* Port evdns with TXT patch into rspamd and adopt it to work separately from libevent

* Add skeleton for spf parser

6 files changed, 4379 insertions, 2 deletions

diff --git a/src/evdns/CMakeLists.txt b/src/evdns/CMakeLists.txt
new file mode 100644
index 000000000..798ece9cc
--- /dev/null
+++ b/src/evdns/CMakeLists.txt
@@ -0,0 +1,4 @@
+# Evdns port to support TXT records
+SET(EVDNSSRC			  evdns.c)
+
+ADD_LIBRARY(rspamd_evdns STATIC ${EVDNSSRC})
diff --git a/src/evdns/evdns.c b/src/evdns/evdns.c
new file mode 100644
index 000000000..435686e42
--- /dev/null
+++ b/src/evdns/evdns.c
@@ -0,0 +1,3277 @@
+/* $Id: evdns.c 6979 2006-08-04 18:31:13Z nickm $ */
+
+/* The original version of this module was written by Adam Langley; for
+ * a history of modifications, check out the subversion logs.
+ *
+ * When editing this module, try to keep it re-mergeable by Adam.  Don't
+ * reformat the whitespace, add Tor dependencies, or so on.
+ *
+ * TODO:
+ *   - Support IPv6 and PTR records.
+ *   - Replace all externally visible magic numbers with #defined constants.
+ *   - Write doccumentation for APIs of all external functions.
+ */
+
+/* Async DNS Library
+ * Adam Langley <agl@imperialviolet.org>
+ * http://www.imperialviolet.org/eventdns.html
+ * Public Domain code
+ *
+ * This software is Public Domain. To view a copy of the public domain dedication,
+ * visit http://creativecommons.org/licenses/publicdomain/ or send a letter to
+ * Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA.
+ *
+ * I ask and expect, but do not require, that all derivative works contain an
+ * attribution similar to:
+ *	Parts developed by Adam Langley <agl@imperialviolet.org>
+ *
+ * You may wish to replace the word "Parts" with something else depending on
+ * the amount of original code.
+ *
+ * (Derivative works does not include programs which link against, run or include
+ * the source verbatim in their source distributions)
+ *
+ * Version: 0.1b
+ */
+
+#include "../config.h"
+#include "../main.h"
+#include "evdns.h"
+
+
+/* for strtok_r */
+#define _REENTRANT
+
+#undef MIN
+#define MIN(a,b) ((a)<(b)?(a):(b))
+
+#ifdef __USE_ISOC99B
+/* libevent doesn't work without this */
+typedef unsigned int uint;
+#endif
+
+#define u64 uint64_t
+#define u32 uint32_t
+#define u16 uint16_t
+#define u8  uint8_t
+
+#ifdef WIN32
+#define open _open
+#define read _read
+#define close _close
+#endif
+
+#define MAX_ADDRS 32  /* maximum number of addresses from a single packet */
+/* which we bother recording */
+
+#define TYPE_A	       EVDNS_TYPE_A
+#define TYPE_CNAME     5
+#define TYPE_TXT	   EVDNS_TYPE_TXT
+#define TYPE_PTR       EVDNS_TYPE_PTR
+#define TYPE_AAAA      EVDNS_TYPE_AAAA
+
+#define CLASS_INET     EVDNS_CLASS_INET
+
+#define EVUTIL_SOCKET_ERROR() (errno)
+#define EVUTIL_SET_SOCKET_ERROR(errcode)		\
+		do { errno = (errcode); } while (0)
+#define evutil_socket_geterror(sock) (errno)
+#define evutil_socket_error_to_string(errcode) (strerror(errcode))
+
+#define evtimer_assign(ev, b, cb, arg)  event_assign(ev, b, -1, 0, cb, arg)
+
+
+#define EVUTIL_UPCAST(ptr, type, field)				\
+	((type *)((char*)ptr) - offsetof(type, field))
+
+
+
+struct evdns_request {
+	u8 *request;  /* the dns packet data */
+	unsigned int request_len;
+	int reissue_count;
+	int tx_count;  /* the number of times that this packet has been sent */
+	unsigned int request_type; /* TYPE_PTR or TYPE_A */
+	void *user_pointer;  /* the pointer given to us for this request */
+	evdns_callback_type user_callback;
+	struct nameserver *ns;	/* the server which we last sent it */
+
+	/* elements used by the searching code */
+	int search_index;
+	struct search_state *search_state;
+	char *search_origname;	/* needs to be free()ed */
+	int search_flags;
+
+	/* these objects are kept in a circular list */
+	struct evdns_request *next, *prev;
+
+	struct event timeout_event;
+
+	u16 trans_id;  /* the transaction id */
+	char request_appended;	/* true if the request pointer is data which follows this struct */
+	char transmit_me;  /* needs to be transmitted */
+
+	struct evdns_base *base;
+};
+
+struct reply {
+	unsigned int type;
+	unsigned int have_answer;
+	union {
+		struct {
+			u32 addrcount;
+			u32 addresses[MAX_ADDRS];
+		} a;
+		struct {
+			u32 addrcount;
+			struct in6_addr addresses[MAX_ADDRS];
+		} aaaa;
+		struct {
+			char name[HOST_NAME_MAX];
+		} ptr;
+		/* TXT field may be longer than 508 bytes, but UDP packets are limited to 512 octets */
+		struct {
+			char data[508];
+		} txt;
+	} data;
+};
+
+struct nameserver {
+	int socket;	 /* a connected UDP socket */
+	struct sockaddr_storage address;
+	socklen_t addrlen;
+	int failed_times;  /* number of times which we have given this server a chance */
+	int timedout;  /* number of times in a row a request has timed out */
+	struct event event;
+	/* these objects are kept in a circular list */
+	struct nameserver *next, *prev;
+	struct event timeout_event;  /* used to keep the timeout for */
+				     /* when we next probe this server. */
+				     /* Valid if state == 0 */
+	/* Outstanding probe request for this nameserver, if any */
+	struct evdns_request *probe_request;
+	char state;  /* zero if we think that this server is down */
+	char choked;  /* true if we have an EAGAIN from this server's socket */
+	char write_waiting;  /* true if we are waiting for EV_WRITE events */
+	struct evdns_base *base;
+};
+
+
+/* Represents a local port where we're listening for DNS requests. Right now, */
+/* only UDP is supported. */
+struct evdns_server_port {
+	int socket; /* socket we use to read queries and write replies. */
+	int refcnt; /* reference count. */
+	char choked; /* Are we currently blocked from writing? */
+	char closing; /* Are we trying to close this port, pending writes? */
+	evdns_request_callback_fn_type user_callback; /* Fn to handle requests */
+	void *user_data; /* Opaque pointer passed to user_callback */
+	struct event event; /* Read/write event */
+	/* circular list of replies that we want to write. */
+	struct server_request *pending_replies;
+	struct event_base *event_base;
+
+};
+
+/* Represents part of a reply being built.	(That is, a single RR.) */
+struct server_reply_item {
+	struct server_reply_item *next; /* next item in sequence. */
+	char *name; /* name part of the RR */
+	u16 type; /* The RR type */
+	u16 class; /* The RR class (usually CLASS_INET) */
+	u32 ttl; /* The RR TTL */
+	char is_name; /* True iff data is a label */
+	u16 datalen; /* Length of data; -1 if data is a label */
+	void *data; /* The contents of the RR */
+};
+
+/* Represents a request that we've received as a DNS server, and holds */
+/* the components of the reply as we're constructing it. */
+struct server_request {
+	/* Pointers to the next and previous entries on the list of replies */
+	/* that we're waiting to write.	 Only set if we have tried to respond */
+	/* and gotten EAGAIN. */
+	struct server_request *next_pending;
+	struct server_request *prev_pending;
+
+	u16 trans_id; /* Transaction id. */
+	struct evdns_server_port *port; /* Which port received this request on? */
+	struct sockaddr_storage addr; /* Where to send the response */
+	socklen_t addrlen; /* length of addr */
+
+	int n_answer; /* how many answer RRs have been set? */
+	int n_authority; /* how many authority RRs have been set? */
+	int n_additional; /* how many additional RRs have been set? */
+
+	struct server_reply_item *answer; /* linked list of answer RRs */
+	struct server_reply_item *authority; /* linked list of authority RRs */
+	struct server_reply_item *additional; /* linked list of additional RRs */
+
+	/* Constructed response.  Only set once we're ready to send a reply. */
+	/* Once this is set, the RR fields are cleared, and no more should be set. */
+	char *response;
+	size_t response_len;
+
+	/* Caller-visible fields: flags, questions. */
+	struct evdns_server_request base;
+};
+
+struct evdns_base {
+	/* An array of n_req_heads circular lists for inflight requests.
+	 * Each inflight request req is in req_heads[req->trans_id % n_req_heads].
+	 */
+	struct evdns_request **req_heads;
+	/* A circular list of requests that we're waiting to send, but haven't
+	 * sent yet because there are too many requests inflight */
+	struct evdns_request *req_waiting_head;
+	/* A circular list of nameservers. */
+	struct nameserver *server_head;
+	int n_req_heads;
+
+	struct event_base *event_base;
+
+	/* The number of good nameservers that we have */
+	int global_good_nameservers;
+
+	/* inflight requests are contained in the req_head list */
+	/* and are actually going out across the network */
+	int global_requests_inflight;
+	/* requests which aren't inflight are in the waiting list */
+	/* and are counted here */
+	int global_requests_waiting;
+
+	int global_max_requests_inflight;
+
+	struct timeval global_timeout;	/* 5 seconds */
+	int global_max_reissues;  /* a reissue occurs when we get some errors from the server */
+	int global_max_retransmits;  /* number of times we'll retransmit a request which timed out */
+	/* number of timeouts in a row before we consider this server to be down */
+	int global_max_nameserver_timeout;
+	/* true iff we will use the 0x20 hack to prevent poisoning attacks. */
+	int global_randomize_case;
+
+	/** Port to bind to for outgoing DNS packets. */
+	struct sockaddr_storage global_outgoing_address;
+	/** socklen_t for global_outgoing_address. 0 if it isn't set. */
+	socklen_t global_outgoing_addrlen;
+
+	struct search_state *global_search_state;
+
+#ifndef _EVENT_DISABLE_THREAD_SUPPORT
+	void *lock;
+	int lock_count;
+#endif
+};
+
+static struct evdns_base *current_base = NULL;
+
+/* Given a pointer to an evdns_server_request, get the corresponding */
+/* server_request. */
+#define TO_SERVER_REQUEST(base_ptr)					\
+	((struct server_request*)					\
+	  (((char*)(base_ptr) - offsetof(struct server_request, base))))
+
+#define REQ_HEAD(base, id) ((base)->req_heads[id % (base)->n_req_heads])
+
+/* These are the timeout values for nameservers. If we find a nameserver is down */
+/* we try to probe it at intervals as given below. Values are in seconds. */
+static const struct timeval global_nameserver_timeouts[] = {{10, 0}, {60, 0}, {300, 0}, {900, 0}, {3600, 0}};
+static const int global_nameserver_timeouts_length = sizeof(global_nameserver_timeouts)/sizeof(struct timeval);
+
+static struct nameserver *nameserver_pick(struct evdns_base *base);
+static void evdns_request_insert(struct evdns_request *req, struct evdns_request **head);
+static void evdns_request_remove(struct evdns_request *req, struct evdns_request **head);
+static void nameserver_ready_callback(int fd, short events, void *arg);
+static int evdns_transmit(struct evdns_base *base);
+static int evdns_request_transmit(struct evdns_request *req);
+static void nameserver_send_probe(struct nameserver *const ns);
+static void search_request_finished(struct evdns_request *const);
+static int search_try_next(struct evdns_request *const req);
+static struct evdns_request *search_request_new(struct evdns_base *base, int type, const char *const name, int flags, evdns_callback_type user_callback, void *user_arg);
+static void evdns_requests_pump_waiting_queue(struct evdns_base *base);
+static u16 transaction_id_pick(struct evdns_base *base);
+static struct evdns_request *request_new(struct evdns_base *base, int type, const char *name, int flags, evdns_callback_type callback, void *ptr);
+static void request_submit(struct evdns_request *const req);
+
+static int server_request_free(struct server_request *req);
+static void server_request_free_answers(struct server_request *req);
+static void server_port_free(struct evdns_server_port *port);
+static void server_port_ready_callback(int fd, short events, void *arg);
+static int evdns_base_resolv_conf_parse_impl(struct evdns_base *base, int flags, const char *const filename);
+static int evdns_base_set_option_impl(struct evdns_base *base,
+    const char *option, const char *val, int flags);
+static void evdns_base_free_and_unlock(struct evdns_base *base, int fail_requests);
+
+static int strtoint(const char *const str);
+
+#define CLOSE_SOCKET(s) close(s)
+
+
+static int
+evutil_parse_sockaddr_port(const char *ip_as_string, struct sockaddr *out, int *outlen)
+{
+	int port;
+	char buf[128];
+	const char *cp, *addr_part, *port_part;
+	int is_ipv6;
+	/* recognized formats are:
+	 * [ipv6]:port
+	 * ipv6
+	 * [ipv6]
+	 * ipv4:port
+	 * ipv4
+	 */
+
+	cp = strchr(ip_as_string, ':');
+	if (*ip_as_string == '[') {
+		int len;
+		if (!(cp = strchr(ip_as_string, ']'))) {
+			return -1;
+		}
+		len = cp-(ip_as_string + 1);
+		if (len > (int)sizeof(buf)-1) {
+			return -1;
+		}
+		memcpy(buf, ip_as_string+1, len);
+		buf[len] = '\0';
+		addr_part = buf;
+		if (cp[1] == ':')
+			port_part = cp+2;
+		else
+			port_part = NULL;
+		is_ipv6 = 1;
+	} else if (cp && strchr(cp+1, ':')) {
+		is_ipv6 = 1;
+		addr_part = ip_as_string;
+		port_part = NULL;
+	} else if (cp) {
+		is_ipv6 = 0;
+		if (cp - ip_as_string > (int)sizeof(buf)-1) {
+			return -1;
+		}
+		memcpy(buf, ip_as_string, cp-ip_as_string);
+		buf[cp-ip_as_string] = '\0';
+		addr_part = buf;
+		port_part = cp+1;
+	} else {
+		addr_part = ip_as_string;
+		port_part = NULL;
+		is_ipv6 = 0;
+	}
+
+	if (port_part == NULL) {
+		port = 0;
+	} else {
+		port = atoi(port_part);
+		if (port <= 0 || port > 65535) {
+			return -1;
+		}
+	}
+
+	if (!addr_part)
+		return -1; /* Should be impossible. */
+
+	struct sockaddr_in sin;
+	memset(&sin, 0, sizeof(sin));
+	sin.sin_family = AF_INET;
+	sin.sin_port = htons(port);
+	if (1 != inet_pton(AF_INET, addr_part, &sin.sin_addr))
+		return -1;
+	if (sizeof(sin) > *outlen)
+		return -1;
+	memset(out, 0, *outlen);
+	memcpy(out, &sin, sizeof(sin));
+			*outlen = sizeof(sin);
+	return 0;
+}
+
+static int
+evutil_sockaddr_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2,
+    int include_port)
+{
+	int r;
+	if (0 != (r = (sa1->sa_family - sa2->sa_family)))
+		return r;
+
+	if (sa1->sa_family == AF_INET) {
+		const struct sockaddr_in *sin1, *sin2;
+		sin1 = (const struct sockaddr_in *)sa1;
+		sin2 = (const struct sockaddr_in *)sa2;
+		if (sin1->sin_addr.s_addr < sin2->sin_addr.s_addr)
+			return -1;
+		else if (sin1->sin_addr.s_addr > sin2->sin_addr.s_addr)
+			return 1;
+		else if (include_port &&
+		    (r = ((int)sin1->sin_port - (int)sin2->sin_port)))
+			return r;
+		else
+			return 0;
+	}
+	return 1;
+}
+
+static void
+event_assign(struct event *ev, struct event_base *base, int fd, short events, void (*cb)(int, short, void *), void *arg)
+{
+	event_set(ev, fd, events, cb, arg);
+	if (base != NULL)
+		g_assert(event_base_set(base, ev) == 0);
+}
+
+
+static const char *
+debug_ntoa(u32 address)
+{
+	static char buf[32];
+	u32 a = ntohl(address);
+	snprintf(buf, sizeof(buf), "%d.%d.%d.%d",
+					(int)(u8)((a>>24)&0xff),
+					(int)(u8)((a>>16)&0xff),
+					(int)(u8)((a>>8 )&0xff),
+					(int)(u8)((a	)&0xff));
+	return buf;
+}
+
+static const char *
+debug_ntop(const struct sockaddr *sa)
+{
+	if (sa->sa_family == AF_INET) {
+		struct sockaddr_in *sin = (struct sockaddr_in *) sa;
+		return debug_ntoa(sin->sin_addr.s_addr);
+	}
+#ifdef AF_INET6
+	if (sa->sa_family == AF_INET6) {
+		static char buf[128];
+		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) sa;
+		const char *result;
+		result = inet_ntop(AF_INET6, &sin6->sin6_addr, buf, sizeof(buf));
+		return result ? result : "unknown";
+	}
+#endif
+	return "<unknown>";
+}
+
+
+
+/* This walks the list of inflight requests to find the */
+/* one with a matching transaction id. Returns NULL on */
+/* failure */
+static struct evdns_request *
+request_find_from_trans_id(struct evdns_base *base, u16 trans_id) {
+	struct evdns_request *req = REQ_HEAD(base, trans_id);
+	struct evdns_request *const started_at = req;
+
+	if (req) {
+		do {
+			if (req->trans_id == trans_id) return req;
+			req = req->next;
+		} while (req != started_at);
