];
	struct hostent *hp;
	const char *cp;
	char **hap;

	if (!net_data || !(ho = net_data->ho))
		return (NULL);
	if (net_data->ho_stayopen && net_data->ho_last &&
	    net_data->ho_last->h_addrtype == af) {
		if (ns_samename(name, net_data->ho_last->h_name) == 1)
			return (net_data->ho_last);
		for (hap = net_data->ho_last->h_aliases; hap && *hap; hap++)
			if (ns_samename(name, *hap) == 1)
				return (net_data->ho_last);
	}
	if (!strchr(name, '.') && (cp = res_hostalias(net_data->res, name,
						      tmp, sizeof tmp)))
		name = cp;
	if ((hp = fakeaddr(name, af, net_data)) != NULL)
		return (hp);
	net_data->ho_last = (*ho->byname2)(ho, name, af);
	if (!net_data->ho_stayopen)
		endhostent();
	return (net_data->ho_last);
}

struct hostent *
gethostbyaddr_p(const char *addr, int len, int af, struct net_data *net_data) {
	struct irs_ho *ho;
	char **hap;

	if (!net_data || !(ho = net_data->ho))
		return (NULL);
	if (net_data->ho_stayopen && net_data->ho_last &&
	    net_data->ho_last->h_length == len)
		for (hap = net_data->ho_last->h_addr_list;
		     hap && *hap;
		     hap++)
			if (!memcmp(addr, *hap, len))
				return (net_data->ho_last);
	net_data->ho_last = (*ho->byaddr)(ho, addr, len, af);
	if (!net_data->ho_stayopen)
		endhostent();
	return (net_data->ho_last);
}


struct hostent *
gethostent_p(struct net_data *net_data) {
	struct irs_ho *ho;
	struct hostent *hp;

	if (!net_data || !(ho = net_data->ho))
		return (NULL);
	while ((hp = (*ho->next)(ho)) != NULL &&
	       hp->h_addrtype == AF_INET6 &&
	       (net_data->res->options & RES_USE_INET6) == 0U)
		continue;
	net_data->ho_last = hp;
	return (net_data->ho_last);
}


void
sethostent_p(int stayopen, struct net_data *net_data) {
	struct irs_ho *ho;

	if (!net_data || !(ho = net_data->ho))
		return;
	freepvt(net_data);
	(*ho->rewind)(ho);
	net_data->ho_stayopen = (stayopen != 0);
	if (stayopen == 0)
		net_data_minimize(net_data);
}

void
endhostent_p(struct net_data *net_data) {
	struct irs_ho *ho;

	if ((net_data != NULL) && ((ho = net_data->ho) != NULL))
		(*ho->minimize)(ho);
}

#ifndef IN6_IS_ADDR_V4COMPAT
static const unsigned char in6addr_compat[12] = {
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
#define IN6_IS_ADDR_V4COMPAT(x) (!memcmp((x)->s6_addr, in6addr_compat, 12) && \
				 ((x)->s6_addr[12] != 0 || \
				  (x)->s6_addr[13] != 0 || \
				  (x)->s6_addr[14] != 0 || \
				   ((x)->s6_addr[15] != 0 && \
				    (x)->s6_addr[15] != 1)))
#endif
#ifndef IN6_IS_ADDR_V4MAPPED
#define IN6_IS_ADDR_V4MAPPED(x) (!memcmp((x)->s6_addr, in6addr_mapped, 12))
#endif

static const unsigned char in6addr_mapped[12] = {
	0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0xff, 0xff };

static int scan_interfaces(int *, int *);
static struct hostent *copyandmerge(struct hostent *, struct hostent *, int, int *);

/*
 *	Public functions
 */

/*
 *	AI_V4MAPPED + AF_INET6
 *	If no IPv6 address then a query for IPv4 and map returned values.
 *
 *	AI_ALL + AI_V4MAPPED + AF_INET6
 *	Return IPv6 and IPv4 mapped.
 *
 *	AI_ADDRCONFIG
 *	Only return IPv6 / IPv4 address if there is an interface of that
 *	type active.
 */

struct hostent *
getipnodebyname(const char *name, int af, int flags, int *error_num) {
	int have_v4 = 1, have_v6 = 1;
	struct in_addr in4;
	struct in6_addr in6;
	struct hostent he, *he1 = NULL, *he2 = NULL, *he3;
	int v4 = 0, v6 = 0;
	struct net_data *net_data = init();
	u_long options;
	int tmp_err;

	if (net_data == NULL) {
		*error_num = NO_RECOVERY;
		return (NULL);
	}

	/* If we care about active interfaces then check. */
	if ((flags & AI_ADDRCONFIG) != 0)
		if (scan_interfaces(&have_v4, &have_v6) == -1) {
			*error_num = NO_RECOVERY;
			return (NULL);
		}

