libev/c-ares migration; fix lookup chains

  - use idle-watchers for unwinding the c-ares stack (thanks to Marc Lehmann for the hint)
  - use the generic c-ares query & parse logic instead of the integrated call; we need to first do the a then fall back to the aaaa request which the c-ares default one doesn't implement
  - stop the shutdown watchers when finalizing one client

diff --git a/citadel/event_client.c b/citadel/event_client.c
index 5c16cdd5bf78baaee63b0a931867e3be10fe5e57..4a20ba1ba317b935bf5a0173121a47e99b98be76 100644 (file)
--- a/citadel/event_client.c
+++ b/citadel/event_client.c
@@ -127,6 +127,8 @@ void ShutDownCLient(AsyncIO *IO)
 {
        CtdlLogPrintf(CTDL_DEBUG, "EVENT x %d\n", IO->sock);
 
+       ev_cleanup_stop(event_base, &IO->abort_by_shutdown);
+
        if (IO->sock != 0)
        {
                ev_io_stop(event_base, &IO->send_event);
@@ -338,12 +340,12 @@ IO_recv_callback(struct ev_loop *loop, ev_io *watcher, int revents)
 }
 
 void
-IO_postdns_callback(struct ev_loop *loop, ev_timer *watcher, int revents)
+IO_postdns_callback(struct ev_loop *loop, ev_idle *watcher, int revents)
 {
        AsyncIO *IO = watcher->data;
        CtdlLogPrintf(CTDL_DEBUG, "event: %s\n", __FUNCTION__);
 
-       IO->PostDNS(IO);
+       IO->DNSQuery->PostDNS(IO);
 }
 
 eNextState event_connect_socket(AsyncIO *IO, double conn_timeout, double first_rw_timeout)

diff --git a/citadel/event_client.h b/citadel/event_client.h
index daf158dcbd22ea7e8bcf72ae1ede86805e866ab0..57d9204074b612ed4de2889e7ede7c92c4dbf8e1 100644 (file)
--- a/citadel/event_client.h
+++ b/citadel/event_client.h
@@ -20,6 +20,17 @@ typedef eReadState (*IO_LineReaderCallback)(AsyncIO *IO);
 typedef void (*ParseDNSAnswerCb)(AsyncIO*, unsigned char*, int);
 typedef void (*FreeDNSReply)(void *DNSData);
 
+typedef struct _DNSQueryParts {
+       ParseDNSAnswerCb DNS_CB;
+       IO_CallBack PostDNS;
+
+       int DNSStatus;
+       void *VParsedDNSReply;
+       FreeDNSReply DNSReplyFree;
+       void *Data;
+} DNSQueryParts;
+
+
 struct AsyncIO {
        StrBuf *Host;
        char service[32];
@@ -30,7 +41,6 @@ struct AsyncIO {
 
        /* connection related */
        int IP6;
-       struct hostent *HEnt;
        struct sockaddr_in6 Addr;
 
        int sock;
@@ -40,8 +50,8 @@ struct AsyncIO {
        ev_cleanup abort_by_shutdown;
 
        ev_timer conn_fail, 
-               rw_timeout,
-               unwind_stack_timeout;
+               rw_timeout;
+       ev_idle unwind_stack;
        ev_io recv_event, 
                send_event, 
                conn_event;
@@ -62,19 +72,11 @@ struct AsyncIO {
 
        IO_LineReaderCallback LineReader; /* if we have linereaders, maybe we want to read more lines before the real application logic is called? */
 
-
-       int active_dns_event;
        ev_io dns_recv_event, 
                dns_send_event;
        struct ares_options DNSOptions;
        ares_channel DNSChannel;
-
-       ParseDNSAnswerCb DNS_CB;
-       IO_CallBack PostDNS;
-
-       int DNSStatus;
-       void *VParsedDNSReply;
-       FreeDNSReply DNSReplyFree;
+       DNSQueryParts *DNSQuery;
 
