SPF: fix handling mix of spf and other txt records. Bug 2499
[exim.git] / src / src / spf.c
index b7041d3..8ead817 100644 (file)
@@ -37,90 +37,111 @@ SPF_dns_rr_t  * spf_nxdomain = NULL;
 
 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;
 SPF_dns_rr_t * spfrr;
+unsigned found = 0;
+
+SPF_dns_rr_t srr = {
+  .domain = CS domain,                 /* query information */
+  .domain_buf_len = 0,
+  .rr_type = rr_type,
+
+  .rr_buf_len = 0,                     /* answer information */
+  .rr_buf_num = 0, /* no free of s */
+  .utc_ttl = 0,
+
+  .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_SUCCEED)
-  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
-       && (rr_type != T_TXT || Ustrncmp(rr->data+1, "v=spf1", 6) == 0))
+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++;
+
+if (found == 0)
+  {
+  SPF_dns_rr_dup(&spfrr, &srr);
+  return spfrr;
+  }
+
+srr.rr = store_malloc(sizeof(SPF_dns_rr_data_t) * found);
+
+found = 0;
+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)
+    {
+    const uschar * s = rr->data;
+
+    srr.ttl = rr->ttl;
+    switch(rr_type)
       {
-      const uschar * s = rr->data;
-      SPF_dns_rr_t srr = {
-       .domain = CS rr->name,                  /* query information */
-       .domain_buf_len = DNS_MAXNAME,
-       .rr_type = rr->type,
-
-       .num_rr = 1,                            /* answer information */
-       .rr = NULL,
-       .rr_buf_len = 0,
-       .rr_buf_num = 0,
-       .ttl = rr->ttl,
-       .utc_ttl = 0,
-       .herrno = NETDB_SUCCESS,
-
-       .hook = NULL,                           /* misc information */
-       .source = spf_dns_server
-      };
-
-      switch(rr_type)
+      case T_MX:
+       s += 2; /* skip the MX precedence field */
+      case T_PTR:
        {
-        case T_MX:
-          s += 2;                      /* skip the MX precedence field */
-        case T_PTR:
-         {
-          uschar * buf = store_malloc(256);
-          (void)dn_expand(dnsa->answer, dnsa->answer + dnsa->answerlen, s,
-            (DN_EXPAND_ARG4_TYPE)buf, 256);
-          s = buf;
-          break;
-         }
+       uschar * buf = store_malloc(256);
+       (void)dn_expand(dnsa->answer, dnsa->answer + dnsa->answerlen, s,
+         (DN_EXPAND_ARG4_TYPE)buf, 256);
+       s = buf;
+       break;
+       }
 
-        case T_TXT:
+      case T_TXT:
+       {
+       gstring * g = NULL;
+       uschar chunk_len;
+
+       if (strncmpic(rr->data+1, US"v=spf1", 6) != 0)
          {
-         gstring * g = NULL;
-         uschar chunk_len;
-          for (int off = 0; off < rr->size; off += chunk_len)
-            {
-            if (!(chunk_len = s[off++])) break;
-            g = string_catn(g, s+off, chunk_len);
-            }
-          if (!g)
-            {
-            HDEBUG(D_host_lookup) debug_printf("IP address lookup yielded an "
-              "empty name: treated as non-existent host name\n");
-            continue;
-            }
-          gstring_release_unused(g);
-          s = string_copy_malloc(string_from_gstring(g));
-          break;
+         HDEBUG(D_host_lookup) debug_printf("not an spf record\n");
+         continue;
          }
 
-        case T_A:
-        case T_AAAA:
-        default:
+       for (int off = 0; off < rr->size; off += chunk_len)
          {
-          uschar * buf = store_malloc(dnsa->answerlen + 1);
-         s = memcpy(buf, s, dnsa->answerlen + 1);
-          break;
+         if (!(chunk_len = s[off++])) break;
+         g = string_catn(g, s+off, chunk_len);
          }
+       if (!g)
+         continue;
+       gstring_release_unused(g);
+       s = string_copy_malloc(string_from_gstring(g));
+       break;
        }
-      DEBUG(D_receive) debug_printf("SPF_dns_exim_lookup '%s'\n", s);
-      srr.rr = (void *) &s;
-
-      /* spfrr->rr must have been malloc()d for this */
-      SPF_dns_rr_dup(&spfrr, &srr);
 
-      return spfrr;
+      case T_A:
+      case T_AAAA:
+      default:
+       {
+       uschar * buf = store_malloc(dnsa->answerlen + 1);
+       s = memcpy(buf, s, dnsa->answerlen + 1);
+       break;
+       }
       }
+    DEBUG(D_receive) debug_printf("SPF_dns_exim_lookup '%s'\n", s);
+    srr.rr[found++] = (void *) s;
+    }
 
-SPF_dns_rr_dup(&spfrr, spf_nxdomain);
+srr.num_rr = found;
+/* spfrr->rr must have been malloc()d for this */
+SPF_dns_rr_dup(&spfrr, &srr);
 return spfrr;
 }
 
@@ -129,14 +150,11 @@ return spfrr;
 SPF_dns_server_t *
 SPF_dns_exim_new(int debug)
 {
-SPF_dns_server_t *spf_dns_server;
+SPF_dns_server_t * spf_dns_server = store_malloc(sizeof(SPF_dns_server_t));
 
 DEBUG(D_receive) debug_printf("SPF_dns_exim_new\n");
 
-if (!(spf_dns_server = malloc(sizeof(SPF_dns_server_t))))
-  return NULL;
 memset(spf_dns_server, 0, sizeof(SPF_dns_server_t));
-
 spf_dns_server->destroy      = NULL;
 spf_dns_server->lookup       = SPF_dns_exim_lookup;
 spf_dns_server->get_spf      = NULL;