dns.c   [plain text]

/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
 * Reserved.  This file contains Original Code and/or Modifications of
 * Original Code as defined in and that are subject to the Apple Public
 * Source License Version 1.0 (the 'License').  You may not use this file
 * except in compliance with the License.  Please obtain a copy of the
 * License at http://www.apple.com/publicsource and read it before using
 * this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License."
 * 
 * @APPLE_LICENSE_HEADER_END@
 */

/*
 * Thread-safe DNS client library
 *
 * Copyright (c) 1998 Apple Computer Inc.  All Rights Reserved.
 * Written by Marc Majka
 */

#include <netinfo/ni.h>
#include <stdio.h>
#include <string.h>
#include <libc.h>
#include <unistd.h>
#include <netdb.h>
#include <stdarg.h>
#include <sys/syslog.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <ifaddrs.h>
#include <net/if.h>
#include <NetInfo/dns.h>
#include <NetInfo/system.h>
#include <NetInfo/syslock.h>

#define REPLY_BUF_SIZE 8192

#define NI_LOCATION_RESOLVER_OLD "/locations/resolver"
#define NI_LOCATION_RESOLVER "/domains"
#define FF_RESOLVE_CONF "/etc/resolv.conf"
#define FF_RESOLVER_DIR "/etc/resolver"

#define DNS_SERVER_TIMEOUT 2
#define DNS_SERVER_RETRIES 3

typedef enum
{
	PLX_DOMAIN,
	PLX_NAMESERVER,
	PLX_SEARCH,
	PLX_DEBUG,
	PLX_NDOTS,
	PLX_PROTOCOL,
	PLX_PORT,
	PLX_SORTLIST,
#ifdef DNS_EXCLUSION
	PLX_EXCLUDE,
	PLX_EXCLUSIVE,
#endif
	PLX_TIMEOUT,
	PLX_RETRIES,
	PLX_LFACTOR
} plindex;

#ifdef DNS_EXCLUSION
#define PLINDEX_COUNT 13
#else
#define PLINDEX_COUNT 11
#endif

typedef struct
{
	struct timeval send_time;
	struct timeval reply_time;
	u_int32_t server_index;
	u_int16_t xid;
	char *query_packet;
	u_int32_t query_length;
} dns_query_data_t;

dns_handle_t *dns_open_lock(char *, u_int32_t);

static syslock *_dnsLock = NULL;
static syslock *_logLock = NULL;

#ifdef _UNIX_BSD_43_
extern char *strdup(char *s);
#endif

static void
_time_subtract(struct timeval *t, u_int32_t sec, u_int32_t usec)
{
	if (t == NULL) return;

	if (sec > t->tv_sec) t->tv_sec = 0;
	else t->tv_sec -= sec;

	while (usec > t->tv_usec) 
	{
		if (t->tv_sec == 0)
		{
			t->tv_usec = 0;
			return;
		}

		t->tv_usec += 1000000;
		t->tv_sec -= 1;
	}

	t->tv_usec -= usec;
}

/* 
 * Compute x[n + 1] = (7^5 * x[n]) mod (2^31 - 1).
 * From "Random number generators: good ones are hard to find",
 * Park and Miller, Communications of the ACM, vol. 31, no. 10,
 * October 1988, p. 1195.
 */
static int 
dns_random() 
{
	static int did_init = 0;
	static unsigned int randseed = 1;
	int x, hi, lo, t;
	struct timeval tv;   
   
	if (did_init++ == 0)
	{
		gettimeofday(&tv, NULL);
		randseed = tv.tv_usec;
		if(randseed == 0) randseed = 1;
	}

	x = randseed; 
	hi = x / 127773;
	lo = x % 127773;
	t = 16807 * lo - 2836 * hi;
	if (t <= 0) t += 0x7fffffff;
	randseed = t;
	return t;
}

void
dns_log_msg(dns_handle_t *dns, int priority, char *message, ...)
{
	va_list ap;
	char *p, buf[2048];

	if (dns == NULL) return;

	if (_logLock == NULL)
	{
		_logLock = syslock_new(FALSE);
	}

	syslock_lock(_logLock);

	
	if (dns->log_dest & DNS_LOG_SYSLOG)
	{
		va_start(ap, message);
		vsyslog(priority, message, ap);
		va_end(ap);
	}

	if (dns->log_dest & DNS_LOG_FILE)
	{
		if (dns->log_title == NULL)
			fprintf(dns->log_file, "DNS Client: ");
		else
			fprintf(dns->log_file, "%s: ", dns->log_title);
	
		va_start(ap, message);
		vfprintf(dns->log_file, message, ap);
		fprintf(dns->log_file, "\n");
		fflush(dns->log_file);
		va_end(ap);
	}

	if (dns->log_dest & DNS_LOG_STDERR)
	{
		if (dns->log_title == NULL)
			fprintf(stderr, "DNS Client: ");
		else
			fprintf(stderr, "%s: ", dns->log_title);
	
		va_start(ap, message);
		vfprintf(stderr, message, ap);
		fprintf(stderr, "\n");
		va_end(ap);
	}

	if (dns->log_dest & DNS_LOG_CALLBACK)
	{
		if (dns->log_title == NULL)
		{
			sprintf(buf, "DNS Client: ");
			p = buf + 12;
		}
		else
		{
			sprintf(buf, "%s: ", dns->log_title);
			p = buf + strlen(dns->log_title) + 2;
		}
	
		va_start(ap, message);
		vsprintf(p, message, ap);
		va_end(ap);
		(*dns->log_callback)(priority, buf);
	}

	syslock_unlock(_logLock);
}

static void
_dns_lock(void)
{
	if (_dnsLock == NULL)
	{
		_dnsLock = syslock_new(FALSE);
	}

	syslock_lock(_dnsLock);
}

static void
_dns_unlock(void)
{
	syslock_unlock(_dnsLock);
}

void
dns_log_open_syslog(dns_handle_t *dns, char *title, int flags, int facility)
{
	if (dns == NULL) return;

	if (title == NULL) openlog("DNS Client", flags, facility);
	else openlog(title, flags, facility);
	dns->log_dest |= DNS_LOG_SYSLOG;
}

void
dns_log_close_syslog(dns_handle_t *dns)
{
	if (dns == NULL) return;
	dns->log_dest &= ~DNS_LOG_SYSLOG;
}

void
dns_log_close_file(dns_handle_t *dns)
{
	if (dns == NULL) return;
	if (dns->log_file != NULL) fclose(dns->log_file);
	dns->log_file = NULL;
	dns->log_dest &= ~DNS_LOG_FILE;
}

void
dns_log_open_file(dns_handle_t *dns, char *title, char *name, char *mode)
{
	if (dns == NULL) return;

	if (dns->log_file != NULL) dns_log_close_file(dns);

	dns->log_file = fopen(name, mode);
	if (title != NULL)
	{
		if (dns->log_title != NULL) free(dns->log_title);
		dns->log_title = strdup(title);
	}
}

void
dns_open_log(dns_handle_t *dns, char *title, int dest, FILE *file, int flags, int facility, int (*callback)(int, char *))
{
	if (dns == NULL) return;

	if (title != NULL)
	{
		if (dns->log_title != NULL) free(dns->log_title);
		dns->log_title = strdup(title);
	}

	dns->log_dest = dest;

	if (dest & DNS_LOG_FILE)
	{
		if (file == NULL) dns->log_dest &= ~DNS_LOG_FILE;
		else
		{
			if (dns->log_file != NULL) fclose(dns->log_file);
			dns->log_file = file;
		}
	}

	if (dest & DNS_LOG_SYSLOG)
	{
		dns_log_open_syslog(dns, title, flags, facility);
	}

	if (dest & DNS_LOG_CALLBACK)
	{
		if (callback == NULL) dns->log_dest &= ~DNS_LOG_CALLBACK;
		else dns->log_callback = callback;
	}
}

static u_int16_t
_dns_port(u_int32_t proto)
{
	/* Can't do getservbyname() since that would call lookupd! */
	return htons(DNS_SERVICE_PORT);
}

static int
key_match(char *line, char *keyword)
{
	int len;

	if (line == NULL) return 0;
	if (keyword == NULL) return 0;

	len = strlen(keyword);

	if ((strncasecmp(line, keyword, len) == 0) && ((line[len] == ' ') || (line[len] == '\t'))) return len;
	return 0;
}

static char *
get_val(char *line, int *off)
{
	char *s, *t;
	int i, len;

	if (line == NULL) return NULL;
	if (off == NULL) return NULL;
	
	/* skip whitespace */
	for (i = *off, len = 0; ((line[i] == ' ') || (line[i] == '\t')); i++, len++);
	*off += len;

	/* get chars */
	s = line + *off;
	for (len = 0; ((s[len] != '\0') && (s[len] != '\n') && (s[len] != ' ') && (s[len] != '\t')); len++);

	if (len == 0) return NULL;
	t = malloc(len + 1);
	memmove(t, s, len);
	t[len] = '\0';
	*off += len;
	return t;
}	
	
/*
 * Get resolver configuration from /etc/resolv.conf
 * or /etc/resolver/<<dom>>
 */
static ni_proplist *
_dns_file_init(char *dom)
{
	ni_proplist *p;
	ni_property *dp;
	ni_namelist *nl;
	char line[1024], *s, *dot, *hname;
	FILE *fp;
	int n;

	sprintf(line, "%s", FF_RESOLVE_CONF);
	fp = NULL;

	/* If dom is non-NULL, open /etc/resolver/dom */
	if (dom != NULL)
	{
		sprintf(line, "%s/%s", FF_RESOLVER_DIR, dom);
	}

	fp = fopen(line, "r");
	if (fp == NULL) return NULL;

	p = (ni_proplist *)malloc(sizeof(ni_proplist));
	NI_INIT(p);

	p->ni_proplist_len = PLINDEX_COUNT;

	dp = (ni_property *)malloc(p->ni_proplist_len * sizeof(ni_property));
	NI_INIT(dp);
	
	dp[PLX_DOMAIN].nip_name = strdup("domain");
	dp[PLX_DOMAIN].nip_val.ni_namelist_len = 0;
	dp[PLX_DOMAIN].nip_val.ni_namelist_val = NULL;

	/* If input "dom" arg is non-null, use it as the domain name */
	if (dom != NULL)
	{
		dp[PLX_DOMAIN].nip_val.ni_namelist_len = 1;
		dp[PLX_DOMAIN].nip_val.ni_namelist_val = (ni_name *)malloc(sizeof(char *));
		dp[PLX_DOMAIN].nip_val.ni_namelist_val[0] = strdup(dom);
	}

	dp[PLX_NAMESERVER].nip_name = strdup("nameserver");
	dp[PLX_NAMESERVER].nip_val.ni_namelist_len = 0;
	dp[PLX_NAMESERVER].nip_val.ni_namelist_val = NULL;
	
	dp[PLX_SEARCH].nip_name = strdup("search");
	dp[PLX_SEARCH].nip_val.ni_namelist_len = 0;
	dp[PLX_SEARCH].nip_val.ni_namelist_val = NULL;

	dp[PLX_DEBUG].nip_name = strdup("debug");
	dp[PLX_DEBUG].nip_val.ni_namelist_len = 0;
	dp[PLX_DEBUG].nip_val.ni_namelist_val = NULL;

	dp[PLX_NDOTS].nip_name = strdup("ndots");
	dp[PLX_NDOTS].nip_val.ni_namelist_len = 0;
	dp[PLX_NDOTS].nip_val.ni_namelist_val = NULL;

	dp[PLX_PROTOCOL].nip_name = strdup("protocol");
	dp[PLX_PROTOCOL].nip_val.ni_namelist_len = 0;
	dp[PLX_PROTOCOL].nip_val.ni_namelist_val = NULL;

	dp[PLX_PORT].nip_name = strdup("port");
	dp[PLX_PORT].nip_val.ni_namelist_len = 0;
	dp[PLX_PORT].nip_val.ni_namelist_val = NULL;

	dp[PLX_SORTLIST].nip_name = strdup("sortlist");
	dp[PLX_SORTLIST].nip_val.ni_namelist_len = 0;
	dp[PLX_SORTLIST].nip_val.ni_namelist_val = NULL;

