prnetdb.c

Netscape NSPR库源码

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 * 
 * The Original Code is the Netscape Portable Runtime (NSPR).
 * 
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation.  Portions created by Netscape are 
 * Copyright (C) 1998-2000 Netscape Communications Corporation.  All
 * Rights Reserved.
 * 
 * Contributor(s):
 * 
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU General Public License Version 2 or later (the
 * "GPL"), in which case the provisions of the GPL are applicable 
 * instead of those above.  If you wish to allow use of your 
 * version of this file only under the terms of the GPL and not to
 * allow others to use your version of this file under the MPL,
 * indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by
 * the GPL.  If you do not delete the provisions above, a recipient
 * may use your version of this file under either the MPL or the
 * GPL.
 */

#include "primpl.h"

#include <string.h>

/*
 * On Unix, the error code for gethostbyname() and gethostbyaddr()
 * is returned in the global variable h_errno, instead of the usual
 * errno.
 */
#if defined(XP_UNIX)
#if defined(_PR_NEED_H_ERRNO)
extern int h_errno;
#endif
#define _MD_GETHOST_ERRNO() h_errno
#else
#define _MD_GETHOST_ERRNO() _MD_ERRNO()
#endif

/*
 * The meaning of the macros related to gethostbyname, gethostbyaddr,
 * and gethostbyname2 is defined below.
 * - _PR_HAVE_THREADSAFE_GETHOST: the gethostbyXXX functions return
 *   the result in thread specific storage.  For example, AIX, HP-UX,
 *   and OSF1.
 * -  _PR_HAVE_GETHOST_R: have the gethostbyXXX_r functions. See next
 *   two macros.
 * - _PR_HAVE_GETHOST_R_INT: the gethostbyXXX_r functions return an
 *   int.  For example, Linux glibc.
 * - _PR_HAVE_GETHOST_R_POINTER: the gethostbyXXX_r functions return
 *   a struct hostent* pointer.  For example, Solaris and IRIX.
 */
#if defined(_PR_NO_PREEMPT) || defined(_PR_HAVE_GETHOST_R) \
    || defined(_PR_HAVE_THREADSAFE_GETHOST)
#define _PR_NO_DNS_LOCK
#endif

#if defined(_PR_NO_DNS_LOCK)
#define LOCK_DNS()
#define UNLOCK_DNS()
#else
PRLock *_pr_dnsLock = NULL;
#define LOCK_DNS() PR_Lock(_pr_dnsLock)
#define UNLOCK_DNS() PR_Unlock(_pr_dnsLock)
#endif  /* defined(_PR_NO_DNS_LOCK) */

/*
 * Some platforms have the reentrant getprotobyname_r() and
 * getprotobynumber_r().  However, they come in two flavors.
 * Some return a pointer to struct protoent, others return
 * an int.
 */
#if defined(XP_BEOS) && defined(BONE_VERSION)
#include <arpa/inet.h>  /* pick up define for inet_addr */
#include <sys/socket.h>
#define _PR_HAVE_GETPROTO_R
#define _PR_HAVE_GETPROTO_R_POINTER
#endif

#if defined(SOLARIS) || (defined(BSDI) && defined(_REENTRANT)) \
	|| (defined(LINUX) && defined(_REENTRANT) \
        && !(defined(__GLIBC__) && __GLIBC__ >= 2))
#define _PR_HAVE_GETPROTO_R
#define _PR_HAVE_GETPROTO_R_POINTER
#endif

#if defined(OSF1) \
        || defined(AIX4_3) || (defined(AIX) && defined(_THREAD_SAFE)) \
	|| (defined(HPUX10_10) && defined(_REENTRANT)) \
        || (defined(HPUX10_20) && defined(_REENTRANT))
#define _PR_HAVE_GETPROTO_R
#define _PR_HAVE_GETPROTO_R_INT
#endif

#if (defined(LINUX) && defined(__GLIBC__) && __GLIBC__ >= 2)
#define _PR_HAVE_GETPROTO_R
#define _PR_HAVE_5_ARG_GETPROTO_R
#endif

#if !defined(_PR_HAVE_GETPROTO_R)
PRLock* _getproto_lock = NULL;
#endif

#if defined(_PR_INET6_PROBE)
PR_EXTERN(PRBool) _pr_ipv6_is_present;
#endif

#define _PR_IN6_IS_ADDR_UNSPECIFIED(a)				\
				(((a)->pr_s6_addr32[0] == 0) &&	\
				((a)->pr_s6_addr32[1] == 0) &&		\
				((a)->pr_s6_addr32[2] == 0) &&		\
				((a)->pr_s6_addr32[3] == 0))
 
