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 | |
7 | License: GPL */ | |
8 | ||
9 | /* Code for calling spf checks via libspf-alt. Called from acl.c. */ | |
10 | ||
11 | #include "exim.h" | |
12 | #ifdef EXPERIMENTAL_SPF | |
13 | ||
14 | /* must be kept in numeric order */ | |
15 | static spf_result_id spf_result_id_list[] = { | |
16 | { US"invalid", 0}, | |
17 | { US"neutral", 1 }, | |
18 | { US"pass", 2 }, | |
19 | { US"fail", 3 }, | |
20 | { US"softfail", 4 }, | |
21 | { US"none", 5 }, | |
22 | { US"err_temp", 6 }, /* Deprecated Apr 2014 */ | |
23 | { US"err_perm", 7 }, /* Deprecated Apr 2014 */ | |
24 | { US"temperror", 6 }, /* RFC 4408 defined */ | |
25 | { US"permerror", 7 } /* RFC 4408 defined */ | |
26 | }; | |
27 | ||
28 | SPF_server_t *spf_server = NULL; | |
29 | SPF_request_t *spf_request = NULL; | |
30 | SPF_response_t *spf_response = NULL; | |
31 | SPF_response_t *spf_response_2mx = NULL; | |
32 | ||
33 | /* spf_init sets up a context that can be re-used for several | |
34 | messages on the same SMTP connection (that come from the | |
35 | same host with the same HELO string) */ | |
36 | ||
37 | int spf_init(uschar *spf_helo_domain, uschar *spf_remote_addr) { | |
38 | ||
39 | spf_server = SPF_server_new(SPF_DNS_CACHE, 0); | |
40 | ||
41 | if ( spf_server == NULL ) { | |
42 | debug_printf("spf: SPF_server_new() failed.\n"); | |
43 | return 0; | |
44 | } | |
45 | ||
46 | if (SPF_server_set_rec_dom(spf_server, CS primary_hostname)) { | |
47 | debug_printf("spf: SPF_server_set_rec_dom(\"%s\") failed.\n", primary_hostname); | |
48 | spf_server = NULL; | |
49 | return 0; | |
50 | } | |
51 | ||
52 | spf_request = SPF_request_new(spf_server); | |
53 | ||
54 | if (SPF_request_set_ipv4_str(spf_request, CS spf_remote_addr) | |
55 | && SPF_request_set_ipv6_str(spf_request, CS spf_remote_addr)) { | |
56 | debug_printf("spf: SPF_request_set_ipv4_str() and SPF_request_set_ipv6_str() failed [%s]\n", spf_remote_addr); | |
57 | spf_server = NULL; | |
58 | spf_request = NULL; | |
59 | return 0; | |
60 | } | |
61 | ||
62 | if (SPF_request_set_helo_dom(spf_request, CS spf_helo_domain)) { | |
63 | debug_printf("spf: SPF_set_helo_dom(\"%s\") failed.\n", spf_helo_domain); | |
64 | spf_server = NULL; | |
65 | spf_request = NULL; | |
66 | return 0; | |
67 | } | |
68 | ||
69 | return 1; | |
70 | } | |
71 | ||
72 | ||
73 | /* spf_process adds the envelope sender address to the existing | |
74 | context (if any), retrieves the result, sets up expansion | |
75 | strings and evaluates the condition outcome. */ | |
76 | ||
77 | int spf_process(uschar **listptr, uschar *spf_envelope_sender, int action) { | |
78 | int sep = 0; | |
79 | uschar *list = *listptr; | |
80 | uschar *spf_result_id; | |
81 | uschar spf_result_id_buffer[128]; | |
82 | int rc = SPF_RESULT_PERMERROR; | |
83 | ||
84 | if (!(spf_server && spf_request)) { | |
85 | /* no global context, assume temp error and skip to evaluation */ | |
86 | rc = SPF_RESULT_PERMERROR; | |
87 | goto SPF_EVALUATE; | |
88 | }; | |
89 | ||
90 | if (SPF_request_set_env_from(spf_request, CS spf_envelope_sender)) { | |
91 | /* Invalid sender address. This should be a real rare occurence */ | |
92 | rc = SPF_RESULT_PERMERROR; | |
93 | goto SPF_EVALUATE; | |
94 | } | |
95 | ||
96 | /* get SPF result */ | |
97 | if (action == SPF_PROCESS_FALLBACK) | |
98 | SPF_request_query_fallback(spf_request, &spf_response, CS spf_guess); | |
99 | else | |
100 | SPF_request_query_mailfrom(spf_request, &spf_response); | |
101 | ||
102 | /* set up expansion items */ | |
103 | spf_header_comment = (uschar *)SPF_response_get_header_comment(spf_response); | |
104 | spf_received = (uschar *)SPF_response_get_received_spf(spf_response); | |
105 | spf_result = (uschar *)SPF_strresult(SPF_response_result(spf_response)); | |
106 | spf_smtp_comment = (uschar *)SPF_response_get_smtp_comment(spf_response); | |
107 | ||
108 | rc = SPF_response_result(spf_response); | |
109 | ||
110 | /* We got a result. Now see if we should return OK or FAIL for it */ | |
111 | SPF_EVALUATE: | |
112 | debug_printf("SPF result is %s (%d)\n", SPF_strresult(rc), rc); | |
113 | ||
114 | if (action == SPF_PROCESS_GUESS && (!strcmp (SPF_strresult(rc), "none"))) | |
115 | return spf_process(listptr, spf_envelope_sender, SPF_PROCESS_FALLBACK); | |
116 | ||
117 | while ((spf_result_id = string_nextinlist(&list, &sep, | |
118 | spf_result_id_buffer, | |
119 | sizeof(spf_result_id_buffer))) != NULL) { | |
120 | int negate = 0; | |
121 | int result = 0; | |
122 | ||
123 | /* Check for negation */ | |
124 | if (spf_result_id[0] == '!') { | |
125 | negate = 1; | |
126 | spf_result_id++; | |
127 | }; | |
128 | ||
129 | /* Check the result identifier */ | |
130 | result = Ustrcmp(spf_result_id, spf_result_id_list[rc].name); | |
131 | if (!negate && result==0) return OK; | |
132 | if (negate && result!=0) return OK; | |
133 | }; | |
134 | ||
135 | /* no match */ | |
136 | return FAIL; | |
137 | } | |
138 | ||
139 | #endif |