1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* Copyright (c) The Exim Maintainers 2020 */
7 /* See the file NOTICE for conditions of use and distribution. */
11 #include "rf_functions.h"
15 /* IP connection types */
21 /* Options specific to the iplookup router. */
23 optionlist iplookup_router_options[] = {
24 { "hosts", opt_stringptr,
25 OPT_OFF(iplookup_router_options_block, hosts) },
26 { "optional", opt_bool,
27 OPT_OFF(iplookup_router_options_block, optional) },
29 OPT_OFF(iplookup_router_options_block, port) },
30 { "protocol", opt_stringptr,
31 OPT_OFF(iplookup_router_options_block, protocol_name) },
32 { "query", opt_stringptr,
33 OPT_OFF(iplookup_router_options_block, query) },
34 { "reroute", opt_stringptr,
35 OPT_OFF(iplookup_router_options_block, reroute) },
36 { "response_pattern", opt_stringptr,
37 OPT_OFF(iplookup_router_options_block, response_pattern) },
38 { "timeout", opt_time,
39 OPT_OFF(iplookup_router_options_block, timeout) }
42 /* Size of the options list. An extern variable has to be used so that its
43 address can appear in the tables drtables.c. */
45 int iplookup_router_options_count =
46 sizeof(iplookup_router_options)/sizeof(optionlist);
52 iplookup_router_options_block iplookup_router_option_defaults = {0};
53 void iplookup_router_init(router_instance *rblock) {}
54 int iplookup_router_entry(router_instance *rblock, address_item *addr,
55 struct passwd *pw, int verify, address_item **addr_local,
56 address_item **addr_remote, address_item **addr_new,
57 address_item **addr_succeed) {return 0;}
59 #else /*!MACRO_PREDEF*/
62 /* Default private options block for the iplookup router. */
64 iplookup_router_options_block iplookup_router_option_defaults = {
66 ip_udp, /* protocol */
68 NULL, /* protocol_name */
70 NULL, /* query; NULL => local_part@domain */
71 NULL, /* response_pattern; NULL => don't apply regex */
72 NULL, /* reroute; NULL => just used returned data */
73 NULL, /* re_response_pattern; compiled pattern */
79 /*************************************************
80 * Initialization entry point *
81 *************************************************/
83 /* Called for each instance, after its options have been read, to enable
84 consistency checks to be done, or anything else that needs to be set up. */
87 iplookup_router_init(router_instance *rblock)
89 iplookup_router_options_block *ob =
90 (iplookup_router_options_block *)(rblock->options_block);
92 /* A port and a host list must be given */
95 log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n "
96 "a port must be specified", rblock->name);
98 if (ob->hosts == NULL)
99 log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n "
100 "a host list must be specified", rblock->name);
102 /* Translate protocol name into value */
104 if (ob->protocol_name != NULL)
106 if (Ustrcmp(ob->protocol_name, "udp") == 0) ob->protocol = ip_udp;
107 else if (Ustrcmp(ob->protocol_name, "tcp") == 0) ob->protocol = ip_tcp;
108 else log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n "
109 "protocol not specified as udp or tcp", rblock->name);
112 /* If a response pattern is given, compile it now to get the error early. */
114 if (ob->response_pattern != NULL)
115 ob->re_response_pattern =
116 regex_must_compile(ob->response_pattern, FALSE, TRUE);
121 /*************************************************
123 *************************************************/
125 /* See local README for interface details. This router returns:
128 . pattern or identification match on returned data failed
131 . failed to expand the query or rerouting string
132 . failed to create socket ("optional" not set)
133 . failed to find a host, failed to connect, timed out ("optional" not set)
134 . rerouting string is not in the form localpart@domain
135 . verifying the errors address caused a deferment or a big disaster such
136 as an expansion failure (rf_get_errors_address)
137 . expanding a headers_{add,remove} string caused a deferment or another
138 expansion error (rf_get_munge_headers)
141 . failed to create socket ("optional" set)