#define _PR_IN6_IS_ADDR_LOOPBACK(a)					\
               (((a)->pr_s6_addr32[0] == 0)	&&	\
               ((a)->pr_s6_addr32[1] == 0)		&&	\
               ((a)->pr_s6_addr32[2] == 0)		&&	\
               ((a)->pr_s6_addr[12] == 0)		&&	\
               ((a)->pr_s6_addr[13] == 0)		&&	\
               ((a)->pr_s6_addr[14] == 0)		&&	\
               ((a)->pr_s6_addr[15] == 0x1U))
 
const PRIPv6Addr _pr_in6addr_any =	{{{ 0, 0, 0, 0,
										0, 0, 0, 0,
										0, 0, 0, 0,
										0, 0, 0, 0 }}};

const PRIPv6Addr _pr_in6addr_loopback = {{{ 0, 0, 0, 0,
											0, 0, 0, 0,
											0, 0, 0, 0,
											0, 0, 0, 0x1U }}};
/*
 * The values at bytes 10 and 11 are compared using pointers to
 * 8-bit fields, and not 32-bit fields, to make the comparison work on
 * both big-endian and little-endian systems
 */

#define _PR_IN6_IS_ADDR_V4MAPPED(a)			\
		(((a)->pr_s6_addr32[0] == 0) 	&&	\
		((a)->pr_s6_addr32[1] == 0)	&&	\
		((a)->pr_s6_addr[8] == 0)		&&	\
		((a)->pr_s6_addr[9] == 0)		&&	\
		((a)->pr_s6_addr[10] == 0xff)	&&	\
		((a)->pr_s6_addr[11] == 0xff))

#define _PR_IN6_IS_ADDR_V4COMPAT(a)			\
		(((a)->pr_s6_addr32[0] == 0) &&	\
		((a)->pr_s6_addr32[1] == 0) &&		\
		((a)->pr_s6_addr32[2] == 0))

#define _PR_IN6_V4MAPPED_TO_IPADDR(a) ((a)->pr_s6_addr32[3])

#if defined(_PR_INET6) && defined(_PR_HAVE_GETHOSTBYNAME2)

/*
 * The _pr_QueryNetIfs() function finds out if the system has
 * IPv4 or IPv6 source addresses configured and sets _pr_have_inet_if
 * and _pr_have_inet6_if accordingly.
 *
 * We have an implementation using SIOCGIFCONF ioctl and a
 * default implementation that simply sets _pr_have_inet_if
 * and _pr_have_inet6_if to true.  A better implementation
 * would be to use the routing sockets (see Chapter 17 of
 * W. Richard Stevens' Unix Network Programming, Vol. 1, 2nd. Ed.)
 */

static PRBool _pr_have_inet_if = PR_FALSE;
static PRBool _pr_have_inet6_if = PR_FALSE;

#undef DEBUG_QUERY_IFS

#if defined(AIX)

/*
 * Use SIOCGIFCONF ioctl on platforms that don't have routing
 * sockets.  Warning: whether SIOCGIFCONF ioctl returns AF_INET6
 * network interfaces is not portable.
 *
 * The _pr_QueryNetIfs() function is derived from the code in
 * src/lib/libc/net/getifaddrs.c in BSD Unix and the code in
 * Section 16.6 of W. Richard Stevens' Unix Network Programming,
 * Vol. 1, 2nd. Ed.
 */

#include <sys/ioctl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <net/if.h>

#ifdef DEBUG_QUERY_IFS
static void
_pr_PrintIfreq(struct ifreq *ifr)
{
    PRNetAddr addr;
    struct sockaddr *sa;
    const char* family;
    char addrstr[64];

    sa = &ifr->ifr_addr;
    if (sa->sa_family == AF_INET) {
        struct sockaddr_in *sin = (struct sockaddr_in *)sa;
        family = "inet";
        memcpy(&addr.inet.ip, &sin->sin_addr, sizeof(sin->sin_addr));
    } else if (sa->sa_family == AF_INET6) {
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
        family = "inet6";
        memcpy(&addr.ipv6.ip, &sin6->sin6_addr, sizeof(sin6->sin6_addr));
    } else {
        return;  /* skip if not AF_INET or AF_INET6 */
    }
    addr.raw.family = sa->sa_family;
    PR_NetAddrToString(&addr, addrstr, sizeof(addrstr));
    printf("%s: %s %s\n", ifr->ifr_name, family, addrstr);
}
#endif

static void
_pr_QueryNetIfs(void)
{
    int sock;
    int rv;
    struct ifconf ifc;
    struct ifreq *ifr;
    struct ifreq *lifr;
    PRUint32 len, lastlen;
    char *buf;

    if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
        return;
    }

    /* Issue SIOCGIFCONF request in a loop. */
    lastlen = 0;
    len = 100 * sizeof(struct ifreq);  /* initial buffer size guess */
    for (;;) {
        buf = (char *)PR_Malloc(len);
        if (NULL == buf) {
            close(sock);
            return;
        }
        ifc.ifc_buf = buf;
        ifc.ifc_len = len;
        rv = ioctl(sock, SIOCGIFCONF, &ifc);
        if (rv < 0) {
            if (errno != EINVAL || lastlen != 0) {
                close(sock);
                PR_Free(buf);
                return;
            }
        } else {
            if (ifc.ifc_len == lastlen)
                break;  /* success, len has not changed */
            lastlen = ifc.ifc_len;
        }
        len += 10 * sizeof(struct ifreq);  /* increment */
        PR_Free(buf);
    }
    close(sock);

    ifr = ifc.ifc_req;
    lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len];

    while (ifr < lifr) {
        struct sockaddr *sa;
        int sa_len;