#ifdef DNS_EXCLUSION
	dp[PLX_EXCLUDE].nip_name = strdup("exclude");
	dp[PLX_EXCLUDE].nip_val.ni_namelist_len = 0;
	dp[PLX_EXCLUDE].nip_val.ni_namelist_val = NULL;

	dp[PLX_EXCLUSIVE].nip_name = strdup("exclusive");
	dp[PLX_EXCLUSIVE].nip_val.ni_namelist_len = 0;
	dp[PLX_EXCLUSIVE].nip_val.ni_namelist_val = NULL;
#endif

	dp[PLX_TIMEOUT].nip_name = strdup("timeout");
	dp[PLX_TIMEOUT].nip_val.ni_namelist_len = 0;
	dp[PLX_TIMEOUT].nip_val.ni_namelist_val = NULL;

	dp[PLX_RETRIES].nip_name = strdup("retries");
	dp[PLX_RETRIES].nip_val.ni_namelist_len = 0;
	dp[PLX_RETRIES].nip_val.ni_namelist_val = NULL;

	dp[PLX_LFACTOR].nip_name = strdup("latency_factor");
	dp[PLX_LFACTOR].nip_val.ni_namelist_len = 0;
	dp[PLX_LFACTOR].nip_val.ni_namelist_val = NULL;

	p->ni_proplist_val = dp;

	for (fgets(line, 1024, fp); !feof(fp); fgets(line, 1024, fp))
	{
		if ((n = key_match(line, "domain")))
		{
			nl = &(dp[PLX_DOMAIN].nip_val);

			/* If already set, ignore this line */
			if (nl->ni_namelist_len != 0) continue;

			s = get_val(line, &n);
			if (s == NULL) continue;

			nl->ni_namelist_len = 1;
			nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
			nl->ni_namelist_val[0] = s;
		}
		
		else if ((n = key_match(line, "nameserver")))
		{
			nl = &(dp[PLX_NAMESERVER].nip_val);

			s = get_val(line, &n);
			if (s == NULL) continue;

			if (nl->ni_namelist_len == 0)
			{
				nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
			}
			else
			{
				nl->ni_namelist_val =
					(ni_name *)realloc(nl->ni_namelist_val,
						(nl->ni_namelist_len + 1) * sizeof(char *));
			}
			
			nl->ni_namelist_val[nl->ni_namelist_len] = s;
			nl->ni_namelist_len++;
		}

		else if ((n = key_match(line, "search")))
		{
			nl = &(dp[PLX_SEARCH].nip_val);

			while (NULL != (s = get_val(line, &n)))
			{
				if (nl->ni_namelist_len == 0)
				{
					nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
				}
				else
				{
					nl->ni_namelist_val =
						(ni_name *)realloc(nl->ni_namelist_val,
							(nl->ni_namelist_len + 1) * sizeof(char *));
				}
			
				nl->ni_namelist_val[nl->ni_namelist_len] = s;
				nl->ni_namelist_len++;
			}
		}

		else if ((n = key_match(line, "latency_factor")))
		{
			nl = &(dp[PLX_LFACTOR].nip_val);

			/* If already set, ignore this line */
			if (nl->ni_namelist_len != 0) continue;

			s = get_val(line, &n);
			if (s == NULL) continue;
	
			nl->ni_namelist_len = 1;
			nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
			nl->ni_namelist_val[0] = s;
		}

		else if ((n = key_match(line, "retries")))
		{
			nl = &(dp[PLX_RETRIES].nip_val);

			/* If already set, ignore this line */
			if (nl->ni_namelist_len != 0) continue;

			s = get_val(line, &n);
			if (s == NULL) continue;
	
			nl->ni_namelist_len = 1;
			nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
			nl->ni_namelist_val[0] = s;
		}

		else if ((n = key_match(line, "timeout")))
		{
			nl = &(dp[PLX_TIMEOUT].nip_val);

			/* If already set, ignore this line */
			if (nl->ni_namelist_len != 0) continue;

			s = get_val(line, &n);
			if (s == NULL) continue;
	
			nl->ni_namelist_len = 1;
			nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
			nl->ni_namelist_val[0] = s;
		}

		else if ((n = key_match(line, "port")))
		{
			nl = &(dp[PLX_PORT].nip_val);

			/* If already set, ignore this line */
			if (nl->ni_namelist_len != 0) continue;

			s = get_val(line, &n);
			if (s == NULL) continue;
	
			nl->ni_namelist_len = 1;
			nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
			nl->ni_namelist_val[0] = s;
		}

		else if ((n = key_match(line, "protocol")))
		{
			nl = &(dp[PLX_PROTOCOL].nip_val);

			/* If already set, ignore this line */
			if (nl->ni_namelist_len != 0) continue;

			s = get_val(line, &n);
			if (s == NULL) continue;
	
			nl->ni_namelist_len = 1;
			nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
			nl->ni_namelist_val[0] = s;
		}

		else if ((n = key_match(line, "sortlist")))
		{
			nl = &(dp[PLX_SORTLIST].nip_val);

			while (NULL != (s = get_val(line, &n)))
			{
				if (nl->ni_namelist_len == 0)
				{
					nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
				}
				else
				{
					nl->ni_namelist_val =
						(ni_name *)realloc(nl->ni_namelist_val,
							(nl->ni_namelist_len + 1) * sizeof(char *));
				}
			
				nl->ni_namelist_val[nl->ni_namelist_len] = s;
				nl->ni_namelist_len++;
			}
		}

#ifdef DNS_EXCLUSION
		else if ((n = key_match(line, "exclude")))
		{
			nl = &(dp[PLX_EXCLUDE].nip_val);

			while (NULL != (s = get_val(line, &n)))
			{
				if (nl->ni_namelist_len == 0)
				{
					nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
				}
				else
				{
					nl->ni_namelist_val =
						(ni_name *)realloc(nl->ni_namelist_val,
							(nl->ni_namelist_len + 1) * sizeof(char *));
				}
			
				nl->ni_namelist_val[nl->ni_namelist_len] = s;
				nl->ni_namelist_len++;
			}
		}
#endif

		else if ((n = key_match(line, "options")))
		{
			while (NULL != (s = get_val(line, &n)))
			{
				if (!strcasecmp(s, "debug"))
				{
					nl = &(dp[PLX_DEBUG].nip_val);
					if (nl->ni_namelist_len != 0)
					{
						free(nl->ni_namelist_val);
					}
					nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
					nl->ni_namelist_val[0] = strdup("YES");
					nl->ni_namelist_len = 1;
				}
				else if (!strncasecmp(s, "ndots:", 6))
				{
					nl = &(dp[PLX_NDOTS].nip_val);
					if (nl->ni_namelist_len != 0)
					{
						free(nl->ni_namelist_val);
					}
					nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
					nl->ni_namelist_val[0] = strdup(s + 6);
					nl->ni_namelist_len = 1;
				}
#ifdef DNS_EXCLUSION
				else if (!strncasecmp(s, "exclusive", 9))
				{
					nl = &(dp[PLX_EXCLUSIVE].nip_val);
					if (nl->ni_namelist_len != 0)
					{
						free(nl->ni_namelist_val);
					}
					nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
					nl->ni_namelist_val[0] = strdup("YES");
					nl->ni_namelist_len = 1;
				}
#endif
				else if (!strcasecmp(s, "tcp"))
				{
					nl = &(dp[PLX_PROTOCOL].nip_val);
					if (nl->ni_namelist_len != 0)
					{
						free(nl->ni_namelist_val);
					}
					nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
					nl->ni_namelist_val[0] = strdup(s);
					nl->ni_namelist_len = 1;
				}
			}
			free(s);
		}
	}

	fclose(fp);

	/*
	 * Default DEBUG to NO
	 */
	if (dp[PLX_DEBUG].nip_val.ni_namelist_len == 0)
	{
		dp[PLX_DEBUG].nip_val.ni_namelist_val = (ni_name *)malloc(sizeof(char *));
		dp[PLX_DEBUG].nip_val.ni_namelist_val[0] = strdup("NO");
		dp[PLX_DEBUG].nip_val.ni_namelist_len = 1;
	}

	/*
	 * Default protocol is udp
	 */
	if (dp[PLX_PROTOCOL].nip_val.ni_namelist_len == 0)
	{
		dp[PLX_PROTOCOL].nip_val.ni_namelist_val = (ni_name *)malloc(sizeof(char *));
		dp[PLX_PROTOCOL].nip_val.ni_namelist_val[0] = strdup("udp");
		dp[PLX_PROTOCOL].nip_val.ni_namelist_len = 1;
	}

	/*
	 * If no nameserver addresses are set, return NULL.
	 */
	if (dp[PLX_NAMESERVER].nip_val.ni_namelist_len == 0)
	{
		ni_proplist_free(p);
		free(p);
		return NULL;
	}

	if (dp[PLX_DOMAIN].nip_val.ni_namelist_len == 0)
	{
		/*
		 * domain is unset
		 * Else if hostname has a ".", use trailing part as a domain.
		 * Else assume root.
		 */
		s = ".";
		hname = NULL;
		if (hname != NULL)
		{
			dot = strchr(hname, '.');
			if (dot != NULL) s = dot + 1;
		}

		nl = &(dp[PLX_DOMAIN].nip_val);
			
		nl->ni_namelist_len = 1;
		nl->ni_namelist_val = (ni_name *)malloc(sizeof(char *));
		nl->ni_namelist_val[0] = strdup(s);
	}

	return p;
}

/*
 * Utility to break up sortlist entries into addresses and netmasks
 */
static int
_dns_parse_network(char *s, u_int32_t *addr, u_int32_t *mask)
{
	char *p, *q;
	u_int32_t v, i, m, bits;

	if (s == NULL) return 1;

	p = strchr(s, '/');
	if (p != NULL) *p++ = '\0';
	
	*addr = inet_addr(s);
	if (*addr == (u_int32_t)-1) return 1;
	if (p == NULL)
	{
		if (IN_CLASSA(*addr)) *mask = IN_CLASSA_NET;
		else if (IN_CLASSB(*addr)) *mask = IN_CLASSB_NET;
		else if (IN_CLASSC(*addr)) *mask = IN_CLASSC_NET;
		else return 1;
		return 0;
	}

	*(p - 1) = '/';

	q = strchr(p, '.');
	if (q == NULL)
	{
		bits = atoi(p);
		if (bits == 0) return 1;
		if (bits > 32) bits = 32;

		bits = 33 - bits;
		m = 0;
		for (i = 1, v = 1; i < bits; i++, v *= 2) m |= v;
		*mask = ~m;
		return 0;
	}
	