+	}
+
+	return NULL;
+}
+
+/* a libevent callback function which is called when a nameserver */
+/* has gone down and we want to test if it has came back to life yet */
+static void
+nameserver_prod_callback(int fd, short events, void *arg) {
+	struct nameserver *const ns = (struct nameserver *) arg;
+	(void)fd;
+	(void)events;
+
+	nameserver_send_probe(ns);
+}
+
+/* a libevent callback which is called when a nameserver probe (to see if */
+/* it has come back to life) times out. We increment the count of failed_times */
+/* and wait longer to send the next probe packet. */
+static void
+nameserver_probe_failed(struct nameserver *const ns) {
+	const struct timeval * timeout;
+
+	(void) evtimer_del(&ns->timeout_event);
+	if (ns->state == 1) {
+		/* This can happen if the nameserver acts in a way which makes us mark */
+		/* it as bad and then starts sending good replies. */
+		return;
+	}
+
+	timeout =
+		&global_nameserver_timeouts[MIN(ns->failed_times,
+										global_nameserver_timeouts_length - 1)];
+	ns->failed_times++;
+
+	if (evtimer_add(&ns->timeout_event, (struct timeval *) timeout) < 0) {
+	 msg_warn( 
+	      "Error from libevent when adding timer event for %s",
+	      debug_ntop((struct sockaddr *)&ns->address));
+	  /* ???? Do more? */
+	}
+}
+
+/* called when a nameserver has been deemed to have failed. For example, too */
+/* many packets have timed out etc */
+static void
+nameserver_failed(struct nameserver *const ns, const char *msg) {
+	struct evdns_request *req, *started_at;
+	struct evdns_base *base = ns->base;
+	int i;
+
+	/* if this nameserver has already been marked as failed */
+	/* then don't do anything */
+	if (!ns->state) return;
+
+	base->global_good_nameservers--;
+	g_assert(base->global_good_nameservers >= 0);
+
+	ns->state = 0;
+	ns->failed_times = 1;
+
+	if (evtimer_add(&ns->timeout_event, (struct timeval *) &global_nameserver_timeouts[0]) < 0) {
+		msg_warn(	
+		    "Error from libevent when adding timer event for %s",
+		    debug_ntop((struct sockaddr*)&ns->address));
+		/* ???? Do more? */
+	}
+
+	/* walk the list of inflight requests to see if any can be reassigned to */
+	/* a different server. Requests in the waiting queue don't have a */
+	/* nameserver assigned yet */
+
+	/* if we don't have *any* good nameservers then there's no point */
+	/* trying to reassign requests to one */
+	if (!base->global_good_nameservers) return;
+
+	for (i = 0; i < base->n_req_heads; ++i) {
+		req = started_at = base->req_heads[i];
+		if (req) {
+			do {
+				if (req->tx_count == 0 && req->ns == ns) {
+					/* still waiting to go out, can be moved */
+					/* to another server */
+					req->ns = nameserver_pick(base);
+				}
+				req = req->next;
+			} while (req != started_at);
+		}
+	}
+}
+
+static void
+nameserver_up(struct nameserver *const ns) {
+	if (ns->state) return;
+	evtimer_del(&ns->timeout_event);
+	if (ns->probe_request) {
+		evdns_cancel_request(ns->base, ns->probe_request);
+		ns->probe_request = NULL;
+	}
+	ns->state = 1;
+	ns->failed_times = 0;
+	ns->timedout = 0;
+	ns->base->global_good_nameservers++;
+}
+
+static void
+request_trans_id_set(struct evdns_request *const req, const u16 trans_id) {
+	req->trans_id = trans_id;
+	*((u16 *) req->request) = htons(trans_id);
+}
+
+/* Called to remove a request from a list and dealloc it. */
+/* head is a pointer to the head of the list it should be */
+/* removed from or NULL if the request isn't in a list. */
+static void
+request_finished(struct evdns_request *const req, struct evdns_request **head) {
+	struct evdns_base *base = req->base;
+	int was_inflight = (head != &base->req_waiting_head);
+	if (head)
+		evdns_request_remove(req, head);
+
+	search_request_finished(req);
+	if (was_inflight) {
+		evtimer_del(&req->timeout_event);
+		base->global_requests_inflight--;
+	} else {
+		base->global_requests_waiting--;
+	}
+
+	if (!req->request_appended) {
+		/* need to free the request data on it's own */
+		g_free(req->request);
+	} else {
+		/* the request data is appended onto the header */
+		/* so everything gets free()ed when we: */
+	}
+
+	g_free(req);
+
+	evdns_requests_pump_waiting_queue(base);
+}
+
+/* This is called when a server returns a funny error code. */
+/* We try the request again with another server. */
+/* */
+/* return: */
+/*   0 ok */
+/*   1 failed/reissue is pointless */
+static int
+request_reissue(struct evdns_request *req) {
+	const struct nameserver *const last_ns = req->ns;
+	/* the last nameserver should have been marked as failing */
+	/* by the caller of this function, therefore pick will try */
+	/* not to return it */
+	req->ns = nameserver_pick(req->base);
+	if (req->ns == last_ns) {
+		/* ... but pick did return it */
+		/* not a lot of point in trying again with the */
+		/* same server */
+		return 1;
+	}
+
+	req->reissue_count++;
+	req->tx_count = 0;
+	req->transmit_me = 1;
+
+	return 0;
+}
+
+/* this function looks for space on the inflight queue and promotes */
+/* requests from the waiting queue if it can. */
+static void
+evdns_requests_pump_waiting_queue(struct evdns_base *base) {
+	while (base->global_requests_inflight < base->global_max_requests_inflight &&
+		   base->global_requests_waiting) {
+		struct evdns_request *req;
+		/* move a request from the waiting queue to the inflight queue */
+		g_assert(base->req_waiting_head);
+		req = base->req_waiting_head;
+		evdns_request_remove(req, &base->req_waiting_head);
+
+		base->global_requests_waiting--;
+		base->global_requests_inflight++;
+
+		req->ns = nameserver_pick(base);
+		request_trans_id_set(req, transaction_id_pick(base));
+
+		evdns_request_insert(req, &REQ_HEAD(base, req->trans_id));
+		evdns_request_transmit(req);
+		evdns_transmit(base);
+	}
+}
+
+static void
+reply_callback(struct evdns_request *const req, u32 ttl, u32 err, struct reply *reply) {
+	switch (req->request_type) {
+	case TYPE_A:
+		if (reply)
+			req->user_callback(DNS_ERR_NONE, DNS_IPv4_A,
+							   reply->data.a.addrcount, ttl,
+						 reply->data.a.addresses,
+							   req->user_pointer);
+		else
+			req->user_callback(err, 0, 0, 0, NULL, req->user_pointer);
+		return;
+	case TYPE_PTR:
+		if (reply) {
+			char *name = reply->data.ptr.name;
+			req->user_callback(DNS_ERR_NONE, DNS_PTR, 1, ttl,
+							   &name, req->user_pointer);
+		} else {
+			req->user_callback(err, 0, 0, 0, NULL,
+							   req->user_pointer);
+		}
+		return;
+	case TYPE_AAAA:
+		if (reply)
+			req->user_callback(DNS_ERR_NONE, DNS_IPv6_AAAA,
+							   reply->data.aaaa.addrcount, ttl,
+							   reply->data.aaaa.addresses,
+							   req->user_pointer);
+		else
+			req->user_callback(err, 0, 0, 0, NULL, req->user_pointer);
+                return;
+	case TYPE_TXT:
+		if (reply) {
+			char *data = reply->data.txt.data;
+			req->user_callback(DNS_ERR_NONE, DNS_TXT, 1, ttl,
+								&data, req->user_pointer);
+		}
+		else {
+			req->user_callback(err, 0, 0, 0, NULL, req->user_pointer);
+		}
+		return; 
+	}
+	g_assert(0);
+}
+
+/* this processes a parsed reply packet */
+static void
+reply_handle(struct evdns_request *const req, u16 flags, u32 ttl, struct reply *reply) {
+	int error;
+	static const int error_codes[] = {
+		DNS_ERR_FORMAT, DNS_ERR_SERVERFAILED, DNS_ERR_NOTEXIST,
+		DNS_ERR_NOTIMPL, DNS_ERR_REFUSED
+	};
+
+
+	if (flags & 0x020f || !reply || !reply->have_answer) {
+		/* there was an error */
+		if (flags & 0x0200) {
+			error = DNS_ERR_TRUNCATED;
+		} else {
+			u16 error_code = (flags & 0x000f) - 1;
+			if (error_code > 4) {
+				error = DNS_ERR_UNKNOWN;
+			} else {
+				error = error_codes[error_code];
+			}
+		}
+
+		switch(error) {
+		case DNS_ERR_NOTIMPL:
+		case DNS_ERR_REFUSED:
+			/* we regard these errors as marking a bad nameserver */
+			if (req->reissue_count < req->base->global_max_reissues) {
+				char msg[64];
+				snprintf(msg, sizeof(msg), "Bad response %d (%s)",
+					 error, evdns_err_to_string(error));
+				nameserver_failed(req->ns, msg);
+				if (!request_reissue(req)) return;
+			}
+			break;
+		case DNS_ERR_SERVERFAILED:
+			/* rcode 2 (servfailed) sometimes means "we
+			 * are broken" and sometimes (with some binds)
+			 * means "that request was very confusing."
+			 * Treat this as a timeout, not a failure.
+			 */
+			break;
+		default:
+			/* we got a good reply from the nameserver */
+			nameserver_up(req->ns);
+		}
+
+		if (req->search_state && req->request_type != TYPE_PTR) {
+			/* if we have a list of domains to search in,
+			 * try the next one */
+			if (!search_try_next(req)) {
+				/* a new request was issued so this
+				 * request is finished and */
+				/* the user callback will be made when
+				 * that request (or a */
+				/* child of it) finishes. */
+				request_finished(req, &REQ_HEAD(req->base, req->trans_id));
+				return;
+			}
+		}
+
+		/* all else failed. Pass the failure up */
+		reply_callback(req, 0, error, NULL);
+		request_finished(req, &REQ_HEAD(req->base, req->trans_id));
+	} else {
+		/* all ok, tell the user */
+		reply_callback(req, ttl, 0, reply);
+		if (req == req->ns->probe_request)
+			req->ns->probe_request = NULL; /* Avoid double-free */
+		nameserver_up(req->ns);
+		request_finished(req, &REQ_HEAD(req->base, req->trans_id));
+	}
+}
+
+static int
+name_parse(u8 *packet, int length, int *idx, char *name_out, int name_out_len) {
+	int name_end = -1;
+	int j = *idx;
+	int ptr_count = 0;
+#define GET32(x) do { if (j + 4 > length) goto err; memcpy(&_t32, packet + j, 4); j += 4; x = ntohl(_t32); } while(0)
+#define GET16(x) do { if (j + 2 > length) goto err; memcpy(&_t, packet + j, 2); j += 2; x = ntohs(_t); } while(0)
+#define GET8(x) do { if (j >= length) goto err; x = packet[j++]; } while(0)
+
+	char *cp = name_out;
+	const char *const end = name_out + name_out_len;
+
+	/* Normally, names are a series of length prefixed strings terminated */
+	/* with a length of 0 (the lengths are u8's < 63). */
+	/* However, the length can start with a pair of 1 bits and that */
+	/* means that the next 14 bits are a pointer within the current */
+	/* packet. */
+
+	for(;;) {
+		u8 label_len;
+		if (j >= length) return -1;
+		GET8(label_len);
+		if (!label_len) break;
+		if (label_len & 0xc0) {
+			u8 ptr_low;
+			GET8(ptr_low);
+			if (name_end < 0) name_end = j;
+			j = (((int)label_len & 0x3f) << 8) + ptr_low;
+			/* Make sure that the target offset is in-bounds. */
+			if (j < 0 || j >= length) return -1;
+			/* If we've jumped more times than there are characters in the
+			 * message, we must have a loop. */
+			if (++ptr_count > length) return -1;
+			continue;
+		}
+		if (label_len > 63) return -1;
+		if (cp != name_out) {
+			if (cp + 1 >= end) return -1;
+			*cp++ = '.';
+		}
+		if (cp + label_len >= end) return -1;
+		memcpy(cp, packet + j, label_len);
+		cp += label_len;
+		j += label_len;
+	}
+	if (cp >= end) return -1;
+	*cp = '\0';
+	if (name_end < 0)
+		*idx = j;
+	else
+		*idx = name_end;
+	return 0;
+ err:
+	return -1;
+}
+
+/* parses a raw request from a nameserver */
+static int
+reply_parse(struct evdns_base *base, u8 *packet, int length) {
+	int j = 0, k = 0;  /* index into packet */
+	u16 _t;	 /* used by the macros */
+	u32 _t32;  /* used by the macros */
+	char tmp_name[256], cmp_name[256]; /* used by the macros */
+	int name_matches = 0;
+
+	u16 trans_id, questions, answers, authority, additional, datalength;
+	u16 flags = 0;
+	u32 ttl, ttl_r = 0xffffffff;
+	struct reply reply;
+	struct evdns_request *req = NULL;
+	unsigned int i;
+
+
+	GET16(trans_id);
+	GET16(flags);
+	GET16(questions);
+	GET16(answers);
+	GET16(authority);
+	GET16(additional);
+	(void) authority; /* suppress "unused variable" warnings. */
+	(void) additional; /* suppress "unused variable" warnings. */
+
+	req = request_find_from_trans_id(base, trans_id);
+	if (!req) return -1;
+	g_assert(req->base == base);
+
+	memset(&reply, 0, sizeof(reply));
+
+	/* If it's not an answer, it doesn't correspond to any request. */
+	if (!(flags & 0x8000)) return -1;  /* must be an answer */
+	if (flags & 0x020f) {
+		/* there was an error */
+		goto err;
+	}
+	/* if (!answers) return; */  /* must have an answer of some form */
+
+	/* This macro skips a name in the DNS reply. */
+#define SKIP_NAME						\
+	do { tmp_name[0] = '\0';				\
+		if (name_parse(packet, length, &j, tmp_name,	\
+			sizeof(tmp_name))<0)			\
+			goto err;				\
+	} while(0)
+#define TEST_NAME							\
+	do { tmp_name[0] = '\0';					\
+		cmp_name[0] = '\0';					\
+		k = j;							\
+		if (name_parse(packet, length, &j, tmp_name,		\
+			sizeof(tmp_name))<0)				\
+			goto err;					\
+		if (name_parse(req->request, req->request_len, &k,	\
+			cmp_name, sizeof(cmp_name))<0)			\
+			goto err;					\
+		if (base->global_randomize_case) {			\
+			if (strcmp(tmp_name, cmp_name) == 0)		\
+				name_matches = 1;			\
+		} else {						\
+			if (g_ascii_strcasecmp(tmp_name, cmp_name) == 0) \
+				name_matches = 1;			\
+		}							\
+	} while(0)
+
+	reply.type = req->request_type;
+
+	/* skip over each question in the reply */
+	for (i = 0; i < questions; ++i) {
+		/* the question looks like
+		 *   <label:name><u16:type><u16:class>
+		 */
+		TEST_NAME;
+		j += 4;
+		if (j >= length) goto err;
+	}
+
+	if (!name_matches)
+		goto err;
+
+	/* now we have the answer section which looks like
+	 * <label:name><u16:type><u16:class><u32:ttl><u16:len><data...>
+	 */
+
+	for (i = 0; i < answers; ++i) {
+		u16 type, class;
+
+		SKIP_NAME;
+		GET16(type);
+		GET16(class);
+		GET32(ttl);
+		GET16(datalength);
+
+		if (type == TYPE_A && class == CLASS_INET) {
+			int addrcount, addrtocopy;
+			if (req->request_type != TYPE_A) {
+				j += datalength; continue;
+			}
+			if ((datalength & 3) != 0) /* not an even number of As. */
+			    goto err;
+			addrcount = datalength >> 2;
+			addrtocopy = MIN(MAX_ADDRS - reply.data.a.addrcount, (unsigned)addrcount);
+
+			ttl_r = MIN(ttl_r, ttl);
+			/* we only bother with the first four addresses. */
+			if (j + 4*addrtocopy > length) goto err;
+			memcpy(&reply.data.a.addresses[reply.data.a.addrcount],
+				   packet + j, 4*addrtocopy);
+			j += 4*addrtocopy;
+			reply.data.a.addrcount += addrtocopy;
+			reply.have_answer = 1;
+			if (reply.data.a.addrcount == MAX_ADDRS) break;
+		} else if (type == TYPE_PTR && class == CLASS_INET) {
+			if (req->request_type != TYPE_PTR) {
+				j += datalength; continue;
+			}
+			if (name_parse(packet, length, &j, reply.data.ptr.name,
+						   sizeof(reply.data.ptr.name))<0)
+				goto err;
+			ttl_r = MIN(ttl_r, ttl);
+			reply.have_answer = 1;
+			break;
+		} else if (type == TYPE_AAAA && class == CLASS_INET) {
+			int addrcount, addrtocopy;
+			if (req->request_type != TYPE_AAAA) {
+				j += datalength; continue;
+			}
+			if ((datalength & 15) != 0) /* not an even number of AAAAs. */
+				goto err;
+			addrcount = datalength >> 4;  /* each address is 16 bytes long */
+			addrtocopy = MIN(MAX_ADDRS - reply.data.aaaa.addrcount, (unsigned)addrcount);
+			ttl_r = MIN(ttl_r, ttl);
+
+			/* we only bother with the first four addresses. */
+			if (j + 16*addrtocopy > length) goto err;
+			memcpy(&reply.data.aaaa.addresses[reply.data.aaaa.addrcount],
+				   packet + j, 16*addrtocopy);
+			reply.data.aaaa.addrcount += addrtocopy;
+			j += 16*addrtocopy;
+			reply.have_answer = 1;
+			if (reply.data.aaaa.addrcount == MAX_ADDRS) break;
+		} else if (type == TYPE_TXT) {
+			if (req->request_type != TYPE_TXT) {
+				j += datalength;
+				continue;
+			}
+			memcpy(&reply.data.txt.data, packet + j + 1, MIN(sizeof(reply.data.txt.data), datalength - 1));
+			j += datalength;
+			ttl_r = MIN(ttl_r, ttl);
+			reply.have_answer = 1;
+			break;
+		} else {
+			/* skip over any other type of resource */
+			j += datalength;
+		}
+	}
+
+	reply_handle(req, flags, ttl_r, &reply);
+	return 0;
+ err:
+	if (req)
+		reply_handle(req, flags, 0, NULL);
+	return -1;
+}
+
+/* Parse a raw request (packet,length) sent to a nameserver port (port) from */