#ifdef DEBUG_QUERY_IFS
        _pr_PrintIfreq(ifr);
#endif
        sa = &ifr->ifr_addr;
        if (sa->sa_family == AF_INET) {
            struct sockaddr_in *sin = (struct sockaddr_in *) sa;
            if (sin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) {
                _pr_have_inet_if = PR_TRUE;
            } 
        } else if (sa->sa_family == AF_INET6) {
            struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) sa;
            if (!IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) {
                _pr_have_inet6_if = PR_TRUE;
            } 
        }

#ifdef _PR_HAVE_SOCKADDR_LEN
        sa_len = PR_MAX(sa->sa_len, sizeof(struct sockaddr));
#else
        switch (sa->sa_family) {
#ifdef AF_LINK
        case AF_LINK:
            sa_len = sizeof(struct sockaddr_dl);
            break;
#endif
        case AF_INET6:
            sa_len = sizeof(struct sockaddr_in6);
            break;
        default:
            sa_len = sizeof(struct sockaddr);
            break;
        }
#endif
        ifr = (struct ifreq *)(((char *)sa) + sa_len);
    }
    PR_Free(buf);
}

#else  /* default */

/*
 * Emulate the code in NSPR 4.2 or older.  PR_GetIPNodeByName behaves
 * as if the system had both IPv4 and IPv6 source addresses configured.
 */
static void
_pr_QueryNetIfs(void)
{
    _pr_have_inet_if = PR_TRUE;
    _pr_have_inet6_if = PR_TRUE;
}

#endif

#endif  /* _PR_INET6 && _PR_HAVE_GETHOSTBYNAME2 */

void _PR_InitNet(void)
{
#if defined(XP_UNIX)
#ifdef HAVE_NETCONFIG
	/*
	 * This one-liner prevents the endless re-open's and re-read's of
	 * /etc/netconfig on EACH and EVERY call to accept(), connect(), etc.
	 */
	 (void)setnetconfig();
#endif
#endif
#if !defined(_PR_NO_DNS_LOCK)
	_pr_dnsLock = PR_NewLock();
#endif
#if !defined(_PR_HAVE_GETPROTO_R)
	_getproto_lock = PR_NewLock();
#endif
#if defined(_PR_INET6) && defined(_PR_HAVE_GETHOSTBYNAME2)
	_pr_QueryNetIfs();
#ifdef DEBUG_QUERY_IFS
	if (_pr_have_inet_if)
		printf("Have IPv4 source address\n");
	if (_pr_have_inet6_if)
		printf("Have IPv6 source address\n");
#endif
#endif
}

void _PR_CleanupNet(void)
{
#if !defined(_PR_NO_DNS_LOCK)
    if (_pr_dnsLock) {
        PR_DestroyLock(_pr_dnsLock);
        _pr_dnsLock = NULL;
    }
#endif
#if !defined(_PR_HAVE_GETPROTO_R)
    if (_getproto_lock) {
        PR_DestroyLock(_getproto_lock);
        _getproto_lock = NULL;
    }
#endif
}

/*
** Allocate space from the buffer, aligning it to "align" before doing
** the allocation. "align" must be a power of 2.
*/
static char *Alloc(PRIntn amount, char **bufp, PRIntn *buflenp, PRIntn align)
{
	char *buf = *bufp;
	PRIntn buflen = *buflenp;

	if (align && ((long)buf & (align - 1))) {
		PRIntn skip = align - ((ptrdiff_t)buf & (align - 1));
		if (buflen < skip) {
			return 0;
		}
		buf += skip;
		buflen -= skip;
	}
	if (buflen < amount) {
		return 0;
	}
	*bufp = buf + amount;
	*buflenp = buflen - amount;
	return buf;
}

typedef enum _PRIPAddrConversion {
    _PRIPAddrNoConversion,
    _PRIPAddrIPv4Mapped,
    _PRIPAddrIPv4Compat
} _PRIPAddrConversion;

/*
** Convert an IPv4 address (v4) to an IPv4-mapped IPv6 address (v6).
*/
static void MakeIPv4MappedAddr(const char *v4, char *v6)
{
    memset(v6, 0, 10);
    memset(v6 + 10, 0xff, 2);
    memcpy(v6 + 12, v4, 4);
}

/*
** Convert an IPv4 address (v4) to an IPv4-compatible IPv6 address (v6).
*/
static void MakeIPv4CompatAddr(const char *v4, char *v6)
{
    memset(v6, 0, 12);
    memcpy(v6 + 12, v4, 4);
}

/*
** Copy a hostent, and all of the memory that it refers to into
** (hopefully) stacked buffers.
*/
static PRStatus CopyHostent(
    struct hostent *from,
    char **buf,
    PRIntn *bufsize,
    _PRIPAddrConversion conversion,
    PRHostEnt *to)
{
	PRIntn len, na;
	char **ap;