1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Experimental SPF support.
6 Copyright (c) Tom Kistner <tom@duncanthrax.net> 2004 - 2014
8 Copyright (c) The Exim Maintainers 2016
11 /* Code for calling spf checks via libspf-alt. Called from acl.c. */
14 #ifdef EXPERIMENTAL_SPF
16 /* must be kept in numeric order */
17 static spf_result_id spf_result_id_list
[] = {
24 { US
"err_temp", 6 }, /* Deprecated Apr 2014 */
25 { US
"err_perm", 7 }, /* Deprecated Apr 2014 */
26 { US
"temperror", 6 }, /* RFC 4408 defined */
27 { US
"permerror", 7 } /* RFC 4408 defined */
30 SPF_server_t
*spf_server
= NULL
;
31 SPF_request_t
*spf_request
= NULL
;
32 SPF_response_t
*spf_response
= NULL
;
33 SPF_response_t
*spf_response_2mx
= NULL
;
35 /* spf_init sets up a context that can be re-used for several
36 messages on the same SMTP connection (that come from the
37 same host with the same HELO string) */
39 int spf_init(uschar
*spf_helo_domain
, uschar
*spf_remote_addr
) {
41 spf_server
= SPF_server_new(SPF_DNS_CACHE
, 0);
43 if ( spf_server
== NULL
) {
44 debug_printf("spf: SPF_server_new() failed.\n");
48 if (SPF_server_set_rec_dom(spf_server
, CS primary_hostname
)) {
49 debug_printf("spf: SPF_server_set_rec_dom(\"%s\") failed.\n", primary_hostname
);
54 spf_request
= SPF_request_new(spf_server
);
56 if (SPF_request_set_ipv4_str(spf_request
, CS spf_remote_addr
)
57 && SPF_request_set_ipv6_str(spf_request
, CS spf_remote_addr
)) {
58 debug_printf("spf: SPF_request_set_ipv4_str() and SPF_request_set_ipv6_str() failed [%s]\n", spf_remote_addr
);
64 if (SPF_request_set_helo_dom(spf_request
, CS spf_helo_domain
)) {
65 debug_printf("spf: SPF_set_helo_dom(\"%s\") failed.\n", spf_helo_domain
);
75 /* spf_process adds the envelope sender address to the existing
76 context (if any), retrieves the result, sets up expansion
77 strings and evaluates the condition outcome. */
79 int spf_process(const uschar
**listptr
, uschar
*spf_envelope_sender
, int action
) {
81 const uschar
*list
= *listptr
;
82 uschar
*spf_result_id
;
83 uschar spf_result_id_buffer
[128];
84 int rc
= SPF_RESULT_PERMERROR
;
86 if (!(spf_server
&& spf_request
)) {
87 /* no global context, assume temp error and skip to evaluation */
88 rc
= SPF_RESULT_PERMERROR
;
92 if (SPF_request_set_env_from(spf_request
, CS spf_envelope_sender
)) {
93 /* Invalid sender address. This should be a real rare occurence */
94 rc
= SPF_RESULT_PERMERROR
;
99 if (action
== SPF_PROCESS_FALLBACK
)
100 SPF_request_query_fallback(spf_request
, &spf_response
, CS spf_guess
);
102 SPF_request_query_mailfrom(spf_request
, &spf_response
);
104 /* set up expansion items */
105 spf_header_comment
= (uschar
*)SPF_response_get_header_comment(spf_response
);
106 spf_received
= (uschar
*)SPF_response_get_received_spf(spf_response
);
107 spf_result
= (uschar
*)SPF_strresult(SPF_response_result(spf_response
));
108 spf_smtp_comment
= (uschar
*)SPF_response_get_smtp_comment(spf_response
);
110 rc
= SPF_response_result(spf_response
);
112 /* We got a result. Now see if we should return OK or FAIL for it */
114 debug_printf("SPF result is %s (%d)\n", SPF_strresult(rc
), rc
);
116 if (action
== SPF_PROCESS_GUESS
&& (!strcmp (SPF_strresult(rc
), "none")))
117 return spf_process(listptr
, spf_envelope_sender
, SPF_PROCESS_FALLBACK
);
119 while ((spf_result_id
= string_nextinlist(&list
, &sep
,
120 spf_result_id_buffer
,
121 sizeof(spf_result_id_buffer
))) != NULL
) {
125 /* Check for negation */
126 if (spf_result_id
[0] == '!') {
131 /* Check the result identifier */
132 result
= Ustrcmp(spf_result_id
, spf_result_id_list
[rc
].name
);
133 if (!negate
&& result
==0) return OK
;
134 if (negate
&& result
!=0) return OK
;