X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/4533e306fc21e0dc3cce32db0e2bfa146a5dd78c..92583637b25b6bde926f9ca6be7b085e5ac8b1e6:/src/src/spf.c diff --git a/src/src/spf.c b/src/src/spf.c index 3ca289656..2f55fb77c 100644 --- a/src/src/spf.c +++ b/src/src/spf.c @@ -5,7 +5,7 @@ /* SPF support. Copyright (c) Tom Kistner 2004 - 2014 License: GPL - Copyright (c) The Exim Maintainers 2015 - 2019 + Copyright (c) The Exim Maintainers 2015 - 2020 */ /* Code for calling spf checks via libspf-alt. Called from acl.c. */ @@ -34,10 +34,22 @@ SPF_response_t *spf_response_2mx = NULL; SPF_dns_rr_t * spf_nxdomain = NULL; +void +spf_lib_version_report(FILE * fp) +{ +int maj, min, patch; +SPF_get_lib_version(&maj, &min, &patch); +fprintf(fp, "Library version: spf2: Compile: %d.%d.%d\n", + SPF_LIB_VERSION_MAJOR, SPF_LIB_VERSION_MINOR, SPF_LIB_VERSION_PATCH); +fprintf(fp, " Runtime: %d.%d.%d\n", + maj, min, patch); +} + + static SPF_dns_rr_t * SPF_dns_exim_lookup(SPF_dns_server_t *spf_dns_server, -const char *domain, ns_type rr_type, int should_cache) + const char *domain, ns_type rr_type, int should_cache) { dns_answer * dnsa = store_get_dns_answer(); dns_scan dnss; @@ -56,22 +68,44 @@ SPF_dns_rr_t srr = { .hook = NULL, /* misc information */ .source = spf_dns_server }; +int dns_rc; DEBUG(D_receive) debug_printf("SPF_dns_exim_lookup '%s'\n", domain); -if (dns_lookup(dnsa, US domain, rr_type, NULL) == DNS_NOMATCH) +/* Shortcircuit SPF RR lookups by returning NO_DATA. They were obsoleted by +RFC 6686/7208 years ago. see bug #1294 */ + +if (rr_type == T_SPF) { - SPF_dns_rr_dup(&spfrr, spf_nxdomain); + HDEBUG(D_host_lookup) debug_printf("faking NO_DATA for SPF RR(99) lookup\n"); + srr.herrno = NO_DATA; + SPF_dns_rr_dup(&spfrr, &srr); + store_free_dns_answer(dnsa); return spfrr; -} + } + +switch (dns_rc = dns_lookup(dnsa, US domain, rr_type, NULL)) + { + case DNS_SUCCEED: srr.herrno = NETDB_SUCCESS; break; + case DNS_AGAIN: srr.herrno = TRY_AGAIN; break; + case DNS_NOMATCH: srr.herrno = HOST_NOT_FOUND; break; + case DNS_NODATA: srr.herrno = NO_DATA; break; + case DNS_FAIL: + default: srr.herrno = NO_RECOVERY; break; + } for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) if (rr->type == rr_type) found++; -srr.num_rr = found; +if (found == 0) + { + SPF_dns_rr_dup(&spfrr, &srr); + store_free_dns_answer(dnsa); + return spfrr; + } + srr.rr = store_malloc(sizeof(SPF_dns_rr_data_t) * found); -srr.herrno = h_errno, found = 0; for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; @@ -84,7 +118,7 @@ for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; switch(rr_type) { case T_MX: - s += 2; /* skip the MX precedence field */ + s += 2; /* skip the MX precedence field */ case T_PTR: { uschar * buf = store_malloc(256); @@ -99,9 +133,10 @@ for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; gstring * g = NULL; uschar chunk_len; - if (strncmpic(rr->data+1, US"v=spf1", 6) != 0) + if (strncmpic(rr->data+1, US SPF_VER_STR, 6) != 0) { - HDEBUG(D_host_lookup) debug_printf("not an spf record\n"); + HDEBUG(D_host_lookup) debug_printf("not an spf record: %.