+/* a DNS client (addr,addrlen), and if it's well-formed, call the corresponding */
+/* callback. */
+static int
+request_parse(u8 *packet, int length, struct evdns_server_port *port, struct sockaddr *addr, socklen_t addrlen)
+{
+	int j = 0;	/* index into packet */
+	u16 _t;	 /* used by the macros */
+	char tmp_name[256]; /* used by the macros */
+
+	int i;
+	u16 trans_id, flags, questions, answers, authority, additional;
+	struct server_request *server_req = NULL;
+
+
+	/* Get the header fields */
+	GET16(trans_id);
+	GET16(flags);
+	GET16(questions);
+	GET16(answers);
+	GET16(authority);
+	GET16(additional);
+
+	if (flags & 0x8000) return -1; /* Must not be an answer. */
+	flags &= 0x0110; /* Only RD and CD get preserved. */
+
+	server_req = g_malloc(sizeof(struct server_request));
+	if (server_req == NULL) return -1;
+	memset(server_req, 0, sizeof(struct server_request));
+
+	server_req->trans_id = trans_id;
+	memcpy(&server_req->addr, addr, addrlen);
+	server_req->addrlen = addrlen;
+
+	server_req->base.flags = flags;
+	server_req->base.nquestions = 0;
+	server_req->base.questions = g_malloc(sizeof(struct evdns_server_question *) * questions);
+	if (server_req->base.questions == NULL)
+		goto err;
+
+	for (i = 0; i < questions; ++i) {
+		u16 type, class;
+		struct evdns_server_question *q;
+		int namelen;
+		if (name_parse(packet, length, &j, tmp_name, sizeof(tmp_name))<0)
+			goto err;
+		GET16(type);
+		GET16(class);
+		namelen = strlen(tmp_name);
+		q = g_malloc(sizeof(struct evdns_server_question) + namelen);
+		if (!q)
+			goto err;
+		q->type = type;
+		q->dns_question_class = class;
+		memcpy(q->name, tmp_name, namelen+1);
+		server_req->base.questions[server_req->base.nquestions++] = q;
+	}
+
+	/* Ignore answers, authority, and additional. */
+
+	server_req->port = port;
+	port->refcnt++;
+
+	/* Only standard queries are supported. */
+	if (flags & 0x7800) {
+		evdns_server_request_respond(&(server_req->base), DNS_ERR_NOTIMPL);
+		return -1;
+	}
+
+	port->user_callback(&(server_req->base), port->user_data);
+
+	return 0;
+err:
+	if (server_req) {
+		if (server_req->base.questions) {
+			for (i = 0; i < server_req->base.nquestions; ++i)
+				g_free(server_req->base.questions[i]);
+			g_free(server_req->base.questions);
+		}
+		g_free(server_req);
+	}
+	return -1;
+
+#undef SKIP_NAME
+#undef GET32
+#undef GET16
+#undef GET8
+}
+
+static u16
+default_transaction_id_fn(void)
+{
+	u16 trans_id;
+	struct timespec ts;
+	static int clkid = -1;
+	if (clkid == -1) {
+		clkid = CLOCK_REALTIME;
+		if (clock_gettime(CLOCK_MONOTONIC, &ts) != -1)
+			clkid = CLOCK_MONOTONIC;
+	}
+	clock_gettime(clkid, &ts);
+	trans_id = ts.tv_nsec & 0xffff;
+
+	return trans_id;
+}
+
+static uint16_t (*trans_id_function)(void) = default_transaction_id_fn;
+
+static void
+default_random_bytes_fn(char *buf, size_t n)
+{
+	unsigned i;
+	for (i = 0; i < n; i += 2) {
+		u16 tid = trans_id_function();
+		buf[i] = (tid >> 8) & 0xff;
+		if (i+1<n)
+			buf[i+1] = tid & 0xff;
+	}
+}
+
+static void (*rand_bytes_function)(char *buf, size_t n) =
+	default_random_bytes_fn;
+
+static u16
+trans_id_from_random_bytes_fn(void)
+{
+	u16 tid;
+	rand_bytes_function((char*) &tid, sizeof(tid));
+	return tid;
+}
+
+void
+evdns_set_transaction_id_fn(uint16_t (*fn)(void))
+{
+	if (fn)
+		trans_id_function = fn;
+	else
+		trans_id_function = default_transaction_id_fn;
+	rand_bytes_function = default_random_bytes_fn;
+}
+
+void
+evdns_set_random_bytes_fn(void (*fn)(char *, size_t))
+{
+	rand_bytes_function = fn;
+	trans_id_function = trans_id_from_random_bytes_fn;
+}
+
+/* Try to choose a strong transaction id which isn't already in flight */
+static u16
+transaction_id_pick(struct evdns_base *base) {
+	for (;;) {
+		u16 trans_id = trans_id_function();
+
+		if (trans_id == 0xffff) continue;
+		/* now check to see if that id is already inflight */
+		if (request_find_from_trans_id(base, trans_id) == NULL)
+			return trans_id;
+	}
+}
+
+/* choose a namesever to use. This function will try to ignore */
+/* nameservers which we think are down and load balance across the rest */
+/* by updating the server_head global each time. */
+static struct nameserver *
+nameserver_pick(struct evdns_base *base) {
+	struct nameserver *started_at = base->server_head, *picked;
+	if (!base->server_head) return NULL;
+
+	/* if we don't have any good nameservers then there's no */
+	/* point in trying to find one. */
+	if (!base->global_good_nameservers) {
+		base->server_head = base->server_head->next;
+		return base->server_head;
+	}
+
+	/* remember that nameservers are in a circular list */
+	for (;;) {
+		if (base->server_head->state) {
+			/* we think this server is currently good */
+			picked = base->server_head;
+			base->server_head = base->server_head->next;
+			return picked;
+		}
+
+		base->server_head = base->server_head->next;
+		if (base->server_head == started_at) {
+			/* all the nameservers seem to be down */
+			/* so we just return this one and hope for the */
+			/* best */
+			g_assert(base->global_good_nameservers == 0);
+			picked = base->server_head;
+			base->server_head = base->server_head->next;
+			return picked;
+		}
+	}
+}
+
+/* this is called when a namesever socket is ready for reading */
+static void
+nameserver_read(struct nameserver *ns) {
+	struct sockaddr_storage ss;
+	socklen_t addrlen = sizeof(ss);
+	u8 packet[1500];
+
+	for (;;) {
+		const int r = recvfrom(ns->socket, packet, sizeof(packet), 0,
+		    (struct sockaddr*)&ss, &addrlen);
+		if (r < 0) {
+			int err = evutil_socket_geterror(ns->socket);
+			nameserver_failed(ns,
+			    evutil_socket_error_to_string(err));
+			return;
+		}
+		if (evutil_sockaddr_cmp((struct sockaddr*)&ss,
+			(struct sockaddr*)&ns->address, 0)) {
+			msg_warn("Address mismatch on received "
+			    "DNS packet.  Apparent source was %s",
+			    debug_ntop((struct sockaddr*)&ss));
+			return;
+		}
+
+		ns->timedout = 0;
+		reply_parse(ns->base, packet, r);
+	}
+}
+
+/* Read a packet from a DNS client on a server port s, parse it, and */
+/* act accordingly. */
+static void
+server_port_read(struct evdns_server_port *s) {
+	u8 packet[1500];
+	struct sockaddr_storage addr;
+	socklen_t addrlen;
+	int r;
+
+	for (;;) {
+		addrlen = sizeof(struct sockaddr_storage);
+		r = recvfrom(s->socket, packet, sizeof(packet), 0,
+					 (struct sockaddr*) &addr, &addrlen);
+		if (r < 0) {
+			int err = evutil_socket_geterror(s->socket);
+			msg_warn("Error %s (%d) while reading request.",
+				evutil_socket_error_to_string(err), err);
+			return;
+		}
+		request_parse(packet, r, s, (struct sockaddr*) &addr, addrlen);
+	}
+}
+
+/* Try to write all pending replies on a given DNS server port. */
+static void
+server_port_flush(struct evdns_server_port *port)
+{
+	while (port->pending_replies) {
+		struct server_request *req = port->pending_replies;
+		int r = sendto(port->socket, req->response, req->response_len, 0,
+			   (struct sockaddr*) &req->addr, req->addrlen);
+		if (r < 0) {
+			int err = evutil_socket_geterror(port->socket);
+			msg_warn("Error %s (%d) while writing response to port; dropping", evutil_socket_error_to_string(err), err);
+		}
+		if (server_request_free(req)) {
+			/* we released the last reference to req->port. */
+			return;
+		}
+	}
+
+	/* We have no more pending requests; stop listening for 'writeable' events. */
+	(void) event_del(&port->event);
+	event_assign(&port->event, port->event_base,
+				 port->socket, EV_READ | EV_PERSIST,
+				 server_port_ready_callback, port);
+
+	if (event_add(&port->event, NULL) < 0) {
+		msg_warn("Error from libevent when adding event for DNS server.");
+		/* ???? Do more? */
+	}
+}
+
+/* set if we are waiting for the ability to write to this server. */
+/* if waiting is true then we ask libevent for EV_WRITE events, otherwise */
+/* we stop these events. */
+static void
+nameserver_write_waiting(struct nameserver *ns, char waiting) {
+	if (ns->write_waiting == waiting) return;
+
+	ns->write_waiting = waiting;
+	(void) event_del(&ns->event);
+	event_assign(&ns->event, ns->base->event_base,
+	    ns->socket, EV_READ | (waiting ? EV_WRITE : 0) | EV_PERSIST,
+	    nameserver_ready_callback, ns);
+	if (event_add(&ns->event, NULL) < 0) {
+	  msg_warn("Error from libevent when adding event for %s",
+	      debug_ntop((struct sockaddr *)&ns->address));
+	  /* ???? Do more? */
+	}
+}
+
+/* a callback function. Called by libevent when the kernel says that */
+/* a nameserver socket is ready for writing or reading */
+static void
+nameserver_ready_callback(int fd, short events, void *arg) {
+	struct nameserver *ns = (struct nameserver *) arg;
+	(void)fd;
+
+	if (events & EV_WRITE) {
+		ns->choked = 0;
+		if (!evdns_transmit(ns->base)) {
+			nameserver_write_waiting(ns, 0);
+		}
+	}
+	if (events & EV_READ) {
+		nameserver_read(ns);
+	}
+}
+
+/* a callback function. Called by libevent when the kernel says that */
+/* a server socket is ready for writing or reading. */
+static void
+server_port_ready_callback(int fd, short events, void *arg) {
+	struct evdns_server_port *port = (struct evdns_server_port *) arg;
+	(void) fd;
+
+	if (events & EV_WRITE) {
+		port->choked = 0;
+		server_port_flush(port);
+	}
+	if (events & EV_READ) {
+		server_port_read(port);
+	}
+}
+
+/* This is an inefficient representation; only use it via the dnslabel_table_*
+ * functions, so that is can be safely replaced with something smarter later. */
+#define MAX_LABELS 128
+/* Structures used to implement name compression */
+struct dnslabel_entry { char *v; off_t pos; };
+struct dnslabel_table {
+	int n_labels; /* number of current entries */
+	/* map from name to position in message */
+	struct dnslabel_entry labels[MAX_LABELS];
+};
+
+/* Initialize dnslabel_table. */
+static void
+dnslabel_table_init(struct dnslabel_table *table)
+{
+	table->n_labels = 0;
+}
+
+/* Free all storage held by table, but not the table itself. */
+static void
+dnslabel_clear(struct dnslabel_table *table)
+{
+	int i;
+	for (i = 0; i < table->n_labels; ++i)
+		g_free(table->labels[i].v);
+	table->n_labels = 0;
+}
+
+/* return the position of the label in the current message, or -1 if the label */
+/* hasn't been used yet. */
+static int
+dnslabel_table_get_pos(const struct dnslabel_table *table, const char *label)
+{
+	int i;
+	for (i = 0; i < table->n_labels; ++i) {
+		if (!strcmp(label, table->labels[i].v))
+			return table->labels[i].pos;
+	}
+	return -1;
+}
+
+/* remember that we've used the label at position pos */
+static int
+dnslabel_table_add(struct dnslabel_table *table, const char *label, off_t pos)
+{
+	char *v;
+	int p;
+	if (table->n_labels == MAX_LABELS)
+		return (-1);
+	v = g_strdup(label);
+	if (v == NULL)
+		return (-1);
+	p = table->n_labels++;
+	table->labels[p].v = v;
+	table->labels[p].pos = pos;
+
+	return (0);
+}
+
+/* Converts a string to a length-prefixed set of DNS labels, starting */
+/* at buf[j]. name and buf must not overlap. name_len should be the length */
+/* of name.	 table is optional, and is used for compression. */
+/* */
+/* Input: abc.def */
+/* Output: <3>abc<3>def<0> */
+/* */
+/* Returns the first index after the encoded name, or negative on error. */
+/*	 -1	 label was > 63 bytes */
+/*	 -2	 name too long to fit in buffer. */
+/* */
+static off_t
+dnsname_to_labels(u8 *const buf, size_t buf_len, off_t j,
+				  const char *name, const int name_len,
+				  struct dnslabel_table *table) {
+	const char *end = name + name_len;
+	int ref = 0;
+	u16 _t;
+
+#define APPEND16(x) do {						\
+		if (j + 2 > (off_t)buf_len)				\
+			goto overflow;					\
+		_t = htons(x);						\
+		memcpy(buf + j, &_t, 2);				\
+		j += 2;							\
+	} while (0)
+#define APPEND32(x) do {						\
+		if (j + 4 > (off_t)buf_len)				\
+			goto overflow;					\
+		_t32 = htonl(x);					\
+		memcpy(buf + j, &_t32, 4);				\
+		j += 4;							\
+	} while (0)
+
+	if (name_len > 255) return -2;
+
+	for (;;) {
+		const char *const start = name;
+		if (table && (ref = dnslabel_table_get_pos(table, name)) >= 0) {
+			APPEND16(ref | 0xc000);
+			return j;
+		}
+		name = strchr(name, '.');
+		if (!name) {
+			const unsigned int label_len = end - start;
+			if (label_len > 63) return -1;
+			if ((size_t)(j+label_len+1) > buf_len) return -2;
+			if (table) dnslabel_table_add(table, start, j);
+			buf[j++] = label_len;
+
+			memcpy(buf + j, start, end - start);
+			j += end - start;
+			break;
+		} else {
+			/* append length of the label. */
+			const unsigned int label_len = name - start;
+			if (label_len > 63) return -1;
+			if ((size_t)(j+label_len+1) > buf_len) return -2;
+			if (table) dnslabel_table_add(table, start, j);
+			buf[j++] = label_len;
+
+			memcpy(buf + j, start, name - start);
+			j += name - start;
+			/* hop over the '.' */
+			name++;
+		}
+	}
+
+	/* the labels must be terminated by a 0. */
+	/* It's possible that the name ended in a . */
+	/* in which case the zero is already there */
+	if (!j || buf[j-1]) buf[j++] = 0;
+	return j;
+ overflow:
+	return (-2);
+}
+
+/* Finds the length of a dns request for a DNS name of the given */
+/* length. The actual request may be smaller than the value returned */
+/* here */
+static size_t
+evdns_request_len(const size_t name_len) {
+	return 96 + /* length of the DNS standard header */
+		name_len + 2 +
+		4;  /* space for the resource type */
+}
+
+/* build a dns request packet into buf. buf should be at least as long */
+/* as evdns_request_len told you it should be. */
+/* */
+/* Returns the amount of space used. Negative on error. */
+static int
+evdns_request_data_build(const char *const name, const int name_len,
+    const u16 trans_id, const u16 type, const u16 class,
+    u8 *const buf, size_t buf_len) {
+	off_t j = 0;  /* current offset into buf */
+	u16 _t;	 /* used by the macros */
+
+	APPEND16(trans_id);
+	APPEND16(0x0100);  /* standard query, recusion needed */
+	APPEND16(1);  /* one question */
+	APPEND16(0);  /* no answers */
+	APPEND16(0);  /* no authority */
+	APPEND16(0);  /* no additional */
+
+	j = dnsname_to_labels(buf, buf_len, j, name, name_len, NULL);
+	if (j < 0) {
+		return (int)j;
+	}
+
+	APPEND16(type);
+	APPEND16(class);
+
+	return (int)j;
+ overflow:
+	return (-1);
+}
+
+/* exported function */
+struct evdns_server_port *
+evdns_add_server_port_with_base(struct event_base *base, int socket, int is_tcp, evdns_request_callback_fn_type cb, void *user_data)
+{
+	struct evdns_server_port *port;
+	if (!(port = g_malloc(sizeof(struct evdns_server_port))))
+		return NULL;
+	memset(port, 0, sizeof(struct evdns_server_port));
+
+	g_assert(!is_tcp); /* TCP sockets not yet implemented */
+	port->socket = socket;
+	port->refcnt = 1;
+	port->choked = 0;
+	port->closing = 0;
+	port->user_callback = cb;
+	port->user_data = user_data;
+	port->pending_replies = NULL;
+	port->event_base = base;
+
+	event_assign(&port->event, port->event_base,
+				 port->socket, EV_READ | EV_PERSIST,
+				 server_port_ready_callback, port);
+	if (event_add(&port->event, NULL) < 0) {
+		g_free(port);
+		return NULL;
+	}
+	return port;
+}
+
+struct evdns_server_port *
+evdns_add_server_port(int socket, int is_tcp, evdns_request_callback_fn_type cb, void *user_data)
+{
+	return evdns_add_server_port_with_base(NULL, socket, is_tcp, cb, user_data);
+}
+
+/* exported function */
+void
+evdns_close_server_port(struct evdns_server_port *port)
+{
+	if (--port->refcnt == 0) {
+		server_port_free(port);
+	} else {
+		port->closing = 1;
+	}
+}
+
+/* exported function */
+int
+evdns_server_request_add_reply(struct evdns_server_request *_req, int section, const char *name, int type, int class, int ttl, int datalen, int is_name, const char *data)
+{
+	struct server_request *req = TO_SERVER_REQUEST(_req);
+	struct server_reply_item **itemp, *item;
+	int *countp;
+	int result = -1;
+
+	if (req->response) /* have we already answered? */
+		goto done;
+
+	switch (section) {
+	case EVDNS_ANSWER_SECTION:
+		itemp = &req->answer;