        /* Custom data; its expected to contain  AsyncIO so we can save malloc()s... */
        DeleteHashDataFunc DeleteData; /* so if we have to destroy you, what to do... */
@@ -96,9 +98,11 @@ eNextState InitEventIO(AsyncIO *IO,
                       double conn_timeout, 
                       double first_rw_timeout,
                       int ReadFirst);
-void IO_postdns_callback(struct ev_loop *loop, ev_timer *watcher, int revents);
+void IO_postdns_callback(struct ev_loop *loop, ev_idle *watcher, int revents);
+
+int QueueQuery(ns_type Type, const char *name, AsyncIO *IO, DNSQueryParts *QueryParts, IO_CallBack PostDNS);
+void QueueGetHostByName(AsyncIO *IO, const char *Hostname, DNSQueryParts *QueryParts, IO_CallBack PostDNS);
 
-int QueueQuery(ns_type Type, char *name, AsyncIO *IO, IO_CallBack PostDNS);
 void QueryCbDone(AsyncIO *IO);
 
 void StopClient(AsyncIO *IO);

diff --git a/citadel/modules/c-ares-dns/serv_c-ares-dns.c b/citadel/modules/c-ares-dns/serv_c-ares-dns.c
index e7a0f57e28aa2e5958096fcdcfbef1370f74721d..4534d88ef2d092c410138042ecf5274be6b8ba94 100644 (file)
--- a/citadel/modules/c-ares-dns/serv_c-ares-dns.c
+++ b/citadel/modules/c-ares-dns/serv_c-ares-dns.c
@@ -69,12 +69,12 @@ static void HostByAddrCb(void *data,
                          struct hostent *hostent) 
 {
        AsyncIO *IO = data;
-       IO->DNSStatus = status;
+       IO->DNSQuery->DNSStatus = status;
        if  (status != ARES_SUCCESS) {
 //             ResolveError(*cb, status);
                return;
        }
-       IO->Data = hostent;
+       IO->DNSQuery->Data = hostent;
 /// TODO: howto free this??
 }
 
@@ -82,17 +82,17 @@ static void ParseAnswerA(AsyncIO *IO, unsigned char* abuf, int alen)
 {
        struct hostent* host;
 
-       if (IO->VParsedDNSReply != NULL)
-               IO->DNSReplyFree(IO->VParsedDNSReply);
-       IO->VParsedDNSReply = NULL;
+       if (IO->DNSQuery->VParsedDNSReply != NULL)
+               IO->DNSQuery->DNSReplyFree(IO->DNSQuery->VParsedDNSReply);
+       IO->DNSQuery->VParsedDNSReply = NULL;
 
-       IO->DNSStatus = ares_parse_a_reply(abuf, alen, &host, NULL, NULL);
-       if (IO->DNSStatus != ARES_SUCCESS) {
+       IO->DNSQuery->DNSStatus = ares_parse_a_reply(abuf, alen, &host, NULL, NULL);
+       if (IO->DNSQuery->DNSStatus != ARES_SUCCESS) {
 //    ResolveError(arg->js_cb, status);
                return;
        }
-       IO->VParsedDNSReply = host;
-       IO->DNSReplyFree = (FreeDNSReply) ares_free_hostent;
+       IO->DNSQuery->VParsedDNSReply = host;
+       IO->DNSQuery->DNSReplyFree = (FreeDNSReply) ares_free_hostent;
 }
 
 
@@ -100,17 +100,17 @@ static void ParseAnswerAAAA(AsyncIO *IO, unsigned char* abuf, int alen)
 {
        struct hostent* host;
 
-       if (IO->VParsedDNSReply != NULL)
-               IO->DNSReplyFree(IO->VParsedDNSReply);
-       IO->VParsedDNSReply = NULL;
+       if (IO->DNSQuery->VParsedDNSReply != NULL)
+               IO->DNSQuery->DNSReplyFree(IO->DNSQuery->VParsedDNSReply);
+       IO->DNSQuery->VParsedDNSReply = NULL;
 