*s\n", + (int) s[0], s+1); continue; } @@ -114,6 +149,7 @@ for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; continue; gstring_release_unused(g); s = string_copy_malloc(string_from_gstring(g)); + DEBUG(D_receive) debug_printf("SPF_dns_exim_lookup '%s'\n", s); break; } @@ -126,12 +162,18 @@ for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; break; } } - DEBUG(D_receive) debug_printf("SPF_dns_exim_lookup '%s'\n", s); srr.rr[found++] = (void *) s; } +/* Did we filter out all TXT RRs? Return NO_DATA instead of SUCCESS with +empty ANSWER section. */ + +if (!(srr.num_rr = found)) + srr.herrno = NO_DATA; + /* spfrr->rr must have been malloc()d for this */ SPF_dns_rr_dup(&spfrr, &srr); +store_free_dns_answer(dnsa); return spfrr; } @@ -179,6 +221,7 @@ spf_init(void) { SPF_dns_server_t * dc; int debug = 0; +const uschar *s; DEBUG(D_receive) debug = 1; @@ -201,11 +244,16 @@ if (!(spf_server = SPF_server_new_dns(dc, debug))) DEBUG(D_receive) debug_printf("spf: SPF_server_new() failed.\n"); return FALSE; } - /* Quick hack to override the outdated explanation URL. - See https://www.mail-archive.com/mailop@mailop.org/msg08019.html */ - SPF_server_set_explanation(spf_server, "Please%_see%_http://www.open-spf.org/Why?id=%{S}&ip=%{C}&receiver=%{R}", &spf_response); - if (SPF_response_errcode(spf_response) != SPF_E_SUCCESS) - log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", SPF_strerror(SPF_response_errcode(spf_response))); + /* Override the outdated explanation URL. + See https://www.mail-archive.com/mailop@mailop.org/msg08019.html + Used to work as "Please%_see%_http://www.open-spf.org/Why?id=%{S}&ip=%{C}&receiver=%{R}", + but is broken now (May 18th, 2020) */ +if (!(s = expand_string(spf_smtp_comment_template))) + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "expansion of spf_smtp_comment_template failed"); + +SPF_server_set_explanation(spf_server, CCS s, &spf_response); +if (SPF_response_errcode(spf_response) != SPF_E_SUCCESS) + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", SPF_strerror(SPF_response_errcode(spf_response))); return TRUE; } @@ -261,6 +309,22 @@ return TRUE; } +void +spf_response_debug(SPF_response_t * spf_response) +{ +if (SPF_response_messages(spf_response) == 0) + debug_printf(" (no errors)\n"); +else for (int i = 0; i < SPF_response_messages(spf_response); i++) + { + SPF_error_t * err = SPF_response_message(spf_response, i); + debug_printf( "%s_msg = (%d) %s\n", + (SPF_error_errorp(err) ? "warn" : "err"), + SPF_error_code(err), + SPF_error_message(err)); + } +} + + /* spf_process adds the envelope sender address to the existing context (if any), retrieves the result, sets up expansion strings and evaluates the condition outcome. @@ -303,6 +367,8 @@ else spf_smtp_comment = US SPF_response_get_smtp_comment(spf_response); rc = SPF_response_result(spf_response); + + DEBUG(D_acl) spf_response_debug(spf_response); } /* We got a result. Now see if we should return OK or FAIL for it */ @@ -339,8 +405,12 @@ if (spf_result_guessed) g = string_cat(g, US" (best guess record for domain)"); s = expand_string(US"$sender_address_domain"); +if (s && *s) + return string_append(g, 2, US" smtp.mailfrom=", s); + +s = sender_helo_name; return s && *s - ? string_append(g, 2, US" smtp.mailfrom=", s) + ? string_append(g, 2, US" smtp.helo=", s) : string_cat(g, US" smtp.mailfrom=<>"); }