	*mask = inet_addr(p);
	if (*mask == (u_int32_t)-1) return 1;
	return 0;
}

/*
 * Create a DNS client handle
 */
dns_handle_t *
dns_open_lock(char *dom, u_int32_t lockit)
{
	dns_handle_t *dns;
	ni_proplist *p;
	ni_index dx, nx, where;
	int i, len, s, proto, stype, lfactor;
	unsigned long addr;
	u_int16_t port;
	u_int32_t sa, sm;
	char *str;

	if (lockit != 0) _dns_lock();

	p = _dns_file_init(dom);
	if (p == NULL)
	{
		if (lockit != 0) _dns_unlock();
		return NULL;
	}

	dx = ni_proplist_match(*p, "domain", NULL);
	if (dx == NI_INDEX_NULL)
	{
		ni_proplist_free(p);
		free(p);
		if (lockit != 0) _dns_unlock();
		return NULL;
	}

	if (p->ni_proplist_val[dx].nip_val.ni_namelist_len == 0)
	{
		ni_proplist_free(p);
		free(p);
		if (lockit != 0) _dns_unlock();
		return NULL;
	}

	nx = ni_proplist_match(*p, "nameserver", NULL);
	if (nx == NI_INDEX_NULL)
	{
		ni_proplist_free(p);
		free(p);
		if (lockit != 0) _dns_unlock();
		return NULL;
	}

	len = p->ni_proplist_val[nx].nip_val.ni_namelist_len;
	if (len == 0)
	{
		ni_proplist_free(p);
		free(p);
		if (lockit != 0) _dns_unlock();
		return NULL;
	}

	lfactor = 10;
	where = ni_proplist_match(*p, "latency_factor", NULL);
	if (where != NI_INDEX_NULL)
	{
		if (p->ni_proplist_val[where].nip_val.ni_namelist_len != 0)
		{
			lfactor = atoi(p->ni_proplist_val[where].nip_val.ni_namelist_val[0]);
			if (lfactor <= 0) lfactor = 10;
			if (lfactor > 100) lfactor = 100;
		}
	}

	proto = IPPROTO_UDP;
	stype = SOCK_DGRAM;
	where = ni_proplist_match(*p, "protocol", NULL);
	if (where != NI_INDEX_NULL)
	{
		if (p->ni_proplist_val[where].nip_val.ni_namelist_len != 0)
		{
			str = p->ni_proplist_val[where].nip_val.ni_namelist_val[0];
			if (!strcasecmp(str, "tcp")) proto = IPPROTO_TCP;
		}
	}

	if (proto == IPPROTO_TCP) stype = SOCK_STREAM;
	
	s = socket(AF_INET, stype, proto);	
	if (s < 0)
	{
		ni_proplist_free(p);
		free(p);
		if (lockit != 0) _dns_unlock();
		return NULL;
	}

	dns = (dns_handle_t *)malloc(sizeof(dns_handle_t));
	memset(dns, 0, sizeof(dns_handle_t));

	dns->sock = s;
	dns->protocol = proto;
	dns->sockstate = DNS_SOCK_UDP;
	if (proto == IPPROTO_TCP) dns->sockstate = DNS_SOCK_TCP_UNCONNECTED;

	dns->xid = dns_random() % 0x10000;

	dns->ias_dots = 1;
	where = ni_proplist_match(*p, "ndots", NULL);
	if ((where != NI_INDEX_NULL) &&
		(p->ni_proplist_val[where].nip_val.ni_namelist_len > 0))
	dns->ias_dots = atoi(p->ni_proplist_val[where].nip_val.ni_namelist_val[0]);

#ifdef DNS_EXCLUSION
	dns->exclusive = 0;
	where = ni_proplist_match(*p, "exclusive", NULL);
	if ((where != NI_INDEX_NULL) && (p->ni_proplist_val[where].nip_val.ni_namelist_len > 0))
	{
		if (!strcasecmp(p->ni_proplist_val[where].nip_val.ni_namelist_val[0], "YES")) dns->exclusive = 1;	
	}
#endif

	port = _dns_port(dns->protocol);

	/* LOCAL.ARPA USED HERE */
	if ((dom != NULL) && (!strcasecmp(dom, LOCAL_DOMAIN_STRING)))
	{
		port = htons(DNS_LOCAL_DOMAIN_SERVICE_PORT);
	}

	where = ni_proplist_match(*p, "port", NULL);
	if (where != NI_INDEX_NULL)
	{
		if (p->ni_proplist_val[where].nip_val.ni_namelist_len != 0)
		{
			port = atoi(p->ni_proplist_val[where].nip_val.ni_namelist_val[0]);
			port = htons(port);
		}
	}
	
	dns->selected_server = 0;
	dns->server_count = len;
	dns->server = (struct sockaddr_in *)malloc(len * sizeof(struct sockaddr_in));
	dns->server_latency = (u_int32_t *)malloc(len * sizeof(u_int32_t));
	for (i = 0; i < len; i++)
	{
		addr = inet_addr(p->ni_proplist_val[nx].nip_val.ni_namelist_val[i]);
		dns->server[i].sin_addr.s_addr = addr;
		dns->server[i].sin_family = AF_INET;
		dns->server[i].sin_port = port;
		dns->server_latency[i] = 0;
#ifdef _UNIX_BSD_44_
		dns->server[i].sin_len = sizeof(struct sockaddr_in);
#endif
	}

	dns->server_timeout.tv_sec = 0;
	dns->server_timeout.tv_usec = 0;

	dns->server_retries = DNS_SERVER_RETRIES;
	where = ni_proplist_match(*p, "retries", NULL);
	if (where != NI_INDEX_NULL)
	{
		if (p->ni_proplist_val[where].nip_val.ni_namelist_len != 0)
		{
			dns->server_retries = atoi(p->ni_proplist_val[where].nip_val.ni_namelist_val[0]);
		}
	}

	dns->timeout.tv_sec = 0;
	dns->timeout.tv_usec = 0;

	/* LOCAL.ARPA USED HERE */
	if (!strcasecmp(p->ni_proplist_val[dx].nip_val.ni_namelist_val[0], LOCAL_DOMAIN_STRING))
	{
		dns->server_timeout.tv_sec = 0;
		dns->server_timeout.tv_usec = 250000;
	}

	where = ni_proplist_match(*p, "timeout", NULL);
	if (where != NI_INDEX_NULL)
	{
		if (p->ni_proplist_val[where].nip_val.ni_namelist_len != 0)
		{
			dns->timeout.tv_sec = atoi(p->ni_proplist_val[where].nip_val.ni_namelist_val[0]);
			dns_set_timeout(dns, &(dns->timeout));
		}
	}

	dns->latency_adjust = lfactor;

	dns->domain = strdup(p->ni_proplist_val[dx].nip_val.ni_namelist_val[0]);

	dns->search_count = 0;
	dns->search = NULL;
	where = ni_proplist_match(*p, "search", NULL);
	if (where != NI_INDEX_NULL)
	{
		dns->search_count = p->ni_proplist_val[where].nip_val.ni_namelist_len;

		if (dns->search_count > 0) dns->search = (char **)malloc(dns->search_count * sizeof(char *));
		for (i = 0; i < dns->search_count; i++)
		{
			dns->search[i] = strdup(p->ni_proplist_val[where].nip_val.ni_namelist_val[i]);
		}
	}

#ifdef DNS_EXCLUSION
	dns->exclude_count = 0;
	dns->exclude = NULL;
	where = ni_proplist_match(*p, "exclude", NULL);
	if (where != NI_INDEX_NULL)
	{
		dns->exclude_count = p->ni_proplist_val[where].nip_val.ni_namelist_len;
		if (dns->exclude_count > 0) dns->exclude = (char **)malloc(dns->exclude_count * sizeof(char *));
		for (i = 0; i < dns->exclude_count; i++)
		{
			dns->exclude[i] = strdup(p->ni_proplist_val[where].nip_val.ni_namelist_val[i]);
		}
	}
#endif

	dns->sort_count = 0;
	where = ni_proplist_match(*p, "sortlist", NULL);
	if (where != NI_INDEX_NULL)
	{
		len = p->ni_proplist_val[where].nip_val.ni_namelist_len;
		for (i = 0; i < len; i++)
		{
			str = p->ni_proplist_val[where].nip_val.ni_namelist_val[i];
			if (_dns_parse_network(str, &sa, &sm) == 0)
			{
				if (dns->sort_count == 0)
				{
					dns->sort_addr = (u_int32_t *)malloc(sizeof(u_int32_t));
					dns->sort_mask = (u_int32_t *)malloc(sizeof(u_int32_t));
				}
				else
				{
					dns->sort_addr = (u_int32_t *)realloc((char *)dns->sort_addr,
						(dns->sort_count + 1) * sizeof(u_int32_t));
					dns->sort_mask = (u_int32_t *)realloc((char *)dns->sort_mask,
						(dns->sort_count + 1) * sizeof(u_int32_t));
				}
				dns->sort_addr[dns->sort_count] = sa & sm;
				dns->sort_mask[dns->sort_count] = sm;
				dns->sort_count++;
			}
		}
	}

	ni_proplist_free(p);
	free(p);

	dns->log_dest = DNS_LOG_NONE;
	dns->log_file = NULL;
	dns->log_title = NULL;

	if (lockit != 0) _dns_unlock();
	return dns;
}

dns_handle_t *
dns_open(char *dom)
{
	return dns_open_lock(dom, 1);
}

dns_handle_t *
dns_connect(char *name, struct sockaddr_in *addr)
{
	dns_handle_t *dns;
	int s;

	_dns_lock();

	s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
	if (s < 0)
	{
		_dns_unlock();
		return NULL;
	}

	dns = (dns_handle_t *)malloc(sizeof(dns_handle_t));
	memset(dns, 0, sizeof(dns_handle_t));

	dns->sock = s;
	dns->protocol = IPPROTO_UDP;
	dns->sockstate = DNS_SOCK_UDP;
	
	dns->xid = dns_random() % 0x10000;

	dns->ias_dots = 1;
	dns->selected_server = 0;
	dns->server_count = 1;
	dns->server = (struct sockaddr_in *)malloc(sizeof(struct sockaddr_in));
	dns->server[0].sin_addr.s_addr = addr->sin_addr.s_addr;
	dns->server[0].sin_family = AF_INET;
	dns->server[0].sin_port = addr->sin_port;
#ifndef _NO_SOCKADDR_LENGTH_
	dns->server[0].sin_len = sizeof(struct sockaddr_in);
#endif

	dns->server_timeout.tv_sec = 0;
	dns->server_timeout.tv_usec = 0;

	dns->server_retries = DNS_SERVER_RETRIES;

	dns->timeout.tv_sec = 0;
	dns->timeout.tv_usec = 0;

	dns->domain = strdup(name);
	dns->search_count = 0;

	dns->log_dest = 0;
	dns->log_file = NULL;
	dns->log_title = NULL;

	_dns_unlock();
	return dns;
}

void
dns_shutdown(void)
{
	if (_dnsLock != NULL) syslock_free(_dnsLock);
	_dnsLock = NULL;
	if (_logLock != NULL) syslock_free(_logLock);
	_logLock = NULL;
}

void
dns_add_server(dns_handle_t *dns, struct sockaddr_in *s)
{
	u_int32_t i;

	if (dns == NULL) return;
	if (s == NULL) return;
	
	if (dns->server_count == 0)
		dns->server = (struct sockaddr_in *)malloc(sizeof(struct sockaddr_in));
	else
		dns->server = (struct sockaddr_in *)realloc((char *)dns->server,
			(dns->server_count + 1) * sizeof(struct sockaddr_in));

	i = dns->server_count;
	dns->server[i].sin_addr.s_addr = s->sin_addr.s_addr;
	dns->server[i].sin_port = s->sin_port;
	dns->server[i].sin_family = AF_INET;
#ifndef _NO_SOCKADDR_LENGTH_
	dns->server[i].sin_len = sizeof(struct sockaddr_in);
#endif
	
	dns->server_count++;
}

void
dns_remove_server(dns_handle_t *dns, u_int32_t x)
{
	u_int32_t i;

	if (dns == NULL) return;
	if (x >= dns->server_count) return;

	if (dns->server_count == 1)
	{
		free(dns->server);
		dns->server = NULL;
		dns->server_count = 0;
		dns->selected_server = 0;
		return;
	}

	for (i = x + 1; i < dns->server_count; i++)
	{
		dns->server[i-1] = dns->server[i];
		if (dns->selected_server == i) dns->selected_server--;
	}

	dns->server_count--;
	dns->server = (struct sockaddr_in *)realloc((char *)dns->server,
		dns->server_count * sizeof(struct sockaddr_in));
}