-       IO->DNSStatus = ares_parse_aaaa_reply(abuf, alen, &host, NULL, NULL);
-       if (IO->DNSStatus != ARES_SUCCESS) {
+       IO->DNSQuery->DNSStatus = ares_parse_aaaa_reply(abuf, alen, &host, NULL, NULL);
+       if (IO->DNSQuery->DNSStatus != ARES_SUCCESS) {
 //    ResolveError(arg->js_cb, status);
                return;
        }
-       IO->VParsedDNSReply = host;
-       IO->DNSReplyFree = (FreeDNSReply) ares_free_hostent;
+       IO->DNSQuery->VParsedDNSReply = host;
+       IO->DNSQuery->DNSReplyFree = (FreeDNSReply) ares_free_hostent;
 }
 
 
@@ -118,19 +118,19 @@ static void ParseAnswerCNAME(AsyncIO *IO, unsigned char* abuf, int alen)
 {
        struct hostent* host;
 
-       if (IO->VParsedDNSReply != NULL)
-               IO->DNSReplyFree(IO->VParsedDNSReply);
-       IO->VParsedDNSReply = NULL;
+       if (IO->DNSQuery->VParsedDNSReply != NULL)
+               IO->DNSQuery->DNSReplyFree(IO->DNSQuery->VParsedDNSReply);
+       IO->DNSQuery->VParsedDNSReply = NULL;
 
-       IO->DNSStatus = ares_parse_a_reply(abuf, alen, &host, NULL, NULL);
-       if (IO->DNSStatus != ARES_SUCCESS) {
+       IO->DNSQuery->DNSStatus = ares_parse_a_reply(abuf, alen, &host, NULL, NULL);
+       if (IO->DNSQuery->DNSStatus != ARES_SUCCESS) {
 //    ResolveError(arg->js_cb, status);
                return;
        }
 
        // a CNAME lookup always returns a single record but
-       IO->VParsedDNSReply = host;
-       IO->DNSReplyFree = (FreeDNSReply) ares_free_hostent;
+       IO->DNSQuery->VParsedDNSReply = host;
+       IO->DNSQuery->DNSReplyFree = (FreeDNSReply) ares_free_hostent;
 }
 
 
@@ -138,18 +138,18 @@ static void ParseAnswerMX(AsyncIO *IO, unsigned char* abuf, int alen)
 {
        struct ares_mx_reply *mx_out;
 
-       if (IO->VParsedDNSReply != NULL)
-               IO->DNSReplyFree(IO->VParsedDNSReply);
-       IO->VParsedDNSReply = NULL;
+       if (IO->DNSQuery->VParsedDNSReply != NULL)
+               IO->DNSQuery->DNSReplyFree(IO->DNSQuery->VParsedDNSReply);
+       IO->DNSQuery->VParsedDNSReply = NULL;
 
-       IO->DNSStatus = ares_parse_mx_reply(abuf, alen, &mx_out);
-       if (IO->DNSStatus != ARES_SUCCESS) {
+       IO->DNSQuery->DNSStatus = ares_parse_mx_reply(abuf, alen, &mx_out);
+       if (IO->DNSQuery->DNSStatus != ARES_SUCCESS) {
 //    ResolveError(arg->js_cb, status);
                return;
        }
 
-       IO->VParsedDNSReply = mx_out;
-       IO->DNSReplyFree = (FreeDNSReply) ares_free_data;
+       IO->DNSQuery->VParsedDNSReply = mx_out;
+       IO->DNSQuery->DNSReplyFree = (FreeDNSReply) ares_free_data;
 }
 
 
@@ -157,17 +157,17 @@ static void ParseAnswerNS(AsyncIO *IO, unsigned char* abuf, int alen)
 {
        struct hostent* host;
 
-       if (IO->VParsedDNSReply != NULL)
-               IO->DNSReplyFree(IO->VParsedDNSReply);
-       IO->VParsedDNSReply = NULL;
+       if (IO->DNSQuery->VParsedDNSReply != NULL)
+               IO->DNSQuery->DNSReplyFree(IO->DNSQuery->VParsedDNSReply);
+       IO->DNSQuery->VParsedDNSReply = NULL;
 
