ff67af38dd8b512832ee8c1aca559829533e3379
[exim.git] / src / src / routers / iplookup.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
8
9 #include "../exim.h"
10 #include "rf_functions.h"
11 #include "iplookup.h"
12
13
14 /* IP connection types */
15
16 #define ip_udp 0
17 #define ip_tcp 1
18
19
20 /* Options specific to the iplookup router. */
21
22 optionlist iplookup_router_options[] = {
23 { "hosts", opt_stringptr,
24 (void *)(offsetof(iplookup_router_options_block, hosts)) },
25 { "optional", opt_bool,
26 (void *)(offsetof(iplookup_router_options_block, optional)) },
27 { "port", opt_int,
28 (void *)(offsetof(iplookup_router_options_block, port)) },
29 { "protocol", opt_stringptr,
30 (void *)(offsetof(iplookup_router_options_block, protocol_name)) },
31 { "query", opt_stringptr,
32 (void *)(offsetof(iplookup_router_options_block, query)) },
33 { "reroute", opt_stringptr,
34 (void *)(offsetof(iplookup_router_options_block, reroute)) },
35 { "response_pattern", opt_stringptr,
36 (void *)(offsetof(iplookup_router_options_block, response_pattern)) },
37 { "timeout", opt_time,
38 (void *)(offsetof(iplookup_router_options_block, timeout)) }
39 };
40
41 /* Size of the options list. An extern variable has to be used so that its
42 address can appear in the tables drtables.c. */
43
44 int iplookup_router_options_count =
45 sizeof(iplookup_router_options)/sizeof(optionlist);
46
47
48 #ifdef MACRO_PREDEF
49
50 /* Dummy entries */
51 iplookup_router_options_block iplookup_router_option_defaults = {0};
52 void iplookup_router_init(router_instance *rblock) {}
53 int iplookup_router_entry(router_instance *rblock, address_item *addr,
54 struct passwd *pw, int verify, address_item **addr_local,
55 address_item **addr_remote, address_item **addr_new,
56 address_item **addr_succeed) {return 0;}
57
58 #else /*!MACRO_PREDEF*/
59
60
61 /* Default private options block for the iplookup router. */
62
63 iplookup_router_options_block iplookup_router_option_defaults = {
64 -1, /* port */
65 ip_udp, /* protocol */
66 5, /* timeout */
67 NULL, /* protocol_name */
68 NULL, /* hosts */
69 NULL, /* query; NULL => local_part@domain */
70 NULL, /* response_pattern; NULL => don't apply regex */
71 NULL, /* reroute; NULL => just used returned data */
72 NULL, /* re_response_pattern; compiled pattern */
73 FALSE /* optional */
74 };
75
76
77
78 /*************************************************
79 * Initialization entry point *
80 *************************************************/
81
82 /* Called for each instance, after its options have been read, to enable
83 consistency checks to be done, or anything else that needs to be set up. */
84
85 void
86 iplookup_router_init(router_instance *rblock)
87 {
88 iplookup_router_options_block *ob =
89 (iplookup_router_options_block *)(rblock->options_block);
90
91 /* A port and a host list must be given */
92
93 if (ob->port < 0)
94 log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n "
95 "a port must be specified", rblock->name);
96
97 if (ob->hosts == NULL)
98 log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n "
99 "a host list must be specified", rblock->name);
100
101 /* Translate protocol name into value */
102
103 if (ob->protocol_name != NULL)
104 {
105 if (Ustrcmp(ob->protocol_name, "udp") == 0) ob->protocol = ip_udp;
106 else if (Ustrcmp(ob->protocol_name, "tcp") == 0) ob->protocol = ip_tcp;
107 else log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n "
108 "protocol not specified as udp or tcp", rblock->name);
109 }
110
111 /* If a response pattern is given, compile it now to get the error early. */
112
113 if (ob->response_pattern != NULL)
114 ob->re_response_pattern =
115 regex_must_compile(ob->response_pattern, FALSE, TRUE);
116 }
117
118
119
120 /*************************************************
121 * Main entry point *
122 *************************************************/
123
124 /* See local README for interface details. This router returns:
125
126 DECLINE
127 . pattern or identification match on returned data failed
128
129 DEFER
130 . failed to expand the query or rerouting string
131 . failed to create socket ("optional" not set)
132 . failed to find a host, failed to connect, timed out ("optional" not set)
133 . rerouting string is not in the form localpart@domain
134 . verifying the errors address caused a deferment or a big disaster such
135 as an expansion failure (rf_get_errors_address)
136 . expanding a headers_{add,remove} string caused a deferment or another
137 expansion error (rf_get_munge_headers)
138
139 PASS
140 . failed to create socket ("optional" set)
141 . failed to find a host, failed to connect, timed out ("optional" set)