/*
 * Release a DNS client handle
 */
void
dns_free(dns_handle_t *dns)
{
	u_int32_t i;

	if (dns == NULL) return;

	shutdown(dns->sock, 2);
	close(dns->sock);

	free(dns->server);
	free(dns->server_latency);
	free(dns->domain);
	for (i = 0; i < dns->search_count; i++) free(dns->search[i]);
	if (dns->search_count > 0) free(dns->search);
	if (dns->sort_count > 0)
	{
		free(dns->sort_addr);
		free(dns->sort_mask);
	}
	if (dns->log_title != NULL) free(dns->log_title);
	if (dns->log_file != NULL) fclose(dns->log_file);

	free(dns);
}

void
dns_set_xid(dns_handle_t *dns, u_int32_t x)
{
	if (dns == NULL) return;
	dns->xid = x;
}

void
dns_set_server_timeout(dns_handle_t *dns, struct timeval *tv)
{
	u_int32_t us;

	if (dns == NULL) return;

	us = (tv->tv_sec * 1000000) + tv->tv_usec;

	dns->server_timeout.tv_sec = us / 1000000;
	dns->server_timeout.tv_usec = us % 1000000;
	
	us = us * (dns->server_retries + 1) * dns->server_count;

	dns->timeout.tv_sec = us / 1000000;
	dns->timeout.tv_usec = us % 1000000;
}

void
dns_set_timeout(dns_handle_t *dns, struct timeval *tv)
{
	u_int32_t us;
	struct timeval m;

	if (dns == NULL) return;

	us = (tv->tv_sec * 1000000) + tv->tv_usec;

	dns->timeout.tv_sec = us / 1000000;
	dns->timeout.tv_usec = us % 1000000;

	us = us / ((dns->server_retries + 1) * dns->server_count);
	if (us == 0)
	{
		m.tv_sec = 0;
		m.tv_usec = 1000;
		dns_set_server_timeout(dns, &m);
		return;
	}

	dns->server_timeout.tv_sec = us / 1000000;
	dns->server_timeout.tv_usec = us % 1000000;
}

void
dns_set_server_retries(dns_handle_t *dns, u_int32_t n)
{
	u_int32_t us;

	if (dns == NULL) return;
	dns->server_retries = n;

	us = (dns->server_timeout.tv_sec * 1000000) + dns->server_timeout.tv_usec;
	
	us = us * (dns->server_retries + 1) * dns->server_count;

	dns->timeout.tv_sec = us / 1000000;
	dns->timeout.tv_usec = us % 1000000;
}

void
dns_set_protocol(dns_handle_t *dns, u_int32_t protocol)
{
	u_int32_t i, stype;
	u_int16_t port;

	if (dns == NULL) return;
	if (protocol == dns->protocol) return;

	if ((protocol != IPPROTO_UDP) && (protocol != IPPROTO_TCP))
	{
		dns_log_msg(dns, LOG_ERR, "dns_set_protocol - unknown protocol %u", protocol);
		return;
	}

	_dns_lock();

	dns->protocol = protocol;
	shutdown(dns->sock, 2);
	close(dns->sock);

	if (dns->protocol == IPPROTO_UDP)
	{
		stype = SOCK_DGRAM;
		dns->sockstate = DNS_SOCK_UDP;
	}
	else
	{
		stype = SOCK_STREAM;
		dns->sockstate = DNS_SOCK_TCP_UNCONNECTED;
	}

	dns->sock = socket(AF_INET, stype, dns->protocol);
	port = _dns_port(dns->protocol);
	for (i = 0; i < dns->server_count; i++) dns->server[i].sin_port = port;
	
	_dns_unlock();
}

void
dns_select_server(dns_handle_t *dns, u_int32_t which)
{
	u_int32_t stype;
	if (dns == NULL) return;

	if (which >= dns->server_count)
	{
		dns_log_msg(dns, LOG_ERR,
			"dns_select_server - only %u server%s, can't select server %u",
			dns->server_count, (dns->server_count == 1) ? "" : "s", which);
		return;
	}

	if (dns->selected_server == which) return;

	if (dns->sockstate == DNS_SOCK_TCP_CONNECTED)
	{
		_dns_lock();
		
		shutdown(dns->sock, 2);
		close(dns->sock);
		dns->sockstate = DNS_SOCK_TCP_UNCONNECTED;

		if (dns->protocol == IPPROTO_UDP) stype = SOCK_DGRAM;
		else stype = SOCK_STREAM;

		dns->sock = socket(AF_INET, stype, dns->protocol);

		_dns_unlock();
	}
	
	dns->selected_server = which;
}

static u_int8_t
_dns_parse_uint8(char **p)
{
	u_int8_t v;

	v = (u_int8_t)**p;
	*p += 1;
	return v;
}
	
static u_int16_t
_dns_parse_uint16(char **p)
{
	u_int16_t *x, v;

	x = (u_int16_t *)*p;
	v = ntohs(*x);
	*p += 2;
	return v;
}
	
static u_int32_t
_dns_parse_uint32(char **p)
{
	u_int32_t *x, v;

	x = (u_int32_t *)*p;
	v = ntohl(*x);
	*p += 4;
	return v;
}
	
static u_int8_t
_dns_cname_length(char *s)
{
	u_int8_t l;

	if (s == NULL) return 1;
	l = strlen(s);
	while ((s[l - 1] == '.') && (l > 1)) l--;
	return l;
}

static void
_dns_insert_cname(char *s, char *p)
{
	int i;
	u_int8_t len, dlen;

	if (s == NULL)
	{
		*p = 0;
		return;
	}

	if (!strcmp(s, "."))
	{
		p[0] = 1;
		p[1] = '.';
		p[2] = 0;
		return;
	}

	len = _dns_cname_length(s);
	
	p[0] = '.';
	memmove(p + 1, s, len);
	p[len + 1] = '.';

	dlen = 0;

	for (i = len + 1; i >= 0; i--)
	{
		if (p[i] == '.')
		{
			p[i] = dlen;
			dlen = 0;
		}
		else dlen++;
	}
}

static char *
_dns_parse_string(char *p, char **x)
{
	char *str;
	u_int8_t len;

	len = (u_int8_t)**x;
	*x += 1;
	str = malloc(len + 1);
	memmove(str, *x, len);
	str[len] = '\0';
	*x += len;
	return str;
}

static char *
_dns_parse_domain_name(char *p, char **x)
{
	u_int8_t *v8;
	u_int16_t *v16, skip;
	u_int16_t i, j, dlen, len;
	int more, compressed;
	char *name, *start;

	start = *x;
	compressed = 0;
	more = 1;
	name = malloc(1);
	name[0] = '\0';
	len = 1;
	j = 0;
	skip = 0;

	while (more == 1)
	{
		v8 = (u_int8_t *)*x;
		dlen = *v8;

		if ((dlen & 0xc0) == 0xc0)
		{
			v16 = (u_int16_t *)*x;
			*x = p + (ntohs(*v16) & 0x3fff);
			if (compressed == 0) skip += 2;
			compressed = 1;
			continue;
		}

		*x += 1;
		if (dlen > 0)
		{
			len += dlen;
			name = realloc(name, len);
		}
	
		for (i = 0; i < dlen; i++)
		{
			name[j++] = **x;
			*x += 1;
		}
		name[j] = '\0';
		if (compressed == 0) skip += (dlen + 1);
		
		if (dlen == 0) more = 0;
		else
		{
			v8 = (u_int8_t *)*x;
			if (*v8 != 0)
			{
				len += 1;
				name = realloc(name, len);
				name[j++] = '.';
				name[j] = '\0';
			}
		}
	}
	
	*x = start + skip;

	return name;
}

dns_resource_record_t *
dns_parse_resource_record(char *p, char **x)
{
	u_int32_t size, bx, mi;
	u_int16_t rdlen;
	u_int8_t byte, i;
	dns_resource_record_t *r;
	char *eor;

	r = (dns_resource_record_t *)malloc(sizeof(dns_resource_record_t));
	memset(r, 0, sizeof(dns_resource_record_t));

	r->name = _dns_parse_domain_name(p, x);
	r->type = _dns_parse_uint16(x);
	r->class = _dns_parse_uint16(x);
	r->ttl = _dns_parse_uint32(x);
	rdlen = _dns_parse_uint16(x);

	eor = *x;
	r->data.A = NULL;

	switch (r->type)
	{
		case DNS_TYPE_A:
			size = sizeof(dns_address_record_t);
			r->data.A = (dns_address_record_t *)malloc(size);
			r->data.A->addr.s_addr = htonl(_dns_parse_uint32(x));
			break;

		case DNS_TYPE_AAAA:
			size = sizeof(dns_in6_address_record_t);
			r->data.AAAA = (dns_in6_address_record_t *)malloc(size);
			r->data.AAAA->addr.__u6_addr.__u6_addr32[0] = htonl(_dns_parse_uint32(x));
			r->data.AAAA->addr.__u6_addr.__u6_addr32[1] = htonl(_dns_parse_uint32(x));
			r->data.AAAA->addr.__u6_addr.__u6_addr32[2] = htonl(_dns_parse_uint32(x));
			r->data.AAAA->addr.__u6_addr.__u6_addr32[3] = htonl(_dns_parse_uint32(x));
			break;

		case DNS_TYPE_NS:
		case DNS_TYPE_CNAME:
		case DNS_TYPE_MB:
		case DNS_TYPE_MG:
		case DNS_TYPE_MR:
		case DNS_TYPE_PTR:
			size = sizeof(dns_domain_name_record_t);
			r->data.CNAME = (dns_domain_name_record_t *)malloc(size);

			r->data.CNAME->name = _dns_parse_domain_name(p, x);
			break;
	
		case DNS_TYPE_SOA:
			size = sizeof(dns_SOA_record_t);
			r->data.SOA = (dns_SOA_record_t *)malloc(size);

			r->data.SOA->mname = _dns_parse_domain_name(p, x);
			r->data.SOA->rname = _dns_parse_domain_name(p, x);
			r->data.SOA->serial = _dns_parse_uint32(x);
			r->data.SOA->refresh = _dns_parse_uint32(x);
			r->data.SOA->retry = _dns_parse_uint32(x);
			r->data.SOA->expire = _dns_parse_uint32(x);
			r->data.SOA->minimum = _dns_parse_uint32(x);	
			break;

		case DNS_TYPE_NULL:
			size = sizeof(dns_raw_resource_record_t);
			r->data.DNSNULL = (dns_raw_resource_record_t *)malloc(size);

			r->data.DNSNULL->length = rdlen;
			r->data.DNSNULL->data = malloc(rdlen);
			memmove(r->data.DNSNULL->data, *x, rdlen);
			*x += rdlen;
			break;

		case DNS_TYPE_WKS:
			size = sizeof(dns_WKS_record_t);
			r->data.WKS = (dns_WKS_record_t *)malloc(size);

			r->data.WKS->addr.s_addr = htonl(_dns_parse_uint32(x));
			r->data.WKS->protocol = _dns_parse_uint8(x);
			size = rdlen - 5;
			r->data.WKS->maplength = size * 8;
			r->data.WKS->map = (u_int8_t *)malloc(r->data.WKS->maplength);
			mi = 0;
			for (bx = 0; bx < size; bx++)
			{
				byte = _dns_parse_uint8(x);
				for (i = 128; i >= 1; i = i/2)
				{
					if (byte & i) r->data.WKS->map[mi] = 0xff;
					else r->data.WKS->map[mi] = 0;
					mi++;
				}
			}
			break;