-       IO->DNSStatus = ares_parse_ns_reply(abuf, alen, &host);
-       if (IO->DNSStatus != ARES_SUCCESS) {
+       IO->DNSQuery->DNSStatus = ares_parse_ns_reply(abuf, alen, &host);
+       if (IO->DNSQuery->DNSStatus != ARES_SUCCESS) {
 //    ResolveError(arg->js_cb, status);
                return;
        }
-       IO->VParsedDNSReply = host;
-       IO->DNSReplyFree = (FreeDNSReply) ares_free_hostent;
+       IO->DNSQuery->VParsedDNSReply = host;
+       IO->DNSQuery->DNSReplyFree = (FreeDNSReply) ares_free_hostent;
 }
 
 
@@ -175,18 +175,18 @@ static void ParseAnswerSRV(AsyncIO *IO, unsigned char* abuf, int alen)
 {
        struct ares_srv_reply *srv_out;
 
-       if (IO->VParsedDNSReply != NULL)
-               IO->DNSReplyFree(IO->VParsedDNSReply);
-       IO->VParsedDNSReply = NULL;
+       if (IO->DNSQuery->VParsedDNSReply != NULL)
+               IO->DNSQuery->DNSReplyFree(IO->DNSQuery->VParsedDNSReply);
+       IO->DNSQuery->VParsedDNSReply = NULL;
 
-       IO->DNSStatus = ares_parse_srv_reply(abuf, alen, &srv_out);
-       if (IO->DNSStatus != ARES_SUCCESS) {
+       IO->DNSQuery->DNSStatus = ares_parse_srv_reply(abuf, alen, &srv_out);
+       if (IO->DNSQuery->DNSStatus != ARES_SUCCESS) {
 //    ResolveError(arg->js_cb, status);
                return;
        }
 
-       IO->VParsedDNSReply = srv_out;
-       IO->DNSReplyFree = (FreeDNSReply) ares_free_data;
+       IO->DNSQuery->VParsedDNSReply = srv_out;
+       IO->DNSQuery->DNSReplyFree = (FreeDNSReply) ares_free_data;
 }
 
 
@@ -194,17 +194,17 @@ static void ParseAnswerTXT(AsyncIO *IO, unsigned char* abuf, int alen)
 {
        struct ares_txt_reply *txt_out;
 
-       if (IO->VParsedDNSReply != NULL)
-               IO->DNSReplyFree(IO->VParsedDNSReply);
-       IO->VParsedDNSReply = NULL;
+       if (IO->DNSQuery->VParsedDNSReply != NULL)
+               IO->DNSQuery->DNSReplyFree(IO->DNSQuery->VParsedDNSReply);
+       IO->DNSQuery->VParsedDNSReply = NULL;
 
-       IO->DNSStatus = ares_parse_txt_reply(abuf, alen, &txt_out);
-       if (IO->DNSStatus != ARES_SUCCESS) {
+       IO->DNSQuery->DNSStatus = ares_parse_txt_reply(abuf, alen, &txt_out);
+       if (IO->DNSQuery->DNSStatus != ARES_SUCCESS) {
 //    ResolveError(arg->js_cb, status);
                return;
        }
-       IO->VParsedDNSReply = txt_out;
-       IO->DNSReplyFree = (FreeDNSReply) ares_free_data;
+       IO->DNSQuery->VParsedDNSReply = txt_out;
+       IO->DNSQuery->DNSReplyFree = (FreeDNSReply) ares_free_data;
 }
 
 void QueryCb(void *arg,
@@ -215,23 +215,23 @@ void QueryCb(void *arg,
 {
        AsyncIO *IO = arg;
 
-       IO->DNSStatus = status;
+       IO->DNSQuery->DNSStatus = status;
        if (status == ARES_SUCCESS)
-               IO->DNS_CB(arg, abuf, alen);
+               IO->DNSQuery->DNS_CB(arg, abuf, alen);
        else
-               IO->DNSStatus = status;
-///    ev_io_stop(event_base, &IO->dns_io_event);
+               IO->DNSQuery->DNSStatus = status;
+///    ev_io_stop(event_base, &IO->DNSQuery->dns_io_event);
        