+		countp = &req->n_answer;
+		break;
+	case EVDNS_AUTHORITY_SECTION:
+		itemp = &req->authority;
+		countp = &req->n_authority;
+		break;
+	case EVDNS_ADDITIONAL_SECTION:
+		itemp = &req->additional;
+		countp = &req->n_additional;
+		break;
+	default:
+		goto done;
+	}
+	while (*itemp) {
+		itemp = &((*itemp)->next);
+	}
+	item = g_malloc(sizeof(struct server_reply_item));
+	if (!item)
+		goto done;
+	item->next = NULL;
+	if (!(item->name = g_strdup(name))) {
+		g_free(item);
+		goto done;
+	}
+	item->type = type;
+	item->dns_question_class = class;
+	item->ttl = ttl;
+	item->is_name = is_name != 0;
+	item->datalen = 0;
+	item->data = NULL;
+	if (data) {
+		if (item->is_name) {
+			if (!(item->data = g_strdup(data))) {
+				g_free(item->name);
+				g_free(item);
+				goto done;
+			}
+			item->datalen = (u16)-1;
+		} else {
+			if (!(item->data = g_malloc(datalen))) {
+				g_free(item->name);
+				g_free(item);
+				goto done;
+			}
+			item->datalen = datalen;
+			memcpy(item->data, data, datalen);
+		}
+	}
+
+	*itemp = item;
+	++(*countp);
+	result = 0;
+done:
+	return result;
+}
+
+/* exported function */
+int
+evdns_server_request_add_a_reply(struct evdns_server_request *req, const char *name, int n, void *addrs, int ttl)
+{
+	return evdns_server_request_add_reply(
+		  req, EVDNS_ANSWER_SECTION, name, TYPE_A, CLASS_INET,
+		  ttl, n*4, 0, addrs);
+}
+
+/* exported function */
+int
+evdns_server_request_add_aaaa_reply(struct evdns_server_request *req, const char *name, int n, void *addrs, int ttl)
+{
+	return evdns_server_request_add_reply(
+		  req, EVDNS_ANSWER_SECTION, name, TYPE_AAAA, CLASS_INET,
+		  ttl, n*16, 0, addrs);
+}
+
+/* exported function */
+int
+evdns_server_request_add_ptr_reply(struct evdns_server_request *req, struct in_addr *in, const char *inaddr_name, const char *hostname, int ttl)
+{
+	u32 a;
+	char buf[32];
+	g_assert(in || inaddr_name);
+	g_assert(!(in && inaddr_name));
+	if (in) {
+		a = ntohl(in->s_addr);
+		snprintf(buf, sizeof(buf), "%d.%d.%d.%d.in-addr.arpa",
+				(int)(u8)((a	)&0xff),
+				(int)(u8)((a>>8 )&0xff),
+				(int)(u8)((a>>16)&0xff),
+				(int)(u8)((a>>24)&0xff));
+		inaddr_name = buf;
+	}
+	return evdns_server_request_add_reply(
+		  req, EVDNS_ANSWER_SECTION, inaddr_name, TYPE_PTR, CLASS_INET,
+		  ttl, -1, 1, hostname);
+}
+
+/* exported function */
+int
+evdns_server_request_add_cname_reply(struct evdns_server_request *req, const char *name, const char *cname, int ttl)
+{
+	return evdns_server_request_add_reply(
+		  req, EVDNS_ANSWER_SECTION, name, TYPE_CNAME, CLASS_INET,
+		  ttl, -1, 1, cname);
+}
+
+/* exported function */
+void
+evdns_server_request_set_flags(struct evdns_server_request *exreq, int flags)
+{
+	struct server_request *req = TO_SERVER_REQUEST(exreq);
+	req->base.flags &= ~(EVDNS_FLAGS_AA|EVDNS_FLAGS_RD);
+	req->base.flags |= flags;
+}
+
+static int
+evdns_server_request_format_response(struct server_request *req, int err)
+{
+	unsigned char buf[1500];
+	size_t buf_len = sizeof(buf);
+	off_t j = 0, r;
+	u16 _t;
+	u32 _t32;
+	int i;
+	u16 flags;
+	struct dnslabel_table table;
+
+	if (err < 0 || err > 15) return -1;
+
+	/* Set response bit and error code; copy OPCODE and RD fields from
+	 * question; copy RA and AA if set by caller. */
+	flags = req->base.flags;
+	flags |= (0x8000 | err);
+
+	dnslabel_table_init(&table);
+	APPEND16(req->trans_id);
+	APPEND16(flags);
+	APPEND16(req->base.nquestions);
+	APPEND16(req->n_answer);
+	APPEND16(req->n_authority);
+	APPEND16(req->n_additional);
+
+	/* Add questions. */
+	for (i=0; i < req->base.nquestions; ++i) {
+		const char *s = req->base.questions[i]->name;
+		j = dnsname_to_labels(buf, buf_len, j, s, strlen(s), &table);
+		if (j < 0) {
+			dnslabel_clear(&table);
+			return (int) j;
+		}
+		APPEND16(req->base.questions[i]->type);
+		APPEND16(req->base.questions[i]->dns_question_class);
+	}
+
+	/* Add answer, authority, and additional sections. */
+	for (i=0; i<3; ++i) {
+		struct server_reply_item *item;
+		if (i==0)
+			item = req->answer;
+		else if (i==1)
+			item = req->authority;
+		else
+			item = req->additional;
+		while (item) {
+			r = dnsname_to_labels(buf, buf_len, j, item->name, strlen(item->name), &table);
+			if (r < 0)
+				goto overflow;
+			j = r;
+
+			APPEND16(item->type);
+			APPEND16(item->dns_question_class);
+			APPEND32(item->ttl);
+			if (item->is_name) {
+				off_t len_idx = j, name_start;
+				j += 2;
+				name_start = j;
+				r = dnsname_to_labels(buf, buf_len, j, item->data, strlen(item->data), &table);
+				if (r < 0)
+					goto overflow;
+				j = r;
+				_t = htons( (short) (j-name_start) );
+				memcpy(buf+len_idx, &_t, 2);
+			} else {
+				APPEND16(item->datalen);
+				if (j+item->datalen > (off_t)buf_len)
+					goto overflow;
+				memcpy(buf+j, item->data, item->datalen);
+				j += item->datalen;
+			}
+			item = item->next;
+		}
+	}
+
+	if (j > 512) {
+overflow:
+		j = 512;
+		buf[2] |= 0x02; /* set the truncated bit. */
+	}
+
+	req->response_len = j;
+
+	if (!(req->response = g_malloc(req->response_len))) {
+		server_request_free_answers(req);
+		dnslabel_clear(&table);
+		return (-1);
+	}
+	memcpy(req->response, buf, req->response_len);
+	server_request_free_answers(req);
+	dnslabel_clear(&table);
+	return (0);
+}
+
+/* exported function */
+int
+evdns_server_request_respond(struct evdns_server_request *_req, int err)
+{
+	struct server_request *req = TO_SERVER_REQUEST(_req);
+	struct evdns_server_port *port = req->port;
+	int r = -1;
+
+	if (!req->response) {
+		if ((r = evdns_server_request_format_response(req, err))<0)
+			goto done;
+	}
+
+	r = sendto(port->socket, req->response, req->response_len, 0,
+			   (struct sockaddr*) &req->addr, req->addrlen);
+	if (r<0) {
+		if (port->pending_replies) {
+			req->prev_pending = port->pending_replies->prev_pending;
+			req->next_pending = port->pending_replies;
+			req->prev_pending->next_pending =
+				req->next_pending->prev_pending = req;
+		} else {
+			req->prev_pending = req->next_pending = req;
+			port->pending_replies = req;
+			port->choked = 1;
+
+			(void) event_del(&port->event);
+			event_assign(&port->event, port->event_base, port->socket, (port->closing?0:EV_READ) | EV_WRITE | EV_PERSIST, server_port_ready_callback, port);
+
+			if (event_add(&port->event, NULL) < 0) {
+				msg_warn("Error from libevent when adding event for DNS server");
+			}
+
+		}
+
+		r = 1;
+		goto done;
+	}
+	if (server_request_free(req)) {
+		r = 0;
+		goto done;
+	}
+
+	if (port->pending_replies)
+		server_port_flush(port);
+
+	r = 0;
+done:
+	return r;
+}
+
+/* Free all storage held by RRs in req. */
+static void
+server_request_free_answers(struct server_request *req)
+{
+	struct server_reply_item *victim, *next, **list;
+	int i;
+	for (i = 0; i < 3; ++i) {
+		if (i==0)
+			list = &req->answer;
+		else if (i==1)
+			list = &req->authority;
+		else
+			list = &req->additional;
+
+		victim = *list;
+		while (victim) {
+			next = victim->next;
+			g_free(victim->name);
+			if (victim->data)
+				g_free(victim->data);
+			g_free(victim);
+			victim = next;
+		}
+		*list = NULL;
+	}
+}
+
+/* Free all storage held by req, and remove links to it. */
+/* return true iff we just wound up freeing the server_port. */
+static int
+server_request_free(struct server_request *req)
+{
+	int i, rc=1, lock=0;
+	if (req->base.questions) {
+		for (i = 0; i < req->base.nquestions; ++i)
+			g_free(req->base.questions[i]);
+		g_free(req->base.questions);
+	}
+
+	if (req->port) {
+		lock=1;
+		if (req->port->pending_replies == req) {
+			if (req->next_pending)
+				req->port->pending_replies = req->next_pending;
+			else
+				req->port->pending_replies = NULL;
+		}
+		rc = --req->port->refcnt;
+	}
+
+	if (req->response) {
+		g_free(req->response);
+	}
+
+	server_request_free_answers(req);
+
+	if (req->next_pending && req->next_pending != req) {
+		req->next_pending->prev_pending = req->prev_pending;
+		req->prev_pending->next_pending = req->next_pending;
+	}
+
+	if (rc == 0) {
+		server_port_free(req->port);
+		g_free(req);
+		return (1);
+	}
+	g_free(req);
+	return (0);
+}
+
+/* Free all storage held by an evdns_server_port.  Only called when  */
+static void
+server_port_free(struct evdns_server_port *port)
+{
+	g_assert(port);
+	g_assert(!port->refcnt);
+	g_assert(!port->pending_replies);
+	if (port->socket > 0) {
+		CLOSE_SOCKET(port->socket);
+		port->socket = -1;
+	}
+	(void) event_del(&port->event);
+	g_free(port);
+}
+
+/* exported function */
+int
+evdns_server_request_drop(struct evdns_server_request *_req)
+{
+	struct server_request *req = TO_SERVER_REQUEST(_req);
+	server_request_free(req);
+	return 0;
+}
+
+/* exported function */
+int
+evdns_server_request_get_requesting_addr(struct evdns_server_request *_req, struct sockaddr *sa, int addr_len)
+{
+	struct server_request *req = TO_SERVER_REQUEST(_req);
+	if (addr_len < (int)req->addrlen)
+		return -1;
+	memcpy(sa, &(req->addr), req->addrlen);
+	return req->addrlen;
+}
+
+#undef APPEND16
+#undef APPEND32
+
+/* this is a libevent callback function which is called when a request */
+/* has timed out. */
+static void
+evdns_request_timeout_callback(int fd, short events, void *arg) {
+	struct evdns_request *const req = (struct evdns_request *) arg;
+	(void) fd;
+	(void) events;
+
+
+	req->ns->timedout++;
+	if (req->ns->timedout > req->base->global_max_nameserver_timeout) {
+		req->ns->timedout = 0;
+		nameserver_failed(req->ns, "request timed out.");
+	}
+
+	if (req->tx_count >= req->base->global_max_retransmits) {
+		/* this request has failed */
+		reply_callback(req, 0, DNS_ERR_TIMEOUT, NULL);
+		request_finished(req, &REQ_HEAD(req->base, req->trans_id));
+	} else {
+		/* retransmit it */
+		(void) evtimer_del(&req->timeout_event);
+		evdns_request_transmit(req);
+	}
+}
+
+/* try to send a request to a given server. */
+/* */
+/* return: */
+/*   0 ok */
+/*   1 temporary failure */
+/*   2 other failure */
+static int
+evdns_request_transmit_to(struct evdns_request *req, struct nameserver *server) {
+	int r;
+	r = sendto(server->socket, req->request, req->request_len, 0,
+                (struct sockaddr *)&server->address, server->addrlen);
+	if (r < 0) {
+		int err = evutil_socket_geterror(server->socket);
+		nameserver_failed(req->ns, evutil_socket_error_to_string(err));
+		return 2;
+	} else if (r != (int)req->request_len) {
+		return 1;  /* short write */
+	} else {
+		return 0;
+	}
+}
+
+/* try to send a request, updating the fields of the request */
+/* as needed */
+/* */
+/* return: */
+/*   0 ok */
+/*   1 failed */
+static int
+evdns_request_transmit(struct evdns_request *req) {
+	int retcode = 0, r;
+
+	/* if we fail to send this packet then this flag marks it */
+	/* for evdns_transmit */
+	req->transmit_me = 1;
+	if (req->trans_id == 0xffff) abort();
+
+	if (req->ns->choked) {
+		/* don't bother trying to write to a socket */
+		/* which we have had EAGAIN from */
+		return 1;
+	}
+
+	r = evdns_request_transmit_to(req, req->ns);
+	switch (r) {
+	case 1:
+		/* temp failure */
+		req->ns->choked = 1;
+		nameserver_write_waiting(req->ns, 1);
+		return 1;
+	case 2:
+		/* failed to transmit the request entirely. */
+		retcode = 1;
+		/* fall through: we'll set a timeout, which will time out,
+		 * and make us retransmit the request anyway. */
+	default:
+		/* all ok */
+		if (evtimer_add(&req->timeout_event, &req->base->global_timeout) < 0) {
+			msg_warn(
+		      "Error from libevent when adding timer for request %lx",
+				(unsigned long) req);
+			/* ???? Do more? */
+		}
+		req->tx_count++;
+		req->transmit_me = 0;
+		return retcode;
+	}
+}
+
+static void
+nameserver_probe_callback(int result, char type, int count, int ttl, void *addresses, void *arg) {
+	struct nameserver *const ns = (struct nameserver *) arg;
+	(void) type;
+	(void) count;
+	(void) ttl;
+	(void) addresses;
+
+	ns->probe_request = NULL;
+	if (result == DNS_ERR_CANCEL) {
+		/* We canceled this request because the nameserver came up
+		 * for some other reason.  Do not change our opinion about
+		 * the nameserver. */
+	} else if (result == DNS_ERR_NONE || result == DNS_ERR_NOTEXIST) {
+		/* this is a good reply */
+		nameserver_up(ns);
+	} else {
+		nameserver_probe_failed(ns);
+	}
+}
+
+static void
+nameserver_send_probe(struct nameserver *const ns) {
+	struct evdns_request *req;
+	/* here we need to send a probe to a given nameserver */
+	/* in the hope that it is up now. */
+
+
+	req = request_new(ns->base, TYPE_A, "google.com", DNS_QUERY_NO_SEARCH, nameserver_probe_callback, ns);
+	if (!req) return;
+	ns->probe_request = req;
+	/* we force this into the inflight queue no matter what */
+	request_trans_id_set(req, transaction_id_pick(ns->base));
+	req->ns = ns;
+	request_submit(req);
+}
+
+/* returns: */
+/*   0 didn't try to transmit anything */
+/*   1 tried to transmit something */
+static int
+evdns_transmit(struct evdns_base *base) {
+	char did_try_to_transmit = 0;
+	int i;
+
+	for (i = 0; i < base->n_req_heads; ++i) {
+		if (base->req_heads[i]) {
+			struct evdns_request *const started_at = base->req_heads[i], *req = started_at;
+			/* first transmit all the requests which are currently waiting */
+			do {
+				if (req->transmit_me) {
+					did_try_to_transmit = 1;
+					evdns_request_transmit(req);
+				}
+
+				req = req->next;
+			} while (req != started_at);
+		}
+	}
+
+	return did_try_to_transmit;
+}
+
+/* exported function */
+int
+evdns_base_count_nameservers(struct evdns_base *base)
+{
+	const struct nameserver *server;
+	int n = 0;
+
+	server = base->server_head;
+	if (!server)
+		goto done;
+	do {
+		++n;
+		server = server->next;
+	} while (server != base->server_head);
+done:
+	return n;
+}
+
+int
+evdns_count_nameservers(void)
+{
+	return evdns_base_count_nameservers(current_base);
+}
+
+/* exported function */
+int
+evdns_base_clear_nameservers_and_suspend(struct evdns_base *base)
+{
+	struct nameserver *server, *started_at;
+	int i;
+
+	server = base->server_head;
+	started_at = base->server_head;
+	if (!server) {
+		return 0;
+	}
+	while (1) {
+		struct nameserver *next = server->next;
+		(void) event_del(&server->event);
+		if (evtimer_initialized(&server->timeout_event))
+			(void) evtimer_del(&server->timeout_event);
+		if (server->socket >= 0)
+			CLOSE_SOCKET(server->socket);
+		g_free(server);
+		if (next == started_at)
+			break;
+		server = next;
+	}
+	base->server_head = NULL;
+	base->global_good_nameservers = 0;
+
+	for (i = 0; i < base->n_req_heads; ++i) {
+		struct evdns_request *req, *req_started_at;
+		req = req_started_at = base->req_heads[i];
+		while (req) {
+			struct evdns_request *next = req->next;
+			req->tx_count = req->reissue_count = 0;
+			req->ns = NULL;
+			/* ???? What to do about searches? */
+			(void) evtimer_del(&req->timeout_event);
+			req->trans_id = 0;
+			req->transmit_me = 0;
+
+			base->global_requests_waiting++;
+			evdns_request_insert(req, &base->req_waiting_head);
+			/* We want to insert these suspended elements at the front of
+			 * the waiting queue, since they were pending before any of
+			 * the waiting entries were added.  This is a circular list,
+			 * so we can just shift the start back by one.*/
+			base->req_waiting_head = base->req_waiting_head->prev;
+
+			if (next == req_started_at)
+				break;
+			req = next;
+		}
+		base->req_heads[i] = NULL;
+	}
+
+	base->global_requests_inflight = 0;
+
+	return 0;
+}
+
+int
+evdns_clear_nameservers_and_suspend(void)
+{
+	return evdns_base_clear_nameservers_and_suspend(current_base);
+}
+
+
+/* exported function */
+int
+evdns_base_resume(struct evdns_base *base)
+{
+	evdns_requests_pump_waiting_queue(base);
+	return 0;
+}
+
+int
+evdns_resume(void)
+{
+	return evdns_base_resume(current_base);
+}
+
+static int
+_evdns_nameserver_add_impl(struct evdns_base *base, const struct sockaddr *address, int addrlen) {
+	/* first check to see if we already have this nameserver */
+
