SPF multiple strings join on "".

[exim.git] / src / src / lookups / dnsdb.c

diff --git a/src/src/lookups/dnsdb.c b/src/src/lookups/dnsdb.c
index cdac6a47ca93dd0f833228388e9468cfee9d3fef..be090cf7811cf68b4cbe6fd72be67d3e2b0850f4 100644 (file)
--- a/src/src/lookups/dnsdb.c
+++ b/src/src/lookups/dnsdb.c
@@ -1,15 +1,12 @@
-/* $Cambridge: exim/src/src/lookups/dnsdb.c,v 1.10 2005/02/17 11:58:27 ph10 Exp $ */
-

 /*************************************************
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 

-/* Copyright (c) University of Cambridge 1995 - 2005 */
+/* Copyright (c) University of Cambridge 1995 - 2012 */

 /* See the file NOTICE for conditions of use and distribution. */
 
 #include "../exim.h"
 #include "lf_functions.h"
 /* See the file NOTICE for conditions of use and distribution. */
 
 #include "../exim.h"
 #include "lf_functions.h"

-#include "dnsdb.h"

 
 
 
 
 
 


@@ -20,9 +17,14 @@ header files. */
 #define T_TXT 16
 #endif
 
 #define T_TXT 16
 #endif
 

+/* Many systems do not have T_SPF. */
+#ifndef T_SPF
+#define T_SPF 99
+#endif
+

 /* Table of recognized DNS record types and their integer values. */
 
 /* Table of recognized DNS record types and their integer values. */
 

-static char *type_names[] = {
+static const char *type_names[] = {

   "a",
 #if HAVE_IPV6
   "aaaa",
   "a",
 #if HAVE_IPV6
   "aaaa",


@@ -31,10 +33,12 @@ static char *type_names[] = {
   #endif
 #endif
   "cname",
   #endif
 #endif
   "cname",

+  "csa",

   "mx",
   "mxh",
   "ns",
   "ptr",
   "mx",
   "mxh",
   "ns",
   "ptr",

+  "spf",

   "srv",
   "txt",
   "zns"
   "srv",
   "txt",
   "zns"


@@ -49,10 +53,12 @@ static int type_values[] = {
   #endif
 #endif
   T_CNAME,
   #endif
 #endif
   T_CNAME,

+  T_CSA,     /* Private type for "Client SMTP Authorization". */

   T_MX,
   T_MXH,     /* Private type for "MX hostnames" */
   T_NS,
   T_PTR,
   T_MX,
   T_MXH,     /* Private type for "MX hostnames" */
   T_NS,
   T_PTR,

+  T_SPF,

   T_SRV,
   T_TXT,
   T_ZNS      /* Private type for "zone nameservers" */
   T_SRV,
   T_TXT,
   T_ZNS      /* Private type for "zone nameservers" */


@@ -65,7 +71,7 @@ static int type_values[] = {
 
 /* See local README for interface description. */
 
 
 /* See local README for interface description. */
 

-void *
+static void *

 dnsdb_open(uschar *filename, uschar **errmsg)
 {
 filename = filename;   /* Keep picky compilers happy */
 dnsdb_open(uschar *filename, uschar **errmsg)
 {
 filename = filename;   /* Keep picky compilers happy */


@@ -86,21 +92,28 @@ consist of a number of parts.
 separator character that is used when multiple records are found. The default
 separator is newline.
 
 separator character that is used when multiple records are found. The default
 separator is newline.
 

-(b) If the next sequence of characters is 'defer_FOO' followed by a comma,
+(b) If the next character is ',' then the next character is the separator
+character used for multiple items of text in "TXT" records. Alternatively,
+if the next character is ';' then these multiple items are concatenated with
+no separator. With neither of these options specified, only the first item
+is output.  Similarly for "SPF" records, but the default for joining multiple
+items in one SPF record is the empty string, for direct concatenation.
+
+(c) If the next sequence of characters is 'defer_FOO' followed by a comma,

 the defer behaviour is set to FOO. The possible behaviours are: 'strict', where
 any defer causes the whole lookup to defer; 'lax', where a defer causes the
 whole lookup to defer only if none of the DNS queries succeeds; and 'never',
 where all defers are as if the lookup failed. The default is 'lax'.
 
 the defer behaviour is set to FOO. The possible behaviours are: 'strict', where
 any defer causes the whole lookup to defer; 'lax', where a defer causes the
 whole lookup to defer only if none of the DNS queries succeeds; and 'never',
 where all defers are as if the lookup failed. The default is 'lax'.
 

