libev/c-ares migration: unstack out ouf c-ares before querying new requests
[citadel.git] / citadel / modules / c-ares-dns / serv_c-ares-dns.c
1 /*
2  * Copyright (c) 1998-2009 by the citadel.org team
3  *
4  *  This program is free software; you can redistribute it and/or modify
5  *  it under the terms of the GNU General Public License as published by
6  *  the Free Software Foundation; either version 3 of the License, or
7  *  (at your option) any later version.
8  *
9  *  This program is distributed in the hope that it will be useful,
10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  *  GNU General Public License for more details.
13  *
14  *  You should have received a copy of the GNU General Public License
15  *  along with this program; if not, write to the Free Software
16  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
17  *
18  *  Inspired by NodeJS.org; thanks for the MX-Parser ;-)
19  */
20
21 #include "sysdep.h"
22 #include <stdlib.h>
23 #include <unistd.h>
24 #include <stdio.h>
25 #include <termios.h>
26 #include <fcntl.h>
27 #include <signal.h>
28 #include <pwd.h>
29 #include <errno.h>
30 #include <sys/types.h>
31 #include <syslog.h>
32
33 #if TIME_WITH_SYS_TIME
34 # include <sys/time.h>
35 # include <time.h>
36 #else
37 # if HAVE_SYS_TIME_H
38 #  include <sys/time.h>
39 # else
40 #  include <time.h>
41 # endif
42 #endif
43 #include <sys/wait.h>
44 #include <ctype.h>
45 #include <string.h>
46 #include <limits.h>
47 #include <sys/socket.h>
48 #include <netinet/in.h>
49 #include <arpa/inet.h>
50
51 #include <libcitadel.h>
52 #include "citadel.h"
53 #include "server.h"
54 #include "citserver.h"
55 #include "support.h"
56
57 #include "ctdl_module.h"
58 #include "event_client.h"
59
60
61 extern struct ev_loop *event_base;
62
63 void SockStateCb(void *data, int sock, int read, int write);
64
65
66 static void HostByAddrCb(void *data,
67                          int status,
68                          int timeouts,
69                          struct hostent *hostent) 
70 {
71         AsyncIO *IO = data;
72         IO->DNSStatus = status;
73         if  (status != ARES_SUCCESS) {
74 //              ResolveError(*cb, status);
75                 return;
76         }
77         IO->Data = hostent;
78 /// TODO: howto free this??
79 }
80
81 static void ParseAnswerA(AsyncIO *IO, unsigned char* abuf, int alen) 
82 {
83         struct hostent* host;
84
85         if (IO->VParsedDNSReply != NULL)
86                 IO->DNSReplyFree(IO->VParsedDNSReply);
87         IO->VParsedDNSReply = NULL;
88
89         IO->DNSStatus = ares_parse_a_reply(abuf, alen, &host, NULL, NULL);
90         if (IO->DNSStatus != ARES_SUCCESS) {
91 //    ResolveError(arg->js_cb, status);
92                 return;
93         }
94         IO->VParsedDNSReply = host;
95         IO->DNSReplyFree = (FreeDNSReply) ares_free_hostent;
96 }
97
98
99 static void ParseAnswerAAAA(AsyncIO *IO, unsigned char* abuf, int alen) 
100 {
101         struct hostent* host;
102
103         if (IO->VParsedDNSReply != NULL)
104                 IO->DNSReplyFree(IO->VParsedDNSReply);
105         IO->VParsedDNSReply = NULL;
106
107         IO->DNSStatus = ares_parse_aaaa_reply(abuf, alen, &host, NULL, NULL);
108         if (IO->DNSStatus != ARES_SUCCESS) {
109 //    ResolveError(arg->js_cb, status);
110                 return;
111         }
112         IO->VParsedDNSReply = host;
113         IO->DNSReplyFree = (FreeDNSReply) ares_free_hostent;
114 }
115
116
117 static void ParseAnswerCNAME(AsyncIO *IO, unsigned char* abuf, int alen) 
118 {
119         struct hostent* host;
120
121         if (IO->VParsedDNSReply != NULL)
122                 IO->DNSReplyFree(IO->VParsedDNSReply);
123         IO->VParsedDNSReply = NULL;
124
125         IO->DNSStatus = ares_parse_a_reply(abuf, alen, &host, NULL, NULL);
126         if (IO->DNSStatus != ARES_SUCCESS) {
127 //    ResolveError(arg->js_cb, status);
128                 return;
129         }
130
131         // a CNAME lookup always returns a single record but
132         IO->VParsedDNSReply = host;
133         IO->DNSReplyFree = (FreeDNSReply) ares_free_hostent;
134 }
135
136
137 static void ParseAnswerMX(AsyncIO *IO, unsigned char* abuf, int alen) 
138 {