+	const struct nameserver *server = base->server_head, *const started_at = base->server_head;
+	struct nameserver *ns;
+	int err = 0;
+
+	if (server) {
+		do {
+			if (!evutil_sockaddr_cmp((struct sockaddr*)&server->address, address, 1)) return 3;
+			server = server->next;
+		} while (server != started_at);
+	}
+	if (addrlen > (int)sizeof(ns->address)) {
+		return 2;
+	}
+
+	ns = (struct nameserver *) g_malloc(sizeof(struct nameserver));
+	if (!ns) return -1;
+
+	memset(ns, 0, sizeof(struct nameserver));
+	ns->base = base;
+
+	evtimer_assign(&ns->timeout_event, ns->base->event_base, nameserver_prod_callback, ns);
+
+	ns->socket = socket(PF_INET, SOCK_DGRAM, 0);
+	if (ns->socket < 0) { err = 1; goto out1; }
+	make_socket_nonblocking(ns->socket);
+
+	if (base->global_outgoing_addrlen) {
+		if (bind(ns->socket,
+			(struct sockaddr*)&base->global_outgoing_address,
+			base->global_outgoing_addrlen) < 0) {
+			msg_warn("Couldn't bind to outgoing address");
+			err = 2;
+			goto out2;
+		}
+	}
+
+	memcpy(&ns->address, address, addrlen);
+	ns->addrlen = addrlen;
+	ns->state = 1;
+	event_assign(&ns->event, ns->base->event_base, ns->socket, EV_READ | EV_PERSIST, nameserver_ready_callback, ns);
+	if (event_add(&ns->event, NULL) < 0) {
+		err = 2;
+		goto out2;
+	}
+
+
+	/* insert this nameserver into the list of them */
+	if (!base->server_head) {
+		ns->next = ns->prev = ns;
+		base->server_head = ns;
+	} else {
+		ns->next = base->server_head->next;
+		ns->prev = base->server_head;
+		base->server_head->next = ns;
+		if (base->server_head->prev == base->server_head) {
+			base->server_head->prev = ns;
+		}
+	}
+
+	base->global_good_nameservers++;
+
+	return 0;
+
+out2:
+	CLOSE_SOCKET(ns->socket);
+out1:
+	g_free(ns);
+	msg_warn("Unable to add nameserver %s: error %d", debug_ntop(address), err);
+	return err;
+}
+
+/* exported function */
+int
+evdns_base_nameserver_add(struct evdns_base *base,
+						  unsigned long int address)
+{
+	struct sockaddr_in sin;
+	int res;
+	sin.sin_addr.s_addr = address;
+	sin.sin_port = htons(53);
+	sin.sin_family = AF_INET;
+	res = _evdns_nameserver_add_impl(base, (struct sockaddr*)&sin, sizeof(sin));
+	return res;
+}
+
+int
+evdns_nameserver_add(unsigned long int address) {
+	if (!current_base)
+		current_base = evdns_base_new(NULL, 0);
+	return evdns_base_nameserver_add(current_base, address);
+}
+
+/* exported function */
+int
+evdns_base_nameserver_ip_add(struct evdns_base *base, const char *ip_as_string) {
+	struct sockaddr_storage ss;
+	struct sockaddr *sa;
+	int len = sizeof(ss);
+	int res;
+	if (evutil_parse_sockaddr_port(ip_as_string, (struct sockaddr *)&ss,
+		&len)) {
+		msg_warn("Unable to parse nameserver address %s",
+			ip_as_string);
+		return 4;
+	}
+	sa = (struct sockaddr *) &ss;
+	if (sa->sa_family == AF_INET) {
+		struct sockaddr_in *sin = (struct sockaddr_in *)sa;
+		if (sin->sin_port == 0)
+			sin->sin_port = htons(53);
+	}
+#ifdef AF_INET6
+	else if (sa->sa_family == AF_INET6) {
+		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
+		if (sin6->sin6_port == 0)
+			sin6->sin6_port = htons(53);
+	}
+#endif
+	else
+		return -1;
+
+	res = _evdns_nameserver_add_impl(base, sa, len);
+	return res;
+}
+
+int
+evdns_nameserver_ip_add(const char *ip_as_string) {
+	if (!current_base)
+		current_base = evdns_base_new(NULL, 0);
+	return evdns_base_nameserver_ip_add(current_base, ip_as_string);
+}
+
+/* remove from the queue */
+static void
+evdns_request_remove(struct evdns_request *req, struct evdns_request **head)
+{
+
+#if 0
+	{
+		struct evdns_request *ptr;
+		int found = 0;
+		g_assert(*head != NULL);
+
+		ptr = *head;
+		do {
+			if (ptr == req) {
+				found = 1;
+				break;
+			}
+			ptr = ptr->next;
+		} while (ptr != *head);
+		g_assert(found);
+
+		g_assert(req->next);
+	}
+#endif
+
+	if (req->next == req) {
+		/* only item in the list */
+		*head = NULL;
+	} else {
+		req->next->prev = req->prev;
+		req->prev->next = req->next;
+		if (*head == req) *head = req->next;
+	}
+	req->next = req->prev = NULL;
+}
+
+/* insert into the tail of the queue */
+static void
+evdns_request_insert(struct evdns_request *req, struct evdns_request **head) {
+	if (!*head) {
+		*head = req;
+		req->next = req->prev = req;
+		return;
+	}
+
+	req->prev = (*head)->prev;
+	req->prev->next = req;
+	req->next = *head;
+	(*head)->prev = req;
+}
+
+static int
+string_num_dots(const char *s) {
+	int count = 0;
+	while ((s = strchr(s, '.'))) {
+		s++;
+		count++;
+	}
+	return count;
+}
+
+static struct evdns_request *
+request_new(struct evdns_base *base, int type, const char *name, int flags,
+    evdns_callback_type callback, void *user_ptr) {
+
+	const char issuing_now =
+	    (base->global_requests_inflight < base->global_max_requests_inflight) ? 1 : 0;
+
+	const size_t name_len = strlen(name);
+	const size_t request_max_len = evdns_request_len(name_len);
+	const u16 trans_id = issuing_now ? transaction_id_pick(base) : 0xffff;
+	/* the request data is alloced in a single block with the header */
+	struct evdns_request *const req =
+	    g_malloc(sizeof(struct evdns_request) + request_max_len);
+	int rlen;
+	char namebuf[256];
+	(void) flags;
+
+
+	if (!req) return NULL;
+
+	if (name_len >= sizeof(namebuf)) {
+		free(req);
+		return NULL;
+	}
+
+	memset(req, 0, sizeof(struct evdns_request));
+	req->base = base;
+
+	evtimer_assign(&req->timeout_event, req->base->event_base, evdns_request_timeout_callback, req);
+
+	if (base->global_randomize_case) {
+		unsigned i;
+		char randbits[(sizeof(namebuf)+7)/8];
+		g_strlcpy(namebuf, name, sizeof(namebuf));
+		rand_bytes_function(randbits, (name_len+7)/8);
+		for (i = 0; i < name_len; ++i) {
+			if (g_ascii_isalpha(namebuf[i])) {
+				if ((randbits[i >> 3] & (1<<(i & 7))))
+					namebuf[i] |= 0x20;
+				else
+					namebuf[i] &= ~0x20;
+			}
+		}
+		name = namebuf;
+	}
+
+	/* request data lives just after the header */
+	req->request = ((u8 *) req) + sizeof(struct evdns_request);
+	/* denotes that the request data shouldn't be free()ed */
+	req->request_appended = 1;
+	rlen = evdns_request_data_build(name, name_len, trans_id,
+	    type, CLASS_INET, req->request, request_max_len);
+	if (rlen < 0)
+		goto err1;
+
+	req->request_len = rlen;
+	req->trans_id = trans_id;
+	req->tx_count = 0;
+	req->request_type = type;
+	req->user_pointer = user_ptr;
+	req->user_callback = callback;
+	req->ns = issuing_now ? nameserver_pick(base) : NULL;
+	req->next = req->prev = NULL;
+
+	return req;
+err1:
+	g_free(req);
+	return NULL;
+}
+
+static void
+request_submit(struct evdns_request *const req) {
+	struct evdns_base *base = req->base;
+	if (req->ns) {
+		/* if it has a nameserver assigned then this is going */
+		/* straight into the inflight queue */
+		evdns_request_insert(req, &REQ_HEAD(base, req->trans_id));
+		base->global_requests_inflight++;
+		evdns_request_transmit(req);
+	} else {
+		evdns_request_insert(req, &base->req_waiting_head);
+		base->global_requests_waiting++;
+	}
+}
+
+/* exported function */
+void
+evdns_cancel_request(struct evdns_base *base, struct evdns_request *req)
+{
+	if (!base)
+		base = req->base;
+
+	reply_callback(req, 0, DNS_ERR_CANCEL, NULL);
+	if (req->ns) {
+		/* remove from inflight queue */
+		request_finished(req, &REQ_HEAD(base, req->trans_id));
+	} else {
+		/* remove from global_waiting head */
+		request_finished(req, &base->req_waiting_head);
+	}
+}
+
+/* exported function */
+struct evdns_request *
+evdns_base_resolve_ipv4(struct evdns_base *base, const char *name, int flags,
+    evdns_callback_type callback, void *ptr) {
+	struct evdns_request *req;
+	if (flags & DNS_QUERY_NO_SEARCH) {
+		req =
+			request_new(base, TYPE_A, name, flags, callback, ptr);
+		if (req)
+			request_submit(req);
+	} else {
+		req = search_request_new(base, TYPE_A, name, flags, callback, ptr);
+	}
+	return req;
+}
+
+int evdns_resolve_ipv4(const char *name, int flags,
+					   evdns_callback_type callback, void *ptr)
+{
+	return evdns_base_resolve_ipv4(current_base, name, flags, callback, ptr)
+		? 0 : -1;
+}
+
+
+/* exported function */
+struct evdns_request *
+evdns_base_resolve_ipv6(struct evdns_base *base,
+    const char *name, int flags,
+    evdns_callback_type callback, void *ptr)
+{
+	struct evdns_request *req;
+	if (flags & DNS_QUERY_NO_SEARCH) {
+		req = request_new(base, TYPE_AAAA, name, flags, callback, ptr);
+		if (req)
+			request_submit(req);
+	} else {
+		req = search_request_new(base,TYPE_AAAA, name, flags, callback, ptr);
+	}
+	return req;
+}
+
+int evdns_resolve_ipv6(const char *name, int flags,
+    evdns_callback_type callback, void *ptr) {
+	return evdns_base_resolve_ipv6(current_base, name, flags, callback, ptr)
+		? 0 : -1;
+}
+
+struct evdns_request *
+evdns_base_resolve_reverse(struct evdns_base *base, const struct in_addr *in, int flags, evdns_callback_type callback, void *ptr) {
+	char buf[32];
+	struct evdns_request *req;
+	u32 a;
+	g_assert(in);
+	a = ntohl(in->s_addr);
+	snprintf(buf, sizeof(buf), "%d.%d.%d.%d.in-addr.arpa",
+			(int)(u8)((a	)&0xff),
+			(int)(u8)((a>>8 )&0xff),
+			(int)(u8)((a>>16)&0xff),
+			(int)(u8)((a>>24)&0xff));
+	req = request_new(base, TYPE_PTR, buf, flags, callback, ptr);
+	if (req)
+		request_submit(req);
+	return (req);
+}
+
+int evdns_resolve_reverse(const struct in_addr *in, int flags, evdns_callback_type callback, void *ptr) {
+	return evdns_base_resolve_reverse(current_base, in, flags, callback, ptr)
+		? 0 : -1;
+}
+
+struct evdns_request *
+evdns_base_resolve_reverse_ipv6(struct evdns_base *base, const struct in6_addr *in, int flags, evdns_callback_type callback, void *ptr) {
+	/* 32 nybbles, 32 periods, "ip6.arpa", NUL. */
+	char buf[73];
+	char *cp;
+	struct evdns_request *req;
+	int i;
+	g_assert(in);
+	cp = buf;
+	for (i=15; i >= 0; --i) {
+		u8 byte = in->s6_addr[i];
+		*cp++ = "0123456789abcdef"[byte & 0x0f];
+		*cp++ = '.';
+		*cp++ = "0123456789abcdef"[byte >> 4];
+		*cp++ = '.';
+	}
+	g_assert(cp + strlen("ip6.arpa") < buf+sizeof(buf));
+	memcpy(cp, "ip6.arpa", strlen("ip6.arpa")+1);
+	req = request_new(base, TYPE_PTR, buf, flags, callback, ptr);
+	if (req)
+		request_submit(req);
+	return (req);
+}
+
+int evdns_resolve_reverse_ipv6(const struct in6_addr *in, int flags, evdns_callback_type callback, void *ptr) {
+	return evdns_base_resolve_reverse_ipv6(current_base, in, flags, callback, ptr)
+		? 0 : -1;
+}
+
+int
+evdns_resolve_txt(const char *in, int flags, evdns_callback_type callback, void *ptr) {
+	struct evdns_request *req;
+	g_assert(in);
+	req = request_new(current_base, TYPE_TXT, in, flags, callback, ptr);
+	if (!req) return 1;
+	request_submit(req);
+	return 0;
+}
+
+
+/*/////////////////////////////////////////////////////////////////// */
+/* Search support */
+/* */
+/* the libc resolver has support for searching a number of domains */
+/* to find a name. If nothing else then it takes the single domain */
+/* from the gethostname() call. */
+/* */
+/* It can also be configured via the domain and search options in a */
+/* resolv.conf. */
+/* */
+/* The ndots option controls how many dots it takes for the resolver */
+/* to decide that a name is non-local and so try a raw lookup first. */
+
+struct search_domain {
+	int len;
+	struct search_domain *next;
+	/* the text string is appended to this structure */
+};
+
+struct search_state {
+	int refcount;
+	int ndots;
+	int num_domains;
+	struct search_domain *head;
+};
+
+static void
+search_state_decref(struct search_state *const state) {
+	if (!state) return;
+	state->refcount--;
+	if (!state->refcount) {
+		struct search_domain *next, *dom;
+		for (dom = state->head; dom; dom = next) {
+			next = dom->next;
+			g_free(dom);
+		}
+		g_free(state);
+	}
+}
+
+static struct search_state *
+search_state_new(void) {
+	struct search_state *state = (struct search_state *) g_malloc(sizeof(struct search_state));
+	if (!state) return NULL;
+	memset(state, 0, sizeof(struct search_state));
+	state->refcount = 1;
+	state->ndots = 1;
+
+	return state;
+}
+
+static void
+search_postfix_clear(struct evdns_base *base) {
+	search_state_decref(base->global_search_state);
+
+	base->global_search_state = search_state_new();
+}
+
+/* exported function */
+void
+evdns_base_search_clear(struct evdns_base *base)
+{
+	search_postfix_clear(base);
+}
+
+void
+evdns_search_clear(void) {
+	evdns_base_search_clear(current_base);
+}
+
+static void
+search_postfix_add(struct evdns_base *base, const char *domain) {
+	int domain_len;
+	struct search_domain *sdomain;
+	while (domain[0] == '.') domain++;
+	domain_len = strlen(domain);
+
+	if (!base->global_search_state) base->global_search_state = search_state_new();
+	if (!base->global_search_state) return;
+	base->global_search_state->num_domains++;
+
+	sdomain = (struct search_domain *) g_malloc(sizeof(struct search_domain) + domain_len);
+	if (!sdomain) return;
+	memcpy( ((u8 *) sdomain) + sizeof(struct search_domain), domain, domain_len);
+	sdomain->next = base->global_search_state->head;
+	sdomain->len = domain_len;
+
+	base->global_search_state->head = sdomain;
+}
+
+/* reverse the order of members in the postfix list. This is needed because, */
+/* when parsing resolv.conf we push elements in the wrong order */
+static void
+search_reverse(struct evdns_base *base) {
+	struct search_domain *cur, *prev = NULL, *next;
+	cur = base->global_search_state->head;
+	while (cur) {
+		next = cur->next;
+		cur->next = prev;
+		prev = cur;
+		cur = next;
+	}
+
+	base->global_search_state->head = prev;
+}
+
+/* exported function */
+void
+evdns_base_search_add(struct evdns_base *base, const char *domain) {
+	search_postfix_add(base, domain);
+}
+void
+evdns_search_add(const char *domain) {
+	evdns_base_search_add(current_base, domain);
+}
+
+/* exported function */
+void
+evdns_base_search_ndots_set(struct evdns_base *base, const int ndots) {
+	if (!base->global_search_state) base->global_search_state = search_state_new();
+	if (base->global_search_state)
+		base->global_search_state->ndots = ndots;
+}
+void
+evdns_search_ndots_set(const int ndots) {
+	evdns_base_search_ndots_set(current_base, ndots);
+}
+
+static void
+search_set_from_hostname(struct evdns_base *base) {
+	char hostname[HOST_NAME_MAX + 1], *domainname;
+
+	search_postfix_clear(base);
+	if (gethostname(hostname, sizeof(hostname))) return;
+	domainname = strchr(hostname, '.');
+	if (!domainname) return;
+	search_postfix_add(base, domainname);
+}
+
+/* warning: returns malloced string */
+static char *
+search_make_new(const struct search_state *const state, int n, const char *const base_name) {
+	const int base_len = strlen(base_name);
+	const char need_to_append_dot = base_name[base_len - 1] == '.' ? 0 : 1;
+	struct search_domain *dom;
+
+	for (dom = state->head; dom; dom = dom->next) {
+		if (!n--) {
+			/* this is the postfix we want */
+			/* the actual postfix string is kept at the end of the structure */
+			const u8 *const postfix = ((u8 *) dom) + sizeof(struct search_domain);
+			const int postfix_len = dom->len;
+			char *const newname = (char *) g_malloc(base_len + need_to_append_dot + postfix_len + 1);
+			if (!newname) return NULL;
+			memcpy(newname, base_name, base_len);
+			if (need_to_append_dot) newname[base_len] = '.';
+			memcpy(newname + base_len + need_to_append_dot, postfix, postfix_len);
+			newname[base_len + need_to_append_dot + postfix_len] = 0;
+			return newname;
+		}
+	}
+
+	/* we ran off the end of the list and still didn't find the requested string */
+	abort();
+	return NULL; /* unreachable; stops warnings in some compilers. */
+}
+
+static struct evdns_request *
+search_request_new(struct evdns_base *base, int type, const char *const name, int flags, evdns_callback_type user_callback, void *user_arg) {
+	g_assert(type == TYPE_A || type == TYPE_AAAA);
+	if ( ((flags & DNS_QUERY_NO_SEARCH) == 0) &&
+	     base->global_search_state &&
+		 base->global_search_state->num_domains) {
+		/* we have some domains to search */
+		struct evdns_request *req;