142 . failed to find a host, failed to connect, timed out ("optional" set)
145 . new address added to addr_new
149 iplookup_router_entry(
150 router_instance *rblock, /* data for this instantiation */
151 address_item *addr, /* address we are working on */
152 struct passwd *pw, /* passwd entry after check_local_user */
153 int verify, /* v_none/v_recipient/v_sender/v_expn */
154 address_item **addr_local, /* add it to this if it's local */
155 address_item **addr_remote, /* add it to this if it's remote */
156 address_item **addr_new, /* put new addresses on here */
157 address_item **addr_succeed) /* put old address here on success */
159 uschar *query = NULL;
161 uschar *hostname, *reroute, *domain;
162 const uschar *listptr;
163 uschar host_buffer[256];
164 host_item *host = store_get(sizeof(host_item), FALSE);
165 address_item *new_addr;
166 iplookup_router_options_block *ob =
167 (iplookup_router_options_block *)(rblock->options_block);
168 const pcre *re = ob->re_response_pattern;
169 int count, query_len, rc;
172 DEBUG(D_route) debug_printf("%s router called for %s: domain = %s\n",
173 rblock->name, addr->address, addr->domain);
175 reply = store_get(256, TRUE); /* tainted data */
177 /* Build the query string to send. If not explicitly given, a default of
178 "user@domain user@domain" is used. */
180 if (ob->query == NULL)
181 query = string_sprintf("%s@%s %s@%s", addr->local_part, addr->domain,
182 addr->local_part, addr->domain);
185 query = expand_string(ob->query);
188 addr->message = string_sprintf("%s router: failed to expand %s: %s",
189 rblock->name, ob->query, expand_string_message);
194 query_len = Ustrlen(query);
195 DEBUG(D_route) debug_printf("%s router query is \"%s\"\n", rblock->name,
196 string_printing(query));
198 /* Now connect to the required port for each of the hosts in turn, until a
199 response it received. Initialization insists on the port being set and there
200 being a host list. */
203 while ((hostname = string_nextinlist(&listptr, &sep, host_buffer,
204 sizeof(host_buffer))))
208 DEBUG(D_route) debug_printf("calling host %s\n", hostname);
210 host->name = hostname;
211 host->address = NULL;
212 host->port = PORT_NONE;
216 if (string_is_ip_address(host->name, NULL) != 0)
217 host->address = host->name;
220 /*XXX might want dnssec request/require on an iplookup router? */
221 int rc = host_find_byname(host, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, TRUE);
222 if (rc == HOST_FIND_FAILED || rc == HOST_FIND_AGAIN) continue;
225 /* Loop for possible multiple IP addresses for the given name. */
227 for (h = host; h; h = h->next)
230 client_conn_ctx query_cctx = {0};
232 /* Skip any hosts for which we have no address */
234 if (!h->address) continue;
236 /* Create a socket, for UDP or TCP, as configured. IPv6 addresses are
237 detected by checking for a colon in the address. */
239 host_af = (Ustrchr(h->address, ':') != NULL)? AF_INET6 : AF_INET;
241 query_cctx.sock = ip_socket(ob->protocol == ip_udp ? SOCK_DGRAM:SOCK_STREAM,
243 if (query_cctx.sock < 0)
245 if (ob->optional) return PASS;
246 addr->message = string_sprintf("failed to create socket in %s router",
251 /* Connect to the remote host, under a timeout. In fact, timeouts can occur
252 here only for TCP calls; for a UDP socket, "connect" always works (the
253 router will timeout later on the read call). */
254 /*XXX could take advantage of TFO */
256 if (ip_connect(query_cctx.sock, host_af, h->address,ob->port, ob->timeout,
257 ob->protocol == ip_udp ? NULL : &tcp_fastopen_nodata) < 0)
259 close(query_cctx.sock);
261 debug_printf("connection to %s failed: %s\n", h->address,
266 /* Send the query. If it fails, just continue with the next address. */
268 if (send(query_cctx.sock, query, query_len, 0) < 0)
270 DEBUG(D_route) debug_printf("send to %s failed\n", h->address);
271 (void)close(query_cctx.sock);
275 /* Read the response and close the socket. If the read fails, try the
278 count = ip_recv(&query_cctx, reply, sizeof(reply) - 1, time(NULL) + ob->timeout);
279 (void)close(query_cctx.sock);