142
143 OK
144 . new address added to addr_new
145 */
146
147 int
148 iplookup_router_entry(
149 router_instance *rblock, /* data for this instantiation */
150 address_item *addr, /* address we are working on */
151 struct passwd *pw, /* passwd entry after check_local_user */
152 int verify, /* v_none/v_recipient/v_sender/v_expn */
153 address_item **addr_local, /* add it to this if it's local */
154 address_item **addr_remote, /* add it to this if it's remote */
155 address_item **addr_new, /* put new addresses on here */
156 address_item **addr_succeed) /* put old address here on success */
157 {
158 uschar *query = NULL;
159 uschar *reply;
160 uschar *hostname, *reroute, *domain;
161 const uschar *listptr;
162 uschar host_buffer[256];
163 host_item *host = store_get(sizeof(host_item));
164 address_item *new_addr;
165 iplookup_router_options_block *ob =
166 (iplookup_router_options_block *)(rblock->options_block);
167 const pcre *re = ob->re_response_pattern;
168 int count, query_len, rc;
169 int sep = 0;
170
171 addr_local = addr_local; /* Keep picky compilers happy */
172 addr_remote = addr_remote;
173 addr_succeed = addr_succeed;
174 pw = pw;
175
176 DEBUG(D_route) debug_printf("%s router called for %s: domain = %s\n",
177 rblock->name, addr->address, addr->domain);
178
179 reply = store_get(256);
180
181 /* Build the query string to send. If not explicitly given, a default of
182 "user@domain user@domain" is used. */
183
184 if (ob->query == NULL)
185 query = string_sprintf("%s@%s %s@%s", addr->local_part, addr->domain,
186 addr->local_part, addr->domain);
187 else
188 {
189 query = expand_string(ob->query);
190 if (query == NULL)
191 {
192 addr->message = string_sprintf("%s router: failed to expand %s: %s",
193 rblock->name, ob->query, expand_string_message);
194 return DEFER;
195 }
196 }
197
198 query_len = Ustrlen(query);
199 DEBUG(D_route) debug_printf("%s router query is \"%s\"\n", rblock->name,
200 string_printing(query));
201
202 /* Now connect to the required port for each of the hosts in turn, until a
203 response it received. Initialization insists on the port being set and there
204 being a host list. */
205
206 listptr = ob->hosts;
207 while ((hostname = string_nextinlist(&listptr, &sep, host_buffer,
208 sizeof(host_buffer))))
209 {
210 host_item *h;
211
212 DEBUG(D_route) debug_printf("calling host %s\n", hostname);
213
214 host->name = hostname;
215 host->address = NULL;
216 host->port = PORT_NONE;
217 host->mx = MX_NONE;
218 host->next = NULL;
219
220 if (string_is_ip_address(host->name, NULL) != 0)
221 host->address = host->name;
222 else
223 {
224 /*XXX might want dnssec request/require on an iplookup router? */
225 int rc = host_find_byname(host, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, TRUE);
226 if (rc == HOST_FIND_FAILED || rc == HOST_FIND_AGAIN) continue;
227 }
228
229 /* Loop for possible multiple IP addresses for the given name. */
230
231 for (h = host; h; h = h->next)
232 {
233 int host_af;
234 client_conn_ctx query_cctx = {0};
235
236 /* Skip any hosts for which we have no address */
237
238 if (!h->address) continue;
239
240 /* Create a socket, for UDP or TCP, as configured. IPv6 addresses are
241 detected by checking for a colon in the address. */
242
243 host_af = (Ustrchr(h->address, ':') != NULL)? AF_INET6 : AF_INET;
244
245 query_cctx.sock = ip_socket(ob->protocol == ip_udp ? SOCK_DGRAM:SOCK_STREAM,
246 host_af);
247 if (query_cctx.sock < 0)
248 {
249 if (ob->optional) return PASS;
250 addr->message = string_sprintf("failed to create socket in %s router",
251 rblock->name);
252 return DEFER;
253 }
254
255 /* Connect to the remote host, under a timeout. In fact, timeouts can occur
256 here only for TCP calls; for a UDP socket, "connect" always works (the
257 router will timeout later on the read call). */
258 /*XXX could take advantage of TFO */
259
260 if (ip_connect(query_cctx.sock, host_af, h->address,ob->port, ob->timeout,
261 ob->protocol == ip_udp ? NULL : &tcp_fastopen_nodata) < 0)
262 {
263 close(query_cctx.sock);
264 DEBUG(D_route)
265 debug_printf("connection to %s failed: %s\n", h->address,
266 strerror(errno));
267 continue;
268 }
269
270 /* Send the query. If it fails, just continue with the next address. */
271
272 if (send(query_cctx.sock, query, query_len, 0) < 0)
273 {
274 DEBUG(D_route) debug_printf("send to %s failed\n", h->address);
275 (void)close(query_cctx.sock);
276 continue;
277 }
278
279 /* Read the response and close the socket. If the read fails, try the
280 next IP address. */
281
282 count = ip_recv(&query_cctx, reply, sizeof(reply) - 1, ob->timeout);
283 (void)close(query_cctx.sock);
284 if (count <= 0)
