gethostent.c

bind 9.3结合mysql数据库

	cplim = buf + lifc.lifc_len;    /* skip over if's with big ifr_addr's */
	for (cp = buf;
	     (*have_v4 == 0 || *have_v6 == 0) && cp < cplim;
	     cp += cpsize) {
		memcpy(&lifreq, cp, sizeof lifreq);
#ifdef HAVE_SA_LEN
#ifdef FIX_ZERO_SA_LEN
		if (lifreq.lifr_addr.sa_len == 0)
			lifreq.lifr_addr.sa_len = 16;
#endif
#ifdef HAVE_MINIMUM_IFREQ
		cpsize = sizeof lifreq;
		if (lifreq.lifr_addr.sa_len > sizeof (struct sockaddr))
			cpsize += (int)lifreq.lifr_addr.sa_len -
				(int)(sizeof (struct sockaddr));
#else
		cpsize = sizeof lifreq.lifr_name + lifreq.lifr_addr.sa_len;
#endif /* HAVE_MINIMUM_IFREQ */
#elif defined SIOCGIFCONF_ADDR
		cpsize = sizeof lifreq;
#else
		cpsize = sizeof lifreq.lifr_name;
		/* XXX maybe this should be a hard error? */
		if (ioctl(s, SIOCGLIFADDR, (char *)&lifreq) < 0)
			continue;
#endif
		switch (lifreq.lifr_addr.ss_family) {
		case AF_INET:
			if (*have_v4 == 0) {
				memcpy(&in4,
				       &((struct sockaddr_in *)
				       &lifreq.lifr_addr)->sin_addr,
				       sizeof in4);
				if (in4.s_addr == INADDR_ANY)
					break;
				n = ioctl(s, SIOCGLIFFLAGS, (char *)&lifreq);
				if (n < 0)
					break;
				if ((lifreq.lifr_flags & IFF_UP) == 0)
					break;
				*have_v4 = 1;
			} 
			break;
		case AF_INET6:
			if (*have_v6 == 0) {
				memcpy(&in6,
				       &((struct sockaddr_in6 *)
				       &lifreq.lifr_addr)->sin6_addr, sizeof in6);
				if (memcmp(&in6, &in6addr_any, sizeof in6) == 0)
					break;
				n = ioctl(s, SIOCGLIFFLAGS, (char *)&lifreq);
				if (n < 0)
					break;
				if ((lifreq.lifr_flags & IFF_UP) == 0)
					break;
				*have_v6 = 1;
			}
			break;
		}
	}
	if (buf != NULL)
		memput(buf, bufsiz);
	close(s);
	/* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
	return;
 cleanup:
	if (buf != NULL)
		memput(buf, bufsiz);
	if (s != -1)
		close(s);
	/* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
	return;
}
#endif

#ifdef __linux
#ifndef IF_NAMESIZE
# ifdef IFNAMSIZ
#  define IF_NAMESIZE  IFNAMSIZ
# else
#  define IF_NAMESIZE 16
# endif
#endif
static void
scan_linux6(int *have_v6) {
	FILE *proc = NULL;
	char address[33];
	char name[IF_NAMESIZE+1];
	int ifindex, prefix, flag3, flag4;
	
	proc = fopen("/proc/net/if_inet6", "r");
	if (proc == NULL)
		return;

	if (fscanf(proc, "%32[a-f0-9] %x %x %x %x %16s\n",
		   address, &ifindex, &prefix, &flag3, &flag4, name) == 6)
		*have_v6 = 1;
	fclose(proc);
	return;
}
#endif

static int
scan_interfaces(int *have_v4, int *have_v6) {
	struct ifconf ifc;
	union {
		char _pad[256];		/* leave space for IPv6 addresses */
		struct ifreq ifreq;
	} u;
	struct in_addr in4;
	struct in6_addr in6;
	char *buf = NULL, *cp, *cplim;
	static unsigned int bufsiz = 4095;
	int s, n;
	size_t cpsize;

	/* Set to zero.  Used as loop terminators below. */
	*have_v4 = *have_v6 = 0;