+		if (string_num_dots(name) >= base->global_search_state->ndots) {
+			req = request_new(base, type, name, flags, user_callback, user_arg);
+			if (!req) return NULL;
+			req->search_index = -1;
+		} else {
+			char *const new_name = search_make_new(base->global_search_state, 0, name);
+			if (!new_name) return NULL;
+			req = request_new(base, type, new_name, flags, user_callback, user_arg);
+			g_free(new_name);
+			if (!req) return NULL;
+			req->search_index = 0;
+		}
+		req->search_origname = g_strdup(name);
+		req->search_state = base->global_search_state;
+		req->search_flags = flags;
+		base->global_search_state->refcount++;
+		request_submit(req);
+		return req;
+	} else {
+		struct evdns_request *const req = request_new(base, type, name, flags, user_callback, user_arg);
+		if (!req) return NULL;
+		request_submit(req);
+		return req;
+	}
+}
+
+/* if it is part of a search and, if so, try the next name in the list */
+/* returns: */
+/*   0 another request has been submitted */
+/*   1 no more requests needed */
+static int
+search_try_next(struct evdns_request *const req) {
+	struct evdns_base *base = req->base;
+	if (req->search_state) {
+		/* it is part of a search */
+		char *new_name;
+		struct evdns_request *newreq;
+		req->search_index++;
+		if (req->search_index >= req->search_state->num_domains) {
+			/* no more postfixes to try, however we may need to try */
+			/* this name without a postfix */
+			if (string_num_dots(req->search_origname) < req->search_state->ndots) {
+				/* yep, we need to try it raw */
+				newreq = request_new(base, req->request_type, req->search_origname, req->search_flags, req->user_callback, req->user_pointer);
+				if (newreq) {
+					request_submit(newreq);
+					return 0;
+				}
+			}
+			return 1;
+		}
+
+		new_name = search_make_new(req->search_state, req->search_index, req->search_origname);
+		if (!new_name) return 1;
+		newreq = request_new(base, req->request_type, new_name, req->search_flags, req->user_callback, req->user_pointer);
+		g_free(new_name);
+		if (!newreq) return 1;
+		newreq->search_origname = req->search_origname;
+		req->search_origname = NULL;
+		newreq->search_state = req->search_state;
+		newreq->search_flags = req->search_flags;
+		newreq->search_index = req->search_index;
+		newreq->search_state->refcount++;
+		request_submit(newreq);
+		return 0;
+	}
+	return 1;
+}
+
+static void
+search_request_finished(struct evdns_request *const req) {
+	if (req->search_state) {
+		search_state_decref(req->search_state);
+		req->search_state = NULL;
+	}
+	if (req->search_origname) {
+		g_free(req->search_origname);
+		req->search_origname = NULL;
+	}
+}
+
+/*/////////////////////////////////////////////////////////////////// */
+/* Parsing resolv.conf files */
+
+static void
+evdns_resolv_set_defaults(struct evdns_base *base, int flags) {
+	/* if the file isn't found then we assume a local resolver */
+	if (flags & DNS_OPTION_SEARCH) search_set_from_hostname(base);
+	if (flags & DNS_OPTION_NAMESERVERS) evdns_base_nameserver_ip_add(base,"127.0.0.1");
+}
+
+
+/* helper version of atoi which returns -1 on error */
+static int
+strtoint(const char *const str)
+{
+	char *endptr;
+	const int r = strtol(str, &endptr, 10);
+	if (*endptr) return -1;
+	return r;
+}
+
+/* Parse a number of seconds into a timeval; return -1 on error. */
+static int
+strtotimeval(const char *const str, struct timeval *out)
+{
+	double d;
+	char *endptr;
+	d = strtod(str, &endptr);
+	if (*endptr) return -1;
+	out->tv_sec = (int) d;
+	out->tv_usec = (int) ((d - (int) d)*1000000);
+	return 0;
+}
+
+/* helper version of atoi that returns -1 on error and clips to bounds. */
+static int
+strtoint_clipped(const char *const str, int min, int max)
+{
+	int r = strtoint(str);
+	if (r == -1)
+		return r;
+	else if (r<min)
+		return min;
+	else if (r>max)
+		return max;
+	else
+		return r;
+}
+
+static int
+evdns_base_set_max_requests_inflight(struct evdns_base *base, int maxinflight)
+{
+	int old_n_heads = base->n_req_heads, n_heads;
+	struct evdns_request **old_heads = base->req_heads, **new_heads, *req;
+	int i;
+
+	if (maxinflight < 1)
+		maxinflight = 1;
+	n_heads = (maxinflight+4) / 5;
+	g_assert(n_heads > 0);
+	new_heads = g_malloc(n_heads * sizeof(struct evdns_request*));
+	if (!new_heads)
+		return (-1);
+	for (i=0; i < n_heads; ++i)
+		new_heads[i] = NULL;
+	if (old_heads) {
+		for (i = 0; i < old_n_heads; ++i) {
+			while (old_heads[i]) {
+				req = old_heads[i];
+				evdns_request_remove(req, &old_heads[i]);
+				evdns_request_insert(req, &new_heads[req->trans_id % n_heads]);
+			}
+		}
+		g_free(old_heads);
+	}
+	base->req_heads = new_heads;
+	base->n_req_heads = n_heads;
+	base->global_max_requests_inflight = maxinflight;
+	return (0);
+}
+
+/* exported function */
+int
+evdns_base_set_option(struct evdns_base *base,
+    const char *option, const char *val, int flags)
+{
+	int res;
+	res = evdns_base_set_option_impl(base, option, val, flags);
+	return res;
+}
+
+static int
+evdns_base_set_option_impl(struct evdns_base *base,
+    const char *option, const char *val, int flags)
+{
+	if (!strncmp(option, "ndots:", 6)) {
+		const int ndots = strtoint(val);
+		if (ndots == -1) return -1;
+		if (!(flags & DNS_OPTION_SEARCH)) return 0;
+		if (!base->global_search_state) base->global_search_state = search_state_new();
+		if (!base->global_search_state) return -1;
+		base->global_search_state->ndots = ndots;
+	} else if (!strncmp(option, "timeout:", 8)) {
+		struct timeval tv;
+		if (strtotimeval(val, &tv) == -1) return -1;
+		if (!(flags & DNS_OPTION_MISC)) return 0;
+		memcpy(&base->global_timeout, &tv, sizeof(struct timeval));
+	} else if (!strncmp(option, "max-timeouts:", 12)) {
+		const int maxtimeout = strtoint_clipped(val, 1, 255);
+		if (maxtimeout == -1) return -1;
+		if (!(flags & DNS_OPTION_MISC)) return 0;
+		base->global_max_nameserver_timeout = maxtimeout;
+	} else if (!strncmp(option, "max-inflight:", 13)) {
+		const int maxinflight = strtoint_clipped(val, 1, 65000);
+		if (maxinflight == -1) return -1;
+		if (!(flags & DNS_OPTION_MISC)) return 0;
+		evdns_base_set_max_requests_inflight(base, maxinflight);
+	} else if (!strncmp(option, "attempts:", 9)) {
+		int retries = strtoint(val);
+		if (retries == -1) return -1;
+		if (retries > 255) retries = 255;
+		if (!(flags & DNS_OPTION_MISC)) return 0;
+		base->global_max_retransmits = retries;
+	} else if (!strncmp(option, "randomize-case:", 15)) {
+		int randcase = strtoint(val);
+		if (!(flags & DNS_OPTION_MISC)) return 0;
+		base->global_randomize_case = randcase;
+	} else if (!strncmp(option, "bind-to:", 8)) {
+		/* XXX This only applies to successive nameservers, not
+		 * to already-configured ones.	We might want to fix that. */
+		int len = sizeof(base->global_outgoing_address);
+		if (!(flags & DNS_OPTION_NAMESERVERS)) return 0;
+		if (evutil_parse_sockaddr_port(val,
+			(struct sockaddr*)&base->global_outgoing_address, &len))
+			return -1;
+		base->global_outgoing_addrlen = len;
+	}
+	return 0;
+}
+
+int
+evdns_set_option(const char *option, const char *val, int flags)
+{
+	return evdns_base_set_option(current_base, option, val, flags);
+}
+
+static void
+resolv_conf_parse_line(struct evdns_base *base, char *const start, int flags) {
+	char *strtok_state;
+	static const char *const delims = " \t";
+#define NEXT_TOKEN strtok_r(NULL, delims, &strtok_state)
+
+
+	char *const first_token = strtok_r(start, delims, &strtok_state);
+	if (!first_token) return;
+
+	if (!strcmp(first_token, "nameserver") && (flags & DNS_OPTION_NAMESERVERS)) {
+		const char *const nameserver = NEXT_TOKEN;
+
+		evdns_base_nameserver_ip_add(base, nameserver);
+	} else if (!strcmp(first_token, "domain") && (flags & DNS_OPTION_SEARCH)) {
+		const char *const domain = NEXT_TOKEN;
+		if (domain) {
+			search_postfix_clear(base);
+			search_postfix_add(base, domain);
+		}
+	} else if (!strcmp(first_token, "search") && (flags & DNS_OPTION_SEARCH)) {
+		const char *domain;
+		search_postfix_clear(base);
+
+		while ((domain = NEXT_TOKEN)) {
+			search_postfix_add(base, domain);
+		}
+		search_reverse(base);
+	} else if (!strcmp(first_token, "options")) {
+		const char *option;
+		while ((option = NEXT_TOKEN)) {
+			const char *val = strchr(option, ':');
+			evdns_base_set_option(base, option, val ? val+1 : "", flags);
+		}
+	}
+#undef NEXT_TOKEN
+}
+
+/* exported function */
+/* returns: */
+/*   0 no errors */
+/*   1 failed to open file */
+/*   2 failed to stat file */
+/*   3 file too large */
+/*   4 out of memory */
+/*   5 short read from file */
+int
+evdns_base_resolv_conf_parse(struct evdns_base *base, int flags, const char *const filename) {
+	int res;
+	res = evdns_base_resolv_conf_parse_impl(base, flags, filename);
+	return res;
+}
+
+static int
+evdns_base_resolv_conf_parse_impl(struct evdns_base *base, int flags, const char *const filename) {
+	struct stat st;
+	int fd, n, r;
+	u8 *resolv;
+	char *start;
+	int err = 0;
+
+
+	fd = open(filename, O_RDONLY);
+	if (fd < 0) {
+		evdns_resolv_set_defaults(base, flags);
+		return 1;
+	}
+
+	if (fstat(fd, &st)) { err = 2; goto out1; }
+	if (!st.st_size) {
+		evdns_resolv_set_defaults(base, flags);
+		err = (flags & DNS_OPTION_NAMESERVERS) ? 6 : 0;
+		goto out1;
+	}
+	if (st.st_size > 65535) { err = 3; goto out1; }	 /* no resolv.conf should be any bigger */
+
+	resolv = (u8 *) g_malloc((size_t)st.st_size + 1);
+	if (!resolv) { err = 4; goto out1; }
+
+	n = 0;
+	while ((r = read(fd, resolv+n, (size_t)st.st_size-n)) > 0) {
+		n += r;
+		if (n == st.st_size)
+			break;
+		g_assert(n < st.st_size);
+	}
+	if (r < 0) { err = 5; goto out2; }
+	resolv[n] = 0;	 /* we malloced an extra byte; this should be fine. */
+
+	start = (char *) resolv;
+	for (;;) {
+		char *const newline = strchr(start, '\n');
+		if (!newline) {
+			resolv_conf_parse_line(base, start, flags);
+			break;
+		} else {
+			*newline = 0;
+			resolv_conf_parse_line(base, start, flags);
+			start = newline + 1;
+		}
+	}
+
+	if (!base->server_head && (flags & DNS_OPTION_NAMESERVERS)) {
+		/* no nameservers were configured. */
+		evdns_base_nameserver_ip_add(base, "127.0.0.1");
+		err = 6;
+	}
+	if (flags & DNS_OPTION_SEARCH && (!base->global_search_state || base->global_search_state->num_domains == 0)) {
+		search_set_from_hostname(base);
+	}
+
+out2:
+	g_free(resolv);
+out1:
+	close(fd);
+	return err;
+}
+
+int
+evdns_resolv_conf_parse(int flags, const char *const filename) {
+	return evdns_base_resolv_conf_parse(current_base, flags, filename);
+}
+
+struct evdns_base *
+evdns_base_new(struct event_base *event_base, int initialize_nameservers)
+{
+	struct evdns_base *base;
+	base = g_malloc(sizeof(struct evdns_base));
+	if (base == NULL)
+		return (NULL);
+	memset(base, 0, sizeof(struct evdns_base));
+	base->req_waiting_head = NULL;
+
+
+	/* Set max requests inflight and allocate req_heads. */
+	base->req_heads = NULL;
+
+	evdns_base_set_max_requests_inflight(base, 64);
+
+	base->server_head = NULL;
+	base->event_base = event_base;
+	base->global_good_nameservers = base->global_requests_inflight =
+		base->global_requests_waiting = 0;
+
+	base->global_timeout.tv_sec = 5;
+	base->global_timeout.tv_usec = 0;
+	base->global_max_reissues = 1;
+	base->global_max_retransmits = 3;
+	base->global_max_nameserver_timeout = 3;
+	base->global_search_state = NULL;
+	base->global_randomize_case = 1;
+
+	if (initialize_nameservers) {
+		int r;
+		r = evdns_base_resolv_conf_parse(base, DNS_OPTIONS_ALL, "/etc/resolv.conf");
+		if (r == -1) {
+			evdns_base_free_and_unlock(base, 0);
+			return NULL;
+		}
+	}
+	return base;
+}
+
+int
+evdns_init(void)
+{
+	struct evdns_base *base = evdns_base_new(NULL, 1);
+	if (base) {
+		current_base = base;
+		return 0;
+	} else {
+		return -1;
+	}
+}
+
+const char *
+evdns_err_to_string(int err)
+{
+    switch (err) {
+	case DNS_ERR_NONE: return "no error";
+	case DNS_ERR_FORMAT: return "misformatted query";
+	case DNS_ERR_SERVERFAILED: return "server failed";
+	case DNS_ERR_NOTEXIST: return "name does not exist";
+	case DNS_ERR_NOTIMPL: return "query not implemented";
+	case DNS_ERR_REFUSED: return "refused";
+
+	case DNS_ERR_TRUNCATED: return "reply truncated or ill-formed";
+	case DNS_ERR_UNKNOWN: return "unknown";
+	case DNS_ERR_TIMEOUT: return "request timed out";
+	case DNS_ERR_SHUTDOWN: return "dns subsystem shut down";
+	case DNS_ERR_CANCEL: return "dns request canceled";
+	default: return "[Unknown error code]";
+    }
+}
+
+static void
+evdns_base_free_and_unlock(struct evdns_base *base, int fail_requests)
+{
+	struct nameserver *server, *server_next;
+	struct search_domain *dom, *dom_next;
+	int i;
+
+	/* Requires that we hold the lock. */
+
+	/* TODO(nickm) we might need to refcount here. */
+
+	for (i = 0; i < base->n_req_heads; ++i) {
+		while (base->req_heads[i]) {
+			if (fail_requests)
+				reply_callback(base->req_heads[i], 0, DNS_ERR_SHUTDOWN, NULL);
+			request_finished(base->req_heads[i], &REQ_HEAD(base, base->req_heads[i]->trans_id));
+		}
+	}
+	while (base->req_waiting_head) {
+		if (fail_requests)
+			reply_callback(base->req_waiting_head, 0, DNS_ERR_SHUTDOWN, NULL);
+		request_finished(base->req_waiting_head, &base->req_waiting_head);
+	}
+	base->global_requests_inflight = base->global_requests_waiting = 0;
+
+	for (server = base->server_head; server; server = server_next) {
+		server_next = server->next;
+		if (server->socket >= 0)
+			CLOSE_SOCKET(server->socket);
+		(void) event_del(&server->event);
+		if (server->state == 0)
+			(void) event_del(&server->timeout_event);
+		g_free(server);
+		if (server_next == base->server_head)
+			break;
+	}
+	base->server_head = NULL;
+	base->global_good_nameservers = 0;
+
+	if (base->global_search_state) {
+		for (dom = base->global_search_state->head; dom; dom = dom_next) {
+			dom_next = dom->next;
+			g_free(dom);
+		}
+		g_free(base->global_search_state);
+		base->global_search_state = NULL;
+	}
+
+	g_free(base);
+}
+
+void
+evdns_base_free(struct evdns_base *base, int fail_requests)
+{
+	evdns_base_free_and_unlock(base, fail_requests);
+}
+
+void
+evdns_shutdown(int fail_requests)
+{
+	if (current_base) {
+		struct evdns_base *b = current_base;
+		current_base = NULL;
+		evdns_base_free(b, fail_requests);
+	}
+}
diff --git a/src/evdns/evdns.h b/src/evdns/evdns.h
new file mode 100644
index 000000000..5d6df1872
--- /dev/null
+++ b/src/evdns/evdns.h
@@ -0,0 +1,758 @@
+/*
+ * Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
+ * Copyright (c) 2007-2009 Niels Provos and Nick Mathewson
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef _EVDNS_H_
+#define _EVDNS_H_
+
+#include "../config.h" 
+
+/** Error codes 0-5 are as described in RFC 1035. */
+#define DNS_ERR_NONE 0
+/** The name server was unable to interpret the query */
+#define DNS_ERR_FORMAT 1
+/** The name server was unable to process this query due to a problem with the
+ * name server */
+#define DNS_ERR_SERVERFAILED 2
+/** The domain name does not exist */
+#define DNS_ERR_NOTEXIST 3
+/** The name server does not support the requested kind of query */
+#define DNS_ERR_NOTIMPL 4
+/** The name server refuses to reform the specified operation for policy
+ * reasons */
+#define DNS_ERR_REFUSED 5
+/** The reply was truncated or ill-formatted */
+#define DNS_ERR_TRUNCATED 65
+/** An unknown error occurred */
+#define DNS_ERR_UNKNOWN 66
+/** Communication with the server timed out */
+#define DNS_ERR_TIMEOUT 67
+/** The request was canceled because the DNS subsystem was shut down. */
+#define DNS_ERR_SHUTDOWN 68
+/** The request was canceled via a call to evdns_cancel_request */
+#define DNS_ERR_CANCEL 69
+
+#define DNS_IPv4_A 1
+#define DNS_PTR 2
+#define DNS_IPv6_AAAA 3
+#define DNS_TXT 4
+
+#define DNS_QUERY_NO_SEARCH 1
+
+#define DNS_OPTION_SEARCH 1
+#define DNS_OPTION_NAMESERVERS 2
+#define DNS_OPTION_MISC 4
+#define DNS_OPTIONS_ALL 7
+
+/**
+ * The callback that contains the results from a lookup.