-       ev_timer_init(&IO->unwind_stack_timeout,
-                     IO_postdns_callback, 0.0, 0);
-       IO->unwind_stack_timeout.data = IO;
-       ev_timer_start(event_base, &IO->unwind_stack_timeout);
+       ev_idle_init(&IO->unwind_stack,
+                    IO_postdns_callback);
+       IO->unwind_stack.data = IO;
+       ev_idle_start(event_base, &IO->unwind_stack);
        CtdlLogPrintf(CTDL_DEBUG, "C-ARES: %s\n", __FUNCTION__);
 }
 
 void QueryCbDone(AsyncIO *IO)
 {
-       ev_timer_stop(event_base, &IO->unwind_stack_timeout);
+       ev_idle_stop(event_base, &IO->unwind_stack);
 }
 
 
@@ -245,40 +245,76 @@ void InitC_ares_dns(AsyncIO *IO)
                ares_init_options(&IO->DNSChannel, &IO->DNSOptions, optmask);
        }
 }
-int QueueQuery(ns_type Type, char *name, AsyncIO *IO, IO_CallBack PostDNS)
+
+void QueueGetHostByNameDone(void *Ctx, 
+                           int status,
+                           int timeouts,
+                           struct hostent *hostent)
+{
+       AsyncIO *IO = (AsyncIO *) Ctx;
+
+       IO->DNSQuery->DNSStatus = status;
+       IO->DNSQuery->VParsedDNSReply = hostent;
+       IO->DNSQuery->DNSReplyFree = (FreeDNSReply) ares_free_hostent;
+
+       ev_idle_init(&IO->unwind_stack,
+                    IO_postdns_callback);
+       IO->unwind_stack.data = IO;
+       ev_idle_start(event_base, &IO->unwind_stack);
+       CtdlLogPrintf(CTDL_DEBUG, "C-ARES: %s\n", __FUNCTION__);
+}
+
+void QueueGetHostByName(AsyncIO *IO, const char *Hostname, DNSQueryParts *QueryParts, IO_CallBack PostDNS)
+{
+       IO->DNSQuery = QueryParts;
+       IO->DNSQuery->PostDNS = PostDNS;
+
+       InitC_ares_dns(IO);
+
+       ares_gethostbyname(IO->DNSChannel,
+                          Hostname,   
+                          AF_INET6, /* it falls back to ipv4 in doubt... */
+                          QueueGetHostByNameDone,
+                          IO);
+//get_one_mx_host_ip_done);
+}
+int QueueQuery(ns_type Type, const char *name, AsyncIO *IO, DNSQueryParts *QueryParts, IO_CallBack PostDNS)
 {
        int length, family;
        char address_b[sizeof(struct in6_addr)];
 
+       IO->DNSQuery = QueryParts;
+       IO->DNSQuery->PostDNS = PostDNS;
+
        InitC_ares_dns(IO);
-       IO->PostDNS = PostDNS;
+
        switch(Type) {
        case ns_t_a:
-               IO->DNS_CB = ParseAnswerA;
+               IO->DNSQuery->DNS_CB = ParseAnswerA;
                break;
 
        case ns_t_aaaa:
-               IO->DNS_CB = ParseAnswerAAAA;
+               IO->DNSQuery->DNS_CB = ParseAnswerAAAA;
                break;
 
        case ns_t_mx:
-               IO->DNS_CB = ParseAnswerMX;
+               IO->DNSQuery->DNS_CB = ParseAnswerMX;
                break;
 
        case ns_t_ns:
-               IO->DNS_CB = ParseAnswerNS;
+               IO->DNSQuery->DNS_CB = ParseAnswerNS;
                break;
 
        case ns_t_txt:
-               IO->DNS_CB = ParseAnswerTXT;
+               IO->DNSQuery->DNS_CB = ParseAnswerTXT;
                break;
 