#if defined(SIOCGLIFCONF) && defined(SIOCGLIFADDR) && \
    !defined(IRIX_EMUL_IOCTL_SIOCGIFCONF) 
	/*
	 * Try to scan the interfaces using IPv6 ioctls().
	 */
	scan_interfaces6(have_v4, have_v6);
	if (*have_v4 != 0 && *have_v6 != 0)
		return (0);
#endif
#ifdef __linux
	scan_linux6(have_v6);
#endif

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

	/*
	 * Grow buffer until large enough to contain all interface
	 * descriptions.
	 */
	for (;;) {
		buf = memget(bufsiz);
		if (buf == NULL)
			goto err_ret;
		ifc.ifc_len = bufsiz;
		ifc.ifc_buf = buf;
#ifdef IRIX_EMUL_IOCTL_SIOCGIFCONF
		/*
		 * This is a fix for IRIX OS in which the call to ioctl with
		 * the flag SIOCGIFCONF may not return an entry for all the
		 * interfaces like most flavors of Unix.
		 */
		if (emul_ioctl(&ifc) >= 0)
			break;
#else
		if ((n = ioctl(s, SIOCGIFCONF, (char *)&ifc)) != -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 
			 * ifc.ifc_len is too near to the end of the
			 * buffer we will grow it just in case and
			 * retry.
			 */
			if (ifc.ifc_len + 2 * sizeof(u.ifreq) < bufsiz)
				break;
		}
#endif
		if ((n == -1) && errno != EINVAL)
			goto err_ret;

		if (bufsiz > 1000000)
			goto err_ret;

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

	/* Parse system's interface list. */
	cplim = buf + ifc.ifc_len;    /* skip over if's with big ifr_addr's */
	for (cp = buf;
	     (*have_v4 == 0 || *have_v6 == 0) && cp < cplim;
	     cp += cpsize) {
		memcpy(&u.ifreq, cp, sizeof u.ifreq);
#ifdef HAVE_SA_LEN
#ifdef FIX_ZERO_SA_LEN
		if (u.ifreq.ifr_addr.sa_len == 0)
			u.ifreq.ifr_addr.sa_len = 16;
#endif
#ifdef HAVE_MINIMUM_IFREQ
		cpsize = sizeof u.ifreq;
		if (u.ifreq.ifr_addr.sa_len > sizeof (struct sockaddr))
			cpsize += (int)u.ifreq.ifr_addr.sa_len -
				(int)(sizeof (struct sockaddr));
#else
		cpsize = sizeof u.ifreq.ifr_name + u.ifreq.ifr_addr.sa_len;
#endif /* HAVE_MINIMUM_IFREQ */
		if (cpsize > sizeof u.ifreq && cpsize <= sizeof u)
			memcpy(&u.ifreq, cp, cpsize);
#elif defined SIOCGIFCONF_ADDR
		cpsize = sizeof u.ifreq;
#else
		cpsize = sizeof u.ifreq.ifr_name;
		/* XXX maybe this should be a hard error? */
		if (ioctl(s, SIOCGIFADDR, (char *)&u.ifreq) < 0)
			continue;
#endif
		switch (u.ifreq.ifr_addr.sa_family) {
		case AF_INET:
			if (*have_v4 == 0) {
				memcpy(&in4,
				       &((struct sockaddr_in *)
				       &u.ifreq.ifr_addr)->sin_addr,
				       sizeof in4);
				if (in4.s_addr == INADDR_ANY)
					break;
				n = ioctl(s, SIOCGIFFLAGS, (char *)&u.ifreq);
				if (n < 0)
					break;
				if ((u.ifreq.ifr_flags & IFF_UP) == 0)
					break;
				*have_v4 = 1;
			} 
			break;
		case AF_INET6:
			if (*have_v6 == 0) {
				memcpy(&in6,
				       &((struct sockaddr_in6 *)
				       &u.ifreq.ifr_addr)->sin6_addr,
				       sizeof in6);
				if (memcmp(&in6, &in6addr_any, sizeof in6) == 0)
					break;
				n = ioctl(s, SIOCGIFFLAGS, (char *)&u.ifreq);
				if (n < 0)
					break;
				if ((u.ifreq.ifr_flags & IFF_UP) == 0)
					break;
				*have_v6 = 1;
			}
			break;
		}
	}
	if (buf != NULL)
		memput(buf, bufsiz);
	close(s);
	/* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
	return (0);
 err_ret:
	if (buf != NULL)
		memput(buf, bufsiz);
	if (s != -1)
		close(s);
	/* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
	return (-1);
}

static struct hostent *
copyandmerge(struct hostent *he1, struct hostent *he2, int af, int *error_num) {
	struct hostent *he = NULL;
	int addresses = 1;	/* NULL terminator */
	int names = 1;		/* NULL terminator */
	int len = 0;
	char **cpp, **npp;

