Commit | Line | Data |
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420a0d19 CE |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
5 | /* Experimental SPF support. | |
6 | Copyright (c) Tom Kistner <tom@duncanthrax.net> 2004 - 2014 | |
2813c06e CE |
7 | License: GPL |
8 | Copyright (c) The Exim Maintainers 2016 | |
9 | */ | |
420a0d19 CE |
10 | |
11 | /* Code for calling spf checks via libspf-alt. Called from acl.c. */ | |
12 | ||
13 | #include "exim.h" | |
14 | #ifdef EXPERIMENTAL_SPF | |
15 | ||
16 | /* must be kept in numeric order */ | |
17 | static spf_result_id spf_result_id_list[] = { | |
18 | { US"invalid", 0}, | |
19 | { US"neutral", 1 }, | |
20 | { US"pass", 2 }, | |
21 | { US"fail", 3 }, | |
22 | { US"softfail", 4 }, | |
23 | { US"none", 5 }, | |
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 */ | |
28 | }; | |
29 | ||
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; | |
34 | ||
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) */ | |
38 | ||
39 | int spf_init(uschar *spf_helo_domain, uschar *spf_remote_addr) { | |
40 | ||
41 | spf_server = SPF_server_new(SPF_DNS_CACHE, 0); | |
42 | ||
43 | if ( spf_server == NULL ) { | |
44 | debug_printf("spf: SPF_server_new() failed.\n"); | |
45 | return 0; | |
46 | } | |
47 | ||
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); | |
50 | spf_server = NULL; | |
51 | return 0; | |
52 | } | |
53 | ||
54 | spf_request = SPF_request_new(spf_server); | |
55 | ||
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); | |
59 | spf_server = NULL; | |
60 | spf_request = NULL; | |
61 | return 0; | |
62 | } | |
63 | ||
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); | |
66 | spf_server = NULL; | |
67 | spf_request = NULL; | |
68 | return 0; | |
69 | } | |
70 | ||
71 | return 1; | |
72 | } | |
73 | ||
74 | ||
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. */ | |
78 | ||
2813c06e | 79 | int spf_process(const uschar **listptr, uschar *spf_envelope_sender, int action) { |
420a0d19 | 80 | int sep = 0; |
2813c06e | 81 | const uschar *list = *listptr; |
420a0d19 CE |
82 | uschar *spf_result_id; |
83 | uschar spf_result_id_buffer[128]; | |
84 | int rc = SPF_RESULT_PERMERROR; | |
85 | ||
86 | if (!(spf_server && spf_request)) { | |
87 | /* no global context, assume temp error and skip to evaluation */ | |
88 | rc = SPF_RESULT_PERMERROR; | |
89 | goto SPF_EVALUATE; | |
90 | }; | |
91 | ||
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; | |
95 | goto SPF_EVALUATE; | |
96 | } | |
97 | ||
98 | /* get SPF result */ | |
99 | if (action == SPF_PROCESS_FALLBACK) | |
100 | SPF_request_query_fallback(spf_request, &spf_response, CS spf_guess); | |
101 | else | |
102 | SPF_request_query_mailfrom(spf_request, &spf_response); | |
103 | ||
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); | |
109 | ||
110 | rc = SPF_response_result(spf_response); | |
111 | ||
112 | /* We got a result. Now see if we should return OK or FAIL for it */ | |
113 | SPF_EVALUATE: | |
114 | debug_printf("SPF result is %s (%d)\n", SPF_strresult(rc), rc); | |
115 | ||
116 | if (action == SPF_PROCESS_GUESS && (!strcmp (SPF_strresult(rc), "none"))) | |
117 | return spf_process(listptr, spf_envelope_sender, SPF_PROCESS_FALLBACK); | |
118 | ||
119 | while ((spf_result_id = string_nextinlist(&list, &sep, | |
120 | spf_result_id_buffer, | |
121 | sizeof(spf_result_id_buffer))) != NULL) { | |
122 | int negate = 0; | |
123 | int result = 0; | |
124 | ||
125 | /* Check for negation */ | |
126 | if (spf_result_id[0] == '!') { | |
127 | negate = 1; | |
128 | spf_result_id++; | |
129 | }; | |
130 | ||
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; | |
135 | }; | |
136 | ||
137 | /* no match */ | |
138 | return FAIL; | |
139 | } | |
140 | ||
141 | #endif |