	/* Check for literal address. */
	if ((v4 = inet_pton(AF_INET, name, &in4)) != 1)
		v6 = inet_pton(AF_INET6, name, &in6);

	/* Impossible combination? */
	 
	if ((af == AF_INET6 && (flags & AI_V4MAPPED) == 0 && v4 == 1) ||
	    (af == AF_INET && v6 == 1) ||
	    (have_v4 == 0 && v4 == 1) ||
	    (have_v6 == 0 && v6 == 1) ||
	    (have_v4 == 0 && af == AF_INET) ||
	    (have_v6 == 0 && af == AF_INET6)) {
		*error_num = HOST_NOT_FOUND;
		return (NULL);
	}

	/* Literal address? */
	if (v4 == 1 || v6 == 1) {
		char *addr_list[2];
		char *aliases[1];

		DE_CONST(name, he.h_name);
		he.h_addr_list = addr_list;
		he.h_addr_list[0] = (v4 == 1) ? (char *)&in4 : (char *)&in6;
		he.h_addr_list[1] = NULL;
		he.h_aliases = aliases;
		he.h_aliases[0] = NULL;
		he.h_length = (v4 == 1) ? INADDRSZ : IN6ADDRSZ;
		he.h_addrtype = (v4 == 1) ? AF_INET : AF_INET6;
		return (copyandmerge(&he, NULL, af, error_num));
	}

	options = net_data->res->options;
	net_data->res->options &= ~RES_USE_INET6;

	tmp_err = NO_RECOVERY;
	if (have_v6 && af == AF_INET6) {
		he2 = gethostbyname2_p(name, AF_INET6, net_data);
		if (he2 != NULL) {
			he1 = copyandmerge(he2, NULL, af, error_num);
			if (he1 == NULL)
				return (NULL);
			he2 = NULL;
		} else {
			tmp_err = net_data->res->res_h_errno;
		}
	}

	if (have_v4 &&
	    ((af == AF_INET) ||
	     (af == AF_INET6 && (flags & AI_V4MAPPED) != 0 &&
	      (he1 == NULL || (flags & AI_ALL) != 0)))) {
		he2 = gethostbyname2_p(name, AF_INET, net_data);
		if (he1 == NULL && he2 == NULL) {
			*error_num = net_data->res->res_h_errno;
			return (NULL);
		} 
	} else
		*error_num = tmp_err;

	net_data->res->options = options;

	he3 = copyandmerge(he1, he2, af, error_num);

	if (he1 != NULL)
		freehostent(he1);
	return (he3);
}

struct hostent *
getipnodebyaddr(const void *src, size_t len, int af, int *error_num) {
	struct hostent *he1, *he2;
	struct net_data *net_data = init();

	/* Sanity Checks. */
	if (src == NULL) {
		*error_num = NO_RECOVERY;
		return (NULL);
	}
		
	switch (af) {
	case AF_INET:
		if (len != (size_t)INADDRSZ) {
			*error_num = NO_RECOVERY;
			return (NULL);
		}
		break;
	case AF_INET6:
		if (len != (size_t)IN6ADDRSZ) {
			*error_num = NO_RECOVERY;
			return (NULL);
		}
		break;
	default:
		*error_num = NO_RECOVERY;
		return (NULL);
	}

	/*
	 * Lookup IPv4 and IPv4 mapped/compatible addresses
	 */
	if ((af == AF_INET6 &&
	     IN6_IS_ADDR_V4COMPAT((const struct in6_addr *)src)) ||
	    (af == AF_INET6 &&
	     IN6_IS_ADDR_V4MAPPED((const struct in6_addr *)src)) ||
	    (af == AF_INET)) {
		const char *cp = src;

		if (af == AF_INET6)
			cp += 12;
		he1 = gethostbyaddr_p(cp, 4, AF_INET, net_data);
		if (he1 == NULL) {
			*error_num = net_data->res->res_h_errno;
			return (NULL);
		}
		he2 = copyandmerge(he1, NULL, af, error_num);
		if (he2 == NULL)
			return (NULL);
		/*
		 * Restore original address if mapped/compatible.
		 */
		if (af == AF_INET6)
			memcpy(he1->h_addr, src, len);
		return (he2);
	}