        case ns_t_srv:
-               IO->DNS_CB = ParseAnswerSRV;
+               IO->DNSQuery->DNS_CB = ParseAnswerSRV;
                break;
 
        case ns_t_cname:
-               IO->DNS_CB = ParseAnswerCNAME;
+               IO->DNSQuery->DNS_CB = ParseAnswerCNAME;
                break;
 
        case ns_t_ptr:
@@ -305,6 +341,7 @@ int QueueQuery(ns_type Type, char *name, AsyncIO *IO, IO_CallBack PostDNS)
        return 1;
 }
 
+
 static void DNS_send_callback(struct ev_loop *loop, ev_io *watcher, int revents)
 {
        AsyncIO *IO = watcher->data;
@@ -330,27 +367,23 @@ void SockStateCb(void *data, int sock, int read, int write)
 
        if (read) {
                if ((IO->dns_recv_event.fd != sock) &&
-                   (IO->dns_recv_event.fd != 0) && 
-                   ((IO->active_dns_event & EV_READ) != 0)) {
+                   (IO->dns_recv_event.fd != 0)) {
                        ev_io_stop(event_base, &IO->dns_recv_event);
                }
                IO->dns_recv_event.fd = sock;
                ev_io_init(&IO->dns_recv_event, DNS_recv_callback, IO->dns_recv_event.fd, EV_READ);
                IO->dns_recv_event.data = IO;
                ev_io_start(event_base, &IO->dns_recv_event);
-               IO->active_dns_event = IO->active_dns_event | EV_READ;
        } 
        if (write) {
                if ((IO->dns_send_event.fd != sock) &&
-                   (IO->dns_send_event.fd != 0) && 
-                   ((IO->active_dns_event & EV_WRITE) != 0)) {
+                   (IO->dns_send_event.fd != 0)) {
                        ev_io_stop(event_base, &IO->dns_send_event);
                }
                IO->dns_send_event.fd = sock;
                ev_io_init(&IO->dns_send_event, DNS_send_callback, IO->dns_send_event.fd, EV_WRITE);
                IO->dns_send_event.data = IO;
                ev_io_start(event_base, &IO->dns_send_event);
-               IO->active_dns_event = IO->active_dns_event | EV_WRITE;
        }
 /*
 
@@ -363,11 +396,8 @@ void SockStateCb(void *data, int sock, int read, int write)
        }
 */
        if ((read == 0) && (write == 0)) {
-               if ((IO->active_dns_event & EV_READ) != 0)
-                       ev_io_stop(event_base, &IO->dns_recv_event);
-               if ((IO->active_dns_event & EV_WRITE) != 0)
-                       ev_io_stop(event_base, &IO->dns_send_event);
-               IO->active_dns_event = 0;
+               ev_io_stop(event_base, &IO->dns_recv_event);
+               ev_io_stop(event_base, &IO->dns_send_event);
        }
 }
 

diff --git a/citadel/modules/smtp/serv_smtpeventclient.c b/citadel/modules/smtp/serv_smtpeventclient.c
index 3c4e6d0c8e96df41e71f2224570e81a9fc50207a..5d53110cbf0cd9e4b8ac8012c4b2056d58fe136b 100644 (file)
--- a/citadel/modules/smtp/serv_smtpeventclient.c
+++ b/citadel/modules/smtp/serv_smtpeventclient.c
@@ -160,7 +160,10 @@ typedef struct _stmp_out_msg {
        const char *mx_port;
        const char *mx_host;
 
+       DNSQueryParts MxLookup;
+       DNSQueryParts HostLookup;
        struct hostent *OneMX;
+///    struct hostent *HEnt;
 