-(c) If the next sequence of characters is a sequence of letters and digits
+(d) If the next sequence of characters is a sequence of letters and digits

 followed by '=', it is interpreted as the name of the DNS record type. The
 default is "TXT".
 
 followed by '=', it is interpreted as the name of the DNS record type. The
 default is "TXT".
 

-(d) Then there follows list of domain names. This is a generalized Exim list,
+(e) Then there follows list of domain names. This is a generalized Exim list,

 which may start with '<' in order to set a specific separator. The default
 separator, as always, is colon. */
 
 which may start with '<' in order to set a specific separator. The default
 separator, as always, is colon. */
 

-int
+static int

 dnsdb_find(void *handle, uschar *filename, uschar *keystring, int length,
   uschar **result, uschar **errmsg, BOOL *do_cache)
 {
 dnsdb_find(void *handle, uschar *filename, uschar *keystring, int length,
   uschar **result, uschar **errmsg, BOOL *do_cache)
 {


@@ -112,7 +125,8 @@ int defer_mode = PASS;
 int type = T_TXT;
 int failrc = FAIL;
 uschar *outsep = US"\n";
 int type = T_TXT;
 int failrc = FAIL;
 uschar *outsep = US"\n";

-uschar *equals, *domain;
+uschar *outsep2 = NULL;
+uschar *equals, *domain, *found;

 uschar buffer[256];
 
 /* Because we're the working in the search pool, we try to reclaim as much
 uschar buffer[256];
 
 /* Because we're the working in the search pool, we try to reclaim as much


@@ -129,16 +143,35 @@ filename = filename;
 length = length;
 do_cache = do_cache;
 
 length = length;
 do_cache = do_cache;
 

-/* If the string starts with '>' we change the output separator */
+/* If the string starts with '>' we change the output separator.
+If it's followed by ';' or ',' we set the TXT output separator. */

 
 while (isspace(*keystring)) keystring++;
 if (*keystring == '>')
   {
   outsep = keystring + 1;
   keystring += 2;
 
 while (isspace(*keystring)) keystring++;
 if (*keystring == '>')
   {
   outsep = keystring + 1;
   keystring += 2;

+  if (*keystring == ',')
+    {
+    outsep2 = keystring + 1;
+    keystring += 2;
+    }
+  else if (*keystring == ';')
+    {
+    outsep2 = US"";
+    keystring++;
+    }

   while (isspace(*keystring)) keystring++;
   }
 
   while (isspace(*keystring)) keystring++;
   }
 

+/* SPF strings should be concatenated without a separator, thus make
+it the default if not defined (see RFC 4408 section 3.1.3).
+Multiple SPF records are forbidden (section 3.1.2) but are currently
+not handled specially, thus they are concatenated with \n by default. */
+
+if (type == T_SPF && outsep2 == NULL)
+  outsep2 = US"";
+

 /* Check for a defer behaviour keyword. */
 
 if (strncmpic(keystring, US"defer_", 6) == 0)
 /* Check for a defer behaviour keyword. */
 
 if (strncmpic(keystring, US"defer_", 6) == 0)


@@ -219,7 +252,7 @@ remaining string is valid as an IP address, set an impossible separator so that
 it is treated as one item. */
 
 if (type == T_PTR && keystring[0] != '<' &&
 it is treated as one item. */
 
 if (type == T_PTR && keystring[0] != '<' &&

-    string_is_ip_address(keystring, NULL) > 0)
+    string_is_ip_address(keystring, NULL) != 0)

   sep = -1;
 
 /* Now scan the list and do a lookup for each item */
   sep = -1;
 
 /* Now scan the list and do a lookup for each item */


@@ -228,15 +261,18 @@ while ((domain = string_nextinlist(&keystring, &sep, buffer, sizeof(buffer)))
         != NULL)
   {
   uschar rbuffer[256];
         != NULL)
   {
   uschar rbuffer[256];