	/*
	 * Work out array sizes;
	 */
	if (he1 != NULL) {
		cpp = he1->h_addr_list;
		while (*cpp != NULL) {
			addresses++;
			cpp++;
		}
		cpp = he1->h_aliases;
		while (*cpp != NULL) {
			names++;
			cpp++;
		}
	}

	if (he2 != NULL) {
		cpp = he2->h_addr_list;
		while (*cpp != NULL) {
			addresses++;
			cpp++;
		}
		if (he1 == NULL) {
			cpp = he2->h_aliases;
			while (*cpp != NULL) {
				names++;
				cpp++;
			}
		}
	}

	if (addresses == 1) {
		*error_num = NO_ADDRESS;
		return (NULL);
	}

	he = memget(sizeof *he);
	if (he == NULL)
		goto no_recovery;

	he->h_addr_list = memget(sizeof(char *) * (addresses));
	if (he->h_addr_list == NULL)
		goto cleanup0;
	memset(he->h_addr_list, 0, sizeof(char *) * (addresses));

	/* copy addresses */
	npp = he->h_addr_list;
	if (he1 != NULL) {
		cpp = he1->h_addr_list;
		while (*cpp != NULL) {
			*npp = memget((af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
			if (*npp == NULL)
				goto cleanup1;
			/* convert to mapped if required */
			if (af == AF_INET6 && he1->h_addrtype == AF_INET) {
				memcpy(*npp, in6addr_mapped,
				       sizeof in6addr_mapped);
				memcpy(*npp + sizeof in6addr_mapped, *cpp,
				       INADDRSZ);
			} else {
				memcpy(*npp, *cpp,
				       (af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
			}
			cpp++;
			npp++;
		}
	}

	if (he2 != NULL) {
		cpp = he2->h_addr_list;
		while (*cpp != NULL) {
			*npp = memget((af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
			if (*npp == NULL)
				goto cleanup1;
			/* convert to mapped if required */
			if (af == AF_INET6 && he2->h_addrtype == AF_INET) {
				memcpy(*npp, in6addr_mapped,
				       sizeof in6addr_mapped);
				memcpy(*npp + sizeof in6addr_mapped, *cpp,
				       INADDRSZ);
			} else {
				memcpy(*npp, *cpp,
				       (af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
			}
			cpp++;
			npp++;
		}
	}

	he->h_aliases = memget(sizeof(char *) * (names));
	if (he->h_aliases == NULL)
		goto cleanup1;
	memset(he->h_aliases, 0, sizeof(char *) * (names));

	/* copy aliases */
	npp = he->h_aliases;
	cpp = (he1 != NULL) ? he1->h_aliases : he2->h_aliases;
	while (*cpp != NULL) {
		len = strlen (*cpp) + 1;
		*npp = memget(len);
		if (*npp == NULL)
			goto cleanup2;
		strcpy(*npp, *cpp);
		npp++;
		cpp++;
	}

	/* copy hostname */
	he->h_name = memget(strlen((he1 != NULL) ?
			    he1->h_name : he2->h_name) + 1);
	if (he->h_name == NULL)
		goto cleanup2;
	strcpy(he->h_name, (he1 != NULL) ? he1->h_name : he2->h_name);