		case DNS_TYPE_HINFO:
			size = sizeof(dns_HINFO_record_t);
			r->data.HINFO = (dns_HINFO_record_t *)malloc(size);

			r->data.HINFO->cpu = _dns_parse_string(p, x);
			r->data.HINFO->os = _dns_parse_string(p, x);
			break;

		case DNS_TYPE_MINFO:
			size = sizeof(dns_MINFO_record_t);
			r->data.MINFO = (dns_MINFO_record_t *)malloc(size);

			r->data.MINFO->rmailbx = _dns_parse_domain_name(p, x);
			r->data.MINFO->emailbx = _dns_parse_domain_name(p, x);
			break;

		case DNS_TYPE_MX:
			size = sizeof(dns_MX_record_t);
			r->data.MX = (dns_MX_record_t *)malloc(size);

			r->data.MX->preference = _dns_parse_uint16(x);
			r->data.MX->name = _dns_parse_domain_name(p, x);
			break;

		case DNS_TYPE_TXT:
			size = sizeof(dns_TXT_record_t);
			r->data.TXT = (dns_TXT_record_t *)malloc(size);
			r->data.TXT->string_count = 0;
			r->data.TXT->strings = NULL;

			while (*x < (eor + rdlen))
			{
				if (r->data.TXT->string_count == 0)
				{
					r->data.TXT->strings = (char **)malloc(sizeof(char *));
				}
				else
				{
					r->data.TXT->strings = (char **)realloc(r->data.TXT->strings, (r->data.TXT->string_count + 1) * sizeof(char *));
				}

				r->data.TXT->strings[r->data.TXT->string_count++] = _dns_parse_string(p, x);
			}

			break;

		case DNS_TYPE_RP:
			size = sizeof(dns_RP_record_t);
			r->data.RP = (dns_RP_record_t *)malloc(size);

			r->data.RP->mailbox = _dns_parse_domain_name(p, x);
			r->data.RP->txtdname = _dns_parse_domain_name(p, x);
			break;

		case DNS_TYPE_AFSDB:
			size = sizeof(dns_AFSDB_record_t);
			r->data.AFSDB = (dns_AFSDB_record_t *)malloc(size);

			r->data.AFSDB->subtype = _dns_parse_uint32(x);
			r->data.AFSDB->hostname = _dns_parse_domain_name(p, x);
			break;

		case DNS_TYPE_X25:
			size = sizeof(dns_X25_record_t);
			r->data.X25 = (dns_X25_record_t *)malloc(size);

			r->data.X25->psdn_address = _dns_parse_string(p, x);
			break;

		case DNS_TYPE_ISDN:
			size = sizeof(dns_ISDN_record_t);
			r->data.ISDN = (dns_ISDN_record_t *)malloc(size);

			r->data.ISDN->isdn_address = _dns_parse_string(p, x);
			if (*x < (eor + rdlen))
				r->data.ISDN->subaddress = _dns_parse_string(p, x);
			else
				r->data.ISDN->subaddress = NULL;
			break;

		case DNS_TYPE_RT:
			size = sizeof(dns_RT_record_t);
			r->data.RT = (dns_RT_record_t *)malloc(size);

			r->data.RT->preference = _dns_parse_uint16(x);
			r->data.RT->intermediate = _dns_parse_domain_name(p, x);
			break;

		case DNS_TYPE_LOC:
			size = sizeof(dns_LOC_record_t);
			r->data.LOC = (dns_LOC_record_t *)malloc(size);

			r->data.LOC->version = _dns_parse_uint8(x);
			r->data.LOC->size = _dns_parse_uint8(x);
			r->data.LOC->horizontal_precision = _dns_parse_uint8(x);
			r->data.LOC->vertical_precision = _dns_parse_uint8(x);
			r->data.LOC->latitude = _dns_parse_uint32(x);
			r->data.LOC->longitude = _dns_parse_uint32(x);
			r->data.LOC->altitude = _dns_parse_uint32(x);
			break;

		case DNS_TYPE_SRV:
			size = sizeof(dns_SRV_record_t);
			r->data.SRV = (dns_SRV_record_t *)malloc(size);

			r->data.SRV->priority = _dns_parse_uint16(x);
			r->data.SRV->weight = _dns_parse_uint16(x);
			r->data.SRV->port = _dns_parse_uint16(x);
			r->data.SRV->target = _dns_parse_domain_name(p, x);
			break;
	}

	*x = eor + rdlen;	
	return r;
}

dns_question_t *
dns_parse_question(char *p, char **x)
{
	dns_question_t *q;
	
	if (x == NULL) return NULL;
	if (*x == NULL) return NULL;

	q = (dns_question_t *)malloc(sizeof(dns_question_t));

	q->name = _dns_parse_domain_name(p, x);
	q->type = _dns_parse_uint16(x);
	q->class = _dns_parse_uint16(x);

	return q;
}

u_int32_t
dns_dname_cmp(char *a, char *b)
{
	return strcasecmp(a, b);
}

/* Return 1 if input is name.domain */
u_int32_t
dns_domain_match(char *name, char *domain)
{
	u_int32_t dl, nl, l;

	if (name == NULL) return 0;
	if (domain == NULL) return 1;

	nl = strlen(name);
	while (name[nl-1] == '.') nl--;
	dl = strlen(domain);
	if (dl > nl) return 0;

	l = nl - dl;

	if ((l != 0) && (name[l - 1] != '.')) return 0;
	if (strncasecmp(name + l, domain, dl)) return 0;

	return 1;
}

dns_reply_t *
dns_parse_packet(char *p)
{
	dns_reply_t *r;
	dns_header_t *h;
	char *x;
	u_int32_t i, size;
	
	if (p == NULL) return NULL;
	x = p;

	r = (dns_reply_t *)malloc(sizeof(dns_reply_t));
	memset(r, 0, sizeof(dns_reply_t));

	r->header = (dns_header_t *)malloc(sizeof(dns_header_t));	
	h = r->header;
	memset(h, 0, sizeof(dns_header_t));

	h->xid = _dns_parse_uint16(&x);
	h->flags = _dns_parse_uint16(&x);
	h->qdcount = _dns_parse_uint16(&x);
	h->ancount = _dns_parse_uint16(&x);
	h->nscount = _dns_parse_uint16(&x);
	h->arcount = _dns_parse_uint16(&x);
		
	size = sizeof(dns_question_t *);
	r->question = (dns_question_t **)malloc(h->qdcount * size);
	for (i = 0; i < h->qdcount; i++)
		r->question[i] = dns_parse_question(p, &x);
	
	size = sizeof(dns_resource_record_t *);
	
	r->answer = (dns_resource_record_t **)malloc(h->ancount * size);
	for (i = 0; i < h->ancount; i++)
		r->answer[i] = dns_parse_resource_record(p, &x);
		
	r->authority = (dns_resource_record_t **)malloc(h->nscount * size);
	for (i = 0; i < h->nscount; i++)
		r->authority[i] = dns_parse_resource_record(p, &x);
	
	r->additional = (dns_resource_record_t **)malloc(h->arcount * size);
	for (i = 0; i < h->arcount; i++)
		r->additional[i] = dns_parse_resource_record(p, &x);
		
	return r;
}

void
dns_apply_sortlist(dns_handle_t *dns, dns_reply_t *r)
{
	u_int32_t i, j, len, swap;
	u_int32_t *o, *x, a, m, n, t;
	dns_resource_record_t *tr;

	if (dns == NULL) return;
	if (r == NULL) return;
	if (dns->sort_count == 0) return;
	if (r->header == NULL) return;
	len = r->header->ancount;
	if (len == 0) return;

	/* Find each DNS_TYPE_A record */
	/* Keep its index (variable x) */
	/* Assign it an "order" (variable o) based on which sortlist entry it matches */

	o = NULL;
	x = NULL;

	n = 0;
	for (i = 0; i < len; i++)
	{
		if (r->answer[i]->type == DNS_TYPE_A)
		{
			a = r->answer[i]->data.A->addr.s_addr;
			
			if (n == 0)
			{
				o = (u_int32_t *)malloc(sizeof(u_int32_t));
				x = (u_int32_t *)malloc(sizeof(u_int32_t));
			}
			else
			{
				o = (u_int32_t *)realloc((char *)o, (n + 1) * sizeof(u_int32_t));
				x = (u_int32_t *)realloc((char *)x, (n + 1) * sizeof(u_int32_t));
			}

			o[n] = dns->sort_count;
			x[n] = i;

			for (j = 0; j < dns->sort_count; j++)
			{
				m = dns->sort_mask[j];
				if ((a & m) == (dns->sort_addr[j] & m))
				{
					o[n] = j;
					break;
				}
			}

			n++;
		}
	}

	if (n == 0) return;

	/* Bubble sort the DNS_TYPE_A records by their "order" */
	swap = 1;
	len = n - 1;

	while (swap == 1)
	{
		swap = 0;
		for (i = 0; i < len; i++)
		{
			j = i + 1;
			if (o[i] > o[j])
			{
				swap = 1;
				t = o[i];
				o[i] = o[j];
				o[j] = t;

				tr = r->answer[x[i]];
				r->answer[x[i]] = r->answer[x[j]];
				r->answer[x[j]] = tr;
			}
		}
		len--;
	}

	free(o);
	free(x);
}

void
dns_free_resource_record(dns_resource_record_t *r)
{
	int i;

	free(r->name);

	switch (r->type)
	{
		case DNS_TYPE_A:
			free(r->data.A);
			break;

		case DNS_TYPE_AAAA:
			free(r->data.AAAA);
			break;

		case DNS_TYPE_NS:
		case DNS_TYPE_CNAME:
		case DNS_TYPE_MB:
		case DNS_TYPE_MG:
		case DNS_TYPE_MR:
		case DNS_TYPE_PTR:
			free(r->data.CNAME->name);
			free(r->data.CNAME);
			break;
	
		case DNS_TYPE_SOA:
			free(r->data.SOA->mname);
			free(r->data.SOA->rname);
			free(r->data.SOA);	
			break;

		case DNS_TYPE_NULL:
			free(r->data.DNSNULL->data);
			free(r->data.DNSNULL);
			break;

		case DNS_TYPE_WKS:
			free(r->data.WKS->map);
			free(r->data.WKS);
			break;

		case DNS_TYPE_HINFO:
			free(r->data.HINFO->cpu);
			free(r->data.HINFO->os);
			free(r->data.HINFO);	
			break;

		case DNS_TYPE_MINFO:
			free(r->data.MINFO->rmailbx);
			free(r->data.MINFO->emailbx);
			free(r->data.MINFO);	
			break;

		case DNS_TYPE_MX:
			free(r->data.MX->name);
			free(r->data.MX);
			break;

		case DNS_TYPE_TXT:
			for (i=0; i<r->data.TXT->string_count; i++)
			{
				free(r->data.TXT->strings[i]);
			}
			if (r->data.TXT->strings != NULL)
				free(r->data.TXT->strings);
			free(r->data.TXT);
			break;

		case DNS_TYPE_RP:
			free(r->data.RP->mailbox);
			free(r->data.RP->txtdname);
			free(r->data.RP);
			break;

		case DNS_TYPE_AFSDB:
			free(r->data.AFSDB->hostname);
			free(r->data.AFSDB);
			break;

		case DNS_TYPE_X25:
			free(r->data.X25->psdn_address);
			free(r->data.X25);
			break;

		case DNS_TYPE_ISDN:
			free(r->data.ISDN->isdn_address);
			if (r->data.ISDN->subaddress != NULL)
				free(r->data.ISDN->subaddress);
			free(r->data.ISDN);
			break;

		case DNS_TYPE_RT:
			free(r->data.RT->intermediate);
			free(r->data.RT);
			break;