+ * - type is either DNS_IPv4_A or DNS_PTR or DNS_IPv6_AAAA
+ * - count contains the number of addresses of form type
+ * - ttl is the number of seconds the resolution may be cached for.
+ * - addresses needs to be cast according to type
+ */
+typedef void (*evdns_callback_type) (int result, char type, int count, int ttl, void *addresses, void *arg);
+
+struct evdns_base;
+struct event_base;
+
+/**
+  Initialize the asynchronous DNS library.
+
+  This function initializes support for non-blocking name resolution by
+  calling evdns_resolv_conf_parse() on UNIX and
+  evdns_config_windows_nameservers() on Windows.
+
+  @param event_base the event base to associate the dns client with
+  @param initialize_nameservers 1 if resolve.conf processing should occur
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_base_free()
+ */
+struct evdns_base * evdns_base_new(struct event_base *event_base, int initialize_nameservers);
+
+
+/**
+  Shut down the asynchronous DNS resolver and terminate all active requests.
+
+  If the 'fail_requests' option is enabled, all active requests will return
+  an empty result with the error flag set to DNS_ERR_SHUTDOWN. Otherwise,
+  the requests will be silently discarded.
+
+  @param evdns_base the evdns base to free
+  @param fail_requests if zero, active requests will be aborted; if non-zero,
+		active requests will return DNS_ERR_SHUTDOWN.
+  @see evdns_base_new()
+ */
+void evdns_base_free(struct evdns_base *base, int fail_requests);
+
+/**
+  Convert a DNS error code to a string.
+
+  @param err the DNS error code
+  @return a string containing an explanation of the error code
+*/
+const char *evdns_err_to_string(int err);
+
+
+/**
+  Add a nameserver.
+
+  The address should be an IPv4 address in network byte order.
+  The type of address is chosen so that it matches in_addr.s_addr.
+
+  @param base the evdns_base to which to add the name server
+  @param address an IP address in network byte order
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_base_nameserver_ip_add()
+ */
+int evdns_base_nameserver_add(struct evdns_base *base,
+                              unsigned long int address);
+
+/**
+  Get the number of configured nameservers.
+
+  This returns the number of configured nameservers (not necessarily the
+  number of running nameservers).  This is useful for double-checking
+  whether our calls to the various nameserver configuration functions
+  have been successful.
+
+  @param base the evdns_base to which to apply this operation
+  @return the number of configured nameservers
+  @see evdns_base_nameserver_add()
+ */
+int evdns_base_count_nameservers(struct evdns_base *base);
+
+/**
+  Remove all configured nameservers, and suspend all pending resolves.
+
+  Resolves will not necessarily be re-attempted until evdns_resume() is called.
+
+  @param base the evdns_base to which to apply this operation
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_base_resume()
+ */
+int evdns_base_clear_nameservers_and_suspend(struct evdns_base *base);
+
+
+/**
+  Resume normal operation and continue any suspended resolve requests.
+
+  Re-attempt resolves left in limbo after an earlier call to
+  evdns_clear_nameservers_and_suspend().
+
+  @param base the evdns_base to which to apply this operation
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_base_clear_nameservers_and_suspend()
+ */
+int evdns_base_resume(struct evdns_base *base);
+
+/**
+  Add a nameserver.
+
+  This function parses a n IPv4 or IPv6 address from a string and adds it as a
+  nameserver.  It supports the following formats:
+  - [IPv6Address]:port
+  - [IPv6Address]
+  - IPv6Address
+  - IPv4Address:port
+  - IPv4Address
+
+  If no port is specified, it defaults to 53.
+
+  @param base the evdns_base to which to apply this operation
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_base_nameserver_add()
+ */
+int evdns_base_nameserver_ip_add(struct evdns_base *base,
+                                 const char *ip_as_string);
+
+struct evdns_request;
+
+/**
+  Lookup an A record for a given name.
+
+  @param base the evdns_base to which to apply this operation
+  @param name a DNS hostname
+  @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query.
+  @param callback a callback function to invoke when the request is completed
+  @param ptr an argument to pass to the callback function
+  @return an evdns_request object if successful, or NULL if an error occurred.
+  @see evdns_resolve_ipv6(), evdns_resolve_reverse(), evdns_resolve_reverse_ipv6(), evdns_cancel_request()
+ */
+struct evdns_request *evdns_base_resolve_ipv4(struct evdns_base *base, const char *name, int flags, evdns_callback_type callback, void *ptr);
+
+/**
+  Lookup an AAAA record for a given name.
+
+  @param base the evdns_base to which to apply this operation
+  @param name a DNS hostname
+  @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query.
+  @param callback a callback function to invoke when the request is completed
+  @param ptr an argument to pass to the callback function
+  @return an evdns_request object if successful, or NULL if an error occurred.
+  @see evdns_resolve_ipv4(), evdns_resolve_reverse(), evdns_resolve_reverse_ipv6(), evdns_cancel_request()
+ */
+struct evdns_request *evdns_base_resolve_ipv6(struct evdns_base *base, const char *name, int flags, evdns_callback_type callback, void *ptr);
+
+struct in_addr;
+struct in6_addr;
+
+/**
+  Lookup a PTR record for a given IP address.
+
+  @param base the evdns_base to which to apply this operation
+  @param in an IPv4 address
+  @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query.
+  @param callback a callback function to invoke when the request is completed
+  @param ptr an argument to pass to the callback function
+  @return an evdns_request object if successful, or NULL if an error occurred.
+  @see evdns_resolve_reverse_ipv6(), evdns_cancel_request()
+ */
+struct evdns_request *evdns_base_resolve_reverse(struct evdns_base *base, const struct in_addr *in, int flags, evdns_callback_type callback, void *ptr);
+
+
+/**
+  Lookup a PTR record for a given IPv6 address.
+
+  @param base the evdns_base to which to apply this operation
+  @param in an IPv6 address
+  @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query.
+  @param callback a callback function to invoke when the request is completed
+  @param ptr an argument to pass to the callback function
+  @return an evdns_request object if successful, or NULL if an error occurred.
+  @see evdns_resolve_reverse_ipv6(), evdns_cancel_request()
+ */
+struct evdns_request *evdns_base_resolve_reverse_ipv6(struct evdns_base *base, const struct in6_addr *in, int flags, evdns_callback_type callback, void *ptr);
+
+/**
+  Cancels a pending DNS resolution request.
+
+  @param base the evdns_base that was used to make the request
+  @param req the evdns_request that was returned by calling a resolve function
+  @see evdns_base_resolve_ip4(), evdns_base_resolve_ipv6, evdns_base_resolve_reverse
+*/
+void evdns_cancel_request(struct evdns_base *base, struct evdns_request *req);
+
+/**
+  Set the value of a configuration option.
+
+  The currently available configuration options are:
+
+    ndots, timeout, max-timeouts, max-inflight, attempts, randomize-case,
+    bind-to.
+
+  The option name needs to end with a colon.
+
+  @param base the evdns_base to which to apply this operation
+  @param option the name of the configuration option to be modified
+  @param val the value to be set
+  @param flags either 0 | DNS_OPTION_SEARCH | DNS_OPTION_MISC
+  @return 0 if successful, or -1 if an error occurred
+ */
+int evdns_base_set_option(struct evdns_base *base, const char *option, const char *val, int flags);
+
+
+/**
+  Parse a resolv.conf file.
+
+  The 'flags' parameter determines what information is parsed from the
+  resolv.conf file. See the man page for resolv.conf for the format of this
+  file.
+
+  The following directives are not parsed from the file: sortlist, rotate,
+  no-check-names, inet6, debug.
+
+  If this function encounters an error, the possible return values are: 1 =
+  failed to open file, 2 = failed to stat file, 3 = file too large, 4 = out of
+  memory, 5 = short read from file, 6 = no nameservers listed in the file
+
+  @param base the evdns_base to which to apply this operation
+  @param flags any of DNS_OPTION_NAMESERVERS|DNS_OPTION_SEARCH|DNS_OPTION_MISC|
+         DNS_OPTIONS_ALL
+  @param filename the path to the resolv.conf file
+  @return 0 if successful, or various positive error codes if an error
+          occurred (see above)
+  @see resolv.conf(3), evdns_config_windows_nameservers()
+ */
+int evdns_base_resolv_conf_parse(struct evdns_base *base, int flags, const char *const filename);
+
+
+/**
+  Obtain nameserver information using the Windows API.
+
+  Attempt to configure a set of nameservers based on platform settings on
+  a win32 host.  Preferentially tries to use GetNetworkParams; if that fails,
+  looks in the registry.
+
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_resolv_conf_parse()
+ */
+#ifdef WIN32
+int evdns_base_config_windows_nameservers(struct evdns_base *);
+#define EVDNS_BASE_CONFIG_WINDOWS_NAMESERVERS_IMPLEMENTED
+#endif
+
+
+/**
+  Clear the list of search domains.
+ */
+void evdns_base_search_clear(struct evdns_base *base);
+
+
+/**
+  Add a domain to the list of search domains
+
+  @param domain the domain to be added to the search list
+ */
+void evdns_base_search_add(struct evdns_base *base, const char *domain);
+
+
+/**
+  Set the 'ndots' parameter for searches.
+
+  Sets the number of dots which, when found in a name, causes
+  the first query to be without any search domain.
+
+  @param ndots the new ndots parameter
+ */
+void evdns_base_search_ndots_set(struct evdns_base *base, const int ndots);
+
+/**
+  A callback that is invoked when a log message is generated
+
+  @param is_warning indicates if the log message is a 'warning'
+  @param msg the content of the log message
+ */
+typedef void (*evdns_debug_log_fn_type)(int is_warning, const char *msg);
+
+
+/**
+  Set the callback function to handle log messages.
+
+  @param fn the callback to be invoked when a log message is generated
+ */
+void evdns_set_log_fn(evdns_debug_log_fn_type fn);
+
+/**
+   Set a callback that will be invoked to generate transaction IDs.  By
+   default, we pick transaction IDs based on the current clock time, which
+   is bad for security.
+
+   @param fn the new callback, or NULL to use the default.
+ */
+void evdns_set_transaction_id_fn(uint16_t (*fn)(void));
+
+/**
+   Set a callback used to generate random bytes.  By default, we use
+   the same function as passed to evdns_set_transaction_id_fn to generate
+   bytes two at a time.  If a function is provided here, it's also used
+   to generate transaction IDs.
+*/
+void evdns_set_random_bytes_fn(void (*fn)(char *, size_t));
+
+#define DNS_NO_SEARCH 1
+
+/*
+ * Functions used to implement a DNS server.
+ */
+
+struct evdns_server_request;
+struct evdns_server_question;
+
+/**
+   A callback to implement a DNS server.  The callback function receives a DNS
+   request.  It should then optionally add a number of answers to the reply
+   using the evdns_server_request_add_*_reply functions, before calling either
+   evdns_server_request_respond to send the reply back, or
+   evdns_server_request_drop to decline to answer the request.
+
+   @param req A newly received request
+   @param user_data A pointer that was passed to
+      evdns_add_server_port_with_base().
+ */
+typedef void (*evdns_request_callback_fn_type)(struct evdns_server_request *, void *);
+#define EVDNS_ANSWER_SECTION 0
+#define EVDNS_AUTHORITY_SECTION 1
+#define EVDNS_ADDITIONAL_SECTION 2
+
+#define EVDNS_TYPE_A	   1
+#define EVDNS_TYPE_NS	   2
+#define EVDNS_TYPE_CNAME   5
+#define EVDNS_TYPE_SOA	   6
+#define EVDNS_TYPE_PTR	  12
+#define EVDNS_TYPE_MX	  15
+#define EVDNS_TYPE_TXT	  16
+#define EVDNS_TYPE_AAAA	  28
+
+#define EVDNS_QTYPE_AXFR 252
+#define EVDNS_QTYPE_ALL	 255
+
+#define EVDNS_CLASS_INET   1
+
+/* flags that can be set in answers; as part of the err parameter */
+#define EVDNS_FLAGS_AA	0x400
+#define EVDNS_FLAGS_RD	0x080
+
+/** Create a new DNS server port.
+
+    @param base The event base to handle events for the server port.
+    @param socket A UDP socket to accept DNS requests.
+    @param is_tcp Always 0 for now.
+    @param callback A function to invoke whenever we get a DNS request
+      on the socket.
+    @param user_data Data to pass to the callback.
+    @return an evdns_server_port structure for this server port.
+ */
+struct evdns_server_port *evdns_add_server_port_with_base(struct event_base *base, int socket, int is_tcp, evdns_request_callback_fn_type callback, void *user_data);
+/** Close down a DNS server port, and free associated structures. */
+void evdns_close_server_port(struct evdns_server_port *port);
+
+/** Sets some flags in a reply we're building.
+    Allows setting of the AA or RD flags
+ */
+void evdns_server_request_set_flags(struct evdns_server_request *req, int flags);
+
+/* Functions to add an answer to an in-progress DNS reply.
+ */
+int evdns_server_request_add_reply(struct evdns_server_request *req, int section, const char *name, int type, int dns_class, int ttl, int datalen, int is_name, const char *data);
+int evdns_server_request_add_a_reply(struct evdns_server_request *req, const char *name, int n, void *addrs, int ttl);
+int evdns_server_request_add_aaaa_reply(struct evdns_server_request *req, const char *name, int n, void *addrs, int ttl);
+int evdns_server_request_add_ptr_reply(struct evdns_server_request *req, struct in_addr *in, const char *inaddr_name, const char *hostname, int ttl);
+int evdns_server_request_add_cname_reply(struct evdns_server_request *req, const char *name, const char *cname, int ttl);
+
+/**
+   Send back a response to a DNS request, and free the request structure.
+*/
+int evdns_server_request_respond(struct evdns_server_request *req, int err);
+/**
+   Free a DNS request without sending back a reply.
+*/
+int evdns_server_request_drop(struct evdns_server_request *req);
+struct sockaddr;
+/**
+    Get the address that made a DNS request.
+ */
+int evdns_server_request_get_requesting_addr(struct evdns_server_request *_req, struct sockaddr *sa, int addr_len);
+
+/*
+ * Structures used to implement a DNS server.
+ */
+
+struct evdns_server_request {
+	int flags;
+	int nquestions;
+	struct evdns_server_question **questions;
+};
+struct evdns_server_question {
+	int type;
+#ifdef __cplusplus
+	int dns_question_class;
+#else
+	/* You should refer to this field as "dns_question_class".  The
+	 * name "class" works in C for backward compatibility, and will be
+	 * removed in a future version. (1.5 or later). */
+	int class;
+#define dns_question_class class
+#endif
+	char name[1];
+};
+
+/**
+  Initialize the asynchronous DNS library.
+
+  This function initializes support for non-blocking name resolution by
+  calling evdns_resolv_conf_parse() on UNIX and
+  evdns_config_windows_nameservers() on Windows.
+
+  @deprecated This function is deprecated because it always uses the current
+    event base, and is easily confused by multiple calls to event_init(), and
+    so is not safe for multithreaded use.  Additionally, it allocates a global
+    structure that only one thread can use. The replacement is
+    evdns_base_new().
+
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_shutdown()
+ */
+int evdns_init(void);
+
+/**
+  Shut down the asynchronous DNS resolver and terminate all active requests.
+
+  If the 'fail_requests' option is enabled, all active requests will return
+  an empty result with the error flag set to DNS_ERR_SHUTDOWN. Otherwise,
+  the requests will be silently discarded.
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which evdns_base it applies to.  The recommended
+    function is evdns_base_shutdown().
+
+  @param fail_requests if zero, active requests will be aborted; if non-zero,
+		active requests will return DNS_ERR_SHUTDOWN.
+  @see evdns_init()
+ */
+void evdns_shutdown(int fail_requests);
+
+/**
+  Add a nameserver.
+
+  The address should be an IPv4 address in network byte order.
+  The type of address is chosen so that it matches in_addr.s_addr.
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which evdns_base it applies to.  The recommended
+    function is evdns_base_nameserver_add().
+
+  @param address an IP address in network byte order
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_nameserver_ip_add()
+ */
+int evdns_nameserver_add(unsigned long int address);
+
+/**
+  Get the number of configured nameservers.