	/* set address type and length */
	he->h_addrtype = af;
	he->h_length = (af == AF_INET) ? INADDRSZ : IN6ADDRSZ;
	return(he);

 cleanup2:
	cpp = he->h_aliases;
	while (*cpp != NULL) {
		memput(*cpp, strlen(*cpp) + 1);
		cpp++;
	}
	memput(he->h_aliases, sizeof(char *) * (names));

 cleanup1:
	cpp = he->h_addr_list;
	while (*cpp != NULL) {
		memput(*cpp, (af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
		*cpp = NULL;
		cpp++;
	}
	memput(he->h_addr_list, sizeof(char *) * (addresses));

 cleanup0:
	memput(he, sizeof *he);

 no_recovery:
	*error_num = NO_RECOVERY;
	return (NULL);
}

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);
}

static void
freepvt(struct net_data *net_data) {
	if (net_data->ho_data) {
		free(net_data->ho_data);
		net_data->ho_data = NULL;
	}
}

static struct hostent *
fakeaddr(const char *name, int af, struct net_data *net_data) {
	struct pvt *pvt;

	freepvt(net_data);
	net_data->ho_data = malloc(sizeof (struct pvt));
	if (!net_data->ho_data) {
		errno = ENOMEM;
		RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
		return (NULL);
	}
	pvt = net_data->ho_data;
#ifndef __bsdi__
	/*
	 * Unlike its forebear(inet_aton), our friendly inet_pton() is strict
	 * in its interpretation of its input, and it will only return "1" if
	 * the input string is a formally valid(and thus unambiguous with
	 * respect to host names) internet address specification for this AF.
	 *
	 * This means "telnet 0xdeadbeef" and "telnet 127.1" are dead now.
	 */
	if (inet_pton(af, name, pvt->addr) != 1) {
#else
	/* BSDI XXX
	 * We put this back to inet_aton -- we really want the old behavior
	 * Long live 127.1...
	 */
	if ((af != AF_INET ||
	    inet_aton(name, (struct in_addr *)pvt->addr) != 1) &&
	    inet_pton(af, name, pvt->addr) != 1) {
#endif
		RES_SET_H_ERRNO(net_data->res, HOST_NOT_FOUND);
		return (NULL);
	}
	strncpy(pvt->name, name, NS_MAXDNAME);
	pvt->name[NS_MAXDNAME] = '\0';
	if (af == AF_INET && (net_data->res->options & RES_USE_INET6) != 0U) {
		map_v4v6_address(pvt->addr, pvt->addr);
		af = AF_INET6;
	}
	pvt->host.h_addrtype = af;
	switch(af) {
	case AF_INET:
		pvt->host.h_length = NS_INADDRSZ;
		break;
	case AF_INET6:
		pvt->host.h_length = NS_IN6ADDRSZ;
		break;
	default:
		errno = EAFNOSUPPORT;
		RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
		return (NULL);
	}
	pvt->host.h_name = pvt->name;
	pvt->host.h_aliases = pvt->aliases;
	pvt->aliases[0] = NULL;
	pvt->addrs[0] = (char *)pvt->addr;
	pvt->addrs[1] = NULL;
	pvt->host.h_addr_list = pvt->addrs;
	RES_SET_H_ERRNO(net_data->res, NETDB_SUCCESS);
	return (&pvt->host);
}

#ifdef grot	/* for future use in gethostbyaddr(), for "SUNSECURITY" */
	struct hostent *rhp;
	char **haddr;
	u_long old_options;
	char hname2[MAXDNAME+1];

	if (af == AF_INET) {
	    /*
	     * turn off search as the name should be absolute,
	     * 'localhost' should be matched by defnames
	     */
	    strncpy(hname2, hp->h_name, MAXDNAME);
	    hname2[MAXDNAME] = '\0';
	    old_options = net_data->res->options;
	    net_data->res->options &= ~RES_DNSRCH;
	    net_data->res->options |= RES_DEFNAMES;
	    if (!(rhp = gethostbyname(hname2))) {
		net_data->res->options = old_options;
		RES_SET_H_ERRNO(net_data->res, HOST_NOT_FOUND);
		return (NULL);
	    }
	    net_data->res->options = old_options;
	    for (haddr = rhp->h_addr_list; *haddr; haddr++)
		if (!memcmp(*haddr, addr, INADDRSZ))
			break;
	    if (!*haddr) {
		RES_SET_H_ERRNO(net_data->res, HOST_NOT_FOUND);
		return (NULL);
	    }
	}
#endif /* grot */

#endif /*__BIND_NOSTATIC*/