		case DNS_TYPE_LOC:
			free(r->data.LOC);
			break;

		case DNS_TYPE_SRV:
			free(r->data.SRV->target);
			free(r->data.SRV);
			break;
	}

	free(r);
}

void
dns_free_reply(dns_reply_t *r)
{
	u_int32_t i;

	if (r == NULL) return;
	if (r->header != NULL)
	{
		for (i = 0; i < r->header->qdcount; i++)
		{
			free(r->question[i]->name);
			free(r->question[i]);
		}

		for (i = 0; i < r->header->ancount; i++) dns_free_resource_record(r->answer[i]);
		for (i = 0; i < r->header->nscount; i++) dns_free_resource_record(r->authority[i]);
		for (i = 0; i < r->header->arcount; i++) dns_free_resource_record(r->additional[i]);

		free(r->header);
	}

	if (r->question != NULL) free(r->question);
	if (r->answer != NULL) free(r->answer);
	if (r->authority != NULL) free(r->authority);
	if (r->additional != NULL) free(r->additional);

	free(r);
}

void
dns_free_reply_list(dns_reply_list_t *l)
{
	u_int32_t i;

	if (l == NULL) return;

	for (i = 0; i < l->count; i++) dns_free_reply(l->reply[i]);
	free(l);
}

static u_int16_t
dns_random_xid(dns_handle_t *dns, char *packet)
{
	dns_header_t *h;
	char *q;
	u_int16_t x;

	q = packet;
	if (dns->protocol == IPPROTO_TCP) q += 2;

	h = (dns_header_t *)q;

	x = dns_random() % 0x10000;
	if (x == dns->xid) x++;
	if (x == 0) x++;

	h->xid = htons(x);
	dns->xid = x;

	return x;
}

char *
dns_build_query_packet(dns_handle_t *dns, dns_question_t *dnsq, u_int16_t *ql, u_int16_t *xid)
{
	u_int16_t *p, len, x, flags;
	char *q, *s;
	dns_header_t *h;

	if (dnsq == NULL)
	{
		dns_log_msg(dns, LOG_WARNING, "dns_build_query_packet - NULL query");
		return NULL;
	}

	if (dnsq->name == NULL)
	{
		dns_log_msg(dns, LOG_WARNING, "dns_build_query_packet - NULL name in query");
		return NULL;
	}

	len = DNS_HEADER_SIZE + _dns_cname_length(dnsq->name) + 6;
	if (dns->protocol == IPPROTO_TCP) len += 2;
	*ql = len;

	s = malloc(len);
	memset(s, 0, len);

	q = s;
	if (dns->protocol == IPPROTO_TCP) 
	{
		x = htons(len - 2);
		memmove(s, &x, sizeof(u_int16_t));
		q = s + 2;
	}

	h = (dns_header_t *)q;

	*xid = dns_random_xid(dns, s);

	flags = DNS_FLAGS_RD;
	h->flags = htons(flags);
	h->qdcount = htons(1);

	_dns_insert_cname(dnsq->name, (char *)h + DNS_HEADER_SIZE);
	p = (u_int16_t *)(s + (len - 4));
	*p = htons(dnsq->type);
	p = (u_int16_t *)(s + (len - 2));
	*p = htons(dnsq->class);

	return s;
}

int32_t
dns_read_reply(dns_handle_t *dns, dns_query_data_t *q, u_int32_t qn, u_int32_t *whichreply, char *qname, char **r, u_int16_t *rlen)
{
	ssize_t rsize;
	u_int16_t len;
	u_int32_t flen;
	u_int16_t *prxid, rxid;
	u_int32_t i;
	struct sockaddr_in from;
	int status;

	if (dns->protocol == IPPROTO_UDP)
	{
		*rlen = REPLY_BUF_SIZE;
	}
	else
	{
		/* TCP: first 4 bytes is the reply length */
		flen = sizeof(struct sockaddr_in);
		rsize = recvfrom(dns->sock, &len, 2, 0, (struct sockaddr *)&from, &flen);
		if (rsize <= 0)
		{
			dns_log_msg(dns, LOG_ERR, "dns_read_reply - size receive failed");
			return DNS_STATUS_RECEIVE_FAILED;
		}

		*rlen = ntohs(len);
		status = setsockopt(dns->sock, SOL_SOCKET, SO_RCVLOWAT, rlen, 4);
		if (status < 0) dns_log_msg(dns, LOG_ERR, "dns_read_reply - setsockopt status %d errno=%d", status, errno);
	}

	*r = malloc(*rlen);
	memset(*r, 0, *rlen);

	flen = sizeof(struct sockaddr_in);

	rsize = recvfrom(dns->sock, *r, *rlen, 0, (struct sockaddr *)&from, &flen);
	if (rsize <= 0)
	{
		free(*r);
		dns_log_msg(dns, LOG_ERR, "dns_read_reply - receive failed");
		return DNS_STATUS_RECEIVE_FAILED;
	}

	if ((dns->protocol == IPPROTO_TCP) && (*rlen != rsize))
	{
		free(*r);
		dns_log_msg(dns, LOG_ERR, "dns_read_reply - short reply %d %d\n", *rlen, rsize);
		return DNS_STATUS_RECEIVE_FAILED;
	}

#ifdef CHECK_REPLY_SERVER
	if (dns->protocol == IPPROTO_UDP)
	{
		if ((from.sin_family != dns->server[which].sin_family) ||
		(from.sin_port != dns->server[which].sin_port) ||
		(from.sin_addr.s_addr != dns->server[which].sin_addr.s_addr))
		{
			free(*r);
			dns_log_msg(dns, LOG_INFO,
				"dns_read_reply - reply from wrong server (%s)",
				inet_ntoa(from.sin_addr));
			return DNS_STATUS_WRONG_SERVER;
		}
	}
#endif

	/* Check reply xid */
	prxid = (u_int16_t *)*r;
	rxid = ntohs(*prxid);

	/* See if this is the reply for an outstanding query */
	for (i = 0; i <= qn; i++)
	{
		if (rxid == q[i].xid) break;
	}

	if (i > qn)
	{
		free(*r);
		dns_log_msg(dns, LOG_INFO, "dns_read_reply - no reply for XID %hu", rxid);
		return DNS_STATUS_WRONG_XID;
	}

	/* Check for wrong question in reply */
	if ((qname != NULL) && (dns_dname_cmp((*r) + DNS_HEADER_SIZE, qname)))
	{
		free(*r);
		dns_log_msg(dns, LOG_INFO, "dns_read_reply - bad query");
		return DNS_STATUS_WRONG_QUESTION;
	}

	/* Timestamp the reply for latency measurement */
	gettimeofday(&(q[i].reply_time), NULL);
	if (whichreply != NULL) *whichreply = i;

	return DNS_STATUS_OK;
}

static void
_dns_append_question(dns_question_t *q, char **s, u_int16_t *l)
{
	u_int16_t len, *p;
	char *x;

	if (q == NULL) return;

	len = *l + _dns_cname_length(q->name) + 2 + 4;
	*s = realloc(*s, len);

	_dns_insert_cname(q->name, (char *)*s + *l);
	*l = len;

	x = *s + (len - 4);

	p = (u_int16_t *)x;
	*p = htons(q->type);
	x += 2;

	p = (u_int16_t *)x;
	*p = htons(q->class);

}

static void
_dns_append_resource_record(dns_resource_record_t *r, char **s, u_int16_t *l)
{
	u_int16_t clen, len, *p, extra, rdlen;
	u_int32_t *p2;
	char *x;

	if (r == NULL) return;

	extra = 10;
	switch (r->type)
	{
		case DNS_TYPE_A:
			extra += 4;
			break;
		case DNS_TYPE_PTR:
			extra += 2;
			clen = _dns_cname_length(r->data.PTR->name);
			extra += clen;
			break;
		default: break;
	}

	len = *l + _dns_cname_length(r->name) + 2 + extra;
	*s = realloc(*s, len);

	_dns_insert_cname(r->name, (char *)*s + *l);
	*l = len;

	x = *s + (len - extra);

	p = (u_int16_t *)x;
	*p = htons(r->type);
	x += 2;

	p = (u_int16_t *)x;
	*p = htons(r->class);
	x += 2;

	p2 = (u_int32_t *)x;
	*p2 = htonl(r->ttl);
	x += 4;

	switch (r->type)
	{
		case DNS_TYPE_A:
			rdlen = 4;
			p = (u_int16_t *)x;
			*p = htons(rdlen);
			x += 2;

			p2 = (u_int32_t *)x;
			*p2 = htons(r->data.A->addr.s_addr);
			x += 4;
			return;

		case DNS_TYPE_PTR:
			clen = _dns_cname_length(r->data.PTR->name) + 2;
			p = (u_int16_t *)x;
			*p = htons(clen);
			x += 2;
			_dns_insert_cname(r->data.PTR->name, x);
			x += clen;
			return;
		
		default: return;
	}
}

char *
dns_build_reply(dns_reply_t *dnsr, u_int16_t *rl)
{
	u_int16_t i, len;
	dns_header_t *h;
	char *s, *x;

	if (dnsr == NULL) return NULL;

	len = DNS_HEADER_SIZE;

	s = malloc(len);
	x = s + len;

	memset(s, 0, len);
	*rl = len;

	h = (dns_header_t *)s;

	h->xid = htons(dnsr->header->xid);
	h->flags = htons(dnsr->header->flags);
	h->qdcount = htons(dnsr->header->qdcount);
	h->ancount = htons(dnsr->header->ancount);
	h->nscount = htons(dnsr->header->nscount);
	h->arcount = htons(dnsr->header->arcount);

	for (i = 0; i < dnsr->header->qdcount; i++)
	{
		_dns_append_question(dnsr->question[i], &s, rl);
	}

	for (i = 0; i < dnsr->header->ancount; i++)
	{
		_dns_append_resource_record(dnsr->answer[i], &s, rl);
	}

	for (i = 0; i < dnsr->header->nscount; i++)
	{
		_dns_append_resource_record(dnsr->authority[i], &s, rl);
	}

	for (i = 0; i < dnsr->header->arcount; i++)
	{
		_dns_append_resource_record(dnsr->additional[i], &s, rl);
	}

	return s;
}

int32_t
dns_read_query(dns_handle_t *dns, char **q, u_int16_t *qlen)
{
	ssize_t rsize;
	u_int16_t len;
	u_int32_t flen;
	struct sockaddr_in from;
	int status;

	if (dns->protocol == IPPROTO_UDP)
	{
		*qlen = REPLY_BUF_SIZE;
	}
	else
	{
		/* TCP: first 4 bytes is the query length */
		flen = sizeof(struct sockaddr_in);
		rsize = recvfrom(dns->sock, &len, 2, 0, (struct sockaddr *)&from, &flen);
		if (rsize <= 0)
		{
			dns_log_msg(dns, LOG_ERR, "dns_read_query - size receive failed");
			return DNS_STATUS_RECEIVE_FAILED;
		}

		*qlen = ntohs(len);
		status = setsockopt(dns->sock, SOL_SOCKET, SO_RCVLOWAT, qlen, 4);
		if (status < 0) dns_log_msg(dns, LOG_ERR, "dns_read_query - setsockopt status %d errno=%d", status, errno);
	}