-  int searchtype = (type == T_ZNS)? T_NS :          /* record type we want */
-                   (type == T_MXH)? T_MX : type;
-
-  /* If the type is PTR, we have to construct the relevant magic lookup key if
-  the original is an IP address (some experimental protocols are using PTR
-  records for different purposes where the key string is a host name). This
-  code for doing the reversal is now in a separate function. */
-
-  if (type == T_PTR && string_is_ip_address(domain, NULL) > 0)
+  int searchtype = (type == T_CSA)? T_SRV :         /* record type we want */
+                   (type == T_MXH)? T_MX :
+                   (type == T_ZNS)? T_NS : type;
+
+  /* If the type is PTR or CSA, we have to construct the relevant magic lookup
+  key if the original is an IP address (some experimental protocols are using
+  PTR records for different purposes where the key string is a host name, and
+  Exim's extended CSA can be keyed by domains or IP addresses). This code for
+  doing the reversal is now in a separate function. */
+
+  if ((type == T_PTR || type == T_CSA) &&
+      string_is_ip_address(domain, NULL) != 0)

     {
     dns_build_reverse(domain, rbuffer);
     domain = rbuffer;
     {
     dns_build_reverse(domain, rbuffer);
     domain = rbuffer;


@@ -244,15 +280,16 @@ while ((domain = string_nextinlist(&keystring, &sep, buffer, sizeof(buffer)))
 
   DEBUG(D_lookup) debug_printf("dnsdb key: %s\n", domain);
 
 
   DEBUG(D_lookup) debug_printf("dnsdb key: %s\n", domain);
 

-  /* Do the lookup and sort out the result. There are two special types that
-  are handled specially: T_ZNS and T_MXH. The former is handled in a special
-  lookup function so that the facility could be used from other parts of the
-  Exim code. The latter affects only what happens later on in this function,
-  but for tidiness it is handled in a similar way. If the lookup fails,
-  continue with the next domain. In the case of DEFER, adjust the final
-  "nothing found" result, but carry on to the next domain. */
+  /* Do the lookup and sort out the result. There are three special types that
+  are handled specially: T_CSA, T_ZNS and T_MXH. The former two are handled in
+  a special lookup function so that the facility could be used from other
+  parts of the Exim code. The latter affects only what happens later on in
+  this function, but for tidiness it is handled in a similar way. If the
+  lookup fails, continue with the next domain. In the case of DEFER, adjust
+  the final "nothing found" result, but carry on to the next domain. */

 
 

-  rc = dns_special_lookup(&dnsa, domain, type, NULL);
+  found = domain;
+  rc = dns_special_lookup(&dnsa, domain, type, &found);

 
   if (rc == DNS_NOMATCH || rc == DNS_NODATA) continue;
   if (rc != DNS_SUCCEED)
 
   if (rc == DNS_NOMATCH || rc == DNS_NODATA) continue;
   if (rc != DNS_SUCCEED)


@@ -295,37 +332,86 @@ while ((domain = string_nextinlist(&keystring, &sep, buffer, sizeof(buffer)))
 
     if (ptr != 0) yield = string_cat(yield, &size, &ptr, outsep, 1);
 
 
     if (ptr != 0) yield = string_cat(yield, &size, &ptr, outsep, 1);
 

-    if (type == T_TXT)
+    if (type == T_TXT || type == T_SPF)

       {
       {

-      yield = string_cat(yield, &size, &ptr, (uschar *)(rr->data+1),
-        (rr->data)[0]);
+      if (outsep2 == NULL)
+        {
+        /* output only the first item of data */
+        yield = string_cat(yield, &size, &ptr, (uschar *)(rr->data+1),
+          (rr->data)[0]);
+        }
+      else
+        {
+        /* output all items */
+        int data_offset = 0;
+        while (data_offset < rr->size)
+          {
+          uschar chunk_len = (rr->data)[data_offset++];
+          if (outsep2[0] != '\0' && data_offset != 1)
+            yield = string_cat(yield, &size, &ptr, outsep2, 1);
+          yield = string_cat(yield, &size, &ptr,
+                             (uschar *)((rr->data)+data_offset), chunk_len);
+          data_offset += chunk_len;
+          }
+        }