282 DEBUG(D_route) debug_printf("%s from %s\n", (errno == ETIMEDOUT)?
283 "timed out" : "recv failed", h->address);
288 /* Success; break the loop */
291 DEBUG(D_route) debug_printf("%s router received \"%s\" from %s\n",
292 rblock->name, string_printing(reply), h->address);
296 /* If h == NULL we have tried all the IP addresses and failed on all of them,
297 so we must continue to try more host names. Otherwise we have succeeded. */
303 /* If hostname is NULL, we have failed to find any host, or failed to
304 connect to any of the IP addresses, or timed out while reading or writing to
305 those we have connected to. In all cases, we must pass if optional and
308 if (hostname == NULL)
310 DEBUG(D_route) debug_printf("%s router failed to get anything\n", rblock->name);
311 if (ob->optional) return PASS;
312 addr->message = string_sprintf("%s router: failed to communicate with any "
313 "host", rblock->name);
318 /* If a response pattern was supplied, match the returned string against it. A
319 failure to match causes the router to decline. After a successful match, the
320 numerical variables for expanding the rerouted address are set up. */
324 if (!regex_match_and_setup(re, reply, 0, -1))
326 DEBUG(D_route) debug_printf("%s router: %s failed to match response %s\n",
327 rblock->name, ob->response_pattern, reply);
333 /* If no response pattern was supplied, set up $0 as the response up to the
334 first white space (if any). Also, if no query was specified, check that what
335 follows the white space matches user@domain. */
340 while (reply[n] != 0 && !isspace(reply[n])) n++;
342 expand_nstring[0] = reply;
343 expand_nlength[0] = n;
345 if (ob->query == NULL)
348 while (isspace(reply[nn])) nn++;
349 if (Ustrcmp(query + query_len/2 + 1, reply+nn) != 0)
351 DEBUG(D_route) debug_printf("%s router: failed to match identification "
352 "in response %s\n", rblock->name, reply);
357 reply[n] = 0; /* Terminate for the default case */
360 /* If an explicit rerouting string is specified, expand it. Otherwise, use
361 what was sent back verbatim. */
363 if (ob->reroute != NULL)
365 reroute = expand_string(ob->reroute);
369 addr->message = string_sprintf("%s router: failed to expand %s: %s",
370 rblock->name, ob->reroute, expand_string_message);
374 else reroute = reply;
376 /* We should now have a new address in the form user@domain. */
378 domain = Ustrchr(reroute, '@');
381 log_write(0, LOG_MAIN, "%s router: reroute string %s is not of the form "
382 "user@domain", rblock->name, reroute);
383 addr->message = string_sprintf("%s router: reroute string %s is not of the "
384 "form user@domain", rblock->name, reroute);
388 /* Create a child address with the old one as parent. Put the new address on
389 the chain of new addressess. */
391 new_addr = deliver_make_addr(reroute, TRUE);
392 new_addr->parent = addr;
394 new_addr->prop = addr->prop;
396 if (addr->child_count == USHRT_MAX)
397 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s router generated more than %d "
398 "child addresses for <%s>", rblock->name, USHRT_MAX, addr->address);
400 new_addr->next = *addr_new;
401 *addr_new = new_addr;
403 /* Set up the errors address, if any, and the additional and removable headers
404 for this new address. */
406 rc = rf_get_errors_address(addr, rblock, verify, &new_addr->prop.errors_address);
407 if (rc != OK) return rc;
409 rc = rf_get_munge_headers(addr, rblock, &new_addr->prop.extra_headers,
410 &new_addr->prop.remove_headers);
411 if (rc != OK) return rc;
416 #endif /*!MACRO_PREDEF*/
417 /* End of routers/iplookup.c */