	*q = malloc(*qlen);
	memset(*q, 0, *qlen);

	flen = sizeof(struct sockaddr_in);

	rsize = recvfrom(dns->sock, *q, *qlen, 0, (struct sockaddr *)&from, &flen);
	if (rsize <= 0)
	{
		free(*q);
		dns_log_msg(dns, LOG_ERR, "dns_read_query - receive failed");
		return DNS_STATUS_RECEIVE_FAILED;
	}

	if ((dns->protocol == IPPROTO_TCP) && (*qlen != rsize))
	{
		free(*q);
		dns_log_msg(dns, LOG_ERR, "dns_read_query - short reply %d %d\n", *qlen, rsize);
		return DNS_STATUS_RECEIVE_FAILED;
	}

	return DNS_STATUS_OK;
}

/* Only used by zone transfer */
int32_t
dns_send_query(dns_handle_t *dns, dns_query_data_t *q)
{
	ssize_t i;
	int32_t status;
	u_int32_t slen;
	struct sockaddr *dst;

	if (dns == NULL) return DNS_STATUS_BAD_HANDLE;
	if (q == NULL) return DNS_STATUS_MALFORMED_QUERY;

	if (q->server_index >= dns->server_count)
	{
		dns_log_msg(dns, LOG_ERR, "dns_send_query - invalid server selection");
		return DNS_STATUS_BAD_HANDLE;
	}

	slen = sizeof(struct sockaddr_in);
	dst = (struct sockaddr *)&(dns->server[q->server_index]);

	dns_select_server(dns, q->server_index);

	if (dns->sockstate == DNS_SOCK_TCP_UNCONNECTED)
	{
		/* connect to server */
		status = connect(dns->sock, dst, sizeof(struct sockaddr_in));
		if (status < 0)
		{
			dns_log_msg(dns, LOG_ERR, "dns_send_query - TCP connect failed");
			return DNS_STATUS_CONNECTION_FAILED;
		}
		dns->sockstate = DNS_SOCK_TCP_CONNECTED;
	}

	/* Timestamp the query for latency measurement */
	gettimeofday(&(q->send_time), NULL);

	i = sendto(dns->sock, q->query_packet, q->query_length, 0, dst, slen);
	if (i < 0)
	{
		dns_log_msg(dns, LOG_ERR, "dns_send_query - send failed (%s)", strerror(errno));
		return DNS_STATUS_SEND_FAILED;
	}

	return DNS_STATUS_OK;
}

int32_t
dns_zone_transfer_query(dns_handle_t *dns, u_int16_t class, dns_query_data_t *q)
{
	dns_question_t ztq;
	int32_t i, j, status, *si, silen;
	char *qp;
	u_int16_t qlen;

	if (dns == NULL) return DNS_STATUS_BAD_HANDLE;

	ztq.type = DNS_TYPE_AXFR;
	ztq.class = class;
	ztq.name = dns->domain;
	
	qp = dns_build_query_packet(dns, &ztq, &qlen, &(q->xid));
	if (qp == NULL)
	{
		dns_log_msg(dns, LOG_ERR, "dns_zone_transfer_query - malformed query");
		return DNS_STATUS_MALFORMED_QUERY;
	}

	q->query_packet = qp;
	q->query_length = qlen;

	silen = dns->server_count;
	si = (u_int32_t *)malloc(silen * sizeof(u_int32_t));
	for (j = 0, i = dns->selected_server; i < dns->server_count; i++, j++)
		si[j] = i;
	for (i = 0; i < dns->selected_server; i++, j++)
		si[j] = i;

	for (i = 0; i < silen; i++)
	{
		q->server_index = si[i];
	
		status = dns_send_query(dns, q);
		if (status == DNS_STATUS_OK)
		{
			free(qp);
			free(si);
			return status;
		}
	}

	dns_select_server(dns, si[0]);

	free(qp);
	free(si);
	dns_log_msg(dns, LOG_ERR, "dns_zone_transfer_query - send failed");
	return DNS_STATUS_SEND_FAILED;
}

dns_reply_list_t *
dns_zone_transfer(dns_handle_t *dns, u_int16_t class)
{
	char *rp;
	u_int32_t status, which;
	u_int16_t rplen;
	int proto;
	dns_reply_t *r;
	dns_reply_list_t *rlist;
	dns_query_data_t q;

	if (dns == NULL) return NULL;

	proto = dns->protocol;
	dns_set_protocol(dns, IPPROTO_TCP);
	status = dns_zone_transfer_query(dns, class, &q);
	if (status != DNS_STATUS_OK)
	{
		dns_log_msg(dns, LOG_ERR, "dns_zone_transfer - query failed");
		dns_set_protocol(dns, proto);
		return NULL;
	}

	rlist = (dns_reply_list_t *)malloc(sizeof(dns_reply_list_t));
	rlist->count = 0;
	rlist->reply = NULL;

	status = dns_read_reply(dns, &q, 0, &which, NULL, &rp, &rplen);

	while (status == DNS_STATUS_OK)
	{
		r = dns_parse_packet(rp);
		free(rp);

		r->status = status;
		r->server.s_addr = dns->server[which].sin_addr.s_addr;

		if (rlist->count == 0)
		{
			rlist->reply = (dns_reply_t **)malloc(sizeof(dns_reply_t *));
		}
		else
		{
			rlist->reply = (dns_reply_t **)realloc(rlist->reply, (rlist->count + 1) * sizeof(dns_reply_t *));
		}

		rlist->reply[rlist->count] = r;
		rlist->count++;

		if ((rlist->count > 1) && (r->header->ancount > 0) && (r->answer[0]->type == DNS_TYPE_SOA))
		{
			break;
		}

		status = dns_read_reply(dns, &q, 0, &which, NULL, &rp, &rplen);
	}

	dns_set_protocol(dns, proto);
	return rlist;
}

static int32_t
dns_send_query_server(dns_handle_t *dns, dns_query_data_t *q, u_int32_t qn, char **r, u_int16_t *rlen, struct timeval *tout)
{
	ssize_t i;
	int32_t status, ss, which, whichreply;
	u_int32_t slen;
	struct sockaddr *dst;
	struct sockaddr_in *sin;
	in_addr_t dstaddr;
	fd_set readfds;
	int maxfd;
	char *qname;
	struct timeval dt;
	struct ifaddrs *ifa, *p;

	if (dns == NULL) return DNS_STATUS_BAD_HANDLE;

	if (q == NULL)
	{
		dns_log_msg(dns, LOG_ERR, "dns_send_query_server - malformed query");
		return DNS_STATUS_MALFORMED_QUERY;
	}

	if (q[qn].query_length == 0)
	{
		dns_log_msg(dns, LOG_ERR, "dns_send_query_server - malformed query");
		return DNS_STATUS_MALFORMED_QUERY;
	}

	slen = sizeof(struct sockaddr_in);
	maxfd = dns->sock + 1;
	which = q[qn].server_index;
	dst = (struct sockaddr *)&(dns->server[which]);
	dstaddr = dns->server[which].sin_addr.s_addr;

	dns_select_server(dns, which);
	qname = q[qn].query_packet + DNS_HEADER_SIZE;
	if (dns->protocol == IPPROTO_TCP) qname += 2;

	if (dns->sockstate == DNS_SOCK_TCP_UNCONNECTED)
	{
		/* connect to server */
		status = connect(dns->sock, dst, sizeof(struct sockaddr_in));
		if (status < 0)
		{
			dns_log_msg(dns, LOG_ERR, "dns_send_query_server - TCP connect failed");
			return DNS_STATUS_CONNECTION_FAILED;
		}

		dns->sockstate = DNS_SOCK_TCP_CONNECTED;
	}

	status = DNS_STATUS_TIMEOUT;

#ifdef DEBUG_QUERY
	dns_log_msg(dns, LOG_DEBUG,
		"dns_send_query_server - XID %hu server %s (latency %u timeout %u+%u)",
		q[qn].xid, inet_ntoa(dns->server[which].sin_addr), dns->server_latency[which], 
		tout->tv_sec, tout->tv_usec);
#endif

	gettimeofday(&(q[qn].send_time), NULL);

	/* Send the query */
	if (IN_MULTICAST(ntohl(dstaddr)))
	{
		/* XXX Could improve performance by cacheing the interfaces XXX */
		if (getifaddrs(&ifa) < 0)
		{
				dns_log_msg(dns, LOG_ERR, "dns_send_query_server - getifaddrs failed (%s)", strerror(errno));
				return DNS_STATUS_SEND_FAILED;
		}

		for (p = ifa; p != NULL; p = p->ifa_next)
		{
			if (p->ifa_addr == NULL) continue;
			if ((p->ifa_flags & IFF_UP) == 0) continue;
			if (p->ifa_addr->sa_family != AF_INET) continue;
			if ((p->ifa_flags & IFF_MULTICAST) == 0) continue;
			if ((p->ifa_flags & IFF_POINTOPOINT) != 0)
			{
				if (dstaddr <= htonl(INADDR_MAX_LOCAL_GROUP)) continue;
			}

			sin = (struct sockaddr_in *)p->ifa_addr;
			i = setsockopt(dns->sock, IPPROTO_IP, IP_MULTICAST_IF, &sin->sin_addr, sizeof(sin->sin_addr));
			if (i < 0)
			{
				dns_log_msg(dns, LOG_ERR, "dns_send_query - setsockopt failed for interface %s (%s)", p->ifa_name, strerror(errno));
				return DNS_STATUS_SEND_FAILED;
			}

			i = sendto(dns->sock, q[qn].query_packet, q[qn].query_length, 0, dst, slen);
			if (i < 0)
			{
				dns_log_msg(dns, LOG_ERR, "dns_send_query_server - multicast send failed on interface %s for %s", p->ifa_name, inet_ntoa(dns->server[which].sin_addr));
				return DNS_STATUS_SEND_FAILED;
			}
		}

		freeifaddrs(ifa);   
	}
	else
	{
		i = sendto(dns->sock, q[qn].query_packet, q[qn].query_length, 0, dst, slen);
		if (i < 0)
		{
			dns_log_msg(dns, LOG_ERR, "dns_send_query_server - send failed for %s", inet_ntoa(dns->server[which].sin_addr));
			return DNS_STATUS_SEND_FAILED;
		}
	}	

	FD_ZERO(&readfds);
	FD_SET(dns->sock, &readfds);

	ss = select(maxfd, &readfds, NULL, NULL, tout);
	if (ss < 0)
	{
		dns_log_msg(dns, LOG_ERR, "dns_send_query_server - select failed");
		return DNS_STATUS_SEND_FAILED;
	}

	if (ss == 0)
	{
		dns_log_msg(dns, LOG_INFO,
			"dns_send_query_server - timeout for %s",
			inet_ntoa(dns->server[which].sin_addr));
		return DNS_STATUS_TIMEOUT;
	}
	
	if (! FD_ISSET(dns->sock, &readfds))
	{
		dns_log_msg(dns, LOG_INFO,
			"dns_send_query_server - bad reply for %s",
			inet_ntoa(dns->server[which].sin_addr));
		return DNS_STATUS_SEND_FAILED;
	}
	
	status = dns_read_reply(dns, q, qn, &whichreply, qname, r, rlen);

	/* If the reply wasn't what we were expecting, check for more replies */
	while ((status == DNS_STATUS_WRONG_XID) || (status == DNS_STATUS_WRONG_QUESTION))
	{
		/* 1/4 second to check for more data */
		dt.tv_sec = 0;
		dt.tv_usec = 250000;

		ss = select(maxfd, &readfds, NULL, NULL, &dt);
		if (ss > 0) status = dns_read_reply(dns, q, qn, &whichreply, qname, r, rlen);
 		else status = DNS_STATUS_TIMEOUT;
	}

	if (status == DNS_STATUS_OK)
	{
		i = q[whichreply].server_index;

		/* Latency for this reply */
		_time_subtract(&(q[whichreply].reply_time), q[whichreply].send_time.tv_sec, q[whichreply].send_time.tv_usec);
		*tout = q[whichreply].reply_time;

		/* Update latency measure for this server */
		q[whichreply].reply_time.tv_usec += (q[whichreply].reply_time.tv_sec * 1000000);
		if (dns->server_latency[i] == 0) dns->server_latency[i] = q[whichreply].reply_time.tv_usec;
		dns->server_latency[i] = ((dns->server_latency[i] / 100) * (100 - dns->latency_adjust)) + ((q[whichreply].reply_time.tv_usec / 100) * dns->latency_adjust);