        ParsedURL *Relay;
        ParsedURL *pCurrRelay;
@@ -177,7 +180,8 @@ void DeleteSmtpOutMsg(void *v)
        SmtpOutMsg *Msg = v;
 
        ares_free_data(Msg->AllMX);
-       
+       if (Msg->HostLookup.VParsedDNSReply != NULL)
+               Msg->HostLookup.DNSReplyFree(Msg->HostLookup.VParsedDNSReply);
        FreeStrBuf(&Msg->msgtext);
        FreeAsyncIOContents(&Msg->IO);
        free(Msg);
@@ -335,19 +339,19 @@ eNextState mx_connect_relay_ip(AsyncIO *IO)
                            1);
 }
 
-void get_one_mx_host_ip_done(void *Ctx, 
-                            int status,
-                            int timeouts,
-                            struct hostent *hostent)
+eNextState get_one_mx_host_ip_done(AsyncIO *IO)
 {
-       AsyncIO *IO = (AsyncIO *) Ctx;
        SmtpOutMsg *SendMsg = IO->Data;
-       eNextState State = eAbort;
+       struct hostent *hostent;
+
+       QueryCbDone(IO);
 
-       if ((status == ARES_SUCCESS) && (hostent != NULL) ) {
+       hostent = SendMsg->HostLookup.VParsedDNSReply;
+       if ((SendMsg->HostLookup.DNSStatus == ARES_SUCCESS) && 
+           (hostent != NULL) ) {
                
                IO->IP6  = hostent->h_addrtype == AF_INET6;
-               IO->HEnt = hostent;
+               ////IO->HEnt = hostent;
 
                memset(&IO->Addr, 0, sizeof(struct in6_addr));
                if (IO->IP6) {
@@ -368,15 +372,15 @@ void get_one_mx_host_ip_done(void *Ctx,
                        addr->sin_port = htons(IO->dport);
                        
                }
-               SendMsg->IO.HEnt = hostent;
+               ////SendMsg->IO.HEnt = hostent;
                SetConnectStatus(IO);
-               State = InitEventIO(IO, SendMsg, 
+               return InitEventIO(IO, SendMsg, 
                                   SMTP_C_ConnTimeout, 
                                   SMTP_C_ReadTimeouts[0],
                                   1);
        }
-       if ((State == eAbort) && (IO->sock != -1))
-               SMTP_C_Terminate(IO);
+       else
+               return SMTP_C_Terminate(IO);
 }
 
 const unsigned short DefaultMXPort = 25;
@@ -409,11 +413,17 @@ eNextState get_one_mx_host_ip(AsyncIO *IO)
                      Hostname, 
                      SendMsg->IO.dport);
 
-       ares_gethostbyname(SendMsg->IO.DNSChannel,
-                          Hostname,   
-                          AF_INET6, /* it falls back to ipv4 in doubt... */
-                          get_one_mx_host_ip_done,
-                          &SendMsg->IO);
+       if (!QueueQuery(ns_t_a, 
+                       Hostname, 
+                       &SendMsg->IO, 
+                       &SendMsg->HostLookup, 
+                       get_one_mx_host_ip_done))
+       {
+               SendMsg->MyQEntry->Status = 5;
+               StrBufPrintf(SendMsg->MyQEntry->StatusMessage, 
+                            "No MX hosts found for <%s>", SendMsg->node);
+               return IO->NextState;
+       }
        return IO->NextState;
 }
 
@@ -428,7 +438,7 @@ eNextState smtp_resolve_mx_done(AsyncIO *IO)
 
        SendMsg->IO.ErrMsg = SendMsg->MyQEntry->StatusMessage;
 
-       SendMsg->CurrMX = SendMsg->AllMX = IO->VParsedDNSReply;
+       SendMsg->CurrMX = SendMsg->AllMX = IO->DNSQuery->VParsedDNSReply;
        //// TODO: should we remove the current ares context???
        get_one_mx_host_ip(IO);
        return IO->NextState;
@@ -444,6 +454,7 @@ eNextState resolve_mx_records(AsyncIO *IO)
        if (!QueueQuery(ns_t_mx, 
                        SendMsg->node, 
                        &SendMsg->IO, 
+                       &SendMsg->MxLookup, 
                        smtp_resolve_mx_done))
        {
                SendMsg->MyQEntry->Status = 5;