285 {
286 DEBUG(D_route) debug_printf("%s from %s\n", (errno == ETIMEDOUT)?
287 "timed out" : "recv failed", h->address);
288 *reply = 0;
289 continue;
290 }
291
292 /* Success; break the loop */
293
294 reply[count] = 0;
295 DEBUG(D_route) debug_printf("%s router received \"%s\" from %s\n",
296 rblock->name, string_printing(reply), h->address);
297 break;
298 }
299
300 /* If h == NULL we have tried all the IP addresses and failed on all of them,
301 so we must continue to try more host names. Otherwise we have succeeded. */
302
303 if (h) break;
304 }
305
306
307 /* If hostname is NULL, we have failed to find any host, or failed to
308 connect to any of the IP addresses, or timed out while reading or writing to
309 those we have connected to. In all cases, we must pass if optional and
310 defer otherwise. */
311
312 if (hostname == NULL)
313 {
314 DEBUG(D_route) debug_printf("%s router failed to get anything\n", rblock->name);
315 if (ob->optional) return PASS;
316 addr->message = string_sprintf("%s router: failed to communicate with any "
317 "host", rblock->name);
318 return DEFER;
319 }
320
321
322 /* If a response pattern was supplied, match the returned string against it. A
323 failure to match causes the router to decline. After a successful match, the
324 numerical variables for expanding the rerouted address are set up. */
325
326 if (re != NULL)
327 {
328 if (!regex_match_and_setup(re, reply, 0, -1))
329 {
330 DEBUG(D_route) debug_printf("%s router: %s failed to match response %s\n",
331 rblock->name, ob->response_pattern, reply);
332 return DECLINE;
333 }
334 }
335
336
337 /* If no response pattern was supplied, set up $0 as the response up to the
338 first white space (if any). Also, if no query was specified, check that what
339 follows the white space matches user@domain. */
340
341 else
342 {
343 int n = 0;
344 while (reply[n] != 0 && !isspace(reply[n])) n++;
345 expand_nmax = 0;
346 expand_nstring[0] = reply;
347 expand_nlength[0] = n;
348
349 if (ob->query == NULL)
350 {
351 int nn = n;
352 while (isspace(reply[nn])) nn++;
353 if (Ustrcmp(query + query_len/2 + 1, reply+nn) != 0)
354 {
355 DEBUG(D_route) debug_printf("%s router: failed to match identification "
356 "in response %s\n", rblock->name, reply);
357 return DECLINE;
358 }
359 }
360
361 reply[n] = 0; /* Terminate for the default case */
362 }
363
364 /* If an explicit rerouting string is specified, expand it. Otherwise, use
365 what was sent back verbatim. */
366
367 if (ob->reroute != NULL)
368 {
369 reroute = expand_string(ob->reroute);
370 expand_nmax = -1;
371 if (reroute == NULL)
372 {
373 addr->message = string_sprintf("%s router: failed to expand %s: %s",
374 rblock->name, ob->reroute, expand_string_message);
375 return DEFER;
376 }
377 }
378 else reroute = reply;
379
380 /* We should now have a new address in the form user@domain. */
381
382 domain = Ustrchr(reroute, '@');
383 if (domain == NULL)
384 {
385 log_write(0, LOG_MAIN, "%s router: reroute string %s is not of the form "
386 "user@domain", rblock->name, reroute);
387 addr->message = string_sprintf("%s router: reroute string %s is not of the "
388 "form user@domain", rblock->name, reroute);
389 return DEFER;
390 }
391
392 /* Create a child address with the old one as parent. Put the new address on
393 the chain of new addressess. */
394
395 new_addr = deliver_make_addr(reroute, TRUE);
396 new_addr->parent = addr;
397
398 new_addr->prop = addr->prop;
399
400 if (addr->child_count == USHRT_MAX)
401 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s router generated more than %d "
402 "child addresses for <%s>", rblock->name, USHRT_MAX, addr->address);
403 addr->child_count++;
404 new_addr->next = *addr_new;
405 *addr_new = new_addr;
406
407 /* Set up the errors address, if any, and the additional and removable headers
408 for this new address. */
409
410 rc = rf_get_errors_address(addr, rblock, verify, &new_addr->prop.errors_address);
411 if (rc != OK) return rc;
412
413 rc = rf_get_munge_headers(addr, rblock, &new_addr->prop.extra_headers,
414 &new_addr->prop.remove_headers);
415 if (rc != OK) return rc;
416
417 return OK;
418 }
419
420 #endif /*!MACRO_PREDEF*/
421 /* End of routers/iplookup.c */