139         struct ares_mx_reply *mx_out;
140
141         if (IO->VParsedDNSReply != NULL)
142                 IO->DNSReplyFree(IO->VParsedDNSReply);
143         IO->VParsedDNSReply = NULL;
144
145         IO->DNSStatus = ares_parse_mx_reply(abuf, alen, &mx_out);
146         if (IO->DNSStatus != ARES_SUCCESS) {
147 //    ResolveError(arg->js_cb, status);
148                 return;
149         }
150
151         IO->VParsedDNSReply = mx_out;
152         IO->DNSReplyFree = (FreeDNSReply) ares_free_data;
153 }
154
155
156 static void ParseAnswerNS(AsyncIO *IO, unsigned char* abuf, int alen) 
157 {
158         struct hostent* host;
159
160         if (IO->VParsedDNSReply != NULL)
161                 IO->DNSReplyFree(IO->VParsedDNSReply);
162         IO->VParsedDNSReply = NULL;
163
164         IO->DNSStatus = ares_parse_ns_reply(abuf, alen, &host);
165         if (IO->DNSStatus != ARES_SUCCESS) {
166 //    ResolveError(arg->js_cb, status);
167                 return;
168         }
169         IO->VParsedDNSReply = host;
170         IO->DNSReplyFree = (FreeDNSReply) ares_free_hostent;
171 }
172
173
174 static void ParseAnswerSRV(AsyncIO *IO, unsigned char* abuf, int alen) 
175 {
176         struct ares_srv_reply *srv_out;
177
178         if (IO->VParsedDNSReply != NULL)
179                 IO->DNSReplyFree(IO->VParsedDNSReply);
180         IO->VParsedDNSReply = NULL;
181
182         IO->DNSStatus = ares_parse_srv_reply(abuf, alen, &srv_out);
183         if (IO->DNSStatus != ARES_SUCCESS) {
184 //    ResolveError(arg->js_cb, status);
185                 return;
186         }
187
188         IO->VParsedDNSReply = srv_out;
189         IO->DNSReplyFree = (FreeDNSReply) ares_free_data;
190 }
191
192
193 static void ParseAnswerTXT(AsyncIO *IO, unsigned char* abuf, int alen) 
194 {
195         struct ares_txt_reply *txt_out;
196
197         if (IO->VParsedDNSReply != NULL)
198                 IO->DNSReplyFree(IO->VParsedDNSReply);
199         IO->VParsedDNSReply = NULL;
200
201         IO->DNSStatus = ares_parse_txt_reply(abuf, alen, &txt_out);
202         if (IO->DNSStatus != ARES_SUCCESS) {
203 //    ResolveError(arg->js_cb, status);
204                 return;
205         }
206         IO->VParsedDNSReply = txt_out;
207         IO->DNSReplyFree = (FreeDNSReply) ares_free_data;
208 }
209
210 void QueryCb(void *arg,
211              int status,
212              int timeouts,
213              unsigned char* abuf,
214              int alen) 
215 {
216         AsyncIO *IO = arg;
217
218         IO->DNSStatus = status;
219         if (status == ARES_SUCCESS)
220                 IO->DNS_CB(arg, abuf, alen);
221         else
222                 IO->DNSStatus = status;
223 ///     ev_io_stop(event_base, &IO->dns_io_event);
224         
225         ev_timer_init(&IO->unwind_stack_timeout,
226                       IO_postdns_callback, 0.0, 0);
227         IO->unwind_stack_timeout.data = IO;
228         ev_timer_start(event_base, &IO->unwind_stack_timeout);
229 }
230
231 void QueryCbDone(AsyncIO *IO)
232 {
233         ev_timer_stop(event_base, &IO->unwind_stack_timeout);
234 }
235
236
237 void InitC_ares_dns(AsyncIO *IO)
238 {
239         int optmask = 0;
240         if (IO->DNSChannel == NULL) {
241                 optmask |= ARES_OPT_SOCK_STATE_CB;
242                 IO->DNSOptions.sock_state_cb = SockStateCb;
243                 IO->DNSOptions.sock_state_cb_data = IO;
244                 ares_init_options(&IO->DNSChannel, &IO->DNSOptions, optmask);
245         }
246 }
247 int QueueQuery(ns_type Type, char *name, AsyncIO *IO, IO_CallBack PostDNS)
248 {
249         int length, family;
250         char address_b[sizeof(struct in6_addr)];
251
252         InitC_ares_dns(IO);
253         IO->PostDNS = PostDNS;
254         switch(Type) {
255         case ns_t_a:
256                 IO->DNS_CB = ParseAnswerA;
257                 break;
258
259         case ns_t_aaaa:
260                 IO->DNS_CB = ParseAnswerAAAA;
261                 break;
262
263         case ns_t_mx:
264                 IO->DNS_CB = ParseAnswerMX;
265                 break;
266
267         case ns_t_ns:
268                 IO->DNS_CB = ParseAnswerNS;
269                 break;
270
271         case ns_t_txt:
272                 IO->DNS_CB = ParseAnswerTXT;
