Testsuite: followon -bt output changes
[exim.git] / src / src / routers / rf_lookup_hostlist.c
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1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
3386088d 5/* Copyright (c) University of Cambridge 1995 - 2015 */
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6/* See the file NOTICE for conditions of use and distribution. */
7
8
9#include "../exim.h"
10#include "rf_functions.h"
11
12
13
14/*************************************************
15* Look up IP addresses for a set of hosts *
16*************************************************/
17
18/* This function is called by a router to fill in the IP addresses for a set of
19hosts that are attached to an address. Each host has its name and MX value set;
20and those that need processing have their address fields set NULL. Multihomed
21hosts cause additional blocks to be inserted into the chain.
22
23This function also supports pseudo-hosts whose names end with "/MX". In this
24case, MX records are looked up for the name, and the list of hosts obtained
25replaces the incoming "host". In other words, "x/MX" is shorthand for "those
26hosts pointed to by x's MX records".
27
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28It is also possible for a port to be specified along with the host name or IP
29address. The syntax is to add ":port" on to the end. This doesn't work with
30IPv6 addresses, so we allow IP addresses to be enclosed in [] in order to make
31this work. The specification of the port must come last, that is, after "/MX"
32if that is present.
33
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34Arguments:
35 rblock the router block
36 addr the address being routed
37 ignore_target_hosts list of hosts to ignore
38 lookup_type lk_default or lk_byname or lk_bydns
39 hff_code what to do for host find failed
40 addr_new passed to rf_self_action for self=reroute
41
42Returns: OK
43 DEFER host lookup defer
44 PASS timeout etc and pass_on_timeout set
45 self_action: PASS, DECLINE, DEFER, FAIL, FREEZE
46 hff_code after host find failed
47*/
48
49int
50rf_lookup_hostlist(router_instance *rblock, address_item *addr,
51 uschar *ignore_target_hosts, int lookup_type, int hff_code,
52 address_item **addr_new)
53{
54BOOL self_send = FALSE;
55host_item *h, *next_h, *prev;
56
57/* Look up each host address. A lookup may add additional items into the chain
58if there are multiple addresses. Hence the use of next_h to start each cycle of
59the loop at the next original host. If any host is identified as being the local
60host, omit it and any subsequent hosts - i.e. treat the list like an ordered
61list of MX hosts. If the first host is the local host, act according to the
62"self" option in the configuration. */
63
64prev = NULL;
cd9868ec 65for (h = addr->host_list; h != NULL; h = next_h)
0756eb3c 66 {
55414b25 67 const uschar *canonical_name;
7cd1141b 68 int rc, len, port;
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69
70 next_h = h->next;
cd9868ec 71 if (h->address != NULL) { prev = h; continue; }
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72
73 DEBUG(D_route|D_host_lookup)
74 debug_printf("finding IP address for %s\n", h->name);
75
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76 /* Handle any port setting that may be on the name; it will be removed
77 from the end of the name. */
78
79 port = host_item_get_port(h);
80
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81 /* If the name ends with "/MX", we interpret it to mean "the list of hosts
82 pointed to by MX records with this name". */
83
84 len = Ustrlen(h->name);
85 if (len > 3 && strcmpic(h->name + len - 3, US"/mx") == 0)
86 {
87 DEBUG(D_route|D_host_lookup)
88 debug_printf("doing DNS MX lookup for %s\n", h->name);
89
7cd1141b 90 h->name = string_copyn(h->name, len - 3);
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91 rc = host_find_bydns(h,
92 ignore_target_hosts,
93 HOST_FIND_BY_MX, /* look only for MX records */
94 NULL, /* SRV service not relevant */
95 NULL, /* failing srv domains not relevant */
96 NULL, /* no special mx failing domains */
7cd171b7 97 &rblock->dnssec, /* dnssec request/require */
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98 NULL, /* fully_qualified_name */
99 NULL); /* indicate local host removed */
100 }
101
102 /* If explicitly configured to look up by name, or if the "host name" is
103 actually an IP address, do a byname lookup. */