	/*
	 * Lookup IPv6 address.
	 */
	if (memcmp((const struct in6_addr *)src, &in6addr_any, 16) == 0) {
		*error_num = HOST_NOT_FOUND;
		return (NULL);
	}

	he1 = gethostbyaddr_p(src, 16, AF_INET6, net_data);
	if (he1 == NULL) {
		*error_num = net_data->res->res_h_errno;
		return (NULL);
	}
	return (copyandmerge(he1, NULL, af, error_num));
}

void
freehostent(struct hostent *he) {
	char **cpp;
	int names = 1;
	int addresses = 1;

	memput(he->h_name, strlen(he->h_name) + 1);

	cpp = he->h_addr_list;
	while (*cpp != NULL) {
		memput(*cpp, (he->h_addrtype == AF_INET) ?
			     INADDRSZ : IN6ADDRSZ);
		*cpp = NULL;
		cpp++;
		addresses++;
	}

	cpp = he->h_aliases;
	while (*cpp != NULL) {
		memput(*cpp, strlen(*cpp) + 1);
		cpp++;
		names++;
	}

	memput(he->h_aliases, sizeof(char *) * (names));
	memput(he->h_addr_list, sizeof(char *) * (addresses));
	memput(he, sizeof *he);
}

/*
 * Private
 */

/*
 * Scan the interface table and set have_v4 and have_v6 depending
 * upon whether there are IPv4 and IPv6 interface addresses.
 *
 * Returns:
 *	0 on success
 *	-1 on failure.
 */

#if defined(SIOCGLIFCONF) && defined(SIOCGLIFADDR) && \
    !defined(IRIX_EMUL_IOCTL_SIOCGIFCONF) 

#ifdef __hpux
#define lifc_len iflc_len
#define lifc_buf iflc_buf
#define lifc_req iflc_req
#define LIFCONF if_laddrconf
#else
#define SETFAMILYFLAGS
#define LIFCONF lifconf
#endif
 
#ifdef __hpux
#define lifr_addr iflr_addr
#define lifr_name iflr_name
#define lifr_dstaddr iflr_dstaddr
#define lifr_flags iflr_flags
#define ss_family sa_family
#define LIFREQ if_laddrreq
#else
#define LIFREQ lifreq
#endif

static void
scan_interfaces6(int *have_v4, int *have_v6) {
	struct LIFCONF lifc;
	struct LIFREQ lifreq;
	struct in_addr in4;
	struct in6_addr in6;
	char *buf = NULL, *cp, *cplim;
	static unsigned int bufsiz = 4095;
	int s, cpsize, n;

	/* Get interface list from system. */
	if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) == -1)
		goto cleanup;

	/*
	 * Grow buffer until large enough to contain all interface
	 * descriptions.
	 */
	for (;;) {
		buf = memget(bufsiz);
		if (buf == NULL)
			goto cleanup;
#ifdef SETFAMILYFLAGS
		lifc.lifc_family = AF_UNSPEC;	/* request all families */
		lifc.lifc_flags = 0;
#endif
		lifc.lifc_len = bufsiz;
		lifc.lifc_buf = buf;
		if ((n = ioctl(s, SIOCGLIFCONF, (char *)&lifc)) != -1) {
			/*
			 * Some OS's just return what will fit rather
			 * than set EINVAL if the buffer is too small
			 * to fit all the interfaces in.  If 
			 * lifc.lifc_len is too near to the end of the
			 * buffer we will grow it just in case and
			 * retry.
			 */
			if (lifc.lifc_len + 2 * sizeof(lifreq) < bufsiz)
				break;
		}
		if ((n == -1) && errno != EINVAL)
			goto cleanup;

		if (bufsiz > 1000000)
			goto cleanup;

		memput(buf, bufsiz);
		bufsiz += 4096;
	}

	/* Parse system's interface list. */