273                 break;
274
275         case ns_t_srv:
276                 IO->DNS_CB = ParseAnswerSRV;
277                 break;
278
279         case ns_t_cname:
280                 IO->DNS_CB = ParseAnswerCNAME;
281                 break;
282
283         case ns_t_ptr:
284
285
286                 if (inet_pton(AF_INET, name, &address_b) == 1) {
287                         length = sizeof(struct in_addr);
288                         family = AF_INET;
289                 } else if (inet_pton(AF_INET6, name, &address_b) == 1) {
290                         length = sizeof(struct in6_addr);
291                         family = AF_INET6;
292                 } else {
293                         return -1;
294                 }
295
296                 ares_gethostbyaddr(IO->DNSChannel, address_b, length, family, HostByAddrCb, IO);
297
298                 return 1;
299
300         default:
301                 return 0;
302         }
303         ares_query(IO->DNSChannel, name, ns_c_in, Type, QueryCb, IO);
304         return 1;
305 }
306
307 static void DNS_send_callback(struct ev_loop *loop, ev_io *watcher, int revents)
308 {
309         AsyncIO *IO = watcher->data;
310         
311         ares_process_fd(IO->DNSChannel, ARES_SOCKET_BAD, IO->dns_send_event.fd);
312 }
313 static void DNS_recv_callback(struct ev_loop *loop, ev_io *watcher, int revents)
314 {
315         AsyncIO *IO = watcher->data;
316         
317         ares_process_fd(IO->DNSChannel, IO->dns_recv_event.fd, ARES_SOCKET_BAD);
318 }
319
320 void SockStateCb(void *data, int sock, int read, int write) 
321 {
322 /*
323         struct timeval tvbuf, maxtv, *ret;
324         
325         int64_t time = 10;
326 */
327         AsyncIO *IO = data;
328 /* already inside of the event queue. */        
329
330         if (read) {
331                 if ((IO->dns_recv_event.fd != sock) &&
332                     (IO->dns_recv_event.fd != 0) && 
333                     ((IO->active_dns_event & EV_READ) != 0)) {
334                         ev_io_stop(event_base, &IO->dns_recv_event);
335                 }
336                 IO->dns_recv_event.fd = sock;
337                 ev_io_init(&IO->dns_recv_event, DNS_recv_callback, IO->dns_recv_event.fd, EV_READ);
338                 IO->dns_recv_event.data = IO;
339                 ev_io_start(event_base, &IO->dns_recv_event);
340                 IO->active_dns_event = IO->active_dns_event | EV_READ;
341         } 
342         if (write) {
343                 if ((IO->dns_send_event.fd != sock) &&
344                     (IO->dns_send_event.fd != 0) && 
345                     ((IO->active_dns_event & EV_WRITE) != 0)) {
346                         ev_io_stop(event_base, &IO->dns_send_event);
347                 }
348                 IO->dns_send_event.fd = sock;
349                 ev_io_init(&IO->dns_send_event, DNS_send_callback, IO->dns_send_event.fd, EV_WRITE);
350                 IO->dns_send_event.data = IO;
351                 ev_io_start(event_base, &IO->dns_send_event);
352                 IO->active_dns_event = IO->active_dns_event | EV_WRITE;
353         }
354 /*
355
356                 ev_io_start(event_base, &IO->dns_io_event);
357         
358                 maxtv.tv_sec = time/1000;
359                 maxtv.tv_usec = (time % 1000) * 1000;
360                 
361                 ret = ares_timeout(IO->DNSChannel, &maxtv, &tvbuf);
362         }
363 */
364         if ((read == 0) && (write == 0)) {
365                 if ((IO->active_dns_event & EV_READ) != 0)
366                         ev_io_stop(event_base, &IO->dns_recv_event);
367                 if ((IO->active_dns_event & EV_WRITE) != 0)
368                         ev_io_stop(event_base, &IO->dns_send_event);
369                 IO->active_dns_event = 0;
370         }
371 }
372
373 CTDL_MODULE_INIT(c_ares_client)
374 {
375         if (!threading)
376         {
377                 int r = ares_library_init(ARES_LIB_INIT_ALL);
378                 if (0 != r) {
379                         // TODO
380                         // ThrowException(Exception::Error(String::New(ares_strerror(r))));
381 ////                    assert(r == 0);
382                 }
383         }
384         return "c-ares";
385 }