+
+  This returns the number of configured nameservers (not necessarily the
+  number of running nameservers).  This is useful for double-checking
+  whether our calls to the various nameserver configuration functions
+  have been successful.
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which evdns_base it applies to.  The recommended
+    function is evdns_base_count_nameservers().
+
+  @return the number of configured nameservers
+  @see evdns_nameserver_add()
+ */
+int evdns_count_nameservers(void);
+
+/**
+  Remove all configured nameservers, and suspend all pending resolves.
+
+  Resolves will not necessarily be re-attempted until evdns_resume() is called.
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which evdns_base it applies to.  The recommended
+    function is evdns_base_clear_nameservers_and_suspend().
+
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_resume()
+ */
+int evdns_clear_nameservers_and_suspend(void);
+
+/**
+  Resume normal operation and continue any suspended resolve requests.
+
+  Re-attempt resolves left in limbo after an earlier call to
+  evdns_clear_nameservers_and_suspend().
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which evdns_base it applies to.  The recommended
+    function is evdns_base_resume().
+
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_clear_nameservers_and_suspend()
+ */
+int evdns_resume(void);
+
+/**
+  Add a nameserver.
+
+  This wraps the evdns_nameserver_add() function by parsing a string as an IP
+  address and adds it as a nameserver.
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which evdns_base it applies to.  The recommended
+    function is evdns_base_nameserver_ip_add().
+
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_nameserver_add()
+ */
+int evdns_nameserver_ip_add(const char *ip_as_string);
+
+/**
+  Lookup an A record for a given name.
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which evdns_base it applies to.  The recommended
+    function is evdns_base_resolve_ipv4().
+
+  @param name a DNS hostname
+  @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query.
+  @param callback a callback function to invoke when the request is completed
+  @param ptr an argument to pass to the callback function
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_resolve_ipv6(), evdns_resolve_reverse(), evdns_resolve_reverse_ipv6()
+ */
+int evdns_resolve_ipv4(const char *name, int flags, evdns_callback_type callback, void *ptr);
+
+/**
+  Lookup an AAAA record for a given name.
+
+  @param name a DNS hostname
+  @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query.
+  @param callback a callback function to invoke when the request is completed
+  @param ptr an argument to pass to the callback function
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_resolve_ipv4(), evdns_resolve_reverse(), evdns_resolve_reverse_ipv6()
+ */
+int evdns_resolve_ipv6(const char *name, int flags, evdns_callback_type callback, void *ptr);
+
+struct in_addr;
+struct in6_addr;
+
+/**
+  Lookup a PTR record for a given IP address.
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which evdns_base it applies to.  The recommended
+    function is evdns_base_resolve_reverse().
+
+  @param in an IPv4 address
+  @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query.
+  @param callback a callback function to invoke when the request is completed
+  @param ptr an argument to pass to the callback function
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_resolve_reverse_ipv6()
+ */
+int evdns_resolve_reverse(const struct in_addr *in, int flags, evdns_callback_type callback, void *ptr);
+
+/**
+  Lookup a PTR record for a given IPv6 address.
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which evdns_base it applies to.  The recommended
+    function is evdns_base_resolve_reverse_ipv6().
+
+  @param in an IPv6 address
+  @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query.
+  @param callback a callback function to invoke when the request is completed
+  @param ptr an argument to pass to the callback function
+  @return 0 if successful, or -1 if an error occurred
+  @see evdns_resolve_reverse_ipv6()
+ */
+int evdns_resolve_reverse_ipv6(const struct in6_addr *in, int flags, evdns_callback_type callback, void *ptr);
+
+/**
+  Lookup a TXT entry for a specified DNS name.
+  @param name a DNS name
+  @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query.
+  @param callback a callback function to invoke when the request is completed
+  @param ptr an argument to pass to the callback function
+  @return 0 if successful, or -1 if an error occurred
+*/
+int evdns_resolve_txt(const char *in, int flags, evdns_callback_type callback, void *ptr);
+
+
+/**
+  Set the value of a configuration option.
+
+  The currently available configuration options are:
+
+    ndots, timeout, max-timeouts, max-inflight, and attempts
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which evdns_base it applies to.  The recommended
+    function is evdns_base_set_option().
+
+  @param option the name of the configuration option to be modified
+  @param val the value to be set
+  @param flags either 0 | DNS_OPTION_SEARCH | DNS_OPTION_MISC
+  @return 0 if successful, or -1 if an error occurred
+ */
+int evdns_set_option(const char *option, const char *val, int flags);
+
+/**
+  Parse a resolv.conf file.
+
+  The 'flags' parameter determines what information is parsed from the
+  resolv.conf file. See the man page for resolv.conf for the format of this
+  file.
+
+  The following directives are not parsed from the file: sortlist, rotate,
+  no-check-names, inet6, debug.
+
+  If this function encounters an error, the possible return values are: 1 =
+  failed to open file, 2 = failed to stat file, 3 = file too large, 4 = out of
+  memory, 5 = short read from file, 6 = no nameservers listed in the file
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which evdns_base it applies to.  The recommended
+    function is evdns_base_resolv_conf_parse().
+
+  @param flags any of DNS_OPTION_NAMESERVERS|DNS_OPTION_SEARCH|DNS_OPTION_MISC|
+         DNS_OPTIONS_ALL
+  @param filename the path to the resolv.conf file
+  @return 0 if successful, or various positive error codes if an error
+          occurred (see above)
+  @see resolv.conf(3), evdns_config_windows_nameservers()
+ */
+int evdns_resolv_conf_parse(int flags, const char *const filename);
+
+/**
+  Clear the list of search domains.
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which evdns_base it applies to.  The recommended
+    function is evdns_base_search_clear().
+ */
+void evdns_search_clear(void);
+
+/**
+  Add a domain to the list of search domains
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which evdns_base it applies to.  The recommended
+    function is evdns_base_search_add().
+
+  @param domain the domain to be added to the search list
+ */
+void evdns_search_add(const char *domain);
+
+/**
+  Set the 'ndots' parameter for searches.
+
+  Sets the number of dots which, when found in a name, causes
+  the first query to be without any search domain.
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which evdns_base it applies to.  The recommended
+    function is evdns_base_search_ndots_set().
+
+  @param ndots the new ndots parameter
+ */
+void evdns_search_ndots_set(const int ndots);
+
+/**
+   As evdns_server_new_with_base.
+
+  @deprecated This function is deprecated because it does not allow the
+    caller to specify which even_base it uses.  The recommended
+    function is evdns_add_server_port_with_base().
+
+*/
+struct evdns_server_port *evdns_add_server_port(int socket, int is_tcp, evdns_request_callback_fn_type callback, void *user_data);
+
+
+#endif /* _EVDNS_H_ */
diff --git a/src/lua/lua_task.c b/src/lua/lua_task.c
index a762cb660..0f7a92edb 100644
--- a/src/lua/lua_task.c
+++ b/src/lua/lua_task.c
@@ -26,7 +26,7 @@
 #include "lua_common.h"
 #include "../message.h"
 #include "../expressions.h"
-#include <evdns.h>
+#include "../evdns/evdns.h"
 
 /* Task methods */
 LUA_FUNCTION_DEF (task, get_message);
diff --git a/src/plugins/surbl.c b/src/plugins/surbl.c
index 2557e6e2e..dd4e84234 100644
--- a/src/plugins/surbl.c
+++ b/src/plugins/surbl.c
@@ -31,7 +31,7 @@
 #include "../message.h"
 #include "../view.h"
 #include "../map.h"
-#include <evdns.h>
+#include "../evdns/evdns.h"
 
 #include "surbl.h"
 
diff --git a/src/spf.c b/src/spf.c
new file mode 100644
index 000000000..857bcda99
--- /dev/null
+++ b/src/spf.c
@@ -0,0 +1,338 @@
+/*
+ * Copyright (c) 2009, Rambler media
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY Rambler media ''AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL Rambler BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "evdns/evdns.h"
+#include "spf.h"
+#include "main.h"
+#include "message.h"
+#include "filter.h"
+
+#define SPF_VER_STR "spf=v1"
+#define SPF_ALL "all"
+#define SPF_A "a"
+#define SPF_IP4 "ip4"
+#define SPF_IP6 "ip6"
+#define SPF_PTR "ptr"
+#define SPF_MX "mx"
+#define SPF_EXISTS "exists"
+#define SPF_INCLUDE "include"
+#define SPF_REDIRECT "redirect"
+#define SPF_EXP "exp"
+
+/**
+ * State machine for SPF record:
+ *
+ * spf_mech ::= +|-|~|?
+ *
+ * spf_body ::= spf=v1 <spf_command> [<spf_command>]
+ * spf_command ::= [spf_mech]all|a|<ip4>|<ip6>|ptr|mx|<exists>|<include>|<redirect>
+ *
+ * spf_domain ::= [:domain][/mask]
+ * spf_ip4 ::= ip[/mask]
+ * ip4 ::= ip4:<spf_ip4>
+ * mx ::= mx<spf_domain>
+ * a ::= a<spf_domain>
+ * ptr ::= ptr[:domain]
+ * exists ::= exists:domain
+ * include ::= include:domain
+ * redirect ::= redirect:domain
+ * exp ::= exp:domain
+ *
+ */
+
+struct spf_dns_cb {
+	struct spf_record *rec;
+	struct spf_addr *addr;
+};
+
+/* Determine spf mech */
+static spf_mech_t
+check_spf_mech (const char *elt, gboolean *need_shift)
+{
+	g_assert (elt != NULL);
+	
+	*need_shift = TRUE;
+	
+	switch (*elt) {
+		case '-':
+			return SPF_FAIL;
+		case '~':
+			return SPF_SOFT_FAIL;
+		case '+':
+			return SPF_PASS;
+		case '?':
+			return SPF_NEUTRAL;
+		default:
+			*need_shift = FALSE;
+			return SPF_PASS;	
+	}
+}
+
+static void
+parse_spf_a (struct worker_task *task, const char *begin, struct spf_record *rec, struct spf_addr *addr)
+{
+	struct spf_dns_cb *cb;
+}
+
+static void
+parse_spf_ptr (struct worker_task *task, const char *begin, struct spf_record *rec, struct spf_addr *addr)
+{
+	struct spf_dns_cb *cb;
+
+}
+
+static void
+parse_spf_mx (struct worker_task *task, const char *begin, struct spf_record *rec, struct spf_addr *addr)
+{
+	struct spf_dns_cb *cb;
+
+}
+
+static void
+parse_spf_all (struct worker_task *task, const char *begin, struct spf_record *rec, struct spf_addr *addr)
+{
+
+}
+
+static void
+parse_spf_ip4 (struct worker_task *task, const char *begin, struct spf_record *rec, struct spf_addr *addr)
+{
+
+}
+
+static void
+parse_spf_include (struct worker_task *task, const char *begin, struct spf_record *rec, struct spf_addr *addr)
+{
+	struct spf_dns_cb *cb;
+
+}
+
+static void
+parse_spf_exp (struct worker_task *task, const char *begin, struct spf_record *rec, struct spf_addr *addr)
+{
+	struct spf_dns_cb *cb;
+
+}
+
+static void
+parse_spf_redirect (struct worker_task *task, const char *begin, struct spf_record *rec, struct spf_addr *addr)
+{
+	struct spf_dns_cb *cb;
+
+}
+
+static void
+parse_spf_exists (struct worker_task *task, const char *begin, struct spf_record *rec, struct spf_addr *addr)
+{
+	struct spf_dns_cb *cb;
+
+}
+
+/* Read current element and try to parse record */
+static gboolean
+parse_spf_record (struct worker_task *task, struct spf_record *rec)
+{
+	struct spf_addr *new;
+	gboolean need_shift;
+	char *begin;
+
+	if (*rec->cur_elt == NULL) {
+		return TRUE;
+	}
+	else {
+		/* Check spf mech */
+		new = memory_pool_alloc (task->task_pool, sizeof (struct spf_addr));
+		new->mech = check_spf_mech (*rec->cur_elt, &need_shift);
+		if (need_shift) {
+			begin = (*rec->cur_elt)++;
+		}
+		else {
+			begin = *rec->cur_elt;
+		}
+		/* Now check what we have */
+		switch (*begin) {
+			case 'a':
+				/* all or a */
+				if (strncmp (begin, SPF_A, sizeof (SPF_A) - 1) == 0) {
+					begin += sizeof (SPF_A) - 1;
+					parse_spf_a (task, begin, rec, new);
+				}
+				else if (strncmp (begin, SPF_ALL, sizeof (SPF_ALL) - 1) == 0) {
+					begin += sizeof (SPF_ALL) - 1;
+					parse_spf_all (task, begin, rec, new);
+				}
+				else {
+					msg_info ("parse_spf_record: bad spf command");
+				}
+				break;
+			case 'i':
+				/* include or ip4 */
+				if (strncmp (begin, SPF_IP4, sizeof (SPF_IP4) - 1) == 0) {
+					begin += sizeof (SPF_IP4) - 1;
+					parse_spf_ip4 (task, begin, rec, new);
+				}
+				else if (strncmp (begin, SPF_INCLUDE, sizeof (SPF_INCLUDE) - 1) == 0) {
+					begin += sizeof (SPF_INCLUDE) - 1;
+					parse_spf_include (task, begin, rec, new);
+				}
+				else {
+					msg_info ("parse_spf_record: bad spf command");
+				}
+				break;
+			case 'm':
+				/* mx */
+				if (strncmp (begin, SPF_MX, sizeof (SPF_MX) - 1) == 0) {
+					begin += sizeof (SPF_MX) - 1;
+					parse_spf_mx (task, begin, rec, new);
+				}
+				else {
+					msg_info ("parse_spf_record: bad spf command");
+				}
+				break;
+			case 'p':
+				/* ptr */
+				if (strncmp (begin, SPF_PTR, sizeof (SPF_PTR) - 1) == 0) {
+					begin += sizeof (SPF_PTR) - 1;
+					parse_spf_ptr (task, begin, rec, new);
+				}
+				else {
+					msg_info ("parse_spf_record: bad spf command");
+				}
+				break;
+			case 'e':
+				/* exp or exists */
+				if (strncmp (begin, SPF_EXP, sizeof (SPF_EXP) - 1) == 0) {
+					begin += sizeof (SPF_EXP) - 1;
+					parse_spf_exp (task, begin, rec, new);
+				}
+				else if (strncmp (begin, SPF_EXISTS, sizeof (SPF_EXISTS) - 1) == 0) {
+					begin += sizeof (SPF_EXISTS) - 1;
+					parse_spf_exists (task, begin, rec, new);
+				}
+				else {
+					msg_info ("parse_spf_record: bad spf command");
+				}
+				break;
+			case 'r':
+				/* redirect */
+				if (strncmp (begin, SPF_REDIRECT, sizeof (SPF_REDIRECT) - 1) == 0) {
+					begin += sizeof (SPF_REDIRECT) - 1;
+					parse_spf_redirect (task, begin, rec, new);
+				}
+				else {
+					msg_info ("parse_spf_record: bad spf command");
+				}
+				break;
+			default:
+				msg_info ("parse_spf_record: bad spf command");
+				break;
+		}
+		rec->addrs = g_list_prepend (rec->addrs, new);
+		rec->cur_elt ++;
+	}
+}
+
+static void
+spf_dns_callback (int result, char type, int count, int ttl, void *addresses, void *data)
+{
+	struct spf_record *rec = data;
+	char *begin;
+
+	if (result == DNS_ERR_NONE && type == DNS_TXT) {
+		if (addresses != NULL) {
+			begin = (char *)addresses;
+			if (strncmp (begin, SPF_VER_STR, sizeof (SPF_VER_STR) - 1) == 0) {
+				begin += sizeof (SPF_VER_STR) - 1;
+				while (g_ascii_isspace (*begin) && *begin) {
+					begin ++;
+				}
+			}
+			rec->elts = g_strsplit (begin, " ", 0);
+			if (rec->elts) {
+				memory_pool_add_destructor (rec->task->task_pool, (pool_destruct_func)g_strfreev, rec->elts);
+				rec->cur_elt = rec->elts;
+				while (!parse_spf_record (rec->task, rec));
+			}
+		}
+	}
+
+	rec->task->save.saved--;
+	if (rec->task->save.saved == 0 && rec->callback) {
+		rec->callback (rec, rec->task);
+	}
+	remove_forced_event (rec->task->s, (event_finalizer_t) spf_dns_callback);
+
+}
+
+
+gboolean
+resolve_spf (struct worker_task *task, spf_cb_t callback)
+{
+	struct spf_record *rec;
+	char *domain;
+	GList *domains;
+
+	rec = memory_pool_alloc0 (task->task_pool, sizeof (struct spf_record));
+	rec->task = task;
+	rec->callback = callback;
+
+	domain = strchr (task->from, '@');
+	if (domain != NULL) {
+		rec->cur_domain = memory_pool_strdup (task->task_pool, domain);
+		if ((domain = strchr (rec->cur_domain, '>')) != NULL) {
+			*domain = '\0';
+		}
+
+		if (evdns_resolve_txt (rec->cur_domain, DNS_QUERY_NO_SEARCH, spf_dns_callback, (void *)rec) == 0) {
+			task->save.saved++;
+			register_async_event (task->s, (event_finalizer_t) spf_dns_callback, NULL, TRUE);
+
+			return TRUE;
+		}
+	}
+	else {
+		domains = message_get_header (task->task_pool, task->message, "From");
+
+		if (domains != NULL) {
+			rec->cur_domain = memory_pool_strdup (task->task_pool, domains->data);
+			g_list_free (domains);
+			if ((domain = strchr (rec->cur_domain, '>')) != NULL) {
+				*domain = '\0';
+			}
+			if (evdns_resolve_txt (rec->cur_domain, DNS_QUERY_NO_SEARCH, spf_dns_callback, (void *)rec) == 0) {
+				task->save.saved++;
+				register_async_event (task->s, (event_finalizer_t) spf_dns_callback, NULL, TRUE);
+	
+				return TRUE;
+			}
+		}
+	}
+
+	return FALSE;
+}
+
+/* 
+ * vi:ts=4 
+ */