       }
       }

-    else   /* T_CNAME, T_MX, T_MXH, T_NS, T_SRV, T_PTR */
+    else   /* T_CNAME, T_CSA, T_MX, T_MXH, T_NS, T_PTR, T_SRV */

       {
       {

-      int num;
+      int priority, weight, port;

       uschar s[264];
       uschar *p = (uschar *)(rr->data);
 
       if (type == T_MXH)
         {
         /* mxh ignores the priority number and includes only the hostnames */
       uschar s[264];
       uschar *p = (uschar *)(rr->data);
 
       if (type == T_MXH)
         {
         /* mxh ignores the priority number and includes only the hostnames */

-        GETSHORT(num, p);            /* pointer is advanced */
+        GETSHORT(priority, p);

         }
       else if (type == T_MX)
         {
         }
       else if (type == T_MX)
         {

-        GETSHORT(num, p);            /* pointer is advanced */
-        sprintf(CS s, "%d ", num);
+        GETSHORT(priority, p);
+        sprintf(CS s, "%d ", priority);

         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
         }
       else if (type == T_SRV)
         {
         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
         }
       else if (type == T_SRV)
         {

-        int weight, port;
-        GETSHORT(num, p);            /* pointer is advanced */
+        GETSHORT(priority, p);

         GETSHORT(weight, p);
         GETSHORT(port, p);
         GETSHORT(weight, p);
         GETSHORT(port, p);

-        sprintf(CS s, "%d %d %d ", num, weight, port);
+        sprintf(CS s, "%d %d %d ", priority, weight, port);

         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
         }
         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
         }

+      else if (type == T_CSA)
+        {
+        /* See acl_verify_csa() for more comments about CSA. */
+
+        GETSHORT(priority, p);
+        GETSHORT(weight, p);
+        GETSHORT(port, p);
+
+        if (priority != 1) continue;      /* CSA version must be 1 */
+
+        /* If the CSA record we found is not the one we asked for, analyse
+        the subdomain assertions in the port field, else analyse the direct
+        authorization status in the weight field. */
+
+        if (found != domain)
+          {
+          if (port & 1) *s = 'X';         /* explicit authorization required */
+          else *s = '?';                  /* no subdomain assertions here */
+          }
+        else
+          {
+          if (weight < 2) *s = 'N';       /* not authorized */
+          else if (weight == 2) *s = 'Y'; /* authorized */
+          else if (weight == 3) *s = '?'; /* unauthorizable */
+          else continue;                  /* invalid */
+          }
+
+        s[1] = ' ';
+        yield = string_cat(yield, &size, &ptr, s, 2);
+        }
+
+      /* GETSHORT() has advanced the pointer to the target domain. */

 
       rc = dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
         (DN_EXPAND_ARG4_TYPE)(s), sizeof(s));
 
       rc = dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
         (DN_EXPAND_ARG4_TYPE)(s), sizeof(s));


@@ -357,4 +443,42 @@ yield[ptr] = 0;
 return OK;
 }
 
 return OK;
 }
 

+
+
+/*************************************************
+*         Version reporting entry point          *
+*************************************************/
+
+/* See local README for interface description. */
+
+#include "../version.h"
+
+void
+dnsdb_version_report(FILE *f)
+{
+#ifdef DYNLOOKUP
+fprintf(f, "Library version: DNSDB: Exim version %s\n", EXIM_VERSION_STR);
+#endif
+}
+
+
+static lookup_info _lookup_info = {
+  US"dnsdb",                     /* lookup name */
+  lookup_querystyle,             /* query style */
+  dnsdb_open,                    /* open function */
+  NULL,                          /* check function */
+  dnsdb_find,                    /* find function */
+  NULL,                          /* no close function */
+  NULL,                          /* no tidy function */
+  NULL,                          /* no quoting function */
+  dnsdb_version_report           /* version reporting */
+};
+
+#ifdef DYNLOOKUP
+#define dnsdb_lookup_module_info _lookup_module_info
+#endif
+
+static lookup_info *_lookup_list[] = { &_lookup_info };
+lookup_module_info dnsdb_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
+

 /* End of lookups/dnsdb.c */
 /* End of lookups/dnsdb.c */