New init flags and options to influence address family selection.

diff --git a/src/adns.h b/src/adns.h
index 267fd6e66addb293d092ad3f3b0236ae0bdb0d70..e5063b76b8ca0e921dd5cc571e477c472d256b26 100644 (file)
--- a/src/adns.h
+++ b/src/adns.h
@@ -104,7 +104,18 @@ typedef enum { /* In general, or together the desired flags: */
  adns_if_eintr=       0x0020,/* allow _wait and _synchronous to return EINTR */
  adns_if_nosigpipe=   0x0040,/* applic has SIGPIPE ignored, do not protect */
  adns_if_checkc_entex=0x0100,/* consistency checks on entry/exit to adns fns */
- adns_if_checkc_freq= 0x0300 /* consistency checks very frequently (slow!) */
+ adns_if_checkc_freq= 0x0300,/* consistency checks very frequently (slow!) */
+
+ adns_if_af_v4only=   0x0400,/* only return IPv4 addresses, given the choice */
+ adns_if_af_v6only=   0x0800,/* only return IPv6 addresses, ... */
+ adns_if_afmask=      adns_if_af_v4only|adns_if_af_v6only
+   /* Only set one of these.  They are policy flags, and overridden by the
+    * adns_af:... options in resolv.conf.  If the adns_qf_ipv... query
+    * flags are incompatible with these settings (in the sense that no
+    * address families are permitted at all) then the query flags take
+    * precedence; otherwise only records which satisfy all of the stated
+    * requirements are allowed.
+    */
 } adns_initflags;
 
 typedef enum { /* In general, or together the desired flags: */
@@ -555,6 +566,17 @@ int adns_init_logfn(adns_state *newstate_r, adns_initflags flags,
  *   Changes the consistency checking frequency; this overrides the
  *   setting of adns_if_check_entex, adns_if_check_freq, or neither,
  *   in the flags passed to adns_init.
+ *
+ *  adns_af:v4only
+ *  adns_af:v6only
+ *  adns_af:any
+ *   Controls whether ADNS looks for IPv4 (A records) and IPv6 (AAAA
+ *   records) addresses when it's trying to build a socket address.
+ *   The default is `any' which means to allow both.  The `sortlist'
+ *   directive can be used to control the relative preference of IPv4
+ *   and IPv6 addresses if both are returned for the same query.
+ *   These override the corresponding init flags (covered by
+ *   adns_if_afmask).
  * 
  * There are a number of environment variables which can modify the
  * behaviour of adns.  They take effect only if adns_init is used, and

diff --git a/src/setup.c b/src/setup.c
index 67dcd1abf4f0e7fbdc988388d7d72fd488374ddf..a264d15ea83aa61260a1c6300b0b0beebcfc9825 100644 (file)
--- a/src/setup.c
+++ b/src/setup.c
@@ -310,6 +310,19 @@ static void ccf_options(adns_state ads, const char *fn,
       }
       continue;
     }
+    if (l>=8 && !memcmp(word,"adns_af:",8)) {
+      if (!strcmp(word+8,"v4only"))
+       ads->iflags = (ads->iflags & ~adns_if_afmask) | adns_if_af_v4only;
+      else if (!strcmp(word+8,"v6only"))
+       ads->iflags = (ads->iflags & ~adns_if_afmask) | adns_if_af_v6only;
+      else if (!strcmp(word+8,"any"))
+       ads->iflags = (ads->iflags & ~adns_if_afmask);
+      else {
+       configparseerr(ads,fn,lno, "option adns_af has bad value `%s' "
+                      "(must be any, v4only or v6only", word+8);
+      }
+      continue;
+    }
     adns__diag(ads,-1,0,"%s:%d: unknown option `%.*s'", fn,lno, l,word);
   }
 }

diff --git a/src/types.c b/src/types.c
index 582ddb58bdab3da6ff77830ba5348da6c84a0047..11f9fd4d7f10fb1033dbcee1eddb78fc5bf627a5 100644 (file)
--- a/src/types.c
+++ b/src/types.c
@@ -485,9 +485,21 @@ static void addr_rrtypes(adns_state ads, adns_rrtype type,
 {
   size_t n = 0;
   adns_rrtype qtf = type & adns__qtf_deref;
+  adns_queryflags permitaf = 0, hackaf = 0;
 
   if (!(type & adns__qtf_bigaddr) || !(type & adns__qtf_manyaf))
     qf = (qf & adns__qf_afmask) | adns_qf_ipv4_only;
+  else if (ads->iflags & adns_if_afmask) {
+    if (ads->iflags & adns_if_af_v4only) {
+      permitaf |= adns_qf_ipv4_only;
+      hackaf |= adns_qf_domapv4;
+    }
+    if (ads->iflags & adns_if_af_v6only)
+      permitaf |= adns_qf_ipv6_only;
+    if (qf & permitaf)
+      qf &= hackaf | permitaf | ~adns__qf_afmask;
+  }
+
 
   if (qf & adns_qf_ipv4_only) rrty[n++] = adns_r_a | qtf;
   if (qf & adns_qf_ipv6_only) rrty[n++] = adns_r_aaaa | qtf;