104
7e66e54d 105 else if (lookup_type == lk_byname || string_is_ip_address(h->name, NULL) != 0)
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106 {
107 DEBUG(D_route|D_host_lookup) debug_printf("calling host_find_byname\n");
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108 rc = host_find_byname(h, ignore_target_hosts, HOST_FIND_QUALIFY_SINGLE,
109 &canonical_name, TRUE);
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110 }
111
112 /* Otherwise, do a DNS lookup. If that yields "host not found", and the
113 lookup type is the default (i.e. "bydns" is not explicitly configured),
114 follow up with a byname lookup, just in case. */
115
116 else
117 {
118 BOOL removed;
119 DEBUG(D_route|D_host_lookup) debug_printf("doing DNS lookup\n");
120 rc = host_find_bydns(h, ignore_target_hosts, HOST_FIND_BY_A, NULL, NULL,
8c51eead 121 NULL,
7cd171b7 122 &rblock->dnssec, /* domains for request/require */
8c51eead 123 &canonical_name, &removed);
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124 if (rc == HOST_FOUND)
125 {
126 if (removed) setflag(addr, af_local_host_removed);
127 }
128 else if (rc == HOST_FIND_FAILED)
129 {
130 if (lookup_type == lk_default)
131 {
132 DEBUG(D_route|D_host_lookup)
133 debug_printf("DNS lookup failed: trying getipnodebyname\n");
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134 rc = host_find_byname(h, ignore_target_hosts, HOST_FIND_QUALIFY_SINGLE,
135 &canonical_name, TRUE);
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136 }
137 }
138 }
139
140 /* Temporary failure defers, unless pass_on_timeout is set */
141
142 if (rc == HOST_FIND_AGAIN)
143 {
144 if (rblock->pass_on_timeout)
145 {
146 DEBUG(D_route)
147 debug_printf("%s router timed out and pass_on_timeout set\n",
148 rblock->name);
149 return PASS;
150 }
151 addr->message = string_sprintf("host lookup for %s did not complete "
152 "(DNS timeout?)", h->name);
153 addr->basic_errno = ERRNO_DNSDEFER;
154 return DEFER;
155 }
156
157 /* Permanent failure is controlled by host_find_failed */
158
159 if (rc == HOST_FIND_FAILED)
160 {
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161 if (hff_code == hff_ignore)
162 {
163 if (prev == NULL) addr->host_list = next_h; else prev->next = next_h;
cd9868ec 164 continue; /* With the next host, leave prev unchanged */
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165 }
166
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167 if (hff_code == hff_pass) return PASS;
168 if (hff_code == hff_decline) return DECLINE;
169
bd4ece7d 170 addr->basic_errno = ERRNO_UNKNOWNHOST;
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171 addr->message =
172 string_sprintf("lookup of host \"%s\" failed in %s router%s",
173 h->name, rblock->name,
174 host_find_failed_syntax? ": syntax error in name" : "");
175
176 if (hff_code == hff_defer) return DEFER;
177 if (hff_code == hff_fail) return FAIL;
178
179 addr->special_action = SPECIAL_FREEZE;
180 return DEFER;
181 }
182
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183 /* Deal with a port setting */
184
185 if (port != PORT_NONE)
186 {
187 host_item *hh;
188 for (hh = h; hh != next_h; hh = hh->next) hh->port = port;
189 }
190
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191 /* A local host gets chopped, with its successors, if there are previous
192 hosts. Otherwise the self option is used. If it is set to "send", any
193 subsequent hosts that are also the local host do NOT get chopped. */
194
195 if (rc == HOST_FOUND_LOCAL && !self_send)
196 {
197 if (prev != NULL)
198 {
199 DEBUG(D_route)
200 {
201 debug_printf("Removed from host list:\n");
202 for (; h != NULL; h = h->next) debug_printf(" %s\n", h->name);
203 }
204 prev->next = NULL;
205 setflag(addr, af_local_host_removed);
206 break;
207 }
208 rc = rf_self_action(addr, h, rblock->self_code, rblock->self_rewrite,
209 rblock->self, addr_new);
210 if (rc != OK)
211 {
212 addr->host_list = NULL; /* Kill the host list for */
213 return rc; /* anything other than "send" */
214 }
215 self_send = TRUE;
216 }
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217
218 /* Ensure that prev is the host before next_h; this will not be h if a lookup
219 found multiple addresses or multiple MX records. */
220
221 prev = h;
222 while (prev->next != next_h) prev = prev->next;
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223 }
224
225return OK;
226}
227
228/* End of rf_lookup_hostlist.c */