#ifdef DEBUG_QUERY
		dns_log_msg(dns, LOG_DEBUG, "dns_send_query_server - reply time %u from %s", q[whichreply].reply_time.tv_usec, inet_ntoa(dns->server[i].sin_addr));
#endif
	}

#ifdef DEBUG_QUERY
	dns_log_msg(dns, LOG_DEBUG, "dns_send_query_server - reply status %u", status);
#endif
	return status;
}

dns_reply_t *
dns_fqdn_query_server(dns_handle_t *dns, u_int32_t which, dns_question_t *dnsq)
{
	dns_reply_t *r;
	char *qp, *rp;
	int32_t i, j, status, nqueries, tr, ts, tl, rcode;
	u_int16_t rplen, qplen;
	struct timeval time_remaining, dt;
	dns_query_data_t *q;

	if (dns == NULL) return NULL;
	if (dnsq == NULL) return NULL;

	if ((which != (u_int32_t)-1) && (which >= dns->server_count))
	{
		dns_log_msg(dns, LOG_ERR, "dns_fqdn_query_server - invalid server selection");
		return NULL;
	}

	/* .LOCAL USED HERE */

	/*
	 * Exclude local multicast queries
	 * if this is not a local multicast client
	 */
	if (strcasecmp(dns->domain, LOCAL_DOMAIN_STRING))
	{
		if (dns_domain_match(dnsq->name, LOCAL_DOMAIN_STRING)) return NULL;
	}

	status = DNS_STATUS_SEND_FAILED;

	nqueries = dns->server_retries;
	if (which == (u_int32_t)-1) nqueries = dns->server_count * dns->server_retries;

#ifdef DEBUG_QUERY
	dns_log_msg(dns, LOG_DEBUG, "dns_fqdn_query_server name:%s type:%hu class:%hu", dnsq->name, dnsq->type, dnsq->class);
#endif

	q = (dns_query_data_t *)malloc(nqueries * sizeof(dns_query_data_t));

	qp = dns_build_query_packet(dns, dnsq, &qplen, &(q[0].xid));
	if (qp == NULL)
	{
		dns_log_msg(dns, LOG_ERR, "dns_fqdn_query_server - malformed query");
		free(q);
		return NULL;
	}

	if (which == (u_int32_t)-1)
	{
		j = dns->selected_server;
		for (i = 0; i < nqueries; i++)
		{
			q[i].server_index = j;
			j++;
			if (j >= dns->server_count) j = 0;
			q[i].query_packet = qp;
			q[i].query_length = qplen;
		}
	}
	else
	{
		j = dns->selected_server;
		for (i = 0; i < nqueries; i++)
		{
			q[i].server_index = j;
			q[i].query_packet = qp;
			q[i].query_length = qplen;
		}
	}

	status = DNS_STATUS_TIMEOUT;

	ts = (dns->server_timeout.tv_sec * 1000000) + dns->server_timeout.tv_usec;
	time_remaining = dns->timeout;

	if ((ts == 0) && (dns->timeout.tv_sec == 0) && (dns->timeout.tv_usec == 0))
	{
		time_remaining.tv_sec = DNS_SERVER_TIMEOUT * (DNS_SERVER_RETRIES + 1);
	}

	for (i = 0; (i < nqueries) && (status != DNS_STATUS_OK); i++)
	{
		q[i].xid = dns_random_xid(dns, qp);

		rplen = REPLY_BUF_SIZE;

		/* Timeout (seconds) is 2 * expected latency for this server */
		dt.tv_sec = dns->server_latency[q[i].server_index] / 500000;
		dt.tv_usec = 0;

		/* If we haven't determined a latency yet, use default server timeout */
		if ((dt.tv_sec == 0) && (dt.tv_usec == 0)) dt.tv_sec = DNS_SERVER_TIMEOUT;

		tl = (dt.tv_sec * 1000000) + dt.tv_usec;

		tr = (time_remaining.tv_sec * 1000000) + time_remaining.tv_usec;

		/*
		 * If per-server timeout is set (non-zero)
		 * and is less than latency, use per-server timeout
		 */
		if ((ts > 0) && (ts < tl))
		{
			dt.tv_sec = dns->server_timeout.tv_sec;
			dt.tv_usec = dns->server_timeout.tv_usec;
			tl = (dt.tv_sec * 1000000) + dt.tv_usec;
		}

		/*
		 * If time remaining for this query is less than timeout
		 * use time_remaining as timeout.
		 */
		if ((tr > 0) && (tr < tl))
		{
			dt.tv_sec = time_remaining.tv_sec;
			dt.tv_usec = time_remaining.tv_usec;
			tl = (dt.tv_sec * 1000000) + dt.tv_usec;
		}
	
		if (tl == 0)
		{
			/* No time left */
			status = DNS_STATUS_TIMEOUT;
			break;
		}

		status = dns_send_query_server(dns, q, i, &rp, &rplen, &dt);

		if (status == DNS_STATUS_OK)
		{
			r = dns_parse_packet(rp);
			if (r->header->flags & DNS_FLAGS_TC)
			{
				/* Switch to TCP and try again */
				free(rp);
				dns_free_reply(r);
				
				dns_set_protocol(dns, IPPROTO_TCP);
				free(qp);
				qp = dns_build_query_packet(dns, dnsq, &qplen, &(q[i].xid));
				if (qp == NULL)
				{
					free(q);
					return NULL;
				}
				rplen = REPLY_BUF_SIZE;
				status = dns_send_query_server(dns, q, i, &rp, &rplen, &dt);

				/* Switch back to UDP */
				dns_set_protocol(dns, IPPROTO_UDP);
				/* If the query failed, return to the loop to try again. */
				if (status != DNS_STATUS_OK)
				{
					dns_log_msg(dns, LOG_INFO, "dns_fqdn_query_server - TCP query failed, retrying.");
					_time_subtract(&time_remaining, dt.tv_sec, dt.tv_usec);
					continue;
				}
				r = dns_parse_packet(rp);
			}

			/*
			 * Check for "recoverable" rcode errors
			 *
			 * We retry (skipping to the next server) for Server Failure,
			 * Not Implemented, and Refused rcode conditions.
			 * Name Error and Format Error are passed back to the caller
			 * - i.e. these are not "recoverable" conditions.
			 */
			rcode = r->header->flags & DNS_FLAGS_RCODE_MASK;
			if ((rcode == DNS_FLAGS_RCODE_SERVER_FAILURE) ||
				(rcode == DNS_FLAGS_RCODE_NOT_IMPLEMENTED) ||
				(rcode == DNS_FLAGS_RCODE_REFUSED))
			{
				status = DNS_STATUS_RECEIVE_FAILED;
				dns_log_msg(dns, LOG_INFO, "dns_fqdn_query_server - rcode %u, retrying.", rcode);
				_time_subtract(&time_remaining, dt.tv_sec, dt.tv_usec);
				continue;
			}
		
			dns_apply_sortlist(dns, r);
			free(rp);
			r->status = status;
			r->server.s_addr = dns->server[q[i].server_index].sin_addr.s_addr;
			free(q);
			free(qp);
#ifdef DEBUG_QUERY
			dns_log_msg(dns, LOG_DEBUG, "dns_fqdn_query_server - reply status %u", status);
#endif
			return r;
		}

		/* Update time remaining for this query */
		_time_subtract(&time_remaining, dt.tv_sec, dt.tv_usec);
	}

	free(q);
	free(qp);

	r = (dns_reply_t *)malloc(sizeof(dns_reply_t));
	memset(r, 0, sizeof(dns_reply_t));
	r->status = status;
#ifdef DEBUG_QUERY
	dns_log_msg(dns, LOG_DEBUG, "dns_fqdn_query_server - reply status %u", status);
#endif
	return r;
}

dns_reply_t *
dns_fqdn_query(dns_handle_t *dns, dns_question_t *dnsq)
{
	return dns_fqdn_query_server(dns, (u_int32_t)-1, dnsq);
}

dns_reply_t *
dns_query_server(dns_handle_t *dns, u_int32_t which, dns_question_t *dnsq)
{
	dns_reply_t *r;
	dns_question_t fqdnq;
#ifdef DNS_EXCLUSION
	u_int32_t ex;
#endif
	u_int32_t i, ndots, len;
	char *p, *name;

#ifdef DNS_EXCLUSION
	/* Check for a qualified name that is specifically excluded */
	for (i = 0; i < dns->exclude_count; i++)
	{
		if (dns_domain_match(dnsq->name, dns->exclude[i])) return NULL;
	}
#endif

	ndots = 0;
	for (p = dnsq->name; *p != '\0'; p++) if (*p == '.') ndots++;

#ifdef DNS_EXCLUSION
	/*
	 * If the "exclusive" option was specified, reject qualified names
	 * that are not in our domain name list
	 */
	if ((ndots != 0) && (dns->exclusive))
	{
		ex = 1;

		if (dns_domain_match(dnsq->name, dns->domain) == 1) ex = 0;
		for (i = 0; (i < dns->search_count) && (ex == 1); i++)
		{
			if (dns_domain_match(dnsq->name, dns->search[i]) == 1) ex = 0;
		}

		if (ex == 1) return NULL;
	}
#endif

	/* .LOCAL USED HERE */
	/*
	 * Reject qualified names other than local multicast domain
	 * if this is a local multicast client
	 */
	if ((ndots != 0) && (!strcasecmp(dns->domain, LOCAL_DOMAIN_STRING)))
	{
		if ((dns_domain_match(dnsq->name, IN_ADDR_DOMAIN_STRING) == 0) && (dns_domain_match(dnsq->name, LOCAL_DOMAIN_STRING) == 0)) return NULL;
	}

	len = strlen(dnsq->name);
	if (dnsq->name[len - 1] == '.')
		return dns_fqdn_query_server(dns, which, dnsq);

	if (ndots >= dns->ias_dots) 
	{
		r = dns_fqdn_query_server(dns, which, dnsq);
		if (r != NULL)
		{
			if ((r->status == DNS_STATUS_OK) && (r->header->ancount != 0)) return r;
			dns_free_reply(r);
		}
	}

	fqdnq.type = dnsq->type;
	fqdnq.class = dnsq->class;
	name = strdup(dnsq->name);
	while (name[strlen(name) - 1] == '.')
	{
		name[strlen(name) - 1] = '\0';
	}

	if (dns->search_count == 0)
	{
		fqdnq.name = malloc(strlen(name) + strlen(dns->domain) + 2);
		sprintf(fqdnq.name, "%s.%s", name, dns->domain);
	
		r = dns_fqdn_query_server(dns, which, &fqdnq);
		free(fqdnq.name);
		if (r != NULL)
		{
			if ((r->status == DNS_STATUS_OK) && (r->header->ancount != 0))
			{
				free(name);
				return r;
			}
			dns_free_reply(r);
		}
	}

	for (i = 0; i < dns->search_count; i++)
	{
		fqdnq.name = malloc(strlen(name) + strlen(dns->search[i]) + 2);
		sprintf(fqdnq.name, "%s.%s", name, dns->search[i]);
	
		r = dns_fqdn_query_server(dns, which, &fqdnq);
		free(fqdnq.name);
		if (r != NULL)
		{
			if ((r->status == DNS_STATUS_OK) && (r->header->ancount != 0))
			{
				free(name);
				return r;
			}
			dns_free_reply(r);
		}
	}

	free(name);
	return NULL;
}

dns_reply_t *
dns_query(dns_handle_t *dns, dns_question_t *dnsq)
{
	return dns_query_server(dns, (u_int32_t)-1, dnsq);
}